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s390/pfault: add sanity check
[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 && (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,
373 umode_t mode, 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;
386
387 if (fc->no_create)
388 return -ENOSYS;
389
390 forget = fuse_alloc_forget();
391 if (!forget)
392 return -ENOMEM;
393
394 req = fuse_get_req(fc);
395 err = PTR_ERR(req);
396 if (IS_ERR(req))
397 goto out_put_forget_req;
398
399 err = -ENOMEM;
400 ff = fuse_file_alloc(fc);
401 if (!ff)
402 goto out_put_request;
403
404 if (!fc->dont_mask)
405 mode &= ~current_umask();
406
407 flags &= ~O_NOCTTY;
408 memset(&inarg, 0, sizeof(inarg));
409 memset(&outentry, 0, sizeof(outentry));
410 inarg.flags = flags;
411 inarg.mode = mode;
412 inarg.umask = current_umask();
413 req->in.h.opcode = FUSE_CREATE;
414 req->in.h.nodeid = get_node_id(dir);
415 req->in.numargs = 2;
416 req->in.args[0].size = fc->minor < 12 ? sizeof(struct fuse_open_in) :
417 sizeof(inarg);
418 req->in.args[0].value = &inarg;
419 req->in.args[1].size = entry->d_name.len + 1;
420 req->in.args[1].value = entry->d_name.name;
421 req->out.numargs = 2;
422 if (fc->minor < 9)
423 req->out.args[0].size = FUSE_COMPAT_ENTRY_OUT_SIZE;
424 else
425 req->out.args[0].size = sizeof(outentry);
426 req->out.args[0].value = &outentry;
427 req->out.args[1].size = sizeof(outopen);
428 req->out.args[1].value = &outopen;
429 fuse_request_send(fc, req);
430 err = req->out.h.error;
431 if (err) {
432 if (err == -ENOSYS)
433 fc->no_create = 1;
434 goto out_free_ff;
435 }
436
437 err = -EIO;
438 if (!S_ISREG(outentry.attr.mode) || invalid_nodeid(outentry.nodeid))
439 goto out_free_ff;
440
441 fuse_put_request(fc, req);
442 ff->fh = outopen.fh;
443 ff->nodeid = outentry.nodeid;
444 ff->open_flags = outopen.open_flags;
445 inode = fuse_iget(dir->i_sb, outentry.nodeid, outentry.generation,
446 &outentry.attr, entry_attr_timeout(&outentry), 0);
447 if (!inode) {
448 flags &= ~(O_CREAT | O_EXCL | O_TRUNC);
449 fuse_sync_release(ff, flags);
450 fuse_queue_forget(fc, forget, outentry.nodeid, 1);
451 return -ENOMEM;
452 }
453 kfree(forget);
454 d_instantiate(entry, inode);
455 fuse_change_entry_timeout(entry, &outentry);
456 fuse_invalidate_attr(dir);
457 file = lookup_instantiate_filp(nd, entry, generic_file_open);
458 if (IS_ERR(file)) {
459 fuse_sync_release(ff, flags);
460 return PTR_ERR(file);
461 }
462 file->private_data = fuse_file_get(ff);
463 fuse_finish_open(inode, file);
464 return 0;
465
466 out_free_ff:
467 fuse_file_free(ff);
468 out_put_request:
469 fuse_put_request(fc, req);
470 out_put_forget_req:
471 kfree(forget);
472 return err;
473 }
474
475 /*
476 * Code shared between mknod, mkdir, symlink and link
477 */
478 static int create_new_entry(struct fuse_conn *fc, struct fuse_req *req,
479 struct inode *dir, struct dentry *entry,
480 umode_t mode)
481 {
482 struct fuse_entry_out outarg;
483 struct inode *inode;
484 int err;
485 struct fuse_forget_link *forget;
486
487 forget = fuse_alloc_forget();
488 if (!forget) {
489 fuse_put_request(fc, req);
490 return -ENOMEM;
491 }
492
493 memset(&outarg, 0, sizeof(outarg));
494 req->in.h.nodeid = get_node_id(dir);
495 req->out.numargs = 1;
496 if (fc->minor < 9)
497 req->out.args[0].size = FUSE_COMPAT_ENTRY_OUT_SIZE;
498 else
499 req->out.args[0].size = sizeof(outarg);
500 req->out.args[0].value = &outarg;
501 fuse_request_send(fc, req);
502 err = req->out.h.error;
503 fuse_put_request(fc, req);
504 if (err)
505 goto out_put_forget_req;
506
507 err = -EIO;
508 if (invalid_nodeid(outarg.nodeid))
509 goto out_put_forget_req;
510
511 if ((outarg.attr.mode ^ mode) & S_IFMT)
512 goto out_put_forget_req;
513
514 inode = fuse_iget(dir->i_sb, outarg.nodeid, outarg.generation,
515 &outarg.attr, entry_attr_timeout(&outarg), 0);
516 if (!inode) {
517 fuse_queue_forget(fc, forget, outarg.nodeid, 1);
518 return -ENOMEM;
519 }
520 kfree(forget);
521
522 if (S_ISDIR(inode->i_mode)) {
523 struct dentry *alias;
524 mutex_lock(&fc->inst_mutex);
525 alias = d_find_alias(inode);
526 if (alias) {
527 /* New directory must have moved since mkdir */
528 mutex_unlock(&fc->inst_mutex);
529 dput(alias);
530 iput(inode);
531 return -EBUSY;
532 }
533 d_instantiate(entry, inode);
534 mutex_unlock(&fc->inst_mutex);
535 } else
536 d_instantiate(entry, inode);
537
538 fuse_change_entry_timeout(entry, &outarg);
539 fuse_invalidate_attr(dir);
540 return 0;
541
542 out_put_forget_req:
543 kfree(forget);
544 return err;
545 }
546
547 static int fuse_mknod(struct inode *dir, struct dentry *entry, umode_t mode,
548 dev_t rdev)
549 {
550 struct fuse_mknod_in inarg;
551 struct fuse_conn *fc = get_fuse_conn(dir);
552 struct fuse_req *req = fuse_get_req(fc);
553 if (IS_ERR(req))
554 return PTR_ERR(req);
555
556 if (!fc->dont_mask)
557 mode &= ~current_umask();
558
559 memset(&inarg, 0, sizeof(inarg));
560 inarg.mode = mode;
561 inarg.rdev = new_encode_dev(rdev);
562 inarg.umask = current_umask();
563 req->in.h.opcode = FUSE_MKNOD;
564 req->in.numargs = 2;
565 req->in.args[0].size = fc->minor < 12 ? FUSE_COMPAT_MKNOD_IN_SIZE :
566 sizeof(inarg);
567 req->in.args[0].value = &inarg;
568 req->in.args[1].size = entry->d_name.len + 1;
569 req->in.args[1].value = entry->d_name.name;
570 return create_new_entry(fc, req, dir, entry, mode);
571 }
572
573 static int fuse_create(struct inode *dir, struct dentry *entry, umode_t mode,
574 struct nameidata *nd)
575 {
576 if (nd) {
577 int err = fuse_create_open(dir, entry, mode, nd);
578 if (err != -ENOSYS)
579 return err;
580 /* Fall back on mknod */
581 }
582 return fuse_mknod(dir, entry, mode, 0);
583 }
584
585 static int fuse_mkdir(struct inode *dir, struct dentry *entry, umode_t mode)
586 {
587 struct fuse_mkdir_in inarg;
588 struct fuse_conn *fc = get_fuse_conn(dir);
589 struct fuse_req *req = fuse_get_req(fc);
590 if (IS_ERR(req))
591 return PTR_ERR(req);
592
593 if (!fc->dont_mask)
594 mode &= ~current_umask();
595
596 memset(&inarg, 0, sizeof(inarg));
597 inarg.mode = mode;
598 inarg.umask = current_umask();
599 req->in.h.opcode = FUSE_MKDIR;
600 req->in.numargs = 2;
601 req->in.args[0].size = sizeof(inarg);
602 req->in.args[0].value = &inarg;
603 req->in.args[1].size = entry->d_name.len + 1;
604 req->in.args[1].value = entry->d_name.name;
605 return create_new_entry(fc, req, dir, entry, S_IFDIR);
606 }
607
608 static int fuse_symlink(struct inode *dir, struct dentry *entry,
609 const char *link)
610 {
611 struct fuse_conn *fc = get_fuse_conn(dir);
612 unsigned len = strlen(link) + 1;
613 struct fuse_req *req = fuse_get_req(fc);
614 if (IS_ERR(req))
615 return PTR_ERR(req);
616
617 req->in.h.opcode = FUSE_SYMLINK;
618 req->in.numargs = 2;
619 req->in.args[0].size = entry->d_name.len + 1;
620 req->in.args[0].value = entry->d_name.name;
621 req->in.args[1].size = len;
622 req->in.args[1].value = link;
623 return create_new_entry(fc, req, dir, entry, S_IFLNK);
624 }
625
626 static int fuse_unlink(struct inode *dir, struct dentry *entry)
627 {
628 int err;
629 struct fuse_conn *fc = get_fuse_conn(dir);
630 struct fuse_req *req = fuse_get_req(fc);
631 if (IS_ERR(req))
632 return PTR_ERR(req);
633
634 req->in.h.opcode = FUSE_UNLINK;
635 req->in.h.nodeid = get_node_id(dir);
636 req->in.numargs = 1;
637 req->in.args[0].size = entry->d_name.len + 1;
638 req->in.args[0].value = entry->d_name.name;
639 fuse_request_send(fc, req);
640 err = req->out.h.error;
641 fuse_put_request(fc, req);
642 if (!err) {
643 struct inode *inode = entry->d_inode;
644 struct fuse_inode *fi = get_fuse_inode(inode);
645
646 spin_lock(&fc->lock);
647 fi->attr_version = ++fc->attr_version;
648 drop_nlink(inode);
649 spin_unlock(&fc->lock);
650 fuse_invalidate_attr(inode);
651 fuse_invalidate_attr(dir);
652 fuse_invalidate_entry_cache(entry);
653 } else if (err == -EINTR)
654 fuse_invalidate_entry(entry);
655 return err;
656 }
657
658 static int fuse_rmdir(struct inode *dir, struct dentry *entry)
659 {
660 int err;
661 struct fuse_conn *fc = get_fuse_conn(dir);
662 struct fuse_req *req = fuse_get_req(fc);
663 if (IS_ERR(req))
664 return PTR_ERR(req);
665
666 req->in.h.opcode = FUSE_RMDIR;
667 req->in.h.nodeid = get_node_id(dir);
668 req->in.numargs = 1;
669 req->in.args[0].size = entry->d_name.len + 1;
670 req->in.args[0].value = entry->d_name.name;
671 fuse_request_send(fc, req);
672 err = req->out.h.error;
673 fuse_put_request(fc, req);
674 if (!err) {
675 clear_nlink(entry->d_inode);
676 fuse_invalidate_attr(dir);
677 fuse_invalidate_entry_cache(entry);
678 } else if (err == -EINTR)
679 fuse_invalidate_entry(entry);
680 return err;
681 }
682
683 static int fuse_rename(struct inode *olddir, struct dentry *oldent,
684 struct inode *newdir, struct dentry *newent)
685 {
686 int err;
687 struct fuse_rename_in inarg;
688 struct fuse_conn *fc = get_fuse_conn(olddir);
689 struct fuse_req *req = fuse_get_req(fc);
690
691 if (IS_ERR(req))
692 return PTR_ERR(req);
693
694 memset(&inarg, 0, sizeof(inarg));
695 inarg.newdir = get_node_id(newdir);
696 req->in.h.opcode = FUSE_RENAME;
697 req->in.h.nodeid = get_node_id(olddir);
698 req->in.numargs = 3;
699 req->in.args[0].size = sizeof(inarg);
700 req->in.args[0].value = &inarg;
701 req->in.args[1].size = oldent->d_name.len + 1;
702 req->in.args[1].value = oldent->d_name.name;
703 req->in.args[2].size = newent->d_name.len + 1;
704 req->in.args[2].value = newent->d_name.name;
705 fuse_request_send(fc, req);
706 err = req->out.h.error;
707 fuse_put_request(fc, req);
708 if (!err) {
709 /* ctime changes */
710 fuse_invalidate_attr(oldent->d_inode);
711
712 fuse_invalidate_attr(olddir);
713 if (olddir != newdir)
714 fuse_invalidate_attr(newdir);
715
716 /* newent will end up negative */
717 if (newent->d_inode) {
718 fuse_invalidate_attr(newent->d_inode);
719 fuse_invalidate_entry_cache(newent);
720 }
721 } else if (err == -EINTR) {
722 /* If request was interrupted, DEITY only knows if the
723 rename actually took place. If the invalidation
724 fails (e.g. some process has CWD under the renamed
725 directory), then there can be inconsistency between
726 the dcache and the real filesystem. Tough luck. */
727 fuse_invalidate_entry(oldent);
728 if (newent->d_inode)
729 fuse_invalidate_entry(newent);
730 }
731
732 return err;
733 }
734
735 static int fuse_link(struct dentry *entry, struct inode *newdir,
736 struct dentry *newent)
737 {
738 int err;
739 struct fuse_link_in inarg;
740 struct inode *inode = entry->d_inode;
741 struct fuse_conn *fc = get_fuse_conn(inode);
742 struct fuse_req *req = fuse_get_req(fc);
743 if (IS_ERR(req))
744 return PTR_ERR(req);
745
746 memset(&inarg, 0, sizeof(inarg));
747 inarg.oldnodeid = get_node_id(inode);
748 req->in.h.opcode = FUSE_LINK;
749 req->in.numargs = 2;
750 req->in.args[0].size = sizeof(inarg);
751 req->in.args[0].value = &inarg;
752 req->in.args[1].size = newent->d_name.len + 1;
753 req->in.args[1].value = newent->d_name.name;
754 err = create_new_entry(fc, req, newdir, newent, inode->i_mode);
755 /* Contrary to "normal" filesystems it can happen that link
756 makes two "logical" inodes point to the same "physical"
757 inode. We invalidate the attributes of the old one, so it
758 will reflect changes in the backing inode (link count,
759 etc.)
760 */
761 if (!err) {
762 struct fuse_inode *fi = get_fuse_inode(inode);
763
764 spin_lock(&fc->lock);
765 fi->attr_version = ++fc->attr_version;
766 inc_nlink(inode);
767 spin_unlock(&fc->lock);
768 fuse_invalidate_attr(inode);
769 } else if (err == -EINTR) {
770 fuse_invalidate_attr(inode);
771 }
772 return err;
773 }
774
775 static void fuse_fillattr(struct inode *inode, struct fuse_attr *attr,
776 struct kstat *stat)
777 {
778 stat->dev = inode->i_sb->s_dev;
779 stat->ino = attr->ino;
780 stat->mode = (inode->i_mode & S_IFMT) | (attr->mode & 07777);
781 stat->nlink = attr->nlink;
782 stat->uid = attr->uid;
783 stat->gid = attr->gid;
784 stat->rdev = inode->i_rdev;
785 stat->atime.tv_sec = attr->atime;
786 stat->atime.tv_nsec = attr->atimensec;
787 stat->mtime.tv_sec = attr->mtime;
788 stat->mtime.tv_nsec = attr->mtimensec;
789 stat->ctime.tv_sec = attr->ctime;
790 stat->ctime.tv_nsec = attr->ctimensec;
791 stat->size = attr->size;
792 stat->blocks = attr->blocks;
793 stat->blksize = (1 << inode->i_blkbits);
794 }
795
796 static int fuse_do_getattr(struct inode *inode, struct kstat *stat,
797 struct file *file)
798 {
799 int err;
800 struct fuse_getattr_in inarg;
801 struct fuse_attr_out outarg;
802 struct fuse_conn *fc = get_fuse_conn(inode);
803 struct fuse_req *req;
804 u64 attr_version;
805
806 req = fuse_get_req(fc);
807 if (IS_ERR(req))
808 return PTR_ERR(req);
809
810 attr_version = fuse_get_attr_version(fc);
811
812 memset(&inarg, 0, sizeof(inarg));
813 memset(&outarg, 0, sizeof(outarg));
814 /* Directories have separate file-handle space */
815 if (file && S_ISREG(inode->i_mode)) {
816 struct fuse_file *ff = file->private_data;
817
818 inarg.getattr_flags |= FUSE_GETATTR_FH;
819 inarg.fh = ff->fh;
820 }
821 req->in.h.opcode = FUSE_GETATTR;
822 req->in.h.nodeid = get_node_id(inode);
823 req->in.numargs = 1;
824 req->in.args[0].size = sizeof(inarg);
825 req->in.args[0].value = &inarg;
826 req->out.numargs = 1;
827 if (fc->minor < 9)
828 req->out.args[0].size = FUSE_COMPAT_ATTR_OUT_SIZE;
829 else
830 req->out.args[0].size = sizeof(outarg);
831 req->out.args[0].value = &outarg;
832 fuse_request_send(fc, req);
833 err = req->out.h.error;
834 fuse_put_request(fc, req);
835 if (!err) {
836 if ((inode->i_mode ^ outarg.attr.mode) & S_IFMT) {
837 make_bad_inode(inode);
838 err = -EIO;
839 } else {
840 fuse_change_attributes(inode, &outarg.attr,
841 attr_timeout(&outarg),
842 attr_version);
843 if (stat)
844 fuse_fillattr(inode, &outarg.attr, stat);
845 }
846 }
847 return err;
848 }
849
850 int fuse_update_attributes(struct inode *inode, struct kstat *stat,
851 struct file *file, bool *refreshed)
852 {
853 struct fuse_inode *fi = get_fuse_inode(inode);
854 int err;
855 bool r;
856
857 if (fi->i_time < get_jiffies_64()) {
858 r = true;
859 err = fuse_do_getattr(inode, stat, file);
860 } else {
861 r = false;
862 err = 0;
863 if (stat) {
864 generic_fillattr(inode, stat);
865 stat->mode = fi->orig_i_mode;
866 }
867 }
868
869 if (refreshed != NULL)
870 *refreshed = r;
871
872 return err;
873 }
874
875 int fuse_reverse_inval_entry(struct super_block *sb, u64 parent_nodeid,
876 u64 child_nodeid, struct qstr *name)
877 {
878 int err = -ENOTDIR;
879 struct inode *parent;
880 struct dentry *dir;
881 struct dentry *entry;
882
883 parent = ilookup5(sb, parent_nodeid, fuse_inode_eq, &parent_nodeid);
884 if (!parent)
885 return -ENOENT;
886
887 mutex_lock(&parent->i_mutex);
888 if (!S_ISDIR(parent->i_mode))
889 goto unlock;
890
891 err = -ENOENT;
892 dir = d_find_alias(parent);
893 if (!dir)
894 goto unlock;
895
896 entry = d_lookup(dir, name);
897 dput(dir);
898 if (!entry)
899 goto unlock;
900
901 fuse_invalidate_attr(parent);
902 fuse_invalidate_entry(entry);
903
904 if (child_nodeid != 0 && entry->d_inode) {
905 mutex_lock(&entry->d_inode->i_mutex);
906 if (get_node_id(entry->d_inode) != child_nodeid) {
907 err = -ENOENT;
908 goto badentry;
909 }
910 if (d_mountpoint(entry)) {
911 err = -EBUSY;
912 goto badentry;
913 }
914 if (S_ISDIR(entry->d_inode->i_mode)) {
915 shrink_dcache_parent(entry);
916 if (!simple_empty(entry)) {
917 err = -ENOTEMPTY;
918 goto badentry;
919 }
920 entry->d_inode->i_flags |= S_DEAD;
921 }
922 dont_mount(entry);
923 clear_nlink(entry->d_inode);
924 err = 0;
925 badentry:
926 mutex_unlock(&entry->d_inode->i_mutex);
927 if (!err)
928 d_delete(entry);
929 } else {
930 err = 0;
931 }
932 dput(entry);
933
934 unlock:
935 mutex_unlock(&parent->i_mutex);
936 iput(parent);
937 return err;
938 }
939
940 /*
941 * Calling into a user-controlled filesystem gives the filesystem
942 * daemon ptrace-like capabilities over the requester process. This
943 * means, that the filesystem daemon is able to record the exact
944 * filesystem operations performed, and can also control the behavior
945 * of the requester process in otherwise impossible ways. For example
946 * it can delay the operation for arbitrary length of time allowing
947 * DoS against the requester.
948 *
949 * For this reason only those processes can call into the filesystem,
950 * for which the owner of the mount has ptrace privilege. This
951 * excludes processes started by other users, suid or sgid processes.
952 */
953 int fuse_allow_task(struct fuse_conn *fc, struct task_struct *task)
954 {
955 const struct cred *cred;
956 int ret;
957
958 if (fc->flags & FUSE_ALLOW_OTHER)
959 return 1;
960
961 rcu_read_lock();
962 ret = 0;
963 cred = __task_cred(task);
964 if (cred->euid == fc->user_id &&
965 cred->suid == fc->user_id &&
966 cred->uid == fc->user_id &&
967 cred->egid == fc->group_id &&
968 cred->sgid == fc->group_id &&
969 cred->gid == fc->group_id)
970 ret = 1;
971 rcu_read_unlock();
972
973 return ret;
974 }
975
976 static int fuse_access(struct inode *inode, int mask)
977 {
978 struct fuse_conn *fc = get_fuse_conn(inode);
979 struct fuse_req *req;
980 struct fuse_access_in inarg;
981 int err;
982
983 if (fc->no_access)
984 return 0;
985
986 req = fuse_get_req(fc);
987 if (IS_ERR(req))
988 return PTR_ERR(req);
989
990 memset(&inarg, 0, sizeof(inarg));
991 inarg.mask = mask & (MAY_READ | MAY_WRITE | MAY_EXEC);
992 req->in.h.opcode = FUSE_ACCESS;
993 req->in.h.nodeid = get_node_id(inode);
994 req->in.numargs = 1;
995 req->in.args[0].size = sizeof(inarg);
996 req->in.args[0].value = &inarg;
997 fuse_request_send(fc, req);
998 err = req->out.h.error;
999 fuse_put_request(fc, req);
1000 if (err == -ENOSYS) {
1001 fc->no_access = 1;
1002 err = 0;
1003 }
1004 return err;
1005 }
1006
1007 static int fuse_perm_getattr(struct inode *inode, int mask)
1008 {
1009 if (mask & MAY_NOT_BLOCK)
1010 return -ECHILD;
1011
1012 return fuse_do_getattr(inode, NULL, NULL);
1013 }
1014
1015 /*
1016 * Check permission. The two basic access models of FUSE are:
1017 *
1018 * 1) Local access checking ('default_permissions' mount option) based
1019 * on file mode. This is the plain old disk filesystem permission
1020 * modell.
1021 *
1022 * 2) "Remote" access checking, where server is responsible for
1023 * checking permission in each inode operation. An exception to this
1024 * is if ->permission() was invoked from sys_access() in which case an
1025 * access request is sent. Execute permission is still checked
1026 * locally based on file mode.
1027 */
1028 static int fuse_permission(struct inode *inode, int mask)
1029 {
1030 struct fuse_conn *fc = get_fuse_conn(inode);
1031 bool refreshed = false;
1032 int err = 0;
1033
1034 if (!fuse_allow_task(fc, current))
1035 return -EACCES;
1036
1037 /*
1038 * If attributes are needed, refresh them before proceeding
1039 */
1040 if ((fc->flags & FUSE_DEFAULT_PERMISSIONS) ||
1041 ((mask & MAY_EXEC) && S_ISREG(inode->i_mode))) {
1042 struct fuse_inode *fi = get_fuse_inode(inode);
1043
1044 if (fi->i_time < get_jiffies_64()) {
1045 refreshed = true;
1046
1047 err = fuse_perm_getattr(inode, mask);
1048 if (err)
1049 return err;
1050 }
1051 }
1052
1053 if (fc->flags & FUSE_DEFAULT_PERMISSIONS) {
1054 err = generic_permission(inode, mask);
1055
1056 /* If permission is denied, try to refresh file
1057 attributes. This is also needed, because the root
1058 node will at first have no permissions */
1059 if (err == -EACCES && !refreshed) {
1060 err = fuse_perm_getattr(inode, mask);
1061 if (!err)
1062 err = generic_permission(inode, mask);
1063 }
1064
1065 /* Note: the opposite of the above test does not
1066 exist. So if permissions are revoked this won't be
1067 noticed immediately, only after the attribute
1068 timeout has expired */
1069 } else if (mask & (MAY_ACCESS | MAY_CHDIR)) {
1070 if (mask & MAY_NOT_BLOCK)
1071 return -ECHILD;
1072
1073 err = fuse_access(inode, mask);
1074 } else if ((mask & MAY_EXEC) && S_ISREG(inode->i_mode)) {
1075 if (!(inode->i_mode & S_IXUGO)) {
1076 if (refreshed)
1077 return -EACCES;
1078
1079 err = fuse_perm_getattr(inode, mask);
1080 if (!err && !(inode->i_mode & S_IXUGO))
1081 return -EACCES;
1082 }
1083 }
1084 return err;
1085 }
1086
1087 static int parse_dirfile(char *buf, size_t nbytes, struct file *file,
1088 void *dstbuf, filldir_t filldir)
1089 {
1090 while (nbytes >= FUSE_NAME_OFFSET) {
1091 struct fuse_dirent *dirent = (struct fuse_dirent *) buf;
1092 size_t reclen = FUSE_DIRENT_SIZE(dirent);
1093 int over;
1094 if (!dirent->namelen || dirent->namelen > FUSE_NAME_MAX)
1095 return -EIO;
1096 if (reclen > nbytes)
1097 break;
1098
1099 over = filldir(dstbuf, dirent->name, dirent->namelen,
1100 file->f_pos, dirent->ino, dirent->type);
1101 if (over)
1102 break;
1103
1104 buf += reclen;
1105 nbytes -= reclen;
1106 file->f_pos = dirent->off;
1107 }
1108
1109 return 0;
1110 }
1111
1112 static int fuse_readdir(struct file *file, void *dstbuf, filldir_t filldir)
1113 {
1114 int err;
1115 size_t nbytes;
1116 struct page *page;
1117 struct inode *inode = file->f_path.dentry->d_inode;
1118 struct fuse_conn *fc = get_fuse_conn(inode);
1119 struct fuse_req *req;
1120
1121 if (is_bad_inode(inode))
1122 return -EIO;
1123
1124 req = fuse_get_req(fc);
1125 if (IS_ERR(req))
1126 return PTR_ERR(req);
1127
1128 page = alloc_page(GFP_KERNEL);
1129 if (!page) {
1130 fuse_put_request(fc, req);
1131 return -ENOMEM;
1132 }
1133 req->out.argpages = 1;
1134 req->num_pages = 1;
1135 req->pages[0] = page;
1136 fuse_read_fill(req, file, file->f_pos, PAGE_SIZE, FUSE_READDIR);
1137 fuse_request_send(fc, req);
1138 nbytes = req->out.args[0].size;
1139 err = req->out.h.error;
1140 fuse_put_request(fc, req);
1141 if (!err)
1142 err = parse_dirfile(page_address(page), nbytes, file, dstbuf,
1143 filldir);
1144
1145 __free_page(page);
1146 fuse_invalidate_attr(inode); /* atime changed */
1147 return err;
1148 }
1149
1150 static char *read_link(struct dentry *dentry)
1151 {
1152 struct inode *inode = dentry->d_inode;
1153 struct fuse_conn *fc = get_fuse_conn(inode);
1154 struct fuse_req *req = fuse_get_req(fc);
1155 char *link;
1156
1157 if (IS_ERR(req))
1158 return ERR_CAST(req);
1159
1160 link = (char *) __get_free_page(GFP_KERNEL);
1161 if (!link) {
1162 link = ERR_PTR(-ENOMEM);
1163 goto out;
1164 }
1165 req->in.h.opcode = FUSE_READLINK;
1166 req->in.h.nodeid = get_node_id(inode);
1167 req->out.argvar = 1;
1168 req->out.numargs = 1;
1169 req->out.args[0].size = PAGE_SIZE - 1;
1170 req->out.args[0].value = link;
1171 fuse_request_send(fc, req);
1172 if (req->out.h.error) {
1173 free_page((unsigned long) link);
1174 link = ERR_PTR(req->out.h.error);
1175 } else
1176 link[req->out.args[0].size] = '\0';
1177 out:
1178 fuse_put_request(fc, req);
1179 fuse_invalidate_attr(inode); /* atime changed */
1180 return link;
1181 }
1182
1183 static void free_link(char *link)
1184 {
1185 if (!IS_ERR(link))
1186 free_page((unsigned long) link);
1187 }
1188
1189 static void *fuse_follow_link(struct dentry *dentry, struct nameidata *nd)
1190 {
1191 nd_set_link(nd, read_link(dentry));
1192 return NULL;
1193 }
1194
1195 static void fuse_put_link(struct dentry *dentry, struct nameidata *nd, void *c)
1196 {
1197 free_link(nd_get_link(nd));
1198 }
1199
1200 static int fuse_dir_open(struct inode *inode, struct file *file)
1201 {
1202 return fuse_open_common(inode, file, true);
1203 }
1204
1205 static int fuse_dir_release(struct inode *inode, struct file *file)
1206 {
1207 fuse_release_common(file, FUSE_RELEASEDIR);
1208
1209 return 0;
1210 }
1211
1212 static int fuse_dir_fsync(struct file *file, loff_t start, loff_t end,
1213 int datasync)
1214 {
1215 return fuse_fsync_common(file, start, end, datasync, 1);
1216 }
1217
1218 static long fuse_dir_ioctl(struct file *file, unsigned int cmd,
1219 unsigned long arg)
1220 {
1221 struct fuse_conn *fc = get_fuse_conn(file->f_mapping->host);
1222
1223 /* FUSE_IOCTL_DIR only supported for API version >= 7.18 */
1224 if (fc->minor < 18)
1225 return -ENOTTY;
1226
1227 return fuse_ioctl_common(file, cmd, arg, FUSE_IOCTL_DIR);
1228 }
1229
1230 static long fuse_dir_compat_ioctl(struct file *file, unsigned int cmd,
1231 unsigned long arg)
1232 {
1233 struct fuse_conn *fc = get_fuse_conn(file->f_mapping->host);
1234
1235 if (fc->minor < 18)
1236 return -ENOTTY;
1237
1238 return fuse_ioctl_common(file, cmd, arg,
1239 FUSE_IOCTL_COMPAT | FUSE_IOCTL_DIR);
1240 }
1241
1242 static bool update_mtime(unsigned ivalid)
1243 {
1244 /* Always update if mtime is explicitly set */
1245 if (ivalid & ATTR_MTIME_SET)
1246 return true;
1247
1248 /* If it's an open(O_TRUNC) or an ftruncate(), don't update */
1249 if ((ivalid & ATTR_SIZE) && (ivalid & (ATTR_OPEN | ATTR_FILE)))
1250 return false;
1251
1252 /* In all other cases update */
1253 return true;
1254 }
1255
1256 static void iattr_to_fattr(struct iattr *iattr, struct fuse_setattr_in *arg)
1257 {
1258 unsigned ivalid = iattr->ia_valid;
1259
1260 if (ivalid & ATTR_MODE)
1261 arg->valid |= FATTR_MODE, arg->mode = iattr->ia_mode;
1262 if (ivalid & ATTR_UID)
1263 arg->valid |= FATTR_UID, arg->uid = iattr->ia_uid;
1264 if (ivalid & ATTR_GID)
1265 arg->valid |= FATTR_GID, arg->gid = iattr->ia_gid;
1266 if (ivalid & ATTR_SIZE)
1267 arg->valid |= FATTR_SIZE, arg->size = iattr->ia_size;
1268 if (ivalid & ATTR_ATIME) {
1269 arg->valid |= FATTR_ATIME;
1270 arg->atime = iattr->ia_atime.tv_sec;
1271 arg->atimensec = iattr->ia_atime.tv_nsec;
1272 if (!(ivalid & ATTR_ATIME_SET))
1273 arg->valid |= FATTR_ATIME_NOW;
1274 }
1275 if ((ivalid & ATTR_MTIME) && update_mtime(ivalid)) {
1276 arg->valid |= FATTR_MTIME;
1277 arg->mtime = iattr->ia_mtime.tv_sec;
1278 arg->mtimensec = iattr->ia_mtime.tv_nsec;
1279 if (!(ivalid & ATTR_MTIME_SET))
1280 arg->valid |= FATTR_MTIME_NOW;
1281 }
1282 }
1283
1284 /*
1285 * Prevent concurrent writepages on inode
1286 *
1287 * This is done by adding a negative bias to the inode write counter
1288 * and waiting for all pending writes to finish.
1289 */
1290 void fuse_set_nowrite(struct inode *inode)
1291 {
1292 struct fuse_conn *fc = get_fuse_conn(inode);
1293 struct fuse_inode *fi = get_fuse_inode(inode);
1294
1295 BUG_ON(!mutex_is_locked(&inode->i_mutex));
1296
1297 spin_lock(&fc->lock);
1298 BUG_ON(fi->writectr < 0);
1299 fi->writectr += FUSE_NOWRITE;
1300 spin_unlock(&fc->lock);
1301 wait_event(fi->page_waitq, fi->writectr == FUSE_NOWRITE);
1302 }
1303
1304 /*
1305 * Allow writepages on inode
1306 *
1307 * Remove the bias from the writecounter and send any queued
1308 * writepages.
1309 */
1310 static void __fuse_release_nowrite(struct inode *inode)
1311 {
1312 struct fuse_inode *fi = get_fuse_inode(inode);
1313
1314 BUG_ON(fi->writectr != FUSE_NOWRITE);
1315 fi->writectr = 0;
1316 fuse_flush_writepages(inode);
1317 }
1318
1319 void fuse_release_nowrite(struct inode *inode)
1320 {
1321 struct fuse_conn *fc = get_fuse_conn(inode);
1322
1323 spin_lock(&fc->lock);
1324 __fuse_release_nowrite(inode);
1325 spin_unlock(&fc->lock);
1326 }
1327
1328 /*
1329 * Set attributes, and at the same time refresh them.
1330 *
1331 * Truncation is slightly complicated, because the 'truncate' request
1332 * may fail, in which case we don't want to touch the mapping.
1333 * vmtruncate() doesn't allow for this case, so do the rlimit checking
1334 * and the actual truncation by hand.
1335 */
1336 static int fuse_do_setattr(struct dentry *entry, struct iattr *attr,
1337 struct file *file)
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_setattr_in inarg;
1343 struct fuse_attr_out outarg;
1344 bool is_truncate = false;
1345 loff_t oldsize;
1346 int err;
1347
1348 if (!fuse_allow_task(fc, current))
1349 return -EACCES;
1350
1351 if (!(fc->flags & FUSE_DEFAULT_PERMISSIONS))
1352 attr->ia_valid |= ATTR_FORCE;
1353
1354 err = inode_change_ok(inode, attr);
1355 if (err)
1356 return err;
1357
1358 if (attr->ia_valid & ATTR_OPEN) {
1359 if (fc->atomic_o_trunc)
1360 return 0;
1361 file = NULL;
1362 }
1363
1364 if (attr->ia_valid & ATTR_SIZE)
1365 is_truncate = true;
1366
1367 req = fuse_get_req(fc);
1368 if (IS_ERR(req))
1369 return PTR_ERR(req);
1370
1371 if (is_truncate)
1372 fuse_set_nowrite(inode);
1373
1374 memset(&inarg, 0, sizeof(inarg));
1375 memset(&outarg, 0, sizeof(outarg));
1376 iattr_to_fattr(attr, &inarg);
1377 if (file) {
1378 struct fuse_file *ff = file->private_data;
1379 inarg.valid |= FATTR_FH;
1380 inarg.fh = ff->fh;
1381 }
1382 if (attr->ia_valid & ATTR_SIZE) {
1383 /* For mandatory locking in truncate */
1384 inarg.valid |= FATTR_LOCKOWNER;
1385 inarg.lock_owner = fuse_lock_owner_id(fc, current->files);
1386 }
1387 req->in.h.opcode = FUSE_SETATTR;
1388 req->in.h.nodeid = get_node_id(inode);
1389 req->in.numargs = 1;
1390 req->in.args[0].size = sizeof(inarg);
1391 req->in.args[0].value = &inarg;
1392 req->out.numargs = 1;
1393 if (fc->minor < 9)
1394 req->out.args[0].size = FUSE_COMPAT_ATTR_OUT_SIZE;
1395 else
1396 req->out.args[0].size = sizeof(outarg);
1397 req->out.args[0].value = &outarg;
1398 fuse_request_send(fc, req);
1399 err = req->out.h.error;
1400 fuse_put_request(fc, req);
1401 if (err) {
1402 if (err == -EINTR)
1403 fuse_invalidate_attr(inode);
1404 goto error;
1405 }
1406
1407 if ((inode->i_mode ^ outarg.attr.mode) & S_IFMT) {
1408 make_bad_inode(inode);
1409 err = -EIO;
1410 goto error;
1411 }
1412
1413 spin_lock(&fc->lock);
1414 fuse_change_attributes_common(inode, &outarg.attr,
1415 attr_timeout(&outarg));
1416 oldsize = inode->i_size;
1417 i_size_write(inode, outarg.attr.size);
1418
1419 if (is_truncate) {
1420 /* NOTE: this may release/reacquire fc->lock */
1421 __fuse_release_nowrite(inode);
1422 }
1423 spin_unlock(&fc->lock);
1424
1425 /*
1426 * Only call invalidate_inode_pages2() after removing
1427 * FUSE_NOWRITE, otherwise fuse_launder_page() would deadlock.
1428 */
1429 if (S_ISREG(inode->i_mode) && oldsize != outarg.attr.size) {
1430 truncate_pagecache(inode, oldsize, outarg.attr.size);
1431 invalidate_inode_pages2(inode->i_mapping);
1432 }
1433
1434 return 0;
1435
1436 error:
1437 if (is_truncate)
1438 fuse_release_nowrite(inode);
1439
1440 return err;
1441 }
1442
1443 static int fuse_setattr(struct dentry *entry, struct iattr *attr)
1444 {
1445 if (attr->ia_valid & ATTR_FILE)
1446 return fuse_do_setattr(entry, attr, attr->ia_file);
1447 else
1448 return fuse_do_setattr(entry, attr, NULL);
1449 }
1450
1451 static int fuse_getattr(struct vfsmount *mnt, struct dentry *entry,
1452 struct kstat *stat)
1453 {
1454 struct inode *inode = entry->d_inode;
1455 struct fuse_conn *fc = get_fuse_conn(inode);
1456
1457 if (!fuse_allow_task(fc, current))
1458 return -EACCES;
1459
1460 return fuse_update_attributes(inode, stat, NULL, NULL);
1461 }
1462
1463 static int fuse_setxattr(struct dentry *entry, const char *name,
1464 const void *value, size_t size, int flags)
1465 {
1466 struct inode *inode = entry->d_inode;
1467 struct fuse_conn *fc = get_fuse_conn(inode);
1468 struct fuse_req *req;
1469 struct fuse_setxattr_in inarg;
1470 int err;
1471
1472 if (fc->no_setxattr)
1473 return -EOPNOTSUPP;
1474
1475 req = fuse_get_req(fc);
1476 if (IS_ERR(req))
1477 return PTR_ERR(req);
1478
1479 memset(&inarg, 0, sizeof(inarg));
1480 inarg.size = size;
1481 inarg.flags = flags;
1482 req->in.h.opcode = FUSE_SETXATTR;
1483 req->in.h.nodeid = get_node_id(inode);
1484 req->in.numargs = 3;
1485 req->in.args[0].size = sizeof(inarg);
1486 req->in.args[0].value = &inarg;
1487 req->in.args[1].size = strlen(name) + 1;
1488 req->in.args[1].value = name;
1489 req->in.args[2].size = size;
1490 req->in.args[2].value = value;
1491 fuse_request_send(fc, req);
1492 err = req->out.h.error;
1493 fuse_put_request(fc, req);
1494 if (err == -ENOSYS) {
1495 fc->no_setxattr = 1;
1496 err = -EOPNOTSUPP;
1497 }
1498 return err;
1499 }
1500
1501 static ssize_t fuse_getxattr(struct dentry *entry, const char *name,
1502 void *value, size_t size)
1503 {
1504 struct inode *inode = entry->d_inode;
1505 struct fuse_conn *fc = get_fuse_conn(inode);
1506 struct fuse_req *req;
1507 struct fuse_getxattr_in inarg;
1508 struct fuse_getxattr_out outarg;
1509 ssize_t ret;
1510
1511 if (fc->no_getxattr)
1512 return -EOPNOTSUPP;
1513
1514 req = fuse_get_req(fc);
1515 if (IS_ERR(req))
1516 return PTR_ERR(req);
1517
1518 memset(&inarg, 0, sizeof(inarg));
1519 inarg.size = size;
1520 req->in.h.opcode = FUSE_GETXATTR;
1521 req->in.h.nodeid = get_node_id(inode);
1522 req->in.numargs = 2;
1523 req->in.args[0].size = sizeof(inarg);
1524 req->in.args[0].value = &inarg;
1525 req->in.args[1].size = strlen(name) + 1;
1526 req->in.args[1].value = name;
1527 /* This is really two different operations rolled into one */
1528 req->out.numargs = 1;
1529 if (size) {
1530 req->out.argvar = 1;
1531 req->out.args[0].size = size;
1532 req->out.args[0].value = value;
1533 } else {
1534 req->out.args[0].size = sizeof(outarg);
1535 req->out.args[0].value = &outarg;
1536 }
1537 fuse_request_send(fc, req);
1538 ret = req->out.h.error;
1539 if (!ret)
1540 ret = size ? req->out.args[0].size : outarg.size;
1541 else {
1542 if (ret == -ENOSYS) {
1543 fc->no_getxattr = 1;
1544 ret = -EOPNOTSUPP;
1545 }
1546 }
1547 fuse_put_request(fc, req);
1548 return ret;
1549 }
1550
1551 static ssize_t fuse_listxattr(struct dentry *entry, char *list, size_t size)
1552 {
1553 struct inode *inode = entry->d_inode;
1554 struct fuse_conn *fc = get_fuse_conn(inode);
1555 struct fuse_req *req;
1556 struct fuse_getxattr_in inarg;
1557 struct fuse_getxattr_out outarg;
1558 ssize_t ret;
1559
1560 if (!fuse_allow_task(fc, current))
1561 return -EACCES;
1562
1563 if (fc->no_listxattr)
1564 return -EOPNOTSUPP;
1565
1566 req = fuse_get_req(fc);
1567 if (IS_ERR(req))
1568 return PTR_ERR(req);
1569
1570 memset(&inarg, 0, sizeof(inarg));
1571 inarg.size = size;
1572 req->in.h.opcode = FUSE_LISTXATTR;
1573 req->in.h.nodeid = get_node_id(inode);
1574 req->in.numargs = 1;
1575 req->in.args[0].size = sizeof(inarg);
1576 req->in.args[0].value = &inarg;
1577 /* This is really two different operations rolled into one */
1578 req->out.numargs = 1;
1579 if (size) {
1580 req->out.argvar = 1;
1581 req->out.args[0].size = size;
1582 req->out.args[0].value = list;
1583 } else {
1584 req->out.args[0].size = sizeof(outarg);
1585 req->out.args[0].value = &outarg;
1586 }
1587 fuse_request_send(fc, req);
1588 ret = req->out.h.error;
1589 if (!ret)
1590 ret = size ? req->out.args[0].size : outarg.size;
1591 else {
1592 if (ret == -ENOSYS) {
1593 fc->no_listxattr = 1;
1594 ret = -EOPNOTSUPP;
1595 }
1596 }
1597 fuse_put_request(fc, req);
1598 return ret;
1599 }
1600
1601 static int fuse_removexattr(struct dentry *entry, const char *name)
1602 {
1603 struct inode *inode = entry->d_inode;
1604 struct fuse_conn *fc = get_fuse_conn(inode);
1605 struct fuse_req *req;
1606 int err;
1607
1608 if (fc->no_removexattr)
1609 return -EOPNOTSUPP;
1610
1611 req = fuse_get_req(fc);
1612 if (IS_ERR(req))
1613 return PTR_ERR(req);
1614
1615 req->in.h.opcode = FUSE_REMOVEXATTR;
1616 req->in.h.nodeid = get_node_id(inode);
1617 req->in.numargs = 1;
1618 req->in.args[0].size = strlen(name) + 1;
1619 req->in.args[0].value = name;
1620 fuse_request_send(fc, req);
1621 err = req->out.h.error;
1622 fuse_put_request(fc, req);
1623 if (err == -ENOSYS) {
1624 fc->no_removexattr = 1;
1625 err = -EOPNOTSUPP;
1626 }
1627 return err;
1628 }
1629
1630 static const struct inode_operations fuse_dir_inode_operations = {
1631 .lookup = fuse_lookup,
1632 .mkdir = fuse_mkdir,
1633 .symlink = fuse_symlink,
1634 .unlink = fuse_unlink,
1635 .rmdir = fuse_rmdir,
1636 .rename = fuse_rename,
1637 .link = fuse_link,
1638 .setattr = fuse_setattr,
1639 .create = fuse_create,
1640 .mknod = fuse_mknod,
1641 .permission = fuse_permission,
1642 .getattr = fuse_getattr,
1643 .setxattr = fuse_setxattr,
1644 .getxattr = fuse_getxattr,
1645 .listxattr = fuse_listxattr,
1646 .removexattr = fuse_removexattr,
1647 };
1648
1649 static const struct file_operations fuse_dir_operations = {
1650 .llseek = generic_file_llseek,
1651 .read = generic_read_dir,
1652 .readdir = fuse_readdir,
1653 .open = fuse_dir_open,
1654 .release = fuse_dir_release,
1655 .fsync = fuse_dir_fsync,
1656 .unlocked_ioctl = fuse_dir_ioctl,
1657 .compat_ioctl = fuse_dir_compat_ioctl,
1658 };
1659
1660 static const struct inode_operations fuse_common_inode_operations = {
1661 .setattr = fuse_setattr,
1662 .permission = fuse_permission,
1663 .getattr = fuse_getattr,
1664 .setxattr = fuse_setxattr,
1665 .getxattr = fuse_getxattr,
1666 .listxattr = fuse_listxattr,
1667 .removexattr = fuse_removexattr,
1668 };
1669
1670 static const struct inode_operations fuse_symlink_inode_operations = {
1671 .setattr = fuse_setattr,
1672 .follow_link = fuse_follow_link,
1673 .put_link = fuse_put_link,
1674 .readlink = generic_readlink,
1675 .getattr = fuse_getattr,
1676 .setxattr = fuse_setxattr,
1677 .getxattr = fuse_getxattr,
1678 .listxattr = fuse_listxattr,
1679 .removexattr = fuse_removexattr,
1680 };
1681
1682 void fuse_init_common(struct inode *inode)
1683 {
1684 inode->i_op = &fuse_common_inode_operations;
1685 }
1686
1687 void fuse_init_dir(struct inode *inode)
1688 {
1689 inode->i_op = &fuse_dir_inode_operations;
1690 inode->i_fop = &fuse_dir_operations;
1691 }
1692
1693 void fuse_init_symlink(struct inode *inode)
1694 {
1695 inode->i_op = &fuse_symlink_inode_operations;
1696 }
Linux kernel - Deliverables
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