]> git.proxmox.com Git - mirror_ubuntu-kernels.git/blob - fs/fuse/dir.c
projects / mirror_ubuntu-kernels.git / blob
? search:
summary | shortlog | log | commit | commitdiff | tree
blame | history | raw | HEAD
Merge branches 'for-5.1/upstream-fixes', 'for-5.2/core', 'for-5.2/ish', 'for-5.2...
[mirror_ubuntu-kernels.git] / fs / fuse / dir.c
1 /*
2 FUSE: Filesystem in Userspace
3 Copyright (C) 2001-2008 Miklos Szeredi <miklos@szeredi.hu>
4
5 This program can be distributed under the terms of the GNU GPL.
6 See the file COPYING.
7 */
8
9 #include "fuse_i.h"
10
11 #include <linux/pagemap.h>
12 #include <linux/file.h>
13 #include <linux/sched.h>
14 #include <linux/namei.h>
15 #include <linux/slab.h>
16 #include <linux/xattr.h>
17 #include <linux/iversion.h>
18 #include <linux/posix_acl.h>
19
20 static void fuse_advise_use_readdirplus(struct inode *dir)
21 {
22 struct fuse_inode *fi = get_fuse_inode(dir);
23
24 set_bit(FUSE_I_ADVISE_RDPLUS, &fi->state);
25 }
26
27 union fuse_dentry {
28 u64 time;
29 struct rcu_head rcu;
30 };
31
32 static inline void fuse_dentry_settime(struct dentry *entry, u64 time)
33 {
34 ((union fuse_dentry *) entry->d_fsdata)->time = time;
35 }
36
37 static inline u64 fuse_dentry_time(struct dentry *entry)
38 {
39 return ((union fuse_dentry *) entry->d_fsdata)->time;
40 }
41
42 /*
43 * FUSE caches dentries and attributes with separate timeout. The
44 * time in jiffies until the dentry/attributes are valid is stored in
45 * dentry->d_fsdata and fuse_inode->i_time respectively.
46 */
47
48 /*
49 * Calculate the time in jiffies until a dentry/attributes are valid
50 */
51 static u64 time_to_jiffies(u64 sec, u32 nsec)
52 {
53 if (sec || nsec) {
54 struct timespec64 ts = {
55 sec,
56 min_t(u32, nsec, NSEC_PER_SEC - 1)
57 };
58
59 return get_jiffies_64() + timespec64_to_jiffies(&ts);
60 } else
61 return 0;
62 }
63
64 /*
65 * Set dentry and possibly attribute timeouts from the lookup/mk*
66 * replies
67 */
68 void fuse_change_entry_timeout(struct dentry *entry, struct fuse_entry_out *o)
69 {
70 fuse_dentry_settime(entry,
71 time_to_jiffies(o->entry_valid, o->entry_valid_nsec));
72 }
73
74 static u64 attr_timeout(struct fuse_attr_out *o)
75 {
76 return time_to_jiffies(o->attr_valid, o->attr_valid_nsec);
77 }
78
79 u64 entry_attr_timeout(struct fuse_entry_out *o)
80 {
81 return time_to_jiffies(o->attr_valid, o->attr_valid_nsec);
82 }
83
84 static void fuse_invalidate_attr_mask(struct inode *inode, u32 mask)
85 {
86 set_mask_bits(&get_fuse_inode(inode)->inval_mask, 0, mask);
87 }
88
89 /*
90 * Mark the attributes as stale, so that at the next call to
91 * ->getattr() they will be fetched from userspace
92 */
93 void fuse_invalidate_attr(struct inode *inode)
94 {
95 fuse_invalidate_attr_mask(inode, STATX_BASIC_STATS);
96 }
97
98 static void fuse_dir_changed(struct inode *dir)
99 {
100 fuse_invalidate_attr(dir);
101 inode_maybe_inc_iversion(dir, false);
102 }
103
104 /**
105 * Mark the attributes as stale due to an atime change. Avoid the invalidate if
106 * atime is not used.
107 */
108 void fuse_invalidate_atime(struct inode *inode)
109 {
110 if (!IS_RDONLY(inode))
111 fuse_invalidate_attr_mask(inode, STATX_ATIME);
112 }
113
114 /*
115 * Just mark the entry as stale, so that a next attempt to look it up
116 * will result in a new lookup call to userspace
117 *
118 * This is called when a dentry is about to become negative and the
119 * timeout is unknown (unlink, rmdir, rename and in some cases
120 * lookup)
121 */
122 void fuse_invalidate_entry_cache(struct dentry *entry)
123 {
124 fuse_dentry_settime(entry, 0);
125 }
126
127 /*
128 * Same as fuse_invalidate_entry_cache(), but also try to remove the
129 * dentry from the hash
130 */
131 static void fuse_invalidate_entry(struct dentry *entry)
132 {
133 d_invalidate(entry);
134 fuse_invalidate_entry_cache(entry);
135 }
136
137 static void fuse_lookup_init(struct fuse_conn *fc, struct fuse_args *args,
138 u64 nodeid, const struct qstr *name,
139 struct fuse_entry_out *outarg)
140 {
141 memset(outarg, 0, sizeof(struct fuse_entry_out));
142 args->in.h.opcode = FUSE_LOOKUP;
143 args->in.h.nodeid = nodeid;
144 args->in.numargs = 1;
145 args->in.args[0].size = name->len + 1;
146 args->in.args[0].value = name->name;
147 args->out.numargs = 1;
148 args->out.args[0].size = sizeof(struct fuse_entry_out);
149 args->out.args[0].value = outarg;
150 }
151
152 /*
153 * Check whether the dentry is still valid
154 *
155 * If the entry validity timeout has expired and the dentry is
156 * positive, try to redo the lookup. If the lookup results in a
157 * different inode, then let the VFS invalidate the dentry and redo
158 * the lookup once more. If the lookup results in the same inode,
159 * then refresh the attributes, timeouts and mark the dentry valid.
160 */
161 static int fuse_dentry_revalidate(struct dentry *entry, unsigned int flags)
162 {
163 struct inode *inode;
164 struct dentry *parent;
165 struct fuse_conn *fc;
166 struct fuse_inode *fi;
167 int ret;
168
169 inode = d_inode_rcu(entry);
170 if (inode && is_bad_inode(inode))
171 goto invalid;
172 else if (time_before64(fuse_dentry_time(entry), get_jiffies_64()) ||
173 (flags & LOOKUP_REVAL)) {
174 struct fuse_entry_out outarg;
175 FUSE_ARGS(args);
176 struct fuse_forget_link *forget;
177 u64 attr_version;
178
179 /* For negative dentries, always do a fresh lookup */
180 if (!inode)
181 goto invalid;
182
183 ret = -ECHILD;
184 if (flags & LOOKUP_RCU)
185 goto out;
186
187 fc = get_fuse_conn(inode);
188
189 forget = fuse_alloc_forget();
190 ret = -ENOMEM;
191 if (!forget)
192 goto out;
193
194 attr_version = fuse_get_attr_version(fc);
195
196 parent = dget_parent(entry);
197 fuse_lookup_init(fc, &args, get_node_id(d_inode(parent)),
198 &entry->d_name, &outarg);
199 ret = fuse_simple_request(fc, &args);
200 dput(parent);
201 /* Zero nodeid is same as -ENOENT */
202 if (!ret && !outarg.nodeid)
203 ret = -ENOENT;
204 if (!ret) {
205 fi = get_fuse_inode(inode);
206 if (outarg.nodeid != get_node_id(inode)) {
207 fuse_queue_forget(fc, forget, outarg.nodeid, 1);
208 goto invalid;
209 }
210 spin_lock(&fi->lock);
211 fi->nlookup++;
212 spin_unlock(&fi->lock);
213 }
214 kfree(forget);
215 if (ret == -ENOMEM)
216 goto out;
217 if (ret || (outarg.attr.mode ^ inode->i_mode) & S_IFMT)
218 goto invalid;
219
220 forget_all_cached_acls(inode);
221 fuse_change_attributes(inode, &outarg.attr,
222 entry_attr_timeout(&outarg),
223 attr_version);
224 fuse_change_entry_timeout(entry, &outarg);
225 } else if (inode) {
226 fi = get_fuse_inode(inode);
227 if (flags & LOOKUP_RCU) {
228 if (test_bit(FUSE_I_INIT_RDPLUS, &fi->state))
229 return -ECHILD;
230 } else if (test_and_clear_bit(FUSE_I_INIT_RDPLUS, &fi->state)) {
231 parent = dget_parent(entry);
232 fuse_advise_use_readdirplus(d_inode(parent));
233 dput(parent);
234 }
235 }
236 ret = 1;
237 out:
238 return ret;
239
240 invalid:
241 ret = 0;
242 goto out;
243 }
244
245 static int fuse_dentry_init(struct dentry *dentry)
246 {
247 dentry->d_fsdata = kzalloc(sizeof(union fuse_dentry), GFP_KERNEL);
248
249 return dentry->d_fsdata ? 0 : -ENOMEM;
250 }
251 static void fuse_dentry_release(struct dentry *dentry)
252 {
253 union fuse_dentry *fd = dentry->d_fsdata;
254
255 kfree_rcu(fd, rcu);
256 }
257
258 const struct dentry_operations fuse_dentry_operations = {
259 .d_revalidate = fuse_dentry_revalidate,
260 .d_init = fuse_dentry_init,
261 .d_release = fuse_dentry_release,
262 };
263
264 const struct dentry_operations fuse_root_dentry_operations = {
265 .d_init = fuse_dentry_init,
266 .d_release = fuse_dentry_release,
267 };
268
269 int fuse_valid_type(int m)
270 {
271 return S_ISREG(m) || S_ISDIR(m) || S_ISLNK(m) || S_ISCHR(m) ||
272 S_ISBLK(m) || S_ISFIFO(m) || S_ISSOCK(m);
273 }
274
275 int fuse_lookup_name(struct super_block *sb, u64 nodeid, const struct qstr *name,
276 struct fuse_entry_out *outarg, struct inode **inode)
277 {
278 struct fuse_conn *fc = get_fuse_conn_super(sb);
279 FUSE_ARGS(args);
280 struct fuse_forget_link *forget;
281 u64 attr_version;
282 int err;
283
284 *inode = NULL;
285 err = -ENAMETOOLONG;
286 if (name->len > FUSE_NAME_MAX)
287 goto out;
288
289
290 forget = fuse_alloc_forget();
291 err = -ENOMEM;
292 if (!forget)
293 goto out;
294
295 attr_version = fuse_get_attr_version(fc);
296
297 fuse_lookup_init(fc, &args, nodeid, name, outarg);
298 err = fuse_simple_request(fc, &args);
299 /* Zero nodeid is same as -ENOENT, but with valid timeout */
300 if (err || !outarg->nodeid)
301 goto out_put_forget;
302
303 err = -EIO;
304 if (!outarg->nodeid)
305 goto out_put_forget;
306 if (!fuse_valid_type(outarg->attr.mode))
307 goto out_put_forget;
308
309 *inode = fuse_iget(sb, outarg->nodeid, outarg->generation,
310 &outarg->attr, entry_attr_timeout(outarg),
311 attr_version);
312 err = -ENOMEM;
313 if (!*inode) {
314 fuse_queue_forget(fc, forget, outarg->nodeid, 1);
315 goto out;
316 }
317 err = 0;
318
319 out_put_forget:
320 kfree(forget);
321 out:
322 return err;
323 }
324
325 static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry,
326 unsigned int flags)
327 {
328 int err;
329 struct fuse_entry_out outarg;
330 struct inode *inode;
331 struct dentry *newent;
332 bool outarg_valid = true;
333 bool locked;
334
335 locked = fuse_lock_inode(dir);
336 err = fuse_lookup_name(dir->i_sb, get_node_id(dir), &entry->d_name,
337 &outarg, &inode);
338 fuse_unlock_inode(dir, locked);
339 if (err == -ENOENT) {
340 outarg_valid = false;
341 err = 0;
342 }
343 if (err)
344 goto out_err;
345
346 err = -EIO;
347 if (inode && get_node_id(inode) == FUSE_ROOT_ID)
348 goto out_iput;
349
350 newent = d_splice_alias(inode, entry);
351 err = PTR_ERR(newent);
352 if (IS_ERR(newent))
353 goto out_err;
354
355 entry = newent ? newent : entry;
356 if (outarg_valid)
357 fuse_change_entry_timeout(entry, &outarg);
358 else
359 fuse_invalidate_entry_cache(entry);
360
361 fuse_advise_use_readdirplus(dir);
362 return newent;
363
364 out_iput:
365 iput(inode);
366 out_err:
367 return ERR_PTR(err);
368 }
369
370 /*
371 * Atomic create+open operation
372 *
373 * If the filesystem doesn't support this, then fall back to separate
374 * 'mknod' + 'open' requests.
375 */
376 static int fuse_create_open(struct inode *dir, struct dentry *entry,
377 struct file *file, unsigned flags,
378 umode_t mode)
379 {
380 int err;
381 struct inode *inode;
382 struct fuse_conn *fc = get_fuse_conn(dir);
383 FUSE_ARGS(args);
384 struct fuse_forget_link *forget;
385 struct fuse_create_in inarg;
386 struct fuse_open_out outopen;
387 struct fuse_entry_out outentry;
388 struct fuse_inode *fi;
389 struct fuse_file *ff;
390
391 /* Userspace expects S_IFREG in create mode */
392 BUG_ON((mode & S_IFMT) != S_IFREG);
393
394 forget = fuse_alloc_forget();
395 err = -ENOMEM;
396 if (!forget)
397 goto out_err;
398
399 err = -ENOMEM;
400 ff = fuse_file_alloc(fc);
401 if (!ff)
402 goto out_put_forget_req;
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 args.in.h.opcode = FUSE_CREATE;
414 args.in.h.nodeid = get_node_id(dir);
415 args.in.numargs = 2;
416 args.in.args[0].size = sizeof(inarg);
417 args.in.args[0].value = &inarg;
418 args.in.args[1].size = entry->d_name.len + 1;
419 args.in.args[1].value = entry->d_name.name;
420 args.out.numargs = 2;
421 args.out.args[0].size = sizeof(outentry);
422 args.out.args[0].value = &outentry;
423 args.out.args[1].size = sizeof(outopen);
424 args.out.args[1].value = &outopen;
425 err = fuse_simple_request(fc, &args);
426 if (err)
427 goto out_free_ff;
428
429 err = -EIO;
430 if (!S_ISREG(outentry.attr.mode) || invalid_nodeid(outentry.nodeid))
431 goto out_free_ff;
432
433 ff->fh = outopen.fh;
434 ff->nodeid = outentry.nodeid;
435 ff->open_flags = outopen.open_flags;
436 inode = fuse_iget(dir->i_sb, outentry.nodeid, outentry.generation,
437 &outentry.attr, entry_attr_timeout(&outentry), 0);
438 if (!inode) {
439 flags &= ~(O_CREAT | O_EXCL | O_TRUNC);
440 fuse_sync_release(NULL, ff, flags);
441 fuse_queue_forget(fc, forget, outentry.nodeid, 1);
442 err = -ENOMEM;
443 goto out_err;
444 }
445 kfree(forget);
446 d_instantiate(entry, inode);
447 fuse_change_entry_timeout(entry, &outentry);
448 fuse_dir_changed(dir);
449 err = finish_open(file, entry, generic_file_open);
450 if (err) {
451 fi = get_fuse_inode(inode);
452 fuse_sync_release(fi, ff, flags);
453 } else {
454 file->private_data = ff;
455 fuse_finish_open(inode, file);
456 }
457 return err;
458
459 out_free_ff:
460 fuse_file_free(ff);
461 out_put_forget_req:
462 kfree(forget);
463 out_err:
464 return err;
465 }
466
467 static int fuse_mknod(struct inode *, struct dentry *, umode_t, dev_t);
468 static int fuse_atomic_open(struct inode *dir, struct dentry *entry,
469 struct file *file, unsigned flags,
470 umode_t mode)
471 {
472 int err;
473 struct fuse_conn *fc = get_fuse_conn(dir);
474 struct dentry *res = NULL;
475
476 if (d_in_lookup(entry)) {
477 res = fuse_lookup(dir, entry, 0);
478 if (IS_ERR(res))
479 return PTR_ERR(res);
480
481 if (res)
482 entry = res;
483 }
484
485 if (!(flags & O_CREAT) || d_really_is_positive(entry))
486 goto no_open;
487
488 /* Only creates */
489 file->f_mode |= FMODE_CREATED;
490
491 if (fc->no_create)
492 goto mknod;
493
494 err = fuse_create_open(dir, entry, file, flags, mode);
495 if (err == -ENOSYS) {
496 fc->no_create = 1;
497 goto mknod;
498 }
499 out_dput:
500 dput(res);
501 return err;
502
503 mknod:
504 err = fuse_mknod(dir, entry, mode, 0);
505 if (err)
506 goto out_dput;
507 no_open:
508 return finish_no_open(file, res);
509 }
510
511 /*
512 * Code shared between mknod, mkdir, symlink and link
513 */
514 static int create_new_entry(struct fuse_conn *fc, struct fuse_args *args,
515 struct inode *dir, struct dentry *entry,
516 umode_t mode)
517 {
518 struct fuse_entry_out outarg;
519 struct inode *inode;
520 struct dentry *d;
521 int err;
522 struct fuse_forget_link *forget;
523
524 forget = fuse_alloc_forget();
525 if (!forget)
526 return -ENOMEM;
527
528 memset(&outarg, 0, sizeof(outarg));
529 args->in.h.nodeid = get_node_id(dir);
530 args->out.numargs = 1;
531 args->out.args[0].size = sizeof(outarg);
532 args->out.args[0].value = &outarg;
533 err = fuse_simple_request(fc, args);
534 if (err)
535 goto out_put_forget_req;
536
537 err = -EIO;
538 if (invalid_nodeid(outarg.nodeid))
539 goto out_put_forget_req;
540
541 if ((outarg.attr.mode ^ mode) & S_IFMT)
542 goto out_put_forget_req;
543
544 inode = fuse_iget(dir->i_sb, outarg.nodeid, outarg.generation,
545 &outarg.attr, entry_attr_timeout(&outarg), 0);
546 if (!inode) {
547 fuse_queue_forget(fc, forget, outarg.nodeid, 1);
548 return -ENOMEM;
549 }
550 kfree(forget);
551
552 d_drop(entry);
553 d = d_splice_alias(inode, entry);
554 if (IS_ERR(d))
555 return PTR_ERR(d);
556
557 if (d) {
558 fuse_change_entry_timeout(d, &outarg);
559 dput(d);
560 } else {
561 fuse_change_entry_timeout(entry, &outarg);
562 }
563 fuse_dir_changed(dir);
564 return 0;
565
566 out_put_forget_req:
567 kfree(forget);
568 return err;
569 }
570
571 static int fuse_mknod(struct inode *dir, struct dentry *entry, umode_t mode,
572 dev_t rdev)
573 {
574 struct fuse_mknod_in inarg;
575 struct fuse_conn *fc = get_fuse_conn(dir);
576 FUSE_ARGS(args);
577
578 if (!fc->dont_mask)
579 mode &= ~current_umask();
580
581 memset(&inarg, 0, sizeof(inarg));
582 inarg.mode = mode;
583 inarg.rdev = new_encode_dev(rdev);
584 inarg.umask = current_umask();
585 args.in.h.opcode = FUSE_MKNOD;
586 args.in.numargs = 2;
587 args.in.args[0].size = sizeof(inarg);
588 args.in.args[0].value = &inarg;
589 args.in.args[1].size = entry->d_name.len + 1;
590 args.in.args[1].value = entry->d_name.name;
591 return create_new_entry(fc, &args, dir, entry, mode);
592 }
593
594 static int fuse_create(struct inode *dir, struct dentry *entry, umode_t mode,
595 bool excl)
596 {
597 return fuse_mknod(dir, entry, mode, 0);
598 }
599
600 static int fuse_mkdir(struct inode *dir, struct dentry *entry, umode_t mode)
601 {
602 struct fuse_mkdir_in inarg;
603 struct fuse_conn *fc = get_fuse_conn(dir);
604 FUSE_ARGS(args);
605
606 if (!fc->dont_mask)
607 mode &= ~current_umask();
608
609 memset(&inarg, 0, sizeof(inarg));
610 inarg.mode = mode;
611 inarg.umask = current_umask();
612 args.in.h.opcode = FUSE_MKDIR;
613 args.in.numargs = 2;
614 args.in.args[0].size = sizeof(inarg);
615 args.in.args[0].value = &inarg;
616 args.in.args[1].size = entry->d_name.len + 1;
617 args.in.args[1].value = entry->d_name.name;
618 return create_new_entry(fc, &args, dir, entry, S_IFDIR);
619 }
620
621 static int fuse_symlink(struct inode *dir, struct dentry *entry,
622 const char *link)
623 {
624 struct fuse_conn *fc = get_fuse_conn(dir);
625 unsigned len = strlen(link) + 1;
626 FUSE_ARGS(args);
627
628 args.in.h.opcode = FUSE_SYMLINK;
629 args.in.numargs = 2;
630 args.in.args[0].size = entry->d_name.len + 1;
631 args.in.args[0].value = entry->d_name.name;
632 args.in.args[1].size = len;
633 args.in.args[1].value = link;
634 return create_new_entry(fc, &args, dir, entry, S_IFLNK);
635 }
636
637 void fuse_update_ctime(struct inode *inode)
638 {
639 if (!IS_NOCMTIME(inode)) {
640 inode->i_ctime = current_time(inode);
641 mark_inode_dirty_sync(inode);
642 }
643 }
644
645 static int fuse_unlink(struct inode *dir, struct dentry *entry)
646 {
647 int err;
648 struct fuse_conn *fc = get_fuse_conn(dir);
649 FUSE_ARGS(args);
650
651 args.in.h.opcode = FUSE_UNLINK;
652 args.in.h.nodeid = get_node_id(dir);
653 args.in.numargs = 1;
654 args.in.args[0].size = entry->d_name.len + 1;
655 args.in.args[0].value = entry->d_name.name;
656 err = fuse_simple_request(fc, &args);
657 if (!err) {
658 struct inode *inode = d_inode(entry);
659 struct fuse_inode *fi = get_fuse_inode(inode);
660
661 spin_lock(&fi->lock);
662 fi->attr_version = atomic64_inc_return(&fc->attr_version);
663 /*
664 * If i_nlink == 0 then unlink doesn't make sense, yet this can
665 * happen if userspace filesystem is careless. It would be
666 * difficult to enforce correct nlink usage so just ignore this
667 * condition here
668 */
669 if (inode->i_nlink > 0)
670 drop_nlink(inode);
671 spin_unlock(&fi->lock);
672 fuse_invalidate_attr(inode);
673 fuse_dir_changed(dir);
674 fuse_invalidate_entry_cache(entry);
675 fuse_update_ctime(inode);
676 } else if (err == -EINTR)
677 fuse_invalidate_entry(entry);
678 return err;
679 }
680
681 static int fuse_rmdir(struct inode *dir, struct dentry *entry)
682 {
683 int err;
684 struct fuse_conn *fc = get_fuse_conn(dir);
685 FUSE_ARGS(args);
686
687 args.in.h.opcode = FUSE_RMDIR;
688 args.in.h.nodeid = get_node_id(dir);
689 args.in.numargs = 1;
690 args.in.args[0].size = entry->d_name.len + 1;
691 args.in.args[0].value = entry->d_name.name;
692 err = fuse_simple_request(fc, &args);
693 if (!err) {
694 clear_nlink(d_inode(entry));
695 fuse_dir_changed(dir);
696 fuse_invalidate_entry_cache(entry);
697 } else if (err == -EINTR)
698 fuse_invalidate_entry(entry);
699 return err;
700 }
701
702 static int fuse_rename_common(struct inode *olddir, struct dentry *oldent,
703 struct inode *newdir, struct dentry *newent,
704 unsigned int flags, int opcode, size_t argsize)
705 {
706 int err;
707 struct fuse_rename2_in inarg;
708 struct fuse_conn *fc = get_fuse_conn(olddir);
709 FUSE_ARGS(args);
710
711 memset(&inarg, 0, argsize);
712 inarg.newdir = get_node_id(newdir);
713 inarg.flags = flags;
714 args.in.h.opcode = opcode;
715 args.in.h.nodeid = get_node_id(olddir);
716 args.in.numargs = 3;
717 args.in.args[0].size = argsize;
718 args.in.args[0].value = &inarg;
719 args.in.args[1].size = oldent->d_name.len + 1;
720 args.in.args[1].value = oldent->d_name.name;
721 args.in.args[2].size = newent->d_name.len + 1;
722 args.in.args[2].value = newent->d_name.name;
723 err = fuse_simple_request(fc, &args);
724 if (!err) {
725 /* ctime changes */
726 fuse_invalidate_attr(d_inode(oldent));
727 fuse_update_ctime(d_inode(oldent));
728
729 if (flags & RENAME_EXCHANGE) {
730 fuse_invalidate_attr(d_inode(newent));
731 fuse_update_ctime(d_inode(newent));
732 }
733
734 fuse_dir_changed(olddir);
735 if (olddir != newdir)
736 fuse_dir_changed(newdir);
737
738 /* newent will end up negative */
739 if (!(flags & RENAME_EXCHANGE) && d_really_is_positive(newent)) {
740 fuse_invalidate_attr(d_inode(newent));
741 fuse_invalidate_entry_cache(newent);
742 fuse_update_ctime(d_inode(newent));
743 }
744 } else if (err == -EINTR) {
745 /* If request was interrupted, DEITY only knows if the
746 rename actually took place. If the invalidation
747 fails (e.g. some process has CWD under the renamed
748 directory), then there can be inconsistency between
749 the dcache and the real filesystem. Tough luck. */
750 fuse_invalidate_entry(oldent);
751 if (d_really_is_positive(newent))
752 fuse_invalidate_entry(newent);
753 }
754
755 return err;
756 }
757
758 static int fuse_rename2(struct inode *olddir, struct dentry *oldent,
759 struct inode *newdir, struct dentry *newent,
760 unsigned int flags)
761 {
762 struct fuse_conn *fc = get_fuse_conn(olddir);
763 int err;
764
765 if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE))
766 return -EINVAL;
767
768 if (flags) {
769 if (fc->no_rename2 || fc->minor < 23)
770 return -EINVAL;
771
772 err = fuse_rename_common(olddir, oldent, newdir, newent, flags,
773 FUSE_RENAME2,
774 sizeof(struct fuse_rename2_in));
775 if (err == -ENOSYS) {
776 fc->no_rename2 = 1;
777 err = -EINVAL;
778 }
779 } else {
780 err = fuse_rename_common(olddir, oldent, newdir, newent, 0,
781 FUSE_RENAME,
782 sizeof(struct fuse_rename_in));
783 }
784
785 return err;
786 }
787
788 static int fuse_link(struct dentry *entry, struct inode *newdir,
789 struct dentry *newent)
790 {
791 int err;
792 struct fuse_link_in inarg;
793 struct inode *inode = d_inode(entry);
794 struct fuse_conn *fc = get_fuse_conn(inode);
795 FUSE_ARGS(args);
796
797 memset(&inarg, 0, sizeof(inarg));
798 inarg.oldnodeid = get_node_id(inode);
799 args.in.h.opcode = FUSE_LINK;
800 args.in.numargs = 2;
801 args.in.args[0].size = sizeof(inarg);
802 args.in.args[0].value = &inarg;
803 args.in.args[1].size = newent->d_name.len + 1;
804 args.in.args[1].value = newent->d_name.name;
805 err = create_new_entry(fc, &args, newdir, newent, inode->i_mode);
806 /* Contrary to "normal" filesystems it can happen that link
807 makes two "logical" inodes point to the same "physical"
808 inode. We invalidate the attributes of the old one, so it
809 will reflect changes in the backing inode (link count,
810 etc.)
811 */
812 if (!err) {
813 struct fuse_inode *fi = get_fuse_inode(inode);
814
815 spin_lock(&fi->lock);
816 fi->attr_version = atomic64_inc_return(&fc->attr_version);
817 inc_nlink(inode);
818 spin_unlock(&fi->lock);
819 fuse_invalidate_attr(inode);
820 fuse_update_ctime(inode);
821 } else if (err == -EINTR) {
822 fuse_invalidate_attr(inode);
823 }
824 return err;
825 }
826
827 static void fuse_fillattr(struct inode *inode, struct fuse_attr *attr,
828 struct kstat *stat)
829 {
830 unsigned int blkbits;
831 struct fuse_conn *fc = get_fuse_conn(inode);
832
833 /* see the comment in fuse_change_attributes() */
834 if (fc->writeback_cache && S_ISREG(inode->i_mode)) {
835 attr->size = i_size_read(inode);
836 attr->mtime = inode->i_mtime.tv_sec;
837 attr->mtimensec = inode->i_mtime.tv_nsec;
838 attr->ctime = inode->i_ctime.tv_sec;
839 attr->ctimensec = inode->i_ctime.tv_nsec;
840 }
841
842 stat->dev = inode->i_sb->s_dev;
843 stat->ino = attr->ino;
844 stat->mode = (inode->i_mode & S_IFMT) | (attr->mode & 07777);
845 stat->nlink = attr->nlink;
846 stat->uid = make_kuid(fc->user_ns, attr->uid);
847 stat->gid = make_kgid(fc->user_ns, attr->gid);
848 stat->rdev = inode->i_rdev;
849 stat->atime.tv_sec = attr->atime;
850 stat->atime.tv_nsec = attr->atimensec;
851 stat->mtime.tv_sec = attr->mtime;
852 stat->mtime.tv_nsec = attr->mtimensec;
853 stat->ctime.tv_sec = attr->ctime;
854 stat->ctime.tv_nsec = attr->ctimensec;
855 stat->size = attr->size;
856 stat->blocks = attr->blocks;
857
858 if (attr->blksize != 0)
859 blkbits = ilog2(attr->blksize);
860 else
861 blkbits = inode->i_sb->s_blocksize_bits;
862
863 stat->blksize = 1 << blkbits;
864 }
865
866 static int fuse_do_getattr(struct inode *inode, struct kstat *stat,
867 struct file *file)
868 {
869 int err;
870 struct fuse_getattr_in inarg;
871 struct fuse_attr_out outarg;
872 struct fuse_conn *fc = get_fuse_conn(inode);
873 FUSE_ARGS(args);
874 u64 attr_version;
875
876 attr_version = fuse_get_attr_version(fc);
877
878 memset(&inarg, 0, sizeof(inarg));
879 memset(&outarg, 0, sizeof(outarg));
880 /* Directories have separate file-handle space */
881 if (file && S_ISREG(inode->i_mode)) {
882 struct fuse_file *ff = file->private_data;
883
884 inarg.getattr_flags |= FUSE_GETATTR_FH;
885 inarg.fh = ff->fh;
886 }
887 args.in.h.opcode = FUSE_GETATTR;
888 args.in.h.nodeid = get_node_id(inode);
889 args.in.numargs = 1;
890 args.in.args[0].size = sizeof(inarg);
891 args.in.args[0].value = &inarg;
892 args.out.numargs = 1;
893 args.out.args[0].size = sizeof(outarg);
894 args.out.args[0].value = &outarg;
895 err = fuse_simple_request(fc, &args);
896 if (!err) {
897 if ((inode->i_mode ^ outarg.attr.mode) & S_IFMT) {
898 make_bad_inode(inode);
899 err = -EIO;
900 } else {
901 fuse_change_attributes(inode, &outarg.attr,
902 attr_timeout(&outarg),
903 attr_version);
904 if (stat)
905 fuse_fillattr(inode, &outarg.attr, stat);
906 }
907 }
908 return err;
909 }
910
911 static int fuse_update_get_attr(struct inode *inode, struct file *file,
912 struct kstat *stat, u32 request_mask,
913 unsigned int flags)
914 {
915 struct fuse_inode *fi = get_fuse_inode(inode);
916 int err = 0;
917 bool sync;
918
919 if (flags & AT_STATX_FORCE_SYNC)
920 sync = true;
921 else if (flags & AT_STATX_DONT_SYNC)
922 sync = false;
923 else if (request_mask & READ_ONCE(fi->inval_mask))
924 sync = true;
925 else
926 sync = time_before64(fi->i_time, get_jiffies_64());
927
928 if (sync) {
929 forget_all_cached_acls(inode);
930 err = fuse_do_getattr(inode, stat, file);
931 } else if (stat) {
932 generic_fillattr(inode, stat);
933 stat->mode = fi->orig_i_mode;
934 stat->ino = fi->orig_ino;
935 }
936
937 return err;
938 }
939
940 int fuse_update_attributes(struct inode *inode, struct file *file)
941 {
942 /* Do *not* need to get atime for internal purposes */
943 return fuse_update_get_attr(inode, file, NULL,
944 STATX_BASIC_STATS & ~STATX_ATIME, 0);
945 }
946
947 int fuse_reverse_inval_entry(struct super_block *sb, u64 parent_nodeid,
948 u64 child_nodeid, struct qstr *name)
949 {
950 int err = -ENOTDIR;
951 struct inode *parent;
952 struct dentry *dir;
953 struct dentry *entry;
954
955 parent = ilookup5(sb, parent_nodeid, fuse_inode_eq, &parent_nodeid);
956 if (!parent)
957 return -ENOENT;
958
959 inode_lock(parent);
960 if (!S_ISDIR(parent->i_mode))
961 goto unlock;
962
963 err = -ENOENT;
964 dir = d_find_alias(parent);
965 if (!dir)
966 goto unlock;
967
968 name->hash = full_name_hash(dir, name->name, name->len);
969 entry = d_lookup(dir, name);
970 dput(dir);
971 if (!entry)
972 goto unlock;
973
974 fuse_dir_changed(parent);
975 fuse_invalidate_entry(entry);
976
977 if (child_nodeid != 0 && d_really_is_positive(entry)) {
978 inode_lock(d_inode(entry));
979 if (get_node_id(d_inode(entry)) != child_nodeid) {
980 err = -ENOENT;
981 goto badentry;
982 }
983 if (d_mountpoint(entry)) {
984 err = -EBUSY;
985 goto badentry;
986 }
987 if (d_is_dir(entry)) {
988 shrink_dcache_parent(entry);
989 if (!simple_empty(entry)) {
990 err = -ENOTEMPTY;
991 goto badentry;
992 }
993 d_inode(entry)->i_flags |= S_DEAD;
994 }
995 dont_mount(entry);
996 clear_nlink(d_inode(entry));
997 err = 0;
998 badentry:
999 inode_unlock(d_inode(entry));
1000 if (!err)
1001 d_delete(entry);
1002 } else {
1003 err = 0;
1004 }
1005 dput(entry);
1006
1007 unlock:
1008 inode_unlock(parent);
1009 iput(parent);
1010 return err;
1011 }
1012
1013 /*
1014 * Calling into a user-controlled filesystem gives the filesystem
1015 * daemon ptrace-like capabilities over the current process. This
1016 * means, that the filesystem daemon is able to record the exact
1017 * filesystem operations performed, and can also control the behavior
1018 * of the requester process in otherwise impossible ways. For example
1019 * it can delay the operation for arbitrary length of time allowing
1020 * DoS against the requester.
1021 *
1022 * For this reason only those processes can call into the filesystem,
1023 * for which the owner of the mount has ptrace privilege. This
1024 * excludes processes started by other users, suid or sgid processes.
1025 */
1026 int fuse_allow_current_process(struct fuse_conn *fc)
1027 {
1028 const struct cred *cred;
1029
1030 if (fc->allow_other)
1031 return current_in_userns(fc->user_ns);
1032
1033 cred = current_cred();
1034 if (uid_eq(cred->euid, fc->user_id) &&
1035 uid_eq(cred->suid, fc->user_id) &&
1036 uid_eq(cred->uid, fc->user_id) &&
1037 gid_eq(cred->egid, fc->group_id) &&
1038 gid_eq(cred->sgid, fc->group_id) &&
1039 gid_eq(cred->gid, fc->group_id))
1040 return 1;
1041
1042 return 0;
1043 }
1044
1045 static int fuse_access(struct inode *inode, int mask)
1046 {
1047 struct fuse_conn *fc = get_fuse_conn(inode);
1048 FUSE_ARGS(args);
1049 struct fuse_access_in inarg;
1050 int err;
1051
1052 BUG_ON(mask & MAY_NOT_BLOCK);
1053
1054 if (fc->no_access)
1055 return 0;
1056
1057 memset(&inarg, 0, sizeof(inarg));
1058 inarg.mask = mask & (MAY_READ | MAY_WRITE | MAY_EXEC);
1059 args.in.h.opcode = FUSE_ACCESS;
1060 args.in.h.nodeid = get_node_id(inode);
1061 args.in.numargs = 1;
1062 args.in.args[0].size = sizeof(inarg);
1063 args.in.args[0].value = &inarg;
1064 err = fuse_simple_request(fc, &args);
1065 if (err == -ENOSYS) {
1066 fc->no_access = 1;
1067 err = 0;
1068 }
1069 return err;
1070 }
1071
1072 static int fuse_perm_getattr(struct inode *inode, int mask)
1073 {
1074 if (mask & MAY_NOT_BLOCK)
1075 return -ECHILD;
1076
1077 forget_all_cached_acls(inode);
1078 return fuse_do_getattr(inode, NULL, NULL);
1079 }
1080
1081 /*
1082 * Check permission. The two basic access models of FUSE are:
1083 *
1084 * 1) Local access checking ('default_permissions' mount option) based
1085 * on file mode. This is the plain old disk filesystem permission
1086 * modell.
1087 *
1088 * 2) "Remote" access checking, where server is responsible for
1089 * checking permission in each inode operation. An exception to this
1090 * is if ->permission() was invoked from sys_access() in which case an
1091 * access request is sent. Execute permission is still checked
1092 * locally based on file mode.
1093 */
1094 static int fuse_permission(struct inode *inode, int mask)
1095 {
1096 struct fuse_conn *fc = get_fuse_conn(inode);
1097 bool refreshed = false;
1098 int err = 0;
1099
1100 if (!fuse_allow_current_process(fc))
1101 return -EACCES;
1102
1103 /*
1104 * If attributes are needed, refresh them before proceeding
1105 */
1106 if (fc->default_permissions ||
1107 ((mask & MAY_EXEC) && S_ISREG(inode->i_mode))) {
1108 struct fuse_inode *fi = get_fuse_inode(inode);
1109 u32 perm_mask = STATX_MODE | STATX_UID | STATX_GID;
1110
1111 if (perm_mask & READ_ONCE(fi->inval_mask) ||
1112 time_before64(fi->i_time, get_jiffies_64())) {
1113 refreshed = true;
1114
1115 err = fuse_perm_getattr(inode, mask);
1116 if (err)
1117 return err;
1118 }
1119 }
1120
1121 if (fc->default_permissions) {
1122 err = generic_permission(inode, mask);
1123
1124 /* If permission is denied, try to refresh file
1125 attributes. This is also needed, because the root
1126 node will at first have no permissions */
1127 if (err == -EACCES && !refreshed) {
1128 err = fuse_perm_getattr(inode, mask);
1129 if (!err)
1130 err = generic_permission(inode, mask);
1131 }
1132
1133 /* Note: the opposite of the above test does not
1134 exist. So if permissions are revoked this won't be
1135 noticed immediately, only after the attribute
1136 timeout has expired */
1137 } else if (mask & (MAY_ACCESS | MAY_CHDIR)) {
1138 err = fuse_access(inode, mask);
1139 } else if ((mask & MAY_EXEC) && S_ISREG(inode->i_mode)) {
1140 if (!(inode->i_mode & S_IXUGO)) {
1141 if (refreshed)
1142 return -EACCES;
1143
1144 err = fuse_perm_getattr(inode, mask);
1145 if (!err && !(inode->i_mode & S_IXUGO))
1146 return -EACCES;
1147 }
1148 }
1149 return err;
1150 }
1151
1152 static int fuse_readlink_page(struct inode *inode, struct page *page)
1153 {
1154 struct fuse_conn *fc = get_fuse_conn(inode);
1155 struct fuse_req *req;
1156 int err;
1157
1158 req = fuse_get_req(fc, 1);
1159 if (IS_ERR(req))
1160 return PTR_ERR(req);
1161
1162 req->out.page_zeroing = 1;
1163 req->out.argpages = 1;
1164 req->num_pages = 1;
1165 req->pages[0] = page;
1166 req->page_descs[0].length = PAGE_SIZE - 1;
1167 req->in.h.opcode = FUSE_READLINK;
1168 req->in.h.nodeid = get_node_id(inode);
1169 req->out.argvar = 1;
1170 req->out.numargs = 1;
1171 req->out.args[0].size = PAGE_SIZE - 1;
1172 fuse_request_send(fc, req);
1173 err = req->out.h.error;
1174
1175 if (!err) {
1176 char *link = page_address(page);
1177 size_t len = req->out.args[0].size;
1178
1179 BUG_ON(len >= PAGE_SIZE);
1180 link[len] = '\0';
1181 }
1182
1183 fuse_put_request(fc, req);
1184 fuse_invalidate_atime(inode);
1185
1186 return err;
1187 }
1188
1189 static const char *fuse_get_link(struct dentry *dentry, struct inode *inode,
1190 struct delayed_call *callback)
1191 {
1192 struct fuse_conn *fc = get_fuse_conn(inode);
1193 struct page *page;
1194 int err;
1195
1196 err = -EIO;
1197 if (is_bad_inode(inode))
1198 goto out_err;
1199
1200 if (fc->cache_symlinks)
1201 return page_get_link(dentry, inode, callback);
1202
1203 err = -ECHILD;
1204 if (!dentry)
1205 goto out_err;
1206
1207 page = alloc_page(GFP_KERNEL);
1208 err = -ENOMEM;
1209 if (!page)
1210 goto out_err;
1211
1212 err = fuse_readlink_page(inode, page);
1213 if (err) {
1214 __free_page(page);
1215 goto out_err;
1216 }
1217
1218 set_delayed_call(callback, page_put_link, page);
1219
1220 return page_address(page);
1221
1222 out_err:
1223 return ERR_PTR(err);
1224 }
1225
1226 static int fuse_dir_open(struct inode *inode, struct file *file)
1227 {
1228 return fuse_open_common(inode, file, true);
1229 }
1230
1231 static int fuse_dir_release(struct inode *inode, struct file *file)
1232 {
1233 fuse_release_common(file, true);
1234
1235 return 0;
1236 }
1237
1238 static int fuse_dir_fsync(struct file *file, loff_t start, loff_t end,
1239 int datasync)
1240 {
1241 struct inode *inode = file->f_mapping->host;
1242 struct fuse_conn *fc = get_fuse_conn(inode);
1243 int err;
1244
1245 if (is_bad_inode(inode))
1246 return -EIO;
1247
1248 if (fc->no_fsyncdir)
1249 return 0;
1250
1251 inode_lock(inode);
1252 err = fuse_fsync_common(file, start, end, datasync, FUSE_FSYNCDIR);
1253 if (err == -ENOSYS) {
1254 fc->no_fsyncdir = 1;
1255 err = 0;
1256 }
1257 inode_unlock(inode);
1258
1259 return err;
1260 }
1261
1262 static long fuse_dir_ioctl(struct file *file, unsigned int cmd,
1263 unsigned long arg)
1264 {
1265 struct fuse_conn *fc = get_fuse_conn(file->f_mapping->host);
1266
1267 /* FUSE_IOCTL_DIR only supported for API version >= 7.18 */
1268 if (fc->minor < 18)
1269 return -ENOTTY;
1270
1271 return fuse_ioctl_common(file, cmd, arg, FUSE_IOCTL_DIR);
1272 }
1273
1274 static long fuse_dir_compat_ioctl(struct file *file, unsigned int cmd,
1275 unsigned long arg)
1276 {
1277 struct fuse_conn *fc = get_fuse_conn(file->f_mapping->host);
1278
1279 if (fc->minor < 18)
1280 return -ENOTTY;
1281
1282 return fuse_ioctl_common(file, cmd, arg,
1283 FUSE_IOCTL_COMPAT | FUSE_IOCTL_DIR);
1284 }
1285
1286 static bool update_mtime(unsigned ivalid, bool trust_local_mtime)
1287 {
1288 /* Always update if mtime is explicitly set */
1289 if (ivalid & ATTR_MTIME_SET)
1290 return true;
1291
1292 /* Or if kernel i_mtime is the official one */
1293 if (trust_local_mtime)
1294 return true;
1295
1296 /* If it's an open(O_TRUNC) or an ftruncate(), don't update */
1297 if ((ivalid & ATTR_SIZE) && (ivalid & (ATTR_OPEN | ATTR_FILE)))
1298 return false;
1299
1300 /* In all other cases update */
1301 return true;
1302 }
1303
1304 static void iattr_to_fattr(struct fuse_conn *fc, struct iattr *iattr,
1305 struct fuse_setattr_in *arg, bool trust_local_cmtime)
1306 {
1307 unsigned ivalid = iattr->ia_valid;
1308
1309 if (ivalid & ATTR_MODE)
1310 arg->valid |= FATTR_MODE, arg->mode = iattr->ia_mode;
1311 if (ivalid & ATTR_UID)
1312 arg->valid |= FATTR_UID, arg->uid = from_kuid(fc->user_ns, iattr->ia_uid);
1313 if (ivalid & ATTR_GID)
1314 arg->valid |= FATTR_GID, arg->gid = from_kgid(fc->user_ns, iattr->ia_gid);
1315 if (ivalid & ATTR_SIZE)
1316 arg->valid |= FATTR_SIZE, arg->size = iattr->ia_size;
1317 if (ivalid & ATTR_ATIME) {
1318 arg->valid |= FATTR_ATIME;
1319 arg->atime = iattr->ia_atime.tv_sec;
1320 arg->atimensec = iattr->ia_atime.tv_nsec;
1321 if (!(ivalid & ATTR_ATIME_SET))
1322 arg->valid |= FATTR_ATIME_NOW;
1323 }
1324 if ((ivalid & ATTR_MTIME) && update_mtime(ivalid, trust_local_cmtime)) {
1325 arg->valid |= FATTR_MTIME;
1326 arg->mtime = iattr->ia_mtime.tv_sec;
1327 arg->mtimensec = iattr->ia_mtime.tv_nsec;
1328 if (!(ivalid & ATTR_MTIME_SET) && !trust_local_cmtime)
1329 arg->valid |= FATTR_MTIME_NOW;
1330 }
1331 if ((ivalid & ATTR_CTIME) && trust_local_cmtime) {
1332 arg->valid |= FATTR_CTIME;
1333 arg->ctime = iattr->ia_ctime.tv_sec;
1334 arg->ctimensec = iattr->ia_ctime.tv_nsec;
1335 }
1336 }
1337
1338 /*
1339 * Prevent concurrent writepages on inode
1340 *
1341 * This is done by adding a negative bias to the inode write counter
1342 * and waiting for all pending writes to finish.
1343 */
1344 void fuse_set_nowrite(struct inode *inode)
1345 {
1346 struct fuse_inode *fi = get_fuse_inode(inode);
1347
1348 BUG_ON(!inode_is_locked(inode));
1349
1350 spin_lock(&fi->lock);
1351 BUG_ON(fi->writectr < 0);
1352 fi->writectr += FUSE_NOWRITE;
1353 spin_unlock(&fi->lock);
1354 wait_event(fi->page_waitq, fi->writectr == FUSE_NOWRITE);
1355 }
1356
1357 /*
1358 * Allow writepages on inode
1359 *
1360 * Remove the bias from the writecounter and send any queued
1361 * writepages.
1362 */
1363 static void __fuse_release_nowrite(struct inode *inode)
1364 {
1365 struct fuse_inode *fi = get_fuse_inode(inode);
1366
1367 BUG_ON(fi->writectr != FUSE_NOWRITE);
1368 fi->writectr = 0;
1369 fuse_flush_writepages(inode);
1370 }
1371
1372 void fuse_release_nowrite(struct inode *inode)
1373 {
1374 struct fuse_inode *fi = get_fuse_inode(inode);
1375
1376 spin_lock(&fi->lock);
1377 __fuse_release_nowrite(inode);
1378 spin_unlock(&fi->lock);
1379 }
1380
1381 static void fuse_setattr_fill(struct fuse_conn *fc, struct fuse_args *args,
1382 struct inode *inode,
1383 struct fuse_setattr_in *inarg_p,
1384 struct fuse_attr_out *outarg_p)
1385 {
1386 args->in.h.opcode = FUSE_SETATTR;
1387 args->in.h.nodeid = get_node_id(inode);
1388 args->in.numargs = 1;
1389 args->in.args[0].size = sizeof(*inarg_p);
1390 args->in.args[0].value = inarg_p;
1391 args->out.numargs = 1;
1392 args->out.args[0].size = sizeof(*outarg_p);
1393 args->out.args[0].value = outarg_p;
1394 }
1395
1396 /*
1397 * Flush inode->i_mtime to the server
1398 */
1399 int fuse_flush_times(struct inode *inode, struct fuse_file *ff)
1400 {
1401 struct fuse_conn *fc = get_fuse_conn(inode);
1402 FUSE_ARGS(args);
1403 struct fuse_setattr_in inarg;
1404 struct fuse_attr_out outarg;
1405
1406 memset(&inarg, 0, sizeof(inarg));
1407 memset(&outarg, 0, sizeof(outarg));
1408
1409 inarg.valid = FATTR_MTIME;
1410 inarg.mtime = inode->i_mtime.tv_sec;
1411 inarg.mtimensec = inode->i_mtime.tv_nsec;
1412 if (fc->minor >= 23) {
1413 inarg.valid |= FATTR_CTIME;
1414 inarg.ctime = inode->i_ctime.tv_sec;
1415 inarg.ctimensec = inode->i_ctime.tv_nsec;
1416 }
1417 if (ff) {
1418 inarg.valid |= FATTR_FH;
1419 inarg.fh = ff->fh;
1420 }
1421 fuse_setattr_fill(fc, &args, inode, &inarg, &outarg);
1422
1423 return fuse_simple_request(fc, &args);
1424 }
1425
1426 /*
1427 * Set attributes, and at the same time refresh them.
1428 *
1429 * Truncation is slightly complicated, because the 'truncate' request
1430 * may fail, in which case we don't want to touch the mapping.
1431 * vmtruncate() doesn't allow for this case, so do the rlimit checking
1432 * and the actual truncation by hand.
1433 */
1434 int fuse_do_setattr(struct dentry *dentry, struct iattr *attr,
1435 struct file *file)
1436 {
1437 struct inode *inode = d_inode(dentry);
1438 struct fuse_conn *fc = get_fuse_conn(inode);
1439 struct fuse_inode *fi = get_fuse_inode(inode);
1440 FUSE_ARGS(args);
1441 struct fuse_setattr_in inarg;
1442 struct fuse_attr_out outarg;
1443 bool is_truncate = false;
1444 bool is_wb = fc->writeback_cache;
1445 loff_t oldsize;
1446 int err;
1447 bool trust_local_cmtime = is_wb && S_ISREG(inode->i_mode);
1448
1449 if (!fc->default_permissions)
1450 attr->ia_valid |= ATTR_FORCE;
1451
1452 err = setattr_prepare(dentry, attr);
1453 if (err)
1454 return err;
1455
1456 if (attr->ia_valid & ATTR_OPEN) {
1457 /* This is coming from open(..., ... | O_TRUNC); */
1458 WARN_ON(!(attr->ia_valid & ATTR_SIZE));
1459 WARN_ON(attr->ia_size != 0);
1460 if (fc->atomic_o_trunc) {
1461 /*
1462 * No need to send request to userspace, since actual
1463 * truncation has already been done by OPEN. But still
1464 * need to truncate page cache.
1465 */
1466 i_size_write(inode, 0);
1467 truncate_pagecache(inode, 0);
1468 return 0;
1469 }
1470 file = NULL;
1471 }
1472
1473 if (attr->ia_valid & ATTR_SIZE) {
1474 if (WARN_ON(!S_ISREG(inode->i_mode)))
1475 return -EIO;
1476 is_truncate = true;
1477 }
1478
1479 if (is_truncate) {
1480 fuse_set_nowrite(inode);
1481 set_bit(FUSE_I_SIZE_UNSTABLE, &fi->state);
1482 if (trust_local_cmtime && attr->ia_size != inode->i_size)
1483 attr->ia_valid |= ATTR_MTIME | ATTR_CTIME;
1484 }
1485
1486 memset(&inarg, 0, sizeof(inarg));
1487 memset(&outarg, 0, sizeof(outarg));
1488 iattr_to_fattr(fc, attr, &inarg, trust_local_cmtime);
1489 if (file) {
1490 struct fuse_file *ff = file->private_data;
1491 inarg.valid |= FATTR_FH;
1492 inarg.fh = ff->fh;
1493 }
1494 if (attr->ia_valid & ATTR_SIZE) {
1495 /* For mandatory locking in truncate */
1496 inarg.valid |= FATTR_LOCKOWNER;
1497 inarg.lock_owner = fuse_lock_owner_id(fc, current->files);
1498 }
1499 fuse_setattr_fill(fc, &args, inode, &inarg, &outarg);
1500 err = fuse_simple_request(fc, &args);
1501 if (err) {
1502 if (err == -EINTR)
1503 fuse_invalidate_attr(inode);
1504 goto error;
1505 }
1506
1507 if ((inode->i_mode ^ outarg.attr.mode) & S_IFMT) {
1508 make_bad_inode(inode);
1509 err = -EIO;
1510 goto error;
1511 }
1512
1513 spin_lock(&fi->lock);
1514 /* the kernel maintains i_mtime locally */
1515 if (trust_local_cmtime) {
1516 if (attr->ia_valid & ATTR_MTIME)
1517 inode->i_mtime = attr->ia_mtime;
1518 if (attr->ia_valid & ATTR_CTIME)
1519 inode->i_ctime = attr->ia_ctime;
1520 /* FIXME: clear I_DIRTY_SYNC? */
1521 }
1522
1523 fuse_change_attributes_common(inode, &outarg.attr,
1524 attr_timeout(&outarg));
1525 oldsize = inode->i_size;
1526 /* see the comment in fuse_change_attributes() */
1527 if (!is_wb || is_truncate || !S_ISREG(inode->i_mode))
1528 i_size_write(inode, outarg.attr.size);
1529
1530 if (is_truncate) {
1531 /* NOTE: this may release/reacquire fi->lock */
1532 __fuse_release_nowrite(inode);
1533 }
1534 spin_unlock(&fi->lock);
1535
1536 /*
1537 * Only call invalidate_inode_pages2() after removing
1538 * FUSE_NOWRITE, otherwise fuse_launder_page() would deadlock.
1539 */
1540 if ((is_truncate || !is_wb) &&
1541 S_ISREG(inode->i_mode) && oldsize != outarg.attr.size) {
1542 truncate_pagecache(inode, outarg.attr.size);
1543 invalidate_inode_pages2(inode->i_mapping);
1544 }
1545
1546 clear_bit(FUSE_I_SIZE_UNSTABLE, &fi->state);
1547 return 0;
1548
1549 error:
1550 if (is_truncate)
1551 fuse_release_nowrite(inode);
1552
1553 clear_bit(FUSE_I_SIZE_UNSTABLE, &fi->state);
1554 return err;
1555 }
1556
1557 static int fuse_setattr(struct dentry *entry, struct iattr *attr)
1558 {
1559 struct inode *inode = d_inode(entry);
1560 struct fuse_conn *fc = get_fuse_conn(inode);
1561 struct file *file = (attr->ia_valid & ATTR_FILE) ? attr->ia_file : NULL;
1562 int ret;
1563
1564 if (!fuse_allow_current_process(get_fuse_conn(inode)))
1565 return -EACCES;
1566
1567 if (attr->ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID)) {
1568 attr->ia_valid &= ~(ATTR_KILL_SUID | ATTR_KILL_SGID |
1569 ATTR_MODE);
1570
1571 /*
1572 * The only sane way to reliably kill suid/sgid is to do it in
1573 * the userspace filesystem
1574 *
1575 * This should be done on write(), truncate() and chown().
1576 */
1577 if (!fc->handle_killpriv) {
1578 /*
1579 * ia_mode calculation may have used stale i_mode.
1580 * Refresh and recalculate.
1581 */
1582 ret = fuse_do_getattr(inode, NULL, file);
1583 if (ret)
1584 return ret;
1585
1586 attr->ia_mode = inode->i_mode;
1587 if (inode->i_mode & S_ISUID) {
1588 attr->ia_valid |= ATTR_MODE;
1589 attr->ia_mode &= ~S_ISUID;
1590 }
1591 if ((inode->i_mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP)) {
1592 attr->ia_valid |= ATTR_MODE;
1593 attr->ia_mode &= ~S_ISGID;
1594 }
1595 }
1596 }
1597 if (!attr->ia_valid)
1598 return 0;
1599
1600 ret = fuse_do_setattr(entry, attr, file);
1601 if (!ret) {
1602 /*
1603 * If filesystem supports acls it may have updated acl xattrs in
1604 * the filesystem, so forget cached acls for the inode.
1605 */
1606 if (fc->posix_acl)
1607 forget_all_cached_acls(inode);
1608
1609 /* Directory mode changed, may need to revalidate access */
1610 if (d_is_dir(entry) && (attr->ia_valid & ATTR_MODE))
1611 fuse_invalidate_entry_cache(entry);
1612 }
1613 return ret;
1614 }
1615
1616 static int fuse_getattr(const struct path *path, struct kstat *stat,
1617 u32 request_mask, unsigned int flags)
1618 {
1619 struct inode *inode = d_inode(path->dentry);
1620 struct fuse_conn *fc = get_fuse_conn(inode);
1621
1622 if (!fuse_allow_current_process(fc))
1623 return -EACCES;
1624
1625 return fuse_update_get_attr(inode, NULL, stat, request_mask, flags);
1626 }
1627
1628 static const struct inode_operations fuse_dir_inode_operations = {
1629 .lookup = fuse_lookup,
1630 .mkdir = fuse_mkdir,
1631 .symlink = fuse_symlink,
1632 .unlink = fuse_unlink,
1633 .rmdir = fuse_rmdir,
1634 .rename = fuse_rename2,
1635 .link = fuse_link,
1636 .setattr = fuse_setattr,
1637 .create = fuse_create,
1638 .atomic_open = fuse_atomic_open,
1639 .mknod = fuse_mknod,
1640 .permission = fuse_permission,
1641 .getattr = fuse_getattr,
1642 .listxattr = fuse_listxattr,
1643 .get_acl = fuse_get_acl,
1644 .set_acl = fuse_set_acl,
1645 };
1646
1647 static const struct file_operations fuse_dir_operations = {
1648 .llseek = generic_file_llseek,
1649 .read = generic_read_dir,
1650 .iterate_shared = fuse_readdir,
1651 .open = fuse_dir_open,
1652 .release = fuse_dir_release,
1653 .fsync = fuse_dir_fsync,
1654 .unlocked_ioctl = fuse_dir_ioctl,
1655 .compat_ioctl = fuse_dir_compat_ioctl,
1656 };
1657
1658 static const struct inode_operations fuse_common_inode_operations = {
1659 .setattr = fuse_setattr,
1660 .permission = fuse_permission,
1661 .getattr = fuse_getattr,
1662 .listxattr = fuse_listxattr,
1663 .get_acl = fuse_get_acl,
1664 .set_acl = fuse_set_acl,
1665 };
1666
1667 static const struct inode_operations fuse_symlink_inode_operations = {
1668 .setattr = fuse_setattr,
1669 .get_link = fuse_get_link,
1670 .getattr = fuse_getattr,
1671 .listxattr = fuse_listxattr,
1672 };
1673
1674 void fuse_init_common(struct inode *inode)
1675 {
1676 inode->i_op = &fuse_common_inode_operations;
1677 }
1678
1679 void fuse_init_dir(struct inode *inode)
1680 {
1681 struct fuse_inode *fi = get_fuse_inode(inode);
1682
1683 inode->i_op = &fuse_dir_inode_operations;
1684 inode->i_fop = &fuse_dir_operations;
1685
1686 spin_lock_init(&fi->rdc.lock);
1687 fi->rdc.cached = false;
1688 fi->rdc.size = 0;
1689 fi->rdc.pos = 0;
1690 fi->rdc.version = 0;
1691 }
1692
1693 static int fuse_symlink_readpage(struct file *null, struct page *page)
1694 {
1695 int err = fuse_readlink_page(page->mapping->host, page);
1696
1697 if (!err)
1698 SetPageUptodate(page);
1699
1700 unlock_page(page);
1701
1702 return err;
1703 }
1704
1705 static const struct address_space_operations fuse_symlink_aops = {
1706 .readpage = fuse_symlink_readpage,
1707 };
1708
1709 void fuse_init_symlink(struct inode *inode)
1710 {
1711 inode->i_op = &fuse_symlink_inode_operations;
1712 inode->i_data.a_ops = &fuse_symlink_aops;
1713 inode_nohighmem(inode);
1714 }
Ubuntu combined Linux kernel mirror