file.c 57.3 KB
Newer Older
L
Linus Torvalds 已提交
1 2 3 4
/*
 *   fs/cifs/file.c
 *
 *   vfs operations that deal with files
S
Steve French 已提交
5 6
 *
 *   Copyright (C) International Business Machines  Corp., 2002,2007
L
Linus Torvalds 已提交
7
 *   Author(s): Steve French (sfrench@us.ibm.com)
J
[CIFS]  
Jeremy Allison 已提交
8
 *              Jeremy Allison (jra@samba.org)
L
Linus Torvalds 已提交
9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
 *
 *   This library is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU Lesser General Public License as published
 *   by the Free Software Foundation; either version 2.1 of the License, or
 *   (at your option) any later version.
 *
 *   This library 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 Lesser General Public License for more details.
 *
 *   You should have received a copy of the GNU Lesser General Public License
 *   along with this library; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */
#include <linux/fs.h>
25
#include <linux/backing-dev.h>
L
Linus Torvalds 已提交
26 27 28 29
#include <linux/stat.h>
#include <linux/fcntl.h>
#include <linux/pagemap.h>
#include <linux/pagevec.h>
30
#include <linux/writeback.h>
31
#include <linux/task_io_accounting_ops.h>
32
#include <linux/delay.h>
L
Linus Torvalds 已提交
33 34 35 36 37 38 39 40 41 42 43 44 45 46 47
#include <asm/div64.h>
#include "cifsfs.h"
#include "cifspdu.h"
#include "cifsglob.h"
#include "cifsproto.h"
#include "cifs_unicode.h"
#include "cifs_debug.h"
#include "cifs_fs_sb.h"

static inline struct cifsFileInfo *cifs_init_private(
	struct cifsFileInfo *private_data, struct inode *inode,
	struct file *file, __u16 netfid)
{
	memset(private_data, 0, sizeof(struct cifsFileInfo));
	private_data->netfid = netfid;
S
Steve French 已提交
48
	private_data->pid = current->tgid;
L
Linus Torvalds 已提交
49
	init_MUTEX(&private_data->fh_sem);
50
	mutex_init(&private_data->lock_mutex);
J
[CIFS]  
Jeremy Allison 已提交
51
	INIT_LIST_HEAD(&private_data->llist);
L
Linus Torvalds 已提交
52 53
	private_data->pfile = file; /* needed for writepage */
	private_data->pInode = inode;
54 55
	private_data->invalidHandle = false;
	private_data->closePend = false;
56 57 58 59
	/* we have to track num writers to the inode, since writepages
	does not tell us which handle the write is for so there can
	be a close (overlapping with write) of the filehandle that
	cifs_writepages chose to use */
S
Steve French 已提交
60
	atomic_set(&private_data->wrtPending, 0);
L
Linus Torvalds 已提交
61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77

	return private_data;
}

static inline int cifs_convert_flags(unsigned int flags)
{
	if ((flags & O_ACCMODE) == O_RDONLY)
		return GENERIC_READ;
	else if ((flags & O_ACCMODE) == O_WRONLY)
		return GENERIC_WRITE;
	else if ((flags & O_ACCMODE) == O_RDWR) {
		/* GENERIC_ALL is too much permission to request
		   can cause unnecessary access denied on create */
		/* return GENERIC_ALL; */
		return (GENERIC_READ | GENERIC_WRITE);
	}

78 79 80 81 82
	return (READ_CONTROL | FILE_WRITE_ATTRIBUTES | FILE_READ_ATTRIBUTES |
		FILE_WRITE_EA | FILE_APPEND_DATA | FILE_WRITE_DATA |
		FILE_READ_DATA);


L
Linus Torvalds 已提交
83 84 85 86 87 88 89 90 91 92
}

static inline int cifs_get_disposition(unsigned int flags)
{
	if ((flags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
		return FILE_CREATE;
	else if ((flags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
		return FILE_OVERWRITE_IF;
	else if ((flags & O_CREAT) == O_CREAT)
		return FILE_OPEN_IF;
93 94
	else if ((flags & O_TRUNC) == O_TRUNC)
		return FILE_OVERWRITE;
L
Linus Torvalds 已提交
95 96 97 98 99 100 101 102 103 104 105 106 107 108 109
	else
		return FILE_OPEN;
}

/* all arguments to this function must be checked for validity in caller */
static inline int cifs_open_inode_helper(struct inode *inode, struct file *file,
	struct cifsInodeInfo *pCifsInode, struct cifsFileInfo *pCifsFile,
	struct cifsTconInfo *pTcon, int *oplock, FILE_ALL_INFO *buf,
	char *full_path, int xid)
{
	struct timespec temp;
	int rc;

	/* want handles we can use to read with first
	   in the list so we do not have to walk the
N
Nick Piggin 已提交
110
	   list to search for one in write_begin */
L
Linus Torvalds 已提交
111
	if ((file->f_flags & O_ACCMODE) == O_WRONLY) {
S
Steve French 已提交
112
		list_add_tail(&pCifsFile->flist,
L
Linus Torvalds 已提交
113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128
			      &pCifsInode->openFileList);
	} else {
		list_add(&pCifsFile->flist,
			 &pCifsInode->openFileList);
	}
	write_unlock(&GlobalSMBSeslock);
	if (pCifsInode->clientCanCacheRead) {
		/* we have the inode open somewhere else
		   no need to discard cache data */
		goto client_can_cache;
	}

	/* BB need same check in cifs_create too? */
	/* if not oplocked, invalidate inode pages if mtime or file
	   size changed */
	temp = cifs_NTtimeToUnix(le64_to_cpu(buf->LastWriteTime));
129 130
	if (timespec_equal(&file->f_path.dentry->d_inode->i_mtime, &temp) &&
			   (file->f_path.dentry->d_inode->i_size ==
L
Linus Torvalds 已提交
131 132 133
			    (loff_t)le64_to_cpu(buf->EndOfFile))) {
		cFYI(1, ("inode unchanged on server"));
	} else {
134
		if (file->f_path.dentry->d_inode->i_mapping) {
L
Linus Torvalds 已提交
135 136
		/* BB no need to lock inode until after invalidate
		   since namei code should already have it locked? */
137 138 139
			rc = filemap_write_and_wait(file->f_path.dentry->d_inode->i_mapping);
			if (rc != 0)
				CIFS_I(file->f_path.dentry->d_inode)->write_behind_rc = rc;
L
Linus Torvalds 已提交
140 141 142
		}
		cFYI(1, ("invalidating remote inode since open detected it "
			 "changed"));
143
		invalidate_remote_inode(file->f_path.dentry->d_inode);
L
Linus Torvalds 已提交
144 145 146
	}

client_can_cache:
147
	if (pTcon->unix_ext)
148
		rc = cifs_get_inode_info_unix(&file->f_path.dentry->d_inode,
L
Linus Torvalds 已提交
149 150
			full_path, inode->i_sb, xid);
	else
151
		rc = cifs_get_inode_info(&file->f_path.dentry->d_inode,
152
			full_path, buf, inode->i_sb, xid, NULL);
L
Linus Torvalds 已提交
153 154

	if ((*oplock & 0xF) == OPLOCK_EXCLUSIVE) {
155 156
		pCifsInode->clientCanCacheAll = true;
		pCifsInode->clientCanCacheRead = true;
L
Linus Torvalds 已提交
157
		cFYI(1, ("Exclusive Oplock granted on inode %p",
158
			 file->f_path.dentry->d_inode));
L
Linus Torvalds 已提交
159
	} else if ((*oplock & 0xF) == OPLOCK_READ)
160
		pCifsInode->clientCanCacheRead = true;
L
Linus Torvalds 已提交
161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186

	return rc;
}

int cifs_open(struct inode *inode, struct file *file)
{
	int rc = -EACCES;
	int xid, oplock;
	struct cifs_sb_info *cifs_sb;
	struct cifsTconInfo *pTcon;
	struct cifsFileInfo *pCifsFile;
	struct cifsInodeInfo *pCifsInode;
	struct list_head *tmp;
	char *full_path = NULL;
	int desiredAccess;
	int disposition;
	__u16 netfid;
	FILE_ALL_INFO *buf = NULL;

	xid = GetXid();

	cifs_sb = CIFS_SB(inode->i_sb);
	pTcon = cifs_sb->tcon;

	if (file->f_flags & O_CREAT) {
		/* search inode for this file and fill in file->private_data */
187
		pCifsInode = CIFS_I(file->f_path.dentry->d_inode);
L
Linus Torvalds 已提交
188 189 190 191 192 193 194 195 196 197
		read_lock(&GlobalSMBSeslock);
		list_for_each(tmp, &pCifsInode->openFileList) {
			pCifsFile = list_entry(tmp, struct cifsFileInfo,
					       flist);
			if ((pCifsFile->pfile == NULL) &&
			    (pCifsFile->pid == current->tgid)) {
				/* mode set in cifs_create */

				/* needed for writepage */
				pCifsFile->pfile = file;
198

L
Linus Torvalds 已提交
199 200 201 202 203 204 205 206 207 208 209 210
				file->private_data = pCifsFile;
				break;
			}
		}
		read_unlock(&GlobalSMBSeslock);
		if (file->private_data != NULL) {
			rc = 0;
			FreeXid(xid);
			return rc;
		} else {
			if (file->f_flags & O_EXCL)
				cERROR(1, ("could not find file instance for "
211
					   "new file %p", file));
L
Linus Torvalds 已提交
212 213 214
		}
	}

215
	full_path = build_path_from_dentry(file->f_path.dentry);
L
Linus Torvalds 已提交
216 217 218 219 220
	if (full_path == NULL) {
		FreeXid(xid);
		return -ENOMEM;
	}

221
	cFYI(1, ("inode = 0x%p file flags are 0x%x for %s",
L
Linus Torvalds 已提交
222 223 224 225 226
		 inode, file->f_flags, full_path));
	desiredAccess = cifs_convert_flags(file->f_flags);

/*********************************************************************
 *  open flag mapping table:
S
Steve French 已提交
227
 *
L
Linus Torvalds 已提交
228
 *	POSIX Flag            CIFS Disposition
S
Steve French 已提交
229
 *	----------            ----------------
L
Linus Torvalds 已提交
230 231 232 233 234 235 236
 *	O_CREAT               FILE_OPEN_IF
 *	O_CREAT | O_EXCL      FILE_CREATE
 *	O_CREAT | O_TRUNC     FILE_OVERWRITE_IF
 *	O_TRUNC               FILE_OVERWRITE
 *	none of the above     FILE_OPEN
 *
 *	Note that there is not a direct match between disposition
S
Steve French 已提交
237
 *	FILE_SUPERSEDE (ie create whether or not file exists although
L
Linus Torvalds 已提交
238 239 240 241
 *	O_CREAT | O_TRUNC is similar but truncates the existing
 *	file rather than creating a new file as FILE_SUPERSEDE does
 *	(which uses the attributes / metadata passed in on open call)
 *?
S
Steve French 已提交
242
 *?  O_SYNC is a reasonable match to CIFS writethrough flag
L
Linus Torvalds 已提交
243 244 245 246 247 248 249 250 251 252 253
 *?  and the read write flags match reasonably.  O_LARGEFILE
 *?  is irrelevant because largefile support is always used
 *?  by this client. Flags O_APPEND, O_DIRECT, O_DIRECTORY,
 *	 O_FASYNC, O_NOFOLLOW, O_NONBLOCK need further investigation
 *********************************************************************/

	disposition = cifs_get_disposition(file->f_flags);

	if (oplockEnabled)
		oplock = REQ_OPLOCK;
	else
254
		oplock = 0;
L
Linus Torvalds 已提交
255 256 257 258 259 260 261

	/* BB pass O_SYNC flag through on file attributes .. BB */

	/* Also refresh inode by passing in file_info buf returned by SMBOpen
	   and calling get_inode_info with returned buf (at least helps
	   non-Unix server case) */

S
Steve French 已提交
262 263
	/* BB we can not do this if this is the second open of a file
	   and the first handle has writebehind data, we might be
L
Linus Torvalds 已提交
264 265 266 267 268 269
	   able to simply do a filemap_fdatawrite/filemap_fdatawait first */
	buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
	if (!buf) {
		rc = -ENOMEM;
		goto out;
	}
270 271

	if (cifs_sb->tcon->ses->capabilities & CAP_NT_SMBS)
S
Steve French 已提交
272
		rc = CIFSSMBOpen(xid, pTcon, full_path, disposition,
273
			 desiredAccess, CREATE_NOT_DIR, &netfid, &oplock, buf,
274 275
			 cifs_sb->local_nls, cifs_sb->mnt_cifs_flags
				 & CIFS_MOUNT_MAP_SPECIAL_CHR);
276 277 278
	else
		rc = -EIO; /* no NT SMB support fall into legacy open below */

279 280 281 282 283 284 285
	if (rc == -EIO) {
		/* Old server, try legacy style OpenX */
		rc = SMBLegacyOpen(xid, pTcon, full_path, disposition,
			desiredAccess, CREATE_NOT_DIR, &netfid, &oplock, buf,
			cifs_sb->local_nls, cifs_sb->mnt_cifs_flags
				& CIFS_MOUNT_MAP_SPECIAL_CHR);
	}
L
Linus Torvalds 已提交
286
	if (rc) {
287
		cFYI(1, ("cifs_open returned 0x%x", rc));
L
Linus Torvalds 已提交
288 289 290 291 292 293 294 295 296 297 298 299
		goto out;
	}
	file->private_data =
		kmalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
	if (file->private_data == NULL) {
		rc = -ENOMEM;
		goto out;
	}
	pCifsFile = cifs_init_private(file->private_data, inode, file, netfid);
	write_lock(&GlobalSMBSeslock);
	list_add(&pCifsFile->tlist, &pTcon->openFileList);

300
	pCifsInode = CIFS_I(file->f_path.dentry->d_inode);
L
Linus Torvalds 已提交
301 302 303 304 305 306 307 308
	if (pCifsInode) {
		rc = cifs_open_inode_helper(inode, file, pCifsInode,
					    pCifsFile, pTcon,
					    &oplock, buf, full_path, xid);
	} else {
		write_unlock(&GlobalSMBSeslock);
	}

S
Steve French 已提交
309
	if (oplock & CIFS_CREATE_ACTION) {
L
Linus Torvalds 已提交
310 311
		/* time to set mode which we can not set earlier due to
		   problems creating new read-only files */
312
		if (pTcon->unix_ext) {
313 314 315 316 317 318 319 320 321 322
			struct cifs_unix_set_info_args args = {
				.mode	= inode->i_mode,
				.uid	= NO_CHANGE_64,
				.gid	= NO_CHANGE_64,
				.ctime	= NO_CHANGE_64,
				.atime	= NO_CHANGE_64,
				.mtime	= NO_CHANGE_64,
				.device	= 0,
			};
			CIFSSMBUnixSetInfo(xid, pTcon, full_path, &args,
323
					    cifs_sb->local_nls,
S
Steve French 已提交
324
					    cifs_sb->mnt_cifs_flags &
325
						CIFS_MOUNT_MAP_SPECIAL_CHR);
L
Linus Torvalds 已提交
326 327 328 329 330 331 332 333 334 335
		}
	}

out:
	kfree(buf);
	kfree(full_path);
	FreeXid(xid);
	return rc;
}

A
Adrian Bunk 已提交
336
/* Try to reacquire byte range locks that were released when session */
L
Linus Torvalds 已提交
337 338 339 340 341 342 343 344 345 346
/* to server was lost */
static int cifs_relock_file(struct cifsFileInfo *cifsFile)
{
	int rc = 0;

/* BB list all locks open on this file and relock */

	return rc;
}

347
static int cifs_reopen_file(struct file *file, bool can_flush)
L
Linus Torvalds 已提交
348 349 350 351 352 353 354
{
	int rc = -EACCES;
	int xid, oplock;
	struct cifs_sb_info *cifs_sb;
	struct cifsTconInfo *pTcon;
	struct cifsFileInfo *pCifsFile;
	struct cifsInodeInfo *pCifsInode;
S
Steve French 已提交
355
	struct inode *inode;
L
Linus Torvalds 已提交
356 357 358 359 360
	char *full_path = NULL;
	int desiredAccess;
	int disposition = FILE_OPEN;
	__u16 netfid;

S
Steve French 已提交
361
	if (file->private_data)
L
Linus Torvalds 已提交
362
		pCifsFile = (struct cifsFileInfo *)file->private_data;
S
Steve French 已提交
363
	else
L
Linus Torvalds 已提交
364 365 366 367
		return -EBADF;

	xid = GetXid();
	down(&pCifsFile->fh_sem);
368
	if (!pCifsFile->invalidHandle) {
L
Linus Torvalds 已提交
369 370 371 372 373
		up(&pCifsFile->fh_sem);
		FreeXid(xid);
		return 0;
	}

374
	if (file->f_path.dentry == NULL) {
375 376 377 378 379 380 381
		cERROR(1, ("no valid name if dentry freed"));
		dump_stack();
		rc = -EBADF;
		goto reopen_error_exit;
	}

	inode = file->f_path.dentry->d_inode;
S
Steve French 已提交
382
	if (inode == NULL) {
383 384 385 386
		cERROR(1, ("inode not valid"));
		dump_stack();
		rc = -EBADF;
		goto reopen_error_exit;
L
Linus Torvalds 已提交
387
	}
388

L
Linus Torvalds 已提交
389 390
	cifs_sb = CIFS_SB(inode->i_sb);
	pTcon = cifs_sb->tcon;
391

L
Linus Torvalds 已提交
392 393 394 395
/* can not grab rename sem here because various ops, including
   those that already have the rename sem can end up causing writepage
   to get called and if the server was down that means we end up here,
   and we can never tell if the caller already has the rename_sem */
396
	full_path = build_path_from_dentry(file->f_path.dentry);
L
Linus Torvalds 已提交
397
	if (full_path == NULL) {
398 399
		rc = -ENOMEM;
reopen_error_exit:
L
Linus Torvalds 已提交
400 401
		up(&pCifsFile->fh_sem);
		FreeXid(xid);
402
		return rc;
L
Linus Torvalds 已提交
403 404
	}

405
	cFYI(1, ("inode = 0x%p file flags 0x%x for %s",
S
Steve French 已提交
406
		 inode, file->f_flags, full_path));
L
Linus Torvalds 已提交
407 408 409 410 411
	desiredAccess = cifs_convert_flags(file->f_flags);

	if (oplockEnabled)
		oplock = REQ_OPLOCK;
	else
412
		oplock = 0;
L
Linus Torvalds 已提交
413 414

	/* Can not refresh inode by passing in file_info buf to be returned
S
Steve French 已提交
415 416
	   by SMBOpen and then calling get_inode_info with returned buf
	   since file might have write behind data that needs to be flushed
L
Linus Torvalds 已提交
417 418 419 420 421
	   and server version of file size can be stale. If we knew for sure
	   that inode was not dirty locally we could do this */

	rc = CIFSSMBOpen(xid, pTcon, full_path, disposition, desiredAccess,
			 CREATE_NOT_DIR, &netfid, &oplock, NULL,
S
Steve French 已提交
422
			 cifs_sb->local_nls, cifs_sb->mnt_cifs_flags &
423
				CIFS_MOUNT_MAP_SPECIAL_CHR);
L
Linus Torvalds 已提交
424 425
	if (rc) {
		up(&pCifsFile->fh_sem);
426 427
		cFYI(1, ("cifs_open returned 0x%x", rc));
		cFYI(1, ("oplock: %d", oplock));
L
Linus Torvalds 已提交
428 429
	} else {
		pCifsFile->netfid = netfid;
430
		pCifsFile->invalidHandle = false;
L
Linus Torvalds 已提交
431 432 433 434
		up(&pCifsFile->fh_sem);
		pCifsInode = CIFS_I(inode);
		if (pCifsInode) {
			if (can_flush) {
435 436 437
				rc = filemap_write_and_wait(inode->i_mapping);
				if (rc != 0)
					CIFS_I(inode)->write_behind_rc = rc;
L
Linus Torvalds 已提交
438 439
			/* temporarily disable caching while we
			   go to server to get inode info */
440 441
				pCifsInode->clientCanCacheAll = false;
				pCifsInode->clientCanCacheRead = false;
442
				if (pTcon->unix_ext)
L
Linus Torvalds 已提交
443 444 445 446 447
					rc = cifs_get_inode_info_unix(&inode,
						full_path, inode->i_sb, xid);
				else
					rc = cifs_get_inode_info(&inode,
						full_path, NULL, inode->i_sb,
448
						xid, NULL);
L
Linus Torvalds 已提交
449 450 451 452 453 454 455
			} /* else we are writing out data to server already
			     and could deadlock if we tried to flush data, and
			     since we do not know if we have data that would
			     invalidate the current end of file on the server
			     we can not go to the server to get the new inod
			     info */
			if ((oplock & 0xF) == OPLOCK_EXCLUSIVE) {
456 457
				pCifsInode->clientCanCacheAll = true;
				pCifsInode->clientCanCacheRead = true;
L
Linus Torvalds 已提交
458
				cFYI(1, ("Exclusive Oplock granted on inode %p",
459
					 file->f_path.dentry->d_inode));
L
Linus Torvalds 已提交
460
			} else if ((oplock & 0xF) == OPLOCK_READ) {
461 462
				pCifsInode->clientCanCacheRead = true;
				pCifsInode->clientCanCacheAll = false;
L
Linus Torvalds 已提交
463
			} else {
464 465
				pCifsInode->clientCanCacheRead = false;
				pCifsInode->clientCanCacheAll = false;
L
Linus Torvalds 已提交
466 467 468 469 470 471 472 473 474 475 476 477 478
			}
			cifs_relock_file(pCifsFile);
		}
	}

	kfree(full_path);
	FreeXid(xid);
	return rc;
}

int cifs_close(struct inode *inode, struct file *file)
{
	int rc = 0;
479
	int xid, timeout;
L
Linus Torvalds 已提交
480 481 482 483 484 485 486 487 488 489
	struct cifs_sb_info *cifs_sb;
	struct cifsTconInfo *pTcon;
	struct cifsFileInfo *pSMBFile =
		(struct cifsFileInfo *)file->private_data;

	xid = GetXid();

	cifs_sb = CIFS_SB(inode->i_sb);
	pTcon = cifs_sb->tcon;
	if (pSMBFile) {
J
[CIFS]  
Jeremy Allison 已提交
490
		struct cifsLockInfo *li, *tmp;
491
		write_lock(&GlobalSMBSeslock);
492
		pSMBFile->closePend = true;
L
Linus Torvalds 已提交
493 494 495
		if (pTcon) {
			/* no sense reconnecting to close a file that is
			   already closed */
S
Steve French 已提交
496
			if (!pTcon->need_reconnect) {
497
				write_unlock(&GlobalSMBSeslock);
498
				timeout = 2;
S
Steve French 已提交
499
				while ((atomic_read(&pSMBFile->wrtPending) != 0)
500
					&& (timeout <= 2048)) {
501 502 503 504 505
					/* Give write a better chance to get to
					server ahead of the close.  We do not
					want to add a wait_q here as it would
					increase the memory utilization as
					the struct would be in each open file,
S
Steve French 已提交
506
					but this should give enough time to
507
					clear the socket */
508 509
					cFYI(DBG2,
						("close delay, write pending"));
510 511
					msleep(timeout);
					timeout *= 4;
512
				}
S
Steve French 已提交
513
				if (atomic_read(&pSMBFile->wrtPending))
514 515 516 517
					cERROR(1, ("close with pending write"));
				if (!pTcon->need_reconnect &&
				    !pSMBFile->invalidHandle)
					rc = CIFSSMBClose(xid, pTcon,
L
Linus Torvalds 已提交
518
						  pSMBFile->netfid);
519 520 521 522
			} else
				write_unlock(&GlobalSMBSeslock);
		} else
			write_unlock(&GlobalSMBSeslock);
J
[CIFS]  
Jeremy Allison 已提交
523 524 525

		/* Delete any outstanding lock records.
		   We'll lose them when the file is closed anyway. */
526
		mutex_lock(&pSMBFile->lock_mutex);
J
[CIFS]  
Jeremy Allison 已提交
527 528 529 530
		list_for_each_entry_safe(li, tmp, &pSMBFile->llist, llist) {
			list_del(&li->llist);
			kfree(li);
		}
531
		mutex_unlock(&pSMBFile->lock_mutex);
J
[CIFS]  
Jeremy Allison 已提交
532

533
		write_lock(&GlobalSMBSeslock);
L
Linus Torvalds 已提交
534 535
		list_del(&pSMBFile->flist);
		list_del(&pSMBFile->tlist);
536
		write_unlock(&GlobalSMBSeslock);
537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553
		timeout = 10;
		/* We waited above to give the SMBWrite a chance to issue
		   on the wire (so we do not get SMBWrite returning EBADF
		   if writepages is racing with close.  Note that writepages
		   does not specify a file handle, so it is possible for a file
		   to be opened twice, and the application close the "wrong"
		   file handle - in these cases we delay long enough to allow
		   the SMBWrite to get on the wire before the SMB Close.
		   We allow total wait here over 45 seconds, more than
		   oplock break time, and more than enough to allow any write
		   to complete on the server, or to time out on the client */
		while ((atomic_read(&pSMBFile->wrtPending) != 0)
				&& (timeout <= 50000)) {
			cERROR(1, ("writes pending, delay free of handle"));
			msleep(timeout);
			timeout *= 8;
		}
L
Linus Torvalds 已提交
554 555 556 557 558
		kfree(file->private_data);
		file->private_data = NULL;
	} else
		rc = -EBADF;

559
	read_lock(&GlobalSMBSeslock);
L
Linus Torvalds 已提交
560 561 562 563
	if (list_empty(&(CIFS_I(inode)->openFileList))) {
		cFYI(1, ("closing last open instance for inode %p", inode));
		/* if the file is not open we do not know if we can cache info
		   on this inode, much less write behind and read ahead */
564 565
		CIFS_I(inode)->clientCanCacheRead = false;
		CIFS_I(inode)->clientCanCacheAll  = false;
L
Linus Torvalds 已提交
566
	}
567
	read_unlock(&GlobalSMBSeslock);
S
Steve French 已提交
568
	if ((rc == 0) && CIFS_I(inode)->write_behind_rc)
L
Linus Torvalds 已提交
569 570 571 572 573 574 575 576 577 578 579 580 581
		rc = CIFS_I(inode)->write_behind_rc;
	FreeXid(xid);
	return rc;
}

int cifs_closedir(struct inode *inode, struct file *file)
{
	int rc = 0;
	int xid;
	struct cifsFileInfo *pCFileStruct =
	    (struct cifsFileInfo *)file->private_data;
	char *ptmp;

582
	cFYI(1, ("Closedir inode = 0x%p", inode));
L
Linus Torvalds 已提交
583 584 585 586 587

	xid = GetXid();

	if (pCFileStruct) {
		struct cifsTconInfo *pTcon;
S
Steve French 已提交
588 589
		struct cifs_sb_info *cifs_sb =
			CIFS_SB(file->f_path.dentry->d_sb);
L
Linus Torvalds 已提交
590 591 592 593

		pTcon = cifs_sb->tcon;

		cFYI(1, ("Freeing private data in close dir"));
594
		write_lock(&GlobalSMBSeslock);
595 596 597
		if (!pCFileStruct->srch_inf.endOfSearch &&
		    !pCFileStruct->invalidHandle) {
			pCFileStruct->invalidHandle = true;
598
			write_unlock(&GlobalSMBSeslock);
L
Linus Torvalds 已提交
599 600 601 602 603
			rc = CIFSFindClose(xid, pTcon, pCFileStruct->netfid);
			cFYI(1, ("Closing uncompleted readdir with rc %d",
				 rc));
			/* not much we can do if it fails anyway, ignore rc */
			rc = 0;
604 605
		} else
			write_unlock(&GlobalSMBSeslock);
L
Linus Torvalds 已提交
606 607
		ptmp = pCFileStruct->srch_inf.ntwrk_buf_start;
		if (ptmp) {
608
			cFYI(1, ("closedir free smb buf in srch struct"));
L
Linus Torvalds 已提交
609
			pCFileStruct->srch_inf.ntwrk_buf_start = NULL;
S
Steve French 已提交
610
			if (pCFileStruct->srch_inf.smallBuf)
611 612 613
				cifs_small_buf_release(ptmp);
			else
				cifs_buf_release(ptmp);
L
Linus Torvalds 已提交
614 615 616 617 618 619 620 621 622
		}
		kfree(file->private_data);
		file->private_data = NULL;
	}
	/* BB can we lock the filestruct while this is going on? */
	FreeXid(xid);
	return rc;
}

J
[CIFS]  
Jeremy Allison 已提交
623 624 625
static int store_file_lock(struct cifsFileInfo *fid, __u64 len,
				__u64 offset, __u8 lockType)
{
S
Steve French 已提交
626 627
	struct cifsLockInfo *li =
		kmalloc(sizeof(struct cifsLockInfo), GFP_KERNEL);
J
[CIFS]  
Jeremy Allison 已提交
628 629 630 631 632
	if (li == NULL)
		return -ENOMEM;
	li->offset = offset;
	li->length = len;
	li->type = lockType;
633
	mutex_lock(&fid->lock_mutex);
J
[CIFS]  
Jeremy Allison 已提交
634
	list_add(&li->llist, &fid->llist);
635
	mutex_unlock(&fid->lock_mutex);
J
[CIFS]  
Jeremy Allison 已提交
636 637 638
	return 0;
}

L
Linus Torvalds 已提交
639 640 641 642 643 644
int cifs_lock(struct file *file, int cmd, struct file_lock *pfLock)
{
	int rc, xid;
	__u32 numLock = 0;
	__u32 numUnlock = 0;
	__u64 length;
645
	bool wait_flag = false;
L
Linus Torvalds 已提交
646 647
	struct cifs_sb_info *cifs_sb;
	struct cifsTconInfo *pTcon;
648 649
	__u16 netfid;
	__u8 lockType = LOCKING_ANDX_LARGE_FILES;
650
	bool posix_locking;
L
Linus Torvalds 已提交
651 652 653 654 655 656 657

	length = 1 + pfLock->fl_end - pfLock->fl_start;
	rc = -EACCES;
	xid = GetXid();

	cFYI(1, ("Lock parm: 0x%x flockflags: "
		 "0x%x flocktype: 0x%x start: %lld end: %lld",
S
Steve French 已提交
658 659
		cmd, pfLock->fl_flags, pfLock->fl_type, pfLock->fl_start,
		pfLock->fl_end));
L
Linus Torvalds 已提交
660 661

	if (pfLock->fl_flags & FL_POSIX)
662
		cFYI(1, ("Posix"));
L
Linus Torvalds 已提交
663
	if (pfLock->fl_flags & FL_FLOCK)
664
		cFYI(1, ("Flock"));
L
Linus Torvalds 已提交
665
	if (pfLock->fl_flags & FL_SLEEP) {
666
		cFYI(1, ("Blocking lock"));
667
		wait_flag = true;
L
Linus Torvalds 已提交
668 669 670
	}
	if (pfLock->fl_flags & FL_ACCESS)
		cFYI(1, ("Process suspended by mandatory locking - "
671
			 "not implemented yet"));
L
Linus Torvalds 已提交
672 673
	if (pfLock->fl_flags & FL_LEASE)
		cFYI(1, ("Lease on file - not implemented yet"));
S
Steve French 已提交
674
	if (pfLock->fl_flags &
L
Linus Torvalds 已提交
675 676 677 678 679 680 681
	    (~(FL_POSIX | FL_FLOCK | FL_SLEEP | FL_ACCESS | FL_LEASE)))
		cFYI(1, ("Unknown lock flags 0x%x", pfLock->fl_flags));

	if (pfLock->fl_type == F_WRLCK) {
		cFYI(1, ("F_WRLCK "));
		numLock = 1;
	} else if (pfLock->fl_type == F_UNLCK) {
682
		cFYI(1, ("F_UNLCK"));
L
Linus Torvalds 已提交
683
		numUnlock = 1;
684 685
		/* Check if unlock includes more than
		one lock range */
L
Linus Torvalds 已提交
686
	} else if (pfLock->fl_type == F_RDLCK) {
687
		cFYI(1, ("F_RDLCK"));
L
Linus Torvalds 已提交
688 689 690
		lockType |= LOCKING_ANDX_SHARED_LOCK;
		numLock = 1;
	} else if (pfLock->fl_type == F_EXLCK) {
691
		cFYI(1, ("F_EXLCK"));
L
Linus Torvalds 已提交
692 693
		numLock = 1;
	} else if (pfLock->fl_type == F_SHLCK) {
694
		cFYI(1, ("F_SHLCK"));
L
Linus Torvalds 已提交
695 696 697
		lockType |= LOCKING_ANDX_SHARED_LOCK;
		numLock = 1;
	} else
698
		cFYI(1, ("Unknown type of lock"));
L
Linus Torvalds 已提交
699

700
	cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
L
Linus Torvalds 已提交
701 702 703 704 705 706
	pTcon = cifs_sb->tcon;

	if (file->private_data == NULL) {
		FreeXid(xid);
		return -EBADF;
	}
707 708
	netfid = ((struct cifsFileInfo *)file->private_data)->netfid;

J
[CIFS]  
Jeremy Allison 已提交
709 710
	posix_locking = (cifs_sb->tcon->ses->capabilities & CAP_UNIX) &&
			(CIFS_UNIX_FCNTL_CAP & le64_to_cpu(cifs_sb->tcon->fsUnixInfo.Capability));
L
Linus Torvalds 已提交
711

712 713 714
	/* BB add code here to normalize offset and length to
	account for negative length which we can not accept over the
	wire */
L
Linus Torvalds 已提交
715
	if (IS_GETLK(cmd)) {
S
Steve French 已提交
716
		if (posix_locking) {
717
			int posix_lock_type;
S
Steve French 已提交
718
			if (lockType & LOCKING_ANDX_SHARED_LOCK)
719 720 721 722
				posix_lock_type = CIFS_RDLCK;
			else
				posix_lock_type = CIFS_WRLCK;
			rc = CIFSSMBPosixLock(xid, pTcon, netfid, 1 /* get */,
723
					length,	pfLock,
724 725 726 727 728 729 730 731
					posix_lock_type, wait_flag);
			FreeXid(xid);
			return rc;
		}

		/* BB we could chain these into one lock request BB */
		rc = CIFSSMBLock(xid, pTcon, netfid, length, pfLock->fl_start,
				 0, 1, lockType, 0 /* wait flag */ );
L
Linus Torvalds 已提交
732
		if (rc == 0) {
S
Steve French 已提交
733
			rc = CIFSSMBLock(xid, pTcon, netfid, length,
L
Linus Torvalds 已提交
734 735 736 737 738 739
					 pfLock->fl_start, 1 /* numUnlock */ ,
					 0 /* numLock */ , lockType,
					 0 /* wait flag */ );
			pfLock->fl_type = F_UNLCK;
			if (rc != 0)
				cERROR(1, ("Error unlocking previously locked "
740
					   "range %d during test of lock", rc));
L
Linus Torvalds 已提交
741 742 743 744 745 746 747 748 749 750 751
			rc = 0;

		} else {
			/* if rc == ERR_SHARING_VIOLATION ? */
			rc = 0;	/* do not change lock type to unlock
				   since range in use */
		}

		FreeXid(xid);
		return rc;
	}
J
[CIFS]  
Jeremy Allison 已提交
752 753 754 755 756 757 758 759 760

	if (!numLock && !numUnlock) {
		/* if no lock or unlock then nothing
		to do since we do not know what it is */
		FreeXid(xid);
		return -EOPNOTSUPP;
	}

	if (posix_locking) {
761
		int posix_lock_type;
S
Steve French 已提交
762
		if (lockType & LOCKING_ANDX_SHARED_LOCK)
763 764 765
			posix_lock_type = CIFS_RDLCK;
		else
			posix_lock_type = CIFS_WRLCK;
766

S
Steve French 已提交
767
		if (numUnlock == 1)
768
			posix_lock_type = CIFS_UNLCK;
J
[CIFS]  
Jeremy Allison 已提交
769

770
		rc = CIFSSMBPosixLock(xid, pTcon, netfid, 0 /* set */,
771
				      length, pfLock,
772
				      posix_lock_type, wait_flag);
J
[CIFS]  
Jeremy Allison 已提交
773
	} else {
S
Steve French 已提交
774 775
		struct cifsFileInfo *fid =
			(struct cifsFileInfo *)file->private_data;
J
[CIFS]  
Jeremy Allison 已提交
776 777

		if (numLock) {
S
Steve French 已提交
778 779
			rc = CIFSSMBLock(xid, pTcon, netfid, length,
					pfLock->fl_start,
J
[CIFS]  
Jeremy Allison 已提交
780 781 782 783 784 785 786 787 788 789 790 791 792
					0, numLock, lockType, wait_flag);

			if (rc == 0) {
				/* For Windows locks we must store them. */
				rc = store_file_lock(fid, length,
						pfLock->fl_start, lockType);
			}
		} else if (numUnlock) {
			/* For each stored lock that this unlock overlaps
			   completely, unlock it. */
			int stored_rc = 0;
			struct cifsLockInfo *li, *tmp;

793
			rc = 0;
794
			mutex_lock(&fid->lock_mutex);
J
[CIFS]  
Jeremy Allison 已提交
795 796
			list_for_each_entry_safe(li, tmp, &fid->llist, llist) {
				if (pfLock->fl_start <= li->offset &&
S
Steve French 已提交
797
						(pfLock->fl_start + length) >=
798
						(li->offset + li->length)) {
S
Steve French 已提交
799 800
					stored_rc = CIFSSMBLock(xid, pTcon,
							netfid,
J
[CIFS]  
Jeremy Allison 已提交
801
							li->length, li->offset,
802
							1, 0, li->type, false);
J
[CIFS]  
Jeremy Allison 已提交
803 804 805 806 807 808 809
					if (stored_rc)
						rc = stored_rc;

					list_del(&li->llist);
					kfree(li);
				}
			}
810
			mutex_unlock(&fid->lock_mutex);
J
[CIFS]  
Jeremy Allison 已提交
811 812 813
		}
	}

814
	if (pfLock->fl_flags & FL_POSIX)
L
Linus Torvalds 已提交
815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830
		posix_lock_file_wait(file, pfLock);
	FreeXid(xid);
	return rc;
}

ssize_t cifs_user_write(struct file *file, const char __user *write_data,
	size_t write_size, loff_t *poffset)
{
	int rc = 0;
	unsigned int bytes_written = 0;
	unsigned int total_written;
	struct cifs_sb_info *cifs_sb;
	struct cifsTconInfo *pTcon;
	int xid, long_op;
	struct cifsFileInfo *open_file;

831
	cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
L
Linus Torvalds 已提交
832 833 834 835 836

	pTcon = cifs_sb->tcon;

	/* cFYI(1,
	   (" write %d bytes to offset %lld of %s", write_size,
837
	   *poffset, file->f_path.dentry->d_name.name)); */
L
Linus Torvalds 已提交
838 839 840

	if (file->private_data == NULL)
		return -EBADF;
841
	open_file = (struct cifsFileInfo *) file->private_data;
842

843 844 845 846
	rc = generic_write_checks(file, poffset, &write_size, 0);
	if (rc)
		return rc;

L
Linus Torvalds 已提交
847 848
	xid = GetXid();

849
	if (*poffset > file->f_path.dentry->d_inode->i_size)
850
		long_op = CIFS_VLONG_OP; /* writes past EOF take long time */
L
Linus Torvalds 已提交
851
	else
852
		long_op = CIFS_LONG_OP;
L
Linus Torvalds 已提交
853 854 855 856 857 858 859 860 861 862 863 864

	for (total_written = 0; write_size > total_written;
	     total_written += bytes_written) {
		rc = -EAGAIN;
		while (rc == -EAGAIN) {
			if (file->private_data == NULL) {
				/* file has been closed on us */
				FreeXid(xid);
			/* if we have gotten here we have written some data
			   and blocked, and the file has been freed on us while
			   we blocked so return what we managed to write */
				return total_written;
S
Steve French 已提交
865
			}
L
Linus Torvalds 已提交
866 867 868 869 870 871 872 873 874 875 876 877
			if (open_file->closePend) {
				FreeXid(xid);
				if (total_written)
					return total_written;
				else
					return -EBADF;
			}
			if (open_file->invalidHandle) {
				/* we could deadlock if we called
				   filemap_fdatawait from here so tell
				   reopen_file not to flush data to server
				   now */
878
				rc = cifs_reopen_file(file, false);
L
Linus Torvalds 已提交
879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898
				if (rc != 0)
					break;
			}

			rc = CIFSSMBWrite(xid, pTcon,
				open_file->netfid,
				min_t(const int, cifs_sb->wsize,
				      write_size - total_written),
				*poffset, &bytes_written,
				NULL, write_data + total_written, long_op);
		}
		if (rc || (bytes_written == 0)) {
			if (total_written)
				break;
			else {
				FreeXid(xid);
				return rc;
			}
		} else
			*poffset += bytes_written;
899
		long_op = CIFS_STD_OP; /* subsequent writes fast -
L
Linus Torvalds 已提交
900 901 902
				    15 seconds is plenty */
	}

903
	cifs_stats_bytes_written(pTcon, total_written);
L
Linus Torvalds 已提交
904 905

	/* since the write may have blocked check these pointers again */
906 907
	if ((file->f_path.dentry) && (file->f_path.dentry->d_inode)) {
		struct inode *inode = file->f_path.dentry->d_inode;
S
Steve French 已提交
908 909
/* Do not update local mtime - server will set its actual value on write
 *		inode->i_ctime = inode->i_mtime =
910 911 912 913 914
 * 			current_fs_time(inode->i_sb);*/
		if (total_written > 0) {
			spin_lock(&inode->i_lock);
			if (*poffset > file->f_path.dentry->d_inode->i_size)
				i_size_write(file->f_path.dentry->d_inode,
L
Linus Torvalds 已提交
915
					*poffset);
916
			spin_unlock(&inode->i_lock);
L
Linus Torvalds 已提交
917
		}
S
Steve French 已提交
918
		mark_inode_dirty_sync(file->f_path.dentry->d_inode);
L
Linus Torvalds 已提交
919 920 921 922 923 924
	}
	FreeXid(xid);
	return total_written;
}

static ssize_t cifs_write(struct file *file, const char *write_data,
N
Nick Piggin 已提交
925
			  size_t write_size, loff_t *poffset)
L
Linus Torvalds 已提交
926 927 928 929 930 931 932 933 934
{
	int rc = 0;
	unsigned int bytes_written = 0;
	unsigned int total_written;
	struct cifs_sb_info *cifs_sb;
	struct cifsTconInfo *pTcon;
	int xid, long_op;
	struct cifsFileInfo *open_file;

935
	cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
L
Linus Torvalds 已提交
936 937 938

	pTcon = cifs_sb->tcon;

S
Steve French 已提交
939
	cFYI(1, ("write %zd bytes to offset %lld of %s", write_size,
940
	   *poffset, file->f_path.dentry->d_name.name));
L
Linus Torvalds 已提交
941 942 943

	if (file->private_data == NULL)
		return -EBADF;
944
	open_file = (struct cifsFileInfo *)file->private_data;
945

L
Linus Torvalds 已提交
946 947
	xid = GetXid();

948
	if (*poffset > file->f_path.dentry->d_inode->i_size)
949
		long_op = CIFS_VLONG_OP; /* writes past EOF can be slow */
L
Linus Torvalds 已提交
950
	else
951
		long_op = CIFS_LONG_OP;
L
Linus Torvalds 已提交
952 953 954 955 956 957 958 959 960 961

	for (total_written = 0; write_size > total_written;
	     total_written += bytes_written) {
		rc = -EAGAIN;
		while (rc == -EAGAIN) {
			if (file->private_data == NULL) {
				/* file has been closed on us */
				FreeXid(xid);
			/* if we have gotten here we have written some data
			   and blocked, and the file has been freed on us
S
Steve French 已提交
962
			   while we blocked so return what we managed to
L
Linus Torvalds 已提交
963 964
			   write */
				return total_written;
S
Steve French 已提交
965
			}
L
Linus Torvalds 已提交
966 967 968 969 970 971 972 973 974 975
			if (open_file->closePend) {
				FreeXid(xid);
				if (total_written)
					return total_written;
				else
					return -EBADF;
			}
			if (open_file->invalidHandle) {
				/* we could deadlock if we called
				   filemap_fdatawait from here so tell
S
Steve French 已提交
976
				   reopen_file not to flush data to
L
Linus Torvalds 已提交
977
				   server now */
978
				rc = cifs_reopen_file(file, false);
L
Linus Torvalds 已提交
979 980 981
				if (rc != 0)
					break;
			}
S
Steve French 已提交
982 983
			if (experimEnabled || (pTcon->ses->server &&
				((pTcon->ses->server->secMode &
S
Steve French 已提交
984
				(SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED))
S
Steve French 已提交
985
				== 0))) {
986 987 988
				struct kvec iov[2];
				unsigned int len;

989
				len = min((size_t)cifs_sb->wsize,
990 991 992 993 994
					  write_size - total_written);
				/* iov[0] is reserved for smb header */
				iov[1].iov_base = (char *)write_data +
						  total_written;
				iov[1].iov_len = len;
995
				rc = CIFSSMBWrite2(xid, pTcon,
996
						open_file->netfid, len,
997
						*poffset, &bytes_written,
998
						iov, 1, long_op);
999
			} else
1000 1001 1002 1003 1004 1005 1006
				rc = CIFSSMBWrite(xid, pTcon,
					 open_file->netfid,
					 min_t(const int, cifs_sb->wsize,
					       write_size - total_written),
					 *poffset, &bytes_written,
					 write_data + total_written,
					 NULL, long_op);
L
Linus Torvalds 已提交
1007 1008 1009 1010 1011 1012 1013 1014 1015 1016
		}
		if (rc || (bytes_written == 0)) {
			if (total_written)
				break;
			else {
				FreeXid(xid);
				return rc;
			}
		} else
			*poffset += bytes_written;
1017
		long_op = CIFS_STD_OP; /* subsequent writes fast -
L
Linus Torvalds 已提交
1018 1019 1020
				    15 seconds is plenty */
	}

1021
	cifs_stats_bytes_written(pTcon, total_written);
L
Linus Torvalds 已提交
1022 1023

	/* since the write may have blocked check these pointers again */
1024
	if ((file->f_path.dentry) && (file->f_path.dentry->d_inode)) {
1025
/*BB We could make this contingent on superblock ATIME flag too */
1026 1027 1028 1029 1030 1031 1032 1033
/*		file->f_path.dentry->d_inode->i_ctime =
		file->f_path.dentry->d_inode->i_mtime = CURRENT_TIME;*/
		if (total_written > 0) {
			spin_lock(&file->f_path.dentry->d_inode->i_lock);
			if (*poffset > file->f_path.dentry->d_inode->i_size)
				i_size_write(file->f_path.dentry->d_inode,
					     *poffset);
			spin_unlock(&file->f_path.dentry->d_inode->i_lock);
L
Linus Torvalds 已提交
1034
		}
1035
		mark_inode_dirty_sync(file->f_path.dentry->d_inode);
L
Linus Torvalds 已提交
1036 1037 1038 1039 1040
	}
	FreeXid(xid);
	return total_written;
}

S
Steve French 已提交
1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071
#ifdef CONFIG_CIFS_EXPERIMENTAL
struct cifsFileInfo *find_readable_file(struct cifsInodeInfo *cifs_inode)
{
	struct cifsFileInfo *open_file = NULL;

	read_lock(&GlobalSMBSeslock);
	/* we could simply get the first_list_entry since write-only entries
	   are always at the end of the list but since the first entry might
	   have a close pending, we go through the whole list */
	list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
		if (open_file->closePend)
			continue;
		if (open_file->pfile && ((open_file->pfile->f_flags & O_RDWR) ||
		    (open_file->pfile->f_flags & O_RDONLY))) {
			if (!open_file->invalidHandle) {
				/* found a good file */
				/* lock it so it will not be closed on us */
				atomic_inc(&open_file->wrtPending);
				read_unlock(&GlobalSMBSeslock);
				return open_file;
			} /* else might as well continue, and look for
			     another, or simply have the caller reopen it
			     again rather than trying to fix this handle */
		} else /* write only file */
			break; /* write only files are last so must be done */
	}
	read_unlock(&GlobalSMBSeslock);
	return NULL;
}
#endif

1072
struct cifsFileInfo *find_writable_file(struct cifsInodeInfo *cifs_inode)
1073 1074
{
	struct cifsFileInfo *open_file;
1075
	bool any_available = false;
1076
	int rc;
1077

1078 1079 1080 1081
	/* Having a null inode here (because mapping->host was set to zero by
	the VFS or MM) should not happen but we had reports of on oops (due to
	it being zero) during stress testcases so we need to check for it */

S
Steve French 已提交
1082 1083
	if (cifs_inode == NULL) {
		cERROR(1, ("Null inode passed to cifs_writeable_file"));
1084 1085 1086 1087
		dump_stack();
		return NULL;
	}

1088
	read_lock(&GlobalSMBSeslock);
1089
refind_writable:
1090
	list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
1091 1092
		if (open_file->closePend ||
		    (!any_available && open_file->pid != current->tgid))
1093
			continue;
1094

1095 1096 1097
		if (open_file->pfile &&
		    ((open_file->pfile->f_flags & O_RDWR) ||
		     (open_file->pfile->f_flags & O_WRONLY))) {
1098
			atomic_inc(&open_file->wrtPending);
1099 1100 1101 1102 1103 1104

			if (!open_file->invalidHandle) {
				/* found a good writable file */
				read_unlock(&GlobalSMBSeslock);
				return open_file;
			}
S
Steve French 已提交
1105

1106
			read_unlock(&GlobalSMBSeslock);
1107
			/* Had to unlock since following call can block */
1108
			rc = cifs_reopen_file(open_file->pfile, false);
S
Steve French 已提交
1109
			if (!rc) {
1110 1111 1112 1113
				if (!open_file->closePend)
					return open_file;
				else { /* start over in case this was deleted */
				       /* since the list could be modified */
1114
					read_lock(&GlobalSMBSeslock);
1115
					atomic_dec(&open_file->wrtPending);
1116
					goto refind_writable;
1117 1118
				}
			}
1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131

			/* if it fails, try another handle if possible -
			(we can not do this if closePending since
			loop could be modified - in which case we
			have to start at the beginning of the list
			again. Note that it would be bad
			to hold up writepages here (rather than
			in caller) with continuous retries */
			cFYI(1, ("wp failed on reopen file"));
			read_lock(&GlobalSMBSeslock);
			/* can not use this handle, no write
			   pending on this one after all */
			atomic_dec(&open_file->wrtPending);
S
Steve French 已提交
1132

1133 1134 1135 1136 1137 1138 1139 1140 1141
			if (open_file->closePend) /* list could have changed */
				goto refind_writable;
			/* else we simply continue to the next entry. Thus
			   we do not loop on reopen errors.  If we
			   can not reopen the file, for example if we
			   reconnected to a server with another client
			   racing to delete or lock the file we would not
			   make progress if we restarted before the beginning
			   of the loop here. */
1142 1143
		}
	}
1144 1145 1146 1147 1148
	/* couldn't find useable FH with same pid, try any available */
	if (!any_available) {
		any_available = true;
		goto refind_writable;
	}
1149 1150 1151 1152
	read_unlock(&GlobalSMBSeslock);
	return NULL;
}

L
Linus Torvalds 已提交
1153 1154 1155 1156 1157 1158 1159 1160 1161 1162
static int cifs_partialpagewrite(struct page *page, unsigned from, unsigned to)
{
	struct address_space *mapping = page->mapping;
	loff_t offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
	char *write_data;
	int rc = -EFAULT;
	int bytes_written = 0;
	struct cifs_sb_info *cifs_sb;
	struct cifsTconInfo *pTcon;
	struct inode *inode;
1163
	struct cifsFileInfo *open_file;
L
Linus Torvalds 已提交
1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188

	if (!mapping || !mapping->host)
		return -EFAULT;

	inode = page->mapping->host;
	cifs_sb = CIFS_SB(inode->i_sb);
	pTcon = cifs_sb->tcon;

	offset += (loff_t)from;
	write_data = kmap(page);
	write_data += from;

	if ((to > PAGE_CACHE_SIZE) || (from > to)) {
		kunmap(page);
		return -EIO;
	}

	/* racing with truncate? */
	if (offset > mapping->host->i_size) {
		kunmap(page);
		return 0; /* don't care */
	}

	/* check to make sure that we are not extending the file */
	if (mapping->host->i_size - offset < (loff_t)to)
S
Steve French 已提交
1189
		to = (unsigned)(mapping->host->i_size - offset);
L
Linus Torvalds 已提交
1190

1191 1192 1193 1194
	open_file = find_writable_file(CIFS_I(mapping->host));
	if (open_file) {
		bytes_written = cifs_write(open_file->pfile, write_data,
					   to-from, &offset);
1195
		atomic_dec(&open_file->wrtPending);
L
Linus Torvalds 已提交
1196
		/* Does mm or vfs already set times? */
1197
		inode->i_atime = inode->i_mtime = current_fs_time(inode->i_sb);
1198
		if ((bytes_written > 0) && (offset))
1199
			rc = 0;
1200 1201
		else if (bytes_written < 0)
			rc = bytes_written;
1202
	} else {
L
Linus Torvalds 已提交
1203 1204 1205 1206 1207 1208 1209 1210 1211
		cFYI(1, ("No writeable filehandles for inode"));
		rc = -EIO;
	}

	kunmap(page);
	return rc;
}

static int cifs_writepages(struct address_space *mapping,
1212
			   struct writeback_control *wbc)
L
Linus Torvalds 已提交
1213
{
1214 1215 1216 1217 1218
	struct backing_dev_info *bdi = mapping->backing_dev_info;
	unsigned int bytes_to_write;
	unsigned int bytes_written;
	struct cifs_sb_info *cifs_sb;
	int done = 0;
1219
	pgoff_t end;
1220
	pgoff_t index;
S
Steve French 已提交
1221 1222
	int range_whole = 0;
	struct kvec *iov;
1223
	int len;
1224 1225 1226 1227
	int n_iov = 0;
	pgoff_t next;
	int nr_pages;
	__u64 offset = 0;
1228
	struct cifsFileInfo *open_file;
1229 1230 1231 1232
	struct page *page;
	struct pagevec pvec;
	int rc = 0;
	int scanned = 0;
L
Linus Torvalds 已提交
1233 1234
	int xid;

1235
	cifs_sb = CIFS_SB(mapping->host->i_sb);
1236

1237 1238 1239 1240 1241 1242 1243
	/*
	 * If wsize is smaller that the page cache size, default to writing
	 * one page at a time via cifs_writepage
	 */
	if (cifs_sb->wsize < PAGE_CACHE_SIZE)
		return generic_writepages(mapping, wbc);

S
Steve French 已提交
1244 1245 1246 1247
	if ((cifs_sb->tcon->ses) && (cifs_sb->tcon->ses->server))
		if (cifs_sb->tcon->ses->server->secMode &
				(SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED))
			if (!experimEnabled)
1248
				return generic_writepages(mapping, wbc);
1249

1250
	iov = kmalloc(32 * sizeof(struct kvec), GFP_KERNEL);
S
Steve French 已提交
1251
	if (iov == NULL)
1252 1253 1254
		return generic_writepages(mapping, wbc);


1255 1256 1257 1258 1259 1260
	/*
	 * BB: Is this meaningful for a non-block-device file system?
	 * If it is, we should test it again after we do I/O
	 */
	if (wbc->nonblocking && bdi_write_congested(bdi)) {
		wbc->encountered_congestion = 1;
1261
		kfree(iov);
1262 1263 1264
		return 0;
	}

L
Linus Torvalds 已提交
1265 1266
	xid = GetXid();

1267
	pagevec_init(&pvec, 0);
1268
	if (wbc->range_cyclic) {
1269
		index = mapping->writeback_index; /* Start from prev offset */
1270 1271 1272 1273 1274 1275
		end = -1;
	} else {
		index = wbc->range_start >> PAGE_CACHE_SHIFT;
		end = wbc->range_end >> PAGE_CACHE_SHIFT;
		if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
			range_whole = 1;
1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302
		scanned = 1;
	}
retry:
	while (!done && (index <= end) &&
	       (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
			PAGECACHE_TAG_DIRTY,
			min(end - index, (pgoff_t)PAGEVEC_SIZE - 1) + 1))) {
		int first;
		unsigned int i;

		first = -1;
		next = 0;
		n_iov = 0;
		bytes_to_write = 0;

		for (i = 0; i < nr_pages; i++) {
			page = pvec.pages[i];
			/*
			 * At this point we hold neither mapping->tree_lock nor
			 * lock on the page itself: the page may be truncated or
			 * invalidated (changing page->mapping to NULL), or even
			 * swizzled back from swapper_space to tmpfs file
			 * mapping
			 */

			if (first < 0)
				lock_page(page);
N
Nick Piggin 已提交
1303
			else if (!trylock_page(page))
1304 1305 1306 1307 1308 1309 1310
				break;

			if (unlikely(page->mapping != mapping)) {
				unlock_page(page);
				break;
			}

1311
			if (!wbc->range_cyclic && page->index > end) {
1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326
				done = 1;
				unlock_page(page);
				break;
			}

			if (next && (page->index != next)) {
				/* Not next consecutive page */
				unlock_page(page);
				break;
			}

			if (wbc->sync_mode != WB_SYNC_NONE)
				wait_on_page_writeback(page);

			if (PageWriteback(page) ||
1327
					!clear_page_dirty_for_io(page)) {
1328 1329 1330
				unlock_page(page);
				break;
			}
1331

1332 1333 1334 1335 1336 1337
			/*
			 * This actually clears the dirty bit in the radix tree.
			 * See cifs_writepage() for more commentary.
			 */
			set_page_writeback(page);

1338 1339 1340
			if (page_offset(page) >= mapping->host->i_size) {
				done = 1;
				unlock_page(page);
1341
				end_page_writeback(page);
1342 1343 1344
				break;
			}

1345 1346 1347 1348 1349
			/*
			 * BB can we get rid of this?  pages are held by pvec
			 */
			page_cache_get(page);

1350 1351 1352
			len = min(mapping->host->i_size - page_offset(page),
				  (loff_t)PAGE_CACHE_SIZE);

1353 1354 1355
			/* reserve iov[0] for the smb header */
			n_iov++;
			iov[n_iov].iov_base = kmap(page);
1356 1357
			iov[n_iov].iov_len = len;
			bytes_to_write += len;
1358 1359 1360 1361 1362 1363 1364 1365 1366 1367

			if (first < 0) {
				first = i;
				offset = page_offset(page);
			}
			next = page->index + 1;
			if (bytes_to_write + PAGE_CACHE_SIZE > cifs_sb->wsize)
				break;
		}
		if (n_iov) {
1368 1369 1370 1371 1372 1373 1374 1375
			/* Search for a writable handle every time we call
			 * CIFSSMBWrite2.  We can't rely on the last handle
			 * we used to still be valid
			 */
			open_file = find_writable_file(CIFS_I(mapping->host));
			if (!open_file) {
				cERROR(1, ("No writable handles for inode"));
				rc = -EBADF;
S
Steve French 已提交
1376
			} else {
1377 1378 1379 1380
				rc = CIFSSMBWrite2(xid, cifs_sb->tcon,
						   open_file->netfid,
						   bytes_to_write, offset,
						   &bytes_written, iov, n_iov,
1381
						   CIFS_LONG_OP);
1382 1383
				atomic_dec(&open_file->wrtPending);
				if (rc || bytes_written < bytes_to_write) {
1384
					cERROR(1, ("Write2 ret %d, wrote %d",
1385 1386 1387
						  rc, bytes_written));
					/* BB what if continued retry is
					   requested via mount flags? */
1388 1389 1390 1391
					if (rc == -ENOSPC)
						set_bit(AS_ENOSPC, &mapping->flags);
					else
						set_bit(AS_EIO, &mapping->flags);
1392 1393 1394 1395
				} else {
					cifs_stats_bytes_written(cifs_sb->tcon,
								 bytes_written);
				}
1396 1397 1398
			}
			for (i = 0; i < n_iov; i++) {
				page = pvec.pages[first + i];
1399 1400 1401 1402
				/* Should we also set page error on
				success rc but too little data written? */
				/* BB investigate retry logic on temporary
				server crash cases and how recovery works
S
Steve French 已提交
1403 1404
				when page marked as error */
				if (rc)
1405
					SetPageError(page);
1406 1407
				kunmap(page);
				unlock_page(page);
1408
				end_page_writeback(page);
1409 1410 1411 1412 1413
				page_cache_release(page);
			}
			if ((wbc->nr_to_write -= n_iov) <= 0)
				done = 1;
			index = next;
1414 1415 1416 1417
		} else
			/* Need to re-find the pages we skipped */
			index = pvec.pages[0]->index + 1;

1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428
		pagevec_release(&pvec);
	}
	if (!scanned && !done) {
		/*
		 * We hit the last page and there is more work to be done: wrap
		 * back to the start of the file
		 */
		scanned = 1;
		index = 0;
		goto retry;
	}
1429
	if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
1430 1431
		mapping->writeback_index = index;

L
Linus Torvalds 已提交
1432
	FreeXid(xid);
1433
	kfree(iov);
L
Linus Torvalds 已提交
1434 1435 1436
	return rc;
}

S
Steve French 已提交
1437
static int cifs_writepage(struct page *page, struct writeback_control *wbc)
L
Linus Torvalds 已提交
1438 1439 1440 1441 1442 1443 1444
{
	int rc = -EFAULT;
	int xid;

	xid = GetXid();
/* BB add check for wbc flags */
	page_cache_get(page);
S
Steve French 已提交
1445
	if (!PageUptodate(page))
L
Linus Torvalds 已提交
1446
		cFYI(1, ("ppw - page not up to date"));
1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457

	/*
	 * Set the "writeback" flag, and clear "dirty" in the radix tree.
	 *
	 * A writepage() implementation always needs to do either this,
	 * or re-dirty the page with "redirty_page_for_writepage()" in
	 * the case of a failure.
	 *
	 * Just unlocking the page will cause the radix tree tag-bits
	 * to fail to update with the state of the page correctly.
	 */
S
Steve French 已提交
1458
	set_page_writeback(page);
L
Linus Torvalds 已提交
1459 1460 1461
	rc = cifs_partialpagewrite(page, 0, PAGE_CACHE_SIZE);
	SetPageUptodate(page); /* BB add check for error and Clearuptodate? */
	unlock_page(page);
1462 1463
	end_page_writeback(page);
	page_cache_release(page);
L
Linus Torvalds 已提交
1464 1465 1466 1467
	FreeXid(xid);
	return rc;
}

N
Nick Piggin 已提交
1468 1469 1470
static int cifs_write_end(struct file *file, struct address_space *mapping,
			loff_t pos, unsigned len, unsigned copied,
			struct page *page, void *fsdata)
L
Linus Torvalds 已提交
1471
{
N
Nick Piggin 已提交
1472 1473
	int rc;
	struct inode *inode = mapping->host;
L
Linus Torvalds 已提交
1474

N
Nick Piggin 已提交
1475 1476 1477 1478 1479
	cFYI(1, ("write_end for page %p from pos %lld with %d bytes",
		 page, pos, copied));

	if (!PageUptodate(page) && copied == PAGE_CACHE_SIZE)
		SetPageUptodate(page);
S
Steve French 已提交
1480

L
Linus Torvalds 已提交
1481
	if (!PageUptodate(page)) {
N
Nick Piggin 已提交
1482 1483 1484 1485 1486
		char *page_data;
		unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
		int xid;

		xid = GetXid();
L
Linus Torvalds 已提交
1487 1488 1489 1490 1491 1492
		/* this is probably better than directly calling
		   partialpage_write since in this function the file handle is
		   known which we might as well	leverage */
		/* BB check if anything else missing out of ppw
		   such as updating last write time */
		page_data = kmap(page);
N
Nick Piggin 已提交
1493 1494
		rc = cifs_write(file, page_data + offset, copied, &pos);
		/* if (rc < 0) should we set writebehind rc? */
L
Linus Torvalds 已提交
1495
		kunmap(page);
N
Nick Piggin 已提交
1496 1497

		FreeXid(xid);
S
Steve French 已提交
1498
	} else {
N
Nick Piggin 已提交
1499 1500
		rc = copied;
		pos += copied;
L
Linus Torvalds 已提交
1501 1502 1503
		set_page_dirty(page);
	}

N
Nick Piggin 已提交
1504 1505 1506 1507 1508 1509 1510 1511 1512 1513
	if (rc > 0) {
		spin_lock(&inode->i_lock);
		if (pos > inode->i_size)
			i_size_write(inode, pos);
		spin_unlock(&inode->i_lock);
	}

	unlock_page(page);
	page_cache_release(page);

L
Linus Torvalds 已提交
1514 1515 1516 1517 1518 1519 1520
	return rc;
}

int cifs_fsync(struct file *file, struct dentry *dentry, int datasync)
{
	int xid;
	int rc = 0;
1521
	struct inode *inode = file->f_path.dentry->d_inode;
L
Linus Torvalds 已提交
1522 1523 1524

	xid = GetXid();

S
Steve French 已提交
1525
	cFYI(1, ("Sync file - name: %s datasync: 0x%x",
L
Linus Torvalds 已提交
1526
		dentry->d_name.name, datasync));
1527

1528 1529 1530
	rc = filemap_write_and_wait(inode->i_mapping);
	if (rc == 0) {
		rc = CIFS_I(inode)->write_behind_rc;
L
Linus Torvalds 已提交
1531
		CIFS_I(inode)->write_behind_rc = 0;
1532
	}
L
Linus Torvalds 已提交
1533 1534 1535 1536
	FreeXid(xid);
	return rc;
}

1537
/* static void cifs_sync_page(struct page *page)
L
Linus Torvalds 已提交
1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550
{
	struct address_space *mapping;
	struct inode *inode;
	unsigned long index = page->index;
	unsigned int rpages = 0;
	int rc = 0;

	cFYI(1, ("sync page %p",page));
	mapping = page->mapping;
	if (!mapping)
		return 0;
	inode = mapping->host;
	if (!inode)
1551
		return; */
L
Linus Torvalds 已提交
1552

S
Steve French 已提交
1553
/*	fill in rpages then
L
Linus Torvalds 已提交
1554 1555
	result = cifs_pagein_inode(inode, index, rpages); */ /* BB finish */

1556
/*	cFYI(1, ("rpages is %d for sync page of Index %ld", rpages, index));
L
Linus Torvalds 已提交
1557

1558
#if 0
L
Linus Torvalds 已提交
1559 1560 1561
	if (rc < 0)
		return rc;
	return 0;
1562
#endif
L
Linus Torvalds 已提交
1563 1564 1565 1566 1567 1568
} */

/*
 * As file closes, flush all cached write data for this inode checking
 * for write behind errors.
 */
1569
int cifs_flush(struct file *file, fl_owner_t id)
L
Linus Torvalds 已提交
1570
{
S
Steve French 已提交
1571
	struct inode *inode = file->f_path.dentry->d_inode;
L
Linus Torvalds 已提交
1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583
	int rc = 0;

	/* Rather than do the steps manually:
	   lock the inode for writing
	   loop through pages looking for write behind data (dirty pages)
	   coalesce into contiguous 16K (or smaller) chunks to write to server
	   send to server (prefer in parallel)
	   deal with writebehind errors
	   unlock inode for writing
	   filemapfdatawrite appears easier for the time being */

	rc = filemap_fdatawrite(inode->i_mapping);
1584 1585 1586
	/* reset wb rc if we were able to write out dirty pages */
	if (!rc) {
		rc = CIFS_I(inode)->write_behind_rc;
L
Linus Torvalds 已提交
1587
		CIFS_I(inode)->write_behind_rc = 0;
1588
	}
1589

S
Steve French 已提交
1590
	cFYI(1, ("Flush inode %p file %p rc %d", inode, file, rc));
L
Linus Torvalds 已提交
1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610

	return rc;
}

ssize_t cifs_user_read(struct file *file, char __user *read_data,
	size_t read_size, loff_t *poffset)
{
	int rc = -EACCES;
	unsigned int bytes_read = 0;
	unsigned int total_read = 0;
	unsigned int current_read_size;
	struct cifs_sb_info *cifs_sb;
	struct cifsTconInfo *pTcon;
	int xid;
	struct cifsFileInfo *open_file;
	char *smb_read_data;
	char __user *current_offset;
	struct smb_com_read_rsp *pSMBr;

	xid = GetXid();
1611
	cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
L
Linus Torvalds 已提交
1612 1613 1614 1615 1616 1617 1618 1619
	pTcon = cifs_sb->tcon;

	if (file->private_data == NULL) {
		FreeXid(xid);
		return -EBADF;
	}
	open_file = (struct cifsFileInfo *)file->private_data;

S
Steve French 已提交
1620
	if ((file->f_flags & O_ACCMODE) == O_WRONLY)
L
Linus Torvalds 已提交
1621
		cFYI(1, ("attempting read on write only file instance"));
S
Steve French 已提交
1622

L
Linus Torvalds 已提交
1623 1624 1625
	for (total_read = 0, current_offset = read_data;
	     read_size > total_read;
	     total_read += bytes_read, current_offset += bytes_read) {
S
Steve French 已提交
1626
		current_read_size = min_t(const int, read_size - total_read,
L
Linus Torvalds 已提交
1627 1628 1629 1630
					  cifs_sb->rsize);
		rc = -EAGAIN;
		smb_read_data = NULL;
		while (rc == -EAGAIN) {
1631
			int buf_type = CIFS_NO_BUFFER;
S
Steve French 已提交
1632
			if ((open_file->invalidHandle) &&
L
Linus Torvalds 已提交
1633
			    (!open_file->closePend)) {
1634
				rc = cifs_reopen_file(file, true);
L
Linus Torvalds 已提交
1635 1636 1637
				if (rc != 0)
					break;
			}
1638
			rc = CIFSSMBRead(xid, pTcon,
1639 1640 1641 1642
					 open_file->netfid,
					 current_read_size, *poffset,
					 &bytes_read, &smb_read_data,
					 &buf_type);
L
Linus Torvalds 已提交
1643 1644
			pSMBr = (struct smb_com_read_rsp *)smb_read_data;
			if (smb_read_data) {
1645 1646 1647 1648
				if (copy_to_user(current_offset,
						smb_read_data +
						4 /* RFC1001 length field */ +
						le16_to_cpu(pSMBr->DataOffset),
S
Steve French 已提交
1649
						bytes_read))
1650 1651
					rc = -EFAULT;

S
Steve French 已提交
1652
				if (buf_type == CIFS_SMALL_BUFFER)
1653
					cifs_small_buf_release(smb_read_data);
S
Steve French 已提交
1654
				else if (buf_type == CIFS_LARGE_BUFFER)
1655
					cifs_buf_release(smb_read_data);
L
Linus Torvalds 已提交
1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666
				smb_read_data = NULL;
			}
		}
		if (rc || (bytes_read == 0)) {
			if (total_read) {
				break;
			} else {
				FreeXid(xid);
				return rc;
			}
		} else {
1667
			cifs_stats_bytes_read(pTcon, bytes_read);
L
Linus Torvalds 已提交
1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687
			*poffset += bytes_read;
		}
	}
	FreeXid(xid);
	return total_read;
}


static ssize_t cifs_read(struct file *file, char *read_data, size_t read_size,
	loff_t *poffset)
{
	int rc = -EACCES;
	unsigned int bytes_read = 0;
	unsigned int total_read;
	unsigned int current_read_size;
	struct cifs_sb_info *cifs_sb;
	struct cifsTconInfo *pTcon;
	int xid;
	char *current_offset;
	struct cifsFileInfo *open_file;
1688
	int buf_type = CIFS_NO_BUFFER;
L
Linus Torvalds 已提交
1689 1690

	xid = GetXid();
1691
	cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
L
Linus Torvalds 已提交
1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702
	pTcon = cifs_sb->tcon;

	if (file->private_data == NULL) {
		FreeXid(xid);
		return -EBADF;
	}
	open_file = (struct cifsFileInfo *)file->private_data;

	if ((file->f_flags & O_ACCMODE) == O_WRONLY)
		cFYI(1, ("attempting read on write only file instance"));

S
Steve French 已提交
1703
	for (total_read = 0, current_offset = read_data;
L
Linus Torvalds 已提交
1704 1705 1706 1707
	     read_size > total_read;
	     total_read += bytes_read, current_offset += bytes_read) {
		current_read_size = min_t(const int, read_size - total_read,
					  cifs_sb->rsize);
1708 1709
		/* For windows me and 9x we do not want to request more
		than it negotiated since it will refuse the read then */
S
Steve French 已提交
1710
		if ((pTcon->ses) &&
1711 1712 1713 1714
			!(pTcon->ses->capabilities & CAP_LARGE_FILES)) {
			current_read_size = min_t(const int, current_read_size,
					pTcon->ses->server->maxBuf - 128);
		}
L
Linus Torvalds 已提交
1715 1716
		rc = -EAGAIN;
		while (rc == -EAGAIN) {
S
Steve French 已提交
1717
			if ((open_file->invalidHandle) &&
L
Linus Torvalds 已提交
1718
			    (!open_file->closePend)) {
1719
				rc = cifs_reopen_file(file, true);
L
Linus Torvalds 已提交
1720 1721 1722
				if (rc != 0)
					break;
			}
1723
			rc = CIFSSMBRead(xid, pTcon,
1724 1725 1726 1727
					 open_file->netfid,
					 current_read_size, *poffset,
					 &bytes_read, &current_offset,
					 &buf_type);
L
Linus Torvalds 已提交
1728 1729 1730 1731 1732 1733 1734 1735 1736
		}
		if (rc || (bytes_read == 0)) {
			if (total_read) {
				break;
			} else {
				FreeXid(xid);
				return rc;
			}
		} else {
1737
			cifs_stats_bytes_read(pTcon, total_read);
L
Linus Torvalds 已提交
1738 1739 1740 1741 1742 1743 1744 1745 1746
			*poffset += bytes_read;
		}
	}
	FreeXid(xid);
	return total_read;
}

int cifs_file_mmap(struct file *file, struct vm_area_struct *vma)
{
1747
	struct dentry *dentry = file->f_path.dentry;
L
Linus Torvalds 已提交
1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762
	int rc, xid;

	xid = GetXid();
	rc = cifs_revalidate(dentry);
	if (rc) {
		cFYI(1, ("Validation prior to mmap failed, error=%d", rc));
		FreeXid(xid);
		return rc;
	}
	rc = generic_file_mmap(file, vma);
	FreeXid(xid);
	return rc;
}


S
Steve French 已提交
1763
static void cifs_copy_cache_pages(struct address_space *mapping,
L
Linus Torvalds 已提交
1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780
	struct list_head *pages, int bytes_read, char *data,
	struct pagevec *plru_pvec)
{
	struct page *page;
	char *target;

	while (bytes_read > 0) {
		if (list_empty(pages))
			break;

		page = list_entry(pages->prev, struct page, lru);
		list_del(&page->lru);

		if (add_to_page_cache(page, mapping, page->index,
				      GFP_KERNEL)) {
			page_cache_release(page);
			cFYI(1, ("Add page cache failed"));
1781 1782
			data += PAGE_CACHE_SIZE;
			bytes_read -= PAGE_CACHE_SIZE;
L
Linus Torvalds 已提交
1783 1784 1785
			continue;
		}

S
Steve French 已提交
1786
		target = kmap_atomic(page, KM_USER0);
L
Linus Torvalds 已提交
1787 1788 1789 1790

		if (PAGE_CACHE_SIZE > bytes_read) {
			memcpy(target, data, bytes_read);
			/* zero the tail end of this partial page */
S
Steve French 已提交
1791
			memset(target + bytes_read, 0,
L
Linus Torvalds 已提交
1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803
			       PAGE_CACHE_SIZE - bytes_read);
			bytes_read = 0;
		} else {
			memcpy(target, data, PAGE_CACHE_SIZE);
			bytes_read -= PAGE_CACHE_SIZE;
		}
		kunmap_atomic(target, KM_USER0);

		flush_dcache_page(page);
		SetPageUptodate(page);
		unlock_page(page);
		if (!pagevec_add(plru_pvec, page))
1804
			__pagevec_lru_add_file(plru_pvec);
L
Linus Torvalds 已提交
1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818
		data += PAGE_CACHE_SIZE;
	}
	return;
}

static int cifs_readpages(struct file *file, struct address_space *mapping,
	struct list_head *page_list, unsigned num_pages)
{
	int rc = -EACCES;
	int xid;
	loff_t offset;
	struct page *page;
	struct cifs_sb_info *cifs_sb;
	struct cifsTconInfo *pTcon;
S
Steve French 已提交
1819
	unsigned int bytes_read = 0;
S
Steve French 已提交
1820
	unsigned int read_size, i;
L
Linus Torvalds 已提交
1821 1822 1823 1824
	char *smb_read_data = NULL;
	struct smb_com_read_rsp *pSMBr;
	struct pagevec lru_pvec;
	struct cifsFileInfo *open_file;
1825
	int buf_type = CIFS_NO_BUFFER;
L
Linus Torvalds 已提交
1826 1827 1828 1829 1830 1831 1832

	xid = GetXid();
	if (file->private_data == NULL) {
		FreeXid(xid);
		return -EBADF;
	}
	open_file = (struct cifsFileInfo *)file->private_data;
1833
	cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
L
Linus Torvalds 已提交
1834
	pTcon = cifs_sb->tcon;
1835

L
Linus Torvalds 已提交
1836
	pagevec_init(&lru_pvec, 0);
S
Steve French 已提交
1837
	cFYI(DBG2, ("rpages: num pages %d", num_pages));
L
Linus Torvalds 已提交
1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850
	for (i = 0; i < num_pages; ) {
		unsigned contig_pages;
		struct page *tmp_page;
		unsigned long expected_index;

		if (list_empty(page_list))
			break;

		page = list_entry(page_list->prev, struct page, lru);
		offset = (loff_t)page->index << PAGE_CACHE_SHIFT;

		/* count adjacent pages that we will read into */
		contig_pages = 0;
S
Steve French 已提交
1851
		expected_index =
L
Linus Torvalds 已提交
1852
			list_entry(page_list->prev, struct page, lru)->index;
S
Steve French 已提交
1853
		list_for_each_entry_reverse(tmp_page, page_list, lru) {
L
Linus Torvalds 已提交
1854 1855 1856 1857
			if (tmp_page->index == expected_index) {
				contig_pages++;
				expected_index++;
			} else
S
Steve French 已提交
1858
				break;
L
Linus Torvalds 已提交
1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869
		}
		if (contig_pages + i >  num_pages)
			contig_pages = num_pages - i;

		/* for reads over a certain size could initiate async
		   read ahead */

		read_size = contig_pages * PAGE_CACHE_SIZE;
		/* Read size needs to be in multiples of one page */
		read_size = min_t(const unsigned int, read_size,
				  cifs_sb->rsize & PAGE_CACHE_MASK);
1870
		cFYI(DBG2, ("rpages: read size 0x%x  contiguous pages %d",
1871
				read_size, contig_pages));
L
Linus Torvalds 已提交
1872 1873
		rc = -EAGAIN;
		while (rc == -EAGAIN) {
S
Steve French 已提交
1874
			if ((open_file->invalidHandle) &&
L
Linus Torvalds 已提交
1875
			    (!open_file->closePend)) {
1876
				rc = cifs_reopen_file(file, true);
L
Linus Torvalds 已提交
1877 1878 1879 1880
				if (rc != 0)
					break;
			}

1881
			rc = CIFSSMBRead(xid, pTcon,
1882 1883 1884 1885
					 open_file->netfid,
					 read_size, offset,
					 &bytes_read, &smb_read_data,
					 &buf_type);
1886
			/* BB more RC checks ? */
S
Steve French 已提交
1887
			if (rc == -EAGAIN) {
L
Linus Torvalds 已提交
1888
				if (smb_read_data) {
S
Steve French 已提交
1889
					if (buf_type == CIFS_SMALL_BUFFER)
1890
						cifs_small_buf_release(smb_read_data);
S
Steve French 已提交
1891
					else if (buf_type == CIFS_LARGE_BUFFER)
1892
						cifs_buf_release(smb_read_data);
L
Linus Torvalds 已提交
1893 1894 1895 1896 1897 1898 1899 1900
					smb_read_data = NULL;
				}
			}
		}
		if ((rc < 0) || (smb_read_data == NULL)) {
			cFYI(1, ("Read error in readpages: %d", rc));
			break;
		} else if (bytes_read > 0) {
1901
			task_io_account_read(bytes_read);
L
Linus Torvalds 已提交
1902 1903 1904 1905 1906 1907
			pSMBr = (struct smb_com_read_rsp *)smb_read_data;
			cifs_copy_cache_pages(mapping, page_list, bytes_read,
				smb_read_data + 4 /* RFC1001 hdr */ +
				le16_to_cpu(pSMBr->DataOffset), &lru_pvec);

			i +=  bytes_read >> PAGE_CACHE_SHIFT;
1908
			cifs_stats_bytes_read(pTcon, bytes_read);
S
Steve French 已提交
1909
			if ((bytes_read & PAGE_CACHE_MASK) != bytes_read) {
L
Linus Torvalds 已提交
1910 1911
				i++; /* account for partial page */

S
Steve French 已提交
1912
				/* server copy of file can have smaller size
L
Linus Torvalds 已提交
1913
				   than client */
S
Steve French 已提交
1914 1915
				/* BB do we need to verify this common case ?
				   this case is ok - if we are at server EOF
L
Linus Torvalds 已提交
1916 1917
				   we will hit it on next read */

O
OGAWA Hirofumi 已提交
1918
				/* break; */
L
Linus Torvalds 已提交
1919 1920 1921 1922 1923
			}
		} else {
			cFYI(1, ("No bytes read (%d) at offset %lld . "
				 "Cleaning remaining pages from readahead list",
				 bytes_read, offset));
S
Steve French 已提交
1924
			/* BB turn off caching and do new lookup on
L
Linus Torvalds 已提交
1925 1926 1927 1928
			   file size at server? */
			break;
		}
		if (smb_read_data) {
S
Steve French 已提交
1929
			if (buf_type == CIFS_SMALL_BUFFER)
1930
				cifs_small_buf_release(smb_read_data);
S
Steve French 已提交
1931
			else if (buf_type == CIFS_LARGE_BUFFER)
1932
				cifs_buf_release(smb_read_data);
L
Linus Torvalds 已提交
1933 1934 1935 1936 1937
			smb_read_data = NULL;
		}
		bytes_read = 0;
	}

1938
	pagevec_lru_add_file(&lru_pvec);
L
Linus Torvalds 已提交
1939 1940 1941

/* need to free smb_read_data buf before exit */
	if (smb_read_data) {
S
Steve French 已提交
1942
		if (buf_type == CIFS_SMALL_BUFFER)
1943
			cifs_small_buf_release(smb_read_data);
S
Steve French 已提交
1944
		else if (buf_type == CIFS_LARGE_BUFFER)
1945
			cifs_buf_release(smb_read_data);
L
Linus Torvalds 已提交
1946
		smb_read_data = NULL;
S
Steve French 已提交
1947
	}
L
Linus Torvalds 已提交
1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961

	FreeXid(xid);
	return rc;
}

static int cifs_readpage_worker(struct file *file, struct page *page,
	loff_t *poffset)
{
	char *read_data;
	int rc;

	page_cache_get(page);
	read_data = kmap(page);
	/* for reads over a certain size could initiate async read ahead */
S
Steve French 已提交
1962

L
Linus Torvalds 已提交
1963
	rc = cifs_read(file, read_data, PAGE_CACHE_SIZE, poffset);
S
Steve French 已提交
1964

L
Linus Torvalds 已提交
1965 1966 1967
	if (rc < 0)
		goto io_error;
	else
S
Steve French 已提交
1968 1969
		cFYI(1, ("Bytes read %d", rc));

1970 1971
	file->f_path.dentry->d_inode->i_atime =
		current_fs_time(file->f_path.dentry->d_inode->i_sb);
S
Steve French 已提交
1972

L
Linus Torvalds 已提交
1973 1974 1975 1976 1977 1978
	if (PAGE_CACHE_SIZE > rc)
		memset(read_data + rc, 0, PAGE_CACHE_SIZE - rc);

	flush_dcache_page(page);
	SetPageUptodate(page);
	rc = 0;
S
Steve French 已提交
1979

L
Linus Torvalds 已提交
1980
io_error:
S
Steve French 已提交
1981
	kunmap(page);
L
Linus Torvalds 已提交
1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998
	page_cache_release(page);
	return rc;
}

static int cifs_readpage(struct file *file, struct page *page)
{
	loff_t offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
	int rc = -EACCES;
	int xid;

	xid = GetXid();

	if (file->private_data == NULL) {
		FreeXid(xid);
		return -EBADF;
	}

S
Steve French 已提交
1999
	cFYI(1, ("readpage %p at offset %d 0x%x\n",
L
Linus Torvalds 已提交
2000 2001 2002 2003 2004 2005 2006 2007 2008 2009
		 page, (int)offset, (int)offset));

	rc = cifs_readpage_worker(file, page, &offset);

	unlock_page(page);

	FreeXid(xid);
	return rc;
}

2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028
static int is_inode_writable(struct cifsInodeInfo *cifs_inode)
{
	struct cifsFileInfo *open_file;

	read_lock(&GlobalSMBSeslock);
	list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
		if (open_file->closePend)
			continue;
		if (open_file->pfile &&
		    ((open_file->pfile->f_flags & O_RDWR) ||
		     (open_file->pfile->f_flags & O_WRONLY))) {
			read_unlock(&GlobalSMBSeslock);
			return 1;
		}
	}
	read_unlock(&GlobalSMBSeslock);
	return 0;
}

L
Linus Torvalds 已提交
2029 2030 2031
/* We do not want to update the file size from server for inodes
   open for write - to avoid races with writepage extending
   the file - in the future we could consider allowing
S
Steve French 已提交
2032
   refreshing the inode only on increases in the file size
L
Linus Torvalds 已提交
2033 2034
   but this is tricky to do without racing with writebehind
   page caching in the current Linux kernel design */
2035
bool is_size_safe_to_change(struct cifsInodeInfo *cifsInode, __u64 end_of_file)
L
Linus Torvalds 已提交
2036
{
2037
	if (!cifsInode)
2038
		return true;
2039

2040 2041
	if (is_inode_writable(cifsInode)) {
		/* This inode is open for write at least once */
2042 2043 2044
		struct cifs_sb_info *cifs_sb;

		cifs_sb = CIFS_SB(cifsInode->vfs_inode.i_sb);
S
Steve French 已提交
2045
		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DIRECT_IO) {
S
Steve French 已提交
2046
			/* since no page cache to corrupt on directio
2047
			we can change size safely */
2048
			return true;
2049 2050
		}

S
Steve French 已提交
2051
		if (i_size_read(&cifsInode->vfs_inode) < end_of_file)
2052
			return true;
2053

2054
		return false;
2055
	} else
2056
		return true;
L
Linus Torvalds 已提交
2057 2058
}

N
Nick Piggin 已提交
2059 2060 2061
static int cifs_write_begin(struct file *file, struct address_space *mapping,
			loff_t pos, unsigned len, unsigned flags,
			struct page **pagep, void **fsdata)
L
Linus Torvalds 已提交
2062
{
N
Nick Piggin 已提交
2063 2064 2065 2066 2067 2068 2069 2070
	pgoff_t index = pos >> PAGE_CACHE_SHIFT;
	loff_t offset = pos & (PAGE_CACHE_SIZE - 1);

	cFYI(1, ("write_begin from %lld len %d", (long long)pos, len));

	*pagep = __grab_cache_page(mapping, index);
	if (!*pagep)
		return -ENOMEM;
2071

N
Nick Piggin 已提交
2072
	if (PageUptodate(*pagep))
2073 2074 2075 2076
		return 0;

	/* If we are writing a full page it will be up to date,
	   no need to read from the server */
N
Nick Piggin 已提交
2077
	if (len == PAGE_CACHE_SIZE && flags & AOP_FLAG_UNINTERRUPTIBLE)
2078 2079
		return 0;

N
Nick Piggin 已提交
2080 2081
	if ((file->f_flags & O_ACCMODE) != O_WRONLY) {
		int rc;
2082

L
Linus Torvalds 已提交
2083
		/* might as well read a page, it is fast enough */
N
Nick Piggin 已提交
2084 2085 2086 2087 2088 2089
		rc = cifs_readpage_worker(file, *pagep, &offset);

		/* we do not need to pass errors back
		   e.g. if we do not have read access to the file
		   because cifs_write_end will attempt synchronous writes
		   -- shaggy */
2090 2091 2092 2093
	} else {
		/* we could try using another file handle if there is one -
		   but how would we lock it to prevent close of that handle
		   racing with this read? In any case
N
Nick Piggin 已提交
2094
		   this will be written out by write_end so is fine */
L
Linus Torvalds 已提交
2095 2096 2097 2098 2099
	}

	return 0;
}

2100
const struct address_space_operations cifs_addr_ops = {
L
Linus Torvalds 已提交
2101 2102 2103
	.readpage = cifs_readpage,
	.readpages = cifs_readpages,
	.writepage = cifs_writepage,
2104
	.writepages = cifs_writepages,
N
Nick Piggin 已提交
2105 2106
	.write_begin = cifs_write_begin,
	.write_end = cifs_write_end,
L
Linus Torvalds 已提交
2107 2108 2109 2110
	.set_page_dirty = __set_page_dirty_nobuffers,
	/* .sync_page = cifs_sync_page, */
	/* .direct_IO = */
};
D
Dave Kleikamp 已提交
2111 2112 2113 2114 2115 2116

/*
 * cifs_readpages requires the server to support a buffer large enough to
 * contain the header plus one complete page of data.  Otherwise, we need
 * to leave cifs_readpages out of the address space operations.
 */
2117
const struct address_space_operations cifs_addr_ops_smallbuf = {
D
Dave Kleikamp 已提交
2118 2119 2120
	.readpage = cifs_readpage,
	.writepage = cifs_writepage,
	.writepages = cifs_writepages,
N
Nick Piggin 已提交
2121 2122
	.write_begin = cifs_write_begin,
	.write_end = cifs_write_end,
D
Dave Kleikamp 已提交
2123 2124 2125 2126
	.set_page_dirty = __set_page_dirty_nobuffers,
	/* .sync_page = cifs_sync_page, */
	/* .direct_IO = */
};