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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/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 max_user_bgreq;
39module_param_call(max_user_bgreq, set_global_limit, param_get_uint,
40 &max_user_bgreq, 0644);
41__MODULE_PARM_TYPE(max_user_bgreq, "uint");
42MODULE_PARM_DESC(max_user_bgreq,
43 "Global limit for the maximum number of backgrounded requests an "
44 "unprivileged user can set");
45
46unsigned max_user_congthresh;
47module_param_call(max_user_congthresh, set_global_limit, param_get_uint,
48 &max_user_congthresh, 0644);
49__MODULE_PARM_TYPE(max_user_congthresh, "uint");
50MODULE_PARM_DESC(max_user_congthresh,
51 "Global limit for the maximum congestion threshold an "
52 "unprivileged user can set");
53
54#define FUSE_DEFAULT_BLKSIZE 512
55
56/** Maximum number of outstanding background requests */
57#define FUSE_DEFAULT_MAX_BACKGROUND 12
58
59/** Congestion starts at 75% of maximum */
60#define FUSE_DEFAULT_CONGESTION_THRESHOLD (FUSE_DEFAULT_MAX_BACKGROUND * 3 / 4)
61
62#ifdef CONFIG_BLOCK
63static struct file_system_type fuseblk_fs_type;
64#endif
65
66struct fuse_forget_link *fuse_alloc_forget(void)
67{
68 return kzalloc(sizeof(struct fuse_forget_link), GFP_KERNEL_ACCOUNT);
69}
70
71static struct inode *fuse_alloc_inode(struct super_block *sb)
72{
73 struct fuse_inode *fi;
74
75 fi = alloc_inode_sb(sb, fuse_inode_cachep, GFP_KERNEL);
76 if (!fi)
77 return NULL;
78
79 fi->i_time = 0;
80 fi->inval_mask = 0;
81 fi->nodeid = 0;
82 fi->nlookup = 0;
83 fi->attr_version = 0;
84 fi->orig_ino = 0;
85 fi->state = 0;
86 mutex_init(&fi->mutex);
87 spin_lock_init(&fi->lock);
88 fi->forget = fuse_alloc_forget();
89 if (!fi->forget)
90 goto out_free;
91
92 if (IS_ENABLED(CONFIG_FUSE_DAX) && !fuse_dax_inode_alloc(sb, fi))
93 goto out_free_forget;
94
95 return &fi->inode;
96
97out_free_forget:
98 kfree(fi->forget);
99out_free:
100 kmem_cache_free(fuse_inode_cachep, fi);
101 return NULL;
102}
103
104static void fuse_free_inode(struct inode *inode)
105{
106 struct fuse_inode *fi = get_fuse_inode(inode);
107
108 mutex_destroy(&fi->mutex);
109 kfree(fi->forget);
110#ifdef CONFIG_FUSE_DAX
111 kfree(fi->dax);
112#endif
113 kmem_cache_free(fuse_inode_cachep, fi);
114}
115
116static void fuse_evict_inode(struct inode *inode)
117{
118 struct fuse_inode *fi = get_fuse_inode(inode);
119
120 /* Will write inode on close/munmap and in all other dirtiers */
121 WARN_ON(inode->i_state & I_DIRTY_INODE);
122
123 truncate_inode_pages_final(&inode->i_data);
124 clear_inode(inode);
125 if (inode->i_sb->s_flags & SB_ACTIVE) {
126 struct fuse_conn *fc = get_fuse_conn(inode);
127
128 if (FUSE_IS_DAX(inode))
129 fuse_dax_inode_cleanup(inode);
130 if (fi->nlookup) {
131 fuse_queue_forget(fc, fi->forget, fi->nodeid,
132 fi->nlookup);
133 fi->forget = NULL;
134 }
135 }
136 if (S_ISREG(inode->i_mode) && !fuse_is_bad(inode)) {
137 WARN_ON(!list_empty(&fi->write_files));
138 WARN_ON(!list_empty(&fi->queued_writes));
139 }
140}
141
142static int fuse_reconfigure(struct fs_context *fsc)
143{
144 struct super_block *sb = fsc->root->d_sb;
145
146 sync_filesystem(sb);
147 if (fsc->sb_flags & SB_MANDLOCK)
148 return -EINVAL;
149
150 return 0;
151}
152
153/*
154 * ino_t is 32-bits on 32-bit arch. We have to squash the 64-bit value down
155 * so that it will fit.
156 */
157static ino_t fuse_squash_ino(u64 ino64)
158{
159 ino_t ino = (ino_t) ino64;
160 if (sizeof(ino_t) < sizeof(u64))
161 ino ^= ino64 >> (sizeof(u64) - sizeof(ino_t)) * 8;
162 return ino;
163}
164
165void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
166 u64 attr_valid, u32 cache_mask)
167{
168 struct fuse_conn *fc = get_fuse_conn(inode);
169 struct fuse_inode *fi = get_fuse_inode(inode);
170
171 lockdep_assert_held(&fi->lock);
172
173 fi->attr_version = atomic64_inc_return(&fc->attr_version);
174 fi->i_time = attr_valid;
175 WRITE_ONCE(fi->inval_mask, 0);
176
177 inode->i_ino = fuse_squash_ino(attr->ino);
178 inode->i_mode = (inode->i_mode & S_IFMT) | (attr->mode & 07777);
179 set_nlink(inode, attr->nlink);
180 inode->i_uid = make_kuid(fc->user_ns, attr->uid);
181 inode->i_gid = make_kgid(fc->user_ns, attr->gid);
182 inode->i_blocks = attr->blocks;
183
184 /* Sanitize nsecs */
185 attr->atimensec = min_t(u32, attr->atimensec, NSEC_PER_SEC - 1);
186 attr->mtimensec = min_t(u32, attr->mtimensec, NSEC_PER_SEC - 1);
187 attr->ctimensec = min_t(u32, attr->ctimensec, NSEC_PER_SEC - 1);
188
189 inode->i_atime.tv_sec = attr->atime;
190 inode->i_atime.tv_nsec = attr->atimensec;
191 /* mtime from server may be stale due to local buffered write */
192 if (!(cache_mask & STATX_MTIME)) {
193 inode->i_mtime.tv_sec = attr->mtime;
194 inode->i_mtime.tv_nsec = attr->mtimensec;
195 }
196 if (!(cache_mask & STATX_CTIME)) {
197 inode->i_ctime.tv_sec = attr->ctime;
198 inode->i_ctime.tv_nsec = attr->ctimensec;
199 }
200
201 if (attr->blksize != 0)
202 inode->i_blkbits = ilog2(attr->blksize);
203 else
204 inode->i_blkbits = inode->i_sb->s_blocksize_bits;
205
206 /*
207 * Don't set the sticky bit in i_mode, unless we want the VFS
208 * to check permissions. This prevents failures due to the
209 * check in may_delete().
210 */
211 fi->orig_i_mode = inode->i_mode;
212 if (!fc->default_permissions)
213 inode->i_mode &= ~S_ISVTX;
214
215 fi->orig_ino = attr->ino;
216
217 /*
218 * We are refreshing inode data and it is possible that another
219 * client set suid/sgid or security.capability xattr. So clear
220 * S_NOSEC. Ideally, we could have cleared it only if suid/sgid
221 * was set or if security.capability xattr was set. But we don't
222 * know if security.capability has been set or not. So clear it
223 * anyway. Its less efficient but should be safe.
224 */
225 inode->i_flags &= ~S_NOSEC;
226}
227
228u32 fuse_get_cache_mask(struct inode *inode)
229{
230 struct fuse_conn *fc = get_fuse_conn(inode);
231
232 if (!fc->writeback_cache || !S_ISREG(inode->i_mode))
233 return 0;
234
235 return STATX_MTIME | STATX_CTIME | STATX_SIZE;
236}
237
238void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
239 u64 attr_valid, u64 attr_version)
240{
241 struct fuse_conn *fc = get_fuse_conn(inode);
242 struct fuse_inode *fi = get_fuse_inode(inode);
243 u32 cache_mask;
244 loff_t oldsize;
245 struct timespec64 old_mtime;
246
247 spin_lock(&fi->lock);
248 /*
249 * In case of writeback_cache enabled, writes update mtime, ctime and
250 * may update i_size. In these cases trust the cached value in the
251 * inode.
252 */
253 cache_mask = fuse_get_cache_mask(inode);
254 if (cache_mask & STATX_SIZE)
255 attr->size = i_size_read(inode);
256
257 if (cache_mask & STATX_MTIME) {
258 attr->mtime = inode->i_mtime.tv_sec;
259 attr->mtimensec = inode->i_mtime.tv_nsec;
260 }
261 if (cache_mask & STATX_CTIME) {
262 attr->ctime = inode->i_ctime.tv_sec;
263 attr->ctimensec = inode->i_ctime.tv_nsec;
264 }
265
266 if ((attr_version != 0 && fi->attr_version > attr_version) ||
267 test_bit(FUSE_I_SIZE_UNSTABLE, &fi->state)) {
268 spin_unlock(&fi->lock);
269 return;
270 }
271
272 old_mtime = inode->i_mtime;
273 fuse_change_attributes_common(inode, attr, attr_valid, cache_mask);
274
275 oldsize = inode->i_size;
276 /*
277 * In case of writeback_cache enabled, the cached writes beyond EOF
278 * extend local i_size without keeping userspace server in sync. So,
279 * attr->size coming from server can be stale. We cannot trust it.
280 */
281 if (!(cache_mask & STATX_SIZE))
282 i_size_write(inode, attr->size);
283 spin_unlock(&fi->lock);
284
285 if (!cache_mask && S_ISREG(inode->i_mode)) {
286 bool inval = false;
287
288 if (oldsize != attr->size) {
289 truncate_pagecache(inode, attr->size);
290 if (!fc->explicit_inval_data)
291 inval = true;
292 } else if (fc->auto_inval_data) {
293 struct timespec64 new_mtime = {
294 .tv_sec = attr->mtime,
295 .tv_nsec = attr->mtimensec,
296 };
297
298 /*
299 * Auto inval mode also checks and invalidates if mtime
300 * has changed.
301 */
302 if (!timespec64_equal(&old_mtime, &new_mtime))
303 inval = true;
304 }
305
306 if (inval)
307 invalidate_inode_pages2(inode->i_mapping);
308 }
309
310 if (IS_ENABLED(CONFIG_FUSE_DAX))
311 fuse_dax_dontcache(inode, attr->flags);
312}
313
314static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr,
315 struct fuse_conn *fc)
316{
317 inode->i_mode = attr->mode & S_IFMT;
318 inode->i_size = attr->size;
319 inode->i_mtime.tv_sec = attr->mtime;
320 inode->i_mtime.tv_nsec = attr->mtimensec;
321 inode->i_ctime.tv_sec = attr->ctime;
322 inode->i_ctime.tv_nsec = attr->ctimensec;
323 if (S_ISREG(inode->i_mode)) {
324 fuse_init_common(inode);
325 fuse_init_file_inode(inode, attr->flags);
326 } else if (S_ISDIR(inode->i_mode))
327 fuse_init_dir(inode);
328 else if (S_ISLNK(inode->i_mode))
329 fuse_init_symlink(inode);
330 else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
331 S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
332 fuse_init_common(inode);
333 init_special_inode(inode, inode->i_mode,
334 new_decode_dev(attr->rdev));
335 } else
336 BUG();
337 /*
338 * Ensure that we don't cache acls for daemons without FUSE_POSIX_ACL
339 * so they see the exact same behavior as before.
340 */
341 if (!fc->posix_acl)
342 inode->i_acl = inode->i_default_acl = ACL_DONT_CACHE;
343}
344
345static int fuse_inode_eq(struct inode *inode, void *_nodeidp)
346{
347 u64 nodeid = *(u64 *) _nodeidp;
348 if (get_node_id(inode) == nodeid)
349 return 1;
350 else
351 return 0;
352}
353
354static int fuse_inode_set(struct inode *inode, void *_nodeidp)
355{
356 u64 nodeid = *(u64 *) _nodeidp;
357 get_fuse_inode(inode)->nodeid = nodeid;
358 return 0;
359}
360
361struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
362 int generation, struct fuse_attr *attr,
363 u64 attr_valid, u64 attr_version)
364{
365 struct inode *inode;
366 struct fuse_inode *fi;
367 struct fuse_conn *fc = get_fuse_conn_super(sb);
368
369 /*
370 * Auto mount points get their node id from the submount root, which is
371 * not a unique identifier within this filesystem.
372 *
373 * To avoid conflicts, do not place submount points into the inode hash
374 * table.
375 */
376 if (fc->auto_submounts && (attr->flags & FUSE_ATTR_SUBMOUNT) &&
377 S_ISDIR(attr->mode)) {
378 inode = new_inode(sb);
379 if (!inode)
380 return NULL;
381
382 fuse_init_inode(inode, attr, fc);
383 get_fuse_inode(inode)->nodeid = nodeid;
384 inode->i_flags |= S_AUTOMOUNT;
385 goto done;
386 }
387
388retry:
389 inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid);
390 if (!inode)
391 return NULL;
392
393 if ((inode->i_state & I_NEW)) {
394 inode->i_flags |= S_NOATIME;
395 if (!fc->writeback_cache || !S_ISREG(attr->mode))
396 inode->i_flags |= S_NOCMTIME;
397 inode->i_generation = generation;
398 fuse_init_inode(inode, attr, fc);
399 unlock_new_inode(inode);
400 } else if (fuse_stale_inode(inode, generation, attr)) {
401 /* nodeid was reused, any I/O on the old inode should fail */
402 fuse_make_bad(inode);
403 iput(inode);
404 goto retry;
405 }
406done:
407 fi = get_fuse_inode(inode);
408 spin_lock(&fi->lock);
409 fi->nlookup++;
410 spin_unlock(&fi->lock);
411 fuse_change_attributes(inode, attr, attr_valid, attr_version);
412
413 return inode;
414}
415
416struct inode *fuse_ilookup(struct fuse_conn *fc, u64 nodeid,
417 struct fuse_mount **fm)
418{
419 struct fuse_mount *fm_iter;
420 struct inode *inode;
421
422 WARN_ON(!rwsem_is_locked(&fc->killsb));
423 list_for_each_entry(fm_iter, &fc->mounts, fc_entry) {
424 if (!fm_iter->sb)
425 continue;
426
427 inode = ilookup5(fm_iter->sb, nodeid, fuse_inode_eq, &nodeid);
428 if (inode) {
429 if (fm)
430 *fm = fm_iter;
431 return inode;
432 }
433 }
434
435 return NULL;
436}
437
438int fuse_reverse_inval_inode(struct fuse_conn *fc, u64 nodeid,
439 loff_t offset, loff_t len)
440{
441 struct fuse_inode *fi;
442 struct inode *inode;
443 pgoff_t pg_start;
444 pgoff_t pg_end;
445
446 inode = fuse_ilookup(fc, nodeid, NULL);
447 if (!inode)
448 return -ENOENT;
449
450 fi = get_fuse_inode(inode);
451 spin_lock(&fi->lock);
452 fi->attr_version = atomic64_inc_return(&fc->attr_version);
453 spin_unlock(&fi->lock);
454
455 fuse_invalidate_attr(inode);
456 forget_all_cached_acls(inode);
457 if (offset >= 0) {
458 pg_start = offset >> PAGE_SHIFT;
459 if (len <= 0)
460 pg_end = -1;
461 else
462 pg_end = (offset + len - 1) >> PAGE_SHIFT;
463 invalidate_inode_pages2_range(inode->i_mapping,
464 pg_start, pg_end);
465 }
466 iput(inode);
467 return 0;
468}
469
470bool fuse_lock_inode(struct inode *inode)
471{
472 bool locked = false;
473
474 if (!get_fuse_conn(inode)->parallel_dirops) {
475 mutex_lock(&get_fuse_inode(inode)->mutex);
476 locked = true;
477 }
478
479 return locked;
480}
481
482void fuse_unlock_inode(struct inode *inode, bool locked)
483{
484 if (locked)
485 mutex_unlock(&get_fuse_inode(inode)->mutex);
486}
487
488static void fuse_umount_begin(struct super_block *sb)
489{
490 struct fuse_conn *fc = get_fuse_conn_super(sb);
491
492 if (fc->no_force_umount)
493 return;
494
495 fuse_abort_conn(fc);
496
497 // Only retire block-device-based superblocks.
498 if (sb->s_bdev != NULL)
499 retire_super(sb);
500}
501
502static void fuse_send_destroy(struct fuse_mount *fm)
503{
504 if (fm->fc->conn_init) {
505 FUSE_ARGS(args);
506
507 args.opcode = FUSE_DESTROY;
508 args.force = true;
509 args.nocreds = true;
510 fuse_simple_request(fm, &args);
511 }
512}
513
514static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
515{
516 stbuf->f_type = FUSE_SUPER_MAGIC;
517 stbuf->f_bsize = attr->bsize;
518 stbuf->f_frsize = attr->frsize;
519 stbuf->f_blocks = attr->blocks;
520 stbuf->f_bfree = attr->bfree;
521 stbuf->f_bavail = attr->bavail;
522 stbuf->f_files = attr->files;
523 stbuf->f_ffree = attr->ffree;
524 stbuf->f_namelen = attr->namelen;
525 /* fsid is left zero */
526}
527
528static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf)
529{
530 struct super_block *sb = dentry->d_sb;
531 struct fuse_mount *fm = get_fuse_mount_super(sb);
532 FUSE_ARGS(args);
533 struct fuse_statfs_out outarg;
534 int err;
535
536 if (!fuse_allow_current_process(fm->fc)) {
537 buf->f_type = FUSE_SUPER_MAGIC;
538 return 0;
539 }
540
541 memset(&outarg, 0, sizeof(outarg));
542 args.in_numargs = 0;
543 args.opcode = FUSE_STATFS;
544 args.nodeid = get_node_id(d_inode(dentry));
545 args.out_numargs = 1;
546 args.out_args[0].size = sizeof(outarg);
547 args.out_args[0].value = &outarg;
548 err = fuse_simple_request(fm, &args);
549 if (!err)
550 convert_fuse_statfs(buf, &outarg.st);
551 return err;
552}
553
554static struct fuse_sync_bucket *fuse_sync_bucket_alloc(void)
555{
556 struct fuse_sync_bucket *bucket;
557
558 bucket = kzalloc(sizeof(*bucket), GFP_KERNEL | __GFP_NOFAIL);
559 if (bucket) {
560 init_waitqueue_head(&bucket->waitq);
561 /* Initial active count */
562 atomic_set(&bucket->count, 1);
563 }
564 return bucket;
565}
566
567static void fuse_sync_fs_writes(struct fuse_conn *fc)
568{
569 struct fuse_sync_bucket *bucket, *new_bucket;
570 int count;
571
572 new_bucket = fuse_sync_bucket_alloc();
573 spin_lock(&fc->lock);
574 bucket = rcu_dereference_protected(fc->curr_bucket, 1);
575 count = atomic_read(&bucket->count);
576 WARN_ON(count < 1);
577 /* No outstanding writes? */
578 if (count == 1) {
579 spin_unlock(&fc->lock);
580 kfree(new_bucket);
581 return;
582 }
583
584 /*
585 * Completion of new bucket depends on completion of this bucket, so add
586 * one more count.
587 */
588 atomic_inc(&new_bucket->count);
589 rcu_assign_pointer(fc->curr_bucket, new_bucket);
590 spin_unlock(&fc->lock);
591 /*
592 * Drop initial active count. At this point if all writes in this and
593 * ancestor buckets complete, the count will go to zero and this task
594 * will be woken up.
595 */
596 atomic_dec(&bucket->count);
597
598 wait_event(bucket->waitq, atomic_read(&bucket->count) == 0);
599
600 /* Drop temp count on descendant bucket */
601 fuse_sync_bucket_dec(new_bucket);
602 kfree_rcu(bucket, rcu);
603}
604
605static int fuse_sync_fs(struct super_block *sb, int wait)
606{
607 struct fuse_mount *fm = get_fuse_mount_super(sb);
608 struct fuse_conn *fc = fm->fc;
609 struct fuse_syncfs_in inarg;
610 FUSE_ARGS(args);
611 int err;
612
613 /*
614 * Userspace cannot handle the wait == 0 case. Avoid a
615 * gratuitous roundtrip.
616 */
617 if (!wait)
618 return 0;
619
620 /* The filesystem is being unmounted. Nothing to do. */
621 if (!sb->s_root)
622 return 0;
623
624 if (!fc->sync_fs)
625 return 0;
626
627 fuse_sync_fs_writes(fc);
628
629 memset(&inarg, 0, sizeof(inarg));
630 args.in_numargs = 1;
631 args.in_args[0].size = sizeof(inarg);
632 args.in_args[0].value = &inarg;
633 args.opcode = FUSE_SYNCFS;
634 args.nodeid = get_node_id(sb->s_root->d_inode);
635 args.out_numargs = 0;
636
637 err = fuse_simple_request(fm, &args);
638 if (err == -ENOSYS) {
639 fc->sync_fs = 0;
640 err = 0;
641 }
642
643 return err;
644}
645
646enum {
647 OPT_SOURCE,
648 OPT_SUBTYPE,
649 OPT_FD,
650 OPT_ROOTMODE,
651 OPT_USER_ID,
652 OPT_GROUP_ID,
653 OPT_DEFAULT_PERMISSIONS,
654 OPT_ALLOW_OTHER,
655 OPT_MAX_READ,
656 OPT_BLKSIZE,
657 OPT_ERR
658};
659
660static const struct fs_parameter_spec fuse_fs_parameters[] = {
661 fsparam_string ("source", OPT_SOURCE),
662 fsparam_u32 ("fd", OPT_FD),
663 fsparam_u32oct ("rootmode", OPT_ROOTMODE),
664 fsparam_u32 ("user_id", OPT_USER_ID),
665 fsparam_u32 ("group_id", OPT_GROUP_ID),
666 fsparam_flag ("default_permissions", OPT_DEFAULT_PERMISSIONS),
667 fsparam_flag ("allow_other", OPT_ALLOW_OTHER),
668 fsparam_u32 ("max_read", OPT_MAX_READ),
669 fsparam_u32 ("blksize", OPT_BLKSIZE),
670 fsparam_string ("subtype", OPT_SUBTYPE),
671 {}
672};
673
674static int fuse_parse_param(struct fs_context *fsc, struct fs_parameter *param)
675{
676 struct fs_parse_result result;
677 struct fuse_fs_context *ctx = fsc->fs_private;
678 int opt;
679
680 if (fsc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
681 /*
682 * Ignore options coming from mount(MS_REMOUNT) for backward
683 * compatibility.
684 */
685 if (fsc->oldapi)
686 return 0;
687
688 return invalfc(fsc, "No changes allowed in reconfigure");
689 }
690
691 opt = fs_parse(fsc, fuse_fs_parameters, param, &result);
692 if (opt < 0)
693 return opt;
694
695 switch (opt) {
696 case OPT_SOURCE:
697 if (fsc->source)
698 return invalfc(fsc, "Multiple sources specified");
699 fsc->source = param->string;
700 param->string = NULL;
701 break;
702
703 case OPT_SUBTYPE:
704 if (ctx->subtype)
705 return invalfc(fsc, "Multiple subtypes specified");
706 ctx->subtype = param->string;
707 param->string = NULL;
708 return 0;
709
710 case OPT_FD:
711 ctx->fd = result.uint_32;
712 ctx->fd_present = true;
713 break;
714
715 case OPT_ROOTMODE:
716 if (!fuse_valid_type(result.uint_32))
717 return invalfc(fsc, "Invalid rootmode");
718 ctx->rootmode = result.uint_32;
719 ctx->rootmode_present = true;
720 break;
721
722 case OPT_USER_ID:
723 ctx->user_id = make_kuid(fsc->user_ns, result.uint_32);
724 if (!uid_valid(ctx->user_id))
725 return invalfc(fsc, "Invalid user_id");
726 ctx->user_id_present = true;
727 break;
728
729 case OPT_GROUP_ID:
730 ctx->group_id = make_kgid(fsc->user_ns, result.uint_32);
731 if (!gid_valid(ctx->group_id))
732 return invalfc(fsc, "Invalid group_id");
733 ctx->group_id_present = true;
734 break;
735
736 case OPT_DEFAULT_PERMISSIONS:
737 ctx->default_permissions = true;
738 break;
739
740 case OPT_ALLOW_OTHER:
741 ctx->allow_other = true;
742 break;
743
744 case OPT_MAX_READ:
745 ctx->max_read = result.uint_32;
746 break;
747
748 case OPT_BLKSIZE:
749 if (!ctx->is_bdev)
750 return invalfc(fsc, "blksize only supported for fuseblk");
751 ctx->blksize = result.uint_32;
752 break;
753
754 default:
755 return -EINVAL;
756 }
757
758 return 0;
759}
760
761static void fuse_free_fsc(struct fs_context *fsc)
762{
763 struct fuse_fs_context *ctx = fsc->fs_private;
764
765 if (ctx) {
766 kfree(ctx->subtype);
767 kfree(ctx);
768 }
769}
770
771static int fuse_show_options(struct seq_file *m, struct dentry *root)
772{
773 struct super_block *sb = root->d_sb;
774 struct fuse_conn *fc = get_fuse_conn_super(sb);
775
776 if (fc->legacy_opts_show) {
777 seq_printf(m, ",user_id=%u",
778 from_kuid_munged(fc->user_ns, fc->user_id));
779 seq_printf(m, ",group_id=%u",
780 from_kgid_munged(fc->user_ns, fc->group_id));
781 if (fc->default_permissions)
782 seq_puts(m, ",default_permissions");
783 if (fc->allow_other)
784 seq_puts(m, ",allow_other");
785 if (fc->max_read != ~0)
786 seq_printf(m, ",max_read=%u", fc->max_read);
787 if (sb->s_bdev && sb->s_blocksize != FUSE_DEFAULT_BLKSIZE)
788 seq_printf(m, ",blksize=%lu", sb->s_blocksize);
789 }
790#ifdef CONFIG_FUSE_DAX
791 if (fc->dax_mode == FUSE_DAX_ALWAYS)
792 seq_puts(m, ",dax=always");
793 else if (fc->dax_mode == FUSE_DAX_NEVER)
794 seq_puts(m, ",dax=never");
795 else if (fc->dax_mode == FUSE_DAX_INODE_USER)
796 seq_puts(m, ",dax=inode");
797#endif
798
799 return 0;
800}
801
802static void fuse_iqueue_init(struct fuse_iqueue *fiq,
803 const struct fuse_iqueue_ops *ops,
804 void *priv)
805{
806 memset(fiq, 0, sizeof(struct fuse_iqueue));
807 spin_lock_init(&fiq->lock);
808 init_waitqueue_head(&fiq->waitq);
809 INIT_LIST_HEAD(&fiq->pending);
810 INIT_LIST_HEAD(&fiq->interrupts);
811 fiq->forget_list_tail = &fiq->forget_list_head;
812 fiq->connected = 1;
813 fiq->ops = ops;
814 fiq->priv = priv;
815}
816
817static void fuse_pqueue_init(struct fuse_pqueue *fpq)
818{
819 unsigned int i;
820
821 spin_lock_init(&fpq->lock);
822 for (i = 0; i < FUSE_PQ_HASH_SIZE; i++)
823 INIT_LIST_HEAD(&fpq->processing[i]);
824 INIT_LIST_HEAD(&fpq->io);
825 fpq->connected = 1;
826}
827
828void fuse_conn_init(struct fuse_conn *fc, struct fuse_mount *fm,
829 struct user_namespace *user_ns,
830 const struct fuse_iqueue_ops *fiq_ops, void *fiq_priv)
831{
832 memset(fc, 0, sizeof(*fc));
833 spin_lock_init(&fc->lock);
834 spin_lock_init(&fc->bg_lock);
835 init_rwsem(&fc->killsb);
836 refcount_set(&fc->count, 1);
837 atomic_set(&fc->dev_count, 1);
838 init_waitqueue_head(&fc->blocked_waitq);
839 fuse_iqueue_init(&fc->iq, fiq_ops, fiq_priv);
840 INIT_LIST_HEAD(&fc->bg_queue);
841 INIT_LIST_HEAD(&fc->entry);
842 INIT_LIST_HEAD(&fc->devices);
843 atomic_set(&fc->num_waiting, 0);
844 fc->max_background = FUSE_DEFAULT_MAX_BACKGROUND;
845 fc->congestion_threshold = FUSE_DEFAULT_CONGESTION_THRESHOLD;
846 atomic64_set(&fc->khctr, 0);
847 fc->polled_files = RB_ROOT;
848 fc->blocked = 0;
849 fc->initialized = 0;
850 fc->connected = 1;
851 atomic64_set(&fc->attr_version, 1);
852 get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key));
853 fc->pid_ns = get_pid_ns(task_active_pid_ns(current));
854 fc->user_ns = get_user_ns(user_ns);
855 fc->max_pages = FUSE_DEFAULT_MAX_PAGES_PER_REQ;
856 fc->max_pages_limit = FUSE_MAX_MAX_PAGES;
857
858 INIT_LIST_HEAD(&fc->mounts);
859 list_add(&fm->fc_entry, &fc->mounts);
860 fm->fc = fc;
861}
862EXPORT_SYMBOL_GPL(fuse_conn_init);
863
864void fuse_conn_put(struct fuse_conn *fc)
865{
866 if (refcount_dec_and_test(&fc->count)) {
867 struct fuse_iqueue *fiq = &fc->iq;
868 struct fuse_sync_bucket *bucket;
869
870 if (IS_ENABLED(CONFIG_FUSE_DAX))
871 fuse_dax_conn_free(fc);
872 if (fiq->ops->release)
873 fiq->ops->release(fiq);
874 put_pid_ns(fc->pid_ns);
875 put_user_ns(fc->user_ns);
876 bucket = rcu_dereference_protected(fc->curr_bucket, 1);
877 if (bucket) {
878 WARN_ON(atomic_read(&bucket->count) != 1);
879 kfree(bucket);
880 }
881 fc->release(fc);
882 }
883}
884EXPORT_SYMBOL_GPL(fuse_conn_put);
885
886struct fuse_conn *fuse_conn_get(struct fuse_conn *fc)
887{
888 refcount_inc(&fc->count);
889 return fc;
890}
891EXPORT_SYMBOL_GPL(fuse_conn_get);
892
893static struct inode *fuse_get_root_inode(struct super_block *sb, unsigned mode)
894{
895 struct fuse_attr attr;
896 memset(&attr, 0, sizeof(attr));
897
898 attr.mode = mode;
899 attr.ino = FUSE_ROOT_ID;
900 attr.nlink = 1;
901 return fuse_iget(sb, 1, 0, &attr, 0, 0);
902}
903
904struct fuse_inode_handle {
905 u64 nodeid;
906 u32 generation;
907};
908
909static struct dentry *fuse_get_dentry(struct super_block *sb,
910 struct fuse_inode_handle *handle)
911{
912 struct fuse_conn *fc = get_fuse_conn_super(sb);
913 struct inode *inode;
914 struct dentry *entry;
915 int err = -ESTALE;
916
917 if (handle->nodeid == 0)
918 goto out_err;
919
920 inode = ilookup5(sb, handle->nodeid, fuse_inode_eq, &handle->nodeid);
921 if (!inode) {
922 struct fuse_entry_out outarg;
923 const struct qstr name = QSTR_INIT(".", 1);
924
925 if (!fc->export_support)
926 goto out_err;
927
928 err = fuse_lookup_name(sb, handle->nodeid, &name, &outarg,
929 &inode);
930 if (err && err != -ENOENT)
931 goto out_err;
932 if (err || !inode) {
933 err = -ESTALE;
934 goto out_err;
935 }
936 err = -EIO;
937 if (get_node_id(inode) != handle->nodeid)
938 goto out_iput;
939 }
940 err = -ESTALE;
941 if (inode->i_generation != handle->generation)
942 goto out_iput;
943
944 entry = d_obtain_alias(inode);
945 if (!IS_ERR(entry) && get_node_id(inode) != FUSE_ROOT_ID)
946 fuse_invalidate_entry_cache(entry);
947
948 return entry;
949
950 out_iput:
951 iput(inode);
952 out_err:
953 return ERR_PTR(err);
954}
955
956static int fuse_encode_fh(struct inode *inode, u32 *fh, int *max_len,
957 struct inode *parent)
958{
959 int len = parent ? 6 : 3;
960 u64 nodeid;
961 u32 generation;
962
963 if (*max_len < len) {
964 *max_len = len;
965 return FILEID_INVALID;
966 }
967
968 nodeid = get_fuse_inode(inode)->nodeid;
969 generation = inode->i_generation;
970
971 fh[0] = (u32)(nodeid >> 32);
972 fh[1] = (u32)(nodeid & 0xffffffff);
973 fh[2] = generation;
974
975 if (parent) {
976 nodeid = get_fuse_inode(parent)->nodeid;
977 generation = parent->i_generation;
978
979 fh[3] = (u32)(nodeid >> 32);
980 fh[4] = (u32)(nodeid & 0xffffffff);
981 fh[5] = generation;
982 }
983
984 *max_len = len;
985 return parent ? 0x82 : 0x81;
986}
987
988static struct dentry *fuse_fh_to_dentry(struct super_block *sb,
989 struct fid *fid, int fh_len, int fh_type)
990{
991 struct fuse_inode_handle handle;
992
993 if ((fh_type != 0x81 && fh_type != 0x82) || fh_len < 3)
994 return NULL;
995
996 handle.nodeid = (u64) fid->raw[0] << 32;
997 handle.nodeid |= (u64) fid->raw[1];
998 handle.generation = fid->raw[2];
999 return fuse_get_dentry(sb, &handle);
1000}
1001
1002static struct dentry *fuse_fh_to_parent(struct super_block *sb,
1003 struct fid *fid, int fh_len, int fh_type)
1004{
1005 struct fuse_inode_handle parent;
1006
1007 if (fh_type != 0x82 || fh_len < 6)
1008 return NULL;
1009
1010 parent.nodeid = (u64) fid->raw[3] << 32;
1011 parent.nodeid |= (u64) fid->raw[4];
1012 parent.generation = fid->raw[5];
1013 return fuse_get_dentry(sb, &parent);
1014}
1015
1016static struct dentry *fuse_get_parent(struct dentry *child)
1017{
1018 struct inode *child_inode = d_inode(child);
1019 struct fuse_conn *fc = get_fuse_conn(child_inode);
1020 struct inode *inode;
1021 struct dentry *parent;
1022 struct fuse_entry_out outarg;
1023 int err;
1024
1025 if (!fc->export_support)
1026 return ERR_PTR(-ESTALE);
1027
1028 err = fuse_lookup_name(child_inode->i_sb, get_node_id(child_inode),
1029 &dotdot_name, &outarg, &inode);
1030 if (err) {
1031 if (err == -ENOENT)
1032 return ERR_PTR(-ESTALE);
1033 return ERR_PTR(err);
1034 }
1035
1036 parent = d_obtain_alias(inode);
1037 if (!IS_ERR(parent) && get_node_id(inode) != FUSE_ROOT_ID)
1038 fuse_invalidate_entry_cache(parent);
1039
1040 return parent;
1041}
1042
1043static const struct export_operations fuse_export_operations = {
1044 .fh_to_dentry = fuse_fh_to_dentry,
1045 .fh_to_parent = fuse_fh_to_parent,
1046 .encode_fh = fuse_encode_fh,
1047 .get_parent = fuse_get_parent,
1048};
1049
1050static const struct super_operations fuse_super_operations = {
1051 .alloc_inode = fuse_alloc_inode,
1052 .free_inode = fuse_free_inode,
1053 .evict_inode = fuse_evict_inode,
1054 .write_inode = fuse_write_inode,
1055 .drop_inode = generic_delete_inode,
1056 .umount_begin = fuse_umount_begin,
1057 .statfs = fuse_statfs,
1058 .sync_fs = fuse_sync_fs,
1059 .show_options = fuse_show_options,
1060};
1061
1062static void sanitize_global_limit(unsigned *limit)
1063{
1064 /*
1065 * The default maximum number of async requests is calculated to consume
1066 * 1/2^13 of the total memory, assuming 392 bytes per request.
1067 */
1068 if (*limit == 0)
1069 *limit = ((totalram_pages() << PAGE_SHIFT) >> 13) / 392;
1070
1071 if (*limit >= 1 << 16)
1072 *limit = (1 << 16) - 1;
1073}
1074
1075static int set_global_limit(const char *val, const struct kernel_param *kp)
1076{
1077 int rv;
1078
1079 rv = param_set_uint(val, kp);
1080 if (rv)
1081 return rv;
1082
1083 sanitize_global_limit((unsigned *)kp->arg);
1084
1085 return 0;
1086}
1087
1088static void process_init_limits(struct fuse_conn *fc, struct fuse_init_out *arg)
1089{
1090 int cap_sys_admin = capable(CAP_SYS_ADMIN);
1091
1092 if (arg->minor < 13)
1093 return;
1094
1095 sanitize_global_limit(&max_user_bgreq);
1096 sanitize_global_limit(&max_user_congthresh);
1097
1098 spin_lock(&fc->bg_lock);
1099 if (arg->max_background) {
1100 fc->max_background = arg->max_background;
1101
1102 if (!cap_sys_admin && fc->max_background > max_user_bgreq)
1103 fc->max_background = max_user_bgreq;
1104 }
1105 if (arg->congestion_threshold) {
1106 fc->congestion_threshold = arg->congestion_threshold;
1107
1108 if (!cap_sys_admin &&
1109 fc->congestion_threshold > max_user_congthresh)
1110 fc->congestion_threshold = max_user_congthresh;
1111 }
1112 spin_unlock(&fc->bg_lock);
1113}
1114
1115struct fuse_init_args {
1116 struct fuse_args args;
1117 struct fuse_init_in in;
1118 struct fuse_init_out out;
1119};
1120
1121static void process_init_reply(struct fuse_mount *fm, struct fuse_args *args,
1122 int error)
1123{
1124 struct fuse_conn *fc = fm->fc;
1125 struct fuse_init_args *ia = container_of(args, typeof(*ia), args);
1126 struct fuse_init_out *arg = &ia->out;
1127 bool ok = true;
1128
1129 if (error || arg->major != FUSE_KERNEL_VERSION)
1130 ok = false;
1131 else {
1132 unsigned long ra_pages;
1133
1134 process_init_limits(fc, arg);
1135
1136 if (arg->minor >= 6) {
1137 u64 flags = arg->flags | (u64) arg->flags2 << 32;
1138
1139 ra_pages = arg->max_readahead / PAGE_SIZE;
1140 if (flags & FUSE_ASYNC_READ)
1141 fc->async_read = 1;
1142 if (!(flags & FUSE_POSIX_LOCKS))
1143 fc->no_lock = 1;
1144 if (arg->minor >= 17) {
1145 if (!(flags & FUSE_FLOCK_LOCKS))
1146 fc->no_flock = 1;
1147 } else {
1148 if (!(flags & FUSE_POSIX_LOCKS))
1149 fc->no_flock = 1;
1150 }
1151 if (flags & FUSE_ATOMIC_O_TRUNC)
1152 fc->atomic_o_trunc = 1;
1153 if (arg->minor >= 9) {
1154 /* LOOKUP has dependency on proto version */
1155 if (flags & FUSE_EXPORT_SUPPORT)
1156 fc->export_support = 1;
1157 }
1158 if (flags & FUSE_BIG_WRITES)
1159 fc->big_writes = 1;
1160 if (flags & FUSE_DONT_MASK)
1161 fc->dont_mask = 1;
1162 if (flags & FUSE_AUTO_INVAL_DATA)
1163 fc->auto_inval_data = 1;
1164 else if (flags & FUSE_EXPLICIT_INVAL_DATA)
1165 fc->explicit_inval_data = 1;
1166 if (flags & FUSE_DO_READDIRPLUS) {
1167 fc->do_readdirplus = 1;
1168 if (flags & FUSE_READDIRPLUS_AUTO)
1169 fc->readdirplus_auto = 1;
1170 }
1171 if (flags & FUSE_ASYNC_DIO)
1172 fc->async_dio = 1;
1173 if (flags & FUSE_WRITEBACK_CACHE)
1174 fc->writeback_cache = 1;
1175 if (flags & FUSE_PARALLEL_DIROPS)
1176 fc->parallel_dirops = 1;
1177 if (flags & FUSE_HANDLE_KILLPRIV)
1178 fc->handle_killpriv = 1;
1179 if (arg->time_gran && arg->time_gran <= 1000000000)
1180 fm->sb->s_time_gran = arg->time_gran;
1181 if ((flags & FUSE_POSIX_ACL)) {
1182 fc->default_permissions = 1;
1183 fc->posix_acl = 1;
1184 }
1185 if (flags & FUSE_CACHE_SYMLINKS)
1186 fc->cache_symlinks = 1;
1187 if (flags & FUSE_ABORT_ERROR)
1188 fc->abort_err = 1;
1189 if (flags & FUSE_MAX_PAGES) {
1190 fc->max_pages =
1191 min_t(unsigned int, fc->max_pages_limit,
1192 max_t(unsigned int, arg->max_pages, 1));
1193 }
1194 if (IS_ENABLED(CONFIG_FUSE_DAX)) {
1195 if (flags & FUSE_MAP_ALIGNMENT &&
1196 !fuse_dax_check_alignment(fc, arg->map_alignment)) {
1197 ok = false;
1198 }
1199 if (flags & FUSE_HAS_INODE_DAX)
1200 fc->inode_dax = 1;
1201 }
1202 if (flags & FUSE_HANDLE_KILLPRIV_V2) {
1203 fc->handle_killpriv_v2 = 1;
1204 fm->sb->s_flags |= SB_NOSEC;
1205 }
1206 if (flags & FUSE_SETXATTR_EXT)
1207 fc->setxattr_ext = 1;
1208 if (flags & FUSE_SECURITY_CTX)
1209 fc->init_security = 1;
1210 } else {
1211 ra_pages = fc->max_read / PAGE_SIZE;
1212 fc->no_lock = 1;
1213 fc->no_flock = 1;
1214 }
1215
1216 fm->sb->s_bdi->ra_pages =
1217 min(fm->sb->s_bdi->ra_pages, ra_pages);
1218 fc->minor = arg->minor;
1219 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
1220 fc->max_write = max_t(unsigned, 4096, fc->max_write);
1221 fc->conn_init = 1;
1222 }
1223 kfree(ia);
1224
1225 if (!ok) {
1226 fc->conn_init = 0;
1227 fc->conn_error = 1;
1228 }
1229
1230 fuse_set_initialized(fc);
1231 wake_up_all(&fc->blocked_waitq);
1232}
1233
1234void fuse_send_init(struct fuse_mount *fm)
1235{
1236 struct fuse_init_args *ia;
1237 u64 flags;
1238
1239 ia = kzalloc(sizeof(*ia), GFP_KERNEL | __GFP_NOFAIL);
1240
1241 ia->in.major = FUSE_KERNEL_VERSION;
1242 ia->in.minor = FUSE_KERNEL_MINOR_VERSION;
1243 ia->in.max_readahead = fm->sb->s_bdi->ra_pages * PAGE_SIZE;
1244 flags =
1245 FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_ATOMIC_O_TRUNC |
1246 FUSE_EXPORT_SUPPORT | FUSE_BIG_WRITES | FUSE_DONT_MASK |
1247 FUSE_SPLICE_WRITE | FUSE_SPLICE_MOVE | FUSE_SPLICE_READ |
1248 FUSE_FLOCK_LOCKS | FUSE_HAS_IOCTL_DIR | FUSE_AUTO_INVAL_DATA |
1249 FUSE_DO_READDIRPLUS | FUSE_READDIRPLUS_AUTO | FUSE_ASYNC_DIO |
1250 FUSE_WRITEBACK_CACHE | FUSE_NO_OPEN_SUPPORT |
1251 FUSE_PARALLEL_DIROPS | FUSE_HANDLE_KILLPRIV | FUSE_POSIX_ACL |
1252 FUSE_ABORT_ERROR | FUSE_MAX_PAGES | FUSE_CACHE_SYMLINKS |
1253 FUSE_NO_OPENDIR_SUPPORT | FUSE_EXPLICIT_INVAL_DATA |
1254 FUSE_HANDLE_KILLPRIV_V2 | FUSE_SETXATTR_EXT | FUSE_INIT_EXT |
1255 FUSE_SECURITY_CTX;
1256#ifdef CONFIG_FUSE_DAX
1257 if (fm->fc->dax)
1258 flags |= FUSE_MAP_ALIGNMENT;
1259 if (fuse_is_inode_dax_mode(fm->fc->dax_mode))
1260 flags |= FUSE_HAS_INODE_DAX;
1261#endif
1262 if (fm->fc->auto_submounts)
1263 flags |= FUSE_SUBMOUNTS;
1264
1265 ia->in.flags = flags;
1266 ia->in.flags2 = flags >> 32;
1267
1268 ia->args.opcode = FUSE_INIT;
1269 ia->args.in_numargs = 1;
1270 ia->args.in_args[0].size = sizeof(ia->in);
1271 ia->args.in_args[0].value = &ia->in;
1272 ia->args.out_numargs = 1;
1273 /* Variable length argument used for backward compatibility
1274 with interface version < 7.5. Rest of init_out is zeroed
1275 by do_get_request(), so a short reply is not a problem */
1276 ia->args.out_argvar = true;
1277 ia->args.out_args[0].size = sizeof(ia->out);
1278 ia->args.out_args[0].value = &ia->out;
1279 ia->args.force = true;
1280 ia->args.nocreds = true;
1281 ia->args.end = process_init_reply;
1282
1283 if (fuse_simple_background(fm, &ia->args, GFP_KERNEL) != 0)
1284 process_init_reply(fm, &ia->args, -ENOTCONN);
1285}
1286EXPORT_SYMBOL_GPL(fuse_send_init);
1287
1288void fuse_free_conn(struct fuse_conn *fc)
1289{
1290 WARN_ON(!list_empty(&fc->devices));
1291 kfree_rcu(fc, rcu);
1292}
1293EXPORT_SYMBOL_GPL(fuse_free_conn);
1294
1295static int fuse_bdi_init(struct fuse_conn *fc, struct super_block *sb)
1296{
1297 int err;
1298 char *suffix = "";
1299
1300 if (sb->s_bdev) {
1301 suffix = "-fuseblk";
1302 /*
1303 * sb->s_bdi points to blkdev's bdi however we want to redirect
1304 * it to our private bdi...
1305 */
1306 bdi_put(sb->s_bdi);
1307 sb->s_bdi = &noop_backing_dev_info;
1308 }
1309 err = super_setup_bdi_name(sb, "%u:%u%s", MAJOR(fc->dev),
1310 MINOR(fc->dev), suffix);
1311 if (err)
1312 return err;
1313
1314 /* fuse does it's own writeback accounting */
1315 sb->s_bdi->capabilities &= ~BDI_CAP_WRITEBACK_ACCT;
1316 sb->s_bdi->capabilities |= BDI_CAP_STRICTLIMIT;
1317
1318 /*
1319 * For a single fuse filesystem use max 1% of dirty +
1320 * writeback threshold.
1321 *
1322 * This gives about 1M of write buffer for memory maps on a
1323 * machine with 1G and 10% dirty_ratio, which should be more
1324 * than enough.
1325 *
1326 * Privileged users can raise it by writing to
1327 *
1328 * /sys/class/bdi/<bdi>/max_ratio
1329 */
1330 bdi_set_max_ratio(sb->s_bdi, 1);
1331
1332 return 0;
1333}
1334
1335struct fuse_dev *fuse_dev_alloc(void)
1336{
1337 struct fuse_dev *fud;
1338 struct list_head *pq;
1339
1340 fud = kzalloc(sizeof(struct fuse_dev), GFP_KERNEL);
1341 if (!fud)
1342 return NULL;
1343
1344 pq = kcalloc(FUSE_PQ_HASH_SIZE, sizeof(struct list_head), GFP_KERNEL);
1345 if (!pq) {
1346 kfree(fud);
1347 return NULL;
1348 }
1349
1350 fud->pq.processing = pq;
1351 fuse_pqueue_init(&fud->pq);
1352
1353 return fud;
1354}
1355EXPORT_SYMBOL_GPL(fuse_dev_alloc);
1356
1357void fuse_dev_install(struct fuse_dev *fud, struct fuse_conn *fc)
1358{
1359 fud->fc = fuse_conn_get(fc);
1360 spin_lock(&fc->lock);
1361 list_add_tail(&fud->entry, &fc->devices);
1362 spin_unlock(&fc->lock);
1363}
1364EXPORT_SYMBOL_GPL(fuse_dev_install);
1365
1366struct fuse_dev *fuse_dev_alloc_install(struct fuse_conn *fc)
1367{
1368 struct fuse_dev *fud;
1369
1370 fud = fuse_dev_alloc();
1371 if (!fud)
1372 return NULL;
1373
1374 fuse_dev_install(fud, fc);
1375 return fud;
1376}
1377EXPORT_SYMBOL_GPL(fuse_dev_alloc_install);
1378
1379void fuse_dev_free(struct fuse_dev *fud)
1380{
1381 struct fuse_conn *fc = fud->fc;
1382
1383 if (fc) {
1384 spin_lock(&fc->lock);
1385 list_del(&fud->entry);
1386 spin_unlock(&fc->lock);
1387
1388 fuse_conn_put(fc);
1389 }
1390 kfree(fud->pq.processing);
1391 kfree(fud);
1392}
1393EXPORT_SYMBOL_GPL(fuse_dev_free);
1394
1395static void fuse_fill_attr_from_inode(struct fuse_attr *attr,
1396 const struct fuse_inode *fi)
1397{
1398 *attr = (struct fuse_attr){
1399 .ino = fi->inode.i_ino,
1400 .size = fi->inode.i_size,
1401 .blocks = fi->inode.i_blocks,
1402 .atime = fi->inode.i_atime.tv_sec,
1403 .mtime = fi->inode.i_mtime.tv_sec,
1404 .ctime = fi->inode.i_ctime.tv_sec,
1405 .atimensec = fi->inode.i_atime.tv_nsec,
1406 .mtimensec = fi->inode.i_mtime.tv_nsec,
1407 .ctimensec = fi->inode.i_ctime.tv_nsec,
1408 .mode = fi->inode.i_mode,
1409 .nlink = fi->inode.i_nlink,
1410 .uid = fi->inode.i_uid.val,
1411 .gid = fi->inode.i_gid.val,
1412 .rdev = fi->inode.i_rdev,
1413 .blksize = 1u << fi->inode.i_blkbits,
1414 };
1415}
1416
1417static void fuse_sb_defaults(struct super_block *sb)
1418{
1419 sb->s_magic = FUSE_SUPER_MAGIC;
1420 sb->s_op = &fuse_super_operations;
1421 sb->s_xattr = fuse_xattr_handlers;
1422 sb->s_maxbytes = MAX_LFS_FILESIZE;
1423 sb->s_time_gran = 1;
1424 sb->s_export_op = &fuse_export_operations;
1425 sb->s_iflags |= SB_I_IMA_UNVERIFIABLE_SIGNATURE;
1426 if (sb->s_user_ns != &init_user_ns)
1427 sb->s_iflags |= SB_I_UNTRUSTED_MOUNTER;
1428 sb->s_flags &= ~(SB_NOSEC | SB_I_VERSION);
1429}
1430
1431static int fuse_fill_super_submount(struct super_block *sb,
1432 struct fuse_inode *parent_fi)
1433{
1434 struct fuse_mount *fm = get_fuse_mount_super(sb);
1435 struct super_block *parent_sb = parent_fi->inode.i_sb;
1436 struct fuse_attr root_attr;
1437 struct inode *root;
1438
1439 fuse_sb_defaults(sb);
1440 fm->sb = sb;
1441
1442 WARN_ON(sb->s_bdi != &noop_backing_dev_info);
1443 sb->s_bdi = bdi_get(parent_sb->s_bdi);
1444
1445 sb->s_xattr = parent_sb->s_xattr;
1446 sb->s_time_gran = parent_sb->s_time_gran;
1447 sb->s_blocksize = parent_sb->s_blocksize;
1448 sb->s_blocksize_bits = parent_sb->s_blocksize_bits;
1449 sb->s_subtype = kstrdup(parent_sb->s_subtype, GFP_KERNEL);
1450 if (parent_sb->s_subtype && !sb->s_subtype)
1451 return -ENOMEM;
1452
1453 fuse_fill_attr_from_inode(&root_attr, parent_fi);
1454 root = fuse_iget(sb, parent_fi->nodeid, 0, &root_attr, 0, 0);
1455 /*
1456 * This inode is just a duplicate, so it is not looked up and
1457 * its nlookup should not be incremented. fuse_iget() does
1458 * that, though, so undo it here.
1459 */
1460 get_fuse_inode(root)->nlookup--;
1461 sb->s_d_op = &fuse_dentry_operations;
1462 sb->s_root = d_make_root(root);
1463 if (!sb->s_root)
1464 return -ENOMEM;
1465
1466 return 0;
1467}
1468
1469/* Filesystem context private data holds the FUSE inode of the mount point */
1470static int fuse_get_tree_submount(struct fs_context *fsc)
1471{
1472 struct fuse_mount *fm;
1473 struct fuse_inode *mp_fi = fsc->fs_private;
1474 struct fuse_conn *fc = get_fuse_conn(&mp_fi->inode);
1475 struct super_block *sb;
1476 int err;
1477
1478 fm = kzalloc(sizeof(struct fuse_mount), GFP_KERNEL);
1479 if (!fm)
1480 return -ENOMEM;
1481
1482 fm->fc = fuse_conn_get(fc);
1483 fsc->s_fs_info = fm;
1484 sb = sget_fc(fsc, NULL, set_anon_super_fc);
1485 if (fsc->s_fs_info)
1486 fuse_mount_destroy(fm);
1487 if (IS_ERR(sb))
1488 return PTR_ERR(sb);
1489
1490 /* Initialize superblock, making @mp_fi its root */
1491 err = fuse_fill_super_submount(sb, mp_fi);
1492 if (err) {
1493 deactivate_locked_super(sb);
1494 return err;
1495 }
1496
1497 down_write(&fc->killsb);
1498 list_add_tail(&fm->fc_entry, &fc->mounts);
1499 up_write(&fc->killsb);
1500
1501 sb->s_flags |= SB_ACTIVE;
1502 fsc->root = dget(sb->s_root);
1503
1504 return 0;
1505}
1506
1507static const struct fs_context_operations fuse_context_submount_ops = {
1508 .get_tree = fuse_get_tree_submount,
1509};
1510
1511int fuse_init_fs_context_submount(struct fs_context *fsc)
1512{
1513 fsc->ops = &fuse_context_submount_ops;
1514 return 0;
1515}
1516EXPORT_SYMBOL_GPL(fuse_init_fs_context_submount);
1517
1518int fuse_fill_super_common(struct super_block *sb, struct fuse_fs_context *ctx)
1519{
1520 struct fuse_dev *fud = NULL;
1521 struct fuse_mount *fm = get_fuse_mount_super(sb);
1522 struct fuse_conn *fc = fm->fc;
1523 struct inode *root;
1524 struct dentry *root_dentry;
1525 int err;
1526
1527 err = -EINVAL;
1528 if (sb->s_flags & SB_MANDLOCK)
1529 goto err;
1530
1531 rcu_assign_pointer(fc->curr_bucket, fuse_sync_bucket_alloc());
1532 fuse_sb_defaults(sb);
1533
1534 if (ctx->is_bdev) {
1535#ifdef CONFIG_BLOCK
1536 err = -EINVAL;
1537 if (!sb_set_blocksize(sb, ctx->blksize))
1538 goto err;
1539#endif
1540 } else {
1541 sb->s_blocksize = PAGE_SIZE;
1542 sb->s_blocksize_bits = PAGE_SHIFT;
1543 }
1544
1545 sb->s_subtype = ctx->subtype;
1546 ctx->subtype = NULL;
1547 if (IS_ENABLED(CONFIG_FUSE_DAX)) {
1548 err = fuse_dax_conn_alloc(fc, ctx->dax_mode, ctx->dax_dev);
1549 if (err)
1550 goto err;
1551 }
1552
1553 if (ctx->fudptr) {
1554 err = -ENOMEM;
1555 fud = fuse_dev_alloc_install(fc);
1556 if (!fud)
1557 goto err_free_dax;
1558 }
1559
1560 fc->dev = sb->s_dev;
1561 fm->sb = sb;
1562 err = fuse_bdi_init(fc, sb);
1563 if (err)
1564 goto err_dev_free;
1565
1566 /* Handle umasking inside the fuse code */
1567 if (sb->s_flags & SB_POSIXACL)
1568 fc->dont_mask = 1;
1569 sb->s_flags |= SB_POSIXACL;
1570
1571 fc->default_permissions = ctx->default_permissions;
1572 fc->allow_other = ctx->allow_other;
1573 fc->user_id = ctx->user_id;
1574 fc->group_id = ctx->group_id;
1575 fc->legacy_opts_show = ctx->legacy_opts_show;
1576 fc->max_read = max_t(unsigned int, 4096, ctx->max_read);
1577 fc->destroy = ctx->destroy;
1578 fc->no_control = ctx->no_control;
1579 fc->no_force_umount = ctx->no_force_umount;
1580
1581 err = -ENOMEM;
1582 root = fuse_get_root_inode(sb, ctx->rootmode);
1583 sb->s_d_op = &fuse_root_dentry_operations;
1584 root_dentry = d_make_root(root);
1585 if (!root_dentry)
1586 goto err_dev_free;
1587 /* Root dentry doesn't have .d_revalidate */
1588 sb->s_d_op = &fuse_dentry_operations;
1589
1590 mutex_lock(&fuse_mutex);
1591 err = -EINVAL;
1592 if (ctx->fudptr && *ctx->fudptr)
1593 goto err_unlock;
1594
1595 err = fuse_ctl_add_conn(fc);
1596 if (err)
1597 goto err_unlock;
1598
1599 list_add_tail(&fc->entry, &fuse_conn_list);
1600 sb->s_root = root_dentry;
1601 if (ctx->fudptr)
1602 *ctx->fudptr = fud;
1603 mutex_unlock(&fuse_mutex);
1604 return 0;
1605
1606 err_unlock:
1607 mutex_unlock(&fuse_mutex);
1608 dput(root_dentry);
1609 err_dev_free:
1610 if (fud)
1611 fuse_dev_free(fud);
1612 err_free_dax:
1613 if (IS_ENABLED(CONFIG_FUSE_DAX))
1614 fuse_dax_conn_free(fc);
1615 err:
1616 return err;
1617}
1618EXPORT_SYMBOL_GPL(fuse_fill_super_common);
1619
1620static int fuse_fill_super(struct super_block *sb, struct fs_context *fsc)
1621{
1622 struct fuse_fs_context *ctx = fsc->fs_private;
1623 int err;
1624
1625 if (!ctx->file || !ctx->rootmode_present ||
1626 !ctx->user_id_present || !ctx->group_id_present)
1627 return -EINVAL;
1628
1629 /*
1630 * Require mount to happen from the same user namespace which
1631 * opened /dev/fuse to prevent potential attacks.
1632 */
1633 if ((ctx->file->f_op != &fuse_dev_operations) ||
1634 (ctx->file->f_cred->user_ns != sb->s_user_ns))
1635 return -EINVAL;
1636 ctx->fudptr = &ctx->file->private_data;
1637
1638 err = fuse_fill_super_common(sb, ctx);
1639 if (err)
1640 return err;
1641 /* file->private_data shall be visible on all CPUs after this */
1642 smp_mb();
1643 fuse_send_init(get_fuse_mount_super(sb));
1644 return 0;
1645}
1646
1647/*
1648 * This is the path where user supplied an already initialized fuse dev. In
1649 * this case never create a new super if the old one is gone.
1650 */
1651static int fuse_set_no_super(struct super_block *sb, struct fs_context *fsc)
1652{
1653 return -ENOTCONN;
1654}
1655
1656static int fuse_test_super(struct super_block *sb, struct fs_context *fsc)
1657{
1658
1659 return fsc->sget_key == get_fuse_conn_super(sb);
1660}
1661
1662static int fuse_get_tree(struct fs_context *fsc)
1663{
1664 struct fuse_fs_context *ctx = fsc->fs_private;
1665 struct fuse_dev *fud;
1666 struct fuse_conn *fc;
1667 struct fuse_mount *fm;
1668 struct super_block *sb;
1669 int err;
1670
1671 fc = kmalloc(sizeof(*fc), GFP_KERNEL);
1672 if (!fc)
1673 return -ENOMEM;
1674
1675 fm = kzalloc(sizeof(*fm), GFP_KERNEL);
1676 if (!fm) {
1677 kfree(fc);
1678 return -ENOMEM;
1679 }
1680
1681 fuse_conn_init(fc, fm, fsc->user_ns, &fuse_dev_fiq_ops, NULL);
1682 fc->release = fuse_free_conn;
1683
1684 fsc->s_fs_info = fm;
1685
1686 if (ctx->fd_present)
1687 ctx->file = fget(ctx->fd);
1688
1689 if (IS_ENABLED(CONFIG_BLOCK) && ctx->is_bdev) {
1690 err = get_tree_bdev(fsc, fuse_fill_super);
1691 goto out;
1692 }
1693 /*
1694 * While block dev mount can be initialized with a dummy device fd
1695 * (found by device name), normal fuse mounts can't
1696 */
1697 err = -EINVAL;
1698 if (!ctx->file)
1699 goto out;
1700
1701 /*
1702 * Allow creating a fuse mount with an already initialized fuse
1703 * connection
1704 */
1705 fud = READ_ONCE(ctx->file->private_data);
1706 if (ctx->file->f_op == &fuse_dev_operations && fud) {
1707 fsc->sget_key = fud->fc;
1708 sb = sget_fc(fsc, fuse_test_super, fuse_set_no_super);
1709 err = PTR_ERR_OR_ZERO(sb);
1710 if (!IS_ERR(sb))
1711 fsc->root = dget(sb->s_root);
1712 } else {
1713 err = get_tree_nodev(fsc, fuse_fill_super);
1714 }
1715out:
1716 if (fsc->s_fs_info)
1717 fuse_mount_destroy(fm);
1718 if (ctx->file)
1719 fput(ctx->file);
1720 return err;
1721}
1722
1723static const struct fs_context_operations fuse_context_ops = {
1724 .free = fuse_free_fsc,
1725 .parse_param = fuse_parse_param,
1726 .reconfigure = fuse_reconfigure,
1727 .get_tree = fuse_get_tree,
1728};
1729
1730/*
1731 * Set up the filesystem mount context.
1732 */
1733static int fuse_init_fs_context(struct fs_context *fsc)
1734{
1735 struct fuse_fs_context *ctx;
1736
1737 ctx = kzalloc(sizeof(struct fuse_fs_context), GFP_KERNEL);
1738 if (!ctx)
1739 return -ENOMEM;
1740
1741 ctx->max_read = ~0;
1742 ctx->blksize = FUSE_DEFAULT_BLKSIZE;
1743 ctx->legacy_opts_show = true;
1744
1745#ifdef CONFIG_BLOCK
1746 if (fsc->fs_type == &fuseblk_fs_type) {
1747 ctx->is_bdev = true;
1748 ctx->destroy = true;
1749 }
1750#endif
1751
1752 fsc->fs_private = ctx;
1753 fsc->ops = &fuse_context_ops;
1754 return 0;
1755}
1756
1757bool fuse_mount_remove(struct fuse_mount *fm)
1758{
1759 struct fuse_conn *fc = fm->fc;
1760 bool last = false;
1761
1762 down_write(&fc->killsb);
1763 list_del_init(&fm->fc_entry);
1764 if (list_empty(&fc->mounts))
1765 last = true;
1766 up_write(&fc->killsb);
1767
1768 return last;
1769}
1770EXPORT_SYMBOL_GPL(fuse_mount_remove);
1771
1772void fuse_conn_destroy(struct fuse_mount *fm)
1773{
1774 struct fuse_conn *fc = fm->fc;
1775
1776 if (fc->destroy)
1777 fuse_send_destroy(fm);
1778
1779 fuse_abort_conn(fc);
1780 fuse_wait_aborted(fc);
1781
1782 if (!list_empty(&fc->entry)) {
1783 mutex_lock(&fuse_mutex);
1784 list_del(&fc->entry);
1785 fuse_ctl_remove_conn(fc);
1786 mutex_unlock(&fuse_mutex);
1787 }
1788}
1789EXPORT_SYMBOL_GPL(fuse_conn_destroy);
1790
1791static void fuse_sb_destroy(struct super_block *sb)
1792{
1793 struct fuse_mount *fm = get_fuse_mount_super(sb);
1794 bool last;
1795
1796 if (sb->s_root) {
1797 last = fuse_mount_remove(fm);
1798 if (last)
1799 fuse_conn_destroy(fm);
1800 }
1801}
1802
1803void fuse_mount_destroy(struct fuse_mount *fm)
1804{
1805 fuse_conn_put(fm->fc);
1806 kfree(fm);
1807}
1808EXPORT_SYMBOL(fuse_mount_destroy);
1809
1810static void fuse_kill_sb_anon(struct super_block *sb)
1811{
1812 fuse_sb_destroy(sb);
1813 kill_anon_super(sb);
1814 fuse_mount_destroy(get_fuse_mount_super(sb));
1815}
1816
1817static struct file_system_type fuse_fs_type = {
1818 .owner = THIS_MODULE,
1819 .name = "fuse",
1820 .fs_flags = FS_HAS_SUBTYPE | FS_USERNS_MOUNT,
1821 .init_fs_context = fuse_init_fs_context,
1822 .parameters = fuse_fs_parameters,
1823 .kill_sb = fuse_kill_sb_anon,
1824};
1825MODULE_ALIAS_FS("fuse");
1826
1827#ifdef CONFIG_BLOCK
1828static void fuse_kill_sb_blk(struct super_block *sb)
1829{
1830 fuse_sb_destroy(sb);
1831 kill_block_super(sb);
1832 fuse_mount_destroy(get_fuse_mount_super(sb));
1833}
1834
1835static struct file_system_type fuseblk_fs_type = {
1836 .owner = THIS_MODULE,
1837 .name = "fuseblk",
1838 .init_fs_context = fuse_init_fs_context,
1839 .parameters = fuse_fs_parameters,
1840 .kill_sb = fuse_kill_sb_blk,
1841 .fs_flags = FS_REQUIRES_DEV | FS_HAS_SUBTYPE,
1842};
1843MODULE_ALIAS_FS("fuseblk");
1844
1845static inline int register_fuseblk(void)
1846{
1847 return register_filesystem(&fuseblk_fs_type);
1848}
1849
1850static inline void unregister_fuseblk(void)
1851{
1852 unregister_filesystem(&fuseblk_fs_type);
1853}
1854#else
1855static inline int register_fuseblk(void)
1856{
1857 return 0;
1858}
1859
1860static inline void unregister_fuseblk(void)
1861{
1862}
1863#endif
1864
1865static void fuse_inode_init_once(void *foo)
1866{
1867 struct inode *inode = foo;
1868
1869 inode_init_once(inode);
1870}
1871
1872static int __init fuse_fs_init(void)
1873{
1874 int err;
1875
1876 fuse_inode_cachep = kmem_cache_create("fuse_inode",
1877 sizeof(struct fuse_inode), 0,
1878 SLAB_HWCACHE_ALIGN|SLAB_ACCOUNT|SLAB_RECLAIM_ACCOUNT,
1879 fuse_inode_init_once);
1880 err = -ENOMEM;
1881 if (!fuse_inode_cachep)
1882 goto out;
1883
1884 err = register_fuseblk();
1885 if (err)
1886 goto out2;
1887
1888 err = register_filesystem(&fuse_fs_type);
1889 if (err)
1890 goto out3;
1891
1892 return 0;
1893
1894 out3:
1895 unregister_fuseblk();
1896 out2:
1897 kmem_cache_destroy(fuse_inode_cachep);
1898 out:
1899 return err;
1900}
1901
1902static void fuse_fs_cleanup(void)
1903{
1904 unregister_filesystem(&fuse_fs_type);
1905 unregister_fuseblk();
1906
1907 /*
1908 * Make sure all delayed rcu free inodes are flushed before we
1909 * destroy cache.
1910 */
1911 rcu_barrier();
1912 kmem_cache_destroy(fuse_inode_cachep);
1913}
1914
1915static struct kobject *fuse_kobj;
1916
1917static int fuse_sysfs_init(void)
1918{
1919 int err;
1920
1921 fuse_kobj = kobject_create_and_add("fuse", fs_kobj);
1922 if (!fuse_kobj) {
1923 err = -ENOMEM;
1924 goto out_err;
1925 }
1926
1927 err = sysfs_create_mount_point(fuse_kobj, "connections");
1928 if (err)
1929 goto out_fuse_unregister;
1930
1931 return 0;
1932
1933 out_fuse_unregister:
1934 kobject_put(fuse_kobj);
1935 out_err:
1936 return err;
1937}
1938
1939static void fuse_sysfs_cleanup(void)
1940{
1941 sysfs_remove_mount_point(fuse_kobj, "connections");
1942 kobject_put(fuse_kobj);
1943}
1944
1945static int __init fuse_init(void)
1946{
1947 int res;
1948
1949 pr_info("init (API version %i.%i)\n",
1950 FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
1951
1952 INIT_LIST_HEAD(&fuse_conn_list);
1953 res = fuse_fs_init();
1954 if (res)
1955 goto err;
1956
1957 res = fuse_dev_init();
1958 if (res)
1959 goto err_fs_cleanup;
1960
1961 res = fuse_sysfs_init();
1962 if (res)
1963 goto err_dev_cleanup;
1964
1965 res = fuse_ctl_init();
1966 if (res)
1967 goto err_sysfs_cleanup;
1968
1969 sanitize_global_limit(&max_user_bgreq);
1970 sanitize_global_limit(&max_user_congthresh);
1971
1972 return 0;
1973
1974 err_sysfs_cleanup:
1975 fuse_sysfs_cleanup();
1976 err_dev_cleanup:
1977 fuse_dev_cleanup();
1978 err_fs_cleanup:
1979 fuse_fs_cleanup();
1980 err:
1981 return res;
1982}
1983
1984static void __exit fuse_exit(void)
1985{
1986 pr_debug("exit\n");
1987
1988 fuse_ctl_cleanup();
1989 fuse_sysfs_cleanup();
1990 fuse_fs_cleanup();
1991 fuse_dev_cleanup();
1992}
1993
1994module_init(fuse_init);
1995module_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 max_user_bgreq;
39module_param_call(max_user_bgreq, set_global_limit, param_get_uint,
40 &max_user_bgreq, 0644);
41__MODULE_PARM_TYPE(max_user_bgreq, "uint");
42MODULE_PARM_DESC(max_user_bgreq,
43 "Global limit for the maximum number of backgrounded requests an "
44 "unprivileged user can set");
45
46unsigned max_user_congthresh;
47module_param_call(max_user_congthresh, set_global_limit, param_get_uint,
48 &max_user_congthresh, 0644);
49__MODULE_PARM_TYPE(max_user_congthresh, "uint");
50MODULE_PARM_DESC(max_user_congthresh,
51 "Global limit for the maximum congestion threshold an "
52 "unprivileged user can set");
53
54#define FUSE_DEFAULT_BLKSIZE 512
55
56/** Maximum number of outstanding background requests */
57#define FUSE_DEFAULT_MAX_BACKGROUND 12
58
59/** Congestion starts at 75% of maximum */
60#define FUSE_DEFAULT_CONGESTION_THRESHOLD (FUSE_DEFAULT_MAX_BACKGROUND * 3 / 4)
61
62#ifdef CONFIG_BLOCK
63static struct file_system_type fuseblk_fs_type;
64#endif
65
66struct fuse_forget_link *fuse_alloc_forget(void)
67{
68 return kzalloc(sizeof(struct fuse_forget_link), GFP_KERNEL_ACCOUNT);
69}
70
71static struct fuse_submount_lookup *fuse_alloc_submount_lookup(void)
72{
73 struct fuse_submount_lookup *sl;
74
75 sl = kzalloc(sizeof(struct fuse_submount_lookup), GFP_KERNEL_ACCOUNT);
76 if (!sl)
77 return NULL;
78 sl->forget = fuse_alloc_forget();
79 if (!sl->forget)
80 goto out_free;
81
82 return sl;
83
84out_free:
85 kfree(sl);
86 return NULL;
87}
88
89static struct inode *fuse_alloc_inode(struct super_block *sb)
90{
91 struct fuse_inode *fi;
92
93 fi = alloc_inode_sb(sb, fuse_inode_cachep, GFP_KERNEL);
94 if (!fi)
95 return NULL;
96
97 fi->i_time = 0;
98 fi->inval_mask = ~0;
99 fi->nodeid = 0;
100 fi->nlookup = 0;
101 fi->attr_version = 0;
102 fi->orig_ino = 0;
103 fi->state = 0;
104 fi->submount_lookup = NULL;
105 mutex_init(&fi->mutex);
106 spin_lock_init(&fi->lock);
107 fi->forget = fuse_alloc_forget();
108 if (!fi->forget)
109 goto out_free;
110
111 if (IS_ENABLED(CONFIG_FUSE_DAX) && !fuse_dax_inode_alloc(sb, fi))
112 goto out_free_forget;
113
114 if (IS_ENABLED(CONFIG_FUSE_PASSTHROUGH))
115 fuse_inode_backing_set(fi, NULL);
116
117 return &fi->inode;
118
119out_free_forget:
120 kfree(fi->forget);
121out_free:
122 kmem_cache_free(fuse_inode_cachep, fi);
123 return NULL;
124}
125
126static void fuse_free_inode(struct inode *inode)
127{
128 struct fuse_inode *fi = get_fuse_inode(inode);
129
130 mutex_destroy(&fi->mutex);
131 kfree(fi->forget);
132#ifdef CONFIG_FUSE_DAX
133 kfree(fi->dax);
134#endif
135 if (IS_ENABLED(CONFIG_FUSE_PASSTHROUGH))
136 fuse_backing_put(fuse_inode_backing(fi));
137
138 kmem_cache_free(fuse_inode_cachep, fi);
139}
140
141static void fuse_cleanup_submount_lookup(struct fuse_conn *fc,
142 struct fuse_submount_lookup *sl)
143{
144 if (!refcount_dec_and_test(&sl->count))
145 return;
146
147 fuse_queue_forget(fc, sl->forget, sl->nodeid, 1);
148 sl->forget = NULL;
149 kfree(sl);
150}
151
152static void fuse_evict_inode(struct inode *inode)
153{
154 struct fuse_inode *fi = get_fuse_inode(inode);
155
156 /* Will write inode on close/munmap and in all other dirtiers */
157 WARN_ON(inode->i_state & I_DIRTY_INODE);
158
159 truncate_inode_pages_final(&inode->i_data);
160 clear_inode(inode);
161 if (inode->i_sb->s_flags & SB_ACTIVE) {
162 struct fuse_conn *fc = get_fuse_conn(inode);
163
164 if (FUSE_IS_DAX(inode))
165 fuse_dax_inode_cleanup(inode);
166 if (fi->nlookup) {
167 fuse_queue_forget(fc, fi->forget, fi->nodeid,
168 fi->nlookup);
169 fi->forget = NULL;
170 }
171
172 if (fi->submount_lookup) {
173 fuse_cleanup_submount_lookup(fc, fi->submount_lookup);
174 fi->submount_lookup = NULL;
175 }
176 }
177 if (S_ISREG(inode->i_mode) && !fuse_is_bad(inode)) {
178 WARN_ON(fi->iocachectr != 0);
179 WARN_ON(!list_empty(&fi->write_files));
180 WARN_ON(!list_empty(&fi->queued_writes));
181 }
182}
183
184static int fuse_reconfigure(struct fs_context *fsc)
185{
186 struct super_block *sb = fsc->root->d_sb;
187
188 sync_filesystem(sb);
189 if (fsc->sb_flags & SB_MANDLOCK)
190 return -EINVAL;
191
192 return 0;
193}
194
195/*
196 * ino_t is 32-bits on 32-bit arch. We have to squash the 64-bit value down
197 * so that it will fit.
198 */
199static ino_t fuse_squash_ino(u64 ino64)
200{
201 ino_t ino = (ino_t) ino64;
202 if (sizeof(ino_t) < sizeof(u64))
203 ino ^= ino64 >> (sizeof(u64) - sizeof(ino_t)) * 8;
204 return ino;
205}
206
207void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
208 struct fuse_statx *sx,
209 u64 attr_valid, u32 cache_mask)
210{
211 struct fuse_conn *fc = get_fuse_conn(inode);
212 struct fuse_inode *fi = get_fuse_inode(inode);
213
214 lockdep_assert_held(&fi->lock);
215
216 fi->attr_version = atomic64_inc_return(&fc->attr_version);
217 fi->i_time = attr_valid;
218 /* Clear basic stats from invalid mask */
219 set_mask_bits(&fi->inval_mask, STATX_BASIC_STATS, 0);
220
221 inode->i_ino = fuse_squash_ino(attr->ino);
222 inode->i_mode = (inode->i_mode & S_IFMT) | (attr->mode & 07777);
223 set_nlink(inode, attr->nlink);
224 inode->i_uid = make_kuid(fc->user_ns, attr->uid);
225 inode->i_gid = make_kgid(fc->user_ns, attr->gid);
226 inode->i_blocks = attr->blocks;
227
228 /* Sanitize nsecs */
229 attr->atimensec = min_t(u32, attr->atimensec, NSEC_PER_SEC - 1);
230 attr->mtimensec = min_t(u32, attr->mtimensec, NSEC_PER_SEC - 1);
231 attr->ctimensec = min_t(u32, attr->ctimensec, NSEC_PER_SEC - 1);
232
233 inode_set_atime(inode, attr->atime, attr->atimensec);
234 /* mtime from server may be stale due to local buffered write */
235 if (!(cache_mask & STATX_MTIME)) {
236 inode_set_mtime(inode, attr->mtime, attr->mtimensec);
237 }
238 if (!(cache_mask & STATX_CTIME)) {
239 inode_set_ctime(inode, attr->ctime, attr->ctimensec);
240 }
241 if (sx) {
242 /* Sanitize nsecs */
243 sx->btime.tv_nsec =
244 min_t(u32, sx->btime.tv_nsec, NSEC_PER_SEC - 1);
245
246 /*
247 * Btime has been queried, cache is valid (whether or not btime
248 * is available or not) so clear STATX_BTIME from inval_mask.
249 *
250 * Availability of the btime attribute is indicated in
251 * FUSE_I_BTIME
252 */
253 set_mask_bits(&fi->inval_mask, STATX_BTIME, 0);
254 if (sx->mask & STATX_BTIME) {
255 set_bit(FUSE_I_BTIME, &fi->state);
256 fi->i_btime.tv_sec = sx->btime.tv_sec;
257 fi->i_btime.tv_nsec = sx->btime.tv_nsec;
258 }
259 }
260
261 if (attr->blksize != 0)
262 inode->i_blkbits = ilog2(attr->blksize);
263 else
264 inode->i_blkbits = inode->i_sb->s_blocksize_bits;
265
266 /*
267 * Don't set the sticky bit in i_mode, unless we want the VFS
268 * to check permissions. This prevents failures due to the
269 * check in may_delete().
270 */
271 fi->orig_i_mode = inode->i_mode;
272 if (!fc->default_permissions)
273 inode->i_mode &= ~S_ISVTX;
274
275 fi->orig_ino = attr->ino;
276
277 /*
278 * We are refreshing inode data and it is possible that another
279 * client set suid/sgid or security.capability xattr. So clear
280 * S_NOSEC. Ideally, we could have cleared it only if suid/sgid
281 * was set or if security.capability xattr was set. But we don't
282 * know if security.capability has been set or not. So clear it
283 * anyway. Its less efficient but should be safe.
284 */
285 inode->i_flags &= ~S_NOSEC;
286}
287
288u32 fuse_get_cache_mask(struct inode *inode)
289{
290 struct fuse_conn *fc = get_fuse_conn(inode);
291
292 if (!fc->writeback_cache || !S_ISREG(inode->i_mode))
293 return 0;
294
295 return STATX_MTIME | STATX_CTIME | STATX_SIZE;
296}
297
298void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
299 struct fuse_statx *sx,
300 u64 attr_valid, u64 attr_version)
301{
302 struct fuse_conn *fc = get_fuse_conn(inode);
303 struct fuse_inode *fi = get_fuse_inode(inode);
304 u32 cache_mask;
305 loff_t oldsize;
306 struct timespec64 old_mtime;
307
308 spin_lock(&fi->lock);
309 /*
310 * In case of writeback_cache enabled, writes update mtime, ctime and
311 * may update i_size. In these cases trust the cached value in the
312 * inode.
313 */
314 cache_mask = fuse_get_cache_mask(inode);
315 if (cache_mask & STATX_SIZE)
316 attr->size = i_size_read(inode);
317
318 if (cache_mask & STATX_MTIME) {
319 attr->mtime = inode_get_mtime_sec(inode);
320 attr->mtimensec = inode_get_mtime_nsec(inode);
321 }
322 if (cache_mask & STATX_CTIME) {
323 attr->ctime = inode_get_ctime_sec(inode);
324 attr->ctimensec = inode_get_ctime_nsec(inode);
325 }
326
327 if ((attr_version != 0 && fi->attr_version > attr_version) ||
328 test_bit(FUSE_I_SIZE_UNSTABLE, &fi->state)) {
329 spin_unlock(&fi->lock);
330 return;
331 }
332
333 old_mtime = inode_get_mtime(inode);
334 fuse_change_attributes_common(inode, attr, sx, attr_valid, cache_mask);
335
336 oldsize = inode->i_size;
337 /*
338 * In case of writeback_cache enabled, the cached writes beyond EOF
339 * extend local i_size without keeping userspace server in sync. So,
340 * attr->size coming from server can be stale. We cannot trust it.
341 */
342 if (!(cache_mask & STATX_SIZE))
343 i_size_write(inode, attr->size);
344 spin_unlock(&fi->lock);
345
346 if (!cache_mask && S_ISREG(inode->i_mode)) {
347 bool inval = false;
348
349 if (oldsize != attr->size) {
350 truncate_pagecache(inode, attr->size);
351 if (!fc->explicit_inval_data)
352 inval = true;
353 } else if (fc->auto_inval_data) {
354 struct timespec64 new_mtime = {
355 .tv_sec = attr->mtime,
356 .tv_nsec = attr->mtimensec,
357 };
358
359 /*
360 * Auto inval mode also checks and invalidates if mtime
361 * has changed.
362 */
363 if (!timespec64_equal(&old_mtime, &new_mtime))
364 inval = true;
365 }
366
367 if (inval)
368 invalidate_inode_pages2(inode->i_mapping);
369 }
370
371 if (IS_ENABLED(CONFIG_FUSE_DAX))
372 fuse_dax_dontcache(inode, attr->flags);
373}
374
375static void fuse_init_submount_lookup(struct fuse_submount_lookup *sl,
376 u64 nodeid)
377{
378 sl->nodeid = nodeid;
379 refcount_set(&sl->count, 1);
380}
381
382static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr,
383 struct fuse_conn *fc)
384{
385 inode->i_mode = attr->mode & S_IFMT;
386 inode->i_size = attr->size;
387 inode_set_mtime(inode, attr->mtime, attr->mtimensec);
388 inode_set_ctime(inode, attr->ctime, attr->ctimensec);
389 if (S_ISREG(inode->i_mode)) {
390 fuse_init_common(inode);
391 fuse_init_file_inode(inode, attr->flags);
392 } else if (S_ISDIR(inode->i_mode))
393 fuse_init_dir(inode);
394 else if (S_ISLNK(inode->i_mode))
395 fuse_init_symlink(inode);
396 else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
397 S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
398 fuse_init_common(inode);
399 init_special_inode(inode, inode->i_mode,
400 new_decode_dev(attr->rdev));
401 } else
402 BUG();
403 /*
404 * Ensure that we don't cache acls for daemons without FUSE_POSIX_ACL
405 * so they see the exact same behavior as before.
406 */
407 if (!fc->posix_acl)
408 inode->i_acl = inode->i_default_acl = ACL_DONT_CACHE;
409}
410
411static int fuse_inode_eq(struct inode *inode, void *_nodeidp)
412{
413 u64 nodeid = *(u64 *) _nodeidp;
414 if (get_node_id(inode) == nodeid)
415 return 1;
416 else
417 return 0;
418}
419
420static int fuse_inode_set(struct inode *inode, void *_nodeidp)
421{
422 u64 nodeid = *(u64 *) _nodeidp;
423 get_fuse_inode(inode)->nodeid = nodeid;
424 return 0;
425}
426
427struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
428 int generation, struct fuse_attr *attr,
429 u64 attr_valid, u64 attr_version)
430{
431 struct inode *inode;
432 struct fuse_inode *fi;
433 struct fuse_conn *fc = get_fuse_conn_super(sb);
434
435 /*
436 * Auto mount points get their node id from the submount root, which is
437 * not a unique identifier within this filesystem.
438 *
439 * To avoid conflicts, do not place submount points into the inode hash
440 * table.
441 */
442 if (fc->auto_submounts && (attr->flags & FUSE_ATTR_SUBMOUNT) &&
443 S_ISDIR(attr->mode)) {
444 struct fuse_inode *fi;
445
446 inode = new_inode(sb);
447 if (!inode)
448 return NULL;
449
450 fuse_init_inode(inode, attr, fc);
451 fi = get_fuse_inode(inode);
452 fi->nodeid = nodeid;
453 fi->submount_lookup = fuse_alloc_submount_lookup();
454 if (!fi->submount_lookup) {
455 iput(inode);
456 return NULL;
457 }
458 /* Sets nlookup = 1 on fi->submount_lookup->nlookup */
459 fuse_init_submount_lookup(fi->submount_lookup, nodeid);
460 inode->i_flags |= S_AUTOMOUNT;
461 goto done;
462 }
463
464retry:
465 inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid);
466 if (!inode)
467 return NULL;
468
469 if ((inode->i_state & I_NEW)) {
470 inode->i_flags |= S_NOATIME;
471 if (!fc->writeback_cache || !S_ISREG(attr->mode))
472 inode->i_flags |= S_NOCMTIME;
473 inode->i_generation = generation;
474 fuse_init_inode(inode, attr, fc);
475 unlock_new_inode(inode);
476 } else if (fuse_stale_inode(inode, generation, attr)) {
477 /* nodeid was reused, any I/O on the old inode should fail */
478 fuse_make_bad(inode);
479 if (inode != d_inode(sb->s_root)) {
480 remove_inode_hash(inode);
481 iput(inode);
482 goto retry;
483 }
484 }
485 fi = get_fuse_inode(inode);
486 spin_lock(&fi->lock);
487 fi->nlookup++;
488 spin_unlock(&fi->lock);
489done:
490 fuse_change_attributes(inode, attr, NULL, attr_valid, attr_version);
491
492 return inode;
493}
494
495struct inode *fuse_ilookup(struct fuse_conn *fc, u64 nodeid,
496 struct fuse_mount **fm)
497{
498 struct fuse_mount *fm_iter;
499 struct inode *inode;
500
501 WARN_ON(!rwsem_is_locked(&fc->killsb));
502 list_for_each_entry(fm_iter, &fc->mounts, fc_entry) {
503 if (!fm_iter->sb)
504 continue;
505
506 inode = ilookup5(fm_iter->sb, nodeid, fuse_inode_eq, &nodeid);
507 if (inode) {
508 if (fm)
509 *fm = fm_iter;
510 return inode;
511 }
512 }
513
514 return NULL;
515}
516
517int fuse_reverse_inval_inode(struct fuse_conn *fc, u64 nodeid,
518 loff_t offset, loff_t len)
519{
520 struct fuse_inode *fi;
521 struct inode *inode;
522 pgoff_t pg_start;
523 pgoff_t pg_end;
524
525 inode = fuse_ilookup(fc, nodeid, NULL);
526 if (!inode)
527 return -ENOENT;
528
529 fi = get_fuse_inode(inode);
530 spin_lock(&fi->lock);
531 fi->attr_version = atomic64_inc_return(&fc->attr_version);
532 spin_unlock(&fi->lock);
533
534 fuse_invalidate_attr(inode);
535 forget_all_cached_acls(inode);
536 if (offset >= 0) {
537 pg_start = offset >> PAGE_SHIFT;
538 if (len <= 0)
539 pg_end = -1;
540 else
541 pg_end = (offset + len - 1) >> PAGE_SHIFT;
542 invalidate_inode_pages2_range(inode->i_mapping,
543 pg_start, pg_end);
544 }
545 iput(inode);
546 return 0;
547}
548
549bool fuse_lock_inode(struct inode *inode)
550{
551 bool locked = false;
552
553 if (!get_fuse_conn(inode)->parallel_dirops) {
554 mutex_lock(&get_fuse_inode(inode)->mutex);
555 locked = true;
556 }
557
558 return locked;
559}
560
561void fuse_unlock_inode(struct inode *inode, bool locked)
562{
563 if (locked)
564 mutex_unlock(&get_fuse_inode(inode)->mutex);
565}
566
567static void fuse_umount_begin(struct super_block *sb)
568{
569 struct fuse_conn *fc = get_fuse_conn_super(sb);
570
571 if (fc->no_force_umount)
572 return;
573
574 fuse_abort_conn(fc);
575
576 // Only retire block-device-based superblocks.
577 if (sb->s_bdev != NULL)
578 retire_super(sb);
579}
580
581static void fuse_send_destroy(struct fuse_mount *fm)
582{
583 if (fm->fc->conn_init) {
584 FUSE_ARGS(args);
585
586 args.opcode = FUSE_DESTROY;
587 args.force = true;
588 args.nocreds = true;
589 fuse_simple_request(fm, &args);
590 }
591}
592
593static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
594{
595 stbuf->f_type = FUSE_SUPER_MAGIC;
596 stbuf->f_bsize = attr->bsize;
597 stbuf->f_frsize = attr->frsize;
598 stbuf->f_blocks = attr->blocks;
599 stbuf->f_bfree = attr->bfree;
600 stbuf->f_bavail = attr->bavail;
601 stbuf->f_files = attr->files;
602 stbuf->f_ffree = attr->ffree;
603 stbuf->f_namelen = attr->namelen;
604 /* fsid is left zero */
605}
606
607static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf)
608{
609 struct super_block *sb = dentry->d_sb;
610 struct fuse_mount *fm = get_fuse_mount_super(sb);
611 FUSE_ARGS(args);
612 struct fuse_statfs_out outarg;
613 int err;
614
615 if (!fuse_allow_current_process(fm->fc)) {
616 buf->f_type = FUSE_SUPER_MAGIC;
617 return 0;
618 }
619
620 memset(&outarg, 0, sizeof(outarg));
621 args.in_numargs = 0;
622 args.opcode = FUSE_STATFS;
623 args.nodeid = get_node_id(d_inode(dentry));
624 args.out_numargs = 1;
625 args.out_args[0].size = sizeof(outarg);
626 args.out_args[0].value = &outarg;
627 err = fuse_simple_request(fm, &args);
628 if (!err)
629 convert_fuse_statfs(buf, &outarg.st);
630 return err;
631}
632
633static struct fuse_sync_bucket *fuse_sync_bucket_alloc(void)
634{
635 struct fuse_sync_bucket *bucket;
636
637 bucket = kzalloc(sizeof(*bucket), GFP_KERNEL | __GFP_NOFAIL);
638 if (bucket) {
639 init_waitqueue_head(&bucket->waitq);
640 /* Initial active count */
641 atomic_set(&bucket->count, 1);
642 }
643 return bucket;
644}
645
646static void fuse_sync_fs_writes(struct fuse_conn *fc)
647{
648 struct fuse_sync_bucket *bucket, *new_bucket;
649 int count;
650
651 new_bucket = fuse_sync_bucket_alloc();
652 spin_lock(&fc->lock);
653 bucket = rcu_dereference_protected(fc->curr_bucket, 1);
654 count = atomic_read(&bucket->count);
655 WARN_ON(count < 1);
656 /* No outstanding writes? */
657 if (count == 1) {
658 spin_unlock(&fc->lock);
659 kfree(new_bucket);
660 return;
661 }
662
663 /*
664 * Completion of new bucket depends on completion of this bucket, so add
665 * one more count.
666 */
667 atomic_inc(&new_bucket->count);
668 rcu_assign_pointer(fc->curr_bucket, new_bucket);
669 spin_unlock(&fc->lock);
670 /*
671 * Drop initial active count. At this point if all writes in this and
672 * ancestor buckets complete, the count will go to zero and this task
673 * will be woken up.
674 */
675 atomic_dec(&bucket->count);
676
677 wait_event(bucket->waitq, atomic_read(&bucket->count) == 0);
678
679 /* Drop temp count on descendant bucket */
680 fuse_sync_bucket_dec(new_bucket);
681 kfree_rcu(bucket, rcu);
682}
683
684static int fuse_sync_fs(struct super_block *sb, int wait)
685{
686 struct fuse_mount *fm = get_fuse_mount_super(sb);
687 struct fuse_conn *fc = fm->fc;
688 struct fuse_syncfs_in inarg;
689 FUSE_ARGS(args);
690 int err;
691
692 /*
693 * Userspace cannot handle the wait == 0 case. Avoid a
694 * gratuitous roundtrip.
695 */
696 if (!wait)
697 return 0;
698
699 /* The filesystem is being unmounted. Nothing to do. */
700 if (!sb->s_root)
701 return 0;
702
703 if (!fc->sync_fs)
704 return 0;
705
706 fuse_sync_fs_writes(fc);
707
708 memset(&inarg, 0, sizeof(inarg));
709 args.in_numargs = 1;
710 args.in_args[0].size = sizeof(inarg);
711 args.in_args[0].value = &inarg;
712 args.opcode = FUSE_SYNCFS;
713 args.nodeid = get_node_id(sb->s_root->d_inode);
714 args.out_numargs = 0;
715
716 err = fuse_simple_request(fm, &args);
717 if (err == -ENOSYS) {
718 fc->sync_fs = 0;
719 err = 0;
720 }
721
722 return err;
723}
724
725enum {
726 OPT_SOURCE,
727 OPT_SUBTYPE,
728 OPT_FD,
729 OPT_ROOTMODE,
730 OPT_USER_ID,
731 OPT_GROUP_ID,
732 OPT_DEFAULT_PERMISSIONS,
733 OPT_ALLOW_OTHER,
734 OPT_MAX_READ,
735 OPT_BLKSIZE,
736 OPT_ERR
737};
738
739static const struct fs_parameter_spec fuse_fs_parameters[] = {
740 fsparam_string ("source", OPT_SOURCE),
741 fsparam_u32 ("fd", OPT_FD),
742 fsparam_u32oct ("rootmode", OPT_ROOTMODE),
743 fsparam_u32 ("user_id", OPT_USER_ID),
744 fsparam_u32 ("group_id", OPT_GROUP_ID),
745 fsparam_flag ("default_permissions", OPT_DEFAULT_PERMISSIONS),
746 fsparam_flag ("allow_other", OPT_ALLOW_OTHER),
747 fsparam_u32 ("max_read", OPT_MAX_READ),
748 fsparam_u32 ("blksize", OPT_BLKSIZE),
749 fsparam_string ("subtype", OPT_SUBTYPE),
750 {}
751};
752
753static int fuse_parse_param(struct fs_context *fsc, struct fs_parameter *param)
754{
755 struct fs_parse_result result;
756 struct fuse_fs_context *ctx = fsc->fs_private;
757 int opt;
758
759 if (fsc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
760 /*
761 * Ignore options coming from mount(MS_REMOUNT) for backward
762 * compatibility.
763 */
764 if (fsc->oldapi)
765 return 0;
766
767 return invalfc(fsc, "No changes allowed in reconfigure");
768 }
769
770 opt = fs_parse(fsc, fuse_fs_parameters, param, &result);
771 if (opt < 0)
772 return opt;
773
774 switch (opt) {
775 case OPT_SOURCE:
776 if (fsc->source)
777 return invalfc(fsc, "Multiple sources specified");
778 fsc->source = param->string;
779 param->string = NULL;
780 break;
781
782 case OPT_SUBTYPE:
783 if (ctx->subtype)
784 return invalfc(fsc, "Multiple subtypes specified");
785 ctx->subtype = param->string;
786 param->string = NULL;
787 return 0;
788
789 case OPT_FD:
790 ctx->fd = result.uint_32;
791 ctx->fd_present = true;
792 break;
793
794 case OPT_ROOTMODE:
795 if (!fuse_valid_type(result.uint_32))
796 return invalfc(fsc, "Invalid rootmode");
797 ctx->rootmode = result.uint_32;
798 ctx->rootmode_present = true;
799 break;
800
801 case OPT_USER_ID:
802 ctx->user_id = make_kuid(fsc->user_ns, result.uint_32);
803 if (!uid_valid(ctx->user_id))
804 return invalfc(fsc, "Invalid user_id");
805 ctx->user_id_present = true;
806 break;
807
808 case OPT_GROUP_ID:
809 ctx->group_id = make_kgid(fsc->user_ns, result.uint_32);
810 if (!gid_valid(ctx->group_id))
811 return invalfc(fsc, "Invalid group_id");
812 ctx->group_id_present = true;
813 break;
814
815 case OPT_DEFAULT_PERMISSIONS:
816 ctx->default_permissions = true;
817 break;
818
819 case OPT_ALLOW_OTHER:
820 ctx->allow_other = true;
821 break;
822
823 case OPT_MAX_READ:
824 ctx->max_read = result.uint_32;
825 break;
826
827 case OPT_BLKSIZE:
828 if (!ctx->is_bdev)
829 return invalfc(fsc, "blksize only supported for fuseblk");
830 ctx->blksize = result.uint_32;
831 break;
832
833 default:
834 return -EINVAL;
835 }
836
837 return 0;
838}
839
840static void fuse_free_fsc(struct fs_context *fsc)
841{
842 struct fuse_fs_context *ctx = fsc->fs_private;
843
844 if (ctx) {
845 kfree(ctx->subtype);
846 kfree(ctx);
847 }
848}
849
850static int fuse_show_options(struct seq_file *m, struct dentry *root)
851{
852 struct super_block *sb = root->d_sb;
853 struct fuse_conn *fc = get_fuse_conn_super(sb);
854
855 if (fc->legacy_opts_show) {
856 seq_printf(m, ",user_id=%u",
857 from_kuid_munged(fc->user_ns, fc->user_id));
858 seq_printf(m, ",group_id=%u",
859 from_kgid_munged(fc->user_ns, fc->group_id));
860 if (fc->default_permissions)
861 seq_puts(m, ",default_permissions");
862 if (fc->allow_other)
863 seq_puts(m, ",allow_other");
864 if (fc->max_read != ~0)
865 seq_printf(m, ",max_read=%u", fc->max_read);
866 if (sb->s_bdev && sb->s_blocksize != FUSE_DEFAULT_BLKSIZE)
867 seq_printf(m, ",blksize=%lu", sb->s_blocksize);
868 }
869#ifdef CONFIG_FUSE_DAX
870 if (fc->dax_mode == FUSE_DAX_ALWAYS)
871 seq_puts(m, ",dax=always");
872 else if (fc->dax_mode == FUSE_DAX_NEVER)
873 seq_puts(m, ",dax=never");
874 else if (fc->dax_mode == FUSE_DAX_INODE_USER)
875 seq_puts(m, ",dax=inode");
876#endif
877
878 return 0;
879}
880
881static void fuse_iqueue_init(struct fuse_iqueue *fiq,
882 const struct fuse_iqueue_ops *ops,
883 void *priv)
884{
885 memset(fiq, 0, sizeof(struct fuse_iqueue));
886 spin_lock_init(&fiq->lock);
887 init_waitqueue_head(&fiq->waitq);
888 INIT_LIST_HEAD(&fiq->pending);
889 INIT_LIST_HEAD(&fiq->interrupts);
890 fiq->forget_list_tail = &fiq->forget_list_head;
891 fiq->connected = 1;
892 fiq->ops = ops;
893 fiq->priv = priv;
894}
895
896static void fuse_pqueue_init(struct fuse_pqueue *fpq)
897{
898 unsigned int i;
899
900 spin_lock_init(&fpq->lock);
901 for (i = 0; i < FUSE_PQ_HASH_SIZE; i++)
902 INIT_LIST_HEAD(&fpq->processing[i]);
903 INIT_LIST_HEAD(&fpq->io);
904 fpq->connected = 1;
905}
906
907void fuse_conn_init(struct fuse_conn *fc, struct fuse_mount *fm,
908 struct user_namespace *user_ns,
909 const struct fuse_iqueue_ops *fiq_ops, void *fiq_priv)
910{
911 memset(fc, 0, sizeof(*fc));
912 spin_lock_init(&fc->lock);
913 spin_lock_init(&fc->bg_lock);
914 init_rwsem(&fc->killsb);
915 refcount_set(&fc->count, 1);
916 atomic_set(&fc->dev_count, 1);
917 init_waitqueue_head(&fc->blocked_waitq);
918 fuse_iqueue_init(&fc->iq, fiq_ops, fiq_priv);
919 INIT_LIST_HEAD(&fc->bg_queue);
920 INIT_LIST_HEAD(&fc->entry);
921 INIT_LIST_HEAD(&fc->devices);
922 atomic_set(&fc->num_waiting, 0);
923 fc->max_background = FUSE_DEFAULT_MAX_BACKGROUND;
924 fc->congestion_threshold = FUSE_DEFAULT_CONGESTION_THRESHOLD;
925 atomic64_set(&fc->khctr, 0);
926 fc->polled_files = RB_ROOT;
927 fc->blocked = 0;
928 fc->initialized = 0;
929 fc->connected = 1;
930 atomic64_set(&fc->attr_version, 1);
931 get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key));
932 fc->pid_ns = get_pid_ns(task_active_pid_ns(current));
933 fc->user_ns = get_user_ns(user_ns);
934 fc->max_pages = FUSE_DEFAULT_MAX_PAGES_PER_REQ;
935 fc->max_pages_limit = FUSE_MAX_MAX_PAGES;
936
937 if (IS_ENABLED(CONFIG_FUSE_PASSTHROUGH))
938 fuse_backing_files_init(fc);
939
940 INIT_LIST_HEAD(&fc->mounts);
941 list_add(&fm->fc_entry, &fc->mounts);
942 fm->fc = fc;
943}
944EXPORT_SYMBOL_GPL(fuse_conn_init);
945
946static void delayed_release(struct rcu_head *p)
947{
948 struct fuse_conn *fc = container_of(p, struct fuse_conn, rcu);
949
950 put_user_ns(fc->user_ns);
951 fc->release(fc);
952}
953
954void fuse_conn_put(struct fuse_conn *fc)
955{
956 if (refcount_dec_and_test(&fc->count)) {
957 struct fuse_iqueue *fiq = &fc->iq;
958 struct fuse_sync_bucket *bucket;
959
960 if (IS_ENABLED(CONFIG_FUSE_DAX))
961 fuse_dax_conn_free(fc);
962 if (fiq->ops->release)
963 fiq->ops->release(fiq);
964 put_pid_ns(fc->pid_ns);
965 bucket = rcu_dereference_protected(fc->curr_bucket, 1);
966 if (bucket) {
967 WARN_ON(atomic_read(&bucket->count) != 1);
968 kfree(bucket);
969 }
970 if (IS_ENABLED(CONFIG_FUSE_PASSTHROUGH))
971 fuse_backing_files_free(fc);
972 call_rcu(&fc->rcu, delayed_release);
973 }
974}
975EXPORT_SYMBOL_GPL(fuse_conn_put);
976
977struct fuse_conn *fuse_conn_get(struct fuse_conn *fc)
978{
979 refcount_inc(&fc->count);
980 return fc;
981}
982EXPORT_SYMBOL_GPL(fuse_conn_get);
983
984static struct inode *fuse_get_root_inode(struct super_block *sb, unsigned mode)
985{
986 struct fuse_attr attr;
987 memset(&attr, 0, sizeof(attr));
988
989 attr.mode = mode;
990 attr.ino = FUSE_ROOT_ID;
991 attr.nlink = 1;
992 return fuse_iget(sb, FUSE_ROOT_ID, 0, &attr, 0, 0);
993}
994
995struct fuse_inode_handle {
996 u64 nodeid;
997 u32 generation;
998};
999
1000static struct dentry *fuse_get_dentry(struct super_block *sb,
1001 struct fuse_inode_handle *handle)
1002{
1003 struct fuse_conn *fc = get_fuse_conn_super(sb);
1004 struct inode *inode;
1005 struct dentry *entry;
1006 int err = -ESTALE;
1007
1008 if (handle->nodeid == 0)
1009 goto out_err;
1010
1011 inode = ilookup5(sb, handle->nodeid, fuse_inode_eq, &handle->nodeid);
1012 if (!inode) {
1013 struct fuse_entry_out outarg;
1014 const struct qstr name = QSTR_INIT(".", 1);
1015
1016 if (!fc->export_support)
1017 goto out_err;
1018
1019 err = fuse_lookup_name(sb, handle->nodeid, &name, &outarg,
1020 &inode);
1021 if (err && err != -ENOENT)
1022 goto out_err;
1023 if (err || !inode) {
1024 err = -ESTALE;
1025 goto out_err;
1026 }
1027 err = -EIO;
1028 if (get_node_id(inode) != handle->nodeid)
1029 goto out_iput;
1030 }
1031 err = -ESTALE;
1032 if (inode->i_generation != handle->generation)
1033 goto out_iput;
1034
1035 entry = d_obtain_alias(inode);
1036 if (!IS_ERR(entry) && get_node_id(inode) != FUSE_ROOT_ID)
1037 fuse_invalidate_entry_cache(entry);
1038
1039 return entry;
1040
1041 out_iput:
1042 iput(inode);
1043 out_err:
1044 return ERR_PTR(err);
1045}
1046
1047static int fuse_encode_fh(struct inode *inode, u32 *fh, int *max_len,
1048 struct inode *parent)
1049{
1050 int len = parent ? 6 : 3;
1051 u64 nodeid;
1052 u32 generation;
1053
1054 if (*max_len < len) {
1055 *max_len = len;
1056 return FILEID_INVALID;
1057 }
1058
1059 nodeid = get_fuse_inode(inode)->nodeid;
1060 generation = inode->i_generation;
1061
1062 fh[0] = (u32)(nodeid >> 32);
1063 fh[1] = (u32)(nodeid & 0xffffffff);
1064 fh[2] = generation;
1065
1066 if (parent) {
1067 nodeid = get_fuse_inode(parent)->nodeid;
1068 generation = parent->i_generation;
1069
1070 fh[3] = (u32)(nodeid >> 32);
1071 fh[4] = (u32)(nodeid & 0xffffffff);
1072 fh[5] = generation;
1073 }
1074
1075 *max_len = len;
1076 return parent ? FILEID_INO64_GEN_PARENT : FILEID_INO64_GEN;
1077}
1078
1079static struct dentry *fuse_fh_to_dentry(struct super_block *sb,
1080 struct fid *fid, int fh_len, int fh_type)
1081{
1082 struct fuse_inode_handle handle;
1083
1084 if ((fh_type != FILEID_INO64_GEN &&
1085 fh_type != FILEID_INO64_GEN_PARENT) || fh_len < 3)
1086 return NULL;
1087
1088 handle.nodeid = (u64) fid->raw[0] << 32;
1089 handle.nodeid |= (u64) fid->raw[1];
1090 handle.generation = fid->raw[2];
1091 return fuse_get_dentry(sb, &handle);
1092}
1093
1094static struct dentry *fuse_fh_to_parent(struct super_block *sb,
1095 struct fid *fid, int fh_len, int fh_type)
1096{
1097 struct fuse_inode_handle parent;
1098
1099 if (fh_type != FILEID_INO64_GEN_PARENT || fh_len < 6)
1100 return NULL;
1101
1102 parent.nodeid = (u64) fid->raw[3] << 32;
1103 parent.nodeid |= (u64) fid->raw[4];
1104 parent.generation = fid->raw[5];
1105 return fuse_get_dentry(sb, &parent);
1106}
1107
1108static struct dentry *fuse_get_parent(struct dentry *child)
1109{
1110 struct inode *child_inode = d_inode(child);
1111 struct fuse_conn *fc = get_fuse_conn(child_inode);
1112 struct inode *inode;
1113 struct dentry *parent;
1114 struct fuse_entry_out outarg;
1115 int err;
1116
1117 if (!fc->export_support)
1118 return ERR_PTR(-ESTALE);
1119
1120 err = fuse_lookup_name(child_inode->i_sb, get_node_id(child_inode),
1121 &dotdot_name, &outarg, &inode);
1122 if (err) {
1123 if (err == -ENOENT)
1124 return ERR_PTR(-ESTALE);
1125 return ERR_PTR(err);
1126 }
1127
1128 parent = d_obtain_alias(inode);
1129 if (!IS_ERR(parent) && get_node_id(inode) != FUSE_ROOT_ID)
1130 fuse_invalidate_entry_cache(parent);
1131
1132 return parent;
1133}
1134
1135/* only for fid encoding; no support for file handle */
1136static const struct export_operations fuse_export_fid_operations = {
1137 .encode_fh = fuse_encode_fh,
1138};
1139
1140static const struct export_operations fuse_export_operations = {
1141 .fh_to_dentry = fuse_fh_to_dentry,
1142 .fh_to_parent = fuse_fh_to_parent,
1143 .encode_fh = fuse_encode_fh,
1144 .get_parent = fuse_get_parent,
1145};
1146
1147static const struct super_operations fuse_super_operations = {
1148 .alloc_inode = fuse_alloc_inode,
1149 .free_inode = fuse_free_inode,
1150 .evict_inode = fuse_evict_inode,
1151 .write_inode = fuse_write_inode,
1152 .drop_inode = generic_delete_inode,
1153 .umount_begin = fuse_umount_begin,
1154 .statfs = fuse_statfs,
1155 .sync_fs = fuse_sync_fs,
1156 .show_options = fuse_show_options,
1157};
1158
1159static void sanitize_global_limit(unsigned *limit)
1160{
1161 /*
1162 * The default maximum number of async requests is calculated to consume
1163 * 1/2^13 of the total memory, assuming 392 bytes per request.
1164 */
1165 if (*limit == 0)
1166 *limit = ((totalram_pages() << PAGE_SHIFT) >> 13) / 392;
1167
1168 if (*limit >= 1 << 16)
1169 *limit = (1 << 16) - 1;
1170}
1171
1172static int set_global_limit(const char *val, const struct kernel_param *kp)
1173{
1174 int rv;
1175
1176 rv = param_set_uint(val, kp);
1177 if (rv)
1178 return rv;
1179
1180 sanitize_global_limit((unsigned *)kp->arg);
1181
1182 return 0;
1183}
1184
1185static void process_init_limits(struct fuse_conn *fc, struct fuse_init_out *arg)
1186{
1187 int cap_sys_admin = capable(CAP_SYS_ADMIN);
1188
1189 if (arg->minor < 13)
1190 return;
1191
1192 sanitize_global_limit(&max_user_bgreq);
1193 sanitize_global_limit(&max_user_congthresh);
1194
1195 spin_lock(&fc->bg_lock);
1196 if (arg->max_background) {
1197 fc->max_background = arg->max_background;
1198
1199 if (!cap_sys_admin && fc->max_background > max_user_bgreq)
1200 fc->max_background = max_user_bgreq;
1201 }
1202 if (arg->congestion_threshold) {
1203 fc->congestion_threshold = arg->congestion_threshold;
1204
1205 if (!cap_sys_admin &&
1206 fc->congestion_threshold > max_user_congthresh)
1207 fc->congestion_threshold = max_user_congthresh;
1208 }
1209 spin_unlock(&fc->bg_lock);
1210}
1211
1212struct fuse_init_args {
1213 struct fuse_args args;
1214 struct fuse_init_in in;
1215 struct fuse_init_out out;
1216};
1217
1218static void process_init_reply(struct fuse_mount *fm, struct fuse_args *args,
1219 int error)
1220{
1221 struct fuse_conn *fc = fm->fc;
1222 struct fuse_init_args *ia = container_of(args, typeof(*ia), args);
1223 struct fuse_init_out *arg = &ia->out;
1224 bool ok = true;
1225
1226 if (error || arg->major != FUSE_KERNEL_VERSION)
1227 ok = false;
1228 else {
1229 unsigned long ra_pages;
1230
1231 process_init_limits(fc, arg);
1232
1233 if (arg->minor >= 6) {
1234 u64 flags = arg->flags;
1235
1236 if (flags & FUSE_INIT_EXT)
1237 flags |= (u64) arg->flags2 << 32;
1238
1239 ra_pages = arg->max_readahead / PAGE_SIZE;
1240 if (flags & FUSE_ASYNC_READ)
1241 fc->async_read = 1;
1242 if (!(flags & FUSE_POSIX_LOCKS))
1243 fc->no_lock = 1;
1244 if (arg->minor >= 17) {
1245 if (!(flags & FUSE_FLOCK_LOCKS))
1246 fc->no_flock = 1;
1247 } else {
1248 if (!(flags & FUSE_POSIX_LOCKS))
1249 fc->no_flock = 1;
1250 }
1251 if (flags & FUSE_ATOMIC_O_TRUNC)
1252 fc->atomic_o_trunc = 1;
1253 if (arg->minor >= 9) {
1254 /* LOOKUP has dependency on proto version */
1255 if (flags & FUSE_EXPORT_SUPPORT)
1256 fc->export_support = 1;
1257 }
1258 if (flags & FUSE_BIG_WRITES)
1259 fc->big_writes = 1;
1260 if (flags & FUSE_DONT_MASK)
1261 fc->dont_mask = 1;
1262 if (flags & FUSE_AUTO_INVAL_DATA)
1263 fc->auto_inval_data = 1;
1264 else if (flags & FUSE_EXPLICIT_INVAL_DATA)
1265 fc->explicit_inval_data = 1;
1266 if (flags & FUSE_DO_READDIRPLUS) {
1267 fc->do_readdirplus = 1;
1268 if (flags & FUSE_READDIRPLUS_AUTO)
1269 fc->readdirplus_auto = 1;
1270 }
1271 if (flags & FUSE_ASYNC_DIO)
1272 fc->async_dio = 1;
1273 if (flags & FUSE_WRITEBACK_CACHE)
1274 fc->writeback_cache = 1;
1275 if (flags & FUSE_PARALLEL_DIROPS)
1276 fc->parallel_dirops = 1;
1277 if (flags & FUSE_HANDLE_KILLPRIV)
1278 fc->handle_killpriv = 1;
1279 if (arg->time_gran && arg->time_gran <= 1000000000)
1280 fm->sb->s_time_gran = arg->time_gran;
1281 if ((flags & FUSE_POSIX_ACL)) {
1282 fc->default_permissions = 1;
1283 fc->posix_acl = 1;
1284 }
1285 if (flags & FUSE_CACHE_SYMLINKS)
1286 fc->cache_symlinks = 1;
1287 if (flags & FUSE_ABORT_ERROR)
1288 fc->abort_err = 1;
1289 if (flags & FUSE_MAX_PAGES) {
1290 fc->max_pages =
1291 min_t(unsigned int, fc->max_pages_limit,
1292 max_t(unsigned int, arg->max_pages, 1));
1293 }
1294 if (IS_ENABLED(CONFIG_FUSE_DAX)) {
1295 if (flags & FUSE_MAP_ALIGNMENT &&
1296 !fuse_dax_check_alignment(fc, arg->map_alignment)) {
1297 ok = false;
1298 }
1299 if (flags & FUSE_HAS_INODE_DAX)
1300 fc->inode_dax = 1;
1301 }
1302 if (flags & FUSE_HANDLE_KILLPRIV_V2) {
1303 fc->handle_killpriv_v2 = 1;
1304 fm->sb->s_flags |= SB_NOSEC;
1305 }
1306 if (flags & FUSE_SETXATTR_EXT)
1307 fc->setxattr_ext = 1;
1308 if (flags & FUSE_SECURITY_CTX)
1309 fc->init_security = 1;
1310 if (flags & FUSE_CREATE_SUPP_GROUP)
1311 fc->create_supp_group = 1;
1312 if (flags & FUSE_DIRECT_IO_ALLOW_MMAP)
1313 fc->direct_io_allow_mmap = 1;
1314 /*
1315 * max_stack_depth is the max stack depth of FUSE fs,
1316 * so it has to be at least 1 to support passthrough
1317 * to backing files.
1318 *
1319 * with max_stack_depth > 1, the backing files can be
1320 * on a stacked fs (e.g. overlayfs) themselves and with
1321 * max_stack_depth == 1, FUSE fs can be stacked as the
1322 * underlying fs of a stacked fs (e.g. overlayfs).
1323 */
1324 if (IS_ENABLED(CONFIG_FUSE_PASSTHROUGH) &&
1325 (flags & FUSE_PASSTHROUGH) &&
1326 arg->max_stack_depth > 0 &&
1327 arg->max_stack_depth <= FILESYSTEM_MAX_STACK_DEPTH) {
1328 fc->passthrough = 1;
1329 fc->max_stack_depth = arg->max_stack_depth;
1330 fm->sb->s_stack_depth = arg->max_stack_depth;
1331 }
1332 if (flags & FUSE_NO_EXPORT_SUPPORT)
1333 fm->sb->s_export_op = &fuse_export_fid_operations;
1334 } else {
1335 ra_pages = fc->max_read / PAGE_SIZE;
1336 fc->no_lock = 1;
1337 fc->no_flock = 1;
1338 }
1339
1340 fm->sb->s_bdi->ra_pages =
1341 min(fm->sb->s_bdi->ra_pages, ra_pages);
1342 fc->minor = arg->minor;
1343 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
1344 fc->max_write = max_t(unsigned, 4096, fc->max_write);
1345 fc->conn_init = 1;
1346 }
1347 kfree(ia);
1348
1349 if (!ok) {
1350 fc->conn_init = 0;
1351 fc->conn_error = 1;
1352 }
1353
1354 fuse_set_initialized(fc);
1355 wake_up_all(&fc->blocked_waitq);
1356}
1357
1358void fuse_send_init(struct fuse_mount *fm)
1359{
1360 struct fuse_init_args *ia;
1361 u64 flags;
1362
1363 ia = kzalloc(sizeof(*ia), GFP_KERNEL | __GFP_NOFAIL);
1364
1365 ia->in.major = FUSE_KERNEL_VERSION;
1366 ia->in.minor = FUSE_KERNEL_MINOR_VERSION;
1367 ia->in.max_readahead = fm->sb->s_bdi->ra_pages * PAGE_SIZE;
1368 flags =
1369 FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_ATOMIC_O_TRUNC |
1370 FUSE_EXPORT_SUPPORT | FUSE_BIG_WRITES | FUSE_DONT_MASK |
1371 FUSE_SPLICE_WRITE | FUSE_SPLICE_MOVE | FUSE_SPLICE_READ |
1372 FUSE_FLOCK_LOCKS | FUSE_HAS_IOCTL_DIR | FUSE_AUTO_INVAL_DATA |
1373 FUSE_DO_READDIRPLUS | FUSE_READDIRPLUS_AUTO | FUSE_ASYNC_DIO |
1374 FUSE_WRITEBACK_CACHE | FUSE_NO_OPEN_SUPPORT |
1375 FUSE_PARALLEL_DIROPS | FUSE_HANDLE_KILLPRIV | FUSE_POSIX_ACL |
1376 FUSE_ABORT_ERROR | FUSE_MAX_PAGES | FUSE_CACHE_SYMLINKS |
1377 FUSE_NO_OPENDIR_SUPPORT | FUSE_EXPLICIT_INVAL_DATA |
1378 FUSE_HANDLE_KILLPRIV_V2 | FUSE_SETXATTR_EXT | FUSE_INIT_EXT |
1379 FUSE_SECURITY_CTX | FUSE_CREATE_SUPP_GROUP |
1380 FUSE_HAS_EXPIRE_ONLY | FUSE_DIRECT_IO_ALLOW_MMAP |
1381 FUSE_NO_EXPORT_SUPPORT | FUSE_HAS_RESEND;
1382#ifdef CONFIG_FUSE_DAX
1383 if (fm->fc->dax)
1384 flags |= FUSE_MAP_ALIGNMENT;
1385 if (fuse_is_inode_dax_mode(fm->fc->dax_mode))
1386 flags |= FUSE_HAS_INODE_DAX;
1387#endif
1388 if (fm->fc->auto_submounts)
1389 flags |= FUSE_SUBMOUNTS;
1390 if (IS_ENABLED(CONFIG_FUSE_PASSTHROUGH))
1391 flags |= FUSE_PASSTHROUGH;
1392
1393 ia->in.flags = flags;
1394 ia->in.flags2 = flags >> 32;
1395
1396 ia->args.opcode = FUSE_INIT;
1397 ia->args.in_numargs = 1;
1398 ia->args.in_args[0].size = sizeof(ia->in);
1399 ia->args.in_args[0].value = &ia->in;
1400 ia->args.out_numargs = 1;
1401 /* Variable length argument used for backward compatibility
1402 with interface version < 7.5. Rest of init_out is zeroed
1403 by do_get_request(), so a short reply is not a problem */
1404 ia->args.out_argvar = true;
1405 ia->args.out_args[0].size = sizeof(ia->out);
1406 ia->args.out_args[0].value = &ia->out;
1407 ia->args.force = true;
1408 ia->args.nocreds = true;
1409 ia->args.end = process_init_reply;
1410
1411 if (fuse_simple_background(fm, &ia->args, GFP_KERNEL) != 0)
1412 process_init_reply(fm, &ia->args, -ENOTCONN);
1413}
1414EXPORT_SYMBOL_GPL(fuse_send_init);
1415
1416void fuse_free_conn(struct fuse_conn *fc)
1417{
1418 WARN_ON(!list_empty(&fc->devices));
1419 kfree(fc);
1420}
1421EXPORT_SYMBOL_GPL(fuse_free_conn);
1422
1423static int fuse_bdi_init(struct fuse_conn *fc, struct super_block *sb)
1424{
1425 int err;
1426 char *suffix = "";
1427
1428 if (sb->s_bdev) {
1429 suffix = "-fuseblk";
1430 /*
1431 * sb->s_bdi points to blkdev's bdi however we want to redirect
1432 * it to our private bdi...
1433 */
1434 bdi_put(sb->s_bdi);
1435 sb->s_bdi = &noop_backing_dev_info;
1436 }
1437 err = super_setup_bdi_name(sb, "%u:%u%s", MAJOR(fc->dev),
1438 MINOR(fc->dev), suffix);
1439 if (err)
1440 return err;
1441
1442 /* fuse does it's own writeback accounting */
1443 sb->s_bdi->capabilities &= ~BDI_CAP_WRITEBACK_ACCT;
1444 sb->s_bdi->capabilities |= BDI_CAP_STRICTLIMIT;
1445
1446 /*
1447 * For a single fuse filesystem use max 1% of dirty +
1448 * writeback threshold.
1449 *
1450 * This gives about 1M of write buffer for memory maps on a
1451 * machine with 1G and 10% dirty_ratio, which should be more
1452 * than enough.
1453 *
1454 * Privileged users can raise it by writing to
1455 *
1456 * /sys/class/bdi/<bdi>/max_ratio
1457 */
1458 bdi_set_max_ratio(sb->s_bdi, 1);
1459
1460 return 0;
1461}
1462
1463struct fuse_dev *fuse_dev_alloc(void)
1464{
1465 struct fuse_dev *fud;
1466 struct list_head *pq;
1467
1468 fud = kzalloc(sizeof(struct fuse_dev), GFP_KERNEL);
1469 if (!fud)
1470 return NULL;
1471
1472 pq = kcalloc(FUSE_PQ_HASH_SIZE, sizeof(struct list_head), GFP_KERNEL);
1473 if (!pq) {
1474 kfree(fud);
1475 return NULL;
1476 }
1477
1478 fud->pq.processing = pq;
1479 fuse_pqueue_init(&fud->pq);
1480
1481 return fud;
1482}
1483EXPORT_SYMBOL_GPL(fuse_dev_alloc);
1484
1485void fuse_dev_install(struct fuse_dev *fud, struct fuse_conn *fc)
1486{
1487 fud->fc = fuse_conn_get(fc);
1488 spin_lock(&fc->lock);
1489 list_add_tail(&fud->entry, &fc->devices);
1490 spin_unlock(&fc->lock);
1491}
1492EXPORT_SYMBOL_GPL(fuse_dev_install);
1493
1494struct fuse_dev *fuse_dev_alloc_install(struct fuse_conn *fc)
1495{
1496 struct fuse_dev *fud;
1497
1498 fud = fuse_dev_alloc();
1499 if (!fud)
1500 return NULL;
1501
1502 fuse_dev_install(fud, fc);
1503 return fud;
1504}
1505EXPORT_SYMBOL_GPL(fuse_dev_alloc_install);
1506
1507void fuse_dev_free(struct fuse_dev *fud)
1508{
1509 struct fuse_conn *fc = fud->fc;
1510
1511 if (fc) {
1512 spin_lock(&fc->lock);
1513 list_del(&fud->entry);
1514 spin_unlock(&fc->lock);
1515
1516 fuse_conn_put(fc);
1517 }
1518 kfree(fud->pq.processing);
1519 kfree(fud);
1520}
1521EXPORT_SYMBOL_GPL(fuse_dev_free);
1522
1523static void fuse_fill_attr_from_inode(struct fuse_attr *attr,
1524 const struct fuse_inode *fi)
1525{
1526 struct timespec64 atime = inode_get_atime(&fi->inode);
1527 struct timespec64 mtime = inode_get_mtime(&fi->inode);
1528 struct timespec64 ctime = inode_get_ctime(&fi->inode);
1529
1530 *attr = (struct fuse_attr){
1531 .ino = fi->inode.i_ino,
1532 .size = fi->inode.i_size,
1533 .blocks = fi->inode.i_blocks,
1534 .atime = atime.tv_sec,
1535 .mtime = mtime.tv_sec,
1536 .ctime = ctime.tv_sec,
1537 .atimensec = atime.tv_nsec,
1538 .mtimensec = mtime.tv_nsec,
1539 .ctimensec = ctime.tv_nsec,
1540 .mode = fi->inode.i_mode,
1541 .nlink = fi->inode.i_nlink,
1542 .uid = __kuid_val(fi->inode.i_uid),
1543 .gid = __kgid_val(fi->inode.i_gid),
1544 .rdev = fi->inode.i_rdev,
1545 .blksize = 1u << fi->inode.i_blkbits,
1546 };
1547}
1548
1549static void fuse_sb_defaults(struct super_block *sb)
1550{
1551 sb->s_magic = FUSE_SUPER_MAGIC;
1552 sb->s_op = &fuse_super_operations;
1553 sb->s_xattr = fuse_xattr_handlers;
1554 sb->s_maxbytes = MAX_LFS_FILESIZE;
1555 sb->s_time_gran = 1;
1556 sb->s_export_op = &fuse_export_operations;
1557 sb->s_iflags |= SB_I_IMA_UNVERIFIABLE_SIGNATURE;
1558 if (sb->s_user_ns != &init_user_ns)
1559 sb->s_iflags |= SB_I_UNTRUSTED_MOUNTER;
1560 sb->s_flags &= ~(SB_NOSEC | SB_I_VERSION);
1561}
1562
1563static int fuse_fill_super_submount(struct super_block *sb,
1564 struct fuse_inode *parent_fi)
1565{
1566 struct fuse_mount *fm = get_fuse_mount_super(sb);
1567 struct super_block *parent_sb = parent_fi->inode.i_sb;
1568 struct fuse_attr root_attr;
1569 struct inode *root;
1570 struct fuse_submount_lookup *sl;
1571 struct fuse_inode *fi;
1572
1573 fuse_sb_defaults(sb);
1574 fm->sb = sb;
1575
1576 WARN_ON(sb->s_bdi != &noop_backing_dev_info);
1577 sb->s_bdi = bdi_get(parent_sb->s_bdi);
1578
1579 sb->s_xattr = parent_sb->s_xattr;
1580 sb->s_export_op = parent_sb->s_export_op;
1581 sb->s_time_gran = parent_sb->s_time_gran;
1582 sb->s_blocksize = parent_sb->s_blocksize;
1583 sb->s_blocksize_bits = parent_sb->s_blocksize_bits;
1584 sb->s_subtype = kstrdup(parent_sb->s_subtype, GFP_KERNEL);
1585 if (parent_sb->s_subtype && !sb->s_subtype)
1586 return -ENOMEM;
1587
1588 fuse_fill_attr_from_inode(&root_attr, parent_fi);
1589 root = fuse_iget(sb, parent_fi->nodeid, 0, &root_attr, 0, 0);
1590 /*
1591 * This inode is just a duplicate, so it is not looked up and
1592 * its nlookup should not be incremented. fuse_iget() does
1593 * that, though, so undo it here.
1594 */
1595 fi = get_fuse_inode(root);
1596 fi->nlookup--;
1597
1598 sb->s_d_op = &fuse_dentry_operations;
1599 sb->s_root = d_make_root(root);
1600 if (!sb->s_root)
1601 return -ENOMEM;
1602
1603 /*
1604 * Grab the parent's submount_lookup pointer and take a
1605 * reference on the shared nlookup from the parent. This is to
1606 * prevent the last forget for this nodeid from getting
1607 * triggered until all users have finished with it.
1608 */
1609 sl = parent_fi->submount_lookup;
1610 WARN_ON(!sl);
1611 if (sl) {
1612 refcount_inc(&sl->count);
1613 fi->submount_lookup = sl;
1614 }
1615
1616 return 0;
1617}
1618
1619/* Filesystem context private data holds the FUSE inode of the mount point */
1620static int fuse_get_tree_submount(struct fs_context *fsc)
1621{
1622 struct fuse_mount *fm;
1623 struct fuse_inode *mp_fi = fsc->fs_private;
1624 struct fuse_conn *fc = get_fuse_conn(&mp_fi->inode);
1625 struct super_block *sb;
1626 int err;
1627
1628 fm = kzalloc(sizeof(struct fuse_mount), GFP_KERNEL);
1629 if (!fm)
1630 return -ENOMEM;
1631
1632 fm->fc = fuse_conn_get(fc);
1633 fsc->s_fs_info = fm;
1634 sb = sget_fc(fsc, NULL, set_anon_super_fc);
1635 if (fsc->s_fs_info)
1636 fuse_mount_destroy(fm);
1637 if (IS_ERR(sb))
1638 return PTR_ERR(sb);
1639
1640 /* Initialize superblock, making @mp_fi its root */
1641 err = fuse_fill_super_submount(sb, mp_fi);
1642 if (err) {
1643 deactivate_locked_super(sb);
1644 return err;
1645 }
1646
1647 down_write(&fc->killsb);
1648 list_add_tail(&fm->fc_entry, &fc->mounts);
1649 up_write(&fc->killsb);
1650
1651 sb->s_flags |= SB_ACTIVE;
1652 fsc->root = dget(sb->s_root);
1653
1654 return 0;
1655}
1656
1657static const struct fs_context_operations fuse_context_submount_ops = {
1658 .get_tree = fuse_get_tree_submount,
1659};
1660
1661int fuse_init_fs_context_submount(struct fs_context *fsc)
1662{
1663 fsc->ops = &fuse_context_submount_ops;
1664 return 0;
1665}
1666EXPORT_SYMBOL_GPL(fuse_init_fs_context_submount);
1667
1668int fuse_fill_super_common(struct super_block *sb, struct fuse_fs_context *ctx)
1669{
1670 struct fuse_dev *fud = NULL;
1671 struct fuse_mount *fm = get_fuse_mount_super(sb);
1672 struct fuse_conn *fc = fm->fc;
1673 struct inode *root;
1674 struct dentry *root_dentry;
1675 int err;
1676
1677 err = -EINVAL;
1678 if (sb->s_flags & SB_MANDLOCK)
1679 goto err;
1680
1681 rcu_assign_pointer(fc->curr_bucket, fuse_sync_bucket_alloc());
1682 fuse_sb_defaults(sb);
1683
1684 if (ctx->is_bdev) {
1685#ifdef CONFIG_BLOCK
1686 err = -EINVAL;
1687 if (!sb_set_blocksize(sb, ctx->blksize))
1688 goto err;
1689#endif
1690 } else {
1691 sb->s_blocksize = PAGE_SIZE;
1692 sb->s_blocksize_bits = PAGE_SHIFT;
1693 }
1694
1695 sb->s_subtype = ctx->subtype;
1696 ctx->subtype = NULL;
1697 if (IS_ENABLED(CONFIG_FUSE_DAX)) {
1698 err = fuse_dax_conn_alloc(fc, ctx->dax_mode, ctx->dax_dev);
1699 if (err)
1700 goto err;
1701 }
1702
1703 if (ctx->fudptr) {
1704 err = -ENOMEM;
1705 fud = fuse_dev_alloc_install(fc);
1706 if (!fud)
1707 goto err_free_dax;
1708 }
1709
1710 fc->dev = sb->s_dev;
1711 fm->sb = sb;
1712 err = fuse_bdi_init(fc, sb);
1713 if (err)
1714 goto err_dev_free;
1715
1716 /* Handle umasking inside the fuse code */
1717 if (sb->s_flags & SB_POSIXACL)
1718 fc->dont_mask = 1;
1719 sb->s_flags |= SB_POSIXACL;
1720
1721 fc->default_permissions = ctx->default_permissions;
1722 fc->allow_other = ctx->allow_other;
1723 fc->user_id = ctx->user_id;
1724 fc->group_id = ctx->group_id;
1725 fc->legacy_opts_show = ctx->legacy_opts_show;
1726 fc->max_read = max_t(unsigned int, 4096, ctx->max_read);
1727 fc->destroy = ctx->destroy;
1728 fc->no_control = ctx->no_control;
1729 fc->no_force_umount = ctx->no_force_umount;
1730
1731 err = -ENOMEM;
1732 root = fuse_get_root_inode(sb, ctx->rootmode);
1733 sb->s_d_op = &fuse_root_dentry_operations;
1734 root_dentry = d_make_root(root);
1735 if (!root_dentry)
1736 goto err_dev_free;
1737 /* Root dentry doesn't have .d_revalidate */
1738 sb->s_d_op = &fuse_dentry_operations;
1739
1740 mutex_lock(&fuse_mutex);
1741 err = -EINVAL;
1742 if (ctx->fudptr && *ctx->fudptr)
1743 goto err_unlock;
1744
1745 err = fuse_ctl_add_conn(fc);
1746 if (err)
1747 goto err_unlock;
1748
1749 list_add_tail(&fc->entry, &fuse_conn_list);
1750 sb->s_root = root_dentry;
1751 if (ctx->fudptr)
1752 *ctx->fudptr = fud;
1753 mutex_unlock(&fuse_mutex);
1754 return 0;
1755
1756 err_unlock:
1757 mutex_unlock(&fuse_mutex);
1758 dput(root_dentry);
1759 err_dev_free:
1760 if (fud)
1761 fuse_dev_free(fud);
1762 err_free_dax:
1763 if (IS_ENABLED(CONFIG_FUSE_DAX))
1764 fuse_dax_conn_free(fc);
1765 err:
1766 return err;
1767}
1768EXPORT_SYMBOL_GPL(fuse_fill_super_common);
1769
1770static int fuse_fill_super(struct super_block *sb, struct fs_context *fsc)
1771{
1772 struct fuse_fs_context *ctx = fsc->fs_private;
1773 int err;
1774
1775 if (!ctx->file || !ctx->rootmode_present ||
1776 !ctx->user_id_present || !ctx->group_id_present)
1777 return -EINVAL;
1778
1779 /*
1780 * Require mount to happen from the same user namespace which
1781 * opened /dev/fuse to prevent potential attacks.
1782 */
1783 if ((ctx->file->f_op != &fuse_dev_operations) ||
1784 (ctx->file->f_cred->user_ns != sb->s_user_ns))
1785 return -EINVAL;
1786 ctx->fudptr = &ctx->file->private_data;
1787
1788 err = fuse_fill_super_common(sb, ctx);
1789 if (err)
1790 return err;
1791 /* file->private_data shall be visible on all CPUs after this */
1792 smp_mb();
1793 fuse_send_init(get_fuse_mount_super(sb));
1794 return 0;
1795}
1796
1797/*
1798 * This is the path where user supplied an already initialized fuse dev. In
1799 * this case never create a new super if the old one is gone.
1800 */
1801static int fuse_set_no_super(struct super_block *sb, struct fs_context *fsc)
1802{
1803 return -ENOTCONN;
1804}
1805
1806static int fuse_test_super(struct super_block *sb, struct fs_context *fsc)
1807{
1808
1809 return fsc->sget_key == get_fuse_conn_super(sb);
1810}
1811
1812static int fuse_get_tree(struct fs_context *fsc)
1813{
1814 struct fuse_fs_context *ctx = fsc->fs_private;
1815 struct fuse_dev *fud;
1816 struct fuse_conn *fc;
1817 struct fuse_mount *fm;
1818 struct super_block *sb;
1819 int err;
1820
1821 fc = kmalloc(sizeof(*fc), GFP_KERNEL);
1822 if (!fc)
1823 return -ENOMEM;
1824
1825 fm = kzalloc(sizeof(*fm), GFP_KERNEL);
1826 if (!fm) {
1827 kfree(fc);
1828 return -ENOMEM;
1829 }
1830
1831 fuse_conn_init(fc, fm, fsc->user_ns, &fuse_dev_fiq_ops, NULL);
1832 fc->release = fuse_free_conn;
1833
1834 fsc->s_fs_info = fm;
1835
1836 if (ctx->fd_present)
1837 ctx->file = fget(ctx->fd);
1838
1839 if (IS_ENABLED(CONFIG_BLOCK) && ctx->is_bdev) {
1840 err = get_tree_bdev(fsc, fuse_fill_super);
1841 goto out;
1842 }
1843 /*
1844 * While block dev mount can be initialized with a dummy device fd
1845 * (found by device name), normal fuse mounts can't
1846 */
1847 err = -EINVAL;
1848 if (!ctx->file)
1849 goto out;
1850
1851 /*
1852 * Allow creating a fuse mount with an already initialized fuse
1853 * connection
1854 */
1855 fud = READ_ONCE(ctx->file->private_data);
1856 if (ctx->file->f_op == &fuse_dev_operations && fud) {
1857 fsc->sget_key = fud->fc;
1858 sb = sget_fc(fsc, fuse_test_super, fuse_set_no_super);
1859 err = PTR_ERR_OR_ZERO(sb);
1860 if (!IS_ERR(sb))
1861 fsc->root = dget(sb->s_root);
1862 } else {
1863 err = get_tree_nodev(fsc, fuse_fill_super);
1864 }
1865out:
1866 if (fsc->s_fs_info)
1867 fuse_mount_destroy(fm);
1868 if (ctx->file)
1869 fput(ctx->file);
1870 return err;
1871}
1872
1873static const struct fs_context_operations fuse_context_ops = {
1874 .free = fuse_free_fsc,
1875 .parse_param = fuse_parse_param,
1876 .reconfigure = fuse_reconfigure,
1877 .get_tree = fuse_get_tree,
1878};
1879
1880/*
1881 * Set up the filesystem mount context.
1882 */
1883static int fuse_init_fs_context(struct fs_context *fsc)
1884{
1885 struct fuse_fs_context *ctx;
1886
1887 ctx = kzalloc(sizeof(struct fuse_fs_context), GFP_KERNEL);
1888 if (!ctx)
1889 return -ENOMEM;
1890
1891 ctx->max_read = ~0;
1892 ctx->blksize = FUSE_DEFAULT_BLKSIZE;
1893 ctx->legacy_opts_show = true;
1894
1895#ifdef CONFIG_BLOCK
1896 if (fsc->fs_type == &fuseblk_fs_type) {
1897 ctx->is_bdev = true;
1898 ctx->destroy = true;
1899 }
1900#endif
1901
1902 fsc->fs_private = ctx;
1903 fsc->ops = &fuse_context_ops;
1904 return 0;
1905}
1906
1907bool fuse_mount_remove(struct fuse_mount *fm)
1908{
1909 struct fuse_conn *fc = fm->fc;
1910 bool last = false;
1911
1912 down_write(&fc->killsb);
1913 list_del_init(&fm->fc_entry);
1914 if (list_empty(&fc->mounts))
1915 last = true;
1916 up_write(&fc->killsb);
1917
1918 return last;
1919}
1920EXPORT_SYMBOL_GPL(fuse_mount_remove);
1921
1922void fuse_conn_destroy(struct fuse_mount *fm)
1923{
1924 struct fuse_conn *fc = fm->fc;
1925
1926 if (fc->destroy)
1927 fuse_send_destroy(fm);
1928
1929 fuse_abort_conn(fc);
1930 fuse_wait_aborted(fc);
1931
1932 if (!list_empty(&fc->entry)) {
1933 mutex_lock(&fuse_mutex);
1934 list_del(&fc->entry);
1935 fuse_ctl_remove_conn(fc);
1936 mutex_unlock(&fuse_mutex);
1937 }
1938}
1939EXPORT_SYMBOL_GPL(fuse_conn_destroy);
1940
1941static void fuse_sb_destroy(struct super_block *sb)
1942{
1943 struct fuse_mount *fm = get_fuse_mount_super(sb);
1944 bool last;
1945
1946 if (sb->s_root) {
1947 last = fuse_mount_remove(fm);
1948 if (last)
1949 fuse_conn_destroy(fm);
1950 }
1951}
1952
1953void fuse_mount_destroy(struct fuse_mount *fm)
1954{
1955 fuse_conn_put(fm->fc);
1956 kfree_rcu(fm, rcu);
1957}
1958EXPORT_SYMBOL(fuse_mount_destroy);
1959
1960static void fuse_kill_sb_anon(struct super_block *sb)
1961{
1962 fuse_sb_destroy(sb);
1963 kill_anon_super(sb);
1964 fuse_mount_destroy(get_fuse_mount_super(sb));
1965}
1966
1967static struct file_system_type fuse_fs_type = {
1968 .owner = THIS_MODULE,
1969 .name = "fuse",
1970 .fs_flags = FS_HAS_SUBTYPE | FS_USERNS_MOUNT,
1971 .init_fs_context = fuse_init_fs_context,
1972 .parameters = fuse_fs_parameters,
1973 .kill_sb = fuse_kill_sb_anon,
1974};
1975MODULE_ALIAS_FS("fuse");
1976
1977#ifdef CONFIG_BLOCK
1978static void fuse_kill_sb_blk(struct super_block *sb)
1979{
1980 fuse_sb_destroy(sb);
1981 kill_block_super(sb);
1982 fuse_mount_destroy(get_fuse_mount_super(sb));
1983}
1984
1985static struct file_system_type fuseblk_fs_type = {
1986 .owner = THIS_MODULE,
1987 .name = "fuseblk",
1988 .init_fs_context = fuse_init_fs_context,
1989 .parameters = fuse_fs_parameters,
1990 .kill_sb = fuse_kill_sb_blk,
1991 .fs_flags = FS_REQUIRES_DEV | FS_HAS_SUBTYPE,
1992};
1993MODULE_ALIAS_FS("fuseblk");
1994
1995static inline int register_fuseblk(void)
1996{
1997 return register_filesystem(&fuseblk_fs_type);
1998}
1999
2000static inline void unregister_fuseblk(void)
2001{
2002 unregister_filesystem(&fuseblk_fs_type);
2003}
2004#else
2005static inline int register_fuseblk(void)
2006{
2007 return 0;
2008}
2009
2010static inline void unregister_fuseblk(void)
2011{
2012}
2013#endif
2014
2015static void fuse_inode_init_once(void *foo)
2016{
2017 struct inode *inode = foo;
2018
2019 inode_init_once(inode);
2020}
2021
2022static int __init fuse_fs_init(void)
2023{
2024 int err;
2025
2026 fuse_inode_cachep = kmem_cache_create("fuse_inode",
2027 sizeof(struct fuse_inode), 0,
2028 SLAB_HWCACHE_ALIGN|SLAB_ACCOUNT|SLAB_RECLAIM_ACCOUNT,
2029 fuse_inode_init_once);
2030 err = -ENOMEM;
2031 if (!fuse_inode_cachep)
2032 goto out;
2033
2034 err = register_fuseblk();
2035 if (err)
2036 goto out2;
2037
2038 err = register_filesystem(&fuse_fs_type);
2039 if (err)
2040 goto out3;
2041
2042 return 0;
2043
2044 out3:
2045 unregister_fuseblk();
2046 out2:
2047 kmem_cache_destroy(fuse_inode_cachep);
2048 out:
2049 return err;
2050}
2051
2052static void fuse_fs_cleanup(void)
2053{
2054 unregister_filesystem(&fuse_fs_type);
2055 unregister_fuseblk();
2056
2057 /*
2058 * Make sure all delayed rcu free inodes are flushed before we
2059 * destroy cache.
2060 */
2061 rcu_barrier();
2062 kmem_cache_destroy(fuse_inode_cachep);
2063}
2064
2065static struct kobject *fuse_kobj;
2066
2067static int fuse_sysfs_init(void)
2068{
2069 int err;
2070
2071 fuse_kobj = kobject_create_and_add("fuse", fs_kobj);
2072 if (!fuse_kobj) {
2073 err = -ENOMEM;
2074 goto out_err;
2075 }
2076
2077 err = sysfs_create_mount_point(fuse_kobj, "connections");
2078 if (err)
2079 goto out_fuse_unregister;
2080
2081 return 0;
2082
2083 out_fuse_unregister:
2084 kobject_put(fuse_kobj);
2085 out_err:
2086 return err;
2087}
2088
2089static void fuse_sysfs_cleanup(void)
2090{
2091 sysfs_remove_mount_point(fuse_kobj, "connections");
2092 kobject_put(fuse_kobj);
2093}
2094
2095static int __init fuse_init(void)
2096{
2097 int res;
2098
2099 pr_info("init (API version %i.%i)\n",
2100 FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
2101
2102 INIT_LIST_HEAD(&fuse_conn_list);
2103 res = fuse_fs_init();
2104 if (res)
2105 goto err;
2106
2107 res = fuse_dev_init();
2108 if (res)
2109 goto err_fs_cleanup;
2110
2111 res = fuse_sysfs_init();
2112 if (res)
2113 goto err_dev_cleanup;
2114
2115 res = fuse_ctl_init();
2116 if (res)
2117 goto err_sysfs_cleanup;
2118
2119 sanitize_global_limit(&max_user_bgreq);
2120 sanitize_global_limit(&max_user_congthresh);
2121
2122 return 0;
2123
2124 err_sysfs_cleanup:
2125 fuse_sysfs_cleanup();
2126 err_dev_cleanup:
2127 fuse_dev_cleanup();
2128 err_fs_cleanup:
2129 fuse_fs_cleanup();
2130 err:
2131 return res;
2132}
2133
2134static void __exit fuse_exit(void)
2135{
2136 pr_debug("exit\n");
2137
2138 fuse_ctl_cleanup();
2139 fuse_sysfs_cleanup();
2140 fuse_fs_cleanup();
2141 fuse_dev_cleanup();
2142}
2143
2144module_init(fuse_init);
2145module_exit(fuse_exit);