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, 2015 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 vnodeops_t *zfsctl_ops_shares_dir;
121
122 static const fs_operation_def_t zfsctl_tops_root[];
123 static const fs_operation_def_t zfsctl_tops_snapdir[];
124 static const fs_operation_def_t zfsctl_tops_snapshot[];
125 static const fs_operation_def_t zfsctl_tops_shares[];
126
127 static vnode_t *zfsctl_mknode_snapdir(vnode_t *);
128 static vnode_t *zfsctl_mknode_shares(vnode_t *);
129 static vnode_t *zfsctl_snapshot_mknode(vnode_t *, uint64_t objset);
130 static int zfsctl_unmount_snap(zfs_snapentry_t *, int, cred_t *);
131
132 static gfs_opsvec_t zfsctl_opsvec[] = {
133 { ".zfs", zfsctl_tops_root, &zfsctl_ops_root },
134 { ".zfs/snapshot", zfsctl_tops_snapdir, &zfsctl_ops_snapdir },
135 { ".zfs/snapshot/vnode", zfsctl_tops_snapshot, &zfsctl_ops_snapshot },
136 { ".zfs/shares", zfsctl_tops_shares, &zfsctl_ops_shares_dir },
137 { ".zfs/shares/vnode", zfsctl_tops_shares, &zfsctl_ops_shares },
138 { NULL }
139 };
140
141 /*
142 * Root directory elements. We only have two entries
143 * snapshot and shares.
144 */
145 static gfs_dirent_t zfsctl_root_entries[] = {
146 { "snapshot", zfsctl_mknode_snapdir, GFS_CACHE_VNODE },
147 { "shares", zfsctl_mknode_shares, GFS_CACHE_VNODE },
148 { NULL }
149 };
150
151 /* include . and .. in the calculation */
152 #define NROOT_ENTRIES ((sizeof (zfsctl_root_entries) / \
153 sizeof (gfs_dirent_t)) + 1)
154
155
156 /*
157 * Initialize the various GFS pieces we'll need to create and manipulate .zfs
158 * directories. This is called from the ZFS init routine, and initializes the
159 * vnode ops vectors that we'll be using.
160 */
161 void
162 zfsctl_init(void)
163 {
164 VERIFY(gfs_make_opsvec(zfsctl_opsvec) == 0);
165 }
166
167 void
168 zfsctl_fini(void)
169 {
170 /*
171 * Remove vfsctl vnode ops
172 */
173 if (zfsctl_ops_root)
174 vn_freevnodeops(zfsctl_ops_root);
175 if (zfsctl_ops_snapdir)
176 vn_freevnodeops(zfsctl_ops_snapdir);
177 if (zfsctl_ops_snapshot)
178 vn_freevnodeops(zfsctl_ops_snapshot);
179 if (zfsctl_ops_shares)
180 vn_freevnodeops(zfsctl_ops_shares);
181 if (zfsctl_ops_shares_dir)
182 vn_freevnodeops(zfsctl_ops_shares_dir);
183
184 zfsctl_ops_root = NULL;
185 zfsctl_ops_snapdir = NULL;
186 zfsctl_ops_snapshot = NULL;
187 zfsctl_ops_shares = NULL;
188 zfsctl_ops_shares_dir = NULL;
189 }
190
191 boolean_t
192 zfsctl_is_node(vnode_t *vp)
193 {
194 return (vn_matchops(vp, zfsctl_ops_root) ||
195 vn_matchops(vp, zfsctl_ops_snapdir) ||
196 vn_matchops(vp, zfsctl_ops_snapshot) ||
197 vn_matchops(vp, zfsctl_ops_shares) ||
198 vn_matchops(vp, zfsctl_ops_shares_dir));
199
200 }
201
202 /*
203 * Return the inode number associated with the 'snapshot' or
204 * 'shares' directory.
205 */
206 /* ARGSUSED */
207 static ino64_t
208 zfsctl_root_inode_cb(vnode_t *vp, int index)
209 {
210 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data;
211
212 ASSERT(index <= 2);
213
214 if (index == 0)
215 return (ZFSCTL_INO_SNAPDIR);
216
217 return (zfsvfs->z_shares_dir);
218 }
219
220 /*
221 * Create the '.zfs' directory. This directory is cached as part of the VFS
222 * structure. This results in a hold on the vfs_t. The code in zfs_umount()
223 * therefore checks against a vfs_count of 2 instead of 1. This reference
224 * is removed when the ctldir is destroyed in the unmount.
225 */
226 void
227 zfsctl_create(zfsvfs_t *zfsvfs)
228 {
229 vnode_t *vp, *rvp;
230 zfsctl_node_t *zcp;
231 uint64_t crtime[2];
232
233 ASSERT(zfsvfs->z_ctldir == NULL);
234
235 vp = gfs_root_create(sizeof (zfsctl_node_t), zfsvfs->z_vfs,
236 zfsctl_ops_root, ZFSCTL_INO_ROOT, zfsctl_root_entries,
237 zfsctl_root_inode_cb, MAXNAMELEN, NULL, NULL);
238 zcp = vp->v_data;
239 zcp->zc_id = ZFSCTL_INO_ROOT;
240
241 VERIFY(VFS_ROOT(zfsvfs->z_vfs, &rvp) == 0);
242 VERIFY(0 == sa_lookup(VTOZ(rvp)->z_sa_hdl, SA_ZPL_CRTIME(zfsvfs),
243 &crtime, sizeof (crtime)));
244 ZFS_TIME_DECODE(&zcp->zc_cmtime, crtime);
245 VN_RELE(rvp);
246
247 /*
248 * We're only faking the fact that we have a root of a filesystem for
249 * the sake of the GFS interfaces. Undo the flag manipulation it did
250 * for us.
251 */
252 vp->v_flag &= ~(VROOT | VNOCACHE | VNOMAP | VNOSWAP | VNOMOUNT);
253
254 zfsvfs->z_ctldir = vp;
255 }
256
257 /*
258 * Destroy the '.zfs' directory. Only called when the filesystem is unmounted.
259 * There might still be more references if we were force unmounted, but only
260 * new zfs_inactive() calls can occur and they don't reference .zfs
261 */
262 void
263 zfsctl_destroy(zfsvfs_t *zfsvfs)
264 {
265 VN_RELE(zfsvfs->z_ctldir);
266 zfsvfs->z_ctldir = NULL;
267 }
268
269 /*
270 * Given a root znode, retrieve the associated .zfs directory.
271 * Add a hold to the vnode and return it.
272 */
273 vnode_t *
274 zfsctl_root(znode_t *zp)
275 {
276 ASSERT(zfs_has_ctldir(zp));
277 VN_HOLD(zp->z_zfsvfs->z_ctldir);
278 return (zp->z_zfsvfs->z_ctldir);
279 }
280
281 /*
282 * Common open routine. Disallow any write access.
283 */
284 /* ARGSUSED */
285 static int
286 zfsctl_common_open(vnode_t **vpp, int flags, cred_t *cr, caller_context_t *ct)
287 {
288 if (flags & FWRITE)
289 return (SET_ERROR(EACCES));
290
291 return (0);
292 }
293
294 /*
295 * Common close routine. Nothing to do here.
296 */
297 /* ARGSUSED */
298 static int
299 zfsctl_common_close(vnode_t *vpp, int flags, int count, offset_t off,
300 cred_t *cr, caller_context_t *ct)
301 {
302 return (0);
303 }
304
305 /*
306 * Common access routine. Disallow writes.
307 */
308 /* ARGSUSED */
309 static int
310 zfsctl_common_access(vnode_t *vp, int mode, int flags, cred_t *cr,
311 caller_context_t *ct)
312 {
313 if (flags & V_ACE_MASK) {
314 if (mode & ACE_ALL_WRITE_PERMS)
315 return (SET_ERROR(EACCES));
316 } else {
317 if (mode & VWRITE)
318 return (SET_ERROR(EACCES));
319 }
320
321 return (0);
322 }
323
324 /*
325 * Common getattr function. Fill in basic information.
326 */
327 static void
328 zfsctl_common_getattr(vnode_t *vp, vattr_t *vap)
329 {
330 timestruc_t now;
331
332 vap->va_uid = 0;
333 vap->va_gid = 0;
334 vap->va_rdev = 0;
335 /*
336 * We are a purely virtual object, so we have no
337 * blocksize or allocated blocks.
338 */
339 vap->va_blksize = 0;
340 vap->va_nblocks = 0;
341 vap->va_seq = 0;
342 vap->va_fsid = vp->v_vfsp->vfs_dev;
343 vap->va_mode = S_IRUSR | S_IXUSR | S_IRGRP | S_IXGRP |
344 S_IROTH | S_IXOTH;
345 vap->va_type = VDIR;
346 /*
347 * We live in the now (for atime).
348 */
349 gethrestime(&now);
350 vap->va_atime = now;
351 }
352
353 /*ARGSUSED*/
354 static int
355 zfsctl_common_fid(vnode_t *vp, fid_t *fidp, caller_context_t *ct)
356 {
357 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data;
358 zfsctl_node_t *zcp = vp->v_data;
359 uint64_t object = zcp->zc_id;
360 zfid_short_t *zfid;
361 int i;
362
363 ZFS_ENTER(zfsvfs);
364
365 if (fidp->fid_len < SHORT_FID_LEN) {
366 fidp->fid_len = SHORT_FID_LEN;
367 ZFS_EXIT(zfsvfs);
368 return (SET_ERROR(ENOSPC));
369 }
370
371 zfid = (zfid_short_t *)fidp;
372
373 zfid->zf_len = SHORT_FID_LEN;
374
375 for (i = 0; i < sizeof (zfid->zf_object); i++)
376 zfid->zf_object[i] = (uint8_t)(object >> (8 * i));
377
378 /* .zfs znodes always have a generation number of 0 */
379 for (i = 0; i < sizeof (zfid->zf_gen); i++)
380 zfid->zf_gen[i] = 0;
381
382 ZFS_EXIT(zfsvfs);
383 return (0);
384 }
385
386
387 /*ARGSUSED*/
388 static int
389 zfsctl_shares_fid(vnode_t *vp, fid_t *fidp, caller_context_t *ct)
390 {
391 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data;
392 znode_t *dzp;
393 int error;
394
395 ZFS_ENTER(zfsvfs);
396
397 if (zfsvfs->z_shares_dir == 0) {
398 ZFS_EXIT(zfsvfs);
399 return (SET_ERROR(ENOTSUP));
400 }
401
402 if ((error = zfs_zget(zfsvfs, zfsvfs->z_shares_dir, &dzp)) == 0) {
403 error = VOP_FID(ZTOV(dzp), fidp, ct);
404 VN_RELE(ZTOV(dzp));
405 }
406
407 ZFS_EXIT(zfsvfs);
408 return (error);
409 }
410 /*
411 * .zfs inode namespace
412 *
413 * We need to generate unique inode numbers for all files and directories
414 * within the .zfs pseudo-filesystem. We use the following scheme:
415 *
416 * ENTRY ZFSCTL_INODE
417 * .zfs 1
418 * .zfs/snapshot 2
419 * .zfs/snapshot/<snap> objectid(snap)
420 */
421
422 #define ZFSCTL_INO_SNAP(id) (id)
423
424 /*
425 * Get root directory attributes.
426 */
427 /* ARGSUSED */
428 static int
429 zfsctl_root_getattr(vnode_t *vp, vattr_t *vap, int flags, cred_t *cr,
430 caller_context_t *ct)
431 {
432 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data;
433 zfsctl_node_t *zcp = vp->v_data;
434
435 ZFS_ENTER(zfsvfs);
436 vap->va_nodeid = ZFSCTL_INO_ROOT;
437 vap->va_nlink = vap->va_size = NROOT_ENTRIES;
438 vap->va_mtime = vap->va_ctime = zcp->zc_cmtime;
439
440 zfsctl_common_getattr(vp, vap);
441 ZFS_EXIT(zfsvfs);
442
443 return (0);
444 }
445
446 /*
447 * Special case the handling of "..".
448 */
449 /* ARGSUSED */
450 int
451 zfsctl_root_lookup(vnode_t *dvp, char *nm, vnode_t **vpp, pathname_t *pnp,
452 int flags, vnode_t *rdir, cred_t *cr, caller_context_t *ct,
453 int *direntflags, pathname_t *realpnp)
454 {
455 zfsvfs_t *zfsvfs = dvp->v_vfsp->vfs_data;
456 int err;
457
458 /*
459 * No extended attributes allowed under .zfs
460 */
461 if (flags & LOOKUP_XATTR)
462 return (SET_ERROR(EINVAL));
463
464 ZFS_ENTER(zfsvfs);
465
466 if (strcmp(nm, "..") == 0) {
467 err = VFS_ROOT(dvp->v_vfsp, vpp);
468 } else {
469 err = gfs_vop_lookup(dvp, nm, vpp, pnp, flags, rdir,
470 cr, ct, direntflags, realpnp);
471 }
472
473 ZFS_EXIT(zfsvfs);
474
475 return (err);
476 }
477
478 static int
479 zfsctl_pathconf(vnode_t *vp, int cmd, ulong_t *valp, cred_t *cr,
480 caller_context_t *ct)
481 {
482 /*
483 * We only care about ACL_ENABLED so that libsec can
484 * display ACL correctly and not default to POSIX draft.
485 */
486 if (cmd == _PC_ACL_ENABLED) {
487 *valp = _ACL_ACE_ENABLED;
488 return (0);
489 }
490
491 return (fs_pathconf(vp, cmd, valp, cr, ct));
492 }
493
494 static const fs_operation_def_t zfsctl_tops_root[] = {
495 { VOPNAME_OPEN, { .vop_open = zfsctl_common_open } },
496 { VOPNAME_CLOSE, { .vop_close = zfsctl_common_close } },
497 { VOPNAME_IOCTL, { .error = fs_inval } },
498 { VOPNAME_GETATTR, { .vop_getattr = zfsctl_root_getattr } },
499 { VOPNAME_ACCESS, { .vop_access = zfsctl_common_access } },
500 { VOPNAME_READDIR, { .vop_readdir = gfs_vop_readdir } },
501 { VOPNAME_LOOKUP, { .vop_lookup = zfsctl_root_lookup } },
502 { VOPNAME_SEEK, { .vop_seek = fs_seek } },
503 { VOPNAME_INACTIVE, { .vop_inactive = gfs_vop_inactive } },
504 { VOPNAME_PATHCONF, { .vop_pathconf = zfsctl_pathconf } },
505 { VOPNAME_FID, { .vop_fid = zfsctl_common_fid } },
506 { NULL }
507 };
508
509 /*
510 * Gets the full dataset name that corresponds to the given snapshot name
511 * Example:
512 * zfsctl_snapshot_zname("snap1") -> "mypool/myfs@snap1"
513 */
514 static int
515 zfsctl_snapshot_zname(vnode_t *vp, const char *name, int len, char *zname)
516 {
517 objset_t *os = ((zfsvfs_t *)((vp)->v_vfsp->vfs_data))->z_os;
518
519 if (zfs_component_namecheck(name, NULL, NULL) != 0)
520 return (SET_ERROR(EILSEQ));
521 dmu_objset_name(os, zname);
522 if (strlen(zname) + 1 + strlen(name) >= len)
523 return (SET_ERROR(ENAMETOOLONG));
524 (void) strcat(zname, "@");
525 (void) strcat(zname, name);
526 return (0);
527 }
528
529 static int
530 zfsctl_unmount_snap(zfs_snapentry_t *sep, int fflags, cred_t *cr)
531 {
532 vnode_t *svp = sep->se_root;
533 int error;
534
535 ASSERT(vn_ismntpt(svp));
536
537 /* this will be dropped by dounmount() */
538 if ((error = vn_vfswlock(svp)) != 0)
539 return (error);
540
541 VN_HOLD(svp);
542 error = dounmount(vn_mountedvfs(svp), fflags, cr);
543 if (error) {
544 VN_RELE(svp);
545 return (error);
546 }
547
548 /*
549 * We can't use VN_RELE(), as that will try to invoke
550 * zfsctl_snapdir_inactive(), which would cause us to destroy
551 * the sd_lock mutex held by our caller.
552 */
553 ASSERT(svp->v_count == 1);
554 gfs_vop_inactive(svp, cr, NULL);
555
556 kmem_free(sep->se_name, strlen(sep->se_name) + 1);
557 kmem_free(sep, sizeof (zfs_snapentry_t));
558
559 return (0);
560 }
561
562 static void
563 zfsctl_rename_snap(zfsctl_snapdir_t *sdp, zfs_snapentry_t *sep, const char *nm)
564 {
565 avl_index_t where;
566 vfs_t *vfsp;
567 refstr_t *pathref;
568 char newpath[MAXNAMELEN];
569 char *tail;
570
571 ASSERT(MUTEX_HELD(&sdp->sd_lock));
572 ASSERT(sep != NULL);
573
574 vfsp = vn_mountedvfs(sep->se_root);
575 ASSERT(vfsp != NULL);
576
577 vfs_lock_wait(vfsp);
578
579 /*
580 * Change the name in the AVL tree.
581 */
582 avl_remove(&sdp->sd_snaps, sep);
583 kmem_free(sep->se_name, strlen(sep->se_name) + 1);
584 sep->se_name = kmem_alloc(strlen(nm) + 1, KM_SLEEP);
585 (void) strcpy(sep->se_name, nm);
586 VERIFY(avl_find(&sdp->sd_snaps, sep, &where) == NULL);
587 avl_insert(&sdp->sd_snaps, sep, where);
588
589 /*
590 * Change the current mountpoint info:
591 * - update the tail of the mntpoint path
592 * - update the tail of the resource path
593 */
594 pathref = vfs_getmntpoint(vfsp);
595 (void) strncpy(newpath, refstr_value(pathref), sizeof (newpath));
596 VERIFY((tail = strrchr(newpath, '/')) != NULL);
597 *(tail+1) = '\0';
598 ASSERT3U(strlen(newpath) + strlen(nm), <, sizeof (newpath));
599 (void) strcat(newpath, nm);
600 refstr_rele(pathref);
601 vfs_setmntpoint(vfsp, newpath, 0);
602
603 pathref = vfs_getresource(vfsp);
604 (void) strncpy(newpath, refstr_value(pathref), sizeof (newpath));
605 VERIFY((tail = strrchr(newpath, '@')) != NULL);
606 *(tail+1) = '\0';
607 ASSERT3U(strlen(newpath) + strlen(nm), <, sizeof (newpath));
608 (void) strcat(newpath, nm);
609 refstr_rele(pathref);
610 vfs_setresource(vfsp, newpath, 0);
611
612 vfs_unlock(vfsp);
613 }
614
615 /*ARGSUSED*/
616 static int
617 zfsctl_snapdir_rename(vnode_t *sdvp, char *snm, vnode_t *tdvp, char *tnm,
618 cred_t *cr, caller_context_t *ct, int flags)
619 {
620 zfsctl_snapdir_t *sdp = sdvp->v_data;
621 zfs_snapentry_t search, *sep;
622 zfsvfs_t *zfsvfs;
623 avl_index_t where;
624 char from[ZFS_MAX_DATASET_NAME_LEN], to[ZFS_MAX_DATASET_NAME_LEN];
625 char real[ZFS_MAX_DATASET_NAME_LEN], fsname[ZFS_MAX_DATASET_NAME_LEN];
626 int err;
627
628 zfsvfs = sdvp->v_vfsp->vfs_data;
629 ZFS_ENTER(zfsvfs);
630
631 if ((flags & FIGNORECASE) || zfsvfs->z_case == ZFS_CASE_INSENSITIVE) {
632 err = dmu_snapshot_realname(zfsvfs->z_os, snm, real,
633 sizeof (real), NULL);
634 if (err == 0) {
635 snm = real;
636 } else if (err != ENOTSUP) {
637 ZFS_EXIT(zfsvfs);
638 return (err);
639 }
640 }
641
642 ZFS_EXIT(zfsvfs);
643
644 dmu_objset_name(zfsvfs->z_os, fsname);
645
646 err = zfsctl_snapshot_zname(sdvp, snm, sizeof (from), from);
647 if (err == 0)
648 err = zfsctl_snapshot_zname(tdvp, tnm, sizeof (to), to);
649 if (err == 0)
650 err = zfs_secpolicy_rename_perms(from, to, cr);
651 if (err != 0)
652 return (err);
653
654 /*
655 * Cannot move snapshots out of the snapdir.
656 */
657 if (sdvp != tdvp)
658 return (SET_ERROR(EINVAL));
659
660 if (strcmp(snm, tnm) == 0)
661 return (0);
662
663 mutex_enter(&sdp->sd_lock);
664
665 search.se_name = (char *)snm;
666 if ((sep = avl_find(&sdp->sd_snaps, &search, &where)) == NULL) {
667 mutex_exit(&sdp->sd_lock);
668 return (SET_ERROR(ENOENT));
669 }
670
671 err = dsl_dataset_rename_snapshot(fsname, snm, tnm, B_FALSE);
672 if (err == 0)
673 zfsctl_rename_snap(sdp, sep, tnm);
674
675 mutex_exit(&sdp->sd_lock);
676
677 return (err);
678 }
679
680 /* ARGSUSED */
681 static int
682 zfsctl_snapdir_remove(vnode_t *dvp, char *name, vnode_t *cwd, cred_t *cr,
683 caller_context_t *ct, int flags)
684 {
685 zfsctl_snapdir_t *sdp = dvp->v_data;
686 zfs_snapentry_t *sep;
687 zfs_snapentry_t search;
688 zfsvfs_t *zfsvfs;
689 char snapname[ZFS_MAX_DATASET_NAME_LEN];
690 char real[ZFS_MAX_DATASET_NAME_LEN];
691 int err;
692
693 zfsvfs = dvp->v_vfsp->vfs_data;
694 ZFS_ENTER(zfsvfs);
695
696 if ((flags & FIGNORECASE) || zfsvfs->z_case == ZFS_CASE_INSENSITIVE) {
697
698 err = dmu_snapshot_realname(zfsvfs->z_os, name, real,
699 sizeof (real), NULL);
700 if (err == 0) {
701 name = real;
702 } else if (err != ENOTSUP) {
703 ZFS_EXIT(zfsvfs);
704 return (err);
705 }
706 }
707
708 ZFS_EXIT(zfsvfs);
709
710 err = zfsctl_snapshot_zname(dvp, name, sizeof (snapname), snapname);
711 if (err == 0)
712 err = zfs_secpolicy_destroy_perms(snapname, cr);
713 if (err != 0)
714 return (err);
715
716 mutex_enter(&sdp->sd_lock);
717
718 search.se_name = name;
719 sep = avl_find(&sdp->sd_snaps, &search, NULL);
720 if (sep) {
721 avl_remove(&sdp->sd_snaps, sep);
722 err = zfsctl_unmount_snap(sep, MS_FORCE, cr);
723 if (err != 0)
724 avl_add(&sdp->sd_snaps, sep);
725 else
726 err = dsl_destroy_snapshot(snapname, B_FALSE);
727 } else {
728 err = SET_ERROR(ENOENT);
729 }
730
731 mutex_exit(&sdp->sd_lock);
732
733 return (err);
734 }
735
736 /*
737 * This creates a snapshot under '.zfs/snapshot'.
738 */
739 /* ARGSUSED */
740 static int
741 zfsctl_snapdir_mkdir(vnode_t *dvp, char *dirname, vattr_t *vap, vnode_t **vpp,
742 cred_t *cr, caller_context_t *cc, int flags, vsecattr_t *vsecp)
743 {
744 zfsvfs_t *zfsvfs = dvp->v_vfsp->vfs_data;
745 char name[ZFS_MAX_DATASET_NAME_LEN];
746 int err;
747 static enum symfollow follow = NO_FOLLOW;
748 static enum uio_seg seg = UIO_SYSSPACE;
749
750 if (zfs_component_namecheck(dirname, NULL, NULL) != 0)
751 return (SET_ERROR(EILSEQ));
752
753 dmu_objset_name(zfsvfs->z_os, name);
754
755 *vpp = NULL;
756
757 err = zfs_secpolicy_snapshot_perms(name, cr);
758 if (err != 0)
759 return (err);
760
761 if (err == 0) {
762 err = dmu_objset_snapshot_one(name, dirname);
763 if (err != 0)
764 return (err);
765 err = lookupnameat(dirname, seg, follow, NULL, vpp, dvp);
766 }
767
768 return (err);
769 }
770
771 /*
772 * Lookup entry point for the 'snapshot' directory. Try to open the
773 * snapshot if it exist, creating the pseudo filesystem vnode as necessary.
774 * Perform a mount of the associated dataset on top of the vnode.
775 */
776 /* ARGSUSED */
777 static int
778 zfsctl_snapdir_lookup(vnode_t *dvp, char *nm, vnode_t **vpp, pathname_t *pnp,
779 int flags, vnode_t *rdir, cred_t *cr, caller_context_t *ct,
780 int *direntflags, pathname_t *realpnp)
781 {
782 zfsctl_snapdir_t *sdp = dvp->v_data;
783 objset_t *snap;
784 char snapname[ZFS_MAX_DATASET_NAME_LEN];
785 char real[ZFS_MAX_DATASET_NAME_LEN];
786 char *mountpoint;
787 zfs_snapentry_t *sep, search;
788 struct mounta margs;
789 vfs_t *vfsp;
790 size_t mountpoint_len;
791 avl_index_t where;
792 zfsvfs_t *zfsvfs = dvp->v_vfsp->vfs_data;
793 int err;
794
795 /*
796 * No extended attributes allowed under .zfs
797 */
798 if (flags & LOOKUP_XATTR)
799 return (SET_ERROR(EINVAL));
800
801 ASSERT(dvp->v_type == VDIR);
802
803 /*
804 * If we get a recursive call, that means we got called
805 * from the domount() code while it was trying to look up the
806 * spec (which looks like a local path for zfs). We need to
807 * add some flag to domount() to tell it not to do this lookup.
808 */
809 if (MUTEX_HELD(&sdp->sd_lock))
810 return (SET_ERROR(ENOENT));
811
812 ZFS_ENTER(zfsvfs);
813
814 if (gfs_lookup_dot(vpp, dvp, zfsvfs->z_ctldir, nm) == 0) {
815 ZFS_EXIT(zfsvfs);
816 return (0);
817 }
818
819 if (flags & FIGNORECASE) {
820 boolean_t conflict = B_FALSE;
821
822 err = dmu_snapshot_realname(zfsvfs->z_os, nm, real,
823 sizeof (real), &conflict);
824 if (err == 0) {
825 nm = real;
826 } else if (err != ENOTSUP) {
827 ZFS_EXIT(zfsvfs);
828 return (err);
829 }
830 if (realpnp)
831 (void) strlcpy(realpnp->pn_buf, nm,
832 realpnp->pn_bufsize);
833 if (conflict && direntflags)
834 *direntflags = ED_CASE_CONFLICT;
835 }
836
837 mutex_enter(&sdp->sd_lock);
838 search.se_name = (char *)nm;
839 if ((sep = avl_find(&sdp->sd_snaps, &search, &where)) != NULL) {
840 *vpp = sep->se_root;
841 VN_HOLD(*vpp);
842 err = traverse(vpp);
843 if (err != 0) {
844 VN_RELE(*vpp);
845 *vpp = NULL;
846 } else if (*vpp == sep->se_root) {
847 /*
848 * The snapshot was unmounted behind our backs,
849 * try to remount it.
850 */
851 goto domount;
852 } else {
853 /*
854 * VROOT was set during the traverse call. We need
855 * to clear it since we're pretending to be part
856 * of our parent's vfs.
857 */
858 (*vpp)->v_flag &= ~VROOT;
859 }
860 mutex_exit(&sdp->sd_lock);
861 ZFS_EXIT(zfsvfs);
862 return (err);
863 }
864
865 /*
866 * The requested snapshot is not currently mounted, look it up.
867 */
868 err = zfsctl_snapshot_zname(dvp, nm, sizeof (snapname), snapname);
869 if (err != 0) {
870 mutex_exit(&sdp->sd_lock);
871 ZFS_EXIT(zfsvfs);
872 /*
873 * handle "ls *" or "?" in a graceful manner,
874 * forcing EILSEQ to ENOENT.
875 * Since shell ultimately passes "*" or "?" as name to lookup
876 */
877 return (err == EILSEQ ? ENOENT : err);
878 }
879 if (dmu_objset_hold(snapname, FTAG, &snap) != 0) {
880 mutex_exit(&sdp->sd_lock);
881 ZFS_EXIT(zfsvfs);
882 return (SET_ERROR(ENOENT));
883 }
884
885 sep = kmem_alloc(sizeof (zfs_snapentry_t), KM_SLEEP);
886 sep->se_name = kmem_alloc(strlen(nm) + 1, KM_SLEEP);
887 (void) strcpy(sep->se_name, nm);
888 *vpp = sep->se_root = zfsctl_snapshot_mknode(dvp, dmu_objset_id(snap));
889 avl_insert(&sdp->sd_snaps, sep, where);
890
891 dmu_objset_rele(snap, FTAG);
892 domount:
893 mountpoint_len = strlen(refstr_value(dvp->v_vfsp->vfs_mntpt)) +
894 strlen("/.zfs/snapshot/") + strlen(nm) + 1;
895 mountpoint = kmem_alloc(mountpoint_len, KM_SLEEP);
896 (void) snprintf(mountpoint, mountpoint_len, "%s/.zfs/snapshot/%s",
897 refstr_value(dvp->v_vfsp->vfs_mntpt), nm);
898
899 margs.spec = snapname;
900 margs.dir = mountpoint;
901 margs.flags = MS_SYSSPACE | MS_NOMNTTAB;
902 margs.fstype = "zfs";
903 margs.dataptr = NULL;
904 margs.datalen = 0;
905 margs.optptr = NULL;
906 margs.optlen = 0;
907
908 err = domount("zfs", &margs, *vpp, kcred, &vfsp);
909 kmem_free(mountpoint, mountpoint_len);
910
911 if (err == 0) {
912 /*
913 * Return the mounted root rather than the covered mount point.
914 * Takes the GFS vnode at .zfs/snapshot/<snapname> and returns
915 * the ZFS vnode mounted on top of the GFS node. This ZFS
916 * vnode is the root of the newly created vfsp.
917 */
918 VFS_RELE(vfsp);
919 err = traverse(vpp);
920 }
921
922 if (err == 0) {
923 /*
924 * Fix up the root vnode mounted on .zfs/snapshot/<snapname>.
925 *
926 * This is where we lie about our v_vfsp in order to
927 * make .zfs/snapshot/<snapname> accessible over NFS
928 * without requiring manual mounts of <snapname>.
929 */
930 ASSERT(VTOZ(*vpp)->z_zfsvfs != zfsvfs);
931 VTOZ(*vpp)->z_zfsvfs->z_parent = zfsvfs;
932 (*vpp)->v_vfsp = zfsvfs->z_vfs;
933 (*vpp)->v_flag &= ~VROOT;
934 }
935 mutex_exit(&sdp->sd_lock);
936 ZFS_EXIT(zfsvfs);
937
938 /*
939 * If we had an error, drop our hold on the vnode and
940 * zfsctl_snapshot_inactive() will clean up.
941 */
942 if (err != 0) {
943 VN_RELE(*vpp);
944 *vpp = NULL;
945 }
946 return (err);
947 }
948
949 /* ARGSUSED */
950 static int
951 zfsctl_shares_lookup(vnode_t *dvp, char *nm, vnode_t **vpp, pathname_t *pnp,
952 int flags, vnode_t *rdir, cred_t *cr, caller_context_t *ct,
953 int *direntflags, pathname_t *realpnp)
954 {
955 zfsvfs_t *zfsvfs = dvp->v_vfsp->vfs_data;
956 znode_t *dzp;
957 int error;
958
959 ZFS_ENTER(zfsvfs);
960
961 if (gfs_lookup_dot(vpp, dvp, zfsvfs->z_ctldir, nm) == 0) {
962 ZFS_EXIT(zfsvfs);
963 return (0);
964 }
965
966 if (zfsvfs->z_shares_dir == 0) {
967 ZFS_EXIT(zfsvfs);
968 return (SET_ERROR(ENOTSUP));
969 }
970 if ((error = zfs_zget(zfsvfs, zfsvfs->z_shares_dir, &dzp)) == 0) {
971 error = VOP_LOOKUP(ZTOV(dzp), nm, vpp, pnp,
972 flags, rdir, cr, ct, direntflags, realpnp);
973 VN_RELE(ZTOV(dzp));
974 }
975
976 ZFS_EXIT(zfsvfs);
977
978 return (error);
979 }
980
981 /* ARGSUSED */
982 static int
983 zfsctl_snapdir_readdir_cb(vnode_t *vp, void *dp, int *eofp,
984 offset_t *offp, offset_t *nextp, void *data, int flags)
985 {
986 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data;
987 char snapname[ZFS_MAX_DATASET_NAME_LEN];
988 uint64_t id, cookie;
989 boolean_t case_conflict;
990 int error;
991
992 ZFS_ENTER(zfsvfs);
993
994 cookie = *offp;
995 dsl_pool_config_enter(dmu_objset_pool(zfsvfs->z_os), FTAG);
996 error = dmu_snapshot_list_next(zfsvfs->z_os,
997 sizeof (snapname), snapname, &id, &cookie, &case_conflict);
998 dsl_pool_config_exit(dmu_objset_pool(zfsvfs->z_os), FTAG);
999 if (error) {
1000 ZFS_EXIT(zfsvfs);
1001 if (error == ENOENT) {
1002 *eofp = 1;
1003 return (0);
1004 }
1005 return (error);
1006 }
1007
1008 if (flags & V_RDDIR_ENTFLAGS) {
1009 edirent_t *eodp = dp;
1010
1011 (void) strcpy(eodp->ed_name, snapname);
1012 eodp->ed_ino = ZFSCTL_INO_SNAP(id);
1013 eodp->ed_eflags = case_conflict ? ED_CASE_CONFLICT : 0;
1014 } else {
1015 struct dirent64 *odp = dp;
1016
1017 (void) strcpy(odp->d_name, snapname);
1018 odp->d_ino = ZFSCTL_INO_SNAP(id);
1019 }
1020 *nextp = cookie;
1021
1022 ZFS_EXIT(zfsvfs);
1023
1024 return (0);
1025 }
1026
1027 /* ARGSUSED */
1028 static int
1029 zfsctl_shares_readdir(vnode_t *vp, uio_t *uiop, cred_t *cr, int *eofp,
1030 caller_context_t *ct, int flags)
1031 {
1032 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data;
1033 znode_t *dzp;
1034 int error;
1035
1036 ZFS_ENTER(zfsvfs);
1037
1038 if (zfsvfs->z_shares_dir == 0) {
1039 ZFS_EXIT(zfsvfs);
1040 return (SET_ERROR(ENOTSUP));
1041 }
1042 if ((error = zfs_zget(zfsvfs, zfsvfs->z_shares_dir, &dzp)) == 0) {
1043 error = VOP_READDIR(ZTOV(dzp), uiop, cr, eofp, ct, flags);
1044 VN_RELE(ZTOV(dzp));
1045 } else {
1046 *eofp = 1;
1047 error = SET_ERROR(ENOENT);
1048 }
1049
1050 ZFS_EXIT(zfsvfs);
1051 return (error);
1052 }
1053
1054 /*
1055 * pvp is the '.zfs' directory (zfsctl_node_t).
1056 *
1057 * Creates vp, which is '.zfs/snapshot' (zfsctl_snapdir_t).
1058 *
1059 * This function is the callback to create a GFS vnode for '.zfs/snapshot'
1060 * when a lookup is performed on .zfs for "snapshot".
1061 */
1062 vnode_t *
1063 zfsctl_mknode_snapdir(vnode_t *pvp)
1064 {
1065 vnode_t *vp;
1066 zfsctl_snapdir_t *sdp;
1067
1068 vp = gfs_dir_create(sizeof (zfsctl_snapdir_t), pvp,
1069 zfsctl_ops_snapdir, NULL, NULL, MAXNAMELEN,
1070 zfsctl_snapdir_readdir_cb, NULL);
1071 sdp = vp->v_data;
1072 sdp->sd_node.zc_id = ZFSCTL_INO_SNAPDIR;
1073 sdp->sd_node.zc_cmtime = ((zfsctl_node_t *)pvp->v_data)->zc_cmtime;
1074 mutex_init(&sdp->sd_lock, NULL, MUTEX_DEFAULT, NULL);
1075 avl_create(&sdp->sd_snaps, snapentry_compare,
1076 sizeof (zfs_snapentry_t), offsetof(zfs_snapentry_t, se_node));
1077 return (vp);
1078 }
1079
1080 vnode_t *
1081 zfsctl_mknode_shares(vnode_t *pvp)
1082 {
1083 vnode_t *vp;
1084 zfsctl_node_t *sdp;
1085
1086 vp = gfs_dir_create(sizeof (zfsctl_node_t), pvp,
1087 zfsctl_ops_shares, NULL, NULL, MAXNAMELEN,
1088 NULL, NULL);
1089 sdp = vp->v_data;
1090 sdp->zc_cmtime = ((zfsctl_node_t *)pvp->v_data)->zc_cmtime;
1091 return (vp);
1092
1093 }
1094
1095 /* ARGSUSED */
1096 static int
1097 zfsctl_shares_getattr(vnode_t *vp, vattr_t *vap, int flags, cred_t *cr,
1098 caller_context_t *ct)
1099 {
1100 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data;
1101 znode_t *dzp;
1102 int error;
1103
1104 ZFS_ENTER(zfsvfs);
1105 if (zfsvfs->z_shares_dir == 0) {
1106 ZFS_EXIT(zfsvfs);
1107 return (SET_ERROR(ENOTSUP));
1108 }
1109 if ((error = zfs_zget(zfsvfs, zfsvfs->z_shares_dir, &dzp)) == 0) {
1110 error = VOP_GETATTR(ZTOV(dzp), vap, flags, cr, ct);
1111 VN_RELE(ZTOV(dzp));
1112 }
1113 ZFS_EXIT(zfsvfs);
1114 return (error);
1115
1116
1117 }
1118
1119 /* ARGSUSED */
1120 static int
1121 zfsctl_snapdir_getattr(vnode_t *vp, vattr_t *vap, int flags, cred_t *cr,
1122 caller_context_t *ct)
1123 {
1124 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data;
1125 zfsctl_snapdir_t *sdp = vp->v_data;
1126
1127 ZFS_ENTER(zfsvfs);
1128 zfsctl_common_getattr(vp, vap);
1129 vap->va_nodeid = gfs_file_inode(vp);
1130 vap->va_nlink = vap->va_size = avl_numnodes(&sdp->sd_snaps) + 2;
1131 vap->va_ctime = vap->va_mtime = dmu_objset_snap_cmtime(zfsvfs->z_os);
1132 ZFS_EXIT(zfsvfs);
1133
1134 return (0);
1135 }
1136
1137 /* ARGSUSED */
1138 static void
1139 zfsctl_snapdir_inactive(vnode_t *vp, cred_t *cr, caller_context_t *ct)
1140 {
1141 zfsctl_snapdir_t *sdp = vp->v_data;
1142 void *private;
1143
1144 private = gfs_dir_inactive(vp);
1145 if (private != NULL) {
1146 ASSERT(avl_numnodes(&sdp->sd_snaps) == 0);
1147 mutex_destroy(&sdp->sd_lock);
1148 avl_destroy(&sdp->sd_snaps);
1149 kmem_free(private, sizeof (zfsctl_snapdir_t));
1150 }
1151 }
1152
1153 static const fs_operation_def_t zfsctl_tops_snapdir[] = {
1154 { VOPNAME_OPEN, { .vop_open = zfsctl_common_open } },
1155 { VOPNAME_CLOSE, { .vop_close = zfsctl_common_close } },
1156 { VOPNAME_IOCTL, { .error = fs_inval } },
1157 { VOPNAME_GETATTR, { .vop_getattr = zfsctl_snapdir_getattr } },
1158 { VOPNAME_ACCESS, { .vop_access = zfsctl_common_access } },
1159 { VOPNAME_RENAME, { .vop_rename = zfsctl_snapdir_rename } },
1160 { VOPNAME_RMDIR, { .vop_rmdir = zfsctl_snapdir_remove } },
1161 { VOPNAME_MKDIR, { .vop_mkdir = zfsctl_snapdir_mkdir } },
1162 { VOPNAME_READDIR, { .vop_readdir = gfs_vop_readdir } },
1163 { VOPNAME_LOOKUP, { .vop_lookup = zfsctl_snapdir_lookup } },
1164 { VOPNAME_SEEK, { .vop_seek = fs_seek } },
1165 { VOPNAME_INACTIVE, { .vop_inactive = zfsctl_snapdir_inactive } },
1166 { VOPNAME_FID, { .vop_fid = zfsctl_common_fid } },
1167 { NULL }
1168 };
1169
1170 static const fs_operation_def_t zfsctl_tops_shares[] = {
1171 { VOPNAME_OPEN, { .vop_open = zfsctl_common_open } },
1172 { VOPNAME_CLOSE, { .vop_close = zfsctl_common_close } },
1173 { VOPNAME_IOCTL, { .error = fs_inval } },
1174 { VOPNAME_GETATTR, { .vop_getattr = zfsctl_shares_getattr } },
1175 { VOPNAME_ACCESS, { .vop_access = zfsctl_common_access } },
1176 { VOPNAME_READDIR, { .vop_readdir = zfsctl_shares_readdir } },
1177 { VOPNAME_LOOKUP, { .vop_lookup = zfsctl_shares_lookup } },
1178 { VOPNAME_SEEK, { .vop_seek = fs_seek } },
1179 { VOPNAME_INACTIVE, { .vop_inactive = gfs_vop_inactive } },
1180 { VOPNAME_FID, { .vop_fid = zfsctl_shares_fid } },
1181 { NULL }
1182 };
1183
1184 /*
1185 * pvp is the GFS vnode '.zfs/snapshot'.
1186 *
1187 * This creates a GFS node under '.zfs/snapshot' representing each
1188 * snapshot. This newly created GFS node is what we mount snapshot
1189 * vfs_t's ontop of.
1190 */
1191 static vnode_t *
1192 zfsctl_snapshot_mknode(vnode_t *pvp, uint64_t objset)
1193 {
1194 vnode_t *vp;
1195 zfsctl_node_t *zcp;
1196
1197 vp = gfs_dir_create(sizeof (zfsctl_node_t), pvp,
1198 zfsctl_ops_snapshot, NULL, NULL, MAXNAMELEN, NULL, NULL);
1199 zcp = vp->v_data;
1200 zcp->zc_id = objset;
1201
1202 return (vp);
1203 }
1204
1205 static void
1206 zfsctl_snapshot_inactive(vnode_t *vp, cred_t *cr, caller_context_t *ct)
1207 {
1208 zfsctl_snapdir_t *sdp;
1209 zfs_snapentry_t *sep, *next;
1210 vnode_t *dvp;
1211
1212 VERIFY(gfs_dir_lookup(vp, "..", &dvp, cr, 0, NULL, NULL) == 0);
1213 sdp = dvp->v_data;
1214
1215 mutex_enter(&sdp->sd_lock);
1216
1217 mutex_enter(&vp->v_lock);
1218 if (vp->v_count > 1) {
1219 vp->v_count--;
1220 mutex_exit(&vp->v_lock);
1221 mutex_exit(&sdp->sd_lock);
1222 VN_RELE(dvp);
1223 return;
1224 }
1225 mutex_exit(&vp->v_lock);
1226 ASSERT(!vn_ismntpt(vp));
1227
1228 sep = avl_first(&sdp->sd_snaps);
1229 while (sep != NULL) {
1230 next = AVL_NEXT(&sdp->sd_snaps, sep);
1231
1232 if (sep->se_root == vp) {
1233 avl_remove(&sdp->sd_snaps, sep);
1234 kmem_free(sep->se_name, strlen(sep->se_name) + 1);
1235 kmem_free(sep, sizeof (zfs_snapentry_t));
1236 break;
1237 }
1238 sep = next;
1239 }
1240 ASSERT(sep != NULL);
1241
1242 mutex_exit(&sdp->sd_lock);
1243 VN_RELE(dvp);
1244
1245 /*
1246 * Dispose of the vnode for the snapshot mount point.
1247 * This is safe to do because once this entry has been removed
1248 * from the AVL tree, it can't be found again, so cannot become
1249 * "active". If we lookup the same name again we will end up
1250 * creating a new vnode.
1251 */
1252 gfs_vop_inactive(vp, cr, ct);
1253 }
1254
1255
1256 /*
1257 * These VP's should never see the light of day. They should always
1258 * be covered.
1259 */
1260 static const fs_operation_def_t zfsctl_tops_snapshot[] = {
1261 VOPNAME_INACTIVE, { .vop_inactive = zfsctl_snapshot_inactive },
1262 NULL, NULL
1263 };
1264
1265 int
1266 zfsctl_lookup_objset(vfs_t *vfsp, uint64_t objsetid, zfsvfs_t **zfsvfsp)
1267 {
1268 zfsvfs_t *zfsvfs = vfsp->vfs_data;
1269 vnode_t *dvp, *vp;
1270 zfsctl_snapdir_t *sdp;
1271 zfsctl_node_t *zcp;
1272 zfs_snapentry_t *sep;
1273 int error;
1274
1275 ASSERT(zfsvfs->z_ctldir != NULL);
1276 error = zfsctl_root_lookup(zfsvfs->z_ctldir, "snapshot", &dvp,
1277 NULL, 0, NULL, kcred, NULL, NULL, NULL);
1278 if (error != 0)
1279 return (error);
1280 sdp = dvp->v_data;
1281
1282 mutex_enter(&sdp->sd_lock);
1283 sep = avl_first(&sdp->sd_snaps);
1284 while (sep != NULL) {
1285 vp = sep->se_root;
1286 zcp = vp->v_data;
1287 if (zcp->zc_id == objsetid)
1288 break;
1289
1290 sep = AVL_NEXT(&sdp->sd_snaps, sep);
1291 }
1292
1293 if (sep != NULL) {
1294 VN_HOLD(vp);
1295 /*
1296 * Return the mounted root rather than the covered mount point.
1297 * Takes the GFS vnode at .zfs/snapshot/<snapshot objsetid>
1298 * and returns the ZFS vnode mounted on top of the GFS node.
1299 * This ZFS vnode is the root of the vfs for objset 'objsetid'.
1300 */
1301 error = traverse(&vp);
1302 if (error == 0) {
1303 if (vp == sep->se_root)
1304 error = SET_ERROR(EINVAL);
1305 else
1306 *zfsvfsp = VTOZ(vp)->z_zfsvfs;
1307 }
1308 mutex_exit(&sdp->sd_lock);
1309 VN_RELE(vp);
1310 } else {
1311 error = SET_ERROR(EINVAL);
1312 mutex_exit(&sdp->sd_lock);
1313 }
1314
1315 VN_RELE(dvp);
1316
1317 return (error);
1318 }
1319
1320 /*
1321 * Unmount any snapshots for the given filesystem. This is called from
1322 * zfs_umount() - if we have a ctldir, then go through and unmount all the
1323 * snapshots.
1324 */
1325 int
1326 zfsctl_umount_snapshots(vfs_t *vfsp, int fflags, cred_t *cr)
1327 {
1328 zfsvfs_t *zfsvfs = vfsp->vfs_data;
1329 vnode_t *dvp;
1330 zfsctl_snapdir_t *sdp;
1331 zfs_snapentry_t *sep, *next;
1332 int error;
1333
1334 ASSERT(zfsvfs->z_ctldir != NULL);
1335 error = zfsctl_root_lookup(zfsvfs->z_ctldir, "snapshot", &dvp,
1336 NULL, 0, NULL, cr, NULL, NULL, NULL);
1337 if (error != 0)
1338 return (error);
1339 sdp = dvp->v_data;
1340
1341 mutex_enter(&sdp->sd_lock);
1342
1343 sep = avl_first(&sdp->sd_snaps);
1344 while (sep != NULL) {
1345 next = AVL_NEXT(&sdp->sd_snaps, sep);
1346
1347 /*
1348 * If this snapshot is not mounted, then it must
1349 * have just been unmounted by somebody else, and
1350 * will be cleaned up by zfsctl_snapdir_inactive().
1351 */
1352 if (vn_ismntpt(sep->se_root)) {
1353 avl_remove(&sdp->sd_snaps, sep);
1354 error = zfsctl_unmount_snap(sep, fflags, cr);
1355 if (error) {
1356 avl_add(&sdp->sd_snaps, sep);
1357 break;
1358 }
1359 }
1360 sep = next;
1361 }
1362
1363 mutex_exit(&sdp->sd_lock);
1364 VN_RELE(dvp);
1365
1366 return (error);
1367 }