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>
18 #include <linux/aio.h>
20 static const struct file_operations fuse_direct_io_file_operations
;
22 static int fuse_send_open(struct fuse_conn
*fc
, u64 nodeid
, struct file
*file
,
23 int opcode
, struct fuse_open_out
*outargp
)
25 struct fuse_open_in inarg
;
29 req
= fuse_get_req_nopages(fc
);
33 memset(&inarg
, 0, sizeof(inarg
));
34 inarg
.flags
= file
->f_flags
& ~(O_CREAT
| O_EXCL
| O_NOCTTY
);
35 if (!fc
->atomic_o_trunc
)
36 inarg
.flags
&= ~O_TRUNC
;
37 req
->in
.h
.opcode
= opcode
;
38 req
->in
.h
.nodeid
= nodeid
;
40 req
->in
.args
[0].size
= sizeof(inarg
);
41 req
->in
.args
[0].value
= &inarg
;
43 req
->out
.args
[0].size
= sizeof(*outargp
);
44 req
->out
.args
[0].value
= outargp
;
45 fuse_request_send(fc
, req
);
46 err
= req
->out
.h
.error
;
47 fuse_put_request(fc
, req
);
52 struct fuse_file
*fuse_file_alloc(struct fuse_conn
*fc
)
56 ff
= kmalloc(sizeof(struct fuse_file
), GFP_KERNEL
);
61 ff
->reserved_req
= fuse_request_alloc(0);
62 if (unlikely(!ff
->reserved_req
)) {
67 INIT_LIST_HEAD(&ff
->write_entry
);
68 atomic_set(&ff
->count
, 0);
69 RB_CLEAR_NODE(&ff
->polled_node
);
70 init_waitqueue_head(&ff
->poll_wait
);
74 spin_unlock(&fc
->lock
);
79 void fuse_file_free(struct fuse_file
*ff
)
81 fuse_request_free(ff
->reserved_req
);
85 struct fuse_file
*fuse_file_get(struct fuse_file
*ff
)
87 atomic_inc(&ff
->count
);
91 static void fuse_release_async(struct work_struct
*work
)
97 req
= container_of(work
, struct fuse_req
, misc
.release
.work
);
98 path
= req
->misc
.release
.path
;
99 fc
= get_fuse_conn(path
.dentry
->d_inode
);
101 fuse_put_request(fc
, req
);
105 static void fuse_release_end(struct fuse_conn
*fc
, struct fuse_req
*req
)
107 if (fc
->destroy_req
) {
109 * If this is a fuseblk mount, then it's possible that
110 * releasing the path will result in releasing the
111 * super block and sending the DESTROY request. If
112 * the server is single threaded, this would hang.
113 * For this reason do the path_put() in a separate
116 atomic_inc(&req
->count
);
117 INIT_WORK(&req
->misc
.release
.work
, fuse_release_async
);
118 schedule_work(&req
->misc
.release
.work
);
120 path_put(&req
->misc
.release
.path
);
124 static void fuse_file_put(struct fuse_file
*ff
, bool sync
)
126 if (atomic_dec_and_test(&ff
->count
)) {
127 struct fuse_req
*req
= ff
->reserved_req
;
130 fuse_request_send(ff
->fc
, req
);
131 path_put(&req
->misc
.release
.path
);
132 fuse_put_request(ff
->fc
, req
);
134 req
->end
= fuse_release_end
;
135 fuse_request_send_background(ff
->fc
, req
);
141 int fuse_do_open(struct fuse_conn
*fc
, u64 nodeid
, struct file
*file
,
144 struct fuse_open_out outarg
;
145 struct fuse_file
*ff
;
147 int opcode
= isdir
? FUSE_OPENDIR
: FUSE_OPEN
;
149 ff
= fuse_file_alloc(fc
);
153 err
= fuse_send_open(fc
, nodeid
, file
, opcode
, &outarg
);
160 outarg
.open_flags
&= ~FOPEN_DIRECT_IO
;
164 ff
->open_flags
= outarg
.open_flags
;
165 file
->private_data
= fuse_file_get(ff
);
169 EXPORT_SYMBOL_GPL(fuse_do_open
);
171 void fuse_finish_open(struct inode
*inode
, struct file
*file
)
173 struct fuse_file
*ff
= file
->private_data
;
174 struct fuse_conn
*fc
= get_fuse_conn(inode
);
176 if (ff
->open_flags
& FOPEN_DIRECT_IO
)
177 file
->f_op
= &fuse_direct_io_file_operations
;
178 if (!(ff
->open_flags
& FOPEN_KEEP_CACHE
))
179 invalidate_inode_pages2(inode
->i_mapping
);
180 if (ff
->open_flags
& FOPEN_NONSEEKABLE
)
181 nonseekable_open(inode
, file
);
182 if (fc
->atomic_o_trunc
&& (file
->f_flags
& O_TRUNC
)) {
183 struct fuse_inode
*fi
= get_fuse_inode(inode
);
185 spin_lock(&fc
->lock
);
186 fi
->attr_version
= ++fc
->attr_version
;
187 i_size_write(inode
, 0);
188 spin_unlock(&fc
->lock
);
189 fuse_invalidate_attr(inode
);
193 int fuse_open_common(struct inode
*inode
, struct file
*file
, bool isdir
)
195 struct fuse_conn
*fc
= get_fuse_conn(inode
);
198 err
= generic_file_open(inode
, file
);
202 err
= fuse_do_open(fc
, get_node_id(inode
), file
, isdir
);
206 fuse_finish_open(inode
, file
);
211 static void fuse_prepare_release(struct fuse_file
*ff
, int flags
, int opcode
)
213 struct fuse_conn
*fc
= ff
->fc
;
214 struct fuse_req
*req
= ff
->reserved_req
;
215 struct fuse_release_in
*inarg
= &req
->misc
.release
.in
;
217 spin_lock(&fc
->lock
);
218 list_del(&ff
->write_entry
);
219 if (!RB_EMPTY_NODE(&ff
->polled_node
))
220 rb_erase(&ff
->polled_node
, &fc
->polled_files
);
221 spin_unlock(&fc
->lock
);
223 wake_up_interruptible_all(&ff
->poll_wait
);
226 inarg
->flags
= flags
;
227 req
->in
.h
.opcode
= opcode
;
228 req
->in
.h
.nodeid
= ff
->nodeid
;
230 req
->in
.args
[0].size
= sizeof(struct fuse_release_in
);
231 req
->in
.args
[0].value
= inarg
;
234 void fuse_release_common(struct file
*file
, int opcode
)
236 struct fuse_file
*ff
;
237 struct fuse_req
*req
;
239 ff
= file
->private_data
;
243 req
= ff
->reserved_req
;
244 fuse_prepare_release(ff
, file
->f_flags
, opcode
);
247 struct fuse_release_in
*inarg
= &req
->misc
.release
.in
;
248 inarg
->release_flags
|= FUSE_RELEASE_FLOCK_UNLOCK
;
249 inarg
->lock_owner
= fuse_lock_owner_id(ff
->fc
,
252 /* Hold vfsmount and dentry until release is finished */
253 path_get(&file
->f_path
);
254 req
->misc
.release
.path
= file
->f_path
;
257 * Normally this will send the RELEASE request, however if
258 * some asynchronous READ or WRITE requests are outstanding,
259 * the sending will be delayed.
261 * Make the release synchronous if this is a fuseblk mount,
262 * synchronous RELEASE is allowed (and desirable) in this case
263 * because the server can be trusted not to screw up.
265 fuse_file_put(ff
, ff
->fc
->destroy_req
!= NULL
);
268 static int fuse_open(struct inode
*inode
, struct file
*file
)
270 return fuse_open_common(inode
, file
, false);
273 static int fuse_release(struct inode
*inode
, struct file
*file
)
275 fuse_release_common(file
, FUSE_RELEASE
);
277 /* return value is ignored by VFS */
281 void fuse_sync_release(struct fuse_file
*ff
, int flags
)
283 WARN_ON(atomic_read(&ff
->count
) > 1);
284 fuse_prepare_release(ff
, flags
, FUSE_RELEASE
);
285 ff
->reserved_req
->force
= 1;
286 fuse_request_send(ff
->fc
, ff
->reserved_req
);
287 fuse_put_request(ff
->fc
, ff
->reserved_req
);
290 EXPORT_SYMBOL_GPL(fuse_sync_release
);
293 * Scramble the ID space with XTEA, so that the value of the files_struct
294 * pointer is not exposed to userspace.
296 u64
fuse_lock_owner_id(struct fuse_conn
*fc
, fl_owner_t id
)
298 u32
*k
= fc
->scramble_key
;
299 u64 v
= (unsigned long) id
;
305 for (i
= 0; i
< 32; i
++) {
306 v0
+= ((v1
<< 4 ^ v1
>> 5) + v1
) ^ (sum
+ k
[sum
& 3]);
308 v1
+= ((v0
<< 4 ^ v0
>> 5) + v0
) ^ (sum
+ k
[sum
>>11 & 3]);
311 return (u64
) v0
+ ((u64
) v1
<< 32);
315 * Check if page is under writeback
317 * This is currently done by walking the list of writepage requests
318 * for the inode, which can be pretty inefficient.
320 static bool fuse_page_is_writeback(struct inode
*inode
, pgoff_t index
)
322 struct fuse_conn
*fc
= get_fuse_conn(inode
);
323 struct fuse_inode
*fi
= get_fuse_inode(inode
);
324 struct fuse_req
*req
;
327 spin_lock(&fc
->lock
);
328 list_for_each_entry(req
, &fi
->writepages
, writepages_entry
) {
331 BUG_ON(req
->inode
!= inode
);
332 curr_index
= req
->misc
.write
.in
.offset
>> PAGE_CACHE_SHIFT
;
333 if (curr_index
== index
) {
338 spin_unlock(&fc
->lock
);
344 * Wait for page writeback to be completed.
346 * Since fuse doesn't rely on the VM writeback tracking, this has to
347 * use some other means.
349 static int fuse_wait_on_page_writeback(struct inode
*inode
, pgoff_t index
)
351 struct fuse_inode
*fi
= get_fuse_inode(inode
);
353 wait_event(fi
->page_waitq
, !fuse_page_is_writeback(inode
, index
));
357 static int fuse_flush(struct file
*file
, fl_owner_t id
)
359 struct inode
*inode
= file_inode(file
);
360 struct fuse_conn
*fc
= get_fuse_conn(inode
);
361 struct fuse_file
*ff
= file
->private_data
;
362 struct fuse_req
*req
;
363 struct fuse_flush_in inarg
;
366 if (is_bad_inode(inode
))
372 req
= fuse_get_req_nofail_nopages(fc
, file
);
373 memset(&inarg
, 0, sizeof(inarg
));
375 inarg
.lock_owner
= fuse_lock_owner_id(fc
, id
);
376 req
->in
.h
.opcode
= FUSE_FLUSH
;
377 req
->in
.h
.nodeid
= get_node_id(inode
);
379 req
->in
.args
[0].size
= sizeof(inarg
);
380 req
->in
.args
[0].value
= &inarg
;
382 fuse_request_send(fc
, req
);
383 err
= req
->out
.h
.error
;
384 fuse_put_request(fc
, req
);
385 if (err
== -ENOSYS
) {
393 * Wait for all pending writepages on the inode to finish.
395 * This is currently done by blocking further writes with FUSE_NOWRITE
396 * and waiting for all sent writes to complete.
398 * This must be called under i_mutex, otherwise the FUSE_NOWRITE usage
399 * could conflict with truncation.
401 static void fuse_sync_writes(struct inode
*inode
)
403 fuse_set_nowrite(inode
);
404 fuse_release_nowrite(inode
);
407 int fuse_fsync_common(struct file
*file
, loff_t start
, loff_t end
,
408 int datasync
, int isdir
)
410 struct inode
*inode
= file
->f_mapping
->host
;
411 struct fuse_conn
*fc
= get_fuse_conn(inode
);
412 struct fuse_file
*ff
= file
->private_data
;
413 struct fuse_req
*req
;
414 struct fuse_fsync_in inarg
;
417 if (is_bad_inode(inode
))
420 err
= filemap_write_and_wait_range(inode
->i_mapping
, start
, end
);
424 if ((!isdir
&& fc
->no_fsync
) || (isdir
&& fc
->no_fsyncdir
))
427 mutex_lock(&inode
->i_mutex
);
430 * Start writeback against all dirty pages of the inode, then
431 * wait for all outstanding writes, before sending the FSYNC
434 err
= write_inode_now(inode
, 0);
438 fuse_sync_writes(inode
);
440 req
= fuse_get_req_nopages(fc
);
446 memset(&inarg
, 0, sizeof(inarg
));
448 inarg
.fsync_flags
= datasync
? 1 : 0;
449 req
->in
.h
.opcode
= isdir
? FUSE_FSYNCDIR
: FUSE_FSYNC
;
450 req
->in
.h
.nodeid
= get_node_id(inode
);
452 req
->in
.args
[0].size
= sizeof(inarg
);
453 req
->in
.args
[0].value
= &inarg
;
454 fuse_request_send(fc
, req
);
455 err
= req
->out
.h
.error
;
456 fuse_put_request(fc
, req
);
457 if (err
== -ENOSYS
) {
465 mutex_unlock(&inode
->i_mutex
);
469 static int fuse_fsync(struct file
*file
, loff_t start
, loff_t end
,
472 return fuse_fsync_common(file
, start
, end
, datasync
, 0);
475 void fuse_read_fill(struct fuse_req
*req
, struct file
*file
, loff_t pos
,
476 size_t count
, int opcode
)
478 struct fuse_read_in
*inarg
= &req
->misc
.read
.in
;
479 struct fuse_file
*ff
= file
->private_data
;
484 inarg
->flags
= file
->f_flags
;
485 req
->in
.h
.opcode
= opcode
;
486 req
->in
.h
.nodeid
= ff
->nodeid
;
488 req
->in
.args
[0].size
= sizeof(struct fuse_read_in
);
489 req
->in
.args
[0].value
= inarg
;
491 req
->out
.numargs
= 1;
492 req
->out
.args
[0].size
= count
;
495 static size_t fuse_send_read(struct fuse_req
*req
, struct file
*file
,
496 loff_t pos
, size_t count
, fl_owner_t owner
)
498 struct fuse_file
*ff
= file
->private_data
;
499 struct fuse_conn
*fc
= ff
->fc
;
501 fuse_read_fill(req
, file
, pos
, count
, FUSE_READ
);
503 struct fuse_read_in
*inarg
= &req
->misc
.read
.in
;
505 inarg
->read_flags
|= FUSE_READ_LOCKOWNER
;
506 inarg
->lock_owner
= fuse_lock_owner_id(fc
, owner
);
508 fuse_request_send(fc
, req
);
509 return req
->out
.args
[0].size
;
512 static void fuse_read_update_size(struct inode
*inode
, loff_t size
,
515 struct fuse_conn
*fc
= get_fuse_conn(inode
);
516 struct fuse_inode
*fi
= get_fuse_inode(inode
);
518 spin_lock(&fc
->lock
);
519 if (attr_ver
== fi
->attr_version
&& size
< inode
->i_size
) {
520 fi
->attr_version
= ++fc
->attr_version
;
521 i_size_write(inode
, size
);
523 spin_unlock(&fc
->lock
);
526 static int fuse_readpage(struct file
*file
, struct page
*page
)
528 struct inode
*inode
= page
->mapping
->host
;
529 struct fuse_conn
*fc
= get_fuse_conn(inode
);
530 struct fuse_req
*req
;
532 loff_t pos
= page_offset(page
);
533 size_t count
= PAGE_CACHE_SIZE
;
538 if (is_bad_inode(inode
))
542 * Page writeback can extend beyond the lifetime of the
543 * page-cache page, so make sure we read a properly synced
546 fuse_wait_on_page_writeback(inode
, page
->index
);
548 req
= fuse_get_req(fc
, 1);
553 attr_ver
= fuse_get_attr_version(fc
);
555 req
->out
.page_zeroing
= 1;
556 req
->out
.argpages
= 1;
558 req
->pages
[0] = page
;
559 req
->page_descs
[0].length
= count
;
560 num_read
= fuse_send_read(req
, file
, pos
, count
, NULL
);
561 err
= req
->out
.h
.error
;
562 fuse_put_request(fc
, req
);
566 * Short read means EOF. If file size is larger, truncate it
568 if (num_read
< count
)
569 fuse_read_update_size(inode
, pos
+ num_read
, attr_ver
);
571 SetPageUptodate(page
);
574 fuse_invalidate_attr(inode
); /* atime changed */
580 static void fuse_readpages_end(struct fuse_conn
*fc
, struct fuse_req
*req
)
583 size_t count
= req
->misc
.read
.in
.size
;
584 size_t num_read
= req
->out
.args
[0].size
;
585 struct address_space
*mapping
= NULL
;
587 for (i
= 0; mapping
== NULL
&& i
< req
->num_pages
; i
++)
588 mapping
= req
->pages
[i
]->mapping
;
591 struct inode
*inode
= mapping
->host
;
594 * Short read means EOF. If file size is larger, truncate it
596 if (!req
->out
.h
.error
&& num_read
< count
) {
599 pos
= page_offset(req
->pages
[0]) + num_read
;
600 fuse_read_update_size(inode
, pos
,
601 req
->misc
.read
.attr_ver
);
603 fuse_invalidate_attr(inode
); /* atime changed */
606 for (i
= 0; i
< req
->num_pages
; i
++) {
607 struct page
*page
= req
->pages
[i
];
608 if (!req
->out
.h
.error
)
609 SetPageUptodate(page
);
613 page_cache_release(page
);
616 fuse_file_put(req
->ff
, false);
619 static void fuse_send_readpages(struct fuse_req
*req
, struct file
*file
)
621 struct fuse_file
*ff
= file
->private_data
;
622 struct fuse_conn
*fc
= ff
->fc
;
623 loff_t pos
= page_offset(req
->pages
[0]);
624 size_t count
= req
->num_pages
<< PAGE_CACHE_SHIFT
;
626 req
->out
.argpages
= 1;
627 req
->out
.page_zeroing
= 1;
628 req
->out
.page_replace
= 1;
629 fuse_read_fill(req
, file
, pos
, count
, FUSE_READ
);
630 req
->misc
.read
.attr_ver
= fuse_get_attr_version(fc
);
631 if (fc
->async_read
) {
632 req
->ff
= fuse_file_get(ff
);
633 req
->end
= fuse_readpages_end
;
634 fuse_request_send_background(fc
, req
);
636 fuse_request_send(fc
, req
);
637 fuse_readpages_end(fc
, req
);
638 fuse_put_request(fc
, req
);
642 struct fuse_fill_data
{
643 struct fuse_req
*req
;
649 static int fuse_readpages_fill(void *_data
, struct page
*page
)
651 struct fuse_fill_data
*data
= _data
;
652 struct fuse_req
*req
= data
->req
;
653 struct inode
*inode
= data
->inode
;
654 struct fuse_conn
*fc
= get_fuse_conn(inode
);
656 fuse_wait_on_page_writeback(inode
, page
->index
);
658 if (req
->num_pages
&&
659 (req
->num_pages
== FUSE_MAX_PAGES_PER_REQ
||
660 (req
->num_pages
+ 1) * PAGE_CACHE_SIZE
> fc
->max_read
||
661 req
->pages
[req
->num_pages
- 1]->index
+ 1 != page
->index
)) {
662 int nr_alloc
= min_t(unsigned, data
->nr_pages
,
663 FUSE_MAX_PAGES_PER_REQ
);
664 fuse_send_readpages(req
, data
->file
);
665 data
->req
= req
= fuse_get_req(fc
, nr_alloc
);
672 if (WARN_ON(req
->num_pages
>= req
->max_pages
)) {
673 fuse_put_request(fc
, req
);
677 page_cache_get(page
);
678 req
->pages
[req
->num_pages
] = page
;
679 req
->page_descs
[req
->num_pages
].length
= PAGE_SIZE
;
685 static int fuse_readpages(struct file
*file
, struct address_space
*mapping
,
686 struct list_head
*pages
, unsigned nr_pages
)
688 struct inode
*inode
= mapping
->host
;
689 struct fuse_conn
*fc
= get_fuse_conn(inode
);
690 struct fuse_fill_data data
;
692 int nr_alloc
= min_t(unsigned, nr_pages
, FUSE_MAX_PAGES_PER_REQ
);
695 if (is_bad_inode(inode
))
700 data
.req
= fuse_get_req(fc
, nr_alloc
);
701 data
.nr_pages
= nr_pages
;
702 err
= PTR_ERR(data
.req
);
703 if (IS_ERR(data
.req
))
706 err
= read_cache_pages(mapping
, pages
, fuse_readpages_fill
, &data
);
708 if (data
.req
->num_pages
)
709 fuse_send_readpages(data
.req
, file
);
711 fuse_put_request(fc
, data
.req
);
717 static ssize_t
fuse_file_aio_read(struct kiocb
*iocb
, const struct iovec
*iov
,
718 unsigned long nr_segs
, loff_t pos
)
720 struct inode
*inode
= iocb
->ki_filp
->f_mapping
->host
;
721 struct fuse_conn
*fc
= get_fuse_conn(inode
);
724 * In auto invalidate mode, always update attributes on read.
725 * Otherwise, only update if we attempt to read past EOF (to ensure
726 * i_size is up to date).
728 if (fc
->auto_inval_data
||
729 (pos
+ iov_length(iov
, nr_segs
) > i_size_read(inode
))) {
731 err
= fuse_update_attributes(inode
, NULL
, iocb
->ki_filp
, NULL
);
736 return generic_file_aio_read(iocb
, iov
, nr_segs
, pos
);
739 static void fuse_write_fill(struct fuse_req
*req
, struct fuse_file
*ff
,
740 loff_t pos
, size_t count
)
742 struct fuse_write_in
*inarg
= &req
->misc
.write
.in
;
743 struct fuse_write_out
*outarg
= &req
->misc
.write
.out
;
748 req
->in
.h
.opcode
= FUSE_WRITE
;
749 req
->in
.h
.nodeid
= ff
->nodeid
;
751 if (ff
->fc
->minor
< 9)
752 req
->in
.args
[0].size
= FUSE_COMPAT_WRITE_IN_SIZE
;
754 req
->in
.args
[0].size
= sizeof(struct fuse_write_in
);
755 req
->in
.args
[0].value
= inarg
;
756 req
->in
.args
[1].size
= count
;
757 req
->out
.numargs
= 1;
758 req
->out
.args
[0].size
= sizeof(struct fuse_write_out
);
759 req
->out
.args
[0].value
= outarg
;
762 static size_t fuse_send_write(struct fuse_req
*req
, struct file
*file
,
763 loff_t pos
, size_t count
, fl_owner_t owner
)
765 struct fuse_file
*ff
= file
->private_data
;
766 struct fuse_conn
*fc
= ff
->fc
;
767 struct fuse_write_in
*inarg
= &req
->misc
.write
.in
;
769 fuse_write_fill(req
, ff
, pos
, count
);
770 inarg
->flags
= file
->f_flags
;
772 inarg
->write_flags
|= FUSE_WRITE_LOCKOWNER
;
773 inarg
->lock_owner
= fuse_lock_owner_id(fc
, owner
);
775 fuse_request_send(fc
, req
);
776 return req
->misc
.write
.out
.size
;
779 void fuse_write_update_size(struct inode
*inode
, loff_t pos
)
781 struct fuse_conn
*fc
= get_fuse_conn(inode
);
782 struct fuse_inode
*fi
= get_fuse_inode(inode
);
784 spin_lock(&fc
->lock
);
785 fi
->attr_version
= ++fc
->attr_version
;
786 if (pos
> inode
->i_size
)
787 i_size_write(inode
, pos
);
788 spin_unlock(&fc
->lock
);
791 static size_t fuse_send_write_pages(struct fuse_req
*req
, struct file
*file
,
792 struct inode
*inode
, loff_t pos
,
799 for (i
= 0; i
< req
->num_pages
; i
++)
800 fuse_wait_on_page_writeback(inode
, req
->pages
[i
]->index
);
802 res
= fuse_send_write(req
, file
, pos
, count
, NULL
);
804 offset
= req
->page_descs
[0].offset
;
806 for (i
= 0; i
< req
->num_pages
; i
++) {
807 struct page
*page
= req
->pages
[i
];
809 if (!req
->out
.h
.error
&& !offset
&& count
>= PAGE_CACHE_SIZE
)
810 SetPageUptodate(page
);
812 if (count
> PAGE_CACHE_SIZE
- offset
)
813 count
-= PAGE_CACHE_SIZE
- offset
;
819 page_cache_release(page
);
825 static ssize_t
fuse_fill_write_pages(struct fuse_req
*req
,
826 struct address_space
*mapping
,
827 struct iov_iter
*ii
, loff_t pos
)
829 struct fuse_conn
*fc
= get_fuse_conn(mapping
->host
);
830 unsigned offset
= pos
& (PAGE_CACHE_SIZE
- 1);
834 req
->in
.argpages
= 1;
835 req
->page_descs
[0].offset
= offset
;
840 pgoff_t index
= pos
>> PAGE_CACHE_SHIFT
;
841 size_t bytes
= min_t(size_t, PAGE_CACHE_SIZE
- offset
,
844 bytes
= min_t(size_t, bytes
, fc
->max_write
- count
);
848 if (iov_iter_fault_in_readable(ii
, bytes
))
852 page
= grab_cache_page_write_begin(mapping
, index
, 0);
856 if (mapping_writably_mapped(mapping
))
857 flush_dcache_page(page
);
860 tmp
= iov_iter_copy_from_user_atomic(page
, ii
, offset
, bytes
);
862 flush_dcache_page(page
);
864 mark_page_accessed(page
);
868 page_cache_release(page
);
869 bytes
= min(bytes
, iov_iter_single_seg_count(ii
));
874 req
->pages
[req
->num_pages
] = page
;
875 req
->page_descs
[req
->num_pages
].length
= tmp
;
878 iov_iter_advance(ii
, tmp
);
882 if (offset
== PAGE_CACHE_SIZE
)
887 } while (iov_iter_count(ii
) && count
< fc
->max_write
&&
888 req
->num_pages
< req
->max_pages
&& offset
== 0);
890 return count
> 0 ? count
: err
;
893 static inline unsigned fuse_wr_pages(loff_t pos
, size_t len
)
895 return min_t(unsigned,
896 ((pos
+ len
- 1) >> PAGE_CACHE_SHIFT
) -
897 (pos
>> PAGE_CACHE_SHIFT
) + 1,
898 FUSE_MAX_PAGES_PER_REQ
);
901 static ssize_t
fuse_perform_write(struct file
*file
,
902 struct address_space
*mapping
,
903 struct iov_iter
*ii
, loff_t pos
)
905 struct inode
*inode
= mapping
->host
;
906 struct fuse_conn
*fc
= get_fuse_conn(inode
);
910 if (is_bad_inode(inode
))
914 struct fuse_req
*req
;
916 unsigned nr_pages
= fuse_wr_pages(pos
, iov_iter_count(ii
));
918 req
= fuse_get_req(fc
, nr_pages
);
924 count
= fuse_fill_write_pages(req
, mapping
, ii
, pos
);
930 num_written
= fuse_send_write_pages(req
, file
, inode
,
932 err
= req
->out
.h
.error
;
937 /* break out of the loop on short write */
938 if (num_written
!= count
)
942 fuse_put_request(fc
, req
);
943 } while (!err
&& iov_iter_count(ii
));
946 fuse_write_update_size(inode
, pos
);
948 fuse_invalidate_attr(inode
);
950 return res
> 0 ? res
: err
;
953 static ssize_t
fuse_file_aio_write(struct kiocb
*iocb
, const struct iovec
*iov
,
954 unsigned long nr_segs
, loff_t pos
)
956 struct file
*file
= iocb
->ki_filp
;
957 struct address_space
*mapping
= file
->f_mapping
;
961 ssize_t written_buffered
= 0;
962 struct inode
*inode
= mapping
->host
;
967 WARN_ON(iocb
->ki_pos
!= pos
);
970 err
= generic_segment_checks(iov
, &nr_segs
, &ocount
, VERIFY_READ
);
975 mutex_lock(&inode
->i_mutex
);
977 /* We can write back this queue in page reclaim */
978 current
->backing_dev_info
= mapping
->backing_dev_info
;
980 err
= generic_write_checks(file
, &pos
, &count
, S_ISBLK(inode
->i_mode
));
987 err
= file_remove_suid(file
);
991 err
= file_update_time(file
);
995 if (file
->f_flags
& O_DIRECT
) {
996 written
= generic_file_direct_write(iocb
, iov
, &nr_segs
,
999 if (written
< 0 || written
== count
)
1005 iov_iter_init(&i
, iov
, nr_segs
, count
, written
);
1006 written_buffered
= fuse_perform_write(file
, mapping
, &i
, pos
);
1007 if (written_buffered
< 0) {
1008 err
= written_buffered
;
1011 endbyte
= pos
+ written_buffered
- 1;
1013 err
= filemap_write_and_wait_range(file
->f_mapping
, pos
,
1018 invalidate_mapping_pages(file
->f_mapping
,
1019 pos
>> PAGE_CACHE_SHIFT
,
1020 endbyte
>> PAGE_CACHE_SHIFT
);
1022 written
+= written_buffered
;
1023 iocb
->ki_pos
= pos
+ written_buffered
;
1025 iov_iter_init(&i
, iov
, nr_segs
, count
, 0);
1026 written
= fuse_perform_write(file
, mapping
, &i
, pos
);
1028 iocb
->ki_pos
= pos
+ written
;
1031 current
->backing_dev_info
= NULL
;
1032 mutex_unlock(&inode
->i_mutex
);
1034 return written
? written
: err
;
1037 static void fuse_release_user_pages(struct fuse_req
*req
, int write
)
1041 for (i
= 0; i
< req
->num_pages
; i
++) {
1042 struct page
*page
= req
->pages
[i
];
1044 set_page_dirty_lock(page
);
1049 static inline void fuse_page_descs_length_init(struct fuse_req
*req
,
1050 unsigned index
, unsigned nr_pages
)
1054 for (i
= index
; i
< index
+ nr_pages
; i
++)
1055 req
->page_descs
[i
].length
= PAGE_SIZE
-
1056 req
->page_descs
[i
].offset
;
1059 static inline unsigned long fuse_get_user_addr(const struct iov_iter
*ii
)
1061 return (unsigned long)ii
->iov
->iov_base
+ ii
->iov_offset
;
1064 static inline size_t fuse_get_frag_size(const struct iov_iter
*ii
,
1067 return min(iov_iter_single_seg_count(ii
), max_size
);
1070 static int fuse_get_user_pages(struct fuse_req
*req
, struct iov_iter
*ii
,
1071 size_t *nbytesp
, int write
)
1073 size_t nbytes
= 0; /* # bytes already packed in req */
1075 /* Special case for kernel I/O: can copy directly into the buffer */
1076 if (segment_eq(get_fs(), KERNEL_DS
)) {
1077 unsigned long user_addr
= fuse_get_user_addr(ii
);
1078 size_t frag_size
= fuse_get_frag_size(ii
, *nbytesp
);
1081 req
->in
.args
[1].value
= (void *) user_addr
;
1083 req
->out
.args
[0].value
= (void *) user_addr
;
1085 iov_iter_advance(ii
, frag_size
);
1086 *nbytesp
= frag_size
;
1090 while (nbytes
< *nbytesp
&& req
->num_pages
< req
->max_pages
) {
1092 unsigned long user_addr
= fuse_get_user_addr(ii
);
1093 unsigned offset
= user_addr
& ~PAGE_MASK
;
1094 size_t frag_size
= fuse_get_frag_size(ii
, *nbytesp
- nbytes
);
1097 unsigned n
= req
->max_pages
- req
->num_pages
;
1098 frag_size
= min_t(size_t, frag_size
, n
<< PAGE_SHIFT
);
1100 npages
= (frag_size
+ offset
+ PAGE_SIZE
- 1) >> PAGE_SHIFT
;
1101 npages
= clamp(npages
, 1U, n
);
1103 ret
= get_user_pages_fast(user_addr
, npages
, !write
,
1104 &req
->pages
[req
->num_pages
]);
1109 frag_size
= min_t(size_t, frag_size
,
1110 (npages
<< PAGE_SHIFT
) - offset
);
1111 iov_iter_advance(ii
, frag_size
);
1113 req
->page_descs
[req
->num_pages
].offset
= offset
;
1114 fuse_page_descs_length_init(req
, req
->num_pages
, npages
);
1116 req
->num_pages
+= npages
;
1117 req
->page_descs
[req
->num_pages
- 1].length
-=
1118 (npages
<< PAGE_SHIFT
) - offset
- frag_size
;
1120 nbytes
+= frag_size
;
1124 req
->in
.argpages
= 1;
1126 req
->out
.argpages
= 1;
1133 static inline int fuse_iter_npages(const struct iov_iter
*ii_p
)
1135 struct iov_iter ii
= *ii_p
;
1138 while (iov_iter_count(&ii
) && npages
< FUSE_MAX_PAGES_PER_REQ
) {
1139 unsigned long user_addr
= fuse_get_user_addr(&ii
);
1140 unsigned offset
= user_addr
& ~PAGE_MASK
;
1141 size_t frag_size
= iov_iter_single_seg_count(&ii
);
1143 npages
+= (frag_size
+ offset
+ PAGE_SIZE
- 1) >> PAGE_SHIFT
;
1144 iov_iter_advance(&ii
, frag_size
);
1147 return min(npages
, FUSE_MAX_PAGES_PER_REQ
);
1150 ssize_t
fuse_direct_io(struct file
*file
, const struct iovec
*iov
,
1151 unsigned long nr_segs
, size_t count
, loff_t
*ppos
,
1154 struct fuse_file
*ff
= file
->private_data
;
1155 struct fuse_conn
*fc
= ff
->fc
;
1156 size_t nmax
= write
? fc
->max_write
: fc
->max_read
;
1159 struct fuse_req
*req
;
1162 iov_iter_init(&ii
, iov
, nr_segs
, count
, 0);
1164 req
= fuse_get_req(fc
, fuse_iter_npages(&ii
));
1166 return PTR_ERR(req
);
1170 fl_owner_t owner
= current
->files
;
1171 size_t nbytes
= min(count
, nmax
);
1172 int err
= fuse_get_user_pages(req
, &ii
, &nbytes
, write
);
1179 nres
= fuse_send_write(req
, file
, pos
, nbytes
, owner
);
1181 nres
= fuse_send_read(req
, file
, pos
, nbytes
, owner
);
1183 fuse_release_user_pages(req
, !write
);
1184 if (req
->out
.h
.error
) {
1186 res
= req
->out
.h
.error
;
1188 } else if (nres
> nbytes
) {
1198 fuse_put_request(fc
, req
);
1199 req
= fuse_get_req(fc
, fuse_iter_npages(&ii
));
1205 fuse_put_request(fc
, req
);
1211 EXPORT_SYMBOL_GPL(fuse_direct_io
);
1213 static ssize_t
__fuse_direct_read(struct file
*file
, const struct iovec
*iov
,
1214 unsigned long nr_segs
, loff_t
*ppos
)
1217 struct inode
*inode
= file_inode(file
);
1219 if (is_bad_inode(inode
))
1222 res
= fuse_direct_io(file
, iov
, nr_segs
, iov_length(iov
, nr_segs
),
1225 fuse_invalidate_attr(inode
);
1230 static ssize_t
fuse_direct_read(struct file
*file
, char __user
*buf
,
1231 size_t count
, loff_t
*ppos
)
1233 struct iovec iov
= { .iov_base
= buf
, .iov_len
= count
};
1234 return __fuse_direct_read(file
, &iov
, 1, ppos
);
1237 static ssize_t
__fuse_direct_write(struct file
*file
, const struct iovec
*iov
,
1238 unsigned long nr_segs
, loff_t
*ppos
)
1240 struct inode
*inode
= file_inode(file
);
1241 size_t count
= iov_length(iov
, nr_segs
);
1244 res
= generic_write_checks(file
, ppos
, &count
, 0);
1246 res
= fuse_direct_io(file
, iov
, nr_segs
, count
, ppos
, 1);
1248 fuse_write_update_size(inode
, *ppos
);
1251 fuse_invalidate_attr(inode
);
1256 static ssize_t
fuse_direct_write(struct file
*file
, const char __user
*buf
,
1257 size_t count
, loff_t
*ppos
)
1259 struct iovec iov
= { .iov_base
= (void __user
*)buf
, .iov_len
= count
};
1260 struct inode
*inode
= file_inode(file
);
1263 if (is_bad_inode(inode
))
1266 /* Don't allow parallel writes to the same file */
1267 mutex_lock(&inode
->i_mutex
);
1268 res
= __fuse_direct_write(file
, &iov
, 1, ppos
);
1269 mutex_unlock(&inode
->i_mutex
);
1274 static void fuse_writepage_free(struct fuse_conn
*fc
, struct fuse_req
*req
)
1276 __free_page(req
->pages
[0]);
1277 fuse_file_put(req
->ff
, false);
1280 static void fuse_writepage_finish(struct fuse_conn
*fc
, struct fuse_req
*req
)
1282 struct inode
*inode
= req
->inode
;
1283 struct fuse_inode
*fi
= get_fuse_inode(inode
);
1284 struct backing_dev_info
*bdi
= inode
->i_mapping
->backing_dev_info
;
1286 list_del(&req
->writepages_entry
);
1287 dec_bdi_stat(bdi
, BDI_WRITEBACK
);
1288 dec_zone_page_state(req
->pages
[0], NR_WRITEBACK_TEMP
);
1289 bdi_writeout_inc(bdi
);
1290 wake_up(&fi
->page_waitq
);
1293 /* Called under fc->lock, may release and reacquire it */
1294 static void fuse_send_writepage(struct fuse_conn
*fc
, struct fuse_req
*req
)
1295 __releases(fc
->lock
)
1296 __acquires(fc
->lock
)
1298 struct fuse_inode
*fi
= get_fuse_inode(req
->inode
);
1299 loff_t size
= i_size_read(req
->inode
);
1300 struct fuse_write_in
*inarg
= &req
->misc
.write
.in
;
1305 if (inarg
->offset
+ PAGE_CACHE_SIZE
<= size
) {
1306 inarg
->size
= PAGE_CACHE_SIZE
;
1307 } else if (inarg
->offset
< size
) {
1308 inarg
->size
= size
& (PAGE_CACHE_SIZE
- 1);
1310 /* Got truncated off completely */
1314 req
->in
.args
[1].size
= inarg
->size
;
1316 fuse_request_send_background_locked(fc
, req
);
1320 fuse_writepage_finish(fc
, req
);
1321 spin_unlock(&fc
->lock
);
1322 fuse_writepage_free(fc
, req
);
1323 fuse_put_request(fc
, req
);
1324 spin_lock(&fc
->lock
);
1328 * If fi->writectr is positive (no truncate or fsync going on) send
1329 * all queued writepage requests.
1331 * Called with fc->lock
1333 void fuse_flush_writepages(struct inode
*inode
)
1334 __releases(fc
->lock
)
1335 __acquires(fc
->lock
)
1337 struct fuse_conn
*fc
= get_fuse_conn(inode
);
1338 struct fuse_inode
*fi
= get_fuse_inode(inode
);
1339 struct fuse_req
*req
;
1341 while (fi
->writectr
>= 0 && !list_empty(&fi
->queued_writes
)) {
1342 req
= list_entry(fi
->queued_writes
.next
, struct fuse_req
, list
);
1343 list_del_init(&req
->list
);
1344 fuse_send_writepage(fc
, req
);
1348 static void fuse_writepage_end(struct fuse_conn
*fc
, struct fuse_req
*req
)
1350 struct inode
*inode
= req
->inode
;
1351 struct fuse_inode
*fi
= get_fuse_inode(inode
);
1353 mapping_set_error(inode
->i_mapping
, req
->out
.h
.error
);
1354 spin_lock(&fc
->lock
);
1356 fuse_writepage_finish(fc
, req
);
1357 spin_unlock(&fc
->lock
);
1358 fuse_writepage_free(fc
, req
);
1361 static int fuse_writepage_locked(struct page
*page
)
1363 struct address_space
*mapping
= page
->mapping
;
1364 struct inode
*inode
= mapping
->host
;
1365 struct fuse_conn
*fc
= get_fuse_conn(inode
);
1366 struct fuse_inode
*fi
= get_fuse_inode(inode
);
1367 struct fuse_req
*req
;
1368 struct fuse_file
*ff
;
1369 struct page
*tmp_page
;
1371 set_page_writeback(page
);
1373 req
= fuse_request_alloc_nofs(1);
1377 tmp_page
= alloc_page(GFP_NOFS
| __GFP_HIGHMEM
);
1381 spin_lock(&fc
->lock
);
1382 BUG_ON(list_empty(&fi
->write_files
));
1383 ff
= list_entry(fi
->write_files
.next
, struct fuse_file
, write_entry
);
1384 req
->ff
= fuse_file_get(ff
);
1385 spin_unlock(&fc
->lock
);
1387 fuse_write_fill(req
, ff
, page_offset(page
), 0);
1389 copy_highpage(tmp_page
, page
);
1390 req
->misc
.write
.in
.write_flags
|= FUSE_WRITE_CACHE
;
1391 req
->in
.argpages
= 1;
1393 req
->pages
[0] = tmp_page
;
1394 req
->page_descs
[0].offset
= 0;
1395 req
->page_descs
[0].length
= PAGE_SIZE
;
1396 req
->end
= fuse_writepage_end
;
1399 inc_bdi_stat(mapping
->backing_dev_info
, BDI_WRITEBACK
);
1400 inc_zone_page_state(tmp_page
, NR_WRITEBACK_TEMP
);
1401 end_page_writeback(page
);
1403 spin_lock(&fc
->lock
);
1404 list_add(&req
->writepages_entry
, &fi
->writepages
);
1405 list_add_tail(&req
->list
, &fi
->queued_writes
);
1406 fuse_flush_writepages(inode
);
1407 spin_unlock(&fc
->lock
);
1412 fuse_request_free(req
);
1414 end_page_writeback(page
);
1418 static int fuse_writepage(struct page
*page
, struct writeback_control
*wbc
)
1422 err
= fuse_writepage_locked(page
);
1428 static int fuse_launder_page(struct page
*page
)
1431 if (clear_page_dirty_for_io(page
)) {
1432 struct inode
*inode
= page
->mapping
->host
;
1433 err
= fuse_writepage_locked(page
);
1435 fuse_wait_on_page_writeback(inode
, page
->index
);
1441 * Write back dirty pages now, because there may not be any suitable
1444 static void fuse_vma_close(struct vm_area_struct
*vma
)
1446 filemap_write_and_wait(vma
->vm_file
->f_mapping
);
1450 * Wait for writeback against this page to complete before allowing it
1451 * to be marked dirty again, and hence written back again, possibly
1452 * before the previous writepage completed.
1454 * Block here, instead of in ->writepage(), so that the userspace fs
1455 * can only block processes actually operating on the filesystem.
1457 * Otherwise unprivileged userspace fs would be able to block
1462 * - try_to_free_pages() with order > PAGE_ALLOC_COSTLY_ORDER
1464 static int fuse_page_mkwrite(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
1466 struct page
*page
= vmf
->page
;
1468 * Don't use page->mapping as it may become NULL from a
1469 * concurrent truncate.
1471 struct inode
*inode
= vma
->vm_file
->f_mapping
->host
;
1473 fuse_wait_on_page_writeback(inode
, page
->index
);
1477 static const struct vm_operations_struct fuse_file_vm_ops
= {
1478 .close
= fuse_vma_close
,
1479 .fault
= filemap_fault
,
1480 .page_mkwrite
= fuse_page_mkwrite
,
1481 .remap_pages
= generic_file_remap_pages
,
1484 static int fuse_file_mmap(struct file
*file
, struct vm_area_struct
*vma
)
1486 if ((vma
->vm_flags
& VM_SHARED
) && (vma
->vm_flags
& VM_MAYWRITE
)) {
1487 struct inode
*inode
= file_inode(file
);
1488 struct fuse_conn
*fc
= get_fuse_conn(inode
);
1489 struct fuse_inode
*fi
= get_fuse_inode(inode
);
1490 struct fuse_file
*ff
= file
->private_data
;
1492 * file may be written through mmap, so chain it onto the
1493 * inodes's write_file list
1495 spin_lock(&fc
->lock
);
1496 if (list_empty(&ff
->write_entry
))
1497 list_add(&ff
->write_entry
, &fi
->write_files
);
1498 spin_unlock(&fc
->lock
);
1500 file_accessed(file
);
1501 vma
->vm_ops
= &fuse_file_vm_ops
;
1505 static int fuse_direct_mmap(struct file
*file
, struct vm_area_struct
*vma
)
1507 /* Can't provide the coherency needed for MAP_SHARED */
1508 if (vma
->vm_flags
& VM_MAYSHARE
)
1511 invalidate_inode_pages2(file
->f_mapping
);
1513 return generic_file_mmap(file
, vma
);
1516 static int convert_fuse_file_lock(const struct fuse_file_lock
*ffl
,
1517 struct file_lock
*fl
)
1519 switch (ffl
->type
) {
1525 if (ffl
->start
> OFFSET_MAX
|| ffl
->end
> OFFSET_MAX
||
1526 ffl
->end
< ffl
->start
)
1529 fl
->fl_start
= ffl
->start
;
1530 fl
->fl_end
= ffl
->end
;
1531 fl
->fl_pid
= ffl
->pid
;
1537 fl
->fl_type
= ffl
->type
;
1541 static void fuse_lk_fill(struct fuse_req
*req
, struct file
*file
,
1542 const struct file_lock
*fl
, int opcode
, pid_t pid
,
1545 struct inode
*inode
= file_inode(file
);
1546 struct fuse_conn
*fc
= get_fuse_conn(inode
);
1547 struct fuse_file
*ff
= file
->private_data
;
1548 struct fuse_lk_in
*arg
= &req
->misc
.lk_in
;
1551 arg
->owner
= fuse_lock_owner_id(fc
, fl
->fl_owner
);
1552 arg
->lk
.start
= fl
->fl_start
;
1553 arg
->lk
.end
= fl
->fl_end
;
1554 arg
->lk
.type
= fl
->fl_type
;
1557 arg
->lk_flags
|= FUSE_LK_FLOCK
;
1558 req
->in
.h
.opcode
= opcode
;
1559 req
->in
.h
.nodeid
= get_node_id(inode
);
1560 req
->in
.numargs
= 1;
1561 req
->in
.args
[0].size
= sizeof(*arg
);
1562 req
->in
.args
[0].value
= arg
;
1565 static int fuse_getlk(struct file
*file
, struct file_lock
*fl
)
1567 struct inode
*inode
= file_inode(file
);
1568 struct fuse_conn
*fc
= get_fuse_conn(inode
);
1569 struct fuse_req
*req
;
1570 struct fuse_lk_out outarg
;
1573 req
= fuse_get_req_nopages(fc
);
1575 return PTR_ERR(req
);
1577 fuse_lk_fill(req
, file
, fl
, FUSE_GETLK
, 0, 0);
1578 req
->out
.numargs
= 1;
1579 req
->out
.args
[0].size
= sizeof(outarg
);
1580 req
->out
.args
[0].value
= &outarg
;
1581 fuse_request_send(fc
, req
);
1582 err
= req
->out
.h
.error
;
1583 fuse_put_request(fc
, req
);
1585 err
= convert_fuse_file_lock(&outarg
.lk
, fl
);
1590 static int fuse_setlk(struct file
*file
, struct file_lock
*fl
, int flock
)
1592 struct inode
*inode
= file_inode(file
);
1593 struct fuse_conn
*fc
= get_fuse_conn(inode
);
1594 struct fuse_req
*req
;
1595 int opcode
= (fl
->fl_flags
& FL_SLEEP
) ? FUSE_SETLKW
: FUSE_SETLK
;
1596 pid_t pid
= fl
->fl_type
!= F_UNLCK
? current
->tgid
: 0;
1599 if (fl
->fl_lmops
&& fl
->fl_lmops
->lm_grant
) {
1600 /* NLM needs asynchronous locks, which we don't support yet */
1604 /* Unlock on close is handled by the flush method */
1605 if (fl
->fl_flags
& FL_CLOSE
)
1608 req
= fuse_get_req_nopages(fc
);
1610 return PTR_ERR(req
);
1612 fuse_lk_fill(req
, file
, fl
, opcode
, pid
, flock
);
1613 fuse_request_send(fc
, req
);
1614 err
= req
->out
.h
.error
;
1615 /* locking is restartable */
1618 fuse_put_request(fc
, req
);
1622 static int fuse_file_lock(struct file
*file
, int cmd
, struct file_lock
*fl
)
1624 struct inode
*inode
= file_inode(file
);
1625 struct fuse_conn
*fc
= get_fuse_conn(inode
);
1628 if (cmd
== F_CANCELLK
) {
1630 } else if (cmd
== F_GETLK
) {
1632 posix_test_lock(file
, fl
);
1635 err
= fuse_getlk(file
, fl
);
1638 err
= posix_lock_file(file
, fl
, NULL
);
1640 err
= fuse_setlk(file
, fl
, 0);
1645 static int fuse_file_flock(struct file
*file
, int cmd
, struct file_lock
*fl
)
1647 struct inode
*inode
= file_inode(file
);
1648 struct fuse_conn
*fc
= get_fuse_conn(inode
);
1652 err
= flock_lock_file_wait(file
, fl
);
1654 struct fuse_file
*ff
= file
->private_data
;
1656 /* emulate flock with POSIX locks */
1657 fl
->fl_owner
= (fl_owner_t
) file
;
1659 err
= fuse_setlk(file
, fl
, 1);
1665 static sector_t
fuse_bmap(struct address_space
*mapping
, sector_t block
)
1667 struct inode
*inode
= mapping
->host
;
1668 struct fuse_conn
*fc
= get_fuse_conn(inode
);
1669 struct fuse_req
*req
;
1670 struct fuse_bmap_in inarg
;
1671 struct fuse_bmap_out outarg
;
1674 if (!inode
->i_sb
->s_bdev
|| fc
->no_bmap
)
1677 req
= fuse_get_req_nopages(fc
);
1681 memset(&inarg
, 0, sizeof(inarg
));
1682 inarg
.block
= block
;
1683 inarg
.blocksize
= inode
->i_sb
->s_blocksize
;
1684 req
->in
.h
.opcode
= FUSE_BMAP
;
1685 req
->in
.h
.nodeid
= get_node_id(inode
);
1686 req
->in
.numargs
= 1;
1687 req
->in
.args
[0].size
= sizeof(inarg
);
1688 req
->in
.args
[0].value
= &inarg
;
1689 req
->out
.numargs
= 1;
1690 req
->out
.args
[0].size
= sizeof(outarg
);
1691 req
->out
.args
[0].value
= &outarg
;
1692 fuse_request_send(fc
, req
);
1693 err
= req
->out
.h
.error
;
1694 fuse_put_request(fc
, req
);
1698 return err
? 0 : outarg
.block
;
1701 static loff_t
fuse_file_llseek(struct file
*file
, loff_t offset
, int whence
)
1704 struct inode
*inode
= file_inode(file
);
1706 /* No i_mutex protection necessary for SEEK_CUR and SEEK_SET */
1707 if (whence
== SEEK_CUR
|| whence
== SEEK_SET
)
1708 return generic_file_llseek(file
, offset
, whence
);
1710 mutex_lock(&inode
->i_mutex
);
1711 retval
= fuse_update_attributes(inode
, NULL
, file
, NULL
);
1713 retval
= generic_file_llseek(file
, offset
, whence
);
1714 mutex_unlock(&inode
->i_mutex
);
1719 static int fuse_ioctl_copy_user(struct page
**pages
, struct iovec
*iov
,
1720 unsigned int nr_segs
, size_t bytes
, bool to_user
)
1728 iov_iter_init(&ii
, iov
, nr_segs
, bytes
, 0);
1730 while (iov_iter_count(&ii
)) {
1731 struct page
*page
= pages
[page_idx
++];
1732 size_t todo
= min_t(size_t, PAGE_SIZE
, iov_iter_count(&ii
));
1738 char __user
*uaddr
= ii
.iov
->iov_base
+ ii
.iov_offset
;
1739 size_t iov_len
= ii
.iov
->iov_len
- ii
.iov_offset
;
1740 size_t copy
= min(todo
, iov_len
);
1744 left
= copy_from_user(kaddr
, uaddr
, copy
);
1746 left
= copy_to_user(uaddr
, kaddr
, copy
);
1751 iov_iter_advance(&ii
, copy
);
1763 * CUSE servers compiled on 32bit broke on 64bit kernels because the
1764 * ABI was defined to be 'struct iovec' which is different on 32bit
1765 * and 64bit. Fortunately we can determine which structure the server
1766 * used from the size of the reply.
1768 static int fuse_copy_ioctl_iovec_old(struct iovec
*dst
, void *src
,
1769 size_t transferred
, unsigned count
,
1772 #ifdef CONFIG_COMPAT
1773 if (count
* sizeof(struct compat_iovec
) == transferred
) {
1774 struct compat_iovec
*ciov
= src
;
1778 * With this interface a 32bit server cannot support
1779 * non-compat (i.e. ones coming from 64bit apps) ioctl
1785 for (i
= 0; i
< count
; i
++) {
1786 dst
[i
].iov_base
= compat_ptr(ciov
[i
].iov_base
);
1787 dst
[i
].iov_len
= ciov
[i
].iov_len
;
1793 if (count
* sizeof(struct iovec
) != transferred
)
1796 memcpy(dst
, src
, transferred
);
1800 /* Make sure iov_length() won't overflow */
1801 static int fuse_verify_ioctl_iov(struct iovec
*iov
, size_t count
)
1804 u32 max
= FUSE_MAX_PAGES_PER_REQ
<< PAGE_SHIFT
;
1806 for (n
= 0; n
< count
; n
++, iov
++) {
1807 if (iov
->iov_len
> (size_t) max
)
1809 max
-= iov
->iov_len
;
1814 static int fuse_copy_ioctl_iovec(struct fuse_conn
*fc
, struct iovec
*dst
,
1815 void *src
, size_t transferred
, unsigned count
,
1819 struct fuse_ioctl_iovec
*fiov
= src
;
1821 if (fc
->minor
< 16) {
1822 return fuse_copy_ioctl_iovec_old(dst
, src
, transferred
,
1826 if (count
* sizeof(struct fuse_ioctl_iovec
) != transferred
)
1829 for (i
= 0; i
< count
; i
++) {
1830 /* Did the server supply an inappropriate value? */
1831 if (fiov
[i
].base
!= (unsigned long) fiov
[i
].base
||
1832 fiov
[i
].len
!= (unsigned long) fiov
[i
].len
)
1835 dst
[i
].iov_base
= (void __user
*) (unsigned long) fiov
[i
].base
;
1836 dst
[i
].iov_len
= (size_t) fiov
[i
].len
;
1838 #ifdef CONFIG_COMPAT
1840 (ptr_to_compat(dst
[i
].iov_base
) != fiov
[i
].base
||
1841 (compat_size_t
) dst
[i
].iov_len
!= fiov
[i
].len
))
1851 * For ioctls, there is no generic way to determine how much memory
1852 * needs to be read and/or written. Furthermore, ioctls are allowed
1853 * to dereference the passed pointer, so the parameter requires deep
1854 * copying but FUSE has no idea whatsoever about what to copy in or
1857 * This is solved by allowing FUSE server to retry ioctl with
1858 * necessary in/out iovecs. Let's assume the ioctl implementation
1859 * needs to read in the following structure.
1866 * On the first callout to FUSE server, inarg->in_size and
1867 * inarg->out_size will be NULL; then, the server completes the ioctl
1868 * with FUSE_IOCTL_RETRY set in out->flags, out->in_iovs set to 1 and
1869 * the actual iov array to
1871 * { { .iov_base = inarg.arg, .iov_len = sizeof(struct a) } }
1873 * which tells FUSE to copy in the requested area and retry the ioctl.
1874 * On the second round, the server has access to the structure and
1875 * from that it can tell what to look for next, so on the invocation,
1876 * it sets FUSE_IOCTL_RETRY, out->in_iovs to 2 and iov array to
1878 * { { .iov_base = inarg.arg, .iov_len = sizeof(struct a) },
1879 * { .iov_base = a.buf, .iov_len = a.buflen } }
1881 * FUSE will copy both struct a and the pointed buffer from the
1882 * process doing the ioctl and retry ioctl with both struct a and the
1885 * This time, FUSE server has everything it needs and completes ioctl
1886 * without FUSE_IOCTL_RETRY which finishes the ioctl call.
1888 * Copying data out works the same way.
1890 * Note that if FUSE_IOCTL_UNRESTRICTED is clear, the kernel
1891 * automatically initializes in and out iovs by decoding @cmd with
1892 * _IOC_* macros and the server is not allowed to request RETRY. This
1893 * limits ioctl data transfers to well-formed ioctls and is the forced
1894 * behavior for all FUSE servers.
1896 long fuse_do_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
,
1899 struct fuse_file
*ff
= file
->private_data
;
1900 struct fuse_conn
*fc
= ff
->fc
;
1901 struct fuse_ioctl_in inarg
= {
1907 struct fuse_ioctl_out outarg
;
1908 struct fuse_req
*req
= NULL
;
1909 struct page
**pages
= NULL
;
1910 struct iovec
*iov_page
= NULL
;
1911 struct iovec
*in_iov
= NULL
, *out_iov
= NULL
;
1912 unsigned int in_iovs
= 0, out_iovs
= 0, num_pages
= 0, max_pages
;
1913 size_t in_size
, out_size
, transferred
;
1916 #if BITS_PER_LONG == 32
1917 inarg
.flags
|= FUSE_IOCTL_32BIT
;
1919 if (flags
& FUSE_IOCTL_COMPAT
)
1920 inarg
.flags
|= FUSE_IOCTL_32BIT
;
1923 /* assume all the iovs returned by client always fits in a page */
1924 BUILD_BUG_ON(sizeof(struct fuse_ioctl_iovec
) * FUSE_IOCTL_MAX_IOV
> PAGE_SIZE
);
1927 pages
= kcalloc(FUSE_MAX_PAGES_PER_REQ
, sizeof(pages
[0]), GFP_KERNEL
);
1928 iov_page
= (struct iovec
*) __get_free_page(GFP_KERNEL
);
1929 if (!pages
|| !iov_page
)
1933 * If restricted, initialize IO parameters as encoded in @cmd.
1934 * RETRY from server is not allowed.
1936 if (!(flags
& FUSE_IOCTL_UNRESTRICTED
)) {
1937 struct iovec
*iov
= iov_page
;
1939 iov
->iov_base
= (void __user
*)arg
;
1940 iov
->iov_len
= _IOC_SIZE(cmd
);
1942 if (_IOC_DIR(cmd
) & _IOC_WRITE
) {
1947 if (_IOC_DIR(cmd
) & _IOC_READ
) {
1954 inarg
.in_size
= in_size
= iov_length(in_iov
, in_iovs
);
1955 inarg
.out_size
= out_size
= iov_length(out_iov
, out_iovs
);
1958 * Out data can be used either for actual out data or iovs,
1959 * make sure there always is at least one page.
1961 out_size
= max_t(size_t, out_size
, PAGE_SIZE
);
1962 max_pages
= DIV_ROUND_UP(max(in_size
, out_size
), PAGE_SIZE
);
1964 /* make sure there are enough buffer pages and init request with them */
1966 if (max_pages
> FUSE_MAX_PAGES_PER_REQ
)
1968 while (num_pages
< max_pages
) {
1969 pages
[num_pages
] = alloc_page(GFP_KERNEL
| __GFP_HIGHMEM
);
1970 if (!pages
[num_pages
])
1975 req
= fuse_get_req(fc
, num_pages
);
1981 memcpy(req
->pages
, pages
, sizeof(req
->pages
[0]) * num_pages
);
1982 req
->num_pages
= num_pages
;
1983 fuse_page_descs_length_init(req
, 0, req
->num_pages
);
1985 /* okay, let's send it to the client */
1986 req
->in
.h
.opcode
= FUSE_IOCTL
;
1987 req
->in
.h
.nodeid
= ff
->nodeid
;
1988 req
->in
.numargs
= 1;
1989 req
->in
.args
[0].size
= sizeof(inarg
);
1990 req
->in
.args
[0].value
= &inarg
;
1993 req
->in
.args
[1].size
= in_size
;
1994 req
->in
.argpages
= 1;
1996 err
= fuse_ioctl_copy_user(pages
, in_iov
, in_iovs
, in_size
,
2002 req
->out
.numargs
= 2;
2003 req
->out
.args
[0].size
= sizeof(outarg
);
2004 req
->out
.args
[0].value
= &outarg
;
2005 req
->out
.args
[1].size
= out_size
;
2006 req
->out
.argpages
= 1;
2007 req
->out
.argvar
= 1;
2009 fuse_request_send(fc
, req
);
2010 err
= req
->out
.h
.error
;
2011 transferred
= req
->out
.args
[1].size
;
2012 fuse_put_request(fc
, req
);
2017 /* did it ask for retry? */
2018 if (outarg
.flags
& FUSE_IOCTL_RETRY
) {
2021 /* no retry if in restricted mode */
2023 if (!(flags
& FUSE_IOCTL_UNRESTRICTED
))
2026 in_iovs
= outarg
.in_iovs
;
2027 out_iovs
= outarg
.out_iovs
;
2030 * Make sure things are in boundary, separate checks
2031 * are to protect against overflow.
2034 if (in_iovs
> FUSE_IOCTL_MAX_IOV
||
2035 out_iovs
> FUSE_IOCTL_MAX_IOV
||
2036 in_iovs
+ out_iovs
> FUSE_IOCTL_MAX_IOV
)
2039 vaddr
= kmap_atomic(pages
[0]);
2040 err
= fuse_copy_ioctl_iovec(fc
, iov_page
, vaddr
,
2041 transferred
, in_iovs
+ out_iovs
,
2042 (flags
& FUSE_IOCTL_COMPAT
) != 0);
2043 kunmap_atomic(vaddr
);
2048 out_iov
= in_iov
+ in_iovs
;
2050 err
= fuse_verify_ioctl_iov(in_iov
, in_iovs
);
2054 err
= fuse_verify_ioctl_iov(out_iov
, out_iovs
);
2062 if (transferred
> inarg
.out_size
)
2065 err
= fuse_ioctl_copy_user(pages
, out_iov
, out_iovs
, transferred
, true);
2068 fuse_put_request(fc
, req
);
2069 free_page((unsigned long) iov_page
);
2071 __free_page(pages
[--num_pages
]);
2074 return err
? err
: outarg
.result
;
2076 EXPORT_SYMBOL_GPL(fuse_do_ioctl
);
2078 long fuse_ioctl_common(struct file
*file
, unsigned int cmd
,
2079 unsigned long arg
, unsigned int flags
)
2081 struct inode
*inode
= file_inode(file
);
2082 struct fuse_conn
*fc
= get_fuse_conn(inode
);
2084 if (!fuse_allow_current_process(fc
))
2087 if (is_bad_inode(inode
))
2090 return fuse_do_ioctl(file
, cmd
, arg
, flags
);
2093 static long fuse_file_ioctl(struct file
*file
, unsigned int cmd
,
2096 return fuse_ioctl_common(file
, cmd
, arg
, 0);
2099 static long fuse_file_compat_ioctl(struct file
*file
, unsigned int cmd
,
2102 return fuse_ioctl_common(file
, cmd
, arg
, FUSE_IOCTL_COMPAT
);
2106 * All files which have been polled are linked to RB tree
2107 * fuse_conn->polled_files which is indexed by kh. Walk the tree and
2108 * find the matching one.
2110 static struct rb_node
**fuse_find_polled_node(struct fuse_conn
*fc
, u64 kh
,
2111 struct rb_node
**parent_out
)
2113 struct rb_node
**link
= &fc
->polled_files
.rb_node
;
2114 struct rb_node
*last
= NULL
;
2117 struct fuse_file
*ff
;
2120 ff
= rb_entry(last
, struct fuse_file
, polled_node
);
2123 link
= &last
->rb_left
;
2124 else if (kh
> ff
->kh
)
2125 link
= &last
->rb_right
;
2136 * The file is about to be polled. Make sure it's on the polled_files
2137 * RB tree. Note that files once added to the polled_files tree are
2138 * not removed before the file is released. This is because a file
2139 * polled once is likely to be polled again.
2141 static void fuse_register_polled_file(struct fuse_conn
*fc
,
2142 struct fuse_file
*ff
)
2144 spin_lock(&fc
->lock
);
2145 if (RB_EMPTY_NODE(&ff
->polled_node
)) {
2146 struct rb_node
**link
, *parent
;
2148 link
= fuse_find_polled_node(fc
, ff
->kh
, &parent
);
2150 rb_link_node(&ff
->polled_node
, parent
, link
);
2151 rb_insert_color(&ff
->polled_node
, &fc
->polled_files
);
2153 spin_unlock(&fc
->lock
);
2156 unsigned fuse_file_poll(struct file
*file
, poll_table
*wait
)
2158 struct fuse_file
*ff
= file
->private_data
;
2159 struct fuse_conn
*fc
= ff
->fc
;
2160 struct fuse_poll_in inarg
= { .fh
= ff
->fh
, .kh
= ff
->kh
};
2161 struct fuse_poll_out outarg
;
2162 struct fuse_req
*req
;
2166 return DEFAULT_POLLMASK
;
2168 poll_wait(file
, &ff
->poll_wait
, wait
);
2169 inarg
.events
= (__u32
)poll_requested_events(wait
);
2172 * Ask for notification iff there's someone waiting for it.
2173 * The client may ignore the flag and always notify.
2175 if (waitqueue_active(&ff
->poll_wait
)) {
2176 inarg
.flags
|= FUSE_POLL_SCHEDULE_NOTIFY
;
2177 fuse_register_polled_file(fc
, ff
);
2180 req
= fuse_get_req_nopages(fc
);
2184 req
->in
.h
.opcode
= FUSE_POLL
;
2185 req
->in
.h
.nodeid
= ff
->nodeid
;
2186 req
->in
.numargs
= 1;
2187 req
->in
.args
[0].size
= sizeof(inarg
);
2188 req
->in
.args
[0].value
= &inarg
;
2189 req
->out
.numargs
= 1;
2190 req
->out
.args
[0].size
= sizeof(outarg
);
2191 req
->out
.args
[0].value
= &outarg
;
2192 fuse_request_send(fc
, req
);
2193 err
= req
->out
.h
.error
;
2194 fuse_put_request(fc
, req
);
2197 return outarg
.revents
;
2198 if (err
== -ENOSYS
) {
2200 return DEFAULT_POLLMASK
;
2204 EXPORT_SYMBOL_GPL(fuse_file_poll
);
2207 * This is called from fuse_handle_notify() on FUSE_NOTIFY_POLL and
2208 * wakes up the poll waiters.
2210 int fuse_notify_poll_wakeup(struct fuse_conn
*fc
,
2211 struct fuse_notify_poll_wakeup_out
*outarg
)
2213 u64 kh
= outarg
->kh
;
2214 struct rb_node
**link
;
2216 spin_lock(&fc
->lock
);
2218 link
= fuse_find_polled_node(fc
, kh
, NULL
);
2220 struct fuse_file
*ff
;
2222 ff
= rb_entry(*link
, struct fuse_file
, polled_node
);
2223 wake_up_interruptible_sync(&ff
->poll_wait
);
2226 spin_unlock(&fc
->lock
);
2231 fuse_direct_IO(int rw
, struct kiocb
*iocb
, const struct iovec
*iov
,
2232 loff_t offset
, unsigned long nr_segs
)
2235 struct file
*file
= NULL
;
2238 file
= iocb
->ki_filp
;
2242 ret
= __fuse_direct_write(file
, iov
, nr_segs
, &pos
);
2244 ret
= __fuse_direct_read(file
, iov
, nr_segs
, &pos
);
2249 static long fuse_file_fallocate(struct file
*file
, int mode
, loff_t offset
,
2252 struct fuse_file
*ff
= file
->private_data
;
2253 struct fuse_conn
*fc
= ff
->fc
;
2254 struct fuse_req
*req
;
2255 struct fuse_fallocate_in inarg
= {
2263 if (fc
->no_fallocate
)
2266 req
= fuse_get_req_nopages(fc
);
2268 return PTR_ERR(req
);
2270 req
->in
.h
.opcode
= FUSE_FALLOCATE
;
2271 req
->in
.h
.nodeid
= ff
->nodeid
;
2272 req
->in
.numargs
= 1;
2273 req
->in
.args
[0].size
= sizeof(inarg
);
2274 req
->in
.args
[0].value
= &inarg
;
2275 fuse_request_send(fc
, req
);
2276 err
= req
->out
.h
.error
;
2277 if (err
== -ENOSYS
) {
2278 fc
->no_fallocate
= 1;
2281 fuse_put_request(fc
, req
);
2286 static const struct file_operations fuse_file_operations
= {
2287 .llseek
= fuse_file_llseek
,
2288 .read
= do_sync_read
,
2289 .aio_read
= fuse_file_aio_read
,
2290 .write
= do_sync_write
,
2291 .aio_write
= fuse_file_aio_write
,
2292 .mmap
= fuse_file_mmap
,
2294 .flush
= fuse_flush
,
2295 .release
= fuse_release
,
2296 .fsync
= fuse_fsync
,
2297 .lock
= fuse_file_lock
,
2298 .flock
= fuse_file_flock
,
2299 .splice_read
= generic_file_splice_read
,
2300 .unlocked_ioctl
= fuse_file_ioctl
,
2301 .compat_ioctl
= fuse_file_compat_ioctl
,
2302 .poll
= fuse_file_poll
,
2303 .fallocate
= fuse_file_fallocate
,
2306 static const struct file_operations fuse_direct_io_file_operations
= {
2307 .llseek
= fuse_file_llseek
,
2308 .read
= fuse_direct_read
,
2309 .write
= fuse_direct_write
,
2310 .mmap
= fuse_direct_mmap
,
2312 .flush
= fuse_flush
,
2313 .release
= fuse_release
,
2314 .fsync
= fuse_fsync
,
2315 .lock
= fuse_file_lock
,
2316 .flock
= fuse_file_flock
,
2317 .unlocked_ioctl
= fuse_file_ioctl
,
2318 .compat_ioctl
= fuse_file_compat_ioctl
,
2319 .poll
= fuse_file_poll
,
2320 .fallocate
= fuse_file_fallocate
,
2321 /* no splice_read */
2324 static const struct address_space_operations fuse_file_aops
= {
2325 .readpage
= fuse_readpage
,
2326 .writepage
= fuse_writepage
,
2327 .launder_page
= fuse_launder_page
,
2328 .readpages
= fuse_readpages
,
2329 .set_page_dirty
= __set_page_dirty_nobuffers
,
2331 .direct_IO
= fuse_direct_IO
,
2334 void fuse_init_file_inode(struct inode
*inode
)
2336 inode
->i_fop
= &fuse_file_operations
;
2337 inode
->i_data
.a_ops
= &fuse_file_aops
;