Index: UPDATING
===================================================================
--- UPDATING	(wersja 197195)
+++ UPDATING	(kopia robocza)
@@ -22,6 +22,10 @@ NOTE TO PEOPLE WHO THINK THAT FreeBSD 9.x IS SLOW:
 	machines to maximize performance.  (To disable malloc debugging, run
 	ln -s aj /etc/malloc.conf.)
 
+20090910:
+	ZFS snapshots are now mounted with MNT_IGNORE flag. Use -v option for
+	mount(8) and -a option for df(1) to see them.
+
 20090825:
 	The old tunable hw.bus.devctl_disable has been superseded by
 	hw.bus.devctl_queue.  hw.bus.devctl_disable=1 in loader.conf should be
Index: sbin/mount/mount.c
===================================================================
--- sbin/mount/mount.c	(wersja 197195)
+++ sbin/mount/mount.c	(kopia robocza)
@@ -348,6 +348,9 @@ main(int argc, char *argv[])
 				if (checkvfsname(mntbuf[i].f_fstypename,
 				    vfslist))
 					continue;
+				if (!verbose &&
+				    (mntbuf[i].f_flags & MNT_IGNORE) != 0)
+					continue;
 				prmount(&mntbuf[i]);
 			}
 		}
Index: sbin/mount/mount.8
===================================================================
--- sbin/mount/mount.8	(wersja 197195)
+++ sbin/mount/mount.8	(kopia robocza)
@@ -469,6 +469,12 @@ or
 option.
 .It Fl v
 Verbose mode.
+If the
+.Fl v
+is used alone, show all file systems, including those that were mounted with the
+.Dv MNT_IGNORE
+flag and show additional information about each file system (including fsid
+when run by root).
 .It Fl w
 The file system object is to be read and write.
 .El
Index: sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_ctldir.c
===================================================================
--- sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_ctldir.c	(wersja 197195)
+++ sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_ctldir.c	(kopia robocza)
@@ -880,17 +880,9 @@ domount:
 	mountpoint = kmem_alloc(mountpoint_len, KM_SLEEP);
 	(void) snprintf(mountpoint, mountpoint_len, "%s/.zfs/snapshot/%s",
 	    dvp->v_vfsp->mnt_stat.f_mntonname, nm);
-	err = domount(curthread, *vpp, "zfs", mountpoint, snapname, 0);
+	err = mount_snapshot(curthread, vpp, "zfs", mountpoint, snapname, 0);
 	kmem_free(mountpoint, mountpoint_len);
 	if (err == 0) {
-		vnode_t *mvp;
-
-		ASSERT((*vpp)->v_mountedhere != NULL);
-		err = VFS_ROOT((*vpp)->v_mountedhere, LK_EXCLUSIVE, &mvp);
-		ASSERT(err == 0);
-		VN_RELE(*vpp);
-		*vpp = mvp;
-
 		/*
 		 * Fix up the root vnode mounted on .zfs/snapshot/<snapname>.
 		 *
@@ -902,14 +894,6 @@ domount:
 		VTOZ(*vpp)->z_zfsvfs->z_parent = zfsvfs;
 	}
 	mutex_exit(&sdp->sd_lock);
-	/*
-	 * If we had an error, drop our hold on the vnode and
-	 * zfsctl_snapshot_inactive() will clean up.
-	 */
-	if (err) {
-		VN_RELE(*vpp);
-		*vpp = NULL;
-	}
 	ZFS_EXIT(zfsvfs);
 	return (err);
 }
Index: sys/cddl/compat/opensolaris/kern/opensolaris_vfs.c
===================================================================
--- sys/cddl/compat/opensolaris/kern/opensolaris_vfs.c	(wersja 197196)
+++ sys/cddl/compat/opensolaris/kern/opensolaris_vfs.c	(kopia robocza)
@@ -112,12 +112,13 @@ vfs_optionisset(const vfs_t *vfsp, const char *opt
 }
 
 int
-domount(kthread_t *td, vnode_t *vp, const char *fstype, char *fspath,
+mount_snapshot(kthread_t *td, vnode_t **vpp, const char *fstype, char *fspath,
     char *fspec, int fsflags)
 {
 	struct mount *mp;
 	struct vfsconf *vfsp;
 	struct ucred *cr;
+	vnode_t *vp;
 	int error;
 
 	/*
@@ -132,11 +133,11 @@ int
 	if (vfsp == NULL)
 		return (ENODEV);
 
+	vp = *vpp;
 	if (vp->v_type != VDIR)
 		return (ENOTDIR);
 	VI_LOCK(vp);
-	if ((vp->v_iflag & VI_MOUNT) != 0 ||
-	    vp->v_mountedhere != NULL) {
+	if ((vp->v_iflag & VI_MOUNT) != 0 || vp->v_mountedhere != NULL) {
 		VI_UNLOCK(vp);
 		return (EBUSY);
 	}
@@ -146,9 +147,7 @@ int
 	/*
 	 * Allocate and initialize the filesystem.
 	 */
-	vn_lock(vp, LK_SHARED | LK_RETRY);
 	mp = vfs_mount_alloc(vp, vfsp, fspath, td->td_ucred);
-	VOP_UNLOCK(vp, 0);
 
 	mp->mnt_optnew = NULL;
 	vfs_setmntopt(mp, "from", fspec, 0);
@@ -158,11 +157,18 @@ int
 	/*
 	 * Set the mount level flags.
 	 */
-	if (fsflags & MNT_RDONLY)
-		mp->mnt_flag |= MNT_RDONLY;
-	mp->mnt_flag &=~ MNT_UPDATEMASK;
+	mp->mnt_flag &= ~MNT_UPDATEMASK;
 	mp->mnt_flag |= fsflags & (MNT_UPDATEMASK | MNT_FORCE | MNT_ROOTFS);
 	/*
+	 * Snapshots are always read-only.
+	 */
+	mp->mnt_flag |= MNT_RDONLY;
+	/*
+	 * We don't want snapshots to be visible in regular
+	 * mount(8) and df(1) output.
+	 */
+	mp->mnt_flag |= MNT_IGNORE;
+	/*
 	 * Unprivileged user can trigger mounting a snapshot, but we don't want
 	 * him to unmount it, so we switch to privileged of original mount.
 	 */
@@ -170,11 +176,6 @@ int
 	mp->mnt_cred = crdup(vp->v_mount->mnt_cred);
 	mp->mnt_stat.f_owner = mp->mnt_cred->cr_uid;
 	/*
-	 * Mount the filesystem.
-	 * XXX The final recipients of VFS_MOUNT just overwrite the ndp they
-	 * get.  No freeing of cn_pnbuf.
-	 */
-	/*
 	 * XXX: This is evil, but we can't mount a snapshot as a regular user.
 	 * XXX: Is is safe when snapshot is mounted from within a jail?
 	 */
@@ -183,7 +184,7 @@ int
 	error = VFS_MOUNT(mp);
 	td->td_ucred = cr;
 
-	if (!error) {
+	if (error == 0) {
 		if (mp->mnt_opt != NULL)
 			vfs_freeopts(mp->mnt_opt);
 		mp->mnt_opt = mp->mnt_optnew;
@@ -195,42 +196,33 @@ int
 	*/
 	mp->mnt_optnew = NULL;
 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
-	/*
-	 * Put the new filesystem on the mount list after root.
-	 */
 #ifdef FREEBSD_NAMECACHE
 	cache_purge(vp);
 #endif
-	if (!error) {
+	VI_LOCK(vp);
+	vp->v_iflag &= ~VI_MOUNT;
+	VI_UNLOCK(vp);
+	if (error == 0) {
 		vnode_t *mvp;
 
-		VI_LOCK(vp);
-		vp->v_iflag &= ~VI_MOUNT;
-		VI_UNLOCK(vp);
 		vp->v_mountedhere = mp;
+		/*
+		 * Put the new filesystem on the mount list.
+		 */
 		mtx_lock(&mountlist_mtx);
 		TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list);
 		mtx_unlock(&mountlist_mtx);
 		vfs_event_signal(NULL, VQ_MOUNT, 0);
 		if (VFS_ROOT(mp, LK_EXCLUSIVE, &mvp))
 			panic("mount: lost mount");
-		mountcheckdirs(vp, mvp);
-		vput(mvp);
-		VOP_UNLOCK(vp, 0);
-		if ((mp->mnt_flag & MNT_RDONLY) == 0)
-			error = vfs_allocate_syncvnode(mp);
+		vput(vp);
 		vfs_unbusy(mp);
-		if (error)
-			vrele(vp);
-		else
-			vfs_mountedfrom(mp, fspec);
+		*vpp = mvp;
 	} else {
-		VI_LOCK(vp);
-		vp->v_iflag &= ~VI_MOUNT;
-		VI_UNLOCK(vp);
-		VOP_UNLOCK(vp, 0);
+		vput(vp);
 		vfs_unbusy(mp);
 		vfs_mount_destroy(mp);
+		*vpp = NULL;
 	}
 	return (error);
 }
Index: sys/cddl/compat/opensolaris/sys/vfs.h
===================================================================
--- sys/cddl/compat/opensolaris/sys/vfs.h	(wersja 197195)
+++ sys/cddl/compat/opensolaris/sys/vfs.h	(kopia robocza)
@@ -110,8 +110,8 @@ void vfs_setmntopt(vfs_t *vfsp, const char *name,
     int flags __unused);
 void vfs_clearmntopt(vfs_t *vfsp, const char *name);
 int vfs_optionisset(const vfs_t *vfsp, const char *opt, char **argp);
-int domount(kthread_t *td, vnode_t *vp, const char *fstype, char *fspath,
-    char *fspec, int fsflags);
+int mount_snapshot(kthread_t *td, vnode_t **vpp, const char *fstype,
+    char *fspath, char *fspec, int fsflags);
 
 typedef	uint64_t	vfs_feature_t;