1/*
   2 *   fs/cifs/file.c
   3 *
   4 *   vfs operations that deal with files
   5 *
   6 *   Copyright (C) International Business Machines  Corp., 2002,2010
   7 *   Author(s): Steve French (sfrench@us.ibm.com)
   8 *              Jeremy Allison (jra@samba.org)
   9 *
  10 *   This library is free software; you can redistribute it and/or modify
  11 *   it under the terms of the GNU Lesser General Public License as published
  12 *   by the Free Software Foundation; either version 2.1 of the License, or
  13 *   (at your option) any later version.
  14 *
  15 *   This library is distributed in the hope that it will be useful,
  16 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  18 *   the GNU Lesser General Public License for more details.
  19 *
  20 *   You should have received a copy of the GNU Lesser General Public License
  21 *   along with this library; if not, write to the Free Software
  22 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  23 */
  24#include <linux/fs.h>
  25#include <linux/backing-dev.h>
  26#include <linux/stat.h>
  27#include <linux/fcntl.h>
  28#include <linux/pagemap.h>
  29#include <linux/pagevec.h>
  30#include <linux/writeback.h>
  31#include <linux/task_io_accounting_ops.h>
  32#include <linux/delay.h>
  33#include <linux/mount.h>
  34#include <linux/slab.h>
 
  35#include <asm/div64.h>
  36#include "cifsfs.h"
  37#include "cifspdu.h"
  38#include "cifsglob.h"
  39#include "cifsproto.h"
  40#include "cifs_unicode.h"
  41#include "cifs_debug.h"
  42#include "cifs_fs_sb.h"
  43#include "fscache.h"
  44
  45static inline int cifs_convert_flags(unsigned int flags)
  46{
  47	if ((flags & O_ACCMODE) == O_RDONLY)
  48		return GENERIC_READ;
  49	else if ((flags & O_ACCMODE) == O_WRONLY)
  50		return GENERIC_WRITE;
  51	else if ((flags & O_ACCMODE) == O_RDWR) {
  52		/* GENERIC_ALL is too much permission to request
  53		   can cause unnecessary access denied on create */
  54		/* return GENERIC_ALL; */
  55		return (GENERIC_READ | GENERIC_WRITE);
  56	}
  57
  58	return (READ_CONTROL | FILE_WRITE_ATTRIBUTES | FILE_READ_ATTRIBUTES |
  59		FILE_WRITE_EA | FILE_APPEND_DATA | FILE_WRITE_DATA |
  60		FILE_READ_DATA);
  61}
  62
  63static u32 cifs_posix_convert_flags(unsigned int flags)
  64{
  65	u32 posix_flags = 0;
  66
  67	if ((flags & O_ACCMODE) == O_RDONLY)
  68		posix_flags = SMB_O_RDONLY;
  69	else if ((flags & O_ACCMODE) == O_WRONLY)
  70		posix_flags = SMB_O_WRONLY;
  71	else if ((flags & O_ACCMODE) == O_RDWR)
  72		posix_flags = SMB_O_RDWR;
  73
  74	if (flags & O_CREAT)
  75		posix_flags |= SMB_O_CREAT;
  76	if (flags & O_EXCL)
  77		posix_flags |= SMB_O_EXCL;
  78	if (flags & O_TRUNC)
  79		posix_flags |= SMB_O_TRUNC;
  80	/* be safe and imply O_SYNC for O_DSYNC */
  81	if (flags & O_DSYNC)
  82		posix_flags |= SMB_O_SYNC;
  83	if (flags & O_DIRECTORY)
  84		posix_flags |= SMB_O_DIRECTORY;
  85	if (flags & O_NOFOLLOW)
  86		posix_flags |= SMB_O_NOFOLLOW;
  87	if (flags & O_DIRECT)
  88		posix_flags |= SMB_O_DIRECT;
  89
  90	return posix_flags;
  91}
  92
  93static inline int cifs_get_disposition(unsigned int flags)
  94{
  95	if ((flags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
  96		return FILE_CREATE;
  97	else if ((flags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
  98		return FILE_OVERWRITE_IF;
  99	else if ((flags & O_CREAT) == O_CREAT)
 100		return FILE_OPEN_IF;
 101	else if ((flags & O_TRUNC) == O_TRUNC)
 102		return FILE_OVERWRITE;
 103	else
 104		return FILE_OPEN;
 105}
 106
 107int cifs_posix_open(char *full_path, struct inode **pinode,
 108			struct super_block *sb, int mode, unsigned int f_flags,
 109			__u32 *poplock, __u16 *pnetfid, int xid)
 110{
 111	int rc;
 112	FILE_UNIX_BASIC_INFO *presp_data;
 113	__u32 posix_flags = 0;
 114	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
 115	struct cifs_fattr fattr;
 116	struct tcon_link *tlink;
 117	struct cifs_tcon *tcon;
 118
 119	cFYI(1, "posix open %s", full_path);
 120
 121	presp_data = kzalloc(sizeof(FILE_UNIX_BASIC_INFO), GFP_KERNEL);
 122	if (presp_data == NULL)
 123		return -ENOMEM;
 124
 125	tlink = cifs_sb_tlink(cifs_sb);
 126	if (IS_ERR(tlink)) {
 127		rc = PTR_ERR(tlink);
 128		goto posix_open_ret;
 129	}
 130
 131	tcon = tlink_tcon(tlink);
 132	mode &= ~current_umask();
 133
 134	posix_flags = cifs_posix_convert_flags(f_flags);
 135	rc = CIFSPOSIXCreate(xid, tcon, posix_flags, mode, pnetfid, presp_data,
 136			     poplock, full_path, cifs_sb->local_nls,
 137			     cifs_sb->mnt_cifs_flags &
 138					CIFS_MOUNT_MAP_SPECIAL_CHR);
 139	cifs_put_tlink(tlink);
 140
 141	if (rc)
 142		goto posix_open_ret;
 143
 144	if (presp_data->Type == cpu_to_le32(-1))
 145		goto posix_open_ret; /* open ok, caller does qpathinfo */
 146
 147	if (!pinode)
 148		goto posix_open_ret; /* caller does not need info */
 149
 150	cifs_unix_basic_to_fattr(&fattr, presp_data, cifs_sb);
 151
 152	/* get new inode and set it up */
 153	if (*pinode == NULL) {
 154		cifs_fill_uniqueid(sb, &fattr);
 155		*pinode = cifs_iget(sb, &fattr);
 156		if (!*pinode) {
 157			rc = -ENOMEM;
 158			goto posix_open_ret;
 159		}
 160	} else {
 161		cifs_fattr_to_inode(*pinode, &fattr);
 162	}
 163
 164posix_open_ret:
 165	kfree(presp_data);
 166	return rc;
 167}
 168
 169static int
 170cifs_nt_open(char *full_path, struct inode *inode, struct cifs_sb_info *cifs_sb,
 171	     struct cifs_tcon *tcon, unsigned int f_flags, __u32 *poplock,
 172	     __u16 *pnetfid, int xid)
 173{
 174	int rc;
 175	int desiredAccess;
 176	int disposition;
 
 177	FILE_ALL_INFO *buf;
 178
 179	desiredAccess = cifs_convert_flags(f_flags);
 180
 181/*********************************************************************
 182 *  open flag mapping table:
 183 *
 184 *	POSIX Flag            CIFS Disposition
 185 *	----------            ----------------
 186 *	O_CREAT               FILE_OPEN_IF
 187 *	O_CREAT | O_EXCL      FILE_CREATE
 188 *	O_CREAT | O_TRUNC     FILE_OVERWRITE_IF
 189 *	O_TRUNC               FILE_OVERWRITE
 190 *	none of the above     FILE_OPEN
 191 *
 192 *	Note that there is not a direct match between disposition
 193 *	FILE_SUPERSEDE (ie create whether or not file exists although
 194 *	O_CREAT | O_TRUNC is similar but truncates the existing
 195 *	file rather than creating a new file as FILE_SUPERSEDE does
 196 *	(which uses the attributes / metadata passed in on open call)
 197 *?
 198 *?  O_SYNC is a reasonable match to CIFS writethrough flag
 199 *?  and the read write flags match reasonably.  O_LARGEFILE
 200 *?  is irrelevant because largefile support is always used
 201 *?  by this client. Flags O_APPEND, O_DIRECT, O_DIRECTORY,
 202 *	 O_FASYNC, O_NOFOLLOW, O_NONBLOCK need further investigation
 203 *********************************************************************/
 204
 205	disposition = cifs_get_disposition(f_flags);
 206
 207	/* BB pass O_SYNC flag through on file attributes .. BB */
 208
 209	buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
 210	if (!buf)
 211		return -ENOMEM;
 212
 
 
 
 213	if (tcon->ses->capabilities & CAP_NT_SMBS)
 214		rc = CIFSSMBOpen(xid, tcon, full_path, disposition,
 215			 desiredAccess, CREATE_NOT_DIR, pnetfid, poplock, buf,
 216			 cifs_sb->local_nls, cifs_sb->mnt_cifs_flags
 217				 & CIFS_MOUNT_MAP_SPECIAL_CHR);
 218	else
 219		rc = SMBLegacyOpen(xid, tcon, full_path, disposition,
 220			desiredAccess, CREATE_NOT_DIR, pnetfid, poplock, buf,
 221			cifs_sb->local_nls, cifs_sb->mnt_cifs_flags
 222				& CIFS_MOUNT_MAP_SPECIAL_CHR);
 223
 224	if (rc)
 225		goto out;
 226
 227	if (tcon->unix_ext)
 228		rc = cifs_get_inode_info_unix(&inode, full_path, inode->i_sb,
 229					      xid);
 230	else
 231		rc = cifs_get_inode_info(&inode, full_path, buf, inode->i_sb,
 232					 xid, pnetfid);
 233
 234out:
 235	kfree(buf);
 236	return rc;
 237}
 238
 239struct cifsFileInfo *
 240cifs_new_fileinfo(__u16 fileHandle, struct file *file,
 241		  struct tcon_link *tlink, __u32 oplock)
 242{
 243	struct dentry *dentry = file->f_path.dentry;
 244	struct inode *inode = dentry->d_inode;
 245	struct cifsInodeInfo *pCifsInode = CIFS_I(inode);
 246	struct cifsFileInfo *pCifsFile;
 247
 248	pCifsFile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
 249	if (pCifsFile == NULL)
 250		return pCifsFile;
 251
 252	pCifsFile->count = 1;
 253	pCifsFile->netfid = fileHandle;
 254	pCifsFile->pid = current->tgid;
 255	pCifsFile->uid = current_fsuid();
 256	pCifsFile->dentry = dget(dentry);
 257	pCifsFile->f_flags = file->f_flags;
 258	pCifsFile->invalidHandle = false;
 259	pCifsFile->tlink = cifs_get_tlink(tlink);
 260	mutex_init(&pCifsFile->fh_mutex);
 261	mutex_init(&pCifsFile->lock_mutex);
 262	INIT_LIST_HEAD(&pCifsFile->llist);
 263	INIT_WORK(&pCifsFile->oplock_break, cifs_oplock_break);
 
 264
 265	spin_lock(&cifs_file_list_lock);
 266	list_add(&pCifsFile->tlist, &(tlink_tcon(tlink)->openFileList));
 267	/* if readable file instance put first in list*/
 268	if (file->f_mode & FMODE_READ)
 269		list_add(&pCifsFile->flist, &pCifsInode->openFileList);
 270	else
 271		list_add_tail(&pCifsFile->flist, &pCifsInode->openFileList);
 272	spin_unlock(&cifs_file_list_lock);
 273
 274	cifs_set_oplock_level(pCifsInode, oplock);
 
 275
 276	file->private_data = pCifsFile;
 277	return pCifsFile;
 278}
 279
 
 
 
 
 
 
 
 
 
 
 
 280/*
 281 * Release a reference on the file private data. This may involve closing
 282 * the filehandle out on the server. Must be called without holding
 283 * cifs_file_list_lock.
 284 */
 285void cifsFileInfo_put(struct cifsFileInfo *cifs_file)
 286{
 287	struct inode *inode = cifs_file->dentry->d_inode;
 288	struct cifs_tcon *tcon = tlink_tcon(cifs_file->tlink);
 289	struct cifsInodeInfo *cifsi = CIFS_I(inode);
 290	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
 291	struct cifsLockInfo *li, *tmp;
 292
 293	spin_lock(&cifs_file_list_lock);
 294	if (--cifs_file->count > 0) {
 295		spin_unlock(&cifs_file_list_lock);
 296		return;
 297	}
 298
 299	/* remove it from the lists */
 300	list_del(&cifs_file->flist);
 301	list_del(&cifs_file->tlist);
 302
 303	if (list_empty(&cifsi->openFileList)) {
 304		cFYI(1, "closing last open instance for inode %p",
 305			cifs_file->dentry->d_inode);
 306
 307		/* in strict cache mode we need invalidate mapping on the last
 308		   close  because it may cause a error when we open this file
 309		   again and get at least level II oplock */
 310		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_STRICT_IO)
 311			CIFS_I(inode)->invalid_mapping = true;
 312
 313		cifs_set_oplock_level(cifsi, 0);
 314	}
 315	spin_unlock(&cifs_file_list_lock);
 316
 317	cancel_work_sync(&cifs_file->oplock_break);
 318
 319	if (!tcon->need_reconnect && !cifs_file->invalidHandle) {
 320		int xid, rc;
 321
 322		xid = GetXid();
 323		rc = CIFSSMBClose(xid, tcon, cifs_file->netfid);
 324		FreeXid(xid);
 325	}
 326
 327	/* Delete any outstanding lock records. We'll lose them when the file
 328	 * is closed anyway.
 329	 */
 330	mutex_lock(&cifs_file->lock_mutex);
 331	list_for_each_entry_safe(li, tmp, &cifs_file->llist, llist) {
 332		list_del(&li->llist);
 
 333		kfree(li);
 334	}
 335	mutex_unlock(&cifs_file->lock_mutex);
 336
 337	cifs_put_tlink(cifs_file->tlink);
 338	dput(cifs_file->dentry);
 339	kfree(cifs_file);
 340}
 341
 342int cifs_open(struct inode *inode, struct file *file)
 343{
 344	int rc = -EACCES;
 345	int xid;
 346	__u32 oplock;
 347	struct cifs_sb_info *cifs_sb;
 348	struct cifs_tcon *tcon;
 349	struct tcon_link *tlink;
 350	struct cifsFileInfo *pCifsFile = NULL;
 351	char *full_path = NULL;
 352	bool posix_open_ok = false;
 353	__u16 netfid;
 354
 355	xid = GetXid();
 356
 357	cifs_sb = CIFS_SB(inode->i_sb);
 358	tlink = cifs_sb_tlink(cifs_sb);
 359	if (IS_ERR(tlink)) {
 360		FreeXid(xid);
 361		return PTR_ERR(tlink);
 362	}
 363	tcon = tlink_tcon(tlink);
 364
 365	full_path = build_path_from_dentry(file->f_path.dentry);
 366	if (full_path == NULL) {
 367		rc = -ENOMEM;
 368		goto out;
 369	}
 370
 371	cFYI(1, "inode = 0x%p file flags are 0x%x for %s",
 372		 inode, file->f_flags, full_path);
 373
 374	if (oplockEnabled)
 375		oplock = REQ_OPLOCK;
 376	else
 377		oplock = 0;
 378
 379	if (!tcon->broken_posix_open && tcon->unix_ext &&
 380	    (tcon->ses->capabilities & CAP_UNIX) &&
 381	    (CIFS_UNIX_POSIX_PATH_OPS_CAP &
 382			le64_to_cpu(tcon->fsUnixInfo.Capability))) {
 383		/* can not refresh inode info since size could be stale */
 384		rc = cifs_posix_open(full_path, &inode, inode->i_sb,
 385				cifs_sb->mnt_file_mode /* ignored */,
 386				file->f_flags, &oplock, &netfid, xid);
 387		if (rc == 0) {
 388			cFYI(1, "posix open succeeded");
 389			posix_open_ok = true;
 390		} else if ((rc == -EINVAL) || (rc == -EOPNOTSUPP)) {
 391			if (tcon->ses->serverNOS)
 392				cERROR(1, "server %s of type %s returned"
 393					   " unexpected error on SMB posix open"
 394					   ", disabling posix open support."
 395					   " Check if server update available.",
 396					   tcon->ses->serverName,
 397					   tcon->ses->serverNOS);
 398			tcon->broken_posix_open = true;
 399		} else if ((rc != -EIO) && (rc != -EREMOTE) &&
 400			 (rc != -EOPNOTSUPP)) /* path not found or net err */
 401			goto out;
 402		/* else fallthrough to retry open the old way on network i/o
 403		   or DFS errors */
 404	}
 405
 406	if (!posix_open_ok) {
 407		rc = cifs_nt_open(full_path, inode, cifs_sb, tcon,
 408				  file->f_flags, &oplock, &netfid, xid);
 409		if (rc)
 410			goto out;
 411	}
 412
 413	pCifsFile = cifs_new_fileinfo(netfid, file, tlink, oplock);
 414	if (pCifsFile == NULL) {
 415		CIFSSMBClose(xid, tcon, netfid);
 416		rc = -ENOMEM;
 417		goto out;
 418	}
 419
 420	cifs_fscache_set_inode_cookie(inode, file);
 421
 422	if ((oplock & CIFS_CREATE_ACTION) && !posix_open_ok && tcon->unix_ext) {
 423		/* time to set mode which we can not set earlier due to
 424		   problems creating new read-only files */
 425		struct cifs_unix_set_info_args args = {
 426			.mode	= inode->i_mode,
 427			.uid	= NO_CHANGE_64,
 428			.gid	= NO_CHANGE_64,
 429			.ctime	= NO_CHANGE_64,
 430			.atime	= NO_CHANGE_64,
 431			.mtime	= NO_CHANGE_64,
 432			.device	= 0,
 433		};
 434		CIFSSMBUnixSetFileInfo(xid, tcon, &args, netfid,
 435					pCifsFile->pid);
 436	}
 437
 438out:
 439	kfree(full_path);
 440	FreeXid(xid);
 441	cifs_put_tlink(tlink);
 442	return rc;
 443}
 444
 445/* Try to reacquire byte range locks that were released when session */
 446/* to server was lost */
 447static int cifs_relock_file(struct cifsFileInfo *cifsFile)
 448{
 449	int rc = 0;
 450
 451/* BB list all locks open on this file and relock */
 452
 453	return rc;
 454}
 455
 456static int cifs_reopen_file(struct cifsFileInfo *pCifsFile, bool can_flush)
 457{
 458	int rc = -EACCES;
 459	int xid;
 460	__u32 oplock;
 461	struct cifs_sb_info *cifs_sb;
 462	struct cifs_tcon *tcon;
 463	struct cifsInodeInfo *pCifsInode;
 464	struct inode *inode;
 465	char *full_path = NULL;
 466	int desiredAccess;
 467	int disposition = FILE_OPEN;
 
 468	__u16 netfid;
 469
 470	xid = GetXid();
 471	mutex_lock(&pCifsFile->fh_mutex);
 472	if (!pCifsFile->invalidHandle) {
 473		mutex_unlock(&pCifsFile->fh_mutex);
 474		rc = 0;
 475		FreeXid(xid);
 476		return rc;
 477	}
 478
 479	inode = pCifsFile->dentry->d_inode;
 480	cifs_sb = CIFS_SB(inode->i_sb);
 481	tcon = tlink_tcon(pCifsFile->tlink);
 482
 483/* can not grab rename sem here because various ops, including
 484   those that already have the rename sem can end up causing writepage
 485   to get called and if the server was down that means we end up here,
 486   and we can never tell if the caller already has the rename_sem */
 487	full_path = build_path_from_dentry(pCifsFile->dentry);
 488	if (full_path == NULL) {
 489		rc = -ENOMEM;
 490		mutex_unlock(&pCifsFile->fh_mutex);
 491		FreeXid(xid);
 492		return rc;
 493	}
 494
 495	cFYI(1, "inode = 0x%p file flags 0x%x for %s",
 496		 inode, pCifsFile->f_flags, full_path);
 497
 498	if (oplockEnabled)
 499		oplock = REQ_OPLOCK;
 500	else
 501		oplock = 0;
 502
 503	if (tcon->unix_ext && (tcon->ses->capabilities & CAP_UNIX) &&
 504	    (CIFS_UNIX_POSIX_PATH_OPS_CAP &
 505			le64_to_cpu(tcon->fsUnixInfo.Capability))) {
 506
 507		/*
 508		 * O_CREAT, O_EXCL and O_TRUNC already had their effect on the
 509		 * original open. Must mask them off for a reopen.
 510		 */
 511		unsigned int oflags = pCifsFile->f_flags &
 512						~(O_CREAT | O_EXCL | O_TRUNC);
 513
 514		rc = cifs_posix_open(full_path, NULL, inode->i_sb,
 515				cifs_sb->mnt_file_mode /* ignored */,
 516				oflags, &oplock, &netfid, xid);
 517		if (rc == 0) {
 518			cFYI(1, "posix reopen succeeded");
 519			goto reopen_success;
 520		}
 521		/* fallthrough to retry open the old way on errors, especially
 522		   in the reconnect path it is important to retry hard */
 523	}
 524
 525	desiredAccess = cifs_convert_flags(pCifsFile->f_flags);
 526
 
 
 
 527	/* Can not refresh inode by passing in file_info buf to be returned
 528	   by SMBOpen and then calling get_inode_info with returned buf
 529	   since file might have write behind data that needs to be flushed
 530	   and server version of file size can be stale. If we knew for sure
 531	   that inode was not dirty locally we could do this */
 532
 533	rc = CIFSSMBOpen(xid, tcon, full_path, disposition, desiredAccess,
 534			 CREATE_NOT_DIR, &netfid, &oplock, NULL,
 535			 cifs_sb->local_nls, cifs_sb->mnt_cifs_flags &
 536				CIFS_MOUNT_MAP_SPECIAL_CHR);
 537	if (rc) {
 538		mutex_unlock(&pCifsFile->fh_mutex);
 539		cFYI(1, "cifs_open returned 0x%x", rc);
 540		cFYI(1, "oplock: %d", oplock);
 541		goto reopen_error_exit;
 542	}
 543
 544reopen_success:
 545	pCifsFile->netfid = netfid;
 546	pCifsFile->invalidHandle = false;
 547	mutex_unlock(&pCifsFile->fh_mutex);
 548	pCifsInode = CIFS_I(inode);
 549
 550	if (can_flush) {
 551		rc = filemap_write_and_wait(inode->i_mapping);
 552		mapping_set_error(inode->i_mapping, rc);
 553
 554		if (tcon->unix_ext)
 555			rc = cifs_get_inode_info_unix(&inode,
 556				full_path, inode->i_sb, xid);
 557		else
 558			rc = cifs_get_inode_info(&inode,
 559				full_path, NULL, inode->i_sb,
 560				xid, NULL);
 561	} /* else we are writing out data to server already
 562	     and could deadlock if we tried to flush data, and
 563	     since we do not know if we have data that would
 564	     invalidate the current end of file on the server
 565	     we can not go to the server to get the new inod
 566	     info */
 567
 568	cifs_set_oplock_level(pCifsInode, oplock);
 569
 570	cifs_relock_file(pCifsFile);
 571
 572reopen_error_exit:
 573	kfree(full_path);
 574	FreeXid(xid);
 575	return rc;
 576}
 577
 578int cifs_close(struct inode *inode, struct file *file)
 579{
 580	if (file->private_data != NULL) {
 581		cifsFileInfo_put(file->private_data);
 582		file->private_data = NULL;
 583	}
 584
 585	/* return code from the ->release op is always ignored */
 586	return 0;
 587}
 588
 589int cifs_closedir(struct inode *inode, struct file *file)
 590{
 591	int rc = 0;
 592	int xid;
 593	struct cifsFileInfo *pCFileStruct = file->private_data;
 594	char *ptmp;
 595
 596	cFYI(1, "Closedir inode = 0x%p", inode);
 597
 598	xid = GetXid();
 599
 600	if (pCFileStruct) {
 601		struct cifs_tcon *pTcon = tlink_tcon(pCFileStruct->tlink);
 602
 603		cFYI(1, "Freeing private data in close dir");
 604		spin_lock(&cifs_file_list_lock);
 605		if (!pCFileStruct->srch_inf.endOfSearch &&
 606		    !pCFileStruct->invalidHandle) {
 607			pCFileStruct->invalidHandle = true;
 608			spin_unlock(&cifs_file_list_lock);
 609			rc = CIFSFindClose(xid, pTcon, pCFileStruct->netfid);
 610			cFYI(1, "Closing uncompleted readdir with rc %d",
 611				 rc);
 612			/* not much we can do if it fails anyway, ignore rc */
 613			rc = 0;
 614		} else
 615			spin_unlock(&cifs_file_list_lock);
 616		ptmp = pCFileStruct->srch_inf.ntwrk_buf_start;
 617		if (ptmp) {
 618			cFYI(1, "closedir free smb buf in srch struct");
 619			pCFileStruct->srch_inf.ntwrk_buf_start = NULL;
 620			if (pCFileStruct->srch_inf.smallBuf)
 621				cifs_small_buf_release(ptmp);
 622			else
 623				cifs_buf_release(ptmp);
 624		}
 625		cifs_put_tlink(pCFileStruct->tlink);
 626		kfree(file->private_data);
 627		file->private_data = NULL;
 628	}
 629	/* BB can we lock the filestruct while this is going on? */
 630	FreeXid(xid);
 631	return rc;
 632}
 633
 634static int store_file_lock(struct cifsFileInfo *fid, __u64 len,
 635				__u64 offset, __u8 lockType)
 636{
 637	struct cifsLockInfo *li =
 638		kmalloc(sizeof(struct cifsLockInfo), GFP_KERNEL);
 639	if (li == NULL)
 640		return -ENOMEM;
 641	li->offset = offset;
 642	li->length = len;
 643	li->type = lockType;
 644	mutex_lock(&fid->lock_mutex);
 645	list_add(&li->llist, &fid->llist);
 646	mutex_unlock(&fid->lock_mutex);
 647	return 0;
 648}
 649
 650int cifs_lock(struct file *file, int cmd, struct file_lock *pfLock)
 
 651{
 652	int rc, xid;
 653	__u32 numLock = 0;
 654	__u32 numUnlock = 0;
 655	__u64 length;
 656	bool wait_flag = false;
 657	struct cifs_sb_info *cifs_sb;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 658	struct cifs_tcon *tcon;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 659	__u16 netfid;
 660	__u8 lockType = LOCKING_ANDX_LARGE_FILES;
 661	bool posix_locking = 0;
 
 
 
 
 
 
 
 
 
 
 
 
 662
 663	length = 1 + pfLock->fl_end - pfLock->fl_start;
 664	rc = -EACCES;
 665	xid = GetXid();
 666
 667	cFYI(1, "Lock parm: 0x%x flockflags: "
 668		 "0x%x flocktype: 0x%x start: %lld end: %lld",
 669		cmd, pfLock->fl_flags, pfLock->fl_type, pfLock->fl_start,
 670		pfLock->fl_end);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 671
 672	if (pfLock->fl_flags & FL_POSIX)
 
 
 
 
 
 
 
 
 
 
 
 
 673		cFYI(1, "Posix");
 674	if (pfLock->fl_flags & FL_FLOCK)
 675		cFYI(1, "Flock");
 676	if (pfLock->fl_flags & FL_SLEEP) {
 677		cFYI(1, "Blocking lock");
 678		wait_flag = true;
 679	}
 680	if (pfLock->fl_flags & FL_ACCESS)
 681		cFYI(1, "Process suspended by mandatory locking - "
 682			 "not implemented yet");
 683	if (pfLock->fl_flags & FL_LEASE)
 684		cFYI(1, "Lease on file - not implemented yet");
 685	if (pfLock->fl_flags &
 686	    (~(FL_POSIX | FL_FLOCK | FL_SLEEP | FL_ACCESS | FL_LEASE)))
 687		cFYI(1, "Unknown lock flags 0x%x", pfLock->fl_flags);
 688
 689	if (pfLock->fl_type == F_WRLCK) {
 
 690		cFYI(1, "F_WRLCK ");
 691		numLock = 1;
 692	} else if (pfLock->fl_type == F_UNLCK) {
 
 693		cFYI(1, "F_UNLCK");
 694		numUnlock = 1;
 695		/* Check if unlock includes more than
 696		one lock range */
 697	} else if (pfLock->fl_type == F_RDLCK) {
 698		cFYI(1, "F_RDLCK");
 699		lockType |= LOCKING_ANDX_SHARED_LOCK;
 700		numLock = 1;
 701	} else if (pfLock->fl_type == F_EXLCK) {
 702		cFYI(1, "F_EXLCK");
 703		numLock = 1;
 704	} else if (pfLock->fl_type == F_SHLCK) {
 
 705		cFYI(1, "F_SHLCK");
 706		lockType |= LOCKING_ANDX_SHARED_LOCK;
 707		numLock = 1;
 708	} else
 709		cFYI(1, "Unknown type of lock");
 
 710
 711	cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
 712	tcon = tlink_tcon(((struct cifsFileInfo *)file->private_data)->tlink);
 713	netfid = ((struct cifsFileInfo *)file->private_data)->netfid;
 
 
 
 
 
 714
 715	if ((tcon->ses->capabilities & CAP_UNIX) &&
 716	    (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
 717	    ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
 718		posix_locking = 1;
 719	/* BB add code here to normalize offset and length to
 720	account for negative length which we can not accept over the
 721	wire */
 722	if (IS_GETLK(cmd)) {
 723		if (posix_locking) {
 724			int posix_lock_type;
 725			if (lockType & LOCKING_ANDX_SHARED_LOCK)
 726				posix_lock_type = CIFS_RDLCK;
 727			else
 728				posix_lock_type = CIFS_WRLCK;
 729			rc = CIFSSMBPosixLock(xid, tcon, netfid, 1 /* get */,
 730					length, pfLock, posix_lock_type,
 731					wait_flag);
 732			FreeXid(xid);
 733			return rc;
 734		}
 735
 736		/* BB we could chain these into one lock request BB */
 737		rc = CIFSSMBLock(xid, tcon, netfid, length, pfLock->fl_start,
 738				 0, 1, lockType, 0 /* wait flag */, 0);
 739		if (rc == 0) {
 740			rc = CIFSSMBLock(xid, tcon, netfid, length,
 741					 pfLock->fl_start, 1 /* numUnlock */ ,
 742					 0 /* numLock */ , lockType,
 743					 0 /* wait flag */, 0);
 744			pfLock->fl_type = F_UNLCK;
 745			if (rc != 0)
 746				cERROR(1, "Error unlocking previously locked "
 747					   "range %d during test of lock", rc);
 748			rc = 0;
 749
 750		} else {
 751			/* if rc == ERR_SHARING_VIOLATION ? */
 752			rc = 0;
 753
 754			if (lockType & LOCKING_ANDX_SHARED_LOCK) {
 755				pfLock->fl_type = F_WRLCK;
 756			} else {
 757				rc = CIFSSMBLock(xid, tcon, netfid, length,
 758					pfLock->fl_start, 0, 1,
 759					lockType | LOCKING_ANDX_SHARED_LOCK,
 760					0 /* wait flag */, 0);
 761				if (rc == 0) {
 762					rc = CIFSSMBLock(xid, tcon, netfid,
 763						length, pfLock->fl_start, 1, 0,
 764						lockType |
 765						LOCKING_ANDX_SHARED_LOCK,
 766						0 /* wait flag */, 0);
 767					pfLock->fl_type = F_RDLCK;
 768					if (rc != 0)
 769						cERROR(1, "Error unlocking "
 770						"previously locked range %d "
 771						"during test of lock", rc);
 772					rc = 0;
 773				} else {
 774					pfLock->fl_type = F_WRLCK;
 775					rc = 0;
 776				}
 777			}
 778		}
 779
 780		FreeXid(xid);
 
 781		return rc;
 
 
 
 
 
 
 
 
 
 
 
 
 782	}
 783
 784	if (!numLock && !numUnlock) {
 785		/* if no lock or unlock then nothing
 786		to do since we do not know what it is */
 787		FreeXid(xid);
 788		return -EOPNOTSUPP;
 789	}
 790
 791	if (posix_locking) {
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 792		int posix_lock_type;
 793		if (lockType & LOCKING_ANDX_SHARED_LOCK)
 
 
 
 
 
 794			posix_lock_type = CIFS_RDLCK;
 795		else
 796			posix_lock_type = CIFS_WRLCK;
 797
 798		if (numUnlock == 1)
 799			posix_lock_type = CIFS_UNLCK;
 800
 801		rc = CIFSSMBPosixLock(xid, tcon, netfid, 0 /* set */,
 802				      length, pfLock, posix_lock_type,
 803				      wait_flag);
 804	} else {
 805		struct cifsFileInfo *fid = file->private_data;
 806
 807		if (numLock) {
 808			rc = CIFSSMBLock(xid, tcon, netfid, length,
 809					 pfLock->fl_start, 0, numLock, lockType,
 810					 wait_flag, 0);
 811
 812			if (rc == 0) {
 813				/* For Windows locks we must store them. */
 814				rc = store_file_lock(fid, length,
 815						pfLock->fl_start, lockType);
 816			}
 817		} else if (numUnlock) {
 818			/* For each stored lock that this unlock overlaps
 819			   completely, unlock it. */
 820			int stored_rc = 0;
 821			struct cifsLockInfo *li, *tmp;
 822
 823			rc = 0;
 824			mutex_lock(&fid->lock_mutex);
 825			list_for_each_entry_safe(li, tmp, &fid->llist, llist) {
 826				if (pfLock->fl_start <= li->offset &&
 827						(pfLock->fl_start + length) >=
 828						(li->offset + li->length)) {
 829					stored_rc = CIFSSMBLock(xid, tcon,
 830							netfid, li->length,
 831							li->offset, 1, 0,
 832							li->type, false, 0);
 833					if (stored_rc)
 834						rc = stored_rc;
 835					else {
 836						list_del(&li->llist);
 837						kfree(li);
 838					}
 839				}
 840			}
 841			mutex_unlock(&fid->lock_mutex);
 842		}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 843	}
 844
 845	if (pfLock->fl_flags & FL_POSIX)
 846		posix_lock_file_wait(file, pfLock);
 847	FreeXid(xid);
 848	return rc;
 849}
 850
 851/* update the file size (if needed) after a write */
 
 
 
 852void
 853cifs_update_eof(struct cifsInodeInfo *cifsi, loff_t offset,
 854		      unsigned int bytes_written)
 855{
 856	loff_t end_of_write = offset + bytes_written;
 857
 858	if (end_of_write > cifsi->server_eof)
 859		cifsi->server_eof = end_of_write;
 860}
 861
 862static ssize_t cifs_write(struct cifsFileInfo *open_file, __u32 pid,
 863			  const char *write_data, size_t write_size,
 864			  loff_t *poffset)
 865{
 866	int rc = 0;
 867	unsigned int bytes_written = 0;
 868	unsigned int total_written;
 869	struct cifs_sb_info *cifs_sb;
 870	struct cifs_tcon *pTcon;
 871	int xid;
 872	struct dentry *dentry = open_file->dentry;
 873	struct cifsInodeInfo *cifsi = CIFS_I(dentry->d_inode);
 874	struct cifs_io_parms io_parms;
 875
 876	cifs_sb = CIFS_SB(dentry->d_sb);
 877
 878	cFYI(1, "write %zd bytes to offset %lld of %s", write_size,
 879	   *poffset, dentry->d_name.name);
 880
 881	pTcon = tlink_tcon(open_file->tlink);
 882
 883	xid = GetXid();
 884
 885	for (total_written = 0; write_size > total_written;
 886	     total_written += bytes_written) {
 887		rc = -EAGAIN;
 888		while (rc == -EAGAIN) {
 889			struct kvec iov[2];
 890			unsigned int len;
 891
 892			if (open_file->invalidHandle) {
 893				/* we could deadlock if we called
 894				   filemap_fdatawait from here so tell
 895				   reopen_file not to flush data to
 896				   server now */
 897				rc = cifs_reopen_file(open_file, false);
 898				if (rc != 0)
 899					break;
 900			}
 901
 902			len = min((size_t)cifs_sb->wsize,
 903				  write_size - total_written);
 904			/* iov[0] is reserved for smb header */
 905			iov[1].iov_base = (char *)write_data + total_written;
 906			iov[1].iov_len = len;
 907			io_parms.netfid = open_file->netfid;
 908			io_parms.pid = pid;
 909			io_parms.tcon = pTcon;
 910			io_parms.offset = *poffset;
 911			io_parms.length = len;
 912			rc = CIFSSMBWrite2(xid, &io_parms, &bytes_written, iov,
 913					   1, 0);
 914		}
 915		if (rc || (bytes_written == 0)) {
 916			if (total_written)
 917				break;
 918			else {
 919				FreeXid(xid);
 920				return rc;
 921			}
 922		} else {
 
 923			cifs_update_eof(cifsi, *poffset, bytes_written);
 
 924			*poffset += bytes_written;
 925		}
 926	}
 927
 928	cifs_stats_bytes_written(pTcon, total_written);
 929
 930	if (total_written > 0) {
 931		spin_lock(&dentry->d_inode->i_lock);
 932		if (*poffset > dentry->d_inode->i_size)
 933			i_size_write(dentry->d_inode, *poffset);
 934		spin_unlock(&dentry->d_inode->i_lock);
 935	}
 936	mark_inode_dirty_sync(dentry->d_inode);
 937	FreeXid(xid);
 938	return total_written;
 939}
 940
 941struct cifsFileInfo *find_readable_file(struct cifsInodeInfo *cifs_inode,
 942					bool fsuid_only)
 943{
 944	struct cifsFileInfo *open_file = NULL;
 945	struct cifs_sb_info *cifs_sb = CIFS_SB(cifs_inode->vfs_inode.i_sb);
 946
 947	/* only filter by fsuid on multiuser mounts */
 948	if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
 949		fsuid_only = false;
 950
 951	spin_lock(&cifs_file_list_lock);
 952	/* we could simply get the first_list_entry since write-only entries
 953	   are always at the end of the list but since the first entry might
 954	   have a close pending, we go through the whole list */
 955	list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
 956		if (fsuid_only && open_file->uid != current_fsuid())
 957			continue;
 958		if (OPEN_FMODE(open_file->f_flags) & FMODE_READ) {
 959			if (!open_file->invalidHandle) {
 960				/* found a good file */
 961				/* lock it so it will not be closed on us */
 962				cifsFileInfo_get(open_file);
 963				spin_unlock(&cifs_file_list_lock);
 964				return open_file;
 965			} /* else might as well continue, and look for
 966			     another, or simply have the caller reopen it
 967			     again rather than trying to fix this handle */
 968		} else /* write only file */
 969			break; /* write only files are last so must be done */
 970	}
 971	spin_unlock(&cifs_file_list_lock);
 972	return NULL;
 973}
 974
 975struct cifsFileInfo *find_writable_file(struct cifsInodeInfo *cifs_inode,
 976					bool fsuid_only)
 977{
 978	struct cifsFileInfo *open_file;
 979	struct cifs_sb_info *cifs_sb;
 980	bool any_available = false;
 981	int rc;
 
 982
 983	/* Having a null inode here (because mapping->host was set to zero by
 984	the VFS or MM) should not happen but we had reports of on oops (due to
 985	it being zero) during stress testcases so we need to check for it */
 986
 987	if (cifs_inode == NULL) {
 988		cERROR(1, "Null inode passed to cifs_writeable_file");
 989		dump_stack();
 990		return NULL;
 991	}
 992
 993	cifs_sb = CIFS_SB(cifs_inode->vfs_inode.i_sb);
 994
 995	/* only filter by fsuid on multiuser mounts */
 996	if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
 997		fsuid_only = false;
 998
 999	spin_lock(&cifs_file_list_lock);
1000refind_writable:
 
 
 
 
1001	list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
1002		if (!any_available && open_file->pid != current->tgid)
1003			continue;
1004		if (fsuid_only && open_file->uid != current_fsuid())
1005			continue;
1006		if (OPEN_FMODE(open_file->f_flags) & FMODE_WRITE) {
1007			cifsFileInfo_get(open_file);
1008
1009			if (!open_file->invalidHandle) {
1010				/* found a good writable file */
 
1011				spin_unlock(&cifs_file_list_lock);
1012				return open_file;
 
 
 
1013			}
1014
1015			spin_unlock(&cifs_file_list_lock);
1016
1017			/* Had to unlock since following call can block */
1018			rc = cifs_reopen_file(open_file, false);
1019			if (!rc)
1020				return open_file;
1021
1022			/* if it fails, try another handle if possible */
1023			cFYI(1, "wp failed on reopen file");
1024			cifsFileInfo_put(open_file);
1025
1026			spin_lock(&cifs_file_list_lock);
1027
1028			/* else we simply continue to the next entry. Thus
1029			   we do not loop on reopen errors.  If we
1030			   can not reopen the file, for example if we
1031			   reconnected to a server with another client
1032			   racing to delete or lock the file we would not
1033			   make progress if we restarted before the beginning
1034			   of the loop here. */
1035		}
1036	}
1037	/* couldn't find useable FH with same pid, try any available */
1038	if (!any_available) {
1039		any_available = true;
1040		goto refind_writable;
1041	}
 
 
 
 
 
 
1042	spin_unlock(&cifs_file_list_lock);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1043	return NULL;
1044}
1045
1046static int cifs_partialpagewrite(struct page *page, unsigned from, unsigned to)
1047{
1048	struct address_space *mapping = page->mapping;
1049	loff_t offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
1050	char *write_data;
1051	int rc = -EFAULT;
1052	int bytes_written = 0;
1053	struct inode *inode;
1054	struct cifsFileInfo *open_file;
1055
1056	if (!mapping || !mapping->host)
1057		return -EFAULT;
1058
1059	inode = page->mapping->host;
1060
1061	offset += (loff_t)from;
1062	write_data = kmap(page);
1063	write_data += from;
1064
1065	if ((to > PAGE_CACHE_SIZE) || (from > to)) {
1066		kunmap(page);
1067		return -EIO;
1068	}
1069
1070	/* racing with truncate? */
1071	if (offset > mapping->host->i_size) {
1072		kunmap(page);
1073		return 0; /* don't care */
1074	}
1075
1076	/* check to make sure that we are not extending the file */
1077	if (mapping->host->i_size - offset < (loff_t)to)
1078		to = (unsigned)(mapping->host->i_size - offset);
1079
1080	open_file = find_writable_file(CIFS_I(mapping->host), false);
1081	if (open_file) {
1082		bytes_written = cifs_write(open_file, open_file->pid,
1083					   write_data, to - from, &offset);
1084		cifsFileInfo_put(open_file);
1085		/* Does mm or vfs already set times? */
1086		inode->i_atime = inode->i_mtime = current_fs_time(inode->i_sb);
1087		if ((bytes_written > 0) && (offset))
1088			rc = 0;
1089		else if (bytes_written < 0)
1090			rc = bytes_written;
1091	} else {
1092		cFYI(1, "No writeable filehandles for inode");
1093		rc = -EIO;
1094	}
1095
1096	kunmap(page);
1097	return rc;
1098}
1099
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1100static int cifs_writepages(struct address_space *mapping,
1101			   struct writeback_control *wbc)
1102{
1103	struct cifs_sb_info *cifs_sb = CIFS_SB(mapping->host->i_sb);
1104	bool done = false, scanned = false, range_whole = false;
1105	pgoff_t end, index;
1106	struct cifs_writedata *wdata;
1107	struct page *page;
1108	int rc = 0;
1109
1110	/*
1111	 * If wsize is smaller than the page cache size, default to writing
1112	 * one page at a time via cifs_writepage
1113	 */
1114	if (cifs_sb->wsize < PAGE_CACHE_SIZE)
1115		return generic_writepages(mapping, wbc);
1116
1117	if (wbc->range_cyclic) {
1118		index = mapping->writeback_index; /* Start from prev offset */
1119		end = -1;
1120	} else {
1121		index = wbc->range_start >> PAGE_CACHE_SHIFT;
1122		end = wbc->range_end >> PAGE_CACHE_SHIFT;
1123		if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
1124			range_whole = true;
1125		scanned = true;
1126	}
1127retry:
1128	while (!done && index <= end) {
1129		unsigned int i, nr_pages, found_pages;
1130		pgoff_t next = 0, tofind;
1131		struct page **pages;
1132
1133		tofind = min((cifs_sb->wsize / PAGE_CACHE_SIZE) - 1,
1134				end - index) + 1;
1135
1136		wdata = cifs_writedata_alloc((unsigned int)tofind);
 
1137		if (!wdata) {
1138			rc = -ENOMEM;
1139			break;
1140		}
1141
1142		/*
1143		 * find_get_pages_tag seems to return a max of 256 on each
1144		 * iteration, so we must call it several times in order to
1145		 * fill the array or the wsize is effectively limited to
1146		 * 256 * PAGE_CACHE_SIZE.
1147		 */
1148		found_pages = 0;
1149		pages = wdata->pages;
1150		do {
1151			nr_pages = find_get_pages_tag(mapping, &index,
1152							PAGECACHE_TAG_DIRTY,
1153							tofind, pages);
1154			found_pages += nr_pages;
1155			tofind -= nr_pages;
1156			pages += nr_pages;
1157		} while (nr_pages && tofind && index <= end);
1158
1159		if (found_pages == 0) {
1160			kref_put(&wdata->refcount, cifs_writedata_release);
1161			break;
1162		}
1163
1164		nr_pages = 0;
1165		for (i = 0; i < found_pages; i++) {
1166			page = wdata->pages[i];
1167			/*
1168			 * At this point we hold neither mapping->tree_lock nor
1169			 * lock on the page itself: the page may be truncated or
1170			 * invalidated (changing page->mapping to NULL), or even
1171			 * swizzled back from swapper_space to tmpfs file
1172			 * mapping
1173			 */
1174
1175			if (nr_pages == 0)
1176				lock_page(page);
1177			else if (!trylock_page(page))
1178				break;
1179
1180			if (unlikely(page->mapping != mapping)) {
1181				unlock_page(page);
1182				break;
1183			}
1184
1185			if (!wbc->range_cyclic && page->index > end) {
1186				done = true;
1187				unlock_page(page);
1188				break;
1189			}
1190
1191			if (next && (page->index != next)) {
1192				/* Not next consecutive page */
1193				unlock_page(page);
1194				break;
1195			}
1196
1197			if (wbc->sync_mode != WB_SYNC_NONE)
1198				wait_on_page_writeback(page);
1199
1200			if (PageWriteback(page) ||
1201					!clear_page_dirty_for_io(page)) {
1202				unlock_page(page);
1203				break;
1204			}
1205
1206			/*
1207			 * This actually clears the dirty bit in the radix tree.
1208			 * See cifs_writepage() for more commentary.
1209			 */
1210			set_page_writeback(page);
1211
1212			if (page_offset(page) >= mapping->host->i_size) {
1213				done = true;
1214				unlock_page(page);
1215				end_page_writeback(page);
1216				break;
1217			}
1218
1219			wdata->pages[i] = page;
1220			next = page->index + 1;
1221			++nr_pages;
1222		}
1223
1224		/* reset index to refind any pages skipped */
1225		if (nr_pages == 0)
1226			index = wdata->pages[0]->index + 1;
1227
1228		/* put any pages we aren't going to use */
1229		for (i = nr_pages; i < found_pages; i++) {
1230			page_cache_release(wdata->pages[i]);
1231			wdata->pages[i] = NULL;
1232		}
1233
1234		/* nothing to write? */
1235		if (nr_pages == 0) {
1236			kref_put(&wdata->refcount, cifs_writedata_release);
1237			continue;
1238		}
1239
1240		wdata->sync_mode = wbc->sync_mode;
1241		wdata->nr_pages = nr_pages;
1242		wdata->offset = page_offset(wdata->pages[0]);
 
1243
1244		do {
1245			if (wdata->cfile != NULL)
1246				cifsFileInfo_put(wdata->cfile);
1247			wdata->cfile = find_writable_file(CIFS_I(mapping->host),
1248							  false);
1249			if (!wdata->cfile) {
1250				cERROR(1, "No writable handles for inode");
1251				rc = -EBADF;
1252				break;
1253			}
 
1254			rc = cifs_async_writev(wdata);
1255		} while (wbc->sync_mode == WB_SYNC_ALL && rc == -EAGAIN);
1256
1257		for (i = 0; i < nr_pages; ++i)
1258			unlock_page(wdata->pages[i]);
1259
1260		/* send failure -- clean up the mess */
1261		if (rc != 0) {
1262			for (i = 0; i < nr_pages; ++i) {
1263				if (rc == -EAGAIN)
1264					redirty_page_for_writepage(wbc,
1265							   wdata->pages[i]);
1266				else
1267					SetPageError(wdata->pages[i]);
1268				end_page_writeback(wdata->pages[i]);
1269				page_cache_release(wdata->pages[i]);
1270			}
1271			if (rc != -EAGAIN)
1272				mapping_set_error(mapping, rc);
1273		}
1274		kref_put(&wdata->refcount, cifs_writedata_release);
1275
1276		wbc->nr_to_write -= nr_pages;
1277		if (wbc->nr_to_write <= 0)
1278			done = true;
1279
1280		index = next;
1281	}
1282
1283	if (!scanned && !done) {
1284		/*
1285		 * We hit the last page and there is more work to be done: wrap
1286		 * back to the start of the file
1287		 */
1288		scanned = true;
1289		index = 0;
1290		goto retry;
1291	}
1292
1293	if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
1294		mapping->writeback_index = index;
1295
1296	return rc;
1297}
1298
1299static int
1300cifs_writepage_locked(struct page *page, struct writeback_control *wbc)
1301{
1302	int rc;
1303	int xid;
1304
1305	xid = GetXid();
1306/* BB add check for wbc flags */
1307	page_cache_get(page);
1308	if (!PageUptodate(page))
1309		cFYI(1, "ppw - page not up to date");
1310
1311	/*
1312	 * Set the "writeback" flag, and clear "dirty" in the radix tree.
1313	 *
1314	 * A writepage() implementation always needs to do either this,
1315	 * or re-dirty the page with "redirty_page_for_writepage()" in
1316	 * the case of a failure.
1317	 *
1318	 * Just unlocking the page will cause the radix tree tag-bits
1319	 * to fail to update with the state of the page correctly.
1320	 */
1321	set_page_writeback(page);
1322retry_write:
1323	rc = cifs_partialpagewrite(page, 0, PAGE_CACHE_SIZE);
1324	if (rc == -EAGAIN && wbc->sync_mode == WB_SYNC_ALL)
1325		goto retry_write;
1326	else if (rc == -EAGAIN)
1327		redirty_page_for_writepage(wbc, page);
1328	else if (rc != 0)
1329		SetPageError(page);
1330	else
1331		SetPageUptodate(page);
1332	end_page_writeback(page);
1333	page_cache_release(page);
1334	FreeXid(xid);
1335	return rc;
1336}
1337
1338static int cifs_writepage(struct page *page, struct writeback_control *wbc)
1339{
1340	int rc = cifs_writepage_locked(page, wbc);
1341	unlock_page(page);
1342	return rc;
1343}
1344
1345static int cifs_write_end(struct file *file, struct address_space *mapping,
1346			loff_t pos, unsigned len, unsigned copied,
1347			struct page *page, void *fsdata)
1348{
1349	int rc;
1350	struct inode *inode = mapping->host;
1351	struct cifsFileInfo *cfile = file->private_data;
1352	struct cifs_sb_info *cifs_sb = CIFS_SB(cfile->dentry->d_sb);
1353	__u32 pid;
1354
1355	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
1356		pid = cfile->pid;
1357	else
1358		pid = current->tgid;
1359
1360	cFYI(1, "write_end for page %p from pos %lld with %d bytes",
1361		 page, pos, copied);
1362
1363	if (PageChecked(page)) {
1364		if (copied == len)
1365			SetPageUptodate(page);
1366		ClearPageChecked(page);
1367	} else if (!PageUptodate(page) && copied == PAGE_CACHE_SIZE)
1368		SetPageUptodate(page);
1369
1370	if (!PageUptodate(page)) {
1371		char *page_data;
1372		unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
1373		int xid;
1374
1375		xid = GetXid();
1376		/* this is probably better than directly calling
1377		   partialpage_write since in this function the file handle is
1378		   known which we might as well	leverage */
1379		/* BB check if anything else missing out of ppw
1380		   such as updating last write time */
1381		page_data = kmap(page);
1382		rc = cifs_write(cfile, pid, page_data + offset, copied, &pos);
1383		/* if (rc < 0) should we set writebehind rc? */
1384		kunmap(page);
1385
1386		FreeXid(xid);
1387	} else {
1388		rc = copied;
1389		pos += copied;
1390		set_page_dirty(page);
1391	}
1392
1393	if (rc > 0) {
1394		spin_lock(&inode->i_lock);
1395		if (pos > inode->i_size)
1396			i_size_write(inode, pos);
1397		spin_unlock(&inode->i_lock);
1398	}
1399
1400	unlock_page(page);
1401	page_cache_release(page);
1402
1403	return rc;
1404}
1405
1406int cifs_strict_fsync(struct file *file, loff_t start, loff_t end,
1407		      int datasync)
1408{
1409	int xid;
1410	int rc = 0;
1411	struct cifs_tcon *tcon;
1412	struct cifsFileInfo *smbfile = file->private_data;
1413	struct inode *inode = file->f_path.dentry->d_inode;
1414	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
1415
1416	rc = filemap_write_and_wait_range(inode->i_mapping, start, end);
1417	if (rc)
1418		return rc;
1419	mutex_lock(&inode->i_mutex);
1420
1421	xid = GetXid();
1422
1423	cFYI(1, "Sync file - name: %s datasync: 0x%x",
1424		file->f_path.dentry->d_name.name, datasync);
1425
1426	if (!CIFS_I(inode)->clientCanCacheRead) {
1427		rc = cifs_invalidate_mapping(inode);
1428		if (rc) {
1429			cFYI(1, "rc: %d during invalidate phase", rc);
1430			rc = 0; /* don't care about it in fsync */
1431		}
1432	}
1433
1434	tcon = tlink_tcon(smbfile->tlink);
1435	if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC))
1436		rc = CIFSSMBFlush(xid, tcon, smbfile->netfid);
1437
1438	FreeXid(xid);
1439	mutex_unlock(&inode->i_mutex);
1440	return rc;
1441}
1442
1443int cifs_fsync(struct file *file, loff_t start, loff_t end, int datasync)
1444{
1445	int xid;
1446	int rc = 0;
1447	struct cifs_tcon *tcon;
1448	struct cifsFileInfo *smbfile = file->private_data;
1449	struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
1450	struct inode *inode = file->f_mapping->host;
1451
1452	rc = filemap_write_and_wait_range(inode->i_mapping, start, end);
1453	if (rc)
1454		return rc;
1455	mutex_lock(&inode->i_mutex);
1456
1457	xid = GetXid();
1458
1459	cFYI(1, "Sync file - name: %s datasync: 0x%x",
1460		file->f_path.dentry->d_name.name, datasync);
1461
1462	tcon = tlink_tcon(smbfile->tlink);
1463	if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC))
1464		rc = CIFSSMBFlush(xid, tcon, smbfile->netfid);
1465
1466	FreeXid(xid);
1467	mutex_unlock(&inode->i_mutex);
1468	return rc;
1469}
1470
1471/*
1472 * As file closes, flush all cached write data for this inode checking
1473 * for write behind errors.
1474 */
1475int cifs_flush(struct file *file, fl_owner_t id)
1476{
1477	struct inode *inode = file->f_path.dentry->d_inode;
1478	int rc = 0;
1479
1480	if (file->f_mode & FMODE_WRITE)
1481		rc = filemap_write_and_wait(inode->i_mapping);
1482
1483	cFYI(1, "Flush inode %p file %p rc %d", inode, file, rc);
1484
1485	return rc;
1486}
1487
1488static int
1489cifs_write_allocate_pages(struct page **pages, unsigned long num_pages)
1490{
1491	int rc = 0;
1492	unsigned long i;
1493
1494	for (i = 0; i < num_pages; i++) {
1495		pages[i] = alloc_page(__GFP_HIGHMEM);
1496		if (!pages[i]) {
1497			/*
1498			 * save number of pages we have already allocated and
1499			 * return with ENOMEM error
1500			 */
1501			num_pages = i;
1502			rc = -ENOMEM;
1503			goto error;
1504		}
1505	}
1506
1507	return rc;
1508
1509error:
1510	for (i = 0; i < num_pages; i++)
1511		put_page(pages[i]);
1512	return rc;
1513}
1514
1515static inline
1516size_t get_numpages(const size_t wsize, const size_t len, size_t *cur_len)
1517{
1518	size_t num_pages;
1519	size_t clen;
1520
1521	clen = min_t(const size_t, len, wsize);
1522	num_pages = clen / PAGE_CACHE_SIZE;
1523	if (clen % PAGE_CACHE_SIZE)
1524		num_pages++;
1525
1526	if (cur_len)
1527		*cur_len = clen;
1528
1529	return num_pages;
1530}
1531
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1532static ssize_t
1533cifs_iovec_write(struct file *file, const struct iovec *iov,
1534		 unsigned long nr_segs, loff_t *poffset)
1535{
1536	unsigned int written;
1537	unsigned long num_pages, npages, i;
1538	size_t copied, len, cur_len;
1539	ssize_t total_written = 0;
1540	struct kvec *to_send;
1541	struct page **pages;
1542	struct iov_iter it;
1543	struct inode *inode;
1544	struct cifsFileInfo *open_file;
1545	struct cifs_tcon *pTcon;
1546	struct cifs_sb_info *cifs_sb;
1547	struct cifs_io_parms io_parms;
1548	int xid, rc;
1549	__u32 pid;
 
1550
1551	len = iov_length(iov, nr_segs);
1552	if (!len)
1553		return 0;
1554
1555	rc = generic_write_checks(file, poffset, &len, 0);
1556	if (rc)
1557		return rc;
1558
 
1559	cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
1560	num_pages = get_numpages(cifs_sb->wsize, len, &cur_len);
1561
1562	pages = kmalloc(sizeof(struct pages *)*num_pages, GFP_KERNEL);
1563	if (!pages)
1564		return -ENOMEM;
1565
1566	to_send = kmalloc(sizeof(struct kvec)*(num_pages + 1), GFP_KERNEL);
1567	if (!to_send) {
1568		kfree(pages);
1569		return -ENOMEM;
1570	}
1571
1572	rc = cifs_write_allocate_pages(pages, num_pages);
1573	if (rc) {
1574		kfree(pages);
1575		kfree(to_send);
1576		return rc;
1577	}
1578
1579	xid = GetXid();
1580	open_file = file->private_data;
 
 
1581
1582	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
1583		pid = open_file->pid;
1584	else
1585		pid = current->tgid;
1586
1587	pTcon = tlink_tcon(open_file->tlink);
1588	inode = file->f_path.dentry->d_inode;
1589
1590	iov_iter_init(&it, iov, nr_segs, len, 0);
1591	npages = num_pages;
1592
1593	do {
1594		size_t save_len = cur_len;
1595		for (i = 0; i < npages; i++) {
1596			copied = min_t(const size_t, cur_len, PAGE_CACHE_SIZE);
1597			copied = iov_iter_copy_from_user(pages[i], &it, 0,
1598							 copied);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1599			cur_len -= copied;
1600			iov_iter_advance(&it, copied);
1601			to_send[i+1].iov_base = kmap(pages[i]);
1602			to_send[i+1].iov_len = copied;
1603		}
1604
1605		cur_len = save_len - cur_len;
1606
1607		do {
1608			if (open_file->invalidHandle) {
1609				rc = cifs_reopen_file(open_file, false);
1610				if (rc != 0)
1611					break;
1612			}
1613			io_parms.netfid = open_file->netfid;
1614			io_parms.pid = pid;
1615			io_parms.tcon = pTcon;
1616			io_parms.offset = *poffset;
1617			io_parms.length = cur_len;
1618			rc = CIFSSMBWrite2(xid, &io_parms, &written, to_send,
1619					   npages, 0);
1620		} while (rc == -EAGAIN);
1621
1622		for (i = 0; i < npages; i++)
1623			kunmap(pages[i]);
1624
1625		if (written) {
1626			len -= written;
1627			total_written += written;
1628			cifs_update_eof(CIFS_I(inode), *poffset, written);
1629			*poffset += written;
1630		} else if (rc < 0) {
1631			if (!total_written)
1632				total_written = rc;
1633			break;
1634		}
1635
1636		/* get length and number of kvecs of the next write */
1637		npages = get_numpages(cifs_sb->wsize, len, &cur_len);
 
1638	} while (len > 0);
1639
1640	if (total_written > 0) {
1641		spin_lock(&inode->i_lock);
1642		if (*poffset > inode->i_size)
1643			i_size_write(inode, *poffset);
1644		spin_unlock(&inode->i_lock);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1645	}
1646
1647	cifs_stats_bytes_written(pTcon, total_written);
1648	mark_inode_dirty_sync(inode);
1649
1650	for (i = 0; i < num_pages; i++)
1651		put_page(pages[i]);
1652	kfree(to_send);
1653	kfree(pages);
1654	FreeXid(xid);
1655	return total_written;
1656}
1657
1658ssize_t cifs_user_writev(struct kiocb *iocb, const struct iovec *iov,
1659				unsigned long nr_segs, loff_t pos)
1660{
1661	ssize_t written;
1662	struct inode *inode;
1663
1664	inode = iocb->ki_filp->f_path.dentry->d_inode;
1665
1666	/*
1667	 * BB - optimize the way when signing is disabled. We can drop this
1668	 * extra memory-to-memory copying and use iovec buffers for constructing
1669	 * write request.
1670	 */
1671
1672	written = cifs_iovec_write(iocb->ki_filp, iov, nr_segs, &pos);
1673	if (written > 0) {
1674		CIFS_I(inode)->invalid_mapping = true;
1675		iocb->ki_pos = pos;
1676	}
1677
1678	return written;
1679}
1680
1681ssize_t cifs_strict_writev(struct kiocb *iocb, const struct iovec *iov,
1682			   unsigned long nr_segs, loff_t pos)
1683{
1684	struct inode *inode;
1685
1686	inode = iocb->ki_filp->f_path.dentry->d_inode;
1687
1688	if (CIFS_I(inode)->clientCanCacheAll)
1689		return generic_file_aio_write(iocb, iov, nr_segs, pos);
1690
1691	/*
1692	 * In strict cache mode we need to write the data to the server exactly
1693	 * from the pos to pos+len-1 rather than flush all affected pages
1694	 * because it may cause a error with mandatory locks on these pages but
1695	 * not on the region from pos to ppos+len-1.
1696	 */
1697
1698	return cifs_user_writev(iocb, iov, nr_segs, pos);
1699}
1700
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1701static ssize_t
1702cifs_iovec_read(struct file *file, const struct iovec *iov,
1703		 unsigned long nr_segs, loff_t *poffset)
1704{
1705	int rc;
1706	int xid;
1707	ssize_t total_read;
1708	unsigned int bytes_read = 0;
1709	size_t len, cur_len;
1710	int iov_offset = 0;
 
 
1711	struct cifs_sb_info *cifs_sb;
1712	struct cifs_tcon *pTcon;
1713	struct cifsFileInfo *open_file;
1714	struct smb_com_read_rsp *pSMBr;
1715	struct cifs_io_parms io_parms;
1716	char *read_data;
1717	__u32 pid;
1718
1719	if (!nr_segs)
1720		return 0;
1721
1722	len = iov_length(iov, nr_segs);
1723	if (!len)
1724		return 0;
1725
1726	xid = GetXid();
1727	cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
1728
1729	open_file = file->private_data;
1730	pTcon = tlink_tcon(open_file->tlink);
1731
1732	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
1733		pid = open_file->pid;
1734	else
1735		pid = current->tgid;
1736
1737	if ((file->f_flags & O_ACCMODE) == O_WRONLY)
1738		cFYI(1, "attempting read on write only file instance");
1739
1740	for (total_read = 0; total_read < len; total_read += bytes_read) {
1741		cur_len = min_t(const size_t, len - total_read, cifs_sb->rsize);
1742		rc = -EAGAIN;
1743		read_data = NULL;
1744
1745		while (rc == -EAGAIN) {
1746			int buf_type = CIFS_NO_BUFFER;
1747			if (open_file->invalidHandle) {
1748				rc = cifs_reopen_file(open_file, true);
1749				if (rc != 0)
1750					break;
1751			}
1752			io_parms.netfid = open_file->netfid;
1753			io_parms.pid = pid;
1754			io_parms.tcon = pTcon;
1755			io_parms.offset = *poffset;
1756			io_parms.length = cur_len;
1757			rc = CIFSSMBRead(xid, &io_parms, &bytes_read,
1758					 &read_data, &buf_type);
1759			pSMBr = (struct smb_com_read_rsp *)read_data;
1760			if (read_data) {
1761				char *data_offset = read_data + 4 +
1762						le16_to_cpu(pSMBr->DataOffset);
1763				if (memcpy_toiovecend(iov, data_offset,
1764						      iov_offset, bytes_read))
1765					rc = -EFAULT;
1766				if (buf_type == CIFS_SMALL_BUFFER)
1767					cifs_small_buf_release(read_data);
1768				else if (buf_type == CIFS_LARGE_BUFFER)
1769					cifs_buf_release(read_data);
1770				read_data = NULL;
1771				iov_offset += bytes_read;
1772			}
1773		}
1774
1775		if (rc || (bytes_read == 0)) {
1776			if (total_read) {
1777				break;
1778			} else {
1779				FreeXid(xid);
1780				return rc;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1781			}
1782		} else {
1783			cifs_stats_bytes_read(pTcon, bytes_read);
1784			*poffset += bytes_read;
1785		}
 
 
1786	}
1787
1788	FreeXid(xid);
1789	return total_read;
 
 
1790}
1791
1792ssize_t cifs_user_readv(struct kiocb *iocb, const struct iovec *iov,
1793			       unsigned long nr_segs, loff_t pos)
1794{
1795	ssize_t read;
1796
1797	read = cifs_iovec_read(iocb->ki_filp, iov, nr_segs, &pos);
1798	if (read > 0)
1799		iocb->ki_pos = pos;
1800
1801	return read;
1802}
1803
1804ssize_t cifs_strict_readv(struct kiocb *iocb, const struct iovec *iov,
1805			  unsigned long nr_segs, loff_t pos)
1806{
1807	struct inode *inode;
1808
1809	inode = iocb->ki_filp->f_path.dentry->d_inode;
1810
1811	if (CIFS_I(inode)->clientCanCacheRead)
1812		return generic_file_aio_read(iocb, iov, nr_segs, pos);
1813
1814	/*
1815	 * In strict cache mode we need to read from the server all the time
1816	 * if we don't have level II oplock because the server can delay mtime
1817	 * change - so we can't make a decision about inode invalidating.
1818	 * And we can also fail with pagereading if there are mandatory locks
1819	 * on pages affected by this read but not on the region from pos to
1820	 * pos+len-1.
1821	 */
1822
1823	return cifs_user_readv(iocb, iov, nr_segs, pos);
1824}
1825
1826static ssize_t cifs_read(struct file *file, char *read_data, size_t read_size,
1827			 loff_t *poffset)
1828{
1829	int rc = -EACCES;
1830	unsigned int bytes_read = 0;
1831	unsigned int total_read;
1832	unsigned int current_read_size;
 
1833	struct cifs_sb_info *cifs_sb;
1834	struct cifs_tcon *pTcon;
1835	int xid;
1836	char *current_offset;
1837	struct cifsFileInfo *open_file;
1838	struct cifs_io_parms io_parms;
1839	int buf_type = CIFS_NO_BUFFER;
1840	__u32 pid;
1841
1842	xid = GetXid();
1843	cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
1844
 
 
 
1845	if (file->private_data == NULL) {
1846		rc = -EBADF;
1847		FreeXid(xid);
1848		return rc;
1849	}
1850	open_file = file->private_data;
1851	pTcon = tlink_tcon(open_file->tlink);
1852
1853	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
1854		pid = open_file->pid;
1855	else
1856		pid = current->tgid;
1857
1858	if ((file->f_flags & O_ACCMODE) == O_WRONLY)
1859		cFYI(1, "attempting read on write only file instance");
1860
1861	for (total_read = 0, current_offset = read_data;
1862	     read_size > total_read;
1863	     total_read += bytes_read, current_offset += bytes_read) {
1864		current_read_size = min_t(const int, read_size - total_read,
1865					  cifs_sb->rsize);
1866		/* For windows me and 9x we do not want to request more
1867		than it negotiated since it will refuse the read then */
1868		if ((pTcon->ses) &&
1869			!(pTcon->ses->capabilities & CAP_LARGE_FILES)) {
1870			current_read_size = min_t(const int, current_read_size,
1871					pTcon->ses->server->maxBuf - 128);
1872		}
1873		rc = -EAGAIN;
1874		while (rc == -EAGAIN) {
1875			if (open_file->invalidHandle) {
1876				rc = cifs_reopen_file(open_file, true);
1877				if (rc != 0)
1878					break;
1879			}
1880			io_parms.netfid = open_file->netfid;
1881			io_parms.pid = pid;
1882			io_parms.tcon = pTcon;
1883			io_parms.offset = *poffset;
1884			io_parms.length = current_read_size;
1885			rc = CIFSSMBRead(xid, &io_parms, &bytes_read,
1886					 &current_offset, &buf_type);
1887		}
1888		if (rc || (bytes_read == 0)) {
1889			if (total_read) {
1890				break;
1891			} else {
1892				FreeXid(xid);
1893				return rc;
1894			}
1895		} else {
1896			cifs_stats_bytes_read(pTcon, total_read);
1897			*poffset += bytes_read;
1898		}
1899	}
1900	FreeXid(xid);
1901	return total_read;
1902}
1903
1904/*
1905 * If the page is mmap'ed into a process' page tables, then we need to make
1906 * sure that it doesn't change while being written back.
1907 */
1908static int
1909cifs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
1910{
1911	struct page *page = vmf->page;
1912
1913	lock_page(page);
1914	return VM_FAULT_LOCKED;
1915}
1916
1917static struct vm_operations_struct cifs_file_vm_ops = {
1918	.fault = filemap_fault,
1919	.page_mkwrite = cifs_page_mkwrite,
1920};
1921
1922int cifs_file_strict_mmap(struct file *file, struct vm_area_struct *vma)
1923{
1924	int rc, xid;
1925	struct inode *inode = file->f_path.dentry->d_inode;
1926
1927	xid = GetXid();
1928
1929	if (!CIFS_I(inode)->clientCanCacheRead) {
1930		rc = cifs_invalidate_mapping(inode);
1931		if (rc)
1932			return rc;
1933	}
1934
1935	rc = generic_file_mmap(file, vma);
1936	if (rc == 0)
1937		vma->vm_ops = &cifs_file_vm_ops;
1938	FreeXid(xid);
1939	return rc;
1940}
1941
1942int cifs_file_mmap(struct file *file, struct vm_area_struct *vma)
1943{
1944	int rc, xid;
1945
1946	xid = GetXid();
1947	rc = cifs_revalidate_file(file);
1948	if (rc) {
1949		cFYI(1, "Validation prior to mmap failed, error=%d", rc);
1950		FreeXid(xid);
1951		return rc;
1952	}
1953	rc = generic_file_mmap(file, vma);
1954	if (rc == 0)
1955		vma->vm_ops = &cifs_file_vm_ops;
1956	FreeXid(xid);
1957	return rc;
1958}
1959
1960
1961static void cifs_copy_cache_pages(struct address_space *mapping,
1962	struct list_head *pages, int bytes_read, char *data)
1963{
1964	struct page *page;
1965	char *target;
1966
1967	while (bytes_read > 0) {
1968		if (list_empty(pages))
1969			break;
1970
1971		page = list_entry(pages->prev, struct page, lru);
1972		list_del(&page->lru);
 
1973
1974		if (add_to_page_cache_lru(page, mapping, page->index,
1975				      GFP_KERNEL)) {
1976			page_cache_release(page);
1977			cFYI(1, "Add page cache failed");
1978			data += PAGE_CACHE_SIZE;
1979			bytes_read -= PAGE_CACHE_SIZE;
1980			continue;
1981		}
1982		page_cache_release(page);
1983
1984		target = kmap_atomic(page, KM_USER0);
1985
1986		if (PAGE_CACHE_SIZE > bytes_read) {
1987			memcpy(target, data, bytes_read);
1988			/* zero the tail end of this partial page */
1989			memset(target + bytes_read, 0,
1990			       PAGE_CACHE_SIZE - bytes_read);
1991			bytes_read = 0;
1992		} else {
1993			memcpy(target, data, PAGE_CACHE_SIZE);
1994			bytes_read -= PAGE_CACHE_SIZE;
1995		}
1996		kunmap_atomic(target, KM_USER0);
1997
1998		flush_dcache_page(page);
1999		SetPageUptodate(page);
2000		unlock_page(page);
2001		data += PAGE_CACHE_SIZE;
2002
2003		/* add page to FS-Cache */
2004		cifs_readpage_to_fscache(mapping->host, page);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2005	}
2006	return;
 
2007}
2008
2009static int cifs_readpages(struct file *file, struct address_space *mapping,
2010	struct list_head *page_list, unsigned num_pages)
2011{
2012	int rc = -EACCES;
2013	int xid;
2014	loff_t offset;
2015	struct page *page;
2016	struct cifs_sb_info *cifs_sb;
2017	struct cifs_tcon *pTcon;
2018	unsigned int bytes_read = 0;
2019	unsigned int read_size, i;
2020	char *smb_read_data = NULL;
2021	struct smb_com_read_rsp *pSMBr;
2022	struct cifsFileInfo *open_file;
2023	struct cifs_io_parms io_parms;
2024	int buf_type = CIFS_NO_BUFFER;
2025	__u32 pid;
2026
2027	xid = GetXid();
2028	if (file->private_data == NULL) {
2029		rc = -EBADF;
2030		FreeXid(xid);
2031		return rc;
2032	}
2033	open_file = file->private_data;
2034	cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
2035	pTcon = tlink_tcon(open_file->tlink);
2036
2037	/*
2038	 * Reads as many pages as possible from fscache. Returns -ENOBUFS
2039	 * immediately if the cookie is negative
2040	 */
2041	rc = cifs_readpages_from_fscache(mapping->host, mapping, page_list,
2042					 &num_pages);
2043	if (rc == 0)
2044		goto read_complete;
2045
2046	cFYI(DBG2, "rpages: num pages %d", num_pages);
2047	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
2048		pid = open_file->pid;
2049	else
2050		pid = current->tgid;
2051
2052	for (i = 0; i < num_pages; ) {
2053		unsigned contig_pages;
2054		struct page *tmp_page;
2055		unsigned long expected_index;
2056
2057		if (list_empty(page_list))
2058			break;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2059
2060		page = list_entry(page_list->prev, struct page, lru);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2061		offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
 
2062
2063		/* count adjacent pages that we will read into */
2064		contig_pages = 0;
2065		expected_index =
2066			list_entry(page_list->prev, struct page, lru)->index;
2067		list_for_each_entry_reverse(tmp_page, page_list, lru) {
2068			if (tmp_page->index == expected_index) {
2069				contig_pages++;
2070				expected_index++;
2071			} else
2072				break;
2073		}
2074		if (contig_pages + i >  num_pages)
2075			contig_pages = num_pages - i;
2076
2077		/* for reads over a certain size could initiate async
2078		   read ahead */
 
2079
2080		read_size = contig_pages * PAGE_CACHE_SIZE;
2081		/* Read size needs to be in multiples of one page */
2082		read_size = min_t(const unsigned int, read_size,
2083				  cifs_sb->rsize & PAGE_CACHE_MASK);
2084		cFYI(DBG2, "rpages: read size 0x%x  contiguous pages %d",
2085				read_size, contig_pages);
2086		rc = -EAGAIN;
2087		while (rc == -EAGAIN) {
2088			if (open_file->invalidHandle) {
2089				rc = cifs_reopen_file(open_file, true);
2090				if (rc != 0)
2091					break;
2092			}
2093			io_parms.netfid = open_file->netfid;
2094			io_parms.pid = pid;
2095			io_parms.tcon = pTcon;
2096			io_parms.offset = offset;
2097			io_parms.length = read_size;
2098			rc = CIFSSMBRead(xid, &io_parms, &bytes_read,
2099					 &smb_read_data, &buf_type);
2100			/* BB more RC checks ? */
2101			if (rc == -EAGAIN) {
2102				if (smb_read_data) {
2103					if (buf_type == CIFS_SMALL_BUFFER)
2104						cifs_small_buf_release(smb_read_data);
2105					else if (buf_type == CIFS_LARGE_BUFFER)
2106						cifs_buf_release(smb_read_data);
2107					smb_read_data = NULL;
2108				}
2109			}
 
 
 
 
2110		}
2111		if ((rc < 0) || (smb_read_data == NULL)) {
2112			cFYI(1, "Read error in readpages: %d", rc);
 
 
 
 
 
 
 
 
 
2113			break;
2114		} else if (bytes_read > 0) {
2115			task_io_account_read(bytes_read);
2116			pSMBr = (struct smb_com_read_rsp *)smb_read_data;
2117			cifs_copy_cache_pages(mapping, page_list, bytes_read,
2118				smb_read_data + 4 /* RFC1001 hdr */ +
2119				le16_to_cpu(pSMBr->DataOffset));
2120
2121			i +=  bytes_read >> PAGE_CACHE_SHIFT;
2122			cifs_stats_bytes_read(pTcon, bytes_read);
2123			if ((bytes_read & PAGE_CACHE_MASK) != bytes_read) {
2124				i++; /* account for partial page */
2125
2126				/* server copy of file can have smaller size
2127				   than client */
2128				/* BB do we need to verify this common case ?
2129				   this case is ok - if we are at server EOF
2130				   we will hit it on next read */
2131
2132				/* break; */
 
 
 
 
 
 
 
2133			}
2134		} else {
2135			cFYI(1, "No bytes read (%d) at offset %lld . "
2136				"Cleaning remaining pages from readahead list",
2137				bytes_read, offset);
2138			/* BB turn off caching and do new lookup on
2139			   file size at server? */
2140			break;
2141		}
2142		if (smb_read_data) {
2143			if (buf_type == CIFS_SMALL_BUFFER)
2144				cifs_small_buf_release(smb_read_data);
2145			else if (buf_type == CIFS_LARGE_BUFFER)
2146				cifs_buf_release(smb_read_data);
2147			smb_read_data = NULL;
2148		}
2149		bytes_read = 0;
2150	}
2151
2152/* need to free smb_read_data buf before exit */
2153	if (smb_read_data) {
2154		if (buf_type == CIFS_SMALL_BUFFER)
2155			cifs_small_buf_release(smb_read_data);
2156		else if (buf_type == CIFS_LARGE_BUFFER)
2157			cifs_buf_release(smb_read_data);
2158		smb_read_data = NULL;
2159	}
2160
2161read_complete:
2162	FreeXid(xid);
2163	return rc;
2164}
2165
2166static int cifs_readpage_worker(struct file *file, struct page *page,
2167	loff_t *poffset)
2168{
2169	char *read_data;
2170	int rc;
2171
2172	/* Is the page cached? */
2173	rc = cifs_readpage_from_fscache(file->f_path.dentry->d_inode, page);
2174	if (rc == 0)
2175		goto read_complete;
2176
2177	page_cache_get(page);
2178	read_data = kmap(page);
2179	/* for reads over a certain size could initiate async read ahead */
2180
2181	rc = cifs_read(file, read_data, PAGE_CACHE_SIZE, poffset);
2182
2183	if (rc < 0)
2184		goto io_error;
2185	else
2186		cFYI(1, "Bytes read %d", rc);
2187
2188	file->f_path.dentry->d_inode->i_atime =
2189		current_fs_time(file->f_path.dentry->d_inode->i_sb);
2190
2191	if (PAGE_CACHE_SIZE > rc)
2192		memset(read_data + rc, 0, PAGE_CACHE_SIZE - rc);
2193
2194	flush_dcache_page(page);
2195	SetPageUptodate(page);
2196
2197	/* send this page to the cache */
2198	cifs_readpage_to_fscache(file->f_path.dentry->d_inode, page);
2199
2200	rc = 0;
2201
2202io_error:
2203	kunmap(page);
2204	page_cache_release(page);
2205
2206read_complete:
2207	return rc;
2208}
2209
2210static int cifs_readpage(struct file *file, struct page *page)
2211{
2212	loff_t offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
2213	int rc = -EACCES;
2214	int xid;
2215
2216	xid = GetXid();
2217
2218	if (file->private_data == NULL) {
2219		rc = -EBADF;
2220		FreeXid(xid);
2221		return rc;
2222	}
2223
2224	cFYI(1, "readpage %p at offset %d 0x%x\n",
2225		 page, (int)offset, (int)offset);
2226
2227	rc = cifs_readpage_worker(file, page, &offset);
2228
2229	unlock_page(page);
2230
2231	FreeXid(xid);
2232	return rc;
2233}
2234
2235static int is_inode_writable(struct cifsInodeInfo *cifs_inode)
2236{
2237	struct cifsFileInfo *open_file;
2238
2239	spin_lock(&cifs_file_list_lock);
2240	list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
2241		if (OPEN_FMODE(open_file->f_flags) & FMODE_WRITE) {
2242			spin_unlock(&cifs_file_list_lock);
2243			return 1;
2244		}
2245	}
2246	spin_unlock(&cifs_file_list_lock);
2247	return 0;
2248}
2249
2250/* We do not want to update the file size from server for inodes
2251   open for write - to avoid races with writepage extending
2252   the file - in the future we could consider allowing
2253   refreshing the inode only on increases in the file size
2254   but this is tricky to do without racing with writebehind
2255   page caching in the current Linux kernel design */
2256bool is_size_safe_to_change(struct cifsInodeInfo *cifsInode, __u64 end_of_file)
2257{
2258	if (!cifsInode)
2259		return true;
2260
2261	if (is_inode_writable(cifsInode)) {
2262		/* This inode is open for write at least once */
2263		struct cifs_sb_info *cifs_sb;
2264
2265		cifs_sb = CIFS_SB(cifsInode->vfs_inode.i_sb);
2266		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DIRECT_IO) {
2267			/* since no page cache to corrupt on directio
2268			we can change size safely */
2269			return true;
2270		}
2271
2272		if (i_size_read(&cifsInode->vfs_inode) < end_of_file)
2273			return true;
2274
2275		return false;
2276	} else
2277		return true;
2278}
2279
2280static int cifs_write_begin(struct file *file, struct address_space *mapping,
2281			loff_t pos, unsigned len, unsigned flags,
2282			struct page **pagep, void **fsdata)
2283{
2284	pgoff_t index = pos >> PAGE_CACHE_SHIFT;
2285	loff_t offset = pos & (PAGE_CACHE_SIZE - 1);
2286	loff_t page_start = pos & PAGE_MASK;
2287	loff_t i_size;
2288	struct page *page;
2289	int rc = 0;
2290
2291	cFYI(1, "write_begin from %lld len %d", (long long)pos, len);
2292
2293	page = grab_cache_page_write_begin(mapping, index, flags);
2294	if (!page) {
2295		rc = -ENOMEM;
2296		goto out;
2297	}
2298
2299	if (PageUptodate(page))
2300		goto out;
2301
2302	/*
2303	 * If we write a full page it will be up to date, no need to read from
2304	 * the server. If the write is short, we'll end up doing a sync write
2305	 * instead.
2306	 */
2307	if (len == PAGE_CACHE_SIZE)
2308		goto out;
2309
2310	/*
2311	 * optimize away the read when we have an oplock, and we're not
2312	 * expecting to use any of the data we'd be reading in. That
2313	 * is, when the page lies beyond the EOF, or straddles the EOF
2314	 * and the write will cover all of the existing data.
2315	 */
2316	if (CIFS_I(mapping->host)->clientCanCacheRead) {
2317		i_size = i_size_read(mapping->host);
2318		if (page_start >= i_size ||
2319		    (offset == 0 && (pos + len) >= i_size)) {
2320			zero_user_segments(page, 0, offset,
2321					   offset + len,
2322					   PAGE_CACHE_SIZE);
2323			/*
2324			 * PageChecked means that the parts of the page
2325			 * to which we're not writing are considered up
2326			 * to date. Once the data is copied to the
2327			 * page, it can be set uptodate.
2328			 */
2329			SetPageChecked(page);
2330			goto out;
2331		}
2332	}
2333
2334	if ((file->f_flags & O_ACCMODE) != O_WRONLY) {
2335		/*
2336		 * might as well read a page, it is fast enough. If we get
2337		 * an error, we don't need to return it. cifs_write_end will
2338		 * do a sync write instead since PG_uptodate isn't set.
2339		 */
2340		cifs_readpage_worker(file, page, &page_start);
2341	} else {
2342		/* we could try using another file handle if there is one -
2343		   but how would we lock it to prevent close of that handle
2344		   racing with this read? In any case
2345		   this will be written out by write_end so is fine */
2346	}
2347out:
2348	*pagep = page;
2349	return rc;
2350}
2351
2352static int cifs_release_page(struct page *page, gfp_t gfp)
2353{
2354	if (PagePrivate(page))
2355		return 0;
2356
2357	return cifs_fscache_release_page(page, gfp);
2358}
2359
2360static void cifs_invalidate_page(struct page *page, unsigned long offset)
2361{
2362	struct cifsInodeInfo *cifsi = CIFS_I(page->mapping->host);
2363
2364	if (offset == 0)
2365		cifs_fscache_invalidate_page(page, &cifsi->vfs_inode);
2366}
2367
2368static int cifs_launder_page(struct page *page)
2369{
2370	int rc = 0;
2371	loff_t range_start = page_offset(page);
2372	loff_t range_end = range_start + (loff_t)(PAGE_CACHE_SIZE - 1);
2373	struct writeback_control wbc = {
2374		.sync_mode = WB_SYNC_ALL,
2375		.nr_to_write = 0,
2376		.range_start = range_start,
2377		.range_end = range_end,
2378	};
2379
2380	cFYI(1, "Launder page: %p", page);
2381
2382	if (clear_page_dirty_for_io(page))
2383		rc = cifs_writepage_locked(page, &wbc);
2384
2385	cifs_fscache_invalidate_page(page, page->mapping->host);
2386	return rc;
2387}
2388
2389void cifs_oplock_break(struct work_struct *work)
2390{
2391	struct cifsFileInfo *cfile = container_of(work, struct cifsFileInfo,
2392						  oplock_break);
2393	struct inode *inode = cfile->dentry->d_inode;
2394	struct cifsInodeInfo *cinode = CIFS_I(inode);
2395	int rc = 0;
2396
2397	if (inode && S_ISREG(inode->i_mode)) {
2398		if (cinode->clientCanCacheRead)
2399			break_lease(inode, O_RDONLY);
2400		else
2401			break_lease(inode, O_WRONLY);
2402		rc = filemap_fdatawrite(inode->i_mapping);
2403		if (cinode->clientCanCacheRead == 0) {
2404			rc = filemap_fdatawait(inode->i_mapping);
2405			mapping_set_error(inode->i_mapping, rc);
2406			invalidate_remote_inode(inode);
2407		}
2408		cFYI(1, "Oplock flush inode %p rc %d", inode, rc);
2409	}
2410
 
 
 
 
2411	/*
2412	 * releasing stale oplock after recent reconnect of smb session using
2413	 * a now incorrect file handle is not a data integrity issue but do
2414	 * not bother sending an oplock release if session to server still is
2415	 * disconnected since oplock already released by the server
2416	 */
2417	if (!cfile->oplock_break_cancelled) {
2418		rc = CIFSSMBLock(0, tlink_tcon(cfile->tlink), cfile->netfid, 0,
2419				 0, 0, 0, LOCKING_ANDX_OPLOCK_RELEASE, false,
 
2420				 cinode->clientCanCacheRead ? 1 : 0);
2421		cFYI(1, "Oplock release rc = %d", rc);
2422	}
2423}
2424
2425const struct address_space_operations cifs_addr_ops = {
2426	.readpage = cifs_readpage,
2427	.readpages = cifs_readpages,
2428	.writepage = cifs_writepage,
2429	.writepages = cifs_writepages,
2430	.write_begin = cifs_write_begin,
2431	.write_end = cifs_write_end,
2432	.set_page_dirty = __set_page_dirty_nobuffers,
2433	.releasepage = cifs_release_page,
2434	.invalidatepage = cifs_invalidate_page,
2435	.launder_page = cifs_launder_page,
2436};
2437
2438/*
2439 * cifs_readpages requires the server to support a buffer large enough to
2440 * contain the header plus one complete page of data.  Otherwise, we need
2441 * to leave cifs_readpages out of the address space operations.
2442 */
2443const struct address_space_operations cifs_addr_ops_smallbuf = {
2444	.readpage = cifs_readpage,
2445	.writepage = cifs_writepage,
2446	.writepages = cifs_writepages,
2447	.write_begin = cifs_write_begin,
2448	.write_end = cifs_write_end,
2449	.set_page_dirty = __set_page_dirty_nobuffers,
2450	.releasepage = cifs_release_page,
2451	.invalidatepage = cifs_invalidate_page,
2452	.launder_page = cifs_launder_page,
2453};