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);
94 INIT_LIST_HEAD(&fi->write_files);
95 INIT_LIST_HEAD(&fi->queued_writes);
96 INIT_LIST_HEAD(&fi->writepages);
97 init_waitqueue_head(&fi->page_waitq);
98 fi->forget = fuse_alloc_forget();
100 kmem_cache_free(fuse_inode_cachep, inode);
107 static void fuse_i_callback(struct rcu_head *head)
109 struct inode *inode = container_of(head, struct inode, i_rcu);
110 INIT_LIST_HEAD(&inode->i_dentry);
111 kmem_cache_free(fuse_inode_cachep, inode);
114 static void fuse_destroy_inode(struct inode *inode)
116 struct fuse_inode *fi = get_fuse_inode(inode);
117 BUG_ON(!list_empty(&fi->write_files));
118 BUG_ON(!list_empty(&fi->queued_writes));
120 call_rcu(&inode->i_rcu, fuse_i_callback);
123 static void fuse_evict_inode(struct inode *inode)
125 truncate_inode_pages(&inode->i_data, 0);
126 end_writeback(inode);
127 if (inode->i_sb->s_flags & MS_ACTIVE) {
128 struct fuse_conn *fc = get_fuse_conn(inode);
129 struct fuse_inode *fi = get_fuse_inode(inode);
130 fuse_queue_forget(fc, fi->forget, fi->nodeid, fi->nlookup);
135 static int fuse_remount_fs(struct super_block *sb, int *flags, char *data)
137 if (*flags & MS_MANDLOCK)
143 void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
146 struct fuse_conn *fc = get_fuse_conn(inode);
147 struct fuse_inode *fi = get_fuse_inode(inode);
149 fi->attr_version = ++fc->attr_version;
150 fi->i_time = attr_valid;
152 inode->i_ino = attr->ino;
153 inode->i_mode = (inode->i_mode & S_IFMT) | (attr->mode & 07777);
154 set_nlink(inode, attr->nlink);
155 inode->i_uid = attr->uid;
156 inode->i_gid = attr->gid;
157 inode->i_blocks = attr->blocks;
158 inode->i_atime.tv_sec = attr->atime;
159 inode->i_atime.tv_nsec = attr->atimensec;
160 inode->i_mtime.tv_sec = attr->mtime;
161 inode->i_mtime.tv_nsec = attr->mtimensec;
162 inode->i_ctime.tv_sec = attr->ctime;
163 inode->i_ctime.tv_nsec = attr->ctimensec;
165 if (attr->blksize != 0)
166 inode->i_blkbits = ilog2(attr->blksize);
168 inode->i_blkbits = inode->i_sb->s_blocksize_bits;
171 * Don't set the sticky bit in i_mode, unless we want the VFS
172 * to check permissions. This prevents failures due to the
173 * check in may_delete().
175 fi->orig_i_mode = inode->i_mode;
176 if (!(fc->flags & FUSE_DEFAULT_PERMISSIONS))
177 inode->i_mode &= ~S_ISVTX;
180 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
181 u64 attr_valid, u64 attr_version)
183 struct fuse_conn *fc = get_fuse_conn(inode);
184 struct fuse_inode *fi = get_fuse_inode(inode);
187 spin_lock(&fc->lock);
188 if (attr_version != 0 && fi->attr_version > attr_version) {
189 spin_unlock(&fc->lock);
193 fuse_change_attributes_common(inode, attr, attr_valid);
195 oldsize = inode->i_size;
196 i_size_write(inode, attr->size);
197 spin_unlock(&fc->lock);
199 if (S_ISREG(inode->i_mode) && oldsize != attr->size) {
200 truncate_pagecache(inode, oldsize, attr->size);
201 invalidate_inode_pages2(inode->i_mapping);
205 static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
207 inode->i_mode = attr->mode & S_IFMT;
208 inode->i_size = attr->size;
209 if (S_ISREG(inode->i_mode)) {
210 fuse_init_common(inode);
211 fuse_init_file_inode(inode);
212 } else if (S_ISDIR(inode->i_mode))
213 fuse_init_dir(inode);
214 else if (S_ISLNK(inode->i_mode))
215 fuse_init_symlink(inode);
216 else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
217 S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
218 fuse_init_common(inode);
219 init_special_inode(inode, inode->i_mode,
220 new_decode_dev(attr->rdev));
225 int fuse_inode_eq(struct inode *inode, void *_nodeidp)
227 u64 nodeid = *(u64 *) _nodeidp;
228 if (get_node_id(inode) == nodeid)
234 static int fuse_inode_set(struct inode *inode, void *_nodeidp)
236 u64 nodeid = *(u64 *) _nodeidp;
237 get_fuse_inode(inode)->nodeid = nodeid;
241 struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
242 int generation, struct fuse_attr *attr,
243 u64 attr_valid, u64 attr_version)
246 struct fuse_inode *fi;
247 struct fuse_conn *fc = get_fuse_conn_super(sb);
250 inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid);
254 if ((inode->i_state & I_NEW)) {
255 inode->i_flags |= S_NOATIME|S_NOCMTIME;
256 inode->i_generation = generation;
257 inode->i_data.backing_dev_info = &fc->bdi;
258 fuse_init_inode(inode, attr);
259 unlock_new_inode(inode);
260 } else if ((inode->i_mode ^ attr->mode) & S_IFMT) {
261 /* Inode has changed type, any I/O on the old should fail */
262 make_bad_inode(inode);
267 fi = get_fuse_inode(inode);
268 spin_lock(&fc->lock);
270 spin_unlock(&fc->lock);
271 fuse_change_attributes(inode, attr, attr_valid, attr_version);
276 int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid,
277 loff_t offset, loff_t len)
283 inode = ilookup5(sb, nodeid, fuse_inode_eq, &nodeid);
287 fuse_invalidate_attr(inode);
289 pg_start = offset >> PAGE_CACHE_SHIFT;
293 pg_end = (offset + len - 1) >> PAGE_CACHE_SHIFT;
294 invalidate_inode_pages2_range(inode->i_mapping,
301 static void fuse_umount_begin(struct super_block *sb)
303 fuse_abort_conn(get_fuse_conn_super(sb));
306 static void fuse_send_destroy(struct fuse_conn *fc)
308 struct fuse_req *req = fc->destroy_req;
309 if (req && fc->conn_init) {
310 fc->destroy_req = NULL;
311 req->in.h.opcode = FUSE_DESTROY;
313 fuse_request_send(fc, req);
314 fuse_put_request(fc, req);
318 static void fuse_bdi_destroy(struct fuse_conn *fc)
320 if (fc->bdi_initialized)
321 bdi_destroy(&fc->bdi);
324 void fuse_conn_kill(struct fuse_conn *fc)
326 spin_lock(&fc->lock);
329 spin_unlock(&fc->lock);
330 /* Flush all readers on this fs */
331 kill_fasync(&fc->fasync, SIGIO, POLL_IN);
332 wake_up_all(&fc->waitq);
333 wake_up_all(&fc->blocked_waitq);
334 wake_up_all(&fc->reserved_req_waitq);
335 mutex_lock(&fuse_mutex);
336 list_del(&fc->entry);
337 fuse_ctl_remove_conn(fc);
338 mutex_unlock(&fuse_mutex);
339 fuse_bdi_destroy(fc);
341 EXPORT_SYMBOL_GPL(fuse_conn_kill);
343 static void fuse_put_super(struct super_block *sb)
345 struct fuse_conn *fc = get_fuse_conn_super(sb);
347 fuse_send_destroy(fc);
352 static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
354 stbuf->f_type = FUSE_SUPER_MAGIC;
355 stbuf->f_bsize = attr->bsize;
356 stbuf->f_frsize = attr->frsize;
357 stbuf->f_blocks = attr->blocks;
358 stbuf->f_bfree = attr->bfree;
359 stbuf->f_bavail = attr->bavail;
360 stbuf->f_files = attr->files;
361 stbuf->f_ffree = attr->ffree;
362 stbuf->f_namelen = attr->namelen;
363 /* fsid is left zero */
366 static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf)
368 struct super_block *sb = dentry->d_sb;
369 struct fuse_conn *fc = get_fuse_conn_super(sb);
370 struct fuse_req *req;
371 struct fuse_statfs_out outarg;
374 if (!fuse_allow_task(fc, current)) {
375 buf->f_type = FUSE_SUPER_MAGIC;
379 req = fuse_get_req(fc);
383 memset(&outarg, 0, sizeof(outarg));
385 req->in.h.opcode = FUSE_STATFS;
386 req->in.h.nodeid = get_node_id(dentry->d_inode);
387 req->out.numargs = 1;
388 req->out.args[0].size =
389 fc->minor < 4 ? FUSE_COMPAT_STATFS_SIZE : sizeof(outarg);
390 req->out.args[0].value = &outarg;
391 fuse_request_send(fc, req);
392 err = req->out.h.error;
394 convert_fuse_statfs(buf, &outarg.st);
395 fuse_put_request(fc, req);
404 OPT_DEFAULT_PERMISSIONS,
411 static const match_table_t tokens = {
413 {OPT_ROOTMODE, "rootmode=%o"},
414 {OPT_USER_ID, "user_id=%u"},
415 {OPT_GROUP_ID, "group_id=%u"},
416 {OPT_DEFAULT_PERMISSIONS, "default_permissions"},
417 {OPT_ALLOW_OTHER, "allow_other"},
418 {OPT_MAX_READ, "max_read=%u"},
419 {OPT_BLKSIZE, "blksize=%u"},
423 static int parse_fuse_opt(char *opt, struct fuse_mount_data *d, int is_bdev)
426 memset(d, 0, sizeof(struct fuse_mount_data));
428 d->blksize = FUSE_DEFAULT_BLKSIZE;
430 while ((p = strsep(&opt, ",")) != NULL) {
433 substring_t args[MAX_OPT_ARGS];
437 token = match_token(p, tokens, args);
440 if (match_int(&args[0], &value))
447 if (match_octal(&args[0], &value))
449 if (!fuse_valid_type(value))
452 d->rootmode_present = 1;
456 if (match_int(&args[0], &value))
459 d->user_id_present = 1;
463 if (match_int(&args[0], &value))
466 d->group_id_present = 1;
469 case OPT_DEFAULT_PERMISSIONS:
470 d->flags |= FUSE_DEFAULT_PERMISSIONS;
473 case OPT_ALLOW_OTHER:
474 d->flags |= FUSE_ALLOW_OTHER;
478 if (match_int(&args[0], &value))
484 if (!is_bdev || match_int(&args[0], &value))
494 if (!d->fd_present || !d->rootmode_present ||
495 !d->user_id_present || !d->group_id_present)
501 static int fuse_show_options(struct seq_file *m, struct vfsmount *mnt)
503 struct fuse_conn *fc = get_fuse_conn_super(mnt->mnt_sb);
505 seq_printf(m, ",user_id=%u", fc->user_id);
506 seq_printf(m, ",group_id=%u", fc->group_id);
507 if (fc->flags & FUSE_DEFAULT_PERMISSIONS)
508 seq_puts(m, ",default_permissions");
509 if (fc->flags & FUSE_ALLOW_OTHER)
510 seq_puts(m, ",allow_other");
511 if (fc->max_read != ~0)
512 seq_printf(m, ",max_read=%u", fc->max_read);
513 if (mnt->mnt_sb->s_bdev &&
514 mnt->mnt_sb->s_blocksize != FUSE_DEFAULT_BLKSIZE)
515 seq_printf(m, ",blksize=%lu", mnt->mnt_sb->s_blocksize);
519 void fuse_conn_init(struct fuse_conn *fc)
521 memset(fc, 0, sizeof(*fc));
522 spin_lock_init(&fc->lock);
523 mutex_init(&fc->inst_mutex);
524 init_rwsem(&fc->killsb);
525 atomic_set(&fc->count, 1);
526 init_waitqueue_head(&fc->waitq);
527 init_waitqueue_head(&fc->blocked_waitq);
528 init_waitqueue_head(&fc->reserved_req_waitq);
529 INIT_LIST_HEAD(&fc->pending);
530 INIT_LIST_HEAD(&fc->processing);
531 INIT_LIST_HEAD(&fc->io);
532 INIT_LIST_HEAD(&fc->interrupts);
533 INIT_LIST_HEAD(&fc->bg_queue);
534 INIT_LIST_HEAD(&fc->entry);
535 fc->forget_list_tail = &fc->forget_list_head;
536 atomic_set(&fc->num_waiting, 0);
537 fc->max_background = FUSE_DEFAULT_MAX_BACKGROUND;
538 fc->congestion_threshold = FUSE_DEFAULT_CONGESTION_THRESHOLD;
540 fc->polled_files = RB_ROOT;
543 fc->attr_version = 1;
544 get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key));
546 EXPORT_SYMBOL_GPL(fuse_conn_init);
548 void fuse_conn_put(struct fuse_conn *fc)
550 if (atomic_dec_and_test(&fc->count)) {
552 fuse_request_free(fc->destroy_req);
553 mutex_destroy(&fc->inst_mutex);
557 EXPORT_SYMBOL_GPL(fuse_conn_put);
559 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc)
561 atomic_inc(&fc->count);
564 EXPORT_SYMBOL_GPL(fuse_conn_get);
566 static struct inode *fuse_get_root_inode(struct super_block *sb, unsigned mode)
568 struct fuse_attr attr;
569 memset(&attr, 0, sizeof(attr));
572 attr.ino = FUSE_ROOT_ID;
574 return fuse_iget(sb, 1, 0, &attr, 0, 0);
577 struct fuse_inode_handle {
582 static struct dentry *fuse_get_dentry(struct super_block *sb,
583 struct fuse_inode_handle *handle)
585 struct fuse_conn *fc = get_fuse_conn_super(sb);
587 struct dentry *entry;
590 if (handle->nodeid == 0)
593 inode = ilookup5(sb, handle->nodeid, fuse_inode_eq, &handle->nodeid);
595 struct fuse_entry_out outarg;
598 if (!fc->export_support)
603 err = fuse_lookup_name(sb, handle->nodeid, &name, &outarg,
605 if (err && err != -ENOENT)
612 if (get_node_id(inode) != handle->nodeid)
616 if (inode->i_generation != handle->generation)
619 entry = d_obtain_alias(inode);
620 if (!IS_ERR(entry) && get_node_id(inode) != FUSE_ROOT_ID)
621 fuse_invalidate_entry_cache(entry);
631 static int fuse_encode_fh(struct dentry *dentry, u32 *fh, int *max_len,
634 struct inode *inode = dentry->d_inode;
635 bool encode_parent = connectable && !S_ISDIR(inode->i_mode);
636 int len = encode_parent ? 6 : 3;
640 if (*max_len < len) {
645 nodeid = get_fuse_inode(inode)->nodeid;
646 generation = inode->i_generation;
648 fh[0] = (u32)(nodeid >> 32);
649 fh[1] = (u32)(nodeid & 0xffffffff);
653 struct inode *parent;
655 spin_lock(&dentry->d_lock);
656 parent = dentry->d_parent->d_inode;
657 nodeid = get_fuse_inode(parent)->nodeid;
658 generation = parent->i_generation;
659 spin_unlock(&dentry->d_lock);
661 fh[3] = (u32)(nodeid >> 32);
662 fh[4] = (u32)(nodeid & 0xffffffff);
667 return encode_parent ? 0x82 : 0x81;
670 static struct dentry *fuse_fh_to_dentry(struct super_block *sb,
671 struct fid *fid, int fh_len, int fh_type)
673 struct fuse_inode_handle handle;
675 if ((fh_type != 0x81 && fh_type != 0x82) || fh_len < 3)
678 handle.nodeid = (u64) fid->raw[0] << 32;
679 handle.nodeid |= (u64) fid->raw[1];
680 handle.generation = fid->raw[2];
681 return fuse_get_dentry(sb, &handle);
684 static struct dentry *fuse_fh_to_parent(struct super_block *sb,
685 struct fid *fid, int fh_len, int fh_type)
687 struct fuse_inode_handle parent;
689 if (fh_type != 0x82 || fh_len < 6)
692 parent.nodeid = (u64) fid->raw[3] << 32;
693 parent.nodeid |= (u64) fid->raw[4];
694 parent.generation = fid->raw[5];
695 return fuse_get_dentry(sb, &parent);
698 static struct dentry *fuse_get_parent(struct dentry *child)
700 struct inode *child_inode = child->d_inode;
701 struct fuse_conn *fc = get_fuse_conn(child_inode);
703 struct dentry *parent;
704 struct fuse_entry_out outarg;
708 if (!fc->export_support)
709 return ERR_PTR(-ESTALE);
713 err = fuse_lookup_name(child_inode->i_sb, get_node_id(child_inode),
714 &name, &outarg, &inode);
717 return ERR_PTR(-ESTALE);
721 parent = d_obtain_alias(inode);
722 if (!IS_ERR(parent) && get_node_id(inode) != FUSE_ROOT_ID)
723 fuse_invalidate_entry_cache(parent);
728 static const struct export_operations fuse_export_operations = {
729 .fh_to_dentry = fuse_fh_to_dentry,
730 .fh_to_parent = fuse_fh_to_parent,
731 .encode_fh = fuse_encode_fh,
732 .get_parent = fuse_get_parent,
735 static const struct super_operations fuse_super_operations = {
736 .alloc_inode = fuse_alloc_inode,
737 .destroy_inode = fuse_destroy_inode,
738 .evict_inode = fuse_evict_inode,
739 .drop_inode = generic_delete_inode,
740 .remount_fs = fuse_remount_fs,
741 .put_super = fuse_put_super,
742 .umount_begin = fuse_umount_begin,
743 .statfs = fuse_statfs,
744 .show_options = fuse_show_options,
747 static void sanitize_global_limit(unsigned *limit)
750 *limit = ((num_physpages << PAGE_SHIFT) >> 13) /
751 sizeof(struct fuse_req);
753 if (*limit >= 1 << 16)
754 *limit = (1 << 16) - 1;
757 static int set_global_limit(const char *val, struct kernel_param *kp)
761 rv = param_set_uint(val, kp);
765 sanitize_global_limit((unsigned *)kp->arg);
770 static void process_init_limits(struct fuse_conn *fc, struct fuse_init_out *arg)
772 int cap_sys_admin = capable(CAP_SYS_ADMIN);
777 sanitize_global_limit(&max_user_bgreq);
778 sanitize_global_limit(&max_user_congthresh);
780 if (arg->max_background) {
781 fc->max_background = arg->max_background;
783 if (!cap_sys_admin && fc->max_background > max_user_bgreq)
784 fc->max_background = max_user_bgreq;
786 if (arg->congestion_threshold) {
787 fc->congestion_threshold = arg->congestion_threshold;
789 if (!cap_sys_admin &&
790 fc->congestion_threshold > max_user_congthresh)
791 fc->congestion_threshold = max_user_congthresh;
795 static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
797 struct fuse_init_out *arg = &req->misc.init_out;
799 if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION)
802 unsigned long ra_pages;
804 process_init_limits(fc, arg);
806 if (arg->minor >= 6) {
807 ra_pages = arg->max_readahead / PAGE_CACHE_SIZE;
808 if (arg->flags & FUSE_ASYNC_READ)
810 if (!(arg->flags & FUSE_POSIX_LOCKS))
812 if (arg->minor >= 17) {
813 if (!(arg->flags & FUSE_FLOCK_LOCKS))
816 if (!(arg->flags & FUSE_POSIX_LOCKS))
819 if (arg->flags & FUSE_ATOMIC_O_TRUNC)
820 fc->atomic_o_trunc = 1;
821 if (arg->minor >= 9) {
822 /* LOOKUP has dependency on proto version */
823 if (arg->flags & FUSE_EXPORT_SUPPORT)
824 fc->export_support = 1;
826 if (arg->flags & FUSE_BIG_WRITES)
828 if (arg->flags & FUSE_DONT_MASK)
831 ra_pages = fc->max_read / PAGE_CACHE_SIZE;
836 fc->bdi.ra_pages = min(fc->bdi.ra_pages, ra_pages);
837 fc->minor = arg->minor;
838 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
839 fc->max_write = max_t(unsigned, 4096, fc->max_write);
843 wake_up_all(&fc->blocked_waitq);
846 static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req)
848 struct fuse_init_in *arg = &req->misc.init_in;
850 arg->major = FUSE_KERNEL_VERSION;
851 arg->minor = FUSE_KERNEL_MINOR_VERSION;
852 arg->max_readahead = fc->bdi.ra_pages * PAGE_CACHE_SIZE;
853 arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_ATOMIC_O_TRUNC |
854 FUSE_EXPORT_SUPPORT | FUSE_BIG_WRITES | FUSE_DONT_MASK |
856 req->in.h.opcode = FUSE_INIT;
858 req->in.args[0].size = sizeof(*arg);
859 req->in.args[0].value = arg;
860 req->out.numargs = 1;
861 /* Variable length argument used for backward compatibility
862 with interface version < 7.5. Rest of init_out is zeroed
863 by do_get_request(), so a short reply is not a problem */
865 req->out.args[0].size = sizeof(struct fuse_init_out);
866 req->out.args[0].value = &req->misc.init_out;
867 req->end = process_init_reply;
868 fuse_request_send_background(fc, req);
871 static void fuse_free_conn(struct fuse_conn *fc)
876 static int fuse_bdi_init(struct fuse_conn *fc, struct super_block *sb)
880 fc->bdi.name = "fuse";
881 fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
882 /* fuse does it's own writeback accounting */
883 fc->bdi.capabilities = BDI_CAP_NO_ACCT_WB;
885 err = bdi_init(&fc->bdi);
889 fc->bdi_initialized = 1;
892 err = bdi_register(&fc->bdi, NULL, "%u:%u-fuseblk",
893 MAJOR(fc->dev), MINOR(fc->dev));
895 err = bdi_register_dev(&fc->bdi, fc->dev);
902 * For a single fuse filesystem use max 1% of dirty +
903 * writeback threshold.
905 * This gives about 1M of write buffer for memory maps on a
906 * machine with 1G and 10% dirty_ratio, which should be more
909 * Privileged users can raise it by writing to
911 * /sys/class/bdi/<bdi>/max_ratio
913 bdi_set_max_ratio(&fc->bdi, 1);
918 static int fuse_fill_super(struct super_block *sb, void *data, int silent)
920 struct fuse_conn *fc;
922 struct fuse_mount_data d;
924 struct dentry *root_dentry;
925 struct fuse_req *init_req;
927 int is_bdev = sb->s_bdev != NULL;
930 if (sb->s_flags & MS_MANDLOCK)
933 sb->s_flags &= ~MS_NOSEC;
935 if (!parse_fuse_opt((char *) data, &d, is_bdev))
941 if (!sb_set_blocksize(sb, d.blksize))
945 sb->s_blocksize = PAGE_CACHE_SIZE;
946 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
948 sb->s_magic = FUSE_SUPER_MAGIC;
949 sb->s_op = &fuse_super_operations;
950 sb->s_maxbytes = MAX_LFS_FILESIZE;
951 sb->s_export_op = &fuse_export_operations;
958 if (file->f_op != &fuse_dev_operations)
961 fc = kmalloc(sizeof(*fc), GFP_KERNEL);
970 err = fuse_bdi_init(fc, sb);
974 sb->s_bdi = &fc->bdi;
976 /* Handle umasking inside the fuse code */
977 if (sb->s_flags & MS_POSIXACL)
979 sb->s_flags |= MS_POSIXACL;
981 fc->release = fuse_free_conn;
983 fc->user_id = d.user_id;
984 fc->group_id = d.group_id;
985 fc->max_read = max_t(unsigned, 4096, d.max_read);
987 /* Used by get_root_inode() */
991 root = fuse_get_root_inode(sb, d.rootmode);
995 root_dentry = d_alloc_root(root);
1000 /* only now - we want root dentry with NULL ->d_op */
1001 sb->s_d_op = &fuse_dentry_operations;
1003 init_req = fuse_request_alloc();
1008 fc->destroy_req = fuse_request_alloc();
1009 if (!fc->destroy_req)
1010 goto err_free_init_req;
1013 mutex_lock(&fuse_mutex);
1015 if (file->private_data)
1018 err = fuse_ctl_add_conn(fc);
1022 list_add_tail(&fc->entry, &fuse_conn_list);
1023 sb->s_root = root_dentry;
1025 file->private_data = fuse_conn_get(fc);
1026 mutex_unlock(&fuse_mutex);
1028 * atomic_dec_and_test() in fput() provides the necessary
1029 * memory barrier for file->private_data to be visible on all
1034 fuse_send_init(fc, init_req);
1039 mutex_unlock(&fuse_mutex);
1041 fuse_request_free(init_req);
1045 fuse_bdi_destroy(fc);
1053 static struct dentry *fuse_mount(struct file_system_type *fs_type,
1054 int flags, const char *dev_name,
1057 return mount_nodev(fs_type, flags, raw_data, fuse_fill_super);
1060 static void fuse_kill_sb_anon(struct super_block *sb)
1062 struct fuse_conn *fc = get_fuse_conn_super(sb);
1065 down_write(&fc->killsb);
1067 up_write(&fc->killsb);
1070 kill_anon_super(sb);
1073 static struct file_system_type fuse_fs_type = {
1074 .owner = THIS_MODULE,
1076 .fs_flags = FS_HAS_SUBTYPE,
1077 .mount = fuse_mount,
1078 .kill_sb = fuse_kill_sb_anon,
1082 static struct dentry *fuse_mount_blk(struct file_system_type *fs_type,
1083 int flags, const char *dev_name,
1086 return mount_bdev(fs_type, flags, dev_name, raw_data, fuse_fill_super);
1089 static void fuse_kill_sb_blk(struct super_block *sb)
1091 struct fuse_conn *fc = get_fuse_conn_super(sb);
1094 down_write(&fc->killsb);
1096 up_write(&fc->killsb);
1099 kill_block_super(sb);
1102 static struct file_system_type fuseblk_fs_type = {
1103 .owner = THIS_MODULE,
1105 .mount = fuse_mount_blk,
1106 .kill_sb = fuse_kill_sb_blk,
1107 .fs_flags = FS_REQUIRES_DEV | FS_HAS_SUBTYPE,
1110 static inline int register_fuseblk(void)
1112 return register_filesystem(&fuseblk_fs_type);
1115 static inline void unregister_fuseblk(void)
1117 unregister_filesystem(&fuseblk_fs_type);
1120 static inline int register_fuseblk(void)
1125 static inline void unregister_fuseblk(void)
1130 static void fuse_inode_init_once(void *foo)
1132 struct inode *inode = foo;
1134 inode_init_once(inode);
1137 static int __init fuse_fs_init(void)
1141 err = register_filesystem(&fuse_fs_type);
1145 err = register_fuseblk();
1149 fuse_inode_cachep = kmem_cache_create("fuse_inode",
1150 sizeof(struct fuse_inode),
1151 0, SLAB_HWCACHE_ALIGN,
1152 fuse_inode_init_once);
1154 if (!fuse_inode_cachep)
1160 unregister_fuseblk();
1162 unregister_filesystem(&fuse_fs_type);
1167 static void fuse_fs_cleanup(void)
1169 unregister_filesystem(&fuse_fs_type);
1170 unregister_fuseblk();
1171 kmem_cache_destroy(fuse_inode_cachep);
1174 static struct kobject *fuse_kobj;
1175 static struct kobject *connections_kobj;
1177 static int fuse_sysfs_init(void)
1181 fuse_kobj = kobject_create_and_add("fuse", fs_kobj);
1187 connections_kobj = kobject_create_and_add("connections", fuse_kobj);
1188 if (!connections_kobj) {
1190 goto out_fuse_unregister;
1195 out_fuse_unregister:
1196 kobject_put(fuse_kobj);
1201 static void fuse_sysfs_cleanup(void)
1203 kobject_put(connections_kobj);
1204 kobject_put(fuse_kobj);
1207 static int __init fuse_init(void)
1211 printk(KERN_INFO "fuse init (API version %i.%i)\n",
1212 FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
1214 INIT_LIST_HEAD(&fuse_conn_list);
1215 res = fuse_fs_init();
1219 res = fuse_dev_init();
1221 goto err_fs_cleanup;
1223 res = fuse_sysfs_init();
1225 goto err_dev_cleanup;
1227 res = fuse_ctl_init();
1229 goto err_sysfs_cleanup;
1231 sanitize_global_limit(&max_user_bgreq);
1232 sanitize_global_limit(&max_user_congthresh);
1237 fuse_sysfs_cleanup();
1246 static void __exit fuse_exit(void)
1248 printk(KERN_DEBUG "fuse exit\n");
1251 fuse_sysfs_cleanup();
1256 module_init(fuse_init);
1257 module_exit(fuse_exit);