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>
20 MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>");
21 MODULE_DESCRIPTION("Filesystem in Userspace");
22 MODULE_LICENSE("GPL");
24 static kmem_cache_t *fuse_inode_cachep;
25 struct list_head fuse_conn_list;
26 DEFINE_MUTEX(fuse_mutex);
28 #define FUSE_SUPER_MAGIC 0x65735546
30 struct fuse_mount_data {
35 unsigned fd_present : 1;
36 unsigned rootmode_present : 1;
37 unsigned user_id_present : 1;
38 unsigned group_id_present : 1;
43 static struct inode *fuse_alloc_inode(struct super_block *sb)
46 struct fuse_inode *fi;
48 inode = kmem_cache_alloc(fuse_inode_cachep, SLAB_KERNEL);
52 fi = get_fuse_inode(inode);
53 fi->i_time = jiffies - 1;
56 fi->forget_req = fuse_request_alloc();
57 if (!fi->forget_req) {
58 kmem_cache_free(fuse_inode_cachep, inode);
65 static void fuse_destroy_inode(struct inode *inode)
67 struct fuse_inode *fi = get_fuse_inode(inode);
69 fuse_request_free(fi->forget_req);
70 kmem_cache_free(fuse_inode_cachep, inode);
73 static void fuse_read_inode(struct inode *inode)
78 void fuse_send_forget(struct fuse_conn *fc, struct fuse_req *req,
79 unsigned long nodeid, u64 nlookup)
81 struct fuse_forget_in *inarg = &req->misc.forget_in;
82 inarg->nlookup = nlookup;
83 req->in.h.opcode = FUSE_FORGET;
84 req->in.h.nodeid = nodeid;
86 req->in.args[0].size = sizeof(struct fuse_forget_in);
87 req->in.args[0].value = inarg;
88 request_send_noreply(fc, req);
91 static void fuse_clear_inode(struct inode *inode)
93 if (inode->i_sb->s_flags & MS_ACTIVE) {
94 struct fuse_conn *fc = get_fuse_conn(inode);
95 struct fuse_inode *fi = get_fuse_inode(inode);
96 fuse_send_forget(fc, fi->forget_req, fi->nodeid, fi->nlookup);
97 fi->forget_req = NULL;
101 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr)
103 if (S_ISREG(inode->i_mode) && i_size_read(inode) != attr->size)
104 invalidate_inode_pages(inode->i_mapping);
106 inode->i_ino = attr->ino;
107 inode->i_mode = (inode->i_mode & S_IFMT) + (attr->mode & 07777);
108 inode->i_nlink = attr->nlink;
109 inode->i_uid = attr->uid;
110 inode->i_gid = attr->gid;
111 i_size_write(inode, attr->size);
112 inode->i_blksize = PAGE_CACHE_SIZE;
113 inode->i_blocks = attr->blocks;
114 inode->i_atime.tv_sec = attr->atime;
115 inode->i_atime.tv_nsec = attr->atimensec;
116 inode->i_mtime.tv_sec = attr->mtime;
117 inode->i_mtime.tv_nsec = attr->mtimensec;
118 inode->i_ctime.tv_sec = attr->ctime;
119 inode->i_ctime.tv_nsec = attr->ctimensec;
122 static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
124 inode->i_mode = attr->mode & S_IFMT;
125 i_size_write(inode, attr->size);
126 if (S_ISREG(inode->i_mode)) {
127 fuse_init_common(inode);
128 fuse_init_file_inode(inode);
129 } else if (S_ISDIR(inode->i_mode))
130 fuse_init_dir(inode);
131 else if (S_ISLNK(inode->i_mode))
132 fuse_init_symlink(inode);
133 else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
134 S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
135 fuse_init_common(inode);
136 init_special_inode(inode, inode->i_mode,
137 new_decode_dev(attr->rdev));
142 static int fuse_inode_eq(struct inode *inode, void *_nodeidp)
144 unsigned long nodeid = *(unsigned long *) _nodeidp;
145 if (get_node_id(inode) == nodeid)
151 static int fuse_inode_set(struct inode *inode, void *_nodeidp)
153 unsigned long nodeid = *(unsigned long *) _nodeidp;
154 get_fuse_inode(inode)->nodeid = nodeid;
158 struct inode *fuse_iget(struct super_block *sb, unsigned long nodeid,
159 int generation, struct fuse_attr *attr)
162 struct fuse_inode *fi;
163 struct fuse_conn *fc = get_fuse_conn_super(sb);
167 inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid);
171 if ((inode->i_state & I_NEW)) {
172 inode->i_flags |= S_NOATIME|S_NOCMTIME;
173 inode->i_generation = generation;
174 inode->i_data.backing_dev_info = &fc->bdi;
175 fuse_init_inode(inode, attr);
176 unlock_new_inode(inode);
177 } else if ((inode->i_mode ^ attr->mode) & S_IFMT) {
179 /* Inode has changed type, any I/O on the old should fail */
180 make_bad_inode(inode);
186 fi = get_fuse_inode(inode);
188 fuse_change_attributes(inode, attr);
192 static void fuse_umount_begin(struct super_block *sb)
194 fuse_abort_conn(get_fuse_conn_super(sb));
197 static void fuse_put_super(struct super_block *sb)
199 struct fuse_conn *fc = get_fuse_conn_super(sb);
201 spin_lock(&fc->lock);
204 spin_unlock(&fc->lock);
205 /* Flush all readers on this fs */
206 kill_fasync(&fc->fasync, SIGIO, POLL_IN);
207 wake_up_all(&fc->waitq);
208 wake_up_all(&fc->blocked_waitq);
209 mutex_lock(&fuse_mutex);
210 list_del(&fc->entry);
211 fuse_ctl_remove_conn(fc);
212 mutex_unlock(&fuse_mutex);
216 static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
218 stbuf->f_type = FUSE_SUPER_MAGIC;
219 stbuf->f_bsize = attr->bsize;
220 stbuf->f_frsize = attr->frsize;
221 stbuf->f_blocks = attr->blocks;
222 stbuf->f_bfree = attr->bfree;
223 stbuf->f_bavail = attr->bavail;
224 stbuf->f_files = attr->files;
225 stbuf->f_ffree = attr->ffree;
226 stbuf->f_namelen = attr->namelen;
227 /* fsid is left zero */
230 static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf)
232 struct super_block *sb = dentry->d_sb;
233 struct fuse_conn *fc = get_fuse_conn_super(sb);
234 struct fuse_req *req;
235 struct fuse_statfs_out outarg;
238 req = fuse_get_req(fc);
242 memset(&outarg, 0, sizeof(outarg));
244 req->in.h.opcode = FUSE_STATFS;
245 req->out.numargs = 1;
246 req->out.args[0].size =
247 fc->minor < 4 ? FUSE_COMPAT_STATFS_SIZE : sizeof(outarg);
248 req->out.args[0].value = &outarg;
249 request_send(fc, req);
250 err = req->out.h.error;
252 convert_fuse_statfs(buf, &outarg.st);
253 fuse_put_request(fc, req);
262 OPT_DEFAULT_PERMISSIONS,
268 static match_table_t tokens = {
270 {OPT_ROOTMODE, "rootmode=%o"},
271 {OPT_USER_ID, "user_id=%u"},
272 {OPT_GROUP_ID, "group_id=%u"},
273 {OPT_DEFAULT_PERMISSIONS, "default_permissions"},
274 {OPT_ALLOW_OTHER, "allow_other"},
275 {OPT_MAX_READ, "max_read=%u"},
279 static int parse_fuse_opt(char *opt, struct fuse_mount_data *d)
282 memset(d, 0, sizeof(struct fuse_mount_data));
285 while ((p = strsep(&opt, ",")) != NULL) {
288 substring_t args[MAX_OPT_ARGS];
292 token = match_token(p, tokens, args);
295 if (match_int(&args[0], &value))
302 if (match_octal(&args[0], &value))
305 d->rootmode_present = 1;
309 if (match_int(&args[0], &value))
312 d->user_id_present = 1;
316 if (match_int(&args[0], &value))
319 d->group_id_present = 1;
322 case OPT_DEFAULT_PERMISSIONS:
323 d->flags |= FUSE_DEFAULT_PERMISSIONS;
326 case OPT_ALLOW_OTHER:
327 d->flags |= FUSE_ALLOW_OTHER;
331 if (match_int(&args[0], &value))
341 if (!d->fd_present || !d->rootmode_present ||
342 !d->user_id_present || !d->group_id_present)
348 static int fuse_show_options(struct seq_file *m, struct vfsmount *mnt)
350 struct fuse_conn *fc = get_fuse_conn_super(mnt->mnt_sb);
352 seq_printf(m, ",user_id=%u", fc->user_id);
353 seq_printf(m, ",group_id=%u", fc->group_id);
354 if (fc->flags & FUSE_DEFAULT_PERMISSIONS)
355 seq_puts(m, ",default_permissions");
356 if (fc->flags & FUSE_ALLOW_OTHER)
357 seq_puts(m, ",allow_other");
358 if (fc->max_read != ~0)
359 seq_printf(m, ",max_read=%u", fc->max_read);
363 static struct fuse_conn *new_conn(void)
365 struct fuse_conn *fc;
367 fc = kzalloc(sizeof(*fc), GFP_KERNEL);
369 spin_lock_init(&fc->lock);
370 atomic_set(&fc->count, 1);
371 init_waitqueue_head(&fc->waitq);
372 init_waitqueue_head(&fc->blocked_waitq);
373 INIT_LIST_HEAD(&fc->pending);
374 INIT_LIST_HEAD(&fc->processing);
375 INIT_LIST_HEAD(&fc->io);
376 atomic_set(&fc->num_waiting, 0);
377 fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
378 fc->bdi.unplug_io_fn = default_unplug_io_fn;
385 void fuse_conn_put(struct fuse_conn *fc)
387 if (atomic_dec_and_test(&fc->count))
391 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc)
393 atomic_inc(&fc->count);
397 static struct inode *get_root_inode(struct super_block *sb, unsigned mode)
399 struct fuse_attr attr;
400 memset(&attr, 0, sizeof(attr));
403 attr.ino = FUSE_ROOT_ID;
404 return fuse_iget(sb, 1, 0, &attr);
407 static struct super_operations fuse_super_operations = {
408 .alloc_inode = fuse_alloc_inode,
409 .destroy_inode = fuse_destroy_inode,
410 .read_inode = fuse_read_inode,
411 .clear_inode = fuse_clear_inode,
412 .put_super = fuse_put_super,
413 .umount_begin = fuse_umount_begin,
414 .statfs = fuse_statfs,
415 .show_options = fuse_show_options,
418 static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
420 struct fuse_init_out *arg = &req->misc.init_out;
422 if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION)
425 unsigned long ra_pages;
427 if (arg->minor >= 6) {
428 ra_pages = arg->max_readahead / PAGE_CACHE_SIZE;
429 if (arg->flags & FUSE_ASYNC_READ)
432 ra_pages = fc->max_read / PAGE_CACHE_SIZE;
434 fc->bdi.ra_pages = min(fc->bdi.ra_pages, ra_pages);
435 fc->minor = arg->minor;
436 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
438 fuse_put_request(fc, req);
440 wake_up_all(&fc->blocked_waitq);
443 static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req)
445 struct fuse_init_in *arg = &req->misc.init_in;
447 arg->major = FUSE_KERNEL_VERSION;
448 arg->minor = FUSE_KERNEL_MINOR_VERSION;
449 arg->max_readahead = fc->bdi.ra_pages * PAGE_CACHE_SIZE;
450 arg->flags |= FUSE_ASYNC_READ;
451 req->in.h.opcode = FUSE_INIT;
453 req->in.args[0].size = sizeof(*arg);
454 req->in.args[0].value = arg;
455 req->out.numargs = 1;
456 /* Variable length arguement used for backward compatibility
457 with interface version < 7.5. Rest of init_out is zeroed
458 by do_get_request(), so a short reply is not a problem */
460 req->out.args[0].size = sizeof(struct fuse_init_out);
461 req->out.args[0].value = &req->misc.init_out;
462 req->end = process_init_reply;
463 request_send_background(fc, req);
466 static u64 conn_id(void)
472 static int fuse_fill_super(struct super_block *sb, void *data, int silent)
474 struct fuse_conn *fc;
476 struct fuse_mount_data d;
478 struct dentry *root_dentry;
479 struct fuse_req *init_req;
482 if (!parse_fuse_opt((char *) data, &d))
485 sb->s_blocksize = PAGE_CACHE_SIZE;
486 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
487 sb->s_magic = FUSE_SUPER_MAGIC;
488 sb->s_op = &fuse_super_operations;
489 sb->s_maxbytes = MAX_LFS_FILESIZE;
495 if (file->f_op != &fuse_dev_operations)
503 fc->user_id = d.user_id;
504 fc->group_id = d.group_id;
505 fc->max_read = d.max_read;
507 /* Used by get_root_inode() */
511 root = get_root_inode(sb, d.rootmode);
515 root_dentry = d_alloc_root(root);
521 init_req = fuse_request_alloc();
525 mutex_lock(&fuse_mutex);
527 if (file->private_data)
531 err = fuse_ctl_add_conn(fc);
535 list_add_tail(&fc->entry, &fuse_conn_list);
536 sb->s_root = root_dentry;
538 file->private_data = fuse_conn_get(fc);
539 mutex_unlock(&fuse_mutex);
541 * atomic_dec_and_test() in fput() provides the necessary
542 * memory barrier for file->private_data to be visible on all
547 fuse_send_init(fc, init_req);
552 mutex_unlock(&fuse_mutex);
553 fuse_request_free(init_req);
562 static int fuse_get_sb(struct file_system_type *fs_type,
563 int flags, const char *dev_name,
564 void *raw_data, struct vfsmount *mnt)
566 return get_sb_nodev(fs_type, flags, raw_data, fuse_fill_super, mnt);
569 static struct file_system_type fuse_fs_type = {
570 .owner = THIS_MODULE,
572 .get_sb = fuse_get_sb,
573 .kill_sb = kill_anon_super,
576 static decl_subsys(fuse, NULL, NULL);
577 static decl_subsys(connections, NULL, NULL);
579 static void fuse_inode_init_once(void *foo, kmem_cache_t *cachep,
582 struct inode * inode = foo;
584 if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
585 SLAB_CTOR_CONSTRUCTOR)
586 inode_init_once(inode);
589 static int __init fuse_fs_init(void)
593 err = register_filesystem(&fuse_fs_type);
595 printk("fuse: failed to register filesystem\n");
597 fuse_inode_cachep = kmem_cache_create("fuse_inode",
598 sizeof(struct fuse_inode),
599 0, SLAB_HWCACHE_ALIGN,
600 fuse_inode_init_once, NULL);
601 if (!fuse_inode_cachep) {
602 unregister_filesystem(&fuse_fs_type);
610 static void fuse_fs_cleanup(void)
612 unregister_filesystem(&fuse_fs_type);
613 kmem_cache_destroy(fuse_inode_cachep);
616 static int fuse_sysfs_init(void)
620 kset_set_kset_s(&fuse_subsys, fs_subsys);
621 err = subsystem_register(&fuse_subsys);
625 kset_set_kset_s(&connections_subsys, fuse_subsys);
626 err = subsystem_register(&connections_subsys);
628 goto out_fuse_unregister;
633 subsystem_unregister(&fuse_subsys);
638 static void fuse_sysfs_cleanup(void)
640 subsystem_unregister(&connections_subsys);
641 subsystem_unregister(&fuse_subsys);
644 static int __init fuse_init(void)
648 printk("fuse init (API version %i.%i)\n",
649 FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
651 INIT_LIST_HEAD(&fuse_conn_list);
652 res = fuse_fs_init();
656 res = fuse_dev_init();
660 res = fuse_sysfs_init();
662 goto err_dev_cleanup;
664 res = fuse_ctl_init();
666 goto err_sysfs_cleanup;
671 fuse_sysfs_cleanup();
680 static void __exit fuse_exit(void)
682 printk(KERN_DEBUG "fuse exit\n");
685 fuse_sysfs_cleanup();
690 module_init(fuse_init);
691 module_exit(fuse_exit);