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1 | /* | |
2 | FUSE: Filesystem in Userspace | |
3 | Copyright (C) 2001-2006 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/gfp.h> | |
14 | #include <linux/sched.h> | |
15 | #include <linux/namei.h> | |
16 | ||
17 | #if BITS_PER_LONG >= 64 | |
18 | static inline void fuse_dentry_settime(struct dentry *entry, u64 time) | |
19 | { | |
20 | entry->d_time = time; | |
21 | } | |
22 | ||
23 | static inline u64 fuse_dentry_time(struct dentry *entry) | |
24 | { | |
25 | return entry->d_time; | |
26 | } | |
27 | #else | |
28 | /* | |
29 | * On 32 bit archs store the high 32 bits of time in d_fsdata | |
30 | */ | |
31 | static void fuse_dentry_settime(struct dentry *entry, u64 time) | |
32 | { | |
33 | entry->d_time = time; | |
34 | entry->d_fsdata = (void *) (unsigned long) (time >> 32); | |
35 | } | |
36 | ||
37 | static u64 fuse_dentry_time(struct dentry *entry) | |
38 | { | |
39 | return (u64) entry->d_time + | |
40 | ((u64) (unsigned long) entry->d_fsdata << 32); | |
41 | } | |
42 | #endif | |
43 | ||
44 | /* | |
45 | * FUSE caches dentries and attributes with separate timeout. The | |
46 | * time in jiffies until the dentry/attributes are valid is stored in | |
47 | * dentry->d_time and fuse_inode->i_time respectively. | |
48 | */ | |
49 | ||
50 | /* | |
51 | * Calculate the time in jiffies until a dentry/attributes are valid | |
52 | */ | |
53 | static u64 time_to_jiffies(unsigned long sec, unsigned long nsec) | |
54 | { | |
55 | if (sec || nsec) { | |
56 | struct timespec ts = {sec, nsec}; | |
57 | return get_jiffies_64() + timespec_to_jiffies(&ts); | |
58 | } else | |
59 | return 0; | |
60 | } | |
61 | ||
62 | /* | |
63 | * Set dentry and possibly attribute timeouts from the lookup/mk* | |
64 | * replies | |
65 | */ | |
66 | static void fuse_change_entry_timeout(struct dentry *entry, | |
67 | struct fuse_entry_out *o) | |
68 | { | |
69 | fuse_dentry_settime(entry, | |
70 | time_to_jiffies(o->entry_valid, o->entry_valid_nsec)); | |
71 | } | |
72 | ||
73 | static u64 attr_timeout(struct fuse_attr_out *o) | |
74 | { | |
75 | return time_to_jiffies(o->attr_valid, o->attr_valid_nsec); | |
76 | } | |
77 | ||
78 | static u64 entry_attr_timeout(struct fuse_entry_out *o) | |
79 | { | |
80 | return time_to_jiffies(o->attr_valid, o->attr_valid_nsec); | |
81 | } | |
82 | ||
83 | /* | |
84 | * Mark the attributes as stale, so that at the next call to | |
85 | * ->getattr() they will be fetched from userspace | |
86 | */ | |
87 | void fuse_invalidate_attr(struct inode *inode) | |
88 | { | |
89 | get_fuse_inode(inode)->i_time = 0; | |
90 | } | |
91 | ||
92 | /* | |
93 | * Just mark the entry as stale, so that a next attempt to look it up | |
94 | * will result in a new lookup call to userspace | |
95 | * | |
96 | * This is called when a dentry is about to become negative and the | |
97 | * timeout is unknown (unlink, rmdir, rename and in some cases | |
98 | * lookup) | |
99 | */ | |
100 | static void fuse_invalidate_entry_cache(struct dentry *entry) | |
101 | { | |
102 | fuse_dentry_settime(entry, 0); | |
103 | } | |
104 | ||
105 | /* | |
106 | * Same as fuse_invalidate_entry_cache(), but also try to remove the | |
107 | * dentry from the hash | |
108 | */ | |
109 | static void fuse_invalidate_entry(struct dentry *entry) | |
110 | { | |
111 | d_invalidate(entry); | |
112 | fuse_invalidate_entry_cache(entry); | |
113 | } | |
114 | ||
115 | static void fuse_lookup_init(struct fuse_req *req, struct inode *dir, | |
116 | struct dentry *entry, | |
117 | struct fuse_entry_out *outarg) | |
118 | { | |
119 | struct fuse_conn *fc = get_fuse_conn(dir); | |
120 | ||
121 | memset(outarg, 0, sizeof(struct fuse_entry_out)); | |
122 | req->in.h.opcode = FUSE_LOOKUP; | |
123 | req->in.h.nodeid = get_node_id(dir); | |
124 | req->in.numargs = 1; | |
125 | req->in.args[0].size = entry->d_name.len + 1; | |
126 | req->in.args[0].value = entry->d_name.name; | |
127 | req->out.numargs = 1; | |
128 | if (fc->minor < 9) | |
129 | req->out.args[0].size = FUSE_COMPAT_ENTRY_OUT_SIZE; | |
130 | else | |
131 | req->out.args[0].size = sizeof(struct fuse_entry_out); | |
132 | req->out.args[0].value = outarg; | |
133 | } | |
134 | ||
135 | u64 fuse_get_attr_version(struct fuse_conn *fc) | |
136 | { | |
137 | u64 curr_version; | |
138 | ||
139 | /* | |
140 | * The spin lock isn't actually needed on 64bit archs, but we | |
141 | * don't yet care too much about such optimizations. | |
142 | */ | |
143 | spin_lock(&fc->lock); | |
144 | curr_version = fc->attr_version; | |
145 | spin_unlock(&fc->lock); | |
146 | ||
147 | return curr_version; | |
148 | } | |
149 | ||
150 | /* | |
151 | * Check whether the dentry is still valid | |
152 | * | |
153 | * If the entry validity timeout has expired and the dentry is | |
154 | * positive, try to redo the lookup. If the lookup results in a | |
155 | * different inode, then let the VFS invalidate the dentry and redo | |
156 | * the lookup once more. If the lookup results in the same inode, | |
157 | * then refresh the attributes, timeouts and mark the dentry valid. | |
158 | */ | |
159 | static int fuse_dentry_revalidate(struct dentry *entry, struct nameidata *nd) | |
160 | { | |
161 | struct inode *inode = entry->d_inode; | |
162 | ||
163 | if (inode && is_bad_inode(inode)) | |
164 | return 0; | |
165 | else if (fuse_dentry_time(entry) < get_jiffies_64()) { | |
166 | int err; | |
167 | struct fuse_entry_out outarg; | |
168 | struct fuse_conn *fc; | |
169 | struct fuse_req *req; | |
170 | struct fuse_req *forget_req; | |
171 | struct dentry *parent; | |
172 | u64 attr_version; | |
173 | ||
174 | /* For negative dentries, always do a fresh lookup */ | |
175 | if (!inode) | |
176 | return 0; | |
177 | ||
178 | fc = get_fuse_conn(inode); | |
179 | req = fuse_get_req(fc); | |
180 | if (IS_ERR(req)) | |
181 | return 0; | |
182 | ||
183 | forget_req = fuse_get_req(fc); | |
184 | if (IS_ERR(forget_req)) { | |
185 | fuse_put_request(fc, req); | |
186 | return 0; | |
187 | } | |
188 | ||
189 | attr_version = fuse_get_attr_version(fc); | |
190 | ||
191 | parent = dget_parent(entry); | |
192 | fuse_lookup_init(req, parent->d_inode, entry, &outarg); | |
193 | request_send(fc, req); | |
194 | dput(parent); | |
195 | err = req->out.h.error; | |
196 | fuse_put_request(fc, req); | |
197 | /* Zero nodeid is same as -ENOENT */ | |
198 | if (!err && !outarg.nodeid) | |
199 | err = -ENOENT; | |
200 | if (!err) { | |
201 | struct fuse_inode *fi = get_fuse_inode(inode); | |
202 | if (outarg.nodeid != get_node_id(inode)) { | |
203 | fuse_send_forget(fc, forget_req, | |
204 | outarg.nodeid, 1); | |
205 | return 0; | |
206 | } | |
207 | spin_lock(&fc->lock); | |
208 | fi->nlookup ++; | |
209 | spin_unlock(&fc->lock); | |
210 | } | |
211 | fuse_put_request(fc, forget_req); | |
212 | if (err || (outarg.attr.mode ^ inode->i_mode) & S_IFMT) | |
213 | return 0; | |
214 | ||
215 | fuse_change_attributes(inode, &outarg.attr, | |
216 | entry_attr_timeout(&outarg), | |
217 | attr_version); | |
218 | fuse_change_entry_timeout(entry, &outarg); | |
219 | } | |
220 | return 1; | |
221 | } | |
222 | ||
223 | static int invalid_nodeid(u64 nodeid) | |
224 | { | |
225 | return !nodeid || nodeid == FUSE_ROOT_ID; | |
226 | } | |
227 | ||
228 | static struct dentry_operations fuse_dentry_operations = { | |
229 | .d_revalidate = fuse_dentry_revalidate, | |
230 | }; | |
231 | ||
232 | int fuse_valid_type(int m) | |
233 | { | |
234 | return S_ISREG(m) || S_ISDIR(m) || S_ISLNK(m) || S_ISCHR(m) || | |
235 | S_ISBLK(m) || S_ISFIFO(m) || S_ISSOCK(m); | |
236 | } | |
237 | ||
238 | /* | |
239 | * Add a directory inode to a dentry, ensuring that no other dentry | |
240 | * refers to this inode. Called with fc->inst_mutex. | |
241 | */ | |
242 | static struct dentry *fuse_d_add_directory(struct dentry *entry, | |
243 | struct inode *inode) | |
244 | { | |
245 | struct dentry *alias = d_find_alias(inode); | |
246 | if (alias && !(alias->d_flags & DCACHE_DISCONNECTED)) { | |
247 | /* This tries to shrink the subtree below alias */ | |
248 | fuse_invalidate_entry(alias); | |
249 | dput(alias); | |
250 | if (!list_empty(&inode->i_dentry)) | |
251 | return ERR_PTR(-EBUSY); | |
252 | } else { | |
253 | dput(alias); | |
254 | } | |
255 | return d_splice_alias(inode, entry); | |
256 | } | |
257 | ||
258 | static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry, | |
259 | struct nameidata *nd) | |
260 | { | |
261 | int err; | |
262 | struct fuse_entry_out outarg; | |
263 | struct inode *inode = NULL; | |
264 | struct dentry *newent; | |
265 | struct fuse_conn *fc = get_fuse_conn(dir); | |
266 | struct fuse_req *req; | |
267 | struct fuse_req *forget_req; | |
268 | u64 attr_version; | |
269 | ||
270 | if (entry->d_name.len > FUSE_NAME_MAX) | |
271 | return ERR_PTR(-ENAMETOOLONG); | |
272 | ||
273 | req = fuse_get_req(fc); | |
274 | if (IS_ERR(req)) | |
275 | return ERR_CAST(req); | |
276 | ||
277 | forget_req = fuse_get_req(fc); | |
278 | if (IS_ERR(forget_req)) { | |
279 | fuse_put_request(fc, req); | |
280 | return ERR_CAST(forget_req); | |
281 | } | |
282 | ||
283 | attr_version = fuse_get_attr_version(fc); | |
284 | ||
285 | fuse_lookup_init(req, dir, entry, &outarg); | |
286 | request_send(fc, req); | |
287 | err = req->out.h.error; | |
288 | fuse_put_request(fc, req); | |
289 | /* Zero nodeid is same as -ENOENT, but with valid timeout */ | |
290 | if (!err && outarg.nodeid && | |
291 | (invalid_nodeid(outarg.nodeid) || | |
292 | !fuse_valid_type(outarg.attr.mode))) | |
293 | err = -EIO; | |
294 | if (!err && outarg.nodeid) { | |
295 | inode = fuse_iget(dir->i_sb, outarg.nodeid, outarg.generation, | |
296 | &outarg.attr, entry_attr_timeout(&outarg), | |
297 | attr_version); | |
298 | if (!inode) { | |
299 | fuse_send_forget(fc, forget_req, outarg.nodeid, 1); | |
300 | return ERR_PTR(-ENOMEM); | |
301 | } | |
302 | } | |
303 | fuse_put_request(fc, forget_req); | |
304 | if (err && err != -ENOENT) | |
305 | return ERR_PTR(err); | |
306 | ||
307 | if (inode && S_ISDIR(inode->i_mode)) { | |
308 | mutex_lock(&fc->inst_mutex); | |
309 | newent = fuse_d_add_directory(entry, inode); | |
310 | mutex_unlock(&fc->inst_mutex); | |
311 | if (IS_ERR(newent)) { | |
312 | iput(inode); | |
313 | return newent; | |
314 | } | |
315 | } else | |
316 | newent = d_splice_alias(inode, entry); | |
317 | ||
318 | entry = newent ? newent : entry; | |
319 | entry->d_op = &fuse_dentry_operations; | |
320 | if (!err) | |
321 | fuse_change_entry_timeout(entry, &outarg); | |
322 | else | |
323 | fuse_invalidate_entry_cache(entry); | |
324 | return newent; | |
325 | } | |
326 | ||
327 | /* | |
328 | * Synchronous release for the case when something goes wrong in CREATE_OPEN | |
329 | */ | |
330 | static void fuse_sync_release(struct fuse_conn *fc, struct fuse_file *ff, | |
331 | u64 nodeid, int flags) | |
332 | { | |
333 | fuse_release_fill(ff, nodeid, flags, FUSE_RELEASE); | |
334 | ff->reserved_req->force = 1; | |
335 | request_send(fc, ff->reserved_req); | |
336 | fuse_put_request(fc, ff->reserved_req); | |
337 | kfree(ff); | |
338 | } | |
339 | ||
340 | /* | |
341 | * Atomic create+open operation | |
342 | * | |
343 | * If the filesystem doesn't support this, then fall back to separate | |
344 | * 'mknod' + 'open' requests. | |
345 | */ | |
346 | static int fuse_create_open(struct inode *dir, struct dentry *entry, int mode, | |
347 | struct nameidata *nd) | |
348 | { | |
349 | int err; | |
350 | struct inode *inode; | |
351 | struct fuse_conn *fc = get_fuse_conn(dir); | |
352 | struct fuse_req *req; | |
353 | struct fuse_req *forget_req; | |
354 | struct fuse_open_in inarg; | |
355 | struct fuse_open_out outopen; | |
356 | struct fuse_entry_out outentry; | |
357 | struct fuse_file *ff; | |
358 | struct file *file; | |
359 | int flags = nd->intent.open.flags - 1; | |
360 | ||
361 | if (fc->no_create) | |
362 | return -ENOSYS; | |
363 | ||
364 | forget_req = fuse_get_req(fc); | |
365 | if (IS_ERR(forget_req)) | |
366 | return PTR_ERR(forget_req); | |
367 | ||
368 | req = fuse_get_req(fc); | |
369 | err = PTR_ERR(req); | |
370 | if (IS_ERR(req)) | |
371 | goto out_put_forget_req; | |
372 | ||
373 | err = -ENOMEM; | |
374 | ff = fuse_file_alloc(); | |
375 | if (!ff) | |
376 | goto out_put_request; | |
377 | ||
378 | flags &= ~O_NOCTTY; | |
379 | memset(&inarg, 0, sizeof(inarg)); | |
380 | memset(&outentry, 0, sizeof(outentry)); | |
381 | inarg.flags = flags; | |
382 | inarg.mode = mode; | |
383 | req->in.h.opcode = FUSE_CREATE; | |
384 | req->in.h.nodeid = get_node_id(dir); | |
385 | req->in.numargs = 2; | |
386 | req->in.args[0].size = sizeof(inarg); | |
387 | req->in.args[0].value = &inarg; | |
388 | req->in.args[1].size = entry->d_name.len + 1; | |
389 | req->in.args[1].value = entry->d_name.name; | |
390 | req->out.numargs = 2; | |
391 | if (fc->minor < 9) | |
392 | req->out.args[0].size = FUSE_COMPAT_ENTRY_OUT_SIZE; | |
393 | else | |
394 | req->out.args[0].size = sizeof(outentry); | |
395 | req->out.args[0].value = &outentry; | |
396 | req->out.args[1].size = sizeof(outopen); | |
397 | req->out.args[1].value = &outopen; | |
398 | request_send(fc, req); | |
399 | err = req->out.h.error; | |
400 | if (err) { | |
401 | if (err == -ENOSYS) | |
402 | fc->no_create = 1; | |
403 | goto out_free_ff; | |
404 | } | |
405 | ||
406 | err = -EIO; | |
407 | if (!S_ISREG(outentry.attr.mode) || invalid_nodeid(outentry.nodeid)) | |
408 | goto out_free_ff; | |
409 | ||
410 | fuse_put_request(fc, req); | |
411 | inode = fuse_iget(dir->i_sb, outentry.nodeid, outentry.generation, | |
412 | &outentry.attr, entry_attr_timeout(&outentry), 0); | |
413 | if (!inode) { | |
414 | flags &= ~(O_CREAT | O_EXCL | O_TRUNC); | |
415 | ff->fh = outopen.fh; | |
416 | fuse_sync_release(fc, ff, outentry.nodeid, flags); | |
417 | fuse_send_forget(fc, forget_req, outentry.nodeid, 1); | |
418 | return -ENOMEM; | |
419 | } | |
420 | fuse_put_request(fc, forget_req); | |
421 | d_instantiate(entry, inode); | |
422 | fuse_change_entry_timeout(entry, &outentry); | |
423 | fuse_invalidate_attr(dir); | |
424 | file = lookup_instantiate_filp(nd, entry, generic_file_open); | |
425 | if (IS_ERR(file)) { | |
426 | ff->fh = outopen.fh; | |
427 | fuse_sync_release(fc, ff, outentry.nodeid, flags); | |
428 | return PTR_ERR(file); | |
429 | } | |
430 | fuse_finish_open(inode, file, ff, &outopen); | |
431 | return 0; | |
432 | ||
433 | out_free_ff: | |
434 | fuse_file_free(ff); | |
435 | out_put_request: | |
436 | fuse_put_request(fc, req); | |
437 | out_put_forget_req: | |
438 | fuse_put_request(fc, forget_req); | |
439 | return err; | |
440 | } | |
441 | ||
442 | /* | |
443 | * Code shared between mknod, mkdir, symlink and link | |
444 | */ | |
445 | static int create_new_entry(struct fuse_conn *fc, struct fuse_req *req, | |
446 | struct inode *dir, struct dentry *entry, | |
447 | int mode) | |
448 | { | |
449 | struct fuse_entry_out outarg; | |
450 | struct inode *inode; | |
451 | int err; | |
452 | struct fuse_req *forget_req; | |
453 | ||
454 | forget_req = fuse_get_req(fc); | |
455 | if (IS_ERR(forget_req)) { | |
456 | fuse_put_request(fc, req); | |
457 | return PTR_ERR(forget_req); | |
458 | } | |
459 | ||
460 | memset(&outarg, 0, sizeof(outarg)); | |
461 | req->in.h.nodeid = get_node_id(dir); | |
462 | req->out.numargs = 1; | |
463 | if (fc->minor < 9) | |
464 | req->out.args[0].size = FUSE_COMPAT_ENTRY_OUT_SIZE; | |
465 | else | |
466 | req->out.args[0].size = sizeof(outarg); | |
467 | req->out.args[0].value = &outarg; | |
468 | request_send(fc, req); | |
469 | err = req->out.h.error; | |
470 | fuse_put_request(fc, req); | |
471 | if (err) | |
472 | goto out_put_forget_req; | |
473 | ||
474 | err = -EIO; | |
475 | if (invalid_nodeid(outarg.nodeid)) | |
476 | goto out_put_forget_req; | |
477 | ||
478 | if ((outarg.attr.mode ^ mode) & S_IFMT) | |
479 | goto out_put_forget_req; | |
480 | ||
481 | inode = fuse_iget(dir->i_sb, outarg.nodeid, outarg.generation, | |
482 | &outarg.attr, entry_attr_timeout(&outarg), 0); | |
483 | if (!inode) { | |
484 | fuse_send_forget(fc, forget_req, outarg.nodeid, 1); | |
485 | return -ENOMEM; | |
486 | } | |
487 | fuse_put_request(fc, forget_req); | |
488 | ||
489 | if (S_ISDIR(inode->i_mode)) { | |
490 | struct dentry *alias; | |
491 | mutex_lock(&fc->inst_mutex); | |
492 | alias = d_find_alias(inode); | |
493 | if (alias) { | |
494 | /* New directory must have moved since mkdir */ | |
495 | mutex_unlock(&fc->inst_mutex); | |
496 | dput(alias); | |
497 | iput(inode); | |
498 | return -EBUSY; | |
499 | } | |
500 | d_instantiate(entry, inode); | |
501 | mutex_unlock(&fc->inst_mutex); | |
502 | } else | |
503 | d_instantiate(entry, inode); | |
504 | ||
505 | fuse_change_entry_timeout(entry, &outarg); | |
506 | fuse_invalidate_attr(dir); | |
507 | return 0; | |
508 | ||
509 | out_put_forget_req: | |
510 | fuse_put_request(fc, forget_req); | |
511 | return err; | |
512 | } | |
513 | ||
514 | static int fuse_mknod(struct inode *dir, struct dentry *entry, int mode, | |
515 | dev_t rdev) | |
516 | { | |
517 | struct fuse_mknod_in inarg; | |
518 | struct fuse_conn *fc = get_fuse_conn(dir); | |
519 | struct fuse_req *req = fuse_get_req(fc); | |
520 | if (IS_ERR(req)) | |
521 | return PTR_ERR(req); | |
522 | ||
523 | memset(&inarg, 0, sizeof(inarg)); | |
524 | inarg.mode = mode; | |
525 | inarg.rdev = new_encode_dev(rdev); | |
526 | req->in.h.opcode = FUSE_MKNOD; | |
527 | req->in.numargs = 2; | |
528 | req->in.args[0].size = sizeof(inarg); | |
529 | req->in.args[0].value = &inarg; | |
530 | req->in.args[1].size = entry->d_name.len + 1; | |
531 | req->in.args[1].value = entry->d_name.name; | |
532 | return create_new_entry(fc, req, dir, entry, mode); | |
533 | } | |
534 | ||
535 | static int fuse_create(struct inode *dir, struct dentry *entry, int mode, | |
536 | struct nameidata *nd) | |
537 | { | |
538 | if (nd && (nd->flags & LOOKUP_OPEN)) { | |
539 | int err = fuse_create_open(dir, entry, mode, nd); | |
540 | if (err != -ENOSYS) | |
541 | return err; | |
542 | /* Fall back on mknod */ | |
543 | } | |
544 | return fuse_mknod(dir, entry, mode, 0); | |
545 | } | |
546 | ||
547 | static int fuse_mkdir(struct inode *dir, struct dentry *entry, int mode) | |
548 | { | |
549 | struct fuse_mkdir_in inarg; | |
550 | struct fuse_conn *fc = get_fuse_conn(dir); | |
551 | struct fuse_req *req = fuse_get_req(fc); | |
552 | if (IS_ERR(req)) | |
553 | return PTR_ERR(req); | |
554 | ||
555 | memset(&inarg, 0, sizeof(inarg)); | |
556 | inarg.mode = mode; | |
557 | req->in.h.opcode = FUSE_MKDIR; | |
558 | req->in.numargs = 2; | |
559 | req->in.args[0].size = sizeof(inarg); | |
560 | req->in.args[0].value = &inarg; | |
561 | req->in.args[1].size = entry->d_name.len + 1; | |
562 | req->in.args[1].value = entry->d_name.name; | |
563 | return create_new_entry(fc, req, dir, entry, S_IFDIR); | |
564 | } | |
565 | ||
566 | static int fuse_symlink(struct inode *dir, struct dentry *entry, | |
567 | const char *link) | |
568 | { | |
569 | struct fuse_conn *fc = get_fuse_conn(dir); | |
570 | unsigned len = strlen(link) + 1; | |
571 | struct fuse_req *req = fuse_get_req(fc); | |
572 | if (IS_ERR(req)) | |
573 | return PTR_ERR(req); | |
574 | ||
575 | req->in.h.opcode = FUSE_SYMLINK; | |
576 | req->in.numargs = 2; | |
577 | req->in.args[0].size = entry->d_name.len + 1; | |
578 | req->in.args[0].value = entry->d_name.name; | |
579 | req->in.args[1].size = len; | |
580 | req->in.args[1].value = link; | |
581 | return create_new_entry(fc, req, dir, entry, S_IFLNK); | |
582 | } | |
583 | ||
584 | static int fuse_unlink(struct inode *dir, struct dentry *entry) | |
585 | { | |
586 | int err; | |
587 | struct fuse_conn *fc = get_fuse_conn(dir); | |
588 | struct fuse_req *req = fuse_get_req(fc); | |
589 | if (IS_ERR(req)) | |
590 | return PTR_ERR(req); | |
591 | ||
592 | req->in.h.opcode = FUSE_UNLINK; | |
593 | req->in.h.nodeid = get_node_id(dir); | |
594 | req->in.numargs = 1; | |
595 | req->in.args[0].size = entry->d_name.len + 1; | |
596 | req->in.args[0].value = entry->d_name.name; | |
597 | request_send(fc, req); | |
598 | err = req->out.h.error; | |
599 | fuse_put_request(fc, req); | |
600 | if (!err) { | |
601 | struct inode *inode = entry->d_inode; | |
602 | ||
603 | /* Set nlink to zero so the inode can be cleared, if | |
604 | the inode does have more links this will be | |
605 | discovered at the next lookup/getattr */ | |
606 | clear_nlink(inode); | |
607 | fuse_invalidate_attr(inode); | |
608 | fuse_invalidate_attr(dir); | |
609 | fuse_invalidate_entry_cache(entry); | |
610 | } else if (err == -EINTR) | |
611 | fuse_invalidate_entry(entry); | |
612 | return err; | |
613 | } | |
614 | ||
615 | static int fuse_rmdir(struct inode *dir, struct dentry *entry) | |
616 | { | |
617 | int err; | |
618 | struct fuse_conn *fc = get_fuse_conn(dir); | |
619 | struct fuse_req *req = fuse_get_req(fc); | |
620 | if (IS_ERR(req)) | |
621 | return PTR_ERR(req); | |
622 | ||
623 | req->in.h.opcode = FUSE_RMDIR; | |
624 | req->in.h.nodeid = get_node_id(dir); | |
625 | req->in.numargs = 1; | |
626 | req->in.args[0].size = entry->d_name.len + 1; | |
627 | req->in.args[0].value = entry->d_name.name; | |
628 | request_send(fc, req); | |
629 | err = req->out.h.error; | |
630 | fuse_put_request(fc, req); | |
631 | if (!err) { | |
632 | clear_nlink(entry->d_inode); | |
633 | fuse_invalidate_attr(dir); | |
634 | fuse_invalidate_entry_cache(entry); | |
635 | } else if (err == -EINTR) | |
636 | fuse_invalidate_entry(entry); | |
637 | return err; | |
638 | } | |
639 | ||
640 | static int fuse_rename(struct inode *olddir, struct dentry *oldent, | |
641 | struct inode *newdir, struct dentry *newent) | |
642 | { | |
643 | int err; | |
644 | struct fuse_rename_in inarg; | |
645 | struct fuse_conn *fc = get_fuse_conn(olddir); | |
646 | struct fuse_req *req = fuse_get_req(fc); | |
647 | if (IS_ERR(req)) | |
648 | return PTR_ERR(req); | |
649 | ||
650 | memset(&inarg, 0, sizeof(inarg)); | |
651 | inarg.newdir = get_node_id(newdir); | |
652 | req->in.h.opcode = FUSE_RENAME; | |
653 | req->in.h.nodeid = get_node_id(olddir); | |
654 | req->in.numargs = 3; | |
655 | req->in.args[0].size = sizeof(inarg); | |
656 | req->in.args[0].value = &inarg; | |
657 | req->in.args[1].size = oldent->d_name.len + 1; | |
658 | req->in.args[1].value = oldent->d_name.name; | |
659 | req->in.args[2].size = newent->d_name.len + 1; | |
660 | req->in.args[2].value = newent->d_name.name; | |
661 | request_send(fc, req); | |
662 | err = req->out.h.error; | |
663 | fuse_put_request(fc, req); | |
664 | if (!err) { | |
665 | /* ctime changes */ | |
666 | fuse_invalidate_attr(oldent->d_inode); | |
667 | ||
668 | fuse_invalidate_attr(olddir); | |
669 | if (olddir != newdir) | |
670 | fuse_invalidate_attr(newdir); | |
671 | ||
672 | /* newent will end up negative */ | |
673 | if (newent->d_inode) | |
674 | fuse_invalidate_entry_cache(newent); | |
675 | } else if (err == -EINTR) { | |
676 | /* If request was interrupted, DEITY only knows if the | |
677 | rename actually took place. If the invalidation | |
678 | fails (e.g. some process has CWD under the renamed | |
679 | directory), then there can be inconsistency between | |
680 | the dcache and the real filesystem. Tough luck. */ | |
681 | fuse_invalidate_entry(oldent); | |
682 | if (newent->d_inode) | |
683 | fuse_invalidate_entry(newent); | |
684 | } | |
685 | ||
686 | return err; | |
687 | } | |
688 | ||
689 | static int fuse_link(struct dentry *entry, struct inode *newdir, | |
690 | struct dentry *newent) | |
691 | { | |
692 | int err; | |
693 | struct fuse_link_in inarg; | |
694 | struct inode *inode = entry->d_inode; | |
695 | struct fuse_conn *fc = get_fuse_conn(inode); | |
696 | struct fuse_req *req = fuse_get_req(fc); | |
697 | if (IS_ERR(req)) | |
698 | return PTR_ERR(req); | |
699 | ||
700 | memset(&inarg, 0, sizeof(inarg)); | |
701 | inarg.oldnodeid = get_node_id(inode); | |
702 | req->in.h.opcode = FUSE_LINK; | |
703 | req->in.numargs = 2; | |
704 | req->in.args[0].size = sizeof(inarg); | |
705 | req->in.args[0].value = &inarg; | |
706 | req->in.args[1].size = newent->d_name.len + 1; | |
707 | req->in.args[1].value = newent->d_name.name; | |
708 | err = create_new_entry(fc, req, newdir, newent, inode->i_mode); | |
709 | /* Contrary to "normal" filesystems it can happen that link | |
710 | makes two "logical" inodes point to the same "physical" | |
711 | inode. We invalidate the attributes of the old one, so it | |
712 | will reflect changes in the backing inode (link count, | |
713 | etc.) | |
714 | */ | |
715 | if (!err || err == -EINTR) | |
716 | fuse_invalidate_attr(inode); | |
717 | return err; | |
718 | } | |
719 | ||
720 | static void fuse_fillattr(struct inode *inode, struct fuse_attr *attr, | |
721 | struct kstat *stat) | |
722 | { | |
723 | stat->dev = inode->i_sb->s_dev; | |
724 | stat->ino = attr->ino; | |
725 | stat->mode = (inode->i_mode & S_IFMT) | (attr->mode & 07777); | |
726 | stat->nlink = attr->nlink; | |
727 | stat->uid = attr->uid; | |
728 | stat->gid = attr->gid; | |
729 | stat->rdev = inode->i_rdev; | |
730 | stat->atime.tv_sec = attr->atime; | |
731 | stat->atime.tv_nsec = attr->atimensec; | |
732 | stat->mtime.tv_sec = attr->mtime; | |
733 | stat->mtime.tv_nsec = attr->mtimensec; | |
734 | stat->ctime.tv_sec = attr->ctime; | |
735 | stat->ctime.tv_nsec = attr->ctimensec; | |
736 | stat->size = attr->size; | |
737 | stat->blocks = attr->blocks; | |
738 | stat->blksize = (1 << inode->i_blkbits); | |
739 | } | |
740 | ||
741 | static int fuse_do_getattr(struct inode *inode, struct kstat *stat, | |
742 | struct file *file) | |
743 | { | |
744 | int err; | |
745 | struct fuse_getattr_in inarg; | |
746 | struct fuse_attr_out outarg; | |
747 | struct fuse_conn *fc = get_fuse_conn(inode); | |
748 | struct fuse_req *req; | |
749 | u64 attr_version; | |
750 | ||
751 | req = fuse_get_req(fc); | |
752 | if (IS_ERR(req)) | |
753 | return PTR_ERR(req); | |
754 | ||
755 | attr_version = fuse_get_attr_version(fc); | |
756 | ||
757 | memset(&inarg, 0, sizeof(inarg)); | |
758 | memset(&outarg, 0, sizeof(outarg)); | |
759 | /* Directories have separate file-handle space */ | |
760 | if (file && S_ISREG(inode->i_mode)) { | |
761 | struct fuse_file *ff = file->private_data; | |
762 | ||
763 | inarg.getattr_flags |= FUSE_GETATTR_FH; | |
764 | inarg.fh = ff->fh; | |
765 | } | |
766 | req->in.h.opcode = FUSE_GETATTR; | |
767 | req->in.h.nodeid = get_node_id(inode); | |
768 | req->in.numargs = 1; | |
769 | req->in.args[0].size = sizeof(inarg); | |
770 | req->in.args[0].value = &inarg; | |
771 | req->out.numargs = 1; | |
772 | if (fc->minor < 9) | |
773 | req->out.args[0].size = FUSE_COMPAT_ATTR_OUT_SIZE; | |
774 | else | |
775 | req->out.args[0].size = sizeof(outarg); | |
776 | req->out.args[0].value = &outarg; | |
777 | request_send(fc, req); | |
778 | err = req->out.h.error; | |
779 | fuse_put_request(fc, req); | |
780 | if (!err) { | |
781 | if ((inode->i_mode ^ outarg.attr.mode) & S_IFMT) { | |
782 | make_bad_inode(inode); | |
783 | err = -EIO; | |
784 | } else { | |
785 | fuse_change_attributes(inode, &outarg.attr, | |
786 | attr_timeout(&outarg), | |
787 | attr_version); | |
788 | if (stat) | |
789 | fuse_fillattr(inode, &outarg.attr, stat); | |
790 | } | |
791 | } | |
792 | return err; | |
793 | } | |
794 | ||
795 | int fuse_update_attributes(struct inode *inode, struct kstat *stat, | |
796 | struct file *file, bool *refreshed) | |
797 | { | |
798 | struct fuse_inode *fi = get_fuse_inode(inode); | |
799 | int err; | |
800 | bool r; | |
801 | ||
802 | if (fi->i_time < get_jiffies_64()) { | |
803 | r = true; | |
804 | err = fuse_do_getattr(inode, stat, file); | |
805 | } else { | |
806 | r = false; | |
807 | err = 0; | |
808 | if (stat) { | |
809 | generic_fillattr(inode, stat); | |
810 | stat->mode = fi->orig_i_mode; | |
811 | } | |
812 | } | |
813 | ||
814 | if (refreshed != NULL) | |
815 | *refreshed = r; | |
816 | ||
817 | return err; | |
818 | } | |
819 | ||
820 | /* | |
821 | * Calling into a user-controlled filesystem gives the filesystem | |
822 | * daemon ptrace-like capabilities over the requester process. This | |
823 | * means, that the filesystem daemon is able to record the exact | |
824 | * filesystem operations performed, and can also control the behavior | |
825 | * of the requester process in otherwise impossible ways. For example | |
826 | * it can delay the operation for arbitrary length of time allowing | |
827 | * DoS against the requester. | |
828 | * | |
829 | * For this reason only those processes can call into the filesystem, | |
830 | * for which the owner of the mount has ptrace privilege. This | |
831 | * excludes processes started by other users, suid or sgid processes. | |
832 | */ | |
833 | int fuse_allow_task(struct fuse_conn *fc, struct task_struct *task) | |
834 | { | |
835 | if (fc->flags & FUSE_ALLOW_OTHER) | |
836 | return 1; | |
837 | ||
838 | if (task->euid == fc->user_id && | |
839 | task->suid == fc->user_id && | |
840 | task->uid == fc->user_id && | |
841 | task->egid == fc->group_id && | |
842 | task->sgid == fc->group_id && | |
843 | task->gid == fc->group_id) | |
844 | return 1; | |
845 | ||
846 | return 0; | |
847 | } | |
848 | ||
849 | static int fuse_access(struct inode *inode, int mask) | |
850 | { | |
851 | struct fuse_conn *fc = get_fuse_conn(inode); | |
852 | struct fuse_req *req; | |
853 | struct fuse_access_in inarg; | |
854 | int err; | |
855 | ||
856 | if (fc->no_access) | |
857 | return 0; | |
858 | ||
859 | req = fuse_get_req(fc); | |
860 | if (IS_ERR(req)) | |
861 | return PTR_ERR(req); | |
862 | ||
863 | memset(&inarg, 0, sizeof(inarg)); | |
864 | inarg.mask = mask; | |
865 | req->in.h.opcode = FUSE_ACCESS; | |
866 | req->in.h.nodeid = get_node_id(inode); | |
867 | req->in.numargs = 1; | |
868 | req->in.args[0].size = sizeof(inarg); | |
869 | req->in.args[0].value = &inarg; | |
870 | request_send(fc, req); | |
871 | err = req->out.h.error; | |
872 | fuse_put_request(fc, req); | |
873 | if (err == -ENOSYS) { | |
874 | fc->no_access = 1; | |
875 | err = 0; | |
876 | } | |
877 | return err; | |
878 | } | |
879 | ||
880 | /* | |
881 | * Check permission. The two basic access models of FUSE are: | |
882 | * | |
883 | * 1) Local access checking ('default_permissions' mount option) based | |
884 | * on file mode. This is the plain old disk filesystem permission | |
885 | * modell. | |
886 | * | |
887 | * 2) "Remote" access checking, where server is responsible for | |
888 | * checking permission in each inode operation. An exception to this | |
889 | * is if ->permission() was invoked from sys_access() in which case an | |
890 | * access request is sent. Execute permission is still checked | |
891 | * locally based on file mode. | |
892 | */ | |
893 | static int fuse_permission(struct inode *inode, int mask, struct nameidata *nd) | |
894 | { | |
895 | struct fuse_conn *fc = get_fuse_conn(inode); | |
896 | bool refreshed = false; | |
897 | int err = 0; | |
898 | ||
899 | if (!fuse_allow_task(fc, current)) | |
900 | return -EACCES; | |
901 | ||
902 | /* | |
903 | * If attributes are needed, refresh them before proceeding | |
904 | */ | |
905 | if ((fc->flags & FUSE_DEFAULT_PERMISSIONS) || | |
906 | ((mask & MAY_EXEC) && S_ISREG(inode->i_mode))) { | |
907 | err = fuse_update_attributes(inode, NULL, NULL, &refreshed); | |
908 | if (err) | |
909 | return err; | |
910 | } | |
911 | ||
912 | if (fc->flags & FUSE_DEFAULT_PERMISSIONS) { | |
913 | err = generic_permission(inode, mask, NULL); | |
914 | ||
915 | /* If permission is denied, try to refresh file | |
916 | attributes. This is also needed, because the root | |
917 | node will at first have no permissions */ | |
918 | if (err == -EACCES && !refreshed) { | |
919 | err = fuse_do_getattr(inode, NULL, NULL); | |
920 | if (!err) | |
921 | err = generic_permission(inode, mask, NULL); | |
922 | } | |
923 | ||
924 | /* Note: the opposite of the above test does not | |
925 | exist. So if permissions are revoked this won't be | |
926 | noticed immediately, only after the attribute | |
927 | timeout has expired */ | |
928 | } else if (nd && (nd->flags & (LOOKUP_ACCESS | LOOKUP_CHDIR))) { | |
929 | err = fuse_access(inode, mask); | |
930 | } else if ((mask & MAY_EXEC) && S_ISREG(inode->i_mode)) { | |
931 | if (!(inode->i_mode & S_IXUGO)) { | |
932 | if (refreshed) | |
933 | return -EACCES; | |
934 | ||
935 | err = fuse_do_getattr(inode, NULL, NULL); | |
936 | if (!err && !(inode->i_mode & S_IXUGO)) | |
937 | return -EACCES; | |
938 | } | |
939 | } | |
940 | return err; | |
941 | } | |
942 | ||
943 | static int parse_dirfile(char *buf, size_t nbytes, struct file *file, | |
944 | void *dstbuf, filldir_t filldir) | |
945 | { | |
946 | while (nbytes >= FUSE_NAME_OFFSET) { | |
947 | struct fuse_dirent *dirent = (struct fuse_dirent *) buf; | |
948 | size_t reclen = FUSE_DIRENT_SIZE(dirent); | |
949 | int over; | |
950 | if (!dirent->namelen || dirent->namelen > FUSE_NAME_MAX) | |
951 | return -EIO; | |
952 | if (reclen > nbytes) | |
953 | break; | |
954 | ||
955 | over = filldir(dstbuf, dirent->name, dirent->namelen, | |
956 | file->f_pos, dirent->ino, dirent->type); | |
957 | if (over) | |
958 | break; | |
959 | ||
960 | buf += reclen; | |
961 | nbytes -= reclen; | |
962 | file->f_pos = dirent->off; | |
963 | } | |
964 | ||
965 | return 0; | |
966 | } | |
967 | ||
968 | static int fuse_readdir(struct file *file, void *dstbuf, filldir_t filldir) | |
969 | { | |
970 | int err; | |
971 | size_t nbytes; | |
972 | struct page *page; | |
973 | struct inode *inode = file->f_path.dentry->d_inode; | |
974 | struct fuse_conn *fc = get_fuse_conn(inode); | |
975 | struct fuse_req *req; | |
976 | ||
977 | if (is_bad_inode(inode)) | |
978 | return -EIO; | |
979 | ||
980 | req = fuse_get_req(fc); | |
981 | if (IS_ERR(req)) | |
982 | return PTR_ERR(req); | |
983 | ||
984 | page = alloc_page(GFP_KERNEL); | |
985 | if (!page) { | |
986 | fuse_put_request(fc, req); | |
987 | return -ENOMEM; | |
988 | } | |
989 | req->num_pages = 1; | |
990 | req->pages[0] = page; | |
991 | fuse_read_fill(req, file, inode, file->f_pos, PAGE_SIZE, FUSE_READDIR); | |
992 | request_send(fc, req); | |
993 | nbytes = req->out.args[0].size; | |
994 | err = req->out.h.error; | |
995 | fuse_put_request(fc, req); | |
996 | if (!err) | |
997 | err = parse_dirfile(page_address(page), nbytes, file, dstbuf, | |
998 | filldir); | |
999 | ||
1000 | __free_page(page); | |
1001 | fuse_invalidate_attr(inode); /* atime changed */ | |
1002 | return err; | |
1003 | } | |
1004 | ||
1005 | static char *read_link(struct dentry *dentry) | |
1006 | { | |
1007 | struct inode *inode = dentry->d_inode; | |
1008 | struct fuse_conn *fc = get_fuse_conn(inode); | |
1009 | struct fuse_req *req = fuse_get_req(fc); | |
1010 | char *link; | |
1011 | ||
1012 | if (IS_ERR(req)) | |
1013 | return ERR_CAST(req); | |
1014 | ||
1015 | link = (char *) __get_free_page(GFP_KERNEL); | |
1016 | if (!link) { | |
1017 | link = ERR_PTR(-ENOMEM); | |
1018 | goto out; | |
1019 | } | |
1020 | req->in.h.opcode = FUSE_READLINK; | |
1021 | req->in.h.nodeid = get_node_id(inode); | |
1022 | req->out.argvar = 1; | |
1023 | req->out.numargs = 1; | |
1024 | req->out.args[0].size = PAGE_SIZE - 1; | |
1025 | req->out.args[0].value = link; | |
1026 | request_send(fc, req); | |
1027 | if (req->out.h.error) { | |
1028 | free_page((unsigned long) link); | |
1029 | link = ERR_PTR(req->out.h.error); | |
1030 | } else | |
1031 | link[req->out.args[0].size] = '\0'; | |
1032 | out: | |
1033 | fuse_put_request(fc, req); | |
1034 | fuse_invalidate_attr(inode); /* atime changed */ | |
1035 | return link; | |
1036 | } | |
1037 | ||
1038 | static void free_link(char *link) | |
1039 | { | |
1040 | if (!IS_ERR(link)) | |
1041 | free_page((unsigned long) link); | |
1042 | } | |
1043 | ||
1044 | static void *fuse_follow_link(struct dentry *dentry, struct nameidata *nd) | |
1045 | { | |
1046 | nd_set_link(nd, read_link(dentry)); | |
1047 | return NULL; | |
1048 | } | |
1049 | ||
1050 | static void fuse_put_link(struct dentry *dentry, struct nameidata *nd, void *c) | |
1051 | { | |
1052 | free_link(nd_get_link(nd)); | |
1053 | } | |
1054 | ||
1055 | static int fuse_dir_open(struct inode *inode, struct file *file) | |
1056 | { | |
1057 | return fuse_open_common(inode, file, 1); | |
1058 | } | |
1059 | ||
1060 | static int fuse_dir_release(struct inode *inode, struct file *file) | |
1061 | { | |
1062 | return fuse_release_common(inode, file, 1); | |
1063 | } | |
1064 | ||
1065 | static int fuse_dir_fsync(struct file *file, struct dentry *de, int datasync) | |
1066 | { | |
1067 | /* nfsd can call this with no file */ | |
1068 | return file ? fuse_fsync_common(file, de, datasync, 1) : 0; | |
1069 | } | |
1070 | ||
1071 | static bool update_mtime(unsigned ivalid) | |
1072 | { | |
1073 | /* Always update if mtime is explicitly set */ | |
1074 | if (ivalid & ATTR_MTIME_SET) | |
1075 | return true; | |
1076 | ||
1077 | /* If it's an open(O_TRUNC) or an ftruncate(), don't update */ | |
1078 | if ((ivalid & ATTR_SIZE) && (ivalid & (ATTR_OPEN | ATTR_FILE))) | |
1079 | return false; | |
1080 | ||
1081 | /* In all other cases update */ | |
1082 | return true; | |
1083 | } | |
1084 | ||
1085 | static void iattr_to_fattr(struct iattr *iattr, struct fuse_setattr_in *arg) | |
1086 | { | |
1087 | unsigned ivalid = iattr->ia_valid; | |
1088 | ||
1089 | if (ivalid & ATTR_MODE) | |
1090 | arg->valid |= FATTR_MODE, arg->mode = iattr->ia_mode; | |
1091 | if (ivalid & ATTR_UID) | |
1092 | arg->valid |= FATTR_UID, arg->uid = iattr->ia_uid; | |
1093 | if (ivalid & ATTR_GID) | |
1094 | arg->valid |= FATTR_GID, arg->gid = iattr->ia_gid; | |
1095 | if (ivalid & ATTR_SIZE) | |
1096 | arg->valid |= FATTR_SIZE, arg->size = iattr->ia_size; | |
1097 | if (ivalid & ATTR_ATIME) { | |
1098 | arg->valid |= FATTR_ATIME; | |
1099 | arg->atime = iattr->ia_atime.tv_sec; | |
1100 | arg->atimensec = iattr->ia_atime.tv_nsec; | |
1101 | if (!(ivalid & ATTR_ATIME_SET)) | |
1102 | arg->valid |= FATTR_ATIME_NOW; | |
1103 | } | |
1104 | if ((ivalid & ATTR_MTIME) && update_mtime(ivalid)) { | |
1105 | arg->valid |= FATTR_MTIME; | |
1106 | arg->mtime = iattr->ia_mtime.tv_sec; | |
1107 | arg->mtimensec = iattr->ia_mtime.tv_nsec; | |
1108 | if (!(ivalid & ATTR_MTIME_SET)) | |
1109 | arg->valid |= FATTR_MTIME_NOW; | |
1110 | } | |
1111 | } | |
1112 | ||
1113 | /* | |
1114 | * Prevent concurrent writepages on inode | |
1115 | * | |
1116 | * This is done by adding a negative bias to the inode write counter | |
1117 | * and waiting for all pending writes to finish. | |
1118 | */ | |
1119 | void fuse_set_nowrite(struct inode *inode) | |
1120 | { | |
1121 | struct fuse_conn *fc = get_fuse_conn(inode); | |
1122 | struct fuse_inode *fi = get_fuse_inode(inode); | |
1123 | ||
1124 | BUG_ON(!mutex_is_locked(&inode->i_mutex)); | |
1125 | ||
1126 | spin_lock(&fc->lock); | |
1127 | BUG_ON(fi->writectr < 0); | |
1128 | fi->writectr += FUSE_NOWRITE; | |
1129 | spin_unlock(&fc->lock); | |
1130 | wait_event(fi->page_waitq, fi->writectr == FUSE_NOWRITE); | |
1131 | } | |
1132 | ||
1133 | /* | |
1134 | * Allow writepages on inode | |
1135 | * | |
1136 | * Remove the bias from the writecounter and send any queued | |
1137 | * writepages. | |
1138 | */ | |
1139 | static void __fuse_release_nowrite(struct inode *inode) | |
1140 | { | |
1141 | struct fuse_inode *fi = get_fuse_inode(inode); | |
1142 | ||
1143 | BUG_ON(fi->writectr != FUSE_NOWRITE); | |
1144 | fi->writectr = 0; | |
1145 | fuse_flush_writepages(inode); | |
1146 | } | |
1147 | ||
1148 | void fuse_release_nowrite(struct inode *inode) | |
1149 | { | |
1150 | struct fuse_conn *fc = get_fuse_conn(inode); | |
1151 | ||
1152 | spin_lock(&fc->lock); | |
1153 | __fuse_release_nowrite(inode); | |
1154 | spin_unlock(&fc->lock); | |
1155 | } | |
1156 | ||
1157 | /* | |
1158 | * Set attributes, and at the same time refresh them. | |
1159 | * | |
1160 | * Truncation is slightly complicated, because the 'truncate' request | |
1161 | * may fail, in which case we don't want to touch the mapping. | |
1162 | * vmtruncate() doesn't allow for this case, so do the rlimit checking | |
1163 | * and the actual truncation by hand. | |
1164 | */ | |
1165 | static int fuse_do_setattr(struct dentry *entry, struct iattr *attr, | |
1166 | struct file *file) | |
1167 | { | |
1168 | struct inode *inode = entry->d_inode; | |
1169 | struct fuse_conn *fc = get_fuse_conn(inode); | |
1170 | struct fuse_req *req; | |
1171 | struct fuse_setattr_in inarg; | |
1172 | struct fuse_attr_out outarg; | |
1173 | bool is_truncate = false; | |
1174 | loff_t oldsize; | |
1175 | int err; | |
1176 | ||
1177 | if (!fuse_allow_task(fc, current)) | |
1178 | return -EACCES; | |
1179 | ||
1180 | if (fc->flags & FUSE_DEFAULT_PERMISSIONS) { | |
1181 | err = inode_change_ok(inode, attr); | |
1182 | if (err) | |
1183 | return err; | |
1184 | } | |
1185 | ||
1186 | if ((attr->ia_valid & ATTR_OPEN) && fc->atomic_o_trunc) | |
1187 | return 0; | |
1188 | ||
1189 | if (attr->ia_valid & ATTR_SIZE) { | |
1190 | unsigned long limit; | |
1191 | if (IS_SWAPFILE(inode)) | |
1192 | return -ETXTBSY; | |
1193 | limit = current->signal->rlim[RLIMIT_FSIZE].rlim_cur; | |
1194 | if (limit != RLIM_INFINITY && attr->ia_size > (loff_t) limit) { | |
1195 | send_sig(SIGXFSZ, current, 0); | |
1196 | return -EFBIG; | |
1197 | } | |
1198 | is_truncate = true; | |
1199 | } | |
1200 | ||
1201 | req = fuse_get_req(fc); | |
1202 | if (IS_ERR(req)) | |
1203 | return PTR_ERR(req); | |
1204 | ||
1205 | if (is_truncate) | |
1206 | fuse_set_nowrite(inode); | |
1207 | ||
1208 | memset(&inarg, 0, sizeof(inarg)); | |
1209 | memset(&outarg, 0, sizeof(outarg)); | |
1210 | iattr_to_fattr(attr, &inarg); | |
1211 | if (file) { | |
1212 | struct fuse_file *ff = file->private_data; | |
1213 | inarg.valid |= FATTR_FH; | |
1214 | inarg.fh = ff->fh; | |
1215 | } | |
1216 | if (attr->ia_valid & ATTR_SIZE) { | |
1217 | /* For mandatory locking in truncate */ | |
1218 | inarg.valid |= FATTR_LOCKOWNER; | |
1219 | inarg.lock_owner = fuse_lock_owner_id(fc, current->files); | |
1220 | } | |
1221 | req->in.h.opcode = FUSE_SETATTR; | |
1222 | req->in.h.nodeid = get_node_id(inode); | |
1223 | req->in.numargs = 1; | |
1224 | req->in.args[0].size = sizeof(inarg); | |
1225 | req->in.args[0].value = &inarg; | |
1226 | req->out.numargs = 1; | |
1227 | if (fc->minor < 9) | |
1228 | req->out.args[0].size = FUSE_COMPAT_ATTR_OUT_SIZE; | |
1229 | else | |
1230 | req->out.args[0].size = sizeof(outarg); | |
1231 | req->out.args[0].value = &outarg; | |
1232 | request_send(fc, req); | |
1233 | err = req->out.h.error; | |
1234 | fuse_put_request(fc, req); | |
1235 | if (err) { | |
1236 | if (err == -EINTR) | |
1237 | fuse_invalidate_attr(inode); | |
1238 | goto error; | |
1239 | } | |
1240 | ||
1241 | if ((inode->i_mode ^ outarg.attr.mode) & S_IFMT) { | |
1242 | make_bad_inode(inode); | |
1243 | err = -EIO; | |
1244 | goto error; | |
1245 | } | |
1246 | ||
1247 | spin_lock(&fc->lock); | |
1248 | fuse_change_attributes_common(inode, &outarg.attr, | |
1249 | attr_timeout(&outarg)); | |
1250 | oldsize = inode->i_size; | |
1251 | i_size_write(inode, outarg.attr.size); | |
1252 | ||
1253 | if (is_truncate) { | |
1254 | /* NOTE: this may release/reacquire fc->lock */ | |
1255 | __fuse_release_nowrite(inode); | |
1256 | } | |
1257 | spin_unlock(&fc->lock); | |
1258 | ||
1259 | /* | |
1260 | * Only call invalidate_inode_pages2() after removing | |
1261 | * FUSE_NOWRITE, otherwise fuse_launder_page() would deadlock. | |
1262 | */ | |
1263 | if (S_ISREG(inode->i_mode) && oldsize != outarg.attr.size) { | |
1264 | if (outarg.attr.size < oldsize) | |
1265 | fuse_truncate(inode->i_mapping, outarg.attr.size); | |
1266 | invalidate_inode_pages2(inode->i_mapping); | |
1267 | } | |
1268 | ||
1269 | return 0; | |
1270 | ||
1271 | error: | |
1272 | if (is_truncate) | |
1273 | fuse_release_nowrite(inode); | |
1274 | ||
1275 | return err; | |
1276 | } | |
1277 | ||
1278 | static int fuse_setattr(struct dentry *entry, struct iattr *attr) | |
1279 | { | |
1280 | if (attr->ia_valid & ATTR_FILE) | |
1281 | return fuse_do_setattr(entry, attr, attr->ia_file); | |
1282 | else | |
1283 | return fuse_do_setattr(entry, attr, NULL); | |
1284 | } | |
1285 | ||
1286 | static int fuse_getattr(struct vfsmount *mnt, struct dentry *entry, | |
1287 | struct kstat *stat) | |
1288 | { | |
1289 | struct inode *inode = entry->d_inode; | |
1290 | struct fuse_conn *fc = get_fuse_conn(inode); | |
1291 | ||
1292 | if (!fuse_allow_task(fc, current)) | |
1293 | return -EACCES; | |
1294 | ||
1295 | return fuse_update_attributes(inode, stat, NULL, NULL); | |
1296 | } | |
1297 | ||
1298 | static int fuse_setxattr(struct dentry *entry, const char *name, | |
1299 | const void *value, size_t size, int flags) | |
1300 | { | |
1301 | struct inode *inode = entry->d_inode; | |
1302 | struct fuse_conn *fc = get_fuse_conn(inode); | |
1303 | struct fuse_req *req; | |
1304 | struct fuse_setxattr_in inarg; | |
1305 | int err; | |
1306 | ||
1307 | if (fc->no_setxattr) | |
1308 | return -EOPNOTSUPP; | |
1309 | ||
1310 | req = fuse_get_req(fc); | |
1311 | if (IS_ERR(req)) | |
1312 | return PTR_ERR(req); | |
1313 | ||
1314 | memset(&inarg, 0, sizeof(inarg)); | |
1315 | inarg.size = size; | |
1316 | inarg.flags = flags; | |
1317 | req->in.h.opcode = FUSE_SETXATTR; | |
1318 | req->in.h.nodeid = get_node_id(inode); | |
1319 | req->in.numargs = 3; | |
1320 | req->in.args[0].size = sizeof(inarg); | |
1321 | req->in.args[0].value = &inarg; | |
1322 | req->in.args[1].size = strlen(name) + 1; | |
1323 | req->in.args[1].value = name; | |
1324 | req->in.args[2].size = size; | |
1325 | req->in.args[2].value = value; | |
1326 | request_send(fc, req); | |
1327 | err = req->out.h.error; | |
1328 | fuse_put_request(fc, req); | |
1329 | if (err == -ENOSYS) { | |
1330 | fc->no_setxattr = 1; | |
1331 | err = -EOPNOTSUPP; | |
1332 | } | |
1333 | return err; | |
1334 | } | |
1335 | ||
1336 | static ssize_t fuse_getxattr(struct dentry *entry, const char *name, | |
1337 | void *value, size_t size) | |
1338 | { | |
1339 | struct inode *inode = entry->d_inode; | |
1340 | struct fuse_conn *fc = get_fuse_conn(inode); | |
1341 | struct fuse_req *req; | |
1342 | struct fuse_getxattr_in inarg; | |
1343 | struct fuse_getxattr_out outarg; | |
1344 | ssize_t ret; | |
1345 | ||
1346 | if (fc->no_getxattr) | |
1347 | return -EOPNOTSUPP; | |
1348 | ||
1349 | req = fuse_get_req(fc); | |
1350 | if (IS_ERR(req)) | |
1351 | return PTR_ERR(req); | |
1352 | ||
1353 | memset(&inarg, 0, sizeof(inarg)); | |
1354 | inarg.size = size; | |
1355 | req->in.h.opcode = FUSE_GETXATTR; | |
1356 | req->in.h.nodeid = get_node_id(inode); | |
1357 | req->in.numargs = 2; | |
1358 | req->in.args[0].size = sizeof(inarg); | |
1359 | req->in.args[0].value = &inarg; | |
1360 | req->in.args[1].size = strlen(name) + 1; | |
1361 | req->in.args[1].value = name; | |
1362 | /* This is really two different operations rolled into one */ | |
1363 | req->out.numargs = 1; | |
1364 | if (size) { | |
1365 | req->out.argvar = 1; | |
1366 | req->out.args[0].size = size; | |
1367 | req->out.args[0].value = value; | |
1368 | } else { | |
1369 | req->out.args[0].size = sizeof(outarg); | |
1370 | req->out.args[0].value = &outarg; | |
1371 | } | |
1372 | request_send(fc, req); | |
1373 | ret = req->out.h.error; | |
1374 | if (!ret) | |
1375 | ret = size ? req->out.args[0].size : outarg.size; | |
1376 | else { | |
1377 | if (ret == -ENOSYS) { | |
1378 | fc->no_getxattr = 1; | |
1379 | ret = -EOPNOTSUPP; | |
1380 | } | |
1381 | } | |
1382 | fuse_put_request(fc, req); | |
1383 | return ret; | |
1384 | } | |
1385 | ||
1386 | static ssize_t fuse_listxattr(struct dentry *entry, char *list, size_t size) | |
1387 | { | |
1388 | struct inode *inode = entry->d_inode; | |
1389 | struct fuse_conn *fc = get_fuse_conn(inode); | |
1390 | struct fuse_req *req; | |
1391 | struct fuse_getxattr_in inarg; | |
1392 | struct fuse_getxattr_out outarg; | |
1393 | ssize_t ret; | |
1394 | ||
1395 | if (!fuse_allow_task(fc, current)) | |
1396 | return -EACCES; | |
1397 | ||
1398 | if (fc->no_listxattr) | |
1399 | return -EOPNOTSUPP; | |
1400 | ||
1401 | req = fuse_get_req(fc); | |
1402 | if (IS_ERR(req)) | |
1403 | return PTR_ERR(req); | |
1404 | ||
1405 | memset(&inarg, 0, sizeof(inarg)); | |
1406 | inarg.size = size; | |
1407 | req->in.h.opcode = FUSE_LISTXATTR; | |
1408 | req->in.h.nodeid = get_node_id(inode); | |
1409 | req->in.numargs = 1; | |
1410 | req->in.args[0].size = sizeof(inarg); | |
1411 | req->in.args[0].value = &inarg; | |
1412 | /* This is really two different operations rolled into one */ | |
1413 | req->out.numargs = 1; | |
1414 | if (size) { | |
1415 | req->out.argvar = 1; | |
1416 | req->out.args[0].size = size; | |
1417 | req->out.args[0].value = list; | |
1418 | } else { | |
1419 | req->out.args[0].size = sizeof(outarg); | |
1420 | req->out.args[0].value = &outarg; | |
1421 | } | |
1422 | request_send(fc, req); | |
1423 | ret = req->out.h.error; | |
1424 | if (!ret) | |
1425 | ret = size ? req->out.args[0].size : outarg.size; | |
1426 | else { | |
1427 | if (ret == -ENOSYS) { | |
1428 | fc->no_listxattr = 1; | |
1429 | ret = -EOPNOTSUPP; | |
1430 | } | |
1431 | } | |
1432 | fuse_put_request(fc, req); | |
1433 | return ret; | |
1434 | } | |
1435 | ||
1436 | static int fuse_removexattr(struct dentry *entry, const char *name) | |
1437 | { | |
1438 | struct inode *inode = entry->d_inode; | |
1439 | struct fuse_conn *fc = get_fuse_conn(inode); | |
1440 | struct fuse_req *req; | |
1441 | int err; | |
1442 | ||
1443 | if (fc->no_removexattr) | |
1444 | return -EOPNOTSUPP; | |
1445 | ||
1446 | req = fuse_get_req(fc); | |
1447 | if (IS_ERR(req)) | |
1448 | return PTR_ERR(req); | |
1449 | ||
1450 | req->in.h.opcode = FUSE_REMOVEXATTR; | |
1451 | req->in.h.nodeid = get_node_id(inode); | |
1452 | req->in.numargs = 1; | |
1453 | req->in.args[0].size = strlen(name) + 1; | |
1454 | req->in.args[0].value = name; | |
1455 | request_send(fc, req); | |
1456 | err = req->out.h.error; | |
1457 | fuse_put_request(fc, req); | |
1458 | if (err == -ENOSYS) { | |
1459 | fc->no_removexattr = 1; | |
1460 | err = -EOPNOTSUPP; | |
1461 | } | |
1462 | return err; | |
1463 | } | |
1464 | ||
1465 | static const struct inode_operations fuse_dir_inode_operations = { | |
1466 | .lookup = fuse_lookup, | |
1467 | .mkdir = fuse_mkdir, | |
1468 | .symlink = fuse_symlink, | |
1469 | .unlink = fuse_unlink, | |
1470 | .rmdir = fuse_rmdir, | |
1471 | .rename = fuse_rename, | |
1472 | .link = fuse_link, | |
1473 | .setattr = fuse_setattr, | |
1474 | .create = fuse_create, | |
1475 | .mknod = fuse_mknod, | |
1476 | .permission = fuse_permission, | |
1477 | .getattr = fuse_getattr, | |
1478 | .setxattr = fuse_setxattr, | |
1479 | .getxattr = fuse_getxattr, | |
1480 | .listxattr = fuse_listxattr, | |
1481 | .removexattr = fuse_removexattr, | |
1482 | }; | |
1483 | ||
1484 | static const struct file_operations fuse_dir_operations = { | |
1485 | .llseek = generic_file_llseek, | |
1486 | .read = generic_read_dir, | |
1487 | .readdir = fuse_readdir, | |
1488 | .open = fuse_dir_open, | |
1489 | .release = fuse_dir_release, | |
1490 | .fsync = fuse_dir_fsync, | |
1491 | }; | |
1492 | ||
1493 | static const struct inode_operations fuse_common_inode_operations = { | |
1494 | .setattr = fuse_setattr, | |
1495 | .permission = fuse_permission, | |
1496 | .getattr = fuse_getattr, | |
1497 | .setxattr = fuse_setxattr, | |
1498 | .getxattr = fuse_getxattr, | |
1499 | .listxattr = fuse_listxattr, | |
1500 | .removexattr = fuse_removexattr, | |
1501 | }; | |
1502 | ||
1503 | static const struct inode_operations fuse_symlink_inode_operations = { | |
1504 | .setattr = fuse_setattr, | |
1505 | .follow_link = fuse_follow_link, | |
1506 | .put_link = fuse_put_link, | |
1507 | .readlink = generic_readlink, | |
1508 | .getattr = fuse_getattr, | |
1509 | .setxattr = fuse_setxattr, | |
1510 | .getxattr = fuse_getxattr, | |
1511 | .listxattr = fuse_listxattr, | |
1512 | .removexattr = fuse_removexattr, | |
1513 | }; | |
1514 | ||
1515 | void fuse_init_common(struct inode *inode) | |
1516 | { | |
1517 | inode->i_op = &fuse_common_inode_operations; | |
1518 | } | |
1519 | ||
1520 | void fuse_init_dir(struct inode *inode) | |
1521 | { | |
1522 | inode->i_op = &fuse_dir_inode_operations; | |
1523 | inode->i_fop = &fuse_dir_operations; | |
1524 | } | |
1525 | ||
1526 | void fuse_init_symlink(struct inode *inode) | |
1527 | { | |
1528 | inode->i_op = &fuse_symlink_inode_operations; | |
1529 | } |