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Blackfin: drop unneeded asm/.gitignore
[linux-2.6/mini2440.git] / fs / fuse / inode.c
blob91f7c85f1ffd7e52f8aa9d61c6f309cd8ed5bf42
1 /*
2 FUSE: Filesystem in Userspace
3 Copyright (C) 2001-2008 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 #include <linux/exportfs.h>
22 #include <linux/smp_lock.h>
23
24 MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>");
25 MODULE_DESCRIPTION("Filesystem in Userspace");
26 MODULE_LICENSE("GPL");
27
28 static struct kmem_cache *fuse_inode_cachep;
29 struct list_head fuse_conn_list;
30 DEFINE_MUTEX(fuse_mutex);
31
32 #define FUSE_SUPER_MAGIC 0x65735546
33
34 #define FUSE_DEFAULT_BLKSIZE 512
35
36 struct fuse_mount_data {
37 int fd;
38 unsigned rootmode;
39 unsigned user_id;
40 unsigned group_id;
41 unsigned fd_present:1;
42 unsigned rootmode_present:1;
43 unsigned user_id_present:1;
44 unsigned group_id_present:1;
45 unsigned flags;
46 unsigned max_read;
47 unsigned blksize;
48 };
49
50 static struct inode *fuse_alloc_inode(struct super_block *sb)
51 {
52 struct inode *inode;
53 struct fuse_inode *fi;
54
55 inode = kmem_cache_alloc(fuse_inode_cachep, GFP_KERNEL);
56 if (!inode)
57 return NULL;
58
59 fi = get_fuse_inode(inode);
60 fi->i_time = 0;
61 fi->nodeid = 0;
62 fi->nlookup = 0;
63 fi->attr_version = 0;
64 fi->writectr = 0;
65 INIT_LIST_HEAD(&fi->write_files);
66 INIT_LIST_HEAD(&fi->queued_writes);
67 INIT_LIST_HEAD(&fi->writepages);
68 init_waitqueue_head(&fi->page_waitq);
69 fi->forget_req = fuse_request_alloc();
70 if (!fi->forget_req) {
71 kmem_cache_free(fuse_inode_cachep, inode);
72 return NULL;
73 }
74
75 return inode;
76 }
77
78 static void fuse_destroy_inode(struct inode *inode)
79 {
80 struct fuse_inode *fi = get_fuse_inode(inode);
81 BUG_ON(!list_empty(&fi->write_files));
82 BUG_ON(!list_empty(&fi->queued_writes));
83 if (fi->forget_req)
84 fuse_request_free(fi->forget_req);
85 kmem_cache_free(fuse_inode_cachep, inode);
86 }
87
88 void fuse_send_forget(struct fuse_conn *fc, struct fuse_req *req,
89 u64 nodeid, u64 nlookup)
90 {
91 struct fuse_forget_in *inarg = &req->misc.forget_in;
92 inarg->nlookup = nlookup;
93 req->in.h.opcode = FUSE_FORGET;
94 req->in.h.nodeid = nodeid;
95 req->in.numargs = 1;
96 req->in.args[0].size = sizeof(struct fuse_forget_in);
97 req->in.args[0].value = inarg;
98 fuse_request_send_noreply(fc, req);
99 }
100
101 static void fuse_clear_inode(struct inode *inode)
102 {
103 if (inode->i_sb->s_flags & MS_ACTIVE) {
104 struct fuse_conn *fc = get_fuse_conn(inode);
105 struct fuse_inode *fi = get_fuse_inode(inode);
106 fuse_send_forget(fc, fi->forget_req, fi->nodeid, fi->nlookup);
107 fi->forget_req = NULL;
108 }
109 }
110
111 static int fuse_remount_fs(struct super_block *sb, int *flags, char *data)
112 {
113 if (*flags & MS_MANDLOCK)
114 return -EINVAL;
115
116 return 0;
117 }
118
119 void fuse_truncate(struct address_space *mapping, loff_t offset)
120 {
121 /* See vmtruncate() */
122 unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1);
123 truncate_inode_pages(mapping, offset);
124 unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1);
125 }
126
127 void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
128 u64 attr_valid)
129 {
130 struct fuse_conn *fc = get_fuse_conn(inode);
131 struct fuse_inode *fi = get_fuse_inode(inode);
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
164 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
165 u64 attr_valid, u64 attr_version)
166 {
167 struct fuse_conn *fc = get_fuse_conn(inode);
168 struct fuse_inode *fi = get_fuse_inode(inode);
169 loff_t oldsize;
170
171 spin_lock(&fc->lock);
172 if (attr_version != 0 && fi->attr_version > attr_version) {
173 spin_unlock(&fc->lock);
174 return;
175 }
176
177 fuse_change_attributes_common(inode, attr, attr_valid);
178
179 oldsize = inode->i_size;
180 i_size_write(inode, attr->size);
181 spin_unlock(&fc->lock);
182
183 if (S_ISREG(inode->i_mode) && oldsize != attr->size) {
184 if (attr->size < oldsize)
185 fuse_truncate(inode->i_mapping, attr->size);
186 invalidate_inode_pages2(inode->i_mapping);
187 }
188 }
189
190 static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
191 {
192 inode->i_mode = attr->mode & S_IFMT;
193 inode->i_size = attr->size;
194 if (S_ISREG(inode->i_mode)) {
195 fuse_init_common(inode);
196 fuse_init_file_inode(inode);
197 } else if (S_ISDIR(inode->i_mode))
198 fuse_init_dir(inode);
199 else if (S_ISLNK(inode->i_mode))
200 fuse_init_symlink(inode);
201 else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
202 S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
203 fuse_init_common(inode);
204 init_special_inode(inode, inode->i_mode,
205 new_decode_dev(attr->rdev));
206 } else
207 BUG();
208 }
209
210 static int fuse_inode_eq(struct inode *inode, void *_nodeidp)
211 {
212 u64 nodeid = *(u64 *) _nodeidp;
213 if (get_node_id(inode) == nodeid)
214 return 1;
215 else
216 return 0;
217 }
218
219 static int fuse_inode_set(struct inode *inode, void *_nodeidp)
220 {
221 u64 nodeid = *(u64 *) _nodeidp;
222 get_fuse_inode(inode)->nodeid = nodeid;
223 return 0;
224 }
225
226 struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
227 int generation, struct fuse_attr *attr,
228 u64 attr_valid, u64 attr_version)
229 {
230 struct inode *inode;
231 struct fuse_inode *fi;
232 struct fuse_conn *fc = get_fuse_conn_super(sb);
233
234 retry:
235 inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid);
236 if (!inode)
237 return NULL;
238
239 if ((inode->i_state & I_NEW)) {
240 inode->i_flags |= S_NOATIME|S_NOCMTIME;
241 inode->i_generation = generation;
242 inode->i_data.backing_dev_info = &fc->bdi;
243 fuse_init_inode(inode, attr);
244 unlock_new_inode(inode);
245 } else if ((inode->i_mode ^ attr->mode) & S_IFMT) {
246 /* Inode has changed type, any I/O on the old should fail */
247 make_bad_inode(inode);
248 iput(inode);
249 goto retry;
250 }
251
252 fi = get_fuse_inode(inode);
253 spin_lock(&fc->lock);
254 fi->nlookup++;
255 spin_unlock(&fc->lock);
256 fuse_change_attributes(inode, attr, attr_valid, attr_version);
257
258 return inode;
259 }
260
261 static void fuse_umount_begin(struct super_block *sb)
262 {
263 lock_kernel();
264 fuse_abort_conn(get_fuse_conn_super(sb));
265 unlock_kernel();
266 }
267
268 static void fuse_send_destroy(struct fuse_conn *fc)
269 {
270 struct fuse_req *req = fc->destroy_req;
271 if (req && fc->conn_init) {
272 fc->destroy_req = NULL;
273 req->in.h.opcode = FUSE_DESTROY;
274 req->force = 1;
275 fuse_request_send(fc, req);
276 fuse_put_request(fc, req);
277 }
278 }
279
280 static void fuse_put_super(struct super_block *sb)
281 {
282 struct fuse_conn *fc = get_fuse_conn_super(sb);
283
284 fuse_send_destroy(fc);
285 spin_lock(&fc->lock);
286 fc->connected = 0;
287 fc->blocked = 0;
288 spin_unlock(&fc->lock);
289 /* Flush all readers on this fs */
290 kill_fasync(&fc->fasync, SIGIO, POLL_IN);
291 wake_up_all(&fc->waitq);
292 wake_up_all(&fc->blocked_waitq);
293 wake_up_all(&fc->reserved_req_waitq);
294 mutex_lock(&fuse_mutex);
295 list_del(&fc->entry);
296 fuse_ctl_remove_conn(fc);
297 mutex_unlock(&fuse_mutex);
298 bdi_destroy(&fc->bdi);
299 fuse_conn_put(fc);
300 }
301
302 static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
303 {
304 stbuf->f_type = FUSE_SUPER_MAGIC;
305 stbuf->f_bsize = attr->bsize;
306 stbuf->f_frsize = attr->frsize;
307 stbuf->f_blocks = attr->blocks;
308 stbuf->f_bfree = attr->bfree;
309 stbuf->f_bavail = attr->bavail;
310 stbuf->f_files = attr->files;
311 stbuf->f_ffree = attr->ffree;
312 stbuf->f_namelen = attr->namelen;
313 /* fsid is left zero */
314 }
315
316 static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf)
317 {
318 struct super_block *sb = dentry->d_sb;
319 struct fuse_conn *fc = get_fuse_conn_super(sb);
320 struct fuse_req *req;
321 struct fuse_statfs_out outarg;
322 int err;
323
324 if (!fuse_allow_task(fc, current)) {
325 buf->f_type = FUSE_SUPER_MAGIC;
326 return 0;
327 }
328
329 req = fuse_get_req(fc);
330 if (IS_ERR(req))
331 return PTR_ERR(req);
332
333 memset(&outarg, 0, sizeof(outarg));
334 req->in.numargs = 0;
335 req->in.h.opcode = FUSE_STATFS;
336 req->in.h.nodeid = get_node_id(dentry->d_inode);
337 req->out.numargs = 1;
338 req->out.args[0].size =
339 fc->minor < 4 ? FUSE_COMPAT_STATFS_SIZE : sizeof(outarg);
340 req->out.args[0].value = &outarg;
341 fuse_request_send(fc, req);
342 err = req->out.h.error;
343 if (!err)
344 convert_fuse_statfs(buf, &outarg.st);
345 fuse_put_request(fc, req);
346 return err;
347 }
348
349 enum {
350 OPT_FD,
351 OPT_ROOTMODE,
352 OPT_USER_ID,
353 OPT_GROUP_ID,
354 OPT_DEFAULT_PERMISSIONS,
355 OPT_ALLOW_OTHER,
356 OPT_MAX_READ,
357 OPT_BLKSIZE,
358 OPT_ERR
359 };
360
361 static const match_table_t tokens = {
362 {OPT_FD, "fd=%u"},
363 {OPT_ROOTMODE, "rootmode=%o"},
364 {OPT_USER_ID, "user_id=%u"},
365 {OPT_GROUP_ID, "group_id=%u"},
366 {OPT_DEFAULT_PERMISSIONS, "default_permissions"},
367 {OPT_ALLOW_OTHER, "allow_other"},
368 {OPT_MAX_READ, "max_read=%u"},
369 {OPT_BLKSIZE, "blksize=%u"},
370 {OPT_ERR, NULL}
371 };
372
373 static int parse_fuse_opt(char *opt, struct fuse_mount_data *d, int is_bdev)
374 {
375 char *p;
376 memset(d, 0, sizeof(struct fuse_mount_data));
377 d->max_read = ~0;
378 d->blksize = FUSE_DEFAULT_BLKSIZE;
379
380 while ((p = strsep(&opt, ",")) != NULL) {
381 int token;
382 int value;
383 substring_t args[MAX_OPT_ARGS];
384 if (!*p)
385 continue;
386
387 token = match_token(p, tokens, args);
388 switch (token) {
389 case OPT_FD:
390 if (match_int(&args[0], &value))
391 return 0;
392 d->fd = value;
393 d->fd_present = 1;
394 break;
395
396 case OPT_ROOTMODE:
397 if (match_octal(&args[0], &value))
398 return 0;
399 if (!fuse_valid_type(value))
400 return 0;
401 d->rootmode = value;
402 d->rootmode_present = 1;
403 break;
404
405 case OPT_USER_ID:
406 if (match_int(&args[0], &value))
407 return 0;
408 d->user_id = value;
409 d->user_id_present = 1;
410 break;
411
412 case OPT_GROUP_ID:
413 if (match_int(&args[0], &value))
414 return 0;
415 d->group_id = value;
416 d->group_id_present = 1;
417 break;
418
419 case OPT_DEFAULT_PERMISSIONS:
420 d->flags |= FUSE_DEFAULT_PERMISSIONS;
421 break;
422
423 case OPT_ALLOW_OTHER:
424 d->flags |= FUSE_ALLOW_OTHER;
425 break;
426
427 case OPT_MAX_READ:
428 if (match_int(&args[0], &value))
429 return 0;
430 d->max_read = value;
431 break;
432
433 case OPT_BLKSIZE:
434 if (!is_bdev || match_int(&args[0], &value))
435 return 0;
436 d->blksize = value;
437 break;
438
439 default:
440 return 0;
441 }
442 }
443
444 if (!d->fd_present || !d->rootmode_present ||
445 !d->user_id_present || !d->group_id_present)
446 return 0;
447
448 return 1;
449 }
450
451 static int fuse_show_options(struct seq_file *m, struct vfsmount *mnt)
452 {
453 struct fuse_conn *fc = get_fuse_conn_super(mnt->mnt_sb);
454
455 seq_printf(m, ",user_id=%u", fc->user_id);
456 seq_printf(m, ",group_id=%u", fc->group_id);
457 if (fc->flags & FUSE_DEFAULT_PERMISSIONS)
458 seq_puts(m, ",default_permissions");
459 if (fc->flags & FUSE_ALLOW_OTHER)
460 seq_puts(m, ",allow_other");
461 if (fc->max_read != ~0)
462 seq_printf(m, ",max_read=%u", fc->max_read);
463 if (mnt->mnt_sb->s_bdev &&
464 mnt->mnt_sb->s_blocksize != FUSE_DEFAULT_BLKSIZE)
465 seq_printf(m, ",blksize=%lu", mnt->mnt_sb->s_blocksize);
466 return 0;
467 }
468
469 int fuse_conn_init(struct fuse_conn *fc, struct super_block *sb)
470 {
471 int err;
472
473 memset(fc, 0, sizeof(*fc));
474 spin_lock_init(&fc->lock);
475 mutex_init(&fc->inst_mutex);
476 atomic_set(&fc->count, 1);
477 init_waitqueue_head(&fc->waitq);
478 init_waitqueue_head(&fc->blocked_waitq);
479 init_waitqueue_head(&fc->reserved_req_waitq);
480 INIT_LIST_HEAD(&fc->pending);
481 INIT_LIST_HEAD(&fc->processing);
482 INIT_LIST_HEAD(&fc->io);
483 INIT_LIST_HEAD(&fc->interrupts);
484 INIT_LIST_HEAD(&fc->bg_queue);
485 INIT_LIST_HEAD(&fc->entry);
486 atomic_set(&fc->num_waiting, 0);
487 fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
488 fc->bdi.unplug_io_fn = default_unplug_io_fn;
489 /* fuse does it's own writeback accounting */
490 fc->bdi.capabilities = BDI_CAP_NO_ACCT_WB;
491 fc->khctr = 0;
492 fc->polled_files = RB_ROOT;
493 fc->dev = sb->s_dev;
494 err = bdi_init(&fc->bdi);
495 if (err)
496 goto error_mutex_destroy;
497 if (sb->s_bdev) {
498 err = bdi_register(&fc->bdi, NULL, "%u:%u-fuseblk",
499 MAJOR(fc->dev), MINOR(fc->dev));
500 } else {
501 err = bdi_register_dev(&fc->bdi, fc->dev);
502 }
503 if (err)
504 goto error_bdi_destroy;
505 /*
506 * For a single fuse filesystem use max 1% of dirty +
507 * writeback threshold.
508 *
509 * This gives about 1M of write buffer for memory maps on a
510 * machine with 1G and 10% dirty_ratio, which should be more
511 * than enough.
512 *
513 * Privileged users can raise it by writing to
514 *
515 * /sys/class/bdi/<bdi>/max_ratio
516 */
517 bdi_set_max_ratio(&fc->bdi, 1);
518 fc->reqctr = 0;
519 fc->blocked = 1;
520 fc->attr_version = 1;
521 get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key));
522
523 return 0;
524
525 error_bdi_destroy:
526 bdi_destroy(&fc->bdi);
527 error_mutex_destroy:
528 mutex_destroy(&fc->inst_mutex);
529 return err;
530 }
531 EXPORT_SYMBOL_GPL(fuse_conn_init);
532
533 void fuse_conn_put(struct fuse_conn *fc)
534 {
535 if (atomic_dec_and_test(&fc->count)) {
536 if (fc->destroy_req)
537 fuse_request_free(fc->destroy_req);
538 mutex_destroy(&fc->inst_mutex);
539 fc->release(fc);
540 }
541 }
542
543 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc)
544 {
545 atomic_inc(&fc->count);
546 return fc;
547 }
548
549 static struct inode *fuse_get_root_inode(struct super_block *sb, unsigned mode)
550 {
551 struct fuse_attr attr;
552 memset(&attr, 0, sizeof(attr));
553
554 attr.mode = mode;
555 attr.ino = FUSE_ROOT_ID;
556 attr.nlink = 1;
557 return fuse_iget(sb, 1, 0, &attr, 0, 0);
558 }
559
560 struct fuse_inode_handle {
561 u64 nodeid;
562 u32 generation;
563 };
564
565 static struct dentry *fuse_get_dentry(struct super_block *sb,
566 struct fuse_inode_handle *handle)
567 {
568 struct fuse_conn *fc = get_fuse_conn_super(sb);
569 struct inode *inode;
570 struct dentry *entry;
571 int err = -ESTALE;
572
573 if (handle->nodeid == 0)
574 goto out_err;
575
576 inode = ilookup5(sb, handle->nodeid, fuse_inode_eq, &handle->nodeid);
577 if (!inode) {
578 struct fuse_entry_out outarg;
579 struct qstr name;
580
581 if (!fc->export_support)
582 goto out_err;
583
584 name.len = 1;
585 name.name = ".";
586 err = fuse_lookup_name(sb, handle->nodeid, &name, &outarg,
587 &inode);
588 if (err && err != -ENOENT)
589 goto out_err;
590 if (err || !inode) {
591 err = -ESTALE;
592 goto out_err;
593 }
594 err = -EIO;
595 if (get_node_id(inode) != handle->nodeid)
596 goto out_iput;
597 }
598 err = -ESTALE;
599 if (inode->i_generation != handle->generation)
600 goto out_iput;
601
602 entry = d_obtain_alias(inode);
603 if (!IS_ERR(entry) && get_node_id(inode) != FUSE_ROOT_ID) {
604 entry->d_op = &fuse_dentry_operations;
605 fuse_invalidate_entry_cache(entry);
606 }
607
608 return entry;
609
610 out_iput:
611 iput(inode);
612 out_err:
613 return ERR_PTR(err);
614 }
615
616 static int fuse_encode_fh(struct dentry *dentry, u32 *fh, int *max_len,
617 int connectable)
618 {
619 struct inode *inode = dentry->d_inode;
620 bool encode_parent = connectable && !S_ISDIR(inode->i_mode);
621 int len = encode_parent ? 6 : 3;
622 u64 nodeid;
623 u32 generation;
624
625 if (*max_len < len)
626 return 255;
627
628 nodeid = get_fuse_inode(inode)->nodeid;
629 generation = inode->i_generation;
630
631 fh[0] = (u32)(nodeid >> 32);
632 fh[1] = (u32)(nodeid & 0xffffffff);
633 fh[2] = generation;
634
635 if (encode_parent) {
636 struct inode *parent;
637
638 spin_lock(&dentry->d_lock);
639 parent = dentry->d_parent->d_inode;
640 nodeid = get_fuse_inode(parent)->nodeid;
641 generation = parent->i_generation;
642 spin_unlock(&dentry->d_lock);
643
644 fh[3] = (u32)(nodeid >> 32);
645 fh[4] = (u32)(nodeid & 0xffffffff);
646 fh[5] = generation;
647 }
648
649 *max_len = len;
650 return encode_parent ? 0x82 : 0x81;
651 }
652
653 static struct dentry *fuse_fh_to_dentry(struct super_block *sb,
654 struct fid *fid, int fh_len, int fh_type)
655 {
656 struct fuse_inode_handle handle;
657
658 if ((fh_type != 0x81 && fh_type != 0x82) || fh_len < 3)
659 return NULL;
660
661 handle.nodeid = (u64) fid->raw[0] << 32;
662 handle.nodeid |= (u64) fid->raw[1];
663 handle.generation = fid->raw[2];
664 return fuse_get_dentry(sb, &handle);
665 }
666
667 static struct dentry *fuse_fh_to_parent(struct super_block *sb,
668 struct fid *fid, int fh_len, int fh_type)
669 {
670 struct fuse_inode_handle parent;
671
672 if (fh_type != 0x82 || fh_len < 6)
673 return NULL;
674
675 parent.nodeid = (u64) fid->raw[3] << 32;
676 parent.nodeid |= (u64) fid->raw[4];
677 parent.generation = fid->raw[5];
678 return fuse_get_dentry(sb, &parent);
679 }
680
681 static struct dentry *fuse_get_parent(struct dentry *child)
682 {
683 struct inode *child_inode = child->d_inode;
684 struct fuse_conn *fc = get_fuse_conn(child_inode);
685 struct inode *inode;
686 struct dentry *parent;
687 struct fuse_entry_out outarg;
688 struct qstr name;
689 int err;
690
691 if (!fc->export_support)
692 return ERR_PTR(-ESTALE);
693
694 name.len = 2;
695 name.name = "..";
696 err = fuse_lookup_name(child_inode->i_sb, get_node_id(child_inode),
697 &name, &outarg, &inode);
698 if (err) {
699 if (err == -ENOENT)
700 return ERR_PTR(-ESTALE);
701 return ERR_PTR(err);
702 }
703
704 parent = d_obtain_alias(inode);
705 if (!IS_ERR(parent) && get_node_id(inode) != FUSE_ROOT_ID) {
706 parent->d_op = &fuse_dentry_operations;
707 fuse_invalidate_entry_cache(parent);
708 }
709
710 return parent;
711 }
712
713 static const struct export_operations fuse_export_operations = {
714 .fh_to_dentry = fuse_fh_to_dentry,
715 .fh_to_parent = fuse_fh_to_parent,
716 .encode_fh = fuse_encode_fh,
717 .get_parent = fuse_get_parent,
718 };
719
720 static const struct super_operations fuse_super_operations = {
721 .alloc_inode = fuse_alloc_inode,
722 .destroy_inode = fuse_destroy_inode,
723 .clear_inode = fuse_clear_inode,
724 .drop_inode = generic_delete_inode,
725 .remount_fs = fuse_remount_fs,
726 .put_super = fuse_put_super,
727 .umount_begin = fuse_umount_begin,
728 .statfs = fuse_statfs,
729 .show_options = fuse_show_options,
730 };
731
732 static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
733 {
734 struct fuse_init_out *arg = &req->misc.init_out;
735
736 if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION)
737 fc->conn_error = 1;
738 else {
739 unsigned long ra_pages;
740
741 if (arg->minor >= 6) {
742 ra_pages = arg->max_readahead / PAGE_CACHE_SIZE;
743 if (arg->flags & FUSE_ASYNC_READ)
744 fc->async_read = 1;
745 if (!(arg->flags & FUSE_POSIX_LOCKS))
746 fc->no_lock = 1;
747 if (arg->flags & FUSE_ATOMIC_O_TRUNC)
748 fc->atomic_o_trunc = 1;
749 if (arg->minor >= 9) {
750 /* LOOKUP has dependency on proto version */
751 if (arg->flags & FUSE_EXPORT_SUPPORT)
752 fc->export_support = 1;
753 }
754 if (arg->flags & FUSE_BIG_WRITES)
755 fc->big_writes = 1;
756 } else {
757 ra_pages = fc->max_read / PAGE_CACHE_SIZE;
758 fc->no_lock = 1;
759 }
760
761 fc->bdi.ra_pages = min(fc->bdi.ra_pages, ra_pages);
762 fc->minor = arg->minor;
763 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
764 fc->max_write = max_t(unsigned, 4096, fc->max_write);
765 fc->conn_init = 1;
766 }
767 fc->blocked = 0;
768 wake_up_all(&fc->blocked_waitq);
769 }
770
771 static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req)
772 {
773 struct fuse_init_in *arg = &req->misc.init_in;
774
775 arg->major = FUSE_KERNEL_VERSION;
776 arg->minor = FUSE_KERNEL_MINOR_VERSION;
777 arg->max_readahead = fc->bdi.ra_pages * PAGE_CACHE_SIZE;
778 arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_ATOMIC_O_TRUNC |
779 FUSE_EXPORT_SUPPORT | FUSE_BIG_WRITES;
780 req->in.h.opcode = FUSE_INIT;
781 req->in.numargs = 1;
782 req->in.args[0].size = sizeof(*arg);
783 req->in.args[0].value = arg;
784 req->out.numargs = 1;
785 /* Variable length arguement used for backward compatibility
786 with interface version < 7.5. Rest of init_out is zeroed
787 by do_get_request(), so a short reply is not a problem */
788 req->out.argvar = 1;
789 req->out.args[0].size = sizeof(struct fuse_init_out);
790 req->out.args[0].value = &req->misc.init_out;
791 req->end = process_init_reply;
792 fuse_request_send_background(fc, req);
793 }
794
795 static void fuse_free_conn(struct fuse_conn *fc)
796 {
797 kfree(fc);
798 }
799
800 static int fuse_fill_super(struct super_block *sb, void *data, int silent)
801 {
802 struct fuse_conn *fc;
803 struct inode *root;
804 struct fuse_mount_data d;
805 struct file *file;
806 struct dentry *root_dentry;
807 struct fuse_req *init_req;
808 int err;
809 int is_bdev = sb->s_bdev != NULL;
810
811 err = -EINVAL;
812 if (sb->s_flags & MS_MANDLOCK)
813 goto err;
814
815 if (!parse_fuse_opt((char *) data, &d, is_bdev))
816 goto err;
817
818 if (is_bdev) {
819 #ifdef CONFIG_BLOCK
820 err = -EINVAL;
821 if (!sb_set_blocksize(sb, d.blksize))
822 goto err;
823 #endif
824 } else {
825 sb->s_blocksize = PAGE_CACHE_SIZE;
826 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
827 }
828 sb->s_magic = FUSE_SUPER_MAGIC;
829 sb->s_op = &fuse_super_operations;
830 sb->s_maxbytes = MAX_LFS_FILESIZE;
831 sb->s_export_op = &fuse_export_operations;
832
833 file = fget(d.fd);
834 err = -EINVAL;
835 if (!file)
836 goto err;
837
838 if (file->f_op != &fuse_dev_operations)
839 goto err_fput;
840
841 fc = kmalloc(sizeof(*fc), GFP_KERNEL);
842 err = -ENOMEM;
843 if (!fc)
844 goto err_fput;
845
846 err = fuse_conn_init(fc, sb);
847 if (err) {
848 kfree(fc);
849 goto err_fput;
850 }
851
852 fc->release = fuse_free_conn;
853 fc->flags = d.flags;
854 fc->user_id = d.user_id;
855 fc->group_id = d.group_id;
856 fc->max_read = max_t(unsigned, 4096, d.max_read);
857
858 /* Used by get_root_inode() */
859 sb->s_fs_info = fc;
860
861 err = -ENOMEM;
862 root = fuse_get_root_inode(sb, d.rootmode);
863 if (!root)
864 goto err_put_conn;
865
866 root_dentry = d_alloc_root(root);
867 if (!root_dentry) {
868 iput(root);
869 goto err_put_conn;
870 }
871
872 init_req = fuse_request_alloc();
873 if (!init_req)
874 goto err_put_root;
875
876 if (is_bdev) {
877 fc->destroy_req = fuse_request_alloc();
878 if (!fc->destroy_req)
879 goto err_free_init_req;
880 }
881
882 mutex_lock(&fuse_mutex);
883 err = -EINVAL;
884 if (file->private_data)
885 goto err_unlock;
886
887 err = fuse_ctl_add_conn(fc);
888 if (err)
889 goto err_unlock;
890
891 list_add_tail(&fc->entry, &fuse_conn_list);
892 sb->s_root = root_dentry;
893 fc->connected = 1;
894 file->private_data = fuse_conn_get(fc);
895 mutex_unlock(&fuse_mutex);
896 /*
897 * atomic_dec_and_test() in fput() provides the necessary
898 * memory barrier for file->private_data to be visible on all
899 * CPUs after this
900 */
901 fput(file);
902
903 fuse_send_init(fc, init_req);
904
905 return 0;
906
907 err_unlock:
908 mutex_unlock(&fuse_mutex);
909 err_free_init_req:
910 fuse_request_free(init_req);
911 err_put_root:
912 dput(root_dentry);
913 err_put_conn:
914 bdi_destroy(&fc->bdi);
915 fuse_conn_put(fc);
916 err_fput:
917 fput(file);
918 err:
919 return err;
920 }
921
922 static int fuse_get_sb(struct file_system_type *fs_type,
923 int flags, const char *dev_name,
924 void *raw_data, struct vfsmount *mnt)
925 {
926 return get_sb_nodev(fs_type, flags, raw_data, fuse_fill_super, mnt);
927 }
928
929 static struct file_system_type fuse_fs_type = {
930 .owner = THIS_MODULE,
931 .name = "fuse",
932 .fs_flags = FS_HAS_SUBTYPE,
933 .get_sb = fuse_get_sb,
934 .kill_sb = kill_anon_super,
935 };
936
937 #ifdef CONFIG_BLOCK
938 static int fuse_get_sb_blk(struct file_system_type *fs_type,
939 int flags, const char *dev_name,
940 void *raw_data, struct vfsmount *mnt)
941 {
942 return get_sb_bdev(fs_type, flags, dev_name, raw_data, fuse_fill_super,
943 mnt);
944 }
945
946 static struct file_system_type fuseblk_fs_type = {
947 .owner = THIS_MODULE,
948 .name = "fuseblk",
949 .get_sb = fuse_get_sb_blk,
950 .kill_sb = kill_block_super,
951 .fs_flags = FS_REQUIRES_DEV | FS_HAS_SUBTYPE,
952 };
953
954 static inline int register_fuseblk(void)
955 {
956 return register_filesystem(&fuseblk_fs_type);
957 }
958
959 static inline void unregister_fuseblk(void)
960 {
961 unregister_filesystem(&fuseblk_fs_type);
962 }
963 #else
964 static inline int register_fuseblk(void)
965 {
966 return 0;
967 }
968
969 static inline void unregister_fuseblk(void)
970 {
971 }
972 #endif
973
974 static void fuse_inode_init_once(void *foo)
975 {
976 struct inode *inode = foo;
977
978 inode_init_once(inode);
979 }
980
981 static int __init fuse_fs_init(void)
982 {
983 int err;
984
985 err = register_filesystem(&fuse_fs_type);
986 if (err)
987 goto out;
988
989 err = register_fuseblk();
990 if (err)
991 goto out_unreg;
992
993 fuse_inode_cachep = kmem_cache_create("fuse_inode",
994 sizeof(struct fuse_inode),
995 0, SLAB_HWCACHE_ALIGN,
996 fuse_inode_init_once);
997 err = -ENOMEM;
998 if (!fuse_inode_cachep)
999 goto out_unreg2;
1000
1001 return 0;
1002
1003 out_unreg2:
1004 unregister_fuseblk();
1005 out_unreg:
1006 unregister_filesystem(&fuse_fs_type);
1007 out:
1008 return err;
1009 }
1010
1011 static void fuse_fs_cleanup(void)
1012 {
1013 unregister_filesystem(&fuse_fs_type);
1014 unregister_fuseblk();
1015 kmem_cache_destroy(fuse_inode_cachep);
1016 }
1017
1018 static struct kobject *fuse_kobj;
1019 static struct kobject *connections_kobj;
1020
1021 static int fuse_sysfs_init(void)
1022 {
1023 int err;
1024
1025 fuse_kobj = kobject_create_and_add("fuse", fs_kobj);
1026 if (!fuse_kobj) {
1027 err = -ENOMEM;
1028 goto out_err;
1029 }
1030
1031 connections_kobj = kobject_create_and_add("connections", fuse_kobj);
1032 if (!connections_kobj) {
1033 err = -ENOMEM;
1034 goto out_fuse_unregister;
1035 }
1036
1037 return 0;
1038
1039 out_fuse_unregister:
1040 kobject_put(fuse_kobj);
1041 out_err:
1042 return err;
1043 }
1044
1045 static void fuse_sysfs_cleanup(void)
1046 {
1047 kobject_put(connections_kobj);
1048 kobject_put(fuse_kobj);
1049 }
1050
1051 static int __init fuse_init(void)
1052 {
1053 int res;
1054
1055 printk(KERN_INFO "fuse init (API version %i.%i)\n",
1056 FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
1057
1058 INIT_LIST_HEAD(&fuse_conn_list);
1059 res = fuse_fs_init();
1060 if (res)
1061 goto err;
1062
1063 res = fuse_dev_init();
1064 if (res)
1065 goto err_fs_cleanup;
1066
1067 res = fuse_sysfs_init();
1068 if (res)
1069 goto err_dev_cleanup;
1070
1071 res = fuse_ctl_init();
1072 if (res)
1073 goto err_sysfs_cleanup;
1074
1075 return 0;
1076
1077 err_sysfs_cleanup:
1078 fuse_sysfs_cleanup();
1079 err_dev_cleanup:
1080 fuse_dev_cleanup();
1081 err_fs_cleanup:
1082 fuse_fs_cleanup();
1083 err:
1084 return res;
1085 }
1086
1087 static void __exit fuse_exit(void)
1088 {
1089 printk(KERN_DEBUG "fuse exit\n");
1090
1091 fuse_ctl_cleanup();
1092 fuse_sysfs_cleanup();
1093 fuse_fs_cleanup();
1094 fuse_dev_cleanup();
1095 }
1096
1097 module_init(fuse_init);
1098 module_exit(fuse_exit);
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