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Commit | Line | Data |
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d8a5ba45 MS |
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/moduleparam.h> | |
19 | #include <linux/parser.h> | |
20 | #include <linux/statfs.h> | |
21 | ||
22 | MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>"); | |
23 | MODULE_DESCRIPTION("Filesystem in Userspace"); | |
24 | MODULE_LICENSE("GPL"); | |
25 | ||
26 | spinlock_t fuse_lock; | |
27 | static kmem_cache_t *fuse_inode_cachep; | |
28 | static int mount_count; | |
29 | ||
30 | static int mount_max = 1000; | |
31 | module_param(mount_max, int, 0644); | |
32 | MODULE_PARM_DESC(mount_max, "Maximum number of FUSE mounts allowed, if -1 then unlimited (default: 1000)"); | |
33 | ||
34 | #define FUSE_SUPER_MAGIC 0x65735546 | |
35 | ||
36 | struct fuse_mount_data { | |
37 | int fd; | |
38 | unsigned rootmode; | |
39 | unsigned user_id; | |
40 | }; | |
41 | ||
42 | static struct inode *fuse_alloc_inode(struct super_block *sb) | |
43 | { | |
44 | struct inode *inode; | |
45 | struct fuse_inode *fi; | |
46 | ||
47 | inode = kmem_cache_alloc(fuse_inode_cachep, SLAB_KERNEL); | |
48 | if (!inode) | |
49 | return NULL; | |
50 | ||
51 | fi = get_fuse_inode(inode); | |
52 | fi->i_time = jiffies - 1; | |
53 | fi->nodeid = 0; | |
e5e5558e MS |
54 | fi->forget_req = fuse_request_alloc(); |
55 | if (!fi->forget_req) { | |
56 | kmem_cache_free(fuse_inode_cachep, inode); | |
57 | return NULL; | |
58 | } | |
d8a5ba45 MS |
59 | |
60 | return inode; | |
61 | } | |
62 | ||
63 | static void fuse_destroy_inode(struct inode *inode) | |
64 | { | |
e5e5558e MS |
65 | struct fuse_inode *fi = get_fuse_inode(inode); |
66 | if (fi->forget_req) | |
67 | fuse_request_free(fi->forget_req); | |
d8a5ba45 MS |
68 | kmem_cache_free(fuse_inode_cachep, inode); |
69 | } | |
70 | ||
71 | static void fuse_read_inode(struct inode *inode) | |
72 | { | |
73 | /* No op */ | |
74 | } | |
75 | ||
e5e5558e MS |
76 | void fuse_send_forget(struct fuse_conn *fc, struct fuse_req *req, |
77 | unsigned long nodeid, int version) | |
78 | { | |
79 | struct fuse_forget_in *inarg = &req->misc.forget_in; | |
80 | inarg->version = version; | |
81 | req->in.h.opcode = FUSE_FORGET; | |
82 | req->in.h.nodeid = nodeid; | |
83 | req->in.numargs = 1; | |
84 | req->in.args[0].size = sizeof(struct fuse_forget_in); | |
85 | req->in.args[0].value = inarg; | |
86 | request_send_noreply(fc, req); | |
87 | } | |
88 | ||
d8a5ba45 MS |
89 | static void fuse_clear_inode(struct inode *inode) |
90 | { | |
e5e5558e MS |
91 | struct fuse_conn *fc = get_fuse_conn(inode); |
92 | if (fc) { | |
93 | struct fuse_inode *fi = get_fuse_inode(inode); | |
94 | fuse_send_forget(fc, fi->forget_req, fi->nodeid, inode->i_version); | |
95 | fi->forget_req = NULL; | |
96 | } | |
d8a5ba45 MS |
97 | } |
98 | ||
99 | void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr) | |
100 | { | |
101 | if (S_ISREG(inode->i_mode) && i_size_read(inode) != attr->size) | |
102 | invalidate_inode_pages(inode->i_mapping); | |
103 | ||
104 | inode->i_ino = attr->ino; | |
105 | inode->i_mode = (inode->i_mode & S_IFMT) + (attr->mode & 07777); | |
106 | inode->i_nlink = attr->nlink; | |
107 | inode->i_uid = attr->uid; | |
108 | inode->i_gid = attr->gid; | |
109 | i_size_write(inode, attr->size); | |
110 | inode->i_blksize = PAGE_CACHE_SIZE; | |
111 | inode->i_blocks = attr->blocks; | |
112 | inode->i_atime.tv_sec = attr->atime; | |
113 | inode->i_atime.tv_nsec = attr->atimensec; | |
114 | inode->i_mtime.tv_sec = attr->mtime; | |
115 | inode->i_mtime.tv_nsec = attr->mtimensec; | |
116 | inode->i_ctime.tv_sec = attr->ctime; | |
117 | inode->i_ctime.tv_nsec = attr->ctimensec; | |
118 | } | |
119 | ||
120 | static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr) | |
121 | { | |
122 | inode->i_mode = attr->mode & S_IFMT; | |
123 | i_size_write(inode, attr->size); | |
e5e5558e MS |
124 | if (S_ISREG(inode->i_mode)) { |
125 | fuse_init_common(inode); | |
126 | } else if (S_ISDIR(inode->i_mode)) | |
127 | fuse_init_dir(inode); | |
128 | else if (S_ISLNK(inode->i_mode)) | |
129 | fuse_init_symlink(inode); | |
130 | else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) || | |
131 | S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) { | |
132 | fuse_init_common(inode); | |
133 | init_special_inode(inode, inode->i_mode, | |
134 | new_decode_dev(attr->rdev)); | |
135 | } else { | |
136 | /* Don't let user create weird files */ | |
137 | inode->i_mode = S_IFREG; | |
138 | fuse_init_common(inode); | |
139 | } | |
d8a5ba45 MS |
140 | } |
141 | ||
142 | static int fuse_inode_eq(struct inode *inode, void *_nodeidp) | |
143 | { | |
144 | unsigned long nodeid = *(unsigned long *) _nodeidp; | |
145 | if (get_node_id(inode) == nodeid) | |
146 | return 1; | |
147 | else | |
148 | return 0; | |
149 | } | |
150 | ||
151 | static int fuse_inode_set(struct inode *inode, void *_nodeidp) | |
152 | { | |
153 | unsigned long nodeid = *(unsigned long *) _nodeidp; | |
154 | get_fuse_inode(inode)->nodeid = nodeid; | |
155 | return 0; | |
156 | } | |
157 | ||
158 | struct inode *fuse_iget(struct super_block *sb, unsigned long nodeid, | |
159 | int generation, struct fuse_attr *attr, int version) | |
160 | { | |
161 | struct inode *inode; | |
162 | struct fuse_conn *fc = get_fuse_conn_super(sb); | |
163 | int retried = 0; | |
164 | ||
165 | retry: | |
166 | inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid); | |
167 | if (!inode) | |
168 | return NULL; | |
169 | ||
170 | if ((inode->i_state & I_NEW)) { | |
171 | inode->i_generation = generation; | |
172 | inode->i_data.backing_dev_info = &fc->bdi; | |
173 | fuse_init_inode(inode, attr); | |
174 | unlock_new_inode(inode); | |
175 | } else if ((inode->i_mode ^ attr->mode) & S_IFMT) { | |
176 | BUG_ON(retried); | |
177 | /* Inode has changed type, any I/O on the old should fail */ | |
178 | make_bad_inode(inode); | |
179 | iput(inode); | |
180 | retried = 1; | |
181 | goto retry; | |
182 | } | |
183 | ||
184 | fuse_change_attributes(inode, attr); | |
185 | inode->i_version = version; | |
186 | return inode; | |
187 | } | |
188 | ||
189 | static void fuse_put_super(struct super_block *sb) | |
190 | { | |
191 | struct fuse_conn *fc = get_fuse_conn_super(sb); | |
192 | ||
193 | spin_lock(&fuse_lock); | |
194 | mount_count --; | |
195 | fc->sb = NULL; | |
196 | fc->user_id = 0; | |
334f485d MS |
197 | /* Flush all readers on this fs */ |
198 | wake_up_all(&fc->waitq); | |
d8a5ba45 MS |
199 | fuse_release_conn(fc); |
200 | *get_fuse_conn_super_p(sb) = NULL; | |
201 | spin_unlock(&fuse_lock); | |
202 | } | |
203 | ||
e5e5558e MS |
204 | static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr) |
205 | { | |
206 | stbuf->f_type = FUSE_SUPER_MAGIC; | |
207 | stbuf->f_bsize = attr->bsize; | |
208 | stbuf->f_blocks = attr->blocks; | |
209 | stbuf->f_bfree = attr->bfree; | |
210 | stbuf->f_bavail = attr->bavail; | |
211 | stbuf->f_files = attr->files; | |
212 | stbuf->f_ffree = attr->ffree; | |
213 | stbuf->f_namelen = attr->namelen; | |
214 | /* fsid is left zero */ | |
215 | } | |
216 | ||
217 | static int fuse_statfs(struct super_block *sb, struct kstatfs *buf) | |
218 | { | |
219 | struct fuse_conn *fc = get_fuse_conn_super(sb); | |
220 | struct fuse_req *req; | |
221 | struct fuse_statfs_out outarg; | |
222 | int err; | |
223 | ||
224 | req = fuse_get_request(fc); | |
225 | if (!req) | |
226 | return -ERESTARTSYS; | |
227 | ||
228 | req->in.numargs = 0; | |
229 | req->in.h.opcode = FUSE_STATFS; | |
230 | req->out.numargs = 1; | |
231 | req->out.args[0].size = sizeof(outarg); | |
232 | req->out.args[0].value = &outarg; | |
233 | request_send(fc, req); | |
234 | err = req->out.h.error; | |
235 | if (!err) | |
236 | convert_fuse_statfs(buf, &outarg.st); | |
237 | fuse_put_request(fc, req); | |
238 | return err; | |
239 | } | |
240 | ||
d8a5ba45 MS |
241 | enum { |
242 | OPT_FD, | |
243 | OPT_ROOTMODE, | |
244 | OPT_USER_ID, | |
245 | OPT_DEFAULT_PERMISSIONS, | |
246 | OPT_ALLOW_OTHER, | |
247 | OPT_ALLOW_ROOT, | |
248 | OPT_KERNEL_CACHE, | |
249 | OPT_ERR | |
250 | }; | |
251 | ||
252 | static match_table_t tokens = { | |
253 | {OPT_FD, "fd=%u"}, | |
254 | {OPT_ROOTMODE, "rootmode=%o"}, | |
255 | {OPT_USER_ID, "user_id=%u"}, | |
256 | {OPT_DEFAULT_PERMISSIONS, "default_permissions"}, | |
257 | {OPT_ALLOW_OTHER, "allow_other"}, | |
258 | {OPT_ALLOW_ROOT, "allow_root"}, | |
259 | {OPT_KERNEL_CACHE, "kernel_cache"}, | |
260 | {OPT_ERR, NULL} | |
261 | }; | |
262 | ||
263 | static int parse_fuse_opt(char *opt, struct fuse_mount_data *d) | |
264 | { | |
265 | char *p; | |
266 | memset(d, 0, sizeof(struct fuse_mount_data)); | |
267 | d->fd = -1; | |
268 | ||
269 | while ((p = strsep(&opt, ",")) != NULL) { | |
270 | int token; | |
271 | int value; | |
272 | substring_t args[MAX_OPT_ARGS]; | |
273 | if (!*p) | |
274 | continue; | |
275 | ||
276 | token = match_token(p, tokens, args); | |
277 | switch (token) { | |
278 | case OPT_FD: | |
279 | if (match_int(&args[0], &value)) | |
280 | return 0; | |
281 | d->fd = value; | |
282 | break; | |
283 | ||
284 | case OPT_ROOTMODE: | |
285 | if (match_octal(&args[0], &value)) | |
286 | return 0; | |
287 | d->rootmode = value; | |
288 | break; | |
289 | ||
290 | case OPT_USER_ID: | |
291 | if (match_int(&args[0], &value)) | |
292 | return 0; | |
293 | d->user_id = value; | |
294 | break; | |
295 | ||
296 | default: | |
297 | return 0; | |
298 | } | |
299 | } | |
300 | if (d->fd == -1) | |
301 | return 0; | |
302 | ||
303 | return 1; | |
304 | } | |
305 | ||
306 | static int fuse_show_options(struct seq_file *m, struct vfsmount *mnt) | |
307 | { | |
308 | struct fuse_conn *fc = get_fuse_conn_super(mnt->mnt_sb); | |
309 | ||
310 | seq_printf(m, ",user_id=%u", fc->user_id); | |
311 | return 0; | |
312 | } | |
313 | ||
334f485d | 314 | static void free_conn(struct fuse_conn *fc) |
d8a5ba45 | 315 | { |
334f485d MS |
316 | while (!list_empty(&fc->unused_list)) { |
317 | struct fuse_req *req; | |
318 | req = list_entry(fc->unused_list.next, struct fuse_req, list); | |
319 | list_del(&req->list); | |
320 | fuse_request_free(req); | |
321 | } | |
d8a5ba45 MS |
322 | kfree(fc); |
323 | } | |
324 | ||
334f485d MS |
325 | /* Must be called with the fuse lock held */ |
326 | void fuse_release_conn(struct fuse_conn *fc) | |
327 | { | |
328 | if (!fc->sb && !fc->file) | |
329 | free_conn(fc); | |
330 | } | |
331 | ||
d8a5ba45 MS |
332 | static struct fuse_conn *new_conn(void) |
333 | { | |
334 | struct fuse_conn *fc; | |
335 | ||
336 | fc = kmalloc(sizeof(*fc), GFP_KERNEL); | |
337 | if (fc != NULL) { | |
334f485d | 338 | int i; |
d8a5ba45 MS |
339 | memset(fc, 0, sizeof(*fc)); |
340 | fc->sb = NULL; | |
334f485d | 341 | fc->file = NULL; |
d8a5ba45 | 342 | fc->user_id = 0; |
334f485d MS |
343 | init_waitqueue_head(&fc->waitq); |
344 | INIT_LIST_HEAD(&fc->pending); | |
345 | INIT_LIST_HEAD(&fc->processing); | |
346 | INIT_LIST_HEAD(&fc->unused_list); | |
347 | sema_init(&fc->outstanding_sem, 0); | |
348 | for (i = 0; i < FUSE_MAX_OUTSTANDING; i++) { | |
349 | struct fuse_req *req = fuse_request_alloc(); | |
350 | if (!req) { | |
351 | free_conn(fc); | |
352 | return NULL; | |
353 | } | |
354 | list_add(&req->list, &fc->unused_list); | |
355 | } | |
d8a5ba45 MS |
356 | fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE; |
357 | fc->bdi.unplug_io_fn = default_unplug_io_fn; | |
334f485d | 358 | fc->reqctr = 0; |
d8a5ba45 MS |
359 | } |
360 | return fc; | |
361 | } | |
362 | ||
363 | static struct fuse_conn *get_conn(struct file *file, struct super_block *sb) | |
364 | { | |
365 | struct fuse_conn *fc; | |
366 | ||
334f485d MS |
367 | if (file->f_op != &fuse_dev_operations) |
368 | return ERR_PTR(-EINVAL); | |
d8a5ba45 MS |
369 | fc = new_conn(); |
370 | if (fc == NULL) | |
334f485d | 371 | return ERR_PTR(-ENOMEM); |
d8a5ba45 | 372 | spin_lock(&fuse_lock); |
334f485d MS |
373 | if (file->private_data) { |
374 | free_conn(fc); | |
375 | fc = ERR_PTR(-EINVAL); | |
376 | } else { | |
377 | file->private_data = fc; | |
378 | fc->sb = sb; | |
379 | fc->file = file; | |
380 | } | |
d8a5ba45 MS |
381 | spin_unlock(&fuse_lock); |
382 | return fc; | |
383 | } | |
384 | ||
385 | static struct inode *get_root_inode(struct super_block *sb, unsigned mode) | |
386 | { | |
387 | struct fuse_attr attr; | |
388 | memset(&attr, 0, sizeof(attr)); | |
389 | ||
390 | attr.mode = mode; | |
391 | attr.ino = FUSE_ROOT_ID; | |
392 | return fuse_iget(sb, 1, 0, &attr, 0); | |
393 | } | |
394 | ||
395 | static struct super_operations fuse_super_operations = { | |
396 | .alloc_inode = fuse_alloc_inode, | |
397 | .destroy_inode = fuse_destroy_inode, | |
398 | .read_inode = fuse_read_inode, | |
399 | .clear_inode = fuse_clear_inode, | |
400 | .put_super = fuse_put_super, | |
e5e5558e | 401 | .statfs = fuse_statfs, |
d8a5ba45 MS |
402 | .show_options = fuse_show_options, |
403 | }; | |
404 | ||
405 | static int inc_mount_count(void) | |
406 | { | |
407 | int success = 0; | |
408 | spin_lock(&fuse_lock); | |
409 | mount_count ++; | |
410 | if (mount_max == -1 || mount_count <= mount_max) | |
411 | success = 1; | |
412 | spin_unlock(&fuse_lock); | |
413 | return success; | |
414 | } | |
415 | ||
416 | static int fuse_fill_super(struct super_block *sb, void *data, int silent) | |
417 | { | |
418 | struct fuse_conn *fc; | |
419 | struct inode *root; | |
420 | struct fuse_mount_data d; | |
421 | struct file *file; | |
422 | int err; | |
423 | ||
424 | if (!parse_fuse_opt((char *) data, &d)) | |
425 | return -EINVAL; | |
426 | ||
427 | sb->s_blocksize = PAGE_CACHE_SIZE; | |
428 | sb->s_blocksize_bits = PAGE_CACHE_SHIFT; | |
429 | sb->s_magic = FUSE_SUPER_MAGIC; | |
430 | sb->s_op = &fuse_super_operations; | |
431 | sb->s_maxbytes = MAX_LFS_FILESIZE; | |
432 | ||
433 | file = fget(d.fd); | |
434 | if (!file) | |
435 | return -EINVAL; | |
436 | ||
437 | fc = get_conn(file, sb); | |
438 | fput(file); | |
334f485d MS |
439 | if (IS_ERR(fc)) |
440 | return PTR_ERR(fc); | |
d8a5ba45 MS |
441 | |
442 | fc->user_id = d.user_id; | |
443 | ||
444 | *get_fuse_conn_super_p(sb) = fc; | |
445 | ||
446 | err = -ENFILE; | |
447 | if (!inc_mount_count() && current->uid != 0) | |
448 | goto err; | |
449 | ||
450 | err = -ENOMEM; | |
451 | root = get_root_inode(sb, d.rootmode); | |
452 | if (root == NULL) | |
453 | goto err; | |
454 | ||
455 | sb->s_root = d_alloc_root(root); | |
456 | if (!sb->s_root) { | |
457 | iput(root); | |
458 | goto err; | |
459 | } | |
334f485d | 460 | fuse_send_init(fc); |
d8a5ba45 MS |
461 | return 0; |
462 | ||
463 | err: | |
464 | spin_lock(&fuse_lock); | |
465 | mount_count --; | |
466 | fc->sb = NULL; | |
467 | fuse_release_conn(fc); | |
468 | spin_unlock(&fuse_lock); | |
469 | *get_fuse_conn_super_p(sb) = NULL; | |
470 | return err; | |
471 | } | |
472 | ||
473 | static struct super_block *fuse_get_sb(struct file_system_type *fs_type, | |
474 | int flags, const char *dev_name, | |
475 | void *raw_data) | |
476 | { | |
477 | return get_sb_nodev(fs_type, flags, raw_data, fuse_fill_super); | |
478 | } | |
479 | ||
480 | static struct file_system_type fuse_fs_type = { | |
481 | .owner = THIS_MODULE, | |
482 | .name = "fuse", | |
483 | .get_sb = fuse_get_sb, | |
484 | .kill_sb = kill_anon_super, | |
485 | }; | |
486 | ||
487 | static void fuse_inode_init_once(void *foo, kmem_cache_t *cachep, | |
488 | unsigned long flags) | |
489 | { | |
490 | struct inode * inode = foo; | |
491 | ||
492 | if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) == | |
493 | SLAB_CTOR_CONSTRUCTOR) | |
494 | inode_init_once(inode); | |
495 | } | |
496 | ||
497 | static int __init fuse_fs_init(void) | |
498 | { | |
499 | int err; | |
500 | ||
501 | err = register_filesystem(&fuse_fs_type); | |
502 | if (err) | |
503 | printk("fuse: failed to register filesystem\n"); | |
504 | else { | |
505 | fuse_inode_cachep = kmem_cache_create("fuse_inode", | |
506 | sizeof(struct fuse_inode), | |
507 | 0, SLAB_HWCACHE_ALIGN, | |
508 | fuse_inode_init_once, NULL); | |
509 | if (!fuse_inode_cachep) { | |
510 | unregister_filesystem(&fuse_fs_type); | |
511 | err = -ENOMEM; | |
512 | } | |
513 | } | |
514 | ||
515 | return err; | |
516 | } | |
517 | ||
518 | static void fuse_fs_cleanup(void) | |
519 | { | |
520 | unregister_filesystem(&fuse_fs_type); | |
521 | kmem_cache_destroy(fuse_inode_cachep); | |
522 | } | |
523 | ||
524 | static int __init fuse_init(void) | |
525 | { | |
526 | int res; | |
527 | ||
528 | printk("fuse init (API version %i.%i)\n", | |
529 | FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION); | |
530 | ||
531 | spin_lock_init(&fuse_lock); | |
532 | res = fuse_fs_init(); | |
533 | if (res) | |
534 | goto err; | |
535 | ||
334f485d MS |
536 | res = fuse_dev_init(); |
537 | if (res) | |
538 | goto err_fs_cleanup; | |
539 | ||
d8a5ba45 MS |
540 | return 0; |
541 | ||
334f485d MS |
542 | err_fs_cleanup: |
543 | fuse_fs_cleanup(); | |
d8a5ba45 MS |
544 | err: |
545 | return res; | |
546 | } | |
547 | ||
548 | static void __exit fuse_exit(void) | |
549 | { | |
550 | printk(KERN_DEBUG "fuse exit\n"); | |
551 | ||
552 | fuse_fs_cleanup(); | |
334f485d | 553 | fuse_dev_cleanup(); |
d8a5ba45 MS |
554 | } |
555 | ||
556 | module_init(fuse_init); | |
557 | module_exit(fuse_exit); |