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/kernel.h>
15 static const struct file_operations fuse_direct_io_file_operations
;
17 static int fuse_send_open(struct inode
*inode
, struct file
*file
, int isdir
,
18 struct fuse_open_out
*outargp
)
20 struct fuse_conn
*fc
= get_fuse_conn(inode
);
21 struct fuse_open_in inarg
;
25 req
= fuse_get_req(fc
);
29 memset(&inarg
, 0, sizeof(inarg
));
30 inarg
.flags
= file
->f_flags
& ~(O_CREAT
| O_EXCL
| O_NOCTTY
| O_TRUNC
);
31 req
->in
.h
.opcode
= isdir
? FUSE_OPENDIR
: FUSE_OPEN
;
32 req
->in
.h
.nodeid
= get_node_id(inode
);
34 req
->in
.args
[0].size
= sizeof(inarg
);
35 req
->in
.args
[0].value
= &inarg
;
37 req
->out
.args
[0].size
= sizeof(*outargp
);
38 req
->out
.args
[0].value
= outargp
;
39 request_send(fc
, req
);
40 err
= req
->out
.h
.error
;
41 fuse_put_request(fc
, req
);
46 struct fuse_file
*fuse_file_alloc(void)
49 ff
= kmalloc(sizeof(struct fuse_file
), GFP_KERNEL
);
51 ff
->reserved_req
= fuse_request_alloc();
52 if (!ff
->reserved_req
) {
60 void fuse_file_free(struct fuse_file
*ff
)
62 fuse_request_free(ff
->reserved_req
);
66 void fuse_finish_open(struct inode
*inode
, struct file
*file
,
67 struct fuse_file
*ff
, struct fuse_open_out
*outarg
)
69 if (outarg
->open_flags
& FOPEN_DIRECT_IO
)
70 file
->f_op
= &fuse_direct_io_file_operations
;
71 if (!(outarg
->open_flags
& FOPEN_KEEP_CACHE
))
72 invalidate_inode_pages(inode
->i_mapping
);
74 file
->private_data
= ff
;
77 int fuse_open_common(struct inode
*inode
, struct file
*file
, int isdir
)
79 struct fuse_open_out outarg
;
83 /* VFS checks this, but only _after_ ->open() */
84 if (file
->f_flags
& O_DIRECT
)
87 err
= generic_file_open(inode
, file
);
91 /* If opening the root node, no lookup has been performed on
92 it, so the attributes must be refreshed */
93 if (get_node_id(inode
) == FUSE_ROOT_ID
) {
94 err
= fuse_do_getattr(inode
);
99 ff
= fuse_file_alloc();
103 err
= fuse_send_open(inode
, file
, isdir
, &outarg
);
108 outarg
.open_flags
&= ~FOPEN_DIRECT_IO
;
109 fuse_finish_open(inode
, file
, ff
, &outarg
);
115 struct fuse_req
*fuse_release_fill(struct fuse_file
*ff
, u64 nodeid
, int flags
,
118 struct fuse_req
*req
= ff
->reserved_req
;
119 struct fuse_release_in
*inarg
= &req
->misc
.release_in
;
122 inarg
->flags
= flags
;
123 req
->in
.h
.opcode
= opcode
;
124 req
->in
.h
.nodeid
= nodeid
;
126 req
->in
.args
[0].size
= sizeof(struct fuse_release_in
);
127 req
->in
.args
[0].value
= inarg
;
133 int fuse_release_common(struct inode
*inode
, struct file
*file
, int isdir
)
135 struct fuse_file
*ff
= file
->private_data
;
137 struct fuse_conn
*fc
= get_fuse_conn(inode
);
138 struct fuse_req
*req
;
140 req
= fuse_release_fill(ff
, get_node_id(inode
), file
->f_flags
,
141 isdir
? FUSE_RELEASEDIR
: FUSE_RELEASE
);
143 /* Hold vfsmount and dentry until release is finished */
144 req
->vfsmount
= mntget(file
->f_vfsmnt
);
145 req
->dentry
= dget(file
->f_dentry
);
146 request_send_background(fc
, req
);
149 /* Return value is ignored by VFS */
153 static int fuse_open(struct inode
*inode
, struct file
*file
)
155 return fuse_open_common(inode
, file
, 0);
158 static int fuse_release(struct inode
*inode
, struct file
*file
)
160 return fuse_release_common(inode
, file
, 0);
164 * Scramble the ID space with XTEA, so that the value of the files_struct
165 * pointer is not exposed to userspace.
167 static u64
fuse_lock_owner_id(struct fuse_conn
*fc
, fl_owner_t id
)
169 u32
*k
= fc
->scramble_key
;
170 u64 v
= (unsigned long) id
;
176 for (i
= 0; i
< 32; i
++) {
177 v0
+= ((v1
<< 4 ^ v1
>> 5) + v1
) ^ (sum
+ k
[sum
& 3]);
179 v1
+= ((v0
<< 4 ^ v0
>> 5) + v0
) ^ (sum
+ k
[sum
>>11 & 3]);
182 return (u64
) v0
+ ((u64
) v1
<< 32);
185 static int fuse_flush(struct file
*file
, fl_owner_t id
)
187 struct inode
*inode
= file
->f_dentry
->d_inode
;
188 struct fuse_conn
*fc
= get_fuse_conn(inode
);
189 struct fuse_file
*ff
= file
->private_data
;
190 struct fuse_req
*req
;
191 struct fuse_flush_in inarg
;
194 if (is_bad_inode(inode
))
200 req
= fuse_get_req_nofail(fc
, file
);
201 memset(&inarg
, 0, sizeof(inarg
));
203 inarg
.lock_owner
= fuse_lock_owner_id(fc
, id
);
204 req
->in
.h
.opcode
= FUSE_FLUSH
;
205 req
->in
.h
.nodeid
= get_node_id(inode
);
207 req
->in
.args
[0].size
= sizeof(inarg
);
208 req
->in
.args
[0].value
= &inarg
;
210 request_send(fc
, req
);
211 err
= req
->out
.h
.error
;
212 fuse_put_request(fc
, req
);
213 if (err
== -ENOSYS
) {
220 int fuse_fsync_common(struct file
*file
, struct dentry
*de
, int datasync
,
223 struct inode
*inode
= de
->d_inode
;
224 struct fuse_conn
*fc
= get_fuse_conn(inode
);
225 struct fuse_file
*ff
= file
->private_data
;
226 struct fuse_req
*req
;
227 struct fuse_fsync_in inarg
;
230 if (is_bad_inode(inode
))
233 if ((!isdir
&& fc
->no_fsync
) || (isdir
&& fc
->no_fsyncdir
))
236 req
= fuse_get_req(fc
);
240 memset(&inarg
, 0, sizeof(inarg
));
242 inarg
.fsync_flags
= datasync
? 1 : 0;
243 req
->in
.h
.opcode
= isdir
? FUSE_FSYNCDIR
: FUSE_FSYNC
;
244 req
->in
.h
.nodeid
= get_node_id(inode
);
246 req
->in
.args
[0].size
= sizeof(inarg
);
247 req
->in
.args
[0].value
= &inarg
;
248 request_send(fc
, req
);
249 err
= req
->out
.h
.error
;
250 fuse_put_request(fc
, req
);
251 if (err
== -ENOSYS
) {
261 static int fuse_fsync(struct file
*file
, struct dentry
*de
, int datasync
)
263 return fuse_fsync_common(file
, de
, datasync
, 0);
266 void fuse_read_fill(struct fuse_req
*req
, struct file
*file
,
267 struct inode
*inode
, loff_t pos
, size_t count
, int opcode
)
269 struct fuse_file
*ff
= file
->private_data
;
270 struct fuse_read_in
*inarg
= &req
->misc
.read_in
;
275 req
->in
.h
.opcode
= opcode
;
276 req
->in
.h
.nodeid
= get_node_id(inode
);
278 req
->in
.args
[0].size
= sizeof(struct fuse_read_in
);
279 req
->in
.args
[0].value
= inarg
;
280 req
->out
.argpages
= 1;
282 req
->out
.numargs
= 1;
283 req
->out
.args
[0].size
= count
;
286 static size_t fuse_send_read(struct fuse_req
*req
, struct file
*file
,
287 struct inode
*inode
, loff_t pos
, size_t count
)
289 struct fuse_conn
*fc
= get_fuse_conn(inode
);
290 fuse_read_fill(req
, file
, inode
, pos
, count
, FUSE_READ
);
291 request_send(fc
, req
);
292 return req
->out
.args
[0].size
;
295 static int fuse_readpage(struct file
*file
, struct page
*page
)
297 struct inode
*inode
= page
->mapping
->host
;
298 struct fuse_conn
*fc
= get_fuse_conn(inode
);
299 struct fuse_req
*req
;
303 if (is_bad_inode(inode
))
306 req
= fuse_get_req(fc
);
311 req
->out
.page_zeroing
= 1;
313 req
->pages
[0] = page
;
314 fuse_send_read(req
, file
, inode
, page_offset(page
), PAGE_CACHE_SIZE
);
315 err
= req
->out
.h
.error
;
316 fuse_put_request(fc
, req
);
318 SetPageUptodate(page
);
319 fuse_invalidate_attr(inode
); /* atime changed */
325 static void fuse_readpages_end(struct fuse_conn
*fc
, struct fuse_req
*req
)
329 fuse_invalidate_attr(req
->pages
[0]->mapping
->host
); /* atime changed */
331 for (i
= 0; i
< req
->num_pages
; i
++) {
332 struct page
*page
= req
->pages
[i
];
333 if (!req
->out
.h
.error
)
334 SetPageUptodate(page
);
339 fuse_put_request(fc
, req
);
342 static void fuse_send_readpages(struct fuse_req
*req
, struct file
*file
,
345 struct fuse_conn
*fc
= get_fuse_conn(inode
);
346 loff_t pos
= page_offset(req
->pages
[0]);
347 size_t count
= req
->num_pages
<< PAGE_CACHE_SHIFT
;
348 req
->out
.page_zeroing
= 1;
349 fuse_read_fill(req
, file
, inode
, pos
, count
, FUSE_READ
);
350 if (fc
->async_read
) {
353 req
->end
= fuse_readpages_end
;
354 request_send_background(fc
, req
);
356 request_send(fc
, req
);
357 fuse_readpages_end(fc
, req
);
361 struct fuse_readpages_data
{
362 struct fuse_req
*req
;
367 static int fuse_readpages_fill(void *_data
, struct page
*page
)
369 struct fuse_readpages_data
*data
= _data
;
370 struct fuse_req
*req
= data
->req
;
371 struct inode
*inode
= data
->inode
;
372 struct fuse_conn
*fc
= get_fuse_conn(inode
);
374 if (req
->num_pages
&&
375 (req
->num_pages
== FUSE_MAX_PAGES_PER_REQ
||
376 (req
->num_pages
+ 1) * PAGE_CACHE_SIZE
> fc
->max_read
||
377 req
->pages
[req
->num_pages
- 1]->index
+ 1 != page
->index
)) {
378 fuse_send_readpages(req
, data
->file
, inode
);
379 data
->req
= req
= fuse_get_req(fc
);
385 req
->pages
[req
->num_pages
] = page
;
390 static int fuse_readpages(struct file
*file
, struct address_space
*mapping
,
391 struct list_head
*pages
, unsigned nr_pages
)
393 struct inode
*inode
= mapping
->host
;
394 struct fuse_conn
*fc
= get_fuse_conn(inode
);
395 struct fuse_readpages_data data
;
398 if (is_bad_inode(inode
))
403 data
.req
= fuse_get_req(fc
);
404 if (IS_ERR(data
.req
))
405 return PTR_ERR(data
.req
);
407 err
= read_cache_pages(mapping
, pages
, fuse_readpages_fill
, &data
);
409 if (data
.req
->num_pages
)
410 fuse_send_readpages(data
.req
, file
, inode
);
412 fuse_put_request(fc
, data
.req
);
417 static size_t fuse_send_write(struct fuse_req
*req
, struct file
*file
,
418 struct inode
*inode
, loff_t pos
, size_t count
)
420 struct fuse_conn
*fc
= get_fuse_conn(inode
);
421 struct fuse_file
*ff
= file
->private_data
;
422 struct fuse_write_in inarg
;
423 struct fuse_write_out outarg
;
425 memset(&inarg
, 0, sizeof(struct fuse_write_in
));
429 req
->in
.h
.opcode
= FUSE_WRITE
;
430 req
->in
.h
.nodeid
= get_node_id(inode
);
431 req
->in
.argpages
= 1;
433 req
->in
.args
[0].size
= sizeof(struct fuse_write_in
);
434 req
->in
.args
[0].value
= &inarg
;
435 req
->in
.args
[1].size
= count
;
436 req
->out
.numargs
= 1;
437 req
->out
.args
[0].size
= sizeof(struct fuse_write_out
);
438 req
->out
.args
[0].value
= &outarg
;
439 request_send(fc
, req
);
443 static int fuse_prepare_write(struct file
*file
, struct page
*page
,
444 unsigned offset
, unsigned to
)
450 static int fuse_commit_write(struct file
*file
, struct page
*page
,
451 unsigned offset
, unsigned to
)
455 unsigned count
= to
- offset
;
456 struct inode
*inode
= page
->mapping
->host
;
457 struct fuse_conn
*fc
= get_fuse_conn(inode
);
458 loff_t pos
= page_offset(page
) + offset
;
459 struct fuse_req
*req
;
461 if (is_bad_inode(inode
))
464 req
= fuse_get_req(fc
);
469 req
->pages
[0] = page
;
470 req
->page_offset
= offset
;
471 nres
= fuse_send_write(req
, file
, inode
, pos
, count
);
472 err
= req
->out
.h
.error
;
473 fuse_put_request(fc
, req
);
474 if (!err
&& nres
!= count
)
478 if (pos
> i_size_read(inode
))
479 i_size_write(inode
, pos
);
481 if (offset
== 0 && to
== PAGE_CACHE_SIZE
) {
482 clear_page_dirty(page
);
483 SetPageUptodate(page
);
486 fuse_invalidate_attr(inode
);
490 static void fuse_release_user_pages(struct fuse_req
*req
, int write
)
494 for (i
= 0; i
< req
->num_pages
; i
++) {
495 struct page
*page
= req
->pages
[i
];
497 set_page_dirty_lock(page
);
502 static int fuse_get_user_pages(struct fuse_req
*req
, const char __user
*buf
,
503 unsigned nbytes
, int write
)
505 unsigned long user_addr
= (unsigned long) buf
;
506 unsigned offset
= user_addr
& ~PAGE_MASK
;
509 /* This doesn't work with nfsd */
513 nbytes
= min(nbytes
, (unsigned) FUSE_MAX_PAGES_PER_REQ
<< PAGE_SHIFT
);
514 npages
= (nbytes
+ offset
+ PAGE_SIZE
- 1) >> PAGE_SHIFT
;
515 npages
= min(max(npages
, 1), FUSE_MAX_PAGES_PER_REQ
);
516 down_read(¤t
->mm
->mmap_sem
);
517 npages
= get_user_pages(current
, current
->mm
, user_addr
, npages
, write
,
518 0, req
->pages
, NULL
);
519 up_read(¤t
->mm
->mmap_sem
);
523 req
->num_pages
= npages
;
524 req
->page_offset
= offset
;
528 static ssize_t
fuse_direct_io(struct file
*file
, const char __user
*buf
,
529 size_t count
, loff_t
*ppos
, int write
)
531 struct inode
*inode
= file
->f_dentry
->d_inode
;
532 struct fuse_conn
*fc
= get_fuse_conn(inode
);
533 size_t nmax
= write
? fc
->max_write
: fc
->max_read
;
536 struct fuse_req
*req
;
538 if (is_bad_inode(inode
))
541 req
= fuse_get_req(fc
);
547 size_t nbytes
= min(count
, nmax
);
548 int err
= fuse_get_user_pages(req
, buf
, nbytes
, !write
);
553 nbytes
= (req
->num_pages
<< PAGE_SHIFT
) - req
->page_offset
;
554 nbytes
= min(count
, nbytes
);
556 nres
= fuse_send_write(req
, file
, inode
, pos
, nbytes
);
558 nres
= fuse_send_read(req
, file
, inode
, pos
, nbytes
);
559 fuse_release_user_pages(req
, !write
);
560 if (req
->out
.h
.error
) {
562 res
= req
->out
.h
.error
;
564 } else if (nres
> nbytes
) {
575 fuse_put_request(fc
, req
);
576 req
= fuse_get_req(fc
);
581 fuse_put_request(fc
, req
);
583 if (write
&& pos
> i_size_read(inode
))
584 i_size_write(inode
, pos
);
587 fuse_invalidate_attr(inode
);
592 static ssize_t
fuse_direct_read(struct file
*file
, char __user
*buf
,
593 size_t count
, loff_t
*ppos
)
595 return fuse_direct_io(file
, buf
, count
, ppos
, 0);
598 static ssize_t
fuse_direct_write(struct file
*file
, const char __user
*buf
,
599 size_t count
, loff_t
*ppos
)
601 struct inode
*inode
= file
->f_dentry
->d_inode
;
603 /* Don't allow parallel writes to the same file */
604 mutex_lock(&inode
->i_mutex
);
605 res
= fuse_direct_io(file
, buf
, count
, ppos
, 1);
606 mutex_unlock(&inode
->i_mutex
);
610 static int fuse_file_mmap(struct file
*file
, struct vm_area_struct
*vma
)
612 if ((vma
->vm_flags
& VM_SHARED
)) {
613 if ((vma
->vm_flags
& VM_WRITE
))
616 vma
->vm_flags
&= ~VM_MAYWRITE
;
618 return generic_file_mmap(file
, vma
);
621 static int fuse_set_page_dirty(struct page
*page
)
623 printk("fuse_set_page_dirty: should not happen\n");
628 static int convert_fuse_file_lock(const struct fuse_file_lock
*ffl
,
629 struct file_lock
*fl
)
637 if (ffl
->start
> OFFSET_MAX
|| ffl
->end
> OFFSET_MAX
||
638 ffl
->end
< ffl
->start
)
641 fl
->fl_start
= ffl
->start
;
642 fl
->fl_end
= ffl
->end
;
643 fl
->fl_pid
= ffl
->pid
;
649 fl
->fl_type
= ffl
->type
;
653 static void fuse_lk_fill(struct fuse_req
*req
, struct file
*file
,
654 const struct file_lock
*fl
, int opcode
, pid_t pid
)
656 struct inode
*inode
= file
->f_dentry
->d_inode
;
657 struct fuse_conn
*fc
= get_fuse_conn(inode
);
658 struct fuse_file
*ff
= file
->private_data
;
659 struct fuse_lk_in
*arg
= &req
->misc
.lk_in
;
662 arg
->owner
= fuse_lock_owner_id(fc
, fl
->fl_owner
);
663 arg
->lk
.start
= fl
->fl_start
;
664 arg
->lk
.end
= fl
->fl_end
;
665 arg
->lk
.type
= fl
->fl_type
;
667 req
->in
.h
.opcode
= opcode
;
668 req
->in
.h
.nodeid
= get_node_id(inode
);
670 req
->in
.args
[0].size
= sizeof(*arg
);
671 req
->in
.args
[0].value
= arg
;
674 static int fuse_getlk(struct file
*file
, struct file_lock
*fl
)
676 struct inode
*inode
= file
->f_dentry
->d_inode
;
677 struct fuse_conn
*fc
= get_fuse_conn(inode
);
678 struct fuse_req
*req
;
679 struct fuse_lk_out outarg
;
682 req
= fuse_get_req(fc
);
686 fuse_lk_fill(req
, file
, fl
, FUSE_GETLK
, 0);
687 req
->out
.numargs
= 1;
688 req
->out
.args
[0].size
= sizeof(outarg
);
689 req
->out
.args
[0].value
= &outarg
;
690 request_send(fc
, req
);
691 err
= req
->out
.h
.error
;
692 fuse_put_request(fc
, req
);
694 err
= convert_fuse_file_lock(&outarg
.lk
, fl
);
699 static int fuse_setlk(struct file
*file
, struct file_lock
*fl
)
701 struct inode
*inode
= file
->f_dentry
->d_inode
;
702 struct fuse_conn
*fc
= get_fuse_conn(inode
);
703 struct fuse_req
*req
;
704 int opcode
= (fl
->fl_flags
& FL_SLEEP
) ? FUSE_SETLKW
: FUSE_SETLK
;
705 pid_t pid
= fl
->fl_type
!= F_UNLCK
? current
->tgid
: 0;
708 /* Unlock on close is handled by the flush method */
709 if (fl
->fl_flags
& FL_CLOSE
)
712 req
= fuse_get_req(fc
);
716 fuse_lk_fill(req
, file
, fl
, opcode
, pid
);
717 request_send(fc
, req
);
718 err
= req
->out
.h
.error
;
719 /* locking is restartable */
722 fuse_put_request(fc
, req
);
726 static int fuse_file_lock(struct file
*file
, int cmd
, struct file_lock
*fl
)
728 struct inode
*inode
= file
->f_dentry
->d_inode
;
729 struct fuse_conn
*fc
= get_fuse_conn(inode
);
732 if (cmd
== F_GETLK
) {
734 if (!posix_test_lock(file
, fl
, fl
))
735 fl
->fl_type
= F_UNLCK
;
738 err
= fuse_getlk(file
, fl
);
741 err
= posix_lock_file_wait(file
, fl
);
743 err
= fuse_setlk(file
, fl
);
748 static const struct file_operations fuse_file_operations
= {
749 .llseek
= generic_file_llseek
,
750 .read
= generic_file_read
,
751 .write
= generic_file_write
,
752 .mmap
= fuse_file_mmap
,
755 .release
= fuse_release
,
757 .lock
= fuse_file_lock
,
758 .sendfile
= generic_file_sendfile
,
761 static const struct file_operations fuse_direct_io_file_operations
= {
762 .llseek
= generic_file_llseek
,
763 .read
= fuse_direct_read
,
764 .write
= fuse_direct_write
,
767 .release
= fuse_release
,
769 .lock
= fuse_file_lock
,
770 /* no mmap and sendfile */
773 static const struct address_space_operations fuse_file_aops
= {
774 .readpage
= fuse_readpage
,
775 .prepare_write
= fuse_prepare_write
,
776 .commit_write
= fuse_commit_write
,
777 .readpages
= fuse_readpages
,
778 .set_page_dirty
= fuse_set_page_dirty
,
781 void fuse_init_file_inode(struct inode
*inode
)
783 inode
->i_fop
= &fuse_file_operations
;
784 inode
->i_data
.a_ops
= &fuse_file_aops
;