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vfs: push dentry_unhash on rmdir into file systems
[deliverable/linux.git] / fs / fuse / dir.c
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
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 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_conn *fc, struct fuse_req *req,
116 u64 nodeid, struct qstr *name,
117 struct fuse_entry_out *outarg)
118 {
119 memset(outarg, 0, sizeof(struct fuse_entry_out));
120 req->in.h.opcode = FUSE_LOOKUP;
121 req->in.h.nodeid = nodeid;
122 req->in.numargs = 1;
123 req->in.args[0].size = name->len + 1;
124 req->in.args[0].value = name->name;
125 req->out.numargs = 1;
126 if (fc->minor < 9)
127 req->out.args[0].size = FUSE_COMPAT_ENTRY_OUT_SIZE;
128 else
129 req->out.args[0].size = sizeof(struct fuse_entry_out);
130 req->out.args[0].value = outarg;
131 }
132
133 u64 fuse_get_attr_version(struct fuse_conn *fc)
134 {
135 u64 curr_version;
136
137 /*
138 * The spin lock isn't actually needed on 64bit archs, but we
139 * don't yet care too much about such optimizations.
140 */
141 spin_lock(&fc->lock);
142 curr_version = fc->attr_version;
143 spin_unlock(&fc->lock);
144
145 return curr_version;
146 }
147
148 /*
149 * Check whether the dentry is still valid
150 *
151 * If the entry validity timeout has expired and the dentry is
152 * positive, try to redo the lookup. If the lookup results in a
153 * different inode, then let the VFS invalidate the dentry and redo
154 * the lookup once more. If the lookup results in the same inode,
155 * then refresh the attributes, timeouts and mark the dentry valid.
156 */
157 static int fuse_dentry_revalidate(struct dentry *entry, struct nameidata *nd)
158 {
159 struct inode *inode;
160
161 inode = ACCESS_ONCE(entry->d_inode);
162 if (inode && is_bad_inode(inode))
163 return 0;
164 else if (fuse_dentry_time(entry) < get_jiffies_64()) {
165 int err;
166 struct fuse_entry_out outarg;
167 struct fuse_conn *fc;
168 struct fuse_req *req;
169 struct fuse_forget_link *forget;
170 struct dentry *parent;
171 u64 attr_version;
172
173 /* For negative dentries, always do a fresh lookup */
174 if (!inode)
175 return 0;
176
177 if (nd->flags & LOOKUP_RCU)
178 return -ECHILD;
179
180 fc = get_fuse_conn(inode);
181 req = fuse_get_req(fc);
182 if (IS_ERR(req))
183 return 0;
184
185 forget = fuse_alloc_forget();
186 if (!forget) {
187 fuse_put_request(fc, req);
188 return 0;
189 }
190
191 attr_version = fuse_get_attr_version(fc);
192
193 parent = dget_parent(entry);
194 fuse_lookup_init(fc, req, get_node_id(parent->d_inode),
195 &entry->d_name, &outarg);
196 fuse_request_send(fc, req);
197 dput(parent);
198 err = req->out.h.error;
199 fuse_put_request(fc, req);
200 /* Zero nodeid is same as -ENOENT */
201 if (!err && !outarg.nodeid)
202 err = -ENOENT;
203 if (!err) {
204 struct fuse_inode *fi = get_fuse_inode(inode);
205 if (outarg.nodeid != get_node_id(inode)) {
206 fuse_queue_forget(fc, forget, outarg.nodeid, 1);
207 return 0;
208 }
209 spin_lock(&fc->lock);
210 fi->nlookup++;
211 spin_unlock(&fc->lock);
212 }
213 kfree(forget);
214 if (err || (outarg.attr.mode ^ inode->i_mode) & S_IFMT)
215 return 0;
216
217 fuse_change_attributes(inode, &outarg.attr,
218 entry_attr_timeout(&outarg),
219 attr_version);
220 fuse_change_entry_timeout(entry, &outarg);
221 }
222 return 1;
223 }
224
225 static int invalid_nodeid(u64 nodeid)
226 {
227 return !nodeid || nodeid == FUSE_ROOT_ID;
228 }
229
230 const struct dentry_operations fuse_dentry_operations = {
231 .d_revalidate = fuse_dentry_revalidate,
232 };
233
234 int fuse_valid_type(int m)
235 {
236 return S_ISREG(m) || S_ISDIR(m) || S_ISLNK(m) || S_ISCHR(m) ||
237 S_ISBLK(m) || S_ISFIFO(m) || S_ISSOCK(m);
238 }
239
240 /*
241 * Add a directory inode to a dentry, ensuring that no other dentry
242 * refers to this inode. Called with fc->inst_mutex.
243 */
244 static struct dentry *fuse_d_add_directory(struct dentry *entry,
245 struct inode *inode)
246 {
247 struct dentry *alias = d_find_alias(inode);
248 if (alias && !(alias->d_flags & DCACHE_DISCONNECTED)) {
249 /* This tries to shrink the subtree below alias */
250 fuse_invalidate_entry(alias);
251 dput(alias);
252 if (!list_empty(&inode->i_dentry))
253 return ERR_PTR(-EBUSY);
254 } else {
255 dput(alias);
256 }
257 return d_splice_alias(inode, entry);
258 }
259
260 int fuse_lookup_name(struct super_block *sb, u64 nodeid, struct qstr *name,
261 struct fuse_entry_out *outarg, struct inode **inode)
262 {
263 struct fuse_conn *fc = get_fuse_conn_super(sb);
264 struct fuse_req *req;
265 struct fuse_forget_link *forget;
266 u64 attr_version;
267 int err;
268
269 *inode = NULL;
270 err = -ENAMETOOLONG;
271 if (name->len > FUSE_NAME_MAX)
272 goto out;
273
274 req = fuse_get_req(fc);
275 err = PTR_ERR(req);
276 if (IS_ERR(req))
277 goto out;
278
279 forget = fuse_alloc_forget();
280 err = -ENOMEM;
281 if (!forget) {
282 fuse_put_request(fc, req);
283 goto out;
284 }
285
286 attr_version = fuse_get_attr_version(fc);
287
288 fuse_lookup_init(fc, req, nodeid, name, outarg);
289 fuse_request_send(fc, req);
290 err = req->out.h.error;
291 fuse_put_request(fc, req);
292 /* Zero nodeid is same as -ENOENT, but with valid timeout */
293 if (err || !outarg->nodeid)
294 goto out_put_forget;
295
296 err = -EIO;
297 if (!outarg->nodeid)
298 goto out_put_forget;
299 if (!fuse_valid_type(outarg->attr.mode))
300 goto out_put_forget;
301
302 *inode = fuse_iget(sb, outarg->nodeid, outarg->generation,
303 &outarg->attr, entry_attr_timeout(outarg),
304 attr_version);
305 err = -ENOMEM;
306 if (!*inode) {
307 fuse_queue_forget(fc, forget, outarg->nodeid, 1);
308 goto out;
309 }
310 err = 0;
311
312 out_put_forget:
313 kfree(forget);
314 out:
315 return err;
316 }
317
318 static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry,
319 struct nameidata *nd)
320 {
321 int err;
322 struct fuse_entry_out outarg;
323 struct inode *inode;
324 struct dentry *newent;
325 struct fuse_conn *fc = get_fuse_conn(dir);
326 bool outarg_valid = true;
327
328 err = fuse_lookup_name(dir->i_sb, get_node_id(dir), &entry->d_name,
329 &outarg, &inode);
330 if (err == -ENOENT) {
331 outarg_valid = false;
332 err = 0;
333 }
334 if (err)
335 goto out_err;
336
337 err = -EIO;
338 if (inode && get_node_id(inode) == FUSE_ROOT_ID)
339 goto out_iput;
340
341 if (inode && S_ISDIR(inode->i_mode)) {
342 mutex_lock(&fc->inst_mutex);
343 newent = fuse_d_add_directory(entry, inode);
344 mutex_unlock(&fc->inst_mutex);
345 err = PTR_ERR(newent);
346 if (IS_ERR(newent))
347 goto out_iput;
348 } else {
349 newent = d_splice_alias(inode, entry);
350 }
351
352 entry = newent ? newent : entry;
353 if (outarg_valid)
354 fuse_change_entry_timeout(entry, &outarg);
355 else
356 fuse_invalidate_entry_cache(entry);
357
358 return newent;
359
360 out_iput:
361 iput(inode);
362 out_err:
363 return ERR_PTR(err);
364 }
365
366 /*
367 * Atomic create+open operation
368 *
369 * If the filesystem doesn't support this, then fall back to separate
370 * 'mknod' + 'open' requests.
371 */
372 static int fuse_create_open(struct inode *dir, struct dentry *entry, int mode,
373 struct nameidata *nd)
374 {
375 int err;
376 struct inode *inode;
377 struct fuse_conn *fc = get_fuse_conn(dir);
378 struct fuse_req *req;
379 struct fuse_forget_link *forget;
380 struct fuse_create_in inarg;
381 struct fuse_open_out outopen;
382 struct fuse_entry_out outentry;
383 struct fuse_file *ff;
384 struct file *file;
385 int flags = nd->intent.open.flags - 1;
386
387 if (fc->no_create)
388 return -ENOSYS;
389
390 if (flags & O_DIRECT)
391 return -EINVAL;
392
393 forget = fuse_alloc_forget();
394 if (!forget)
395 return -ENOMEM;
396
397 req = fuse_get_req(fc);
398 err = PTR_ERR(req);
399 if (IS_ERR(req))
400 goto out_put_forget_req;
401
402 err = -ENOMEM;
403 ff = fuse_file_alloc(fc);
404 if (!ff)
405 goto out_put_request;
406
407 if (!fc->dont_mask)
408 mode &= ~current_umask();
409
410 flags &= ~O_NOCTTY;
411 memset(&inarg, 0, sizeof(inarg));
412 memset(&outentry, 0, sizeof(outentry));
413 inarg.flags = flags;
414 inarg.mode = mode;
415 inarg.umask = current_umask();
416 req->in.h.opcode = FUSE_CREATE;
417 req->in.h.nodeid = get_node_id(dir);
418 req->in.numargs = 2;
419 req->in.args[0].size = fc->minor < 12 ? sizeof(struct fuse_open_in) :
420 sizeof(inarg);
421 req->in.args[0].value = &inarg;
422 req->in.args[1].size = entry->d_name.len + 1;
423 req->in.args[1].value = entry->d_name.name;
424 req->out.numargs = 2;
425 if (fc->minor < 9)
426 req->out.args[0].size = FUSE_COMPAT_ENTRY_OUT_SIZE;
427 else
428 req->out.args[0].size = sizeof(outentry);
429 req->out.args[0].value = &outentry;
430 req->out.args[1].size = sizeof(outopen);
431 req->out.args[1].value = &outopen;
432 fuse_request_send(fc, req);
433 err = req->out.h.error;
434 if (err) {
435 if (err == -ENOSYS)
436 fc->no_create = 1;
437 goto out_free_ff;
438 }
439
440 err = -EIO;
441 if (!S_ISREG(outentry.attr.mode) || invalid_nodeid(outentry.nodeid))
442 goto out_free_ff;
443
444 fuse_put_request(fc, req);
445 ff->fh = outopen.fh;
446 ff->nodeid = outentry.nodeid;
447 ff->open_flags = outopen.open_flags;
448 inode = fuse_iget(dir->i_sb, outentry.nodeid, outentry.generation,
449 &outentry.attr, entry_attr_timeout(&outentry), 0);
450 if (!inode) {
451 flags &= ~(O_CREAT | O_EXCL | O_TRUNC);
452 fuse_sync_release(ff, flags);
453 fuse_queue_forget(fc, forget, outentry.nodeid, 1);
454 return -ENOMEM;
455 }
456 kfree(forget);
457 d_instantiate(entry, inode);
458 fuse_change_entry_timeout(entry, &outentry);
459 fuse_invalidate_attr(dir);
460 file = lookup_instantiate_filp(nd, entry, generic_file_open);
461 if (IS_ERR(file)) {
462 fuse_sync_release(ff, flags);
463 return PTR_ERR(file);
464 }
465 file->private_data = fuse_file_get(ff);
466 fuse_finish_open(inode, file);
467 return 0;
468
469 out_free_ff:
470 fuse_file_free(ff);
471 out_put_request:
472 fuse_put_request(fc, req);
473 out_put_forget_req:
474 kfree(forget);
475 return err;
476 }
477
478 /*
479 * Code shared between mknod, mkdir, symlink and link
480 */
481 static int create_new_entry(struct fuse_conn *fc, struct fuse_req *req,
482 struct inode *dir, struct dentry *entry,
483 int mode)
484 {
485 struct fuse_entry_out outarg;
486 struct inode *inode;
487 int err;
488 struct fuse_forget_link *forget;
489
490 forget = fuse_alloc_forget();
491 if (!forget) {
492 fuse_put_request(fc, req);
493 return -ENOMEM;
494 }
495
496 memset(&outarg, 0, sizeof(outarg));
497 req->in.h.nodeid = get_node_id(dir);
498 req->out.numargs = 1;
499 if (fc->minor < 9)
500 req->out.args[0].size = FUSE_COMPAT_ENTRY_OUT_SIZE;
501 else
502 req->out.args[0].size = sizeof(outarg);
503 req->out.args[0].value = &outarg;
504 fuse_request_send(fc, req);
505 err = req->out.h.error;
506 fuse_put_request(fc, req);
507 if (err)
508 goto out_put_forget_req;
509
510 err = -EIO;
511 if (invalid_nodeid(outarg.nodeid))
512 goto out_put_forget_req;
513
514 if ((outarg.attr.mode ^ mode) & S_IFMT)
515 goto out_put_forget_req;
516
517 inode = fuse_iget(dir->i_sb, outarg.nodeid, outarg.generation,
518 &outarg.attr, entry_attr_timeout(&outarg), 0);
519 if (!inode) {
520 fuse_queue_forget(fc, forget, outarg.nodeid, 1);
521 return -ENOMEM;
522 }
523 kfree(forget);
524
525 if (S_ISDIR(inode->i_mode)) {
526 struct dentry *alias;
527 mutex_lock(&fc->inst_mutex);
528 alias = d_find_alias(inode);
529 if (alias) {
530 /* New directory must have moved since mkdir */
531 mutex_unlock(&fc->inst_mutex);
532 dput(alias);
533 iput(inode);
534 return -EBUSY;
535 }
536 d_instantiate(entry, inode);
537 mutex_unlock(&fc->inst_mutex);
538 } else
539 d_instantiate(entry, inode);
540
541 fuse_change_entry_timeout(entry, &outarg);
542 fuse_invalidate_attr(dir);
543 return 0;
544
545 out_put_forget_req:
546 kfree(forget);
547 return err;
548 }
549
550 static int fuse_mknod(struct inode *dir, struct dentry *entry, int mode,
551 dev_t rdev)
552 {
553 struct fuse_mknod_in inarg;
554 struct fuse_conn *fc = get_fuse_conn(dir);
555 struct fuse_req *req = fuse_get_req(fc);
556 if (IS_ERR(req))
557 return PTR_ERR(req);
558
559 if (!fc->dont_mask)
560 mode &= ~current_umask();
561
562 memset(&inarg, 0, sizeof(inarg));
563 inarg.mode = mode;
564 inarg.rdev = new_encode_dev(rdev);
565 inarg.umask = current_umask();
566 req->in.h.opcode = FUSE_MKNOD;
567 req->in.numargs = 2;
568 req->in.args[0].size = fc->minor < 12 ? FUSE_COMPAT_MKNOD_IN_SIZE :
569 sizeof(inarg);
570 req->in.args[0].value = &inarg;
571 req->in.args[1].size = entry->d_name.len + 1;
572 req->in.args[1].value = entry->d_name.name;
573 return create_new_entry(fc, req, dir, entry, mode);
574 }
575
576 static int fuse_create(struct inode *dir, struct dentry *entry, int mode,
577 struct nameidata *nd)
578 {
579 if (nd && (nd->flags & LOOKUP_OPEN)) {
580 int err = fuse_create_open(dir, entry, mode, nd);
581 if (err != -ENOSYS)
582 return err;
583 /* Fall back on mknod */
584 }
585 return fuse_mknod(dir, entry, mode, 0);
586 }
587
588 static int fuse_mkdir(struct inode *dir, struct dentry *entry, int mode)
589 {
590 struct fuse_mkdir_in inarg;
591 struct fuse_conn *fc = get_fuse_conn(dir);
592 struct fuse_req *req = fuse_get_req(fc);
593 if (IS_ERR(req))
594 return PTR_ERR(req);
595
596 if (!fc->dont_mask)
597 mode &= ~current_umask();
598
599 memset(&inarg, 0, sizeof(inarg));
600 inarg.mode = mode;
601 inarg.umask = current_umask();
602 req->in.h.opcode = FUSE_MKDIR;
603 req->in.numargs = 2;
604 req->in.args[0].size = sizeof(inarg);
605 req->in.args[0].value = &inarg;
606 req->in.args[1].size = entry->d_name.len + 1;
607 req->in.args[1].value = entry->d_name.name;
608 return create_new_entry(fc, req, dir, entry, S_IFDIR);
609 }
610
611 static int fuse_symlink(struct inode *dir, struct dentry *entry,
612 const char *link)
613 {
614 struct fuse_conn *fc = get_fuse_conn(dir);
615 unsigned len = strlen(link) + 1;
616 struct fuse_req *req = fuse_get_req(fc);
617 if (IS_ERR(req))
618 return PTR_ERR(req);
619
620 req->in.h.opcode = FUSE_SYMLINK;
621 req->in.numargs = 2;
622 req->in.args[0].size = entry->d_name.len + 1;
623 req->in.args[0].value = entry->d_name.name;
624 req->in.args[1].size = len;
625 req->in.args[1].value = link;
626 return create_new_entry(fc, req, dir, entry, S_IFLNK);
627 }
628
629 static int fuse_unlink(struct inode *dir, struct dentry *entry)
630 {
631 int err;
632 struct fuse_conn *fc = get_fuse_conn(dir);
633 struct fuse_req *req = fuse_get_req(fc);
634 if (IS_ERR(req))
635 return PTR_ERR(req);
636
637 req->in.h.opcode = FUSE_UNLINK;
638 req->in.h.nodeid = get_node_id(dir);
639 req->in.numargs = 1;
640 req->in.args[0].size = entry->d_name.len + 1;
641 req->in.args[0].value = entry->d_name.name;
642 fuse_request_send(fc, req);
643 err = req->out.h.error;
644 fuse_put_request(fc, req);
645 if (!err) {
646 struct inode *inode = entry->d_inode;
647
648 /*
649 * Set nlink to zero so the inode can be cleared, if the inode
650 * does have more links this will be discovered at the next
651 * lookup/getattr.
652 */
653 clear_nlink(inode);
654 fuse_invalidate_attr(inode);
655 fuse_invalidate_attr(dir);
656 fuse_invalidate_entry_cache(entry);
657 } else if (err == -EINTR)
658 fuse_invalidate_entry(entry);
659 return err;
660 }
661
662 static int fuse_rmdir(struct inode *dir, struct dentry *entry)
663 {
664 int err;
665 struct fuse_conn *fc = get_fuse_conn(dir);
666 struct fuse_req *req = fuse_get_req(fc);
667 if (IS_ERR(req))
668 return PTR_ERR(req);
669
670 dentry_unhash(entry);
671
672 req->in.h.opcode = FUSE_RMDIR;
673 req->in.h.nodeid = get_node_id(dir);
674 req->in.numargs = 1;
675 req->in.args[0].size = entry->d_name.len + 1;
676 req->in.args[0].value = entry->d_name.name;
677 fuse_request_send(fc, req);
678 err = req->out.h.error;
679 fuse_put_request(fc, req);
680 if (!err) {
681 clear_nlink(entry->d_inode);
682 fuse_invalidate_attr(dir);
683 fuse_invalidate_entry_cache(entry);
684 } else if (err == -EINTR)
685 fuse_invalidate_entry(entry);
686 return err;
687 }
688
689 static int fuse_rename(struct inode *olddir, struct dentry *oldent,
690 struct inode *newdir, struct dentry *newent)
691 {
692 int err;
693 struct fuse_rename_in inarg;
694 struct fuse_conn *fc = get_fuse_conn(olddir);
695 struct fuse_req *req = fuse_get_req(fc);
696 if (IS_ERR(req))
697 return PTR_ERR(req);
698
699 memset(&inarg, 0, sizeof(inarg));
700 inarg.newdir = get_node_id(newdir);
701 req->in.h.opcode = FUSE_RENAME;
702 req->in.h.nodeid = get_node_id(olddir);
703 req->in.numargs = 3;
704 req->in.args[0].size = sizeof(inarg);
705 req->in.args[0].value = &inarg;
706 req->in.args[1].size = oldent->d_name.len + 1;
707 req->in.args[1].value = oldent->d_name.name;
708 req->in.args[2].size = newent->d_name.len + 1;
709 req->in.args[2].value = newent->d_name.name;
710 fuse_request_send(fc, req);
711 err = req->out.h.error;
712 fuse_put_request(fc, req);
713 if (!err) {
714 /* ctime changes */
715 fuse_invalidate_attr(oldent->d_inode);
716
717 fuse_invalidate_attr(olddir);
718 if (olddir != newdir)
719 fuse_invalidate_attr(newdir);
720
721 /* newent will end up negative */
722 if (newent->d_inode) {
723 fuse_invalidate_attr(newent->d_inode);
724 fuse_invalidate_entry_cache(newent);
725 }
726 } else if (err == -EINTR) {
727 /* If request was interrupted, DEITY only knows if the
728 rename actually took place. If the invalidation
729 fails (e.g. some process has CWD under the renamed
730 directory), then there can be inconsistency between
731 the dcache and the real filesystem. Tough luck. */
732 fuse_invalidate_entry(oldent);
733 if (newent->d_inode)
734 fuse_invalidate_entry(newent);
735 }
736
737 return err;
738 }
739
740 static int fuse_link(struct dentry *entry, struct inode *newdir,
741 struct dentry *newent)
742 {
743 int err;
744 struct fuse_link_in inarg;
745 struct inode *inode = entry->d_inode;
746 struct fuse_conn *fc = get_fuse_conn(inode);
747 struct fuse_req *req = fuse_get_req(fc);
748 if (IS_ERR(req))
749 return PTR_ERR(req);
750
751 memset(&inarg, 0, sizeof(inarg));
752 inarg.oldnodeid = get_node_id(inode);
753 req->in.h.opcode = FUSE_LINK;
754 req->in.numargs = 2;
755 req->in.args[0].size = sizeof(inarg);
756 req->in.args[0].value = &inarg;
757 req->in.args[1].size = newent->d_name.len + 1;
758 req->in.args[1].value = newent->d_name.name;
759 err = create_new_entry(fc, req, newdir, newent, inode->i_mode);
760 /* Contrary to "normal" filesystems it can happen that link
761 makes two "logical" inodes point to the same "physical"
762 inode. We invalidate the attributes of the old one, so it
763 will reflect changes in the backing inode (link count,
764 etc.)
765 */
766 if (!err || err == -EINTR)
767 fuse_invalidate_attr(inode);
768 return err;
769 }
770
771 static void fuse_fillattr(struct inode *inode, struct fuse_attr *attr,
772 struct kstat *stat)
773 {
774 stat->dev = inode->i_sb->s_dev;
775 stat->ino = attr->ino;
776 stat->mode = (inode->i_mode & S_IFMT) | (attr->mode & 07777);
777 stat->nlink = attr->nlink;
778 stat->uid = attr->uid;
779 stat->gid = attr->gid;
780 stat->rdev = inode->i_rdev;
781 stat->atime.tv_sec = attr->atime;
782 stat->atime.tv_nsec = attr->atimensec;
783 stat->mtime.tv_sec = attr->mtime;
784 stat->mtime.tv_nsec = attr->mtimensec;
785 stat->ctime.tv_sec = attr->ctime;
786 stat->ctime.tv_nsec = attr->ctimensec;
787 stat->size = attr->size;
788 stat->blocks = attr->blocks;
789 stat->blksize = (1 << inode->i_blkbits);
790 }
791
792 static int fuse_do_getattr(struct inode *inode, struct kstat *stat,
793 struct file *file)
794 {
795 int err;
796 struct fuse_getattr_in inarg;
797 struct fuse_attr_out outarg;
798 struct fuse_conn *fc = get_fuse_conn(inode);
799 struct fuse_req *req;
800 u64 attr_version;
801
802 req = fuse_get_req(fc);
803 if (IS_ERR(req))
804 return PTR_ERR(req);
805
806 attr_version = fuse_get_attr_version(fc);
807
808 memset(&inarg, 0, sizeof(inarg));
809 memset(&outarg, 0, sizeof(outarg));
810 /* Directories have separate file-handle space */
811 if (file && S_ISREG(inode->i_mode)) {
812 struct fuse_file *ff = file->private_data;
813
814 inarg.getattr_flags |= FUSE_GETATTR_FH;
815 inarg.fh = ff->fh;
816 }
817 req->in.h.opcode = FUSE_GETATTR;
818 req->in.h.nodeid = get_node_id(inode);
819 req->in.numargs = 1;
820 req->in.args[0].size = sizeof(inarg);
821 req->in.args[0].value = &inarg;
822 req->out.numargs = 1;
823 if (fc->minor < 9)
824 req->out.args[0].size = FUSE_COMPAT_ATTR_OUT_SIZE;
825 else
826 req->out.args[0].size = sizeof(outarg);
827 req->out.args[0].value = &outarg;
828 fuse_request_send(fc, req);
829 err = req->out.h.error;
830 fuse_put_request(fc, req);
831 if (!err) {
832 if ((inode->i_mode ^ outarg.attr.mode) & S_IFMT) {
833 make_bad_inode(inode);
834 err = -EIO;
835 } else {
836 fuse_change_attributes(inode, &outarg.attr,
837 attr_timeout(&outarg),
838 attr_version);
839 if (stat)
840 fuse_fillattr(inode, &outarg.attr, stat);
841 }
842 }
843 return err;
844 }
845
846 int fuse_update_attributes(struct inode *inode, struct kstat *stat,
847 struct file *file, bool *refreshed)
848 {
849 struct fuse_inode *fi = get_fuse_inode(inode);
850 int err;
851 bool r;
852
853 if (fi->i_time < get_jiffies_64()) {
854 r = true;
855 err = fuse_do_getattr(inode, stat, file);
856 } else {
857 r = false;
858 err = 0;
859 if (stat) {
860 generic_fillattr(inode, stat);
861 stat->mode = fi->orig_i_mode;
862 }
863 }
864
865 if (refreshed != NULL)
866 *refreshed = r;
867
868 return err;
869 }
870
871 int fuse_reverse_inval_entry(struct super_block *sb, u64 parent_nodeid,
872 struct qstr *name)
873 {
874 int err = -ENOTDIR;
875 struct inode *parent;
876 struct dentry *dir;
877 struct dentry *entry;
878
879 parent = ilookup5(sb, parent_nodeid, fuse_inode_eq, &parent_nodeid);
880 if (!parent)
881 return -ENOENT;
882
883 mutex_lock(&parent->i_mutex);
884 if (!S_ISDIR(parent->i_mode))
885 goto unlock;
886
887 err = -ENOENT;
888 dir = d_find_alias(parent);
889 if (!dir)
890 goto unlock;
891
892 entry = d_lookup(dir, name);
893 dput(dir);
894 if (!entry)
895 goto unlock;
896
897 fuse_invalidate_attr(parent);
898 fuse_invalidate_entry(entry);
899 dput(entry);
900 err = 0;
901
902 unlock:
903 mutex_unlock(&parent->i_mutex);
904 iput(parent);
905 return err;
906 }
907
908 /*
909 * Calling into a user-controlled filesystem gives the filesystem
910 * daemon ptrace-like capabilities over the requester process. This
911 * means, that the filesystem daemon is able to record the exact
912 * filesystem operations performed, and can also control the behavior
913 * of the requester process in otherwise impossible ways. For example
914 * it can delay the operation for arbitrary length of time allowing
915 * DoS against the requester.
916 *
917 * For this reason only those processes can call into the filesystem,
918 * for which the owner of the mount has ptrace privilege. This
919 * excludes processes started by other users, suid or sgid processes.
920 */
921 int fuse_allow_task(struct fuse_conn *fc, struct task_struct *task)
922 {
923 const struct cred *cred;
924 int ret;
925
926 if (fc->flags & FUSE_ALLOW_OTHER)
927 return 1;
928
929 rcu_read_lock();
930 ret = 0;
931 cred = __task_cred(task);
932 if (cred->euid == fc->user_id &&
933 cred->suid == fc->user_id &&
934 cred->uid == fc->user_id &&
935 cred->egid == fc->group_id &&
936 cred->sgid == fc->group_id &&
937 cred->gid == fc->group_id)
938 ret = 1;
939 rcu_read_unlock();
940
941 return ret;
942 }
943
944 static int fuse_access(struct inode *inode, int mask)
945 {
946 struct fuse_conn *fc = get_fuse_conn(inode);
947 struct fuse_req *req;
948 struct fuse_access_in inarg;
949 int err;
950
951 if (fc->no_access)
952 return 0;
953
954 req = fuse_get_req(fc);
955 if (IS_ERR(req))
956 return PTR_ERR(req);
957
958 memset(&inarg, 0, sizeof(inarg));
959 inarg.mask = mask & (MAY_READ | MAY_WRITE | MAY_EXEC);
960 req->in.h.opcode = FUSE_ACCESS;
961 req->in.h.nodeid = get_node_id(inode);
962 req->in.numargs = 1;
963 req->in.args[0].size = sizeof(inarg);
964 req->in.args[0].value = &inarg;
965 fuse_request_send(fc, req);
966 err = req->out.h.error;
967 fuse_put_request(fc, req);
968 if (err == -ENOSYS) {
969 fc->no_access = 1;
970 err = 0;
971 }
972 return err;
973 }
974
975 static int fuse_perm_getattr(struct inode *inode, int flags)
976 {
977 if (flags & IPERM_FLAG_RCU)
978 return -ECHILD;
979
980 return fuse_do_getattr(inode, NULL, NULL);
981 }
982
983 /*
984 * Check permission. The two basic access models of FUSE are:
985 *
986 * 1) Local access checking ('default_permissions' mount option) based
987 * on file mode. This is the plain old disk filesystem permission
988 * modell.
989 *
990 * 2) "Remote" access checking, where server is responsible for
991 * checking permission in each inode operation. An exception to this
992 * is if ->permission() was invoked from sys_access() in which case an
993 * access request is sent. Execute permission is still checked
994 * locally based on file mode.
995 */
996 static int fuse_permission(struct inode *inode, int mask, unsigned int flags)
997 {
998 struct fuse_conn *fc = get_fuse_conn(inode);
999 bool refreshed = false;
1000 int err = 0;
1001
1002 if (!fuse_allow_task(fc, current))
1003 return -EACCES;
1004
1005 /*
1006 * If attributes are needed, refresh them before proceeding
1007 */
1008 if ((fc->flags & FUSE_DEFAULT_PERMISSIONS) ||
1009 ((mask & MAY_EXEC) && S_ISREG(inode->i_mode))) {
1010 struct fuse_inode *fi = get_fuse_inode(inode);
1011
1012 if (fi->i_time < get_jiffies_64()) {
1013 refreshed = true;
1014
1015 err = fuse_perm_getattr(inode, flags);
1016 if (err)
1017 return err;
1018 }
1019 }
1020
1021 if (fc->flags & FUSE_DEFAULT_PERMISSIONS) {
1022 err = generic_permission(inode, mask, flags, NULL);
1023
1024 /* If permission is denied, try to refresh file
1025 attributes. This is also needed, because the root
1026 node will at first have no permissions */
1027 if (err == -EACCES && !refreshed) {
1028 err = fuse_perm_getattr(inode, flags);
1029 if (!err)
1030 err = generic_permission(inode, mask,
1031 flags, NULL);
1032 }
1033
1034 /* Note: the opposite of the above test does not
1035 exist. So if permissions are revoked this won't be
1036 noticed immediately, only after the attribute
1037 timeout has expired */
1038 } else if (mask & (MAY_ACCESS | MAY_CHDIR)) {
1039 if (flags & IPERM_FLAG_RCU)
1040 return -ECHILD;
1041
1042 err = fuse_access(inode, mask);
1043 } else if ((mask & MAY_EXEC) && S_ISREG(inode->i_mode)) {
1044 if (!(inode->i_mode & S_IXUGO)) {
1045 if (refreshed)
1046 return -EACCES;
1047
1048 err = fuse_perm_getattr(inode, flags);
1049 if (!err && !(inode->i_mode & S_IXUGO))
1050 return -EACCES;
1051 }
1052 }
1053 return err;
1054 }
1055
1056 static int parse_dirfile(char *buf, size_t nbytes, struct file *file,
1057 void *dstbuf, filldir_t filldir)
1058 {
1059 while (nbytes >= FUSE_NAME_OFFSET) {
1060 struct fuse_dirent *dirent = (struct fuse_dirent *) buf;
1061 size_t reclen = FUSE_DIRENT_SIZE(dirent);
1062 int over;
1063 if (!dirent->namelen || dirent->namelen > FUSE_NAME_MAX)
1064 return -EIO;
1065 if (reclen > nbytes)
1066 break;
1067
1068 over = filldir(dstbuf, dirent->name, dirent->namelen,
1069 file->f_pos, dirent->ino, dirent->type);
1070 if (over)
1071 break;
1072
1073 buf += reclen;
1074 nbytes -= reclen;
1075 file->f_pos = dirent->off;
1076 }
1077
1078 return 0;
1079 }
1080
1081 static int fuse_readdir(struct file *file, void *dstbuf, filldir_t filldir)
1082 {
1083 int err;
1084 size_t nbytes;
1085 struct page *page;
1086 struct inode *inode = file->f_path.dentry->d_inode;
1087 struct fuse_conn *fc = get_fuse_conn(inode);
1088 struct fuse_req *req;
1089
1090 if (is_bad_inode(inode))
1091 return -EIO;
1092
1093 req = fuse_get_req(fc);
1094 if (IS_ERR(req))
1095 return PTR_ERR(req);
1096
1097 page = alloc_page(GFP_KERNEL);
1098 if (!page) {
1099 fuse_put_request(fc, req);
1100 return -ENOMEM;
1101 }
1102 req->out.argpages = 1;
1103 req->num_pages = 1;
1104 req->pages[0] = page;
1105 fuse_read_fill(req, file, file->f_pos, PAGE_SIZE, FUSE_READDIR);
1106 fuse_request_send(fc, req);
1107 nbytes = req->out.args[0].size;
1108 err = req->out.h.error;
1109 fuse_put_request(fc, req);
1110 if (!err)
1111 err = parse_dirfile(page_address(page), nbytes, file, dstbuf,
1112 filldir);
1113
1114 __free_page(page);
1115 fuse_invalidate_attr(inode); /* atime changed */
1116 return err;
1117 }
1118
1119 static char *read_link(struct dentry *dentry)
1120 {
1121 struct inode *inode = dentry->d_inode;
1122 struct fuse_conn *fc = get_fuse_conn(inode);
1123 struct fuse_req *req = fuse_get_req(fc);
1124 char *link;
1125
1126 if (IS_ERR(req))
1127 return ERR_CAST(req);
1128
1129 link = (char *) __get_free_page(GFP_KERNEL);
1130 if (!link) {
1131 link = ERR_PTR(-ENOMEM);
1132 goto out;
1133 }
1134 req->in.h.opcode = FUSE_READLINK;
1135 req->in.h.nodeid = get_node_id(inode);
1136 req->out.argvar = 1;
1137 req->out.numargs = 1;
1138 req->out.args[0].size = PAGE_SIZE - 1;
1139 req->out.args[0].value = link;
1140 fuse_request_send(fc, req);
1141 if (req->out.h.error) {
1142 free_page((unsigned long) link);
1143 link = ERR_PTR(req->out.h.error);
1144 } else
1145 link[req->out.args[0].size] = '\0';
1146 out:
1147 fuse_put_request(fc, req);
1148 fuse_invalidate_attr(inode); /* atime changed */
1149 return link;
1150 }
1151
1152 static void free_link(char *link)
1153 {
1154 if (!IS_ERR(link))
1155 free_page((unsigned long) link);
1156 }
1157
1158 static void *fuse_follow_link(struct dentry *dentry, struct nameidata *nd)
1159 {
1160 nd_set_link(nd, read_link(dentry));
1161 return NULL;
1162 }
1163
1164 static void fuse_put_link(struct dentry *dentry, struct nameidata *nd, void *c)
1165 {
1166 free_link(nd_get_link(nd));
1167 }
1168
1169 static int fuse_dir_open(struct inode *inode, struct file *file)
1170 {
1171 return fuse_open_common(inode, file, true);
1172 }
1173
1174 static int fuse_dir_release(struct inode *inode, struct file *file)
1175 {
1176 fuse_release_common(file, FUSE_RELEASEDIR);
1177
1178 return 0;
1179 }
1180
1181 static int fuse_dir_fsync(struct file *file, int datasync)
1182 {
1183 return fuse_fsync_common(file, datasync, 1);
1184 }
1185
1186 static bool update_mtime(unsigned ivalid)
1187 {
1188 /* Always update if mtime is explicitly set */
1189 if (ivalid & ATTR_MTIME_SET)
1190 return true;
1191
1192 /* If it's an open(O_TRUNC) or an ftruncate(), don't update */
1193 if ((ivalid & ATTR_SIZE) && (ivalid & (ATTR_OPEN | ATTR_FILE)))
1194 return false;
1195
1196 /* In all other cases update */
1197 return true;
1198 }
1199
1200 static void iattr_to_fattr(struct iattr *iattr, struct fuse_setattr_in *arg)
1201 {
1202 unsigned ivalid = iattr->ia_valid;
1203
1204 if (ivalid & ATTR_MODE)
1205 arg->valid |= FATTR_MODE, arg->mode = iattr->ia_mode;
1206 if (ivalid & ATTR_UID)
1207 arg->valid |= FATTR_UID, arg->uid = iattr->ia_uid;
1208 if (ivalid & ATTR_GID)
1209 arg->valid |= FATTR_GID, arg->gid = iattr->ia_gid;
1210 if (ivalid & ATTR_SIZE)
1211 arg->valid |= FATTR_SIZE, arg->size = iattr->ia_size;
1212 if (ivalid & ATTR_ATIME) {
1213 arg->valid |= FATTR_ATIME;
1214 arg->atime = iattr->ia_atime.tv_sec;
1215 arg->atimensec = iattr->ia_atime.tv_nsec;
1216 if (!(ivalid & ATTR_ATIME_SET))
1217 arg->valid |= FATTR_ATIME_NOW;
1218 }
1219 if ((ivalid & ATTR_MTIME) && update_mtime(ivalid)) {
1220 arg->valid |= FATTR_MTIME;
1221 arg->mtime = iattr->ia_mtime.tv_sec;
1222 arg->mtimensec = iattr->ia_mtime.tv_nsec;
1223 if (!(ivalid & ATTR_MTIME_SET))
1224 arg->valid |= FATTR_MTIME_NOW;
1225 }
1226 }
1227
1228 /*
1229 * Prevent concurrent writepages on inode
1230 *
1231 * This is done by adding a negative bias to the inode write counter
1232 * and waiting for all pending writes to finish.
1233 */
1234 void fuse_set_nowrite(struct inode *inode)
1235 {
1236 struct fuse_conn *fc = get_fuse_conn(inode);
1237 struct fuse_inode *fi = get_fuse_inode(inode);
1238
1239 BUG_ON(!mutex_is_locked(&inode->i_mutex));
1240
1241 spin_lock(&fc->lock);
1242 BUG_ON(fi->writectr < 0);
1243 fi->writectr += FUSE_NOWRITE;
1244 spin_unlock(&fc->lock);
1245 wait_event(fi->page_waitq, fi->writectr == FUSE_NOWRITE);
1246 }
1247
1248 /*
1249 * Allow writepages on inode
1250 *
1251 * Remove the bias from the writecounter and send any queued
1252 * writepages.
1253 */
1254 static void __fuse_release_nowrite(struct inode *inode)
1255 {
1256 struct fuse_inode *fi = get_fuse_inode(inode);
1257
1258 BUG_ON(fi->writectr != FUSE_NOWRITE);
1259 fi->writectr = 0;
1260 fuse_flush_writepages(inode);
1261 }
1262
1263 void fuse_release_nowrite(struct inode *inode)
1264 {
1265 struct fuse_conn *fc = get_fuse_conn(inode);
1266
1267 spin_lock(&fc->lock);
1268 __fuse_release_nowrite(inode);
1269 spin_unlock(&fc->lock);
1270 }
1271
1272 /*
1273 * Set attributes, and at the same time refresh them.
1274 *
1275 * Truncation is slightly complicated, because the 'truncate' request
1276 * may fail, in which case we don't want to touch the mapping.
1277 * vmtruncate() doesn't allow for this case, so do the rlimit checking
1278 * and the actual truncation by hand.
1279 */
1280 static int fuse_do_setattr(struct dentry *entry, struct iattr *attr,
1281 struct file *file)
1282 {
1283 struct inode *inode = entry->d_inode;
1284 struct fuse_conn *fc = get_fuse_conn(inode);
1285 struct fuse_req *req;
1286 struct fuse_setattr_in inarg;
1287 struct fuse_attr_out outarg;
1288 bool is_truncate = false;
1289 loff_t oldsize;
1290 int err;
1291
1292 if (!fuse_allow_task(fc, current))
1293 return -EACCES;
1294
1295 if (!(fc->flags & FUSE_DEFAULT_PERMISSIONS))
1296 attr->ia_valid |= ATTR_FORCE;
1297
1298 err = inode_change_ok(inode, attr);
1299 if (err)
1300 return err;
1301
1302 if (attr->ia_valid & ATTR_OPEN) {
1303 if (fc->atomic_o_trunc)
1304 return 0;
1305 file = NULL;
1306 }
1307
1308 if (attr->ia_valid & ATTR_SIZE)
1309 is_truncate = true;
1310
1311 req = fuse_get_req(fc);
1312 if (IS_ERR(req))
1313 return PTR_ERR(req);
1314
1315 if (is_truncate)
1316 fuse_set_nowrite(inode);
1317
1318 memset(&inarg, 0, sizeof(inarg));
1319 memset(&outarg, 0, sizeof(outarg));
1320 iattr_to_fattr(attr, &inarg);
1321 if (file) {
1322 struct fuse_file *ff = file->private_data;
1323 inarg.valid |= FATTR_FH;
1324 inarg.fh = ff->fh;
1325 }
1326 if (attr->ia_valid & ATTR_SIZE) {
1327 /* For mandatory locking in truncate */
1328 inarg.valid |= FATTR_LOCKOWNER;
1329 inarg.lock_owner = fuse_lock_owner_id(fc, current->files);
1330 }
1331 req->in.h.opcode = FUSE_SETATTR;
1332 req->in.h.nodeid = get_node_id(inode);
1333 req->in.numargs = 1;
1334 req->in.args[0].size = sizeof(inarg);
1335 req->in.args[0].value = &inarg;
1336 req->out.numargs = 1;
1337 if (fc->minor < 9)
1338 req->out.args[0].size = FUSE_COMPAT_ATTR_OUT_SIZE;
1339 else
1340 req->out.args[0].size = sizeof(outarg);
1341 req->out.args[0].value = &outarg;
1342 fuse_request_send(fc, req);
1343 err = req->out.h.error;
1344 fuse_put_request(fc, req);
1345 if (err) {
1346 if (err == -EINTR)
1347 fuse_invalidate_attr(inode);
1348 goto error;
1349 }
1350
1351 if ((inode->i_mode ^ outarg.attr.mode) & S_IFMT) {
1352 make_bad_inode(inode);
1353 err = -EIO;
1354 goto error;
1355 }
1356
1357 spin_lock(&fc->lock);
1358 fuse_change_attributes_common(inode, &outarg.attr,
1359 attr_timeout(&outarg));
1360 oldsize = inode->i_size;
1361 i_size_write(inode, outarg.attr.size);
1362
1363 if (is_truncate) {
1364 /* NOTE: this may release/reacquire fc->lock */
1365 __fuse_release_nowrite(inode);
1366 }
1367 spin_unlock(&fc->lock);
1368
1369 /*
1370 * Only call invalidate_inode_pages2() after removing
1371 * FUSE_NOWRITE, otherwise fuse_launder_page() would deadlock.
1372 */
1373 if (S_ISREG(inode->i_mode) && oldsize != outarg.attr.size) {
1374 truncate_pagecache(inode, oldsize, outarg.attr.size);
1375 invalidate_inode_pages2(inode->i_mapping);
1376 }
1377
1378 return 0;
1379
1380 error:
1381 if (is_truncate)
1382 fuse_release_nowrite(inode);
1383
1384 return err;
1385 }
1386
1387 static int fuse_setattr(struct dentry *entry, struct iattr *attr)
1388 {
1389 if (attr->ia_valid & ATTR_FILE)
1390 return fuse_do_setattr(entry, attr, attr->ia_file);
1391 else
1392 return fuse_do_setattr(entry, attr, NULL);
1393 }
1394
1395 static int fuse_getattr(struct vfsmount *mnt, struct dentry *entry,
1396 struct kstat *stat)
1397 {
1398 struct inode *inode = entry->d_inode;
1399 struct fuse_conn *fc = get_fuse_conn(inode);
1400
1401 if (!fuse_allow_task(fc, current))
1402 return -EACCES;
1403
1404 return fuse_update_attributes(inode, stat, NULL, NULL);
1405 }
1406
1407 static int fuse_setxattr(struct dentry *entry, const char *name,
1408 const void *value, size_t size, int flags)
1409 {
1410 struct inode *inode = entry->d_inode;
1411 struct fuse_conn *fc = get_fuse_conn(inode);
1412 struct fuse_req *req;
1413 struct fuse_setxattr_in inarg;
1414 int err;
1415
1416 if (fc->no_setxattr)
1417 return -EOPNOTSUPP;
1418
1419 req = fuse_get_req(fc);
1420 if (IS_ERR(req))
1421 return PTR_ERR(req);
1422
1423 memset(&inarg, 0, sizeof(inarg));
1424 inarg.size = size;
1425 inarg.flags = flags;
1426 req->in.h.opcode = FUSE_SETXATTR;
1427 req->in.h.nodeid = get_node_id(inode);
1428 req->in.numargs = 3;
1429 req->in.args[0].size = sizeof(inarg);
1430 req->in.args[0].value = &inarg;
1431 req->in.args[1].size = strlen(name) + 1;
1432 req->in.args[1].value = name;
1433 req->in.args[2].size = size;
1434 req->in.args[2].value = value;
1435 fuse_request_send(fc, req);
1436 err = req->out.h.error;
1437 fuse_put_request(fc, req);
1438 if (err == -ENOSYS) {
1439 fc->no_setxattr = 1;
1440 err = -EOPNOTSUPP;
1441 }
1442 return err;
1443 }
1444
1445 static ssize_t fuse_getxattr(struct dentry *entry, const char *name,
1446 void *value, size_t size)
1447 {
1448 struct inode *inode = entry->d_inode;
1449 struct fuse_conn *fc = get_fuse_conn(inode);
1450 struct fuse_req *req;
1451 struct fuse_getxattr_in inarg;
1452 struct fuse_getxattr_out outarg;
1453 ssize_t ret;
1454
1455 if (fc->no_getxattr)
1456 return -EOPNOTSUPP;
1457
1458 req = fuse_get_req(fc);
1459 if (IS_ERR(req))
1460 return PTR_ERR(req);
1461
1462 memset(&inarg, 0, sizeof(inarg));
1463 inarg.size = size;
1464 req->in.h.opcode = FUSE_GETXATTR;
1465 req->in.h.nodeid = get_node_id(inode);
1466 req->in.numargs = 2;
1467 req->in.args[0].size = sizeof(inarg);
1468 req->in.args[0].value = &inarg;
1469 req->in.args[1].size = strlen(name) + 1;
1470 req->in.args[1].value = name;
1471 /* This is really two different operations rolled into one */
1472 req->out.numargs = 1;
1473 if (size) {
1474 req->out.argvar = 1;
1475 req->out.args[0].size = size;
1476 req->out.args[0].value = value;
1477 } else {
1478 req->out.args[0].size = sizeof(outarg);
1479 req->out.args[0].value = &outarg;
1480 }
1481 fuse_request_send(fc, req);
1482 ret = req->out.h.error;
1483 if (!ret)
1484 ret = size ? req->out.args[0].size : outarg.size;
1485 else {
1486 if (ret == -ENOSYS) {
1487 fc->no_getxattr = 1;
1488 ret = -EOPNOTSUPP;
1489 }
1490 }
1491 fuse_put_request(fc, req);
1492 return ret;
1493 }
1494
1495 static ssize_t fuse_listxattr(struct dentry *entry, char *list, size_t size)
1496 {
1497 struct inode *inode = entry->d_inode;
1498 struct fuse_conn *fc = get_fuse_conn(inode);
1499 struct fuse_req *req;
1500 struct fuse_getxattr_in inarg;
1501 struct fuse_getxattr_out outarg;
1502 ssize_t ret;
1503
1504 if (!fuse_allow_task(fc, current))
1505 return -EACCES;
1506
1507 if (fc->no_listxattr)
1508 return -EOPNOTSUPP;
1509
1510 req = fuse_get_req(fc);
1511 if (IS_ERR(req))
1512 return PTR_ERR(req);
1513
1514 memset(&inarg, 0, sizeof(inarg));
1515 inarg.size = size;
1516 req->in.h.opcode = FUSE_LISTXATTR;
1517 req->in.h.nodeid = get_node_id(inode);
1518 req->in.numargs = 1;
1519 req->in.args[0].size = sizeof(inarg);
1520 req->in.args[0].value = &inarg;
1521 /* This is really two different operations rolled into one */
1522 req->out.numargs = 1;
1523 if (size) {
1524 req->out.argvar = 1;
1525 req->out.args[0].size = size;
1526 req->out.args[0].value = list;
1527 } else {
1528 req->out.args[0].size = sizeof(outarg);
1529 req->out.args[0].value = &outarg;
1530 }
1531 fuse_request_send(fc, req);
1532 ret = req->out.h.error;
1533 if (!ret)
1534 ret = size ? req->out.args[0].size : outarg.size;
1535 else {
1536 if (ret == -ENOSYS) {
1537 fc->no_listxattr = 1;
1538 ret = -EOPNOTSUPP;
1539 }
1540 }
1541 fuse_put_request(fc, req);
1542 return ret;
1543 }
1544
1545 static int fuse_removexattr(struct dentry *entry, const char *name)
1546 {
1547 struct inode *inode = entry->d_inode;
1548 struct fuse_conn *fc = get_fuse_conn(inode);
1549 struct fuse_req *req;
1550 int err;
1551
1552 if (fc->no_removexattr)
1553 return -EOPNOTSUPP;
1554
1555 req = fuse_get_req(fc);
1556 if (IS_ERR(req))
1557 return PTR_ERR(req);
1558
1559 req->in.h.opcode = FUSE_REMOVEXATTR;
1560 req->in.h.nodeid = get_node_id(inode);
1561 req->in.numargs = 1;
1562 req->in.args[0].size = strlen(name) + 1;
1563 req->in.args[0].value = name;
1564 fuse_request_send(fc, req);
1565 err = req->out.h.error;
1566 fuse_put_request(fc, req);
1567 if (err == -ENOSYS) {
1568 fc->no_removexattr = 1;
1569 err = -EOPNOTSUPP;
1570 }
1571 return err;
1572 }
1573
1574 static const struct inode_operations fuse_dir_inode_operations = {
1575 .lookup = fuse_lookup,
1576 .mkdir = fuse_mkdir,
1577 .symlink = fuse_symlink,
1578 .unlink = fuse_unlink,
1579 .rmdir = fuse_rmdir,
1580 .rename = fuse_rename,
1581 .link = fuse_link,
1582 .setattr = fuse_setattr,
1583 .create = fuse_create,
1584 .mknod = fuse_mknod,
1585 .permission = fuse_permission,
1586 .getattr = fuse_getattr,
1587 .setxattr = fuse_setxattr,
1588 .getxattr = fuse_getxattr,
1589 .listxattr = fuse_listxattr,
1590 .removexattr = fuse_removexattr,
1591 };
1592
1593 static const struct file_operations fuse_dir_operations = {
1594 .llseek = generic_file_llseek,
1595 .read = generic_read_dir,
1596 .readdir = fuse_readdir,
1597 .open = fuse_dir_open,
1598 .release = fuse_dir_release,
1599 .fsync = fuse_dir_fsync,
1600 };
1601
1602 static const struct inode_operations fuse_common_inode_operations = {
1603 .setattr = fuse_setattr,
1604 .permission = fuse_permission,
1605 .getattr = fuse_getattr,
1606 .setxattr = fuse_setxattr,
1607 .getxattr = fuse_getxattr,
1608 .listxattr = fuse_listxattr,
1609 .removexattr = fuse_removexattr,
1610 };
1611
1612 static const struct inode_operations fuse_symlink_inode_operations = {
1613 .setattr = fuse_setattr,
1614 .follow_link = fuse_follow_link,
1615 .put_link = fuse_put_link,
1616 .readlink = generic_readlink,
1617 .getattr = fuse_getattr,
1618 .setxattr = fuse_setxattr,
1619 .getxattr = fuse_getxattr,
1620 .listxattr = fuse_listxattr,
1621 .removexattr = fuse_removexattr,
1622 };
1623
1624 void fuse_init_common(struct inode *inode)
1625 {
1626 inode->i_op = &fuse_common_inode_operations;
1627 }
1628
1629 void fuse_init_dir(struct inode *inode)
1630 {
1631 inode->i_op = &fuse_dir_inode_operations;
1632 inode->i_fop = &fuse_dir_operations;
1633 }
1634
1635 void fuse_init_symlink(struct inode *inode)
1636 {
1637 inode->i_op = &fuse_symlink_inode_operations;
1638 }
Linux kernel - Deliverables
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