On Tue, Dec 13, 2016 at 02:33:33PM -0500, Jeff Mahoney wrote: > 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 can end up triggering > the WARN_ON in btrfs_select_ref_head since the head remains in the tree > with ->processing = 0 and the ready count is off. > > 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> > --- > fs/btrfs/extent-tree.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c > index 4607af3..73a8d31 100644 > --- a/fs/btrfs/extent-tree.c > +++ b/fs/btrfs/extent-tree.c > @@ -2588,6 +2588,7 @@ static noinline int __btrfs_run_delayed_refs(struct btrfs_trans_handle *trans, > if (must_insert_reserved) > locked_ref->must_insert_reserved = 1; > locked_ref->processing = 0; > + delayed_refs->num_heads_ready++; I think this requires spin lock/unlock around the increment, as do other similar places that fixup num_heads_ready after previous error. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
