[IA64] Minimize per_cpu reservations.
[linux-2.6] / fs / fuse / inode.c
1 /*
2   FUSE: Filesystem in Userspace
3   Copyright (C) 2001-2006  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/parser.h>
18 #include <linux/statfs.h>
19 #include <linux/random.h>
20 #include <linux/sched.h>
21
22 MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>");
23 MODULE_DESCRIPTION("Filesystem in Userspace");
24 MODULE_LICENSE("GPL");
25
26 static struct kmem_cache *fuse_inode_cachep;
27 struct list_head fuse_conn_list;
28 DEFINE_MUTEX(fuse_mutex);
29
30 #define FUSE_SUPER_MAGIC 0x65735546
31
32 #define FUSE_DEFAULT_BLKSIZE 512
33
34 struct fuse_mount_data {
35         int fd;
36         unsigned rootmode;
37         unsigned user_id;
38         unsigned group_id;
39         unsigned fd_present : 1;
40         unsigned rootmode_present : 1;
41         unsigned user_id_present : 1;
42         unsigned group_id_present : 1;
43         unsigned flags;
44         unsigned max_read;
45         unsigned blksize;
46 };
47
48 static struct inode *fuse_alloc_inode(struct super_block *sb)
49 {
50         struct inode *inode;
51         struct fuse_inode *fi;
52
53         inode = kmem_cache_alloc(fuse_inode_cachep, GFP_KERNEL);
54         if (!inode)
55                 return NULL;
56
57         fi = get_fuse_inode(inode);
58         fi->i_time = 0;
59         fi->nodeid = 0;
60         fi->nlookup = 0;
61         fi->attr_version = 0;
62         INIT_LIST_HEAD(&fi->write_files);
63         fi->forget_req = fuse_request_alloc();
64         if (!fi->forget_req) {
65                 kmem_cache_free(fuse_inode_cachep, inode);
66                 return NULL;
67         }
68
69         return inode;
70 }
71
72 static void fuse_destroy_inode(struct inode *inode)
73 {
74         struct fuse_inode *fi = get_fuse_inode(inode);
75         BUG_ON(!list_empty(&fi->write_files));
76         if (fi->forget_req)
77                 fuse_request_free(fi->forget_req);
78         kmem_cache_free(fuse_inode_cachep, inode);
79 }
80
81 void fuse_send_forget(struct fuse_conn *fc, struct fuse_req *req,
82                       unsigned long nodeid, u64 nlookup)
83 {
84         struct fuse_forget_in *inarg = &req->misc.forget_in;
85         inarg->nlookup = nlookup;
86         req->in.h.opcode = FUSE_FORGET;
87         req->in.h.nodeid = nodeid;
88         req->in.numargs = 1;
89         req->in.args[0].size = sizeof(struct fuse_forget_in);
90         req->in.args[0].value = inarg;
91         request_send_noreply(fc, req);
92 }
93
94 static void fuse_clear_inode(struct inode *inode)
95 {
96         if (inode->i_sb->s_flags & MS_ACTIVE) {
97                 struct fuse_conn *fc = get_fuse_conn(inode);
98                 struct fuse_inode *fi = get_fuse_inode(inode);
99                 fuse_send_forget(fc, fi->forget_req, fi->nodeid, fi->nlookup);
100                 fi->forget_req = NULL;
101         }
102 }
103
104 static int fuse_remount_fs(struct super_block *sb, int *flags, char *data)
105 {
106         if (*flags & MS_MANDLOCK)
107                 return -EINVAL;
108
109         return 0;
110 }
111
112 static void fuse_truncate(struct address_space *mapping, loff_t offset)
113 {
114         /* See vmtruncate() */
115         unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1);
116         truncate_inode_pages(mapping, offset);
117         unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1);
118 }
119
120
121 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
122                             u64 attr_valid, u64 attr_version)
123 {
124         struct fuse_conn *fc = get_fuse_conn(inode);
125         struct fuse_inode *fi = get_fuse_inode(inode);
126         loff_t oldsize;
127
128         spin_lock(&fc->lock);
129         if (attr_version != 0 && fi->attr_version > attr_version) {
130                 spin_unlock(&fc->lock);
131                 return;
132         }
133         fi->attr_version = ++fc->attr_version;
134         fi->i_time = attr_valid;
135
136         inode->i_ino     = attr->ino;
137         inode->i_mode    = (inode->i_mode & S_IFMT) | (attr->mode & 07777);
138         inode->i_nlink   = attr->nlink;
139         inode->i_uid     = attr->uid;
140         inode->i_gid     = attr->gid;
141         inode->i_blocks  = attr->blocks;
142         inode->i_atime.tv_sec   = attr->atime;
143         inode->i_atime.tv_nsec  = attr->atimensec;
144         inode->i_mtime.tv_sec   = attr->mtime;
145         inode->i_mtime.tv_nsec  = attr->mtimensec;
146         inode->i_ctime.tv_sec   = attr->ctime;
147         inode->i_ctime.tv_nsec  = attr->ctimensec;
148
149         if (attr->blksize != 0)
150                 inode->i_blkbits = ilog2(attr->blksize);
151         else
152                 inode->i_blkbits = inode->i_sb->s_blocksize_bits;
153
154         /*
155          * Don't set the sticky bit in i_mode, unless we want the VFS
156          * to check permissions.  This prevents failures due to the
157          * check in may_delete().
158          */
159         fi->orig_i_mode = inode->i_mode;
160         if (!(fc->flags & FUSE_DEFAULT_PERMISSIONS))
161                 inode->i_mode &= ~S_ISVTX;
162
163         oldsize = inode->i_size;
164         i_size_write(inode, attr->size);
165         spin_unlock(&fc->lock);
166
167         if (S_ISREG(inode->i_mode) && oldsize != attr->size) {
168                 if (attr->size < oldsize)
169                         fuse_truncate(inode->i_mapping, attr->size);
170                 invalidate_inode_pages2(inode->i_mapping);
171         }
172 }
173
174 static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
175 {
176         inode->i_mode = attr->mode & S_IFMT;
177         inode->i_size = attr->size;
178         if (S_ISREG(inode->i_mode)) {
179                 fuse_init_common(inode);
180                 fuse_init_file_inode(inode);
181         } else if (S_ISDIR(inode->i_mode))
182                 fuse_init_dir(inode);
183         else if (S_ISLNK(inode->i_mode))
184                 fuse_init_symlink(inode);
185         else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
186                  S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
187                 fuse_init_common(inode);
188                 init_special_inode(inode, inode->i_mode,
189                                    new_decode_dev(attr->rdev));
190         } else
191                 BUG();
192 }
193
194 static int fuse_inode_eq(struct inode *inode, void *_nodeidp)
195 {
196         unsigned long nodeid = *(unsigned long *) _nodeidp;
197         if (get_node_id(inode) == nodeid)
198                 return 1;
199         else
200                 return 0;
201 }
202
203 static int fuse_inode_set(struct inode *inode, void *_nodeidp)
204 {
205         unsigned long nodeid = *(unsigned long *) _nodeidp;
206         get_fuse_inode(inode)->nodeid = nodeid;
207         return 0;
208 }
209
210 struct inode *fuse_iget(struct super_block *sb, unsigned long nodeid,
211                         int generation, struct fuse_attr *attr,
212                         u64 attr_valid, u64 attr_version)
213 {
214         struct inode *inode;
215         struct fuse_inode *fi;
216         struct fuse_conn *fc = get_fuse_conn_super(sb);
217
218  retry:
219         inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid);
220         if (!inode)
221                 return NULL;
222
223         if ((inode->i_state & I_NEW)) {
224                 inode->i_flags |= S_NOATIME|S_NOCMTIME;
225                 inode->i_generation = generation;
226                 inode->i_data.backing_dev_info = &fc->bdi;
227                 fuse_init_inode(inode, attr);
228                 unlock_new_inode(inode);
229         } else if ((inode->i_mode ^ attr->mode) & S_IFMT) {
230                 /* Inode has changed type, any I/O on the old should fail */
231                 make_bad_inode(inode);
232                 iput(inode);
233                 goto retry;
234         }
235
236         fi = get_fuse_inode(inode);
237         spin_lock(&fc->lock);
238         fi->nlookup ++;
239         spin_unlock(&fc->lock);
240         fuse_change_attributes(inode, attr, attr_valid, attr_version);
241
242         return inode;
243 }
244
245 static void fuse_umount_begin(struct vfsmount *vfsmnt, int flags)
246 {
247         if (flags & MNT_FORCE)
248                 fuse_abort_conn(get_fuse_conn_super(vfsmnt->mnt_sb));
249 }
250
251 static void fuse_send_destroy(struct fuse_conn *fc)
252 {
253         struct fuse_req *req = fc->destroy_req;
254         if (req && fc->conn_init) {
255                 fc->destroy_req = NULL;
256                 req->in.h.opcode = FUSE_DESTROY;
257                 req->force = 1;
258                 request_send(fc, req);
259                 fuse_put_request(fc, req);
260         }
261 }
262
263 static void fuse_put_super(struct super_block *sb)
264 {
265         struct fuse_conn *fc = get_fuse_conn_super(sb);
266
267         fuse_send_destroy(fc);
268         spin_lock(&fc->lock);
269         fc->connected = 0;
270         fc->blocked = 0;
271         spin_unlock(&fc->lock);
272         /* Flush all readers on this fs */
273         kill_fasync(&fc->fasync, SIGIO, POLL_IN);
274         wake_up_all(&fc->waitq);
275         wake_up_all(&fc->blocked_waitq);
276         wake_up_all(&fc->reserved_req_waitq);
277         mutex_lock(&fuse_mutex);
278         list_del(&fc->entry);
279         fuse_ctl_remove_conn(fc);
280         mutex_unlock(&fuse_mutex);
281         fuse_conn_put(fc);
282 }
283
284 static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
285 {
286         stbuf->f_type    = FUSE_SUPER_MAGIC;
287         stbuf->f_bsize   = attr->bsize;
288         stbuf->f_frsize  = attr->frsize;
289         stbuf->f_blocks  = attr->blocks;
290         stbuf->f_bfree   = attr->bfree;
291         stbuf->f_bavail  = attr->bavail;
292         stbuf->f_files   = attr->files;
293         stbuf->f_ffree   = attr->ffree;
294         stbuf->f_namelen = attr->namelen;
295         /* fsid is left zero */
296 }
297
298 static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf)
299 {
300         struct super_block *sb = dentry->d_sb;
301         struct fuse_conn *fc = get_fuse_conn_super(sb);
302         struct fuse_req *req;
303         struct fuse_statfs_out outarg;
304         int err;
305
306         if (!fuse_allow_task(fc, current)) {
307                 buf->f_type = FUSE_SUPER_MAGIC;
308                 return 0;
309         }
310
311         req = fuse_get_req(fc);
312         if (IS_ERR(req))
313                 return PTR_ERR(req);
314
315         memset(&outarg, 0, sizeof(outarg));
316         req->in.numargs = 0;
317         req->in.h.opcode = FUSE_STATFS;
318         req->in.h.nodeid = get_node_id(dentry->d_inode);
319         req->out.numargs = 1;
320         req->out.args[0].size =
321                 fc->minor < 4 ? FUSE_COMPAT_STATFS_SIZE : sizeof(outarg);
322         req->out.args[0].value = &outarg;
323         request_send(fc, req);
324         err = req->out.h.error;
325         if (!err)
326                 convert_fuse_statfs(buf, &outarg.st);
327         fuse_put_request(fc, req);
328         return err;
329 }
330
331 enum {
332         OPT_FD,
333         OPT_ROOTMODE,
334         OPT_USER_ID,
335         OPT_GROUP_ID,
336         OPT_DEFAULT_PERMISSIONS,
337         OPT_ALLOW_OTHER,
338         OPT_MAX_READ,
339         OPT_BLKSIZE,
340         OPT_ERR
341 };
342
343 static match_table_t tokens = {
344         {OPT_FD,                        "fd=%u"},
345         {OPT_ROOTMODE,                  "rootmode=%o"},
346         {OPT_USER_ID,                   "user_id=%u"},
347         {OPT_GROUP_ID,                  "group_id=%u"},
348         {OPT_DEFAULT_PERMISSIONS,       "default_permissions"},
349         {OPT_ALLOW_OTHER,               "allow_other"},
350         {OPT_MAX_READ,                  "max_read=%u"},
351         {OPT_BLKSIZE,                   "blksize=%u"},
352         {OPT_ERR,                       NULL}
353 };
354
355 static int parse_fuse_opt(char *opt, struct fuse_mount_data *d, int is_bdev)
356 {
357         char *p;
358         memset(d, 0, sizeof(struct fuse_mount_data));
359         d->max_read = ~0;
360         d->blksize = FUSE_DEFAULT_BLKSIZE;
361
362         while ((p = strsep(&opt, ",")) != NULL) {
363                 int token;
364                 int value;
365                 substring_t args[MAX_OPT_ARGS];
366                 if (!*p)
367                         continue;
368
369                 token = match_token(p, tokens, args);
370                 switch (token) {
371                 case OPT_FD:
372                         if (match_int(&args[0], &value))
373                                 return 0;
374                         d->fd = value;
375                         d->fd_present = 1;
376                         break;
377
378                 case OPT_ROOTMODE:
379                         if (match_octal(&args[0], &value))
380                                 return 0;
381                         if (!fuse_valid_type(value))
382                                 return 0;
383                         d->rootmode = value;
384                         d->rootmode_present = 1;
385                         break;
386
387                 case OPT_USER_ID:
388                         if (match_int(&args[0], &value))
389                                 return 0;
390                         d->user_id = value;
391                         d->user_id_present = 1;
392                         break;
393
394                 case OPT_GROUP_ID:
395                         if (match_int(&args[0], &value))
396                                 return 0;
397                         d->group_id = value;
398                         d->group_id_present = 1;
399                         break;
400
401                 case OPT_DEFAULT_PERMISSIONS:
402                         d->flags |= FUSE_DEFAULT_PERMISSIONS;
403                         break;
404
405                 case OPT_ALLOW_OTHER:
406                         d->flags |= FUSE_ALLOW_OTHER;
407                         break;
408
409                 case OPT_MAX_READ:
410                         if (match_int(&args[0], &value))
411                                 return 0;
412                         d->max_read = value;
413                         break;
414
415                 case OPT_BLKSIZE:
416                         if (!is_bdev || match_int(&args[0], &value))
417                                 return 0;
418                         d->blksize = value;
419                         break;
420
421                 default:
422                         return 0;
423                 }
424         }
425
426         if (!d->fd_present || !d->rootmode_present ||
427             !d->user_id_present || !d->group_id_present)
428                 return 0;
429
430         return 1;
431 }
432
433 static int fuse_show_options(struct seq_file *m, struct vfsmount *mnt)
434 {
435         struct fuse_conn *fc = get_fuse_conn_super(mnt->mnt_sb);
436
437         seq_printf(m, ",user_id=%u", fc->user_id);
438         seq_printf(m, ",group_id=%u", fc->group_id);
439         if (fc->flags & FUSE_DEFAULT_PERMISSIONS)
440                 seq_puts(m, ",default_permissions");
441         if (fc->flags & FUSE_ALLOW_OTHER)
442                 seq_puts(m, ",allow_other");
443         if (fc->max_read != ~0)
444                 seq_printf(m, ",max_read=%u", fc->max_read);
445         if (mnt->mnt_sb->s_bdev &&
446             mnt->mnt_sb->s_blocksize != FUSE_DEFAULT_BLKSIZE)
447                 seq_printf(m, ",blksize=%lu", mnt->mnt_sb->s_blocksize);
448         return 0;
449 }
450
451 static struct fuse_conn *new_conn(void)
452 {
453         struct fuse_conn *fc;
454         int err;
455
456         fc = kzalloc(sizeof(*fc), GFP_KERNEL);
457         if (fc) {
458                 spin_lock_init(&fc->lock);
459                 mutex_init(&fc->inst_mutex);
460                 atomic_set(&fc->count, 1);
461                 init_waitqueue_head(&fc->waitq);
462                 init_waitqueue_head(&fc->blocked_waitq);
463                 init_waitqueue_head(&fc->reserved_req_waitq);
464                 INIT_LIST_HEAD(&fc->pending);
465                 INIT_LIST_HEAD(&fc->processing);
466                 INIT_LIST_HEAD(&fc->io);
467                 INIT_LIST_HEAD(&fc->interrupts);
468                 INIT_LIST_HEAD(&fc->bg_queue);
469                 atomic_set(&fc->num_waiting, 0);
470                 fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
471                 fc->bdi.unplug_io_fn = default_unplug_io_fn;
472                 err = bdi_init(&fc->bdi);
473                 if (err) {
474                         kfree(fc);
475                         fc = NULL;
476                         goto out;
477                 }
478                 fc->reqctr = 0;
479                 fc->blocked = 1;
480                 fc->attr_version = 1;
481                 get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key));
482         }
483 out:
484         return fc;
485 }
486
487 void fuse_conn_put(struct fuse_conn *fc)
488 {
489         if (atomic_dec_and_test(&fc->count)) {
490                 if (fc->destroy_req)
491                         fuse_request_free(fc->destroy_req);
492                 mutex_destroy(&fc->inst_mutex);
493                 bdi_destroy(&fc->bdi);
494                 kfree(fc);
495         }
496 }
497
498 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc)
499 {
500         atomic_inc(&fc->count);
501         return fc;
502 }
503
504 static struct inode *get_root_inode(struct super_block *sb, unsigned mode)
505 {
506         struct fuse_attr attr;
507         memset(&attr, 0, sizeof(attr));
508
509         attr.mode = mode;
510         attr.ino = FUSE_ROOT_ID;
511         attr.nlink = 1;
512         return fuse_iget(sb, 1, 0, &attr, 0, 0);
513 }
514
515 static const struct super_operations fuse_super_operations = {
516         .alloc_inode    = fuse_alloc_inode,
517         .destroy_inode  = fuse_destroy_inode,
518         .clear_inode    = fuse_clear_inode,
519         .drop_inode     = generic_delete_inode,
520         .remount_fs     = fuse_remount_fs,
521         .put_super      = fuse_put_super,
522         .umount_begin   = fuse_umount_begin,
523         .statfs         = fuse_statfs,
524         .show_options   = fuse_show_options,
525 };
526
527 static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
528 {
529         struct fuse_init_out *arg = &req->misc.init_out;
530
531         if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION)
532                 fc->conn_error = 1;
533         else {
534                 unsigned long ra_pages;
535
536                 if (arg->minor >= 6) {
537                         ra_pages = arg->max_readahead / PAGE_CACHE_SIZE;
538                         if (arg->flags & FUSE_ASYNC_READ)
539                                 fc->async_read = 1;
540                         if (!(arg->flags & FUSE_POSIX_LOCKS))
541                                 fc->no_lock = 1;
542                         if (arg->flags & FUSE_ATOMIC_O_TRUNC)
543                                 fc->atomic_o_trunc = 1;
544                 } else {
545                         ra_pages = fc->max_read / PAGE_CACHE_SIZE;
546                         fc->no_lock = 1;
547                 }
548
549                 fc->bdi.ra_pages = min(fc->bdi.ra_pages, ra_pages);
550                 fc->minor = arg->minor;
551                 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
552                 fc->conn_init = 1;
553         }
554         fuse_put_request(fc, req);
555         fc->blocked = 0;
556         wake_up_all(&fc->blocked_waitq);
557 }
558
559 static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req)
560 {
561         struct fuse_init_in *arg = &req->misc.init_in;
562
563         arg->major = FUSE_KERNEL_VERSION;
564         arg->minor = FUSE_KERNEL_MINOR_VERSION;
565         arg->max_readahead = fc->bdi.ra_pages * PAGE_CACHE_SIZE;
566         arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_ATOMIC_O_TRUNC;
567         req->in.h.opcode = FUSE_INIT;
568         req->in.numargs = 1;
569         req->in.args[0].size = sizeof(*arg);
570         req->in.args[0].value = arg;
571         req->out.numargs = 1;
572         /* Variable length arguement used for backward compatibility
573            with interface version < 7.5.  Rest of init_out is zeroed
574            by do_get_request(), so a short reply is not a problem */
575         req->out.argvar = 1;
576         req->out.args[0].size = sizeof(struct fuse_init_out);
577         req->out.args[0].value = &req->misc.init_out;
578         req->end = process_init_reply;
579         request_send_background(fc, req);
580 }
581
582 static u64 conn_id(void)
583 {
584         static u64 ctr = 1;
585         return ctr++;
586 }
587
588 static int fuse_fill_super(struct super_block *sb, void *data, int silent)
589 {
590         struct fuse_conn *fc;
591         struct inode *root;
592         struct fuse_mount_data d;
593         struct file *file;
594         struct dentry *root_dentry;
595         struct fuse_req *init_req;
596         int err;
597         int is_bdev = sb->s_bdev != NULL;
598
599         if (sb->s_flags & MS_MANDLOCK)
600                 return -EINVAL;
601
602         if (!parse_fuse_opt((char *) data, &d, is_bdev))
603                 return -EINVAL;
604
605         if (is_bdev) {
606 #ifdef CONFIG_BLOCK
607                 if (!sb_set_blocksize(sb, d.blksize))
608                         return -EINVAL;
609 #endif
610         } else {
611                 sb->s_blocksize = PAGE_CACHE_SIZE;
612                 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
613         }
614         sb->s_magic = FUSE_SUPER_MAGIC;
615         sb->s_op = &fuse_super_operations;
616         sb->s_maxbytes = MAX_LFS_FILESIZE;
617
618         file = fget(d.fd);
619         if (!file)
620                 return -EINVAL;
621
622         if (file->f_op != &fuse_dev_operations)
623                 return -EINVAL;
624
625         fc = new_conn();
626         if (!fc)
627                 return -ENOMEM;
628
629         fc->flags = d.flags;
630         fc->user_id = d.user_id;
631         fc->group_id = d.group_id;
632         fc->max_read = d.max_read;
633
634         /* Used by get_root_inode() */
635         sb->s_fs_info = fc;
636
637         err = -ENOMEM;
638         root = get_root_inode(sb, d.rootmode);
639         if (!root)
640                 goto err;
641
642         root_dentry = d_alloc_root(root);
643         if (!root_dentry) {
644                 iput(root);
645                 goto err;
646         }
647
648         init_req = fuse_request_alloc();
649         if (!init_req)
650                 goto err_put_root;
651
652         if (is_bdev) {
653                 fc->destroy_req = fuse_request_alloc();
654                 if (!fc->destroy_req)
655                         goto err_put_root;
656         }
657
658         mutex_lock(&fuse_mutex);
659         err = -EINVAL;
660         if (file->private_data)
661                 goto err_unlock;
662
663         fc->id = conn_id();
664         err = fuse_ctl_add_conn(fc);
665         if (err)
666                 goto err_unlock;
667
668         list_add_tail(&fc->entry, &fuse_conn_list);
669         sb->s_root = root_dentry;
670         fc->connected = 1;
671         file->private_data = fuse_conn_get(fc);
672         mutex_unlock(&fuse_mutex);
673         /*
674          * atomic_dec_and_test() in fput() provides the necessary
675          * memory barrier for file->private_data to be visible on all
676          * CPUs after this
677          */
678         fput(file);
679
680         fuse_send_init(fc, init_req);
681
682         return 0;
683
684  err_unlock:
685         mutex_unlock(&fuse_mutex);
686         fuse_request_free(init_req);
687  err_put_root:
688         dput(root_dentry);
689  err:
690         fput(file);
691         fuse_conn_put(fc);
692         return err;
693 }
694
695 static int fuse_get_sb(struct file_system_type *fs_type,
696                        int flags, const char *dev_name,
697                        void *raw_data, struct vfsmount *mnt)
698 {
699         return get_sb_nodev(fs_type, flags, raw_data, fuse_fill_super, mnt);
700 }
701
702 static struct file_system_type fuse_fs_type = {
703         .owner          = THIS_MODULE,
704         .name           = "fuse",
705         .fs_flags       = FS_HAS_SUBTYPE,
706         .get_sb         = fuse_get_sb,
707         .kill_sb        = kill_anon_super,
708 };
709
710 #ifdef CONFIG_BLOCK
711 static int fuse_get_sb_blk(struct file_system_type *fs_type,
712                            int flags, const char *dev_name,
713                            void *raw_data, struct vfsmount *mnt)
714 {
715         return get_sb_bdev(fs_type, flags, dev_name, raw_data, fuse_fill_super,
716                            mnt);
717 }
718
719 static struct file_system_type fuseblk_fs_type = {
720         .owner          = THIS_MODULE,
721         .name           = "fuseblk",
722         .get_sb         = fuse_get_sb_blk,
723         .kill_sb        = kill_block_super,
724         .fs_flags       = FS_REQUIRES_DEV | FS_HAS_SUBTYPE,
725 };
726
727 static inline int register_fuseblk(void)
728 {
729         return register_filesystem(&fuseblk_fs_type);
730 }
731
732 static inline void unregister_fuseblk(void)
733 {
734         unregister_filesystem(&fuseblk_fs_type);
735 }
736 #else
737 static inline int register_fuseblk(void)
738 {
739         return 0;
740 }
741
742 static inline void unregister_fuseblk(void)
743 {
744 }
745 #endif
746
747 static void fuse_inode_init_once(struct kmem_cache *cachep, void *foo)
748 {
749         struct inode * inode = foo;
750
751         inode_init_once(inode);
752 }
753
754 static int __init fuse_fs_init(void)
755 {
756         int err;
757
758         err = register_filesystem(&fuse_fs_type);
759         if (err)
760                 goto out;
761
762         err = register_fuseblk();
763         if (err)
764                 goto out_unreg;
765
766         fuse_inode_cachep = kmem_cache_create("fuse_inode",
767                                               sizeof(struct fuse_inode),
768                                               0, SLAB_HWCACHE_ALIGN,
769                                               fuse_inode_init_once);
770         err = -ENOMEM;
771         if (!fuse_inode_cachep)
772                 goto out_unreg2;
773
774         return 0;
775
776  out_unreg2:
777         unregister_fuseblk();
778  out_unreg:
779         unregister_filesystem(&fuse_fs_type);
780  out:
781         return err;
782 }
783
784 static void fuse_fs_cleanup(void)
785 {
786         unregister_filesystem(&fuse_fs_type);
787         unregister_fuseblk();
788         kmem_cache_destroy(fuse_inode_cachep);
789 }
790
791 static struct kobject *fuse_kobj;
792 static struct kobject *connections_kobj;
793
794 static int fuse_sysfs_init(void)
795 {
796         int err;
797
798         fuse_kobj = kobject_create_and_add("fuse", fs_kobj);
799         if (!fuse_kobj) {
800                 err = -ENOMEM;
801                 goto out_err;
802         }
803
804         connections_kobj = kobject_create_and_add("connections", fuse_kobj);
805         if (!connections_kobj) {
806                 err = -ENOMEM;
807                 goto out_fuse_unregister;
808         }
809
810         return 0;
811
812  out_fuse_unregister:
813         kobject_put(fuse_kobj);
814  out_err:
815         return err;
816 }
817
818 static void fuse_sysfs_cleanup(void)
819 {
820         kobject_put(connections_kobj);
821         kobject_put(fuse_kobj);
822 }
823
824 static int __init fuse_init(void)
825 {
826         int res;
827
828         printk("fuse init (API version %i.%i)\n",
829                FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
830
831         INIT_LIST_HEAD(&fuse_conn_list);
832         res = fuse_fs_init();
833         if (res)
834                 goto err;
835
836         res = fuse_dev_init();
837         if (res)
838                 goto err_fs_cleanup;
839
840         res = fuse_sysfs_init();
841         if (res)
842                 goto err_dev_cleanup;
843
844         res = fuse_ctl_init();
845         if (res)
846                 goto err_sysfs_cleanup;
847
848         return 0;
849
850  err_sysfs_cleanup:
851         fuse_sysfs_cleanup();
852  err_dev_cleanup:
853         fuse_dev_cleanup();
854  err_fs_cleanup:
855         fuse_fs_cleanup();
856  err:
857         return res;
858 }
859
860 static void __exit fuse_exit(void)
861 {
862         printk(KERN_DEBUG "fuse exit\n");
863
864         fuse_ctl_cleanup();
865         fuse_sysfs_cleanup();
866         fuse_fs_cleanup();
867         fuse_dev_cleanup();
868 }
869
870 module_init(fuse_init);
871 module_exit(fuse_exit);