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fuse: general infrastructure for pages[] of variable size
[deliverable/linux.git] / fs / fuse / dir.c
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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, unsigned int flags)
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 (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 (!hlist_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 unsigned int flags)
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 struct file *file, unsigned flags,
374 umode_t mode, int *opened)
375{
376 int err;
377 struct inode *inode;
378 struct fuse_conn *fc = get_fuse_conn(dir);
379 struct fuse_req *req;
380 struct fuse_forget_link *forget;
381 struct fuse_create_in inarg;
382 struct fuse_open_out outopen;
383 struct fuse_entry_out outentry;
384 struct fuse_file *ff;
385
386 /* Userspace expects S_IFREG in create mode */
387 BUG_ON((mode & S_IFMT) != S_IFREG);
388
389 forget = fuse_alloc_forget();
390 err = -ENOMEM;
391 if (!forget)
392 goto out_err;
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 goto out_free_ff;
433
434 err = -EIO;
435 if (!S_ISREG(outentry.attr.mode) || invalid_nodeid(outentry.nodeid))
436 goto out_free_ff;
437
438 fuse_put_request(fc, req);
439 ff->fh = outopen.fh;
440 ff->nodeid = outentry.nodeid;
441 ff->open_flags = outopen.open_flags;
442 inode = fuse_iget(dir->i_sb, outentry.nodeid, outentry.generation,
443 &outentry.attr, entry_attr_timeout(&outentry), 0);
444 if (!inode) {
445 flags &= ~(O_CREAT | O_EXCL | O_TRUNC);
446 fuse_sync_release(ff, flags);
447 fuse_queue_forget(fc, forget, outentry.nodeid, 1);
448 err = -ENOMEM;
449 goto out_err;
450 }
451 kfree(forget);
452 d_instantiate(entry, inode);
453 fuse_change_entry_timeout(entry, &outentry);
454 fuse_invalidate_attr(dir);
455 err = finish_open(file, entry, generic_file_open, opened);
456 if (err) {
457 fuse_sync_release(ff, flags);
458 } else {
459 file->private_data = fuse_file_get(ff);
460 fuse_finish_open(inode, file);
461 }
462 return err;
463
464out_free_ff:
465 fuse_file_free(ff);
466out_put_request:
467 fuse_put_request(fc, req);
468out_put_forget_req:
469 kfree(forget);
470out_err:
471 return err;
472}
473
474static int fuse_mknod(struct inode *, struct dentry *, umode_t, dev_t);
475static int fuse_atomic_open(struct inode *dir, struct dentry *entry,
476 struct file *file, unsigned flags,
477 umode_t mode, int *opened)
478{
479 int err;
480 struct fuse_conn *fc = get_fuse_conn(dir);
481 struct dentry *res = NULL;
482
483 if (d_unhashed(entry)) {
484 res = fuse_lookup(dir, entry, 0);
485 if (IS_ERR(res))
486 return PTR_ERR(res);
487
488 if (res)
489 entry = res;
490 }
491
492 if (!(flags & O_CREAT) || entry->d_inode)
493 goto no_open;
494
495 /* Only creates */
496 *opened |= FILE_CREATED;
497
498 if (fc->no_create)
499 goto mknod;
500
501 err = fuse_create_open(dir, entry, file, flags, mode, opened);
502 if (err == -ENOSYS) {
503 fc->no_create = 1;
504 goto mknod;
505 }
506out_dput:
507 dput(res);
508 return err;
509
510mknod:
511 err = fuse_mknod(dir, entry, mode, 0);
512 if (err)
513 goto out_dput;
514no_open:
515 return finish_no_open(file, res);
516}
517
518/*
519 * Code shared between mknod, mkdir, symlink and link
520 */
521static int create_new_entry(struct fuse_conn *fc, struct fuse_req *req,
522 struct inode *dir, struct dentry *entry,
523 umode_t mode)
524{
525 struct fuse_entry_out outarg;
526 struct inode *inode;
527 int err;
528 struct fuse_forget_link *forget;
529
530 forget = fuse_alloc_forget();
531 if (!forget) {
532 fuse_put_request(fc, req);
533 return -ENOMEM;
534 }
535
536 memset(&outarg, 0, sizeof(outarg));
537 req->in.h.nodeid = get_node_id(dir);
538 req->out.numargs = 1;
539 if (fc->minor < 9)
540 req->out.args[0].size = FUSE_COMPAT_ENTRY_OUT_SIZE;
541 else
542 req->out.args[0].size = sizeof(outarg);
543 req->out.args[0].value = &outarg;
544 fuse_request_send(fc, req);
545 err = req->out.h.error;
546 fuse_put_request(fc, req);
547 if (err)
548 goto out_put_forget_req;
549
550 err = -EIO;
551 if (invalid_nodeid(outarg.nodeid))
552 goto out_put_forget_req;
553
554 if ((outarg.attr.mode ^ mode) & S_IFMT)
555 goto out_put_forget_req;
556
557 inode = fuse_iget(dir->i_sb, outarg.nodeid, outarg.generation,
558 &outarg.attr, entry_attr_timeout(&outarg), 0);
559 if (!inode) {
560 fuse_queue_forget(fc, forget, outarg.nodeid, 1);
561 return -ENOMEM;
562 }
563 kfree(forget);
564
565 if (S_ISDIR(inode->i_mode)) {
566 struct dentry *alias;
567 mutex_lock(&fc->inst_mutex);
568 alias = d_find_alias(inode);
569 if (alias) {
570 /* New directory must have moved since mkdir */
571 mutex_unlock(&fc->inst_mutex);
572 dput(alias);
573 iput(inode);
574 return -EBUSY;
575 }
576 d_instantiate(entry, inode);
577 mutex_unlock(&fc->inst_mutex);
578 } else
579 d_instantiate(entry, inode);
580
581 fuse_change_entry_timeout(entry, &outarg);
582 fuse_invalidate_attr(dir);
583 return 0;
584
585 out_put_forget_req:
586 kfree(forget);
587 return err;
588}
589
590static int fuse_mknod(struct inode *dir, struct dentry *entry, umode_t mode,
591 dev_t rdev)
592{
593 struct fuse_mknod_in inarg;
594 struct fuse_conn *fc = get_fuse_conn(dir);
595 struct fuse_req *req = fuse_get_req(fc);
596 if (IS_ERR(req))
597 return PTR_ERR(req);
598
599 if (!fc->dont_mask)
600 mode &= ~current_umask();
601
602 memset(&inarg, 0, sizeof(inarg));
603 inarg.mode = mode;
604 inarg.rdev = new_encode_dev(rdev);
605 inarg.umask = current_umask();
606 req->in.h.opcode = FUSE_MKNOD;
607 req->in.numargs = 2;
608 req->in.args[0].size = fc->minor < 12 ? FUSE_COMPAT_MKNOD_IN_SIZE :
609 sizeof(inarg);
610 req->in.args[0].value = &inarg;
611 req->in.args[1].size = entry->d_name.len + 1;
612 req->in.args[1].value = entry->d_name.name;
613 return create_new_entry(fc, req, dir, entry, mode);
614}
615
616static int fuse_create(struct inode *dir, struct dentry *entry, umode_t mode,
617 bool excl)
618{
619 return fuse_mknod(dir, entry, mode, 0);
620}
621
622static int fuse_mkdir(struct inode *dir, struct dentry *entry, umode_t mode)
623{
624 struct fuse_mkdir_in inarg;
625 struct fuse_conn *fc = get_fuse_conn(dir);
626 struct fuse_req *req = fuse_get_req(fc);
627 if (IS_ERR(req))
628 return PTR_ERR(req);
629
630 if (!fc->dont_mask)
631 mode &= ~current_umask();
632
633 memset(&inarg, 0, sizeof(inarg));
634 inarg.mode = mode;
635 inarg.umask = current_umask();
636 req->in.h.opcode = FUSE_MKDIR;
637 req->in.numargs = 2;
638 req->in.args[0].size = sizeof(inarg);
639 req->in.args[0].value = &inarg;
640 req->in.args[1].size = entry->d_name.len + 1;
641 req->in.args[1].value = entry->d_name.name;
642 return create_new_entry(fc, req, dir, entry, S_IFDIR);
643}
644
645static int fuse_symlink(struct inode *dir, struct dentry *entry,
646 const char *link)
647{
648 struct fuse_conn *fc = get_fuse_conn(dir);
649 unsigned len = strlen(link) + 1;
650 struct fuse_req *req = fuse_get_req(fc);
651 if (IS_ERR(req))
652 return PTR_ERR(req);
653
654 req->in.h.opcode = FUSE_SYMLINK;
655 req->in.numargs = 2;
656 req->in.args[0].size = entry->d_name.len + 1;
657 req->in.args[0].value = entry->d_name.name;
658 req->in.args[1].size = len;
659 req->in.args[1].value = link;
660 return create_new_entry(fc, req, dir, entry, S_IFLNK);
661}
662
663static int fuse_unlink(struct inode *dir, struct dentry *entry)
664{
665 int err;
666 struct fuse_conn *fc = get_fuse_conn(dir);
667 struct fuse_req *req = fuse_get_req(fc);
668 if (IS_ERR(req))
669 return PTR_ERR(req);
670
671 req->in.h.opcode = FUSE_UNLINK;
672 req->in.h.nodeid = get_node_id(dir);
673 req->in.numargs = 1;
674 req->in.args[0].size = entry->d_name.len + 1;
675 req->in.args[0].value = entry->d_name.name;
676 fuse_request_send(fc, req);
677 err = req->out.h.error;
678 fuse_put_request(fc, req);
679 if (!err) {
680 struct inode *inode = entry->d_inode;
681 struct fuse_inode *fi = get_fuse_inode(inode);
682
683 spin_lock(&fc->lock);
684 fi->attr_version = ++fc->attr_version;
685 drop_nlink(inode);
686 spin_unlock(&fc->lock);
687 fuse_invalidate_attr(inode);
688 fuse_invalidate_attr(dir);
689 fuse_invalidate_entry_cache(entry);
690 } else if (err == -EINTR)
691 fuse_invalidate_entry(entry);
692 return err;
693}
694
695static int fuse_rmdir(struct inode *dir, struct dentry *entry)
696{
697 int err;
698 struct fuse_conn *fc = get_fuse_conn(dir);
699 struct fuse_req *req = fuse_get_req(fc);
700 if (IS_ERR(req))
701 return PTR_ERR(req);
702
703 req->in.h.opcode = FUSE_RMDIR;
704 req->in.h.nodeid = get_node_id(dir);
705 req->in.numargs = 1;
706 req->in.args[0].size = entry->d_name.len + 1;
707 req->in.args[0].value = entry->d_name.name;
708 fuse_request_send(fc, req);
709 err = req->out.h.error;
710 fuse_put_request(fc, req);
711 if (!err) {
712 clear_nlink(entry->d_inode);
713 fuse_invalidate_attr(dir);
714 fuse_invalidate_entry_cache(entry);
715 } else if (err == -EINTR)
716 fuse_invalidate_entry(entry);
717 return err;
718}
719
720static int fuse_rename(struct inode *olddir, struct dentry *oldent,
721 struct inode *newdir, struct dentry *newent)
722{
723 int err;
724 struct fuse_rename_in inarg;
725 struct fuse_conn *fc = get_fuse_conn(olddir);
726 struct fuse_req *req = fuse_get_req(fc);
727
728 if (IS_ERR(req))
729 return PTR_ERR(req);
730
731 memset(&inarg, 0, sizeof(inarg));
732 inarg.newdir = get_node_id(newdir);
733 req->in.h.opcode = FUSE_RENAME;
734 req->in.h.nodeid = get_node_id(olddir);
735 req->in.numargs = 3;
736 req->in.args[0].size = sizeof(inarg);
737 req->in.args[0].value = &inarg;
738 req->in.args[1].size = oldent->d_name.len + 1;
739 req->in.args[1].value = oldent->d_name.name;
740 req->in.args[2].size = newent->d_name.len + 1;
741 req->in.args[2].value = newent->d_name.name;
742 fuse_request_send(fc, req);
743 err = req->out.h.error;
744 fuse_put_request(fc, req);
745 if (!err) {
746 /* ctime changes */
747 fuse_invalidate_attr(oldent->d_inode);
748
749 fuse_invalidate_attr(olddir);
750 if (olddir != newdir)
751 fuse_invalidate_attr(newdir);
752
753 /* newent will end up negative */
754 if (newent->d_inode) {
755 fuse_invalidate_attr(newent->d_inode);
756 fuse_invalidate_entry_cache(newent);
757 }
758 } else if (err == -EINTR) {
759 /* If request was interrupted, DEITY only knows if the
760 rename actually took place. If the invalidation
761 fails (e.g. some process has CWD under the renamed
762 directory), then there can be inconsistency between
763 the dcache and the real filesystem. Tough luck. */
764 fuse_invalidate_entry(oldent);
765 if (newent->d_inode)
766 fuse_invalidate_entry(newent);
767 }
768
769 return err;
770}
771
772static int fuse_link(struct dentry *entry, struct inode *newdir,
773 struct dentry *newent)
774{
775 int err;
776 struct fuse_link_in inarg;
777 struct inode *inode = entry->d_inode;
778 struct fuse_conn *fc = get_fuse_conn(inode);
779 struct fuse_req *req = fuse_get_req(fc);
780 if (IS_ERR(req))
781 return PTR_ERR(req);
782
783 memset(&inarg, 0, sizeof(inarg));
784 inarg.oldnodeid = get_node_id(inode);
785 req->in.h.opcode = FUSE_LINK;
786 req->in.numargs = 2;
787 req->in.args[0].size = sizeof(inarg);
788 req->in.args[0].value = &inarg;
789 req->in.args[1].size = newent->d_name.len + 1;
790 req->in.args[1].value = newent->d_name.name;
791 err = create_new_entry(fc, req, newdir, newent, inode->i_mode);
792 /* Contrary to "normal" filesystems it can happen that link
793 makes two "logical" inodes point to the same "physical"
794 inode. We invalidate the attributes of the old one, so it
795 will reflect changes in the backing inode (link count,
796 etc.)
797 */
798 if (!err) {
799 struct fuse_inode *fi = get_fuse_inode(inode);
800
801 spin_lock(&fc->lock);
802 fi->attr_version = ++fc->attr_version;
803 inc_nlink(inode);
804 spin_unlock(&fc->lock);
805 fuse_invalidate_attr(inode);
806 } else if (err == -EINTR) {
807 fuse_invalidate_attr(inode);
808 }
809 return err;
810}
811
812static void fuse_fillattr(struct inode *inode, struct fuse_attr *attr,
813 struct kstat *stat)
814{
815 unsigned int blkbits;
816
817 stat->dev = inode->i_sb->s_dev;
818 stat->ino = attr->ino;
819 stat->mode = (inode->i_mode & S_IFMT) | (attr->mode & 07777);
820 stat->nlink = attr->nlink;
821 stat->uid = make_kuid(&init_user_ns, attr->uid);
822 stat->gid = make_kgid(&init_user_ns, attr->gid);
823 stat->rdev = inode->i_rdev;
824 stat->atime.tv_sec = attr->atime;
825 stat->atime.tv_nsec = attr->atimensec;
826 stat->mtime.tv_sec = attr->mtime;
827 stat->mtime.tv_nsec = attr->mtimensec;
828 stat->ctime.tv_sec = attr->ctime;
829 stat->ctime.tv_nsec = attr->ctimensec;
830 stat->size = attr->size;
831 stat->blocks = attr->blocks;
832
833 if (attr->blksize != 0)
834 blkbits = ilog2(attr->blksize);
835 else
836 blkbits = inode->i_sb->s_blocksize_bits;
837
838 stat->blksize = 1 << blkbits;
839}
840
841static int fuse_do_getattr(struct inode *inode, struct kstat *stat,
842 struct file *file)
843{
844 int err;
845 struct fuse_getattr_in inarg;
846 struct fuse_attr_out outarg;
847 struct fuse_conn *fc = get_fuse_conn(inode);
848 struct fuse_req *req;
849 u64 attr_version;
850
851 req = fuse_get_req(fc);
852 if (IS_ERR(req))
853 return PTR_ERR(req);
854
855 attr_version = fuse_get_attr_version(fc);
856
857 memset(&inarg, 0, sizeof(inarg));
858 memset(&outarg, 0, sizeof(outarg));
859 /* Directories have separate file-handle space */
860 if (file && S_ISREG(inode->i_mode)) {
861 struct fuse_file *ff = file->private_data;
862
863 inarg.getattr_flags |= FUSE_GETATTR_FH;
864 inarg.fh = ff->fh;
865 }
866 req->in.h.opcode = FUSE_GETATTR;
867 req->in.h.nodeid = get_node_id(inode);
868 req->in.numargs = 1;
869 req->in.args[0].size = sizeof(inarg);
870 req->in.args[0].value = &inarg;
871 req->out.numargs = 1;
872 if (fc->minor < 9)
873 req->out.args[0].size = FUSE_COMPAT_ATTR_OUT_SIZE;
874 else
875 req->out.args[0].size = sizeof(outarg);
876 req->out.args[0].value = &outarg;
877 fuse_request_send(fc, req);
878 err = req->out.h.error;
879 fuse_put_request(fc, req);
880 if (!err) {
881 if ((inode->i_mode ^ outarg.attr.mode) & S_IFMT) {
882 make_bad_inode(inode);
883 err = -EIO;
884 } else {
885 fuse_change_attributes(inode, &outarg.attr,
886 attr_timeout(&outarg),
887 attr_version);
888 if (stat)
889 fuse_fillattr(inode, &outarg.attr, stat);
890 }
891 }
892 return err;
893}
894
895int fuse_update_attributes(struct inode *inode, struct kstat *stat,
896 struct file *file, bool *refreshed)
897{
898 struct fuse_inode *fi = get_fuse_inode(inode);
899 int err;
900 bool r;
901
902 if (fi->i_time < get_jiffies_64()) {
903 r = true;
904 err = fuse_do_getattr(inode, stat, file);
905 } else {
906 r = false;
907 err = 0;
908 if (stat) {
909 generic_fillattr(inode, stat);
910 stat->mode = fi->orig_i_mode;
911 stat->ino = fi->orig_ino;
912 }
913 }
914
915 if (refreshed != NULL)
916 *refreshed = r;
917
918 return err;
919}
920
921int fuse_reverse_inval_entry(struct super_block *sb, u64 parent_nodeid,
922 u64 child_nodeid, struct qstr *name)
923{
924 int err = -ENOTDIR;
925 struct inode *parent;
926 struct dentry *dir;
927 struct dentry *entry;
928
929 parent = ilookup5(sb, parent_nodeid, fuse_inode_eq, &parent_nodeid);
930 if (!parent)
931 return -ENOENT;
932
933 mutex_lock(&parent->i_mutex);
934 if (!S_ISDIR(parent->i_mode))
935 goto unlock;
936
937 err = -ENOENT;
938 dir = d_find_alias(parent);
939 if (!dir)
940 goto unlock;
941
942 entry = d_lookup(dir, name);
943 dput(dir);
944 if (!entry)
945 goto unlock;
946
947 fuse_invalidate_attr(parent);
948 fuse_invalidate_entry(entry);
949
950 if (child_nodeid != 0 && entry->d_inode) {
951 mutex_lock(&entry->d_inode->i_mutex);
952 if (get_node_id(entry->d_inode) != child_nodeid) {
953 err = -ENOENT;
954 goto badentry;
955 }
956 if (d_mountpoint(entry)) {
957 err = -EBUSY;
958 goto badentry;
959 }
960 if (S_ISDIR(entry->d_inode->i_mode)) {
961 shrink_dcache_parent(entry);
962 if (!simple_empty(entry)) {
963 err = -ENOTEMPTY;
964 goto badentry;
965 }
966 entry->d_inode->i_flags |= S_DEAD;
967 }
968 dont_mount(entry);
969 clear_nlink(entry->d_inode);
970 err = 0;
971 badentry:
972 mutex_unlock(&entry->d_inode->i_mutex);
973 if (!err)
974 d_delete(entry);
975 } else {
976 err = 0;
977 }
978 dput(entry);
979
980 unlock:
981 mutex_unlock(&parent->i_mutex);
982 iput(parent);
983 return err;
984}
985
986/*
987 * Calling into a user-controlled filesystem gives the filesystem
988 * daemon ptrace-like capabilities over the requester process. This
989 * means, that the filesystem daemon is able to record the exact
990 * filesystem operations performed, and can also control the behavior
991 * of the requester process in otherwise impossible ways. For example
992 * it can delay the operation for arbitrary length of time allowing
993 * DoS against the requester.
994 *
995 * For this reason only those processes can call into the filesystem,
996 * for which the owner of the mount has ptrace privilege. This
997 * excludes processes started by other users, suid or sgid processes.
998 */
999int fuse_allow_task(struct fuse_conn *fc, struct task_struct *task)
1000{
1001 const struct cred *cred;
1002 int ret;
1003
1004 if (fc->flags & FUSE_ALLOW_OTHER)
1005 return 1;
1006
1007 rcu_read_lock();
1008 ret = 0;
1009 cred = __task_cred(task);
1010 if (uid_eq(cred->euid, fc->user_id) &&
1011 uid_eq(cred->suid, fc->user_id) &&
1012 uid_eq(cred->uid, fc->user_id) &&
1013 gid_eq(cred->egid, fc->group_id) &&
1014 gid_eq(cred->sgid, fc->group_id) &&
1015 gid_eq(cred->gid, fc->group_id))
1016 ret = 1;
1017 rcu_read_unlock();
1018
1019 return ret;
1020}
1021
1022static int fuse_access(struct inode *inode, int mask)
1023{
1024 struct fuse_conn *fc = get_fuse_conn(inode);
1025 struct fuse_req *req;
1026 struct fuse_access_in inarg;
1027 int err;
1028
1029 if (fc->no_access)
1030 return 0;
1031
1032 req = fuse_get_req(fc);
1033 if (IS_ERR(req))
1034 return PTR_ERR(req);
1035
1036 memset(&inarg, 0, sizeof(inarg));
1037 inarg.mask = mask & (MAY_READ | MAY_WRITE | MAY_EXEC);
1038 req->in.h.opcode = FUSE_ACCESS;
1039 req->in.h.nodeid = get_node_id(inode);
1040 req->in.numargs = 1;
1041 req->in.args[0].size = sizeof(inarg);
1042 req->in.args[0].value = &inarg;
1043 fuse_request_send(fc, req);
1044 err = req->out.h.error;
1045 fuse_put_request(fc, req);
1046 if (err == -ENOSYS) {
1047 fc->no_access = 1;
1048 err = 0;
1049 }
1050 return err;
1051}
1052
1053static int fuse_perm_getattr(struct inode *inode, int mask)
1054{
1055 if (mask & MAY_NOT_BLOCK)
1056 return -ECHILD;
1057
1058 return fuse_do_getattr(inode, NULL, NULL);
1059}
1060
1061/*
1062 * Check permission. The two basic access models of FUSE are:
1063 *
1064 * 1) Local access checking ('default_permissions' mount option) based
1065 * on file mode. This is the plain old disk filesystem permission
1066 * modell.
1067 *
1068 * 2) "Remote" access checking, where server is responsible for
1069 * checking permission in each inode operation. An exception to this
1070 * is if ->permission() was invoked from sys_access() in which case an
1071 * access request is sent. Execute permission is still checked
1072 * locally based on file mode.
1073 */
1074static int fuse_permission(struct inode *inode, int mask)
1075{
1076 struct fuse_conn *fc = get_fuse_conn(inode);
1077 bool refreshed = false;
1078 int err = 0;
1079
1080 if (!fuse_allow_task(fc, current))
1081 return -EACCES;
1082
1083 /*
1084 * If attributes are needed, refresh them before proceeding
1085 */
1086 if ((fc->flags & FUSE_DEFAULT_PERMISSIONS) ||
1087 ((mask & MAY_EXEC) && S_ISREG(inode->i_mode))) {
1088 struct fuse_inode *fi = get_fuse_inode(inode);
1089
1090 if (fi->i_time < get_jiffies_64()) {
1091 refreshed = true;
1092
1093 err = fuse_perm_getattr(inode, mask);
1094 if (err)
1095 return err;
1096 }
1097 }
1098
1099 if (fc->flags & FUSE_DEFAULT_PERMISSIONS) {
1100 err = generic_permission(inode, mask);
1101
1102 /* If permission is denied, try to refresh file
1103 attributes. This is also needed, because the root
1104 node will at first have no permissions */
1105 if (err == -EACCES && !refreshed) {
1106 err = fuse_perm_getattr(inode, mask);
1107 if (!err)
1108 err = generic_permission(inode, mask);
1109 }
1110
1111 /* Note: the opposite of the above test does not
1112 exist. So if permissions are revoked this won't be
1113 noticed immediately, only after the attribute
1114 timeout has expired */
1115 } else if (mask & (MAY_ACCESS | MAY_CHDIR)) {
1116 if (mask & MAY_NOT_BLOCK)
1117 return -ECHILD;
1118
1119 err = fuse_access(inode, mask);
1120 } else if ((mask & MAY_EXEC) && S_ISREG(inode->i_mode)) {
1121 if (!(inode->i_mode & S_IXUGO)) {
1122 if (refreshed)
1123 return -EACCES;
1124
1125 err = fuse_perm_getattr(inode, mask);
1126 if (!err && !(inode->i_mode & S_IXUGO))
1127 return -EACCES;
1128 }
1129 }
1130 return err;
1131}
1132
1133static int parse_dirfile(char *buf, size_t nbytes, struct file *file,
1134 void *dstbuf, filldir_t filldir)
1135{
1136 while (nbytes >= FUSE_NAME_OFFSET) {
1137 struct fuse_dirent *dirent = (struct fuse_dirent *) buf;
1138 size_t reclen = FUSE_DIRENT_SIZE(dirent);
1139 int over;
1140 if (!dirent->namelen || dirent->namelen > FUSE_NAME_MAX)
1141 return -EIO;
1142 if (reclen > nbytes)
1143 break;
1144
1145 over = filldir(dstbuf, dirent->name, dirent->namelen,
1146 file->f_pos, dirent->ino, dirent->type);
1147 if (over)
1148 break;
1149
1150 buf += reclen;
1151 nbytes -= reclen;
1152 file->f_pos = dirent->off;
1153 }
1154
1155 return 0;
1156}
1157
1158static int fuse_direntplus_link(struct file *file,
1159 struct fuse_direntplus *direntplus,
1160 u64 attr_version)
1161{
1162 int err;
1163 struct fuse_entry_out *o = &direntplus->entry_out;
1164 struct fuse_dirent *dirent = &direntplus->dirent;
1165 struct dentry *parent = file->f_path.dentry;
1166 struct qstr name = QSTR_INIT(dirent->name, dirent->namelen);
1167 struct dentry *dentry;
1168 struct dentry *alias;
1169 struct inode *dir = parent->d_inode;
1170 struct fuse_conn *fc;
1171 struct inode *inode;
1172
1173 if (!o->nodeid) {
1174 /*
1175 * Unlike in the case of fuse_lookup, zero nodeid does not mean
1176 * ENOENT. Instead, it only means the userspace filesystem did
1177 * not want to return attributes/handle for this entry.
1178 *
1179 * So do nothing.
1180 */
1181 return 0;
1182 }
1183
1184 if (name.name[0] == '.') {
1185 /*
1186 * We could potentially refresh the attributes of the directory
1187 * and its parent?
1188 */
1189 if (name.len == 1)
1190 return 0;
1191 if (name.name[1] == '.' && name.len == 2)
1192 return 0;
1193 }
1194 fc = get_fuse_conn(dir);
1195
1196 name.hash = full_name_hash(name.name, name.len);
1197 dentry = d_lookup(parent, &name);
1198 if (dentry && dentry->d_inode) {
1199 inode = dentry->d_inode;
1200 if (get_node_id(inode) == o->nodeid) {
1201 struct fuse_inode *fi;
1202 fi = get_fuse_inode(inode);
1203 spin_lock(&fc->lock);
1204 fi->nlookup++;
1205 spin_unlock(&fc->lock);
1206
1207 /*
1208 * The other branch to 'found' comes via fuse_iget()
1209 * which bumps nlookup inside
1210 */
1211 goto found;
1212 }
1213 err = d_invalidate(dentry);
1214 if (err)
1215 goto out;
1216 dput(dentry);
1217 dentry = NULL;
1218 }
1219
1220 dentry = d_alloc(parent, &name);
1221 err = -ENOMEM;
1222 if (!dentry)
1223 goto out;
1224
1225 inode = fuse_iget(dir->i_sb, o->nodeid, o->generation,
1226 &o->attr, entry_attr_timeout(o), attr_version);
1227 if (!inode)
1228 goto out;
1229
1230 alias = d_materialise_unique(dentry, inode);
1231 err = PTR_ERR(alias);
1232 if (IS_ERR(alias))
1233 goto out;
1234 if (alias) {
1235 dput(dentry);
1236 dentry = alias;
1237 }
1238
1239found:
1240 fuse_change_attributes(inode, &o->attr, entry_attr_timeout(o),
1241 attr_version);
1242
1243 fuse_change_entry_timeout(dentry, o);
1244
1245 err = 0;
1246out:
1247 if (dentry)
1248 dput(dentry);
1249 return err;
1250}
1251
1252static int parse_dirplusfile(char *buf, size_t nbytes, struct file *file,
1253 void *dstbuf, filldir_t filldir, u64 attr_version)
1254{
1255 struct fuse_direntplus *direntplus;
1256 struct fuse_dirent *dirent;
1257 size_t reclen;
1258 int over = 0;
1259 int ret;
1260
1261 while (nbytes >= FUSE_NAME_OFFSET_DIRENTPLUS) {
1262 direntplus = (struct fuse_direntplus *) buf;
1263 dirent = &direntplus->dirent;
1264 reclen = FUSE_DIRENTPLUS_SIZE(direntplus);
1265
1266 if (!dirent->namelen || dirent->namelen > FUSE_NAME_MAX)
1267 return -EIO;
1268 if (reclen > nbytes)
1269 break;
1270
1271 if (!over) {
1272 /* We fill entries into dstbuf only as much as
1273 it can hold. But we still continue iterating
1274 over remaining entries to link them. If not,
1275 we need to send a FORGET for each of those
1276 which we did not link.
1277 */
1278 over = filldir(dstbuf, dirent->name, dirent->namelen,
1279 file->f_pos, dirent->ino,
1280 dirent->type);
1281 file->f_pos = dirent->off;
1282 }
1283
1284 buf += reclen;
1285 nbytes -= reclen;
1286
1287 ret = fuse_direntplus_link(file, direntplus, attr_version);
1288 if (ret)
1289 fuse_force_forget(file, direntplus->entry_out.nodeid);
1290 }
1291
1292 return 0;
1293}
1294
1295static int fuse_readdir(struct file *file, void *dstbuf, filldir_t filldir)
1296{
1297 int err;
1298 size_t nbytes;
1299 struct page *page;
1300 struct inode *inode = file->f_path.dentry->d_inode;
1301 struct fuse_conn *fc = get_fuse_conn(inode);
1302 struct fuse_req *req;
1303 u64 attr_version = 0;
1304
1305 if (is_bad_inode(inode))
1306 return -EIO;
1307
1308 req = fuse_get_req(fc);
1309 if (IS_ERR(req))
1310 return PTR_ERR(req);
1311
1312 page = alloc_page(GFP_KERNEL);
1313 if (!page) {
1314 fuse_put_request(fc, req);
1315 return -ENOMEM;
1316 }
1317 req->out.argpages = 1;
1318 req->num_pages = 1;
1319 req->pages[0] = page;
1320 if (fc->do_readdirplus) {
1321 attr_version = fuse_get_attr_version(fc);
1322 fuse_read_fill(req, file, file->f_pos, PAGE_SIZE,
1323 FUSE_READDIRPLUS);
1324 } else {
1325 fuse_read_fill(req, file, file->f_pos, PAGE_SIZE,
1326 FUSE_READDIR);
1327 }
1328 fuse_request_send(fc, req);
1329 nbytes = req->out.args[0].size;
1330 err = req->out.h.error;
1331 fuse_put_request(fc, req);
1332 if (!err) {
1333 if (fc->do_readdirplus) {
1334 err = parse_dirplusfile(page_address(page), nbytes,
1335 file, dstbuf, filldir,
1336 attr_version);
1337 } else {
1338 err = parse_dirfile(page_address(page), nbytes, file,
1339 dstbuf, filldir);
1340 }
1341 }
1342
1343 __free_page(page);
1344 fuse_invalidate_attr(inode); /* atime changed */
1345 return err;
1346}
1347
1348static char *read_link(struct dentry *dentry)
1349{
1350 struct inode *inode = dentry->d_inode;
1351 struct fuse_conn *fc = get_fuse_conn(inode);
1352 struct fuse_req *req = fuse_get_req(fc);
1353 char *link;
1354
1355 if (IS_ERR(req))
1356 return ERR_CAST(req);
1357
1358 link = (char *) __get_free_page(GFP_KERNEL);
1359 if (!link) {
1360 link = ERR_PTR(-ENOMEM);
1361 goto out;
1362 }
1363 req->in.h.opcode = FUSE_READLINK;
1364 req->in.h.nodeid = get_node_id(inode);
1365 req->out.argvar = 1;
1366 req->out.numargs = 1;
1367 req->out.args[0].size = PAGE_SIZE - 1;
1368 req->out.args[0].value = link;
1369 fuse_request_send(fc, req);
1370 if (req->out.h.error) {
1371 free_page((unsigned long) link);
1372 link = ERR_PTR(req->out.h.error);
1373 } else
1374 link[req->out.args[0].size] = '\0';
1375 out:
1376 fuse_put_request(fc, req);
1377 fuse_invalidate_attr(inode); /* atime changed */
1378 return link;
1379}
1380
1381static void free_link(char *link)
1382{
1383 if (!IS_ERR(link))
1384 free_page((unsigned long) link);
1385}
1386
1387static void *fuse_follow_link(struct dentry *dentry, struct nameidata *nd)
1388{
1389 nd_set_link(nd, read_link(dentry));
1390 return NULL;
1391}
1392
1393static void fuse_put_link(struct dentry *dentry, struct nameidata *nd, void *c)
1394{
1395 free_link(nd_get_link(nd));
1396}
1397
1398static int fuse_dir_open(struct inode *inode, struct file *file)
1399{
1400 return fuse_open_common(inode, file, true);
1401}
1402
1403static int fuse_dir_release(struct inode *inode, struct file *file)
1404{
1405 fuse_release_common(file, FUSE_RELEASEDIR);
1406
1407 return 0;
1408}
1409
1410static int fuse_dir_fsync(struct file *file, loff_t start, loff_t end,
1411 int datasync)
1412{
1413 return fuse_fsync_common(file, start, end, datasync, 1);
1414}
1415
1416static long fuse_dir_ioctl(struct file *file, unsigned int cmd,
1417 unsigned long arg)
1418{
1419 struct fuse_conn *fc = get_fuse_conn(file->f_mapping->host);
1420
1421 /* FUSE_IOCTL_DIR only supported for API version >= 7.18 */
1422 if (fc->minor < 18)
1423 return -ENOTTY;
1424
1425 return fuse_ioctl_common(file, cmd, arg, FUSE_IOCTL_DIR);
1426}
1427
1428static long fuse_dir_compat_ioctl(struct file *file, unsigned int cmd,
1429 unsigned long arg)
1430{
1431 struct fuse_conn *fc = get_fuse_conn(file->f_mapping->host);
1432
1433 if (fc->minor < 18)
1434 return -ENOTTY;
1435
1436 return fuse_ioctl_common(file, cmd, arg,
1437 FUSE_IOCTL_COMPAT | FUSE_IOCTL_DIR);
1438}
1439
1440static bool update_mtime(unsigned ivalid)
1441{
1442 /* Always update if mtime is explicitly set */
1443 if (ivalid & ATTR_MTIME_SET)
1444 return true;
1445
1446 /* If it's an open(O_TRUNC) or an ftruncate(), don't update */
1447 if ((ivalid & ATTR_SIZE) && (ivalid & (ATTR_OPEN | ATTR_FILE)))
1448 return false;
1449
1450 /* In all other cases update */
1451 return true;
1452}
1453
1454static void iattr_to_fattr(struct iattr *iattr, struct fuse_setattr_in *arg)
1455{
1456 unsigned ivalid = iattr->ia_valid;
1457
1458 if (ivalid & ATTR_MODE)
1459 arg->valid |= FATTR_MODE, arg->mode = iattr->ia_mode;
1460 if (ivalid & ATTR_UID)
1461 arg->valid |= FATTR_UID, arg->uid = from_kuid(&init_user_ns, iattr->ia_uid);
1462 if (ivalid & ATTR_GID)
1463 arg->valid |= FATTR_GID, arg->gid = from_kgid(&init_user_ns, iattr->ia_gid);
1464 if (ivalid & ATTR_SIZE)
1465 arg->valid |= FATTR_SIZE, arg->size = iattr->ia_size;
1466 if (ivalid & ATTR_ATIME) {
1467 arg->valid |= FATTR_ATIME;
1468 arg->atime = iattr->ia_atime.tv_sec;
1469 arg->atimensec = iattr->ia_atime.tv_nsec;
1470 if (!(ivalid & ATTR_ATIME_SET))
1471 arg->valid |= FATTR_ATIME_NOW;
1472 }
1473 if ((ivalid & ATTR_MTIME) && update_mtime(ivalid)) {
1474 arg->valid |= FATTR_MTIME;
1475 arg->mtime = iattr->ia_mtime.tv_sec;
1476 arg->mtimensec = iattr->ia_mtime.tv_nsec;
1477 if (!(ivalid & ATTR_MTIME_SET))
1478 arg->valid |= FATTR_MTIME_NOW;
1479 }
1480}
1481
1482/*
1483 * Prevent concurrent writepages on inode
1484 *
1485 * This is done by adding a negative bias to the inode write counter
1486 * and waiting for all pending writes to finish.
1487 */
1488void fuse_set_nowrite(struct inode *inode)
1489{
1490 struct fuse_conn *fc = get_fuse_conn(inode);
1491 struct fuse_inode *fi = get_fuse_inode(inode);
1492
1493 BUG_ON(!mutex_is_locked(&inode->i_mutex));
1494
1495 spin_lock(&fc->lock);
1496 BUG_ON(fi->writectr < 0);
1497 fi->writectr += FUSE_NOWRITE;
1498 spin_unlock(&fc->lock);
1499 wait_event(fi->page_waitq, fi->writectr == FUSE_NOWRITE);
1500}
1501
1502/*
1503 * Allow writepages on inode
1504 *
1505 * Remove the bias from the writecounter and send any queued
1506 * writepages.
1507 */
1508static void __fuse_release_nowrite(struct inode *inode)
1509{
1510 struct fuse_inode *fi = get_fuse_inode(inode);
1511
1512 BUG_ON(fi->writectr != FUSE_NOWRITE);
1513 fi->writectr = 0;
1514 fuse_flush_writepages(inode);
1515}
1516
1517void fuse_release_nowrite(struct inode *inode)
1518{
1519 struct fuse_conn *fc = get_fuse_conn(inode);
1520
1521 spin_lock(&fc->lock);
1522 __fuse_release_nowrite(inode);
1523 spin_unlock(&fc->lock);
1524}
1525
1526/*
1527 * Set attributes, and at the same time refresh them.
1528 *
1529 * Truncation is slightly complicated, because the 'truncate' request
1530 * may fail, in which case we don't want to touch the mapping.
1531 * vmtruncate() doesn't allow for this case, so do the rlimit checking
1532 * and the actual truncation by hand.
1533 */
1534static int fuse_do_setattr(struct dentry *entry, struct iattr *attr,
1535 struct file *file)
1536{
1537 struct inode *inode = entry->d_inode;
1538 struct fuse_conn *fc = get_fuse_conn(inode);
1539 struct fuse_req *req;
1540 struct fuse_setattr_in inarg;
1541 struct fuse_attr_out outarg;
1542 bool is_truncate = false;
1543 loff_t oldsize;
1544 int err;
1545
1546 if (!fuse_allow_task(fc, current))
1547 return -EACCES;
1548
1549 if (!(fc->flags & FUSE_DEFAULT_PERMISSIONS))
1550 attr->ia_valid |= ATTR_FORCE;
1551
1552 err = inode_change_ok(inode, attr);
1553 if (err)
1554 return err;
1555
1556 if (attr->ia_valid & ATTR_OPEN) {
1557 if (fc->atomic_o_trunc)
1558 return 0;
1559 file = NULL;
1560 }
1561
1562 if (attr->ia_valid & ATTR_SIZE)
1563 is_truncate = true;
1564
1565 req = fuse_get_req(fc);
1566 if (IS_ERR(req))
1567 return PTR_ERR(req);
1568
1569 if (is_truncate)
1570 fuse_set_nowrite(inode);
1571
1572 memset(&inarg, 0, sizeof(inarg));
1573 memset(&outarg, 0, sizeof(outarg));
1574 iattr_to_fattr(attr, &inarg);
1575 if (file) {
1576 struct fuse_file *ff = file->private_data;
1577 inarg.valid |= FATTR_FH;
1578 inarg.fh = ff->fh;
1579 }
1580 if (attr->ia_valid & ATTR_SIZE) {
1581 /* For mandatory locking in truncate */
1582 inarg.valid |= FATTR_LOCKOWNER;
1583 inarg.lock_owner = fuse_lock_owner_id(fc, current->files);
1584 }
1585 req->in.h.opcode = FUSE_SETATTR;
1586 req->in.h.nodeid = get_node_id(inode);
1587 req->in.numargs = 1;
1588 req->in.args[0].size = sizeof(inarg);
1589 req->in.args[0].value = &inarg;
1590 req->out.numargs = 1;
1591 if (fc->minor < 9)
1592 req->out.args[0].size = FUSE_COMPAT_ATTR_OUT_SIZE;
1593 else
1594 req->out.args[0].size = sizeof(outarg);
1595 req->out.args[0].value = &outarg;
1596 fuse_request_send(fc, req);
1597 err = req->out.h.error;
1598 fuse_put_request(fc, req);
1599 if (err) {
1600 if (err == -EINTR)
1601 fuse_invalidate_attr(inode);
1602 goto error;
1603 }
1604
1605 if ((inode->i_mode ^ outarg.attr.mode) & S_IFMT) {
1606 make_bad_inode(inode);
1607 err = -EIO;
1608 goto error;
1609 }
1610
1611 spin_lock(&fc->lock);
1612 fuse_change_attributes_common(inode, &outarg.attr,
1613 attr_timeout(&outarg));
1614 oldsize = inode->i_size;
1615 i_size_write(inode, outarg.attr.size);
1616
1617 if (is_truncate) {
1618 /* NOTE: this may release/reacquire fc->lock */
1619 __fuse_release_nowrite(inode);
1620 }
1621 spin_unlock(&fc->lock);
1622
1623 /*
1624 * Only call invalidate_inode_pages2() after removing
1625 * FUSE_NOWRITE, otherwise fuse_launder_page() would deadlock.
1626 */
1627 if (S_ISREG(inode->i_mode) && oldsize != outarg.attr.size) {
1628 truncate_pagecache(inode, oldsize, outarg.attr.size);
1629 invalidate_inode_pages2(inode->i_mapping);
1630 }
1631
1632 return 0;
1633
1634error:
1635 if (is_truncate)
1636 fuse_release_nowrite(inode);
1637
1638 return err;
1639}
1640
1641static int fuse_setattr(struct dentry *entry, struct iattr *attr)
1642{
1643 if (attr->ia_valid & ATTR_FILE)
1644 return fuse_do_setattr(entry, attr, attr->ia_file);
1645 else
1646 return fuse_do_setattr(entry, attr, NULL);
1647}
1648
1649static int fuse_getattr(struct vfsmount *mnt, struct dentry *entry,
1650 struct kstat *stat)
1651{
1652 struct inode *inode = entry->d_inode;
1653 struct fuse_conn *fc = get_fuse_conn(inode);
1654
1655 if (!fuse_allow_task(fc, current))
1656 return -EACCES;
1657
1658 return fuse_update_attributes(inode, stat, NULL, NULL);
1659}
1660
1661static int fuse_setxattr(struct dentry *entry, const char *name,
1662 const void *value, size_t size, int flags)
1663{
1664 struct inode *inode = entry->d_inode;
1665 struct fuse_conn *fc = get_fuse_conn(inode);
1666 struct fuse_req *req;
1667 struct fuse_setxattr_in inarg;
1668 int err;
1669
1670 if (fc->no_setxattr)
1671 return -EOPNOTSUPP;
1672
1673 req = fuse_get_req(fc);
1674 if (IS_ERR(req))
1675 return PTR_ERR(req);
1676
1677 memset(&inarg, 0, sizeof(inarg));
1678 inarg.size = size;
1679 inarg.flags = flags;
1680 req->in.h.opcode = FUSE_SETXATTR;
1681 req->in.h.nodeid = get_node_id(inode);
1682 req->in.numargs = 3;
1683 req->in.args[0].size = sizeof(inarg);
1684 req->in.args[0].value = &inarg;
1685 req->in.args[1].size = strlen(name) + 1;
1686 req->in.args[1].value = name;
1687 req->in.args[2].size = size;
1688 req->in.args[2].value = value;
1689 fuse_request_send(fc, req);
1690 err = req->out.h.error;
1691 fuse_put_request(fc, req);
1692 if (err == -ENOSYS) {
1693 fc->no_setxattr = 1;
1694 err = -EOPNOTSUPP;
1695 }
1696 return err;
1697}
1698
1699static ssize_t fuse_getxattr(struct dentry *entry, const char *name,
1700 void *value, size_t size)
1701{
1702 struct inode *inode = entry->d_inode;
1703 struct fuse_conn *fc = get_fuse_conn(inode);
1704 struct fuse_req *req;
1705 struct fuse_getxattr_in inarg;
1706 struct fuse_getxattr_out outarg;
1707 ssize_t ret;
1708
1709 if (fc->no_getxattr)
1710 return -EOPNOTSUPP;
1711
1712 req = fuse_get_req(fc);
1713 if (IS_ERR(req))
1714 return PTR_ERR(req);
1715
1716 memset(&inarg, 0, sizeof(inarg));
1717 inarg.size = size;
1718 req->in.h.opcode = FUSE_GETXATTR;
1719 req->in.h.nodeid = get_node_id(inode);
1720 req->in.numargs = 2;
1721 req->in.args[0].size = sizeof(inarg);
1722 req->in.args[0].value = &inarg;
1723 req->in.args[1].size = strlen(name) + 1;
1724 req->in.args[1].value = name;
1725 /* This is really two different operations rolled into one */
1726 req->out.numargs = 1;
1727 if (size) {
1728 req->out.argvar = 1;
1729 req->out.args[0].size = size;
1730 req->out.args[0].value = value;
1731 } else {
1732 req->out.args[0].size = sizeof(outarg);
1733 req->out.args[0].value = &outarg;
1734 }
1735 fuse_request_send(fc, req);
1736 ret = req->out.h.error;
1737 if (!ret)
1738 ret = size ? req->out.args[0].size : outarg.size;
1739 else {
1740 if (ret == -ENOSYS) {
1741 fc->no_getxattr = 1;
1742 ret = -EOPNOTSUPP;
1743 }
1744 }
1745 fuse_put_request(fc, req);
1746 return ret;
1747}
1748
1749static ssize_t fuse_listxattr(struct dentry *entry, char *list, size_t size)
1750{
1751 struct inode *inode = entry->d_inode;
1752 struct fuse_conn *fc = get_fuse_conn(inode);
1753 struct fuse_req *req;
1754 struct fuse_getxattr_in inarg;
1755 struct fuse_getxattr_out outarg;
1756 ssize_t ret;
1757
1758 if (!fuse_allow_task(fc, current))
1759 return -EACCES;
1760
1761 if (fc->no_listxattr)
1762 return -EOPNOTSUPP;
1763
1764 req = fuse_get_req(fc);
1765 if (IS_ERR(req))
1766 return PTR_ERR(req);
1767
1768 memset(&inarg, 0, sizeof(inarg));
1769 inarg.size = size;
1770 req->in.h.opcode = FUSE_LISTXATTR;
1771 req->in.h.nodeid = get_node_id(inode);
1772 req->in.numargs = 1;
1773 req->in.args[0].size = sizeof(inarg);
1774 req->in.args[0].value = &inarg;
1775 /* This is really two different operations rolled into one */
1776 req->out.numargs = 1;
1777 if (size) {
1778 req->out.argvar = 1;
1779 req->out.args[0].size = size;
1780 req->out.args[0].value = list;
1781 } else {
1782 req->out.args[0].size = sizeof(outarg);
1783 req->out.args[0].value = &outarg;
1784 }
1785 fuse_request_send(fc, req);
1786 ret = req->out.h.error;
1787 if (!ret)
1788 ret = size ? req->out.args[0].size : outarg.size;
1789 else {
1790 if (ret == -ENOSYS) {
1791 fc->no_listxattr = 1;
1792 ret = -EOPNOTSUPP;
1793 }
1794 }
1795 fuse_put_request(fc, req);
1796 return ret;
1797}
1798
1799static int fuse_removexattr(struct dentry *entry, const char *name)
1800{
1801 struct inode *inode = entry->d_inode;
1802 struct fuse_conn *fc = get_fuse_conn(inode);
1803 struct fuse_req *req;
1804 int err;
1805
1806 if (fc->no_removexattr)
1807 return -EOPNOTSUPP;
1808
1809 req = fuse_get_req(fc);
1810 if (IS_ERR(req))
1811 return PTR_ERR(req);
1812
1813 req->in.h.opcode = FUSE_REMOVEXATTR;
1814 req->in.h.nodeid = get_node_id(inode);
1815 req->in.numargs = 1;
1816 req->in.args[0].size = strlen(name) + 1;
1817 req->in.args[0].value = name;
1818 fuse_request_send(fc, req);
1819 err = req->out.h.error;
1820 fuse_put_request(fc, req);
1821 if (err == -ENOSYS) {
1822 fc->no_removexattr = 1;
1823 err = -EOPNOTSUPP;
1824 }
1825 return err;
1826}
1827
1828static const struct inode_operations fuse_dir_inode_operations = {
1829 .lookup = fuse_lookup,
1830 .mkdir = fuse_mkdir,
1831 .symlink = fuse_symlink,
1832 .unlink = fuse_unlink,
1833 .rmdir = fuse_rmdir,
1834 .rename = fuse_rename,
1835 .link = fuse_link,
1836 .setattr = fuse_setattr,
1837 .create = fuse_create,
1838 .atomic_open = fuse_atomic_open,
1839 .mknod = fuse_mknod,
1840 .permission = fuse_permission,
1841 .getattr = fuse_getattr,
1842 .setxattr = fuse_setxattr,
1843 .getxattr = fuse_getxattr,
1844 .listxattr = fuse_listxattr,
1845 .removexattr = fuse_removexattr,
1846};
1847
1848static const struct file_operations fuse_dir_operations = {
1849 .llseek = generic_file_llseek,
1850 .read = generic_read_dir,
1851 .readdir = fuse_readdir,
1852 .open = fuse_dir_open,
1853 .release = fuse_dir_release,
1854 .fsync = fuse_dir_fsync,
1855 .unlocked_ioctl = fuse_dir_ioctl,
1856 .compat_ioctl = fuse_dir_compat_ioctl,
1857};
1858
1859static const struct inode_operations fuse_common_inode_operations = {
1860 .setattr = fuse_setattr,
1861 .permission = fuse_permission,
1862 .getattr = fuse_getattr,
1863 .setxattr = fuse_setxattr,
1864 .getxattr = fuse_getxattr,
1865 .listxattr = fuse_listxattr,
1866 .removexattr = fuse_removexattr,
1867};
1868
1869static const struct inode_operations fuse_symlink_inode_operations = {
1870 .setattr = fuse_setattr,
1871 .follow_link = fuse_follow_link,
1872 .put_link = fuse_put_link,
1873 .readlink = generic_readlink,
1874 .getattr = fuse_getattr,
1875 .setxattr = fuse_setxattr,
1876 .getxattr = fuse_getxattr,
1877 .listxattr = fuse_listxattr,
1878 .removexattr = fuse_removexattr,
1879};
1880
1881void fuse_init_common(struct inode *inode)
1882{
1883 inode->i_op = &fuse_common_inode_operations;
1884}
1885
1886void fuse_init_dir(struct inode *inode)
1887{
1888 inode->i_op = &fuse_dir_inode_operations;
1889 inode->i_fop = &fuse_dir_operations;
1890}
1891
1892void fuse_init_symlink(struct inode *inode)
1893{
1894 inode->i_op = &fuse_symlink_inode_operations;
1895}
Linux kernel - Deliverables
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