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87d546d8 TG |
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) 2011 Lawrence Livermore National Security, LLC. | |
23 | * Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER). | |
24 | * LLNL-CODE-403049. | |
25 | * Rewritten for Linux by: | |
26 | * Rohan Puri <rohan.puri15@gmail.com> | |
27 | * Brian Behlendorf <behlendorf1@llnl.gov> | |
28 | */ | |
29 | ||
30 | #include <sys/zfs_vfsops.h> | |
31 | #include <sys/zfs_vnops.h> | |
32 | #include <sys/zfs_znode.h> | |
33 | #include <sys/zfs_ctldir.h> | |
34 | #include <sys/zpl.h> | |
35 | ||
36 | /* | |
37 | * Common open routine. Disallow any write access. | |
38 | */ | |
39 | /* ARGSUSED */ | |
40 | static int | |
41 | zpl_common_open(struct inode *ip, struct file *filp) | |
42 | { | |
43 | if (filp->f_mode & FMODE_WRITE) | |
44 | return (-EACCES); | |
45 | ||
46 | return (generic_file_open(ip, filp)); | |
47 | } | |
48 | ||
49 | /* | |
50 | * Get root directory contents. | |
51 | */ | |
52 | static int | |
53 | zpl_root_iterate(struct file *filp, struct dir_context *ctx) | |
54 | { | |
55 | zfs_sb_t *zsb = ITOZSB(filp->f_path.dentry->d_inode); | |
56 | int error = 0; | |
57 | ||
58 | ZFS_ENTER(zsb); | |
59 | ||
60 | if (!dir_emit_dots(filp, ctx)) | |
61 | goto out; | |
62 | ||
63 | if (ctx->pos == 2) { | |
64 | if (!dir_emit(ctx, ZFS_SNAPDIR_NAME, strlen(ZFS_SNAPDIR_NAME), | |
65 | ZFSCTL_INO_SNAPDIR, DT_DIR)) | |
66 | goto out; | |
67 | ||
68 | ctx->pos++; | |
69 | } | |
70 | ||
71 | if (ctx->pos == 3) { | |
72 | if (!dir_emit(ctx, ZFS_SHAREDIR_NAME, strlen(ZFS_SHAREDIR_NAME), | |
73 | ZFSCTL_INO_SHARES, DT_DIR)) | |
74 | goto out; | |
75 | ||
76 | ctx->pos++; | |
77 | } | |
78 | out: | |
79 | ZFS_EXIT(zsb); | |
80 | ||
81 | return (error); | |
82 | } | |
83 | ||
84 | #if !defined(HAVE_VFS_ITERATE) && !defined(HAVE_VFS_ITERATE_SHARED) | |
85 | static int | |
86 | zpl_root_readdir(struct file *filp, void *dirent, filldir_t filldir) | |
87 | { | |
88 | struct dir_context ctx = DIR_CONTEXT_INIT(dirent, filldir, filp->f_pos); | |
89 | int error; | |
90 | ||
91 | error = zpl_root_iterate(filp, &ctx); | |
92 | filp->f_pos = ctx.pos; | |
93 | ||
94 | return (error); | |
95 | } | |
96 | #endif /* HAVE_VFS_ITERATE */ | |
97 | ||
98 | /* | |
99 | * Get root directory attributes. | |
100 | */ | |
101 | /* ARGSUSED */ | |
102 | static int | |
3e990ae0 CIK |
103 | zpl_root_getattr_impl(const struct path *path, struct kstat *stat, |
104 | u32 request_mask, unsigned int query_flags) | |
87d546d8 | 105 | { |
3e990ae0 | 106 | generic_fillattr(path->dentry->d_inode, stat); |
87d546d8 TG |
107 | stat->atime = CURRENT_TIME; |
108 | ||
3e990ae0 | 109 | return (0); |
87d546d8 | 110 | } |
3e990ae0 | 111 | ZPL_GETATTR_WRAPPER(zpl_root_getattr); |
87d546d8 TG |
112 | |
113 | static struct dentry * | |
114 | #ifdef HAVE_LOOKUP_NAMEIDATA | |
115 | zpl_root_lookup(struct inode *dip, struct dentry *dentry, struct nameidata *nd) | |
116 | #else | |
117 | zpl_root_lookup(struct inode *dip, struct dentry *dentry, unsigned int flags) | |
118 | #endif | |
119 | { | |
120 | cred_t *cr = CRED(); | |
121 | struct inode *ip; | |
122 | int error; | |
123 | ||
124 | crhold(cr); | |
125 | error = -zfsctl_root_lookup(dip, dname(dentry), &ip, 0, cr, NULL, NULL); | |
126 | ASSERT3S(error, <=, 0); | |
127 | crfree(cr); | |
128 | ||
129 | if (error) { | |
130 | if (error == -ENOENT) | |
131 | return (d_splice_alias(NULL, dentry)); | |
132 | else | |
133 | return (ERR_PTR(error)); | |
134 | } | |
135 | ||
136 | return (d_splice_alias(ip, dentry)); | |
137 | } | |
138 | ||
139 | /* | |
140 | * The '.zfs' control directory file and inode operations. | |
141 | */ | |
142 | const struct file_operations zpl_fops_root = { | |
143 | .open = zpl_common_open, | |
144 | .llseek = generic_file_llseek, | |
145 | .read = generic_read_dir, | |
146 | #ifdef HAVE_VFS_ITERATE_SHARED | |
147 | .iterate_shared = zpl_root_iterate, | |
148 | #elif defined(HAVE_VFS_ITERATE) | |
149 | .iterate = zpl_root_iterate, | |
150 | #else | |
151 | .readdir = zpl_root_readdir, | |
152 | #endif | |
153 | }; | |
154 | ||
155 | const struct inode_operations zpl_ops_root = { | |
156 | .lookup = zpl_root_lookup, | |
157 | .getattr = zpl_root_getattr, | |
158 | }; | |
159 | ||
160 | #ifdef HAVE_AUTOMOUNT | |
161 | static struct vfsmount * | |
162 | zpl_snapdir_automount(struct path *path) | |
163 | { | |
164 | int error; | |
165 | ||
166 | error = -zfsctl_snapshot_mount(path, 0); | |
167 | if (error) | |
168 | return (ERR_PTR(error)); | |
169 | ||
170 | /* | |
171 | * Rather than returning the new vfsmount for the snapshot we must | |
172 | * return NULL to indicate a mount collision. This is done because | |
173 | * the user space mount calls do_add_mount() which adds the vfsmount | |
174 | * to the name space. If we returned the new mount here it would be | |
175 | * added again to the vfsmount list resulting in list corruption. | |
176 | */ | |
177 | return (NULL); | |
178 | } | |
179 | #endif /* HAVE_AUTOMOUNT */ | |
180 | ||
181 | /* | |
182 | * Negative dentries must always be revalidated so newly created snapshots | |
183 | * can be detected and automounted. Normal dentries should be kept because | |
184 | * as of the 3.18 kernel revaliding the mountpoint dentry will result in | |
185 | * the snapshot being immediately unmounted. | |
186 | */ | |
187 | static int | |
188 | #ifdef HAVE_D_REVALIDATE_NAMEIDATA | |
189 | zpl_snapdir_revalidate(struct dentry *dentry, struct nameidata *i) | |
190 | #else | |
191 | zpl_snapdir_revalidate(struct dentry *dentry, unsigned int flags) | |
192 | #endif | |
193 | { | |
194 | return (!!dentry->d_inode); | |
195 | } | |
196 | ||
197 | dentry_operations_t zpl_dops_snapdirs = { | |
198 | /* | |
199 | * Auto mounting of snapshots is only supported for 2.6.37 and | |
200 | * newer kernels. Prior to this kernel the ops->follow_link() | |
201 | * callback was used as a hack to trigger the mount. The | |
202 | * resulting vfsmount was then explicitly grafted in to the | |
203 | * name space. While it might be possible to add compatibility | |
204 | * code to accomplish this it would require considerable care. | |
205 | */ | |
206 | #ifdef HAVE_AUTOMOUNT | |
207 | .d_automount = zpl_snapdir_automount, | |
208 | #endif /* HAVE_AUTOMOUNT */ | |
209 | .d_revalidate = zpl_snapdir_revalidate, | |
210 | }; | |
211 | ||
212 | static struct dentry * | |
213 | #ifdef HAVE_LOOKUP_NAMEIDATA | |
214 | zpl_snapdir_lookup(struct inode *dip, struct dentry *dentry, | |
215 | struct nameidata *nd) | |
216 | #else | |
217 | zpl_snapdir_lookup(struct inode *dip, struct dentry *dentry, | |
218 | unsigned int flags) | |
219 | #endif | |
220 | ||
221 | { | |
222 | fstrans_cookie_t cookie; | |
223 | cred_t *cr = CRED(); | |
224 | struct inode *ip = NULL; | |
225 | int error; | |
226 | ||
227 | crhold(cr); | |
228 | cookie = spl_fstrans_mark(); | |
229 | error = -zfsctl_snapdir_lookup(dip, dname(dentry), &ip, | |
230 | 0, cr, NULL, NULL); | |
231 | ASSERT3S(error, <=, 0); | |
232 | spl_fstrans_unmark(cookie); | |
233 | crfree(cr); | |
234 | ||
235 | if (error && error != -ENOENT) | |
236 | return (ERR_PTR(error)); | |
237 | ||
238 | ASSERT(error == 0 || ip == NULL); | |
239 | d_clear_d_op(dentry); | |
240 | d_set_d_op(dentry, &zpl_dops_snapdirs); | |
241 | #ifdef HAVE_AUTOMOUNT | |
242 | dentry->d_flags |= DCACHE_NEED_AUTOMOUNT; | |
243 | #endif | |
244 | ||
245 | return (d_splice_alias(ip, dentry)); | |
246 | } | |
247 | ||
248 | static int | |
249 | zpl_snapdir_iterate(struct file *filp, struct dir_context *ctx) | |
250 | { | |
251 | zfs_sb_t *zsb = ITOZSB(filp->f_path.dentry->d_inode); | |
252 | fstrans_cookie_t cookie; | |
253 | char snapname[MAXNAMELEN]; | |
254 | boolean_t case_conflict; | |
255 | uint64_t id, pos; | |
256 | int error = 0; | |
257 | ||
258 | ZFS_ENTER(zsb); | |
259 | cookie = spl_fstrans_mark(); | |
260 | ||
261 | if (!dir_emit_dots(filp, ctx)) | |
262 | goto out; | |
263 | ||
264 | pos = ctx->pos; | |
265 | while (error == 0) { | |
266 | dsl_pool_config_enter(dmu_objset_pool(zsb->z_os), FTAG); | |
267 | error = -dmu_snapshot_list_next(zsb->z_os, MAXNAMELEN, | |
268 | snapname, &id, &pos, &case_conflict); | |
269 | dsl_pool_config_exit(dmu_objset_pool(zsb->z_os), FTAG); | |
270 | if (error) | |
271 | goto out; | |
272 | ||
273 | if (!dir_emit(ctx, snapname, strlen(snapname), | |
274 | ZFSCTL_INO_SHARES - id, DT_DIR)) | |
275 | goto out; | |
276 | ||
277 | ctx->pos = pos; | |
278 | } | |
279 | out: | |
280 | spl_fstrans_unmark(cookie); | |
281 | ZFS_EXIT(zsb); | |
282 | ||
283 | if (error == -ENOENT) | |
284 | return (0); | |
285 | ||
286 | return (error); | |
287 | } | |
288 | ||
289 | #if !defined(HAVE_VFS_ITERATE) && !defined(HAVE_VFS_ITERATE_SHARED) | |
290 | static int | |
291 | zpl_snapdir_readdir(struct file *filp, void *dirent, filldir_t filldir) | |
292 | { | |
293 | struct dir_context ctx = DIR_CONTEXT_INIT(dirent, filldir, filp->f_pos); | |
294 | int error; | |
295 | ||
296 | error = zpl_snapdir_iterate(filp, &ctx); | |
297 | filp->f_pos = ctx.pos; | |
298 | ||
299 | return (error); | |
300 | } | |
301 | #endif /* HAVE_VFS_ITERATE */ | |
302 | ||
303 | static int | |
304 | zpl_snapdir_rename2(struct inode *sdip, struct dentry *sdentry, | |
305 | struct inode *tdip, struct dentry *tdentry, unsigned int flags) | |
306 | { | |
307 | cred_t *cr = CRED(); | |
308 | int error; | |
309 | ||
310 | /* We probably don't want to support renameat2(2) in ctldir */ | |
311 | if (flags) | |
312 | return (-EINVAL); | |
313 | ||
314 | crhold(cr); | |
315 | error = -zfsctl_snapdir_rename(sdip, dname(sdentry), | |
316 | tdip, dname(tdentry), cr, 0); | |
317 | ASSERT3S(error, <=, 0); | |
318 | crfree(cr); | |
319 | ||
320 | return (error); | |
321 | } | |
322 | ||
323 | #ifndef HAVE_RENAME_WANTS_FLAGS | |
324 | static int | |
325 | zpl_snapdir_rename(struct inode *sdip, struct dentry *sdentry, | |
326 | struct inode *tdip, struct dentry *tdentry) | |
327 | { | |
328 | return (zpl_snapdir_rename2(sdip, sdentry, tdip, tdentry, 0)); | |
329 | } | |
330 | #endif | |
331 | ||
332 | static int | |
333 | zpl_snapdir_rmdir(struct inode *dip, struct dentry *dentry) | |
334 | { | |
335 | cred_t *cr = CRED(); | |
336 | int error; | |
337 | ||
338 | crhold(cr); | |
339 | error = -zfsctl_snapdir_remove(dip, dname(dentry), cr, 0); | |
340 | ASSERT3S(error, <=, 0); | |
341 | crfree(cr); | |
342 | ||
343 | return (error); | |
344 | } | |
345 | ||
346 | static int | |
347 | zpl_snapdir_mkdir(struct inode *dip, struct dentry *dentry, zpl_umode_t mode) | |
348 | { | |
349 | cred_t *cr = CRED(); | |
350 | vattr_t *vap; | |
351 | struct inode *ip; | |
352 | int error; | |
353 | ||
354 | crhold(cr); | |
355 | vap = kmem_zalloc(sizeof (vattr_t), KM_SLEEP); | |
356 | zpl_vap_init(vap, dip, mode | S_IFDIR, cr); | |
357 | ||
358 | error = -zfsctl_snapdir_mkdir(dip, dname(dentry), vap, &ip, cr, 0); | |
359 | if (error == 0) { | |
360 | d_clear_d_op(dentry); | |
361 | d_set_d_op(dentry, &zpl_dops_snapdirs); | |
362 | d_instantiate(dentry, ip); | |
363 | } | |
364 | ||
365 | kmem_free(vap, sizeof (vattr_t)); | |
366 | ASSERT3S(error, <=, 0); | |
367 | crfree(cr); | |
368 | ||
369 | return (error); | |
370 | } | |
371 | ||
372 | /* | |
373 | * Get snapshot directory attributes. | |
374 | */ | |
375 | /* ARGSUSED */ | |
376 | static int | |
3e990ae0 CIK |
377 | zpl_snapdir_getattr_impl(const struct path *path, struct kstat *stat, |
378 | u32 request_mask, unsigned int query_flags) | |
87d546d8 | 379 | { |
3e990ae0 | 380 | zfs_sb_t *zsb = ITOZSB(path->dentry->d_inode); |
87d546d8 TG |
381 | |
382 | ZFS_ENTER(zsb); | |
3e990ae0 CIK |
383 | generic_fillattr(path->dentry->d_inode, stat); |
384 | ||
87d546d8 TG |
385 | stat->nlink = stat->size = 2; |
386 | stat->ctime = stat->mtime = dmu_objset_snap_cmtime(zsb->z_os); | |
387 | stat->atime = CURRENT_TIME; | |
388 | ZFS_EXIT(zsb); | |
389 | ||
3e990ae0 | 390 | return (0); |
87d546d8 | 391 | } |
3e990ae0 | 392 | ZPL_GETATTR_WRAPPER(zpl_snapdir_getattr); |
87d546d8 TG |
393 | |
394 | /* | |
395 | * The '.zfs/snapshot' directory file operations. These mainly control | |
396 | * generating the list of available snapshots when doing an 'ls' in the | |
397 | * directory. See zpl_snapdir_readdir(). | |
398 | */ | |
399 | const struct file_operations zpl_fops_snapdir = { | |
400 | .open = zpl_common_open, | |
401 | .llseek = generic_file_llseek, | |
402 | .read = generic_read_dir, | |
403 | #ifdef HAVE_VFS_ITERATE_SHARED | |
404 | .iterate_shared = zpl_snapdir_iterate, | |
405 | #elif defined(HAVE_VFS_ITERATE) | |
406 | .iterate = zpl_snapdir_iterate, | |
407 | #else | |
408 | .readdir = zpl_snapdir_readdir, | |
409 | #endif | |
410 | ||
411 | }; | |
412 | ||
413 | /* | |
414 | * The '.zfs/snapshot' directory inode operations. These mainly control | |
415 | * creating an inode for a snapshot directory and initializing the needed | |
416 | * infrastructure to automount the snapshot. See zpl_snapdir_lookup(). | |
417 | */ | |
418 | const struct inode_operations zpl_ops_snapdir = { | |
419 | .lookup = zpl_snapdir_lookup, | |
420 | .getattr = zpl_snapdir_getattr, | |
421 | #ifdef HAVE_RENAME_WANTS_FLAGS | |
422 | .rename = zpl_snapdir_rename2, | |
423 | #else | |
424 | .rename = zpl_snapdir_rename, | |
425 | #endif | |
426 | .rmdir = zpl_snapdir_rmdir, | |
427 | .mkdir = zpl_snapdir_mkdir, | |
428 | }; | |
429 | ||
430 | static struct dentry * | |
431 | #ifdef HAVE_LOOKUP_NAMEIDATA | |
432 | zpl_shares_lookup(struct inode *dip, struct dentry *dentry, | |
433 | struct nameidata *nd) | |
434 | #else | |
435 | zpl_shares_lookup(struct inode *dip, struct dentry *dentry, | |
436 | unsigned int flags) | |
437 | #endif | |
438 | { | |
439 | fstrans_cookie_t cookie; | |
440 | cred_t *cr = CRED(); | |
441 | struct inode *ip = NULL; | |
442 | int error; | |
443 | ||
444 | crhold(cr); | |
445 | cookie = spl_fstrans_mark(); | |
446 | error = -zfsctl_shares_lookup(dip, dname(dentry), &ip, | |
447 | 0, cr, NULL, NULL); | |
448 | ASSERT3S(error, <=, 0); | |
449 | spl_fstrans_unmark(cookie); | |
450 | crfree(cr); | |
451 | ||
452 | if (error) { | |
453 | if (error == -ENOENT) | |
454 | return (d_splice_alias(NULL, dentry)); | |
455 | else | |
456 | return (ERR_PTR(error)); | |
457 | } | |
458 | ||
459 | return (d_splice_alias(ip, dentry)); | |
460 | } | |
461 | ||
462 | static int | |
463 | zpl_shares_iterate(struct file *filp, struct dir_context *ctx) | |
464 | { | |
465 | fstrans_cookie_t cookie; | |
466 | cred_t *cr = CRED(); | |
467 | zfs_sb_t *zsb = ITOZSB(filp->f_path.dentry->d_inode); | |
468 | znode_t *dzp; | |
469 | int error = 0; | |
470 | ||
471 | ZFS_ENTER(zsb); | |
472 | cookie = spl_fstrans_mark(); | |
473 | ||
474 | if (zsb->z_shares_dir == 0) { | |
475 | dir_emit_dots(filp, ctx); | |
476 | goto out; | |
477 | } | |
478 | ||
479 | error = -zfs_zget(zsb, zsb->z_shares_dir, &dzp); | |
480 | if (error) | |
481 | goto out; | |
482 | ||
483 | crhold(cr); | |
484 | error = -zfs_readdir(ZTOI(dzp), ctx, cr); | |
485 | crfree(cr); | |
486 | ||
487 | iput(ZTOI(dzp)); | |
488 | out: | |
489 | spl_fstrans_unmark(cookie); | |
490 | ZFS_EXIT(zsb); | |
491 | ASSERT3S(error, <=, 0); | |
492 | ||
493 | return (error); | |
494 | } | |
495 | ||
496 | #if !defined(HAVE_VFS_ITERATE) && !defined(HAVE_VFS_ITERATE_SHARED) | |
497 | static int | |
498 | zpl_shares_readdir(struct file *filp, void *dirent, filldir_t filldir) | |
499 | { | |
500 | struct dir_context ctx = DIR_CONTEXT_INIT(dirent, filldir, filp->f_pos); | |
501 | int error; | |
502 | ||
503 | error = zpl_shares_iterate(filp, &ctx); | |
504 | filp->f_pos = ctx.pos; | |
505 | ||
506 | return (error); | |
507 | } | |
508 | #endif /* HAVE_VFS_ITERATE */ | |
509 | ||
510 | /* ARGSUSED */ | |
511 | static int | |
3e990ae0 CIK |
512 | zpl_shares_getattr_impl(const struct path *path, struct kstat *stat, |
513 | u32 request_mask, unsigned int query_flags) | |
87d546d8 | 514 | { |
3e990ae0 | 515 | struct inode *ip = path->dentry->d_inode; |
87d546d8 TG |
516 | zfs_sb_t *zsb = ITOZSB(ip); |
517 | znode_t *dzp; | |
518 | int error; | |
519 | ||
520 | ZFS_ENTER(zsb); | |
521 | ||
522 | if (zsb->z_shares_dir == 0) { | |
3e990ae0 | 523 | generic_fillattr(path->dentry->d_inode, stat); |
87d546d8 TG |
524 | stat->nlink = stat->size = 2; |
525 | stat->atime = CURRENT_TIME; | |
526 | ZFS_EXIT(zsb); | |
3e990ae0 | 527 | return (0); |
87d546d8 TG |
528 | } |
529 | ||
530 | error = -zfs_zget(zsb, zsb->z_shares_dir, &dzp); | |
531 | if (error == 0) { | |
532 | error = -zfs_getattr_fast(ZTOI(dzp), stat); | |
533 | iput(ZTOI(dzp)); | |
534 | } | |
535 | ||
536 | ZFS_EXIT(zsb); | |
537 | ASSERT3S(error, <=, 0); | |
538 | ||
539 | return (error); | |
540 | } | |
3e990ae0 | 541 | ZPL_GETATTR_WRAPPER(zpl_shares_getattr); |
87d546d8 TG |
542 | |
543 | /* | |
544 | * The '.zfs/shares' directory file operations. | |
545 | */ | |
546 | const struct file_operations zpl_fops_shares = { | |
547 | .open = zpl_common_open, | |
548 | .llseek = generic_file_llseek, | |
549 | .read = generic_read_dir, | |
550 | #ifdef HAVE_VFS_ITERATE_SHARED | |
551 | .iterate_shared = zpl_shares_iterate, | |
552 | #elif defined(HAVE_VFS_ITERATE) | |
553 | .iterate = zpl_shares_iterate, | |
554 | #else | |
555 | .readdir = zpl_shares_readdir, | |
556 | #endif | |
557 | ||
558 | }; | |
559 | ||
560 | /* | |
561 | * The '.zfs/shares' directory inode operations. | |
562 | */ | |
563 | const struct inode_operations zpl_ops_shares = { | |
564 | .lookup = zpl_shares_lookup, | |
565 | .getattr = zpl_shares_getattr, | |
566 | }; |