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/mount.h>
15 #include <linux/seq_file.h>
16 #include <linux/init.h>
17 #include <linux/module.h>
18 #include <linux/parser.h>
19 #include <linux/statfs.h>
21 MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>");
22 MODULE_DESCRIPTION("Filesystem in Userspace");
23 MODULE_LICENSE("GPL");
25 static kmem_cache_t *fuse_inode_cachep;
26 static struct subsystem connections_subsys;
28 struct fuse_conn_attr {
29 struct attribute attr;
30 ssize_t (*show)(struct fuse_conn *, char *);
31 ssize_t (*store)(struct fuse_conn *, const char *, size_t);
34 #define FUSE_SUPER_MAGIC 0x65735546
36 struct fuse_mount_data {
41 unsigned fd_present : 1;
42 unsigned rootmode_present : 1;
43 unsigned user_id_present : 1;
44 unsigned group_id_present : 1;
49 static struct inode *fuse_alloc_inode(struct super_block *sb)
52 struct fuse_inode *fi;
54 inode = kmem_cache_alloc(fuse_inode_cachep, SLAB_KERNEL);
58 fi = get_fuse_inode(inode);
59 fi->i_time = jiffies - 1;
62 fi->forget_req = fuse_request_alloc();
63 if (!fi->forget_req) {
64 kmem_cache_free(fuse_inode_cachep, inode);
71 static void fuse_destroy_inode(struct inode *inode)
73 struct fuse_inode *fi = get_fuse_inode(inode);
75 fuse_request_free(fi->forget_req);
76 kmem_cache_free(fuse_inode_cachep, inode);
79 static void fuse_read_inode(struct inode *inode)
84 void fuse_send_forget(struct fuse_conn *fc, struct fuse_req *req,
85 unsigned long nodeid, u64 nlookup)
87 struct fuse_forget_in *inarg = &req->misc.forget_in;
88 inarg->nlookup = nlookup;
89 req->in.h.opcode = FUSE_FORGET;
90 req->in.h.nodeid = nodeid;
92 req->in.args[0].size = sizeof(struct fuse_forget_in);
93 req->in.args[0].value = inarg;
94 request_send_noreply(fc, req);
97 static void fuse_clear_inode(struct inode *inode)
99 if (inode->i_sb->s_flags & MS_ACTIVE) {
100 struct fuse_conn *fc = get_fuse_conn(inode);
101 struct fuse_inode *fi = get_fuse_inode(inode);
102 fuse_send_forget(fc, fi->forget_req, fi->nodeid, fi->nlookup);
103 fi->forget_req = NULL;
107 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr)
109 if (S_ISREG(inode->i_mode) && i_size_read(inode) != attr->size)
110 invalidate_inode_pages(inode->i_mapping);
112 inode->i_ino = attr->ino;
113 inode->i_mode = (inode->i_mode & S_IFMT) + (attr->mode & 07777);
114 inode->i_nlink = attr->nlink;
115 inode->i_uid = attr->uid;
116 inode->i_gid = attr->gid;
117 i_size_write(inode, attr->size);
118 inode->i_blksize = PAGE_CACHE_SIZE;
119 inode->i_blocks = attr->blocks;
120 inode->i_atime.tv_sec = attr->atime;
121 inode->i_atime.tv_nsec = attr->atimensec;
122 inode->i_mtime.tv_sec = attr->mtime;
123 inode->i_mtime.tv_nsec = attr->mtimensec;
124 inode->i_ctime.tv_sec = attr->ctime;
125 inode->i_ctime.tv_nsec = attr->ctimensec;
128 static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
130 inode->i_mode = attr->mode & S_IFMT;
131 i_size_write(inode, attr->size);
132 if (S_ISREG(inode->i_mode)) {
133 fuse_init_common(inode);
134 fuse_init_file_inode(inode);
135 } else if (S_ISDIR(inode->i_mode))
136 fuse_init_dir(inode);
137 else if (S_ISLNK(inode->i_mode))
138 fuse_init_symlink(inode);
139 else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
140 S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
141 fuse_init_common(inode);
142 init_special_inode(inode, inode->i_mode,
143 new_decode_dev(attr->rdev));
148 static int fuse_inode_eq(struct inode *inode, void *_nodeidp)
150 unsigned long nodeid = *(unsigned long *) _nodeidp;
151 if (get_node_id(inode) == nodeid)
157 static int fuse_inode_set(struct inode *inode, void *_nodeidp)
159 unsigned long nodeid = *(unsigned long *) _nodeidp;
160 get_fuse_inode(inode)->nodeid = nodeid;
164 struct inode *fuse_iget(struct super_block *sb, unsigned long nodeid,
165 int generation, struct fuse_attr *attr)
168 struct fuse_inode *fi;
169 struct fuse_conn *fc = get_fuse_conn_super(sb);
173 inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid);
177 if ((inode->i_state & I_NEW)) {
178 inode->i_flags |= S_NOATIME|S_NOCMTIME;
179 inode->i_generation = generation;
180 inode->i_data.backing_dev_info = &fc->bdi;
181 fuse_init_inode(inode, attr);
182 unlock_new_inode(inode);
183 } else if ((inode->i_mode ^ attr->mode) & S_IFMT) {
185 /* Inode has changed type, any I/O on the old should fail */
186 make_bad_inode(inode);
192 fi = get_fuse_inode(inode);
194 fuse_change_attributes(inode, attr);
198 static void fuse_umount_begin(struct vfsmount *vfsmnt, int flags)
200 if (flags & MNT_FORCE)
201 fuse_abort_conn(get_fuse_conn_super(vfsmnt->mnt_sb));
204 static void fuse_put_super(struct super_block *sb)
206 struct fuse_conn *fc = get_fuse_conn_super(sb);
208 down_write(&fc->sbput_sem);
209 while (!list_empty(&fc->background))
210 fuse_release_background(fc,
211 list_entry(fc->background.next,
212 struct fuse_req, bg_entry));
214 spin_lock(&fc->lock);
217 spin_unlock(&fc->lock);
218 up_write(&fc->sbput_sem);
219 /* Flush all readers on this fs */
220 kill_fasync(&fc->fasync, SIGIO, POLL_IN);
221 wake_up_all(&fc->waitq);
222 kobject_del(&fc->kobj);
223 kobject_put(&fc->kobj);
226 static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
228 stbuf->f_type = FUSE_SUPER_MAGIC;
229 stbuf->f_bsize = attr->bsize;
230 stbuf->f_frsize = attr->frsize;
231 stbuf->f_blocks = attr->blocks;
232 stbuf->f_bfree = attr->bfree;
233 stbuf->f_bavail = attr->bavail;
234 stbuf->f_files = attr->files;
235 stbuf->f_ffree = attr->ffree;
236 stbuf->f_namelen = attr->namelen;
237 /* fsid is left zero */
240 static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf)
242 struct super_block *sb = dentry->d_sb;
243 struct fuse_conn *fc = get_fuse_conn_super(sb);
244 struct fuse_req *req;
245 struct fuse_statfs_out outarg;
248 req = fuse_get_req(fc);
252 memset(&outarg, 0, sizeof(outarg));
254 req->in.h.opcode = FUSE_STATFS;
255 req->out.numargs = 1;
256 req->out.args[0].size =
257 fc->minor < 4 ? FUSE_COMPAT_STATFS_SIZE : sizeof(outarg);
258 req->out.args[0].value = &outarg;
259 request_send(fc, req);
260 err = req->out.h.error;
262 convert_fuse_statfs(buf, &outarg.st);
263 fuse_put_request(fc, req);
272 OPT_DEFAULT_PERMISSIONS,
278 static match_table_t tokens = {
280 {OPT_ROOTMODE, "rootmode=%o"},
281 {OPT_USER_ID, "user_id=%u"},
282 {OPT_GROUP_ID, "group_id=%u"},
283 {OPT_DEFAULT_PERMISSIONS, "default_permissions"},
284 {OPT_ALLOW_OTHER, "allow_other"},
285 {OPT_MAX_READ, "max_read=%u"},
289 static int parse_fuse_opt(char *opt, struct fuse_mount_data *d)
292 memset(d, 0, sizeof(struct fuse_mount_data));
295 while ((p = strsep(&opt, ",")) != NULL) {
298 substring_t args[MAX_OPT_ARGS];
302 token = match_token(p, tokens, args);
305 if (match_int(&args[0], &value))
312 if (match_octal(&args[0], &value))
315 d->rootmode_present = 1;
319 if (match_int(&args[0], &value))
322 d->user_id_present = 1;
326 if (match_int(&args[0], &value))
329 d->group_id_present = 1;
332 case OPT_DEFAULT_PERMISSIONS:
333 d->flags |= FUSE_DEFAULT_PERMISSIONS;
336 case OPT_ALLOW_OTHER:
337 d->flags |= FUSE_ALLOW_OTHER;
341 if (match_int(&args[0], &value))
351 if (!d->fd_present || !d->rootmode_present ||
352 !d->user_id_present || !d->group_id_present)
358 static int fuse_show_options(struct seq_file *m, struct vfsmount *mnt)
360 struct fuse_conn *fc = get_fuse_conn_super(mnt->mnt_sb);
362 seq_printf(m, ",user_id=%u", fc->user_id);
363 seq_printf(m, ",group_id=%u", fc->group_id);
364 if (fc->flags & FUSE_DEFAULT_PERMISSIONS)
365 seq_puts(m, ",default_permissions");
366 if (fc->flags & FUSE_ALLOW_OTHER)
367 seq_puts(m, ",allow_other");
368 if (fc->max_read != ~0)
369 seq_printf(m, ",max_read=%u", fc->max_read);
373 static void fuse_conn_release(struct kobject *kobj)
375 kfree(get_fuse_conn_kobj(kobj));
378 static struct fuse_conn *new_conn(void)
380 struct fuse_conn *fc;
382 fc = kzalloc(sizeof(*fc), GFP_KERNEL);
384 spin_lock_init(&fc->lock);
385 init_waitqueue_head(&fc->waitq);
386 init_waitqueue_head(&fc->blocked_waitq);
387 INIT_LIST_HEAD(&fc->pending);
388 INIT_LIST_HEAD(&fc->processing);
389 INIT_LIST_HEAD(&fc->io);
390 INIT_LIST_HEAD(&fc->background);
391 init_rwsem(&fc->sbput_sem);
392 kobj_set_kset_s(fc, connections_subsys);
393 kobject_init(&fc->kobj);
394 atomic_set(&fc->num_waiting, 0);
395 fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
396 fc->bdi.unplug_io_fn = default_unplug_io_fn;
403 static struct inode *get_root_inode(struct super_block *sb, unsigned mode)
405 struct fuse_attr attr;
406 memset(&attr, 0, sizeof(attr));
409 attr.ino = FUSE_ROOT_ID;
410 return fuse_iget(sb, 1, 0, &attr);
413 static struct super_operations fuse_super_operations = {
414 .alloc_inode = fuse_alloc_inode,
415 .destroy_inode = fuse_destroy_inode,
416 .read_inode = fuse_read_inode,
417 .clear_inode = fuse_clear_inode,
418 .put_super = fuse_put_super,
419 .umount_begin = fuse_umount_begin,
420 .statfs = fuse_statfs,
421 .show_options = fuse_show_options,
424 static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
426 struct fuse_init_out *arg = &req->misc.init_out;
428 if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION)
431 unsigned long ra_pages;
433 if (arg->minor >= 6) {
434 ra_pages = arg->max_readahead / PAGE_CACHE_SIZE;
435 if (arg->flags & FUSE_ASYNC_READ)
438 ra_pages = fc->max_read / PAGE_CACHE_SIZE;
440 fc->bdi.ra_pages = min(fc->bdi.ra_pages, ra_pages);
441 fc->minor = arg->minor;
442 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
444 fuse_put_request(fc, req);
446 wake_up_all(&fc->blocked_waitq);
449 static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req)
451 struct fuse_init_in *arg = &req->misc.init_in;
453 arg->major = FUSE_KERNEL_VERSION;
454 arg->minor = FUSE_KERNEL_MINOR_VERSION;
455 arg->max_readahead = fc->bdi.ra_pages * PAGE_CACHE_SIZE;
456 arg->flags |= FUSE_ASYNC_READ;
457 req->in.h.opcode = FUSE_INIT;
459 req->in.args[0].size = sizeof(*arg);
460 req->in.args[0].value = arg;
461 req->out.numargs = 1;
462 /* Variable length arguement used for backward compatibility
463 with interface version < 7.5. Rest of init_out is zeroed
464 by do_get_request(), so a short reply is not a problem */
466 req->out.args[0].size = sizeof(struct fuse_init_out);
467 req->out.args[0].value = &req->misc.init_out;
468 req->end = process_init_reply;
469 request_send_background(fc, req);
472 static unsigned long long conn_id(void)
474 /* BKL is held for ->get_sb() */
475 static unsigned long long ctr = 1;
479 static int fuse_fill_super(struct super_block *sb, void *data, int silent)
481 struct fuse_conn *fc;
483 struct fuse_mount_data d;
485 struct dentry *root_dentry;
486 struct fuse_req *init_req;
489 if (!parse_fuse_opt((char *) data, &d))
492 sb->s_blocksize = PAGE_CACHE_SIZE;
493 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
494 sb->s_magic = FUSE_SUPER_MAGIC;
495 sb->s_op = &fuse_super_operations;
496 sb->s_maxbytes = MAX_LFS_FILESIZE;
502 if (file->f_op != &fuse_dev_operations)
510 fc->user_id = d.user_id;
511 fc->group_id = d.group_id;
512 fc->max_read = d.max_read;
514 /* Used by get_root_inode() */
518 root = get_root_inode(sb, d.rootmode);
522 root_dentry = d_alloc_root(root);
528 init_req = fuse_request_alloc();
532 err = kobject_set_name(&fc->kobj, "%llu", conn_id());
536 err = kobject_add(&fc->kobj);
540 /* Setting file->private_data can't race with other mount()
541 instances, since BKL is held for ->get_sb() */
543 if (file->private_data)
544 goto err_kobject_del;
546 sb->s_root = root_dentry;
549 kobject_get(&fc->kobj);
550 file->private_data = fc;
552 * atomic_dec_and_test() in fput() provides the necessary
553 * memory barrier for file->private_data to be visible on all
558 fuse_send_init(fc, init_req);
563 kobject_del(&fc->kobj);
565 fuse_request_free(init_req);
570 kobject_put(&fc->kobj);
574 static int fuse_get_sb(struct file_system_type *fs_type,
575 int flags, const char *dev_name,
576 void *raw_data, struct vfsmount *mnt)
578 return get_sb_nodev(fs_type, flags, raw_data, fuse_fill_super, mnt);
581 static struct file_system_type fuse_fs_type = {
582 .owner = THIS_MODULE,
584 .get_sb = fuse_get_sb,
585 .kill_sb = kill_anon_super,
588 static ssize_t fuse_conn_waiting_show(struct fuse_conn *fc, char *page)
590 return sprintf(page, "%i\n", atomic_read(&fc->num_waiting));
593 static ssize_t fuse_conn_abort_store(struct fuse_conn *fc, const char *page,
600 static struct fuse_conn_attr fuse_conn_waiting =
601 __ATTR(waiting, 0400, fuse_conn_waiting_show, NULL);
602 static struct fuse_conn_attr fuse_conn_abort =
603 __ATTR(abort, 0600, NULL, fuse_conn_abort_store);
605 static struct attribute *fuse_conn_attrs[] = {
606 &fuse_conn_waiting.attr,
607 &fuse_conn_abort.attr,
611 static ssize_t fuse_conn_attr_show(struct kobject *kobj,
612 struct attribute *attr,
615 struct fuse_conn_attr *fca =
616 container_of(attr, struct fuse_conn_attr, attr);
619 return fca->show(get_fuse_conn_kobj(kobj), page);
624 static ssize_t fuse_conn_attr_store(struct kobject *kobj,
625 struct attribute *attr,
626 const char *page, size_t count)
628 struct fuse_conn_attr *fca =
629 container_of(attr, struct fuse_conn_attr, attr);
632 return fca->store(get_fuse_conn_kobj(kobj), page, count);
637 static struct sysfs_ops fuse_conn_sysfs_ops = {
638 .show = &fuse_conn_attr_show,
639 .store = &fuse_conn_attr_store,
642 static struct kobj_type ktype_fuse_conn = {
643 .release = fuse_conn_release,
644 .sysfs_ops = &fuse_conn_sysfs_ops,
645 .default_attrs = fuse_conn_attrs,
648 static decl_subsys(fuse, NULL, NULL);
649 static decl_subsys(connections, &ktype_fuse_conn, NULL);
651 static void fuse_inode_init_once(void *foo, kmem_cache_t *cachep,
654 struct inode * inode = foo;
656 if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
657 SLAB_CTOR_CONSTRUCTOR)
658 inode_init_once(inode);
661 static int __init fuse_fs_init(void)
665 err = register_filesystem(&fuse_fs_type);
667 printk("fuse: failed to register filesystem\n");
669 fuse_inode_cachep = kmem_cache_create("fuse_inode",
670 sizeof(struct fuse_inode),
671 0, SLAB_HWCACHE_ALIGN,
672 fuse_inode_init_once, NULL);
673 if (!fuse_inode_cachep) {
674 unregister_filesystem(&fuse_fs_type);
682 static void fuse_fs_cleanup(void)
684 unregister_filesystem(&fuse_fs_type);
685 kmem_cache_destroy(fuse_inode_cachep);
688 static int fuse_sysfs_init(void)
692 kset_set_kset_s(&fuse_subsys, fs_subsys);
693 err = subsystem_register(&fuse_subsys);
697 kset_set_kset_s(&connections_subsys, fuse_subsys);
698 err = subsystem_register(&connections_subsys);
700 goto out_fuse_unregister;
705 subsystem_unregister(&fuse_subsys);
710 static void fuse_sysfs_cleanup(void)
712 subsystem_unregister(&connections_subsys);
713 subsystem_unregister(&fuse_subsys);
716 static int __init fuse_init(void)
720 printk("fuse init (API version %i.%i)\n",
721 FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
723 res = fuse_fs_init();
727 res = fuse_dev_init();
731 res = fuse_sysfs_init();
733 goto err_dev_cleanup;
745 static void __exit fuse_exit(void)
747 printk(KERN_DEBUG "fuse exit\n");
749 fuse_sysfs_cleanup();
754 module_init(fuse_init);
755 module_exit(fuse_exit);