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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 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);
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/fs_context.h>
19#include <linux/fs_parser.h>
20#include <linux/statfs.h>
21#include <linux/random.h>
22#include <linux/sched.h>
23#include <linux/exportfs.h>
24#include <linux/posix_acl.h>
25#include <linux/pid_namespace.h>
26#include <uapi/linux/magic.h>
27
28MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>");
29MODULE_DESCRIPTION("Filesystem in Userspace");
30MODULE_LICENSE("GPL");
31
32static struct kmem_cache *fuse_inode_cachep;
33struct list_head fuse_conn_list;
34DEFINE_MUTEX(fuse_mutex);
35
36static int set_global_limit(const char *val, const struct kernel_param *kp);
37
38unsigned int fuse_max_pages_limit = 256;
39
40unsigned max_user_bgreq;
41module_param_call(max_user_bgreq, set_global_limit, param_get_uint,
42 &max_user_bgreq, 0644);
43__MODULE_PARM_TYPE(max_user_bgreq, "uint");
44MODULE_PARM_DESC(max_user_bgreq,
45 "Global limit for the maximum number of backgrounded requests an "
46 "unprivileged user can set");
47
48unsigned max_user_congthresh;
49module_param_call(max_user_congthresh, set_global_limit, param_get_uint,
50 &max_user_congthresh, 0644);
51__MODULE_PARM_TYPE(max_user_congthresh, "uint");
52MODULE_PARM_DESC(max_user_congthresh,
53 "Global limit for the maximum congestion threshold an "
54 "unprivileged user can set");
55
56#define FUSE_DEFAULT_BLKSIZE 512
57
58/** Maximum number of outstanding background requests */
59#define FUSE_DEFAULT_MAX_BACKGROUND 12
60
61/** Congestion starts at 75% of maximum */
62#define FUSE_DEFAULT_CONGESTION_THRESHOLD (FUSE_DEFAULT_MAX_BACKGROUND * 3 / 4)
63
64#ifdef CONFIG_BLOCK
65static struct file_system_type fuseblk_fs_type;
66#endif
67
68struct fuse_forget_link *fuse_alloc_forget(void)
69{
70 return kzalloc(sizeof(struct fuse_forget_link), GFP_KERNEL_ACCOUNT);
71}
72
73static struct fuse_submount_lookup *fuse_alloc_submount_lookup(void)
74{
75 struct fuse_submount_lookup *sl;
76
77 sl = kzalloc(sizeof(struct fuse_submount_lookup), GFP_KERNEL_ACCOUNT);
78 if (!sl)
79 return NULL;
80 sl->forget = fuse_alloc_forget();
81 if (!sl->forget)
82 goto out_free;
83
84 return sl;
85
86out_free:
87 kfree(sl);
88 return NULL;
89}
90
91static struct inode *fuse_alloc_inode(struct super_block *sb)
92{
93 struct fuse_inode *fi;
94
95 fi = alloc_inode_sb(sb, fuse_inode_cachep, GFP_KERNEL);
96 if (!fi)
97 return NULL;
98
99 fi->i_time = 0;
100 fi->inval_mask = ~0;
101 fi->nodeid = 0;
102 fi->nlookup = 0;
103 fi->attr_version = 0;
104 fi->orig_ino = 0;
105 fi->state = 0;
106 fi->submount_lookup = NULL;
107 mutex_init(&fi->mutex);
108 spin_lock_init(&fi->lock);
109 fi->forget = fuse_alloc_forget();
110 if (!fi->forget)
111 goto out_free;
112
113 if (IS_ENABLED(CONFIG_FUSE_DAX) && !fuse_dax_inode_alloc(sb, fi))
114 goto out_free_forget;
115
116 if (IS_ENABLED(CONFIG_FUSE_PASSTHROUGH))
117 fuse_inode_backing_set(fi, NULL);
118
119 return &fi->inode;
120
121out_free_forget:
122 kfree(fi->forget);
123out_free:
124 kmem_cache_free(fuse_inode_cachep, fi);
125 return NULL;
126}
127
128static void fuse_free_inode(struct inode *inode)
129{
130 struct fuse_inode *fi = get_fuse_inode(inode);
131
132 mutex_destroy(&fi->mutex);
133 kfree(fi->forget);
134#ifdef CONFIG_FUSE_DAX
135 kfree(fi->dax);
136#endif
137 if (IS_ENABLED(CONFIG_FUSE_PASSTHROUGH))
138 fuse_backing_put(fuse_inode_backing(fi));
139
140 kmem_cache_free(fuse_inode_cachep, fi);
141}
142
143static void fuse_cleanup_submount_lookup(struct fuse_conn *fc,
144 struct fuse_submount_lookup *sl)
145{
146 if (!refcount_dec_and_test(&sl->count))
147 return;
148
149 fuse_queue_forget(fc, sl->forget, sl->nodeid, 1);
150 sl->forget = NULL;
151 kfree(sl);
152}
153
154static void fuse_evict_inode(struct inode *inode)
155{
156 struct fuse_inode *fi = get_fuse_inode(inode);
157
158 /* Will write inode on close/munmap and in all other dirtiers */
159 WARN_ON(inode->i_state & I_DIRTY_INODE);
160
161 truncate_inode_pages_final(&inode->i_data);
162 clear_inode(inode);
163 if (inode->i_sb->s_flags & SB_ACTIVE) {
164 struct fuse_conn *fc = get_fuse_conn(inode);
165
166 if (FUSE_IS_DAX(inode))
167 fuse_dax_inode_cleanup(inode);
168 if (fi->nlookup) {
169 fuse_queue_forget(fc, fi->forget, fi->nodeid,
170 fi->nlookup);
171 fi->forget = NULL;
172 }
173
174 if (fi->submount_lookup) {
175 fuse_cleanup_submount_lookup(fc, fi->submount_lookup);
176 fi->submount_lookup = NULL;
177 }
178 /*
179 * Evict of non-deleted inode may race with outstanding
180 * LOOKUP/READDIRPLUS requests and result in inconsistency when
181 * the request finishes. Deal with that here by bumping a
182 * counter that can be compared to the starting value.
183 */
184 if (inode->i_nlink > 0)
185 atomic64_inc(&fc->evict_ctr);
186 }
187 if (S_ISREG(inode->i_mode) && !fuse_is_bad(inode)) {
188 WARN_ON(fi->iocachectr != 0);
189 WARN_ON(!list_empty(&fi->write_files));
190 WARN_ON(!list_empty(&fi->queued_writes));
191 }
192}
193
194static int fuse_reconfigure(struct fs_context *fsc)
195{
196 struct super_block *sb = fsc->root->d_sb;
197
198 sync_filesystem(sb);
199 if (fsc->sb_flags & SB_MANDLOCK)
200 return -EINVAL;
201
202 return 0;
203}
204
205/*
206 * ino_t is 32-bits on 32-bit arch. We have to squash the 64-bit value down
207 * so that it will fit.
208 */
209static ino_t fuse_squash_ino(u64 ino64)
210{
211 ino_t ino = (ino_t) ino64;
212 if (sizeof(ino_t) < sizeof(u64))
213 ino ^= ino64 >> (sizeof(u64) - sizeof(ino_t)) * 8;
214 return ino;
215}
216
217void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
218 struct fuse_statx *sx,
219 u64 attr_valid, u32 cache_mask,
220 u64 evict_ctr)
221{
222 struct fuse_conn *fc = get_fuse_conn(inode);
223 struct fuse_inode *fi = get_fuse_inode(inode);
224
225 lockdep_assert_held(&fi->lock);
226
227 /*
228 * Clear basic stats from invalid mask.
229 *
230 * Don't do this if this is coming from a fuse_iget() call and there
231 * might have been a racing evict which would've invalidated the result
232 * if the attr_version would've been preserved.
233 *
234 * !evict_ctr -> this is create
235 * fi->attr_version != 0 -> this is not a new inode
236 * evict_ctr == fuse_get_evict_ctr() -> no evicts while during request
237 */
238 if (!evict_ctr || fi->attr_version || evict_ctr == fuse_get_evict_ctr(fc))
239 set_mask_bits(&fi->inval_mask, STATX_BASIC_STATS, 0);
240
241 fi->attr_version = atomic64_inc_return(&fc->attr_version);
242 fi->i_time = attr_valid;
243
244 inode->i_ino = fuse_squash_ino(attr->ino);
245 inode->i_mode = (inode->i_mode & S_IFMT) | (attr->mode & 07777);
246 set_nlink(inode, attr->nlink);
247 inode->i_uid = make_kuid(fc->user_ns, attr->uid);
248 inode->i_gid = make_kgid(fc->user_ns, attr->gid);
249 inode->i_blocks = attr->blocks;
250
251 /* Sanitize nsecs */
252 attr->atimensec = min_t(u32, attr->atimensec, NSEC_PER_SEC - 1);
253 attr->mtimensec = min_t(u32, attr->mtimensec, NSEC_PER_SEC - 1);
254 attr->ctimensec = min_t(u32, attr->ctimensec, NSEC_PER_SEC - 1);
255
256 inode_set_atime(inode, attr->atime, attr->atimensec);
257 /* mtime from server may be stale due to local buffered write */
258 if (!(cache_mask & STATX_MTIME)) {
259 inode_set_mtime(inode, attr->mtime, attr->mtimensec);
260 }
261 if (!(cache_mask & STATX_CTIME)) {
262 inode_set_ctime(inode, attr->ctime, attr->ctimensec);
263 }
264 if (sx) {
265 /* Sanitize nsecs */
266 sx->btime.tv_nsec =
267 min_t(u32, sx->btime.tv_nsec, NSEC_PER_SEC - 1);
268
269 /*
270 * Btime has been queried, cache is valid (whether or not btime
271 * is available or not) so clear STATX_BTIME from inval_mask.
272 *
273 * Availability of the btime attribute is indicated in
274 * FUSE_I_BTIME
275 */
276 set_mask_bits(&fi->inval_mask, STATX_BTIME, 0);
277 if (sx->mask & STATX_BTIME) {
278 set_bit(FUSE_I_BTIME, &fi->state);
279 fi->i_btime.tv_sec = sx->btime.tv_sec;
280 fi->i_btime.tv_nsec = sx->btime.tv_nsec;
281 }
282 }
283
284 if (attr->blksize != 0)
285 inode->i_blkbits = ilog2(attr->blksize);
286 else
287 inode->i_blkbits = inode->i_sb->s_blocksize_bits;
288
289 /*
290 * Don't set the sticky bit in i_mode, unless we want the VFS
291 * to check permissions. This prevents failures due to the
292 * check in may_delete().
293 */
294 fi->orig_i_mode = inode->i_mode;
295 if (!fc->default_permissions)
296 inode->i_mode &= ~S_ISVTX;
297
298 fi->orig_ino = attr->ino;
299
300 /*
301 * We are refreshing inode data and it is possible that another
302 * client set suid/sgid or security.capability xattr. So clear
303 * S_NOSEC. Ideally, we could have cleared it only if suid/sgid
304 * was set or if security.capability xattr was set. But we don't
305 * know if security.capability has been set or not. So clear it
306 * anyway. Its less efficient but should be safe.
307 */
308 inode->i_flags &= ~S_NOSEC;
309}
310
311u32 fuse_get_cache_mask(struct inode *inode)
312{
313 struct fuse_conn *fc = get_fuse_conn(inode);
314
315 if (!fc->writeback_cache || !S_ISREG(inode->i_mode))
316 return 0;
317
318 return STATX_MTIME | STATX_CTIME | STATX_SIZE;
319}
320
321static void fuse_change_attributes_i(struct inode *inode, struct fuse_attr *attr,
322 struct fuse_statx *sx, u64 attr_valid,
323 u64 attr_version, u64 evict_ctr)
324{
325 struct fuse_conn *fc = get_fuse_conn(inode);
326 struct fuse_inode *fi = get_fuse_inode(inode);
327 u32 cache_mask;
328 loff_t oldsize;
329 struct timespec64 old_mtime;
330
331 spin_lock(&fi->lock);
332 /*
333 * In case of writeback_cache enabled, writes update mtime, ctime and
334 * may update i_size. In these cases trust the cached value in the
335 * inode.
336 */
337 cache_mask = fuse_get_cache_mask(inode);
338 if (cache_mask & STATX_SIZE)
339 attr->size = i_size_read(inode);
340
341 if (cache_mask & STATX_MTIME) {
342 attr->mtime = inode_get_mtime_sec(inode);
343 attr->mtimensec = inode_get_mtime_nsec(inode);
344 }
345 if (cache_mask & STATX_CTIME) {
346 attr->ctime = inode_get_ctime_sec(inode);
347 attr->ctimensec = inode_get_ctime_nsec(inode);
348 }
349
350 if ((attr_version != 0 && fi->attr_version > attr_version) ||
351 test_bit(FUSE_I_SIZE_UNSTABLE, &fi->state)) {
352 spin_unlock(&fi->lock);
353 return;
354 }
355
356 old_mtime = inode_get_mtime(inode);
357 fuse_change_attributes_common(inode, attr, sx, attr_valid, cache_mask,
358 evict_ctr);
359
360 oldsize = inode->i_size;
361 /*
362 * In case of writeback_cache enabled, the cached writes beyond EOF
363 * extend local i_size without keeping userspace server in sync. So,
364 * attr->size coming from server can be stale. We cannot trust it.
365 */
366 if (!(cache_mask & STATX_SIZE))
367 i_size_write(inode, attr->size);
368 spin_unlock(&fi->lock);
369
370 if (!cache_mask && S_ISREG(inode->i_mode)) {
371 bool inval = false;
372
373 if (oldsize != attr->size) {
374 truncate_pagecache(inode, attr->size);
375 if (!fc->explicit_inval_data)
376 inval = true;
377 } else if (fc->auto_inval_data) {
378 struct timespec64 new_mtime = {
379 .tv_sec = attr->mtime,
380 .tv_nsec = attr->mtimensec,
381 };
382
383 /*
384 * Auto inval mode also checks and invalidates if mtime
385 * has changed.
386 */
387 if (!timespec64_equal(&old_mtime, &new_mtime))
388 inval = true;
389 }
390
391 if (inval)
392 invalidate_inode_pages2(inode->i_mapping);
393 }
394
395 if (IS_ENABLED(CONFIG_FUSE_DAX))
396 fuse_dax_dontcache(inode, attr->flags);
397}
398
399void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
400 struct fuse_statx *sx, u64 attr_valid,
401 u64 attr_version)
402{
403 fuse_change_attributes_i(inode, attr, sx, attr_valid, attr_version, 0);
404}
405
406static void fuse_init_submount_lookup(struct fuse_submount_lookup *sl,
407 u64 nodeid)
408{
409 sl->nodeid = nodeid;
410 refcount_set(&sl->count, 1);
411}
412
413static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr,
414 struct fuse_conn *fc)
415{
416 inode->i_mode = attr->mode & S_IFMT;
417 inode->i_size = attr->size;
418 inode_set_mtime(inode, attr->mtime, attr->mtimensec);
419 inode_set_ctime(inode, attr->ctime, attr->ctimensec);
420 if (S_ISREG(inode->i_mode)) {
421 fuse_init_common(inode);
422 fuse_init_file_inode(inode, attr->flags);
423 } else if (S_ISDIR(inode->i_mode))
424 fuse_init_dir(inode);
425 else if (S_ISLNK(inode->i_mode))
426 fuse_init_symlink(inode);
427 else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
428 S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
429 fuse_init_common(inode);
430 init_special_inode(inode, inode->i_mode,
431 new_decode_dev(attr->rdev));
432 } else
433 BUG();
434 /*
435 * Ensure that we don't cache acls for daemons without FUSE_POSIX_ACL
436 * so they see the exact same behavior as before.
437 */
438 if (!fc->posix_acl)
439 inode->i_acl = inode->i_default_acl = ACL_DONT_CACHE;
440}
441
442static int fuse_inode_eq(struct inode *inode, void *_nodeidp)
443{
444 u64 nodeid = *(u64 *) _nodeidp;
445 if (get_node_id(inode) == nodeid)
446 return 1;
447 else
448 return 0;
449}
450
451static int fuse_inode_set(struct inode *inode, void *_nodeidp)
452{
453 u64 nodeid = *(u64 *) _nodeidp;
454 get_fuse_inode(inode)->nodeid = nodeid;
455 return 0;
456}
457
458struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
459 int generation, struct fuse_attr *attr,
460 u64 attr_valid, u64 attr_version,
461 u64 evict_ctr)
462{
463 struct inode *inode;
464 struct fuse_inode *fi;
465 struct fuse_conn *fc = get_fuse_conn_super(sb);
466
467 /*
468 * Auto mount points get their node id from the submount root, which is
469 * not a unique identifier within this filesystem.
470 *
471 * To avoid conflicts, do not place submount points into the inode hash
472 * table.
473 */
474 if (fc->auto_submounts && (attr->flags & FUSE_ATTR_SUBMOUNT) &&
475 S_ISDIR(attr->mode)) {
476 struct fuse_inode *fi;
477
478 inode = new_inode(sb);
479 if (!inode)
480 return NULL;
481
482 fuse_init_inode(inode, attr, fc);
483 fi = get_fuse_inode(inode);
484 fi->nodeid = nodeid;
485 fi->submount_lookup = fuse_alloc_submount_lookup();
486 if (!fi->submount_lookup) {
487 iput(inode);
488 return NULL;
489 }
490 /* Sets nlookup = 1 on fi->submount_lookup->nlookup */
491 fuse_init_submount_lookup(fi->submount_lookup, nodeid);
492 inode->i_flags |= S_AUTOMOUNT;
493 goto done;
494 }
495
496retry:
497 inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid);
498 if (!inode)
499 return NULL;
500
501 if ((inode->i_state & I_NEW)) {
502 inode->i_flags |= S_NOATIME;
503 if (!fc->writeback_cache || !S_ISREG(attr->mode))
504 inode->i_flags |= S_NOCMTIME;
505 inode->i_generation = generation;
506 fuse_init_inode(inode, attr, fc);
507 unlock_new_inode(inode);
508 } else if (fuse_stale_inode(inode, generation, attr)) {
509 /* nodeid was reused, any I/O on the old inode should fail */
510 fuse_make_bad(inode);
511 if (inode != d_inode(sb->s_root)) {
512 remove_inode_hash(inode);
513 iput(inode);
514 goto retry;
515 }
516 }
517 fi = get_fuse_inode(inode);
518 spin_lock(&fi->lock);
519 fi->nlookup++;
520 spin_unlock(&fi->lock);
521done:
522 fuse_change_attributes_i(inode, attr, NULL, attr_valid, attr_version,
523 evict_ctr);
524 return inode;
525}
526
527struct inode *fuse_ilookup(struct fuse_conn *fc, u64 nodeid,
528 struct fuse_mount **fm)
529{
530 struct fuse_mount *fm_iter;
531 struct inode *inode;
532
533 WARN_ON(!rwsem_is_locked(&fc->killsb));
534 list_for_each_entry(fm_iter, &fc->mounts, fc_entry) {
535 if (!fm_iter->sb)
536 continue;
537
538 inode = ilookup5(fm_iter->sb, nodeid, fuse_inode_eq, &nodeid);
539 if (inode) {
540 if (fm)
541 *fm = fm_iter;
542 return inode;
543 }
544 }
545
546 return NULL;
547}
548
549int fuse_reverse_inval_inode(struct fuse_conn *fc, u64 nodeid,
550 loff_t offset, loff_t len)
551{
552 struct fuse_inode *fi;
553 struct inode *inode;
554 pgoff_t pg_start;
555 pgoff_t pg_end;
556
557 inode = fuse_ilookup(fc, nodeid, NULL);
558 if (!inode)
559 return -ENOENT;
560
561 fi = get_fuse_inode(inode);
562 spin_lock(&fi->lock);
563 fi->attr_version = atomic64_inc_return(&fc->attr_version);
564 spin_unlock(&fi->lock);
565
566 fuse_invalidate_attr(inode);
567 forget_all_cached_acls(inode);
568 if (offset >= 0) {
569 pg_start = offset >> PAGE_SHIFT;
570 if (len <= 0)
571 pg_end = -1;
572 else
573 pg_end = (offset + len - 1) >> PAGE_SHIFT;
574 invalidate_inode_pages2_range(inode->i_mapping,
575 pg_start, pg_end);
576 }
577 iput(inode);
578 return 0;
579}
580
581bool fuse_lock_inode(struct inode *inode)
582{
583 bool locked = false;
584
585 if (!get_fuse_conn(inode)->parallel_dirops) {
586 mutex_lock(&get_fuse_inode(inode)->mutex);
587 locked = true;
588 }
589
590 return locked;
591}
592
593void fuse_unlock_inode(struct inode *inode, bool locked)
594{
595 if (locked)
596 mutex_unlock(&get_fuse_inode(inode)->mutex);
597}
598
599static void fuse_umount_begin(struct super_block *sb)
600{
601 struct fuse_conn *fc = get_fuse_conn_super(sb);
602
603 if (fc->no_force_umount)
604 return;
605
606 fuse_abort_conn(fc);
607
608 // Only retire block-device-based superblocks.
609 if (sb->s_bdev != NULL)
610 retire_super(sb);
611}
612
613static void fuse_send_destroy(struct fuse_mount *fm)
614{
615 if (fm->fc->conn_init) {
616 FUSE_ARGS(args);
617
618 args.opcode = FUSE_DESTROY;
619 args.force = true;
620 args.nocreds = true;
621 fuse_simple_request(fm, &args);
622 }
623}
624
625static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
626{
627 stbuf->f_type = FUSE_SUPER_MAGIC;
628 stbuf->f_bsize = attr->bsize;
629 stbuf->f_frsize = attr->frsize;
630 stbuf->f_blocks = attr->blocks;
631 stbuf->f_bfree = attr->bfree;
632 stbuf->f_bavail = attr->bavail;
633 stbuf->f_files = attr->files;
634 stbuf->f_ffree = attr->ffree;
635 stbuf->f_namelen = attr->namelen;
636 /* fsid is left zero */
637}
638
639static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf)
640{
641 struct super_block *sb = dentry->d_sb;
642 struct fuse_mount *fm = get_fuse_mount_super(sb);
643 FUSE_ARGS(args);
644 struct fuse_statfs_out outarg;
645 int err;
646
647 if (!fuse_allow_current_process(fm->fc)) {
648 buf->f_type = FUSE_SUPER_MAGIC;
649 return 0;
650 }
651
652 memset(&outarg, 0, sizeof(outarg));
653 args.in_numargs = 0;
654 args.opcode = FUSE_STATFS;
655 args.nodeid = get_node_id(d_inode(dentry));
656 args.out_numargs = 1;
657 args.out_args[0].size = sizeof(outarg);
658 args.out_args[0].value = &outarg;
659 err = fuse_simple_request(fm, &args);
660 if (!err)
661 convert_fuse_statfs(buf, &outarg.st);
662 return err;
663}
664
665static struct fuse_sync_bucket *fuse_sync_bucket_alloc(void)
666{
667 struct fuse_sync_bucket *bucket;
668
669 bucket = kzalloc(sizeof(*bucket), GFP_KERNEL | __GFP_NOFAIL);
670 if (bucket) {
671 init_waitqueue_head(&bucket->waitq);
672 /* Initial active count */
673 atomic_set(&bucket->count, 1);
674 }
675 return bucket;
676}
677
678static void fuse_sync_fs_writes(struct fuse_conn *fc)
679{
680 struct fuse_sync_bucket *bucket, *new_bucket;
681 int count;
682
683 new_bucket = fuse_sync_bucket_alloc();
684 spin_lock(&fc->lock);
685 bucket = rcu_dereference_protected(fc->curr_bucket, 1);
686 count = atomic_read(&bucket->count);
687 WARN_ON(count < 1);
688 /* No outstanding writes? */
689 if (count == 1) {
690 spin_unlock(&fc->lock);
691 kfree(new_bucket);
692 return;
693 }
694
695 /*
696 * Completion of new bucket depends on completion of this bucket, so add
697 * one more count.
698 */
699 atomic_inc(&new_bucket->count);
700 rcu_assign_pointer(fc->curr_bucket, new_bucket);
701 spin_unlock(&fc->lock);
702 /*
703 * Drop initial active count. At this point if all writes in this and
704 * ancestor buckets complete, the count will go to zero and this task
705 * will be woken up.
706 */
707 atomic_dec(&bucket->count);
708
709 wait_event(bucket->waitq, atomic_read(&bucket->count) == 0);
710
711 /* Drop temp count on descendant bucket */
712 fuse_sync_bucket_dec(new_bucket);
713 kfree_rcu(bucket, rcu);
714}
715
716static int fuse_sync_fs(struct super_block *sb, int wait)
717{
718 struct fuse_mount *fm = get_fuse_mount_super(sb);
719 struct fuse_conn *fc = fm->fc;
720 struct fuse_syncfs_in inarg;
721 FUSE_ARGS(args);
722 int err;
723
724 /*
725 * Userspace cannot handle the wait == 0 case. Avoid a
726 * gratuitous roundtrip.
727 */
728 if (!wait)
729 return 0;
730
731 /* The filesystem is being unmounted. Nothing to do. */
732 if (!sb->s_root)
733 return 0;
734
735 if (!fc->sync_fs)
736 return 0;
737
738 fuse_sync_fs_writes(fc);
739
740 memset(&inarg, 0, sizeof(inarg));
741 args.in_numargs = 1;
742 args.in_args[0].size = sizeof(inarg);
743 args.in_args[0].value = &inarg;
744 args.opcode = FUSE_SYNCFS;
745 args.nodeid = get_node_id(sb->s_root->d_inode);
746 args.out_numargs = 0;
747
748 err = fuse_simple_request(fm, &args);
749 if (err == -ENOSYS) {
750 fc->sync_fs = 0;
751 err = 0;
752 }
753
754 return err;
755}
756
757enum {
758 OPT_SOURCE,
759 OPT_SUBTYPE,
760 OPT_FD,
761 OPT_ROOTMODE,
762 OPT_USER_ID,
763 OPT_GROUP_ID,
764 OPT_DEFAULT_PERMISSIONS,
765 OPT_ALLOW_OTHER,
766 OPT_MAX_READ,
767 OPT_BLKSIZE,
768 OPT_ERR
769};
770
771static const struct fs_parameter_spec fuse_fs_parameters[] = {
772 fsparam_string ("source", OPT_SOURCE),
773 fsparam_u32 ("fd", OPT_FD),
774 fsparam_u32oct ("rootmode", OPT_ROOTMODE),
775 fsparam_uid ("user_id", OPT_USER_ID),
776 fsparam_gid ("group_id", OPT_GROUP_ID),
777 fsparam_flag ("default_permissions", OPT_DEFAULT_PERMISSIONS),
778 fsparam_flag ("allow_other", OPT_ALLOW_OTHER),
779 fsparam_u32 ("max_read", OPT_MAX_READ),
780 fsparam_u32 ("blksize", OPT_BLKSIZE),
781 fsparam_string ("subtype", OPT_SUBTYPE),
782 {}
783};
784
785static int fuse_parse_param(struct fs_context *fsc, struct fs_parameter *param)
786{
787 struct fs_parse_result result;
788 struct fuse_fs_context *ctx = fsc->fs_private;
789 int opt;
790 kuid_t kuid;
791 kgid_t kgid;
792
793 if (fsc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
794 /*
795 * Ignore options coming from mount(MS_REMOUNT) for backward
796 * compatibility.
797 */
798 if (fsc->oldapi)
799 return 0;
800
801 return invalfc(fsc, "No changes allowed in reconfigure");
802 }
803
804 opt = fs_parse(fsc, fuse_fs_parameters, param, &result);
805 if (opt < 0)
806 return opt;
807
808 switch (opt) {
809 case OPT_SOURCE:
810 if (fsc->source)
811 return invalfc(fsc, "Multiple sources specified");
812 fsc->source = param->string;
813 param->string = NULL;
814 break;
815
816 case OPT_SUBTYPE:
817 if (ctx->subtype)
818 return invalfc(fsc, "Multiple subtypes specified");
819 ctx->subtype = param->string;
820 param->string = NULL;
821 return 0;
822
823 case OPT_FD:
824 ctx->fd = result.uint_32;
825 ctx->fd_present = true;
826 break;
827
828 case OPT_ROOTMODE:
829 if (!fuse_valid_type(result.uint_32))
830 return invalfc(fsc, "Invalid rootmode");
831 ctx->rootmode = result.uint_32;
832 ctx->rootmode_present = true;
833 break;
834
835 case OPT_USER_ID:
836 kuid = result.uid;
837 /*
838 * The requested uid must be representable in the
839 * filesystem's idmapping.
840 */
841 if (!kuid_has_mapping(fsc->user_ns, kuid))
842 return invalfc(fsc, "Invalid user_id");
843 ctx->user_id = kuid;
844 ctx->user_id_present = true;
845 break;
846
847 case OPT_GROUP_ID:
848 kgid = result.gid;
849 /*
850 * The requested gid must be representable in the
851 * filesystem's idmapping.
852 */
853 if (!kgid_has_mapping(fsc->user_ns, kgid))
854 return invalfc(fsc, "Invalid group_id");
855 ctx->group_id = kgid;
856 ctx->group_id_present = true;
857 break;
858
859 case OPT_DEFAULT_PERMISSIONS:
860 ctx->default_permissions = true;
861 break;
862
863 case OPT_ALLOW_OTHER:
864 ctx->allow_other = true;
865 break;
866
867 case OPT_MAX_READ:
868 ctx->max_read = result.uint_32;
869 break;
870
871 case OPT_BLKSIZE:
872 if (!ctx->is_bdev)
873 return invalfc(fsc, "blksize only supported for fuseblk");
874 ctx->blksize = result.uint_32;
875 break;
876
877 default:
878 return -EINVAL;
879 }
880
881 return 0;
882}
883
884static void fuse_free_fsc(struct fs_context *fsc)
885{
886 struct fuse_fs_context *ctx = fsc->fs_private;
887
888 if (ctx) {
889 kfree(ctx->subtype);
890 kfree(ctx);
891 }
892}
893
894static int fuse_show_options(struct seq_file *m, struct dentry *root)
895{
896 struct super_block *sb = root->d_sb;
897 struct fuse_conn *fc = get_fuse_conn_super(sb);
898
899 if (fc->legacy_opts_show) {
900 seq_printf(m, ",user_id=%u",
901 from_kuid_munged(fc->user_ns, fc->user_id));
902 seq_printf(m, ",group_id=%u",
903 from_kgid_munged(fc->user_ns, fc->group_id));
904 if (fc->default_permissions)
905 seq_puts(m, ",default_permissions");
906 if (fc->allow_other)
907 seq_puts(m, ",allow_other");
908 if (fc->max_read != ~0)
909 seq_printf(m, ",max_read=%u", fc->max_read);
910 if (sb->s_bdev && sb->s_blocksize != FUSE_DEFAULT_BLKSIZE)
911 seq_printf(m, ",blksize=%lu", sb->s_blocksize);
912 }
913#ifdef CONFIG_FUSE_DAX
914 if (fc->dax_mode == FUSE_DAX_ALWAYS)
915 seq_puts(m, ",dax=always");
916 else if (fc->dax_mode == FUSE_DAX_NEVER)
917 seq_puts(m, ",dax=never");
918 else if (fc->dax_mode == FUSE_DAX_INODE_USER)
919 seq_puts(m, ",dax=inode");
920#endif
921
922 return 0;
923}
924
925static void fuse_iqueue_init(struct fuse_iqueue *fiq,
926 const struct fuse_iqueue_ops *ops,
927 void *priv)
928{
929 memset(fiq, 0, sizeof(struct fuse_iqueue));
930 spin_lock_init(&fiq->lock);
931 init_waitqueue_head(&fiq->waitq);
932 INIT_LIST_HEAD(&fiq->pending);
933 INIT_LIST_HEAD(&fiq->interrupts);
934 fiq->forget_list_tail = &fiq->forget_list_head;
935 fiq->connected = 1;
936 fiq->ops = ops;
937 fiq->priv = priv;
938}
939
940static void fuse_pqueue_init(struct fuse_pqueue *fpq)
941{
942 unsigned int i;
943
944 spin_lock_init(&fpq->lock);
945 for (i = 0; i < FUSE_PQ_HASH_SIZE; i++)
946 INIT_LIST_HEAD(&fpq->processing[i]);
947 INIT_LIST_HEAD(&fpq->io);
948 fpq->connected = 1;
949}
950
951void fuse_conn_init(struct fuse_conn *fc, struct fuse_mount *fm,
952 struct user_namespace *user_ns,
953 const struct fuse_iqueue_ops *fiq_ops, void *fiq_priv)
954{
955 memset(fc, 0, sizeof(*fc));
956 spin_lock_init(&fc->lock);
957 spin_lock_init(&fc->bg_lock);
958 init_rwsem(&fc->killsb);
959 refcount_set(&fc->count, 1);
960 atomic_set(&fc->dev_count, 1);
961 init_waitqueue_head(&fc->blocked_waitq);
962 fuse_iqueue_init(&fc->iq, fiq_ops, fiq_priv);
963 INIT_LIST_HEAD(&fc->bg_queue);
964 INIT_LIST_HEAD(&fc->entry);
965 INIT_LIST_HEAD(&fc->devices);
966 atomic_set(&fc->num_waiting, 0);
967 fc->max_background = FUSE_DEFAULT_MAX_BACKGROUND;
968 fc->congestion_threshold = FUSE_DEFAULT_CONGESTION_THRESHOLD;
969 atomic64_set(&fc->khctr, 0);
970 fc->polled_files = RB_ROOT;
971 fc->blocked = 0;
972 fc->initialized = 0;
973 fc->connected = 1;
974 atomic64_set(&fc->attr_version, 1);
975 atomic64_set(&fc->evict_ctr, 1);
976 get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key));
977 fc->pid_ns = get_pid_ns(task_active_pid_ns(current));
978 fc->user_ns = get_user_ns(user_ns);
979 fc->max_pages = FUSE_DEFAULT_MAX_PAGES_PER_REQ;
980 fc->max_pages_limit = fuse_max_pages_limit;
981
982 if (IS_ENABLED(CONFIG_FUSE_PASSTHROUGH))
983 fuse_backing_files_init(fc);
984
985 INIT_LIST_HEAD(&fc->mounts);
986 list_add(&fm->fc_entry, &fc->mounts);
987 fm->fc = fc;
988}
989EXPORT_SYMBOL_GPL(fuse_conn_init);
990
991static void delayed_release(struct rcu_head *p)
992{
993 struct fuse_conn *fc = container_of(p, struct fuse_conn, rcu);
994
995 put_user_ns(fc->user_ns);
996 fc->release(fc);
997}
998
999void fuse_conn_put(struct fuse_conn *fc)
1000{
1001 if (refcount_dec_and_test(&fc->count)) {
1002 struct fuse_iqueue *fiq = &fc->iq;
1003 struct fuse_sync_bucket *bucket;
1004
1005 if (IS_ENABLED(CONFIG_FUSE_DAX))
1006 fuse_dax_conn_free(fc);
1007 if (fiq->ops->release)
1008 fiq->ops->release(fiq);
1009 put_pid_ns(fc->pid_ns);
1010 bucket = rcu_dereference_protected(fc->curr_bucket, 1);
1011 if (bucket) {
1012 WARN_ON(atomic_read(&bucket->count) != 1);
1013 kfree(bucket);
1014 }
1015 if (IS_ENABLED(CONFIG_FUSE_PASSTHROUGH))
1016 fuse_backing_files_free(fc);
1017 call_rcu(&fc->rcu, delayed_release);
1018 }
1019}
1020EXPORT_SYMBOL_GPL(fuse_conn_put);
1021
1022struct fuse_conn *fuse_conn_get(struct fuse_conn *fc)
1023{
1024 refcount_inc(&fc->count);
1025 return fc;
1026}
1027EXPORT_SYMBOL_GPL(fuse_conn_get);
1028
1029static struct inode *fuse_get_root_inode(struct super_block *sb, unsigned mode)
1030{
1031 struct fuse_attr attr;
1032 memset(&attr, 0, sizeof(attr));
1033
1034 attr.mode = mode;
1035 attr.ino = FUSE_ROOT_ID;
1036 attr.nlink = 1;
1037 return fuse_iget(sb, FUSE_ROOT_ID, 0, &attr, 0, 0, 0);
1038}
1039
1040struct fuse_inode_handle {
1041 u64 nodeid;
1042 u32 generation;
1043};
1044
1045static struct dentry *fuse_get_dentry(struct super_block *sb,
1046 struct fuse_inode_handle *handle)
1047{
1048 struct fuse_conn *fc = get_fuse_conn_super(sb);
1049 struct inode *inode;
1050 struct dentry *entry;
1051 int err = -ESTALE;
1052
1053 if (handle->nodeid == 0)
1054 goto out_err;
1055
1056 inode = ilookup5(sb, handle->nodeid, fuse_inode_eq, &handle->nodeid);
1057 if (!inode) {
1058 struct fuse_entry_out outarg;
1059 const struct qstr name = QSTR_INIT(".", 1);
1060
1061 if (!fc->export_support)
1062 goto out_err;
1063
1064 err = fuse_lookup_name(sb, handle->nodeid, &name, &outarg,
1065 &inode);
1066 if (err && err != -ENOENT)
1067 goto out_err;
1068 if (err || !inode) {
1069 err = -ESTALE;
1070 goto out_err;
1071 }
1072 err = -EIO;
1073 if (get_node_id(inode) != handle->nodeid)
1074 goto out_iput;
1075 }
1076 err = -ESTALE;
1077 if (inode->i_generation != handle->generation)
1078 goto out_iput;
1079
1080 entry = d_obtain_alias(inode);
1081 if (!IS_ERR(entry) && get_node_id(inode) != FUSE_ROOT_ID)
1082 fuse_invalidate_entry_cache(entry);
1083
1084 return entry;
1085
1086 out_iput:
1087 iput(inode);
1088 out_err:
1089 return ERR_PTR(err);
1090}
1091
1092static int fuse_encode_fh(struct inode *inode, u32 *fh, int *max_len,
1093 struct inode *parent)
1094{
1095 int len = parent ? 6 : 3;
1096 u64 nodeid;
1097 u32 generation;
1098
1099 if (*max_len < len) {
1100 *max_len = len;
1101 return FILEID_INVALID;
1102 }
1103
1104 nodeid = get_fuse_inode(inode)->nodeid;
1105 generation = inode->i_generation;
1106
1107 fh[0] = (u32)(nodeid >> 32);
1108 fh[1] = (u32)(nodeid & 0xffffffff);
1109 fh[2] = generation;
1110
1111 if (parent) {
1112 nodeid = get_fuse_inode(parent)->nodeid;
1113 generation = parent->i_generation;
1114
1115 fh[3] = (u32)(nodeid >> 32);
1116 fh[4] = (u32)(nodeid & 0xffffffff);
1117 fh[5] = generation;
1118 }
1119
1120 *max_len = len;
1121 return parent ? FILEID_INO64_GEN_PARENT : FILEID_INO64_GEN;
1122}
1123
1124static struct dentry *fuse_fh_to_dentry(struct super_block *sb,
1125 struct fid *fid, int fh_len, int fh_type)
1126{
1127 struct fuse_inode_handle handle;
1128
1129 if ((fh_type != FILEID_INO64_GEN &&
1130 fh_type != FILEID_INO64_GEN_PARENT) || fh_len < 3)
1131 return NULL;
1132
1133 handle.nodeid = (u64) fid->raw[0] << 32;
1134 handle.nodeid |= (u64) fid->raw[1];
1135 handle.generation = fid->raw[2];
1136 return fuse_get_dentry(sb, &handle);
1137}
1138
1139static struct dentry *fuse_fh_to_parent(struct super_block *sb,
1140 struct fid *fid, int fh_len, int fh_type)
1141{
1142 struct fuse_inode_handle parent;
1143
1144 if (fh_type != FILEID_INO64_GEN_PARENT || fh_len < 6)
1145 return NULL;
1146
1147 parent.nodeid = (u64) fid->raw[3] << 32;
1148 parent.nodeid |= (u64) fid->raw[4];
1149 parent.generation = fid->raw[5];
1150 return fuse_get_dentry(sb, &parent);
1151}
1152
1153static struct dentry *fuse_get_parent(struct dentry *child)
1154{
1155 struct inode *child_inode = d_inode(child);
1156 struct fuse_conn *fc = get_fuse_conn(child_inode);
1157 struct inode *inode;
1158 struct dentry *parent;
1159 struct fuse_entry_out outarg;
1160 int err;
1161
1162 if (!fc->export_support)
1163 return ERR_PTR(-ESTALE);
1164
1165 err = fuse_lookup_name(child_inode->i_sb, get_node_id(child_inode),
1166 &dotdot_name, &outarg, &inode);
1167 if (err) {
1168 if (err == -ENOENT)
1169 return ERR_PTR(-ESTALE);
1170 return ERR_PTR(err);
1171 }
1172
1173 parent = d_obtain_alias(inode);
1174 if (!IS_ERR(parent) && get_node_id(inode) != FUSE_ROOT_ID)
1175 fuse_invalidate_entry_cache(parent);
1176
1177 return parent;
1178}
1179
1180/* only for fid encoding; no support for file handle */
1181static const struct export_operations fuse_export_fid_operations = {
1182 .encode_fh = fuse_encode_fh,
1183};
1184
1185static const struct export_operations fuse_export_operations = {
1186 .fh_to_dentry = fuse_fh_to_dentry,
1187 .fh_to_parent = fuse_fh_to_parent,
1188 .encode_fh = fuse_encode_fh,
1189 .get_parent = fuse_get_parent,
1190};
1191
1192static const struct super_operations fuse_super_operations = {
1193 .alloc_inode = fuse_alloc_inode,
1194 .free_inode = fuse_free_inode,
1195 .evict_inode = fuse_evict_inode,
1196 .write_inode = fuse_write_inode,
1197 .drop_inode = generic_delete_inode,
1198 .umount_begin = fuse_umount_begin,
1199 .statfs = fuse_statfs,
1200 .sync_fs = fuse_sync_fs,
1201 .show_options = fuse_show_options,
1202};
1203
1204static void sanitize_global_limit(unsigned *limit)
1205{
1206 /*
1207 * The default maximum number of async requests is calculated to consume
1208 * 1/2^13 of the total memory, assuming 392 bytes per request.
1209 */
1210 if (*limit == 0)
1211 *limit = ((totalram_pages() << PAGE_SHIFT) >> 13) / 392;
1212
1213 if (*limit >= 1 << 16)
1214 *limit = (1 << 16) - 1;
1215}
1216
1217static int set_global_limit(const char *val, const struct kernel_param *kp)
1218{
1219 int rv;
1220
1221 rv = param_set_uint(val, kp);
1222 if (rv)
1223 return rv;
1224
1225 sanitize_global_limit((unsigned *)kp->arg);
1226
1227 return 0;
1228}
1229
1230static void process_init_limits(struct fuse_conn *fc, struct fuse_init_out *arg)
1231{
1232 int cap_sys_admin = capable(CAP_SYS_ADMIN);
1233
1234 if (arg->minor < 13)
1235 return;
1236
1237 sanitize_global_limit(&max_user_bgreq);
1238 sanitize_global_limit(&max_user_congthresh);
1239
1240 spin_lock(&fc->bg_lock);
1241 if (arg->max_background) {
1242 fc->max_background = arg->max_background;
1243
1244 if (!cap_sys_admin && fc->max_background > max_user_bgreq)
1245 fc->max_background = max_user_bgreq;
1246 }
1247 if (arg->congestion_threshold) {
1248 fc->congestion_threshold = arg->congestion_threshold;
1249
1250 if (!cap_sys_admin &&
1251 fc->congestion_threshold > max_user_congthresh)
1252 fc->congestion_threshold = max_user_congthresh;
1253 }
1254 spin_unlock(&fc->bg_lock);
1255}
1256
1257struct fuse_init_args {
1258 struct fuse_args args;
1259 struct fuse_init_in in;
1260 struct fuse_init_out out;
1261};
1262
1263static void process_init_reply(struct fuse_mount *fm, struct fuse_args *args,
1264 int error)
1265{
1266 struct fuse_conn *fc = fm->fc;
1267 struct fuse_init_args *ia = container_of(args, typeof(*ia), args);
1268 struct fuse_init_out *arg = &ia->out;
1269 bool ok = true;
1270
1271 if (error || arg->major != FUSE_KERNEL_VERSION)
1272 ok = false;
1273 else {
1274 unsigned long ra_pages;
1275
1276 process_init_limits(fc, arg);
1277
1278 if (arg->minor >= 6) {
1279 u64 flags = arg->flags;
1280
1281 if (flags & FUSE_INIT_EXT)
1282 flags |= (u64) arg->flags2 << 32;
1283
1284 ra_pages = arg->max_readahead / PAGE_SIZE;
1285 if (flags & FUSE_ASYNC_READ)
1286 fc->async_read = 1;
1287 if (!(flags & FUSE_POSIX_LOCKS))
1288 fc->no_lock = 1;
1289 if (arg->minor >= 17) {
1290 if (!(flags & FUSE_FLOCK_LOCKS))
1291 fc->no_flock = 1;
1292 } else {
1293 if (!(flags & FUSE_POSIX_LOCKS))
1294 fc->no_flock = 1;
1295 }
1296 if (flags & FUSE_ATOMIC_O_TRUNC)
1297 fc->atomic_o_trunc = 1;
1298 if (arg->minor >= 9) {
1299 /* LOOKUP has dependency on proto version */
1300 if (flags & FUSE_EXPORT_SUPPORT)
1301 fc->export_support = 1;
1302 }
1303 if (flags & FUSE_BIG_WRITES)
1304 fc->big_writes = 1;
1305 if (flags & FUSE_DONT_MASK)
1306 fc->dont_mask = 1;
1307 if (flags & FUSE_AUTO_INVAL_DATA)
1308 fc->auto_inval_data = 1;
1309 else if (flags & FUSE_EXPLICIT_INVAL_DATA)
1310 fc->explicit_inval_data = 1;
1311 if (flags & FUSE_DO_READDIRPLUS) {
1312 fc->do_readdirplus = 1;
1313 if (flags & FUSE_READDIRPLUS_AUTO)
1314 fc->readdirplus_auto = 1;
1315 }
1316 if (flags & FUSE_ASYNC_DIO)
1317 fc->async_dio = 1;
1318 if (flags & FUSE_WRITEBACK_CACHE)
1319 fc->writeback_cache = 1;
1320 if (flags & FUSE_PARALLEL_DIROPS)
1321 fc->parallel_dirops = 1;
1322 if (flags & FUSE_HANDLE_KILLPRIV)
1323 fc->handle_killpriv = 1;
1324 if (arg->time_gran && arg->time_gran <= 1000000000)
1325 fm->sb->s_time_gran = arg->time_gran;
1326 if ((flags & FUSE_POSIX_ACL)) {
1327 fc->default_permissions = 1;
1328 fc->posix_acl = 1;
1329 }
1330 if (flags & FUSE_CACHE_SYMLINKS)
1331 fc->cache_symlinks = 1;
1332 if (flags & FUSE_ABORT_ERROR)
1333 fc->abort_err = 1;
1334 if (flags & FUSE_MAX_PAGES) {
1335 fc->max_pages =
1336 min_t(unsigned int, fc->max_pages_limit,
1337 max_t(unsigned int, arg->max_pages, 1));
1338 }
1339 if (IS_ENABLED(CONFIG_FUSE_DAX)) {
1340 if (flags & FUSE_MAP_ALIGNMENT &&
1341 !fuse_dax_check_alignment(fc, arg->map_alignment)) {
1342 ok = false;
1343 }
1344 if (flags & FUSE_HAS_INODE_DAX)
1345 fc->inode_dax = 1;
1346 }
1347 if (flags & FUSE_HANDLE_KILLPRIV_V2) {
1348 fc->handle_killpriv_v2 = 1;
1349 fm->sb->s_flags |= SB_NOSEC;
1350 }
1351 if (flags & FUSE_SETXATTR_EXT)
1352 fc->setxattr_ext = 1;
1353 if (flags & FUSE_SECURITY_CTX)
1354 fc->init_security = 1;
1355 if (flags & FUSE_CREATE_SUPP_GROUP)
1356 fc->create_supp_group = 1;
1357 if (flags & FUSE_DIRECT_IO_ALLOW_MMAP)
1358 fc->direct_io_allow_mmap = 1;
1359 /*
1360 * max_stack_depth is the max stack depth of FUSE fs,
1361 * so it has to be at least 1 to support passthrough
1362 * to backing files.
1363 *
1364 * with max_stack_depth > 1, the backing files can be
1365 * on a stacked fs (e.g. overlayfs) themselves and with
1366 * max_stack_depth == 1, FUSE fs can be stacked as the
1367 * underlying fs of a stacked fs (e.g. overlayfs).
1368 *
1369 * Also don't allow the combination of FUSE_PASSTHROUGH
1370 * and FUSE_WRITEBACK_CACHE, current design doesn't handle
1371 * them together.
1372 */
1373 if (IS_ENABLED(CONFIG_FUSE_PASSTHROUGH) &&
1374 (flags & FUSE_PASSTHROUGH) &&
1375 arg->max_stack_depth > 0 &&
1376 arg->max_stack_depth <= FILESYSTEM_MAX_STACK_DEPTH &&
1377 !(flags & FUSE_WRITEBACK_CACHE)) {
1378 fc->passthrough = 1;
1379 fc->max_stack_depth = arg->max_stack_depth;
1380 fm->sb->s_stack_depth = arg->max_stack_depth;
1381 }
1382 if (flags & FUSE_NO_EXPORT_SUPPORT)
1383 fm->sb->s_export_op = &fuse_export_fid_operations;
1384 if (flags & FUSE_ALLOW_IDMAP) {
1385 if (fc->default_permissions)
1386 fm->sb->s_iflags &= ~SB_I_NOIDMAP;
1387 else
1388 ok = false;
1389 }
1390 } else {
1391 ra_pages = fc->max_read / PAGE_SIZE;
1392 fc->no_lock = 1;
1393 fc->no_flock = 1;
1394 }
1395
1396 fm->sb->s_bdi->ra_pages =
1397 min(fm->sb->s_bdi->ra_pages, ra_pages);
1398 fc->minor = arg->minor;
1399 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
1400 fc->max_write = max_t(unsigned, 4096, fc->max_write);
1401 fc->conn_init = 1;
1402 }
1403 kfree(ia);
1404
1405 if (!ok) {
1406 fc->conn_init = 0;
1407 fc->conn_error = 1;
1408 }
1409
1410 fuse_set_initialized(fc);
1411 wake_up_all(&fc->blocked_waitq);
1412}
1413
1414void fuse_send_init(struct fuse_mount *fm)
1415{
1416 struct fuse_init_args *ia;
1417 u64 flags;
1418
1419 ia = kzalloc(sizeof(*ia), GFP_KERNEL | __GFP_NOFAIL);
1420
1421 ia->in.major = FUSE_KERNEL_VERSION;
1422 ia->in.minor = FUSE_KERNEL_MINOR_VERSION;
1423 ia->in.max_readahead = fm->sb->s_bdi->ra_pages * PAGE_SIZE;
1424 flags =
1425 FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_ATOMIC_O_TRUNC |
1426 FUSE_EXPORT_SUPPORT | FUSE_BIG_WRITES | FUSE_DONT_MASK |
1427 FUSE_SPLICE_WRITE | FUSE_SPLICE_MOVE | FUSE_SPLICE_READ |
1428 FUSE_FLOCK_LOCKS | FUSE_HAS_IOCTL_DIR | FUSE_AUTO_INVAL_DATA |
1429 FUSE_DO_READDIRPLUS | FUSE_READDIRPLUS_AUTO | FUSE_ASYNC_DIO |
1430 FUSE_WRITEBACK_CACHE | FUSE_NO_OPEN_SUPPORT |
1431 FUSE_PARALLEL_DIROPS | FUSE_HANDLE_KILLPRIV | FUSE_POSIX_ACL |
1432 FUSE_ABORT_ERROR | FUSE_MAX_PAGES | FUSE_CACHE_SYMLINKS |
1433 FUSE_NO_OPENDIR_SUPPORT | FUSE_EXPLICIT_INVAL_DATA |
1434 FUSE_HANDLE_KILLPRIV_V2 | FUSE_SETXATTR_EXT | FUSE_INIT_EXT |
1435 FUSE_SECURITY_CTX | FUSE_CREATE_SUPP_GROUP |
1436 FUSE_HAS_EXPIRE_ONLY | FUSE_DIRECT_IO_ALLOW_MMAP |
1437 FUSE_NO_EXPORT_SUPPORT | FUSE_HAS_RESEND | FUSE_ALLOW_IDMAP;
1438#ifdef CONFIG_FUSE_DAX
1439 if (fm->fc->dax)
1440 flags |= FUSE_MAP_ALIGNMENT;
1441 if (fuse_is_inode_dax_mode(fm->fc->dax_mode))
1442 flags |= FUSE_HAS_INODE_DAX;
1443#endif
1444 if (fm->fc->auto_submounts)
1445 flags |= FUSE_SUBMOUNTS;
1446 if (IS_ENABLED(CONFIG_FUSE_PASSTHROUGH))
1447 flags |= FUSE_PASSTHROUGH;
1448
1449 ia->in.flags = flags;
1450 ia->in.flags2 = flags >> 32;
1451
1452 ia->args.opcode = FUSE_INIT;
1453 ia->args.in_numargs = 1;
1454 ia->args.in_args[0].size = sizeof(ia->in);
1455 ia->args.in_args[0].value = &ia->in;
1456 ia->args.out_numargs = 1;
1457 /* Variable length argument used for backward compatibility
1458 with interface version < 7.5. Rest of init_out is zeroed
1459 by do_get_request(), so a short reply is not a problem */
1460 ia->args.out_argvar = true;
1461 ia->args.out_args[0].size = sizeof(ia->out);
1462 ia->args.out_args[0].value = &ia->out;
1463 ia->args.force = true;
1464 ia->args.nocreds = true;
1465 ia->args.end = process_init_reply;
1466
1467 if (fuse_simple_background(fm, &ia->args, GFP_KERNEL) != 0)
1468 process_init_reply(fm, &ia->args, -ENOTCONN);
1469}
1470EXPORT_SYMBOL_GPL(fuse_send_init);
1471
1472void fuse_free_conn(struct fuse_conn *fc)
1473{
1474 WARN_ON(!list_empty(&fc->devices));
1475 kfree(fc);
1476}
1477EXPORT_SYMBOL_GPL(fuse_free_conn);
1478
1479static int fuse_bdi_init(struct fuse_conn *fc, struct super_block *sb)
1480{
1481 int err;
1482 char *suffix = "";
1483
1484 if (sb->s_bdev) {
1485 suffix = "-fuseblk";
1486 /*
1487 * sb->s_bdi points to blkdev's bdi however we want to redirect
1488 * it to our private bdi...
1489 */
1490 bdi_put(sb->s_bdi);
1491 sb->s_bdi = &noop_backing_dev_info;
1492 }
1493 err = super_setup_bdi_name(sb, "%u:%u%s", MAJOR(fc->dev),
1494 MINOR(fc->dev), suffix);
1495 if (err)
1496 return err;
1497
1498 /* fuse does it's own writeback accounting */
1499 sb->s_bdi->capabilities &= ~BDI_CAP_WRITEBACK_ACCT;
1500 sb->s_bdi->capabilities |= BDI_CAP_STRICTLIMIT;
1501
1502 /*
1503 * For a single fuse filesystem use max 1% of dirty +
1504 * writeback threshold.
1505 *
1506 * This gives about 1M of write buffer for memory maps on a
1507 * machine with 1G and 10% dirty_ratio, which should be more
1508 * than enough.
1509 *
1510 * Privileged users can raise it by writing to
1511 *
1512 * /sys/class/bdi/<bdi>/max_ratio
1513 */
1514 bdi_set_max_ratio(sb->s_bdi, 1);
1515
1516 return 0;
1517}
1518
1519struct fuse_dev *fuse_dev_alloc(void)
1520{
1521 struct fuse_dev *fud;
1522 struct list_head *pq;
1523
1524 fud = kzalloc(sizeof(struct fuse_dev), GFP_KERNEL);
1525 if (!fud)
1526 return NULL;
1527
1528 pq = kcalloc(FUSE_PQ_HASH_SIZE, sizeof(struct list_head), GFP_KERNEL);
1529 if (!pq) {
1530 kfree(fud);
1531 return NULL;
1532 }
1533
1534 fud->pq.processing = pq;
1535 fuse_pqueue_init(&fud->pq);
1536
1537 return fud;
1538}
1539EXPORT_SYMBOL_GPL(fuse_dev_alloc);
1540
1541void fuse_dev_install(struct fuse_dev *fud, struct fuse_conn *fc)
1542{
1543 fud->fc = fuse_conn_get(fc);
1544 spin_lock(&fc->lock);
1545 list_add_tail(&fud->entry, &fc->devices);
1546 spin_unlock(&fc->lock);
1547}
1548EXPORT_SYMBOL_GPL(fuse_dev_install);
1549
1550struct fuse_dev *fuse_dev_alloc_install(struct fuse_conn *fc)
1551{
1552 struct fuse_dev *fud;
1553
1554 fud = fuse_dev_alloc();
1555 if (!fud)
1556 return NULL;
1557
1558 fuse_dev_install(fud, fc);
1559 return fud;
1560}
1561EXPORT_SYMBOL_GPL(fuse_dev_alloc_install);
1562
1563void fuse_dev_free(struct fuse_dev *fud)
1564{
1565 struct fuse_conn *fc = fud->fc;
1566
1567 if (fc) {
1568 spin_lock(&fc->lock);
1569 list_del(&fud->entry);
1570 spin_unlock(&fc->lock);
1571
1572 fuse_conn_put(fc);
1573 }
1574 kfree(fud->pq.processing);
1575 kfree(fud);
1576}
1577EXPORT_SYMBOL_GPL(fuse_dev_free);
1578
1579static void fuse_fill_attr_from_inode(struct fuse_attr *attr,
1580 const struct fuse_inode *fi)
1581{
1582 struct timespec64 atime = inode_get_atime(&fi->inode);
1583 struct timespec64 mtime = inode_get_mtime(&fi->inode);
1584 struct timespec64 ctime = inode_get_ctime(&fi->inode);
1585
1586 *attr = (struct fuse_attr){
1587 .ino = fi->inode.i_ino,
1588 .size = fi->inode.i_size,
1589 .blocks = fi->inode.i_blocks,
1590 .atime = atime.tv_sec,
1591 .mtime = mtime.tv_sec,
1592 .ctime = ctime.tv_sec,
1593 .atimensec = atime.tv_nsec,
1594 .mtimensec = mtime.tv_nsec,
1595 .ctimensec = ctime.tv_nsec,
1596 .mode = fi->inode.i_mode,
1597 .nlink = fi->inode.i_nlink,
1598 .uid = __kuid_val(fi->inode.i_uid),
1599 .gid = __kgid_val(fi->inode.i_gid),
1600 .rdev = fi->inode.i_rdev,
1601 .blksize = 1u << fi->inode.i_blkbits,
1602 };
1603}
1604
1605static void fuse_sb_defaults(struct super_block *sb)
1606{
1607 sb->s_magic = FUSE_SUPER_MAGIC;
1608 sb->s_op = &fuse_super_operations;
1609 sb->s_xattr = fuse_xattr_handlers;
1610 sb->s_maxbytes = MAX_LFS_FILESIZE;
1611 sb->s_time_gran = 1;
1612 sb->s_export_op = &fuse_export_operations;
1613 sb->s_iflags |= SB_I_IMA_UNVERIFIABLE_SIGNATURE;
1614 sb->s_iflags |= SB_I_NOIDMAP;
1615 if (sb->s_user_ns != &init_user_ns)
1616 sb->s_iflags |= SB_I_UNTRUSTED_MOUNTER;
1617 sb->s_flags &= ~(SB_NOSEC | SB_I_VERSION);
1618}
1619
1620static int fuse_fill_super_submount(struct super_block *sb,
1621 struct fuse_inode *parent_fi)
1622{
1623 struct fuse_mount *fm = get_fuse_mount_super(sb);
1624 struct super_block *parent_sb = parent_fi->inode.i_sb;
1625 struct fuse_attr root_attr;
1626 struct inode *root;
1627 struct fuse_submount_lookup *sl;
1628 struct fuse_inode *fi;
1629
1630 fuse_sb_defaults(sb);
1631 fm->sb = sb;
1632
1633 WARN_ON(sb->s_bdi != &noop_backing_dev_info);
1634 sb->s_bdi = bdi_get(parent_sb->s_bdi);
1635
1636 sb->s_xattr = parent_sb->s_xattr;
1637 sb->s_export_op = parent_sb->s_export_op;
1638 sb->s_time_gran = parent_sb->s_time_gran;
1639 sb->s_blocksize = parent_sb->s_blocksize;
1640 sb->s_blocksize_bits = parent_sb->s_blocksize_bits;
1641 sb->s_subtype = kstrdup(parent_sb->s_subtype, GFP_KERNEL);
1642 if (parent_sb->s_subtype && !sb->s_subtype)
1643 return -ENOMEM;
1644
1645 fuse_fill_attr_from_inode(&root_attr, parent_fi);
1646 root = fuse_iget(sb, parent_fi->nodeid, 0, &root_attr, 0, 0,
1647 fuse_get_evict_ctr(fm->fc));
1648 /*
1649 * This inode is just a duplicate, so it is not looked up and
1650 * its nlookup should not be incremented. fuse_iget() does
1651 * that, though, so undo it here.
1652 */
1653 fi = get_fuse_inode(root);
1654 fi->nlookup--;
1655
1656 sb->s_d_op = &fuse_dentry_operations;
1657 sb->s_root = d_make_root(root);
1658 if (!sb->s_root)
1659 return -ENOMEM;
1660
1661 /*
1662 * Grab the parent's submount_lookup pointer and take a
1663 * reference on the shared nlookup from the parent. This is to
1664 * prevent the last forget for this nodeid from getting
1665 * triggered until all users have finished with it.
1666 */
1667 sl = parent_fi->submount_lookup;
1668 WARN_ON(!sl);
1669 if (sl) {
1670 refcount_inc(&sl->count);
1671 fi->submount_lookup = sl;
1672 }
1673
1674 return 0;
1675}
1676
1677/* Filesystem context private data holds the FUSE inode of the mount point */
1678static int fuse_get_tree_submount(struct fs_context *fsc)
1679{
1680 struct fuse_mount *fm;
1681 struct fuse_inode *mp_fi = fsc->fs_private;
1682 struct fuse_conn *fc = get_fuse_conn(&mp_fi->inode);
1683 struct super_block *sb;
1684 int err;
1685
1686 fm = kzalloc(sizeof(struct fuse_mount), GFP_KERNEL);
1687 if (!fm)
1688 return -ENOMEM;
1689
1690 fm->fc = fuse_conn_get(fc);
1691 fsc->s_fs_info = fm;
1692 sb = sget_fc(fsc, NULL, set_anon_super_fc);
1693 if (fsc->s_fs_info)
1694 fuse_mount_destroy(fm);
1695 if (IS_ERR(sb))
1696 return PTR_ERR(sb);
1697
1698 /* Initialize superblock, making @mp_fi its root */
1699 err = fuse_fill_super_submount(sb, mp_fi);
1700 if (err) {
1701 deactivate_locked_super(sb);
1702 return err;
1703 }
1704
1705 down_write(&fc->killsb);
1706 list_add_tail(&fm->fc_entry, &fc->mounts);
1707 up_write(&fc->killsb);
1708
1709 sb->s_flags |= SB_ACTIVE;
1710 fsc->root = dget(sb->s_root);
1711
1712 return 0;
1713}
1714
1715static const struct fs_context_operations fuse_context_submount_ops = {
1716 .get_tree = fuse_get_tree_submount,
1717};
1718
1719int fuse_init_fs_context_submount(struct fs_context *fsc)
1720{
1721 fsc->ops = &fuse_context_submount_ops;
1722 return 0;
1723}
1724EXPORT_SYMBOL_GPL(fuse_init_fs_context_submount);
1725
1726int fuse_fill_super_common(struct super_block *sb, struct fuse_fs_context *ctx)
1727{
1728 struct fuse_dev *fud = NULL;
1729 struct fuse_mount *fm = get_fuse_mount_super(sb);
1730 struct fuse_conn *fc = fm->fc;
1731 struct inode *root;
1732 struct dentry *root_dentry;
1733 int err;
1734
1735 err = -EINVAL;
1736 if (sb->s_flags & SB_MANDLOCK)
1737 goto err;
1738
1739 rcu_assign_pointer(fc->curr_bucket, fuse_sync_bucket_alloc());
1740 fuse_sb_defaults(sb);
1741
1742 if (ctx->is_bdev) {
1743#ifdef CONFIG_BLOCK
1744 err = -EINVAL;
1745 if (!sb_set_blocksize(sb, ctx->blksize))
1746 goto err;
1747#endif
1748 } else {
1749 sb->s_blocksize = PAGE_SIZE;
1750 sb->s_blocksize_bits = PAGE_SHIFT;
1751 }
1752
1753 sb->s_subtype = ctx->subtype;
1754 ctx->subtype = NULL;
1755 if (IS_ENABLED(CONFIG_FUSE_DAX)) {
1756 err = fuse_dax_conn_alloc(fc, ctx->dax_mode, ctx->dax_dev);
1757 if (err)
1758 goto err;
1759 }
1760
1761 if (ctx->fudptr) {
1762 err = -ENOMEM;
1763 fud = fuse_dev_alloc_install(fc);
1764 if (!fud)
1765 goto err_free_dax;
1766 }
1767
1768 fc->dev = sb->s_dev;
1769 fm->sb = sb;
1770 err = fuse_bdi_init(fc, sb);
1771 if (err)
1772 goto err_dev_free;
1773
1774 /* Handle umasking inside the fuse code */
1775 if (sb->s_flags & SB_POSIXACL)
1776 fc->dont_mask = 1;
1777 sb->s_flags |= SB_POSIXACL;
1778
1779 fc->default_permissions = ctx->default_permissions;
1780 fc->allow_other = ctx->allow_other;
1781 fc->user_id = ctx->user_id;
1782 fc->group_id = ctx->group_id;
1783 fc->legacy_opts_show = ctx->legacy_opts_show;
1784 fc->max_read = max_t(unsigned int, 4096, ctx->max_read);
1785 fc->destroy = ctx->destroy;
1786 fc->no_control = ctx->no_control;
1787 fc->no_force_umount = ctx->no_force_umount;
1788
1789 err = -ENOMEM;
1790 root = fuse_get_root_inode(sb, ctx->rootmode);
1791 sb->s_d_op = &fuse_root_dentry_operations;
1792 root_dentry = d_make_root(root);
1793 if (!root_dentry)
1794 goto err_dev_free;
1795 /* Root dentry doesn't have .d_revalidate */
1796 sb->s_d_op = &fuse_dentry_operations;
1797
1798 mutex_lock(&fuse_mutex);
1799 err = -EINVAL;
1800 if (ctx->fudptr && *ctx->fudptr)
1801 goto err_unlock;
1802
1803 err = fuse_ctl_add_conn(fc);
1804 if (err)
1805 goto err_unlock;
1806
1807 list_add_tail(&fc->entry, &fuse_conn_list);
1808 sb->s_root = root_dentry;
1809 if (ctx->fudptr)
1810 *ctx->fudptr = fud;
1811 mutex_unlock(&fuse_mutex);
1812 return 0;
1813
1814 err_unlock:
1815 mutex_unlock(&fuse_mutex);
1816 dput(root_dentry);
1817 err_dev_free:
1818 if (fud)
1819 fuse_dev_free(fud);
1820 err_free_dax:
1821 if (IS_ENABLED(CONFIG_FUSE_DAX))
1822 fuse_dax_conn_free(fc);
1823 err:
1824 return err;
1825}
1826EXPORT_SYMBOL_GPL(fuse_fill_super_common);
1827
1828static int fuse_fill_super(struct super_block *sb, struct fs_context *fsc)
1829{
1830 struct fuse_fs_context *ctx = fsc->fs_private;
1831 int err;
1832
1833 if (!ctx->file || !ctx->rootmode_present ||
1834 !ctx->user_id_present || !ctx->group_id_present)
1835 return -EINVAL;
1836
1837 /*
1838 * Require mount to happen from the same user namespace which
1839 * opened /dev/fuse to prevent potential attacks.
1840 */
1841 if ((ctx->file->f_op != &fuse_dev_operations) ||
1842 (ctx->file->f_cred->user_ns != sb->s_user_ns))
1843 return -EINVAL;
1844 ctx->fudptr = &ctx->file->private_data;
1845
1846 err = fuse_fill_super_common(sb, ctx);
1847 if (err)
1848 return err;
1849 /* file->private_data shall be visible on all CPUs after this */
1850 smp_mb();
1851 fuse_send_init(get_fuse_mount_super(sb));
1852 return 0;
1853}
1854
1855/*
1856 * This is the path where user supplied an already initialized fuse dev. In
1857 * this case never create a new super if the old one is gone.
1858 */
1859static int fuse_set_no_super(struct super_block *sb, struct fs_context *fsc)
1860{
1861 return -ENOTCONN;
1862}
1863
1864static int fuse_test_super(struct super_block *sb, struct fs_context *fsc)
1865{
1866
1867 return fsc->sget_key == get_fuse_conn_super(sb);
1868}
1869
1870static int fuse_get_tree(struct fs_context *fsc)
1871{
1872 struct fuse_fs_context *ctx = fsc->fs_private;
1873 struct fuse_dev *fud;
1874 struct fuse_conn *fc;
1875 struct fuse_mount *fm;
1876 struct super_block *sb;
1877 int err;
1878
1879 fc = kmalloc(sizeof(*fc), GFP_KERNEL);
1880 if (!fc)
1881 return -ENOMEM;
1882
1883 fm = kzalloc(sizeof(*fm), GFP_KERNEL);
1884 if (!fm) {
1885 kfree(fc);
1886 return -ENOMEM;
1887 }
1888
1889 fuse_conn_init(fc, fm, fsc->user_ns, &fuse_dev_fiq_ops, NULL);
1890 fc->release = fuse_free_conn;
1891
1892 fsc->s_fs_info = fm;
1893
1894 if (ctx->fd_present)
1895 ctx->file = fget(ctx->fd);
1896
1897 if (IS_ENABLED(CONFIG_BLOCK) && ctx->is_bdev) {
1898 err = get_tree_bdev(fsc, fuse_fill_super);
1899 goto out;
1900 }
1901 /*
1902 * While block dev mount can be initialized with a dummy device fd
1903 * (found by device name), normal fuse mounts can't
1904 */
1905 err = -EINVAL;
1906 if (!ctx->file)
1907 goto out;
1908
1909 /*
1910 * Allow creating a fuse mount with an already initialized fuse
1911 * connection
1912 */
1913 fud = READ_ONCE(ctx->file->private_data);
1914 if (ctx->file->f_op == &fuse_dev_operations && fud) {
1915 fsc->sget_key = fud->fc;
1916 sb = sget_fc(fsc, fuse_test_super, fuse_set_no_super);
1917 err = PTR_ERR_OR_ZERO(sb);
1918 if (!IS_ERR(sb))
1919 fsc->root = dget(sb->s_root);
1920 } else {
1921 err = get_tree_nodev(fsc, fuse_fill_super);
1922 }
1923out:
1924 if (fsc->s_fs_info)
1925 fuse_mount_destroy(fm);
1926 if (ctx->file)
1927 fput(ctx->file);
1928 return err;
1929}
1930
1931static const struct fs_context_operations fuse_context_ops = {
1932 .free = fuse_free_fsc,
1933 .parse_param = fuse_parse_param,
1934 .reconfigure = fuse_reconfigure,
1935 .get_tree = fuse_get_tree,
1936};
1937
1938/*
1939 * Set up the filesystem mount context.
1940 */
1941static int fuse_init_fs_context(struct fs_context *fsc)
1942{
1943 struct fuse_fs_context *ctx;
1944
1945 ctx = kzalloc(sizeof(struct fuse_fs_context), GFP_KERNEL);
1946 if (!ctx)
1947 return -ENOMEM;
1948
1949 ctx->max_read = ~0;
1950 ctx->blksize = FUSE_DEFAULT_BLKSIZE;
1951 ctx->legacy_opts_show = true;
1952
1953#ifdef CONFIG_BLOCK
1954 if (fsc->fs_type == &fuseblk_fs_type) {
1955 ctx->is_bdev = true;
1956 ctx->destroy = true;
1957 }
1958#endif
1959
1960 fsc->fs_private = ctx;
1961 fsc->ops = &fuse_context_ops;
1962 return 0;
1963}
1964
1965bool fuse_mount_remove(struct fuse_mount *fm)
1966{
1967 struct fuse_conn *fc = fm->fc;
1968 bool last = false;
1969
1970 down_write(&fc->killsb);
1971 list_del_init(&fm->fc_entry);
1972 if (list_empty(&fc->mounts))
1973 last = true;
1974 up_write(&fc->killsb);
1975
1976 return last;
1977}
1978EXPORT_SYMBOL_GPL(fuse_mount_remove);
1979
1980void fuse_conn_destroy(struct fuse_mount *fm)
1981{
1982 struct fuse_conn *fc = fm->fc;
1983
1984 if (fc->destroy)
1985 fuse_send_destroy(fm);
1986
1987 fuse_abort_conn(fc);
1988 fuse_wait_aborted(fc);
1989
1990 if (!list_empty(&fc->entry)) {
1991 mutex_lock(&fuse_mutex);
1992 list_del(&fc->entry);
1993 fuse_ctl_remove_conn(fc);
1994 mutex_unlock(&fuse_mutex);
1995 }
1996}
1997EXPORT_SYMBOL_GPL(fuse_conn_destroy);
1998
1999static void fuse_sb_destroy(struct super_block *sb)
2000{
2001 struct fuse_mount *fm = get_fuse_mount_super(sb);
2002 bool last;
2003
2004 if (sb->s_root) {
2005 last = fuse_mount_remove(fm);
2006 if (last)
2007 fuse_conn_destroy(fm);
2008 }
2009}
2010
2011void fuse_mount_destroy(struct fuse_mount *fm)
2012{
2013 fuse_conn_put(fm->fc);
2014 kfree_rcu(fm, rcu);
2015}
2016EXPORT_SYMBOL(fuse_mount_destroy);
2017
2018static void fuse_kill_sb_anon(struct super_block *sb)
2019{
2020 fuse_sb_destroy(sb);
2021 kill_anon_super(sb);
2022 fuse_mount_destroy(get_fuse_mount_super(sb));
2023}
2024
2025static struct file_system_type fuse_fs_type = {
2026 .owner = THIS_MODULE,
2027 .name = "fuse",
2028 .fs_flags = FS_HAS_SUBTYPE | FS_USERNS_MOUNT | FS_ALLOW_IDMAP,
2029 .init_fs_context = fuse_init_fs_context,
2030 .parameters = fuse_fs_parameters,
2031 .kill_sb = fuse_kill_sb_anon,
2032};
2033MODULE_ALIAS_FS("fuse");
2034
2035#ifdef CONFIG_BLOCK
2036static void fuse_kill_sb_blk(struct super_block *sb)
2037{
2038 fuse_sb_destroy(sb);
2039 kill_block_super(sb);
2040 fuse_mount_destroy(get_fuse_mount_super(sb));
2041}
2042
2043static struct file_system_type fuseblk_fs_type = {
2044 .owner = THIS_MODULE,
2045 .name = "fuseblk",
2046 .init_fs_context = fuse_init_fs_context,
2047 .parameters = fuse_fs_parameters,
2048 .kill_sb = fuse_kill_sb_blk,
2049 .fs_flags = FS_REQUIRES_DEV | FS_HAS_SUBTYPE | FS_ALLOW_IDMAP,
2050};
2051MODULE_ALIAS_FS("fuseblk");
2052
2053static inline int register_fuseblk(void)
2054{
2055 return register_filesystem(&fuseblk_fs_type);
2056}
2057
2058static inline void unregister_fuseblk(void)
2059{
2060 unregister_filesystem(&fuseblk_fs_type);
2061}
2062#else
2063static inline int register_fuseblk(void)
2064{
2065 return 0;
2066}
2067
2068static inline void unregister_fuseblk(void)
2069{
2070}
2071#endif
2072
2073static void fuse_inode_init_once(void *foo)
2074{
2075 struct inode *inode = foo;
2076
2077 inode_init_once(inode);
2078}
2079
2080static int __init fuse_fs_init(void)
2081{
2082 int err;
2083
2084 fuse_inode_cachep = kmem_cache_create("fuse_inode",
2085 sizeof(struct fuse_inode), 0,
2086 SLAB_HWCACHE_ALIGN|SLAB_ACCOUNT|SLAB_RECLAIM_ACCOUNT,
2087 fuse_inode_init_once);
2088 err = -ENOMEM;
2089 if (!fuse_inode_cachep)
2090 goto out;
2091
2092 err = register_fuseblk();
2093 if (err)
2094 goto out2;
2095
2096 err = register_filesystem(&fuse_fs_type);
2097 if (err)
2098 goto out3;
2099
2100 err = fuse_sysctl_register();
2101 if (err)
2102 goto out4;
2103
2104 return 0;
2105
2106 out4:
2107 unregister_filesystem(&fuse_fs_type);
2108 out3:
2109 unregister_fuseblk();
2110 out2:
2111 kmem_cache_destroy(fuse_inode_cachep);
2112 out:
2113 return err;
2114}
2115
2116static void fuse_fs_cleanup(void)
2117{
2118 fuse_sysctl_unregister();
2119 unregister_filesystem(&fuse_fs_type);
2120 unregister_fuseblk();
2121
2122 /*
2123 * Make sure all delayed rcu free inodes are flushed before we
2124 * destroy cache.
2125 */
2126 rcu_barrier();
2127 kmem_cache_destroy(fuse_inode_cachep);
2128}
2129
2130static struct kobject *fuse_kobj;
2131
2132static int fuse_sysfs_init(void)
2133{
2134 int err;
2135
2136 fuse_kobj = kobject_create_and_add("fuse", fs_kobj);
2137 if (!fuse_kobj) {
2138 err = -ENOMEM;
2139 goto out_err;
2140 }
2141
2142 err = sysfs_create_mount_point(fuse_kobj, "connections");
2143 if (err)
2144 goto out_fuse_unregister;
2145
2146 return 0;
2147
2148 out_fuse_unregister:
2149 kobject_put(fuse_kobj);
2150 out_err:
2151 return err;
2152}
2153
2154static void fuse_sysfs_cleanup(void)
2155{
2156 sysfs_remove_mount_point(fuse_kobj, "connections");
2157 kobject_put(fuse_kobj);
2158}
2159
2160static int __init fuse_init(void)
2161{
2162 int res;
2163
2164 pr_info("init (API version %i.%i)\n",
2165 FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
2166
2167 INIT_LIST_HEAD(&fuse_conn_list);
2168 res = fuse_fs_init();
2169 if (res)
2170 goto err;
2171
2172 res = fuse_dev_init();
2173 if (res)
2174 goto err_fs_cleanup;
2175
2176 res = fuse_sysfs_init();
2177 if (res)
2178 goto err_dev_cleanup;
2179
2180 res = fuse_ctl_init();
2181 if (res)
2182 goto err_sysfs_cleanup;
2183
2184 sanitize_global_limit(&max_user_bgreq);
2185 sanitize_global_limit(&max_user_congthresh);
2186
2187 return 0;
2188
2189 err_sysfs_cleanup:
2190 fuse_sysfs_cleanup();
2191 err_dev_cleanup:
2192 fuse_dev_cleanup();
2193 err_fs_cleanup:
2194 fuse_fs_cleanup();
2195 err:
2196 return res;
2197}
2198
2199static void __exit fuse_exit(void)
2200{
2201 pr_debug("exit\n");
2202
2203 fuse_ctl_cleanup();
2204 fuse_sysfs_cleanup();
2205 fuse_fs_cleanup();
2206 fuse_dev_cleanup();
2207}
2208
2209module_init(fuse_init);
2210module_exit(fuse_exit);