vfs_file.c 21.3 KB
Newer Older
1 2 3 4 5 6 7 8 9
/*
 *  linux/fs/9p/vfs_file.c
 *
 * This file contians vfs file ops for 9P2000.
 *
 *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
 *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
 *
 *  This program is free software; you can redistribute it and/or modify
10 11
 *  it under the terms of the GNU General Public License version 2
 *  as published by the Free Software Foundation.
12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to:
 *  Free Software Foundation
 *  51 Franklin Street, Fifth Floor
 *  Boston, MA  02111-1301  USA
 *
 */

#include <linux/module.h>
#include <linux/errno.h>
#include <linux/fs.h>
29
#include <linux/sched.h>
30 31 32 33 34
#include <linux/file.h>
#include <linux/stat.h>
#include <linux/string.h>
#include <linux/inet.h>
#include <linux/list.h>
35
#include <linux/pagemap.h>
M
M. Mohan Kumar 已提交
36
#include <linux/utsname.h>
37 38
#include <asm/uaccess.h>
#include <linux/idr.h>
39
#include <linux/uio.h>
40 41
#include <net/9p/9p.h>
#include <net/9p/client.h>
42 43 44 45

#include "v9fs.h"
#include "v9fs_vfs.h"
#include "fid.h"
46
#include "cache.h"
47

48
static const struct vm_operations_struct v9fs_file_vm_ops;
49
static const struct vm_operations_struct v9fs_mmap_file_vm_ops;
50

51 52 53 54 55 56 57 58 59
/**
 * v9fs_file_open - open a file (or directory)
 * @inode: inode to be opened
 * @file: file being opened
 *
 */

int v9fs_file_open(struct inode *inode, struct file *file)
{
60
	int err;
61
	struct v9fs_inode *v9inode;
62 63 64
	struct v9fs_session_info *v9ses;
	struct p9_fid *fid;
	int omode;
65

66
	p9_debug(P9_DEBUG_VFS, "inode: %p file: %p\n", inode, file);
67
	v9inode = V9FS_I(inode);
68
	v9ses = v9fs_inode2v9ses(inode);
M
M. Mohan Kumar 已提交
69
	if (v9fs_proto_dotl(v9ses))
70
		omode = v9fs_open_to_dotl_flags(file->f_flags);
M
M. Mohan Kumar 已提交
71 72 73
	else
		omode = v9fs_uflags2omode(file->f_flags,
					v9fs_proto_dotu(v9ses));
74 75 76 77 78 79 80
	fid = file->private_data;
	if (!fid) {
		fid = v9fs_fid_clone(file->f_path.dentry);
		if (IS_ERR(fid))
			return PTR_ERR(fid);

		err = p9_client_open(fid, omode);
81
		if (err < 0) {
82 83 84
			p9_client_clunk(fid);
			return err;
		}
M
M. Mohan Kumar 已提交
85 86
		if ((file->f_flags & O_APPEND) &&
			(!v9fs_proto_dotu(v9ses) && !v9fs_proto_dotl(v9ses)))
87
			generic_file_llseek(file, 0, SEEK_END);
88
	}
89

90
	file->private_data = fid;
91
	mutex_lock(&v9inode->v_mutex);
92 93
	if ((v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) &&
	    !v9inode->writeback_fid &&
94
	    ((file->f_flags & O_ACCMODE) != O_RDONLY)) {
95
		/*
96
		 * clone a fid and add it to writeback_fid
97 98 99 100 101 102 103 104
		 * we do it during open time instead of
		 * page dirty time via write_begin/page_mkwrite
		 * because we want write after unlink usecase
		 * to work.
		 */
		fid = v9fs_writeback_fid(file->f_path.dentry);
		if (IS_ERR(fid)) {
			err = PTR_ERR(fid);
105
			mutex_unlock(&v9inode->v_mutex);
106 107
			goto out_error;
		}
108
		v9inode->writeback_fid = (void *) fid;
109
	}
110
	mutex_unlock(&v9inode->v_mutex);
111
	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
112
		v9fs_cache_inode_set_cookie(inode, file);
113
	return 0;
114 115 116 117
out_error:
	p9_client_clunk(file->private_data);
	file->private_data = NULL;
	return err;
118 119 120 121
}

/**
 * v9fs_file_lock - lock a file (or directory)
E
Eric Van Hensbergen 已提交
122 123 124
 * @filp: file to be locked
 * @cmd: lock command
 * @fl: file lock structure
125
 *
E
Eric Van Hensbergen 已提交
126
 * Bugs: this looks like a local only lock, we should extend into 9P
127 128 129 130 131 132
 *       by using open exclusive
 */

static int v9fs_file_lock(struct file *filp, int cmd, struct file_lock *fl)
{
	int res = 0;
A
Al Viro 已提交
133
	struct inode *inode = file_inode(filp);
134

135
	p9_debug(P9_DEBUG_VFS, "filp: %p lock: %p\n", filp, fl);
136 137

	/* No mandatory locks */
138
	if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK)
139 140 141
		return -ENOLCK;

	if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
142
		filemap_write_and_wait(inode->i_mapping);
143
		invalidate_mapping_pages(&inode->i_data, 0, -1);
144 145 146 147 148
	}

	return res;
}

M
M. Mohan Kumar 已提交
149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168
static int v9fs_file_do_lock(struct file *filp, int cmd, struct file_lock *fl)
{
	struct p9_flock flock;
	struct p9_fid *fid;
	uint8_t status;
	int res = 0;
	unsigned char fl_type;

	fid = filp->private_data;
	BUG_ON(fid == NULL);

	if ((fl->fl_flags & FL_POSIX) != FL_POSIX)
		BUG();

	res = posix_lock_file_wait(filp, fl);
	if (res < 0)
		goto out;

	/* convert posix lock to p9 tlock args */
	memset(&flock, 0, sizeof(flock));
169 170 171 172 173 174 175 176 177 178 179 180
	/* map the lock type */
	switch (fl->fl_type) {
	case F_RDLCK:
		flock.type = P9_LOCK_TYPE_RDLCK;
		break;
	case F_WRLCK:
		flock.type = P9_LOCK_TYPE_WRLCK;
		break;
	case F_UNLCK:
		flock.type = P9_LOCK_TYPE_UNLCK;
		break;
	}
M
M. Mohan Kumar 已提交
181 182 183 184 185 186
	flock.start = fl->fl_start;
	if (fl->fl_end == OFFSET_MAX)
		flock.length = 0;
	else
		flock.length = fl->fl_end - fl->fl_start + 1;
	flock.proc_id = fl->fl_pid;
187
	flock.client_id = fid->clnt->name;
M
M. Mohan Kumar 已提交
188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203
	if (IS_SETLKW(cmd))
		flock.flags = P9_LOCK_FLAGS_BLOCK;

	/*
	 * if its a blocked request and we get P9_LOCK_BLOCKED as the status
	 * for lock request, keep on trying
	 */
	for (;;) {
		res = p9_client_lock_dotl(fid, &flock, &status);
		if (res < 0)
			break;

		if (status != P9_LOCK_BLOCKED)
			break;
		if (status == P9_LOCK_BLOCKED && !IS_SETLKW(cmd))
			break;
204 205
		if (schedule_timeout_interruptible(P9_LOCK_TIMEOUT) != 0)
			break;
M
M. Mohan Kumar 已提交
206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237
	}

	/* map 9p status to VFS status */
	switch (status) {
	case P9_LOCK_SUCCESS:
		res = 0;
		break;
	case P9_LOCK_BLOCKED:
		res = -EAGAIN;
		break;
	case P9_LOCK_ERROR:
	case P9_LOCK_GRACE:
		res = -ENOLCK;
		break;
	default:
		BUG();
	}

	/*
	 * incase server returned error for lock request, revert
	 * it locally
	 */
	if (res < 0 && fl->fl_type != F_UNLCK) {
		fl_type = fl->fl_type;
		fl->fl_type = F_UNLCK;
		res = posix_lock_file_wait(filp, fl);
		fl->fl_type = fl_type;
	}
out:
	return res;
}

M
M. Mohan Kumar 已提交
238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256
static int v9fs_file_getlock(struct file *filp, struct file_lock *fl)
{
	struct p9_getlock glock;
	struct p9_fid *fid;
	int res = 0;

	fid = filp->private_data;
	BUG_ON(fid == NULL);

	posix_test_lock(filp, fl);
	/*
	 * if we have a conflicting lock locally, no need to validate
	 * with server
	 */
	if (fl->fl_type != F_UNLCK)
		return res;

	/* convert posix lock to p9 tgetlock args */
	memset(&glock, 0, sizeof(glock));
257
	glock.type  = P9_LOCK_TYPE_UNLCK;
M
M. Mohan Kumar 已提交
258 259 260 261 262 263
	glock.start = fl->fl_start;
	if (fl->fl_end == OFFSET_MAX)
		glock.length = 0;
	else
		glock.length = fl->fl_end - fl->fl_start + 1;
	glock.proc_id = fl->fl_pid;
264
	glock.client_id = fid->clnt->name;
M
M. Mohan Kumar 已提交
265 266 267 268

	res = p9_client_getlock_dotl(fid, &glock);
	if (res < 0)
		return res;
269 270 271 272 273 274 275 276 277 278 279 280 281
	/* map 9p lock type to os lock type */
	switch (glock.type) {
	case P9_LOCK_TYPE_RDLCK:
		fl->fl_type = F_RDLCK;
		break;
	case P9_LOCK_TYPE_WRLCK:
		fl->fl_type = F_WRLCK;
		break;
	case P9_LOCK_TYPE_UNLCK:
		fl->fl_type = F_UNLCK;
		break;
	}
	if (glock.type != P9_LOCK_TYPE_UNLCK) {
M
M. Mohan Kumar 已提交
282 283 284 285 286 287
		fl->fl_start = glock.start;
		if (glock.length == 0)
			fl->fl_end = OFFSET_MAX;
		else
			fl->fl_end = glock.start + glock.length - 1;
		fl->fl_pid = glock.proc_id;
288
	}
M
M. Mohan Kumar 已提交
289 290 291
	return res;
}

M
M. Mohan Kumar 已提交
292 293 294 295 296 297 298 299 300 301
/**
 * v9fs_file_lock_dotl - lock a file (or directory)
 * @filp: file to be locked
 * @cmd: lock command
 * @fl: file lock structure
 *
 */

static int v9fs_file_lock_dotl(struct file *filp, int cmd, struct file_lock *fl)
{
A
Al Viro 已提交
302
	struct inode *inode = file_inode(filp);
M
M. Mohan Kumar 已提交
303 304
	int ret = -ENOLCK;

A
Al Viro 已提交
305 306
	p9_debug(P9_DEBUG_VFS, "filp: %p cmd:%d lock: %p name: %pD\n",
		 filp, cmd, fl, filp);
M
M. Mohan Kumar 已提交
307 308 309 310 311 312 313 314 315 316 317 318

	/* No mandatory locks */
	if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK)
		goto out_err;

	if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
		filemap_write_and_wait(inode->i_mapping);
		invalidate_mapping_pages(&inode->i_data, 0, -1);
	}

	if (IS_SETLK(cmd) || IS_SETLKW(cmd))
		ret = v9fs_file_do_lock(filp, cmd, fl);
M
M. Mohan Kumar 已提交
319 320
	else if (IS_GETLK(cmd))
		ret = v9fs_file_getlock(filp, fl);
M
M. Mohan Kumar 已提交
321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337
	else
		ret = -EINVAL;
out_err:
	return ret;
}

/**
 * v9fs_file_flock_dotl - lock a file
 * @filp: file to be locked
 * @cmd: lock command
 * @fl: file lock structure
 *
 */

static int v9fs_file_flock_dotl(struct file *filp, int cmd,
	struct file_lock *fl)
{
A
Al Viro 已提交
338
	struct inode *inode = file_inode(filp);
M
M. Mohan Kumar 已提交
339 340
	int ret = -ENOLCK;

A
Al Viro 已提交
341 342
	p9_debug(P9_DEBUG_VFS, "filp: %p cmd:%d lock: %p name: %pD\n",
		 filp, cmd, fl, filp);
M
M. Mohan Kumar 已提交
343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366

	/* No mandatory locks */
	if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK)
		goto out_err;

	if (!(fl->fl_flags & FL_FLOCK))
		goto out_err;

	if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
		filemap_write_and_wait(inode->i_mapping);
		invalidate_mapping_pages(&inode->i_data, 0, -1);
	}
	/* Convert flock to posix lock */
	fl->fl_flags |= FL_POSIX;
	fl->fl_flags ^= FL_FLOCK;

	if (IS_SETLK(cmd) | IS_SETLKW(cmd))
		ret = v9fs_file_do_lock(filp, cmd, fl);
	else
		ret = -EINVAL;
out_err:
	return ret;
}

367
/**
368 369
 * v9fs_fid_readn - read from a fid
 * @fid: fid to read
370
 * @data: data buffer to read data into
371
 * @udata: user data buffer to read data into
372 373 374 375
 * @count: size of buffer
 * @offset: offset at which to read data
 *
 */
376
ssize_t
377
v9fs_fid_readn(struct p9_fid *fid, char *data, char __user *udata, u32 count,
378 379
	       u64 offset)
{
380
	int n, total, size;
381

382 383
	p9_debug(P9_DEBUG_VFS, "fid %d offset %llu count %d\n",
		 fid->fid, (long long unsigned)offset, count);
384 385
	n = 0;
	total = 0;
386
	size = fid->iounit ? fid->iounit : fid->clnt->msize - P9_IOHDRSZ;
387 388 389 390 391 392 393 394 395 396 397 398 399
	do {
		n = p9_client_read(fid, data, udata, offset, count);
		if (n <= 0)
			break;

		if (data)
			data += n;
		if (udata)
			udata += n;

		offset += n;
		count -= n;
		total += n;
400
	} while (count > 0 && n == size);
401 402 403 404 405 406 407

	if (n < 0)
		total = n;

	return total;
}

408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423
/**
 * v9fs_file_readn - read from a file
 * @filp: file pointer to read
 * @data: data buffer to read data into
 * @udata: user data buffer to read data into
 * @count: size of buffer
 * @offset: offset at which to read data
 *
 */
ssize_t
v9fs_file_readn(struct file *filp, char *data, char __user *udata, u32 count,
	       u64 offset)
{
	return v9fs_fid_readn(filp->private_data, data, udata, count, offset);
}

424 425 426 427 428 429 430 431 432
/**
 * v9fs_file_read - read from a file
 * @filp: file pointer to read
 * @udata: user data buffer to read data into
 * @count: size of buffer
 * @offset: offset at which to read data
 *
 */

433
static ssize_t
434
v9fs_file_read(struct file *filp, char __user *udata, size_t count,
435
	       loff_t * offset)
436
{
437 438
	int ret;
	struct p9_fid *fid;
439
	size_t size;
440

441
	p9_debug(P9_DEBUG_VFS, "count %zu offset %lld\n", count, *offset);
442
	fid = filp->private_data;
443

444 445
	size = fid->iounit ? fid->iounit : fid->clnt->msize - P9_IOHDRSZ;
	if (count > size)
446 447 448 449
		ret = v9fs_file_readn(filp, NULL, udata, count, *offset);
	else
		ret = p9_client_read(fid, NULL, udata, *offset, count);

450 451
	if (ret > 0)
		*offset += ret;
452

453
	return ret;
454 455
}

456 457 458 459
ssize_t
v9fs_file_write_internal(struct inode *inode, struct p9_fid *fid,
			 const char __user *data, size_t count,
			 loff_t *offset, int invalidate)
460
{
461
	loff_t origin = *offset;
462 463 464
	struct iovec iov = {.iov_base = (void __user *)data, .iov_len = count};
	struct iov_iter from;
	int total, err = 0;
465

466 467
	p9_debug(P9_DEBUG_VFS, "data %p count %d offset %x\n",
		 data, (int)count, (int)*offset);
468

469
	iov_iter_init(&from, WRITE, &iov, 1, count);
470

471
	total = p9_client_write(fid, origin, &from, &err);
472
	if (invalidate && (total > 0)) {
473 474
		loff_t i_size;
		unsigned long pg_start, pg_end;
475 476
		pg_start = origin >> PAGE_CACHE_SHIFT;
		pg_end = (origin + total - 1) >> PAGE_CACHE_SHIFT;
477 478 479
		if (inode->i_mapping && inode->i_mapping->nrpages)
			invalidate_inode_pages2_range(inode->i_mapping,
						      pg_start, pg_end);
480
		*offset += total;
481 482 483 484 485
		i_size = i_size_read(inode);
		if (*offset > i_size) {
			inode_add_bytes(inode, *offset - i_size);
			i_size_write(inode, *offset);
		}
486
	}
487
	return total ? total : err;
488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516
}

/**
 * v9fs_file_write - write to a file
 * @filp: file pointer to write
 * @data: data buffer to write data from
 * @count: size of buffer
 * @offset: offset at which to write data
 *
 */
static ssize_t
v9fs_file_write(struct file *filp, const char __user * data,
		size_t count, loff_t *offset)
{
	ssize_t retval = 0;
	loff_t origin = *offset;


	retval = generic_write_checks(filp, &origin, &count, 0);
	if (retval)
		goto out;

	retval = -EINVAL;
	if ((ssize_t) count < 0)
		goto out;
	retval = 0;
	if (!count)
		goto out;

A
Al Viro 已提交
517
	retval = v9fs_file_write_internal(file_inode(filp),
518
					filp->private_data,
519 520 521 522
					data, count, &origin, 1);
	/* update offset on successful write */
	if (retval > 0)
		*offset = origin;
523 524
out:
	return retval;
525 526
}

527

528 529
static int v9fs_file_fsync(struct file *filp, loff_t start, loff_t end,
			   int datasync)
530 531
{
	struct p9_fid *fid;
532
	struct inode *inode = filp->f_mapping->host;
533 534 535
	struct p9_wstat wstat;
	int retval;

536 537 538 539 540
	retval = filemap_write_and_wait_range(inode->i_mapping, start, end);
	if (retval)
		return retval;

	mutex_lock(&inode->i_mutex);
541
	p9_debug(P9_DEBUG_VFS, "filp %p datasync %x\n", filp, datasync);
542 543 544 545 546

	fid = filp->private_data;
	v9fs_blank_wstat(&wstat);

	retval = p9_client_wstat(fid, &wstat);
547 548
	mutex_unlock(&inode->i_mutex);

549 550 551
	return retval;
}

552 553
int v9fs_file_fsync_dotl(struct file *filp, loff_t start, loff_t end,
			 int datasync)
554 555
{
	struct p9_fid *fid;
556
	struct inode *inode = filp->f_mapping->host;
557 558
	int retval;

559 560 561 562 563
	retval = filemap_write_and_wait_range(inode->i_mapping, start, end);
	if (retval)
		return retval;

	mutex_lock(&inode->i_mutex);
564
	p9_debug(P9_DEBUG_VFS, "filp %p datasync %x\n", filp, datasync);
565 566 567

	fid = filp->private_data;

568
	retval = p9_client_fsync(fid, datasync);
569 570
	mutex_unlock(&inode->i_mutex);

571 572 573
	return retval;
}

574
static int
575
v9fs_file_mmap(struct file *filp, struct vm_area_struct *vma)
576 577 578
{
	int retval;

579 580

	retval = generic_file_mmap(filp, vma);
581 582 583 584 585 586
	if (!retval)
		vma->vm_ops = &v9fs_file_vm_ops;

	return retval;
}

587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623
static int
v9fs_mmap_file_mmap(struct file *filp, struct vm_area_struct *vma)
{
	int retval;
	struct inode *inode;
	struct v9fs_inode *v9inode;
	struct p9_fid *fid;

	inode = file_inode(filp);
	v9inode = V9FS_I(inode);
	mutex_lock(&v9inode->v_mutex);
	if (!v9inode->writeback_fid &&
	    (vma->vm_flags & VM_WRITE)) {
		/*
		 * clone a fid and add it to writeback_fid
		 * we do it during mmap instead of
		 * page dirty time via write_begin/page_mkwrite
		 * because we want write after unlink usecase
		 * to work.
		 */
		fid = v9fs_writeback_fid(filp->f_path.dentry);
		if (IS_ERR(fid)) {
			retval = PTR_ERR(fid);
			mutex_unlock(&v9inode->v_mutex);
			return retval;
		}
		v9inode->writeback_fid = (void *) fid;
	}
	mutex_unlock(&v9inode->v_mutex);

	retval = generic_file_mmap(filp, vma);
	if (!retval)
		vma->vm_ops = &v9fs_mmap_file_vm_ops;

	return retval;
}

624 625 626
static int
v9fs_vm_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
{
627
	struct v9fs_inode *v9inode;
628 629
	struct page *page = vmf->page;
	struct file *filp = vma->vm_file;
A
Al Viro 已提交
630
	struct inode *inode = file_inode(filp);
631 632


633 634
	p9_debug(P9_DEBUG_VFS, "page %p fid %lx\n",
		 page, (unsigned long)filp->private_data);
635

636 637 638
	/* Update file times before taking page lock */
	file_update_time(filp);

639
	v9inode = V9FS_I(inode);
640 641
	/* make sure the cache has finished storing the page */
	v9fs_fscache_wait_on_page_write(inode, page);
642
	BUG_ON(!v9inode->writeback_fid);
643 644 645
	lock_page(page);
	if (page->mapping != inode->i_mapping)
		goto out_unlock;
646
	wait_for_stable_page(page);
647 648 649 650 651 652 653

	return VM_FAULT_LOCKED;
out_unlock:
	unlock_page(page);
	return VM_FAULT_NOPAGE;
}

654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677
static ssize_t
v9fs_direct_read(struct file *filp, char __user *udata, size_t count,
		 loff_t *offsetp)
{
	loff_t size, offset;
	struct inode *inode;
	struct address_space *mapping;

	offset = *offsetp;
	mapping = filp->f_mapping;
	inode = mapping->host;
	if (!count)
		return 0;
	size = i_size_read(inode);
	if (offset < size)
		filemap_write_and_wait_range(mapping, offset,
					     offset + count - 1);

	return v9fs_file_read(filp, udata, count, offsetp);
}

/**
 * v9fs_cached_file_read - read from a file
 * @filp: file pointer to read
F
Fabian Frederick 已提交
678
 * @data: user data buffer to read data into
679 680 681 682 683 684 685 686 687 688
 * @count: size of buffer
 * @offset: offset at which to read data
 *
 */
static ssize_t
v9fs_cached_file_read(struct file *filp, char __user *data, size_t count,
		      loff_t *offset)
{
	if (filp->f_flags & O_DIRECT)
		return v9fs_direct_read(filp, data, count, offset);
689
	return new_sync_read(filp, data, count, offset);
690 691
}

692 693 694
/**
 * v9fs_mmap_file_read - read from a file
 * @filp: file pointer to read
F
Fabian Frederick 已提交
695
 * @data: user data buffer to read data into
696 697 698 699 700 701 702 703 704 705 706 707
 * @count: size of buffer
 * @offset: offset at which to read data
 *
 */
static ssize_t
v9fs_mmap_file_read(struct file *filp, char __user *data, size_t count,
		      loff_t *offset)
{
	/* TODO: Check if there are dirty pages */
	return v9fs_file_read(filp, data, count, offset);
}

708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756
static ssize_t
v9fs_direct_write(struct file *filp, const char __user * data,
		  size_t count, loff_t *offsetp)
{
	loff_t offset;
	ssize_t retval;
	struct inode *inode;
	struct address_space *mapping;

	offset = *offsetp;
	mapping = filp->f_mapping;
	inode = mapping->host;
	if (!count)
		return 0;

	mutex_lock(&inode->i_mutex);
	retval = filemap_write_and_wait_range(mapping, offset,
					      offset + count - 1);
	if (retval)
		goto err_out;
	/*
	 * After a write we want buffered reads to be sure to go to disk to get
	 * the new data.  We invalidate clean cached page from the region we're
	 * about to write.  We do this *before* the write so that if we fail
	 * here we fall back to buffered write
	 */
	if (mapping->nrpages) {
		pgoff_t pg_start = offset >> PAGE_CACHE_SHIFT;
		pgoff_t pg_end   = (offset + count - 1) >> PAGE_CACHE_SHIFT;

		retval = invalidate_inode_pages2_range(mapping,
							pg_start, pg_end);
		/*
		 * If a page can not be invalidated, fall back
		 * to buffered write.
		 */
		if (retval) {
			if (retval == -EBUSY)
				goto buff_write;
			goto err_out;
		}
	}
	retval = v9fs_file_write(filp, data, count, offsetp);
err_out:
	mutex_unlock(&inode->i_mutex);
	return retval;

buff_write:
	mutex_unlock(&inode->i_mutex);
757
	return new_sync_write(filp, data, count, offsetp);
758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774
}

/**
 * v9fs_cached_file_write - write to a file
 * @filp: file pointer to write
 * @data: data buffer to write data from
 * @count: size of buffer
 * @offset: offset at which to write data
 *
 */
static ssize_t
v9fs_cached_file_write(struct file *filp, const char __user * data,
		       size_t count, loff_t *offset)
{

	if (filp->f_flags & O_DIRECT)
		return v9fs_direct_write(filp, data, count, offset);
775
	return new_sync_write(filp, data, count, offset);
776 777
}

778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823

/**
 * v9fs_mmap_file_write - write to a file
 * @filp: file pointer to write
 * @data: data buffer to write data from
 * @count: size of buffer
 * @offset: offset at which to write data
 *
 */
static ssize_t
v9fs_mmap_file_write(struct file *filp, const char __user *data,
		       size_t count, loff_t *offset)
{
	/*
	 * TODO: invalidate mmaps on filp's inode between
	 * offset and offset+count
	 */
	return v9fs_file_write(filp, data, count, offset);
}

static void v9fs_mmap_vm_close(struct vm_area_struct *vma)
{
	struct inode *inode;

	struct writeback_control wbc = {
		.nr_to_write = LONG_MAX,
		.sync_mode = WB_SYNC_ALL,
		.range_start = vma->vm_pgoff * PAGE_SIZE,
		 /* absolute end, byte at end included */
		.range_end = vma->vm_pgoff * PAGE_SIZE +
			(vma->vm_end - vma->vm_start - 1),
	};


	p9_debug(P9_DEBUG_VFS, "9p VMA close, %p, flushing", vma);

	inode = file_inode(vma->vm_file);

	if (!mapping_cap_writeback_dirty(inode->i_mapping))
		wbc.nr_to_write = 0;

	might_sleep();
	sync_inode(inode, &wbc);
}


824 825
static const struct vm_operations_struct v9fs_file_vm_ops = {
	.fault = filemap_fault,
826
	.map_pages = filemap_map_pages,
827 828 829
	.page_mkwrite = v9fs_vm_page_mkwrite,
};

830 831 832
static const struct vm_operations_struct v9fs_mmap_file_vm_ops = {
	.close = v9fs_mmap_vm_close,
	.fault = filemap_fault,
833
	.map_pages = filemap_map_pages,
834 835 836
	.page_mkwrite = v9fs_vm_page_mkwrite,
};

837

838
const struct file_operations v9fs_cached_file_operations = {
839
	.llseek = generic_file_llseek,
840 841
	.read = v9fs_cached_file_read,
	.write = v9fs_cached_file_write,
842
	.read_iter = generic_file_read_iter,
843
	.write_iter = generic_file_write_iter,
844 845 846
	.open = v9fs_file_open,
	.release = v9fs_dir_release,
	.lock = v9fs_file_lock,
847
	.mmap = v9fs_file_mmap,
848
	.fsync = v9fs_file_fsync,
849 850
};

851
const struct file_operations v9fs_cached_file_operations_dotl = {
852
	.llseek = generic_file_llseek,
853 854
	.read = v9fs_cached_file_read,
	.write = v9fs_cached_file_write,
855
	.read_iter = generic_file_read_iter,
856
	.write_iter = generic_file_write_iter,
857 858
	.open = v9fs_file_open,
	.release = v9fs_dir_release,
M
M. Mohan Kumar 已提交
859 860
	.lock = v9fs_file_lock_dotl,
	.flock = v9fs_file_flock_dotl,
861
	.mmap = v9fs_file_mmap,
862
	.fsync = v9fs_file_fsync_dotl,
863 864
};

865
const struct file_operations v9fs_file_operations = {
866 867 868 869 870 871
	.llseek = generic_file_llseek,
	.read = v9fs_file_read,
	.write = v9fs_file_write,
	.open = v9fs_file_open,
	.release = v9fs_dir_release,
	.lock = v9fs_file_lock,
872
	.mmap = generic_file_readonly_mmap,
873
	.fsync = v9fs_file_fsync,
874
};
875 876 877 878 879 880 881

const struct file_operations v9fs_file_operations_dotl = {
	.llseek = generic_file_llseek,
	.read = v9fs_file_read,
	.write = v9fs_file_write,
	.open = v9fs_file_open,
	.release = v9fs_dir_release,
M
M. Mohan Kumar 已提交
882 883
	.lock = v9fs_file_lock_dotl,
	.flock = v9fs_file_flock_dotl,
884
	.mmap = generic_file_readonly_mmap,
885
	.fsync = v9fs_file_fsync_dotl,
886
};
887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909

const struct file_operations v9fs_mmap_file_operations = {
	.llseek = generic_file_llseek,
	.read = v9fs_mmap_file_read,
	.write = v9fs_mmap_file_write,
	.open = v9fs_file_open,
	.release = v9fs_dir_release,
	.lock = v9fs_file_lock,
	.mmap = v9fs_mmap_file_mmap,
	.fsync = v9fs_file_fsync,
};

const struct file_operations v9fs_mmap_file_operations_dotl = {
	.llseek = generic_file_llseek,
	.read = v9fs_mmap_file_read,
	.write = v9fs_mmap_file_write,
	.open = v9fs_file_open,
	.release = v9fs_dir_release,
	.lock = v9fs_file_lock_dotl,
	.flock = v9fs_file_flock_dotl,
	.mmap = v9fs_mmap_file_mmap,
	.fsync = v9fs_file_fsync_dotl,
};