diff mbox

Btrfs: remove ourselves from the cluster list under lock

Message ID 1377205499-14790-1-git-send-email-jbacik@fusionio.com (mailing list archive)
State Accepted, archived
Headers show

Commit Message

Josef Bacik Aug. 22, 2013, 9:04 p.m. UTC
A user was reporting weird warnings from btrfs_put_delayed_ref() and I noticed
that we were doing this list_del_init() on our head ref outside of
delayed_refs->lock.  This is a problem if we have people still on the list, we
could end up modifying old pointers and such.  Fix this by removing us from the
list before we do our run_delayed_ref on our head ref.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
---
 fs/btrfs/extent-tree.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

Comments

Miao Xie Aug. 23, 2013, 7:43 a.m. UTC | #1
On 	thu, 22 Aug 2013 17:04:59 -0400, Josef Bacik wrote:
> A user was reporting weird warnings from btrfs_put_delayed_ref() and I noticed
> that we were doing this list_del_init() on our head ref outside of
> delayed_refs->lock.  This is a problem if we have people still on the list, we
> could end up modifying old pointers and such.  Fix this by removing us from the
> list before we do our run_delayed_ref on our head ref.  Thanks,

Looks good.

Reviewed-by: Miao Xie <miaox@cn.fujitsu.com>

> 
> Signed-off-by: Josef Bacik <jbacik@fusionio.com>
> ---
>  fs/btrfs/extent-tree.c |    3 ++-
>  1 files changed, 2 insertions(+), 1 deletions(-)
> 
> diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
> index 4c89566..95c6539 100644
> --- a/fs/btrfs/extent-tree.c
> +++ b/fs/btrfs/extent-tree.c
> @@ -2440,6 +2440,8 @@ static noinline int run_clustered_refs(struct btrfs_trans_handle *trans,
>  			default:
>  				WARN_ON(1);
>  			}
> +		} else {
> +			list_del_init(&locked_ref->cluster);
>  		}
>  		spin_unlock(&delayed_refs->lock);
>  
> @@ -2462,7 +2464,6 @@ static noinline int run_clustered_refs(struct btrfs_trans_handle *trans,
>  		 * list before we release it.
>  		 */
>  		if (btrfs_delayed_ref_is_head(ref)) {
> -			list_del_init(&locked_ref->cluster);
>  			btrfs_delayed_ref_unlock(locked_ref);
>  			locked_ref = NULL;
>  		}
> 

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diff mbox

Patch

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 4c89566..95c6539 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -2440,6 +2440,8 @@  static noinline int run_clustered_refs(struct btrfs_trans_handle *trans,
 			default:
 				WARN_ON(1);
 			}
+		} else {
+			list_del_init(&locked_ref->cluster);
 		}
 		spin_unlock(&delayed_refs->lock);
 
@@ -2462,7 +2464,6 @@  static noinline int run_clustered_refs(struct btrfs_trans_handle *trans,
 		 * list before we release it.
 		 */
 		if (btrfs_delayed_ref_is_head(ref)) {
-			list_del_init(&locked_ref->cluster);
 			btrfs_delayed_ref_unlock(locked_ref);
 			locked_ref = NULL;
 		}