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[tomato.git] / release / src-rt-6.x.4708 / linux / linux-2.6.36 / fs / fuse / inode.c
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1 /*
2 FUSE: Filesystem in Userspace
3 Copyright (C) 2001-2008 Miklos Szeredi <miklos@szeredi.hu>
5 This program can be distributed under the terms of the GNU GPL.
6 See the file COPYING.
7 */
9 #include "fuse_i.h"
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/moduleparam.h>
18 #include <linux/parser.h>
19 #include <linux/statfs.h>
20 #include <linux/random.h>
21 #include <linux/sched.h>
22 #include <linux/exportfs.h>
24 MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>");
25 MODULE_DESCRIPTION("Filesystem in Userspace");
26 MODULE_LICENSE("GPL");
28 static struct kmem_cache *fuse_inode_cachep;
29 struct list_head fuse_conn_list;
30 DEFINE_MUTEX(fuse_mutex);
32 static int set_global_limit(const char *val, struct kernel_param *kp);
34 unsigned max_user_bgreq;
35 module_param_call(max_user_bgreq, set_global_limit, param_get_uint,
36 &max_user_bgreq, 0644);
37 __MODULE_PARM_TYPE(max_user_bgreq, "uint");
38 MODULE_PARM_DESC(max_user_bgreq,
39 "Global limit for the maximum number of backgrounded requests an "
40 "unprivileged user can set");
42 unsigned max_user_congthresh;
43 module_param_call(max_user_congthresh, set_global_limit, param_get_uint,
44 &max_user_congthresh, 0644);
45 __MODULE_PARM_TYPE(max_user_congthresh, "uint");
46 MODULE_PARM_DESC(max_user_congthresh,
47 "Global limit for the maximum congestion threshold an "
48 "unprivileged user can set");
50 #define FUSE_SUPER_MAGIC 0x65735546
52 #define FUSE_DEFAULT_BLKSIZE 512
54 /** Maximum number of outstanding background requests */
55 #define FUSE_DEFAULT_MAX_BACKGROUND 12
57 /** Congestion starts at 75% of maximum */
58 #define FUSE_DEFAULT_CONGESTION_THRESHOLD (FUSE_DEFAULT_MAX_BACKGROUND * 3 / 4)
60 struct fuse_mount_data {
61 int fd;
62 unsigned rootmode;
63 unsigned user_id;
64 unsigned group_id;
65 unsigned fd_present:1;
66 unsigned rootmode_present:1;
67 unsigned user_id_present:1;
68 unsigned group_id_present:1;
69 unsigned flags;
70 unsigned max_read;
71 unsigned blksize;
74 static struct inode *fuse_alloc_inode(struct super_block *sb)
76 struct inode *inode;
77 struct fuse_inode *fi;
79 inode = kmem_cache_alloc(fuse_inode_cachep, GFP_KERNEL);
80 if (!inode)
81 return NULL;
83 fi = get_fuse_inode(inode);
84 fi->i_time = 0;
85 fi->nodeid = 0;
86 fi->nlookup = 0;
87 fi->attr_version = 0;
88 fi->writectr = 0;
89 INIT_LIST_HEAD(&fi->write_files);
90 INIT_LIST_HEAD(&fi->queued_writes);
91 INIT_LIST_HEAD(&fi->writepages);
92 init_waitqueue_head(&fi->page_waitq);
93 fi->forget_req = fuse_request_alloc();
94 if (!fi->forget_req) {
95 kmem_cache_free(fuse_inode_cachep, inode);
96 return NULL;
99 return inode;
102 static void fuse_destroy_inode(struct inode *inode)
104 struct fuse_inode *fi = get_fuse_inode(inode);
105 BUG_ON(!list_empty(&fi->write_files));
106 BUG_ON(!list_empty(&fi->queued_writes));
107 if (fi->forget_req)
108 fuse_request_free(fi->forget_req);
109 kmem_cache_free(fuse_inode_cachep, inode);
112 void fuse_send_forget(struct fuse_conn *fc, struct fuse_req *req,
113 u64 nodeid, u64 nlookup)
115 struct fuse_forget_in *inarg = &req->misc.forget_in;
116 inarg->nlookup = nlookup;
117 req->in.h.opcode = FUSE_FORGET;
118 req->in.h.nodeid = nodeid;
119 req->in.numargs = 1;
120 req->in.args[0].size = sizeof(struct fuse_forget_in);
121 req->in.args[0].value = inarg;
122 fuse_request_send_noreply(fc, req);
125 static void fuse_evict_inode(struct inode *inode)
127 truncate_inode_pages(&inode->i_data, 0);
128 end_writeback(inode);
129 if (inode->i_sb->s_flags & MS_ACTIVE) {
130 struct fuse_conn *fc = get_fuse_conn(inode);
131 struct fuse_inode *fi = get_fuse_inode(inode);
132 fuse_send_forget(fc, fi->forget_req, fi->nodeid, fi->nlookup);
133 fi->forget_req = NULL;
137 static int fuse_remount_fs(struct super_block *sb, int *flags, char *data)
139 if (*flags & MS_MANDLOCK)
140 return -EINVAL;
142 return 0;
145 void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
146 u64 attr_valid)
148 struct fuse_conn *fc = get_fuse_conn(inode);
149 struct fuse_inode *fi = get_fuse_inode(inode);
151 fi->attr_version = ++fc->attr_version;
152 fi->i_time = attr_valid;
154 inode->i_ino = attr->ino;
155 inode->i_mode = (inode->i_mode & S_IFMT) | (attr->mode & 07777);
156 inode->i_nlink = attr->nlink;
157 inode->i_uid = attr->uid;
158 inode->i_gid = attr->gid;
159 inode->i_blocks = attr->blocks;
160 inode->i_atime.tv_sec = attr->atime;
161 inode->i_atime.tv_nsec = attr->atimensec;
162 inode->i_mtime.tv_sec = attr->mtime;
163 inode->i_mtime.tv_nsec = attr->mtimensec;
164 inode->i_ctime.tv_sec = attr->ctime;
165 inode->i_ctime.tv_nsec = attr->ctimensec;
167 if (attr->blksize != 0)
168 inode->i_blkbits = ilog2(attr->blksize);
169 else
170 inode->i_blkbits = inode->i_sb->s_blocksize_bits;
173 * Don't set the sticky bit in i_mode, unless we want the VFS
174 * to check permissions. This prevents failures due to the
175 * check in may_delete().
177 fi->orig_i_mode = inode->i_mode;
178 if (!(fc->flags & FUSE_DEFAULT_PERMISSIONS))
179 inode->i_mode &= ~S_ISVTX;
182 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
183 u64 attr_valid, u64 attr_version)
185 struct fuse_conn *fc = get_fuse_conn(inode);
186 struct fuse_inode *fi = get_fuse_inode(inode);
187 loff_t oldsize;
189 spin_lock(&fc->lock);
190 if (attr_version != 0 && fi->attr_version > attr_version) {
191 spin_unlock(&fc->lock);
192 return;
195 fuse_change_attributes_common(inode, attr, attr_valid);
197 oldsize = inode->i_size;
198 i_size_write(inode, attr->size);
199 spin_unlock(&fc->lock);
201 if (S_ISREG(inode->i_mode) && oldsize != attr->size) {
202 truncate_pagecache(inode, oldsize, attr->size);
203 invalidate_inode_pages2(inode->i_mapping);
207 static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
209 inode->i_mode = attr->mode & S_IFMT;
210 inode->i_size = attr->size;
211 if (S_ISREG(inode->i_mode)) {
212 fuse_init_common(inode);
213 fuse_init_file_inode(inode);
214 } else if (S_ISDIR(inode->i_mode))
215 fuse_init_dir(inode);
216 else if (S_ISLNK(inode->i_mode))
217 fuse_init_symlink(inode);
218 else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
219 S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
220 fuse_init_common(inode);
221 init_special_inode(inode, inode->i_mode,
222 new_decode_dev(attr->rdev));
223 } else
224 BUG();
227 int fuse_inode_eq(struct inode *inode, void *_nodeidp)
229 u64 nodeid = *(u64 *) _nodeidp;
230 if (get_node_id(inode) == nodeid)
231 return 1;
232 else
233 return 0;
236 static int fuse_inode_set(struct inode *inode, void *_nodeidp)
238 u64 nodeid = *(u64 *) _nodeidp;
239 get_fuse_inode(inode)->nodeid = nodeid;
240 return 0;
243 struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
244 int generation, struct fuse_attr *attr,
245 u64 attr_valid, u64 attr_version)
247 struct inode *inode;
248 struct fuse_inode *fi;
249 struct fuse_conn *fc = get_fuse_conn_super(sb);
251 retry:
252 inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid);
253 if (!inode)
254 return NULL;
256 if ((inode->i_state & I_NEW)) {
257 inode->i_flags |= S_NOATIME|S_NOCMTIME;
258 inode->i_generation = generation;
259 inode->i_data.backing_dev_info = &fc->bdi;
260 fuse_init_inode(inode, attr);
261 unlock_new_inode(inode);
262 } else if ((inode->i_mode ^ attr->mode) & S_IFMT) {
263 /* Inode has changed type, any I/O on the old should fail */
264 make_bad_inode(inode);
265 iput(inode);
266 goto retry;
269 fi = get_fuse_inode(inode);
270 spin_lock(&fc->lock);
271 fi->nlookup++;
272 spin_unlock(&fc->lock);
273 fuse_change_attributes(inode, attr, attr_valid, attr_version);
275 return inode;
278 int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid,
279 loff_t offset, loff_t len)
281 struct inode *inode;
282 pgoff_t pg_start;
283 pgoff_t pg_end;
285 inode = ilookup5(sb, nodeid, fuse_inode_eq, &nodeid);
286 if (!inode)
287 return -ENOENT;
289 fuse_invalidate_attr(inode);
290 if (offset >= 0) {
291 pg_start = offset >> PAGE_CACHE_SHIFT;
292 if (len <= 0)
293 pg_end = -1;
294 else
295 pg_end = (offset + len - 1) >> PAGE_CACHE_SHIFT;
296 invalidate_inode_pages2_range(inode->i_mapping,
297 pg_start, pg_end);
299 iput(inode);
300 return 0;
303 static void fuse_umount_begin(struct super_block *sb)
305 fuse_abort_conn(get_fuse_conn_super(sb));
308 static void fuse_send_destroy(struct fuse_conn *fc)
310 struct fuse_req *req = fc->destroy_req;
311 if (req && fc->conn_init) {
312 fc->destroy_req = NULL;
313 req->in.h.opcode = FUSE_DESTROY;
314 req->force = 1;
315 fuse_request_send(fc, req);
316 fuse_put_request(fc, req);
320 static void fuse_bdi_destroy(struct fuse_conn *fc)
322 if (fc->bdi_initialized)
323 bdi_destroy(&fc->bdi);
326 void fuse_conn_kill(struct fuse_conn *fc)
328 spin_lock(&fc->lock);
329 fc->connected = 0;
330 fc->blocked = 0;
331 spin_unlock(&fc->lock);
332 /* Flush all readers on this fs */
333 kill_fasync(&fc->fasync, SIGIO, POLL_IN);
334 wake_up_all(&fc->waitq);
335 wake_up_all(&fc->blocked_waitq);
336 wake_up_all(&fc->reserved_req_waitq);
337 mutex_lock(&fuse_mutex);
338 list_del(&fc->entry);
339 fuse_ctl_remove_conn(fc);
340 mutex_unlock(&fuse_mutex);
341 fuse_bdi_destroy(fc);
343 EXPORT_SYMBOL_GPL(fuse_conn_kill);
345 static void fuse_put_super(struct super_block *sb)
347 struct fuse_conn *fc = get_fuse_conn_super(sb);
349 fuse_send_destroy(fc);
350 fuse_conn_kill(fc);
351 fuse_conn_put(fc);
354 static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
356 stbuf->f_type = FUSE_SUPER_MAGIC;
357 stbuf->f_bsize = attr->bsize;
358 stbuf->f_frsize = attr->frsize;
359 stbuf->f_blocks = attr->blocks;
360 stbuf->f_bfree = attr->bfree;
361 stbuf->f_bavail = attr->bavail;
362 stbuf->f_files = attr->files;
363 stbuf->f_ffree = attr->ffree;
364 stbuf->f_namelen = attr->namelen;
365 /* fsid is left zero */
368 static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf)
370 struct super_block *sb = dentry->d_sb;
371 struct fuse_conn *fc = get_fuse_conn_super(sb);
372 struct fuse_req *req;
373 struct fuse_statfs_out outarg;
374 int err;
376 if (!fuse_allow_task(fc, current)) {
377 buf->f_type = FUSE_SUPER_MAGIC;
378 return 0;
381 req = fuse_get_req(fc);
382 if (IS_ERR(req))
383 return PTR_ERR(req);
385 memset(&outarg, 0, sizeof(outarg));
386 req->in.numargs = 0;
387 req->in.h.opcode = FUSE_STATFS;
388 req->in.h.nodeid = get_node_id(dentry->d_inode);
389 req->out.numargs = 1;
390 req->out.args[0].size =
391 fc->minor < 4 ? FUSE_COMPAT_STATFS_SIZE : sizeof(outarg);
392 req->out.args[0].value = &outarg;
393 fuse_request_send(fc, req);
394 err = req->out.h.error;
395 if (!err)
396 convert_fuse_statfs(buf, &outarg.st);
397 fuse_put_request(fc, req);
398 return err;
401 enum {
402 OPT_FD,
403 OPT_ROOTMODE,
404 OPT_USER_ID,
405 OPT_GROUP_ID,
406 OPT_DEFAULT_PERMISSIONS,
407 OPT_ALLOW_OTHER,
408 OPT_MAX_READ,
409 OPT_BLKSIZE,
410 OPT_ERR
413 static const match_table_t tokens = {
414 {OPT_FD, "fd=%u"},
415 {OPT_ROOTMODE, "rootmode=%o"},
416 {OPT_USER_ID, "user_id=%u"},
417 {OPT_GROUP_ID, "group_id=%u"},
418 {OPT_DEFAULT_PERMISSIONS, "default_permissions"},
419 {OPT_ALLOW_OTHER, "allow_other"},
420 {OPT_MAX_READ, "max_read=%u"},
421 {OPT_BLKSIZE, "blksize=%u"},
422 {OPT_ERR, NULL}
425 static int parse_fuse_opt(char *opt, struct fuse_mount_data *d, int is_bdev)
427 char *p;
428 memset(d, 0, sizeof(struct fuse_mount_data));
429 d->max_read = ~0;
430 d->blksize = FUSE_DEFAULT_BLKSIZE;
432 while ((p = strsep(&opt, ",")) != NULL) {
433 int token;
434 int value;
435 substring_t args[MAX_OPT_ARGS];
436 if (!*p)
437 continue;
439 token = match_token(p, tokens, args);
440 switch (token) {
441 case OPT_FD:
442 if (match_int(&args[0], &value))
443 return 0;
444 d->fd = value;
445 d->fd_present = 1;
446 break;
448 case OPT_ROOTMODE:
449 if (match_octal(&args[0], &value))
450 return 0;
451 if (!fuse_valid_type(value))
452 return 0;
453 d->rootmode = value;
454 d->rootmode_present = 1;
455 break;
457 case OPT_USER_ID:
458 if (match_int(&args[0], &value))
459 return 0;
460 d->user_id = value;
461 d->user_id_present = 1;
462 break;
464 case OPT_GROUP_ID:
465 if (match_int(&args[0], &value))
466 return 0;
467 d->group_id = value;
468 d->group_id_present = 1;
469 break;
471 case OPT_DEFAULT_PERMISSIONS:
472 d->flags |= FUSE_DEFAULT_PERMISSIONS;
473 break;
475 case OPT_ALLOW_OTHER:
476 d->flags |= FUSE_ALLOW_OTHER;
477 break;
479 case OPT_MAX_READ:
480 if (match_int(&args[0], &value))
481 return 0;
482 d->max_read = value;
483 break;
485 case OPT_BLKSIZE:
486 if (!is_bdev || match_int(&args[0], &value))
487 return 0;
488 d->blksize = value;
489 break;
491 default:
492 return 0;
496 if (!d->fd_present || !d->rootmode_present ||
497 !d->user_id_present || !d->group_id_present)
498 return 0;
500 return 1;
503 static int fuse_show_options(struct seq_file *m, struct vfsmount *mnt)
505 struct fuse_conn *fc = get_fuse_conn_super(mnt->mnt_sb);
507 seq_printf(m, ",user_id=%u", fc->user_id);
508 seq_printf(m, ",group_id=%u", fc->group_id);
509 if (fc->flags & FUSE_DEFAULT_PERMISSIONS)
510 seq_puts(m, ",default_permissions");
511 if (fc->flags & FUSE_ALLOW_OTHER)
512 seq_puts(m, ",allow_other");
513 if (fc->max_read != ~0)
514 seq_printf(m, ",max_read=%u", fc->max_read);
515 if (mnt->mnt_sb->s_bdev &&
516 mnt->mnt_sb->s_blocksize != FUSE_DEFAULT_BLKSIZE)
517 seq_printf(m, ",blksize=%lu", mnt->mnt_sb->s_blocksize);
518 return 0;
521 void fuse_conn_init(struct fuse_conn *fc)
523 memset(fc, 0, sizeof(*fc));
524 spin_lock_init(&fc->lock);
525 mutex_init(&fc->inst_mutex);
526 init_rwsem(&fc->killsb);
527 atomic_set(&fc->count, 1);
528 init_waitqueue_head(&fc->waitq);
529 init_waitqueue_head(&fc->blocked_waitq);
530 init_waitqueue_head(&fc->reserved_req_waitq);
531 INIT_LIST_HEAD(&fc->pending);
532 INIT_LIST_HEAD(&fc->processing);
533 INIT_LIST_HEAD(&fc->io);
534 INIT_LIST_HEAD(&fc->interrupts);
535 INIT_LIST_HEAD(&fc->bg_queue);
536 INIT_LIST_HEAD(&fc->entry);
537 atomic_set(&fc->num_waiting, 0);
538 fc->max_background = FUSE_DEFAULT_MAX_BACKGROUND;
539 fc->congestion_threshold = FUSE_DEFAULT_CONGESTION_THRESHOLD;
540 fc->khctr = 0;
541 fc->polled_files = RB_ROOT;
542 fc->reqctr = 0;
543 fc->blocked = 1;
544 fc->attr_version = 1;
545 get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key));
547 EXPORT_SYMBOL_GPL(fuse_conn_init);
549 void fuse_conn_put(struct fuse_conn *fc)
551 if (atomic_dec_and_test(&fc->count)) {
552 if (fc->destroy_req)
553 fuse_request_free(fc->destroy_req);
554 mutex_destroy(&fc->inst_mutex);
555 fc->release(fc);
558 EXPORT_SYMBOL_GPL(fuse_conn_put);
560 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc)
562 atomic_inc(&fc->count);
563 return fc;
565 EXPORT_SYMBOL_GPL(fuse_conn_get);
567 static struct inode *fuse_get_root_inode(struct super_block *sb, unsigned mode)
569 struct fuse_attr attr;
570 memset(&attr, 0, sizeof(attr));
572 attr.mode = mode;
573 attr.ino = FUSE_ROOT_ID;
574 attr.nlink = 1;
575 return fuse_iget(sb, 1, 0, &attr, 0, 0);
578 struct fuse_inode_handle {
579 u64 nodeid;
580 u32 generation;
583 static struct dentry *fuse_get_dentry(struct super_block *sb,
584 struct fuse_inode_handle *handle)
586 struct fuse_conn *fc = get_fuse_conn_super(sb);
587 struct inode *inode;
588 struct dentry *entry;
589 int err = -ESTALE;
591 if (handle->nodeid == 0)
592 goto out_err;
594 inode = ilookup5(sb, handle->nodeid, fuse_inode_eq, &handle->nodeid);
595 if (!inode) {
596 struct fuse_entry_out outarg;
597 struct qstr name;
599 if (!fc->export_support)
600 goto out_err;
602 name.len = 1;
603 name.name = ".";
604 err = fuse_lookup_name(sb, handle->nodeid, &name, &outarg,
605 &inode);
606 if (err && err != -ENOENT)
607 goto out_err;
608 if (err || !inode) {
609 err = -ESTALE;
610 goto out_err;
612 err = -EIO;
613 if (get_node_id(inode) != handle->nodeid)
614 goto out_iput;
616 err = -ESTALE;
617 if (inode->i_generation != handle->generation)
618 goto out_iput;
620 entry = d_obtain_alias(inode);
621 if (!IS_ERR(entry) && get_node_id(inode) != FUSE_ROOT_ID) {
622 entry->d_op = &fuse_dentry_operations;
623 fuse_invalidate_entry_cache(entry);
626 return entry;
628 out_iput:
629 iput(inode);
630 out_err:
631 return ERR_PTR(err);
634 static int fuse_encode_fh(struct dentry *dentry, u32 *fh, int *max_len,
635 int connectable)
637 struct inode *inode = dentry->d_inode;
638 bool encode_parent = connectable && !S_ISDIR(inode->i_mode);
639 int len = encode_parent ? 6 : 3;
640 u64 nodeid;
641 u32 generation;
643 if (*max_len < len)
644 return 255;
646 nodeid = get_fuse_inode(inode)->nodeid;
647 generation = inode->i_generation;
649 fh[0] = (u32)(nodeid >> 32);
650 fh[1] = (u32)(nodeid & 0xffffffff);
651 fh[2] = generation;
653 if (encode_parent) {
654 struct inode *parent;
656 spin_lock(&dentry->d_lock);
657 parent = dentry->d_parent->d_inode;
658 nodeid = get_fuse_inode(parent)->nodeid;
659 generation = parent->i_generation;
660 spin_unlock(&dentry->d_lock);
662 fh[3] = (u32)(nodeid >> 32);
663 fh[4] = (u32)(nodeid & 0xffffffff);
664 fh[5] = generation;
667 *max_len = len;
668 return encode_parent ? 0x82 : 0x81;
671 static struct dentry *fuse_fh_to_dentry(struct super_block *sb,
672 struct fid *fid, int fh_len, int fh_type)
674 struct fuse_inode_handle handle;
676 if ((fh_type != 0x81 && fh_type != 0x82) || fh_len < 3)
677 return NULL;
679 handle.nodeid = (u64) fid->raw[0] << 32;
680 handle.nodeid |= (u64) fid->raw[1];
681 handle.generation = fid->raw[2];
682 return fuse_get_dentry(sb, &handle);
685 static struct dentry *fuse_fh_to_parent(struct super_block *sb,
686 struct fid *fid, int fh_len, int fh_type)
688 struct fuse_inode_handle parent;
690 if (fh_type != 0x82 || fh_len < 6)
691 return NULL;
693 parent.nodeid = (u64) fid->raw[3] << 32;
694 parent.nodeid |= (u64) fid->raw[4];
695 parent.generation = fid->raw[5];
696 return fuse_get_dentry(sb, &parent);
699 static struct dentry *fuse_get_parent(struct dentry *child)
701 struct inode *child_inode = child->d_inode;
702 struct fuse_conn *fc = get_fuse_conn(child_inode);
703 struct inode *inode;
704 struct dentry *parent;
705 struct fuse_entry_out outarg;
706 struct qstr name;
707 int err;
709 if (!fc->export_support)
710 return ERR_PTR(-ESTALE);
712 name.len = 2;
713 name.name = "..";
714 err = fuse_lookup_name(child_inode->i_sb, get_node_id(child_inode),
715 &name, &outarg, &inode);
716 if (err) {
717 if (err == -ENOENT)
718 return ERR_PTR(-ESTALE);
719 return ERR_PTR(err);
722 parent = d_obtain_alias(inode);
723 if (!IS_ERR(parent) && get_node_id(inode) != FUSE_ROOT_ID) {
724 parent->d_op = &fuse_dentry_operations;
725 fuse_invalidate_entry_cache(parent);
728 return parent;
731 static const struct export_operations fuse_export_operations = {
732 .fh_to_dentry = fuse_fh_to_dentry,
733 .fh_to_parent = fuse_fh_to_parent,
734 .encode_fh = fuse_encode_fh,
735 .get_parent = fuse_get_parent,
738 static const struct super_operations fuse_super_operations = {
739 .alloc_inode = fuse_alloc_inode,
740 .destroy_inode = fuse_destroy_inode,
741 .evict_inode = fuse_evict_inode,
742 .drop_inode = generic_delete_inode,
743 .remount_fs = fuse_remount_fs,
744 .put_super = fuse_put_super,
745 .umount_begin = fuse_umount_begin,
746 .statfs = fuse_statfs,
747 .show_options = fuse_show_options,
750 static void sanitize_global_limit(unsigned *limit)
752 if (*limit == 0)
753 *limit = ((num_physpages << PAGE_SHIFT) >> 13) /
754 sizeof(struct fuse_req);
756 if (*limit >= 1 << 16)
757 *limit = (1 << 16) - 1;
760 static int set_global_limit(const char *val, struct kernel_param *kp)
762 int rv;
764 rv = param_set_uint(val, kp);
765 if (rv)
766 return rv;
768 sanitize_global_limit((unsigned *)kp->arg);
770 return 0;
773 static void process_init_limits(struct fuse_conn *fc, struct fuse_init_out *arg)
775 int cap_sys_admin = capable(CAP_SYS_ADMIN);
777 if (arg->minor < 13)
778 return;
780 sanitize_global_limit(&max_user_bgreq);
781 sanitize_global_limit(&max_user_congthresh);
783 if (arg->max_background) {
784 fc->max_background = arg->max_background;
786 if (!cap_sys_admin && fc->max_background > max_user_bgreq)
787 fc->max_background = max_user_bgreq;
789 if (arg->congestion_threshold) {
790 fc->congestion_threshold = arg->congestion_threshold;
792 if (!cap_sys_admin &&
793 fc->congestion_threshold > max_user_congthresh)
794 fc->congestion_threshold = max_user_congthresh;
798 static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
800 struct fuse_init_out *arg = &req->misc.init_out;
802 if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION)
803 fc->conn_error = 1;
804 else {
805 unsigned long ra_pages;
807 process_init_limits(fc, arg);
809 if (arg->minor >= 6) {
810 ra_pages = arg->max_readahead / PAGE_CACHE_SIZE;
811 if (arg->flags & FUSE_ASYNC_READ)
812 fc->async_read = 1;
813 if (!(arg->flags & FUSE_POSIX_LOCKS))
814 fc->no_lock = 1;
815 if (arg->flags & FUSE_ATOMIC_O_TRUNC)
816 fc->atomic_o_trunc = 1;
817 if (arg->minor >= 9) {
818 /* LOOKUP has dependency on proto version */
819 if (arg->flags & FUSE_EXPORT_SUPPORT)
820 fc->export_support = 1;
822 if (arg->flags & FUSE_BIG_WRITES)
823 fc->big_writes = 1;
824 if (arg->flags & FUSE_DONT_MASK)
825 fc->dont_mask = 1;
826 } else {
827 ra_pages = fc->max_read / PAGE_CACHE_SIZE;
828 fc->no_lock = 1;
831 fc->bdi.ra_pages = min(fc->bdi.ra_pages, ra_pages);
832 fc->minor = arg->minor;
833 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
834 fc->max_write = max_t(unsigned, 4096, fc->max_write);
835 fc->conn_init = 1;
837 fc->blocked = 0;
838 wake_up_all(&fc->blocked_waitq);
841 static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req)
843 struct fuse_init_in *arg = &req->misc.init_in;
845 arg->major = FUSE_KERNEL_VERSION;
846 arg->minor = FUSE_KERNEL_MINOR_VERSION;
847 arg->max_readahead = fc->bdi.ra_pages * PAGE_CACHE_SIZE;
848 arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_ATOMIC_O_TRUNC |
849 FUSE_EXPORT_SUPPORT | FUSE_BIG_WRITES | FUSE_DONT_MASK;
850 req->in.h.opcode = FUSE_INIT;
851 req->in.numargs = 1;
852 req->in.args[0].size = sizeof(*arg);
853 req->in.args[0].value = arg;
854 req->out.numargs = 1;
855 /* Variable length argument used for backward compatibility
856 with interface version < 7.5. Rest of init_out is zeroed
857 by do_get_request(), so a short reply is not a problem */
858 req->out.argvar = 1;
859 req->out.args[0].size = sizeof(struct fuse_init_out);
860 req->out.args[0].value = &req->misc.init_out;
861 req->end = process_init_reply;
862 fuse_request_send_background(fc, req);
865 static void fuse_free_conn(struct fuse_conn *fc)
867 kfree(fc);
870 static int fuse_bdi_init(struct fuse_conn *fc, struct super_block *sb)
872 int err;
874 fc->bdi.name = "fuse";
875 fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
876 fc->bdi.unplug_io_fn = default_unplug_io_fn;
877 /* fuse does it's own writeback accounting */
878 fc->bdi.capabilities = BDI_CAP_NO_ACCT_WB;
880 err = bdi_init(&fc->bdi);
881 if (err)
882 return err;
884 fc->bdi_initialized = 1;
886 if (sb->s_bdev) {
887 err = bdi_register(&fc->bdi, NULL, "%u:%u-fuseblk",
888 MAJOR(fc->dev), MINOR(fc->dev));
889 } else {
890 err = bdi_register_dev(&fc->bdi, fc->dev);
893 if (err)
894 return err;
897 * For a single fuse filesystem use max 1% of dirty +
898 * writeback threshold.
900 * This gives about 1M of write buffer for memory maps on a
901 * machine with 1G and 10% dirty_ratio, which should be more
902 * than enough.
904 * Privileged users can raise it by writing to
906 * /sys/class/bdi/<bdi>/max_ratio
908 bdi_set_max_ratio(&fc->bdi, 1);
910 return 0;
913 static int fuse_fill_super(struct super_block *sb, void *data, int silent)
915 struct fuse_conn *fc;
916 struct inode *root;
917 struct fuse_mount_data d;
918 struct file *file;
919 struct dentry *root_dentry;
920 struct fuse_req *init_req;
921 int err;
922 int is_bdev = sb->s_bdev != NULL;
924 err = -EINVAL;
925 if (sb->s_flags & MS_MANDLOCK)
926 goto err;
928 if (!parse_fuse_opt((char *) data, &d, is_bdev))
929 goto err;
931 if (is_bdev) {
932 #ifdef CONFIG_BLOCK
933 err = -EINVAL;
934 if (!sb_set_blocksize(sb, d.blksize))
935 goto err;
936 #endif
937 } else {
938 sb->s_blocksize = PAGE_CACHE_SIZE;
939 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
941 sb->s_magic = FUSE_SUPER_MAGIC;
942 sb->s_op = &fuse_super_operations;
943 sb->s_maxbytes = MAX_LFS_FILESIZE;
944 sb->s_export_op = &fuse_export_operations;
946 file = fget(d.fd);
947 err = -EINVAL;
948 if (!file)
949 goto err;
951 if (file->f_op != &fuse_dev_operations)
952 goto err_fput;
954 fc = kmalloc(sizeof(*fc), GFP_KERNEL);
955 err = -ENOMEM;
956 if (!fc)
957 goto err_fput;
959 fuse_conn_init(fc);
961 fc->dev = sb->s_dev;
962 fc->sb = sb;
963 err = fuse_bdi_init(fc, sb);
964 if (err)
965 goto err_put_conn;
967 sb->s_bdi = &fc->bdi;
969 /* Handle umasking inside the fuse code */
970 if (sb->s_flags & MS_POSIXACL)
971 fc->dont_mask = 1;
972 sb->s_flags |= MS_POSIXACL;
974 fc->release = fuse_free_conn;
975 fc->flags = d.flags;
976 fc->user_id = d.user_id;
977 fc->group_id = d.group_id;
978 fc->max_read = max_t(unsigned, 4096, d.max_read);
980 /* Used by get_root_inode() */
981 sb->s_fs_info = fc;
983 err = -ENOMEM;
984 root = fuse_get_root_inode(sb, d.rootmode);
985 if (!root)
986 goto err_put_conn;
988 root_dentry = d_alloc_root(root);
989 if (!root_dentry) {
990 iput(root);
991 goto err_put_conn;
994 init_req = fuse_request_alloc();
995 if (!init_req)
996 goto err_put_root;
998 if (is_bdev) {
999 fc->destroy_req = fuse_request_alloc();
1000 if (!fc->destroy_req)
1001 goto err_free_init_req;
1004 mutex_lock(&fuse_mutex);
1005 err = -EINVAL;
1006 if (file->private_data)
1007 goto err_unlock;
1009 err = fuse_ctl_add_conn(fc);
1010 if (err)
1011 goto err_unlock;
1013 list_add_tail(&fc->entry, &fuse_conn_list);
1014 sb->s_root = root_dentry;
1015 fc->connected = 1;
1016 file->private_data = fuse_conn_get(fc);
1017 mutex_unlock(&fuse_mutex);
1019 * atomic_dec_and_test() in fput() provides the necessary
1020 * memory barrier for file->private_data to be visible on all
1021 * CPUs after this
1023 fput(file);
1025 fuse_send_init(fc, init_req);
1027 return 0;
1029 err_unlock:
1030 mutex_unlock(&fuse_mutex);
1031 err_free_init_req:
1032 fuse_request_free(init_req);
1033 err_put_root:
1034 dput(root_dentry);
1035 err_put_conn:
1036 fuse_bdi_destroy(fc);
1037 fuse_conn_put(fc);
1038 err_fput:
1039 fput(file);
1040 err:
1041 return err;
1044 static int fuse_get_sb(struct file_system_type *fs_type,
1045 int flags, const char *dev_name,
1046 void *raw_data, struct vfsmount *mnt)
1048 return get_sb_nodev(fs_type, flags, raw_data, fuse_fill_super, mnt);
1051 static void fuse_kill_sb_anon(struct super_block *sb)
1053 struct fuse_conn *fc = get_fuse_conn_super(sb);
1055 if (fc) {
1056 down_write(&fc->killsb);
1057 fc->sb = NULL;
1058 up_write(&fc->killsb);
1061 kill_anon_super(sb);
1064 static struct file_system_type fuse_fs_type = {
1065 .owner = THIS_MODULE,
1066 .name = "fuse",
1067 .fs_flags = FS_HAS_SUBTYPE,
1068 .get_sb = fuse_get_sb,
1069 .kill_sb = fuse_kill_sb_anon,
1072 #ifdef CONFIG_BLOCK
1073 static int fuse_get_sb_blk(struct file_system_type *fs_type,
1074 int flags, const char *dev_name,
1075 void *raw_data, struct vfsmount *mnt)
1077 return get_sb_bdev(fs_type, flags, dev_name, raw_data, fuse_fill_super,
1078 mnt);
1081 static void fuse_kill_sb_blk(struct super_block *sb)
1083 struct fuse_conn *fc = get_fuse_conn_super(sb);
1085 if (fc) {
1086 down_write(&fc->killsb);
1087 fc->sb = NULL;
1088 up_write(&fc->killsb);
1091 kill_block_super(sb);
1094 static struct file_system_type fuseblk_fs_type = {
1095 .owner = THIS_MODULE,
1096 .name = "fuseblk",
1097 .get_sb = fuse_get_sb_blk,
1098 .kill_sb = fuse_kill_sb_blk,
1099 .fs_flags = FS_REQUIRES_DEV | FS_HAS_SUBTYPE,
1102 static inline int register_fuseblk(void)
1104 return register_filesystem(&fuseblk_fs_type);
1107 static inline void unregister_fuseblk(void)
1109 unregister_filesystem(&fuseblk_fs_type);
1111 #else
1112 static inline int register_fuseblk(void)
1114 return 0;
1117 static inline void unregister_fuseblk(void)
1120 #endif
1122 static void fuse_inode_init_once(void *foo)
1124 struct inode *inode = foo;
1126 inode_init_once(inode);
1129 static int __init fuse_fs_init(void)
1131 int err;
1133 err = register_filesystem(&fuse_fs_type);
1134 if (err)
1135 goto out;
1137 err = register_fuseblk();
1138 if (err)
1139 goto out_unreg;
1141 fuse_inode_cachep = kmem_cache_create("fuse_inode",
1142 sizeof(struct fuse_inode),
1143 0, SLAB_HWCACHE_ALIGN,
1144 fuse_inode_init_once);
1145 err = -ENOMEM;
1146 if (!fuse_inode_cachep)
1147 goto out_unreg2;
1149 return 0;
1151 out_unreg2:
1152 unregister_fuseblk();
1153 out_unreg:
1154 unregister_filesystem(&fuse_fs_type);
1155 out:
1156 return err;
1159 static void fuse_fs_cleanup(void)
1161 unregister_filesystem(&fuse_fs_type);
1162 unregister_fuseblk();
1163 kmem_cache_destroy(fuse_inode_cachep);
1166 static struct kobject *fuse_kobj;
1167 static struct kobject *connections_kobj;
1169 static int fuse_sysfs_init(void)
1171 int err;
1173 fuse_kobj = kobject_create_and_add("fuse", fs_kobj);
1174 if (!fuse_kobj) {
1175 err = -ENOMEM;
1176 goto out_err;
1179 connections_kobj = kobject_create_and_add("connections", fuse_kobj);
1180 if (!connections_kobj) {
1181 err = -ENOMEM;
1182 goto out_fuse_unregister;
1185 return 0;
1187 out_fuse_unregister:
1188 kobject_put(fuse_kobj);
1189 out_err:
1190 return err;
1193 static void fuse_sysfs_cleanup(void)
1195 kobject_put(connections_kobj);
1196 kobject_put(fuse_kobj);
1199 static int __init fuse_init(void)
1201 int res;
1203 printk(KERN_INFO "fuse init (API version %i.%i)\n",
1204 FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
1206 INIT_LIST_HEAD(&fuse_conn_list);
1207 res = fuse_fs_init();
1208 if (res)
1209 goto err;
1211 res = fuse_dev_init();
1212 if (res)
1213 goto err_fs_cleanup;
1215 res = fuse_sysfs_init();
1216 if (res)
1217 goto err_dev_cleanup;
1219 res = fuse_ctl_init();
1220 if (res)
1221 goto err_sysfs_cleanup;
1223 sanitize_global_limit(&max_user_bgreq);
1224 sanitize_global_limit(&max_user_congthresh);
1226 return 0;
1228 err_sysfs_cleanup:
1229 fuse_sysfs_cleanup();
1230 err_dev_cleanup:
1231 fuse_dev_cleanup();
1232 err_fs_cleanup:
1233 fuse_fs_cleanup();
1234 err:
1235 return res;
1238 static void __exit fuse_exit(void)
1240 printk(KERN_DEBUG "fuse exit\n");
1242 fuse_ctl_cleanup();
1243 fuse_sysfs_cleanup();
1244 fuse_fs_cleanup();
1245 fuse_dev_cleanup();
1248 module_init(fuse_init);
1249 module_exit(fuse_exit);