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);
201 spin_lock(&fc->lock);
202 if (attr_version != 0 && fi->attr_version > attr_version) {
203 spin_unlock(&fc->lock);
207 fuse_change_attributes_common(inode, attr, attr_valid);
209 oldsize = inode->i_size;
210 i_size_write(inode, attr->size);
211 spin_unlock(&fc->lock);
213 if (S_ISREG(inode->i_mode) && oldsize != attr->size) {
214 truncate_pagecache(inode, oldsize, attr->size);
215 invalidate_inode_pages2(inode->i_mapping);
219 static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
221 inode->i_mode = attr->mode & S_IFMT;
222 inode->i_size = attr->size;
223 if (S_ISREG(inode->i_mode)) {
224 fuse_init_common(inode);
225 fuse_init_file_inode(inode);
226 } else if (S_ISDIR(inode->i_mode))
227 fuse_init_dir(inode);
228 else if (S_ISLNK(inode->i_mode))
229 fuse_init_symlink(inode);
230 else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
231 S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
232 fuse_init_common(inode);
233 init_special_inode(inode, inode->i_mode,
234 new_decode_dev(attr->rdev));
239 int fuse_inode_eq(struct inode *inode, void *_nodeidp)
241 u64 nodeid = *(u64 *) _nodeidp;
242 if (get_node_id(inode) == nodeid)
248 static int fuse_inode_set(struct inode *inode, void *_nodeidp)
250 u64 nodeid = *(u64 *) _nodeidp;
251 get_fuse_inode(inode)->nodeid = nodeid;
255 struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
256 int generation, struct fuse_attr *attr,
257 u64 attr_valid, u64 attr_version)
260 struct fuse_inode *fi;
261 struct fuse_conn *fc = get_fuse_conn_super(sb);
264 inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid);
268 if ((inode->i_state & I_NEW)) {
269 inode->i_flags |= S_NOATIME|S_NOCMTIME;
270 inode->i_generation = generation;
271 inode->i_data.backing_dev_info = &fc->bdi;
272 fuse_init_inode(inode, attr);
273 unlock_new_inode(inode);
274 } else if ((inode->i_mode ^ attr->mode) & S_IFMT) {
275 /* Inode has changed type, any I/O on the old should fail */
276 make_bad_inode(inode);
281 fi = get_fuse_inode(inode);
282 spin_lock(&fc->lock);
284 spin_unlock(&fc->lock);
285 fuse_change_attributes(inode, attr, attr_valid, attr_version);
290 int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid,
291 loff_t offset, loff_t len)
297 inode = ilookup5(sb, nodeid, fuse_inode_eq, &nodeid);
301 fuse_invalidate_attr(inode);
303 pg_start = offset >> PAGE_CACHE_SHIFT;
307 pg_end = (offset + len - 1) >> PAGE_CACHE_SHIFT;
308 invalidate_inode_pages2_range(inode->i_mapping,
315 static void fuse_umount_begin(struct super_block *sb)
317 fuse_abort_conn(get_fuse_conn_super(sb));
320 static void fuse_send_destroy(struct fuse_conn *fc)
322 struct fuse_req *req = fc->destroy_req;
323 if (req && fc->conn_init) {
324 fc->destroy_req = NULL;
325 req->in.h.opcode = FUSE_DESTROY;
327 fuse_request_send(fc, req);
328 fuse_put_request(fc, req);
332 static void fuse_bdi_destroy(struct fuse_conn *fc)
334 if (fc->bdi_initialized)
335 bdi_destroy(&fc->bdi);
338 void fuse_conn_kill(struct fuse_conn *fc)
340 spin_lock(&fc->lock);
343 spin_unlock(&fc->lock);
344 /* Flush all readers on this fs */
345 kill_fasync(&fc->fasync, SIGIO, POLL_IN);
346 wake_up_all(&fc->waitq);
347 wake_up_all(&fc->blocked_waitq);
348 wake_up_all(&fc->reserved_req_waitq);
349 mutex_lock(&fuse_mutex);
350 list_del(&fc->entry);
351 fuse_ctl_remove_conn(fc);
352 mutex_unlock(&fuse_mutex);
353 fuse_bdi_destroy(fc);
355 EXPORT_SYMBOL_GPL(fuse_conn_kill);
357 static void fuse_put_super(struct super_block *sb)
359 struct fuse_conn *fc = get_fuse_conn_super(sb);
361 fuse_send_destroy(fc);
366 static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
368 stbuf->f_type = FUSE_SUPER_MAGIC;
369 stbuf->f_bsize = attr->bsize;
370 stbuf->f_frsize = attr->frsize;
371 stbuf->f_blocks = attr->blocks;
372 stbuf->f_bfree = attr->bfree;
373 stbuf->f_bavail = attr->bavail;
374 stbuf->f_files = attr->files;
375 stbuf->f_ffree = attr->ffree;
376 stbuf->f_namelen = attr->namelen;
377 /* fsid is left zero */
380 static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf)
382 struct super_block *sb = dentry->d_sb;
383 struct fuse_conn *fc = get_fuse_conn_super(sb);
384 struct fuse_req *req;
385 struct fuse_statfs_out outarg;
388 if (!fuse_allow_task(fc, current)) {
389 buf->f_type = FUSE_SUPER_MAGIC;
393 req = fuse_get_req(fc);
397 memset(&outarg, 0, sizeof(outarg));
399 req->in.h.opcode = FUSE_STATFS;
400 req->in.h.nodeid = get_node_id(dentry->d_inode);
401 req->out.numargs = 1;
402 req->out.args[0].size =
403 fc->minor < 4 ? FUSE_COMPAT_STATFS_SIZE : sizeof(outarg);
404 req->out.args[0].value = &outarg;
405 fuse_request_send(fc, req);
406 err = req->out.h.error;
408 convert_fuse_statfs(buf, &outarg.st);
409 fuse_put_request(fc, req);
418 OPT_DEFAULT_PERMISSIONS,
425 static const match_table_t tokens = {
427 {OPT_ROOTMODE, "rootmode=%o"},
428 {OPT_USER_ID, "user_id=%u"},
429 {OPT_GROUP_ID, "group_id=%u"},
430 {OPT_DEFAULT_PERMISSIONS, "default_permissions"},
431 {OPT_ALLOW_OTHER, "allow_other"},
432 {OPT_MAX_READ, "max_read=%u"},
433 {OPT_BLKSIZE, "blksize=%u"},
437 static int parse_fuse_opt(char *opt, struct fuse_mount_data *d, int is_bdev)
440 memset(d, 0, sizeof(struct fuse_mount_data));
442 d->blksize = FUSE_DEFAULT_BLKSIZE;
444 while ((p = strsep(&opt, ",")) != NULL) {
447 substring_t args[MAX_OPT_ARGS];
451 token = match_token(p, tokens, args);
454 if (match_int(&args[0], &value))
461 if (match_octal(&args[0], &value))
463 if (!fuse_valid_type(value))
466 d->rootmode_present = 1;
470 if (match_int(&args[0], &value))
473 d->user_id_present = 1;
477 if (match_int(&args[0], &value))
480 d->group_id_present = 1;
483 case OPT_DEFAULT_PERMISSIONS:
484 d->flags |= FUSE_DEFAULT_PERMISSIONS;
487 case OPT_ALLOW_OTHER:
488 d->flags |= FUSE_ALLOW_OTHER;
492 if (match_int(&args[0], &value))
498 if (!is_bdev || match_int(&args[0], &value))
508 if (!d->fd_present || !d->rootmode_present ||
509 !d->user_id_present || !d->group_id_present)
515 static int fuse_show_options(struct seq_file *m, struct dentry *root)
517 struct super_block *sb = root->d_sb;
518 struct fuse_conn *fc = get_fuse_conn_super(sb);
520 seq_printf(m, ",user_id=%u", fc->user_id);
521 seq_printf(m, ",group_id=%u", fc->group_id);
522 if (fc->flags & FUSE_DEFAULT_PERMISSIONS)
523 seq_puts(m, ",default_permissions");
524 if (fc->flags & FUSE_ALLOW_OTHER)
525 seq_puts(m, ",allow_other");
526 if (fc->max_read != ~0)
527 seq_printf(m, ",max_read=%u", fc->max_read);
528 if (sb->s_bdev && sb->s_blocksize != FUSE_DEFAULT_BLKSIZE)
529 seq_printf(m, ",blksize=%lu", sb->s_blocksize);
533 void fuse_conn_init(struct fuse_conn *fc)
535 memset(fc, 0, sizeof(*fc));
536 spin_lock_init(&fc->lock);
537 mutex_init(&fc->inst_mutex);
538 init_rwsem(&fc->killsb);
539 atomic_set(&fc->count, 1);
540 init_waitqueue_head(&fc->waitq);
541 init_waitqueue_head(&fc->blocked_waitq);
542 init_waitqueue_head(&fc->reserved_req_waitq);
543 INIT_LIST_HEAD(&fc->pending);
544 INIT_LIST_HEAD(&fc->processing);
545 INIT_LIST_HEAD(&fc->io);
546 INIT_LIST_HEAD(&fc->interrupts);
547 INIT_LIST_HEAD(&fc->bg_queue);
548 INIT_LIST_HEAD(&fc->entry);
549 fc->forget_list_tail = &fc->forget_list_head;
550 atomic_set(&fc->num_waiting, 0);
551 fc->max_background = FUSE_DEFAULT_MAX_BACKGROUND;
552 fc->congestion_threshold = FUSE_DEFAULT_CONGESTION_THRESHOLD;
554 fc->polled_files = RB_ROOT;
557 fc->attr_version = 1;
558 get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key));
560 EXPORT_SYMBOL_GPL(fuse_conn_init);
562 void fuse_conn_put(struct fuse_conn *fc)
564 if (atomic_dec_and_test(&fc->count)) {
566 fuse_request_free(fc->destroy_req);
567 mutex_destroy(&fc->inst_mutex);
571 EXPORT_SYMBOL_GPL(fuse_conn_put);
573 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc)
575 atomic_inc(&fc->count);
578 EXPORT_SYMBOL_GPL(fuse_conn_get);
580 static struct inode *fuse_get_root_inode(struct super_block *sb, unsigned mode)
582 struct fuse_attr attr;
583 memset(&attr, 0, sizeof(attr));
586 attr.ino = FUSE_ROOT_ID;
588 return fuse_iget(sb, 1, 0, &attr, 0, 0);
591 struct fuse_inode_handle {
596 static struct dentry *fuse_get_dentry(struct super_block *sb,
597 struct fuse_inode_handle *handle)
599 struct fuse_conn *fc = get_fuse_conn_super(sb);
601 struct dentry *entry;
604 if (handle->nodeid == 0)
607 inode = ilookup5(sb, handle->nodeid, fuse_inode_eq, &handle->nodeid);
609 struct fuse_entry_out outarg;
612 if (!fc->export_support)
617 err = fuse_lookup_name(sb, handle->nodeid, &name, &outarg,
619 if (err && err != -ENOENT)
626 if (get_node_id(inode) != handle->nodeid)
630 if (inode->i_generation != handle->generation)
633 entry = d_obtain_alias(inode);
634 if (!IS_ERR(entry) && get_node_id(inode) != FUSE_ROOT_ID)
635 fuse_invalidate_entry_cache(entry);
645 static int fuse_encode_fh(struct inode *inode, u32 *fh, int *max_len,
646 struct inode *parent)
648 int len = parent ? 6 : 3;
652 if (*max_len < len) {
657 nodeid = get_fuse_inode(inode)->nodeid;
658 generation = inode->i_generation;
660 fh[0] = (u32)(nodeid >> 32);
661 fh[1] = (u32)(nodeid & 0xffffffff);
665 nodeid = get_fuse_inode(parent)->nodeid;
666 generation = parent->i_generation;
668 fh[3] = (u32)(nodeid >> 32);
669 fh[4] = (u32)(nodeid & 0xffffffff);
674 return parent ? 0x82 : 0x81;
677 static struct dentry *fuse_fh_to_dentry(struct super_block *sb,
678 struct fid *fid, int fh_len, int fh_type)
680 struct fuse_inode_handle handle;
682 if ((fh_type != 0x81 && fh_type != 0x82) || fh_len < 3)
685 handle.nodeid = (u64) fid->raw[0] << 32;
686 handle.nodeid |= (u64) fid->raw[1];
687 handle.generation = fid->raw[2];
688 return fuse_get_dentry(sb, &handle);
691 static struct dentry *fuse_fh_to_parent(struct super_block *sb,
692 struct fid *fid, int fh_len, int fh_type)
694 struct fuse_inode_handle parent;
696 if (fh_type != 0x82 || fh_len < 6)
699 parent.nodeid = (u64) fid->raw[3] << 32;
700 parent.nodeid |= (u64) fid->raw[4];
701 parent.generation = fid->raw[5];
702 return fuse_get_dentry(sb, &parent);
705 static struct dentry *fuse_get_parent(struct dentry *child)
707 struct inode *child_inode = child->d_inode;
708 struct fuse_conn *fc = get_fuse_conn(child_inode);
710 struct dentry *parent;
711 struct fuse_entry_out outarg;
715 if (!fc->export_support)
716 return ERR_PTR(-ESTALE);
720 err = fuse_lookup_name(child_inode->i_sb, get_node_id(child_inode),
721 &name, &outarg, &inode);
724 return ERR_PTR(-ESTALE);
728 parent = d_obtain_alias(inode);
729 if (!IS_ERR(parent) && get_node_id(inode) != FUSE_ROOT_ID)
730 fuse_invalidate_entry_cache(parent);
735 static const struct export_operations fuse_export_operations = {
736 .fh_to_dentry = fuse_fh_to_dentry,
737 .fh_to_parent = fuse_fh_to_parent,
738 .encode_fh = fuse_encode_fh,
739 .get_parent = fuse_get_parent,
742 static const struct super_operations fuse_super_operations = {
743 .alloc_inode = fuse_alloc_inode,
744 .destroy_inode = fuse_destroy_inode,
745 .evict_inode = fuse_evict_inode,
746 .drop_inode = generic_delete_inode,
747 .remount_fs = fuse_remount_fs,
748 .put_super = fuse_put_super,
749 .umount_begin = fuse_umount_begin,
750 .statfs = fuse_statfs,
751 .show_options = fuse_show_options,
754 static void sanitize_global_limit(unsigned *limit)
757 *limit = ((num_physpages << PAGE_SHIFT) >> 13) /
758 sizeof(struct fuse_req);
760 if (*limit >= 1 << 16)
761 *limit = (1 << 16) - 1;
764 static int set_global_limit(const char *val, struct kernel_param *kp)
768 rv = param_set_uint(val, kp);
772 sanitize_global_limit((unsigned *)kp->arg);
777 static void process_init_limits(struct fuse_conn *fc, struct fuse_init_out *arg)
779 int cap_sys_admin = capable(CAP_SYS_ADMIN);
784 sanitize_global_limit(&max_user_bgreq);
785 sanitize_global_limit(&max_user_congthresh);
787 if (arg->max_background) {
788 fc->max_background = arg->max_background;
790 if (!cap_sys_admin && fc->max_background > max_user_bgreq)
791 fc->max_background = max_user_bgreq;
793 if (arg->congestion_threshold) {
794 fc->congestion_threshold = arg->congestion_threshold;
796 if (!cap_sys_admin &&
797 fc->congestion_threshold > max_user_congthresh)
798 fc->congestion_threshold = max_user_congthresh;
802 static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
804 struct fuse_init_out *arg = &req->misc.init_out;
806 if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION)
809 unsigned long ra_pages;
811 process_init_limits(fc, arg);
813 if (arg->minor >= 6) {
814 ra_pages = arg->max_readahead / PAGE_CACHE_SIZE;
815 if (arg->flags & FUSE_ASYNC_READ)
817 if (!(arg->flags & FUSE_POSIX_LOCKS))
819 if (arg->minor >= 17) {
820 if (!(arg->flags & FUSE_FLOCK_LOCKS))
823 if (!(arg->flags & FUSE_POSIX_LOCKS))
826 if (arg->flags & FUSE_ATOMIC_O_TRUNC)
827 fc->atomic_o_trunc = 1;
828 if (arg->minor >= 9) {
829 /* LOOKUP has dependency on proto version */
830 if (arg->flags & FUSE_EXPORT_SUPPORT)
831 fc->export_support = 1;
833 if (arg->flags & FUSE_BIG_WRITES)
835 if (arg->flags & FUSE_DONT_MASK)
838 ra_pages = fc->max_read / PAGE_CACHE_SIZE;
843 fc->bdi.ra_pages = min(fc->bdi.ra_pages, ra_pages);
844 fc->minor = arg->minor;
845 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
846 fc->max_write = max_t(unsigned, 4096, fc->max_write);
850 wake_up_all(&fc->blocked_waitq);
853 static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req)
855 struct fuse_init_in *arg = &req->misc.init_in;
857 arg->major = FUSE_KERNEL_VERSION;
858 arg->minor = FUSE_KERNEL_MINOR_VERSION;
859 arg->max_readahead = fc->bdi.ra_pages * PAGE_CACHE_SIZE;
860 arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_ATOMIC_O_TRUNC |
861 FUSE_EXPORT_SUPPORT | FUSE_BIG_WRITES | FUSE_DONT_MASK |
863 req->in.h.opcode = FUSE_INIT;
865 req->in.args[0].size = sizeof(*arg);
866 req->in.args[0].value = arg;
867 req->out.numargs = 1;
868 /* Variable length argument used for backward compatibility
869 with interface version < 7.5. Rest of init_out is zeroed
870 by do_get_request(), so a short reply is not a problem */
872 req->out.args[0].size = sizeof(struct fuse_init_out);
873 req->out.args[0].value = &req->misc.init_out;
874 req->end = process_init_reply;
875 fuse_request_send_background(fc, req);
878 static void fuse_free_conn(struct fuse_conn *fc)
883 static int fuse_bdi_init(struct fuse_conn *fc, struct super_block *sb)
887 fc->bdi.name = "fuse";
888 fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
889 /* fuse does it's own writeback accounting */
890 fc->bdi.capabilities = BDI_CAP_NO_ACCT_WB;
892 err = bdi_init(&fc->bdi);
896 fc->bdi_initialized = 1;
899 err = bdi_register(&fc->bdi, NULL, "%u:%u-fuseblk",
900 MAJOR(fc->dev), MINOR(fc->dev));
902 err = bdi_register_dev(&fc->bdi, fc->dev);
909 * For a single fuse filesystem use max 1% of dirty +
910 * writeback threshold.
912 * This gives about 1M of write buffer for memory maps on a
913 * machine with 1G and 10% dirty_ratio, which should be more
916 * Privileged users can raise it by writing to
918 * /sys/class/bdi/<bdi>/max_ratio
920 bdi_set_max_ratio(&fc->bdi, 1);
925 static int fuse_fill_super(struct super_block *sb, void *data, int silent)
927 struct fuse_conn *fc;
929 struct fuse_mount_data d;
931 struct dentry *root_dentry;
932 struct fuse_req *init_req;
934 int is_bdev = sb->s_bdev != NULL;
937 if (sb->s_flags & MS_MANDLOCK)
940 sb->s_flags &= ~MS_NOSEC;
942 if (!parse_fuse_opt((char *) data, &d, is_bdev))
948 if (!sb_set_blocksize(sb, d.blksize))
952 sb->s_blocksize = PAGE_CACHE_SIZE;
953 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
955 sb->s_magic = FUSE_SUPER_MAGIC;
956 sb->s_op = &fuse_super_operations;
957 sb->s_maxbytes = MAX_LFS_FILESIZE;
959 sb->s_export_op = &fuse_export_operations;
966 if (file->f_op != &fuse_dev_operations)
969 fc = kmalloc(sizeof(*fc), GFP_KERNEL);
978 err = fuse_bdi_init(fc, sb);
982 sb->s_bdi = &fc->bdi;
984 /* Handle umasking inside the fuse code */
985 if (sb->s_flags & MS_POSIXACL)
987 sb->s_flags |= MS_POSIXACL;
989 fc->release = fuse_free_conn;
991 fc->user_id = d.user_id;
992 fc->group_id = d.group_id;
993 fc->max_read = max_t(unsigned, 4096, d.max_read);
995 /* Used by get_root_inode() */
999 root = fuse_get_root_inode(sb, d.rootmode);
1000 root_dentry = d_make_root(root);
1003 /* only now - we want root dentry with NULL ->d_op */
1004 sb->s_d_op = &fuse_dentry_operations;
1006 init_req = fuse_request_alloc();
1011 fc->destroy_req = fuse_request_alloc();
1012 if (!fc->destroy_req)
1013 goto err_free_init_req;
1016 mutex_lock(&fuse_mutex);
1018 if (file->private_data)
1021 err = fuse_ctl_add_conn(fc);
1025 list_add_tail(&fc->entry, &fuse_conn_list);
1026 sb->s_root = root_dentry;
1028 file->private_data = fuse_conn_get(fc);
1029 mutex_unlock(&fuse_mutex);
1031 * atomic_dec_and_test() in fput() provides the necessary
1032 * memory barrier for file->private_data to be visible on all
1037 fuse_send_init(fc, init_req);
1042 mutex_unlock(&fuse_mutex);
1044 fuse_request_free(init_req);
1048 fuse_bdi_destroy(fc);
1056 static struct dentry *fuse_mount(struct file_system_type *fs_type,
1057 int flags, const char *dev_name,
1060 return mount_nodev(fs_type, flags, raw_data, fuse_fill_super);
1063 static void fuse_kill_sb_anon(struct super_block *sb)
1065 struct fuse_conn *fc = get_fuse_conn_super(sb);
1068 down_write(&fc->killsb);
1070 up_write(&fc->killsb);
1073 kill_anon_super(sb);
1076 static struct file_system_type fuse_fs_type = {
1077 .owner = THIS_MODULE,
1079 .fs_flags = FS_HAS_SUBTYPE,
1080 .mount = fuse_mount,
1081 .kill_sb = fuse_kill_sb_anon,
1085 static struct dentry *fuse_mount_blk(struct file_system_type *fs_type,
1086 int flags, const char *dev_name,
1089 return mount_bdev(fs_type, flags, dev_name, raw_data, fuse_fill_super);
1092 static void fuse_kill_sb_blk(struct super_block *sb)
1094 struct fuse_conn *fc = get_fuse_conn_super(sb);
1097 down_write(&fc->killsb);
1099 up_write(&fc->killsb);
1102 kill_block_super(sb);
1105 static struct file_system_type fuseblk_fs_type = {
1106 .owner = THIS_MODULE,
1108 .mount = fuse_mount_blk,
1109 .kill_sb = fuse_kill_sb_blk,
1110 .fs_flags = FS_REQUIRES_DEV | FS_HAS_SUBTYPE,
1113 static inline int register_fuseblk(void)
1115 return register_filesystem(&fuseblk_fs_type);
1118 static inline void unregister_fuseblk(void)
1120 unregister_filesystem(&fuseblk_fs_type);
1123 static inline int register_fuseblk(void)
1128 static inline void unregister_fuseblk(void)
1133 static void fuse_inode_init_once(void *foo)
1135 struct inode *inode = foo;
1137 inode_init_once(inode);
1140 static int __init fuse_fs_init(void)
1144 fuse_inode_cachep = kmem_cache_create("fuse_inode",
1145 sizeof(struct fuse_inode),
1146 0, SLAB_HWCACHE_ALIGN,
1147 fuse_inode_init_once);
1149 if (!fuse_inode_cachep)
1152 err = register_fuseblk();
1156 err = register_filesystem(&fuse_fs_type);
1163 unregister_fuseblk();
1165 kmem_cache_destroy(fuse_inode_cachep);
1170 static void fuse_fs_cleanup(void)
1172 unregister_filesystem(&fuse_fs_type);
1173 unregister_fuseblk();
1174 kmem_cache_destroy(fuse_inode_cachep);
1177 static struct kobject *fuse_kobj;
1178 static struct kobject *connections_kobj;
1180 static int fuse_sysfs_init(void)
1184 fuse_kobj = kobject_create_and_add("fuse", fs_kobj);
1190 connections_kobj = kobject_create_and_add("connections", fuse_kobj);
1191 if (!connections_kobj) {
1193 goto out_fuse_unregister;
1198 out_fuse_unregister:
1199 kobject_put(fuse_kobj);
1204 static void fuse_sysfs_cleanup(void)
1206 kobject_put(connections_kobj);
1207 kobject_put(fuse_kobj);
1210 static int __init fuse_init(void)
1214 printk(KERN_INFO "fuse init (API version %i.%i)\n",
1215 FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
1217 INIT_LIST_HEAD(&fuse_conn_list);
1218 res = fuse_fs_init();
1222 res = fuse_dev_init();
1224 goto err_fs_cleanup;
1226 res = fuse_sysfs_init();
1228 goto err_dev_cleanup;
1230 res = fuse_ctl_init();
1232 goto err_sysfs_cleanup;
1234 sanitize_global_limit(&max_user_bgreq);
1235 sanitize_global_limit(&max_user_congthresh);
1240 fuse_sysfs_cleanup();
1249 static void __exit fuse_exit(void)
1251 printk(KERN_DEBUG "fuse exit\n");
1254 fuse_sysfs_cleanup();
1259 module_init(fuse_init);
1260 module_exit(fuse_exit);