This is a note to let you know that I've just added the patch titled btrfs: fix error handling when run_delayed_extent_op fails to the 4.4-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-fix-error-handling-when-run_delayed_extent_op-fails.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From aa7c8da35d1905d80e840d075f07d26ec90144b5 Mon Sep 17 00:00:00 2001 From: Jeff Mahoney <jeffm@xxxxxxxx> Date: Tue, 20 Dec 2016 13:28:27 -0500 Subject: btrfs: fix error handling when run_delayed_extent_op fails From: Jeff Mahoney <jeffm@xxxxxxxx> commit aa7c8da35d1905d80e840d075f07d26ec90144b5 upstream. In __btrfs_run_delayed_refs, the error path when run_delayed_extent_op fails sets locked_ref->processing = 0 but doesn't re-increment delayed_refs->num_heads_ready. As a result, we end up triggering the WARN_ON in btrfs_select_ref_head. Fixes: d7df2c796d7 (Btrfs: attach delayed ref updates to delayed ref heads) Reported-by: Jon Nelson <jnelson-suse@xxxxxxxxxxx> Signed-off-by: Jeff Mahoney <jeffm@xxxxxxxx> Reviewed-by: Liu Bo <bo.li.liu@xxxxxxxxxx> Signed-off-by: David Sterba <dsterba@xxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/btrfs/extent-tree.c | 3 +++ 1 file changed, 3 insertions(+) --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -2570,7 +2570,10 @@ static noinline int __btrfs_run_delayed_ */ if (must_insert_reserved) locked_ref->must_insert_reserved = 1; + spin_lock(&delayed_refs->lock); locked_ref->processing = 0; + delayed_refs->num_heads_ready++; + spin_unlock(&delayed_refs->lock); btrfs_debug(fs_info, "run_delayed_extent_op returned %d", ret); btrfs_delayed_ref_unlock(locked_ref); return ret; Patches currently in stable-queue which might be from jeffm@xxxxxxxx are queue-4.4/btrfs-fix-error-handling-when-run_delayed_extent_op-fails.patch queue-4.4/btrfs-fix-locking-when-we-put-back-a-delayed-ref-that-s-too-new.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html