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Merge branch 'for-linus' of master.kernel.org:/pub/scm/linux/kernel/git/roland/infiniband
[mirror_ubuntu-zesty-kernel.git] / fs / fuse / dir.c
1 /*
2 FUSE: Filesystem in Userspace
3 Copyright (C) 2001-2005 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/gfp.h>
14 #include <linux/sched.h>
15 #include <linux/namei.h>
16 #include <linux/mount.h>
17
18 static inline unsigned long time_to_jiffies(unsigned long sec,
19 unsigned long nsec)
20 {
21 struct timespec ts = {sec, nsec};
22 return jiffies + timespec_to_jiffies(&ts);
23 }
24
25 static void fuse_lookup_init(struct fuse_req *req, struct inode *dir,
26 struct dentry *entry,
27 struct fuse_entry_out *outarg)
28 {
29 req->in.h.opcode = FUSE_LOOKUP;
30 req->in.h.nodeid = get_node_id(dir);
31 req->inode = dir;
32 req->in.numargs = 1;
33 req->in.args[0].size = entry->d_name.len + 1;
34 req->in.args[0].value = entry->d_name.name;
35 req->out.numargs = 1;
36 req->out.args[0].size = sizeof(struct fuse_entry_out);
37 req->out.args[0].value = outarg;
38 }
39
40 static int fuse_dentry_revalidate(struct dentry *entry, struct nameidata *nd)
41 {
42 if (!entry->d_inode || is_bad_inode(entry->d_inode))
43 return 0;
44 else if (time_after(jiffies, entry->d_time)) {
45 int err;
46 struct fuse_entry_out outarg;
47 struct inode *inode = entry->d_inode;
48 struct fuse_inode *fi = get_fuse_inode(inode);
49 struct fuse_conn *fc = get_fuse_conn(inode);
50 struct fuse_req *req = fuse_get_request(fc);
51 if (!req)
52 return 0;
53
54 fuse_lookup_init(req, entry->d_parent->d_inode, entry, &outarg);
55 request_send(fc, req);
56 err = req->out.h.error;
57 if (!err) {
58 if (outarg.nodeid != get_node_id(inode)) {
59 fuse_send_forget(fc, req, outarg.nodeid, 1);
60 return 0;
61 }
62 fi->nlookup ++;
63 }
64 fuse_put_request(fc, req);
65 if (err || (outarg.attr.mode ^ inode->i_mode) & S_IFMT)
66 return 0;
67
68 fuse_change_attributes(inode, &outarg.attr);
69 entry->d_time = time_to_jiffies(outarg.entry_valid,
70 outarg.entry_valid_nsec);
71 fi->i_time = time_to_jiffies(outarg.attr_valid,
72 outarg.attr_valid_nsec);
73 }
74 return 1;
75 }
76
77 static struct dentry_operations fuse_dentry_operations = {
78 .d_revalidate = fuse_dentry_revalidate,
79 };
80
81 static int fuse_lookup_iget(struct inode *dir, struct dentry *entry,
82 struct inode **inodep)
83 {
84 int err;
85 struct fuse_entry_out outarg;
86 struct inode *inode = NULL;
87 struct fuse_conn *fc = get_fuse_conn(dir);
88 struct fuse_req *req;
89
90 if (entry->d_name.len > FUSE_NAME_MAX)
91 return -ENAMETOOLONG;
92
93 req = fuse_get_request(fc);
94 if (!req)
95 return -EINTR;
96
97 fuse_lookup_init(req, dir, entry, &outarg);
98 request_send(fc, req);
99 err = req->out.h.error;
100 if (!err && (!outarg.nodeid || outarg.nodeid == FUSE_ROOT_ID))
101 err = -EIO;
102 if (!err) {
103 inode = fuse_iget(dir->i_sb, outarg.nodeid, outarg.generation,
104 &outarg.attr);
105 if (!inode) {
106 fuse_send_forget(fc, req, outarg.nodeid, 1);
107 return -ENOMEM;
108 }
109 }
110 fuse_put_request(fc, req);
111 if (err && err != -ENOENT)
112 return err;
113
114 if (inode) {
115 struct fuse_inode *fi = get_fuse_inode(inode);
116 entry->d_time = time_to_jiffies(outarg.entry_valid,
117 outarg.entry_valid_nsec);
118 fi->i_time = time_to_jiffies(outarg.attr_valid,
119 outarg.attr_valid_nsec);
120 }
121
122 entry->d_op = &fuse_dentry_operations;
123 *inodep = inode;
124 return 0;
125 }
126
127 void fuse_invalidate_attr(struct inode *inode)
128 {
129 get_fuse_inode(inode)->i_time = jiffies - 1;
130 }
131
132 static void fuse_invalidate_entry(struct dentry *entry)
133 {
134 d_invalidate(entry);
135 entry->d_time = jiffies - 1;
136 }
137
138 static int fuse_create_open(struct inode *dir, struct dentry *entry, int mode,
139 struct nameidata *nd)
140 {
141 int err;
142 struct inode *inode;
143 struct fuse_conn *fc = get_fuse_conn(dir);
144 struct fuse_req *req;
145 struct fuse_open_in inarg;
146 struct fuse_open_out outopen;
147 struct fuse_entry_out outentry;
148 struct fuse_inode *fi;
149 struct fuse_file *ff;
150 struct file *file;
151 int flags = nd->intent.open.flags - 1;
152
153 err = -ENOSYS;
154 if (fc->no_create)
155 goto out;
156
157 err = -ENAMETOOLONG;
158 if (entry->d_name.len > FUSE_NAME_MAX)
159 goto out;
160
161 err = -EINTR;
162 req = fuse_get_request(fc);
163 if (!req)
164 goto out;
165
166 ff = fuse_file_alloc();
167 if (!ff)
168 goto out_put_request;
169
170 flags &= ~O_NOCTTY;
171 memset(&inarg, 0, sizeof(inarg));
172 inarg.flags = flags;
173 inarg.mode = mode;
174 req->in.h.opcode = FUSE_CREATE;
175 req->in.h.nodeid = get_node_id(dir);
176 req->inode = dir;
177 req->in.numargs = 2;
178 req->in.args[0].size = sizeof(inarg);
179 req->in.args[0].value = &inarg;
180 req->in.args[1].size = entry->d_name.len + 1;
181 req->in.args[1].value = entry->d_name.name;
182 req->out.numargs = 2;
183 req->out.args[0].size = sizeof(outentry);
184 req->out.args[0].value = &outentry;
185 req->out.args[1].size = sizeof(outopen);
186 req->out.args[1].value = &outopen;
187 request_send(fc, req);
188 err = req->out.h.error;
189 if (err) {
190 if (err == -ENOSYS)
191 fc->no_create = 1;
192 goto out_free_ff;
193 }
194
195 err = -EIO;
196 if (!S_ISREG(outentry.attr.mode))
197 goto out_free_ff;
198
199 inode = fuse_iget(dir->i_sb, outentry.nodeid, outentry.generation,
200 &outentry.attr);
201 err = -ENOMEM;
202 if (!inode) {
203 flags &= ~(O_CREAT | O_EXCL | O_TRUNC);
204 ff->fh = outopen.fh;
205 fuse_send_release(fc, ff, outentry.nodeid, NULL, flags, 0);
206 goto out_put_request;
207 }
208 fuse_put_request(fc, req);
209 entry->d_time = time_to_jiffies(outentry.entry_valid,
210 outentry.entry_valid_nsec);
211 fi = get_fuse_inode(inode);
212 fi->i_time = time_to_jiffies(outentry.attr_valid,
213 outentry.attr_valid_nsec);
214
215 d_instantiate(entry, inode);
216 file = lookup_instantiate_filp(nd, entry, generic_file_open);
217 if (IS_ERR(file)) {
218 ff->fh = outopen.fh;
219 fuse_send_release(fc, ff, outentry.nodeid, inode, flags, 0);
220 return PTR_ERR(file);
221 }
222 fuse_finish_open(inode, file, ff, &outopen);
223 return 0;
224
225 out_free_ff:
226 fuse_file_free(ff);
227 out_put_request:
228 fuse_put_request(fc, req);
229 out:
230 return err;
231 }
232
233 static int create_new_entry(struct fuse_conn *fc, struct fuse_req *req,
234 struct inode *dir, struct dentry *entry,
235 int mode)
236 {
237 struct fuse_entry_out outarg;
238 struct inode *inode;
239 struct fuse_inode *fi;
240 int err;
241
242 req->in.h.nodeid = get_node_id(dir);
243 req->inode = dir;
244 req->out.numargs = 1;
245 req->out.args[0].size = sizeof(outarg);
246 req->out.args[0].value = &outarg;
247 request_send(fc, req);
248 err = req->out.h.error;
249 if (err) {
250 fuse_put_request(fc, req);
251 return err;
252 }
253 if (!outarg.nodeid || outarg.nodeid == FUSE_ROOT_ID) {
254 fuse_put_request(fc, req);
255 return -EIO;
256 }
257 inode = fuse_iget(dir->i_sb, outarg.nodeid, outarg.generation,
258 &outarg.attr);
259 if (!inode) {
260 fuse_send_forget(fc, req, outarg.nodeid, 1);
261 return -ENOMEM;
262 }
263 fuse_put_request(fc, req);
264
265 /* Don't allow userspace to do really stupid things... */
266 if ((inode->i_mode ^ mode) & S_IFMT) {
267 iput(inode);
268 return -EIO;
269 }
270
271 entry->d_time = time_to_jiffies(outarg.entry_valid,
272 outarg.entry_valid_nsec);
273
274 fi = get_fuse_inode(inode);
275 fi->i_time = time_to_jiffies(outarg.attr_valid,
276 outarg.attr_valid_nsec);
277
278 d_instantiate(entry, inode);
279 fuse_invalidate_attr(dir);
280 return 0;
281 }
282
283 static int fuse_mknod(struct inode *dir, struct dentry *entry, int mode,
284 dev_t rdev)
285 {
286 struct fuse_mknod_in inarg;
287 struct fuse_conn *fc = get_fuse_conn(dir);
288 struct fuse_req *req = fuse_get_request(fc);
289 if (!req)
290 return -EINTR;
291
292 memset(&inarg, 0, sizeof(inarg));
293 inarg.mode = mode;
294 inarg.rdev = new_encode_dev(rdev);
295 req->in.h.opcode = FUSE_MKNOD;
296 req->in.numargs = 2;
297 req->in.args[0].size = sizeof(inarg);
298 req->in.args[0].value = &inarg;
299 req->in.args[1].size = entry->d_name.len + 1;
300 req->in.args[1].value = entry->d_name.name;
301 return create_new_entry(fc, req, dir, entry, mode);
302 }
303
304 static int fuse_create(struct inode *dir, struct dentry *entry, int mode,
305 struct nameidata *nd)
306 {
307 if (nd && (nd->flags & LOOKUP_CREATE)) {
308 int err = fuse_create_open(dir, entry, mode, nd);
309 if (err != -ENOSYS)
310 return err;
311 /* Fall back on mknod */
312 }
313 return fuse_mknod(dir, entry, mode, 0);
314 }
315
316 static int fuse_mkdir(struct inode *dir, struct dentry *entry, int mode)
317 {
318 struct fuse_mkdir_in inarg;
319 struct fuse_conn *fc = get_fuse_conn(dir);
320 struct fuse_req *req = fuse_get_request(fc);
321 if (!req)
322 return -EINTR;
323
324 memset(&inarg, 0, sizeof(inarg));
325 inarg.mode = mode;
326 req->in.h.opcode = FUSE_MKDIR;
327 req->in.numargs = 2;
328 req->in.args[0].size = sizeof(inarg);
329 req->in.args[0].value = &inarg;
330 req->in.args[1].size = entry->d_name.len + 1;
331 req->in.args[1].value = entry->d_name.name;
332 return create_new_entry(fc, req, dir, entry, S_IFDIR);
333 }
334
335 static int fuse_symlink(struct inode *dir, struct dentry *entry,
336 const char *link)
337 {
338 struct fuse_conn *fc = get_fuse_conn(dir);
339 unsigned len = strlen(link) + 1;
340 struct fuse_req *req;
341
342 if (len > FUSE_SYMLINK_MAX)
343 return -ENAMETOOLONG;
344
345 req = fuse_get_request(fc);
346 if (!req)
347 return -EINTR;
348
349 req->in.h.opcode = FUSE_SYMLINK;
350 req->in.numargs = 2;
351 req->in.args[0].size = entry->d_name.len + 1;
352 req->in.args[0].value = entry->d_name.name;
353 req->in.args[1].size = len;
354 req->in.args[1].value = link;
355 return create_new_entry(fc, req, dir, entry, S_IFLNK);
356 }
357
358 static int fuse_unlink(struct inode *dir, struct dentry *entry)
359 {
360 int err;
361 struct fuse_conn *fc = get_fuse_conn(dir);
362 struct fuse_req *req = fuse_get_request(fc);
363 if (!req)
364 return -EINTR;
365
366 req->in.h.opcode = FUSE_UNLINK;
367 req->in.h.nodeid = get_node_id(dir);
368 req->inode = dir;
369 req->in.numargs = 1;
370 req->in.args[0].size = entry->d_name.len + 1;
371 req->in.args[0].value = entry->d_name.name;
372 request_send(fc, req);
373 err = req->out.h.error;
374 fuse_put_request(fc, req);
375 if (!err) {
376 struct inode *inode = entry->d_inode;
377
378 /* Set nlink to zero so the inode can be cleared, if
379 the inode does have more links this will be
380 discovered at the next lookup/getattr */
381 inode->i_nlink = 0;
382 fuse_invalidate_attr(inode);
383 fuse_invalidate_attr(dir);
384 } else if (err == -EINTR)
385 fuse_invalidate_entry(entry);
386 return err;
387 }
388
389 static int fuse_rmdir(struct inode *dir, struct dentry *entry)
390 {
391 int err;
392 struct fuse_conn *fc = get_fuse_conn(dir);
393 struct fuse_req *req = fuse_get_request(fc);
394 if (!req)
395 return -EINTR;
396
397 req->in.h.opcode = FUSE_RMDIR;
398 req->in.h.nodeid = get_node_id(dir);
399 req->inode = dir;
400 req->in.numargs = 1;
401 req->in.args[0].size = entry->d_name.len + 1;
402 req->in.args[0].value = entry->d_name.name;
403 request_send(fc, req);
404 err = req->out.h.error;
405 fuse_put_request(fc, req);
406 if (!err) {
407 entry->d_inode->i_nlink = 0;
408 fuse_invalidate_attr(dir);
409 } else if (err == -EINTR)
410 fuse_invalidate_entry(entry);
411 return err;
412 }
413
414 static int fuse_rename(struct inode *olddir, struct dentry *oldent,
415 struct inode *newdir, struct dentry *newent)
416 {
417 int err;
418 struct fuse_rename_in inarg;
419 struct fuse_conn *fc = get_fuse_conn(olddir);
420 struct fuse_req *req = fuse_get_request(fc);
421 if (!req)
422 return -EINTR;
423
424 memset(&inarg, 0, sizeof(inarg));
425 inarg.newdir = get_node_id(newdir);
426 req->in.h.opcode = FUSE_RENAME;
427 req->in.h.nodeid = get_node_id(olddir);
428 req->inode = olddir;
429 req->inode2 = newdir;
430 req->in.numargs = 3;
431 req->in.args[0].size = sizeof(inarg);
432 req->in.args[0].value = &inarg;
433 req->in.args[1].size = oldent->d_name.len + 1;
434 req->in.args[1].value = oldent->d_name.name;
435 req->in.args[2].size = newent->d_name.len + 1;
436 req->in.args[2].value = newent->d_name.name;
437 request_send(fc, req);
438 err = req->out.h.error;
439 fuse_put_request(fc, req);
440 if (!err) {
441 fuse_invalidate_attr(olddir);
442 if (olddir != newdir)
443 fuse_invalidate_attr(newdir);
444 } else if (err == -EINTR) {
445 /* If request was interrupted, DEITY only knows if the
446 rename actually took place. If the invalidation
447 fails (e.g. some process has CWD under the renamed
448 directory), then there can be inconsistency between
449 the dcache and the real filesystem. Tough luck. */
450 fuse_invalidate_entry(oldent);
451 if (newent->d_inode)
452 fuse_invalidate_entry(newent);
453 }
454
455 return err;
456 }
457
458 static int fuse_link(struct dentry *entry, struct inode *newdir,
459 struct dentry *newent)
460 {
461 int err;
462 struct fuse_link_in inarg;
463 struct inode *inode = entry->d_inode;
464 struct fuse_conn *fc = get_fuse_conn(inode);
465 struct fuse_req *req = fuse_get_request(fc);
466 if (!req)
467 return -EINTR;
468
469 memset(&inarg, 0, sizeof(inarg));
470 inarg.oldnodeid = get_node_id(inode);
471 req->in.h.opcode = FUSE_LINK;
472 req->inode2 = inode;
473 req->in.numargs = 2;
474 req->in.args[0].size = sizeof(inarg);
475 req->in.args[0].value = &inarg;
476 req->in.args[1].size = newent->d_name.len + 1;
477 req->in.args[1].value = newent->d_name.name;
478 err = create_new_entry(fc, req, newdir, newent, inode->i_mode);
479 /* Contrary to "normal" filesystems it can happen that link
480 makes two "logical" inodes point to the same "physical"
481 inode. We invalidate the attributes of the old one, so it
482 will reflect changes in the backing inode (link count,
483 etc.)
484 */
485 if (!err || err == -EINTR)
486 fuse_invalidate_attr(inode);
487 return err;
488 }
489
490 int fuse_do_getattr(struct inode *inode)
491 {
492 int err;
493 struct fuse_attr_out arg;
494 struct fuse_conn *fc = get_fuse_conn(inode);
495 struct fuse_req *req = fuse_get_request(fc);
496 if (!req)
497 return -EINTR;
498
499 req->in.h.opcode = FUSE_GETATTR;
500 req->in.h.nodeid = get_node_id(inode);
501 req->inode = inode;
502 req->out.numargs = 1;
503 req->out.args[0].size = sizeof(arg);
504 req->out.args[0].value = &arg;
505 request_send(fc, req);
506 err = req->out.h.error;
507 fuse_put_request(fc, req);
508 if (!err) {
509 if ((inode->i_mode ^ arg.attr.mode) & S_IFMT) {
510 make_bad_inode(inode);
511 err = -EIO;
512 } else {
513 struct fuse_inode *fi = get_fuse_inode(inode);
514 fuse_change_attributes(inode, &arg.attr);
515 fi->i_time = time_to_jiffies(arg.attr_valid,
516 arg.attr_valid_nsec);
517 }
518 }
519 return err;
520 }
521
522 /*
523 * Calling into a user-controlled filesystem gives the filesystem
524 * daemon ptrace-like capabilities over the requester process. This
525 * means, that the filesystem daemon is able to record the exact
526 * filesystem operations performed, and can also control the behavior
527 * of the requester process in otherwise impossible ways. For example
528 * it can delay the operation for arbitrary length of time allowing
529 * DoS against the requester.
530 *
531 * For this reason only those processes can call into the filesystem,
532 * for which the owner of the mount has ptrace privilege. This
533 * excludes processes started by other users, suid or sgid processes.
534 */
535 static int fuse_allow_task(struct fuse_conn *fc, struct task_struct *task)
536 {
537 if (fc->flags & FUSE_ALLOW_OTHER)
538 return 1;
539
540 if (task->euid == fc->user_id &&
541 task->suid == fc->user_id &&
542 task->uid == fc->user_id &&
543 task->egid == fc->group_id &&
544 task->sgid == fc->group_id &&
545 task->gid == fc->group_id)
546 return 1;
547
548 return 0;
549 }
550
551 static int fuse_revalidate(struct dentry *entry)
552 {
553 struct inode *inode = entry->d_inode;
554 struct fuse_inode *fi = get_fuse_inode(inode);
555 struct fuse_conn *fc = get_fuse_conn(inode);
556
557 if (!fuse_allow_task(fc, current))
558 return -EACCES;
559 if (get_node_id(inode) != FUSE_ROOT_ID &&
560 time_before_eq(jiffies, fi->i_time))
561 return 0;
562
563 return fuse_do_getattr(inode);
564 }
565
566 static int fuse_access(struct inode *inode, int mask)
567 {
568 struct fuse_conn *fc = get_fuse_conn(inode);
569 struct fuse_req *req;
570 struct fuse_access_in inarg;
571 int err;
572
573 if (fc->no_access)
574 return 0;
575
576 req = fuse_get_request(fc);
577 if (!req)
578 return -EINTR;
579
580 memset(&inarg, 0, sizeof(inarg));
581 inarg.mask = mask;
582 req->in.h.opcode = FUSE_ACCESS;
583 req->in.h.nodeid = get_node_id(inode);
584 req->inode = inode;
585 req->in.numargs = 1;
586 req->in.args[0].size = sizeof(inarg);
587 req->in.args[0].value = &inarg;
588 request_send(fc, req);
589 err = req->out.h.error;
590 fuse_put_request(fc, req);
591 if (err == -ENOSYS) {
592 fc->no_access = 1;
593 err = 0;
594 }
595 return err;
596 }
597
598 static int fuse_permission(struct inode *inode, int mask, struct nameidata *nd)
599 {
600 struct fuse_conn *fc = get_fuse_conn(inode);
601
602 if (!fuse_allow_task(fc, current))
603 return -EACCES;
604 else if (fc->flags & FUSE_DEFAULT_PERMISSIONS) {
605 int err = generic_permission(inode, mask, NULL);
606
607 /* If permission is denied, try to refresh file
608 attributes. This is also needed, because the root
609 node will at first have no permissions */
610 if (err == -EACCES) {
611 err = fuse_do_getattr(inode);
612 if (!err)
613 err = generic_permission(inode, mask, NULL);
614 }
615
616 /* FIXME: Need some mechanism to revoke permissions:
617 currently if the filesystem suddenly changes the
618 file mode, we will not be informed about it, and
619 continue to allow access to the file/directory.
620
621 This is actually not so grave, since the user can
622 simply keep access to the file/directory anyway by
623 keeping it open... */
624
625 return err;
626 } else {
627 int mode = inode->i_mode;
628 if ((mask & MAY_EXEC) && !S_ISDIR(mode) && !(mode & S_IXUGO))
629 return -EACCES;
630
631 if (nd && (nd->flags & LOOKUP_ACCESS))
632 return fuse_access(inode, mask);
633 return 0;
634 }
635 }
636
637 static int parse_dirfile(char *buf, size_t nbytes, struct file *file,
638 void *dstbuf, filldir_t filldir)
639 {
640 while (nbytes >= FUSE_NAME_OFFSET) {
641 struct fuse_dirent *dirent = (struct fuse_dirent *) buf;
642 size_t reclen = FUSE_DIRENT_SIZE(dirent);
643 int over;
644 if (!dirent->namelen || dirent->namelen > FUSE_NAME_MAX)
645 return -EIO;
646 if (reclen > nbytes)
647 break;
648
649 over = filldir(dstbuf, dirent->name, dirent->namelen,
650 file->f_pos, dirent->ino, dirent->type);
651 if (over)
652 break;
653
654 buf += reclen;
655 nbytes -= reclen;
656 file->f_pos = dirent->off;
657 }
658
659 return 0;
660 }
661
662 static inline size_t fuse_send_readdir(struct fuse_req *req, struct file *file,
663 struct inode *inode, loff_t pos,
664 size_t count)
665 {
666 return fuse_send_read_common(req, file, inode, pos, count, 1);
667 }
668
669 static int fuse_readdir(struct file *file, void *dstbuf, filldir_t filldir)
670 {
671 int err;
672 size_t nbytes;
673 struct page *page;
674 struct inode *inode = file->f_dentry->d_inode;
675 struct fuse_conn *fc = get_fuse_conn(inode);
676 struct fuse_req *req = fuse_get_request(fc);
677 if (!req)
678 return -EINTR;
679
680 page = alloc_page(GFP_KERNEL);
681 if (!page) {
682 fuse_put_request(fc, req);
683 return -ENOMEM;
684 }
685 req->num_pages = 1;
686 req->pages[0] = page;
687 nbytes = fuse_send_readdir(req, file, inode, file->f_pos, PAGE_SIZE);
688 err = req->out.h.error;
689 fuse_put_request(fc, req);
690 if (!err)
691 err = parse_dirfile(page_address(page), nbytes, file, dstbuf,
692 filldir);
693
694 __free_page(page);
695 fuse_invalidate_attr(inode); /* atime changed */
696 return err;
697 }
698
699 static char *read_link(struct dentry *dentry)
700 {
701 struct inode *inode = dentry->d_inode;
702 struct fuse_conn *fc = get_fuse_conn(inode);
703 struct fuse_req *req = fuse_get_request(fc);
704 char *link;
705
706 if (!req)
707 return ERR_PTR(-EINTR);
708
709 link = (char *) __get_free_page(GFP_KERNEL);
710 if (!link) {
711 link = ERR_PTR(-ENOMEM);
712 goto out;
713 }
714 req->in.h.opcode = FUSE_READLINK;
715 req->in.h.nodeid = get_node_id(inode);
716 req->inode = inode;
717 req->out.argvar = 1;
718 req->out.numargs = 1;
719 req->out.args[0].size = PAGE_SIZE - 1;
720 req->out.args[0].value = link;
721 request_send(fc, req);
722 if (req->out.h.error) {
723 free_page((unsigned long) link);
724 link = ERR_PTR(req->out.h.error);
725 } else
726 link[req->out.args[0].size] = '\0';
727 out:
728 fuse_put_request(fc, req);
729 fuse_invalidate_attr(inode); /* atime changed */
730 return link;
731 }
732
733 static void free_link(char *link)
734 {
735 if (!IS_ERR(link))
736 free_page((unsigned long) link);
737 }
738
739 static void *fuse_follow_link(struct dentry *dentry, struct nameidata *nd)
740 {
741 nd_set_link(nd, read_link(dentry));
742 return NULL;
743 }
744
745 static void fuse_put_link(struct dentry *dentry, struct nameidata *nd, void *c)
746 {
747 free_link(nd_get_link(nd));
748 }
749
750 static int fuse_dir_open(struct inode *inode, struct file *file)
751 {
752 return fuse_open_common(inode, file, 1);
753 }
754
755 static int fuse_dir_release(struct inode *inode, struct file *file)
756 {
757 return fuse_release_common(inode, file, 1);
758 }
759
760 static int fuse_dir_fsync(struct file *file, struct dentry *de, int datasync)
761 {
762 /* nfsd can call this with no file */
763 return file ? fuse_fsync_common(file, de, datasync, 1) : 0;
764 }
765
766 static void iattr_to_fattr(struct iattr *iattr, struct fuse_setattr_in *arg)
767 {
768 unsigned ivalid = iattr->ia_valid;
769
770 if (ivalid & ATTR_MODE)
771 arg->valid |= FATTR_MODE, arg->mode = iattr->ia_mode;
772 if (ivalid & ATTR_UID)
773 arg->valid |= FATTR_UID, arg->uid = iattr->ia_uid;
774 if (ivalid & ATTR_GID)
775 arg->valid |= FATTR_GID, arg->gid = iattr->ia_gid;
776 if (ivalid & ATTR_SIZE)
777 arg->valid |= FATTR_SIZE, arg->size = iattr->ia_size;
778 /* You can only _set_ these together (they may change by themselves) */
779 if ((ivalid & (ATTR_ATIME | ATTR_MTIME)) == (ATTR_ATIME | ATTR_MTIME)) {
780 arg->valid |= FATTR_ATIME | FATTR_MTIME;
781 arg->atime = iattr->ia_atime.tv_sec;
782 arg->mtime = iattr->ia_mtime.tv_sec;
783 }
784 if (ivalid & ATTR_FILE) {
785 struct fuse_file *ff = iattr->ia_file->private_data;
786 arg->valid |= FATTR_FH;
787 arg->fh = ff->fh;
788 }
789 }
790
791 static int fuse_setattr(struct dentry *entry, struct iattr *attr)
792 {
793 struct inode *inode = entry->d_inode;
794 struct fuse_conn *fc = get_fuse_conn(inode);
795 struct fuse_inode *fi = get_fuse_inode(inode);
796 struct fuse_req *req;
797 struct fuse_setattr_in inarg;
798 struct fuse_attr_out outarg;
799 int err;
800 int is_truncate = 0;
801
802 if (fc->flags & FUSE_DEFAULT_PERMISSIONS) {
803 err = inode_change_ok(inode, attr);
804 if (err)
805 return err;
806 }
807
808 if (attr->ia_valid & ATTR_SIZE) {
809 unsigned long limit;
810 is_truncate = 1;
811 limit = current->signal->rlim[RLIMIT_FSIZE].rlim_cur;
812 if (limit != RLIM_INFINITY && attr->ia_size > (loff_t) limit) {
813 send_sig(SIGXFSZ, current, 0);
814 return -EFBIG;
815 }
816 }
817
818 req = fuse_get_request(fc);
819 if (!req)
820 return -EINTR;
821
822 memset(&inarg, 0, sizeof(inarg));
823 iattr_to_fattr(attr, &inarg);
824 req->in.h.opcode = FUSE_SETATTR;
825 req->in.h.nodeid = get_node_id(inode);
826 req->inode = inode;
827 req->in.numargs = 1;
828 req->in.args[0].size = sizeof(inarg);
829 req->in.args[0].value = &inarg;
830 req->out.numargs = 1;
831 req->out.args[0].size = sizeof(outarg);
832 req->out.args[0].value = &outarg;
833 request_send(fc, req);
834 err = req->out.h.error;
835 fuse_put_request(fc, req);
836 if (!err) {
837 if ((inode->i_mode ^ outarg.attr.mode) & S_IFMT) {
838 make_bad_inode(inode);
839 err = -EIO;
840 } else {
841 if (is_truncate) {
842 loff_t origsize = i_size_read(inode);
843 i_size_write(inode, outarg.attr.size);
844 if (origsize > outarg.attr.size)
845 vmtruncate(inode, outarg.attr.size);
846 }
847 fuse_change_attributes(inode, &outarg.attr);
848 fi->i_time = time_to_jiffies(outarg.attr_valid,
849 outarg.attr_valid_nsec);
850 }
851 } else if (err == -EINTR)
852 fuse_invalidate_attr(inode);
853
854 return err;
855 }
856
857 static int fuse_getattr(struct vfsmount *mnt, struct dentry *entry,
858 struct kstat *stat)
859 {
860 struct inode *inode = entry->d_inode;
861 int err = fuse_revalidate(entry);
862 if (!err)
863 generic_fillattr(inode, stat);
864
865 return err;
866 }
867
868 static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry,
869 struct nameidata *nd)
870 {
871 struct inode *inode;
872 int err;
873
874 err = fuse_lookup_iget(dir, entry, &inode);
875 if (err)
876 return ERR_PTR(err);
877 if (inode && S_ISDIR(inode->i_mode)) {
878 /* Don't allow creating an alias to a directory */
879 struct dentry *alias = d_find_alias(inode);
880 if (alias) {
881 dput(alias);
882 iput(inode);
883 return ERR_PTR(-EIO);
884 }
885 }
886 d_add(entry, inode);
887 return NULL;
888 }
889
890 static int fuse_setxattr(struct dentry *entry, const char *name,
891 const void *value, size_t size, int flags)
892 {
893 struct inode *inode = entry->d_inode;
894 struct fuse_conn *fc = get_fuse_conn(inode);
895 struct fuse_req *req;
896 struct fuse_setxattr_in inarg;
897 int err;
898
899 if (size > FUSE_XATTR_SIZE_MAX)
900 return -E2BIG;
901
902 if (fc->no_setxattr)
903 return -EOPNOTSUPP;
904
905 req = fuse_get_request(fc);
906 if (!req)
907 return -EINTR;
908
909 memset(&inarg, 0, sizeof(inarg));
910 inarg.size = size;
911 inarg.flags = flags;
912 req->in.h.opcode = FUSE_SETXATTR;
913 req->in.h.nodeid = get_node_id(inode);
914 req->inode = inode;
915 req->in.numargs = 3;
916 req->in.args[0].size = sizeof(inarg);
917 req->in.args[0].value = &inarg;
918 req->in.args[1].size = strlen(name) + 1;
919 req->in.args[1].value = name;
920 req->in.args[2].size = size;
921 req->in.args[2].value = value;
922 request_send(fc, req);
923 err = req->out.h.error;
924 fuse_put_request(fc, req);
925 if (err == -ENOSYS) {
926 fc->no_setxattr = 1;
927 err = -EOPNOTSUPP;
928 }
929 return err;
930 }
931
932 static ssize_t fuse_getxattr(struct dentry *entry, const char *name,
933 void *value, size_t size)
934 {
935 struct inode *inode = entry->d_inode;
936 struct fuse_conn *fc = get_fuse_conn(inode);
937 struct fuse_req *req;
938 struct fuse_getxattr_in inarg;
939 struct fuse_getxattr_out outarg;
940 ssize_t ret;
941
942 if (fc->no_getxattr)
943 return -EOPNOTSUPP;
944
945 req = fuse_get_request(fc);
946 if (!req)
947 return -EINTR;
948
949 memset(&inarg, 0, sizeof(inarg));
950 inarg.size = size;
951 req->in.h.opcode = FUSE_GETXATTR;
952 req->in.h.nodeid = get_node_id(inode);
953 req->inode = inode;
954 req->in.numargs = 2;
955 req->in.args[0].size = sizeof(inarg);
956 req->in.args[0].value = &inarg;
957 req->in.args[1].size = strlen(name) + 1;
958 req->in.args[1].value = name;
959 /* This is really two different operations rolled into one */
960 req->out.numargs = 1;
961 if (size) {
962 req->out.argvar = 1;
963 req->out.args[0].size = size;
964 req->out.args[0].value = value;
965 } else {
966 req->out.args[0].size = sizeof(outarg);
967 req->out.args[0].value = &outarg;
968 }
969 request_send(fc, req);
970 ret = req->out.h.error;
971 if (!ret)
972 ret = size ? req->out.args[0].size : outarg.size;
973 else {
974 if (ret == -ENOSYS) {
975 fc->no_getxattr = 1;
976 ret = -EOPNOTSUPP;
977 }
978 }
979 fuse_put_request(fc, req);
980 return ret;
981 }
982
983 static ssize_t fuse_listxattr(struct dentry *entry, char *list, size_t size)
984 {
985 struct inode *inode = entry->d_inode;
986 struct fuse_conn *fc = get_fuse_conn(inode);
987 struct fuse_req *req;
988 struct fuse_getxattr_in inarg;
989 struct fuse_getxattr_out outarg;
990 ssize_t ret;
991
992 if (fc->no_listxattr)
993 return -EOPNOTSUPP;
994
995 req = fuse_get_request(fc);
996 if (!req)
997 return -EINTR;
998
999 memset(&inarg, 0, sizeof(inarg));
1000 inarg.size = size;
1001 req->in.h.opcode = FUSE_LISTXATTR;
1002 req->in.h.nodeid = get_node_id(inode);
1003 req->inode = inode;
1004 req->in.numargs = 1;
1005 req->in.args[0].size = sizeof(inarg);
1006 req->in.args[0].value = &inarg;
1007 /* This is really two different operations rolled into one */
1008 req->out.numargs = 1;
1009 if (size) {
1010 req->out.argvar = 1;
1011 req->out.args[0].size = size;
1012 req->out.args[0].value = list;
1013 } else {
1014 req->out.args[0].size = sizeof(outarg);
1015 req->out.args[0].value = &outarg;
1016 }
1017 request_send(fc, req);
1018 ret = req->out.h.error;
1019 if (!ret)
1020 ret = size ? req->out.args[0].size : outarg.size;
1021 else {
1022 if (ret == -ENOSYS) {
1023 fc->no_listxattr = 1;
1024 ret = -EOPNOTSUPP;
1025 }
1026 }
1027 fuse_put_request(fc, req);
1028 return ret;
1029 }
1030
1031 static int fuse_removexattr(struct dentry *entry, const char *name)
1032 {
1033 struct inode *inode = entry->d_inode;
1034 struct fuse_conn *fc = get_fuse_conn(inode);
1035 struct fuse_req *req;
1036 int err;
1037
1038 if (fc->no_removexattr)
1039 return -EOPNOTSUPP;
1040
1041 req = fuse_get_request(fc);
1042 if (!req)
1043 return -EINTR;
1044
1045 req->in.h.opcode = FUSE_REMOVEXATTR;
1046 req->in.h.nodeid = get_node_id(inode);
1047 req->inode = inode;
1048 req->in.numargs = 1;
1049 req->in.args[0].size = strlen(name) + 1;
1050 req->in.args[0].value = name;
1051 request_send(fc, req);
1052 err = req->out.h.error;
1053 fuse_put_request(fc, req);
1054 if (err == -ENOSYS) {
1055 fc->no_removexattr = 1;
1056 err = -EOPNOTSUPP;
1057 }
1058 return err;
1059 }
1060
1061 static struct inode_operations fuse_dir_inode_operations = {
1062 .lookup = fuse_lookup,
1063 .mkdir = fuse_mkdir,
1064 .symlink = fuse_symlink,
1065 .unlink = fuse_unlink,
1066 .rmdir = fuse_rmdir,
1067 .rename = fuse_rename,
1068 .link = fuse_link,
1069 .setattr = fuse_setattr,
1070 .create = fuse_create,
1071 .mknod = fuse_mknod,
1072 .permission = fuse_permission,
1073 .getattr = fuse_getattr,
1074 .setxattr = fuse_setxattr,
1075 .getxattr = fuse_getxattr,
1076 .listxattr = fuse_listxattr,
1077 .removexattr = fuse_removexattr,
1078 };
1079
1080 static struct file_operations fuse_dir_operations = {
1081 .llseek = generic_file_llseek,
1082 .read = generic_read_dir,
1083 .readdir = fuse_readdir,
1084 .open = fuse_dir_open,
1085 .release = fuse_dir_release,
1086 .fsync = fuse_dir_fsync,
1087 };
1088
1089 static struct inode_operations fuse_common_inode_operations = {
1090 .setattr = fuse_setattr,
1091 .permission = fuse_permission,
1092 .getattr = fuse_getattr,
1093 .setxattr = fuse_setxattr,
1094 .getxattr = fuse_getxattr,
1095 .listxattr = fuse_listxattr,
1096 .removexattr = fuse_removexattr,
1097 };
1098
1099 static struct inode_operations fuse_symlink_inode_operations = {
1100 .setattr = fuse_setattr,
1101 .follow_link = fuse_follow_link,
1102 .put_link = fuse_put_link,
1103 .readlink = generic_readlink,
1104 .getattr = fuse_getattr,
1105 .setxattr = fuse_setxattr,
1106 .getxattr = fuse_getxattr,
1107 .listxattr = fuse_listxattr,
1108 .removexattr = fuse_removexattr,
1109 };
1110
1111 void fuse_init_common(struct inode *inode)
1112 {
1113 inode->i_op = &fuse_common_inode_operations;
1114 }
1115
1116 void fuse_init_dir(struct inode *inode)
1117 {
1118 inode->i_op = &fuse_dir_inode_operations;
1119 inode->i_fop = &fuse_dir_operations;
1120 }
1121
1122 void fuse_init_symlink(struct inode *inode)
1123 {
1124 inode->i_op = &fuse_symlink_inode_operations;
1125 }
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