4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
23 * Copyright (c) 2012, 2015 by Delphix. All rights reserved.
24 * Copyright 2015, OmniTI Computer Consulting, Inc. All rights reserved.
28 * ZFS control directory (a.k.a. ".zfs")
30 * This directory provides a common location for all ZFS meta-objects.
31 * Currently, this is only the 'snapshot' directory, but this may expand in the
32 * future. The elements are built using the GFS primitives, as the hierarchy
33 * does not actually exist on disk.
35 * For 'snapshot', we don't want to have all snapshots always mounted, because
36 * this would take up a huge amount of space in /etc/mnttab. We have three
39 * ctldir ------> snapshotdir -------> snapshot
45 * The 'snapshot' node contains just enough information to lookup '..' and act
46 * as a mountpoint for the snapshot. Whenever we lookup a specific snapshot, we
47 * perform an automount of the underlying filesystem and return the
48 * corresponding vnode.
50 * All mounts are handled automatically by the kernel, but unmounts are
51 * (currently) handled from user land. The main reason is that there is no
52 * reliable way to auto-unmount the filesystem when it's "no longer in use".
53 * When the user unmounts a filesystem, we call zfsctl_unmount(), which
54 * unmounts any snapshots within the snapshot directory.
56 * The '.zfs', '.zfs/snapshot', and all directories created under
57 * '.zfs/snapshot' (ie: '.zfs/snapshot/<snapname>') are all GFS nodes and
58 * share the same vfs_t as the head filesystem (what '.zfs' lives under).
60 * File systems mounted ontop of the GFS nodes '.zfs/snapshot/<snapname>'
61 * (ie: snapshots) are ZFS nodes and have their own unique vfs_t.
62 * However, vnodes within these mounted on file systems have their v_vfsp
63 * fields set to the head filesystem to make NFS happy (see
64 * zfsctl_snapdir_lookup()). We VFS_HOLD the head filesystem's vfs_t
65 * so that it cannot be freed until all snapshots have been unmounted.
68 #include <sys/zfs_context.h>
69 #include <sys/zfs_ctldir.h>
70 #include <sys/zfs_ioctl.h>
71 #include <sys/zfs_vfsops.h>
72 #include <sys/namei.h>
76 #include <sys/dsl_destroy.h>
77 #include <sys/dsl_deleg.h>
78 #include <sys/mount.h>
79 #include <sys/sunddi.h>
81 #include "zfs_namecheck.h"
83 typedef struct zfsctl_node {
84 gfs_dir_t zc_gfs_private;
86 timestruc_t zc_cmtime; /* ctime and mtime, always the same */
89 typedef struct zfsctl_snapdir {
90 zfsctl_node_t sd_node;
102 snapentry_compare(const void *a, const void *b)
104 const zfs_snapentry_t *sa = a;
105 const zfs_snapentry_t *sb = b;
106 int ret = strcmp(sa->se_name, sb->se_name);
117 vnodeops_t *zfsctl_ops_root;
118 vnodeops_t *zfsctl_ops_snapdir;
119 vnodeops_t *zfsctl_ops_snapshot;
120 vnodeops_t *zfsctl_ops_shares;
121 vnodeops_t *zfsctl_ops_shares_dir;
123 static const fs_operation_def_t zfsctl_tops_root[];
124 static const fs_operation_def_t zfsctl_tops_snapdir[];
125 static const fs_operation_def_t zfsctl_tops_snapshot[];
126 static const fs_operation_def_t zfsctl_tops_shares[];
128 static struct vop_vector zfsctl_ops_root;
129 static struct vop_vector zfsctl_ops_snapdir;
130 static struct vop_vector zfsctl_ops_snapshot;
131 static struct vop_vector zfsctl_ops_shares;
132 static struct vop_vector zfsctl_ops_shares_dir;
135 static vnode_t *zfsctl_mknode_snapdir(vnode_t *);
136 static vnode_t *zfsctl_mknode_shares(vnode_t *);
137 static vnode_t *zfsctl_snapshot_mknode(vnode_t *, uint64_t objset);
138 static int zfsctl_unmount_snap(zfs_snapentry_t *, int, cred_t *);
141 static gfs_opsvec_t zfsctl_opsvec[] = {
142 { ".zfs", zfsctl_tops_root, &zfsctl_ops_root },
143 { ".zfs/snapshot", zfsctl_tops_snapdir, &zfsctl_ops_snapdir },
144 { ".zfs/snapshot/vnode", zfsctl_tops_snapshot, &zfsctl_ops_snapshot },
145 { ".zfs/shares", zfsctl_tops_shares, &zfsctl_ops_shares_dir },
146 { ".zfs/shares/vnode", zfsctl_tops_shares, &zfsctl_ops_shares },
152 * Root directory elements. We only have two entries
153 * snapshot and shares.
155 static gfs_dirent_t zfsctl_root_entries[] = {
156 { "snapshot", zfsctl_mknode_snapdir, GFS_CACHE_VNODE },
157 { "shares", zfsctl_mknode_shares, GFS_CACHE_VNODE },
161 /* include . and .. in the calculation */
162 #define NROOT_ENTRIES ((sizeof (zfsctl_root_entries) / \
163 sizeof (gfs_dirent_t)) + 1)
167 * Initialize the various GFS pieces we'll need to create and manipulate .zfs
168 * directories. This is called from the ZFS init routine, and initializes the
169 * vnode ops vectors that we'll be using.
175 VERIFY(gfs_make_opsvec(zfsctl_opsvec) == 0);
184 * Remove vfsctl vnode ops
187 vn_freevnodeops(zfsctl_ops_root);
188 if (zfsctl_ops_snapdir)
189 vn_freevnodeops(zfsctl_ops_snapdir);
190 if (zfsctl_ops_snapshot)
191 vn_freevnodeops(zfsctl_ops_snapshot);
192 if (zfsctl_ops_shares)
193 vn_freevnodeops(zfsctl_ops_shares);
194 if (zfsctl_ops_shares_dir)
195 vn_freevnodeops(zfsctl_ops_shares_dir);
197 zfsctl_ops_root = NULL;
198 zfsctl_ops_snapdir = NULL;
199 zfsctl_ops_snapshot = NULL;
200 zfsctl_ops_shares = NULL;
201 zfsctl_ops_shares_dir = NULL;
206 zfsctl_is_node(vnode_t *vp)
208 return (vn_matchops(vp, zfsctl_ops_root) ||
209 vn_matchops(vp, zfsctl_ops_snapdir) ||
210 vn_matchops(vp, zfsctl_ops_snapshot) ||
211 vn_matchops(vp, zfsctl_ops_shares) ||
212 vn_matchops(vp, zfsctl_ops_shares_dir));
217 * Return the inode number associated with the 'snapshot' or
218 * 'shares' directory.
222 zfsctl_root_inode_cb(vnode_t *vp, int index)
224 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data;
229 return (ZFSCTL_INO_SNAPDIR);
231 return (zfsvfs->z_shares_dir);
235 * Create the '.zfs' directory. This directory is cached as part of the VFS
236 * structure. This results in a hold on the vfs_t. The code in zfs_umount()
237 * therefore checks against a vfs_count of 2 instead of 1. This reference
238 * is removed when the ctldir is destroyed in the unmount.
241 zfsctl_create(zfsvfs_t *zfsvfs)
247 ASSERT(zfsvfs->z_ctldir == NULL);
249 vp = gfs_root_create(sizeof (zfsctl_node_t), zfsvfs->z_vfs,
250 &zfsctl_ops_root, ZFSCTL_INO_ROOT, zfsctl_root_entries,
251 zfsctl_root_inode_cb, MAXNAMELEN, NULL, NULL);
253 zcp->zc_id = ZFSCTL_INO_ROOT;
255 VERIFY(VFS_ROOT(zfsvfs->z_vfs, LK_EXCLUSIVE, &rvp) == 0);
256 VERIFY(0 == sa_lookup(VTOZ(rvp)->z_sa_hdl, SA_ZPL_CRTIME(zfsvfs),
257 &crtime, sizeof (crtime)));
258 ZFS_TIME_DECODE(&zcp->zc_cmtime, crtime);
262 * We're only faking the fact that we have a root of a filesystem for
263 * the sake of the GFS interfaces. Undo the flag manipulation it did
266 vp->v_vflag &= ~VV_ROOT;
268 zfsvfs->z_ctldir = vp;
274 * Destroy the '.zfs' directory. Only called when the filesystem is unmounted.
275 * There might still be more references if we were force unmounted, but only
276 * new zfs_inactive() calls can occur and they don't reference .zfs
279 zfsctl_destroy(zfsvfs_t *zfsvfs)
281 VN_RELE(zfsvfs->z_ctldir);
282 zfsvfs->z_ctldir = NULL;
286 * Given a root znode, retrieve the associated .zfs directory.
287 * Add a hold to the vnode and return it.
290 zfsctl_root(znode_t *zp)
292 ASSERT(zfs_has_ctldir(zp));
293 VN_HOLD(zp->z_zfsvfs->z_ctldir);
294 return (zp->z_zfsvfs->z_ctldir);
298 zfsctl_common_print(ap)
299 struct vop_print_args /* {
303 vnode_t *vp = ap->a_vp;
304 gfs_file_t *fp = vp->v_data;
306 printf(" parent = %p\n", fp->gfs_parent);
307 printf(" type = %d\n", fp->gfs_type);
308 printf(" index = %d\n", fp->gfs_index);
309 printf(" ino = %ju\n", (uintmax_t)fp->gfs_ino);
314 * Common open routine. Disallow any write access.
318 zfsctl_common_open(struct vop_open_args *ap)
320 int flags = ap->a_mode;
323 return (SET_ERROR(EACCES));
329 * Common close routine. Nothing to do here.
333 zfsctl_common_close(struct vop_close_args *ap)
339 * Common access routine. Disallow writes.
343 zfsctl_common_access(ap)
344 struct vop_access_args /* {
347 struct ucred *a_cred;
351 accmode_t accmode = ap->a_accmode;
354 if (flags & V_ACE_MASK) {
355 if (accmode & ACE_ALL_WRITE_PERMS)
356 return (SET_ERROR(EACCES));
359 if (accmode & VWRITE)
360 return (SET_ERROR(EACCES));
369 * Common getattr function. Fill in basic information.
372 zfsctl_common_getattr(vnode_t *vp, vattr_t *vap)
380 * We are a purely virtual object, so we have no
381 * blocksize or allocated blocks.
386 vap->va_fsid = vp->v_mount->mnt_stat.f_fsid.val[0];
387 vap->va_mode = S_IRUSR | S_IXUSR | S_IRGRP | S_IXGRP |
391 * We live in the now (for atime).
395 /* FreeBSD: Reset chflags(2) flags. */
401 zfsctl_common_fid(ap)
402 struct vop_fid_args /* {
407 vnode_t *vp = ap->a_vp;
408 fid_t *fidp = (void *)ap->a_fid;
409 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data;
410 zfsctl_node_t *zcp = vp->v_data;
411 uint64_t object = zcp->zc_id;
418 if (fidp->fid_len < SHORT_FID_LEN) {
419 fidp->fid_len = SHORT_FID_LEN;
421 return (SET_ERROR(ENOSPC));
425 zfid = (zfid_short_t *)fidp;
427 zfid->zf_len = SHORT_FID_LEN;
429 for (i = 0; i < sizeof (zfid->zf_object); i++)
430 zfid->zf_object[i] = (uint8_t)(object >> (8 * i));
432 /* .zfs znodes always have a generation number of 0 */
433 for (i = 0; i < sizeof (zfid->zf_gen); i++)
443 zfsctl_shares_fid(ap)
444 struct vop_fid_args /* {
449 vnode_t *vp = ap->a_vp;
450 fid_t *fidp = (void *)ap->a_fid;
451 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data;
457 if (zfsvfs->z_shares_dir == 0) {
459 return (SET_ERROR(ENOTSUP));
462 if ((error = zfs_zget(zfsvfs, zfsvfs->z_shares_dir, &dzp)) == 0) {
463 error = VOP_FID(ZTOV(dzp), fidp);
472 * .zfs inode namespace
474 * We need to generate unique inode numbers for all files and directories
475 * within the .zfs pseudo-filesystem. We use the following scheme:
480 * .zfs/snapshot/<snap> objectid(snap)
483 #define ZFSCTL_INO_SNAP(id) (id)
486 * Get root directory attributes.
490 zfsctl_root_getattr(ap)
491 struct vop_getattr_args /* {
494 struct ucred *a_cred;
497 struct vnode *vp = ap->a_vp;
498 struct vattr *vap = ap->a_vap;
499 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data;
500 zfsctl_node_t *zcp = vp->v_data;
503 vap->va_nodeid = ZFSCTL_INO_ROOT;
504 vap->va_nlink = vap->va_size = NROOT_ENTRIES;
505 vap->va_mtime = vap->va_ctime = zcp->zc_cmtime;
506 vap->va_birthtime = vap->va_ctime;
508 zfsctl_common_getattr(vp, vap);
515 * Special case the handling of "..".
519 zfsctl_root_lookup(vnode_t *dvp, char *nm, vnode_t **vpp, pathname_t *pnp,
520 int flags, vnode_t *rdir, cred_t *cr, caller_context_t *ct,
521 int *direntflags, pathname_t *realpnp)
523 zfsvfs_t *zfsvfs = dvp->v_vfsp->vfs_data;
527 * No extended attributes allowed under .zfs
529 if (flags & LOOKUP_XATTR)
530 return (SET_ERROR(EINVAL));
534 if (strcmp(nm, "..") == 0) {
536 err = VFS_ROOT(dvp->v_vfsp, LK_EXCLUSIVE, vpp);
539 * NB: can not use VFS_ROOT here as it would acquire
540 * the vnode lock of the parent (root) vnode while
541 * holding the child's (.zfs) lock.
545 err = zfs_zget(zfsvfs, zfsvfs->z_root, &rootzp);
550 err = gfs_vop_lookup(dvp, nm, vpp, pnp, flags, rdir,
551 cr, ct, direntflags, realpnp);
560 zfsctl_freebsd_root_lookup(ap)
561 struct vop_lookup_args /* {
563 struct vnode **a_vpp;
564 struct componentname *a_cnp;
567 vnode_t *dvp = ap->a_dvp;
568 vnode_t **vpp = ap->a_vpp;
569 cred_t *cr = ap->a_cnp->cn_cred;
570 int flags = ap->a_cnp->cn_flags;
571 int lkflags = ap->a_cnp->cn_lkflags;
572 int nameiop = ap->a_cnp->cn_nameiop;
573 char nm[NAME_MAX + 1];
576 if ((flags & ISLASTCN) && (nameiop == RENAME || nameiop == CREATE))
579 ASSERT(ap->a_cnp->cn_namelen < sizeof(nm));
580 strlcpy(nm, ap->a_cnp->cn_nameptr, ap->a_cnp->cn_namelen + 1);
582 err = zfsctl_root_lookup(dvp, nm, vpp, NULL, 0, NULL, cr, NULL, NULL, NULL);
583 if (err == 0 && (nm[0] != '.' || nm[1] != '\0')) {
584 if (flags & ISDOTDOT) {
586 err = vn_lock(*vpp, lkflags);
591 vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY);
593 err = vn_lock(*vpp, LK_EXCLUSIVE);
595 VERIFY3S(err, ==, ENOENT);
604 zfsctl_root_print(ap)
605 struct vop_print_args /* {
609 printf(" .zfs node\n");
610 zfsctl_common_print(ap);
616 zfsctl_pathconf(vnode_t *vp, int cmd, ulong_t *valp, cred_t *cr,
617 caller_context_t *ct)
620 * We only care about ACL_ENABLED so that libsec can
621 * display ACL correctly and not default to POSIX draft.
623 if (cmd == _PC_ACL_ENABLED) {
624 *valp = _ACL_ACE_ENABLED;
628 return (fs_pathconf(vp, cmd, valp, cr, ct));
633 static const fs_operation_def_t zfsctl_tops_root[] = {
634 { VOPNAME_OPEN, { .vop_open = zfsctl_common_open } },
635 { VOPNAME_CLOSE, { .vop_close = zfsctl_common_close } },
636 { VOPNAME_IOCTL, { .error = fs_inval } },
637 { VOPNAME_GETATTR, { .vop_getattr = zfsctl_root_getattr } },
638 { VOPNAME_ACCESS, { .vop_access = zfsctl_common_access } },
639 { VOPNAME_READDIR, { .vop_readdir = gfs_vop_readdir } },
640 { VOPNAME_LOOKUP, { .vop_lookup = zfsctl_root_lookup } },
641 { VOPNAME_SEEK, { .vop_seek = fs_seek } },
642 { VOPNAME_INACTIVE, { .vop_inactive = gfs_vop_inactive } },
643 { VOPNAME_PATHCONF, { .vop_pathconf = zfsctl_pathconf } },
644 { VOPNAME_FID, { .vop_fid = zfsctl_common_fid } },
649 static struct vop_vector zfsctl_ops_root = {
650 .vop_default = &default_vnodeops,
651 .vop_open = zfsctl_common_open,
652 .vop_close = zfsctl_common_close,
653 .vop_ioctl = VOP_EINVAL,
654 .vop_getattr = zfsctl_root_getattr,
655 .vop_access = zfsctl_common_access,
656 .vop_readdir = gfs_vop_readdir,
657 .vop_lookup = zfsctl_freebsd_root_lookup,
658 .vop_inactive = VOP_NULL,
659 .vop_reclaim = gfs_vop_reclaim,
661 .vop_pathconf = zfsctl_pathconf,
663 .vop_fid = zfsctl_common_fid,
664 .vop_print = zfsctl_root_print,
668 * Gets the full dataset name that corresponds to the given snapshot name
670 * zfsctl_snapshot_zname("snap1") -> "mypool/myfs@snap1"
673 zfsctl_snapshot_zname(vnode_t *vp, const char *name, int len, char *zname)
675 objset_t *os = ((zfsvfs_t *)((vp)->v_vfsp->vfs_data))->z_os;
677 if (zfs_component_namecheck(name, NULL, NULL) != 0)
678 return (SET_ERROR(EILSEQ));
679 dmu_objset_name(os, zname);
680 if (strlen(zname) + 1 + strlen(name) >= len)
681 return (SET_ERROR(ENAMETOOLONG));
682 (void) strcat(zname, "@");
683 (void) strcat(zname, name);
688 zfsctl_unmount_snap(zfs_snapentry_t *sep, int fflags, cred_t *cr)
690 vnode_t *svp = sep->se_root;
693 ASSERT(vn_ismntpt(svp));
695 /* this will be dropped by dounmount() */
696 if ((error = vn_vfswlock(svp)) != 0)
701 error = dounmount(vn_mountedvfs(svp), fflags, cr);
708 * We can't use VN_RELE(), as that will try to invoke
709 * zfsctl_snapdir_inactive(), which would cause us to destroy
710 * the sd_lock mutex held by our caller.
712 ASSERT(svp->v_count == 1);
713 gfs_vop_reclaim(svp, cr, NULL);
715 kmem_free(sep->se_name, strlen(sep->se_name) + 1);
716 kmem_free(sep, sizeof (zfs_snapentry_t));
720 vfs_ref(vn_mountedvfs(svp));
721 return (dounmount(vn_mountedvfs(svp), fflags, curthread));
727 zfsctl_rename_snap(zfsctl_snapdir_t *sdp, zfs_snapentry_t *sep, const char *nm)
732 char newpath[MAXNAMELEN];
735 ASSERT(MUTEX_HELD(&sdp->sd_lock));
738 vfsp = vn_mountedvfs(sep->se_root);
739 ASSERT(vfsp != NULL);
744 * Change the name in the AVL tree.
746 avl_remove(&sdp->sd_snaps, sep);
747 kmem_free(sep->se_name, strlen(sep->se_name) + 1);
748 sep->se_name = kmem_alloc(strlen(nm) + 1, KM_SLEEP);
749 (void) strcpy(sep->se_name, nm);
750 VERIFY(avl_find(&sdp->sd_snaps, sep, &where) == NULL);
751 avl_insert(&sdp->sd_snaps, sep, where);
754 * Change the current mountpoint info:
755 * - update the tail of the mntpoint path
756 * - update the tail of the resource path
758 pathref = vfs_getmntpoint(vfsp);
759 (void) strncpy(newpath, refstr_value(pathref), sizeof (newpath));
760 VERIFY((tail = strrchr(newpath, '/')) != NULL);
762 ASSERT3U(strlen(newpath) + strlen(nm), <, sizeof (newpath));
763 (void) strcat(newpath, nm);
764 refstr_rele(pathref);
765 vfs_setmntpoint(vfsp, newpath, 0);
767 pathref = vfs_getresource(vfsp);
768 (void) strncpy(newpath, refstr_value(pathref), sizeof (newpath));
769 VERIFY((tail = strrchr(newpath, '@')) != NULL);
771 ASSERT3U(strlen(newpath) + strlen(nm), <, sizeof (newpath));
772 (void) strcat(newpath, nm);
773 refstr_rele(pathref);
774 vfs_setresource(vfsp, newpath, 0);
783 zfsctl_snapdir_rename(vnode_t *sdvp, char *snm, vnode_t *tdvp, char *tnm,
784 cred_t *cr, caller_context_t *ct, int flags)
786 zfsctl_snapdir_t *sdp = sdvp->v_data;
787 zfs_snapentry_t search, *sep;
790 char from[ZFS_MAX_DATASET_NAME_LEN], to[ZFS_MAX_DATASET_NAME_LEN];
791 char real[ZFS_MAX_DATASET_NAME_LEN], fsname[ZFS_MAX_DATASET_NAME_LEN];
794 zfsvfs = sdvp->v_vfsp->vfs_data;
797 if ((flags & FIGNORECASE) || zfsvfs->z_case == ZFS_CASE_INSENSITIVE) {
798 err = dmu_snapshot_realname(zfsvfs->z_os, snm, real,
799 sizeof (real), NULL);
802 } else if (err != ENOTSUP) {
810 dmu_objset_name(zfsvfs->z_os, fsname);
812 err = zfsctl_snapshot_zname(sdvp, snm, sizeof (from), from);
814 err = zfsctl_snapshot_zname(tdvp, tnm, sizeof (to), to);
816 err = zfs_secpolicy_rename_perms(from, to, cr);
821 * Cannot move snapshots out of the snapdir.
824 return (SET_ERROR(EINVAL));
826 if (strcmp(snm, tnm) == 0)
829 mutex_enter(&sdp->sd_lock);
831 search.se_name = (char *)snm;
832 if ((sep = avl_find(&sdp->sd_snaps, &search, &where)) == NULL) {
833 mutex_exit(&sdp->sd_lock);
834 return (SET_ERROR(ENOENT));
837 err = dsl_dataset_rename_snapshot(fsname, snm, tnm, 0);
839 zfsctl_rename_snap(sdp, sep, tnm);
841 mutex_exit(&sdp->sd_lock);
850 zfsctl_snapdir_remove(vnode_t *dvp, char *name, vnode_t *cwd, cred_t *cr,
851 caller_context_t *ct, int flags)
853 zfsctl_snapdir_t *sdp = dvp->v_data;
854 zfs_snapentry_t *sep;
855 zfs_snapentry_t search;
857 char snapname[ZFS_MAX_DATASET_NAME_LEN];
858 char real[ZFS_MAX_DATASET_NAME_LEN];
861 zfsvfs = dvp->v_vfsp->vfs_data;
864 if ((flags & FIGNORECASE) || zfsvfs->z_case == ZFS_CASE_INSENSITIVE) {
866 err = dmu_snapshot_realname(zfsvfs->z_os, name, real,
867 sizeof (real), NULL);
870 } else if (err != ENOTSUP) {
878 err = zfsctl_snapshot_zname(dvp, name, sizeof (snapname), snapname);
880 err = zfs_secpolicy_destroy_perms(snapname, cr);
884 mutex_enter(&sdp->sd_lock);
886 search.se_name = name;
887 sep = avl_find(&sdp->sd_snaps, &search, NULL);
889 avl_remove(&sdp->sd_snaps, sep);
890 err = zfsctl_unmount_snap(sep, MS_FORCE, cr);
892 avl_add(&sdp->sd_snaps, sep);
894 err = dsl_destroy_snapshot(snapname, B_FALSE);
896 err = SET_ERROR(ENOENT);
899 mutex_exit(&sdp->sd_lock);
906 * This creates a snapshot under '.zfs/snapshot'.
910 zfsctl_snapdir_mkdir(vnode_t *dvp, char *dirname, vattr_t *vap, vnode_t **vpp,
911 cred_t *cr, caller_context_t *cc, int flags, vsecattr_t *vsecp)
913 zfsvfs_t *zfsvfs = dvp->v_vfsp->vfs_data;
914 char name[ZFS_MAX_DATASET_NAME_LEN];
916 static enum symfollow follow = NO_FOLLOW;
917 static enum uio_seg seg = UIO_SYSSPACE;
919 if (zfs_component_namecheck(dirname, NULL, NULL) != 0)
920 return (SET_ERROR(EILSEQ));
922 dmu_objset_name(zfsvfs->z_os, name);
926 err = zfs_secpolicy_snapshot_perms(name, cr);
931 err = dmu_objset_snapshot_one(name, dirname);
934 err = lookupnameat(dirname, seg, follow, NULL, vpp, dvp);
941 zfsctl_freebsd_snapdir_mkdir(ap)
942 struct vop_mkdir_args /* {
944 struct vnode **a_vpp;
945 struct componentname *a_cnp;
950 ASSERT(ap->a_cnp->cn_flags & SAVENAME);
952 return (zfsctl_snapdir_mkdir(ap->a_dvp, ap->a_cnp->cn_nameptr, NULL,
953 ap->a_vpp, ap->a_cnp->cn_cred, NULL, 0, NULL));
957 * Lookup entry point for the 'snapshot' directory. Try to open the
958 * snapshot if it exist, creating the pseudo filesystem vnode as necessary.
959 * Perform a mount of the associated dataset on top of the vnode.
963 zfsctl_snapdir_lookup(ap)
964 struct vop_lookup_args /* {
966 struct vnode **a_vpp;
967 struct componentname *a_cnp;
970 vnode_t *dvp = ap->a_dvp;
971 vnode_t **vpp = ap->a_vpp;
972 struct componentname *cnp = ap->a_cnp;
973 char nm[NAME_MAX + 1];
974 zfsctl_snapdir_t *sdp = dvp->v_data;
976 char snapname[ZFS_MAX_DATASET_NAME_LEN];
977 char real[ZFS_MAX_DATASET_NAME_LEN];
979 zfs_snapentry_t *sep, search;
980 size_t mountpoint_len;
982 zfsvfs_t *zfsvfs = dvp->v_vfsp->vfs_data;
984 int ltype, flags = 0;
987 * No extended attributes allowed under .zfs
989 if (flags & LOOKUP_XATTR)
990 return (SET_ERROR(EINVAL));
991 ASSERT(ap->a_cnp->cn_namelen < sizeof(nm));
992 strlcpy(nm, ap->a_cnp->cn_nameptr, ap->a_cnp->cn_namelen + 1);
994 ASSERT(dvp->v_type == VDIR);
999 * If we get a recursive call, that means we got called
1000 * from the domount() code while it was trying to look up the
1001 * spec (which looks like a local path for zfs). We need to
1002 * add some flag to domount() to tell it not to do this lookup.
1004 if (MUTEX_HELD(&sdp->sd_lock))
1005 return (SET_ERROR(ENOENT));
1008 if (gfs_lookup_dot(vpp, dvp, zfsvfs->z_ctldir, nm) == 0) {
1009 if (nm[0] == '.' && nm[1] == '.' && nm[2] =='\0') {
1011 VERIFY0(vn_lock(*vpp, LK_EXCLUSIVE));
1012 VERIFY0(vn_lock(dvp, LK_EXCLUSIVE));
1018 if (flags & FIGNORECASE) {
1019 boolean_t conflict = B_FALSE;
1021 err = dmu_snapshot_realname(zfsvfs->z_os, nm, real,
1022 sizeof (real), &conflict);
1024 strlcpy(nm, real, sizeof(nm));
1025 } else if (err != ENOTSUP) {
1031 (void) strlcpy(realpnp->pn_buf, nm,
1032 realpnp->pn_bufsize);
1033 if (conflict && direntflags)
1034 *direntflags = ED_CASE_CONFLICT;
1039 mutex_enter(&sdp->sd_lock);
1040 search.se_name = (char *)nm;
1041 if ((sep = avl_find(&sdp->sd_snaps, &search, &where)) != NULL) {
1042 *vpp = sep->se_root;
1044 err = traverse(vpp, LK_EXCLUSIVE | LK_RETRY);
1047 } else if (*vpp == sep->se_root) {
1049 * The snapshot was unmounted behind our backs,
1050 * try to remount it.
1052 VERIFY(zfsctl_snapshot_zname(dvp, nm, MAXNAMELEN, snapname) == 0);
1055 mutex_exit(&sdp->sd_lock);
1061 * The requested snapshot is not currently mounted, look it up.
1063 err = zfsctl_snapshot_zname(dvp, nm, sizeof (snapname), snapname);
1065 mutex_exit(&sdp->sd_lock);
1068 * handle "ls *" or "?" in a graceful manner,
1069 * forcing EILSEQ to ENOENT.
1070 * Since shell ultimately passes "*" or "?" as name to lookup
1072 return (err == EILSEQ ? ENOENT : err);
1074 if (dmu_objset_hold(snapname, FTAG, &snap) != 0) {
1075 mutex_exit(&sdp->sd_lock);
1078 return (SET_ERROR(ENOENT));
1079 #else /* !illumos */
1080 /* Translate errors and add SAVENAME when needed. */
1081 if ((cnp->cn_flags & ISLASTCN) && cnp->cn_nameiop == CREATE) {
1083 cnp->cn_flags |= SAVENAME;
1085 err = SET_ERROR(ENOENT);
1089 #endif /* illumos */
1092 sep = kmem_alloc(sizeof (zfs_snapentry_t), KM_SLEEP);
1093 sep->se_name = kmem_alloc(strlen(nm) + 1, KM_SLEEP);
1094 (void) strcpy(sep->se_name, nm);
1095 *vpp = sep->se_root = zfsctl_snapshot_mknode(dvp, dmu_objset_id(snap));
1096 avl_insert(&sdp->sd_snaps, sep, where);
1098 dmu_objset_rele(snap, FTAG);
1100 mountpoint_len = strlen(dvp->v_vfsp->mnt_stat.f_mntonname) +
1101 strlen("/" ZFS_CTLDIR_NAME "/snapshot/") + strlen(nm) + 1;
1102 mountpoint = kmem_alloc(mountpoint_len, KM_SLEEP);
1103 (void) snprintf(mountpoint, mountpoint_len,
1104 "%s/" ZFS_CTLDIR_NAME "/snapshot/%s",
1105 dvp->v_vfsp->mnt_stat.f_mntonname, nm);
1106 mutex_exit(&sdp->sd_lock);
1109 * The vnode may get reclaimed between dropping sd_lock and
1110 * getting the vnode lock.
1112 err = vn_lock(*vpp, LK_EXCLUSIVE);
1116 err = mount_snapshot(curthread, vpp, "zfs", mountpoint, snapname, 0);
1117 kmem_free(mountpoint, mountpoint_len);
1120 * Fix up the root vnode mounted on .zfs/snapshot/<snapname>.
1122 * This is where we lie about our v_vfsp in order to
1123 * make .zfs/snapshot/<snapname> accessible over NFS
1124 * without requiring manual mounts of <snapname>.
1126 ASSERT(VTOZ(*vpp)->z_zfsvfs != zfsvfs);
1127 VTOZ(*vpp)->z_zfsvfs->z_parent = zfsvfs;
1128 (*vpp)->v_flag &= ~VROOT;
1134 * If we had an error, drop our hold on the vnode and
1135 * zfsctl_snapshot_inactive() will clean up.
1150 zfsctl_shares_lookup(ap)
1151 struct vop_lookup_args /* {
1152 struct vnode *a_dvp;
1153 struct vnode **a_vpp;
1154 struct componentname *a_cnp;
1157 vnode_t *dvp = ap->a_dvp;
1158 vnode_t **vpp = ap->a_vpp;
1159 struct componentname *cnp = ap->a_cnp;
1160 zfsvfs_t *zfsvfs = dvp->v_vfsp->vfs_data;
1161 char nm[NAME_MAX + 1];
1167 ASSERT(cnp->cn_namelen < sizeof(nm));
1168 strlcpy(nm, cnp->cn_nameptr, cnp->cn_namelen + 1);
1170 if (gfs_lookup_dot(vpp, dvp, zfsvfs->z_ctldir, nm) == 0) {
1171 if (nm[0] == '.' && nm[1] == '.' && nm[2] =='\0') {
1173 VERIFY0(vn_lock(*vpp, LK_EXCLUSIVE));
1174 VERIFY0(vn_lock(dvp, LK_EXCLUSIVE));
1180 if (zfsvfs->z_shares_dir == 0) {
1182 return (SET_ERROR(ENOTSUP));
1184 if ((error = zfs_zget(zfsvfs, zfsvfs->z_shares_dir, &dzp)) == 0) {
1185 error = VOP_LOOKUP(ZTOV(dzp), vpp, cnp);
1196 zfsctl_snapdir_readdir_cb(vnode_t *vp, void *dp, int *eofp,
1197 offset_t *offp, offset_t *nextp, void *data, int flags)
1199 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data;
1200 char snapname[ZFS_MAX_DATASET_NAME_LEN];
1201 uint64_t id, cookie;
1202 boolean_t case_conflict;
1208 dsl_pool_config_enter(dmu_objset_pool(zfsvfs->z_os), FTAG);
1209 error = dmu_snapshot_list_next(zfsvfs->z_os,
1210 sizeof (snapname), snapname, &id, &cookie, &case_conflict);
1211 dsl_pool_config_exit(dmu_objset_pool(zfsvfs->z_os), FTAG);
1214 if (error == ENOENT) {
1221 if (flags & V_RDDIR_ENTFLAGS) {
1222 edirent_t *eodp = dp;
1224 (void) strcpy(eodp->ed_name, snapname);
1225 eodp->ed_ino = ZFSCTL_INO_SNAP(id);
1226 eodp->ed_eflags = case_conflict ? ED_CASE_CONFLICT : 0;
1228 struct dirent64 *odp = dp;
1230 (void) strcpy(odp->d_name, snapname);
1231 odp->d_ino = ZFSCTL_INO_SNAP(id);
1242 zfsctl_shares_readdir(ap)
1243 struct vop_readdir_args /* {
1246 struct ucred *a_cred;
1252 vnode_t *vp = ap->a_vp;
1253 uio_t *uiop = ap->a_uio;
1254 cred_t *cr = ap->a_cred;
1255 int *eofp = ap->a_eofflag;
1256 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data;
1262 if (zfsvfs->z_shares_dir == 0) {
1264 return (SET_ERROR(ENOTSUP));
1266 if ((error = zfs_zget(zfsvfs, zfsvfs->z_shares_dir, &dzp)) == 0) {
1267 vn_lock(ZTOV(dzp), LK_SHARED | LK_RETRY);
1268 error = VOP_READDIR(ZTOV(dzp), uiop, cr, eofp, ap->a_ncookies, ap->a_cookies);
1269 VN_URELE(ZTOV(dzp));
1272 error = SET_ERROR(ENOENT);
1280 * pvp is the '.zfs' directory (zfsctl_node_t).
1282 * Creates vp, which is '.zfs/snapshot' (zfsctl_snapdir_t).
1284 * This function is the callback to create a GFS vnode for '.zfs/snapshot'
1285 * when a lookup is performed on .zfs for "snapshot".
1288 zfsctl_mknode_snapdir(vnode_t *pvp)
1291 zfsctl_snapdir_t *sdp;
1293 vp = gfs_dir_create(sizeof (zfsctl_snapdir_t), pvp, pvp->v_vfsp,
1294 &zfsctl_ops_snapdir, NULL, NULL, MAXNAMELEN,
1295 zfsctl_snapdir_readdir_cb, NULL);
1297 sdp->sd_node.zc_id = ZFSCTL_INO_SNAPDIR;
1298 sdp->sd_node.zc_cmtime = ((zfsctl_node_t *)pvp->v_data)->zc_cmtime;
1299 mutex_init(&sdp->sd_lock, NULL, MUTEX_DEFAULT, NULL);
1300 avl_create(&sdp->sd_snaps, snapentry_compare,
1301 sizeof (zfs_snapentry_t), offsetof(zfs_snapentry_t, se_node));
1307 zfsctl_mknode_shares(vnode_t *pvp)
1312 vp = gfs_dir_create(sizeof (zfsctl_node_t), pvp, pvp->v_vfsp,
1313 &zfsctl_ops_shares, NULL, NULL, MAXNAMELEN,
1316 sdp->zc_cmtime = ((zfsctl_node_t *)pvp->v_data)->zc_cmtime;
1324 zfsctl_shares_getattr(ap)
1325 struct vop_getattr_args /* {
1327 struct vattr *a_vap;
1328 struct ucred *a_cred;
1329 struct thread *a_td;
1332 vnode_t *vp = ap->a_vp;
1333 vattr_t *vap = ap->a_vap;
1334 cred_t *cr = ap->a_cred;
1335 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data;
1340 if (zfsvfs->z_shares_dir == 0) {
1342 return (SET_ERROR(ENOTSUP));
1344 if ((error = zfs_zget(zfsvfs, zfsvfs->z_shares_dir, &dzp)) == 0) {
1345 vn_lock(ZTOV(dzp), LK_SHARED | LK_RETRY);
1346 error = VOP_GETATTR(ZTOV(dzp), vap, cr);
1347 VN_URELE(ZTOV(dzp));
1357 zfsctl_snapdir_getattr(ap)
1358 struct vop_getattr_args /* {
1360 struct vattr *a_vap;
1361 struct ucred *a_cred;
1364 vnode_t *vp = ap->a_vp;
1365 vattr_t *vap = ap->a_vap;
1366 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data;
1367 zfsctl_snapdir_t *sdp = vp->v_data;
1370 zfsctl_common_getattr(vp, vap);
1371 vap->va_nodeid = gfs_file_inode(vp);
1372 vap->va_nlink = vap->va_size = avl_numnodes(&sdp->sd_snaps) + 2;
1373 vap->va_ctime = vap->va_mtime = dmu_objset_snap_cmtime(zfsvfs->z_os);
1374 vap->va_birthtime = vap->va_ctime;
1382 zfsctl_snapdir_reclaim(ap)
1383 struct vop_reclaim_args /* {
1385 struct thread *a_td;
1388 vnode_t *vp = ap->a_vp;
1389 zfsctl_snapdir_t *sdp = vp->v_data;
1390 zfs_snapentry_t *sep;
1392 ASSERT(avl_numnodes(&sdp->sd_snaps) == 0);
1393 mutex_destroy(&sdp->sd_lock);
1394 avl_destroy(&sdp->sd_snaps);
1395 gfs_vop_reclaim(ap);
1401 zfsctl_shares_print(ap)
1402 struct vop_print_args /* {
1406 printf(" .zfs/shares node\n");
1407 zfsctl_common_print(ap);
1412 zfsctl_snapdir_print(ap)
1413 struct vop_print_args /* {
1417 vnode_t *vp = ap->a_vp;
1418 zfsctl_snapdir_t *sdp = vp->v_data;
1420 printf(" .zfs/snapshot node\n");
1421 printf(" number of children = %lu\n", avl_numnodes(&sdp->sd_snaps));
1422 zfsctl_common_print(ap);
1427 static const fs_operation_def_t zfsctl_tops_snapdir[] = {
1428 { VOPNAME_OPEN, { .vop_open = zfsctl_common_open } },
1429 { VOPNAME_CLOSE, { .vop_close = zfsctl_common_close } },
1430 { VOPNAME_IOCTL, { .error = fs_inval } },
1431 { VOPNAME_GETATTR, { .vop_getattr = zfsctl_snapdir_getattr } },
1432 { VOPNAME_ACCESS, { .vop_access = zfsctl_common_access } },
1433 { VOPNAME_RENAME, { .vop_rename = zfsctl_snapdir_rename } },
1434 { VOPNAME_RMDIR, { .vop_rmdir = zfsctl_snapdir_remove } },
1435 { VOPNAME_MKDIR, { .vop_mkdir = zfsctl_snapdir_mkdir } },
1436 { VOPNAME_READDIR, { .vop_readdir = gfs_vop_readdir } },
1437 { VOPNAME_LOOKUP, { .vop_lookup = zfsctl_snapdir_lookup } },
1438 { VOPNAME_SEEK, { .vop_seek = fs_seek } },
1439 { VOPNAME_INACTIVE, { .vop_inactive = zfsctl_snapdir_inactive } },
1440 { VOPNAME_FID, { .vop_fid = zfsctl_common_fid } },
1444 static const fs_operation_def_t zfsctl_tops_shares[] = {
1445 { VOPNAME_OPEN, { .vop_open = zfsctl_common_open } },
1446 { VOPNAME_CLOSE, { .vop_close = zfsctl_common_close } },
1447 { VOPNAME_IOCTL, { .error = fs_inval } },
1448 { VOPNAME_GETATTR, { .vop_getattr = zfsctl_shares_getattr } },
1449 { VOPNAME_ACCESS, { .vop_access = zfsctl_common_access } },
1450 { VOPNAME_READDIR, { .vop_readdir = zfsctl_shares_readdir } },
1451 { VOPNAME_LOOKUP, { .vop_lookup = zfsctl_shares_lookup } },
1452 { VOPNAME_SEEK, { .vop_seek = fs_seek } },
1453 { VOPNAME_INACTIVE, { .vop_inactive = gfs_vop_inactive } },
1454 { VOPNAME_FID, { .vop_fid = zfsctl_shares_fid } },
1457 #else /* !illumos */
1458 static struct vop_vector zfsctl_ops_snapdir = {
1459 .vop_default = &default_vnodeops,
1460 .vop_open = zfsctl_common_open,
1461 .vop_close = zfsctl_common_close,
1462 .vop_ioctl = VOP_EINVAL,
1463 .vop_getattr = zfsctl_snapdir_getattr,
1464 .vop_access = zfsctl_common_access,
1465 .vop_mkdir = zfsctl_freebsd_snapdir_mkdir,
1466 .vop_readdir = gfs_vop_readdir,
1467 .vop_lookup = zfsctl_snapdir_lookup,
1468 .vop_inactive = VOP_NULL,
1469 .vop_reclaim = zfsctl_snapdir_reclaim,
1470 .vop_fid = zfsctl_common_fid,
1471 .vop_print = zfsctl_snapdir_print,
1474 static struct vop_vector zfsctl_ops_shares = {
1475 .vop_default = &default_vnodeops,
1476 .vop_open = zfsctl_common_open,
1477 .vop_close = zfsctl_common_close,
1478 .vop_ioctl = VOP_EINVAL,
1479 .vop_getattr = zfsctl_shares_getattr,
1480 .vop_access = zfsctl_common_access,
1481 .vop_readdir = zfsctl_shares_readdir,
1482 .vop_lookup = zfsctl_shares_lookup,
1483 .vop_inactive = VOP_NULL,
1484 .vop_reclaim = gfs_vop_reclaim,
1485 .vop_fid = zfsctl_shares_fid,
1486 .vop_print = zfsctl_shares_print,
1488 #endif /* illumos */
1491 * pvp is the GFS vnode '.zfs/snapshot'.
1493 * This creates a GFS node under '.zfs/snapshot' representing each
1494 * snapshot. This newly created GFS node is what we mount snapshot
1498 zfsctl_snapshot_mknode(vnode_t *pvp, uint64_t objset)
1503 vp = gfs_dir_create(sizeof (zfsctl_node_t), pvp, pvp->v_vfsp,
1504 &zfsctl_ops_snapshot, NULL, NULL, MAXNAMELEN, NULL, NULL);
1506 zcp->zc_id = objset;
1513 zfsctl_snapshot_inactive(ap)
1514 struct vop_inactive_args /* {
1516 struct thread *a_td;
1519 vnode_t *vp = ap->a_vp;
1526 zfsctl_snapshot_reclaim(ap)
1527 struct vop_reclaim_args /* {
1529 struct thread *a_td;
1532 vnode_t *vp = ap->a_vp;
1533 cred_t *cr = ap->a_td->td_ucred;
1534 zfsctl_snapdir_t *sdp;
1535 zfs_snapentry_t *sep, *next;
1539 VERIFY(gfs_dir_lookup(vp, "..", &dvp, cr, 0, NULL, NULL) == 0);
1541 /* this may already have been unmounted */
1546 if (!(locked = MUTEX_HELD(&sdp->sd_lock)))
1547 mutex_enter(&sdp->sd_lock);
1549 ASSERT(!vn_ismntpt(vp));
1551 sep = avl_first(&sdp->sd_snaps);
1552 while (sep != NULL) {
1553 next = AVL_NEXT(&sdp->sd_snaps, sep);
1555 if (sep->se_root == vp) {
1556 avl_remove(&sdp->sd_snaps, sep);
1557 kmem_free(sep->se_name, strlen(sep->se_name) + 1);
1558 kmem_free(sep, sizeof (zfs_snapentry_t));
1563 ASSERT(sep != NULL);
1566 mutex_exit(&sdp->sd_lock);
1570 * Dispose of the vnode for the snapshot mount point.
1571 * This is safe to do because once this entry has been removed
1572 * from the AVL tree, it can't be found again, so cannot become
1573 * "active". If we lookup the same name again we will end up
1574 * creating a new vnode.
1576 gfs_vop_reclaim(ap);
1582 zfsctl_snapshot_vptocnp(struct vop_vptocnp_args *ap)
1584 zfsvfs_t *zfsvfs = ap->a_vp->v_vfsp->vfs_data;
1586 zfsctl_snapdir_t *sdp;
1587 zfs_snapentry_t *sep;
1590 ASSERT(zfsvfs->z_ctldir != NULL);
1591 error = zfsctl_root_lookup(zfsvfs->z_ctldir, "snapshot", &dvp,
1592 NULL, 0, NULL, kcred, NULL, NULL, NULL);
1597 mutex_enter(&sdp->sd_lock);
1598 sep = avl_first(&sdp->sd_snaps);
1599 while (sep != NULL) {
1603 sep = AVL_NEXT(&sdp->sd_snaps, sep);
1606 mutex_exit(&sdp->sd_lock);
1611 len = strlen(sep->se_name);
1612 *ap->a_buflen -= len;
1613 bcopy(sep->se_name, ap->a_buf + *ap->a_buflen, len);
1614 mutex_exit(&sdp->sd_lock);
1624 zfsctl_snaphot_print(ap)
1625 struct vop_print_args /* {
1629 vnode_t *vp = ap->a_vp;
1630 zfsctl_node_t *zcp = vp->v_data;
1632 printf(" .zfs/snapshot/<snap> node\n");
1633 printf(" id = %ju\n", (uintmax_t)zcp->zc_id);
1634 zfsctl_common_print(ap);
1639 * These VP's should never see the light of day. They should always
1642 static struct vop_vector zfsctl_ops_snapshot = {
1643 .vop_default = &default_vnodeops,
1644 .vop_inactive = zfsctl_snapshot_inactive,
1645 .vop_reclaim = zfsctl_snapshot_reclaim,
1646 .vop_vptocnp = zfsctl_snapshot_vptocnp,
1647 .vop_print = zfsctl_snaphot_print,
1651 zfsctl_lookup_objset(vfs_t *vfsp, uint64_t objsetid, zfsvfs_t **zfsvfsp)
1653 zfsvfs_t *zfsvfs = vfsp->vfs_data;
1655 zfsctl_snapdir_t *sdp;
1657 zfs_snapentry_t *sep;
1660 ASSERT(zfsvfs->z_ctldir != NULL);
1661 error = zfsctl_root_lookup(zfsvfs->z_ctldir, "snapshot", &dvp,
1662 NULL, 0, NULL, kcred, NULL, NULL, NULL);
1667 mutex_enter(&sdp->sd_lock);
1668 sep = avl_first(&sdp->sd_snaps);
1669 while (sep != NULL) {
1672 if (zcp->zc_id == objsetid)
1675 sep = AVL_NEXT(&sdp->sd_snaps, sep);
1681 * Return the mounted root rather than the covered mount point.
1682 * Takes the GFS vnode at .zfs/snapshot/<snapshot objsetid>
1683 * and returns the ZFS vnode mounted on top of the GFS node.
1684 * This ZFS vnode is the root of the vfs for objset 'objsetid'.
1686 error = traverse(&vp, LK_SHARED | LK_RETRY);
1688 if (vp == sep->se_root) {
1689 VN_RELE(vp); /* release covered vp */
1690 error = SET_ERROR(EINVAL);
1692 *zfsvfsp = VTOZ(vp)->z_zfsvfs;
1693 VN_URELE(vp); /* put snapshot's root vp */
1696 mutex_exit(&sdp->sd_lock);
1698 error = SET_ERROR(EINVAL);
1699 mutex_exit(&sdp->sd_lock);
1708 * Unmount any snapshots for the given filesystem. This is called from
1709 * zfs_umount() - if we have a ctldir, then go through and unmount all the
1713 zfsctl_umount_snapshots(vfs_t *vfsp, int fflags, cred_t *cr)
1715 zfsvfs_t *zfsvfs = vfsp->vfs_data;
1717 zfsctl_snapdir_t *sdp;
1718 zfs_snapentry_t *sep, *next;
1721 ASSERT(zfsvfs->z_ctldir != NULL);
1722 error = zfsctl_root_lookup(zfsvfs->z_ctldir, "snapshot", &dvp,
1723 NULL, 0, NULL, cr, NULL, NULL, NULL);
1728 mutex_enter(&sdp->sd_lock);
1730 sep = avl_first(&sdp->sd_snaps);
1731 while (sep != NULL) {
1732 next = AVL_NEXT(&sdp->sd_snaps, sep);
1735 * If this snapshot is not mounted, then it must
1736 * have just been unmounted by somebody else, and
1737 * will be cleaned up by zfsctl_snapdir_inactive().
1739 if (vn_ismntpt(sep->se_root)) {
1740 error = zfsctl_unmount_snap(sep, fflags, cr);
1745 * Before reinserting snapshot to the tree,
1746 * check if it was actually removed. For example
1747 * when snapshot mount point is busy, we will
1748 * have an error here, but there will be no need
1749 * to reinsert snapshot.
1751 if (avl_find(&sdp->sd_snaps, sep, &where) == NULL)
1752 avl_insert(&sdp->sd_snaps, sep, where);
1759 mutex_exit(&sdp->sd_lock);