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);
95 INIT_LIST_HEAD(&fi->write_files);
96 INIT_LIST_HEAD(&fi->queued_writes);
97 INIT_LIST_HEAD(&fi->writepages);
98 init_waitqueue_head(&fi->page_waitq);
99 fi->forget = fuse_alloc_forget();
101 kmem_cache_free(fuse_inode_cachep, inode);
108 static void fuse_i_callback(struct rcu_head *head)
110 struct inode *inode = container_of(head, struct inode, i_rcu);
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);
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)
144 * ino_t is 32-bits on 32-bit arch. We have to squash the 64-bit value down
145 * so that it will fit.
147 static ino_t fuse_squash_ino(u64 ino64)
149 ino_t ino = (ino_t) ino64;
150 if (sizeof(ino_t) < sizeof(u64))
151 ino ^= ino64 >> (sizeof(u64) - sizeof(ino_t)) * 8;
155 void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
158 struct fuse_conn *fc = get_fuse_conn(inode);
159 struct fuse_inode *fi = get_fuse_inode(inode);
161 fi->attr_version = ++fc->attr_version;
162 fi->i_time = attr_valid;
164 inode->i_ino = fuse_squash_ino(attr->ino);
165 inode->i_mode = (inode->i_mode & S_IFMT) | (attr->mode & 07777);
166 set_nlink(inode, attr->nlink);
167 inode->i_uid = attr->uid;
168 inode->i_gid = attr->gid;
169 inode->i_blocks = attr->blocks;
170 inode->i_atime.tv_sec = attr->atime;
171 inode->i_atime.tv_nsec = attr->atimensec;
172 inode->i_mtime.tv_sec = attr->mtime;
173 inode->i_mtime.tv_nsec = attr->mtimensec;
174 inode->i_ctime.tv_sec = attr->ctime;
175 inode->i_ctime.tv_nsec = attr->ctimensec;
177 if (attr->blksize != 0)
178 inode->i_blkbits = ilog2(attr->blksize);
180 inode->i_blkbits = inode->i_sb->s_blocksize_bits;
183 * Don't set the sticky bit in i_mode, unless we want the VFS
184 * to check permissions. This prevents failures due to the
185 * check in may_delete().
187 fi->orig_i_mode = inode->i_mode;
188 if (!(fc->flags & FUSE_DEFAULT_PERMISSIONS))
189 inode->i_mode &= ~S_ISVTX;
191 fi->orig_ino = attr->ino;
194 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
195 u64 attr_valid, u64 attr_version)
197 struct fuse_conn *fc = get_fuse_conn(inode);
198 struct fuse_inode *fi = get_fuse_inode(inode);
200 struct timespec old_mtime;
202 spin_lock(&fc->lock);
203 if (attr_version != 0 && fi->attr_version > attr_version) {
204 spin_unlock(&fc->lock);
208 old_mtime = inode->i_mtime;
209 fuse_change_attributes_common(inode, attr, attr_valid);
211 oldsize = inode->i_size;
212 i_size_write(inode, attr->size);
213 spin_unlock(&fc->lock);
215 if (S_ISREG(inode->i_mode)) {
218 if (oldsize != attr->size) {
219 truncate_pagecache(inode, oldsize, attr->size);
221 } else if (fc->auto_inval_data) {
222 struct timespec new_mtime = {
223 .tv_sec = attr->mtime,
224 .tv_nsec = attr->mtimensec,
228 * Auto inval mode also checks and invalidates if mtime
231 if (!timespec_equal(&old_mtime, &new_mtime))
236 invalidate_inode_pages2(inode->i_mapping);
240 static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
242 inode->i_mode = attr->mode & S_IFMT;
243 inode->i_size = attr->size;
244 if (S_ISREG(inode->i_mode)) {
245 fuse_init_common(inode);
246 fuse_init_file_inode(inode);
247 } else if (S_ISDIR(inode->i_mode))
248 fuse_init_dir(inode);
249 else if (S_ISLNK(inode->i_mode))
250 fuse_init_symlink(inode);
251 else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
252 S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
253 fuse_init_common(inode);
254 init_special_inode(inode, inode->i_mode,
255 new_decode_dev(attr->rdev));
260 int fuse_inode_eq(struct inode *inode, void *_nodeidp)
262 u64 nodeid = *(u64 *) _nodeidp;
263 if (get_node_id(inode) == nodeid)
269 static int fuse_inode_set(struct inode *inode, void *_nodeidp)
271 u64 nodeid = *(u64 *) _nodeidp;
272 get_fuse_inode(inode)->nodeid = nodeid;
276 struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
277 int generation, struct fuse_attr *attr,
278 u64 attr_valid, u64 attr_version)
281 struct fuse_inode *fi;
282 struct fuse_conn *fc = get_fuse_conn_super(sb);
285 inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid);
289 if ((inode->i_state & I_NEW)) {
290 inode->i_flags |= S_NOATIME|S_NOCMTIME;
291 inode->i_generation = generation;
292 inode->i_data.backing_dev_info = &fc->bdi;
293 fuse_init_inode(inode, attr);
294 unlock_new_inode(inode);
295 } else if ((inode->i_mode ^ attr->mode) & S_IFMT) {
296 /* Inode has changed type, any I/O on the old should fail */
297 make_bad_inode(inode);
302 fi = get_fuse_inode(inode);
303 spin_lock(&fc->lock);
305 spin_unlock(&fc->lock);
306 fuse_change_attributes(inode, attr, attr_valid, attr_version);
311 int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid,
312 loff_t offset, loff_t len)
318 inode = ilookup5(sb, nodeid, fuse_inode_eq, &nodeid);
322 fuse_invalidate_attr(inode);
324 pg_start = offset >> PAGE_CACHE_SHIFT;
328 pg_end = (offset + len - 1) >> PAGE_CACHE_SHIFT;
329 invalidate_inode_pages2_range(inode->i_mapping,
336 static void fuse_umount_begin(struct super_block *sb)
338 fuse_abort_conn(get_fuse_conn_super(sb));
341 static void fuse_send_destroy(struct fuse_conn *fc)
343 struct fuse_req *req = fc->destroy_req;
344 if (req && fc->conn_init) {
345 fc->destroy_req = NULL;
346 req->in.h.opcode = FUSE_DESTROY;
348 fuse_request_send(fc, req);
349 fuse_put_request(fc, req);
353 static void fuse_bdi_destroy(struct fuse_conn *fc)
355 if (fc->bdi_initialized)
356 bdi_destroy(&fc->bdi);
359 void fuse_conn_kill(struct fuse_conn *fc)
361 spin_lock(&fc->lock);
364 spin_unlock(&fc->lock);
365 /* Flush all readers on this fs */
366 kill_fasync(&fc->fasync, SIGIO, POLL_IN);
367 wake_up_all(&fc->waitq);
368 wake_up_all(&fc->blocked_waitq);
369 wake_up_all(&fc->reserved_req_waitq);
370 mutex_lock(&fuse_mutex);
371 list_del(&fc->entry);
372 fuse_ctl_remove_conn(fc);
373 mutex_unlock(&fuse_mutex);
374 fuse_bdi_destroy(fc);
376 EXPORT_SYMBOL_GPL(fuse_conn_kill);
378 static void fuse_put_super(struct super_block *sb)
380 struct fuse_conn *fc = get_fuse_conn_super(sb);
382 fuse_send_destroy(fc);
387 static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
389 stbuf->f_type = FUSE_SUPER_MAGIC;
390 stbuf->f_bsize = attr->bsize;
391 stbuf->f_frsize = attr->frsize;
392 stbuf->f_blocks = attr->blocks;
393 stbuf->f_bfree = attr->bfree;
394 stbuf->f_bavail = attr->bavail;
395 stbuf->f_files = attr->files;
396 stbuf->f_ffree = attr->ffree;
397 stbuf->f_namelen = attr->namelen;
398 /* fsid is left zero */
401 static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf)
403 struct super_block *sb = dentry->d_sb;
404 struct fuse_conn *fc = get_fuse_conn_super(sb);
405 struct fuse_req *req;
406 struct fuse_statfs_out outarg;
409 if (!fuse_allow_task(fc, current)) {
410 buf->f_type = FUSE_SUPER_MAGIC;
414 req = fuse_get_req(fc);
418 memset(&outarg, 0, sizeof(outarg));
420 req->in.h.opcode = FUSE_STATFS;
421 req->in.h.nodeid = get_node_id(dentry->d_inode);
422 req->out.numargs = 1;
423 req->out.args[0].size =
424 fc->minor < 4 ? FUSE_COMPAT_STATFS_SIZE : sizeof(outarg);
425 req->out.args[0].value = &outarg;
426 fuse_request_send(fc, req);
427 err = req->out.h.error;
429 convert_fuse_statfs(buf, &outarg.st);
430 fuse_put_request(fc, req);
439 OPT_DEFAULT_PERMISSIONS,
446 static const match_table_t tokens = {
448 {OPT_ROOTMODE, "rootmode=%o"},
449 {OPT_USER_ID, "user_id=%u"},
450 {OPT_GROUP_ID, "group_id=%u"},
451 {OPT_DEFAULT_PERMISSIONS, "default_permissions"},
452 {OPT_ALLOW_OTHER, "allow_other"},
453 {OPT_MAX_READ, "max_read=%u"},
454 {OPT_BLKSIZE, "blksize=%u"},
458 static int parse_fuse_opt(char *opt, struct fuse_mount_data *d, int is_bdev)
461 memset(d, 0, sizeof(struct fuse_mount_data));
463 d->blksize = FUSE_DEFAULT_BLKSIZE;
465 while ((p = strsep(&opt, ",")) != NULL) {
468 substring_t args[MAX_OPT_ARGS];
472 token = match_token(p, tokens, args);
475 if (match_int(&args[0], &value))
482 if (match_octal(&args[0], &value))
484 if (!fuse_valid_type(value))
487 d->rootmode_present = 1;
491 if (match_int(&args[0], &value))
494 d->user_id_present = 1;
498 if (match_int(&args[0], &value))
501 d->group_id_present = 1;
504 case OPT_DEFAULT_PERMISSIONS:
505 d->flags |= FUSE_DEFAULT_PERMISSIONS;
508 case OPT_ALLOW_OTHER:
509 d->flags |= FUSE_ALLOW_OTHER;
513 if (match_int(&args[0], &value))
519 if (!is_bdev || match_int(&args[0], &value))
529 if (!d->fd_present || !d->rootmode_present ||
530 !d->user_id_present || !d->group_id_present)
536 static int fuse_show_options(struct seq_file *m, struct dentry *root)
538 struct super_block *sb = root->d_sb;
539 struct fuse_conn *fc = get_fuse_conn_super(sb);
541 seq_printf(m, ",user_id=%u", fc->user_id);
542 seq_printf(m, ",group_id=%u", fc->group_id);
543 if (fc->flags & FUSE_DEFAULT_PERMISSIONS)
544 seq_puts(m, ",default_permissions");
545 if (fc->flags & FUSE_ALLOW_OTHER)
546 seq_puts(m, ",allow_other");
547 if (fc->max_read != ~0)
548 seq_printf(m, ",max_read=%u", fc->max_read);
549 if (sb->s_bdev && sb->s_blocksize != FUSE_DEFAULT_BLKSIZE)
550 seq_printf(m, ",blksize=%lu", sb->s_blocksize);
554 void fuse_conn_init(struct fuse_conn *fc)
556 memset(fc, 0, sizeof(*fc));
557 spin_lock_init(&fc->lock);
558 mutex_init(&fc->inst_mutex);
559 init_rwsem(&fc->killsb);
560 atomic_set(&fc->count, 1);
561 init_waitqueue_head(&fc->waitq);
562 init_waitqueue_head(&fc->blocked_waitq);
563 init_waitqueue_head(&fc->reserved_req_waitq);
564 INIT_LIST_HEAD(&fc->pending);
565 INIT_LIST_HEAD(&fc->processing);
566 INIT_LIST_HEAD(&fc->io);
567 INIT_LIST_HEAD(&fc->interrupts);
568 INIT_LIST_HEAD(&fc->bg_queue);
569 INIT_LIST_HEAD(&fc->entry);
570 fc->forget_list_tail = &fc->forget_list_head;
571 atomic_set(&fc->num_waiting, 0);
572 fc->max_background = FUSE_DEFAULT_MAX_BACKGROUND;
573 fc->congestion_threshold = FUSE_DEFAULT_CONGESTION_THRESHOLD;
575 fc->polled_files = RB_ROOT;
578 fc->attr_version = 1;
579 get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key));
581 EXPORT_SYMBOL_GPL(fuse_conn_init);
583 void fuse_conn_put(struct fuse_conn *fc)
585 if (atomic_dec_and_test(&fc->count)) {
587 fuse_request_free(fc->destroy_req);
588 mutex_destroy(&fc->inst_mutex);
592 EXPORT_SYMBOL_GPL(fuse_conn_put);
594 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc)
596 atomic_inc(&fc->count);
599 EXPORT_SYMBOL_GPL(fuse_conn_get);
601 static struct inode *fuse_get_root_inode(struct super_block *sb, unsigned mode)
603 struct fuse_attr attr;
604 memset(&attr, 0, sizeof(attr));
607 attr.ino = FUSE_ROOT_ID;
609 return fuse_iget(sb, 1, 0, &attr, 0, 0);
612 struct fuse_inode_handle {
617 static struct dentry *fuse_get_dentry(struct super_block *sb,
618 struct fuse_inode_handle *handle)
620 struct fuse_conn *fc = get_fuse_conn_super(sb);
622 struct dentry *entry;
625 if (handle->nodeid == 0)
628 inode = ilookup5(sb, handle->nodeid, fuse_inode_eq, &handle->nodeid);
630 struct fuse_entry_out outarg;
633 if (!fc->export_support)
638 err = fuse_lookup_name(sb, handle->nodeid, &name, &outarg,
640 if (err && err != -ENOENT)
647 if (get_node_id(inode) != handle->nodeid)
651 if (inode->i_generation != handle->generation)
654 entry = d_obtain_alias(inode);
655 if (!IS_ERR(entry) && get_node_id(inode) != FUSE_ROOT_ID)
656 fuse_invalidate_entry_cache(entry);
666 static int fuse_encode_fh(struct inode *inode, u32 *fh, int *max_len,
667 struct inode *parent)
669 int len = parent ? 6 : 3;
673 if (*max_len < len) {
678 nodeid = get_fuse_inode(inode)->nodeid;
679 generation = inode->i_generation;
681 fh[0] = (u32)(nodeid >> 32);
682 fh[1] = (u32)(nodeid & 0xffffffff);
686 nodeid = get_fuse_inode(parent)->nodeid;
687 generation = parent->i_generation;
689 fh[3] = (u32)(nodeid >> 32);
690 fh[4] = (u32)(nodeid & 0xffffffff);
695 return parent ? 0x82 : 0x81;
698 static struct dentry *fuse_fh_to_dentry(struct super_block *sb,
699 struct fid *fid, int fh_len, int fh_type)
701 struct fuse_inode_handle handle;
703 if ((fh_type != 0x81 && fh_type != 0x82) || fh_len < 3)
706 handle.nodeid = (u64) fid->raw[0] << 32;
707 handle.nodeid |= (u64) fid->raw[1];
708 handle.generation = fid->raw[2];
709 return fuse_get_dentry(sb, &handle);
712 static struct dentry *fuse_fh_to_parent(struct super_block *sb,
713 struct fid *fid, int fh_len, int fh_type)
715 struct fuse_inode_handle parent;
717 if (fh_type != 0x82 || fh_len < 6)
720 parent.nodeid = (u64) fid->raw[3] << 32;
721 parent.nodeid |= (u64) fid->raw[4];
722 parent.generation = fid->raw[5];
723 return fuse_get_dentry(sb, &parent);
726 static struct dentry *fuse_get_parent(struct dentry *child)
728 struct inode *child_inode = child->d_inode;
729 struct fuse_conn *fc = get_fuse_conn(child_inode);
731 struct dentry *parent;
732 struct fuse_entry_out outarg;
736 if (!fc->export_support)
737 return ERR_PTR(-ESTALE);
741 err = fuse_lookup_name(child_inode->i_sb, get_node_id(child_inode),
742 &name, &outarg, &inode);
745 return ERR_PTR(-ESTALE);
749 parent = d_obtain_alias(inode);
750 if (!IS_ERR(parent) && get_node_id(inode) != FUSE_ROOT_ID)
751 fuse_invalidate_entry_cache(parent);
756 static const struct export_operations fuse_export_operations = {
757 .fh_to_dentry = fuse_fh_to_dentry,
758 .fh_to_parent = fuse_fh_to_parent,
759 .encode_fh = fuse_encode_fh,
760 .get_parent = fuse_get_parent,
763 static const struct super_operations fuse_super_operations = {
764 .alloc_inode = fuse_alloc_inode,
765 .destroy_inode = fuse_destroy_inode,
766 .evict_inode = fuse_evict_inode,
767 .drop_inode = generic_delete_inode,
768 .remount_fs = fuse_remount_fs,
769 .put_super = fuse_put_super,
770 .umount_begin = fuse_umount_begin,
771 .statfs = fuse_statfs,
772 .show_options = fuse_show_options,
775 static void sanitize_global_limit(unsigned *limit)
778 *limit = ((num_physpages << PAGE_SHIFT) >> 13) /
779 sizeof(struct fuse_req);
781 if (*limit >= 1 << 16)
782 *limit = (1 << 16) - 1;
785 static int set_global_limit(const char *val, struct kernel_param *kp)
789 rv = param_set_uint(val, kp);
793 sanitize_global_limit((unsigned *)kp->arg);
798 static void process_init_limits(struct fuse_conn *fc, struct fuse_init_out *arg)
800 int cap_sys_admin = capable(CAP_SYS_ADMIN);
805 sanitize_global_limit(&max_user_bgreq);
806 sanitize_global_limit(&max_user_congthresh);
808 if (arg->max_background) {
809 fc->max_background = arg->max_background;
811 if (!cap_sys_admin && fc->max_background > max_user_bgreq)
812 fc->max_background = max_user_bgreq;
814 if (arg->congestion_threshold) {
815 fc->congestion_threshold = arg->congestion_threshold;
817 if (!cap_sys_admin &&
818 fc->congestion_threshold > max_user_congthresh)
819 fc->congestion_threshold = max_user_congthresh;
823 static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
825 struct fuse_init_out *arg = &req->misc.init_out;
827 if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION)
830 unsigned long ra_pages;
832 process_init_limits(fc, arg);
834 if (arg->minor >= 6) {
835 ra_pages = arg->max_readahead / PAGE_CACHE_SIZE;
836 if (arg->flags & FUSE_ASYNC_READ)
838 if (!(arg->flags & FUSE_POSIX_LOCKS))
840 if (arg->minor >= 17) {
841 if (!(arg->flags & FUSE_FLOCK_LOCKS))
844 if (!(arg->flags & FUSE_POSIX_LOCKS))
847 if (arg->flags & FUSE_ATOMIC_O_TRUNC)
848 fc->atomic_o_trunc = 1;
849 if (arg->minor >= 9) {
850 /* LOOKUP has dependency on proto version */
851 if (arg->flags & FUSE_EXPORT_SUPPORT)
852 fc->export_support = 1;
854 if (arg->flags & FUSE_BIG_WRITES)
856 if (arg->flags & FUSE_DONT_MASK)
858 if (arg->flags & FUSE_AUTO_INVAL_DATA)
859 fc->auto_inval_data = 1;
861 ra_pages = fc->max_read / PAGE_CACHE_SIZE;
866 fc->bdi.ra_pages = min(fc->bdi.ra_pages, ra_pages);
867 fc->minor = arg->minor;
868 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
869 fc->max_write = max_t(unsigned, 4096, fc->max_write);
873 wake_up_all(&fc->blocked_waitq);
876 static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req)
878 struct fuse_init_in *arg = &req->misc.init_in;
880 arg->major = FUSE_KERNEL_VERSION;
881 arg->minor = FUSE_KERNEL_MINOR_VERSION;
882 arg->max_readahead = fc->bdi.ra_pages * PAGE_CACHE_SIZE;
883 arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_ATOMIC_O_TRUNC |
884 FUSE_EXPORT_SUPPORT | FUSE_BIG_WRITES | FUSE_DONT_MASK |
885 FUSE_SPLICE_WRITE | FUSE_SPLICE_MOVE | FUSE_SPLICE_READ |
886 FUSE_FLOCK_LOCKS | FUSE_IOCTL_DIR | FUSE_AUTO_INVAL_DATA;
887 req->in.h.opcode = FUSE_INIT;
889 req->in.args[0].size = sizeof(*arg);
890 req->in.args[0].value = arg;
891 req->out.numargs = 1;
892 /* Variable length argument used for backward compatibility
893 with interface version < 7.5. Rest of init_out is zeroed
894 by do_get_request(), so a short reply is not a problem */
896 req->out.args[0].size = sizeof(struct fuse_init_out);
897 req->out.args[0].value = &req->misc.init_out;
898 req->end = process_init_reply;
899 fuse_request_send_background(fc, req);
902 static void fuse_free_conn(struct fuse_conn *fc)
907 static int fuse_bdi_init(struct fuse_conn *fc, struct super_block *sb)
911 fc->bdi.name = "fuse";
912 fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
913 /* fuse does it's own writeback accounting */
914 fc->bdi.capabilities = BDI_CAP_NO_ACCT_WB;
916 err = bdi_init(&fc->bdi);
920 fc->bdi_initialized = 1;
923 err = bdi_register(&fc->bdi, NULL, "%u:%u-fuseblk",
924 MAJOR(fc->dev), MINOR(fc->dev));
926 err = bdi_register_dev(&fc->bdi, fc->dev);
933 * For a single fuse filesystem use max 1% of dirty +
934 * writeback threshold.
936 * This gives about 1M of write buffer for memory maps on a
937 * machine with 1G and 10% dirty_ratio, which should be more
940 * Privileged users can raise it by writing to
942 * /sys/class/bdi/<bdi>/max_ratio
944 bdi_set_max_ratio(&fc->bdi, 1);
949 static int fuse_fill_super(struct super_block *sb, void *data, int silent)
951 struct fuse_conn *fc;
953 struct fuse_mount_data d;
955 struct dentry *root_dentry;
956 struct fuse_req *init_req;
958 int is_bdev = sb->s_bdev != NULL;
961 if (sb->s_flags & MS_MANDLOCK)
964 sb->s_flags &= ~MS_NOSEC;
966 if (!parse_fuse_opt((char *) data, &d, is_bdev))
972 if (!sb_set_blocksize(sb, d.blksize))
976 sb->s_blocksize = PAGE_CACHE_SIZE;
977 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
979 sb->s_magic = FUSE_SUPER_MAGIC;
980 sb->s_op = &fuse_super_operations;
981 sb->s_maxbytes = MAX_LFS_FILESIZE;
983 sb->s_export_op = &fuse_export_operations;
990 if (file->f_op != &fuse_dev_operations)
993 fc = kmalloc(sizeof(*fc), GFP_KERNEL);
1000 fc->dev = sb->s_dev;
1002 err = fuse_bdi_init(fc, sb);
1006 sb->s_bdi = &fc->bdi;
1008 /* Handle umasking inside the fuse code */
1009 if (sb->s_flags & MS_POSIXACL)
1011 sb->s_flags |= MS_POSIXACL;
1013 fc->release = fuse_free_conn;
1014 fc->flags = d.flags;
1015 fc->user_id = d.user_id;
1016 fc->group_id = d.group_id;
1017 fc->max_read = max_t(unsigned, 4096, d.max_read);
1019 /* Used by get_root_inode() */
1023 root = fuse_get_root_inode(sb, d.rootmode);
1024 root_dentry = d_make_root(root);
1027 /* only now - we want root dentry with NULL ->d_op */
1028 sb->s_d_op = &fuse_dentry_operations;
1030 init_req = fuse_request_alloc();
1035 fc->destroy_req = fuse_request_alloc();
1036 if (!fc->destroy_req)
1037 goto err_free_init_req;
1040 mutex_lock(&fuse_mutex);
1042 if (file->private_data)
1045 err = fuse_ctl_add_conn(fc);
1049 list_add_tail(&fc->entry, &fuse_conn_list);
1050 sb->s_root = root_dentry;
1052 file->private_data = fuse_conn_get(fc);
1053 mutex_unlock(&fuse_mutex);
1055 * atomic_dec_and_test() in fput() provides the necessary
1056 * memory barrier for file->private_data to be visible on all
1061 fuse_send_init(fc, init_req);
1066 mutex_unlock(&fuse_mutex);
1068 fuse_request_free(init_req);
1072 fuse_bdi_destroy(fc);
1080 static struct dentry *fuse_mount(struct file_system_type *fs_type,
1081 int flags, const char *dev_name,
1084 return mount_nodev(fs_type, flags, raw_data, fuse_fill_super);
1087 static void fuse_kill_sb_anon(struct super_block *sb)
1089 struct fuse_conn *fc = get_fuse_conn_super(sb);
1092 down_write(&fc->killsb);
1094 up_write(&fc->killsb);
1097 kill_anon_super(sb);
1100 static struct file_system_type fuse_fs_type = {
1101 .owner = THIS_MODULE,
1103 .fs_flags = FS_HAS_SUBTYPE,
1104 .mount = fuse_mount,
1105 .kill_sb = fuse_kill_sb_anon,
1109 static struct dentry *fuse_mount_blk(struct file_system_type *fs_type,
1110 int flags, const char *dev_name,
1113 return mount_bdev(fs_type, flags, dev_name, raw_data, fuse_fill_super);
1116 static void fuse_kill_sb_blk(struct super_block *sb)
1118 struct fuse_conn *fc = get_fuse_conn_super(sb);
1121 down_write(&fc->killsb);
1123 up_write(&fc->killsb);
1126 kill_block_super(sb);
1129 static struct file_system_type fuseblk_fs_type = {
1130 .owner = THIS_MODULE,
1132 .mount = fuse_mount_blk,
1133 .kill_sb = fuse_kill_sb_blk,
1134 .fs_flags = FS_REQUIRES_DEV | FS_HAS_SUBTYPE,
1137 static inline int register_fuseblk(void)
1139 return register_filesystem(&fuseblk_fs_type);
1142 static inline void unregister_fuseblk(void)
1144 unregister_filesystem(&fuseblk_fs_type);
1147 static inline int register_fuseblk(void)
1152 static inline void unregister_fuseblk(void)
1157 static void fuse_inode_init_once(void *foo)
1159 struct inode *inode = foo;
1161 inode_init_once(inode);
1164 static int __init fuse_fs_init(void)
1168 fuse_inode_cachep = kmem_cache_create("fuse_inode",
1169 sizeof(struct fuse_inode),
1170 0, SLAB_HWCACHE_ALIGN,
1171 fuse_inode_init_once);
1173 if (!fuse_inode_cachep)
1176 err = register_fuseblk();
1180 err = register_filesystem(&fuse_fs_type);
1187 unregister_fuseblk();
1189 kmem_cache_destroy(fuse_inode_cachep);
1194 static void fuse_fs_cleanup(void)
1196 unregister_filesystem(&fuse_fs_type);
1197 unregister_fuseblk();
1198 kmem_cache_destroy(fuse_inode_cachep);
1201 static struct kobject *fuse_kobj;
1202 static struct kobject *connections_kobj;
1204 static int fuse_sysfs_init(void)
1208 fuse_kobj = kobject_create_and_add("fuse", fs_kobj);
1214 connections_kobj = kobject_create_and_add("connections", fuse_kobj);
1215 if (!connections_kobj) {
1217 goto out_fuse_unregister;
1222 out_fuse_unregister:
1223 kobject_put(fuse_kobj);
1228 static void fuse_sysfs_cleanup(void)
1230 kobject_put(connections_kobj);
1231 kobject_put(fuse_kobj);
1234 static int __init fuse_init(void)
1238 printk(KERN_INFO "fuse init (API version %i.%i)\n",
1239 FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
1241 INIT_LIST_HEAD(&fuse_conn_list);
1242 res = fuse_fs_init();
1246 res = fuse_dev_init();
1248 goto err_fs_cleanup;
1250 res = fuse_sysfs_init();
1252 goto err_dev_cleanup;
1254 res = fuse_ctl_init();
1256 goto err_sysfs_cleanup;
1258 sanitize_global_limit(&max_user_bgreq);
1259 sanitize_global_limit(&max_user_congthresh);
1264 fuse_sysfs_cleanup();
1273 static void __exit fuse_exit(void)
1275 printk(KERN_DEBUG "fuse exit\n");
1278 fuse_sysfs_cleanup();
1283 module_init(fuse_init);
1284 module_exit(fuse_exit);