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                         file->f_path.dentry->d_inode->i_ctime =
1018                         file->f_path.dentry->d_inode->i_mtime = CURRENT_TIME;
1019                         if (total_written > 0) {
1020                                 if (*poffset > file->f_path.dentry->d_inode->i_size)
1021                                         i_size_write(file->f_path.dentry->d_inode,
1022                                                      *poffset);
1023                         }
1024                         mark_inode_dirty_sync(file->f_path.dentry->d_inode);
1025                 }
1026         }
1027         FreeXid(xid);
1028         return total_written;
1029 }
1030
1031 struct cifsFileInfo *find_writable_file(struct cifsInodeInfo *cifs_inode)
1032 {
1033         struct cifsFileInfo *open_file;
1034         int rc;
1035
1036         /* Having a null inode here (because mapping->host was set to zero by
1037         the VFS or MM) should not happen but we had reports of on oops (due to
1038         it being zero) during stress testcases so we need to check for it */
1039
1040         if(cifs_inode == NULL) {
1041                 cERROR(1,("Null inode passed to cifs_writeable_file"));
1042                 dump_stack();
1043                 return NULL;
1044         }
1045
1046         read_lock(&GlobalSMBSeslock);
1047         list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
1048                 if (open_file->closePend)
1049                         continue;
1050                 if (open_file->pfile &&
1051                     ((open_file->pfile->f_flags & O_RDWR) ||
1052                      (open_file->pfile->f_flags & O_WRONLY))) {
1053                         atomic_inc(&open_file->wrtPending);
1054                         read_unlock(&GlobalSMBSeslock);
1055                         if((open_file->invalidHandle) &&
1056                            (!open_file->closePend) /* BB fixme -since the second clause can not be true remove it BB */) {
1057                                 rc = cifs_reopen_file(&cifs_inode->vfs_inode,
1058                                                       open_file->pfile, FALSE);
1059                                 /* if it fails, try another handle - might be */
1060                                 /* dangerous to hold up writepages with retry */
1061                                 if(rc) {
1062                                         cFYI(1,("failed on reopen file in wp"));
1063                                         read_lock(&GlobalSMBSeslock);
1064                                         /* can not use this handle, no write
1065                                         pending on this one after all */
1066                                         atomic_dec
1067                                              (&open_file->wrtPending);
1068                                         continue;
1069                                 }
1070                         }
1071                         return open_file;
1072                 }
1073         }
1074         read_unlock(&GlobalSMBSeslock);
1075         return NULL;
1076 }
1077
1078 static int cifs_partialpagewrite(struct page *page, unsigned from, unsigned to)
1079 {
1080         struct address_space *mapping = page->mapping;
1081         loff_t offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
1082         char *write_data;
1083         int rc = -EFAULT;
1084         int bytes_written = 0;
1085         struct cifs_sb_info *cifs_sb;
1086         struct cifsTconInfo *pTcon;
1087         struct inode *inode;
1088         struct cifsFileInfo *open_file;
1089
1090         if (!mapping || !mapping->host)
1091                 return -EFAULT;
1092
1093         inode = page->mapping->host;
1094         cifs_sb = CIFS_SB(inode->i_sb);
1095         pTcon = cifs_sb->tcon;
1096
1097         offset += (loff_t)from;
1098         write_data = kmap(page);
1099         write_data += from;
1100
1101         if ((to > PAGE_CACHE_SIZE) || (from > to)) {
1102                 kunmap(page);
1103                 return -EIO;
1104         }
1105
1106         /* racing with truncate? */
1107         if (offset > mapping->host->i_size) {
1108                 kunmap(page);
1109                 return 0; /* don't care */
1110         }
1111
1112         /* check to make sure that we are not extending the file */
1113         if (mapping->host->i_size - offset < (loff_t)to)
1114                 to = (unsigned)(mapping->host->i_size - offset);
1115
1116         open_file = find_writable_file(CIFS_I(mapping->host));
1117         if (open_file) {
1118                 bytes_written = cifs_write(open_file->pfile, write_data,
1119                                            to-from, &offset);
1120                 atomic_dec(&open_file->wrtPending);
1121                 /* Does mm or vfs already set times? */
1122                 inode->i_atime = inode->i_mtime = current_fs_time(inode->i_sb);
1123                 if ((bytes_written > 0) && (offset)) {
1124                         rc = 0;
1125                 } else if (bytes_written < 0) {
1126                         if (rc != -EBADF)
1127                                 rc = bytes_written;
1128                 }
1129         } else {
1130                 cFYI(1, ("No writeable filehandles for inode"));
1131                 rc = -EIO;
1132         }
1133
1134         kunmap(page);
1135         return rc;
1136 }
1137
1138 static int cifs_writepages(struct address_space *mapping,
1139                            struct writeback_control *wbc)
1140 {
1141         struct backing_dev_info *bdi = mapping->backing_dev_info;
1142         unsigned int bytes_to_write;
1143         unsigned int bytes_written;
1144         struct cifs_sb_info *cifs_sb;
1145         int done = 0;
1146         pgoff_t end;
1147         pgoff_t index;
1148         int range_whole = 0;
1149         struct kvec iov[32];
1150         int len;
1151         int n_iov = 0;
1152         pgoff_t next;
1153         int nr_pages;
1154         __u64 offset = 0;
1155         struct cifsFileInfo *open_file;
1156         struct page *page;
1157         struct pagevec pvec;
1158         int rc = 0;
1159         int scanned = 0;
1160         int xid;
1161
1162         cifs_sb = CIFS_SB(mapping->host->i_sb);
1163
1164         /*
1165          * If wsize is smaller that the page cache size, default to writing
1166          * one page at a time via cifs_writepage
1167          */
1168         if (cifs_sb->wsize < PAGE_CACHE_SIZE)
1169                 return generic_writepages(mapping, wbc);
1170
1171         if((cifs_sb->tcon->ses) && (cifs_sb->tcon->ses->server))
1172                 if(cifs_sb->tcon->ses->server->secMode &
1173                           (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED))
1174                         if(!experimEnabled)
1175                                 return generic_writepages(mapping, wbc);
1176
1177         /*
1178          * BB: Is this meaningful for a non-block-device file system?
1179          * If it is, we should test it again after we do I/O
1180          */
1181         if (wbc->nonblocking && bdi_write_congested(bdi)) {
1182                 wbc->encountered_congestion = 1;
1183                 return 0;
1184         }
1185
1186         xid = GetXid();
1187
1188         pagevec_init(&pvec, 0);
1189         if (wbc->range_cyclic) {
1190                 index = mapping->writeback_index; /* Start from prev offset */
1191                 end = -1;
1192         } else {
1193                 index = wbc->range_start >> PAGE_CACHE_SHIFT;
1194                 end = wbc->range_end >> PAGE_CACHE_SHIFT;
1195                 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
1196                         range_whole = 1;
1197                 scanned = 1;
1198         }
1199 retry:
1200         while (!done && (index <= end) &&
1201                (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
1202                         PAGECACHE_TAG_DIRTY,
1203                         min(end - index, (pgoff_t)PAGEVEC_SIZE - 1) + 1))) {
1204                 int first;
1205                 unsigned int i;
1206
1207                 first = -1;
1208                 next = 0;
1209                 n_iov = 0;
1210                 bytes_to_write = 0;
1211
1212                 for (i = 0; i < nr_pages; i++) {
1213                         page = pvec.pages[i];
1214                         /*
1215                          * At this point we hold neither mapping->tree_lock nor
1216                          * lock on the page itself: the page may be truncated or
1217                          * invalidated (changing page->mapping to NULL), or even
1218                          * swizzled back from swapper_space to tmpfs file
1219                          * mapping
1220                          */
1221
1222                         if (first < 0)
1223                                 lock_page(page);
1224                         else if (TestSetPageLocked(page))
1225                                 break;
1226
1227                         if (unlikely(page->mapping != mapping)) {
1228                                 unlock_page(page);
1229                                 break;
1230                         }
1231
1232                         if (!wbc->range_cyclic && page->index > end) {
1233                                 done = 1;
1234                                 unlock_page(page);
1235                                 break;
1236                         }
1237
1238                         if (next && (page->index != next)) {
1239                                 /* Not next consecutive page */
1240                                 unlock_page(page);
1241                                 break;
1242                         }
1243
1244                         if (wbc->sync_mode != WB_SYNC_NONE)
1245                                 wait_on_page_writeback(page);
1246
1247                         if (PageWriteback(page) ||
1248                                         !clear_page_dirty_for_io(page)) {
1249                                 unlock_page(page);
1250                                 break;
1251                         }
1252
1253                         /*
1254                          * This actually clears the dirty bit in the radix tree.
1255                          * See cifs_writepage() for more commentary.
1256                          */
1257                         set_page_writeback(page);
1258
1259                         if (page_offset(page) >= mapping->host->i_size) {
1260                                 done = 1;
1261                                 unlock_page(page);
1262                                 end_page_writeback(page);
1263                                 break;
1264                         }
1265
1266                         /*
1267                          * BB can we get rid of this?  pages are held by pvec
1268                          */
1269                         page_cache_get(page);
1270
1271                         len = min(mapping->host->i_size - page_offset(page),
1272                                   (loff_t)PAGE_CACHE_SIZE);
1273
1274                         /* reserve iov[0] for the smb header */
1275                         n_iov++;
1276                         iov[n_iov].iov_base = kmap(page);
1277                         iov[n_iov].iov_len = len;
1278                         bytes_to_write += len;
1279
1280                         if (first < 0) {
1281                                 first = i;
1282                                 offset = page_offset(page);
1283                         }
1284                         next = page->index + 1;
1285                         if (bytes_to_write + PAGE_CACHE_SIZE > cifs_sb->wsize)
1286                                 break;
1287                 }
1288                 if (n_iov) {
1289                         /* Search for a writable handle every time we call
1290                          * CIFSSMBWrite2.  We can't rely on the last handle
1291                          * we used to still be valid
1292                          */
1293                         open_file = find_writable_file(CIFS_I(mapping->host));
1294                         if (!open_file) {
1295                                 cERROR(1, ("No writable handles for inode"));
1296                                 rc = -EBADF;
1297                         } else {
1298                                 rc = CIFSSMBWrite2(xid, cifs_sb->tcon,
1299                                                    open_file->netfid,
1300                                                    bytes_to_write, offset,
1301                                                    &bytes_written, iov, n_iov,
1302                                                    1);
1303                                 atomic_dec(&open_file->wrtPending);
1304                                 if (rc || bytes_written < bytes_to_write) {
1305                                         cERROR(1,("Write2 ret %d, written = %d",
1306                                                   rc, bytes_written));
1307                                         /* BB what if continued retry is
1308                                            requested via mount flags? */
1309                                         set_bit(AS_EIO, &mapping->flags);
1310                                 } else {
1311                                         cifs_stats_bytes_written(cifs_sb->tcon,
1312                                                                  bytes_written);
1313                                 }
1314                         }
1315                         for (i = 0; i < n_iov; i++) {
1316                                 page = pvec.pages[first + i];
1317                                 /* Should we also set page error on
1318                                 success rc but too little data written? */
1319                                 /* BB investigate retry logic on temporary
1320                                 server crash cases and how recovery works
1321                                 when page marked as error */
1322                                 if(rc)
1323                                         SetPageError(page);
1324                                 kunmap(page);
1325                                 unlock_page(page);
1326                                 end_page_writeback(page);
1327                                 page_cache_release(page);
1328                         }
1329                         if ((wbc->nr_to_write -= n_iov) <= 0)
1330                                 done = 1;
1331                         index = next;
1332                 }
1333                 pagevec_release(&pvec);
1334         }
1335         if (!scanned && !done) {
1336                 /*
1337                  * We hit the last page and there is more work to be done: wrap
1338                  * back to the start of the file
1339                  */
1340                 scanned = 1;
1341                 index = 0;
1342                 goto retry;
1343         }
1344         if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
1345                 mapping->writeback_index = index;
1346
1347         FreeXid(xid);
1348
1349         return rc;
1350 }
1351
1352 static int cifs_writepage(struct page* page, struct writeback_control *wbc)
1353 {
1354         int rc = -EFAULT;
1355         int xid;
1356
1357         xid = GetXid();
1358 /* BB add check for wbc flags */
1359         page_cache_get(page);
1360         if (!PageUptodate(page)) {
1361                 cFYI(1, ("ppw - page not up to date"));
1362         }
1363
1364         /*
1365          * Set the "writeback" flag, and clear "dirty" in the radix tree.
1366          *
1367          * A writepage() implementation always needs to do either this,
1368          * or re-dirty the page with "redirty_page_for_writepage()" in
1369          * the case of a failure.
1370          *
1371          * Just unlocking the page will cause the radix tree tag-bits
1372          * to fail to update with the state of the page correctly.
1373          */
1374         set_page_writeback(page);
1375         rc = cifs_partialpagewrite(page, 0, PAGE_CACHE_SIZE);
1376         SetPageUptodate(page); /* BB add check for error and Clearuptodate? */
1377         unlock_page(page);
1378         end_page_writeback(page);
1379         page_cache_release(page);
1380         FreeXid(xid);
1381         return rc;
1382 }
1383
1384 static int cifs_commit_write(struct file *file, struct page *page,
1385         unsigned offset, unsigned to)
1386 {
1387         int xid;
1388         int rc = 0;
1389         struct inode *inode = page->mapping->host;
1390         loff_t position = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
1391         char *page_data;
1392
1393         xid = GetXid();
1394         cFYI(1, ("commit write for page %p up to position %lld for %d",
1395                  page, position, to));
1396         if (position > inode->i_size) {
1397                 i_size_write(inode, position);
1398                 /* if (file->private_data == NULL) {
1399                         rc = -EBADF;
1400                 } else {
1401                         open_file = (struct cifsFileInfo *)file->private_data;
1402                         cifs_sb = CIFS_SB(inode->i_sb);
1403                         rc = -EAGAIN;
1404                         while (rc == -EAGAIN) {
1405                                 if ((open_file->invalidHandle) &&
1406                                     (!open_file->closePend)) {
1407                                         rc = cifs_reopen_file(
1408                                                 file->f_path.dentry->d_inode, file);
1409                                         if (rc != 0)
1410                                                 break;
1411                                 }
1412                                 if (!open_file->closePend) {
1413                                         rc = CIFSSMBSetFileSize(xid,
1414                                                 cifs_sb->tcon, position,
1415                                                 open_file->netfid,
1416                                                 open_file->pid, FALSE);
1417                                 } else {
1418                                         rc = -EBADF;
1419                                         break;
1420                                 }
1421                         }
1422                         cFYI(1, (" SetEOF (commit write) rc = %d", rc));
1423                 } */
1424         }
1425         if (!PageUptodate(page)) {
1426                 position =  ((loff_t)page->index << PAGE_CACHE_SHIFT) + offset;
1427                 /* can not rely on (or let) writepage write this data */
1428                 if (to < offset) {
1429                         cFYI(1, ("Illegal offsets, can not copy from %d to %d",
1430                                 offset, to));
1431                         FreeXid(xid);
1432                         return rc;
1433                 }
1434                 /* this is probably better than directly calling
1435                    partialpage_write since in this function the file handle is
1436                    known which we might as well leverage */
1437                 /* BB check if anything else missing out of ppw
1438                    such as updating last write time */
1439                 page_data = kmap(page);
1440                 rc = cifs_write(file, page_data + offset, to-offset,
1441                                 &position);
1442                 if (rc > 0)
1443                         rc = 0;
1444                 /* else if (rc < 0) should we set writebehind rc? */
1445                 kunmap(page);
1446         } else {
1447                 set_page_dirty(page);
1448         }
1449
1450         FreeXid(xid);
1451         return rc;
1452 }
1453
1454 int cifs_fsync(struct file *file, struct dentry *dentry, int datasync)
1455 {
1456         int xid;
1457         int rc = 0;
1458         struct inode *inode = file->f_path.dentry->d_inode;
1459
1460         xid = GetXid();
1461
1462         cFYI(1, ("Sync file - name: %s datasync: 0x%x",
1463                 dentry->d_name.name, datasync));
1464
1465         rc = filemap_fdatawrite(inode->i_mapping);
1466         if (rc == 0)
1467                 CIFS_I(inode)->write_behind_rc = 0;
1468         FreeXid(xid);
1469         return rc;
1470 }
1471
1472 /* static void cifs_sync_page(struct page *page)
1473 {
1474         struct address_space *mapping;
1475         struct inode *inode;
1476         unsigned long index = page->index;
1477         unsigned int rpages = 0;
1478         int rc = 0;
1479
1480         cFYI(1, ("sync page %p",page));
1481         mapping = page->mapping;
1482         if (!mapping)
1483                 return 0;
1484         inode = mapping->host;
1485         if (!inode)
1486                 return; */
1487
1488 /*      fill in rpages then
1489         result = cifs_pagein_inode(inode, index, rpages); */ /* BB finish */
1490
1491 /*      cFYI(1, ("rpages is %d for sync page of Index %ld", rpages, index));
1492
1493 #if 0
1494         if (rc < 0)
1495                 return rc;
1496         return 0;
1497 #endif
1498 } */
1499
1500 /*
1501  * As file closes, flush all cached write data for this inode checking
1502  * for write behind errors.
1503  */
1504 int cifs_flush(struct file *file, fl_owner_t id)
1505 {
1506         struct inode * inode = file->f_path.dentry->d_inode;
1507         int rc = 0;
1508
1509         /* Rather than do the steps manually:
1510            lock the inode for writing
1511            loop through pages looking for write behind data (dirty pages)
1512            coalesce into contiguous 16K (or smaller) chunks to write to server
1513            send to server (prefer in parallel)
1514            deal with writebehind errors
1515            unlock inode for writing
1516            filemapfdatawrite appears easier for the time being */
1517
1518         rc = filemap_fdatawrite(inode->i_mapping);
1519         if (!rc) /* reset wb rc if we were able to write out dirty pages */
1520                 CIFS_I(inode)->write_behind_rc = 0;
1521
1522         cFYI(1, ("Flush inode %p file %p rc %d",inode,file,rc));
1523
1524         return rc;
1525 }
1526
1527 ssize_t cifs_user_read(struct file *file, char __user *read_data,
1528         size_t read_size, loff_t *poffset)
1529 {
1530         int rc = -EACCES;
1531         unsigned int bytes_read = 0;
1532         unsigned int total_read = 0;
1533         unsigned int current_read_size;
1534         struct cifs_sb_info *cifs_sb;
1535         struct cifsTconInfo *pTcon;
1536         int xid;
1537         struct cifsFileInfo *open_file;
1538         char *smb_read_data;
1539         char __user *current_offset;
1540         struct smb_com_read_rsp *pSMBr;
1541
1542         xid = GetXid();
1543         cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
1544         pTcon = cifs_sb->tcon;
1545
1546         if (file->private_data == NULL) {
1547                 FreeXid(xid);
1548                 return -EBADF;
1549         }
1550         open_file = (struct cifsFileInfo *)file->private_data;
1551
1552         if ((file->f_flags & O_ACCMODE) == O_WRONLY) {
1553                 cFYI(1, ("attempting read on write only file instance"));
1554         }
1555         for (total_read = 0, current_offset = read_data;
1556              read_size > total_read;
1557              total_read += bytes_read, current_offset += bytes_read) {
1558                 current_read_size = min_t(const int, read_size - total_read,
1559                                           cifs_sb->rsize);
1560                 rc = -EAGAIN;
1561                 smb_read_data = NULL;
1562                 while (rc == -EAGAIN) {
1563                         int buf_type = CIFS_NO_BUFFER;
1564                         if ((open_file->invalidHandle) &&
1565                             (!open_file->closePend)) {
1566                                 rc = cifs_reopen_file(file->f_path.dentry->d_inode,
1567                                         file, TRUE);
1568                                 if (rc != 0)
1569                                         break;
1570                         }
1571                         rc = CIFSSMBRead(xid, pTcon,
1572                                          open_file->netfid,
1573                                          current_read_size, *poffset,
1574                                          &bytes_read, &smb_read_data,
1575                                          &buf_type);
1576                         pSMBr = (struct smb_com_read_rsp *)smb_read_data;
1577                         if (smb_read_data) {
1578                                 if (copy_to_user(current_offset,
1579                                                 smb_read_data +
1580                                                 4 /* RFC1001 length field */ +
1581                                                 le16_to_cpu(pSMBr->DataOffset),
1582                                                 bytes_read)) {
1583                                         rc = -EFAULT;
1584                                 }
1585
1586                                 if(buf_type == CIFS_SMALL_BUFFER)
1587                                         cifs_small_buf_release(smb_read_data);
1588                                 else if(buf_type == CIFS_LARGE_BUFFER)
1589                                         cifs_buf_release(smb_read_data);
1590                                 smb_read_data = NULL;
1591                         }
1592                 }
1593                 if (rc || (bytes_read == 0)) {
1594                         if (total_read) {
1595                                 break;
1596                         } else {
1597                                 FreeXid(xid);
1598                                 return rc;
1599                         }
1600                 } else {
1601                         cifs_stats_bytes_read(pTcon, bytes_read);
1602                         *poffset += bytes_read;
1603                 }
1604         }
1605         FreeXid(xid);
1606         return total_read;
1607 }
1608
1609
1610 static ssize_t cifs_read(struct file *file, char *read_data, size_t read_size,
1611         loff_t *poffset)
1612 {
1613         int rc = -EACCES;
1614         unsigned int bytes_read = 0;
1615         unsigned int total_read;
1616         unsigned int current_read_size;
1617         struct cifs_sb_info *cifs_sb;
1618         struct cifsTconInfo *pTcon;
1619         int xid;
1620         char *current_offset;
1621         struct cifsFileInfo *open_file;
1622         int buf_type = CIFS_NO_BUFFER;
1623
1624         xid = GetXid();
1625         cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
1626         pTcon = cifs_sb->tcon;
1627
1628         if (file->private_data == NULL) {
1629                 FreeXid(xid);
1630                 return -EBADF;
1631         }
1632         open_file = (struct cifsFileInfo *)file->private_data;
1633
1634         if ((file->f_flags & O_ACCMODE) == O_WRONLY)
1635                 cFYI(1, ("attempting read on write only file instance"));
1636
1637         for (total_read = 0, current_offset = read_data;
1638              read_size > total_read;
1639              total_read += bytes_read, current_offset += bytes_read) {
1640                 current_read_size = min_t(const int, read_size - total_read,
1641                                           cifs_sb->rsize);
1642                 /* For windows me and 9x we do not want to request more
1643                 than it negotiated since it will refuse the read then */
1644                 if((pTcon->ses) &&
1645                         !(pTcon->ses->capabilities & CAP_LARGE_FILES)) {
1646                         current_read_size = min_t(const int, current_read_size,
1647                                         pTcon->ses->server->maxBuf - 128);
1648                 }
1649                 rc = -EAGAIN;
1650                 while (rc == -EAGAIN) {
1651                         if ((open_file->invalidHandle) &&
1652                             (!open_file->closePend)) {
1653                                 rc = cifs_reopen_file(file->f_path.dentry->d_inode,
1654                                         file, TRUE);
1655                                 if (rc != 0)
1656                                         break;
1657                         }
1658                         rc = CIFSSMBRead(xid, pTcon,
1659                                          open_file->netfid,
1660                                          current_read_size, *poffset,
1661                                          &bytes_read, &current_offset,
1662                                          &buf_type);
1663                 }
1664                 if (rc || (bytes_read == 0)) {
1665                         if (total_read) {
1666                                 break;
1667                         } else {
1668                                 FreeXid(xid);
1669                                 return rc;
1670                         }
1671                 } else {
1672                         cifs_stats_bytes_read(pTcon, total_read);
1673                         *poffset += bytes_read;
1674                 }
1675         }
1676         FreeXid(xid);
1677         return total_read;
1678 }
1679
1680 int cifs_file_mmap(struct file *file, struct vm_area_struct *vma)
1681 {
1682         struct dentry *dentry = file->f_path.dentry;
1683         int rc, xid;
1684
1685         xid = GetXid();
1686         rc = cifs_revalidate(dentry);
1687         if (rc) {
1688                 cFYI(1, ("Validation prior to mmap failed, error=%d", rc));
1689                 FreeXid(xid);
1690                 return rc;
1691         }
1692         rc = generic_file_mmap(file, vma);
1693         FreeXid(xid);
1694         return rc;
1695 }
1696
1697
1698 static void cifs_copy_cache_pages(struct address_space *mapping,
1699         struct list_head *pages, int bytes_read, char *data,
1700         struct pagevec *plru_pvec)
1701 {
1702         struct page *page;
1703         char *target;
1704
1705         while (bytes_read > 0) {
1706                 if (list_empty(pages))
1707                         break;
1708
1709                 page = list_entry(pages->prev, struct page, lru);
1710                 list_del(&page->lru);
1711
1712                 if (add_to_page_cache(page, mapping, page->index,
1713                                       GFP_KERNEL)) {
1714                         page_cache_release(page);
1715                         cFYI(1, ("Add page cache failed"));
1716                         data += PAGE_CACHE_SIZE;
1717                         bytes_read -= PAGE_CACHE_SIZE;
1718                         continue;
1719                 }
1720
1721                 target = kmap_atomic(page,KM_USER0);
1722
1723                 if (PAGE_CACHE_SIZE > bytes_read) {
1724                         memcpy(target, data, bytes_read);
1725                         /* zero the tail end of this partial page */
1726                         memset(target + bytes_read, 0,
1727                                PAGE_CACHE_SIZE - bytes_read);
1728                         bytes_read = 0;
1729                 } else {
1730                         memcpy(target, data, PAGE_CACHE_SIZE);
1731                         bytes_read -= PAGE_CACHE_SIZE;
1732                 }
1733                 kunmap_atomic(target, KM_USER0);
1734
1735                 flush_dcache_page(page);
1736                 SetPageUptodate(page);
1737                 unlock_page(page);
1738                 if (!pagevec_add(plru_pvec, page))
1739                         __pagevec_lru_add(plru_pvec);
1740                 data += PAGE_CACHE_SIZE;
1741         }
1742         return;
1743 }
1744
1745 static int cifs_readpages(struct file *file, struct address_space *mapping,
1746         struct list_head *page_list, unsigned num_pages)
1747 {
1748         int rc = -EACCES;
1749         int xid;
1750         loff_t offset;
1751         struct page *page;
1752         struct cifs_sb_info *cifs_sb;
1753         struct cifsTconInfo *pTcon;
1754         int bytes_read = 0;
1755         unsigned int read_size,i;
1756         char *smb_read_data = NULL;
1757         struct smb_com_read_rsp *pSMBr;
1758         struct pagevec lru_pvec;
1759         struct cifsFileInfo *open_file;
1760         int buf_type = CIFS_NO_BUFFER;
1761
1762         xid = GetXid();
1763         if (file->private_data == NULL) {
1764                 FreeXid(xid);
1765                 return -EBADF;
1766         }
1767         open_file = (struct cifsFileInfo *)file->private_data;
1768         cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
1769         pTcon = cifs_sb->tcon;
1770
1771         pagevec_init(&lru_pvec, 0);
1772
1773         for (i = 0; i < num_pages; ) {
1774                 unsigned contig_pages;
1775                 struct page *tmp_page;
1776                 unsigned long expected_index;
1777
1778                 if (list_empty(page_list))
1779                         break;
1780
1781                 page = list_entry(page_list->prev, struct page, lru);
1782                 offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
1783
1784                 /* count adjacent pages that we will read into */
1785                 contig_pages = 0;
1786                 expected_index =
1787                         list_entry(page_list->prev, struct page, lru)->index;
1788                 list_for_each_entry_reverse(tmp_page,page_list,lru) {
1789                         if (tmp_page->index == expected_index) {
1790                                 contig_pages++;
1791                                 expected_index++;
1792                         } else
1793                                 break;
1794                 }
1795                 if (contig_pages + i >  num_pages)
1796                         contig_pages = num_pages - i;
1797
1798                 /* for reads over a certain size could initiate async
1799                    read ahead */
1800
1801                 read_size = contig_pages * PAGE_CACHE_SIZE;
1802                 /* Read size needs to be in multiples of one page */
1803                 read_size = min_t(const unsigned int, read_size,
1804                                   cifs_sb->rsize & PAGE_CACHE_MASK);
1805
1806                 rc = -EAGAIN;
1807                 while (rc == -EAGAIN) {
1808                         if ((open_file->invalidHandle) &&
1809                             (!open_file->closePend)) {
1810                                 rc = cifs_reopen_file(file->f_path.dentry->d_inode,
1811                                         file, TRUE);
1812                                 if (rc != 0)
1813                                         break;
1814                         }
1815
1816                         rc = CIFSSMBRead(xid, pTcon,
1817                                          open_file->netfid,
1818                                          read_size, offset,
1819                                          &bytes_read, &smb_read_data,
1820                                          &buf_type);
1821                         /* BB more RC checks ? */
1822                         if (rc== -EAGAIN) {
1823                                 if (smb_read_data) {
1824                                         if(buf_type == CIFS_SMALL_BUFFER)
1825                                                 cifs_small_buf_release(smb_read_data);
1826                                         else if(buf_type == CIFS_LARGE_BUFFER)
1827                                                 cifs_buf_release(smb_read_data);
1828                                         smb_read_data = NULL;
1829                                 }
1830                         }
1831                 }
1832                 if ((rc < 0) || (smb_read_data == NULL)) {
1833                         cFYI(1, ("Read error in readpages: %d", rc));
1834                         break;
1835                 } else if (bytes_read > 0) {
1836                         task_io_account_read(bytes_read);
1837                         pSMBr = (struct smb_com_read_rsp *)smb_read_data;
1838                         cifs_copy_cache_pages(mapping, page_list, bytes_read,
1839                                 smb_read_data + 4 /* RFC1001 hdr */ +
1840                                 le16_to_cpu(pSMBr->DataOffset), &lru_pvec);
1841
1842                         i +=  bytes_read >> PAGE_CACHE_SHIFT;
1843                         cifs_stats_bytes_read(pTcon, bytes_read);
1844                         if ((int)(bytes_read & PAGE_CACHE_MASK) != bytes_read) {
1845                                 i++; /* account for partial page */
1846
1847                                 /* server copy of file can have smaller size
1848                                    than client */
1849                                 /* BB do we need to verify this common case ?
1850                                    this case is ok - if we are at server EOF
1851                                    we will hit it on next read */
1852
1853                                 /* break; */
1854                         }
1855                 } else {
1856                         cFYI(1, ("No bytes read (%d) at offset %lld . "
1857                                  "Cleaning remaining pages from readahead list",
1858                                  bytes_read, offset));
1859                         /* BB turn off caching and do new lookup on
1860                            file size at server? */
1861                         break;
1862                 }
1863                 if (smb_read_data) {
1864                         if(buf_type == CIFS_SMALL_BUFFER)
1865                                 cifs_small_buf_release(smb_read_data);
1866                         else if(buf_type == CIFS_LARGE_BUFFER)
1867                                 cifs_buf_release(smb_read_data);
1868                         smb_read_data = NULL;
1869                 }
1870                 bytes_read = 0;
1871         }
1872
1873         pagevec_lru_add(&lru_pvec);
1874
1875 /* need to free smb_read_data buf before exit */
1876         if (smb_read_data) {
1877                 if(buf_type == CIFS_SMALL_BUFFER)
1878                         cifs_small_buf_release(smb_read_data);
1879                 else if(buf_type == CIFS_LARGE_BUFFER)
1880                         cifs_buf_release(smb_read_data);
1881                 smb_read_data = NULL;
1882         }
1883
1884         FreeXid(xid);
1885         return rc;
1886 }
1887
1888 static int cifs_readpage_worker(struct file *file, struct page *page,
1889         loff_t *poffset)
1890 {
1891         char *read_data;
1892         int rc;
1893
1894         page_cache_get(page);
1895         read_data = kmap(page);
1896         /* for reads over a certain size could initiate async read ahead */
1897
1898         rc = cifs_read(file, read_data, PAGE_CACHE_SIZE, poffset);
1899
1900         if (rc < 0)
1901                 goto io_error;
1902         else
1903                 cFYI(1, ("Bytes read %d",rc));
1904
1905         file->f_path.dentry->d_inode->i_atime =
1906                 current_fs_time(file->f_path.dentry->d_inode->i_sb);
1907
1908         if (PAGE_CACHE_SIZE > rc)
1909                 memset(read_data + rc, 0, PAGE_CACHE_SIZE - rc);
1910
1911         flush_dcache_page(page);
1912         SetPageUptodate(page);
1913         rc = 0;
1914
1915 io_error:
1916         kunmap(page);
1917         page_cache_release(page);
1918         return rc;
1919 }
1920
1921 static int cifs_readpage(struct file *file, struct page *page)
1922 {
1923         loff_t offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
1924         int rc = -EACCES;
1925         int xid;
1926
1927         xid = GetXid();
1928
1929         if (file->private_data == NULL) {
1930                 FreeXid(xid);
1931                 return -EBADF;
1932         }
1933
1934         cFYI(1, ("readpage %p at offset %d 0x%x\n",
1935                  page, (int)offset, (int)offset));
1936
1937         rc = cifs_readpage_worker(file, page, &offset);
1938
1939         unlock_page(page);
1940
1941         FreeXid(xid);
1942         return rc;
1943 }
1944
1945 /* We do not want to update the file size from server for inodes
1946    open for write - to avoid races with writepage extending
1947    the file - in the future we could consider allowing
1948    refreshing the inode only on increases in the file size
1949    but this is tricky to do without racing with writebehind
1950    page caching in the current Linux kernel design */
1951 int is_size_safe_to_change(struct cifsInodeInfo *cifsInode)
1952 {
1953         struct cifsFileInfo *open_file = NULL;
1954
1955         if (cifsInode)
1956                 open_file =  find_writable_file(cifsInode);
1957
1958         if(open_file) {
1959                 struct cifs_sb_info *cifs_sb;
1960
1961                 /* there is not actually a write pending so let
1962                 this handle go free and allow it to
1963                 be closable if needed */
1964                 atomic_dec(&open_file->wrtPending);
1965
1966                 cifs_sb = CIFS_SB(cifsInode->vfs_inode.i_sb);
1967                 if ( cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DIRECT_IO ) {
1968                         /* since no page cache to corrupt on directio
1969                         we can change size safely */
1970                         return 1;
1971                 }
1972
1973                 return 0;
1974         } else
1975                 return 1;
1976 }
1977
1978 static int cifs_prepare_write(struct file *file, struct page *page,
1979         unsigned from, unsigned to)
1980 {
1981         int rc = 0;
1982         loff_t offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
1983         cFYI(1, ("prepare write for page %p from %d to %d",page,from,to));
1984         if (!PageUptodate(page)) {
1985         /*      if (to - from != PAGE_CACHE_SIZE) {
1986                         void *kaddr = kmap_atomic(page, KM_USER0);
1987                         memset(kaddr, 0, from);
1988                         memset(kaddr + to, 0, PAGE_CACHE_SIZE - to);
1989                         flush_dcache_page(page);
1990                         kunmap_atomic(kaddr, KM_USER0);
1991                 } */
1992                 /* If we are writing a full page it will be up to date,
1993                    no need to read from the server */
1994                 if ((to == PAGE_CACHE_SIZE) && (from == 0))
1995                         SetPageUptodate(page);
1996
1997                 /* might as well read a page, it is fast enough */
1998                 if ((file->f_flags & O_ACCMODE) != O_WRONLY) {
1999                         rc = cifs_readpage_worker(file, page, &offset);
2000                 } else {
2001                 /* should we try using another file handle if there is one -
2002                    how would we lock it to prevent close of that handle
2003                    racing with this read?
2004                    In any case this will be written out by commit_write */
2005                 }
2006         }
2007
2008         /* BB should we pass any errors back?
2009            e.g. if we do not have read access to the file */
2010         return 0;
2011 }
2012
2013 const struct address_space_operations cifs_addr_ops = {
2014         .readpage = cifs_readpage,
2015         .readpages = cifs_readpages,
2016         .writepage = cifs_writepage,
2017         .writepages = cifs_writepages,
2018         .prepare_write = cifs_prepare_write,
2019         .commit_write = cifs_commit_write,
2020         .set_page_dirty = __set_page_dirty_nobuffers,
2021         /* .sync_page = cifs_sync_page, */
2022         /* .direct_IO = */
2023 };
2024
2025 /*
2026  * cifs_readpages requires the server to support a buffer large enough to
2027  * contain the header plus one complete page of data.  Otherwise, we need
2028  * to leave cifs_readpages out of the address space operations.
2029  */
2030 const struct address_space_operations cifs_addr_ops_smallbuf = {
2031         .readpage = cifs_readpage,
2032         .writepage = cifs_writepage,
2033         .writepages = cifs_writepages,
2034         .prepare_write = cifs_prepare_write,
2035         .commit_write = cifs_commit_write,
2036         .set_page_dirty = __set_page_dirty_nobuffers,
2037         /* .sync_page = cifs_sync_page, */
2038         /* .direct_IO = */
2039 };