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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
24MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>");
25MODULE_DESCRIPTION("Filesystem in Userspace");
26MODULE_LICENSE("GPL");
27
28static struct kmem_cache *fuse_inode_cachep;
29struct list_head fuse_conn_list;
30DEFINE_MUTEX(fuse_mutex);
31
32static int set_global_limit(const char *val, struct kernel_param *kp);
33
34unsigned max_user_bgreq;
35module_param_call(max_user_bgreq, set_global_limit, param_get_uint,
36 &max_user_bgreq, 0644);
37__MODULE_PARM_TYPE(max_user_bgreq, "uint");
38MODULE_PARM_DESC(max_user_bgreq,
39 "Global limit for the maximum number of backgrounded requests an "
40 "unprivileged user can set");
41
42unsigned max_user_congthresh;
43module_param_call(max_user_congthresh, set_global_limit, param_get_uint,
44 &max_user_congthresh, 0644);
45__MODULE_PARM_TYPE(max_user_congthresh, "uint");
46MODULE_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
60struct fuse_mount_data {
61 int fd;
62 unsigned rootmode;
63 unsigned user_id;
64 unsigned 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
74struct fuse_forget_link *fuse_alloc_forget(void)
75{
76 return kzalloc(sizeof(struct fuse_forget_link), GFP_KERNEL);
77}
78
79static 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 INIT_LIST_HEAD(&fi->write_files);
96 INIT_LIST_HEAD(&fi->queued_writes);
97 INIT_LIST_HEAD(&fi->writepages);
98 init_waitqueue_head(&fi->page_waitq);
99 fi->forget = fuse_alloc_forget();
100 if (!fi->forget) {
101 kmem_cache_free(fuse_inode_cachep, inode);
102 return NULL;
103 }
104
105 return inode;
106}
107
108static void fuse_i_callback(struct rcu_head *head)
109{
110 struct inode *inode = container_of(head, struct inode, i_rcu);
111 kmem_cache_free(fuse_inode_cachep, inode);
112}
113
114static void fuse_destroy_inode(struct inode *inode)
115{
116 struct fuse_inode *fi = get_fuse_inode(inode);
117 BUG_ON(!list_empty(&fi->write_files));
118 BUG_ON(!list_empty(&fi->queued_writes));
119 kfree(fi->forget);
120 call_rcu(&inode->i_rcu, fuse_i_callback);
121}
122
123static void fuse_evict_inode(struct inode *inode)
124{
125 truncate_inode_pages(&inode->i_data, 0);
126 clear_inode(inode);
127 if (inode->i_sb->s_flags & MS_ACTIVE) {
128 struct fuse_conn *fc = get_fuse_conn(inode);
129 struct fuse_inode *fi = get_fuse_inode(inode);
130 fuse_queue_forget(fc, fi->forget, fi->nodeid, fi->nlookup);
131 fi->forget = NULL;
132 }
133}
134
135static int fuse_remount_fs(struct super_block *sb, int *flags, char *data)
136{
137 if (*flags & MS_MANDLOCK)
138 return -EINVAL;
139
140 return 0;
141}
142
143/*
144 * ino_t is 32-bits on 32-bit arch. We have to squash the 64-bit value down
145 * so that it will fit.
146 */
147static ino_t fuse_squash_ino(u64 ino64)
148{
149 ino_t ino = (ino_t) ino64;
150 if (sizeof(ino_t) < sizeof(u64))
151 ino ^= ino64 >> (sizeof(u64) - sizeof(ino_t)) * 8;
152 return ino;
153}
154
155void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
156 u64 attr_valid)
157{
158 struct fuse_conn *fc = get_fuse_conn(inode);
159 struct fuse_inode *fi = get_fuse_inode(inode);
160
161 fi->attr_version = ++fc->attr_version;
162 fi->i_time = attr_valid;
163
164 inode->i_ino = fuse_squash_ino(attr->ino);
165 inode->i_mode = (inode->i_mode & S_IFMT) | (attr->mode & 07777);
166 set_nlink(inode, attr->nlink);
167 inode->i_uid = attr->uid;
168 inode->i_gid = attr->gid;
169 inode->i_blocks = attr->blocks;
170 inode->i_atime.tv_sec = attr->atime;
171 inode->i_atime.tv_nsec = attr->atimensec;
172 inode->i_mtime.tv_sec = attr->mtime;
173 inode->i_mtime.tv_nsec = attr->mtimensec;
174 inode->i_ctime.tv_sec = attr->ctime;
175 inode->i_ctime.tv_nsec = attr->ctimensec;
176
177 if (attr->blksize != 0)
178 inode->i_blkbits = ilog2(attr->blksize);
179 else
180 inode->i_blkbits = inode->i_sb->s_blocksize_bits;
181
182 /*
183 * Don't set the sticky bit in i_mode, unless we want the VFS
184 * to check permissions. This prevents failures due to the
185 * check in may_delete().
186 */
187 fi->orig_i_mode = inode->i_mode;
188 if (!(fc->flags & FUSE_DEFAULT_PERMISSIONS))
189 inode->i_mode &= ~S_ISVTX;
190
191 fi->orig_ino = attr->ino;
192}
193
194void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
195 u64 attr_valid, u64 attr_version)
196{
197 struct fuse_conn *fc = get_fuse_conn(inode);
198 struct fuse_inode *fi = get_fuse_inode(inode);
199 loff_t oldsize;
200
201 spin_lock(&fc->lock);
202 if (attr_version != 0 && fi->attr_version > attr_version) {
203 spin_unlock(&fc->lock);
204 return;
205 }
206
207 fuse_change_attributes_common(inode, attr, attr_valid);
208
209 oldsize = inode->i_size;
210 i_size_write(inode, attr->size);
211 spin_unlock(&fc->lock);
212
213 if (S_ISREG(inode->i_mode) && oldsize != attr->size) {
214 truncate_pagecache(inode, oldsize, attr->size);
215 invalidate_inode_pages2(inode->i_mapping);
216 }
217}
218
219static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
220{
221 inode->i_mode = attr->mode & S_IFMT;
222 inode->i_size = attr->size;
223 if (S_ISREG(inode->i_mode)) {
224 fuse_init_common(inode);
225 fuse_init_file_inode(inode);
226 } else if (S_ISDIR(inode->i_mode))
227 fuse_init_dir(inode);
228 else if (S_ISLNK(inode->i_mode))
229 fuse_init_symlink(inode);
230 else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
231 S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
232 fuse_init_common(inode);
233 init_special_inode(inode, inode->i_mode,
234 new_decode_dev(attr->rdev));
235 } else
236 BUG();
237}
238
239int fuse_inode_eq(struct inode *inode, void *_nodeidp)
240{
241 u64 nodeid = *(u64 *) _nodeidp;
242 if (get_node_id(inode) == nodeid)
243 return 1;
244 else
245 return 0;
246}
247
248static int fuse_inode_set(struct inode *inode, void *_nodeidp)
249{
250 u64 nodeid = *(u64 *) _nodeidp;
251 get_fuse_inode(inode)->nodeid = nodeid;
252 return 0;
253}
254
255struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
256 int generation, struct fuse_attr *attr,
257 u64 attr_valid, u64 attr_version)
258{
259 struct inode *inode;
260 struct fuse_inode *fi;
261 struct fuse_conn *fc = get_fuse_conn_super(sb);
262
263 retry:
264 inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid);
265 if (!inode)
266 return NULL;
267
268 if ((inode->i_state & I_NEW)) {
269 inode->i_flags |= S_NOATIME|S_NOCMTIME;
270 inode->i_generation = generation;
271 inode->i_data.backing_dev_info = &fc->bdi;
272 fuse_init_inode(inode, attr);
273 unlock_new_inode(inode);
274 } else if ((inode->i_mode ^ attr->mode) & S_IFMT) {
275 /* Inode has changed type, any I/O on the old should fail */
276 make_bad_inode(inode);
277 iput(inode);
278 goto retry;
279 }
280
281 fi = get_fuse_inode(inode);
282 spin_lock(&fc->lock);
283 fi->nlookup++;
284 spin_unlock(&fc->lock);
285 fuse_change_attributes(inode, attr, attr_valid, attr_version);
286
287 return inode;
288}
289
290int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid,
291 loff_t offset, loff_t len)
292{
293 struct inode *inode;
294 pgoff_t pg_start;
295 pgoff_t pg_end;
296
297 inode = ilookup5(sb, nodeid, fuse_inode_eq, &nodeid);
298 if (!inode)
299 return -ENOENT;
300
301 fuse_invalidate_attr(inode);
302 if (offset >= 0) {
303 pg_start = offset >> PAGE_CACHE_SHIFT;
304 if (len <= 0)
305 pg_end = -1;
306 else
307 pg_end = (offset + len - 1) >> PAGE_CACHE_SHIFT;
308 invalidate_inode_pages2_range(inode->i_mapping,
309 pg_start, pg_end);
310 }
311 iput(inode);
312 return 0;
313}
314
315static void fuse_umount_begin(struct super_block *sb)
316{
317 fuse_abort_conn(get_fuse_conn_super(sb));
318}
319
320static void fuse_send_destroy(struct fuse_conn *fc)
321{
322 struct fuse_req *req = fc->destroy_req;
323 if (req && fc->conn_init) {
324 fc->destroy_req = NULL;
325 req->in.h.opcode = FUSE_DESTROY;
326 req->force = 1;
327 fuse_request_send(fc, req);
328 fuse_put_request(fc, req);
329 }
330}
331
332static void fuse_bdi_destroy(struct fuse_conn *fc)
333{
334 if (fc->bdi_initialized)
335 bdi_destroy(&fc->bdi);
336}
337
338void fuse_conn_kill(struct fuse_conn *fc)
339{
340 spin_lock(&fc->lock);
341 fc->connected = 0;
342 fc->blocked = 0;
343 spin_unlock(&fc->lock);
344 /* Flush all readers on this fs */
345 kill_fasync(&fc->fasync, SIGIO, POLL_IN);
346 wake_up_all(&fc->waitq);
347 wake_up_all(&fc->blocked_waitq);
348 wake_up_all(&fc->reserved_req_waitq);
349 mutex_lock(&fuse_mutex);
350 list_del(&fc->entry);
351 fuse_ctl_remove_conn(fc);
352 mutex_unlock(&fuse_mutex);
353 fuse_bdi_destroy(fc);
354}
355EXPORT_SYMBOL_GPL(fuse_conn_kill);
356
357static void fuse_put_super(struct super_block *sb)
358{
359 struct fuse_conn *fc = get_fuse_conn_super(sb);
360
361 fuse_send_destroy(fc);
362 fuse_conn_kill(fc);
363 fuse_conn_put(fc);
364}
365
366static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
367{
368 stbuf->f_type = FUSE_SUPER_MAGIC;
369 stbuf->f_bsize = attr->bsize;
370 stbuf->f_frsize = attr->frsize;
371 stbuf->f_blocks = attr->blocks;
372 stbuf->f_bfree = attr->bfree;
373 stbuf->f_bavail = attr->bavail;
374 stbuf->f_files = attr->files;
375 stbuf->f_ffree = attr->ffree;
376 stbuf->f_namelen = attr->namelen;
377 /* fsid is left zero */
378}
379
380static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf)
381{
382 struct super_block *sb = dentry->d_sb;
383 struct fuse_conn *fc = get_fuse_conn_super(sb);
384 struct fuse_req *req;
385 struct fuse_statfs_out outarg;
386 int err;
387
388 if (!fuse_allow_task(fc, current)) {
389 buf->f_type = FUSE_SUPER_MAGIC;
390 return 0;
391 }
392
393 req = fuse_get_req(fc);
394 if (IS_ERR(req))
395 return PTR_ERR(req);
396
397 memset(&outarg, 0, sizeof(outarg));
398 req->in.numargs = 0;
399 req->in.h.opcode = FUSE_STATFS;
400 req->in.h.nodeid = get_node_id(dentry->d_inode);
401 req->out.numargs = 1;
402 req->out.args[0].size =
403 fc->minor < 4 ? FUSE_COMPAT_STATFS_SIZE : sizeof(outarg);
404 req->out.args[0].value = &outarg;
405 fuse_request_send(fc, req);
406 err = req->out.h.error;
407 if (!err)
408 convert_fuse_statfs(buf, &outarg.st);
409 fuse_put_request(fc, req);
410 return err;
411}
412
413enum {
414 OPT_FD,
415 OPT_ROOTMODE,
416 OPT_USER_ID,
417 OPT_GROUP_ID,
418 OPT_DEFAULT_PERMISSIONS,
419 OPT_ALLOW_OTHER,
420 OPT_MAX_READ,
421 OPT_BLKSIZE,
422 OPT_ERR
423};
424
425static const match_table_t tokens = {
426 {OPT_FD, "fd=%u"},
427 {OPT_ROOTMODE, "rootmode=%o"},
428 {OPT_USER_ID, "user_id=%u"},
429 {OPT_GROUP_ID, "group_id=%u"},
430 {OPT_DEFAULT_PERMISSIONS, "default_permissions"},
431 {OPT_ALLOW_OTHER, "allow_other"},
432 {OPT_MAX_READ, "max_read=%u"},
433 {OPT_BLKSIZE, "blksize=%u"},
434 {OPT_ERR, NULL}
435};
436
437static int parse_fuse_opt(char *opt, struct fuse_mount_data *d, int is_bdev)
438{
439 char *p;
440 memset(d, 0, sizeof(struct fuse_mount_data));
441 d->max_read = ~0;
442 d->blksize = FUSE_DEFAULT_BLKSIZE;
443
444 while ((p = strsep(&opt, ",")) != NULL) {
445 int token;
446 int value;
447 substring_t args[MAX_OPT_ARGS];
448 if (!*p)
449 continue;
450
451 token = match_token(p, tokens, args);
452 switch (token) {
453 case OPT_FD:
454 if (match_int(&args[0], &value))
455 return 0;
456 d->fd = value;
457 d->fd_present = 1;
458 break;
459
460 case OPT_ROOTMODE:
461 if (match_octal(&args[0], &value))
462 return 0;
463 if (!fuse_valid_type(value))
464 return 0;
465 d->rootmode = value;
466 d->rootmode_present = 1;
467 break;
468
469 case OPT_USER_ID:
470 if (match_int(&args[0], &value))
471 return 0;
472 d->user_id = value;
473 d->user_id_present = 1;
474 break;
475
476 case OPT_GROUP_ID:
477 if (match_int(&args[0], &value))
478 return 0;
479 d->group_id = value;
480 d->group_id_present = 1;
481 break;
482
483 case OPT_DEFAULT_PERMISSIONS:
484 d->flags |= FUSE_DEFAULT_PERMISSIONS;
485 break;
486
487 case OPT_ALLOW_OTHER:
488 d->flags |= FUSE_ALLOW_OTHER;
489 break;
490
491 case OPT_MAX_READ:
492 if (match_int(&args[0], &value))
493 return 0;
494 d->max_read = value;
495 break;
496
497 case OPT_BLKSIZE:
498 if (!is_bdev || match_int(&args[0], &value))
499 return 0;
500 d->blksize = value;
501 break;
502
503 default:
504 return 0;
505 }
506 }
507
508 if (!d->fd_present || !d->rootmode_present ||
509 !d->user_id_present || !d->group_id_present)
510 return 0;
511
512 return 1;
513}
514
515static int fuse_show_options(struct seq_file *m, struct dentry *root)
516{
517 struct super_block *sb = root->d_sb;
518 struct fuse_conn *fc = get_fuse_conn_super(sb);
519
520 seq_printf(m, ",user_id=%u", fc->user_id);
521 seq_printf(m, ",group_id=%u", fc->group_id);
522 if (fc->flags & FUSE_DEFAULT_PERMISSIONS)
523 seq_puts(m, ",default_permissions");
524 if (fc->flags & FUSE_ALLOW_OTHER)
525 seq_puts(m, ",allow_other");
526 if (fc->max_read != ~0)
527 seq_printf(m, ",max_read=%u", fc->max_read);
528 if (sb->s_bdev && sb->s_blocksize != FUSE_DEFAULT_BLKSIZE)
529 seq_printf(m, ",blksize=%lu", sb->s_blocksize);
530 return 0;
531}
532
533void fuse_conn_init(struct fuse_conn *fc)
534{
535 memset(fc, 0, sizeof(*fc));
536 spin_lock_init(&fc->lock);
537 mutex_init(&fc->inst_mutex);
538 init_rwsem(&fc->killsb);
539 atomic_set(&fc->count, 1);
540 init_waitqueue_head(&fc->waitq);
541 init_waitqueue_head(&fc->blocked_waitq);
542 init_waitqueue_head(&fc->reserved_req_waitq);
543 INIT_LIST_HEAD(&fc->pending);
544 INIT_LIST_HEAD(&fc->processing);
545 INIT_LIST_HEAD(&fc->io);
546 INIT_LIST_HEAD(&fc->interrupts);
547 INIT_LIST_HEAD(&fc->bg_queue);
548 INIT_LIST_HEAD(&fc->entry);
549 fc->forget_list_tail = &fc->forget_list_head;
550 atomic_set(&fc->num_waiting, 0);
551 fc->max_background = FUSE_DEFAULT_MAX_BACKGROUND;
552 fc->congestion_threshold = FUSE_DEFAULT_CONGESTION_THRESHOLD;
553 fc->khctr = 0;
554 fc->polled_files = RB_ROOT;
555 fc->reqctr = 0;
556 fc->blocked = 1;
557 fc->attr_version = 1;
558 get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key));
559}
560EXPORT_SYMBOL_GPL(fuse_conn_init);
561
562void fuse_conn_put(struct fuse_conn *fc)
563{
564 if (atomic_dec_and_test(&fc->count)) {
565 if (fc->destroy_req)
566 fuse_request_free(fc->destroy_req);
567 mutex_destroy(&fc->inst_mutex);
568 fc->release(fc);
569 }
570}
571EXPORT_SYMBOL_GPL(fuse_conn_put);
572
573struct fuse_conn *fuse_conn_get(struct fuse_conn *fc)
574{
575 atomic_inc(&fc->count);
576 return fc;
577}
578EXPORT_SYMBOL_GPL(fuse_conn_get);
579
580static struct inode *fuse_get_root_inode(struct super_block *sb, unsigned mode)
581{
582 struct fuse_attr attr;
583 memset(&attr, 0, sizeof(attr));
584
585 attr.mode = mode;
586 attr.ino = FUSE_ROOT_ID;
587 attr.nlink = 1;
588 return fuse_iget(sb, 1, 0, &attr, 0, 0);
589}
590
591struct fuse_inode_handle {
592 u64 nodeid;
593 u32 generation;
594};
595
596static struct dentry *fuse_get_dentry(struct super_block *sb,
597 struct fuse_inode_handle *handle)
598{
599 struct fuse_conn *fc = get_fuse_conn_super(sb);
600 struct inode *inode;
601 struct dentry *entry;
602 int err = -ESTALE;
603
604 if (handle->nodeid == 0)
605 goto out_err;
606
607 inode = ilookup5(sb, handle->nodeid, fuse_inode_eq, &handle->nodeid);
608 if (!inode) {
609 struct fuse_entry_out outarg;
610 struct qstr name;
611
612 if (!fc->export_support)
613 goto out_err;
614
615 name.len = 1;
616 name.name = ".";
617 err = fuse_lookup_name(sb, handle->nodeid, &name, &outarg,
618 &inode);
619 if (err && err != -ENOENT)
620 goto out_err;
621 if (err || !inode) {
622 err = -ESTALE;
623 goto out_err;
624 }
625 err = -EIO;
626 if (get_node_id(inode) != handle->nodeid)
627 goto out_iput;
628 }
629 err = -ESTALE;
630 if (inode->i_generation != handle->generation)
631 goto out_iput;
632
633 entry = d_obtain_alias(inode);
634 if (!IS_ERR(entry) && get_node_id(inode) != FUSE_ROOT_ID)
635 fuse_invalidate_entry_cache(entry);
636
637 return entry;
638
639 out_iput:
640 iput(inode);
641 out_err:
642 return ERR_PTR(err);
643}
644
645static int fuse_encode_fh(struct inode *inode, u32 *fh, int *max_len,
646 struct inode *parent)
647{
648 int len = parent ? 6 : 3;
649 u64 nodeid;
650 u32 generation;
651
652 if (*max_len < len) {
653 *max_len = len;
654 return 255;
655 }
656
657 nodeid = get_fuse_inode(inode)->nodeid;
658 generation = inode->i_generation;
659
660 fh[0] = (u32)(nodeid >> 32);
661 fh[1] = (u32)(nodeid & 0xffffffff);
662 fh[2] = generation;
663
664 if (parent) {
665 nodeid = get_fuse_inode(parent)->nodeid;
666 generation = parent->i_generation;
667
668 fh[3] = (u32)(nodeid >> 32);
669 fh[4] = (u32)(nodeid & 0xffffffff);
670 fh[5] = generation;
671 }
672
673 *max_len = len;
674 return parent ? 0x82 : 0x81;
675}
676
677static struct dentry *fuse_fh_to_dentry(struct super_block *sb,
678 struct fid *fid, int fh_len, int fh_type)
679{
680 struct fuse_inode_handle handle;
681
682 if ((fh_type != 0x81 && fh_type != 0x82) || fh_len < 3)
683 return NULL;
684
685 handle.nodeid = (u64) fid->raw[0] << 32;
686 handle.nodeid |= (u64) fid->raw[1];
687 handle.generation = fid->raw[2];
688 return fuse_get_dentry(sb, &handle);
689}
690
691static struct dentry *fuse_fh_to_parent(struct super_block *sb,
692 struct fid *fid, int fh_len, int fh_type)
693{
694 struct fuse_inode_handle parent;
695
696 if (fh_type != 0x82 || fh_len < 6)
697 return NULL;
698
699 parent.nodeid = (u64) fid->raw[3] << 32;
700 parent.nodeid |= (u64) fid->raw[4];
701 parent.generation = fid->raw[5];
702 return fuse_get_dentry(sb, &parent);
703}
704
705static struct dentry *fuse_get_parent(struct dentry *child)
706{
707 struct inode *child_inode = child->d_inode;
708 struct fuse_conn *fc = get_fuse_conn(child_inode);
709 struct inode *inode;
710 struct dentry *parent;
711 struct fuse_entry_out outarg;
712 struct qstr name;
713 int err;
714
715 if (!fc->export_support)
716 return ERR_PTR(-ESTALE);
717
718 name.len = 2;
719 name.name = "..";
720 err = fuse_lookup_name(child_inode->i_sb, get_node_id(child_inode),
721 &name, &outarg, &inode);
722 if (err) {
723 if (err == -ENOENT)
724 return ERR_PTR(-ESTALE);
725 return ERR_PTR(err);
726 }
727
728 parent = d_obtain_alias(inode);
729 if (!IS_ERR(parent) && get_node_id(inode) != FUSE_ROOT_ID)
730 fuse_invalidate_entry_cache(parent);
731
732 return parent;
733}
734
735static const struct export_operations fuse_export_operations = {
736 .fh_to_dentry = fuse_fh_to_dentry,
737 .fh_to_parent = fuse_fh_to_parent,
738 .encode_fh = fuse_encode_fh,
739 .get_parent = fuse_get_parent,
740};
741
742static const struct super_operations fuse_super_operations = {
743 .alloc_inode = fuse_alloc_inode,
744 .destroy_inode = fuse_destroy_inode,
745 .evict_inode = fuse_evict_inode,
746 .drop_inode = generic_delete_inode,
747 .remount_fs = fuse_remount_fs,
748 .put_super = fuse_put_super,
749 .umount_begin = fuse_umount_begin,
750 .statfs = fuse_statfs,
751 .show_options = fuse_show_options,
752};
753
754static void sanitize_global_limit(unsigned *limit)
755{
756 if (*limit == 0)
757 *limit = ((num_physpages << PAGE_SHIFT) >> 13) /
758 sizeof(struct fuse_req);
759
760 if (*limit >= 1 << 16)
761 *limit = (1 << 16) - 1;
762}
763
764static int set_global_limit(const char *val, struct kernel_param *kp)
765{
766 int rv;
767
768 rv = param_set_uint(val, kp);
769 if (rv)
770 return rv;
771
772 sanitize_global_limit((unsigned *)kp->arg);
773
774 return 0;
775}
776
777static void process_init_limits(struct fuse_conn *fc, struct fuse_init_out *arg)
778{
779 int cap_sys_admin = capable(CAP_SYS_ADMIN);
780
781 if (arg->minor < 13)
782 return;
783
784 sanitize_global_limit(&max_user_bgreq);
785 sanitize_global_limit(&max_user_congthresh);
786
787 if (arg->max_background) {
788 fc->max_background = arg->max_background;
789
790 if (!cap_sys_admin && fc->max_background > max_user_bgreq)
791 fc->max_background = max_user_bgreq;
792 }
793 if (arg->congestion_threshold) {
794 fc->congestion_threshold = arg->congestion_threshold;
795
796 if (!cap_sys_admin &&
797 fc->congestion_threshold > max_user_congthresh)
798 fc->congestion_threshold = max_user_congthresh;
799 }
800}
801
802static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
803{
804 struct fuse_init_out *arg = &req->misc.init_out;
805
806 if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION)
807 fc->conn_error = 1;
808 else {
809 unsigned long ra_pages;
810
811 process_init_limits(fc, arg);
812
813 if (arg->minor >= 6) {
814 ra_pages = arg->max_readahead / PAGE_CACHE_SIZE;
815 if (arg->flags & FUSE_ASYNC_READ)
816 fc->async_read = 1;
817 if (!(arg->flags & FUSE_POSIX_LOCKS))
818 fc->no_lock = 1;
819 if (arg->minor >= 17) {
820 if (!(arg->flags & FUSE_FLOCK_LOCKS))
821 fc->no_flock = 1;
822 } else {
823 if (!(arg->flags & FUSE_POSIX_LOCKS))
824 fc->no_flock = 1;
825 }
826 if (arg->flags & FUSE_ATOMIC_O_TRUNC)
827 fc->atomic_o_trunc = 1;
828 if (arg->minor >= 9) {
829 /* LOOKUP has dependency on proto version */
830 if (arg->flags & FUSE_EXPORT_SUPPORT)
831 fc->export_support = 1;
832 }
833 if (arg->flags & FUSE_BIG_WRITES)
834 fc->big_writes = 1;
835 if (arg->flags & FUSE_DONT_MASK)
836 fc->dont_mask = 1;
837 } else {
838 ra_pages = fc->max_read / PAGE_CACHE_SIZE;
839 fc->no_lock = 1;
840 fc->no_flock = 1;
841 }
842
843 fc->bdi.ra_pages = min(fc->bdi.ra_pages, ra_pages);
844 fc->minor = arg->minor;
845 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
846 fc->max_write = max_t(unsigned, 4096, fc->max_write);
847 fc->conn_init = 1;
848 }
849 fc->blocked = 0;
850 wake_up_all(&fc->blocked_waitq);
851}
852
853static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req)
854{
855 struct fuse_init_in *arg = &req->misc.init_in;
856
857 arg->major = FUSE_KERNEL_VERSION;
858 arg->minor = FUSE_KERNEL_MINOR_VERSION;
859 arg->max_readahead = fc->bdi.ra_pages * PAGE_CACHE_SIZE;
860 arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_ATOMIC_O_TRUNC |
861 FUSE_EXPORT_SUPPORT | FUSE_BIG_WRITES | FUSE_DONT_MASK |
862 FUSE_FLOCK_LOCKS;
863 req->in.h.opcode = FUSE_INIT;
864 req->in.numargs = 1;
865 req->in.args[0].size = sizeof(*arg);
866 req->in.args[0].value = arg;
867 req->out.numargs = 1;
868 /* Variable length argument used for backward compatibility
869 with interface version < 7.5. Rest of init_out is zeroed
870 by do_get_request(), so a short reply is not a problem */
871 req->out.argvar = 1;
872 req->out.args[0].size = sizeof(struct fuse_init_out);
873 req->out.args[0].value = &req->misc.init_out;
874 req->end = process_init_reply;
875 fuse_request_send_background(fc, req);
876}
877
878static void fuse_free_conn(struct fuse_conn *fc)
879{
880 kfree(fc);
881}
882
883static int fuse_bdi_init(struct fuse_conn *fc, struct super_block *sb)
884{
885 int err;
886
887 fc->bdi.name = "fuse";
888 fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
889 /* fuse does it's own writeback accounting */
890 fc->bdi.capabilities = BDI_CAP_NO_ACCT_WB;
891
892 err = bdi_init(&fc->bdi);
893 if (err)
894 return err;
895
896 fc->bdi_initialized = 1;
897
898 if (sb->s_bdev) {
899 err = bdi_register(&fc->bdi, NULL, "%u:%u-fuseblk",
900 MAJOR(fc->dev), MINOR(fc->dev));
901 } else {
902 err = bdi_register_dev(&fc->bdi, fc->dev);
903 }
904
905 if (err)
906 return err;
907
908 /*
909 * For a single fuse filesystem use max 1% of dirty +
910 * writeback threshold.
911 *
912 * This gives about 1M of write buffer for memory maps on a
913 * machine with 1G and 10% dirty_ratio, which should be more
914 * than enough.
915 *
916 * Privileged users can raise it by writing to
917 *
918 * /sys/class/bdi/<bdi>/max_ratio
919 */
920 bdi_set_max_ratio(&fc->bdi, 1);
921
922 return 0;
923}
924
925static int fuse_fill_super(struct super_block *sb, void *data, int silent)
926{
927 struct fuse_conn *fc;
928 struct inode *root;
929 struct fuse_mount_data d;
930 struct file *file;
931 struct dentry *root_dentry;
932 struct fuse_req *init_req;
933 int err;
934 int is_bdev = sb->s_bdev != NULL;
935
936 err = -EINVAL;
937 if (sb->s_flags & MS_MANDLOCK)
938 goto err;
939
940 sb->s_flags &= ~MS_NOSEC;
941
942 if (!parse_fuse_opt((char *) data, &d, is_bdev))
943 goto err;
944
945 if (is_bdev) {
946#ifdef CONFIG_BLOCK
947 err = -EINVAL;
948 if (!sb_set_blocksize(sb, d.blksize))
949 goto err;
950#endif
951 } else {
952 sb->s_blocksize = PAGE_CACHE_SIZE;
953 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
954 }
955 sb->s_magic = FUSE_SUPER_MAGIC;
956 sb->s_op = &fuse_super_operations;
957 sb->s_maxbytes = MAX_LFS_FILESIZE;
958 sb->s_time_gran = 1;
959 sb->s_export_op = &fuse_export_operations;
960
961 file = fget(d.fd);
962 err = -EINVAL;
963 if (!file)
964 goto err;
965
966 if (file->f_op != &fuse_dev_operations)
967 goto err_fput;
968
969 fc = kmalloc(sizeof(*fc), GFP_KERNEL);
970 err = -ENOMEM;
971 if (!fc)
972 goto err_fput;
973
974 fuse_conn_init(fc);
975
976 fc->dev = sb->s_dev;
977 fc->sb = sb;
978 err = fuse_bdi_init(fc, sb);
979 if (err)
980 goto err_put_conn;
981
982 sb->s_bdi = &fc->bdi;
983
984 /* Handle umasking inside the fuse code */
985 if (sb->s_flags & MS_POSIXACL)
986 fc->dont_mask = 1;
987 sb->s_flags |= MS_POSIXACL;
988
989 fc->release = fuse_free_conn;
990 fc->flags = d.flags;
991 fc->user_id = d.user_id;
992 fc->group_id = d.group_id;
993 fc->max_read = max_t(unsigned, 4096, d.max_read);
994
995 /* Used by get_root_inode() */
996 sb->s_fs_info = fc;
997
998 err = -ENOMEM;
999 root = fuse_get_root_inode(sb, d.rootmode);
1000 root_dentry = d_make_root(root);
1001 if (!root_dentry)
1002 goto err_put_conn;
1003 /* only now - we want root dentry with NULL ->d_op */
1004 sb->s_d_op = &fuse_dentry_operations;
1005
1006 init_req = fuse_request_alloc();
1007 if (!init_req)
1008 goto err_put_root;
1009
1010 if (is_bdev) {
1011 fc->destroy_req = fuse_request_alloc();
1012 if (!fc->destroy_req)
1013 goto err_free_init_req;
1014 }
1015
1016 mutex_lock(&fuse_mutex);
1017 err = -EINVAL;
1018 if (file->private_data)
1019 goto err_unlock;
1020
1021 err = fuse_ctl_add_conn(fc);
1022 if (err)
1023 goto err_unlock;
1024
1025 list_add_tail(&fc->entry, &fuse_conn_list);
1026 sb->s_root = root_dentry;
1027 fc->connected = 1;
1028 file->private_data = fuse_conn_get(fc);
1029 mutex_unlock(&fuse_mutex);
1030 /*
1031 * atomic_dec_and_test() in fput() provides the necessary
1032 * memory barrier for file->private_data to be visible on all
1033 * CPUs after this
1034 */
1035 fput(file);
1036
1037 fuse_send_init(fc, init_req);
1038
1039 return 0;
1040
1041 err_unlock:
1042 mutex_unlock(&fuse_mutex);
1043 err_free_init_req:
1044 fuse_request_free(init_req);
1045 err_put_root:
1046 dput(root_dentry);
1047 err_put_conn:
1048 fuse_bdi_destroy(fc);
1049 fuse_conn_put(fc);
1050 err_fput:
1051 fput(file);
1052 err:
1053 return err;
1054}
1055
1056static struct dentry *fuse_mount(struct file_system_type *fs_type,
1057 int flags, const char *dev_name,
1058 void *raw_data)
1059{
1060 return mount_nodev(fs_type, flags, raw_data, fuse_fill_super);
1061}
1062
1063static void fuse_kill_sb_anon(struct super_block *sb)
1064{
1065 struct fuse_conn *fc = get_fuse_conn_super(sb);
1066
1067 if (fc) {
1068 down_write(&fc->killsb);
1069 fc->sb = NULL;
1070 up_write(&fc->killsb);
1071 }
1072
1073 kill_anon_super(sb);
1074}
1075
1076static struct file_system_type fuse_fs_type = {
1077 .owner = THIS_MODULE,
1078 .name = "fuse",
1079 .fs_flags = FS_HAS_SUBTYPE,
1080 .mount = fuse_mount,
1081 .kill_sb = fuse_kill_sb_anon,
1082};
1083
1084#ifdef CONFIG_BLOCK
1085static struct dentry *fuse_mount_blk(struct file_system_type *fs_type,
1086 int flags, const char *dev_name,
1087 void *raw_data)
1088{
1089 return mount_bdev(fs_type, flags, dev_name, raw_data, fuse_fill_super);
1090}
1091
1092static void fuse_kill_sb_blk(struct super_block *sb)
1093{
1094 struct fuse_conn *fc = get_fuse_conn_super(sb);
1095
1096 if (fc) {
1097 down_write(&fc->killsb);
1098 fc->sb = NULL;
1099 up_write(&fc->killsb);
1100 }
1101
1102 kill_block_super(sb);
1103}
1104
1105static struct file_system_type fuseblk_fs_type = {
1106 .owner = THIS_MODULE,
1107 .name = "fuseblk",
1108 .mount = fuse_mount_blk,
1109 .kill_sb = fuse_kill_sb_blk,
1110 .fs_flags = FS_REQUIRES_DEV | FS_HAS_SUBTYPE,
1111};
1112
1113static inline int register_fuseblk(void)
1114{
1115 return register_filesystem(&fuseblk_fs_type);
1116}
1117
1118static inline void unregister_fuseblk(void)
1119{
1120 unregister_filesystem(&fuseblk_fs_type);
1121}
1122#else
1123static inline int register_fuseblk(void)
1124{
1125 return 0;
1126}
1127
1128static inline void unregister_fuseblk(void)
1129{
1130}
1131#endif
1132
1133static void fuse_inode_init_once(void *foo)
1134{
1135 struct inode *inode = foo;
1136
1137 inode_init_once(inode);
1138}
1139
1140static int __init fuse_fs_init(void)
1141{
1142 int err;
1143
1144 fuse_inode_cachep = kmem_cache_create("fuse_inode",
1145 sizeof(struct fuse_inode),
1146 0, SLAB_HWCACHE_ALIGN,
1147 fuse_inode_init_once);
1148 err = -ENOMEM;
1149 if (!fuse_inode_cachep)
1150 goto out;
1151
1152 err = register_fuseblk();
1153 if (err)
1154 goto out2;
1155
1156 err = register_filesystem(&fuse_fs_type);
1157 if (err)
1158 goto out3;
1159
1160 return 0;
1161
1162 out3:
1163 unregister_fuseblk();
1164 out2:
1165 kmem_cache_destroy(fuse_inode_cachep);
1166 out:
1167 return err;
1168}
1169
1170static void fuse_fs_cleanup(void)
1171{
1172 unregister_filesystem(&fuse_fs_type);
1173 unregister_fuseblk();
1174 kmem_cache_destroy(fuse_inode_cachep);
1175}
1176
1177static struct kobject *fuse_kobj;
1178static struct kobject *connections_kobj;
1179
1180static int fuse_sysfs_init(void)
1181{
1182 int err;
1183
1184 fuse_kobj = kobject_create_and_add("fuse", fs_kobj);
1185 if (!fuse_kobj) {
1186 err = -ENOMEM;
1187 goto out_err;
1188 }
1189
1190 connections_kobj = kobject_create_and_add("connections", fuse_kobj);
1191 if (!connections_kobj) {
1192 err = -ENOMEM;
1193 goto out_fuse_unregister;
1194 }
1195
1196 return 0;
1197
1198 out_fuse_unregister:
1199 kobject_put(fuse_kobj);
1200 out_err:
1201 return err;
1202}
1203
1204static void fuse_sysfs_cleanup(void)
1205{
1206 kobject_put(connections_kobj);
1207 kobject_put(fuse_kobj);
1208}
1209
1210static int __init fuse_init(void)
1211{
1212 int res;
1213
1214 printk(KERN_INFO "fuse init (API version %i.%i)\n",
1215 FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
1216
1217 INIT_LIST_HEAD(&fuse_conn_list);
1218 res = fuse_fs_init();
1219 if (res)
1220 goto err;
1221
1222 res = fuse_dev_init();
1223 if (res)
1224 goto err_fs_cleanup;
1225
1226 res = fuse_sysfs_init();
1227 if (res)
1228 goto err_dev_cleanup;
1229
1230 res = fuse_ctl_init();
1231 if (res)
1232 goto err_sysfs_cleanup;
1233
1234 sanitize_global_limit(&max_user_bgreq);
1235 sanitize_global_limit(&max_user_congthresh);
1236
1237 return 0;
1238
1239 err_sysfs_cleanup:
1240 fuse_sysfs_cleanup();
1241 err_dev_cleanup:
1242 fuse_dev_cleanup();
1243 err_fs_cleanup:
1244 fuse_fs_cleanup();
1245 err:
1246 return res;
1247}
1248
1249static void __exit fuse_exit(void)
1250{
1251 printk(KERN_DEBUG "fuse exit\n");
1252
1253 fuse_ctl_cleanup();
1254 fuse_sysfs_cleanup();
1255 fuse_fs_cleanup();
1256 fuse_dev_cleanup();
1257}
1258
1259module_init(fuse_init);
1260module_exit(fuse_exit);
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
24MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>");
25MODULE_DESCRIPTION("Filesystem in Userspace");
26MODULE_LICENSE("GPL");
27
28static struct kmem_cache *fuse_inode_cachep;
29struct list_head fuse_conn_list;
30DEFINE_MUTEX(fuse_mutex);
31
32static int set_global_limit(const char *val, struct kernel_param *kp);
33
34unsigned max_user_bgreq;
35module_param_call(max_user_bgreq, set_global_limit, param_get_uint,
36 &max_user_bgreq, 0644);
37__MODULE_PARM_TYPE(max_user_bgreq, "uint");
38MODULE_PARM_DESC(max_user_bgreq,
39 "Global limit for the maximum number of backgrounded requests an "
40 "unprivileged user can set");
41
42unsigned max_user_congthresh;
43module_param_call(max_user_congthresh, set_global_limit, param_get_uint,
44 &max_user_congthresh, 0644);
45__MODULE_PARM_TYPE(max_user_congthresh, "uint");
46MODULE_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
60struct fuse_mount_data {
61 int fd;
62 unsigned rootmode;
63 unsigned user_id;
64 unsigned 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
74struct fuse_forget_link *fuse_alloc_forget(void)
75{
76 return kzalloc(sizeof(struct fuse_forget_link), GFP_KERNEL);
77}
78
79static 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 INIT_LIST_HEAD(&fi->write_files);
95 INIT_LIST_HEAD(&fi->queued_writes);
96 INIT_LIST_HEAD(&fi->writepages);
97 init_waitqueue_head(&fi->page_waitq);
98 fi->forget = fuse_alloc_forget();
99 if (!fi->forget) {
100 kmem_cache_free(fuse_inode_cachep, inode);
101 return NULL;
102 }
103
104 return inode;
105}
106
107static void fuse_i_callback(struct rcu_head *head)
108{
109 struct inode *inode = container_of(head, struct inode, i_rcu);
110 INIT_LIST_HEAD(&inode->i_dentry);
111 kmem_cache_free(fuse_inode_cachep, inode);
112}
113
114static void fuse_destroy_inode(struct inode *inode)
115{
116 struct fuse_inode *fi = get_fuse_inode(inode);
117 BUG_ON(!list_empty(&fi->write_files));
118 BUG_ON(!list_empty(&fi->queued_writes));
119 kfree(fi->forget);
120 call_rcu(&inode->i_rcu, fuse_i_callback);
121}
122
123static void fuse_evict_inode(struct inode *inode)
124{
125 truncate_inode_pages(&inode->i_data, 0);
126 end_writeback(inode);
127 if (inode->i_sb->s_flags & MS_ACTIVE) {
128 struct fuse_conn *fc = get_fuse_conn(inode);
129 struct fuse_inode *fi = get_fuse_inode(inode);
130 fuse_queue_forget(fc, fi->forget, fi->nodeid, fi->nlookup);
131 fi->forget = NULL;
132 }
133}
134
135static int fuse_remount_fs(struct super_block *sb, int *flags, char *data)
136{
137 if (*flags & MS_MANDLOCK)
138 return -EINVAL;
139
140 return 0;
141}
142
143void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
144 u64 attr_valid)
145{
146 struct fuse_conn *fc = get_fuse_conn(inode);
147 struct fuse_inode *fi = get_fuse_inode(inode);
148
149 fi->attr_version = ++fc->attr_version;
150 fi->i_time = attr_valid;
151
152 inode->i_ino = attr->ino;
153 inode->i_mode = (inode->i_mode & S_IFMT) | (attr->mode & 07777);
154 inode->i_nlink = attr->nlink;
155 inode->i_uid = attr->uid;
156 inode->i_gid = attr->gid;
157 inode->i_blocks = attr->blocks;
158 inode->i_atime.tv_sec = attr->atime;
159 inode->i_atime.tv_nsec = attr->atimensec;
160 inode->i_mtime.tv_sec = attr->mtime;
161 inode->i_mtime.tv_nsec = attr->mtimensec;
162 inode->i_ctime.tv_sec = attr->ctime;
163 inode->i_ctime.tv_nsec = attr->ctimensec;
164
165 if (attr->blksize != 0)
166 inode->i_blkbits = ilog2(attr->blksize);
167 else
168 inode->i_blkbits = inode->i_sb->s_blocksize_bits;
169
170 /*
171 * Don't set the sticky bit in i_mode, unless we want the VFS
172 * to check permissions. This prevents failures due to the
173 * check in may_delete().
174 */
175 fi->orig_i_mode = inode->i_mode;
176 if (!(fc->flags & FUSE_DEFAULT_PERMISSIONS))
177 inode->i_mode &= ~S_ISVTX;
178}
179
180void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
181 u64 attr_valid, u64 attr_version)
182{
183 struct fuse_conn *fc = get_fuse_conn(inode);
184 struct fuse_inode *fi = get_fuse_inode(inode);
185 loff_t oldsize;
186
187 spin_lock(&fc->lock);
188 if (attr_version != 0 && fi->attr_version > attr_version) {
189 spin_unlock(&fc->lock);
190 return;
191 }
192
193 fuse_change_attributes_common(inode, attr, attr_valid);
194
195 oldsize = inode->i_size;
196 i_size_write(inode, attr->size);
197 spin_unlock(&fc->lock);
198
199 if (S_ISREG(inode->i_mode) && oldsize != attr->size) {
200 truncate_pagecache(inode, oldsize, attr->size);
201 invalidate_inode_pages2(inode->i_mapping);
202 }
203}
204
205static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
206{
207 inode->i_mode = attr->mode & S_IFMT;
208 inode->i_size = attr->size;
209 if (S_ISREG(inode->i_mode)) {
210 fuse_init_common(inode);
211 fuse_init_file_inode(inode);
212 } else if (S_ISDIR(inode->i_mode))
213 fuse_init_dir(inode);
214 else if (S_ISLNK(inode->i_mode))
215 fuse_init_symlink(inode);
216 else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
217 S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
218 fuse_init_common(inode);
219 init_special_inode(inode, inode->i_mode,
220 new_decode_dev(attr->rdev));
221 } else
222 BUG();
223}
224
225int fuse_inode_eq(struct inode *inode, void *_nodeidp)
226{
227 u64 nodeid = *(u64 *) _nodeidp;
228 if (get_node_id(inode) == nodeid)
229 return 1;
230 else
231 return 0;
232}
233
234static int fuse_inode_set(struct inode *inode, void *_nodeidp)
235{
236 u64 nodeid = *(u64 *) _nodeidp;
237 get_fuse_inode(inode)->nodeid = nodeid;
238 return 0;
239}
240
241struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
242 int generation, struct fuse_attr *attr,
243 u64 attr_valid, u64 attr_version)
244{
245 struct inode *inode;
246 struct fuse_inode *fi;
247 struct fuse_conn *fc = get_fuse_conn_super(sb);
248
249 retry:
250 inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid);
251 if (!inode)
252 return NULL;
253
254 if ((inode->i_state & I_NEW)) {
255 inode->i_flags |= S_NOATIME|S_NOCMTIME;
256 inode->i_generation = generation;
257 inode->i_data.backing_dev_info = &fc->bdi;
258 fuse_init_inode(inode, attr);
259 unlock_new_inode(inode);
260 } else if ((inode->i_mode ^ attr->mode) & S_IFMT) {
261 /* Inode has changed type, any I/O on the old should fail */
262 make_bad_inode(inode);
263 iput(inode);
264 goto retry;
265 }
266
267 fi = get_fuse_inode(inode);
268 spin_lock(&fc->lock);
269 fi->nlookup++;
270 spin_unlock(&fc->lock);
271 fuse_change_attributes(inode, attr, attr_valid, attr_version);
272
273 return inode;
274}
275
276int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid,
277 loff_t offset, loff_t len)
278{
279 struct inode *inode;
280 pgoff_t pg_start;
281 pgoff_t pg_end;
282
283 inode = ilookup5(sb, nodeid, fuse_inode_eq, &nodeid);
284 if (!inode)
285 return -ENOENT;
286
287 fuse_invalidate_attr(inode);
288 if (offset >= 0) {
289 pg_start = offset >> PAGE_CACHE_SHIFT;
290 if (len <= 0)
291 pg_end = -1;
292 else
293 pg_end = (offset + len - 1) >> PAGE_CACHE_SHIFT;
294 invalidate_inode_pages2_range(inode->i_mapping,
295 pg_start, pg_end);
296 }
297 iput(inode);
298 return 0;
299}
300
301static void fuse_umount_begin(struct super_block *sb)
302{
303 fuse_abort_conn(get_fuse_conn_super(sb));
304}
305
306static void fuse_send_destroy(struct fuse_conn *fc)
307{
308 struct fuse_req *req = fc->destroy_req;
309 if (req && fc->conn_init) {
310 fc->destroy_req = NULL;
311 req->in.h.opcode = FUSE_DESTROY;
312 req->force = 1;
313 fuse_request_send(fc, req);
314 fuse_put_request(fc, req);
315 }
316}
317
318static void fuse_bdi_destroy(struct fuse_conn *fc)
319{
320 if (fc->bdi_initialized)
321 bdi_destroy(&fc->bdi);
322}
323
324void fuse_conn_kill(struct fuse_conn *fc)
325{
326 spin_lock(&fc->lock);
327 fc->connected = 0;
328 fc->blocked = 0;
329 spin_unlock(&fc->lock);
330 /* Flush all readers on this fs */
331 kill_fasync(&fc->fasync, SIGIO, POLL_IN);
332 wake_up_all(&fc->waitq);
333 wake_up_all(&fc->blocked_waitq);
334 wake_up_all(&fc->reserved_req_waitq);
335 mutex_lock(&fuse_mutex);
336 list_del(&fc->entry);
337 fuse_ctl_remove_conn(fc);
338 mutex_unlock(&fuse_mutex);
339 fuse_bdi_destroy(fc);
340}
341EXPORT_SYMBOL_GPL(fuse_conn_kill);
342
343static void fuse_put_super(struct super_block *sb)
344{
345 struct fuse_conn *fc = get_fuse_conn_super(sb);
346
347 fuse_send_destroy(fc);
348 fuse_conn_kill(fc);
349 fuse_conn_put(fc);
350}
351
352static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
353{
354 stbuf->f_type = FUSE_SUPER_MAGIC;
355 stbuf->f_bsize = attr->bsize;
356 stbuf->f_frsize = attr->frsize;
357 stbuf->f_blocks = attr->blocks;
358 stbuf->f_bfree = attr->bfree;
359 stbuf->f_bavail = attr->bavail;
360 stbuf->f_files = attr->files;
361 stbuf->f_ffree = attr->ffree;
362 stbuf->f_namelen = attr->namelen;
363 /* fsid is left zero */
364}
365
366static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf)
367{
368 struct super_block *sb = dentry->d_sb;
369 struct fuse_conn *fc = get_fuse_conn_super(sb);
370 struct fuse_req *req;
371 struct fuse_statfs_out outarg;
372 int err;
373
374 if (!fuse_allow_task(fc, current)) {
375 buf->f_type = FUSE_SUPER_MAGIC;
376 return 0;
377 }
378
379 req = fuse_get_req(fc);
380 if (IS_ERR(req))
381 return PTR_ERR(req);
382
383 memset(&outarg, 0, sizeof(outarg));
384 req->in.numargs = 0;
385 req->in.h.opcode = FUSE_STATFS;
386 req->in.h.nodeid = get_node_id(dentry->d_inode);
387 req->out.numargs = 1;
388 req->out.args[0].size =
389 fc->minor < 4 ? FUSE_COMPAT_STATFS_SIZE : sizeof(outarg);
390 req->out.args[0].value = &outarg;
391 fuse_request_send(fc, req);
392 err = req->out.h.error;
393 if (!err)
394 convert_fuse_statfs(buf, &outarg.st);
395 fuse_put_request(fc, req);
396 return err;
397}
398
399enum {
400 OPT_FD,
401 OPT_ROOTMODE,
402 OPT_USER_ID,
403 OPT_GROUP_ID,
404 OPT_DEFAULT_PERMISSIONS,
405 OPT_ALLOW_OTHER,
406 OPT_MAX_READ,
407 OPT_BLKSIZE,
408 OPT_ERR
409};
410
411static const match_table_t tokens = {
412 {OPT_FD, "fd=%u"},
413 {OPT_ROOTMODE, "rootmode=%o"},
414 {OPT_USER_ID, "user_id=%u"},
415 {OPT_GROUP_ID, "group_id=%u"},
416 {OPT_DEFAULT_PERMISSIONS, "default_permissions"},
417 {OPT_ALLOW_OTHER, "allow_other"},
418 {OPT_MAX_READ, "max_read=%u"},
419 {OPT_BLKSIZE, "blksize=%u"},
420 {OPT_ERR, NULL}
421};
422
423static int parse_fuse_opt(char *opt, struct fuse_mount_data *d, int is_bdev)
424{
425 char *p;
426 memset(d, 0, sizeof(struct fuse_mount_data));
427 d->max_read = ~0;
428 d->blksize = FUSE_DEFAULT_BLKSIZE;
429
430 while ((p = strsep(&opt, ",")) != NULL) {
431 int token;
432 int value;
433 substring_t args[MAX_OPT_ARGS];
434 if (!*p)
435 continue;
436
437 token = match_token(p, tokens, args);
438 switch (token) {
439 case OPT_FD:
440 if (match_int(&args[0], &value))
441 return 0;
442 d->fd = value;
443 d->fd_present = 1;
444 break;
445
446 case OPT_ROOTMODE:
447 if (match_octal(&args[0], &value))
448 return 0;
449 if (!fuse_valid_type(value))
450 return 0;
451 d->rootmode = value;
452 d->rootmode_present = 1;
453 break;
454
455 case OPT_USER_ID:
456 if (match_int(&args[0], &value))
457 return 0;
458 d->user_id = value;
459 d->user_id_present = 1;
460 break;
461
462 case OPT_GROUP_ID:
463 if (match_int(&args[0], &value))
464 return 0;
465 d->group_id = value;
466 d->group_id_present = 1;
467 break;
468
469 case OPT_DEFAULT_PERMISSIONS:
470 d->flags |= FUSE_DEFAULT_PERMISSIONS;
471 break;
472
473 case OPT_ALLOW_OTHER:
474 d->flags |= FUSE_ALLOW_OTHER;
475 break;
476
477 case OPT_MAX_READ:
478 if (match_int(&args[0], &value))
479 return 0;
480 d->max_read = value;
481 break;
482
483 case OPT_BLKSIZE:
484 if (!is_bdev || match_int(&args[0], &value))
485 return 0;
486 d->blksize = value;
487 break;
488
489 default:
490 return 0;
491 }
492 }
493
494 if (!d->fd_present || !d->rootmode_present ||
495 !d->user_id_present || !d->group_id_present)
496 return 0;
497
498 return 1;
499}
500
501static int fuse_show_options(struct seq_file *m, struct vfsmount *mnt)
502{
503 struct fuse_conn *fc = get_fuse_conn_super(mnt->mnt_sb);
504
505 seq_printf(m, ",user_id=%u", fc->user_id);
506 seq_printf(m, ",group_id=%u", fc->group_id);
507 if (fc->flags & FUSE_DEFAULT_PERMISSIONS)
508 seq_puts(m, ",default_permissions");
509 if (fc->flags & FUSE_ALLOW_OTHER)
510 seq_puts(m, ",allow_other");
511 if (fc->max_read != ~0)
512 seq_printf(m, ",max_read=%u", fc->max_read);
513 if (mnt->mnt_sb->s_bdev &&
514 mnt->mnt_sb->s_blocksize != FUSE_DEFAULT_BLKSIZE)
515 seq_printf(m, ",blksize=%lu", mnt->mnt_sb->s_blocksize);
516 return 0;
517}
518
519void fuse_conn_init(struct fuse_conn *fc)
520{
521 memset(fc, 0, sizeof(*fc));
522 spin_lock_init(&fc->lock);
523 mutex_init(&fc->inst_mutex);
524 init_rwsem(&fc->killsb);
525 atomic_set(&fc->count, 1);
526 init_waitqueue_head(&fc->waitq);
527 init_waitqueue_head(&fc->blocked_waitq);
528 init_waitqueue_head(&fc->reserved_req_waitq);
529 INIT_LIST_HEAD(&fc->pending);
530 INIT_LIST_HEAD(&fc->processing);
531 INIT_LIST_HEAD(&fc->io);
532 INIT_LIST_HEAD(&fc->interrupts);
533 INIT_LIST_HEAD(&fc->bg_queue);
534 INIT_LIST_HEAD(&fc->entry);
535 fc->forget_list_tail = &fc->forget_list_head;
536 atomic_set(&fc->num_waiting, 0);
537 fc->max_background = FUSE_DEFAULT_MAX_BACKGROUND;
538 fc->congestion_threshold = FUSE_DEFAULT_CONGESTION_THRESHOLD;
539 fc->khctr = 0;
540 fc->polled_files = RB_ROOT;
541 fc->reqctr = 0;
542 fc->blocked = 1;
543 fc->attr_version = 1;
544 get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key));
545}
546EXPORT_SYMBOL_GPL(fuse_conn_init);
547
548void fuse_conn_put(struct fuse_conn *fc)
549{
550 if (atomic_dec_and_test(&fc->count)) {
551 if (fc->destroy_req)
552 fuse_request_free(fc->destroy_req);
553 mutex_destroy(&fc->inst_mutex);
554 fc->release(fc);
555 }
556}
557EXPORT_SYMBOL_GPL(fuse_conn_put);
558
559struct fuse_conn *fuse_conn_get(struct fuse_conn *fc)
560{
561 atomic_inc(&fc->count);
562 return fc;
563}
564EXPORT_SYMBOL_GPL(fuse_conn_get);
565
566static struct inode *fuse_get_root_inode(struct super_block *sb, unsigned mode)
567{
568 struct fuse_attr attr;
569 memset(&attr, 0, sizeof(attr));
570
571 attr.mode = mode;
572 attr.ino = FUSE_ROOT_ID;
573 attr.nlink = 1;
574 return fuse_iget(sb, 1, 0, &attr, 0, 0);
575}
576
577struct fuse_inode_handle {
578 u64 nodeid;
579 u32 generation;
580};
581
582static struct dentry *fuse_get_dentry(struct super_block *sb,
583 struct fuse_inode_handle *handle)
584{
585 struct fuse_conn *fc = get_fuse_conn_super(sb);
586 struct inode *inode;
587 struct dentry *entry;
588 int err = -ESTALE;
589
590 if (handle->nodeid == 0)
591 goto out_err;
592
593 inode = ilookup5(sb, handle->nodeid, fuse_inode_eq, &handle->nodeid);
594 if (!inode) {
595 struct fuse_entry_out outarg;
596 struct qstr name;
597
598 if (!fc->export_support)
599 goto out_err;
600
601 name.len = 1;
602 name.name = ".";
603 err = fuse_lookup_name(sb, handle->nodeid, &name, &outarg,
604 &inode);
605 if (err && err != -ENOENT)
606 goto out_err;
607 if (err || !inode) {
608 err = -ESTALE;
609 goto out_err;
610 }
611 err = -EIO;
612 if (get_node_id(inode) != handle->nodeid)
613 goto out_iput;
614 }
615 err = -ESTALE;
616 if (inode->i_generation != handle->generation)
617 goto out_iput;
618
619 entry = d_obtain_alias(inode);
620 if (!IS_ERR(entry) && get_node_id(inode) != FUSE_ROOT_ID)
621 fuse_invalidate_entry_cache(entry);
622
623 return entry;
624
625 out_iput:
626 iput(inode);
627 out_err:
628 return ERR_PTR(err);
629}
630
631static int fuse_encode_fh(struct dentry *dentry, u32 *fh, int *max_len,
632 int connectable)
633{
634 struct inode *inode = dentry->d_inode;
635 bool encode_parent = connectable && !S_ISDIR(inode->i_mode);
636 int len = encode_parent ? 6 : 3;
637 u64 nodeid;
638 u32 generation;
639
640 if (*max_len < len) {
641 *max_len = len;
642 return 255;
643 }
644
645 nodeid = get_fuse_inode(inode)->nodeid;
646 generation = inode->i_generation;
647
648 fh[0] = (u32)(nodeid >> 32);
649 fh[1] = (u32)(nodeid & 0xffffffff);
650 fh[2] = generation;
651
652 if (encode_parent) {
653 struct inode *parent;
654
655 spin_lock(&dentry->d_lock);
656 parent = dentry->d_parent->d_inode;
657 nodeid = get_fuse_inode(parent)->nodeid;
658 generation = parent->i_generation;
659 spin_unlock(&dentry->d_lock);
660
661 fh[3] = (u32)(nodeid >> 32);
662 fh[4] = (u32)(nodeid & 0xffffffff);
663 fh[5] = generation;
664 }
665
666 *max_len = len;
667 return encode_parent ? 0x82 : 0x81;
668}
669
670static struct dentry *fuse_fh_to_dentry(struct super_block *sb,
671 struct fid *fid, int fh_len, int fh_type)
672{
673 struct fuse_inode_handle handle;
674
675 if ((fh_type != 0x81 && fh_type != 0x82) || fh_len < 3)
676 return NULL;
677
678 handle.nodeid = (u64) fid->raw[0] << 32;
679 handle.nodeid |= (u64) fid->raw[1];
680 handle.generation = fid->raw[2];
681 return fuse_get_dentry(sb, &handle);
682}
683
684static struct dentry *fuse_fh_to_parent(struct super_block *sb,
685 struct fid *fid, int fh_len, int fh_type)
686{
687 struct fuse_inode_handle parent;
688
689 if (fh_type != 0x82 || fh_len < 6)
690 return NULL;
691
692 parent.nodeid = (u64) fid->raw[3] << 32;
693 parent.nodeid |= (u64) fid->raw[4];
694 parent.generation = fid->raw[5];
695 return fuse_get_dentry(sb, &parent);
696}
697
698static struct dentry *fuse_get_parent(struct dentry *child)
699{
700 struct inode *child_inode = child->d_inode;
701 struct fuse_conn *fc = get_fuse_conn(child_inode);
702 struct inode *inode;
703 struct dentry *parent;
704 struct fuse_entry_out outarg;
705 struct qstr name;
706 int err;
707
708 if (!fc->export_support)
709 return ERR_PTR(-ESTALE);
710
711 name.len = 2;
712 name.name = "..";
713 err = fuse_lookup_name(child_inode->i_sb, get_node_id(child_inode),
714 &name, &outarg, &inode);
715 if (err) {
716 if (err == -ENOENT)
717 return ERR_PTR(-ESTALE);
718 return ERR_PTR(err);
719 }
720
721 parent = d_obtain_alias(inode);
722 if (!IS_ERR(parent) && get_node_id(inode) != FUSE_ROOT_ID)
723 fuse_invalidate_entry_cache(parent);
724
725 return parent;
726}
727
728static const struct export_operations fuse_export_operations = {
729 .fh_to_dentry = fuse_fh_to_dentry,
730 .fh_to_parent = fuse_fh_to_parent,
731 .encode_fh = fuse_encode_fh,
732 .get_parent = fuse_get_parent,
733};
734
735static const struct super_operations fuse_super_operations = {
736 .alloc_inode = fuse_alloc_inode,
737 .destroy_inode = fuse_destroy_inode,
738 .evict_inode = fuse_evict_inode,
739 .drop_inode = generic_delete_inode,
740 .remount_fs = fuse_remount_fs,
741 .put_super = fuse_put_super,
742 .umount_begin = fuse_umount_begin,
743 .statfs = fuse_statfs,
744 .show_options = fuse_show_options,
745};
746
747static void sanitize_global_limit(unsigned *limit)
748{
749 if (*limit == 0)
750 *limit = ((num_physpages << PAGE_SHIFT) >> 13) /
751 sizeof(struct fuse_req);
752
753 if (*limit >= 1 << 16)
754 *limit = (1 << 16) - 1;
755}
756
757static int set_global_limit(const char *val, struct kernel_param *kp)
758{
759 int rv;
760
761 rv = param_set_uint(val, kp);
762 if (rv)
763 return rv;
764
765 sanitize_global_limit((unsigned *)kp->arg);
766
767 return 0;
768}
769
770static void process_init_limits(struct fuse_conn *fc, struct fuse_init_out *arg)
771{
772 int cap_sys_admin = capable(CAP_SYS_ADMIN);
773
774 if (arg->minor < 13)
775 return;
776
777 sanitize_global_limit(&max_user_bgreq);
778 sanitize_global_limit(&max_user_congthresh);
779
780 if (arg->max_background) {
781 fc->max_background = arg->max_background;
782
783 if (!cap_sys_admin && fc->max_background > max_user_bgreq)
784 fc->max_background = max_user_bgreq;
785 }
786 if (arg->congestion_threshold) {
787 fc->congestion_threshold = arg->congestion_threshold;
788
789 if (!cap_sys_admin &&
790 fc->congestion_threshold > max_user_congthresh)
791 fc->congestion_threshold = max_user_congthresh;
792 }
793}
794
795static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
796{
797 struct fuse_init_out *arg = &req->misc.init_out;
798
799 if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION)
800 fc->conn_error = 1;
801 else {
802 unsigned long ra_pages;
803
804 process_init_limits(fc, arg);
805
806 if (arg->minor >= 6) {
807 ra_pages = arg->max_readahead / PAGE_CACHE_SIZE;
808 if (arg->flags & FUSE_ASYNC_READ)
809 fc->async_read = 1;
810 if (!(arg->flags & FUSE_POSIX_LOCKS))
811 fc->no_lock = 1;
812 if (arg->minor >= 17) {
813 if (!(arg->flags & FUSE_FLOCK_LOCKS))
814 fc->no_flock = 1;
815 } else {
816 if (!(arg->flags & FUSE_POSIX_LOCKS))
817 fc->no_flock = 1;
818 }
819 if (arg->flags & FUSE_ATOMIC_O_TRUNC)
820 fc->atomic_o_trunc = 1;
821 if (arg->minor >= 9) {
822 /* LOOKUP has dependency on proto version */
823 if (arg->flags & FUSE_EXPORT_SUPPORT)
824 fc->export_support = 1;
825 }
826 if (arg->flags & FUSE_BIG_WRITES)
827 fc->big_writes = 1;
828 if (arg->flags & FUSE_DONT_MASK)
829 fc->dont_mask = 1;
830 } else {
831 ra_pages = fc->max_read / PAGE_CACHE_SIZE;
832 fc->no_lock = 1;
833 fc->no_flock = 1;
834 }
835
836 fc->bdi.ra_pages = min(fc->bdi.ra_pages, ra_pages);
837 fc->minor = arg->minor;
838 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
839 fc->max_write = max_t(unsigned, 4096, fc->max_write);
840 fc->conn_init = 1;
841 }
842 fc->blocked = 0;
843 wake_up_all(&fc->blocked_waitq);
844}
845
846static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req)
847{
848 struct fuse_init_in *arg = &req->misc.init_in;
849
850 arg->major = FUSE_KERNEL_VERSION;
851 arg->minor = FUSE_KERNEL_MINOR_VERSION;
852 arg->max_readahead = fc->bdi.ra_pages * PAGE_CACHE_SIZE;
853 arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_ATOMIC_O_TRUNC |
854 FUSE_EXPORT_SUPPORT | FUSE_BIG_WRITES | FUSE_DONT_MASK |
855 FUSE_FLOCK_LOCKS;
856 req->in.h.opcode = FUSE_INIT;
857 req->in.numargs = 1;
858 req->in.args[0].size = sizeof(*arg);
859 req->in.args[0].value = arg;
860 req->out.numargs = 1;
861 /* Variable length argument used for backward compatibility
862 with interface version < 7.5. Rest of init_out is zeroed
863 by do_get_request(), so a short reply is not a problem */
864 req->out.argvar = 1;
865 req->out.args[0].size = sizeof(struct fuse_init_out);
866 req->out.args[0].value = &req->misc.init_out;
867 req->end = process_init_reply;
868 fuse_request_send_background(fc, req);
869}
870
871static void fuse_free_conn(struct fuse_conn *fc)
872{
873 kfree(fc);
874}
875
876static int fuse_bdi_init(struct fuse_conn *fc, struct super_block *sb)
877{
878 int err;
879
880 fc->bdi.name = "fuse";
881 fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
882 /* fuse does it's own writeback accounting */
883 fc->bdi.capabilities = BDI_CAP_NO_ACCT_WB;
884
885 err = bdi_init(&fc->bdi);
886 if (err)
887 return err;
888
889 fc->bdi_initialized = 1;
890
891 if (sb->s_bdev) {
892 err = bdi_register(&fc->bdi, NULL, "%u:%u-fuseblk",
893 MAJOR(fc->dev), MINOR(fc->dev));
894 } else {
895 err = bdi_register_dev(&fc->bdi, fc->dev);
896 }
897
898 if (err)
899 return err;
900
901 /*
902 * For a single fuse filesystem use max 1% of dirty +
903 * writeback threshold.
904 *
905 * This gives about 1M of write buffer for memory maps on a
906 * machine with 1G and 10% dirty_ratio, which should be more
907 * than enough.
908 *
909 * Privileged users can raise it by writing to
910 *
911 * /sys/class/bdi/<bdi>/max_ratio
912 */
913 bdi_set_max_ratio(&fc->bdi, 1);
914
915 return 0;
916}
917
918static int fuse_fill_super(struct super_block *sb, void *data, int silent)
919{
920 struct fuse_conn *fc;
921 struct inode *root;
922 struct fuse_mount_data d;
923 struct file *file;
924 struct dentry *root_dentry;
925 struct fuse_req *init_req;
926 int err;
927 int is_bdev = sb->s_bdev != NULL;
928
929 err = -EINVAL;
930 if (sb->s_flags & MS_MANDLOCK)
931 goto err;
932
933 sb->s_flags &= ~MS_NOSEC;
934
935 if (!parse_fuse_opt((char *) data, &d, is_bdev))
936 goto err;
937
938 if (is_bdev) {
939#ifdef CONFIG_BLOCK
940 err = -EINVAL;
941 if (!sb_set_blocksize(sb, d.blksize))
942 goto err;
943#endif
944 } else {
945 sb->s_blocksize = PAGE_CACHE_SIZE;
946 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
947 }
948 sb->s_magic = FUSE_SUPER_MAGIC;
949 sb->s_op = &fuse_super_operations;
950 sb->s_maxbytes = MAX_LFS_FILESIZE;
951 sb->s_export_op = &fuse_export_operations;
952
953 file = fget(d.fd);
954 err = -EINVAL;
955 if (!file)
956 goto err;
957
958 if (file->f_op != &fuse_dev_operations)
959 goto err_fput;
960
961 fc = kmalloc(sizeof(*fc), GFP_KERNEL);
962 err = -ENOMEM;
963 if (!fc)
964 goto err_fput;
965
966 fuse_conn_init(fc);
967
968 fc->dev = sb->s_dev;
969 fc->sb = sb;
970 err = fuse_bdi_init(fc, sb);
971 if (err)
972 goto err_put_conn;
973
974 sb->s_bdi = &fc->bdi;
975
976 /* Handle umasking inside the fuse code */
977 if (sb->s_flags & MS_POSIXACL)
978 fc->dont_mask = 1;
979 sb->s_flags |= MS_POSIXACL;
980
981 fc->release = fuse_free_conn;
982 fc->flags = d.flags;
983 fc->user_id = d.user_id;
984 fc->group_id = d.group_id;
985 fc->max_read = max_t(unsigned, 4096, d.max_read);
986
987 /* Used by get_root_inode() */
988 sb->s_fs_info = fc;
989
990 err = -ENOMEM;
991 root = fuse_get_root_inode(sb, d.rootmode);
992 if (!root)
993 goto err_put_conn;
994
995 root_dentry = d_alloc_root(root);
996 if (!root_dentry) {
997 iput(root);
998 goto err_put_conn;
999 }
1000 /* only now - we want root dentry with NULL ->d_op */
1001 sb->s_d_op = &fuse_dentry_operations;
1002
1003 init_req = fuse_request_alloc();
1004 if (!init_req)
1005 goto err_put_root;
1006
1007 if (is_bdev) {
1008 fc->destroy_req = fuse_request_alloc();
1009 if (!fc->destroy_req)
1010 goto err_free_init_req;
1011 }
1012
1013 mutex_lock(&fuse_mutex);
1014 err = -EINVAL;
1015 if (file->private_data)
1016 goto err_unlock;
1017
1018 err = fuse_ctl_add_conn(fc);
1019 if (err)
1020 goto err_unlock;
1021
1022 list_add_tail(&fc->entry, &fuse_conn_list);
1023 sb->s_root = root_dentry;
1024 fc->connected = 1;
1025 file->private_data = fuse_conn_get(fc);
1026 mutex_unlock(&fuse_mutex);
1027 /*
1028 * atomic_dec_and_test() in fput() provides the necessary
1029 * memory barrier for file->private_data to be visible on all
1030 * CPUs after this
1031 */
1032 fput(file);
1033
1034 fuse_send_init(fc, init_req);
1035
1036 return 0;
1037
1038 err_unlock:
1039 mutex_unlock(&fuse_mutex);
1040 err_free_init_req:
1041 fuse_request_free(init_req);
1042 err_put_root:
1043 dput(root_dentry);
1044 err_put_conn:
1045 fuse_bdi_destroy(fc);
1046 fuse_conn_put(fc);
1047 err_fput:
1048 fput(file);
1049 err:
1050 return err;
1051}
1052
1053static struct dentry *fuse_mount(struct file_system_type *fs_type,
1054 int flags, const char *dev_name,
1055 void *raw_data)
1056{
1057 return mount_nodev(fs_type, flags, raw_data, fuse_fill_super);
1058}
1059
1060static void fuse_kill_sb_anon(struct super_block *sb)
1061{
1062 struct fuse_conn *fc = get_fuse_conn_super(sb);
1063
1064 if (fc) {
1065 down_write(&fc->killsb);
1066 fc->sb = NULL;
1067 up_write(&fc->killsb);
1068 }
1069
1070 kill_anon_super(sb);
1071}
1072
1073static struct file_system_type fuse_fs_type = {
1074 .owner = THIS_MODULE,
1075 .name = "fuse",
1076 .fs_flags = FS_HAS_SUBTYPE,
1077 .mount = fuse_mount,
1078 .kill_sb = fuse_kill_sb_anon,
1079};
1080
1081#ifdef CONFIG_BLOCK
1082static struct dentry *fuse_mount_blk(struct file_system_type *fs_type,
1083 int flags, const char *dev_name,
1084 void *raw_data)
1085{
1086 return mount_bdev(fs_type, flags, dev_name, raw_data, fuse_fill_super);
1087}
1088
1089static void fuse_kill_sb_blk(struct super_block *sb)
1090{
1091 struct fuse_conn *fc = get_fuse_conn_super(sb);
1092
1093 if (fc) {
1094 down_write(&fc->killsb);
1095 fc->sb = NULL;
1096 up_write(&fc->killsb);
1097 }
1098
1099 kill_block_super(sb);
1100}
1101
1102static struct file_system_type fuseblk_fs_type = {
1103 .owner = THIS_MODULE,
1104 .name = "fuseblk",
1105 .mount = fuse_mount_blk,
1106 .kill_sb = fuse_kill_sb_blk,
1107 .fs_flags = FS_REQUIRES_DEV | FS_HAS_SUBTYPE,
1108};
1109
1110static inline int register_fuseblk(void)
1111{
1112 return register_filesystem(&fuseblk_fs_type);
1113}
1114
1115static inline void unregister_fuseblk(void)
1116{
1117 unregister_filesystem(&fuseblk_fs_type);
1118}
1119#else
1120static inline int register_fuseblk(void)
1121{
1122 return 0;
1123}
1124
1125static inline void unregister_fuseblk(void)
1126{
1127}
1128#endif
1129
1130static void fuse_inode_init_once(void *foo)
1131{
1132 struct inode *inode = foo;
1133
1134 inode_init_once(inode);
1135}
1136
1137static int __init fuse_fs_init(void)
1138{
1139 int err;
1140
1141 err = register_filesystem(&fuse_fs_type);
1142 if (err)
1143 goto out;
1144
1145 err = register_fuseblk();
1146 if (err)
1147 goto out_unreg;
1148
1149 fuse_inode_cachep = kmem_cache_create("fuse_inode",
1150 sizeof(struct fuse_inode),
1151 0, SLAB_HWCACHE_ALIGN,
1152 fuse_inode_init_once);
1153 err = -ENOMEM;
1154 if (!fuse_inode_cachep)
1155 goto out_unreg2;
1156
1157 return 0;
1158
1159 out_unreg2:
1160 unregister_fuseblk();
1161 out_unreg:
1162 unregister_filesystem(&fuse_fs_type);
1163 out:
1164 return err;
1165}
1166
1167static void fuse_fs_cleanup(void)
1168{
1169 unregister_filesystem(&fuse_fs_type);
1170 unregister_fuseblk();
1171 kmem_cache_destroy(fuse_inode_cachep);
1172}
1173
1174static struct kobject *fuse_kobj;
1175static struct kobject *connections_kobj;
1176
1177static int fuse_sysfs_init(void)
1178{
1179 int err;
1180
1181 fuse_kobj = kobject_create_and_add("fuse", fs_kobj);
1182 if (!fuse_kobj) {
1183 err = -ENOMEM;
1184 goto out_err;
1185 }
1186
1187 connections_kobj = kobject_create_and_add("connections", fuse_kobj);
1188 if (!connections_kobj) {
1189 err = -ENOMEM;
1190 goto out_fuse_unregister;
1191 }
1192
1193 return 0;
1194
1195 out_fuse_unregister:
1196 kobject_put(fuse_kobj);
1197 out_err:
1198 return err;
1199}
1200
1201static void fuse_sysfs_cleanup(void)
1202{
1203 kobject_put(connections_kobj);
1204 kobject_put(fuse_kobj);
1205}
1206
1207static int __init fuse_init(void)
1208{
1209 int res;
1210
1211 printk(KERN_INFO "fuse init (API version %i.%i)\n",
1212 FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
1213
1214 INIT_LIST_HEAD(&fuse_conn_list);
1215 res = fuse_fs_init();
1216 if (res)
1217 goto err;
1218
1219 res = fuse_dev_init();
1220 if (res)
1221 goto err_fs_cleanup;
1222
1223 res = fuse_sysfs_init();
1224 if (res)
1225 goto err_dev_cleanup;
1226
1227 res = fuse_ctl_init();
1228 if (res)
1229 goto err_sysfs_cleanup;
1230
1231 sanitize_global_limit(&max_user_bgreq);
1232 sanitize_global_limit(&max_user_congthresh);
1233
1234 return 0;
1235
1236 err_sysfs_cleanup:
1237 fuse_sysfs_cleanup();
1238 err_dev_cleanup:
1239 fuse_dev_cleanup();
1240 err_fs_cleanup:
1241 fuse_fs_cleanup();
1242 err:
1243 return res;
1244}
1245
1246static void __exit fuse_exit(void)
1247{
1248 printk(KERN_DEBUG "fuse exit\n");
1249
1250 fuse_ctl_cleanup();
1251 fuse_sysfs_cleanup();
1252 fuse_fs_cleanup();
1253 fuse_dev_cleanup();
1254}
1255
1256module_init(fuse_init);
1257module_exit(fuse_exit);