3 files changed, 56 insertions, 22 deletions

diff --git a/sys/fs/nullfs/null_subr.c b/sys/fs/nullfs/null_subr.c
index 0356877eaf05..7dcc83880bb9 100644
--- a/sys/fs/nullfs/null_subr.c
+++ b/sys/fs/nullfs/null_subr.c
@@ -245,6 +245,10 @@ null_nodeget(struct mount *mp, struct vnode *lowervp, struct vnode **vpp)
 		vp->v_object = lowervp->v_object;
 		vn_irflag_set(vp, VIRF_PGREAD);
 	}
+	if ((vn_irflag_read(lowervp) & VIRF_INOTIFY) != 0)
+		vn_irflag_set(vp, VIRF_INOTIFY);
+	if ((vn_irflag_read(lowervp) & VIRF_INOTIFY_PARENT) != 0)
+		vn_irflag_set(vp, VIRF_INOTIFY_PARENT);
 	if (lowervp == MOUNTTONULLMOUNT(mp)->nullm_lowerrootvp)
 		vp->v_vflag |= VV_ROOT;
 
diff --git a/sys/fs/nullfs/null_vfsops.c b/sys/fs/nullfs/null_vfsops.c
index 7ab1fb6c1a25..4cddf24a5745 100644
--- a/sys/fs/nullfs/null_vfsops.c
+++ b/sys/fs/nullfs/null_vfsops.c
@@ -365,12 +365,7 @@ nullfs_statfs(struct mount *mp, struct statfs *sbp)
 		return (error);
 	}
 
-	/* now copy across the "interesting" information and fake the rest */
 	sbp->f_type = mstat->f_type;
-	sbp->f_flags &= MNT_RDONLY | MNT_NOEXEC | MNT_NOSUID | MNT_UNION |
-	    MNT_NOSYMFOLLOW | MNT_AUTOMOUNTED | MNT_EXPORTED | MNT_IGNORE;
-	mstat->f_flags &= ~(MNT_ROOTFS | MNT_AUTOMOUNTED | MNT_EXPORTED);
-	sbp->f_flags |= mstat->f_flags;
 	sbp->f_bsize = mstat->f_bsize;
 	sbp->f_iosize = mstat->f_iosize;
 	sbp->f_blocks = mstat->f_blocks;
diff --git a/sys/fs/nullfs/null_vnops.c b/sys/fs/nullfs/null_vnops.c
index 4747b1dd5b82..74c1a8f3acb6 100644
--- a/sys/fs/nullfs/null_vnops.c
+++ b/sys/fs/nullfs/null_vnops.c
@@ -190,6 +190,26 @@ SYSCTL_INT(_debug, OID_AUTO, nullfs_bug_bypass, CTLFLAG_RW,
 	&null_bug_bypass, 0, "");
 
 /*
+ * Synchronize inotify flags with the lower vnode:
+ * - If the upper vnode has the flag set and the lower does not, then the lower
+ *   vnode is unwatched and the upper vnode does not need to go through
+ *   VOP_INOTIFY.
+ * - If the lower vnode is watched, then the upper vnode should go through
+ *   VOP_INOTIFY, so copy the flag up.
+ */
+static void
+null_copy_inotify(struct vnode *vp, struct vnode *lvp, short flag)
+{
+	if ((vn_irflag_read(vp) & flag) != 0) {
+		if (__predict_false((vn_irflag_read(lvp) & flag) == 0))
+			vn_irflag_unset(vp, flag);
+	} else if ((vn_irflag_read(lvp) & flag) != 0) {
+		if (__predict_false((vn_irflag_read(vp) & flag) == 0))
+			vn_irflag_set(vp, flag);
+	}
+}
+
+/*
  * This is the 10-Apr-92 bypass routine.
  *    This version has been optimized for speed, throwing away some
  * safety checks.  It should still always work, but it's not as
@@ -305,7 +325,10 @@ null_bypass(struct vop_generic_args *ap)
 			lvp = *(vps_p[i]);
 
 			/*
-			 * Get rid of the transient hold on lvp.
+			 * Get rid of the transient hold on lvp.  Copy inotify
+			 * flags up in case something is watching the lower
+			 * layer.
+			 *
 			 * If lowervp was unlocked during VOP
 			 * operation, nullfs upper vnode could have
 			 * been reclaimed, which changes its v_vnlock
@@ -314,6 +337,10 @@ null_bypass(struct vop_generic_args *ap)
 			 * upper (reclaimed) vnode.
 			 */
 			if (lvp != NULLVP) {
+				null_copy_inotify(old_vps[i], lvp,
+				    VIRF_INOTIFY);
+				null_copy_inotify(old_vps[i], lvp,
+				    VIRF_INOTIFY_PARENT);
 				if (VOP_ISLOCKED(lvp) == LK_EXCLUSIVE &&
 				    old_vps[i]->v_vnlock != lvp->v_vnlock) {
 					VOP_UNLOCK(lvp);
@@ -385,7 +412,7 @@ null_lookup(struct vop_lookup_args *ap)
 {
 	struct componentname *cnp = ap->a_cnp;
 	struct vnode *dvp = ap->a_dvp;
-	int flags = cnp->cn_flags;
+	uint64_t flags = cnp->cn_flags;
 	struct vnode *vp, *ldvp, *lvp;
 	struct mount *mp;
 	int error;
@@ -403,17 +430,25 @@ null_lookup(struct vop_lookup_args *ap)
 
 	/*
 	 * Renames in the lower mounts might create an inconsistent
-	 * configuration where lower vnode is moved out of the
-	 * directory tree remounted by our null mount.  Do not try to
-	 * handle it fancy, just avoid VOP_LOOKUP() with DOTDOT name
-	 * which cannot be handled by VOP, at least passing over lower
-	 * root.
+	 * configuration where lower vnode is moved out of the directory tree
+	 * remounted by our null mount.
+	 *
+	 * Do not try to handle it fancy, just avoid VOP_LOOKUP() with DOTDOT
+	 * name which cannot be handled by the VOP.
 	 */
-	if ((ldvp->v_vflag & VV_ROOT) != 0 && (flags & ISDOTDOT) != 0) {
-		KASSERT((dvp->v_vflag & VV_ROOT) == 0,
-		    ("ldvp %p fl %#x dvp %p fl %#x flags %#x",
-		    ldvp, ldvp->v_vflag, dvp, dvp->v_vflag, flags));
-		return (ENOENT);
+	if ((flags & ISDOTDOT) != 0) {
+		struct nameidata *ndp;
+
+		if ((ldvp->v_vflag & VV_ROOT) != 0) {
+			KASSERT((dvp->v_vflag & VV_ROOT) == 0,
+			    ("ldvp %p fl %#x dvp %p fl %#x flags %#jx",
+			    ldvp, ldvp->v_vflag, dvp, dvp->v_vflag,
+			    (uintmax_t)flags));
+			return (ENOENT);
+		}
+		ndp = vfs_lookup_nameidata(cnp);
+		if (ndp != NULL && vfs_lookup_isroot(ndp, ldvp))
+			return (ENOENT);
 	}
 
 	/*
@@ -528,7 +563,7 @@ null_setattr(struct vop_setattr_args *ap)
 		}
 	}
 
-	return (null_bypass((struct vop_generic_args *)ap));
+	return (null_bypass(&ap->a_gen));
 }
 
 /*
@@ -539,7 +574,7 @@ null_stat(struct vop_stat_args *ap)
 {
 	int error;
 
-	if ((error = null_bypass((struct vop_generic_args *)ap)) != 0)
+	if ((error = null_bypass(&ap->a_gen)) != 0)
 		return (error);
 
 	ap->a_sb->st_dev = ap->a_vp->v_mount->mnt_stat.f_fsid.val[0];
@@ -551,7 +586,7 @@ null_getattr(struct vop_getattr_args *ap)
 {
 	int error;
 
-	if ((error = null_bypass((struct vop_generic_args *)ap)) != 0)
+	if ((error = null_bypass(&ap->a_gen)) != 0)
 		return (error);
 
 	ap->a_vap->va_fsid = ap->a_vp->v_mount->mnt_stat.f_fsid.val[0];
@@ -584,7 +619,7 @@ null_access(struct vop_access_args *ap)
 			break;
 		}
 	}
-	return (null_bypass((struct vop_generic_args *)ap));
+	return (null_bypass(&ap->a_gen));
 }
 
 static int
@@ -610,7 +645,7 @@ null_accessx(struct vop_accessx_args *ap)
 			break;
 		}
 	}
-	return (null_bypass((struct vop_generic_args *)ap));
+	return (null_bypass(&ap->a_gen));
 }
 
 /*