zfs_vptocnp: check for an invalid znode

... which can arise after the receive or rollback
and failed zfs_rezget().

Approved by:	re (kib)
MFC after:	1 week

1 files changed, 10 insertions, 2 deletions

diff --git a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vnops.c b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vnops.c
index a987138..c632618 100644
--- a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vnops.c
+++ b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vnops.c
@@ -7170,16 +7170,24 @@ zfs_vptocnp(struct vop_vptocnp_args *ap)
 	int ltype;
 	int error;
 
+	ZFS_ENTER(zfsvfs);
+	ZFS_VERIFY_ZP(zp);
+
 	/*
 	 * If we are a snapshot mounted under .zfs, run the operation
 	 * on the covered vnode.
 	 */
 	if ((error = sa_lookup(zp->z_sa_hdl,
-	    SA_ZPL_PARENT(zfsvfs), &parent, sizeof (parent))) != 0)
+	    SA_ZPL_PARENT(zfsvfs), &parent, sizeof (parent))) != 0) {
+		ZFS_EXIT(zfsvfs);
 		return (error);
+	}
 
-	if (zp->z_id != parent || zfsvfs->z_parent == zfsvfs)
+	if (zp->z_id != parent || zfsvfs->z_parent == zfsvfs) {
+		ZFS_EXIT(zfsvfs);
 		return (vop_stdvptocnp(ap));
+	}
+	ZFS_EXIT(zfsvfs);
 
 	covered_vp = vp->v_mount->mnt_vnodecovered;
 	vhold(covered_vp);