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
fuse_dentry_settime(struct dentry * entry,u64 time)18 static inline void fuse_dentry_settime(struct dentry *entry, u64 time)
19 {
20 entry->d_time = time;
21 }
22
fuse_dentry_time(struct dentry * entry)23 static inline u64 fuse_dentry_time(struct dentry *entry)
24 {
25 return entry->d_time;
26 }
27 #else
28 /*
29 * On 32 bit archs store the high 32 bits of time in d_fsdata
30 */
fuse_dentry_settime(struct dentry * entry,u64 time)31 static void fuse_dentry_settime(struct dentry *entry, u64 time)
32 {
33 entry->d_time = time;
34 entry->d_fsdata = (void *) (unsigned long) (time >> 32);
35 }
36
fuse_dentry_time(struct dentry * entry)37 static u64 fuse_dentry_time(struct dentry *entry)
38 {
39 return (u64) entry->d_time +
40 ((u64) (unsigned long) entry->d_fsdata << 32);
41 }
42 #endif
43
44 /*
45 * FUSE caches dentries and attributes with separate timeout. The
46 * time in jiffies until the dentry/attributes are valid is stored in
47 * dentry->d_time and fuse_inode->i_time respectively.
48 */
49
50 /*
51 * Calculate the time in jiffies until a dentry/attributes are valid
52 */
time_to_jiffies(unsigned long sec,unsigned long nsec)53 static u64 time_to_jiffies(unsigned long sec, unsigned long nsec)
54 {
55 if (sec || nsec) {
56 struct timespec ts = {sec, nsec};
57 return get_jiffies_64() + timespec_to_jiffies(&ts);
58 } else
59 return 0;
60 }
61
62 /*
63 * Set dentry and possibly attribute timeouts from the lookup/mk*
64 * replies
65 */
fuse_change_entry_timeout(struct dentry * entry,struct fuse_entry_out * o)66 static void fuse_change_entry_timeout(struct dentry *entry,
67 struct fuse_entry_out *o)
68 {
69 fuse_dentry_settime(entry,
70 time_to_jiffies(o->entry_valid, o->entry_valid_nsec));
71 }
72
attr_timeout(struct fuse_attr_out * o)73 static u64 attr_timeout(struct fuse_attr_out *o)
74 {
75 return time_to_jiffies(o->attr_valid, o->attr_valid_nsec);
76 }
77
entry_attr_timeout(struct fuse_entry_out * o)78 static u64 entry_attr_timeout(struct fuse_entry_out *o)
79 {
80 return time_to_jiffies(o->attr_valid, o->attr_valid_nsec);
81 }
82
83 /*
84 * Mark the attributes as stale, so that at the next call to
85 * ->getattr() they will be fetched from userspace
86 */
fuse_invalidate_attr(struct inode * inode)87 void fuse_invalidate_attr(struct inode *inode)
88 {
89 get_fuse_inode(inode)->i_time = 0;
90 }
91
92 /*
93 * Just mark the entry as stale, so that a next attempt to look it up
94 * will result in a new lookup call to userspace
95 *
96 * This is called when a dentry is about to become negative and the
97 * timeout is unknown (unlink, rmdir, rename and in some cases
98 * lookup)
99 */
fuse_invalidate_entry_cache(struct dentry * entry)100 void fuse_invalidate_entry_cache(struct dentry *entry)
101 {
102 fuse_dentry_settime(entry, 0);
103 }
104
105 /*
106 * Same as fuse_invalidate_entry_cache(), but also try to remove the
107 * dentry from the hash
108 */
fuse_invalidate_entry(struct dentry * entry)109 static void fuse_invalidate_entry(struct dentry *entry)
110 {
111 d_invalidate(entry);
112 fuse_invalidate_entry_cache(entry);
113 }
114
fuse_lookup_init(struct fuse_conn * fc,struct fuse_req * req,u64 nodeid,struct qstr * name,struct fuse_entry_out * outarg)115 static void fuse_lookup_init(struct fuse_conn *fc, struct fuse_req *req,
116 u64 nodeid, struct qstr *name,
117 struct fuse_entry_out *outarg)
118 {
119 memset(outarg, 0, sizeof(struct fuse_entry_out));
120 req->in.h.opcode = FUSE_LOOKUP;
121 req->in.h.nodeid = nodeid;
122 req->in.numargs = 1;
123 req->in.args[0].size = name->len + 1;
124 req->in.args[0].value = name->name;
125 req->out.numargs = 1;
126 if (fc->minor < 9)
127 req->out.args[0].size = FUSE_COMPAT_ENTRY_OUT_SIZE;
128 else
129 req->out.args[0].size = sizeof(struct fuse_entry_out);
130 req->out.args[0].value = outarg;
131 }
132
fuse_get_attr_version(struct fuse_conn * fc)133 u64 fuse_get_attr_version(struct fuse_conn *fc)
134 {
135 u64 curr_version;
136
137 /*
138 * The spin lock isn't actually needed on 64bit archs, but we
139 * don't yet care too much about such optimizations.
140 */
141 spin_lock(&fc->lock);
142 curr_version = fc->attr_version;
143 spin_unlock(&fc->lock);
144
145 return curr_version;
146 }
147
148 /*
149 * Check whether the dentry is still valid
150 *
151 * If the entry validity timeout has expired and the dentry is
152 * positive, try to redo the lookup. If the lookup results in a
153 * different inode, then let the VFS invalidate the dentry and redo
154 * the lookup once more. If the lookup results in the same inode,
155 * then refresh the attributes, timeouts and mark the dentry valid.
156 */
fuse_dentry_revalidate(struct dentry * entry,struct nameidata * nd)157 static int fuse_dentry_revalidate(struct dentry *entry, struct nameidata *nd)
158 {
159 struct inode *inode;
160
161 inode = ACCESS_ONCE(entry->d_inode);
162 if (inode && is_bad_inode(inode))
163 return 0;
164 else if (fuse_dentry_time(entry) < get_jiffies_64()) {
165 int err;
166 struct fuse_entry_out outarg;
167 struct fuse_conn *fc;
168 struct fuse_req *req;
169 struct fuse_forget_link *forget;
170 struct dentry *parent;
171 u64 attr_version;
172
173 /* For negative dentries, always do a fresh lookup */
174 if (!inode)
175 return 0;
176
177 if (nd && (nd->flags & LOOKUP_RCU))
178 return -ECHILD;
179
180 fc = get_fuse_conn(inode);
181 req = fuse_get_req(fc);
182 if (IS_ERR(req))
183 return 0;
184
185 forget = fuse_alloc_forget();
186 if (!forget) {
187 fuse_put_request(fc, req);
188 return 0;
189 }
190
191 attr_version = fuse_get_attr_version(fc);
192
193 parent = dget_parent(entry);
194 fuse_lookup_init(fc, req, get_node_id(parent->d_inode),
195 &entry->d_name, &outarg);
196 fuse_request_send(fc, req);
197 dput(parent);
198 err = req->out.h.error;
199 fuse_put_request(fc, req);
200 /* Zero nodeid is same as -ENOENT */
201 if (!err && !outarg.nodeid)
202 err = -ENOENT;
203 if (!err) {
204 struct fuse_inode *fi = get_fuse_inode(inode);
205 if (outarg.nodeid != get_node_id(inode)) {
206 fuse_queue_forget(fc, forget, outarg.nodeid, 1);
207 return 0;
208 }
209 spin_lock(&fc->lock);
210 fi->nlookup++;
211 spin_unlock(&fc->lock);
212 }
213 kfree(forget);
214 if (err || (outarg.attr.mode ^ inode->i_mode) & S_IFMT)
215 return 0;
216
217 fuse_change_attributes(inode, &outarg.attr,
218 entry_attr_timeout(&outarg),
219 attr_version);
220 fuse_change_entry_timeout(entry, &outarg);
221 }
222 return 1;
223 }
224
invalid_nodeid(u64 nodeid)225 static int invalid_nodeid(u64 nodeid)
226 {
227 return !nodeid || nodeid == FUSE_ROOT_ID;
228 }
229
230 const struct dentry_operations fuse_dentry_operations = {
231 .d_revalidate = fuse_dentry_revalidate,
232 };
233
fuse_valid_type(int m)234 int fuse_valid_type(int m)
235 {
236 return S_ISREG(m) || S_ISDIR(m) || S_ISLNK(m) || S_ISCHR(m) ||
237 S_ISBLK(m) || S_ISFIFO(m) || S_ISSOCK(m);
238 }
239
240 /*
241 * Add a directory inode to a dentry, ensuring that no other dentry
242 * refers to this inode. Called with fc->inst_mutex.
243 */
fuse_d_add_directory(struct dentry * entry,struct inode * inode)244 static struct dentry *fuse_d_add_directory(struct dentry *entry,
245 struct inode *inode)
246 {
247 struct dentry *alias = d_find_alias(inode);
248 if (alias && !(alias->d_flags & DCACHE_DISCONNECTED)) {
249 /* This tries to shrink the subtree below alias */
250 fuse_invalidate_entry(alias);
251 dput(alias);
252 if (!list_empty(&inode->i_dentry))
253 return ERR_PTR(-EBUSY);
254 } else {
255 dput(alias);
256 }
257 return d_splice_alias(inode, entry);
258 }
259
fuse_lookup_name(struct super_block * sb,u64 nodeid,struct qstr * name,struct fuse_entry_out * outarg,struct inode ** inode)260 int fuse_lookup_name(struct super_block *sb, u64 nodeid, struct qstr *name,
261 struct fuse_entry_out *outarg, struct inode **inode)
262 {
263 struct fuse_conn *fc = get_fuse_conn_super(sb);
264 struct fuse_req *req;
265 struct fuse_forget_link *forget;
266 u64 attr_version;
267 int err;
268
269 *inode = NULL;
270 err = -ENAMETOOLONG;
271 if (name->len > FUSE_NAME_MAX)
272 goto out;
273
274 req = fuse_get_req(fc);
275 err = PTR_ERR(req);
276 if (IS_ERR(req))
277 goto out;
278
279 forget = fuse_alloc_forget();
280 err = -ENOMEM;
281 if (!forget) {
282 fuse_put_request(fc, req);
283 goto out;
284 }
285
286 attr_version = fuse_get_attr_version(fc);
287
288 fuse_lookup_init(fc, req, nodeid, name, outarg);
289 fuse_request_send(fc, req);
290 err = req->out.h.error;
291 fuse_put_request(fc, req);
292 /* Zero nodeid is same as -ENOENT, but with valid timeout */
293 if (err || !outarg->nodeid)
294 goto out_put_forget;
295
296 err = -EIO;
297 if (!outarg->nodeid)
298 goto out_put_forget;
299 if (!fuse_valid_type(outarg->attr.mode))
300 goto out_put_forget;
301
302 *inode = fuse_iget(sb, outarg->nodeid, outarg->generation,
303 &outarg->attr, entry_attr_timeout(outarg),
304 attr_version);
305 err = -ENOMEM;
306 if (!*inode) {
307 fuse_queue_forget(fc, forget, outarg->nodeid, 1);
308 goto out;
309 }
310 err = 0;
311
312 out_put_forget:
313 kfree(forget);
314 out:
315 return err;
316 }
317
fuse_lookup(struct inode * dir,struct dentry * entry,struct nameidata * nd)318 static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry,
319 struct nameidata *nd)
320 {
321 int err;
322 struct fuse_entry_out outarg;
323 struct inode *inode;
324 struct dentry *newent;
325 struct fuse_conn *fc = get_fuse_conn(dir);
326 bool outarg_valid = true;
327
328 err = fuse_lookup_name(dir->i_sb, get_node_id(dir), &entry->d_name,
329 &outarg, &inode);
330 if (err == -ENOENT) {
331 outarg_valid = false;
332 err = 0;
333 }
334 if (err)
335 goto out_err;
336
337 err = -EIO;
338 if (inode && get_node_id(inode) == FUSE_ROOT_ID)
339 goto out_iput;
340
341 if (inode && S_ISDIR(inode->i_mode)) {
342 mutex_lock(&fc->inst_mutex);
343 newent = fuse_d_add_directory(entry, inode);
344 mutex_unlock(&fc->inst_mutex);
345 err = PTR_ERR(newent);
346 if (IS_ERR(newent))
347 goto out_iput;
348 } else {
349 newent = d_splice_alias(inode, entry);
350 }
351
352 entry = newent ? newent : entry;
353 if (outarg_valid)
354 fuse_change_entry_timeout(entry, &outarg);
355 else
356 fuse_invalidate_entry_cache(entry);
357
358 return newent;
359
360 out_iput:
361 iput(inode);
362 out_err:
363 return ERR_PTR(err);
364 }
365
366 /*
367 * Atomic create+open operation
368 *
369 * If the filesystem doesn't support this, then fall back to separate
370 * 'mknod' + 'open' requests.
371 */
fuse_create_open(struct inode * dir,struct dentry * entry,int mode,struct nameidata * nd)372 static int fuse_create_open(struct inode *dir, struct dentry *entry, int mode,
373 struct nameidata *nd)
374 {
375 int err;
376 struct inode *inode;
377 struct fuse_conn *fc = get_fuse_conn(dir);
378 struct fuse_req *req;
379 struct fuse_forget_link *forget;
380 struct fuse_create_in inarg;
381 struct fuse_open_out outopen;
382 struct fuse_entry_out outentry;
383 struct fuse_file *ff;
384 struct file *file;
385 int flags = nd->intent.open.flags - 1;
386
387 if (fc->no_create)
388 return -ENOSYS;
389
390 if (flags & O_DIRECT)
391 return -EINVAL;
392
393 forget = fuse_alloc_forget();
394 if (!forget)
395 return -ENOMEM;
396
397 req = fuse_get_req(fc);
398 err = PTR_ERR(req);
399 if (IS_ERR(req))
400 goto out_put_forget_req;
401
402 err = -ENOMEM;
403 ff = fuse_file_alloc(fc);
404 if (!ff)
405 goto out_put_request;
406
407 if (!fc->dont_mask)
408 mode &= ~current_umask();
409
410 flags &= ~O_NOCTTY;
411 memset(&inarg, 0, sizeof(inarg));
412 memset(&outentry, 0, sizeof(outentry));
413 inarg.flags = flags;
414 inarg.mode = mode;
415 inarg.umask = current_umask();
416 req->in.h.opcode = FUSE_CREATE;
417 req->in.h.nodeid = get_node_id(dir);
418 req->in.numargs = 2;
419 req->in.args[0].size = fc->minor < 12 ? sizeof(struct fuse_open_in) :
420 sizeof(inarg);
421 req->in.args[0].value = &inarg;
422 req->in.args[1].size = entry->d_name.len + 1;
423 req->in.args[1].value = entry->d_name.name;
424 req->out.numargs = 2;
425 if (fc->minor < 9)
426 req->out.args[0].size = FUSE_COMPAT_ENTRY_OUT_SIZE;
427 else
428 req->out.args[0].size = sizeof(outentry);
429 req->out.args[0].value = &outentry;
430 req->out.args[1].size = sizeof(outopen);
431 req->out.args[1].value = &outopen;
432 fuse_request_send(fc, req);
433 err = req->out.h.error;
434 if (err) {
435 if (err == -ENOSYS)
436 fc->no_create = 1;
437 goto out_free_ff;
438 }
439
440 err = -EIO;
441 if (!S_ISREG(outentry.attr.mode) || invalid_nodeid(outentry.nodeid))
442 goto out_free_ff;
443
444 fuse_put_request(fc, req);
445 ff->fh = outopen.fh;
446 ff->nodeid = outentry.nodeid;
447 ff->open_flags = outopen.open_flags;
448 inode = fuse_iget(dir->i_sb, outentry.nodeid, outentry.generation,
449 &outentry.attr, entry_attr_timeout(&outentry), 0);
450 if (!inode) {
451 flags &= ~(O_CREAT | O_EXCL | O_TRUNC);
452 fuse_sync_release(ff, flags);
453 fuse_queue_forget(fc, forget, outentry.nodeid, 1);
454 return -ENOMEM;
455 }
456 kfree(forget);
457 d_instantiate(entry, inode);
458 fuse_change_entry_timeout(entry, &outentry);
459 fuse_invalidate_attr(dir);
460 file = lookup_instantiate_filp(nd, entry, generic_file_open);
461 if (IS_ERR(file)) {
462 fuse_sync_release(ff, flags);
463 return PTR_ERR(file);
464 }
465 file->private_data = fuse_file_get(ff);
466 fuse_finish_open(inode, file);
467 return 0;
468
469 out_free_ff:
470 fuse_file_free(ff);
471 out_put_request:
472 fuse_put_request(fc, req);
473 out_put_forget_req:
474 kfree(forget);
475 return err;
476 }
477
478 /*
479 * Code shared between mknod, mkdir, symlink and link
480 */
create_new_entry(struct fuse_conn * fc,struct fuse_req * req,struct inode * dir,struct dentry * entry,int mode)481 static int create_new_entry(struct fuse_conn *fc, struct fuse_req *req,
482 struct inode *dir, struct dentry *entry,
483 int mode)
484 {
485 struct fuse_entry_out outarg;
486 struct inode *inode;
487 int err;
488 struct fuse_forget_link *forget;
489
490 forget = fuse_alloc_forget();
491 if (!forget) {
492 fuse_put_request(fc, req);
493 return -ENOMEM;
494 }
495
496 memset(&outarg, 0, sizeof(outarg));
497 req->in.h.nodeid = get_node_id(dir);
498 req->out.numargs = 1;
499 if (fc->minor < 9)
500 req->out.args[0].size = FUSE_COMPAT_ENTRY_OUT_SIZE;
501 else
502 req->out.args[0].size = sizeof(outarg);
503 req->out.args[0].value = &outarg;
504 fuse_request_send(fc, req);
505 err = req->out.h.error;
506 fuse_put_request(fc, req);
507 if (err)
508 goto out_put_forget_req;
509
510 err = -EIO;
511 if (invalid_nodeid(outarg.nodeid))
512 goto out_put_forget_req;
513
514 if ((outarg.attr.mode ^ mode) & S_IFMT)
515 goto out_put_forget_req;
516
517 inode = fuse_iget(dir->i_sb, outarg.nodeid, outarg.generation,
518 &outarg.attr, entry_attr_timeout(&outarg), 0);
519 if (!inode) {
520 fuse_queue_forget(fc, forget, outarg.nodeid, 1);
521 return -ENOMEM;
522 }
523 kfree(forget);
524
525 if (S_ISDIR(inode->i_mode)) {
526 struct dentry *alias;
527 mutex_lock(&fc->inst_mutex);
528 alias = d_find_alias(inode);
529 if (alias) {
530 /* New directory must have moved since mkdir */
531 mutex_unlock(&fc->inst_mutex);
532 dput(alias);
533 iput(inode);
534 return -EBUSY;
535 }
536 d_instantiate(entry, inode);
537 mutex_unlock(&fc->inst_mutex);
538 } else
539 d_instantiate(entry, inode);
540
541 fuse_change_entry_timeout(entry, &outarg);
542 fuse_invalidate_attr(dir);
543 return 0;
544
545 out_put_forget_req:
546 kfree(forget);
547 return err;
548 }
549
fuse_mknod(struct inode * dir,struct dentry * entry,int mode,dev_t rdev)550 static int fuse_mknod(struct inode *dir, struct dentry *entry, int mode,
551 dev_t rdev)
552 {
553 struct fuse_mknod_in inarg;
554 struct fuse_conn *fc = get_fuse_conn(dir);
555 struct fuse_req *req = fuse_get_req(fc);
556 if (IS_ERR(req))
557 return PTR_ERR(req);
558
559 if (!fc->dont_mask)
560 mode &= ~current_umask();
561
562 memset(&inarg, 0, sizeof(inarg));
563 inarg.mode = mode;
564 inarg.rdev = new_encode_dev(rdev);
565 inarg.umask = current_umask();
566 req->in.h.opcode = FUSE_MKNOD;
567 req->in.numargs = 2;
568 req->in.args[0].size = fc->minor < 12 ? FUSE_COMPAT_MKNOD_IN_SIZE :
569 sizeof(inarg);
570 req->in.args[0].value = &inarg;
571 req->in.args[1].size = entry->d_name.len + 1;
572 req->in.args[1].value = entry->d_name.name;
573 return create_new_entry(fc, req, dir, entry, mode);
574 }
575
fuse_create(struct inode * dir,struct dentry * entry,int mode,struct nameidata * nd)576 static int fuse_create(struct inode *dir, struct dentry *entry, int mode,
577 struct nameidata *nd)
578 {
579 if (nd && (nd->flags & LOOKUP_OPEN)) {
580 int err = fuse_create_open(dir, entry, mode, nd);
581 if (err != -ENOSYS)
582 return err;
583 /* Fall back on mknod */
584 }
585 return fuse_mknod(dir, entry, mode, 0);
586 }
587
fuse_mkdir(struct inode * dir,struct dentry * entry,int mode)588 static int fuse_mkdir(struct inode *dir, struct dentry *entry, int mode)
589 {
590 struct fuse_mkdir_in inarg;
591 struct fuse_conn *fc = get_fuse_conn(dir);
592 struct fuse_req *req = fuse_get_req(fc);
593 if (IS_ERR(req))
594 return PTR_ERR(req);
595
596 if (!fc->dont_mask)
597 mode &= ~current_umask();
598
599 memset(&inarg, 0, sizeof(inarg));
600 inarg.mode = mode;
601 inarg.umask = current_umask();
602 req->in.h.opcode = FUSE_MKDIR;
603 req->in.numargs = 2;
604 req->in.args[0].size = sizeof(inarg);
605 req->in.args[0].value = &inarg;
606 req->in.args[1].size = entry->d_name.len + 1;
607 req->in.args[1].value = entry->d_name.name;
608 return create_new_entry(fc, req, dir, entry, S_IFDIR);
609 }
610
fuse_symlink(struct inode * dir,struct dentry * entry,const char * link)611 static int fuse_symlink(struct inode *dir, struct dentry *entry,
612 const char *link)
613 {
614 struct fuse_conn *fc = get_fuse_conn(dir);
615 unsigned len = strlen(link) + 1;
616 struct fuse_req *req = fuse_get_req(fc);
617 if (IS_ERR(req))
618 return PTR_ERR(req);
619
620 req->in.h.opcode = FUSE_SYMLINK;
621 req->in.numargs = 2;
622 req->in.args[0].size = entry->d_name.len + 1;
623 req->in.args[0].value = entry->d_name.name;
624 req->in.args[1].size = len;
625 req->in.args[1].value = link;
626 return create_new_entry(fc, req, dir, entry, S_IFLNK);
627 }
628
fuse_unlink(struct inode * dir,struct dentry * entry)629 static int fuse_unlink(struct inode *dir, struct dentry *entry)
630 {
631 int err;
632 struct fuse_conn *fc = get_fuse_conn(dir);
633 struct fuse_req *req = fuse_get_req(fc);
634 if (IS_ERR(req))
635 return PTR_ERR(req);
636
637 req->in.h.opcode = FUSE_UNLINK;
638 req->in.h.nodeid = get_node_id(dir);
639 req->in.numargs = 1;
640 req->in.args[0].size = entry->d_name.len + 1;
641 req->in.args[0].value = entry->d_name.name;
642 fuse_request_send(fc, req);
643 err = req->out.h.error;
644 fuse_put_request(fc, req);
645 if (!err) {
646 struct inode *inode = entry->d_inode;
647
648 /*
649 * Set nlink to zero so the inode can be cleared, if the inode
650 * does have more links this will be discovered at the next
651 * lookup/getattr.
652 */
653 clear_nlink(inode);
654 fuse_invalidate_attr(inode);
655 fuse_invalidate_attr(dir);
656 fuse_invalidate_entry_cache(entry);
657 } else if (err == -EINTR)
658 fuse_invalidate_entry(entry);
659 return err;
660 }
661
fuse_rmdir(struct inode * dir,struct dentry * entry)662 static int fuse_rmdir(struct inode *dir, struct dentry *entry)
663 {
664 int err;
665 struct fuse_conn *fc = get_fuse_conn(dir);
666 struct fuse_req *req = fuse_get_req(fc);
667 if (IS_ERR(req))
668 return PTR_ERR(req);
669
670 req->in.h.opcode = FUSE_RMDIR;
671 req->in.h.nodeid = get_node_id(dir);
672 req->in.numargs = 1;
673 req->in.args[0].size = entry->d_name.len + 1;
674 req->in.args[0].value = entry->d_name.name;
675 fuse_request_send(fc, req);
676 err = req->out.h.error;
677 fuse_put_request(fc, req);
678 if (!err) {
679 clear_nlink(entry->d_inode);
680 fuse_invalidate_attr(dir);
681 fuse_invalidate_entry_cache(entry);
682 } else if (err == -EINTR)
683 fuse_invalidate_entry(entry);
684 return err;
685 }
686
fuse_rename(struct inode * olddir,struct dentry * oldent,struct inode * newdir,struct dentry * newent)687 static int fuse_rename(struct inode *olddir, struct dentry *oldent,
688 struct inode *newdir, struct dentry *newent)
689 {
690 int err;
691 struct fuse_rename_in inarg;
692 struct fuse_conn *fc = get_fuse_conn(olddir);
693 struct fuse_req *req = fuse_get_req(fc);
694 if (IS_ERR(req))
695 return PTR_ERR(req);
696
697 memset(&inarg, 0, sizeof(inarg));
698 inarg.newdir = get_node_id(newdir);
699 req->in.h.opcode = FUSE_RENAME;
700 req->in.h.nodeid = get_node_id(olddir);
701 req->in.numargs = 3;
702 req->in.args[0].size = sizeof(inarg);
703 req->in.args[0].value = &inarg;
704 req->in.args[1].size = oldent->d_name.len + 1;
705 req->in.args[1].value = oldent->d_name.name;
706 req->in.args[2].size = newent->d_name.len + 1;
707 req->in.args[2].value = newent->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 /* ctime changes */
713 fuse_invalidate_attr(oldent->d_inode);
714
715 fuse_invalidate_attr(olddir);
716 if (olddir != newdir)
717 fuse_invalidate_attr(newdir);
718
719 /* newent will end up negative */
720 if (newent->d_inode) {
721 fuse_invalidate_attr(newent->d_inode);
722 fuse_invalidate_entry_cache(newent);
723 }
724 } else if (err == -EINTR) {
725 /* If request was interrupted, DEITY only knows if the
726 rename actually took place. If the invalidation
727 fails (e.g. some process has CWD under the renamed
728 directory), then there can be inconsistency between
729 the dcache and the real filesystem. Tough luck. */
730 fuse_invalidate_entry(oldent);
731 if (newent->d_inode)
732 fuse_invalidate_entry(newent);
733 }
734
735 return err;
736 }
737
fuse_link(struct dentry * entry,struct inode * newdir,struct dentry * newent)738 static int fuse_link(struct dentry *entry, struct inode *newdir,
739 struct dentry *newent)
740 {
741 int err;
742 struct fuse_link_in inarg;
743 struct inode *inode = entry->d_inode;
744 struct fuse_conn *fc = get_fuse_conn(inode);
745 struct fuse_req *req = fuse_get_req(fc);
746 if (IS_ERR(req))
747 return PTR_ERR(req);
748
749 memset(&inarg, 0, sizeof(inarg));
750 inarg.oldnodeid = get_node_id(inode);
751 req->in.h.opcode = FUSE_LINK;
752 req->in.numargs = 2;
753 req->in.args[0].size = sizeof(inarg);
754 req->in.args[0].value = &inarg;
755 req->in.args[1].size = newent->d_name.len + 1;
756 req->in.args[1].value = newent->d_name.name;
757 err = create_new_entry(fc, req, newdir, newent, inode->i_mode);
758 /* Contrary to "normal" filesystems it can happen that link
759 makes two "logical" inodes point to the same "physical"
760 inode. We invalidate the attributes of the old one, so it
761 will reflect changes in the backing inode (link count,
762 etc.)
763 */
764 if (!err || err == -EINTR)
765 fuse_invalidate_attr(inode);
766 return err;
767 }
768
fuse_fillattr(struct inode * inode,struct fuse_attr * attr,struct kstat * stat)769 static void fuse_fillattr(struct inode *inode, struct fuse_attr *attr,
770 struct kstat *stat)
771 {
772 stat->dev = inode->i_sb->s_dev;
773 stat->ino = attr->ino;
774 stat->mode = (inode->i_mode & S_IFMT) | (attr->mode & 07777);
775 stat->nlink = attr->nlink;
776 stat->uid = attr->uid;
777 stat->gid = attr->gid;
778 stat->rdev = inode->i_rdev;
779 stat->atime.tv_sec = attr->atime;
780 stat->atime.tv_nsec = attr->atimensec;
781 stat->mtime.tv_sec = attr->mtime;
782 stat->mtime.tv_nsec = attr->mtimensec;
783 stat->ctime.tv_sec = attr->ctime;
784 stat->ctime.tv_nsec = attr->ctimensec;
785 stat->size = attr->size;
786 stat->blocks = attr->blocks;
787 stat->blksize = (1 << inode->i_blkbits);
788 }
789
fuse_do_getattr(struct inode * inode,struct kstat * stat,struct file * file)790 static int fuse_do_getattr(struct inode *inode, struct kstat *stat,
791 struct file *file)
792 {
793 int err;
794 struct fuse_getattr_in inarg;
795 struct fuse_attr_out outarg;
796 struct fuse_conn *fc = get_fuse_conn(inode);
797 struct fuse_req *req;
798 u64 attr_version;
799
800 req = fuse_get_req(fc);
801 if (IS_ERR(req))
802 return PTR_ERR(req);
803
804 attr_version = fuse_get_attr_version(fc);
805
806 memset(&inarg, 0, sizeof(inarg));
807 memset(&outarg, 0, sizeof(outarg));
808 /* Directories have separate file-handle space */
809 if (file && S_ISREG(inode->i_mode)) {
810 struct fuse_file *ff = file->private_data;
811
812 inarg.getattr_flags |= FUSE_GETATTR_FH;
813 inarg.fh = ff->fh;
814 }
815 req->in.h.opcode = FUSE_GETATTR;
816 req->in.h.nodeid = get_node_id(inode);
817 req->in.numargs = 1;
818 req->in.args[0].size = sizeof(inarg);
819 req->in.args[0].value = &inarg;
820 req->out.numargs = 1;
821 if (fc->minor < 9)
822 req->out.args[0].size = FUSE_COMPAT_ATTR_OUT_SIZE;
823 else
824 req->out.args[0].size = sizeof(outarg);
825 req->out.args[0].value = &outarg;
826 fuse_request_send(fc, req);
827 err = req->out.h.error;
828 fuse_put_request(fc, req);
829 if (!err) {
830 if ((inode->i_mode ^ outarg.attr.mode) & S_IFMT) {
831 make_bad_inode(inode);
832 err = -EIO;
833 } else {
834 fuse_change_attributes(inode, &outarg.attr,
835 attr_timeout(&outarg),
836 attr_version);
837 if (stat)
838 fuse_fillattr(inode, &outarg.attr, stat);
839 }
840 }
841 return err;
842 }
843
fuse_update_attributes(struct inode * inode,struct kstat * stat,struct file * file,bool * refreshed)844 int fuse_update_attributes(struct inode *inode, struct kstat *stat,
845 struct file *file, bool *refreshed)
846 {
847 struct fuse_inode *fi = get_fuse_inode(inode);
848 int err;
849 bool r;
850
851 if (fi->i_time < get_jiffies_64()) {
852 r = true;
853 err = fuse_do_getattr(inode, stat, file);
854 } else {
855 r = false;
856 err = 0;
857 if (stat) {
858 generic_fillattr(inode, stat);
859 stat->mode = fi->orig_i_mode;
860 }
861 }
862
863 if (refreshed != NULL)
864 *refreshed = r;
865
866 return err;
867 }
868
fuse_reverse_inval_entry(struct super_block * sb,u64 parent_nodeid,struct qstr * name)869 int fuse_reverse_inval_entry(struct super_block *sb, u64 parent_nodeid,
870 struct qstr *name)
871 {
872 int err = -ENOTDIR;
873 struct inode *parent;
874 struct dentry *dir;
875 struct dentry *entry;
876
877 parent = ilookup5(sb, parent_nodeid, fuse_inode_eq, &parent_nodeid);
878 if (!parent)
879 return -ENOENT;
880
881 mutex_lock(&parent->i_mutex);
882 if (!S_ISDIR(parent->i_mode))
883 goto unlock;
884
885 err = -ENOENT;
886 dir = d_find_alias(parent);
887 if (!dir)
888 goto unlock;
889
890 entry = d_lookup(dir, name);
891 dput(dir);
892 if (!entry)
893 goto unlock;
894
895 fuse_invalidate_attr(parent);
896 fuse_invalidate_entry(entry);
897 dput(entry);
898 err = 0;
899
900 unlock:
901 mutex_unlock(&parent->i_mutex);
902 iput(parent);
903 return err;
904 }
905
906 /*
907 * Calling into a user-controlled filesystem gives the filesystem
908 * daemon ptrace-like capabilities over the requester process. This
909 * means, that the filesystem daemon is able to record the exact
910 * filesystem operations performed, and can also control the behavior
911 * of the requester process in otherwise impossible ways. For example
912 * it can delay the operation for arbitrary length of time allowing
913 * DoS against the requester.
914 *
915 * For this reason only those processes can call into the filesystem,
916 * for which the owner of the mount has ptrace privilege. This
917 * excludes processes started by other users, suid or sgid processes.
918 */
fuse_allow_task(struct fuse_conn * fc,struct task_struct * task)919 int fuse_allow_task(struct fuse_conn *fc, struct task_struct *task)
920 {
921 const struct cred *cred;
922 int ret;
923
924 if (fc->flags & FUSE_ALLOW_OTHER)
925 return 1;
926
927 rcu_read_lock();
928 ret = 0;
929 cred = __task_cred(task);
930 if (cred->euid == fc->user_id &&
931 cred->suid == fc->user_id &&
932 cred->uid == fc->user_id &&
933 cred->egid == fc->group_id &&
934 cred->sgid == fc->group_id &&
935 cred->gid == fc->group_id)
936 ret = 1;
937 rcu_read_unlock();
938
939 return ret;
940 }
941
fuse_access(struct inode * inode,int mask)942 static int fuse_access(struct inode *inode, int mask)
943 {
944 struct fuse_conn *fc = get_fuse_conn(inode);
945 struct fuse_req *req;
946 struct fuse_access_in inarg;
947 int err;
948
949 if (fc->no_access)
950 return 0;
951
952 req = fuse_get_req(fc);
953 if (IS_ERR(req))
954 return PTR_ERR(req);
955
956 memset(&inarg, 0, sizeof(inarg));
957 inarg.mask = mask & (MAY_READ | MAY_WRITE | MAY_EXEC);
958 req->in.h.opcode = FUSE_ACCESS;
959 req->in.h.nodeid = get_node_id(inode);
960 req->in.numargs = 1;
961 req->in.args[0].size = sizeof(inarg);
962 req->in.args[0].value = &inarg;
963 fuse_request_send(fc, req);
964 err = req->out.h.error;
965 fuse_put_request(fc, req);
966 if (err == -ENOSYS) {
967 fc->no_access = 1;
968 err = 0;
969 }
970 return err;
971 }
972
fuse_perm_getattr(struct inode * inode,int flags)973 static int fuse_perm_getattr(struct inode *inode, int flags)
974 {
975 if (flags & IPERM_FLAG_RCU)
976 return -ECHILD;
977
978 return fuse_do_getattr(inode, NULL, NULL);
979 }
980
981 /*
982 * Check permission. The two basic access models of FUSE are:
983 *
984 * 1) Local access checking ('default_permissions' mount option) based
985 * on file mode. This is the plain old disk filesystem permission
986 * modell.
987 *
988 * 2) "Remote" access checking, where server is responsible for
989 * checking permission in each inode operation. An exception to this
990 * is if ->permission() was invoked from sys_access() in which case an
991 * access request is sent. Execute permission is still checked
992 * locally based on file mode.
993 */
fuse_permission(struct inode * inode,int mask,unsigned int flags)994 static int fuse_permission(struct inode *inode, int mask, unsigned int flags)
995 {
996 struct fuse_conn *fc = get_fuse_conn(inode);
997 bool refreshed = false;
998 int err = 0;
999
1000 if (!fuse_allow_task(fc, current))
1001 return -EACCES;
1002
1003 /*
1004 * If attributes are needed, refresh them before proceeding
1005 */
1006 if ((fc->flags & FUSE_DEFAULT_PERMISSIONS) ||
1007 ((mask & MAY_EXEC) && S_ISREG(inode->i_mode))) {
1008 struct fuse_inode *fi = get_fuse_inode(inode);
1009
1010 if (fi->i_time < get_jiffies_64()) {
1011 refreshed = true;
1012
1013 err = fuse_perm_getattr(inode, flags);
1014 if (err)
1015 return err;
1016 }
1017 }
1018
1019 if (fc->flags & FUSE_DEFAULT_PERMISSIONS) {
1020 err = generic_permission(inode, mask, flags, NULL);
1021
1022 /* If permission is denied, try to refresh file
1023 attributes. This is also needed, because the root
1024 node will at first have no permissions */
1025 if (err == -EACCES && !refreshed) {
1026 err = fuse_perm_getattr(inode, flags);
1027 if (!err)
1028 err = generic_permission(inode, mask,
1029 flags, NULL);
1030 }
1031
1032 /* Note: the opposite of the above test does not
1033 exist. So if permissions are revoked this won't be
1034 noticed immediately, only after the attribute
1035 timeout has expired */
1036 } else if (mask & (MAY_ACCESS | MAY_CHDIR)) {
1037 if (flags & IPERM_FLAG_RCU)
1038 return -ECHILD;
1039
1040 err = fuse_access(inode, mask);
1041 } else if ((mask & MAY_EXEC) && S_ISREG(inode->i_mode)) {
1042 if (!(inode->i_mode & S_IXUGO)) {
1043 if (refreshed)
1044 return -EACCES;
1045
1046 err = fuse_perm_getattr(inode, flags);
1047 if (!err && !(inode->i_mode & S_IXUGO))
1048 return -EACCES;
1049 }
1050 }
1051 return err;
1052 }
1053
parse_dirfile(char * buf,size_t nbytes,struct file * file,void * dstbuf,filldir_t filldir)1054 static int parse_dirfile(char *buf, size_t nbytes, struct file *file,
1055 void *dstbuf, filldir_t filldir)
1056 {
1057 while (nbytes >= FUSE_NAME_OFFSET) {
1058 struct fuse_dirent *dirent = (struct fuse_dirent *) buf;
1059 size_t reclen = FUSE_DIRENT_SIZE(dirent);
1060 int over;
1061 if (!dirent->namelen || dirent->namelen > FUSE_NAME_MAX)
1062 return -EIO;
1063 if (reclen > nbytes)
1064 break;
1065
1066 over = filldir(dstbuf, dirent->name, dirent->namelen,
1067 file->f_pos, dirent->ino, dirent->type);
1068 if (over)
1069 break;
1070
1071 buf += reclen;
1072 nbytes -= reclen;
1073 file->f_pos = dirent->off;
1074 }
1075
1076 return 0;
1077 }
1078
fuse_readdir(struct file * file,void * dstbuf,filldir_t filldir)1079 static int fuse_readdir(struct file *file, void *dstbuf, filldir_t filldir)
1080 {
1081 int err;
1082 size_t nbytes;
1083 struct page *page;
1084 struct inode *inode = file->f_path.dentry->d_inode;
1085 struct fuse_conn *fc = get_fuse_conn(inode);
1086 struct fuse_req *req;
1087
1088 if (is_bad_inode(inode))
1089 return -EIO;
1090
1091 req = fuse_get_req(fc);
1092 if (IS_ERR(req))
1093 return PTR_ERR(req);
1094
1095 page = alloc_page(GFP_KERNEL);
1096 if (!page) {
1097 fuse_put_request(fc, req);
1098 return -ENOMEM;
1099 }
1100 req->out.argpages = 1;
1101 req->num_pages = 1;
1102 req->pages[0] = page;
1103 fuse_read_fill(req, file, file->f_pos, PAGE_SIZE, FUSE_READDIR);
1104 fuse_request_send(fc, req);
1105 nbytes = req->out.args[0].size;
1106 err = req->out.h.error;
1107 fuse_put_request(fc, req);
1108 if (!err)
1109 err = parse_dirfile(page_address(page), nbytes, file, dstbuf,
1110 filldir);
1111
1112 __free_page(page);
1113 fuse_invalidate_attr(inode); /* atime changed */
1114 return err;
1115 }
1116
read_link(struct dentry * dentry)1117 static char *read_link(struct dentry *dentry)
1118 {
1119 struct inode *inode = dentry->d_inode;
1120 struct fuse_conn *fc = get_fuse_conn(inode);
1121 struct fuse_req *req = fuse_get_req(fc);
1122 char *link;
1123
1124 if (IS_ERR(req))
1125 return ERR_CAST(req);
1126
1127 link = (char *) __get_free_page(GFP_KERNEL);
1128 if (!link) {
1129 link = ERR_PTR(-ENOMEM);
1130 goto out;
1131 }
1132 req->in.h.opcode = FUSE_READLINK;
1133 req->in.h.nodeid = get_node_id(inode);
1134 req->out.argvar = 1;
1135 req->out.numargs = 1;
1136 req->out.args[0].size = PAGE_SIZE - 1;
1137 req->out.args[0].value = link;
1138 fuse_request_send(fc, req);
1139 if (req->out.h.error) {
1140 free_page((unsigned long) link);
1141 link = ERR_PTR(req->out.h.error);
1142 } else
1143 link[req->out.args[0].size] = '\0';
1144 out:
1145 fuse_put_request(fc, req);
1146 fuse_invalidate_attr(inode); /* atime changed */
1147 return link;
1148 }
1149
free_link(char * link)1150 static void free_link(char *link)
1151 {
1152 if (!IS_ERR(link))
1153 free_page((unsigned long) link);
1154 }
1155
fuse_follow_link(struct dentry * dentry,struct nameidata * nd)1156 static void *fuse_follow_link(struct dentry *dentry, struct nameidata *nd)
1157 {
1158 nd_set_link(nd, read_link(dentry));
1159 return NULL;
1160 }
1161
fuse_put_link(struct dentry * dentry,struct nameidata * nd,void * c)1162 static void fuse_put_link(struct dentry *dentry, struct nameidata *nd, void *c)
1163 {
1164 free_link(nd_get_link(nd));
1165 }
1166
fuse_dir_open(struct inode * inode,struct file * file)1167 static int fuse_dir_open(struct inode *inode, struct file *file)
1168 {
1169 return fuse_open_common(inode, file, true);
1170 }
1171
fuse_dir_release(struct inode * inode,struct file * file)1172 static int fuse_dir_release(struct inode *inode, struct file *file)
1173 {
1174 fuse_release_common(file, FUSE_RELEASEDIR);
1175
1176 return 0;
1177 }
1178
fuse_dir_fsync(struct file * file,int datasync)1179 static int fuse_dir_fsync(struct file *file, int datasync)
1180 {
1181 return fuse_fsync_common(file, datasync, 1);
1182 }
1183
update_mtime(unsigned ivalid)1184 static bool update_mtime(unsigned ivalid)
1185 {
1186 /* Always update if mtime is explicitly set */
1187 if (ivalid & ATTR_MTIME_SET)
1188 return true;
1189
1190 /* If it's an open(O_TRUNC) or an ftruncate(), don't update */
1191 if ((ivalid & ATTR_SIZE) && (ivalid & (ATTR_OPEN | ATTR_FILE)))
1192 return false;
1193
1194 /* In all other cases update */
1195 return true;
1196 }
1197
iattr_to_fattr(struct iattr * iattr,struct fuse_setattr_in * arg)1198 static void iattr_to_fattr(struct iattr *iattr, struct fuse_setattr_in *arg)
1199 {
1200 unsigned ivalid = iattr->ia_valid;
1201
1202 if (ivalid & ATTR_MODE)
1203 arg->valid |= FATTR_MODE, arg->mode = iattr->ia_mode;
1204 if (ivalid & ATTR_UID)
1205 arg->valid |= FATTR_UID, arg->uid = iattr->ia_uid;
1206 if (ivalid & ATTR_GID)
1207 arg->valid |= FATTR_GID, arg->gid = iattr->ia_gid;
1208 if (ivalid & ATTR_SIZE)
1209 arg->valid |= FATTR_SIZE, arg->size = iattr->ia_size;
1210 if (ivalid & ATTR_ATIME) {
1211 arg->valid |= FATTR_ATIME;
1212 arg->atime = iattr->ia_atime.tv_sec;
1213 arg->atimensec = iattr->ia_atime.tv_nsec;
1214 if (!(ivalid & ATTR_ATIME_SET))
1215 arg->valid |= FATTR_ATIME_NOW;
1216 }
1217 if ((ivalid & ATTR_MTIME) && update_mtime(ivalid)) {
1218 arg->valid |= FATTR_MTIME;
1219 arg->mtime = iattr->ia_mtime.tv_sec;
1220 arg->mtimensec = iattr->ia_mtime.tv_nsec;
1221 if (!(ivalid & ATTR_MTIME_SET))
1222 arg->valid |= FATTR_MTIME_NOW;
1223 }
1224 }
1225
1226 /*
1227 * Prevent concurrent writepages on inode
1228 *
1229 * This is done by adding a negative bias to the inode write counter
1230 * and waiting for all pending writes to finish.
1231 */
fuse_set_nowrite(struct inode * inode)1232 void fuse_set_nowrite(struct inode *inode)
1233 {
1234 struct fuse_conn *fc = get_fuse_conn(inode);
1235 struct fuse_inode *fi = get_fuse_inode(inode);
1236
1237 BUG_ON(!mutex_is_locked(&inode->i_mutex));
1238
1239 spin_lock(&fc->lock);
1240 BUG_ON(fi->writectr < 0);
1241 fi->writectr += FUSE_NOWRITE;
1242 spin_unlock(&fc->lock);
1243 wait_event(fi->page_waitq, fi->writectr == FUSE_NOWRITE);
1244 }
1245
1246 /*
1247 * Allow writepages on inode
1248 *
1249 * Remove the bias from the writecounter and send any queued
1250 * writepages.
1251 */
__fuse_release_nowrite(struct inode * inode)1252 static void __fuse_release_nowrite(struct inode *inode)
1253 {
1254 struct fuse_inode *fi = get_fuse_inode(inode);
1255
1256 BUG_ON(fi->writectr != FUSE_NOWRITE);
1257 fi->writectr = 0;
1258 fuse_flush_writepages(inode);
1259 }
1260
fuse_release_nowrite(struct inode * inode)1261 void fuse_release_nowrite(struct inode *inode)
1262 {
1263 struct fuse_conn *fc = get_fuse_conn(inode);
1264
1265 spin_lock(&fc->lock);
1266 __fuse_release_nowrite(inode);
1267 spin_unlock(&fc->lock);
1268 }
1269
1270 /*
1271 * Set attributes, and at the same time refresh them.
1272 *
1273 * Truncation is slightly complicated, because the 'truncate' request
1274 * may fail, in which case we don't want to touch the mapping.
1275 * vmtruncate() doesn't allow for this case, so do the rlimit checking
1276 * and the actual truncation by hand.
1277 */
fuse_do_setattr(struct dentry * entry,struct iattr * attr,struct file * file)1278 static int fuse_do_setattr(struct dentry *entry, struct iattr *attr,
1279 struct file *file)
1280 {
1281 struct inode *inode = entry->d_inode;
1282 struct fuse_conn *fc = get_fuse_conn(inode);
1283 struct fuse_req *req;
1284 struct fuse_setattr_in inarg;
1285 struct fuse_attr_out outarg;
1286 bool is_truncate = false;
1287 loff_t oldsize;
1288 int err;
1289
1290 if (!fuse_allow_task(fc, current))
1291 return -EACCES;
1292
1293 if (!(fc->flags & FUSE_DEFAULT_PERMISSIONS))
1294 attr->ia_valid |= ATTR_FORCE;
1295
1296 err = inode_change_ok(inode, attr);
1297 if (err)
1298 return err;
1299
1300 if (attr->ia_valid & ATTR_OPEN) {
1301 if (fc->atomic_o_trunc)
1302 return 0;
1303 file = NULL;
1304 }
1305
1306 if (attr->ia_valid & ATTR_SIZE)
1307 is_truncate = true;
1308
1309 req = fuse_get_req(fc);
1310 if (IS_ERR(req))
1311 return PTR_ERR(req);
1312
1313 if (is_truncate)
1314 fuse_set_nowrite(inode);
1315
1316 memset(&inarg, 0, sizeof(inarg));
1317 memset(&outarg, 0, sizeof(outarg));
1318 iattr_to_fattr(attr, &inarg);
1319 if (file) {
1320 struct fuse_file *ff = file->private_data;
1321 inarg.valid |= FATTR_FH;
1322 inarg.fh = ff->fh;
1323 }
1324 if (attr->ia_valid & ATTR_SIZE) {
1325 /* For mandatory locking in truncate */
1326 inarg.valid |= FATTR_LOCKOWNER;
1327 inarg.lock_owner = fuse_lock_owner_id(fc, current->files);
1328 }
1329 req->in.h.opcode = FUSE_SETATTR;
1330 req->in.h.nodeid = get_node_id(inode);
1331 req->in.numargs = 1;
1332 req->in.args[0].size = sizeof(inarg);
1333 req->in.args[0].value = &inarg;
1334 req->out.numargs = 1;
1335 if (fc->minor < 9)
1336 req->out.args[0].size = FUSE_COMPAT_ATTR_OUT_SIZE;
1337 else
1338 req->out.args[0].size = sizeof(outarg);
1339 req->out.args[0].value = &outarg;
1340 fuse_request_send(fc, req);
1341 err = req->out.h.error;
1342 fuse_put_request(fc, req);
1343 if (err) {
1344 if (err == -EINTR)
1345 fuse_invalidate_attr(inode);
1346 goto error;
1347 }
1348
1349 if ((inode->i_mode ^ outarg.attr.mode) & S_IFMT) {
1350 make_bad_inode(inode);
1351 err = -EIO;
1352 goto error;
1353 }
1354
1355 spin_lock(&fc->lock);
1356 fuse_change_attributes_common(inode, &outarg.attr,
1357 attr_timeout(&outarg));
1358 oldsize = inode->i_size;
1359 i_size_write(inode, outarg.attr.size);
1360
1361 if (is_truncate) {
1362 /* NOTE: this may release/reacquire fc->lock */
1363 __fuse_release_nowrite(inode);
1364 }
1365 spin_unlock(&fc->lock);
1366
1367 /*
1368 * Only call invalidate_inode_pages2() after removing
1369 * FUSE_NOWRITE, otherwise fuse_launder_page() would deadlock.
1370 */
1371 if (S_ISREG(inode->i_mode) && oldsize != outarg.attr.size) {
1372 truncate_pagecache(inode, oldsize, outarg.attr.size);
1373 invalidate_inode_pages2(inode->i_mapping);
1374 }
1375
1376 return 0;
1377
1378 error:
1379 if (is_truncate)
1380 fuse_release_nowrite(inode);
1381
1382 return err;
1383 }
1384
fuse_setattr(struct dentry * entry,struct iattr * attr)1385 static int fuse_setattr(struct dentry *entry, struct iattr *attr)
1386 {
1387 if (attr->ia_valid & ATTR_FILE)
1388 return fuse_do_setattr(entry, attr, attr->ia_file);
1389 else
1390 return fuse_do_setattr(entry, attr, NULL);
1391 }
1392
fuse_getattr(struct vfsmount * mnt,struct dentry * entry,struct kstat * stat)1393 static int fuse_getattr(struct vfsmount *mnt, struct dentry *entry,
1394 struct kstat *stat)
1395 {
1396 struct inode *inode = entry->d_inode;
1397 struct fuse_conn *fc = get_fuse_conn(inode);
1398
1399 if (!fuse_allow_task(fc, current))
1400 return -EACCES;
1401
1402 return fuse_update_attributes(inode, stat, NULL, NULL);
1403 }
1404
fuse_setxattr(struct dentry * entry,const char * name,const void * value,size_t size,int flags)1405 static int fuse_setxattr(struct dentry *entry, const char *name,
1406 const void *value, size_t size, int flags)
1407 {
1408 struct inode *inode = entry->d_inode;
1409 struct fuse_conn *fc = get_fuse_conn(inode);
1410 struct fuse_req *req;
1411 struct fuse_setxattr_in inarg;
1412 int err;
1413
1414 if (fc->no_setxattr)
1415 return -EOPNOTSUPP;
1416
1417 req = fuse_get_req(fc);
1418 if (IS_ERR(req))
1419 return PTR_ERR(req);
1420
1421 memset(&inarg, 0, sizeof(inarg));
1422 inarg.size = size;
1423 inarg.flags = flags;
1424 req->in.h.opcode = FUSE_SETXATTR;
1425 req->in.h.nodeid = get_node_id(inode);
1426 req->in.numargs = 3;
1427 req->in.args[0].size = sizeof(inarg);
1428 req->in.args[0].value = &inarg;
1429 req->in.args[1].size = strlen(name) + 1;
1430 req->in.args[1].value = name;
1431 req->in.args[2].size = size;
1432 req->in.args[2].value = value;
1433 fuse_request_send(fc, req);
1434 err = req->out.h.error;
1435 fuse_put_request(fc, req);
1436 if (err == -ENOSYS) {
1437 fc->no_setxattr = 1;
1438 err = -EOPNOTSUPP;
1439 }
1440 return err;
1441 }
1442
fuse_getxattr(struct dentry * entry,const char * name,void * value,size_t size)1443 static ssize_t fuse_getxattr(struct dentry *entry, const char *name,
1444 void *value, size_t size)
1445 {
1446 struct inode *inode = entry->d_inode;
1447 struct fuse_conn *fc = get_fuse_conn(inode);
1448 struct fuse_req *req;
1449 struct fuse_getxattr_in inarg;
1450 struct fuse_getxattr_out outarg;
1451 ssize_t ret;
1452
1453 if (fc->no_getxattr)
1454 return -EOPNOTSUPP;
1455
1456 req = fuse_get_req(fc);
1457 if (IS_ERR(req))
1458 return PTR_ERR(req);
1459
1460 memset(&inarg, 0, sizeof(inarg));
1461 inarg.size = size;
1462 req->in.h.opcode = FUSE_GETXATTR;
1463 req->in.h.nodeid = get_node_id(inode);
1464 req->in.numargs = 2;
1465 req->in.args[0].size = sizeof(inarg);
1466 req->in.args[0].value = &inarg;
1467 req->in.args[1].size = strlen(name) + 1;
1468 req->in.args[1].value = name;
1469 /* This is really two different operations rolled into one */
1470 req->out.numargs = 1;
1471 if (size) {
1472 req->out.argvar = 1;
1473 req->out.args[0].size = size;
1474 req->out.args[0].value = value;
1475 } else {
1476 req->out.args[0].size = sizeof(outarg);
1477 req->out.args[0].value = &outarg;
1478 }
1479 fuse_request_send(fc, req);
1480 ret = req->out.h.error;
1481 if (!ret)
1482 ret = size ? req->out.args[0].size : outarg.size;
1483 else {
1484 if (ret == -ENOSYS) {
1485 fc->no_getxattr = 1;
1486 ret = -EOPNOTSUPP;
1487 }
1488 }
1489 fuse_put_request(fc, req);
1490 return ret;
1491 }
1492
fuse_listxattr(struct dentry * entry,char * list,size_t size)1493 static ssize_t fuse_listxattr(struct dentry *entry, char *list, size_t size)
1494 {
1495 struct inode *inode = entry->d_inode;
1496 struct fuse_conn *fc = get_fuse_conn(inode);
1497 struct fuse_req *req;
1498 struct fuse_getxattr_in inarg;
1499 struct fuse_getxattr_out outarg;
1500 ssize_t ret;
1501
1502 if (!fuse_allow_task(fc, current))
1503 return -EACCES;
1504
1505 if (fc->no_listxattr)
1506 return -EOPNOTSUPP;
1507
1508 req = fuse_get_req(fc);
1509 if (IS_ERR(req))
1510 return PTR_ERR(req);
1511
1512 memset(&inarg, 0, sizeof(inarg));
1513 inarg.size = size;
1514 req->in.h.opcode = FUSE_LISTXATTR;
1515 req->in.h.nodeid = get_node_id(inode);
1516 req->in.numargs = 1;
1517 req->in.args[0].size = sizeof(inarg);
1518 req->in.args[0].value = &inarg;
1519 /* This is really two different operations rolled into one */
1520 req->out.numargs = 1;
1521 if (size) {
1522 req->out.argvar = 1;
1523 req->out.args[0].size = size;
1524 req->out.args[0].value = list;
1525 } else {
1526 req->out.args[0].size = sizeof(outarg);
1527 req->out.args[0].value = &outarg;
1528 }
1529 fuse_request_send(fc, req);
1530 ret = req->out.h.error;
1531 if (!ret)
1532 ret = size ? req->out.args[0].size : outarg.size;
1533 else {
1534 if (ret == -ENOSYS) {
1535 fc->no_listxattr = 1;
1536 ret = -EOPNOTSUPP;
1537 }
1538 }
1539 fuse_put_request(fc, req);
1540 return ret;
1541 }
1542
fuse_removexattr(struct dentry * entry,const char * name)1543 static int fuse_removexattr(struct dentry *entry, const char *name)
1544 {
1545 struct inode *inode = entry->d_inode;
1546 struct fuse_conn *fc = get_fuse_conn(inode);
1547 struct fuse_req *req;
1548 int err;
1549
1550 if (fc->no_removexattr)
1551 return -EOPNOTSUPP;
1552
1553 req = fuse_get_req(fc);
1554 if (IS_ERR(req))
1555 return PTR_ERR(req);
1556
1557 req->in.h.opcode = FUSE_REMOVEXATTR;
1558 req->in.h.nodeid = get_node_id(inode);
1559 req->in.numargs = 1;
1560 req->in.args[0].size = strlen(name) + 1;
1561 req->in.args[0].value = name;
1562 fuse_request_send(fc, req);
1563 err = req->out.h.error;
1564 fuse_put_request(fc, req);
1565 if (err == -ENOSYS) {
1566 fc->no_removexattr = 1;
1567 err = -EOPNOTSUPP;
1568 }
1569 return err;
1570 }
1571
1572 static const struct inode_operations fuse_dir_inode_operations = {
1573 .lookup = fuse_lookup,
1574 .mkdir = fuse_mkdir,
1575 .symlink = fuse_symlink,
1576 .unlink = fuse_unlink,
1577 .rmdir = fuse_rmdir,
1578 .rename = fuse_rename,
1579 .link = fuse_link,
1580 .setattr = fuse_setattr,
1581 .create = fuse_create,
1582 .mknod = fuse_mknod,
1583 .permission = fuse_permission,
1584 .getattr = fuse_getattr,
1585 .setxattr = fuse_setxattr,
1586 .getxattr = fuse_getxattr,
1587 .listxattr = fuse_listxattr,
1588 .removexattr = fuse_removexattr,
1589 };
1590
1591 static const struct file_operations fuse_dir_operations = {
1592 .llseek = generic_file_llseek,
1593 .read = generic_read_dir,
1594 .readdir = fuse_readdir,
1595 .open = fuse_dir_open,
1596 .release = fuse_dir_release,
1597 .fsync = fuse_dir_fsync,
1598 };
1599
1600 static const struct inode_operations fuse_common_inode_operations = {
1601 .setattr = fuse_setattr,
1602 .permission = fuse_permission,
1603 .getattr = fuse_getattr,
1604 .setxattr = fuse_setxattr,
1605 .getxattr = fuse_getxattr,
1606 .listxattr = fuse_listxattr,
1607 .removexattr = fuse_removexattr,
1608 };
1609
1610 static const struct inode_operations fuse_symlink_inode_operations = {
1611 .setattr = fuse_setattr,
1612 .follow_link = fuse_follow_link,
1613 .put_link = fuse_put_link,
1614 .readlink = generic_readlink,
1615 .getattr = fuse_getattr,
1616 .setxattr = fuse_setxattr,
1617 .getxattr = fuse_getxattr,
1618 .listxattr = fuse_listxattr,
1619 .removexattr = fuse_removexattr,
1620 };
1621
fuse_init_common(struct inode * inode)1622 void fuse_init_common(struct inode *inode)
1623 {
1624 inode->i_op = &fuse_common_inode_operations;
1625 }
1626
fuse_init_dir(struct inode * inode)1627 void fuse_init_dir(struct inode *inode)
1628 {
1629 inode->i_op = &fuse_dir_inode_operations;
1630 inode->i_fop = &fuse_dir_operations;
1631 }
1632
fuse_init_symlink(struct inode * inode)1633 void fuse_init_symlink(struct inode *inode)
1634 {
1635 inode->i_op = &fuse_symlink_inode_operations;
1636 }
1637