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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); |