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 req
= fuse_get_req(fc
);
294 memset(&outarg
, 0, sizeof(outarg
));
296 req
->in
.h
.opcode
= FUSE_STATFS
;
297 req
->in
.h
.nodeid
= get_node_id(dentry
->d_inode
);
298 req
->out
.numargs
= 1;
299 req
->out
.args
[0].size
=
300 fc
->minor
< 4 ? FUSE_COMPAT_STATFS_SIZE
: sizeof(outarg
);
301 req
->out
.args
[0].value
= &outarg
;
302 request_send(fc
, req
);
303 err
= req
->out
.h
.error
;
305 convert_fuse_statfs(buf
, &outarg
.st
);
306 fuse_put_request(fc
, req
);
315 OPT_DEFAULT_PERMISSIONS
,
322 static match_table_t tokens
= {
324 {OPT_ROOTMODE
, "rootmode=%o"},
325 {OPT_USER_ID
, "user_id=%u"},
326 {OPT_GROUP_ID
, "group_id=%u"},
327 {OPT_DEFAULT_PERMISSIONS
, "default_permissions"},
328 {OPT_ALLOW_OTHER
, "allow_other"},
329 {OPT_MAX_READ
, "max_read=%u"},
330 {OPT_BLKSIZE
, "blksize=%u"},
334 static int parse_fuse_opt(char *opt
, struct fuse_mount_data
*d
, int is_bdev
)
337 memset(d
, 0, sizeof(struct fuse_mount_data
));
341 while ((p
= strsep(&opt
, ",")) != NULL
) {
344 substring_t args
[MAX_OPT_ARGS
];
348 token
= match_token(p
, tokens
, args
);
351 if (match_int(&args
[0], &value
))
358 if (match_octal(&args
[0], &value
))
360 if (!fuse_valid_type(value
))
363 d
->rootmode_present
= 1;
367 if (match_int(&args
[0], &value
))
370 d
->user_id_present
= 1;
374 if (match_int(&args
[0], &value
))
377 d
->group_id_present
= 1;
380 case OPT_DEFAULT_PERMISSIONS
:
381 d
->flags
|= FUSE_DEFAULT_PERMISSIONS
;
384 case OPT_ALLOW_OTHER
:
385 d
->flags
|= FUSE_ALLOW_OTHER
;
389 if (match_int(&args
[0], &value
))
395 if (!is_bdev
|| match_int(&args
[0], &value
))
405 if (!d
->fd_present
|| !d
->rootmode_present
||
406 !d
->user_id_present
|| !d
->group_id_present
)
412 static int fuse_show_options(struct seq_file
*m
, struct vfsmount
*mnt
)
414 struct fuse_conn
*fc
= get_fuse_conn_super(mnt
->mnt_sb
);
416 seq_printf(m
, ",user_id=%u", fc
->user_id
);
417 seq_printf(m
, ",group_id=%u", fc
->group_id
);
418 if (fc
->flags
& FUSE_DEFAULT_PERMISSIONS
)
419 seq_puts(m
, ",default_permissions");
420 if (fc
->flags
& FUSE_ALLOW_OTHER
)
421 seq_puts(m
, ",allow_other");
422 if (fc
->max_read
!= ~0)
423 seq_printf(m
, ",max_read=%u", fc
->max_read
);
427 static struct fuse_conn
*new_conn(void)
429 struct fuse_conn
*fc
;
432 fc
= kzalloc(sizeof(*fc
), GFP_KERNEL
);
434 spin_lock_init(&fc
->lock
);
435 mutex_init(&fc
->inst_mutex
);
436 atomic_set(&fc
->count
, 1);
437 init_waitqueue_head(&fc
->waitq
);
438 init_waitqueue_head(&fc
->blocked_waitq
);
439 init_waitqueue_head(&fc
->reserved_req_waitq
);
440 INIT_LIST_HEAD(&fc
->pending
);
441 INIT_LIST_HEAD(&fc
->processing
);
442 INIT_LIST_HEAD(&fc
->io
);
443 INIT_LIST_HEAD(&fc
->interrupts
);
444 atomic_set(&fc
->num_waiting
, 0);
445 fc
->bdi
.ra_pages
= (VM_MAX_READAHEAD
* 1024) / PAGE_CACHE_SIZE
;
446 fc
->bdi
.unplug_io_fn
= default_unplug_io_fn
;
447 err
= bdi_init(&fc
->bdi
);
455 get_random_bytes(&fc
->scramble_key
, sizeof(fc
->scramble_key
));
461 void fuse_conn_put(struct fuse_conn
*fc
)
463 if (atomic_dec_and_test(&fc
->count
)) {
465 fuse_request_free(fc
->destroy_req
);
466 mutex_destroy(&fc
->inst_mutex
);
467 bdi_destroy(&fc
->bdi
);
472 struct fuse_conn
*fuse_conn_get(struct fuse_conn
*fc
)
474 atomic_inc(&fc
->count
);
478 static struct inode
*get_root_inode(struct super_block
*sb
, unsigned mode
)
480 struct fuse_attr attr
;
481 memset(&attr
, 0, sizeof(attr
));
484 attr
.ino
= FUSE_ROOT_ID
;
486 return fuse_iget(sb
, 1, 0, &attr
);
489 static const struct super_operations fuse_super_operations
= {
490 .alloc_inode
= fuse_alloc_inode
,
491 .destroy_inode
= fuse_destroy_inode
,
492 .read_inode
= fuse_read_inode
,
493 .clear_inode
= fuse_clear_inode
,
494 .drop_inode
= generic_delete_inode
,
495 .remount_fs
= fuse_remount_fs
,
496 .put_super
= fuse_put_super
,
497 .umount_begin
= fuse_umount_begin
,
498 .statfs
= fuse_statfs
,
499 .show_options
= fuse_show_options
,
502 static void process_init_reply(struct fuse_conn
*fc
, struct fuse_req
*req
)
504 struct fuse_init_out
*arg
= &req
->misc
.init_out
;
506 if (req
->out
.h
.error
|| arg
->major
!= FUSE_KERNEL_VERSION
)
509 unsigned long ra_pages
;
511 if (arg
->minor
>= 6) {
512 ra_pages
= arg
->max_readahead
/ PAGE_CACHE_SIZE
;
513 if (arg
->flags
& FUSE_ASYNC_READ
)
515 if (!(arg
->flags
& FUSE_POSIX_LOCKS
))
518 ra_pages
= fc
->max_read
/ PAGE_CACHE_SIZE
;
522 fc
->bdi
.ra_pages
= min(fc
->bdi
.ra_pages
, ra_pages
);
523 fc
->minor
= arg
->minor
;
524 fc
->max_write
= arg
->minor
< 5 ? 4096 : arg
->max_write
;
527 fuse_put_request(fc
, req
);
529 wake_up_all(&fc
->blocked_waitq
);
532 static void fuse_send_init(struct fuse_conn
*fc
, struct fuse_req
*req
)
534 struct fuse_init_in
*arg
= &req
->misc
.init_in
;
536 arg
->major
= FUSE_KERNEL_VERSION
;
537 arg
->minor
= FUSE_KERNEL_MINOR_VERSION
;
538 arg
->max_readahead
= fc
->bdi
.ra_pages
* PAGE_CACHE_SIZE
;
539 arg
->flags
|= FUSE_ASYNC_READ
| FUSE_POSIX_LOCKS
;
540 req
->in
.h
.opcode
= FUSE_INIT
;
542 req
->in
.args
[0].size
= sizeof(*arg
);
543 req
->in
.args
[0].value
= arg
;
544 req
->out
.numargs
= 1;
545 /* Variable length arguement used for backward compatibility
546 with interface version < 7.5. Rest of init_out is zeroed
547 by do_get_request(), so a short reply is not a problem */
549 req
->out
.args
[0].size
= sizeof(struct fuse_init_out
);
550 req
->out
.args
[0].value
= &req
->misc
.init_out
;
551 req
->end
= process_init_reply
;
552 request_send_background(fc
, req
);
555 static u64
conn_id(void)
561 static int fuse_fill_super(struct super_block
*sb
, void *data
, int silent
)
563 struct fuse_conn
*fc
;
565 struct fuse_mount_data d
;
567 struct dentry
*root_dentry
;
568 struct fuse_req
*init_req
;
570 int is_bdev
= sb
->s_bdev
!= NULL
;
572 if (sb
->s_flags
& MS_MANDLOCK
)
575 if (!parse_fuse_opt((char *) data
, &d
, is_bdev
))
580 if (!sb_set_blocksize(sb
, d
.blksize
))
584 sb
->s_blocksize
= PAGE_CACHE_SIZE
;
585 sb
->s_blocksize_bits
= PAGE_CACHE_SHIFT
;
587 sb
->s_magic
= FUSE_SUPER_MAGIC
;
588 sb
->s_op
= &fuse_super_operations
;
589 sb
->s_maxbytes
= MAX_LFS_FILESIZE
;
595 if (file
->f_op
!= &fuse_dev_operations
)
603 fc
->user_id
= d
.user_id
;
604 fc
->group_id
= d
.group_id
;
605 fc
->max_read
= d
.max_read
;
607 /* Used by get_root_inode() */
611 root
= get_root_inode(sb
, d
.rootmode
);
615 root_dentry
= d_alloc_root(root
);
621 init_req
= fuse_request_alloc();
626 fc
->destroy_req
= fuse_request_alloc();
627 if (!fc
->destroy_req
)
631 mutex_lock(&fuse_mutex
);
633 if (file
->private_data
)
637 err
= fuse_ctl_add_conn(fc
);
641 list_add_tail(&fc
->entry
, &fuse_conn_list
);
642 sb
->s_root
= root_dentry
;
644 file
->private_data
= fuse_conn_get(fc
);
645 mutex_unlock(&fuse_mutex
);
647 * atomic_dec_and_test() in fput() provides the necessary
648 * memory barrier for file->private_data to be visible on all
653 fuse_send_init(fc
, init_req
);
658 mutex_unlock(&fuse_mutex
);
659 fuse_request_free(init_req
);
668 static int fuse_get_sb(struct file_system_type
*fs_type
,
669 int flags
, const char *dev_name
,
670 void *raw_data
, struct vfsmount
*mnt
)
672 return get_sb_nodev(fs_type
, flags
, raw_data
, fuse_fill_super
, mnt
);
675 static struct file_system_type fuse_fs_type
= {
676 .owner
= THIS_MODULE
,
678 .fs_flags
= FS_HAS_SUBTYPE
,
679 .get_sb
= fuse_get_sb
,
680 .kill_sb
= kill_anon_super
,
684 static int fuse_get_sb_blk(struct file_system_type
*fs_type
,
685 int flags
, const char *dev_name
,
686 void *raw_data
, struct vfsmount
*mnt
)
688 return get_sb_bdev(fs_type
, flags
, dev_name
, raw_data
, fuse_fill_super
,
692 static struct file_system_type fuseblk_fs_type
= {
693 .owner
= THIS_MODULE
,
695 .get_sb
= fuse_get_sb_blk
,
696 .kill_sb
= kill_block_super
,
697 .fs_flags
= FS_REQUIRES_DEV
| FS_HAS_SUBTYPE
,
700 static inline int register_fuseblk(void)
702 return register_filesystem(&fuseblk_fs_type
);
705 static inline void unregister_fuseblk(void)
707 unregister_filesystem(&fuseblk_fs_type
);
710 static inline int register_fuseblk(void)
715 static inline void unregister_fuseblk(void)
720 static decl_subsys(fuse
, NULL
, NULL
);
721 static decl_subsys(connections
, NULL
, NULL
);
723 static void fuse_inode_init_once(struct kmem_cache
*cachep
, void *foo
)
725 struct inode
* inode
= foo
;
727 inode_init_once(inode
);
730 static int __init
fuse_fs_init(void)
734 err
= register_filesystem(&fuse_fs_type
);
738 err
= register_fuseblk();
742 fuse_inode_cachep
= kmem_cache_create("fuse_inode",
743 sizeof(struct fuse_inode
),
744 0, SLAB_HWCACHE_ALIGN
,
745 fuse_inode_init_once
);
747 if (!fuse_inode_cachep
)
753 unregister_fuseblk();
755 unregister_filesystem(&fuse_fs_type
);
760 static void fuse_fs_cleanup(void)
762 unregister_filesystem(&fuse_fs_type
);
763 unregister_fuseblk();
764 kmem_cache_destroy(fuse_inode_cachep
);
767 static int fuse_sysfs_init(void)
771 kobj_set_kset_s(&fuse_subsys
, fs_subsys
);
772 err
= subsystem_register(&fuse_subsys
);
776 kobj_set_kset_s(&connections_subsys
, fuse_subsys
);
777 err
= subsystem_register(&connections_subsys
);
779 goto out_fuse_unregister
;
784 subsystem_unregister(&fuse_subsys
);
789 static void fuse_sysfs_cleanup(void)
791 subsystem_unregister(&connections_subsys
);
792 subsystem_unregister(&fuse_subsys
);
795 static int __init
fuse_init(void)
799 printk("fuse init (API version %i.%i)\n",
800 FUSE_KERNEL_VERSION
, FUSE_KERNEL_MINOR_VERSION
);
802 INIT_LIST_HEAD(&fuse_conn_list
);
803 res
= fuse_fs_init();
807 res
= fuse_dev_init();
811 res
= fuse_sysfs_init();
813 goto err_dev_cleanup
;
815 res
= fuse_ctl_init();
817 goto err_sysfs_cleanup
;
822 fuse_sysfs_cleanup();
831 static void __exit
fuse_exit(void)
833 printk(KERN_DEBUG
"fuse exit\n");
836 fuse_sysfs_cleanup();
841 module_init(fuse_init
);
842 module_exit(fuse_exit
);