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 static struct inode
*fuse_alloc_inode(struct super_block
*sb
)
77 struct fuse_inode
*fi
;
79 inode
= kmem_cache_alloc(fuse_inode_cachep
, GFP_KERNEL
);
83 fi
= get_fuse_inode(inode
);
89 INIT_LIST_HEAD(&fi
->write_files
);
90 INIT_LIST_HEAD(&fi
->queued_writes
);
91 INIT_LIST_HEAD(&fi
->writepages
);
92 init_waitqueue_head(&fi
->page_waitq
);
93 fi
->forget_req
= fuse_request_alloc();
94 if (!fi
->forget_req
) {
95 kmem_cache_free(fuse_inode_cachep
, inode
);
102 static void fuse_destroy_inode(struct inode
*inode
)
104 struct fuse_inode
*fi
= get_fuse_inode(inode
);
105 BUG_ON(!list_empty(&fi
->write_files
));
106 BUG_ON(!list_empty(&fi
->queued_writes
));
108 fuse_request_free(fi
->forget_req
);
109 kmem_cache_free(fuse_inode_cachep
, inode
);
112 void fuse_send_forget(struct fuse_conn
*fc
, struct fuse_req
*req
,
113 u64 nodeid
, u64 nlookup
)
115 struct fuse_forget_in
*inarg
= &req
->misc
.forget_in
;
116 inarg
->nlookup
= nlookup
;
117 req
->in
.h
.opcode
= FUSE_FORGET
;
118 req
->in
.h
.nodeid
= nodeid
;
120 req
->in
.args
[0].size
= sizeof(struct fuse_forget_in
);
121 req
->in
.args
[0].value
= inarg
;
122 fuse_request_send_noreply(fc
, req
);
125 static void fuse_clear_inode(struct inode
*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_send_forget(fc
, fi
->forget_req
, fi
->nodeid
, fi
->nlookup
);
131 fi
->forget_req
= NULL
;
135 static int fuse_remount_fs(struct super_block
*sb
, int *flags
, char *data
)
137 if (*flags
& MS_MANDLOCK
)
143 void fuse_truncate(struct address_space
*mapping
, loff_t offset
)
145 /* See vmtruncate() */
146 unmap_mapping_range(mapping
, offset
+ PAGE_SIZE
- 1, 0, 1);
147 truncate_inode_pages(mapping
, offset
);
148 unmap_mapping_range(mapping
, offset
+ PAGE_SIZE
- 1, 0, 1);
151 void fuse_change_attributes_common(struct inode
*inode
, struct fuse_attr
*attr
,
154 struct fuse_conn
*fc
= get_fuse_conn(inode
);
155 struct fuse_inode
*fi
= get_fuse_inode(inode
);
157 fi
->attr_version
= ++fc
->attr_version
;
158 fi
->i_time
= attr_valid
;
160 inode
->i_ino
= attr
->ino
;
161 inode
->i_mode
= (inode
->i_mode
& S_IFMT
) | (attr
->mode
& 07777);
162 inode
->i_nlink
= attr
->nlink
;
163 inode
->i_uid
= attr
->uid
;
164 inode
->i_gid
= attr
->gid
;
165 inode
->i_blocks
= attr
->blocks
;
166 inode
->i_atime
.tv_sec
= attr
->atime
;
167 inode
->i_atime
.tv_nsec
= attr
->atimensec
;
168 inode
->i_mtime
.tv_sec
= attr
->mtime
;
169 inode
->i_mtime
.tv_nsec
= attr
->mtimensec
;
170 inode
->i_ctime
.tv_sec
= attr
->ctime
;
171 inode
->i_ctime
.tv_nsec
= attr
->ctimensec
;
173 if (attr
->blksize
!= 0)
174 inode
->i_blkbits
= ilog2(attr
->blksize
);
176 inode
->i_blkbits
= inode
->i_sb
->s_blocksize_bits
;
179 * Don't set the sticky bit in i_mode, unless we want the VFS
180 * to check permissions. This prevents failures due to the
181 * check in may_delete().
183 fi
->orig_i_mode
= inode
->i_mode
;
184 if (!(fc
->flags
& FUSE_DEFAULT_PERMISSIONS
))
185 inode
->i_mode
&= ~S_ISVTX
;
188 void fuse_change_attributes(struct inode
*inode
, struct fuse_attr
*attr
,
189 u64 attr_valid
, u64 attr_version
)
191 struct fuse_conn
*fc
= get_fuse_conn(inode
);
192 struct fuse_inode
*fi
= get_fuse_inode(inode
);
195 spin_lock(&fc
->lock
);
196 if (attr_version
!= 0 && fi
->attr_version
> attr_version
) {
197 spin_unlock(&fc
->lock
);
201 fuse_change_attributes_common(inode
, attr
, attr_valid
);
203 oldsize
= inode
->i_size
;
204 i_size_write(inode
, attr
->size
);
205 spin_unlock(&fc
->lock
);
207 if (S_ISREG(inode
->i_mode
) && oldsize
!= attr
->size
) {
208 if (attr
->size
< oldsize
)
209 fuse_truncate(inode
->i_mapping
, attr
->size
);
210 invalidate_inode_pages2(inode
->i_mapping
);
214 static void fuse_init_inode(struct inode
*inode
, struct fuse_attr
*attr
)
216 inode
->i_mode
= attr
->mode
& S_IFMT
;
217 inode
->i_size
= attr
->size
;
218 if (S_ISREG(inode
->i_mode
)) {
219 fuse_init_common(inode
);
220 fuse_init_file_inode(inode
);
221 } else if (S_ISDIR(inode
->i_mode
))
222 fuse_init_dir(inode
);
223 else if (S_ISLNK(inode
->i_mode
))
224 fuse_init_symlink(inode
);
225 else if (S_ISCHR(inode
->i_mode
) || S_ISBLK(inode
->i_mode
) ||
226 S_ISFIFO(inode
->i_mode
) || S_ISSOCK(inode
->i_mode
)) {
227 fuse_init_common(inode
);
228 init_special_inode(inode
, inode
->i_mode
,
229 new_decode_dev(attr
->rdev
));
234 int fuse_inode_eq(struct inode
*inode
, void *_nodeidp
)
236 u64 nodeid
= *(u64
*) _nodeidp
;
237 if (get_node_id(inode
) == nodeid
)
243 static int fuse_inode_set(struct inode
*inode
, void *_nodeidp
)
245 u64 nodeid
= *(u64
*) _nodeidp
;
246 get_fuse_inode(inode
)->nodeid
= nodeid
;
250 struct inode
*fuse_iget(struct super_block
*sb
, u64 nodeid
,
251 int generation
, struct fuse_attr
*attr
,
252 u64 attr_valid
, u64 attr_version
)
255 struct fuse_inode
*fi
;
256 struct fuse_conn
*fc
= get_fuse_conn_super(sb
);
259 inode
= iget5_locked(sb
, nodeid
, fuse_inode_eq
, fuse_inode_set
, &nodeid
);
263 if ((inode
->i_state
& I_NEW
)) {
264 inode
->i_flags
|= S_NOATIME
|S_NOCMTIME
;
265 inode
->i_generation
= generation
;
266 inode
->i_data
.backing_dev_info
= &fc
->bdi
;
267 fuse_init_inode(inode
, attr
);
268 unlock_new_inode(inode
);
269 } else if ((inode
->i_mode
^ attr
->mode
) & S_IFMT
) {
270 /* Inode has changed type, any I/O on the old should fail */
271 make_bad_inode(inode
);
276 fi
= get_fuse_inode(inode
);
277 spin_lock(&fc
->lock
);
279 spin_unlock(&fc
->lock
);
280 fuse_change_attributes(inode
, attr
, attr_valid
, attr_version
);
285 int fuse_reverse_inval_inode(struct super_block
*sb
, u64 nodeid
,
286 loff_t offset
, loff_t len
)
292 inode
= ilookup5(sb
, nodeid
, fuse_inode_eq
, &nodeid
);
296 fuse_invalidate_attr(inode
);
298 pg_start
= offset
>> PAGE_CACHE_SHIFT
;
302 pg_end
= (offset
+ len
- 1) >> PAGE_CACHE_SHIFT
;
303 invalidate_inode_pages2_range(inode
->i_mapping
,
310 static void fuse_umount_begin(struct super_block
*sb
)
312 fuse_abort_conn(get_fuse_conn_super(sb
));
315 static void fuse_send_destroy(struct fuse_conn
*fc
)
317 struct fuse_req
*req
= fc
->destroy_req
;
318 if (req
&& fc
->conn_init
) {
319 fc
->destroy_req
= NULL
;
320 req
->in
.h
.opcode
= FUSE_DESTROY
;
322 fuse_request_send(fc
, req
);
323 fuse_put_request(fc
, req
);
327 static void fuse_bdi_destroy(struct fuse_conn
*fc
)
329 if (fc
->bdi_initialized
)
330 bdi_destroy(&fc
->bdi
);
333 void fuse_conn_kill(struct fuse_conn
*fc
)
335 spin_lock(&fc
->lock
);
338 spin_unlock(&fc
->lock
);
339 /* Flush all readers on this fs */
340 kill_fasync(&fc
->fasync
, SIGIO
, POLL_IN
);
341 wake_up_all(&fc
->waitq
);
342 wake_up_all(&fc
->blocked_waitq
);
343 wake_up_all(&fc
->reserved_req_waitq
);
344 mutex_lock(&fuse_mutex
);
345 list_del(&fc
->entry
);
346 fuse_ctl_remove_conn(fc
);
347 mutex_unlock(&fuse_mutex
);
348 fuse_bdi_destroy(fc
);
350 EXPORT_SYMBOL_GPL(fuse_conn_kill
);
352 static void fuse_put_super(struct super_block
*sb
)
354 struct fuse_conn
*fc
= get_fuse_conn_super(sb
);
356 fuse_send_destroy(fc
);
361 static void convert_fuse_statfs(struct kstatfs
*stbuf
, struct fuse_kstatfs
*attr
)
363 stbuf
->f_type
= FUSE_SUPER_MAGIC
;
364 stbuf
->f_bsize
= attr
->bsize
;
365 stbuf
->f_frsize
= attr
->frsize
;
366 stbuf
->f_blocks
= attr
->blocks
;
367 stbuf
->f_bfree
= attr
->bfree
;
368 stbuf
->f_bavail
= attr
->bavail
;
369 stbuf
->f_files
= attr
->files
;
370 stbuf
->f_ffree
= attr
->ffree
;
371 stbuf
->f_namelen
= attr
->namelen
;
372 /* fsid is left zero */
375 static int fuse_statfs(struct dentry
*dentry
, struct kstatfs
*buf
)
377 struct super_block
*sb
= dentry
->d_sb
;
378 struct fuse_conn
*fc
= get_fuse_conn_super(sb
);
379 struct fuse_req
*req
;
380 struct fuse_statfs_out outarg
;
383 if (!fuse_allow_task(fc
, current
)) {
384 buf
->f_type
= FUSE_SUPER_MAGIC
;
388 req
= fuse_get_req(fc
);
392 memset(&outarg
, 0, sizeof(outarg
));
394 req
->in
.h
.opcode
= FUSE_STATFS
;
395 req
->in
.h
.nodeid
= get_node_id(dentry
->d_inode
);
396 req
->out
.numargs
= 1;
397 req
->out
.args
[0].size
=
398 fc
->minor
< 4 ? FUSE_COMPAT_STATFS_SIZE
: sizeof(outarg
);
399 req
->out
.args
[0].value
= &outarg
;
400 fuse_request_send(fc
, req
);
401 err
= req
->out
.h
.error
;
403 convert_fuse_statfs(buf
, &outarg
.st
);
404 fuse_put_request(fc
, req
);
413 OPT_DEFAULT_PERMISSIONS
,
420 static const match_table_t tokens
= {
422 {OPT_ROOTMODE
, "rootmode=%o"},
423 {OPT_USER_ID
, "user_id=%u"},
424 {OPT_GROUP_ID
, "group_id=%u"},
425 {OPT_DEFAULT_PERMISSIONS
, "default_permissions"},
426 {OPT_ALLOW_OTHER
, "allow_other"},
427 {OPT_MAX_READ
, "max_read=%u"},
428 {OPT_BLKSIZE
, "blksize=%u"},
432 static int parse_fuse_opt(char *opt
, struct fuse_mount_data
*d
, int is_bdev
)
435 memset(d
, 0, sizeof(struct fuse_mount_data
));
437 d
->blksize
= FUSE_DEFAULT_BLKSIZE
;
439 while ((p
= strsep(&opt
, ",")) != NULL
) {
442 substring_t args
[MAX_OPT_ARGS
];
446 token
= match_token(p
, tokens
, args
);
449 if (match_int(&args
[0], &value
))
456 if (match_octal(&args
[0], &value
))
458 if (!fuse_valid_type(value
))
461 d
->rootmode_present
= 1;
465 if (match_int(&args
[0], &value
))
468 d
->user_id_present
= 1;
472 if (match_int(&args
[0], &value
))
475 d
->group_id_present
= 1;
478 case OPT_DEFAULT_PERMISSIONS
:
479 d
->flags
|= FUSE_DEFAULT_PERMISSIONS
;
482 case OPT_ALLOW_OTHER
:
483 d
->flags
|= FUSE_ALLOW_OTHER
;
487 if (match_int(&args
[0], &value
))
493 if (!is_bdev
|| match_int(&args
[0], &value
))
503 if (!d
->fd_present
|| !d
->rootmode_present
||
504 !d
->user_id_present
|| !d
->group_id_present
)
510 static int fuse_show_options(struct seq_file
*m
, struct vfsmount
*mnt
)
512 struct fuse_conn
*fc
= get_fuse_conn_super(mnt
->mnt_sb
);
514 seq_printf(m
, ",user_id=%u", fc
->user_id
);
515 seq_printf(m
, ",group_id=%u", fc
->group_id
);
516 if (fc
->flags
& FUSE_DEFAULT_PERMISSIONS
)
517 seq_puts(m
, ",default_permissions");
518 if (fc
->flags
& FUSE_ALLOW_OTHER
)
519 seq_puts(m
, ",allow_other");
520 if (fc
->max_read
!= ~0)
521 seq_printf(m
, ",max_read=%u", fc
->max_read
);
522 if (mnt
->mnt_sb
->s_bdev
&&
523 mnt
->mnt_sb
->s_blocksize
!= FUSE_DEFAULT_BLKSIZE
)
524 seq_printf(m
, ",blksize=%lu", mnt
->mnt_sb
->s_blocksize
);
528 void fuse_conn_init(struct fuse_conn
*fc
)
530 memset(fc
, 0, sizeof(*fc
));
531 spin_lock_init(&fc
->lock
);
532 mutex_init(&fc
->inst_mutex
);
533 init_rwsem(&fc
->killsb
);
534 atomic_set(&fc
->count
, 1);
535 init_waitqueue_head(&fc
->waitq
);
536 init_waitqueue_head(&fc
->blocked_waitq
);
537 init_waitqueue_head(&fc
->reserved_req_waitq
);
538 INIT_LIST_HEAD(&fc
->pending
);
539 INIT_LIST_HEAD(&fc
->processing
);
540 INIT_LIST_HEAD(&fc
->io
);
541 INIT_LIST_HEAD(&fc
->interrupts
);
542 INIT_LIST_HEAD(&fc
->bg_queue
);
543 INIT_LIST_HEAD(&fc
->entry
);
544 atomic_set(&fc
->num_waiting
, 0);
545 fc
->max_background
= FUSE_DEFAULT_MAX_BACKGROUND
;
546 fc
->congestion_threshold
= FUSE_DEFAULT_CONGESTION_THRESHOLD
;
548 fc
->polled_files
= RB_ROOT
;
551 fc
->attr_version
= 1;
552 get_random_bytes(&fc
->scramble_key
, sizeof(fc
->scramble_key
));
554 EXPORT_SYMBOL_GPL(fuse_conn_init
);
556 void fuse_conn_put(struct fuse_conn
*fc
)
558 if (atomic_dec_and_test(&fc
->count
)) {
560 fuse_request_free(fc
->destroy_req
);
561 mutex_destroy(&fc
->inst_mutex
);
565 EXPORT_SYMBOL_GPL(fuse_conn_put
);
567 struct fuse_conn
*fuse_conn_get(struct fuse_conn
*fc
)
569 atomic_inc(&fc
->count
);
572 EXPORT_SYMBOL_GPL(fuse_conn_get
);
574 static struct inode
*fuse_get_root_inode(struct super_block
*sb
, unsigned mode
)
576 struct fuse_attr attr
;
577 memset(&attr
, 0, sizeof(attr
));
580 attr
.ino
= FUSE_ROOT_ID
;
582 return fuse_iget(sb
, 1, 0, &attr
, 0, 0);
585 struct fuse_inode_handle
{
590 static struct dentry
*fuse_get_dentry(struct super_block
*sb
,
591 struct fuse_inode_handle
*handle
)
593 struct fuse_conn
*fc
= get_fuse_conn_super(sb
);
595 struct dentry
*entry
;
598 if (handle
->nodeid
== 0)
601 inode
= ilookup5(sb
, handle
->nodeid
, fuse_inode_eq
, &handle
->nodeid
);
603 struct fuse_entry_out outarg
;
606 if (!fc
->export_support
)
611 err
= fuse_lookup_name(sb
, handle
->nodeid
, &name
, &outarg
,
613 if (err
&& err
!= -ENOENT
)
620 if (get_node_id(inode
) != handle
->nodeid
)
624 if (inode
->i_generation
!= handle
->generation
)
627 entry
= d_obtain_alias(inode
);
628 if (!IS_ERR(entry
) && get_node_id(inode
) != FUSE_ROOT_ID
) {
629 entry
->d_op
= &fuse_dentry_operations
;
630 fuse_invalidate_entry_cache(entry
);
641 static int fuse_encode_fh(struct dentry
*dentry
, u32
*fh
, int *max_len
,
644 struct inode
*inode
= dentry
->d_inode
;
645 bool encode_parent
= connectable
&& !S_ISDIR(inode
->i_mode
);
646 int len
= encode_parent
? 6 : 3;
653 nodeid
= get_fuse_inode(inode
)->nodeid
;
654 generation
= inode
->i_generation
;
656 fh
[0] = (u32
)(nodeid
>> 32);
657 fh
[1] = (u32
)(nodeid
& 0xffffffff);
661 struct inode
*parent
;
663 spin_lock(&dentry
->d_lock
);
664 parent
= dentry
->d_parent
->d_inode
;
665 nodeid
= get_fuse_inode(parent
)->nodeid
;
666 generation
= parent
->i_generation
;
667 spin_unlock(&dentry
->d_lock
);
669 fh
[3] = (u32
)(nodeid
>> 32);
670 fh
[4] = (u32
)(nodeid
& 0xffffffff);
675 return encode_parent
? 0x82 : 0x81;
678 static struct dentry
*fuse_fh_to_dentry(struct super_block
*sb
,
679 struct fid
*fid
, int fh_len
, int fh_type
)
681 struct fuse_inode_handle handle
;
683 if ((fh_type
!= 0x81 && fh_type
!= 0x82) || fh_len
< 3)
686 handle
.nodeid
= (u64
) fid
->raw
[0] << 32;
687 handle
.nodeid
|= (u64
) fid
->raw
[1];
688 handle
.generation
= fid
->raw
[2];
689 return fuse_get_dentry(sb
, &handle
);
692 static struct dentry
*fuse_fh_to_parent(struct super_block
*sb
,
693 struct fid
*fid
, int fh_len
, int fh_type
)
695 struct fuse_inode_handle parent
;
697 if (fh_type
!= 0x82 || fh_len
< 6)
700 parent
.nodeid
= (u64
) fid
->raw
[3] << 32;
701 parent
.nodeid
|= (u64
) fid
->raw
[4];
702 parent
.generation
= fid
->raw
[5];
703 return fuse_get_dentry(sb
, &parent
);
706 static struct dentry
*fuse_get_parent(struct dentry
*child
)
708 struct inode
*child_inode
= child
->d_inode
;
709 struct fuse_conn
*fc
= get_fuse_conn(child_inode
);
711 struct dentry
*parent
;
712 struct fuse_entry_out outarg
;
716 if (!fc
->export_support
)
717 return ERR_PTR(-ESTALE
);
721 err
= fuse_lookup_name(child_inode
->i_sb
, get_node_id(child_inode
),
722 &name
, &outarg
, &inode
);
725 return ERR_PTR(-ESTALE
);
729 parent
= d_obtain_alias(inode
);
730 if (!IS_ERR(parent
) && get_node_id(inode
) != FUSE_ROOT_ID
) {
731 parent
->d_op
= &fuse_dentry_operations
;
732 fuse_invalidate_entry_cache(parent
);
738 static const struct export_operations fuse_export_operations
= {
739 .fh_to_dentry
= fuse_fh_to_dentry
,
740 .fh_to_parent
= fuse_fh_to_parent
,
741 .encode_fh
= fuse_encode_fh
,
742 .get_parent
= fuse_get_parent
,
745 static const struct super_operations fuse_super_operations
= {
746 .alloc_inode
= fuse_alloc_inode
,
747 .destroy_inode
= fuse_destroy_inode
,
748 .clear_inode
= fuse_clear_inode
,
749 .drop_inode
= generic_delete_inode
,
750 .remount_fs
= fuse_remount_fs
,
751 .put_super
= fuse_put_super
,
752 .umount_begin
= fuse_umount_begin
,
753 .statfs
= fuse_statfs
,
754 .show_options
= fuse_show_options
,
757 static void sanitize_global_limit(unsigned *limit
)
760 *limit
= ((num_physpages
<< PAGE_SHIFT
) >> 13) /
761 sizeof(struct fuse_req
);
763 if (*limit
>= 1 << 16)
764 *limit
= (1 << 16) - 1;
767 static int set_global_limit(const char *val
, struct kernel_param
*kp
)
771 rv
= param_set_uint(val
, kp
);
775 sanitize_global_limit((unsigned *)kp
->arg
);
780 static void process_init_limits(struct fuse_conn
*fc
, struct fuse_init_out
*arg
)
782 int cap_sys_admin
= capable(CAP_SYS_ADMIN
);
787 sanitize_global_limit(&max_user_bgreq
);
788 sanitize_global_limit(&max_user_congthresh
);
790 if (arg
->max_background
) {
791 fc
->max_background
= arg
->max_background
;
793 if (!cap_sys_admin
&& fc
->max_background
> max_user_bgreq
)
794 fc
->max_background
= max_user_bgreq
;
796 if (arg
->congestion_threshold
) {
797 fc
->congestion_threshold
= arg
->congestion_threshold
;
799 if (!cap_sys_admin
&&
800 fc
->congestion_threshold
> max_user_congthresh
)
801 fc
->congestion_threshold
= max_user_congthresh
;
805 static void process_init_reply(struct fuse_conn
*fc
, struct fuse_req
*req
)
807 struct fuse_init_out
*arg
= &req
->misc
.init_out
;
809 if (req
->out
.h
.error
|| arg
->major
!= FUSE_KERNEL_VERSION
)
812 unsigned long ra_pages
;
814 process_init_limits(fc
, arg
);
816 if (arg
->minor
>= 6) {
817 ra_pages
= arg
->max_readahead
/ PAGE_CACHE_SIZE
;
818 if (arg
->flags
& FUSE_ASYNC_READ
)
820 if (!(arg
->flags
& FUSE_POSIX_LOCKS
))
822 if (arg
->flags
& FUSE_ATOMIC_O_TRUNC
)
823 fc
->atomic_o_trunc
= 1;
824 if (arg
->minor
>= 9) {
825 /* LOOKUP has dependency on proto version */
826 if (arg
->flags
& FUSE_EXPORT_SUPPORT
)
827 fc
->export_support
= 1;
829 if (arg
->flags
& FUSE_BIG_WRITES
)
831 if (arg
->flags
& FUSE_DONT_MASK
)
834 ra_pages
= fc
->max_read
/ PAGE_CACHE_SIZE
;
838 fc
->bdi
.ra_pages
= min(fc
->bdi
.ra_pages
, ra_pages
);
839 fc
->minor
= arg
->minor
;
840 fc
->max_write
= arg
->minor
< 5 ? 4096 : arg
->max_write
;
841 fc
->max_write
= max_t(unsigned, 4096, fc
->max_write
);
845 wake_up_all(&fc
->blocked_waitq
);
848 static void fuse_send_init(struct fuse_conn
*fc
, struct fuse_req
*req
)
850 struct fuse_init_in
*arg
= &req
->misc
.init_in
;
852 arg
->major
= FUSE_KERNEL_VERSION
;
853 arg
->minor
= FUSE_KERNEL_MINOR_VERSION
;
854 arg
->max_readahead
= fc
->bdi
.ra_pages
* PAGE_CACHE_SIZE
;
855 arg
->flags
|= FUSE_ASYNC_READ
| FUSE_POSIX_LOCKS
| FUSE_ATOMIC_O_TRUNC
|
856 FUSE_EXPORT_SUPPORT
| FUSE_BIG_WRITES
| FUSE_DONT_MASK
;
857 req
->in
.h
.opcode
= FUSE_INIT
;
859 req
->in
.args
[0].size
= sizeof(*arg
);
860 req
->in
.args
[0].value
= arg
;
861 req
->out
.numargs
= 1;
862 /* Variable length arguement used for backward compatibility
863 with interface version < 7.5. Rest of init_out is zeroed
864 by do_get_request(), so a short reply is not a problem */
866 req
->out
.args
[0].size
= sizeof(struct fuse_init_out
);
867 req
->out
.args
[0].value
= &req
->misc
.init_out
;
868 req
->end
= process_init_reply
;
869 fuse_request_send_background(fc
, req
);
872 static void fuse_free_conn(struct fuse_conn
*fc
)
877 static int fuse_bdi_init(struct fuse_conn
*fc
, struct super_block
*sb
)
881 fc
->bdi
.name
= "fuse";
882 fc
->bdi
.ra_pages
= (VM_MAX_READAHEAD
* 1024) / PAGE_CACHE_SIZE
;
883 fc
->bdi
.unplug_io_fn
= default_unplug_io_fn
;
884 /* fuse does it's own writeback accounting */
885 fc
->bdi
.capabilities
= BDI_CAP_NO_ACCT_WB
;
887 err
= bdi_init(&fc
->bdi
);
891 fc
->bdi_initialized
= 1;
894 err
= bdi_register(&fc
->bdi
, NULL
, "%u:%u-fuseblk",
895 MAJOR(fc
->dev
), MINOR(fc
->dev
));
897 err
= bdi_register_dev(&fc
->bdi
, fc
->dev
);
904 * For a single fuse filesystem use max 1% of dirty +
905 * writeback threshold.
907 * This gives about 1M of write buffer for memory maps on a
908 * machine with 1G and 10% dirty_ratio, which should be more
911 * Privileged users can raise it by writing to
913 * /sys/class/bdi/<bdi>/max_ratio
915 bdi_set_max_ratio(&fc
->bdi
, 1);
920 static int fuse_fill_super(struct super_block
*sb
, void *data
, int silent
)
922 struct fuse_conn
*fc
;
924 struct fuse_mount_data d
;
926 struct dentry
*root_dentry
;
927 struct fuse_req
*init_req
;
929 int is_bdev
= sb
->s_bdev
!= NULL
;
932 if (sb
->s_flags
& MS_MANDLOCK
)
935 if (!parse_fuse_opt((char *) data
, &d
, is_bdev
))
941 if (!sb_set_blocksize(sb
, d
.blksize
))
945 sb
->s_blocksize
= PAGE_CACHE_SIZE
;
946 sb
->s_blocksize_bits
= PAGE_CACHE_SHIFT
;
948 sb
->s_magic
= FUSE_SUPER_MAGIC
;
949 sb
->s_op
= &fuse_super_operations
;
950 sb
->s_maxbytes
= MAX_LFS_FILESIZE
;
951 sb
->s_export_op
= &fuse_export_operations
;
958 if (file
->f_op
!= &fuse_dev_operations
)
961 fc
= kmalloc(sizeof(*fc
), GFP_KERNEL
);
970 err
= fuse_bdi_init(fc
, sb
);
974 sb
->s_bdi
= &fc
->bdi
;
976 /* Handle umasking inside the fuse code */
977 if (sb
->s_flags
& MS_POSIXACL
)
979 sb
->s_flags
|= MS_POSIXACL
;
981 fc
->release
= fuse_free_conn
;
983 fc
->user_id
= d
.user_id
;
984 fc
->group_id
= d
.group_id
;
985 fc
->max_read
= max_t(unsigned, 4096, d
.max_read
);
987 /* Used by get_root_inode() */
991 root
= fuse_get_root_inode(sb
, d
.rootmode
);
995 root_dentry
= d_alloc_root(root
);
1001 init_req
= fuse_request_alloc();
1006 fc
->destroy_req
= fuse_request_alloc();
1007 if (!fc
->destroy_req
)
1008 goto err_free_init_req
;
1011 mutex_lock(&fuse_mutex
);
1013 if (file
->private_data
)
1016 err
= fuse_ctl_add_conn(fc
);
1020 list_add_tail(&fc
->entry
, &fuse_conn_list
);
1021 sb
->s_root
= root_dentry
;
1023 file
->private_data
= fuse_conn_get(fc
);
1024 mutex_unlock(&fuse_mutex
);
1026 * atomic_dec_and_test() in fput() provides the necessary
1027 * memory barrier for file->private_data to be visible on all
1032 fuse_send_init(fc
, init_req
);
1037 mutex_unlock(&fuse_mutex
);
1039 fuse_request_free(init_req
);
1043 fuse_bdi_destroy(fc
);
1051 static int fuse_get_sb(struct file_system_type
*fs_type
,
1052 int flags
, const char *dev_name
,
1053 void *raw_data
, struct vfsmount
*mnt
)
1055 return get_sb_nodev(fs_type
, flags
, raw_data
, fuse_fill_super
, mnt
);
1058 static void fuse_kill_sb_anon(struct super_block
*sb
)
1060 struct fuse_conn
*fc
= get_fuse_conn_super(sb
);
1063 down_write(&fc
->killsb
);
1065 up_write(&fc
->killsb
);
1068 kill_anon_super(sb
);
1071 static struct file_system_type fuse_fs_type
= {
1072 .owner
= THIS_MODULE
,
1074 .fs_flags
= FS_HAS_SUBTYPE
,
1075 .get_sb
= fuse_get_sb
,
1076 .kill_sb
= fuse_kill_sb_anon
,
1080 static int fuse_get_sb_blk(struct file_system_type
*fs_type
,
1081 int flags
, const char *dev_name
,
1082 void *raw_data
, struct vfsmount
*mnt
)
1084 return get_sb_bdev(fs_type
, flags
, dev_name
, raw_data
, fuse_fill_super
,
1088 static void fuse_kill_sb_blk(struct super_block
*sb
)
1090 struct fuse_conn
*fc
= get_fuse_conn_super(sb
);
1093 down_write(&fc
->killsb
);
1095 up_write(&fc
->killsb
);
1098 kill_block_super(sb
);
1101 static struct file_system_type fuseblk_fs_type
= {
1102 .owner
= THIS_MODULE
,
1104 .get_sb
= fuse_get_sb_blk
,
1105 .kill_sb
= fuse_kill_sb_blk
,
1106 .fs_flags
= FS_REQUIRES_DEV
| FS_HAS_SUBTYPE
,
1109 static inline int register_fuseblk(void)
1111 return register_filesystem(&fuseblk_fs_type
);
1114 static inline void unregister_fuseblk(void)
1116 unregister_filesystem(&fuseblk_fs_type
);
1119 static inline int register_fuseblk(void)
1124 static inline void unregister_fuseblk(void)
1129 static void fuse_inode_init_once(void *foo
)
1131 struct inode
*inode
= foo
;
1133 inode_init_once(inode
);
1136 static int __init
fuse_fs_init(void)
1140 err
= register_filesystem(&fuse_fs_type
);
1144 err
= register_fuseblk();
1148 fuse_inode_cachep
= kmem_cache_create("fuse_inode",
1149 sizeof(struct fuse_inode
),
1150 0, SLAB_HWCACHE_ALIGN
,
1151 fuse_inode_init_once
);
1153 if (!fuse_inode_cachep
)
1159 unregister_fuseblk();
1161 unregister_filesystem(&fuse_fs_type
);
1166 static void fuse_fs_cleanup(void)
1168 unregister_filesystem(&fuse_fs_type
);
1169 unregister_fuseblk();
1170 kmem_cache_destroy(fuse_inode_cachep
);
1173 static struct kobject
*fuse_kobj
;
1174 static struct kobject
*connections_kobj
;
1176 static int fuse_sysfs_init(void)
1180 fuse_kobj
= kobject_create_and_add("fuse", fs_kobj
);
1186 connections_kobj
= kobject_create_and_add("connections", fuse_kobj
);
1187 if (!connections_kobj
) {
1189 goto out_fuse_unregister
;
1194 out_fuse_unregister
:
1195 kobject_put(fuse_kobj
);
1200 static void fuse_sysfs_cleanup(void)
1202 kobject_put(connections_kobj
);
1203 kobject_put(fuse_kobj
);
1206 static int __init
fuse_init(void)
1210 printk(KERN_INFO
"fuse init (API version %i.%i)\n",
1211 FUSE_KERNEL_VERSION
, FUSE_KERNEL_MINOR_VERSION
);
1213 INIT_LIST_HEAD(&fuse_conn_list
);
1214 res
= fuse_fs_init();
1218 res
= fuse_dev_init();
1220 goto err_fs_cleanup
;
1222 res
= fuse_sysfs_init();
1224 goto err_dev_cleanup
;
1226 res
= fuse_ctl_init();
1228 goto err_sysfs_cleanup
;
1230 sanitize_global_limit(&max_user_bgreq
);
1231 sanitize_global_limit(&max_user_congthresh
);
1236 fuse_sysfs_cleanup();
1245 static void __exit
fuse_exit(void)
1247 printk(KERN_DEBUG
"fuse exit\n");
1250 fuse_sysfs_cleanup();
1255 module_init(fuse_init
);
1256 module_exit(fuse_exit
);