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/kernel.h>
14 #include <linux/sched.h>
15 #include <linux/module.h>
16 #include <linux/compat.h>
17 #include <linux/swap.h>
19 static const struct file_operations fuse_direct_io_file_operations
;
21 static int fuse_send_open(struct fuse_conn
*fc
, u64 nodeid
, struct file
*file
,
22 int opcode
, struct fuse_open_out
*outargp
)
24 struct fuse_open_in inarg
;
28 req
= fuse_get_req_nopages(fc
);
32 memset(&inarg
, 0, sizeof(inarg
));
33 inarg
.flags
= file
->f_flags
& ~(O_CREAT
| O_EXCL
| O_NOCTTY
);
34 if (!fc
->atomic_o_trunc
)
35 inarg
.flags
&= ~O_TRUNC
;
36 req
->in
.h
.opcode
= opcode
;
37 req
->in
.h
.nodeid
= nodeid
;
39 req
->in
.args
[0].size
= sizeof(inarg
);
40 req
->in
.args
[0].value
= &inarg
;
42 req
->out
.args
[0].size
= sizeof(*outargp
);
43 req
->out
.args
[0].value
= outargp
;
44 fuse_request_send(fc
, req
);
45 err
= req
->out
.h
.error
;
46 fuse_put_request(fc
, req
);
51 struct fuse_file
*fuse_file_alloc(struct fuse_conn
*fc
)
55 ff
= kmalloc(sizeof(struct fuse_file
), GFP_KERNEL
);
60 ff
->reserved_req
= fuse_request_alloc(0);
61 if (unlikely(!ff
->reserved_req
)) {
66 INIT_LIST_HEAD(&ff
->write_entry
);
67 atomic_set(&ff
->count
, 0);
68 RB_CLEAR_NODE(&ff
->polled_node
);
69 init_waitqueue_head(&ff
->poll_wait
);
73 spin_unlock(&fc
->lock
);
78 void fuse_file_free(struct fuse_file
*ff
)
80 fuse_request_free(ff
->reserved_req
);
84 struct fuse_file
*fuse_file_get(struct fuse_file
*ff
)
86 atomic_inc(&ff
->count
);
90 static void fuse_release_async(struct work_struct
*work
)
96 req
= container_of(work
, struct fuse_req
, misc
.release
.work
);
97 path
= req
->misc
.release
.path
;
98 fc
= get_fuse_conn(path
.dentry
->d_inode
);
100 fuse_put_request(fc
, req
);
104 static void fuse_release_end(struct fuse_conn
*fc
, struct fuse_req
*req
)
106 if (fc
->destroy_req
) {
108 * If this is a fuseblk mount, then it's possible that
109 * releasing the path will result in releasing the
110 * super block and sending the DESTROY request. If
111 * the server is single threaded, this would hang.
112 * For this reason do the path_put() in a separate
115 atomic_inc(&req
->count
);
116 INIT_WORK(&req
->misc
.release
.work
, fuse_release_async
);
117 schedule_work(&req
->misc
.release
.work
);
119 path_put(&req
->misc
.release
.path
);
123 static void fuse_file_put(struct fuse_file
*ff
, bool sync
)
125 if (atomic_dec_and_test(&ff
->count
)) {
126 struct fuse_req
*req
= ff
->reserved_req
;
129 fuse_request_send(ff
->fc
, req
);
130 path_put(&req
->misc
.release
.path
);
131 fuse_put_request(ff
->fc
, req
);
133 req
->end
= fuse_release_end
;
134 fuse_request_send_background(ff
->fc
, req
);
140 int fuse_do_open(struct fuse_conn
*fc
, u64 nodeid
, struct file
*file
,
143 struct fuse_open_out outarg
;
144 struct fuse_file
*ff
;
146 int opcode
= isdir
? FUSE_OPENDIR
: FUSE_OPEN
;
148 ff
= fuse_file_alloc(fc
);
152 err
= fuse_send_open(fc
, nodeid
, file
, opcode
, &outarg
);
159 outarg
.open_flags
&= ~FOPEN_DIRECT_IO
;
163 ff
->open_flags
= outarg
.open_flags
;
164 file
->private_data
= fuse_file_get(ff
);
168 EXPORT_SYMBOL_GPL(fuse_do_open
);
170 void fuse_finish_open(struct inode
*inode
, struct file
*file
)
172 struct fuse_file
*ff
= file
->private_data
;
173 struct fuse_conn
*fc
= get_fuse_conn(inode
);
175 if (ff
->open_flags
& FOPEN_DIRECT_IO
)
176 file
->f_op
= &fuse_direct_io_file_operations
;
177 if (!(ff
->open_flags
& FOPEN_KEEP_CACHE
))
178 invalidate_inode_pages2(inode
->i_mapping
);
179 if (ff
->open_flags
& FOPEN_NONSEEKABLE
)
180 nonseekable_open(inode
, file
);
181 if (fc
->atomic_o_trunc
&& (file
->f_flags
& O_TRUNC
)) {
182 struct fuse_inode
*fi
= get_fuse_inode(inode
);
184 spin_lock(&fc
->lock
);
185 fi
->attr_version
= ++fc
->attr_version
;
186 i_size_write(inode
, 0);
187 spin_unlock(&fc
->lock
);
188 fuse_invalidate_attr(inode
);
192 int fuse_open_common(struct inode
*inode
, struct file
*file
, bool isdir
)
194 struct fuse_conn
*fc
= get_fuse_conn(inode
);
197 err
= generic_file_open(inode
, file
);
201 err
= fuse_do_open(fc
, get_node_id(inode
), file
, isdir
);
205 fuse_finish_open(inode
, file
);
210 static void fuse_prepare_release(struct fuse_file
*ff
, int flags
, int opcode
)
212 struct fuse_conn
*fc
= ff
->fc
;
213 struct fuse_req
*req
= ff
->reserved_req
;
214 struct fuse_release_in
*inarg
= &req
->misc
.release
.in
;
216 spin_lock(&fc
->lock
);
217 list_del(&ff
->write_entry
);
218 if (!RB_EMPTY_NODE(&ff
->polled_node
))
219 rb_erase(&ff
->polled_node
, &fc
->polled_files
);
220 spin_unlock(&fc
->lock
);
222 wake_up_interruptible_all(&ff
->poll_wait
);
225 inarg
->flags
= flags
;
226 req
->in
.h
.opcode
= opcode
;
227 req
->in
.h
.nodeid
= ff
->nodeid
;
229 req
->in
.args
[0].size
= sizeof(struct fuse_release_in
);
230 req
->in
.args
[0].value
= inarg
;
233 void fuse_release_common(struct file
*file
, int opcode
)
235 struct fuse_file
*ff
;
236 struct fuse_req
*req
;
238 ff
= file
->private_data
;
242 req
= ff
->reserved_req
;
243 fuse_prepare_release(ff
, file
->f_flags
, opcode
);
246 struct fuse_release_in
*inarg
= &req
->misc
.release
.in
;
247 inarg
->release_flags
|= FUSE_RELEASE_FLOCK_UNLOCK
;
248 inarg
->lock_owner
= fuse_lock_owner_id(ff
->fc
,
251 /* Hold vfsmount and dentry until release is finished */
252 path_get(&file
->f_path
);
253 req
->misc
.release
.path
= file
->f_path
;
256 * Normally this will send the RELEASE request, however if
257 * some asynchronous READ or WRITE requests are outstanding,
258 * the sending will be delayed.
260 * Make the release synchronous if this is a fuseblk mount,
261 * synchronous RELEASE is allowed (and desirable) in this case
262 * because the server can be trusted not to screw up.
264 fuse_file_put(ff
, ff
->fc
->destroy_req
!= NULL
);
267 static int fuse_open(struct inode
*inode
, struct file
*file
)
269 return fuse_open_common(inode
, file
, false);
272 static int fuse_release(struct inode
*inode
, struct file
*file
)
274 fuse_release_common(file
, FUSE_RELEASE
);
276 /* return value is ignored by VFS */
280 void fuse_sync_release(struct fuse_file
*ff
, int flags
)
282 WARN_ON(atomic_read(&ff
->count
) > 1);
283 fuse_prepare_release(ff
, flags
, FUSE_RELEASE
);
284 ff
->reserved_req
->force
= 1;
285 fuse_request_send(ff
->fc
, ff
->reserved_req
);
286 fuse_put_request(ff
->fc
, ff
->reserved_req
);
289 EXPORT_SYMBOL_GPL(fuse_sync_release
);
292 * Scramble the ID space with XTEA, so that the value of the files_struct
293 * pointer is not exposed to userspace.
295 u64
fuse_lock_owner_id(struct fuse_conn
*fc
, fl_owner_t id
)
297 u32
*k
= fc
->scramble_key
;
298 u64 v
= (unsigned long) id
;
304 for (i
= 0; i
< 32; i
++) {
305 v0
+= ((v1
<< 4 ^ v1
>> 5) + v1
) ^ (sum
+ k
[sum
& 3]);
307 v1
+= ((v0
<< 4 ^ v0
>> 5) + v0
) ^ (sum
+ k
[sum
>>11 & 3]);
310 return (u64
) v0
+ ((u64
) v1
<< 32);
314 * Check if page is under writeback
316 * This is currently done by walking the list of writepage requests
317 * for the inode, which can be pretty inefficient.
319 static bool fuse_page_is_writeback(struct inode
*inode
, pgoff_t index
)
321 struct fuse_conn
*fc
= get_fuse_conn(inode
);
322 struct fuse_inode
*fi
= get_fuse_inode(inode
);
323 struct fuse_req
*req
;
326 spin_lock(&fc
->lock
);
327 list_for_each_entry(req
, &fi
->writepages
, writepages_entry
) {
330 BUG_ON(req
->inode
!= inode
);
331 curr_index
= req
->misc
.write
.in
.offset
>> PAGE_CACHE_SHIFT
;
332 if (curr_index
== index
) {
337 spin_unlock(&fc
->lock
);
343 * Wait for page writeback to be completed.
345 * Since fuse doesn't rely on the VM writeback tracking, this has to
346 * use some other means.
348 static int fuse_wait_on_page_writeback(struct inode
*inode
, pgoff_t index
)
350 struct fuse_inode
*fi
= get_fuse_inode(inode
);
352 wait_event(fi
->page_waitq
, !fuse_page_is_writeback(inode
, index
));
356 static int fuse_flush(struct file
*file
, fl_owner_t id
)
358 struct inode
*inode
= file_inode(file
);
359 struct fuse_conn
*fc
= get_fuse_conn(inode
);
360 struct fuse_file
*ff
= file
->private_data
;
361 struct fuse_req
*req
;
362 struct fuse_flush_in inarg
;
365 if (is_bad_inode(inode
))
371 req
= fuse_get_req_nofail_nopages(fc
, file
);
372 memset(&inarg
, 0, sizeof(inarg
));
374 inarg
.lock_owner
= fuse_lock_owner_id(fc
, id
);
375 req
->in
.h
.opcode
= FUSE_FLUSH
;
376 req
->in
.h
.nodeid
= get_node_id(inode
);
378 req
->in
.args
[0].size
= sizeof(inarg
);
379 req
->in
.args
[0].value
= &inarg
;
381 fuse_request_send(fc
, req
);
382 err
= req
->out
.h
.error
;
383 fuse_put_request(fc
, req
);
384 if (err
== -ENOSYS
) {
392 * Wait for all pending writepages on the inode to finish.
394 * This is currently done by blocking further writes with FUSE_NOWRITE
395 * and waiting for all sent writes to complete.
397 * This must be called under i_mutex, otherwise the FUSE_NOWRITE usage
398 * could conflict with truncation.
400 static void fuse_sync_writes(struct inode
*inode
)
402 fuse_set_nowrite(inode
);
403 fuse_release_nowrite(inode
);
406 int fuse_fsync_common(struct file
*file
, loff_t start
, loff_t end
,
407 int datasync
, int isdir
)
409 struct inode
*inode
= file
->f_mapping
->host
;
410 struct fuse_conn
*fc
= get_fuse_conn(inode
);
411 struct fuse_file
*ff
= file
->private_data
;
412 struct fuse_req
*req
;
413 struct fuse_fsync_in inarg
;
416 if (is_bad_inode(inode
))
419 err
= filemap_write_and_wait_range(inode
->i_mapping
, start
, end
);
423 if ((!isdir
&& fc
->no_fsync
) || (isdir
&& fc
->no_fsyncdir
))
426 mutex_lock(&inode
->i_mutex
);
429 * Start writeback against all dirty pages of the inode, then
430 * wait for all outstanding writes, before sending the FSYNC
433 err
= write_inode_now(inode
, 0);
437 fuse_sync_writes(inode
);
439 req
= fuse_get_req_nopages(fc
);
445 memset(&inarg
, 0, sizeof(inarg
));
447 inarg
.fsync_flags
= datasync
? 1 : 0;
448 req
->in
.h
.opcode
= isdir
? FUSE_FSYNCDIR
: FUSE_FSYNC
;
449 req
->in
.h
.nodeid
= get_node_id(inode
);
451 req
->in
.args
[0].size
= sizeof(inarg
);
452 req
->in
.args
[0].value
= &inarg
;
453 fuse_request_send(fc
, req
);
454 err
= req
->out
.h
.error
;
455 fuse_put_request(fc
, req
);
456 if (err
== -ENOSYS
) {
464 mutex_unlock(&inode
->i_mutex
);
468 static int fuse_fsync(struct file
*file
, loff_t start
, loff_t end
,
471 return fuse_fsync_common(file
, start
, end
, datasync
, 0);
474 void fuse_read_fill(struct fuse_req
*req
, struct file
*file
, loff_t pos
,
475 size_t count
, int opcode
)
477 struct fuse_read_in
*inarg
= &req
->misc
.read
.in
;
478 struct fuse_file
*ff
= file
->private_data
;
483 inarg
->flags
= file
->f_flags
;
484 req
->in
.h
.opcode
= opcode
;
485 req
->in
.h
.nodeid
= ff
->nodeid
;
487 req
->in
.args
[0].size
= sizeof(struct fuse_read_in
);
488 req
->in
.args
[0].value
= inarg
;
490 req
->out
.numargs
= 1;
491 req
->out
.args
[0].size
= count
;
494 static size_t fuse_send_read(struct fuse_req
*req
, struct file
*file
,
495 loff_t pos
, size_t count
, fl_owner_t owner
)
497 struct fuse_file
*ff
= file
->private_data
;
498 struct fuse_conn
*fc
= ff
->fc
;
500 fuse_read_fill(req
, file
, pos
, count
, FUSE_READ
);
502 struct fuse_read_in
*inarg
= &req
->misc
.read
.in
;
504 inarg
->read_flags
|= FUSE_READ_LOCKOWNER
;
505 inarg
->lock_owner
= fuse_lock_owner_id(fc
, owner
);
507 fuse_request_send(fc
, req
);
508 return req
->out
.args
[0].size
;
511 static void fuse_read_update_size(struct inode
*inode
, loff_t size
,
514 struct fuse_conn
*fc
= get_fuse_conn(inode
);
515 struct fuse_inode
*fi
= get_fuse_inode(inode
);
517 spin_lock(&fc
->lock
);
518 if (attr_ver
== fi
->attr_version
&& size
< inode
->i_size
) {
519 fi
->attr_version
= ++fc
->attr_version
;
520 i_size_write(inode
, size
);
522 spin_unlock(&fc
->lock
);
525 static int fuse_readpage(struct file
*file
, struct page
*page
)
527 struct inode
*inode
= page
->mapping
->host
;
528 struct fuse_conn
*fc
= get_fuse_conn(inode
);
529 struct fuse_req
*req
;
531 loff_t pos
= page_offset(page
);
532 size_t count
= PAGE_CACHE_SIZE
;
537 if (is_bad_inode(inode
))
541 * Page writeback can extend beyond the lifetime of the
542 * page-cache page, so make sure we read a properly synced
545 fuse_wait_on_page_writeback(inode
, page
->index
);
547 req
= fuse_get_req(fc
, 1);
552 attr_ver
= fuse_get_attr_version(fc
);
554 req
->out
.page_zeroing
= 1;
555 req
->out
.argpages
= 1;
557 req
->pages
[0] = page
;
558 req
->page_descs
[0].length
= count
;
559 num_read
= fuse_send_read(req
, file
, pos
, count
, NULL
);
560 err
= req
->out
.h
.error
;
561 fuse_put_request(fc
, req
);
565 * Short read means EOF. If file size is larger, truncate it
567 if (num_read
< count
)
568 fuse_read_update_size(inode
, pos
+ num_read
, attr_ver
);
570 SetPageUptodate(page
);
573 fuse_invalidate_attr(inode
); /* atime changed */
579 static void fuse_readpages_end(struct fuse_conn
*fc
, struct fuse_req
*req
)
582 size_t count
= req
->misc
.read
.in
.size
;
583 size_t num_read
= req
->out
.args
[0].size
;
584 struct address_space
*mapping
= NULL
;
586 for (i
= 0; mapping
== NULL
&& i
< req
->num_pages
; i
++)
587 mapping
= req
->pages
[i
]->mapping
;
590 struct inode
*inode
= mapping
->host
;
593 * Short read means EOF. If file size is larger, truncate it
595 if (!req
->out
.h
.error
&& num_read
< count
) {
598 pos
= page_offset(req
->pages
[0]) + num_read
;
599 fuse_read_update_size(inode
, pos
,
600 req
->misc
.read
.attr_ver
);
602 fuse_invalidate_attr(inode
); /* atime changed */
605 for (i
= 0; i
< req
->num_pages
; i
++) {
606 struct page
*page
= req
->pages
[i
];
607 if (!req
->out
.h
.error
)
608 SetPageUptodate(page
);
612 page_cache_release(page
);
615 fuse_file_put(req
->ff
, false);
618 static void fuse_send_readpages(struct fuse_req
*req
, struct file
*file
)
620 struct fuse_file
*ff
= file
->private_data
;
621 struct fuse_conn
*fc
= ff
->fc
;
622 loff_t pos
= page_offset(req
->pages
[0]);
623 size_t count
= req
->num_pages
<< PAGE_CACHE_SHIFT
;
625 req
->out
.argpages
= 1;
626 req
->out
.page_zeroing
= 1;
627 req
->out
.page_replace
= 1;
628 fuse_read_fill(req
, file
, pos
, count
, FUSE_READ
);
629 req
->misc
.read
.attr_ver
= fuse_get_attr_version(fc
);
630 if (fc
->async_read
) {
631 req
->ff
= fuse_file_get(ff
);
632 req
->end
= fuse_readpages_end
;
633 fuse_request_send_background(fc
, req
);
635 fuse_request_send(fc
, req
);
636 fuse_readpages_end(fc
, req
);
637 fuse_put_request(fc
, req
);
641 struct fuse_fill_data
{
642 struct fuse_req
*req
;
648 static int fuse_readpages_fill(void *_data
, struct page
*page
)
650 struct fuse_fill_data
*data
= _data
;
651 struct fuse_req
*req
= data
->req
;
652 struct inode
*inode
= data
->inode
;
653 struct fuse_conn
*fc
= get_fuse_conn(inode
);
655 fuse_wait_on_page_writeback(inode
, page
->index
);
657 if (req
->num_pages
&&
658 (req
->num_pages
== FUSE_MAX_PAGES_PER_REQ
||
659 (req
->num_pages
+ 1) * PAGE_CACHE_SIZE
> fc
->max_read
||
660 req
->pages
[req
->num_pages
- 1]->index
+ 1 != page
->index
)) {
661 int nr_alloc
= min_t(unsigned, data
->nr_pages
,
662 FUSE_MAX_PAGES_PER_REQ
);
663 fuse_send_readpages(req
, data
->file
);
664 data
->req
= req
= fuse_get_req(fc
, nr_alloc
);
671 if (WARN_ON(req
->num_pages
>= req
->max_pages
)) {
672 fuse_put_request(fc
, req
);
676 page_cache_get(page
);
677 req
->pages
[req
->num_pages
] = page
;
678 req
->page_descs
[req
->num_pages
].length
= PAGE_SIZE
;
684 static int fuse_readpages(struct file
*file
, struct address_space
*mapping
,
685 struct list_head
*pages
, unsigned nr_pages
)
687 struct inode
*inode
= mapping
->host
;
688 struct fuse_conn
*fc
= get_fuse_conn(inode
);
689 struct fuse_fill_data data
;
691 int nr_alloc
= min_t(unsigned, nr_pages
, FUSE_MAX_PAGES_PER_REQ
);
694 if (is_bad_inode(inode
))
699 data
.req
= fuse_get_req(fc
, nr_alloc
);
700 data
.nr_pages
= nr_pages
;
701 err
= PTR_ERR(data
.req
);
702 if (IS_ERR(data
.req
))
705 err
= read_cache_pages(mapping
, pages
, fuse_readpages_fill
, &data
);
707 if (data
.req
->num_pages
)
708 fuse_send_readpages(data
.req
, file
);
710 fuse_put_request(fc
, data
.req
);
716 static ssize_t
fuse_file_aio_read(struct kiocb
*iocb
, const struct iovec
*iov
,
717 unsigned long nr_segs
, loff_t pos
)
719 struct inode
*inode
= iocb
->ki_filp
->f_mapping
->host
;
720 struct fuse_conn
*fc
= get_fuse_conn(inode
);
723 * In auto invalidate mode, always update attributes on read.
724 * Otherwise, only update if we attempt to read past EOF (to ensure
725 * i_size is up to date).
727 if (fc
->auto_inval_data
||
728 (pos
+ iov_length(iov
, nr_segs
) > i_size_read(inode
))) {
730 err
= fuse_update_attributes(inode
, NULL
, iocb
->ki_filp
, NULL
);
735 return generic_file_aio_read(iocb
, iov
, nr_segs
, pos
);
738 static void fuse_write_fill(struct fuse_req
*req
, struct fuse_file
*ff
,
739 loff_t pos
, size_t count
)
741 struct fuse_write_in
*inarg
= &req
->misc
.write
.in
;
742 struct fuse_write_out
*outarg
= &req
->misc
.write
.out
;
747 req
->in
.h
.opcode
= FUSE_WRITE
;
748 req
->in
.h
.nodeid
= ff
->nodeid
;
750 if (ff
->fc
->minor
< 9)
751 req
->in
.args
[0].size
= FUSE_COMPAT_WRITE_IN_SIZE
;
753 req
->in
.args
[0].size
= sizeof(struct fuse_write_in
);
754 req
->in
.args
[0].value
= inarg
;
755 req
->in
.args
[1].size
= count
;
756 req
->out
.numargs
= 1;
757 req
->out
.args
[0].size
= sizeof(struct fuse_write_out
);
758 req
->out
.args
[0].value
= outarg
;
761 static size_t fuse_send_write(struct fuse_req
*req
, struct file
*file
,
762 loff_t pos
, size_t count
, fl_owner_t owner
)
764 struct fuse_file
*ff
= file
->private_data
;
765 struct fuse_conn
*fc
= ff
->fc
;
766 struct fuse_write_in
*inarg
= &req
->misc
.write
.in
;
768 fuse_write_fill(req
, ff
, pos
, count
);
769 inarg
->flags
= file
->f_flags
;
771 inarg
->write_flags
|= FUSE_WRITE_LOCKOWNER
;
772 inarg
->lock_owner
= fuse_lock_owner_id(fc
, owner
);
774 fuse_request_send(fc
, req
);
775 return req
->misc
.write
.out
.size
;
778 void fuse_write_update_size(struct inode
*inode
, loff_t pos
)
780 struct fuse_conn
*fc
= get_fuse_conn(inode
);
781 struct fuse_inode
*fi
= get_fuse_inode(inode
);
783 spin_lock(&fc
->lock
);
784 fi
->attr_version
= ++fc
->attr_version
;
785 if (pos
> inode
->i_size
)
786 i_size_write(inode
, pos
);
787 spin_unlock(&fc
->lock
);
790 static size_t fuse_send_write_pages(struct fuse_req
*req
, struct file
*file
,
791 struct inode
*inode
, loff_t pos
,
798 for (i
= 0; i
< req
->num_pages
; i
++)
799 fuse_wait_on_page_writeback(inode
, req
->pages
[i
]->index
);
801 res
= fuse_send_write(req
, file
, pos
, count
, NULL
);
803 offset
= req
->page_descs
[0].offset
;
805 for (i
= 0; i
< req
->num_pages
; i
++) {
806 struct page
*page
= req
->pages
[i
];
808 if (!req
->out
.h
.error
&& !offset
&& count
>= PAGE_CACHE_SIZE
)
809 SetPageUptodate(page
);
811 if (count
> PAGE_CACHE_SIZE
- offset
)
812 count
-= PAGE_CACHE_SIZE
- offset
;
818 page_cache_release(page
);
824 static ssize_t
fuse_fill_write_pages(struct fuse_req
*req
,
825 struct address_space
*mapping
,
826 struct iov_iter
*ii
, loff_t pos
)
828 struct fuse_conn
*fc
= get_fuse_conn(mapping
->host
);
829 unsigned offset
= pos
& (PAGE_CACHE_SIZE
- 1);
833 req
->in
.argpages
= 1;
834 req
->page_descs
[0].offset
= offset
;
839 pgoff_t index
= pos
>> PAGE_CACHE_SHIFT
;
840 size_t bytes
= min_t(size_t, PAGE_CACHE_SIZE
- offset
,
843 bytes
= min_t(size_t, bytes
, fc
->max_write
- count
);
847 if (iov_iter_fault_in_readable(ii
, bytes
))
851 page
= grab_cache_page_write_begin(mapping
, index
, 0);
855 if (mapping_writably_mapped(mapping
))
856 flush_dcache_page(page
);
859 tmp
= iov_iter_copy_from_user_atomic(page
, ii
, offset
, bytes
);
861 flush_dcache_page(page
);
863 mark_page_accessed(page
);
867 page_cache_release(page
);
868 bytes
= min(bytes
, iov_iter_single_seg_count(ii
));
873 req
->pages
[req
->num_pages
] = page
;
874 req
->page_descs
[req
->num_pages
].length
= tmp
;
877 iov_iter_advance(ii
, tmp
);
881 if (offset
== PAGE_CACHE_SIZE
)
886 } while (iov_iter_count(ii
) && count
< fc
->max_write
&&
887 req
->num_pages
< req
->max_pages
&& offset
== 0);
889 return count
> 0 ? count
: err
;
892 static inline unsigned fuse_wr_pages(loff_t pos
, size_t len
)
894 return min_t(unsigned,
895 ((pos
+ len
- 1) >> PAGE_CACHE_SHIFT
) -
896 (pos
>> PAGE_CACHE_SHIFT
) + 1,
897 FUSE_MAX_PAGES_PER_REQ
);
900 static ssize_t
fuse_perform_write(struct file
*file
,
901 struct address_space
*mapping
,
902 struct iov_iter
*ii
, loff_t pos
)
904 struct inode
*inode
= mapping
->host
;
905 struct fuse_conn
*fc
= get_fuse_conn(inode
);
909 if (is_bad_inode(inode
))
913 struct fuse_req
*req
;
915 unsigned nr_pages
= fuse_wr_pages(pos
, iov_iter_count(ii
));
917 req
= fuse_get_req(fc
, nr_pages
);
923 count
= fuse_fill_write_pages(req
, mapping
, ii
, pos
);
929 num_written
= fuse_send_write_pages(req
, file
, inode
,
931 err
= req
->out
.h
.error
;
936 /* break out of the loop on short write */
937 if (num_written
!= count
)
941 fuse_put_request(fc
, req
);
942 } while (!err
&& iov_iter_count(ii
));
945 fuse_write_update_size(inode
, pos
);
947 fuse_invalidate_attr(inode
);
949 return res
> 0 ? res
: err
;
952 static ssize_t
fuse_file_aio_write(struct kiocb
*iocb
, const struct iovec
*iov
,
953 unsigned long nr_segs
, loff_t pos
)
955 struct file
*file
= iocb
->ki_filp
;
956 struct address_space
*mapping
= file
->f_mapping
;
960 ssize_t written_buffered
= 0;
961 struct inode
*inode
= mapping
->host
;
966 WARN_ON(iocb
->ki_pos
!= pos
);
969 err
= generic_segment_checks(iov
, &nr_segs
, &ocount
, VERIFY_READ
);
974 mutex_lock(&inode
->i_mutex
);
976 /* We can write back this queue in page reclaim */
977 current
->backing_dev_info
= mapping
->backing_dev_info
;
979 err
= generic_write_checks(file
, &pos
, &count
, S_ISBLK(inode
->i_mode
));
986 err
= file_remove_suid(file
);
990 err
= file_update_time(file
);
994 if (file
->f_flags
& O_DIRECT
) {
995 written
= generic_file_direct_write(iocb
, iov
, &nr_segs
,
998 if (written
< 0 || written
== count
)
1004 iov_iter_init(&i
, iov
, nr_segs
, count
, written
);
1005 written_buffered
= fuse_perform_write(file
, mapping
, &i
, pos
);
1006 if (written_buffered
< 0) {
1007 err
= written_buffered
;
1010 endbyte
= pos
+ written_buffered
- 1;
1012 err
= filemap_write_and_wait_range(file
->f_mapping
, pos
,
1017 invalidate_mapping_pages(file
->f_mapping
,
1018 pos
>> PAGE_CACHE_SHIFT
,
1019 endbyte
>> PAGE_CACHE_SHIFT
);
1021 written
+= written_buffered
;
1022 iocb
->ki_pos
= pos
+ written_buffered
;
1024 iov_iter_init(&i
, iov
, nr_segs
, count
, 0);
1025 written
= fuse_perform_write(file
, mapping
, &i
, pos
);
1027 iocb
->ki_pos
= pos
+ written
;
1030 current
->backing_dev_info
= NULL
;
1031 mutex_unlock(&inode
->i_mutex
);
1033 return written
? written
: err
;
1036 static void fuse_release_user_pages(struct fuse_req
*req
, int write
)
1040 for (i
= 0; i
< req
->num_pages
; i
++) {
1041 struct page
*page
= req
->pages
[i
];
1043 set_page_dirty_lock(page
);
1048 static inline void fuse_page_descs_length_init(struct fuse_req
*req
,
1049 unsigned index
, unsigned nr_pages
)
1053 for (i
= index
; i
< index
+ nr_pages
; i
++)
1054 req
->page_descs
[i
].length
= PAGE_SIZE
-
1055 req
->page_descs
[i
].offset
;
1058 static inline unsigned long fuse_get_user_addr(const struct iov_iter
*ii
)
1060 return (unsigned long)ii
->iov
->iov_base
+ ii
->iov_offset
;
1063 static inline size_t fuse_get_frag_size(const struct iov_iter
*ii
,
1066 return min(iov_iter_single_seg_count(ii
), max_size
);
1069 static int fuse_get_user_pages(struct fuse_req
*req
, struct iov_iter
*ii
,
1070 size_t *nbytesp
, int write
)
1072 size_t nbytes
= 0; /* # bytes already packed in req */
1074 /* Special case for kernel I/O: can copy directly into the buffer */
1075 if (segment_eq(get_fs(), KERNEL_DS
)) {
1076 unsigned long user_addr
= fuse_get_user_addr(ii
);
1077 size_t frag_size
= fuse_get_frag_size(ii
, *nbytesp
);
1080 req
->in
.args
[1].value
= (void *) user_addr
;
1082 req
->out
.args
[0].value
= (void *) user_addr
;
1084 iov_iter_advance(ii
, frag_size
);
1085 *nbytesp
= frag_size
;
1089 while (nbytes
< *nbytesp
&& req
->num_pages
< req
->max_pages
) {
1091 unsigned long user_addr
= fuse_get_user_addr(ii
);
1092 unsigned offset
= user_addr
& ~PAGE_MASK
;
1093 size_t frag_size
= fuse_get_frag_size(ii
, *nbytesp
- nbytes
);
1096 unsigned n
= req
->max_pages
- req
->num_pages
;
1097 frag_size
= min_t(size_t, frag_size
, n
<< PAGE_SHIFT
);
1099 npages
= (frag_size
+ offset
+ PAGE_SIZE
- 1) >> PAGE_SHIFT
;
1100 npages
= clamp(npages
, 1U, n
);
1102 ret
= get_user_pages_fast(user_addr
, npages
, !write
,
1103 &req
->pages
[req
->num_pages
]);
1108 frag_size
= min_t(size_t, frag_size
,
1109 (npages
<< PAGE_SHIFT
) - offset
);
1110 iov_iter_advance(ii
, frag_size
);
1112 req
->page_descs
[req
->num_pages
].offset
= offset
;
1113 fuse_page_descs_length_init(req
, req
->num_pages
, npages
);
1115 req
->num_pages
+= npages
;
1116 req
->page_descs
[req
->num_pages
- 1].length
-=
1117 (npages
<< PAGE_SHIFT
) - offset
- frag_size
;
1119 nbytes
+= frag_size
;
1123 req
->in
.argpages
= 1;
1125 req
->out
.argpages
= 1;
1132 static inline int fuse_iter_npages(const struct iov_iter
*ii_p
)
1134 struct iov_iter ii
= *ii_p
;
1137 while (iov_iter_count(&ii
) && npages
< FUSE_MAX_PAGES_PER_REQ
) {
1138 unsigned long user_addr
= fuse_get_user_addr(&ii
);
1139 unsigned offset
= user_addr
& ~PAGE_MASK
;
1140 size_t frag_size
= iov_iter_single_seg_count(&ii
);
1142 npages
+= (frag_size
+ offset
+ PAGE_SIZE
- 1) >> PAGE_SHIFT
;
1143 iov_iter_advance(&ii
, frag_size
);
1146 return min(npages
, FUSE_MAX_PAGES_PER_REQ
);
1149 ssize_t
fuse_direct_io(struct file
*file
, const struct iovec
*iov
,
1150 unsigned long nr_segs
, size_t count
, loff_t
*ppos
,
1153 struct fuse_file
*ff
= file
->private_data
;
1154 struct fuse_conn
*fc
= ff
->fc
;
1155 size_t nmax
= write
? fc
->max_write
: fc
->max_read
;
1158 struct fuse_req
*req
;
1161 iov_iter_init(&ii
, iov
, nr_segs
, count
, 0);
1163 req
= fuse_get_req(fc
, fuse_iter_npages(&ii
));
1165 return PTR_ERR(req
);
1169 fl_owner_t owner
= current
->files
;
1170 size_t nbytes
= min(count
, nmax
);
1171 int err
= fuse_get_user_pages(req
, &ii
, &nbytes
, write
);
1178 nres
= fuse_send_write(req
, file
, pos
, nbytes
, owner
);
1180 nres
= fuse_send_read(req
, file
, pos
, nbytes
, owner
);
1182 fuse_release_user_pages(req
, !write
);
1183 if (req
->out
.h
.error
) {
1185 res
= req
->out
.h
.error
;
1187 } else if (nres
> nbytes
) {
1197 fuse_put_request(fc
, req
);
1198 req
= fuse_get_req(fc
, fuse_iter_npages(&ii
));
1204 fuse_put_request(fc
, req
);
1210 EXPORT_SYMBOL_GPL(fuse_direct_io
);
1212 static ssize_t
__fuse_direct_read(struct file
*file
, const struct iovec
*iov
,
1213 unsigned long nr_segs
, loff_t
*ppos
)
1216 struct inode
*inode
= file_inode(file
);
1218 if (is_bad_inode(inode
))
1221 res
= fuse_direct_io(file
, iov
, nr_segs
, iov_length(iov
, nr_segs
),
1224 fuse_invalidate_attr(inode
);
1229 static ssize_t
fuse_direct_read(struct file
*file
, char __user
*buf
,
1230 size_t count
, loff_t
*ppos
)
1232 struct iovec iov
= { .iov_base
= buf
, .iov_len
= count
};
1233 return __fuse_direct_read(file
, &iov
, 1, ppos
);
1236 static ssize_t
__fuse_direct_write(struct file
*file
, const struct iovec
*iov
,
1237 unsigned long nr_segs
, loff_t
*ppos
)
1239 struct inode
*inode
= file_inode(file
);
1240 size_t count
= iov_length(iov
, nr_segs
);
1243 res
= generic_write_checks(file
, ppos
, &count
, 0);
1245 res
= fuse_direct_io(file
, iov
, nr_segs
, count
, ppos
, 1);
1247 fuse_write_update_size(inode
, *ppos
);
1250 fuse_invalidate_attr(inode
);
1255 static ssize_t
fuse_direct_write(struct file
*file
, const char __user
*buf
,
1256 size_t count
, loff_t
*ppos
)
1258 struct iovec iov
= { .iov_base
= (void __user
*)buf
, .iov_len
= count
};
1259 struct inode
*inode
= file_inode(file
);
1262 if (is_bad_inode(inode
))
1265 /* Don't allow parallel writes to the same file */
1266 mutex_lock(&inode
->i_mutex
);
1267 res
= __fuse_direct_write(file
, &iov
, 1, ppos
);
1268 mutex_unlock(&inode
->i_mutex
);
1273 static void fuse_writepage_free(struct fuse_conn
*fc
, struct fuse_req
*req
)
1275 __free_page(req
->pages
[0]);
1276 fuse_file_put(req
->ff
, false);
1279 static void fuse_writepage_finish(struct fuse_conn
*fc
, struct fuse_req
*req
)
1281 struct inode
*inode
= req
->inode
;
1282 struct fuse_inode
*fi
= get_fuse_inode(inode
);
1283 struct backing_dev_info
*bdi
= inode
->i_mapping
->backing_dev_info
;
1285 list_del(&req
->writepages_entry
);
1286 dec_bdi_stat(bdi
, BDI_WRITEBACK
);
1287 dec_zone_page_state(req
->pages
[0], NR_WRITEBACK_TEMP
);
1288 bdi_writeout_inc(bdi
);
1289 wake_up(&fi
->page_waitq
);
1292 /* Called under fc->lock, may release and reacquire it */
1293 static void fuse_send_writepage(struct fuse_conn
*fc
, struct fuse_req
*req
)
1294 __releases(fc
->lock
)
1295 __acquires(fc
->lock
)
1297 struct fuse_inode
*fi
= get_fuse_inode(req
->inode
);
1298 loff_t size
= i_size_read(req
->inode
);
1299 struct fuse_write_in
*inarg
= &req
->misc
.write
.in
;
1304 if (inarg
->offset
+ PAGE_CACHE_SIZE
<= size
) {
1305 inarg
->size
= PAGE_CACHE_SIZE
;
1306 } else if (inarg
->offset
< size
) {
1307 inarg
->size
= size
& (PAGE_CACHE_SIZE
- 1);
1309 /* Got truncated off completely */
1313 req
->in
.args
[1].size
= inarg
->size
;
1315 fuse_request_send_background_locked(fc
, req
);
1319 fuse_writepage_finish(fc
, req
);
1320 spin_unlock(&fc
->lock
);
1321 fuse_writepage_free(fc
, req
);
1322 fuse_put_request(fc
, req
);
1323 spin_lock(&fc
->lock
);
1327 * If fi->writectr is positive (no truncate or fsync going on) send
1328 * all queued writepage requests.
1330 * Called with fc->lock
1332 void fuse_flush_writepages(struct inode
*inode
)
1333 __releases(fc
->lock
)
1334 __acquires(fc
->lock
)
1336 struct fuse_conn
*fc
= get_fuse_conn(inode
);
1337 struct fuse_inode
*fi
= get_fuse_inode(inode
);
1338 struct fuse_req
*req
;
1340 while (fi
->writectr
>= 0 && !list_empty(&fi
->queued_writes
)) {
1341 req
= list_entry(fi
->queued_writes
.next
, struct fuse_req
, list
);
1342 list_del_init(&req
->list
);
1343 fuse_send_writepage(fc
, req
);
1347 static void fuse_writepage_end(struct fuse_conn
*fc
, struct fuse_req
*req
)
1349 struct inode
*inode
= req
->inode
;
1350 struct fuse_inode
*fi
= get_fuse_inode(inode
);
1352 mapping_set_error(inode
->i_mapping
, req
->out
.h
.error
);
1353 spin_lock(&fc
->lock
);
1355 fuse_writepage_finish(fc
, req
);
1356 spin_unlock(&fc
->lock
);
1357 fuse_writepage_free(fc
, req
);
1360 static int fuse_writepage_locked(struct page
*page
)
1362 struct address_space
*mapping
= page
->mapping
;
1363 struct inode
*inode
= mapping
->host
;
1364 struct fuse_conn
*fc
= get_fuse_conn(inode
);
1365 struct fuse_inode
*fi
= get_fuse_inode(inode
);
1366 struct fuse_req
*req
;
1367 struct fuse_file
*ff
;
1368 struct page
*tmp_page
;
1370 set_page_writeback(page
);
1372 req
= fuse_request_alloc_nofs(1);
1376 tmp_page
= alloc_page(GFP_NOFS
| __GFP_HIGHMEM
);
1380 spin_lock(&fc
->lock
);
1381 BUG_ON(list_empty(&fi
->write_files
));
1382 ff
= list_entry(fi
->write_files
.next
, struct fuse_file
, write_entry
);
1383 req
->ff
= fuse_file_get(ff
);
1384 spin_unlock(&fc
->lock
);
1386 fuse_write_fill(req
, ff
, page_offset(page
), 0);
1388 copy_highpage(tmp_page
, page
);
1389 req
->misc
.write
.in
.write_flags
|= FUSE_WRITE_CACHE
;
1390 req
->in
.argpages
= 1;
1392 req
->pages
[0] = tmp_page
;
1393 req
->page_descs
[0].offset
= 0;
1394 req
->page_descs
[0].length
= PAGE_SIZE
;
1395 req
->end
= fuse_writepage_end
;
1398 inc_bdi_stat(mapping
->backing_dev_info
, BDI_WRITEBACK
);
1399 inc_zone_page_state(tmp_page
, NR_WRITEBACK_TEMP
);
1400 end_page_writeback(page
);
1402 spin_lock(&fc
->lock
);
1403 list_add(&req
->writepages_entry
, &fi
->writepages
);
1404 list_add_tail(&req
->list
, &fi
->queued_writes
);
1405 fuse_flush_writepages(inode
);
1406 spin_unlock(&fc
->lock
);
1411 fuse_request_free(req
);
1413 end_page_writeback(page
);
1417 static int fuse_writepage(struct page
*page
, struct writeback_control
*wbc
)
1421 err
= fuse_writepage_locked(page
);
1427 static int fuse_launder_page(struct page
*page
)
1430 if (clear_page_dirty_for_io(page
)) {
1431 struct inode
*inode
= page
->mapping
->host
;
1432 err
= fuse_writepage_locked(page
);
1434 fuse_wait_on_page_writeback(inode
, page
->index
);
1440 * Write back dirty pages now, because there may not be any suitable
1443 static void fuse_vma_close(struct vm_area_struct
*vma
)
1445 filemap_write_and_wait(vma
->vm_file
->f_mapping
);
1449 * Wait for writeback against this page to complete before allowing it
1450 * to be marked dirty again, and hence written back again, possibly
1451 * before the previous writepage completed.
1453 * Block here, instead of in ->writepage(), so that the userspace fs
1454 * can only block processes actually operating on the filesystem.
1456 * Otherwise unprivileged userspace fs would be able to block
1461 * - try_to_free_pages() with order > PAGE_ALLOC_COSTLY_ORDER
1463 static int fuse_page_mkwrite(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
1465 struct page
*page
= vmf
->page
;
1467 * Don't use page->mapping as it may become NULL from a
1468 * concurrent truncate.
1470 struct inode
*inode
= vma
->vm_file
->f_mapping
->host
;
1472 fuse_wait_on_page_writeback(inode
, page
->index
);
1476 static const struct vm_operations_struct fuse_file_vm_ops
= {
1477 .close
= fuse_vma_close
,
1478 .fault
= filemap_fault
,
1479 .page_mkwrite
= fuse_page_mkwrite
,
1480 .remap_pages
= generic_file_remap_pages
,
1483 static int fuse_file_mmap(struct file
*file
, struct vm_area_struct
*vma
)
1485 if ((vma
->vm_flags
& VM_SHARED
) && (vma
->vm_flags
& VM_MAYWRITE
)) {
1486 struct inode
*inode
= file_inode(file
);
1487 struct fuse_conn
*fc
= get_fuse_conn(inode
);
1488 struct fuse_inode
*fi
= get_fuse_inode(inode
);
1489 struct fuse_file
*ff
= file
->private_data
;
1491 * file may be written through mmap, so chain it onto the
1492 * inodes's write_file list
1494 spin_lock(&fc
->lock
);
1495 if (list_empty(&ff
->write_entry
))
1496 list_add(&ff
->write_entry
, &fi
->write_files
);
1497 spin_unlock(&fc
->lock
);
1499 file_accessed(file
);
1500 vma
->vm_ops
= &fuse_file_vm_ops
;
1504 static int fuse_direct_mmap(struct file
*file
, struct vm_area_struct
*vma
)
1506 /* Can't provide the coherency needed for MAP_SHARED */
1507 if (vma
->vm_flags
& VM_MAYSHARE
)
1510 invalidate_inode_pages2(file
->f_mapping
);
1512 return generic_file_mmap(file
, vma
);
1515 static int convert_fuse_file_lock(const struct fuse_file_lock
*ffl
,
1516 struct file_lock
*fl
)
1518 switch (ffl
->type
) {
1524 if (ffl
->start
> OFFSET_MAX
|| ffl
->end
> OFFSET_MAX
||
1525 ffl
->end
< ffl
->start
)
1528 fl
->fl_start
= ffl
->start
;
1529 fl
->fl_end
= ffl
->end
;
1530 fl
->fl_pid
= ffl
->pid
;
1536 fl
->fl_type
= ffl
->type
;
1540 static void fuse_lk_fill(struct fuse_req
*req
, struct file
*file
,
1541 const struct file_lock
*fl
, int opcode
, pid_t pid
,
1544 struct inode
*inode
= file_inode(file
);
1545 struct fuse_conn
*fc
= get_fuse_conn(inode
);
1546 struct fuse_file
*ff
= file
->private_data
;
1547 struct fuse_lk_in
*arg
= &req
->misc
.lk_in
;
1550 arg
->owner
= fuse_lock_owner_id(fc
, fl
->fl_owner
);
1551 arg
->lk
.start
= fl
->fl_start
;
1552 arg
->lk
.end
= fl
->fl_end
;
1553 arg
->lk
.type
= fl
->fl_type
;
1556 arg
->lk_flags
|= FUSE_LK_FLOCK
;
1557 req
->in
.h
.opcode
= opcode
;
1558 req
->in
.h
.nodeid
= get_node_id(inode
);
1559 req
->in
.numargs
= 1;
1560 req
->in
.args
[0].size
= sizeof(*arg
);
1561 req
->in
.args
[0].value
= arg
;
1564 static int fuse_getlk(struct file
*file
, struct file_lock
*fl
)
1566 struct inode
*inode
= file_inode(file
);
1567 struct fuse_conn
*fc
= get_fuse_conn(inode
);
1568 struct fuse_req
*req
;
1569 struct fuse_lk_out outarg
;
1572 req
= fuse_get_req_nopages(fc
);
1574 return PTR_ERR(req
);
1576 fuse_lk_fill(req
, file
, fl
, FUSE_GETLK
, 0, 0);
1577 req
->out
.numargs
= 1;
1578 req
->out
.args
[0].size
= sizeof(outarg
);
1579 req
->out
.args
[0].value
= &outarg
;
1580 fuse_request_send(fc
, req
);
1581 err
= req
->out
.h
.error
;
1582 fuse_put_request(fc
, req
);
1584 err
= convert_fuse_file_lock(&outarg
.lk
, fl
);
1589 static int fuse_setlk(struct file
*file
, struct file_lock
*fl
, int flock
)
1591 struct inode
*inode
= file_inode(file
);
1592 struct fuse_conn
*fc
= get_fuse_conn(inode
);
1593 struct fuse_req
*req
;
1594 int opcode
= (fl
->fl_flags
& FL_SLEEP
) ? FUSE_SETLKW
: FUSE_SETLK
;
1595 pid_t pid
= fl
->fl_type
!= F_UNLCK
? current
->tgid
: 0;
1598 if (fl
->fl_lmops
&& fl
->fl_lmops
->lm_grant
) {
1599 /* NLM needs asynchronous locks, which we don't support yet */
1603 /* Unlock on close is handled by the flush method */
1604 if (fl
->fl_flags
& FL_CLOSE
)
1607 req
= fuse_get_req_nopages(fc
);
1609 return PTR_ERR(req
);
1611 fuse_lk_fill(req
, file
, fl
, opcode
, pid
, flock
);
1612 fuse_request_send(fc
, req
);
1613 err
= req
->out
.h
.error
;
1614 /* locking is restartable */
1617 fuse_put_request(fc
, req
);
1621 static int fuse_file_lock(struct file
*file
, int cmd
, struct file_lock
*fl
)
1623 struct inode
*inode
= file_inode(file
);
1624 struct fuse_conn
*fc
= get_fuse_conn(inode
);
1627 if (cmd
== F_CANCELLK
) {
1629 } else if (cmd
== F_GETLK
) {
1631 posix_test_lock(file
, fl
);
1634 err
= fuse_getlk(file
, fl
);
1637 err
= posix_lock_file(file
, fl
, NULL
);
1639 err
= fuse_setlk(file
, fl
, 0);
1644 static int fuse_file_flock(struct file
*file
, int cmd
, struct file_lock
*fl
)
1646 struct inode
*inode
= file_inode(file
);
1647 struct fuse_conn
*fc
= get_fuse_conn(inode
);
1651 err
= flock_lock_file_wait(file
, fl
);
1653 struct fuse_file
*ff
= file
->private_data
;
1655 /* emulate flock with POSIX locks */
1656 fl
->fl_owner
= (fl_owner_t
) file
;
1658 err
= fuse_setlk(file
, fl
, 1);
1664 static sector_t
fuse_bmap(struct address_space
*mapping
, sector_t block
)
1666 struct inode
*inode
= mapping
->host
;
1667 struct fuse_conn
*fc
= get_fuse_conn(inode
);
1668 struct fuse_req
*req
;
1669 struct fuse_bmap_in inarg
;
1670 struct fuse_bmap_out outarg
;
1673 if (!inode
->i_sb
->s_bdev
|| fc
->no_bmap
)
1676 req
= fuse_get_req_nopages(fc
);
1680 memset(&inarg
, 0, sizeof(inarg
));
1681 inarg
.block
= block
;
1682 inarg
.blocksize
= inode
->i_sb
->s_blocksize
;
1683 req
->in
.h
.opcode
= FUSE_BMAP
;
1684 req
->in
.h
.nodeid
= get_node_id(inode
);
1685 req
->in
.numargs
= 1;
1686 req
->in
.args
[0].size
= sizeof(inarg
);
1687 req
->in
.args
[0].value
= &inarg
;
1688 req
->out
.numargs
= 1;
1689 req
->out
.args
[0].size
= sizeof(outarg
);
1690 req
->out
.args
[0].value
= &outarg
;
1691 fuse_request_send(fc
, req
);
1692 err
= req
->out
.h
.error
;
1693 fuse_put_request(fc
, req
);
1697 return err
? 0 : outarg
.block
;
1700 static loff_t
fuse_file_llseek(struct file
*file
, loff_t offset
, int whence
)
1703 struct inode
*inode
= file_inode(file
);
1705 /* No i_mutex protection necessary for SEEK_CUR and SEEK_SET */
1706 if (whence
== SEEK_CUR
|| whence
== SEEK_SET
)
1707 return generic_file_llseek(file
, offset
, whence
);
1709 mutex_lock(&inode
->i_mutex
);
1710 retval
= fuse_update_attributes(inode
, NULL
, file
, NULL
);
1712 retval
= generic_file_llseek(file
, offset
, whence
);
1713 mutex_unlock(&inode
->i_mutex
);
1718 static int fuse_ioctl_copy_user(struct page
**pages
, struct iovec
*iov
,
1719 unsigned int nr_segs
, size_t bytes
, bool to_user
)
1727 iov_iter_init(&ii
, iov
, nr_segs
, bytes
, 0);
1729 while (iov_iter_count(&ii
)) {
1730 struct page
*page
= pages
[page_idx
++];
1731 size_t todo
= min_t(size_t, PAGE_SIZE
, iov_iter_count(&ii
));
1737 char __user
*uaddr
= ii
.iov
->iov_base
+ ii
.iov_offset
;
1738 size_t iov_len
= ii
.iov
->iov_len
- ii
.iov_offset
;
1739 size_t copy
= min(todo
, iov_len
);
1743 left
= copy_from_user(kaddr
, uaddr
, copy
);
1745 left
= copy_to_user(uaddr
, kaddr
, copy
);
1750 iov_iter_advance(&ii
, copy
);
1762 * CUSE servers compiled on 32bit broke on 64bit kernels because the
1763 * ABI was defined to be 'struct iovec' which is different on 32bit
1764 * and 64bit. Fortunately we can determine which structure the server
1765 * used from the size of the reply.
1767 static int fuse_copy_ioctl_iovec_old(struct iovec
*dst
, void *src
,
1768 size_t transferred
, unsigned count
,
1771 #ifdef CONFIG_COMPAT
1772 if (count
* sizeof(struct compat_iovec
) == transferred
) {
1773 struct compat_iovec
*ciov
= src
;
1777 * With this interface a 32bit server cannot support
1778 * non-compat (i.e. ones coming from 64bit apps) ioctl
1784 for (i
= 0; i
< count
; i
++) {
1785 dst
[i
].iov_base
= compat_ptr(ciov
[i
].iov_base
);
1786 dst
[i
].iov_len
= ciov
[i
].iov_len
;
1792 if (count
* sizeof(struct iovec
) != transferred
)
1795 memcpy(dst
, src
, transferred
);
1799 /* Make sure iov_length() won't overflow */
1800 static int fuse_verify_ioctl_iov(struct iovec
*iov
, size_t count
)
1803 u32 max
= FUSE_MAX_PAGES_PER_REQ
<< PAGE_SHIFT
;
1805 for (n
= 0; n
< count
; n
++, iov
++) {
1806 if (iov
->iov_len
> (size_t) max
)
1808 max
-= iov
->iov_len
;
1813 static int fuse_copy_ioctl_iovec(struct fuse_conn
*fc
, struct iovec
*dst
,
1814 void *src
, size_t transferred
, unsigned count
,
1818 struct fuse_ioctl_iovec
*fiov
= src
;
1820 if (fc
->minor
< 16) {
1821 return fuse_copy_ioctl_iovec_old(dst
, src
, transferred
,
1825 if (count
* sizeof(struct fuse_ioctl_iovec
) != transferred
)
1828 for (i
= 0; i
< count
; i
++) {
1829 /* Did the server supply an inappropriate value? */
1830 if (fiov
[i
].base
!= (unsigned long) fiov
[i
].base
||
1831 fiov
[i
].len
!= (unsigned long) fiov
[i
].len
)
1834 dst
[i
].iov_base
= (void __user
*) (unsigned long) fiov
[i
].base
;
1835 dst
[i
].iov_len
= (size_t) fiov
[i
].len
;
1837 #ifdef CONFIG_COMPAT
1839 (ptr_to_compat(dst
[i
].iov_base
) != fiov
[i
].base
||
1840 (compat_size_t
) dst
[i
].iov_len
!= fiov
[i
].len
))
1850 * For ioctls, there is no generic way to determine how much memory
1851 * needs to be read and/or written. Furthermore, ioctls are allowed
1852 * to dereference the passed pointer, so the parameter requires deep
1853 * copying but FUSE has no idea whatsoever about what to copy in or
1856 * This is solved by allowing FUSE server to retry ioctl with
1857 * necessary in/out iovecs. Let's assume the ioctl implementation
1858 * needs to read in the following structure.
1865 * On the first callout to FUSE server, inarg->in_size and
1866 * inarg->out_size will be NULL; then, the server completes the ioctl
1867 * with FUSE_IOCTL_RETRY set in out->flags, out->in_iovs set to 1 and
1868 * the actual iov array to
1870 * { { .iov_base = inarg.arg, .iov_len = sizeof(struct a) } }
1872 * which tells FUSE to copy in the requested area and retry the ioctl.
1873 * On the second round, the server has access to the structure and
1874 * from that it can tell what to look for next, so on the invocation,
1875 * it sets FUSE_IOCTL_RETRY, out->in_iovs to 2 and iov array to
1877 * { { .iov_base = inarg.arg, .iov_len = sizeof(struct a) },
1878 * { .iov_base = a.buf, .iov_len = a.buflen } }
1880 * FUSE will copy both struct a and the pointed buffer from the
1881 * process doing the ioctl and retry ioctl with both struct a and the
1884 * This time, FUSE server has everything it needs and completes ioctl
1885 * without FUSE_IOCTL_RETRY which finishes the ioctl call.
1887 * Copying data out works the same way.
1889 * Note that if FUSE_IOCTL_UNRESTRICTED is clear, the kernel
1890 * automatically initializes in and out iovs by decoding @cmd with
1891 * _IOC_* macros and the server is not allowed to request RETRY. This
1892 * limits ioctl data transfers to well-formed ioctls and is the forced
1893 * behavior for all FUSE servers.
1895 long fuse_do_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
,
1898 struct fuse_file
*ff
= file
->private_data
;
1899 struct fuse_conn
*fc
= ff
->fc
;
1900 struct fuse_ioctl_in inarg
= {
1906 struct fuse_ioctl_out outarg
;
1907 struct fuse_req
*req
= NULL
;
1908 struct page
**pages
= NULL
;
1909 struct iovec
*iov_page
= NULL
;
1910 struct iovec
*in_iov
= NULL
, *out_iov
= NULL
;
1911 unsigned int in_iovs
= 0, out_iovs
= 0, num_pages
= 0, max_pages
;
1912 size_t in_size
, out_size
, transferred
;
1915 #if BITS_PER_LONG == 32
1916 inarg
.flags
|= FUSE_IOCTL_32BIT
;
1918 if (flags
& FUSE_IOCTL_COMPAT
)
1919 inarg
.flags
|= FUSE_IOCTL_32BIT
;
1922 /* assume all the iovs returned by client always fits in a page */
1923 BUILD_BUG_ON(sizeof(struct fuse_ioctl_iovec
) * FUSE_IOCTL_MAX_IOV
> PAGE_SIZE
);
1926 pages
= kcalloc(FUSE_MAX_PAGES_PER_REQ
, sizeof(pages
[0]), GFP_KERNEL
);
1927 iov_page
= (struct iovec
*) __get_free_page(GFP_KERNEL
);
1928 if (!pages
|| !iov_page
)
1932 * If restricted, initialize IO parameters as encoded in @cmd.
1933 * RETRY from server is not allowed.
1935 if (!(flags
& FUSE_IOCTL_UNRESTRICTED
)) {
1936 struct iovec
*iov
= iov_page
;
1938 iov
->iov_base
= (void __user
*)arg
;
1939 iov
->iov_len
= _IOC_SIZE(cmd
);
1941 if (_IOC_DIR(cmd
) & _IOC_WRITE
) {
1946 if (_IOC_DIR(cmd
) & _IOC_READ
) {
1953 inarg
.in_size
= in_size
= iov_length(in_iov
, in_iovs
);
1954 inarg
.out_size
= out_size
= iov_length(out_iov
, out_iovs
);
1957 * Out data can be used either for actual out data or iovs,
1958 * make sure there always is at least one page.
1960 out_size
= max_t(size_t, out_size
, PAGE_SIZE
);
1961 max_pages
= DIV_ROUND_UP(max(in_size
, out_size
), PAGE_SIZE
);
1963 /* make sure there are enough buffer pages and init request with them */
1965 if (max_pages
> FUSE_MAX_PAGES_PER_REQ
)
1967 while (num_pages
< max_pages
) {
1968 pages
[num_pages
] = alloc_page(GFP_KERNEL
| __GFP_HIGHMEM
);
1969 if (!pages
[num_pages
])
1974 req
= fuse_get_req(fc
, num_pages
);
1980 memcpy(req
->pages
, pages
, sizeof(req
->pages
[0]) * num_pages
);
1981 req
->num_pages
= num_pages
;
1982 fuse_page_descs_length_init(req
, 0, req
->num_pages
);
1984 /* okay, let's send it to the client */
1985 req
->in
.h
.opcode
= FUSE_IOCTL
;
1986 req
->in
.h
.nodeid
= ff
->nodeid
;
1987 req
->in
.numargs
= 1;
1988 req
->in
.args
[0].size
= sizeof(inarg
);
1989 req
->in
.args
[0].value
= &inarg
;
1992 req
->in
.args
[1].size
= in_size
;
1993 req
->in
.argpages
= 1;
1995 err
= fuse_ioctl_copy_user(pages
, in_iov
, in_iovs
, in_size
,
2001 req
->out
.numargs
= 2;
2002 req
->out
.args
[0].size
= sizeof(outarg
);
2003 req
->out
.args
[0].value
= &outarg
;
2004 req
->out
.args
[1].size
= out_size
;
2005 req
->out
.argpages
= 1;
2006 req
->out
.argvar
= 1;
2008 fuse_request_send(fc
, req
);
2009 err
= req
->out
.h
.error
;
2010 transferred
= req
->out
.args
[1].size
;
2011 fuse_put_request(fc
, req
);
2016 /* did it ask for retry? */
2017 if (outarg
.flags
& FUSE_IOCTL_RETRY
) {
2020 /* no retry if in restricted mode */
2022 if (!(flags
& FUSE_IOCTL_UNRESTRICTED
))
2025 in_iovs
= outarg
.in_iovs
;
2026 out_iovs
= outarg
.out_iovs
;
2029 * Make sure things are in boundary, separate checks
2030 * are to protect against overflow.
2033 if (in_iovs
> FUSE_IOCTL_MAX_IOV
||
2034 out_iovs
> FUSE_IOCTL_MAX_IOV
||
2035 in_iovs
+ out_iovs
> FUSE_IOCTL_MAX_IOV
)
2038 vaddr
= kmap_atomic(pages
[0]);
2039 err
= fuse_copy_ioctl_iovec(fc
, iov_page
, vaddr
,
2040 transferred
, in_iovs
+ out_iovs
,
2041 (flags
& FUSE_IOCTL_COMPAT
) != 0);
2042 kunmap_atomic(vaddr
);
2047 out_iov
= in_iov
+ in_iovs
;
2049 err
= fuse_verify_ioctl_iov(in_iov
, in_iovs
);
2053 err
= fuse_verify_ioctl_iov(out_iov
, out_iovs
);
2061 if (transferred
> inarg
.out_size
)
2064 err
= fuse_ioctl_copy_user(pages
, out_iov
, out_iovs
, transferred
, true);
2067 fuse_put_request(fc
, req
);
2068 free_page((unsigned long) iov_page
);
2070 __free_page(pages
[--num_pages
]);
2073 return err
? err
: outarg
.result
;
2075 EXPORT_SYMBOL_GPL(fuse_do_ioctl
);
2077 long fuse_ioctl_common(struct file
*file
, unsigned int cmd
,
2078 unsigned long arg
, unsigned int flags
)
2080 struct inode
*inode
= file_inode(file
);
2081 struct fuse_conn
*fc
= get_fuse_conn(inode
);
2083 if (!fuse_allow_current_process(fc
))
2086 if (is_bad_inode(inode
))
2089 return fuse_do_ioctl(file
, cmd
, arg
, flags
);
2092 static long fuse_file_ioctl(struct file
*file
, unsigned int cmd
,
2095 return fuse_ioctl_common(file
, cmd
, arg
, 0);
2098 static long fuse_file_compat_ioctl(struct file
*file
, unsigned int cmd
,
2101 return fuse_ioctl_common(file
, cmd
, arg
, FUSE_IOCTL_COMPAT
);
2105 * All files which have been polled are linked to RB tree
2106 * fuse_conn->polled_files which is indexed by kh. Walk the tree and
2107 * find the matching one.
2109 static struct rb_node
**fuse_find_polled_node(struct fuse_conn
*fc
, u64 kh
,
2110 struct rb_node
**parent_out
)
2112 struct rb_node
**link
= &fc
->polled_files
.rb_node
;
2113 struct rb_node
*last
= NULL
;
2116 struct fuse_file
*ff
;
2119 ff
= rb_entry(last
, struct fuse_file
, polled_node
);
2122 link
= &last
->rb_left
;
2123 else if (kh
> ff
->kh
)
2124 link
= &last
->rb_right
;
2135 * The file is about to be polled. Make sure it's on the polled_files
2136 * RB tree. Note that files once added to the polled_files tree are
2137 * not removed before the file is released. This is because a file
2138 * polled once is likely to be polled again.
2140 static void fuse_register_polled_file(struct fuse_conn
*fc
,
2141 struct fuse_file
*ff
)
2143 spin_lock(&fc
->lock
);
2144 if (RB_EMPTY_NODE(&ff
->polled_node
)) {
2145 struct rb_node
**link
, *parent
;
2147 link
= fuse_find_polled_node(fc
, ff
->kh
, &parent
);
2149 rb_link_node(&ff
->polled_node
, parent
, link
);
2150 rb_insert_color(&ff
->polled_node
, &fc
->polled_files
);
2152 spin_unlock(&fc
->lock
);
2155 unsigned fuse_file_poll(struct file
*file
, poll_table
*wait
)
2157 struct fuse_file
*ff
= file
->private_data
;
2158 struct fuse_conn
*fc
= ff
->fc
;
2159 struct fuse_poll_in inarg
= { .fh
= ff
->fh
, .kh
= ff
->kh
};
2160 struct fuse_poll_out outarg
;
2161 struct fuse_req
*req
;
2165 return DEFAULT_POLLMASK
;
2167 poll_wait(file
, &ff
->poll_wait
, wait
);
2168 inarg
.events
= (__u32
)poll_requested_events(wait
);
2171 * Ask for notification iff there's someone waiting for it.
2172 * The client may ignore the flag and always notify.
2174 if (waitqueue_active(&ff
->poll_wait
)) {
2175 inarg
.flags
|= FUSE_POLL_SCHEDULE_NOTIFY
;
2176 fuse_register_polled_file(fc
, ff
);
2179 req
= fuse_get_req_nopages(fc
);
2183 req
->in
.h
.opcode
= FUSE_POLL
;
2184 req
->in
.h
.nodeid
= ff
->nodeid
;
2185 req
->in
.numargs
= 1;
2186 req
->in
.args
[0].size
= sizeof(inarg
);
2187 req
->in
.args
[0].value
= &inarg
;
2188 req
->out
.numargs
= 1;
2189 req
->out
.args
[0].size
= sizeof(outarg
);
2190 req
->out
.args
[0].value
= &outarg
;
2191 fuse_request_send(fc
, req
);
2192 err
= req
->out
.h
.error
;
2193 fuse_put_request(fc
, req
);
2196 return outarg
.revents
;
2197 if (err
== -ENOSYS
) {
2199 return DEFAULT_POLLMASK
;
2203 EXPORT_SYMBOL_GPL(fuse_file_poll
);
2206 * This is called from fuse_handle_notify() on FUSE_NOTIFY_POLL and
2207 * wakes up the poll waiters.
2209 int fuse_notify_poll_wakeup(struct fuse_conn
*fc
,
2210 struct fuse_notify_poll_wakeup_out
*outarg
)
2212 u64 kh
= outarg
->kh
;
2213 struct rb_node
**link
;
2215 spin_lock(&fc
->lock
);
2217 link
= fuse_find_polled_node(fc
, kh
, NULL
);
2219 struct fuse_file
*ff
;
2221 ff
= rb_entry(*link
, struct fuse_file
, polled_node
);
2222 wake_up_interruptible_sync(&ff
->poll_wait
);
2225 spin_unlock(&fc
->lock
);
2230 fuse_direct_IO(int rw
, struct kiocb
*iocb
, const struct iovec
*iov
,
2231 loff_t offset
, unsigned long nr_segs
)
2234 struct file
*file
= NULL
;
2237 file
= iocb
->ki_filp
;
2241 ret
= __fuse_direct_write(file
, iov
, nr_segs
, &pos
);
2243 ret
= __fuse_direct_read(file
, iov
, nr_segs
, &pos
);
2248 static long fuse_file_fallocate(struct file
*file
, int mode
, loff_t offset
,
2251 struct fuse_file
*ff
= file
->private_data
;
2252 struct fuse_conn
*fc
= ff
->fc
;
2253 struct fuse_req
*req
;
2254 struct fuse_fallocate_in inarg
= {
2262 if (fc
->no_fallocate
)
2265 req
= fuse_get_req_nopages(fc
);
2267 return PTR_ERR(req
);
2269 req
->in
.h
.opcode
= FUSE_FALLOCATE
;
2270 req
->in
.h
.nodeid
= ff
->nodeid
;
2271 req
->in
.numargs
= 1;
2272 req
->in
.args
[0].size
= sizeof(inarg
);
2273 req
->in
.args
[0].value
= &inarg
;
2274 fuse_request_send(fc
, req
);
2275 err
= req
->out
.h
.error
;
2276 if (err
== -ENOSYS
) {
2277 fc
->no_fallocate
= 1;
2280 fuse_put_request(fc
, req
);
2285 static const struct file_operations fuse_file_operations
= {
2286 .llseek
= fuse_file_llseek
,
2287 .read
= do_sync_read
,
2288 .aio_read
= fuse_file_aio_read
,
2289 .write
= do_sync_write
,
2290 .aio_write
= fuse_file_aio_write
,
2291 .mmap
= fuse_file_mmap
,
2293 .flush
= fuse_flush
,
2294 .release
= fuse_release
,
2295 .fsync
= fuse_fsync
,
2296 .lock
= fuse_file_lock
,
2297 .flock
= fuse_file_flock
,
2298 .splice_read
= generic_file_splice_read
,
2299 .unlocked_ioctl
= fuse_file_ioctl
,
2300 .compat_ioctl
= fuse_file_compat_ioctl
,
2301 .poll
= fuse_file_poll
,
2302 .fallocate
= fuse_file_fallocate
,
2305 static const struct file_operations fuse_direct_io_file_operations
= {
2306 .llseek
= fuse_file_llseek
,
2307 .read
= fuse_direct_read
,
2308 .write
= fuse_direct_write
,
2309 .mmap
= fuse_direct_mmap
,
2311 .flush
= fuse_flush
,
2312 .release
= fuse_release
,
2313 .fsync
= fuse_fsync
,
2314 .lock
= fuse_file_lock
,
2315 .flock
= fuse_file_flock
,
2316 .unlocked_ioctl
= fuse_file_ioctl
,
2317 .compat_ioctl
= fuse_file_compat_ioctl
,
2318 .poll
= fuse_file_poll
,
2319 .fallocate
= fuse_file_fallocate
,
2320 /* no splice_read */
2323 static const struct address_space_operations fuse_file_aops
= {
2324 .readpage
= fuse_readpage
,
2325 .writepage
= fuse_writepage
,
2326 .launder_page
= fuse_launder_page
,
2327 .readpages
= fuse_readpages
,
2328 .set_page_dirty
= __set_page_dirty_nobuffers
,
2330 .direct_IO
= fuse_direct_IO
,
2333 void fuse_init_file_inode(struct inode
*inode
)
2335 inode
->i_fop
= &fuse_file_operations
;
2336 inode
->i_data
.a_ops
= &fuse_file_aops
;