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>
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 struct list_head fuse_conn_list
;
27 DEFINE_MUTEX(fuse_mutex
);
29 #define FUSE_SUPER_MAGIC 0x65735546
31 struct fuse_mount_data
{
36 unsigned fd_present
: 1;
37 unsigned rootmode_present
: 1;
38 unsigned user_id_present
: 1;
39 unsigned group_id_present
: 1;
44 static struct inode
*fuse_alloc_inode(struct super_block
*sb
)
47 struct fuse_inode
*fi
;
49 inode
= kmem_cache_alloc(fuse_inode_cachep
, SLAB_KERNEL
);
53 fi
= get_fuse_inode(inode
);
57 fi
->forget_req
= fuse_request_alloc();
58 if (!fi
->forget_req
) {
59 kmem_cache_free(fuse_inode_cachep
, inode
);
66 static void fuse_destroy_inode(struct inode
*inode
)
68 struct fuse_inode
*fi
= get_fuse_inode(inode
);
70 fuse_request_free(fi
->forget_req
);
71 kmem_cache_free(fuse_inode_cachep
, inode
);
74 static void fuse_read_inode(struct inode
*inode
)
79 void fuse_send_forget(struct fuse_conn
*fc
, struct fuse_req
*req
,
80 unsigned long nodeid
, u64 nlookup
)
82 struct fuse_forget_in
*inarg
= &req
->misc
.forget_in
;
83 inarg
->nlookup
= nlookup
;
84 req
->in
.h
.opcode
= FUSE_FORGET
;
85 req
->in
.h
.nodeid
= nodeid
;
87 req
->in
.args
[0].size
= sizeof(struct fuse_forget_in
);
88 req
->in
.args
[0].value
= inarg
;
89 request_send_noreply(fc
, req
);
92 static void fuse_clear_inode(struct inode
*inode
)
94 if (inode
->i_sb
->s_flags
& MS_ACTIVE
) {
95 struct fuse_conn
*fc
= get_fuse_conn(inode
);
96 struct fuse_inode
*fi
= get_fuse_inode(inode
);
97 fuse_send_forget(fc
, fi
->forget_req
, fi
->nodeid
, fi
->nlookup
);
98 fi
->forget_req
= NULL
;
102 static int fuse_remount_fs(struct super_block
*sb
, int *flags
, char *data
)
104 if (*flags
& MS_MANDLOCK
)
110 void fuse_change_attributes(struct inode
*inode
, struct fuse_attr
*attr
)
112 struct fuse_conn
*fc
= get_fuse_conn(inode
);
113 if (S_ISREG(inode
->i_mode
) && i_size_read(inode
) != attr
->size
)
114 invalidate_inode_pages(inode
->i_mapping
);
116 inode
->i_ino
= attr
->ino
;
117 inode
->i_mode
= (inode
->i_mode
& S_IFMT
) + (attr
->mode
& 07777);
118 inode
->i_nlink
= attr
->nlink
;
119 inode
->i_uid
= attr
->uid
;
120 inode
->i_gid
= attr
->gid
;
121 spin_lock(&fc
->lock
);
122 i_size_write(inode
, attr
->size
);
123 spin_unlock(&fc
->lock
);
124 inode
->i_blocks
= attr
->blocks
;
125 inode
->i_atime
.tv_sec
= attr
->atime
;
126 inode
->i_atime
.tv_nsec
= attr
->atimensec
;
127 inode
->i_mtime
.tv_sec
= attr
->mtime
;
128 inode
->i_mtime
.tv_nsec
= attr
->mtimensec
;
129 inode
->i_ctime
.tv_sec
= attr
->ctime
;
130 inode
->i_ctime
.tv_nsec
= attr
->ctimensec
;
133 static void fuse_init_inode(struct inode
*inode
, struct fuse_attr
*attr
)
135 inode
->i_mode
= attr
->mode
& S_IFMT
;
136 inode
->i_size
= attr
->size
;
137 if (S_ISREG(inode
->i_mode
)) {
138 fuse_init_common(inode
);
139 fuse_init_file_inode(inode
);
140 } else if (S_ISDIR(inode
->i_mode
))
141 fuse_init_dir(inode
);
142 else if (S_ISLNK(inode
->i_mode
))
143 fuse_init_symlink(inode
);
144 else if (S_ISCHR(inode
->i_mode
) || S_ISBLK(inode
->i_mode
) ||
145 S_ISFIFO(inode
->i_mode
) || S_ISSOCK(inode
->i_mode
)) {
146 fuse_init_common(inode
);
147 init_special_inode(inode
, inode
->i_mode
,
148 new_decode_dev(attr
->rdev
));
153 static int fuse_inode_eq(struct inode
*inode
, void *_nodeidp
)
155 unsigned long nodeid
= *(unsigned long *) _nodeidp
;
156 if (get_node_id(inode
) == nodeid
)
162 static int fuse_inode_set(struct inode
*inode
, void *_nodeidp
)
164 unsigned long nodeid
= *(unsigned long *) _nodeidp
;
165 get_fuse_inode(inode
)->nodeid
= nodeid
;
169 struct inode
*fuse_iget(struct super_block
*sb
, unsigned long nodeid
,
170 int generation
, struct fuse_attr
*attr
)
173 struct fuse_inode
*fi
;
174 struct fuse_conn
*fc
= get_fuse_conn_super(sb
);
177 inode
= iget5_locked(sb
, nodeid
, fuse_inode_eq
, fuse_inode_set
, &nodeid
);
181 if ((inode
->i_state
& I_NEW
)) {
182 inode
->i_flags
|= S_NOATIME
|S_NOCMTIME
;
183 inode
->i_generation
= generation
;
184 inode
->i_data
.backing_dev_info
= &fc
->bdi
;
185 fuse_init_inode(inode
, attr
);
186 unlock_new_inode(inode
);
187 } else if ((inode
->i_mode
^ attr
->mode
) & S_IFMT
) {
188 /* Inode has changed type, any I/O on the old should fail */
189 make_bad_inode(inode
);
194 fi
= get_fuse_inode(inode
);
195 spin_lock(&fc
->lock
);
197 spin_unlock(&fc
->lock
);
198 fuse_change_attributes(inode
, attr
);
202 static void fuse_umount_begin(struct vfsmount
*vfsmnt
, int flags
)
204 if (flags
& MNT_FORCE
)
205 fuse_abort_conn(get_fuse_conn_super(vfsmnt
->mnt_sb
));
208 static void fuse_put_super(struct super_block
*sb
)
210 struct fuse_conn
*fc
= get_fuse_conn_super(sb
);
212 spin_lock(&fc
->lock
);
215 spin_unlock(&fc
->lock
);
216 /* Flush all readers on this fs */
217 kill_fasync(&fc
->fasync
, SIGIO
, POLL_IN
);
218 wake_up_all(&fc
->waitq
);
219 wake_up_all(&fc
->blocked_waitq
);
220 mutex_lock(&fuse_mutex
);
221 list_del(&fc
->entry
);
222 fuse_ctl_remove_conn(fc
);
223 mutex_unlock(&fuse_mutex
);
227 static void convert_fuse_statfs(struct kstatfs
*stbuf
, struct fuse_kstatfs
*attr
)
229 stbuf
->f_type
= FUSE_SUPER_MAGIC
;
230 stbuf
->f_bsize
= attr
->bsize
;
231 stbuf
->f_frsize
= attr
->frsize
;
232 stbuf
->f_blocks
= attr
->blocks
;
233 stbuf
->f_bfree
= attr
->bfree
;
234 stbuf
->f_bavail
= attr
->bavail
;
235 stbuf
->f_files
= attr
->files
;
236 stbuf
->f_ffree
= attr
->ffree
;
237 stbuf
->f_namelen
= attr
->namelen
;
238 /* fsid is left zero */
241 static int fuse_statfs(struct dentry
*dentry
, struct kstatfs
*buf
)
243 struct super_block
*sb
= dentry
->d_sb
;
244 struct fuse_conn
*fc
= get_fuse_conn_super(sb
);
245 struct fuse_req
*req
;
246 struct fuse_statfs_out outarg
;
249 req
= fuse_get_req(fc
);
253 memset(&outarg
, 0, sizeof(outarg
));
255 req
->in
.h
.opcode
= FUSE_STATFS
;
256 req
->in
.h
.nodeid
= get_node_id(dentry
->d_inode
);
257 req
->out
.numargs
= 1;
258 req
->out
.args
[0].size
=
259 fc
->minor
< 4 ? FUSE_COMPAT_STATFS_SIZE
: sizeof(outarg
);
260 req
->out
.args
[0].value
= &outarg
;
261 request_send(fc
, req
);
262 err
= req
->out
.h
.error
;
264 convert_fuse_statfs(buf
, &outarg
.st
);
265 fuse_put_request(fc
, req
);
274 OPT_DEFAULT_PERMISSIONS
,
280 static match_table_t tokens
= {
282 {OPT_ROOTMODE
, "rootmode=%o"},
283 {OPT_USER_ID
, "user_id=%u"},
284 {OPT_GROUP_ID
, "group_id=%u"},
285 {OPT_DEFAULT_PERMISSIONS
, "default_permissions"},
286 {OPT_ALLOW_OTHER
, "allow_other"},
287 {OPT_MAX_READ
, "max_read=%u"},
291 static int parse_fuse_opt(char *opt
, struct fuse_mount_data
*d
)
294 memset(d
, 0, sizeof(struct fuse_mount_data
));
297 while ((p
= strsep(&opt
, ",")) != NULL
) {
300 substring_t args
[MAX_OPT_ARGS
];
304 token
= match_token(p
, tokens
, args
);
307 if (match_int(&args
[0], &value
))
314 if (match_octal(&args
[0], &value
))
317 d
->rootmode_present
= 1;
321 if (match_int(&args
[0], &value
))
324 d
->user_id_present
= 1;
328 if (match_int(&args
[0], &value
))
331 d
->group_id_present
= 1;
334 case OPT_DEFAULT_PERMISSIONS
:
335 d
->flags
|= FUSE_DEFAULT_PERMISSIONS
;
338 case OPT_ALLOW_OTHER
:
339 d
->flags
|= FUSE_ALLOW_OTHER
;
343 if (match_int(&args
[0], &value
))
353 if (!d
->fd_present
|| !d
->rootmode_present
||
354 !d
->user_id_present
|| !d
->group_id_present
)
360 static int fuse_show_options(struct seq_file
*m
, struct vfsmount
*mnt
)
362 struct fuse_conn
*fc
= get_fuse_conn_super(mnt
->mnt_sb
);
364 seq_printf(m
, ",user_id=%u", fc
->user_id
);
365 seq_printf(m
, ",group_id=%u", fc
->group_id
);
366 if (fc
->flags
& FUSE_DEFAULT_PERMISSIONS
)
367 seq_puts(m
, ",default_permissions");
368 if (fc
->flags
& FUSE_ALLOW_OTHER
)
369 seq_puts(m
, ",allow_other");
370 if (fc
->max_read
!= ~0)
371 seq_printf(m
, ",max_read=%u", fc
->max_read
);
375 static struct fuse_conn
*new_conn(void)
377 struct fuse_conn
*fc
;
379 fc
= kzalloc(sizeof(*fc
), GFP_KERNEL
);
381 spin_lock_init(&fc
->lock
);
382 mutex_init(&fc
->inst_mutex
);
383 atomic_set(&fc
->count
, 1);
384 init_waitqueue_head(&fc
->waitq
);
385 init_waitqueue_head(&fc
->blocked_waitq
);
386 INIT_LIST_HEAD(&fc
->pending
);
387 INIT_LIST_HEAD(&fc
->processing
);
388 INIT_LIST_HEAD(&fc
->io
);
389 INIT_LIST_HEAD(&fc
->interrupts
);
390 atomic_set(&fc
->num_waiting
, 0);
391 fc
->bdi
.ra_pages
= (VM_MAX_READAHEAD
* 1024) / PAGE_CACHE_SIZE
;
392 fc
->bdi
.unplug_io_fn
= default_unplug_io_fn
;
395 get_random_bytes(&fc
->scramble_key
, sizeof(fc
->scramble_key
));
400 void fuse_conn_put(struct fuse_conn
*fc
)
402 if (atomic_dec_and_test(&fc
->count
)) {
403 mutex_destroy(&fc
->inst_mutex
);
408 struct fuse_conn
*fuse_conn_get(struct fuse_conn
*fc
)
410 atomic_inc(&fc
->count
);
414 static struct inode
*get_root_inode(struct super_block
*sb
, unsigned mode
)
416 struct fuse_attr attr
;
417 memset(&attr
, 0, sizeof(attr
));
420 attr
.ino
= FUSE_ROOT_ID
;
421 return fuse_iget(sb
, 1, 0, &attr
);
424 static struct super_operations fuse_super_operations
= {
425 .alloc_inode
= fuse_alloc_inode
,
426 .destroy_inode
= fuse_destroy_inode
,
427 .read_inode
= fuse_read_inode
,
428 .clear_inode
= fuse_clear_inode
,
429 .remount_fs
= fuse_remount_fs
,
430 .put_super
= fuse_put_super
,
431 .umount_begin
= fuse_umount_begin
,
432 .statfs
= fuse_statfs
,
433 .show_options
= fuse_show_options
,
436 static void process_init_reply(struct fuse_conn
*fc
, struct fuse_req
*req
)
438 struct fuse_init_out
*arg
= &req
->misc
.init_out
;
440 if (req
->out
.h
.error
|| arg
->major
!= FUSE_KERNEL_VERSION
)
443 unsigned long ra_pages
;
445 if (arg
->minor
>= 6) {
446 ra_pages
= arg
->max_readahead
/ PAGE_CACHE_SIZE
;
447 if (arg
->flags
& FUSE_ASYNC_READ
)
449 if (!(arg
->flags
& FUSE_POSIX_LOCKS
))
452 ra_pages
= fc
->max_read
/ PAGE_CACHE_SIZE
;
456 fc
->bdi
.ra_pages
= min(fc
->bdi
.ra_pages
, ra_pages
);
457 fc
->minor
= arg
->minor
;
458 fc
->max_write
= arg
->minor
< 5 ? 4096 : arg
->max_write
;
460 fuse_put_request(fc
, req
);
462 wake_up_all(&fc
->blocked_waitq
);
465 static void fuse_send_init(struct fuse_conn
*fc
, struct fuse_req
*req
)
467 struct fuse_init_in
*arg
= &req
->misc
.init_in
;
469 arg
->major
= FUSE_KERNEL_VERSION
;
470 arg
->minor
= FUSE_KERNEL_MINOR_VERSION
;
471 arg
->max_readahead
= fc
->bdi
.ra_pages
* PAGE_CACHE_SIZE
;
472 arg
->flags
|= FUSE_ASYNC_READ
| FUSE_POSIX_LOCKS
;
473 req
->in
.h
.opcode
= FUSE_INIT
;
475 req
->in
.args
[0].size
= sizeof(*arg
);
476 req
->in
.args
[0].value
= arg
;
477 req
->out
.numargs
= 1;
478 /* Variable length arguement used for backward compatibility
479 with interface version < 7.5. Rest of init_out is zeroed
480 by do_get_request(), so a short reply is not a problem */
482 req
->out
.args
[0].size
= sizeof(struct fuse_init_out
);
483 req
->out
.args
[0].value
= &req
->misc
.init_out
;
484 req
->end
= process_init_reply
;
485 request_send_background(fc
, req
);
488 static u64
conn_id(void)
494 static int fuse_fill_super(struct super_block
*sb
, void *data
, int silent
)
496 struct fuse_conn
*fc
;
498 struct fuse_mount_data d
;
500 struct dentry
*root_dentry
;
501 struct fuse_req
*init_req
;
504 if (sb
->s_flags
& MS_MANDLOCK
)
507 if (!parse_fuse_opt((char *) data
, &d
))
510 sb
->s_blocksize
= PAGE_CACHE_SIZE
;
511 sb
->s_blocksize_bits
= PAGE_CACHE_SHIFT
;
512 sb
->s_magic
= FUSE_SUPER_MAGIC
;
513 sb
->s_op
= &fuse_super_operations
;
514 sb
->s_maxbytes
= MAX_LFS_FILESIZE
;
520 if (file
->f_op
!= &fuse_dev_operations
)
528 fc
->user_id
= d
.user_id
;
529 fc
->group_id
= d
.group_id
;
530 fc
->max_read
= d
.max_read
;
532 /* Used by get_root_inode() */
536 root
= get_root_inode(sb
, d
.rootmode
);
540 root_dentry
= d_alloc_root(root
);
546 init_req
= fuse_request_alloc();
550 mutex_lock(&fuse_mutex
);
552 if (file
->private_data
)
556 err
= fuse_ctl_add_conn(fc
);
560 list_add_tail(&fc
->entry
, &fuse_conn_list
);
561 sb
->s_root
= root_dentry
;
563 file
->private_data
= fuse_conn_get(fc
);
564 mutex_unlock(&fuse_mutex
);
566 * atomic_dec_and_test() in fput() provides the necessary
567 * memory barrier for file->private_data to be visible on all
572 fuse_send_init(fc
, init_req
);
577 mutex_unlock(&fuse_mutex
);
578 fuse_request_free(init_req
);
587 static int fuse_get_sb(struct file_system_type
*fs_type
,
588 int flags
, const char *dev_name
,
589 void *raw_data
, struct vfsmount
*mnt
)
591 return get_sb_nodev(fs_type
, flags
, raw_data
, fuse_fill_super
, mnt
);
594 static struct file_system_type fuse_fs_type
= {
595 .owner
= THIS_MODULE
,
597 .get_sb
= fuse_get_sb
,
598 .kill_sb
= kill_anon_super
,
601 static decl_subsys(fuse
, NULL
, NULL
);
602 static decl_subsys(connections
, NULL
, NULL
);
604 static void fuse_inode_init_once(void *foo
, kmem_cache_t
*cachep
,
607 struct inode
* inode
= foo
;
609 if ((flags
& (SLAB_CTOR_VERIFY
|SLAB_CTOR_CONSTRUCTOR
)) ==
610 SLAB_CTOR_CONSTRUCTOR
)
611 inode_init_once(inode
);
614 static int __init
fuse_fs_init(void)
618 err
= register_filesystem(&fuse_fs_type
);
620 printk("fuse: failed to register filesystem\n");
622 fuse_inode_cachep
= kmem_cache_create("fuse_inode",
623 sizeof(struct fuse_inode
),
624 0, SLAB_HWCACHE_ALIGN
,
625 fuse_inode_init_once
, NULL
);
626 if (!fuse_inode_cachep
) {
627 unregister_filesystem(&fuse_fs_type
);
635 static void fuse_fs_cleanup(void)
637 unregister_filesystem(&fuse_fs_type
);
638 kmem_cache_destroy(fuse_inode_cachep
);
641 static int fuse_sysfs_init(void)
645 kset_set_kset_s(&fuse_subsys
, fs_subsys
);
646 err
= subsystem_register(&fuse_subsys
);
650 kset_set_kset_s(&connections_subsys
, fuse_subsys
);
651 err
= subsystem_register(&connections_subsys
);
653 goto out_fuse_unregister
;
658 subsystem_unregister(&fuse_subsys
);
663 static void fuse_sysfs_cleanup(void)
665 subsystem_unregister(&connections_subsys
);
666 subsystem_unregister(&fuse_subsys
);
669 static int __init
fuse_init(void)
673 printk("fuse init (API version %i.%i)\n",
674 FUSE_KERNEL_VERSION
, FUSE_KERNEL_MINOR_VERSION
);
676 INIT_LIST_HEAD(&fuse_conn_list
);
677 res
= fuse_fs_init();
681 res
= fuse_dev_init();
685 res
= fuse_sysfs_init();
687 goto err_dev_cleanup
;
689 res
= fuse_ctl_init();
691 goto err_sysfs_cleanup
;
696 fuse_sysfs_cleanup();
705 static void __exit
fuse_exit(void)
707 printk(KERN_DEBUG
"fuse exit\n");
710 fuse_sysfs_cleanup();
715 module_init(fuse_init
);
716 module_exit(fuse_exit
);