2 FUSE: Filesystem in Userspace
3 Copyright (C) 2001-2008 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/moduleparam.h>
18 #include <linux/parser.h>
19 #include <linux/statfs.h>
20 #include <linux/random.h>
21 #include <linux/sched.h>
22 #include <linux/exportfs.h>
24 MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>");
25 MODULE_DESCRIPTION("Filesystem in Userspace");
26 MODULE_LICENSE("GPL");
28 static struct kmem_cache
*fuse_inode_cachep
;
29 struct list_head fuse_conn_list
;
30 DEFINE_MUTEX(fuse_mutex
);
32 static int set_global_limit(const char *val
, struct kernel_param
*kp
);
34 unsigned max_user_bgreq
;
35 module_param_call(max_user_bgreq
, set_global_limit
, param_get_uint
,
36 &max_user_bgreq
, 0644);
37 __MODULE_PARM_TYPE(max_user_bgreq
, "uint");
38 MODULE_PARM_DESC(max_user_bgreq
,
39 "Global limit for the maximum number of backgrounded requests an "
40 "unprivileged user can set");
42 unsigned max_user_congthresh
;
43 module_param_call(max_user_congthresh
, set_global_limit
, param_get_uint
,
44 &max_user_congthresh
, 0644);
45 __MODULE_PARM_TYPE(max_user_congthresh
, "uint");
46 MODULE_PARM_DESC(max_user_congthresh
,
47 "Global limit for the maximum congestion threshold an "
48 "unprivileged user can set");
50 #define FUSE_SUPER_MAGIC 0x65735546
52 #define FUSE_DEFAULT_BLKSIZE 512
54 /** Maximum number of outstanding background requests */
55 #define FUSE_DEFAULT_MAX_BACKGROUND 12
57 /** Congestion starts at 75% of maximum */
58 #define FUSE_DEFAULT_CONGESTION_THRESHOLD (FUSE_DEFAULT_MAX_BACKGROUND * 3 / 4)
60 struct fuse_mount_data
{
65 unsigned fd_present
:1;
66 unsigned rootmode_present
:1;
67 unsigned user_id_present
:1;
68 unsigned group_id_present
:1;
74 struct fuse_forget_link
*fuse_alloc_forget(void)
76 return kzalloc(sizeof(struct fuse_forget_link
), GFP_KERNEL
);
79 static struct inode
*fuse_alloc_inode(struct super_block
*sb
)
82 struct fuse_inode
*fi
;
84 inode
= kmem_cache_alloc(fuse_inode_cachep
, GFP_KERNEL
);
88 fi
= get_fuse_inode(inode
);
95 INIT_LIST_HEAD(&fi
->write_files
);
96 INIT_LIST_HEAD(&fi
->queued_writes
);
97 INIT_LIST_HEAD(&fi
->writepages
);
98 init_waitqueue_head(&fi
->page_waitq
);
99 fi
->forget
= fuse_alloc_forget();
101 kmem_cache_free(fuse_inode_cachep
, inode
);
108 static void fuse_i_callback(struct rcu_head
*head
)
110 struct inode
*inode
= container_of(head
, struct inode
, i_rcu
);
111 kmem_cache_free(fuse_inode_cachep
, inode
);
114 static void fuse_destroy_inode(struct inode
*inode
)
116 struct fuse_inode
*fi
= get_fuse_inode(inode
);
117 BUG_ON(!list_empty(&fi
->write_files
));
118 BUG_ON(!list_empty(&fi
->queued_writes
));
120 call_rcu(&inode
->i_rcu
, fuse_i_callback
);
123 static void fuse_evict_inode(struct inode
*inode
)
125 truncate_inode_pages(&inode
->i_data
, 0);
127 if (inode
->i_sb
->s_flags
& MS_ACTIVE
) {
128 struct fuse_conn
*fc
= get_fuse_conn(inode
);
129 struct fuse_inode
*fi
= get_fuse_inode(inode
);
130 fuse_queue_forget(fc
, fi
->forget
, fi
->nodeid
, fi
->nlookup
);
135 static int fuse_remount_fs(struct super_block
*sb
, int *flags
, char *data
)
137 if (*flags
& MS_MANDLOCK
)
144 * ino_t is 32-bits on 32-bit arch. We have to squash the 64-bit value down
145 * so that it will fit.
147 static ino_t
fuse_squash_ino(u64 ino64
)
149 ino_t ino
= (ino_t
) ino64
;
150 if (sizeof(ino_t
) < sizeof(u64
))
151 ino
^= ino64
>> (sizeof(u64
) - sizeof(ino_t
)) * 8;
155 void fuse_change_attributes_common(struct inode
*inode
, struct fuse_attr
*attr
,
158 struct fuse_conn
*fc
= get_fuse_conn(inode
);
159 struct fuse_inode
*fi
= get_fuse_inode(inode
);
161 fi
->attr_version
= ++fc
->attr_version
;
162 fi
->i_time
= attr_valid
;
164 inode
->i_ino
= fuse_squash_ino(attr
->ino
);
165 inode
->i_mode
= (inode
->i_mode
& S_IFMT
) | (attr
->mode
& 07777);
166 set_nlink(inode
, attr
->nlink
);
167 inode
->i_uid
= attr
->uid
;
168 inode
->i_gid
= attr
->gid
;
169 inode
->i_blocks
= attr
->blocks
;
170 inode
->i_atime
.tv_sec
= attr
->atime
;
171 inode
->i_atime
.tv_nsec
= attr
->atimensec
;
172 inode
->i_mtime
.tv_sec
= attr
->mtime
;
173 inode
->i_mtime
.tv_nsec
= attr
->mtimensec
;
174 inode
->i_ctime
.tv_sec
= attr
->ctime
;
175 inode
->i_ctime
.tv_nsec
= attr
->ctimensec
;
177 if (attr
->blksize
!= 0)
178 inode
->i_blkbits
= ilog2(attr
->blksize
);
180 inode
->i_blkbits
= inode
->i_sb
->s_blocksize_bits
;
183 * Don't set the sticky bit in i_mode, unless we want the VFS
184 * to check permissions. This prevents failures due to the
185 * check in may_delete().
187 fi
->orig_i_mode
= inode
->i_mode
;
188 if (!(fc
->flags
& FUSE_DEFAULT_PERMISSIONS
))
189 inode
->i_mode
&= ~S_ISVTX
;
191 fi
->orig_ino
= attr
->ino
;
194 void fuse_change_attributes(struct inode
*inode
, struct fuse_attr
*attr
,
195 u64 attr_valid
, u64 attr_version
)
197 struct fuse_conn
*fc
= get_fuse_conn(inode
);
198 struct fuse_inode
*fi
= get_fuse_inode(inode
);
201 spin_lock(&fc
->lock
);
202 if (attr_version
!= 0 && fi
->attr_version
> attr_version
) {
203 spin_unlock(&fc
->lock
);
207 fuse_change_attributes_common(inode
, attr
, attr_valid
);
209 oldsize
= inode
->i_size
;
210 i_size_write(inode
, attr
->size
);
211 spin_unlock(&fc
->lock
);
213 if (S_ISREG(inode
->i_mode
) && oldsize
!= attr
->size
) {
214 truncate_pagecache(inode
, oldsize
, attr
->size
);
215 invalidate_inode_pages2(inode
->i_mapping
);
219 static void fuse_init_inode(struct inode
*inode
, struct fuse_attr
*attr
)
221 inode
->i_mode
= attr
->mode
& S_IFMT
;
222 inode
->i_size
= attr
->size
;
223 if (S_ISREG(inode
->i_mode
)) {
224 fuse_init_common(inode
);
225 fuse_init_file_inode(inode
);
226 } else if (S_ISDIR(inode
->i_mode
))
227 fuse_init_dir(inode
);
228 else if (S_ISLNK(inode
->i_mode
))
229 fuse_init_symlink(inode
);
230 else if (S_ISCHR(inode
->i_mode
) || S_ISBLK(inode
->i_mode
) ||
231 S_ISFIFO(inode
->i_mode
) || S_ISSOCK(inode
->i_mode
)) {
232 fuse_init_common(inode
);
233 init_special_inode(inode
, inode
->i_mode
,
234 new_decode_dev(attr
->rdev
));
239 int fuse_inode_eq(struct inode
*inode
, void *_nodeidp
)
241 u64 nodeid
= *(u64
*) _nodeidp
;
242 if (get_node_id(inode
) == nodeid
)
248 static int fuse_inode_set(struct inode
*inode
, void *_nodeidp
)
250 u64 nodeid
= *(u64
*) _nodeidp
;
251 get_fuse_inode(inode
)->nodeid
= nodeid
;
255 struct inode
*fuse_iget(struct super_block
*sb
, u64 nodeid
,
256 int generation
, struct fuse_attr
*attr
,
257 u64 attr_valid
, u64 attr_version
)
260 struct fuse_inode
*fi
;
261 struct fuse_conn
*fc
= get_fuse_conn_super(sb
);
264 inode
= iget5_locked(sb
, nodeid
, fuse_inode_eq
, fuse_inode_set
, &nodeid
);
268 if ((inode
->i_state
& I_NEW
)) {
269 inode
->i_flags
|= S_NOATIME
|S_NOCMTIME
;
270 inode
->i_generation
= generation
;
271 inode
->i_data
.backing_dev_info
= &fc
->bdi
;
272 fuse_init_inode(inode
, attr
);
273 unlock_new_inode(inode
);
274 } else if ((inode
->i_mode
^ attr
->mode
) & S_IFMT
) {
275 /* Inode has changed type, any I/O on the old should fail */
276 make_bad_inode(inode
);
281 fi
= get_fuse_inode(inode
);
282 spin_lock(&fc
->lock
);
284 spin_unlock(&fc
->lock
);
285 fuse_change_attributes(inode
, attr
, attr_valid
, attr_version
);
290 int fuse_reverse_inval_inode(struct super_block
*sb
, u64 nodeid
,
291 loff_t offset
, loff_t len
)
297 inode
= ilookup5(sb
, nodeid
, fuse_inode_eq
, &nodeid
);
301 fuse_invalidate_attr(inode
);
303 pg_start
= offset
>> PAGE_CACHE_SHIFT
;
307 pg_end
= (offset
+ len
- 1) >> PAGE_CACHE_SHIFT
;
308 invalidate_inode_pages2_range(inode
->i_mapping
,
315 static void fuse_umount_begin(struct super_block
*sb
)
317 fuse_abort_conn(get_fuse_conn_super(sb
));
320 static void fuse_send_destroy(struct fuse_conn
*fc
)
322 struct fuse_req
*req
= fc
->destroy_req
;
323 if (req
&& fc
->conn_init
) {
324 fc
->destroy_req
= NULL
;
325 req
->in
.h
.opcode
= FUSE_DESTROY
;
327 fuse_request_send(fc
, req
);
328 fuse_put_request(fc
, req
);
332 static void fuse_bdi_destroy(struct fuse_conn
*fc
)
334 if (fc
->bdi_initialized
)
335 bdi_destroy(&fc
->bdi
);
338 void fuse_conn_kill(struct fuse_conn
*fc
)
340 spin_lock(&fc
->lock
);
343 spin_unlock(&fc
->lock
);
344 /* Flush all readers on this fs */
345 kill_fasync(&fc
->fasync
, SIGIO
, POLL_IN
);
346 wake_up_all(&fc
->waitq
);
347 wake_up_all(&fc
->blocked_waitq
);
348 wake_up_all(&fc
->reserved_req_waitq
);
349 mutex_lock(&fuse_mutex
);
350 list_del(&fc
->entry
);
351 fuse_ctl_remove_conn(fc
);
352 mutex_unlock(&fuse_mutex
);
353 fuse_bdi_destroy(fc
);
355 EXPORT_SYMBOL_GPL(fuse_conn_kill
);
357 static void fuse_put_super(struct super_block
*sb
)
359 struct fuse_conn
*fc
= get_fuse_conn_super(sb
);
361 fuse_send_destroy(fc
);
366 static void convert_fuse_statfs(struct kstatfs
*stbuf
, struct fuse_kstatfs
*attr
)
368 stbuf
->f_type
= FUSE_SUPER_MAGIC
;
369 stbuf
->f_bsize
= attr
->bsize
;
370 stbuf
->f_frsize
= attr
->frsize
;
371 stbuf
->f_blocks
= attr
->blocks
;
372 stbuf
->f_bfree
= attr
->bfree
;
373 stbuf
->f_bavail
= attr
->bavail
;
374 stbuf
->f_files
= attr
->files
;
375 stbuf
->f_ffree
= attr
->ffree
;
376 stbuf
->f_namelen
= attr
->namelen
;
377 /* fsid is left zero */
380 static int fuse_statfs(struct dentry
*dentry
, struct kstatfs
*buf
)
382 struct super_block
*sb
= dentry
->d_sb
;
383 struct fuse_conn
*fc
= get_fuse_conn_super(sb
);
384 struct fuse_req
*req
;
385 struct fuse_statfs_out outarg
;
388 if (!fuse_allow_task(fc
, current
)) {
389 buf
->f_type
= FUSE_SUPER_MAGIC
;
393 req
= fuse_get_req(fc
);
397 memset(&outarg
, 0, sizeof(outarg
));
399 req
->in
.h
.opcode
= FUSE_STATFS
;
400 req
->in
.h
.nodeid
= get_node_id(dentry
->d_inode
);
401 req
->out
.numargs
= 1;
402 req
->out
.args
[0].size
=
403 fc
->minor
< 4 ? FUSE_COMPAT_STATFS_SIZE
: sizeof(outarg
);
404 req
->out
.args
[0].value
= &outarg
;
405 fuse_request_send(fc
, req
);
406 err
= req
->out
.h
.error
;
408 convert_fuse_statfs(buf
, &outarg
.st
);
409 fuse_put_request(fc
, req
);
418 OPT_DEFAULT_PERMISSIONS
,
425 static const match_table_t tokens
= {
427 {OPT_ROOTMODE
, "rootmode=%o"},
428 {OPT_USER_ID
, "user_id=%u"},
429 {OPT_GROUP_ID
, "group_id=%u"},
430 {OPT_DEFAULT_PERMISSIONS
, "default_permissions"},
431 {OPT_ALLOW_OTHER
, "allow_other"},
432 {OPT_MAX_READ
, "max_read=%u"},
433 {OPT_BLKSIZE
, "blksize=%u"},
437 static int parse_fuse_opt(char *opt
, struct fuse_mount_data
*d
, int is_bdev
)
440 memset(d
, 0, sizeof(struct fuse_mount_data
));
442 d
->blksize
= FUSE_DEFAULT_BLKSIZE
;
444 while ((p
= strsep(&opt
, ",")) != NULL
) {
447 substring_t args
[MAX_OPT_ARGS
];
451 token
= match_token(p
, tokens
, args
);
454 if (match_int(&args
[0], &value
))
461 if (match_octal(&args
[0], &value
))
463 if (!fuse_valid_type(value
))
466 d
->rootmode_present
= 1;
470 if (match_int(&args
[0], &value
))
473 d
->user_id_present
= 1;
477 if (match_int(&args
[0], &value
))
480 d
->group_id_present
= 1;
483 case OPT_DEFAULT_PERMISSIONS
:
484 d
->flags
|= FUSE_DEFAULT_PERMISSIONS
;
487 case OPT_ALLOW_OTHER
:
488 d
->flags
|= FUSE_ALLOW_OTHER
;
492 if (match_int(&args
[0], &value
))
498 if (!is_bdev
|| match_int(&args
[0], &value
))
508 if (!d
->fd_present
|| !d
->rootmode_present
||
509 !d
->user_id_present
|| !d
->group_id_present
)
515 static int fuse_show_options(struct seq_file
*m
, struct dentry
*root
)
517 struct super_block
*sb
= root
->d_sb
;
518 struct fuse_conn
*fc
= get_fuse_conn_super(sb
);
520 seq_printf(m
, ",user_id=%u", fc
->user_id
);
521 seq_printf(m
, ",group_id=%u", fc
->group_id
);
522 if (fc
->flags
& FUSE_DEFAULT_PERMISSIONS
)
523 seq_puts(m
, ",default_permissions");
524 if (fc
->flags
& FUSE_ALLOW_OTHER
)
525 seq_puts(m
, ",allow_other");
526 if (fc
->max_read
!= ~0)
527 seq_printf(m
, ",max_read=%u", fc
->max_read
);
528 if (sb
->s_bdev
&& sb
->s_blocksize
!= FUSE_DEFAULT_BLKSIZE
)
529 seq_printf(m
, ",blksize=%lu", sb
->s_blocksize
);
533 void fuse_conn_init(struct fuse_conn
*fc
)
535 memset(fc
, 0, sizeof(*fc
));
536 spin_lock_init(&fc
->lock
);
537 mutex_init(&fc
->inst_mutex
);
538 init_rwsem(&fc
->killsb
);
539 atomic_set(&fc
->count
, 1);
540 init_waitqueue_head(&fc
->waitq
);
541 init_waitqueue_head(&fc
->blocked_waitq
);
542 init_waitqueue_head(&fc
->reserved_req_waitq
);
543 INIT_LIST_HEAD(&fc
->pending
);
544 INIT_LIST_HEAD(&fc
->processing
);
545 INIT_LIST_HEAD(&fc
->io
);
546 INIT_LIST_HEAD(&fc
->interrupts
);
547 INIT_LIST_HEAD(&fc
->bg_queue
);
548 INIT_LIST_HEAD(&fc
->entry
);
549 fc
->forget_list_tail
= &fc
->forget_list_head
;
550 atomic_set(&fc
->num_waiting
, 0);
551 fc
->max_background
= FUSE_DEFAULT_MAX_BACKGROUND
;
552 fc
->congestion_threshold
= FUSE_DEFAULT_CONGESTION_THRESHOLD
;
554 fc
->polled_files
= RB_ROOT
;
557 fc
->attr_version
= 1;
558 get_random_bytes(&fc
->scramble_key
, sizeof(fc
->scramble_key
));
560 EXPORT_SYMBOL_GPL(fuse_conn_init
);
562 void fuse_conn_put(struct fuse_conn
*fc
)
564 if (atomic_dec_and_test(&fc
->count
)) {
566 fuse_request_free(fc
->destroy_req
);
567 mutex_destroy(&fc
->inst_mutex
);
571 EXPORT_SYMBOL_GPL(fuse_conn_put
);
573 struct fuse_conn
*fuse_conn_get(struct fuse_conn
*fc
)
575 atomic_inc(&fc
->count
);
578 EXPORT_SYMBOL_GPL(fuse_conn_get
);
580 static struct inode
*fuse_get_root_inode(struct super_block
*sb
, unsigned mode
)
582 struct fuse_attr attr
;
583 memset(&attr
, 0, sizeof(attr
));
586 attr
.ino
= FUSE_ROOT_ID
;
588 return fuse_iget(sb
, 1, 0, &attr
, 0, 0);
591 struct fuse_inode_handle
{
596 static struct dentry
*fuse_get_dentry(struct super_block
*sb
,
597 struct fuse_inode_handle
*handle
)
599 struct fuse_conn
*fc
= get_fuse_conn_super(sb
);
601 struct dentry
*entry
;
604 if (handle
->nodeid
== 0)
607 inode
= ilookup5(sb
, handle
->nodeid
, fuse_inode_eq
, &handle
->nodeid
);
609 struct fuse_entry_out outarg
;
612 if (!fc
->export_support
)
617 err
= fuse_lookup_name(sb
, handle
->nodeid
, &name
, &outarg
,
619 if (err
&& err
!= -ENOENT
)
626 if (get_node_id(inode
) != handle
->nodeid
)
630 if (inode
->i_generation
!= handle
->generation
)
633 entry
= d_obtain_alias(inode
);
634 if (!IS_ERR(entry
) && get_node_id(inode
) != FUSE_ROOT_ID
)
635 fuse_invalidate_entry_cache(entry
);
645 static int fuse_encode_fh(struct inode
*inode
, u32
*fh
, int *max_len
,
646 struct inode
*parent
)
648 int len
= parent
? 6 : 3;
652 if (*max_len
< len
) {
657 nodeid
= get_fuse_inode(inode
)->nodeid
;
658 generation
= inode
->i_generation
;
660 fh
[0] = (u32
)(nodeid
>> 32);
661 fh
[1] = (u32
)(nodeid
& 0xffffffff);
665 nodeid
= get_fuse_inode(parent
)->nodeid
;
666 generation
= parent
->i_generation
;
668 fh
[3] = (u32
)(nodeid
>> 32);
669 fh
[4] = (u32
)(nodeid
& 0xffffffff);
674 return parent
? 0x82 : 0x81;
677 static struct dentry
*fuse_fh_to_dentry(struct super_block
*sb
,
678 struct fid
*fid
, int fh_len
, int fh_type
)
680 struct fuse_inode_handle handle
;
682 if ((fh_type
!= 0x81 && fh_type
!= 0x82) || fh_len
< 3)
685 handle
.nodeid
= (u64
) fid
->raw
[0] << 32;
686 handle
.nodeid
|= (u64
) fid
->raw
[1];
687 handle
.generation
= fid
->raw
[2];
688 return fuse_get_dentry(sb
, &handle
);
691 static struct dentry
*fuse_fh_to_parent(struct super_block
*sb
,
692 struct fid
*fid
, int fh_len
, int fh_type
)
694 struct fuse_inode_handle parent
;
696 if (fh_type
!= 0x82 || fh_len
< 6)
699 parent
.nodeid
= (u64
) fid
->raw
[3] << 32;
700 parent
.nodeid
|= (u64
) fid
->raw
[4];
701 parent
.generation
= fid
->raw
[5];
702 return fuse_get_dentry(sb
, &parent
);
705 static struct dentry
*fuse_get_parent(struct dentry
*child
)
707 struct inode
*child_inode
= child
->d_inode
;
708 struct fuse_conn
*fc
= get_fuse_conn(child_inode
);
710 struct dentry
*parent
;
711 struct fuse_entry_out outarg
;
715 if (!fc
->export_support
)
716 return ERR_PTR(-ESTALE
);
720 err
= fuse_lookup_name(child_inode
->i_sb
, get_node_id(child_inode
),
721 &name
, &outarg
, &inode
);
724 return ERR_PTR(-ESTALE
);
728 parent
= d_obtain_alias(inode
);
729 if (!IS_ERR(parent
) && get_node_id(inode
) != FUSE_ROOT_ID
)
730 fuse_invalidate_entry_cache(parent
);
735 static const struct export_operations fuse_export_operations
= {
736 .fh_to_dentry
= fuse_fh_to_dentry
,
737 .fh_to_parent
= fuse_fh_to_parent
,
738 .encode_fh
= fuse_encode_fh
,
739 .get_parent
= fuse_get_parent
,
742 static const struct super_operations fuse_super_operations
= {
743 .alloc_inode
= fuse_alloc_inode
,
744 .destroy_inode
= fuse_destroy_inode
,
745 .evict_inode
= fuse_evict_inode
,
746 .drop_inode
= generic_delete_inode
,
747 .remount_fs
= fuse_remount_fs
,
748 .put_super
= fuse_put_super
,
749 .umount_begin
= fuse_umount_begin
,
750 .statfs
= fuse_statfs
,
751 .show_options
= fuse_show_options
,
754 static void sanitize_global_limit(unsigned *limit
)
757 *limit
= ((num_physpages
<< PAGE_SHIFT
) >> 13) /
758 sizeof(struct fuse_req
);
760 if (*limit
>= 1 << 16)
761 *limit
= (1 << 16) - 1;
764 static int set_global_limit(const char *val
, struct kernel_param
*kp
)
768 rv
= param_set_uint(val
, kp
);
772 sanitize_global_limit((unsigned *)kp
->arg
);
777 static void process_init_limits(struct fuse_conn
*fc
, struct fuse_init_out
*arg
)
779 int cap_sys_admin
= capable(CAP_SYS_ADMIN
);
784 sanitize_global_limit(&max_user_bgreq
);
785 sanitize_global_limit(&max_user_congthresh
);
787 if (arg
->max_background
) {
788 fc
->max_background
= arg
->max_background
;
790 if (!cap_sys_admin
&& fc
->max_background
> max_user_bgreq
)
791 fc
->max_background
= max_user_bgreq
;
793 if (arg
->congestion_threshold
) {
794 fc
->congestion_threshold
= arg
->congestion_threshold
;
796 if (!cap_sys_admin
&&
797 fc
->congestion_threshold
> max_user_congthresh
)
798 fc
->congestion_threshold
= max_user_congthresh
;
802 static void process_init_reply(struct fuse_conn
*fc
, struct fuse_req
*req
)
804 struct fuse_init_out
*arg
= &req
->misc
.init_out
;
806 if (req
->out
.h
.error
|| arg
->major
!= FUSE_KERNEL_VERSION
)
809 unsigned long ra_pages
;
811 process_init_limits(fc
, arg
);
813 if (arg
->minor
>= 6) {
814 ra_pages
= arg
->max_readahead
/ PAGE_CACHE_SIZE
;
815 if (arg
->flags
& FUSE_ASYNC_READ
)
817 if (!(arg
->flags
& FUSE_POSIX_LOCKS
))
819 if (arg
->minor
>= 17) {
820 if (!(arg
->flags
& FUSE_FLOCK_LOCKS
))
823 if (!(arg
->flags
& FUSE_POSIX_LOCKS
))
826 if (arg
->flags
& FUSE_ATOMIC_O_TRUNC
)
827 fc
->atomic_o_trunc
= 1;
828 if (arg
->minor
>= 9) {
829 /* LOOKUP has dependency on proto version */
830 if (arg
->flags
& FUSE_EXPORT_SUPPORT
)
831 fc
->export_support
= 1;
833 if (arg
->flags
& FUSE_BIG_WRITES
)
835 if (arg
->flags
& FUSE_DONT_MASK
)
838 ra_pages
= fc
->max_read
/ PAGE_CACHE_SIZE
;
843 fc
->bdi
.ra_pages
= min(fc
->bdi
.ra_pages
, ra_pages
);
844 fc
->minor
= arg
->minor
;
845 fc
->max_write
= arg
->minor
< 5 ? 4096 : arg
->max_write
;
846 fc
->max_write
= max_t(unsigned, 4096, fc
->max_write
);
850 wake_up_all(&fc
->blocked_waitq
);
853 static void fuse_send_init(struct fuse_conn
*fc
, struct fuse_req
*req
)
855 struct fuse_init_in
*arg
= &req
->misc
.init_in
;
857 arg
->major
= FUSE_KERNEL_VERSION
;
858 arg
->minor
= FUSE_KERNEL_MINOR_VERSION
;
859 arg
->max_readahead
= fc
->bdi
.ra_pages
* PAGE_CACHE_SIZE
;
860 arg
->flags
|= FUSE_ASYNC_READ
| FUSE_POSIX_LOCKS
| FUSE_ATOMIC_O_TRUNC
|
861 FUSE_EXPORT_SUPPORT
| FUSE_BIG_WRITES
| FUSE_DONT_MASK
|
863 req
->in
.h
.opcode
= FUSE_INIT
;
865 req
->in
.args
[0].size
= sizeof(*arg
);
866 req
->in
.args
[0].value
= arg
;
867 req
->out
.numargs
= 1;
868 /* Variable length argument used for backward compatibility
869 with interface version < 7.5. Rest of init_out is zeroed
870 by do_get_request(), so a short reply is not a problem */
872 req
->out
.args
[0].size
= sizeof(struct fuse_init_out
);
873 req
->out
.args
[0].value
= &req
->misc
.init_out
;
874 req
->end
= process_init_reply
;
875 fuse_request_send_background(fc
, req
);
878 static void fuse_free_conn(struct fuse_conn
*fc
)
883 static int fuse_bdi_init(struct fuse_conn
*fc
, struct super_block
*sb
)
887 fc
->bdi
.name
= "fuse";
888 fc
->bdi
.ra_pages
= (VM_MAX_READAHEAD
* 1024) / PAGE_CACHE_SIZE
;
889 /* fuse does it's own writeback accounting */
890 fc
->bdi
.capabilities
= BDI_CAP_NO_ACCT_WB
;
892 err
= bdi_init(&fc
->bdi
);
896 fc
->bdi_initialized
= 1;
899 err
= bdi_register(&fc
->bdi
, NULL
, "%u:%u-fuseblk",
900 MAJOR(fc
->dev
), MINOR(fc
->dev
));
902 err
= bdi_register_dev(&fc
->bdi
, fc
->dev
);
909 * For a single fuse filesystem use max 1% of dirty +
910 * writeback threshold.
912 * This gives about 1M of write buffer for memory maps on a
913 * machine with 1G and 10% dirty_ratio, which should be more
916 * Privileged users can raise it by writing to
918 * /sys/class/bdi/<bdi>/max_ratio
920 bdi_set_max_ratio(&fc
->bdi
, 1);
925 static int fuse_fill_super(struct super_block
*sb
, void *data
, int silent
)
927 struct fuse_conn
*fc
;
929 struct fuse_mount_data d
;
931 struct dentry
*root_dentry
;
932 struct fuse_req
*init_req
;
934 int is_bdev
= sb
->s_bdev
!= NULL
;
937 if (sb
->s_flags
& MS_MANDLOCK
)
940 sb
->s_flags
&= ~MS_NOSEC
;
942 if (!parse_fuse_opt((char *) data
, &d
, is_bdev
))
948 if (!sb_set_blocksize(sb
, d
.blksize
))
952 sb
->s_blocksize
= PAGE_CACHE_SIZE
;
953 sb
->s_blocksize_bits
= PAGE_CACHE_SHIFT
;
955 sb
->s_magic
= FUSE_SUPER_MAGIC
;
956 sb
->s_op
= &fuse_super_operations
;
957 sb
->s_maxbytes
= MAX_LFS_FILESIZE
;
959 sb
->s_export_op
= &fuse_export_operations
;
966 if (file
->f_op
!= &fuse_dev_operations
)
969 fc
= kmalloc(sizeof(*fc
), GFP_KERNEL
);
978 err
= fuse_bdi_init(fc
, sb
);
982 sb
->s_bdi
= &fc
->bdi
;
984 /* Handle umasking inside the fuse code */
985 if (sb
->s_flags
& MS_POSIXACL
)
987 sb
->s_flags
|= MS_POSIXACL
;
989 fc
->release
= fuse_free_conn
;
991 fc
->user_id
= d
.user_id
;
992 fc
->group_id
= d
.group_id
;
993 fc
->max_read
= max_t(unsigned, 4096, d
.max_read
);
995 /* Used by get_root_inode() */
999 root
= fuse_get_root_inode(sb
, d
.rootmode
);
1000 root_dentry
= d_make_root(root
);
1003 /* only now - we want root dentry with NULL ->d_op */
1004 sb
->s_d_op
= &fuse_dentry_operations
;
1006 init_req
= fuse_request_alloc();
1011 fc
->destroy_req
= fuse_request_alloc();
1012 if (!fc
->destroy_req
)
1013 goto err_free_init_req
;
1016 mutex_lock(&fuse_mutex
);
1018 if (file
->private_data
)
1021 err
= fuse_ctl_add_conn(fc
);
1025 list_add_tail(&fc
->entry
, &fuse_conn_list
);
1026 sb
->s_root
= root_dentry
;
1028 file
->private_data
= fuse_conn_get(fc
);
1029 mutex_unlock(&fuse_mutex
);
1031 * atomic_dec_and_test() in fput() provides the necessary
1032 * memory barrier for file->private_data to be visible on all
1037 fuse_send_init(fc
, init_req
);
1042 mutex_unlock(&fuse_mutex
);
1044 fuse_request_free(init_req
);
1048 fuse_bdi_destroy(fc
);
1056 static struct dentry
*fuse_mount(struct file_system_type
*fs_type
,
1057 int flags
, const char *dev_name
,
1060 return mount_nodev(fs_type
, flags
, raw_data
, fuse_fill_super
);
1063 static void fuse_kill_sb_anon(struct super_block
*sb
)
1065 struct fuse_conn
*fc
= get_fuse_conn_super(sb
);
1068 down_write(&fc
->killsb
);
1070 up_write(&fc
->killsb
);
1073 kill_anon_super(sb
);
1076 static struct file_system_type fuse_fs_type
= {
1077 .owner
= THIS_MODULE
,
1079 .fs_flags
= FS_HAS_SUBTYPE
,
1080 .mount
= fuse_mount
,
1081 .kill_sb
= fuse_kill_sb_anon
,
1085 static struct dentry
*fuse_mount_blk(struct file_system_type
*fs_type
,
1086 int flags
, const char *dev_name
,
1089 return mount_bdev(fs_type
, flags
, dev_name
, raw_data
, fuse_fill_super
);
1092 static void fuse_kill_sb_blk(struct super_block
*sb
)
1094 struct fuse_conn
*fc
= get_fuse_conn_super(sb
);
1097 down_write(&fc
->killsb
);
1099 up_write(&fc
->killsb
);
1102 kill_block_super(sb
);
1105 static struct file_system_type fuseblk_fs_type
= {
1106 .owner
= THIS_MODULE
,
1108 .mount
= fuse_mount_blk
,
1109 .kill_sb
= fuse_kill_sb_blk
,
1110 .fs_flags
= FS_REQUIRES_DEV
| FS_HAS_SUBTYPE
,
1113 static inline int register_fuseblk(void)
1115 return register_filesystem(&fuseblk_fs_type
);
1118 static inline void unregister_fuseblk(void)
1120 unregister_filesystem(&fuseblk_fs_type
);
1123 static inline int register_fuseblk(void)
1128 static inline void unregister_fuseblk(void)
1133 static void fuse_inode_init_once(void *foo
)
1135 struct inode
*inode
= foo
;
1137 inode_init_once(inode
);
1140 static int __init
fuse_fs_init(void)
1144 fuse_inode_cachep
= kmem_cache_create("fuse_inode",
1145 sizeof(struct fuse_inode
),
1146 0, SLAB_HWCACHE_ALIGN
,
1147 fuse_inode_init_once
);
1149 if (!fuse_inode_cachep
)
1152 err
= register_fuseblk();
1156 err
= register_filesystem(&fuse_fs_type
);
1163 unregister_fuseblk();
1165 kmem_cache_destroy(fuse_inode_cachep
);
1170 static void fuse_fs_cleanup(void)
1172 unregister_filesystem(&fuse_fs_type
);
1173 unregister_fuseblk();
1174 kmem_cache_destroy(fuse_inode_cachep
);
1177 static struct kobject
*fuse_kobj
;
1178 static struct kobject
*connections_kobj
;
1180 static int fuse_sysfs_init(void)
1184 fuse_kobj
= kobject_create_and_add("fuse", fs_kobj
);
1190 connections_kobj
= kobject_create_and_add("connections", fuse_kobj
);
1191 if (!connections_kobj
) {
1193 goto out_fuse_unregister
;
1198 out_fuse_unregister
:
1199 kobject_put(fuse_kobj
);
1204 static void fuse_sysfs_cleanup(void)
1206 kobject_put(connections_kobj
);
1207 kobject_put(fuse_kobj
);
1210 static int __init
fuse_init(void)
1214 printk(KERN_INFO
"fuse init (API version %i.%i)\n",
1215 FUSE_KERNEL_VERSION
, FUSE_KERNEL_MINOR_VERSION
);
1217 INIT_LIST_HEAD(&fuse_conn_list
);
1218 res
= fuse_fs_init();
1222 res
= fuse_dev_init();
1224 goto err_fs_cleanup
;
1226 res
= fuse_sysfs_init();
1228 goto err_dev_cleanup
;
1230 res
= fuse_ctl_init();
1232 goto err_sysfs_cleanup
;
1234 sanitize_global_limit(&max_user_bgreq
);
1235 sanitize_global_limit(&max_user_congthresh
);
1240 fuse_sysfs_cleanup();
1249 static void __exit
fuse_exit(void)
1251 printk(KERN_DEBUG
"fuse exit\n");
1254 fuse_sysfs_cleanup();
1259 module_init(fuse_init
);
1260 module_exit(fuse_exit
);