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.
26 * ZFS control directory (a.k.a. ".zfs")
28 * This directory provides a common location for all ZFS meta-objects.
29 * Currently, this is only the 'snapshot' directory, but this may expand in the
30 * future. The elements are built using the GFS primitives, as the hierarchy
31 * does not actually exist on disk.
33 * For 'snapshot', we don't want to have all snapshots always mounted, because
34 * this would take up a huge amount of space in /etc/mtab. We have three
37 * ctldir ------> snapshotdir -------> snapshot
43 * The 'snapshot' node contains just enough information to lookup '..' and act
44 * as a mountpoint for the snapshot. Whenever we lookup a specific snapshot, we
45 * perform an automount of the underlying filesystem and return the
46 * corresponding vnode.
48 * All mounts are handled automatically by the kernel, but unmounts are
49 * (currently) handled from user land. The main reason is that there is no
50 * reliable way to auto-unmount the filesystem when it's "no longer in use".
51 * When the user unmounts a filesystem, we call zfsctl_unmount(), which
52 * unmounts any snapshots within the snapshot directory.
54 * The '.zfs', '.zfs/snapshot', and all directories created under
55 * '.zfs/snapshot' (ie: '.zfs/snapshot/<snapname>') are all GFS nodes and
56 * share the same vfs_t as the head filesystem (what '.zfs' lives under).
58 * File systems mounted ontop of the GFS nodes '.zfs/snapshot/<snapname>'
59 * (ie: snapshots) are ZFS nodes and have their own unique vfs_t.
60 * However, vnodes within these mounted on file systems have their v_vfsp
61 * fields set to the head filesystem to make NFS happy (see
62 * zfsctl_snapdir_lookup()). We VFS_HOLD the head filesystem's vfs_t
63 * so that it cannot be freed until all snapshots have been unmounted.
68 #include <fs/fs_subr.h>
69 #include <sys/zfs_ctldir.h>
70 #include <sys/zfs_ioctl.h>
71 #include <sys/zfs_vfsops.h>
72 #include <sys/vfs_opreg.h>
76 #include <sys/dsl_deleg.h>
77 #include <sys/mount.h>
78 #include <sys/sunddi.h>
80 #include "zfs_namecheck.h"
82 typedef struct zfsctl_node {
83 gfs_dir_t zc_gfs_private;
85 timestruc_t zc_cmtime; /* ctime and mtime, always the same */
88 typedef struct zfsctl_snapdir {
89 zfsctl_node_t sd_node;
101 snapentry_compare(const void *a, const void *b)
103 const zfs_snapentry_t *sa = a;
104 const zfs_snapentry_t *sb = b;
105 int ret = strcmp(sa->se_name, sb->se_name);
115 vnodeops_t *zfsctl_ops_root;
116 vnodeops_t *zfsctl_ops_snapdir;
117 vnodeops_t *zfsctl_ops_snapshot;
118 vnodeops_t *zfsctl_ops_shares;
119 vnodeops_t *zfsctl_ops_shares_dir;
121 static const fs_operation_def_t zfsctl_tops_root[];
122 static const fs_operation_def_t zfsctl_tops_snapdir[];
123 static const fs_operation_def_t zfsctl_tops_snapshot[];
124 static const fs_operation_def_t zfsctl_tops_shares[];
126 static vnode_t *zfsctl_mknode_snapdir(vnode_t *);
127 static vnode_t *zfsctl_mknode_shares(vnode_t *);
128 static vnode_t *zfsctl_snapshot_mknode(vnode_t *, uint64_t objset);
129 static int zfsctl_unmount_snap(zfs_snapentry_t *, int, cred_t *);
132 * Root directory elements. We only have two entries
133 * snapshot and shares.
135 static gfs_dirent_t zfsctl_root_entries[] = {
136 { "snapshot", zfsctl_mknode_snapdir, GFS_CACHE_VNODE },
137 { "shares", zfsctl_mknode_shares, GFS_CACHE_VNODE },
141 /* include . and .. in the calculation */
142 #define NROOT_ENTRIES ((sizeof (zfsctl_root_entries) / \
143 sizeof (gfs_dirent_t)) + 1)
147 * Initialize the various GFS pieces we'll need to create and manipulate .zfs
148 * directories. This is called from the ZFS init routine, and initializes the
149 * vnode ops vectors that we'll be using.
160 * Remove vfsctl vnode ops
163 vn_freevnodeops(zfsctl_ops_root);
164 if (zfsctl_ops_snapdir)
165 vn_freevnodeops(zfsctl_ops_snapdir);
166 if (zfsctl_ops_snapshot)
167 vn_freevnodeops(zfsctl_ops_snapshot);
168 if (zfsctl_ops_shares)
169 vn_freevnodeops(zfsctl_ops_shares);
170 if (zfsctl_ops_shares_dir)
171 vn_freevnodeops(zfsctl_ops_shares_dir);
173 zfsctl_ops_root = NULL;
174 zfsctl_ops_snapdir = NULL;
175 zfsctl_ops_snapshot = NULL;
176 zfsctl_ops_shares = NULL;
177 zfsctl_ops_shares_dir = NULL;
181 zfsctl_is_node(vnode_t *vp)
183 return (vn_matchops(vp, zfsctl_ops_root) ||
184 vn_matchops(vp, zfsctl_ops_snapdir) ||
185 vn_matchops(vp, zfsctl_ops_snapshot) ||
186 vn_matchops(vp, zfsctl_ops_shares) ||
187 vn_matchops(vp, zfsctl_ops_shares_dir));
192 * Return the inode number associated with the 'snapshot' or
193 * 'shares' directory.
197 zfsctl_root_inode_cb(vnode_t *vp, int index)
199 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data;
204 return (ZFSCTL_INO_SNAPDIR);
206 return (zfsvfs->z_shares_dir);
210 * Create the '.zfs' directory. This directory is cached as part of the VFS
211 * structure. This results in a hold on the vfs_t. The code in zfs_umount()
212 * therefore checks against a vfs_count of 2 instead of 1. This reference
213 * is removed when the ctldir is destroyed in the unmount.
216 zfsctl_create(zfsvfs_t *zfsvfs)
222 ASSERT(zfsvfs->z_ctldir == NULL);
224 vp = gfs_root_create(sizeof (zfsctl_node_t), zfsvfs->z_vfs,
225 zfsctl_ops_root, ZFSCTL_INO_ROOT, zfsctl_root_entries,
226 zfsctl_root_inode_cb, MAXNAMELEN, NULL, NULL);
228 zcp->zc_id = ZFSCTL_INO_ROOT;
230 VERIFY(VFS_ROOT(zfsvfs->z_vfs, &rvp) == 0);
231 VERIFY(0 == sa_lookup(VTOZ(rvp)->z_sa_hdl, SA_ZPL_CRTIME(zfsvfs),
232 &crtime, sizeof (crtime)));
233 ZFS_TIME_DECODE(&zcp->zc_cmtime, crtime);
237 * We're only faking the fact that we have a root of a filesystem for
238 * the sake of the GFS interfaces. Undo the flag manipulation it did
241 vp->v_flag &= ~(VROOT | VNOCACHE | VNOMAP | VNOSWAP | VNOMOUNT);
243 zfsvfs->z_ctldir = vp;
247 * Destroy the '.zfs' directory. Only called when the filesystem is unmounted.
248 * There might still be more references if we were force unmounted, but only
249 * new zfs_inactive() calls can occur and they don't reference .zfs
252 zfsctl_destroy(zfsvfs_t *zfsvfs)
254 VN_RELE(zfsvfs->z_ctldir);
255 zfsvfs->z_ctldir = NULL;
259 * Given a root znode, retrieve the associated .zfs directory.
260 * Add a hold to the vnode and return it.
263 zfsctl_root(znode_t *zp)
265 ASSERT(zfs_has_ctldir(zp));
266 VN_HOLD(zp->z_zfsvfs->z_ctldir);
267 return (zp->z_zfsvfs->z_ctldir);
271 * Common open routine. Disallow any write access.
275 zfsctl_common_open(vnode_t **vpp, int flags, cred_t *cr, caller_context_t *ct)
284 * Common close routine. Nothing to do here.
288 zfsctl_common_close(vnode_t *vpp, int flags, int count, offset_t off,
289 cred_t *cr, caller_context_t *ct)
295 * Common access routine. Disallow writes.
299 zfsctl_common_access(vnode_t *vp, int mode, int flags, cred_t *cr,
300 caller_context_t *ct)
302 if (flags & V_ACE_MASK) {
303 if (mode & ACE_ALL_WRITE_PERMS)
314 * Common getattr function. Fill in basic information.
317 zfsctl_common_getattr(vnode_t *vp, vattr_t *vap)
325 * We are a purely virtual object, so we have no
326 * blocksize or allocated blocks.
331 vap->va_fsid = vp->v_vfsp->vfs_dev;
332 vap->va_mode = S_IRUSR | S_IXUSR | S_IRGRP | S_IXGRP |
336 * We live in the now (for atime).
344 zfsctl_common_fid(vnode_t *vp, fid_t *fidp, caller_context_t *ct)
346 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data;
347 zfsctl_node_t *zcp = vp->v_data;
348 uint64_t object = zcp->zc_id;
354 if (fidp->fid_len < SHORT_FID_LEN) {
355 fidp->fid_len = SHORT_FID_LEN;
360 zfid = (zfid_short_t *)fidp;
362 zfid->zf_len = SHORT_FID_LEN;
364 for (i = 0; i < sizeof (zfid->zf_object); i++)
365 zfid->zf_object[i] = (uint8_t)(object >> (8 * i));
367 /* .zfs znodes always have a generation number of 0 */
368 for (i = 0; i < sizeof (zfid->zf_gen); i++)
378 zfsctl_shares_fid(vnode_t *vp, fid_t *fidp, caller_context_t *ct)
380 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data;
386 if (zfsvfs->z_shares_dir == 0) {
391 if ((error = zfs_zget(zfsvfs, zfsvfs->z_shares_dir, &dzp)) == 0) {
392 error = VOP_FID(ZTOV(dzp), fidp, ct);
400 * .zfs inode namespace
402 * We need to generate unique inode numbers for all files and directories
403 * within the .zfs pseudo-filesystem. We use the following scheme:
408 * .zfs/snapshot/<snap> objectid(snap)
411 #define ZFSCTL_INO_SNAP(id) (id)
414 * Get root directory attributes.
418 zfsctl_root_getattr(vnode_t *vp, vattr_t *vap, int flags, cred_t *cr,
419 caller_context_t *ct)
421 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data;
422 zfsctl_node_t *zcp = vp->v_data;
425 vap->va_nodeid = ZFSCTL_INO_ROOT;
426 vap->va_nlink = vap->va_size = NROOT_ENTRIES;
427 vap->va_mtime = vap->va_ctime = zcp->zc_cmtime;
429 zfsctl_common_getattr(vp, vap);
436 * Special case the handling of "..".
440 zfsctl_root_lookup(vnode_t *dvp, char *nm, vnode_t **vpp, pathname_t *pnp,
441 int flags, vnode_t *rdir, cred_t *cr, caller_context_t *ct,
442 int *direntflags, pathname_t *realpnp)
444 zfsvfs_t *zfsvfs = dvp->v_vfsp->vfs_data;
448 * No extended attributes allowed under .zfs
450 if (flags & LOOKUP_XATTR)
455 if (strcmp(nm, "..") == 0) {
456 err = VFS_ROOT(dvp->v_vfsp, vpp);
458 err = gfs_vop_lookup(dvp, nm, vpp, pnp, flags, rdir,
459 cr, ct, direntflags, realpnp);
468 zfsctl_pathconf(vnode_t *vp, int cmd, ulong_t *valp, cred_t *cr,
469 caller_context_t *ct)
472 * We only care about ACL_ENABLED so that libsec can
473 * display ACL correctly and not default to POSIX draft.
475 if (cmd == _PC_ACL_ENABLED) {
476 *valp = _ACL_ACE_ENABLED;
480 return (fs_pathconf(vp, cmd, valp, cr, ct));
483 static const fs_operation_def_t zfsctl_tops_root[] = {
484 { VOPNAME_OPEN, { .vop_open = zfsctl_common_open } },
485 { VOPNAME_CLOSE, { .vop_close = zfsctl_common_close } },
486 { VOPNAME_IOCTL, { .error = fs_inval } },
487 { VOPNAME_GETATTR, { .vop_getattr = zfsctl_root_getattr } },
488 { VOPNAME_ACCESS, { .vop_access = zfsctl_common_access } },
489 { VOPNAME_READDIR, { .vop_readdir = gfs_vop_readdir } },
490 { VOPNAME_LOOKUP, { .vop_lookup = zfsctl_root_lookup } },
491 { VOPNAME_SEEK, { .vop_seek = fs_seek } },
492 { VOPNAME_INACTIVE, { .vop_inactive = gfs_vop_inactive } },
493 { VOPNAME_PATHCONF, { .vop_pathconf = zfsctl_pathconf } },
494 { VOPNAME_FID, { .vop_fid = zfsctl_common_fid } },
499 zfsctl_snapshot_zname(vnode_t *vp, const char *name, int len, char *zname)
501 objset_t *os = ((zfsvfs_t *)((vp)->v_vfsp->vfs_data))->z_os;
503 if (snapshot_namecheck(name, NULL, NULL) != 0)
505 dmu_objset_name(os, zname);
506 if (strlen(zname) + 1 + strlen(name) >= len)
507 return (ENAMETOOLONG);
508 (void) strcat(zname, "@");
509 (void) strcat(zname, name);
514 zfsctl_unmount_snap(zfs_snapentry_t *sep, int fflags, cred_t *cr)
516 vnode_t *svp = sep->se_root;
519 ASSERT(vn_ismntpt(svp));
521 /* this will be dropped by dounmount() */
522 if ((error = vn_vfswlock(svp)) != 0)
526 error = dounmount(vn_mountedvfs(svp), fflags, cr);
533 * We can't use VN_RELE(), as that will try to invoke
534 * zfsctl_snapdir_inactive(), which would cause us to destroy
535 * the sd_lock mutex held by our caller.
537 ASSERT(svp->v_count == 1);
538 gfs_vop_inactive(svp, cr, NULL);
540 kmem_free(sep->se_name, strlen(sep->se_name) + 1);
541 kmem_free(sep, sizeof (zfs_snapentry_t));
547 zfsctl_rename_snap(zfsctl_snapdir_t *sdp, zfs_snapentry_t *sep, const char *nm)
552 char newpath[MAXNAMELEN];
555 ASSERT(MUTEX_HELD(&sdp->sd_lock));
558 vfsp = vn_mountedvfs(sep->se_root);
559 ASSERT(vfsp != NULL);
564 * Change the name in the AVL tree.
566 avl_remove(&sdp->sd_snaps, sep);
567 kmem_free(sep->se_name, strlen(sep->se_name) + 1);
568 sep->se_name = kmem_alloc(strlen(nm) + 1, KM_SLEEP);
569 (void) strcpy(sep->se_name, nm);
570 VERIFY(avl_find(&sdp->sd_snaps, sep, &where) == NULL);
571 avl_insert(&sdp->sd_snaps, sep, where);
574 * Change the current mountpoint info:
575 * - update the tail of the mntpoint path
576 * - update the tail of the resource path
578 pathref = vfs_getmntpoint(vfsp);
579 (void) strncpy(newpath, refstr_value(pathref), sizeof (newpath));
580 VERIFY((tail = strrchr(newpath, '/')) != NULL);
582 ASSERT3U(strlen(newpath) + strlen(nm), <, sizeof (newpath));
583 (void) strcat(newpath, nm);
584 refstr_rele(pathref);
585 vfs_setmntpoint(vfsp, newpath, 0);
587 pathref = vfs_getresource(vfsp);
588 (void) strncpy(newpath, refstr_value(pathref), sizeof (newpath));
589 VERIFY((tail = strrchr(newpath, '@')) != NULL);
591 ASSERT3U(strlen(newpath) + strlen(nm), <, sizeof (newpath));
592 (void) strcat(newpath, nm);
593 refstr_rele(pathref);
594 vfs_setresource(vfsp, newpath, 0);
601 zfsctl_snapdir_rename(vnode_t *sdvp, char *snm, vnode_t *tdvp, char *tnm,
602 cred_t *cr, caller_context_t *ct, int flags)
604 zfsctl_snapdir_t *sdp = sdvp->v_data;
605 zfs_snapentry_t search, *sep;
608 char from[MAXNAMELEN], to[MAXNAMELEN];
609 char real[MAXNAMELEN];
612 zfsvfs = sdvp->v_vfsp->vfs_data;
615 if ((flags & FIGNORECASE) || zfsvfs->z_case == ZFS_CASE_INSENSITIVE) {
616 err = dmu_snapshot_realname(zfsvfs->z_os, snm, real,
620 } else if (err != ENOTSUP) {
628 err = zfsctl_snapshot_zname(sdvp, snm, MAXNAMELEN, from);
630 err = zfsctl_snapshot_zname(tdvp, tnm, MAXNAMELEN, to);
632 err = zfs_secpolicy_rename_perms(from, to, cr);
637 * Cannot move snapshots out of the snapdir.
642 if (strcmp(snm, tnm) == 0)
645 mutex_enter(&sdp->sd_lock);
647 search.se_name = (char *)snm;
648 if ((sep = avl_find(&sdp->sd_snaps, &search, &where)) == NULL) {
649 mutex_exit(&sdp->sd_lock);
653 err = dmu_objset_rename(from, to, B_FALSE);
655 zfsctl_rename_snap(sdp, sep, tnm);
657 mutex_exit(&sdp->sd_lock);
664 zfsctl_snapdir_remove(vnode_t *dvp, char *name, vnode_t *cwd, cred_t *cr,
665 caller_context_t *ct, int flags)
667 zfsctl_snapdir_t *sdp = dvp->v_data;
668 zfs_snapentry_t *sep;
669 zfs_snapentry_t search;
671 char snapname[MAXNAMELEN];
672 char real[MAXNAMELEN];
675 zfsvfs = dvp->v_vfsp->vfs_data;
678 if ((flags & FIGNORECASE) || zfsvfs->z_case == ZFS_CASE_INSENSITIVE) {
680 err = dmu_snapshot_realname(zfsvfs->z_os, name, real,
684 } else if (err != ENOTSUP) {
692 err = zfsctl_snapshot_zname(dvp, name, MAXNAMELEN, snapname);
694 err = zfs_secpolicy_destroy_perms(snapname, cr);
698 mutex_enter(&sdp->sd_lock);
700 search.se_name = name;
701 sep = avl_find(&sdp->sd_snaps, &search, NULL);
703 avl_remove(&sdp->sd_snaps, sep);
704 err = zfsctl_unmount_snap(sep, MS_FORCE, cr);
706 avl_add(&sdp->sd_snaps, sep);
708 err = dmu_objset_destroy(snapname, B_FALSE);
713 mutex_exit(&sdp->sd_lock);
719 * This creates a snapshot under '.zfs/snapshot'.
723 zfsctl_snapdir_mkdir(vnode_t *dvp, char *dirname, vattr_t *vap, vnode_t **vpp,
724 cred_t *cr, caller_context_t *cc, int flags, vsecattr_t *vsecp)
726 zfsvfs_t *zfsvfs = dvp->v_vfsp->vfs_data;
727 char name[MAXNAMELEN];
729 static enum symfollow follow = NO_FOLLOW;
730 static enum uio_seg seg = UIO_SYSSPACE;
732 if (snapshot_namecheck(dirname, NULL, NULL) != 0)
735 dmu_objset_name(zfsvfs->z_os, name);
739 err = zfs_secpolicy_snapshot_perms(name, cr);
744 err = dmu_objset_snapshot(name, dirname, NULL, NULL,
745 B_FALSE, B_FALSE, -1);
748 err = lookupnameat(dirname, seg, follow, NULL, vpp, dvp);
755 * Lookup entry point for the 'snapshot' directory. Try to open the
756 * snapshot if it exist, creating the pseudo filesystem vnode as necessary.
757 * Perform a mount of the associated dataset on top of the vnode.
761 zfsctl_snapdir_lookup(vnode_t *dvp, char *nm, vnode_t **vpp, pathname_t *pnp,
762 int flags, vnode_t *rdir, cred_t *cr, caller_context_t *ct,
763 int *direntflags, pathname_t *realpnp)
765 zfsctl_snapdir_t *sdp = dvp->v_data;
767 char snapname[MAXNAMELEN];
768 char real[MAXNAMELEN];
770 zfs_snapentry_t *sep, search;
773 size_t mountpoint_len;
775 zfsvfs_t *zfsvfs = dvp->v_vfsp->vfs_data;
779 * No extended attributes allowed under .zfs
781 if (flags & LOOKUP_XATTR)
784 ASSERT(dvp->v_type == VDIR);
787 * If we get a recursive call, that means we got called
788 * from the domount() code while it was trying to look up the
789 * spec (which looks like a local path for zfs). We need to
790 * add some flag to domount() to tell it not to do this lookup.
792 if (MUTEX_HELD(&sdp->sd_lock))
797 if (gfs_lookup_dot(vpp, dvp, zfsvfs->z_ctldir, nm) == 0) {
802 if (flags & FIGNORECASE) {
803 boolean_t conflict = B_FALSE;
805 err = dmu_snapshot_realname(zfsvfs->z_os, nm, real,
806 MAXNAMELEN, &conflict);
809 } else if (err != ENOTSUP) {
814 (void) strlcpy(realpnp->pn_buf, nm,
815 realpnp->pn_bufsize);
816 if (conflict && direntflags)
817 *direntflags = ED_CASE_CONFLICT;
820 mutex_enter(&sdp->sd_lock);
821 search.se_name = (char *)nm;
822 if ((sep = avl_find(&sdp->sd_snaps, &search, &where)) != NULL) {
829 } else if (*vpp == sep->se_root) {
831 * The snapshot was unmounted behind our backs,
837 * VROOT was set during the traverse call. We need
838 * to clear it since we're pretending to be part
839 * of our parent's vfs.
841 (*vpp)->v_flag &= ~VROOT;
843 mutex_exit(&sdp->sd_lock);
849 * The requested snapshot is not currently mounted, look it up.
851 err = zfsctl_snapshot_zname(dvp, nm, MAXNAMELEN, snapname);
853 mutex_exit(&sdp->sd_lock);
856 * handle "ls *" or "?" in a graceful manner,
857 * forcing EILSEQ to ENOENT.
858 * Since shell ultimately passes "*" or "?" as name to lookup
860 return (err == EILSEQ ? ENOENT : err);
862 if (dmu_objset_hold(snapname, FTAG, &snap) != 0) {
863 mutex_exit(&sdp->sd_lock);
868 sep = kmem_alloc(sizeof (zfs_snapentry_t), KM_SLEEP);
869 sep->se_name = kmem_alloc(strlen(nm) + 1, KM_SLEEP);
870 (void) strcpy(sep->se_name, nm);
871 *vpp = sep->se_root = zfsctl_snapshot_mknode(dvp, dmu_objset_id(snap));
872 avl_insert(&sdp->sd_snaps, sep, where);
874 dmu_objset_rele(snap, FTAG);
876 mountpoint_len = strlen(refstr_value(dvp->v_vfsp->vfs_mntpt)) +
877 strlen("/.zfs/snapshot/") + strlen(nm) + 1;
878 mountpoint = kmem_alloc(mountpoint_len, KM_SLEEP);
879 (void) snprintf(mountpoint, mountpoint_len, "%s/.zfs/snapshot/%s",
880 refstr_value(dvp->v_vfsp->vfs_mntpt), nm);
882 margs.spec = snapname;
883 margs.dir = mountpoint;
884 margs.flags = MS_SYSSPACE | MS_NOMNTTAB;
885 margs.fstype = "zfs";
886 margs.dataptr = NULL;
891 err = domount("zfs", &margs, *vpp, kcred, &vfsp);
892 kmem_free(mountpoint, mountpoint_len);
896 * Return the mounted root rather than the covered mount point.
897 * Takes the GFS vnode at .zfs/snapshot/<snapname> and returns
898 * the ZFS vnode mounted on top of the GFS node. This ZFS
899 * vnode is the root of the newly created vfsp.
907 * Fix up the root vnode mounted on .zfs/snapshot/<snapname>.
909 * This is where we lie about our v_vfsp in order to
910 * make .zfs/snapshot/<snapname> accessible over NFS
911 * without requiring manual mounts of <snapname>.
913 ASSERT(VTOZ(*vpp)->z_zfsvfs != zfsvfs);
914 VTOZ(*vpp)->z_zfsvfs->z_parent = zfsvfs;
915 (*vpp)->v_vfsp = zfsvfs->z_vfs;
916 (*vpp)->v_flag &= ~VROOT;
918 mutex_exit(&sdp->sd_lock);
922 * If we had an error, drop our hold on the vnode and
923 * zfsctl_snapshot_inactive() will clean up.
934 zfsctl_shares_lookup(vnode_t *dvp, char *nm, vnode_t **vpp, pathname_t *pnp,
935 int flags, vnode_t *rdir, cred_t *cr, caller_context_t *ct,
936 int *direntflags, pathname_t *realpnp)
938 zfsvfs_t *zfsvfs = dvp->v_vfsp->vfs_data;
944 if (gfs_lookup_dot(vpp, dvp, zfsvfs->z_ctldir, nm) == 0) {
949 if (zfsvfs->z_shares_dir == 0) {
953 if ((error = zfs_zget(zfsvfs, zfsvfs->z_shares_dir, &dzp)) == 0)
954 error = VOP_LOOKUP(ZTOV(dzp), nm, vpp, pnp,
955 flags, rdir, cr, ct, direntflags, realpnp);
965 zfsctl_snapdir_readdir_cb(vnode_t *vp, void *dp, int *eofp,
966 offset_t *offp, offset_t *nextp, void *data, int flags)
968 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data;
969 char snapname[MAXNAMELEN];
971 boolean_t case_conflict;
977 error = dmu_snapshot_list_next(zfsvfs->z_os, MAXNAMELEN, snapname, &id,
978 &cookie, &case_conflict);
981 if (error == ENOENT) {
988 if (flags & V_RDDIR_ENTFLAGS) {
989 edirent_t *eodp = dp;
991 (void) strcpy(eodp->ed_name, snapname);
992 eodp->ed_ino = ZFSCTL_INO_SNAP(id);
993 eodp->ed_eflags = case_conflict ? ED_CASE_CONFLICT : 0;
995 struct dirent64 *odp = dp;
997 (void) strcpy(odp->d_name, snapname);
998 odp->d_ino = ZFSCTL_INO_SNAP(id);
1009 zfsctl_shares_readdir(vnode_t *vp, uio_t *uiop, cred_t *cr, int *eofp,
1010 caller_context_t *ct, int flags)
1012 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data;
1018 if (zfsvfs->z_shares_dir == 0) {
1022 if ((error = zfs_zget(zfsvfs, zfsvfs->z_shares_dir, &dzp)) == 0) {
1023 error = VOP_READDIR(ZTOV(dzp), uiop, cr, eofp, ct, flags);
1035 * pvp is the '.zfs' directory (zfsctl_node_t).
1036 * Creates vp, which is '.zfs/snapshot' (zfsctl_snapdir_t).
1038 * This function is the callback to create a GFS vnode for '.zfs/snapshot'
1039 * when a lookup is performed on .zfs for "snapshot".
1042 zfsctl_mknode_snapdir(vnode_t *pvp)
1045 zfsctl_snapdir_t *sdp;
1047 vp = gfs_dir_create(sizeof (zfsctl_snapdir_t), pvp,
1048 zfsctl_ops_snapdir, NULL, NULL, MAXNAMELEN,
1049 zfsctl_snapdir_readdir_cb, NULL);
1051 sdp->sd_node.zc_id = ZFSCTL_INO_SNAPDIR;
1052 sdp->sd_node.zc_cmtime = ((zfsctl_node_t *)pvp->v_data)->zc_cmtime;
1053 mutex_init(&sdp->sd_lock, NULL, MUTEX_DEFAULT, NULL);
1054 avl_create(&sdp->sd_snaps, snapentry_compare,
1055 sizeof (zfs_snapentry_t), offsetof(zfs_snapentry_t, se_node));
1060 zfsctl_mknode_shares(vnode_t *pvp)
1065 vp = gfs_dir_create(sizeof (zfsctl_node_t), pvp,
1066 zfsctl_ops_shares, NULL, NULL, MAXNAMELEN,
1069 sdp->zc_cmtime = ((zfsctl_node_t *)pvp->v_data)->zc_cmtime;
1076 zfsctl_shares_getattr(vnode_t *vp, vattr_t *vap, int flags, cred_t *cr,
1077 caller_context_t *ct)
1079 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data;
1084 if (zfsvfs->z_shares_dir == 0) {
1088 if ((error = zfs_zget(zfsvfs, zfsvfs->z_shares_dir, &dzp)) == 0) {
1089 error = VOP_GETATTR(ZTOV(dzp), vap, flags, cr, ct);
1100 zfsctl_snapdir_getattr(vnode_t *vp, vattr_t *vap, int flags, cred_t *cr,
1101 caller_context_t *ct)
1103 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data;
1104 zfsctl_snapdir_t *sdp = vp->v_data;
1107 zfsctl_common_getattr(vp, vap);
1108 vap->va_nodeid = gfs_file_inode(vp);
1109 vap->va_nlink = vap->va_size = avl_numnodes(&sdp->sd_snaps) + 2;
1110 vap->va_ctime = vap->va_mtime = dmu_objset_snap_cmtime(zfsvfs->z_os);
1118 zfsctl_snapdir_inactive(vnode_t *vp, cred_t *cr, caller_context_t *ct)
1120 zfsctl_snapdir_t *sdp = vp->v_data;
1123 private = gfs_dir_inactive(vp);
1124 if (private != NULL) {
1125 ASSERT(avl_numnodes(&sdp->sd_snaps) == 0);
1126 mutex_destroy(&sdp->sd_lock);
1127 avl_destroy(&sdp->sd_snaps);
1128 kmem_free(private, sizeof (zfsctl_snapdir_t));
1132 static const fs_operation_def_t zfsctl_tops_snapdir[] = {
1133 { VOPNAME_OPEN, { .vop_open = zfsctl_common_open } },
1134 { VOPNAME_CLOSE, { .vop_close = zfsctl_common_close } },
1135 { VOPNAME_IOCTL, { .error = fs_inval } },
1136 { VOPNAME_GETATTR, { .vop_getattr = zfsctl_snapdir_getattr } },
1137 { VOPNAME_ACCESS, { .vop_access = zfsctl_common_access } },
1138 { VOPNAME_RENAME, { .vop_rename = zfsctl_snapdir_rename } },
1139 { VOPNAME_RMDIR, { .vop_rmdir = zfsctl_snapdir_remove } },
1140 { VOPNAME_MKDIR, { .vop_mkdir = zfsctl_snapdir_mkdir } },
1141 { VOPNAME_READDIR, { .vop_readdir = gfs_vop_readdir } },
1142 { VOPNAME_LOOKUP, { .vop_lookup = zfsctl_snapdir_lookup } },
1143 { VOPNAME_SEEK, { .vop_seek = fs_seek } },
1144 { VOPNAME_INACTIVE, { .vop_inactive = zfsctl_snapdir_inactive } },
1145 { VOPNAME_FID, { .vop_fid = zfsctl_common_fid } },
1149 static const fs_operation_def_t zfsctl_tops_shares[] = {
1150 { VOPNAME_OPEN, { .vop_open = zfsctl_common_open } },
1151 { VOPNAME_CLOSE, { .vop_close = zfsctl_common_close } },
1152 { VOPNAME_IOCTL, { .error = fs_inval } },
1153 { VOPNAME_GETATTR, { .vop_getattr = zfsctl_shares_getattr } },
1154 { VOPNAME_ACCESS, { .vop_access = zfsctl_common_access } },
1155 { VOPNAME_READDIR, { .vop_readdir = zfsctl_shares_readdir } },
1156 { VOPNAME_LOOKUP, { .vop_lookup = zfsctl_shares_lookup } },
1157 { VOPNAME_SEEK, { .vop_seek = fs_seek } },
1158 { VOPNAME_INACTIVE, { .vop_inactive = gfs_vop_inactive } },
1159 { VOPNAME_FID, { .vop_fid = zfsctl_shares_fid } },
1164 * pvp is the GFS vnode '.zfs/snapshot'.
1166 * This creates a GFS node under '.zfs/snapshot' representing each
1167 * snapshot. This newly created GFS node is what we mount snapshot
1171 zfsctl_snapshot_mknode(vnode_t *pvp, uint64_t objset)
1176 vp = gfs_dir_create(sizeof (zfsctl_node_t), pvp,
1177 zfsctl_ops_snapshot, NULL, NULL, MAXNAMELEN, NULL, NULL);
1179 zcp->zc_id = objset;
1185 zfsctl_snapshot_inactive(vnode_t *vp, cred_t *cr, caller_context_t *ct)
1187 zfsctl_snapdir_t *sdp;
1188 zfs_snapentry_t *sep, *next;
1191 VERIFY(gfs_dir_lookup(vp, "..", &dvp, cr, 0, NULL, NULL) == 0);
1194 mutex_enter(&sdp->sd_lock);
1196 if (vp->v_count > 1) {
1197 mutex_exit(&sdp->sd_lock);
1200 ASSERT(!vn_ismntpt(vp));
1202 sep = avl_first(&sdp->sd_snaps);
1203 while (sep != NULL) {
1204 next = AVL_NEXT(&sdp->sd_snaps, sep);
1206 if (sep->se_root == vp) {
1207 avl_remove(&sdp->sd_snaps, sep);
1208 kmem_free(sep->se_name, strlen(sep->se_name) + 1);
1209 kmem_free(sep, sizeof (zfs_snapentry_t));
1214 ASSERT(sep != NULL);
1216 mutex_exit(&sdp->sd_lock);
1220 * Dispose of the vnode for the snapshot mount point.
1221 * This is safe to do because once this entry has been removed
1222 * from the AVL tree, it can't be found again, so cannot become
1223 * "active". If we lookup the same name again we will end up
1224 * creating a new vnode.
1226 gfs_vop_inactive(vp, cr, ct);
1231 * These VP's should never see the light of day. They should always
1234 static const fs_operation_def_t zfsctl_tops_snapshot[] = {
1235 VOPNAME_INACTIVE, { .vop_inactive = zfsctl_snapshot_inactive },
1240 zfsctl_lookup_objset(vfs_t *vfsp, uint64_t objsetid, zfsvfs_t **zfsvfsp)
1242 zfsvfs_t *zfsvfs = vfsp->vfs_data;
1244 zfsctl_snapdir_t *sdp;
1246 zfs_snapentry_t *sep;
1249 ASSERT(zfsvfs->z_ctldir != NULL);
1250 error = zfsctl_root_lookup(zfsvfs->z_ctldir, "snapshot", &dvp,
1251 NULL, 0, NULL, kcred, NULL, NULL, NULL);
1256 mutex_enter(&sdp->sd_lock);
1257 sep = avl_first(&sdp->sd_snaps);
1258 while (sep != NULL) {
1261 if (zcp->zc_id == objsetid)
1264 sep = AVL_NEXT(&sdp->sd_snaps, sep);
1270 * Return the mounted root rather than the covered mount point.
1271 * Takes the GFS vnode at .zfs/snapshot/<snapshot objsetid>
1272 * and returns the ZFS vnode mounted on top of the GFS node.
1273 * This ZFS vnode is the root of the vfs for objset 'objsetid'.
1275 error = traverse(&vp);
1277 if (vp == sep->se_root)
1280 *zfsvfsp = VTOZ(vp)->z_zfsvfs;
1282 mutex_exit(&sdp->sd_lock);
1286 mutex_exit(&sdp->sd_lock);
1295 * Unmount any snapshots for the given filesystem. This is called from
1296 * zfs_umount() - if we have a ctldir, then go through and unmount all the
1300 zfsctl_umount_snapshots(vfs_t *vfsp, int fflags, cred_t *cr)
1302 zfsvfs_t *zfsvfs = vfsp->vfs_data;
1304 zfsctl_snapdir_t *sdp;
1305 zfs_snapentry_t *sep, *next;
1308 ASSERT(zfsvfs->z_ctldir != NULL);
1309 error = zfsctl_root_lookup(zfsvfs->z_ctldir, "snapshot", &dvp,
1310 NULL, 0, NULL, cr, NULL, NULL, NULL);
1315 mutex_enter(&sdp->sd_lock);
1317 sep = avl_first(&sdp->sd_snaps);
1318 while (sep != NULL) {
1319 next = AVL_NEXT(&sdp->sd_snaps, sep);
1322 * If this snapshot is not mounted, then it must
1323 * have just been unmounted by somebody else, and
1324 * will be cleaned up by zfsctl_snapdir_inactive().
1326 if (vn_ismntpt(sep->se_root)) {
1327 avl_remove(&sdp->sd_snaps, sep);
1328 error = zfsctl_unmount_snap(sep, fflags, cr);
1330 avl_add(&sdp->sd_snaps, sep);
1337 mutex_exit(&sdp->sd_lock);
1342 #endif /* HAVE_ZPL */