1 files changed, 7 insertions, 672 deletions

diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index 6702896cdb8f..3be1456b5116 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -188,32 +188,6 @@ struct scrub_ctx {
 	refcount_t              refs;
 };
 
-struct scrub_fixup_nodatasum {
-	struct scrub_ctx	*sctx;
-	struct btrfs_device	*dev;
-	u64			logical;
-	struct btrfs_root	*root;
-	struct btrfs_work	work;
-	int			mirror_num;
-};
-
-struct scrub_nocow_inode {
-	u64			inum;
-	u64			offset;
-	u64			root;
-	struct list_head	list;
-};
-
-struct scrub_copy_nocow_ctx {
-	struct scrub_ctx	*sctx;
-	u64			logical;
-	u64			len;
-	int			mirror_num;
-	u64			physical_for_dev_replace;
-	struct list_head	inodes;
-	struct btrfs_work	work;
-};
-
 struct scrub_warning {
 	struct btrfs_path	*path;
 	u64			extent_item_size;
@@ -232,8 +206,6 @@ struct full_stripe_lock {
 
 static void scrub_pending_bio_inc(struct scrub_ctx *sctx);
 static void scrub_pending_bio_dec(struct scrub_ctx *sctx);
-static void scrub_pending_trans_workers_inc(struct scrub_ctx *sctx);
-static void scrub_pending_trans_workers_dec(struct scrub_ctx *sctx);
 static int scrub_handle_errored_block(struct scrub_block *sblock_to_check);
 static int scrub_setup_recheck_block(struct scrub_block *original_sblock,
 				     struct scrub_block *sblocks_for_recheck);
@@ -277,13 +249,6 @@ static int scrub_add_page_to_wr_bio(struct scrub_ctx *sctx,
 static void scrub_wr_submit(struct scrub_ctx *sctx);
 static void scrub_wr_bio_end_io(struct bio *bio);
 static void scrub_wr_bio_end_io_worker(struct btrfs_work *work);
-static int write_page_nocow(struct scrub_ctx *sctx,
-			    u64 physical_for_dev_replace, struct page *page);
-static int copy_nocow_pages_for_inode(u64 inum, u64 offset, u64 root,
-				      struct scrub_copy_nocow_ctx *ctx);
-static int copy_nocow_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
-			    int mirror_num, u64 physical_for_dev_replace);
-static void copy_nocow_pages_worker(struct btrfs_work *work);
 static void __scrub_blocked_if_needed(struct btrfs_fs_info *fs_info);
 static void scrub_blocked_if_needed(struct btrfs_fs_info *fs_info);
 static void scrub_put_ctx(struct scrub_ctx *sctx);
@@ -555,60 +520,6 @@ out:
 	return ret;
 }
 
-/*
- * used for workers that require transaction commits (i.e., for the
- * NOCOW case)
- */
-static void scrub_pending_trans_workers_inc(struct scrub_ctx *sctx)
-{
-	struct btrfs_fs_info *fs_info = sctx->fs_info;
-
-	refcount_inc(&sctx->refs);
-	/*
-	 * increment scrubs_running to prevent cancel requests from
-	 * completing as long as a worker is running. we must also
-	 * increment scrubs_paused to prevent deadlocking on pause
-	 * requests used for transactions commits (as the worker uses a
-	 * transaction context). it is safe to regard the worker
-	 * as paused for all matters practical. effectively, we only
-	 * avoid cancellation requests from completing.
-	 */
-	mutex_lock(&fs_info->scrub_lock);
-	atomic_inc(&fs_info->scrubs_running);
-	atomic_inc(&fs_info->scrubs_paused);
-	mutex_unlock(&fs_info->scrub_lock);
-
-	/*
-	 * check if @scrubs_running=@scrubs_paused condition
-	 * inside wait_event() is not an atomic operation.
-	 * which means we may inc/dec @scrub_running/paused
-	 * at any time. Let's wake up @scrub_pause_wait as
-	 * much as we can to let commit transaction blocked less.
-	 */
-	wake_up(&fs_info->scrub_pause_wait);
-
-	atomic_inc(&sctx->workers_pending);
-}
-
-/* used for workers that require transaction commits */
-static void scrub_pending_trans_workers_dec(struct scrub_ctx *sctx)
-{
-	struct btrfs_fs_info *fs_info = sctx->fs_info;
-
-	/*
-	 * see scrub_pending_trans_workers_inc() why we're pretending
-	 * to be paused in the scrub counters
-	 */
-	mutex_lock(&fs_info->scrub_lock);
-	atomic_dec(&fs_info->scrubs_running);
-	atomic_dec(&fs_info->scrubs_paused);
-	mutex_unlock(&fs_info->scrub_lock);
-	atomic_dec(&sctx->workers_pending);
-	wake_up(&fs_info->scrub_pause_wait);
-	wake_up(&sctx->list_wait);
-	scrub_put_ctx(sctx);
-}
-
 static void scrub_free_csums(struct scrub_ctx *sctx)
 {
 	while (!list_empty(&sctx->csum_list)) {
@@ -882,194 +793,6 @@ out:
 	btrfs_free_path(path);
 }
 
-static int scrub_fixup_readpage(u64 inum, u64 offset, u64 root, void *fixup_ctx)
-{
-	struct page *page = NULL;
-	unsigned long index;
-	struct scrub_fixup_nodatasum *fixup = fixup_ctx;
-	int ret;
-	int corrected = 0;
-	struct btrfs_key key;
-	struct inode *inode = NULL;
-	struct btrfs_fs_info *fs_info;
-	u64 end = offset + PAGE_SIZE - 1;
-	struct btrfs_root *local_root;
-	int srcu_index;
-
-	key.objectid = root;
-	key.type = BTRFS_ROOT_ITEM_KEY;
-	key.offset = (u64)-1;
-
-	fs_info = fixup->root->fs_info;
-	srcu_index = srcu_read_lock(&fs_info->subvol_srcu);
-
-	local_root = btrfs_read_fs_root_no_name(fs_info, &key);
-	if (IS_ERR(local_root)) {
-		srcu_read_unlock(&fs_info->subvol_srcu, srcu_index);
-		return PTR_ERR(local_root);
-	}
-
-	key.type = BTRFS_INODE_ITEM_KEY;
-	key.objectid = inum;
-	key.offset = 0;
-	inode = btrfs_iget(fs_info->sb, &key, local_root, NULL);
-	srcu_read_unlock(&fs_info->subvol_srcu, srcu_index);
-	if (IS_ERR(inode))
-		return PTR_ERR(inode);
-
-	index = offset >> PAGE_SHIFT;
-
-	page = find_or_create_page(inode->i_mapping, index, GFP_NOFS);
-	if (!page) {
-		ret = -ENOMEM;
-		goto out;
-	}
-
-	if (PageUptodate(page)) {
-		if (PageDirty(page)) {
-			/*
-			 * we need to write the data to the defect sector. the
-			 * data that was in that sector is not in memory,
-			 * because the page was modified. we must not write the
-			 * modified page to that sector.
-			 *
-			 * TODO: what could be done here: wait for the delalloc
-			 *       runner to write out that page (might involve
-			 *       COW) and see whether the sector is still
-			 *       referenced afterwards.
-			 *
-			 * For the meantime, we'll treat this error
-			 * incorrectable, although there is a chance that a
-			 * later scrub will find the bad sector again and that
-			 * there's no dirty page in memory, then.
-			 */
-			ret = -EIO;
-			goto out;
-		}
-		ret = repair_io_failure(fs_info, inum, offset, PAGE_SIZE,
-					fixup->logical, page,
-					offset - page_offset(page),
-					fixup->mirror_num);
-		unlock_page(page);
-		corrected = !ret;
-	} else {
-		/*
-		 * we need to get good data first. the general readpage path
-		 * will call repair_io_failure for us, we just have to make
-		 * sure we read the bad mirror.
-		 */
-		ret = set_extent_bits(&BTRFS_I(inode)->io_tree, offset, end,
-					EXTENT_DAMAGED);
-		if (ret) {
-			/* set_extent_bits should give proper error */
-			WARN_ON(ret > 0);
-			if (ret > 0)
-				ret = -EFAULT;
-			goto out;
-		}
-
-		ret = extent_read_full_page(&BTRFS_I(inode)->io_tree, page,
-						btrfs_get_extent,
-						fixup->mirror_num);
-		wait_on_page_locked(page);
-
-		corrected = !test_range_bit(&BTRFS_I(inode)->io_tree, offset,
-						end, EXTENT_DAMAGED, 0, NULL);
-		if (!corrected)
-			clear_extent_bits(&BTRFS_I(inode)->io_tree, offset, end,
-						EXTENT_DAMAGED);
-	}
-
-out:
-	if (page)
-		put_page(page);
-
-	iput(inode);
-
-	if (ret < 0)
-		return ret;
-
-	if (ret == 0 && corrected) {
-		/*
-		 * we only need to call readpage for one of the inodes belonging
-		 * to this extent. so make iterate_extent_inodes stop
-		 */
-		return 1;
-	}
-
-	return -EIO;
-}
-
-static void scrub_fixup_nodatasum(struct btrfs_work *work)
-{
-	struct btrfs_fs_info *fs_info;
-	int ret;
-	struct scrub_fixup_nodatasum *fixup;
-	struct scrub_ctx *sctx;
-	struct btrfs_trans_handle *trans = NULL;
-	struct btrfs_path *path;
-	int uncorrectable = 0;
-
-	fixup = container_of(work, struct scrub_fixup_nodatasum, work);
-	sctx = fixup->sctx;
-	fs_info = fixup->root->fs_info;
-
-	path = btrfs_alloc_path();
-	if (!path) {
-		spin_lock(&sctx->stat_lock);
-		++sctx->stat.malloc_errors;
-		spin_unlock(&sctx->stat_lock);
-		uncorrectable = 1;
-		goto out;
-	}
-
-	trans = btrfs_join_transaction(fixup->root);
-	if (IS_ERR(trans)) {
-		uncorrectable = 1;
-		goto out;
-	}
-
-	/*
-	 * the idea is to trigger a regular read through the standard path. we
-	 * read a page from the (failed) logical address by specifying the
-	 * corresponding copynum of the failed sector. thus, that readpage is
-	 * expected to fail.
-	 * that is the point where on-the-fly error correction will kick in
-	 * (once it's finished) and rewrite the failed sector if a good copy
-	 * can be found.
-	 */
-	ret = iterate_inodes_from_logical(fixup->logical, fs_info, path,
-					  scrub_fixup_readpage, fixup, false);
-	if (ret < 0) {
-		uncorrectable = 1;
-		goto out;
-	}
-	WARN_ON(ret != 1);
-
-	spin_lock(&sctx->stat_lock);
-	++sctx->stat.corrected_errors;
-	spin_unlock(&sctx->stat_lock);
-
-out:
-	if (trans && !IS_ERR(trans))
-		btrfs_end_transaction(trans);
-	if (uncorrectable) {
-		spin_lock(&sctx->stat_lock);
-		++sctx->stat.uncorrectable_errors;
-		spin_unlock(&sctx->stat_lock);
-		btrfs_dev_replace_stats_inc(
-			&fs_info->dev_replace.num_uncorrectable_read_errors);
-		btrfs_err_rl_in_rcu(fs_info,
-		    "unable to fixup (nodatasum) error at logical %llu on dev %s",
-			fixup->logical, rcu_str_deref(fixup->dev->name));
-	}
-
-	btrfs_free_path(path);
-	kfree(fixup);
-
-	scrub_pending_trans_workers_dec(sctx);
-}
-
 static inline void scrub_get_recover(struct scrub_recover *recover)
 {
 	refcount_inc(&recover->refs);
@@ -1264,42 +987,6 @@ static int scrub_handle_errored_block(struct scrub_block *sblock_to_check)
 	}
 
 	/*
-	 * NOTE: Even for nodatasum case, it's still possible that it's a
-	 * compressed data extent, thus scrub_fixup_nodatasum(), which write
-	 * inode page cache onto disk, could cause serious data corruption.
-	 *
-	 * So here we could only read from disk, and hope our recovery could
-	 * reach disk before the newer write.
-	 */
-	if (0 && !is_metadata && !have_csum) {
-		struct scrub_fixup_nodatasum *fixup_nodatasum;
-
-		WARN_ON(sctx->is_dev_replace);
-
-		/*
-		 * !is_metadata and !have_csum, this means that the data
-		 * might not be COWed, that it might be modified
-		 * concurrently. The general strategy to work on the
-		 * commit root does not help in the case when COW is not
-		 * used.
-		 */
-		fixup_nodatasum = kzalloc(sizeof(*fixup_nodatasum), GFP_NOFS);
-		if (!fixup_nodatasum)
-			goto did_not_correct_error;
-		fixup_nodatasum->sctx = sctx;
-		fixup_nodatasum->dev = dev;
-		fixup_nodatasum->logical = logical;
-		fixup_nodatasum->root = fs_info->extent_root;
-		fixup_nodatasum->mirror_num = failed_mirror_index + 1;
-		scrub_pending_trans_workers_inc(sctx);
-		btrfs_init_work(&fixup_nodatasum->work, btrfs_scrub_helper,
-				scrub_fixup_nodatasum, NULL, NULL);
-		btrfs_queue_work(fs_info->scrub_workers,
-				 &fixup_nodatasum->work);
-		goto out;
-	}
-
-	/*
 	 * now build and submit the bios for the other mirrors, check
 	 * checksums.
 	 * First try to pick the mirror which is completely without I/O
@@ -1866,7 +1553,7 @@ static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad,
 		bio = btrfs_io_bio_alloc(1);
 		bio_set_dev(bio, page_bad->dev->bdev);
 		bio->bi_iter.bi_sector = page_bad->physical >> 9;
-		bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
+		bio->bi_opf = REQ_OP_WRITE;
 
 		ret = bio_add_page(bio, page_good->page, PAGE_SIZE, 0);
 		if (PAGE_SIZE != ret) {
@@ -1961,7 +1648,7 @@ again:
 		bio->bi_end_io = scrub_wr_bio_end_io;
 		bio_set_dev(bio, sbio->dev->bdev);
 		bio->bi_iter.bi_sector = sbio->physical >> 9;
-		bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
+		bio->bi_opf = REQ_OP_WRITE;
 		sbio->status = 0;
 	} else if (sbio->physical + sbio->page_count * PAGE_SIZE !=
 		   spage->physical_for_dev_replace ||
@@ -2361,7 +2048,7 @@ again:
 		bio->bi_end_io = scrub_bio_end_io;
 		bio_set_dev(bio, sbio->dev->bdev);
 		bio->bi_iter.bi_sector = sbio->physical >> 9;
-		bio_set_op_attrs(bio, REQ_OP_READ, 0);
+		bio->bi_opf = REQ_OP_READ;
 		sbio->status = 0;
 	} else if (sbio->physical + sbio->page_count * PAGE_SIZE !=
 		   spage->physical ||
@@ -2800,17 +2487,10 @@ static int scrub_extent(struct scrub_ctx *sctx, struct map_lookup *map,
 			have_csum = scrub_find_csum(sctx, logical, csum);
 			if (have_csum == 0)
 				++sctx->stat.no_csum;
-			if (0 && sctx->is_dev_replace && !have_csum) {
-				ret = copy_nocow_pages(sctx, logical, l,
-						       mirror_num,
-						      physical_for_dev_replace);
-				goto behind_scrub_pages;
-			}
 		}
 		ret = scrub_pages(sctx, logical, l, physical, dev, flags, gen,
 				  mirror_num, have_csum ? csum : NULL, 0,
 				  physical_for_dev_replace);
-behind_scrub_pages:
 		if (ret)
 			return ret;
 		len -= l;
@@ -3863,7 +3543,7 @@ int scrub_enumerate_chunks(struct scrub_ctx *sctx,
 		 * -> btrfs_scrub_pause()
 		 */
 		scrub_pause_on(fs_info);
-		ret = btrfs_inc_block_group_ro(fs_info, cache);
+		ret = btrfs_inc_block_group_ro(cache);
 		if (!ret && is_dev_replace) {
 			/*
 			 * If we are doing a device replace wait for any tasks
@@ -3982,14 +3662,7 @@ int scrub_enumerate_chunks(struct scrub_ctx *sctx,
 		if (!cache->removed && !cache->ro && cache->reserved == 0 &&
 		    btrfs_block_group_used(&cache->item) == 0) {
 			spin_unlock(&cache->lock);
-			spin_lock(&fs_info->unused_bgs_lock);
-			if (list_empty(&cache->bg_list)) {
-				btrfs_get_block_group(cache);
-				trace_btrfs_add_unused_block_group(cache);
-				list_add_tail(&cache->bg_list,
-					      &fs_info->unused_bgs);
-			}
-			spin_unlock(&fs_info->unused_bgs_lock);
+			btrfs_mark_bg_unused(cache);
 		} else {
 			spin_unlock(&cache->lock);
 		}
@@ -4072,10 +3745,6 @@ static noinline_for_stack int scrub_workers_get(struct btrfs_fs_info *fs_info,
 		if (!fs_info->scrub_wr_completion_workers)
 			goto fail_scrub_wr_completion_workers;
 
-		fs_info->scrub_nocow_workers =
-			btrfs_alloc_workqueue(fs_info, "scrubnc", flags, 1, 0);
-		if (!fs_info->scrub_nocow_workers)
-			goto fail_scrub_nocow_workers;
 		fs_info->scrub_parity_workers =
 			btrfs_alloc_workqueue(fs_info, "scrubparity", flags,
 					      max_active, 2);
@@ -4086,8 +3755,6 @@ static noinline_for_stack int scrub_workers_get(struct btrfs_fs_info *fs_info,
 	return 0;
 
 fail_scrub_parity_workers:
-	btrfs_destroy_workqueue(fs_info->scrub_nocow_workers);
-fail_scrub_nocow_workers:
 	btrfs_destroy_workqueue(fs_info->scrub_wr_completion_workers);
 fail_scrub_wr_completion_workers:
 	btrfs_destroy_workqueue(fs_info->scrub_workers);
@@ -4100,7 +3767,6 @@ static noinline_for_stack void scrub_workers_put(struct btrfs_fs_info *fs_info)
 	if (--fs_info->scrub_workers_refcnt == 0) {
 		btrfs_destroy_workqueue(fs_info->scrub_workers);
 		btrfs_destroy_workqueue(fs_info->scrub_wr_completion_workers);
-		btrfs_destroy_workqueue(fs_info->scrub_nocow_workers);
 		btrfs_destroy_workqueue(fs_info->scrub_parity_workers);
 	}
 	WARN_ON(fs_info->scrub_workers_refcnt < 0);
@@ -4113,7 +3779,6 @@ int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start,
 	struct scrub_ctx *sctx;
 	int ret;
 	struct btrfs_device *dev;
-	struct rcu_string *name;
 
 	if (btrfs_fs_closing(fs_info))
 		return -EINVAL;
@@ -4167,11 +3832,8 @@ int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start,
 	if (!is_dev_replace && !readonly &&
 	    !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state)) {
 		mutex_unlock(&fs_info->fs_devices->device_list_mutex);
-		rcu_read_lock();
-		name = rcu_dereference(dev->name);
-		btrfs_err(fs_info, "scrub: device %s is not writable",
-			  name->str);
-		rcu_read_unlock();
+		btrfs_err_in_rcu(fs_info, "scrub: device %s is not writable",
+				rcu_str_deref(dev->name));
 		return -EROFS;
 	}
 
@@ -4359,330 +4021,3 @@ static void scrub_remap_extent(struct btrfs_fs_info *fs_info,
 	*extent_dev = bbio->stripes[0].dev;
 	btrfs_put_bbio(bbio);
 }
-
-static int copy_nocow_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
-			    int mirror_num, u64 physical_for_dev_replace)
-{
-	struct scrub_copy_nocow_ctx *nocow_ctx;
-	struct btrfs_fs_info *fs_info = sctx->fs_info;
-
-	nocow_ctx = kzalloc(sizeof(*nocow_ctx), GFP_NOFS);
-	if (!nocow_ctx) {
-		spin_lock(&sctx->stat_lock);
-		sctx->stat.malloc_errors++;
-		spin_unlock(&sctx->stat_lock);
-		return -ENOMEM;
-	}
-
-	scrub_pending_trans_workers_inc(sctx);
-
-	nocow_ctx->sctx = sctx;
-	nocow_ctx->logical = logical;
-	nocow_ctx->len = len;
-	nocow_ctx->mirror_num = mirror_num;
-	nocow_ctx->physical_for_dev_replace = physical_for_dev_replace;
-	btrfs_init_work(&nocow_ctx->work, btrfs_scrubnc_helper,
-			copy_nocow_pages_worker, NULL, NULL);
-	INIT_LIST_HEAD(&nocow_ctx->inodes);
-	btrfs_queue_work(fs_info->scrub_nocow_workers,
-			 &nocow_ctx->work);
-
-	return 0;
-}
-
-static int record_inode_for_nocow(u64 inum, u64 offset, u64 root, void *ctx)
-{
-	struct scrub_copy_nocow_ctx *nocow_ctx = ctx;
-	struct scrub_nocow_inode *nocow_inode;
-
-	nocow_inode = kzalloc(sizeof(*nocow_inode), GFP_NOFS);
-	if (!nocow_inode)
-		return -ENOMEM;
-	nocow_inode->inum = inum;
-	nocow_inode->offset = offset;
-	nocow_inode->root = root;
-	list_add_tail(&nocow_inode->list, &nocow_ctx->inodes);
-	return 0;
-}
-
-#define COPY_COMPLETE 1
-
-static void copy_nocow_pages_worker(struct btrfs_work *work)
-{
-	struct scrub_copy_nocow_ctx *nocow_ctx =
-		container_of(work, struct scrub_copy_nocow_ctx, work);
-	struct scrub_ctx *sctx = nocow_ctx->sctx;
-	struct btrfs_fs_info *fs_info = sctx->fs_info;
-	struct btrfs_root *root = fs_info->extent_root;
-	u64 logical = nocow_ctx->logical;
-	u64 len = nocow_ctx->len;
-	int mirror_num = nocow_ctx->mirror_num;
-	u64 physical_for_dev_replace = nocow_ctx->physical_for_dev_replace;
-	int ret;
-	struct btrfs_trans_handle *trans = NULL;
-	struct btrfs_path *path;
-	int not_written = 0;
-
-	path = btrfs_alloc_path();
-	if (!path) {
-		spin_lock(&sctx->stat_lock);
-		sctx->stat.malloc_errors++;
-		spin_unlock(&sctx->stat_lock);
-		not_written = 1;
-		goto out;
-	}
-
-	trans = btrfs_join_transaction(root);
-	if (IS_ERR(trans)) {
-		not_written = 1;
-		goto out;
-	}
-
-	ret = iterate_inodes_from_logical(logical, fs_info, path,
-			record_inode_for_nocow, nocow_ctx, false);
-	if (ret != 0 && ret != -ENOENT) {
-		btrfs_warn(fs_info,
-			   "iterate_inodes_from_logical() failed: log %llu, phys %llu, len %llu, mir %u, ret %d",
-			   logical, physical_for_dev_replace, len, mirror_num,
-			   ret);
-		not_written = 1;
-		goto out;
-	}
-
-	btrfs_end_transaction(trans);
-	trans = NULL;
-	while (!list_empty(&nocow_ctx->inodes)) {
-		struct scrub_nocow_inode *entry;
-		entry = list_first_entry(&nocow_ctx->inodes,
-					 struct scrub_nocow_inode,
-					 list);
-		list_del_init(&entry->list);
-		ret = copy_nocow_pages_for_inode(entry->inum, entry->offset,
-						 entry->root, nocow_ctx);
-		kfree(entry);
-		if (ret == COPY_COMPLETE) {
-			ret = 0;
-			break;
-		} else if (ret) {
-			break;
-		}
-	}
-out:
-	while (!list_empty(&nocow_ctx->inodes)) {
-		struct scrub_nocow_inode *entry;
-		entry = list_first_entry(&nocow_ctx->inodes,
-					 struct scrub_nocow_inode,
-					 list);
-		list_del_init(&entry->list);
-		kfree(entry);
-	}
-	if (trans && !IS_ERR(trans))
-		btrfs_end_transaction(trans);
-	if (not_written)
-		btrfs_dev_replace_stats_inc(&fs_info->dev_replace.
-					    num_uncorrectable_read_errors);
-
-	btrfs_free_path(path);
-	kfree(nocow_ctx);
-
-	scrub_pending_trans_workers_dec(sctx);
-}
-
-static int check_extent_to_block(struct btrfs_inode *inode, u64 start, u64 len,
-				 u64 logical)
-{
-	struct extent_state *cached_state = NULL;
-	struct btrfs_ordered_extent *ordered;
-	struct extent_io_tree *io_tree;
-	struct extent_map *em;
-	u64 lockstart = start, lockend = start + len - 1;
-	int ret = 0;
-
-	io_tree = &inode->io_tree;
-
-	lock_extent_bits(io_tree, lockstart, lockend, &cached_state);
-	ordered = btrfs_lookup_ordered_range(inode, lockstart, len);
-	if (ordered) {
-		btrfs_put_ordered_extent(ordered);
-		ret = 1;
-		goto out_unlock;
-	}
-
-	em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
-	if (IS_ERR(em)) {
-		ret = PTR_ERR(em);
-		goto out_unlock;
-	}
-
-	/*
-	 * This extent does not actually cover the logical extent anymore,
-	 * move on to the next inode.
-	 */
-	if (em->block_start > logical ||
-	    em->block_start + em->block_len < logical + len ||
-	    test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
-		free_extent_map(em);
-		ret = 1;
-		goto out_unlock;
-	}
-	free_extent_map(em);
-
-out_unlock:
-	unlock_extent_cached(io_tree, lockstart, lockend, &cached_state);
-	return ret;
-}
-
-static int copy_nocow_pages_for_inode(u64 inum, u64 offset, u64 root,
-				      struct scrub_copy_nocow_ctx *nocow_ctx)
-{
-	struct btrfs_fs_info *fs_info = nocow_ctx->sctx->fs_info;
-	struct btrfs_key key;
-	struct inode *inode;
-	struct page *page;
-	struct btrfs_root *local_root;
-	struct extent_io_tree *io_tree;
-	u64 physical_for_dev_replace;
-	u64 nocow_ctx_logical;
-	u64 len = nocow_ctx->len;
-	unsigned long index;
-	int srcu_index;
-	int ret = 0;
-	int err = 0;
-
-	key.objectid = root;
-	key.type = BTRFS_ROOT_ITEM_KEY;
-	key.offset = (u64)-1;
-
-	srcu_index = srcu_read_lock(&fs_info->subvol_srcu);
-
-	local_root = btrfs_read_fs_root_no_name(fs_info, &key);
-	if (IS_ERR(local_root)) {
-		srcu_read_unlock(&fs_info->subvol_srcu, srcu_index);
-		return PTR_ERR(local_root);
-	}
-
-	key.type = BTRFS_INODE_ITEM_KEY;
-	key.objectid = inum;
-	key.offset = 0;
-	inode = btrfs_iget(fs_info->sb, &key, local_root, NULL);
-	srcu_read_unlock(&fs_info->subvol_srcu, srcu_index);
-	if (IS_ERR(inode))
-		return PTR_ERR(inode);
-
-	/* Avoid truncate/dio/punch hole.. */
-	inode_lock(inode);
-	inode_dio_wait(inode);
-
-	physical_for_dev_replace = nocow_ctx->physical_for_dev_replace;
-	io_tree = &BTRFS_I(inode)->io_tree;
-	nocow_ctx_logical = nocow_ctx->logical;
-
-	ret = check_extent_to_block(BTRFS_I(inode), offset, len,
-			nocow_ctx_logical);
-	if (ret) {
-		ret = ret > 0 ? 0 : ret;
-		goto out;
-	}
-
-	while (len >= PAGE_SIZE) {
-		index = offset >> PAGE_SHIFT;
-again:
-		page = find_or_create_page(inode->i_mapping, index, GFP_NOFS);
-		if (!page) {
-			btrfs_err(fs_info, "find_or_create_page() failed");
-			ret = -ENOMEM;
-			goto out;
-		}
-
-		if (PageUptodate(page)) {
-			if (PageDirty(page))
-				goto next_page;
-		} else {
-			ClearPageError(page);
-			err = extent_read_full_page(io_tree, page,
-							   btrfs_get_extent,
-							   nocow_ctx->mirror_num);
-			if (err) {
-				ret = err;
-				goto next_page;
-			}
-
-			lock_page(page);
-			/*
-			 * If the page has been remove from the page cache,
-			 * the data on it is meaningless, because it may be
-			 * old one, the new data may be written into the new
-			 * page in the page cache.
-			 */
-			if (page->mapping != inode->i_mapping) {
-				unlock_page(page);
-				put_page(page);
-				goto again;
-			}
-			if (!PageUptodate(page)) {
-				ret = -EIO;
-				goto next_page;
-			}
-		}
-
-		ret = check_extent_to_block(BTRFS_I(inode), offset, len,
-					    nocow_ctx_logical);
-		if (ret) {
-			ret = ret > 0 ? 0 : ret;
-			goto next_page;
-		}
-
-		err = write_page_nocow(nocow_ctx->sctx,
-				       physical_for_dev_replace, page);
-		if (err)
-			ret = err;
-next_page:
-		unlock_page(page);
-		put_page(page);
-
-		if (ret)
-			break;
-
-		offset += PAGE_SIZE;
-		physical_for_dev_replace += PAGE_SIZE;
-		nocow_ctx_logical += PAGE_SIZE;
-		len -= PAGE_SIZE;
-	}
-	ret = COPY_COMPLETE;
-out:
-	inode_unlock(inode);
-	iput(inode);
-	return ret;
-}
-
-static int write_page_nocow(struct scrub_ctx *sctx,
-			    u64 physical_for_dev_replace, struct page *page)
-{
-	struct bio *bio;
-	struct btrfs_device *dev;
-
-	dev = sctx->wr_tgtdev;
-	if (!dev)
-		return -EIO;
-	if (!dev->bdev) {
-		btrfs_warn_rl(dev->fs_info,
-			"scrub write_page_nocow(bdev == NULL) is unexpected");
-		return -EIO;
-	}
-	bio = btrfs_io_bio_alloc(1);
-	bio->bi_iter.bi_size = 0;
-	bio->bi_iter.bi_sector = physical_for_dev_replace >> 9;
-	bio_set_dev(bio, dev->bdev);
-	bio->bi_opf = REQ_OP_WRITE | REQ_SYNC;
-	/* bio_add_page won't fail on a freshly allocated bio */
-	bio_add_page(bio, page, PAGE_SIZE, 0);
-
-	if (btrfsic_submit_bio_wait(bio)) {
-		bio_put(bio);
-		btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_WRITE_ERRS);
-		return -EIO;
-	}
-
-	bio_put(bio);
-	return 0;
-}