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., 2002,2003
   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/smp_lock.h>
  31 #include <linux/writeback.h>
  32 #include <linux/task_io_accounting_ops.h>
  33 #include <linux/delay.h>
  34 #include <asm/div64.h>
  35 #include "cifsfs.h"
  36 #include "cifspdu.h"
  37 #include "cifsglob.h"
  38 #include "cifsproto.h"
  39 #include "cifs_unicode.h"
  40 #include "cifs_debug.h"
  41 #include "cifs_fs_sb.h"
  42
  43 static inline struct cifsFileInfo *cifs_init_private(
  44         struct cifsFileInfo *private_data, struct inode *inode,
  45         struct file *file, __u16 netfid)
  46 {
  47         memset(private_data, 0, sizeof(struct cifsFileInfo));
  48         private_data->netfid = netfid;
  49         private_data->pid = current->tgid;
  50         init_MUTEX(&private_data->fh_sem);
  51         init_MUTEX(&private_data->lock_sem);
  52         INIT_LIST_HEAD(&private_data->llist);
  53         private_data->pfile = file; /* needed for writepage */
  54         private_data->pInode = inode;
  55         private_data->invalidHandle = FALSE;
  56         private_data->closePend = FALSE;
  57         /* we have to track num writers to the inode, since writepages
  58         does not tell us which handle the write is for so there can
  59         be a close (overlapping with write) of the filehandle that
  60         cifs_writepages chose to use */
  61         atomic_set(&private_data->wrtPending,0);
  62
  63         return private_data;
  64 }
  65
  66 static inline int cifs_convert_flags(unsigned int flags)
  67 {
  68         if ((flags & O_ACCMODE) == O_RDONLY)
  69                 return GENERIC_READ;
  70         else if ((flags & O_ACCMODE) == O_WRONLY)
  71                 return GENERIC_WRITE;
  72         else if ((flags & O_ACCMODE) == O_RDWR) {
  73                 /* GENERIC_ALL is too much permission to request
  74                    can cause unnecessary access denied on create */
  75                 /* return GENERIC_ALL; */
  76                 return (GENERIC_READ | GENERIC_WRITE);
  77         }
  78
  79         return 0x20197;
  80 }
  81
  82 static inline int cifs_get_disposition(unsigned int flags)
  83 {
  84         if ((flags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
  85                 return FILE_CREATE;
  86         else if ((flags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
  87                 return FILE_OVERWRITE_IF;
  88         else if ((flags & O_CREAT) == O_CREAT)
  89                 return FILE_OPEN_IF;
  90         else if ((flags & O_TRUNC) == O_TRUNC)
  91                 return FILE_OVERWRITE;
  92         else
  93                 return FILE_OPEN;
  94 }
  95
  96 /* all arguments to this function must be checked for validity in caller */
  97 static inline int cifs_open_inode_helper(struct inode *inode, struct file *file,
  98         struct cifsInodeInfo *pCifsInode, struct cifsFileInfo *pCifsFile,
  99         struct cifsTconInfo *pTcon, int *oplock, FILE_ALL_INFO *buf,
 100         char *full_path, int xid)
 101 {
 102         struct timespec temp;
 103         int rc;
 104
 105         /* want handles we can use to read with first
 106            in the list so we do not have to walk the
 107            list to search for one in prepare_write */
 108         if ((file->f_flags & O_ACCMODE) == O_WRONLY) {
 109                 list_add_tail(&pCifsFile->flist,
 110                               &pCifsInode->openFileList);
 111         } else {
 112                 list_add(&pCifsFile->flist,
 113                          &pCifsInode->openFileList);
 114         }
 115         write_unlock(&GlobalSMBSeslock);
 116         if (pCifsInode->clientCanCacheRead) {
 117                 /* we have the inode open somewhere else
 118                    no need to discard cache data */
 119                 goto client_can_cache;
 120         }
 121
 122         /* BB need same check in cifs_create too? */
 123         /* if not oplocked, invalidate inode pages if mtime or file
 124            size changed */
 125         temp = cifs_NTtimeToUnix(le64_to_cpu(buf->LastWriteTime));
 126         if (timespec_equal(&file->f_path.dentry->d_inode->i_mtime, &temp) &&
 127                            (file->f_path.dentry->d_inode->i_size ==
 128                             (loff_t)le64_to_cpu(buf->EndOfFile))) {
 129                 cFYI(1, ("inode unchanged on server"));
 130         } else {
 131                 if (file->f_path.dentry->d_inode->i_mapping) {
 132                 /* BB no need to lock inode until after invalidate
 133                    since namei code should already have it locked? */
 134                         filemap_write_and_wait(file->f_path.dentry->d_inode->i_mapping);
 135                 }
 136                 cFYI(1, ("invalidating remote inode since open detected it "
 137                          "changed"));
 138                 invalidate_remote_inode(file->f_path.dentry->d_inode);
 139         }
 140
 141 client_can_cache:
 142         if (pTcon->ses->capabilities & CAP_UNIX)
 143                 rc = cifs_get_inode_info_unix(&file->f_path.dentry->d_inode,
 144                         full_path, inode->i_sb, xid);
 145         else
 146                 rc = cifs_get_inode_info(&file->f_path.dentry->d_inode,
 147                         full_path, buf, inode->i_sb, xid);
 148
 149         if ((*oplock & 0xF) == OPLOCK_EXCLUSIVE) {
 150                 pCifsInode->clientCanCacheAll = TRUE;
 151                 pCifsInode->clientCanCacheRead = TRUE;
 152                 cFYI(1, ("Exclusive Oplock granted on inode %p",
 153                          file->f_path.dentry->d_inode));
 154         } else if ((*oplock & 0xF) == OPLOCK_READ)
 155                 pCifsInode->clientCanCacheRead = TRUE;
 156
 157         return rc;
 158 }
 159
 160 int cifs_open(struct inode *inode, struct file *file)
 161 {
 162         int rc = -EACCES;
 163         int xid, oplock;
 164         struct cifs_sb_info *cifs_sb;
 165         struct cifsTconInfo *pTcon;
 166         struct cifsFileInfo *pCifsFile;
 167         struct cifsInodeInfo *pCifsInode;
 168         struct list_head *tmp;
 169         char *full_path = NULL;
 170         int desiredAccess;
 171         int disposition;
 172         __u16 netfid;
 173         FILE_ALL_INFO *buf = NULL;
 174
 175         xid = GetXid();
 176
 177         cifs_sb = CIFS_SB(inode->i_sb);
 178         pTcon = cifs_sb->tcon;
 179
 180         if (file->f_flags & O_CREAT) {
 181                 /* search inode for this file and fill in file->private_data */
 182                 pCifsInode = CIFS_I(file->f_path.dentry->d_inode);
 183                 read_lock(&GlobalSMBSeslock);
 184                 list_for_each(tmp, &pCifsInode->openFileList) {
 185                         pCifsFile = list_entry(tmp, struct cifsFileInfo,
 186                                                flist);
 187                         if ((pCifsFile->pfile == NULL) &&
 188                             (pCifsFile->pid == current->tgid)) {
 189                                 /* mode set in cifs_create */
 190
 191                                 /* needed for writepage */
 192                                 pCifsFile->pfile = file;
 193
 194                                 file->private_data = pCifsFile;
 195                                 break;
 196                         }
 197                 }
 198                 read_unlock(&GlobalSMBSeslock);
 199                 if (file->private_data != NULL) {
 200                         rc = 0;
 201                         FreeXid(xid);
 202                         return rc;
 203                 } else {
 204                         if (file->f_flags & O_EXCL)
 205                                 cERROR(1, ("could not find file instance for "
 206                                            "new file %p", file));
 207                 }
 208         }
 209
 210         full_path = build_path_from_dentry(file->f_path.dentry);
 211         if (full_path == NULL) {
 212                 FreeXid(xid);
 213                 return -ENOMEM;
 214         }
 215
 216         cFYI(1, (" inode = 0x%p file flags are 0x%x for %s",
 217                  inode, file->f_flags, full_path));
 218         desiredAccess = cifs_convert_flags(file->f_flags);
 219
 220 /*********************************************************************
 221  *  open flag mapping table:
 222  *
 223  *      POSIX Flag            CIFS Disposition
 224  *      ----------            ----------------
 225  *      O_CREAT               FILE_OPEN_IF
 226  *      O_CREAT | O_EXCL      FILE_CREATE
 227  *      O_CREAT | O_TRUNC     FILE_OVERWRITE_IF
 228  *      O_TRUNC               FILE_OVERWRITE
 229  *      none of the above     FILE_OPEN
 230  *
 231  *      Note that there is not a direct match between disposition
 232  *      FILE_SUPERSEDE (ie create whether or not file exists although
 233  *      O_CREAT | O_TRUNC is similar but truncates the existing
 234  *      file rather than creating a new file as FILE_SUPERSEDE does
 235  *      (which uses the attributes / metadata passed in on open call)
 236  *?
 237  *?  O_SYNC is a reasonable match to CIFS writethrough flag
 238  *?  and the read write flags match reasonably.  O_LARGEFILE
 239  *?  is irrelevant because largefile support is always used
 240  *?  by this client. Flags O_APPEND, O_DIRECT, O_DIRECTORY,
 241  *       O_FASYNC, O_NOFOLLOW, O_NONBLOCK need further investigation
 242  *********************************************************************/
 243
 244         disposition = cifs_get_disposition(file->f_flags);
 245
 246         if (oplockEnabled)
 247                 oplock = REQ_OPLOCK;
 248         else
 249                 oplock = FALSE;
 250
 251         /* BB pass O_SYNC flag through on file attributes .. BB */
 252
 253         /* Also refresh inode by passing in file_info buf returned by SMBOpen
 254            and calling get_inode_info with returned buf (at least helps
 255            non-Unix server case) */
 256
 257         /* BB we can not do this if this is the second open of a file
 258            and the first handle has writebehind data, we might be
 259            able to simply do a filemap_fdatawrite/filemap_fdatawait first */
 260         buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
 261         if (!buf) {
 262                 rc = -ENOMEM;
 263                 goto out;
 264         }
 265
 266         if (cifs_sb->tcon->ses->capabilities & CAP_NT_SMBS)
 267                 rc = CIFSSMBOpen(xid, pTcon, full_path, disposition,
 268                          desiredAccess, CREATE_NOT_DIR, &netfid, &oplock, buf,
 269                          cifs_sb->local_nls, cifs_sb->mnt_cifs_flags
 270                                  & CIFS_MOUNT_MAP_SPECIAL_CHR);
 271         else
 272                 rc = -EIO; /* no NT SMB support fall into legacy open below */
 273
 274         if (rc == -EIO) {
 275                 /* Old server, try legacy style OpenX */
 276                 rc = SMBLegacyOpen(xid, pTcon, full_path, disposition,
 277                         desiredAccess, CREATE_NOT_DIR, &netfid, &oplock, buf,
 278                         cifs_sb->local_nls, cifs_sb->mnt_cifs_flags
 279                                 & CIFS_MOUNT_MAP_SPECIAL_CHR);
 280         }
 281         if (rc) {
 282                 cFYI(1, ("cifs_open returned 0x%x", rc));
 283                 goto out;
 284         }
 285         file->private_data =
 286                 kmalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
 287         if (file->private_data == NULL) {
 288                 rc = -ENOMEM;
 289                 goto out;
 290         }
 291         pCifsFile = cifs_init_private(file->private_data, inode, file, netfid);
 292         write_lock(&GlobalSMBSeslock);
 293         list_add(&pCifsFile->tlist, &pTcon->openFileList);
 294
 295         pCifsInode = CIFS_I(file->f_path.dentry->d_inode);
 296         if (pCifsInode) {
 297                 rc = cifs_open_inode_helper(inode, file, pCifsInode,
 298                                             pCifsFile, pTcon,
 299                                             &oplock, buf, full_path, xid);
 300         } else {
 301                 write_unlock(&GlobalSMBSeslock);
 302         }
 303
 304         if (oplock & CIFS_CREATE_ACTION) {
 305                 /* time to set mode which we can not set earlier due to
 306                    problems creating new read-only files */
 307                 if (cifs_sb->tcon->ses->capabilities & CAP_UNIX) {
 308                         CIFSSMBUnixSetPerms(xid, pTcon, full_path,
 309                                             inode->i_mode,
 310                                             (__u64)-1, (__u64)-1, 0 /* dev */,
 311                                             cifs_sb->local_nls,
 312                                             cifs_sb->mnt_cifs_flags &
 313                                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
 314                 } else {
 315                         /* BB implement via Windows security descriptors eg
 316                            CIFSSMBWinSetPerms(xid, pTcon, full_path, mode,
 317                                               -1, -1, local_nls);
 318                            in the meantime could set r/o dos attribute when
 319                            perms are eg: mode & 0222 == 0 */
 320                 }
 321         }
 322
 323 out:
 324         kfree(buf);
 325         kfree(full_path);
 326         FreeXid(xid);
 327         return rc;
 328 }
 329
 330 /* Try to reacquire byte range locks that were released when session */
 331 /* to server was lost */
 332 static int cifs_relock_file(struct cifsFileInfo *cifsFile)
 333 {
 334         int rc = 0;
 335
 336 /* BB list all locks open on this file and relock */
 337
 338         return rc;
 339 }
 340
 341 static int cifs_reopen_file(struct inode *inode, struct file *file,
 342         int can_flush)
 343 {
 344         int rc = -EACCES;
 345         int xid, oplock;
 346         struct cifs_sb_info *cifs_sb;
 347         struct cifsTconInfo *pTcon;
 348         struct cifsFileInfo *pCifsFile;
 349         struct cifsInodeInfo *pCifsInode;
 350         char *full_path = NULL;
 351         int desiredAccess;
 352         int disposition = FILE_OPEN;
 353         __u16 netfid;
 354
 355         if (inode == NULL)
 356                 return -EBADF;
 357         if (file->private_data) {
 358                 pCifsFile = (struct cifsFileInfo *)file->private_data;
 359         } else
 360                 return -EBADF;
 361
 362         xid = GetXid();
 363         down(&pCifsFile->fh_sem);
 364         if (pCifsFile->invalidHandle == FALSE) {
 365                 up(&pCifsFile->fh_sem);
 366                 FreeXid(xid);
 367                 return 0;
 368         }
 369
 370         if (file->f_path.dentry == NULL) {
 371                 up(&pCifsFile->fh_sem);
 372                 cFYI(1, ("failed file reopen, no valid name if dentry freed"));
 373                 FreeXid(xid);
 374                 return -EBADF;
 375         }
 376         cifs_sb = CIFS_SB(inode->i_sb);
 377         pTcon = cifs_sb->tcon;
 378 /* can not grab rename sem here because various ops, including
 379    those that already have the rename sem can end up causing writepage
 380    to get called and if the server was down that means we end up here,
 381    and we can never tell if the caller already has the rename_sem */
 382         full_path = build_path_from_dentry(file->f_path.dentry);
 383         if (full_path == NULL) {
 384                 up(&pCifsFile->fh_sem);
 385                 FreeXid(xid);
 386                 return -ENOMEM;
 387         }
 388
 389         cFYI(1, (" inode = 0x%p file flags are 0x%x for %s",
 390                  inode, file->f_flags,full_path));
 391         desiredAccess = cifs_convert_flags(file->f_flags);
 392
 393         if (oplockEnabled)
 394                 oplock = REQ_OPLOCK;
 395         else
 396                 oplock = FALSE;
 397
 398         /* Can not refresh inode by passing in file_info buf to be returned
 399            by SMBOpen and then calling get_inode_info with returned buf
 400            since file might have write behind data that needs to be flushed
 401            and server version of file size can be stale. If we knew for sure
 402            that inode was not dirty locally we could do this */
 403
 404 /*      buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
 405         if (buf == 0) {
 406                 up(&pCifsFile->fh_sem);
 407                 kfree(full_path);
 408                 FreeXid(xid);
 409                 return -ENOMEM;
 410         } */
 411         rc = CIFSSMBOpen(xid, pTcon, full_path, disposition, desiredAccess,
 412                          CREATE_NOT_DIR, &netfid, &oplock, NULL,
 413                          cifs_sb->local_nls, cifs_sb->mnt_cifs_flags &
 414                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
 415         if (rc) {
 416                 up(&pCifsFile->fh_sem);
 417                 cFYI(1, ("cifs_open returned 0x%x", rc));
 418                 cFYI(1, ("oplock: %d", oplock));
 419         } else {
 420                 pCifsFile->netfid = netfid;
 421                 pCifsFile->invalidHandle = FALSE;
 422                 up(&pCifsFile->fh_sem);
 423                 pCifsInode = CIFS_I(inode);
 424                 if (pCifsInode) {
 425                         if (can_flush) {
 426                                 filemap_write_and_wait(inode->i_mapping);
 427                         /* temporarily disable caching while we
 428                            go to server to get inode info */
 429                                 pCifsInode->clientCanCacheAll = FALSE;
 430                                 pCifsInode->clientCanCacheRead = FALSE;
 431                                 if (pTcon->ses->capabilities & CAP_UNIX)
 432                                         rc = cifs_get_inode_info_unix(&inode,
 433                                                 full_path, inode->i_sb, xid);
 434                                 else
 435                                         rc = cifs_get_inode_info(&inode,
 436                                                 full_path, NULL, inode->i_sb,
 437                                                 xid);
 438                         } /* else we are writing out data to server already
 439                              and could deadlock if we tried to flush data, and
 440                              since we do not know if we have data that would
 441                              invalidate the current end of file on the server
 442                              we can not go to the server to get the new inod
 443                              info */
 444                         if ((oplock & 0xF) == OPLOCK_EXCLUSIVE) {
 445                                 pCifsInode->clientCanCacheAll = TRUE;
 446                                 pCifsInode->clientCanCacheRead = TRUE;
 447                                 cFYI(1, ("Exclusive Oplock granted on inode %p",
 448                                          file->f_path.dentry->d_inode));
 449                         } else if ((oplock & 0xF) == OPLOCK_READ) {
 450                                 pCifsInode->clientCanCacheRead = TRUE;
 451                                 pCifsInode->clientCanCacheAll = FALSE;
 452                         } else {
 453                                 pCifsInode->clientCanCacheRead = FALSE;
 454                                 pCifsInode->clientCanCacheAll = FALSE;
 455                         }
 456                         cifs_relock_file(pCifsFile);
 457                 }
 458         }
 459
 460         kfree(full_path);
 461         FreeXid(xid);
 462         return rc;
 463 }
 464
 465 int cifs_close(struct inode *inode, struct file *file)
 466 {
 467         int rc = 0;
 468         int xid;
 469         struct cifs_sb_info *cifs_sb;
 470         struct cifsTconInfo *pTcon;
 471         struct cifsFileInfo *pSMBFile =
 472                 (struct cifsFileInfo *)file->private_data;
 473
 474         xid = GetXid();
 475
 476         cifs_sb = CIFS_SB(inode->i_sb);
 477         pTcon = cifs_sb->tcon;
 478         if (pSMBFile) {
 479                 struct cifsLockInfo *li, *tmp;
 480
 481                 pSMBFile->closePend = TRUE;
 482                 if (pTcon) {
 483                         /* no sense reconnecting to close a file that is
 484                            already closed */
 485                         if (pTcon->tidStatus != CifsNeedReconnect) {
 486                                 int timeout = 2;
 487                                 while((atomic_read(&pSMBFile->wrtPending) != 0)
 488                                          && (timeout < 1000) ) {
 489                                         /* Give write a better chance to get to
 490                                         server ahead of the close.  We do not
 491                                         want to add a wait_q here as it would
 492                                         increase the memory utilization as
 493                                         the struct would be in each open file,
 494                                         but this should give enough time to
 495                                         clear the socket */
 496 #ifdef CONFIG_CIFS_DEBUG2
 497                                         cFYI(1,("close delay, write pending"));
 498 #endif /* DEBUG2 */
 499                                         msleep(timeout);
 500                                         timeout *= 4;
 501                                 }
 502                                 if(atomic_read(&pSMBFile->wrtPending))
 503                                         cERROR(1,("close with pending writes"));
 504                                 rc = CIFSSMBClose(xid, pTcon,
 505                                                   pSMBFile->netfid);
 506                         }
 507                 }
 508
 509                 /* Delete any outstanding lock records.
 510                    We'll lose them when the file is closed anyway. */
 511                 down(&pSMBFile->lock_sem);
 512                 list_for_each_entry_safe(li, tmp, &pSMBFile->llist, llist) {
 513                         list_del(&li->llist);
 514                         kfree(li);
 515                 }
 516                 up(&pSMBFile->lock_sem);
 517
 518                 write_lock(&GlobalSMBSeslock);
 519                 list_del(&pSMBFile->flist);
 520                 list_del(&pSMBFile->tlist);
 521                 write_unlock(&GlobalSMBSeslock);
 522                 kfree(pSMBFile->search_resume_name);
 523                 kfree(file->private_data);
 524                 file->private_data = NULL;
 525         } else
 526                 rc = -EBADF;
 527
 528         if (list_empty(&(CIFS_I(inode)->openFileList))) {
 529                 cFYI(1, ("closing last open instance for inode %p", inode));
 530                 /* if the file is not open we do not know if we can cache info
 531                    on this inode, much less write behind and read ahead */
 532                 CIFS_I(inode)->clientCanCacheRead = FALSE;
 533                 CIFS_I(inode)->clientCanCacheAll  = FALSE;
 534         }
 535         if ((rc ==0) && CIFS_I(inode)->write_behind_rc)
 536                 rc = CIFS_I(inode)->write_behind_rc;
 537         FreeXid(xid);
 538         return rc;
 539 }
 540
 541 int cifs_closedir(struct inode *inode, struct file *file)
 542 {
 543         int rc = 0;
 544         int xid;
 545         struct cifsFileInfo *pCFileStruct =
 546             (struct cifsFileInfo *)file->private_data;
 547         char *ptmp;
 548
 549         cFYI(1, ("Closedir inode = 0x%p", inode));
 550
 551         xid = GetXid();
 552
 553         if (pCFileStruct) {
 554                 struct cifsTconInfo *pTcon;
 555                 struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
 556
 557                 pTcon = cifs_sb->tcon;
 558
 559                 cFYI(1, ("Freeing private data in close dir"));
 560                 if ((pCFileStruct->srch_inf.endOfSearch == FALSE) &&
 561                    (pCFileStruct->invalidHandle == FALSE)) {
 562                         pCFileStruct->invalidHandle = TRUE;
 563                         rc = CIFSFindClose(xid, pTcon, pCFileStruct->netfid);
 564                         cFYI(1, ("Closing uncompleted readdir with rc %d",
 565                                  rc));
 566                         /* not much we can do if it fails anyway, ignore rc */
 567                         rc = 0;
 568                 }
 569                 ptmp = pCFileStruct->srch_inf.ntwrk_buf_start;
 570                 if (ptmp) {
 571                         cFYI(1, ("closedir free smb buf in srch struct"));
 572                         pCFileStruct->srch_inf.ntwrk_buf_start = NULL;
 573                         if(pCFileStruct->srch_inf.smallBuf)
 574                                 cifs_small_buf_release(ptmp);
 575                         else
 576                                 cifs_buf_release(ptmp);
 577                 }
 578                 ptmp = pCFileStruct->search_resume_name;
 579                 if (ptmp) {
 580                         cFYI(1, ("closedir free resume name"));
 581                         pCFileStruct->search_resume_name = NULL;
 582                         kfree(ptmp);
 583                 }
 584                 kfree(file->private_data);
 585                 file->private_data = NULL;
 586         }
 587         /* BB can we lock the filestruct while this is going on? */
 588         FreeXid(xid);
 589         return rc;
 590 }
 591
 592 static int store_file_lock(struct cifsFileInfo *fid, __u64 len,
 593                                 __u64 offset, __u8 lockType)
 594 {
 595         struct cifsLockInfo *li = kmalloc(sizeof(struct cifsLockInfo), GFP_KERNEL);
 596         if (li == NULL)
 597                 return -ENOMEM;
 598         li->offset = offset;
 599         li->length = len;
 600         li->type = lockType;
 601         down(&fid->lock_sem);
 602         list_add(&li->llist, &fid->llist);
 603         up(&fid->lock_sem);
 604         return 0;
 605 }
 606
 607 int cifs_lock(struct file *file, int cmd, struct file_lock *pfLock)
 608 {
 609         int rc, xid;
 610         __u32 numLock = 0;
 611         __u32 numUnlock = 0;
 612         __u64 length;
 613         int wait_flag = FALSE;
 614         struct cifs_sb_info *cifs_sb;
 615         struct cifsTconInfo *pTcon;
 616         __u16 netfid;
 617         __u8 lockType = LOCKING_ANDX_LARGE_FILES;
 618         int posix_locking;
 619
 620         length = 1 + pfLock->fl_end - pfLock->fl_start;
 621         rc = -EACCES;
 622         xid = GetXid();
 623
 624         cFYI(1, ("Lock parm: 0x%x flockflags: "
 625                  "0x%x flocktype: 0x%x start: %lld end: %lld",
 626                 cmd, pfLock->fl_flags, pfLock->fl_type, pfLock->fl_start,
 627                 pfLock->fl_end));
 628
 629         if (pfLock->fl_flags & FL_POSIX)
 630                 cFYI(1, ("Posix"));
 631         if (pfLock->fl_flags & FL_FLOCK)
 632                 cFYI(1, ("Flock"));
 633         if (pfLock->fl_flags & FL_SLEEP) {
 634                 cFYI(1, ("Blocking lock"));
 635                 wait_flag = TRUE;
 636         }
 637         if (pfLock->fl_flags & FL_ACCESS)
 638                 cFYI(1, ("Process suspended by mandatory locking - "
 639                          "not implemented yet"));
 640         if (pfLock->fl_flags & FL_LEASE)
 641                 cFYI(1, ("Lease on file - not implemented yet"));
 642         if (pfLock->fl_flags &
 643             (~(FL_POSIX | FL_FLOCK | FL_SLEEP | FL_ACCESS | FL_LEASE)))
 644                 cFYI(1, ("Unknown lock flags 0x%x", pfLock->fl_flags));
 645
 646         if (pfLock->fl_type == F_WRLCK) {
 647                 cFYI(1, ("F_WRLCK "));
 648                 numLock = 1;
 649         } else if (pfLock->fl_type == F_UNLCK) {
 650                 cFYI(1, ("F_UNLCK"));
 651                 numUnlock = 1;
 652                 /* Check if unlock includes more than
 653                 one lock range */
 654         } else if (pfLock->fl_type == F_RDLCK) {
 655                 cFYI(1, ("F_RDLCK"));
 656                 lockType |= LOCKING_ANDX_SHARED_LOCK;
 657                 numLock = 1;
 658         } else if (pfLock->fl_type == F_EXLCK) {
 659                 cFYI(1, ("F_EXLCK"));
 660                 numLock = 1;
 661         } else if (pfLock->fl_type == F_SHLCK) {
 662                 cFYI(1, ("F_SHLCK"));
 663                 lockType |= LOCKING_ANDX_SHARED_LOCK;
 664                 numLock = 1;
 665         } else
 666                 cFYI(1, ("Unknown type of lock"));
 667
 668         cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
 669         pTcon = cifs_sb->tcon;
 670
 671         if (file->private_data == NULL) {
 672                 FreeXid(xid);
 673                 return -EBADF;
 674         }
 675         netfid = ((struct cifsFileInfo *)file->private_data)->netfid;
 676
 677         posix_locking = (cifs_sb->tcon->ses->capabilities & CAP_UNIX) &&
 678                         (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(cifs_sb->tcon->fsUnixInfo.Capability));
 679
 680         /* BB add code here to normalize offset and length to
 681         account for negative length which we can not accept over the
 682         wire */
 683         if (IS_GETLK(cmd)) {
 684                 if(posix_locking) {
 685                         int posix_lock_type;
 686                         if(lockType & LOCKING_ANDX_SHARED_LOCK)
 687                                 posix_lock_type = CIFS_RDLCK;
 688                         else
 689                                 posix_lock_type = CIFS_WRLCK;
 690                         rc = CIFSSMBPosixLock(xid, pTcon, netfid, 1 /* get */,
 691                                         length, pfLock,
 692                                         posix_lock_type, wait_flag);
 693                         FreeXid(xid);
 694                         return rc;
 695                 }
 696
 697                 /* BB we could chain these into one lock request BB */
 698                 rc = CIFSSMBLock(xid, pTcon, netfid, length, pfLock->fl_start,
 699                                  0, 1, lockType, 0 /* wait flag */ );
 700                 if (rc == 0) {
 701                         rc = CIFSSMBLock(xid, pTcon, netfid, length,
 702                                          pfLock->fl_start, 1 /* numUnlock */ ,
 703                                          0 /* numLock */ , lockType,
 704                                          0 /* wait flag */ );
 705                         pfLock->fl_type = F_UNLCK;
 706                         if (rc != 0)
 707                                 cERROR(1, ("Error unlocking previously locked "
 708                                            "range %d during test of lock", rc));
 709                         rc = 0;
 710
 711                 } else {
 712                         /* if rc == ERR_SHARING_VIOLATION ? */
 713                         rc = 0; /* do not change lock type to unlock
 714                                    since range in use */
 715                 }
 716
 717                 FreeXid(xid);
 718                 return rc;
 719         }
 720
 721         if (!numLock && !numUnlock) {
 722                 /* if no lock or unlock then nothing
 723                 to do since we do not know what it is */
 724                 FreeXid(xid);
 725                 return -EOPNOTSUPP;
 726         }
 727
 728         if (posix_locking) {
 729                 int posix_lock_type;
 730                 if(lockType & LOCKING_ANDX_SHARED_LOCK)
 731                         posix_lock_type = CIFS_RDLCK;
 732                 else
 733                         posix_lock_type = CIFS_WRLCK;
 734
 735                 if(numUnlock == 1)
 736                         posix_lock_type = CIFS_UNLCK;
 737
 738                 rc = CIFSSMBPosixLock(xid, pTcon, netfid, 0 /* set */,
 739                                       length, pfLock,
 740                                       posix_lock_type, wait_flag);
 741         } else {
 742                 struct cifsFileInfo *fid = (struct cifsFileInfo *)file->private_data;
 743
 744                 if (numLock) {
 745                         rc = CIFSSMBLock(xid, pTcon, netfid, length, pfLock->fl_start,
 746                                         0, numLock, lockType, wait_flag);
 747
 748                         if (rc == 0) {
 749                                 /* For Windows locks we must store them. */
 750                                 rc = store_file_lock(fid, length,
 751                                                 pfLock->fl_start, lockType);
 752                         }
 753                 } else if (numUnlock) {
 754                         /* For each stored lock that this unlock overlaps
 755                            completely, unlock it. */
 756                         int stored_rc = 0;
 757                         struct cifsLockInfo *li, *tmp;
 758
 759                         rc = 0;
 760                         down(&fid->lock_sem);
 761                         list_for_each_entry_safe(li, tmp, &fid->llist, llist) {
 762                                 if (pfLock->fl_start <= li->offset &&
 763                                                 length >= li->length) {
 764                                         stored_rc = CIFSSMBLock(xid, pTcon, netfid,
 765                                                         li->length, li->offset,
 766                                                         1, 0, li->type, FALSE);
 767                                         if (stored_rc)
 768                                                 rc = stored_rc;
 769
 770                                         list_del(&li->llist);
 771                                         kfree(li);
 772                                 }
 773                         }
 774                         up(&fid->lock_sem);
 775                 }
 776         }
 777
 778         if (pfLock->fl_flags & FL_POSIX)
 779                 posix_lock_file_wait(file, pfLock);
 780         FreeXid(xid);
 781         return rc;
 782 }
 783
 784 ssize_t cifs_user_write(struct file *file, const char __user *write_data,
 785         size_t write_size, loff_t *poffset)
 786 {
 787         int rc = 0;
 788         unsigned int bytes_written = 0;
 789         unsigned int total_written;
 790         struct cifs_sb_info *cifs_sb;
 791         struct cifsTconInfo *pTcon;
 792         int xid, long_op;
 793         struct cifsFileInfo *open_file;
 794
 795         if (file->f_path.dentry == NULL)
 796                 return -EBADF;
 797
 798         cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
 799         if (cifs_sb == NULL)
 800                 return -EBADF;
 801
 802         pTcon = cifs_sb->tcon;
 803
 804         /* cFYI(1,
 805            (" write %d bytes to offset %lld of %s", write_size,
 806            *poffset, file->f_path.dentry->d_name.name)); */
 807
 808         if (file->private_data == NULL)
 809                 return -EBADF;
 810         else
 811                 open_file = (struct cifsFileInfo *) file->private_data;
 812
 813         xid = GetXid();
 814         if (file->f_path.dentry->d_inode == NULL) {
 815                 FreeXid(xid);
 816                 return -EBADF;
 817         }
 818
 819         if (*poffset > file->f_path.dentry->d_inode->i_size)
 820                 long_op = 2; /* writes past end of file can take a long time */
 821         else
 822                 long_op = 1;
 823
 824         for (total_written = 0; write_size > total_written;
 825              total_written += bytes_written) {
 826                 rc = -EAGAIN;
 827                 while (rc == -EAGAIN) {
 828                         if (file->private_data == NULL) {
 829                                 /* file has been closed on us */
 830                                 FreeXid(xid);
 831                         /* if we have gotten here we have written some data
 832                            and blocked, and the file has been freed on us while
 833                            we blocked so return what we managed to write */
 834                                 return total_written;
 835                         }
 836                         if (open_file->closePend) {
 837                                 FreeXid(xid);
 838                                 if (total_written)
 839                                         return total_written;
 840                                 else
 841                                         return -EBADF;
 842                         }
 843                         if (open_file->invalidHandle) {
 844                                 if ((file->f_path.dentry == NULL) ||
 845                                     (file->f_path.dentry->d_inode == NULL)) {
 846                                         FreeXid(xid);
 847                                         return total_written;
 848                                 }
 849                                 /* we could deadlock if we called
 850                                    filemap_fdatawait from here so tell
 851                                    reopen_file not to flush data to server
 852                                    now */
 853                                 rc = cifs_reopen_file(file->f_path.dentry->d_inode,
 854                                         file, FALSE);
 855                                 if (rc != 0)
 856                                         break;
 857                         }
 858
 859                         rc = CIFSSMBWrite(xid, pTcon,
 860                                 open_file->netfid,
 861                                 min_t(const int, cifs_sb->wsize,
 862                                       write_size - total_written),
 863                                 *poffset, &bytes_written,
 864                                 NULL, write_data + total_written, long_op);
 865                 }
 866                 if (rc || (bytes_written == 0)) {
 867                         if (total_written)
 868                                 break;
 869                         else {
 870                                 FreeXid(xid);
 871                                 return rc;
 872                         }
 873                 } else
 874                         *poffset += bytes_written;
 875                 long_op = FALSE; /* subsequent writes fast -
 876                                     15 seconds is plenty */
 877         }
 878
 879         cifs_stats_bytes_written(pTcon, total_written);
 880
 881         /* since the write may have blocked check these pointers again */
 882         if (file->f_path.dentry) {
 883                 if (file->f_path.dentry->d_inode) {
 884                         struct inode *inode = file->f_path.dentry->d_inode;
 885                         inode->i_ctime = inode->i_mtime =
 886                                 current_fs_time(inode->i_sb);
 887                         if (total_written > 0) {
 888                                 if (*poffset > file->f_path.dentry->d_inode->i_size)
 889                                         i_size_write(file->f_path.dentry->d_inode,
 890                                         *poffset);
 891                         }
 892                         mark_inode_dirty_sync(file->f_path.dentry->d_inode);
 893                 }
 894         }
 895         FreeXid(xid);
 896         return total_written;
 897 }
 898
 899 static ssize_t cifs_write(struct file *file, const char *write_data,
 900         size_t write_size, loff_t *poffset)
 901 {
 902         int rc = 0;
 903         unsigned int bytes_written = 0;
 904         unsigned int total_written;
 905         struct cifs_sb_info *cifs_sb;
 906         struct cifsTconInfo *pTcon;
 907         int xid, long_op;
 908         struct cifsFileInfo *open_file;
 909
 910         if (file->f_path.dentry == NULL)
 911                 return -EBADF;
 912
 913         cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
 914         if (cifs_sb == NULL)
 915                 return -EBADF;
 916
 917         pTcon = cifs_sb->tcon;
 918
 919         cFYI(1,("write %zd bytes to offset %lld of %s", write_size,
 920            *poffset, file->f_path.dentry->d_name.name));
 921
 922         if (file->private_data == NULL)
 923                 return -EBADF;
 924         else
 925                 open_file = (struct cifsFileInfo *)file->private_data;
 926
 927         xid = GetXid();
 928         if (file->f_path.dentry->d_inode == NULL) {
 929                 FreeXid(xid);
 930                 return -EBADF;
 931         }
 932
 933         if (*poffset > file->f_path.dentry->d_inode->i_size)
 934                 long_op = 2; /* writes past end of file can take a long time */
 935         else
 936                 long_op = 1;
 937
 938         for (total_written = 0; write_size > total_written;
 939              total_written += bytes_written) {
 940                 rc = -EAGAIN;
 941                 while (rc == -EAGAIN) {
 942                         if (file->private_data == NULL) {
 943                                 /* file has been closed on us */
 944                                 FreeXid(xid);
 945                         /* if we have gotten here we have written some data
 946                            and blocked, and the file has been freed on us
 947                            while we blocked so return what we managed to
 948                            write */
 949                                 return total_written;
 950                         }
 951                         if (open_file->closePend) {
 952                                 FreeXid(xid);
 953                                 if (total_written)
 954                                         return total_written;
 955                                 else
 956                                         return -EBADF;
 957                         }
 958                         if (open_file->invalidHandle) {
 959                                 if ((file->f_path.dentry == NULL) ||
 960                                    (file->f_path.dentry->d_inode == NULL)) {
 961                                         FreeXid(xid);
 962                                         return total_written;
 963                                 }
 964                                 /* we could deadlock if we called
 965                                    filemap_fdatawait from here so tell
 966                                    reopen_file not to flush data to
 967                                    server now */
 968                                 rc = cifs_reopen_file(file->f_path.dentry->d_inode,
 969                                         file, FALSE);
 970                                 if (rc != 0)
 971                                         break;
 972                         }
 973                         if(experimEnabled || (pTcon->ses->server &&
 974                                 ((pTcon->ses->server->secMode &
 975                                 (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED))
 976                                 == 0))) {
 977                                 struct kvec iov[2];
 978                                 unsigned int len;
 979
 980                                 len = min((size_t)cifs_sb->wsize,
 981                                           write_size - total_written);
 982                                 /* iov[0] is reserved for smb header */
 983                                 iov[1].iov_base = (char *)write_data +
 984                                                   total_written;
 985                                 iov[1].iov_len = len;
 986                                 rc = CIFSSMBWrite2(xid, pTcon,
 987                                                 open_file->netfid, len,
 988                                                 *poffset, &bytes_written,
 989                                                 iov, 1, long_op);
 990                         } else
 991                                 rc = CIFSSMBWrite(xid, pTcon,
 992                                          open_file->netfid,
 993                                          min_t(const int, cifs_sb->wsize,
 994                                                write_size - total_written),
 995                                          *poffset, &bytes_written,
 996                                          write_data + total_written,
 997                                          NULL, long_op);
 998                 }
 999                 if (rc || (bytes_written == 0)) {
1000                         if (total_written)
1001                                 break;
1002                         else {
1003                                 FreeXid(xid);
1004                                 return rc;
1005                         }
1006                 } else
1007                         *poffset += bytes_written;
1008                 long_op = FALSE; /* subsequent writes fast -
1009                                     15 seconds is plenty */
1010         }
1011
1012         cifs_stats_bytes_written(pTcon, total_written);
1013
1014         /* since the write may have blocked check these pointers again */
1015         if (file->f_path.dentry) {
1016                 if (file->f_path.dentry->d_inode) {
1017 /*BB We could make this contingent on superblock ATIME flag too */
1018 /*                      file->f_path.dentry->d_inode->i_ctime =
1019                         file->f_path.dentry->d_inode->i_mtime = CURRENT_TIME;*/
1020                         if (total_written > 0) {
1021                                 if (*poffset > file->f_path.dentry->d_inode->i_size)
1022                                         i_size_write(file->f_path.dentry->d_inode,
1023                                                      *poffset);
1024                         }
1025                         mark_inode_dirty_sync(file->f_path.dentry->d_inode);
1026                 }
1027         }
1028         FreeXid(xid);
1029         return total_written;
1030 }
1031
1032 struct cifsFileInfo *find_writable_file(struct cifsInodeInfo *cifs_inode)
1033 {
1034         struct cifsFileInfo *open_file;
1035         int rc;
1036
1037         /* Having a null inode here (because mapping->host was set to zero by
1038         the VFS or MM) should not happen but we had reports of on oops (due to
1039         it being zero) during stress testcases so we need to check for it */
1040
1041         if(cifs_inode == NULL) {
1042                 cERROR(1,("Null inode passed to cifs_writeable_file"));
1043                 dump_stack();
1044                 return NULL;
1045         }
1046
1047         read_lock(&GlobalSMBSeslock);
1048         list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
1049                 if (open_file->closePend)
1050                         continue;
1051                 if (open_file->pfile &&
1052                     ((open_file->pfile->f_flags & O_RDWR) ||
1053                      (open_file->pfile->f_flags & O_WRONLY))) {
1054                         atomic_inc(&open_file->wrtPending);
1055                         read_unlock(&GlobalSMBSeslock);
1056                         if((open_file->invalidHandle) &&
1057                            (!open_file->closePend) /* BB fixme -since the second clause can not be true remove it BB */) {
1058                                 rc = cifs_reopen_file(&cifs_inode->vfs_inode,
1059                                                       open_file->pfile, FALSE);
1060                                 /* if it fails, try another handle - might be */
1061                                 /* dangerous to hold up writepages with retry */
1062                                 if(rc) {
1063                                         cFYI(1,("failed on reopen file in wp"));
1064                                         read_lock(&GlobalSMBSeslock);
1065                                         /* can not use this handle, no write
1066                                         pending on this one after all */
1067                                         atomic_dec
1068                                              (&open_file->wrtPending);
1069                                         continue;
1070                                 }
1071                         }
1072                         return open_file;
1073                 }
1074         }
1075         read_unlock(&GlobalSMBSeslock);
1076         return NULL;
1077 }
1078
1079 static int cifs_partialpagewrite(struct page *page, unsigned from, unsigned to)
1080 {
1081         struct address_space *mapping = page->mapping;
1082         loff_t offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
1083         char *write_data;
1084         int rc = -EFAULT;
1085         int bytes_written = 0;
1086         struct cifs_sb_info *cifs_sb;
1087         struct cifsTconInfo *pTcon;
1088         struct inode *inode;
1089         struct cifsFileInfo *open_file;
1090
1091         if (!mapping || !mapping->host)
1092                 return -EFAULT;
1093
1094         inode = page->mapping->host;
1095         cifs_sb = CIFS_SB(inode->i_sb);
1096         pTcon = cifs_sb->tcon;
1097
1098         offset += (loff_t)from;
1099         write_data = kmap(page);
1100         write_data += from;
1101
1102         if ((to > PAGE_CACHE_SIZE) || (from > to)) {
1103                 kunmap(page);
1104                 return -EIO;
1105         }
1106
1107         /* racing with truncate? */
1108         if (offset > mapping->host->i_size) {
1109                 kunmap(page);
1110                 return 0; /* don't care */
1111         }
1112
1113         /* check to make sure that we are not extending the file */
1114         if (mapping->host->i_size - offset < (loff_t)to)
1115                 to = (unsigned)(mapping->host->i_size - offset);
1116
1117         open_file = find_writable_file(CIFS_I(mapping->host));
1118         if (open_file) {
1119                 bytes_written = cifs_write(open_file->pfile, write_data,
1120                                            to-from, &offset);
1121                 atomic_dec(&open_file->wrtPending);
1122                 /* Does mm or vfs already set times? */
1123                 inode->i_atime = inode->i_mtime = current_fs_time(inode->i_sb);
1124                 if ((bytes_written > 0) && (offset)) {
1125                         rc = 0;
1126                 } else if (bytes_written < 0) {
1127                         if (rc != -EBADF)
1128                                 rc = bytes_written;
1129                 }
1130         } else {
1131                 cFYI(1, ("No writeable filehandles for inode"));
1132                 rc = -EIO;
1133         }
1134
1135         kunmap(page);
1136         return rc;
1137 }
1138
1139 static int cifs_writepages(struct address_space *mapping,
1140                            struct writeback_control *wbc)
1141 {
1142         struct backing_dev_info *bdi = mapping->backing_dev_info;
1143         unsigned int bytes_to_write;
1144         unsigned int bytes_written;
1145         struct cifs_sb_info *cifs_sb;
1146         int done = 0;
1147         pgoff_t end;
1148         pgoff_t index;
1149         int range_whole = 0;
1150         struct kvec * iov;
1151         int len;
1152         int n_iov = 0;
1153         pgoff_t next;
1154         int nr_pages;
1155         __u64 offset = 0;
1156         struct cifsFileInfo *open_file;
1157         struct page *page;
1158         struct pagevec pvec;
1159         int rc = 0;
1160         int scanned = 0;
1161         int xid;
1162
1163         cifs_sb = CIFS_SB(mapping->host->i_sb);
1164
1165         /*
1166          * If wsize is smaller that the page cache size, default to writing
1167          * one page at a time via cifs_writepage
1168          */
1169         if (cifs_sb->wsize < PAGE_CACHE_SIZE)
1170                 return generic_writepages(mapping, wbc);
1171
1172         if((cifs_sb->tcon->ses) && (cifs_sb->tcon->ses->server))
1173                 if(cifs_sb->tcon->ses->server->secMode &
1174                           (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED))
1175                         if(!experimEnabled)
1176                                 return generic_writepages(mapping, wbc);
1177
1178         iov = kmalloc(32 * sizeof(struct kvec), GFP_KERNEL);
1179         if(iov == NULL)
1180                 return generic_writepages(mapping, wbc);
1181
1182
1183         /*
1184          * BB: Is this meaningful for a non-block-device file system?
1185          * If it is, we should test it again after we do I/O
1186          */
1187         if (wbc->nonblocking && bdi_write_congested(bdi)) {
1188                 wbc->encountered_congestion = 1;
1189                 kfree(iov);
1190                 return 0;
1191         }
1192
1193         xid = GetXid();
1194
1195         pagevec_init(&pvec, 0);
1196         if (wbc->range_cyclic) {
1197                 index = mapping->writeback_index; /* Start from prev offset */
1198                 end = -1;
1199         } else {
1200                 index = wbc->range_start >> PAGE_CACHE_SHIFT;
1201                 end = wbc->range_end >> PAGE_CACHE_SHIFT;
1202                 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
1203                         range_whole = 1;
1204                 scanned = 1;
1205         }
1206 retry:
1207         while (!done && (index <= end) &&
1208                (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
1209                         PAGECACHE_TAG_DIRTY,
1210                         min(end - index, (pgoff_t)PAGEVEC_SIZE - 1) + 1))) {
1211                 int first;
1212                 unsigned int i;
1213
1214                 first = -1;
1215                 next = 0;
1216                 n_iov = 0;
1217                 bytes_to_write = 0;
1218
1219                 for (i = 0; i < nr_pages; i++) {
1220                         page = pvec.pages[i];
1221                         /*
1222                          * At this point we hold neither mapping->tree_lock nor
1223                          * lock on the page itself: the page may be truncated or
1224                          * invalidated (changing page->mapping to NULL), or even
1225                          * swizzled back from swapper_space to tmpfs file
1226                          * mapping
1227                          */
1228
1229                         if (first < 0)
1230                                 lock_page(page);
1231                         else if (TestSetPageLocked(page))
1232                                 break;
1233
1234                         if (unlikely(page->mapping != mapping)) {
1235                                 unlock_page(page);
1236                                 break;
1237                         }
1238
1239                         if (!wbc->range_cyclic && page->index > end) {
1240                                 done = 1;
1241                                 unlock_page(page);
1242                                 break;
1243                         }
1244
1245                         if (next && (page->index != next)) {
1246                                 /* Not next consecutive page */
1247                                 unlock_page(page);
1248                                 break;
1249                         }
1250
1251                         if (wbc->sync_mode != WB_SYNC_NONE)
1252                                 wait_on_page_writeback(page);
1253
1254                         if (PageWriteback(page) ||
1255                                         !clear_page_dirty_for_io(page)) {
1256                                 unlock_page(page);
1257                                 break;
1258                         }
1259
1260                         /*
1261                          * This actually clears the dirty bit in the radix tree.
1262                          * See cifs_writepage() for more commentary.
1263                          */
1264                         set_page_writeback(page);
1265
1266                         if (page_offset(page) >= mapping->host->i_size) {
1267                                 done = 1;
1268                                 unlock_page(page);
1269                                 end_page_writeback(page);
1270                                 break;
1271                         }
1272
1273                         /*
1274                          * BB can we get rid of this?  pages are held by pvec
1275                          */
1276                         page_cache_get(page);
1277
1278                         len = min(mapping->host->i_size - page_offset(page),
1279                                   (loff_t)PAGE_CACHE_SIZE);
1280
1281                         /* reserve iov[0] for the smb header */
1282                         n_iov++;
1283                         iov[n_iov].iov_base = kmap(page);
1284                         iov[n_iov].iov_len = len;
1285                         bytes_to_write += len;
1286
1287                         if (first < 0) {
1288                                 first = i;
1289                                 offset = page_offset(page);
1290                         }
1291                         next = page->index + 1;
1292                         if (bytes_to_write + PAGE_CACHE_SIZE > cifs_sb->wsize)
1293                                 break;
1294                 }
1295                 if (n_iov) {
1296                         /* Search for a writable handle every time we call
1297                          * CIFSSMBWrite2.  We can't rely on the last handle
1298                          * we used to still be valid
1299                          */
1300                         open_file = find_writable_file(CIFS_I(mapping->host));
1301                         if (!open_file) {
1302                                 cERROR(1, ("No writable handles for inode"));
1303                                 rc = -EBADF;
1304                         } else {
1305                                 rc = CIFSSMBWrite2(xid, cifs_sb->tcon,
1306                                                    open_file->netfid,
1307                                                    bytes_to_write, offset,
1308                                                    &bytes_written, iov, n_iov,
1309                                                    1);
1310                                 atomic_dec(&open_file->wrtPending);
1311                                 if (rc || bytes_written < bytes_to_write) {
1312                                         cERROR(1,("Write2 ret %d, written = %d",
1313                                                   rc, bytes_written));
1314                                         /* BB what if continued retry is
1315                                            requested via mount flags? */
1316                                         set_bit(AS_EIO, &mapping->flags);
1317                                 } else {
1318                                         cifs_stats_bytes_written(cifs_sb->tcon,
1319                                                                  bytes_written);
1320                                 }
1321                         }
1322                         for (i = 0; i < n_iov; i++) {
1323                                 page = pvec.pages[first + i];
1324                                 /* Should we also set page error on
1325                                 success rc but too little data written? */
1326                                 /* BB investigate retry logic on temporary
1327                                 server crash cases and how recovery works
1328                                 when page marked as error */
1329                                 if(rc)
1330                                         SetPageError(page);
1331                                 kunmap(page);
1332                                 unlock_page(page);
1333                                 end_page_writeback(page);
1334                                 page_cache_release(page);
1335                         }
1336                         if ((wbc->nr_to_write -= n_iov) <= 0)
1337                                 done = 1;
1338                         index = next;
1339                 }
1340                 pagevec_release(&pvec);
1341         }
1342         if (!scanned && !done) {
1343                 /*
1344                  * We hit the last page and there is more work to be done: wrap
1345                  * back to the start of the file
1346                  */
1347                 scanned = 1;
1348                 index = 0;
1349                 goto retry;
1350         }
1351         if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
1352                 mapping->writeback_index = index;
1353
1354         FreeXid(xid);
1355         kfree(iov);
1356         return rc;
1357 }
1358
1359 static int cifs_writepage(struct page* page, struct writeback_control *wbc)
1360 {
1361         int rc = -EFAULT;
1362         int xid;
1363
1364         xid = GetXid();
1365 /* BB add check for wbc flags */
1366         page_cache_get(page);
1367         if (!PageUptodate(page)) {
1368                 cFYI(1, ("ppw - page not up to date"));
1369         }
1370
1371         /*
1372          * Set the "writeback" flag, and clear "dirty" in the radix tree.
1373          *
1374          * A writepage() implementation always needs to do either this,
1375          * or re-dirty the page with "redirty_page_for_writepage()" in
1376          * the case of a failure.
1377          *
1378          * Just unlocking the page will cause the radix tree tag-bits
1379          * to fail to update with the state of the page correctly.
1380          */
1381         set_page_writeback(page);
1382         rc = cifs_partialpagewrite(page, 0, PAGE_CACHE_SIZE);
1383         SetPageUptodate(page); /* BB add check for error and Clearuptodate? */
1384         unlock_page(page);
1385         end_page_writeback(page);
1386         page_cache_release(page);
1387         FreeXid(xid);
1388         return rc;
1389 }
1390
1391 static int cifs_commit_write(struct file *file, struct page *page,
1392         unsigned offset, unsigned to)
1393 {
1394         int xid;
1395         int rc = 0;
1396         struct inode *inode = page->mapping->host;
1397         loff_t position = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
1398         char *page_data;
1399
1400         xid = GetXid();
1401         cFYI(1, ("commit write for page %p up to position %lld for %d",
1402                  page, position, to));
1403         if (position > inode->i_size) {
1404                 i_size_write(inode, position);
1405                 /* if (file->private_data == NULL) {
1406                         rc = -EBADF;
1407                 } else {
1408                         open_file = (struct cifsFileInfo *)file->private_data;
1409                         cifs_sb = CIFS_SB(inode->i_sb);
1410                         rc = -EAGAIN;
1411                         while (rc == -EAGAIN) {
1412                                 if ((open_file->invalidHandle) &&
1413                                     (!open_file->closePend)) {
1414                                         rc = cifs_reopen_file(
1415                                                 file->f_path.dentry->d_inode, file);
1416                                         if (rc != 0)
1417                                                 break;
1418                                 }
1419                                 if (!open_file->closePend) {
1420                                         rc = CIFSSMBSetFileSize(xid,
1421                                                 cifs_sb->tcon, position,
1422                                                 open_file->netfid,
1423                                                 open_file->pid, FALSE);
1424                                 } else {
1425                                         rc = -EBADF;
1426                                         break;
1427                                 }
1428                         }
1429                         cFYI(1, (" SetEOF (commit write) rc = %d", rc));
1430                 } */
1431         }
1432         if (!PageUptodate(page)) {
1433                 position =  ((loff_t)page->index << PAGE_CACHE_SHIFT) + offset;
1434                 /* can not rely on (or let) writepage write this data */
1435                 if (to < offset) {
1436                         cFYI(1, ("Illegal offsets, can not copy from %d to %d",
1437                                 offset, to));
1438                         FreeXid(xid);
1439                         return rc;
1440                 }
1441                 /* this is probably better than directly calling
1442                    partialpage_write since in this function the file handle is
1443                    known which we might as well leverage */
1444                 /* BB check if anything else missing out of ppw
1445                    such as updating last write time */
1446                 page_data = kmap(page);
1447                 rc = cifs_write(file, page_data + offset, to-offset,
1448                                 &position);
1449                 if (rc > 0)
1450                         rc = 0;
1451                 /* else if (rc < 0) should we set writebehind rc? */
1452                 kunmap(page);
1453         } else {
1454                 set_page_dirty(page);
1455         }
1456
1457         FreeXid(xid);
1458         return rc;
1459 }
1460
1461 int cifs_fsync(struct file *file, struct dentry *dentry, int datasync)
1462 {
1463         int xid;
1464         int rc = 0;
1465         struct inode *inode = file->f_path.dentry->d_inode;
1466
1467         xid = GetXid();
1468
1469         cFYI(1, ("Sync file - name: %s datasync: 0x%x",
1470                 dentry->d_name.name, datasync));
1471
1472         rc = filemap_fdatawrite(inode->i_mapping);
1473         if (rc == 0)
1474                 CIFS_I(inode)->write_behind_rc = 0;
1475         FreeXid(xid);
1476         return rc;
1477 }
1478
1479 /* static void cifs_sync_page(struct page *page)
1480 {
1481         struct address_space *mapping;
1482         struct inode *inode;
1483         unsigned long index = page->index;
1484         unsigned int rpages = 0;
1485         int rc = 0;
1486
1487         cFYI(1, ("sync page %p",page));
1488         mapping = page->mapping;
1489         if (!mapping)
1490                 return 0;
1491         inode = mapping->host;
1492         if (!inode)
1493                 return; */
1494
1495 /*      fill in rpages then
1496         result = cifs_pagein_inode(inode, index, rpages); */ /* BB finish */
1497
1498 /*      cFYI(1, ("rpages is %d for sync page of Index %ld", rpages, index));
1499
1500 #if 0
1501         if (rc < 0)
1502                 return rc;
1503         return 0;
1504 #endif
1505 } */
1506
1507 /*
1508  * As file closes, flush all cached write data for this inode checking
1509  * for write behind errors.
1510  */
1511 int cifs_flush(struct file *file, fl_owner_t id)
1512 {
1513         struct inode * inode = file->f_path.dentry->d_inode;
1514         int rc = 0;
1515
1516         /* Rather than do the steps manually:
1517            lock the inode for writing
1518            loop through pages looking for write behind data (dirty pages)
1519            coalesce into contiguous 16K (or smaller) chunks to write to server
1520            send to server (prefer in parallel)
1521            deal with writebehind errors
1522            unlock inode for writing
1523            filemapfdatawrite appears easier for the time being */
1524
1525         rc = filemap_fdatawrite(inode->i_mapping);
1526         if (!rc) /* reset wb rc if we were able to write out dirty pages */
1527                 CIFS_I(inode)->write_behind_rc = 0;
1528
1529         cFYI(1, ("Flush inode %p file %p rc %d",inode,file,rc));
1530
1531         return rc;
1532 }
1533
1534 ssize_t cifs_user_read(struct file *file, char __user *read_data,
1535         size_t read_size, loff_t *poffset)
1536 {
1537         int rc = -EACCES;
1538         unsigned int bytes_read = 0;
1539         unsigned int total_read = 0;
1540         unsigned int current_read_size;
1541         struct cifs_sb_info *cifs_sb;
1542         struct cifsTconInfo *pTcon;
1543         int xid;
1544         struct cifsFileInfo *open_file;
1545         char *smb_read_data;
1546         char __user *current_offset;
1547         struct smb_com_read_rsp *pSMBr;
1548
1549         xid = GetXid();
1550         cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
1551         pTcon = cifs_sb->tcon;
1552
1553         if (file->private_data == NULL) {
1554                 FreeXid(xid);
1555                 return -EBADF;
1556         }
1557         open_file = (struct cifsFileInfo *)file->private_data;
1558
1559         if ((file->f_flags & O_ACCMODE) == O_WRONLY) {
1560                 cFYI(1, ("attempting read on write only file instance"));
1561         }
1562         for (total_read = 0, current_offset = read_data;
1563              read_size > total_read;
1564              total_read += bytes_read, current_offset += bytes_read) {
1565                 current_read_size = min_t(const int, read_size - total_read,
1566                                           cifs_sb->rsize);
1567                 rc = -EAGAIN;
1568                 smb_read_data = NULL;
1569                 while (rc == -EAGAIN) {
1570                         int buf_type = CIFS_NO_BUFFER;
1571                         if ((open_file->invalidHandle) &&
1572                             (!open_file->closePend)) {
1573                                 rc = cifs_reopen_file(file->f_path.dentry->d_inode,
1574                                         file, TRUE);
1575                                 if (rc != 0)
1576                                         break;
1577                         }
1578                         rc = CIFSSMBRead(xid, pTcon,
1579                                          open_file->netfid,
1580                                          current_read_size, *poffset,
1581                                          &bytes_read, &smb_read_data,
1582                                          &buf_type);
1583                         pSMBr = (struct smb_com_read_rsp *)smb_read_data;
1584                         if (smb_read_data) {
1585                                 if (copy_to_user(current_offset,
1586                                                 smb_read_data +
1587                                                 4 /* RFC1001 length field */ +
1588                                                 le16_to_cpu(pSMBr->DataOffset),
1589                                                 bytes_read)) {
1590                                         rc = -EFAULT;
1591                                 }
1592
1593                                 if(buf_type == CIFS_SMALL_BUFFER)
1594                                         cifs_small_buf_release(smb_read_data);
1595                                 else if(buf_type == CIFS_LARGE_BUFFER)
1596                                         cifs_buf_release(smb_read_data);
1597                                 smb_read_data = NULL;
1598                         }
1599                 }
1600                 if (rc || (bytes_read == 0)) {
1601                         if (total_read) {
1602                                 break;
1603                         } else {
1604                                 FreeXid(xid);
1605                                 return rc;
1606                         }
1607                 } else {
1608                         cifs_stats_bytes_read(pTcon, bytes_read);
1609                         *poffset += bytes_read;
1610                 }
1611         }
1612         FreeXid(xid);
1613         return total_read;
1614 }
1615
1616
1617 static ssize_t cifs_read(struct file *file, char *read_data, size_t read_size,
1618         loff_t *poffset)
1619 {
1620         int rc = -EACCES;
1621         unsigned int bytes_read = 0;
1622         unsigned int total_read;
1623         unsigned int current_read_size;
1624         struct cifs_sb_info *cifs_sb;
1625         struct cifsTconInfo *pTcon;
1626         int xid;
1627         char *current_offset;
1628         struct cifsFileInfo *open_file;
1629         int buf_type = CIFS_NO_BUFFER;
1630
1631         xid = GetXid();
1632         cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
1633         pTcon = cifs_sb->tcon;
1634
1635         if (file->private_data == NULL) {
1636                 FreeXid(xid);
1637                 return -EBADF;
1638         }
1639         open_file = (struct cifsFileInfo *)file->private_data;
1640
1641         if ((file->f_flags & O_ACCMODE) == O_WRONLY)
1642                 cFYI(1, ("attempting read on write only file instance"));
1643
1644         for (total_read = 0, current_offset = read_data;
1645              read_size > total_read;
1646              total_read += bytes_read, current_offset += bytes_read) {
1647                 current_read_size = min_t(const int, read_size - total_read,
1648                                           cifs_sb->rsize);
1649                 /* For windows me and 9x we do not want to request more
1650                 than it negotiated since it will refuse the read then */
1651                 if((pTcon->ses) &&
1652                         !(pTcon->ses->capabilities & CAP_LARGE_FILES)) {
1653                         current_read_size = min_t(const int, current_read_size,
1654                                         pTcon->ses->server->maxBuf - 128);
1655                 }
1656                 rc = -EAGAIN;
1657                 while (rc == -EAGAIN) {
1658                         if ((open_file->invalidHandle) &&
1659                             (!open_file->closePend)) {
1660                                 rc = cifs_reopen_file(file->f_path.dentry->d_inode,
1661                                         file, TRUE);
1662                                 if (rc != 0)
1663                                         break;
1664                         }
1665                         rc = CIFSSMBRead(xid, pTcon,
1666                                          open_file->netfid,
1667                                          current_read_size, *poffset,
1668                                          &bytes_read, &current_offset,
1669                                          &buf_type);
1670                 }
1671                 if (rc || (bytes_read == 0)) {
1672                         if (total_read) {
1673                                 break;
1674                         } else {
1675                                 FreeXid(xid);
1676                                 return rc;
1677                         }
1678                 } else {
1679                         cifs_stats_bytes_read(pTcon, total_read);
1680                         *poffset += bytes_read;
1681                 }
1682         }
1683         FreeXid(xid);
1684         return total_read;
1685 }
1686
1687 int cifs_file_mmap(struct file *file, struct vm_area_struct *vma)
1688 {
1689         struct dentry *dentry = file->f_path.dentry;
1690         int rc, xid;
1691
1692         xid = GetXid();
1693         rc = cifs_revalidate(dentry);
1694         if (rc) {
1695                 cFYI(1, ("Validation prior to mmap failed, error=%d", rc));
1696                 FreeXid(xid);
1697                 return rc;
1698         }
1699         rc = generic_file_mmap(file, vma);
1700         FreeXid(xid);
1701         return rc;
1702 }
1703
1704
1705 static void cifs_copy_cache_pages(struct address_space *mapping,
1706         struct list_head *pages, int bytes_read, char *data,
1707         struct pagevec *plru_pvec)
1708 {
1709         struct page *page;
1710         char *target;
1711
1712         while (bytes_read > 0) {
1713                 if (list_empty(pages))
1714                         break;
1715
1716                 page = list_entry(pages->prev, struct page, lru);
1717                 list_del(&page->lru);
1718
1719                 if (add_to_page_cache(page, mapping, page->index,
1720                                       GFP_KERNEL)) {
1721                         page_cache_release(page);
1722                         cFYI(1, ("Add page cache failed"));
1723                         data += PAGE_CACHE_SIZE;
1724                         bytes_read -= PAGE_CACHE_SIZE;
1725                         continue;
1726                 }
1727
1728                 target = kmap_atomic(page,KM_USER0);
1729
1730                 if (PAGE_CACHE_SIZE > bytes_read) {
1731                         memcpy(target, data, bytes_read);
1732                         /* zero the tail end of this partial page */
1733                         memset(target + bytes_read, 0,
1734                                PAGE_CACHE_SIZE - bytes_read);
1735                         bytes_read = 0;
1736                 } else {
1737                         memcpy(target, data, PAGE_CACHE_SIZE);
1738                         bytes_read -= PAGE_CACHE_SIZE;
1739                 }
1740                 kunmap_atomic(target, KM_USER0);
1741
1742                 flush_dcache_page(page);
1743                 SetPageUptodate(page);
1744                 unlock_page(page);
1745                 if (!pagevec_add(plru_pvec, page))
1746                         __pagevec_lru_add(plru_pvec);
1747                 data += PAGE_CACHE_SIZE;
1748         }
1749         return;
1750 }
1751
1752 static int cifs_readpages(struct file *file, struct address_space *mapping,
1753         struct list_head *page_list, unsigned num_pages)
1754 {
1755         int rc = -EACCES;
1756         int xid;
1757         loff_t offset;
1758         struct page *page;
1759         struct cifs_sb_info *cifs_sb;
1760         struct cifsTconInfo *pTcon;
1761         int bytes_read = 0;
1762         unsigned int read_size,i;
1763         char *smb_read_data = NULL;
1764         struct smb_com_read_rsp *pSMBr;
1765         struct pagevec lru_pvec;
1766         struct cifsFileInfo *open_file;
1767         int buf_type = CIFS_NO_BUFFER;
1768
1769         xid = GetXid();
1770         if (file->private_data == NULL) {
1771                 FreeXid(xid);
1772                 return -EBADF;
1773         }
1774         open_file = (struct cifsFileInfo *)file->private_data;
1775         cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
1776         pTcon = cifs_sb->tcon;
1777
1778         pagevec_init(&lru_pvec, 0);
1779
1780         for (i = 0; i < num_pages; ) {
1781                 unsigned contig_pages;
1782                 struct page *tmp_page;
1783                 unsigned long expected_index;
1784
1785                 if (list_empty(page_list))
1786                         break;
1787
1788                 page = list_entry(page_list->prev, struct page, lru);
1789                 offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
1790
1791                 /* count adjacent pages that we will read into */
1792                 contig_pages = 0;
1793                 expected_index =
1794                         list_entry(page_list->prev, struct page, lru)->index;
1795                 list_for_each_entry_reverse(tmp_page,page_list,lru) {
1796                         if (tmp_page->index == expected_index) {
1797                                 contig_pages++;
1798                                 expected_index++;
1799                         } else
1800                                 break;
1801                 }
1802                 if (contig_pages + i >  num_pages)
1803                         contig_pages = num_pages - i;
1804
1805                 /* for reads over a certain size could initiate async
1806                    read ahead */
1807
1808                 read_size = contig_pages * PAGE_CACHE_SIZE;
1809                 /* Read size needs to be in multiples of one page */
1810                 read_size = min_t(const unsigned int, read_size,
1811                                   cifs_sb->rsize & PAGE_CACHE_MASK);
1812
1813                 rc = -EAGAIN;
1814                 while (rc == -EAGAIN) {
1815                         if ((open_file->invalidHandle) &&
1816                             (!open_file->closePend)) {
1817                                 rc = cifs_reopen_file(file->f_path.dentry->d_inode,
1818                                         file, TRUE);
1819                                 if (rc != 0)
1820                                         break;
1821                         }
1822
1823                         rc = CIFSSMBRead(xid, pTcon,
1824                                          open_file->netfid,
1825                                          read_size, offset,
1826                                          &bytes_read, &smb_read_data,
1827                                          &buf_type);
1828                         /* BB more RC checks ? */
1829                         if (rc== -EAGAIN) {
1830                                 if (smb_read_data) {
1831                                         if(buf_type == CIFS_SMALL_BUFFER)
1832                                                 cifs_small_buf_release(smb_read_data);
1833                                         else if(buf_type == CIFS_LARGE_BUFFER)
1834                                                 cifs_buf_release(smb_read_data);
1835                                         smb_read_data = NULL;
1836                                 }
1837                         }
1838                 }
1839                 if ((rc < 0) || (smb_read_data == NULL)) {
1840                         cFYI(1, ("Read error in readpages: %d", rc));
1841                         break;
1842                 } else if (bytes_read > 0) {
1843                         task_io_account_read(bytes_read);
1844                         pSMBr = (struct smb_com_read_rsp *)smb_read_data;
1845                         cifs_copy_cache_pages(mapping, page_list, bytes_read,
1846                                 smb_read_data + 4 /* RFC1001 hdr */ +
1847                                 le16_to_cpu(pSMBr->DataOffset), &lru_pvec);
1848
1849                         i +=  bytes_read >> PAGE_CACHE_SHIFT;
1850                         cifs_stats_bytes_read(pTcon, bytes_read);
1851                         if ((int)(bytes_read & PAGE_CACHE_MASK) != bytes_read) {
1852                                 i++; /* account for partial page */
1853
1854                                 /* server copy of file can have smaller size
1855                                    than client */
1856                                 /* BB do we need to verify this common case ?
1857                                    this case is ok - if we are at server EOF
1858                                    we will hit it on next read */
1859
1860                                 /* break; */
1861                         }
1862                 } else {
1863                         cFYI(1, ("No bytes read (%d) at offset %lld . "
1864                                  "Cleaning remaining pages from readahead list",
1865                                  bytes_read, offset));
1866                         /* BB turn off caching and do new lookup on
1867                            file size at server? */
1868                         break;
1869                 }
1870                 if (smb_read_data) {
1871                         if(buf_type == CIFS_SMALL_BUFFER)
1872                                 cifs_small_buf_release(smb_read_data);
1873                         else if(buf_type == CIFS_LARGE_BUFFER)
1874                                 cifs_buf_release(smb_read_data);
1875                         smb_read_data = NULL;
1876                 }
1877                 bytes_read = 0;
1878         }
1879
1880         pagevec_lru_add(&lru_pvec);
1881
1882 /* need to free smb_read_data buf before exit */
1883         if (smb_read_data) {
1884                 if(buf_type == CIFS_SMALL_BUFFER)
1885                         cifs_small_buf_release(smb_read_data);
1886                 else if(buf_type == CIFS_LARGE_BUFFER)
1887                         cifs_buf_release(smb_read_data);
1888                 smb_read_data = NULL;
1889         }
1890
1891         FreeXid(xid);
1892         return rc;
1893 }
1894
1895 static int cifs_readpage_worker(struct file *file, struct page *page,
1896         loff_t *poffset)
1897 {
1898         char *read_data;
1899         int rc;
1900
1901         page_cache_get(page);
1902         read_data = kmap(page);
1903         /* for reads over a certain size could initiate async read ahead */
1904
1905         rc = cifs_read(file, read_data, PAGE_CACHE_SIZE, poffset);
1906
1907         if (rc < 0)
1908                 goto io_error;
1909         else
1910                 cFYI(1, ("Bytes read %d",rc));
1911
1912         file->f_path.dentry->d_inode->i_atime =
1913                 current_fs_time(file->f_path.dentry->d_inode->i_sb);
1914
1915         if (PAGE_CACHE_SIZE > rc)
1916                 memset(read_data + rc, 0, PAGE_CACHE_SIZE - rc);
1917
1918         flush_dcache_page(page);
1919         SetPageUptodate(page);
1920         rc = 0;
1921
1922 io_error:
1923         kunmap(page);
1924         page_cache_release(page);
1925         return rc;
1926 }
1927
1928 static int cifs_readpage(struct file *file, struct page *page)
1929 {
1930         loff_t offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
1931         int rc = -EACCES;
1932         int xid;
1933
1934         xid = GetXid();
1935
1936         if (file->private_data == NULL) {
1937                 FreeXid(xid);
1938                 return -EBADF;
1939         }
1940
1941         cFYI(1, ("readpage %p at offset %d 0x%x\n",
1942                  page, (int)offset, (int)offset));
1943
1944         rc = cifs_readpage_worker(file, page, &offset);
1945
1946         unlock_page(page);
1947
1948         FreeXid(xid);
1949         return rc;
1950 }
1951
1952 /* We do not want to update the file size from server for inodes
1953    open for write - to avoid races with writepage extending
1954    the file - in the future we could consider allowing
1955    refreshing the inode only on increases in the file size
1956    but this is tricky to do without racing with writebehind
1957    page caching in the current Linux kernel design */
1958 int is_size_safe_to_change(struct cifsInodeInfo *cifsInode, __u64 end_of_file)
1959 {
1960         struct cifsFileInfo *open_file = NULL;
1961
1962         if (cifsInode)
1963                 open_file =  find_writable_file(cifsInode);
1964
1965         if(open_file) {
1966                 struct cifs_sb_info *cifs_sb;
1967
1968                 /* there is not actually a write pending so let
1969                 this handle go free and allow it to
1970                 be closable if needed */
1971                 atomic_dec(&open_file->wrtPending);
1972
1973                 cifs_sb = CIFS_SB(cifsInode->vfs_inode.i_sb);
1974                 if ( cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DIRECT_IO ) {
1975                         /* since no page cache to corrupt on directio
1976                         we can change size safely */
1977                         return 1;
1978                 }
1979
1980                 if(i_size_read(&cifsInode->vfs_inode) < end_of_file)
1981                         return 1;
1982
1983                 return 0;
1984         } else
1985                 return 1;
1986 }
1987
1988 static int cifs_prepare_write(struct file *file, struct page *page,
1989         unsigned from, unsigned to)
1990 {
1991         int rc = 0;
1992         loff_t offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
1993         cFYI(1, ("prepare write for page %p from %d to %d",page,from,to));
1994         if (!PageUptodate(page)) {
1995         /*      if (to - from != PAGE_CACHE_SIZE) {
1996                         void *kaddr = kmap_atomic(page, KM_USER0);
1997                         memset(kaddr, 0, from);
1998                         memset(kaddr + to, 0, PAGE_CACHE_SIZE - to);
1999                         flush_dcache_page(page);
2000                         kunmap_atomic(kaddr, KM_USER0);
2001                 } */
2002                 /* If we are writing a full page it will be up to date,
2003                    no need to read from the server */
2004                 if ((to == PAGE_CACHE_SIZE) && (from == 0))
2005                         SetPageUptodate(page);
2006
2007                 /* might as well read a page, it is fast enough */
2008                 if ((file->f_flags & O_ACCMODE) != O_WRONLY) {
2009                         rc = cifs_readpage_worker(file, page, &offset);
2010                 } else {
2011                 /* should we try using another file handle if there is one -
2012                    how would we lock it to prevent close of that handle
2013                    racing with this read?
2014                    In any case this will be written out by commit_write */
2015                 }
2016         }
2017
2018         /* BB should we pass any errors back?
2019            e.g. if we do not have read access to the file */
2020         return 0;
2021 }
2022
2023 const struct address_space_operations cifs_addr_ops = {
2024         .readpage = cifs_readpage,
2025         .readpages = cifs_readpages,
2026         .writepage = cifs_writepage,
2027         .writepages = cifs_writepages,
2028         .prepare_write = cifs_prepare_write,
2029         .commit_write = cifs_commit_write,
2030         .set_page_dirty = __set_page_dirty_nobuffers,
2031         /* .sync_page = cifs_sync_page, */
2032         /* .direct_IO = */
2033 };
2034
2035 /*
2036  * cifs_readpages requires the server to support a buffer large enough to
2037  * contain the header plus one complete page of data.  Otherwise, we need
2038  * to leave cifs_readpages out of the address space operations.
2039  */
2040 const struct address_space_operations cifs_addr_ops_smallbuf = {
2041         .readpage = cifs_readpage,
2042         .writepage = cifs_writepage,
2043         .writepages = cifs_writepages,
2044         .prepare_write = cifs_prepare_write,
2045         .commit_write = cifs_commit_write,
2046         .set_page_dirty = __set_page_dirty_nobuffers,
2047         /* .sync_page = cifs_sync_page, */
2048         /* .direct_IO = */
2049 };