2 FUSE: Filesystem in Userspace
3 Copyright (C) 2001-2005 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");
26 static kmem_cache_t *fuse_inode_cachep;
28 #define FUSE_SUPER_MAGIC 0x65735546
30 struct fuse_mount_data {
37 static struct inode *fuse_alloc_inode(struct super_block *sb)
40 struct fuse_inode *fi;
42 inode = kmem_cache_alloc(fuse_inode_cachep, SLAB_KERNEL);
46 fi = get_fuse_inode(inode);
47 fi->i_time = jiffies - 1;
50 fi->forget_req = fuse_request_alloc();
51 if (!fi->forget_req) {
52 kmem_cache_free(fuse_inode_cachep, inode);
59 static void fuse_destroy_inode(struct inode *inode)
61 struct fuse_inode *fi = get_fuse_inode(inode);
63 fuse_request_free(fi->forget_req);
64 kmem_cache_free(fuse_inode_cachep, inode);
67 static void fuse_read_inode(struct inode *inode)
72 void fuse_send_forget(struct fuse_conn *fc, struct fuse_req *req,
73 unsigned long nodeid, u64 nlookup)
75 struct fuse_forget_in *inarg = &req->misc.forget_in;
76 inarg->nlookup = nlookup;
77 req->in.h.opcode = FUSE_FORGET;
78 req->in.h.nodeid = nodeid;
80 req->in.args[0].size = sizeof(struct fuse_forget_in);
81 req->in.args[0].value = inarg;
82 request_send_noreply(fc, req);
85 static void fuse_clear_inode(struct inode *inode)
87 if (inode->i_sb->s_flags & MS_ACTIVE) {
88 struct fuse_conn *fc = get_fuse_conn(inode);
89 struct fuse_inode *fi = get_fuse_inode(inode);
90 fuse_send_forget(fc, fi->forget_req, fi->nodeid, fi->nlookup);
91 fi->forget_req = NULL;
95 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr)
97 if (S_ISREG(inode->i_mode) && i_size_read(inode) != attr->size)
98 invalidate_inode_pages(inode->i_mapping);
100 inode->i_ino = attr->ino;
101 inode->i_mode = (inode->i_mode & S_IFMT) + (attr->mode & 07777);
102 inode->i_nlink = attr->nlink;
103 inode->i_uid = attr->uid;
104 inode->i_gid = attr->gid;
105 i_size_write(inode, attr->size);
106 inode->i_blksize = PAGE_CACHE_SIZE;
107 inode->i_blocks = attr->blocks;
108 inode->i_atime.tv_sec = attr->atime;
109 inode->i_atime.tv_nsec = attr->atimensec;
110 inode->i_mtime.tv_sec = attr->mtime;
111 inode->i_mtime.tv_nsec = attr->mtimensec;
112 inode->i_ctime.tv_sec = attr->ctime;
113 inode->i_ctime.tv_nsec = attr->ctimensec;
116 static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
118 inode->i_mode = attr->mode & S_IFMT;
119 i_size_write(inode, attr->size);
120 if (S_ISREG(inode->i_mode)) {
121 fuse_init_common(inode);
122 fuse_init_file_inode(inode);
123 } else if (S_ISDIR(inode->i_mode))
124 fuse_init_dir(inode);
125 else if (S_ISLNK(inode->i_mode))
126 fuse_init_symlink(inode);
127 else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
128 S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
129 fuse_init_common(inode);
130 init_special_inode(inode, inode->i_mode,
131 new_decode_dev(attr->rdev));
133 /* Don't let user create weird files */
134 inode->i_mode = S_IFREG;
135 fuse_init_common(inode);
136 fuse_init_file_inode(inode);
140 static int fuse_inode_eq(struct inode *inode, void *_nodeidp)
142 unsigned long nodeid = *(unsigned long *) _nodeidp;
143 if (get_node_id(inode) == nodeid)
149 static int fuse_inode_set(struct inode *inode, void *_nodeidp)
151 unsigned long nodeid = *(unsigned long *) _nodeidp;
152 get_fuse_inode(inode)->nodeid = nodeid;
156 struct inode *fuse_iget(struct super_block *sb, unsigned long nodeid,
157 int generation, struct fuse_attr *attr)
160 struct fuse_inode *fi;
161 struct fuse_conn *fc = get_fuse_conn_super(sb);
165 inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid);
169 if ((inode->i_state & I_NEW)) {
170 inode->i_generation = generation;
171 inode->i_data.backing_dev_info = &fc->bdi;
172 fuse_init_inode(inode, attr);
173 unlock_new_inode(inode);
174 } else if ((inode->i_mode ^ attr->mode) & S_IFMT) {
176 /* Inode has changed type, any I/O on the old should fail */
177 make_bad_inode(inode);
183 fi = get_fuse_inode(inode);
185 fuse_change_attributes(inode, attr);
189 static void fuse_put_super(struct super_block *sb)
191 struct fuse_conn *fc = get_fuse_conn_super(sb);
193 down_write(&fc->sbput_sem);
194 while (!list_empty(&fc->background))
195 fuse_release_background(list_entry(fc->background.next,
196 struct fuse_req, bg_entry));
198 spin_lock(&fuse_lock);
202 /* Flush all readers on this fs */
203 wake_up_all(&fc->waitq);
204 up_write(&fc->sbput_sem);
205 fuse_release_conn(fc);
206 spin_unlock(&fuse_lock);
209 static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
211 stbuf->f_type = FUSE_SUPER_MAGIC;
212 stbuf->f_bsize = attr->bsize;
213 stbuf->f_blocks = attr->blocks;
214 stbuf->f_bfree = attr->bfree;
215 stbuf->f_bavail = attr->bavail;
216 stbuf->f_files = attr->files;
217 stbuf->f_ffree = attr->ffree;
218 stbuf->f_namelen = attr->namelen;
219 /* fsid is left zero */
222 static int fuse_statfs(struct super_block *sb, struct kstatfs *buf)
224 struct fuse_conn *fc = get_fuse_conn_super(sb);
225 struct fuse_req *req;
226 struct fuse_statfs_out outarg;
229 req = fuse_get_request(fc);
234 req->in.h.opcode = FUSE_STATFS;
235 req->out.numargs = 1;
236 req->out.args[0].size = sizeof(outarg);
237 req->out.args[0].value = &outarg;
238 request_send(fc, req);
239 err = req->out.h.error;
241 convert_fuse_statfs(buf, &outarg.st);
242 fuse_put_request(fc, req);
250 OPT_DEFAULT_PERMISSIONS,
256 static match_table_t tokens = {
258 {OPT_ROOTMODE, "rootmode=%o"},
259 {OPT_USER_ID, "user_id=%u"},
260 {OPT_DEFAULT_PERMISSIONS, "default_permissions"},
261 {OPT_ALLOW_OTHER, "allow_other"},
262 {OPT_KERNEL_CACHE, "kernel_cache"},
266 static int parse_fuse_opt(char *opt, struct fuse_mount_data *d)
269 memset(d, 0, sizeof(struct fuse_mount_data));
272 while ((p = strsep(&opt, ",")) != NULL) {
275 substring_t args[MAX_OPT_ARGS];
279 token = match_token(p, tokens, args);
282 if (match_int(&args[0], &value))
288 if (match_octal(&args[0], &value))
294 if (match_int(&args[0], &value))
299 case OPT_DEFAULT_PERMISSIONS:
300 d->flags |= FUSE_DEFAULT_PERMISSIONS;
303 case OPT_ALLOW_OTHER:
304 d->flags |= FUSE_ALLOW_OTHER;
307 case OPT_KERNEL_CACHE:
308 d->flags |= FUSE_KERNEL_CACHE;
321 static int fuse_show_options(struct seq_file *m, struct vfsmount *mnt)
323 struct fuse_conn *fc = get_fuse_conn_super(mnt->mnt_sb);
325 seq_printf(m, ",user_id=%u", fc->user_id);
326 if (fc->flags & FUSE_DEFAULT_PERMISSIONS)
327 seq_puts(m, ",default_permissions");
328 if (fc->flags & FUSE_ALLOW_OTHER)
329 seq_puts(m, ",allow_other");
330 if (fc->flags & FUSE_KERNEL_CACHE)
331 seq_puts(m, ",kernel_cache");
335 static void free_conn(struct fuse_conn *fc)
337 while (!list_empty(&fc->unused_list)) {
338 struct fuse_req *req;
339 req = list_entry(fc->unused_list.next, struct fuse_req, list);
340 list_del(&req->list);
341 fuse_request_free(req);
346 /* Must be called with the fuse lock held */
347 void fuse_release_conn(struct fuse_conn *fc)
354 static struct fuse_conn *new_conn(void)
356 struct fuse_conn *fc;
358 fc = kmalloc(sizeof(*fc), GFP_KERNEL);
361 memset(fc, 0, sizeof(*fc));
362 init_waitqueue_head(&fc->waitq);
363 INIT_LIST_HEAD(&fc->pending);
364 INIT_LIST_HEAD(&fc->processing);
365 INIT_LIST_HEAD(&fc->unused_list);
366 INIT_LIST_HEAD(&fc->background);
367 sema_init(&fc->outstanding_sem, 0);
368 init_rwsem(&fc->sbput_sem);
369 for (i = 0; i < FUSE_MAX_OUTSTANDING; i++) {
370 struct fuse_req *req = fuse_request_alloc();
375 list_add(&req->list, &fc->unused_list);
377 fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
378 fc->bdi.unplug_io_fn = default_unplug_io_fn;
384 static struct fuse_conn *get_conn(struct file *file, struct super_block *sb)
386 struct fuse_conn *fc;
388 if (file->f_op != &fuse_dev_operations)
389 return ERR_PTR(-EINVAL);
392 return ERR_PTR(-ENOMEM);
393 spin_lock(&fuse_lock);
394 if (file->private_data) {
396 fc = ERR_PTR(-EINVAL);
398 file->private_data = fc;
399 *get_fuse_conn_super_p(sb) = fc;
404 spin_unlock(&fuse_lock);
408 static struct inode *get_root_inode(struct super_block *sb, unsigned mode)
410 struct fuse_attr attr;
411 memset(&attr, 0, sizeof(attr));
414 attr.ino = FUSE_ROOT_ID;
415 return fuse_iget(sb, 1, 0, &attr);
418 static struct super_operations fuse_super_operations = {
419 .alloc_inode = fuse_alloc_inode,
420 .destroy_inode = fuse_destroy_inode,
421 .read_inode = fuse_read_inode,
422 .clear_inode = fuse_clear_inode,
423 .put_super = fuse_put_super,
424 .statfs = fuse_statfs,
425 .show_options = fuse_show_options,
428 static int fuse_fill_super(struct super_block *sb, void *data, int silent)
430 struct fuse_conn *fc;
432 struct fuse_mount_data d;
436 if (!parse_fuse_opt((char *) data, &d))
439 sb->s_blocksize = PAGE_CACHE_SIZE;
440 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
441 sb->s_magic = FUSE_SUPER_MAGIC;
442 sb->s_op = &fuse_super_operations;
443 sb->s_maxbytes = MAX_LFS_FILESIZE;
449 fc = get_conn(file, sb);
455 fc->user_id = d.user_id;
458 root = get_root_inode(sb, d.rootmode);
462 sb->s_root = d_alloc_root(root);
471 spin_lock(&fuse_lock);
472 fuse_release_conn(fc);
473 spin_unlock(&fuse_lock);
477 static struct super_block *fuse_get_sb(struct file_system_type *fs_type,
478 int flags, const char *dev_name,
481 return get_sb_nodev(fs_type, flags, raw_data, fuse_fill_super);
484 static struct file_system_type fuse_fs_type = {
485 .owner = THIS_MODULE,
487 .get_sb = fuse_get_sb,
488 .kill_sb = kill_anon_super,
491 static void fuse_inode_init_once(void *foo, kmem_cache_t *cachep,
494 struct inode * inode = foo;
496 if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
497 SLAB_CTOR_CONSTRUCTOR)
498 inode_init_once(inode);
501 static int __init fuse_fs_init(void)
505 err = register_filesystem(&fuse_fs_type);
507 printk("fuse: failed to register filesystem\n");
509 fuse_inode_cachep = kmem_cache_create("fuse_inode",
510 sizeof(struct fuse_inode),
511 0, SLAB_HWCACHE_ALIGN,
512 fuse_inode_init_once, NULL);
513 if (!fuse_inode_cachep) {
514 unregister_filesystem(&fuse_fs_type);
522 static void fuse_fs_cleanup(void)
524 unregister_filesystem(&fuse_fs_type);
525 kmem_cache_destroy(fuse_inode_cachep);
528 static int __init fuse_init(void)
532 printk("fuse init (API version %i.%i)\n",
533 FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
535 spin_lock_init(&fuse_lock);
536 res = fuse_fs_init();
540 res = fuse_dev_init();
552 static void __exit fuse_exit(void)
554 printk(KERN_DEBUG "fuse exit\n");
560 module_init(fuse_init);
561 module_exit(fuse_exit);