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TOMOYO Linux Cross Reference
Linux/fs/fuse/inode.c

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  1 /*
  2   FUSE: Filesystem in Userspace
  3   Copyright (C) 2001-2008  Miklos Szeredi <miklos@szeredi.hu>
  4 
  5   This program can be distributed under the terms of the GNU GPL.
  6   See the file COPYING.
  7 */
  8 
  9 #include "fuse_i.h"
 10 
 11 #include <linux/pagemap.h>
 12 #include <linux/slab.h>
 13 #include <linux/file.h>
 14 #include <linux/seq_file.h>
 15 #include <linux/init.h>
 16 #include <linux/module.h>
 17 #include <linux/moduleparam.h>
 18 #include <linux/parser.h>
 19 #include <linux/statfs.h>
 20 #include <linux/random.h>
 21 #include <linux/sched.h>
 22 #include <linux/exportfs.h>
 23 
 24 MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>");
 25 MODULE_DESCRIPTION("Filesystem in Userspace");
 26 MODULE_LICENSE("GPL");
 27 
 28 static struct kmem_cache *fuse_inode_cachep;
 29 struct list_head fuse_conn_list;
 30 DEFINE_MUTEX(fuse_mutex);
 31 
 32 static int set_global_limit(const char *val, struct kernel_param *kp);
 33 
 34 unsigned max_user_bgreq;
 35 module_param_call(max_user_bgreq, set_global_limit, param_get_uint,
 36                   &max_user_bgreq, 0644);
 37 __MODULE_PARM_TYPE(max_user_bgreq, "uint");
 38 MODULE_PARM_DESC(max_user_bgreq,
 39  "Global limit for the maximum number of backgrounded requests an "
 40  "unprivileged user can set");
 41 
 42 unsigned max_user_congthresh;
 43 module_param_call(max_user_congthresh, set_global_limit, param_get_uint,
 44                   &max_user_congthresh, 0644);
 45 __MODULE_PARM_TYPE(max_user_congthresh, "uint");
 46 MODULE_PARM_DESC(max_user_congthresh,
 47  "Global limit for the maximum congestion threshold an "
 48  "unprivileged user can set");
 49 
 50 #define FUSE_SUPER_MAGIC 0x65735546
 51 
 52 #define FUSE_DEFAULT_BLKSIZE 512
 53 
 54 /** Maximum number of outstanding background requests */
 55 #define FUSE_DEFAULT_MAX_BACKGROUND 12
 56 
 57 /** Congestion starts at 75% of maximum */
 58 #define FUSE_DEFAULT_CONGESTION_THRESHOLD (FUSE_DEFAULT_MAX_BACKGROUND * 3 / 4)
 59 
 60 struct fuse_mount_data {
 61         int fd;
 62         unsigned rootmode;
 63         kuid_t user_id;
 64         kgid_t group_id;
 65         unsigned fd_present:1;
 66         unsigned rootmode_present:1;
 67         unsigned user_id_present:1;
 68         unsigned group_id_present:1;
 69         unsigned flags;
 70         unsigned max_read;
 71         unsigned blksize;
 72 };
 73 
 74 struct fuse_forget_link *fuse_alloc_forget(void)
 75 {
 76         return kzalloc(sizeof(struct fuse_forget_link), GFP_KERNEL);
 77 }
 78 
 79 static struct inode *fuse_alloc_inode(struct super_block *sb)
 80 {
 81         struct inode *inode;
 82         struct fuse_inode *fi;
 83 
 84         inode = kmem_cache_alloc(fuse_inode_cachep, GFP_KERNEL);
 85         if (!inode)
 86                 return NULL;
 87 
 88         fi = get_fuse_inode(inode);
 89         fi->i_time = 0;
 90         fi->nodeid = 0;
 91         fi->nlookup = 0;
 92         fi->attr_version = 0;
 93         fi->writectr = 0;
 94         fi->orig_ino = 0;
 95         fi->state = 0;
 96         INIT_LIST_HEAD(&fi->write_files);
 97         INIT_LIST_HEAD(&fi->queued_writes);
 98         INIT_LIST_HEAD(&fi->writepages);
 99         init_waitqueue_head(&fi->page_waitq);
100         fi->forget = fuse_alloc_forget();
101         if (!fi->forget) {
102                 kmem_cache_free(fuse_inode_cachep, inode);
103                 return NULL;
104         }
105 
106         return inode;
107 }
108 
109 static void fuse_i_callback(struct rcu_head *head)
110 {
111         struct inode *inode = container_of(head, struct inode, i_rcu);
112         kmem_cache_free(fuse_inode_cachep, inode);
113 }
114 
115 static void fuse_destroy_inode(struct inode *inode)
116 {
117         struct fuse_inode *fi = get_fuse_inode(inode);
118         BUG_ON(!list_empty(&fi->write_files));
119         BUG_ON(!list_empty(&fi->queued_writes));
120         kfree(fi->forget);
121         call_rcu(&inode->i_rcu, fuse_i_callback);
122 }
123 
124 static void fuse_evict_inode(struct inode *inode)
125 {
126         truncate_inode_pages_final(&inode->i_data);
127         clear_inode(inode);
128         if (inode->i_sb->s_flags & MS_ACTIVE) {
129                 struct fuse_conn *fc = get_fuse_conn(inode);
130                 struct fuse_inode *fi = get_fuse_inode(inode);
131                 fuse_queue_forget(fc, fi->forget, fi->nodeid, fi->nlookup);
132                 fi->forget = NULL;
133         }
134 }
135 
136 static int fuse_remount_fs(struct super_block *sb, int *flags, char *data)
137 {
138         sync_filesystem(sb);
139         if (*flags & MS_MANDLOCK)
140                 return -EINVAL;
141 
142         return 0;
143 }
144 
145 /*
146  * ino_t is 32-bits on 32-bit arch. We have to squash the 64-bit value down
147  * so that it will fit.
148  */
149 static ino_t fuse_squash_ino(u64 ino64)
150 {
151         ino_t ino = (ino_t) ino64;
152         if (sizeof(ino_t) < sizeof(u64))
153                 ino ^= ino64 >> (sizeof(u64) - sizeof(ino_t)) * 8;
154         return ino;
155 }
156 
157 void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
158                                    u64 attr_valid)
159 {
160         struct fuse_conn *fc = get_fuse_conn(inode);
161         struct fuse_inode *fi = get_fuse_inode(inode);
162 
163         fi->attr_version = ++fc->attr_version;
164         fi->i_time = attr_valid;
165 
166         inode->i_ino     = fuse_squash_ino(attr->ino);
167         inode->i_mode    = (inode->i_mode & S_IFMT) | (attr->mode & 07777);
168         set_nlink(inode, attr->nlink);
169         inode->i_uid     = make_kuid(&init_user_ns, attr->uid);
170         inode->i_gid     = make_kgid(&init_user_ns, attr->gid);
171         inode->i_blocks  = attr->blocks;
172         inode->i_atime.tv_sec   = attr->atime;
173         inode->i_atime.tv_nsec  = attr->atimensec;
174         /* mtime from server may be stale due to local buffered write */
175         if (!fc->writeback_cache || !S_ISREG(inode->i_mode)) {
176                 inode->i_mtime.tv_sec   = attr->mtime;
177                 inode->i_mtime.tv_nsec  = attr->mtimensec;
178                 inode->i_ctime.tv_sec   = attr->ctime;
179                 inode->i_ctime.tv_nsec  = attr->ctimensec;
180         }
181 
182         if (attr->blksize != 0)
183                 inode->i_blkbits = ilog2(attr->blksize);
184         else
185                 inode->i_blkbits = inode->i_sb->s_blocksize_bits;
186 
187         /*
188          * Don't set the sticky bit in i_mode, unless we want the VFS
189          * to check permissions.  This prevents failures due to the
190          * check in may_delete().
191          */
192         fi->orig_i_mode = inode->i_mode;
193         if (!(fc->flags & FUSE_DEFAULT_PERMISSIONS))
194                 inode->i_mode &= ~S_ISVTX;
195 
196         fi->orig_ino = attr->ino;
197 }
198 
199 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
200                             u64 attr_valid, u64 attr_version)
201 {
202         struct fuse_conn *fc = get_fuse_conn(inode);
203         struct fuse_inode *fi = get_fuse_inode(inode);
204         bool is_wb = fc->writeback_cache;
205         loff_t oldsize;
206         struct timespec old_mtime;
207 
208         spin_lock(&fc->lock);
209         if ((attr_version != 0 && fi->attr_version > attr_version) ||
210             test_bit(FUSE_I_SIZE_UNSTABLE, &fi->state)) {
211                 spin_unlock(&fc->lock);
212                 return;
213         }
214 
215         old_mtime = inode->i_mtime;
216         fuse_change_attributes_common(inode, attr, attr_valid);
217 
218         oldsize = inode->i_size;
219         /*
220          * In case of writeback_cache enabled, the cached writes beyond EOF
221          * extend local i_size without keeping userspace server in sync. So,
222          * attr->size coming from server can be stale. We cannot trust it.
223          */
224         if (!is_wb || !S_ISREG(inode->i_mode))
225                 i_size_write(inode, attr->size);
226         spin_unlock(&fc->lock);
227 
228         if (!is_wb && S_ISREG(inode->i_mode)) {
229                 bool inval = false;
230 
231                 if (oldsize != attr->size) {
232                         truncate_pagecache(inode, attr->size);
233                         inval = true;
234                 } else if (fc->auto_inval_data) {
235                         struct timespec new_mtime = {
236                                 .tv_sec = attr->mtime,
237                                 .tv_nsec = attr->mtimensec,
238                         };
239 
240                         /*
241                          * Auto inval mode also checks and invalidates if mtime
242                          * has changed.
243                          */
244                         if (!timespec_equal(&old_mtime, &new_mtime))
245                                 inval = true;
246                 }
247 
248                 if (inval)
249                         invalidate_inode_pages2(inode->i_mapping);
250         }
251 }
252 
253 static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
254 {
255         inode->i_mode = attr->mode & S_IFMT;
256         inode->i_size = attr->size;
257         inode->i_mtime.tv_sec  = attr->mtime;
258         inode->i_mtime.tv_nsec = attr->mtimensec;
259         inode->i_ctime.tv_sec  = attr->ctime;
260         inode->i_ctime.tv_nsec = attr->ctimensec;
261         if (S_ISREG(inode->i_mode)) {
262                 fuse_init_common(inode);
263                 fuse_init_file_inode(inode);
264         } else if (S_ISDIR(inode->i_mode))
265                 fuse_init_dir(inode);
266         else if (S_ISLNK(inode->i_mode))
267                 fuse_init_symlink(inode);
268         else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
269                  S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
270                 fuse_init_common(inode);
271                 init_special_inode(inode, inode->i_mode,
272                                    new_decode_dev(attr->rdev));
273         } else
274                 BUG();
275 }
276 
277 int fuse_inode_eq(struct inode *inode, void *_nodeidp)
278 {
279         u64 nodeid = *(u64 *) _nodeidp;
280         if (get_node_id(inode) == nodeid)
281                 return 1;
282         else
283                 return 0;
284 }
285 
286 static int fuse_inode_set(struct inode *inode, void *_nodeidp)
287 {
288         u64 nodeid = *(u64 *) _nodeidp;
289         get_fuse_inode(inode)->nodeid = nodeid;
290         return 0;
291 }
292 
293 struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
294                         int generation, struct fuse_attr *attr,
295                         u64 attr_valid, u64 attr_version)
296 {
297         struct inode *inode;
298         struct fuse_inode *fi;
299         struct fuse_conn *fc = get_fuse_conn_super(sb);
300 
301  retry:
302         inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid);
303         if (!inode)
304                 return NULL;
305 
306         if ((inode->i_state & I_NEW)) {
307                 inode->i_flags |= S_NOATIME;
308                 if (!fc->writeback_cache || !S_ISREG(attr->mode))
309                         inode->i_flags |= S_NOCMTIME;
310                 inode->i_generation = generation;
311                 fuse_init_inode(inode, attr);
312                 unlock_new_inode(inode);
313         } else if ((inode->i_mode ^ attr->mode) & S_IFMT) {
314                 /* Inode has changed type, any I/O on the old should fail */
315                 make_bad_inode(inode);
316                 iput(inode);
317                 goto retry;
318         }
319 
320         fi = get_fuse_inode(inode);
321         spin_lock(&fc->lock);
322         fi->nlookup++;
323         spin_unlock(&fc->lock);
324         fuse_change_attributes(inode, attr, attr_valid, attr_version);
325 
326         return inode;
327 }
328 
329 int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid,
330                              loff_t offset, loff_t len)
331 {
332         struct inode *inode;
333         pgoff_t pg_start;
334         pgoff_t pg_end;
335 
336         inode = ilookup5(sb, nodeid, fuse_inode_eq, &nodeid);
337         if (!inode)
338                 return -ENOENT;
339 
340         fuse_invalidate_attr(inode);
341         if (offset >= 0) {
342                 pg_start = offset >> PAGE_SHIFT;
343                 if (len <= 0)
344                         pg_end = -1;
345                 else
346                         pg_end = (offset + len - 1) >> PAGE_SHIFT;
347                 invalidate_inode_pages2_range(inode->i_mapping,
348                                               pg_start, pg_end);
349         }
350         iput(inode);
351         return 0;
352 }
353 
354 static void fuse_umount_begin(struct super_block *sb)
355 {
356         fuse_abort_conn(get_fuse_conn_super(sb));
357 }
358 
359 static void fuse_send_destroy(struct fuse_conn *fc)
360 {
361         struct fuse_req *req = fc->destroy_req;
362         if (req && fc->conn_init) {
363                 fc->destroy_req = NULL;
364                 req->in.h.opcode = FUSE_DESTROY;
365                 __set_bit(FR_FORCE, &req->flags);
366                 __clear_bit(FR_BACKGROUND, &req->flags);
367                 fuse_request_send(fc, req);
368                 fuse_put_request(fc, req);
369         }
370 }
371 
372 static void fuse_bdi_destroy(struct fuse_conn *fc)
373 {
374         if (fc->bdi_initialized)
375                 bdi_destroy(&fc->bdi);
376 }
377 
378 static void fuse_put_super(struct super_block *sb)
379 {
380         struct fuse_conn *fc = get_fuse_conn_super(sb);
381 
382         fuse_send_destroy(fc);
383 
384         fuse_abort_conn(fc);
385         mutex_lock(&fuse_mutex);
386         list_del(&fc->entry);
387         fuse_ctl_remove_conn(fc);
388         mutex_unlock(&fuse_mutex);
389         fuse_bdi_destroy(fc);
390 
391         fuse_conn_put(fc);
392 }
393 
394 static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
395 {
396         stbuf->f_type    = FUSE_SUPER_MAGIC;
397         stbuf->f_bsize   = attr->bsize;
398         stbuf->f_frsize  = attr->frsize;
399         stbuf->f_blocks  = attr->blocks;
400         stbuf->f_bfree   = attr->bfree;
401         stbuf->f_bavail  = attr->bavail;
402         stbuf->f_files   = attr->files;
403         stbuf->f_ffree   = attr->ffree;
404         stbuf->f_namelen = attr->namelen;
405         /* fsid is left zero */
406 }
407 
408 static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf)
409 {
410         struct super_block *sb = dentry->d_sb;
411         struct fuse_conn *fc = get_fuse_conn_super(sb);
412         FUSE_ARGS(args);
413         struct fuse_statfs_out outarg;
414         int err;
415 
416         if (!fuse_allow_current_process(fc)) {
417                 buf->f_type = FUSE_SUPER_MAGIC;
418                 return 0;
419         }
420 
421         memset(&outarg, 0, sizeof(outarg));
422         args.in.numargs = 0;
423         args.in.h.opcode = FUSE_STATFS;
424         args.in.h.nodeid = get_node_id(d_inode(dentry));
425         args.out.numargs = 1;
426         args.out.args[0].size = sizeof(outarg);
427         args.out.args[0].value = &outarg;
428         err = fuse_simple_request(fc, &args);
429         if (!err)
430                 convert_fuse_statfs(buf, &outarg.st);
431         return err;
432 }
433 
434 enum {
435         OPT_FD,
436         OPT_ROOTMODE,
437         OPT_USER_ID,
438         OPT_GROUP_ID,
439         OPT_DEFAULT_PERMISSIONS,
440         OPT_ALLOW_OTHER,
441         OPT_MAX_READ,
442         OPT_BLKSIZE,
443         OPT_ERR
444 };
445 
446 static const match_table_t tokens = {
447         {OPT_FD,                        "fd=%u"},
448         {OPT_ROOTMODE,                  "rootmode=%o"},
449         {OPT_USER_ID,                   "user_id=%u"},
450         {OPT_GROUP_ID,                  "group_id=%u"},
451         {OPT_DEFAULT_PERMISSIONS,       "default_permissions"},
452         {OPT_ALLOW_OTHER,               "allow_other"},
453         {OPT_MAX_READ,                  "max_read=%u"},
454         {OPT_BLKSIZE,                   "blksize=%u"},
455         {OPT_ERR,                       NULL}
456 };
457 
458 static int fuse_match_uint(substring_t *s, unsigned int *res)
459 {
460         int err = -ENOMEM;
461         char *buf = match_strdup(s);
462         if (buf) {
463                 err = kstrtouint(buf, 10, res);
464                 kfree(buf);
465         }
466         return err;
467 }
468 
469 static int parse_fuse_opt(char *opt, struct fuse_mount_data *d, int is_bdev)
470 {
471         char *p;
472         memset(d, 0, sizeof(struct fuse_mount_data));
473         d->max_read = ~0;
474         d->blksize = FUSE_DEFAULT_BLKSIZE;
475 
476         while ((p = strsep(&opt, ",")) != NULL) {
477                 int token;
478                 int value;
479                 unsigned uv;
480                 substring_t args[MAX_OPT_ARGS];
481                 if (!*p)
482                         continue;
483 
484                 token = match_token(p, tokens, args);
485                 switch (token) {
486                 case OPT_FD:
487                         if (match_int(&args[0], &value))
488                                 return 0;
489                         d->fd = value;
490                         d->fd_present = 1;
491                         break;
492 
493                 case OPT_ROOTMODE:
494                         if (match_octal(&args[0], &value))
495                                 return 0;
496                         if (!fuse_valid_type(value))
497                                 return 0;
498                         d->rootmode = value;
499                         d->rootmode_present = 1;
500                         break;
501 
502                 case OPT_USER_ID:
503                         if (fuse_match_uint(&args[0], &uv))
504                                 return 0;
505                         d->user_id = make_kuid(current_user_ns(), uv);
506                         if (!uid_valid(d->user_id))
507                                 return 0;
508                         d->user_id_present = 1;
509                         break;
510 
511                 case OPT_GROUP_ID:
512                         if (fuse_match_uint(&args[0], &uv))
513                                 return 0;
514                         d->group_id = make_kgid(current_user_ns(), uv);
515                         if (!gid_valid(d->group_id))
516                                 return 0;
517                         d->group_id_present = 1;
518                         break;
519 
520                 case OPT_DEFAULT_PERMISSIONS:
521                         d->flags |= FUSE_DEFAULT_PERMISSIONS;
522                         break;
523 
524                 case OPT_ALLOW_OTHER:
525                         d->flags |= FUSE_ALLOW_OTHER;
526                         break;
527 
528                 case OPT_MAX_READ:
529                         if (match_int(&args[0], &value))
530                                 return 0;
531                         d->max_read = value;
532                         break;
533 
534                 case OPT_BLKSIZE:
535                         if (!is_bdev || match_int(&args[0], &value))
536                                 return 0;
537                         d->blksize = value;
538                         break;
539 
540                 default:
541                         return 0;
542                 }
543         }
544 
545         if (!d->fd_present || !d->rootmode_present ||
546             !d->user_id_present || !d->group_id_present)
547                 return 0;
548 
549         return 1;
550 }
551 
552 static int fuse_show_options(struct seq_file *m, struct dentry *root)
553 {
554         struct super_block *sb = root->d_sb;
555         struct fuse_conn *fc = get_fuse_conn_super(sb);
556 
557         seq_printf(m, ",user_id=%u", from_kuid_munged(&init_user_ns, fc->user_id));
558         seq_printf(m, ",group_id=%u", from_kgid_munged(&init_user_ns, fc->group_id));
559         if (fc->flags & FUSE_DEFAULT_PERMISSIONS)
560                 seq_puts(m, ",default_permissions");
561         if (fc->flags & FUSE_ALLOW_OTHER)
562                 seq_puts(m, ",allow_other");
563         if (fc->max_read != ~0)
564                 seq_printf(m, ",max_read=%u", fc->max_read);
565         if (sb->s_bdev && sb->s_blocksize != FUSE_DEFAULT_BLKSIZE)
566                 seq_printf(m, ",blksize=%lu", sb->s_blocksize);
567         return 0;
568 }
569 
570 static void fuse_iqueue_init(struct fuse_iqueue *fiq)
571 {
572         memset(fiq, 0, sizeof(struct fuse_iqueue));
573         init_waitqueue_head(&fiq->waitq);
574         INIT_LIST_HEAD(&fiq->pending);
575         INIT_LIST_HEAD(&fiq->interrupts);
576         fiq->forget_list_tail = &fiq->forget_list_head;
577         fiq->connected = 1;
578 }
579 
580 static void fuse_pqueue_init(struct fuse_pqueue *fpq)
581 {
582         memset(fpq, 0, sizeof(struct fuse_pqueue));
583         spin_lock_init(&fpq->lock);
584         INIT_LIST_HEAD(&fpq->processing);
585         INIT_LIST_HEAD(&fpq->io);
586         fpq->connected = 1;
587 }
588 
589 void fuse_conn_init(struct fuse_conn *fc)
590 {
591         memset(fc, 0, sizeof(*fc));
592         spin_lock_init(&fc->lock);
593         init_rwsem(&fc->killsb);
594         atomic_set(&fc->count, 1);
595         atomic_set(&fc->dev_count, 1);
596         init_waitqueue_head(&fc->blocked_waitq);
597         init_waitqueue_head(&fc->reserved_req_waitq);
598         fuse_iqueue_init(&fc->iq);
599         INIT_LIST_HEAD(&fc->bg_queue);
600         INIT_LIST_HEAD(&fc->entry);
601         INIT_LIST_HEAD(&fc->devices);
602         atomic_set(&fc->num_waiting, 0);
603         fc->max_background = FUSE_DEFAULT_MAX_BACKGROUND;
604         fc->congestion_threshold = FUSE_DEFAULT_CONGESTION_THRESHOLD;
605         fc->khctr = 0;
606         fc->polled_files = RB_ROOT;
607         fc->blocked = 0;
608         fc->initialized = 0;
609         fc->connected = 1;
610         fc->attr_version = 1;
611         get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key));
612 }
613 EXPORT_SYMBOL_GPL(fuse_conn_init);
614 
615 void fuse_conn_put(struct fuse_conn *fc)
616 {
617         if (atomic_dec_and_test(&fc->count)) {
618                 if (fc->destroy_req)
619                         fuse_request_free(fc->destroy_req);
620                 fc->release(fc);
621         }
622 }
623 EXPORT_SYMBOL_GPL(fuse_conn_put);
624 
625 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc)
626 {
627         atomic_inc(&fc->count);
628         return fc;
629 }
630 EXPORT_SYMBOL_GPL(fuse_conn_get);
631 
632 static struct inode *fuse_get_root_inode(struct super_block *sb, unsigned mode)
633 {
634         struct fuse_attr attr;
635         memset(&attr, 0, sizeof(attr));
636 
637         attr.mode = mode;
638         attr.ino = FUSE_ROOT_ID;
639         attr.nlink = 1;
640         return fuse_iget(sb, 1, 0, &attr, 0, 0);
641 }
642 
643 struct fuse_inode_handle {
644         u64 nodeid;
645         u32 generation;
646 };
647 
648 static struct dentry *fuse_get_dentry(struct super_block *sb,
649                                       struct fuse_inode_handle *handle)
650 {
651         struct fuse_conn *fc = get_fuse_conn_super(sb);
652         struct inode *inode;
653         struct dentry *entry;
654         int err = -ESTALE;
655 
656         if (handle->nodeid == 0)
657                 goto out_err;
658 
659         inode = ilookup5(sb, handle->nodeid, fuse_inode_eq, &handle->nodeid);
660         if (!inode) {
661                 struct fuse_entry_out outarg;
662                 struct qstr name;
663 
664                 if (!fc->export_support)
665                         goto out_err;
666 
667                 name.len = 1;
668                 name.name = ".";
669                 err = fuse_lookup_name(sb, handle->nodeid, &name, &outarg,
670                                        &inode);
671                 if (err && err != -ENOENT)
672                         goto out_err;
673                 if (err || !inode) {
674                         err = -ESTALE;
675                         goto out_err;
676                 }
677                 err = -EIO;
678                 if (get_node_id(inode) != handle->nodeid)
679                         goto out_iput;
680         }
681         err = -ESTALE;
682         if (inode->i_generation != handle->generation)
683                 goto out_iput;
684 
685         entry = d_obtain_alias(inode);
686         if (!IS_ERR(entry) && get_node_id(inode) != FUSE_ROOT_ID)
687                 fuse_invalidate_entry_cache(entry);
688 
689         return entry;
690 
691  out_iput:
692         iput(inode);
693  out_err:
694         return ERR_PTR(err);
695 }
696 
697 static int fuse_encode_fh(struct inode *inode, u32 *fh, int *max_len,
698                            struct inode *parent)
699 {
700         int len = parent ? 6 : 3;
701         u64 nodeid;
702         u32 generation;
703 
704         if (*max_len < len) {
705                 *max_len = len;
706                 return  FILEID_INVALID;
707         }
708 
709         nodeid = get_fuse_inode(inode)->nodeid;
710         generation = inode->i_generation;
711 
712         fh[0] = (u32)(nodeid >> 32);
713         fh[1] = (u32)(nodeid & 0xffffffff);
714         fh[2] = generation;
715 
716         if (parent) {
717                 nodeid = get_fuse_inode(parent)->nodeid;
718                 generation = parent->i_generation;
719 
720                 fh[3] = (u32)(nodeid >> 32);
721                 fh[4] = (u32)(nodeid & 0xffffffff);
722                 fh[5] = generation;
723         }
724 
725         *max_len = len;
726         return parent ? 0x82 : 0x81;
727 }
728 
729 static struct dentry *fuse_fh_to_dentry(struct super_block *sb,
730                 struct fid *fid, int fh_len, int fh_type)
731 {
732         struct fuse_inode_handle handle;
733 
734         if ((fh_type != 0x81 && fh_type != 0x82) || fh_len < 3)
735                 return NULL;
736 
737         handle.nodeid = (u64) fid->raw[0] << 32;
738         handle.nodeid |= (u64) fid->raw[1];
739         handle.generation = fid->raw[2];
740         return fuse_get_dentry(sb, &handle);
741 }
742 
743 static struct dentry *fuse_fh_to_parent(struct super_block *sb,
744                 struct fid *fid, int fh_len, int fh_type)
745 {
746         struct fuse_inode_handle parent;
747 
748         if (fh_type != 0x82 || fh_len < 6)
749                 return NULL;
750 
751         parent.nodeid = (u64) fid->raw[3] << 32;
752         parent.nodeid |= (u64) fid->raw[4];
753         parent.generation = fid->raw[5];
754         return fuse_get_dentry(sb, &parent);
755 }
756 
757 static struct dentry *fuse_get_parent(struct dentry *child)
758 {
759         struct inode *child_inode = d_inode(child);
760         struct fuse_conn *fc = get_fuse_conn(child_inode);
761         struct inode *inode;
762         struct dentry *parent;
763         struct fuse_entry_out outarg;
764         struct qstr name;
765         int err;
766 
767         if (!fc->export_support)
768                 return ERR_PTR(-ESTALE);
769 
770         name.len = 2;
771         name.name = "..";
772         err = fuse_lookup_name(child_inode->i_sb, get_node_id(child_inode),
773                                &name, &outarg, &inode);
774         if (err) {
775                 if (err == -ENOENT)
776                         return ERR_PTR(-ESTALE);
777                 return ERR_PTR(err);
778         }
779 
780         parent = d_obtain_alias(inode);
781         if (!IS_ERR(parent) && get_node_id(inode) != FUSE_ROOT_ID)
782                 fuse_invalidate_entry_cache(parent);
783 
784         return parent;
785 }
786 
787 static const struct export_operations fuse_export_operations = {
788         .fh_to_dentry   = fuse_fh_to_dentry,
789         .fh_to_parent   = fuse_fh_to_parent,
790         .encode_fh      = fuse_encode_fh,
791         .get_parent     = fuse_get_parent,
792 };
793 
794 static const struct super_operations fuse_super_operations = {
795         .alloc_inode    = fuse_alloc_inode,
796         .destroy_inode  = fuse_destroy_inode,
797         .evict_inode    = fuse_evict_inode,
798         .write_inode    = fuse_write_inode,
799         .drop_inode     = generic_delete_inode,
800         .remount_fs     = fuse_remount_fs,
801         .put_super      = fuse_put_super,
802         .umount_begin   = fuse_umount_begin,
803         .statfs         = fuse_statfs,
804         .show_options   = fuse_show_options,
805 };
806 
807 static void sanitize_global_limit(unsigned *limit)
808 {
809         if (*limit == 0)
810                 *limit = ((totalram_pages << PAGE_SHIFT) >> 13) /
811                          sizeof(struct fuse_req);
812 
813         if (*limit >= 1 << 16)
814                 *limit = (1 << 16) - 1;
815 }
816 
817 static int set_global_limit(const char *val, struct kernel_param *kp)
818 {
819         int rv;
820 
821         rv = param_set_uint(val, kp);
822         if (rv)
823                 return rv;
824 
825         sanitize_global_limit((unsigned *)kp->arg);
826 
827         return 0;
828 }
829 
830 static void process_init_limits(struct fuse_conn *fc, struct fuse_init_out *arg)
831 {
832         int cap_sys_admin = capable(CAP_SYS_ADMIN);
833 
834         if (arg->minor < 13)
835                 return;
836 
837         sanitize_global_limit(&max_user_bgreq);
838         sanitize_global_limit(&max_user_congthresh);
839 
840         if (arg->max_background) {
841                 fc->max_background = arg->max_background;
842 
843                 if (!cap_sys_admin && fc->max_background > max_user_bgreq)
844                         fc->max_background = max_user_bgreq;
845         }
846         if (arg->congestion_threshold) {
847                 fc->congestion_threshold = arg->congestion_threshold;
848 
849                 if (!cap_sys_admin &&
850                     fc->congestion_threshold > max_user_congthresh)
851                         fc->congestion_threshold = max_user_congthresh;
852         }
853 }
854 
855 static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
856 {
857         struct fuse_init_out *arg = &req->misc.init_out;
858 
859         if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION)
860                 fc->conn_error = 1;
861         else {
862                 unsigned long ra_pages;
863 
864                 process_init_limits(fc, arg);
865 
866                 if (arg->minor >= 6) {
867                         ra_pages = arg->max_readahead / PAGE_SIZE;
868                         if (arg->flags & FUSE_ASYNC_READ)
869                                 fc->async_read = 1;
870                         if (!(arg->flags & FUSE_POSIX_LOCKS))
871                                 fc->no_lock = 1;
872                         if (arg->minor >= 17) {
873                                 if (!(arg->flags & FUSE_FLOCK_LOCKS))
874                                         fc->no_flock = 1;
875                         } else {
876                                 if (!(arg->flags & FUSE_POSIX_LOCKS))
877                                         fc->no_flock = 1;
878                         }
879                         if (arg->flags & FUSE_ATOMIC_O_TRUNC)
880                                 fc->atomic_o_trunc = 1;
881                         if (arg->minor >= 9) {
882                                 /* LOOKUP has dependency on proto version */
883                                 if (arg->flags & FUSE_EXPORT_SUPPORT)
884                                         fc->export_support = 1;
885                         }
886                         if (arg->flags & FUSE_BIG_WRITES)
887                                 fc->big_writes = 1;
888                         if (arg->flags & FUSE_DONT_MASK)
889                                 fc->dont_mask = 1;
890                         if (arg->flags & FUSE_AUTO_INVAL_DATA)
891                                 fc->auto_inval_data = 1;
892                         if (arg->flags & FUSE_DO_READDIRPLUS) {
893                                 fc->do_readdirplus = 1;
894                                 if (arg->flags & FUSE_READDIRPLUS_AUTO)
895                                         fc->readdirplus_auto = 1;
896                         }
897                         if (arg->flags & FUSE_ASYNC_DIO)
898                                 fc->async_dio = 1;
899                         if (arg->flags & FUSE_WRITEBACK_CACHE)
900                                 fc->writeback_cache = 1;
901                         if (arg->time_gran && arg->time_gran <= 1000000000)
902                                 fc->sb->s_time_gran = arg->time_gran;
903                 } else {
904                         ra_pages = fc->max_read / PAGE_SIZE;
905                         fc->no_lock = 1;
906                         fc->no_flock = 1;
907                 }
908 
909                 fc->bdi.ra_pages = min(fc->bdi.ra_pages, ra_pages);
910                 fc->minor = arg->minor;
911                 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
912                 fc->max_write = max_t(unsigned, 4096, fc->max_write);
913                 fc->conn_init = 1;
914         }
915         fuse_set_initialized(fc);
916         wake_up_all(&fc->blocked_waitq);
917 }
918 
919 static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req)
920 {
921         struct fuse_init_in *arg = &req->misc.init_in;
922 
923         arg->major = FUSE_KERNEL_VERSION;
924         arg->minor = FUSE_KERNEL_MINOR_VERSION;
925         arg->max_readahead = fc->bdi.ra_pages * PAGE_SIZE;
926         arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_ATOMIC_O_TRUNC |
927                 FUSE_EXPORT_SUPPORT | FUSE_BIG_WRITES | FUSE_DONT_MASK |
928                 FUSE_SPLICE_WRITE | FUSE_SPLICE_MOVE | FUSE_SPLICE_READ |
929                 FUSE_FLOCK_LOCKS | FUSE_HAS_IOCTL_DIR | FUSE_AUTO_INVAL_DATA |
930                 FUSE_DO_READDIRPLUS | FUSE_READDIRPLUS_AUTO | FUSE_ASYNC_DIO |
931                 FUSE_WRITEBACK_CACHE | FUSE_NO_OPEN_SUPPORT;
932         req->in.h.opcode = FUSE_INIT;
933         req->in.numargs = 1;
934         req->in.args[0].size = sizeof(*arg);
935         req->in.args[0].value = arg;
936         req->out.numargs = 1;
937         /* Variable length argument used for backward compatibility
938            with interface version < 7.5.  Rest of init_out is zeroed
939            by do_get_request(), so a short reply is not a problem */
940         req->out.argvar = 1;
941         req->out.args[0].size = sizeof(struct fuse_init_out);
942         req->out.args[0].value = &req->misc.init_out;
943         req->end = process_init_reply;
944         fuse_request_send_background(fc, req);
945 }
946 
947 static void fuse_free_conn(struct fuse_conn *fc)
948 {
949         WARN_ON(!list_empty(&fc->devices));
950         kfree_rcu(fc, rcu);
951 }
952 
953 static int fuse_bdi_init(struct fuse_conn *fc, struct super_block *sb)
954 {
955         int err;
956 
957         fc->bdi.name = "fuse";
958         fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_SIZE;
959         /* fuse does it's own writeback accounting */
960         fc->bdi.capabilities = BDI_CAP_NO_ACCT_WB | BDI_CAP_STRICTLIMIT;
961 
962         err = bdi_init(&fc->bdi);
963         if (err)
964                 return err;
965 
966         fc->bdi_initialized = 1;
967 
968         if (sb->s_bdev) {
969                 err =  bdi_register(&fc->bdi, NULL, "%u:%u-fuseblk",
970                                     MAJOR(fc->dev), MINOR(fc->dev));
971         } else {
972                 err = bdi_register_dev(&fc->bdi, fc->dev);
973         }
974 
975         if (err)
976                 return err;
977 
978         /*
979          * For a single fuse filesystem use max 1% of dirty +
980          * writeback threshold.
981          *
982          * This gives about 1M of write buffer for memory maps on a
983          * machine with 1G and 10% dirty_ratio, which should be more
984          * than enough.
985          *
986          * Privileged users can raise it by writing to
987          *
988          *    /sys/class/bdi/<bdi>/max_ratio
989          */
990         bdi_set_max_ratio(&fc->bdi, 1);
991 
992         return 0;
993 }
994 
995 struct fuse_dev *fuse_dev_alloc(struct fuse_conn *fc)
996 {
997         struct fuse_dev *fud;
998 
999         fud = kzalloc(sizeof(struct fuse_dev), GFP_KERNEL);
1000         if (fud) {
1001                 fud->fc = fuse_conn_get(fc);
1002                 fuse_pqueue_init(&fud->pq);
1003 
1004                 spin_lock(&fc->lock);
1005                 list_add_tail(&fud->entry, &fc->devices);
1006                 spin_unlock(&fc->lock);
1007         }
1008 
1009         return fud;
1010 }
1011 EXPORT_SYMBOL_GPL(fuse_dev_alloc);
1012 
1013 void fuse_dev_free(struct fuse_dev *fud)
1014 {
1015         struct fuse_conn *fc = fud->fc;
1016 
1017         if (fc) {
1018                 spin_lock(&fc->lock);
1019                 list_del(&fud->entry);
1020                 spin_unlock(&fc->lock);
1021 
1022                 fuse_conn_put(fc);
1023         }
1024         kfree(fud);
1025 }
1026 EXPORT_SYMBOL_GPL(fuse_dev_free);
1027 
1028 static int fuse_fill_super(struct super_block *sb, void *data, int silent)
1029 {
1030         struct fuse_dev *fud;
1031         struct fuse_conn *fc;
1032         struct inode *root;
1033         struct fuse_mount_data d;
1034         struct file *file;
1035         struct dentry *root_dentry;
1036         struct fuse_req *init_req;
1037         int err;
1038         int is_bdev = sb->s_bdev != NULL;
1039 
1040         err = -EINVAL;
1041         if (sb->s_flags & MS_MANDLOCK)
1042                 goto err;
1043 
1044         sb->s_flags &= ~(MS_NOSEC | MS_I_VERSION);
1045 
1046         if (!parse_fuse_opt(data, &d, is_bdev))
1047                 goto err;
1048 
1049         if (is_bdev) {
1050 #ifdef CONFIG_BLOCK
1051                 err = -EINVAL;
1052                 if (!sb_set_blocksize(sb, d.blksize))
1053                         goto err;
1054 #endif
1055         } else {
1056                 sb->s_blocksize = PAGE_SIZE;
1057                 sb->s_blocksize_bits = PAGE_SHIFT;
1058         }
1059         sb->s_magic = FUSE_SUPER_MAGIC;
1060         sb->s_op = &fuse_super_operations;
1061         sb->s_maxbytes = MAX_LFS_FILESIZE;
1062         sb->s_time_gran = 1;
1063         sb->s_export_op = &fuse_export_operations;
1064 
1065         file = fget(d.fd);
1066         err = -EINVAL;
1067         if (!file)
1068                 goto err;
1069 
1070         if ((file->f_op != &fuse_dev_operations) ||
1071             (file->f_cred->user_ns != &init_user_ns))
1072                 goto err_fput;
1073 
1074         fc = kmalloc(sizeof(*fc), GFP_KERNEL);
1075         err = -ENOMEM;
1076         if (!fc)
1077                 goto err_fput;
1078 
1079         fuse_conn_init(fc);
1080         fc->release = fuse_free_conn;
1081 
1082         fud = fuse_dev_alloc(fc);
1083         if (!fud)
1084                 goto err_put_conn;
1085 
1086         fc->dev = sb->s_dev;
1087         fc->sb = sb;
1088         err = fuse_bdi_init(fc, sb);
1089         if (err)
1090                 goto err_dev_free;
1091 
1092         sb->s_bdi = &fc->bdi;
1093 
1094         /* Handle umasking inside the fuse code */
1095         if (sb->s_flags & MS_POSIXACL)
1096                 fc->dont_mask = 1;
1097         sb->s_flags |= MS_POSIXACL;
1098 
1099         fc->flags = d.flags;
1100         fc->user_id = d.user_id;
1101         fc->group_id = d.group_id;
1102         fc->max_read = max_t(unsigned, 4096, d.max_read);
1103 
1104         /* Used by get_root_inode() */
1105         sb->s_fs_info = fc;
1106 
1107         err = -ENOMEM;
1108         root = fuse_get_root_inode(sb, d.rootmode);
1109         root_dentry = d_make_root(root);
1110         if (!root_dentry)
1111                 goto err_dev_free;
1112         /* only now - we want root dentry with NULL ->d_op */
1113         sb->s_d_op = &fuse_dentry_operations;
1114 
1115         init_req = fuse_request_alloc(0);
1116         if (!init_req)
1117                 goto err_put_root;
1118         __set_bit(FR_BACKGROUND, &init_req->flags);
1119 
1120         if (is_bdev) {
1121                 fc->destroy_req = fuse_request_alloc(0);
1122                 if (!fc->destroy_req)
1123                         goto err_free_init_req;
1124         }
1125 
1126         mutex_lock(&fuse_mutex);
1127         err = -EINVAL;
1128         if (file->private_data)
1129                 goto err_unlock;
1130 
1131         err = fuse_ctl_add_conn(fc);
1132         if (err)
1133                 goto err_unlock;
1134 
1135         list_add_tail(&fc->entry, &fuse_conn_list);
1136         sb->s_root = root_dentry;
1137         file->private_data = fud;
1138         mutex_unlock(&fuse_mutex);
1139         /*
1140          * atomic_dec_and_test() in fput() provides the necessary
1141          * memory barrier for file->private_data to be visible on all
1142          * CPUs after this
1143          */
1144         fput(file);
1145 
1146         fuse_send_init(fc, init_req);
1147 
1148         return 0;
1149 
1150  err_unlock:
1151         mutex_unlock(&fuse_mutex);
1152  err_free_init_req:
1153         fuse_request_free(init_req);
1154  err_put_root:
1155         dput(root_dentry);
1156  err_dev_free:
1157         fuse_dev_free(fud);
1158  err_put_conn:
1159         fuse_bdi_destroy(fc);
1160         fuse_conn_put(fc);
1161  err_fput:
1162         fput(file);
1163  err:
1164         return err;
1165 }
1166 
1167 static struct dentry *fuse_mount(struct file_system_type *fs_type,
1168                        int flags, const char *dev_name,
1169                        void *raw_data)
1170 {
1171         return mount_nodev(fs_type, flags, raw_data, fuse_fill_super);
1172 }
1173 
1174 static void fuse_kill_sb_anon(struct super_block *sb)
1175 {
1176         struct fuse_conn *fc = get_fuse_conn_super(sb);
1177 
1178         if (fc) {
1179                 down_write(&fc->killsb);
1180                 fc->sb = NULL;
1181                 up_write(&fc->killsb);
1182         }
1183 
1184         kill_anon_super(sb);
1185 }
1186 
1187 static struct file_system_type fuse_fs_type = {
1188         .owner          = THIS_MODULE,
1189         .name           = "fuse",
1190         .fs_flags       = FS_HAS_SUBTYPE,
1191         .mount          = fuse_mount,
1192         .kill_sb        = fuse_kill_sb_anon,
1193 };
1194 MODULE_ALIAS_FS("fuse");
1195 
1196 #ifdef CONFIG_BLOCK
1197 static struct dentry *fuse_mount_blk(struct file_system_type *fs_type,
1198                            int flags, const char *dev_name,
1199                            void *raw_data)
1200 {
1201         return mount_bdev(fs_type, flags, dev_name, raw_data, fuse_fill_super);
1202 }
1203 
1204 static void fuse_kill_sb_blk(struct super_block *sb)
1205 {
1206         struct fuse_conn *fc = get_fuse_conn_super(sb);
1207 
1208         if (fc) {
1209                 down_write(&fc->killsb);
1210                 fc->sb = NULL;
1211                 up_write(&fc->killsb);
1212         }
1213 
1214         kill_block_super(sb);
1215 }
1216 
1217 static struct file_system_type fuseblk_fs_type = {
1218         .owner          = THIS_MODULE,
1219         .name           = "fuseblk",
1220         .mount          = fuse_mount_blk,
1221         .kill_sb        = fuse_kill_sb_blk,
1222         .fs_flags       = FS_REQUIRES_DEV | FS_HAS_SUBTYPE,
1223 };
1224 MODULE_ALIAS_FS("fuseblk");
1225 
1226 static inline int register_fuseblk(void)
1227 {
1228         return register_filesystem(&fuseblk_fs_type);
1229 }
1230 
1231 static inline void unregister_fuseblk(void)
1232 {
1233         unregister_filesystem(&fuseblk_fs_type);
1234 }
1235 #else
1236 static inline int register_fuseblk(void)
1237 {
1238         return 0;
1239 }
1240 
1241 static inline void unregister_fuseblk(void)
1242 {
1243 }
1244 #endif
1245 
1246 static void fuse_inode_init_once(void *foo)
1247 {
1248         struct inode *inode = foo;
1249 
1250         inode_init_once(inode);
1251 }
1252 
1253 static int __init fuse_fs_init(void)
1254 {
1255         int err;
1256 
1257         fuse_inode_cachep = kmem_cache_create("fuse_inode",
1258                                               sizeof(struct fuse_inode), 0,
1259                                               SLAB_HWCACHE_ALIGN|SLAB_ACCOUNT,
1260                                               fuse_inode_init_once);
1261         err = -ENOMEM;
1262         if (!fuse_inode_cachep)
1263                 goto out;
1264 
1265         err = register_fuseblk();
1266         if (err)
1267                 goto out2;
1268 
1269         err = register_filesystem(&fuse_fs_type);
1270         if (err)
1271                 goto out3;
1272 
1273         return 0;
1274 
1275  out3:
1276         unregister_fuseblk();
1277  out2:
1278         kmem_cache_destroy(fuse_inode_cachep);
1279  out:
1280         return err;
1281 }
1282 
1283 static void fuse_fs_cleanup(void)
1284 {
1285         unregister_filesystem(&fuse_fs_type);
1286         unregister_fuseblk();
1287 
1288         /*
1289          * Make sure all delayed rcu free inodes are flushed before we
1290          * destroy cache.
1291          */
1292         rcu_barrier();
1293         kmem_cache_destroy(fuse_inode_cachep);
1294 }
1295 
1296 static struct kobject *fuse_kobj;
1297 
1298 static int fuse_sysfs_init(void)
1299 {
1300         int err;
1301 
1302         fuse_kobj = kobject_create_and_add("fuse", fs_kobj);
1303         if (!fuse_kobj) {
1304                 err = -ENOMEM;
1305                 goto out_err;
1306         }
1307 
1308         err = sysfs_create_mount_point(fuse_kobj, "connections");
1309         if (err)
1310                 goto out_fuse_unregister;
1311 
1312         return 0;
1313 
1314  out_fuse_unregister:
1315         kobject_put(fuse_kobj);
1316  out_err:
1317         return err;
1318 }
1319 
1320 static void fuse_sysfs_cleanup(void)
1321 {
1322         sysfs_remove_mount_point(fuse_kobj, "connections");
1323         kobject_put(fuse_kobj);
1324 }
1325 
1326 static int __init fuse_init(void)
1327 {
1328         int res;
1329 
1330         printk(KERN_INFO "fuse init (API version %i.%i)\n",
1331                FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
1332 
1333         INIT_LIST_HEAD(&fuse_conn_list);
1334         res = fuse_fs_init();
1335         if (res)
1336                 goto err;
1337 
1338         res = fuse_dev_init();
1339         if (res)
1340                 goto err_fs_cleanup;
1341 
1342         res = fuse_sysfs_init();
1343         if (res)
1344                 goto err_dev_cleanup;
1345 
1346         res = fuse_ctl_init();
1347         if (res)
1348                 goto err_sysfs_cleanup;
1349 
1350         sanitize_global_limit(&max_user_bgreq);
1351         sanitize_global_limit(&max_user_congthresh);
1352 
1353         return 0;
1354 
1355  err_sysfs_cleanup:
1356         fuse_sysfs_cleanup();
1357  err_dev_cleanup:
1358         fuse_dev_cleanup();
1359  err_fs_cleanup:
1360         fuse_fs_cleanup();
1361  err:
1362         return res;
1363 }
1364 
1365 static void __exit fuse_exit(void)
1366 {
1367         printk(KERN_DEBUG "fuse exit\n");
1368 
1369         fuse_ctl_cleanup();
1370         fuse_sysfs_cleanup();
1371         fuse_fs_cleanup();
1372         fuse_dev_cleanup();
1373 }
1374 
1375 module_init(fuse_init);
1376 module_exit(fuse_exit);
1377 

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