Merge /spare/repo/linux-2.6/
[linux-2.6] / fs / fuse / inode.c
1 /*
2   FUSE: Filesystem in Userspace
3   Copyright (C) 2001-2005  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/mount.h>
15 #include <linux/seq_file.h>
16 #include <linux/init.h>
17 #include <linux/module.h>
18 #include <linux/parser.h>
19 #include <linux/statfs.h>
20
21 MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>");
22 MODULE_DESCRIPTION("Filesystem in Userspace");
23 MODULE_LICENSE("GPL");
24
25 spinlock_t fuse_lock;
26 static kmem_cache_t *fuse_inode_cachep;
27
28 #define FUSE_SUPER_MAGIC 0x65735546
29
30 struct fuse_mount_data {
31         int fd;
32         unsigned rootmode;
33         unsigned user_id;
34         unsigned group_id;
35         unsigned fd_present : 1;
36         unsigned rootmode_present : 1;
37         unsigned user_id_present : 1;
38         unsigned group_id_present : 1;
39         unsigned flags;
40         unsigned max_read;
41 };
42
43 static struct inode *fuse_alloc_inode(struct super_block *sb)
44 {
45         struct inode *inode;
46         struct fuse_inode *fi;
47
48         inode = kmem_cache_alloc(fuse_inode_cachep, SLAB_KERNEL);
49         if (!inode)
50                 return NULL;
51
52         fi = get_fuse_inode(inode);
53         fi->i_time = jiffies - 1;
54         fi->nodeid = 0;
55         fi->nlookup = 0;
56         fi->forget_req = fuse_request_alloc();
57         if (!fi->forget_req) {
58                 kmem_cache_free(fuse_inode_cachep, inode);
59                 return NULL;
60         }
61
62         return inode;
63 }
64
65 static void fuse_destroy_inode(struct inode *inode)
66 {
67         struct fuse_inode *fi = get_fuse_inode(inode);
68         if (fi->forget_req)
69                 fuse_request_free(fi->forget_req);
70         kmem_cache_free(fuse_inode_cachep, inode);
71 }
72
73 static void fuse_read_inode(struct inode *inode)
74 {
75         /* No op */
76 }
77
78 void fuse_send_forget(struct fuse_conn *fc, struct fuse_req *req,
79                       unsigned long nodeid, u64 nlookup)
80 {
81         struct fuse_forget_in *inarg = &req->misc.forget_in;
82         inarg->nlookup = nlookup;
83         req->in.h.opcode = FUSE_FORGET;
84         req->in.h.nodeid = nodeid;
85         req->in.numargs = 1;
86         req->in.args[0].size = sizeof(struct fuse_forget_in);
87         req->in.args[0].value = inarg;
88         request_send_noreply(fc, req);
89 }
90
91 static void fuse_clear_inode(struct inode *inode)
92 {
93         if (inode->i_sb->s_flags & MS_ACTIVE) {
94                 struct fuse_conn *fc = get_fuse_conn(inode);
95                 struct fuse_inode *fi = get_fuse_inode(inode);
96                 fuse_send_forget(fc, fi->forget_req, fi->nodeid, fi->nlookup);
97                 fi->forget_req = NULL;
98         }
99 }
100
101 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr)
102 {
103         if (S_ISREG(inode->i_mode) && i_size_read(inode) != attr->size)
104                 invalidate_inode_pages(inode->i_mapping);
105
106         inode->i_ino     = attr->ino;
107         inode->i_mode    = (inode->i_mode & S_IFMT) + (attr->mode & 07777);
108         inode->i_nlink   = attr->nlink;
109         inode->i_uid     = attr->uid;
110         inode->i_gid     = attr->gid;
111         i_size_write(inode, attr->size);
112         inode->i_blksize = PAGE_CACHE_SIZE;
113         inode->i_blocks  = attr->blocks;
114         inode->i_atime.tv_sec   = attr->atime;
115         inode->i_atime.tv_nsec  = attr->atimensec;
116         inode->i_mtime.tv_sec   = attr->mtime;
117         inode->i_mtime.tv_nsec  = attr->mtimensec;
118         inode->i_ctime.tv_sec   = attr->ctime;
119         inode->i_ctime.tv_nsec  = attr->ctimensec;
120 }
121
122 static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
123 {
124         inode->i_mode = attr->mode & S_IFMT;
125         i_size_write(inode, attr->size);
126         if (S_ISREG(inode->i_mode)) {
127                 fuse_init_common(inode);
128                 fuse_init_file_inode(inode);
129         } else if (S_ISDIR(inode->i_mode))
130                 fuse_init_dir(inode);
131         else if (S_ISLNK(inode->i_mode))
132                 fuse_init_symlink(inode);
133         else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
134                  S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
135                 fuse_init_common(inode);
136                 init_special_inode(inode, inode->i_mode,
137                                    new_decode_dev(attr->rdev));
138         } else {
139                 /* Don't let user create weird files */
140                 inode->i_mode = S_IFREG;
141                 fuse_init_common(inode);
142                 fuse_init_file_inode(inode);
143         }
144 }
145
146 static int fuse_inode_eq(struct inode *inode, void *_nodeidp)
147 {
148         unsigned long nodeid = *(unsigned long *) _nodeidp;
149         if (get_node_id(inode) == nodeid)
150                 return 1;
151         else
152                 return 0;
153 }
154
155 static int fuse_inode_set(struct inode *inode, void *_nodeidp)
156 {
157         unsigned long nodeid = *(unsigned long *) _nodeidp;
158         get_fuse_inode(inode)->nodeid = nodeid;
159         return 0;
160 }
161
162 struct inode *fuse_iget(struct super_block *sb, unsigned long nodeid,
163                         int generation, struct fuse_attr *attr)
164 {
165         struct inode *inode;
166         struct fuse_inode *fi;
167         struct fuse_conn *fc = get_fuse_conn_super(sb);
168         int retried = 0;
169
170  retry:
171         inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid);
172         if (!inode)
173                 return NULL;
174
175         if ((inode->i_state & I_NEW)) {
176                 inode->i_flags |= S_NOATIME|S_NOCMTIME;
177                 inode->i_generation = generation;
178                 inode->i_data.backing_dev_info = &fc->bdi;
179                 fuse_init_inode(inode, attr);
180                 unlock_new_inode(inode);
181         } else if ((inode->i_mode ^ attr->mode) & S_IFMT) {
182                 BUG_ON(retried);
183                 /* Inode has changed type, any I/O on the old should fail */
184                 make_bad_inode(inode);
185                 iput(inode);
186                 retried = 1;
187                 goto retry;
188         }
189
190         fi = get_fuse_inode(inode);
191         fi->nlookup ++;
192         fuse_change_attributes(inode, attr);
193         return inode;
194 }
195
196 static void fuse_put_super(struct super_block *sb)
197 {
198         struct fuse_conn *fc = get_fuse_conn_super(sb);
199
200         down_write(&fc->sbput_sem);
201         while (!list_empty(&fc->background))
202                 fuse_release_background(list_entry(fc->background.next,
203                                                    struct fuse_req, bg_entry));
204
205         spin_lock(&fuse_lock);
206         fc->mounted = 0;
207         fc->user_id = 0;
208         fc->group_id = 0;
209         fc->flags = 0;
210         /* Flush all readers on this fs */
211         wake_up_all(&fc->waitq);
212         up_write(&fc->sbput_sem);
213         fuse_release_conn(fc);
214         spin_unlock(&fuse_lock);
215 }
216
217 static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
218 {
219         stbuf->f_type    = FUSE_SUPER_MAGIC;
220         stbuf->f_bsize   = attr->bsize;
221         stbuf->f_blocks  = attr->blocks;
222         stbuf->f_bfree   = attr->bfree;
223         stbuf->f_bavail  = attr->bavail;
224         stbuf->f_files   = attr->files;
225         stbuf->f_ffree   = attr->ffree;
226         stbuf->f_namelen = attr->namelen;
227         /* fsid is left zero */
228 }
229
230 static int fuse_statfs(struct super_block *sb, struct kstatfs *buf)
231 {
232         struct fuse_conn *fc = get_fuse_conn_super(sb);
233         struct fuse_req *req;
234         struct fuse_statfs_out outarg;
235         int err;
236
237         req = fuse_get_request(fc);
238         if (!req)
239                 return -EINTR;
240
241         req->in.numargs = 0;
242         req->in.h.opcode = FUSE_STATFS;
243         req->out.numargs = 1;
244         req->out.args[0].size = sizeof(outarg);
245         req->out.args[0].value = &outarg;
246         request_send(fc, req);
247         err = req->out.h.error;
248         if (!err)
249                 convert_fuse_statfs(buf, &outarg.st);
250         fuse_put_request(fc, req);
251         return err;
252 }
253
254 enum {
255         OPT_FD,
256         OPT_ROOTMODE,
257         OPT_USER_ID,
258         OPT_GROUP_ID,
259         OPT_DEFAULT_PERMISSIONS,
260         OPT_ALLOW_OTHER,
261         OPT_MAX_READ,
262         OPT_ERR
263 };
264
265 static match_table_t tokens = {
266         {OPT_FD,                        "fd=%u"},
267         {OPT_ROOTMODE,                  "rootmode=%o"},
268         {OPT_USER_ID,                   "user_id=%u"},
269         {OPT_GROUP_ID,                  "group_id=%u"},
270         {OPT_DEFAULT_PERMISSIONS,       "default_permissions"},
271         {OPT_ALLOW_OTHER,               "allow_other"},
272         {OPT_MAX_READ,                  "max_read=%u"},
273         {OPT_ERR,                       NULL}
274 };
275
276 static int parse_fuse_opt(char *opt, struct fuse_mount_data *d)
277 {
278         char *p;
279         memset(d, 0, sizeof(struct fuse_mount_data));
280         d->max_read = ~0;
281
282         while ((p = strsep(&opt, ",")) != NULL) {
283                 int token;
284                 int value;
285                 substring_t args[MAX_OPT_ARGS];
286                 if (!*p)
287                         continue;
288
289                 token = match_token(p, tokens, args);
290                 switch (token) {
291                 case OPT_FD:
292                         if (match_int(&args[0], &value))
293                                 return 0;
294                         d->fd = value;
295                         d->fd_present = 1;
296                         break;
297
298                 case OPT_ROOTMODE:
299                         if (match_octal(&args[0], &value))
300                                 return 0;
301                         d->rootmode = value;
302                         d->rootmode_present = 1;
303                         break;
304
305                 case OPT_USER_ID:
306                         if (match_int(&args[0], &value))
307                                 return 0;
308                         d->user_id = value;
309                         d->user_id_present = 1;
310                         break;
311
312                 case OPT_GROUP_ID:
313                         if (match_int(&args[0], &value))
314                                 return 0;
315                         d->group_id = value;
316                         d->group_id_present = 1;
317                         break;
318
319                 case OPT_DEFAULT_PERMISSIONS:
320                         d->flags |= FUSE_DEFAULT_PERMISSIONS;
321                         break;
322
323                 case OPT_ALLOW_OTHER:
324                         d->flags |= FUSE_ALLOW_OTHER;
325                         break;
326
327                 case OPT_MAX_READ:
328                         if (match_int(&args[0], &value))
329                                 return 0;
330                         d->max_read = value;
331                         break;
332
333                 default:
334                         return 0;
335                 }
336         }
337
338         if (!d->fd_present || !d->rootmode_present ||
339             !d->user_id_present || !d->group_id_present)
340                 return 0;
341
342         return 1;
343 }
344
345 static int fuse_show_options(struct seq_file *m, struct vfsmount *mnt)
346 {
347         struct fuse_conn *fc = get_fuse_conn_super(mnt->mnt_sb);
348
349         seq_printf(m, ",user_id=%u", fc->user_id);
350         seq_printf(m, ",group_id=%u", fc->group_id);
351         if (fc->flags & FUSE_DEFAULT_PERMISSIONS)
352                 seq_puts(m, ",default_permissions");
353         if (fc->flags & FUSE_ALLOW_OTHER)
354                 seq_puts(m, ",allow_other");
355         if (fc->max_read != ~0)
356                 seq_printf(m, ",max_read=%u", fc->max_read);
357         return 0;
358 }
359
360 static void free_conn(struct fuse_conn *fc)
361 {
362         while (!list_empty(&fc->unused_list)) {
363                 struct fuse_req *req;
364                 req = list_entry(fc->unused_list.next, struct fuse_req, list);
365                 list_del(&req->list);
366                 fuse_request_free(req);
367         }
368         kfree(fc);
369 }
370
371 /* Must be called with the fuse lock held */
372 void fuse_release_conn(struct fuse_conn *fc)
373 {
374         fc->count--;
375         if (!fc->count)
376                 free_conn(fc);
377 }
378
379 static struct fuse_conn *new_conn(void)
380 {
381         struct fuse_conn *fc;
382
383         fc = kmalloc(sizeof(*fc), GFP_KERNEL);
384         if (fc != NULL) {
385                 int i;
386                 memset(fc, 0, sizeof(*fc));
387                 init_waitqueue_head(&fc->waitq);
388                 INIT_LIST_HEAD(&fc->pending);
389                 INIT_LIST_HEAD(&fc->processing);
390                 INIT_LIST_HEAD(&fc->unused_list);
391                 INIT_LIST_HEAD(&fc->background);
392                 sema_init(&fc->outstanding_sem, 0);
393                 init_rwsem(&fc->sbput_sem);
394                 for (i = 0; i < FUSE_MAX_OUTSTANDING; i++) {
395                         struct fuse_req *req = fuse_request_alloc();
396                         if (!req) {
397                                 free_conn(fc);
398                                 return NULL;
399                         }
400                         list_add(&req->list, &fc->unused_list);
401                 }
402                 fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
403                 fc->bdi.unplug_io_fn = default_unplug_io_fn;
404                 fc->reqctr = 0;
405         }
406         return fc;
407 }
408
409 static struct fuse_conn *get_conn(struct file *file, struct super_block *sb)
410 {
411         struct fuse_conn *fc;
412
413         if (file->f_op != &fuse_dev_operations)
414                 return ERR_PTR(-EINVAL);
415         fc = new_conn();
416         if (fc == NULL)
417                 return ERR_PTR(-ENOMEM);
418         spin_lock(&fuse_lock);
419         if (file->private_data) {
420                 free_conn(fc);
421                 fc = ERR_PTR(-EINVAL);
422         } else {
423                 file->private_data = fc;
424                 *get_fuse_conn_super_p(sb) = fc;
425                 fc->mounted = 1;
426                 fc->connected = 1;
427                 fc->count = 2;
428         }
429         spin_unlock(&fuse_lock);
430         return fc;
431 }
432
433 static struct inode *get_root_inode(struct super_block *sb, unsigned mode)
434 {
435         struct fuse_attr attr;
436         memset(&attr, 0, sizeof(attr));
437
438         attr.mode = mode;
439         attr.ino = FUSE_ROOT_ID;
440         return fuse_iget(sb, 1, 0, &attr);
441 }
442
443 static struct super_operations fuse_super_operations = {
444         .alloc_inode    = fuse_alloc_inode,
445         .destroy_inode  = fuse_destroy_inode,
446         .read_inode     = fuse_read_inode,
447         .clear_inode    = fuse_clear_inode,
448         .put_super      = fuse_put_super,
449         .statfs         = fuse_statfs,
450         .show_options   = fuse_show_options,
451 };
452
453 static int fuse_fill_super(struct super_block *sb, void *data, int silent)
454 {
455         struct fuse_conn *fc;
456         struct inode *root;
457         struct fuse_mount_data d;
458         struct file *file;
459         int err;
460
461         if (!parse_fuse_opt((char *) data, &d))
462                 return -EINVAL;
463
464         sb->s_blocksize = PAGE_CACHE_SIZE;
465         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
466         sb->s_magic = FUSE_SUPER_MAGIC;
467         sb->s_op = &fuse_super_operations;
468         sb->s_maxbytes = MAX_LFS_FILESIZE;
469
470         file = fget(d.fd);
471         if (!file)
472                 return -EINVAL;
473
474         fc = get_conn(file, sb);
475         fput(file);
476         if (IS_ERR(fc))
477                 return PTR_ERR(fc);
478
479         fc->flags = d.flags;
480         fc->user_id = d.user_id;
481         fc->group_id = d.group_id;
482         fc->max_read = d.max_read;
483         if (fc->max_read / PAGE_CACHE_SIZE < fc->bdi.ra_pages)
484                 fc->bdi.ra_pages = fc->max_read / PAGE_CACHE_SIZE;
485         fc->max_write = FUSE_MAX_IN / 2;
486
487         err = -ENOMEM;
488         root = get_root_inode(sb, d.rootmode);
489         if (root == NULL)
490                 goto err;
491
492         sb->s_root = d_alloc_root(root);
493         if (!sb->s_root) {
494                 iput(root);
495                 goto err;
496         }
497         fuse_send_init(fc);
498         return 0;
499
500  err:
501         spin_lock(&fuse_lock);
502         fuse_release_conn(fc);
503         spin_unlock(&fuse_lock);
504         return err;
505 }
506
507 static struct super_block *fuse_get_sb(struct file_system_type *fs_type,
508                                        int flags, const char *dev_name,
509                                        void *raw_data)
510 {
511         return get_sb_nodev(fs_type, flags, raw_data, fuse_fill_super);
512 }
513
514 static struct file_system_type fuse_fs_type = {
515         .owner          = THIS_MODULE,
516         .name           = "fuse",
517         .get_sb         = fuse_get_sb,
518         .kill_sb        = kill_anon_super,
519 };
520
521 static void fuse_inode_init_once(void *foo, kmem_cache_t *cachep,
522                                  unsigned long flags)
523 {
524         struct inode * inode = foo;
525
526         if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
527             SLAB_CTOR_CONSTRUCTOR)
528                 inode_init_once(inode);
529 }
530
531 static int __init fuse_fs_init(void)
532 {
533         int err;
534
535         err = register_filesystem(&fuse_fs_type);
536         if (err)
537                 printk("fuse: failed to register filesystem\n");
538         else {
539                 fuse_inode_cachep = kmem_cache_create("fuse_inode",
540                                                       sizeof(struct fuse_inode),
541                                                       0, SLAB_HWCACHE_ALIGN,
542                                                       fuse_inode_init_once, NULL);
543                 if (!fuse_inode_cachep) {
544                         unregister_filesystem(&fuse_fs_type);
545                         err = -ENOMEM;
546                 }
547         }
548
549         return err;
550 }
551
552 static void fuse_fs_cleanup(void)
553 {
554         unregister_filesystem(&fuse_fs_type);
555         kmem_cache_destroy(fuse_inode_cachep);
556 }
557
558 static int __init fuse_init(void)
559 {
560         int res;
561
562         printk("fuse init (API version %i.%i)\n",
563                FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
564
565         spin_lock_init(&fuse_lock);
566         res = fuse_fs_init();
567         if (res)
568                 goto err;
569
570         res = fuse_dev_init();
571         if (res)
572                 goto err_fs_cleanup;
573
574         return 0;
575
576  err_fs_cleanup:
577         fuse_fs_cleanup();
578  err:
579         return res;
580 }
581
582 static void __exit fuse_exit(void)
583 {
584         printk(KERN_DEBUG "fuse exit\n");
585
586         fuse_fs_cleanup();
587         fuse_dev_cleanup();
588 }
589
590 module_init(fuse_init);
591 module_exit(fuse_exit);