git: 26285c35d1f2 - stable/14 - nullfs: add a helper for testing if vnode belongs to a nullfs mount

The branch stable/14 has been updated by kib:

URL: https://cgit.FreeBSD.org/src/commit/?id=26285c35d1f25f9fbbcac93720eadc0cb45eda78

commit 26285c35d1f25f9fbbcac93720eadc0cb45eda78
Author:     Konstantin Belousov <kib@FreeBSD.org>
AuthorDate: 2025-10-08 15:42:27 +0000
Commit:     Konstantin Belousov <kib@FreeBSD.org>
CommitDate: 2025-10-24 09:47:36 +0000

    nullfs: add a helper for testing if vnode belongs to a nullfs mount
    
    (cherry picked from commit 419f2fe6b70b1a409bf7eca7020d7c745558690f)
---
 sys/fs/nullfs/null.h        | 10 ++++++++++
 sys/fs/nullfs/null_vfsops.c |  4 ++--
 sys/fs/nullfs/null_vnops.c  |  2 +-
 3 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/sys/fs/nullfs/null.h b/sys/fs/nullfs/null.h
index 3ae0cd02b2b6..34b8b4225ba8 100644
--- a/sys/fs/nullfs/null.h
+++ b/sys/fs/nullfs/null.h
@@ -80,6 +80,16 @@ struct vnode *null_checkvp(struct vnode *vp, char *fil, int lno);
 #endif
 
 extern struct vop_vector null_vnodeops;
+extern struct vop_vector null_vnodeops_no_unp_bypass;
+
+static inline bool
+null_is_nullfs_vnode(struct vnode *vp)
+{
+	const struct vop_vector *op;
+
+	op = vp->v_op;
+	return (op == &null_vnodeops);
+}
 
 #ifdef MALLOC_DECLARE
 MALLOC_DECLARE(M_NULLFSNODE);
diff --git a/sys/fs/nullfs/null_vfsops.c b/sys/fs/nullfs/null_vfsops.c
index 8d980932623d..14a6ed5d4d4c 100644
--- a/sys/fs/nullfs/null_vfsops.c
+++ b/sys/fs/nullfs/null_vfsops.c
@@ -120,7 +120,7 @@ nullfs_mount(struct mount *mp)
 	/*
 	 * Unlock lower node to avoid possible deadlock.
 	 */
-	if (mp->mnt_vnodecovered->v_op == &null_vnodeops &&
+	if (null_is_nullfs_vnode(mp->mnt_vnodecovered) &&
 	    VOP_ISLOCKED(mp->mnt_vnodecovered) == LK_EXCLUSIVE) {
 		VOP_UNLOCK(mp->mnt_vnodecovered);
 		isvnunlocked = true;
@@ -154,7 +154,7 @@ nullfs_mount(struct mount *mp)
 	/*
 	 * Check multi null mount to avoid `lock against myself' panic.
 	 */
-	if (mp->mnt_vnodecovered->v_op == &null_vnodeops) {
+	if (null_is_nullfs_vnode(mp->mnt_vnodecovered)) {
 		nn = VTONULL(mp->mnt_vnodecovered);
 		if (nn == NULL || lowerrootvp == nn->null_lowervp) {
 			NULLFSDEBUG("nullfs_mount: multi null mount?\n");
diff --git a/sys/fs/nullfs/null_vnops.c b/sys/fs/nullfs/null_vnops.c
index 41915da7f13c..e398053c7028 100644
--- a/sys/fs/nullfs/null_vnops.c
+++ b/sys/fs/nullfs/null_vnops.c
@@ -258,7 +258,7 @@ null_bypass(struct vop_generic_args *ap)
 		 * that aren't.  (We must always map first vp or vclean fails.)
 		 */
 		if (i != 0 && (*this_vp_p == NULLVP ||
-		    (*this_vp_p)->v_op != &null_vnodeops)) {
+		    !null_is_nullfs_vnode(*this_vp_p))) {
 			old_vps[i] = NULLVP;
 		} else {
 			old_vps[i] = *this_vp_p;