diff mbox

[RFC,v2,1/5] btrfs: Fix the bug that fs_info->pending_changes is never cleared.

Message ID 1421744737-16586-2-git-send-email-quwenruo@cn.fujitsu.com (mailing list archive)
State Superseded
Headers show

Commit Message

Qu Wenruo Jan. 20, 2015, 9:05 a.m. UTC
Fs_info->pending_changes is never cleared since the original code uses
cmpxchg(&fs_info->pending_changes, 0, 0), which will only clear it if
pending_changes is already 0.

This will cause a lot of problem when mount it with inode_cache mount
option.
If the btrfs is mounted as inode_cache, pending_changes will always be
1, even when the fs is frozen.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
---
 fs/btrfs/transaction.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

David Sterba Jan. 20, 2015, 4:01 p.m. UTC | #1
On Tue, Jan 20, 2015 at 05:05:33PM +0800, Qu Wenruo wrote:
> Fs_info->pending_changes is never cleared since the original code uses
> cmpxchg(&fs_info->pending_changes, 0, 0), which will only clear it if
> pending_changes is already 0.
> 
> This will cause a lot of problem when mount it with inode_cache mount
> option.
> If the btrfs is mounted as inode_cache, pending_changes will always be
> 1, even when the fs is frozen.
> 
> Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>

Reviewed-by: David Sterba <dsterba@suse.cz>

Chris, please add this to 3.19-rc, introduced in this dev cycle.
--
To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
diff mbox

Patch

diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index a605d4e..e88b59d 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -2118,7 +2118,7 @@  void btrfs_apply_pending_changes(struct btrfs_fs_info *fs_info)
 	unsigned long prev;
 	unsigned long bit;
 
-	prev = cmpxchg(&fs_info->pending_changes, 0, 0);
+	prev = xchg(&fs_info->pending_changes, 0);
 	if (!prev)
 		return;