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1/*
2 FUSE: Filesystem in Userspace
3 Copyright (C) 2001-2008 Miklos Szeredi <miklos@szeredi.hu>
4
5 This program can be distributed under the terms of the GNU GPL.
6 See the file COPYING.
7*/
8
9#include "fuse_i.h"
10
11#include <linux/pagemap.h>
12#include <linux/file.h>
13#include <linux/sched.h>
14#include <linux/namei.h>
15#include <linux/slab.h>
16
17#if BITS_PER_LONG >= 64
18static inline void fuse_dentry_settime(struct dentry *entry, u64 time)
19{
20 entry->d_time = time;
21}
22
23static 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 */
31static 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
37static 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 */
53static 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 */
66static 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
73static u64 attr_timeout(struct fuse_attr_out *o)
74{
75 return time_to_jiffies(o->attr_valid, o->attr_valid_nsec);
76}
77
78static 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 */
87void 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 */
100void 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 */
109static void fuse_invalidate_entry(struct dentry *entry)
110{
111 d_invalidate(entry);
112 fuse_invalidate_entry_cache(entry);
113}
114
115static 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
133u64 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 */
157static 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
225static int invalid_nodeid(u64 nodeid)
226{
227 return !nodeid || nodeid == FUSE_ROOT_ID;
228}
229
230const struct dentry_operations fuse_dentry_operations = {
231 .d_revalidate = fuse_dentry_revalidate,
232};
233
234int 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 */
244static 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
260int 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
318static 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 */
372static 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 */
478static 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
547static 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
573static 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
585static 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
608static 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
626static 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
658static 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
683static 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
735static 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
775static void fuse_fillattr(struct inode *inode, struct fuse_attr *attr,
776 struct kstat *stat)
777{
778 unsigned int blkbits;
779
780 stat->dev = inode->i_sb->s_dev;
781 stat->ino = attr->ino;
782 stat->mode = (inode->i_mode & S_IFMT) | (attr->mode & 07777);
783 stat->nlink = attr->nlink;
784 stat->uid = attr->uid;
785 stat->gid = attr->gid;
786 stat->rdev = inode->i_rdev;
787 stat->atime.tv_sec = attr->atime;
788 stat->atime.tv_nsec = attr->atimensec;
789 stat->mtime.tv_sec = attr->mtime;
790 stat->mtime.tv_nsec = attr->mtimensec;
791 stat->ctime.tv_sec = attr->ctime;
792 stat->ctime.tv_nsec = attr->ctimensec;
793 stat->size = attr->size;
794 stat->blocks = attr->blocks;
795
796 if (attr->blksize != 0)
797 blkbits = ilog2(attr->blksize);
798 else
799 blkbits = inode->i_sb->s_blocksize_bits;
800
801 stat->blksize = 1 << blkbits;
802}
803
804static int fuse_do_getattr(struct inode *inode, struct kstat *stat,
805 struct file *file)
806{
807 int err;
808 struct fuse_getattr_in inarg;
809 struct fuse_attr_out outarg;
810 struct fuse_conn *fc = get_fuse_conn(inode);
811 struct fuse_req *req;
812 u64 attr_version;
813
814 req = fuse_get_req(fc);
815 if (IS_ERR(req))
816 return PTR_ERR(req);
817
818 attr_version = fuse_get_attr_version(fc);
819
820 memset(&inarg, 0, sizeof(inarg));
821 memset(&outarg, 0, sizeof(outarg));
822 /* Directories have separate file-handle space */
823 if (file && S_ISREG(inode->i_mode)) {
824 struct fuse_file *ff = file->private_data;
825
826 inarg.getattr_flags |= FUSE_GETATTR_FH;
827 inarg.fh = ff->fh;
828 }
829 req->in.h.opcode = FUSE_GETATTR;
830 req->in.h.nodeid = get_node_id(inode);
831 req->in.numargs = 1;
832 req->in.args[0].size = sizeof(inarg);
833 req->in.args[0].value = &inarg;
834 req->out.numargs = 1;
835 if (fc->minor < 9)
836 req->out.args[0].size = FUSE_COMPAT_ATTR_OUT_SIZE;
837 else
838 req->out.args[0].size = sizeof(outarg);
839 req->out.args[0].value = &outarg;
840 fuse_request_send(fc, req);
841 err = req->out.h.error;
842 fuse_put_request(fc, req);
843 if (!err) {
844 if ((inode->i_mode ^ outarg.attr.mode) & S_IFMT) {
845 make_bad_inode(inode);
846 err = -EIO;
847 } else {
848 fuse_change_attributes(inode, &outarg.attr,
849 attr_timeout(&outarg),
850 attr_version);
851 if (stat)
852 fuse_fillattr(inode, &outarg.attr, stat);
853 }
854 }
855 return err;
856}
857
858int fuse_update_attributes(struct inode *inode, struct kstat *stat,
859 struct file *file, bool *refreshed)
860{
861 struct fuse_inode *fi = get_fuse_inode(inode);
862 int err;
863 bool r;
864
865 if (fi->i_time < get_jiffies_64()) {
866 r = true;
867 err = fuse_do_getattr(inode, stat, file);
868 } else {
869 r = false;
870 err = 0;
871 if (stat) {
872 generic_fillattr(inode, stat);
873 stat->mode = fi->orig_i_mode;
874 stat->ino = fi->orig_ino;
875 }
876 }
877
878 if (refreshed != NULL)
879 *refreshed = r;
880
881 return err;
882}
883
884int fuse_reverse_inval_entry(struct super_block *sb, u64 parent_nodeid,
885 u64 child_nodeid, struct qstr *name)
886{
887 int err = -ENOTDIR;
888 struct inode *parent;
889 struct dentry *dir;
890 struct dentry *entry;
891
892 parent = ilookup5(sb, parent_nodeid, fuse_inode_eq, &parent_nodeid);
893 if (!parent)
894 return -ENOENT;
895
896 mutex_lock(&parent->i_mutex);
897 if (!S_ISDIR(parent->i_mode))
898 goto unlock;
899
900 err = -ENOENT;
901 dir = d_find_alias(parent);
902 if (!dir)
903 goto unlock;
904
905 entry = d_lookup(dir, name);
906 dput(dir);
907 if (!entry)
908 goto unlock;
909
910 fuse_invalidate_attr(parent);
911 fuse_invalidate_entry(entry);
912
913 if (child_nodeid != 0 && entry->d_inode) {
914 mutex_lock(&entry->d_inode->i_mutex);
915 if (get_node_id(entry->d_inode) != child_nodeid) {
916 err = -ENOENT;
917 goto badentry;
918 }
919 if (d_mountpoint(entry)) {
920 err = -EBUSY;
921 goto badentry;
922 }
923 if (S_ISDIR(entry->d_inode->i_mode)) {
924 shrink_dcache_parent(entry);
925 if (!simple_empty(entry)) {
926 err = -ENOTEMPTY;
927 goto badentry;
928 }
929 entry->d_inode->i_flags |= S_DEAD;
930 }
931 dont_mount(entry);
932 clear_nlink(entry->d_inode);
933 err = 0;
934 badentry:
935 mutex_unlock(&entry->d_inode->i_mutex);
936 if (!err)
937 d_delete(entry);
938 } else {
939 err = 0;
940 }
941 dput(entry);
942
943 unlock:
944 mutex_unlock(&parent->i_mutex);
945 iput(parent);
946 return err;
947}
948
949/*
950 * Calling into a user-controlled filesystem gives the filesystem
951 * daemon ptrace-like capabilities over the requester process. This
952 * means, that the filesystem daemon is able to record the exact
953 * filesystem operations performed, and can also control the behavior
954 * of the requester process in otherwise impossible ways. For example
955 * it can delay the operation for arbitrary length of time allowing
956 * DoS against the requester.
957 *
958 * For this reason only those processes can call into the filesystem,
959 * for which the owner of the mount has ptrace privilege. This
960 * excludes processes started by other users, suid or sgid processes.
961 */
962int fuse_allow_task(struct fuse_conn *fc, struct task_struct *task)
963{
964 const struct cred *cred;
965 int ret;
966
967 if (fc->flags & FUSE_ALLOW_OTHER)
968 return 1;
969
970 rcu_read_lock();
971 ret = 0;
972 cred = __task_cred(task);
973 if (cred->euid == fc->user_id &&
974 cred->suid == fc->user_id &&
975 cred->uid == fc->user_id &&
976 cred->egid == fc->group_id &&
977 cred->sgid == fc->group_id &&
978 cred->gid == fc->group_id)
979 ret = 1;
980 rcu_read_unlock();
981
982 return ret;
983}
984
985static int fuse_access(struct inode *inode, int mask)
986{
987 struct fuse_conn *fc = get_fuse_conn(inode);
988 struct fuse_req *req;
989 struct fuse_access_in inarg;
990 int err;
991
992 if (fc->no_access)
993 return 0;
994
995 req = fuse_get_req(fc);
996 if (IS_ERR(req))
997 return PTR_ERR(req);
998
999 memset(&inarg, 0, sizeof(inarg));
1000 inarg.mask = mask & (MAY_READ | MAY_WRITE | MAY_EXEC);
1001 req->in.h.opcode = FUSE_ACCESS;
1002 req->in.h.nodeid = get_node_id(inode);
1003 req->in.numargs = 1;
1004 req->in.args[0].size = sizeof(inarg);
1005 req->in.args[0].value = &inarg;
1006 fuse_request_send(fc, req);
1007 err = req->out.h.error;
1008 fuse_put_request(fc, req);
1009 if (err == -ENOSYS) {
1010 fc->no_access = 1;
1011 err = 0;
1012 }
1013 return err;
1014}
1015
1016static int fuse_perm_getattr(struct inode *inode, int mask)
1017{
1018 if (mask & MAY_NOT_BLOCK)
1019 return -ECHILD;
1020
1021 return fuse_do_getattr(inode, NULL, NULL);
1022}
1023
1024/*
1025 * Check permission. The two basic access models of FUSE are:
1026 *
1027 * 1) Local access checking ('default_permissions' mount option) based
1028 * on file mode. This is the plain old disk filesystem permission
1029 * modell.
1030 *
1031 * 2) "Remote" access checking, where server is responsible for
1032 * checking permission in each inode operation. An exception to this
1033 * is if ->permission() was invoked from sys_access() in which case an
1034 * access request is sent. Execute permission is still checked
1035 * locally based on file mode.
1036 */
1037static int fuse_permission(struct inode *inode, int mask)
1038{
1039 struct fuse_conn *fc = get_fuse_conn(inode);
1040 bool refreshed = false;
1041 int err = 0;
1042
1043 if (!fuse_allow_task(fc, current))
1044 return -EACCES;
1045
1046 /*
1047 * If attributes are needed, refresh them before proceeding
1048 */
1049 if ((fc->flags & FUSE_DEFAULT_PERMISSIONS) ||
1050 ((mask & MAY_EXEC) && S_ISREG(inode->i_mode))) {
1051 struct fuse_inode *fi = get_fuse_inode(inode);
1052
1053 if (fi->i_time < get_jiffies_64()) {
1054 refreshed = true;
1055
1056 err = fuse_perm_getattr(inode, mask);
1057 if (err)
1058 return err;
1059 }
1060 }
1061
1062 if (fc->flags & FUSE_DEFAULT_PERMISSIONS) {
1063 err = generic_permission(inode, mask);
1064
1065 /* If permission is denied, try to refresh file
1066 attributes. This is also needed, because the root
1067 node will at first have no permissions */
1068 if (err == -EACCES && !refreshed) {
1069 err = fuse_perm_getattr(inode, mask);
1070 if (!err)
1071 err = generic_permission(inode, mask);
1072 }
1073
1074 /* Note: the opposite of the above test does not
1075 exist. So if permissions are revoked this won't be
1076 noticed immediately, only after the attribute
1077 timeout has expired */
1078 } else if (mask & (MAY_ACCESS | MAY_CHDIR)) {
1079 if (mask & MAY_NOT_BLOCK)
1080 return -ECHILD;
1081
1082 err = fuse_access(inode, mask);
1083 } else if ((mask & MAY_EXEC) && S_ISREG(inode->i_mode)) {
1084 if (!(inode->i_mode & S_IXUGO)) {
1085 if (refreshed)
1086 return -EACCES;
1087
1088 err = fuse_perm_getattr(inode, mask);
1089 if (!err && !(inode->i_mode & S_IXUGO))
1090 return -EACCES;
1091 }
1092 }
1093 return err;
1094}
1095
1096static int parse_dirfile(char *buf, size_t nbytes, struct file *file,
1097 void *dstbuf, filldir_t filldir)
1098{
1099 while (nbytes >= FUSE_NAME_OFFSET) {
1100 struct fuse_dirent *dirent = (struct fuse_dirent *) buf;
1101 size_t reclen = FUSE_DIRENT_SIZE(dirent);
1102 int over;
1103 if (!dirent->namelen || dirent->namelen > FUSE_NAME_MAX)
1104 return -EIO;
1105 if (reclen > nbytes)
1106 break;
1107
1108 over = filldir(dstbuf, dirent->name, dirent->namelen,
1109 file->f_pos, dirent->ino, dirent->type);
1110 if (over)
1111 break;
1112
1113 buf += reclen;
1114 nbytes -= reclen;
1115 file->f_pos = dirent->off;
1116 }
1117
1118 return 0;
1119}
1120
1121static int fuse_readdir(struct file *file, void *dstbuf, filldir_t filldir)
1122{
1123 int err;
1124 size_t nbytes;
1125 struct page *page;
1126 struct inode *inode = file->f_path.dentry->d_inode;
1127 struct fuse_conn *fc = get_fuse_conn(inode);
1128 struct fuse_req *req;
1129
1130 if (is_bad_inode(inode))
1131 return -EIO;
1132
1133 req = fuse_get_req(fc);
1134 if (IS_ERR(req))
1135 return PTR_ERR(req);
1136
1137 page = alloc_page(GFP_KERNEL);
1138 if (!page) {
1139 fuse_put_request(fc, req);
1140 return -ENOMEM;
1141 }
1142 req->out.argpages = 1;
1143 req->num_pages = 1;
1144 req->pages[0] = page;
1145 fuse_read_fill(req, file, file->f_pos, PAGE_SIZE, FUSE_READDIR);
1146 fuse_request_send(fc, req);
1147 nbytes = req->out.args[0].size;
1148 err = req->out.h.error;
1149 fuse_put_request(fc, req);
1150 if (!err)
1151 err = parse_dirfile(page_address(page), nbytes, file, dstbuf,
1152 filldir);
1153
1154 __free_page(page);
1155 fuse_invalidate_attr(inode); /* atime changed */
1156 return err;
1157}
1158
1159static char *read_link(struct dentry *dentry)
1160{
1161 struct inode *inode = dentry->d_inode;
1162 struct fuse_conn *fc = get_fuse_conn(inode);
1163 struct fuse_req *req = fuse_get_req(fc);
1164 char *link;
1165
1166 if (IS_ERR(req))
1167 return ERR_CAST(req);
1168
1169 link = (char *) __get_free_page(GFP_KERNEL);
1170 if (!link) {
1171 link = ERR_PTR(-ENOMEM);
1172 goto out;
1173 }
1174 req->in.h.opcode = FUSE_READLINK;
1175 req->in.h.nodeid = get_node_id(inode);
1176 req->out.argvar = 1;
1177 req->out.numargs = 1;
1178 req->out.args[0].size = PAGE_SIZE - 1;
1179 req->out.args[0].value = link;
1180 fuse_request_send(fc, req);
1181 if (req->out.h.error) {
1182 free_page((unsigned long) link);
1183 link = ERR_PTR(req->out.h.error);
1184 } else
1185 link[req->out.args[0].size] = '\0';
1186 out:
1187 fuse_put_request(fc, req);
1188 fuse_invalidate_attr(inode); /* atime changed */
1189 return link;
1190}
1191
1192static void free_link(char *link)
1193{
1194 if (!IS_ERR(link))
1195 free_page((unsigned long) link);
1196}
1197
1198static void *fuse_follow_link(struct dentry *dentry, struct nameidata *nd)
1199{
1200 nd_set_link(nd, read_link(dentry));
1201 return NULL;
1202}
1203
1204static void fuse_put_link(struct dentry *dentry, struct nameidata *nd, void *c)
1205{
1206 free_link(nd_get_link(nd));
1207}
1208
1209static int fuse_dir_open(struct inode *inode, struct file *file)
1210{
1211 return fuse_open_common(inode, file, true);
1212}
1213
1214static int fuse_dir_release(struct inode *inode, struct file *file)
1215{
1216 fuse_release_common(file, FUSE_RELEASEDIR);
1217
1218 return 0;
1219}
1220
1221static int fuse_dir_fsync(struct file *file, loff_t start, loff_t end,
1222 int datasync)
1223{
1224 return fuse_fsync_common(file, start, end, datasync, 1);
1225}
1226
1227static long fuse_dir_ioctl(struct file *file, unsigned int cmd,
1228 unsigned long arg)
1229{
1230 struct fuse_conn *fc = get_fuse_conn(file->f_mapping->host);
1231
1232 /* FUSE_IOCTL_DIR only supported for API version >= 7.18 */
1233 if (fc->minor < 18)
1234 return -ENOTTY;
1235
1236 return fuse_ioctl_common(file, cmd, arg, FUSE_IOCTL_DIR);
1237}
1238
1239static long fuse_dir_compat_ioctl(struct file *file, unsigned int cmd,
1240 unsigned long arg)
1241{
1242 struct fuse_conn *fc = get_fuse_conn(file->f_mapping->host);
1243
1244 if (fc->minor < 18)
1245 return -ENOTTY;
1246
1247 return fuse_ioctl_common(file, cmd, arg,
1248 FUSE_IOCTL_COMPAT | FUSE_IOCTL_DIR);
1249}
1250
1251static bool update_mtime(unsigned ivalid)
1252{
1253 /* Always update if mtime is explicitly set */
1254 if (ivalid & ATTR_MTIME_SET)
1255 return true;
1256
1257 /* If it's an open(O_TRUNC) or an ftruncate(), don't update */
1258 if ((ivalid & ATTR_SIZE) && (ivalid & (ATTR_OPEN | ATTR_FILE)))
1259 return false;
1260
1261 /* In all other cases update */
1262 return true;
1263}
1264
1265static void iattr_to_fattr(struct iattr *iattr, struct fuse_setattr_in *arg)
1266{
1267 unsigned ivalid = iattr->ia_valid;
1268
1269 if (ivalid & ATTR_MODE)
1270 arg->valid |= FATTR_MODE, arg->mode = iattr->ia_mode;
1271 if (ivalid & ATTR_UID)
1272 arg->valid |= FATTR_UID, arg->uid = iattr->ia_uid;
1273 if (ivalid & ATTR_GID)
1274 arg->valid |= FATTR_GID, arg->gid = iattr->ia_gid;
1275 if (ivalid & ATTR_SIZE)
1276 arg->valid |= FATTR_SIZE, arg->size = iattr->ia_size;
1277 if (ivalid & ATTR_ATIME) {
1278 arg->valid |= FATTR_ATIME;
1279 arg->atime = iattr->ia_atime.tv_sec;
1280 arg->atimensec = iattr->ia_atime.tv_nsec;
1281 if (!(ivalid & ATTR_ATIME_SET))
1282 arg->valid |= FATTR_ATIME_NOW;
1283 }
1284 if ((ivalid & ATTR_MTIME) && update_mtime(ivalid)) {
1285 arg->valid |= FATTR_MTIME;
1286 arg->mtime = iattr->ia_mtime.tv_sec;
1287 arg->mtimensec = iattr->ia_mtime.tv_nsec;
1288 if (!(ivalid & ATTR_MTIME_SET))
1289 arg->valid |= FATTR_MTIME_NOW;
1290 }
1291}
1292
1293/*
1294 * Prevent concurrent writepages on inode
1295 *
1296 * This is done by adding a negative bias to the inode write counter
1297 * and waiting for all pending writes to finish.
1298 */
1299void fuse_set_nowrite(struct inode *inode)
1300{
1301 struct fuse_conn *fc = get_fuse_conn(inode);
1302 struct fuse_inode *fi = get_fuse_inode(inode);
1303
1304 BUG_ON(!mutex_is_locked(&inode->i_mutex));
1305
1306 spin_lock(&fc->lock);
1307 BUG_ON(fi->writectr < 0);
1308 fi->writectr += FUSE_NOWRITE;
1309 spin_unlock(&fc->lock);
1310 wait_event(fi->page_waitq, fi->writectr == FUSE_NOWRITE);
1311}
1312
1313/*
1314 * Allow writepages on inode
1315 *
1316 * Remove the bias from the writecounter and send any queued
1317 * writepages.
1318 */
1319static void __fuse_release_nowrite(struct inode *inode)
1320{
1321 struct fuse_inode *fi = get_fuse_inode(inode);
1322
1323 BUG_ON(fi->writectr != FUSE_NOWRITE);
1324 fi->writectr = 0;
1325 fuse_flush_writepages(inode);
1326}
1327
1328void fuse_release_nowrite(struct inode *inode)
1329{
1330 struct fuse_conn *fc = get_fuse_conn(inode);
1331
1332 spin_lock(&fc->lock);
1333 __fuse_release_nowrite(inode);
1334 spin_unlock(&fc->lock);
1335}
1336
1337/*
1338 * Set attributes, and at the same time refresh them.
1339 *
1340 * Truncation is slightly complicated, because the 'truncate' request
1341 * may fail, in which case we don't want to touch the mapping.
1342 * vmtruncate() doesn't allow for this case, so do the rlimit checking
1343 * and the actual truncation by hand.
1344 */
1345static int fuse_do_setattr(struct dentry *entry, struct iattr *attr,
1346 struct file *file)
1347{
1348 struct inode *inode = entry->d_inode;
1349 struct fuse_conn *fc = get_fuse_conn(inode);
1350 struct fuse_req *req;
1351 struct fuse_setattr_in inarg;
1352 struct fuse_attr_out outarg;
1353 bool is_truncate = false;
1354 loff_t oldsize;
1355 int err;
1356
1357 if (!fuse_allow_task(fc, current))
1358 return -EACCES;
1359
1360 if (!(fc->flags & FUSE_DEFAULT_PERMISSIONS))
1361 attr->ia_valid |= ATTR_FORCE;
1362
1363 err = inode_change_ok(inode, attr);
1364 if (err)
1365 return err;
1366
1367 if (attr->ia_valid & ATTR_OPEN) {
1368 if (fc->atomic_o_trunc)
1369 return 0;
1370 file = NULL;
1371 }
1372
1373 if (attr->ia_valid & ATTR_SIZE)
1374 is_truncate = true;
1375
1376 req = fuse_get_req(fc);
1377 if (IS_ERR(req))
1378 return PTR_ERR(req);
1379
1380 if (is_truncate)
1381 fuse_set_nowrite(inode);
1382
1383 memset(&inarg, 0, sizeof(inarg));
1384 memset(&outarg, 0, sizeof(outarg));
1385 iattr_to_fattr(attr, &inarg);
1386 if (file) {
1387 struct fuse_file *ff = file->private_data;
1388 inarg.valid |= FATTR_FH;
1389 inarg.fh = ff->fh;
1390 }
1391 if (attr->ia_valid & ATTR_SIZE) {
1392 /* For mandatory locking in truncate */
1393 inarg.valid |= FATTR_LOCKOWNER;
1394 inarg.lock_owner = fuse_lock_owner_id(fc, current->files);
1395 }
1396 req->in.h.opcode = FUSE_SETATTR;
1397 req->in.h.nodeid = get_node_id(inode);
1398 req->in.numargs = 1;
1399 req->in.args[0].size = sizeof(inarg);
1400 req->in.args[0].value = &inarg;
1401 req->out.numargs = 1;
1402 if (fc->minor < 9)
1403 req->out.args[0].size = FUSE_COMPAT_ATTR_OUT_SIZE;
1404 else
1405 req->out.args[0].size = sizeof(outarg);
1406 req->out.args[0].value = &outarg;
1407 fuse_request_send(fc, req);
1408 err = req->out.h.error;
1409 fuse_put_request(fc, req);
1410 if (err) {
1411 if (err == -EINTR)
1412 fuse_invalidate_attr(inode);
1413 goto error;
1414 }
1415
1416 if ((inode->i_mode ^ outarg.attr.mode) & S_IFMT) {
1417 make_bad_inode(inode);
1418 err = -EIO;
1419 goto error;
1420 }
1421
1422 spin_lock(&fc->lock);
1423 fuse_change_attributes_common(inode, &outarg.attr,
1424 attr_timeout(&outarg));
1425 oldsize = inode->i_size;
1426 i_size_write(inode, outarg.attr.size);
1427
1428 if (is_truncate) {
1429 /* NOTE: this may release/reacquire fc->lock */
1430 __fuse_release_nowrite(inode);
1431 }
1432 spin_unlock(&fc->lock);
1433
1434 /*
1435 * Only call invalidate_inode_pages2() after removing
1436 * FUSE_NOWRITE, otherwise fuse_launder_page() would deadlock.
1437 */
1438 if (S_ISREG(inode->i_mode) && oldsize != outarg.attr.size) {
1439 truncate_pagecache(inode, oldsize, outarg.attr.size);
1440 invalidate_inode_pages2(inode->i_mapping);
1441 }
1442
1443 return 0;
1444
1445error:
1446 if (is_truncate)
1447 fuse_release_nowrite(inode);
1448
1449 return err;
1450}
1451
1452static int fuse_setattr(struct dentry *entry, struct iattr *attr)
1453{
1454 if (attr->ia_valid & ATTR_FILE)
1455 return fuse_do_setattr(entry, attr, attr->ia_file);
1456 else
1457 return fuse_do_setattr(entry, attr, NULL);
1458}
1459
1460static int fuse_getattr(struct vfsmount *mnt, struct dentry *entry,
1461 struct kstat *stat)
1462{
1463 struct inode *inode = entry->d_inode;
1464 struct fuse_conn *fc = get_fuse_conn(inode);
1465
1466 if (!fuse_allow_task(fc, current))
1467 return -EACCES;
1468
1469 return fuse_update_attributes(inode, stat, NULL, NULL);
1470}
1471
1472static int fuse_setxattr(struct dentry *entry, const char *name,
1473 const void *value, size_t size, int flags)
1474{
1475 struct inode *inode = entry->d_inode;
1476 struct fuse_conn *fc = get_fuse_conn(inode);
1477 struct fuse_req *req;
1478 struct fuse_setxattr_in inarg;
1479 int err;
1480
1481 if (fc->no_setxattr)
1482 return -EOPNOTSUPP;
1483
1484 req = fuse_get_req(fc);
1485 if (IS_ERR(req))
1486 return PTR_ERR(req);
1487
1488 memset(&inarg, 0, sizeof(inarg));
1489 inarg.size = size;
1490 inarg.flags = flags;
1491 req->in.h.opcode = FUSE_SETXATTR;
1492 req->in.h.nodeid = get_node_id(inode);
1493 req->in.numargs = 3;
1494 req->in.args[0].size = sizeof(inarg);
1495 req->in.args[0].value = &inarg;
1496 req->in.args[1].size = strlen(name) + 1;
1497 req->in.args[1].value = name;
1498 req->in.args[2].size = size;
1499 req->in.args[2].value = value;
1500 fuse_request_send(fc, req);
1501 err = req->out.h.error;
1502 fuse_put_request(fc, req);
1503 if (err == -ENOSYS) {
1504 fc->no_setxattr = 1;
1505 err = -EOPNOTSUPP;
1506 }
1507 return err;
1508}
1509
1510static ssize_t fuse_getxattr(struct dentry *entry, const char *name,
1511 void *value, size_t size)
1512{
1513 struct inode *inode = entry->d_inode;
1514 struct fuse_conn *fc = get_fuse_conn(inode);
1515 struct fuse_req *req;
1516 struct fuse_getxattr_in inarg;
1517 struct fuse_getxattr_out outarg;
1518 ssize_t ret;
1519
1520 if (fc->no_getxattr)
1521 return -EOPNOTSUPP;
1522
1523 req = fuse_get_req(fc);
1524 if (IS_ERR(req))
1525 return PTR_ERR(req);
1526
1527 memset(&inarg, 0, sizeof(inarg));
1528 inarg.size = size;
1529 req->in.h.opcode = FUSE_GETXATTR;
1530 req->in.h.nodeid = get_node_id(inode);
1531 req->in.numargs = 2;
1532 req->in.args[0].size = sizeof(inarg);
1533 req->in.args[0].value = &inarg;
1534 req->in.args[1].size = strlen(name) + 1;
1535 req->in.args[1].value = name;
1536 /* This is really two different operations rolled into one */
1537 req->out.numargs = 1;
1538 if (size) {
1539 req->out.argvar = 1;
1540 req->out.args[0].size = size;
1541 req->out.args[0].value = value;
1542 } else {
1543 req->out.args[0].size = sizeof(outarg);
1544 req->out.args[0].value = &outarg;
1545 }
1546 fuse_request_send(fc, req);
1547 ret = req->out.h.error;
1548 if (!ret)
1549 ret = size ? req->out.args[0].size : outarg.size;
1550 else {
1551 if (ret == -ENOSYS) {
1552 fc->no_getxattr = 1;
1553 ret = -EOPNOTSUPP;
1554 }
1555 }
1556 fuse_put_request(fc, req);
1557 return ret;
1558}
1559
1560static ssize_t fuse_listxattr(struct dentry *entry, char *list, size_t size)
1561{
1562 struct inode *inode = entry->d_inode;
1563 struct fuse_conn *fc = get_fuse_conn(inode);
1564 struct fuse_req *req;
1565 struct fuse_getxattr_in inarg;
1566 struct fuse_getxattr_out outarg;
1567 ssize_t ret;
1568
1569 if (!fuse_allow_task(fc, current))
1570 return -EACCES;
1571
1572 if (fc->no_listxattr)
1573 return -EOPNOTSUPP;
1574
1575 req = fuse_get_req(fc);
1576 if (IS_ERR(req))
1577 return PTR_ERR(req);
1578
1579 memset(&inarg, 0, sizeof(inarg));
1580 inarg.size = size;
1581 req->in.h.opcode = FUSE_LISTXATTR;
1582 req->in.h.nodeid = get_node_id(inode);
1583 req->in.numargs = 1;
1584 req->in.args[0].size = sizeof(inarg);
1585 req->in.args[0].value = &inarg;
1586 /* This is really two different operations rolled into one */
1587 req->out.numargs = 1;
1588 if (size) {
1589 req->out.argvar = 1;
1590 req->out.args[0].size = size;
1591 req->out.args[0].value = list;
1592 } else {
1593 req->out.args[0].size = sizeof(outarg);
1594 req->out.args[0].value = &outarg;
1595 }
1596 fuse_request_send(fc, req);
1597 ret = req->out.h.error;
1598 if (!ret)
1599 ret = size ? req->out.args[0].size : outarg.size;
1600 else {
1601 if (ret == -ENOSYS) {
1602 fc->no_listxattr = 1;
1603 ret = -EOPNOTSUPP;
1604 }
1605 }
1606 fuse_put_request(fc, req);
1607 return ret;
1608}
1609
1610static int fuse_removexattr(struct dentry *entry, const char *name)
1611{
1612 struct inode *inode = entry->d_inode;
1613 struct fuse_conn *fc = get_fuse_conn(inode);
1614 struct fuse_req *req;
1615 int err;
1616
1617 if (fc->no_removexattr)
1618 return -EOPNOTSUPP;
1619
1620 req = fuse_get_req(fc);
1621 if (IS_ERR(req))
1622 return PTR_ERR(req);
1623
1624 req->in.h.opcode = FUSE_REMOVEXATTR;
1625 req->in.h.nodeid = get_node_id(inode);
1626 req->in.numargs = 1;
1627 req->in.args[0].size = strlen(name) + 1;
1628 req->in.args[0].value = name;
1629 fuse_request_send(fc, req);
1630 err = req->out.h.error;
1631 fuse_put_request(fc, req);
1632 if (err == -ENOSYS) {
1633 fc->no_removexattr = 1;
1634 err = -EOPNOTSUPP;
1635 }
1636 return err;
1637}
1638
1639static const struct inode_operations fuse_dir_inode_operations = {
1640 .lookup = fuse_lookup,
1641 .mkdir = fuse_mkdir,
1642 .symlink = fuse_symlink,
1643 .unlink = fuse_unlink,
1644 .rmdir = fuse_rmdir,
1645 .rename = fuse_rename,
1646 .link = fuse_link,
1647 .setattr = fuse_setattr,
1648 .create = fuse_create,
1649 .mknod = fuse_mknod,
1650 .permission = fuse_permission,
1651 .getattr = fuse_getattr,
1652 .setxattr = fuse_setxattr,
1653 .getxattr = fuse_getxattr,
1654 .listxattr = fuse_listxattr,
1655 .removexattr = fuse_removexattr,
1656};
1657
1658static const struct file_operations fuse_dir_operations = {
1659 .llseek = generic_file_llseek,
1660 .read = generic_read_dir,
1661 .readdir = fuse_readdir,
1662 .open = fuse_dir_open,
1663 .release = fuse_dir_release,
1664 .fsync = fuse_dir_fsync,
1665 .unlocked_ioctl = fuse_dir_ioctl,
1666 .compat_ioctl = fuse_dir_compat_ioctl,
1667};
1668
1669static const struct inode_operations fuse_common_inode_operations = {
1670 .setattr = fuse_setattr,
1671 .permission = fuse_permission,
1672 .getattr = fuse_getattr,
1673 .setxattr = fuse_setxattr,
1674 .getxattr = fuse_getxattr,
1675 .listxattr = fuse_listxattr,
1676 .removexattr = fuse_removexattr,
1677};
1678
1679static const struct inode_operations fuse_symlink_inode_operations = {
1680 .setattr = fuse_setattr,
1681 .follow_link = fuse_follow_link,
1682 .put_link = fuse_put_link,
1683 .readlink = generic_readlink,
1684 .getattr = fuse_getattr,
1685 .setxattr = fuse_setxattr,
1686 .getxattr = fuse_getxattr,
1687 .listxattr = fuse_listxattr,
1688 .removexattr = fuse_removexattr,
1689};
1690
1691void fuse_init_common(struct inode *inode)
1692{
1693 inode->i_op = &fuse_common_inode_operations;
1694}
1695
1696void fuse_init_dir(struct inode *inode)
1697{
1698 inode->i_op = &fuse_dir_inode_operations;
1699 inode->i_fop = &fuse_dir_operations;
1700}
1701
1702void fuse_init_symlink(struct inode *inode)
1703{
1704 inode->i_op = &fuse_symlink_inode_operations;
1705}