xfs: ignore leaf attr ichdr.count in verifier during log replay

When we create a new attribute, we first create a shortform
attribute, and try to fit the new attribute into it.
If that fails, we copy the (empty) attribute into a leaf attribute,
and do the copy again.  Thus there can be a transient state where
we have an empty leaf attribute.

If we encounter this during log replay, the verifier will fail.
So add a test to ignore this part of the leaf attr verification
during log replay.

Thanks as usual to dchinner for spotting the problem.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>

diff --git a/fs/xfs/libxfs/xfs_attr_leaf.c b/fs/xfs/libxfs/xfs_attr_leaf.c
index 8ea91f3630938a63523602e5d14c2553a472c015..2852521fc8ecf797be90372a23c3343e9a8039dc 100644 (file)
--- a/fs/xfs/libxfs/xfs_attr_leaf.c
+++ b/fs/xfs/libxfs/xfs_attr_leaf.c
@@ -253,6 +253,7 @@ xfs_attr3_leaf_verify(
 {
        struct xfs_mount        *mp = bp->b_target->bt_mount;
        struct xfs_attr_leafblock *leaf = bp->b_addr;
+       struct xfs_perag *pag = bp->b_pag;
        struct xfs_attr3_icleaf_hdr ichdr;
 
        xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo, &ichdr, leaf);
@@ -273,7 +274,12 @@ xfs_attr3_leaf_verify(
                if (ichdr.magic != XFS_ATTR_LEAF_MAGIC)
                        return false;
        }
-       if (ichdr.count == 0)
+       /*
+        * In recovery there is a transient state where count == 0 is valid
+        * because we may have transitioned an empty shortform attr to a leaf
+        * if the attr didn't fit in shortform.
+        */
+       if (pag && pag->pagf_init && ichdr.count == 0)
                return false;
 
        /* XXX: need to range check rest of attr header values */