1 /*
2 * CDDL HEADER START
3 *
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.
7 *
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.
12 *
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]
18 *
19 * CDDL HEADER END
20 */
21 /*
22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
23 * Copyright (c) 2012, 2017 by Delphix. All rights reserved.
24 * Copyright 2015, OmniTI Computer Consulting, Inc. All rights reserved.
25 */
26
27 /*
28 * ZFS control directory (a.k.a. ".zfs")
29 *
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.
34 *
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
37 * types of objects:
38 *
39 * ctldir ------> snapshotdir -------> snapshot
40 * |
41 * |
42 * V
43 * mounted fs
44 *
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.
49 *
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.
55 *
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).
59 *
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.
66 */
67
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>
73 #include <sys/gfs.h>
74 #include <sys/stat.h>
75 #include <sys/dmu.h>
76 #include <sys/dsl_destroy.h>
77 #include <sys/dsl_deleg.h>
78 #include <sys/mount.h>
79 #include <sys/sunddi.h>
80
81 #include "zfs_namecheck.h"
82
83 typedef struct zfsctl_node {
84 gfs_dir_t zc_gfs_private;
85 uint64_t zc_id;
86 timestruc_t zc_cmtime; /* ctime and mtime, always the same */
87 } zfsctl_node_t;
88
89 typedef struct zfsctl_snapdir {
90 zfsctl_node_t sd_node;
91 kmutex_t sd_lock;
92 avl_tree_t sd_snaps;
93 } zfsctl_snapdir_t;
94
95 typedef struct {
96 char *se_name;
97 vnode_t *se_root;
98 avl_node_t se_node;
99 } zfs_snapentry_t;
100
101 static int
102 snapentry_compare(const void *a, const void *b)
103 {
104 const zfs_snapentry_t *sa = a;
105 const zfs_snapentry_t *sb = b;
106 int ret = strcmp(sa->se_name, sb->se_name);
107
108 if (ret < 0)
109 return (-1);
110 else if (ret > 0)
111 return (1);
112 else
113 return (0);
114 }
115
116 vnodeops_t *zfsctl_ops_root;
117 vnodeops_t *zfsctl_ops_snapdir;
118 vnodeops_t *zfsctl_ops_snapshot;
119 vnodeops_t *zfsctl_ops_shares;
120
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[];
125
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 *);
130
131 static gfs_opsvec_t zfsctl_opsvec[] = {
132 { ".zfs", zfsctl_tops_root, &zfsctl_ops_root },
133 { ".zfs/snapshot", zfsctl_tops_snapdir, &zfsctl_ops_snapdir },
134 { ".zfs/snapshot/vnode", zfsctl_tops_snapshot, &zfsctl_ops_snapshot },
135 { ".zfs/shares", zfsctl_tops_shares, &zfsctl_ops_shares },
136 { NULL }
137 };
138
139 /*
140 * Root directory elements. We only have two entries
141 * snapshot and shares.
142 */
143 static gfs_dirent_t zfsctl_root_entries[] = {
144 { "snapshot", zfsctl_mknode_snapdir, GFS_CACHE_VNODE },
145 { "shares", zfsctl_mknode_shares, GFS_CACHE_VNODE },
146 { NULL }
147 };
148
149 /* include . and .. in the calculation */
150 #define NROOT_ENTRIES ((sizeof (zfsctl_root_entries) / \
151 sizeof (gfs_dirent_t)) + 1)
152
153
154 /*
155 * Initialize the various GFS pieces we'll need to create and manipulate .zfs
156 * directories. This is called from the ZFS init routine, and initializes the
157 * vnode ops vectors that we'll be using.
158 */
159 void
160 zfsctl_init(void)
161 {
162 VERIFY(gfs_make_opsvec(zfsctl_opsvec) == 0);
163 }
164
165 void
166 zfsctl_fini(void)
167 {
168 /*
169 * Remove vfsctl vnode ops
170 */
171 if (zfsctl_ops_root)
172 vn_freevnodeops(zfsctl_ops_root);
173 if (zfsctl_ops_snapdir)
174 vn_freevnodeops(zfsctl_ops_snapdir);
175 if (zfsctl_ops_snapshot)
176 vn_freevnodeops(zfsctl_ops_snapshot);
177 if (zfsctl_ops_shares)
178 vn_freevnodeops(zfsctl_ops_shares);
179
180 zfsctl_ops_root = NULL;
181 zfsctl_ops_snapdir = NULL;
182 zfsctl_ops_snapshot = NULL;
183 zfsctl_ops_shares = NULL;
184 }
185
186 boolean_t
187 zfsctl_is_node(vnode_t *vp)
188 {
189 return (vn_matchops(vp, zfsctl_ops_root) ||
190 vn_matchops(vp, zfsctl_ops_snapdir) ||
191 vn_matchops(vp, zfsctl_ops_snapshot) ||
192 vn_matchops(vp, zfsctl_ops_shares));
193
194 }
195
196 /*
197 * Return the inode number associated with the 'snapshot' or
198 * 'shares' directory.
199 */
200 /* ARGSUSED */
201 static ino64_t
202 zfsctl_root_inode_cb(vnode_t *vp, int index)
203 {
204 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data;
205
206 ASSERT(index < 2);
207
208 if (index == 0)
209 return (ZFSCTL_INO_SNAPDIR);
210
211 return (zfsvfs->z_shares_dir);
212 }
213
214 /*
215 * Create the '.zfs' directory. This directory is cached as part of the VFS
216 * structure. This results in a hold on the vfs_t. The code in zfs_umount()
217 * therefore checks against a vfs_count of 2 instead of 1. This reference
218 * is removed when the ctldir is destroyed in the unmount.
219 */
220 void
221 zfsctl_create(zfsvfs_t *zfsvfs)
222 {
223 vnode_t *vp, *rvp;
224 zfsctl_node_t *zcp;
225 uint64_t crtime[2];
226
227 ASSERT(zfsvfs->z_ctldir == NULL);
228
229 vp = gfs_root_create(sizeof (zfsctl_node_t), zfsvfs->z_vfs,
230 zfsctl_ops_root, ZFSCTL_INO_ROOT, zfsctl_root_entries,
231 zfsctl_root_inode_cb, MAXNAMELEN, NULL, NULL);
232 zcp = vp->v_data;
233 zcp->zc_id = ZFSCTL_INO_ROOT;
234
235 VERIFY(VFS_ROOT(zfsvfs->z_vfs, &rvp) == 0);
236 VERIFY(0 == sa_lookup(VTOZ(rvp)->z_sa_hdl, SA_ZPL_CRTIME(zfsvfs),
237 &crtime, sizeof (crtime)));
238 ZFS_TIME_DECODE(&zcp->zc_cmtime, crtime);
239 VN_RELE(rvp);
240
241 /*
242 * We're only faking the fact that we have a root of a filesystem for
243 * the sake of the GFS interfaces. Undo the flag manipulation it did
244 * for us.
245 */
246 vp->v_flag &= ~(VROOT | VNOCACHE | VNOMAP | VNOSWAP | VNOMOUNT);
247
248 zfsvfs->z_ctldir = vp;
249 }
250
251 /*
252 * Destroy the '.zfs' directory. Only called when the filesystem is unmounted.
253 * There might still be more references if we were force unmounted, but only
254 * new zfs_inactive() calls can occur and they don't reference .zfs
255 */
256 void
257 zfsctl_destroy(zfsvfs_t *zfsvfs)
258 {
259 VN_RELE(zfsvfs->z_ctldir);
260 zfsvfs->z_ctldir = NULL;
261 }
262
263 /*
264 * Given a root znode, retrieve the associated .zfs directory.
265 * Add a hold to the vnode and return it.
266 */
267 vnode_t *
268 zfsctl_root(znode_t *zp)
269 {
270 ASSERT(zfs_has_ctldir(zp));
271 VN_HOLD(zp->z_zfsvfs->z_ctldir);
272 return (zp->z_zfsvfs->z_ctldir);
273 }
274
275 /*
276 * Common open routine. Disallow any write access.
277 */
278 /* ARGSUSED */
279 static int
280 zfsctl_common_open(vnode_t **vpp, int flags, cred_t *cr, caller_context_t *ct)
281 {
282 if (flags & FWRITE)
283 return (SET_ERROR(EACCES));
284
285 return (0);
286 }
287
288 /*
289 * Common close routine. Nothing to do here.
290 */
291 /* ARGSUSED */
292 static int
293 zfsctl_common_close(vnode_t *vpp, int flags, int count, offset_t off,
294 cred_t *cr, caller_context_t *ct)
295 {
296 return (0);
297 }
298
299 /*
300 * Common access routine. Disallow writes.
301 */
302 /* ARGSUSED */
303 static int
304 zfsctl_common_access(vnode_t *vp, int mode, int flags, cred_t *cr,
305 caller_context_t *ct)
306 {
307 if (flags & V_ACE_MASK) {
308 if (mode & ACE_ALL_WRITE_PERMS)
309 return (SET_ERROR(EACCES));
310 } else {
311 if (mode & VWRITE)
312 return (SET_ERROR(EACCES));
313 }
314
315 return (0);
316 }
317
318 /*
319 * Common getattr function. Fill in basic information.
320 */
321 static void
322 zfsctl_common_getattr(vnode_t *vp, vattr_t *vap)
323 {
324 timestruc_t now;
325
326 vap->va_uid = 0;
327 vap->va_gid = 0;
328 vap->va_rdev = 0;
329 /*
330 * We are a purely virtual object, so we have no
331 * blocksize or allocated blocks.
332 */
333 vap->va_blksize = 0;
334 vap->va_nblocks = 0;
335 vap->va_seq = 0;
336 vap->va_fsid = vp->v_vfsp->vfs_dev;
337 vap->va_mode = S_IRUSR | S_IXUSR | S_IRGRP | S_IXGRP |
338 S_IROTH | S_IXOTH;
339 vap->va_type = VDIR;
340 /*
341 * We live in the now (for atime).
342 */
343 gethrestime(&now);
344 vap->va_atime = now;
345 }
346
347 /*ARGSUSED*/
348 static int
349 zfsctl_common_fid(vnode_t *vp, fid_t *fidp, caller_context_t *ct)
350 {
351 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data;
352 zfsctl_node_t *zcp = vp->v_data;
353 uint64_t object = zcp->zc_id;
354 zfid_short_t *zfid;
355 int i;
356
357 ZFS_ENTER(zfsvfs);
358
359 if (fidp->fid_len < SHORT_FID_LEN) {
360 fidp->fid_len = SHORT_FID_LEN;
361 ZFS_EXIT(zfsvfs);
362 return (SET_ERROR(ENOSPC));
363 }
364
365 zfid = (zfid_short_t *)fidp;
366
367 zfid->zf_len = SHORT_FID_LEN;
368
369 for (i = 0; i < sizeof (zfid->zf_object); i++)
370 zfid->zf_object[i] = (uint8_t)(object >> (8 * i));
371
372 /* .zfs znodes always have a generation number of 0 */
373 for (i = 0; i < sizeof (zfid->zf_gen); i++)
374 zfid->zf_gen[i] = 0;
375
376 ZFS_EXIT(zfsvfs);
377 return (0);
378 }
379
380
381 /*ARGSUSED*/
382 static int
383 zfsctl_shares_fid(vnode_t *vp, fid_t *fidp, caller_context_t *ct)
384 {
385 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data;
386 znode_t *dzp;
387 int error;
388
389 ZFS_ENTER(zfsvfs);
390
391 if (zfsvfs->z_shares_dir == 0) {
392 ZFS_EXIT(zfsvfs);
393 return (SET_ERROR(ENOTSUP));
394 }
395
396 if ((error = zfs_zget(zfsvfs, zfsvfs->z_shares_dir, &dzp)) == 0) {
397 error = VOP_FID(ZTOV(dzp), fidp, ct);
398 VN_RELE(ZTOV(dzp));
399 }
400
401 ZFS_EXIT(zfsvfs);
402 return (error);
403 }
404 /*
405 * .zfs inode namespace
406 *
407 * We need to generate unique inode numbers for all files and directories
408 * within the .zfs pseudo-filesystem. We use the following scheme:
409 *
410 * ENTRY ZFSCTL_INODE
411 * .zfs 1
412 * .zfs/snapshot 2
413 * .zfs/snapshot/<snap> objectid(snap)
414 */
415
416 #define ZFSCTL_INO_SNAP(id) (id)
417
418 /*
419 * Get root directory attributes.
420 */
421 /* ARGSUSED */
422 static int
423 zfsctl_root_getattr(vnode_t *vp, vattr_t *vap, int flags, cred_t *cr,
424 caller_context_t *ct)
425 {
426 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data;
427 zfsctl_node_t *zcp = vp->v_data;
428
429 ZFS_ENTER(zfsvfs);
430 vap->va_nodeid = ZFSCTL_INO_ROOT;
431 vap->va_nlink = vap->va_size = NROOT_ENTRIES;
432 vap->va_mtime = vap->va_ctime = zcp->zc_cmtime;
433
434 zfsctl_common_getattr(vp, vap);
435 ZFS_EXIT(zfsvfs);
436
437 return (0);
438 }
439
440 /*
441 * Special case the handling of "..".
442 */
443 /* ARGSUSED */
444 int
445 zfsctl_root_lookup(vnode_t *dvp, char *nm, vnode_t **vpp, pathname_t *pnp,
446 int flags, vnode_t *rdir, cred_t *cr, caller_context_t *ct,
447 int *direntflags, pathname_t *realpnp)
448 {
449 zfsvfs_t *zfsvfs = dvp->v_vfsp->vfs_data;
450 int err;
451
452 /*
453 * No extended attributes allowed under .zfs
454 */
455 if (flags & LOOKUP_XATTR)
456 return (SET_ERROR(EINVAL));
457
458 ZFS_ENTER(zfsvfs);
459
460 if (strcmp(nm, "..") == 0) {
461 err = VFS_ROOT(dvp->v_vfsp, vpp);
462 } else {
463 err = gfs_vop_lookup(dvp, nm, vpp, pnp, flags, rdir,
464 cr, ct, direntflags, realpnp);
465 }
466
467 ZFS_EXIT(zfsvfs);
468
469 return (err);
470 }
471
472 static int
473 zfsctl_pathconf(vnode_t *vp, int cmd, ulong_t *valp, cred_t *cr,
474 caller_context_t *ct)
475 {
476 /*
477 * We only care about ACL_ENABLED so that libsec can
478 * display ACL correctly and not default to POSIX draft.
479 */
480 if (cmd == _PC_ACL_ENABLED) {
481 *valp = _ACL_ACE_ENABLED;
482 return (0);
483 }
484
485 return (fs_pathconf(vp, cmd, valp, cr, ct));
486 }
487
488 static const fs_operation_def_t zfsctl_tops_root[] = {
489 { VOPNAME_OPEN, { .vop_open = zfsctl_common_open } },
490 { VOPNAME_CLOSE, { .vop_close = zfsctl_common_close } },
491 { VOPNAME_IOCTL, { .error = fs_inval } },
492 { VOPNAME_GETATTR, { .vop_getattr = zfsctl_root_getattr } },
493 { VOPNAME_ACCESS, { .vop_access = zfsctl_common_access } },
494 { VOPNAME_READDIR, { .vop_readdir = gfs_vop_readdir } },
495 { VOPNAME_LOOKUP, { .vop_lookup = zfsctl_root_lookup } },
496 { VOPNAME_SEEK, { .vop_seek = fs_seek } },
497 { VOPNAME_INACTIVE, { .vop_inactive = gfs_vop_inactive } },
498 { VOPNAME_PATHCONF, { .vop_pathconf = zfsctl_pathconf } },
499 { VOPNAME_FID, { .vop_fid = zfsctl_common_fid } },
500 { NULL }
501 };
502
503 /*
504 * Gets the full dataset name that corresponds to the given snapshot name
505 * Example:
506 * zfsctl_snapshot_zname("snap1") -> "mypool/myfs@snap1"
507 */
508 static int
509 zfsctl_snapshot_zname(vnode_t *vp, const char *name, int len, char *zname)
510 {
511 objset_t *os = ((zfsvfs_t *)((vp)->v_vfsp->vfs_data))->z_os;
512
513 if (zfs_component_namecheck(name, NULL, NULL) != 0)
514 return (SET_ERROR(EILSEQ));
515 dmu_objset_name(os, zname);
516 if (strlen(zname) + 1 + strlen(name) >= len)
517 return (SET_ERROR(ENAMETOOLONG));
518 (void) strcat(zname, "@");
519 (void) strcat(zname, name);
520 return (0);
521 }
522
523 static int
524 zfsctl_unmount_snap(zfs_snapentry_t *sep, int fflags, cred_t *cr)
525 {
526 vnode_t *svp = sep->se_root;
527 int error;
528
529 ASSERT(vn_ismntpt(svp));
530
531 /* this will be dropped by dounmount() */
532 if ((error = vn_vfswlock(svp)) != 0)
533 return (error);
534
535 VN_HOLD(svp);
536 error = dounmount(vn_mountedvfs(svp), fflags, cr);
537 if (error) {
538 VN_RELE(svp);
539 return (error);
540 }
541
542 /*
543 * We can't use VN_RELE(), as that will try to invoke
544 * zfsctl_snapdir_inactive(), which would cause us to destroy
545 * the sd_lock mutex held by our caller.
546 */
547 ASSERT(svp->v_count == 1);
548 gfs_vop_inactive(svp, cr, NULL);
549
550 kmem_free(sep->se_name, strlen(sep->se_name) + 1);
551 kmem_free(sep, sizeof (zfs_snapentry_t));
552
553 return (0);
554 }
555
556 static void
557 zfsctl_rename_snap(zfsctl_snapdir_t *sdp, zfs_snapentry_t *sep, const char *nm)
558 {
559 avl_index_t where;
560 vfs_t *vfsp;
561 refstr_t *pathref;
562 char newpath[MAXNAMELEN];
563 char *tail;
564
565 ASSERT(MUTEX_HELD(&sdp->sd_lock));
566 ASSERT(sep != NULL);
567
568 vfsp = vn_mountedvfs(sep->se_root);
569 ASSERT(vfsp != NULL);
570
571 vfs_lock_wait(vfsp);
572
573 /*
574 * Change the name in the AVL tree.
575 */
576 avl_remove(&sdp->sd_snaps, sep);
577 kmem_free(sep->se_name, strlen(sep->se_name) + 1);
578 sep->se_name = kmem_alloc(strlen(nm) + 1, KM_SLEEP);
579 (void) strcpy(sep->se_name, nm);
580 VERIFY(avl_find(&sdp->sd_snaps, sep, &where) == NULL);
581 avl_insert(&sdp->sd_snaps, sep, where);
582
583 /*
584 * Change the current mountpoint info:
585 * - update the tail of the mntpoint path
586 * - update the tail of the resource path
587 */
588 pathref = vfs_getmntpoint(vfsp);
589 (void) strncpy(newpath, refstr_value(pathref), sizeof (newpath));
590 VERIFY((tail = strrchr(newpath, '/')) != NULL);
591 *(tail+1) = '\0';
592 ASSERT3U(strlen(newpath) + strlen(nm), <, sizeof (newpath));
593 (void) strcat(newpath, nm);
594 refstr_rele(pathref);
595 vfs_setmntpoint(vfsp, newpath, 0);
596
597 pathref = vfs_getresource(vfsp);
598 (void) strncpy(newpath, refstr_value(pathref), sizeof (newpath));
599 VERIFY((tail = strrchr(newpath, '@')) != NULL);
600 *(tail+1) = '\0';
601 ASSERT3U(strlen(newpath) + strlen(nm), <, sizeof (newpath));
602 (void) strcat(newpath, nm);
603 refstr_rele(pathref);
604 vfs_setresource(vfsp, newpath, 0);
605
606 vfs_unlock(vfsp);
607 }
608
609 /*ARGSUSED*/
610 static int
611 zfsctl_snapdir_rename(vnode_t *sdvp, char *snm, vnode_t *tdvp, char *tnm,
612 cred_t *cr, caller_context_t *ct, int flags)
613 {
614 zfsctl_snapdir_t *sdp = sdvp->v_data;
615 zfs_snapentry_t search, *sep;
616 zfsvfs_t *zfsvfs;
617 avl_index_t where;
618 char from[ZFS_MAX_DATASET_NAME_LEN], to[ZFS_MAX_DATASET_NAME_LEN];
619 char real[ZFS_MAX_DATASET_NAME_LEN], fsname[ZFS_MAX_DATASET_NAME_LEN];
620 int err;
621
622 zfsvfs = sdvp->v_vfsp->vfs_data;
623 ZFS_ENTER(zfsvfs);
624
625 if ((flags & FIGNORECASE) || zfsvfs->z_case == ZFS_CASE_INSENSITIVE) {
626 err = dmu_snapshot_realname(zfsvfs->z_os, snm, real,
627 sizeof (real), NULL);
628 if (err == 0) {
629 snm = real;
630 } else if (err != ENOTSUP) {
631 ZFS_EXIT(zfsvfs);
632 return (err);
633 }
634 }
635
636 ZFS_EXIT(zfsvfs);
637
638 dmu_objset_name(zfsvfs->z_os, fsname);
639
640 err = zfsctl_snapshot_zname(sdvp, snm, sizeof (from), from);
641 if (err == 0)
642 err = zfsctl_snapshot_zname(tdvp, tnm, sizeof (to), to);
643 if (err == 0)
644 err = zfs_secpolicy_rename_perms(from, to, cr);
645 if (err != 0)
646 return (err);
647
648 /*
649 * Cannot move snapshots out of the snapdir.
650 */
651 if (sdvp != tdvp)
652 return (SET_ERROR(EINVAL));
653
654 if (strcmp(snm, tnm) == 0)
655 return (0);
656
657 mutex_enter(&sdp->sd_lock);
658
659 search.se_name = (char *)snm;
660 if ((sep = avl_find(&sdp->sd_snaps, &search, &where)) == NULL) {
661 mutex_exit(&sdp->sd_lock);
662 return (SET_ERROR(ENOENT));
663 }
664
665 err = dsl_dataset_rename_snapshot(fsname, snm, tnm, B_FALSE);
666 if (err == 0)
667 zfsctl_rename_snap(sdp, sep, tnm);
668
669 mutex_exit(&sdp->sd_lock);
670
671 return (err);
672 }
673
674 /* ARGSUSED */
675 static int
676 zfsctl_snapdir_remove(vnode_t *dvp, char *name, vnode_t *cwd, cred_t *cr,
677 caller_context_t *ct, int flags)
678 {
679 zfsctl_snapdir_t *sdp = dvp->v_data;
680 zfs_snapentry_t *sep;
681 zfs_snapentry_t search;
682 zfsvfs_t *zfsvfs;
683 char snapname[ZFS_MAX_DATASET_NAME_LEN];
684 char real[ZFS_MAX_DATASET_NAME_LEN];
685 int err;
686
687 zfsvfs = dvp->v_vfsp->vfs_data;
688 ZFS_ENTER(zfsvfs);
689
690 if ((flags & FIGNORECASE) || zfsvfs->z_case == ZFS_CASE_INSENSITIVE) {
691
692 err = dmu_snapshot_realname(zfsvfs->z_os, name, real,
693 sizeof (real), NULL);
694 if (err == 0) {
695 name = real;
696 } else if (err != ENOTSUP) {
697 ZFS_EXIT(zfsvfs);
698 return (err);
699 }
700 }
701
702 ZFS_EXIT(zfsvfs);
703
704 err = zfsctl_snapshot_zname(dvp, name, sizeof (snapname), snapname);
705 if (err == 0)
706 err = zfs_secpolicy_destroy_perms(snapname, cr);
707 if (err != 0)
708 return (err);
709
710 mutex_enter(&sdp->sd_lock);
711
712 search.se_name = name;
713 sep = avl_find(&sdp->sd_snaps, &search, NULL);
714 if (sep) {
715 avl_remove(&sdp->sd_snaps, sep);
716 err = zfsctl_unmount_snap(sep, MS_FORCE, cr);
717 if (err != 0)
718 avl_add(&sdp->sd_snaps, sep);
719 else
720 err = dsl_destroy_snapshot(snapname, B_FALSE);
721 } else {
722 err = SET_ERROR(ENOENT);
723 }
724
725 mutex_exit(&sdp->sd_lock);
726
727 return (err);
728 }
729
730 /*
731 * This creates a snapshot under '.zfs/snapshot'.
732 */
733 /* ARGSUSED */
734 static int
735 zfsctl_snapdir_mkdir(vnode_t *dvp, char *dirname, vattr_t *vap, vnode_t **vpp,
736 cred_t *cr, caller_context_t *cc, int flags, vsecattr_t *vsecp)
737 {
738 zfsvfs_t *zfsvfs = dvp->v_vfsp->vfs_data;
739 char name[ZFS_MAX_DATASET_NAME_LEN];
740 int err;
741 static enum symfollow follow = NO_FOLLOW;
742 static enum uio_seg seg = UIO_SYSSPACE;
743
744 if (zfs_component_namecheck(dirname, NULL, NULL) != 0)
745 return (SET_ERROR(EILSEQ));
746
747 dmu_objset_name(zfsvfs->z_os, name);
748
749 *vpp = NULL;
750
751 err = zfs_secpolicy_snapshot_perms(name, cr);
752 if (err != 0)
753 return (err);
754
755 if (err == 0) {
756 err = dmu_objset_snapshot_one(name, dirname);
757 if (err != 0)
758 return (err);
759 err = lookupnameat(dirname, seg, follow, NULL, vpp, dvp);
760 }
761
762 return (err);
763 }
764
765 /*
766 * Lookup entry point for the 'snapshot' directory. Try to open the
767 * snapshot if it exist, creating the pseudo filesystem vnode as necessary.
768 * Perform a mount of the associated dataset on top of the vnode.
769 */
770 /* ARGSUSED */
771 static int
772 zfsctl_snapdir_lookup(vnode_t *dvp, char *nm, vnode_t **vpp, pathname_t *pnp,
773 int flags, vnode_t *rdir, cred_t *cr, caller_context_t *ct,
774 int *direntflags, pathname_t *realpnp)
775 {
776 zfsctl_snapdir_t *sdp = dvp->v_data;
777 objset_t *snap;
778 char snapname[ZFS_MAX_DATASET_NAME_LEN];
779 char real[ZFS_MAX_DATASET_NAME_LEN];
780 char *mountpoint;
781 zfs_snapentry_t *sep, search;
782 struct mounta margs;
783 vfs_t *vfsp;
784 size_t mountpoint_len;
785 avl_index_t where;
786 zfsvfs_t *zfsvfs = dvp->v_vfsp->vfs_data;
787 int err;
788
789 /*
790 * No extended attributes allowed under .zfs
791 */
792 if (flags & LOOKUP_XATTR)
793 return (SET_ERROR(EINVAL));
794
795 ASSERT(dvp->v_type == VDIR);
796
797 /*
798 * If we get a recursive call, that means we got called
799 * from the domount() code while it was trying to look up the
800 * spec (which looks like a local path for zfs). We need to
801 * add some flag to domount() to tell it not to do this lookup.
802 */
803 if (MUTEX_HELD(&sdp->sd_lock))
804 return (SET_ERROR(ENOENT));
805
806 ZFS_ENTER(zfsvfs);
807
808 if (gfs_lookup_dot(vpp, dvp, zfsvfs->z_ctldir, nm) == 0) {
809 ZFS_EXIT(zfsvfs);
810 return (0);
811 }
812
813 if (flags & FIGNORECASE) {
814 boolean_t conflict = B_FALSE;
815
816 err = dmu_snapshot_realname(zfsvfs->z_os, nm, real,
817 sizeof (real), &conflict);
818 if (err == 0) {
819 nm = real;
820 } else if (err != ENOTSUP) {
821 ZFS_EXIT(zfsvfs);
822 return (err);
823 }
824 if (realpnp)
825 (void) strlcpy(realpnp->pn_buf, nm,
826 realpnp->pn_bufsize);
827 if (conflict && direntflags)
828 *direntflags = ED_CASE_CONFLICT;
829 }
830
831 mutex_enter(&sdp->sd_lock);
832 search.se_name = (char *)nm;
833 if ((sep = avl_find(&sdp->sd_snaps, &search, &where)) != NULL) {
834 *vpp = sep->se_root;
835 VN_HOLD(*vpp);
836 err = traverse(vpp);
837 if (err != 0) {
838 VN_RELE(*vpp);
839 *vpp = NULL;
840 } else if (*vpp == sep->se_root) {
841 /*
842 * The snapshot was unmounted behind our backs,
843 * try to remount it.
844 */
845 goto domount;
846 } else {
847 /*
848 * VROOT was set during the traverse call. We need
849 * to clear it since we're pretending to be part
850 * of our parent's vfs.
851 */
852 (*vpp)->v_flag &= ~VROOT;
853 }
854 mutex_exit(&sdp->sd_lock);
855 ZFS_EXIT(zfsvfs);
856 return (err);
857 }
858
859 /*
860 * The requested snapshot is not currently mounted, look it up.
861 */
862 err = zfsctl_snapshot_zname(dvp, nm, sizeof (snapname), snapname);
863 if (err != 0) {
864 mutex_exit(&sdp->sd_lock);
865 ZFS_EXIT(zfsvfs);
866 /*
867 * handle "ls *" or "?" in a graceful manner,
868 * forcing EILSEQ to ENOENT.
869 * Since shell ultimately passes "*" or "?" as name to lookup
870 */
871 return (err == EILSEQ ? ENOENT : err);
872 }
873 if (dmu_objset_hold(snapname, FTAG, &snap) != 0) {
874 mutex_exit(&sdp->sd_lock);
875 ZFS_EXIT(zfsvfs);
876 return (SET_ERROR(ENOENT));
877 }
878
879 sep = kmem_alloc(sizeof (zfs_snapentry_t), KM_SLEEP);
880 sep->se_name = kmem_alloc(strlen(nm) + 1, KM_SLEEP);
881 (void) strcpy(sep->se_name, nm);
882 *vpp = sep->se_root = zfsctl_snapshot_mknode(dvp, dmu_objset_id(snap));
883 avl_insert(&sdp->sd_snaps, sep, where);
884
885 dmu_objset_rele(snap, FTAG);
886 domount:
887 mountpoint_len = strlen(refstr_value(dvp->v_vfsp->vfs_mntpt)) +
888 strlen("/.zfs/snapshot/") + strlen(nm) + 1;
889 mountpoint = kmem_alloc(mountpoint_len, KM_SLEEP);
890 (void) snprintf(mountpoint, mountpoint_len, "%s/.zfs/snapshot/%s",
891 refstr_value(dvp->v_vfsp->vfs_mntpt), nm);
892
893 margs.spec = snapname;
894 margs.dir = mountpoint;
895 margs.flags = MS_SYSSPACE | MS_NOMNTTAB;
896 margs.fstype = "zfs";
897 margs.dataptr = NULL;
898 margs.datalen = 0;
899 margs.optptr = NULL;
900 margs.optlen = 0;
901
902 err = domount("zfs", &margs, *vpp, kcred, &vfsp);
903 kmem_free(mountpoint, mountpoint_len);
904
905 if (err == 0) {
906 /*
907 * Return the mounted root rather than the covered mount point.
908 * Takes the GFS vnode at .zfs/snapshot/<snapname> and returns
909 * the ZFS vnode mounted on top of the GFS node. This ZFS
910 * vnode is the root of the newly created vfsp.
911 */
912 VFS_RELE(vfsp);
913 err = traverse(vpp);
914 }
915
916 if (err == 0) {
917 /*
918 * Fix up the root vnode mounted on .zfs/snapshot/<snapname>.
919 *
920 * This is where we lie about our v_vfsp in order to
921 * make .zfs/snapshot/<snapname> accessible over NFS
922 * without requiring manual mounts of <snapname>.
923 */
924 ASSERT(VTOZ(*vpp)->z_zfsvfs != zfsvfs);
925 VTOZ(*vpp)->z_zfsvfs->z_parent = zfsvfs;
926 (*vpp)->v_vfsp = zfsvfs->z_vfs;
927 (*vpp)->v_flag &= ~VROOT;
928 }
929 mutex_exit(&sdp->sd_lock);
930 ZFS_EXIT(zfsvfs);
931
932 /*
933 * If we had an error, drop our hold on the vnode and
934 * zfsctl_snapshot_inactive() will clean up.
935 */
936 if (err != 0) {
937 VN_RELE(*vpp);
938 *vpp = NULL;
939 }
940 return (err);
941 }
942
943 /* ARGSUSED */
944 static int
945 zfsctl_shares_lookup(vnode_t *dvp, char *nm, vnode_t **vpp, pathname_t *pnp,
946 int flags, vnode_t *rdir, cred_t *cr, caller_context_t *ct,
947 int *direntflags, pathname_t *realpnp)
948 {
949 zfsvfs_t *zfsvfs = dvp->v_vfsp->vfs_data;
950 znode_t *dzp;
951 int error;
952
953 ZFS_ENTER(zfsvfs);
954
955 if (gfs_lookup_dot(vpp, dvp, zfsvfs->z_ctldir, nm) == 0) {
956 ZFS_EXIT(zfsvfs);
957 return (0);
958 }
959
960 if (zfsvfs->z_shares_dir == 0) {
961 ZFS_EXIT(zfsvfs);
962 return (SET_ERROR(ENOTSUP));
963 }
964 if ((error = zfs_zget(zfsvfs, zfsvfs->z_shares_dir, &dzp)) == 0) {
965 error = VOP_LOOKUP(ZTOV(dzp), nm, vpp, pnp,
966 flags, rdir, cr, ct, direntflags, realpnp);
967 VN_RELE(ZTOV(dzp));
968 }
969
970 ZFS_EXIT(zfsvfs);
971
972 return (error);
973 }
974
975 /* ARGSUSED */
976 static int
977 zfsctl_snapdir_readdir_cb(vnode_t *vp, void *dp, int *eofp,
978 offset_t *offp, offset_t *nextp, void *data, int flags)
979 {
980 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data;
981 char snapname[ZFS_MAX_DATASET_NAME_LEN];
982 uint64_t id, cookie;
983 boolean_t case_conflict;
984 int error;
985
986 ZFS_ENTER(zfsvfs);
987
988 cookie = *offp;
989 dsl_pool_config_enter(dmu_objset_pool(zfsvfs->z_os), FTAG);
990 error = dmu_snapshot_list_next(zfsvfs->z_os,
991 sizeof (snapname), snapname, &id, &cookie, &case_conflict);
992 dsl_pool_config_exit(dmu_objset_pool(zfsvfs->z_os), FTAG);
993 if (error) {
994 ZFS_EXIT(zfsvfs);
995 if (error == ENOENT) {
996 *eofp = 1;
997 return (0);
998 }
999 return (error);
1000 }
1001
1002 if (flags & V_RDDIR_ENTFLAGS) {
1003 edirent_t *eodp = dp;
1004
1005 (void) strcpy(eodp->ed_name, snapname);
1006 eodp->ed_ino = ZFSCTL_INO_SNAP(id);
1007 eodp->ed_eflags = case_conflict ? ED_CASE_CONFLICT : 0;
1008 } else {
1009 struct dirent64 *odp = dp;
1010
1011 (void) strcpy(odp->d_name, snapname);
1012 odp->d_ino = ZFSCTL_INO_SNAP(id);
1013 }
1014 *nextp = cookie;
1015
1016 ZFS_EXIT(zfsvfs);
1017
1018 return (0);
1019 }
1020
1021 /* ARGSUSED */
1022 static int
1023 zfsctl_shares_readdir(vnode_t *vp, uio_t *uiop, cred_t *cr, int *eofp,
1024 caller_context_t *ct, int flags)
1025 {
1026 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data;
1027 znode_t *dzp;
1028 int error;
1029
1030 ZFS_ENTER(zfsvfs);
1031
1032 if (zfsvfs->z_shares_dir == 0) {
1033 ZFS_EXIT(zfsvfs);
1034 return (SET_ERROR(ENOTSUP));
1035 }
1036 if ((error = zfs_zget(zfsvfs, zfsvfs->z_shares_dir, &dzp)) == 0) {
1037 error = VOP_READDIR(ZTOV(dzp), uiop, cr, eofp, ct, flags);
1038 VN_RELE(ZTOV(dzp));
1039 } else {
1040 *eofp = 1;
1041 error = SET_ERROR(ENOENT);
1042 }
1043
1044 ZFS_EXIT(zfsvfs);
1045 return (error);
1046 }
1047
1048 /*
1049 * pvp is the '.zfs' directory (zfsctl_node_t).
1050 *
1051 * Creates vp, which is '.zfs/snapshot' (zfsctl_snapdir_t).
1052 *
1053 * This function is the callback to create a GFS vnode for '.zfs/snapshot'
1054 * when a lookup is performed on .zfs for "snapshot".
1055 */
1056 vnode_t *
1057 zfsctl_mknode_snapdir(vnode_t *pvp)
1058 {
1059 vnode_t *vp;
1060 zfsctl_snapdir_t *sdp;
1061
1062 vp = gfs_dir_create(sizeof (zfsctl_snapdir_t), pvp,
1063 zfsctl_ops_snapdir, NULL, NULL, MAXNAMELEN,
1064 zfsctl_snapdir_readdir_cb, NULL);
1065 sdp = vp->v_data;
1066 sdp->sd_node.zc_id = ZFSCTL_INO_SNAPDIR;
1067 sdp->sd_node.zc_cmtime = ((zfsctl_node_t *)pvp->v_data)->zc_cmtime;
1068 mutex_init(&sdp->sd_lock, NULL, MUTEX_DEFAULT, NULL);
1069 avl_create(&sdp->sd_snaps, snapentry_compare,
1070 sizeof (zfs_snapentry_t), offsetof(zfs_snapentry_t, se_node));
1071 return (vp);
1072 }
1073
1074 vnode_t *
1075 zfsctl_mknode_shares(vnode_t *pvp)
1076 {
1077 vnode_t *vp;
1078 zfsctl_node_t *sdp;
1079
1080 vp = gfs_dir_create(sizeof (zfsctl_node_t), pvp,
1081 zfsctl_ops_shares, NULL, NULL, MAXNAMELEN,
1082 NULL, NULL);
1083 sdp = vp->v_data;
1084 sdp->zc_cmtime = ((zfsctl_node_t *)pvp->v_data)->zc_cmtime;
1085 return (vp);
1086
1087 }
1088
1089 /* ARGSUSED */
1090 static int
1091 zfsctl_shares_getattr(vnode_t *vp, vattr_t *vap, int flags, cred_t *cr,
1092 caller_context_t *ct)
1093 {
1094 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data;
1095 znode_t *dzp;
1096 int error;
1097
1098 ZFS_ENTER(zfsvfs);
1099 if (zfsvfs->z_shares_dir == 0) {
1100 ZFS_EXIT(zfsvfs);
1101 return (SET_ERROR(ENOTSUP));
1102 }
1103 if ((error = zfs_zget(zfsvfs, zfsvfs->z_shares_dir, &dzp)) == 0) {
1104 error = VOP_GETATTR(ZTOV(dzp), vap, flags, cr, ct);
1105 VN_RELE(ZTOV(dzp));
1106 }
1107 ZFS_EXIT(zfsvfs);
1108 return (error);
1109
1110
1111 }
1112
1113 /* ARGSUSED */
1114 static int
1115 zfsctl_snapdir_getattr(vnode_t *vp, vattr_t *vap, int flags, cred_t *cr,
1116 caller_context_t *ct)
1117 {
1118 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data;
1119 zfsctl_snapdir_t *sdp = vp->v_data;
1120
1121 ZFS_ENTER(zfsvfs);
1122 zfsctl_common_getattr(vp, vap);
1123 vap->va_nodeid = gfs_file_inode(vp);
1124 vap->va_nlink = vap->va_size = avl_numnodes(&sdp->sd_snaps) + 2;
1125 vap->va_ctime = vap->va_mtime = dmu_objset_snap_cmtime(zfsvfs->z_os);
1126 ZFS_EXIT(zfsvfs);
1127
1128 return (0);
1129 }
1130
1131 /* ARGSUSED */
1132 static void
1133 zfsctl_snapdir_inactive(vnode_t *vp, cred_t *cr, caller_context_t *ct)
1134 {
1135 zfsctl_snapdir_t *sdp = vp->v_data;
1136 void *private;
1137
1138 private = gfs_dir_inactive(vp);
1139 if (private != NULL) {
1140 ASSERT(avl_numnodes(&sdp->sd_snaps) == 0);
1141 mutex_destroy(&sdp->sd_lock);
1142 avl_destroy(&sdp->sd_snaps);
1143 kmem_free(private, sizeof (zfsctl_snapdir_t));
1144 }
1145 }
1146
1147 static const fs_operation_def_t zfsctl_tops_snapdir[] = {
1148 { VOPNAME_OPEN, { .vop_open = zfsctl_common_open } },
1149 { VOPNAME_CLOSE, { .vop_close = zfsctl_common_close } },
1150 { VOPNAME_IOCTL, { .error = fs_inval } },
1151 { VOPNAME_GETATTR, { .vop_getattr = zfsctl_snapdir_getattr } },
1152 { VOPNAME_ACCESS, { .vop_access = zfsctl_common_access } },
1153 { VOPNAME_RENAME, { .vop_rename = zfsctl_snapdir_rename } },
1154 { VOPNAME_RMDIR, { .vop_rmdir = zfsctl_snapdir_remove } },
1155 { VOPNAME_MKDIR, { .vop_mkdir = zfsctl_snapdir_mkdir } },
1156 { VOPNAME_READDIR, { .vop_readdir = gfs_vop_readdir } },
1157 { VOPNAME_LOOKUP, { .vop_lookup = zfsctl_snapdir_lookup } },
1158 { VOPNAME_SEEK, { .vop_seek = fs_seek } },
1159 { VOPNAME_INACTIVE, { .vop_inactive = zfsctl_snapdir_inactive } },
1160 { VOPNAME_FID, { .vop_fid = zfsctl_common_fid } },
1161 { NULL }
1162 };
1163
1164 static const fs_operation_def_t zfsctl_tops_shares[] = {
1165 { VOPNAME_OPEN, { .vop_open = zfsctl_common_open } },
1166 { VOPNAME_CLOSE, { .vop_close = zfsctl_common_close } },
1167 { VOPNAME_IOCTL, { .error = fs_inval } },
1168 { VOPNAME_GETATTR, { .vop_getattr = zfsctl_shares_getattr } },
1169 { VOPNAME_ACCESS, { .vop_access = zfsctl_common_access } },
1170 { VOPNAME_READDIR, { .vop_readdir = zfsctl_shares_readdir } },
1171 { VOPNAME_LOOKUP, { .vop_lookup = zfsctl_shares_lookup } },
1172 { VOPNAME_SEEK, { .vop_seek = fs_seek } },
1173 { VOPNAME_INACTIVE, { .vop_inactive = gfs_vop_inactive } },
1174 { VOPNAME_FID, { .vop_fid = zfsctl_shares_fid } },
1175 { NULL }
1176 };
1177
1178 /*
1179 * pvp is the GFS vnode '.zfs/snapshot'.
1180 *
1181 * This creates a GFS node under '.zfs/snapshot' representing each
1182 * snapshot. This newly created GFS node is what we mount snapshot
1183 * vfs_t's ontop of.
1184 */
1185 static vnode_t *
1186 zfsctl_snapshot_mknode(vnode_t *pvp, uint64_t objset)
1187 {
1188 vnode_t *vp;
1189 zfsctl_node_t *zcp;
1190
1191 vp = gfs_dir_create(sizeof (zfsctl_node_t), pvp,
1192 zfsctl_ops_snapshot, NULL, NULL, MAXNAMELEN, NULL, NULL);
1193 zcp = vp->v_data;
1194 zcp->zc_id = objset;
1195
1196 return (vp);
1197 }
1198
1199 static void
1200 zfsctl_snapshot_inactive(vnode_t *vp, cred_t *cr, caller_context_t *ct)
1201 {
1202 zfsctl_snapdir_t *sdp;
1203 zfs_snapentry_t *sep, *next;
1204 vnode_t *dvp;
1205
1206 VERIFY(gfs_dir_lookup(vp, "..", &dvp, cr, 0, NULL, NULL) == 0);
1207 sdp = dvp->v_data;
1208
1209 mutex_enter(&sdp->sd_lock);
1210
1211 mutex_enter(&vp->v_lock);
1212 if (vp->v_count > 1) {
1213 VN_RELE_LOCKED(vp);
1214 mutex_exit(&vp->v_lock);
1215 mutex_exit(&sdp->sd_lock);
1216 VN_RELE(dvp);
1217 return;
1218 }
1219 mutex_exit(&vp->v_lock);
1220 ASSERT(!vn_ismntpt(vp));
1221
1222 sep = avl_first(&sdp->sd_snaps);
1223 while (sep != NULL) {
1224 next = AVL_NEXT(&sdp->sd_snaps, sep);
1225
1226 if (sep->se_root == vp) {
1227 avl_remove(&sdp->sd_snaps, sep);
1228 kmem_free(sep->se_name, strlen(sep->se_name) + 1);
1229 kmem_free(sep, sizeof (zfs_snapentry_t));
1230 break;
1231 }
1232 sep = next;
1233 }
1234 ASSERT(sep != NULL);
1235
1236 mutex_exit(&sdp->sd_lock);
1237 VN_RELE(dvp);
1238
1239 /*
1240 * Dispose of the vnode for the snapshot mount point.
1241 * This is safe to do because once this entry has been removed
1242 * from the AVL tree, it can't be found again, so cannot become
1243 * "active". If we lookup the same name again we will end up
1244 * creating a new vnode.
1245 */
1246 gfs_vop_inactive(vp, cr, ct);
1247 }
1248
1249
1250 /*
1251 * These VP's should never see the light of day. They should always
1252 * be covered.
1253 */
1254 static const fs_operation_def_t zfsctl_tops_snapshot[] = {
1255 VOPNAME_INACTIVE, { .vop_inactive = zfsctl_snapshot_inactive },
1256 NULL, NULL
1257 };
1258
1259 int
1260 zfsctl_lookup_objset(vfs_t *vfsp, uint64_t objsetid, zfsvfs_t **zfsvfsp)
1261 {
1262 zfsvfs_t *zfsvfs = vfsp->vfs_data;
1263 vnode_t *dvp, *vp;
1264 zfsctl_snapdir_t *sdp;
1265 zfsctl_node_t *zcp;
1266 zfs_snapentry_t *sep;
1267 int error;
1268
1269 ASSERT(zfsvfs->z_ctldir != NULL);
1270 error = zfsctl_root_lookup(zfsvfs->z_ctldir, "snapshot", &dvp,
1271 NULL, 0, NULL, kcred, NULL, NULL, NULL);
1272 if (error != 0)
1273 return (error);
1274 sdp = dvp->v_data;
1275
1276 mutex_enter(&sdp->sd_lock);
1277 sep = avl_first(&sdp->sd_snaps);
1278 while (sep != NULL) {
1279 vp = sep->se_root;
1280 zcp = vp->v_data;
1281 if (zcp->zc_id == objsetid)
1282 break;
1283
1284 sep = AVL_NEXT(&sdp->sd_snaps, sep);
1285 }
1286
1287 if (sep != NULL) {
1288 VN_HOLD(vp);
1289 /*
1290 * Return the mounted root rather than the covered mount point.
1291 * Takes the GFS vnode at .zfs/snapshot/<snapshot objsetid>
1292 * and returns the ZFS vnode mounted on top of the GFS node.
1293 * This ZFS vnode is the root of the vfs for objset 'objsetid'.
1294 */
1295 error = traverse(&vp);
1296 if (error == 0) {
1297 if (vp == sep->se_root)
1298 error = SET_ERROR(EINVAL);
1299 else
1300 *zfsvfsp = VTOZ(vp)->z_zfsvfs;
1301 }
1302 mutex_exit(&sdp->sd_lock);
1303 VN_RELE(vp);
1304 } else {
1305 error = SET_ERROR(EINVAL);
1306 mutex_exit(&sdp->sd_lock);
1307 }
1308
1309 VN_RELE(dvp);
1310
1311 return (error);
1312 }
1313
1314 /*
1315 * Unmount any snapshots for the given filesystem. This is called from
1316 * zfs_umount() - if we have a ctldir, then go through and unmount all the
1317 * snapshots.
1318 */
1319 int
1320 zfsctl_umount_snapshots(vfs_t *vfsp, int fflags, cred_t *cr)
1321 {
1322 zfsvfs_t *zfsvfs = vfsp->vfs_data;
1323 vnode_t *dvp;
1324 zfsctl_snapdir_t *sdp;
1325 zfs_snapentry_t *sep, *next;
1326 int error;
1327
1328 ASSERT(zfsvfs->z_ctldir != NULL);
1329 error = zfsctl_root_lookup(zfsvfs->z_ctldir, "snapshot", &dvp,
1330 NULL, 0, NULL, cr, NULL, NULL, NULL);
1331 if (error != 0)
1332 return (error);
1333 sdp = dvp->v_data;
1334
1335 mutex_enter(&sdp->sd_lock);
1336
1337 sep = avl_first(&sdp->sd_snaps);
1338 while (sep != NULL) {
1339 next = AVL_NEXT(&sdp->sd_snaps, sep);
1340
1341 /*
1342 * If this snapshot is not mounted, then it must
1343 * have just been unmounted by somebody else, and
1344 * will be cleaned up by zfsctl_snapdir_inactive().
1345 */
1346 if (vn_ismntpt(sep->se_root)) {
1347 avl_remove(&sdp->sd_snaps, sep);
1348 error = zfsctl_unmount_snap(sep, fflags, cr);
1349 if (error) {
1350 avl_add(&sdp->sd_snaps, sep);
1351 break;
1352 }
1353 }
1354 sep = next;
1355 }
1356
1357 mutex_exit(&sdp->sd_lock);
1358 VN_RELE(dvp);
1359
1360 return (error);
1361 }