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 https://opensource.org/licenses/CDDL-1.0.
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, 2018 by Delphix. All rights reserved.
24 */
25
26 /* Portions Copyright 2010 Robert Milkowski */
27
28 #include <sys/types.h>
29 #include <sys/param.h>
30 #include <sys/sysmacros.h>
31 #include <sys/kmem.h>
32 #include <sys/pathname.h>
33 #include <sys/vnode.h>
34 #include <sys/vfs.h>
35 #include <sys/mntent.h>
36 #include <sys/cmn_err.h>
37 #include <sys/zfs_znode.h>
38 #include <sys/zfs_vnops.h>
39 #include <sys/zfs_dir.h>
40 #include <sys/zil.h>
41 #include <sys/fs/zfs.h>
42 #include <sys/dmu.h>
43 #include <sys/dsl_prop.h>
44 #include <sys/dsl_dataset.h>
45 #include <sys/dsl_deleg.h>
46 #include <sys/spa.h>
47 #include <sys/zap.h>
48 #include <sys/sa.h>
49 #include <sys/sa_impl.h>
50 #include <sys/policy.h>
51 #include <sys/atomic.h>
52 #include <sys/zfs_ioctl.h>
53 #include <sys/zfs_ctldir.h>
54 #include <sys/zfs_fuid.h>
55 #include <sys/zfs_quota.h>
56 #include <sys/sunddi.h>
57 #include <sys/dmu_objset.h>
58 #include <sys/dsl_dir.h>
59 #include <sys/objlist.h>
60 #include <sys/zfeature.h>
61 #include <sys/zpl.h>
62 #include <linux/vfs_compat.h>
63 #include <linux/fs.h>
64 #include "zfs_comutil.h"
65
66 enum {
67 TOKEN_RO,
68 TOKEN_RW,
69 TOKEN_SETUID,
70 TOKEN_NOSETUID,
71 TOKEN_EXEC,
72 TOKEN_NOEXEC,
73 TOKEN_DEVICES,
74 TOKEN_NODEVICES,
75 TOKEN_DIRXATTR,
76 TOKEN_SAXATTR,
77 TOKEN_XATTR,
78 TOKEN_NOXATTR,
79 TOKEN_ATIME,
80 TOKEN_NOATIME,
81 TOKEN_RELATIME,
82 TOKEN_NORELATIME,
83 TOKEN_NBMAND,
84 TOKEN_NONBMAND,
85 TOKEN_MNTPOINT,
86 TOKEN_LAST,
87 };
88
89 static const match_table_t zpl_tokens = {
90 { TOKEN_RO, MNTOPT_RO },
91 { TOKEN_RW, MNTOPT_RW },
92 { TOKEN_SETUID, MNTOPT_SETUID },
93 { TOKEN_NOSETUID, MNTOPT_NOSETUID },
94 { TOKEN_EXEC, MNTOPT_EXEC },
95 { TOKEN_NOEXEC, MNTOPT_NOEXEC },
96 { TOKEN_DEVICES, MNTOPT_DEVICES },
97 { TOKEN_NODEVICES, MNTOPT_NODEVICES },
98 { TOKEN_DIRXATTR, MNTOPT_DIRXATTR },
99 { TOKEN_SAXATTR, MNTOPT_SAXATTR },
100 { TOKEN_XATTR, MNTOPT_XATTR },
101 { TOKEN_NOXATTR, MNTOPT_NOXATTR },
102 { TOKEN_ATIME, MNTOPT_ATIME },
103 { TOKEN_NOATIME, MNTOPT_NOATIME },
104 { TOKEN_RELATIME, MNTOPT_RELATIME },
105 { TOKEN_NORELATIME, MNTOPT_NORELATIME },
106 { TOKEN_NBMAND, MNTOPT_NBMAND },
107 { TOKEN_NONBMAND, MNTOPT_NONBMAND },
108 { TOKEN_MNTPOINT, MNTOPT_MNTPOINT "=%s" },
109 { TOKEN_LAST, NULL },
110 };
111
112 static void
zfsvfs_vfs_free(vfs_t * vfsp)113 zfsvfs_vfs_free(vfs_t *vfsp)
114 {
115 if (vfsp != NULL) {
116 if (vfsp->vfs_mntpoint != NULL)
117 kmem_strfree(vfsp->vfs_mntpoint);
118 mutex_destroy(&vfsp->vfs_mntpt_lock);
119 kmem_free(vfsp, sizeof (vfs_t));
120 }
121 }
122
123 static int
zfsvfs_parse_option(char * option,int token,substring_t * args,vfs_t * vfsp)124 zfsvfs_parse_option(char *option, int token, substring_t *args, vfs_t *vfsp)
125 {
126 switch (token) {
127 case TOKEN_RO:
128 vfsp->vfs_readonly = B_TRUE;
129 vfsp->vfs_do_readonly = B_TRUE;
130 break;
131 case TOKEN_RW:
132 vfsp->vfs_readonly = B_FALSE;
133 vfsp->vfs_do_readonly = B_TRUE;
134 break;
135 case TOKEN_SETUID:
136 vfsp->vfs_setuid = B_TRUE;
137 vfsp->vfs_do_setuid = B_TRUE;
138 break;
139 case TOKEN_NOSETUID:
140 vfsp->vfs_setuid = B_FALSE;
141 vfsp->vfs_do_setuid = B_TRUE;
142 break;
143 case TOKEN_EXEC:
144 vfsp->vfs_exec = B_TRUE;
145 vfsp->vfs_do_exec = B_TRUE;
146 break;
147 case TOKEN_NOEXEC:
148 vfsp->vfs_exec = B_FALSE;
149 vfsp->vfs_do_exec = B_TRUE;
150 break;
151 case TOKEN_DEVICES:
152 vfsp->vfs_devices = B_TRUE;
153 vfsp->vfs_do_devices = B_TRUE;
154 break;
155 case TOKEN_NODEVICES:
156 vfsp->vfs_devices = B_FALSE;
157 vfsp->vfs_do_devices = B_TRUE;
158 break;
159 case TOKEN_DIRXATTR:
160 vfsp->vfs_xattr = ZFS_XATTR_DIR;
161 vfsp->vfs_do_xattr = B_TRUE;
162 break;
163 case TOKEN_SAXATTR:
164 vfsp->vfs_xattr = ZFS_XATTR_SA;
165 vfsp->vfs_do_xattr = B_TRUE;
166 break;
167 case TOKEN_XATTR:
168 vfsp->vfs_xattr = ZFS_XATTR_SA;
169 vfsp->vfs_do_xattr = B_TRUE;
170 break;
171 case TOKEN_NOXATTR:
172 vfsp->vfs_xattr = ZFS_XATTR_OFF;
173 vfsp->vfs_do_xattr = B_TRUE;
174 break;
175 case TOKEN_ATIME:
176 vfsp->vfs_atime = B_TRUE;
177 vfsp->vfs_do_atime = B_TRUE;
178 break;
179 case TOKEN_NOATIME:
180 vfsp->vfs_atime = B_FALSE;
181 vfsp->vfs_do_atime = B_TRUE;
182 break;
183 case TOKEN_RELATIME:
184 vfsp->vfs_relatime = B_TRUE;
185 vfsp->vfs_do_relatime = B_TRUE;
186 break;
187 case TOKEN_NORELATIME:
188 vfsp->vfs_relatime = B_FALSE;
189 vfsp->vfs_do_relatime = B_TRUE;
190 break;
191 case TOKEN_NBMAND:
192 vfsp->vfs_nbmand = B_TRUE;
193 vfsp->vfs_do_nbmand = B_TRUE;
194 break;
195 case TOKEN_NONBMAND:
196 vfsp->vfs_nbmand = B_FALSE;
197 vfsp->vfs_do_nbmand = B_TRUE;
198 break;
199 case TOKEN_MNTPOINT:
200 if (vfsp->vfs_mntpoint != NULL)
201 kmem_strfree(vfsp->vfs_mntpoint);
202 vfsp->vfs_mntpoint = match_strdup(&args[0]);
203 if (vfsp->vfs_mntpoint == NULL)
204 return (SET_ERROR(ENOMEM));
205 break;
206 default:
207 break;
208 }
209
210 return (0);
211 }
212
213 /*
214 * Parse the raw mntopts and return a vfs_t describing the options.
215 */
216 static int
zfsvfs_parse_options(char * mntopts,vfs_t ** vfsp)217 zfsvfs_parse_options(char *mntopts, vfs_t **vfsp)
218 {
219 vfs_t *tmp_vfsp;
220 int error;
221
222 tmp_vfsp = kmem_zalloc(sizeof (vfs_t), KM_SLEEP);
223 mutex_init(&tmp_vfsp->vfs_mntpt_lock, NULL, MUTEX_DEFAULT, NULL);
224
225 if (mntopts != NULL) {
226 substring_t args[MAX_OPT_ARGS];
227 char *tmp_mntopts, *p, *t;
228 int token;
229
230 tmp_mntopts = t = kmem_strdup(mntopts);
231 if (tmp_mntopts == NULL)
232 return (SET_ERROR(ENOMEM));
233
234 while ((p = strsep(&t, ",")) != NULL) {
235 if (!*p)
236 continue;
237
238 args[0].to = args[0].from = NULL;
239 token = match_token(p, zpl_tokens, args);
240 error = zfsvfs_parse_option(p, token, args, tmp_vfsp);
241 if (error) {
242 kmem_strfree(tmp_mntopts);
243 zfsvfs_vfs_free(tmp_vfsp);
244 return (error);
245 }
246 }
247
248 kmem_strfree(tmp_mntopts);
249 }
250
251 *vfsp = tmp_vfsp;
252
253 return (0);
254 }
255
256 boolean_t
zfs_is_readonly(zfsvfs_t * zfsvfs)257 zfs_is_readonly(zfsvfs_t *zfsvfs)
258 {
259 return (!!(zfsvfs->z_sb->s_flags & SB_RDONLY));
260 }
261
262 int
zfs_sync(struct super_block * sb,int wait,cred_t * cr)263 zfs_sync(struct super_block *sb, int wait, cred_t *cr)
264 {
265 (void) cr;
266 zfsvfs_t *zfsvfs = sb->s_fs_info;
267
268 /*
269 * Semantically, the only requirement is that the sync be initiated.
270 * The DMU syncs out txgs frequently, so there's nothing to do.
271 */
272 if (!wait)
273 return (0);
274
275 if (zfsvfs != NULL) {
276 /*
277 * Sync a specific filesystem.
278 */
279 dsl_pool_t *dp;
280 int error;
281
282 if ((error = zfs_enter(zfsvfs, FTAG)) != 0)
283 return (error);
284 dp = dmu_objset_pool(zfsvfs->z_os);
285
286 /*
287 * If the system is shutting down, then skip any
288 * filesystems which may exist on a suspended pool.
289 */
290 if (spa_suspended(dp->dp_spa)) {
291 zfs_exit(zfsvfs, FTAG);
292 return (0);
293 }
294
295 if (zfsvfs->z_log != NULL)
296 zil_commit(zfsvfs->z_log, 0);
297
298 zfs_exit(zfsvfs, FTAG);
299 } else {
300 /*
301 * Sync all ZFS filesystems. This is what happens when you
302 * run sync(1). Unlike other filesystems, ZFS honors the
303 * request by waiting for all pools to commit all dirty data.
304 */
305 spa_sync_allpools();
306 }
307
308 return (0);
309 }
310
311 static void
atime_changed_cb(void * arg,uint64_t newval)312 atime_changed_cb(void *arg, uint64_t newval)
313 {
314 zfsvfs_t *zfsvfs = arg;
315 struct super_block *sb = zfsvfs->z_sb;
316
317 if (sb == NULL)
318 return;
319 /*
320 * Update SB_NOATIME bit in VFS super block. Since atime update is
321 * determined by atime_needs_update(), atime_needs_update() needs to
322 * return false if atime is turned off, and not unconditionally return
323 * false if atime is turned on.
324 */
325 if (newval)
326 sb->s_flags &= ~SB_NOATIME;
327 else
328 sb->s_flags |= SB_NOATIME;
329 }
330
331 static void
relatime_changed_cb(void * arg,uint64_t newval)332 relatime_changed_cb(void *arg, uint64_t newval)
333 {
334 ((zfsvfs_t *)arg)->z_relatime = newval;
335 }
336
337 static void
xattr_changed_cb(void * arg,uint64_t newval)338 xattr_changed_cb(void *arg, uint64_t newval)
339 {
340 zfsvfs_t *zfsvfs = arg;
341
342 if (newval == ZFS_XATTR_OFF) {
343 zfsvfs->z_flags &= ~ZSB_XATTR;
344 } else {
345 zfsvfs->z_flags |= ZSB_XATTR;
346
347 if (newval == ZFS_XATTR_SA)
348 zfsvfs->z_xattr_sa = B_TRUE;
349 else
350 zfsvfs->z_xattr_sa = B_FALSE;
351 }
352 }
353
354 static void
acltype_changed_cb(void * arg,uint64_t newval)355 acltype_changed_cb(void *arg, uint64_t newval)
356 {
357 zfsvfs_t *zfsvfs = arg;
358
359 switch (newval) {
360 case ZFS_ACLTYPE_NFSV4:
361 case ZFS_ACLTYPE_OFF:
362 zfsvfs->z_acl_type = ZFS_ACLTYPE_OFF;
363 zfsvfs->z_sb->s_flags &= ~SB_POSIXACL;
364 break;
365 case ZFS_ACLTYPE_POSIX:
366 #ifdef CONFIG_FS_POSIX_ACL
367 zfsvfs->z_acl_type = ZFS_ACLTYPE_POSIX;
368 zfsvfs->z_sb->s_flags |= SB_POSIXACL;
369 #else
370 zfsvfs->z_acl_type = ZFS_ACLTYPE_OFF;
371 zfsvfs->z_sb->s_flags &= ~SB_POSIXACL;
372 #endif /* CONFIG_FS_POSIX_ACL */
373 break;
374 default:
375 break;
376 }
377 }
378
379 static void
blksz_changed_cb(void * arg,uint64_t newval)380 blksz_changed_cb(void *arg, uint64_t newval)
381 {
382 zfsvfs_t *zfsvfs = arg;
383 ASSERT3U(newval, <=, spa_maxblocksize(dmu_objset_spa(zfsvfs->z_os)));
384 ASSERT3U(newval, >=, SPA_MINBLOCKSIZE);
385 ASSERT(ISP2(newval));
386
387 zfsvfs->z_max_blksz = newval;
388 }
389
390 static void
readonly_changed_cb(void * arg,uint64_t newval)391 readonly_changed_cb(void *arg, uint64_t newval)
392 {
393 zfsvfs_t *zfsvfs = arg;
394 struct super_block *sb = zfsvfs->z_sb;
395
396 if (sb == NULL)
397 return;
398
399 if (newval)
400 sb->s_flags |= SB_RDONLY;
401 else
402 sb->s_flags &= ~SB_RDONLY;
403 }
404
405 static void
devices_changed_cb(void * arg,uint64_t newval)406 devices_changed_cb(void *arg, uint64_t newval)
407 {
408 }
409
410 static void
setuid_changed_cb(void * arg,uint64_t newval)411 setuid_changed_cb(void *arg, uint64_t newval)
412 {
413 }
414
415 static void
exec_changed_cb(void * arg,uint64_t newval)416 exec_changed_cb(void *arg, uint64_t newval)
417 {
418 }
419
420 static void
nbmand_changed_cb(void * arg,uint64_t newval)421 nbmand_changed_cb(void *arg, uint64_t newval)
422 {
423 zfsvfs_t *zfsvfs = arg;
424 struct super_block *sb = zfsvfs->z_sb;
425
426 if (sb == NULL)
427 return;
428
429 if (newval == TRUE)
430 sb->s_flags |= SB_MANDLOCK;
431 else
432 sb->s_flags &= ~SB_MANDLOCK;
433 }
434
435 static void
snapdir_changed_cb(void * arg,uint64_t newval)436 snapdir_changed_cb(void *arg, uint64_t newval)
437 {
438 ((zfsvfs_t *)arg)->z_show_ctldir = newval;
439 }
440
441 static void
acl_mode_changed_cb(void * arg,uint64_t newval)442 acl_mode_changed_cb(void *arg, uint64_t newval)
443 {
444 zfsvfs_t *zfsvfs = arg;
445
446 zfsvfs->z_acl_mode = newval;
447 }
448
449 static void
acl_inherit_changed_cb(void * arg,uint64_t newval)450 acl_inherit_changed_cb(void *arg, uint64_t newval)
451 {
452 ((zfsvfs_t *)arg)->z_acl_inherit = newval;
453 }
454
455 static void
longname_changed_cb(void * arg,uint64_t newval)456 longname_changed_cb(void *arg, uint64_t newval)
457 {
458 ((zfsvfs_t *)arg)->z_longname = newval;
459 }
460
461 static int
zfs_register_callbacks(vfs_t * vfsp)462 zfs_register_callbacks(vfs_t *vfsp)
463 {
464 struct dsl_dataset *ds = NULL;
465 objset_t *os = NULL;
466 zfsvfs_t *zfsvfs = NULL;
467 int error = 0;
468
469 ASSERT(vfsp);
470 zfsvfs = vfsp->vfs_data;
471 ASSERT(zfsvfs);
472 os = zfsvfs->z_os;
473
474 /*
475 * The act of registering our callbacks will destroy any mount
476 * options we may have. In order to enable temporary overrides
477 * of mount options, we stash away the current values and
478 * restore them after we register the callbacks.
479 */
480 if (zfs_is_readonly(zfsvfs) || !spa_writeable(dmu_objset_spa(os))) {
481 vfsp->vfs_do_readonly = B_TRUE;
482 vfsp->vfs_readonly = B_TRUE;
483 }
484
485 /*
486 * Register property callbacks.
487 *
488 * It would probably be fine to just check for i/o error from
489 * the first prop_register(), but I guess I like to go
490 * overboard...
491 */
492 ds = dmu_objset_ds(os);
493 dsl_pool_config_enter(dmu_objset_pool(os), FTAG);
494 error = dsl_prop_register(ds,
495 zfs_prop_to_name(ZFS_PROP_ATIME), atime_changed_cb, zfsvfs);
496 error = error ? error : dsl_prop_register(ds,
497 zfs_prop_to_name(ZFS_PROP_RELATIME), relatime_changed_cb, zfsvfs);
498 error = error ? error : dsl_prop_register(ds,
499 zfs_prop_to_name(ZFS_PROP_XATTR), xattr_changed_cb, zfsvfs);
500 error = error ? error : dsl_prop_register(ds,
501 zfs_prop_to_name(ZFS_PROP_RECORDSIZE), blksz_changed_cb, zfsvfs);
502 error = error ? error : dsl_prop_register(ds,
503 zfs_prop_to_name(ZFS_PROP_READONLY), readonly_changed_cb, zfsvfs);
504 error = error ? error : dsl_prop_register(ds,
505 zfs_prop_to_name(ZFS_PROP_DEVICES), devices_changed_cb, zfsvfs);
506 error = error ? error : dsl_prop_register(ds,
507 zfs_prop_to_name(ZFS_PROP_SETUID), setuid_changed_cb, zfsvfs);
508 error = error ? error : dsl_prop_register(ds,
509 zfs_prop_to_name(ZFS_PROP_EXEC), exec_changed_cb, zfsvfs);
510 error = error ? error : dsl_prop_register(ds,
511 zfs_prop_to_name(ZFS_PROP_SNAPDIR), snapdir_changed_cb, zfsvfs);
512 error = error ? error : dsl_prop_register(ds,
513 zfs_prop_to_name(ZFS_PROP_ACLTYPE), acltype_changed_cb, zfsvfs);
514 error = error ? error : dsl_prop_register(ds,
515 zfs_prop_to_name(ZFS_PROP_ACLMODE), acl_mode_changed_cb, zfsvfs);
516 error = error ? error : dsl_prop_register(ds,
517 zfs_prop_to_name(ZFS_PROP_ACLINHERIT), acl_inherit_changed_cb,
518 zfsvfs);
519 error = error ? error : dsl_prop_register(ds,
520 zfs_prop_to_name(ZFS_PROP_NBMAND), nbmand_changed_cb, zfsvfs);
521 error = error ? error : dsl_prop_register(ds,
522 zfs_prop_to_name(ZFS_PROP_LONGNAME), longname_changed_cb, zfsvfs);
523 dsl_pool_config_exit(dmu_objset_pool(os), FTAG);
524 if (error)
525 goto unregister;
526
527 /*
528 * Invoke our callbacks to restore temporary mount options.
529 */
530 if (vfsp->vfs_do_readonly)
531 readonly_changed_cb(zfsvfs, vfsp->vfs_readonly);
532 if (vfsp->vfs_do_setuid)
533 setuid_changed_cb(zfsvfs, vfsp->vfs_setuid);
534 if (vfsp->vfs_do_exec)
535 exec_changed_cb(zfsvfs, vfsp->vfs_exec);
536 if (vfsp->vfs_do_devices)
537 devices_changed_cb(zfsvfs, vfsp->vfs_devices);
538 if (vfsp->vfs_do_xattr)
539 xattr_changed_cb(zfsvfs, vfsp->vfs_xattr);
540 if (vfsp->vfs_do_atime)
541 atime_changed_cb(zfsvfs, vfsp->vfs_atime);
542 if (vfsp->vfs_do_relatime)
543 relatime_changed_cb(zfsvfs, vfsp->vfs_relatime);
544 if (vfsp->vfs_do_nbmand)
545 nbmand_changed_cb(zfsvfs, vfsp->vfs_nbmand);
546
547 return (0);
548
549 unregister:
550 dsl_prop_unregister_all(ds, zfsvfs);
551 return (error);
552 }
553
554 /*
555 * Takes a dataset, a property, a value and that value's setpoint as
556 * found in the ZAP. Checks if the property has been changed in the vfs.
557 * If so, val and setpoint will be overwritten with updated content.
558 * Otherwise, they are left unchanged.
559 */
560 int
zfs_get_temporary_prop(dsl_dataset_t * ds,zfs_prop_t zfs_prop,uint64_t * val,char * setpoint)561 zfs_get_temporary_prop(dsl_dataset_t *ds, zfs_prop_t zfs_prop, uint64_t *val,
562 char *setpoint)
563 {
564 int error;
565 zfsvfs_t *zfvp;
566 vfs_t *vfsp;
567 objset_t *os;
568 uint64_t tmp = *val;
569
570 error = dmu_objset_from_ds(ds, &os);
571 if (error != 0)
572 return (error);
573
574 if (dmu_objset_type(os) != DMU_OST_ZFS)
575 return (EINVAL);
576
577 mutex_enter(&os->os_user_ptr_lock);
578 zfvp = dmu_objset_get_user(os);
579 mutex_exit(&os->os_user_ptr_lock);
580 if (zfvp == NULL)
581 return (ESRCH);
582
583 vfsp = zfvp->z_vfs;
584
585 switch (zfs_prop) {
586 case ZFS_PROP_ATIME:
587 if (vfsp->vfs_do_atime)
588 tmp = vfsp->vfs_atime;
589 break;
590 case ZFS_PROP_RELATIME:
591 if (vfsp->vfs_do_relatime)
592 tmp = vfsp->vfs_relatime;
593 break;
594 case ZFS_PROP_DEVICES:
595 if (vfsp->vfs_do_devices)
596 tmp = vfsp->vfs_devices;
597 break;
598 case ZFS_PROP_EXEC:
599 if (vfsp->vfs_do_exec)
600 tmp = vfsp->vfs_exec;
601 break;
602 case ZFS_PROP_SETUID:
603 if (vfsp->vfs_do_setuid)
604 tmp = vfsp->vfs_setuid;
605 break;
606 case ZFS_PROP_READONLY:
607 if (vfsp->vfs_do_readonly)
608 tmp = vfsp->vfs_readonly;
609 break;
610 case ZFS_PROP_XATTR:
611 if (vfsp->vfs_do_xattr)
612 tmp = vfsp->vfs_xattr;
613 break;
614 case ZFS_PROP_NBMAND:
615 if (vfsp->vfs_do_nbmand)
616 tmp = vfsp->vfs_nbmand;
617 break;
618 default:
619 return (ENOENT);
620 }
621
622 if (tmp != *val) {
623 if (setpoint)
624 (void) strcpy(setpoint, "temporary");
625 *val = tmp;
626 }
627 return (0);
628 }
629
630 /*
631 * Associate this zfsvfs with the given objset, which must be owned.
632 * This will cache a bunch of on-disk state from the objset in the
633 * zfsvfs.
634 */
635 static int
zfsvfs_init(zfsvfs_t * zfsvfs,objset_t * os)636 zfsvfs_init(zfsvfs_t *zfsvfs, objset_t *os)
637 {
638 int error;
639 uint64_t val;
640
641 zfsvfs->z_max_blksz = SPA_OLD_MAXBLOCKSIZE;
642 zfsvfs->z_show_ctldir = ZFS_SNAPDIR_VISIBLE;
643 zfsvfs->z_os = os;
644
645 error = zfs_get_zplprop(os, ZFS_PROP_VERSION, &zfsvfs->z_version);
646 if (error != 0)
647 return (error);
648 if (zfsvfs->z_version >
649 zfs_zpl_version_map(spa_version(dmu_objset_spa(os)))) {
650 (void) printk("Can't mount a version %lld file system "
651 "on a version %lld pool\n. Pool must be upgraded to mount "
652 "this file system.\n", (u_longlong_t)zfsvfs->z_version,
653 (u_longlong_t)spa_version(dmu_objset_spa(os)));
654 return (SET_ERROR(ENOTSUP));
655 }
656 error = zfs_get_zplprop(os, ZFS_PROP_NORMALIZE, &val);
657 if (error != 0)
658 return (error);
659 zfsvfs->z_norm = (int)val;
660
661 error = zfs_get_zplprop(os, ZFS_PROP_UTF8ONLY, &val);
662 if (error != 0)
663 return (error);
664 zfsvfs->z_utf8 = (val != 0);
665
666 error = zfs_get_zplprop(os, ZFS_PROP_CASE, &val);
667 if (error != 0)
668 return (error);
669 zfsvfs->z_case = (uint_t)val;
670
671 if ((error = zfs_get_zplprop(os, ZFS_PROP_ACLTYPE, &val)) != 0)
672 return (error);
673 zfsvfs->z_acl_type = (uint_t)val;
674
675 /*
676 * Fold case on file systems that are always or sometimes case
677 * insensitive.
678 */
679 if (zfsvfs->z_case == ZFS_CASE_INSENSITIVE ||
680 zfsvfs->z_case == ZFS_CASE_MIXED)
681 zfsvfs->z_norm |= U8_TEXTPREP_TOUPPER;
682
683 zfsvfs->z_use_fuids = USE_FUIDS(zfsvfs->z_version, zfsvfs->z_os);
684 zfsvfs->z_use_sa = USE_SA(zfsvfs->z_version, zfsvfs->z_os);
685
686 uint64_t sa_obj = 0;
687 if (zfsvfs->z_use_sa) {
688 /* should either have both of these objects or none */
689 error = zap_lookup(os, MASTER_NODE_OBJ, ZFS_SA_ATTRS, 8, 1,
690 &sa_obj);
691 if (error != 0)
692 return (error);
693
694 error = zfs_get_zplprop(os, ZFS_PROP_XATTR, &val);
695 if ((error == 0) && (val == ZFS_XATTR_SA))
696 zfsvfs->z_xattr_sa = B_TRUE;
697 }
698
699 error = zap_lookup(os, MASTER_NODE_OBJ, ZFS_ROOT_OBJ, 8, 1,
700 &zfsvfs->z_root);
701 if (error != 0)
702 return (error);
703 ASSERT(zfsvfs->z_root != 0);
704
705 error = zap_lookup(os, MASTER_NODE_OBJ, ZFS_UNLINKED_SET, 8, 1,
706 &zfsvfs->z_unlinkedobj);
707 if (error != 0)
708 return (error);
709
710 error = zap_lookup(os, MASTER_NODE_OBJ,
711 zfs_userquota_prop_prefixes[ZFS_PROP_USERQUOTA],
712 8, 1, &zfsvfs->z_userquota_obj);
713 if (error == ENOENT)
714 zfsvfs->z_userquota_obj = 0;
715 else if (error != 0)
716 return (error);
717
718 error = zap_lookup(os, MASTER_NODE_OBJ,
719 zfs_userquota_prop_prefixes[ZFS_PROP_GROUPQUOTA],
720 8, 1, &zfsvfs->z_groupquota_obj);
721 if (error == ENOENT)
722 zfsvfs->z_groupquota_obj = 0;
723 else if (error != 0)
724 return (error);
725
726 error = zap_lookup(os, MASTER_NODE_OBJ,
727 zfs_userquota_prop_prefixes[ZFS_PROP_PROJECTQUOTA],
728 8, 1, &zfsvfs->z_projectquota_obj);
729 if (error == ENOENT)
730 zfsvfs->z_projectquota_obj = 0;
731 else if (error != 0)
732 return (error);
733
734 error = zap_lookup(os, MASTER_NODE_OBJ,
735 zfs_userquota_prop_prefixes[ZFS_PROP_USEROBJQUOTA],
736 8, 1, &zfsvfs->z_userobjquota_obj);
737 if (error == ENOENT)
738 zfsvfs->z_userobjquota_obj = 0;
739 else if (error != 0)
740 return (error);
741
742 error = zap_lookup(os, MASTER_NODE_OBJ,
743 zfs_userquota_prop_prefixes[ZFS_PROP_GROUPOBJQUOTA],
744 8, 1, &zfsvfs->z_groupobjquota_obj);
745 if (error == ENOENT)
746 zfsvfs->z_groupobjquota_obj = 0;
747 else if (error != 0)
748 return (error);
749
750 error = zap_lookup(os, MASTER_NODE_OBJ,
751 zfs_userquota_prop_prefixes[ZFS_PROP_PROJECTOBJQUOTA],
752 8, 1, &zfsvfs->z_projectobjquota_obj);
753 if (error == ENOENT)
754 zfsvfs->z_projectobjquota_obj = 0;
755 else if (error != 0)
756 return (error);
757
758 error = zap_lookup(os, MASTER_NODE_OBJ, ZFS_FUID_TABLES, 8, 1,
759 &zfsvfs->z_fuid_obj);
760 if (error == ENOENT)
761 zfsvfs->z_fuid_obj = 0;
762 else if (error != 0)
763 return (error);
764
765 error = zap_lookup(os, MASTER_NODE_OBJ, ZFS_SHARES_DIR, 8, 1,
766 &zfsvfs->z_shares_dir);
767 if (error == ENOENT)
768 zfsvfs->z_shares_dir = 0;
769 else if (error != 0)
770 return (error);
771
772 error = sa_setup(os, sa_obj, zfs_attr_table, ZPL_END,
773 &zfsvfs->z_attr_table);
774 if (error != 0)
775 return (error);
776
777 if (zfsvfs->z_version >= ZPL_VERSION_SA)
778 sa_register_update_callback(os, zfs_sa_upgrade);
779
780 return (0);
781 }
782
783 int
zfsvfs_create(const char * osname,boolean_t readonly,zfsvfs_t ** zfvp)784 zfsvfs_create(const char *osname, boolean_t readonly, zfsvfs_t **zfvp)
785 {
786 objset_t *os;
787 zfsvfs_t *zfsvfs;
788 int error;
789 boolean_t ro = (readonly || (strchr(osname, '@') != NULL));
790
791 zfsvfs = kmem_zalloc(sizeof (zfsvfs_t), KM_SLEEP);
792
793 error = dmu_objset_own(osname, DMU_OST_ZFS, ro, B_TRUE, zfsvfs, &os);
794 if (error != 0) {
795 kmem_free(zfsvfs, sizeof (zfsvfs_t));
796 return (error);
797 }
798
799 error = zfsvfs_create_impl(zfvp, zfsvfs, os);
800
801 return (error);
802 }
803
804
805 /*
806 * Note: zfsvfs is assumed to be malloc'd, and will be freed by this function
807 * on a failure. Do not pass in a statically allocated zfsvfs.
808 */
809 int
zfsvfs_create_impl(zfsvfs_t ** zfvp,zfsvfs_t * zfsvfs,objset_t * os)810 zfsvfs_create_impl(zfsvfs_t **zfvp, zfsvfs_t *zfsvfs, objset_t *os)
811 {
812 int error;
813
814 zfsvfs->z_vfs = NULL;
815 zfsvfs->z_sb = NULL;
816 zfsvfs->z_parent = zfsvfs;
817
818 mutex_init(&zfsvfs->z_znodes_lock, NULL, MUTEX_DEFAULT, NULL);
819 mutex_init(&zfsvfs->z_lock, NULL, MUTEX_DEFAULT, NULL);
820 list_create(&zfsvfs->z_all_znodes, sizeof (znode_t),
821 offsetof(znode_t, z_link_node));
822 ZFS_TEARDOWN_INIT(zfsvfs);
823 rw_init(&zfsvfs->z_teardown_inactive_lock, NULL, RW_DEFAULT, NULL);
824 rw_init(&zfsvfs->z_fuid_lock, NULL, RW_DEFAULT, NULL);
825
826 int size = MIN(1 << (highbit64(zfs_object_mutex_size) - 1),
827 ZFS_OBJ_MTX_MAX);
828 zfsvfs->z_hold_size = size;
829 zfsvfs->z_hold_trees = vmem_zalloc(sizeof (avl_tree_t) * size,
830 KM_SLEEP);
831 zfsvfs->z_hold_locks = vmem_zalloc(sizeof (kmutex_t) * size, KM_SLEEP);
832 for (int i = 0; i != size; i++) {
833 avl_create(&zfsvfs->z_hold_trees[i], zfs_znode_hold_compare,
834 sizeof (znode_hold_t), offsetof(znode_hold_t, zh_node));
835 mutex_init(&zfsvfs->z_hold_locks[i], NULL, MUTEX_DEFAULT, NULL);
836 }
837
838 error = zfsvfs_init(zfsvfs, os);
839 if (error != 0) {
840 dmu_objset_disown(os, B_TRUE, zfsvfs);
841 *zfvp = NULL;
842 zfsvfs_free(zfsvfs);
843 return (error);
844 }
845
846 zfsvfs->z_drain_task = TASKQID_INVALID;
847 zfsvfs->z_draining = B_FALSE;
848 zfsvfs->z_drain_cancel = B_TRUE;
849
850 *zfvp = zfsvfs;
851 return (0);
852 }
853
854 static int
zfsvfs_setup(zfsvfs_t * zfsvfs,boolean_t mounting)855 zfsvfs_setup(zfsvfs_t *zfsvfs, boolean_t mounting)
856 {
857 int error;
858 boolean_t readonly = zfs_is_readonly(zfsvfs);
859
860 error = zfs_register_callbacks(zfsvfs->z_vfs);
861 if (error)
862 return (error);
863
864 /*
865 * If we are not mounting (ie: online recv), then we don't
866 * have to worry about replaying the log as we blocked all
867 * operations out since we closed the ZIL.
868 */
869 if (mounting) {
870 ASSERT3P(zfsvfs->z_kstat.dk_kstats, ==, NULL);
871 error = dataset_kstats_create(&zfsvfs->z_kstat, zfsvfs->z_os);
872 if (error)
873 return (error);
874 zfsvfs->z_log = zil_open(zfsvfs->z_os, zfs_get_data,
875 &zfsvfs->z_kstat.dk_zil_sums);
876
877 /*
878 * During replay we remove the read only flag to
879 * allow replays to succeed.
880 */
881 if (readonly != 0) {
882 readonly_changed_cb(zfsvfs, B_FALSE);
883 } else {
884 zap_stats_t zs;
885 if (zap_get_stats(zfsvfs->z_os, zfsvfs->z_unlinkedobj,
886 &zs) == 0) {
887 dataset_kstats_update_nunlinks_kstat(
888 &zfsvfs->z_kstat, zs.zs_num_entries);
889 dprintf_ds(zfsvfs->z_os->os_dsl_dataset,
890 "num_entries in unlinked set: %llu",
891 zs.zs_num_entries);
892 }
893 zfs_unlinked_drain(zfsvfs);
894 dsl_dir_t *dd = zfsvfs->z_os->os_dsl_dataset->ds_dir;
895 dd->dd_activity_cancelled = B_FALSE;
896 }
897
898 /*
899 * Parse and replay the intent log.
900 *
901 * Because of ziltest, this must be done after
902 * zfs_unlinked_drain(). (Further note: ziltest
903 * doesn't use readonly mounts, where
904 * zfs_unlinked_drain() isn't called.) This is because
905 * ziltest causes spa_sync() to think it's committed,
906 * but actually it is not, so the intent log contains
907 * many txg's worth of changes.
908 *
909 * In particular, if object N is in the unlinked set in
910 * the last txg to actually sync, then it could be
911 * actually freed in a later txg and then reallocated
912 * in a yet later txg. This would write a "create
913 * object N" record to the intent log. Normally, this
914 * would be fine because the spa_sync() would have
915 * written out the fact that object N is free, before
916 * we could write the "create object N" intent log
917 * record.
918 *
919 * But when we are in ziltest mode, we advance the "open
920 * txg" without actually spa_sync()-ing the changes to
921 * disk. So we would see that object N is still
922 * allocated and in the unlinked set, and there is an
923 * intent log record saying to allocate it.
924 */
925 if (spa_writeable(dmu_objset_spa(zfsvfs->z_os))) {
926 if (zil_replay_disable) {
927 zil_destroy(zfsvfs->z_log, B_FALSE);
928 } else {
929 zfsvfs->z_replay = B_TRUE;
930 zil_replay(zfsvfs->z_os, zfsvfs,
931 zfs_replay_vector);
932 zfsvfs->z_replay = B_FALSE;
933 }
934 }
935
936 /* restore readonly bit */
937 if (readonly != 0)
938 readonly_changed_cb(zfsvfs, B_TRUE);
939 } else {
940 ASSERT3P(zfsvfs->z_kstat.dk_kstats, !=, NULL);
941 zfsvfs->z_log = zil_open(zfsvfs->z_os, zfs_get_data,
942 &zfsvfs->z_kstat.dk_zil_sums);
943 }
944
945 /*
946 * Set the objset user_ptr to track its zfsvfs.
947 */
948 mutex_enter(&zfsvfs->z_os->os_user_ptr_lock);
949 dmu_objset_set_user(zfsvfs->z_os, zfsvfs);
950 mutex_exit(&zfsvfs->z_os->os_user_ptr_lock);
951
952 return (0);
953 }
954
955 void
zfsvfs_free(zfsvfs_t * zfsvfs)956 zfsvfs_free(zfsvfs_t *zfsvfs)
957 {
958 int i, size = zfsvfs->z_hold_size;
959
960 zfs_fuid_destroy(zfsvfs);
961
962 mutex_destroy(&zfsvfs->z_znodes_lock);
963 mutex_destroy(&zfsvfs->z_lock);
964 list_destroy(&zfsvfs->z_all_znodes);
965 ZFS_TEARDOWN_DESTROY(zfsvfs);
966 rw_destroy(&zfsvfs->z_teardown_inactive_lock);
967 rw_destroy(&zfsvfs->z_fuid_lock);
968 for (i = 0; i != size; i++) {
969 avl_destroy(&zfsvfs->z_hold_trees[i]);
970 mutex_destroy(&zfsvfs->z_hold_locks[i]);
971 }
972 vmem_free(zfsvfs->z_hold_trees, sizeof (avl_tree_t) * size);
973 vmem_free(zfsvfs->z_hold_locks, sizeof (kmutex_t) * size);
974 zfsvfs_vfs_free(zfsvfs->z_vfs);
975 dataset_kstats_destroy(&zfsvfs->z_kstat);
976 kmem_free(zfsvfs, sizeof (zfsvfs_t));
977 }
978
979 static void
zfs_set_fuid_feature(zfsvfs_t * zfsvfs)980 zfs_set_fuid_feature(zfsvfs_t *zfsvfs)
981 {
982 zfsvfs->z_use_fuids = USE_FUIDS(zfsvfs->z_version, zfsvfs->z_os);
983 zfsvfs->z_use_sa = USE_SA(zfsvfs->z_version, zfsvfs->z_os);
984 }
985
986 static void
zfs_unregister_callbacks(zfsvfs_t * zfsvfs)987 zfs_unregister_callbacks(zfsvfs_t *zfsvfs)
988 {
989 objset_t *os = zfsvfs->z_os;
990
991 if (!dmu_objset_is_snapshot(os))
992 dsl_prop_unregister_all(dmu_objset_ds(os), zfsvfs);
993 }
994
995 #ifdef HAVE_MLSLABEL
996 /*
997 * Check that the hex label string is appropriate for the dataset being
998 * mounted into the global_zone proper.
999 *
1000 * Return an error if the hex label string is not default or
1001 * admin_low/admin_high. For admin_low labels, the corresponding
1002 * dataset must be readonly.
1003 */
1004 int
zfs_check_global_label(const char * dsname,const char * hexsl)1005 zfs_check_global_label(const char *dsname, const char *hexsl)
1006 {
1007 if (strcasecmp(hexsl, ZFS_MLSLABEL_DEFAULT) == 0)
1008 return (0);
1009 if (strcasecmp(hexsl, ADMIN_HIGH) == 0)
1010 return (0);
1011 if (strcasecmp(hexsl, ADMIN_LOW) == 0) {
1012 /* must be readonly */
1013 uint64_t rdonly;
1014
1015 if (dsl_prop_get_integer(dsname,
1016 zfs_prop_to_name(ZFS_PROP_READONLY), &rdonly, NULL))
1017 return (SET_ERROR(EACCES));
1018 return (rdonly ? 0 : SET_ERROR(EACCES));
1019 }
1020 return (SET_ERROR(EACCES));
1021 }
1022 #endif /* HAVE_MLSLABEL */
1023
1024 static int
zfs_statfs_project(zfsvfs_t * zfsvfs,znode_t * zp,struct kstatfs * statp,uint32_t bshift)1025 zfs_statfs_project(zfsvfs_t *zfsvfs, znode_t *zp, struct kstatfs *statp,
1026 uint32_t bshift)
1027 {
1028 char buf[20 + DMU_OBJACCT_PREFIX_LEN];
1029 uint64_t offset = DMU_OBJACCT_PREFIX_LEN;
1030 uint64_t quota;
1031 uint64_t used;
1032 int err;
1033
1034 strlcpy(buf, DMU_OBJACCT_PREFIX, DMU_OBJACCT_PREFIX_LEN + 1);
1035 err = zfs_id_to_fuidstr(zfsvfs, NULL, zp->z_projid, buf + offset,
1036 sizeof (buf) - offset, B_FALSE);
1037 if (err)
1038 return (err);
1039
1040 if (zfsvfs->z_projectquota_obj == 0)
1041 goto objs;
1042
1043 err = zap_lookup(zfsvfs->z_os, zfsvfs->z_projectquota_obj,
1044 buf + offset, 8, 1, "a);
1045 if (err == ENOENT)
1046 goto objs;
1047 else if (err)
1048 return (err);
1049
1050 err = zap_lookup(zfsvfs->z_os, DMU_PROJECTUSED_OBJECT,
1051 buf + offset, 8, 1, &used);
1052 if (unlikely(err == ENOENT)) {
1053 uint32_t blksize;
1054 u_longlong_t nblocks;
1055
1056 /*
1057 * Quota accounting is async, so it is possible race case.
1058 * There is at least one object with the given project ID.
1059 */
1060 sa_object_size(zp->z_sa_hdl, &blksize, &nblocks);
1061 if (unlikely(zp->z_blksz == 0))
1062 blksize = zfsvfs->z_max_blksz;
1063
1064 used = blksize * nblocks;
1065 } else if (err) {
1066 return (err);
1067 }
1068
1069 statp->f_blocks = quota >> bshift;
1070 statp->f_bfree = (quota > used) ? ((quota - used) >> bshift) : 0;
1071 statp->f_bavail = statp->f_bfree;
1072
1073 objs:
1074 if (zfsvfs->z_projectobjquota_obj == 0)
1075 return (0);
1076
1077 err = zap_lookup(zfsvfs->z_os, zfsvfs->z_projectobjquota_obj,
1078 buf + offset, 8, 1, "a);
1079 if (err == ENOENT)
1080 return (0);
1081 else if (err)
1082 return (err);
1083
1084 err = zap_lookup(zfsvfs->z_os, DMU_PROJECTUSED_OBJECT,
1085 buf, 8, 1, &used);
1086 if (unlikely(err == ENOENT)) {
1087 /*
1088 * Quota accounting is async, so it is possible race case.
1089 * There is at least one object with the given project ID.
1090 */
1091 used = 1;
1092 } else if (err) {
1093 return (err);
1094 }
1095
1096 statp->f_files = quota;
1097 statp->f_ffree = (quota > used) ? (quota - used) : 0;
1098
1099 return (0);
1100 }
1101
1102 int
zfs_statvfs(struct inode * ip,struct kstatfs * statp)1103 zfs_statvfs(struct inode *ip, struct kstatfs *statp)
1104 {
1105 zfsvfs_t *zfsvfs = ITOZSB(ip);
1106 uint64_t refdbytes, availbytes, usedobjs, availobjs;
1107 int err = 0;
1108
1109 if ((err = zfs_enter(zfsvfs, FTAG)) != 0)
1110 return (err);
1111
1112 dmu_objset_space(zfsvfs->z_os,
1113 &refdbytes, &availbytes, &usedobjs, &availobjs);
1114
1115 uint64_t fsid = dmu_objset_fsid_guid(zfsvfs->z_os);
1116 /*
1117 * The underlying storage pool actually uses multiple block
1118 * size. Under Solaris frsize (fragment size) is reported as
1119 * the smallest block size we support, and bsize (block size)
1120 * as the filesystem's maximum block size. Unfortunately,
1121 * under Linux the fragment size and block size are often used
1122 * interchangeably. Thus we are forced to report both of them
1123 * as the filesystem's maximum block size.
1124 */
1125 statp->f_frsize = zfsvfs->z_max_blksz;
1126 statp->f_bsize = zfsvfs->z_max_blksz;
1127 uint32_t bshift = fls(statp->f_bsize) - 1;
1128
1129 /*
1130 * The following report "total" blocks of various kinds in
1131 * the file system, but reported in terms of f_bsize - the
1132 * "preferred" size.
1133 */
1134
1135 /* Round up so we never have a filesystem using 0 blocks. */
1136 refdbytes = P2ROUNDUP(refdbytes, statp->f_bsize);
1137 statp->f_blocks = (refdbytes + availbytes) >> bshift;
1138 statp->f_bfree = availbytes >> bshift;
1139 statp->f_bavail = statp->f_bfree; /* no root reservation */
1140
1141 /*
1142 * statvfs() should really be called statufs(), because it assumes
1143 * static metadata. ZFS doesn't preallocate files, so the best
1144 * we can do is report the max that could possibly fit in f_files,
1145 * and that minus the number actually used in f_ffree.
1146 * For f_ffree, report the smaller of the number of objects available
1147 * and the number of blocks (each object will take at least a block).
1148 */
1149 statp->f_ffree = MIN(availobjs, availbytes >> DNODE_SHIFT);
1150 statp->f_files = statp->f_ffree + usedobjs;
1151 statp->f_fsid.val[0] = (uint32_t)fsid;
1152 statp->f_fsid.val[1] = (uint32_t)(fsid >> 32);
1153 statp->f_type = ZFS_SUPER_MAGIC;
1154 statp->f_namelen =
1155 zfsvfs->z_longname ? (ZAP_MAXNAMELEN_NEW - 1) : (MAXNAMELEN - 1);
1156
1157 /*
1158 * We have all of 40 characters to stuff a string here.
1159 * Is there anything useful we could/should provide?
1160 */
1161 memset(statp->f_spare, 0, sizeof (statp->f_spare));
1162
1163 if (dmu_objset_projectquota_enabled(zfsvfs->z_os) &&
1164 dmu_objset_projectquota_present(zfsvfs->z_os)) {
1165 znode_t *zp = ITOZ(ip);
1166
1167 if (zp->z_pflags & ZFS_PROJINHERIT && zp->z_projid &&
1168 zpl_is_valid_projid(zp->z_projid))
1169 err = zfs_statfs_project(zfsvfs, zp, statp, bshift);
1170 }
1171
1172 zfs_exit(zfsvfs, FTAG);
1173 return (err);
1174 }
1175
1176 static int
zfs_root(zfsvfs_t * zfsvfs,struct inode ** ipp)1177 zfs_root(zfsvfs_t *zfsvfs, struct inode **ipp)
1178 {
1179 znode_t *rootzp;
1180 int error;
1181
1182 if ((error = zfs_enter(zfsvfs, FTAG)) != 0)
1183 return (error);
1184
1185 error = zfs_zget(zfsvfs, zfsvfs->z_root, &rootzp);
1186 if (error == 0)
1187 *ipp = ZTOI(rootzp);
1188
1189 zfs_exit(zfsvfs, FTAG);
1190 return (error);
1191 }
1192
1193 /*
1194 * The ARC has requested that the filesystem drop entries from the dentry
1195 * and inode caches. This can occur when the ARC needs to free meta data
1196 * blocks but can't because they are all pinned by entries in these caches.
1197 */
1198 #if defined(HAVE_SUPER_BLOCK_S_SHRINK)
1199 #define S_SHRINK(sb) (&(sb)->s_shrink)
1200 #elif defined(HAVE_SUPER_BLOCK_S_SHRINK_PTR)
1201 #define S_SHRINK(sb) ((sb)->s_shrink)
1202 #endif
1203
1204 int
zfs_prune(struct super_block * sb,unsigned long nr_to_scan,int * objects)1205 zfs_prune(struct super_block *sb, unsigned long nr_to_scan, int *objects)
1206 {
1207 zfsvfs_t *zfsvfs = sb->s_fs_info;
1208 int error = 0;
1209 struct shrinker *shrinker = S_SHRINK(sb);
1210 struct shrink_control sc = {
1211 .nr_to_scan = nr_to_scan,
1212 .gfp_mask = GFP_KERNEL,
1213 };
1214
1215 if ((error = zfs_enter(zfsvfs, FTAG)) != 0)
1216 return (error);
1217
1218 #ifdef SHRINKER_NUMA_AWARE
1219 if (shrinker->flags & SHRINKER_NUMA_AWARE) {
1220 long tc = 1;
1221 for_each_online_node(sc.nid) {
1222 long c = shrinker->count_objects(shrinker, &sc);
1223 if (c == 0 || c == SHRINK_EMPTY)
1224 continue;
1225 tc += c;
1226 }
1227 *objects = 0;
1228 for_each_online_node(sc.nid) {
1229 long c = shrinker->count_objects(shrinker, &sc);
1230 if (c == 0 || c == SHRINK_EMPTY)
1231 continue;
1232 if (c > tc)
1233 tc = c;
1234 sc.nr_to_scan = mult_frac(nr_to_scan, c, tc) + 1;
1235 *objects += (*shrinker->scan_objects)(shrinker, &sc);
1236 }
1237 } else {
1238 *objects = (*shrinker->scan_objects)(shrinker, &sc);
1239 }
1240 #else
1241 *objects = (*shrinker->scan_objects)(shrinker, &sc);
1242 #endif
1243
1244 zfs_exit(zfsvfs, FTAG);
1245
1246 dprintf_ds(zfsvfs->z_os->os_dsl_dataset,
1247 "pruning, nr_to_scan=%lu objects=%d error=%d\n",
1248 nr_to_scan, *objects, error);
1249
1250 return (error);
1251 }
1252
1253 /*
1254 * Teardown the zfsvfs_t.
1255 *
1256 * Note, if 'unmounting' is FALSE, we return with the 'z_teardown_lock'
1257 * and 'z_teardown_inactive_lock' held.
1258 */
1259 static int
zfsvfs_teardown(zfsvfs_t * zfsvfs,boolean_t unmounting)1260 zfsvfs_teardown(zfsvfs_t *zfsvfs, boolean_t unmounting)
1261 {
1262 znode_t *zp;
1263
1264 zfs_unlinked_drain_stop_wait(zfsvfs);
1265
1266 /*
1267 * If someone has not already unmounted this file system,
1268 * drain the zrele_taskq to ensure all active references to the
1269 * zfsvfs_t have been handled only then can it be safely destroyed.
1270 */
1271 if (zfsvfs->z_os) {
1272 /*
1273 * If we're unmounting we have to wait for the list to
1274 * drain completely.
1275 *
1276 * If we're not unmounting there's no guarantee the list
1277 * will drain completely, but iputs run from the taskq
1278 * may add the parents of dir-based xattrs to the taskq
1279 * so we want to wait for these.
1280 *
1281 * We can safely check z_all_znodes for being empty because the
1282 * VFS has already blocked operations which add to it.
1283 */
1284 int round = 0;
1285 while (!list_is_empty(&zfsvfs->z_all_znodes)) {
1286 taskq_wait_outstanding(dsl_pool_zrele_taskq(
1287 dmu_objset_pool(zfsvfs->z_os)), 0);
1288 if (++round > 1 && !unmounting)
1289 break;
1290 }
1291 }
1292
1293 ZFS_TEARDOWN_ENTER_WRITE(zfsvfs, FTAG);
1294
1295 if (!unmounting) {
1296 /*
1297 * We purge the parent filesystem's super block as the
1298 * parent filesystem and all of its snapshots have their
1299 * inode's super block set to the parent's filesystem's
1300 * super block. Note, 'z_parent' is self referential
1301 * for non-snapshots.
1302 */
1303 shrink_dcache_sb(zfsvfs->z_parent->z_sb);
1304 }
1305
1306 /*
1307 * Close the zil. NB: Can't close the zil while zfs_inactive
1308 * threads are blocked as zil_close can call zfs_inactive.
1309 */
1310 if (zfsvfs->z_log) {
1311 zil_close(zfsvfs->z_log);
1312 zfsvfs->z_log = NULL;
1313 }
1314
1315 rw_enter(&zfsvfs->z_teardown_inactive_lock, RW_WRITER);
1316
1317 /*
1318 * If we are not unmounting (ie: online recv) and someone already
1319 * unmounted this file system while we were doing the switcheroo,
1320 * or a reopen of z_os failed then just bail out now.
1321 */
1322 if (!unmounting && (zfsvfs->z_unmounted || zfsvfs->z_os == NULL)) {
1323 rw_exit(&zfsvfs->z_teardown_inactive_lock);
1324 ZFS_TEARDOWN_EXIT(zfsvfs, FTAG);
1325 return (SET_ERROR(EIO));
1326 }
1327
1328 /*
1329 * At this point there are no VFS ops active, and any new VFS ops
1330 * will fail with EIO since we have z_teardown_lock for writer (only
1331 * relevant for forced unmount).
1332 *
1333 * Release all holds on dbufs. We also grab an extra reference to all
1334 * the remaining inodes so that the kernel does not attempt to free
1335 * any inodes of a suspended fs. This can cause deadlocks since the
1336 * zfs_resume_fs() process may involve starting threads, which might
1337 * attempt to free unreferenced inodes to free up memory for the new
1338 * thread.
1339 */
1340 if (!unmounting) {
1341 mutex_enter(&zfsvfs->z_znodes_lock);
1342 for (zp = list_head(&zfsvfs->z_all_znodes); zp != NULL;
1343 zp = list_next(&zfsvfs->z_all_znodes, zp)) {
1344 if (zp->z_sa_hdl)
1345 zfs_znode_dmu_fini(zp);
1346 if (igrab(ZTOI(zp)) != NULL)
1347 zp->z_suspended = B_TRUE;
1348
1349 }
1350 mutex_exit(&zfsvfs->z_znodes_lock);
1351 }
1352
1353 /*
1354 * If we are unmounting, set the unmounted flag and let new VFS ops
1355 * unblock. zfs_inactive will have the unmounted behavior, and all
1356 * other VFS ops will fail with EIO.
1357 */
1358 if (unmounting) {
1359 zfsvfs->z_unmounted = B_TRUE;
1360 rw_exit(&zfsvfs->z_teardown_inactive_lock);
1361 ZFS_TEARDOWN_EXIT(zfsvfs, FTAG);
1362 }
1363
1364 /*
1365 * z_os will be NULL if there was an error in attempting to reopen
1366 * zfsvfs, so just return as the properties had already been
1367 *
1368 * unregistered and cached data had been evicted before.
1369 */
1370 if (zfsvfs->z_os == NULL)
1371 return (0);
1372
1373 /*
1374 * Unregister properties.
1375 */
1376 zfs_unregister_callbacks(zfsvfs);
1377
1378 /*
1379 * Evict cached data. We must write out any dirty data before
1380 * disowning the dataset.
1381 */
1382 objset_t *os = zfsvfs->z_os;
1383 boolean_t os_dirty = B_FALSE;
1384 for (int t = 0; t < TXG_SIZE; t++) {
1385 if (dmu_objset_is_dirty(os, t)) {
1386 os_dirty = B_TRUE;
1387 break;
1388 }
1389 }
1390 if (!zfs_is_readonly(zfsvfs) && os_dirty) {
1391 txg_wait_synced(dmu_objset_pool(zfsvfs->z_os), 0);
1392 }
1393 dmu_objset_evict_dbufs(zfsvfs->z_os);
1394 dsl_dir_t *dd = os->os_dsl_dataset->ds_dir;
1395 dsl_dir_cancel_waiters(dd);
1396
1397 return (0);
1398 }
1399
1400 static atomic_long_t zfs_bdi_seq = ATOMIC_LONG_INIT(0);
1401
1402 int
zfs_domount(struct super_block * sb,zfs_mnt_t * zm,int silent)1403 zfs_domount(struct super_block *sb, zfs_mnt_t *zm, int silent)
1404 {
1405 const char *osname = zm->mnt_osname;
1406 struct inode *root_inode = NULL;
1407 uint64_t recordsize;
1408 int error = 0;
1409 zfsvfs_t *zfsvfs = NULL;
1410 vfs_t *vfs = NULL;
1411 int canwrite;
1412 int dataset_visible_zone;
1413
1414 ASSERT(zm);
1415 ASSERT(osname);
1416
1417 dataset_visible_zone = zone_dataset_visible(osname, &canwrite);
1418
1419 /*
1420 * Refuse to mount a filesystem if we are in a namespace and the
1421 * dataset is not visible or writable in that namespace.
1422 */
1423 if (!INGLOBALZONE(curproc) &&
1424 (!dataset_visible_zone || !canwrite)) {
1425 return (SET_ERROR(EPERM));
1426 }
1427
1428 error = zfsvfs_parse_options(zm->mnt_data, &vfs);
1429 if (error)
1430 return (error);
1431
1432 /*
1433 * If a non-writable filesystem is being mounted without the
1434 * read-only flag, pretend it was set, as done for snapshots.
1435 */
1436 if (!canwrite)
1437 vfs->vfs_readonly = B_TRUE;
1438
1439 error = zfsvfs_create(osname, vfs->vfs_readonly, &zfsvfs);
1440 if (error) {
1441 zfsvfs_vfs_free(vfs);
1442 goto out;
1443 }
1444
1445 if ((error = dsl_prop_get_integer(osname, "recordsize",
1446 &recordsize, NULL))) {
1447 zfsvfs_vfs_free(vfs);
1448 goto out;
1449 }
1450
1451 vfs->vfs_data = zfsvfs;
1452 zfsvfs->z_vfs = vfs;
1453 zfsvfs->z_sb = sb;
1454 sb->s_fs_info = zfsvfs;
1455 sb->s_magic = ZFS_SUPER_MAGIC;
1456 sb->s_maxbytes = MAX_LFS_FILESIZE;
1457 sb->s_time_gran = 1;
1458 sb->s_blocksize = recordsize;
1459 sb->s_blocksize_bits = ilog2(recordsize);
1460
1461 error = -super_setup_bdi_name(sb, "%.28s-%ld", "zfs",
1462 atomic_long_inc_return(&zfs_bdi_seq));
1463 if (error)
1464 goto out;
1465
1466 sb->s_bdi->ra_pages = 0;
1467
1468 /* Set callback operations for the file system. */
1469 sb->s_op = &zpl_super_operations;
1470 sb->s_xattr = zpl_xattr_handlers;
1471 sb->s_export_op = &zpl_export_operations;
1472
1473 /* Set features for file system. */
1474 zfs_set_fuid_feature(zfsvfs);
1475
1476 if (dmu_objset_is_snapshot(zfsvfs->z_os)) {
1477 uint64_t pval;
1478
1479 atime_changed_cb(zfsvfs, B_FALSE);
1480 readonly_changed_cb(zfsvfs, B_TRUE);
1481 if ((error = dsl_prop_get_integer(osname,
1482 "xattr", &pval, NULL)))
1483 goto out;
1484 xattr_changed_cb(zfsvfs, pval);
1485 if ((error = dsl_prop_get_integer(osname,
1486 "acltype", &pval, NULL)))
1487 goto out;
1488 acltype_changed_cb(zfsvfs, pval);
1489 zfsvfs->z_issnap = B_TRUE;
1490 zfsvfs->z_os->os_sync = ZFS_SYNC_DISABLED;
1491 zfsvfs->z_snap_defer_time = jiffies;
1492
1493 mutex_enter(&zfsvfs->z_os->os_user_ptr_lock);
1494 dmu_objset_set_user(zfsvfs->z_os, zfsvfs);
1495 mutex_exit(&zfsvfs->z_os->os_user_ptr_lock);
1496 } else {
1497 if ((error = zfsvfs_setup(zfsvfs, B_TRUE)))
1498 goto out;
1499 }
1500
1501 /* Allocate a root inode for the filesystem. */
1502 error = zfs_root(zfsvfs, &root_inode);
1503 if (error) {
1504 (void) zfs_umount(sb);
1505 zfsvfs = NULL; /* avoid double-free; first in zfs_umount */
1506 goto out;
1507 }
1508
1509 /* Allocate a root dentry for the filesystem */
1510 sb->s_root = d_make_root(root_inode);
1511 if (sb->s_root == NULL) {
1512 (void) zfs_umount(sb);
1513 zfsvfs = NULL; /* avoid double-free; first in zfs_umount */
1514 error = SET_ERROR(ENOMEM);
1515 goto out;
1516 }
1517
1518 if (!zfsvfs->z_issnap)
1519 zfsctl_create(zfsvfs);
1520
1521 zfsvfs->z_arc_prune = arc_add_prune_callback(zpl_prune_sb, sb);
1522 out:
1523 if (error) {
1524 if (zfsvfs != NULL) {
1525 dmu_objset_disown(zfsvfs->z_os, B_TRUE, zfsvfs);
1526 zfsvfs_free(zfsvfs);
1527 }
1528 /*
1529 * make sure we don't have dangling sb->s_fs_info which
1530 * zfs_preumount will use.
1531 */
1532 sb->s_fs_info = NULL;
1533 }
1534
1535 return (error);
1536 }
1537
1538 /*
1539 * Called when an unmount is requested and certain sanity checks have
1540 * already passed. At this point no dentries or inodes have been reclaimed
1541 * from their respective caches. We drop the extra reference on the .zfs
1542 * control directory to allow everything to be reclaimed. All snapshots
1543 * must already have been unmounted to reach this point.
1544 */
1545 void
zfs_preumount(struct super_block * sb)1546 zfs_preumount(struct super_block *sb)
1547 {
1548 zfsvfs_t *zfsvfs = sb->s_fs_info;
1549
1550 /* zfsvfs is NULL when zfs_domount fails during mount */
1551 if (zfsvfs) {
1552 zfs_unlinked_drain_stop_wait(zfsvfs);
1553 zfsctl_destroy(sb->s_fs_info);
1554 /*
1555 * Wait for zrele_async before entering evict_inodes in
1556 * generic_shutdown_super. The reason we must finish before
1557 * evict_inodes is when lazytime is on, or when zfs_purgedir
1558 * calls zfs_zget, zrele would bump i_count from 0 to 1. This
1559 * would race with the i_count check in evict_inodes. This means
1560 * it could destroy the inode while we are still using it.
1561 *
1562 * We wait for two passes. xattr directories in the first pass
1563 * may add xattr entries in zfs_purgedir, so in the second pass
1564 * we wait for them. We don't use taskq_wait here because it is
1565 * a pool wide taskq. Other mounted filesystems can constantly
1566 * do zrele_async and there's no guarantee when taskq will be
1567 * empty.
1568 */
1569 taskq_wait_outstanding(dsl_pool_zrele_taskq(
1570 dmu_objset_pool(zfsvfs->z_os)), 0);
1571 taskq_wait_outstanding(dsl_pool_zrele_taskq(
1572 dmu_objset_pool(zfsvfs->z_os)), 0);
1573 }
1574 }
1575
1576 /*
1577 * Called once all other unmount released tear down has occurred.
1578 * It is our responsibility to release any remaining infrastructure.
1579 */
1580 int
zfs_umount(struct super_block * sb)1581 zfs_umount(struct super_block *sb)
1582 {
1583 zfsvfs_t *zfsvfs = sb->s_fs_info;
1584 objset_t *os;
1585
1586 if (zfsvfs->z_arc_prune != NULL)
1587 arc_remove_prune_callback(zfsvfs->z_arc_prune);
1588 VERIFY(zfsvfs_teardown(zfsvfs, B_TRUE) == 0);
1589 os = zfsvfs->z_os;
1590
1591 /*
1592 * z_os will be NULL if there was an error in
1593 * attempting to reopen zfsvfs.
1594 */
1595 if (os != NULL) {
1596 /*
1597 * Unset the objset user_ptr.
1598 */
1599 mutex_enter(&os->os_user_ptr_lock);
1600 dmu_objset_set_user(os, NULL);
1601 mutex_exit(&os->os_user_ptr_lock);
1602
1603 /*
1604 * Finally release the objset
1605 */
1606 dmu_objset_disown(os, B_TRUE, zfsvfs);
1607 }
1608
1609 zfsvfs_free(zfsvfs);
1610 sb->s_fs_info = NULL;
1611 return (0);
1612 }
1613
1614 int
zfs_remount(struct super_block * sb,int * flags,zfs_mnt_t * zm)1615 zfs_remount(struct super_block *sb, int *flags, zfs_mnt_t *zm)
1616 {
1617 zfsvfs_t *zfsvfs = sb->s_fs_info;
1618 vfs_t *vfsp;
1619 boolean_t issnap = dmu_objset_is_snapshot(zfsvfs->z_os);
1620 int error;
1621
1622 if ((issnap || !spa_writeable(dmu_objset_spa(zfsvfs->z_os))) &&
1623 !(*flags & SB_RDONLY)) {
1624 *flags |= SB_RDONLY;
1625 return (EROFS);
1626 }
1627
1628 error = zfsvfs_parse_options(zm->mnt_data, &vfsp);
1629 if (error)
1630 return (error);
1631
1632 if (!zfs_is_readonly(zfsvfs) && (*flags & SB_RDONLY))
1633 txg_wait_synced(dmu_objset_pool(zfsvfs->z_os), 0);
1634
1635 zfs_unregister_callbacks(zfsvfs);
1636 zfsvfs_vfs_free(zfsvfs->z_vfs);
1637
1638 vfsp->vfs_data = zfsvfs;
1639 zfsvfs->z_vfs = vfsp;
1640 if (!issnap)
1641 (void) zfs_register_callbacks(vfsp);
1642
1643 return (error);
1644 }
1645
1646 int
zfs_vget(struct super_block * sb,struct inode ** ipp,fid_t * fidp)1647 zfs_vget(struct super_block *sb, struct inode **ipp, fid_t *fidp)
1648 {
1649 zfsvfs_t *zfsvfs = sb->s_fs_info;
1650 znode_t *zp;
1651 uint64_t object = 0;
1652 uint64_t fid_gen = 0;
1653 uint64_t gen_mask;
1654 uint64_t zp_gen;
1655 int i, err;
1656
1657 *ipp = NULL;
1658
1659 if (fidp->fid_len == SHORT_FID_LEN || fidp->fid_len == LONG_FID_LEN) {
1660 zfid_short_t *zfid = (zfid_short_t *)fidp;
1661
1662 for (i = 0; i < sizeof (zfid->zf_object); i++)
1663 object |= ((uint64_t)zfid->zf_object[i]) << (8 * i);
1664
1665 for (i = 0; i < sizeof (zfid->zf_gen); i++)
1666 fid_gen |= ((uint64_t)zfid->zf_gen[i]) << (8 * i);
1667 } else {
1668 return (SET_ERROR(EINVAL));
1669 }
1670
1671 /* LONG_FID_LEN means snapdirs */
1672 if (fidp->fid_len == LONG_FID_LEN) {
1673 zfid_long_t *zlfid = (zfid_long_t *)fidp;
1674 uint64_t objsetid = 0;
1675 uint64_t setgen = 0;
1676
1677 for (i = 0; i < sizeof (zlfid->zf_setid); i++)
1678 objsetid |= ((uint64_t)zlfid->zf_setid[i]) << (8 * i);
1679
1680 for (i = 0; i < sizeof (zlfid->zf_setgen); i++)
1681 setgen |= ((uint64_t)zlfid->zf_setgen[i]) << (8 * i);
1682
1683 if (objsetid != ZFSCTL_INO_SNAPDIRS - object) {
1684 dprintf("snapdir fid: objsetid (%llu) != "
1685 "ZFSCTL_INO_SNAPDIRS (%llu) - object (%llu)\n",
1686 objsetid, ZFSCTL_INO_SNAPDIRS, object);
1687
1688 return (SET_ERROR(EINVAL));
1689 }
1690
1691 if (fid_gen > 1 || setgen != 0) {
1692 dprintf("snapdir fid: fid_gen (%llu) and setgen "
1693 "(%llu)\n", fid_gen, setgen);
1694 return (SET_ERROR(EINVAL));
1695 }
1696
1697 return (zfsctl_snapdir_vget(sb, objsetid, fid_gen, ipp));
1698 }
1699
1700 if ((err = zfs_enter(zfsvfs, FTAG)) != 0)
1701 return (err);
1702 /* A zero fid_gen means we are in the .zfs control directories */
1703 if (fid_gen == 0 &&
1704 (object == ZFSCTL_INO_ROOT || object == ZFSCTL_INO_SNAPDIR)) {
1705 *ipp = zfsvfs->z_ctldir;
1706 ASSERT(*ipp != NULL);
1707
1708 if (zfsvfs->z_show_ctldir == ZFS_SNAPDIR_DISABLED) {
1709 return (SET_ERROR(ENOENT));
1710 }
1711
1712 if (object == ZFSCTL_INO_SNAPDIR) {
1713 VERIFY(zfsctl_root_lookup(*ipp, "snapshot", ipp,
1714 0, kcred, NULL, NULL) == 0);
1715 } else {
1716 /*
1717 * Must have an existing ref, so igrab()
1718 * cannot return NULL
1719 */
1720 VERIFY3P(igrab(*ipp), !=, NULL);
1721 }
1722 zfs_exit(zfsvfs, FTAG);
1723 return (0);
1724 }
1725
1726 gen_mask = -1ULL >> (64 - 8 * i);
1727
1728 dprintf("getting %llu [%llu mask %llx]\n", object, fid_gen, gen_mask);
1729 if ((err = zfs_zget(zfsvfs, object, &zp))) {
1730 zfs_exit(zfsvfs, FTAG);
1731 return (err);
1732 }
1733
1734 /* Don't export xattr stuff */
1735 if (zp->z_pflags & ZFS_XATTR) {
1736 zrele(zp);
1737 zfs_exit(zfsvfs, FTAG);
1738 return (SET_ERROR(ENOENT));
1739 }
1740
1741 (void) sa_lookup(zp->z_sa_hdl, SA_ZPL_GEN(zfsvfs), &zp_gen,
1742 sizeof (uint64_t));
1743 zp_gen = zp_gen & gen_mask;
1744 if (zp_gen == 0)
1745 zp_gen = 1;
1746 if ((fid_gen == 0) && (zfsvfs->z_root == object))
1747 fid_gen = zp_gen;
1748 if (zp->z_unlinked || zp_gen != fid_gen) {
1749 dprintf("znode gen (%llu) != fid gen (%llu)\n", zp_gen,
1750 fid_gen);
1751 zrele(zp);
1752 zfs_exit(zfsvfs, FTAG);
1753 return (SET_ERROR(ENOENT));
1754 }
1755
1756 *ipp = ZTOI(zp);
1757 if (*ipp)
1758 zfs_znode_update_vfs(ITOZ(*ipp));
1759
1760 zfs_exit(zfsvfs, FTAG);
1761 return (0);
1762 }
1763
1764 /*
1765 * Block out VFS ops and close zfsvfs_t
1766 *
1767 * Note, if successful, then we return with the 'z_teardown_lock' and
1768 * 'z_teardown_inactive_lock' write held. We leave ownership of the underlying
1769 * dataset and objset intact so that they can be atomically handed off during
1770 * a subsequent rollback or recv operation and the resume thereafter.
1771 */
1772 int
zfs_suspend_fs(zfsvfs_t * zfsvfs)1773 zfs_suspend_fs(zfsvfs_t *zfsvfs)
1774 {
1775 int error;
1776
1777 if ((error = zfsvfs_teardown(zfsvfs, B_FALSE)) != 0)
1778 return (error);
1779
1780 return (0);
1781 }
1782
1783 /*
1784 * Rebuild SA and release VOPs. Note that ownership of the underlying dataset
1785 * is an invariant across any of the operations that can be performed while the
1786 * filesystem was suspended. Whether it succeeded or failed, the preconditions
1787 * are the same: the relevant objset and associated dataset are owned by
1788 * zfsvfs, held, and long held on entry.
1789 */
1790 int
zfs_resume_fs(zfsvfs_t * zfsvfs,dsl_dataset_t * ds)1791 zfs_resume_fs(zfsvfs_t *zfsvfs, dsl_dataset_t *ds)
1792 {
1793 int err, err2;
1794 znode_t *zp;
1795
1796 ASSERT(ZFS_TEARDOWN_WRITE_HELD(zfsvfs));
1797 ASSERT(RW_WRITE_HELD(&zfsvfs->z_teardown_inactive_lock));
1798
1799 /*
1800 * We already own this, so just update the objset_t, as the one we
1801 * had before may have been evicted.
1802 */
1803 objset_t *os;
1804 VERIFY3P(ds->ds_owner, ==, zfsvfs);
1805 VERIFY(dsl_dataset_long_held(ds));
1806 dsl_pool_t *dp = spa_get_dsl(dsl_dataset_get_spa(ds));
1807 dsl_pool_config_enter(dp, FTAG);
1808 VERIFY0(dmu_objset_from_ds(ds, &os));
1809 dsl_pool_config_exit(dp, FTAG);
1810
1811 err = zfsvfs_init(zfsvfs, os);
1812 if (err != 0)
1813 goto bail;
1814
1815 ds->ds_dir->dd_activity_cancelled = B_FALSE;
1816 VERIFY(zfsvfs_setup(zfsvfs, B_FALSE) == 0);
1817
1818 zfs_set_fuid_feature(zfsvfs);
1819 zfsvfs->z_rollback_time = jiffies;
1820
1821 /*
1822 * Attempt to re-establish all the active inodes with their
1823 * dbufs. If a zfs_rezget() fails, then we unhash the inode
1824 * and mark it stale. This prevents a collision if a new
1825 * inode/object is created which must use the same inode
1826 * number. The stale inode will be be released when the
1827 * VFS prunes the dentry holding the remaining references
1828 * on the stale inode.
1829 */
1830 mutex_enter(&zfsvfs->z_znodes_lock);
1831 for (zp = list_head(&zfsvfs->z_all_znodes); zp;
1832 zp = list_next(&zfsvfs->z_all_znodes, zp)) {
1833 err2 = zfs_rezget(zp);
1834 if (err2) {
1835 zpl_d_drop_aliases(ZTOI(zp));
1836 remove_inode_hash(ZTOI(zp));
1837 }
1838
1839 /* see comment in zfs_suspend_fs() */
1840 if (zp->z_suspended) {
1841 zfs_zrele_async(zp);
1842 zp->z_suspended = B_FALSE;
1843 }
1844 }
1845 mutex_exit(&zfsvfs->z_znodes_lock);
1846
1847 if (!zfs_is_readonly(zfsvfs) && !zfsvfs->z_unmounted) {
1848 /*
1849 * zfs_suspend_fs() could have interrupted freeing
1850 * of dnodes. We need to restart this freeing so
1851 * that we don't "leak" the space.
1852 */
1853 zfs_unlinked_drain(zfsvfs);
1854 }
1855
1856 /*
1857 * Most of the time zfs_suspend_fs is used for changing the contents
1858 * of the underlying dataset. ZFS rollback and receive operations
1859 * might create files for which negative dentries are present in
1860 * the cache. Since walking the dcache would require a lot of GPL-only
1861 * code duplication, it's much easier on these rather rare occasions
1862 * just to flush the whole dcache for the given dataset/filesystem.
1863 */
1864 shrink_dcache_sb(zfsvfs->z_sb);
1865
1866 bail:
1867 if (err != 0)
1868 zfsvfs->z_unmounted = B_TRUE;
1869
1870 /* release the VFS ops */
1871 rw_exit(&zfsvfs->z_teardown_inactive_lock);
1872 ZFS_TEARDOWN_EXIT(zfsvfs, FTAG);
1873
1874 if (err != 0) {
1875 /*
1876 * Since we couldn't setup the sa framework, try to force
1877 * unmount this file system.
1878 */
1879 if (zfsvfs->z_os)
1880 (void) zfs_umount(zfsvfs->z_sb);
1881 }
1882 return (err);
1883 }
1884
1885 /*
1886 * Release VOPs and unmount a suspended filesystem.
1887 */
1888 int
zfs_end_fs(zfsvfs_t * zfsvfs,dsl_dataset_t * ds)1889 zfs_end_fs(zfsvfs_t *zfsvfs, dsl_dataset_t *ds)
1890 {
1891 ASSERT(ZFS_TEARDOWN_WRITE_HELD(zfsvfs));
1892 ASSERT(RW_WRITE_HELD(&zfsvfs->z_teardown_inactive_lock));
1893
1894 /*
1895 * We already own this, so just hold and rele it to update the
1896 * objset_t, as the one we had before may have been evicted.
1897 */
1898 objset_t *os;
1899 VERIFY3P(ds->ds_owner, ==, zfsvfs);
1900 VERIFY(dsl_dataset_long_held(ds));
1901 dsl_pool_t *dp = spa_get_dsl(dsl_dataset_get_spa(ds));
1902 dsl_pool_config_enter(dp, FTAG);
1903 VERIFY0(dmu_objset_from_ds(ds, &os));
1904 dsl_pool_config_exit(dp, FTAG);
1905 zfsvfs->z_os = os;
1906
1907 /* release the VOPs */
1908 rw_exit(&zfsvfs->z_teardown_inactive_lock);
1909 ZFS_TEARDOWN_EXIT(zfsvfs, FTAG);
1910
1911 /*
1912 * Try to force unmount this file system.
1913 */
1914 (void) zfs_umount(zfsvfs->z_sb);
1915 zfsvfs->z_unmounted = B_TRUE;
1916 return (0);
1917 }
1918
1919 /*
1920 * Automounted snapshots rely on periodic revalidation
1921 * to defer snapshots from being automatically unmounted.
1922 */
1923
1924 inline void
zfs_exit_fs(zfsvfs_t * zfsvfs)1925 zfs_exit_fs(zfsvfs_t *zfsvfs)
1926 {
1927 if (!zfsvfs->z_issnap)
1928 return;
1929
1930 if (time_after(jiffies, zfsvfs->z_snap_defer_time +
1931 MAX(zfs_expire_snapshot * HZ / 2, HZ))) {
1932 zfsvfs->z_snap_defer_time = jiffies;
1933 zfsctl_snapshot_unmount_delay(zfsvfs->z_os->os_spa,
1934 dmu_objset_id(zfsvfs->z_os),
1935 zfs_expire_snapshot);
1936 }
1937 }
1938
1939 int
zfs_set_version(zfsvfs_t * zfsvfs,uint64_t newvers)1940 zfs_set_version(zfsvfs_t *zfsvfs, uint64_t newvers)
1941 {
1942 int error;
1943 objset_t *os = zfsvfs->z_os;
1944 dmu_tx_t *tx;
1945
1946 if (newvers < ZPL_VERSION_INITIAL || newvers > ZPL_VERSION)
1947 return (SET_ERROR(EINVAL));
1948
1949 if (newvers < zfsvfs->z_version)
1950 return (SET_ERROR(EINVAL));
1951
1952 if (zfs_spa_version_map(newvers) >
1953 spa_version(dmu_objset_spa(zfsvfs->z_os)))
1954 return (SET_ERROR(ENOTSUP));
1955
1956 tx = dmu_tx_create(os);
1957 dmu_tx_hold_zap(tx, MASTER_NODE_OBJ, B_FALSE, ZPL_VERSION_STR);
1958 if (newvers >= ZPL_VERSION_SA && !zfsvfs->z_use_sa) {
1959 dmu_tx_hold_zap(tx, MASTER_NODE_OBJ, B_TRUE,
1960 ZFS_SA_ATTRS);
1961 dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, FALSE, NULL);
1962 }
1963 error = dmu_tx_assign(tx, TXG_WAIT);
1964 if (error) {
1965 dmu_tx_abort(tx);
1966 return (error);
1967 }
1968
1969 error = zap_update(os, MASTER_NODE_OBJ, ZPL_VERSION_STR,
1970 8, 1, &newvers, tx);
1971
1972 if (error) {
1973 dmu_tx_commit(tx);
1974 return (error);
1975 }
1976
1977 if (newvers >= ZPL_VERSION_SA && !zfsvfs->z_use_sa) {
1978 uint64_t sa_obj;
1979
1980 ASSERT3U(spa_version(dmu_objset_spa(zfsvfs->z_os)), >=,
1981 SPA_VERSION_SA);
1982 sa_obj = zap_create(os, DMU_OT_SA_MASTER_NODE,
1983 DMU_OT_NONE, 0, tx);
1984
1985 error = zap_add(os, MASTER_NODE_OBJ,
1986 ZFS_SA_ATTRS, 8, 1, &sa_obj, tx);
1987 ASSERT0(error);
1988
1989 VERIFY(0 == sa_set_sa_object(os, sa_obj));
1990 sa_register_update_callback(os, zfs_sa_upgrade);
1991 }
1992
1993 spa_history_log_internal_ds(dmu_objset_ds(os), "upgrade", tx,
1994 "from %llu to %llu", zfsvfs->z_version, newvers);
1995
1996 dmu_tx_commit(tx);
1997
1998 zfsvfs->z_version = newvers;
1999 os->os_version = newvers;
2000
2001 zfs_set_fuid_feature(zfsvfs);
2002
2003 return (0);
2004 }
2005
2006 /*
2007 * Return true if the corresponding vfs's unmounted flag is set.
2008 * Otherwise return false.
2009 * If this function returns true we know VFS unmount has been initiated.
2010 */
2011 boolean_t
zfs_get_vfs_flag_unmounted(objset_t * os)2012 zfs_get_vfs_flag_unmounted(objset_t *os)
2013 {
2014 zfsvfs_t *zfvp;
2015 boolean_t unmounted = B_FALSE;
2016
2017 ASSERT(dmu_objset_type(os) == DMU_OST_ZFS);
2018
2019 mutex_enter(&os->os_user_ptr_lock);
2020 zfvp = dmu_objset_get_user(os);
2021 if (zfvp != NULL && zfvp->z_unmounted)
2022 unmounted = B_TRUE;
2023 mutex_exit(&os->os_user_ptr_lock);
2024
2025 return (unmounted);
2026 }
2027
2028 void
zfsvfs_update_fromname(const char * oldname,const char * newname)2029 zfsvfs_update_fromname(const char *oldname, const char *newname)
2030 {
2031 /*
2032 * We don't need to do anything here, the devname is always current by
2033 * virtue of zfsvfs->z_sb->s_op->show_devname.
2034 */
2035 (void) oldname, (void) newname;
2036 }
2037
2038 void
zfs_init(void)2039 zfs_init(void)
2040 {
2041 zfsctl_init();
2042 zfs_znode_init();
2043 dmu_objset_register_type(DMU_OST_ZFS, zpl_get_file_info);
2044 register_filesystem(&zpl_fs_type);
2045 }
2046
2047 void
zfs_fini(void)2048 zfs_fini(void)
2049 {
2050 /*
2051 * we don't use outstanding because zpl_posix_acl_free might add more.
2052 */
2053 taskq_wait(system_delay_taskq);
2054 taskq_wait(system_taskq);
2055 unregister_filesystem(&zpl_fs_type);
2056 zfs_znode_fini();
2057 zfsctl_fini();
2058 }
2059
2060 #if defined(_KERNEL)
2061 EXPORT_SYMBOL(zfs_suspend_fs);
2062 EXPORT_SYMBOL(zfs_resume_fs);
2063 EXPORT_SYMBOL(zfs_set_version);
2064 EXPORT_SYMBOL(zfsvfs_create);
2065 EXPORT_SYMBOL(zfsvfs_free);
2066 EXPORT_SYMBOL(zfs_is_readonly);
2067 EXPORT_SYMBOL(zfs_domount);
2068 EXPORT_SYMBOL(zfs_preumount);
2069 EXPORT_SYMBOL(zfs_umount);
2070 EXPORT_SYMBOL(zfs_remount);
2071 EXPORT_SYMBOL(zfs_statvfs);
2072 EXPORT_SYMBOL(zfs_vget);
2073 EXPORT_SYMBOL(zfs_prune);
2074 #endif
2075