Author: pjd
Date: Mon Sep 14 21:10:40 2009
New Revision: 197201
URL: http://svn.freebsd.org/changeset/base/197201
Log:
- Mount ZFS snapshots with MNT_IGNORE flag, so they are not visible in regular
df(1) and mount(8) output. This is a bit smilar to OpenSolaris and follows
ZFS route of not listing snapshots by default with 'zfs list' command.
- Add UPDATING entry to note that ZFS snapshots are no longer visible in
mount(8) and df(1) output by default.
Reviewed by: kib
MFC after: 3 days
Modified:
head/UPDATING
head/sys/cddl/compat/opensolaris/kern/opensolaris_vfs.c
head/sys/cddl/compat/opensolaris/sys/vfs.h
head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_ctldir.c
Modified: head/UPDATING
==============================================================================
--- head/UPDATING Mon Sep 14 21:08:22 2009 (r197200)
+++ head/UPDATING Mon Sep 14 21:10:40 2009 (r197201)
@@ -22,6 +22,10 @@ NOTE TO PEOPLE WHO THINK THAT FreeBSD 9.
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The old tunable hw.bus.devctl_disable has been superseded by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
Modified: head/sys/cddl/compat/opensolaris/kern/opensolaris_vfs.c
==============================================================================
--- head/sys/cddl/compat/opensolaris/kern/opensolaris_vfs.c Mon Sep 14
21:08:22 2009 (r197200)
+++ head/sys/cddl/compat/opensolaris/kern/opensolaris_vfs.c Mon Sep 14
21:10:40 2009 (r197201)
@@ -112,12 +112,13 @@ vfs_optionisset(const vfs_t *vfsp, const
}
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;
/*
@@ -132,23 +133,28 @@ domount(kthread_t *td, vnode_t *vp, cons
if (vfsp == NULL)
return (ENODEV);
+ vp = *vpp;
if (vp->v_type != VDIR)
return (ENOTDIR);
+ /*
+ * We need vnode lock to protect v_mountedhere and vnode interlock
+ * to protect v_iflag.
+ */
+ vn_lock(vp, LK_SHARED | LK_RETRY);
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);
+ VOP_UNLOCK(vp, 0);
return (EBUSY);
}
vp->v_iflag |= VI_MOUNT;
VI_UNLOCK(vp);
+ VOP_UNLOCK(vp, 0);
/*
* 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 +164,18 @@ domount(kthread_t *td, vnode_t *vp, cons
/*
* 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 +183,6 @@ domount(kthread_t *td, vnode_t *vp, cons
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 +191,7 @@ domount(kthread_t *td, vnode_t *vp, cons
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 +203,33 @@ domount(kthread_t *td, vnode_t *vp, cons
*/
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);
}
Modified: head/sys/cddl/compat/opensolaris/sys/vfs.h
==============================================================================
--- head/sys/cddl/compat/opensolaris/sys/vfs.h Mon Sep 14 21:08:22 2009
(r197200)
+++ head/sys/cddl/compat/opensolaris/sys/vfs.h Mon Sep 14 21:10:40 2009
(r197201)
@@ -110,8 +110,8 @@ void vfs_setmntopt(vfs_t *vfsp, const ch
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;
Modified: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_ctldir.c
==============================================================================
--- head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_ctldir.c Mon Sep
14 21:08:22 2009 (r197200)
+++ head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_ctldir.c Mon Sep
14 21:10:40 2009 (r197201)
@@ -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);
}
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