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