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()
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
);
94 INIT_LIST_HEAD(&fi
->write_files
);
95 INIT_LIST_HEAD(&fi
->queued_writes
);
96 INIT_LIST_HEAD(&fi
->writepages
);
97 init_waitqueue_head(&fi
->page_waitq
);
98 fi
->forget
= fuse_alloc_forget();
100 kmem_cache_free(fuse_inode_cachep
, inode
);
107 static void fuse_i_callback(struct rcu_head
*head
)
109 struct inode
*inode
= container_of(head
, struct inode
, i_rcu
);
110 INIT_LIST_HEAD(&inode
->i_dentry
);
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);
126 end_writeback(inode
);
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
)
143 void fuse_change_attributes_common(struct inode
*inode
, struct fuse_attr
*attr
,
146 struct fuse_conn
*fc
= get_fuse_conn(inode
);
147 struct fuse_inode
*fi
= get_fuse_inode(inode
);
149 fi
->attr_version
= ++fc
->attr_version
;
150 fi
->i_time
= attr_valid
;
152 inode
->i_ino
= attr
->ino
;
153 inode
->i_mode
= (inode
->i_mode
& S_IFMT
) | (attr
->mode
& 07777);
154 inode
->i_nlink
= attr
->nlink
;
155 inode
->i_uid
= attr
->uid
;
156 inode
->i_gid
= attr
->gid
;
157 inode
->i_blocks
= attr
->blocks
;
158 inode
->i_atime
.tv_sec
= attr
->atime
;
159 inode
->i_atime
.tv_nsec
= attr
->atimensec
;
160 inode
->i_mtime
.tv_sec
= attr
->mtime
;
161 inode
->i_mtime
.tv_nsec
= attr
->mtimensec
;
162 inode
->i_ctime
.tv_sec
= attr
->ctime
;
163 inode
->i_ctime
.tv_nsec
= attr
->ctimensec
;
165 if (attr
->blksize
!= 0)
166 inode
->i_blkbits
= ilog2(attr
->blksize
);
168 inode
->i_blkbits
= inode
->i_sb
->s_blocksize_bits
;
171 * Don't set the sticky bit in i_mode, unless we want the VFS
172 * to check permissions. This prevents failures due to the
173 * check in may_delete().
175 fi
->orig_i_mode
= inode
->i_mode
;
176 if (!(fc
->flags
& FUSE_DEFAULT_PERMISSIONS
))
177 inode
->i_mode
&= ~S_ISVTX
;
180 void fuse_change_attributes(struct inode
*inode
, struct fuse_attr
*attr
,
181 u64 attr_valid
, u64 attr_version
)
183 struct fuse_conn
*fc
= get_fuse_conn(inode
);
184 struct fuse_inode
*fi
= get_fuse_inode(inode
);
187 spin_lock(&fc
->lock
);
188 if (attr_version
!= 0 && fi
->attr_version
> attr_version
) {
189 spin_unlock(&fc
->lock
);
193 fuse_change_attributes_common(inode
, attr
, attr_valid
);
195 oldsize
= inode
->i_size
;
196 i_size_write(inode
, attr
->size
);
197 spin_unlock(&fc
->lock
);
199 if (S_ISREG(inode
->i_mode
) && oldsize
!= attr
->size
) {
200 truncate_pagecache(inode
, oldsize
, attr
->size
);
201 invalidate_inode_pages2(inode
->i_mapping
);
205 static void fuse_init_inode(struct inode
*inode
, struct fuse_attr
*attr
)
207 inode
->i_mode
= attr
->mode
& S_IFMT
;
208 inode
->i_size
= attr
->size
;
209 if (S_ISREG(inode
->i_mode
)) {
210 fuse_init_common(inode
);
211 fuse_init_file_inode(inode
);
212 } else if (S_ISDIR(inode
->i_mode
))
213 fuse_init_dir(inode
);
214 else if (S_ISLNK(inode
->i_mode
))
215 fuse_init_symlink(inode
);
216 else if (S_ISCHR(inode
->i_mode
) || S_ISBLK(inode
->i_mode
) ||
217 S_ISFIFO(inode
->i_mode
) || S_ISSOCK(inode
->i_mode
)) {
218 fuse_init_common(inode
);
219 init_special_inode(inode
, inode
->i_mode
,
220 new_decode_dev(attr
->rdev
));
225 int fuse_inode_eq(struct inode
*inode
, void *_nodeidp
)
227 u64 nodeid
= *(u64
*) _nodeidp
;
228 if (get_node_id(inode
) == nodeid
)
234 static int fuse_inode_set(struct inode
*inode
, void *_nodeidp
)
236 u64 nodeid
= *(u64
*) _nodeidp
;
237 get_fuse_inode(inode
)->nodeid
= nodeid
;
241 struct inode
*fuse_iget(struct super_block
*sb
, u64 nodeid
,
242 int generation
, struct fuse_attr
*attr
,
243 u64 attr_valid
, u64 attr_version
)
246 struct fuse_inode
*fi
;
247 struct fuse_conn
*fc
= get_fuse_conn_super(sb
);
250 inode
= iget5_locked(sb
, nodeid
, fuse_inode_eq
, fuse_inode_set
, &nodeid
);
254 if ((inode
->i_state
& I_NEW
)) {
255 inode
->i_flags
|= S_NOATIME
|S_NOCMTIME
;
256 inode
->i_generation
= generation
;
257 inode
->i_data
.backing_dev_info
= &fc
->bdi
;
258 fuse_init_inode(inode
, attr
);
259 unlock_new_inode(inode
);
260 } else if ((inode
->i_mode
^ attr
->mode
) & S_IFMT
) {
261 /* Inode has changed type, any I/O on the old should fail */
262 make_bad_inode(inode
);
267 fi
= get_fuse_inode(inode
);
268 spin_lock(&fc
->lock
);
270 spin_unlock(&fc
->lock
);
271 fuse_change_attributes(inode
, attr
, attr_valid
, attr_version
);
276 int fuse_reverse_inval_inode(struct super_block
*sb
, u64 nodeid
,
277 loff_t offset
, loff_t len
)
283 inode
= ilookup5(sb
, nodeid
, fuse_inode_eq
, &nodeid
);
287 fuse_invalidate_attr(inode
);
289 pg_start
= offset
>> PAGE_CACHE_SHIFT
;
293 pg_end
= (offset
+ len
- 1) >> PAGE_CACHE_SHIFT
;
294 invalidate_inode_pages2_range(inode
->i_mapping
,
301 static void fuse_umount_begin(struct super_block
*sb
)
303 fuse_abort_conn(get_fuse_conn_super(sb
));
306 static void fuse_send_destroy(struct fuse_conn
*fc
)
308 struct fuse_req
*req
= fc
->destroy_req
;
309 if (req
&& fc
->conn_init
) {
310 fc
->destroy_req
= NULL
;
311 req
->in
.h
.opcode
= FUSE_DESTROY
;
313 fuse_request_send(fc
, req
);
314 fuse_put_request(fc
, req
);
318 static void fuse_bdi_destroy(struct fuse_conn
*fc
)
320 if (fc
->bdi_initialized
)
321 bdi_destroy(&fc
->bdi
);
324 void fuse_conn_kill(struct fuse_conn
*fc
)
326 spin_lock(&fc
->lock
);
329 spin_unlock(&fc
->lock
);
330 /* Flush all readers on this fs */
331 kill_fasync(&fc
->fasync
, SIGIO
, POLL_IN
);
332 wake_up_all(&fc
->waitq
);
333 wake_up_all(&fc
->blocked_waitq
);
334 wake_up_all(&fc
->reserved_req_waitq
);
335 mutex_lock(&fuse_mutex
);
336 list_del(&fc
->entry
);
337 fuse_ctl_remove_conn(fc
);
338 mutex_unlock(&fuse_mutex
);
339 fuse_bdi_destroy(fc
);
341 EXPORT_SYMBOL_GPL(fuse_conn_kill
);
343 static void fuse_put_super(struct super_block
*sb
)
345 struct fuse_conn
*fc
= get_fuse_conn_super(sb
);
347 fuse_send_destroy(fc
);
352 static void convert_fuse_statfs(struct kstatfs
*stbuf
, struct fuse_kstatfs
*attr
)
354 stbuf
->f_type
= FUSE_SUPER_MAGIC
;
355 stbuf
->f_bsize
= attr
->bsize
;
356 stbuf
->f_frsize
= attr
->frsize
;
357 stbuf
->f_blocks
= attr
->blocks
;
358 stbuf
->f_bfree
= attr
->bfree
;
359 stbuf
->f_bavail
= attr
->bavail
;
360 stbuf
->f_files
= attr
->files
;
361 stbuf
->f_ffree
= attr
->ffree
;
362 stbuf
->f_namelen
= attr
->namelen
;
363 /* fsid is left zero */
366 static int fuse_statfs(struct dentry
*dentry
, struct kstatfs
*buf
)
368 struct super_block
*sb
= dentry
->d_sb
;
369 struct fuse_conn
*fc
= get_fuse_conn_super(sb
);
370 struct fuse_req
*req
;
371 struct fuse_statfs_out outarg
;
374 if (!fuse_allow_task(fc
, current
)) {
375 buf
->f_type
= FUSE_SUPER_MAGIC
;
379 req
= fuse_get_req(fc
);
383 memset(&outarg
, 0, sizeof(outarg
));
385 req
->in
.h
.opcode
= FUSE_STATFS
;
386 req
->in
.h
.nodeid
= get_node_id(dentry
->d_inode
);
387 req
->out
.numargs
= 1;
388 req
->out
.args
[0].size
=
389 fc
->minor
< 4 ? FUSE_COMPAT_STATFS_SIZE
: sizeof(outarg
);
390 req
->out
.args
[0].value
= &outarg
;
391 fuse_request_send(fc
, req
);
392 err
= req
->out
.h
.error
;
394 convert_fuse_statfs(buf
, &outarg
.st
);
395 fuse_put_request(fc
, req
);
404 OPT_DEFAULT_PERMISSIONS
,
411 static const match_table_t tokens
= {
413 {OPT_ROOTMODE
, "rootmode=%o"},
414 {OPT_USER_ID
, "user_id=%u"},
415 {OPT_GROUP_ID
, "group_id=%u"},
416 {OPT_DEFAULT_PERMISSIONS
, "default_permissions"},
417 {OPT_ALLOW_OTHER
, "allow_other"},
418 {OPT_MAX_READ
, "max_read=%u"},
419 {OPT_BLKSIZE
, "blksize=%u"},
423 static int parse_fuse_opt(char *opt
, struct fuse_mount_data
*d
, int is_bdev
)
426 memset(d
, 0, sizeof(struct fuse_mount_data
));
428 d
->blksize
= FUSE_DEFAULT_BLKSIZE
;
430 while ((p
= strsep(&opt
, ",")) != NULL
) {
433 substring_t args
[MAX_OPT_ARGS
];
437 token
= match_token(p
, tokens
, args
);
440 if (match_int(&args
[0], &value
))
447 if (match_octal(&args
[0], &value
))
449 if (!fuse_valid_type(value
))
452 d
->rootmode_present
= 1;
456 if (match_int(&args
[0], &value
))
459 d
->user_id_present
= 1;
463 if (match_int(&args
[0], &value
))
466 d
->group_id_present
= 1;
469 case OPT_DEFAULT_PERMISSIONS
:
470 d
->flags
|= FUSE_DEFAULT_PERMISSIONS
;
473 case OPT_ALLOW_OTHER
:
474 d
->flags
|= FUSE_ALLOW_OTHER
;
478 if (match_int(&args
[0], &value
))
484 if (!is_bdev
|| match_int(&args
[0], &value
))
494 if (!d
->fd_present
|| !d
->rootmode_present
||
495 !d
->user_id_present
|| !d
->group_id_present
)
501 static int fuse_show_options(struct seq_file
*m
, struct vfsmount
*mnt
)
503 struct fuse_conn
*fc
= get_fuse_conn_super(mnt
->mnt_sb
);
505 seq_printf(m
, ",user_id=%u", fc
->user_id
);
506 seq_printf(m
, ",group_id=%u", fc
->group_id
);
507 if (fc
->flags
& FUSE_DEFAULT_PERMISSIONS
)
508 seq_puts(m
, ",default_permissions");
509 if (fc
->flags
& FUSE_ALLOW_OTHER
)
510 seq_puts(m
, ",allow_other");
511 if (fc
->max_read
!= ~0)
512 seq_printf(m
, ",max_read=%u", fc
->max_read
);
513 if (mnt
->mnt_sb
->s_bdev
&&
514 mnt
->mnt_sb
->s_blocksize
!= FUSE_DEFAULT_BLKSIZE
)
515 seq_printf(m
, ",blksize=%lu", mnt
->mnt_sb
->s_blocksize
);
519 void fuse_conn_init(struct fuse_conn
*fc
)
521 memset(fc
, 0, sizeof(*fc
));
522 spin_lock_init(&fc
->lock
);
523 mutex_init(&fc
->inst_mutex
);
524 init_rwsem(&fc
->killsb
);
525 atomic_set(&fc
->count
, 1);
526 init_waitqueue_head(&fc
->waitq
);
527 init_waitqueue_head(&fc
->blocked_waitq
);
528 init_waitqueue_head(&fc
->reserved_req_waitq
);
529 INIT_LIST_HEAD(&fc
->pending
);
530 INIT_LIST_HEAD(&fc
->processing
);
531 INIT_LIST_HEAD(&fc
->io
);
532 INIT_LIST_HEAD(&fc
->interrupts
);
533 INIT_LIST_HEAD(&fc
->bg_queue
);
534 INIT_LIST_HEAD(&fc
->entry
);
535 fc
->forget_list_tail
= &fc
->forget_list_head
;
536 atomic_set(&fc
->num_waiting
, 0);
537 fc
->max_background
= FUSE_DEFAULT_MAX_BACKGROUND
;
538 fc
->congestion_threshold
= FUSE_DEFAULT_CONGESTION_THRESHOLD
;
540 fc
->polled_files
= RB_ROOT
;
543 fc
->attr_version
= 1;
544 get_random_bytes(&fc
->scramble_key
, sizeof(fc
->scramble_key
));
546 EXPORT_SYMBOL_GPL(fuse_conn_init
);
548 void fuse_conn_put(struct fuse_conn
*fc
)
550 if (atomic_dec_and_test(&fc
->count
)) {
552 fuse_request_free(fc
->destroy_req
);
553 mutex_destroy(&fc
->inst_mutex
);
557 EXPORT_SYMBOL_GPL(fuse_conn_put
);
559 struct fuse_conn
*fuse_conn_get(struct fuse_conn
*fc
)
561 atomic_inc(&fc
->count
);
564 EXPORT_SYMBOL_GPL(fuse_conn_get
);
566 static struct inode
*fuse_get_root_inode(struct super_block
*sb
, unsigned mode
)
568 struct fuse_attr attr
;
569 memset(&attr
, 0, sizeof(attr
));
572 attr
.ino
= FUSE_ROOT_ID
;
574 return fuse_iget(sb
, 1, 0, &attr
, 0, 0);
577 struct fuse_inode_handle
{
582 static struct dentry
*fuse_get_dentry(struct super_block
*sb
,
583 struct fuse_inode_handle
*handle
)
585 struct fuse_conn
*fc
= get_fuse_conn_super(sb
);
587 struct dentry
*entry
;
590 if (handle
->nodeid
== 0)
593 inode
= ilookup5(sb
, handle
->nodeid
, fuse_inode_eq
, &handle
->nodeid
);
595 struct fuse_entry_out outarg
;
598 if (!fc
->export_support
)
603 err
= fuse_lookup_name(sb
, handle
->nodeid
, &name
, &outarg
,
605 if (err
&& err
!= -ENOENT
)
612 if (get_node_id(inode
) != handle
->nodeid
)
616 if (inode
->i_generation
!= handle
->generation
)
619 entry
= d_obtain_alias(inode
);
620 if (!IS_ERR(entry
) && get_node_id(inode
) != FUSE_ROOT_ID
)
621 fuse_invalidate_entry_cache(entry
);
631 static int fuse_encode_fh(struct dentry
*dentry
, u32
*fh
, int *max_len
,
634 struct inode
*inode
= dentry
->d_inode
;
635 bool encode_parent
= connectable
&& !S_ISDIR(inode
->i_mode
);
636 int len
= encode_parent
? 6 : 3;
640 if (*max_len
< len
) {
645 nodeid
= get_fuse_inode(inode
)->nodeid
;
646 generation
= inode
->i_generation
;
648 fh
[0] = (u32
)(nodeid
>> 32);
649 fh
[1] = (u32
)(nodeid
& 0xffffffff);
653 struct inode
*parent
;
655 spin_lock(&dentry
->d_lock
);
656 parent
= dentry
->d_parent
->d_inode
;
657 nodeid
= get_fuse_inode(parent
)->nodeid
;
658 generation
= parent
->i_generation
;
659 spin_unlock(&dentry
->d_lock
);
661 fh
[3] = (u32
)(nodeid
>> 32);
662 fh
[4] = (u32
)(nodeid
& 0xffffffff);
667 return encode_parent
? 0x82 : 0x81;
670 static struct dentry
*fuse_fh_to_dentry(struct super_block
*sb
,
671 struct fid
*fid
, int fh_len
, int fh_type
)
673 struct fuse_inode_handle handle
;
675 if ((fh_type
!= 0x81 && fh_type
!= 0x82) || fh_len
< 3)
678 handle
.nodeid
= (u64
) fid
->raw
[0] << 32;
679 handle
.nodeid
|= (u64
) fid
->raw
[1];
680 handle
.generation
= fid
->raw
[2];
681 return fuse_get_dentry(sb
, &handle
);
684 static struct dentry
*fuse_fh_to_parent(struct super_block
*sb
,
685 struct fid
*fid
, int fh_len
, int fh_type
)
687 struct fuse_inode_handle parent
;
689 if (fh_type
!= 0x82 || fh_len
< 6)
692 parent
.nodeid
= (u64
) fid
->raw
[3] << 32;
693 parent
.nodeid
|= (u64
) fid
->raw
[4];
694 parent
.generation
= fid
->raw
[5];
695 return fuse_get_dentry(sb
, &parent
);
698 static struct dentry
*fuse_get_parent(struct dentry
*child
)
700 struct inode
*child_inode
= child
->d_inode
;
701 struct fuse_conn
*fc
= get_fuse_conn(child_inode
);
703 struct dentry
*parent
;
704 struct fuse_entry_out outarg
;
708 if (!fc
->export_support
)
709 return ERR_PTR(-ESTALE
);
713 err
= fuse_lookup_name(child_inode
->i_sb
, get_node_id(child_inode
),
714 &name
, &outarg
, &inode
);
717 return ERR_PTR(-ESTALE
);
721 parent
= d_obtain_alias(inode
);
722 if (!IS_ERR(parent
) && get_node_id(inode
) != FUSE_ROOT_ID
)
723 fuse_invalidate_entry_cache(parent
);
728 static const struct export_operations fuse_export_operations
= {
729 .fh_to_dentry
= fuse_fh_to_dentry
,
730 .fh_to_parent
= fuse_fh_to_parent
,
731 .encode_fh
= fuse_encode_fh
,
732 .get_parent
= fuse_get_parent
,
735 static const struct super_operations fuse_super_operations
= {
736 .alloc_inode
= fuse_alloc_inode
,
737 .destroy_inode
= fuse_destroy_inode
,
738 .evict_inode
= fuse_evict_inode
,
739 .drop_inode
= generic_delete_inode
,
740 .remount_fs
= fuse_remount_fs
,
741 .put_super
= fuse_put_super
,
742 .umount_begin
= fuse_umount_begin
,
743 .statfs
= fuse_statfs
,
744 .show_options
= fuse_show_options
,
747 static void sanitize_global_limit(unsigned *limit
)
750 *limit
= ((num_physpages
<< PAGE_SHIFT
) >> 13) /
751 sizeof(struct fuse_req
);
753 if (*limit
>= 1 << 16)
754 *limit
= (1 << 16) - 1;
757 static int set_global_limit(const char *val
, struct kernel_param
*kp
)
761 rv
= param_set_uint(val
, kp
);
765 sanitize_global_limit((unsigned *)kp
->arg
);
770 static void process_init_limits(struct fuse_conn
*fc
, struct fuse_init_out
*arg
)
772 int cap_sys_admin
= capable(CAP_SYS_ADMIN
);
777 sanitize_global_limit(&max_user_bgreq
);
778 sanitize_global_limit(&max_user_congthresh
);
780 if (arg
->max_background
) {
781 fc
->max_background
= arg
->max_background
;
783 if (!cap_sys_admin
&& fc
->max_background
> max_user_bgreq
)
784 fc
->max_background
= max_user_bgreq
;
786 if (arg
->congestion_threshold
) {
787 fc
->congestion_threshold
= arg
->congestion_threshold
;
789 if (!cap_sys_admin
&&
790 fc
->congestion_threshold
> max_user_congthresh
)
791 fc
->congestion_threshold
= max_user_congthresh
;
795 static void process_init_reply(struct fuse_conn
*fc
, struct fuse_req
*req
)
797 struct fuse_init_out
*arg
= &req
->misc
.init_out
;
799 if (req
->out
.h
.error
|| arg
->major
!= FUSE_KERNEL_VERSION
)
802 unsigned long ra_pages
;
804 process_init_limits(fc
, arg
);
806 if (arg
->minor
>= 6) {
807 ra_pages
= arg
->max_readahead
/ PAGE_CACHE_SIZE
;
808 if (arg
->flags
& FUSE_ASYNC_READ
)
810 if (!(arg
->flags
& FUSE_POSIX_LOCKS
))
812 if (arg
->flags
& FUSE_ATOMIC_O_TRUNC
)
813 fc
->atomic_o_trunc
= 1;
814 if (arg
->minor
>= 9) {
815 /* LOOKUP has dependency on proto version */
816 if (arg
->flags
& FUSE_EXPORT_SUPPORT
)
817 fc
->export_support
= 1;
819 if (arg
->flags
& FUSE_BIG_WRITES
)
821 if (arg
->flags
& FUSE_DONT_MASK
)
824 ra_pages
= fc
->max_read
/ PAGE_CACHE_SIZE
;
828 fc
->bdi
.ra_pages
= min(fc
->bdi
.ra_pages
, ra_pages
);
829 fc
->minor
= arg
->minor
;
830 fc
->max_write
= arg
->minor
< 5 ? 4096 : arg
->max_write
;
831 fc
->max_write
= max_t(unsigned, 4096, fc
->max_write
);
835 wake_up_all(&fc
->blocked_waitq
);
838 static void fuse_send_init(struct fuse_conn
*fc
, struct fuse_req
*req
)
840 struct fuse_init_in
*arg
= &req
->misc
.init_in
;
842 arg
->major
= FUSE_KERNEL_VERSION
;
843 arg
->minor
= FUSE_KERNEL_MINOR_VERSION
;
844 arg
->max_readahead
= fc
->bdi
.ra_pages
* PAGE_CACHE_SIZE
;
845 arg
->flags
|= FUSE_ASYNC_READ
| FUSE_POSIX_LOCKS
| FUSE_ATOMIC_O_TRUNC
|
846 FUSE_EXPORT_SUPPORT
| FUSE_BIG_WRITES
| FUSE_DONT_MASK
;
847 req
->in
.h
.opcode
= FUSE_INIT
;
849 req
->in
.args
[0].size
= sizeof(*arg
);
850 req
->in
.args
[0].value
= arg
;
851 req
->out
.numargs
= 1;
852 /* Variable length argument used for backward compatibility
853 with interface version < 7.5. Rest of init_out is zeroed
854 by do_get_request(), so a short reply is not a problem */
856 req
->out
.args
[0].size
= sizeof(struct fuse_init_out
);
857 req
->out
.args
[0].value
= &req
->misc
.init_out
;
858 req
->end
= process_init_reply
;
859 fuse_request_send_background(fc
, req
);
862 static void fuse_free_conn(struct fuse_conn
*fc
)
867 static int fuse_bdi_init(struct fuse_conn
*fc
, struct super_block
*sb
)
871 fc
->bdi
.name
= "fuse";
872 fc
->bdi
.ra_pages
= (VM_MAX_READAHEAD
* 1024) / PAGE_CACHE_SIZE
;
873 /* fuse does it's own writeback accounting */
874 fc
->bdi
.capabilities
= BDI_CAP_NO_ACCT_WB
;
876 err
= bdi_init(&fc
->bdi
);
880 fc
->bdi_initialized
= 1;
883 err
= bdi_register(&fc
->bdi
, NULL
, "%u:%u-fuseblk",
884 MAJOR(fc
->dev
), MINOR(fc
->dev
));
886 err
= bdi_register_dev(&fc
->bdi
, fc
->dev
);
893 * For a single fuse filesystem use max 1% of dirty +
894 * writeback threshold.
896 * This gives about 1M of write buffer for memory maps on a
897 * machine with 1G and 10% dirty_ratio, which should be more
900 * Privileged users can raise it by writing to
902 * /sys/class/bdi/<bdi>/max_ratio
904 bdi_set_max_ratio(&fc
->bdi
, 1);
909 static int fuse_fill_super(struct super_block
*sb
, void *data
, int silent
)
911 struct fuse_conn
*fc
;
913 struct fuse_mount_data d
;
915 struct dentry
*root_dentry
;
916 struct fuse_req
*init_req
;
918 int is_bdev
= sb
->s_bdev
!= NULL
;
921 if (sb
->s_flags
& MS_MANDLOCK
)
924 if (!parse_fuse_opt((char *) data
, &d
, is_bdev
))
930 if (!sb_set_blocksize(sb
, d
.blksize
))
934 sb
->s_blocksize
= PAGE_CACHE_SIZE
;
935 sb
->s_blocksize_bits
= PAGE_CACHE_SHIFT
;
937 sb
->s_magic
= FUSE_SUPER_MAGIC
;
938 sb
->s_op
= &fuse_super_operations
;
939 sb
->s_maxbytes
= MAX_LFS_FILESIZE
;
940 sb
->s_export_op
= &fuse_export_operations
;
947 if (file
->f_op
!= &fuse_dev_operations
)
950 fc
= kmalloc(sizeof(*fc
), GFP_KERNEL
);
959 err
= fuse_bdi_init(fc
, sb
);
963 sb
->s_bdi
= &fc
->bdi
;
965 /* Handle umasking inside the fuse code */
966 if (sb
->s_flags
& MS_POSIXACL
)
968 sb
->s_flags
|= MS_POSIXACL
;
970 fc
->release
= fuse_free_conn
;
972 fc
->user_id
= d
.user_id
;
973 fc
->group_id
= d
.group_id
;
974 fc
->max_read
= max_t(unsigned, 4096, d
.max_read
);
976 /* Used by get_root_inode() */
980 root
= fuse_get_root_inode(sb
, d
.rootmode
);
984 root_dentry
= d_alloc_root(root
);
989 /* only now - we want root dentry with NULL ->d_op */
990 sb
->s_d_op
= &fuse_dentry_operations
;
992 init_req
= fuse_request_alloc();
997 fc
->destroy_req
= fuse_request_alloc();
998 if (!fc
->destroy_req
)
999 goto err_free_init_req
;
1002 mutex_lock(&fuse_mutex
);
1004 if (file
->private_data
)
1007 err
= fuse_ctl_add_conn(fc
);
1011 list_add_tail(&fc
->entry
, &fuse_conn_list
);
1012 sb
->s_root
= root_dentry
;
1014 file
->private_data
= fuse_conn_get(fc
);
1015 mutex_unlock(&fuse_mutex
);
1017 * atomic_dec_and_test() in fput() provides the necessary
1018 * memory barrier for file->private_data to be visible on all
1023 fuse_send_init(fc
, init_req
);
1028 mutex_unlock(&fuse_mutex
);
1030 fuse_request_free(init_req
);
1034 fuse_bdi_destroy(fc
);
1042 static struct dentry
*fuse_mount(struct file_system_type
*fs_type
,
1043 int flags
, const char *dev_name
,
1046 return mount_nodev(fs_type
, flags
, raw_data
, fuse_fill_super
);
1049 static void fuse_kill_sb_anon(struct super_block
*sb
)
1051 struct fuse_conn
*fc
= get_fuse_conn_super(sb
);
1054 down_write(&fc
->killsb
);
1056 up_write(&fc
->killsb
);
1059 kill_anon_super(sb
);
1062 static struct file_system_type fuse_fs_type
= {
1063 .owner
= THIS_MODULE
,
1065 .fs_flags
= FS_HAS_SUBTYPE
,
1066 .mount
= fuse_mount
,
1067 .kill_sb
= fuse_kill_sb_anon
,
1071 static struct dentry
*fuse_mount_blk(struct file_system_type
*fs_type
,
1072 int flags
, const char *dev_name
,
1075 return mount_bdev(fs_type
, flags
, dev_name
, raw_data
, fuse_fill_super
);
1078 static void fuse_kill_sb_blk(struct super_block
*sb
)
1080 struct fuse_conn
*fc
= get_fuse_conn_super(sb
);
1083 down_write(&fc
->killsb
);
1085 up_write(&fc
->killsb
);
1088 kill_block_super(sb
);
1091 static struct file_system_type fuseblk_fs_type
= {
1092 .owner
= THIS_MODULE
,
1094 .mount
= fuse_mount_blk
,
1095 .kill_sb
= fuse_kill_sb_blk
,
1096 .fs_flags
= FS_REQUIRES_DEV
| FS_HAS_SUBTYPE
,
1099 static inline int register_fuseblk(void)
1101 return register_filesystem(&fuseblk_fs_type
);
1104 static inline void unregister_fuseblk(void)
1106 unregister_filesystem(&fuseblk_fs_type
);
1109 static inline int register_fuseblk(void)
1114 static inline void unregister_fuseblk(void)
1119 static void fuse_inode_init_once(void *foo
)
1121 struct inode
*inode
= foo
;
1123 inode_init_once(inode
);
1126 static int __init
fuse_fs_init(void)
1130 err
= register_filesystem(&fuse_fs_type
);
1134 err
= register_fuseblk();
1138 fuse_inode_cachep
= kmem_cache_create("fuse_inode",
1139 sizeof(struct fuse_inode
),
1140 0, SLAB_HWCACHE_ALIGN
,
1141 fuse_inode_init_once
);
1143 if (!fuse_inode_cachep
)
1149 unregister_fuseblk();
1151 unregister_filesystem(&fuse_fs_type
);
1156 static void fuse_fs_cleanup(void)
1158 unregister_filesystem(&fuse_fs_type
);
1159 unregister_fuseblk();
1160 kmem_cache_destroy(fuse_inode_cachep
);
1163 static struct kobject
*fuse_kobj
;
1164 static struct kobject
*connections_kobj
;
1166 static int fuse_sysfs_init(void)
1170 fuse_kobj
= kobject_create_and_add("fuse", fs_kobj
);
1176 connections_kobj
= kobject_create_and_add("connections", fuse_kobj
);
1177 if (!connections_kobj
) {
1179 goto out_fuse_unregister
;
1184 out_fuse_unregister
:
1185 kobject_put(fuse_kobj
);
1190 static void fuse_sysfs_cleanup(void)
1192 kobject_put(connections_kobj
);
1193 kobject_put(fuse_kobj
);
1196 static int __init
fuse_init(void)
1200 printk(KERN_INFO
"fuse init (API version %i.%i)\n",
1201 FUSE_KERNEL_VERSION
, FUSE_KERNEL_MINOR_VERSION
);
1203 INIT_LIST_HEAD(&fuse_conn_list
);
1204 res
= fuse_fs_init();
1208 res
= fuse_dev_init();
1210 goto err_fs_cleanup
;
1212 res
= fuse_sysfs_init();
1214 goto err_dev_cleanup
;
1216 res
= fuse_ctl_init();
1218 goto err_sysfs_cleanup
;
1220 sanitize_global_limit(&max_user_bgreq
);
1221 sanitize_global_limit(&max_user_congthresh
);
1226 fuse_sysfs_cleanup();
1235 static void __exit
fuse_exit(void)
1237 printk(KERN_DEBUG
"fuse exit\n");
1240 fuse_sysfs_cleanup();
1245 module_init(fuse_init
);
1246 module_exit(fuse_exit
);