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1 | /* | |
2 | FUSE: Filesystem in Userspace | |
3 | Copyright (C) 2001-2008 Miklos Szeredi <miklos@szeredi.hu> | |
4 | ||
5 | This program can be distributed under the terms of the GNU GPL. | |
6 | See the file COPYING. | |
7 | */ | |
8 | ||
9 | #include "fuse_i.h" | |
10 | ||
11 | #include <linux/pagemap.h> | |
12 | #include <linux/file.h> | |
13 | #include <linux/sched.h> | |
14 | #include <linux/namei.h> | |
15 | #include <linux/slab.h> | |
16 | #include <linux/xattr.h> | |
17 | #include <linux/posix_acl.h> | |
18 | ||
19 | static bool fuse_use_readdirplus(struct inode *dir, struct dir_context *ctx) | |
20 | { | |
21 | struct fuse_conn *fc = get_fuse_conn(dir); | |
22 | struct fuse_inode *fi = get_fuse_inode(dir); | |
23 | ||
24 | if (!fc->do_readdirplus) | |
25 | return false; | |
26 | if (!fc->readdirplus_auto) | |
27 | return true; | |
28 | if (test_and_clear_bit(FUSE_I_ADVISE_RDPLUS, &fi->state)) | |
29 | return true; | |
30 | if (ctx->pos == 0) | |
31 | return true; | |
32 | return false; | |
33 | } | |
34 | ||
35 | static void fuse_advise_use_readdirplus(struct inode *dir) | |
36 | { | |
37 | struct fuse_inode *fi = get_fuse_inode(dir); | |
38 | ||
39 | set_bit(FUSE_I_ADVISE_RDPLUS, &fi->state); | |
40 | } | |
41 | ||
42 | union fuse_dentry { | |
43 | u64 time; | |
44 | struct rcu_head rcu; | |
45 | }; | |
46 | ||
47 | static inline void fuse_dentry_settime(struct dentry *entry, u64 time) | |
48 | { | |
49 | ((union fuse_dentry *) entry->d_fsdata)->time = time; | |
50 | } | |
51 | ||
52 | static inline u64 fuse_dentry_time(struct dentry *entry) | |
53 | { | |
54 | return ((union fuse_dentry *) entry->d_fsdata)->time; | |
55 | } | |
56 | ||
57 | /* | |
58 | * FUSE caches dentries and attributes with separate timeout. The | |
59 | * time in jiffies until the dentry/attributes are valid is stored in | |
60 | * dentry->d_fsdata and fuse_inode->i_time respectively. | |
61 | */ | |
62 | ||
63 | /* | |
64 | * Calculate the time in jiffies until a dentry/attributes are valid | |
65 | */ | |
66 | static u64 time_to_jiffies(u64 sec, u32 nsec) | |
67 | { | |
68 | if (sec || nsec) { | |
69 | struct timespec64 ts = { | |
70 | sec, | |
71 | min_t(u32, nsec, NSEC_PER_SEC - 1) | |
72 | }; | |
73 | ||
74 | return get_jiffies_64() + timespec64_to_jiffies(&ts); | |
75 | } else | |
76 | return 0; | |
77 | } | |
78 | ||
79 | /* | |
80 | * Set dentry and possibly attribute timeouts from the lookup/mk* | |
81 | * replies | |
82 | */ | |
83 | static void fuse_change_entry_timeout(struct dentry *entry, | |
84 | struct fuse_entry_out *o) | |
85 | { | |
86 | fuse_dentry_settime(entry, | |
87 | time_to_jiffies(o->entry_valid, o->entry_valid_nsec)); | |
88 | } | |
89 | ||
90 | static u64 attr_timeout(struct fuse_attr_out *o) | |
91 | { | |
92 | return time_to_jiffies(o->attr_valid, o->attr_valid_nsec); | |
93 | } | |
94 | ||
95 | static u64 entry_attr_timeout(struct fuse_entry_out *o) | |
96 | { | |
97 | return time_to_jiffies(o->attr_valid, o->attr_valid_nsec); | |
98 | } | |
99 | ||
100 | /* | |
101 | * Mark the attributes as stale, so that at the next call to | |
102 | * ->getattr() they will be fetched from userspace | |
103 | */ | |
104 | void fuse_invalidate_attr(struct inode *inode) | |
105 | { | |
106 | get_fuse_inode(inode)->i_time = 0; | |
107 | } | |
108 | ||
109 | /** | |
110 | * Mark the attributes as stale due to an atime change. Avoid the invalidate if | |
111 | * atime is not used. | |
112 | */ | |
113 | void fuse_invalidate_atime(struct inode *inode) | |
114 | { | |
115 | if (!IS_RDONLY(inode)) | |
116 | fuse_invalidate_attr(inode); | |
117 | } | |
118 | ||
119 | /* | |
120 | * Just mark the entry as stale, so that a next attempt to look it up | |
121 | * will result in a new lookup call to userspace | |
122 | * | |
123 | * This is called when a dentry is about to become negative and the | |
124 | * timeout is unknown (unlink, rmdir, rename and in some cases | |
125 | * lookup) | |
126 | */ | |
127 | void fuse_invalidate_entry_cache(struct dentry *entry) | |
128 | { | |
129 | fuse_dentry_settime(entry, 0); | |
130 | } | |
131 | ||
132 | /* | |
133 | * Same as fuse_invalidate_entry_cache(), but also try to remove the | |
134 | * dentry from the hash | |
135 | */ | |
136 | static void fuse_invalidate_entry(struct dentry *entry) | |
137 | { | |
138 | d_invalidate(entry); | |
139 | fuse_invalidate_entry_cache(entry); | |
140 | } | |
141 | ||
142 | static void fuse_lookup_init(struct fuse_conn *fc, struct fuse_args *args, | |
143 | u64 nodeid, const struct qstr *name, | |
144 | struct fuse_entry_out *outarg) | |
145 | { | |
146 | memset(outarg, 0, sizeof(struct fuse_entry_out)); | |
147 | args->in.h.opcode = FUSE_LOOKUP; | |
148 | args->in.h.nodeid = nodeid; | |
149 | args->in.numargs = 1; | |
150 | args->in.args[0].size = name->len + 1; | |
151 | args->in.args[0].value = name->name; | |
152 | args->out.numargs = 1; | |
153 | args->out.args[0].size = sizeof(struct fuse_entry_out); | |
154 | args->out.args[0].value = outarg; | |
155 | } | |
156 | ||
157 | u64 fuse_get_attr_version(struct fuse_conn *fc) | |
158 | { | |
159 | u64 curr_version; | |
160 | ||
161 | /* | |
162 | * The spin lock isn't actually needed on 64bit archs, but we | |
163 | * don't yet care too much about such optimizations. | |
164 | */ | |
165 | spin_lock(&fc->lock); | |
166 | curr_version = fc->attr_version; | |
167 | spin_unlock(&fc->lock); | |
168 | ||
169 | return curr_version; | |
170 | } | |
171 | ||
172 | /* | |
173 | * Check whether the dentry is still valid | |
174 | * | |
175 | * If the entry validity timeout has expired and the dentry is | |
176 | * positive, try to redo the lookup. If the lookup results in a | |
177 | * different inode, then let the VFS invalidate the dentry and redo | |
178 | * the lookup once more. If the lookup results in the same inode, | |
179 | * then refresh the attributes, timeouts and mark the dentry valid. | |
180 | */ | |
181 | static int fuse_dentry_revalidate(struct dentry *entry, unsigned int flags) | |
182 | { | |
183 | struct inode *inode; | |
184 | struct dentry *parent; | |
185 | struct fuse_conn *fc; | |
186 | struct fuse_inode *fi; | |
187 | int ret; | |
188 | ||
189 | inode = d_inode_rcu(entry); | |
190 | if (inode && is_bad_inode(inode)) | |
191 | goto invalid; | |
192 | else if (time_before64(fuse_dentry_time(entry), get_jiffies_64()) || | |
193 | (flags & LOOKUP_REVAL)) { | |
194 | struct fuse_entry_out outarg; | |
195 | FUSE_ARGS(args); | |
196 | struct fuse_forget_link *forget; | |
197 | u64 attr_version; | |
198 | ||
199 | /* For negative dentries, always do a fresh lookup */ | |
200 | if (!inode) | |
201 | goto invalid; | |
202 | ||
203 | ret = -ECHILD; | |
204 | if (flags & LOOKUP_RCU) | |
205 | goto out; | |
206 | ||
207 | fc = get_fuse_conn(inode); | |
208 | ||
209 | forget = fuse_alloc_forget(); | |
210 | ret = -ENOMEM; | |
211 | if (!forget) | |
212 | goto out; | |
213 | ||
214 | attr_version = fuse_get_attr_version(fc); | |
215 | ||
216 | parent = dget_parent(entry); | |
217 | fuse_lookup_init(fc, &args, get_node_id(d_inode(parent)), | |
218 | &entry->d_name, &outarg); | |
219 | ret = fuse_simple_request(fc, &args); | |
220 | dput(parent); | |
221 | /* Zero nodeid is same as -ENOENT */ | |
222 | if (!ret && !outarg.nodeid) | |
223 | ret = -ENOENT; | |
224 | if (!ret) { | |
225 | fi = get_fuse_inode(inode); | |
226 | if (outarg.nodeid != get_node_id(inode)) { | |
227 | fuse_queue_forget(fc, forget, outarg.nodeid, 1); | |
228 | goto invalid; | |
229 | } | |
230 | spin_lock(&fc->lock); | |
231 | fi->nlookup++; | |
232 | spin_unlock(&fc->lock); | |
233 | } | |
234 | kfree(forget); | |
235 | if (ret == -ENOMEM) | |
236 | goto out; | |
237 | if (ret || (outarg.attr.mode ^ inode->i_mode) & S_IFMT) | |
238 | goto invalid; | |
239 | ||
240 | forget_all_cached_acls(inode); | |
241 | fuse_change_attributes(inode, &outarg.attr, | |
242 | entry_attr_timeout(&outarg), | |
243 | attr_version); | |
244 | fuse_change_entry_timeout(entry, &outarg); | |
245 | } else if (inode) { | |
246 | fi = get_fuse_inode(inode); | |
247 | if (flags & LOOKUP_RCU) { | |
248 | if (test_bit(FUSE_I_INIT_RDPLUS, &fi->state)) | |
249 | return -ECHILD; | |
250 | } else if (test_and_clear_bit(FUSE_I_INIT_RDPLUS, &fi->state)) { | |
251 | parent = dget_parent(entry); | |
252 | fuse_advise_use_readdirplus(d_inode(parent)); | |
253 | dput(parent); | |
254 | } | |
255 | } | |
256 | ret = 1; | |
257 | out: | |
258 | return ret; | |
259 | ||
260 | invalid: | |
261 | ret = 0; | |
262 | goto out; | |
263 | } | |
264 | ||
265 | static int invalid_nodeid(u64 nodeid) | |
266 | { | |
267 | return !nodeid || nodeid == FUSE_ROOT_ID; | |
268 | } | |
269 | ||
270 | static int fuse_dentry_init(struct dentry *dentry) | |
271 | { | |
272 | dentry->d_fsdata = kzalloc(sizeof(union fuse_dentry), GFP_KERNEL); | |
273 | ||
274 | return dentry->d_fsdata ? 0 : -ENOMEM; | |
275 | } | |
276 | static void fuse_dentry_release(struct dentry *dentry) | |
277 | { | |
278 | union fuse_dentry *fd = dentry->d_fsdata; | |
279 | ||
280 | kfree_rcu(fd, rcu); | |
281 | } | |
282 | ||
283 | const struct dentry_operations fuse_dentry_operations = { | |
284 | .d_revalidate = fuse_dentry_revalidate, | |
285 | .d_init = fuse_dentry_init, | |
286 | .d_release = fuse_dentry_release, | |
287 | }; | |
288 | ||
289 | const struct dentry_operations fuse_root_dentry_operations = { | |
290 | .d_init = fuse_dentry_init, | |
291 | .d_release = fuse_dentry_release, | |
292 | }; | |
293 | ||
294 | int fuse_valid_type(int m) | |
295 | { | |
296 | return S_ISREG(m) || S_ISDIR(m) || S_ISLNK(m) || S_ISCHR(m) || | |
297 | S_ISBLK(m) || S_ISFIFO(m) || S_ISSOCK(m); | |
298 | } | |
299 | ||
300 | int fuse_lookup_name(struct super_block *sb, u64 nodeid, const struct qstr *name, | |
301 | struct fuse_entry_out *outarg, struct inode **inode) | |
302 | { | |
303 | struct fuse_conn *fc = get_fuse_conn_super(sb); | |
304 | FUSE_ARGS(args); | |
305 | struct fuse_forget_link *forget; | |
306 | u64 attr_version; | |
307 | int err; | |
308 | ||
309 | *inode = NULL; | |
310 | err = -ENAMETOOLONG; | |
311 | if (name->len > FUSE_NAME_MAX) | |
312 | goto out; | |
313 | ||
314 | ||
315 | forget = fuse_alloc_forget(); | |
316 | err = -ENOMEM; | |
317 | if (!forget) | |
318 | goto out; | |
319 | ||
320 | attr_version = fuse_get_attr_version(fc); | |
321 | ||
322 | fuse_lookup_init(fc, &args, nodeid, name, outarg); | |
323 | err = fuse_simple_request(fc, &args); | |
324 | /* Zero nodeid is same as -ENOENT, but with valid timeout */ | |
325 | if (err || !outarg->nodeid) | |
326 | goto out_put_forget; | |
327 | ||
328 | err = -EIO; | |
329 | if (!outarg->nodeid) | |
330 | goto out_put_forget; | |
331 | if (!fuse_valid_type(outarg->attr.mode)) | |
332 | goto out_put_forget; | |
333 | ||
334 | *inode = fuse_iget(sb, outarg->nodeid, outarg->generation, | |
335 | &outarg->attr, entry_attr_timeout(outarg), | |
336 | attr_version); | |
337 | err = -ENOMEM; | |
338 | if (!*inode) { | |
339 | fuse_queue_forget(fc, forget, outarg->nodeid, 1); | |
340 | goto out; | |
341 | } | |
342 | err = 0; | |
343 | ||
344 | out_put_forget: | |
345 | kfree(forget); | |
346 | out: | |
347 | return err; | |
348 | } | |
349 | ||
350 | static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry, | |
351 | unsigned int flags) | |
352 | { | |
353 | int err; | |
354 | struct fuse_entry_out outarg; | |
355 | struct inode *inode; | |
356 | struct dentry *newent; | |
357 | bool outarg_valid = true; | |
358 | ||
359 | fuse_lock_inode(dir); | |
360 | err = fuse_lookup_name(dir->i_sb, get_node_id(dir), &entry->d_name, | |
361 | &outarg, &inode); | |
362 | fuse_unlock_inode(dir); | |
363 | if (err == -ENOENT) { | |
364 | outarg_valid = false; | |
365 | err = 0; | |
366 | } | |
367 | if (err) | |
368 | goto out_err; | |
369 | ||
370 | err = -EIO; | |
371 | if (inode && get_node_id(inode) == FUSE_ROOT_ID) | |
372 | goto out_iput; | |
373 | ||
374 | newent = d_splice_alias(inode, entry); | |
375 | err = PTR_ERR(newent); | |
376 | if (IS_ERR(newent)) | |
377 | goto out_err; | |
378 | ||
379 | entry = newent ? newent : entry; | |
380 | if (outarg_valid) | |
381 | fuse_change_entry_timeout(entry, &outarg); | |
382 | else | |
383 | fuse_invalidate_entry_cache(entry); | |
384 | ||
385 | fuse_advise_use_readdirplus(dir); | |
386 | return newent; | |
387 | ||
388 | out_iput: | |
389 | iput(inode); | |
390 | out_err: | |
391 | return ERR_PTR(err); | |
392 | } | |
393 | ||
394 | /* | |
395 | * Atomic create+open operation | |
396 | * | |
397 | * If the filesystem doesn't support this, then fall back to separate | |
398 | * 'mknod' + 'open' requests. | |
399 | */ | |
400 | static int fuse_create_open(struct inode *dir, struct dentry *entry, | |
401 | struct file *file, unsigned flags, | |
402 | umode_t mode, int *opened) | |
403 | { | |
404 | int err; | |
405 | struct inode *inode; | |
406 | struct fuse_conn *fc = get_fuse_conn(dir); | |
407 | FUSE_ARGS(args); | |
408 | struct fuse_forget_link *forget; | |
409 | struct fuse_create_in inarg; | |
410 | struct fuse_open_out outopen; | |
411 | struct fuse_entry_out outentry; | |
412 | struct fuse_file *ff; | |
413 | ||
414 | /* Userspace expects S_IFREG in create mode */ | |
415 | BUG_ON((mode & S_IFMT) != S_IFREG); | |
416 | ||
417 | forget = fuse_alloc_forget(); | |
418 | err = -ENOMEM; | |
419 | if (!forget) | |
420 | goto out_err; | |
421 | ||
422 | err = -ENOMEM; | |
423 | ff = fuse_file_alloc(fc); | |
424 | if (!ff) | |
425 | goto out_put_forget_req; | |
426 | ||
427 | if (!fc->dont_mask) | |
428 | mode &= ~current_umask(); | |
429 | ||
430 | flags &= ~O_NOCTTY; | |
431 | memset(&inarg, 0, sizeof(inarg)); | |
432 | memset(&outentry, 0, sizeof(outentry)); | |
433 | inarg.flags = flags; | |
434 | inarg.mode = mode; | |
435 | inarg.umask = current_umask(); | |
436 | args.in.h.opcode = FUSE_CREATE; | |
437 | args.in.h.nodeid = get_node_id(dir); | |
438 | args.in.numargs = 2; | |
439 | args.in.args[0].size = sizeof(inarg); | |
440 | args.in.args[0].value = &inarg; | |
441 | args.in.args[1].size = entry->d_name.len + 1; | |
442 | args.in.args[1].value = entry->d_name.name; | |
443 | args.out.numargs = 2; | |
444 | args.out.args[0].size = sizeof(outentry); | |
445 | args.out.args[0].value = &outentry; | |
446 | args.out.args[1].size = sizeof(outopen); | |
447 | args.out.args[1].value = &outopen; | |
448 | err = fuse_simple_request(fc, &args); | |
449 | if (err) | |
450 | goto out_free_ff; | |
451 | ||
452 | err = -EIO; | |
453 | if (!S_ISREG(outentry.attr.mode) || invalid_nodeid(outentry.nodeid)) | |
454 | goto out_free_ff; | |
455 | ||
456 | ff->fh = outopen.fh; | |
457 | ff->nodeid = outentry.nodeid; | |
458 | ff->open_flags = outopen.open_flags; | |
459 | inode = fuse_iget(dir->i_sb, outentry.nodeid, outentry.generation, | |
460 | &outentry.attr, entry_attr_timeout(&outentry), 0); | |
461 | if (!inode) { | |
462 | flags &= ~(O_CREAT | O_EXCL | O_TRUNC); | |
463 | fuse_sync_release(ff, flags); | |
464 | fuse_queue_forget(fc, forget, outentry.nodeid, 1); | |
465 | err = -ENOMEM; | |
466 | goto out_err; | |
467 | } | |
468 | kfree(forget); | |
469 | d_instantiate(entry, inode); | |
470 | fuse_change_entry_timeout(entry, &outentry); | |
471 | fuse_invalidate_attr(dir); | |
472 | err = finish_open(file, entry, generic_file_open, opened); | |
473 | if (err) { | |
474 | fuse_sync_release(ff, flags); | |
475 | } else { | |
476 | file->private_data = fuse_file_get(ff); | |
477 | fuse_finish_open(inode, file); | |
478 | } | |
479 | return err; | |
480 | ||
481 | out_free_ff: | |
482 | fuse_file_free(ff); | |
483 | out_put_forget_req: | |
484 | kfree(forget); | |
485 | out_err: | |
486 | return err; | |
487 | } | |
488 | ||
489 | static int fuse_mknod(struct inode *, struct dentry *, umode_t, dev_t); | |
490 | static int fuse_atomic_open(struct inode *dir, struct dentry *entry, | |
491 | struct file *file, unsigned flags, | |
492 | umode_t mode, int *opened) | |
493 | { | |
494 | int err; | |
495 | struct fuse_conn *fc = get_fuse_conn(dir); | |
496 | struct dentry *res = NULL; | |
497 | ||
498 | if (d_in_lookup(entry)) { | |
499 | res = fuse_lookup(dir, entry, 0); | |
500 | if (IS_ERR(res)) | |
501 | return PTR_ERR(res); | |
502 | ||
503 | if (res) | |
504 | entry = res; | |
505 | } | |
506 | ||
507 | if (!(flags & O_CREAT) || d_really_is_positive(entry)) | |
508 | goto no_open; | |
509 | ||
510 | /* Only creates */ | |
511 | *opened |= FILE_CREATED; | |
512 | ||
513 | if (fc->no_create) | |
514 | goto mknod; | |
515 | ||
516 | err = fuse_create_open(dir, entry, file, flags, mode, opened); | |
517 | if (err == -ENOSYS) { | |
518 | fc->no_create = 1; | |
519 | goto mknod; | |
520 | } | |
521 | out_dput: | |
522 | dput(res); | |
523 | return err; | |
524 | ||
525 | mknod: | |
526 | err = fuse_mknod(dir, entry, mode, 0); | |
527 | if (err) | |
528 | goto out_dput; | |
529 | no_open: | |
530 | return finish_no_open(file, res); | |
531 | } | |
532 | ||
533 | /* | |
534 | * Code shared between mknod, mkdir, symlink and link | |
535 | */ | |
536 | static int create_new_entry(struct fuse_conn *fc, struct fuse_args *args, | |
537 | struct inode *dir, struct dentry *entry, | |
538 | umode_t mode) | |
539 | { | |
540 | struct fuse_entry_out outarg; | |
541 | struct inode *inode; | |
542 | int err; | |
543 | struct fuse_forget_link *forget; | |
544 | ||
545 | forget = fuse_alloc_forget(); | |
546 | if (!forget) | |
547 | return -ENOMEM; | |
548 | ||
549 | memset(&outarg, 0, sizeof(outarg)); | |
550 | args->in.h.nodeid = get_node_id(dir); | |
551 | args->out.numargs = 1; | |
552 | args->out.args[0].size = sizeof(outarg); | |
553 | args->out.args[0].value = &outarg; | |
554 | err = fuse_simple_request(fc, args); | |
555 | if (err) | |
556 | goto out_put_forget_req; | |
557 | ||
558 | err = -EIO; | |
559 | if (invalid_nodeid(outarg.nodeid)) | |
560 | goto out_put_forget_req; | |
561 | ||
562 | if ((outarg.attr.mode ^ mode) & S_IFMT) | |
563 | goto out_put_forget_req; | |
564 | ||
565 | inode = fuse_iget(dir->i_sb, outarg.nodeid, outarg.generation, | |
566 | &outarg.attr, entry_attr_timeout(&outarg), 0); | |
567 | if (!inode) { | |
568 | fuse_queue_forget(fc, forget, outarg.nodeid, 1); | |
569 | return -ENOMEM; | |
570 | } | |
571 | kfree(forget); | |
572 | ||
573 | err = d_instantiate_no_diralias(entry, inode); | |
574 | if (err) | |
575 | return err; | |
576 | ||
577 | fuse_change_entry_timeout(entry, &outarg); | |
578 | fuse_invalidate_attr(dir); | |
579 | return 0; | |
580 | ||
581 | out_put_forget_req: | |
582 | kfree(forget); | |
583 | return err; | |
584 | } | |
585 | ||
586 | static int fuse_mknod(struct inode *dir, struct dentry *entry, umode_t mode, | |
587 | dev_t rdev) | |
588 | { | |
589 | struct fuse_mknod_in inarg; | |
590 | struct fuse_conn *fc = get_fuse_conn(dir); | |
591 | FUSE_ARGS(args); | |
592 | ||
593 | if (!fc->dont_mask) | |
594 | mode &= ~current_umask(); | |
595 | ||
596 | memset(&inarg, 0, sizeof(inarg)); | |
597 | inarg.mode = mode; | |
598 | inarg.rdev = new_encode_dev(rdev); | |
599 | inarg.umask = current_umask(); | |
600 | args.in.h.opcode = FUSE_MKNOD; | |
601 | args.in.numargs = 2; | |
602 | args.in.args[0].size = sizeof(inarg); | |
603 | args.in.args[0].value = &inarg; | |
604 | args.in.args[1].size = entry->d_name.len + 1; | |
605 | args.in.args[1].value = entry->d_name.name; | |
606 | return create_new_entry(fc, &args, dir, entry, mode); | |
607 | } | |
608 | ||
609 | static int fuse_create(struct inode *dir, struct dentry *entry, umode_t mode, | |
610 | bool excl) | |
611 | { | |
612 | return fuse_mknod(dir, entry, mode, 0); | |
613 | } | |
614 | ||
615 | static int fuse_mkdir(struct inode *dir, struct dentry *entry, umode_t mode) | |
616 | { | |
617 | struct fuse_mkdir_in inarg; | |
618 | struct fuse_conn *fc = get_fuse_conn(dir); | |
619 | FUSE_ARGS(args); | |
620 | ||
621 | if (!fc->dont_mask) | |
622 | mode &= ~current_umask(); | |
623 | ||
624 | memset(&inarg, 0, sizeof(inarg)); | |
625 | inarg.mode = mode; | |
626 | inarg.umask = current_umask(); | |
627 | args.in.h.opcode = FUSE_MKDIR; | |
628 | args.in.numargs = 2; | |
629 | args.in.args[0].size = sizeof(inarg); | |
630 | args.in.args[0].value = &inarg; | |
631 | args.in.args[1].size = entry->d_name.len + 1; | |
632 | args.in.args[1].value = entry->d_name.name; | |
633 | return create_new_entry(fc, &args, dir, entry, S_IFDIR); | |
634 | } | |
635 | ||
636 | static int fuse_symlink(struct inode *dir, struct dentry *entry, | |
637 | const char *link) | |
638 | { | |
639 | struct fuse_conn *fc = get_fuse_conn(dir); | |
640 | unsigned len = strlen(link) + 1; | |
641 | FUSE_ARGS(args); | |
642 | ||
643 | args.in.h.opcode = FUSE_SYMLINK; | |
644 | args.in.numargs = 2; | |
645 | args.in.args[0].size = entry->d_name.len + 1; | |
646 | args.in.args[0].value = entry->d_name.name; | |
647 | args.in.args[1].size = len; | |
648 | args.in.args[1].value = link; | |
649 | return create_new_entry(fc, &args, dir, entry, S_IFLNK); | |
650 | } | |
651 | ||
652 | void fuse_update_ctime(struct inode *inode) | |
653 | { | |
654 | if (!IS_NOCMTIME(inode)) { | |
655 | inode->i_ctime = current_time(inode); | |
656 | mark_inode_dirty_sync(inode); | |
657 | } | |
658 | } | |
659 | ||
660 | static int fuse_unlink(struct inode *dir, struct dentry *entry) | |
661 | { | |
662 | int err; | |
663 | struct fuse_conn *fc = get_fuse_conn(dir); | |
664 | FUSE_ARGS(args); | |
665 | ||
666 | args.in.h.opcode = FUSE_UNLINK; | |
667 | args.in.h.nodeid = get_node_id(dir); | |
668 | args.in.numargs = 1; | |
669 | args.in.args[0].size = entry->d_name.len + 1; | |
670 | args.in.args[0].value = entry->d_name.name; | |
671 | err = fuse_simple_request(fc, &args); | |
672 | if (!err) { | |
673 | struct inode *inode = d_inode(entry); | |
674 | struct fuse_inode *fi = get_fuse_inode(inode); | |
675 | ||
676 | spin_lock(&fc->lock); | |
677 | fi->attr_version = ++fc->attr_version; | |
678 | /* | |
679 | * If i_nlink == 0 then unlink doesn't make sense, yet this can | |
680 | * happen if userspace filesystem is careless. It would be | |
681 | * difficult to enforce correct nlink usage so just ignore this | |
682 | * condition here | |
683 | */ | |
684 | if (inode->i_nlink > 0) | |
685 | drop_nlink(inode); | |
686 | spin_unlock(&fc->lock); | |
687 | fuse_invalidate_attr(inode); | |
688 | fuse_invalidate_attr(dir); | |
689 | fuse_invalidate_entry_cache(entry); | |
690 | fuse_update_ctime(inode); | |
691 | } else if (err == -EINTR) | |
692 | fuse_invalidate_entry(entry); | |
693 | return err; | |
694 | } | |
695 | ||
696 | static int fuse_rmdir(struct inode *dir, struct dentry *entry) | |
697 | { | |
698 | int err; | |
699 | struct fuse_conn *fc = get_fuse_conn(dir); | |
700 | FUSE_ARGS(args); | |
701 | ||
702 | args.in.h.opcode = FUSE_RMDIR; | |
703 | args.in.h.nodeid = get_node_id(dir); | |
704 | args.in.numargs = 1; | |
705 | args.in.args[0].size = entry->d_name.len + 1; | |
706 | args.in.args[0].value = entry->d_name.name; | |
707 | err = fuse_simple_request(fc, &args); | |
708 | if (!err) { | |
709 | clear_nlink(d_inode(entry)); | |
710 | fuse_invalidate_attr(dir); | |
711 | fuse_invalidate_entry_cache(entry); | |
712 | } else if (err == -EINTR) | |
713 | fuse_invalidate_entry(entry); | |
714 | return err; | |
715 | } | |
716 | ||
717 | static int fuse_rename_common(struct inode *olddir, struct dentry *oldent, | |
718 | struct inode *newdir, struct dentry *newent, | |
719 | unsigned int flags, int opcode, size_t argsize) | |
720 | { | |
721 | int err; | |
722 | struct fuse_rename2_in inarg; | |
723 | struct fuse_conn *fc = get_fuse_conn(olddir); | |
724 | FUSE_ARGS(args); | |
725 | ||
726 | memset(&inarg, 0, argsize); | |
727 | inarg.newdir = get_node_id(newdir); | |
728 | inarg.flags = flags; | |
729 | args.in.h.opcode = opcode; | |
730 | args.in.h.nodeid = get_node_id(olddir); | |
731 | args.in.numargs = 3; | |
732 | args.in.args[0].size = argsize; | |
733 | args.in.args[0].value = &inarg; | |
734 | args.in.args[1].size = oldent->d_name.len + 1; | |
735 | args.in.args[1].value = oldent->d_name.name; | |
736 | args.in.args[2].size = newent->d_name.len + 1; | |
737 | args.in.args[2].value = newent->d_name.name; | |
738 | err = fuse_simple_request(fc, &args); | |
739 | if (!err) { | |
740 | /* ctime changes */ | |
741 | fuse_invalidate_attr(d_inode(oldent)); | |
742 | fuse_update_ctime(d_inode(oldent)); | |
743 | ||
744 | if (flags & RENAME_EXCHANGE) { | |
745 | fuse_invalidate_attr(d_inode(newent)); | |
746 | fuse_update_ctime(d_inode(newent)); | |
747 | } | |
748 | ||
749 | fuse_invalidate_attr(olddir); | |
750 | if (olddir != newdir) | |
751 | fuse_invalidate_attr(newdir); | |
752 | ||
753 | /* newent will end up negative */ | |
754 | if (!(flags & RENAME_EXCHANGE) && d_really_is_positive(newent)) { | |
755 | fuse_invalidate_attr(d_inode(newent)); | |
756 | fuse_invalidate_entry_cache(newent); | |
757 | fuse_update_ctime(d_inode(newent)); | |
758 | } | |
759 | } else if (err == -EINTR) { | |
760 | /* If request was interrupted, DEITY only knows if the | |
761 | rename actually took place. If the invalidation | |
762 | fails (e.g. some process has CWD under the renamed | |
763 | directory), then there can be inconsistency between | |
764 | the dcache and the real filesystem. Tough luck. */ | |
765 | fuse_invalidate_entry(oldent); | |
766 | if (d_really_is_positive(newent)) | |
767 | fuse_invalidate_entry(newent); | |
768 | } | |
769 | ||
770 | return err; | |
771 | } | |
772 | ||
773 | static int fuse_rename2(struct inode *olddir, struct dentry *oldent, | |
774 | struct inode *newdir, struct dentry *newent, | |
775 | unsigned int flags) | |
776 | { | |
777 | struct fuse_conn *fc = get_fuse_conn(olddir); | |
778 | int err; | |
779 | ||
780 | if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE)) | |
781 | return -EINVAL; | |
782 | ||
783 | if (flags) { | |
784 | if (fc->no_rename2 || fc->minor < 23) | |
785 | return -EINVAL; | |
786 | ||
787 | err = fuse_rename_common(olddir, oldent, newdir, newent, flags, | |
788 | FUSE_RENAME2, | |
789 | sizeof(struct fuse_rename2_in)); | |
790 | if (err == -ENOSYS) { | |
791 | fc->no_rename2 = 1; | |
792 | err = -EINVAL; | |
793 | } | |
794 | } else { | |
795 | err = fuse_rename_common(olddir, oldent, newdir, newent, 0, | |
796 | FUSE_RENAME, | |
797 | sizeof(struct fuse_rename_in)); | |
798 | } | |
799 | ||
800 | return err; | |
801 | } | |
802 | ||
803 | static int fuse_link(struct dentry *entry, struct inode *newdir, | |
804 | struct dentry *newent) | |
805 | { | |
806 | int err; | |
807 | struct fuse_link_in inarg; | |
808 | struct inode *inode = d_inode(entry); | |
809 | struct fuse_conn *fc = get_fuse_conn(inode); | |
810 | FUSE_ARGS(args); | |
811 | ||
812 | memset(&inarg, 0, sizeof(inarg)); | |
813 | inarg.oldnodeid = get_node_id(inode); | |
814 | args.in.h.opcode = FUSE_LINK; | |
815 | args.in.numargs = 2; | |
816 | args.in.args[0].size = sizeof(inarg); | |
817 | args.in.args[0].value = &inarg; | |
818 | args.in.args[1].size = newent->d_name.len + 1; | |
819 | args.in.args[1].value = newent->d_name.name; | |
820 | err = create_new_entry(fc, &args, newdir, newent, inode->i_mode); | |
821 | /* Contrary to "normal" filesystems it can happen that link | |
822 | makes two "logical" inodes point to the same "physical" | |
823 | inode. We invalidate the attributes of the old one, so it | |
824 | will reflect changes in the backing inode (link count, | |
825 | etc.) | |
826 | */ | |
827 | if (!err) { | |
828 | struct fuse_inode *fi = get_fuse_inode(inode); | |
829 | ||
830 | spin_lock(&fc->lock); | |
831 | fi->attr_version = ++fc->attr_version; | |
832 | inc_nlink(inode); | |
833 | spin_unlock(&fc->lock); | |
834 | fuse_invalidate_attr(inode); | |
835 | fuse_update_ctime(inode); | |
836 | } else if (err == -EINTR) { | |
837 | fuse_invalidate_attr(inode); | |
838 | } | |
839 | return err; | |
840 | } | |
841 | ||
842 | static void fuse_fillattr(struct inode *inode, struct fuse_attr *attr, | |
843 | struct kstat *stat) | |
844 | { | |
845 | unsigned int blkbits; | |
846 | struct fuse_conn *fc = get_fuse_conn(inode); | |
847 | ||
848 | /* see the comment in fuse_change_attributes() */ | |
849 | if (fc->writeback_cache && S_ISREG(inode->i_mode)) { | |
850 | attr->size = i_size_read(inode); | |
851 | attr->mtime = inode->i_mtime.tv_sec; | |
852 | attr->mtimensec = inode->i_mtime.tv_nsec; | |
853 | attr->ctime = inode->i_ctime.tv_sec; | |
854 | attr->ctimensec = inode->i_ctime.tv_nsec; | |
855 | } | |
856 | ||
857 | stat->dev = inode->i_sb->s_dev; | |
858 | stat->ino = attr->ino; | |
859 | stat->mode = (inode->i_mode & S_IFMT) | (attr->mode & 07777); | |
860 | stat->nlink = attr->nlink; | |
861 | stat->uid = make_kuid(fc->user_ns, attr->uid); | |
862 | stat->gid = make_kgid(fc->user_ns, attr->gid); | |
863 | stat->rdev = inode->i_rdev; | |
864 | stat->atime.tv_sec = attr->atime; | |
865 | stat->atime.tv_nsec = attr->atimensec; | |
866 | stat->mtime.tv_sec = attr->mtime; | |
867 | stat->mtime.tv_nsec = attr->mtimensec; | |
868 | stat->ctime.tv_sec = attr->ctime; | |
869 | stat->ctime.tv_nsec = attr->ctimensec; | |
870 | stat->size = attr->size; | |
871 | stat->blocks = attr->blocks; | |
872 | ||
873 | if (attr->blksize != 0) | |
874 | blkbits = ilog2(attr->blksize); | |
875 | else | |
876 | blkbits = inode->i_sb->s_blocksize_bits; | |
877 | ||
878 | stat->blksize = 1 << blkbits; | |
879 | } | |
880 | ||
881 | static int fuse_do_getattr(struct inode *inode, struct kstat *stat, | |
882 | struct file *file) | |
883 | { | |
884 | int err; | |
885 | struct fuse_getattr_in inarg; | |
886 | struct fuse_attr_out outarg; | |
887 | struct fuse_conn *fc = get_fuse_conn(inode); | |
888 | FUSE_ARGS(args); | |
889 | u64 attr_version; | |
890 | ||
891 | attr_version = fuse_get_attr_version(fc); | |
892 | ||
893 | memset(&inarg, 0, sizeof(inarg)); | |
894 | memset(&outarg, 0, sizeof(outarg)); | |
895 | /* Directories have separate file-handle space */ | |
896 | if (file && S_ISREG(inode->i_mode)) { | |
897 | struct fuse_file *ff = file->private_data; | |
898 | ||
899 | inarg.getattr_flags |= FUSE_GETATTR_FH; | |
900 | inarg.fh = ff->fh; | |
901 | } | |
902 | args.in.h.opcode = FUSE_GETATTR; | |
903 | args.in.h.nodeid = get_node_id(inode); | |
904 | args.in.numargs = 1; | |
905 | args.in.args[0].size = sizeof(inarg); | |
906 | args.in.args[0].value = &inarg; | |
907 | args.out.numargs = 1; | |
908 | args.out.args[0].size = sizeof(outarg); | |
909 | args.out.args[0].value = &outarg; | |
910 | err = fuse_simple_request(fc, &args); | |
911 | if (!err) { | |
912 | if ((inode->i_mode ^ outarg.attr.mode) & S_IFMT) { | |
913 | make_bad_inode(inode); | |
914 | err = -EIO; | |
915 | } else { | |
916 | fuse_change_attributes(inode, &outarg.attr, | |
917 | attr_timeout(&outarg), | |
918 | attr_version); | |
919 | if (stat) | |
920 | fuse_fillattr(inode, &outarg.attr, stat); | |
921 | } | |
922 | } | |
923 | return err; | |
924 | } | |
925 | ||
926 | int fuse_update_attributes(struct inode *inode, struct kstat *stat, | |
927 | struct file *file, bool *refreshed) | |
928 | { | |
929 | struct fuse_inode *fi = get_fuse_inode(inode); | |
930 | int err; | |
931 | bool r; | |
932 | ||
933 | if (time_before64(fi->i_time, get_jiffies_64())) { | |
934 | r = true; | |
935 | forget_all_cached_acls(inode); | |
936 | err = fuse_do_getattr(inode, stat, file); | |
937 | } else { | |
938 | r = false; | |
939 | err = 0; | |
940 | if (stat) { | |
941 | generic_fillattr(inode, stat); | |
942 | stat->mode = fi->orig_i_mode; | |
943 | stat->ino = fi->orig_ino; | |
944 | } | |
945 | } | |
946 | ||
947 | if (refreshed != NULL) | |
948 | *refreshed = r; | |
949 | ||
950 | return err; | |
951 | } | |
952 | ||
953 | int fuse_reverse_inval_entry(struct super_block *sb, u64 parent_nodeid, | |
954 | u64 child_nodeid, struct qstr *name) | |
955 | { | |
956 | int err = -ENOTDIR; | |
957 | struct inode *parent; | |
958 | struct dentry *dir; | |
959 | struct dentry *entry; | |
960 | ||
961 | parent = ilookup5(sb, parent_nodeid, fuse_inode_eq, &parent_nodeid); | |
962 | if (!parent) | |
963 | return -ENOENT; | |
964 | ||
965 | inode_lock(parent); | |
966 | if (!S_ISDIR(parent->i_mode)) | |
967 | goto unlock; | |
968 | ||
969 | err = -ENOENT; | |
970 | dir = d_find_alias(parent); | |
971 | if (!dir) | |
972 | goto unlock; | |
973 | ||
974 | name->hash = full_name_hash(dir, name->name, name->len); | |
975 | entry = d_lookup(dir, name); | |
976 | dput(dir); | |
977 | if (!entry) | |
978 | goto unlock; | |
979 | ||
980 | fuse_invalidate_attr(parent); | |
981 | fuse_invalidate_entry(entry); | |
982 | ||
983 | if (child_nodeid != 0 && d_really_is_positive(entry)) { | |
984 | inode_lock(d_inode(entry)); | |
985 | if (get_node_id(d_inode(entry)) != child_nodeid) { | |
986 | err = -ENOENT; | |
987 | goto badentry; | |
988 | } | |
989 | if (d_mountpoint(entry)) { | |
990 | err = -EBUSY; | |
991 | goto badentry; | |
992 | } | |
993 | if (d_is_dir(entry)) { | |
994 | shrink_dcache_parent(entry); | |
995 | if (!simple_empty(entry)) { | |
996 | err = -ENOTEMPTY; | |
997 | goto badentry; | |
998 | } | |
999 | d_inode(entry)->i_flags |= S_DEAD; | |
1000 | } | |
1001 | dont_mount(entry); | |
1002 | clear_nlink(d_inode(entry)); | |
1003 | err = 0; | |
1004 | badentry: | |
1005 | inode_unlock(d_inode(entry)); | |
1006 | if (!err) | |
1007 | d_delete(entry); | |
1008 | } else { | |
1009 | err = 0; | |
1010 | } | |
1011 | dput(entry); | |
1012 | ||
1013 | unlock: | |
1014 | inode_unlock(parent); | |
1015 | iput(parent); | |
1016 | return err; | |
1017 | } | |
1018 | ||
1019 | /* | |
1020 | * Calling into a user-controlled filesystem gives the filesystem | |
1021 | * daemon ptrace-like capabilities over the current process. This | |
1022 | * means, that the filesystem daemon is able to record the exact | |
1023 | * filesystem operations performed, and can also control the behavior | |
1024 | * of the requester process in otherwise impossible ways. For example | |
1025 | * it can delay the operation for arbitrary length of time allowing | |
1026 | * DoS against the requester. | |
1027 | * | |
1028 | * For this reason only those processes can call into the filesystem, | |
1029 | * for which the owner of the mount has ptrace privilege. This | |
1030 | * excludes processes started by other users, suid or sgid processes. | |
1031 | */ | |
1032 | int fuse_allow_current_process(struct fuse_conn *fc) | |
1033 | { | |
1034 | const struct cred *cred; | |
1035 | ||
1036 | if (fc->allow_other) | |
1037 | return current_in_userns(fc->user_ns); | |
1038 | ||
1039 | cred = current_cred(); | |
1040 | if (uid_eq(cred->euid, fc->user_id) && | |
1041 | uid_eq(cred->suid, fc->user_id) && | |
1042 | uid_eq(cred->uid, fc->user_id) && | |
1043 | gid_eq(cred->egid, fc->group_id) && | |
1044 | gid_eq(cred->sgid, fc->group_id) && | |
1045 | gid_eq(cred->gid, fc->group_id)) | |
1046 | return 1; | |
1047 | ||
1048 | return 0; | |
1049 | } | |
1050 | ||
1051 | static int fuse_access(struct inode *inode, int mask) | |
1052 | { | |
1053 | struct fuse_conn *fc = get_fuse_conn(inode); | |
1054 | FUSE_ARGS(args); | |
1055 | struct fuse_access_in inarg; | |
1056 | int err; | |
1057 | ||
1058 | BUG_ON(mask & MAY_NOT_BLOCK); | |
1059 | ||
1060 | if (fc->no_access) | |
1061 | return 0; | |
1062 | ||
1063 | memset(&inarg, 0, sizeof(inarg)); | |
1064 | inarg.mask = mask & (MAY_READ | MAY_WRITE | MAY_EXEC); | |
1065 | args.in.h.opcode = FUSE_ACCESS; | |
1066 | args.in.h.nodeid = get_node_id(inode); | |
1067 | args.in.numargs = 1; | |
1068 | args.in.args[0].size = sizeof(inarg); | |
1069 | args.in.args[0].value = &inarg; | |
1070 | err = fuse_simple_request(fc, &args); | |
1071 | if (err == -ENOSYS) { | |
1072 | fc->no_access = 1; | |
1073 | err = 0; | |
1074 | } | |
1075 | return err; | |
1076 | } | |
1077 | ||
1078 | static int fuse_perm_getattr(struct inode *inode, int mask) | |
1079 | { | |
1080 | if (mask & MAY_NOT_BLOCK) | |
1081 | return -ECHILD; | |
1082 | ||
1083 | forget_all_cached_acls(inode); | |
1084 | return fuse_do_getattr(inode, NULL, NULL); | |
1085 | } | |
1086 | ||
1087 | /* | |
1088 | * Check permission. The two basic access models of FUSE are: | |
1089 | * | |
1090 | * 1) Local access checking ('default_permissions' mount option) based | |
1091 | * on file mode. This is the plain old disk filesystem permission | |
1092 | * modell. | |
1093 | * | |
1094 | * 2) "Remote" access checking, where server is responsible for | |
1095 | * checking permission in each inode operation. An exception to this | |
1096 | * is if ->permission() was invoked from sys_access() in which case an | |
1097 | * access request is sent. Execute permission is still checked | |
1098 | * locally based on file mode. | |
1099 | */ | |
1100 | static int fuse_permission(struct inode *inode, int mask) | |
1101 | { | |
1102 | struct fuse_conn *fc = get_fuse_conn(inode); | |
1103 | bool refreshed = false; | |
1104 | int err = 0; | |
1105 | ||
1106 | if (!fuse_allow_current_process(fc)) | |
1107 | return -EACCES; | |
1108 | ||
1109 | /* | |
1110 | * If attributes are needed, refresh them before proceeding | |
1111 | */ | |
1112 | if (fc->default_permissions || | |
1113 | ((mask & MAY_EXEC) && S_ISREG(inode->i_mode))) { | |
1114 | struct fuse_inode *fi = get_fuse_inode(inode); | |
1115 | ||
1116 | if (time_before64(fi->i_time, get_jiffies_64())) { | |
1117 | refreshed = true; | |
1118 | ||
1119 | err = fuse_perm_getattr(inode, mask); | |
1120 | if (err) | |
1121 | return err; | |
1122 | } | |
1123 | } | |
1124 | ||
1125 | if (fc->default_permissions) { | |
1126 | err = generic_permission(inode, mask); | |
1127 | ||
1128 | /* If permission is denied, try to refresh file | |
1129 | attributes. This is also needed, because the root | |
1130 | node will at first have no permissions */ | |
1131 | if (err == -EACCES && !refreshed) { | |
1132 | err = fuse_perm_getattr(inode, mask); | |
1133 | if (!err) | |
1134 | err = generic_permission(inode, mask); | |
1135 | } | |
1136 | ||
1137 | /* Note: the opposite of the above test does not | |
1138 | exist. So if permissions are revoked this won't be | |
1139 | noticed immediately, only after the attribute | |
1140 | timeout has expired */ | |
1141 | } else if (mask & (MAY_ACCESS | MAY_CHDIR)) { | |
1142 | err = fuse_access(inode, mask); | |
1143 | } else if ((mask & MAY_EXEC) && S_ISREG(inode->i_mode)) { | |
1144 | if (!(inode->i_mode & S_IXUGO)) { | |
1145 | if (refreshed) | |
1146 | return -EACCES; | |
1147 | ||
1148 | err = fuse_perm_getattr(inode, mask); | |
1149 | if (!err && !(inode->i_mode & S_IXUGO)) | |
1150 | return -EACCES; | |
1151 | } | |
1152 | } | |
1153 | return err; | |
1154 | } | |
1155 | ||
1156 | static int parse_dirfile(char *buf, size_t nbytes, struct file *file, | |
1157 | struct dir_context *ctx) | |
1158 | { | |
1159 | while (nbytes >= FUSE_NAME_OFFSET) { | |
1160 | struct fuse_dirent *dirent = (struct fuse_dirent *) buf; | |
1161 | size_t reclen = FUSE_DIRENT_SIZE(dirent); | |
1162 | if (!dirent->namelen || dirent->namelen > FUSE_NAME_MAX) | |
1163 | return -EIO; | |
1164 | if (reclen > nbytes) | |
1165 | break; | |
1166 | if (memchr(dirent->name, '/', dirent->namelen) != NULL) | |
1167 | return -EIO; | |
1168 | ||
1169 | if (!dir_emit(ctx, dirent->name, dirent->namelen, | |
1170 | dirent->ino, dirent->type)) | |
1171 | break; | |
1172 | ||
1173 | buf += reclen; | |
1174 | nbytes -= reclen; | |
1175 | ctx->pos = dirent->off; | |
1176 | } | |
1177 | ||
1178 | return 0; | |
1179 | } | |
1180 | ||
1181 | static int fuse_direntplus_link(struct file *file, | |
1182 | struct fuse_direntplus *direntplus, | |
1183 | u64 attr_version) | |
1184 | { | |
1185 | struct fuse_entry_out *o = &direntplus->entry_out; | |
1186 | struct fuse_dirent *dirent = &direntplus->dirent; | |
1187 | struct dentry *parent = file->f_path.dentry; | |
1188 | struct qstr name = QSTR_INIT(dirent->name, dirent->namelen); | |
1189 | struct dentry *dentry; | |
1190 | struct dentry *alias; | |
1191 | struct inode *dir = d_inode(parent); | |
1192 | struct fuse_conn *fc; | |
1193 | struct inode *inode; | |
1194 | DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq); | |
1195 | ||
1196 | if (!o->nodeid) { | |
1197 | /* | |
1198 | * Unlike in the case of fuse_lookup, zero nodeid does not mean | |
1199 | * ENOENT. Instead, it only means the userspace filesystem did | |
1200 | * not want to return attributes/handle for this entry. | |
1201 | * | |
1202 | * So do nothing. | |
1203 | */ | |
1204 | return 0; | |
1205 | } | |
1206 | ||
1207 | if (name.name[0] == '.') { | |
1208 | /* | |
1209 | * We could potentially refresh the attributes of the directory | |
1210 | * and its parent? | |
1211 | */ | |
1212 | if (name.len == 1) | |
1213 | return 0; | |
1214 | if (name.name[1] == '.' && name.len == 2) | |
1215 | return 0; | |
1216 | } | |
1217 | ||
1218 | if (invalid_nodeid(o->nodeid)) | |
1219 | return -EIO; | |
1220 | if (!fuse_valid_type(o->attr.mode)) | |
1221 | return -EIO; | |
1222 | ||
1223 | fc = get_fuse_conn(dir); | |
1224 | ||
1225 | name.hash = full_name_hash(parent, name.name, name.len); | |
1226 | dentry = d_lookup(parent, &name); | |
1227 | if (!dentry) { | |
1228 | retry: | |
1229 | dentry = d_alloc_parallel(parent, &name, &wq); | |
1230 | if (IS_ERR(dentry)) | |
1231 | return PTR_ERR(dentry); | |
1232 | } | |
1233 | if (!d_in_lookup(dentry)) { | |
1234 | struct fuse_inode *fi; | |
1235 | inode = d_inode(dentry); | |
1236 | if (!inode || | |
1237 | get_node_id(inode) != o->nodeid || | |
1238 | ((o->attr.mode ^ inode->i_mode) & S_IFMT)) { | |
1239 | d_invalidate(dentry); | |
1240 | dput(dentry); | |
1241 | goto retry; | |
1242 | } | |
1243 | if (is_bad_inode(inode)) { | |
1244 | dput(dentry); | |
1245 | return -EIO; | |
1246 | } | |
1247 | ||
1248 | fi = get_fuse_inode(inode); | |
1249 | spin_lock(&fc->lock); | |
1250 | fi->nlookup++; | |
1251 | spin_unlock(&fc->lock); | |
1252 | ||
1253 | forget_all_cached_acls(inode); | |
1254 | fuse_change_attributes(inode, &o->attr, | |
1255 | entry_attr_timeout(o), | |
1256 | attr_version); | |
1257 | /* | |
1258 | * The other branch comes via fuse_iget() | |
1259 | * which bumps nlookup inside | |
1260 | */ | |
1261 | } else { | |
1262 | inode = fuse_iget(dir->i_sb, o->nodeid, o->generation, | |
1263 | &o->attr, entry_attr_timeout(o), | |
1264 | attr_version); | |
1265 | if (!inode) | |
1266 | inode = ERR_PTR(-ENOMEM); | |
1267 | ||
1268 | alias = d_splice_alias(inode, dentry); | |
1269 | d_lookup_done(dentry); | |
1270 | if (alias) { | |
1271 | dput(dentry); | |
1272 | dentry = alias; | |
1273 | } | |
1274 | if (IS_ERR(dentry)) | |
1275 | return PTR_ERR(dentry); | |
1276 | } | |
1277 | if (fc->readdirplus_auto) | |
1278 | set_bit(FUSE_I_INIT_RDPLUS, &get_fuse_inode(inode)->state); | |
1279 | fuse_change_entry_timeout(dentry, o); | |
1280 | ||
1281 | dput(dentry); | |
1282 | return 0; | |
1283 | } | |
1284 | ||
1285 | static int parse_dirplusfile(char *buf, size_t nbytes, struct file *file, | |
1286 | struct dir_context *ctx, u64 attr_version) | |
1287 | { | |
1288 | struct fuse_direntplus *direntplus; | |
1289 | struct fuse_dirent *dirent; | |
1290 | size_t reclen; | |
1291 | int over = 0; | |
1292 | int ret; | |
1293 | ||
1294 | while (nbytes >= FUSE_NAME_OFFSET_DIRENTPLUS) { | |
1295 | direntplus = (struct fuse_direntplus *) buf; | |
1296 | dirent = &direntplus->dirent; | |
1297 | reclen = FUSE_DIRENTPLUS_SIZE(direntplus); | |
1298 | ||
1299 | if (!dirent->namelen || dirent->namelen > FUSE_NAME_MAX) | |
1300 | return -EIO; | |
1301 | if (reclen > nbytes) | |
1302 | break; | |
1303 | if (memchr(dirent->name, '/', dirent->namelen) != NULL) | |
1304 | return -EIO; | |
1305 | ||
1306 | if (!over) { | |
1307 | /* We fill entries into dstbuf only as much as | |
1308 | it can hold. But we still continue iterating | |
1309 | over remaining entries to link them. If not, | |
1310 | we need to send a FORGET for each of those | |
1311 | which we did not link. | |
1312 | */ | |
1313 | over = !dir_emit(ctx, dirent->name, dirent->namelen, | |
1314 | dirent->ino, dirent->type); | |
1315 | ctx->pos = dirent->off; | |
1316 | } | |
1317 | ||
1318 | buf += reclen; | |
1319 | nbytes -= reclen; | |
1320 | ||
1321 | ret = fuse_direntplus_link(file, direntplus, attr_version); | |
1322 | if (ret) | |
1323 | fuse_force_forget(file, direntplus->entry_out.nodeid); | |
1324 | } | |
1325 | ||
1326 | return 0; | |
1327 | } | |
1328 | ||
1329 | static int fuse_readdir(struct file *file, struct dir_context *ctx) | |
1330 | { | |
1331 | int plus, err; | |
1332 | size_t nbytes; | |
1333 | struct page *page; | |
1334 | struct inode *inode = file_inode(file); | |
1335 | struct fuse_conn *fc = get_fuse_conn(inode); | |
1336 | struct fuse_req *req; | |
1337 | u64 attr_version = 0; | |
1338 | ||
1339 | if (is_bad_inode(inode)) | |
1340 | return -EIO; | |
1341 | ||
1342 | req = fuse_get_req(fc, 1); | |
1343 | if (IS_ERR(req)) | |
1344 | return PTR_ERR(req); | |
1345 | ||
1346 | page = alloc_page(GFP_KERNEL); | |
1347 | if (!page) { | |
1348 | fuse_put_request(fc, req); | |
1349 | return -ENOMEM; | |
1350 | } | |
1351 | ||
1352 | plus = fuse_use_readdirplus(inode, ctx); | |
1353 | req->out.argpages = 1; | |
1354 | req->num_pages = 1; | |
1355 | req->pages[0] = page; | |
1356 | req->page_descs[0].length = PAGE_SIZE; | |
1357 | if (plus) { | |
1358 | attr_version = fuse_get_attr_version(fc); | |
1359 | fuse_read_fill(req, file, ctx->pos, PAGE_SIZE, | |
1360 | FUSE_READDIRPLUS); | |
1361 | } else { | |
1362 | fuse_read_fill(req, file, ctx->pos, PAGE_SIZE, | |
1363 | FUSE_READDIR); | |
1364 | } | |
1365 | fuse_lock_inode(inode); | |
1366 | fuse_request_send(fc, req); | |
1367 | fuse_unlock_inode(inode); | |
1368 | nbytes = req->out.args[0].size; | |
1369 | err = req->out.h.error; | |
1370 | fuse_put_request(fc, req); | |
1371 | if (!err) { | |
1372 | if (plus) { | |
1373 | err = parse_dirplusfile(page_address(page), nbytes, | |
1374 | file, ctx, | |
1375 | attr_version); | |
1376 | } else { | |
1377 | err = parse_dirfile(page_address(page), nbytes, file, | |
1378 | ctx); | |
1379 | } | |
1380 | } | |
1381 | ||
1382 | __free_page(page); | |
1383 | fuse_invalidate_atime(inode); | |
1384 | return err; | |
1385 | } | |
1386 | ||
1387 | static const char *fuse_get_link(struct dentry *dentry, | |
1388 | struct inode *inode, | |
1389 | struct delayed_call *done) | |
1390 | { | |
1391 | struct fuse_conn *fc = get_fuse_conn(inode); | |
1392 | FUSE_ARGS(args); | |
1393 | char *link; | |
1394 | ssize_t ret; | |
1395 | ||
1396 | if (!dentry) | |
1397 | return ERR_PTR(-ECHILD); | |
1398 | ||
1399 | link = kmalloc(PAGE_SIZE, GFP_KERNEL); | |
1400 | if (!link) | |
1401 | return ERR_PTR(-ENOMEM); | |
1402 | ||
1403 | args.in.h.opcode = FUSE_READLINK; | |
1404 | args.in.h.nodeid = get_node_id(inode); | |
1405 | args.out.argvar = 1; | |
1406 | args.out.numargs = 1; | |
1407 | args.out.args[0].size = PAGE_SIZE - 1; | |
1408 | args.out.args[0].value = link; | |
1409 | ret = fuse_simple_request(fc, &args); | |
1410 | if (ret < 0) { | |
1411 | kfree(link); | |
1412 | link = ERR_PTR(ret); | |
1413 | } else { | |
1414 | link[ret] = '\0'; | |
1415 | set_delayed_call(done, kfree_link, link); | |
1416 | } | |
1417 | fuse_invalidate_atime(inode); | |
1418 | return link; | |
1419 | } | |
1420 | ||
1421 | static int fuse_dir_open(struct inode *inode, struct file *file) | |
1422 | { | |
1423 | return fuse_open_common(inode, file, true); | |
1424 | } | |
1425 | ||
1426 | static int fuse_dir_release(struct inode *inode, struct file *file) | |
1427 | { | |
1428 | fuse_release_common(file, FUSE_RELEASEDIR); | |
1429 | ||
1430 | return 0; | |
1431 | } | |
1432 | ||
1433 | static int fuse_dir_fsync(struct file *file, loff_t start, loff_t end, | |
1434 | int datasync) | |
1435 | { | |
1436 | return fuse_fsync_common(file, start, end, datasync, 1); | |
1437 | } | |
1438 | ||
1439 | static long fuse_dir_ioctl(struct file *file, unsigned int cmd, | |
1440 | unsigned long arg) | |
1441 | { | |
1442 | struct fuse_conn *fc = get_fuse_conn(file->f_mapping->host); | |
1443 | ||
1444 | /* FUSE_IOCTL_DIR only supported for API version >= 7.18 */ | |
1445 | if (fc->minor < 18) | |
1446 | return -ENOTTY; | |
1447 | ||
1448 | return fuse_ioctl_common(file, cmd, arg, FUSE_IOCTL_DIR); | |
1449 | } | |
1450 | ||
1451 | static long fuse_dir_compat_ioctl(struct file *file, unsigned int cmd, | |
1452 | unsigned long arg) | |
1453 | { | |
1454 | struct fuse_conn *fc = get_fuse_conn(file->f_mapping->host); | |
1455 | ||
1456 | if (fc->minor < 18) | |
1457 | return -ENOTTY; | |
1458 | ||
1459 | return fuse_ioctl_common(file, cmd, arg, | |
1460 | FUSE_IOCTL_COMPAT | FUSE_IOCTL_DIR); | |
1461 | } | |
1462 | ||
1463 | static bool update_mtime(unsigned ivalid, bool trust_local_mtime) | |
1464 | { | |
1465 | /* Always update if mtime is explicitly set */ | |
1466 | if (ivalid & ATTR_MTIME_SET) | |
1467 | return true; | |
1468 | ||
1469 | /* Or if kernel i_mtime is the official one */ | |
1470 | if (trust_local_mtime) | |
1471 | return true; | |
1472 | ||
1473 | /* If it's an open(O_TRUNC) or an ftruncate(), don't update */ | |
1474 | if ((ivalid & ATTR_SIZE) && (ivalid & (ATTR_OPEN | ATTR_FILE))) | |
1475 | return false; | |
1476 | ||
1477 | /* In all other cases update */ | |
1478 | return true; | |
1479 | } | |
1480 | ||
1481 | static void iattr_to_fattr(struct fuse_conn *fc, struct iattr *iattr, | |
1482 | struct fuse_setattr_in *arg, bool trust_local_cmtime) | |
1483 | { | |
1484 | unsigned ivalid = iattr->ia_valid; | |
1485 | ||
1486 | if (ivalid & ATTR_MODE) | |
1487 | arg->valid |= FATTR_MODE, arg->mode = iattr->ia_mode; | |
1488 | if (ivalid & ATTR_UID) | |
1489 | arg->valid |= FATTR_UID, arg->uid = from_kuid(fc->user_ns, iattr->ia_uid); | |
1490 | if (ivalid & ATTR_GID) | |
1491 | arg->valid |= FATTR_GID, arg->gid = from_kgid(fc->user_ns, iattr->ia_gid); | |
1492 | if (ivalid & ATTR_SIZE) | |
1493 | arg->valid |= FATTR_SIZE, arg->size = iattr->ia_size; | |
1494 | if (ivalid & ATTR_ATIME) { | |
1495 | arg->valid |= FATTR_ATIME; | |
1496 | arg->atime = iattr->ia_atime.tv_sec; | |
1497 | arg->atimensec = iattr->ia_atime.tv_nsec; | |
1498 | if (!(ivalid & ATTR_ATIME_SET)) | |
1499 | arg->valid |= FATTR_ATIME_NOW; | |
1500 | } | |
1501 | if ((ivalid & ATTR_MTIME) && update_mtime(ivalid, trust_local_cmtime)) { | |
1502 | arg->valid |= FATTR_MTIME; | |
1503 | arg->mtime = iattr->ia_mtime.tv_sec; | |
1504 | arg->mtimensec = iattr->ia_mtime.tv_nsec; | |
1505 | if (!(ivalid & ATTR_MTIME_SET) && !trust_local_cmtime) | |
1506 | arg->valid |= FATTR_MTIME_NOW; | |
1507 | } | |
1508 | if ((ivalid & ATTR_CTIME) && trust_local_cmtime) { | |
1509 | arg->valid |= FATTR_CTIME; | |
1510 | arg->ctime = iattr->ia_ctime.tv_sec; | |
1511 | arg->ctimensec = iattr->ia_ctime.tv_nsec; | |
1512 | } | |
1513 | } | |
1514 | ||
1515 | /* | |
1516 | * Prevent concurrent writepages on inode | |
1517 | * | |
1518 | * This is done by adding a negative bias to the inode write counter | |
1519 | * and waiting for all pending writes to finish. | |
1520 | */ | |
1521 | void fuse_set_nowrite(struct inode *inode) | |
1522 | { | |
1523 | struct fuse_conn *fc = get_fuse_conn(inode); | |
1524 | struct fuse_inode *fi = get_fuse_inode(inode); | |
1525 | ||
1526 | BUG_ON(!inode_is_locked(inode)); | |
1527 | ||
1528 | spin_lock(&fc->lock); | |
1529 | BUG_ON(fi->writectr < 0); | |
1530 | fi->writectr += FUSE_NOWRITE; | |
1531 | spin_unlock(&fc->lock); | |
1532 | wait_event(fi->page_waitq, fi->writectr == FUSE_NOWRITE); | |
1533 | } | |
1534 | ||
1535 | /* | |
1536 | * Allow writepages on inode | |
1537 | * | |
1538 | * Remove the bias from the writecounter and send any queued | |
1539 | * writepages. | |
1540 | */ | |
1541 | static void __fuse_release_nowrite(struct inode *inode) | |
1542 | { | |
1543 | struct fuse_inode *fi = get_fuse_inode(inode); | |
1544 | ||
1545 | BUG_ON(fi->writectr != FUSE_NOWRITE); | |
1546 | fi->writectr = 0; | |
1547 | fuse_flush_writepages(inode); | |
1548 | } | |
1549 | ||
1550 | void fuse_release_nowrite(struct inode *inode) | |
1551 | { | |
1552 | struct fuse_conn *fc = get_fuse_conn(inode); | |
1553 | ||
1554 | spin_lock(&fc->lock); | |
1555 | __fuse_release_nowrite(inode); | |
1556 | spin_unlock(&fc->lock); | |
1557 | } | |
1558 | ||
1559 | static void fuse_setattr_fill(struct fuse_conn *fc, struct fuse_args *args, | |
1560 | struct inode *inode, | |
1561 | struct fuse_setattr_in *inarg_p, | |
1562 | struct fuse_attr_out *outarg_p) | |
1563 | { | |
1564 | args->in.h.opcode = FUSE_SETATTR; | |
1565 | args->in.h.nodeid = get_node_id(inode); | |
1566 | args->in.numargs = 1; | |
1567 | args->in.args[0].size = sizeof(*inarg_p); | |
1568 | args->in.args[0].value = inarg_p; | |
1569 | args->out.numargs = 1; | |
1570 | args->out.args[0].size = sizeof(*outarg_p); | |
1571 | args->out.args[0].value = outarg_p; | |
1572 | } | |
1573 | ||
1574 | /* | |
1575 | * Flush inode->i_mtime to the server | |
1576 | */ | |
1577 | int fuse_flush_times(struct inode *inode, struct fuse_file *ff) | |
1578 | { | |
1579 | struct fuse_conn *fc = get_fuse_conn(inode); | |
1580 | FUSE_ARGS(args); | |
1581 | struct fuse_setattr_in inarg; | |
1582 | struct fuse_attr_out outarg; | |
1583 | ||
1584 | memset(&inarg, 0, sizeof(inarg)); | |
1585 | memset(&outarg, 0, sizeof(outarg)); | |
1586 | ||
1587 | inarg.valid = FATTR_MTIME; | |
1588 | inarg.mtime = inode->i_mtime.tv_sec; | |
1589 | inarg.mtimensec = inode->i_mtime.tv_nsec; | |
1590 | if (fc->minor >= 23) { | |
1591 | inarg.valid |= FATTR_CTIME; | |
1592 | inarg.ctime = inode->i_ctime.tv_sec; | |
1593 | inarg.ctimensec = inode->i_ctime.tv_nsec; | |
1594 | } | |
1595 | if (ff) { | |
1596 | inarg.valid |= FATTR_FH; | |
1597 | inarg.fh = ff->fh; | |
1598 | } | |
1599 | fuse_setattr_fill(fc, &args, inode, &inarg, &outarg); | |
1600 | ||
1601 | return fuse_simple_request(fc, &args); | |
1602 | } | |
1603 | ||
1604 | /* | |
1605 | * Set attributes, and at the same time refresh them. | |
1606 | * | |
1607 | * Truncation is slightly complicated, because the 'truncate' request | |
1608 | * may fail, in which case we don't want to touch the mapping. | |
1609 | * vmtruncate() doesn't allow for this case, so do the rlimit checking | |
1610 | * and the actual truncation by hand. | |
1611 | */ | |
1612 | int fuse_do_setattr(struct dentry *dentry, struct iattr *attr, | |
1613 | struct file *file) | |
1614 | { | |
1615 | struct inode *inode = d_inode(dentry); | |
1616 | struct fuse_conn *fc = get_fuse_conn(inode); | |
1617 | struct fuse_inode *fi = get_fuse_inode(inode); | |
1618 | FUSE_ARGS(args); | |
1619 | struct fuse_setattr_in inarg; | |
1620 | struct fuse_attr_out outarg; | |
1621 | bool is_truncate = false; | |
1622 | bool is_wb = fc->writeback_cache; | |
1623 | loff_t oldsize; | |
1624 | int err; | |
1625 | bool trust_local_cmtime = is_wb && S_ISREG(inode->i_mode); | |
1626 | ||
1627 | if (!fc->default_permissions) | |
1628 | attr->ia_valid |= ATTR_FORCE; | |
1629 | ||
1630 | err = setattr_prepare(dentry, attr); | |
1631 | if (err) | |
1632 | return err; | |
1633 | ||
1634 | if (attr->ia_valid & ATTR_OPEN) { | |
1635 | if (fc->atomic_o_trunc) | |
1636 | return 0; | |
1637 | file = NULL; | |
1638 | } | |
1639 | ||
1640 | if (attr->ia_valid & ATTR_SIZE) | |
1641 | is_truncate = true; | |
1642 | ||
1643 | if (is_truncate) { | |
1644 | fuse_set_nowrite(inode); | |
1645 | set_bit(FUSE_I_SIZE_UNSTABLE, &fi->state); | |
1646 | if (trust_local_cmtime && attr->ia_size != inode->i_size) | |
1647 | attr->ia_valid |= ATTR_MTIME | ATTR_CTIME; | |
1648 | } | |
1649 | ||
1650 | memset(&inarg, 0, sizeof(inarg)); | |
1651 | memset(&outarg, 0, sizeof(outarg)); | |
1652 | iattr_to_fattr(fc, attr, &inarg, trust_local_cmtime); | |
1653 | if (file) { | |
1654 | struct fuse_file *ff = file->private_data; | |
1655 | inarg.valid |= FATTR_FH; | |
1656 | inarg.fh = ff->fh; | |
1657 | } | |
1658 | if (attr->ia_valid & ATTR_SIZE) { | |
1659 | /* For mandatory locking in truncate */ | |
1660 | inarg.valid |= FATTR_LOCKOWNER; | |
1661 | inarg.lock_owner = fuse_lock_owner_id(fc, current->files); | |
1662 | } | |
1663 | fuse_setattr_fill(fc, &args, inode, &inarg, &outarg); | |
1664 | err = fuse_simple_request(fc, &args); | |
1665 | if (err) { | |
1666 | if (err == -EINTR) | |
1667 | fuse_invalidate_attr(inode); | |
1668 | goto error; | |
1669 | } | |
1670 | ||
1671 | if ((inode->i_mode ^ outarg.attr.mode) & S_IFMT) { | |
1672 | make_bad_inode(inode); | |
1673 | err = -EIO; | |
1674 | goto error; | |
1675 | } | |
1676 | ||
1677 | spin_lock(&fc->lock); | |
1678 | /* the kernel maintains i_mtime locally */ | |
1679 | if (trust_local_cmtime) { | |
1680 | if (attr->ia_valid & ATTR_MTIME) | |
1681 | inode->i_mtime = attr->ia_mtime; | |
1682 | if (attr->ia_valid & ATTR_CTIME) | |
1683 | inode->i_ctime = attr->ia_ctime; | |
1684 | /* FIXME: clear I_DIRTY_SYNC? */ | |
1685 | } | |
1686 | ||
1687 | fuse_change_attributes_common(inode, &outarg.attr, | |
1688 | attr_timeout(&outarg)); | |
1689 | oldsize = inode->i_size; | |
1690 | /* see the comment in fuse_change_attributes() */ | |
1691 | if (!is_wb || is_truncate || !S_ISREG(inode->i_mode)) | |
1692 | i_size_write(inode, outarg.attr.size); | |
1693 | ||
1694 | if (is_truncate) { | |
1695 | /* NOTE: this may release/reacquire fc->lock */ | |
1696 | __fuse_release_nowrite(inode); | |
1697 | } | |
1698 | spin_unlock(&fc->lock); | |
1699 | ||
1700 | /* | |
1701 | * Only call invalidate_inode_pages2() after removing | |
1702 | * FUSE_NOWRITE, otherwise fuse_launder_page() would deadlock. | |
1703 | */ | |
1704 | if ((is_truncate || !is_wb) && | |
1705 | S_ISREG(inode->i_mode) && oldsize != outarg.attr.size) { | |
1706 | truncate_pagecache(inode, outarg.attr.size); | |
1707 | invalidate_inode_pages2(inode->i_mapping); | |
1708 | } | |
1709 | ||
1710 | clear_bit(FUSE_I_SIZE_UNSTABLE, &fi->state); | |
1711 | return 0; | |
1712 | ||
1713 | error: | |
1714 | if (is_truncate) | |
1715 | fuse_release_nowrite(inode); | |
1716 | ||
1717 | clear_bit(FUSE_I_SIZE_UNSTABLE, &fi->state); | |
1718 | return err; | |
1719 | } | |
1720 | ||
1721 | static int fuse_setattr(struct dentry *entry, struct iattr *attr) | |
1722 | { | |
1723 | struct inode *inode = d_inode(entry); | |
1724 | struct fuse_conn *fc = get_fuse_conn(inode); | |
1725 | struct file *file = (attr->ia_valid & ATTR_FILE) ? attr->ia_file : NULL; | |
1726 | int ret; | |
1727 | ||
1728 | if (!fuse_allow_current_process(get_fuse_conn(inode))) | |
1729 | return -EACCES; | |
1730 | ||
1731 | if (attr->ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID)) { | |
1732 | attr->ia_valid &= ~(ATTR_KILL_SUID | ATTR_KILL_SGID | | |
1733 | ATTR_MODE); | |
1734 | ||
1735 | /* | |
1736 | * The only sane way to reliably kill suid/sgid is to do it in | |
1737 | * the userspace filesystem | |
1738 | * | |
1739 | * This should be done on write(), truncate() and chown(). | |
1740 | */ | |
1741 | if (!fc->handle_killpriv) { | |
1742 | /* | |
1743 | * ia_mode calculation may have used stale i_mode. | |
1744 | * Refresh and recalculate. | |
1745 | */ | |
1746 | ret = fuse_do_getattr(inode, NULL, file); | |
1747 | if (ret) | |
1748 | return ret; | |
1749 | ||
1750 | attr->ia_mode = inode->i_mode; | |
1751 | if (inode->i_mode & S_ISUID) { | |
1752 | attr->ia_valid |= ATTR_MODE; | |
1753 | attr->ia_mode &= ~S_ISUID; | |
1754 | } | |
1755 | if ((inode->i_mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP)) { | |
1756 | attr->ia_valid |= ATTR_MODE; | |
1757 | attr->ia_mode &= ~S_ISGID; | |
1758 | } | |
1759 | } | |
1760 | } | |
1761 | if (!attr->ia_valid) | |
1762 | return 0; | |
1763 | ||
1764 | ret = fuse_do_setattr(entry, attr, file); | |
1765 | if (!ret) { | |
1766 | /* | |
1767 | * If filesystem supports acls it may have updated acl xattrs in | |
1768 | * the filesystem, so forget cached acls for the inode. | |
1769 | */ | |
1770 | if (fc->posix_acl) | |
1771 | forget_all_cached_acls(inode); | |
1772 | ||
1773 | /* Directory mode changed, may need to revalidate access */ | |
1774 | if (d_is_dir(entry) && (attr->ia_valid & ATTR_MODE)) | |
1775 | fuse_invalidate_entry_cache(entry); | |
1776 | } | |
1777 | return ret; | |
1778 | } | |
1779 | ||
1780 | static int fuse_getattr(struct vfsmount *mnt, struct dentry *entry, | |
1781 | struct kstat *stat) | |
1782 | { | |
1783 | struct inode *inode = d_inode(entry); | |
1784 | struct fuse_conn *fc = get_fuse_conn(inode); | |
1785 | ||
1786 | if (!fuse_allow_current_process(fc)) | |
1787 | return -EACCES; | |
1788 | ||
1789 | return fuse_update_attributes(inode, stat, NULL, NULL); | |
1790 | } | |
1791 | ||
1792 | static const struct inode_operations fuse_dir_inode_operations = { | |
1793 | .lookup = fuse_lookup, | |
1794 | .mkdir = fuse_mkdir, | |
1795 | .symlink = fuse_symlink, | |
1796 | .unlink = fuse_unlink, | |
1797 | .rmdir = fuse_rmdir, | |
1798 | .rename = fuse_rename2, | |
1799 | .link = fuse_link, | |
1800 | .setattr = fuse_setattr, | |
1801 | .create = fuse_create, | |
1802 | .atomic_open = fuse_atomic_open, | |
1803 | .mknod = fuse_mknod, | |
1804 | .permission = fuse_permission, | |
1805 | .getattr = fuse_getattr, | |
1806 | .listxattr = fuse_listxattr, | |
1807 | .get_acl = fuse_get_acl, | |
1808 | .set_acl = fuse_set_acl, | |
1809 | }; | |
1810 | ||
1811 | static const struct file_operations fuse_dir_operations = { | |
1812 | .llseek = generic_file_llseek, | |
1813 | .read = generic_read_dir, | |
1814 | .iterate_shared = fuse_readdir, | |
1815 | .open = fuse_dir_open, | |
1816 | .release = fuse_dir_release, | |
1817 | .fsync = fuse_dir_fsync, | |
1818 | .unlocked_ioctl = fuse_dir_ioctl, | |
1819 | .compat_ioctl = fuse_dir_compat_ioctl, | |
1820 | }; | |
1821 | ||
1822 | static const struct inode_operations fuse_common_inode_operations = { | |
1823 | .setattr = fuse_setattr, | |
1824 | .permission = fuse_permission, | |
1825 | .getattr = fuse_getattr, | |
1826 | .listxattr = fuse_listxattr, | |
1827 | .get_acl = fuse_get_acl, | |
1828 | .set_acl = fuse_set_acl, | |
1829 | }; | |
1830 | ||
1831 | static const struct inode_operations fuse_symlink_inode_operations = { | |
1832 | .setattr = fuse_setattr, | |
1833 | .get_link = fuse_get_link, | |
1834 | .getattr = fuse_getattr, | |
1835 | .listxattr = fuse_listxattr, | |
1836 | }; | |
1837 | ||
1838 | void fuse_init_common(struct inode *inode) | |
1839 | { | |
1840 | inode->i_op = &fuse_common_inode_operations; | |
1841 | } | |
1842 | ||
1843 | void fuse_init_dir(struct inode *inode) | |
1844 | { | |
1845 | inode->i_op = &fuse_dir_inode_operations; | |
1846 | inode->i_fop = &fuse_dir_operations; | |
1847 | } | |
1848 | ||
1849 | void fuse_init_symlink(struct inode *inode) | |
1850 | { | |
1851 | inode->i_op = &fuse_symlink_inode_operations; | |
1852 | } |