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Merge tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm...
[linux-2.6.git] / fs / fuse / inode.c
blobd468643a68b2f4b9b9cf7ca38de529db096f89ed
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(&inode->i_data, 0);
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 if (*flags & MS_MANDLOCK)
139 return -EINVAL;
140
141 return 0;
142 }
143
144 /*
145 * ino_t is 32-bits on 32-bit arch. We have to squash the 64-bit value down
146 * so that it will fit.
147 */
148 static ino_t fuse_squash_ino(u64 ino64)
149 {
150 ino_t ino = (ino_t) ino64;
151 if (sizeof(ino_t) < sizeof(u64))
152 ino ^= ino64 >> (sizeof(u64) - sizeof(ino_t)) * 8;
153 return ino;
154 }
155
156 void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
157 u64 attr_valid)
158 {
159 struct fuse_conn *fc = get_fuse_conn(inode);
160 struct fuse_inode *fi = get_fuse_inode(inode);
161
162 fi->attr_version = ++fc->attr_version;
163 fi->i_time = attr_valid;
164
165 inode->i_ino = fuse_squash_ino(attr->ino);
166 inode->i_mode = (inode->i_mode & S_IFMT) | (attr->mode & 07777);
167 set_nlink(inode, attr->nlink);
168 inode->i_uid = make_kuid(&init_user_ns, attr->uid);
169 inode->i_gid = make_kgid(&init_user_ns, attr->gid);
170 inode->i_blocks = attr->blocks;
171 inode->i_atime.tv_sec = attr->atime;
172 inode->i_atime.tv_nsec = attr->atimensec;
173 inode->i_mtime.tv_sec = attr->mtime;
174 inode->i_mtime.tv_nsec = attr->mtimensec;
175 inode->i_ctime.tv_sec = attr->ctime;
176 inode->i_ctime.tv_nsec = attr->ctimensec;
177
178 if (attr->blksize != 0)
179 inode->i_blkbits = ilog2(attr->blksize);
180 else
181 inode->i_blkbits = inode->i_sb->s_blocksize_bits;
182
183 /*
184 * Don't set the sticky bit in i_mode, unless we want the VFS
185 * to check permissions. This prevents failures due to the
186 * check in may_delete().
187 */
188 fi->orig_i_mode = inode->i_mode;
189 if (!(fc->flags & FUSE_DEFAULT_PERMISSIONS))
190 inode->i_mode &= ~S_ISVTX;
191
192 fi->orig_ino = attr->ino;
193 }
194
195 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
196 u64 attr_valid, u64 attr_version)
197 {
198 struct fuse_conn *fc = get_fuse_conn(inode);
199 struct fuse_inode *fi = get_fuse_inode(inode);
200 loff_t oldsize;
201 struct timespec old_mtime;
202
203 spin_lock(&fc->lock);
204 if ((attr_version != 0 && fi->attr_version > attr_version) ||
205 test_bit(FUSE_I_SIZE_UNSTABLE, &fi->state)) {
206 spin_unlock(&fc->lock);
207 return;
208 }
209
210 old_mtime = inode->i_mtime;
211 fuse_change_attributes_common(inode, attr, attr_valid);
212
213 oldsize = inode->i_size;
214 i_size_write(inode, attr->size);
215 spin_unlock(&fc->lock);
216
217 if (S_ISREG(inode->i_mode)) {
218 bool inval = false;
219
220 if (oldsize != attr->size) {
221 truncate_pagecache(inode, attr->size);
222 inval = true;
223 } else if (fc->auto_inval_data) {
224 struct timespec new_mtime = {
225 .tv_sec = attr->mtime,
226 .tv_nsec = attr->mtimensec,
227 };
228
229 /*
230 * Auto inval mode also checks and invalidates if mtime
231 * has changed.
232 */
233 if (!timespec_equal(&old_mtime, &new_mtime))
234 inval = true;
235 }
236
237 if (inval)
238 invalidate_inode_pages2(inode->i_mapping);
239 }
240 }
241
242 static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
243 {
244 inode->i_mode = attr->mode & S_IFMT;
245 inode->i_size = attr->size;
246 if (S_ISREG(inode->i_mode)) {
247 fuse_init_common(inode);
248 fuse_init_file_inode(inode);
249 } else if (S_ISDIR(inode->i_mode))
250 fuse_init_dir(inode);
251 else if (S_ISLNK(inode->i_mode))
252 fuse_init_symlink(inode);
253 else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
254 S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
255 fuse_init_common(inode);
256 init_special_inode(inode, inode->i_mode,
257 new_decode_dev(attr->rdev));
258 } else
259 BUG();
260 }
261
262 int fuse_inode_eq(struct inode *inode, void *_nodeidp)
263 {
264 u64 nodeid = *(u64 *) _nodeidp;
265 if (get_node_id(inode) == nodeid)
266 return 1;
267 else
268 return 0;
269 }
270
271 static int fuse_inode_set(struct inode *inode, void *_nodeidp)
272 {
273 u64 nodeid = *(u64 *) _nodeidp;
274 get_fuse_inode(inode)->nodeid = nodeid;
275 return 0;
276 }
277
278 struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
279 int generation, struct fuse_attr *attr,
280 u64 attr_valid, u64 attr_version)
281 {
282 struct inode *inode;
283 struct fuse_inode *fi;
284 struct fuse_conn *fc = get_fuse_conn_super(sb);
285
286 retry:
287 inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid);
288 if (!inode)
289 return NULL;
290
291 if ((inode->i_state & I_NEW)) {
292 inode->i_flags |= S_NOATIME|S_NOCMTIME;
293 inode->i_generation = generation;
294 inode->i_data.backing_dev_info = &fc->bdi;
295 fuse_init_inode(inode, attr);
296 unlock_new_inode(inode);
297 } else if ((inode->i_mode ^ attr->mode) & S_IFMT) {
298 /* Inode has changed type, any I/O on the old should fail */
299 make_bad_inode(inode);
300 iput(inode);
301 goto retry;
302 }
303
304 fi = get_fuse_inode(inode);
305 spin_lock(&fc->lock);
306 fi->nlookup++;
307 spin_unlock(&fc->lock);
308 fuse_change_attributes(inode, attr, attr_valid, attr_version);
309
310 return inode;
311 }
312
313 int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid,
314 loff_t offset, loff_t len)
315 {
316 struct inode *inode;
317 pgoff_t pg_start;
318 pgoff_t pg_end;
319
320 inode = ilookup5(sb, nodeid, fuse_inode_eq, &nodeid);
321 if (!inode)
322 return -ENOENT;
323
324 fuse_invalidate_attr(inode);
325 if (offset >= 0) {
326 pg_start = offset >> PAGE_CACHE_SHIFT;
327 if (len <= 0)
328 pg_end = -1;
329 else
330 pg_end = (offset + len - 1) >> PAGE_CACHE_SHIFT;
331 invalidate_inode_pages2_range(inode->i_mapping,
332 pg_start, pg_end);
333 }
334 iput(inode);
335 return 0;
336 }
337
338 static void fuse_umount_begin(struct super_block *sb)
339 {
340 fuse_abort_conn(get_fuse_conn_super(sb));
341 }
342
343 static void fuse_send_destroy(struct fuse_conn *fc)
344 {
345 struct fuse_req *req = fc->destroy_req;
346 if (req && fc->conn_init) {
347 fc->destroy_req = NULL;
348 req->in.h.opcode = FUSE_DESTROY;
349 req->force = 1;
350 req->background = 0;
351 fuse_request_send(fc, req);
352 fuse_put_request(fc, req);
353 }
354 }
355
356 static void fuse_bdi_destroy(struct fuse_conn *fc)
357 {
358 if (fc->bdi_initialized)
359 bdi_destroy(&fc->bdi);
360 }
361
362 void fuse_conn_kill(struct fuse_conn *fc)
363 {
364 spin_lock(&fc->lock);
365 fc->connected = 0;
366 fc->blocked = 0;
367 fc->initialized = 1;
368 spin_unlock(&fc->lock);
369 /* Flush all readers on this fs */
370 kill_fasync(&fc->fasync, SIGIO, POLL_IN);
371 wake_up_all(&fc->waitq);
372 wake_up_all(&fc->blocked_waitq);
373 wake_up_all(&fc->reserved_req_waitq);
374 }
375 EXPORT_SYMBOL_GPL(fuse_conn_kill);
376
377 static void fuse_put_super(struct super_block *sb)
378 {
379 struct fuse_conn *fc = get_fuse_conn_super(sb);
380
381 fuse_send_destroy(fc);
382
383 fuse_conn_kill(fc);
384 mutex_lock(&fuse_mutex);
385 list_del(&fc->entry);
386 fuse_ctl_remove_conn(fc);
387 mutex_unlock(&fuse_mutex);
388 fuse_bdi_destroy(fc);
389
390 fuse_conn_put(fc);
391 }
392
393 static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
394 {
395 stbuf->f_type = FUSE_SUPER_MAGIC;
396 stbuf->f_bsize = attr->bsize;
397 stbuf->f_frsize = attr->frsize;
398 stbuf->f_blocks = attr->blocks;
399 stbuf->f_bfree = attr->bfree;
400 stbuf->f_bavail = attr->bavail;
401 stbuf->f_files = attr->files;
402 stbuf->f_ffree = attr->ffree;
403 stbuf->f_namelen = attr->namelen;
404 /* fsid is left zero */
405 }
406
407 static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf)
408 {
409 struct super_block *sb = dentry->d_sb;
410 struct fuse_conn *fc = get_fuse_conn_super(sb);
411 struct fuse_req *req;
412 struct fuse_statfs_out outarg;
413 int err;
414
415 if (!fuse_allow_current_process(fc)) {
416 buf->f_type = FUSE_SUPER_MAGIC;
417 return 0;
418 }
419
420 req = fuse_get_req_nopages(fc);
421 if (IS_ERR(req))
422 return PTR_ERR(req);
423
424 memset(&outarg, 0, sizeof(outarg));
425 req->in.numargs = 0;
426 req->in.h.opcode = FUSE_STATFS;
427 req->in.h.nodeid = get_node_id(dentry->d_inode);
428 req->out.numargs = 1;
429 req->out.args[0].size =
430 fc->minor < 4 ? FUSE_COMPAT_STATFS_SIZE : sizeof(outarg);
431 req->out.args[0].value = &outarg;
432 fuse_request_send(fc, req);
433 err = req->out.h.error;
434 if (!err)
435 convert_fuse_statfs(buf, &outarg.st);
436 fuse_put_request(fc, req);
437 return err;
438 }
439
440 enum {
441 OPT_FD,
442 OPT_ROOTMODE,
443 OPT_USER_ID,
444 OPT_GROUP_ID,
445 OPT_DEFAULT_PERMISSIONS,
446 OPT_ALLOW_OTHER,
447 OPT_MAX_READ,
448 OPT_BLKSIZE,
449 OPT_ERR
450 };
451
452 static const match_table_t tokens = {
453 {OPT_FD, "fd=%u"},
454 {OPT_ROOTMODE, "rootmode=%o"},
455 {OPT_USER_ID, "user_id=%u"},
456 {OPT_GROUP_ID, "group_id=%u"},
457 {OPT_DEFAULT_PERMISSIONS, "default_permissions"},
458 {OPT_ALLOW_OTHER, "allow_other"},
459 {OPT_MAX_READ, "max_read=%u"},
460 {OPT_BLKSIZE, "blksize=%u"},
461 {OPT_ERR, NULL}
462 };
463
464 static int parse_fuse_opt(char *opt, struct fuse_mount_data *d, int is_bdev)
465 {
466 char *p;
467 memset(d, 0, sizeof(struct fuse_mount_data));
468 d->max_read = ~0;
469 d->blksize = FUSE_DEFAULT_BLKSIZE;
470
471 while ((p = strsep(&opt, ",")) != NULL) {
472 int token;
473 int value;
474 substring_t args[MAX_OPT_ARGS];
475 if (!*p)
476 continue;
477
478 token = match_token(p, tokens, args);
479 switch (token) {
480 case OPT_FD:
481 if (match_int(&args[0], &value))
482 return 0;
483 d->fd = value;
484 d->fd_present = 1;
485 break;
486
487 case OPT_ROOTMODE:
488 if (match_octal(&args[0], &value))
489 return 0;
490 if (!fuse_valid_type(value))
491 return 0;
492 d->rootmode = value;
493 d->rootmode_present = 1;
494 break;
495
496 case OPT_USER_ID:
497 if (match_int(&args[0], &value))
498 return 0;
499 d->user_id = make_kuid(current_user_ns(), value);
500 if (!uid_valid(d->user_id))
501 return 0;
502 d->user_id_present = 1;
503 break;
504
505 case OPT_GROUP_ID:
506 if (match_int(&args[0], &value))
507 return 0;
508 d->group_id = make_kgid(current_user_ns(), value);
509 if (!gid_valid(d->group_id))
510 return 0;
511 d->group_id_present = 1;
512 break;
513
514 case OPT_DEFAULT_PERMISSIONS:
515 d->flags |= FUSE_DEFAULT_PERMISSIONS;
516 break;
517
518 case OPT_ALLOW_OTHER:
519 d->flags |= FUSE_ALLOW_OTHER;
520 break;
521
522 case OPT_MAX_READ:
523 if (match_int(&args[0], &value))
524 return 0;
525 d->max_read = value;
526 break;
527
528 case OPT_BLKSIZE:
529 if (!is_bdev || match_int(&args[0], &value))
530 return 0;
531 d->blksize = value;
532 break;
533
534 default:
535 return 0;
536 }
537 }
538
539 if (!d->fd_present || !d->rootmode_present ||
540 !d->user_id_present || !d->group_id_present)
541 return 0;
542
543 return 1;
544 }
545
546 static int fuse_show_options(struct seq_file *m, struct dentry *root)
547 {
548 struct super_block *sb = root->d_sb;
549 struct fuse_conn *fc = get_fuse_conn_super(sb);
550
551 seq_printf(m, ",user_id=%u", from_kuid_munged(&init_user_ns, fc->user_id));
552 seq_printf(m, ",group_id=%u", from_kgid_munged(&init_user_ns, fc->group_id));
553 if (fc->flags & FUSE_DEFAULT_PERMISSIONS)
554 seq_puts(m, ",default_permissions");
555 if (fc->flags & FUSE_ALLOW_OTHER)
556 seq_puts(m, ",allow_other");
557 if (fc->max_read != ~0)
558 seq_printf(m, ",max_read=%u", fc->max_read);
559 if (sb->s_bdev && sb->s_blocksize != FUSE_DEFAULT_BLKSIZE)
560 seq_printf(m, ",blksize=%lu", sb->s_blocksize);
561 return 0;
562 }
563
564 void fuse_conn_init(struct fuse_conn *fc)
565 {
566 memset(fc, 0, sizeof(*fc));
567 spin_lock_init(&fc->lock);
568 init_rwsem(&fc->killsb);
569 atomic_set(&fc->count, 1);
570 init_waitqueue_head(&fc->waitq);
571 init_waitqueue_head(&fc->blocked_waitq);
572 init_waitqueue_head(&fc->reserved_req_waitq);
573 INIT_LIST_HEAD(&fc->pending);
574 INIT_LIST_HEAD(&fc->processing);
575 INIT_LIST_HEAD(&fc->io);
576 INIT_LIST_HEAD(&fc->interrupts);
577 INIT_LIST_HEAD(&fc->bg_queue);
578 INIT_LIST_HEAD(&fc->entry);
579 fc->forget_list_tail = &fc->forget_list_head;
580 atomic_set(&fc->num_waiting, 0);
581 fc->max_background = FUSE_DEFAULT_MAX_BACKGROUND;
582 fc->congestion_threshold = FUSE_DEFAULT_CONGESTION_THRESHOLD;
583 fc->khctr = 0;
584 fc->polled_files = RB_ROOT;
585 fc->reqctr = 0;
586 fc->blocked = 0;
587 fc->initialized = 0;
588 fc->attr_version = 1;
589 get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key));
590 }
591 EXPORT_SYMBOL_GPL(fuse_conn_init);
592
593 void fuse_conn_put(struct fuse_conn *fc)
594 {
595 if (atomic_dec_and_test(&fc->count)) {
596 if (fc->destroy_req)
597 fuse_request_free(fc->destroy_req);
598 fc->release(fc);
599 }
600 }
601 EXPORT_SYMBOL_GPL(fuse_conn_put);
602
603 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc)
604 {
605 atomic_inc(&fc->count);
606 return fc;
607 }
608 EXPORT_SYMBOL_GPL(fuse_conn_get);
609
610 static struct inode *fuse_get_root_inode(struct super_block *sb, unsigned mode)
611 {
612 struct fuse_attr attr;
613 memset(&attr, 0, sizeof(attr));
614
615 attr.mode = mode;
616 attr.ino = FUSE_ROOT_ID;
617 attr.nlink = 1;
618 return fuse_iget(sb, 1, 0, &attr, 0, 0);
619 }
620
621 struct fuse_inode_handle {
622 u64 nodeid;
623 u32 generation;
624 };
625
626 static struct dentry *fuse_get_dentry(struct super_block *sb,
627 struct fuse_inode_handle *handle)
628 {
629 struct fuse_conn *fc = get_fuse_conn_super(sb);
630 struct inode *inode;
631 struct dentry *entry;
632 int err = -ESTALE;
633
634 if (handle->nodeid == 0)
635 goto out_err;
636
637 inode = ilookup5(sb, handle->nodeid, fuse_inode_eq, &handle->nodeid);
638 if (!inode) {
639 struct fuse_entry_out outarg;
640 struct qstr name;
641
642 if (!fc->export_support)
643 goto out_err;
644
645 name.len = 1;
646 name.name = ".";
647 err = fuse_lookup_name(sb, handle->nodeid, &name, &outarg,
648 &inode);
649 if (err && err != -ENOENT)
650 goto out_err;
651 if (err || !inode) {
652 err = -ESTALE;
653 goto out_err;
654 }
655 err = -EIO;
656 if (get_node_id(inode) != handle->nodeid)
657 goto out_iput;
658 }
659 err = -ESTALE;
660 if (inode->i_generation != handle->generation)
661 goto out_iput;
662
663 entry = d_obtain_alias(inode);
664 if (!IS_ERR(entry) && get_node_id(inode) != FUSE_ROOT_ID)
665 fuse_invalidate_entry_cache(entry);
666
667 return entry;
668
669 out_iput:
670 iput(inode);
671 out_err:
672 return ERR_PTR(err);
673 }
674
675 static int fuse_encode_fh(struct inode *inode, u32 *fh, int *max_len,
676 struct inode *parent)
677 {
678 int len = parent ? 6 : 3;
679 u64 nodeid;
680 u32 generation;
681
682 if (*max_len < len) {
683 *max_len = len;
684 return FILEID_INVALID;
685 }
686
687 nodeid = get_fuse_inode(inode)->nodeid;
688 generation = inode->i_generation;
689
690 fh[0] = (u32)(nodeid >> 32);
691 fh[1] = (u32)(nodeid & 0xffffffff);
692 fh[2] = generation;
693
694 if (parent) {
695 nodeid = get_fuse_inode(parent)->nodeid;
696 generation = parent->i_generation;
697
698 fh[3] = (u32)(nodeid >> 32);
699 fh[4] = (u32)(nodeid & 0xffffffff);
700 fh[5] = generation;
701 }
702
703 *max_len = len;
704 return parent ? 0x82 : 0x81;
705 }
706
707 static struct dentry *fuse_fh_to_dentry(struct super_block *sb,
708 struct fid *fid, int fh_len, int fh_type)
709 {
710 struct fuse_inode_handle handle;
711
712 if ((fh_type != 0x81 && fh_type != 0x82) || fh_len < 3)
713 return NULL;
714
715 handle.nodeid = (u64) fid->raw[0] << 32;
716 handle.nodeid |= (u64) fid->raw[1];
717 handle.generation = fid->raw[2];
718 return fuse_get_dentry(sb, &handle);
719 }
720
721 static struct dentry *fuse_fh_to_parent(struct super_block *sb,
722 struct fid *fid, int fh_len, int fh_type)
723 {
724 struct fuse_inode_handle parent;
725
726 if (fh_type != 0x82 || fh_len < 6)
727 return NULL;
728
729 parent.nodeid = (u64) fid->raw[3] << 32;
730 parent.nodeid |= (u64) fid->raw[4];
731 parent.generation = fid->raw[5];
732 return fuse_get_dentry(sb, &parent);
733 }
734
735 static struct dentry *fuse_get_parent(struct dentry *child)
736 {
737 struct inode *child_inode = child->d_inode;
738 struct fuse_conn *fc = get_fuse_conn(child_inode);
739 struct inode *inode;
740 struct dentry *parent;
741 struct fuse_entry_out outarg;
742 struct qstr name;
743 int err;
744
745 if (!fc->export_support)
746 return ERR_PTR(-ESTALE);
747
748 name.len = 2;
749 name.name = "..";
750 err = fuse_lookup_name(child_inode->i_sb, get_node_id(child_inode),
751 &name, &outarg, &inode);
752 if (err) {
753 if (err == -ENOENT)
754 return ERR_PTR(-ESTALE);
755 return ERR_PTR(err);
756 }
757
758 parent = d_obtain_alias(inode);
759 if (!IS_ERR(parent) && get_node_id(inode) != FUSE_ROOT_ID)
760 fuse_invalidate_entry_cache(parent);
761
762 return parent;
763 }
764
765 static const struct export_operations fuse_export_operations = {
766 .fh_to_dentry = fuse_fh_to_dentry,
767 .fh_to_parent = fuse_fh_to_parent,
768 .encode_fh = fuse_encode_fh,
769 .get_parent = fuse_get_parent,
770 };
771
772 static const struct super_operations fuse_super_operations = {
773 .alloc_inode = fuse_alloc_inode,
774 .destroy_inode = fuse_destroy_inode,
775 .evict_inode = fuse_evict_inode,
776 .drop_inode = generic_delete_inode,
777 .remount_fs = fuse_remount_fs,
778 .put_super = fuse_put_super,
779 .umount_begin = fuse_umount_begin,
780 .statfs = fuse_statfs,
781 .show_options = fuse_show_options,
782 };
783
784 static void sanitize_global_limit(unsigned *limit)
785 {
786 if (*limit == 0)
787 *limit = ((totalram_pages << PAGE_SHIFT) >> 13) /
788 sizeof(struct fuse_req);
789
790 if (*limit >= 1 << 16)
791 *limit = (1 << 16) - 1;
792 }
793
794 static int set_global_limit(const char *val, struct kernel_param *kp)
795 {
796 int rv;
797
798 rv = param_set_uint(val, kp);
799 if (rv)
800 return rv;
801
802 sanitize_global_limit((unsigned *)kp->arg);
803
804 return 0;
805 }
806
807 static void process_init_limits(struct fuse_conn *fc, struct fuse_init_out *arg)
808 {
809 int cap_sys_admin = capable(CAP_SYS_ADMIN);
810
811 if (arg->minor < 13)
812 return;
813
814 sanitize_global_limit(&max_user_bgreq);
815 sanitize_global_limit(&max_user_congthresh);
816
817 if (arg->max_background) {
818 fc->max_background = arg->max_background;
819
820 if (!cap_sys_admin && fc->max_background > max_user_bgreq)
821 fc->max_background = max_user_bgreq;
822 }
823 if (arg->congestion_threshold) {
824 fc->congestion_threshold = arg->congestion_threshold;
825
826 if (!cap_sys_admin &&
827 fc->congestion_threshold > max_user_congthresh)
828 fc->congestion_threshold = max_user_congthresh;
829 }
830 }
831
832 static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
833 {
834 struct fuse_init_out *arg = &req->misc.init_out;
835
836 if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION)
837 fc->conn_error = 1;
838 else {
839 unsigned long ra_pages;
840
841 process_init_limits(fc, arg);
842
843 if (arg->minor >= 6) {
844 ra_pages = arg->max_readahead / PAGE_CACHE_SIZE;
845 if (arg->flags & FUSE_ASYNC_READ)
846 fc->async_read = 1;
847 if (!(arg->flags & FUSE_POSIX_LOCKS))
848 fc->no_lock = 1;
849 if (arg->minor >= 17) {
850 if (!(arg->flags & FUSE_FLOCK_LOCKS))
851 fc->no_flock = 1;
852 } else {
853 if (!(arg->flags & FUSE_POSIX_LOCKS))
854 fc->no_flock = 1;
855 }
856 if (arg->flags & FUSE_ATOMIC_O_TRUNC)
857 fc->atomic_o_trunc = 1;
858 if (arg->minor >= 9) {
859 /* LOOKUP has dependency on proto version */
860 if (arg->flags & FUSE_EXPORT_SUPPORT)
861 fc->export_support = 1;
862 }
863 if (arg->flags & FUSE_BIG_WRITES)
864 fc->big_writes = 1;
865 if (arg->flags & FUSE_DONT_MASK)
866 fc->dont_mask = 1;
867 if (arg->flags & FUSE_AUTO_INVAL_DATA)
868 fc->auto_inval_data = 1;
869 if (arg->flags & FUSE_DO_READDIRPLUS) {
870 fc->do_readdirplus = 1;
871 if (arg->flags & FUSE_READDIRPLUS_AUTO)
872 fc->readdirplus_auto = 1;
873 }
874 if (arg->flags & FUSE_ASYNC_DIO)
875 fc->async_dio = 1;
876 } else {
877 ra_pages = fc->max_read / PAGE_CACHE_SIZE;
878 fc->no_lock = 1;
879 fc->no_flock = 1;
880 }
881
882 fc->bdi.ra_pages = min(fc->bdi.ra_pages, ra_pages);
883 fc->minor = arg->minor;
884 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
885 fc->max_write = max_t(unsigned, 4096, fc->max_write);
886 fc->conn_init = 1;
887 }
888 fc->initialized = 1;
889 wake_up_all(&fc->blocked_waitq);
890 }
891
892 static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req)
893 {
894 struct fuse_init_in *arg = &req->misc.init_in;
895
896 arg->major = FUSE_KERNEL_VERSION;
897 arg->minor = FUSE_KERNEL_MINOR_VERSION;
898 arg->max_readahead = fc->bdi.ra_pages * PAGE_CACHE_SIZE;
899 arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_ATOMIC_O_TRUNC |
900 FUSE_EXPORT_SUPPORT | FUSE_BIG_WRITES | FUSE_DONT_MASK |
901 FUSE_SPLICE_WRITE | FUSE_SPLICE_MOVE | FUSE_SPLICE_READ |
902 FUSE_FLOCK_LOCKS | FUSE_IOCTL_DIR | FUSE_AUTO_INVAL_DATA |
903 FUSE_DO_READDIRPLUS | FUSE_READDIRPLUS_AUTO | FUSE_ASYNC_DIO;
904 req->in.h.opcode = FUSE_INIT;
905 req->in.numargs = 1;
906 req->in.args[0].size = sizeof(*arg);
907 req->in.args[0].value = arg;
908 req->out.numargs = 1;
909 /* Variable length argument used for backward compatibility
910 with interface version < 7.5. Rest of init_out is zeroed
911 by do_get_request(), so a short reply is not a problem */
912 req->out.argvar = 1;
913 req->out.args[0].size = sizeof(struct fuse_init_out);
914 req->out.args[0].value = &req->misc.init_out;
915 req->end = process_init_reply;
916 fuse_request_send_background(fc, req);
917 }
918
919 static void fuse_free_conn(struct fuse_conn *fc)
920 {
921 kfree_rcu(fc, rcu);
922 }
923
924 static int fuse_bdi_init(struct fuse_conn *fc, struct super_block *sb)
925 {
926 int err;
927
928 fc->bdi.name = "fuse";
929 fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
930 /* fuse does it's own writeback accounting */
931 fc->bdi.capabilities = BDI_CAP_NO_ACCT_WB | BDI_CAP_STRICTLIMIT;
932
933 err = bdi_init(&fc->bdi);
934 if (err)
935 return err;
936
937 fc->bdi_initialized = 1;
938
939 if (sb->s_bdev) {
940 err = bdi_register(&fc->bdi, NULL, "%u:%u-fuseblk",
941 MAJOR(fc->dev), MINOR(fc->dev));
942 } else {
943 err = bdi_register_dev(&fc->bdi, fc->dev);
944 }
945
946 if (err)
947 return err;
948
949 /*
950 * For a single fuse filesystem use max 1% of dirty +
951 * writeback threshold.
952 *
953 * This gives about 1M of write buffer for memory maps on a
954 * machine with 1G and 10% dirty_ratio, which should be more
955 * than enough.
956 *
957 * Privileged users can raise it by writing to
958 *
959 * /sys/class/bdi/<bdi>/max_ratio
960 */
961 bdi_set_max_ratio(&fc->bdi, 1);
962
963 return 0;
964 }
965
966 static int fuse_fill_super(struct super_block *sb, void *data, int silent)
967 {
968 struct fuse_conn *fc;
969 struct inode *root;
970 struct fuse_mount_data d;
971 struct file *file;
972 struct dentry *root_dentry;
973 struct fuse_req *init_req;
974 int err;
975 int is_bdev = sb->s_bdev != NULL;
976
977 err = -EINVAL;
978 if (sb->s_flags & MS_MANDLOCK)
979 goto err;
980
981 sb->s_flags &= ~MS_NOSEC;
982
983 if (!parse_fuse_opt((char *) data, &d, is_bdev))
984 goto err;
985
986 if (is_bdev) {
987 #ifdef CONFIG_BLOCK
988 err = -EINVAL;
989 if (!sb_set_blocksize(sb, d.blksize))
990 goto err;
991 #endif
992 } else {
993 sb->s_blocksize = PAGE_CACHE_SIZE;
994 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
995 }
996 sb->s_magic = FUSE_SUPER_MAGIC;
997 sb->s_op = &fuse_super_operations;
998 sb->s_maxbytes = MAX_LFS_FILESIZE;
999 sb->s_time_gran = 1;
1000 sb->s_export_op = &fuse_export_operations;
1001
1002 file = fget(d.fd);
1003 err = -EINVAL;
1004 if (!file)
1005 goto err;
1006
1007 if ((file->f_op != &fuse_dev_operations) ||
1008 (file->f_cred->user_ns != &init_user_ns))
1009 goto err_fput;
1010
1011 fc = kmalloc(sizeof(*fc), GFP_KERNEL);
1012 err = -ENOMEM;
1013 if (!fc)
1014 goto err_fput;
1015
1016 fuse_conn_init(fc);
1017
1018 fc->dev = sb->s_dev;
1019 fc->sb = sb;
1020 err = fuse_bdi_init(fc, sb);
1021 if (err)
1022 goto err_put_conn;
1023
1024 sb->s_bdi = &fc->bdi;
1025
1026 /* Handle umasking inside the fuse code */
1027 if (sb->s_flags & MS_POSIXACL)
1028 fc->dont_mask = 1;
1029 sb->s_flags |= MS_POSIXACL;
1030
1031 fc->release = fuse_free_conn;
1032 fc->flags = d.flags;
1033 fc->user_id = d.user_id;
1034 fc->group_id = d.group_id;
1035 fc->max_read = max_t(unsigned, 4096, d.max_read);
1036
1037 /* Used by get_root_inode() */
1038 sb->s_fs_info = fc;
1039
1040 err = -ENOMEM;
1041 root = fuse_get_root_inode(sb, d.rootmode);
1042 root_dentry = d_make_root(root);
1043 if (!root_dentry)
1044 goto err_put_conn;
1045 /* only now - we want root dentry with NULL ->d_op */
1046 sb->s_d_op = &fuse_dentry_operations;
1047
1048 init_req = fuse_request_alloc(0);
1049 if (!init_req)
1050 goto err_put_root;
1051 init_req->background = 1;
1052
1053 if (is_bdev) {
1054 fc->destroy_req = fuse_request_alloc(0);
1055 if (!fc->destroy_req)
1056 goto err_free_init_req;
1057 }
1058
1059 mutex_lock(&fuse_mutex);
1060 err = -EINVAL;
1061 if (file->private_data)
1062 goto err_unlock;
1063
1064 err = fuse_ctl_add_conn(fc);
1065 if (err)
1066 goto err_unlock;
1067
1068 list_add_tail(&fc->entry, &fuse_conn_list);
1069 sb->s_root = root_dentry;
1070 fc->connected = 1;
1071 file->private_data = fuse_conn_get(fc);
1072 mutex_unlock(&fuse_mutex);
1073 /*
1074 * atomic_dec_and_test() in fput() provides the necessary
1075 * memory barrier for file->private_data to be visible on all
1076 * CPUs after this
1077 */
1078 fput(file);
1079
1080 fuse_send_init(fc, init_req);
1081
1082 return 0;
1083
1084 err_unlock:
1085 mutex_unlock(&fuse_mutex);
1086 err_free_init_req:
1087 fuse_request_free(init_req);
1088 err_put_root:
1089 dput(root_dentry);
1090 err_put_conn:
1091 fuse_bdi_destroy(fc);
1092 fuse_conn_put(fc);
1093 err_fput:
1094 fput(file);
1095 err:
1096 return err;
1097 }
1098
1099 static struct dentry *fuse_mount(struct file_system_type *fs_type,
1100 int flags, const char *dev_name,
1101 void *raw_data)
1102 {
1103 return mount_nodev(fs_type, flags, raw_data, fuse_fill_super);
1104 }
1105
1106 static void fuse_kill_sb_anon(struct super_block *sb)
1107 {
1108 struct fuse_conn *fc = get_fuse_conn_super(sb);
1109
1110 if (fc) {
1111 down_write(&fc->killsb);
1112 fc->sb = NULL;
1113 up_write(&fc->killsb);
1114 }
1115
1116 kill_anon_super(sb);
1117 }
1118
1119 static struct file_system_type fuse_fs_type = {
1120 .owner = THIS_MODULE,
1121 .name = "fuse",
1122 .fs_flags = FS_HAS_SUBTYPE,
1123 .mount = fuse_mount,
1124 .kill_sb = fuse_kill_sb_anon,
1125 };
1126 MODULE_ALIAS_FS("fuse");
1127
1128 #ifdef CONFIG_BLOCK
1129 static struct dentry *fuse_mount_blk(struct file_system_type *fs_type,
1130 int flags, const char *dev_name,
1131 void *raw_data)
1132 {
1133 return mount_bdev(fs_type, flags, dev_name, raw_data, fuse_fill_super);
1134 }
1135
1136 static void fuse_kill_sb_blk(struct super_block *sb)
1137 {
1138 struct fuse_conn *fc = get_fuse_conn_super(sb);
1139
1140 if (fc) {
1141 down_write(&fc->killsb);
1142 fc->sb = NULL;
1143 up_write(&fc->killsb);
1144 }
1145
1146 kill_block_super(sb);
1147 }
1148
1149 static struct file_system_type fuseblk_fs_type = {
1150 .owner = THIS_MODULE,
1151 .name = "fuseblk",
1152 .mount = fuse_mount_blk,
1153 .kill_sb = fuse_kill_sb_blk,
1154 .fs_flags = FS_REQUIRES_DEV | FS_HAS_SUBTYPE,
1155 };
1156 MODULE_ALIAS_FS("fuseblk");
1157
1158 static inline int register_fuseblk(void)
1159 {
1160 return register_filesystem(&fuseblk_fs_type);
1161 }
1162
1163 static inline void unregister_fuseblk(void)
1164 {
1165 unregister_filesystem(&fuseblk_fs_type);
1166 }
1167 #else
1168 static inline int register_fuseblk(void)
1169 {
1170 return 0;
1171 }
1172
1173 static inline void unregister_fuseblk(void)
1174 {
1175 }
1176 #endif
1177
1178 static void fuse_inode_init_once(void *foo)
1179 {
1180 struct inode *inode = foo;
1181
1182 inode_init_once(inode);
1183 }
1184
1185 static int __init fuse_fs_init(void)
1186 {
1187 int err;
1188
1189 fuse_inode_cachep = kmem_cache_create("fuse_inode",
1190 sizeof(struct fuse_inode),
1191 0, SLAB_HWCACHE_ALIGN,
1192 fuse_inode_init_once);
1193 err = -ENOMEM;
1194 if (!fuse_inode_cachep)
1195 goto out;
1196
1197 err = register_fuseblk();
1198 if (err)
1199 goto out2;
1200
1201 err = register_filesystem(&fuse_fs_type);
1202 if (err)
1203 goto out3;
1204
1205 return 0;
1206
1207 out3:
1208 unregister_fuseblk();
1209 out2:
1210 kmem_cache_destroy(fuse_inode_cachep);
1211 out:
1212 return err;
1213 }
1214
1215 static void fuse_fs_cleanup(void)
1216 {
1217 unregister_filesystem(&fuse_fs_type);
1218 unregister_fuseblk();
1219
1220 /*
1221 * Make sure all delayed rcu free inodes are flushed before we
1222 * destroy cache.
1223 */
1224 rcu_barrier();
1225 kmem_cache_destroy(fuse_inode_cachep);
1226 }
1227
1228 static struct kobject *fuse_kobj;
1229 static struct kobject *connections_kobj;
1230
1231 static int fuse_sysfs_init(void)
1232 {
1233 int err;
1234
1235 fuse_kobj = kobject_create_and_add("fuse", fs_kobj);
1236 if (!fuse_kobj) {
1237 err = -ENOMEM;
1238 goto out_err;
1239 }
1240
1241 connections_kobj = kobject_create_and_add("connections", fuse_kobj);
1242 if (!connections_kobj) {
1243 err = -ENOMEM;
1244 goto out_fuse_unregister;
1245 }
1246
1247 return 0;
1248
1249 out_fuse_unregister:
1250 kobject_put(fuse_kobj);
1251 out_err:
1252 return err;
1253 }
1254
1255 static void fuse_sysfs_cleanup(void)
1256 {
1257 kobject_put(connections_kobj);
1258 kobject_put(fuse_kobj);
1259 }
1260
1261 static int __init fuse_init(void)
1262 {
1263 int res;
1264
1265 printk(KERN_INFO "fuse init (API version %i.%i)\n",
1266 FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
1267
1268 INIT_LIST_HEAD(&fuse_conn_list);
1269 res = fuse_fs_init();
1270 if (res)
1271 goto err;
1272
1273 res = fuse_dev_init();
1274 if (res)
1275 goto err_fs_cleanup;
1276
1277 res = fuse_sysfs_init();
1278 if (res)
1279 goto err_dev_cleanup;
1280
1281 res = fuse_ctl_init();
1282 if (res)
1283 goto err_sysfs_cleanup;
1284
1285 sanitize_global_limit(&max_user_bgreq);
1286 sanitize_global_limit(&max_user_congthresh);
1287
1288 return 0;
1289
1290 err_sysfs_cleanup:
1291 fuse_sysfs_cleanup();
1292 err_dev_cleanup:
1293 fuse_dev_cleanup();
1294 err_fs_cleanup:
1295 fuse_fs_cleanup();
1296 err:
1297 return res;
1298 }
1299
1300 static void __exit fuse_exit(void)
1301 {
1302 printk(KERN_DEBUG "fuse exit\n");
1303
1304 fuse_ctl_cleanup();
1305 fuse_sysfs_cleanup();
1306 fuse_fs_cleanup();
1307 fuse_dev_cleanup();
1308 }
1309
1310 module_init(fuse_init);
1311 module_exit(fuse_exit);
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