1 files changed, 135 insertions, 155 deletions

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index a6d3f08bfff3..9cfc668f91f4 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -30,6 +30,7 @@
 #include "tree-checker.h"
 #include "space-info.h"
 #include "block-group.h"
+#include "discard.h"
 
 const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
 	[BTRFS_RAID_RAID10] = {
@@ -66,6 +67,7 @@ const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
 		.tolerated_failures = 2,
 		.devs_increment	= 3,
 		.ncopies	= 3,
+		.nparity        = 0,
 		.raid_name	= "raid1c3",
 		.bg_flag	= BTRFS_BLOCK_GROUP_RAID1C3,
 		.mindev_error	= BTRFS_ERROR_DEV_RAID1C3_MIN_NOT_MET,
@@ -78,6 +80,7 @@ const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
 		.tolerated_failures = 3,
 		.devs_increment	= 4,
 		.ncopies	= 4,
+		.nparity        = 0,
 		.raid_name	= "raid1c4",
 		.bg_flag	= BTRFS_BLOCK_GROUP_RAID1C4,
 		.mindev_error	= BTRFS_ERROR_DEV_RAID1C4_MIN_NOT_MET,
@@ -438,39 +441,6 @@ static noinline struct btrfs_fs_devices *find_fsid(
 
 	ASSERT(fsid);
 
-	if (metadata_fsid) {
-		/*
-		 * Handle scanned device having completed its fsid change but
-		 * belonging to a fs_devices that was created by first scanning
-		 * a device which didn't have its fsid/metadata_uuid changed
-		 * at all and the CHANGING_FSID_V2 flag set.
-		 */
-		list_for_each_entry(fs_devices, &fs_uuids, fs_list) {
-			if (fs_devices->fsid_change &&
-			    memcmp(metadata_fsid, fs_devices->fsid,
-				   BTRFS_FSID_SIZE) == 0 &&
-			    memcmp(fs_devices->fsid, fs_devices->metadata_uuid,
-				   BTRFS_FSID_SIZE) == 0) {
-				return fs_devices;
-			}
-		}
-		/*
-		 * Handle scanned device having completed its fsid change but
-		 * belonging to a fs_devices that was created by a device that
-		 * has an outdated pair of fsid/metadata_uuid and
-		 * CHANGING_FSID_V2 flag set.
-		 */
-		list_for_each_entry(fs_devices, &fs_uuids, fs_list) {
-			if (fs_devices->fsid_change &&
-			    memcmp(fs_devices->metadata_uuid,
-				   fs_devices->fsid, BTRFS_FSID_SIZE) != 0 &&
-			    memcmp(metadata_fsid, fs_devices->metadata_uuid,
-				   BTRFS_FSID_SIZE) == 0) {
-				return fs_devices;
-			}
-		}
-	}
-
 	/* Handle non-split brain cases */
 	list_for_each_entry(fs_devices, &fs_uuids, fs_list) {
 		if (metadata_fsid) {
@@ -486,6 +456,47 @@ static noinline struct btrfs_fs_devices *find_fsid(
 	return NULL;
 }
 
+static struct btrfs_fs_devices *find_fsid_with_metadata_uuid(
+				struct btrfs_super_block *disk_super)
+{
+
+	struct btrfs_fs_devices *fs_devices;
+
+	/*
+	 * Handle scanned device having completed its fsid change but
+	 * belonging to a fs_devices that was created by first scanning
+	 * a device which didn't have its fsid/metadata_uuid changed
+	 * at all and the CHANGING_FSID_V2 flag set.
+	 */
+	list_for_each_entry(fs_devices, &fs_uuids, fs_list) {
+		if (fs_devices->fsid_change &&
+		    memcmp(disk_super->metadata_uuid, fs_devices->fsid,
+			   BTRFS_FSID_SIZE) == 0 &&
+		    memcmp(fs_devices->fsid, fs_devices->metadata_uuid,
+			   BTRFS_FSID_SIZE) == 0) {
+			return fs_devices;
+		}
+	}
+	/*
+	 * Handle scanned device having completed its fsid change but
+	 * belonging to a fs_devices that was created by a device that
+	 * has an outdated pair of fsid/metadata_uuid and
+	 * CHANGING_FSID_V2 flag set.
+	 */
+	list_for_each_entry(fs_devices, &fs_uuids, fs_list) {
+		if (fs_devices->fsid_change &&
+		    memcmp(fs_devices->metadata_uuid,
+			   fs_devices->fsid, BTRFS_FSID_SIZE) != 0 &&
+		    memcmp(disk_super->metadata_uuid, fs_devices->metadata_uuid,
+			   BTRFS_FSID_SIZE) == 0) {
+			return fs_devices;
+		}
+	}
+
+	return find_fsid(disk_super->fsid, disk_super->metadata_uuid);
+}
+
+
 static int
 btrfs_get_bdev_and_sb(const char *device_path, fmode_t flags, void *holder,
 		      int flush, struct block_device **bdev,
@@ -669,7 +680,9 @@ error_brelse:
 
 /*
  * Handle scanned device having its CHANGING_FSID_V2 flag set and the fs_devices
- * being created with a disk that has already completed its fsid change.
+ * being created with a disk that has already completed its fsid change. Such
+ * disk can belong to an fs which has its FSID changed or to one which doesn't.
+ * Handle both cases here.
  */
 static struct btrfs_fs_devices *find_fsid_inprogress(
 					struct btrfs_super_block *disk_super)
@@ -685,7 +698,7 @@ static struct btrfs_fs_devices *find_fsid_inprogress(
 		}
 	}
 
-	return NULL;
+	return find_fsid(disk_super->fsid, NULL);
 }
 
 
@@ -697,17 +710,54 @@ static struct btrfs_fs_devices *find_fsid_changed(
 	/*
 	 * Handles the case where scanned device is part of an fs that had
 	 * multiple successful changes of FSID but curently device didn't
-	 * observe it. Meaning our fsid will be different than theirs.
+	 * observe it. Meaning our fsid will be different than theirs. We need
+	 * to handle two subcases :
+	 *  1 - The fs still continues to have different METADATA/FSID uuids.
+	 *  2 - The fs is switched back to its original FSID (METADATA/FSID
+	 *  are equal).
 	 */
 	list_for_each_entry(fs_devices, &fs_uuids, fs_list) {
+		/* Changed UUIDs */
 		if (memcmp(fs_devices->metadata_uuid, fs_devices->fsid,
 			   BTRFS_FSID_SIZE) != 0 &&
 		    memcmp(fs_devices->metadata_uuid, disk_super->metadata_uuid,
 			   BTRFS_FSID_SIZE) == 0 &&
 		    memcmp(fs_devices->fsid, disk_super->fsid,
-			   BTRFS_FSID_SIZE) != 0) {
+			   BTRFS_FSID_SIZE) != 0)
+			return fs_devices;
+
+		/* Unchanged UUIDs */
+		if (memcmp(fs_devices->metadata_uuid, fs_devices->fsid,
+			   BTRFS_FSID_SIZE) == 0 &&
+		    memcmp(fs_devices->fsid, disk_super->metadata_uuid,
+			   BTRFS_FSID_SIZE) == 0)
+			return fs_devices;
+	}
+
+	return NULL;
+}
+
+static struct btrfs_fs_devices *find_fsid_reverted_metadata(
+				struct btrfs_super_block *disk_super)
+{
+	struct btrfs_fs_devices *fs_devices;
+
+	/*
+	 * Handle the case where the scanned device is part of an fs whose last
+	 * metadata UUID change reverted it to the original FSID. At the same
+	 * time * fs_devices was first created by another constitutent device
+	 * which didn't fully observe the operation. This results in an
+	 * btrfs_fs_devices created with metadata/fsid different AND
+	 * btrfs_fs_devices::fsid_change set AND the metadata_uuid of the
+	 * fs_devices equal to the FSID of the disk.
+	 */
+	list_for_each_entry(fs_devices, &fs_uuids, fs_list) {
+		if (memcmp(fs_devices->fsid, fs_devices->metadata_uuid,
+			   BTRFS_FSID_SIZE) != 0 &&
+		    memcmp(fs_devices->metadata_uuid, disk_super->fsid,
+			   BTRFS_FSID_SIZE) == 0 &&
+		    fs_devices->fsid_change)
 			return fs_devices;
-		}
 	}
 
 	return NULL;
@@ -734,24 +784,16 @@ static noinline struct btrfs_device *device_list_add(const char *path,
 					BTRFS_SUPER_FLAG_CHANGING_FSID_V2);
 
 	if (fsid_change_in_progress) {
-		if (!has_metadata_uuid) {
-			/*
-			 * When we have an image which has CHANGING_FSID_V2 set
-			 * it might belong to either a filesystem which has
-			 * disks with completed fsid change or it might belong
-			 * to fs with no UUID changes in effect, handle both.
-			 */
+		if (!has_metadata_uuid)
 			fs_devices = find_fsid_inprogress(disk_super);
-			if (!fs_devices)
-				fs_devices = find_fsid(disk_super->fsid, NULL);
-		} else {
+		else
 			fs_devices = find_fsid_changed(disk_super);
-		}
 	} else if (has_metadata_uuid) {
-		fs_devices = find_fsid(disk_super->fsid,
-				       disk_super->metadata_uuid);
+		fs_devices = find_fsid_with_metadata_uuid(disk_super);
 	} else {
-		fs_devices = find_fsid(disk_super->fsid, NULL);
+		fs_devices = find_fsid_reverted_metadata(disk_super);
+		if (!fs_devices)
+			fs_devices = find_fsid(disk_super->fsid, NULL);
 	}
 
 
@@ -781,12 +823,18 @@ static noinline struct btrfs_device *device_list_add(const char *path,
 		 * a device which had the CHANGING_FSID_V2 flag then replace the
 		 * metadata_uuid/fsid values of the fs_devices.
 		 */
-		if (has_metadata_uuid && fs_devices->fsid_change &&
+		if (fs_devices->fsid_change &&
 		    found_transid > fs_devices->latest_generation) {
 			memcpy(fs_devices->fsid, disk_super->fsid,
 					BTRFS_FSID_SIZE);
-			memcpy(fs_devices->metadata_uuid,
-					disk_super->metadata_uuid, BTRFS_FSID_SIZE);
+
+			if (has_metadata_uuid)
+				memcpy(fs_devices->metadata_uuid,
+				       disk_super->metadata_uuid,
+				       BTRFS_FSID_SIZE);
+			else
+				memcpy(fs_devices->metadata_uuid,
+				       disk_super->fsid, BTRFS_FSID_SIZE);
 
 			fs_devices->fsid_change = false;
 		}
@@ -1064,11 +1112,6 @@ static void btrfs_close_bdev(struct btrfs_device *device)
 static void btrfs_close_one_device(struct btrfs_device *device)
 {
 	struct btrfs_fs_devices *fs_devices = device->fs_devices;
-	struct btrfs_device *new_device;
-	struct rcu_string *name;
-
-	if (device->bdev)
-		fs_devices->open_devices--;
 
 	if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state) &&
 	    device->devid != BTRFS_DEV_REPLACE_DEVID) {
@@ -1080,23 +1123,22 @@ static void btrfs_close_one_device(struct btrfs_device *device)
 		fs_devices->missing_devices--;
 
 	btrfs_close_bdev(device);
-
-	new_device = btrfs_alloc_device(NULL, &device->devid,
-					device->uuid);
-	BUG_ON(IS_ERR(new_device)); /* -ENOMEM */
-
-	/* Safe because we are under uuid_mutex */
-	if (device->name) {
-		name = rcu_string_strdup(device->name->str, GFP_NOFS);
-		BUG_ON(!name); /* -ENOMEM */
-		rcu_assign_pointer(new_device->name, name);
+	if (device->bdev) {
+		fs_devices->open_devices--;
+		device->bdev = NULL;
 	}
+	clear_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
 
-	list_replace_rcu(&device->dev_list, &new_device->dev_list);
-	new_device->fs_devices = device->fs_devices;
+	device->fs_info = NULL;
+	atomic_set(&device->dev_stats_ccnt, 0);
+	extent_io_tree_release(&device->alloc_state);
 
-	synchronize_rcu();
-	btrfs_free_device(device);
+	/* Verify the device is back in a pristine state  */
+	ASSERT(!test_bit(BTRFS_DEV_STATE_FLUSH_SENT, &device->dev_state));
+	ASSERT(!test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state));
+	ASSERT(list_empty(&device->dev_alloc_list));
+	ASSERT(list_empty(&device->post_commit_list));
+	ASSERT(atomic_read(&device->reada_in_flight) == 0);
 }
 
 static int close_fs_devices(struct btrfs_fs_devices *fs_devices)
@@ -2130,7 +2172,6 @@ void btrfs_destroy_dev_replace_tgtdev(struct btrfs_device *tgtdev)
 {
 	struct btrfs_fs_devices *fs_devices = tgtdev->fs_info->fs_devices;
 
-	WARN_ON(!tgtdev);
 	mutex_lock(&fs_devices->device_list_mutex);
 
 	btrfs_sysfs_rm_device_link(fs_devices, tgtdev);
@@ -2875,6 +2916,7 @@ static int btrfs_relocate_chunk(struct btrfs_fs_info *fs_info, u64 chunk_offset)
 {
 	struct btrfs_root *root = fs_info->chunk_root;
 	struct btrfs_trans_handle *trans;
+	struct btrfs_block_group *block_group;
 	int ret;
 
 	/*
@@ -2898,6 +2940,12 @@ static int btrfs_relocate_chunk(struct btrfs_fs_info *fs_info, u64 chunk_offset)
 	if (ret)
 		return ret;
 
+	block_group = btrfs_lookup_block_group(fs_info, chunk_offset);
+	if (!block_group)
+		return -ENOENT;
+	btrfs_discard_cancel_work(&fs_info->discard_ctl, block_group);
+	btrfs_put_block_group(block_group);
+
 	trans = btrfs_start_trans_remove_block_group(root->fs_info,
 						     chunk_offset);
 	if (IS_ERR(trans)) {
@@ -3881,7 +3929,11 @@ int btrfs_balance(struct btrfs_fs_info *fs_info,
 		}
 	}
 
-	num_devices = btrfs_num_devices(fs_info);
+	/*
+	 * rw_devices will not change at the moment, device add/delete/replace
+	 * are excluded by EXCL_OP
+	 */
+	num_devices = fs_info->fs_devices->rw_devices;
 
 	/*
 	 * SINGLE profile on-disk has no profile bit, but in-memory we have a
@@ -6107,75 +6159,6 @@ int btrfs_map_sblock(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
 	return __btrfs_map_block(fs_info, op, logical, length, bbio_ret, 0, 1);
 }
 
-int btrfs_rmap_block(struct btrfs_fs_info *fs_info, u64 chunk_start,
-		     u64 physical, u64 **logical, int *naddrs, int *stripe_len)
-{
-	struct extent_map *em;
-	struct map_lookup *map;
-	u64 *buf;
-	u64 bytenr;
-	u64 length;
-	u64 stripe_nr;
-	u64 rmap_len;
-	int i, j, nr = 0;
-
-	em = btrfs_get_chunk_map(fs_info, chunk_start, 1);
-	if (IS_ERR(em))
-		return -EIO;
-
-	map = em->map_lookup;
-	length = em->len;
-	rmap_len = map->stripe_len;
-
-	if (map->type & BTRFS_BLOCK_GROUP_RAID10)
-		length = div_u64(length, map->num_stripes / map->sub_stripes);
-	else if (map->type & BTRFS_BLOCK_GROUP_RAID0)
-		length = div_u64(length, map->num_stripes);
-	else if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
-		length = div_u64(length, nr_data_stripes(map));
-		rmap_len = map->stripe_len * nr_data_stripes(map);
-	}
-
-	buf = kcalloc(map->num_stripes, sizeof(u64), GFP_NOFS);
-	BUG_ON(!buf); /* -ENOMEM */
-
-	for (i = 0; i < map->num_stripes; i++) {
-		if (map->stripes[i].physical > physical ||
-		    map->stripes[i].physical + length <= physical)
-			continue;
-
-		stripe_nr = physical - map->stripes[i].physical;
-		stripe_nr = div64_u64(stripe_nr, map->stripe_len);
-
-		if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
-			stripe_nr = stripe_nr * map->num_stripes + i;
-			stripe_nr = div_u64(stripe_nr, map->sub_stripes);
-		} else if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
-			stripe_nr = stripe_nr * map->num_stripes + i;
-		} /* else if RAID[56], multiply by nr_data_stripes().
-		   * Alternatively, just use rmap_len below instead of
-		   * map->stripe_len */
-
-		bytenr = chunk_start + stripe_nr * rmap_len;
-		WARN_ON(nr >= map->num_stripes);
-		for (j = 0; j < nr; j++) {
-			if (buf[j] == bytenr)
-				break;
-		}
-		if (j == nr) {
-			WARN_ON(nr >= map->num_stripes);
-			buf[nr++] = bytenr;
-		}
-	}
-
-	*logical = buf;
-	*naddrs = nr;
-	*stripe_len = rmap_len;
-
-	free_extent_map(em);
-	return 0;
-}
-
 static inline void btrfs_end_bbio(struct btrfs_bio *bbio, struct bio *bio)
 {
 	bio->bi_private = bbio->private;
@@ -6476,19 +6459,14 @@ 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;
 
-	switch (type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
-	case BTRFS_BLOCK_GROUP_RAID5:
-		data_stripes = num_stripes - 1;
-		break;
-	case BTRFS_BLOCK_GROUP_RAID6:
-		data_stripes = num_stripes - 2;
-		break;
-	default:
+	if (nparity)
+		data_stripes = num_stripes - nparity;
+	else
 		data_stripes = num_stripes / ncopies;
-		break;
-	}
+
 	return div_u64(chunk_len, data_stripes);
 }
 
@@ -7327,6 +7305,8 @@ int btrfs_get_dev_stats(struct btrfs_fs_info *fs_info,
 			else
 				btrfs_dev_stat_set(dev, i, 0);
 		}
+		btrfs_info(fs_info, "device stats zeroed by %s (%d)",
+			   current->comm, task_pid_nr(current));
 	} else {
 		for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
 			if (stats->nr_items > i)