[PATCH RESEND v2 01/18] xfs: Fix multi-transaction larp replay

Allison Henderson
2022-08-04T19:40:33Z

Recent parent pointer testing has exposed a bug in the underlying
attr replay. A multi transaction replay currently performs a
single step of the replay, then deferrs the rest if there is more
to do. This causes race conditions with other attr replays that
might be recovered before the remaining deferred work has had a
chance to finish. This can lead to interleaved set and remove
operations that may clobber the attribute fork. Fix this by
deferring all work for any attribute operation.

Signed-off-by: Allison Henderson <allison.henderson@oracle.com>
---
fs/xfs/xfs_attr_item.c | 35 ++++++++---------------------------
1 file changed, 8 insertions(+), 27 deletions(-)

diff --git a/fs/xfs/xfs_attr_item.c b/fs/xfs/xfs_attr_item.c
index 5077a7ad5646..c13d724a3e13 100644
--- a/fs/xfs/xfs_attr_item.c
+++ b/fs/xfs/xfs_attr_item.c
@@ -635,52 +635,33 @@ xfs_attri_item_recover(
break;
case XFS_ATTRI_OP_FLAGS_REMOVE:
if (!xfs_inode_hasattr(args->dp))
- goto out;
+ return 0;
attr->xattri_dela_state = xfs_attr_init_remove_state(args);
break;
default:
ASSERT(0);
- error = -EFSCORRUPTED;
- goto out;
+ return -EFSCORRUPTED;
}

xfs_init_attr_trans(args, &tres, &total);
error = xfs_trans_alloc(mp, &tres, total, 0, XFS_TRANS_RESERVE, &tp);
if (error)
- goto out;
+ return error;

args->trans = tp;
done_item = xfs_trans_get_attrd(tp, attrip);
+ args->trans->t_flags |= XFS_TRANS_HAS_INTENT_DONE;
+ set_bit(XFS_LI_DIRTY, &done_item->attrd_item.li_flags);

xfs_ilock(ip, XFS_ILOCK_EXCL);
xfs_trans_ijoin(tp, ip, 0);

- error = xfs_xattri_finish_update(attr, done_item);
- if (error == -EAGAIN) {
- /*
- * There's more work to do, so add the intent item to this
- * transaction so that we can continue it later.
- */
- xfs_defer_add(tp, XFS_DEFER_OPS_TYPE_ATTR, &attr->xattri_list);
- error = xfs_defer_ops_capture_and_commit(tp, capture_list);
- if (error)
- goto out_unlock;
-
- xfs_iunlock(ip, XFS_ILOCK_EXCL);
- xfs_irele(ip);
- return 0;
- }
- if (error) {
- xfs_trans_cancel(tp);
- goto out_unlock;
- }
-
+ xfs_defer_add(tp, XFS_DEFER_OPS_TYPE_ATTR, &attr->xattri_list);
error = xfs_defer_ops_capture_and_commit(tp, capture_list);
-out_unlock:
+
xfs_iunlock(ip, XFS_ILOCK_EXCL);
xfs_irele(ip);
-out:
- xfs_attr_free_item(attr);
+
return error;
}

--
2.25.1