1 // SPDX-License-Identifier: GPL-2.0-only
3 * linux/fs/9p/vfs_file.c
5 * This file contians vfs file ops for 9P2000.
7 * Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
8 * Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
11 #include <linux/module.h>
12 #include <linux/errno.h>
14 #include <linux/sched.h>
15 #include <linux/file.h>
16 #include <linux/stat.h>
17 #include <linux/string.h>
18 #include <linux/inet.h>
19 #include <linux/list.h>
20 #include <linux/pagemap.h>
21 #include <linux/utsname.h>
22 #include <linux/uaccess.h>
23 #include <linux/idr.h>
24 #include <linux/uio.h>
25 #include <linux/slab.h>
26 #include <net/9p/9p.h>
27 #include <net/9p/client.h>
34 static const struct vm_operations_struct v9fs_file_vm_ops
;
35 static const struct vm_operations_struct v9fs_mmap_file_vm_ops
;
38 * v9fs_file_open - open a file (or directory)
39 * @inode: inode to be opened
40 * @file: file being opened
44 int v9fs_file_open(struct inode
*inode
, struct file
*file
)
47 struct v9fs_inode
*v9inode
;
48 struct v9fs_session_info
*v9ses
;
49 struct p9_fid
*fid
, *writeback_fid
;
52 p9_debug(P9_DEBUG_VFS
, "inode: %p file: %p\n", inode
, file
);
53 v9inode
= V9FS_I(inode
);
54 v9ses
= v9fs_inode2v9ses(inode
);
55 if (v9fs_proto_dotl(v9ses
))
56 omode
= v9fs_open_to_dotl_flags(file
->f_flags
);
58 omode
= v9fs_uflags2omode(file
->f_flags
,
59 v9fs_proto_dotu(v9ses
));
60 fid
= file
->private_data
;
62 fid
= v9fs_fid_clone(file_dentry(file
));
66 err
= p9_client_open(fid
, omode
);
71 if ((file
->f_flags
& O_APPEND
) &&
72 (!v9fs_proto_dotu(v9ses
) && !v9fs_proto_dotl(v9ses
)))
73 generic_file_llseek(file
, 0, SEEK_END
);
76 file
->private_data
= fid
;
77 mutex_lock(&v9inode
->v_mutex
);
78 if ((v9ses
->cache
== CACHE_LOOSE
|| v9ses
->cache
== CACHE_FSCACHE
) &&
79 !v9inode
->writeback_fid
&&
80 ((file
->f_flags
& O_ACCMODE
) != O_RDONLY
)) {
82 * clone a fid and add it to writeback_fid
83 * we do it during open time instead of
84 * page dirty time via write_begin/page_mkwrite
85 * because we want write after unlink usecase
88 writeback_fid
= v9fs_writeback_fid(file_dentry(file
));
91 mutex_unlock(&v9inode
->v_mutex
);
94 v9inode
->writeback_fid
= (void *) writeback_fid
;
96 mutex_unlock(&v9inode
->v_mutex
);
97 if (v9ses
->cache
== CACHE_LOOSE
|| v9ses
->cache
== CACHE_FSCACHE
)
98 v9fs_cache_inode_set_cookie(inode
, file
);
99 v9fs_open_fid_add(inode
, fid
);
102 p9_client_clunk(file
->private_data
);
103 file
->private_data
= NULL
;
108 * v9fs_file_lock - lock a file (or directory)
109 * @filp: file to be locked
111 * @fl: file lock structure
113 * Bugs: this looks like a local only lock, we should extend into 9P
114 * by using open exclusive
117 static int v9fs_file_lock(struct file
*filp
, int cmd
, struct file_lock
*fl
)
120 struct inode
*inode
= file_inode(filp
);
122 p9_debug(P9_DEBUG_VFS
, "filp: %p lock: %p\n", filp
, fl
);
124 /* No mandatory locks */
125 if (__mandatory_lock(inode
) && fl
->fl_type
!= F_UNLCK
)
128 if ((IS_SETLK(cmd
) || IS_SETLKW(cmd
)) && fl
->fl_type
!= F_UNLCK
) {
129 filemap_write_and_wait(inode
->i_mapping
);
130 invalidate_mapping_pages(&inode
->i_data
, 0, -1);
136 static int v9fs_file_do_lock(struct file
*filp
, int cmd
, struct file_lock
*fl
)
138 struct p9_flock flock
;
140 uint8_t status
= P9_LOCK_ERROR
;
142 unsigned char fl_type
;
143 struct v9fs_session_info
*v9ses
;
145 fid
= filp
->private_data
;
148 if ((fl
->fl_flags
& FL_POSIX
) != FL_POSIX
)
151 res
= locks_lock_file_wait(filp
, fl
);
155 /* convert posix lock to p9 tlock args */
156 memset(&flock
, 0, sizeof(flock
));
157 /* map the lock type */
158 switch (fl
->fl_type
) {
160 flock
.type
= P9_LOCK_TYPE_RDLCK
;
163 flock
.type
= P9_LOCK_TYPE_WRLCK
;
166 flock
.type
= P9_LOCK_TYPE_UNLCK
;
169 flock
.start
= fl
->fl_start
;
170 if (fl
->fl_end
== OFFSET_MAX
)
173 flock
.length
= fl
->fl_end
- fl
->fl_start
+ 1;
174 flock
.proc_id
= fl
->fl_pid
;
175 flock
.client_id
= fid
->clnt
->name
;
177 flock
.flags
= P9_LOCK_FLAGS_BLOCK
;
179 v9ses
= v9fs_inode2v9ses(file_inode(filp
));
182 * if its a blocked request and we get P9_LOCK_BLOCKED as the status
183 * for lock request, keep on trying
186 res
= p9_client_lock_dotl(fid
, &flock
, &status
);
190 if (status
!= P9_LOCK_BLOCKED
)
192 if (status
== P9_LOCK_BLOCKED
&& !IS_SETLKW(cmd
))
194 if (schedule_timeout_interruptible(v9ses
->session_lock_timeout
)
198 * p9_client_lock_dotl overwrites flock.client_id with the
199 * server message, free and reuse the client name
201 if (flock
.client_id
!= fid
->clnt
->name
) {
202 kfree(flock
.client_id
);
203 flock
.client_id
= fid
->clnt
->name
;
207 /* map 9p status to VFS status */
209 case P9_LOCK_SUCCESS
:
212 case P9_LOCK_BLOCKED
:
216 WARN_ONCE(1, "unknown lock status code: %d\n", status
);
226 * incase server returned error for lock request, revert
229 if (res
< 0 && fl
->fl_type
!= F_UNLCK
) {
230 fl_type
= fl
->fl_type
;
231 fl
->fl_type
= F_UNLCK
;
232 /* Even if this fails we want to return the remote error */
233 locks_lock_file_wait(filp
, fl
);
234 fl
->fl_type
= fl_type
;
236 if (flock
.client_id
!= fid
->clnt
->name
)
237 kfree(flock
.client_id
);
242 static int v9fs_file_getlock(struct file
*filp
, struct file_lock
*fl
)
244 struct p9_getlock glock
;
248 fid
= filp
->private_data
;
251 posix_test_lock(filp
, fl
);
253 * if we have a conflicting lock locally, no need to validate
256 if (fl
->fl_type
!= F_UNLCK
)
259 /* convert posix lock to p9 tgetlock args */
260 memset(&glock
, 0, sizeof(glock
));
261 glock
.type
= P9_LOCK_TYPE_UNLCK
;
262 glock
.start
= fl
->fl_start
;
263 if (fl
->fl_end
== OFFSET_MAX
)
266 glock
.length
= fl
->fl_end
- fl
->fl_start
+ 1;
267 glock
.proc_id
= fl
->fl_pid
;
268 glock
.client_id
= fid
->clnt
->name
;
270 res
= p9_client_getlock_dotl(fid
, &glock
);
273 /* map 9p lock type to os lock type */
274 switch (glock
.type
) {
275 case P9_LOCK_TYPE_RDLCK
:
276 fl
->fl_type
= F_RDLCK
;
278 case P9_LOCK_TYPE_WRLCK
:
279 fl
->fl_type
= F_WRLCK
;
281 case P9_LOCK_TYPE_UNLCK
:
282 fl
->fl_type
= F_UNLCK
;
285 if (glock
.type
!= P9_LOCK_TYPE_UNLCK
) {
286 fl
->fl_start
= glock
.start
;
287 if (glock
.length
== 0)
288 fl
->fl_end
= OFFSET_MAX
;
290 fl
->fl_end
= glock
.start
+ glock
.length
- 1;
291 fl
->fl_pid
= -glock
.proc_id
;
294 if (glock
.client_id
!= fid
->clnt
->name
)
295 kfree(glock
.client_id
);
300 * v9fs_file_lock_dotl - lock a file (or directory)
301 * @filp: file to be locked
303 * @fl: file lock structure
307 static int v9fs_file_lock_dotl(struct file
*filp
, int cmd
, struct file_lock
*fl
)
309 struct inode
*inode
= file_inode(filp
);
312 p9_debug(P9_DEBUG_VFS
, "filp: %p cmd:%d lock: %p name: %pD\n",
313 filp
, cmd
, fl
, filp
);
315 /* No mandatory locks */
316 if (__mandatory_lock(inode
) && fl
->fl_type
!= F_UNLCK
)
319 if ((IS_SETLK(cmd
) || IS_SETLKW(cmd
)) && fl
->fl_type
!= F_UNLCK
) {
320 filemap_write_and_wait(inode
->i_mapping
);
321 invalidate_mapping_pages(&inode
->i_data
, 0, -1);
324 if (IS_SETLK(cmd
) || IS_SETLKW(cmd
))
325 ret
= v9fs_file_do_lock(filp
, cmd
, fl
);
326 else if (IS_GETLK(cmd
))
327 ret
= v9fs_file_getlock(filp
, fl
);
335 * v9fs_file_flock_dotl - lock a file
336 * @filp: file to be locked
338 * @fl: file lock structure
342 static int v9fs_file_flock_dotl(struct file
*filp
, int cmd
,
343 struct file_lock
*fl
)
345 struct inode
*inode
= file_inode(filp
);
348 p9_debug(P9_DEBUG_VFS
, "filp: %p cmd:%d lock: %p name: %pD\n",
349 filp
, cmd
, fl
, filp
);
351 /* No mandatory locks */
352 if (__mandatory_lock(inode
) && fl
->fl_type
!= F_UNLCK
)
355 if (!(fl
->fl_flags
& FL_FLOCK
))
358 if ((IS_SETLK(cmd
) || IS_SETLKW(cmd
)) && fl
->fl_type
!= F_UNLCK
) {
359 filemap_write_and_wait(inode
->i_mapping
);
360 invalidate_mapping_pages(&inode
->i_data
, 0, -1);
362 /* Convert flock to posix lock */
363 fl
->fl_flags
|= FL_POSIX
;
364 fl
->fl_flags
^= FL_FLOCK
;
366 if (IS_SETLK(cmd
) | IS_SETLKW(cmd
))
367 ret
= v9fs_file_do_lock(filp
, cmd
, fl
);
375 * v9fs_file_read - read from a file
376 * @filp: file pointer to read
377 * @udata: user data buffer to read data into
378 * @count: size of buffer
379 * @offset: offset at which to read data
384 v9fs_file_read_iter(struct kiocb
*iocb
, struct iov_iter
*to
)
386 struct p9_fid
*fid
= iocb
->ki_filp
->private_data
;
389 p9_debug(P9_DEBUG_VFS
, "count %zu offset %lld\n",
390 iov_iter_count(to
), iocb
->ki_pos
);
392 if (iocb
->ki_filp
->f_flags
& O_NONBLOCK
)
393 ret
= p9_client_read_once(fid
, iocb
->ki_pos
, to
, &err
);
395 ret
= p9_client_read(fid
, iocb
->ki_pos
, to
, &err
);
404 * v9fs_file_write - write to a file
405 * @filp: file pointer to write
406 * @data: data buffer to write data from
407 * @count: size of buffer
408 * @offset: offset at which to write data
412 v9fs_file_write_iter(struct kiocb
*iocb
, struct iov_iter
*from
)
414 struct file
*file
= iocb
->ki_filp
;
419 retval
= generic_write_checks(iocb
, from
);
423 origin
= iocb
->ki_pos
;
424 retval
= p9_client_write(file
->private_data
, iocb
->ki_pos
, from
, &err
);
426 struct inode
*inode
= file_inode(file
);
428 unsigned long pg_start
, pg_end
;
429 pg_start
= origin
>> PAGE_SHIFT
;
430 pg_end
= (origin
+ retval
- 1) >> PAGE_SHIFT
;
431 if (inode
->i_mapping
&& inode
->i_mapping
->nrpages
)
432 invalidate_inode_pages2_range(inode
->i_mapping
,
434 iocb
->ki_pos
+= retval
;
435 i_size
= i_size_read(inode
);
436 if (iocb
->ki_pos
> i_size
) {
437 inode_add_bytes(inode
, iocb
->ki_pos
- i_size
);
439 * Need to serialize against i_size_write() in
442 v9fs_i_size_write(inode
, iocb
->ki_pos
);
449 static int v9fs_file_fsync(struct file
*filp
, loff_t start
, loff_t end
,
453 struct inode
*inode
= filp
->f_mapping
->host
;
454 struct p9_wstat wstat
;
457 retval
= file_write_and_wait_range(filp
, start
, end
);
462 p9_debug(P9_DEBUG_VFS
, "filp %p datasync %x\n", filp
, datasync
);
464 fid
= filp
->private_data
;
465 v9fs_blank_wstat(&wstat
);
467 retval
= p9_client_wstat(fid
, &wstat
);
473 int v9fs_file_fsync_dotl(struct file
*filp
, loff_t start
, loff_t end
,
477 struct inode
*inode
= filp
->f_mapping
->host
;
480 retval
= file_write_and_wait_range(filp
, start
, end
);
485 p9_debug(P9_DEBUG_VFS
, "filp %p datasync %x\n", filp
, datasync
);
487 fid
= filp
->private_data
;
489 retval
= p9_client_fsync(fid
, datasync
);
496 v9fs_file_mmap(struct file
*filp
, struct vm_area_struct
*vma
)
501 retval
= generic_file_mmap(filp
, vma
);
503 vma
->vm_ops
= &v9fs_file_vm_ops
;
509 v9fs_mmap_file_mmap(struct file
*filp
, struct vm_area_struct
*vma
)
513 struct v9fs_inode
*v9inode
;
516 inode
= file_inode(filp
);
517 v9inode
= V9FS_I(inode
);
518 mutex_lock(&v9inode
->v_mutex
);
519 if (!v9inode
->writeback_fid
&&
520 (vma
->vm_flags
& VM_SHARED
) &&
521 (vma
->vm_flags
& VM_WRITE
)) {
523 * clone a fid and add it to writeback_fid
524 * we do it during mmap instead of
525 * page dirty time via write_begin/page_mkwrite
526 * because we want write after unlink usecase
529 fid
= v9fs_writeback_fid(file_dentry(filp
));
531 retval
= PTR_ERR(fid
);
532 mutex_unlock(&v9inode
->v_mutex
);
535 v9inode
->writeback_fid
= (void *) fid
;
537 mutex_unlock(&v9inode
->v_mutex
);
539 retval
= generic_file_mmap(filp
, vma
);
541 vma
->vm_ops
= &v9fs_mmap_file_vm_ops
;
547 v9fs_vm_page_mkwrite(struct vm_fault
*vmf
)
549 struct v9fs_inode
*v9inode
;
550 struct page
*page
= vmf
->page
;
551 struct file
*filp
= vmf
->vma
->vm_file
;
552 struct inode
*inode
= file_inode(filp
);
555 p9_debug(P9_DEBUG_VFS
, "page %p fid %lx\n",
556 page
, (unsigned long)filp
->private_data
);
558 /* Update file times before taking page lock */
559 file_update_time(filp
);
561 v9inode
= V9FS_I(inode
);
562 /* make sure the cache has finished storing the page */
563 v9fs_fscache_wait_on_page_write(inode
, page
);
564 BUG_ON(!v9inode
->writeback_fid
);
566 if (page
->mapping
!= inode
->i_mapping
)
568 wait_for_stable_page(page
);
570 return VM_FAULT_LOCKED
;
573 return VM_FAULT_NOPAGE
;
577 * v9fs_mmap_file_read - read from a file
578 * @filp: file pointer to read
579 * @data: user data buffer to read data into
580 * @count: size of buffer
581 * @offset: offset at which to read data
585 v9fs_mmap_file_read_iter(struct kiocb
*iocb
, struct iov_iter
*to
)
587 /* TODO: Check if there are dirty pages */
588 return v9fs_file_read_iter(iocb
, to
);
592 * v9fs_mmap_file_write - write to a file
593 * @filp: file pointer to write
594 * @data: data buffer to write data from
595 * @count: size of buffer
596 * @offset: offset at which to write data
600 v9fs_mmap_file_write_iter(struct kiocb
*iocb
, struct iov_iter
*from
)
603 * TODO: invalidate mmaps on filp's inode between
604 * offset and offset+count
606 return v9fs_file_write_iter(iocb
, from
);
609 static void v9fs_mmap_vm_close(struct vm_area_struct
*vma
)
613 struct writeback_control wbc
= {
614 .nr_to_write
= LONG_MAX
,
615 .sync_mode
= WB_SYNC_ALL
,
616 .range_start
= (loff_t
)vma
->vm_pgoff
* PAGE_SIZE
,
617 /* absolute end, byte at end included */
618 .range_end
= (loff_t
)vma
->vm_pgoff
* PAGE_SIZE
+
619 (vma
->vm_end
- vma
->vm_start
- 1),
622 if (!(vma
->vm_flags
& VM_SHARED
))
625 p9_debug(P9_DEBUG_VFS
, "9p VMA close, %p, flushing", vma
);
627 inode
= file_inode(vma
->vm_file
);
629 if (!mapping_can_writeback(inode
->i_mapping
))
633 sync_inode(inode
, &wbc
);
637 static const struct vm_operations_struct v9fs_file_vm_ops
= {
638 .fault
= filemap_fault
,
639 .map_pages
= filemap_map_pages
,
640 .page_mkwrite
= v9fs_vm_page_mkwrite
,
643 static const struct vm_operations_struct v9fs_mmap_file_vm_ops
= {
644 .close
= v9fs_mmap_vm_close
,
645 .fault
= filemap_fault
,
646 .map_pages
= filemap_map_pages
,
647 .page_mkwrite
= v9fs_vm_page_mkwrite
,
651 const struct file_operations v9fs_cached_file_operations
= {
652 .llseek
= generic_file_llseek
,
653 .read_iter
= generic_file_read_iter
,
654 .write_iter
= generic_file_write_iter
,
655 .open
= v9fs_file_open
,
656 .release
= v9fs_dir_release
,
657 .lock
= v9fs_file_lock
,
658 .mmap
= v9fs_file_mmap
,
659 .splice_read
= generic_file_splice_read
,
660 .splice_write
= iter_file_splice_write
,
661 .fsync
= v9fs_file_fsync
,
664 const struct file_operations v9fs_cached_file_operations_dotl
= {
665 .llseek
= generic_file_llseek
,
666 .read_iter
= generic_file_read_iter
,
667 .write_iter
= generic_file_write_iter
,
668 .open
= v9fs_file_open
,
669 .release
= v9fs_dir_release
,
670 .lock
= v9fs_file_lock_dotl
,
671 .flock
= v9fs_file_flock_dotl
,
672 .mmap
= v9fs_file_mmap
,
673 .splice_read
= generic_file_splice_read
,
674 .splice_write
= iter_file_splice_write
,
675 .fsync
= v9fs_file_fsync_dotl
,
678 const struct file_operations v9fs_file_operations
= {
679 .llseek
= generic_file_llseek
,
680 .read_iter
= v9fs_file_read_iter
,
681 .write_iter
= v9fs_file_write_iter
,
682 .open
= v9fs_file_open
,
683 .release
= v9fs_dir_release
,
684 .lock
= v9fs_file_lock
,
685 .mmap
= generic_file_readonly_mmap
,
686 .splice_read
= generic_file_splice_read
,
687 .splice_write
= iter_file_splice_write
,
688 .fsync
= v9fs_file_fsync
,
691 const struct file_operations v9fs_file_operations_dotl
= {
692 .llseek
= generic_file_llseek
,
693 .read_iter
= v9fs_file_read_iter
,
694 .write_iter
= v9fs_file_write_iter
,
695 .open
= v9fs_file_open
,
696 .release
= v9fs_dir_release
,
697 .lock
= v9fs_file_lock_dotl
,
698 .flock
= v9fs_file_flock_dotl
,
699 .mmap
= generic_file_readonly_mmap
,
700 .splice_read
= generic_file_splice_read
,
701 .splice_write
= iter_file_splice_write
,
702 .fsync
= v9fs_file_fsync_dotl
,
705 const struct file_operations v9fs_mmap_file_operations
= {
706 .llseek
= generic_file_llseek
,
707 .read_iter
= v9fs_mmap_file_read_iter
,
708 .write_iter
= v9fs_mmap_file_write_iter
,
709 .open
= v9fs_file_open
,
710 .release
= v9fs_dir_release
,
711 .lock
= v9fs_file_lock
,
712 .mmap
= v9fs_mmap_file_mmap
,
713 .splice_read
= generic_file_splice_read
,
714 .splice_write
= iter_file_splice_write
,
715 .fsync
= v9fs_file_fsync
,
718 const struct file_operations v9fs_mmap_file_operations_dotl
= {
719 .llseek
= generic_file_llseek
,
720 .read_iter
= v9fs_mmap_file_read_iter
,
721 .write_iter
= v9fs_mmap_file_write_iter
,
722 .open
= v9fs_file_open
,
723 .release
= v9fs_dir_release
,
724 .lock
= v9fs_file_lock_dotl
,
725 .flock
= v9fs_file_flock_dotl
,
726 .mmap
= v9fs_mmap_file_mmap
,
727 .splice_read
= generic_file_splice_read
,
728 .splice_write
= iter_file_splice_write
,
729 .fsync
= v9fs_file_fsync_dotl
,