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.
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 {
65 unsigned fd_present:1;
66 unsigned rootmode_present:1;
67 unsigned user_id_present:1;
68 unsigned group_id_present:1;
74 struct fuse_forget_link *fuse_alloc_forget(void)
76 return kzalloc(sizeof(struct fuse_forget_link), GFP_KERNEL);
79 static struct inode *fuse_alloc_inode(struct super_block *sb)
82 struct fuse_inode *fi;
84 inode = kmem_cache_alloc(fuse_inode_cachep, GFP_KERNEL);
88 fi = get_fuse_inode(inode);
96 INIT_LIST_HEAD(&fi->write_files);
97 INIT_LIST_HEAD(&fi->queued_writes);
98 INIT_LIST_HEAD(&fi->writepages);
99 init_waitqueue_head(&fi->page_waitq);
100 fi->forget = fuse_alloc_forget();
102 kmem_cache_free(fuse_inode_cachep, inode);
109 static void fuse_i_callback(struct rcu_head *head)
111 struct inode *inode = container_of(head, struct inode, i_rcu);
112 INIT_LIST_HEAD(&inode->i_dentry);
113 kmem_cache_free(fuse_inode_cachep, inode);
116 static void fuse_destroy_inode(struct inode *inode)
118 struct fuse_inode *fi = get_fuse_inode(inode);
119 BUG_ON(!list_empty(&fi->write_files));
120 BUG_ON(!list_empty(&fi->queued_writes));
122 call_rcu(&inode->i_rcu, fuse_i_callback);
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_queue_forget(fc, fi->forget, fi->nodeid, fi->nlookup);
137 static int fuse_remount_fs(struct super_block *sb, int *flags, char *data)
139 if (*flags & MS_MANDLOCK)
146 * ino_t is 32-bits on 32-bit arch. We have to squash the 64-bit value down
147 * so that it will fit.
149 static ino_t fuse_squash_ino(u64 ino64)
151 ino_t ino = (ino_t) ino64;
152 if (sizeof(ino_t) < sizeof(u64))
153 ino ^= ino64 >> (sizeof(u64) - sizeof(ino_t)) * 8;
157 void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
160 struct fuse_conn *fc = get_fuse_conn(inode);
161 struct fuse_inode *fi = get_fuse_inode(inode);
163 fi->attr_version = ++fc->attr_version;
164 fi->i_time = attr_valid;
166 inode->i_ino = fuse_squash_ino(attr->ino);
167 inode->i_mode = (inode->i_mode & S_IFMT) | (attr->mode & 07777);
168 set_nlink(inode, attr->nlink);
169 inode->i_uid = attr->uid;
170 inode->i_gid = attr->gid;
171 inode->i_blocks = attr->blocks;
172 inode->i_atime.tv_sec = attr->atime;
173 inode->i_atime.tv_nsec = attr->atimensec;
174 inode->i_mtime.tv_sec = attr->mtime;
175 inode->i_mtime.tv_nsec = attr->mtimensec;
176 inode->i_ctime.tv_sec = attr->ctime;
177 inode->i_ctime.tv_nsec = attr->ctimensec;
179 if (attr->blksize != 0)
180 inode->i_blkbits = ilog2(attr->blksize);
182 inode->i_blkbits = inode->i_sb->s_blocksize_bits;
185 * Don't set the sticky bit in i_mode, unless we want the VFS
186 * to check permissions. This prevents failures due to the
187 * check in may_delete().
189 fi->orig_i_mode = inode->i_mode;
190 if (!(fc->flags & FUSE_DEFAULT_PERMISSIONS))
191 inode->i_mode &= ~S_ISVTX;
193 fi->orig_ino = attr->ino;
196 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
197 u64 attr_valid, u64 attr_version)
199 struct fuse_conn *fc = get_fuse_conn(inode);
200 struct fuse_inode *fi = get_fuse_inode(inode);
203 spin_lock(&fc->lock);
204 if ((attr_version != 0 && fi->attr_version > attr_version) ||
205 test_bit(FUSE_I_SIZE_UNSTABLE, &fi->state)) {
206 spin_unlock(&fc->lock);
210 fuse_change_attributes_common(inode, attr, attr_valid);
212 oldsize = inode->i_size;
213 i_size_write(inode, attr->size);
214 spin_unlock(&fc->lock);
216 if (S_ISREG(inode->i_mode) && oldsize != attr->size) {
217 truncate_pagecache(inode, oldsize, attr->size);
218 invalidate_inode_pages2(inode->i_mapping);
222 static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
224 inode->i_mode = attr->mode & S_IFMT;
225 inode->i_size = attr->size;
226 if (S_ISREG(inode->i_mode)) {
227 fuse_init_common(inode);
228 fuse_init_file_inode(inode);
229 } else if (S_ISDIR(inode->i_mode))
230 fuse_init_dir(inode);
231 else if (S_ISLNK(inode->i_mode))
232 fuse_init_symlink(inode);
233 else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
234 S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
235 fuse_init_common(inode);
236 init_special_inode(inode, inode->i_mode,
237 new_decode_dev(attr->rdev));
242 int fuse_inode_eq(struct inode *inode, void *_nodeidp)
244 u64 nodeid = *(u64 *) _nodeidp;
245 if (get_node_id(inode) == nodeid)
251 static int fuse_inode_set(struct inode *inode, void *_nodeidp)
253 u64 nodeid = *(u64 *) _nodeidp;
254 get_fuse_inode(inode)->nodeid = nodeid;
258 struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
259 int generation, struct fuse_attr *attr,
260 u64 attr_valid, u64 attr_version)
263 struct fuse_inode *fi;
264 struct fuse_conn *fc = get_fuse_conn_super(sb);
267 inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid);
271 if ((inode->i_state & I_NEW)) {
272 inode->i_flags |= S_NOATIME|S_NOCMTIME;
273 inode->i_generation = generation;
274 inode->i_data.backing_dev_info = &fc->bdi;
275 fuse_init_inode(inode, attr);
276 unlock_new_inode(inode);
277 } else if ((inode->i_mode ^ attr->mode) & S_IFMT) {
278 /* Inode has changed type, any I/O on the old should fail */
279 make_bad_inode(inode);
284 fi = get_fuse_inode(inode);
285 spin_lock(&fc->lock);
287 spin_unlock(&fc->lock);
288 fuse_change_attributes(inode, attr, attr_valid, attr_version);
293 int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid,
294 loff_t offset, loff_t len)
300 inode = ilookup5(sb, nodeid, fuse_inode_eq, &nodeid);
304 fuse_invalidate_attr(inode);
306 pg_start = offset >> PAGE_CACHE_SHIFT;
310 pg_end = (offset + len - 1) >> PAGE_CACHE_SHIFT;
311 invalidate_inode_pages2_range(inode->i_mapping,
318 static void fuse_umount_begin(struct super_block *sb)
320 fuse_abort_conn(get_fuse_conn_super(sb));
323 static void fuse_send_destroy(struct fuse_conn *fc)
325 struct fuse_req *req = fc->destroy_req;
326 if (req && fc->conn_init) {
327 fc->destroy_req = NULL;
328 req->in.h.opcode = FUSE_DESTROY;
330 fuse_request_send(fc, req);
331 fuse_put_request(fc, req);
335 static void fuse_bdi_destroy(struct fuse_conn *fc)
337 if (fc->bdi_initialized)
338 bdi_destroy(&fc->bdi);
341 void fuse_conn_kill(struct fuse_conn *fc)
343 spin_lock(&fc->lock);
346 spin_unlock(&fc->lock);
347 /* Flush all readers on this fs */
348 kill_fasync(&fc->fasync, SIGIO, POLL_IN);
349 wake_up_all(&fc->waitq);
350 wake_up_all(&fc->blocked_waitq);
351 wake_up_all(&fc->reserved_req_waitq);
352 mutex_lock(&fuse_mutex);
353 list_del(&fc->entry);
354 fuse_ctl_remove_conn(fc);
355 mutex_unlock(&fuse_mutex);
356 fuse_bdi_destroy(fc);
358 EXPORT_SYMBOL_GPL(fuse_conn_kill);
360 static void fuse_put_super(struct super_block *sb)
362 struct fuse_conn *fc = get_fuse_conn_super(sb);
364 fuse_send_destroy(fc);
369 static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
371 stbuf->f_type = FUSE_SUPER_MAGIC;
372 stbuf->f_bsize = attr->bsize;
373 stbuf->f_frsize = attr->frsize;
374 stbuf->f_blocks = attr->blocks;
375 stbuf->f_bfree = attr->bfree;
376 stbuf->f_bavail = attr->bavail;
377 stbuf->f_files = attr->files;
378 stbuf->f_ffree = attr->ffree;
379 stbuf->f_namelen = attr->namelen;
380 /* fsid is left zero */
383 static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf)
385 struct super_block *sb = dentry->d_sb;
386 struct fuse_conn *fc = get_fuse_conn_super(sb);
387 struct fuse_req *req;
388 struct fuse_statfs_out outarg;
391 if (!fuse_allow_task(fc, current)) {
392 buf->f_type = FUSE_SUPER_MAGIC;
396 req = fuse_get_req(fc);
400 memset(&outarg, 0, sizeof(outarg));
402 req->in.h.opcode = FUSE_STATFS;
403 req->in.h.nodeid = get_node_id(dentry->d_inode);
404 req->out.numargs = 1;
405 req->out.args[0].size =
406 fc->minor < 4 ? FUSE_COMPAT_STATFS_SIZE : sizeof(outarg);
407 req->out.args[0].value = &outarg;
408 fuse_request_send(fc, req);
409 err = req->out.h.error;
411 convert_fuse_statfs(buf, &outarg.st);
412 fuse_put_request(fc, req);
421 OPT_DEFAULT_PERMISSIONS,
428 static const match_table_t tokens = {
430 {OPT_ROOTMODE, "rootmode=%o"},
431 {OPT_USER_ID, "user_id=%u"},
432 {OPT_GROUP_ID, "group_id=%u"},
433 {OPT_DEFAULT_PERMISSIONS, "default_permissions"},
434 {OPT_ALLOW_OTHER, "allow_other"},
435 {OPT_MAX_READ, "max_read=%u"},
436 {OPT_BLKSIZE, "blksize=%u"},
440 static int parse_fuse_opt(char *opt, struct fuse_mount_data *d, int is_bdev)
443 memset(d, 0, sizeof(struct fuse_mount_data));
445 d->blksize = FUSE_DEFAULT_BLKSIZE;
447 while ((p = strsep(&opt, ",")) != NULL) {
450 substring_t args[MAX_OPT_ARGS];
454 token = match_token(p, tokens, args);
457 if (match_int(&args[0], &value))
464 if (match_octal(&args[0], &value))
466 if (!fuse_valid_type(value))
469 d->rootmode_present = 1;
473 if (match_int(&args[0], &value))
476 d->user_id_present = 1;
480 if (match_int(&args[0], &value))
483 d->group_id_present = 1;
486 case OPT_DEFAULT_PERMISSIONS:
487 d->flags |= FUSE_DEFAULT_PERMISSIONS;
490 case OPT_ALLOW_OTHER:
491 d->flags |= FUSE_ALLOW_OTHER;
495 if (match_int(&args[0], &value))
501 if (!is_bdev || match_int(&args[0], &value))
511 if (!d->fd_present || !d->rootmode_present ||
512 !d->user_id_present || !d->group_id_present)
518 static int fuse_show_options(struct seq_file *m, struct vfsmount *mnt)
520 struct fuse_conn *fc = get_fuse_conn_super(mnt->mnt_sb);
522 seq_printf(m, ",user_id=%u", fc->user_id);
523 seq_printf(m, ",group_id=%u", fc->group_id);
524 if (fc->flags & FUSE_DEFAULT_PERMISSIONS)
525 seq_puts(m, ",default_permissions");
526 if (fc->flags & FUSE_ALLOW_OTHER)
527 seq_puts(m, ",allow_other");
528 if (fc->max_read != ~0)
529 seq_printf(m, ",max_read=%u", fc->max_read);
530 if (mnt->mnt_sb->s_bdev &&
531 mnt->mnt_sb->s_blocksize != FUSE_DEFAULT_BLKSIZE)
532 seq_printf(m, ",blksize=%lu", mnt->mnt_sb->s_blocksize);
536 void fuse_conn_init(struct fuse_conn *fc)
538 memset(fc, 0, sizeof(*fc));
539 spin_lock_init(&fc->lock);
540 mutex_init(&fc->inst_mutex);
541 init_rwsem(&fc->killsb);
542 atomic_set(&fc->count, 1);
543 init_waitqueue_head(&fc->waitq);
544 init_waitqueue_head(&fc->blocked_waitq);
545 init_waitqueue_head(&fc->reserved_req_waitq);
546 INIT_LIST_HEAD(&fc->pending);
547 INIT_LIST_HEAD(&fc->processing);
548 INIT_LIST_HEAD(&fc->io);
549 INIT_LIST_HEAD(&fc->interrupts);
550 INIT_LIST_HEAD(&fc->bg_queue);
551 INIT_LIST_HEAD(&fc->entry);
552 fc->forget_list_tail = &fc->forget_list_head;
553 atomic_set(&fc->num_waiting, 0);
554 fc->max_background = FUSE_DEFAULT_MAX_BACKGROUND;
555 fc->congestion_threshold = FUSE_DEFAULT_CONGESTION_THRESHOLD;
557 fc->polled_files = RB_ROOT;
560 fc->attr_version = 1;
561 get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key));
563 EXPORT_SYMBOL_GPL(fuse_conn_init);
565 void fuse_conn_put(struct fuse_conn *fc)
567 if (atomic_dec_and_test(&fc->count)) {
569 fuse_request_free(fc->destroy_req);
570 mutex_destroy(&fc->inst_mutex);
574 EXPORT_SYMBOL_GPL(fuse_conn_put);
576 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc)
578 atomic_inc(&fc->count);
581 EXPORT_SYMBOL_GPL(fuse_conn_get);
583 static struct inode *fuse_get_root_inode(struct super_block *sb, unsigned mode)
585 struct fuse_attr attr;
586 memset(&attr, 0, sizeof(attr));
589 attr.ino = FUSE_ROOT_ID;
591 return fuse_iget(sb, 1, 0, &attr, 0, 0);
594 struct fuse_inode_handle {
599 static struct dentry *fuse_get_dentry(struct super_block *sb,
600 struct fuse_inode_handle *handle)
602 struct fuse_conn *fc = get_fuse_conn_super(sb);
604 struct dentry *entry;
607 if (handle->nodeid == 0)
610 inode = ilookup5(sb, handle->nodeid, fuse_inode_eq, &handle->nodeid);
612 struct fuse_entry_out outarg;
615 if (!fc->export_support)
620 err = fuse_lookup_name(sb, handle->nodeid, &name, &outarg,
622 if (err && err != -ENOENT)
629 if (get_node_id(inode) != handle->nodeid)
633 if (inode->i_generation != handle->generation)
636 entry = d_obtain_alias(inode);
637 if (!IS_ERR(entry) && get_node_id(inode) != FUSE_ROOT_ID)
638 fuse_invalidate_entry_cache(entry);
648 static int fuse_encode_fh(struct dentry *dentry, u32 *fh, int *max_len,
651 struct inode *inode = dentry->d_inode;
652 bool encode_parent = connectable && !S_ISDIR(inode->i_mode);
653 int len = encode_parent ? 6 : 3;
657 if (*max_len < len) {
662 nodeid = get_fuse_inode(inode)->nodeid;
663 generation = inode->i_generation;
665 fh[0] = (u32)(nodeid >> 32);
666 fh[1] = (u32)(nodeid & 0xffffffff);
670 struct inode *parent;
672 spin_lock(&dentry->d_lock);
673 parent = dentry->d_parent->d_inode;
674 nodeid = get_fuse_inode(parent)->nodeid;
675 generation = parent->i_generation;
676 spin_unlock(&dentry->d_lock);
678 fh[3] = (u32)(nodeid >> 32);
679 fh[4] = (u32)(nodeid & 0xffffffff);
684 return encode_parent ? 0x82 : 0x81;
687 static struct dentry *fuse_fh_to_dentry(struct super_block *sb,
688 struct fid *fid, int fh_len, int fh_type)
690 struct fuse_inode_handle handle;
692 if ((fh_type != 0x81 && fh_type != 0x82) || fh_len < 3)
695 handle.nodeid = (u64) fid->raw[0] << 32;
696 handle.nodeid |= (u64) fid->raw[1];
697 handle.generation = fid->raw[2];
698 return fuse_get_dentry(sb, &handle);
701 static struct dentry *fuse_fh_to_parent(struct super_block *sb,
702 struct fid *fid, int fh_len, int fh_type)
704 struct fuse_inode_handle parent;
706 if (fh_type != 0x82 || fh_len < 6)
709 parent.nodeid = (u64) fid->raw[3] << 32;
710 parent.nodeid |= (u64) fid->raw[4];
711 parent.generation = fid->raw[5];
712 return fuse_get_dentry(sb, &parent);
715 static struct dentry *fuse_get_parent(struct dentry *child)
717 struct inode *child_inode = child->d_inode;
718 struct fuse_conn *fc = get_fuse_conn(child_inode);
720 struct dentry *parent;
721 struct fuse_entry_out outarg;
725 if (!fc->export_support)
726 return ERR_PTR(-ESTALE);
730 err = fuse_lookup_name(child_inode->i_sb, get_node_id(child_inode),
731 &name, &outarg, &inode);
734 return ERR_PTR(-ESTALE);
738 parent = d_obtain_alias(inode);
739 if (!IS_ERR(parent) && get_node_id(inode) != FUSE_ROOT_ID)
740 fuse_invalidate_entry_cache(parent);
745 static const struct export_operations fuse_export_operations = {
746 .fh_to_dentry = fuse_fh_to_dentry,
747 .fh_to_parent = fuse_fh_to_parent,
748 .encode_fh = fuse_encode_fh,
749 .get_parent = fuse_get_parent,
752 static const struct super_operations fuse_super_operations = {
753 .alloc_inode = fuse_alloc_inode,
754 .destroy_inode = fuse_destroy_inode,
755 .evict_inode = fuse_evict_inode,
756 .drop_inode = generic_delete_inode,
757 .remount_fs = fuse_remount_fs,
758 .put_super = fuse_put_super,
759 .umount_begin = fuse_umount_begin,
760 .statfs = fuse_statfs,
761 .show_options = fuse_show_options,
764 static void sanitize_global_limit(unsigned *limit)
767 *limit = ((num_physpages << PAGE_SHIFT) >> 13) /
768 sizeof(struct fuse_req);
770 if (*limit >= 1 << 16)
771 *limit = (1 << 16) - 1;
774 static int set_global_limit(const char *val, struct kernel_param *kp)
778 rv = param_set_uint(val, kp);
782 sanitize_global_limit((unsigned *)kp->arg);
787 static void process_init_limits(struct fuse_conn *fc, struct fuse_init_out *arg)
789 int cap_sys_admin = capable(CAP_SYS_ADMIN);
794 sanitize_global_limit(&max_user_bgreq);
795 sanitize_global_limit(&max_user_congthresh);
797 if (arg->max_background) {
798 fc->max_background = arg->max_background;
800 if (!cap_sys_admin && fc->max_background > max_user_bgreq)
801 fc->max_background = max_user_bgreq;
803 if (arg->congestion_threshold) {
804 fc->congestion_threshold = arg->congestion_threshold;
806 if (!cap_sys_admin &&
807 fc->congestion_threshold > max_user_congthresh)
808 fc->congestion_threshold = max_user_congthresh;
812 static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
814 struct fuse_init_out *arg = &req->misc.init_out;
816 if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION)
819 unsigned long ra_pages;
821 process_init_limits(fc, arg);
823 if (arg->minor >= 6) {
824 ra_pages = arg->max_readahead / PAGE_CACHE_SIZE;
825 if (arg->flags & FUSE_ASYNC_READ)
827 if (!(arg->flags & FUSE_POSIX_LOCKS))
829 if (arg->minor >= 17) {
830 if (!(arg->flags & FUSE_FLOCK_LOCKS))
833 if (!(arg->flags & FUSE_POSIX_LOCKS))
836 if (arg->flags & FUSE_ATOMIC_O_TRUNC)
837 fc->atomic_o_trunc = 1;
838 if (arg->minor >= 9) {
839 /* LOOKUP has dependency on proto version */
840 if (arg->flags & FUSE_EXPORT_SUPPORT)
841 fc->export_support = 1;
843 if (arg->flags & FUSE_BIG_WRITES)
845 if (arg->flags & FUSE_DONT_MASK)
848 ra_pages = fc->max_read / PAGE_CACHE_SIZE;
853 fc->bdi.ra_pages = min(fc->bdi.ra_pages, ra_pages);
854 fc->minor = arg->minor;
855 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
856 fc->max_write = max_t(unsigned, 4096, fc->max_write);
860 wake_up_all(&fc->blocked_waitq);
863 static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req)
865 struct fuse_init_in *arg = &req->misc.init_in;
867 arg->major = FUSE_KERNEL_VERSION;
868 arg->minor = FUSE_KERNEL_MINOR_VERSION;
869 arg->max_readahead = fc->bdi.ra_pages * PAGE_CACHE_SIZE;
870 arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_ATOMIC_O_TRUNC |
871 FUSE_EXPORT_SUPPORT | FUSE_BIG_WRITES | FUSE_DONT_MASK |
873 req->in.h.opcode = FUSE_INIT;
875 req->in.args[0].size = sizeof(*arg);
876 req->in.args[0].value = arg;
877 req->out.numargs = 1;
878 /* Variable length argument used for backward compatibility
879 with interface version < 7.5. Rest of init_out is zeroed
880 by do_get_request(), so a short reply is not a problem */
882 req->out.args[0].size = sizeof(struct fuse_init_out);
883 req->out.args[0].value = &req->misc.init_out;
884 req->end = process_init_reply;
885 fuse_request_send_background(fc, req);
888 static void fuse_free_conn(struct fuse_conn *fc)
893 static int fuse_bdi_init(struct fuse_conn *fc, struct super_block *sb)
897 fc->bdi.name = "fuse";
898 fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
899 /* fuse does it's own writeback accounting */
900 fc->bdi.capabilities = BDI_CAP_NO_ACCT_WB;
902 err = bdi_init(&fc->bdi);
906 fc->bdi_initialized = 1;
909 err = bdi_register(&fc->bdi, NULL, "%u:%u-fuseblk",
910 MAJOR(fc->dev), MINOR(fc->dev));
912 err = bdi_register_dev(&fc->bdi, fc->dev);
919 * For a single fuse filesystem use max 1% of dirty +
920 * writeback threshold.
922 * This gives about 1M of write buffer for memory maps on a
923 * machine with 1G and 10% dirty_ratio, which should be more
926 * Privileged users can raise it by writing to
928 * /sys/class/bdi/<bdi>/max_ratio
930 bdi_set_max_ratio(&fc->bdi, 1);
935 static int fuse_fill_super(struct super_block *sb, void *data, int silent)
937 struct fuse_conn *fc;
939 struct fuse_mount_data d;
941 struct dentry *root_dentry;
942 struct fuse_req *init_req;
944 int is_bdev = sb->s_bdev != NULL;
947 if (sb->s_flags & MS_MANDLOCK)
950 sb->s_flags &= ~MS_NOSEC;
952 if (!parse_fuse_opt((char *) data, &d, is_bdev))
958 if (!sb_set_blocksize(sb, d.blksize))
962 sb->s_blocksize = PAGE_CACHE_SIZE;
963 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
965 sb->s_magic = FUSE_SUPER_MAGIC;
966 sb->s_op = &fuse_super_operations;
967 sb->s_maxbytes = MAX_LFS_FILESIZE;
968 sb->s_export_op = &fuse_export_operations;
975 if (file->f_op != &fuse_dev_operations)
978 fc = kmalloc(sizeof(*fc), GFP_KERNEL);
987 err = fuse_bdi_init(fc, sb);
991 sb->s_bdi = &fc->bdi;
993 /* Handle umasking inside the fuse code */
994 if (sb->s_flags & MS_POSIXACL)
996 sb->s_flags |= MS_POSIXACL;
998 fc->release = fuse_free_conn;
1000 fc->user_id = d.user_id;
1001 fc->group_id = d.group_id;
1002 fc->max_read = max_t(unsigned, 4096, d.max_read);
1004 /* Used by get_root_inode() */
1008 root = fuse_get_root_inode(sb, d.rootmode);
1012 root_dentry = d_alloc_root(root);
1017 /* only now - we want root dentry with NULL ->d_op */
1018 sb->s_d_op = &fuse_dentry_operations;
1020 init_req = fuse_request_alloc();
1025 fc->destroy_req = fuse_request_alloc();
1026 if (!fc->destroy_req)
1027 goto err_free_init_req;
1030 mutex_lock(&fuse_mutex);
1032 if (file->private_data)
1035 err = fuse_ctl_add_conn(fc);
1039 list_add_tail(&fc->entry, &fuse_conn_list);
1040 sb->s_root = root_dentry;
1042 file->private_data = fuse_conn_get(fc);
1043 mutex_unlock(&fuse_mutex);
1045 * atomic_dec_and_test() in fput() provides the necessary
1046 * memory barrier for file->private_data to be visible on all
1051 fuse_send_init(fc, init_req);
1056 mutex_unlock(&fuse_mutex);
1058 fuse_request_free(init_req);
1062 fuse_bdi_destroy(fc);
1070 static struct dentry *fuse_mount(struct file_system_type *fs_type,
1071 int flags, const char *dev_name,
1074 return mount_nodev(fs_type, flags, raw_data, fuse_fill_super);
1077 static void fuse_kill_sb_anon(struct super_block *sb)
1079 struct fuse_conn *fc = get_fuse_conn_super(sb);
1082 down_write(&fc->killsb);
1084 up_write(&fc->killsb);
1087 kill_anon_super(sb);
1090 static struct file_system_type fuse_fs_type = {
1091 .owner = THIS_MODULE,
1093 .fs_flags = FS_HAS_SUBTYPE,
1094 .mount = fuse_mount,
1095 .kill_sb = fuse_kill_sb_anon,
1099 static struct dentry *fuse_mount_blk(struct file_system_type *fs_type,
1100 int flags, const char *dev_name,
1103 return mount_bdev(fs_type, flags, dev_name, raw_data, fuse_fill_super);
1106 static void fuse_kill_sb_blk(struct super_block *sb)
1108 struct fuse_conn *fc = get_fuse_conn_super(sb);
1111 down_write(&fc->killsb);
1113 up_write(&fc->killsb);
1116 kill_block_super(sb);
1119 static struct file_system_type fuseblk_fs_type = {
1120 .owner = THIS_MODULE,
1122 .mount = fuse_mount_blk,
1123 .kill_sb = fuse_kill_sb_blk,
1124 .fs_flags = FS_REQUIRES_DEV | FS_HAS_SUBTYPE,
1127 static inline int register_fuseblk(void)
1129 return register_filesystem(&fuseblk_fs_type);
1132 static inline void unregister_fuseblk(void)
1134 unregister_filesystem(&fuseblk_fs_type);
1137 static inline int register_fuseblk(void)
1142 static inline void unregister_fuseblk(void)
1147 static void fuse_inode_init_once(void *foo)
1149 struct inode *inode = foo;
1151 inode_init_once(inode);
1154 static int __init fuse_fs_init(void)
1158 fuse_inode_cachep = kmem_cache_create("fuse_inode",
1159 sizeof(struct fuse_inode),
1160 0, SLAB_HWCACHE_ALIGN,
1161 fuse_inode_init_once);
1163 if (!fuse_inode_cachep)
1166 err = register_fuseblk();
1170 err = register_filesystem(&fuse_fs_type);
1177 unregister_fuseblk();
1179 kmem_cache_destroy(fuse_inode_cachep);
1184 static void fuse_fs_cleanup(void)
1186 unregister_filesystem(&fuse_fs_type);
1187 unregister_fuseblk();
1188 kmem_cache_destroy(fuse_inode_cachep);
1191 static struct kobject *fuse_kobj;
1192 static struct kobject *connections_kobj;
1194 static int fuse_sysfs_init(void)
1198 fuse_kobj = kobject_create_and_add("fuse", fs_kobj);
1204 connections_kobj = kobject_create_and_add("connections", fuse_kobj);
1205 if (!connections_kobj) {
1207 goto out_fuse_unregister;
1212 out_fuse_unregister:
1213 kobject_put(fuse_kobj);
1218 static void fuse_sysfs_cleanup(void)
1220 kobject_put(connections_kobj);
1221 kobject_put(fuse_kobj);
1224 static int __init fuse_init(void)
1228 printk(KERN_INFO "fuse init (API version %i.%i)\n",
1229 FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
1231 INIT_LIST_HEAD(&fuse_conn_list);
1232 res = fuse_fs_init();
1236 res = fuse_dev_init();
1238 goto err_fs_cleanup;
1240 res = fuse_sysfs_init();
1242 goto err_dev_cleanup;
1244 res = fuse_ctl_init();
1246 goto err_sysfs_cleanup;
1248 sanitize_global_limit(&max_user_bgreq);
1249 sanitize_global_limit(&max_user_congthresh);
1254 fuse_sysfs_cleanup();
1263 static void __exit fuse_exit(void)
1265 printk(KERN_DEBUG "fuse exit\n");
1268 fuse_sysfs_cleanup();
1273 module_init(fuse_init);
1274 module_exit(fuse_exit);