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  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
 47static const struct vm_operations_struct v9fs_file_vm_ops;
 48static const struct vm_operations_struct v9fs_mmap_file_vm_ops;
 49
 50/**
 51 * v9fs_file_open - open a file (or directory)
 52 * @inode: inode to be opened
 53 * @file: file being opened
 54 *
 55 */
 56
 57int v9fs_file_open(struct inode *inode, struct file *file)
 58{
 59	int err;
 60	struct v9fs_inode *v9inode;
 61	struct v9fs_session_info *v9ses;
 62	struct p9_fid *fid;
 63	int omode;
 64
 65	p9_debug(P9_DEBUG_VFS, "inode: %p file: %p\n", inode, file);
 66	v9inode = V9FS_I(inode);
 67	v9ses = v9fs_inode2v9ses(inode);
 68	if (v9fs_proto_dotl(v9ses))
 69		omode = v9fs_open_to_dotl_flags(file->f_flags);
 70	else
 71		omode = v9fs_uflags2omode(file->f_flags,
 72					v9fs_proto_dotu(v9ses));
 73	fid = file->private_data;
 74	if (!fid) {
 75		fid = v9fs_fid_clone(file->f_path.dentry);
 76		if (IS_ERR(fid))
 77			return PTR_ERR(fid);
 78
 79		err = p9_client_open(fid, omode);
 80		if (err < 0) {
 81			p9_client_clunk(fid);
 82			return err;
 83		}
 84		if ((file->f_flags & O_APPEND) &&
 85			(!v9fs_proto_dotu(v9ses) && !v9fs_proto_dotl(v9ses)))
 86			generic_file_llseek(file, 0, SEEK_END);
 87	}
 88
 89	file->private_data = fid;
 90	mutex_lock(&v9inode->v_mutex);
 91	if ((v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) &&
 92	    !v9inode->writeback_fid &&
 93	    ((file->f_flags & O_ACCMODE) != O_RDONLY)) {
 94		/*
 95		 * clone a fid and add it to writeback_fid
 96		 * we do it during open time instead of
 97		 * page dirty time via write_begin/page_mkwrite
 98		 * because we want write after unlink usecase
 99		 * to work.
100		 */
101		fid = v9fs_writeback_fid(file->f_path.dentry);
102		if (IS_ERR(fid)) {
103			err = PTR_ERR(fid);
104			mutex_unlock(&v9inode->v_mutex);
105			goto out_error;
106		}
107		v9inode->writeback_fid = (void *) fid;
108	}
109	mutex_unlock(&v9inode->v_mutex);
110	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
111		v9fs_cache_inode_set_cookie(inode, file);
112	return 0;
113out_error:
114	p9_client_clunk(file->private_data);
115	file->private_data = NULL;
116	return err;
117}
118
119/**
120 * v9fs_file_lock - lock a file (or directory)
121 * @filp: file to be locked
122 * @cmd: lock command
123 * @fl: file lock structure
124 *
125 * Bugs: this looks like a local only lock, we should extend into 9P
126 *       by using open exclusive
127 */
128
129static int v9fs_file_lock(struct file *filp, int cmd, struct file_lock *fl)
130{
131	int res = 0;
132	struct inode *inode = file_inode(filp);
133
134	p9_debug(P9_DEBUG_VFS, "filp: %p lock: %p\n", filp, fl);
135
136	/* No mandatory locks */
137	if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK)
138		return -ENOLCK;
139
140	if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
141		filemap_write_and_wait(inode->i_mapping);
142		invalidate_mapping_pages(&inode->i_data, 0, -1);
143	}
144
145	return res;
146}
147
148static int v9fs_file_do_lock(struct file *filp, int cmd, struct file_lock *fl)
149{
150	struct p9_flock flock;
151	struct p9_fid *fid;
152	uint8_t status;
153	int res = 0;
154	unsigned char fl_type;
155
156	fid = filp->private_data;
157	BUG_ON(fid == NULL);
158
159	if ((fl->fl_flags & FL_POSIX) != FL_POSIX)
160		BUG();
161
162	res = posix_lock_file_wait(filp, fl);
163	if (res < 0)
164		goto out;
165
166	/* convert posix lock to p9 tlock args */
167	memset(&flock, 0, sizeof(flock));
168	/* map the lock type */
169	switch (fl->fl_type) {
170	case F_RDLCK:
171		flock.type = P9_LOCK_TYPE_RDLCK;
172		break;
173	case F_WRLCK:
174		flock.type = P9_LOCK_TYPE_WRLCK;
175		break;
176	case F_UNLCK:
177		flock.type = P9_LOCK_TYPE_UNLCK;
178		break;
179	}
180	flock.start = fl->fl_start;
181	if (fl->fl_end == OFFSET_MAX)
182		flock.length = 0;
183	else
184		flock.length = fl->fl_end - fl->fl_start + 1;
185	flock.proc_id = fl->fl_pid;
186	flock.client_id = fid->clnt->name;
187	if (IS_SETLKW(cmd))
188		flock.flags = P9_LOCK_FLAGS_BLOCK;
189
190	/*
191	 * if its a blocked request and we get P9_LOCK_BLOCKED as the status
192	 * for lock request, keep on trying
193	 */
194	for (;;) {
195		res = p9_client_lock_dotl(fid, &flock, &status);
196		if (res < 0)
197			break;
198
199		if (status != P9_LOCK_BLOCKED)
200			break;
201		if (status == P9_LOCK_BLOCKED && !IS_SETLKW(cmd))
202			break;
203		if (schedule_timeout_interruptible(P9_LOCK_TIMEOUT) != 0)
204			break;
205	}
206
207	/* map 9p status to VFS status */
208	switch (status) {
209	case P9_LOCK_SUCCESS:
210		res = 0;
211		break;
212	case P9_LOCK_BLOCKED:
213		res = -EAGAIN;
214		break;
 
 
 
215	case P9_LOCK_ERROR:
216	case P9_LOCK_GRACE:
217		res = -ENOLCK;
218		break;
219	default:
220		BUG();
221	}
222
 
223	/*
224	 * incase server returned error for lock request, revert
225	 * it locally
226	 */
227	if (res < 0 && fl->fl_type != F_UNLCK) {
228		fl_type = fl->fl_type;
229		fl->fl_type = F_UNLCK;
230		res = posix_lock_file_wait(filp, fl);
 
231		fl->fl_type = fl_type;
232	}
233out:
234	return res;
235}
236
237static int v9fs_file_getlock(struct file *filp, struct file_lock *fl)
238{
239	struct p9_getlock glock;
240	struct p9_fid *fid;
241	int res = 0;
242
243	fid = filp->private_data;
244	BUG_ON(fid == NULL);
245
246	posix_test_lock(filp, fl);
247	/*
248	 * if we have a conflicting lock locally, no need to validate
249	 * with server
250	 */
251	if (fl->fl_type != F_UNLCK)
252		return res;
253
254	/* convert posix lock to p9 tgetlock args */
255	memset(&glock, 0, sizeof(glock));
256	glock.type  = P9_LOCK_TYPE_UNLCK;
257	glock.start = fl->fl_start;
258	if (fl->fl_end == OFFSET_MAX)
259		glock.length = 0;
260	else
261		glock.length = fl->fl_end - fl->fl_start + 1;
262	glock.proc_id = fl->fl_pid;
263	glock.client_id = fid->clnt->name;
264
265	res = p9_client_getlock_dotl(fid, &glock);
266	if (res < 0)
267		return res;
268	/* map 9p lock type to os lock type */
269	switch (glock.type) {
270	case P9_LOCK_TYPE_RDLCK:
271		fl->fl_type = F_RDLCK;
272		break;
273	case P9_LOCK_TYPE_WRLCK:
274		fl->fl_type = F_WRLCK;
275		break;
276	case P9_LOCK_TYPE_UNLCK:
277		fl->fl_type = F_UNLCK;
278		break;
279	}
280	if (glock.type != P9_LOCK_TYPE_UNLCK) {
281		fl->fl_start = glock.start;
282		if (glock.length == 0)
283			fl->fl_end = OFFSET_MAX;
284		else
285			fl->fl_end = glock.start + glock.length - 1;
286		fl->fl_pid = glock.proc_id;
287	}
 
288	return res;
289}
290
291/**
292 * v9fs_file_lock_dotl - lock a file (or directory)
293 * @filp: file to be locked
294 * @cmd: lock command
295 * @fl: file lock structure
296 *
297 */
298
299static int v9fs_file_lock_dotl(struct file *filp, int cmd, struct file_lock *fl)
300{
301	struct inode *inode = file_inode(filp);
302	int ret = -ENOLCK;
303
304	p9_debug(P9_DEBUG_VFS, "filp: %p cmd:%d lock: %p name: %s\n",
305		 filp, cmd, fl, filp->f_path.dentry->d_name.name);
306
307	/* No mandatory locks */
308	if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK)
309		goto out_err;
310
311	if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
312		filemap_write_and_wait(inode->i_mapping);
313		invalidate_mapping_pages(&inode->i_data, 0, -1);
314	}
315
316	if (IS_SETLK(cmd) || IS_SETLKW(cmd))
317		ret = v9fs_file_do_lock(filp, cmd, fl);
318	else if (IS_GETLK(cmd))
319		ret = v9fs_file_getlock(filp, fl);
320	else
321		ret = -EINVAL;
322out_err:
323	return ret;
324}
325
326/**
327 * v9fs_file_flock_dotl - lock a file
328 * @filp: file to be locked
329 * @cmd: lock command
330 * @fl: file lock structure
331 *
332 */
333
334static int v9fs_file_flock_dotl(struct file *filp, int cmd,
335	struct file_lock *fl)
336{
337	struct inode *inode = file_inode(filp);
338	int ret = -ENOLCK;
339
340	p9_debug(P9_DEBUG_VFS, "filp: %p cmd:%d lock: %p name: %s\n",
341		 filp, cmd, fl, filp->f_path.dentry->d_name.name);
342
343	/* No mandatory locks */
344	if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK)
345		goto out_err;
346
347	if (!(fl->fl_flags & FL_FLOCK))
348		goto out_err;
349
350	if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
351		filemap_write_and_wait(inode->i_mapping);
352		invalidate_mapping_pages(&inode->i_data, 0, -1);
353	}
354	/* Convert flock to posix lock */
355	fl->fl_owner = (fl_owner_t)filp;
356	fl->fl_start = 0;
357	fl->fl_end = OFFSET_MAX;
358	fl->fl_flags |= FL_POSIX;
359	fl->fl_flags ^= FL_FLOCK;
360
361	if (IS_SETLK(cmd) | IS_SETLKW(cmd))
362		ret = v9fs_file_do_lock(filp, cmd, fl);
363	else
364		ret = -EINVAL;
365out_err:
366	return ret;
367}
368
369/**
370 * v9fs_fid_readn - read from a fid
371 * @fid: fid to read
372 * @data: data buffer to read data into
373 * @udata: user data buffer to read data into
374 * @count: size of buffer
375 * @offset: offset at which to read data
376 *
377 */
378ssize_t
379v9fs_fid_readn(struct p9_fid *fid, char *data, char __user *udata, u32 count,
380	       u64 offset)
381{
382	int n, total, size;
383
384	p9_debug(P9_DEBUG_VFS, "fid %d offset %llu count %d\n",
385		 fid->fid, (long long unsigned)offset, count);
386	n = 0;
387	total = 0;
388	size = fid->iounit ? fid->iounit : fid->clnt->msize - P9_IOHDRSZ;
389	do {
390		n = p9_client_read(fid, data, udata, offset, count);
391		if (n <= 0)
392			break;
393
394		if (data)
395			data += n;
396		if (udata)
397			udata += n;
398
399		offset += n;
400		count -= n;
401		total += n;
402	} while (count > 0 && n == size);
403
404	if (n < 0)
405		total = n;
406
407	return total;
408}
409
410/**
411 * v9fs_file_readn - read from a file
412 * @filp: file pointer to read
413 * @data: data buffer to read data into
414 * @udata: user data buffer to read data into
415 * @count: size of buffer
416 * @offset: offset at which to read data
417 *
418 */
419ssize_t
420v9fs_file_readn(struct file *filp, char *data, char __user *udata, u32 count,
421	       u64 offset)
422{
423	return v9fs_fid_readn(filp->private_data, data, udata, count, offset);
424}
425
426/**
427 * v9fs_file_read - read from a file
428 * @filp: file pointer to read
429 * @udata: user data buffer to read data into
430 * @count: size of buffer
431 * @offset: offset at which to read data
432 *
433 */
434
435static ssize_t
436v9fs_file_read(struct file *filp, char __user *udata, size_t count,
437	       loff_t * offset)
438{
439	int ret;
440	struct p9_fid *fid;
441	size_t size;
442
443	p9_debug(P9_DEBUG_VFS, "count %zu offset %lld\n", count, *offset);
444	fid = filp->private_data;
445
446	size = fid->iounit ? fid->iounit : fid->clnt->msize - P9_IOHDRSZ;
447	if (count > size)
448		ret = v9fs_file_readn(filp, NULL, udata, count, *offset);
449	else
450		ret = p9_client_read(fid, NULL, udata, *offset, count);
451
452	if (ret > 0)
453		*offset += ret;
 
454
 
455	return ret;
456}
457
458ssize_t
459v9fs_file_write_internal(struct inode *inode, struct p9_fid *fid,
460			 const char __user *data, size_t count,
461			 loff_t *offset, int invalidate)
462{
463	int n;
464	loff_t i_size;
465	size_t total = 0;
466	loff_t origin = *offset;
467	unsigned long pg_start, pg_end;
468
469	p9_debug(P9_DEBUG_VFS, "data %p count %d offset %x\n",
470		 data, (int)count, (int)*offset);
471
472	do {
473		n = p9_client_write(fid, NULL, data+total, origin+total, count);
474		if (n <= 0)
475			break;
476		count -= n;
477		total += n;
478	} while (count > 0);
479
480	if (invalidate && (total > 0)) {
481		pg_start = origin >> PAGE_CACHE_SHIFT;
482		pg_end = (origin + total - 1) >> PAGE_CACHE_SHIFT;
483		if (inode->i_mapping && inode->i_mapping->nrpages)
484			invalidate_inode_pages2_range(inode->i_mapping,
485						      pg_start, pg_end);
486		*offset += total;
487		i_size = i_size_read(inode);
488		if (*offset > i_size) {
489			inode_add_bytes(inode, *offset - i_size);
490			i_size_write(inode, *offset);
491		}
492	}
493	if (n < 0)
494		return n;
495
496	return total;
497}
498
499/**
500 * v9fs_file_write - write to a file
501 * @filp: file pointer to write
502 * @data: data buffer to write data from
503 * @count: size of buffer
504 * @offset: offset at which to write data
505 *
506 */
507static ssize_t
508v9fs_file_write(struct file *filp, const char __user * data,
509		size_t count, loff_t *offset)
510{
511	ssize_t retval = 0;
512	loff_t origin = *offset;
513
514
515	retval = generic_write_checks(filp, &origin, &count, 0);
516	if (retval)
517		goto out;
518
519	retval = -EINVAL;
520	if ((ssize_t) count < 0)
521		goto out;
522	retval = 0;
523	if (!count)
524		goto out;
525
526	retval = v9fs_file_write_internal(file_inode(filp),
527					filp->private_data,
528					data, count, &origin, 1);
529	/* update offset on successful write */
530	if (retval > 0)
531		*offset = origin;
532out:
533	return retval;
 
 
 
 
 
 
 
 
 
 
 
 
534}
535
536
537static int v9fs_file_fsync(struct file *filp, loff_t start, loff_t end,
538			   int datasync)
539{
540	struct p9_fid *fid;
541	struct inode *inode = filp->f_mapping->host;
542	struct p9_wstat wstat;
543	int retval;
544
545	retval = filemap_write_and_wait_range(inode->i_mapping, start, end);
546	if (retval)
547		return retval;
548
549	mutex_lock(&inode->i_mutex);
550	p9_debug(P9_DEBUG_VFS, "filp %p datasync %x\n", filp, datasync);
551
552	fid = filp->private_data;
553	v9fs_blank_wstat(&wstat);
554
555	retval = p9_client_wstat(fid, &wstat);
556	mutex_unlock(&inode->i_mutex);
557
558	return retval;
559}
560
561int v9fs_file_fsync_dotl(struct file *filp, loff_t start, loff_t end,
562			 int datasync)
563{
564	struct p9_fid *fid;
565	struct inode *inode = filp->f_mapping->host;
566	int retval;
567
568	retval = filemap_write_and_wait_range(inode->i_mapping, start, end);
569	if (retval)
570		return retval;
571
572	mutex_lock(&inode->i_mutex);
573	p9_debug(P9_DEBUG_VFS, "filp %p datasync %x\n", filp, datasync);
574
575	fid = filp->private_data;
576
577	retval = p9_client_fsync(fid, datasync);
578	mutex_unlock(&inode->i_mutex);
579
580	return retval;
581}
582
583static int
584v9fs_file_mmap(struct file *filp, struct vm_area_struct *vma)
585{
586	int retval;
587
588
589	retval = generic_file_mmap(filp, vma);
590	if (!retval)
591		vma->vm_ops = &v9fs_file_vm_ops;
592
593	return retval;
594}
595
596static int
597v9fs_mmap_file_mmap(struct file *filp, struct vm_area_struct *vma)
598{
599	int retval;
600	struct inode *inode;
601	struct v9fs_inode *v9inode;
602	struct p9_fid *fid;
603
604	inode = file_inode(filp);
605	v9inode = V9FS_I(inode);
606	mutex_lock(&v9inode->v_mutex);
607	if (!v9inode->writeback_fid &&
608	    (vma->vm_flags & VM_WRITE)) {
609		/*
610		 * clone a fid and add it to writeback_fid
611		 * we do it during mmap instead of
612		 * page dirty time via write_begin/page_mkwrite
613		 * because we want write after unlink usecase
614		 * to work.
615		 */
616		fid = v9fs_writeback_fid(filp->f_path.dentry);
617		if (IS_ERR(fid)) {
618			retval = PTR_ERR(fid);
619			mutex_unlock(&v9inode->v_mutex);
620			return retval;
621		}
622		v9inode->writeback_fid = (void *) fid;
623	}
624	mutex_unlock(&v9inode->v_mutex);
625
626	retval = generic_file_mmap(filp, vma);
627	if (!retval)
628		vma->vm_ops = &v9fs_mmap_file_vm_ops;
629
630	return retval;
631}
632
633static int
634v9fs_vm_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
635{
636	struct v9fs_inode *v9inode;
637	struct page *page = vmf->page;
638	struct file *filp = vma->vm_file;
639	struct inode *inode = file_inode(filp);
640
641
642	p9_debug(P9_DEBUG_VFS, "page %p fid %lx\n",
643		 page, (unsigned long)filp->private_data);
644
645	/* Update file times before taking page lock */
646	file_update_time(filp);
647
648	v9inode = V9FS_I(inode);
649	/* make sure the cache has finished storing the page */
650	v9fs_fscache_wait_on_page_write(inode, page);
651	BUG_ON(!v9inode->writeback_fid);
652	lock_page(page);
653	if (page->mapping != inode->i_mapping)
654		goto out_unlock;
655	wait_for_stable_page(page);
656
657	return VM_FAULT_LOCKED;
658out_unlock:
659	unlock_page(page);
660	return VM_FAULT_NOPAGE;
661}
662
663static ssize_t
664v9fs_direct_read(struct file *filp, char __user *udata, size_t count,
665		 loff_t *offsetp)
666{
667	loff_t size, offset;
668	struct inode *inode;
669	struct address_space *mapping;
670
671	offset = *offsetp;
672	mapping = filp->f_mapping;
673	inode = mapping->host;
674	if (!count)
675		return 0;
676	size = i_size_read(inode);
677	if (offset < size)
678		filemap_write_and_wait_range(mapping, offset,
679					     offset + count - 1);
680
681	return v9fs_file_read(filp, udata, count, offsetp);
682}
683
684/**
685 * v9fs_cached_file_read - read from a file
686 * @filp: file pointer to read
687 * @udata: user data buffer to read data into
688 * @count: size of buffer
689 * @offset: offset at which to read data
690 *
691 */
692static ssize_t
693v9fs_cached_file_read(struct file *filp, char __user *data, size_t count,
694		      loff_t *offset)
695{
696	if (filp->f_flags & O_DIRECT)
697		return v9fs_direct_read(filp, data, count, offset);
698	return do_sync_read(filp, data, count, offset);
699}
700
701/**
702 * v9fs_mmap_file_read - read from a file
703 * @filp: file pointer to read
704 * @udata: user data buffer to read data into
705 * @count: size of buffer
706 * @offset: offset at which to read data
707 *
708 */
709static ssize_t
710v9fs_mmap_file_read(struct file *filp, char __user *data, size_t count,
711		      loff_t *offset)
712{
713	/* TODO: Check if there are dirty pages */
714	return v9fs_file_read(filp, data, count, offset);
715}
716
717static ssize_t
718v9fs_direct_write(struct file *filp, const char __user * data,
719		  size_t count, loff_t *offsetp)
720{
721	loff_t offset;
722	ssize_t retval;
723	struct inode *inode;
724	struct address_space *mapping;
725
726	offset = *offsetp;
727	mapping = filp->f_mapping;
728	inode = mapping->host;
729	if (!count)
730		return 0;
731
732	mutex_lock(&inode->i_mutex);
733	retval = filemap_write_and_wait_range(mapping, offset,
734					      offset + count - 1);
735	if (retval)
736		goto err_out;
737	/*
738	 * After a write we want buffered reads to be sure to go to disk to get
739	 * the new data.  We invalidate clean cached page from the region we're
740	 * about to write.  We do this *before* the write so that if we fail
741	 * here we fall back to buffered write
742	 */
743	if (mapping->nrpages) {
744		pgoff_t pg_start = offset >> PAGE_CACHE_SHIFT;
745		pgoff_t pg_end   = (offset + count - 1) >> PAGE_CACHE_SHIFT;
746
747		retval = invalidate_inode_pages2_range(mapping,
748							pg_start, pg_end);
749		/*
750		 * If a page can not be invalidated, fall back
751		 * to buffered write.
752		 */
753		if (retval) {
754			if (retval == -EBUSY)
755				goto buff_write;
756			goto err_out;
757		}
758	}
759	retval = v9fs_file_write(filp, data, count, offsetp);
760err_out:
761	mutex_unlock(&inode->i_mutex);
762	return retval;
763
764buff_write:
765	mutex_unlock(&inode->i_mutex);
766	return do_sync_write(filp, data, count, offsetp);
767}
768
769/**
770 * v9fs_cached_file_write - write to a file
771 * @filp: file pointer to write
772 * @data: data buffer to write data from
773 * @count: size of buffer
774 * @offset: offset at which to write data
775 *
776 */
777static ssize_t
778v9fs_cached_file_write(struct file *filp, const char __user * data,
779		       size_t count, loff_t *offset)
780{
781
782	if (filp->f_flags & O_DIRECT)
783		return v9fs_direct_write(filp, data, count, offset);
784	return do_sync_write(filp, data, count, offset);
785}
786
787
788/**
789 * v9fs_mmap_file_write - write to a file
790 * @filp: file pointer to write
791 * @data: data buffer to write data from
792 * @count: size of buffer
793 * @offset: offset at which to write data
794 *
795 */
796static ssize_t
797v9fs_mmap_file_write(struct file *filp, const char __user *data,
798		       size_t count, loff_t *offset)
799{
800	/*
801	 * TODO: invalidate mmaps on filp's inode between
802	 * offset and offset+count
803	 */
804	return v9fs_file_write(filp, data, count, offset);
805}
806
807static void v9fs_mmap_vm_close(struct vm_area_struct *vma)
808{
809	struct inode *inode;
810
811	struct writeback_control wbc = {
812		.nr_to_write = LONG_MAX,
813		.sync_mode = WB_SYNC_ALL,
814		.range_start = vma->vm_pgoff * PAGE_SIZE,
815		 /* absolute end, byte at end included */
816		.range_end = vma->vm_pgoff * PAGE_SIZE +
817			(vma->vm_end - vma->vm_start - 1),
818	};
819
820
821	p9_debug(P9_DEBUG_VFS, "9p VMA close, %p, flushing", vma);
822
823	inode = file_inode(vma->vm_file);
824
825	if (!mapping_cap_writeback_dirty(inode->i_mapping))
826		wbc.nr_to_write = 0;
827
828	might_sleep();
829	sync_inode(inode, &wbc);
830}
831
832
833static const struct vm_operations_struct v9fs_file_vm_ops = {
834	.fault = filemap_fault,
835	.map_pages = filemap_map_pages,
836	.page_mkwrite = v9fs_vm_page_mkwrite,
837	.remap_pages = generic_file_remap_pages,
838};
839
840static const struct vm_operations_struct v9fs_mmap_file_vm_ops = {
841	.close = v9fs_mmap_vm_close,
842	.fault = filemap_fault,
843	.map_pages = filemap_map_pages,
844	.page_mkwrite = v9fs_vm_page_mkwrite,
845	.remap_pages = generic_file_remap_pages,
846};
847
848
849const struct file_operations v9fs_cached_file_operations = {
850	.llseek = generic_file_llseek,
851	.read = v9fs_cached_file_read,
852	.write = v9fs_cached_file_write,
853	.aio_read = generic_file_aio_read,
854	.aio_write = generic_file_aio_write,
855	.open = v9fs_file_open,
856	.release = v9fs_dir_release,
857	.lock = v9fs_file_lock,
858	.mmap = v9fs_file_mmap,
859	.fsync = v9fs_file_fsync,
860};
861
862const struct file_operations v9fs_cached_file_operations_dotl = {
863	.llseek = generic_file_llseek,
864	.read = v9fs_cached_file_read,
865	.write = v9fs_cached_file_write,
866	.aio_read = generic_file_aio_read,
867	.aio_write = generic_file_aio_write,
868	.open = v9fs_file_open,
869	.release = v9fs_dir_release,
870	.lock = v9fs_file_lock_dotl,
871	.flock = v9fs_file_flock_dotl,
872	.mmap = v9fs_file_mmap,
873	.fsync = v9fs_file_fsync_dotl,
874};
875
876const struct file_operations v9fs_file_operations = {
877	.llseek = generic_file_llseek,
878	.read = v9fs_file_read,
879	.write = v9fs_file_write,
880	.open = v9fs_file_open,
881	.release = v9fs_dir_release,
882	.lock = v9fs_file_lock,
883	.mmap = generic_file_readonly_mmap,
884	.fsync = v9fs_file_fsync,
885};
886
887const struct file_operations v9fs_file_operations_dotl = {
888	.llseek = generic_file_llseek,
889	.read = v9fs_file_read,
890	.write = v9fs_file_write,
891	.open = v9fs_file_open,
892	.release = v9fs_dir_release,
893	.lock = v9fs_file_lock_dotl,
894	.flock = v9fs_file_flock_dotl,
895	.mmap = generic_file_readonly_mmap,
896	.fsync = v9fs_file_fsync_dotl,
897};
898
899const struct file_operations v9fs_mmap_file_operations = {
900	.llseek = generic_file_llseek,
901	.read = v9fs_mmap_file_read,
902	.write = v9fs_mmap_file_write,
903	.open = v9fs_file_open,
904	.release = v9fs_dir_release,
905	.lock = v9fs_file_lock,
906	.mmap = v9fs_mmap_file_mmap,
907	.fsync = v9fs_file_fsync,
908};
909
910const struct file_operations v9fs_mmap_file_operations_dotl = {
911	.llseek = generic_file_llseek,
912	.read = v9fs_mmap_file_read,
913	.write = v9fs_mmap_file_write,
914	.open = v9fs_file_open,
915	.release = v9fs_dir_release,
916	.lock = v9fs_file_lock_dotl,
917	.flock = v9fs_file_flock_dotl,
918	.mmap = v9fs_mmap_file_mmap,
919	.fsync = v9fs_file_fsync_dotl,
920};
  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 <linux/uaccess.h>
 38#include <linux/idr.h>
 39#include <linux/uio.h>
 40#include <linux/slab.h>
 41#include <net/9p/9p.h>
 42#include <net/9p/client.h>
 43
 44#include "v9fs.h"
 45#include "v9fs_vfs.h"
 46#include "fid.h"
 47#include "cache.h"
 48
 49static const struct vm_operations_struct v9fs_file_vm_ops;
 50static const struct vm_operations_struct v9fs_mmap_file_vm_ops;
 51
 52/**
 53 * v9fs_file_open - open a file (or directory)
 54 * @inode: inode to be opened
 55 * @file: file being opened
 56 *
 57 */
 58
 59int v9fs_file_open(struct inode *inode, struct file *file)
 60{
 61	int err;
 62	struct v9fs_inode *v9inode;
 63	struct v9fs_session_info *v9ses;
 64	struct p9_fid *fid;
 65	int omode;
 66
 67	p9_debug(P9_DEBUG_VFS, "inode: %p file: %p\n", inode, file);
 68	v9inode = V9FS_I(inode);
 69	v9ses = v9fs_inode2v9ses(inode);
 70	if (v9fs_proto_dotl(v9ses))
 71		omode = v9fs_open_to_dotl_flags(file->f_flags);
 72	else
 73		omode = v9fs_uflags2omode(file->f_flags,
 74					v9fs_proto_dotu(v9ses));
 75	fid = file->private_data;
 76	if (!fid) {
 77		fid = v9fs_fid_clone(file_dentry(file));
 78		if (IS_ERR(fid))
 79			return PTR_ERR(fid);
 80
 81		err = p9_client_open(fid, omode);
 82		if (err < 0) {
 83			p9_client_clunk(fid);
 84			return err;
 85		}
 86		if ((file->f_flags & O_APPEND) &&
 87			(!v9fs_proto_dotu(v9ses) && !v9fs_proto_dotl(v9ses)))
 88			generic_file_llseek(file, 0, SEEK_END);
 89	}
 90
 91	file->private_data = fid;
 92	mutex_lock(&v9inode->v_mutex);
 93	if ((v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) &&
 94	    !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_dentry(file));
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	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
113		v9fs_cache_inode_set_cookie(inode, file);
114	return 0;
115out_error:
116	p9_client_clunk(file->private_data);
117	file->private_data = NULL;
118	return err;
119}
120
121/**
122 * v9fs_file_lock - lock a file (or directory)
123 * @filp: file to be locked
124 * @cmd: lock command
125 * @fl: file lock structure
126 *
127 * Bugs: this looks like a local only lock, we should extend into 9P
128 *       by using open exclusive
129 */
130
131static int v9fs_file_lock(struct file *filp, int cmd, struct file_lock *fl)
132{
133	int res = 0;
134	struct inode *inode = file_inode(filp);
135
136	p9_debug(P9_DEBUG_VFS, "filp: %p lock: %p\n", filp, fl);
137
138	/* No mandatory locks */
139	if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK)
140		return -ENOLCK;
141
142	if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
143		filemap_write_and_wait(inode->i_mapping);
144		invalidate_mapping_pages(&inode->i_data, 0, -1);
145	}
146
147	return res;
148}
149
150static int v9fs_file_do_lock(struct file *filp, int cmd, struct file_lock *fl)
151{
152	struct p9_flock flock;
153	struct p9_fid *fid;
154	uint8_t status = P9_LOCK_ERROR;
155	int res = 0;
156	unsigned char fl_type;
157
158	fid = filp->private_data;
159	BUG_ON(fid == NULL);
160
161	if ((fl->fl_flags & FL_POSIX) != FL_POSIX)
162		BUG();
163
164	res = locks_lock_file_wait(filp, fl);
165	if (res < 0)
166		goto out;
167
168	/* convert posix lock to p9 tlock args */
169	memset(&flock, 0, sizeof(flock));
170	/* map the lock type */
171	switch (fl->fl_type) {
172	case F_RDLCK:
173		flock.type = P9_LOCK_TYPE_RDLCK;
174		break;
175	case F_WRLCK:
176		flock.type = P9_LOCK_TYPE_WRLCK;
177		break;
178	case F_UNLCK:
179		flock.type = P9_LOCK_TYPE_UNLCK;
180		break;
181	}
182	flock.start = fl->fl_start;
183	if (fl->fl_end == OFFSET_MAX)
184		flock.length = 0;
185	else
186		flock.length = fl->fl_end - fl->fl_start + 1;
187	flock.proc_id = fl->fl_pid;
188	flock.client_id = fid->clnt->name;
189	if (IS_SETLKW(cmd))
190		flock.flags = P9_LOCK_FLAGS_BLOCK;
191
192	/*
193	 * if its a blocked request and we get P9_LOCK_BLOCKED as the status
194	 * for lock request, keep on trying
195	 */
196	for (;;) {
197		res = p9_client_lock_dotl(fid, &flock, &status);
198		if (res < 0)
199			goto out_unlock;
200
201		if (status != P9_LOCK_BLOCKED)
202			break;
203		if (status == P9_LOCK_BLOCKED && !IS_SETLKW(cmd))
204			break;
205		if (schedule_timeout_interruptible(P9_LOCK_TIMEOUT) != 0)
206			break;
207	}
208
209	/* map 9p status to VFS status */
210	switch (status) {
211	case P9_LOCK_SUCCESS:
212		res = 0;
213		break;
214	case P9_LOCK_BLOCKED:
215		res = -EAGAIN;
216		break;
217	default:
218		WARN_ONCE(1, "unknown lock status code: %d\n", status);
219		/* fallthough */
220	case P9_LOCK_ERROR:
221	case P9_LOCK_GRACE:
222		res = -ENOLCK;
223		break;
 
 
224	}
225
226out_unlock:
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		/* Even if this fails we want to return the remote error */
235		locks_lock_file_wait(filp, fl);
236		fl->fl_type = fl_type;
237	}
238out:
239	return res;
240}
241
242static int v9fs_file_getlock(struct file *filp, struct file_lock *fl)
243{
244	struct p9_getlock glock;
245	struct p9_fid *fid;
246	int res = 0;
247
248	fid = filp->private_data;
249	BUG_ON(fid == NULL);
250
251	posix_test_lock(filp, fl);
252	/*
253	 * if we have a conflicting lock locally, no need to validate
254	 * with server
255	 */
256	if (fl->fl_type != F_UNLCK)
257		return res;
258
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)
264		glock.length = 0;
265	else
266		glock.length = fl->fl_end - fl->fl_start + 1;
267	glock.proc_id = fl->fl_pid;
268	glock.client_id = fid->clnt->name;
269
270	res = p9_client_getlock_dotl(fid, &glock);
271	if (res < 0)
272		return res;
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;
277		break;
278	case P9_LOCK_TYPE_WRLCK:
279		fl->fl_type = F_WRLCK;
280		break;
281	case P9_LOCK_TYPE_UNLCK:
282		fl->fl_type = F_UNLCK;
283		break;
284	}
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;
289		else
290			fl->fl_end = glock.start + glock.length - 1;
291		fl->fl_pid = -glock.proc_id;
292	}
293	kfree(glock.client_id);
294	return res;
295}
296
297/**
298 * v9fs_file_lock_dotl - lock a file (or directory)
299 * @filp: file to be locked
300 * @cmd: lock command
301 * @fl: file lock structure
302 *
303 */
304
305static int v9fs_file_lock_dotl(struct file *filp, int cmd, struct file_lock *fl)
306{
307	struct inode *inode = file_inode(filp);
308	int ret = -ENOLCK;
309
310	p9_debug(P9_DEBUG_VFS, "filp: %p cmd:%d lock: %p name: %pD\n",
311		 filp, cmd, fl, filp);
312
313	/* No mandatory locks */
314	if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK)
315		goto out_err;
316
317	if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
318		filemap_write_and_wait(inode->i_mapping);
319		invalidate_mapping_pages(&inode->i_data, 0, -1);
320	}
321
322	if (IS_SETLK(cmd) || IS_SETLKW(cmd))
323		ret = v9fs_file_do_lock(filp, cmd, fl);
324	else if (IS_GETLK(cmd))
325		ret = v9fs_file_getlock(filp, fl);
326	else
327		ret = -EINVAL;
328out_err:
329	return ret;
330}
331
332/**
333 * v9fs_file_flock_dotl - lock a file
334 * @filp: file to be locked
335 * @cmd: lock command
336 * @fl: file lock structure
337 *
338 */
339
340static int v9fs_file_flock_dotl(struct file *filp, int cmd,
341	struct file_lock *fl)
342{
343	struct inode *inode = file_inode(filp);
344	int ret = -ENOLCK;
345
346	p9_debug(P9_DEBUG_VFS, "filp: %p cmd:%d lock: %p name: %pD\n",
347		 filp, cmd, fl, filp);
348
349	/* No mandatory locks */
350	if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK)
351		goto out_err;
352
353	if (!(fl->fl_flags & FL_FLOCK))
354		goto out_err;
355
356	if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
357		filemap_write_and_wait(inode->i_mapping);
358		invalidate_mapping_pages(&inode->i_data, 0, -1);
359	}
360	/* Convert flock to posix lock */
 
 
 
361	fl->fl_flags |= FL_POSIX;
362	fl->fl_flags ^= FL_FLOCK;
363
364	if (IS_SETLK(cmd) | IS_SETLKW(cmd))
365		ret = v9fs_file_do_lock(filp, cmd, fl);
366	else
367		ret = -EINVAL;
368out_err:
369	return ret;
370}
371
372/**
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
373 * v9fs_file_read - read from a file
374 * @filp: file pointer to read
375 * @udata: user data buffer to read data into
376 * @count: size of buffer
377 * @offset: offset at which to read data
378 *
379 */
380
381static ssize_t
382v9fs_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
 
383{
384	struct p9_fid *fid = iocb->ki_filp->private_data;
385	int ret, err = 0;
 
386
387	p9_debug(P9_DEBUG_VFS, "count %zu offset %lld\n",
388		 iov_iter_count(to), iocb->ki_pos);
 
 
 
 
 
 
389
390	ret = p9_client_read(fid, iocb->ki_pos, to, &err);
391	if (!ret)
392		return err;
393
394	iocb->ki_pos += ret;
395	return ret;
396}
397
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
398/**
399 * v9fs_file_write - write to a file
400 * @filp: file pointer to write
401 * @data: data buffer to write data from
402 * @count: size of buffer
403 * @offset: offset at which to write data
404 *
405 */
406static ssize_t
407v9fs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
 
408{
409	struct file *file = iocb->ki_filp;
410	ssize_t retval;
411	loff_t origin;
412	int err = 0;
 
 
 
413
414	retval = generic_write_checks(iocb, from);
415	if (retval <= 0)
416		return retval;
 
 
 
417
418	origin = iocb->ki_pos;
419	retval = p9_client_write(file->private_data, iocb->ki_pos, from, &err);
420	if (retval > 0) {
421		struct inode *inode = file_inode(file);
422		loff_t i_size;
423		unsigned long pg_start, pg_end;
424		pg_start = origin >> PAGE_SHIFT;
425		pg_end = (origin + retval - 1) >> PAGE_SHIFT;
426		if (inode->i_mapping && inode->i_mapping->nrpages)
427			invalidate_inode_pages2_range(inode->i_mapping,
428						      pg_start, pg_end);
429		iocb->ki_pos += retval;
430		i_size = i_size_read(inode);
431		if (iocb->ki_pos > i_size) {
432			inode_add_bytes(inode, iocb->ki_pos - i_size);
433			i_size_write(inode, iocb->ki_pos);
434		}
435		return retval;
436	}
437	return err;
438}
439
 
440static int v9fs_file_fsync(struct file *filp, loff_t start, loff_t end,
441			   int datasync)
442{
443	struct p9_fid *fid;
444	struct inode *inode = filp->f_mapping->host;
445	struct p9_wstat wstat;
446	int retval;
447
448	retval = file_write_and_wait_range(filp, start, end);
449	if (retval)
450		return retval;
451
452	inode_lock(inode);
453	p9_debug(P9_DEBUG_VFS, "filp %p datasync %x\n", filp, datasync);
454
455	fid = filp->private_data;
456	v9fs_blank_wstat(&wstat);
457
458	retval = p9_client_wstat(fid, &wstat);
459	inode_unlock(inode);
460
461	return retval;
462}
463
464int v9fs_file_fsync_dotl(struct file *filp, loff_t start, loff_t end,
465			 int datasync)
466{
467	struct p9_fid *fid;
468	struct inode *inode = filp->f_mapping->host;
469	int retval;
470
471	retval = file_write_and_wait_range(filp, start, end);
472	if (retval)
473		return retval;
474
475	inode_lock(inode);
476	p9_debug(P9_DEBUG_VFS, "filp %p datasync %x\n", filp, datasync);
477
478	fid = filp->private_data;
479
480	retval = p9_client_fsync(fid, datasync);
481	inode_unlock(inode);
482
483	return retval;
484}
485
486static int
487v9fs_file_mmap(struct file *filp, struct vm_area_struct *vma)
488{
489	int retval;
490
491
492	retval = generic_file_mmap(filp, vma);
493	if (!retval)
494		vma->vm_ops = &v9fs_file_vm_ops;
495
496	return retval;
497}
498
499static int
500v9fs_mmap_file_mmap(struct file *filp, struct vm_area_struct *vma)
501{
502	int retval;
503	struct inode *inode;
504	struct v9fs_inode *v9inode;
505	struct p9_fid *fid;
506
507	inode = file_inode(filp);
508	v9inode = V9FS_I(inode);
509	mutex_lock(&v9inode->v_mutex);
510	if (!v9inode->writeback_fid &&
511	    (vma->vm_flags & VM_WRITE)) {
512		/*
513		 * clone a fid and add it to writeback_fid
514		 * we do it during mmap instead of
515		 * page dirty time via write_begin/page_mkwrite
516		 * because we want write after unlink usecase
517		 * to work.
518		 */
519		fid = v9fs_writeback_fid(file_dentry(filp));
520		if (IS_ERR(fid)) {
521			retval = PTR_ERR(fid);
522			mutex_unlock(&v9inode->v_mutex);
523			return retval;
524		}
525		v9inode->writeback_fid = (void *) fid;
526	}
527	mutex_unlock(&v9inode->v_mutex);
528
529	retval = generic_file_mmap(filp, vma);
530	if (!retval)
531		vma->vm_ops = &v9fs_mmap_file_vm_ops;
532
533	return retval;
534}
535
536static int
537v9fs_vm_page_mkwrite(struct vm_fault *vmf)
538{
539	struct v9fs_inode *v9inode;
540	struct page *page = vmf->page;
541	struct file *filp = vmf->vma->vm_file;
542	struct inode *inode = file_inode(filp);
543
544
545	p9_debug(P9_DEBUG_VFS, "page %p fid %lx\n",
546		 page, (unsigned long)filp->private_data);
547
548	/* Update file times before taking page lock */
549	file_update_time(filp);
550
551	v9inode = V9FS_I(inode);
552	/* make sure the cache has finished storing the page */
553	v9fs_fscache_wait_on_page_write(inode, page);
554	BUG_ON(!v9inode->writeback_fid);
555	lock_page(page);
556	if (page->mapping != inode->i_mapping)
557		goto out_unlock;
558	wait_for_stable_page(page);
559
560	return VM_FAULT_LOCKED;
561out_unlock:
562	unlock_page(page);
563	return VM_FAULT_NOPAGE;
564}
565
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
566/**
567 * v9fs_mmap_file_read - read from a file
568 * @filp: file pointer to read
569 * @data: user data buffer to read data into
570 * @count: size of buffer
571 * @offset: offset at which to read data
572 *
573 */
574static ssize_t
575v9fs_mmap_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
 
576{
577	/* TODO: Check if there are dirty pages */
578	return v9fs_file_read_iter(iocb, to);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
579}
580
581/**
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
582 * v9fs_mmap_file_write - write to a file
583 * @filp: file pointer to write
584 * @data: data buffer to write data from
585 * @count: size of buffer
586 * @offset: offset at which to write data
587 *
588 */
589static ssize_t
590v9fs_mmap_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
 
591{
592	/*
593	 * TODO: invalidate mmaps on filp's inode between
594	 * offset and offset+count
595	 */
596	return v9fs_file_write_iter(iocb, from);
597}
598
599static void v9fs_mmap_vm_close(struct vm_area_struct *vma)
600{
601	struct inode *inode;
602
603	struct writeback_control wbc = {
604		.nr_to_write = LONG_MAX,
605		.sync_mode = WB_SYNC_ALL,
606		.range_start = vma->vm_pgoff * PAGE_SIZE,
607		 /* absolute end, byte at end included */
608		.range_end = vma->vm_pgoff * PAGE_SIZE +
609			(vma->vm_end - vma->vm_start - 1),
610	};
611
612
613	p9_debug(P9_DEBUG_VFS, "9p VMA close, %p, flushing", vma);
614
615	inode = file_inode(vma->vm_file);
616
617	if (!mapping_cap_writeback_dirty(inode->i_mapping))
618		wbc.nr_to_write = 0;
619
620	might_sleep();
621	sync_inode(inode, &wbc);
622}
623
624
625static const struct vm_operations_struct v9fs_file_vm_ops = {
626	.fault = filemap_fault,
627	.map_pages = filemap_map_pages,
628	.page_mkwrite = v9fs_vm_page_mkwrite,
 
629};
630
631static const struct vm_operations_struct v9fs_mmap_file_vm_ops = {
632	.close = v9fs_mmap_vm_close,
633	.fault = filemap_fault,
634	.map_pages = filemap_map_pages,
635	.page_mkwrite = v9fs_vm_page_mkwrite,
 
636};
637
638
639const struct file_operations v9fs_cached_file_operations = {
640	.llseek = generic_file_llseek,
641	.read_iter = generic_file_read_iter,
642	.write_iter = generic_file_write_iter,
 
 
643	.open = v9fs_file_open,
644	.release = v9fs_dir_release,
645	.lock = v9fs_file_lock,
646	.mmap = v9fs_file_mmap,
647	.fsync = v9fs_file_fsync,
648};
649
650const struct file_operations v9fs_cached_file_operations_dotl = {
651	.llseek = generic_file_llseek,
652	.read_iter = generic_file_read_iter,
653	.write_iter = generic_file_write_iter,
 
 
654	.open = v9fs_file_open,
655	.release = v9fs_dir_release,
656	.lock = v9fs_file_lock_dotl,
657	.flock = v9fs_file_flock_dotl,
658	.mmap = v9fs_file_mmap,
659	.fsync = v9fs_file_fsync_dotl,
660};
661
662const struct file_operations v9fs_file_operations = {
663	.llseek = generic_file_llseek,
664	.read_iter = v9fs_file_read_iter,
665	.write_iter = v9fs_file_write_iter,
666	.open = v9fs_file_open,
667	.release = v9fs_dir_release,
668	.lock = v9fs_file_lock,
669	.mmap = generic_file_readonly_mmap,
670	.fsync = v9fs_file_fsync,
671};
672
673const struct file_operations v9fs_file_operations_dotl = {
674	.llseek = generic_file_llseek,
675	.read_iter = v9fs_file_read_iter,
676	.write_iter = v9fs_file_write_iter,
677	.open = v9fs_file_open,
678	.release = v9fs_dir_release,
679	.lock = v9fs_file_lock_dotl,
680	.flock = v9fs_file_flock_dotl,
681	.mmap = generic_file_readonly_mmap,
682	.fsync = v9fs_file_fsync_dotl,
683};
684
685const struct file_operations v9fs_mmap_file_operations = {
686	.llseek = generic_file_llseek,
687	.read_iter = v9fs_mmap_file_read_iter,
688	.write_iter = v9fs_mmap_file_write_iter,
689	.open = v9fs_file_open,
690	.release = v9fs_dir_release,
691	.lock = v9fs_file_lock,
692	.mmap = v9fs_mmap_file_mmap,
693	.fsync = v9fs_file_fsync,
694};
695
696const struct file_operations v9fs_mmap_file_operations_dotl = {
697	.llseek = generic_file_llseek,
698	.read_iter = v9fs_mmap_file_read_iter,
699	.write_iter = v9fs_mmap_file_write_iter,
700	.open = v9fs_file_open,
701	.release = v9fs_dir_release,
702	.lock = v9fs_file_lock_dotl,
703	.flock = v9fs_file_flock_dotl,
704	.mmap = v9fs_mmap_file_mmap,
705	.fsync = v9fs_file_fsync_dotl,
706};