Merge tag 'for-5.15-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs updates from David Sterba:
 "The highlights of this round are integrations with fs-verity and
  idmapped mounts, the rest is usual mix of minor improvements, speedups
  and cleanups.

  There are some patches outside of btrfs, namely updating some VFS
  interfaces, all straightforward and acked.

  Features:

   - fs-verity support, using standard ioctls, backward compatible with
     read-only limitation on inodes with previously enabled fs-verity

   - idmapped mount support

   - make mount with rescue=ibadroots more tolerant to partially damaged
     trees

   - allow raid0 on a single device and raid10 on two devices,
     degenerate cases but might be useful as an intermediate step during
     conversion to other profiles

   - zoned mode block group auto reclaim can be disabled via sysfs knob

  Performance improvements:

   - continue readahead of node siblings even if target node is in
     memory, could speed up full send (on sample test +11%)

   - batching of delayed items can speed up creating many files

   - fsync/tree-log speedups
       - avoid unnecessary work (gains +2% throughput, -2% run time on
         sample load)
       - reduced lock contention on renames (on dbench +4% throughput,
         up to -30% latency)

  Fixes:

   - various zoned mode fixes

   - preemptive flushing threshold tuning, avoid excessive work on
     almost full filesystems

  Core:

   - continued subpage support, preparation for implementing remaining
     features like compression and defragmentation; with some
     limitations, write is now enabled on 64K page systems with 4K
     sectors, still considered experimental
       - no readahead on compressed reads
       - inline extents disabled
       - disabled raid56 profile conversion and mount

   - improved flushing logic, fixing early ENOSPC on some workloads

   - inode flags have been internally split to read-only and read-write
     incompat bit parts, used by fs-verity

   - new tree items for fs-verity
       - descriptor item
       - Merkle tree item

   - inode operations extended to be namespace-aware

   - cleanups and refactoring

  Generic code changes:

   - fs: new export filemap_fdatawrite_wbc

   - fs: removed sync_inode

   - block: bio_trim argument type fixups

   - vfs: add namespace-aware lookup"

* tag 'for-5.15-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (114 commits)
  btrfs: reset replace target device to allocation state on close
  btrfs: zoned: fix ordered extent boundary calculation
  btrfs: do not do preemptive flushing if the majority is global rsv
  btrfs: reduce the preemptive flushing threshold to 90%
  btrfs: tree-log: check btrfs_lookup_data_extent return value
  btrfs: avoid unnecessarily logging directories that had no changes
  btrfs: allow idmapped mount
  btrfs: handle ACLs on idmapped mounts
  btrfs: allow idmapped INO_LOOKUP_USER ioctl
  btrfs: allow idmapped SUBVOL_SETFLAGS ioctl
  btrfs: allow idmapped SET_RECEIVED_SUBVOL ioctls
  btrfs: relax restrictions for SNAP_DESTROY_V2 with subvolids
  btrfs: allow idmapped SNAP_DESTROY ioctls
  btrfs: allow idmapped SNAP_CREATE/SUBVOL_CREATE ioctls
  btrfs: check whether fsgid/fsuid are mapped during subvolume creation
  btrfs: allow idmapped permission inode op
  btrfs: allow idmapped setattr inode op
  btrfs: allow idmapped tmpfile inode op
  btrfs: allow idmapped symlink inode op
  btrfs: allow idmapped mkdir inode op
  ...

58 files changed, 2769 insertions, 1425 deletions

diff --git a/block/bio.c b/block/bio.c
index 1319dd2aa0b8..e16849f46b0e 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -1544,12 +1544,15 @@ EXPORT_SYMBOL(bio_split);
  * @bio:	bio to trim
  * @offset:	number of sectors to trim from the front of @bio
  * @size:	size we want to trim @bio to, in sectors
+ *
+ * This function is typically used for bios that are cloned and submitted
+ * to the underlying device in parts.
  */
-void bio_trim(struct bio *bio, int offset, int size)
+void bio_trim(struct bio *bio, sector_t offset, sector_t size)
 {
-	/* 'bio' is a cloned bio which we need to trim to match
-	 * the given offset and size.
-	 */
+	if (WARN_ON_ONCE(offset > BIO_MAX_SECTORS || size > BIO_MAX_SECTORS ||
+			 offset + size > bio->bi_iter.bi_size))
+		return;
 
 	size <<= 9;
 	if (offset == 0 && size == bio->bi_iter.bi_size)
@@ -1560,7 +1563,6 @@ void bio_trim(struct bio *bio, int offset, int size)
 
 	if (bio_integrity(bio))
 		bio_integrity_trim(bio);
-
 }
 EXPORT_SYMBOL_GPL(bio_trim);
 
diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c
index c4a2dc41beac..aab5e6538660 100644
--- a/fs/9p/vfs_file.c
+++ b/fs/9p/vfs_file.c
@@ -612,12 +612,7 @@ static void v9fs_mmap_vm_close(struct vm_area_struct *vma)
 	p9_debug(P9_DEBUG_VFS, "9p VMA close, %p, flushing", vma);
 
 	inode = file_inode(vma->vm_file);
-
-	if (!mapping_can_writeback(inode->i_mapping))
-		wbc.nr_to_write = 0;
-
-	might_sleep();
-	sync_inode(inode, &wbc);
+	filemap_fdatawrite_wbc(inode->i_mapping, &wbc);
 }
 
 
diff --git a/fs/btrfs/Makefile b/fs/btrfs/Makefile
index cec88a66bd6c..3dcf9bcc2326 100644
--- a/fs/btrfs/Makefile
+++ b/fs/btrfs/Makefile
@@ -36,6 +36,7 @@ btrfs-$(CONFIG_BTRFS_FS_POSIX_ACL) += acl.o
 btrfs-$(CONFIG_BTRFS_FS_CHECK_INTEGRITY) += check-integrity.o
 btrfs-$(CONFIG_BTRFS_FS_REF_VERIFY) += ref-verify.o
 btrfs-$(CONFIG_BLK_DEV_ZONED) += zoned.o
+btrfs-$(CONFIG_FS_VERITY) += verity.o
 
 btrfs-$(CONFIG_BTRFS_FS_RUN_SANITY_TESTS) += tests/free-space-tests.o \
 	tests/extent-buffer-tests.o tests/btrfs-tests.o \
diff --git a/fs/btrfs/acl.c b/fs/btrfs/acl.c
index d95eb5c8cb37..c9f9789e828f 100644
--- a/fs/btrfs/acl.c
+++ b/fs/btrfs/acl.c
@@ -53,7 +53,8 @@ struct posix_acl *btrfs_get_acl(struct inode *inode, int type)
 }
 
 static int __btrfs_set_acl(struct btrfs_trans_handle *trans,
-			 struct inode *inode, struct posix_acl *acl, int type)
+			   struct user_namespace *mnt_userns,
+			   struct inode *inode, struct posix_acl *acl, int type)
 {
 	int ret, size = 0;
 	const char *name;
@@ -114,12 +115,12 @@ int btrfs_set_acl(struct user_namespace *mnt_userns, struct inode *inode,
 	umode_t old_mode = inode->i_mode;
 
 	if (type == ACL_TYPE_ACCESS && acl) {
-		ret = posix_acl_update_mode(&init_user_ns, inode,
+		ret = posix_acl_update_mode(mnt_userns, inode,
 					    &inode->i_mode, &acl);
 		if (ret)
 			return ret;
 	}
-	ret = __btrfs_set_acl(NULL, inode, acl, type);
+	ret = __btrfs_set_acl(NULL, mnt_userns, inode, acl, type);
 	if (ret)
 		inode->i_mode = old_mode;
 	return ret;
@@ -140,14 +141,14 @@ int btrfs_init_acl(struct btrfs_trans_handle *trans,
 		return ret;
 
 	if (default_acl) {
-		ret = __btrfs_set_acl(trans, inode, default_acl,
+		ret = __btrfs_set_acl(trans, &init_user_ns, inode, default_acl,
 				      ACL_TYPE_DEFAULT);
 		posix_acl_release(default_acl);
 	}
 
 	if (acl) {
 		if (!ret)
-			ret = __btrfs_set_acl(trans, inode, acl,
+			ret = __btrfs_set_acl(trans, &init_user_ns, inode, acl,
 					      ACL_TYPE_ACCESS);
 		posix_acl_release(acl);
 	}
diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
index 78b202d198b8..f735b8798ba1 100644
--- a/fs/btrfs/backref.c
+++ b/fs/btrfs/backref.c
@@ -1211,7 +1211,7 @@ static int find_parent_nodes(struct btrfs_trans_handle *trans,
 again:
 	head = NULL;
 
-	ret = btrfs_search_slot(trans, fs_info->extent_root, &key, path, 0, 0);
+	ret = btrfs_search_slot(NULL, fs_info->extent_root, &key, path, 0, 0);
 	if (ret < 0)
 		goto out;
 	BUG_ON(ret == 0);
@@ -1488,14 +1488,14 @@ static int btrfs_find_all_roots_safe(struct btrfs_trans_handle *trans,
 int btrfs_find_all_roots(struct btrfs_trans_handle *trans,
 			 struct btrfs_fs_info *fs_info, u64 bytenr,
 			 u64 time_seq, struct ulist **roots,
-			 bool ignore_offset, bool skip_commit_root_sem)
+			 bool skip_commit_root_sem)
 {
 	int ret;
 
 	if (!trans && !skip_commit_root_sem)
 		down_read(&fs_info->commit_root_sem);
 	ret = btrfs_find_all_roots_safe(trans, fs_info, bytenr,
-					time_seq, roots, ignore_offset);
+					time_seq, roots, false);
 	if (!trans && !skip_commit_root_sem)
 		up_read(&fs_info->commit_root_sem);
 	return ret;
diff --git a/fs/btrfs/backref.h b/fs/btrfs/backref.h
index ff5f07f9940b..ba454032dbe2 100644
--- a/fs/btrfs/backref.h
+++ b/fs/btrfs/backref.h
@@ -47,7 +47,7 @@ int btrfs_find_all_leafs(struct btrfs_trans_handle *trans,
 			 const u64 *extent_item_pos, bool ignore_offset);
 int btrfs_find_all_roots(struct btrfs_trans_handle *trans,
 			 struct btrfs_fs_info *fs_info, u64 bytenr,
-			 u64 time_seq, struct ulist **roots, bool ignore_offset,
+			 u64 time_seq, struct ulist **roots,
 			 bool skip_commit_root_sem);
 char *btrfs_ref_to_path(struct btrfs_root *fs_root, struct btrfs_path *path,
 			u32 name_len, unsigned long name_off,
diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
index 9e7d9d0c763d..a3b830b8410a 100644
--- a/fs/btrfs/block-group.c
+++ b/fs/btrfs/block-group.c
@@ -1561,7 +1561,7 @@ void btrfs_reclaim_bgs_work(struct work_struct *work)
 				div64_u64(zone_unusable * 100, bg->length));
 		trace_btrfs_reclaim_block_group(bg);
 		ret = btrfs_relocate_chunk(fs_info, bg->start);
-		if (ret)
+		if (ret && ret != -EAGAIN)
 			btrfs_err(fs_info, "error relocating chunk %llu",
 				  bg->start);
 
@@ -2105,11 +2105,22 @@ static int fill_dummy_bgs(struct btrfs_fs_info *fs_info)
 		bg->used = em->len;
 		bg->flags = map->type;
 		ret = btrfs_add_block_group_cache(fs_info, bg);
+		/*
+		 * We may have some valid block group cache added already, in
+		 * that case we skip to the next one.
+		 */
+		if (ret == -EEXIST) {
+			ret = 0;
+			btrfs_put_block_group(bg);
+			continue;
+		}
+
 		if (ret) {
 			btrfs_remove_free_space_cache(bg);
 			btrfs_put_block_group(bg);
 			break;
 		}
+
 		btrfs_update_space_info(fs_info, bg->flags, em->len, em->len,
 					0, 0, &space_info);
 		bg->space_info = space_info;
@@ -2212,6 +2223,14 @@ int btrfs_read_block_groups(struct btrfs_fs_info *info)
 	ret = check_chunk_block_group_mappings(info);
 error:
 	btrfs_free_path(path);
+	/*
+	 * We've hit some error while reading the extent tree, and have
+	 * rescue=ibadroots mount option.
+	 * Try to fill the tree using dummy block groups so that the user can
+	 * continue to mount and grab their data.
+	 */
+	if (ret && btrfs_test_opt(info, IGNOREBADROOTS))
+		ret = fill_dummy_bgs(info);
 	return ret;
 }
 
@@ -2244,6 +2263,95 @@ static int insert_block_group_item(struct btrfs_trans_handle *trans,
 	return btrfs_insert_item(trans, root, &key, &bgi, sizeof(bgi));
 }
 
+static int insert_dev_extent(struct btrfs_trans_handle *trans,
+			    struct btrfs_device *device, u64 chunk_offset,
+			    u64 start, u64 num_bytes)
+{
+	struct btrfs_fs_info *fs_info = device->fs_info;
+	struct btrfs_root *root = fs_info->dev_root;
+	struct btrfs_path *path;
+	struct btrfs_dev_extent *extent;
+	struct extent_buffer *leaf;
+	struct btrfs_key key;
+	int ret;
+
+	WARN_ON(!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state));
+	WARN_ON(test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state));
+	path = btrfs_alloc_path();
+	if (!path)
+		return -ENOMEM;
+
+	key.objectid = device->devid;
+	key.type = BTRFS_DEV_EXTENT_KEY;
+	key.offset = start;
+	ret = btrfs_insert_empty_item(trans, root, path, &key, sizeof(*extent));
+	if (ret)
+		goto out;
+
+	leaf = path->nodes[0];
+	extent = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_extent);
+	btrfs_set_dev_extent_chunk_tree(leaf, extent, BTRFS_CHUNK_TREE_OBJECTID);
+	btrfs_set_dev_extent_chunk_objectid(leaf, extent,
+					    BTRFS_FIRST_CHUNK_TREE_OBJECTID);
+	btrfs_set_dev_extent_chunk_offset(leaf, extent, chunk_offset);
+
+	btrfs_set_dev_extent_length(leaf, extent, num_bytes);
+	btrfs_mark_buffer_dirty(leaf);
+out:
+	btrfs_free_path(path);
+	return ret;
+}
+
+/*
+ * This function belongs to phase 2.
+ *
+ * See the comment at btrfs_chunk_alloc() for details about the chunk allocation
+ * phases.
+ */
+static int insert_dev_extents(struct btrfs_trans_handle *trans,
+				   u64 chunk_offset, u64 chunk_size)
+{
+	struct btrfs_fs_info *fs_info = trans->fs_info;
+	struct btrfs_device *device;
+	struct extent_map *em;
+	struct map_lookup *map;
+	u64 dev_offset;
+	u64 stripe_size;
+	int i;
+	int ret = 0;
+
+	em = btrfs_get_chunk_map(fs_info, chunk_offset, chunk_size);
+	if (IS_ERR(em))
+		return PTR_ERR(em);
+
+	map = em->map_lookup;
+	stripe_size = em->orig_block_len;
+
+	/*
+	 * Take the device list mutex to prevent races with the final phase of
+	 * a device replace operation that replaces the device object associated
+	 * with the map's stripes, because the device object's id can change
+	 * at any time during that final phase of the device replace operation
+	 * (dev-replace.c:btrfs_dev_replace_finishing()), so we could grab the
+	 * replaced device and then see it with an ID of BTRFS_DEV_REPLACE_DEVID,
+	 * resulting in persisting a device extent item with such ID.
+	 */
+	mutex_lock(&fs_info->fs_devices->device_list_mutex);
+	for (i = 0; i < map->num_stripes; i++) {
+		device = map->stripes[i].dev;
+		dev_offset = map->stripes[i].physical;
+
+		ret = insert_dev_extent(trans, device, chunk_offset, dev_offset,
+				       stripe_size);
+		if (ret)
+			break;
+	}
+	mutex_unlock(&fs_info->fs_devices->device_list_mutex);
+
+	free_extent_map(em);
+	return ret;
+}
+
 /*
  * This function, btrfs_create_pending_block_groups(), belongs to the phase 2 of
  * chunk allocation.
@@ -2278,8 +2386,8 @@ void btrfs_create_pending_block_groups(struct btrfs_trans_handle *trans)
 			if (ret)
 				btrfs_abort_transaction(trans, ret);
 		}
-		ret = btrfs_finish_chunk_alloc(trans, block_group->start,
-					block_group->length);
+		ret = insert_dev_extents(trans, block_group->start,
+					 block_group->length);
 		if (ret)
 			btrfs_abort_transaction(trans, ret);
 		add_block_group_free_space(trans, block_group);
diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h
index c652e19ad74e..76ee1452c57b 100644
--- a/fs/btrfs/btrfs_inode.h
+++ b/fs/btrfs/btrfs_inode.h
@@ -51,6 +51,13 @@ enum {
 	 * the file range, inode's io_tree).
 	 */
 	BTRFS_INODE_NO_DELALLOC_FLUSH,
+	/*
+	 * Set when we are working on enabling verity for a file. Computing and
+	 * writing the whole Merkle tree can take a while so we want to prevent
+	 * races where two separate tasks attempt to simultaneously start verity
+	 * on the same file.
+	 */
+	BTRFS_INODE_VERITY_IN_PROGRESS,
 };
 
 /* in memory btrfs inode */
@@ -189,8 +196,10 @@ struct btrfs_inode {
 	 */
 	u64 csum_bytes;
 
-	/* flags field from the on disk inode */
+	/* Backwards incompatible flags, lower half of inode_item::flags  */
 	u32 flags;
+	/* Read-only compatibility flags, upper half of inode_item::flags */
+	u32 ro_flags;
 
 	/*
 	 * Counters to keep track of the number of extent item's we may use due
@@ -348,6 +357,22 @@ struct btrfs_dio_private {
 	u8 csums[];
 };
 
+/*
+ * btrfs_inode_item stores flags in a u64, btrfs_inode stores them in two
+ * separate u32s. These two functions convert between the two representations.
+ */
+static inline u64 btrfs_inode_combine_flags(u32 flags, u32 ro_flags)
+{
+	return (flags | ((u64)ro_flags << 32));
+}
+
+static inline void btrfs_inode_split_flags(u64 inode_item_flags,
+					   u32 *flags, u32 *ro_flags)
+{
+	*flags = (u32)inode_item_flags;
+	*ro_flags = (u32)(inode_item_flags >> 32);
+}
+
 /* Array of bytes with variable length, hexadecimal format 0x1234 */
 #define CSUM_FMT				"0x%*phN"
 #define CSUM_FMT_VALUE(size, bytes)		size, bytes
diff --git a/fs/btrfs/check-integrity.c b/fs/btrfs/check-integrity.c
index 169508609324..86816088927f 100644
--- a/fs/btrfs/check-integrity.c
+++ b/fs/btrfs/check-integrity.c
@@ -243,47 +243,6 @@ struct btrfsic_state {
 	u32 datablock_size;
 };
 
-static void btrfsic_block_init(struct btrfsic_block *b);
-static struct btrfsic_block *btrfsic_block_alloc(void);
-static void btrfsic_block_free(struct btrfsic_block *b);
-static void btrfsic_block_link_init(struct btrfsic_block_link *n);
-static struct btrfsic_block_link *btrfsic_block_link_alloc(void);
-static void btrfsic_block_link_free(struct btrfsic_block_link *n);
-static void btrfsic_dev_state_init(struct btrfsic_dev_state *ds);
-static struct btrfsic_dev_state *btrfsic_dev_state_alloc(void);
-static void btrfsic_dev_state_free(struct btrfsic_dev_state *ds);
-static void btrfsic_block_hashtable_init(struct btrfsic_block_hashtable *h);
-static void btrfsic_block_hashtable_add(struct btrfsic_block *b,
-					struct btrfsic_block_hashtable *h);
-static void btrfsic_block_hashtable_remove(struct btrfsic_block *b);
-static struct btrfsic_block *btrfsic_block_hashtable_lookup(
-		struct block_device *bdev,
-		u64 dev_bytenr,
-		struct btrfsic_block_hashtable *h);
-static void btrfsic_block_link_hashtable_init(
-		struct btrfsic_block_link_hashtable *h);
-static void btrfsic_block_link_hashtable_add(
-		struct btrfsic_block_link *l,
-		struct btrfsic_block_link_hashtable *h);
-static void btrfsic_block_link_hashtable_remove(struct btrfsic_block_link *l);
-static struct btrfsic_block_link *btrfsic_block_link_hashtable_lookup(
-		struct block_device *bdev_ref_to,
-		u64 dev_bytenr_ref_to,
-		struct block_device *bdev_ref_from,
-		u64 dev_bytenr_ref_from,
-		struct btrfsic_block_link_hashtable *h);
-static void btrfsic_dev_state_hashtable_init(
-		struct btrfsic_dev_state_hashtable *h);
-static void btrfsic_dev_state_hashtable_add(
-		struct btrfsic_dev_state *ds,
-		struct btrfsic_dev_state_hashtable *h);
-static void btrfsic_dev_state_hashtable_remove(struct btrfsic_dev_state *ds);
-static struct btrfsic_dev_state *btrfsic_dev_state_hashtable_lookup(dev_t dev,
-		struct btrfsic_dev_state_hashtable *h);
-static struct btrfsic_stack_frame *btrfsic_stack_frame_alloc(void);
-static void btrfsic_stack_frame_free(struct btrfsic_stack_frame *sf);
-static int btrfsic_process_superblock(struct btrfsic_state *state,
-				      struct btrfs_fs_devices *fs_devices);
 static int btrfsic_process_metablock(struct btrfsic_state *state,
 				     struct btrfsic_block *block,
 				     struct btrfsic_block_data_ctx *block_ctx,
@@ -313,14 +272,6 @@ static int btrfsic_map_block(struct btrfsic_state *state, u64 bytenr, u32 len,
 static void btrfsic_release_block_ctx(struct btrfsic_block_data_ctx *block_ctx);
 static int btrfsic_read_block(struct btrfsic_state *state,
 			      struct btrfsic_block_data_ctx *block_ctx);
-static void btrfsic_dump_database(struct btrfsic_state *state);
-static int btrfsic_test_for_metadata(struct btrfsic_state *state,
-				     char **datav, unsigned int num_pages);
-static void btrfsic_process_written_block(struct btrfsic_dev_state *dev_state,
-					  u64 dev_bytenr, char **mapped_datav,
-					  unsigned int num_pages,
-					  struct bio *bio, int *bio_is_patched,
-					  int submit_bio_bh_rw);
 static int btrfsic_process_written_superblock(
 		struct btrfsic_state *state,
 		struct btrfsic_block *const block,
@@ -1558,10 +1509,8 @@ static void btrfsic_release_block_ctx(struct btrfsic_block_data_ctx *block_ctx)
 		/* Pages must be unmapped in reverse order */
 		while (num_pages > 0) {
 			num_pages--;
-			if (block_ctx->datav[num_pages]) {
-				kunmap_local(block_ctx->datav[num_pages]);
+			if (block_ctx->datav[num_pages])
 				block_ctx->datav[num_pages] = NULL;
-			}
 			if (block_ctx->pagev[num_pages]) {
 				__free_page(block_ctx->pagev[num_pages]);
 				block_ctx->pagev[num_pages] = NULL;
@@ -1638,7 +1587,7 @@ static int btrfsic_read_block(struct btrfsic_state *state,
 		i = j;
 	}
 	for (i = 0; i < num_pages; i++)
-		block_ctx->datav[i] = kmap_local_page(block_ctx->pagev[i]);
+		block_ctx->datav[i] = page_address(block_ctx->pagev[i]);
 
 	return block_ctx->len;
 }
@@ -2703,7 +2652,7 @@ static void __btrfsic_submit_bio(struct bio *bio)
 
 		bio_for_each_segment(bvec, bio, iter) {
 			BUG_ON(bvec.bv_len != PAGE_SIZE);
-			mapped_datav[i] = kmap_local_page(bvec.bv_page);
+			mapped_datav[i] = page_address(bvec.bv_page);
 			i++;
 
 			if (dev_state->state->print_mask &
@@ -2716,9 +2665,6 @@ static void __btrfsic_submit_bio(struct bio *bio)
 					      mapped_datav, segs,
 					      bio, &bio_is_patched,
 					      bio->bi_opf);
-		/* Unmap in reverse order */
-		for (--i; i >= 0; i--)
-			kunmap_local(mapped_datav[i]);
 		kfree(mapped_datav);
 	} else if (NULL != dev_state && (bio->bi_opf & REQ_PREFLUSH)) {
 		if (dev_state->state->print_mask &
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index 30d82cdf128c..7869ad12bc6e 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -172,10 +172,9 @@ static int check_compressed_csum(struct btrfs_inode *inode, struct bio *bio,
 		/* Hash through the page sector by sector */
 		for (pg_offset = 0; pg_offset < bytes_left;
 		     pg_offset += sectorsize) {
-			kaddr = kmap_atomic(page);
+			kaddr = page_address(page);
 			crypto_shash_digest(shash, kaddr + pg_offset,
 					    sectorsize, csum);
-			kunmap_atomic(kaddr);
 
 			if (memcmp(&csum, cb_sum, csum_size) != 0) {
 				btrfs_print_data_csum_error(inode, disk_start,
@@ -565,6 +564,16 @@ static noinline int add_ra_bio_pages(struct inode *inode,
 	if (isize == 0)
 		return 0;
 
+	/*
+	 * For current subpage support, we only support 64K page size,
+	 * which means maximum compressed extent size (128K) is just 2x page
+	 * size.
+	 * This makes readahead less effective, so here disable readahead for
+	 * subpage for now, until full compressed write is supported.
+	 */
+	if (btrfs_sb(inode->i_sb)->sectorsize < PAGE_SIZE)
+		return 0;
+
 	end_index = (i_size_read(inode) - 1) >> PAGE_SHIFT;
 
 	while (last_offset < compressed_end) {
@@ -673,6 +682,7 @@ blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
 	struct page *page;
 	struct bio *comp_bio;
 	u64 cur_disk_byte = bio->bi_iter.bi_sector << 9;
+	u64 file_offset;
 	u64 em_len;
 	u64 em_start;
 	struct extent_map *em;
@@ -682,15 +692,17 @@ blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
 
 	em_tree = &BTRFS_I(inode)->extent_tree;
 
+	file_offset = bio_first_bvec_all(bio)->bv_offset +
+		      page_offset(bio_first_page_all(bio));
+
 	/* we need the actual starting offset of this extent in the file */
 	read_lock(&em_tree->lock);
-	em = lookup_extent_mapping(em_tree,
-				   page_offset(bio_first_page_all(bio)),
-				   fs_info->sectorsize);
+	em = lookup_extent_mapping(em_tree, file_offset, fs_info->sectorsize);
 	read_unlock(&em_tree->lock);
 	if (!em)
 		return BLK_STS_IOERR;
 
+	ASSERT(em->compress_type != BTRFS_COMPRESS_NONE);
 	compressed_len = em->block_len;
 	cb = kmalloc(compressed_bio_size(fs_info, compressed_len), GFP_NOFS);
 	if (!cb)
@@ -721,8 +733,7 @@ blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
 		goto fail1;
 
 	for (pg_index = 0; pg_index < nr_pages; pg_index++) {
-		cb->compressed_pages[pg_index] = alloc_page(GFP_NOFS |
-							      __GFP_HIGHMEM);
+		cb->compressed_pages[pg_index] = alloc_page(GFP_NOFS);
 		if (!cb->compressed_pages[pg_index]) {
 			faili = pg_index - 1;
 			ret = BLK_STS_RESOURCE;
@@ -1261,96 +1272,82 @@ void __cold btrfs_exit_compress(void)
 }
 
 /*
- * Copy uncompressed data from working buffer to pages.
+ * Copy decompressed data from working buffer to pages.
+ *
+ * @buf:		The decompressed data buffer
+ * @buf_len:		The decompressed data length
+ * @decompressed:	Number of bytes that are already decompressed inside the
+ * 			compressed extent
+ * @cb:			The compressed extent descriptor
+ * @orig_bio:		The original bio that the caller wants to read for
+ *
+ * An easier to understand graph is like below:
+ *
+ * 		|<- orig_bio ->|     |<- orig_bio->|
+ * 	|<-------      full decompressed extent      ----->|
+ * 	|<-----------    @cb range   ---->|
+ * 	|			|<-- @buf_len -->|
+ * 	|<--- @decompressed --->|
+ *
+ * Note that, @cb can be a subpage of the full decompressed extent, but
+ * @cb->start always has the same as the orig_file_offset value of the full
+ * decompressed extent.
  *
- * buf_start is the byte offset we're of the start of our workspace buffer.
+ * When reading compressed extent, we have to read the full compressed extent,
+ * while @orig_bio may only want part of the range.
+ * Thus this function will ensure only data covered by @orig_bio will be copied
+ * to.
  *
- * total_out is the last byte of the buffer
+ * Return 0 if we have copied all needed contents for @orig_bio.
+ * Return >0 if we need continue decompress.
  */
-int btrfs_decompress_buf2page(const char *buf, unsigned long buf_start,
-			      unsigned long total_out, u64 disk_start,
-			      struct bio *bio)
+int btrfs_decompress_buf2page(const char *buf, u32 buf_len,
+			      struct compressed_bio *cb, u32 decompressed)
 {
-	unsigned long buf_offset;
-	unsigned long current_buf_start;
-	unsigned long start_byte;
-	unsigned long prev_start_byte;
-	unsigned long working_bytes = total_out - buf_start;
-	unsigned long bytes;
-	struct bio_vec bvec = bio_iter_iovec(bio, bio->bi_iter);
-
-	/*
-	 * start byte is the first byte of the page we're currently
-	 * copying into relative to the start of the compressed data.
-	 */
-	start_byte = page_offset(bvec.bv_page) - disk_start;
-
-	/* we haven't yet hit data corresponding to this page */
-	if (total_out <= start_byte)
-		return 1;
-
-	/*
-	 * the start of the data we care about is offset into
-	 * the middle of our working buffer
-	 */
-	if (total_out > start_byte && buf_start < start_byte) {
-		buf_offset = start_byte - buf_start;
-		working_bytes -= buf_offset;
-	} else {
-		buf_offset = 0;
-	}
-	current_buf_start = buf_start;
-
-	/* copy bytes from the working buffer into the pages */
-	while (working_bytes > 0) {
-		bytes = min_t(unsigned long, bvec.bv_len,
-				PAGE_SIZE - (buf_offset % PAGE_SIZE));
-		bytes = min(bytes, working_bytes);
-
-		memcpy_to_page(bvec.bv_page, bvec.bv_offset, buf + buf_offset,
-			       bytes);
-		flush_dcache_page(bvec.bv_page);
+	struct bio *orig_bio = cb->orig_bio;
+	/* Offset inside the full decompressed extent */
+	u32 cur_offset;
+
+	cur_offset = decompressed;
+	/* The main loop to do the copy */
+	while (cur_offset < decompressed + buf_len) {
+		struct bio_vec bvec;
+		size_t copy_len;
+		u32 copy_start;
+		/* Offset inside the full decompressed extent */
+		u32 bvec_offset;
+
+		bvec = bio_iter_iovec(orig_bio, orig_bio->bi_iter);
+		/*
+		 * cb->start may underflow, but subtracting that value can still
+		 * give us correct offset inside the full decompressed extent.
+		 */
+		bvec_offset = page_offset(bvec.bv_page) + bvec.bv_offset - cb->start;
 
-		buf_offset += bytes;
-		working_bytes -= bytes;
-		current_buf_start += bytes;
+		/* Haven't reached the bvec range, exit */
+		if (decompressed + buf_len <= bvec_offset)
+			return 1;
 
-		/* check if we need to pick another page */
-		bio_advance(bio, bytes);
-		if (!bio->bi_iter.bi_size)
-			return 0;
-		bvec = bio_iter_iovec(bio, bio->bi_iter);
-		prev_start_byte = start_byte;
-		start_byte = page_offset(bvec.bv_page) - disk_start;
+		copy_start = max(cur_offset, bvec_offset);
+		copy_len = min(bvec_offset + bvec.bv_len,
+			       decompressed + buf_len) - copy_start;
+		ASSERT(copy_len);
 
 		/*
-		 * We need to make sure we're only adjusting
-		 * our offset into compression working buffer when
-		 * we're switching pages.  Otherwise we can incorrectly
-		 * keep copying when we were actually done.
+		 * Extra range check to ensure we didn't go beyond
+		 * @buf + @buf_len.
 		 */
-		if (start_byte != prev_start_byte) {
-			/*
-			 * make sure our new page is covered by this
-			 * working buffer
-			 */
-			if (total_out <= start_byte)
-				return 1;
+		ASSERT(copy_start - decompressed < buf_len);
+		memcpy_to_page(bvec.bv_page, bvec.bv_offset,
+			       buf + copy_start - decompressed, copy_len);
+		flush_dcache_page(bvec.bv_page);
+		cur_offset += copy_len;
 
-			/*
-			 * the next page in the biovec might not be adjacent
-			 * to the last page, but it might still be found
-			 * inside this working buffer. bump our offset pointer
-			 */
-			if (total_out > start_byte &&
-			    current_buf_start < start_byte) {
-				buf_offset = start_byte - buf_start;
-				working_bytes = total_out - start_byte;
-				current_buf_start = buf_start + buf_offset;
-			}
-		}
+		bio_advance(orig_bio, copy_len);
+		/* Finished the bio */
+		if (!orig_bio->bi_iter.bi_size)
+			return 0;
 	}
-
 	return 1;
 }
 
diff --git a/fs/btrfs/compression.h b/fs/btrfs/compression.h
index c359f20920d0..399be0b435bf 100644
--- a/fs/btrfs/compression.h
+++ b/fs/btrfs/compression.h
@@ -86,9 +86,8 @@ int btrfs_compress_pages(unsigned int type_level, struct address_space *mapping,
 			 unsigned long *total_out);
 int btrfs_decompress(int type, unsigned char *data_in, struct page *dest_page,
 		     unsigned long start_byte, size_t srclen, size_t destlen);
-int btrfs_decompress_buf2page(const char *buf, unsigned long buf_start,
-			      unsigned long total_out, u64 disk_start,
-			      struct bio *bio);
+int btrfs_decompress_buf2page(const char *buf, u32 buf_len,
+			      struct compressed_bio *cb, u32 decompressed);
 
 blk_status_t btrfs_submit_compressed_write(struct btrfs_inode *inode, u64 start,
 				  unsigned int len, u64 disk_start,
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index c5c08c87e130..84627cbd5b5b 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -726,21 +726,21 @@ int btrfs_realloc_node(struct btrfs_trans_handle *trans,
 
 /*
  * search for key in the extent_buffer.  The items start at offset p,
- * and they are item_size apart.  There are 'max' items in p.
+ * and they are item_size apart.
  *
  * the slot in the array is returned via slot, and it points to
  * the place where you would insert key if it is not found in
  * the array.
  *
- * slot may point to max if the key is bigger than all of the keys
+ * Slot may point to total number of items if the key is bigger than
+ * all of the keys
  */
 static noinline int generic_bin_search(struct extent_buffer *eb,
 				       unsigned long p, int item_size,
-				       const struct btrfs_key *key,
-				       int max, int *slot)
+				       const struct btrfs_key *key, int *slot)
 {
 	int low = 0;
-	int high = max;
+	int high = btrfs_header_nritems(eb);
 	int ret;
 	const int key_size = sizeof(struct btrfs_disk_key);
 
@@ -799,15 +799,11 @@ int btrfs_bin_search(struct extent_buffer *eb, const struct btrfs_key *key,
 	if (btrfs_header_level(eb) == 0)
 		return generic_bin_search(eb,
 					  offsetof(struct btrfs_leaf, items),
-					  sizeof(struct btrfs_item),
-					  key, btrfs_header_nritems(eb),
-					  slot);
+					  sizeof(struct btrfs_item), key, slot);
 	else
 		return generic_bin_search(eb,
 					  offsetof(struct btrfs_node, ptrs),
-					  sizeof(struct btrfs_key_ptr),
-					  key, btrfs_header_nritems(eb),
-					  slot);
+					  sizeof(struct btrfs_key_ptr), key, slot);
 }
 
 static void root_add_used(struct btrfs_root *root, u32 size)
@@ -1237,7 +1233,6 @@ static void reada_for_search(struct btrfs_fs_info *fs_info,
 	u64 target;
 	u64 nread = 0;
 	u64 nread_max;
-	struct extent_buffer *eb;
 	u32 nr;
 	u32 blocksize;
 	u32 nscan = 0;
@@ -1266,10 +1261,14 @@ static void reada_for_search(struct btrfs_fs_info *fs_info,
 
 	search = btrfs_node_blockptr(node, slot);
 	blocksize = fs_info->nodesize;
-	eb = find_extent_buffer(fs_info, search);
-	if (eb) {
-		free_extent_buffer(eb);
-		return;
+	if (path->reada != READA_FORWARD_ALWAYS) {
+		struct extent_buffer *eb;
+
+		eb = find_extent_buffer(fs_info, search);
+		if (eb) {
+			free_extent_buffer(eb);
+			return;
+		}
 	}
 
 	target = search;
@@ -2103,6 +2102,27 @@ again:
 }
 
 /*
+ * Execute search and call btrfs_previous_item to traverse backwards if the item
+ * was not found.
+ *
+ * Return 0 if found, 1 if not found and < 0 if error.
+ */
+int btrfs_search_backwards(struct btrfs_root *root, struct btrfs_key *key,
+			   struct btrfs_path *path)
+{
+	int ret;
+
+	ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
+	if (ret > 0)
+		ret = btrfs_previous_item(root, path, key->objectid, key->type);
+
+	if (ret == 0)
+		btrfs_item_key_to_cpu(path->nodes[0], key, path->slots[0]);
+
+	return ret;
+}
+
+/*
  * adjust the pointers going up the tree, starting at level
  * making sure the right key of each node is points to 'key'.
  * This is used after shifting pointers to the left, so it stops
@@ -4358,16 +4378,6 @@ next:
 	return 1;
 }
 
-/*
- * search the tree again to find a leaf with greater keys
- * returns 0 if it found something or 1 if there are no greater leaves.
- * returns < 0 on io errors.
- */
-int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path)
-{
-	return btrfs_next_old_leaf(root, path, 0);
-}
-
 int btrfs_next_old_leaf(struct btrfs_root *root, struct btrfs_path *path,
 			u64 time_seq)
 {
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index e5e53e592d4f..f07c82fafa04 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -281,7 +281,8 @@ struct btrfs_super_block {
 
 #define BTRFS_FEATURE_COMPAT_RO_SUPP			\
 	(BTRFS_FEATURE_COMPAT_RO_FREE_SPACE_TREE |	\
-	 BTRFS_FEATURE_COMPAT_RO_FREE_SPACE_TREE_VALID)
+	 BTRFS_FEATURE_COMPAT_RO_FREE_SPACE_TREE_VALID | \
+	 BTRFS_FEATURE_COMPAT_RO_VERITY)
 
 #define BTRFS_FEATURE_COMPAT_RO_SAFE_SET	0ULL
 #define BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR	0ULL
@@ -1012,8 +1013,6 @@ struct btrfs_fs_info {
 		u64 zoned;
 	};
 
-	/* Max size to emit ZONE_APPEND write command */
-	u64 max_zone_append_size;
 	struct mutex zoned_meta_io_lock;
 	spinlock_t treelog_bg_lock;
 	u64 treelog_bg;
@@ -1484,20 +1483,20 @@ do {                                                                   \
 /*
  * Inode flags
  */
-#define BTRFS_INODE_NODATASUM		(1 << 0)
-#define BTRFS_INODE_NODATACOW		(1 << 1)
-#define BTRFS_INODE_READONLY		(1 << 2)
-#define BTRFS_INODE_NOCOMPRESS		(1 << 3)
-#define BTRFS_INODE_PREALLOC		(1 << 4)
-#define BTRFS_INODE_SYNC		(1 << 5)
-#define BTRFS_INODE_IMMUTABLE		(1 << 6)
-#define BTRFS_INODE_APPEND		(1 << 7)
-#define BTRFS_INODE_NODUMP		(1 << 8)
-#define BTRFS_INODE_NOATIME		(1 << 9)
-#define BTRFS_INODE_DIRSYNC		(1 << 10)
-#define BTRFS_INODE_COMPRESS		(1 << 11)
-
-#define BTRFS_INODE_ROOT_ITEM_INIT	(1 << 31)
+#define BTRFS_INODE_NODATASUM		(1U << 0)
+#define BTRFS_INODE_NODATACOW		(1U << 1)
+#define BTRFS_INODE_READONLY		(1U << 2)
+#define BTRFS_INODE_NOCOMPRESS		(1U << 3)
+#define BTRFS_INODE_PREALLOC		(1U << 4)
+#define BTRFS_INODE_SYNC		(1U << 5)
+#define BTRFS_INODE_IMMUTABLE		(1U << 6)
+#define BTRFS_INODE_APPEND		(1U << 7)
+#define BTRFS_INODE_NODUMP		(1U << 8)
+#define BTRFS_INODE_NOATIME		(1U << 9)
+#define BTRFS_INODE_DIRSYNC		(1U << 10)
+#define BTRFS_INODE_COMPRESS		(1U << 11)
+
+#define BTRFS_INODE_ROOT_ITEM_INIT	(1U << 31)
 
 #define BTRFS_INODE_FLAG_MASK						\
 	(BTRFS_INODE_NODATASUM |					\
@@ -1514,6 +1513,10 @@ do {                                                                   \
 	 BTRFS_INODE_COMPRESS |						\
 	 BTRFS_INODE_ROOT_ITEM_INIT)
 
+#define BTRFS_INODE_RO_VERITY		(1U << 0)
+
+#define BTRFS_INODE_RO_FLAG_MASK	(BTRFS_INODE_RO_VERITY)
+
 struct btrfs_map_token {
 	struct extent_buffer *eb;
 	char *kaddr;
@@ -2781,10 +2784,11 @@ enum btrfs_flush_state {
 	FLUSH_DELAYED_REFS	=	4,
 	FLUSH_DELALLOC		=	5,
 	FLUSH_DELALLOC_WAIT	=	6,
-	ALLOC_CHUNK		=	7,
-	ALLOC_CHUNK_FORCE	=	8,
-	RUN_DELAYED_IPUTS	=	9,
-	COMMIT_TRANS		=	10,
+	FLUSH_DELALLOC_FULL	=	7,
+	ALLOC_CHUNK		=	8,
+	ALLOC_CHUNK_FORCE	=	9,
+	RUN_DELAYED_IPUTS	=	10,
+	COMMIT_TRANS		=	11,
 };
 
 int btrfs_subvolume_reserve_metadata(struct btrfs_root *root,
@@ -2901,10 +2905,13 @@ static inline int btrfs_insert_empty_item(struct btrfs_trans_handle *trans,
 	return btrfs_insert_empty_items(trans, root, path, key, &data_size, 1);
 }
 
-int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path);
 int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path);
 int btrfs_next_old_leaf(struct btrfs_root *root, struct btrfs_path *path,
 			u64 time_seq);
+
+int btrfs_search_backwards(struct btrfs_root *root, struct btrfs_key *key,
+			   struct btrfs_path *path);
+
 static inline int btrfs_next_old_item(struct btrfs_root *root,
 				      struct btrfs_path *p, u64 time_seq)
 {
@@ -2913,6 +2920,18 @@ static inline int btrfs_next_old_item(struct btrfs_root *root,
 		return btrfs_next_old_leaf(root, p, time_seq);
 	return 0;
 }
+
+/*
+ * Search the tree again to find a leaf with greater keys.
+ *
+ * Returns 0 if it found something or 1 if there are no greater leaves.
+ * Returns < 0 on error.
+ */
+static inline int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path)
+{
+	return btrfs_next_old_leaf(root, path, 0);
+}
+
 static inline int btrfs_next_item(struct btrfs_root *root, struct btrfs_path *p)
 {
 	return btrfs_next_old_item(root, p, 0);
@@ -3145,7 +3164,8 @@ int btrfs_set_extent_delalloc(struct btrfs_inode *inode, u64 start, u64 end,
 			      struct extent_state **cached_state);
 int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
 			     struct btrfs_root *new_root,
-			     struct btrfs_root *parent_root);
+			     struct btrfs_root *parent_root,
+			     struct user_namespace *mnt_userns);
  void btrfs_set_delalloc_extent(struct inode *inode, struct extent_state *state,
 			       unsigned *bits);
 void btrfs_clear_delalloc_extent(struct inode *inode,
@@ -3194,10 +3214,10 @@ int btrfs_prealloc_file_range_trans(struct inode *inode,
 int btrfs_run_delalloc_range(struct btrfs_inode *inode, struct page *locked_page,
 		u64 start, u64 end, int *page_started, unsigned long *nr_written,
 		struct writeback_control *wbc);
-int btrfs_writepage_cow_fixup(struct page *page, u64 start, u64 end);
+int btrfs_writepage_cow_fixup(struct page *page);
 void btrfs_writepage_endio_finish_ordered(struct btrfs_inode *inode,
 					  struct page *page, u64 start,
-					  u64 end, int uptodate);
+					  u64 end, bool uptodate);
 extern const struct dentry_operations btrfs_dentry_operations;
 extern const struct iomap_ops btrfs_dio_iomap_ops;
 extern const struct iomap_dio_ops btrfs_dio_ops;
@@ -3779,6 +3799,30 @@ static inline int btrfs_defrag_cancelled(struct btrfs_fs_info *fs_info)
 	return signal_pending(current);
 }
 
+/* verity.c */
+#ifdef CONFIG_FS_VERITY
+
+extern const struct fsverity_operations btrfs_verityops;
+int btrfs_drop_verity_items(struct btrfs_inode *inode);
+
+BTRFS_SETGET_FUNCS(verity_descriptor_encryption, struct btrfs_verity_descriptor_item,
+		   encryption, 8);
+BTRFS_SETGET_FUNCS(verity_descriptor_size, struct btrfs_verity_descriptor_item,
+		   size, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_verity_descriptor_encryption,
+			 struct btrfs_verity_descriptor_item, encryption, 8);
+BTRFS_SETGET_STACK_FUNCS(stack_verity_descriptor_size,
+			 struct btrfs_verity_descriptor_item, size, 64);
+
+#else
+
+static inline int btrfs_drop_verity_items(struct btrfs_inode *inode)
+{
+	return 0;
+}
+
+#endif
+
 /* Sanity test specific functions */
 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
 void btrfs_test_destroy_inode(struct inode *inode);
diff --git a/fs/btrfs/delayed-inode.c b/fs/btrfs/delayed-inode.c
index 257c1e18abd4..1e08eb2b27f0 100644
--- a/fs/btrfs/delayed-inode.c
+++ b/fs/btrfs/delayed-inode.c
@@ -6,7 +6,6 @@
 
 #include <linux/slab.h>
 #include <linux/iversion.h>
-#include <linux/sched/mm.h>
 #include "misc.h"
 #include "delayed-inode.h"
 #include "disk-io.h"
@@ -672,176 +671,119 @@ static void btrfs_delayed_inode_release_metadata(struct btrfs_fs_info *fs_info,
 }
 
 /*
- * This helper will insert some continuous items into the same leaf according
- * to the free space of the leaf.
+ * Insert a single delayed item or a batch of delayed items that have consecutive
+ * keys if they exist.
  */
-static int btrfs_batch_insert_items(struct btrfs_root *root,
-				    struct btrfs_path *path,
-				    struct btrfs_delayed_item *item)
+static int btrfs_insert_delayed_item(struct btrfs_trans_handle *trans,
+				     struct btrfs_root *root,
+				     struct btrfs_path *path,
+				     struct btrfs_delayed_item *first_item)
 {
-	struct btrfs_delayed_item *curr, *next;
-	int free_space;
-	int total_size = 0;
-	struct extent_buffer *leaf;
-	char *data_ptr;
-	struct btrfs_key *keys;
-	u32 *data_size;
-	struct list_head head;
-	int slot;
+	LIST_HEAD(batch);
+	struct btrfs_delayed_item *curr;
+	struct btrfs_delayed_item *next;
+	const int max_size = BTRFS_LEAF_DATA_SIZE(root->fs_info);
+	int total_size;
 	int nitems;
-	int i;
-	int ret = 0;
-
-	BUG_ON(!path->nodes[0]);
+	char *ins_data = NULL;
+	struct btrfs_key *ins_keys;
+	u32 *ins_sizes;
+	int ret;
 
-	leaf = path->nodes[0];
-	free_space = btrfs_leaf_free_space(leaf);
-	INIT_LIST_HEAD(&head);
+	list_add_tail(&first_item->tree_list, &batch);
+	nitems = 1;
+	total_size = first_item->data_len + sizeof(struct btrfs_item);
+	curr = first_item;
 
-	next = item;
-	nitems = 0;
+	while (true) {
+		int next_size;
 
-	/*
-	 * count the number of the continuous items that we can insert in batch
-	 */
-	while (total_size + next->data_len + sizeof(struct btrfs_item) <=
-	       free_space) {
-		total_size += next->data_len + sizeof(struct btrfs_item);
-		list_add_tail(&next->tree_list, &head);
-		nitems++;
-
-		curr = next;
 		next = __btrfs_next_delayed_item(curr);
-		if (!next)
+		if (!next || !btrfs_is_continuous_delayed_item(curr, next))
 			break;
 
-		if (!btrfs_is_continuous_delayed_item(curr, next))
+		next_size = next->data_len + sizeof(struct btrfs_item);
+		if (total_size + next_size > max_size)
 			break;
-	}
 
-	if (!nitems) {
-		ret = 0;
-		goto out;
+		list_add_tail(&next->tree_list, &batch);
+		nitems++;
+		total_size += next_size;
+		curr = next;
 	}
 
-	keys = kmalloc_array(nitems, sizeof(struct btrfs_key), GFP_NOFS);
-	if (!keys) {
-		ret = -ENOMEM;
-		goto out;
-	}
+	if (nitems == 1) {
+		ins_keys = &first_item->key;
+		ins_sizes = &first_item->data_len;
+	} else {
+		int i = 0;
 
-	data_size = kmalloc_array(nitems, sizeof(u32), GFP_NOFS);
-	if (!data_size) {
-		ret = -ENOMEM;
-		goto error;
+		ins_data = kmalloc(nitems * sizeof(u32) +
+				   nitems * sizeof(struct btrfs_key), GFP_NOFS);
+		if (!ins_data) {
+			ret = -ENOMEM;
+			goto out;
+		}
+		ins_sizes = (u32 *)ins_data;
+		ins_keys = (struct btrfs_key *)(ins_data + nitems * sizeof(u32));
+		list_for_each_entry(curr, &batch, tree_list) {
+			ins_keys[i] = curr->key;
+			ins_sizes[i] = curr->data_len;
+			i++;
+		}
 	}
 
-	/* get keys of all the delayed items */
-	i = 0;
-	list_for_each_entry(next, &head, tree_list) {
-		keys[i] = next->key;
-		data_size[i] = next->data_len;
-		i++;
-	}
+	ret = btrfs_insert_empty_items(trans, root, path, ins_keys, ins_sizes,
+				       nitems);
+	if (ret)
+		goto out;
 
-	/* insert the keys of the items */
-	setup_items_for_insert(root, path, keys, data_size, nitems);
+	list_for_each_entry(curr, &batch, tree_list) {
+		char *data_ptr;
 
-	/* insert the dir index items */
-	slot = path->slots[0];
-	list_for_each_entry_safe(curr, next, &head, tree_list) {
-		data_ptr = btrfs_item_ptr(leaf, slot, char);
-		write_extent_buffer(leaf, &curr->data,
-				    (unsigned long)data_ptr,
-				    curr->data_len);
-		slot++;
+		data_ptr = btrfs_item_ptr(path->nodes[0], path->slots[0], char);
+		write_extent_buffer(path->nodes[0], &curr->data,
+				    (unsigned long)data_ptr, curr->data_len);
+		path->slots[0]++;
+	}
 
-		btrfs_delayed_item_release_metadata(root, curr);
+	/*
+	 * Now release our path before releasing the delayed items and their
+	 * metadata reservations, so that we don't block other tasks for more
+	 * time than needed.
+	 */
+	btrfs_release_path(path);
 
+	list_for_each_entry_safe(curr, next, &batch, tree_list) {
 		list_del(&curr->tree_list);
+		btrfs_delayed_item_release_metadata(root, curr);
 		btrfs_release_delayed_item(curr);
 	}
-
-error:
-	kfree(data_size);
-	kfree(keys);
 out:
+	kfree(ins_data);
 	return ret;
 }
 
-/*
- * This helper can just do simple insertion that needn't extend item for new
- * data, such as directory name index insertion, inode insertion.
- */
-static int btrfs_insert_delayed_item(struct btrfs_trans_handle *trans,
-				     struct btrfs_root *root,
-				     struct btrfs_path *path,
-				     struct btrfs_delayed_item *delayed_item)
-{
-	struct extent_buffer *leaf;
-	unsigned int nofs_flag;
-	char *ptr;
-	int ret;
-
-	nofs_flag = memalloc_nofs_save();
-	ret = btrfs_insert_empty_item(trans, root, path, &delayed_item->key,
-				      delayed_item->data_len);
-	memalloc_nofs_restore(nofs_flag);
-	if (ret < 0 && ret != -EEXIST)
-		return ret;
-
-	leaf = path->nodes[0];
-
-	ptr = btrfs_item_ptr(leaf, path->slots[0], char);
-
-	write_extent_buffer(leaf, delayed_item->data, (unsigned long)ptr,
-			    delayed_item->data_len);
-	btrfs_mark_buffer_dirty(leaf);
-
-	btrfs_delayed_item_release_metadata(root, delayed_item);
-	return 0;
-}
-
-/*
- * we insert an item first, then if there are some continuous items, we try
- * to insert those items into the same leaf.
- */
 static int btrfs_insert_delayed_items(struct btrfs_trans_handle *trans,
 				      struct btrfs_path *path,
 				      struct btrfs_root *root,
 				      struct btrfs_delayed_node *node)
 {
-	struct btrfs_delayed_item *curr, *prev;
 	int ret = 0;
 
-do_again:
-	mutex_lock(&node->mutex);
-	curr = __btrfs_first_delayed_insertion_item(node);
-	if (!curr)
-		goto insert_end;
-
-	ret = btrfs_insert_delayed_item(trans, root, path, curr);
-	if (ret < 0) {
-		btrfs_release_path(path);
-		goto insert_end;
-	}
+	while (ret == 0) {
+		struct btrfs_delayed_item *curr;
 
-	prev = curr;
-	curr = __btrfs_next_delayed_item(prev);
-	if (curr && btrfs_is_continuous_delayed_item(prev, curr)) {
-		/* insert the continuous items into the same leaf */
-		path->slots[0]++;
-		btrfs_batch_insert_items(root, path, curr);
+		mutex_lock(&node->mutex);
+		curr = __btrfs_first_delayed_insertion_item(node);
+		if (!curr) {
+			mutex_unlock(&node->mutex);
+			break;
+		}
+		ret = btrfs_insert_delayed_item(trans, root, path, curr);
+		mutex_unlock(&node->mutex);
 	}
-	btrfs_release_delayed_item(prev);
-	btrfs_mark_buffer_dirty(path->nodes[0]);
 
-	btrfs_release_path(path);
-	mutex_unlock(&node->mutex);
-	goto do_again;
-
-insert_end:
-	mutex_unlock(&node->mutex);
 	return ret;
 }
 
@@ -914,7 +856,6 @@ static int btrfs_delete_delayed_items(struct btrfs_trans_handle *trans,
 				      struct btrfs_delayed_node *node)
 {
 	struct btrfs_delayed_item *curr, *prev;
-	unsigned int nofs_flag;
 	int ret = 0;
 
 do_again:
@@ -923,9 +864,7 @@ do_again:
 	if (!curr)
 		goto delete_fail;
 
-	nofs_flag = memalloc_nofs_save();
 	ret = btrfs_search_slot(trans, root, &curr->key, path, -1, 1);
-	memalloc_nofs_restore(nofs_flag);
 	if (ret < 0)
 		goto delete_fail;
 	else if (ret > 0) {
@@ -994,7 +933,6 @@ static int __btrfs_update_delayed_inode(struct btrfs_trans_handle *trans,
 	struct btrfs_key key;
 	struct btrfs_inode_item *inode_item;
 	struct extent_buffer *leaf;
-	unsigned int nofs_flag;
 	int mod;
 	int ret;
 
@@ -1007,9 +945,7 @@ static int __btrfs_update_delayed_inode(struct btrfs_trans_handle *trans,
 	else
 		mod = 1;
 
-	nofs_flag = memalloc_nofs_save();
 	ret = btrfs_lookup_inode(trans, root, path, &key, mod);
-	memalloc_nofs_restore(nofs_flag);
 	if (ret > 0)
 		ret = -ENOENT;
 	if (ret < 0)
@@ -1066,9 +1002,7 @@ search:
 	key.type = BTRFS_INODE_EXTREF_KEY;
 	key.offset = -1;
 
-	nofs_flag = memalloc_nofs_save();
 	ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
-	memalloc_nofs_restore(nofs_flag);
 	if (ret < 0)
 		goto err_out;
 	ASSERT(ret);
@@ -1711,6 +1645,8 @@ static void fill_stack_inode_item(struct btrfs_trans_handle *trans,
 				  struct btrfs_inode_item *inode_item,
 				  struct inode *inode)
 {
+	u64 flags;
+
 	btrfs_set_stack_inode_uid(inode_item, i_uid_read(inode));
 	btrfs_set_stack_inode_gid(inode_item, i_gid_read(inode));
 	btrfs_set_stack_inode_size(inode_item, BTRFS_I(inode)->disk_i_size);
@@ -1723,7 +1659,9 @@ static void fill_stack_inode_item(struct btrfs_trans_handle *trans,
 				       inode_peek_iversion(inode));
 	btrfs_set_stack_inode_transid(inode_item, trans->transid);
 	btrfs_set_stack_inode_rdev(inode_item, inode->i_rdev);
-	btrfs_set_stack_inode_flags(inode_item, BTRFS_I(inode)->flags);
+	flags = btrfs_inode_combine_flags(BTRFS_I(inode)->flags,
+					  BTRFS_I(inode)->ro_flags);
+	btrfs_set_stack_inode_flags(inode_item, flags);
 	btrfs_set_stack_inode_block_group(inode_item, 0);
 
 	btrfs_set_stack_timespec_sec(&inode_item->atime,
@@ -1781,7 +1719,8 @@ int btrfs_fill_inode(struct inode *inode, u32 *rdev)
 				   btrfs_stack_inode_sequence(inode_item));
 	inode->i_rdev = 0;
 	*rdev = btrfs_stack_inode_rdev(inode_item);
-	BTRFS_I(inode)->flags = btrfs_stack_inode_flags(inode_item);
+	btrfs_inode_split_flags(btrfs_stack_inode_flags(inode_item),
+				&BTRFS_I(inode)->flags, &BTRFS_I(inode)->ro_flags);
 
 	inode->i_atime.tv_sec = btrfs_stack_timespec_sec(&inode_item->atime);
 	inode->i_atime.tv_nsec = btrfs_stack_timespec_nsec(&inode_item->atime);
diff --git a/fs/btrfs/dir-item.c b/fs/btrfs/dir-item.c
index 98b63ebed539..f1274d5c3805 100644
--- a/fs/btrfs/dir-item.c
+++ b/fs/btrfs/dir-item.c
@@ -170,6 +170,25 @@ out_free:
 	return 0;
 }
 
+static struct btrfs_dir_item *btrfs_lookup_match_dir(
+			struct btrfs_trans_handle *trans,
+			struct btrfs_root *root, struct btrfs_path *path,
+			struct btrfs_key *key, const char *name,
+			int name_len, int mod)
+{
+	const int ins_len = (mod < 0 ? -1 : 0);
+	const int cow = (mod != 0);
+	int ret;
+
+	ret = btrfs_search_slot(trans, root, key, path, ins_len, cow);
+	if (ret < 0)
+		return ERR_PTR(ret);
+	if (ret > 0)
+		return ERR_PTR(-ENOENT);
+
+	return btrfs_match_dir_item_name(root->fs_info, path, name, name_len);
+}
+
 /*
  * lookup a directory item based on name.  'dir' is the objectid
  * we're searching in, and 'mod' tells us if you plan on deleting the
@@ -181,23 +200,18 @@ struct btrfs_dir_item *btrfs_lookup_dir_item(struct btrfs_trans_handle *trans,
 					     const char *name, int name_len,
 					     int mod)
 {
-	int ret;
 	struct btrfs_key key;
-	int ins_len = mod < 0 ? -1 : 0;
-	int cow = mod != 0;
+	struct btrfs_dir_item *di;
 
 	key.objectid = dir;
 	key.type = BTRFS_DIR_ITEM_KEY;
-
 	key.offset = btrfs_name_hash(name, name_len);
 
-	ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
-	if (ret < 0)
-		return ERR_PTR(ret);
-	if (ret > 0)
+	di = btrfs_lookup_match_dir(trans, root, path, &key, name, name_len, mod);
+	if (IS_ERR(di) && PTR_ERR(di) == -ENOENT)
 		return NULL;
 
-	return btrfs_match_dir_item_name(root->fs_info, path, name, name_len);
+	return di;
 }
 
 int btrfs_check_dir_item_collision(struct btrfs_root *root, u64 dir,
@@ -211,7 +225,6 @@ int btrfs_check_dir_item_collision(struct btrfs_root *root, u64 dir,
 	int slot;
 	struct btrfs_path *path;
 
-
 	path = btrfs_alloc_path();
 	if (!path)
 		return -ENOMEM;
@@ -220,20 +233,20 @@ int btrfs_check_dir_item_collision(struct btrfs_root *root, u64 dir,
 	key.type = BTRFS_DIR_ITEM_KEY;
 	key.offset = btrfs_name_hash(name, name_len);
 
-	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
-
-	/* return back any errors */
-	if (ret < 0)
-		goto out;
+	di = btrfs_lookup_match_dir(NULL, root, path, &key, name, name_len, 0);
+	if (IS_ERR(di)) {
+		ret = PTR_ERR(di);
+		/* Nothing found, we're safe */
+		if (ret == -ENOENT) {
+			ret = 0;
+			goto out;
+		}
 
-	/* nothing found, we're safe */
-	if (ret > 0) {
-		ret = 0;
-		goto out;
+		if (ret < 0)
+			goto out;
 	}
 
 	/* we found an item, look for our name in the item */
-	di = btrfs_match_dir_item_name(root->fs_info, path, name, name_len);
 	if (di) {
 		/* our exact name was found */
 		ret = -EEXIST;
@@ -274,21 +287,13 @@ btrfs_lookup_dir_index_item(struct btrfs_trans_handle *trans,
 			    u64 objectid, const char *name, int name_len,
 			    int mod)
 {
-	int ret;
 	struct btrfs_key key;
-	int ins_len = mod < 0 ? -1 : 0;
-	int cow = mod != 0;
 
 	key.objectid = dir;
 	key.type = BTRFS_DIR_INDEX_KEY;
 	key.offset = objectid;
 
-	ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
-	if (ret < 0)
-		return ERR_PTR(ret);
-	if (ret > 0)
-		return ERR_PTR(-ENOENT);
-	return btrfs_match_dir_item_name(root->fs_info, path, name, name_len);
+	return btrfs_lookup_match_dir(trans, root, path, &key, name, name_len, mod);
 }
 
 struct btrfs_dir_item *
@@ -345,21 +350,18 @@ struct btrfs_dir_item *btrfs_lookup_xattr(struct btrfs_trans_handle *trans,
 					  const char *name, u16 name_len,
 					  int mod)
 {
-	int ret;
 	struct btrfs_key key;
-	int ins_len = mod < 0 ? -1 : 0;
-	int cow = mod != 0;
+	struct btrfs_dir_item *di;
 
 	key.objectid = dir;
 	key.type = BTRFS_XATTR_ITEM_KEY;
 	key.offset = btrfs_name_hash(name, name_len);
-	ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
-	if (ret < 0)
-		return ERR_PTR(ret);
-	if (ret > 0)
+
+	di = btrfs_lookup_match_dir(trans, root, path, &key, name, name_len, mod);
+	if (IS_ERR(di) && PTR_ERR(di) == -ENOENT)
 		return NULL;
 
-	return btrfs_match_dir_item_name(root->fs_info, path, name, name_len);
+	return di;
 }
 
 /*
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index a59ab7b9aea0..2f9515dccce0 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -3392,11 +3392,16 @@ int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_device
 		goto fail_alloc;
 	}
 
-	/* For 4K sector size support, it's only read-only */
-	if (PAGE_SIZE == SZ_64K && sectorsize == SZ_4K) {
-		if (!sb_rdonly(sb) || btrfs_super_log_root(disk_super)) {
+	if (sectorsize != PAGE_SIZE) {
+		btrfs_warn(fs_info,
+		"read-write for sector size %u with page size %lu is experimental",
+			   sectorsize, PAGE_SIZE);
+	}
+	if (sectorsize != PAGE_SIZE) {
+		if (btrfs_super_incompat_flags(fs_info->super_copy) &
+			BTRFS_FEATURE_INCOMPAT_RAID56) {
 			btrfs_err(fs_info,
-	"subpage sectorsize %u only supported read-only for page size %lu",
+		"RAID56 is not yet supported for sector size %u with page size %lu",
 				sectorsize, PAGE_SIZE);
 			err = -EINVAL;
 			goto fail_alloc;
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 268ce58d4569..fc3da7585fb7 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -153,7 +153,7 @@ search_again:
 	else
 		key.type = BTRFS_EXTENT_ITEM_KEY;
 
-	ret = btrfs_search_slot(trans, fs_info->extent_root, &key, path, 0, 0);
+	ret = btrfs_search_slot(NULL, fs_info->extent_root, &key, path, 0, 0);
 	if (ret < 0)
 		goto out_free;
 
@@ -5950,9 +5950,9 @@ static int btrfs_trim_free_extents(struct btrfs_device *device, u64 *trimmed)
  */
 int btrfs_trim_fs(struct btrfs_fs_info *fs_info, struct fstrim_range *range)
 {
+	struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
 	struct btrfs_block_group *cache = NULL;
 	struct btrfs_device *device;
-	struct list_head *devices;
 	u64 group_trimmed;
 	u64 range_end = U64_MAX;
 	u64 start;
@@ -6016,9 +6016,9 @@ int btrfs_trim_fs(struct btrfs_fs_info *fs_info, struct fstrim_range *range)
 		btrfs_warn(fs_info,
 			"failed to trim %llu block group(s), last error %d",
 			bg_failed, bg_ret);
-	mutex_lock(&fs_info->fs_devices->device_list_mutex);
-	devices = &fs_info->fs_devices->devices;
-	list_for_each_entry(device, devices, dev_list) {
+
+	mutex_lock(&fs_devices->device_list_mutex);
+	list_for_each_entry(device, &fs_devices->devices, dev_list) {
 		if (test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state))
 			continue;
 
@@ -6031,7 +6031,7 @@ int btrfs_trim_fs(struct btrfs_fs_info *fs_info, struct fstrim_range *range)
 
 		trimmed += group_trimmed;
 	}
-	mutex_unlock(&fs_info->fs_devices->device_list_mutex);
+	mutex_unlock(&fs_devices->device_list_mutex);
 
 	if (dev_failed)
 		btrfs_warn(fs_info,
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 9e81d25dea70..aaddd7225348 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -13,6 +13,7 @@
 #include <linux/pagevec.h>
 #include <linux/prefetch.h>
 #include <linux/cleancache.h>
+#include <linux/fsverity.h>
 #include "misc.h"
 #include "extent_io.h"
 #include "extent-io-tree.h"
@@ -172,6 +173,8 @@ int __must_check submit_one_bio(struct bio *bio, int mirror_num,
 
 	bio->bi_private = NULL;
 
+	/* Caller should ensure the bio has at least some range added */
+	ASSERT(bio->bi_iter.bi_size);
 	if (is_data_inode(tree->private_data))
 		ret = btrfs_submit_data_bio(tree->private_data, bio, mirror_num,
 					    bio_flags);
@@ -2245,18 +2248,6 @@ int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end,
 	return bitset;
 }
 
-/*
- * helper function to set a given page up to date if all the
- * extents in the tree for that page are up to date
- */
-static void check_page_uptodate(struct extent_io_tree *tree, struct page *page)
-{
-	u64 start = page_offset(page);
-	u64 end = start + PAGE_SIZE - 1;
-	if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1, NULL))
-		SetPageUptodate(page);
-}
-
 int free_io_failure(struct extent_io_tree *failure_tree,
 		    struct extent_io_tree *io_tree,
 		    struct io_failure_record *rec)
@@ -2688,7 +2679,15 @@ static void end_page_read(struct page *page, bool uptodate, u64 start, u32 len)
 	       start + len <= page_offset(page) + PAGE_SIZE);
 
 	if (uptodate) {
-		btrfs_page_set_uptodate(fs_info, page, start, len);
+		if (fsverity_active(page->mapping->host) &&
+		    !PageError(page) &&
+		    !PageUptodate(page) &&
+		    start < i_size_read(page->mapping->host) &&
+		    !fsverity_verify_page(page)) {
+			btrfs_page_set_error(fs_info, page, start, len);
+		} else {
+			btrfs_page_set_uptodate(fs_info, page, start, len);
+		}
 	} else {
 		btrfs_page_clear_uptodate(fs_info, page, start, len);
 		btrfs_page_set_error(fs_info, page, start, len);
@@ -2779,7 +2778,7 @@ next:
 void end_extent_writepage(struct page *page, int err, u64 start, u64 end)
 {
 	struct btrfs_inode *inode;
-	int uptodate = (err == 0);
+	const bool uptodate = (err == 0);
 	int ret = 0;
 
 	ASSERT(page && page->mapping);
@@ -2787,8 +2786,14 @@ void end_extent_writepage(struct page *page, int err, u64 start, u64 end)
 	btrfs_writepage_endio_finish_ordered(inode, page, start, end, uptodate);
 
 	if (!uptodate) {
-		ClearPageUptodate(page);
-		SetPageError(page);
+		const struct btrfs_fs_info *fs_info = inode->root->fs_info;
+		u32 len;
+
+		ASSERT(end + 1 - start <= U32_MAX);
+		len = end + 1 - start;
+
+		btrfs_page_clear_uptodate(fs_info, page, start, len);
+		btrfs_page_set_error(fs_info, page, start, len);
 		ret = err < 0 ? err : -EIO;
 		mapping_set_error(page->mapping, ret);
 	}
@@ -3097,7 +3102,7 @@ readpage_ok:
 		/* Update page status and unlock */
 		end_page_read(page, uptodate, start, len);
 		endio_readpage_release_extent(&processed, BTRFS_I(inode),
-					      start, end, uptodate);
+					      start, end, PageUptodate(page));
 	}
 	/* Release the last extent */
 	endio_readpage_release_extent(&processed, NULL, 0, 0, false);
@@ -3153,11 +3158,13 @@ struct bio *btrfs_io_bio_alloc(unsigned int nr_iovecs)
 	return bio;
 }
 
-struct bio *btrfs_bio_clone_partial(struct bio *orig, int offset, int size)
+struct bio *btrfs_bio_clone_partial(struct bio *orig, u64 offset, u64 size)
 {
 	struct bio *bio;
 	struct btrfs_io_bio *btrfs_bio;
 
+	ASSERT(offset <= UINT_MAX && size <= UINT_MAX);
+
 	/* this will never fail when it's backed by a bioset */
 	bio = bio_clone_fast(orig, GFP_NOFS, &btrfs_bioset);
 	ASSERT(bio);
@@ -3181,20 +3188,22 @@ struct bio *btrfs_bio_clone_partial(struct bio *orig, int offset, int size)
  * @size:	portion of page that we want to write
  * @prev_bio_flags:  flags of previous bio to see if we can merge the current one
  * @bio_flags:	flags of the current bio to see if we can merge them
- * @return:	true if page was added, false otherwise
  *
  * Attempt to add a page to bio considering stripe alignment etc.
  *
- * Return true if successfully page added. Otherwise, return false.
+ * Return >= 0 for the number of bytes added to the bio.
+ * Can return 0 if the current bio is already at stripe/zone boundary.
+ * Return <0 for error.
  */
-static bool btrfs_bio_add_page(struct btrfs_bio_ctrl *bio_ctrl,
-			       struct page *page,
-			       u64 disk_bytenr, unsigned int size,
-			       unsigned int pg_offset,
-			       unsigned long bio_flags)
+static int btrfs_bio_add_page(struct btrfs_bio_ctrl *bio_ctrl,
+			      struct page *page,
+			      u64 disk_bytenr, unsigned int size,
+			      unsigned int pg_offset,
+			      unsigned long bio_flags)
 {
 	struct bio *bio = bio_ctrl->bio;
 	u32 bio_size = bio->bi_iter.bi_size;
+	u32 real_size;
 	const sector_t sector = disk_bytenr >> SECTOR_SHIFT;
 	bool contig;
 	int ret;
@@ -3203,29 +3212,36 @@ static bool btrfs_bio_add_page(struct btrfs_bio_ctrl *bio_ctrl,
 	/* The limit should be calculated when bio_ctrl->bio is allocated */
 	ASSERT(bio_ctrl->len_to_oe_boundary && bio_ctrl->len_to_stripe_boundary);
 	if (bio_ctrl->bio_flags != bio_flags)
-		return false;
+		return 0;
 
 	if (bio_ctrl->bio_flags & EXTENT_BIO_COMPRESSED)
 		contig = bio->bi_iter.bi_sector == sector;
 	else
 		contig = bio_end_sector(bio) == sector;
 	if (!contig)
-		return false;
+		return 0;
 
-	if (bio_size + size > bio_ctrl->len_to_oe_boundary ||
-	    bio_size + size > bio_ctrl->len_to_stripe_boundary)
-		return false;
+	real_size = min(bio_ctrl->len_to_oe_boundary,
+			bio_ctrl->len_to_stripe_boundary) - bio_size;
+	real_size = min(real_size, size);
+
+	/*
+	 * If real_size is 0, never call bio_add_*_page(), as even size is 0,
+	 * bio will still execute its endio function on the page!
+	 */
+	if (real_size == 0)
+		return 0;
 
 	if (bio_op(bio) == REQ_OP_ZONE_APPEND)
-		ret = bio_add_zone_append_page(bio, page, size, pg_offset);
+		ret = bio_add_zone_append_page(bio, page, real_size, pg_offset);
 	else
-		ret = bio_add_page(bio, page, size, pg_offset);
+		ret = bio_add_page(bio, page, real_size, pg_offset);
 
-	return ret == size;
+	return ret;
 }
 
 static int calc_bio_boundaries(struct btrfs_bio_ctrl *bio_ctrl,
-			       struct btrfs_inode *inode)
+			       struct btrfs_inode *inode, u64 file_offset)
 {
 	struct btrfs_fs_info *fs_info = inode->root->fs_info;
 	struct btrfs_io_geometry geom;
@@ -3266,9 +3282,8 @@ static int calc_bio_boundaries(struct btrfs_bio_ctrl *bio_ctrl,
 		return 0;
 	}
 
-	ASSERT(fs_info->max_zone_append_size > 0);
 	/* Ordered extent not yet created, so we're good */
-	ordered = btrfs_lookup_ordered_extent(inode, logical);
+	ordered = btrfs_lookup_ordered_extent(inode, file_offset);
 	if (!ordered) {
 		bio_ctrl->len_to_oe_boundary = U32_MAX;
 		return 0;
@@ -3280,6 +3295,62 @@ static int calc_bio_boundaries(struct btrfs_bio_ctrl *bio_ctrl,
 	return 0;
 }
 
+static int alloc_new_bio(struct btrfs_inode *inode,
+			 struct btrfs_bio_ctrl *bio_ctrl,
+			 struct writeback_control *wbc,
+			 unsigned int opf,
+			 bio_end_io_t end_io_func,
+			 u64 disk_bytenr, u32 offset, u64 file_offset,
+			 unsigned long bio_flags)
+{
+	struct btrfs_fs_info *fs_info = inode->root->fs_info;
+	struct bio *bio;
+	int ret;
+
+	/*
+	 * For compressed page range, its disk_bytenr is always @disk_bytenr
+	 * passed in, no matter if we have added any range into previous bio.
+	 */
+	if (bio_flags & EXTENT_BIO_COMPRESSED)
+		bio = btrfs_bio_alloc(disk_bytenr);
+	else
+		bio = btrfs_bio_alloc(disk_bytenr + offset);
+	bio_ctrl->bio = bio;
+	bio_ctrl->bio_flags = bio_flags;
+	bio->bi_end_io = end_io_func;
+	bio->bi_private = &inode->io_tree;
+	bio->bi_write_hint = inode->vfs_inode.i_write_hint;
+	bio->bi_opf = opf;
+	ret = calc_bio_boundaries(bio_ctrl, inode, file_offset);
+	if (ret < 0)
+		goto error;
+	if (wbc) {
+		struct block_device *bdev;
+
+		bdev = fs_info->fs_devices->latest_bdev;
+		bio_set_dev(bio, bdev);
+		wbc_init_bio(wbc, bio);
+	}
+	if (btrfs_is_zoned(fs_info) && bio_op(bio) == REQ_OP_ZONE_APPEND) {
+		struct btrfs_device *device;
+
+		device = btrfs_zoned_get_device(fs_info, disk_bytenr,
+						fs_info->sectorsize);
+		if (IS_ERR(device)) {
+			ret = PTR_ERR(device);
+			goto error;
+		}
+
+		btrfs_io_bio(bio)->device = device;
+	}
+	return 0;
+error:
+	bio_ctrl->bio = NULL;
+	bio->bi_status = errno_to_blk_status(ret);
+	bio_endio(bio);
+	return ret;
+}
+
 /*
  * @opf:	bio REQ_OP_* and REQ_* flags as one value
  * @wbc:	optional writeback control for io accounting
@@ -3305,61 +3376,67 @@ static int submit_extent_page(unsigned int opf,
 			      bool force_bio_submit)
 {
 	int ret = 0;
-	struct bio *bio;
-	size_t io_size = min_t(size_t, size, PAGE_SIZE);
 	struct btrfs_inode *inode = BTRFS_I(page->mapping->host);
-	struct extent_io_tree *tree = &inode->io_tree;
-	struct btrfs_fs_info *fs_info = inode->root->fs_info;
+	unsigned int cur = pg_offset;
 
 	ASSERT(bio_ctrl);
 
 	ASSERT(pg_offset < PAGE_SIZE && size <= PAGE_SIZE &&
 	       pg_offset + size <= PAGE_SIZE);
-	if (bio_ctrl->bio) {
-		bio = bio_ctrl->bio;
-		if (force_bio_submit ||
-		    !btrfs_bio_add_page(bio_ctrl, page, disk_bytenr, io_size,
-					pg_offset, bio_flags)) {
-			ret = submit_one_bio(bio, mirror_num, bio_ctrl->bio_flags);
+	if (force_bio_submit && bio_ctrl->bio) {
+		ret = submit_one_bio(bio_ctrl->bio, mirror_num, bio_ctrl->bio_flags);
+		bio_ctrl->bio = NULL;
+		if (ret < 0)
+			return ret;
+	}
+
+	while (cur < pg_offset + size) {
+		u32 offset = cur - pg_offset;
+		int added;
+
+		/* Allocate new bio if needed */
+		if (!bio_ctrl->bio) {
+			ret = alloc_new_bio(inode, bio_ctrl, wbc, opf,
+					    end_io_func, disk_bytenr, offset,
+					    page_offset(page) + cur,
+					    bio_flags);
+			if (ret < 0)
+				return ret;
+		}
+		/*
+		 * We must go through btrfs_bio_add_page() to ensure each
+		 * page range won't cross various boundaries.
+		 */
+		if (bio_flags & EXTENT_BIO_COMPRESSED)
+			added = btrfs_bio_add_page(bio_ctrl, page, disk_bytenr,
+					size - offset, pg_offset + offset,
+					bio_flags);
+		else
+			added = btrfs_bio_add_page(bio_ctrl, page,
+					disk_bytenr + offset, size - offset,
+					pg_offset + offset, bio_flags);
+
+		/* Metadata page range should never be split */
+		if (!is_data_inode(&inode->vfs_inode))
+			ASSERT(added == 0 || added == size - offset);
+
+		/* At least we added some page, update the account */
+		if (wbc && added)
+			wbc_account_cgroup_owner(wbc, page, added);
+
+		/* We have reached boundary, submit right now */
+		if (added < size - offset) {
+			/* The bio should contain some page(s) */
+			ASSERT(bio_ctrl->bio->bi_iter.bi_size);
+			ret = submit_one_bio(bio_ctrl->bio, mirror_num,
+					bio_ctrl->bio_flags);
 			bio_ctrl->bio = NULL;
 			if (ret < 0)
 				return ret;
-		} else {
-			if (wbc)
-				wbc_account_cgroup_owner(wbc, page, io_size);
-			return 0;
 		}
+		cur += added;
 	}
-
-	bio = btrfs_bio_alloc(disk_bytenr);
-	bio_add_page(bio, page, io_size, pg_offset);
-	bio->bi_end_io = end_io_func;
-	bio->bi_private = tree;
-	bio->bi_write_hint = page->mapping->host->i_write_hint;
-	bio->bi_opf = opf;
-	if (wbc) {
-		struct block_device *bdev;
-
-		bdev = fs_info->fs_devices->latest_bdev;
-		bio_set_dev(bio, bdev);
-		wbc_init_bio(wbc, bio);
-		wbc_account_cgroup_owner(wbc, page, io_size);
-	}
-	if (btrfs_is_zoned(fs_info) && bio_op(bio) == REQ_OP_ZONE_APPEND) {
-		struct btrfs_device *device;
-
-		device = btrfs_zoned_get_device(fs_info, disk_bytenr, io_size);
-		if (IS_ERR(device))
-			return PTR_ERR(device);
-
-		btrfs_io_bio(bio)->device = device;
-	}
-
-	bio_ctrl->bio = bio;
-	bio_ctrl->bio_flags = bio_flags;
-	ret = calc_bio_boundaries(bio_ctrl, inode);
-
-	return ret;
+	return 0;
 }
 
 static int attach_extent_buffer_page(struct extent_buffer *eb,
@@ -3488,7 +3565,6 @@ int btrfs_do_readpage(struct page *page, struct extent_map **em_cached,
 	size_t pg_offset = 0;
 	size_t iosize;
 	size_t blocksize = inode->i_sb->s_blocksize;
-	unsigned long this_bio_flag = 0;
 	struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
 
 	ret = set_page_extent_mapped(page);
@@ -3519,6 +3595,7 @@ int btrfs_do_readpage(struct page *page, struct extent_map **em_cached,
 	}
 	begin_page_read(fs_info, page);
 	while (cur <= end) {
+		unsigned long this_bio_flag = 0;
 		bool force_bio_submit = false;
 		u64 disk_bytenr;
 
@@ -3627,7 +3704,6 @@ int btrfs_do_readpage(struct page *page, struct extent_map **em_cached,
 		/* the get_extent function already copied into the page */
 		if (test_range_bit(tree, cur, cur_end,
 				   EXTENT_UPTODATE, 1, NULL)) {
-			check_page_uptodate(tree, page);
 			unlock_extent(tree, cur, cur + iosize - 1);
 			end_page_read(page, true, cur, iosize);
 			cur = cur + iosize;
@@ -3722,14 +3798,9 @@ static noinline_for_stack int writepage_delalloc(struct btrfs_inode *inode,
 		ret = btrfs_run_delalloc_range(inode, page, delalloc_start,
 				delalloc_end, &page_started, nr_written, wbc);
 		if (ret) {
-			SetPageError(page);
-			/*
-			 * btrfs_run_delalloc_range should return < 0 for error
-			 * but just in case, we use > 0 here meaning the IO is
-			 * started, so we don't want to return > 0 unless
-			 * things are going well.
-			 */
-			return ret < 0 ? ret : -EIO;
+			btrfs_page_set_error(inode->root->fs_info, page,
+					     page_offset(page), PAGE_SIZE);
+			return ret;
 		}
 		/*
 		 * delalloc_end is already one less than the total length, so
@@ -3829,9 +3900,8 @@ static noinline_for_stack int __extent_writepage_io(struct btrfs_inode *inode,
 				 int *nr_ret)
 {
 	struct btrfs_fs_info *fs_info = inode->root->fs_info;
-	u64 start = page_offset(page);
-	u64 end = start + PAGE_SIZE - 1;
-	u64 cur = start;
+	u64 cur = page_offset(page);
+	u64 end = cur + PAGE_SIZE - 1;
 	u64 extent_offset;
 	u64 block_start;
 	struct extent_map *em;
@@ -3841,7 +3911,7 @@ static noinline_for_stack int __extent_writepage_io(struct btrfs_inode *inode,
 	const unsigned int write_flags = wbc_to_write_flags(wbc);
 	bool compressed;
 
-	ret = btrfs_writepage_cow_fixup(page, start, end);
+	ret = btrfs_writepage_cow_fixup(page);
 	if (ret) {
 		/* Fixup worker will requeue */
 		redirty_page_for_writepage(wbc, page);
@@ -3865,7 +3935,16 @@ static noinline_for_stack int __extent_writepage_io(struct btrfs_inode *inode,
 
 		if (cur >= i_size) {
 			btrfs_writepage_endio_finish_ordered(inode, page, cur,
-							     end, 1);
+							     end, true);
+			/*
+			 * This range is beyond i_size, thus we don't need to
+			 * bother writing back.
+			 * But we still need to clear the dirty subpage bit, or
+			 * the next time the page gets dirtied, we will try to
+			 * writeback the sectors with subpage dirty bits,
+			 * causing writeback without ordered extent.
+			 */
+			btrfs_page_clear_dirty(fs_info, page, cur, end + 1 - cur);
 			break;
 		}
 
@@ -3915,7 +3994,8 @@ static noinline_for_stack int __extent_writepage_io(struct btrfs_inode *inode,
 				nr++;
 			else
 				btrfs_writepage_endio_finish_ordered(inode,
-						page, cur, cur + iosize - 1, 1);
+						page, cur, cur + iosize - 1, true);
+			btrfs_page_clear_dirty(fs_info, page, cur, iosize);
 			cur += iosize;
 			continue;
 		}
@@ -3951,6 +4031,12 @@ static noinline_for_stack int __extent_writepage_io(struct btrfs_inode *inode,
 		cur += iosize;
 		nr++;
 	}
+	/*
+	 * If we finish without problem, we should not only clear page dirty,
+	 * but also empty subpage dirty bits
+	 */
+	if (!ret)
+		btrfs_page_assert_not_dirty(fs_info, page);
 	*nr_ret = nr;
 	return ret;
 }
@@ -3981,7 +4067,8 @@ static int __extent_writepage(struct page *page, struct writeback_control *wbc,
 
 	WARN_ON(!PageLocked(page));
 
-	ClearPageError(page);
+	btrfs_page_clear_error(btrfs_sb(inode->i_sb), page,
+			       page_offset(page), PAGE_SIZE);
 
 	pg_offset = offset_in_page(i_size);
 	if (page->index > end_index ||
@@ -4022,10 +4109,39 @@ done:
 		set_page_writeback(page);
 		end_page_writeback(page);
 	}
-	if (PageError(page)) {
-		ret = ret < 0 ? ret : -EIO;
+	/*
+	 * Here we used to have a check for PageError() and then set @ret and
+	 * call end_extent_writepage().
+	 *
+	 * But in fact setting @ret here will cause different error paths
+	 * between subpage and regular sectorsize.
+	 *
+	 * For regular page size, we never submit current page, but only add
+	 * current page to current bio.
+	 * The bio submission can only happen in next page.
+	 * Thus if we hit the PageError() branch, @ret is already set to
+	 * non-zero value and will not get updated for regular sectorsize.
+	 *
+	 * But for subpage case, it's possible we submit part of current page,
+	 * thus can get PageError() set by submitted bio of the same page,
+	 * while our @ret is still 0.
+	 *
+	 * So here we unify the behavior and don't set @ret.
+	 * Error can still be properly passed to higher layer as page will
+	 * be set error, here we just don't handle the IO failure.
+	 *
+	 * NOTE: This is just a hotfix for subpage.
+	 * The root fix will be properly ending ordered extent when we hit
+	 * an error during writeback.
+	 *
+	 * But that needs a bigger refactoring, as we not only need to grab the
+	 * submitted OE, but also need to know exactly at which bytenr we hit
+	 * the error.
+	 * Currently the full page based __extent_writepage_io() is not
+	 * capable of that.
+	 */
+	if (PageError(page))
 		end_extent_writepage(page, ret, start, page_end);
-	}
 	unlock_page(page);
 	ASSERT(ret <= 0);
 	return ret;
@@ -4984,7 +5100,7 @@ int extent_write_locked_range(struct inode *inode, u64 start, u64 end,
 			ret = __extent_writepage(page, &wbc_writepages, &epd);
 		else {
 			btrfs_writepage_endio_finish_ordered(BTRFS_I(inode),
-					page, start, start + PAGE_SIZE - 1, 1);
+					page, start, start + PAGE_SIZE - 1, true);
 			unlock_page(page);
 		}
 		put_page(page);
diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index 62027f551b44..53abdc280451 100644
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -280,7 +280,7 @@ void extent_clear_unlock_delalloc(struct btrfs_inode *inode, u64 start, u64 end,
 struct bio *btrfs_bio_alloc(u64 first_byte);
 struct bio *btrfs_io_bio_alloc(unsigned int nr_iovecs);
 struct bio *btrfs_bio_clone(struct bio *bio);
-struct bio *btrfs_bio_clone_partial(struct bio *orig, int offset, int size);
+struct bio *btrfs_bio_clone_partial(struct bio *orig, u64 offset, u64 size);
 
 int repair_io_failure(struct btrfs_fs_info *fs_info, u64 ino, u64 start,
 		      u64 length, u64 logical, struct page *page,
diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index df6631eefc65..2673c6ba7a4e 100644
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -233,7 +233,6 @@ int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
 			     struct btrfs_path *path, u64 objectid,
 			     u64 offset, int mod)
 {
-	int ret;
 	struct btrfs_key file_key;
 	int ins_len = mod < 0 ? -1 : 0;
 	int cow = mod != 0;
@@ -241,8 +240,8 @@ int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
 	file_key.objectid = objectid;
 	file_key.offset = offset;
 	file_key.type = BTRFS_EXTENT_DATA_KEY;
-	ret = btrfs_search_slot(trans, root, &file_key, path, ins_len, cow);
-	return ret;
+
+	return btrfs_search_slot(trans, root, &file_key, path, ins_len, cow);
 }
 
 /*
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index ee34497500e1..7ff577005d0f 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -16,6 +16,7 @@
 #include <linux/btrfs.h>
 #include <linux/uio.h>
 #include <linux/iversion.h>
+#include <linux/fsverity.h>
 #include "ctree.h"
 #include "disk-io.h"
 #include "transaction.h"
@@ -1340,7 +1341,18 @@ static int prepare_uptodate_page(struct inode *inode,
 			unlock_page(page);
 			return -EIO;
 		}
-		if (page->mapping != inode->i_mapping) {
+
+		/*
+		 * Since btrfs_readpage() will unlock the page before it
+		 * returns, there is a window where btrfs_releasepage() can be
+		 * called to release the page.  Here we check both inode
+		 * mapping and PagePrivate() to make sure the page was not
+		 * released.
+		 *
+		 * The private flag check is essential for subpage as we need
+		 * to store extra bitmap using page->private.
+		 */
+		if (page->mapping != inode->i_mapping || !PagePrivate(page)) {
 			unlock_page(page);
 			return -EAGAIN;
 		}
@@ -3604,7 +3616,13 @@ static loff_t btrfs_file_llseek(struct file *file, loff_t offset, int whence)
 
 static int btrfs_file_open(struct inode *inode, struct file *filp)
 {
+	int ret;
+
 	filp->f_mode |= FMODE_NOWAIT | FMODE_BUF_RASYNC;
+
+	ret = fsverity_file_open(inode, filp);
+	if (ret)
+		return ret;
 	return generic_file_open(inode, filp);
 }
 
@@ -3633,6 +3651,9 @@ static ssize_t btrfs_direct_read(struct kiocb *iocb, struct iov_iter *to)
 	struct inode *inode = file_inode(iocb->ki_filp);
 	ssize_t ret;
 
+	if (fsverity_active(inode))
+		return 0;
+
 	if (check_direct_read(btrfs_sb(inode->i_sb), to, iocb->ki_pos))
 		return 0;
 
diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index 2131ae5b9ed7..da0eee7c9e5f 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -344,19 +344,13 @@ fail:
 
 static void readahead_cache(struct inode *inode)
 {
-	struct file_ra_state *ra;
+	struct file_ra_state ra;
 	unsigned long last_index;
 
-	ra = kzalloc(sizeof(*ra), GFP_NOFS);
-	if (!ra)
-		return;
-
-	file_ra_state_init(ra, inode->i_mapping);
+	file_ra_state_init(&ra, inode->i_mapping);
 	last_index = (i_size_read(inode) - 1) >> PAGE_SHIFT;
 
-	page_cache_sync_readahead(inode->i_mapping, ra, NULL, 0, last_index);
-
-	kfree(ra);
+	page_cache_sync_readahead(inode->i_mapping, &ra, NULL, 0, last_index);
 }
 
 static int io_ctl_init(struct btrfs_io_ctl *io_ctl, struct inode *inode,
@@ -2544,6 +2538,7 @@ static int __btrfs_add_free_space_zoned(struct btrfs_block_group *block_group,
 	struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
 	u64 offset = bytenr - block_group->start;
 	u64 to_free, to_unusable;
+	const int bg_reclaim_threshold = READ_ONCE(fs_info->bg_reclaim_threshold);
 
 	spin_lock(&ctl->tree_lock);
 	if (!used)
@@ -2573,9 +2568,9 @@ static int __btrfs_add_free_space_zoned(struct btrfs_block_group *block_group,
 	/* All the region is now unusable. Mark it as unused and reclaim */
 	if (block_group->zone_unusable == block_group->length) {
 		btrfs_mark_bg_unused(block_group);
-	} else if (block_group->zone_unusable >=
-		   div_factor_fine(block_group->length,
-				   fs_info->bg_reclaim_threshold)) {
+	} else if (bg_reclaim_threshold &&
+		   block_group->zone_unusable >=
+		   div_factor_fine(block_group->length, bg_reclaim_threshold)) {
 		btrfs_mark_bg_to_reclaim(block_group);
 	}
 
@@ -2652,8 +2647,11 @@ int btrfs_remove_free_space(struct btrfs_block_group *block_group,
 		 * btrfs_pin_extent_for_log_replay() when replaying the log.
 		 * Advance the pointer not to overwrite the tree-log nodes.
 		 */
-		if (block_group->alloc_offset < offset + bytes)
-			block_group->alloc_offset = offset + bytes;
+		if (block_group->start + block_group->alloc_offset <
+		    offset + bytes) {
+			block_group->alloc_offset =
+				offset + bytes - block_group->start;
+		}
 		return 0;
 	}
 
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index bd5689fa290e..2b7fe98adec2 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -32,6 +32,7 @@
 #include <linux/sched/mm.h>
 #include <linux/iomap.h>
 #include <asm/unaligned.h>
+#include <linux/fsverity.h>
 #include "misc.h"
 #include "ctree.h"
 #include "disk-io.h"
@@ -286,9 +287,8 @@ static int insert_inline_extent(struct btrfs_trans_handle *trans,
 			cur_size = min_t(unsigned long, compressed_size,
 				       PAGE_SIZE);
 
-			kaddr = kmap_atomic(cpage);
+			kaddr = page_address(cpage);
 			write_extent_buffer(leaf, kaddr, ptr, cur_size);
-			kunmap_atomic(kaddr);
 
 			i++;
 			ptr += cur_size;
@@ -490,6 +490,9 @@ static noinline int add_async_extent(struct async_chunk *cow,
  */
 static inline bool inode_can_compress(struct btrfs_inode *inode)
 {
+	/* Subpage doesn't support compression yet */
+	if (inode->root->fs_info->sectorsize < PAGE_SIZE)
+		return false;
 	if (inode->flags & BTRFS_INODE_NODATACOW ||
 	    inode->flags & BTRFS_INODE_NODATASUM)
 		return false;
@@ -682,7 +685,11 @@ again:
 		}
 	}
 cont:
-	if (start == 0) {
+	/*
+	 * Check cow_file_range() for why we don't even try to create inline
+	 * extent for subpage case.
+	 */
+	if (start == 0 && fs_info->sectorsize == PAGE_SIZE) {
 		/* lets try to make an inline extent */
 		if (ret || total_in < actual_end) {
 			/* we didn't compress the entire range, try
@@ -973,7 +980,7 @@ retry:
 
 			p->mapping = inode->vfs_inode.i_mapping;
 			btrfs_writepage_endio_finish_ordered(inode, p, start,
-							     end, 0);
+							     end, false);
 
 			p->mapping = NULL;
 			extent_clear_unlock_delalloc(inode, start, end, NULL, 0,
@@ -1080,7 +1087,17 @@ static noinline int cow_file_range(struct btrfs_inode *inode,
 
 	inode_should_defrag(inode, start, end, num_bytes, SZ_64K);
 
-	if (start == 0) {
+	/*
+	 * Due to the page size limit, for subpage we can only trigger the
+	 * writeback for the dirty sectors of page, that means data writeback
+	 * is doing more writeback than what we want.
+	 *
+	 * This is especially unexpected for some call sites like fallocate,
+	 * where we only increase i_size after everything is done.
+	 * This means we can trigger inline extent even if we didn't want to.
+	 * So here we skip inline extent creation completely.
+	 */
+	if (start == 0 && fs_info->sectorsize == PAGE_SIZE) {
 		/* lets try to make an inline extent */
 		ret = cow_file_range_inline(inode, start, end, 0,
 					    BTRFS_COMPRESS_NONE, NULL);
@@ -1290,11 +1307,6 @@ static noinline void async_cow_submit(struct btrfs_work *work)
 	nr_pages = (async_chunk->end - async_chunk->start + PAGE_SIZE) >>
 		PAGE_SHIFT;
 
-	/* atomic_sub_return implies a barrier */
-	if (atomic_sub_return(nr_pages, &fs_info->async_delalloc_pages) <
-	    5 * SZ_1M)
-		cond_wake_up_nomb(&fs_info->async_submit_wait);
-
 	/*
 	 * ->inode could be NULL if async_chunk_start has failed to compress,
 	 * in which case we don't have anything to submit, yet we need to
@@ -1303,6 +1315,11 @@ static noinline void async_cow_submit(struct btrfs_work *work)
 	 */
 	if (async_chunk->inode)
 		submit_compressed_extents(async_chunk);
+
+	/* atomic_sub_return implies a barrier */
+	if (atomic_sub_return(nr_pages, &fs_info->async_delalloc_pages) <
+	    5 * SZ_1M)
+		cond_wake_up_nomb(&fs_info->async_submit_wait);
 }
 
 static noinline void async_cow_free(struct btrfs_work *work)
@@ -1946,6 +1963,7 @@ int btrfs_run_delalloc_range(struct btrfs_inode *inode, struct page *locked_page
 		ret = cow_file_range_async(inode, wbc, locked_page, start, end,
 					   page_started, nr_written);
 	}
+	ASSERT(ret <= 0);
 	if (ret)
 		btrfs_cleanup_ordered_extents(inode, locked_page, start,
 					      end - start + 1);
@@ -2285,7 +2303,6 @@ static int split_zoned_em(struct btrfs_inode *inode, u64 start, u64 len,
 	struct extent_map *split_mid = NULL;
 	struct extent_map *split_post = NULL;
 	int ret = 0;
-	int modified;
 	unsigned long flags;
 
 	/* Sanity check */
@@ -2315,11 +2332,12 @@ static int split_zoned_em(struct btrfs_inode *inode, u64 start, u64 len,
 	ASSERT(em->len == len);
 	ASSERT(!test_bit(EXTENT_FLAG_COMPRESSED, &em->flags));
 	ASSERT(em->block_start < EXTENT_MAP_LAST_BYTE);
+	ASSERT(test_bit(EXTENT_FLAG_PINNED, &em->flags));
+	ASSERT(!test_bit(EXTENT_FLAG_LOGGING, &em->flags));
+	ASSERT(!list_empty(&em->list));
 
 	flags = em->flags;
 	clear_bit(EXTENT_FLAG_PINNED, &em->flags);
-	clear_bit(EXTENT_FLAG_LOGGING, &flags);
-	modified = !list_empty(&em->list);
 
 	/* First, replace the em with a new extent_map starting from * em->start */
 	split_pre->start = em->start;
@@ -2333,7 +2351,7 @@ static int split_zoned_em(struct btrfs_inode *inode, u64 start, u64 len,
 	split_pre->compress_type = em->compress_type;
 	split_pre->generation = em->generation;
 
-	replace_extent_mapping(em_tree, em, split_pre, modified);
+	replace_extent_mapping(em_tree, em, split_pre, 1);
 
 	/*
 	 * Now we only have an extent_map at:
@@ -2353,7 +2371,7 @@ static int split_zoned_em(struct btrfs_inode *inode, u64 start, u64 len,
 		split_mid->flags = flags;
 		split_mid->compress_type = em->compress_type;
 		split_mid->generation = em->generation;
-		add_extent_mapping(em_tree, split_mid, modified);
+		add_extent_mapping(em_tree, split_mid, 1);
 	}
 
 	if (post) {
@@ -2367,7 +2385,7 @@ static int split_zoned_em(struct btrfs_inode *inode, u64 start, u64 len,
 		split_post->flags = flags;
 		split_post->compress_type = em->compress_type;
 		split_post->generation = em->generation;
-		add_extent_mapping(em_tree, split_post, modified);
+		add_extent_mapping(em_tree, split_post, 1);
 	}
 
 	/* Once for us */
@@ -2770,7 +2788,7 @@ out_page:
  * to fix it up.  The async helper will wait for ordered extents, set
  * the delalloc bit and make it safe to write the page.
  */
-int btrfs_writepage_cow_fixup(struct page *page, u64 start, u64 end)
+int btrfs_writepage_cow_fixup(struct page *page)
 {
 	struct inode *inode = page->mapping->host;
 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
@@ -3171,7 +3189,7 @@ static void finish_ordered_fn(struct btrfs_work *work)
 
 void btrfs_writepage_endio_finish_ordered(struct btrfs_inode *inode,
 					  struct page *page, u64 start,
-					  u64 end, int uptodate)
+					  u64 end, bool uptodate)
 {
 	trace_btrfs_writepage_end_io_hook(inode, start, end, uptodate);
 
@@ -3257,25 +3275,44 @@ unsigned int btrfs_verify_data_csum(struct btrfs_io_bio *io_bio, u32 bio_offset,
 		return 0;
 	}
 
-	if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
+	/*
+	 * For subpage case, above PageChecked is not safe as it's not subpage
+	 * compatible.
+	 * But for now only cow fixup and compressed read utilize PageChecked
+	 * flag, while in this context we can easily use io_bio->csum to
+	 * determine if we really need to do csum verification.
+	 *
+	 * So for now, just exit if io_bio->csum is NULL, as it means it's
+	 * compressed read, and its compressed data csum has already been
+	 * verified.
+	 */
+	if (io_bio->csum == NULL)
 		return 0;
 
-	if (!root->fs_info->csum_root)
+	if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
 		return 0;
 
-	if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID &&
-	    test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) {
-		clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM);
+	if (!root->fs_info->csum_root)
 		return 0;
-	}
 
 	ASSERT(page_offset(page) <= start &&
 	       end <= page_offset(page) + PAGE_SIZE - 1);
 	for (pg_off = offset_in_page(start);
 	     pg_off < offset_in_page(end);
 	     pg_off += sectorsize, bio_offset += sectorsize) {
+		u64 file_offset = pg_off + page_offset(page);
 		int ret;
 
+		if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID &&
+		    test_range_bit(io_tree, file_offset,
+				   file_offset + sectorsize - 1,
+				   EXTENT_NODATASUM, 1, NULL)) {
+			/* Skip the range without csum for data reloc inode */
+			clear_extent_bits(io_tree, file_offset,
+					  file_offset + sectorsize - 1,
+					  EXTENT_NODATASUM);
+			continue;
+		}
 		ret = check_data_csum(inode, io_bio, bio_offset, page, pg_off,
 				      page_offset(page) + pg_off);
 		if (ret < 0) {
@@ -3520,7 +3557,14 @@ int btrfs_orphan_cleanup(struct btrfs_root *root)
 
 		/*
 		 * If we have an inode with links, there are a couple of
-		 * possibilities. Old kernels (before v3.12) used to create an
+		 * possibilities:
+		 *
+		 * 1. We were halfway through creating fsverity metadata for the
+		 * file. In that case, the orphan item represents incomplete
+		 * fsverity metadata which must be cleaned up with
+		 * btrfs_drop_verity_items and deleting the orphan item.
+
+		 * 2. Old kernels (before v3.12) used to create an
 		 * orphan item for truncate indicating that there were possibly
 		 * extent items past i_size that needed to be deleted. In v3.12,
 		 * truncate was changed to update i_size in sync with the extent
@@ -3538,8 +3582,12 @@ int btrfs_orphan_cleanup(struct btrfs_root *root)
 		 * but either way, we can delete the orphan item.
 		 */
 		if (ret == -ENOENT || inode->i_nlink) {
-			if (!ret)
+			if (!ret) {
+				ret = btrfs_drop_verity_items(BTRFS_I(inode));
 				iput(inode);
+				if (ret)
+					goto out;
+			}
 			trans = btrfs_start_transaction(root, 1);
 			if (IS_ERR(trans)) {
 				ret = PTR_ERR(trans);
@@ -3728,7 +3776,8 @@ static int btrfs_read_locked_inode(struct inode *inode,
 	rdev = btrfs_inode_rdev(leaf, inode_item);
 
 	BTRFS_I(inode)->index_cnt = (u64)-1;
-	BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
+	btrfs_inode_split_flags(btrfs_inode_flags(leaf, inode_item),
+				&BTRFS_I(inode)->flags, &BTRFS_I(inode)->ro_flags);
 
 cache_index:
 	/*
@@ -3859,6 +3908,7 @@ static void fill_inode_item(struct btrfs_trans_handle *trans,
 			    struct inode *inode)
 {
 	struct btrfs_map_token token;
+	u64 flags;
 
 	btrfs_init_map_token(&token, leaf);
 
@@ -3894,7 +3944,9 @@ static void fill_inode_item(struct btrfs_trans_handle *trans,
 	btrfs_set_token_inode_sequence(&token, item, inode_peek_iversion(inode));
 	btrfs_set_token_inode_transid(&token, item, trans->transid);
 	btrfs_set_token_inode_rdev(&token, item, inode->i_rdev);
-	btrfs_set_token_inode_flags(&token, item, BTRFS_I(inode)->flags);
+	flags = btrfs_inode_combine_flags(BTRFS_I(inode)->flags,
+					  BTRFS_I(inode)->ro_flags);
+	btrfs_set_token_inode_flags(&token, item, flags);
 	btrfs_set_token_inode_block_group(&token, item, 0);
 }
 
@@ -5088,15 +5140,13 @@ static int maybe_insert_hole(struct btrfs_root *root, struct btrfs_inode *inode,
 	int ret;
 
 	/*
-	 * Still need to make sure the inode looks like it's been updated so
-	 * that any holes get logged if we fsync.
+	 * If NO_HOLES is enabled, we don't need to do anything.
+	 * Later, up in the call chain, either btrfs_set_inode_last_sub_trans()
+	 * or btrfs_update_inode() will be called, which guarantee that the next
+	 * fsync will know this inode was changed and needs to be logged.
 	 */
-	if (btrfs_fs_incompat(fs_info, NO_HOLES)) {
-		inode->last_trans = fs_info->generation;
-		inode->last_sub_trans = root->log_transid;
-		inode->last_log_commit = root->last_log_commit;
+	if (btrfs_fs_incompat(fs_info, NO_HOLES))
 		return 0;
-	}
 
 	/*
 	 * 1 - for the one we're dropping
@@ -5342,7 +5392,7 @@ static int btrfs_setattr(struct user_namespace *mnt_userns, struct dentry *dentr
 	if (btrfs_root_readonly(root))
 		return -EROFS;
 
-	err = setattr_prepare(&init_user_ns, dentry, attr);
+	err = setattr_prepare(mnt_userns, dentry, attr);
 	if (err)
 		return err;
 
@@ -5353,13 +5403,12 @@ static int btrfs_setattr(struct user_namespace *mnt_userns, struct dentry *dentr
 	}
 
 	if (attr->ia_valid) {
-		setattr_copy(&init_user_ns, inode, attr);
+		setattr_copy(mnt_userns, inode, attr);
 		inode_inc_iversion(inode);
 		err = btrfs_dirty_inode(inode);
 
 		if (!err && attr->ia_valid & ATTR_MODE)
-			err = posix_acl_chmod(&init_user_ns, inode,
-					      inode->i_mode);
+			err = posix_acl_chmod(mnt_userns, inode, inode->i_mode);
 	}
 
 	return err;
@@ -5522,6 +5571,7 @@ void btrfs_evict_inode(struct inode *inode)
 	trace_btrfs_inode_evict(inode);
 
 	if (!root) {
+		fsverity_cleanup_inode(inode);
 		clear_inode(inode);
 		return;
 	}
@@ -5604,6 +5654,7 @@ no_delete:
 	 * to retry these periodically in the future.
 	 */
 	btrfs_remove_delayed_node(BTRFS_I(inode));
+	fsverity_cleanup_inode(inode);
 	clear_inode(inode);
 }
 
@@ -6370,6 +6421,7 @@ static void btrfs_inherit_iflags(struct inode *inode, struct inode *dir)
 
 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
 				     struct btrfs_root *root,
+				     struct user_namespace *mnt_userns,
 				     struct inode *dir,
 				     const char *name, int name_len,
 				     u64 ref_objectid, u64 objectid,
@@ -6479,7 +6531,7 @@ static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
 	if (ret != 0)
 		goto fail_unlock;
 
-	inode_init_owner(&init_user_ns, inode, dir, mode);
+	inode_init_owner(mnt_userns, inode, dir, mode);
 	inode_set_bytes(inode, 0);
 
 	inode->i_mtime = current_time(inode);
@@ -6664,9 +6716,9 @@ static int btrfs_mknod(struct user_namespace *mnt_userns, struct inode *dir,
 	if (err)
 		goto out_unlock;
 
-	inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
-			dentry->d_name.len, btrfs_ino(BTRFS_I(dir)), objectid,
-			mode, &index);
+	inode = btrfs_new_inode(trans, root, mnt_userns, dir,
+			dentry->d_name.name, dentry->d_name.len,
+			btrfs_ino(BTRFS_I(dir)), objectid, mode, &index);
 	if (IS_ERR(inode)) {
 		err = PTR_ERR(inode);
 		inode = NULL;
@@ -6728,9 +6780,9 @@ static int btrfs_create(struct user_namespace *mnt_userns, struct inode *dir,
 	if (err)
 		goto out_unlock;
 
-	inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
-			dentry->d_name.len, btrfs_ino(BTRFS_I(dir)), objectid,
-			mode, &index);
+	inode = btrfs_new_inode(trans, root, mnt_userns, dir,
+			dentry->d_name.name, dentry->d_name.len,
+			btrfs_ino(BTRFS_I(dir)), objectid, mode, &index);
 	if (IS_ERR(inode)) {
 		err = PTR_ERR(inode);
 		inode = NULL;
@@ -6873,8 +6925,9 @@ static int btrfs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
 	if (err)
 		goto out_fail;
 
-	inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
-			dentry->d_name.len, btrfs_ino(BTRFS_I(dir)), objectid,
+	inode = btrfs_new_inode(trans, root, mnt_userns, dir,
+			dentry->d_name.name, dentry->d_name.len,
+			btrfs_ino(BTRFS_I(dir)), objectid,
 			S_IFDIR | mode, &index);
 	if (IS_ERR(inode)) {
 		err = PTR_ERR(inode);
@@ -8206,8 +8259,8 @@ static blk_qc_t btrfs_submit_direct(struct inode *inode, struct iomap *iomap,
 	u64 start_sector;
 	int async_submit = 0;
 	u64 submit_len;
-	int clone_offset = 0;
-	int clone_len;
+	u64 clone_offset = 0;
+	u64 clone_len;
 	u64 logical;
 	int ret;
 	blk_status_t status;
@@ -8255,9 +8308,9 @@ static blk_qc_t btrfs_submit_direct(struct inode *inode, struct iomap *iomap,
 			status = errno_to_blk_status(ret);
 			goto out_err_em;
 		}
-		ASSERT(geom.len <= INT_MAX);
 
-		clone_len = min_t(int, submit_len, geom.len);
+		clone_len = min(submit_len, geom.len);
+		ASSERT(clone_len <= UINT_MAX);
 
 		/*
 		 * This will never fail as it's passing GPF_NOFS and
@@ -8401,11 +8454,47 @@ static void btrfs_readahead(struct readahead_control *rac)
 	extent_readahead(rac);
 }
 
+/*
+ * For releasepage() and invalidatepage() we have a race window where
+ * end_page_writeback() is called but the subpage spinlock is not yet released.
+ * If we continue to release/invalidate the page, we could cause use-after-free
+ * for subpage spinlock.  So this function is to spin and wait for subpage
+ * spinlock.
+ */
+static void wait_subpage_spinlock(struct page *page)
+{
+	struct btrfs_fs_info *fs_info = btrfs_sb(page->mapping->host->i_sb);
+	struct btrfs_subpage *subpage;
+
+	if (fs_info->sectorsize == PAGE_SIZE)
+		return;
+
+	ASSERT(PagePrivate(page) && page->private);
+	subpage = (struct btrfs_subpage *)page->private;
+
+	/*
+	 * This may look insane as we just acquire the spinlock and release it,
+	 * without doing anything.  But we just want to make sure no one is
+	 * still holding the subpage spinlock.
+	 * And since the page is not dirty nor writeback, and we have page
+	 * locked, the only possible way to hold a spinlock is from the endio
+	 * function to clear page writeback.
+	 *
+	 * Here we just acquire the spinlock so that all existing callers
+	 * should exit and we're safe to release/invalidate the page.
+	 */
+	spin_lock_irq(&subpage->lock);
+	spin_unlock_irq(&subpage->lock);
+}
+
 static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
 {
 	int ret = try_release_extent_mapping(page, gfp_flags);
-	if (ret == 1)
+
+	if (ret == 1) {
+		wait_subpage_spinlock(page);
 		clear_page_extent_mapped(page);
+	}
 	return ret;
 }
 
@@ -8469,6 +8558,7 @@ static void btrfs_invalidatepage(struct page *page, unsigned int offset,
 	 * do double ordered extent accounting on the same page.
 	 */
 	wait_on_page_writeback(page);
+	wait_subpage_spinlock(page);
 
 	/*
 	 * For subpage case, we have call sites like
@@ -8557,7 +8647,7 @@ static void btrfs_invalidatepage(struct page *page, unsigned int offset,
 		spin_unlock_irq(&inode->ordered_tree.lock);
 
 		if (btrfs_dec_test_ordered_pending(inode, &ordered,
-					cur, range_end + 1 - cur, 1)) {
+						   cur, range_end + 1 - cur)) {
 			btrfs_finish_ordered_io(ordered);
 			/*
 			 * The ordered extent has finished, now we're again
@@ -8938,7 +9028,8 @@ out:
  */
 int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
 			     struct btrfs_root *new_root,
-			     struct btrfs_root *parent_root)
+			     struct btrfs_root *parent_root,
+			     struct user_namespace *mnt_userns)
 {
 	struct inode *inode;
 	int err;
@@ -8949,7 +9040,8 @@ int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
 	if (err < 0)
 		return err;
 
-	inode = btrfs_new_inode(trans, new_root, NULL, "..", 2, ino, ino,
+	inode = btrfs_new_inode(trans, new_root, mnt_userns, NULL, "..", 2,
+				ino, ino,
 				S_IFDIR | (~current_umask() & S_IRWXUGO),
 				&index);
 	if (IS_ERR(inode))
@@ -8993,6 +9085,7 @@ struct inode *btrfs_alloc_inode(struct super_block *sb)
 	ei->defrag_bytes = 0;
 	ei->disk_i_size = 0;
 	ei->flags = 0;
+	ei->ro_flags = 0;
 	ei->csum_bytes = 0;
 	ei->index_cnt = (u64)-1;
 	ei->dir_index = 0;
@@ -9174,6 +9267,7 @@ static int btrfs_getattr(struct user_namespace *mnt_userns,
 	struct inode *inode = d_inode(path->dentry);
 	u32 blocksize = inode->i_sb->s_blocksize;
 	u32 bi_flags = BTRFS_I(inode)->flags;
+	u32 bi_ro_flags = BTRFS_I(inode)->ro_flags;
 
 	stat->result_mask |= STATX_BTIME;
 	stat->btime.tv_sec = BTRFS_I(inode)->i_otime.tv_sec;
@@ -9186,13 +9280,15 @@ static int btrfs_getattr(struct user_namespace *mnt_userns,
 		stat->attributes |= STATX_ATTR_IMMUTABLE;
 	if (bi_flags & BTRFS_INODE_NODUMP)
 		stat->attributes |= STATX_ATTR_NODUMP;
+	if (bi_ro_flags & BTRFS_INODE_RO_VERITY)
+		stat->attributes |= STATX_ATTR_VERITY;
 
 	stat->attributes_mask |= (STATX_ATTR_APPEND |
 				  STATX_ATTR_COMPRESSED |
 				  STATX_ATTR_IMMUTABLE |
 				  STATX_ATTR_NODUMP);
 
-	generic_fillattr(&init_user_ns, inode, stat);
+	generic_fillattr(mnt_userns, inode, stat);
 	stat->dev = BTRFS_I(inode)->root->anon_dev;
 
 	spin_lock(&BTRFS_I(inode)->lock);
@@ -9280,8 +9376,6 @@ static int btrfs_rename_exchange(struct inode *old_dir,
 		/* force full log commit if subvolume involved. */
 		btrfs_set_log_full_commit(trans);
 	} else {
-		btrfs_pin_log_trans(root);
-		root_log_pinned = true;
 		ret = btrfs_insert_inode_ref(trans, dest,
 					     new_dentry->d_name.name,
 					     new_dentry->d_name.len,
@@ -9298,8 +9392,6 @@ static int btrfs_rename_exchange(struct inode *old_dir,
 		/* force full log commit if subvolume involved. */
 		btrfs_set_log_full_commit(trans);
 	} else {
-		btrfs_pin_log_trans(dest);
-		dest_log_pinned = true;
 		ret = btrfs_insert_inode_ref(trans, root,
 					     old_dentry->d_name.name,
 					     old_dentry->d_name.len,
@@ -9330,6 +9422,29 @@ static int btrfs_rename_exchange(struct inode *old_dir,
 				BTRFS_I(new_inode), 1);
 	}
 
+	/*
+	 * Now pin the logs of the roots. We do it to ensure that no other task
+	 * can sync the logs while we are in progress with the rename, because
+	 * that could result in an inconsistency in case any of the inodes that
+	 * are part of this rename operation were logged before.
+	 *
+	 * We pin the logs even if at this precise moment none of the inodes was
+	 * logged before. This is because right after we checked for that, some
+	 * other task fsyncing some other inode not involved with this rename
+	 * operation could log that one of our inodes exists.
+	 *
+	 * We don't need to pin the logs before the above calls to
+	 * btrfs_insert_inode_ref(), since those don't ever need to change a log.
+	 */
+	if (old_ino != BTRFS_FIRST_FREE_OBJECTID) {
+		btrfs_pin_log_trans(root);
+		root_log_pinned = true;
+	}
+	if (new_ino != BTRFS_FIRST_FREE_OBJECTID) {
+		btrfs_pin_log_trans(dest);
+		dest_log_pinned = true;
+	}
+
 	/* src is a subvolume */
 	if (old_ino == BTRFS_FIRST_FREE_OBJECTID) {
 		ret = btrfs_unlink_subvol(trans, old_dir, old_dentry);
@@ -9411,8 +9526,7 @@ out_fail:
 		if (btrfs_inode_in_log(BTRFS_I(old_dir), fs_info->generation) ||
 		    btrfs_inode_in_log(BTRFS_I(new_dir), fs_info->generation) ||
 		    btrfs_inode_in_log(BTRFS_I(old_inode), fs_info->generation) ||
-		    (new_inode &&
-		     btrfs_inode_in_log(BTRFS_I(new_inode), fs_info->generation)))
+		    btrfs_inode_in_log(BTRFS_I(new_inode), fs_info->generation))
 			btrfs_set_log_full_commit(trans);
 
 		if (root_log_pinned) {
@@ -9436,6 +9550,7 @@ out_notrans:
 
 static int btrfs_whiteout_for_rename(struct btrfs_trans_handle *trans,
 				     struct btrfs_root *root,
+				     struct user_namespace *mnt_userns,
 				     struct inode *dir,
 				     struct dentry *dentry)
 {
@@ -9448,7 +9563,7 @@ static int btrfs_whiteout_for_rename(struct btrfs_trans_handle *trans,
 	if (ret)
 		return ret;
 
-	inode = btrfs_new_inode(trans, root, dir,
+	inode = btrfs_new_inode(trans, root, mnt_userns, dir,
 				dentry->d_name.name,
 				dentry->d_name.len,
 				btrfs_ino(BTRFS_I(dir)),
@@ -9485,9 +9600,10 @@ out:
 	return ret;
 }
 
-static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
-			   struct inode *new_dir, struct dentry *new_dentry,
-			   unsigned int flags)
+static int btrfs_rename(struct user_namespace *mnt_userns,
+			struct inode *old_dir, struct dentry *old_dentry,
+			struct inode *new_dir, struct dentry *new_dentry,
+			unsigned int flags)
 {
 	struct btrfs_fs_info *fs_info = btrfs_sb(old_dir->i_sb);
 	struct btrfs_trans_handle *trans;
@@ -9582,8 +9698,6 @@ static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 		/* force full log commit if subvolume involved. */
 		btrfs_set_log_full_commit(trans);
 	} else {
-		btrfs_pin_log_trans(root);
-		log_pinned = true;
 		ret = btrfs_insert_inode_ref(trans, dest,
 					     new_dentry->d_name.name,
 					     new_dentry->d_name.len,
@@ -9607,6 +9721,25 @@ static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 	if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
 		ret = btrfs_unlink_subvol(trans, old_dir, old_dentry);
 	} else {
+		/*
+		 * Now pin the log. We do it to ensure that no other task can
+		 * sync the log while we are in progress with the rename, as
+		 * that could result in an inconsistency in case any of the
+		 * inodes that are part of this rename operation were logged
+		 * before.
+		 *
+		 * We pin the log even if at this precise moment none of the
+		 * inodes was logged before. This is because right after we
+		 * checked for that, some other task fsyncing some other inode
+		 * not involved with this rename operation could log that one of
+		 * our inodes exists.
+		 *
+		 * We don't need to pin the logs before the above call to
+		 * btrfs_insert_inode_ref(), since that does not need to change
+		 * a log.
+		 */
+		btrfs_pin_log_trans(root);
+		log_pinned = true;
 		ret = __btrfs_unlink_inode(trans, root, BTRFS_I(old_dir),
 					BTRFS_I(d_inode(old_dentry)),
 					old_dentry->d_name.name,
@@ -9660,8 +9793,8 @@ static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 	}
 
 	if (flags & RENAME_WHITEOUT) {
-		ret = btrfs_whiteout_for_rename(trans, root, old_dir,
-						old_dentry);
+		ret = btrfs_whiteout_for_rename(trans, root, mnt_userns,
+						old_dir, old_dentry);
 
 		if (ret) {
 			btrfs_abort_transaction(trans, ret);
@@ -9711,7 +9844,8 @@ static int btrfs_rename2(struct user_namespace *mnt_userns, struct inode *old_di
 		return btrfs_rename_exchange(old_dir, old_dentry, new_dir,
 					  new_dentry);
 
-	return btrfs_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
+	return btrfs_rename(mnt_userns, old_dir, old_dentry, new_dir,
+			    new_dentry, flags);
 }
 
 struct btrfs_delalloc_work {
@@ -9808,11 +9942,7 @@ static int start_delalloc_inodes(struct btrfs_root *root,
 			btrfs_queue_work(root->fs_info->flush_workers,
 					 &work->work);
 		} else {
-			ret = sync_inode(inode, wbc);
-			if (!ret &&
-			    test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
-				     &BTRFS_I(inode)->runtime_flags))
-				ret = sync_inode(inode, wbc);
+			ret = filemap_fdatawrite_wbc(inode->i_mapping, wbc);
 			btrfs_add_delayed_iput(inode);
 			if (ret || wbc->nr_to_write <= 0)
 				goto out;
@@ -9947,9 +10077,10 @@ static int btrfs_symlink(struct user_namespace *mnt_userns, struct inode *dir,
 	if (err)
 		goto out_unlock;
 
-	inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
-				dentry->d_name.len, btrfs_ino(BTRFS_I(dir)),
-				objectid, S_IFLNK|S_IRWXUGO, &index);
+	inode = btrfs_new_inode(trans, root, mnt_userns, dir,
+				dentry->d_name.name, dentry->d_name.len,
+				btrfs_ino(BTRFS_I(dir)), objectid,
+				S_IFLNK | S_IRWXUGO, &index);
 	if (IS_ERR(inode)) {
 		err = PTR_ERR(inode);
 		inode = NULL;
@@ -10273,7 +10404,7 @@ static int btrfs_permission(struct user_namespace *mnt_userns,
 		if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY)
 			return -EACCES;
 	}
-	return generic_permission(&init_user_ns, inode, mask);
+	return generic_permission(mnt_userns, inode, mask);
 }
 
 static int btrfs_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
@@ -10298,7 +10429,7 @@ static int btrfs_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
 	if (ret)
 		goto out;
 
-	inode = btrfs_new_inode(trans, root, dir, NULL, 0,
+	inode = btrfs_new_inode(trans, root, mnt_userns, dir, NULL, 0,
 			btrfs_ino(BTRFS_I(dir)), objectid, mode, &index);
 	if (IS_ERR(inode)) {
 		ret = PTR_ERR(inode);
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 0ba98e08a029..41524f9aeac3 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -27,6 +27,7 @@
 #include <linux/uaccess.h>
 #include <linux/iversion.h>
 #include <linux/fileattr.h>
+#include <linux/fsverity.h>
 #include "ctree.h"
 #include "disk-io.h"
 #include "export.h"
@@ -103,9 +104,11 @@ static unsigned int btrfs_mask_fsflags_for_type(struct inode *inode,
  * Export internal inode flags to the format expected by the FS_IOC_GETFLAGS
  * ioctl.
  */
-static unsigned int btrfs_inode_flags_to_fsflags(unsigned int flags)
+static unsigned int btrfs_inode_flags_to_fsflags(struct btrfs_inode *binode)
 {
 	unsigned int iflags = 0;
+	u32 flags = binode->flags;
+	u32 ro_flags = binode->ro_flags;
 
 	if (flags & BTRFS_INODE_SYNC)
 		iflags |= FS_SYNC_FL;
@@ -121,6 +124,8 @@ static unsigned int btrfs_inode_flags_to_fsflags(unsigned int flags)
 		iflags |= FS_DIRSYNC_FL;
 	if (flags & BTRFS_INODE_NODATACOW)
 		iflags |= FS_NOCOW_FL;
+	if (ro_flags & BTRFS_INODE_RO_VERITY)
+		iflags |= FS_VERITY_FL;
 
 	if (flags & BTRFS_INODE_NOCOMPRESS)
 		iflags |= FS_NOCOMP_FL;
@@ -148,10 +153,12 @@ void btrfs_sync_inode_flags_to_i_flags(struct inode *inode)
 		new_fl |= S_NOATIME;
 	if (binode->flags & BTRFS_INODE_DIRSYNC)
 		new_fl |= S_DIRSYNC;
+	if (binode->ro_flags & BTRFS_INODE_RO_VERITY)
+		new_fl |= S_VERITY;
 
 	set_mask_bits(&inode->i_flags,
-		      S_SYNC | S_APPEND | S_IMMUTABLE | S_NOATIME | S_DIRSYNC,
-		      new_fl);
+		      S_SYNC | S_APPEND | S_IMMUTABLE | S_NOATIME | S_DIRSYNC |
+		      S_VERITY, new_fl);
 }
 
 /*
@@ -200,7 +207,7 @@ int btrfs_fileattr_get(struct dentry *dentry, struct fileattr *fa)
 {
 	struct btrfs_inode *binode = BTRFS_I(d_inode(dentry));
 
-	fileattr_fill_flags(fa, btrfs_inode_flags_to_fsflags(binode->flags));
+	fileattr_fill_flags(fa, btrfs_inode_flags_to_fsflags(binode));
 	return 0;
 }
 
@@ -224,7 +231,7 @@ int btrfs_fileattr_set(struct user_namespace *mnt_userns,
 		return -EOPNOTSUPP;
 
 	fsflags = btrfs_mask_fsflags_for_type(inode, fa->flags);
-	old_fsflags = btrfs_inode_flags_to_fsflags(binode->flags);
+	old_fsflags = btrfs_inode_flags_to_fsflags(binode);
 	ret = check_fsflags(old_fsflags, fsflags);
 	if (ret)
 		return ret;
@@ -492,8 +499,8 @@ int __pure btrfs_is_empty_uuid(u8 *uuid)
 	return 1;
 }
 
-static noinline int create_subvol(struct inode *dir,
-				  struct dentry *dentry,
+static noinline int create_subvol(struct user_namespace *mnt_userns,
+				  struct inode *dir, struct dentry *dentry,
 				  const char *name, int namelen,
 				  struct btrfs_qgroup_inherit *inherit)
 {
@@ -638,7 +645,7 @@ static noinline int create_subvol(struct inode *dir,
 		goto fail;
 	}
 
-	ret = btrfs_create_subvol_root(trans, new_root, root);
+	ret = btrfs_create_subvol_root(trans, new_root, root, mnt_userns);
 	btrfs_put_root(new_root);
 	if (ret) {
 		/* We potentially lose an unused inode item here */
@@ -830,7 +837,8 @@ free_pending:
  *     nfs_async_unlink().
  */
 
-static int btrfs_may_delete(struct inode *dir, struct dentry *victim, int isdir)
+static int btrfs_may_delete(struct user_namespace *mnt_userns,
+			    struct inode *dir, struct dentry *victim, int isdir)
 {
 	int error;
 
@@ -840,12 +848,12 @@ static int btrfs_may_delete(struct inode *dir, struct dentry *victim, int isdir)
 	BUG_ON(d_inode(victim->d_parent) != dir);
 	audit_inode_child(dir, victim, AUDIT_TYPE_CHILD_DELETE);
 
-	error = inode_permission(&init_user_ns, dir, MAY_WRITE | MAY_EXEC);
+	error = inode_permission(mnt_userns, dir, MAY_WRITE | MAY_EXEC);
 	if (error)
 		return error;
 	if (IS_APPEND(dir))
 		return -EPERM;
-	if (check_sticky(&init_user_ns, dir, d_inode(victim)) ||
+	if (check_sticky(mnt_userns, dir, d_inode(victim)) ||
 	    IS_APPEND(d_inode(victim)) || IS_IMMUTABLE(d_inode(victim)) ||
 	    IS_SWAPFILE(d_inode(victim)))
 		return -EPERM;
@@ -864,13 +872,16 @@ static int btrfs_may_delete(struct inode *dir, struct dentry *victim, int isdir)
 }
 
 /* copy of may_create in fs/namei.c() */
-static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
+static inline int btrfs_may_create(struct user_namespace *mnt_userns,
+				   struct inode *dir, struct dentry *child)
 {
 	if (d_really_is_positive(child))
 		return -EEXIST;
 	if (IS_DEADDIR(dir))
 		return -ENOENT;
-	return inode_permission(&init_user_ns, dir, MAY_WRITE | MAY_EXEC);
+	if (!fsuidgid_has_mapping(dir->i_sb, mnt_userns))
+		return -EOVERFLOW;
+	return inode_permission(mnt_userns, dir, MAY_WRITE | MAY_EXEC);
 }
 
 /*
@@ -879,6 +890,7 @@ static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
  * inside this filesystem so it's quite a bit simpler.
  */
 static noinline int btrfs_mksubvol(const struct path *parent,
+				   struct user_namespace *mnt_userns,
 				   const char *name, int namelen,
 				   struct btrfs_root *snap_src,
 				   bool readonly,
@@ -893,12 +905,12 @@ static noinline int btrfs_mksubvol(const struct path *parent,
 	if (error == -EINTR)
 		return error;
 
-	dentry = lookup_one_len(name, parent->dentry, namelen);
+	dentry = lookup_one(mnt_userns, name, parent->dentry, namelen);
 	error = PTR_ERR(dentry);
 	if (IS_ERR(dentry))
 		goto out_unlock;
 
-	error = btrfs_may_create(dir, dentry);
+	error = btrfs_may_create(mnt_userns, dir, dentry);
 	if (error)
 		goto out_dput;
 
@@ -920,7 +932,7 @@ static noinline int btrfs_mksubvol(const struct path *parent,
 	if (snap_src)
 		error = create_snapshot(snap_src, dir, dentry, readonly, inherit);
 	else
-		error = create_subvol(dir, dentry, name, namelen, inherit);
+		error = create_subvol(mnt_userns, dir, dentry, name, namelen, inherit);
 
 	if (!error)
 		fsnotify_mkdir(dir, dentry);
@@ -934,6 +946,7 @@ out_unlock:
 }
 
 static noinline int btrfs_mksnapshot(const struct path *parent,
+				   struct user_namespace *mnt_userns,
 				   const char *name, int namelen,
 				   struct btrfs_root *root,
 				   bool readonly,
@@ -963,7 +976,7 @@ static noinline int btrfs_mksnapshot(const struct path *parent,
 
 	btrfs_wait_ordered_extents(root, U64_MAX, 0, (u64)-1);
 
-	ret = btrfs_mksubvol(parent, name, namelen,
+	ret = btrfs_mksubvol(parent, mnt_userns, name, namelen,
 			     root, readonly, inherit);
 out:
 	if (snapshot_force_cow)
@@ -1792,6 +1805,7 @@ out_drop:
 }
 
 static noinline int __btrfs_ioctl_snap_create(struct file *file,
+				struct user_namespace *mnt_userns,
 				const char *name, unsigned long fd, int subvol,
 				bool readonly,
 				struct btrfs_qgroup_inherit *inherit)
@@ -1819,8 +1833,8 @@ static noinline int __btrfs_ioctl_snap_create(struct file *file,
 	}
 
 	if (subvol) {
-		ret = btrfs_mksubvol(&file->f_path, name, namelen,
-				     NULL, readonly, inherit);
+		ret = btrfs_mksubvol(&file->f_path, mnt_userns, name,
+				     namelen, NULL, readonly, inherit);
 	} else {
 		struct fd src = fdget(fd);
 		struct inode *src_inode;
@@ -1834,16 +1848,17 @@ static noinline int __btrfs_ioctl_snap_create(struct file *file,
 			btrfs_info(BTRFS_I(file_inode(file))->root->fs_info,
 				   "Snapshot src from another FS");
 			ret = -EXDEV;
-		} else if (!inode_owner_or_capable(&init_user_ns, src_inode)) {
+		} else if (!inode_owner_or_capable(mnt_userns, src_inode)) {
 			/*
 			 * Subvolume creation is not restricted, but snapshots
 			 * are limited to own subvolumes only
 			 */
 			ret = -EPERM;
 		} else {
-			ret = btrfs_mksnapshot(&file->f_path, name, namelen,
-					     BTRFS_I(src_inode)->root,
-					     readonly, inherit);
+			ret = btrfs_mksnapshot(&file->f_path, mnt_userns,
+					       name, namelen,
+					       BTRFS_I(src_inode)->root,
+					       readonly, inherit);
 		}
 		fdput(src);
 	}
@@ -1867,8 +1882,9 @@ static noinline int btrfs_ioctl_snap_create(struct file *file,
 		return PTR_ERR(vol_args);
 	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
 
-	ret = __btrfs_ioctl_snap_create(file, vol_args->name, vol_args->fd,
-					subvol, false, NULL);
+	ret = __btrfs_ioctl_snap_create(file, file_mnt_user_ns(file),
+					vol_args->name, vol_args->fd, subvol,
+					false, NULL);
 
 	kfree(vol_args);
 	return ret;
@@ -1926,8 +1942,9 @@ static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
 		}
 	}
 
-	ret = __btrfs_ioctl_snap_create(file, vol_args->name, vol_args->fd,
-					subvol, readonly, inherit);
+	ret = __btrfs_ioctl_snap_create(file, file_mnt_user_ns(file),
+					vol_args->name, vol_args->fd, subvol,
+					readonly, inherit);
 	if (ret)
 		goto free_inherit;
 free_inherit:
@@ -1971,7 +1988,7 @@ static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
 	u64 flags;
 	int ret = 0;
 
-	if (!inode_owner_or_capable(&init_user_ns, inode))
+	if (!inode_owner_or_capable(file_mnt_user_ns(file), inode))
 		return -EPERM;
 
 	ret = mnt_want_write_file(file);
@@ -2382,23 +2399,16 @@ static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
 	key.offset = (u64)-1;
 
 	while (1) {
-		ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+		ret = btrfs_search_backwards(root, &key, path);
 		if (ret < 0)
 			goto out;
 		else if (ret > 0) {
-			ret = btrfs_previous_item(root, path, dirid,
-						  BTRFS_INODE_REF_KEY);
-			if (ret < 0)
-				goto out;
-			else if (ret > 0) {
-				ret = -ENOENT;
-				goto out;
-			}
+			ret = -ENOENT;
+			goto out;
 		}
 
 		l = path->nodes[0];
 		slot = path->slots[0];
-		btrfs_item_key_to_cpu(l, &key, slot);
 
 		iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref);
 		len = btrfs_inode_ref_name_len(l, iref);
@@ -2429,7 +2439,8 @@ out:
 	return ret;
 }
 
-static int btrfs_search_path_in_tree_user(struct inode *inode,
+static int btrfs_search_path_in_tree_user(struct user_namespace *mnt_userns,
+				struct inode *inode,
 				struct btrfs_ioctl_ino_lookup_user_args *args)
 {
 	struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
@@ -2473,23 +2484,16 @@ static int btrfs_search_path_in_tree_user(struct inode *inode,
 		key.type = BTRFS_INODE_REF_KEY;
 		key.offset = (u64)-1;
 		while (1) {
-			ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
-			if (ret < 0) {
+			ret = btrfs_search_backwards(root, &key, path);
+			if (ret < 0)
+				goto out_put;
+			else if (ret > 0) {
+				ret = -ENOENT;
 				goto out_put;
-			} else if (ret > 0) {
-				ret = btrfs_previous_item(root, path, dirid,
-							  BTRFS_INODE_REF_KEY);
-				if (ret < 0) {
-					goto out_put;
-				} else if (ret > 0) {
-					ret = -ENOENT;
-					goto out_put;
-				}
 			}
 
 			leaf = path->nodes[0];
 			slot = path->slots[0];
-			btrfs_item_key_to_cpu(leaf, &key, slot);
 
 			iref = btrfs_item_ptr(leaf, slot, struct btrfs_inode_ref);
 			len = btrfs_inode_ref_name_len(leaf, iref);
@@ -2527,7 +2531,7 @@ static int btrfs_search_path_in_tree_user(struct inode *inode,
 				ret = PTR_ERR(temp_inode);
 				goto out_put;
 			}
-			ret = inode_permission(&init_user_ns, temp_inode,
+			ret = inode_permission(mnt_userns, temp_inode,
 					       MAY_READ | MAY_EXEC);
 			iput(temp_inode);
 			if (ret) {
@@ -2669,7 +2673,7 @@ static int btrfs_ioctl_ino_lookup_user(struct file *file, void __user *argp)
 		return -EACCES;
 	}
 
-	ret = btrfs_search_path_in_tree_user(inode, args);
+	ret = btrfs_search_path_in_tree_user(file_mnt_user_ns(file), inode, args);
 
 	if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
 		ret = -EFAULT;
@@ -2905,6 +2909,7 @@ static noinline int btrfs_ioctl_snap_destroy(struct file *file,
 	struct btrfs_root *dest = NULL;
 	struct btrfs_ioctl_vol_args *vol_args = NULL;
 	struct btrfs_ioctl_vol_args_v2 *vol_args2 = NULL;
+	struct user_namespace *mnt_userns = file_mnt_user_ns(file);
 	char *subvol_name, *subvol_name_ptr = NULL;
 	int subvol_namelen;
 	int err = 0;
@@ -2932,6 +2937,8 @@ static noinline int btrfs_ioctl_snap_destroy(struct file *file,
 			if (err)
 				goto out;
 		} else {
+			struct inode *old_dir;
+
 			if (vol_args2->subvolid < BTRFS_FIRST_FREE_OBJECTID) {
 				err = -EINVAL;
 				goto out;
@@ -2968,6 +2975,7 @@ static noinline int btrfs_ioctl_snap_destroy(struct file *file,
 				err = PTR_ERR(parent);
 				goto out_drop_write;
 			}
+			old_dir = dir;
 			dir = d_inode(parent);
 
 			/*
@@ -2978,6 +2986,20 @@ static noinline int btrfs_ioctl_snap_destroy(struct file *file,
 			 */
 			destroy_parent = true;
 
+			/*
+			 * On idmapped mounts, deletion via subvolid is
+			 * restricted to subvolumes that are immediate
+			 * ancestors of the inode referenced by the file
+			 * descriptor in the ioctl. Otherwise the idmapping
+			 * could potentially be abused to delete subvolumes
+			 * anywhere in the filesystem the user wouldn't be able
+			 * to delete without an idmapped mount.
+			 */
+			if (old_dir != dir && mnt_userns != &init_user_ns) {
+				err = -EOPNOTSUPP;
+				goto free_parent;
+			}
+
 			subvol_name_ptr = btrfs_get_subvol_name_from_objectid(
 						fs_info, vol_args2->subvolid);
 			if (IS_ERR(subvol_name_ptr)) {
@@ -3016,7 +3038,7 @@ static noinline int btrfs_ioctl_snap_destroy(struct file *file,
 	err = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
 	if (err == -EINTR)
 		goto free_subvol_name;
-	dentry = lookup_one_len(subvol_name, parent, subvol_namelen);
+	dentry = lookup_one(mnt_userns, subvol_name, parent, subvol_namelen);
 	if (IS_ERR(dentry)) {
 		err = PTR_ERR(dentry);
 		goto out_unlock_dir;
@@ -3058,14 +3080,13 @@ static noinline int btrfs_ioctl_snap_destroy(struct file *file,
 		if (root == dest)
 			goto out_dput;
 
-		err = inode_permission(&init_user_ns, inode,
-				       MAY_WRITE | MAY_EXEC);
+		err = inode_permission(mnt_userns, inode, MAY_WRITE | MAY_EXEC);
 		if (err)
 			goto out_dput;
 	}
 
 	/* check if subvolume may be deleted by a user */
-	err = btrfs_may_delete(dir, dentry, 1);
+	err = btrfs_may_delete(mnt_userns, dir, dentry, 1);
 	if (err)
 		goto out_dput;
 
@@ -3103,7 +3124,7 @@ static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
 {
 	struct inode *inode = file_inode(file);
 	struct btrfs_root *root = BTRFS_I(inode)->root;
-	struct btrfs_ioctl_defrag_range_args *range;
+	struct btrfs_ioctl_defrag_range_args range = {0};
 	int ret;
 
 	ret = mnt_want_write_file(file);
@@ -3115,6 +3136,12 @@ static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
 		goto out;
 	}
 
+	/* Subpage defrag will be supported in later commits */
+	if (root->fs_info->sectorsize < PAGE_SIZE) {
+		ret = -ENOTTY;
+		goto out;
+	}
+
 	switch (inode->i_mode & S_IFMT) {
 	case S_IFDIR:
 		if (!capable(CAP_SYS_ADMIN)) {
@@ -3135,33 +3162,24 @@ static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
 			goto out;
 		}
 
-		range = kzalloc(sizeof(*range), GFP_KERNEL);
-		if (!range) {
-			ret = -ENOMEM;
-			goto out;
-		}
-
 		if (argp) {
-			if (copy_from_user(range, argp,
-					   sizeof(*range))) {
+			if (copy_from_user(&range, argp, sizeof(range))) {
 				ret = -EFAULT;
-				kfree(range);
 				goto out;
 			}
 			/* compression requires us to start the IO */
-			if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
-				range->flags |= BTRFS_DEFRAG_RANGE_START_IO;
-				range->extent_thresh = (u32)-1;
+			if ((range.flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
+				range.flags |= BTRFS_DEFRAG_RANGE_START_IO;
+				range.extent_thresh = (u32)-1;
 			}
 		} else {
 			/* the rest are all set to zero by kzalloc */
-			range->len = (u64)-1;
+			range.len = (u64)-1;
 		}
 		ret = btrfs_defrag_file(file_inode(file), file,
-					range, BTRFS_OLDEST_GENERATION, 0);
+					&range, BTRFS_OLDEST_GENERATION, 0);
 		if (ret > 0)
 			ret = 0;
-		kfree(range);
 		break;
 	default:
 		ret = -EINVAL;
@@ -4404,25 +4422,20 @@ drop_write:
 static long btrfs_ioctl_quota_rescan_status(struct btrfs_fs_info *fs_info,
 						void __user *arg)
 {
-	struct btrfs_ioctl_quota_rescan_args *qsa;
+	struct btrfs_ioctl_quota_rescan_args qsa = {0};
 	int ret = 0;
 
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
 
-	qsa = kzalloc(sizeof(*qsa), GFP_KERNEL);
-	if (!qsa)
-		return -ENOMEM;
-
 	if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
-		qsa->flags = 1;
-		qsa->progress = fs_info->qgroup_rescan_progress.objectid;
+		qsa.flags = 1;
+		qsa.progress = fs_info->qgroup_rescan_progress.objectid;
 	}
 
-	if (copy_to_user(arg, qsa, sizeof(*qsa)))
+	if (copy_to_user(arg, &qsa, sizeof(qsa)))
 		ret = -EFAULT;
 
-	kfree(qsa);
 	return ret;
 }
 
@@ -4436,6 +4449,7 @@ static long btrfs_ioctl_quota_rescan_wait(struct btrfs_fs_info *fs_info,
 }
 
 static long _btrfs_ioctl_set_received_subvol(struct file *file,
+					    struct user_namespace *mnt_userns,
 					    struct btrfs_ioctl_received_subvol_args *sa)
 {
 	struct inode *inode = file_inode(file);
@@ -4447,7 +4461,7 @@ static long _btrfs_ioctl_set_received_subvol(struct file *file,
 	int ret = 0;
 	int received_uuid_changed;
 
-	if (!inode_owner_or_capable(&init_user_ns, inode))
+	if (!inode_owner_or_capable(mnt_userns, inode))
 		return -EPERM;
 
 	ret = mnt_want_write_file(file);
@@ -4552,7 +4566,7 @@ static long btrfs_ioctl_set_received_subvol_32(struct file *file,
 	args64->rtime.nsec = args32->rtime.nsec;
 	args64->flags = args32->flags;
 
-	ret = _btrfs_ioctl_set_received_subvol(file, args64);
+	ret = _btrfs_ioctl_set_received_subvol(file, file_mnt_user_ns(file), args64);
 	if (ret)
 		goto out;
 
@@ -4586,7 +4600,7 @@ static long btrfs_ioctl_set_received_subvol(struct file *file,
 	if (IS_ERR(sa))
 		return PTR_ERR(sa);
 
-	ret = _btrfs_ioctl_set_received_subvol(file, sa);
+	ret = _btrfs_ioctl_set_received_subvol(file, file_mnt_user_ns(file), sa);
 
 	if (ret)
 		goto out;
@@ -5013,6 +5027,10 @@ long btrfs_ioctl(struct file *file, unsigned int
 		return btrfs_ioctl_get_subvol_rootref(file, argp);
 	case BTRFS_IOC_INO_LOOKUP_USER:
 		return btrfs_ioctl_ino_lookup_user(file, argp);
+	case FS_IOC_ENABLE_VERITY:
+		return fsverity_ioctl_enable(file, (const void __user *)argp);
+	case FS_IOC_MEASURE_VERITY:
+		return fsverity_ioctl_measure(file, argp);
 	}
 
 	return -ENOTTY;
diff --git a/fs/btrfs/lzo.c b/fs/btrfs/lzo.c
index cd042c7567a4..c25dfd1a8a54 100644
--- a/fs/btrfs/lzo.c
+++ b/fs/btrfs/lzo.c
@@ -14,6 +14,7 @@
 #include <linux/lzo.h>
 #include <linux/refcount.h>
 #include "compression.h"
+#include "ctree.h"
 
 #define LZO_LEN	4
 
@@ -140,18 +141,18 @@ int lzo_compress_pages(struct list_head *ws, struct address_space *mapping,
 	*total_in = 0;
 
 	in_page = find_get_page(mapping, start >> PAGE_SHIFT);
-	data_in = kmap(in_page);
+	data_in = page_address(in_page);
 
 	/*
 	 * store the size of all chunks of compressed data in
 	 * the first 4 bytes
 	 */
-	out_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
+	out_page = alloc_page(GFP_NOFS);
 	if (out_page == NULL) {
 		ret = -ENOMEM;
 		goto out;
 	}
-	cpage_out = kmap(out_page);
+	cpage_out = page_address(out_page);
 	out_offset = LZO_LEN;
 	tot_out = LZO_LEN;
 	pages[0] = out_page;
@@ -209,19 +210,18 @@ int lzo_compress_pages(struct list_head *ws, struct address_space *mapping,
 				if (out_len == 0 && tot_in >= len)
 					break;
 
-				kunmap(out_page);
 				if (nr_pages == nr_dest_pages) {
 					out_page = NULL;
 					ret = -E2BIG;
 					goto out;
 				}
 
-				out_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
+				out_page = alloc_page(GFP_NOFS);
 				if (out_page == NULL) {
 					ret = -ENOMEM;
 					goto out;
 				}
-				cpage_out = kmap(out_page);
+				cpage_out = page_address(out_page);
 				pages[nr_pages++] = out_page;
 
 				pg_bytes_left = PAGE_SIZE;
@@ -243,12 +243,11 @@ int lzo_compress_pages(struct list_head *ws, struct address_space *mapping,
 			break;
 
 		bytes_left = len - tot_in;
-		kunmap(in_page);
 		put_page(in_page);
 
 		start += PAGE_SIZE;
 		in_page = find_get_page(mapping, start >> PAGE_SHIFT);
-		data_in = kmap(in_page);
+		data_in = page_address(in_page);
 		in_len = min(bytes_left, PAGE_SIZE);
 	}
 
@@ -258,164 +257,130 @@ int lzo_compress_pages(struct list_head *ws, struct address_space *mapping,
 	}
 
 	/* store the size of all chunks of compressed data */
-	sizes_ptr = kmap_local_page(pages[0]);
+	sizes_ptr = page_address(pages[0]);
 	write_compress_length(sizes_ptr, tot_out);
-	kunmap_local(sizes_ptr);
 
 	ret = 0;
 	*total_out = tot_out;
 	*total_in = tot_in;
 out:
 	*out_pages = nr_pages;
-	if (out_page)
-		kunmap(out_page);
 
-	if (in_page) {
-		kunmap(in_page);
+	if (in_page)
 		put_page(in_page);
-	}
 
 	return ret;
 }
 
+/*
+ * Copy the compressed segment payload into @dest.
+ *
+ * For the payload there will be no padding, just need to do page switching.
+ */
+static void copy_compressed_segment(struct compressed_bio *cb,
+				    char *dest, u32 len, u32 *cur_in)
+{
+	u32 orig_in = *cur_in;
+
+	while (*cur_in < orig_in + len) {
+		struct page *cur_page;
+		u32 copy_len = min_t(u32, PAGE_SIZE - offset_in_page(*cur_in),
+					  orig_in + len - *cur_in);
+
+		ASSERT(copy_len);
+		cur_page = cb->compressed_pages[*cur_in / PAGE_SIZE];
+
+		memcpy(dest + *cur_in - orig_in,
+			page_address(cur_page) + offset_in_page(*cur_in),
+			copy_len);
+
+		*cur_in += copy_len;
+	}
+}
+
 int lzo_decompress_bio(struct list_head *ws, struct compressed_bio *cb)
 {
 	struct workspace *workspace = list_entry(ws, struct workspace, list);
-	int ret = 0, ret2;
-	char *data_in;
-	unsigned long page_in_index = 0;
-	size_t srclen = cb->compressed_len;
-	unsigned long total_pages_in = DIV_ROUND_UP(srclen, PAGE_SIZE);
-	unsigned long buf_start;
-	unsigned long buf_offset = 0;
-	unsigned long bytes;
-	unsigned long working_bytes;
-	size_t in_len;
-	size_t out_len;
-	const size_t max_segment_len = lzo1x_worst_compress(PAGE_SIZE);
-	unsigned long in_offset;
-	unsigned long in_page_bytes_left;
-	unsigned long tot_in;
-	unsigned long tot_out;
-	unsigned long tot_len;
-	char *buf;
-	bool may_late_unmap, need_unmap;
-	struct page **pages_in = cb->compressed_pages;
-	u64 disk_start = cb->start;
-	struct bio *orig_bio = cb->orig_bio;
+	const struct btrfs_fs_info *fs_info = btrfs_sb(cb->inode->i_sb);
+	const u32 sectorsize = fs_info->sectorsize;
+	int ret;
+	/* Compressed data length, can be unaligned */
+	u32 len_in;
+	/* Offset inside the compressed data */
+	u32 cur_in = 0;
+	/* Bytes decompressed so far */
+	u32 cur_out = 0;
+
+	len_in = read_compress_length(page_address(cb->compressed_pages[0]));
+	cur_in += LZO_LEN;
 
-	data_in = kmap(pages_in[0]);
-	tot_len = read_compress_length(data_in);
 	/*
-	 * Compressed data header check.
+	 * LZO header length check
 	 *
-	 * The real compressed size can't exceed the maximum extent length, and
-	 * all pages should be used (whole unused page with just the segment
-	 * header is not possible).  If this happens it means the compressed
-	 * extent is corrupted.
+	 * The total length should not exceed the maximum extent length,
+	 * and all sectors should be used.
+	 * If this happens, it means the compressed extent is corrupted.
 	 */
-	if (tot_len > min_t(size_t, BTRFS_MAX_COMPRESSED, srclen) ||
-	    tot_len < srclen - PAGE_SIZE) {
-		ret = -EUCLEAN;
-		goto done;
+	if (len_in > min_t(size_t, BTRFS_MAX_COMPRESSED, cb->compressed_len) ||
+	    round_up(len_in, sectorsize) < cb->compressed_len) {
+		btrfs_err(fs_info,
+			"invalid lzo header, lzo len %u compressed len %u",
+			len_in, cb->compressed_len);
+		return -EUCLEAN;
 	}
 
-	tot_in = LZO_LEN;
-	in_offset = LZO_LEN;
-	in_page_bytes_left = PAGE_SIZE - LZO_LEN;
-
-	tot_out = 0;
-
-	while (tot_in < tot_len) {
-		in_len = read_compress_length(data_in + in_offset);
-		in_page_bytes_left -= LZO_LEN;
-		in_offset += LZO_LEN;
-		tot_in += LZO_LEN;
+	/* Go through each lzo segment */
+	while (cur_in < len_in) {
+		struct page *cur_page;
+		/* Length of the compressed segment */
+		u32 seg_len;
+		u32 sector_bytes_left;
+		size_t out_len = lzo1x_worst_compress(sectorsize);
 
 		/*
-		 * Segment header check.
-		 *
-		 * The segment length must not exceed the maximum LZO
-		 * compression size, nor the total compressed size.
+		 * We should always have enough space for one segment header
+		 * inside current sector.
 		 */
-		if (in_len > max_segment_len || tot_in + in_len > tot_len) {
-			ret = -EUCLEAN;
-			goto done;
-		}
-
-		tot_in += in_len;
-		working_bytes = in_len;
-		may_late_unmap = need_unmap = false;
-
-		/* fast path: avoid using the working buffer */
-		if (in_page_bytes_left >= in_len) {
-			buf = data_in + in_offset;
-			bytes = in_len;
-			may_late_unmap = true;
-			goto cont;
-		}
-
-		/* copy bytes from the pages into the working buffer */
-		buf = workspace->cbuf;
-		buf_offset = 0;
-		while (working_bytes) {
-			bytes = min(working_bytes, in_page_bytes_left);
-
-			memcpy(buf + buf_offset, data_in + in_offset, bytes);
-			buf_offset += bytes;
-cont:
-			working_bytes -= bytes;
-			in_page_bytes_left -= bytes;
-			in_offset += bytes;
-
-			/* check if we need to pick another page */
-			if ((working_bytes == 0 && in_page_bytes_left < LZO_LEN)
-			    || in_page_bytes_left == 0) {
-				tot_in += in_page_bytes_left;
-
-				if (working_bytes == 0 && tot_in >= tot_len)
-					break;
-
-				if (page_in_index + 1 >= total_pages_in) {
-					ret = -EIO;
-					goto done;
-				}
-
-				if (may_late_unmap)
-					need_unmap = true;
-				else
-					kunmap(pages_in[page_in_index]);
-
-				data_in = kmap(pages_in[++page_in_index]);
-
-				in_page_bytes_left = PAGE_SIZE;
-				in_offset = 0;
-			}
-		}
-
-		out_len = max_segment_len;
-		ret = lzo1x_decompress_safe(buf, in_len, workspace->buf,
-					    &out_len);
-		if (need_unmap)
-			kunmap(pages_in[page_in_index - 1]);
+		ASSERT(cur_in / sectorsize ==
+		       (cur_in + LZO_LEN - 1) / sectorsize);
+		cur_page = cb->compressed_pages[cur_in / PAGE_SIZE];
+		ASSERT(cur_page);
+		seg_len = read_compress_length(page_address(cur_page) +
+					       offset_in_page(cur_in));
+		cur_in += LZO_LEN;
+
+		/* Copy the compressed segment payload into workspace */
+		copy_compressed_segment(cb, workspace->cbuf, seg_len, &cur_in);
+
+		/* Decompress the data */
+		ret = lzo1x_decompress_safe(workspace->cbuf, seg_len,
+					    workspace->buf, &out_len);
 		if (ret != LZO_E_OK) {
-			pr_warn("BTRFS: decompress failed\n");
+			btrfs_err(fs_info, "failed to decompress");
 			ret = -EIO;
-			break;
+			goto out;
 		}
 
-		buf_start = tot_out;
-		tot_out += out_len;
+		/* Copy the data into inode pages */
+		ret = btrfs_decompress_buf2page(workspace->buf, out_len, cb, cur_out);
+		cur_out += out_len;
 
-		ret2 = btrfs_decompress_buf2page(workspace->buf, buf_start,
-						 tot_out, disk_start, orig_bio);
-		if (ret2 == 0)
-			break;
+		/* All data read, exit */
+		if (ret == 0)
+			goto out;
+		ret = 0;
+
+		/* Check if the sector has enough space for a segment header */
+		sector_bytes_left = sectorsize - (cur_in % sectorsize);
+		if (sector_bytes_left >= LZO_LEN)
+			continue;
+
+		/* Skip the padding zeros */
+		cur_in += sector_bytes_left;
 	}
-done:
-	kunmap(pages_in[page_in_index]);
+out:
 	if (!ret)
-		zero_fill_bio(orig_bio);
+		zero_fill_bio(cb->orig_bio);
 	return ret;
 }
 
@@ -466,7 +431,7 @@ int lzo_decompress(struct list_head *ws, unsigned char *data_in,
 	destlen = min_t(unsigned long, destlen, PAGE_SIZE);
 	bytes = min_t(unsigned long, destlen, out_len - start_byte);
 
-	kaddr = kmap_local_page(dest_page);
+	kaddr = page_address(dest_page);
 	memcpy(kaddr, workspace->buf + start_byte, bytes);
 
 	/*
@@ -476,7 +441,6 @@ int lzo_decompress(struct list_head *ws, unsigned char *data_in,
 	 */
 	if (bytes < destlen)
 		memset(kaddr+bytes, 0, destlen-bytes);
-	kunmap_local(kaddr);
 out:
 	return ret;
 }
diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c
index 5c0f8481e25e..edb65abf0393 100644
--- a/fs/btrfs/ordered-data.c
+++ b/fs/btrfs/ordered-data.c
@@ -446,7 +446,6 @@ void btrfs_mark_ordered_io_finished(struct btrfs_inode *inode,
  * 		 Will be also used to store the finished ordered extent.
  * @file_offset: File offset for the finished IO
  * @io_size:	 Length of the finish IO range
- * @uptodate:	 If the IO finishes without problem
  *
  * Return true if the ordered extent is finished in the range, and update
  * @cached.
@@ -457,7 +456,7 @@ void btrfs_mark_ordered_io_finished(struct btrfs_inode *inode,
  */
 bool btrfs_dec_test_ordered_pending(struct btrfs_inode *inode,
 				    struct btrfs_ordered_extent **cached,
-				    u64 file_offset, u64 io_size, int uptodate)
+				    u64 file_offset, u64 io_size)
 {
 	struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree;
 	struct rb_node *node;
@@ -486,8 +485,6 @@ have_entry:
 		       entry->bytes_left, io_size);
 
 	entry->bytes_left -= io_size;
-	if (!uptodate)
-		set_bit(BTRFS_ORDERED_IOERR, &entry->flags);
 
 	if (entry->bytes_left == 0) {
 		/*
diff --git a/fs/btrfs/ordered-data.h b/fs/btrfs/ordered-data.h
index b2d88aba8420..4194e960ff61 100644
--- a/fs/btrfs/ordered-data.h
+++ b/fs/btrfs/ordered-data.h
@@ -177,7 +177,7 @@ void btrfs_mark_ordered_io_finished(struct btrfs_inode *inode,
 				bool uptodate);
 bool btrfs_dec_test_ordered_pending(struct btrfs_inode *inode,
 				    struct btrfs_ordered_extent **cached,
-				    u64 file_offset, u64 io_size, int uptodate);
+				    u64 file_offset, u64 io_size);
 int btrfs_add_ordered_extent(struct btrfs_inode *inode, u64 file_offset,
 			     u64 disk_bytenr, u64 num_bytes, u64 disk_num_bytes,
 			     int type);
diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index 0fa121171ca1..db680f5be745 100644
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -1733,7 +1733,7 @@ int btrfs_qgroup_trace_extent_post(struct btrfs_trans_handle *trans,
 	ASSERT(trans != NULL);
 
 	ret = btrfs_find_all_roots(NULL, trans->fs_info, bytenr, 0, &old_root,
-				   false, true);
+				   true);
 	if (ret < 0) {
 		trans->fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
 		btrfs_warn(trans->fs_info,
@@ -2651,7 +2651,7 @@ int btrfs_qgroup_account_extents(struct btrfs_trans_handle *trans)
 				/* Search commit root to find old_roots */
 				ret = btrfs_find_all_roots(NULL, fs_info,
 						record->bytenr, 0,
-						&record->old_roots, false, false);
+						&record->old_roots, false);
 				if (ret < 0)
 					goto cleanup;
 			}
@@ -2667,7 +2667,7 @@ int btrfs_qgroup_account_extents(struct btrfs_trans_handle *trans)
 			 * current root. It's safe inside commit_transaction().
 			 */
 			ret = btrfs_find_all_roots(trans, fs_info,
-			   record->bytenr, BTRFS_SEQ_LAST, &new_roots, false, false);
+			   record->bytenr, BTRFS_SEQ_LAST, &new_roots, false);
 			if (ret < 0)
 				goto cleanup;
 			if (qgroup_to_skip) {
@@ -3201,7 +3201,7 @@ static int qgroup_rescan_leaf(struct btrfs_trans_handle *trans,
 			num_bytes = found.offset;
 
 		ret = btrfs_find_all_roots(NULL, fs_info, found.objectid, 0,
-					   &roots, false, false);
+					   &roots, false);
 		if (ret < 0)
 			goto out;
 		/* For rescan, just pass old_roots as NULL */
diff --git a/fs/btrfs/raid56.c b/fs/btrfs/raid56.c
index 244d499ebc72..d8d268ca8aa7 100644
--- a/fs/btrfs/raid56.c
+++ b/fs/btrfs/raid56.c
@@ -1035,7 +1035,7 @@ static int alloc_rbio_pages(struct btrfs_raid_bio *rbio)
 	for (i = 0; i < rbio->nr_pages; i++) {
 		if (rbio->stripe_pages[i])
 			continue;
-		page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
+		page = alloc_page(GFP_NOFS);
 		if (!page)
 			return -ENOMEM;
 		rbio->stripe_pages[i] = page;
@@ -1054,7 +1054,7 @@ static int alloc_rbio_parity_pages(struct btrfs_raid_bio *rbio)
 	for (; i < rbio->nr_pages; i++) {
 		if (rbio->stripe_pages[i])
 			continue;
-		page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
+		page = alloc_page(GFP_NOFS);
 		if (!page)
 			return -ENOMEM;
 		rbio->stripe_pages[i] = page;
@@ -1636,10 +1636,10 @@ struct btrfs_plug_cb {
 static int plug_cmp(void *priv, const struct list_head *a,
 		    const struct list_head *b)
 {
-	struct btrfs_raid_bio *ra = container_of(a, struct btrfs_raid_bio,
-						 plug_list);
-	struct btrfs_raid_bio *rb = container_of(b, struct btrfs_raid_bio,
-						 plug_list);
+	const struct btrfs_raid_bio *ra = container_of(a, struct btrfs_raid_bio,
+						       plug_list);
+	const struct btrfs_raid_bio *rb = container_of(b, struct btrfs_raid_bio,
+						       plug_list);
 	u64 a_sector = ra->bio_list.head->bi_iter.bi_sector;
 	u64 b_sector = rb->bio_list.head->bi_iter.bi_sector;
 
@@ -2300,7 +2300,7 @@ static int alloc_rbio_essential_pages(struct btrfs_raid_bio *rbio)
 			if (rbio->stripe_pages[index])
 				continue;
 
-			page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
+			page = alloc_page(GFP_NOFS);
 			if (!page)
 				return -ENOMEM;
 			rbio->stripe_pages[index] = page;
@@ -2350,14 +2350,14 @@ static noinline void finish_parity_scrub(struct btrfs_raid_bio *rbio,
 	if (!need_check)
 		goto writeback;
 
-	p_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
+	p_page = alloc_page(GFP_NOFS);
 	if (!p_page)
 		goto cleanup;
 	SetPageUptodate(p_page);
 
 	if (has_qstripe) {
 		/* RAID6, allocate and map temp space for the Q stripe */
-		q_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
+		q_page = alloc_page(GFP_NOFS);
 		if (!q_page) {
 			__free_page(p_page);
 			goto cleanup;
diff --git a/fs/btrfs/ref-verify.c b/fs/btrfs/ref-verify.c
index 8e026de74c44..d2062d5f71dd 100644
--- a/fs/btrfs/ref-verify.c
+++ b/fs/btrfs/ref-verify.c
@@ -264,8 +264,8 @@ static struct block_entry *add_block_entry(struct btrfs_fs_info *fs_info,
 	struct block_entry *be = NULL, *exist;
 	struct root_entry *re = NULL;
 
-	re = kzalloc(sizeof(struct root_entry), GFP_KERNEL);
-	be = kzalloc(sizeof(struct block_entry), GFP_KERNEL);
+	re = kzalloc(sizeof(struct root_entry), GFP_NOFS);
+	be = kzalloc(sizeof(struct block_entry), GFP_NOFS);
 	if (!be || !re) {
 		kfree(re);
 		kfree(be);
@@ -313,7 +313,7 @@ static int add_tree_block(struct btrfs_fs_info *fs_info, u64 ref_root,
 	struct root_entry *re;
 	struct ref_entry *ref = NULL, *exist;
 
-	ref = kmalloc(sizeof(struct ref_entry), GFP_KERNEL);
+	ref = kmalloc(sizeof(struct ref_entry), GFP_NOFS);
 	if (!ref)
 		return -ENOMEM;
 
@@ -358,7 +358,7 @@ static int add_shared_data_ref(struct btrfs_fs_info *fs_info,
 	struct block_entry *be;
 	struct ref_entry *ref;
 
-	ref = kzalloc(sizeof(struct ref_entry), GFP_KERNEL);
+	ref = kzalloc(sizeof(struct ref_entry), GFP_NOFS);
 	if (!ref)
 		return -ENOMEM;
 	be = add_block_entry(fs_info, bytenr, num_bytes, 0);
@@ -393,7 +393,7 @@ static int add_extent_data_ref(struct btrfs_fs_info *fs_info,
 	u64 offset = btrfs_extent_data_ref_offset(leaf, dref);
 	u32 num_refs = btrfs_extent_data_ref_count(leaf, dref);
 
-	ref = kzalloc(sizeof(struct ref_entry), GFP_KERNEL);
+	ref = kzalloc(sizeof(struct ref_entry), GFP_NOFS);
 	if (!ref)
 		return -ENOMEM;
 	be = add_block_entry(fs_info, bytenr, num_bytes, ref_root);
diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index fc831597cb22..914d403b4415 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -24,6 +24,7 @@
 #include "block-group.h"
 #include "backref.h"
 #include "misc.h"
+#include "subpage.h"
 
 /*
  * Relocation overview
@@ -2781,10 +2782,70 @@ static noinline_for_stack int prealloc_file_extent_cluster(
 	u64 num_bytes;
 	int nr;
 	int ret = 0;
+	u64 i_size = i_size_read(&inode->vfs_inode);
 	u64 prealloc_start = cluster->start - offset;
 	u64 prealloc_end = cluster->end - offset;
 	u64 cur_offset = prealloc_start;
 
+	/*
+	 * For subpage case, previous i_size may not be aligned to PAGE_SIZE.
+	 * This means the range [i_size, PAGE_END + 1) is filled with zeros by
+	 * btrfs_do_readpage() call of previously relocated file cluster.
+	 *
+	 * If the current cluster starts in the above range, btrfs_do_readpage()
+	 * will skip the read, and relocate_one_page() will later writeback
+	 * the padding zeros as new data, causing data corruption.
+	 *
+	 * Here we have to manually invalidate the range (i_size, PAGE_END + 1).
+	 */
+	if (!IS_ALIGNED(i_size, PAGE_SIZE)) {
+		struct address_space *mapping = inode->vfs_inode.i_mapping;
+		struct btrfs_fs_info *fs_info = inode->root->fs_info;
+		const u32 sectorsize = fs_info->sectorsize;
+		struct page *page;
+
+		ASSERT(sectorsize < PAGE_SIZE);
+		ASSERT(IS_ALIGNED(i_size, sectorsize));
+
+		/*
+		 * Subpage can't handle page with DIRTY but without UPTODATE
+		 * bit as it can lead to the following deadlock:
+		 *
+		 * btrfs_readpage()
+		 * | Page already *locked*
+		 * |- btrfs_lock_and_flush_ordered_range()
+		 *    |- btrfs_start_ordered_extent()
+		 *       |- extent_write_cache_pages()
+		 *          |- lock_page()
+		 *             We try to lock the page we already hold.
+		 *
+		 * Here we just writeback the whole data reloc inode, so that
+		 * we will be ensured to have no dirty range in the page, and
+		 * are safe to clear the uptodate bits.
+		 *
+		 * This shouldn't cause too much overhead, as we need to write
+		 * the data back anyway.
+		 */
+		ret = filemap_write_and_wait(mapping);
+		if (ret < 0)
+			return ret;
+
+		clear_extent_bits(&inode->io_tree, i_size,
+				  round_up(i_size, PAGE_SIZE) - 1,
+				  EXTENT_UPTODATE);
+		page = find_lock_page(mapping, i_size >> PAGE_SHIFT);
+		/*
+		 * If page is freed we don't need to do anything then, as we
+		 * will re-read the whole page anyway.
+		 */
+		if (page) {
+			btrfs_subpage_clear_uptodate(fs_info, page, i_size,
+					round_up(i_size, PAGE_SIZE) - i_size);
+			unlock_page(page);
+			put_page(page);
+		}
+	}
+
 	BUG_ON(cluster->start != cluster->boundary[0]);
 	ret = btrfs_alloc_data_chunk_ondemand(inode,
 					      prealloc_end + 1 - prealloc_start);
@@ -2886,19 +2947,149 @@ noinline int btrfs_should_cancel_balance(struct btrfs_fs_info *fs_info)
 }
 ALLOW_ERROR_INJECTION(btrfs_should_cancel_balance, TRUE);
 
-static int relocate_file_extent_cluster(struct inode *inode,
-					struct file_extent_cluster *cluster)
+static u64 get_cluster_boundary_end(struct file_extent_cluster *cluster,
+				    int cluster_nr)
+{
+	/* Last extent, use cluster end directly */
+	if (cluster_nr >= cluster->nr - 1)
+		return cluster->end;
+
+	/* Use next boundary start*/
+	return cluster->boundary[cluster_nr + 1] - 1;
+}
+
+static int relocate_one_page(struct inode *inode, struct file_ra_state *ra,
+			     struct file_extent_cluster *cluster,
+			     int *cluster_nr, unsigned long page_index)
 {
 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
+	u64 offset = BTRFS_I(inode)->index_cnt;
+	const unsigned long last_index = (cluster->end - offset) >> PAGE_SHIFT;
+	gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
+	struct page *page;
 	u64 page_start;
 	u64 page_end;
+	u64 cur;
+	int ret;
+
+	ASSERT(page_index <= last_index);
+	page = find_lock_page(inode->i_mapping, page_index);
+	if (!page) {
+		page_cache_sync_readahead(inode->i_mapping, ra, NULL,
+				page_index, last_index + 1 - page_index);
+		page = find_or_create_page(inode->i_mapping, page_index, mask);
+		if (!page)
+			return -ENOMEM;
+	}
+	ret = set_page_extent_mapped(page);
+	if (ret < 0)
+		goto release_page;
+
+	if (PageReadahead(page))
+		page_cache_async_readahead(inode->i_mapping, ra, NULL, page,
+				   page_index, last_index + 1 - page_index);
+
+	if (!PageUptodate(page)) {
+		btrfs_readpage(NULL, page);
+		lock_page(page);
+		if (!PageUptodate(page)) {
+			ret = -EIO;
+			goto release_page;
+		}
+	}
+
+	page_start = page_offset(page);
+	page_end = page_start + PAGE_SIZE - 1;
+
+	/*
+	 * Start from the cluster, as for subpage case, the cluster can start
+	 * inside the page.
+	 */
+	cur = max(page_start, cluster->boundary[*cluster_nr] - offset);
+	while (cur <= page_end) {
+		u64 extent_start = cluster->boundary[*cluster_nr] - offset;
+		u64 extent_end = get_cluster_boundary_end(cluster,
+						*cluster_nr) - offset;
+		u64 clamped_start = max(page_start, extent_start);
+		u64 clamped_end = min(page_end, extent_end);
+		u32 clamped_len = clamped_end + 1 - clamped_start;
+
+		/* Reserve metadata for this range */
+		ret = btrfs_delalloc_reserve_metadata(BTRFS_I(inode),
+						      clamped_len);
+		if (ret)
+			goto release_page;
+
+		/* Mark the range delalloc and dirty for later writeback */
+		lock_extent(&BTRFS_I(inode)->io_tree, clamped_start, clamped_end);
+		ret = btrfs_set_extent_delalloc(BTRFS_I(inode), clamped_start,
+						clamped_end, 0, NULL);
+		if (ret) {
+			clear_extent_bits(&BTRFS_I(inode)->io_tree,
+					clamped_start, clamped_end,
+					EXTENT_LOCKED | EXTENT_BOUNDARY);
+			btrfs_delalloc_release_metadata(BTRFS_I(inode),
+							clamped_len, true);
+			btrfs_delalloc_release_extents(BTRFS_I(inode),
+						       clamped_len);
+			goto release_page;
+		}
+		btrfs_page_set_dirty(fs_info, page, clamped_start, clamped_len);
+
+		/*
+		 * Set the boundary if it's inside the page.
+		 * Data relocation requires the destination extents to have the
+		 * same size as the source.
+		 * EXTENT_BOUNDARY bit prevents current extent from being merged
+		 * with previous extent.
+		 */
+		if (in_range(cluster->boundary[*cluster_nr] - offset,
+			     page_start, PAGE_SIZE)) {
+			u64 boundary_start = cluster->boundary[*cluster_nr] -
+						offset;
+			u64 boundary_end = boundary_start +
+					   fs_info->sectorsize - 1;
+
+			set_extent_bits(&BTRFS_I(inode)->io_tree,
+					boundary_start, boundary_end,
+					EXTENT_BOUNDARY);
+		}
+		unlock_extent(&BTRFS_I(inode)->io_tree, clamped_start, clamped_end);
+		btrfs_delalloc_release_extents(BTRFS_I(inode), clamped_len);
+		cur += clamped_len;
+
+		/* Crossed extent end, go to next extent */
+		if (cur >= extent_end) {
+			(*cluster_nr)++;
+			/* Just finished the last extent of the cluster, exit. */
+			if (*cluster_nr >= cluster->nr)
+				break;
+		}
+	}
+	unlock_page(page);
+	put_page(page);
+
+	balance_dirty_pages_ratelimited(inode->i_mapping);
+	btrfs_throttle(fs_info);
+	if (btrfs_should_cancel_balance(fs_info))
+		ret = -ECANCELED;
+	return ret;
+
+release_page:
+	unlock_page(page);
+	put_page(page);
+	return ret;
+}
+
+static int relocate_file_extent_cluster(struct inode *inode,
+					struct file_extent_cluster *cluster)
+{
+	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 	u64 offset = BTRFS_I(inode)->index_cnt;
 	unsigned long index;
 	unsigned long last_index;
-	struct page *page;
 	struct file_ra_state *ra;
-	gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
-	int nr = 0;
+	int cluster_nr = 0;
 	int ret = 0;
 
 	if (!cluster->nr)
@@ -2919,109 +3110,14 @@ static int relocate_file_extent_cluster(struct inode *inode,
 	if (ret)
 		goto out;
 
-	index = (cluster->start - offset) >> PAGE_SHIFT;
 	last_index = (cluster->end - offset) >> PAGE_SHIFT;
-	while (index <= last_index) {
-		ret = btrfs_delalloc_reserve_metadata(BTRFS_I(inode),
-				PAGE_SIZE);
-		if (ret)
-			goto out;
-
-		page = find_lock_page(inode->i_mapping, index);
-		if (!page) {
-			page_cache_sync_readahead(inode->i_mapping,
-						  ra, NULL, index,
-						  last_index + 1 - index);
-			page = find_or_create_page(inode->i_mapping, index,
-						   mask);
-			if (!page) {
-				btrfs_delalloc_release_metadata(BTRFS_I(inode),
-							PAGE_SIZE, true);
-				btrfs_delalloc_release_extents(BTRFS_I(inode),
-							PAGE_SIZE);
-				ret = -ENOMEM;
-				goto out;
-			}
-		}
-		ret = set_page_extent_mapped(page);
-		if (ret < 0) {
-			btrfs_delalloc_release_metadata(BTRFS_I(inode),
-							PAGE_SIZE, true);
-			btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE);
-			unlock_page(page);
-			put_page(page);
-			goto out;
-		}
-
-		if (PageReadahead(page)) {
-			page_cache_async_readahead(inode->i_mapping,
-						   ra, NULL, page, index,
-						   last_index + 1 - index);
-		}
-
-		if (!PageUptodate(page)) {
-			btrfs_readpage(NULL, page);
-			lock_page(page);
-			if (!PageUptodate(page)) {
-				unlock_page(page);
-				put_page(page);
-				btrfs_delalloc_release_metadata(BTRFS_I(inode),
-							PAGE_SIZE, true);
-				btrfs_delalloc_release_extents(BTRFS_I(inode),
-							       PAGE_SIZE);
-				ret = -EIO;
-				goto out;
-			}
-		}
-
-		page_start = page_offset(page);
-		page_end = page_start + PAGE_SIZE - 1;
-
-		lock_extent(&BTRFS_I(inode)->io_tree, page_start, page_end);
-
-		if (nr < cluster->nr &&
-		    page_start + offset == cluster->boundary[nr]) {
-			set_extent_bits(&BTRFS_I(inode)->io_tree,
-					page_start, page_end,
-					EXTENT_BOUNDARY);
-			nr++;
-		}
-
-		ret = btrfs_set_extent_delalloc(BTRFS_I(inode), page_start,
-						page_end, 0, NULL);
-		if (ret) {
-			unlock_page(page);
-			put_page(page);
-			btrfs_delalloc_release_metadata(BTRFS_I(inode),
-							 PAGE_SIZE, true);
-			btrfs_delalloc_release_extents(BTRFS_I(inode),
-			                               PAGE_SIZE);
-
-			clear_extent_bits(&BTRFS_I(inode)->io_tree,
-					  page_start, page_end,
-					  EXTENT_LOCKED | EXTENT_BOUNDARY);
-			goto out;
-
-		}
-		set_page_dirty(page);
-
-		unlock_extent(&BTRFS_I(inode)->io_tree,
-			      page_start, page_end);
-		unlock_page(page);
-		put_page(page);
-
-		index++;
-		btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE);
-		balance_dirty_pages_ratelimited(inode->i_mapping);
-		btrfs_throttle(fs_info);
-		if (btrfs_should_cancel_balance(fs_info)) {
-			ret = -ECANCELED;
-			goto out;
-		}
-	}
-	WARN_ON(nr != cluster->nr);
+	for (index = (cluster->start - offset) >> PAGE_SHIFT;
+	     index <= last_index && !ret; index++)
+		ret = relocate_one_page(inode, ra, cluster, &cluster_nr, index);
 	if (btrfs_is_zoned(fs_info) && !ret)
 		ret = btrfs_wait_ordered_range(inode, 0, (u64)-1);
+	if (ret == 0)
+		WARN_ON(cluster_nr != cluster->nr);
 out:
 	kfree(ra);
 	return ret;
diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c
index 6ac37ae6c811..72f9b865e847 100644
--- a/fs/btrfs/send.c
+++ b/fs/btrfs/send.c
@@ -1198,7 +1198,7 @@ struct backref_ctx {
 static int __clone_root_cmp_bsearch(const void *key, const void *elt)
 {
 	u64 root = (u64)(uintptr_t)key;
-	struct clone_root *cr = (struct clone_root *)elt;
+	const struct clone_root *cr = elt;
 
 	if (root < cr->root->root_key.objectid)
 		return -1;
@@ -1209,8 +1209,8 @@ static int __clone_root_cmp_bsearch(const void *key, const void *elt)
 
 static int __clone_root_cmp_sort(const void *e1, const void *e2)
 {
-	struct clone_root *cr1 = (struct clone_root *)e1;
-	struct clone_root *cr2 = (struct clone_root *)e2;
+	const struct clone_root *cr1 = e1;
+	const struct clone_root *cr2 = e2;
 
 	if (cr1->root->root_key.objectid < cr2->root->root_key.objectid)
 		return -1;
@@ -1307,7 +1307,7 @@ static int find_extent_clone(struct send_ctx *sctx,
 	u64 flags = 0;
 	struct btrfs_file_extent_item *fi;
 	struct extent_buffer *eb = path->nodes[0];
-	struct backref_ctx *backref_ctx = NULL;
+	struct backref_ctx backref_ctx = {0};
 	struct clone_root *cur_clone_root;
 	struct btrfs_key found_key;
 	struct btrfs_path *tmp_path;
@@ -1322,12 +1322,6 @@ static int find_extent_clone(struct send_ctx *sctx,
 	/* We only use this path under the commit sem */
 	tmp_path->need_commit_sem = 0;
 
-	backref_ctx = kmalloc(sizeof(*backref_ctx), GFP_KERNEL);
-	if (!backref_ctx) {
-		ret = -ENOMEM;
-		goto out;
-	}
-
 	if (data_offset >= ino_size) {
 		/*
 		 * There may be extents that lie behind the file's size.
@@ -1392,12 +1386,12 @@ static int find_extent_clone(struct send_ctx *sctx,
 		cur_clone_root->found_refs = 0;
 	}
 
-	backref_ctx->sctx = sctx;
-	backref_ctx->found = 0;
-	backref_ctx->cur_objectid = ino;
-	backref_ctx->cur_offset = data_offset;
-	backref_ctx->found_itself = 0;
-	backref_ctx->extent_len = num_bytes;
+	backref_ctx.sctx = sctx;
+	backref_ctx.found = 0;
+	backref_ctx.cur_objectid = ino;
+	backref_ctx.cur_offset = data_offset;
+	backref_ctx.found_itself = 0;
+	backref_ctx.extent_len = num_bytes;
 
 	/*
 	 * The last extent of a file may be too large due to page alignment.
@@ -1405,7 +1399,7 @@ static int find_extent_clone(struct send_ctx *sctx,
 	 * __iterate_backrefs work.
 	 */
 	if (data_offset + num_bytes >= ino_size)
-		backref_ctx->extent_len = ino_size - data_offset;
+		backref_ctx.extent_len = ino_size - data_offset;
 
 	/*
 	 * Now collect all backrefs.
@@ -1416,12 +1410,12 @@ static int find_extent_clone(struct send_ctx *sctx,
 		extent_item_pos = 0;
 	ret = iterate_extent_inodes(fs_info, found_key.objectid,
 				    extent_item_pos, 1, __iterate_backrefs,
-				    backref_ctx, false);
+				    &backref_ctx, false);
 
 	if (ret < 0)
 		goto out;
 
-	if (!backref_ctx->found_itself) {
+	if (!backref_ctx.found_itself) {
 		/* found a bug in backref code? */
 		ret = -EIO;
 		btrfs_err(fs_info,
@@ -1434,7 +1428,7 @@ static int find_extent_clone(struct send_ctx *sctx,
 		    "find_extent_clone: data_offset=%llu, ino=%llu, num_bytes=%llu, logical=%llu",
 		    data_offset, ino, num_bytes, logical);
 
-	if (!backref_ctx->found)
+	if (!backref_ctx.found)
 		btrfs_debug(fs_info, "no clones found");
 
 	cur_clone_root = NULL;
@@ -1458,7 +1452,6 @@ static int find_extent_clone(struct send_ctx *sctx,
 
 out:
 	btrfs_free_path(tmp_path);
-	kfree(backref_ctx);
 	return ret;
 }
 
diff --git a/fs/btrfs/space-info.c b/fs/btrfs/space-info.c
index f79bf85f2439..5ada02e0e629 100644
--- a/fs/btrfs/space-info.c
+++ b/fs/btrfs/space-info.c
@@ -493,6 +493,11 @@ static void shrink_delalloc(struct btrfs_fs_info *fs_info,
 	long time_left;
 	int loops;
 
+	delalloc_bytes = percpu_counter_sum_positive(&fs_info->delalloc_bytes);
+	ordered_bytes = percpu_counter_sum_positive(&fs_info->ordered_bytes);
+	if (delalloc_bytes == 0 && ordered_bytes == 0)
+		return;
+
 	/* Calc the number of the pages we need flush for space reservation */
 	if (to_reclaim == U64_MAX) {
 		items = U64_MAX;
@@ -500,22 +505,21 @@ static void shrink_delalloc(struct btrfs_fs_info *fs_info,
 		/*
 		 * to_reclaim is set to however much metadata we need to
 		 * reclaim, but reclaiming that much data doesn't really track
-		 * exactly, so increase the amount to reclaim by 2x in order to
-		 * make sure we're flushing enough delalloc to hopefully reclaim
-		 * some metadata reservations.
+		 * exactly.  What we really want to do is reclaim full inode's
+		 * worth of reservations, however that's not available to us
+		 * here.  We will take a fraction of the delalloc bytes for our
+		 * flushing loops and hope for the best.  Delalloc will expand
+		 * the amount we write to cover an entire dirty extent, which
+		 * will reclaim the metadata reservation for that range.  If
+		 * it's not enough subsequent flush stages will be more
+		 * aggressive.
 		 */
+		to_reclaim = max(to_reclaim, delalloc_bytes >> 3);
 		items = calc_reclaim_items_nr(fs_info, to_reclaim) * 2;
-		to_reclaim = items * EXTENT_SIZE_PER_ITEM;
 	}
 
 	trans = (struct btrfs_trans_handle *)current->journal_info;
 
-	delalloc_bytes = percpu_counter_sum_positive(
-						&fs_info->delalloc_bytes);
-	ordered_bytes = percpu_counter_sum_positive(&fs_info->ordered_bytes);
-	if (delalloc_bytes == 0 && ordered_bytes == 0)
-		return;
-
 	/*
 	 * If we are doing more ordered than delalloc we need to just wait on
 	 * ordered extents, otherwise we'll waste time trying to flush delalloc
@@ -528,9 +532,49 @@ static void shrink_delalloc(struct btrfs_fs_info *fs_info,
 	while ((delalloc_bytes || ordered_bytes) && loops < 3) {
 		u64 temp = min(delalloc_bytes, to_reclaim) >> PAGE_SHIFT;
 		long nr_pages = min_t(u64, temp, LONG_MAX);
+		int async_pages;
 
 		btrfs_start_delalloc_roots(fs_info, nr_pages, true);
 
+		/*
+		 * We need to make sure any outstanding async pages are now
+		 * processed before we continue.  This is because things like
+		 * sync_inode() try to be smart and skip writing if the inode is
+		 * marked clean.  We don't use filemap_fwrite for flushing
+		 * because we want to control how many pages we write out at a
+		 * time, thus this is the only safe way to make sure we've
+		 * waited for outstanding compressed workers to have started
+		 * their jobs and thus have ordered extents set up properly.
+		 *
+		 * This exists because we do not want to wait for each
+		 * individual inode to finish its async work, we simply want to
+		 * start the IO on everybody, and then come back here and wait
+		 * for all of the async work to catch up.  Once we're done with
+		 * that we know we'll have ordered extents for everything and we
+		 * can decide if we wait for that or not.
+		 *
+		 * If we choose to replace this in the future, make absolutely
+		 * sure that the proper waiting is being done in the async case,
+		 * as there have been bugs in that area before.
+		 */
+		async_pages = atomic_read(&fs_info->async_delalloc_pages);
+		if (!async_pages)
+			goto skip_async;
+
+		/*
+		 * We don't want to wait forever, if we wrote less pages in this
+		 * loop than we have outstanding, only wait for that number of
+		 * pages, otherwise we can wait for all async pages to finish
+		 * before continuing.
+		 */
+		if (async_pages > nr_pages)
+			async_pages -= nr_pages;
+		else
+			async_pages = 0;
+		wait_event(fs_info->async_submit_wait,
+			   atomic_read(&fs_info->async_delalloc_pages) <=
+			   async_pages);
+skip_async:
 		loops++;
 		if (wait_ordered && !trans) {
 			btrfs_wait_ordered_roots(fs_info, items, 0, (u64)-1);
@@ -595,8 +639,11 @@ static void flush_space(struct btrfs_fs_info *fs_info,
 		break;
 	case FLUSH_DELALLOC:
 	case FLUSH_DELALLOC_WAIT:
+	case FLUSH_DELALLOC_FULL:
+		if (state == FLUSH_DELALLOC_FULL)
+			num_bytes = U64_MAX;
 		shrink_delalloc(fs_info, space_info, num_bytes,
-				state == FLUSH_DELALLOC_WAIT, for_preempt);
+				state != FLUSH_DELALLOC, for_preempt);
 		break;
 	case FLUSH_DELAYED_REFS_NR:
 	case FLUSH_DELAYED_REFS:
@@ -686,7 +733,7 @@ static bool need_preemptive_reclaim(struct btrfs_fs_info *fs_info,
 {
 	u64 global_rsv_size = fs_info->global_block_rsv.reserved;
 	u64 ordered, delalloc;
-	u64 thresh = div_factor_fine(space_info->total_bytes, 98);
+	u64 thresh = div_factor_fine(space_info->total_bytes, 90);
 	u64 used;
 
 	/* If we're just plain full then async reclaim just slows us down. */
@@ -694,6 +741,20 @@ static bool need_preemptive_reclaim(struct btrfs_fs_info *fs_info,
 	     global_rsv_size) >= thresh)
 		return false;
 
+	used = space_info->bytes_may_use + space_info->bytes_pinned;
+
+	/* The total flushable belongs to the global rsv, don't flush. */
+	if (global_rsv_size >= used)
+		return false;
+
+	/*
+	 * 128MiB is 1/4 of the maximum global rsv size.  If we have less than
+	 * that devoted to other reservations then there's no sense in flushing,
+	 * we don't have a lot of things that need flushing.
+	 */
+	if (used - global_rsv_size <= SZ_128M)
+		return false;
+
 	/*
 	 * We have tickets queued, bail so we don't compete with the async
 	 * flushers.
@@ -824,6 +885,8 @@ static bool maybe_fail_all_tickets(struct btrfs_fs_info *fs_info,
 	struct reserve_ticket *ticket;
 	u64 tickets_id = space_info->tickets_id;
 
+	trace_btrfs_fail_all_tickets(fs_info, space_info);
+
 	if (btrfs_test_opt(fs_info, ENOSPC_DEBUG)) {
 		btrfs_info(fs_info, "cannot satisfy tickets, dumping space info");
 		__btrfs_dump_space_info(fs_info, space_info);
@@ -905,6 +968,14 @@ static void btrfs_async_reclaim_metadata_space(struct work_struct *work)
 		}
 
 		/*
+		 * We do not want to empty the system of delalloc unless we're
+		 * under heavy pressure, so allow one trip through the flushing
+		 * logic before we start doing a FLUSH_DELALLOC_FULL.
+		 */
+		if (flush_state == FLUSH_DELALLOC_FULL && !commit_cycles)
+			flush_state++;
+
+		/*
 		 * We don't want to force a chunk allocation until we've tried
 		 * pretty hard to reclaim space.  Think of the case where we
 		 * freed up a bunch of space and so have a lot of pinned space
@@ -1067,7 +1138,7 @@ static void btrfs_preempt_reclaim_metadata_space(struct work_struct *work)
  *   so if we now have space to allocate do the force chunk allocation.
  */
 static const enum btrfs_flush_state data_flush_states[] = {
-	FLUSH_DELALLOC_WAIT,
+	FLUSH_DELALLOC_FULL,
 	RUN_DELAYED_IPUTS,
 	COMMIT_TRANS,
 	ALLOC_CHUNK_FORCE,
@@ -1156,6 +1227,7 @@ static const enum btrfs_flush_state evict_flush_states[] = {
 	FLUSH_DELAYED_REFS,
 	FLUSH_DELALLOC,
 	FLUSH_DELALLOC_WAIT,
+	FLUSH_DELALLOC_FULL,
 	ALLOC_CHUNK,
 	COMMIT_TRANS,
 };
diff --git a/fs/btrfs/struct-funcs.c b/fs/btrfs/struct-funcs.c
index 8260f8bb3ff0..f429256f56db 100644
--- a/fs/btrfs/struct-funcs.c
+++ b/fs/btrfs/struct-funcs.c
@@ -73,7 +73,7 @@ u##bits btrfs_get_token_##bits(struct btrfs_map_token *token,		\
 	}								\
 	token->kaddr = page_address(token->eb->pages[idx]);		\
 	token->offset = idx << PAGE_SHIFT;				\
-	if (oip + size <= PAGE_SIZE)					\
+	if (INLINE_EXTENT_BUFFER_PAGES == 1 || oip + size <= PAGE_SIZE ) \
 		return get_unaligned_le##bits(token->kaddr + oip);	\
 									\
 	memcpy(lebytes, token->kaddr + oip, part);			\
@@ -94,7 +94,7 @@ u##bits btrfs_get_##bits(const struct extent_buffer *eb,		\
 	u8 lebytes[sizeof(u##bits)];					\
 									\
 	ASSERT(check_setget_bounds(eb, ptr, off, size));		\
-	if (oip + size <= PAGE_SIZE)					\
+	if (INLINE_EXTENT_BUFFER_PAGES == 1 || oip + size <= PAGE_SIZE)	\
 		return get_unaligned_le##bits(kaddr + oip);		\
 									\
 	memcpy(lebytes, kaddr + oip, part);				\
@@ -124,7 +124,7 @@ void btrfs_set_token_##bits(struct btrfs_map_token *token,		\
 	}								\
 	token->kaddr = page_address(token->eb->pages[idx]);		\
 	token->offset = idx << PAGE_SHIFT;				\
-	if (oip + size <= PAGE_SIZE) {					\
+	if (INLINE_EXTENT_BUFFER_PAGES == 1 || oip + size <= PAGE_SIZE) { \
 		put_unaligned_le##bits(val, token->kaddr + oip);	\
 		return;							\
 	}								\
@@ -146,7 +146,7 @@ void btrfs_set_##bits(const struct extent_buffer *eb, void *ptr,	\
 	u8 lebytes[sizeof(u##bits)];					\
 									\
 	ASSERT(check_setget_bounds(eb, ptr, off, size));		\
-	if (oip + size <= PAGE_SIZE) {					\
+	if (INLINE_EXTENT_BUFFER_PAGES == 1 || oip + size <= PAGE_SIZE) { \
 		put_unaligned_le##bits(val, kaddr + oip);		\
 		return;							\
 	}								\
diff --git a/fs/btrfs/subpage.c b/fs/btrfs/subpage.c
index 640bcd21bf28..cb10e56ee31e 100644
--- a/fs/btrfs/subpage.c
+++ b/fs/btrfs/subpage.c
@@ -435,8 +435,10 @@ void btrfs_subpage_clear_writeback(const struct btrfs_fs_info *fs_info,
 
 	spin_lock_irqsave(&subpage->lock, flags);
 	subpage->writeback_bitmap &= ~tmp;
-	if (subpage->writeback_bitmap == 0)
+	if (subpage->writeback_bitmap == 0) {
+		ASSERT(PageWriteback(page));
 		end_page_writeback(page);
+	}
 	spin_unlock_irqrestore(&subpage->lock, flags);
 }
 
@@ -559,3 +561,23 @@ IMPLEMENT_BTRFS_PAGE_OPS(writeback, set_page_writeback, end_page_writeback,
 			 PageWriteback);
 IMPLEMENT_BTRFS_PAGE_OPS(ordered, SetPageOrdered, ClearPageOrdered,
 			 PageOrdered);
+
+/*
+ * Make sure not only the page dirty bit is cleared, but also subpage dirty bit
+ * is cleared.
+ */
+void btrfs_page_assert_not_dirty(const struct btrfs_fs_info *fs_info,
+				 struct page *page)
+{
+	struct btrfs_subpage *subpage = (struct btrfs_subpage *)page->private;
+
+	if (!IS_ENABLED(CONFIG_BTRFS_ASSERT))
+		return;
+
+	ASSERT(!PageDirty(page));
+	if (fs_info->sectorsize == PAGE_SIZE)
+		return;
+
+	ASSERT(PagePrivate(page) && page->private);
+	ASSERT(subpage->dirty_bitmap == 0);
+}
diff --git a/fs/btrfs/subpage.h b/fs/btrfs/subpage.h
index 4d7aca85d915..0120948f37a1 100644
--- a/fs/btrfs/subpage.h
+++ b/fs/btrfs/subpage.h
@@ -126,4 +126,7 @@ DECLARE_BTRFS_SUBPAGE_OPS(ordered);
 bool btrfs_subpage_clear_and_test_dirty(const struct btrfs_fs_info *fs_info,
 		struct page *page, u64 start, u32 len);
 
+void btrfs_page_assert_not_dirty(const struct btrfs_fs_info *fs_info,
+				 struct page *page);
+
 #endif
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index d07b18b2b250..537d90bf5d84 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -1201,21 +1201,14 @@ char *btrfs_get_subvol_name_from_objectid(struct btrfs_fs_info *fs_info,
 		key.type = BTRFS_ROOT_BACKREF_KEY;
 		key.offset = (u64)-1;
 
-		ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+		ret = btrfs_search_backwards(root, &key, path);
 		if (ret < 0) {
 			goto err;
 		} else if (ret > 0) {
-			ret = btrfs_previous_item(root, path, subvol_objectid,
-						  BTRFS_ROOT_BACKREF_KEY);
-			if (ret < 0) {
-				goto err;
-			} else if (ret > 0) {
-				ret = -ENOENT;
-				goto err;
-			}
+			ret = -ENOENT;
+			goto err;
 		}
 
-		btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
 		subvol_objectid = key.offset;
 
 		root_ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
@@ -1248,21 +1241,14 @@ char *btrfs_get_subvol_name_from_objectid(struct btrfs_fs_info *fs_info,
 			key.type = BTRFS_INODE_REF_KEY;
 			key.offset = (u64)-1;
 
-			ret = btrfs_search_slot(NULL, fs_root, &key, path, 0, 0);
+			ret = btrfs_search_backwards(fs_root, &key, path);
 			if (ret < 0) {
 				goto err;
 			} else if (ret > 0) {
-				ret = btrfs_previous_item(fs_root, path, dirid,
-							  BTRFS_INODE_REF_KEY);
-				if (ret < 0) {
-					goto err;
-				} else if (ret > 0) {
-					ret = -ENOENT;
-					goto err;
-				}
+				ret = -ENOENT;
+				goto err;
 			}
 
-			btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
 			dirid = key.offset;
 
 			inode_ref = btrfs_item_ptr(path->nodes[0],
@@ -1353,6 +1339,9 @@ static int btrfs_fill_super(struct super_block *sb,
 	sb->s_op = &btrfs_super_ops;
 	sb->s_d_op = &btrfs_dentry_operations;
 	sb->s_export_op = &btrfs_export_ops;
+#ifdef CONFIG_FS_VERITY
+	sb->s_vop = &btrfs_verityops;
+#endif
 	sb->s_xattr = btrfs_xattr_handlers;
 	sb->s_time_gran = 1;
 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
@@ -2041,13 +2030,6 @@ static int btrfs_remount(struct super_block *sb, int *flags, char *data)
 			ret = -EINVAL;
 			goto restore;
 		}
-		if (fs_info->sectorsize < PAGE_SIZE) {
-			btrfs_warn(fs_info,
-	"read-write mount is not yet allowed for sectorsize %u page size %lu",
-				   fs_info->sectorsize, PAGE_SIZE);
-			ret = -EINVAL;
-			goto restore;
-		}
 
 		/*
 		 * NOTE: when remounting with a change that does writes, don't
@@ -2096,16 +2078,15 @@ restore:
 }
 
 /* Used to sort the devices by max_avail(descending sort) */
-static inline int btrfs_cmp_device_free_bytes(const void *dev_info1,
-				       const void *dev_info2)
+static int btrfs_cmp_device_free_bytes(const void *a, const void *b)
 {
-	if (((struct btrfs_device_info *)dev_info1)->max_avail >
-	    ((struct btrfs_device_info *)dev_info2)->max_avail)
+	const struct btrfs_device_info *dev_info1 = a;
+	const struct btrfs_device_info *dev_info2 = b;
+
+	if (dev_info1->max_avail > dev_info2->max_avail)
 		return -1;
-	else if (((struct btrfs_device_info *)dev_info1)->max_avail <
-		 ((struct btrfs_device_info *)dev_info2)->max_avail)
+	else if (dev_info1->max_avail < dev_info2->max_avail)
 		return 1;
-	else
 	return 0;
 }
 
@@ -2381,7 +2362,7 @@ static struct file_system_type btrfs_root_fs_type = {
 	.name		= "btrfs",
 	.mount		= btrfs_mount_root,
 	.kill_sb	= btrfs_kill_super,
-	.fs_flags	= FS_REQUIRES_DEV | FS_BINARY_MOUNTDATA,
+	.fs_flags	= FS_REQUIRES_DEV | FS_BINARY_MOUNTDATA | FS_ALLOW_IDMAP,
 };
 
 MODULE_ALIAS_FS("btrfs");
@@ -2572,6 +2553,11 @@ static void __init btrfs_print_mod_info(void)
 #else
 			", zoned=no"
 #endif
+#ifdef CONFIG_FS_VERITY
+			", fsverity=yes"
+#else
+			", fsverity=no"
+#endif
 			;
 	pr_info("Btrfs loaded, crc32c=%s%s\n", crc32c_impl(), options);
 }
diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
index 9d1d140118ff..25a6f587852b 100644
--- a/fs/btrfs/sysfs.c
+++ b/fs/btrfs/sysfs.c
@@ -22,6 +22,26 @@
 #include "block-group.h"
 #include "qgroup.h"
 
+/*
+ * Structure name                       Path
+ * --------------------------------------------------------------------------
+ * btrfs_supported_static_feature_attrs /sys/fs/btrfs/features
+ * btrfs_supported_feature_attrs	/sys/fs/btrfs/features and
+ *					/sys/fs/btrfs/<uuid>/features
+ * btrfs_attrs				/sys/fs/btrfs/<uuid>
+ * devid_attrs				/sys/fs/btrfs/<uuid>/devinfo/<devid>
+ * allocation_attrs			/sys/fs/btrfs/<uuid>/allocation
+ * qgroup_attrs				/sys/fs/btrfs/<uuid>/qgroups/<level>_<qgroupid>
+ * space_info_attrs			/sys/fs/btrfs/<uuid>/allocation/<bg-type>
+ * raid_attrs				/sys/fs/btrfs/<uuid>/allocation/<bg-type>/<bg-profile>
+ *
+ * When built with BTRFS_CONFIG_DEBUG:
+ *
+ * btrfs_debug_feature_attrs		/sys/fs/btrfs/debug
+ * btrfs_debug_mount_attrs		/sys/fs/btrfs/<uuid>/debug
+ * discard_debug_attrs			/sys/fs/btrfs/<uuid>/debug/discard
+ */
+
 struct btrfs_feature_attr {
 	struct kobj_attribute kobj_attr;
 	enum btrfs_feature_set feature_set;
@@ -267,7 +287,17 @@ BTRFS_FEAT_ATTR_INCOMPAT(raid1c34, RAID1C34);
 #ifdef CONFIG_BTRFS_DEBUG
 BTRFS_FEAT_ATTR_INCOMPAT(zoned, ZONED);
 #endif
+#ifdef CONFIG_FS_VERITY
+BTRFS_FEAT_ATTR_COMPAT_RO(verity, VERITY);
+#endif
 
+/*
+ * Features which depend on feature bits and may differ between each fs.
+ *
+ * /sys/fs/btrfs/features      - all available features implemeted by this version
+ * /sys/fs/btrfs/UUID/features - features of the fs which are enabled or
+ *                               can be changed on a mounted filesystem.
+ */
 static struct attribute *btrfs_supported_feature_attrs[] = {
 	BTRFS_FEAT_ATTR_PTR(mixed_backref),
 	BTRFS_FEAT_ATTR_PTR(default_subvol),
@@ -285,16 +315,12 @@ static struct attribute *btrfs_supported_feature_attrs[] = {
 #ifdef CONFIG_BTRFS_DEBUG
 	BTRFS_FEAT_ATTR_PTR(zoned),
 #endif
+#ifdef CONFIG_FS_VERITY
+	BTRFS_FEAT_ATTR_PTR(verity),
+#endif
 	NULL
 };
 
-/*
- * Features which depend on feature bits and may differ between each fs.
- *
- * /sys/fs/btrfs/features lists all available features of this kernel while
- * /sys/fs/btrfs/UUID/features shows features of the fs which are enabled or
- * can be changed online.
- */
 static const struct attribute_group btrfs_feature_attr_group = {
 	.name = "features",
 	.is_visible = btrfs_feature_visible,
@@ -366,6 +392,10 @@ static ssize_t supported_sectorsizes_show(struct kobject *kobj,
 {
 	ssize_t ret = 0;
 
+	/* 4K sector size is also supported with 64K page size */
+	if (PAGE_SIZE == SZ_64K)
+		ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%u ", SZ_4K);
+
 	/* Only sectorsize == PAGE_SIZE is now supported */
 	ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%lu\n", PAGE_SIZE);
 
@@ -374,6 +404,12 @@ static ssize_t supported_sectorsizes_show(struct kobject *kobj,
 BTRFS_ATTR(static_feature, supported_sectorsizes,
 	   supported_sectorsizes_show);
 
+/*
+ * Features which only depend on kernel version.
+ *
+ * These are listed in /sys/fs/btrfs/features along with
+ * btrfs_supported_feature_attrs.
+ */
 static struct attribute *btrfs_supported_static_feature_attrs[] = {
 	BTRFS_ATTR_PTR(static_feature, rmdir_subvol),
 	BTRFS_ATTR_PTR(static_feature, supported_checksums),
@@ -383,12 +419,6 @@ static struct attribute *btrfs_supported_static_feature_attrs[] = {
 	NULL
 };
 
-/*
- * Features which only depend on kernel version.
- *
- * These are listed in /sys/fs/btrfs/features along with
- * btrfs_feature_attr_group
- */
 static const struct attribute_group btrfs_static_feature_attr_group = {
 	.name = "features",
 	.attrs = btrfs_supported_static_feature_attrs,
@@ -547,6 +577,11 @@ static ssize_t btrfs_discard_max_discard_size_store(struct kobject *kobj,
 BTRFS_ATTR_RW(discard, max_discard_size, btrfs_discard_max_discard_size_show,
 	      btrfs_discard_max_discard_size_store);
 
+/*
+ * Per-filesystem debugging of discard (when mounted with discard=async).
+ *
+ * Path: /sys/fs/btrfs/<uuid>/debug/discard/
+ */
 static const struct attribute *discard_debug_attrs[] = {
 	BTRFS_ATTR_PTR(discard, discardable_bytes),
 	BTRFS_ATTR_PTR(discard, discardable_extents),
@@ -560,15 +595,19 @@ static const struct attribute *discard_debug_attrs[] = {
 };
 
 /*
- * Runtime debugging exported via sysfs
+ * Per-filesystem runtime debugging exported via sysfs.
  *
- * /sys/fs/btrfs/debug - applies to module or all filesystems
- * /sys/fs/btrfs/UUID  - applies only to the given filesystem
+ * Path: /sys/fs/btrfs/UUID/debug/
  */
 static const struct attribute *btrfs_debug_mount_attrs[] = {
 	NULL,
 };
 
+/*
+ * Runtime debugging exported via sysfs, applies to all mounted filesystems.
+ *
+ * Path: /sys/fs/btrfs/debug
+ */
 static struct attribute *btrfs_debug_feature_attrs[] = {
 	NULL
 };
@@ -637,6 +676,11 @@ static ssize_t raid_bytes_show(struct kobject *kobj,
 	return scnprintf(buf, PAGE_SIZE, "%llu\n", val);
 }
 
+/*
+ * Allocation information about block group profiles.
+ *
+ * Path: /sys/fs/btrfs/<uuid>/allocation/<bg-type>/<bg-profile>/
+ */
 static struct attribute *raid_attrs[] = {
 	BTRFS_ATTR_PTR(raid, total_bytes),
 	BTRFS_ATTR_PTR(raid, used_bytes),
@@ -676,6 +720,11 @@ SPACE_INFO_ATTR(bytes_zone_unusable);
 SPACE_INFO_ATTR(disk_used);
 SPACE_INFO_ATTR(disk_total);
 
+/*
+ * Allocation information about block group types.
+ *
+ * Path: /sys/fs/btrfs/<uuid>/allocation/<bg-type>/
+ */
 static struct attribute *space_info_attrs[] = {
 	BTRFS_ATTR_PTR(space_info, flags),
 	BTRFS_ATTR_PTR(space_info, total_bytes),
@@ -703,6 +752,11 @@ static struct kobj_type space_info_ktype = {
 	.default_groups = space_info_groups,
 };
 
+/*
+ * Allocation information about block groups.
+ *
+ * Path: /sys/fs/btrfs/<uuid>/allocation/
+ */
 static const struct attribute *allocation_attrs[] = {
 	BTRFS_ATTR_PTR(allocation, global_rsv_reserved),
 	BTRFS_ATTR_PTR(allocation, global_rsv_size),
@@ -974,7 +1028,8 @@ static ssize_t btrfs_bg_reclaim_threshold_show(struct kobject *kobj,
 	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 	ssize_t ret;
 
-	ret = scnprintf(buf, PAGE_SIZE, "%d\n", fs_info->bg_reclaim_threshold);
+	ret = scnprintf(buf, PAGE_SIZE, "%d\n",
+			READ_ONCE(fs_info->bg_reclaim_threshold));
 
 	return ret;
 }
@@ -991,16 +1046,21 @@ static ssize_t btrfs_bg_reclaim_threshold_store(struct kobject *kobj,
 	if (ret)
 		return ret;
 
-	if (thresh <= 50 || thresh > 100)
+	if (thresh != 0 && (thresh <= 50 || thresh > 100))
 		return -EINVAL;
 
-	fs_info->bg_reclaim_threshold = thresh;
+	WRITE_ONCE(fs_info->bg_reclaim_threshold, thresh);
 
 	return len;
 }
 BTRFS_ATTR_RW(, bg_reclaim_threshold, btrfs_bg_reclaim_threshold_show,
 	      btrfs_bg_reclaim_threshold_store);
 
+/*
+ * Per-filesystem information and stats.
+ *
+ * Path: /sys/fs/btrfs/<uuid>/
+ */
 static const struct attribute *btrfs_attrs[] = {
 	BTRFS_ATTR_PTR(, label),
 	BTRFS_ATTR_PTR(, nodesize),
@@ -1510,6 +1570,11 @@ static ssize_t btrfs_devinfo_error_stats_show(struct kobject *kobj,
 }
 BTRFS_ATTR(devid, error_stats, btrfs_devinfo_error_stats_show);
 
+/*
+ * Information about one device.
+ *
+ * Path: /sys/fs/btrfs/<uuid>/devinfo/<devid>/
+ */
 static struct attribute *devid_attrs[] = {
 	BTRFS_ATTR_PTR(devid, error_stats),
 	BTRFS_ATTR_PTR(devid, in_fs_metadata),
@@ -1799,6 +1864,11 @@ QGROUP_RSV_ATTR(data, BTRFS_QGROUP_RSV_DATA);
 QGROUP_RSV_ATTR(meta_pertrans, BTRFS_QGROUP_RSV_META_PERTRANS);
 QGROUP_RSV_ATTR(meta_prealloc, BTRFS_QGROUP_RSV_META_PREALLOC);
 
+/*
+ * Qgroup information.
+ *
+ * Path: /sys/fs/btrfs/<uuid>/qgroups/<level>_<qgroupid>/
+ */
 static struct attribute *qgroup_attrs[] = {
 	BTRFS_ATTR_PTR(qgroup, referenced),
 	BTRFS_ATTR_PTR(qgroup, exclusive),
diff --git a/fs/btrfs/tests/qgroup-tests.c b/fs/btrfs/tests/qgroup-tests.c
index 98b5aaba46f1..19ba7d5b7d8f 100644
--- a/fs/btrfs/tests/qgroup-tests.c
+++ b/fs/btrfs/tests/qgroup-tests.c
@@ -223,8 +223,7 @@ static int test_no_shared_qgroup(struct btrfs_root *root,
 	 * we can only call btrfs_qgroup_account_extent() directly to test
 	 * quota.
 	 */
-	ret = btrfs_find_all_roots(&trans, fs_info, nodesize, 0, &old_roots,
-			false, false);
+	ret = btrfs_find_all_roots(&trans, fs_info, nodesize, 0, &old_roots, false);
 	if (ret) {
 		ulist_free(old_roots);
 		test_err("couldn't find old roots: %d", ret);
@@ -236,8 +235,7 @@ static int test_no_shared_qgroup(struct btrfs_root *root,
 	if (ret)
 		return ret;
 
-	ret = btrfs_find_all_roots(&trans, fs_info, nodesize, 0, &new_roots,
-			false, false);
+	ret = btrfs_find_all_roots(&trans, fs_info, nodesize, 0, &new_roots, false);
 	if (ret) {
 		ulist_free(old_roots);
 		ulist_free(new_roots);
@@ -260,8 +258,7 @@ static int test_no_shared_qgroup(struct btrfs_root *root,
 	old_roots = NULL;
 	new_roots = NULL;
 
-	ret = btrfs_find_all_roots(&trans, fs_info, nodesize, 0, &old_roots,
-			false, false);
+	ret = btrfs_find_all_roots(&trans, fs_info, nodesize, 0, &old_roots, false);
 	if (ret) {
 		ulist_free(old_roots);
 		test_err("couldn't find old roots: %d", ret);
@@ -272,8 +269,7 @@ static int test_no_shared_qgroup(struct btrfs_root *root,
 	if (ret)
 		return -EINVAL;
 
-	ret = btrfs_find_all_roots(&trans, fs_info, nodesize, 0, &new_roots,
-			false, false);
+	ret = btrfs_find_all_roots(&trans, fs_info, nodesize, 0, &new_roots, false);
 	if (ret) {
 		ulist_free(old_roots);
 		ulist_free(new_roots);
@@ -324,8 +320,7 @@ static int test_multiple_refs(struct btrfs_root *root,
 		return ret;
 	}
 
-	ret = btrfs_find_all_roots(&trans, fs_info, nodesize, 0, &old_roots,
-			false, false);
+	ret = btrfs_find_all_roots(&trans, fs_info, nodesize, 0, &old_roots, false);
 	if (ret) {
 		ulist_free(old_roots);
 		test_err("couldn't find old roots: %d", ret);
@@ -337,8 +332,7 @@ static int test_multiple_refs(struct btrfs_root *root,
 	if (ret)
 		return ret;
 
-	ret = btrfs_find_all_roots(&trans, fs_info, nodesize, 0, &new_roots,
-			false, false);
+	ret = btrfs_find_all_roots(&trans, fs_info, nodesize, 0, &new_roots, false);
 	if (ret) {
 		ulist_free(old_roots);
 		ulist_free(new_roots);
@@ -359,8 +353,7 @@ static int test_multiple_refs(struct btrfs_root *root,
 		return -EINVAL;
 	}
 
-	ret = btrfs_find_all_roots(&trans, fs_info, nodesize, 0, &old_roots,
-			false, false);
+	ret = btrfs_find_all_roots(&trans, fs_info, nodesize, 0, &old_roots, false);
 	if (ret) {
 		ulist_free(old_roots);
 		test_err("couldn't find old roots: %d", ret);
@@ -372,8 +365,7 @@ static int test_multiple_refs(struct btrfs_root *root,
 	if (ret)
 		return ret;
 
-	ret = btrfs_find_all_roots(&trans, fs_info, nodesize, 0, &new_roots,
-			false, false);
+	ret = btrfs_find_all_roots(&trans, fs_info, nodesize, 0, &new_roots, false);
 	if (ret) {
 		ulist_free(old_roots);
 		ulist_free(new_roots);
@@ -400,8 +392,7 @@ static int test_multiple_refs(struct btrfs_root *root,
 		return -EINVAL;
 	}
 
-	ret = btrfs_find_all_roots(&trans, fs_info, nodesize, 0, &old_roots,
-			false, false);
+	ret = btrfs_find_all_roots(&trans, fs_info, nodesize, 0, &old_roots, false);
 	if (ret) {
 		ulist_free(old_roots);
 		test_err("couldn't find old roots: %d", ret);
@@ -413,8 +404,7 @@ static int test_multiple_refs(struct btrfs_root *root,
 	if (ret)
 		return ret;
 
-	ret = btrfs_find_all_roots(&trans, fs_info, nodesize, 0, &new_roots,
-			false, false);
+	ret = btrfs_find_all_roots(&trans, fs_info, nodesize, 0, &new_roots, false);
 	if (ret) {
 		ulist_free(old_roots);
 		ulist_free(new_roots);
diff --git a/fs/btrfs/tree-checker.c b/fs/btrfs/tree-checker.c
index a8b2e0d2c025..7733e8ac0a69 100644
--- a/fs/btrfs/tree-checker.c
+++ b/fs/btrfs/tree-checker.c
@@ -24,6 +24,7 @@
 #include "compression.h"
 #include "volumes.h"
 #include "misc.h"
+#include "btrfs_inode.h"
 
 /*
  * Error message should follow the following format:
@@ -873,13 +874,22 @@ int btrfs_check_chunk_valid(struct extent_buffer *leaf,
 		}
 	}
 
-	if (unlikely((type & BTRFS_BLOCK_GROUP_RAID10 && sub_stripes != 2) ||
-		     (type & BTRFS_BLOCK_GROUP_RAID1 && num_stripes != 2) ||
-		     (type & BTRFS_BLOCK_GROUP_RAID5 && num_stripes < 2) ||
-		     (type & BTRFS_BLOCK_GROUP_RAID6 && num_stripes < 3) ||
-		     (type & BTRFS_BLOCK_GROUP_DUP && num_stripes != 2) ||
+	if (unlikely((type & BTRFS_BLOCK_GROUP_RAID10 &&
+		      sub_stripes != btrfs_raid_array[BTRFS_RAID_RAID10].sub_stripes) ||
+		     (type & BTRFS_BLOCK_GROUP_RAID1 &&
+		      num_stripes != btrfs_raid_array[BTRFS_RAID_RAID1].devs_min) ||
+		     (type & BTRFS_BLOCK_GROUP_RAID1C3 &&
+		      num_stripes != btrfs_raid_array[BTRFS_RAID_RAID1C3].devs_min) ||
+		     (type & BTRFS_BLOCK_GROUP_RAID1C4 &&
+		      num_stripes != btrfs_raid_array[BTRFS_RAID_RAID1C4].devs_min) ||
+		     (type & BTRFS_BLOCK_GROUP_RAID5 &&
+		      num_stripes < btrfs_raid_array[BTRFS_RAID_RAID5].devs_min) ||
+		     (type & BTRFS_BLOCK_GROUP_RAID6 &&
+		      num_stripes < btrfs_raid_array[BTRFS_RAID_RAID6].devs_min) ||
+		     (type & BTRFS_BLOCK_GROUP_DUP &&
+		      num_stripes != btrfs_raid_array[BTRFS_RAID_DUP].dev_stripes) ||
 		     ((type & BTRFS_BLOCK_GROUP_PROFILE_MASK) == 0 &&
-		      num_stripes != 1))) {
+		      num_stripes != btrfs_raid_array[BTRFS_RAID_SINGLE].dev_stripes))) {
 		chunk_err(leaf, chunk, logical,
 			"invalid num_stripes:sub_stripes %u:%u for profile %llu",
 			num_stripes, sub_stripes,
@@ -999,6 +1009,8 @@ static int check_inode_item(struct extent_buffer *leaf,
 	u32 valid_mask = (S_IFMT | S_ISUID | S_ISGID | S_ISVTX | 0777);
 	u32 mode;
 	int ret;
+	u32 flags;
+	u32 ro_flags;
 
 	ret = check_inode_key(leaf, key, slot);
 	if (unlikely(ret < 0))
@@ -1054,11 +1066,17 @@ static int check_inode_item(struct extent_buffer *leaf,
 			btrfs_inode_nlink(leaf, iitem));
 		return -EUCLEAN;
 	}
-	if (unlikely(btrfs_inode_flags(leaf, iitem) & ~BTRFS_INODE_FLAG_MASK)) {
+	btrfs_inode_split_flags(btrfs_inode_flags(leaf, iitem), &flags, &ro_flags);
+	if (unlikely(flags & ~BTRFS_INODE_FLAG_MASK)) {
 		inode_item_err(leaf, slot,
-			       "unknown flags detected: 0x%llx",
-			       btrfs_inode_flags(leaf, iitem) &
-			       ~BTRFS_INODE_FLAG_MASK);
+			       "unknown incompat flags detected: 0x%x", flags);
+		return -EUCLEAN;
+	}
+	if (unlikely(!sb_rdonly(fs_info->sb) &&
+		     (ro_flags & ~BTRFS_INODE_RO_FLAG_MASK))) {
+		inode_item_err(leaf, slot,
+			"unknown ro-compat flags detected on writeable mount: 0x%x",
+			ro_flags);
 		return -EUCLEAN;
 	}
 	return 0;
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index e6430ac9bbe8..f7efc26aa82a 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -753,7 +753,9 @@ static noinline int replay_one_extent(struct btrfs_trans_handle *trans,
 			 */
 			ret = btrfs_lookup_data_extent(fs_info, ins.objectid,
 						ins.offset);
-			if (ret == 0) {
+			if (ret < 0) {
+				goto out;
+			} else if (ret == 0) {
 				btrfs_init_generic_ref(&ref,
 						BTRFS_ADD_DELAYED_REF,
 						ins.objectid, ins.offset, 0);
@@ -3039,8 +3041,6 @@ static inline void btrfs_remove_all_log_ctxs(struct btrfs_root *root,
 		list_del_init(&ctx->list);
 		ctx->log_ret = error;
 	}
-
-	INIT_LIST_HEAD(&root->log_ctxs[index]);
 }
 
 /*
@@ -3328,10 +3328,16 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans,
 		goto out_wake_log_root;
 	}
 
-	mutex_lock(&root->log_mutex);
-	if (root->last_log_commit < log_transid)
-		root->last_log_commit = log_transid;
-	mutex_unlock(&root->log_mutex);
+	/*
+	 * We know there can only be one task here, since we have not yet set
+	 * root->log_commit[index1] to 0 and any task attempting to sync the
+	 * log must wait for the previous log transaction to commit if it's
+	 * still in progress or wait for the current log transaction commit if
+	 * someone else already started it. We use <= and not < because the
+	 * first log transaction has an ID of 0.
+	 */
+	ASSERT(root->last_log_commit <= log_transid);
+	root->last_log_commit = log_transid;
 
 out_wake_log_root:
 	mutex_lock(&log_root_tree->log_mutex);
@@ -3417,14 +3423,10 @@ int btrfs_free_log_root_tree(struct btrfs_trans_handle *trans,
 }
 
 /*
- * Check if an inode was logged in the current transaction. We can't always rely
- * on an inode's logged_trans value, because it's an in-memory only field and
- * therefore not persisted. This means that its value is lost if the inode gets
- * evicted and loaded again from disk (in which case it has a value of 0, and
- * certainly it is smaller then any possible transaction ID), when that happens
- * the full_sync flag is set in the inode's runtime flags, so on that case we
- * assume eviction happened and ignore the logged_trans value, assuming the
- * worst case, that the inode was logged before in the current transaction.
+ * Check if an inode was logged in the current transaction. This may often
+ * return some false positives, because logged_trans is an in memory only field,
+ * not persisted anywhere. This is meant to be used in contexts where a false
+ * positive has no functional consequences.
  */
 static bool inode_logged(struct btrfs_trans_handle *trans,
 			 struct btrfs_inode *inode)
@@ -3432,8 +3434,17 @@ static bool inode_logged(struct btrfs_trans_handle *trans,
 	if (inode->logged_trans == trans->transid)
 		return true;
 
-	if (inode->last_trans == trans->transid &&
-	    test_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags) &&
+	/*
+	 * The inode's logged_trans is always 0 when we load it (because it is
+	 * not persisted in the inode item or elsewhere). So if it is 0, the
+	 * inode was last modified in the current transaction then the inode may
+	 * have been logged before in the current transaction, then evicted and
+	 * loaded again in the current transaction - or may have never been logged
+	 * in the current transaction, but since we can not be sure, we have to
+	 * assume it was, otherwise our callers can leave an inconsistent log.
+	 */
+	if (inode->logged_trans == 0 &&
+	    inode->last_trans == trans->transid &&
 	    !test_bit(BTRFS_FS_LOG_RECOVERING, &trans->fs_info->flags))
 		return true;
 
@@ -3913,6 +3924,7 @@ static void fill_inode_item(struct btrfs_trans_handle *trans,
 			    u64 logged_isize)
 {
 	struct btrfs_map_token token;
+	u64 flags;
 
 	btrfs_init_map_token(&token, leaf);
 
@@ -3962,20 +3974,49 @@ static void fill_inode_item(struct btrfs_trans_handle *trans,
 	btrfs_set_token_inode_sequence(&token, item, inode_peek_iversion(inode));
 	btrfs_set_token_inode_transid(&token, item, trans->transid);
 	btrfs_set_token_inode_rdev(&token, item, inode->i_rdev);
-	btrfs_set_token_inode_flags(&token, item, BTRFS_I(inode)->flags);
+	flags = btrfs_inode_combine_flags(BTRFS_I(inode)->flags,
+					  BTRFS_I(inode)->ro_flags);
+	btrfs_set_token_inode_flags(&token, item, flags);
 	btrfs_set_token_inode_block_group(&token, item, 0);
 }
 
 static int log_inode_item(struct btrfs_trans_handle *trans,
 			  struct btrfs_root *log, struct btrfs_path *path,
-			  struct btrfs_inode *inode)
+			  struct btrfs_inode *inode, bool inode_item_dropped)
 {
 	struct btrfs_inode_item *inode_item;
 	int ret;
 
-	ret = btrfs_insert_empty_item(trans, log, path,
-				      &inode->location, sizeof(*inode_item));
-	if (ret && ret != -EEXIST)
+	/*
+	 * If we are doing a fast fsync and the inode was logged before in the
+	 * current transaction, then we know the inode was previously logged and
+	 * it exists in the log tree. For performance reasons, in this case use
+	 * btrfs_search_slot() directly with ins_len set to 0 so that we never
+	 * attempt a write lock on the leaf's parent, which adds unnecessary lock
+	 * contention in case there are concurrent fsyncs for other inodes of the
+	 * same subvolume. Using btrfs_insert_empty_item() when the inode item
+	 * already exists can also result in unnecessarily splitting a leaf.
+	 */
+	if (!inode_item_dropped && inode->logged_trans == trans->transid) {
+		ret = btrfs_search_slot(trans, log, &inode->location, path, 0, 1);
+		ASSERT(ret <= 0);
+		if (ret > 0)
+			ret = -ENOENT;
+	} else {
+		/*
+		 * This means it is the first fsync in the current transaction,
+		 * so the inode item is not in the log and we need to insert it.
+		 * We can never get -EEXIST because we are only called for a fast
+		 * fsync and in case an inode eviction happens after the inode was
+		 * logged before in the current transaction, when we load again
+		 * the inode, we set BTRFS_INODE_NEEDS_FULL_SYNC on its runtime
+		 * flags and set ->logged_trans to 0.
+		 */
+		ret = btrfs_insert_empty_item(trans, log, path, &inode->location,
+					      sizeof(*inode_item));
+		ASSERT(ret != -EEXIST);
+	}
+	if (ret)
 		return ret;
 	inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
 				    struct btrfs_inode_item);
@@ -4160,7 +4201,7 @@ static noinline int copy_items(struct btrfs_trans_handle *trans,
 static int extent_cmp(void *priv, const struct list_head *a,
 		      const struct list_head *b)
 {
-	struct extent_map *em1, *em2;
+	const struct extent_map *em1, *em2;
 
 	em1 = list_entry(a, struct extent_map, list);
 	em2 = list_entry(b, struct extent_map, list);
@@ -5053,8 +5094,8 @@ static int log_conflicting_inodes(struct btrfs_trans_handle *trans,
 		/*
 		 * Check the inode's logged_trans only instead of
 		 * btrfs_inode_in_log(). This is because the last_log_commit of
-		 * the inode is not updated when we only log that it exists and
-		 * it has the full sync bit set (see btrfs_log_inode()).
+		 * the inode is not updated when we only log that it exists (see
+		 * btrfs_log_inode()).
 		 */
 		if (BTRFS_I(inode)->logged_trans == trans->transid) {
 			spin_unlock(&BTRFS_I(inode)->lock);
@@ -5299,6 +5340,7 @@ static int btrfs_log_inode(struct btrfs_trans_handle *trans,
 	bool need_log_inode_item = true;
 	bool xattrs_logged = false;
 	bool recursive_logging = false;
+	bool inode_item_dropped = true;
 
 	path = btrfs_alloc_path();
 	if (!path)
@@ -5433,6 +5475,7 @@ static int btrfs_log_inode(struct btrfs_trans_handle *trans,
 		} else {
 			if (inode_only == LOG_INODE_ALL)
 				fast_search = true;
+			inode_item_dropped = false;
 			goto log_extents;
 		}
 
@@ -5466,7 +5509,7 @@ log_extents:
 	btrfs_release_path(path);
 	btrfs_release_path(dst_path);
 	if (need_log_inode_item) {
-		err = log_inode_item(trans, log, dst_path, inode);
+		err = log_inode_item(trans, log, dst_path, inode, inode_item_dropped);
 		if (err)
 			goto out_unlock;
 		/*
@@ -5573,6 +5616,13 @@ static bool need_log_inode(struct btrfs_trans_handle *trans,
 			   struct btrfs_inode *inode)
 {
 	/*
+	 * If a directory was not modified, no dentries added or removed, we can
+	 * and should avoid logging it.
+	 */
+	if (S_ISDIR(inode->vfs_inode.i_mode) && inode->last_trans < trans->transid)
+		return false;
+
+	/*
 	 * If this inode does not have new/updated/deleted xattrs since the last
 	 * time it was logged and is flagged as logged in the current transaction,
 	 * we can skip logging it. As for new/deleted names, those are updated in
diff --git a/fs/btrfs/verity.c b/fs/btrfs/verity.c
new file mode 100644
index 000000000000..28d443d3ef93
--- /dev/null
+++ b/fs/btrfs/verity.c
@@ -0,0 +1,811 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/init.h>
+#include <linux/fs.h>
+#include <linux/slab.h>
+#include <linux/rwsem.h>
+#include <linux/xattr.h>
+#include <linux/security.h>
+#include <linux/posix_acl_xattr.h>
+#include <linux/iversion.h>
+#include <linux/fsverity.h>
+#include <linux/sched/mm.h>
+#include "ctree.h"
+#include "btrfs_inode.h"
+#include "transaction.h"
+#include "disk-io.h"
+#include "locking.h"
+
+/*
+ * Implementation of the interface defined in struct fsverity_operations.
+ *
+ * The main question is how and where to store the verity descriptor and the
+ * Merkle tree. We store both in dedicated btree items in the filesystem tree,
+ * together with the rest of the inode metadata. This means we'll need to do
+ * extra work to encrypt them once encryption is supported in btrfs, but btrfs
+ * has a lot of careful code around i_size and it seems better to make a new key
+ * type than try and adjust all of our expectations for i_size.
+ *
+ * Note that this differs from the implementation in ext4 and f2fs, where
+ * this data is stored as if it were in the file, but past EOF. However, btrfs
+ * does not have a widespread mechanism for caching opaque metadata pages, so we
+ * do pretend that the Merkle tree pages themselves are past EOF for the
+ * purposes of caching them (as opposed to creating a virtual inode).
+ *
+ * fs verity items are stored under two different key types on disk.
+ * The descriptor items:
+ * [ inode objectid, BTRFS_VERITY_DESC_ITEM_KEY, offset ]
+ *
+ * At offset 0, we store a btrfs_verity_descriptor_item which tracks the
+ * size of the descriptor item and some extra data for encryption.
+ * Starting at offset 1, these hold the generic fs verity descriptor.
+ * The latter are opaque to btrfs, we just read and write them as a blob for
+ * the higher level verity code.  The most common descriptor size is 256 bytes.
+ *
+ * The merkle tree items:
+ * [ inode objectid, BTRFS_VERITY_MERKLE_ITEM_KEY, offset ]
+ *
+ * These also start at offset 0, and correspond to the merkle tree bytes.
+ * So when fsverity asks for page 0 of the merkle tree, we pull up one page
+ * starting at offset 0 for this key type.  These are also opaque to btrfs,
+ * we're blindly storing whatever fsverity sends down.
+ *
+ * Another important consideration is the fact that the Merkle tree data scales
+ * linearly with the size of the file (with 4K pages/blocks and SHA-256, it's
+ * ~1/127th the size) so for large files, writing the tree can be a lengthy
+ * operation. For that reason, we guard the whole enable verity operation
+ * (between begin_enable_verity and end_enable_verity) with an orphan item.
+ * Again, because the data can be pretty large, it's quite possible that we
+ * could run out of space writing it, so we try our best to handle errors by
+ * stopping and rolling back rather than aborting the victim transaction.
+ */
+
+#define MERKLE_START_ALIGN			65536
+
+/*
+ * Compute the logical file offset where we cache the Merkle tree.
+ *
+ * @inode:  inode of the verity file
+ *
+ * For the purposes of caching the Merkle tree pages, as required by
+ * fs-verity, it is convenient to do size computations in terms of a file
+ * offset, rather than in terms of page indices.
+ *
+ * Use 64K to be sure it's past the last page in the file, even with 64K pages.
+ * That rounding operation itself can overflow loff_t, so we do it in u64 and
+ * check.
+ *
+ * Returns the file offset on success, negative error code on failure.
+ */
+static loff_t merkle_file_pos(const struct inode *inode)
+{
+	u64 sz = inode->i_size;
+	u64 rounded = round_up(sz, MERKLE_START_ALIGN);
+
+	if (rounded > inode->i_sb->s_maxbytes)
+		return -EFBIG;
+
+	return rounded;
+}
+
+/*
+ * Drop all the items for this inode with this key_type.
+ *
+ * @inode:     inode to drop items for
+ * @key_type:  type of items to drop (BTRFS_VERITY_DESC_ITEM or
+ *             BTRFS_VERITY_MERKLE_ITEM)
+ *
+ * Before doing a verity enable we cleanup any existing verity items.
+ * This is also used to clean up if a verity enable failed half way through.
+ *
+ * Returns number of dropped items on success, negative error code on failure.
+ */
+static int drop_verity_items(struct btrfs_inode *inode, u8 key_type)
+{
+	struct btrfs_trans_handle *trans;
+	struct btrfs_root *root = inode->root;
+	struct btrfs_path *path;
+	struct btrfs_key key;
+	int count = 0;
+	int ret;
+
+	path = btrfs_alloc_path();
+	if (!path)
+		return -ENOMEM;
+
+	while (1) {
+		/* 1 for the item being dropped */
+		trans = btrfs_start_transaction(root, 1);
+		if (IS_ERR(trans)) {
+			ret = PTR_ERR(trans);
+			goto out;
+		}
+
+		/*
+		 * Walk backwards through all the items until we find one that
+		 * isn't from our key type or objectid
+		 */
+		key.objectid = btrfs_ino(inode);
+		key.type = key_type;
+		key.offset = (u64)-1;
+
+		ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
+		if (ret > 0) {
+			ret = 0;
+			/* No more keys of this type, we're done */
+			if (path->slots[0] == 0)
+				break;
+			path->slots[0]--;
+		} else if (ret < 0) {
+			btrfs_end_transaction(trans);
+			goto out;
+		}
+
+		btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
+
+		/* No more keys of this type, we're done */
+		if (key.objectid != btrfs_ino(inode) || key.type != key_type)
+			break;
+
+		/*
+		 * This shouldn't be a performance sensitive function because
+		 * it's not used as part of truncate.  If it ever becomes
+		 * perf sensitive, change this to walk forward and bulk delete
+		 * items
+		 */
+		ret = btrfs_del_items(trans, root, path, path->slots[0], 1);
+		if (ret) {
+			btrfs_end_transaction(trans);
+			goto out;
+		}
+		count++;
+		btrfs_release_path(path);
+		btrfs_end_transaction(trans);
+	}
+	ret = count;
+	btrfs_end_transaction(trans);
+out:
+	btrfs_free_path(path);
+	return ret;
+}
+
+/*
+ * Drop all verity items
+ *
+ * @inode:  inode to drop verity items for
+ *
+ * In most contexts where we are dropping verity items, we want to do it for all
+ * the types of verity items, not a particular one.
+ *
+ * Returns: 0 on success, negative error code on failure.
+ */
+int btrfs_drop_verity_items(struct btrfs_inode *inode)
+{
+	int ret;
+
+	ret = drop_verity_items(inode, BTRFS_VERITY_DESC_ITEM_KEY);
+	if (ret < 0)
+		return ret;
+	ret = drop_verity_items(inode, BTRFS_VERITY_MERKLE_ITEM_KEY);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+/*
+ * Insert and write inode items with a given key type and offset.
+ *
+ * @inode:     inode to insert for
+ * @key_type:  key type to insert
+ * @offset:    item offset to insert at
+ * @src:       source data to write
+ * @len:       length of source data to write
+ *
+ * Write len bytes from src into items of up to 2K length.
+ * The inserted items will have key (ino, key_type, offset + off) where off is
+ * consecutively increasing from 0 up to the last item ending at offset + len.
+ *
+ * Returns 0 on success and a negative error code on failure.
+ */
+static int write_key_bytes(struct btrfs_inode *inode, u8 key_type, u64 offset,
+			   const char *src, u64 len)
+{
+	struct btrfs_trans_handle *trans;
+	struct btrfs_path *path;
+	struct btrfs_root *root = inode->root;
+	struct extent_buffer *leaf;
+	struct btrfs_key key;
+	unsigned long copy_bytes;
+	unsigned long src_offset = 0;
+	void *data;
+	int ret = 0;
+
+	path = btrfs_alloc_path();
+	if (!path)
+		return -ENOMEM;
+
+	while (len > 0) {
+		/* 1 for the new item being inserted */
+		trans = btrfs_start_transaction(root, 1);
+		if (IS_ERR(trans)) {
+			ret = PTR_ERR(trans);
+			break;
+		}
+
+		key.objectid = btrfs_ino(inode);
+		key.type = key_type;
+		key.offset = offset;
+
+		/*
+		 * Insert 2K at a time mostly to be friendly for smaller leaf
+		 * size filesystems
+		 */
+		copy_bytes = min_t(u64, len, 2048);
+
+		ret = btrfs_insert_empty_item(trans, root, path, &key, copy_bytes);
+		if (ret) {
+			btrfs_end_transaction(trans);
+			break;
+		}
+
+		leaf = path->nodes[0];
+
+		data = btrfs_item_ptr(leaf, path->slots[0], void);
+		write_extent_buffer(leaf, src + src_offset,
+				    (unsigned long)data, copy_bytes);
+		offset += copy_bytes;
+		src_offset += copy_bytes;
+		len -= copy_bytes;
+
+		btrfs_release_path(path);
+		btrfs_end_transaction(trans);
+	}
+
+	btrfs_free_path(path);
+	return ret;
+}
+
+/*
+ * Read inode items of the given key type and offset from the btree.
+ *
+ * @inode:      inode to read items of
+ * @key_type:   key type to read
+ * @offset:     item offset to read from
+ * @dest:       Buffer to read into. This parameter has slightly tricky
+ *              semantics.  If it is NULL, the function will not do any copying
+ *              and will just return the size of all the items up to len bytes.
+ *              If dest_page is passed, then the function will kmap_local the
+ *              page and ignore dest, but it must still be non-NULL to avoid the
+ *              counting-only behavior.
+ * @len:        length in bytes to read
+ * @dest_page:  copy into this page instead of the dest buffer
+ *
+ * Helper function to read items from the btree.  This returns the number of
+ * bytes read or < 0 for errors.  We can return short reads if the items don't
+ * exist on disk or aren't big enough to fill the desired length.  Supports
+ * reading into a provided buffer (dest) or into the page cache
+ *
+ * Returns number of bytes read or a negative error code on failure.
+ */
+static int read_key_bytes(struct btrfs_inode *inode, u8 key_type, u64 offset,
+			  char *dest, u64 len, struct page *dest_page)
+{
+	struct btrfs_path *path;
+	struct btrfs_root *root = inode->root;
+	struct extent_buffer *leaf;
+	struct btrfs_key key;
+	u64 item_end;
+	u64 copy_end;
+	int copied = 0;
+	u32 copy_offset;
+	unsigned long copy_bytes;
+	unsigned long dest_offset = 0;
+	void *data;
+	char *kaddr = dest;
+	int ret;
+
+	path = btrfs_alloc_path();
+	if (!path)
+		return -ENOMEM;
+
+	if (dest_page)
+		path->reada = READA_FORWARD;
+
+	key.objectid = btrfs_ino(inode);
+	key.type = key_type;
+	key.offset = offset;
+
+	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+	if (ret < 0) {
+		goto out;
+	} else if (ret > 0) {
+		ret = 0;
+		if (path->slots[0] == 0)
+			goto out;
+		path->slots[0]--;
+	}
+
+	while (len > 0) {
+		leaf = path->nodes[0];
+		btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
+
+		if (key.objectid != btrfs_ino(inode) || key.type != key_type)
+			break;
+
+		item_end = btrfs_item_size_nr(leaf, path->slots[0]) + key.offset;
+
+		if (copied > 0) {
+			/*
+			 * Once we've copied something, we want all of the items
+			 * to be sequential
+			 */
+			if (key.offset != offset)
+				break;
+		} else {
+			/*
+			 * Our initial offset might be in the middle of an
+			 * item.  Make sure it all makes sense.
+			 */
+			if (key.offset > offset)
+				break;
+			if (item_end <= offset)
+				break;
+		}
+
+		/* desc = NULL to just sum all the item lengths */
+		if (!dest)
+			copy_end = item_end;
+		else
+			copy_end = min(offset + len, item_end);
+
+		/* Number of bytes in this item we want to copy */
+		copy_bytes = copy_end - offset;
+
+		/* Offset from the start of item for copying */
+		copy_offset = offset - key.offset;
+
+		if (dest) {
+			if (dest_page)
+				kaddr = kmap_local_page(dest_page);
+
+			data = btrfs_item_ptr(leaf, path->slots[0], void);
+			read_extent_buffer(leaf, kaddr + dest_offset,
+					   (unsigned long)data + copy_offset,
+					   copy_bytes);
+
+			if (dest_page)
+				kunmap_local(kaddr);
+		}
+
+		offset += copy_bytes;
+		dest_offset += copy_bytes;
+		len -= copy_bytes;
+		copied += copy_bytes;
+
+		path->slots[0]++;
+		if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
+			/*
+			 * We've reached the last slot in this leaf and we need
+			 * to go to the next leaf.
+			 */
+			ret = btrfs_next_leaf(root, path);
+			if (ret < 0) {
+				break;
+			} else if (ret > 0) {
+				ret = 0;
+				break;
+			}
+		}
+	}
+out:
+	btrfs_free_path(path);
+	if (!ret)
+		ret = copied;
+	return ret;
+}
+
+/*
+ * Delete an fsverity orphan
+ *
+ * @trans:  transaction to do the delete in
+ * @inode:  inode to orphan
+ *
+ * Capture verity orphan specific logic that is repeated in the couple places
+ * we delete verity orphans. Specifically, handling ENOENT and ignoring inodes
+ * with 0 links.
+ *
+ * Returns zero on success or a negative error code on failure.
+ */
+static int del_orphan(struct btrfs_trans_handle *trans, struct btrfs_inode *inode)
+{
+	struct btrfs_root *root = inode->root;
+	int ret;
+
+	/*
+	 * If the inode has no links, it is either already unlinked, or was
+	 * created with O_TMPFILE. In either case, it should have an orphan from
+	 * that other operation. Rather than reference count the orphans, we
+	 * simply ignore them here, because we only invoke the verity path in
+	 * the orphan logic when i_nlink is 1.
+	 */
+	if (!inode->vfs_inode.i_nlink)
+		return 0;
+
+	ret = btrfs_del_orphan_item(trans, root, btrfs_ino(inode));
+	if (ret == -ENOENT)
+		ret = 0;
+	return ret;
+}
+
+/*
+ * Rollback in-progress verity if we encounter an error.
+ *
+ * @inode:  inode verity had an error for
+ *
+ * We try to handle recoverable errors while enabling verity by rolling it back
+ * and just failing the operation, rather than having an fs level error no
+ * matter what. However, any error in rollback is unrecoverable.
+ *
+ * Returns 0 on success, negative error code on failure.
+ */
+static int rollback_verity(struct btrfs_inode *inode)
+{
+	struct btrfs_trans_handle *trans;
+	struct btrfs_root *root = inode->root;
+	int ret;
+
+	ASSERT(inode_is_locked(&inode->vfs_inode));
+	truncate_inode_pages(inode->vfs_inode.i_mapping, inode->vfs_inode.i_size);
+	clear_bit(BTRFS_INODE_VERITY_IN_PROGRESS, &inode->runtime_flags);
+	ret = btrfs_drop_verity_items(inode);
+	if (ret) {
+		btrfs_handle_fs_error(root->fs_info, ret,
+				"failed to drop verity items in rollback %llu",
+				(u64)inode->vfs_inode.i_ino);
+		goto out;
+	}
+
+	/*
+	 * 1 for updating the inode flag
+	 * 1 for deleting the orphan
+	 */
+	trans = btrfs_start_transaction(root, 2);
+	if (IS_ERR(trans)) {
+		ret = PTR_ERR(trans);
+		btrfs_handle_fs_error(root->fs_info, ret,
+			"failed to start transaction in verity rollback %llu",
+			(u64)inode->vfs_inode.i_ino);
+		goto out;
+	}
+	inode->ro_flags &= ~BTRFS_INODE_RO_VERITY;
+	btrfs_sync_inode_flags_to_i_flags(&inode->vfs_inode);
+	ret = btrfs_update_inode(trans, root, inode);
+	if (ret) {
+		btrfs_abort_transaction(trans, ret);
+		goto out;
+	}
+	ret = del_orphan(trans, inode);
+	if (ret) {
+		btrfs_abort_transaction(trans, ret);
+		goto out;
+	}
+	btrfs_end_transaction(trans);
+out:
+	return ret;
+}
+
+/*
+ * Finalize making the file a valid verity file
+ *
+ * @inode:      inode to be marked as verity
+ * @desc:       contents of the verity descriptor to write (not NULL)
+ * @desc_size:  size of the verity descriptor
+ *
+ * Do the actual work of finalizing verity after successfully writing the Merkle
+ * tree:
+ *
+ * - write out the descriptor items
+ * - mark the inode with the verity flag
+ * - delete the orphan item
+ * - mark the ro compat bit
+ * - clear the in progress bit
+ *
+ * Returns 0 on success, negative error code on failure.
+ */
+static int finish_verity(struct btrfs_inode *inode, const void *desc,
+			 size_t desc_size)
+{
+	struct btrfs_trans_handle *trans = NULL;
+	struct btrfs_root *root = inode->root;
+	struct btrfs_verity_descriptor_item item;
+	int ret;
+
+	/* Write out the descriptor item */
+	memset(&item, 0, sizeof(item));
+	btrfs_set_stack_verity_descriptor_size(&item, desc_size);
+	ret = write_key_bytes(inode, BTRFS_VERITY_DESC_ITEM_KEY, 0,
+			      (const char *)&item, sizeof(item));
+	if (ret)
+		goto out;
+
+	/* Write out the descriptor itself */
+	ret = write_key_bytes(inode, BTRFS_VERITY_DESC_ITEM_KEY, 1,
+			      desc, desc_size);
+	if (ret)
+		goto out;
+
+	/*
+	 * 1 for updating the inode flag
+	 * 1 for deleting the orphan
+	 */
+	trans = btrfs_start_transaction(root, 2);
+	if (IS_ERR(trans)) {
+		ret = PTR_ERR(trans);
+		goto out;
+	}
+	inode->ro_flags |= BTRFS_INODE_RO_VERITY;
+	btrfs_sync_inode_flags_to_i_flags(&inode->vfs_inode);
+	ret = btrfs_update_inode(trans, root, inode);
+	if (ret)
+		goto end_trans;
+	ret = del_orphan(trans, inode);
+	if (ret)
+		goto end_trans;
+	clear_bit(BTRFS_INODE_VERITY_IN_PROGRESS, &inode->runtime_flags);
+	btrfs_set_fs_compat_ro(root->fs_info, VERITY);
+end_trans:
+	btrfs_end_transaction(trans);
+out:
+	return ret;
+
+}
+
+/*
+ * fsverity op that begins enabling verity.
+ *
+ * @filp:  file to enable verity on
+ *
+ * Begin enabling fsverity for the file. We drop any existing verity items, add
+ * an orphan and set the in progress bit.
+ *
+ * Returns 0 on success, negative error code on failure.
+ */
+static int btrfs_begin_enable_verity(struct file *filp)
+{
+	struct btrfs_inode *inode = BTRFS_I(file_inode(filp));
+	struct btrfs_root *root = inode->root;
+	struct btrfs_trans_handle *trans;
+	int ret;
+
+	ASSERT(inode_is_locked(file_inode(filp)));
+
+	if (test_bit(BTRFS_INODE_VERITY_IN_PROGRESS, &inode->runtime_flags))
+		return -EBUSY;
+
+	/*
+	 * This should almost never do anything, but theoretically, it's
+	 * possible that we failed to enable verity on a file, then were
+	 * interrupted or failed while rolling back, failed to cleanup the
+	 * orphan, and finally attempt to enable verity again.
+	 */
+	ret = btrfs_drop_verity_items(inode);
+	if (ret)
+		return ret;
+
+	/* 1 for the orphan item */
+	trans = btrfs_start_transaction(root, 1);
+	if (IS_ERR(trans))
+		return PTR_ERR(trans);
+
+	ret = btrfs_orphan_add(trans, inode);
+	if (!ret)
+		set_bit(BTRFS_INODE_VERITY_IN_PROGRESS, &inode->runtime_flags);
+	btrfs_end_transaction(trans);
+
+	return 0;
+}
+
+/*
+ * fsverity op that ends enabling verity.
+ *
+ * @filp:              file we are finishing enabling verity on
+ * @desc:              verity descriptor to write out (NULL in error conditions)
+ * @desc_size:         size of the verity descriptor (variable with signatures)
+ * @merkle_tree_size:  size of the merkle tree in bytes
+ *
+ * If desc is null, then VFS is signaling an error occurred during verity
+ * enable, and we should try to rollback. Otherwise, attempt to finish verity.
+ *
+ * Returns 0 on success, negative error code on error.
+ */
+static int btrfs_end_enable_verity(struct file *filp, const void *desc,
+				   size_t desc_size, u64 merkle_tree_size)
+{
+	struct btrfs_inode *inode = BTRFS_I(file_inode(filp));
+	int ret = 0;
+	int rollback_ret;
+
+	ASSERT(inode_is_locked(file_inode(filp)));
+
+	if (desc == NULL)
+		goto rollback;
+
+	ret = finish_verity(inode, desc, desc_size);
+	if (ret)
+		goto rollback;
+	return ret;
+
+rollback:
+	rollback_ret = rollback_verity(inode);
+	if (rollback_ret)
+		btrfs_err(inode->root->fs_info,
+			  "failed to rollback verity items: %d", rollback_ret);
+	return ret;
+}
+
+/*
+ * fsverity op that gets the struct fsverity_descriptor.
+ *
+ * @inode:     inode to get the descriptor of
+ * @buf:       output buffer for the descriptor contents
+ * @buf_size:  size of the output buffer. 0 to query the size
+ *
+ * fsverity does a two pass setup for reading the descriptor, in the first pass
+ * it calls with buf_size = 0 to query the size of the descriptor, and then in
+ * the second pass it actually reads the descriptor off disk.
+ *
+ * Returns the size on success or a negative error code on failure.
+ */
+static int btrfs_get_verity_descriptor(struct inode *inode, void *buf,
+				       size_t buf_size)
+{
+	u64 true_size;
+	int ret = 0;
+	struct btrfs_verity_descriptor_item item;
+
+	memset(&item, 0, sizeof(item));
+	ret = read_key_bytes(BTRFS_I(inode), BTRFS_VERITY_DESC_ITEM_KEY, 0,
+			     (char *)&item, sizeof(item), NULL);
+	if (ret < 0)
+		return ret;
+
+	if (item.reserved[0] != 0 || item.reserved[1] != 0)
+		return -EUCLEAN;
+
+	true_size = btrfs_stack_verity_descriptor_size(&item);
+	if (true_size > INT_MAX)
+		return -EUCLEAN;
+
+	if (buf_size == 0)
+		return true_size;
+	if (buf_size < true_size)
+		return -ERANGE;
+
+	ret = read_key_bytes(BTRFS_I(inode), BTRFS_VERITY_DESC_ITEM_KEY, 1,
+			     buf, buf_size, NULL);
+	if (ret < 0)
+		return ret;
+	if (ret != true_size)
+		return -EIO;
+
+	return true_size;
+}
+
+/*
+ * fsverity op that reads and caches a merkle tree page.
+ *
+ * @inode:         inode to read a merkle tree page for
+ * @index:         page index relative to the start of the merkle tree
+ * @num_ra_pages:  number of pages to readahead. Optional, we ignore it
+ *
+ * The Merkle tree is stored in the filesystem btree, but its pages are cached
+ * with a logical position past EOF in the inode's mapping.
+ *
+ * Returns the page we read, or an ERR_PTR on error.
+ */
+static struct page *btrfs_read_merkle_tree_page(struct inode *inode,
+						pgoff_t index,
+						unsigned long num_ra_pages)
+{
+	struct page *page;
+	u64 off = (u64)index << PAGE_SHIFT;
+	loff_t merkle_pos = merkle_file_pos(inode);
+	int ret;
+
+	if (merkle_pos < 0)
+		return ERR_PTR(merkle_pos);
+	if (merkle_pos > inode->i_sb->s_maxbytes - off - PAGE_SIZE)
+		return ERR_PTR(-EFBIG);
+	index += merkle_pos >> PAGE_SHIFT;
+again:
+	page = find_get_page_flags(inode->i_mapping, index, FGP_ACCESSED);
+	if (page) {
+		if (PageUptodate(page))
+			return page;
+
+		lock_page(page);
+		/*
+		 * We only insert uptodate pages, so !Uptodate has to be
+		 * an error
+		 */
+		if (!PageUptodate(page)) {
+			unlock_page(page);
+			put_page(page);
+			return ERR_PTR(-EIO);
+		}
+		unlock_page(page);
+		return page;
+	}
+
+	page = __page_cache_alloc(mapping_gfp_constraint(inode->i_mapping, ~__GFP_FS));
+	if (!page)
+		return ERR_PTR(-ENOMEM);
+
+	/*
+	 * Merkle item keys are indexed from byte 0 in the merkle tree.
+	 * They have the form:
+	 *
+	 * [ inode objectid, BTRFS_MERKLE_ITEM_KEY, offset in bytes ]
+	 */
+	ret = read_key_bytes(BTRFS_I(inode), BTRFS_VERITY_MERKLE_ITEM_KEY, off,
+			     page_address(page), PAGE_SIZE, page);
+	if (ret < 0) {
+		put_page(page);
+		return ERR_PTR(ret);
+	}
+	if (ret < PAGE_SIZE)
+		memzero_page(page, ret, PAGE_SIZE - ret);
+
+	SetPageUptodate(page);
+	ret = add_to_page_cache_lru(page, inode->i_mapping, index, GFP_NOFS);
+
+	if (!ret) {
+		/* Inserted and ready for fsverity */
+		unlock_page(page);
+	} else {
+		put_page(page);
+		/* Did someone race us into inserting this page? */
+		if (ret == -EEXIST)
+			goto again;
+		page = ERR_PTR(ret);
+	}
+	return page;
+}
+
+/*
+ * fsverity op that writes a Merkle tree block into the btree.
+ *
+ * @inode:          inode to write a Merkle tree block for
+ * @buf:            Merkle tree data block to write
+ * @index:          index of the block in the Merkle tree
+ * @log_blocksize:  log base 2 of the Merkle tree block size
+ *
+ * Note that the block size could be different from the page size, so it is not
+ * safe to assume that index is a page index.
+ *
+ * Returns 0 on success or negative error code on failure
+ */
+static int btrfs_write_merkle_tree_block(struct inode *inode, const void *buf,
+					u64 index, int log_blocksize)
+{
+	u64 off = index << log_blocksize;
+	u64 len = 1ULL << log_blocksize;
+	loff_t merkle_pos = merkle_file_pos(inode);
+
+	if (merkle_pos < 0)
+		return merkle_pos;
+	if (merkle_pos > inode->i_sb->s_maxbytes - off - len)
+		return -EFBIG;
+
+	return write_key_bytes(BTRFS_I(inode), BTRFS_VERITY_MERKLE_ITEM_KEY,
+			       off, buf, len);
+}
+
+const struct fsverity_operations btrfs_verityops = {
+	.begin_enable_verity     = btrfs_begin_enable_verity,
+	.end_enable_verity       = btrfs_end_enable_verity,
+	.get_verity_descriptor   = btrfs_get_verity_descriptor,
+	.read_merkle_tree_page   = btrfs_read_merkle_tree_page,
+	.write_merkle_tree_block = btrfs_write_merkle_tree_block,
+};
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 70f94b75f25a..ec3a874165de 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -38,7 +38,7 @@ const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
 		.sub_stripes	= 2,
 		.dev_stripes	= 1,
 		.devs_max	= 0,	/* 0 == as many as possible */
-		.devs_min	= 4,
+		.devs_min	= 2,
 		.tolerated_failures = 1,
 		.devs_increment	= 2,
 		.ncopies	= 2,
@@ -103,7 +103,7 @@ const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
 		.sub_stripes	= 1,
 		.dev_stripes	= 1,
 		.devs_max	= 0,
-		.devs_min	= 2,
+		.devs_min	= 1,
 		.tolerated_failures = 0,
 		.devs_increment	= 1,
 		.ncopies	= 1,
@@ -153,6 +153,32 @@ const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
 	},
 };
 
+/*
+ * Convert block group flags (BTRFS_BLOCK_GROUP_*) to btrfs_raid_types, which
+ * can be used as index to access btrfs_raid_array[].
+ */
+enum btrfs_raid_types __attribute_const__ btrfs_bg_flags_to_raid_index(u64 flags)
+{
+	if (flags & BTRFS_BLOCK_GROUP_RAID10)
+		return BTRFS_RAID_RAID10;
+	else if (flags & BTRFS_BLOCK_GROUP_RAID1)
+		return BTRFS_RAID_RAID1;
+	else if (flags & BTRFS_BLOCK_GROUP_RAID1C3)
+		return BTRFS_RAID_RAID1C3;
+	else if (flags & BTRFS_BLOCK_GROUP_RAID1C4)
+		return BTRFS_RAID_RAID1C4;
+	else if (flags & BTRFS_BLOCK_GROUP_DUP)
+		return BTRFS_RAID_DUP;
+	else if (flags & BTRFS_BLOCK_GROUP_RAID0)
+		return BTRFS_RAID_RAID0;
+	else if (flags & BTRFS_BLOCK_GROUP_RAID5)
+		return BTRFS_RAID_RAID5;
+	else if (flags & BTRFS_BLOCK_GROUP_RAID6)
+		return BTRFS_RAID_RAID6;
+
+	return BTRFS_RAID_SINGLE; /* BTRFS_BLOCK_GROUP_SINGLE */
+}
+
 const char *btrfs_bg_type_to_raid_name(u64 flags)
 {
 	const int index = btrfs_bg_flags_to_raid_index(flags);
@@ -404,44 +430,6 @@ void __exit btrfs_cleanup_fs_uuids(void)
 	}
 }
 
-/*
- * Returns a pointer to a new btrfs_device on success; ERR_PTR() on error.
- * Returned struct is not linked onto any lists and must be destroyed using
- * btrfs_free_device.
- */
-static struct btrfs_device *__alloc_device(struct btrfs_fs_info *fs_info)
-{
-	struct btrfs_device *dev;
-
-	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
-	if (!dev)
-		return ERR_PTR(-ENOMEM);
-
-	/*
-	 * Preallocate a bio that's always going to be used for flushing device
-	 * barriers and matches the device lifespan
-	 */
-	dev->flush_bio = bio_kmalloc(GFP_KERNEL, 0);
-	if (!dev->flush_bio) {
-		kfree(dev);
-		return ERR_PTR(-ENOMEM);
-	}
-
-	INIT_LIST_HEAD(&dev->dev_list);
-	INIT_LIST_HEAD(&dev->dev_alloc_list);
-	INIT_LIST_HEAD(&dev->post_commit_list);
-
-	atomic_set(&dev->reada_in_flight, 0);
-	atomic_set(&dev->dev_stats_ccnt, 0);
-	btrfs_device_data_ordered_init(dev);
-	INIT_RADIX_TREE(&dev->reada_zones, GFP_NOFS & ~__GFP_DIRECT_RECLAIM);
-	INIT_RADIX_TREE(&dev->reada_extents, GFP_NOFS & ~__GFP_DIRECT_RECLAIM);
-	extent_io_tree_init(fs_info, &dev->alloc_state,
-			    IO_TREE_DEVICE_ALLOC_STATE, NULL);
-
-	return dev;
-}
-
 static noinline struct btrfs_fs_devices *find_fsid(
 		const u8 *fsid, const u8 *metadata_fsid)
 {
@@ -1130,6 +1118,9 @@ static void btrfs_close_one_device(struct btrfs_device *device)
 		fs_devices->rw_devices--;
 	}
 
+	if (device->devid == BTRFS_DEV_REPLACE_DEVID)
+		clear_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state);
+
 	if (test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state))
 		fs_devices->missing_devices--;
 
@@ -1228,7 +1219,7 @@ static int open_fs_devices(struct btrfs_fs_devices *fs_devices,
 static int devid_cmp(void *priv, const struct list_head *a,
 		     const struct list_head *b)
 {
-	struct btrfs_device *dev1, *dev2;
+	const struct btrfs_device *dev1, *dev2;
 
 	dev1 = list_entry(a, struct btrfs_device, dev_list);
 	dev2 = list_entry(b, struct btrfs_device, dev_list);
@@ -1598,14 +1589,9 @@ again:
 	key.offset = search_start;
 	key.type = BTRFS_DEV_EXTENT_KEY;
 
-	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+	ret = btrfs_search_backwards(root, &key, path);
 	if (ret < 0)
 		goto out;
-	if (ret > 0) {
-		ret = btrfs_previous_item(root, path, key.objectid, key.type);
-		if (ret < 0)
-			goto out;
-	}
 
 	while (1) {
 		l = path->nodes[0];
@@ -1759,48 +1745,6 @@ out:
 	return ret;
 }
 
-static int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
-				  struct btrfs_device *device,
-				  u64 chunk_offset, u64 start, u64 num_bytes)
-{
-	int ret;
-	struct btrfs_path *path;
-	struct btrfs_fs_info *fs_info = device->fs_info;
-	struct btrfs_root *root = fs_info->dev_root;
-	struct btrfs_dev_extent *extent;
-	struct extent_buffer *leaf;
-	struct btrfs_key key;
-
-	WARN_ON(!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state));
-	WARN_ON(test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state));
-	path = btrfs_alloc_path();
-	if (!path)
-		return -ENOMEM;
-
-	key.objectid = device->devid;
-	key.offset = start;
-	key.type = BTRFS_DEV_EXTENT_KEY;
-	ret = btrfs_insert_empty_item(trans, root, path, &key,
-				      sizeof(*extent));
-	if (ret)
-		goto out;
-
-	leaf = path->nodes[0];
-	extent = btrfs_item_ptr(leaf, path->slots[0],
-				struct btrfs_dev_extent);
-	btrfs_set_dev_extent_chunk_tree(leaf, extent,
-					BTRFS_CHUNK_TREE_OBJECTID);
-	btrfs_set_dev_extent_chunk_objectid(leaf, extent,
-					    BTRFS_FIRST_CHUNK_TREE_OBJECTID);
-	btrfs_set_dev_extent_chunk_offset(leaf, extent, chunk_offset);
-
-	btrfs_set_dev_extent_length(leaf, extent, num_bytes);
-	btrfs_mark_buffer_dirty(leaf);
-out:
-	btrfs_free_path(path);
-	return ret;
-}
-
 static u64 find_next_chunk(struct btrfs_fs_info *fs_info)
 {
 	struct extent_map_tree *em_tree;
@@ -2003,12 +1947,8 @@ static int btrfs_check_raid_min_devices(struct btrfs_fs_info *fs_info,
 		if (!(all_avail & btrfs_raid_array[i].bg_flag))
 			continue;
 
-		if (num_devices < btrfs_raid_array[i].devs_min) {
-			int ret = btrfs_raid_array[i].mindev_error;
-
-			if (ret)
-				return ret;
-		}
+		if (num_devices < btrfs_raid_array[i].devs_min)
+			return btrfs_raid_array[i].mindev_error;
 	}
 
 	return 0;
@@ -2137,7 +2077,7 @@ int btrfs_rm_device(struct btrfs_fs_info *fs_info, const char *device_path,
 
 	if (IS_ERR(device)) {
 		if (PTR_ERR(device) == -ENOENT &&
-		    strcmp(device_path, "missing") == 0)
+		    device_path && strcmp(device_path, "missing") == 0)
 			ret = BTRFS_ERROR_DEV_MISSING_NOT_FOUND;
 		else
 			ret = PTR_ERR(device);
@@ -3622,10 +3562,7 @@ static u64 calc_data_stripes(u64 type, int num_stripes)
 	const int ncopies = btrfs_raid_array[index].ncopies;
 	const int nparity = btrfs_raid_array[index].nparity;
 
-	if (nparity)
-		return num_stripes - nparity;
-	else
-		return num_stripes / ncopies;
+	return (num_stripes - nparity) / ncopies;
 }
 
 /* [pstart, pend) */
@@ -4025,6 +3962,13 @@ static inline int validate_convert_profile(struct btrfs_fs_info *fs_info,
 	if (!(bargs->flags & BTRFS_BALANCE_ARGS_CONVERT))
 		return true;
 
+	if (fs_info->sectorsize < PAGE_SIZE &&
+		bargs->target & BTRFS_BLOCK_GROUP_RAID56_MASK) {
+		btrfs_err(fs_info,
+		"RAID56 is not yet supported for sectorsize %u with page size %lu",
+			  fs_info->sectorsize, PAGE_SIZE);
+		return false;
+	}
 	/* Profile is valid and does not have bits outside of the allowed set */
 	if (alloc_profile_is_valid(bargs->target, 1) &&
 	    (bargs->target & ~allowed) == 0)
@@ -5464,56 +5408,6 @@ out:
 }
 
 /*
- * This function, btrfs_finish_chunk_alloc(), belongs to phase 2.
- *
- * See the comment at btrfs_chunk_alloc() for details about the chunk allocation
- * phases.
- */
-int btrfs_finish_chunk_alloc(struct btrfs_trans_handle *trans,
-			     u64 chunk_offset, u64 chunk_size)
-{
-	struct btrfs_fs_info *fs_info = trans->fs_info;
-	struct btrfs_device *device;
-	struct extent_map *em;
-	struct map_lookup *map;
-	u64 dev_offset;
-	u64 stripe_size;
-	int i;
-	int ret = 0;
-
-	em = btrfs_get_chunk_map(fs_info, chunk_offset, chunk_size);
-	if (IS_ERR(em))
-		return PTR_ERR(em);
-
-	map = em->map_lookup;
-	stripe_size = em->orig_block_len;
-
-	/*
-	 * Take the device list mutex to prevent races with the final phase of
-	 * a device replace operation that replaces the device object associated
-	 * with the map's stripes, because the device object's id can change
-	 * at any time during that final phase of the device replace operation
-	 * (dev-replace.c:btrfs_dev_replace_finishing()), so we could grab the
-	 * replaced device and then see it with an ID of BTRFS_DEV_REPLACE_DEVID,
-	 * resulting in persisting a device extent item with such ID.
-	 */
-	mutex_lock(&fs_info->fs_devices->device_list_mutex);
-	for (i = 0; i < map->num_stripes; i++) {
-		device = map->stripes[i].dev;
-		dev_offset = map->stripes[i].physical;
-
-		ret = btrfs_alloc_dev_extent(trans, device, chunk_offset,
-					     dev_offset, stripe_size);
-		if (ret)
-			break;
-	}
-	mutex_unlock(&fs_info->fs_devices->device_list_mutex);
-
-	free_extent_map(em);
-	return ret;
-}
-
-/*
  * This function, btrfs_chunk_alloc_add_chunk_item(), typically belongs to the
  * phase 1 of chunk allocation. It belongs to phase 2 only when allocating system
  * chunks.
@@ -6923,9 +6817,31 @@ struct btrfs_device *btrfs_alloc_device(struct btrfs_fs_info *fs_info,
 	if (WARN_ON(!devid && !fs_info))
 		return ERR_PTR(-EINVAL);
 
-	dev = __alloc_device(fs_info);
-	if (IS_ERR(dev))
-		return dev;
+	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+	if (!dev)
+		return ERR_PTR(-ENOMEM);
+
+	/*
+	 * Preallocate a bio that's always going to be used for flushing device
+	 * barriers and matches the device lifespan
+	 */
+	dev->flush_bio = bio_kmalloc(GFP_KERNEL, 0);
+	if (!dev->flush_bio) {
+		kfree(dev);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	INIT_LIST_HEAD(&dev->dev_list);
+	INIT_LIST_HEAD(&dev->dev_alloc_list);
+	INIT_LIST_HEAD(&dev->post_commit_list);
+
+	atomic_set(&dev->reada_in_flight, 0);
+	atomic_set(&dev->dev_stats_ccnt, 0);
+	btrfs_device_data_ordered_init(dev);
+	INIT_RADIX_TREE(&dev->reada_zones, GFP_NOFS & ~__GFP_DIRECT_RECLAIM);
+	INIT_RADIX_TREE(&dev->reada_extents, GFP_NOFS & ~__GFP_DIRECT_RECLAIM);
+	extent_io_tree_init(fs_info, &dev->alloc_state,
+			    IO_TREE_DEVICE_ALLOC_STATE, NULL);
 
 	if (devid)
 		tmp = *devid;
@@ -6961,15 +6877,7 @@ static void btrfs_report_missing_device(struct btrfs_fs_info *fs_info,
 
 static u64 calc_stripe_length(u64 type, u64 chunk_len, int num_stripes)
 {
-	int index = btrfs_bg_flags_to_raid_index(type);
-	int ncopies = btrfs_raid_array[index].ncopies;
-	const int nparity = btrfs_raid_array[index].nparity;
-	int data_stripes;
-
-	if (nparity)
-		data_stripes = num_stripes - nparity;
-	else
-		data_stripes = num_stripes / ncopies;
+	const int data_stripes = calc_data_stripes(type, num_stripes);
 
 	return div_u64(chunk_len, data_stripes);
 }
@@ -8144,7 +8052,7 @@ int btrfs_verify_dev_extents(struct btrfs_fs_info *fs_info)
 		goto out;
 
 	if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
-		ret = btrfs_next_item(root, path);
+		ret = btrfs_next_leaf(root, path);
 		if (ret < 0)
 			goto out;
 		/* No dev extents at all? Not good */
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 55a8ba244716..b082250b42e0 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -508,8 +508,6 @@ int btrfs_is_parity_mirror(struct btrfs_fs_info *fs_info,
 			   u64 logical, u64 len);
 unsigned long btrfs_full_stripe_len(struct btrfs_fs_info *fs_info,
 				    u64 logical);
-int btrfs_finish_chunk_alloc(struct btrfs_trans_handle *trans,
-			     u64 chunk_offset, u64 chunk_size);
 int btrfs_chunk_alloc_add_chunk_item(struct btrfs_trans_handle *trans,
 				     struct btrfs_block_group *bg);
 int btrfs_remove_chunk(struct btrfs_trans_handle *trans, u64 chunk_offset);
@@ -568,32 +566,6 @@ static inline void btrfs_dev_stat_set(struct btrfs_device *dev,
 	atomic_inc(&dev->dev_stats_ccnt);
 }
 
-/*
- * Convert block group flags (BTRFS_BLOCK_GROUP_*) to btrfs_raid_types, which
- * can be used as index to access btrfs_raid_array[].
- */
-static inline enum btrfs_raid_types btrfs_bg_flags_to_raid_index(u64 flags)
-{
-	if (flags & BTRFS_BLOCK_GROUP_RAID10)
-		return BTRFS_RAID_RAID10;
-	else if (flags & BTRFS_BLOCK_GROUP_RAID1)
-		return BTRFS_RAID_RAID1;
-	else if (flags & BTRFS_BLOCK_GROUP_RAID1C3)
-		return BTRFS_RAID_RAID1C3;
-	else if (flags & BTRFS_BLOCK_GROUP_RAID1C4)
-		return BTRFS_RAID_RAID1C4;
-	else if (flags & BTRFS_BLOCK_GROUP_DUP)
-		return BTRFS_RAID_DUP;
-	else if (flags & BTRFS_BLOCK_GROUP_RAID0)
-		return BTRFS_RAID_RAID0;
-	else if (flags & BTRFS_BLOCK_GROUP_RAID5)
-		return BTRFS_RAID_RAID5;
-	else if (flags & BTRFS_BLOCK_GROUP_RAID6)
-		return BTRFS_RAID_RAID6;
-
-	return BTRFS_RAID_SINGLE; /* BTRFS_BLOCK_GROUP_SINGLE */
-}
-
 void btrfs_commit_device_sizes(struct btrfs_transaction *trans);
 
 struct list_head * __attribute_const__ btrfs_get_fs_uuids(void);
@@ -603,6 +575,7 @@ void btrfs_scratch_superblocks(struct btrfs_fs_info *fs_info,
 			       struct block_device *bdev,
 			       const char *device_path);
 
+enum btrfs_raid_types __attribute_const__ btrfs_bg_flags_to_raid_index(u64 flags);
 int btrfs_bg_type_to_factor(u64 flags);
 const char *btrfs_bg_type_to_raid_name(u64 flags);
 int btrfs_verify_dev_extents(struct btrfs_fs_info *fs_info);
diff --git a/fs/btrfs/zlib.c b/fs/btrfs/zlib.c
index c3fa7d3fa770..8afa90074891 100644
--- a/fs/btrfs/zlib.c
+++ b/fs/btrfs/zlib.c
@@ -121,12 +121,12 @@ int zlib_compress_pages(struct list_head *ws, struct address_space *mapping,
 	workspace->strm.total_in = 0;
 	workspace->strm.total_out = 0;
 
-	out_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
+	out_page = alloc_page(GFP_NOFS);
 	if (out_page == NULL) {
 		ret = -ENOMEM;
 		goto out;
 	}
-	cpage_out = kmap(out_page);
+	cpage_out = page_address(out_page);
 	pages[0] = out_page;
 	nr_pages = 1;
 
@@ -148,26 +148,22 @@ int zlib_compress_pages(struct list_head *ws, struct address_space *mapping,
 				int i;
 
 				for (i = 0; i < in_buf_pages; i++) {
-					if (in_page) {
-						kunmap(in_page);
+					if (in_page)
 						put_page(in_page);
-					}
 					in_page = find_get_page(mapping,
 								start >> PAGE_SHIFT);
-					data_in = kmap(in_page);
+					data_in = page_address(in_page);
 					memcpy(workspace->buf + i * PAGE_SIZE,
 					       data_in, PAGE_SIZE);
 					start += PAGE_SIZE;
 				}
 				workspace->strm.next_in = workspace->buf;
 			} else {
-				if (in_page) {
-					kunmap(in_page);
+				if (in_page)
 					put_page(in_page);
-				}
 				in_page = find_get_page(mapping,
 							start >> PAGE_SHIFT);
-				data_in = kmap(in_page);
+				data_in = page_address(in_page);
 				start += PAGE_SIZE;
 				workspace->strm.next_in = data_in;
 			}
@@ -196,18 +192,17 @@ int zlib_compress_pages(struct list_head *ws, struct address_space *mapping,
 		 * the stream end if required
 		 */
 		if (workspace->strm.avail_out == 0) {
-			kunmap(out_page);
 			if (nr_pages == nr_dest_pages) {
 				out_page = NULL;
 				ret = -E2BIG;
 				goto out;
 			}
-			out_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
+			out_page = alloc_page(GFP_NOFS);
 			if (out_page == NULL) {
 				ret = -ENOMEM;
 				goto out;
 			}
-			cpage_out = kmap(out_page);
+			cpage_out = page_address(out_page);
 			pages[nr_pages] = out_page;
 			nr_pages++;
 			workspace->strm.avail_out = PAGE_SIZE;
@@ -234,18 +229,17 @@ int zlib_compress_pages(struct list_head *ws, struct address_space *mapping,
 			goto out;
 		} else if (workspace->strm.avail_out == 0) {
 			/* get another page for the stream end */
-			kunmap(out_page);
 			if (nr_pages == nr_dest_pages) {
 				out_page = NULL;
 				ret = -E2BIG;
 				goto out;
 			}
-			out_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
+			out_page = alloc_page(GFP_NOFS);
 			if (out_page == NULL) {
 				ret = -ENOMEM;
 				goto out;
 			}
-			cpage_out = kmap(out_page);
+			cpage_out = page_address(out_page);
 			pages[nr_pages] = out_page;
 			nr_pages++;
 			workspace->strm.avail_out = PAGE_SIZE;
@@ -264,13 +258,8 @@ int zlib_compress_pages(struct list_head *ws, struct address_space *mapping,
 	*total_in = workspace->strm.total_in;
 out:
 	*out_pages = nr_pages;
-	if (out_page)
-		kunmap(out_page);
-
-	if (in_page) {
-		kunmap(in_page);
+	if (in_page)
 		put_page(in_page);
-	}
 	return ret;
 }
 
@@ -286,10 +275,8 @@ int zlib_decompress_bio(struct list_head *ws, struct compressed_bio *cb)
 	unsigned long total_pages_in = DIV_ROUND_UP(srclen, PAGE_SIZE);
 	unsigned long buf_start;
 	struct page **pages_in = cb->compressed_pages;
-	u64 disk_start = cb->start;
-	struct bio *orig_bio = cb->orig_bio;
 
-	data_in = kmap(pages_in[page_in_index]);
+	data_in = page_address(pages_in[page_in_index]);
 	workspace->strm.next_in = data_in;
 	workspace->strm.avail_in = min_t(size_t, srclen, PAGE_SIZE);
 	workspace->strm.total_in = 0;
@@ -311,7 +298,6 @@ int zlib_decompress_bio(struct list_head *ws, struct compressed_bio *cb)
 
 	if (Z_OK != zlib_inflateInit2(&workspace->strm, wbits)) {
 		pr_warn("BTRFS: inflateInit failed\n");
-		kunmap(pages_in[page_in_index]);
 		return -EIO;
 	}
 	while (workspace->strm.total_in < srclen) {
@@ -326,9 +312,8 @@ int zlib_decompress_bio(struct list_head *ws, struct compressed_bio *cb)
 		if (buf_start == total_out)
 			break;
 
-		ret2 = btrfs_decompress_buf2page(workspace->buf, buf_start,
-						 total_out, disk_start,
-						 orig_bio);
+		ret2 = btrfs_decompress_buf2page(workspace->buf,
+				total_out - buf_start, cb, buf_start);
 		if (ret2 == 0) {
 			ret = 0;
 			goto done;
@@ -339,17 +324,16 @@ int zlib_decompress_bio(struct list_head *ws, struct compressed_bio *cb)
 
 		if (workspace->strm.avail_in == 0) {
 			unsigned long tmp;
-			kunmap(pages_in[page_in_index]);
+
 			page_in_index++;
 			if (page_in_index >= total_pages_in) {
 				data_in = NULL;
 				break;
 			}
-			data_in = kmap(pages_in[page_in_index]);
+			data_in = page_address(pages_in[page_in_index]);
 			workspace->strm.next_in = data_in;
 			tmp = srclen - workspace->strm.total_in;
-			workspace->strm.avail_in = min(tmp,
-							   PAGE_SIZE);
+			workspace->strm.avail_in = min(tmp, PAGE_SIZE);
 		}
 	}
 	if (ret != Z_STREAM_END)
@@ -358,10 +342,8 @@ int zlib_decompress_bio(struct list_head *ws, struct compressed_bio *cb)
 		ret = 0;
 done:
 	zlib_inflateEnd(&workspace->strm);
-	if (data_in)
-		kunmap(pages_in[page_in_index]);
 	if (!ret)
-		zero_fill_bio(orig_bio);
+		zero_fill_bio(cb->orig_bio);
 	return ret;
 }
 
diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
index 907c2cc45c9c..47af1ab3bf12 100644
--- a/fs/btrfs/zoned.c
+++ b/fs/btrfs/zoned.c
@@ -245,7 +245,7 @@ static int calculate_emulated_zone_size(struct btrfs_fs_info *fs_info)
 		goto out;
 
 	if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
-		ret = btrfs_next_item(root, path);
+		ret = btrfs_next_leaf(root, path);
 		if (ret < 0)
 			goto out;
 		/* No dev extents at all? Not good */
@@ -296,7 +296,6 @@ int btrfs_get_dev_zone_info(struct btrfs_device *device)
 	struct btrfs_fs_info *fs_info = device->fs_info;
 	struct btrfs_zoned_device_info *zone_info = NULL;
 	struct block_device *bdev = device->bdev;
-	struct request_queue *queue = bdev_get_queue(bdev);
 	sector_t nr_sectors;
 	sector_t sector = 0;
 	struct blk_zone *zones = NULL;
@@ -348,19 +347,10 @@ int btrfs_get_dev_zone_info(struct btrfs_device *device)
 
 	nr_sectors = bdev_nr_sectors(bdev);
 	zone_info->zone_size_shift = ilog2(zone_info->zone_size);
-	zone_info->max_zone_append_size =
-		(u64)queue_max_zone_append_sectors(queue) << SECTOR_SHIFT;
 	zone_info->nr_zones = nr_sectors >> ilog2(zone_sectors);
 	if (!IS_ALIGNED(nr_sectors, zone_sectors))
 		zone_info->nr_zones++;
 
-	if (bdev_is_zoned(bdev) && zone_info->max_zone_append_size == 0) {
-		btrfs_err(fs_info, "zoned: device %pg does not support zone append",
-			  bdev);
-		ret = -EINVAL;
-		goto out;
-	}
-
 	zone_info->seq_zones = bitmap_zalloc(zone_info->nr_zones, GFP_KERNEL);
 	if (!zone_info->seq_zones) {
 		ret = -ENOMEM;
@@ -529,7 +519,6 @@ int btrfs_check_zoned_mode(struct btrfs_fs_info *fs_info)
 	u64 zoned_devices = 0;
 	u64 nr_devices = 0;
 	u64 zone_size = 0;
-	u64 max_zone_append_size = 0;
 	const bool incompat_zoned = btrfs_fs_incompat(fs_info, ZONED);
 	int ret = 0;
 
@@ -565,11 +554,6 @@ int btrfs_check_zoned_mode(struct btrfs_fs_info *fs_info)
 				ret = -EINVAL;
 				goto out;
 			}
-			if (!max_zone_append_size ||
-			    (zone_info->max_zone_append_size &&
-			     zone_info->max_zone_append_size < max_zone_append_size))
-				max_zone_append_size =
-					zone_info->max_zone_append_size;
 		}
 		nr_devices++;
 	}
@@ -619,7 +603,6 @@ int btrfs_check_zoned_mode(struct btrfs_fs_info *fs_info)
 	}
 
 	fs_info->zone_size = zone_size;
-	fs_info->max_zone_append_size = max_zone_append_size;
 	fs_info->fs_devices->chunk_alloc_policy = BTRFS_CHUNK_ALLOC_ZONED;
 
 	/*
@@ -1318,9 +1301,6 @@ bool btrfs_use_zone_append(struct btrfs_inode *inode, u64 start)
 	if (!btrfs_is_zoned(fs_info))
 		return false;
 
-	if (!fs_info->max_zone_append_size)
-		return false;
-
 	if (!is_data_inode(&inode->vfs_inode))
 		return false;
 
diff --git a/fs/btrfs/zoned.h b/fs/btrfs/zoned.h
index b0ae2608cb6b..4b299705bb12 100644
--- a/fs/btrfs/zoned.h
+++ b/fs/btrfs/zoned.h
@@ -22,7 +22,6 @@ struct btrfs_zoned_device_info {
 	 */
 	u64 zone_size;
 	u8  zone_size_shift;
-	u64 max_zone_append_size;
 	u32 nr_zones;
 	unsigned long *seq_zones;
 	unsigned long *empty_zones;
diff --git a/fs/btrfs/zstd.c b/fs/btrfs/zstd.c
index 3e26b466476a..56dce9f00988 100644
--- a/fs/btrfs/zstd.c
+++ b/fs/btrfs/zstd.c
@@ -399,19 +399,19 @@ int zstd_compress_pages(struct list_head *ws, struct address_space *mapping,
 
 	/* map in the first page of input data */
 	in_page = find_get_page(mapping, start >> PAGE_SHIFT);
-	workspace->in_buf.src = kmap(in_page);
+	workspace->in_buf.src = page_address(in_page);
 	workspace->in_buf.pos = 0;
 	workspace->in_buf.size = min_t(size_t, len, PAGE_SIZE);
 
 
 	/* Allocate and map in the output buffer */
-	out_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
+	out_page = alloc_page(GFP_NOFS);
 	if (out_page == NULL) {
 		ret = -ENOMEM;
 		goto out;
 	}
 	pages[nr_pages++] = out_page;
-	workspace->out_buf.dst = kmap(out_page);
+	workspace->out_buf.dst = page_address(out_page);
 	workspace->out_buf.pos = 0;
 	workspace->out_buf.size = min_t(size_t, max_out, PAGE_SIZE);
 
@@ -446,19 +446,18 @@ int zstd_compress_pages(struct list_head *ws, struct address_space *mapping,
 		if (workspace->out_buf.pos == workspace->out_buf.size) {
 			tot_out += PAGE_SIZE;
 			max_out -= PAGE_SIZE;
-			kunmap(out_page);
 			if (nr_pages == nr_dest_pages) {
 				out_page = NULL;
 				ret = -E2BIG;
 				goto out;
 			}
-			out_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
+			out_page = alloc_page(GFP_NOFS);
 			if (out_page == NULL) {
 				ret = -ENOMEM;
 				goto out;
 			}
 			pages[nr_pages++] = out_page;
-			workspace->out_buf.dst = kmap(out_page);
+			workspace->out_buf.dst = page_address(out_page);
 			workspace->out_buf.pos = 0;
 			workspace->out_buf.size = min_t(size_t, max_out,
 							PAGE_SIZE);
@@ -473,13 +472,12 @@ int zstd_compress_pages(struct list_head *ws, struct address_space *mapping,
 		/* Check if we need more input */
 		if (workspace->in_buf.pos == workspace->in_buf.size) {
 			tot_in += PAGE_SIZE;
-			kunmap(in_page);
 			put_page(in_page);
 
 			start += PAGE_SIZE;
 			len -= PAGE_SIZE;
 			in_page = find_get_page(mapping, start >> PAGE_SHIFT);
-			workspace->in_buf.src = kmap(in_page);
+			workspace->in_buf.src = page_address(in_page);
 			workspace->in_buf.pos = 0;
 			workspace->in_buf.size = min_t(size_t, len, PAGE_SIZE);
 		}
@@ -506,19 +504,18 @@ int zstd_compress_pages(struct list_head *ws, struct address_space *mapping,
 
 		tot_out += PAGE_SIZE;
 		max_out -= PAGE_SIZE;
-		kunmap(out_page);
 		if (nr_pages == nr_dest_pages) {
 			out_page = NULL;
 			ret = -E2BIG;
 			goto out;
 		}
-		out_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
+		out_page = alloc_page(GFP_NOFS);
 		if (out_page == NULL) {
 			ret = -ENOMEM;
 			goto out;
 		}
 		pages[nr_pages++] = out_page;
-		workspace->out_buf.dst = kmap(out_page);
+		workspace->out_buf.dst = page_address(out_page);
 		workspace->out_buf.pos = 0;
 		workspace->out_buf.size = min_t(size_t, max_out, PAGE_SIZE);
 	}
@@ -534,12 +531,8 @@ int zstd_compress_pages(struct list_head *ws, struct address_space *mapping,
 out:
 	*out_pages = nr_pages;
 	/* Cleanup */
-	if (in_page) {
-		kunmap(in_page);
+	if (in_page)
 		put_page(in_page);
-	}
-	if (out_page)
-		kunmap(out_page);
 	return ret;
 }
 
@@ -547,8 +540,6 @@ int zstd_decompress_bio(struct list_head *ws, struct compressed_bio *cb)
 {
 	struct workspace *workspace = list_entry(ws, struct workspace, list);
 	struct page **pages_in = cb->compressed_pages;
-	u64 disk_start = cb->start;
-	struct bio *orig_bio = cb->orig_bio;
 	size_t srclen = cb->compressed_len;
 	ZSTD_DStream *stream;
 	int ret = 0;
@@ -565,7 +556,7 @@ int zstd_decompress_bio(struct list_head *ws, struct compressed_bio *cb)
 		goto done;
 	}
 
-	workspace->in_buf.src = kmap(pages_in[page_in_index]);
+	workspace->in_buf.src = page_address(pages_in[page_in_index]);
 	workspace->in_buf.pos = 0;
 	workspace->in_buf.size = min_t(size_t, srclen, PAGE_SIZE);
 
@@ -589,7 +580,7 @@ int zstd_decompress_bio(struct list_head *ws, struct compressed_bio *cb)
 		workspace->out_buf.pos = 0;
 
 		ret = btrfs_decompress_buf2page(workspace->out_buf.dst,
-				buf_start, total_out, disk_start, orig_bio);
+				total_out - buf_start, cb, buf_start);
 		if (ret == 0)
 			break;
 
@@ -601,23 +592,21 @@ int zstd_decompress_bio(struct list_head *ws, struct compressed_bio *cb)
 			break;
 
 		if (workspace->in_buf.pos == workspace->in_buf.size) {
-			kunmap(pages_in[page_in_index++]);
+			page_in_index++;
 			if (page_in_index >= total_pages_in) {
 				workspace->in_buf.src = NULL;
 				ret = -EIO;
 				goto done;
 			}
 			srclen -= PAGE_SIZE;
-			workspace->in_buf.src = kmap(pages_in[page_in_index]);
+			workspace->in_buf.src = page_address(pages_in[page_in_index]);
 			workspace->in_buf.pos = 0;
 			workspace->in_buf.size = min_t(size_t, srclen, PAGE_SIZE);
 		}
 	}
 	ret = 0;
-	zero_fill_bio(orig_bio);
+	zero_fill_bio(cb->orig_bio);
 done:
-	if (workspace->in_buf.src)
-		kunmap(pages_in[page_in_index]);
 	return ret;
 }
 
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 4c3370548982..eb57dade6076 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -2730,23 +2730,6 @@ int write_inode_now(struct inode *inode, int sync)
 EXPORT_SYMBOL(write_inode_now);
 
 /**
- * sync_inode - write an inode and its pages to disk.
- * @inode: the inode to sync
- * @wbc: controls the writeback mode
- *
- * sync_inode() will write an inode and its pages to disk.  It will also
- * correctly update the inode on its superblock's dirty inode lists and will
- * update inode->i_state.
- *
- * The caller must have a ref on the inode.
- */
-int sync_inode(struct inode *inode, struct writeback_control *wbc)
-{
-	return writeback_single_inode(inode, wbc);
-}
-EXPORT_SYMBOL(sync_inode);
-
-/**
  * sync_inode_metadata - write an inode to disk
  * @inode: the inode to sync
  * @wait: wait for I/O to complete.
@@ -2762,6 +2745,6 @@ int sync_inode_metadata(struct inode *inode, int wait)
 		.nr_to_write = 0, /* metadata-only */
 	};
 
-	return sync_inode(inode, &wbc);
+	return writeback_single_inode(inode, &wbc);
 }
 EXPORT_SYMBOL(sync_inode_metadata);
diff --git a/fs/namei.c b/fs/namei.c
index 32351c045bae..d049d3972695 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2598,8 +2598,9 @@ int vfs_path_lookup(struct dentry *dentry, struct vfsmount *mnt,
 }
 EXPORT_SYMBOL(vfs_path_lookup);
 
-static int lookup_one_len_common(const char *name, struct dentry *base,
-				 int len, struct qstr *this)
+static int lookup_one_common(struct user_namespace *mnt_userns,
+			     const char *name, struct dentry *base, int len,
+			     struct qstr *this)
 {
 	this->name = name;
 	this->len = len;
@@ -2627,7 +2628,7 @@ static int lookup_one_len_common(const char *name, struct dentry *base,
 			return err;
 	}
 
-	return inode_permission(&init_user_ns, base->d_inode, MAY_EXEC);
+	return inode_permission(mnt_userns, base->d_inode, MAY_EXEC);
 }
 
 /**
@@ -2651,7 +2652,7 @@ struct dentry *try_lookup_one_len(const char *name, struct dentry *base, int len
 
 	WARN_ON_ONCE(!inode_is_locked(base->d_inode));
 
-	err = lookup_one_len_common(name, base, len, &this);
+	err = lookup_one_common(&init_user_ns, name, base, len, &this);
 	if (err)
 		return ERR_PTR(err);
 
@@ -2678,7 +2679,7 @@ struct dentry *lookup_one_len(const char *name, struct dentry *base, int len)
 
 	WARN_ON_ONCE(!inode_is_locked(base->d_inode));
 
-	err = lookup_one_len_common(name, base, len, &this);
+	err = lookup_one_common(&init_user_ns, name, base, len, &this);
 	if (err)
 		return ERR_PTR(err);
 
@@ -2688,6 +2689,36 @@ struct dentry *lookup_one_len(const char *name, struct dentry *base, int len)
 EXPORT_SYMBOL(lookup_one_len);
 
 /**
+ * lookup_one - filesystem helper to lookup single pathname component
+ * @mnt_userns:	user namespace of the mount the lookup is performed from
+ * @name:	pathname component to lookup
+ * @base:	base directory to lookup from
+ * @len:	maximum length @len should be interpreted to
+ *
+ * Note that this routine is purely a helper for filesystem usage and should
+ * not be called by generic code.
+ *
+ * The caller must hold base->i_mutex.
+ */
+struct dentry *lookup_one(struct user_namespace *mnt_userns, const char *name,
+			  struct dentry *base, int len)
+{
+	struct dentry *dentry;
+	struct qstr this;
+	int err;
+
+	WARN_ON_ONCE(!inode_is_locked(base->d_inode));
+
+	err = lookup_one_common(mnt_userns, name, base, len, &this);
+	if (err)
+		return ERR_PTR(err);
+
+	dentry = lookup_dcache(&this, base, 0);
+	return dentry ? dentry : __lookup_slow(&this, base, 0);
+}
+EXPORT_SYMBOL(lookup_one);
+
+/**
  * lookup_one_len_unlocked - filesystem helper to lookup single pathname component
  * @name:	pathname component to lookup
  * @base:	base directory to lookup from
@@ -2706,7 +2737,7 @@ struct dentry *lookup_one_len_unlocked(const char *name,
 	int err;
 	struct dentry *ret;
 
-	err = lookup_one_len_common(name, base, len, &this);
+	err = lookup_one_common(&init_user_ns, name, base, len, &this);
 	if (err)
 		return ERR_PTR(err);
 
diff --git a/include/linux/bio.h b/include/linux/bio.h
index 3d67d0fbc868..00952e92eae1 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -374,7 +374,7 @@ static inline void bip_set_seed(struct bio_integrity_payload *bip,
 
 #endif /* CONFIG_BLK_DEV_INTEGRITY */
 
-extern void bio_trim(struct bio *bio, int offset, int size);
+void bio_trim(struct bio *bio, sector_t offset, sector_t size);
 extern struct bio *bio_split(struct bio *bio, int sectors,
 			     gfp_t gfp, struct bio_set *bs);
 
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index 9e392daa1d7f..be622b5a21ed 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -277,6 +277,7 @@ struct bio {
 };
 
 #define BIO_RESET_BYTES		offsetof(struct bio, bi_max_vecs)
+#define BIO_MAX_SECTORS		(UINT_MAX >> SECTOR_SHIFT)
 
 /*
  * bio flags
diff --git a/include/linux/fs.h b/include/linux/fs.h
index c58c2611a195..2c2bcfb12fef 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2500,7 +2500,6 @@ static inline void file_accessed(struct file *file)
 
 extern int file_modified(struct file *file);
 
-int sync_inode(struct inode *inode, struct writeback_control *wbc);
 int sync_inode_metadata(struct inode *inode, int wait);
 
 struct file_system_type {
@@ -2852,6 +2851,8 @@ extern int filemap_fdatawrite_range(struct address_space *mapping,
 				loff_t start, loff_t end);
 extern int filemap_check_errors(struct address_space *mapping);
 extern void __filemap_set_wb_err(struct address_space *mapping, int err);
+int filemap_fdatawrite_wbc(struct address_space *mapping,
+			   struct writeback_control *wbc);
 
 static inline int filemap_write_and_wait(struct address_space *mapping)
 {
diff --git a/include/linux/namei.h b/include/linux/namei.h
index be9a2b349ca7..e89329bb3134 100644
--- a/include/linux/namei.h
+++ b/include/linux/namei.h
@@ -68,6 +68,7 @@ extern struct dentry *try_lookup_one_len(const char *, struct dentry *, int);
 extern struct dentry *lookup_one_len(const char *, struct dentry *, int);
 extern struct dentry *lookup_one_len_unlocked(const char *, struct dentry *, int);
 extern struct dentry *lookup_positive_unlocked(const char *, struct dentry *, int);
+struct dentry *lookup_one(struct user_namespace *, const char *, struct dentry *, int);
 
 extern int follow_down_one(struct path *);
 extern int follow_down(struct path *);
diff --git a/include/trace/events/btrfs.h b/include/trace/events/btrfs.h
index b671b1f2ce0f..8f58fd95efc7 100644
--- a/include/trace/events/btrfs.h
+++ b/include/trace/events/btrfs.h
@@ -94,6 +94,7 @@ struct btrfs_space_info;
 	EM( FLUSH_DELAYED_ITEMS,	"FLUSH_DELAYED_ITEMS")		\
 	EM( FLUSH_DELALLOC,		"FLUSH_DELALLOC")		\
 	EM( FLUSH_DELALLOC_WAIT,	"FLUSH_DELALLOC_WAIT")		\
+	EM( FLUSH_DELALLOC_FULL,	"FLUSH_DELALLOC_FULL")		\
 	EM( FLUSH_DELAYED_REFS_NR,	"FLUSH_DELAYED_REFS_NR")	\
 	EM( FLUSH_DELAYED_REFS,		"FLUSH_ELAYED_REFS")		\
 	EM( ALLOC_CHUNK,		"ALLOC_CHUNK")			\
@@ -2037,7 +2038,7 @@ TRACE_EVENT(btrfs_convert_extent_bit,
 );
 
 DECLARE_EVENT_CLASS(btrfs_dump_space_info,
-	TP_PROTO(const struct btrfs_fs_info *fs_info,
+	TP_PROTO(struct btrfs_fs_info *fs_info,
 		 const struct btrfs_space_info *sinfo),
 
 	TP_ARGS(fs_info, sinfo),
@@ -2057,6 +2058,8 @@ DECLARE_EVENT_CLASS(btrfs_dump_space_info,
 		__field(	u64,	delayed_refs_reserved	)
 		__field(	u64,	delayed_reserved	)
 		__field(	u64,	free_chunk_space	)
+		__field(	u64,	delalloc_bytes		)
+		__field(	u64,	ordered_bytes		)
 	),
 
 	TP_fast_assign_btrfs(fs_info,
@@ -2074,6 +2077,8 @@ DECLARE_EVENT_CLASS(btrfs_dump_space_info,
 		__entry->delayed_refs_reserved	=	fs_info->delayed_refs_rsv.reserved;
 		__entry->delayed_reserved	=	fs_info->delayed_block_rsv.reserved;
 		__entry->free_chunk_space	=	atomic64_read(&fs_info->free_chunk_space);
+		__entry->delalloc_bytes		=	percpu_counter_sum_positive(&fs_info->delalloc_bytes);
+		__entry->ordered_bytes		=	percpu_counter_sum_positive(&fs_info->ordered_bytes);
 	),
 
 	TP_printk_btrfs("flags=%s total_bytes=%llu bytes_used=%llu "
@@ -2081,7 +2086,8 @@ DECLARE_EVENT_CLASS(btrfs_dump_space_info,
 			"bytes_may_use=%llu bytes_readonly=%llu "
 			"reclaim_size=%llu clamp=%d global_reserved=%llu "
 			"trans_reserved=%llu delayed_refs_reserved=%llu "
-			"delayed_reserved=%llu chunk_free_space=%llu",
+			"delayed_reserved=%llu chunk_free_space=%llu "
+			"delalloc_bytes=%llu ordered_bytes=%llu",
 			__print_flags(__entry->flags, "|", BTRFS_GROUP_FLAGS),
 			__entry->total_bytes, __entry->bytes_used,
 			__entry->bytes_pinned, __entry->bytes_reserved,
@@ -2089,11 +2095,18 @@ DECLARE_EVENT_CLASS(btrfs_dump_space_info,
 			__entry->reclaim_size, __entry->clamp,
 			__entry->global_reserved, __entry->trans_reserved,
 			__entry->delayed_refs_reserved,
-			__entry->delayed_reserved, __entry->free_chunk_space)
+			__entry->delayed_reserved, __entry->free_chunk_space,
+			__entry->delalloc_bytes, __entry->ordered_bytes)
 );
 
 DEFINE_EVENT(btrfs_dump_space_info, btrfs_done_preemptive_reclaim,
-	TP_PROTO(const struct btrfs_fs_info *fs_info,
+	TP_PROTO(struct btrfs_fs_info *fs_info,
+		 const struct btrfs_space_info *sinfo),
+	TP_ARGS(fs_info, sinfo)
+);
+
+DEFINE_EVENT(btrfs_dump_space_info, btrfs_fail_all_tickets,
+	TP_PROTO(struct btrfs_fs_info *fs_info,
 		 const struct btrfs_space_info *sinfo),
 	TP_ARGS(fs_info, sinfo)
 );
diff --git a/include/uapi/linux/btrfs.h b/include/uapi/linux/btrfs.h
index 22cd037123fa..d7d3cfead056 100644
--- a/include/uapi/linux/btrfs.h
+++ b/include/uapi/linux/btrfs.h
@@ -288,6 +288,7 @@ struct btrfs_ioctl_fs_info_args {
  * first mount when booting older kernel versions.
  */
 #define BTRFS_FEATURE_COMPAT_RO_FREE_SPACE_TREE_VALID	(1ULL << 1)
+#define BTRFS_FEATURE_COMPAT_RO_VERITY			(1ULL << 2)
 
 #define BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF	(1ULL << 0)
 #define BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL	(1ULL << 1)
diff --git a/include/uapi/linux/btrfs_tree.h b/include/uapi/linux/btrfs_tree.h
index ccdb40fe40dc..e1c4c732aaba 100644
--- a/include/uapi/linux/btrfs_tree.h
+++ b/include/uapi/linux/btrfs_tree.h
@@ -118,6 +118,29 @@
 #define BTRFS_INODE_REF_KEY		12
 #define BTRFS_INODE_EXTREF_KEY		13
 #define BTRFS_XATTR_ITEM_KEY		24
+
+/*
+ * fs verity items are stored under two different key types on disk.
+ * The descriptor items:
+ * [ inode objectid, BTRFS_VERITY_DESC_ITEM_KEY, offset ]
+ *
+ * At offset 0, we store a btrfs_verity_descriptor_item which tracks the size
+ * of the descriptor item and some extra data for encryption.
+ * Starting at offset 1, these hold the generic fs verity descriptor.  The
+ * latter are opaque to btrfs, we just read and write them as a blob for the
+ * higher level verity code.  The most common descriptor size is 256 bytes.
+ *
+ * The merkle tree items:
+ * [ inode objectid, BTRFS_VERITY_MERKLE_ITEM_KEY, offset ]
+ *
+ * These also start at offset 0, and correspond to the merkle tree bytes.  When
+ * fsverity asks for page 0 of the merkle tree, we pull up one page starting at
+ * offset 0 for this key type.  These are also opaque to btrfs, we're blindly
+ * storing whatever fsverity sends down.
+ */
+#define BTRFS_VERITY_DESC_ITEM_KEY	36
+#define BTRFS_VERITY_MERKLE_ITEM_KEY	37
+
 #define BTRFS_ORPHAN_ITEM_KEY		48
 /* reserve 2-15 close to the inode for later flexibility */
 
@@ -991,4 +1014,16 @@ struct btrfs_qgroup_limit_item {
 	__le64 rsv_excl;
 } __attribute__ ((__packed__));
 
+struct btrfs_verity_descriptor_item {
+	/* Size of the verity descriptor in bytes */
+	__le64 size;
+	/*
+	 * When we implement support for fscrypt, we will need to encrypt the
+	 * Merkle tree for encrypted verity files. These 128 bits are for the
+	 * eventual storage of an fscrypt initialization vector.
+	 */
+	__le64 reserved[2];
+	__u8 encryption;
+} __attribute__ ((__packed__));
+
 #endif /* _BTRFS_CTREE_H_ */
diff --git a/mm/filemap.c b/mm/filemap.c
index 0fad08331cf4..920e8dc03251 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -380,6 +380,32 @@ static int filemap_check_and_keep_errors(struct address_space *mapping)
 }
 
 /**
+ * filemap_fdatawrite_wbc - start writeback on mapping dirty pages in range
+ * @mapping:	address space structure to write
+ * @wbc:	the writeback_control controlling the writeout
+ *
+ * Call writepages on the mapping using the provided wbc to control the
+ * writeout.
+ *
+ * Return: %0 on success, negative error code otherwise.
+ */
+int filemap_fdatawrite_wbc(struct address_space *mapping,
+			   struct writeback_control *wbc)
+{
+	int ret;
+
+	if (!mapping_can_writeback(mapping) ||
+	    !mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
+		return 0;
+
+	wbc_attach_fdatawrite_inode(wbc, mapping->host);
+	ret = do_writepages(mapping, wbc);
+	wbc_detach_inode(wbc);
+	return ret;
+}
+EXPORT_SYMBOL(filemap_fdatawrite_wbc);
+
+/**
  * __filemap_fdatawrite_range - start writeback on mapping dirty pages in range
  * @mapping:	address space structure to write
  * @start:	offset in bytes where the range starts
@@ -399,7 +425,6 @@ static int filemap_check_and_keep_errors(struct address_space *mapping)
 int __filemap_fdatawrite_range(struct address_space *mapping, loff_t start,
 				loff_t end, int sync_mode)
 {
-	int ret;
 	struct writeback_control wbc = {
 		.sync_mode = sync_mode,
 		.nr_to_write = LONG_MAX,
@@ -407,14 +432,7 @@ int __filemap_fdatawrite_range(struct address_space *mapping, loff_t start,
 		.range_end = end,
 	};
 
-	if (!mapping_can_writeback(mapping) ||
-	    !mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
-		return 0;
-
-	wbc_attach_fdatawrite_inode(&wbc, mapping->host);
-	ret = do_writepages(mapping, &wbc);
-	wbc_detach_inode(&wbc);
-	return ret;
+	return filemap_fdatawrite_wbc(mapping, &wbc);
 }
 
 static inline int __filemap_fdatawrite(struct address_space *mapping,