1 files changed, 24 insertions, 6 deletions

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 881eb4667051..44fe66b53c8b 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -163,13 +163,13 @@ int __init extent_io_init(void)
 {
 	extent_state_cache = kmem_cache_create("btrfs_extent_state",
 			sizeof(struct extent_state), 0,
-			SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
+			SLAB_MEM_SPREAD, NULL);
 	if (!extent_state_cache)
 		return -ENOMEM;
 
 	extent_buffer_cache = kmem_cache_create("btrfs_extent_buffer",
 			sizeof(struct extent_buffer), 0,
-			SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
+			SLAB_MEM_SPREAD, NULL);
 	if (!extent_buffer_cache)
 		goto free_state_cache;
 
@@ -2750,7 +2750,6 @@ static int merge_bio(struct extent_io_tree *tree, struct page *page,
 	if (tree->ops && tree->ops->merge_bio_hook)
 		ret = tree->ops->merge_bio_hook(page, offset, size, bio,
 						bio_flags);
-	BUG_ON(ret < 0);
 	return ret;
 
 }
@@ -2873,6 +2872,7 @@ __get_extent_map(struct inode *inode, struct page *page, size_t pg_offset,
  * into the tree that are removed when the IO is done (by the end_io
  * handlers)
  * XXX JDM: This needs looking at to ensure proper page locking
+ * return 0 on success, otherwise return error
  */
 static int __do_readpage(struct extent_io_tree *tree,
 			 struct page *page,
@@ -2894,7 +2894,7 @@ static int __do_readpage(struct extent_io_tree *tree,
 	sector_t sector;
 	struct extent_map *em;
 	struct block_device *bdev;
-	int ret;
+	int ret = 0;
 	int nr = 0;
 	size_t pg_offset = 0;
 	size_t iosize;
@@ -3075,6 +3075,7 @@ static int __do_readpage(struct extent_io_tree *tree,
 		} else {
 			SetPageError(page);
 			unlock_extent(tree, cur, cur + iosize - 1);
+			goto out;
 		}
 		cur = cur + iosize;
 		pg_offset += iosize;
@@ -3085,7 +3086,7 @@ out:
 			SetPageUptodate(page);
 		unlock_page(page);
 	}
-	return 0;
+	return ret;
 }
 
 static inline void __do_contiguous_readpages(struct extent_io_tree *tree,
@@ -5224,14 +5225,31 @@ int read_extent_buffer_pages(struct extent_io_tree *tree,
 	atomic_set(&eb->io_pages, num_reads);
 	for (i = start_i; i < num_pages; i++) {
 		page = eb->pages[i];
+
 		if (!PageUptodate(page)) {
+			if (ret) {
+				atomic_dec(&eb->io_pages);
+				unlock_page(page);
+				continue;
+			}
+
 			ClearPageError(page);
 			err = __extent_read_full_page(tree, page,
 						      get_extent, &bio,
 						      mirror_num, &bio_flags,
 						      REQ_META);
-			if (err)
+			if (err) {
 				ret = err;
+				/*
+				 * We use &bio in above __extent_read_full_page,
+				 * so we ensure that if it returns error, the
+				 * current page fails to add itself to bio and
+				 * it's been unlocked.
+				 *
+				 * We must dec io_pages by ourselves.
+				 */
+				atomic_dec(&eb->io_pages);
+			}
 		} else {
 			unlock_page(page);
 		}