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HID: hiddev: Fix slab-out-of-bounds write in hiddev_ioctl_usage()
[linux/fpc-iii.git] / fs / fuse / inode.c
blob4b2eb65be0d400cb2ea1340a7cfcf76d72a81ba6
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/slab.h>
13 #include <linux/file.h>
14 #include <linux/seq_file.h>
15 #include <linux/init.h>
16 #include <linux/module.h>
17 #include <linux/moduleparam.h>
18 #include <linux/parser.h>
19 #include <linux/statfs.h>
20 #include <linux/random.h>
21 #include <linux/sched.h>
22 #include <linux/exportfs.h>
23
24 MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>");
25 MODULE_DESCRIPTION("Filesystem in Userspace");
26 MODULE_LICENSE("GPL");
27
28 static struct kmem_cache *fuse_inode_cachep;
29 struct list_head fuse_conn_list;
30 DEFINE_MUTEX(fuse_mutex);
31
32 static int set_global_limit(const char *val, struct kernel_param *kp);
33
34 unsigned max_user_bgreq;
35 module_param_call(max_user_bgreq, set_global_limit, param_get_uint,
36 &max_user_bgreq, 0644);
37 __MODULE_PARM_TYPE(max_user_bgreq, "uint");
38 MODULE_PARM_DESC(max_user_bgreq,
39 "Global limit for the maximum number of backgrounded requests an "
40 "unprivileged user can set");
41
42 unsigned max_user_congthresh;
43 module_param_call(max_user_congthresh, set_global_limit, param_get_uint,
44 &max_user_congthresh, 0644);
45 __MODULE_PARM_TYPE(max_user_congthresh, "uint");
46 MODULE_PARM_DESC(max_user_congthresh,
47 "Global limit for the maximum congestion threshold an "
48 "unprivileged user can set");
49
50 #define FUSE_SUPER_MAGIC 0x65735546
51
52 #define FUSE_DEFAULT_BLKSIZE 512
53
54 /** Maximum number of outstanding background requests */
55 #define FUSE_DEFAULT_MAX_BACKGROUND 12
56
57 /** Congestion starts at 75% of maximum */
58 #define FUSE_DEFAULT_CONGESTION_THRESHOLD (FUSE_DEFAULT_MAX_BACKGROUND * 3 / 4)
59
60 struct fuse_mount_data {
61 int fd;
62 unsigned rootmode;
63 kuid_t user_id;
64 kgid_t group_id;
65 unsigned fd_present:1;
66 unsigned rootmode_present:1;
67 unsigned user_id_present:1;
68 unsigned group_id_present:1;
69 unsigned flags;
70 unsigned max_read;
71 unsigned blksize;
72 };
73
74 struct fuse_forget_link *fuse_alloc_forget(void)
75 {
76 return kzalloc(sizeof(struct fuse_forget_link), GFP_KERNEL);
77 }
78
79 static struct inode *fuse_alloc_inode(struct super_block *sb)
80 {
81 struct inode *inode;
82 struct fuse_inode *fi;
83
84 inode = kmem_cache_alloc(fuse_inode_cachep, GFP_KERNEL);
85 if (!inode)
86 return NULL;
87
88 fi = get_fuse_inode(inode);
89 fi->i_time = 0;
90 fi->nodeid = 0;
91 fi->nlookup = 0;
92 fi->attr_version = 0;
93 fi->writectr = 0;
94 fi->orig_ino = 0;
95 fi->state = 0;
96 INIT_LIST_HEAD(&fi->write_files);
97 INIT_LIST_HEAD(&fi->queued_writes);
98 INIT_LIST_HEAD(&fi->writepages);
99 init_waitqueue_head(&fi->page_waitq);
100 fi->forget = fuse_alloc_forget();
101 if (!fi->forget) {
102 kmem_cache_free(fuse_inode_cachep, inode);
103 return NULL;
104 }
105
106 return inode;
107 }
108
109 static void fuse_i_callback(struct rcu_head *head)
110 {
111 struct inode *inode = container_of(head, struct inode, i_rcu);
112 kmem_cache_free(fuse_inode_cachep, inode);
113 }
114
115 static void fuse_destroy_inode(struct inode *inode)
116 {
117 struct fuse_inode *fi = get_fuse_inode(inode);
118 BUG_ON(!list_empty(&fi->write_files));
119 BUG_ON(!list_empty(&fi->queued_writes));
120 kfree(fi->forget);
121 call_rcu(&inode->i_rcu, fuse_i_callback);
122 }
123
124 static void fuse_evict_inode(struct inode *inode)
125 {
126 truncate_inode_pages_final(&inode->i_data);
127 clear_inode(inode);
128 if (inode->i_sb->s_flags & MS_ACTIVE) {
129 struct fuse_conn *fc = get_fuse_conn(inode);
130 struct fuse_inode *fi = get_fuse_inode(inode);
131 fuse_queue_forget(fc, fi->forget, fi->nodeid, fi->nlookup);
132 fi->forget = NULL;
133 }
134 }
135
136 static int fuse_remount_fs(struct super_block *sb, int *flags, char *data)
137 {
138 sync_filesystem(sb);
139 if (*flags & MS_MANDLOCK)
140 return -EINVAL;
141
142 return 0;
143 }
144
145 /*
146 * ino_t is 32-bits on 32-bit arch. We have to squash the 64-bit value down
147 * so that it will fit.
148 */
149 static ino_t fuse_squash_ino(u64 ino64)
150 {
151 ino_t ino = (ino_t) ino64;
152 if (sizeof(ino_t) < sizeof(u64))
153 ino ^= ino64 >> (sizeof(u64) - sizeof(ino_t)) * 8;
154 return ino;
155 }
156
157 void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
158 u64 attr_valid)
159 {
160 struct fuse_conn *fc = get_fuse_conn(inode);
161 struct fuse_inode *fi = get_fuse_inode(inode);
162
163 fi->attr_version = ++fc->attr_version;
164 fi->i_time = attr_valid;
165
166 inode->i_ino = fuse_squash_ino(attr->ino);
167 inode->i_mode = (inode->i_mode & S_IFMT) | (attr->mode & 07777);
168 set_nlink(inode, attr->nlink);
169 inode->i_uid = make_kuid(&init_user_ns, attr->uid);
170 inode->i_gid = make_kgid(&init_user_ns, attr->gid);
171 inode->i_blocks = attr->blocks;
172 inode->i_atime.tv_sec = attr->atime;
173 inode->i_atime.tv_nsec = attr->atimensec;
174 /* mtime from server may be stale due to local buffered write */
175 if (!fc->writeback_cache || !S_ISREG(inode->i_mode)) {
176 inode->i_mtime.tv_sec = attr->mtime;
177 inode->i_mtime.tv_nsec = attr->mtimensec;
178 inode->i_ctime.tv_sec = attr->ctime;
179 inode->i_ctime.tv_nsec = attr->ctimensec;
180 }
181
182 if (attr->blksize != 0)
183 inode->i_blkbits = ilog2(attr->blksize);
184 else
185 inode->i_blkbits = inode->i_sb->s_blocksize_bits;
186
187 /*
188 * Don't set the sticky bit in i_mode, unless we want the VFS
189 * to check permissions. This prevents failures due to the
190 * check in may_delete().
191 */
192 fi->orig_i_mode = inode->i_mode;
193 if (!(fc->flags & FUSE_DEFAULT_PERMISSIONS))
194 inode->i_mode &= ~S_ISVTX;
195
196 fi->orig_ino = attr->ino;
197 }
198
199 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
200 u64 attr_valid, u64 attr_version)
201 {
202 struct fuse_conn *fc = get_fuse_conn(inode);
203 struct fuse_inode *fi = get_fuse_inode(inode);
204 bool is_wb = fc->writeback_cache;
205 loff_t oldsize;
206 struct timespec old_mtime;
207
208 spin_lock(&fc->lock);
209 if ((attr_version != 0 && fi->attr_version > attr_version) ||
210 test_bit(FUSE_I_SIZE_UNSTABLE, &fi->state)) {
211 spin_unlock(&fc->lock);
212 return;
213 }
214
215 old_mtime = inode->i_mtime;
216 fuse_change_attributes_common(inode, attr, attr_valid);
217
218 oldsize = inode->i_size;
219 /*
220 * In case of writeback_cache enabled, the cached writes beyond EOF
221 * extend local i_size without keeping userspace server in sync. So,
222 * attr->size coming from server can be stale. We cannot trust it.
223 */
224 if (!is_wb || !S_ISREG(inode->i_mode))
225 i_size_write(inode, attr->size);
226 spin_unlock(&fc->lock);
227
228 if (!is_wb && S_ISREG(inode->i_mode)) {
229 bool inval = false;
230
231 if (oldsize != attr->size) {
232 truncate_pagecache(inode, attr->size);
233 inval = true;
234 } else if (fc->auto_inval_data) {
235 struct timespec new_mtime = {
236 .tv_sec = attr->mtime,
237 .tv_nsec = attr->mtimensec,
238 };
239
240 /*
241 * Auto inval mode also checks and invalidates if mtime
242 * has changed.
243 */
244 if (!timespec_equal(&old_mtime, &new_mtime))
245 inval = true;
246 }
247
248 if (inval)
249 invalidate_inode_pages2(inode->i_mapping);
250 }
251 }
252
253 static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
254 {
255 inode->i_mode = attr->mode & S_IFMT;
256 inode->i_size = attr->size;
257 inode->i_mtime.tv_sec = attr->mtime;
258 inode->i_mtime.tv_nsec = attr->mtimensec;
259 inode->i_ctime.tv_sec = attr->ctime;
260 inode->i_ctime.tv_nsec = attr->ctimensec;
261 if (S_ISREG(inode->i_mode)) {
262 fuse_init_common(inode);
263 fuse_init_file_inode(inode);
264 } else if (S_ISDIR(inode->i_mode))
265 fuse_init_dir(inode);
266 else if (S_ISLNK(inode->i_mode))
267 fuse_init_symlink(inode);
268 else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
269 S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
270 fuse_init_common(inode);
271 init_special_inode(inode, inode->i_mode,
272 new_decode_dev(attr->rdev));
273 } else
274 BUG();
275 }
276
277 int fuse_inode_eq(struct inode *inode, void *_nodeidp)
278 {
279 u64 nodeid = *(u64 *) _nodeidp;
280 if (get_node_id(inode) == nodeid)
281 return 1;
282 else
283 return 0;
284 }
285
286 static int fuse_inode_set(struct inode *inode, void *_nodeidp)
287 {
288 u64 nodeid = *(u64 *) _nodeidp;
289 get_fuse_inode(inode)->nodeid = nodeid;
290 return 0;
291 }
292
293 struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
294 int generation, struct fuse_attr *attr,
295 u64 attr_valid, u64 attr_version)
296 {
297 struct inode *inode;
298 struct fuse_inode *fi;
299 struct fuse_conn *fc = get_fuse_conn_super(sb);
300
301 retry:
302 inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid);
303 if (!inode)
304 return NULL;
305
306 if ((inode->i_state & I_NEW)) {
307 inode->i_flags |= S_NOATIME;
308 if (!fc->writeback_cache || !S_ISREG(attr->mode))
309 inode->i_flags |= S_NOCMTIME;
310 inode->i_generation = generation;
311 fuse_init_inode(inode, attr);
312 unlock_new_inode(inode);
313 } else if ((inode->i_mode ^ attr->mode) & S_IFMT) {
314 /* Inode has changed type, any I/O on the old should fail */
315 make_bad_inode(inode);
316 iput(inode);
317 goto retry;
318 }
319
320 fi = get_fuse_inode(inode);
321 spin_lock(&fc->lock);
322 fi->nlookup++;
323 spin_unlock(&fc->lock);
324 fuse_change_attributes(inode, attr, attr_valid, attr_version);
325
326 return inode;
327 }
328
329 int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid,
330 loff_t offset, loff_t len)
331 {
332 struct inode *inode;
333 pgoff_t pg_start;
334 pgoff_t pg_end;
335
336 inode = ilookup5(sb, nodeid, fuse_inode_eq, &nodeid);
337 if (!inode)
338 return -ENOENT;
339
340 fuse_invalidate_attr(inode);
341 if (offset >= 0) {
342 pg_start = offset >> PAGE_CACHE_SHIFT;
343 if (len <= 0)
344 pg_end = -1;
345 else
346 pg_end = (offset + len - 1) >> PAGE_CACHE_SHIFT;
347 invalidate_inode_pages2_range(inode->i_mapping,
348 pg_start, pg_end);
349 }
350 iput(inode);
351 return 0;
352 }
353
354 static void fuse_umount_begin(struct super_block *sb)
355 {
356 fuse_abort_conn(get_fuse_conn_super(sb));
357 }
358
359 static void fuse_send_destroy(struct fuse_conn *fc)
360 {
361 struct fuse_req *req = fc->destroy_req;
362 if (req && fc->conn_init) {
363 fc->destroy_req = NULL;
364 req->in.h.opcode = FUSE_DESTROY;
365 __set_bit(FR_FORCE, &req->flags);
366 __clear_bit(FR_BACKGROUND, &req->flags);
367 fuse_request_send(fc, req);
368 fuse_put_request(fc, req);
369 }
370 }
371
372 static void fuse_bdi_destroy(struct fuse_conn *fc)
373 {
374 if (fc->bdi_initialized)
375 bdi_destroy(&fc->bdi);
376 }
377
378 static void fuse_put_super(struct super_block *sb)
379 {
380 struct fuse_conn *fc = get_fuse_conn_super(sb);
381
382 mutex_lock(&fuse_mutex);
383 list_del(&fc->entry);
384 fuse_ctl_remove_conn(fc);
385 mutex_unlock(&fuse_mutex);
386 fuse_bdi_destroy(fc);
387
388 fuse_conn_put(fc);
389 }
390
391 static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
392 {
393 stbuf->f_type = FUSE_SUPER_MAGIC;
394 stbuf->f_bsize = attr->bsize;
395 stbuf->f_frsize = attr->frsize;
396 stbuf->f_blocks = attr->blocks;
397 stbuf->f_bfree = attr->bfree;
398 stbuf->f_bavail = attr->bavail;
399 stbuf->f_files = attr->files;
400 stbuf->f_ffree = attr->ffree;
401 stbuf->f_namelen = attr->namelen;
402 /* fsid is left zero */
403 }
404
405 static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf)
406 {
407 struct super_block *sb = dentry->d_sb;
408 struct fuse_conn *fc = get_fuse_conn_super(sb);
409 FUSE_ARGS(args);
410 struct fuse_statfs_out outarg;
411 int err;
412
413 if (!fuse_allow_current_process(fc)) {
414 buf->f_type = FUSE_SUPER_MAGIC;
415 return 0;
416 }
417
418 memset(&outarg, 0, sizeof(outarg));
419 args.in.numargs = 0;
420 args.in.h.opcode = FUSE_STATFS;
421 args.in.h.nodeid = get_node_id(d_inode(dentry));
422 args.out.numargs = 1;
423 args.out.args[0].size = sizeof(outarg);
424 args.out.args[0].value = &outarg;
425 err = fuse_simple_request(fc, &args);
426 if (!err)
427 convert_fuse_statfs(buf, &outarg.st);
428 return err;
429 }
430
431 enum {
432 OPT_FD,
433 OPT_ROOTMODE,
434 OPT_USER_ID,
435 OPT_GROUP_ID,
436 OPT_DEFAULT_PERMISSIONS,
437 OPT_ALLOW_OTHER,
438 OPT_MAX_READ,
439 OPT_BLKSIZE,
440 OPT_ERR
441 };
442
443 static const match_table_t tokens = {
444 {OPT_FD, "fd=%u"},
445 {OPT_ROOTMODE, "rootmode=%o"},
446 {OPT_USER_ID, "user_id=%u"},
447 {OPT_GROUP_ID, "group_id=%u"},
448 {OPT_DEFAULT_PERMISSIONS, "default_permissions"},
449 {OPT_ALLOW_OTHER, "allow_other"},
450 {OPT_MAX_READ, "max_read=%u"},
451 {OPT_BLKSIZE, "blksize=%u"},
452 {OPT_ERR, NULL}
453 };
454
455 static int fuse_match_uint(substring_t *s, unsigned int *res)
456 {
457 int err = -ENOMEM;
458 char *buf = match_strdup(s);
459 if (buf) {
460 err = kstrtouint(buf, 10, res);
461 kfree(buf);
462 }
463 return err;
464 }
465
466 static int parse_fuse_opt(char *opt, struct fuse_mount_data *d, int is_bdev)
467 {
468 char *p;
469 memset(d, 0, sizeof(struct fuse_mount_data));
470 d->max_read = ~0;
471 d->blksize = FUSE_DEFAULT_BLKSIZE;
472
473 while ((p = strsep(&opt, ",")) != NULL) {
474 int token;
475 int value;
476 unsigned uv;
477 substring_t args[MAX_OPT_ARGS];
478 if (!*p)
479 continue;
480
481 token = match_token(p, tokens, args);
482 switch (token) {
483 case OPT_FD:
484 if (match_int(&args[0], &value))
485 return 0;
486 d->fd = value;
487 d->fd_present = 1;
488 break;
489
490 case OPT_ROOTMODE:
491 if (match_octal(&args[0], &value))
492 return 0;
493 if (!fuse_valid_type(value))
494 return 0;
495 d->rootmode = value;
496 d->rootmode_present = 1;
497 break;
498
499 case OPT_USER_ID:
500 if (fuse_match_uint(&args[0], &uv))
501 return 0;
502 d->user_id = make_kuid(current_user_ns(), uv);
503 if (!uid_valid(d->user_id))
504 return 0;
505 d->user_id_present = 1;
506 break;
507
508 case OPT_GROUP_ID:
509 if (fuse_match_uint(&args[0], &uv))
510 return 0;
511 d->group_id = make_kgid(current_user_ns(), uv);
512 if (!gid_valid(d->group_id))
513 return 0;
514 d->group_id_present = 1;
515 break;
516
517 case OPT_DEFAULT_PERMISSIONS:
518 d->flags |= FUSE_DEFAULT_PERMISSIONS;
519 break;
520
521 case OPT_ALLOW_OTHER:
522 d->flags |= FUSE_ALLOW_OTHER;
523 break;
524
525 case OPT_MAX_READ:
526 if (match_int(&args[0], &value))
527 return 0;
528 d->max_read = value;
529 break;
530
531 case OPT_BLKSIZE:
532 if (!is_bdev || match_int(&args[0], &value))
533 return 0;
534 d->blksize = value;
535 break;
536
537 default:
538 return 0;
539 }
540 }
541
542 if (!d->fd_present || !d->rootmode_present ||
543 !d->user_id_present || !d->group_id_present)
544 return 0;
545
546 return 1;
547 }
548
549 static int fuse_show_options(struct seq_file *m, struct dentry *root)
550 {
551 struct super_block *sb = root->d_sb;
552 struct fuse_conn *fc = get_fuse_conn_super(sb);
553
554 seq_printf(m, ",user_id=%u", from_kuid_munged(&init_user_ns, fc->user_id));
555 seq_printf(m, ",group_id=%u", from_kgid_munged(&init_user_ns, fc->group_id));
556 if (fc->flags & FUSE_DEFAULT_PERMISSIONS)
557 seq_puts(m, ",default_permissions");
558 if (fc->flags & FUSE_ALLOW_OTHER)
559 seq_puts(m, ",allow_other");
560 if (fc->max_read != ~0)
561 seq_printf(m, ",max_read=%u", fc->max_read);
562 if (sb->s_bdev && sb->s_blocksize != FUSE_DEFAULT_BLKSIZE)
563 seq_printf(m, ",blksize=%lu", sb->s_blocksize);
564 return 0;
565 }
566
567 static void fuse_iqueue_init(struct fuse_iqueue *fiq)
568 {
569 memset(fiq, 0, sizeof(struct fuse_iqueue));
570 init_waitqueue_head(&fiq->waitq);
571 INIT_LIST_HEAD(&fiq->pending);
572 INIT_LIST_HEAD(&fiq->interrupts);
573 fiq->forget_list_tail = &fiq->forget_list_head;
574 fiq->connected = 1;
575 }
576
577 static void fuse_pqueue_init(struct fuse_pqueue *fpq)
578 {
579 memset(fpq, 0, sizeof(struct fuse_pqueue));
580 spin_lock_init(&fpq->lock);
581 INIT_LIST_HEAD(&fpq->processing);
582 INIT_LIST_HEAD(&fpq->io);
583 fpq->connected = 1;
584 }
585
586 void fuse_conn_init(struct fuse_conn *fc)
587 {
588 memset(fc, 0, sizeof(*fc));
589 spin_lock_init(&fc->lock);
590 init_rwsem(&fc->killsb);
591 atomic_set(&fc->count, 1);
592 atomic_set(&fc->dev_count, 1);
593 init_waitqueue_head(&fc->blocked_waitq);
594 init_waitqueue_head(&fc->reserved_req_waitq);
595 fuse_iqueue_init(&fc->iq);
596 INIT_LIST_HEAD(&fc->bg_queue);
597 INIT_LIST_HEAD(&fc->entry);
598 INIT_LIST_HEAD(&fc->devices);
599 atomic_set(&fc->num_waiting, 0);
600 fc->max_background = FUSE_DEFAULT_MAX_BACKGROUND;
601 fc->congestion_threshold = FUSE_DEFAULT_CONGESTION_THRESHOLD;
602 fc->khctr = 0;
603 fc->polled_files = RB_ROOT;
604 fc->blocked = 0;
605 fc->initialized = 0;
606 fc->connected = 1;
607 fc->attr_version = 1;
608 get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key));
609 }
610 EXPORT_SYMBOL_GPL(fuse_conn_init);
611
612 void fuse_conn_put(struct fuse_conn *fc)
613 {
614 if (atomic_dec_and_test(&fc->count)) {
615 if (fc->destroy_req)
616 fuse_request_free(fc->destroy_req);
617 fc->release(fc);
618 }
619 }
620 EXPORT_SYMBOL_GPL(fuse_conn_put);
621
622 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc)
623 {
624 atomic_inc(&fc->count);
625 return fc;
626 }
627 EXPORT_SYMBOL_GPL(fuse_conn_get);
628
629 static struct inode *fuse_get_root_inode(struct super_block *sb, unsigned mode)
630 {
631 struct fuse_attr attr;
632 memset(&attr, 0, sizeof(attr));
633
634 attr.mode = mode;
635 attr.ino = FUSE_ROOT_ID;
636 attr.nlink = 1;
637 return fuse_iget(sb, 1, 0, &attr, 0, 0);
638 }
639
640 struct fuse_inode_handle {
641 u64 nodeid;
642 u32 generation;
643 };
644
645 static struct dentry *fuse_get_dentry(struct super_block *sb,
646 struct fuse_inode_handle *handle)
647 {
648 struct fuse_conn *fc = get_fuse_conn_super(sb);
649 struct inode *inode;
650 struct dentry *entry;
651 int err = -ESTALE;
652
653 if (handle->nodeid == 0)
654 goto out_err;
655
656 inode = ilookup5(sb, handle->nodeid, fuse_inode_eq, &handle->nodeid);
657 if (!inode) {
658 struct fuse_entry_out outarg;
659 struct qstr name;
660
661 if (!fc->export_support)
662 goto out_err;
663
664 name.len = 1;
665 name.name = ".";
666 err = fuse_lookup_name(sb, handle->nodeid, &name, &outarg,
667 &inode);
668 if (err && err != -ENOENT)
669 goto out_err;
670 if (err || !inode) {
671 err = -ESTALE;
672 goto out_err;
673 }
674 err = -EIO;
675 if (get_node_id(inode) != handle->nodeid)
676 goto out_iput;
677 }
678 err = -ESTALE;
679 if (inode->i_generation != handle->generation)
680 goto out_iput;
681
682 entry = d_obtain_alias(inode);
683 if (!IS_ERR(entry) && get_node_id(inode) != FUSE_ROOT_ID)
684 fuse_invalidate_entry_cache(entry);
685
686 return entry;
687
688 out_iput:
689 iput(inode);
690 out_err:
691 return ERR_PTR(err);
692 }
693
694 static int fuse_encode_fh(struct inode *inode, u32 *fh, int *max_len,
695 struct inode *parent)
696 {
697 int len = parent ? 6 : 3;
698 u64 nodeid;
699 u32 generation;
700
701 if (*max_len < len) {
702 *max_len = len;
703 return FILEID_INVALID;
704 }
705
706 nodeid = get_fuse_inode(inode)->nodeid;
707 generation = inode->i_generation;
708
709 fh[0] = (u32)(nodeid >> 32);
710 fh[1] = (u32)(nodeid & 0xffffffff);
711 fh[2] = generation;
712
713 if (parent) {
714 nodeid = get_fuse_inode(parent)->nodeid;
715 generation = parent->i_generation;
716
717 fh[3] = (u32)(nodeid >> 32);
718 fh[4] = (u32)(nodeid & 0xffffffff);
719 fh[5] = generation;
720 }
721
722 *max_len = len;
723 return parent ? 0x82 : 0x81;
724 }
725
726 static struct dentry *fuse_fh_to_dentry(struct super_block *sb,
727 struct fid *fid, int fh_len, int fh_type)
728 {
729 struct fuse_inode_handle handle;
730
731 if ((fh_type != 0x81 && fh_type != 0x82) || fh_len < 3)
732 return NULL;
733
734 handle.nodeid = (u64) fid->raw[0] << 32;
735 handle.nodeid |= (u64) fid->raw[1];
736 handle.generation = fid->raw[2];
737 return fuse_get_dentry(sb, &handle);
738 }
739
740 static struct dentry *fuse_fh_to_parent(struct super_block *sb,
741 struct fid *fid, int fh_len, int fh_type)
742 {
743 struct fuse_inode_handle parent;
744
745 if (fh_type != 0x82 || fh_len < 6)
746 return NULL;
747
748 parent.nodeid = (u64) fid->raw[3] << 32;
749 parent.nodeid |= (u64) fid->raw[4];
750 parent.generation = fid->raw[5];
751 return fuse_get_dentry(sb, &parent);
752 }
753
754 static struct dentry *fuse_get_parent(struct dentry *child)
755 {
756 struct inode *child_inode = d_inode(child);
757 struct fuse_conn *fc = get_fuse_conn(child_inode);
758 struct inode *inode;
759 struct dentry *parent;
760 struct fuse_entry_out outarg;
761 struct qstr name;
762 int err;
763
764 if (!fc->export_support)
765 return ERR_PTR(-ESTALE);
766
767 name.len = 2;
768 name.name = "..";
769 err = fuse_lookup_name(child_inode->i_sb, get_node_id(child_inode),
770 &name, &outarg, &inode);
771 if (err) {
772 if (err == -ENOENT)
773 return ERR_PTR(-ESTALE);
774 return ERR_PTR(err);
775 }
776
777 parent = d_obtain_alias(inode);
778 if (!IS_ERR(parent) && get_node_id(inode) != FUSE_ROOT_ID)
779 fuse_invalidate_entry_cache(parent);
780
781 return parent;
782 }
783
784 static const struct export_operations fuse_export_operations = {
785 .fh_to_dentry = fuse_fh_to_dentry,
786 .fh_to_parent = fuse_fh_to_parent,
787 .encode_fh = fuse_encode_fh,
788 .get_parent = fuse_get_parent,
789 };
790
791 static const struct super_operations fuse_super_operations = {
792 .alloc_inode = fuse_alloc_inode,
793 .destroy_inode = fuse_destroy_inode,
794 .evict_inode = fuse_evict_inode,
795 .write_inode = fuse_write_inode,
796 .drop_inode = generic_delete_inode,
797 .remount_fs = fuse_remount_fs,
798 .put_super = fuse_put_super,
799 .umount_begin = fuse_umount_begin,
800 .statfs = fuse_statfs,
801 .show_options = fuse_show_options,
802 };
803
804 static void sanitize_global_limit(unsigned *limit)
805 {
806 if (*limit == 0)
807 *limit = ((totalram_pages << PAGE_SHIFT) >> 13) /
808 sizeof(struct fuse_req);
809
810 if (*limit >= 1 << 16)
811 *limit = (1 << 16) - 1;
812 }
813
814 static int set_global_limit(const char *val, struct kernel_param *kp)
815 {
816 int rv;
817
818 rv = param_set_uint(val, kp);
819 if (rv)
820 return rv;
821
822 sanitize_global_limit((unsigned *)kp->arg);
823
824 return 0;
825 }
826
827 static void process_init_limits(struct fuse_conn *fc, struct fuse_init_out *arg)
828 {
829 int cap_sys_admin = capable(CAP_SYS_ADMIN);
830
831 if (arg->minor < 13)
832 return;
833
834 sanitize_global_limit(&max_user_bgreq);
835 sanitize_global_limit(&max_user_congthresh);
836
837 if (arg->max_background) {
838 fc->max_background = arg->max_background;
839
840 if (!cap_sys_admin && fc->max_background > max_user_bgreq)
841 fc->max_background = max_user_bgreq;
842 }
843 if (arg->congestion_threshold) {
844 fc->congestion_threshold = arg->congestion_threshold;
845
846 if (!cap_sys_admin &&
847 fc->congestion_threshold > max_user_congthresh)
848 fc->congestion_threshold = max_user_congthresh;
849 }
850 }
851
852 static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
853 {
854 struct fuse_init_out *arg = &req->misc.init_out;
855
856 if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION)
857 fc->conn_error = 1;
858 else {
859 unsigned long ra_pages;
860
861 process_init_limits(fc, arg);
862
863 if (arg->minor >= 6) {
864 ra_pages = arg->max_readahead / PAGE_CACHE_SIZE;
865 if (arg->flags & FUSE_ASYNC_READ)
866 fc->async_read = 1;
867 if (!(arg->flags & FUSE_POSIX_LOCKS))
868 fc->no_lock = 1;
869 if (arg->minor >= 17) {
870 if (!(arg->flags & FUSE_FLOCK_LOCKS))
871 fc->no_flock = 1;
872 } else {
873 if (!(arg->flags & FUSE_POSIX_LOCKS))
874 fc->no_flock = 1;
875 }
876 if (arg->flags & FUSE_ATOMIC_O_TRUNC)
877 fc->atomic_o_trunc = 1;
878 if (arg->minor >= 9) {
879 /* LOOKUP has dependency on proto version */
880 if (arg->flags & FUSE_EXPORT_SUPPORT)
881 fc->export_support = 1;
882 }
883 if (arg->flags & FUSE_BIG_WRITES)
884 fc->big_writes = 1;
885 if (arg->flags & FUSE_DONT_MASK)
886 fc->dont_mask = 1;
887 if (arg->flags & FUSE_AUTO_INVAL_DATA)
888 fc->auto_inval_data = 1;
889 if (arg->flags & FUSE_DO_READDIRPLUS) {
890 fc->do_readdirplus = 1;
891 if (arg->flags & FUSE_READDIRPLUS_AUTO)
892 fc->readdirplus_auto = 1;
893 }
894 if (arg->flags & FUSE_ASYNC_DIO)
895 fc->async_dio = 1;
896 if (arg->flags & FUSE_WRITEBACK_CACHE)
897 fc->writeback_cache = 1;
898 if (arg->time_gran && arg->time_gran <= 1000000000)
899 fc->sb->s_time_gran = arg->time_gran;
900 } else {
901 ra_pages = fc->max_read / PAGE_CACHE_SIZE;
902 fc->no_lock = 1;
903 fc->no_flock = 1;
904 }
905
906 fc->bdi.ra_pages = min(fc->bdi.ra_pages, ra_pages);
907 fc->minor = arg->minor;
908 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
909 fc->max_write = max_t(unsigned, 4096, fc->max_write);
910 fc->conn_init = 1;
911 }
912 fuse_set_initialized(fc);
913 wake_up_all(&fc->blocked_waitq);
914 }
915
916 static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req)
917 {
918 struct fuse_init_in *arg = &req->misc.init_in;
919
920 arg->major = FUSE_KERNEL_VERSION;
921 arg->minor = FUSE_KERNEL_MINOR_VERSION;
922 arg->max_readahead = fc->bdi.ra_pages * PAGE_CACHE_SIZE;
923 arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_ATOMIC_O_TRUNC |
924 FUSE_EXPORT_SUPPORT | FUSE_BIG_WRITES | FUSE_DONT_MASK |
925 FUSE_SPLICE_WRITE | FUSE_SPLICE_MOVE | FUSE_SPLICE_READ |
926 FUSE_FLOCK_LOCKS | FUSE_HAS_IOCTL_DIR | FUSE_AUTO_INVAL_DATA |
927 FUSE_DO_READDIRPLUS | FUSE_READDIRPLUS_AUTO | FUSE_ASYNC_DIO |
928 FUSE_WRITEBACK_CACHE | FUSE_NO_OPEN_SUPPORT;
929 req->in.h.opcode = FUSE_INIT;
930 req->in.numargs = 1;
931 req->in.args[0].size = sizeof(*arg);
932 req->in.args[0].value = arg;
933 req->out.numargs = 1;
934 /* Variable length argument used for backward compatibility
935 with interface version < 7.5. Rest of init_out is zeroed
936 by do_get_request(), so a short reply is not a problem */
937 req->out.argvar = 1;
938 req->out.args[0].size = sizeof(struct fuse_init_out);
939 req->out.args[0].value = &req->misc.init_out;
940 req->end = process_init_reply;
941 fuse_request_send_background(fc, req);
942 }
943
944 static void fuse_free_conn(struct fuse_conn *fc)
945 {
946 WARN_ON(!list_empty(&fc->devices));
947 kfree_rcu(fc, rcu);
948 }
949
950 static int fuse_bdi_init(struct fuse_conn *fc, struct super_block *sb)
951 {
952 int err;
953
954 fc->bdi.name = "fuse";
955 fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
956 /* fuse does it's own writeback accounting */
957 fc->bdi.capabilities = BDI_CAP_NO_ACCT_WB | BDI_CAP_STRICTLIMIT;
958
959 err = bdi_init(&fc->bdi);
960 if (err)
961 return err;
962
963 fc->bdi_initialized = 1;
964
965 if (sb->s_bdev) {
966 err = bdi_register(&fc->bdi, NULL, "%u:%u-fuseblk",
967 MAJOR(fc->dev), MINOR(fc->dev));
968 } else {
969 err = bdi_register_dev(&fc->bdi, fc->dev);
970 }
971
972 if (err)
973 return err;
974
975 /*
976 * For a single fuse filesystem use max 1% of dirty +
977 * writeback threshold.
978 *
979 * This gives about 1M of write buffer for memory maps on a
980 * machine with 1G and 10% dirty_ratio, which should be more
981 * than enough.
982 *
983 * Privileged users can raise it by writing to
984 *
985 * /sys/class/bdi/<bdi>/max_ratio
986 */
987 bdi_set_max_ratio(&fc->bdi, 1);
988
989 return 0;
990 }
991
992 struct fuse_dev *fuse_dev_alloc(struct fuse_conn *fc)
993 {
994 struct fuse_dev *fud;
995
996 fud = kzalloc(sizeof(struct fuse_dev), GFP_KERNEL);
997 if (fud) {
998 fud->fc = fuse_conn_get(fc);
999 fuse_pqueue_init(&fud->pq);
1000
1001 spin_lock(&fc->lock);
1002 list_add_tail(&fud->entry, &fc->devices);
1003 spin_unlock(&fc->lock);
1004 }
1005
1006 return fud;
1007 }
1008 EXPORT_SYMBOL_GPL(fuse_dev_alloc);
1009
1010 void fuse_dev_free(struct fuse_dev *fud)
1011 {
1012 struct fuse_conn *fc = fud->fc;
1013
1014 if (fc) {
1015 spin_lock(&fc->lock);
1016 list_del(&fud->entry);
1017 spin_unlock(&fc->lock);
1018
1019 fuse_conn_put(fc);
1020 }
1021 kfree(fud);
1022 }
1023 EXPORT_SYMBOL_GPL(fuse_dev_free);
1024
1025 static int fuse_fill_super(struct super_block *sb, void *data, int silent)
1026 {
1027 struct fuse_dev *fud;
1028 struct fuse_conn *fc;
1029 struct inode *root;
1030 struct fuse_mount_data d;
1031 struct file *file;
1032 struct dentry *root_dentry;
1033 struct fuse_req *init_req;
1034 int err;
1035 int is_bdev = sb->s_bdev != NULL;
1036
1037 err = -EINVAL;
1038 if (sb->s_flags & MS_MANDLOCK)
1039 goto err;
1040
1041 sb->s_flags &= ~(MS_NOSEC | MS_I_VERSION);
1042
1043 if (!parse_fuse_opt(data, &d, is_bdev))
1044 goto err;
1045
1046 if (is_bdev) {
1047 #ifdef CONFIG_BLOCK
1048 err = -EINVAL;
1049 if (!sb_set_blocksize(sb, d.blksize))
1050 goto err;
1051 #endif
1052 } else {
1053 sb->s_blocksize = PAGE_CACHE_SIZE;
1054 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
1055 }
1056 sb->s_magic = FUSE_SUPER_MAGIC;
1057 sb->s_op = &fuse_super_operations;
1058 sb->s_maxbytes = MAX_LFS_FILESIZE;
1059 sb->s_time_gran = 1;
1060 sb->s_export_op = &fuse_export_operations;
1061
1062 file = fget(d.fd);
1063 err = -EINVAL;
1064 if (!file)
1065 goto err;
1066
1067 if ((file->f_op != &fuse_dev_operations) ||
1068 (file->f_cred->user_ns != &init_user_ns))
1069 goto err_fput;
1070
1071 fc = kmalloc(sizeof(*fc), GFP_KERNEL);
1072 err = -ENOMEM;
1073 if (!fc)
1074 goto err_fput;
1075
1076 fuse_conn_init(fc);
1077 fc->release = fuse_free_conn;
1078
1079 fud = fuse_dev_alloc(fc);
1080 if (!fud)
1081 goto err_put_conn;
1082
1083 fc->dev = sb->s_dev;
1084 fc->sb = sb;
1085 err = fuse_bdi_init(fc, sb);
1086 if (err)
1087 goto err_dev_free;
1088
1089 sb->s_bdi = &fc->bdi;
1090
1091 /* Handle umasking inside the fuse code */
1092 if (sb->s_flags & MS_POSIXACL)
1093 fc->dont_mask = 1;
1094 sb->s_flags |= MS_POSIXACL;
1095
1096 fc->flags = d.flags;
1097 fc->user_id = d.user_id;
1098 fc->group_id = d.group_id;
1099 fc->max_read = max_t(unsigned, 4096, d.max_read);
1100
1101 /* Used by get_root_inode() */
1102 sb->s_fs_info = fc;
1103
1104 err = -ENOMEM;
1105 root = fuse_get_root_inode(sb, d.rootmode);
1106 root_dentry = d_make_root(root);
1107 if (!root_dentry)
1108 goto err_dev_free;
1109 /* only now - we want root dentry with NULL ->d_op */
1110 sb->s_d_op = &fuse_dentry_operations;
1111
1112 init_req = fuse_request_alloc(0);
1113 if (!init_req)
1114 goto err_put_root;
1115 __set_bit(FR_BACKGROUND, &init_req->flags);
1116
1117 if (is_bdev) {
1118 fc->destroy_req = fuse_request_alloc(0);
1119 if (!fc->destroy_req)
1120 goto err_free_init_req;
1121 }
1122
1123 mutex_lock(&fuse_mutex);
1124 err = -EINVAL;
1125 if (file->private_data)
1126 goto err_unlock;
1127
1128 err = fuse_ctl_add_conn(fc);
1129 if (err)
1130 goto err_unlock;
1131
1132 list_add_tail(&fc->entry, &fuse_conn_list);
1133 sb->s_root = root_dentry;
1134 file->private_data = fud;
1135 mutex_unlock(&fuse_mutex);
1136 /*
1137 * atomic_dec_and_test() in fput() provides the necessary
1138 * memory barrier for file->private_data to be visible on all
1139 * CPUs after this
1140 */
1141 fput(file);
1142
1143 fuse_send_init(fc, init_req);
1144
1145 return 0;
1146
1147 err_unlock:
1148 mutex_unlock(&fuse_mutex);
1149 err_free_init_req:
1150 fuse_request_free(init_req);
1151 err_put_root:
1152 dput(root_dentry);
1153 err_dev_free:
1154 fuse_dev_free(fud);
1155 err_put_conn:
1156 fuse_bdi_destroy(fc);
1157 fuse_conn_put(fc);
1158 sb->s_fs_info = NULL;
1159 err_fput:
1160 fput(file);
1161 err:
1162 return err;
1163 }
1164
1165 static struct dentry *fuse_mount(struct file_system_type *fs_type,
1166 int flags, const char *dev_name,
1167 void *raw_data)
1168 {
1169 return mount_nodev(fs_type, flags, raw_data, fuse_fill_super);
1170 }
1171
1172 static void fuse_sb_destroy(struct super_block *sb)
1173 {
1174 struct fuse_conn *fc = get_fuse_conn_super(sb);
1175
1176 if (fc) {
1177 fuse_send_destroy(fc);
1178
1179 fuse_abort_conn(fc);
1180 fuse_wait_aborted(fc);
1181
1182 down_write(&fc->killsb);
1183 fc->sb = NULL;
1184 up_write(&fc->killsb);
1185 }
1186 }
1187
1188 static void fuse_kill_sb_anon(struct super_block *sb)
1189 {
1190 fuse_sb_destroy(sb);
1191 kill_anon_super(sb);
1192 }
1193
1194 static struct file_system_type fuse_fs_type = {
1195 .owner = THIS_MODULE,
1196 .name = "fuse",
1197 .fs_flags = FS_HAS_SUBTYPE,
1198 .mount = fuse_mount,
1199 .kill_sb = fuse_kill_sb_anon,
1200 };
1201 MODULE_ALIAS_FS("fuse");
1202
1203 #ifdef CONFIG_BLOCK
1204 static struct dentry *fuse_mount_blk(struct file_system_type *fs_type,
1205 int flags, const char *dev_name,
1206 void *raw_data)
1207 {
1208 return mount_bdev(fs_type, flags, dev_name, raw_data, fuse_fill_super);
1209 }
1210
1211 static void fuse_kill_sb_blk(struct super_block *sb)
1212 {
1213 fuse_sb_destroy(sb);
1214 kill_block_super(sb);
1215 }
1216
1217 static struct file_system_type fuseblk_fs_type = {
1218 .owner = THIS_MODULE,
1219 .name = "fuseblk",
1220 .mount = fuse_mount_blk,
1221 .kill_sb = fuse_kill_sb_blk,
1222 .fs_flags = FS_REQUIRES_DEV | FS_HAS_SUBTYPE,
1223 };
1224 MODULE_ALIAS_FS("fuseblk");
1225
1226 static inline int register_fuseblk(void)
1227 {
1228 return register_filesystem(&fuseblk_fs_type);
1229 }
1230
1231 static inline void unregister_fuseblk(void)
1232 {
1233 unregister_filesystem(&fuseblk_fs_type);
1234 }
1235 #else
1236 static inline int register_fuseblk(void)
1237 {
1238 return 0;
1239 }
1240
1241 static inline void unregister_fuseblk(void)
1242 {
1243 }
1244 #endif
1245
1246 static void fuse_inode_init_once(void *foo)
1247 {
1248 struct inode *inode = foo;
1249
1250 inode_init_once(inode);
1251 }
1252
1253 static int __init fuse_fs_init(void)
1254 {
1255 int err;
1256
1257 fuse_inode_cachep = kmem_cache_create("fuse_inode",
1258 sizeof(struct fuse_inode),
1259 0, SLAB_HWCACHE_ALIGN,
1260 fuse_inode_init_once);
1261 err = -ENOMEM;
1262 if (!fuse_inode_cachep)
1263 goto out;
1264
1265 err = register_fuseblk();
1266 if (err)
1267 goto out2;
1268
1269 err = register_filesystem(&fuse_fs_type);
1270 if (err)
1271 goto out3;
1272
1273 return 0;
1274
1275 out3:
1276 unregister_fuseblk();
1277 out2:
1278 kmem_cache_destroy(fuse_inode_cachep);
1279 out:
1280 return err;
1281 }
1282
1283 static void fuse_fs_cleanup(void)
1284 {
1285 unregister_filesystem(&fuse_fs_type);
1286 unregister_fuseblk();
1287
1288 /*
1289 * Make sure all delayed rcu free inodes are flushed before we
1290 * destroy cache.
1291 */
1292 rcu_barrier();
1293 kmem_cache_destroy(fuse_inode_cachep);
1294 }
1295
1296 static struct kobject *fuse_kobj;
1297
1298 static int fuse_sysfs_init(void)
1299 {
1300 int err;
1301
1302 fuse_kobj = kobject_create_and_add("fuse", fs_kobj);
1303 if (!fuse_kobj) {
1304 err = -ENOMEM;
1305 goto out_err;
1306 }
1307
1308 err = sysfs_create_mount_point(fuse_kobj, "connections");
1309 if (err)
1310 goto out_fuse_unregister;
1311
1312 return 0;
1313
1314 out_fuse_unregister:
1315 kobject_put(fuse_kobj);
1316 out_err:
1317 return err;
1318 }
1319
1320 static void fuse_sysfs_cleanup(void)
1321 {
1322 sysfs_remove_mount_point(fuse_kobj, "connections");
1323 kobject_put(fuse_kobj);
1324 }
1325
1326 static int __init fuse_init(void)
1327 {
1328 int res;
1329
1330 printk(KERN_INFO "fuse init (API version %i.%i)\n",
1331 FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
1332
1333 INIT_LIST_HEAD(&fuse_conn_list);
1334 res = fuse_fs_init();
1335 if (res)
1336 goto err;
1337
1338 res = fuse_dev_init();
1339 if (res)
1340 goto err_fs_cleanup;
1341
1342 res = fuse_sysfs_init();
1343 if (res)
1344 goto err_dev_cleanup;
1345
1346 res = fuse_ctl_init();
1347 if (res)
1348 goto err_sysfs_cleanup;
1349
1350 sanitize_global_limit(&max_user_bgreq);
1351 sanitize_global_limit(&max_user_congthresh);
1352
1353 return 0;
1354
1355 err_sysfs_cleanup:
1356 fuse_sysfs_cleanup();
1357 err_dev_cleanup:
1358 fuse_dev_cleanup();
1359 err_fs_cleanup:
1360 fuse_fs_cleanup();
1361 err:
1362 return res;
1363 }
1364
1365 static void __exit fuse_exit(void)
1366 {
1367 printk(KERN_DEBUG "fuse exit\n");
1368
1369 fuse_ctl_cleanup();
1370 fuse_sysfs_cleanup();
1371 fuse_fs_cleanup();
1372 fuse_dev_cleanup();
1373 }
1374
1375 module_init(fuse_init);
1376 module_exit(fuse_exit);
Linux with added FPC-III support