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v3.1
   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};
v4.17
   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 <linux/swap.h>
  36#include <asm/div64.h>
  37#include "cifsfs.h"
  38#include "cifspdu.h"
  39#include "cifsglob.h"
  40#include "cifsproto.h"
  41#include "cifs_unicode.h"
  42#include "cifs_debug.h"
  43#include "cifs_fs_sb.h"
  44#include "fscache.h"
  45#include "smbdirect.h"
  46
  47static inline int cifs_convert_flags(unsigned int flags)
  48{
  49	if ((flags & O_ACCMODE) == O_RDONLY)
  50		return GENERIC_READ;
  51	else if ((flags & O_ACCMODE) == O_WRONLY)
  52		return GENERIC_WRITE;
  53	else if ((flags & O_ACCMODE) == O_RDWR) {
  54		/* GENERIC_ALL is too much permission to request
  55		   can cause unnecessary access denied on create */
  56		/* return GENERIC_ALL; */
  57		return (GENERIC_READ | GENERIC_WRITE);
  58	}
  59
  60	return (READ_CONTROL | FILE_WRITE_ATTRIBUTES | FILE_READ_ATTRIBUTES |
  61		FILE_WRITE_EA | FILE_APPEND_DATA | FILE_WRITE_DATA |
  62		FILE_READ_DATA);
  63}
  64
  65static u32 cifs_posix_convert_flags(unsigned int flags)
  66{
  67	u32 posix_flags = 0;
  68
  69	if ((flags & O_ACCMODE) == O_RDONLY)
  70		posix_flags = SMB_O_RDONLY;
  71	else if ((flags & O_ACCMODE) == O_WRONLY)
  72		posix_flags = SMB_O_WRONLY;
  73	else if ((flags & O_ACCMODE) == O_RDWR)
  74		posix_flags = SMB_O_RDWR;
  75
  76	if (flags & O_CREAT) {
  77		posix_flags |= SMB_O_CREAT;
  78		if (flags & O_EXCL)
  79			posix_flags |= SMB_O_EXCL;
  80	} else if (flags & O_EXCL)
  81		cifs_dbg(FYI, "Application %s pid %d has incorrectly set O_EXCL flag but not O_CREAT on file open. Ignoring O_EXCL\n",
  82			 current->comm, current->tgid);
  83
  84	if (flags & O_TRUNC)
  85		posix_flags |= SMB_O_TRUNC;
  86	/* be safe and imply O_SYNC for O_DSYNC */
  87	if (flags & O_DSYNC)
  88		posix_flags |= SMB_O_SYNC;
  89	if (flags & O_DIRECTORY)
  90		posix_flags |= SMB_O_DIRECTORY;
  91	if (flags & O_NOFOLLOW)
  92		posix_flags |= SMB_O_NOFOLLOW;
  93	if (flags & O_DIRECT)
  94		posix_flags |= SMB_O_DIRECT;
  95
  96	return posix_flags;
  97}
  98
  99static inline int cifs_get_disposition(unsigned int flags)
 100{
 101	if ((flags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
 102		return FILE_CREATE;
 103	else if ((flags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
 104		return FILE_OVERWRITE_IF;
 105	else if ((flags & O_CREAT) == O_CREAT)
 106		return FILE_OPEN_IF;
 107	else if ((flags & O_TRUNC) == O_TRUNC)
 108		return FILE_OVERWRITE;
 109	else
 110		return FILE_OPEN;
 111}
 112
 113int cifs_posix_open(char *full_path, struct inode **pinode,
 114			struct super_block *sb, int mode, unsigned int f_flags,
 115			__u32 *poplock, __u16 *pnetfid, unsigned int xid)
 116{
 117	int rc;
 118	FILE_UNIX_BASIC_INFO *presp_data;
 119	__u32 posix_flags = 0;
 120	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
 121	struct cifs_fattr fattr;
 122	struct tcon_link *tlink;
 123	struct cifs_tcon *tcon;
 124
 125	cifs_dbg(FYI, "posix open %s\n", full_path);
 126
 127	presp_data = kzalloc(sizeof(FILE_UNIX_BASIC_INFO), GFP_KERNEL);
 128	if (presp_data == NULL)
 129		return -ENOMEM;
 130
 131	tlink = cifs_sb_tlink(cifs_sb);
 132	if (IS_ERR(tlink)) {
 133		rc = PTR_ERR(tlink);
 134		goto posix_open_ret;
 135	}
 136
 137	tcon = tlink_tcon(tlink);
 138	mode &= ~current_umask();
 139
 140	posix_flags = cifs_posix_convert_flags(f_flags);
 141	rc = CIFSPOSIXCreate(xid, tcon, posix_flags, mode, pnetfid, presp_data,
 142			     poplock, full_path, cifs_sb->local_nls,
 143			     cifs_remap(cifs_sb));
 
 144	cifs_put_tlink(tlink);
 145
 146	if (rc)
 147		goto posix_open_ret;
 148
 149	if (presp_data->Type == cpu_to_le32(-1))
 150		goto posix_open_ret; /* open ok, caller does qpathinfo */
 151
 152	if (!pinode)
 153		goto posix_open_ret; /* caller does not need info */
 154
 155	cifs_unix_basic_to_fattr(&fattr, presp_data, cifs_sb);
 156
 157	/* get new inode and set it up */
 158	if (*pinode == NULL) {
 159		cifs_fill_uniqueid(sb, &fattr);
 160		*pinode = cifs_iget(sb, &fattr);
 161		if (!*pinode) {
 162			rc = -ENOMEM;
 163			goto posix_open_ret;
 164		}
 165	} else {
 166		cifs_fattr_to_inode(*pinode, &fattr);
 167	}
 168
 169posix_open_ret:
 170	kfree(presp_data);
 171	return rc;
 172}
 173
 174static int
 175cifs_nt_open(char *full_path, struct inode *inode, struct cifs_sb_info *cifs_sb,
 176	     struct cifs_tcon *tcon, unsigned int f_flags, __u32 *oplock,
 177	     struct cifs_fid *fid, unsigned int xid)
 178{
 179	int rc;
 180	int desired_access;
 181	int disposition;
 182	int create_options = CREATE_NOT_DIR;
 183	FILE_ALL_INFO *buf;
 184	struct TCP_Server_Info *server = tcon->ses->server;
 185	struct cifs_open_parms oparms;
 186
 187	if (!server->ops->open)
 188		return -ENOSYS;
 189
 190	desired_access = cifs_convert_flags(f_flags);
 191
 192/*********************************************************************
 193 *  open flag mapping table:
 194 *
 195 *	POSIX Flag            CIFS Disposition
 196 *	----------            ----------------
 197 *	O_CREAT               FILE_OPEN_IF
 198 *	O_CREAT | O_EXCL      FILE_CREATE
 199 *	O_CREAT | O_TRUNC     FILE_OVERWRITE_IF
 200 *	O_TRUNC               FILE_OVERWRITE
 201 *	none of the above     FILE_OPEN
 202 *
 203 *	Note that there is not a direct match between disposition
 204 *	FILE_SUPERSEDE (ie create whether or not file exists although
 205 *	O_CREAT | O_TRUNC is similar but truncates the existing
 206 *	file rather than creating a new file as FILE_SUPERSEDE does
 207 *	(which uses the attributes / metadata passed in on open call)
 208 *?
 209 *?  O_SYNC is a reasonable match to CIFS writethrough flag
 210 *?  and the read write flags match reasonably.  O_LARGEFILE
 211 *?  is irrelevant because largefile support is always used
 212 *?  by this client. Flags O_APPEND, O_DIRECT, O_DIRECTORY,
 213 *	 O_FASYNC, O_NOFOLLOW, O_NONBLOCK need further investigation
 214 *********************************************************************/
 215
 216	disposition = cifs_get_disposition(f_flags);
 217
 218	/* BB pass O_SYNC flag through on file attributes .. BB */
 219
 220	buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
 221	if (!buf)
 222		return -ENOMEM;
 223
 224	if (backup_cred(cifs_sb))
 225		create_options |= CREATE_OPEN_BACKUP_INTENT;
 226
 227	/* O_SYNC also has bit for O_DSYNC so following check picks up either */
 228	if (f_flags & O_SYNC)
 229		create_options |= CREATE_WRITE_THROUGH;
 230
 231	if (f_flags & O_DIRECT)
 232		create_options |= CREATE_NO_BUFFER;
 233
 234	oparms.tcon = tcon;
 235	oparms.cifs_sb = cifs_sb;
 236	oparms.desired_access = desired_access;
 237	oparms.create_options = create_options;
 238	oparms.disposition = disposition;
 239	oparms.path = full_path;
 240	oparms.fid = fid;
 241	oparms.reconnect = false;
 242
 243	rc = server->ops->open(xid, &oparms, oplock, buf);
 244
 245	if (rc)
 246		goto out;
 247
 248	if (tcon->unix_ext)
 249		rc = cifs_get_inode_info_unix(&inode, full_path, inode->i_sb,
 250					      xid);
 251	else
 252		rc = cifs_get_inode_info(&inode, full_path, buf, inode->i_sb,
 253					 xid, fid);
 254
 255out:
 256	kfree(buf);
 257	return rc;
 258}
 259
 260static bool
 261cifs_has_mand_locks(struct cifsInodeInfo *cinode)
 262{
 263	struct cifs_fid_locks *cur;
 264	bool has_locks = false;
 265
 266	down_read(&cinode->lock_sem);
 267	list_for_each_entry(cur, &cinode->llist, llist) {
 268		if (!list_empty(&cur->locks)) {
 269			has_locks = true;
 270			break;
 271		}
 272	}
 273	up_read(&cinode->lock_sem);
 274	return has_locks;
 275}
 276
 277struct cifsFileInfo *
 278cifs_new_fileinfo(struct cifs_fid *fid, struct file *file,
 279		  struct tcon_link *tlink, __u32 oplock)
 280{
 281	struct dentry *dentry = file_dentry(file);
 282	struct inode *inode = d_inode(dentry);
 283	struct cifsInodeInfo *cinode = CIFS_I(inode);
 284	struct cifsFileInfo *cfile;
 285	struct cifs_fid_locks *fdlocks;
 286	struct cifs_tcon *tcon = tlink_tcon(tlink);
 287	struct TCP_Server_Info *server = tcon->ses->server;
 288
 289	cfile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
 290	if (cfile == NULL)
 291		return cfile;
 292
 293	fdlocks = kzalloc(sizeof(struct cifs_fid_locks), GFP_KERNEL);
 294	if (!fdlocks) {
 295		kfree(cfile);
 296		return NULL;
 297	}
 298
 299	INIT_LIST_HEAD(&fdlocks->locks);
 300	fdlocks->cfile = cfile;
 301	cfile->llist = fdlocks;
 302	down_write(&cinode->lock_sem);
 303	list_add(&fdlocks->llist, &cinode->llist);
 304	up_write(&cinode->lock_sem);
 305
 306	cfile->count = 1;
 307	cfile->pid = current->tgid;
 308	cfile->uid = current_fsuid();
 309	cfile->dentry = dget(dentry);
 310	cfile->f_flags = file->f_flags;
 311	cfile->invalidHandle = false;
 312	cfile->tlink = cifs_get_tlink(tlink);
 313	INIT_WORK(&cfile->oplock_break, cifs_oplock_break);
 314	mutex_init(&cfile->fh_mutex);
 315	spin_lock_init(&cfile->file_info_lock);
 316
 317	cifs_sb_active(inode->i_sb);
 318
 319	/*
 320	 * If the server returned a read oplock and we have mandatory brlocks,
 321	 * set oplock level to None.
 322	 */
 323	if (server->ops->is_read_op(oplock) && cifs_has_mand_locks(cinode)) {
 324		cifs_dbg(FYI, "Reset oplock val from read to None due to mand locks\n");
 325		oplock = 0;
 326	}
 327
 328	spin_lock(&tcon->open_file_lock);
 329	if (fid->pending_open->oplock != CIFS_OPLOCK_NO_CHANGE && oplock)
 330		oplock = fid->pending_open->oplock;
 331	list_del(&fid->pending_open->olist);
 332
 333	fid->purge_cache = false;
 334	server->ops->set_fid(cfile, fid, oplock);
 335
 336	list_add(&cfile->tlist, &tcon->openFileList);
 337
 
 
 338	/* if readable file instance put first in list*/
 339	if (file->f_mode & FMODE_READ)
 340		list_add(&cfile->flist, &cinode->openFileList);
 341	else
 342		list_add_tail(&cfile->flist, &cinode->openFileList);
 343	spin_unlock(&tcon->open_file_lock);
 344
 345	if (fid->purge_cache)
 346		cifs_zap_mapping(inode);
 347
 348	file->private_data = cfile;
 349	return cfile;
 350}
 351
 352struct cifsFileInfo *
 353cifsFileInfo_get(struct cifsFileInfo *cifs_file)
 354{
 355	spin_lock(&cifs_file->file_info_lock);
 356	cifsFileInfo_get_locked(cifs_file);
 357	spin_unlock(&cifs_file->file_info_lock);
 358	return cifs_file;
 359}
 360
 361/*
 362 * Release a reference on the file private data. This may involve closing
 363 * the filehandle out on the server. Must be called without holding
 364 * tcon->open_file_lock and cifs_file->file_info_lock.
 365 */
 366void cifsFileInfo_put(struct cifsFileInfo *cifs_file)
 367{
 368	struct inode *inode = d_inode(cifs_file->dentry);
 369	struct cifs_tcon *tcon = tlink_tcon(cifs_file->tlink);
 370	struct TCP_Server_Info *server = tcon->ses->server;
 371	struct cifsInodeInfo *cifsi = CIFS_I(inode);
 372	struct super_block *sb = inode->i_sb;
 373	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
 374	struct cifsLockInfo *li, *tmp;
 375	struct cifs_fid fid;
 376	struct cifs_pending_open open;
 377	bool oplock_break_cancelled;
 378
 379	spin_lock(&tcon->open_file_lock);
 380
 381	spin_lock(&cifs_file->file_info_lock);
 382	if (--cifs_file->count > 0) {
 383		spin_unlock(&cifs_file->file_info_lock);
 384		spin_unlock(&tcon->open_file_lock);
 385		return;
 386	}
 387	spin_unlock(&cifs_file->file_info_lock);
 388
 389	if (server->ops->get_lease_key)
 390		server->ops->get_lease_key(inode, &fid);
 391
 392	/* store open in pending opens to make sure we don't miss lease break */
 393	cifs_add_pending_open_locked(&fid, cifs_file->tlink, &open);
 394
 395	/* remove it from the lists */
 396	list_del(&cifs_file->flist);
 397	list_del(&cifs_file->tlist);
 398
 399	if (list_empty(&cifsi->openFileList)) {
 400		cifs_dbg(FYI, "closing last open instance for inode %p\n",
 401			 d_inode(cifs_file->dentry));
 402		/*
 403		 * In strict cache mode we need invalidate mapping on the last
 404		 * close  because it may cause a error when we open this file
 405		 * again and get at least level II oplock.
 406		 */
 407		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_STRICT_IO)
 408			set_bit(CIFS_INO_INVALID_MAPPING, &cifsi->flags);
 
 409		cifs_set_oplock_level(cifsi, 0);
 410	}
 
 411
 412	spin_unlock(&tcon->open_file_lock);
 413
 414	oplock_break_cancelled = cancel_work_sync(&cifs_file->oplock_break);
 415
 416	if (!tcon->need_reconnect && !cifs_file->invalidHandle) {
 417		struct TCP_Server_Info *server = tcon->ses->server;
 418		unsigned int xid;
 419
 420		xid = get_xid();
 421		if (server->ops->close)
 422			server->ops->close(xid, tcon, &cifs_file->fid);
 423		_free_xid(xid);
 424	}
 425
 426	if (oplock_break_cancelled)
 427		cifs_done_oplock_break(cifsi);
 428
 429	cifs_del_pending_open(&open);
 430
 431	/*
 432	 * Delete any outstanding lock records. We'll lose them when the file
 433	 * is closed anyway.
 434	 */
 435	down_write(&cifsi->lock_sem);
 436	list_for_each_entry_safe(li, tmp, &cifs_file->llist->locks, llist) {
 437		list_del(&li->llist);
 438		cifs_del_lock_waiters(li);
 439		kfree(li);
 440	}
 441	list_del(&cifs_file->llist->llist);
 442	kfree(cifs_file->llist);
 443	up_write(&cifsi->lock_sem);
 444
 445	cifs_put_tlink(cifs_file->tlink);
 446	dput(cifs_file->dentry);
 447	cifs_sb_deactive(sb);
 448	kfree(cifs_file);
 449}
 450
 451int cifs_open(struct inode *inode, struct file *file)
 452
 453{
 454	int rc = -EACCES;
 455	unsigned int xid;
 456	__u32 oplock;
 457	struct cifs_sb_info *cifs_sb;
 458	struct TCP_Server_Info *server;
 459	struct cifs_tcon *tcon;
 460	struct tcon_link *tlink;
 461	struct cifsFileInfo *cfile = NULL;
 462	char *full_path = NULL;
 463	bool posix_open_ok = false;
 464	struct cifs_fid fid;
 465	struct cifs_pending_open open;
 466
 467	xid = get_xid();
 468
 469	cifs_sb = CIFS_SB(inode->i_sb);
 470	tlink = cifs_sb_tlink(cifs_sb);
 471	if (IS_ERR(tlink)) {
 472		free_xid(xid);
 473		return PTR_ERR(tlink);
 474	}
 475	tcon = tlink_tcon(tlink);
 476	server = tcon->ses->server;
 477
 478	full_path = build_path_from_dentry(file_dentry(file));
 479	if (full_path == NULL) {
 480		rc = -ENOMEM;
 481		goto out;
 482	}
 483
 484	cifs_dbg(FYI, "inode = 0x%p file flags are 0x%x for %s\n",
 485		 inode, file->f_flags, full_path);
 486
 487	if (file->f_flags & O_DIRECT &&
 488	    cifs_sb->mnt_cifs_flags & CIFS_MOUNT_STRICT_IO) {
 489		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_BRL)
 490			file->f_op = &cifs_file_direct_nobrl_ops;
 491		else
 492			file->f_op = &cifs_file_direct_ops;
 493	}
 494
 495	if (server->oplocks)
 496		oplock = REQ_OPLOCK;
 497	else
 498		oplock = 0;
 499
 500	if (!tcon->broken_posix_open && tcon->unix_ext &&
 501	    cap_unix(tcon->ses) && (CIFS_UNIX_POSIX_PATH_OPS_CAP &
 502				le64_to_cpu(tcon->fsUnixInfo.Capability))) {
 
 503		/* can not refresh inode info since size could be stale */
 504		rc = cifs_posix_open(full_path, &inode, inode->i_sb,
 505				cifs_sb->mnt_file_mode /* ignored */,
 506				file->f_flags, &oplock, &fid.netfid, xid);
 507		if (rc == 0) {
 508			cifs_dbg(FYI, "posix open succeeded\n");
 509			posix_open_ok = true;
 510		} else if ((rc == -EINVAL) || (rc == -EOPNOTSUPP)) {
 511			if (tcon->ses->serverNOS)
 512				cifs_dbg(VFS, "server %s of type %s returned unexpected error on SMB posix open, disabling posix open support. Check if server update available.\n",
 513					 tcon->ses->serverName,
 514					 tcon->ses->serverNOS);
 
 
 
 515			tcon->broken_posix_open = true;
 516		} else if ((rc != -EIO) && (rc != -EREMOTE) &&
 517			 (rc != -EOPNOTSUPP)) /* path not found or net err */
 518			goto out;
 519		/*
 520		 * Else fallthrough to retry open the old way on network i/o
 521		 * or DFS errors.
 522		 */
 523	}
 524
 525	if (server->ops->get_lease_key)
 526		server->ops->get_lease_key(inode, &fid);
 527
 528	cifs_add_pending_open(&fid, tlink, &open);
 529
 530	if (!posix_open_ok) {
 531		if (server->ops->get_lease_key)
 532			server->ops->get_lease_key(inode, &fid);
 533
 534		rc = cifs_nt_open(full_path, inode, cifs_sb, tcon,
 535				  file->f_flags, &oplock, &fid, xid);
 536		if (rc) {
 537			cifs_del_pending_open(&open);
 538			goto out;
 539		}
 540	}
 541
 542	cfile = cifs_new_fileinfo(&fid, file, tlink, oplock);
 543	if (cfile == NULL) {
 544		if (server->ops->close)
 545			server->ops->close(xid, tcon, &fid);
 546		cifs_del_pending_open(&open);
 547		rc = -ENOMEM;
 548		goto out;
 549	}
 550
 551	cifs_fscache_set_inode_cookie(inode, file);
 552
 553	if ((oplock & CIFS_CREATE_ACTION) && !posix_open_ok && tcon->unix_ext) {
 554		/*
 555		 * Time to set mode which we can not set earlier due to
 556		 * problems creating new read-only files.
 557		 */
 558		struct cifs_unix_set_info_args args = {
 559			.mode	= inode->i_mode,
 560			.uid	= INVALID_UID, /* no change */
 561			.gid	= INVALID_GID, /* no change */
 562			.ctime	= NO_CHANGE_64,
 563			.atime	= NO_CHANGE_64,
 564			.mtime	= NO_CHANGE_64,
 565			.device	= 0,
 566		};
 567		CIFSSMBUnixSetFileInfo(xid, tcon, &args, fid.netfid,
 568				       cfile->pid);
 569	}
 570
 571out:
 572	kfree(full_path);
 573	free_xid(xid);
 574	cifs_put_tlink(tlink);
 575	return rc;
 576}
 577
 578static int cifs_push_posix_locks(struct cifsFileInfo *cfile);
 579
 580/*
 581 * Try to reacquire byte range locks that were released when session
 582 * to server was lost.
 583 */
 584static int
 585cifs_relock_file(struct cifsFileInfo *cfile)
 586{
 587	struct cifs_sb_info *cifs_sb = CIFS_SB(cfile->dentry->d_sb);
 588	struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
 589	struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
 590	int rc = 0;
 591
 592	down_read_nested(&cinode->lock_sem, SINGLE_DEPTH_NESTING);
 593	if (cinode->can_cache_brlcks) {
 594		/* can cache locks - no need to relock */
 595		up_read(&cinode->lock_sem);
 596		return rc;
 597	}
 598
 599	if (cap_unix(tcon->ses) &&
 600	    (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
 601	    ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
 602		rc = cifs_push_posix_locks(cfile);
 603	else
 604		rc = tcon->ses->server->ops->push_mand_locks(cfile);
 605
 606	up_read(&cinode->lock_sem);
 607	return rc;
 608}
 609
 610static int
 611cifs_reopen_file(struct cifsFileInfo *cfile, bool can_flush)
 612{
 613	int rc = -EACCES;
 614	unsigned int xid;
 615	__u32 oplock;
 616	struct cifs_sb_info *cifs_sb;
 617	struct cifs_tcon *tcon;
 618	struct TCP_Server_Info *server;
 619	struct cifsInodeInfo *cinode;
 620	struct inode *inode;
 621	char *full_path = NULL;
 622	int desired_access;
 623	int disposition = FILE_OPEN;
 624	int create_options = CREATE_NOT_DIR;
 625	struct cifs_open_parms oparms;
 626
 627	xid = get_xid();
 628	mutex_lock(&cfile->fh_mutex);
 629	if (!cfile->invalidHandle) {
 630		mutex_unlock(&cfile->fh_mutex);
 631		rc = 0;
 632		free_xid(xid);
 633		return rc;
 634	}
 635
 636	inode = d_inode(cfile->dentry);
 637	cifs_sb = CIFS_SB(inode->i_sb);
 638	tcon = tlink_tcon(cfile->tlink);
 639	server = tcon->ses->server;
 640
 641	/*
 642	 * Can not grab rename sem here because various ops, including those
 643	 * that already have the rename sem can end up causing writepage to get
 644	 * called and if the server was down that means we end up here, and we
 645	 * can never tell if the caller already has the rename_sem.
 646	 */
 647	full_path = build_path_from_dentry(cfile->dentry);
 648	if (full_path == NULL) {
 649		rc = -ENOMEM;
 650		mutex_unlock(&cfile->fh_mutex);
 651		free_xid(xid);
 652		return rc;
 653	}
 654
 655	cifs_dbg(FYI, "inode = 0x%p file flags 0x%x for %s\n",
 656		 inode, cfile->f_flags, full_path);
 657
 658	if (tcon->ses->server->oplocks)
 659		oplock = REQ_OPLOCK;
 660	else
 661		oplock = 0;
 662
 663	if (tcon->unix_ext && cap_unix(tcon->ses) &&
 664	    (CIFS_UNIX_POSIX_PATH_OPS_CAP &
 665				le64_to_cpu(tcon->fsUnixInfo.Capability))) {
 
 666		/*
 667		 * O_CREAT, O_EXCL and O_TRUNC already had their effect on the
 668		 * original open. Must mask them off for a reopen.
 669		 */
 670		unsigned int oflags = cfile->f_flags &
 671						~(O_CREAT | O_EXCL | O_TRUNC);
 672
 673		rc = cifs_posix_open(full_path, NULL, inode->i_sb,
 674				     cifs_sb->mnt_file_mode /* ignored */,
 675				     oflags, &oplock, &cfile->fid.netfid, xid);
 676		if (rc == 0) {
 677			cifs_dbg(FYI, "posix reopen succeeded\n");
 678			oparms.reconnect = true;
 679			goto reopen_success;
 680		}
 681		/*
 682		 * fallthrough to retry open the old way on errors, especially
 683		 * in the reconnect path it is important to retry hard
 684		 */
 685	}
 686
 687	desired_access = cifs_convert_flags(cfile->f_flags);
 688
 689	if (backup_cred(cifs_sb))
 690		create_options |= CREATE_OPEN_BACKUP_INTENT;
 691
 692	if (server->ops->get_lease_key)
 693		server->ops->get_lease_key(inode, &cfile->fid);
 694
 695	oparms.tcon = tcon;
 696	oparms.cifs_sb = cifs_sb;
 697	oparms.desired_access = desired_access;
 698	oparms.create_options = create_options;
 699	oparms.disposition = disposition;
 700	oparms.path = full_path;
 701	oparms.fid = &cfile->fid;
 702	oparms.reconnect = true;
 703
 704	/*
 705	 * Can not refresh inode by passing in file_info buf to be returned by
 706	 * ops->open and then calling get_inode_info with returned buf since
 707	 * file might have write behind data that needs to be flushed and server
 708	 * version of file size can be stale. If we knew for sure that inode was
 709	 * not dirty locally we could do this.
 710	 */
 711	rc = server->ops->open(xid, &oparms, &oplock, NULL);
 712	if (rc == -ENOENT && oparms.reconnect == false) {
 713		/* durable handle timeout is expired - open the file again */
 714		rc = server->ops->open(xid, &oparms, &oplock, NULL);
 715		/* indicate that we need to relock the file */
 716		oparms.reconnect = true;
 717	}
 718
 
 
 
 
 
 
 
 
 
 
 719	if (rc) {
 720		mutex_unlock(&cfile->fh_mutex);
 721		cifs_dbg(FYI, "cifs_reopen returned 0x%x\n", rc);
 722		cifs_dbg(FYI, "oplock: %d\n", oplock);
 723		goto reopen_error_exit;
 724	}
 725
 726reopen_success:
 727	cfile->invalidHandle = false;
 728	mutex_unlock(&cfile->fh_mutex);
 729	cinode = CIFS_I(inode);
 
 730
 731	if (can_flush) {
 732		rc = filemap_write_and_wait(inode->i_mapping);
 733		mapping_set_error(inode->i_mapping, rc);
 734
 735		if (tcon->unix_ext)
 736			rc = cifs_get_inode_info_unix(&inode, full_path,
 737						      inode->i_sb, xid);
 738		else
 739			rc = cifs_get_inode_info(&inode, full_path, NULL,
 740						 inode->i_sb, xid, NULL);
 741	}
 742	/*
 743	 * Else we are writing out data to server already and could deadlock if
 744	 * we tried to flush data, and since we do not know if we have data that
 745	 * would invalidate the current end of file on the server we can not go
 746	 * to the server to get the new inode info.
 747	 */
 748
 749	/*
 750	 * If the server returned a read oplock and we have mandatory brlocks,
 751	 * set oplock level to None.
 752	 */
 753	if (server->ops->is_read_op(oplock) && cifs_has_mand_locks(cinode)) {
 754		cifs_dbg(FYI, "Reset oplock val from read to None due to mand locks\n");
 755		oplock = 0;
 756	}
 757
 758	server->ops->set_fid(cfile, &cfile->fid, oplock);
 759	if (oparms.reconnect)
 760		cifs_relock_file(cfile);
 761
 762reopen_error_exit:
 763	kfree(full_path);
 764	free_xid(xid);
 765	return rc;
 766}
 767
 768int cifs_close(struct inode *inode, struct file *file)
 769{
 770	if (file->private_data != NULL) {
 771		cifsFileInfo_put(file->private_data);
 772		file->private_data = NULL;
 773	}
 774
 775	/* return code from the ->release op is always ignored */
 776	return 0;
 777}
 778
 779void
 780cifs_reopen_persistent_handles(struct cifs_tcon *tcon)
 781{
 782	struct cifsFileInfo *open_file;
 783	struct list_head *tmp;
 784	struct list_head *tmp1;
 785	struct list_head tmp_list;
 786
 787	if (!tcon->use_persistent || !tcon->need_reopen_files)
 788		return;
 789
 790	tcon->need_reopen_files = false;
 791
 792	cifs_dbg(FYI, "Reopen persistent handles");
 793	INIT_LIST_HEAD(&tmp_list);
 794
 795	/* list all files open on tree connection, reopen resilient handles  */
 796	spin_lock(&tcon->open_file_lock);
 797	list_for_each(tmp, &tcon->openFileList) {
 798		open_file = list_entry(tmp, struct cifsFileInfo, tlist);
 799		if (!open_file->invalidHandle)
 800			continue;
 801		cifsFileInfo_get(open_file);
 802		list_add_tail(&open_file->rlist, &tmp_list);
 803	}
 804	spin_unlock(&tcon->open_file_lock);
 805
 806	list_for_each_safe(tmp, tmp1, &tmp_list) {
 807		open_file = list_entry(tmp, struct cifsFileInfo, rlist);
 808		if (cifs_reopen_file(open_file, false /* do not flush */))
 809			tcon->need_reopen_files = true;
 810		list_del_init(&open_file->rlist);
 811		cifsFileInfo_put(open_file);
 812	}
 813}
 814
 815int cifs_closedir(struct inode *inode, struct file *file)
 816{
 817	int rc = 0;
 818	unsigned int xid;
 819	struct cifsFileInfo *cfile = file->private_data;
 820	struct cifs_tcon *tcon;
 821	struct TCP_Server_Info *server;
 822	char *buf;
 823
 824	cifs_dbg(FYI, "Closedir inode = 0x%p\n", inode);
 825
 826	if (cfile == NULL)
 827		return rc;
 828
 829	xid = get_xid();
 830	tcon = tlink_tcon(cfile->tlink);
 831	server = tcon->ses->server;
 832
 833	cifs_dbg(FYI, "Freeing private data in close dir\n");
 834	spin_lock(&cfile->file_info_lock);
 835	if (server->ops->dir_needs_close(cfile)) {
 836		cfile->invalidHandle = true;
 837		spin_unlock(&cfile->file_info_lock);
 838		if (server->ops->close_dir)
 839			rc = server->ops->close_dir(xid, tcon, &cfile->fid);
 840		else
 841			rc = -ENOSYS;
 842		cifs_dbg(FYI, "Closing uncompleted readdir with rc %d\n", rc);
 843		/* not much we can do if it fails anyway, ignore rc */
 844		rc = 0;
 845	} else
 846		spin_unlock(&cfile->file_info_lock);
 847
 848	buf = cfile->srch_inf.ntwrk_buf_start;
 849	if (buf) {
 850		cifs_dbg(FYI, "closedir free smb buf in srch struct\n");
 851		cfile->srch_inf.ntwrk_buf_start = NULL;
 852		if (cfile->srch_inf.smallBuf)
 853			cifs_small_buf_release(buf);
 854		else
 855			cifs_buf_release(buf);
 856	}
 857
 858	cifs_put_tlink(cfile->tlink);
 859	kfree(file->private_data);
 860	file->private_data = NULL;
 861	/* BB can we lock the filestruct while this is going on? */
 862	free_xid(xid);
 863	return rc;
 864}
 865
 866static struct cifsLockInfo *
 867cifs_lock_init(__u64 offset, __u64 length, __u8 type)
 868{
 869	struct cifsLockInfo *lock =
 870		kmalloc(sizeof(struct cifsLockInfo), GFP_KERNEL);
 871	if (!lock)
 872		return lock;
 873	lock->offset = offset;
 874	lock->length = length;
 875	lock->type = type;
 876	lock->pid = current->tgid;
 877	INIT_LIST_HEAD(&lock->blist);
 878	init_waitqueue_head(&lock->block_q);
 879	return lock;
 880}
 881
 882void
 883cifs_del_lock_waiters(struct cifsLockInfo *lock)
 884{
 885	struct cifsLockInfo *li, *tmp;
 886	list_for_each_entry_safe(li, tmp, &lock->blist, blist) {
 887		list_del_init(&li->blist);
 888		wake_up(&li->block_q);
 889	}
 890}
 891
 892#define CIFS_LOCK_OP	0
 893#define CIFS_READ_OP	1
 894#define CIFS_WRITE_OP	2
 895
 896/* @rw_check : 0 - no op, 1 - read, 2 - write */
 897static bool
 898cifs_find_fid_lock_conflict(struct cifs_fid_locks *fdlocks, __u64 offset,
 899			    __u64 length, __u8 type, struct cifsFileInfo *cfile,
 900			    struct cifsLockInfo **conf_lock, int rw_check)
 901{
 902	struct cifsLockInfo *li;
 903	struct cifsFileInfo *cur_cfile = fdlocks->cfile;
 904	struct TCP_Server_Info *server = tlink_tcon(cfile->tlink)->ses->server;
 905
 906	list_for_each_entry(li, &fdlocks->locks, llist) {
 907		if (offset + length <= li->offset ||
 908		    offset >= li->offset + li->length)
 909			continue;
 910		if (rw_check != CIFS_LOCK_OP && current->tgid == li->pid &&
 911		    server->ops->compare_fids(cfile, cur_cfile)) {
 912			/* shared lock prevents write op through the same fid */
 913			if (!(li->type & server->vals->shared_lock_type) ||
 914			    rw_check != CIFS_WRITE_OP)
 915				continue;
 916		}
 917		if ((type & server->vals->shared_lock_type) &&
 918		    ((server->ops->compare_fids(cfile, cur_cfile) &&
 919		     current->tgid == li->pid) || type == li->type))
 920			continue;
 921		if (conf_lock)
 922			*conf_lock = li;
 923		return true;
 924	}
 925	return false;
 926}
 927
 928bool
 929cifs_find_lock_conflict(struct cifsFileInfo *cfile, __u64 offset, __u64 length,
 930			__u8 type, struct cifsLockInfo **conf_lock,
 931			int rw_check)
 932{
 933	bool rc = false;
 934	struct cifs_fid_locks *cur;
 935	struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
 936
 937	list_for_each_entry(cur, &cinode->llist, llist) {
 938		rc = cifs_find_fid_lock_conflict(cur, offset, length, type,
 939						 cfile, conf_lock, rw_check);
 940		if (rc)
 941			break;
 942	}
 943
 944	return rc;
 945}
 946
 947/*
 948 * Check if there is another lock that prevents us to set the lock (mandatory
 949 * style). If such a lock exists, update the flock structure with its
 950 * properties. Otherwise, set the flock type to F_UNLCK if we can cache brlocks
 951 * or leave it the same if we can't. Returns 0 if we don't need to request to
 952 * the server or 1 otherwise.
 953 */
 954static int
 955cifs_lock_test(struct cifsFileInfo *cfile, __u64 offset, __u64 length,
 956	       __u8 type, struct file_lock *flock)
 957{
 958	int rc = 0;
 959	struct cifsLockInfo *conf_lock;
 960	struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
 961	struct TCP_Server_Info *server = tlink_tcon(cfile->tlink)->ses->server;
 962	bool exist;
 963
 964	down_read(&cinode->lock_sem);
 965
 966	exist = cifs_find_lock_conflict(cfile, offset, length, type,
 967					&conf_lock, CIFS_LOCK_OP);
 968	if (exist) {
 969		flock->fl_start = conf_lock->offset;
 970		flock->fl_end = conf_lock->offset + conf_lock->length - 1;
 971		flock->fl_pid = conf_lock->pid;
 972		if (conf_lock->type & server->vals->shared_lock_type)
 973			flock->fl_type = F_RDLCK;
 974		else
 975			flock->fl_type = F_WRLCK;
 976	} else if (!cinode->can_cache_brlcks)
 977		rc = 1;
 978	else
 979		flock->fl_type = F_UNLCK;
 980
 981	up_read(&cinode->lock_sem);
 982	return rc;
 983}
 984
 985static void
 986cifs_lock_add(struct cifsFileInfo *cfile, struct cifsLockInfo *lock)
 987{
 988	struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
 989	down_write(&cinode->lock_sem);
 990	list_add_tail(&lock->llist, &cfile->llist->locks);
 991	up_write(&cinode->lock_sem);
 992}
 993
 994/*
 995 * Set the byte-range lock (mandatory style). Returns:
 996 * 1) 0, if we set the lock and don't need to request to the server;
 997 * 2) 1, if no locks prevent us but we need to request to the server;
 998 * 3) -EACCESS, if there is a lock that prevents us and wait is false.
 999 */
1000static int
1001cifs_lock_add_if(struct cifsFileInfo *cfile, struct cifsLockInfo *lock,
1002		 bool wait)
1003{
1004	struct cifsLockInfo *conf_lock;
1005	struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
1006	bool exist;
1007	int rc = 0;
1008
1009try_again:
1010	exist = false;
1011	down_write(&cinode->lock_sem);
1012
1013	exist = cifs_find_lock_conflict(cfile, lock->offset, lock->length,
1014					lock->type, &conf_lock, CIFS_LOCK_OP);
1015	if (!exist && cinode->can_cache_brlcks) {
1016		list_add_tail(&lock->llist, &cfile->llist->locks);
1017		up_write(&cinode->lock_sem);
1018		return rc;
1019	}
1020
1021	if (!exist)
1022		rc = 1;
1023	else if (!wait)
1024		rc = -EACCES;
1025	else {
1026		list_add_tail(&lock->blist, &conf_lock->blist);
1027		up_write(&cinode->lock_sem);
1028		rc = wait_event_interruptible(lock->block_q,
1029					(lock->blist.prev == &lock->blist) &&
1030					(lock->blist.next == &lock->blist));
1031		if (!rc)
1032			goto try_again;
1033		down_write(&cinode->lock_sem);
1034		list_del_init(&lock->blist);
1035	}
1036
1037	up_write(&cinode->lock_sem);
1038	return rc;
1039}
1040
1041/*
1042 * Check if there is another lock that prevents us to set the lock (posix
1043 * style). If such a lock exists, update the flock structure with its
1044 * properties. Otherwise, set the flock type to F_UNLCK if we can cache brlocks
1045 * or leave it the same if we can't. Returns 0 if we don't need to request to
1046 * the server or 1 otherwise.
1047 */
1048static int
1049cifs_posix_lock_test(struct file *file, struct file_lock *flock)
1050{
1051	int rc = 0;
1052	struct cifsInodeInfo *cinode = CIFS_I(file_inode(file));
1053	unsigned char saved_type = flock->fl_type;
1054
1055	if ((flock->fl_flags & FL_POSIX) == 0)
1056		return 1;
1057
1058	down_read(&cinode->lock_sem);
1059	posix_test_lock(file, flock);
1060
1061	if (flock->fl_type == F_UNLCK && !cinode->can_cache_brlcks) {
1062		flock->fl_type = saved_type;
1063		rc = 1;
1064	}
1065
1066	up_read(&cinode->lock_sem);
1067	return rc;
1068}
1069
1070/*
1071 * Set the byte-range lock (posix style). Returns:
1072 * 1) 0, if we set the lock and don't need to request to the server;
1073 * 2) 1, if we need to request to the server;
1074 * 3) <0, if the error occurs while setting the lock.
1075 */
1076static int
1077cifs_posix_lock_set(struct file *file, struct file_lock *flock)
1078{
1079	struct cifsInodeInfo *cinode = CIFS_I(file_inode(file));
1080	int rc = 1;
1081
1082	if ((flock->fl_flags & FL_POSIX) == 0)
1083		return rc;
1084
1085try_again:
1086	down_write(&cinode->lock_sem);
1087	if (!cinode->can_cache_brlcks) {
1088		up_write(&cinode->lock_sem);
1089		return rc;
1090	}
1091
1092	rc = posix_lock_file(file, flock, NULL);
1093	up_write(&cinode->lock_sem);
1094	if (rc == FILE_LOCK_DEFERRED) {
1095		rc = wait_event_interruptible(flock->fl_wait, !flock->fl_next);
1096		if (!rc)
1097			goto try_again;
1098		posix_unblock_lock(flock);
1099	}
1100	return rc;
1101}
1102
1103int
1104cifs_push_mandatory_locks(struct cifsFileInfo *cfile)
1105{
1106	unsigned int xid;
1107	int rc = 0, stored_rc;
1108	struct cifsLockInfo *li, *tmp;
1109	struct cifs_tcon *tcon;
1110	unsigned int num, max_num, max_buf;
1111	LOCKING_ANDX_RANGE *buf, *cur;
1112	static const int types[] = {
1113		LOCKING_ANDX_LARGE_FILES,
1114		LOCKING_ANDX_SHARED_LOCK | LOCKING_ANDX_LARGE_FILES
1115	};
1116	int i;
1117
1118	xid = get_xid();
1119	tcon = tlink_tcon(cfile->tlink);
1120
1121	/*
1122	 * Accessing maxBuf is racy with cifs_reconnect - need to store value
1123	 * and check it for zero before using.
1124	 */
1125	max_buf = tcon->ses->server->maxBuf;
1126	if (!max_buf) {
1127		free_xid(xid);
1128		return -EINVAL;
1129	}
1130
1131	max_num = (max_buf - sizeof(struct smb_hdr)) /
1132						sizeof(LOCKING_ANDX_RANGE);
1133	buf = kcalloc(max_num, sizeof(LOCKING_ANDX_RANGE), GFP_KERNEL);
1134	if (!buf) {
1135		free_xid(xid);
1136		return -ENOMEM;
1137	}
1138
1139	for (i = 0; i < 2; i++) {
1140		cur = buf;
1141		num = 0;
1142		list_for_each_entry_safe(li, tmp, &cfile->llist->locks, llist) {
1143			if (li->type != types[i])
1144				continue;
1145			cur->Pid = cpu_to_le16(li->pid);
1146			cur->LengthLow = cpu_to_le32((u32)li->length);
1147			cur->LengthHigh = cpu_to_le32((u32)(li->length>>32));
1148			cur->OffsetLow = cpu_to_le32((u32)li->offset);
1149			cur->OffsetHigh = cpu_to_le32((u32)(li->offset>>32));
1150			if (++num == max_num) {
1151				stored_rc = cifs_lockv(xid, tcon,
1152						       cfile->fid.netfid,
1153						       (__u8)li->type, 0, num,
1154						       buf);
1155				if (stored_rc)
1156					rc = stored_rc;
1157				cur = buf;
1158				num = 0;
1159			} else
1160				cur++;
1161		}
1162
1163		if (num) {
1164			stored_rc = cifs_lockv(xid, tcon, cfile->fid.netfid,
1165					       (__u8)types[i], 0, num, buf);
1166			if (stored_rc)
1167				rc = stored_rc;
1168		}
1169	}
1170
1171	kfree(buf);
1172	free_xid(xid);
1173	return rc;
1174}
1175
1176static __u32
1177hash_lockowner(fl_owner_t owner)
1178{
1179	return cifs_lock_secret ^ hash32_ptr((const void *)owner);
1180}
1181
1182struct lock_to_push {
1183	struct list_head llist;
1184	__u64 offset;
1185	__u64 length;
1186	__u32 pid;
 
 
1187	__u16 netfid;
1188	__u8 type;
1189};
1190
1191static int
1192cifs_push_posix_locks(struct cifsFileInfo *cfile)
1193{
1194	struct inode *inode = d_inode(cfile->dentry);
1195	struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1196	struct file_lock *flock;
1197	struct file_lock_context *flctx = inode->i_flctx;
1198	unsigned int count = 0, i;
1199	int rc = 0, xid, type;
1200	struct list_head locks_to_send, *el;
1201	struct lock_to_push *lck, *tmp;
1202	__u64 length;
1203
1204	xid = get_xid();
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1205
1206	if (!flctx)
1207		goto out;
1208
1209	spin_lock(&flctx->flc_lock);
1210	list_for_each(el, &flctx->flc_posix) {
1211		count++;
1212	}
1213	spin_unlock(&flctx->flc_lock);
1214
1215	INIT_LIST_HEAD(&locks_to_send);
1216
1217	/*
1218	 * Allocating count locks is enough because no FL_POSIX locks can be
1219	 * added to the list while we are holding cinode->lock_sem that
1220	 * protects locking operations of this inode.
1221	 */
1222	for (i = 0; i < count; i++) {
1223		lck = kmalloc(sizeof(struct lock_to_push), GFP_KERNEL);
1224		if (!lck) {
1225			rc = -ENOMEM;
1226			goto err_out;
1227		}
1228		list_add_tail(&lck->llist, &locks_to_send);
1229	}
1230
1231	el = locks_to_send.next;
1232	spin_lock(&flctx->flc_lock);
1233	list_for_each_entry(flock, &flctx->flc_posix, fl_list) {
1234		if (el == &locks_to_send) {
1235			/*
1236			 * The list ended. We don't have enough allocated
1237			 * structures - something is really wrong.
1238			 */
1239			cifs_dbg(VFS, "Can't push all brlocks!\n");
1240			break;
1241		}
1242		length = 1 + flock->fl_end - flock->fl_start;
1243		if (flock->fl_type == F_RDLCK || flock->fl_type == F_SHLCK)
1244			type = CIFS_RDLCK;
1245		else
1246			type = CIFS_WRLCK;
1247		lck = list_entry(el, struct lock_to_push, llist);
1248		lck->pid = hash_lockowner(flock->fl_owner);
1249		lck->netfid = cfile->fid.netfid;
1250		lck->length = length;
1251		lck->type = type;
1252		lck->offset = flock->fl_start;
1253	}
1254	spin_unlock(&flctx->flc_lock);
1255
1256	list_for_each_entry_safe(lck, tmp, &locks_to_send, llist) {
1257		int stored_rc;
1258
1259		stored_rc = CIFSSMBPosixLock(xid, tcon, lck->netfid, lck->pid,
1260					     lck->offset, lck->length, NULL,
1261					     lck->type, 0);
1262		if (stored_rc)
1263			rc = stored_rc;
1264		list_del(&lck->llist);
1265		kfree(lck);
1266	}
1267
1268out:
1269	free_xid(xid);
1270	return rc;
1271err_out:
1272	list_for_each_entry_safe(lck, tmp, &locks_to_send, llist) {
1273		list_del(&lck->llist);
1274		kfree(lck);
1275	}
1276	goto out;
1277}
1278
1279static int
1280cifs_push_locks(struct cifsFileInfo *cfile)
1281{
1282	struct cifs_sb_info *cifs_sb = CIFS_SB(cfile->dentry->d_sb);
1283	struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
1284	struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1285	int rc = 0;
1286
1287	/* we are going to update can_cache_brlcks here - need a write access */
1288	down_write(&cinode->lock_sem);
1289	if (!cinode->can_cache_brlcks) {
1290		up_write(&cinode->lock_sem);
1291		return rc;
1292	}
1293
1294	if (cap_unix(tcon->ses) &&
1295	    (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
1296	    ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
1297		rc = cifs_push_posix_locks(cfile);
1298	else
1299		rc = tcon->ses->server->ops->push_mand_locks(cfile);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1300
1301	cinode->can_cache_brlcks = false;
1302	up_write(&cinode->lock_sem);
1303	return rc;
1304}
 
 
 
 
 
 
 
 
 
1305
1306static void
1307cifs_read_flock(struct file_lock *flock, __u32 *type, int *lock, int *unlock,
1308		bool *wait_flag, struct TCP_Server_Info *server)
1309{
1310	if (flock->fl_flags & FL_POSIX)
1311		cifs_dbg(FYI, "Posix\n");
1312	if (flock->fl_flags & FL_FLOCK)
1313		cifs_dbg(FYI, "Flock\n");
1314	if (flock->fl_flags & FL_SLEEP) {
1315		cifs_dbg(FYI, "Blocking lock\n");
1316		*wait_flag = true;
1317	}
1318	if (flock->fl_flags & FL_ACCESS)
1319		cifs_dbg(FYI, "Process suspended by mandatory locking - not implemented yet\n");
1320	if (flock->fl_flags & FL_LEASE)
1321		cifs_dbg(FYI, "Lease on file - not implemented yet\n");
1322	if (flock->fl_flags &
1323	    (~(FL_POSIX | FL_FLOCK | FL_SLEEP |
1324	       FL_ACCESS | FL_LEASE | FL_CLOSE)))
1325		cifs_dbg(FYI, "Unknown lock flags 0x%x\n", flock->fl_flags);
1326
1327	*type = server->vals->large_lock_type;
1328	if (flock->fl_type == F_WRLCK) {
1329		cifs_dbg(FYI, "F_WRLCK\n");
1330		*type |= server->vals->exclusive_lock_type;
1331		*lock = 1;
1332	} else if (flock->fl_type == F_UNLCK) {
1333		cifs_dbg(FYI, "F_UNLCK\n");
1334		*type |= server->vals->unlock_lock_type;
1335		*unlock = 1;
1336		/* Check if unlock includes more than one lock range */
1337	} else if (flock->fl_type == F_RDLCK) {
1338		cifs_dbg(FYI, "F_RDLCK\n");
1339		*type |= server->vals->shared_lock_type;
1340		*lock = 1;
1341	} else if (flock->fl_type == F_EXLCK) {
1342		cifs_dbg(FYI, "F_EXLCK\n");
1343		*type |= server->vals->exclusive_lock_type;
1344		*lock = 1;
1345	} else if (flock->fl_type == F_SHLCK) {
1346		cifs_dbg(FYI, "F_SHLCK\n");
1347		*type |= server->vals->shared_lock_type;
1348		*lock = 1;
1349	} else
1350		cifs_dbg(FYI, "Unknown type of lock\n");
1351}
1352
1353static int
1354cifs_getlk(struct file *file, struct file_lock *flock, __u32 type,
1355	   bool wait_flag, bool posix_lck, unsigned int xid)
1356{
1357	int rc = 0;
1358	__u64 length = 1 + flock->fl_end - flock->fl_start;
1359	struct cifsFileInfo *cfile = (struct cifsFileInfo *)file->private_data;
1360	struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1361	struct TCP_Server_Info *server = tcon->ses->server;
1362	__u16 netfid = cfile->fid.netfid;
1363
1364	if (posix_lck) {
1365		int posix_lock_type;
1366
1367		rc = cifs_posix_lock_test(file, flock);
1368		if (!rc)
1369			return rc;
1370
1371		if (type & server->vals->shared_lock_type)
1372			posix_lock_type = CIFS_RDLCK;
1373		else
1374			posix_lock_type = CIFS_WRLCK;
1375		rc = CIFSSMBPosixLock(xid, tcon, netfid,
1376				      hash_lockowner(flock->fl_owner),
1377				      flock->fl_start, length, flock,
1378				      posix_lock_type, wait_flag);
1379		return rc;
1380	}
1381
1382	rc = cifs_lock_test(cfile, flock->fl_start, length, type, flock);
1383	if (!rc)
1384		return rc;
1385
1386	/* BB we could chain these into one lock request BB */
1387	rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length, type,
1388				    1, 0, false);
1389	if (rc == 0) {
1390		rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length,
1391					    type, 0, 1, false);
1392		flock->fl_type = F_UNLCK;
1393		if (rc != 0)
1394			cifs_dbg(VFS, "Error unlocking previously locked range %d during test of lock\n",
1395				 rc);
1396		return 0;
1397	}
1398
1399	if (type & server->vals->shared_lock_type) {
1400		flock->fl_type = F_WRLCK;
1401		return 0;
1402	}
1403
1404	type &= ~server->vals->exclusive_lock_type;
1405
1406	rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length,
1407				    type | server->vals->shared_lock_type,
1408				    1, 0, false);
1409	if (rc == 0) {
1410		rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length,
1411			type | server->vals->shared_lock_type, 0, 1, false);
1412		flock->fl_type = F_RDLCK;
1413		if (rc != 0)
1414			cifs_dbg(VFS, "Error unlocking previously locked range %d during test of lock\n",
1415				 rc);
1416	} else
1417		flock->fl_type = F_WRLCK;
1418
1419	return 0;
1420}
1421
1422void
1423cifs_move_llist(struct list_head *source, struct list_head *dest)
1424{
1425	struct list_head *li, *tmp;
1426	list_for_each_safe(li, tmp, source)
1427		list_move(li, dest);
1428}
1429
1430void
1431cifs_free_llist(struct list_head *llist)
1432{
1433	struct cifsLockInfo *li, *tmp;
1434	list_for_each_entry_safe(li, tmp, llist, llist) {
1435		cifs_del_lock_waiters(li);
1436		list_del(&li->llist);
1437		kfree(li);
1438	}
1439}
1440
1441int
1442cifs_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock,
1443		  unsigned int xid)
1444{
1445	int rc = 0, stored_rc;
1446	static const int types[] = {
1447		LOCKING_ANDX_LARGE_FILES,
1448		LOCKING_ANDX_SHARED_LOCK | LOCKING_ANDX_LARGE_FILES
1449	};
1450	unsigned int i;
1451	unsigned int max_num, num, max_buf;
1452	LOCKING_ANDX_RANGE *buf, *cur;
1453	struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1454	struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
1455	struct cifsLockInfo *li, *tmp;
1456	__u64 length = 1 + flock->fl_end - flock->fl_start;
1457	struct list_head tmp_llist;
1458
1459	INIT_LIST_HEAD(&tmp_llist);
1460
1461	/*
1462	 * Accessing maxBuf is racy with cifs_reconnect - need to store value
1463	 * and check it for zero before using.
1464	 */
1465	max_buf = tcon->ses->server->maxBuf;
1466	if (!max_buf)
1467		return -EINVAL;
1468
1469	max_num = (max_buf - sizeof(struct smb_hdr)) /
1470						sizeof(LOCKING_ANDX_RANGE);
1471	buf = kcalloc(max_num, sizeof(LOCKING_ANDX_RANGE), GFP_KERNEL);
1472	if (!buf)
1473		return -ENOMEM;
1474
1475	down_write(&cinode->lock_sem);
1476	for (i = 0; i < 2; i++) {
1477		cur = buf;
1478		num = 0;
1479		list_for_each_entry_safe(li, tmp, &cfile->llist->locks, llist) {
1480			if (flock->fl_start > li->offset ||
1481			    (flock->fl_start + length) <
1482			    (li->offset + li->length))
1483				continue;
1484			if (current->tgid != li->pid)
1485				continue;
1486			if (types[i] != li->type)
1487				continue;
1488			if (cinode->can_cache_brlcks) {
1489				/*
1490				 * We can cache brlock requests - simply remove
1491				 * a lock from the file's list.
1492				 */
1493				list_del(&li->llist);
1494				cifs_del_lock_waiters(li);
1495				kfree(li);
1496				continue;
1497			}
1498			cur->Pid = cpu_to_le16(li->pid);
1499			cur->LengthLow = cpu_to_le32((u32)li->length);
1500			cur->LengthHigh = cpu_to_le32((u32)(li->length>>32));
1501			cur->OffsetLow = cpu_to_le32((u32)li->offset);
1502			cur->OffsetHigh = cpu_to_le32((u32)(li->offset>>32));
1503			/*
1504			 * We need to save a lock here to let us add it again to
1505			 * the file's list if the unlock range request fails on
1506			 * the server.
1507			 */
1508			list_move(&li->llist, &tmp_llist);
1509			if (++num == max_num) {
1510				stored_rc = cifs_lockv(xid, tcon,
1511						       cfile->fid.netfid,
1512						       li->type, num, 0, buf);
1513				if (stored_rc) {
1514					/*
1515					 * We failed on the unlock range
1516					 * request - add all locks from the tmp
1517					 * list to the head of the file's list.
1518					 */
1519					cifs_move_llist(&tmp_llist,
1520							&cfile->llist->locks);
1521					rc = stored_rc;
1522				} else
1523					/*
1524					 * The unlock range request succeed -
1525					 * free the tmp list.
1526					 */
1527					cifs_free_llist(&tmp_llist);
1528				cur = buf;
1529				num = 0;
1530			} else
1531				cur++;
1532		}
1533		if (num) {
1534			stored_rc = cifs_lockv(xid, tcon, cfile->fid.netfid,
1535					       types[i], num, 0, buf);
1536			if (stored_rc) {
1537				cifs_move_llist(&tmp_llist,
1538						&cfile->llist->locks);
1539				rc = stored_rc;
1540			} else
1541				cifs_free_llist(&tmp_llist);
1542		}
1543	}
1544
1545	up_write(&cinode->lock_sem);
1546	kfree(buf);
1547	return rc;
1548}
1549
1550static int
1551cifs_setlk(struct file *file, struct file_lock *flock, __u32 type,
1552	   bool wait_flag, bool posix_lck, int lock, int unlock,
1553	   unsigned int xid)
1554{
1555	int rc = 0;
1556	__u64 length = 1 + flock->fl_end - flock->fl_start;
1557	struct cifsFileInfo *cfile = (struct cifsFileInfo *)file->private_data;
1558	struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1559	struct TCP_Server_Info *server = tcon->ses->server;
1560	struct inode *inode = d_inode(cfile->dentry);
1561
1562	if (posix_lck) {
1563		int posix_lock_type;
1564
1565		rc = cifs_posix_lock_set(file, flock);
1566		if (!rc || rc < 0)
1567			return rc;
1568
1569		if (type & server->vals->shared_lock_type)
1570			posix_lock_type = CIFS_RDLCK;
1571		else
1572			posix_lock_type = CIFS_WRLCK;
1573
1574		if (unlock == 1)
1575			posix_lock_type = CIFS_UNLCK;
1576
1577		rc = CIFSSMBPosixLock(xid, tcon, cfile->fid.netfid,
1578				      hash_lockowner(flock->fl_owner),
1579				      flock->fl_start, length,
1580				      NULL, posix_lock_type, wait_flag);
1581		goto out;
1582	}
1583
1584	if (lock) {
1585		struct cifsLockInfo *lock;
 
 
 
 
 
 
 
 
 
 
 
 
 
1586
1587		lock = cifs_lock_init(flock->fl_start, length, type);
1588		if (!lock)
1589			return -ENOMEM;
1590
1591		rc = cifs_lock_add_if(cfile, lock, wait_flag);
1592		if (rc < 0) {
1593			kfree(lock);
1594			return rc;
1595		}
1596		if (!rc)
1597			goto out;
1598
1599		/*
1600		 * Windows 7 server can delay breaking lease from read to None
1601		 * if we set a byte-range lock on a file - break it explicitly
1602		 * before sending the lock to the server to be sure the next
1603		 * read won't conflict with non-overlapted locks due to
1604		 * pagereading.
1605		 */
1606		if (!CIFS_CACHE_WRITE(CIFS_I(inode)) &&
1607					CIFS_CACHE_READ(CIFS_I(inode))) {
1608			cifs_zap_mapping(inode);
1609			cifs_dbg(FYI, "Set no oplock for inode=%p due to mand locks\n",
1610				 inode);
1611			CIFS_I(inode)->oplock = 0;
1612		}
1613
1614		rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length,
1615					    type, 1, 0, wait_flag);
1616		if (rc) {
1617			kfree(lock);
1618			return rc;
1619		}
1620
1621		cifs_lock_add(cfile, lock);
1622	} else if (unlock)
1623		rc = server->ops->mand_unlock_range(cfile, flock, xid);
1624
1625out:
1626	if (flock->fl_flags & FL_POSIX && !rc)
1627		rc = locks_lock_file_wait(file, flock);
1628	return rc;
1629}
1630
1631int cifs_lock(struct file *file, int cmd, struct file_lock *flock)
1632{
1633	int rc, xid;
1634	int lock = 0, unlock = 0;
1635	bool wait_flag = false;
1636	bool posix_lck = false;
1637	struct cifs_sb_info *cifs_sb;
1638	struct cifs_tcon *tcon;
1639	struct cifsInodeInfo *cinode;
1640	struct cifsFileInfo *cfile;
1641	__u16 netfid;
1642	__u32 type;
1643
1644	rc = -EACCES;
1645	xid = get_xid();
1646
1647	cifs_dbg(FYI, "Lock parm: 0x%x flockflags: 0x%x flocktype: 0x%x start: %lld end: %lld\n",
1648		 cmd, flock->fl_flags, flock->fl_type,
1649		 flock->fl_start, flock->fl_end);
1650
1651	cfile = (struct cifsFileInfo *)file->private_data;
1652	tcon = tlink_tcon(cfile->tlink);
1653
1654	cifs_read_flock(flock, &type, &lock, &unlock, &wait_flag,
1655			tcon->ses->server);
1656
1657	cifs_sb = CIFS_FILE_SB(file);
1658	netfid = cfile->fid.netfid;
1659	cinode = CIFS_I(file_inode(file));
1660
1661	if (cap_unix(tcon->ses) &&
1662	    (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
1663	    ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
1664		posix_lck = true;
1665	/*
1666	 * BB add code here to normalize offset and length to account for
1667	 * negative length which we can not accept over the wire.
1668	 */
1669	if (IS_GETLK(cmd)) {
1670		rc = cifs_getlk(file, flock, type, wait_flag, posix_lck, xid);
1671		free_xid(xid);
1672		return rc;
1673	}
1674
1675	if (!lock && !unlock) {
1676		/*
1677		 * if no lock or unlock then nothing to do since we do not
1678		 * know what it is
1679		 */
1680		free_xid(xid);
1681		return -EOPNOTSUPP;
1682	}
1683
1684	rc = cifs_setlk(file, flock, type, wait_flag, posix_lck, lock, unlock,
1685			xid);
1686	free_xid(xid);
1687	return rc;
1688}
1689
1690/*
1691 * update the file size (if needed) after a write. Should be called with
1692 * the inode->i_lock held
1693 */
1694void
1695cifs_update_eof(struct cifsInodeInfo *cifsi, loff_t offset,
1696		      unsigned int bytes_written)
1697{
1698	loff_t end_of_write = offset + bytes_written;
1699
1700	if (end_of_write > cifsi->server_eof)
1701		cifsi->server_eof = end_of_write;
1702}
1703
1704static ssize_t
1705cifs_write(struct cifsFileInfo *open_file, __u32 pid, const char *write_data,
1706	   size_t write_size, loff_t *offset)
1707{
1708	int rc = 0;
1709	unsigned int bytes_written = 0;
1710	unsigned int total_written;
1711	struct cifs_sb_info *cifs_sb;
1712	struct cifs_tcon *tcon;
1713	struct TCP_Server_Info *server;
1714	unsigned int xid;
1715	struct dentry *dentry = open_file->dentry;
1716	struct cifsInodeInfo *cifsi = CIFS_I(d_inode(dentry));
1717	struct cifs_io_parms io_parms;
1718
1719	cifs_sb = CIFS_SB(dentry->d_sb);
1720
1721	cifs_dbg(FYI, "write %zd bytes to offset %lld of %pd\n",
1722		 write_size, *offset, dentry);
1723
1724	tcon = tlink_tcon(open_file->tlink);
1725	server = tcon->ses->server;
1726
1727	if (!server->ops->sync_write)
1728		return -ENOSYS;
1729
1730	xid = get_xid();
1731
1732	for (total_written = 0; write_size > total_written;
1733	     total_written += bytes_written) {
1734		rc = -EAGAIN;
1735		while (rc == -EAGAIN) {
1736			struct kvec iov[2];
1737			unsigned int len;
1738
1739			if (open_file->invalidHandle) {
1740				/* we could deadlock if we called
1741				   filemap_fdatawait from here so tell
1742				   reopen_file not to flush data to
1743				   server now */
1744				rc = cifs_reopen_file(open_file, false);
1745				if (rc != 0)
1746					break;
1747			}
1748
1749			len = min(server->ops->wp_retry_size(d_inode(dentry)),
1750				  (unsigned int)write_size - total_written);
1751			/* iov[0] is reserved for smb header */
1752			iov[1].iov_base = (char *)write_data + total_written;
1753			iov[1].iov_len = len;
 
1754			io_parms.pid = pid;
1755			io_parms.tcon = tcon;
1756			io_parms.offset = *offset;
1757			io_parms.length = len;
1758			rc = server->ops->sync_write(xid, &open_file->fid,
1759					&io_parms, &bytes_written, iov, 1);
1760		}
1761		if (rc || (bytes_written == 0)) {
1762			if (total_written)
1763				break;
1764			else {
1765				free_xid(xid);
1766				return rc;
1767			}
1768		} else {
1769			spin_lock(&d_inode(dentry)->i_lock);
1770			cifs_update_eof(cifsi, *offset, bytes_written);
1771			spin_unlock(&d_inode(dentry)->i_lock);
1772			*offset += bytes_written;
1773		}
1774	}
1775
1776	cifs_stats_bytes_written(tcon, total_written);
1777
1778	if (total_written > 0) {
1779		spin_lock(&d_inode(dentry)->i_lock);
1780		if (*offset > d_inode(dentry)->i_size)
1781			i_size_write(d_inode(dentry), *offset);
1782		spin_unlock(&d_inode(dentry)->i_lock);
1783	}
1784	mark_inode_dirty_sync(d_inode(dentry));
1785	free_xid(xid);
1786	return total_written;
1787}
1788
1789struct cifsFileInfo *find_readable_file(struct cifsInodeInfo *cifs_inode,
1790					bool fsuid_only)
1791{
1792	struct cifsFileInfo *open_file = NULL;
1793	struct cifs_sb_info *cifs_sb = CIFS_SB(cifs_inode->vfs_inode.i_sb);
1794	struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
1795
1796	/* only filter by fsuid on multiuser mounts */
1797	if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
1798		fsuid_only = false;
1799
1800	spin_lock(&tcon->open_file_lock);
1801	/* we could simply get the first_list_entry since write-only entries
1802	   are always at the end of the list but since the first entry might
1803	   have a close pending, we go through the whole list */
1804	list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
1805		if (fsuid_only && !uid_eq(open_file->uid, current_fsuid()))
1806			continue;
1807		if (OPEN_FMODE(open_file->f_flags) & FMODE_READ) {
1808			if (!open_file->invalidHandle) {
1809				/* found a good file */
1810				/* lock it so it will not be closed on us */
1811				cifsFileInfo_get(open_file);
1812				spin_unlock(&tcon->open_file_lock);
1813				return open_file;
1814			} /* else might as well continue, and look for
1815			     another, or simply have the caller reopen it
1816			     again rather than trying to fix this handle */
1817		} else /* write only file */
1818			break; /* write only files are last so must be done */
1819	}
1820	spin_unlock(&tcon->open_file_lock);
1821	return NULL;
1822}
1823
1824struct cifsFileInfo *find_writable_file(struct cifsInodeInfo *cifs_inode,
1825					bool fsuid_only)
1826{
1827	struct cifsFileInfo *open_file, *inv_file = NULL;
1828	struct cifs_sb_info *cifs_sb;
1829	struct cifs_tcon *tcon;
1830	bool any_available = false;
1831	int rc;
1832	unsigned int refind = 0;
1833
1834	/* Having a null inode here (because mapping->host was set to zero by
1835	the VFS or MM) should not happen but we had reports of on oops (due to
1836	it being zero) during stress testcases so we need to check for it */
1837
1838	if (cifs_inode == NULL) {
1839		cifs_dbg(VFS, "Null inode passed to cifs_writeable_file\n");
1840		dump_stack();
1841		return NULL;
1842	}
1843
1844	cifs_sb = CIFS_SB(cifs_inode->vfs_inode.i_sb);
1845	tcon = cifs_sb_master_tcon(cifs_sb);
1846
1847	/* only filter by fsuid on multiuser mounts */
1848	if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
1849		fsuid_only = false;
1850
1851	spin_lock(&tcon->open_file_lock);
1852refind_writable:
1853	if (refind > MAX_REOPEN_ATT) {
1854		spin_unlock(&tcon->open_file_lock);
1855		return NULL;
1856	}
1857	list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
1858		if (!any_available && open_file->pid != current->tgid)
1859			continue;
1860		if (fsuid_only && !uid_eq(open_file->uid, current_fsuid()))
1861			continue;
1862		if (OPEN_FMODE(open_file->f_flags) & FMODE_WRITE) {
 
 
1863			if (!open_file->invalidHandle) {
1864				/* found a good writable file */
1865				cifsFileInfo_get(open_file);
1866				spin_unlock(&tcon->open_file_lock);
1867				return open_file;
1868			} else {
1869				if (!inv_file)
1870					inv_file = open_file;
1871			}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1872		}
1873	}
1874	/* couldn't find useable FH with same pid, try any available */
1875	if (!any_available) {
1876		any_available = true;
1877		goto refind_writable;
1878	}
1879
1880	if (inv_file) {
1881		any_available = false;
1882		cifsFileInfo_get(inv_file);
1883	}
1884
1885	spin_unlock(&tcon->open_file_lock);
1886
1887	if (inv_file) {
1888		rc = cifs_reopen_file(inv_file, false);
1889		if (!rc)
1890			return inv_file;
1891		else {
1892			spin_lock(&tcon->open_file_lock);
1893			list_move_tail(&inv_file->flist,
1894					&cifs_inode->openFileList);
1895			spin_unlock(&tcon->open_file_lock);
1896			cifsFileInfo_put(inv_file);
1897			++refind;
1898			inv_file = NULL;
1899			spin_lock(&tcon->open_file_lock);
1900			goto refind_writable;
1901		}
1902	}
1903
1904	return NULL;
1905}
1906
1907static int cifs_partialpagewrite(struct page *page, unsigned from, unsigned to)
1908{
1909	struct address_space *mapping = page->mapping;
1910	loff_t offset = (loff_t)page->index << PAGE_SHIFT;
1911	char *write_data;
1912	int rc = -EFAULT;
1913	int bytes_written = 0;
1914	struct inode *inode;
1915	struct cifsFileInfo *open_file;
1916
1917	if (!mapping || !mapping->host)
1918		return -EFAULT;
1919
1920	inode = page->mapping->host;
1921
1922	offset += (loff_t)from;
1923	write_data = kmap(page);
1924	write_data += from;
1925
1926	if ((to > PAGE_SIZE) || (from > to)) {
1927		kunmap(page);
1928		return -EIO;
1929	}
1930
1931	/* racing with truncate? */
1932	if (offset > mapping->host->i_size) {
1933		kunmap(page);
1934		return 0; /* don't care */
1935	}
1936
1937	/* check to make sure that we are not extending the file */
1938	if (mapping->host->i_size - offset < (loff_t)to)
1939		to = (unsigned)(mapping->host->i_size - offset);
1940
1941	open_file = find_writable_file(CIFS_I(mapping->host), false);
1942	if (open_file) {
1943		bytes_written = cifs_write(open_file, open_file->pid,
1944					   write_data, to - from, &offset);
1945		cifsFileInfo_put(open_file);
1946		/* Does mm or vfs already set times? */
1947		inode->i_atime = inode->i_mtime = current_time(inode);
1948		if ((bytes_written > 0) && (offset))
1949			rc = 0;
1950		else if (bytes_written < 0)
1951			rc = bytes_written;
1952	} else {
1953		cifs_dbg(FYI, "No writeable filehandles for inode\n");
1954		rc = -EIO;
1955	}
1956
1957	kunmap(page);
1958	return rc;
1959}
1960
1961static struct cifs_writedata *
1962wdata_alloc_and_fillpages(pgoff_t tofind, struct address_space *mapping,
1963			  pgoff_t end, pgoff_t *index,
1964			  unsigned int *found_pages)
1965{
1966	struct cifs_writedata *wdata;
1967
1968	wdata = cifs_writedata_alloc((unsigned int)tofind,
1969				     cifs_writev_complete);
1970	if (!wdata)
1971		return NULL;
1972
1973	*found_pages = find_get_pages_range_tag(mapping, index, end,
1974				PAGECACHE_TAG_DIRTY, tofind, wdata->pages);
1975	return wdata;
1976}
1977
1978static unsigned int
1979wdata_prepare_pages(struct cifs_writedata *wdata, unsigned int found_pages,
1980		    struct address_space *mapping,
1981		    struct writeback_control *wbc,
1982		    pgoff_t end, pgoff_t *index, pgoff_t *next, bool *done)
1983{
1984	unsigned int nr_pages = 0, i;
1985	struct page *page;
1986
1987	for (i = 0; i < found_pages; i++) {
1988		page = wdata->pages[i];
1989		/*
1990		 * At this point we hold neither the i_pages lock nor the
1991		 * page lock: the page may be truncated or invalidated
1992		 * (changing page->mapping to NULL), or even swizzled
1993		 * back from swapper_space to tmpfs file mapping
1994		 */
1995
1996		if (nr_pages == 0)
1997			lock_page(page);
1998		else if (!trylock_page(page))
1999			break;
2000
2001		if (unlikely(page->mapping != mapping)) {
2002			unlock_page(page);
2003			break;
2004		}
2005
2006		if (!wbc->range_cyclic && page->index > end) {
2007			*done = true;
2008			unlock_page(page);
2009			break;
2010		}
2011
2012		if (*next && (page->index != *next)) {
2013			/* Not next consecutive page */
2014			unlock_page(page);
2015			break;
2016		}
2017
2018		if (wbc->sync_mode != WB_SYNC_NONE)
2019			wait_on_page_writeback(page);
2020
2021		if (PageWriteback(page) ||
2022				!clear_page_dirty_for_io(page)) {
2023			unlock_page(page);
2024			break;
2025		}
2026
2027		/*
2028		 * This actually clears the dirty bit in the radix tree.
2029		 * See cifs_writepage() for more commentary.
2030		 */
2031		set_page_writeback(page);
2032		if (page_offset(page) >= i_size_read(mapping->host)) {
2033			*done = true;
2034			unlock_page(page);
2035			end_page_writeback(page);
2036			break;
2037		}
2038
2039		wdata->pages[i] = page;
2040		*next = page->index + 1;
2041		++nr_pages;
2042	}
2043
2044	/* reset index to refind any pages skipped */
2045	if (nr_pages == 0)
2046		*index = wdata->pages[0]->index + 1;
2047
2048	/* put any pages we aren't going to use */
2049	for (i = nr_pages; i < found_pages; i++) {
2050		put_page(wdata->pages[i]);
2051		wdata->pages[i] = NULL;
2052	}
2053
2054	return nr_pages;
2055}
2056
2057static int
2058wdata_send_pages(struct cifs_writedata *wdata, unsigned int nr_pages,
2059		 struct address_space *mapping, struct writeback_control *wbc)
2060{
2061	int rc = 0;
2062	struct TCP_Server_Info *server;
2063	unsigned int i;
2064
2065	wdata->sync_mode = wbc->sync_mode;
2066	wdata->nr_pages = nr_pages;
2067	wdata->offset = page_offset(wdata->pages[0]);
2068	wdata->pagesz = PAGE_SIZE;
2069	wdata->tailsz = min(i_size_read(mapping->host) -
2070			page_offset(wdata->pages[nr_pages - 1]),
2071			(loff_t)PAGE_SIZE);
2072	wdata->bytes = ((nr_pages - 1) * PAGE_SIZE) + wdata->tailsz;
2073
2074	if (wdata->cfile != NULL)
2075		cifsFileInfo_put(wdata->cfile);
2076	wdata->cfile = find_writable_file(CIFS_I(mapping->host), false);
2077	if (!wdata->cfile) {
2078		cifs_dbg(VFS, "No writable handles for inode\n");
2079		rc = -EBADF;
2080	} else {
2081		wdata->pid = wdata->cfile->pid;
2082		server = tlink_tcon(wdata->cfile->tlink)->ses->server;
2083		rc = server->ops->async_writev(wdata, cifs_writedata_release);
2084	}
2085
2086	for (i = 0; i < nr_pages; ++i)
2087		unlock_page(wdata->pages[i]);
2088
2089	return rc;
2090}
2091
2092static int cifs_writepages(struct address_space *mapping,
2093			   struct writeback_control *wbc)
2094{
2095	struct cifs_sb_info *cifs_sb = CIFS_SB(mapping->host->i_sb);
2096	struct TCP_Server_Info *server;
2097	bool done = false, scanned = false, range_whole = false;
2098	pgoff_t end, index;
2099	struct cifs_writedata *wdata;
 
2100	int rc = 0;
2101
2102	/*
2103	 * If wsize is smaller than the page cache size, default to writing
2104	 * one page at a time via cifs_writepage
2105	 */
2106	if (cifs_sb->wsize < PAGE_SIZE)
2107		return generic_writepages(mapping, wbc);
2108
2109	if (wbc->range_cyclic) {
2110		index = mapping->writeback_index; /* Start from prev offset */
2111		end = -1;
2112	} else {
2113		index = wbc->range_start >> PAGE_SHIFT;
2114		end = wbc->range_end >> PAGE_SHIFT;
2115		if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
2116			range_whole = true;
2117		scanned = true;
2118	}
2119	server = cifs_sb_master_tcon(cifs_sb)->ses->server;
2120retry:
2121	while (!done && index <= end) {
2122		unsigned int i, nr_pages, found_pages, wsize, credits;
2123		pgoff_t next = 0, tofind, saved_index = index;
 
2124
2125		rc = server->ops->wait_mtu_credits(server, cifs_sb->wsize,
2126						   &wsize, &credits);
2127		if (rc)
2128			break;
2129
2130		tofind = min((wsize / PAGE_SIZE) - 1, end - index) + 1;
2131
2132		wdata = wdata_alloc_and_fillpages(tofind, mapping, end, &index,
2133						  &found_pages);
2134		if (!wdata) {
2135			rc = -ENOMEM;
2136			add_credits_and_wake_if(server, credits, 0);
2137			break;
2138		}
2139
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2140		if (found_pages == 0) {
2141			kref_put(&wdata->refcount, cifs_writedata_release);
2142			add_credits_and_wake_if(server, credits, 0);
2143			break;
2144		}
2145
2146		nr_pages = wdata_prepare_pages(wdata, found_pages, mapping, wbc,
2147					       end, &index, &next, &done);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2148
2149		/* nothing to write? */
2150		if (nr_pages == 0) {
2151			kref_put(&wdata->refcount, cifs_writedata_release);
2152			add_credits_and_wake_if(server, credits, 0);
2153			continue;
2154		}
2155
2156		wdata->credits = credits;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2157
2158		rc = wdata_send_pages(wdata, nr_pages, mapping, wbc);
 
2159
2160		/* send failure -- clean up the mess */
2161		if (rc != 0) {
2162			add_credits_and_wake_if(server, wdata->credits, 0);
2163			for (i = 0; i < nr_pages; ++i) {
2164				if (rc == -EAGAIN)
2165					redirty_page_for_writepage(wbc,
2166							   wdata->pages[i]);
2167				else
2168					SetPageError(wdata->pages[i]);
2169				end_page_writeback(wdata->pages[i]);
2170				put_page(wdata->pages[i]);
2171			}
2172			if (rc != -EAGAIN)
2173				mapping_set_error(mapping, rc);
2174		}
2175		kref_put(&wdata->refcount, cifs_writedata_release);
2176
2177		if (wbc->sync_mode == WB_SYNC_ALL && rc == -EAGAIN) {
2178			index = saved_index;
2179			continue;
2180		}
2181
2182		wbc->nr_to_write -= nr_pages;
2183		if (wbc->nr_to_write <= 0)
2184			done = true;
2185
2186		index = next;
2187	}
2188
2189	if (!scanned && !done) {
2190		/*
2191		 * We hit the last page and there is more work to be done: wrap
2192		 * back to the start of the file
2193		 */
2194		scanned = true;
2195		index = 0;
2196		goto retry;
2197	}
2198
2199	if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
2200		mapping->writeback_index = index;
2201
2202	return rc;
2203}
2204
2205static int
2206cifs_writepage_locked(struct page *page, struct writeback_control *wbc)
2207{
2208	int rc;
2209	unsigned int xid;
2210
2211	xid = get_xid();
2212/* BB add check for wbc flags */
2213	get_page(page);
2214	if (!PageUptodate(page))
2215		cifs_dbg(FYI, "ppw - page not up to date\n");
2216
2217	/*
2218	 * Set the "writeback" flag, and clear "dirty" in the radix tree.
2219	 *
2220	 * A writepage() implementation always needs to do either this,
2221	 * or re-dirty the page with "redirty_page_for_writepage()" in
2222	 * the case of a failure.
2223	 *
2224	 * Just unlocking the page will cause the radix tree tag-bits
2225	 * to fail to update with the state of the page correctly.
2226	 */
2227	set_page_writeback(page);
2228retry_write:
2229	rc = cifs_partialpagewrite(page, 0, PAGE_SIZE);
2230	if (rc == -EAGAIN) {
2231		if (wbc->sync_mode == WB_SYNC_ALL)
2232			goto retry_write;
2233		redirty_page_for_writepage(wbc, page);
2234	} else if (rc != 0) {
2235		SetPageError(page);
2236		mapping_set_error(page->mapping, rc);
2237	} else {
2238		SetPageUptodate(page);
2239	}
2240	end_page_writeback(page);
2241	put_page(page);
2242	free_xid(xid);
2243	return rc;
2244}
2245
2246static int cifs_writepage(struct page *page, struct writeback_control *wbc)
2247{
2248	int rc = cifs_writepage_locked(page, wbc);
2249	unlock_page(page);
2250	return rc;
2251}
2252
2253static int cifs_write_end(struct file *file, struct address_space *mapping,
2254			loff_t pos, unsigned len, unsigned copied,
2255			struct page *page, void *fsdata)
2256{
2257	int rc;
2258	struct inode *inode = mapping->host;
2259	struct cifsFileInfo *cfile = file->private_data;
2260	struct cifs_sb_info *cifs_sb = CIFS_SB(cfile->dentry->d_sb);
2261	__u32 pid;
2262
2263	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
2264		pid = cfile->pid;
2265	else
2266		pid = current->tgid;
2267
2268	cifs_dbg(FYI, "write_end for page %p from pos %lld with %d bytes\n",
2269		 page, pos, copied);
2270
2271	if (PageChecked(page)) {
2272		if (copied == len)
2273			SetPageUptodate(page);
2274		ClearPageChecked(page);
2275	} else if (!PageUptodate(page) && copied == PAGE_SIZE)
2276		SetPageUptodate(page);
2277
2278	if (!PageUptodate(page)) {
2279		char *page_data;
2280		unsigned offset = pos & (PAGE_SIZE - 1);
2281		unsigned int xid;
2282
2283		xid = get_xid();
2284		/* this is probably better than directly calling
2285		   partialpage_write since in this function the file handle is
2286		   known which we might as well	leverage */
2287		/* BB check if anything else missing out of ppw
2288		   such as updating last write time */
2289		page_data = kmap(page);
2290		rc = cifs_write(cfile, pid, page_data + offset, copied, &pos);
2291		/* if (rc < 0) should we set writebehind rc? */
2292		kunmap(page);
2293
2294		free_xid(xid);
2295	} else {
2296		rc = copied;
2297		pos += copied;
2298		set_page_dirty(page);
2299	}
2300
2301	if (rc > 0) {
2302		spin_lock(&inode->i_lock);
2303		if (pos > inode->i_size)
2304			i_size_write(inode, pos);
2305		spin_unlock(&inode->i_lock);
2306	}
2307
2308	unlock_page(page);
2309	put_page(page);
2310
2311	return rc;
2312}
2313
2314int cifs_strict_fsync(struct file *file, loff_t start, loff_t end,
2315		      int datasync)
2316{
2317	unsigned int xid;
2318	int rc = 0;
2319	struct cifs_tcon *tcon;
2320	struct TCP_Server_Info *server;
2321	struct cifsFileInfo *smbfile = file->private_data;
2322	struct inode *inode = file_inode(file);
2323	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
2324
2325	rc = file_write_and_wait_range(file, start, end);
2326	if (rc)
2327		return rc;
2328	inode_lock(inode);
2329
2330	xid = get_xid();
2331
2332	cifs_dbg(FYI, "Sync file - name: %pD datasync: 0x%x\n",
2333		 file, datasync);
2334
2335	if (!CIFS_CACHE_READ(CIFS_I(inode))) {
2336		rc = cifs_zap_mapping(inode);
2337		if (rc) {
2338			cifs_dbg(FYI, "rc: %d during invalidate phase\n", rc);
2339			rc = 0; /* don't care about it in fsync */
2340		}
2341	}
2342
2343	tcon = tlink_tcon(smbfile->tlink);
2344	if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC)) {
2345		server = tcon->ses->server;
2346		if (server->ops->flush)
2347			rc = server->ops->flush(xid, tcon, &smbfile->fid);
2348		else
2349			rc = -ENOSYS;
2350	}
2351
2352	free_xid(xid);
2353	inode_unlock(inode);
2354	return rc;
2355}
2356
2357int cifs_fsync(struct file *file, loff_t start, loff_t end, int datasync)
2358{
2359	unsigned int xid;
2360	int rc = 0;
2361	struct cifs_tcon *tcon;
2362	struct TCP_Server_Info *server;
2363	struct cifsFileInfo *smbfile = file->private_data;
2364	struct cifs_sb_info *cifs_sb = CIFS_FILE_SB(file);
2365	struct inode *inode = file->f_mapping->host;
2366
2367	rc = file_write_and_wait_range(file, start, end);
2368	if (rc)
2369		return rc;
2370	inode_lock(inode);
2371
2372	xid = get_xid();
2373
2374	cifs_dbg(FYI, "Sync file - name: %pD datasync: 0x%x\n",
2375		 file, datasync);
2376
2377	tcon = tlink_tcon(smbfile->tlink);
2378	if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC)) {
2379		server = tcon->ses->server;
2380		if (server->ops->flush)
2381			rc = server->ops->flush(xid, tcon, &smbfile->fid);
2382		else
2383			rc = -ENOSYS;
2384	}
2385
2386	free_xid(xid);
2387	inode_unlock(inode);
2388	return rc;
2389}
2390
2391/*
2392 * As file closes, flush all cached write data for this inode checking
2393 * for write behind errors.
2394 */
2395int cifs_flush(struct file *file, fl_owner_t id)
2396{
2397	struct inode *inode = file_inode(file);
2398	int rc = 0;
2399
2400	if (file->f_mode & FMODE_WRITE)
2401		rc = filemap_write_and_wait(inode->i_mapping);
2402
2403	cifs_dbg(FYI, "Flush inode %p file %p rc %d\n", inode, file, rc);
2404
2405	return rc;
2406}
2407
2408static int
2409cifs_write_allocate_pages(struct page **pages, unsigned long num_pages)
2410{
2411	int rc = 0;
2412	unsigned long i;
2413
2414	for (i = 0; i < num_pages; i++) {
2415		pages[i] = alloc_page(GFP_KERNEL|__GFP_HIGHMEM);
2416		if (!pages[i]) {
2417			/*
2418			 * save number of pages we have already allocated and
2419			 * return with ENOMEM error
2420			 */
2421			num_pages = i;
2422			rc = -ENOMEM;
2423			break;
2424		}
2425	}
2426
2427	if (rc) {
2428		for (i = 0; i < num_pages; i++)
2429			put_page(pages[i]);
2430	}
 
2431	return rc;
2432}
2433
2434static inline
2435size_t get_numpages(const size_t wsize, const size_t len, size_t *cur_len)
2436{
2437	size_t num_pages;
2438	size_t clen;
2439
2440	clen = min_t(const size_t, len, wsize);
2441	num_pages = DIV_ROUND_UP(clen, PAGE_SIZE);
 
 
2442
2443	if (cur_len)
2444		*cur_len = clen;
2445
2446	return num_pages;
2447}
2448
2449static void
2450cifs_uncached_writedata_release(struct kref *refcount)
 
2451{
2452	int i;
2453	struct cifs_writedata *wdata = container_of(refcount,
2454					struct cifs_writedata, refcount);
 
 
 
 
 
 
 
 
 
 
 
2455
2456	kref_put(&wdata->ctx->refcount, cifs_aio_ctx_release);
2457	for (i = 0; i < wdata->nr_pages; i++)
2458		put_page(wdata->pages[i]);
2459	cifs_writedata_release(refcount);
2460}
2461
2462static void collect_uncached_write_data(struct cifs_aio_ctx *ctx);
 
 
2463
2464static void
2465cifs_uncached_writev_complete(struct work_struct *work)
2466{
2467	struct cifs_writedata *wdata = container_of(work,
2468					struct cifs_writedata, work);
2469	struct inode *inode = d_inode(wdata->cfile->dentry);
2470	struct cifsInodeInfo *cifsi = CIFS_I(inode);
2471
2472	spin_lock(&inode->i_lock);
2473	cifs_update_eof(cifsi, wdata->offset, wdata->bytes);
2474	if (cifsi->server_eof > inode->i_size)
2475		i_size_write(inode, cifsi->server_eof);
2476	spin_unlock(&inode->i_lock);
2477
2478	complete(&wdata->done);
2479	collect_uncached_write_data(wdata->ctx);
2480	/* the below call can possibly free the last ref to aio ctx */
2481	kref_put(&wdata->refcount, cifs_uncached_writedata_release);
2482}
2483
2484static int
2485wdata_fill_from_iovec(struct cifs_writedata *wdata, struct iov_iter *from,
2486		      size_t *len, unsigned long *num_pages)
2487{
2488	size_t save_len, copied, bytes, cur_len = *len;
2489	unsigned long i, nr_pages = *num_pages;
2490
2491	save_len = cur_len;
2492	for (i = 0; i < nr_pages; i++) {
2493		bytes = min_t(const size_t, cur_len, PAGE_SIZE);
2494		copied = copy_page_from_iter(wdata->pages[i], 0, bytes, from);
2495		cur_len -= copied;
2496		/*
2497		 * If we didn't copy as much as we expected, then that
2498		 * may mean we trod into an unmapped area. Stop copying
2499		 * at that point. On the next pass through the big
2500		 * loop, we'll likely end up getting a zero-length
2501		 * write and bailing out of it.
2502		 */
2503		if (copied < bytes)
2504			break;
2505	}
2506	cur_len = save_len - cur_len;
2507	*len = cur_len;
2508
2509	/*
2510	 * If we have no data to send, then that probably means that
2511	 * the copy above failed altogether. That's most likely because
2512	 * the address in the iovec was bogus. Return -EFAULT and let
2513	 * the caller free anything we allocated and bail out.
2514	 */
2515	if (!cur_len)
2516		return -EFAULT;
2517
2518	/*
2519	 * i + 1 now represents the number of pages we actually used in
2520	 * the copy phase above.
2521	 */
2522	*num_pages = i + 1;
2523	return 0;
2524}
2525
2526static int
2527cifs_write_from_iter(loff_t offset, size_t len, struct iov_iter *from,
2528		     struct cifsFileInfo *open_file,
2529		     struct cifs_sb_info *cifs_sb, struct list_head *wdata_list,
2530		     struct cifs_aio_ctx *ctx)
2531{
2532	int rc = 0;
2533	size_t cur_len;
2534	unsigned long nr_pages, num_pages, i;
2535	struct cifs_writedata *wdata;
2536	struct iov_iter saved_from = *from;
2537	loff_t saved_offset = offset;
2538	pid_t pid;
2539	struct TCP_Server_Info *server;
2540
2541	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
2542		pid = open_file->pid;
2543	else
2544		pid = current->tgid;
2545
2546	server = tlink_tcon(open_file->tlink)->ses->server;
 
 
 
 
2547
2548	do {
2549		unsigned int wsize, credits;
2550
2551		rc = server->ops->wait_mtu_credits(server, cifs_sb->wsize,
2552						   &wsize, &credits);
2553		if (rc)
2554			break;
2555
2556		nr_pages = get_numpages(wsize, len, &cur_len);
2557		wdata = cifs_writedata_alloc(nr_pages,
2558					     cifs_uncached_writev_complete);
2559		if (!wdata) {
2560			rc = -ENOMEM;
2561			add_credits_and_wake_if(server, credits, 0);
2562			break;
2563		}
2564
2565		rc = cifs_write_allocate_pages(wdata->pages, nr_pages);
2566		if (rc) {
2567			kfree(wdata);
2568			add_credits_and_wake_if(server, credits, 0);
2569			break;
2570		}
2571
2572		num_pages = nr_pages;
2573		rc = wdata_fill_from_iovec(wdata, from, &cur_len, &num_pages);
2574		if (rc) {
2575			for (i = 0; i < nr_pages; i++)
2576				put_page(wdata->pages[i]);
2577			kfree(wdata);
2578			add_credits_and_wake_if(server, credits, 0);
2579			break;
2580		}
 
 
 
 
 
2581
2582		/*
2583		 * Bring nr_pages down to the number of pages we actually used,
2584		 * and free any pages that we didn't use.
2585		 */
2586		for ( ; nr_pages > num_pages; nr_pages--)
2587			put_page(wdata->pages[nr_pages - 1]);
2588
2589		wdata->sync_mode = WB_SYNC_ALL;
2590		wdata->nr_pages = nr_pages;
2591		wdata->offset = (__u64)offset;
2592		wdata->cfile = cifsFileInfo_get(open_file);
2593		wdata->pid = pid;
2594		wdata->bytes = cur_len;
2595		wdata->pagesz = PAGE_SIZE;
2596		wdata->tailsz = cur_len - ((nr_pages - 1) * PAGE_SIZE);
2597		wdata->credits = credits;
2598		wdata->ctx = ctx;
2599		kref_get(&ctx->refcount);
2600
2601		if (!wdata->cfile->invalidHandle ||
2602		    !(rc = cifs_reopen_file(wdata->cfile, false)))
2603			rc = server->ops->async_writev(wdata,
2604					cifs_uncached_writedata_release);
2605		if (rc) {
2606			add_credits_and_wake_if(server, wdata->credits, 0);
2607			kref_put(&wdata->refcount,
2608				 cifs_uncached_writedata_release);
2609			if (rc == -EAGAIN) {
2610				*from = saved_from;
2611				iov_iter_advance(from, offset - saved_offset);
2612				continue;
2613			}
2614			break;
2615		}
2616
2617		list_add_tail(&wdata->list, wdata_list);
2618		offset += cur_len;
2619		len -= cur_len;
2620	} while (len > 0);
2621
2622	return rc;
2623}
2624
2625static void collect_uncached_write_data(struct cifs_aio_ctx *ctx)
2626{
2627	struct cifs_writedata *wdata, *tmp;
2628	struct cifs_tcon *tcon;
2629	struct cifs_sb_info *cifs_sb;
2630	struct dentry *dentry = ctx->cfile->dentry;
2631	unsigned int i;
2632	int rc;
2633
2634	tcon = tlink_tcon(ctx->cfile->tlink);
2635	cifs_sb = CIFS_SB(dentry->d_sb);
2636
2637	mutex_lock(&ctx->aio_mutex);
2638
2639	if (list_empty(&ctx->list)) {
2640		mutex_unlock(&ctx->aio_mutex);
2641		return;
2642	}
2643
2644	rc = ctx->rc;
2645	/*
2646	 * Wait for and collect replies for any successful sends in order of
2647	 * increasing offset. Once an error is hit, then return without waiting
2648	 * for any more replies.
2649	 */
2650restart_loop:
2651	list_for_each_entry_safe(wdata, tmp, &ctx->list, list) {
2652		if (!rc) {
2653			if (!try_wait_for_completion(&wdata->done)) {
2654				mutex_unlock(&ctx->aio_mutex);
2655				return;
2656			}
2657
2658			if (wdata->result)
2659				rc = wdata->result;
2660			else
2661				ctx->total_len += wdata->bytes;
2662
2663			/* resend call if it's a retryable error */
2664			if (rc == -EAGAIN) {
2665				struct list_head tmp_list;
2666				struct iov_iter tmp_from = ctx->iter;
2667
2668				INIT_LIST_HEAD(&tmp_list);
2669				list_del_init(&wdata->list);
2670
2671				iov_iter_advance(&tmp_from,
2672						 wdata->offset - ctx->pos);
2673
2674				rc = cifs_write_from_iter(wdata->offset,
2675						wdata->bytes, &tmp_from,
2676						ctx->cfile, cifs_sb, &tmp_list,
2677						ctx);
2678
2679				list_splice(&tmp_list, &ctx->list);
2680
2681				kref_put(&wdata->refcount,
2682					 cifs_uncached_writedata_release);
2683				goto restart_loop;
2684			}
2685		}
2686		list_del_init(&wdata->list);
2687		kref_put(&wdata->refcount, cifs_uncached_writedata_release);
2688	}
2689
2690	for (i = 0; i < ctx->npages; i++)
2691		put_page(ctx->bv[i].bv_page);
2692
2693	cifs_stats_bytes_written(tcon, ctx->total_len);
2694	set_bit(CIFS_INO_INVALID_MAPPING, &CIFS_I(dentry->d_inode)->flags);
2695
2696	ctx->rc = (rc == 0) ? ctx->total_len : rc;
2697
2698	mutex_unlock(&ctx->aio_mutex);
2699
2700	if (ctx->iocb && ctx->iocb->ki_complete)
2701		ctx->iocb->ki_complete(ctx->iocb, ctx->rc, 0);
2702	else
2703		complete(&ctx->done);
2704}
2705
2706ssize_t cifs_user_writev(struct kiocb *iocb, struct iov_iter *from)
 
2707{
2708	struct file *file = iocb->ki_filp;
2709	ssize_t total_written = 0;
2710	struct cifsFileInfo *cfile;
2711	struct cifs_tcon *tcon;
2712	struct cifs_sb_info *cifs_sb;
2713	struct cifs_aio_ctx *ctx;
2714	struct iov_iter saved_from = *from;
2715	int rc;
2716
2717	/*
2718	 * BB - optimize the way when signing is disabled. We can drop this
2719	 * extra memory-to-memory copying and use iovec buffers for constructing
2720	 * write request.
2721	 */
2722
2723	rc = generic_write_checks(iocb, from);
2724	if (rc <= 0)
2725		return rc;
2726
2727	cifs_sb = CIFS_FILE_SB(file);
2728	cfile = file->private_data;
2729	tcon = tlink_tcon(cfile->tlink);
2730
2731	if (!tcon->ses->server->ops->async_writev)
2732		return -ENOSYS;
2733
2734	ctx = cifs_aio_ctx_alloc();
2735	if (!ctx)
2736		return -ENOMEM;
2737
2738	ctx->cfile = cifsFileInfo_get(cfile);
2739
2740	if (!is_sync_kiocb(iocb))
2741		ctx->iocb = iocb;
2742
2743	ctx->pos = iocb->ki_pos;
2744
2745	rc = setup_aio_ctx_iter(ctx, from, WRITE);
2746	if (rc) {
2747		kref_put(&ctx->refcount, cifs_aio_ctx_release);
2748		return rc;
2749	}
2750
2751	/* grab a lock here due to read response handlers can access ctx */
2752	mutex_lock(&ctx->aio_mutex);
2753
2754	rc = cifs_write_from_iter(iocb->ki_pos, ctx->len, &saved_from,
2755				  cfile, cifs_sb, &ctx->list, ctx);
2756
2757	/*
2758	 * If at least one write was successfully sent, then discard any rc
2759	 * value from the later writes. If the other write succeeds, then
2760	 * we'll end up returning whatever was written. If it fails, then
2761	 * we'll get a new rc value from that.
2762	 */
2763	if (!list_empty(&ctx->list))
2764		rc = 0;
2765
2766	mutex_unlock(&ctx->aio_mutex);
2767
2768	if (rc) {
2769		kref_put(&ctx->refcount, cifs_aio_ctx_release);
2770		return rc;
2771	}
2772
2773	if (!is_sync_kiocb(iocb)) {
2774		kref_put(&ctx->refcount, cifs_aio_ctx_release);
2775		return -EIOCBQUEUED;
2776	}
2777
2778	rc = wait_for_completion_killable(&ctx->done);
2779	if (rc) {
2780		mutex_lock(&ctx->aio_mutex);
2781		ctx->rc = rc = -EINTR;
2782		total_written = ctx->total_len;
2783		mutex_unlock(&ctx->aio_mutex);
2784	} else {
2785		rc = ctx->rc;
2786		total_written = ctx->total_len;
2787	}
2788
2789	kref_put(&ctx->refcount, cifs_aio_ctx_release);
2790
2791	if (unlikely(!total_written))
2792		return rc;
2793
2794	iocb->ki_pos += total_written;
2795	return total_written;
2796}
2797
2798static ssize_t
2799cifs_writev(struct kiocb *iocb, struct iov_iter *from)
2800{
2801	struct file *file = iocb->ki_filp;
2802	struct cifsFileInfo *cfile = (struct cifsFileInfo *)file->private_data;
2803	struct inode *inode = file->f_mapping->host;
2804	struct cifsInodeInfo *cinode = CIFS_I(inode);
2805	struct TCP_Server_Info *server = tlink_tcon(cfile->tlink)->ses->server;
2806	ssize_t rc;
2807
2808	inode_lock(inode);
2809	/*
2810	 * We need to hold the sem to be sure nobody modifies lock list
2811	 * with a brlock that prevents writing.
2812	 */
2813	down_read(&cinode->lock_sem);
2814
2815	rc = generic_write_checks(iocb, from);
2816	if (rc <= 0)
2817		goto out;
2818
2819	if (!cifs_find_lock_conflict(cfile, iocb->ki_pos, iov_iter_count(from),
2820				     server->vals->exclusive_lock_type, NULL,
2821				     CIFS_WRITE_OP))
2822		rc = __generic_file_write_iter(iocb, from);
2823	else
2824		rc = -EACCES;
2825out:
2826	up_read(&cinode->lock_sem);
2827	inode_unlock(inode);
2828
2829	if (rc > 0)
2830		rc = generic_write_sync(iocb, rc);
2831	return rc;
2832}
2833
2834ssize_t
2835cifs_strict_writev(struct kiocb *iocb, struct iov_iter *from)
2836{
2837	struct inode *inode = file_inode(iocb->ki_filp);
2838	struct cifsInodeInfo *cinode = CIFS_I(inode);
2839	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
2840	struct cifsFileInfo *cfile = (struct cifsFileInfo *)
2841						iocb->ki_filp->private_data;
2842	struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
2843	ssize_t written;
2844
2845	written = cifs_get_writer(cinode);
2846	if (written)
2847		return written;
2848
2849	if (CIFS_CACHE_WRITE(cinode)) {
2850		if (cap_unix(tcon->ses) &&
2851		(CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability))
2852		  && ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0)) {
2853			written = generic_file_write_iter(iocb, from);
2854			goto out;
2855		}
2856		written = cifs_writev(iocb, from);
2857		goto out;
2858	}
2859	/*
2860	 * For non-oplocked files in strict cache mode we need to write the data
2861	 * to the server exactly from the pos to pos+len-1 rather than flush all
2862	 * affected pages because it may cause a error with mandatory locks on
2863	 * these pages but not on the region from pos to ppos+len-1.
2864	 */
2865	written = cifs_user_writev(iocb, from);
2866	if (written > 0 && CIFS_CACHE_READ(cinode)) {
2867		/*
2868		 * Windows 7 server can delay breaking level2 oplock if a write
2869		 * request comes - break it on the client to prevent reading
2870		 * an old data.
2871		 */
2872		cifs_zap_mapping(inode);
2873		cifs_dbg(FYI, "Set no oplock for inode=%p after a write operation\n",
2874			 inode);
2875		cinode->oplock = 0;
2876	}
2877out:
2878	cifs_put_writer(cinode);
2879	return written;
2880}
2881
2882static struct cifs_readdata *
2883cifs_readdata_alloc(unsigned int nr_pages, work_func_t complete)
2884{
2885	struct cifs_readdata *rdata;
2886
2887	rdata = kzalloc(sizeof(*rdata) + (sizeof(struct page *) * nr_pages),
2888			GFP_KERNEL);
2889	if (rdata != NULL) {
2890		kref_init(&rdata->refcount);
2891		INIT_LIST_HEAD(&rdata->list);
2892		init_completion(&rdata->done);
2893		INIT_WORK(&rdata->work, complete);
2894	}
2895
2896	return rdata;
2897}
2898
2899void
2900cifs_readdata_release(struct kref *refcount)
 
2901{
2902	struct cifs_readdata *rdata = container_of(refcount,
2903					struct cifs_readdata, refcount);
2904#ifdef CONFIG_CIFS_SMB_DIRECT
2905	if (rdata->mr) {
2906		smbd_deregister_mr(rdata->mr);
2907		rdata->mr = NULL;
2908	}
2909#endif
2910	if (rdata->cfile)
2911		cifsFileInfo_put(rdata->cfile);
 
 
 
2912
2913	kfree(rdata);
2914}
2915
2916static int
2917cifs_read_allocate_pages(struct cifs_readdata *rdata, unsigned int nr_pages)
2918{
2919	int rc = 0;
2920	struct page *page;
2921	unsigned int i;
2922
2923	for (i = 0; i < nr_pages; i++) {
2924		page = alloc_page(GFP_KERNEL|__GFP_HIGHMEM);
2925		if (!page) {
2926			rc = -ENOMEM;
2927			break;
2928		}
2929		rdata->pages[i] = page;
2930	}
2931
2932	if (rc) {
2933		for (i = 0; i < nr_pages; i++) {
2934			put_page(rdata->pages[i]);
2935			rdata->pages[i] = NULL;
2936		}
2937	}
2938	return rc;
2939}
2940
2941static void
2942cifs_uncached_readdata_release(struct kref *refcount)
2943{
2944	struct cifs_readdata *rdata = container_of(refcount,
2945					struct cifs_readdata, refcount);
2946	unsigned int i;
2947
2948	kref_put(&rdata->ctx->refcount, cifs_aio_ctx_release);
2949	for (i = 0; i < rdata->nr_pages; i++) {
2950		put_page(rdata->pages[i]);
2951		rdata->pages[i] = NULL;
2952	}
2953	cifs_readdata_release(refcount);
2954}
2955
2956/**
2957 * cifs_readdata_to_iov - copy data from pages in response to an iovec
2958 * @rdata:	the readdata response with list of pages holding data
2959 * @iter:	destination for our data
2960 *
2961 * This function copies data from a list of pages in a readdata response into
2962 * an array of iovecs. It will first calculate where the data should go
2963 * based on the info in the readdata and then copy the data into that spot.
2964 */
2965static int
2966cifs_readdata_to_iov(struct cifs_readdata *rdata, struct iov_iter *iter)
2967{
2968	size_t remaining = rdata->got_bytes;
2969	unsigned int i;
2970
2971	for (i = 0; i < rdata->nr_pages; i++) {
2972		struct page *page = rdata->pages[i];
2973		size_t copy = min_t(size_t, remaining, PAGE_SIZE);
2974		size_t written;
2975
2976		if (unlikely(iter->type & ITER_PIPE)) {
2977			void *addr = kmap_atomic(page);
2978
2979			written = copy_to_iter(addr, copy, iter);
2980			kunmap_atomic(addr);
2981		} else
2982			written = copy_page_to_iter(page, 0, copy, iter);
2983		remaining -= written;
2984		if (written < copy && iov_iter_count(iter) > 0)
2985			break;
2986	}
2987	return remaining ? -EFAULT : 0;
2988}
2989
2990static void collect_uncached_read_data(struct cifs_aio_ctx *ctx);
2991
2992static void
2993cifs_uncached_readv_complete(struct work_struct *work)
2994{
2995	struct cifs_readdata *rdata = container_of(work,
2996						struct cifs_readdata, work);
2997
2998	complete(&rdata->done);
2999	collect_uncached_read_data(rdata->ctx);
3000	/* the below call can possibly free the last ref to aio ctx */
3001	kref_put(&rdata->refcount, cifs_uncached_readdata_release);
3002}
3003
3004static int
3005uncached_fill_pages(struct TCP_Server_Info *server,
3006		    struct cifs_readdata *rdata, struct iov_iter *iter,
3007		    unsigned int len)
3008{
3009	int result = 0;
3010	unsigned int i;
3011	unsigned int nr_pages = rdata->nr_pages;
3012
3013	rdata->got_bytes = 0;
3014	rdata->tailsz = PAGE_SIZE;
3015	for (i = 0; i < nr_pages; i++) {
3016		struct page *page = rdata->pages[i];
3017		size_t n;
3018
3019		if (len <= 0) {
3020			/* no need to hold page hostage */
3021			rdata->pages[i] = NULL;
3022			rdata->nr_pages--;
3023			put_page(page);
3024			continue;
3025		}
3026		n = len;
3027		if (len >= PAGE_SIZE) {
3028			/* enough data to fill the page */
3029			n = PAGE_SIZE;
3030			len -= n;
3031		} else {
3032			zero_user(page, len, PAGE_SIZE - len);
3033			rdata->tailsz = len;
3034			len = 0;
3035		}
3036		if (iter)
3037			result = copy_page_from_iter(page, 0, n, iter);
3038#ifdef CONFIG_CIFS_SMB_DIRECT
3039		else if (rdata->mr)
3040			result = n;
3041#endif
3042		else
3043			result = cifs_read_page_from_socket(server, page, n);
3044		if (result < 0)
3045			break;
3046
3047		rdata->got_bytes += result;
3048	}
3049
3050	return rdata->got_bytes > 0 && result != -ECONNABORTED ?
3051						rdata->got_bytes : result;
3052}
3053
3054static int
3055cifs_uncached_read_into_pages(struct TCP_Server_Info *server,
3056			      struct cifs_readdata *rdata, unsigned int len)
3057{
3058	return uncached_fill_pages(server, rdata, NULL, len);
3059}
3060
3061static int
3062cifs_uncached_copy_into_pages(struct TCP_Server_Info *server,
3063			      struct cifs_readdata *rdata,
3064			      struct iov_iter *iter)
3065{
3066	return uncached_fill_pages(server, rdata, iter, iter->count);
3067}
3068
3069static int
3070cifs_send_async_read(loff_t offset, size_t len, struct cifsFileInfo *open_file,
3071		     struct cifs_sb_info *cifs_sb, struct list_head *rdata_list,
3072		     struct cifs_aio_ctx *ctx)
3073{
3074	struct cifs_readdata *rdata;
3075	unsigned int npages, rsize, credits;
3076	size_t cur_len;
3077	int rc;
3078	pid_t pid;
3079	struct TCP_Server_Info *server;
3080
3081	server = tlink_tcon(open_file->tlink)->ses->server;
3082
3083	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
3084		pid = open_file->pid;
3085	else
3086		pid = current->tgid;
3087
3088	do {
3089		rc = server->ops->wait_mtu_credits(server, cifs_sb->rsize,
3090						   &rsize, &credits);
3091		if (rc)
3092			break;
3093
3094		cur_len = min_t(const size_t, len, rsize);
3095		npages = DIV_ROUND_UP(cur_len, PAGE_SIZE);
 
 
3096
3097		/* allocate a readdata struct */
3098		rdata = cifs_readdata_alloc(npages,
3099					    cifs_uncached_readv_complete);
3100		if (!rdata) {
3101			add_credits_and_wake_if(server, credits, 0);
3102			rc = -ENOMEM;
3103			break;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3104		}
3105
3106		rc = cifs_read_allocate_pages(rdata, npages);
3107		if (rc)
3108			goto error;
3109
3110		rdata->cfile = cifsFileInfo_get(open_file);
3111		rdata->nr_pages = npages;
3112		rdata->offset = offset;
3113		rdata->bytes = cur_len;
3114		rdata->pid = pid;
3115		rdata->pagesz = PAGE_SIZE;
3116		rdata->read_into_pages = cifs_uncached_read_into_pages;
3117		rdata->copy_into_pages = cifs_uncached_copy_into_pages;
3118		rdata->credits = credits;
3119		rdata->ctx = ctx;
3120		kref_get(&ctx->refcount);
3121
3122		if (!rdata->cfile->invalidHandle ||
3123		    !(rc = cifs_reopen_file(rdata->cfile, true)))
3124			rc = server->ops->async_readv(rdata);
3125error:
3126		if (rc) {
3127			add_credits_and_wake_if(server, rdata->credits, 0);
3128			kref_put(&rdata->refcount,
3129				 cifs_uncached_readdata_release);
3130			if (rc == -EAGAIN)
3131				continue;
3132			break;
3133		}
 
3134
3135		list_add_tail(&rdata->list, rdata_list);
3136		offset += cur_len;
3137		len -= cur_len;
3138	} while (len > 0);
3139
3140	return rc;
3141}
3142
3143static void
3144collect_uncached_read_data(struct cifs_aio_ctx *ctx)
3145{
3146	struct cifs_readdata *rdata, *tmp;
3147	struct iov_iter *to = &ctx->iter;
3148	struct cifs_sb_info *cifs_sb;
3149	struct cifs_tcon *tcon;
3150	unsigned int i;
3151	int rc;
3152
3153	tcon = tlink_tcon(ctx->cfile->tlink);
3154	cifs_sb = CIFS_SB(ctx->cfile->dentry->d_sb);
3155
3156	mutex_lock(&ctx->aio_mutex);
 
 
3157
3158	if (list_empty(&ctx->list)) {
3159		mutex_unlock(&ctx->aio_mutex);
3160		return;
3161	}
3162
3163	rc = ctx->rc;
3164	/* the loop below should proceed in the order of increasing offsets */
3165again:
3166	list_for_each_entry_safe(rdata, tmp, &ctx->list, list) {
3167		if (!rc) {
3168			if (!try_wait_for_completion(&rdata->done)) {
3169				mutex_unlock(&ctx->aio_mutex);
3170				return;
3171			}
3172
3173			if (rdata->result == -EAGAIN) {
3174				/* resend call if it's a retryable error */
3175				struct list_head tmp_list;
3176				unsigned int got_bytes = rdata->got_bytes;
3177
3178				list_del_init(&rdata->list);
3179				INIT_LIST_HEAD(&tmp_list);
3180
3181				/*
3182				 * Got a part of data and then reconnect has
3183				 * happened -- fill the buffer and continue
3184				 * reading.
3185				 */
3186				if (got_bytes && got_bytes < rdata->bytes) {
3187					rc = cifs_readdata_to_iov(rdata, to);
3188					if (rc) {
3189						kref_put(&rdata->refcount,
3190						cifs_uncached_readdata_release);
3191						continue;
3192					}
3193				}
3194
3195				rc = cifs_send_async_read(
3196						rdata->offset + got_bytes,
3197						rdata->bytes - got_bytes,
3198						rdata->cfile, cifs_sb,
3199						&tmp_list, ctx);
3200
3201				list_splice(&tmp_list, &ctx->list);
3202
3203				kref_put(&rdata->refcount,
3204					 cifs_uncached_readdata_release);
3205				goto again;
3206			} else if (rdata->result)
3207				rc = rdata->result;
3208			else
3209				rc = cifs_readdata_to_iov(rdata, to);
3210
3211			/* if there was a short read -- discard anything left */
3212			if (rdata->got_bytes && rdata->got_bytes < rdata->bytes)
3213				rc = -ENODATA;
3214		}
3215		list_del_init(&rdata->list);
3216		kref_put(&rdata->refcount, cifs_uncached_readdata_release);
3217	}
3218
3219	for (i = 0; i < ctx->npages; i++) {
3220		if (ctx->should_dirty)
3221			set_page_dirty(ctx->bv[i].bv_page);
3222		put_page(ctx->bv[i].bv_page);
3223	}
3224
3225	ctx->total_len = ctx->len - iov_iter_count(to);
3226
3227	cifs_stats_bytes_read(tcon, ctx->total_len);
3228
3229	/* mask nodata case */
3230	if (rc == -ENODATA)
3231		rc = 0;
3232
3233	ctx->rc = (rc == 0) ? ctx->total_len : rc;
3234
3235	mutex_unlock(&ctx->aio_mutex);
3236
3237	if (ctx->iocb && ctx->iocb->ki_complete)
3238		ctx->iocb->ki_complete(ctx->iocb, ctx->rc, 0);
3239	else
3240		complete(&ctx->done);
3241}
3242
3243ssize_t cifs_user_readv(struct kiocb *iocb, struct iov_iter *to)
 
3244{
3245	struct file *file = iocb->ki_filp;
3246	ssize_t rc;
3247	size_t len;
3248	ssize_t total_read = 0;
3249	loff_t offset = iocb->ki_pos;
3250	struct cifs_sb_info *cifs_sb;
3251	struct cifs_tcon *tcon;
3252	struct cifsFileInfo *cfile;
3253	struct cifs_aio_ctx *ctx;
3254
3255	len = iov_iter_count(to);
3256	if (!len)
3257		return 0;
3258
3259	cifs_sb = CIFS_FILE_SB(file);
3260	cfile = file->private_data;
3261	tcon = tlink_tcon(cfile->tlink);
3262
3263	if (!tcon->ses->server->ops->async_readv)
3264		return -ENOSYS;
3265
3266	if ((file->f_flags & O_ACCMODE) == O_WRONLY)
3267		cifs_dbg(FYI, "attempting read on write only file instance\n");
3268
3269	ctx = cifs_aio_ctx_alloc();
3270	if (!ctx)
3271		return -ENOMEM;
3272
3273	ctx->cfile = cifsFileInfo_get(cfile);
3274
3275	if (!is_sync_kiocb(iocb))
3276		ctx->iocb = iocb;
3277
3278	if (to->type == ITER_IOVEC)
3279		ctx->should_dirty = true;
3280
3281	rc = setup_aio_ctx_iter(ctx, to, READ);
3282	if (rc) {
3283		kref_put(&ctx->refcount, cifs_aio_ctx_release);
3284		return rc;
3285	}
3286
3287	len = ctx->len;
3288
3289	/* grab a lock here due to read response handlers can access ctx */
3290	mutex_lock(&ctx->aio_mutex);
3291
3292	rc = cifs_send_async_read(offset, len, cfile, cifs_sb, &ctx->list, ctx);
3293
3294	/* if at least one read request send succeeded, then reset rc */
3295	if (!list_empty(&ctx->list))
3296		rc = 0;
3297
3298	mutex_unlock(&ctx->aio_mutex);
3299
3300	if (rc) {
3301		kref_put(&ctx->refcount, cifs_aio_ctx_release);
3302		return rc;
3303	}
3304
3305	if (!is_sync_kiocb(iocb)) {
3306		kref_put(&ctx->refcount, cifs_aio_ctx_release);
3307		return -EIOCBQUEUED;
3308	}
3309
3310	rc = wait_for_completion_killable(&ctx->done);
3311	if (rc) {
3312		mutex_lock(&ctx->aio_mutex);
3313		ctx->rc = rc = -EINTR;
3314		total_read = ctx->total_len;
3315		mutex_unlock(&ctx->aio_mutex);
3316	} else {
3317		rc = ctx->rc;
3318		total_read = ctx->total_len;
3319	}
3320
3321	kref_put(&ctx->refcount, cifs_aio_ctx_release);
3322
3323	if (total_read) {
3324		iocb->ki_pos += total_read;
3325		return total_read;
3326	}
3327	return rc;
3328}
3329
3330ssize_t
3331cifs_strict_readv(struct kiocb *iocb, struct iov_iter *to)
3332{
3333	struct inode *inode = file_inode(iocb->ki_filp);
3334	struct cifsInodeInfo *cinode = CIFS_I(inode);
3335	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
3336	struct cifsFileInfo *cfile = (struct cifsFileInfo *)
3337						iocb->ki_filp->private_data;
3338	struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
3339	int rc = -EACCES;
3340
3341	/*
3342	 * In strict cache mode we need to read from the server all the time
3343	 * if we don't have level II oplock because the server can delay mtime
3344	 * change - so we can't make a decision about inode invalidating.
3345	 * And we can also fail with pagereading if there are mandatory locks
3346	 * on pages affected by this read but not on the region from pos to
3347	 * pos+len-1.
3348	 */
3349	if (!CIFS_CACHE_READ(cinode))
3350		return cifs_user_readv(iocb, to);
3351
3352	if (cap_unix(tcon->ses) &&
3353	    (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
3354	    ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
3355		return generic_file_read_iter(iocb, to);
3356
3357	/*
3358	 * We need to hold the sem to be sure nobody modifies lock list
3359	 * with a brlock that prevents reading.
3360	 */
3361	down_read(&cinode->lock_sem);
3362	if (!cifs_find_lock_conflict(cfile, iocb->ki_pos, iov_iter_count(to),
3363				     tcon->ses->server->vals->shared_lock_type,
3364				     NULL, CIFS_READ_OP))
3365		rc = generic_file_read_iter(iocb, to);
3366	up_read(&cinode->lock_sem);
3367	return rc;
3368}
3369
3370static ssize_t
3371cifs_read(struct file *file, char *read_data, size_t read_size, loff_t *offset)
3372{
3373	int rc = -EACCES;
3374	unsigned int bytes_read = 0;
3375	unsigned int total_read;
3376	unsigned int current_read_size;
3377	unsigned int rsize;
3378	struct cifs_sb_info *cifs_sb;
3379	struct cifs_tcon *tcon;
3380	struct TCP_Server_Info *server;
3381	unsigned int xid;
3382	char *cur_offset;
3383	struct cifsFileInfo *open_file;
3384	struct cifs_io_parms io_parms;
3385	int buf_type = CIFS_NO_BUFFER;
3386	__u32 pid;
3387
3388	xid = get_xid();
3389	cifs_sb = CIFS_FILE_SB(file);
3390
3391	/* FIXME: set up handlers for larger reads and/or convert to async */
3392	rsize = min_t(unsigned int, cifs_sb->rsize, CIFSMaxBufSize);
3393
3394	if (file->private_data == NULL) {
3395		rc = -EBADF;
3396		free_xid(xid);
3397		return rc;
3398	}
3399	open_file = file->private_data;
3400	tcon = tlink_tcon(open_file->tlink);
3401	server = tcon->ses->server;
3402
3403	if (!server->ops->sync_read) {
3404		free_xid(xid);
3405		return -ENOSYS;
3406	}
3407
3408	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
3409		pid = open_file->pid;
3410	else
3411		pid = current->tgid;
3412
3413	if ((file->f_flags & O_ACCMODE) == O_WRONLY)
3414		cifs_dbg(FYI, "attempting read on write only file instance\n");
3415
3416	for (total_read = 0, cur_offset = read_data; read_size > total_read;
3417	     total_read += bytes_read, cur_offset += bytes_read) {
3418		do {
3419			current_read_size = min_t(uint, read_size - total_read,
3420						  rsize);
3421			/*
3422			 * For windows me and 9x we do not want to request more
3423			 * than it negotiated since it will refuse the read
3424			 * then.
3425			 */
3426			if ((tcon->ses) && !(tcon->ses->capabilities &
3427				tcon->ses->server->vals->cap_large_files)) {
3428				current_read_size = min_t(uint,
3429					current_read_size, CIFSMaxBufSize);
3430			}
3431			if (open_file->invalidHandle) {
3432				rc = cifs_reopen_file(open_file, true);
3433				if (rc != 0)
3434					break;
3435			}
 
3436			io_parms.pid = pid;
3437			io_parms.tcon = tcon;
3438			io_parms.offset = *offset;
3439			io_parms.length = current_read_size;
3440			rc = server->ops->sync_read(xid, &open_file->fid, &io_parms,
3441						    &bytes_read, &cur_offset,
3442						    &buf_type);
3443		} while (rc == -EAGAIN);
3444
3445		if (rc || (bytes_read == 0)) {
3446			if (total_read) {
3447				break;
3448			} else {
3449				free_xid(xid);
3450				return rc;
3451			}
3452		} else {
3453			cifs_stats_bytes_read(tcon, total_read);
3454			*offset += bytes_read;
3455		}
3456	}
3457	free_xid(xid);
3458	return total_read;
3459}
3460
3461/*
3462 * If the page is mmap'ed into a process' page tables, then we need to make
3463 * sure that it doesn't change while being written back.
3464 */
3465static vm_fault_t
3466cifs_page_mkwrite(struct vm_fault *vmf)
3467{
3468	struct page *page = vmf->page;
3469
3470	lock_page(page);
3471	return VM_FAULT_LOCKED;
3472}
3473
3474static const struct vm_operations_struct cifs_file_vm_ops = {
3475	.fault = filemap_fault,
3476	.map_pages = filemap_map_pages,
3477	.page_mkwrite = cifs_page_mkwrite,
3478};
3479
3480int cifs_file_strict_mmap(struct file *file, struct vm_area_struct *vma)
3481{
3482	int xid, rc = 0;
3483	struct inode *inode = file_inode(file);
 
 
3484
3485	xid = get_xid();
 
 
 
 
3486
3487	if (!CIFS_CACHE_READ(CIFS_I(inode)))
3488		rc = cifs_zap_mapping(inode);
3489	if (!rc)
3490		rc = generic_file_mmap(file, vma);
3491	if (!rc)
3492		vma->vm_ops = &cifs_file_vm_ops;
3493
3494	free_xid(xid);
3495	return rc;
3496}
3497
3498int cifs_file_mmap(struct file *file, struct vm_area_struct *vma)
3499{
3500	int rc, xid;
3501
3502	xid = get_xid();
3503
3504	rc = cifs_revalidate_file(file);
3505	if (rc)
3506		cifs_dbg(FYI, "Validation prior to mmap failed, error=%d\n",
3507			 rc);
3508	if (!rc)
3509		rc = generic_file_mmap(file, vma);
3510	if (!rc)
 
3511		vma->vm_ops = &cifs_file_vm_ops;
3512
3513	free_xid(xid);
3514	return rc;
3515}
3516
3517static void
3518cifs_readv_complete(struct work_struct *work)
 
3519{
3520	unsigned int i, got_bytes;
3521	struct cifs_readdata *rdata = container_of(work,
3522						struct cifs_readdata, work);
3523
3524	got_bytes = rdata->got_bytes;
3525	for (i = 0; i < rdata->nr_pages; i++) {
3526		struct page *page = rdata->pages[i];
3527
3528		lru_cache_add_file(page);
3529
3530		if (rdata->result == 0 ||
3531		    (rdata->result == -EAGAIN && got_bytes)) {
3532			flush_dcache_page(page);
3533			SetPageUptodate(page);
3534		}
3535
3536		unlock_page(page);
 
 
3537
3538		if (rdata->result == 0 ||
3539		    (rdata->result == -EAGAIN && got_bytes))
3540			cifs_readpage_to_fscache(rdata->mapping->host, page);
3541
3542		got_bytes -= min_t(unsigned int, PAGE_SIZE, got_bytes);
 
 
 
 
 
 
 
 
3543
3544		put_page(page);
3545		rdata->pages[i] = NULL;
3546	}
3547	kref_put(&rdata->refcount, cifs_readdata_release);
3548}
3549
3550static int
3551readpages_fill_pages(struct TCP_Server_Info *server,
3552		     struct cifs_readdata *rdata, struct iov_iter *iter,
3553		     unsigned int len)
3554{
3555	int result = 0;
3556	unsigned int i;
3557	u64 eof;
3558	pgoff_t eof_index;
3559	unsigned int nr_pages = rdata->nr_pages;
3560
3561	/* determine the eof that the server (probably) has */
3562	eof = CIFS_I(rdata->mapping->host)->server_eof;
3563	eof_index = eof ? (eof - 1) >> PAGE_SHIFT : 0;
3564	cifs_dbg(FYI, "eof=%llu eof_index=%lu\n", eof, eof_index);
3565
3566	rdata->got_bytes = 0;
3567	rdata->tailsz = PAGE_SIZE;
3568	for (i = 0; i < nr_pages; i++) {
3569		struct page *page = rdata->pages[i];
3570		size_t n = PAGE_SIZE;
3571
3572		if (len >= PAGE_SIZE) {
3573			len -= PAGE_SIZE;
3574		} else if (len > 0) {
3575			/* enough for partial page, fill and zero the rest */
3576			zero_user(page, len, PAGE_SIZE - len);
3577			n = rdata->tailsz = len;
3578			len = 0;
3579		} else if (page->index > eof_index) {
3580			/*
3581			 * The VFS will not try to do readahead past the
3582			 * i_size, but it's possible that we have outstanding
3583			 * writes with gaps in the middle and the i_size hasn't
3584			 * caught up yet. Populate those with zeroed out pages
3585			 * to prevent the VFS from repeatedly attempting to
3586			 * fill them until the writes are flushed.
3587			 */
3588			zero_user(page, 0, PAGE_SIZE);
3589			lru_cache_add_file(page);
3590			flush_dcache_page(page);
3591			SetPageUptodate(page);
3592			unlock_page(page);
3593			put_page(page);
3594			rdata->pages[i] = NULL;
3595			rdata->nr_pages--;
3596			continue;
3597		} else {
3598			/* no need to hold page hostage */
3599			lru_cache_add_file(page);
3600			unlock_page(page);
3601			put_page(page);
3602			rdata->pages[i] = NULL;
3603			rdata->nr_pages--;
3604			continue;
3605		}
 
3606
3607		if (iter)
3608			result = copy_page_from_iter(page, 0, n, iter);
3609#ifdef CONFIG_CIFS_SMB_DIRECT
3610		else if (rdata->mr)
3611			result = n;
3612#endif
3613		else
3614			result = cifs_read_page_from_socket(server, page, n);
3615		if (result < 0)
3616			break;
3617
3618		rdata->got_bytes += result;
 
3619	}
3620
3621	return rdata->got_bytes > 0 && result != -ECONNABORTED ?
3622						rdata->got_bytes : result;
3623}
3624
3625static int
3626cifs_readpages_read_into_pages(struct TCP_Server_Info *server,
3627			       struct cifs_readdata *rdata, unsigned int len)
3628{
3629	return readpages_fill_pages(server, rdata, NULL, len);
3630}
 
 
 
 
 
 
 
 
 
 
 
 
3631
3632static int
3633cifs_readpages_copy_into_pages(struct TCP_Server_Info *server,
3634			       struct cifs_readdata *rdata,
3635			       struct iov_iter *iter)
3636{
3637	return readpages_fill_pages(server, rdata, iter, iter->count);
3638}
3639
3640static int
3641readpages_get_pages(struct address_space *mapping, struct list_head *page_list,
3642		    unsigned int rsize, struct list_head *tmplist,
3643		    unsigned int *nr_pages, loff_t *offset, unsigned int *bytes)
3644{
3645	struct page *page, *tpage;
3646	unsigned int expected_index;
3647	int rc;
3648	gfp_t gfp = readahead_gfp_mask(mapping);
3649
3650	INIT_LIST_HEAD(tmplist);
3651
3652	page = list_entry(page_list->prev, struct page, lru);
3653
3654	/*
3655	 * Lock the page and put it in the cache. Since no one else
3656	 * should have access to this page, we're safe to simply set
3657	 * PG_locked without checking it first.
3658	 */
3659	__SetPageLocked(page);
3660	rc = add_to_page_cache_locked(page, mapping,
3661				      page->index, gfp);
3662
3663	/* give up if we can't stick it in the cache */
3664	if (rc) {
3665		__ClearPageLocked(page);
3666		return rc;
3667	}
3668
3669	/* move first page to the tmplist */
3670	*offset = (loff_t)page->index << PAGE_SHIFT;
3671	*bytes = PAGE_SIZE;
3672	*nr_pages = 1;
3673	list_move_tail(&page->lru, tmplist);
3674
3675	/* now try and add more pages onto the request */
3676	expected_index = page->index + 1;
3677	list_for_each_entry_safe_reverse(page, tpage, page_list, lru) {
3678		/* discontinuity ? */
3679		if (page->index != expected_index)
3680			break;
3681
3682		/* would this page push the read over the rsize? */
3683		if (*bytes + PAGE_SIZE > rsize)
3684			break;
3685
3686		__SetPageLocked(page);
3687		if (add_to_page_cache_locked(page, mapping, page->index, gfp)) {
3688			__ClearPageLocked(page);
3689			break;
3690		}
3691		list_move_tail(&page->lru, tmplist);
3692		(*bytes) += PAGE_SIZE;
3693		expected_index++;
3694		(*nr_pages)++;
3695	}
3696	return rc;
3697}
3698
3699static int cifs_readpages(struct file *file, struct address_space *mapping,
3700	struct list_head *page_list, unsigned num_pages)
3701{
3702	int rc;
3703	struct list_head tmplist;
3704	struct cifsFileInfo *open_file = file->private_data;
3705	struct cifs_sb_info *cifs_sb = CIFS_FILE_SB(file);
3706	struct TCP_Server_Info *server;
3707	pid_t pid;
3708
3709	/*
3710	 * Reads as many pages as possible from fscache. Returns -ENOBUFS
3711	 * immediately if the cookie is negative
3712	 *
3713	 * After this point, every page in the list might have PG_fscache set,
3714	 * so we will need to clean that up off of every page we don't use.
3715	 */
3716	rc = cifs_readpages_from_fscache(mapping->host, mapping, page_list,
3717					 &num_pages);
3718	if (rc == 0)
3719		return rc;
3720
 
3721	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
3722		pid = open_file->pid;
3723	else
3724		pid = current->tgid;
3725
3726	rc = 0;
3727	server = tlink_tcon(open_file->tlink)->ses->server;
3728
3729	cifs_dbg(FYI, "%s: file=%p mapping=%p num_pages=%u\n",
3730		 __func__, file, mapping, num_pages);
3731
3732	/*
3733	 * Start with the page at end of list and move it to private
3734	 * list. Do the same with any following pages until we hit
3735	 * the rsize limit, hit an index discontinuity, or run out of
3736	 * pages. Issue the async read and then start the loop again
3737	 * until the list is empty.
3738	 *
3739	 * Note that list order is important. The page_list is in
3740	 * the order of declining indexes. When we put the pages in
3741	 * the rdata->pages, then we want them in increasing order.
3742	 */
3743	while (!list_empty(page_list)) {
3744		unsigned int i, nr_pages, bytes, rsize;
3745		loff_t offset;
3746		struct page *page, *tpage;
3747		struct cifs_readdata *rdata;
3748		unsigned credits;
3749
3750		rc = server->ops->wait_mtu_credits(server, cifs_sb->rsize,
3751						   &rsize, &credits);
3752		if (rc)
3753			break;
3754
3755		/*
3756		 * Give up immediately if rsize is too small to read an entire
3757		 * page. The VFS will fall back to readpage. We should never
3758		 * reach this point however since we set ra_pages to 0 when the
3759		 * rsize is smaller than a cache page.
3760		 */
3761		if (unlikely(rsize < PAGE_SIZE)) {
3762			add_credits_and_wake_if(server, credits, 0);
3763			return 0;
3764		}
 
 
3765
3766		rc = readpages_get_pages(mapping, page_list, rsize, &tmplist,
3767					 &nr_pages, &offset, &bytes);
3768		if (rc) {
3769			add_credits_and_wake_if(server, credits, 0);
3770			break;
3771		}
3772
3773		rdata = cifs_readdata_alloc(nr_pages, cifs_readv_complete);
3774		if (!rdata) {
3775			/* best to give up if we're out of mem */
3776			list_for_each_entry_safe(page, tpage, &tmplist, lru) {
3777				list_del(&page->lru);
3778				lru_cache_add_file(page);
3779				unlock_page(page);
3780				put_page(page);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3781			}
3782			rc = -ENOMEM;
3783			add_credits_and_wake_if(server, credits, 0);
 
3784			break;
3785		}
3786
3787		rdata->cfile = cifsFileInfo_get(open_file);
3788		rdata->mapping = mapping;
3789		rdata->offset = offset;
3790		rdata->bytes = bytes;
3791		rdata->pid = pid;
3792		rdata->pagesz = PAGE_SIZE;
3793		rdata->read_into_pages = cifs_readpages_read_into_pages;
3794		rdata->copy_into_pages = cifs_readpages_copy_into_pages;
3795		rdata->credits = credits;
3796
3797		list_for_each_entry_safe(page, tpage, &tmplist, lru) {
3798			list_del(&page->lru);
3799			rdata->pages[rdata->nr_pages++] = page;
3800		}
 
3801
3802		if (!rdata->cfile->invalidHandle ||
3803		    !(rc = cifs_reopen_file(rdata->cfile, true)))
3804			rc = server->ops->async_readv(rdata);
3805		if (rc) {
3806			add_credits_and_wake_if(server, rdata->credits, 0);
3807			for (i = 0; i < rdata->nr_pages; i++) {
3808				page = rdata->pages[i];
3809				lru_cache_add_file(page);
3810				unlock_page(page);
3811				put_page(page);
3812			}
3813			/* Fallback to the readpage in error/reconnect cases */
3814			kref_put(&rdata->refcount, cifs_readdata_release);
3815			break;
3816		}
3817
3818		kref_put(&rdata->refcount, cifs_readdata_release);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3819	}
3820
3821	/* Any pages that have been shown to fscache but didn't get added to
3822	 * the pagecache must be uncached before they get returned to the
3823	 * allocator.
3824	 */
3825	cifs_fscache_readpages_cancel(mapping->host, page_list);
3826	return rc;
3827}
3828
3829/*
3830 * cifs_readpage_worker must be called with the page pinned
3831 */
3832static int cifs_readpage_worker(struct file *file, struct page *page,
3833	loff_t *poffset)
3834{
3835	char *read_data;
3836	int rc;
3837
3838	/* Is the page cached? */
3839	rc = cifs_readpage_from_fscache(file_inode(file), page);
3840	if (rc == 0)
3841		goto read_complete;
3842
 
3843	read_data = kmap(page);
3844	/* for reads over a certain size could initiate async read ahead */
3845
3846	rc = cifs_read(file, read_data, PAGE_SIZE, poffset);
3847
3848	if (rc < 0)
3849		goto io_error;
3850	else
3851		cifs_dbg(FYI, "Bytes read %d\n", rc);
3852
3853	file_inode(file)->i_atime =
3854		current_time(file_inode(file));
3855
3856	if (PAGE_SIZE > rc)
3857		memset(read_data + rc, 0, PAGE_SIZE - rc);
3858
3859	flush_dcache_page(page);
3860	SetPageUptodate(page);
3861
3862	/* send this page to the cache */
3863	cifs_readpage_to_fscache(file_inode(file), page);
3864
3865	rc = 0;
3866
3867io_error:
3868	kunmap(page);
3869	unlock_page(page);
3870
3871read_complete:
3872	return rc;
3873}
3874
3875static int cifs_readpage(struct file *file, struct page *page)
3876{
3877	loff_t offset = (loff_t)page->index << PAGE_SHIFT;
3878	int rc = -EACCES;
3879	unsigned int xid;
3880
3881	xid = get_xid();
3882
3883	if (file->private_data == NULL) {
3884		rc = -EBADF;
3885		free_xid(xid);
3886		return rc;
3887	}
3888
3889	cifs_dbg(FYI, "readpage %p at offset %d 0x%x\n",
3890		 page, (int)offset, (int)offset);
3891
3892	rc = cifs_readpage_worker(file, page, &offset);
3893
3894	free_xid(xid);
 
 
3895	return rc;
3896}
3897
3898static int is_inode_writable(struct cifsInodeInfo *cifs_inode)
3899{
3900	struct cifsFileInfo *open_file;
3901	struct cifs_tcon *tcon =
3902		cifs_sb_master_tcon(CIFS_SB(cifs_inode->vfs_inode.i_sb));
3903
3904	spin_lock(&tcon->open_file_lock);
3905	list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
3906		if (OPEN_FMODE(open_file->f_flags) & FMODE_WRITE) {
3907			spin_unlock(&tcon->open_file_lock);
3908			return 1;
3909		}
3910	}
3911	spin_unlock(&tcon->open_file_lock);
3912	return 0;
3913}
3914
3915/* We do not want to update the file size from server for inodes
3916   open for write - to avoid races with writepage extending
3917   the file - in the future we could consider allowing
3918   refreshing the inode only on increases in the file size
3919   but this is tricky to do without racing with writebehind
3920   page caching in the current Linux kernel design */
3921bool is_size_safe_to_change(struct cifsInodeInfo *cifsInode, __u64 end_of_file)
3922{
3923	if (!cifsInode)
3924		return true;
3925
3926	if (is_inode_writable(cifsInode)) {
3927		/* This inode is open for write at least once */
3928		struct cifs_sb_info *cifs_sb;
3929
3930		cifs_sb = CIFS_SB(cifsInode->vfs_inode.i_sb);
3931		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DIRECT_IO) {
3932			/* since no page cache to corrupt on directio
3933			we can change size safely */
3934			return true;
3935		}
3936
3937		if (i_size_read(&cifsInode->vfs_inode) < end_of_file)
3938			return true;
3939
3940		return false;
3941	} else
3942		return true;
3943}
3944
3945static int cifs_write_begin(struct file *file, struct address_space *mapping,
3946			loff_t pos, unsigned len, unsigned flags,
3947			struct page **pagep, void **fsdata)
3948{
3949	int oncethru = 0;
3950	pgoff_t index = pos >> PAGE_SHIFT;
3951	loff_t offset = pos & (PAGE_SIZE - 1);
3952	loff_t page_start = pos & PAGE_MASK;
3953	loff_t i_size;
3954	struct page *page;
3955	int rc = 0;
3956
3957	cifs_dbg(FYI, "write_begin from %lld len %d\n", (long long)pos, len);
3958
3959start:
3960	page = grab_cache_page_write_begin(mapping, index, flags);
3961	if (!page) {
3962		rc = -ENOMEM;
3963		goto out;
3964	}
3965
3966	if (PageUptodate(page))
3967		goto out;
3968
3969	/*
3970	 * If we write a full page it will be up to date, no need to read from
3971	 * the server. If the write is short, we'll end up doing a sync write
3972	 * instead.
3973	 */
3974	if (len == PAGE_SIZE)
3975		goto out;
3976
3977	/*
3978	 * optimize away the read when we have an oplock, and we're not
3979	 * expecting to use any of the data we'd be reading in. That
3980	 * is, when the page lies beyond the EOF, or straddles the EOF
3981	 * and the write will cover all of the existing data.
3982	 */
3983	if (CIFS_CACHE_READ(CIFS_I(mapping->host))) {
3984		i_size = i_size_read(mapping->host);
3985		if (page_start >= i_size ||
3986		    (offset == 0 && (pos + len) >= i_size)) {
3987			zero_user_segments(page, 0, offset,
3988					   offset + len,
3989					   PAGE_SIZE);
3990			/*
3991			 * PageChecked means that the parts of the page
3992			 * to which we're not writing are considered up
3993			 * to date. Once the data is copied to the
3994			 * page, it can be set uptodate.
3995			 */
3996			SetPageChecked(page);
3997			goto out;
3998		}
3999	}
4000
4001	if ((file->f_flags & O_ACCMODE) != O_WRONLY && !oncethru) {
4002		/*
4003		 * might as well read a page, it is fast enough. If we get
4004		 * an error, we don't need to return it. cifs_write_end will
4005		 * do a sync write instead since PG_uptodate isn't set.
4006		 */
4007		cifs_readpage_worker(file, page, &page_start);
4008		put_page(page);
4009		oncethru = 1;
4010		goto start;
4011	} else {
4012		/* we could try using another file handle if there is one -
4013		   but how would we lock it to prevent close of that handle
4014		   racing with this read? In any case
4015		   this will be written out by write_end so is fine */
4016	}
4017out:
4018	*pagep = page;
4019	return rc;
4020}
4021
4022static int cifs_release_page(struct page *page, gfp_t gfp)
4023{
4024	if (PagePrivate(page))
4025		return 0;
4026
4027	return cifs_fscache_release_page(page, gfp);
4028}
4029
4030static void cifs_invalidate_page(struct page *page, unsigned int offset,
4031				 unsigned int length)
4032{
4033	struct cifsInodeInfo *cifsi = CIFS_I(page->mapping->host);
4034
4035	if (offset == 0 && length == PAGE_SIZE)
4036		cifs_fscache_invalidate_page(page, &cifsi->vfs_inode);
4037}
4038
4039static int cifs_launder_page(struct page *page)
4040{
4041	int rc = 0;
4042	loff_t range_start = page_offset(page);
4043	loff_t range_end = range_start + (loff_t)(PAGE_SIZE - 1);
4044	struct writeback_control wbc = {
4045		.sync_mode = WB_SYNC_ALL,
4046		.nr_to_write = 0,
4047		.range_start = range_start,
4048		.range_end = range_end,
4049	};
4050
4051	cifs_dbg(FYI, "Launder page: %p\n", page);
4052
4053	if (clear_page_dirty_for_io(page))
4054		rc = cifs_writepage_locked(page, &wbc);
4055
4056	cifs_fscache_invalidate_page(page, page->mapping->host);
4057	return rc;
4058}
4059
4060void cifs_oplock_break(struct work_struct *work)
4061{
4062	struct cifsFileInfo *cfile = container_of(work, struct cifsFileInfo,
4063						  oplock_break);
4064	struct inode *inode = d_inode(cfile->dentry);
4065	struct cifsInodeInfo *cinode = CIFS_I(inode);
4066	struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
4067	struct TCP_Server_Info *server = tcon->ses->server;
4068	int rc = 0;
4069
4070	wait_on_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS,
4071			TASK_UNINTERRUPTIBLE);
4072
4073	server->ops->downgrade_oplock(server, cinode,
4074		test_bit(CIFS_INODE_DOWNGRADE_OPLOCK_TO_L2, &cinode->flags));
4075
4076	if (!CIFS_CACHE_WRITE(cinode) && CIFS_CACHE_READ(cinode) &&
4077						cifs_has_mand_locks(cinode)) {
4078		cifs_dbg(FYI, "Reset oplock to None for inode=%p due to mand locks\n",
4079			 inode);
4080		cinode->oplock = 0;
4081	}
4082
4083	if (inode && S_ISREG(inode->i_mode)) {
4084		if (CIFS_CACHE_READ(cinode))
4085			break_lease(inode, O_RDONLY);
4086		else
4087			break_lease(inode, O_WRONLY);
4088		rc = filemap_fdatawrite(inode->i_mapping);
4089		if (!CIFS_CACHE_READ(cinode)) {
4090			rc = filemap_fdatawait(inode->i_mapping);
4091			mapping_set_error(inode->i_mapping, rc);
4092			cifs_zap_mapping(inode);
4093		}
4094		cifs_dbg(FYI, "Oplock flush inode %p rc %d\n", inode, rc);
4095	}
4096
4097	rc = cifs_push_locks(cfile);
4098	if (rc)
4099		cifs_dbg(VFS, "Push locks rc = %d\n", rc);
4100
4101	/*
4102	 * releasing stale oplock after recent reconnect of smb session using
4103	 * a now incorrect file handle is not a data integrity issue but do
4104	 * not bother sending an oplock release if session to server still is
4105	 * disconnected since oplock already released by the server
4106	 */
4107	if (!cfile->oplock_break_cancelled) {
4108		rc = tcon->ses->server->ops->oplock_response(tcon, &cfile->fid,
4109							     cinode);
4110		cifs_dbg(FYI, "Oplock release rc = %d\n", rc);
 
4111	}
4112	cifs_done_oplock_break(cinode);
4113}
4114
4115/*
4116 * The presence of cifs_direct_io() in the address space ops vector
4117 * allowes open() O_DIRECT flags which would have failed otherwise.
4118 *
4119 * In the non-cached mode (mount with cache=none), we shunt off direct read and write requests
4120 * so this method should never be called.
4121 *
4122 * Direct IO is not yet supported in the cached mode. 
4123 */
4124static ssize_t
4125cifs_direct_io(struct kiocb *iocb, struct iov_iter *iter)
4126{
4127        /*
4128         * FIXME
4129         * Eventually need to support direct IO for non forcedirectio mounts
4130         */
4131        return -EINVAL;
4132}
4133
4134
4135const struct address_space_operations cifs_addr_ops = {
4136	.readpage = cifs_readpage,
4137	.readpages = cifs_readpages,
4138	.writepage = cifs_writepage,
4139	.writepages = cifs_writepages,
4140	.write_begin = cifs_write_begin,
4141	.write_end = cifs_write_end,
4142	.set_page_dirty = __set_page_dirty_nobuffers,
4143	.releasepage = cifs_release_page,
4144	.direct_IO = cifs_direct_io,
4145	.invalidatepage = cifs_invalidate_page,
4146	.launder_page = cifs_launder_page,
4147};
4148
4149/*
4150 * cifs_readpages requires the server to support a buffer large enough to
4151 * contain the header plus one complete page of data.  Otherwise, we need
4152 * to leave cifs_readpages out of the address space operations.
4153 */
4154const struct address_space_operations cifs_addr_ops_smallbuf = {
4155	.readpage = cifs_readpage,
4156	.writepage = cifs_writepage,
4157	.writepages = cifs_writepages,
4158	.write_begin = cifs_write_begin,
4159	.write_end = cifs_write_end,
4160	.set_page_dirty = __set_page_dirty_nobuffers,
4161	.releasepage = cifs_release_page,
4162	.invalidatepage = cifs_invalidate_page,
4163	.launder_page = cifs_launder_page,
4164};