Two recent commits in sys/ufs/ufs interacted badly with ext2fs

because it shares ufs code. In ufs_fhtovp(), the test on i_effnlink
is invalid because ext2fs does not maintain this field. In ufs_close(),
i_effnlink is also tested, to determines whether or not to call
vn_start_write(). The ufs_fhtovp issue breaks NFS exporting of
ext2fs filesystems; I believe the other is harmless.

Fix both cases by checking um_i_effnlink_valid in the ufsmount
struct, and use i_nlink if necessary.

Noticed by:	bde
Reviewed by:	mckusick, bde

2 files changed, 5 insertions, 2 deletions

diff --git a/sys/ufs/ufs/ufs_vfsops.c b/sys/ufs/ufs/ufs_vfsops.c
index 6b8905b..1fcd530 100644
--- a/sys/ufs/ufs/ufs_vfsops.c
+++ b/sys/ufs/ufs/ufs_vfsops.c
@@ -207,7 +207,8 @@ ufs_fhtovp(mp, ufhp, vpp)
 	ip = VTOI(nvp);
 	if (ip->i_mode == 0 ||
 	    ip->i_gen != ufhp->ufid_gen ||
-	    ip->i_effnlink <= 0) {
+	    (VFSTOUFS(mp)->um_i_effnlink_valid ? ip->i_effnlink :
+	    ip->i_nlink) <= 0) {
 		vput(nvp);
 		*vpp = NULLVP;
 		return (ESTALE);
diff --git a/sys/ufs/ufs/ufs_vnops.c b/sys/ufs/ufs/ufs_vnops.c
index ea871b6..a095798 100644
--- a/sys/ufs/ufs/ufs_vnops.c
+++ b/sys/ufs/ufs/ufs_vnops.c
@@ -311,7 +311,9 @@ ufs_close(ap)
 		 * XXX - EAGAIN is returned to prevent vn_close from
 		 * repeating the vrele operation.
 		 */
-		if (vp->v_type == VREG && VTOI(vp)->i_effnlink == 0) {
+		if (vp->v_type == VREG &&
+		    (VFSTOUFS(vp->v_mount)->um_i_effnlink_valid ?
+		    VTOI(vp)->i_effnlink : VTOI(vp)->i_nlink) == 0) {
 			(void) vn_start_write(vp, &mp, V_WAIT);
 			vrele(vp);
 			vn_finished_write(mp);