2 FUSE: Filesystem in Userspace
3 Copyright (C) 2001-2006 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/parser.h>
18 #include <linux/statfs.h>
19 #include <linux/random.h>
20 #include <linux/sched.h>
22 MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>");
23 MODULE_DESCRIPTION("Filesystem in Userspace");
24 MODULE_LICENSE("GPL");
26 static struct kmem_cache *fuse_inode_cachep;
27 struct list_head fuse_conn_list;
28 DEFINE_MUTEX(fuse_mutex);
30 #define FUSE_SUPER_MAGIC 0x65735546
32 struct fuse_mount_data {
37 unsigned fd_present : 1;
38 unsigned rootmode_present : 1;
39 unsigned user_id_present : 1;
40 unsigned group_id_present : 1;
46 static struct inode *fuse_alloc_inode(struct super_block *sb)
49 struct fuse_inode *fi;
51 inode = kmem_cache_alloc(fuse_inode_cachep, GFP_KERNEL);
55 fi = get_fuse_inode(inode);
59 fi->forget_req = fuse_request_alloc();
60 if (!fi->forget_req) {
61 kmem_cache_free(fuse_inode_cachep, inode);
68 static void fuse_destroy_inode(struct inode *inode)
70 struct fuse_inode *fi = get_fuse_inode(inode);
72 fuse_request_free(fi->forget_req);
73 kmem_cache_free(fuse_inode_cachep, inode);
76 static void fuse_read_inode(struct inode *inode)
81 void fuse_send_forget(struct fuse_conn *fc, struct fuse_req *req,
82 unsigned long nodeid, u64 nlookup)
84 struct fuse_forget_in *inarg = &req->misc.forget_in;
85 inarg->nlookup = nlookup;
86 req->in.h.opcode = FUSE_FORGET;
87 req->in.h.nodeid = nodeid;
89 req->in.args[0].size = sizeof(struct fuse_forget_in);
90 req->in.args[0].value = inarg;
91 request_send_noreply(fc, req);
94 static void fuse_clear_inode(struct inode *inode)
96 if (inode->i_sb->s_flags & MS_ACTIVE) {
97 struct fuse_conn *fc = get_fuse_conn(inode);
98 struct fuse_inode *fi = get_fuse_inode(inode);
99 fuse_send_forget(fc, fi->forget_req, fi->nodeid, fi->nlookup);
100 fi->forget_req = NULL;
104 static int fuse_remount_fs(struct super_block *sb, int *flags, char *data)
106 if (*flags & MS_MANDLOCK)
112 static void fuse_truncate(struct address_space *mapping, loff_t offset)
114 /* See vmtruncate() */
115 unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1);
116 truncate_inode_pages(mapping, offset);
117 unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1);
120 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr)
122 struct fuse_conn *fc = get_fuse_conn(inode);
123 struct fuse_inode *fi = get_fuse_inode(inode);
126 inode->i_ino = attr->ino;
127 inode->i_mode = (inode->i_mode & S_IFMT) | (attr->mode & 07777);
128 inode->i_nlink = attr->nlink;
129 inode->i_uid = attr->uid;
130 inode->i_gid = attr->gid;
131 inode->i_blocks = attr->blocks;
132 inode->i_atime.tv_sec = attr->atime;
133 inode->i_atime.tv_nsec = attr->atimensec;
134 inode->i_mtime.tv_sec = attr->mtime;
135 inode->i_mtime.tv_nsec = attr->mtimensec;
136 inode->i_ctime.tv_sec = attr->ctime;
137 inode->i_ctime.tv_nsec = attr->ctimensec;
140 * Don't set the sticky bit in i_mode, unless we want the VFS
141 * to check permissions. This prevents failures due to the
142 * check in may_delete().
144 fi->orig_i_mode = inode->i_mode;
145 if (!(fc->flags & FUSE_DEFAULT_PERMISSIONS))
146 inode->i_mode &= ~S_ISVTX;
148 spin_lock(&fc->lock);
149 oldsize = inode->i_size;
150 i_size_write(inode, attr->size);
151 spin_unlock(&fc->lock);
153 if (S_ISREG(inode->i_mode) && oldsize != attr->size) {
154 if (attr->size < oldsize)
155 fuse_truncate(inode->i_mapping, attr->size);
156 invalidate_inode_pages2(inode->i_mapping);
160 static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
162 inode->i_mode = attr->mode & S_IFMT;
163 inode->i_size = attr->size;
164 if (S_ISREG(inode->i_mode)) {
165 fuse_init_common(inode);
166 fuse_init_file_inode(inode);
167 } else if (S_ISDIR(inode->i_mode))
168 fuse_init_dir(inode);
169 else if (S_ISLNK(inode->i_mode))
170 fuse_init_symlink(inode);
171 else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
172 S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
173 fuse_init_common(inode);
174 init_special_inode(inode, inode->i_mode,
175 new_decode_dev(attr->rdev));
180 static int fuse_inode_eq(struct inode *inode, void *_nodeidp)
182 unsigned long nodeid = *(unsigned long *) _nodeidp;
183 if (get_node_id(inode) == nodeid)
189 static int fuse_inode_set(struct inode *inode, void *_nodeidp)
191 unsigned long nodeid = *(unsigned long *) _nodeidp;
192 get_fuse_inode(inode)->nodeid = nodeid;
196 struct inode *fuse_iget(struct super_block *sb, unsigned long nodeid,
197 int generation, struct fuse_attr *attr)
200 struct fuse_inode *fi;
201 struct fuse_conn *fc = get_fuse_conn_super(sb);
204 inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid);
208 if ((inode->i_state & I_NEW)) {
209 inode->i_flags |= S_NOATIME|S_NOCMTIME;
210 inode->i_generation = generation;
211 inode->i_data.backing_dev_info = &fc->bdi;
212 fuse_init_inode(inode, attr);
213 unlock_new_inode(inode);
214 } else if ((inode->i_mode ^ attr->mode) & S_IFMT) {
215 /* Inode has changed type, any I/O on the old should fail */
216 make_bad_inode(inode);
221 fi = get_fuse_inode(inode);
222 spin_lock(&fc->lock);
224 spin_unlock(&fc->lock);
225 fuse_change_attributes(inode, attr);
229 static void fuse_umount_begin(struct vfsmount *vfsmnt, int flags)
231 if (flags & MNT_FORCE)
232 fuse_abort_conn(get_fuse_conn_super(vfsmnt->mnt_sb));
235 static void fuse_send_destroy(struct fuse_conn *fc)
237 struct fuse_req *req = fc->destroy_req;
238 if (req && fc->conn_init) {
239 fc->destroy_req = NULL;
240 req->in.h.opcode = FUSE_DESTROY;
242 request_send(fc, req);
243 fuse_put_request(fc, req);
247 static void fuse_put_super(struct super_block *sb)
249 struct fuse_conn *fc = get_fuse_conn_super(sb);
251 fuse_send_destroy(fc);
252 spin_lock(&fc->lock);
255 spin_unlock(&fc->lock);
256 /* Flush all readers on this fs */
257 kill_fasync(&fc->fasync, SIGIO, POLL_IN);
258 wake_up_all(&fc->waitq);
259 wake_up_all(&fc->blocked_waitq);
260 wake_up_all(&fc->reserved_req_waitq);
261 mutex_lock(&fuse_mutex);
262 list_del(&fc->entry);
263 fuse_ctl_remove_conn(fc);
264 mutex_unlock(&fuse_mutex);
268 static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
270 stbuf->f_type = FUSE_SUPER_MAGIC;
271 stbuf->f_bsize = attr->bsize;
272 stbuf->f_frsize = attr->frsize;
273 stbuf->f_blocks = attr->blocks;
274 stbuf->f_bfree = attr->bfree;
275 stbuf->f_bavail = attr->bavail;
276 stbuf->f_files = attr->files;
277 stbuf->f_ffree = attr->ffree;
278 stbuf->f_namelen = attr->namelen;
279 /* fsid is left zero */
282 static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf)
284 struct super_block *sb = dentry->d_sb;
285 struct fuse_conn *fc = get_fuse_conn_super(sb);
286 struct fuse_req *req;
287 struct fuse_statfs_out outarg;
290 if (!fuse_allow_task(fc, current)) {
291 buf->f_type = FUSE_SUPER_MAGIC;
295 req = fuse_get_req(fc);
299 memset(&outarg, 0, sizeof(outarg));
301 req->in.h.opcode = FUSE_STATFS;
302 req->in.h.nodeid = get_node_id(dentry->d_inode);
303 req->out.numargs = 1;
304 req->out.args[0].size =
305 fc->minor < 4 ? FUSE_COMPAT_STATFS_SIZE : sizeof(outarg);
306 req->out.args[0].value = &outarg;
307 request_send(fc, req);
308 err = req->out.h.error;
310 convert_fuse_statfs(buf, &outarg.st);
311 fuse_put_request(fc, req);
320 OPT_DEFAULT_PERMISSIONS,
327 static match_table_t tokens = {
329 {OPT_ROOTMODE, "rootmode=%o"},
330 {OPT_USER_ID, "user_id=%u"},
331 {OPT_GROUP_ID, "group_id=%u"},
332 {OPT_DEFAULT_PERMISSIONS, "default_permissions"},
333 {OPT_ALLOW_OTHER, "allow_other"},
334 {OPT_MAX_READ, "max_read=%u"},
335 {OPT_BLKSIZE, "blksize=%u"},
339 static int parse_fuse_opt(char *opt, struct fuse_mount_data *d, int is_bdev)
342 memset(d, 0, sizeof(struct fuse_mount_data));
346 while ((p = strsep(&opt, ",")) != NULL) {
349 substring_t args[MAX_OPT_ARGS];
353 token = match_token(p, tokens, args);
356 if (match_int(&args[0], &value))
363 if (match_octal(&args[0], &value))
365 if (!fuse_valid_type(value))
368 d->rootmode_present = 1;
372 if (match_int(&args[0], &value))
375 d->user_id_present = 1;
379 if (match_int(&args[0], &value))
382 d->group_id_present = 1;
385 case OPT_DEFAULT_PERMISSIONS:
386 d->flags |= FUSE_DEFAULT_PERMISSIONS;
389 case OPT_ALLOW_OTHER:
390 d->flags |= FUSE_ALLOW_OTHER;
394 if (match_int(&args[0], &value))
400 if (!is_bdev || match_int(&args[0], &value))
410 if (!d->fd_present || !d->rootmode_present ||
411 !d->user_id_present || !d->group_id_present)
417 static int fuse_show_options(struct seq_file *m, struct vfsmount *mnt)
419 struct fuse_conn *fc = get_fuse_conn_super(mnt->mnt_sb);
421 seq_printf(m, ",user_id=%u", fc->user_id);
422 seq_printf(m, ",group_id=%u", fc->group_id);
423 if (fc->flags & FUSE_DEFAULT_PERMISSIONS)
424 seq_puts(m, ",default_permissions");
425 if (fc->flags & FUSE_ALLOW_OTHER)
426 seq_puts(m, ",allow_other");
427 if (fc->max_read != ~0)
428 seq_printf(m, ",max_read=%u", fc->max_read);
432 static struct fuse_conn *new_conn(void)
434 struct fuse_conn *fc;
437 fc = kzalloc(sizeof(*fc), GFP_KERNEL);
439 spin_lock_init(&fc->lock);
440 mutex_init(&fc->inst_mutex);
441 atomic_set(&fc->count, 1);
442 init_waitqueue_head(&fc->waitq);
443 init_waitqueue_head(&fc->blocked_waitq);
444 init_waitqueue_head(&fc->reserved_req_waitq);
445 INIT_LIST_HEAD(&fc->pending);
446 INIT_LIST_HEAD(&fc->processing);
447 INIT_LIST_HEAD(&fc->io);
448 INIT_LIST_HEAD(&fc->interrupts);
449 atomic_set(&fc->num_waiting, 0);
450 fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
451 fc->bdi.unplug_io_fn = default_unplug_io_fn;
452 err = bdi_init(&fc->bdi);
460 get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key));
466 void fuse_conn_put(struct fuse_conn *fc)
468 if (atomic_dec_and_test(&fc->count)) {
470 fuse_request_free(fc->destroy_req);
471 mutex_destroy(&fc->inst_mutex);
472 bdi_destroy(&fc->bdi);
477 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc)
479 atomic_inc(&fc->count);
483 static struct inode *get_root_inode(struct super_block *sb, unsigned mode)
485 struct fuse_attr attr;
486 memset(&attr, 0, sizeof(attr));
489 attr.ino = FUSE_ROOT_ID;
491 return fuse_iget(sb, 1, 0, &attr);
494 static const struct super_operations fuse_super_operations = {
495 .alloc_inode = fuse_alloc_inode,
496 .destroy_inode = fuse_destroy_inode,
497 .read_inode = fuse_read_inode,
498 .clear_inode = fuse_clear_inode,
499 .drop_inode = generic_delete_inode,
500 .remount_fs = fuse_remount_fs,
501 .put_super = fuse_put_super,
502 .umount_begin = fuse_umount_begin,
503 .statfs = fuse_statfs,
504 .show_options = fuse_show_options,
507 static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
509 struct fuse_init_out *arg = &req->misc.init_out;
511 if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION)
514 unsigned long ra_pages;
516 if (arg->minor >= 6) {
517 ra_pages = arg->max_readahead / PAGE_CACHE_SIZE;
518 if (arg->flags & FUSE_ASYNC_READ)
520 if (!(arg->flags & FUSE_POSIX_LOCKS))
523 ra_pages = fc->max_read / PAGE_CACHE_SIZE;
527 fc->bdi.ra_pages = min(fc->bdi.ra_pages, ra_pages);
528 fc->minor = arg->minor;
529 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
532 fuse_put_request(fc, req);
534 wake_up_all(&fc->blocked_waitq);
537 static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req)
539 struct fuse_init_in *arg = &req->misc.init_in;
541 arg->major = FUSE_KERNEL_VERSION;
542 arg->minor = FUSE_KERNEL_MINOR_VERSION;
543 arg->max_readahead = fc->bdi.ra_pages * PAGE_CACHE_SIZE;
544 arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS;
545 req->in.h.opcode = FUSE_INIT;
547 req->in.args[0].size = sizeof(*arg);
548 req->in.args[0].value = arg;
549 req->out.numargs = 1;
550 /* Variable length arguement used for backward compatibility
551 with interface version < 7.5. Rest of init_out is zeroed
552 by do_get_request(), so a short reply is not a problem */
554 req->out.args[0].size = sizeof(struct fuse_init_out);
555 req->out.args[0].value = &req->misc.init_out;
556 req->end = process_init_reply;
557 request_send_background(fc, req);
560 static u64 conn_id(void)
566 static int fuse_fill_super(struct super_block *sb, void *data, int silent)
568 struct fuse_conn *fc;
570 struct fuse_mount_data d;
572 struct dentry *root_dentry;
573 struct fuse_req *init_req;
575 int is_bdev = sb->s_bdev != NULL;
577 if (sb->s_flags & MS_MANDLOCK)
580 if (!parse_fuse_opt((char *) data, &d, is_bdev))
585 if (!sb_set_blocksize(sb, d.blksize))
589 sb->s_blocksize = PAGE_CACHE_SIZE;
590 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
592 sb->s_magic = FUSE_SUPER_MAGIC;
593 sb->s_op = &fuse_super_operations;
594 sb->s_maxbytes = MAX_LFS_FILESIZE;
600 if (file->f_op != &fuse_dev_operations)
608 fc->user_id = d.user_id;
609 fc->group_id = d.group_id;
610 fc->max_read = d.max_read;
612 /* Used by get_root_inode() */
616 root = get_root_inode(sb, d.rootmode);
620 root_dentry = d_alloc_root(root);
626 init_req = fuse_request_alloc();
631 fc->destroy_req = fuse_request_alloc();
632 if (!fc->destroy_req)
636 mutex_lock(&fuse_mutex);
638 if (file->private_data)
642 err = fuse_ctl_add_conn(fc);
646 list_add_tail(&fc->entry, &fuse_conn_list);
647 sb->s_root = root_dentry;
649 file->private_data = fuse_conn_get(fc);
650 mutex_unlock(&fuse_mutex);
652 * atomic_dec_and_test() in fput() provides the necessary
653 * memory barrier for file->private_data to be visible on all
658 fuse_send_init(fc, init_req);
663 mutex_unlock(&fuse_mutex);
664 fuse_request_free(init_req);
673 static int fuse_get_sb(struct file_system_type *fs_type,
674 int flags, const char *dev_name,
675 void *raw_data, struct vfsmount *mnt)
677 return get_sb_nodev(fs_type, flags, raw_data, fuse_fill_super, mnt);
680 static struct file_system_type fuse_fs_type = {
681 .owner = THIS_MODULE,
683 .fs_flags = FS_HAS_SUBTYPE,
684 .get_sb = fuse_get_sb,
685 .kill_sb = kill_anon_super,
689 static int fuse_get_sb_blk(struct file_system_type *fs_type,
690 int flags, const char *dev_name,
691 void *raw_data, struct vfsmount *mnt)
693 return get_sb_bdev(fs_type, flags, dev_name, raw_data, fuse_fill_super,
697 static struct file_system_type fuseblk_fs_type = {
698 .owner = THIS_MODULE,
700 .get_sb = fuse_get_sb_blk,
701 .kill_sb = kill_block_super,
702 .fs_flags = FS_REQUIRES_DEV | FS_HAS_SUBTYPE,
705 static inline int register_fuseblk(void)
707 return register_filesystem(&fuseblk_fs_type);
710 static inline void unregister_fuseblk(void)
712 unregister_filesystem(&fuseblk_fs_type);
715 static inline int register_fuseblk(void)
720 static inline void unregister_fuseblk(void)
725 static decl_subsys(fuse, NULL, NULL);
726 static decl_subsys(connections, NULL, NULL);
728 static void fuse_inode_init_once(struct kmem_cache *cachep, void *foo)
730 struct inode * inode = foo;
732 inode_init_once(inode);
735 static int __init fuse_fs_init(void)
739 err = register_filesystem(&fuse_fs_type);
743 err = register_fuseblk();
747 fuse_inode_cachep = kmem_cache_create("fuse_inode",
748 sizeof(struct fuse_inode),
749 0, SLAB_HWCACHE_ALIGN,
750 fuse_inode_init_once);
752 if (!fuse_inode_cachep)
758 unregister_fuseblk();
760 unregister_filesystem(&fuse_fs_type);
765 static void fuse_fs_cleanup(void)
767 unregister_filesystem(&fuse_fs_type);
768 unregister_fuseblk();
769 kmem_cache_destroy(fuse_inode_cachep);
772 static int fuse_sysfs_init(void)
776 kobj_set_kset_s(&fuse_subsys, fs_subsys);
777 err = subsystem_register(&fuse_subsys);
781 kobj_set_kset_s(&connections_subsys, fuse_subsys);
782 err = subsystem_register(&connections_subsys);
784 goto out_fuse_unregister;
789 subsystem_unregister(&fuse_subsys);
794 static void fuse_sysfs_cleanup(void)
796 subsystem_unregister(&connections_subsys);
797 subsystem_unregister(&fuse_subsys);
800 static int __init fuse_init(void)
804 printk("fuse init (API version %i.%i)\n",
805 FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
807 INIT_LIST_HEAD(&fuse_conn_list);
808 res = fuse_fs_init();
812 res = fuse_dev_init();
816 res = fuse_sysfs_init();
818 goto err_dev_cleanup;
820 res = fuse_ctl_init();
822 goto err_sysfs_cleanup;
827 fuse_sysfs_cleanup();
836 static void __exit fuse_exit(void)
838 printk(KERN_DEBUG "fuse exit\n");
841 fuse_sysfs_cleanup();
846 module_init(fuse_init);
847 module_exit(fuse_exit);