fs/cifs/file.c

   1 /*
   2  *   fs/cifs/file.c
   3  *
   4  *   vfs operations that deal with files
   5  *
   6  *   Copyright (C) International Business Machines  Corp., 2002,2007
   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 <asm/div64.h>
  34 #include "cifsfs.h"
  35 #include "cifspdu.h"
  36 #include "cifsglob.h"
  37 #include "cifsproto.h"
  38 #include "cifs_unicode.h"
  39 #include "cifs_debug.h"
  40 #include "cifs_fs_sb.h"
  41
  42 static inline struct cifsFileInfo *cifs_init_private(
  43         struct cifsFileInfo *private_data, struct inode *inode,
  44         struct file *file, __u16 netfid)
  45 {
  46         memset(private_data, 0, sizeof(struct cifsFileInfo));
  47         private_data->netfid = netfid;
  48         private_data->pid = current->tgid;
  49         init_MUTEX(&private_data->fh_sem);
  50         mutex_init(&private_data->lock_mutex);
  51         INIT_LIST_HEAD(&private_data->llist);
  52         private_data->pfile = file; /* needed for writepage */
  53         private_data->pInode = inode;
  54         private_data->invalidHandle = FALSE;
  55         private_data->closePend = FALSE;
  56         /* we have to track num writers to the inode, since writepages
  57         does not tell us which handle the write is for so there can
  58         be a close (overlapping with write) of the filehandle that
  59         cifs_writepages chose to use */
  60         atomic_set(&private_data->wrtPending, 0);
  61
  62         return private_data;
  63 }
  64
  65 static inline int cifs_convert_flags(unsigned int flags)
  66 {
  67         if ((flags & O_ACCMODE) == O_RDONLY)
  68                 return GENERIC_READ;
  69         else if ((flags & O_ACCMODE) == O_WRONLY)
  70                 return GENERIC_WRITE;
  71         else if ((flags & O_ACCMODE) == O_RDWR) {
  72                 /* GENERIC_ALL is too much permission to request
  73                    can cause unnecessary access denied on create */
  74                 /* return GENERIC_ALL; */
  75                 return (GENERIC_READ | GENERIC_WRITE);
  76         }
  77
  78         return 0x20197;
  79 }
  80
  81 static inline int cifs_get_disposition(unsigned int flags)
  82 {
  83         if ((flags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
  84                 return FILE_CREATE;
  85         else if ((flags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
  86                 return FILE_OVERWRITE_IF;
  87         else if ((flags & O_CREAT) == O_CREAT)
  88                 return FILE_OPEN_IF;
  89         else if ((flags & O_TRUNC) == O_TRUNC)
  90                 return FILE_OVERWRITE;
  91         else
  92                 return FILE_OPEN;
  93 }
  94
  95 /* all arguments to this function must be checked for validity in caller */
  96 static inline int cifs_open_inode_helper(struct inode *inode, struct file *file,
  97         struct cifsInodeInfo *pCifsInode, struct cifsFileInfo *pCifsFile,
  98         struct cifsTconInfo *pTcon, int *oplock, FILE_ALL_INFO *buf,
  99         char *full_path, int xid)
 100 {
 101         struct timespec temp;
 102         int rc;
 103
 104         /* want handles we can use to read with first
 105            in the list so we do not have to walk the
 106            list to search for one in prepare_write */
 107         if ((file->f_flags & O_ACCMODE) == O_WRONLY) {
 108                 list_add_tail(&pCifsFile->flist,
 109                               &pCifsInode->openFileList);
 110         } else {
 111                 list_add(&pCifsFile->flist,
 112                          &pCifsInode->openFileList);
 113         }
 114         write_unlock(&GlobalSMBSeslock);
 115         if (pCifsInode->clientCanCacheRead) {
 116                 /* we have the inode open somewhere else
 117                    no need to discard cache data */
 118                 goto client_can_cache;
 119         }
 120
 121         /* BB need same check in cifs_create too? */
 122         /* if not oplocked, invalidate inode pages if mtime or file
 123            size changed */
 124         temp = cifs_NTtimeToUnix(le64_to_cpu(buf->LastWriteTime));
 125         if (timespec_equal(&file->f_path.dentry->d_inode->i_mtime, &temp) &&
 126                            (file->f_path.dentry->d_inode->i_size ==
 127                             (loff_t)le64_to_cpu(buf->EndOfFile))) {
 128                 cFYI(1, ("inode unchanged on server"));
 129         } else {
 130                 if (file->f_path.dentry->d_inode->i_mapping) {
 131                 /* BB no need to lock inode until after invalidate
 132                    since namei code should already have it locked? */
 133                         filemap_write_and_wait(file->f_path.dentry->d_inode->i_mapping);
 134                 }
 135                 cFYI(1, ("invalidating remote inode since open detected it "
 136                          "changed"));
 137                 invalidate_remote_inode(file->f_path.dentry->d_inode);
 138         }
 139
 140 client_can_cache:
 141         if (pTcon->unix_ext)
 142                 rc = cifs_get_inode_info_unix(&file->f_path.dentry->d_inode,
 143                         full_path, inode->i_sb, xid);
 144         else
 145                 rc = cifs_get_inode_info(&file->f_path.dentry->d_inode,
 146                         full_path, buf, inode->i_sb, xid);
 147
 148         if ((*oplock & 0xF) == OPLOCK_EXCLUSIVE) {
 149                 pCifsInode->clientCanCacheAll = TRUE;
 150                 pCifsInode->clientCanCacheRead = TRUE;
 151                 cFYI(1, ("Exclusive Oplock granted on inode %p",
 152                          file->f_path.dentry->d_inode));
 153         } else if ((*oplock & 0xF) == OPLOCK_READ)
 154                 pCifsInode->clientCanCacheRead = TRUE;
 155
 156         return rc;
 157 }
 158
 159 int cifs_open(struct inode *inode, struct file *file)
 160 {
 161         int rc = -EACCES;
 162         int xid, oplock;
 163         struct cifs_sb_info *cifs_sb;
 164         struct cifsTconInfo *pTcon;
 165         struct cifsFileInfo *pCifsFile;
 166         struct cifsInodeInfo *pCifsInode;
 167         struct list_head *tmp;
 168         char *full_path = NULL;
 169         int desiredAccess;
 170         int disposition;
 171         __u16 netfid;
 172         FILE_ALL_INFO *buf = NULL;
 173
 174         xid = GetXid();
 175
 176         cifs_sb = CIFS_SB(inode->i_sb);
 177         pTcon = cifs_sb->tcon;
 178
 179         if (file->f_flags & O_CREAT) {
 180                 /* search inode for this file and fill in file->private_data */
 181                 pCifsInode = CIFS_I(file->f_path.dentry->d_inode);
 182                 read_lock(&GlobalSMBSeslock);
 183                 list_for_each(tmp, &pCifsInode->openFileList) {
 184                         pCifsFile = list_entry(tmp, struct cifsFileInfo,
 185                                                flist);
 186                         if ((pCifsFile->pfile == NULL) &&
 187                             (pCifsFile->pid == current->tgid)) {
 188                                 /* mode set in cifs_create */
 189
 190                                 /* needed for writepage */
 191                                 pCifsFile->pfile = file;
 192
 193                                 file->private_data = pCifsFile;
 194                                 break;
 195                         }
 196                 }
 197                 read_unlock(&GlobalSMBSeslock);
 198                 if (file->private_data != NULL) {
 199                         rc = 0;
 200                         FreeXid(xid);
 201                         return rc;
 202                 } else {
 203                         if (file->f_flags & O_EXCL)
 204                                 cERROR(1, ("could not find file instance for "
 205                                            "new file %p", file));
 206                 }
 207         }
 208
 209         full_path = build_path_from_dentry(file->f_path.dentry);
 210         if (full_path == NULL) {
 211                 FreeXid(xid);
 212                 return -ENOMEM;
 213         }
 214
 215         cFYI(1, ("inode = 0x%p file flags are 0x%x for %s",
 216                  inode, file->f_flags, full_path));
 217         desiredAccess = cifs_convert_flags(file->f_flags);
 218
 219 /*********************************************************************
 220  *  open flag mapping table:
 221  *
 222  *      POSIX Flag            CIFS Disposition
 223  *      ----------            ----------------
 224  *      O_CREAT               FILE_OPEN_IF
 225  *      O_CREAT | O_EXCL      FILE_CREATE
 226  *      O_CREAT | O_TRUNC     FILE_OVERWRITE_IF
 227  *      O_TRUNC               FILE_OVERWRITE
 228  *      none of the above     FILE_OPEN
 229  *
 230  *      Note that there is not a direct match between disposition
 231  *      FILE_SUPERSEDE (ie create whether or not file exists although
 232  *      O_CREAT | O_TRUNC is similar but truncates the existing
 233  *      file rather than creating a new file as FILE_SUPERSEDE does
 234  *      (which uses the attributes / metadata passed in on open call)
 235  *?
 236  *?  O_SYNC is a reasonable match to CIFS writethrough flag
 237  *?  and the read write flags match reasonably.  O_LARGEFILE
 238  *?  is irrelevant because largefile support is always used
 239  *?  by this client. Flags O_APPEND, O_DIRECT, O_DIRECTORY,
 240  *       O_FASYNC, O_NOFOLLOW, O_NONBLOCK need further investigation
 241  *********************************************************************/
 242
 243         disposition = cifs_get_disposition(file->f_flags);
 244
 245         if (oplockEnabled)
 246                 oplock = REQ_OPLOCK;
 247         else
 248                 oplock = FALSE;
 249
 250         /* BB pass O_SYNC flag through on file attributes .. BB */
 251
 252         /* Also refresh inode by passing in file_info buf returned by SMBOpen
 253            and calling get_inode_info with returned buf (at least helps
 254            non-Unix server case) */
 255
 256         /* BB we can not do this if this is the second open of a file
 257            and the first handle has writebehind data, we might be
 258            able to simply do a filemap_fdatawrite/filemap_fdatawait first */
 259         buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
 260         if (!buf) {
 261                 rc = -ENOMEM;
 262                 goto out;
 263         }
 264
 265         if (cifs_sb->tcon->ses->capabilities & CAP_NT_SMBS)
 266                 rc = CIFSSMBOpen(xid, pTcon, full_path, disposition,
 267                          desiredAccess, CREATE_NOT_DIR, &netfid, &oplock, buf,
 268                          cifs_sb->local_nls, cifs_sb->mnt_cifs_flags
 269                                  & CIFS_MOUNT_MAP_SPECIAL_CHR);
 270         else
 271                 rc = -EIO; /* no NT SMB support fall into legacy open below */
 272
 273         if (rc == -EIO) {
 274                 /* Old server, try legacy style OpenX */
 275                 rc = SMBLegacyOpen(xid, pTcon, full_path, disposition,
 276                         desiredAccess, CREATE_NOT_DIR, &netfid, &oplock, buf,
 277                         cifs_sb->local_nls, cifs_sb->mnt_cifs_flags
 278                                 & CIFS_MOUNT_MAP_SPECIAL_CHR);
 279         }
 280         if (rc) {
 281                 cFYI(1, ("cifs_open returned 0x%x", rc));
 282                 goto out;
 283         }
 284         file->private_data =
 285                 kmalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
 286         if (file->private_data == NULL) {
 287                 rc = -ENOMEM;
 288                 goto out;
 289         }
 290         pCifsFile = cifs_init_private(file->private_data, inode, file, netfid);
 291         write_lock(&GlobalSMBSeslock);
 292         list_add(&pCifsFile->tlist, &pTcon->openFileList);
 293
 294         pCifsInode = CIFS_I(file->f_path.dentry->d_inode);
 295         if (pCifsInode) {
 296                 rc = cifs_open_inode_helper(inode, file, pCifsInode,
 297                                             pCifsFile, pTcon,
 298                                             &oplock, buf, full_path, xid);
 299         } else {
 300                 write_unlock(&GlobalSMBSeslock);
 301         }
 302
 303         if (oplock & CIFS_CREATE_ACTION) {
 304                 /* time to set mode which we can not set earlier due to
 305                    problems creating new read-only files */
 306                 if (pTcon->unix_ext) {
 307                         CIFSSMBUnixSetPerms(xid, pTcon, full_path,
 308                                             inode->i_mode,
 309                                             (__u64)-1, (__u64)-1, 0 /* dev */,
 310                                             cifs_sb->local_nls,
 311                                             cifs_sb->mnt_cifs_flags &
 312                                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
 313                 } else {
 314                         /* BB implement via Windows security descriptors eg
 315                            CIFSSMBWinSetPerms(xid, pTcon, full_path, mode,
 316                                               -1, -1, local_nls);
 317                            in the meantime could set r/o dos attribute when
 318                            perms are eg: mode & 0222 == 0 */
 319                 }
 320         }
 321
 322 out:
 323         kfree(buf);
 324         kfree(full_path);
 325         FreeXid(xid);
 326         return rc;
 327 }
 328
 329 /* Try to reacquire byte range locks that were released when session */
 330 /* to server was lost */
 331 static int cifs_relock_file(struct cifsFileInfo *cifsFile)
 332 {
 333         int rc = 0;
 334
 335 /* BB list all locks open on this file and relock */
 336
 337         return rc;
 338 }
 339
 340 static int cifs_reopen_file(struct file *file, int can_flush)
 341 {
 342         int rc = -EACCES;
 343         int xid, oplock;
 344         struct cifs_sb_info *cifs_sb;
 345         struct cifsTconInfo *pTcon;
 346         struct cifsFileInfo *pCifsFile;
 347         struct cifsInodeInfo *pCifsInode;
 348         struct inode *inode;
 349         char *full_path = NULL;
 350         int desiredAccess;
 351         int disposition = FILE_OPEN;
 352         __u16 netfid;
 353
 354         if (file->private_data) {
 355                 pCifsFile = (struct cifsFileInfo *)file->private_data;
 356         } else
 357                 return -EBADF;
 358
 359         xid = GetXid();
 360         down(&pCifsFile->fh_sem);
 361         if (pCifsFile->invalidHandle == FALSE) {
 362                 up(&pCifsFile->fh_sem);
 363                 FreeXid(xid);
 364                 return 0;
 365         }
 366
 367         if (file->f_path.dentry == NULL) {
 368                 cERROR(1, ("no valid name if dentry freed"));
 369                 dump_stack();
 370                 rc = -EBADF;
 371                 goto reopen_error_exit;
 372         }
 373
 374         inode = file->f_path.dentry->d_inode;
 375         if (inode == NULL) {
 376                 cERROR(1, ("inode not valid"));
 377                 dump_stack();
 378                 rc = -EBADF;
 379                 goto reopen_error_exit;
 380         }
 381
 382         cifs_sb = CIFS_SB(inode->i_sb);
 383         pTcon = cifs_sb->tcon;
 384
 385 /* can not grab rename sem here because various ops, including
 386    those that already have the rename sem can end up causing writepage
 387    to get called and if the server was down that means we end up here,
 388    and we can never tell if the caller already has the rename_sem */
 389         full_path = build_path_from_dentry(file->f_path.dentry);
 390         if (full_path == NULL) {
 391                 rc = -ENOMEM;
 392 reopen_error_exit:
 393                 up(&pCifsFile->fh_sem);
 394                 FreeXid(xid);
 395                 return rc;
 396         }
 397
 398         cFYI(1, ("inode = 0x%p file flags 0x%x for %s",
 399                  inode, file->f_flags, full_path));
 400         desiredAccess = cifs_convert_flags(file->f_flags);
 401
 402         if (oplockEnabled)
 403                 oplock = REQ_OPLOCK;
 404         else
 405                 oplock = FALSE;
 406
 407         /* Can not refresh inode by passing in file_info buf to be returned
 408            by SMBOpen and then calling get_inode_info with returned buf
 409            since file might have write behind data that needs to be flushed
 410            and server version of file size can be stale. If we knew for sure
 411            that inode was not dirty locally we could do this */
 412
 413         rc = CIFSSMBOpen(xid, pTcon, full_path, disposition, desiredAccess,
 414                          CREATE_NOT_DIR, &netfid, &oplock, NULL,
 415                          cifs_sb->local_nls, cifs_sb->mnt_cifs_flags &
 416                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
 417         if (rc) {
 418                 up(&pCifsFile->fh_sem);
 419                 cFYI(1, ("cifs_open returned 0x%x", rc));
 420                 cFYI(1, ("oplock: %d", oplock));
 421         } else {
 422                 pCifsFile->netfid = netfid;
 423                 pCifsFile->invalidHandle = FALSE;
 424                 up(&pCifsFile->fh_sem);
 425                 pCifsInode = CIFS_I(inode);
 426                 if (pCifsInode) {
 427                         if (can_flush) {
 428                                 filemap_write_and_wait(inode->i_mapping);
 429                         /* temporarily disable caching while we
 430                            go to server to get inode info */
 431                                 pCifsInode->clientCanCacheAll = FALSE;
 432                                 pCifsInode->clientCanCacheRead = FALSE;
 433                                 if (pTcon->unix_ext)
 434                                         rc = cifs_get_inode_info_unix(&inode,
 435                                                 full_path, inode->i_sb, xid);
 436                                 else
 437                                         rc = cifs_get_inode_info(&inode,
 438                                                 full_path, NULL, inode->i_sb,
 439                                                 xid);
 440                         } /* else we are writing out data to server already
 441                              and could deadlock if we tried to flush data, and
 442                              since we do not know if we have data that would
 443                              invalidate the current end of file on the server
 444                              we can not go to the server to get the new inod
 445                              info */
 446                         if ((oplock & 0xF) == OPLOCK_EXCLUSIVE) {
 447                                 pCifsInode->clientCanCacheAll = TRUE;
 448                                 pCifsInode->clientCanCacheRead = TRUE;
 449                                 cFYI(1, ("Exclusive Oplock granted on inode %p",
 450                                          file->f_path.dentry->d_inode));
 451                         } else if ((oplock & 0xF) == OPLOCK_READ) {
 452                                 pCifsInode->clientCanCacheRead = TRUE;
 453                                 pCifsInode->clientCanCacheAll = FALSE;
 454                         } else {
 455                                 pCifsInode->clientCanCacheRead = FALSE;
 456                                 pCifsInode->clientCanCacheAll = FALSE;
 457                         }
 458                         cifs_relock_file(pCifsFile);
 459                 }
 460         }
 461
 462         kfree(full_path);
 463         FreeXid(xid);
 464         return rc;
 465 }
 466
 467 int cifs_close(struct inode *inode, struct file *file)
 468 {
 469         int rc = 0;
 470         int xid;
 471         struct cifs_sb_info *cifs_sb;
 472         struct cifsTconInfo *pTcon;
 473         struct cifsFileInfo *pSMBFile =
 474                 (struct cifsFileInfo *)file->private_data;
 475
 476         xid = GetXid();
 477
 478         cifs_sb = CIFS_SB(inode->i_sb);
 479         pTcon = cifs_sb->tcon;
 480         if (pSMBFile) {
 481                 struct cifsLockInfo *li, *tmp;
 482
 483                 pSMBFile->closePend = TRUE;
 484                 if (pTcon) {
 485                         /* no sense reconnecting to close a file that is
 486                            already closed */
 487                         if (pTcon->tidStatus != CifsNeedReconnect) {
 488                                 int timeout = 2;
 489                                 while ((atomic_read(&pSMBFile->wrtPending) != 0)
 490                                          && (timeout < 1000) ) {
 491                                         /* Give write a better chance to get to
 492                                         server ahead of the close.  We do not
 493                                         want to add a wait_q here as it would
 494                                         increase the memory utilization as
 495                                         the struct would be in each open file,
 496                                         but this should give enough time to
 497                                         clear the socket */
 498 #ifdef CONFIG_CIFS_DEBUG2
 499                                         cFYI(1, ("close delay, write pending"));
 500 #endif /* DEBUG2 */
 501                                         msleep(timeout);
 502                                         timeout *= 4;
 503                                 }
 504                                 if (atomic_read(&pSMBFile->wrtPending))
 505                                         cERROR(1,
 506                                                 ("close with pending writes"));
 507                                 rc = CIFSSMBClose(xid, pTcon,
 508                                                   pSMBFile->netfid);
 509                         }
 510                 }
 511
 512                 /* Delete any outstanding lock records.
 513                    We'll lose them when the file is closed anyway. */
 514                 mutex_lock(&pSMBFile->lock_mutex);
 515                 list_for_each_entry_safe(li, tmp, &pSMBFile->llist, llist) {
 516                         list_del(&li->llist);
 517                         kfree(li);
 518                 }
 519                 mutex_unlock(&pSMBFile->lock_mutex);
 520
 521                 write_lock(&GlobalSMBSeslock);
 522                 list_del(&pSMBFile->flist);
 523                 list_del(&pSMBFile->tlist);
 524                 write_unlock(&GlobalSMBSeslock);
 525                 kfree(pSMBFile->search_resume_name);
 526                 kfree(file->private_data);
 527                 file->private_data = NULL;
 528         } else
 529                 rc = -EBADF;
 530
 531         if (list_empty(&(CIFS_I(inode)->openFileList))) {
 532                 cFYI(1, ("closing last open instance for inode %p", inode));
 533                 /* if the file is not open we do not know if we can cache info
 534                    on this inode, much less write behind and read ahead */
 535                 CIFS_I(inode)->clientCanCacheRead = FALSE;
 536                 CIFS_I(inode)->clientCanCacheAll  = FALSE;
 537         }
 538         if ((rc == 0) && CIFS_I(inode)->write_behind_rc)
 539                 rc = CIFS_I(inode)->write_behind_rc;
 540         FreeXid(xid);
 541         return rc;
 542 }
 543
 544 int cifs_closedir(struct inode *inode, struct file *file)
 545 {
 546         int rc = 0;
 547         int xid;
 548         struct cifsFileInfo *pCFileStruct =
 549             (struct cifsFileInfo *)file->private_data;
 550         char *ptmp;
 551
 552         cFYI(1, ("Closedir inode = 0x%p", inode));
 553
 554         xid = GetXid();
 555
 556         if (pCFileStruct) {
 557                 struct cifsTconInfo *pTcon;
 558                 struct cifs_sb_info *cifs_sb =
 559                         CIFS_SB(file->f_path.dentry->d_sb);
 560
 561                 pTcon = cifs_sb->tcon;
 562
 563                 cFYI(1, ("Freeing private data in close dir"));
 564                 if ((pCFileStruct->srch_inf.endOfSearch == FALSE) &&
 565                    (pCFileStruct->invalidHandle == FALSE)) {
 566                         pCFileStruct->invalidHandle = TRUE;
 567                         rc = CIFSFindClose(xid, pTcon, pCFileStruct->netfid);
 568                         cFYI(1, ("Closing uncompleted readdir with rc %d",
 569                                  rc));
 570                         /* not much we can do if it fails anyway, ignore rc */
 571                         rc = 0;
 572                 }
 573                 ptmp = pCFileStruct->srch_inf.ntwrk_buf_start;
 574                 if (ptmp) {
 575                         cFYI(1, ("closedir free smb buf in srch struct"));
 576                         pCFileStruct->srch_inf.ntwrk_buf_start = NULL;
 577                         if (pCFileStruct->srch_inf.smallBuf)
 578                                 cifs_small_buf_release(ptmp);
 579                         else
 580                                 cifs_buf_release(ptmp);
 581                 }
 582                 ptmp = pCFileStruct->search_resume_name;
 583                 if (ptmp) {
 584                         cFYI(1, ("closedir free resume name"));
 585                         pCFileStruct->search_resume_name = NULL;
 586                         kfree(ptmp);
 587                 }
 588                 kfree(file->private_data);
 589                 file->private_data = NULL;
 590         }
 591         /* BB can we lock the filestruct while this is going on? */
 592         FreeXid(xid);
 593         return rc;
 594 }
 595
 596 static int store_file_lock(struct cifsFileInfo *fid, __u64 len,
 597                                 __u64 offset, __u8 lockType)
 598 {
 599         struct cifsLockInfo *li =
 600                 kmalloc(sizeof(struct cifsLockInfo), GFP_KERNEL);
 601         if (li == NULL)
 602                 return -ENOMEM;
 603         li->offset = offset;
 604         li->length = len;
 605         li->type = lockType;
 606         mutex_lock(&fid->lock_mutex);
 607         list_add(&li->llist, &fid->llist);
 608         mutex_unlock(&fid->lock_mutex);
 609         return 0;
 610 }
 611
 612 int cifs_lock(struct file *file, int cmd, struct file_lock *pfLock)
 613 {
 614         int rc, xid;
 615         __u32 numLock = 0;
 616         __u32 numUnlock = 0;
 617         __u64 length;
 618         int wait_flag = FALSE;
 619         struct cifs_sb_info *cifs_sb;
 620         struct cifsTconInfo *pTcon;
 621         __u16 netfid;
 622         __u8 lockType = LOCKING_ANDX_LARGE_FILES;
 623         int posix_locking;
 624
 625         length = 1 + pfLock->fl_end - pfLock->fl_start;
 626         rc = -EACCES;
 627         xid = GetXid();
 628
 629         cFYI(1, ("Lock parm: 0x%x flockflags: "
 630                  "0x%x flocktype: 0x%x start: %lld end: %lld",
 631                 cmd, pfLock->fl_flags, pfLock->fl_type, pfLock->fl_start,
 632                 pfLock->fl_end));
 633
 634         if (pfLock->fl_flags & FL_POSIX)
 635                 cFYI(1, ("Posix"));
 636         if (pfLock->fl_flags & FL_FLOCK)
 637                 cFYI(1, ("Flock"));
 638         if (pfLock->fl_flags & FL_SLEEP) {
 639                 cFYI(1, ("Blocking lock"));
 640                 wait_flag = TRUE;
 641         }
 642         if (pfLock->fl_flags & FL_ACCESS)
 643                 cFYI(1, ("Process suspended by mandatory locking - "
 644                          "not implemented yet"));
 645         if (pfLock->fl_flags & FL_LEASE)
 646                 cFYI(1, ("Lease on file - not implemented yet"));
 647         if (pfLock->fl_flags &
 648             (~(FL_POSIX | FL_FLOCK | FL_SLEEP | FL_ACCESS | FL_LEASE)))
 649                 cFYI(1, ("Unknown lock flags 0x%x", pfLock->fl_flags));
 650
 651         if (pfLock->fl_type == F_WRLCK) {
 652                 cFYI(1, ("F_WRLCK "));
 653                 numLock = 1;
 654         } else if (pfLock->fl_type == F_UNLCK) {
 655                 cFYI(1, ("F_UNLCK"));
 656                 numUnlock = 1;
 657                 /* Check if unlock includes more than
 658                 one lock range */
 659         } else if (pfLock->fl_type == F_RDLCK) {
 660                 cFYI(1, ("F_RDLCK"));
 661                 lockType |= LOCKING_ANDX_SHARED_LOCK;
 662                 numLock = 1;
 663         } else if (pfLock->fl_type == F_EXLCK) {
 664                 cFYI(1, ("F_EXLCK"));
 665                 numLock = 1;
 666         } else if (pfLock->fl_type == F_SHLCK) {
 667                 cFYI(1, ("F_SHLCK"));
 668                 lockType |= LOCKING_ANDX_SHARED_LOCK;
 669                 numLock = 1;
 670         } else
 671                 cFYI(1, ("Unknown type of lock"));
 672
 673         cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
 674         pTcon = cifs_sb->tcon;
 675
 676         if (file->private_data == NULL) {
 677                 FreeXid(xid);
 678                 return -EBADF;
 679         }
 680         netfid = ((struct cifsFileInfo *)file->private_data)->netfid;
 681
 682         posix_locking = (cifs_sb->tcon->ses->capabilities & CAP_UNIX) &&
 683                         (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(cifs_sb->tcon->fsUnixInfo.Capability));
 684
 685         /* BB add code here to normalize offset and length to
 686         account for negative length which we can not accept over the
 687         wire */
 688         if (IS_GETLK(cmd)) {
 689                 if (posix_locking) {
 690                         int posix_lock_type;
 691                         if (lockType & LOCKING_ANDX_SHARED_LOCK)
 692                                 posix_lock_type = CIFS_RDLCK;
 693                         else
 694                                 posix_lock_type = CIFS_WRLCK;
 695                         rc = CIFSSMBPosixLock(xid, pTcon, netfid, 1 /* get */,
 696                                         length, pfLock,
 697                                         posix_lock_type, wait_flag);
 698                         FreeXid(xid);
 699                         return rc;
 700                 }
 701
 702                 /* BB we could chain these into one lock request BB */
 703                 rc = CIFSSMBLock(xid, pTcon, netfid, length, pfLock->fl_start,
 704                                  0, 1, lockType, 0 /* wait flag */ );
 705                 if (rc == 0) {
 706                         rc = CIFSSMBLock(xid, pTcon, netfid, length,
 707                                          pfLock->fl_start, 1 /* numUnlock */ ,
 708                                          0 /* numLock */ , lockType,
 709                                          0 /* wait flag */ );
 710                         pfLock->fl_type = F_UNLCK;
 711                         if (rc != 0)
 712                                 cERROR(1, ("Error unlocking previously locked "
 713                                            "range %d during test of lock", rc));
 714                         rc = 0;
 715
 716                 } else {
 717                         /* if rc == ERR_SHARING_VIOLATION ? */
 718                         rc = 0; /* do not change lock type to unlock
 719                                    since range in use */
 720                 }
 721
 722                 FreeXid(xid);
 723                 return rc;
 724         }
 725
 726         if (!numLock && !numUnlock) {
 727                 /* if no lock or unlock then nothing
 728                 to do since we do not know what it is */
 729                 FreeXid(xid);
 730                 return -EOPNOTSUPP;
 731         }
 732
 733         if (posix_locking) {
 734                 int posix_lock_type;
 735                 if (lockType & LOCKING_ANDX_SHARED_LOCK)
 736                         posix_lock_type = CIFS_RDLCK;
 737                 else
 738                         posix_lock_type = CIFS_WRLCK;
 739
 740                 if (numUnlock == 1)
 741                         posix_lock_type = CIFS_UNLCK;
 742
 743                 rc = CIFSSMBPosixLock(xid, pTcon, netfid, 0 /* set */,
 744                                       length, pfLock,
 745                                       posix_lock_type, wait_flag);
 746         } else {
 747                 struct cifsFileInfo *fid =
 748                         (struct cifsFileInfo *)file->private_data;
 749
 750                 if (numLock) {
 751                         rc = CIFSSMBLock(xid, pTcon, netfid, length,
 752                                         pfLock->fl_start,
 753                                         0, numLock, lockType, wait_flag);
 754
 755                         if (rc == 0) {
 756                                 /* For Windows locks we must store them. */
 757                                 rc = store_file_lock(fid, length,
 758                                                 pfLock->fl_start, lockType);
 759                         }
 760                 } else if (numUnlock) {
 761                         /* For each stored lock that this unlock overlaps
 762                            completely, unlock it. */
 763                         int stored_rc = 0;
 764                         struct cifsLockInfo *li, *tmp;
 765
 766                         rc = 0;
 767                         mutex_lock(&fid->lock_mutex);
 768                         list_for_each_entry_safe(li, tmp, &fid->llist, llist) {
 769                                 if (pfLock->fl_start <= li->offset &&
 770                                                 length >= li->length) {
 771                                         stored_rc = CIFSSMBLock(xid, pTcon,
 772                                                         netfid,
 773                                                         li->length, li->offset,
 774                                                         1, 0, li->type, FALSE);
 775                                         if (stored_rc)
 776                                                 rc = stored_rc;
 777
 778                                         list_del(&li->llist);
 779                                         kfree(li);
 780                                 }
 781                         }
 782                         mutex_unlock(&fid->lock_mutex);
 783                 }
 784         }
 785
 786         if (pfLock->fl_flags & FL_POSIX)
 787                 posix_lock_file_wait(file, pfLock);
 788         FreeXid(xid);
 789         return rc;
 790 }
 791
 792 ssize_t cifs_user_write(struct file *file, const char __user *write_data,
 793         size_t write_size, loff_t *poffset)
 794 {
 795         int rc = 0;
 796         unsigned int bytes_written = 0;
 797         unsigned int total_written;
 798         struct cifs_sb_info *cifs_sb;
 799         struct cifsTconInfo *pTcon;
 800         int xid, long_op;
 801         struct cifsFileInfo *open_file;
 802
 803         cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
 804
 805         pTcon = cifs_sb->tcon;
 806
 807         /* cFYI(1,
 808            (" write %d bytes to offset %lld of %s", write_size,
 809            *poffset, file->f_path.dentry->d_name.name)); */
 810
 811         if (file->private_data == NULL)
 812                 return -EBADF;
 813         open_file = (struct cifsFileInfo *) file->private_data;
 814
 815         xid = GetXid();
 816
 817         if (*poffset > file->f_path.dentry->d_inode->i_size)
 818                 long_op = 2; /* writes past end of file can take a long time */
 819         else
 820                 long_op = 1;
 821
 822         for (total_written = 0; write_size > total_written;
 823              total_written += bytes_written) {
 824                 rc = -EAGAIN;
 825                 while (rc == -EAGAIN) {
 826                         if (file->private_data == NULL) {
 827                                 /* file has been closed on us */
 828                                 FreeXid(xid);
 829                         /* if we have gotten here we have written some data
 830                            and blocked, and the file has been freed on us while
 831                            we blocked so return what we managed to write */
 832                                 return total_written;
 833                         }
 834                         if (open_file->closePend) {
 835                                 FreeXid(xid);
 836                                 if (total_written)
 837                                         return total_written;
 838                                 else
 839                                         return -EBADF;
 840                         }
 841                         if (open_file->invalidHandle) {
 842                                 /* we could deadlock if we called
 843                                    filemap_fdatawait from here so tell
 844                                    reopen_file not to flush data to server
 845                                    now */
 846                                 rc = cifs_reopen_file(file, FALSE);
 847                                 if (rc != 0)
 848                                         break;
 849                         }
 850
 851                         rc = CIFSSMBWrite(xid, pTcon,
 852                                 open_file->netfid,
 853                                 min_t(const int, cifs_sb->wsize,
 854                                       write_size - total_written),
 855                                 *poffset, &bytes_written,
 856                                 NULL, write_data + total_written, long_op);
 857                 }
 858                 if (rc || (bytes_written == 0)) {
 859                         if (total_written)
 860                                 break;
 861                         else {
 862                                 FreeXid(xid);
 863                                 return rc;
 864                         }
 865                 } else
 866                         *poffset += bytes_written;
 867                 long_op = FALSE; /* subsequent writes fast -
 868                                     15 seconds is plenty */
 869         }
 870
 871         cifs_stats_bytes_written(pTcon, total_written);
 872
 873         /* since the write may have blocked check these pointers again */
 874         if ((file->f_path.dentry) && (file->f_path.dentry->d_inode)) {
 875                 struct inode *inode = file->f_path.dentry->d_inode;
 876 /* Do not update local mtime - server will set its actual value on write
 877  *              inode->i_ctime = inode->i_mtime =
 878  *                      current_fs_time(inode->i_sb);*/
 879                 if (total_written > 0) {
 880                         spin_lock(&inode->i_lock);
 881                         if (*poffset > file->f_path.dentry->d_inode->i_size)
 882                                 i_size_write(file->f_path.dentry->d_inode,
 883                                         *poffset);
 884                         spin_unlock(&inode->i_lock);
 885                 }
 886                 mark_inode_dirty_sync(file->f_path.dentry->d_inode);
 887         }
 888         FreeXid(xid);
 889         return total_written;
 890 }
 891
 892 static ssize_t cifs_write(struct file *file, const char *write_data,
 893         size_t write_size, loff_t *poffset)
 894 {
 895         int rc = 0;
 896         unsigned int bytes_written = 0;
 897         unsigned int total_written;
 898         struct cifs_sb_info *cifs_sb;
 899         struct cifsTconInfo *pTcon;
 900         int xid, long_op;
 901         struct cifsFileInfo *open_file;
 902
 903         cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
 904
 905         pTcon = cifs_sb->tcon;
 906
 907         cFYI(1, ("write %zd bytes to offset %lld of %s", write_size,
 908            *poffset, file->f_path.dentry->d_name.name));
 909
 910         if (file->private_data == NULL)
 911                 return -EBADF;
 912         open_file = (struct cifsFileInfo *)file->private_data;
 913
 914         xid = GetXid();
 915
 916         if (*poffset > file->f_path.dentry->d_inode->i_size)
 917                 long_op = 2; /* writes past end of file can take a long time */
 918         else
 919                 long_op = 1;
 920
 921         for (total_written = 0; write_size > total_written;
 922              total_written += bytes_written) {
 923                 rc = -EAGAIN;
 924                 while (rc == -EAGAIN) {
 925                         if (file->private_data == NULL) {
 926                                 /* file has been closed on us */
 927                                 FreeXid(xid);
 928                         /* if we have gotten here we have written some data
 929                            and blocked, and the file has been freed on us
 930                            while we blocked so return what we managed to
 931                            write */
 932                                 return total_written;
 933                         }
 934                         if (open_file->closePend) {
 935                                 FreeXid(xid);
 936                                 if (total_written)
 937                                         return total_written;
 938                                 else
 939                                         return -EBADF;
 940                         }
 941                         if (open_file->invalidHandle) {
 942                                 /* we could deadlock if we called
 943                                    filemap_fdatawait from here so tell
 944                                    reopen_file not to flush data to
 945                                    server now */
 946                                 rc = cifs_reopen_file(file, FALSE);
 947                                 if (rc != 0)
 948                                         break;
 949                         }
 950                         if (experimEnabled || (pTcon->ses->server &&
 951                                 ((pTcon->ses->server->secMode &
 952                                 (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED))
 953                                 == 0))) {
 954                                 struct kvec iov[2];
 955                                 unsigned int len;
 956
 957                                 len = min((size_t)cifs_sb->wsize,
 958                                           write_size - total_written);
 959                                 /* iov[0] is reserved for smb header */
 960                                 iov[1].iov_base = (char *)write_data +
 961                                                   total_written;
 962                                 iov[1].iov_len = len;
 963                                 rc = CIFSSMBWrite2(xid, pTcon,
 964                                                 open_file->netfid, len,
 965                                                 *poffset, &bytes_written,
 966                                                 iov, 1, long_op);
 967                         } else
 968                                 rc = CIFSSMBWrite(xid, pTcon,
 969                                          open_file->netfid,
 970                                          min_t(const int, cifs_sb->wsize,
 971                                                write_size - total_written),
 972                                          *poffset, &bytes_written,
 973                                          write_data + total_written,
 974                                          NULL, long_op);
 975                 }
 976                 if (rc || (bytes_written == 0)) {
 977                         if (total_written)
 978                                 break;
 979                         else {
 980                                 FreeXid(xid);
 981                                 return rc;
 982                         }
 983                 } else
 984                         *poffset += bytes_written;
 985                 long_op = FALSE; /* subsequent writes fast -
 986                                     15 seconds is plenty */
 987         }
 988
 989         cifs_stats_bytes_written(pTcon, total_written);
 990
 991         /* since the write may have blocked check these pointers again */
 992         if ((file->f_path.dentry) && (file->f_path.dentry->d_inode)) {
 993 /*BB We could make this contingent on superblock ATIME flag too */
 994 /*              file->f_path.dentry->d_inode->i_ctime =
 995                 file->f_path.dentry->d_inode->i_mtime = CURRENT_TIME;*/
 996                 if (total_written > 0) {
 997                         spin_lock(&file->f_path.dentry->d_inode->i_lock);
 998                         if (*poffset > file->f_path.dentry->d_inode->i_size)
 999                                 i_size_write(file->f_path.dentry->d_inode,
1000                                              *poffset);
1001                         spin_unlock(&file->f_path.dentry->d_inode->i_lock);
1002                 }
1003                 mark_inode_dirty_sync(file->f_path.dentry->d_inode);
1004         }
1005         FreeXid(xid);
1006         return total_written;
1007 }
1008
1009 struct cifsFileInfo *find_writable_file(struct cifsInodeInfo *cifs_inode)
1010 {
1011         struct cifsFileInfo *open_file;
1012         int rc;
1013
1014         /* Having a null inode here (because mapping->host was set to zero by
1015         the VFS or MM) should not happen but we had reports of on oops (due to
1016         it being zero) during stress testcases so we need to check for it */
1017
1018         if (cifs_inode == NULL) {
1019                 cERROR(1, ("Null inode passed to cifs_writeable_file"));
1020                 dump_stack();
1021                 return NULL;
1022         }
1023
1024         read_lock(&GlobalSMBSeslock);
1025         list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
1026                 if (open_file->closePend)
1027                         continue;
1028                 if (open_file->pfile &&
1029                     ((open_file->pfile->f_flags & O_RDWR) ||
1030                      (open_file->pfile->f_flags & O_WRONLY))) {
1031                         atomic_inc(&open_file->wrtPending);
1032                         read_unlock(&GlobalSMBSeslock);
1033                         if ((open_file->invalidHandle) &&
1034                            (!open_file->closePend) /* BB fixme -since the second clause can not be true remove it BB */) {
1035                                 rc = cifs_reopen_file(open_file->pfile, FALSE);
1036                                 /* if it fails, try another handle - might be */
1037                                 /* dangerous to hold up writepages with retry */
1038                                 if (rc) {
1039                                         cFYI(1,
1040                                               ("failed on reopen file in wp"));
1041                                         read_lock(&GlobalSMBSeslock);
1042                                         /* can not use this handle, no write
1043                                         pending on this one after all */
1044                                         atomic_dec
1045                                              (&open_file->wrtPending);
1046                                         continue;
1047                                 }
1048                         }
1049                         return open_file;
1050                 }
1051         }
1052         read_unlock(&GlobalSMBSeslock);
1053         return NULL;
1054 }
1055
1056 static int cifs_partialpagewrite(struct page *page, unsigned from, unsigned to)
1057 {
1058         struct address_space *mapping = page->mapping;
1059         loff_t offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
1060         char *write_data;
1061         int rc = -EFAULT;
1062         int bytes_written = 0;
1063         struct cifs_sb_info *cifs_sb;
1064         struct cifsTconInfo *pTcon;
1065         struct inode *inode;
1066         struct cifsFileInfo *open_file;
1067
1068         if (!mapping || !mapping->host)
1069                 return -EFAULT;
1070
1071         inode = page->mapping->host;
1072         cifs_sb = CIFS_SB(inode->i_sb);
1073         pTcon = cifs_sb->tcon;
1074
1075         offset += (loff_t)from;
1076         write_data = kmap(page);
1077         write_data += from;
1078
1079         if ((to > PAGE_CACHE_SIZE) || (from > to)) {
1080                 kunmap(page);
1081                 return -EIO;
1082         }
1083
1084         /* racing with truncate? */
1085         if (offset > mapping->host->i_size) {
1086                 kunmap(page);
1087                 return 0; /* don't care */
1088         }
1089
1090         /* check to make sure that we are not extending the file */
1091         if (mapping->host->i_size - offset < (loff_t)to)
1092                 to = (unsigned)(mapping->host->i_size - offset);
1093
1094         open_file = find_writable_file(CIFS_I(mapping->host));
1095         if (open_file) {
1096                 bytes_written = cifs_write(open_file->pfile, write_data,
1097                                            to-from, &offset);
1098                 atomic_dec(&open_file->wrtPending);
1099                 /* Does mm or vfs already set times? */
1100                 inode->i_atime = inode->i_mtime = current_fs_time(inode->i_sb);
1101                 if ((bytes_written > 0) && (offset)) {
1102                         rc = 0;
1103                 } else if (bytes_written < 0) {
1104                         if (rc != -EBADF)
1105                                 rc = bytes_written;
1106                 }
1107         } else {
1108                 cFYI(1, ("No writeable filehandles for inode"));
1109                 rc = -EIO;
1110         }
1111
1112         kunmap(page);
1113         return rc;
1114 }
1115
1116 static int cifs_writepages(struct address_space *mapping,
1117                            struct writeback_control *wbc)
1118 {
1119         struct backing_dev_info *bdi = mapping->backing_dev_info;
1120         unsigned int bytes_to_write;
1121         unsigned int bytes_written;
1122         struct cifs_sb_info *cifs_sb;
1123         int done = 0;
1124         pgoff_t end;
1125         pgoff_t index;
1126         int range_whole = 0;
1127         struct kvec *iov;
1128         int len;
1129         int n_iov = 0;
1130         pgoff_t next;
1131         int nr_pages;
1132         __u64 offset = 0;
1133         struct cifsFileInfo *open_file;
1134         struct page *page;
1135         struct pagevec pvec;
1136         int rc = 0;
1137         int scanned = 0;
1138         int xid;
1139
1140         cifs_sb = CIFS_SB(mapping->host->i_sb);
1141
1142         /*
1143          * If wsize is smaller that the page cache size, default to writing
1144          * one page at a time via cifs_writepage
1145          */
1146         if (cifs_sb->wsize < PAGE_CACHE_SIZE)
1147                 return generic_writepages(mapping, wbc);
1148
1149         if ((cifs_sb->tcon->ses) && (cifs_sb->tcon->ses->server))
1150                 if (cifs_sb->tcon->ses->server->secMode &
1151                                 (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED))
1152                         if (!experimEnabled)
1153                                 return generic_writepages(mapping, wbc);
1154
1155         iov = kmalloc(32 * sizeof(struct kvec), GFP_KERNEL);
1156         if (iov == NULL)
1157                 return generic_writepages(mapping, wbc);
1158
1159
1160         /*
1161          * BB: Is this meaningful for a non-block-device file system?
1162          * If it is, we should test it again after we do I/O
1163          */
1164         if (wbc->nonblocking && bdi_write_congested(bdi)) {
1165                 wbc->encountered_congestion = 1;
1166                 kfree(iov);
1167                 return 0;
1168         }
1169
1170         xid = GetXid();
1171
1172         pagevec_init(&pvec, 0);
1173         if (wbc->range_cyclic) {
1174                 index = mapping->writeback_index; /* Start from prev offset */
1175                 end = -1;
1176         } else {
1177                 index = wbc->range_start >> PAGE_CACHE_SHIFT;
1178                 end = wbc->range_end >> PAGE_CACHE_SHIFT;
1179                 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
1180                         range_whole = 1;
1181                 scanned = 1;
1182         }
1183 retry:
1184         while (!done && (index <= end) &&
1185                (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
1186                         PAGECACHE_TAG_DIRTY,
1187                         min(end - index, (pgoff_t)PAGEVEC_SIZE - 1) + 1))) {
1188                 int first;
1189                 unsigned int i;
1190
1191                 first = -1;
1192                 next = 0;
1193                 n_iov = 0;
1194                 bytes_to_write = 0;
1195
1196                 for (i = 0; i < nr_pages; i++) {
1197                         page = pvec.pages[i];
1198                         /*
1199                          * At this point we hold neither mapping->tree_lock nor
1200                          * lock on the page itself: the page may be truncated or
1201                          * invalidated (changing page->mapping to NULL), or even
1202                          * swizzled back from swapper_space to tmpfs file
1203                          * mapping
1204                          */
1205
1206                         if (first < 0)
1207                                 lock_page(page);
1208                         else if (TestSetPageLocked(page))
1209                                 break;
1210
1211                         if (unlikely(page->mapping != mapping)) {
1212                                 unlock_page(page);
1213                                 break;
1214                         }
1215
1216                         if (!wbc->range_cyclic && page->index > end) {
1217                                 done = 1;
1218                                 unlock_page(page);
1219                                 break;
1220                         }
1221
1222                         if (next && (page->index != next)) {
1223                                 /* Not next consecutive page */
1224                                 unlock_page(page);
1225                                 break;
1226                         }
1227
1228                         if (wbc->sync_mode != WB_SYNC_NONE)
1229                                 wait_on_page_writeback(page);
1230
1231                         if (PageWriteback(page) ||
1232                                         !clear_page_dirty_for_io(page)) {
1233                                 unlock_page(page);
1234                                 break;
1235                         }
1236
1237                         /*
1238                          * This actually clears the dirty bit in the radix tree.
1239                          * See cifs_writepage() for more commentary.
1240                          */
1241                         set_page_writeback(page);
1242
1243                         if (page_offset(page) >= mapping->host->i_size) {
1244                                 done = 1;
1245                                 unlock_page(page);
1246                                 end_page_writeback(page);
1247                                 break;
1248                         }
1249
1250                         /*
1251                          * BB can we get rid of this?  pages are held by pvec
1252                          */
1253                         page_cache_get(page);
1254
1255                         len = min(mapping->host->i_size - page_offset(page),
1256                                   (loff_t)PAGE_CACHE_SIZE);
1257
1258                         /* reserve iov[0] for the smb header */
1259                         n_iov++;
1260                         iov[n_iov].iov_base = kmap(page);
1261                         iov[n_iov].iov_len = len;
1262                         bytes_to_write += len;
1263
1264                         if (first < 0) {
1265                                 first = i;
1266                                 offset = page_offset(page);
1267                         }
1268                         next = page->index + 1;
1269                         if (bytes_to_write + PAGE_CACHE_SIZE > cifs_sb->wsize)
1270                                 break;
1271                 }
1272                 if (n_iov) {
1273                         /* Search for a writable handle every time we call
1274                          * CIFSSMBWrite2.  We can't rely on the last handle
1275                          * we used to still be valid
1276                          */
1277                         open_file = find_writable_file(CIFS_I(mapping->host));
1278                         if (!open_file) {
1279                                 cERROR(1, ("No writable handles for inode"));
1280                                 rc = -EBADF;
1281                         } else {
1282                                 rc = CIFSSMBWrite2(xid, cifs_sb->tcon,
1283                                                    open_file->netfid,
1284                                                    bytes_to_write, offset,
1285                                                    &bytes_written, iov, n_iov,
1286                                                    1);
1287                                 atomic_dec(&open_file->wrtPending);
1288                                 if (rc || bytes_written < bytes_to_write) {
1289                                         cERROR(1, ("Write2 ret %d, wrote %d",
1290                                                   rc, bytes_written));
1291                                         /* BB what if continued retry is
1292                                            requested via mount flags? */
1293                                         set_bit(AS_EIO, &mapping->flags);
1294                                 } else {
1295                                         cifs_stats_bytes_written(cifs_sb->tcon,
1296                                                                  bytes_written);
1297                                 }
1298                         }
1299                         for (i = 0; i < n_iov; i++) {
1300                                 page = pvec.pages[first + i];
1301                                 /* Should we also set page error on
1302                                 success rc but too little data written? */
1303                                 /* BB investigate retry logic on temporary
1304                                 server crash cases and how recovery works
1305                                 when page marked as error */
1306                                 if (rc)
1307                                         SetPageError(page);
1308                                 kunmap(page);
1309                                 unlock_page(page);
1310                                 end_page_writeback(page);
1311                                 page_cache_release(page);
1312                         }
1313                         if ((wbc->nr_to_write -= n_iov) <= 0)
1314                                 done = 1;
1315                         index = next;
1316                 }
1317                 pagevec_release(&pvec);
1318         }
1319         if (!scanned && !done) {
1320                 /*
1321                  * We hit the last page and there is more work to be done: wrap
1322                  * back to the start of the file
1323                  */
1324                 scanned = 1;
1325                 index = 0;
1326                 goto retry;
1327         }
1328         if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
1329                 mapping->writeback_index = index;
1330
1331         FreeXid(xid);
1332         kfree(iov);
1333         return rc;
1334 }
1335
1336 static int cifs_writepage(struct page *page, struct writeback_control *wbc)
1337 {
1338         int rc = -EFAULT;
1339         int xid;
1340
1341         xid = GetXid();
1342 /* BB add check for wbc flags */
1343         page_cache_get(page);
1344         if (!PageUptodate(page)) {
1345                 cFYI(1, ("ppw - page not up to date"));
1346         }
1347
1348         /*
1349          * Set the "writeback" flag, and clear "dirty" in the radix tree.
1350          *
1351          * A writepage() implementation always needs to do either this,
1352          * or re-dirty the page with "redirty_page_for_writepage()" in
1353          * the case of a failure.
1354          *
1355          * Just unlocking the page will cause the radix tree tag-bits
1356          * to fail to update with the state of the page correctly.
1357          */
1358         set_page_writeback(page);
1359         rc = cifs_partialpagewrite(page, 0, PAGE_CACHE_SIZE);
1360         SetPageUptodate(page); /* BB add check for error and Clearuptodate? */
1361         unlock_page(page);
1362         end_page_writeback(page);
1363         page_cache_release(page);
1364         FreeXid(xid);
1365         return rc;
1366 }
1367
1368 static int cifs_commit_write(struct file *file, struct page *page,
1369         unsigned offset, unsigned to)
1370 {
1371         int xid;
1372         int rc = 0;
1373         struct inode *inode = page->mapping->host;
1374         loff_t position = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
1375         char *page_data;
1376
1377         xid = GetXid();
1378         cFYI(1, ("commit write for page %p up to position %lld for %d",
1379                  page, position, to));
1380         spin_lock(&inode->i_lock);
1381         if (position > inode->i_size) {
1382                 i_size_write(inode, position);
1383         }
1384         spin_unlock(&inode->i_lock);
1385         if (!PageUptodate(page)) {
1386                 position =  ((loff_t)page->index << PAGE_CACHE_SHIFT) + offset;
1387                 /* can not rely on (or let) writepage write this data */
1388                 if (to < offset) {
1389                         cFYI(1, ("Illegal offsets, can not copy from %d to %d",
1390                                 offset, to));
1391                         FreeXid(xid);
1392                         return rc;
1393                 }
1394                 /* this is probably better than directly calling
1395                    partialpage_write since in this function the file handle is
1396                    known which we might as well leverage */
1397                 /* BB check if anything else missing out of ppw
1398                    such as updating last write time */
1399                 page_data = kmap(page);
1400                 rc = cifs_write(file, page_data + offset, to-offset,
1401                                 &position);
1402                 if (rc > 0)
1403                         rc = 0;
1404                 /* else if (rc < 0) should we set writebehind rc? */
1405                 kunmap(page);
1406         } else {
1407                 set_page_dirty(page);
1408         }
1409
1410         FreeXid(xid);
1411         return rc;
1412 }
1413
1414 int cifs_fsync(struct file *file, struct dentry *dentry, int datasync)
1415 {
1416         int xid;
1417         int rc = 0;
1418         struct inode *inode = file->f_path.dentry->d_inode;
1419
1420         xid = GetXid();
1421
1422         cFYI(1, ("Sync file - name: %s datasync: 0x%x",
1423                 dentry->d_name.name, datasync));
1424
1425         rc = filemap_fdatawrite(inode->i_mapping);
1426         if (rc == 0)
1427                 CIFS_I(inode)->write_behind_rc = 0;
1428         FreeXid(xid);
1429         return rc;
1430 }
1431
1432 /* static void cifs_sync_page(struct page *page)
1433 {
1434         struct address_space *mapping;
1435         struct inode *inode;
1436         unsigned long index = page->index;
1437         unsigned int rpages = 0;
1438         int rc = 0;
1439
1440         cFYI(1, ("sync page %p",page));
1441         mapping = page->mapping;
1442         if (!mapping)
1443                 return 0;
1444         inode = mapping->host;
1445         if (!inode)
1446                 return; */
1447
1448 /*      fill in rpages then
1449         result = cifs_pagein_inode(inode, index, rpages); */ /* BB finish */
1450
1451 /*      cFYI(1, ("rpages is %d for sync page of Index %ld", rpages, index));
1452
1453 #if 0
1454         if (rc < 0)
1455                 return rc;
1456         return 0;
1457 #endif
1458 } */
1459
1460 /*
1461  * As file closes, flush all cached write data for this inode checking
1462  * for write behind errors.
1463  */
1464 int cifs_flush(struct file *file, fl_owner_t id)
1465 {
1466         struct inode *inode = file->f_path.dentry->d_inode;
1467         int rc = 0;
1468
1469         /* Rather than do the steps manually:
1470            lock the inode for writing
1471            loop through pages looking for write behind data (dirty pages)
1472            coalesce into contiguous 16K (or smaller) chunks to write to server
1473            send to server (prefer in parallel)
1474            deal with writebehind errors
1475            unlock inode for writing
1476            filemapfdatawrite appears easier for the time being */
1477
1478         rc = filemap_fdatawrite(inode->i_mapping);
1479         if (!rc) /* reset wb rc if we were able to write out dirty pages */
1480                 CIFS_I(inode)->write_behind_rc = 0;
1481
1482         cFYI(1, ("Flush inode %p file %p rc %d", inode, file, rc));
1483
1484         return rc;
1485 }
1486
1487 ssize_t cifs_user_read(struct file *file, char __user *read_data,
1488         size_t read_size, loff_t *poffset)
1489 {
1490         int rc = -EACCES;
1491         unsigned int bytes_read = 0;
1492         unsigned int total_read = 0;
1493         unsigned int current_read_size;
1494         struct cifs_sb_info *cifs_sb;
1495         struct cifsTconInfo *pTcon;
1496         int xid;
1497         struct cifsFileInfo *open_file;
1498         char *smb_read_data;
1499         char __user *current_offset;
1500         struct smb_com_read_rsp *pSMBr;
1501
1502         xid = GetXid();
1503         cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
1504         pTcon = cifs_sb->tcon;
1505
1506         if (file->private_data == NULL) {
1507                 FreeXid(xid);
1508                 return -EBADF;
1509         }
1510         open_file = (struct cifsFileInfo *)file->private_data;
1511
1512         if ((file->f_flags & O_ACCMODE) == O_WRONLY) {
1513                 cFYI(1, ("attempting read on write only file instance"));
1514         }
1515         for (total_read = 0, current_offset = read_data;
1516              read_size > total_read;
1517              total_read += bytes_read, current_offset += bytes_read) {
1518                 current_read_size = min_t(const int, read_size - total_read,
1519                                           cifs_sb->rsize);
1520                 rc = -EAGAIN;
1521                 smb_read_data = NULL;
1522                 while (rc == -EAGAIN) {
1523                         int buf_type = CIFS_NO_BUFFER;
1524                         if ((open_file->invalidHandle) &&
1525                             (!open_file->closePend)) {
1526                                 rc = cifs_reopen_file(file, TRUE);
1527                                 if (rc != 0)
1528                                         break;
1529                         }
1530                         rc = CIFSSMBRead(xid, pTcon,
1531                                          open_file->netfid,
1532                                          current_read_size, *poffset,
1533                                          &bytes_read, &smb_read_data,
1534                                          &buf_type);
1535                         pSMBr = (struct smb_com_read_rsp *)smb_read_data;
1536                         if (smb_read_data) {
1537                                 if (copy_to_user(current_offset,
1538                                                 smb_read_data +
1539                                                 4 /* RFC1001 length field */ +
1540                                                 le16_to_cpu(pSMBr->DataOffset),
1541                                                 bytes_read)) {
1542                                         rc = -EFAULT;
1543                                 }
1544
1545                                 if (buf_type == CIFS_SMALL_BUFFER)
1546                                         cifs_small_buf_release(smb_read_data);
1547                                 else if (buf_type == CIFS_LARGE_BUFFER)
1548                                         cifs_buf_release(smb_read_data);
1549                                 smb_read_data = NULL;
1550                         }
1551                 }
1552                 if (rc || (bytes_read == 0)) {
1553                         if (total_read) {
1554                                 break;
1555                         } else {
1556                                 FreeXid(xid);
1557                                 return rc;
1558                         }
1559                 } else {
1560                         cifs_stats_bytes_read(pTcon, bytes_read);
1561                         *poffset += bytes_read;
1562                 }
1563         }
1564         FreeXid(xid);
1565         return total_read;
1566 }
1567
1568
1569 static ssize_t cifs_read(struct file *file, char *read_data, size_t read_size,
1570         loff_t *poffset)
1571 {
1572         int rc = -EACCES;
1573         unsigned int bytes_read = 0;
1574         unsigned int total_read;
1575         unsigned int current_read_size;
1576         struct cifs_sb_info *cifs_sb;
1577         struct cifsTconInfo *pTcon;
1578         int xid;
1579         char *current_offset;
1580         struct cifsFileInfo *open_file;
1581         int buf_type = CIFS_NO_BUFFER;
1582
1583         xid = GetXid();
1584         cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
1585         pTcon = cifs_sb->tcon;
1586
1587         if (file->private_data == NULL) {
1588                 FreeXid(xid);
1589                 return -EBADF;
1590         }
1591         open_file = (struct cifsFileInfo *)file->private_data;
1592
1593         if ((file->f_flags & O_ACCMODE) == O_WRONLY)
1594                 cFYI(1, ("attempting read on write only file instance"));
1595
1596         for (total_read = 0, current_offset = read_data;
1597              read_size > total_read;
1598              total_read += bytes_read, current_offset += bytes_read) {
1599                 current_read_size = min_t(const int, read_size - total_read,
1600                                           cifs_sb->rsize);
1601                 /* For windows me and 9x we do not want to request more
1602                 than it negotiated since it will refuse the read then */
1603                 if ((pTcon->ses) &&
1604                         !(pTcon->ses->capabilities & CAP_LARGE_FILES)) {
1605                         current_read_size = min_t(const int, current_read_size,
1606                                         pTcon->ses->server->maxBuf - 128);
1607                 }
1608                 rc = -EAGAIN;
1609                 while (rc == -EAGAIN) {
1610                         if ((open_file->invalidHandle) &&
1611                             (!open_file->closePend)) {
1612                                 rc = cifs_reopen_file(file, TRUE);
1613                                 if (rc != 0)
1614                                         break;
1615                         }
1616                         rc = CIFSSMBRead(xid, pTcon,
1617                                          open_file->netfid,
1618                                          current_read_size, *poffset,
1619                                          &bytes_read, &current_offset,
1620                                          &buf_type);
1621                 }
1622                 if (rc || (bytes_read == 0)) {
1623                         if (total_read) {
1624                                 break;
1625                         } else {
1626                                 FreeXid(xid);
1627                                 return rc;
1628                         }
1629                 } else {
1630                         cifs_stats_bytes_read(pTcon, total_read);
1631                         *poffset += bytes_read;
1632                 }
1633         }
1634         FreeXid(xid);
1635         return total_read;
1636 }
1637
1638 int cifs_file_mmap(struct file *file, struct vm_area_struct *vma)
1639 {
1640         struct dentry *dentry = file->f_path.dentry;
1641         int rc, xid;
1642
1643         xid = GetXid();
1644         rc = cifs_revalidate(dentry);
1645         if (rc) {
1646                 cFYI(1, ("Validation prior to mmap failed, error=%d", rc));
1647                 FreeXid(xid);
1648                 return rc;
1649         }
1650         rc = generic_file_mmap(file, vma);
1651         FreeXid(xid);
1652         return rc;
1653 }
1654
1655
1656 static void cifs_copy_cache_pages(struct address_space *mapping,
1657         struct list_head *pages, int bytes_read, char *data,
1658         struct pagevec *plru_pvec)
1659 {
1660         struct page *page;
1661         char *target;
1662
1663         while (bytes_read > 0) {
1664                 if (list_empty(pages))
1665                         break;
1666
1667                 page = list_entry(pages->prev, struct page, lru);
1668                 list_del(&page->lru);
1669
1670                 if (add_to_page_cache(page, mapping, page->index,
1671                                       GFP_KERNEL)) {
1672                         page_cache_release(page);
1673                         cFYI(1, ("Add page cache failed"));
1674                         data += PAGE_CACHE_SIZE;
1675                         bytes_read -= PAGE_CACHE_SIZE;
1676                         continue;
1677                 }
1678
1679                 target = kmap_atomic(page, KM_USER0);
1680
1681                 if (PAGE_CACHE_SIZE > bytes_read) {
1682                         memcpy(target, data, bytes_read);
1683                         /* zero the tail end of this partial page */
1684                         memset(target + bytes_read, 0,
1685                                PAGE_CACHE_SIZE - bytes_read);
1686                         bytes_read = 0;
1687                 } else {
1688                         memcpy(target, data, PAGE_CACHE_SIZE);
1689                         bytes_read -= PAGE_CACHE_SIZE;
1690                 }
1691                 kunmap_atomic(target, KM_USER0);
1692
1693                 flush_dcache_page(page);
1694                 SetPageUptodate(page);
1695                 unlock_page(page);
1696                 if (!pagevec_add(plru_pvec, page))
1697                         __pagevec_lru_add(plru_pvec);
1698                 data += PAGE_CACHE_SIZE;
1699         }
1700         return;
1701 }
1702
1703 static int cifs_readpages(struct file *file, struct address_space *mapping,
1704         struct list_head *page_list, unsigned num_pages)
1705 {
1706         int rc = -EACCES;
1707         int xid;
1708         loff_t offset;
1709         struct page *page;
1710         struct cifs_sb_info *cifs_sb;
1711         struct cifsTconInfo *pTcon;
1712         int bytes_read = 0;
1713         unsigned int read_size, i;
1714         char *smb_read_data = NULL;
1715         struct smb_com_read_rsp *pSMBr;
1716         struct pagevec lru_pvec;
1717         struct cifsFileInfo *open_file;
1718         int buf_type = CIFS_NO_BUFFER;
1719
1720         xid = GetXid();
1721         if (file->private_data == NULL) {
1722                 FreeXid(xid);
1723                 return -EBADF;
1724         }
1725         open_file = (struct cifsFileInfo *)file->private_data;
1726         cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
1727         pTcon = cifs_sb->tcon;
1728
1729         pagevec_init(&lru_pvec, 0);
1730 #ifdef CONFIG_CIFS_DEBUG2
1731                 cFYI(1, ("rpages: num pages %d", num_pages));
1732 #endif
1733         for (i = 0; i < num_pages; ) {
1734                 unsigned contig_pages;
1735                 struct page *tmp_page;
1736                 unsigned long expected_index;
1737
1738                 if (list_empty(page_list))
1739                         break;
1740
1741                 page = list_entry(page_list->prev, struct page, lru);
1742                 offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
1743
1744                 /* count adjacent pages that we will read into */
1745                 contig_pages = 0;
1746                 expected_index =
1747                         list_entry(page_list->prev, struct page, lru)->index;
1748                 list_for_each_entry_reverse(tmp_page, page_list, lru) {
1749                         if (tmp_page->index == expected_index) {
1750                                 contig_pages++;
1751                                 expected_index++;
1752                         } else
1753                                 break;
1754                 }
1755                 if (contig_pages + i >  num_pages)
1756                         contig_pages = num_pages - i;
1757
1758                 /* for reads over a certain size could initiate async
1759                    read ahead */
1760
1761                 read_size = contig_pages * PAGE_CACHE_SIZE;
1762                 /* Read size needs to be in multiples of one page */
1763                 read_size = min_t(const unsigned int, read_size,
1764                                   cifs_sb->rsize & PAGE_CACHE_MASK);
1765 #ifdef CONFIG_CIFS_DEBUG2
1766                 cFYI(1, ("rpages: read size 0x%x  contiguous pages %d",
1767                                 read_size, contig_pages));
1768 #endif
1769                 rc = -EAGAIN;
1770                 while (rc == -EAGAIN) {
1771                         if ((open_file->invalidHandle) &&
1772                             (!open_file->closePend)) {
1773                                 rc = cifs_reopen_file(file, TRUE);
1774                                 if (rc != 0)
1775                                         break;
1776                         }
1777
1778                         rc = CIFSSMBRead(xid, pTcon,
1779                                          open_file->netfid,
1780                                          read_size, offset,
1781                                          &bytes_read, &smb_read_data,
1782                                          &buf_type);
1783                         /* BB more RC checks ? */
1784                         if (rc == -EAGAIN) {
1785                                 if (smb_read_data) {
1786                                         if (buf_type == CIFS_SMALL_BUFFER)
1787                                                 cifs_small_buf_release(smb_read_data);
1788                                         else if (buf_type == CIFS_LARGE_BUFFER)
1789                                                 cifs_buf_release(smb_read_data);
1790                                         smb_read_data = NULL;
1791                                 }
1792                         }
1793                 }
1794                 if ((rc < 0) || (smb_read_data == NULL)) {
1795                         cFYI(1, ("Read error in readpages: %d", rc));
1796                         break;
1797                 } else if (bytes_read > 0) {
1798                         task_io_account_read(bytes_read);
1799                         pSMBr = (struct smb_com_read_rsp *)smb_read_data;
1800                         cifs_copy_cache_pages(mapping, page_list, bytes_read,
1801                                 smb_read_data + 4 /* RFC1001 hdr */ +
1802                                 le16_to_cpu(pSMBr->DataOffset), &lru_pvec);
1803
1804                         i +=  bytes_read >> PAGE_CACHE_SHIFT;
1805                         cifs_stats_bytes_read(pTcon, bytes_read);
1806                         if ((int)(bytes_read & PAGE_CACHE_MASK) != bytes_read) {
1807                                 i++; /* account for partial page */
1808
1809                                 /* server copy of file can have smaller size
1810                                    than client */
1811                                 /* BB do we need to verify this common case ?
1812                                    this case is ok - if we are at server EOF
1813                                    we will hit it on next read */
1814
1815                                 /* break; */
1816                         }
1817                 } else {
1818                         cFYI(1, ("No bytes read (%d) at offset %lld . "
1819                                  "Cleaning remaining pages from readahead list",
1820                                  bytes_read, offset));
1821                         /* BB turn off caching and do new lookup on
1822                            file size at server? */
1823                         break;
1824                 }
1825                 if (smb_read_data) {
1826                         if (buf_type == CIFS_SMALL_BUFFER)
1827                                 cifs_small_buf_release(smb_read_data);
1828                         else if (buf_type == CIFS_LARGE_BUFFER)
1829                                 cifs_buf_release(smb_read_data);
1830                         smb_read_data = NULL;
1831                 }
1832                 bytes_read = 0;
1833         }
1834
1835         pagevec_lru_add(&lru_pvec);
1836
1837 /* need to free smb_read_data buf before exit */
1838         if (smb_read_data) {
1839                 if (buf_type == CIFS_SMALL_BUFFER)
1840                         cifs_small_buf_release(smb_read_data);
1841                 else if (buf_type == CIFS_LARGE_BUFFER)
1842                         cifs_buf_release(smb_read_data);
1843                 smb_read_data = NULL;
1844         }
1845
1846         FreeXid(xid);
1847         return rc;
1848 }
1849
1850 static int cifs_readpage_worker(struct file *file, struct page *page,
1851         loff_t *poffset)
1852 {
1853         char *read_data;
1854         int rc;
1855
1856         page_cache_get(page);
1857         read_data = kmap(page);
1858         /* for reads over a certain size could initiate async read ahead */
1859
1860         rc = cifs_read(file, read_data, PAGE_CACHE_SIZE, poffset);
1861
1862         if (rc < 0)
1863                 goto io_error;
1864         else
1865                 cFYI(1, ("Bytes read %d", rc));
1866
1867         file->f_path.dentry->d_inode->i_atime =
1868                 current_fs_time(file->f_path.dentry->d_inode->i_sb);
1869
1870         if (PAGE_CACHE_SIZE > rc)
1871                 memset(read_data + rc, 0, PAGE_CACHE_SIZE - rc);
1872
1873         flush_dcache_page(page);
1874         SetPageUptodate(page);
1875         rc = 0;
1876
1877 io_error:
1878         kunmap(page);
1879         page_cache_release(page);
1880         return rc;
1881 }
1882
1883 static int cifs_readpage(struct file *file, struct page *page)
1884 {
1885         loff_t offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
1886         int rc = -EACCES;
1887         int xid;
1888
1889         xid = GetXid();
1890
1891         if (file->private_data == NULL) {
1892                 FreeXid(xid);
1893                 return -EBADF;
1894         }
1895
1896         cFYI(1, ("readpage %p at offset %d 0x%x\n",
1897                  page, (int)offset, (int)offset));
1898
1899         rc = cifs_readpage_worker(file, page, &offset);
1900
1901         unlock_page(page);
1902
1903         FreeXid(xid);
1904         return rc;
1905 }
1906
1907 /* We do not want to update the file size from server for inodes
1908    open for write - to avoid races with writepage extending
1909    the file - in the future we could consider allowing
1910    refreshing the inode only on increases in the file size
1911    but this is tricky to do without racing with writebehind
1912    page caching in the current Linux kernel design */
1913 int is_size_safe_to_change(struct cifsInodeInfo *cifsInode, __u64 end_of_file)
1914 {
1915         struct cifsFileInfo *open_file = NULL;
1916
1917         if (cifsInode)
1918                 open_file =  find_writable_file(cifsInode);
1919
1920         if (open_file) {
1921                 struct cifs_sb_info *cifs_sb;
1922
1923                 /* there is not actually a write pending so let
1924                 this handle go free and allow it to
1925                 be closable if needed */
1926                 atomic_dec(&open_file->wrtPending);
1927
1928                 cifs_sb = CIFS_SB(cifsInode->vfs_inode.i_sb);
1929                 if ( cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DIRECT_IO ) {
1930                         /* since no page cache to corrupt on directio
1931                         we can change size safely */
1932                         return 1;
1933                 }
1934
1935                 if (i_size_read(&cifsInode->vfs_inode) < end_of_file)
1936                         return 1;
1937
1938                 return 0;
1939         } else
1940                 return 1;
1941 }
1942
1943 static int cifs_prepare_write(struct file *file, struct page *page,
1944         unsigned from, unsigned to)
1945 {
1946         int rc = 0;
1947         loff_t i_size;
1948         loff_t offset;
1949
1950         cFYI(1, ("prepare write for page %p from %d to %d", page, from, to));
1951         if (PageUptodate(page))
1952                 return 0;
1953
1954         /* If we are writing a full page it will be up to date,
1955            no need to read from the server */
1956         if ((to == PAGE_CACHE_SIZE) && (from == 0)) {
1957                 SetPageUptodate(page);
1958                 return 0;
1959         }
1960
1961         offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
1962         i_size = i_size_read(page->mapping->host);
1963
1964         if ((offset >= i_size) ||
1965             ((from == 0) && (offset + to) >= i_size)) {
1966                 /*
1967                  * We don't need to read data beyond the end of the file.
1968                  * zero it, and set the page uptodate
1969                  */
1970                 simple_prepare_write(file, page, from, to);
1971                 SetPageUptodate(page);
1972         } else if ((file->f_flags & O_ACCMODE) != O_WRONLY) {
1973                 /* might as well read a page, it is fast enough */
1974                 rc = cifs_readpage_worker(file, page, &offset);
1975         } else {
1976                 /* we could try using another file handle if there is one -
1977                    but how would we lock it to prevent close of that handle
1978                    racing with this read? In any case
1979                    this will be written out by commit_write so is fine */
1980         }
1981
1982         /* we do not need to pass errors back
1983            e.g. if we do not have read access to the file
1984            because cifs_commit_write will do the right thing.  -- shaggy */
1985
1986         return 0;
1987 }
1988
1989 const struct address_space_operations cifs_addr_ops = {
1990         .readpage = cifs_readpage,
1991         .readpages = cifs_readpages,
1992         .writepage = cifs_writepage,
1993         .writepages = cifs_writepages,
1994         .prepare_write = cifs_prepare_write,
1995         .commit_write = cifs_commit_write,
1996         .set_page_dirty = __set_page_dirty_nobuffers,
1997         /* .sync_page = cifs_sync_page, */
1998         /* .direct_IO = */
1999 };
2000
2001 /*
2002  * cifs_readpages requires the server to support a buffer large enough to
2003  * contain the header plus one complete page of data.  Otherwise, we need
2004  * to leave cifs_readpages out of the address space operations.
2005  */
2006 const struct address_space_operations cifs_addr_ops_smallbuf = {
2007         .readpage = cifs_readpage,
2008         .writepage = cifs_writepage,
2009         .writepages = cifs_writepages,
2010         .prepare_write = cifs_prepare_write,
2011         .commit_write = cifs_commit_write,
2012         .set_page_dirty = __set_page_dirty_nobuffers,
2013         /* .sync_page = cifs_sync_page, */
2014         /* .direct_IO = */
2015 };