xref: /openbmc/linux/fs/9p/vfs_file.c (revision 95e9fd10)
1 /*
2  *  linux/fs/9p/vfs_file.c
3  *
4  * This file contians vfs file ops for 9P2000.
5  *
6  *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
7  *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
8  *
9  *  This program is free software; you can redistribute it and/or modify
10  *  it under the terms of the GNU General Public License version 2
11  *  as published by the Free Software Foundation.
12  *
13  *  This program is distributed in the hope that it will be useful,
14  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  *  GNU General Public License for more details.
17  *
18  *  You should have received a copy of the GNU General Public License
19  *  along with this program; if not, write to:
20  *  Free Software Foundation
21  *  51 Franklin Street, Fifth Floor
22  *  Boston, MA  02111-1301  USA
23  *
24  */
25 
26 #include <linux/module.h>
27 #include <linux/errno.h>
28 #include <linux/fs.h>
29 #include <linux/sched.h>
30 #include <linux/file.h>
31 #include <linux/stat.h>
32 #include <linux/string.h>
33 #include <linux/inet.h>
34 #include <linux/list.h>
35 #include <linux/pagemap.h>
36 #include <linux/utsname.h>
37 #include <asm/uaccess.h>
38 #include <linux/idr.h>
39 #include <net/9p/9p.h>
40 #include <net/9p/client.h>
41 
42 #include "v9fs.h"
43 #include "v9fs_vfs.h"
44 #include "fid.h"
45 #include "cache.h"
46 
47 static const struct vm_operations_struct v9fs_file_vm_ops;
48 
49 /**
50  * v9fs_file_open - open a file (or directory)
51  * @inode: inode to be opened
52  * @file: file being opened
53  *
54  */
55 
56 int v9fs_file_open(struct inode *inode, struct file *file)
57 {
58 	int err;
59 	struct v9fs_inode *v9inode;
60 	struct v9fs_session_info *v9ses;
61 	struct p9_fid *fid;
62 	int omode;
63 
64 	p9_debug(P9_DEBUG_VFS, "inode: %p file: %p\n", inode, file);
65 	v9inode = V9FS_I(inode);
66 	v9ses = v9fs_inode2v9ses(inode);
67 	if (v9fs_proto_dotl(v9ses))
68 		omode = v9fs_open_to_dotl_flags(file->f_flags);
69 	else
70 		omode = v9fs_uflags2omode(file->f_flags,
71 					v9fs_proto_dotu(v9ses));
72 	fid = file->private_data;
73 	if (!fid) {
74 		fid = v9fs_fid_clone(file->f_path.dentry);
75 		if (IS_ERR(fid))
76 			return PTR_ERR(fid);
77 
78 		err = p9_client_open(fid, omode);
79 		if (err < 0) {
80 			p9_client_clunk(fid);
81 			return err;
82 		}
83 		if (file->f_flags & O_TRUNC) {
84 			i_size_write(inode, 0);
85 			inode->i_blocks = 0;
86 		}
87 		if ((file->f_flags & O_APPEND) &&
88 			(!v9fs_proto_dotu(v9ses) && !v9fs_proto_dotl(v9ses)))
89 			generic_file_llseek(file, 0, SEEK_END);
90 	}
91 
92 	file->private_data = fid;
93 	mutex_lock(&v9inode->v_mutex);
94 	if (v9ses->cache && !v9inode->writeback_fid &&
95 	    ((file->f_flags & O_ACCMODE) != O_RDONLY)) {
96 		/*
97 		 * clone a fid and add it to writeback_fid
98 		 * we do it during open time instead of
99 		 * page dirty time via write_begin/page_mkwrite
100 		 * because we want write after unlink usecase
101 		 * to work.
102 		 */
103 		fid = v9fs_writeback_fid(file->f_path.dentry);
104 		if (IS_ERR(fid)) {
105 			err = PTR_ERR(fid);
106 			mutex_unlock(&v9inode->v_mutex);
107 			goto out_error;
108 		}
109 		v9inode->writeback_fid = (void *) fid;
110 	}
111 	mutex_unlock(&v9inode->v_mutex);
112 #ifdef CONFIG_9P_FSCACHE
113 	if (v9ses->cache)
114 		v9fs_cache_inode_set_cookie(inode, file);
115 #endif
116 	return 0;
117 out_error:
118 	p9_client_clunk(file->private_data);
119 	file->private_data = NULL;
120 	return err;
121 }
122 
123 /**
124  * v9fs_file_lock - lock a file (or directory)
125  * @filp: file to be locked
126  * @cmd: lock command
127  * @fl: file lock structure
128  *
129  * Bugs: this looks like a local only lock, we should extend into 9P
130  *       by using open exclusive
131  */
132 
133 static int v9fs_file_lock(struct file *filp, int cmd, struct file_lock *fl)
134 {
135 	int res = 0;
136 	struct inode *inode = filp->f_path.dentry->d_inode;
137 
138 	p9_debug(P9_DEBUG_VFS, "filp: %p lock: %p\n", filp, fl);
139 
140 	/* No mandatory locks */
141 	if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK)
142 		return -ENOLCK;
143 
144 	if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
145 		filemap_write_and_wait(inode->i_mapping);
146 		invalidate_mapping_pages(&inode->i_data, 0, -1);
147 	}
148 
149 	return res;
150 }
151 
152 static int v9fs_file_do_lock(struct file *filp, int cmd, struct file_lock *fl)
153 {
154 	struct p9_flock flock;
155 	struct p9_fid *fid;
156 	uint8_t status;
157 	int res = 0;
158 	unsigned char fl_type;
159 
160 	fid = filp->private_data;
161 	BUG_ON(fid == NULL);
162 
163 	if ((fl->fl_flags & FL_POSIX) != FL_POSIX)
164 		BUG();
165 
166 	res = posix_lock_file_wait(filp, fl);
167 	if (res < 0)
168 		goto out;
169 
170 	/* convert posix lock to p9 tlock args */
171 	memset(&flock, 0, sizeof(flock));
172 	/* map the lock type */
173 	switch (fl->fl_type) {
174 	case F_RDLCK:
175 		flock.type = P9_LOCK_TYPE_RDLCK;
176 		break;
177 	case F_WRLCK:
178 		flock.type = P9_LOCK_TYPE_WRLCK;
179 		break;
180 	case F_UNLCK:
181 		flock.type = P9_LOCK_TYPE_UNLCK;
182 		break;
183 	}
184 	flock.start = fl->fl_start;
185 	if (fl->fl_end == OFFSET_MAX)
186 		flock.length = 0;
187 	else
188 		flock.length = fl->fl_end - fl->fl_start + 1;
189 	flock.proc_id = fl->fl_pid;
190 	flock.client_id = utsname()->nodename;
191 	if (IS_SETLKW(cmd))
192 		flock.flags = P9_LOCK_FLAGS_BLOCK;
193 
194 	/*
195 	 * if its a blocked request and we get P9_LOCK_BLOCKED as the status
196 	 * for lock request, keep on trying
197 	 */
198 	for (;;) {
199 		res = p9_client_lock_dotl(fid, &flock, &status);
200 		if (res < 0)
201 			break;
202 
203 		if (status != P9_LOCK_BLOCKED)
204 			break;
205 		if (status == P9_LOCK_BLOCKED && !IS_SETLKW(cmd))
206 			break;
207 		if (schedule_timeout_interruptible(P9_LOCK_TIMEOUT) != 0)
208 			break;
209 	}
210 
211 	/* map 9p status to VFS status */
212 	switch (status) {
213 	case P9_LOCK_SUCCESS:
214 		res = 0;
215 		break;
216 	case P9_LOCK_BLOCKED:
217 		res = -EAGAIN;
218 		break;
219 	case P9_LOCK_ERROR:
220 	case P9_LOCK_GRACE:
221 		res = -ENOLCK;
222 		break;
223 	default:
224 		BUG();
225 	}
226 
227 	/*
228 	 * incase server returned error for lock request, revert
229 	 * it locally
230 	 */
231 	if (res < 0 && fl->fl_type != F_UNLCK) {
232 		fl_type = fl->fl_type;
233 		fl->fl_type = F_UNLCK;
234 		res = posix_lock_file_wait(filp, fl);
235 		fl->fl_type = fl_type;
236 	}
237 out:
238 	return res;
239 }
240 
241 static int v9fs_file_getlock(struct file *filp, struct file_lock *fl)
242 {
243 	struct p9_getlock glock;
244 	struct p9_fid *fid;
245 	int res = 0;
246 
247 	fid = filp->private_data;
248 	BUG_ON(fid == NULL);
249 
250 	posix_test_lock(filp, fl);
251 	/*
252 	 * if we have a conflicting lock locally, no need to validate
253 	 * with server
254 	 */
255 	if (fl->fl_type != F_UNLCK)
256 		return res;
257 
258 	/* convert posix lock to p9 tgetlock args */
259 	memset(&glock, 0, sizeof(glock));
260 	glock.type  = P9_LOCK_TYPE_UNLCK;
261 	glock.start = fl->fl_start;
262 	if (fl->fl_end == OFFSET_MAX)
263 		glock.length = 0;
264 	else
265 		glock.length = fl->fl_end - fl->fl_start + 1;
266 	glock.proc_id = fl->fl_pid;
267 	glock.client_id = utsname()->nodename;
268 
269 	res = p9_client_getlock_dotl(fid, &glock);
270 	if (res < 0)
271 		return res;
272 	/* map 9p lock type to os lock type */
273 	switch (glock.type) {
274 	case P9_LOCK_TYPE_RDLCK:
275 		fl->fl_type = F_RDLCK;
276 		break;
277 	case P9_LOCK_TYPE_WRLCK:
278 		fl->fl_type = F_WRLCK;
279 		break;
280 	case P9_LOCK_TYPE_UNLCK:
281 		fl->fl_type = F_UNLCK;
282 		break;
283 	}
284 	if (glock.type != P9_LOCK_TYPE_UNLCK) {
285 		fl->fl_start = glock.start;
286 		if (glock.length == 0)
287 			fl->fl_end = OFFSET_MAX;
288 		else
289 			fl->fl_end = glock.start + glock.length - 1;
290 		fl->fl_pid = glock.proc_id;
291 	}
292 	return res;
293 }
294 
295 /**
296  * v9fs_file_lock_dotl - lock a file (or directory)
297  * @filp: file to be locked
298  * @cmd: lock command
299  * @fl: file lock structure
300  *
301  */
302 
303 static int v9fs_file_lock_dotl(struct file *filp, int cmd, struct file_lock *fl)
304 {
305 	struct inode *inode = filp->f_path.dentry->d_inode;
306 	int ret = -ENOLCK;
307 
308 	p9_debug(P9_DEBUG_VFS, "filp: %p cmd:%d lock: %p name: %s\n",
309 		 filp, cmd, fl, filp->f_path.dentry->d_name.name);
310 
311 	/* No mandatory locks */
312 	if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK)
313 		goto out_err;
314 
315 	if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
316 		filemap_write_and_wait(inode->i_mapping);
317 		invalidate_mapping_pages(&inode->i_data, 0, -1);
318 	}
319 
320 	if (IS_SETLK(cmd) || IS_SETLKW(cmd))
321 		ret = v9fs_file_do_lock(filp, cmd, fl);
322 	else if (IS_GETLK(cmd))
323 		ret = v9fs_file_getlock(filp, fl);
324 	else
325 		ret = -EINVAL;
326 out_err:
327 	return ret;
328 }
329 
330 /**
331  * v9fs_file_flock_dotl - lock a file
332  * @filp: file to be locked
333  * @cmd: lock command
334  * @fl: file lock structure
335  *
336  */
337 
338 static int v9fs_file_flock_dotl(struct file *filp, int cmd,
339 	struct file_lock *fl)
340 {
341 	struct inode *inode = filp->f_path.dentry->d_inode;
342 	int ret = -ENOLCK;
343 
344 	p9_debug(P9_DEBUG_VFS, "filp: %p cmd:%d lock: %p name: %s\n",
345 		 filp, cmd, fl, filp->f_path.dentry->d_name.name);
346 
347 	/* No mandatory locks */
348 	if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK)
349 		goto out_err;
350 
351 	if (!(fl->fl_flags & FL_FLOCK))
352 		goto out_err;
353 
354 	if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
355 		filemap_write_and_wait(inode->i_mapping);
356 		invalidate_mapping_pages(&inode->i_data, 0, -1);
357 	}
358 	/* Convert flock to posix lock */
359 	fl->fl_owner = (fl_owner_t)filp;
360 	fl->fl_start = 0;
361 	fl->fl_end = OFFSET_MAX;
362 	fl->fl_flags |= FL_POSIX;
363 	fl->fl_flags ^= FL_FLOCK;
364 
365 	if (IS_SETLK(cmd) | IS_SETLKW(cmd))
366 		ret = v9fs_file_do_lock(filp, cmd, fl);
367 	else
368 		ret = -EINVAL;
369 out_err:
370 	return ret;
371 }
372 
373 /**
374  * v9fs_fid_readn - read from a fid
375  * @fid: fid to read
376  * @data: data buffer to read data into
377  * @udata: user data buffer to read data into
378  * @count: size of buffer
379  * @offset: offset at which to read data
380  *
381  */
382 ssize_t
383 v9fs_fid_readn(struct p9_fid *fid, char *data, char __user *udata, u32 count,
384 	       u64 offset)
385 {
386 	int n, total, size;
387 
388 	p9_debug(P9_DEBUG_VFS, "fid %d offset %llu count %d\n",
389 		 fid->fid, (long long unsigned)offset, count);
390 	n = 0;
391 	total = 0;
392 	size = fid->iounit ? fid->iounit : fid->clnt->msize - P9_IOHDRSZ;
393 	do {
394 		n = p9_client_read(fid, data, udata, offset, count);
395 		if (n <= 0)
396 			break;
397 
398 		if (data)
399 			data += n;
400 		if (udata)
401 			udata += n;
402 
403 		offset += n;
404 		count -= n;
405 		total += n;
406 	} while (count > 0 && n == size);
407 
408 	if (n < 0)
409 		total = n;
410 
411 	return total;
412 }
413 
414 /**
415  * v9fs_file_readn - read from a file
416  * @filp: file pointer to read
417  * @data: data buffer to read data into
418  * @udata: user data buffer to read data into
419  * @count: size of buffer
420  * @offset: offset at which to read data
421  *
422  */
423 ssize_t
424 v9fs_file_readn(struct file *filp, char *data, char __user *udata, u32 count,
425 	       u64 offset)
426 {
427 	return v9fs_fid_readn(filp->private_data, data, udata, count, offset);
428 }
429 
430 /**
431  * v9fs_file_read - read from a file
432  * @filp: file pointer to read
433  * @udata: user data buffer to read data into
434  * @count: size of buffer
435  * @offset: offset at which to read data
436  *
437  */
438 
439 static ssize_t
440 v9fs_file_read(struct file *filp, char __user *udata, size_t count,
441 	       loff_t * offset)
442 {
443 	int ret;
444 	struct p9_fid *fid;
445 	size_t size;
446 
447 	p9_debug(P9_DEBUG_VFS, "count %zu offset %lld\n", count, *offset);
448 	fid = filp->private_data;
449 
450 	size = fid->iounit ? fid->iounit : fid->clnt->msize - P9_IOHDRSZ;
451 	if (count > size)
452 		ret = v9fs_file_readn(filp, NULL, udata, count, *offset);
453 	else
454 		ret = p9_client_read(fid, NULL, udata, *offset, count);
455 
456 	if (ret > 0)
457 		*offset += ret;
458 
459 	return ret;
460 }
461 
462 ssize_t
463 v9fs_file_write_internal(struct inode *inode, struct p9_fid *fid,
464 			 const char __user *data, size_t count,
465 			 loff_t *offset, int invalidate)
466 {
467 	int n;
468 	loff_t i_size;
469 	size_t total = 0;
470 	struct p9_client *clnt;
471 	loff_t origin = *offset;
472 	unsigned long pg_start, pg_end;
473 
474 	p9_debug(P9_DEBUG_VFS, "data %p count %d offset %x\n",
475 		 data, (int)count, (int)*offset);
476 
477 	clnt = fid->clnt;
478 	do {
479 		n = p9_client_write(fid, NULL, data+total, origin+total, count);
480 		if (n <= 0)
481 			break;
482 		count -= n;
483 		total += n;
484 	} while (count > 0);
485 
486 	if (invalidate && (total > 0)) {
487 		pg_start = origin >> PAGE_CACHE_SHIFT;
488 		pg_end = (origin + total - 1) >> PAGE_CACHE_SHIFT;
489 		if (inode->i_mapping && inode->i_mapping->nrpages)
490 			invalidate_inode_pages2_range(inode->i_mapping,
491 						      pg_start, pg_end);
492 		*offset += total;
493 		i_size = i_size_read(inode);
494 		if (*offset > i_size) {
495 			inode_add_bytes(inode, *offset - i_size);
496 			i_size_write(inode, *offset);
497 		}
498 	}
499 	if (n < 0)
500 		return n;
501 
502 	return total;
503 }
504 
505 /**
506  * v9fs_file_write - write to a file
507  * @filp: file pointer to write
508  * @data: data buffer to write data from
509  * @count: size of buffer
510  * @offset: offset at which to write data
511  *
512  */
513 static ssize_t
514 v9fs_file_write(struct file *filp, const char __user * data,
515 		size_t count, loff_t *offset)
516 {
517 	ssize_t retval = 0;
518 	loff_t origin = *offset;
519 
520 
521 	retval = generic_write_checks(filp, &origin, &count, 0);
522 	if (retval)
523 		goto out;
524 
525 	retval = -EINVAL;
526 	if ((ssize_t) count < 0)
527 		goto out;
528 	retval = 0;
529 	if (!count)
530 		goto out;
531 
532 	retval = v9fs_file_write_internal(filp->f_path.dentry->d_inode,
533 					filp->private_data,
534 					data, count, &origin, 1);
535 	/* update offset on successful write */
536 	if (retval > 0)
537 		*offset = origin;
538 out:
539 	return retval;
540 }
541 
542 
543 static int v9fs_file_fsync(struct file *filp, loff_t start, loff_t end,
544 			   int datasync)
545 {
546 	struct p9_fid *fid;
547 	struct inode *inode = filp->f_mapping->host;
548 	struct p9_wstat wstat;
549 	int retval;
550 
551 	retval = filemap_write_and_wait_range(inode->i_mapping, start, end);
552 	if (retval)
553 		return retval;
554 
555 	mutex_lock(&inode->i_mutex);
556 	p9_debug(P9_DEBUG_VFS, "filp %p datasync %x\n", filp, datasync);
557 
558 	fid = filp->private_data;
559 	v9fs_blank_wstat(&wstat);
560 
561 	retval = p9_client_wstat(fid, &wstat);
562 	mutex_unlock(&inode->i_mutex);
563 
564 	return retval;
565 }
566 
567 int v9fs_file_fsync_dotl(struct file *filp, loff_t start, loff_t end,
568 			 int datasync)
569 {
570 	struct p9_fid *fid;
571 	struct inode *inode = filp->f_mapping->host;
572 	int retval;
573 
574 	retval = filemap_write_and_wait_range(inode->i_mapping, start, end);
575 	if (retval)
576 		return retval;
577 
578 	mutex_lock(&inode->i_mutex);
579 	p9_debug(P9_DEBUG_VFS, "filp %p datasync %x\n", filp, datasync);
580 
581 	fid = filp->private_data;
582 
583 	retval = p9_client_fsync(fid, datasync);
584 	mutex_unlock(&inode->i_mutex);
585 
586 	return retval;
587 }
588 
589 static int
590 v9fs_file_mmap(struct file *file, struct vm_area_struct *vma)
591 {
592 	int retval;
593 
594 	retval = generic_file_mmap(file, vma);
595 	if (!retval)
596 		vma->vm_ops = &v9fs_file_vm_ops;
597 
598 	return retval;
599 }
600 
601 static int
602 v9fs_vm_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
603 {
604 	struct v9fs_inode *v9inode;
605 	struct page *page = vmf->page;
606 	struct file *filp = vma->vm_file;
607 	struct inode *inode = filp->f_path.dentry->d_inode;
608 
609 
610 	p9_debug(P9_DEBUG_VFS, "page %p fid %lx\n",
611 		 page, (unsigned long)filp->private_data);
612 
613 	/* Update file times before taking page lock */
614 	file_update_time(filp);
615 
616 	v9inode = V9FS_I(inode);
617 	/* make sure the cache has finished storing the page */
618 	v9fs_fscache_wait_on_page_write(inode, page);
619 	BUG_ON(!v9inode->writeback_fid);
620 	lock_page(page);
621 	if (page->mapping != inode->i_mapping)
622 		goto out_unlock;
623 
624 	return VM_FAULT_LOCKED;
625 out_unlock:
626 	unlock_page(page);
627 	return VM_FAULT_NOPAGE;
628 }
629 
630 static ssize_t
631 v9fs_direct_read(struct file *filp, char __user *udata, size_t count,
632 		 loff_t *offsetp)
633 {
634 	loff_t size, offset;
635 	struct inode *inode;
636 	struct address_space *mapping;
637 
638 	offset = *offsetp;
639 	mapping = filp->f_mapping;
640 	inode = mapping->host;
641 	if (!count)
642 		return 0;
643 	size = i_size_read(inode);
644 	if (offset < size)
645 		filemap_write_and_wait_range(mapping, offset,
646 					     offset + count - 1);
647 
648 	return v9fs_file_read(filp, udata, count, offsetp);
649 }
650 
651 /**
652  * v9fs_cached_file_read - read from a file
653  * @filp: file pointer to read
654  * @udata: user data buffer to read data into
655  * @count: size of buffer
656  * @offset: offset at which to read data
657  *
658  */
659 static ssize_t
660 v9fs_cached_file_read(struct file *filp, char __user *data, size_t count,
661 		      loff_t *offset)
662 {
663 	if (filp->f_flags & O_DIRECT)
664 		return v9fs_direct_read(filp, data, count, offset);
665 	return do_sync_read(filp, data, count, offset);
666 }
667 
668 static ssize_t
669 v9fs_direct_write(struct file *filp, const char __user * data,
670 		  size_t count, loff_t *offsetp)
671 {
672 	loff_t offset;
673 	ssize_t retval;
674 	struct inode *inode;
675 	struct address_space *mapping;
676 
677 	offset = *offsetp;
678 	mapping = filp->f_mapping;
679 	inode = mapping->host;
680 	if (!count)
681 		return 0;
682 
683 	mutex_lock(&inode->i_mutex);
684 	retval = filemap_write_and_wait_range(mapping, offset,
685 					      offset + count - 1);
686 	if (retval)
687 		goto err_out;
688 	/*
689 	 * After a write we want buffered reads to be sure to go to disk to get
690 	 * the new data.  We invalidate clean cached page from the region we're
691 	 * about to write.  We do this *before* the write so that if we fail
692 	 * here we fall back to buffered write
693 	 */
694 	if (mapping->nrpages) {
695 		pgoff_t pg_start = offset >> PAGE_CACHE_SHIFT;
696 		pgoff_t pg_end   = (offset + count - 1) >> PAGE_CACHE_SHIFT;
697 
698 		retval = invalidate_inode_pages2_range(mapping,
699 							pg_start, pg_end);
700 		/*
701 		 * If a page can not be invalidated, fall back
702 		 * to buffered write.
703 		 */
704 		if (retval) {
705 			if (retval == -EBUSY)
706 				goto buff_write;
707 			goto err_out;
708 		}
709 	}
710 	retval = v9fs_file_write(filp, data, count, offsetp);
711 err_out:
712 	mutex_unlock(&inode->i_mutex);
713 	return retval;
714 
715 buff_write:
716 	mutex_unlock(&inode->i_mutex);
717 	return do_sync_write(filp, data, count, offsetp);
718 }
719 
720 /**
721  * v9fs_cached_file_write - write to a file
722  * @filp: file pointer to write
723  * @data: data buffer to write data from
724  * @count: size of buffer
725  * @offset: offset at which to write data
726  *
727  */
728 static ssize_t
729 v9fs_cached_file_write(struct file *filp, const char __user * data,
730 		       size_t count, loff_t *offset)
731 {
732 
733 	if (filp->f_flags & O_DIRECT)
734 		return v9fs_direct_write(filp, data, count, offset);
735 	return do_sync_write(filp, data, count, offset);
736 }
737 
738 static const struct vm_operations_struct v9fs_file_vm_ops = {
739 	.fault = filemap_fault,
740 	.page_mkwrite = v9fs_vm_page_mkwrite,
741 };
742 
743 
744 const struct file_operations v9fs_cached_file_operations = {
745 	.llseek = generic_file_llseek,
746 	.read = v9fs_cached_file_read,
747 	.write = v9fs_cached_file_write,
748 	.aio_read = generic_file_aio_read,
749 	.aio_write = generic_file_aio_write,
750 	.open = v9fs_file_open,
751 	.release = v9fs_dir_release,
752 	.lock = v9fs_file_lock,
753 	.mmap = v9fs_file_mmap,
754 	.fsync = v9fs_file_fsync,
755 };
756 
757 const struct file_operations v9fs_cached_file_operations_dotl = {
758 	.llseek = generic_file_llseek,
759 	.read = v9fs_cached_file_read,
760 	.write = v9fs_cached_file_write,
761 	.aio_read = generic_file_aio_read,
762 	.aio_write = generic_file_aio_write,
763 	.open = v9fs_file_open,
764 	.release = v9fs_dir_release,
765 	.lock = v9fs_file_lock_dotl,
766 	.flock = v9fs_file_flock_dotl,
767 	.mmap = v9fs_file_mmap,
768 	.fsync = v9fs_file_fsync_dotl,
769 };
770 
771 const struct file_operations v9fs_file_operations = {
772 	.llseek = generic_file_llseek,
773 	.read = v9fs_file_read,
774 	.write = v9fs_file_write,
775 	.open = v9fs_file_open,
776 	.release = v9fs_dir_release,
777 	.lock = v9fs_file_lock,
778 	.mmap = generic_file_readonly_mmap,
779 	.fsync = v9fs_file_fsync,
780 };
781 
782 const struct file_operations v9fs_file_operations_dotl = {
783 	.llseek = generic_file_llseek,
784 	.read = v9fs_file_read,
785 	.write = v9fs_file_write,
786 	.open = v9fs_file_open,
787 	.release = v9fs_dir_release,
788 	.lock = v9fs_file_lock_dotl,
789 	.flock = v9fs_file_flock_dotl,
790 	.mmap = generic_file_readonly_mmap,
791 	.fsync = v9fs_file_fsync_dotl,
792 };
793