Thread (138 messages) 138 messages, 4 authors, 2021-03-03
STALE1916d REVIEWED: 4 (4M)

[PATCH 4.9 044/134] btrfs: clarify error returns values in __load_free_space_cache

From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2021-03-01 17:35:28
Also in: lkml
Subsystem: btrfs file system, filesystems (vfs and infrastructure), the rest · Maintainers: Chris Mason, David Sterba, Alexander Viro, Christian Brauner, Linus Torvalds

From: Zhihao Cheng <chengzhihao1@huawei.com>

[ Upstream commit 3cc64e7ebfb0d7faaba2438334c43466955a96e8 ]

Return value in __load_free_space_cache is not properly set after
(unlikely) memory allocation failures and 0 is returned instead.
This is not a problem for the caller load_free_space_cache because only
value 1 is considered as 'cache loaded' but for clarity it's better
to set the errors accordingly.

Fixes: a67509c30079 ("Btrfs: add a io_ctl struct and helpers for dealing with the space cache")
Reported-by: Hulk Robot <redacted>
Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/btrfs/free-space-cache.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index 8e93bd391b352..f74cb39a64e5e 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -753,8 +753,10 @@ static int __load_free_space_cache(struct btrfs_root *root, struct inode *inode,
 	while (num_entries) {
 		e = kmem_cache_zalloc(btrfs_free_space_cachep,
 				      GFP_NOFS);
-		if (!e)
+		if (!e) {
+			ret = -ENOMEM;
 			goto free_cache;
+		}
 
 		ret = io_ctl_read_entry(&io_ctl, e, &type);
 		if (ret) {
@@ -763,6 +765,7 @@ static int __load_free_space_cache(struct btrfs_root *root, struct inode *inode,
 		}
 
 		if (!e->bytes) {
+			ret = -1;
 			kmem_cache_free(btrfs_free_space_cachep, e);
 			goto free_cache;
 		}
@@ -782,6 +785,7 @@ static int __load_free_space_cache(struct btrfs_root *root, struct inode *inode,
 			num_bitmaps--;
 			e->bitmap = kzalloc(PAGE_SIZE, GFP_NOFS);
 			if (!e->bitmap) {
+				ret = -ENOMEM;
 				kmem_cache_free(
 					btrfs_free_space_cachep, e);
 				goto free_cache;
-- 
2.27.0


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