This is a note to let you know that I've just added the patch titled
btrfs: don't loop for nowait writes when checking for cross references
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
btrfs-don-t-loop-for-nowait-writes-when-checking-for.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 625928ec012e53a2a0b19a709cada43e0fdd36a8
Author: Filipe Manana <fdmanana@xxxxxxxx>
Date: Fri Nov 15 15:46:13 2024 +0000
btrfs: don't loop for nowait writes when checking for cross references
[ Upstream commit ed67f2a913a4f0fc505db29805c41dd07d3cb356 ]
When checking for delayed refs when verifying if there are cross
references for a data extent, we stop if the path has nowait set and we
can't try lock the delayed ref head's mutex, returning -EAGAIN with the
goal of making a write fallback to a blocking context. However we ignore
the -EAGAIN at btrfs_cross_ref_exist() when check_delayed_ref() returns
it, and keep looping instead of immediately returning the -EAGAIN to the
caller.
Fix this by not looping if we get -EAGAIN and we have a nowait path.
Fixes: 26ce91144631 ("btrfs: make can_nocow_extent nowait compatible")
CC: stable@xxxxxxxxxxxxxxx # 6.1+
Reviewed-by: Josef Bacik <josef@xxxxxxxxxxxxxx>
Signed-off-by: Filipe Manana <fdmanana@xxxxxxxx>
Signed-off-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 94fc86c9c65e4..487697e8bc707 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -2401,7 +2401,7 @@ int btrfs_cross_ref_exist(struct btrfs_root *root, u64 objectid, u64 offset,
goto out;
ret = check_delayed_ref(root, path, objectid, offset, bytenr);
- } while (ret == -EAGAIN);
+ } while (ret == -EAGAIN && !path->nowait);
out:
btrfs_release_path(path);
