Pileus Git - ~andy/linux/blob - 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., 2002,2010
   7  *   Author(s): Steve French (sfrench@us.ibm.com)
   8  *              Jeremy Allison (jra@samba.org)
   9  *
  10  *   This library is free software; you can redistribute it and/or modify
  11  *   it under the terms of the GNU Lesser General Public License as published
  12  *   by the Free Software Foundation; either version 2.1 of the License, or
  13  *   (at your option) any later version.
  14  *
  15  *   This library is distributed in the hope that it will be useful,
  16  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  18  *   the GNU Lesser General Public License for more details.
  19  *
  20  *   You should have received a copy of the GNU Lesser General Public License
  21  *   along with this library; if not, write to the Free Software
  22  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  23  */
  24 #include <linux/fs.h>
  25 #include <linux/backing-dev.h>
  26 #include <linux/stat.h>
  27 #include <linux/fcntl.h>
  28 #include <linux/pagemap.h>
  29 #include <linux/pagevec.h>
  30 #include <linux/writeback.h>
  31 #include <linux/task_io_accounting_ops.h>
  32 #include <linux/delay.h>
  33 #include <linux/mount.h>
  34 #include <linux/slab.h>
  35 #include <asm/div64.h>
  36 #include "cifsfs.h"
  37 #include "cifspdu.h"
  38 #include "cifsglob.h"
  39 #include "cifsproto.h"
  40 #include "cifs_unicode.h"
  41 #include "cifs_debug.h"
  42 #include "cifs_fs_sb.h"
  43
  44 static inline int cifs_convert_flags(unsigned int flags)
  45 {
  46         if ((flags & O_ACCMODE) == O_RDONLY)
  47                 return GENERIC_READ;
  48         else if ((flags & O_ACCMODE) == O_WRONLY)
  49                 return GENERIC_WRITE;
  50         else if ((flags & O_ACCMODE) == O_RDWR) {
  51                 /* GENERIC_ALL is too much permission to request
  52                    can cause unnecessary access denied on create */
  53                 /* return GENERIC_ALL; */
  54                 return (GENERIC_READ | GENERIC_WRITE);
  55         }
  56
  57         return (READ_CONTROL | FILE_WRITE_ATTRIBUTES | FILE_READ_ATTRIBUTES |
  58                 FILE_WRITE_EA | FILE_APPEND_DATA | FILE_WRITE_DATA |
  59                 FILE_READ_DATA);
  60 }
  61
  62 static inline fmode_t cifs_posix_convert_flags(unsigned int flags)
  63 {
  64         fmode_t posix_flags = 0;
  65
  66         if ((flags & O_ACCMODE) == O_RDONLY)
  67                 posix_flags = FMODE_READ;
  68         else if ((flags & O_ACCMODE) == O_WRONLY)
  69                 posix_flags = FMODE_WRITE;
  70         else if ((flags & O_ACCMODE) == O_RDWR) {
  71                 /* GENERIC_ALL is too much permission to request
  72                    can cause unnecessary access denied on create */
  73                 /* return GENERIC_ALL; */
  74                 posix_flags = FMODE_READ | FMODE_WRITE;
  75         }
  76         /* can not map O_CREAT or O_EXCL or O_TRUNC flags when
  77            reopening a file.  They had their effect on the original open */
  78         if (flags & O_APPEND)
  79                 posix_flags |= (fmode_t)O_APPEND;
  80         if (flags & O_DSYNC)
  81                 posix_flags |= (fmode_t)O_DSYNC;
  82         if (flags & __O_SYNC)
  83                 posix_flags |= (fmode_t)__O_SYNC;
  84         if (flags & O_DIRECTORY)
  85                 posix_flags |= (fmode_t)O_DIRECTORY;
  86         if (flags & O_NOFOLLOW)
  87                 posix_flags |= (fmode_t)O_NOFOLLOW;
  88         if (flags & O_DIRECT)
  89                 posix_flags |= (fmode_t)O_DIRECT;
  90
  91         return posix_flags;
  92 }
  93
  94 static inline int cifs_get_disposition(unsigned int flags)
  95 {
  96         if ((flags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
  97                 return FILE_CREATE;
  98         else if ((flags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
  99                 return FILE_OVERWRITE_IF;
 100         else if ((flags & O_CREAT) == O_CREAT)
 101                 return FILE_OPEN_IF;
 102         else if ((flags & O_TRUNC) == O_TRUNC)
 103                 return FILE_OVERWRITE;
 104         else
 105                 return FILE_OPEN;
 106 }
 107
 108 /* all arguments to this function must be checked for validity in caller */
 109 static inline int
 110 cifs_posix_open_inode_helper(struct inode *inode, struct file *file,
 111                              struct cifsInodeInfo *pCifsInode, __u32 oplock,
 112                              u16 netfid)
 113 {
 114
 115         write_lock(&GlobalSMBSeslock);
 116
 117         pCifsInode = CIFS_I(file->f_path.dentry->d_inode);
 118         if (pCifsInode == NULL) {
 119                 write_unlock(&GlobalSMBSeslock);
 120                 return -EINVAL;
 121         }
 122
 123         if (pCifsInode->clientCanCacheRead) {
 124                 /* we have the inode open somewhere else
 125                    no need to discard cache data */
 126                 goto psx_client_can_cache;
 127         }
 128
 129         /* BB FIXME need to fix this check to move it earlier into posix_open
 130            BB  fIX following section BB FIXME */
 131
 132         /* if not oplocked, invalidate inode pages if mtime or file
 133            size changed */
 134 /*      temp = cifs_NTtimeToUnix(le64_to_cpu(buf->LastWriteTime));
 135         if (timespec_equal(&file->f_path.dentry->d_inode->i_mtime, &temp) &&
 136                            (file->f_path.dentry->d_inode->i_size ==
 137                             (loff_t)le64_to_cpu(buf->EndOfFile))) {
 138                 cFYI(1, "inode unchanged on server");
 139         } else {
 140                 if (file->f_path.dentry->d_inode->i_mapping) {
 141                         rc = filemap_write_and_wait(file->f_path.dentry->d_inode->i_mapping);
 142                         if (rc != 0)
 143                                 CIFS_I(file->f_path.dentry->d_inode)->write_behind_rc = rc;
 144                 }
 145                 cFYI(1, "invalidating remote inode since open detected it "
 146                          "changed");
 147                 invalidate_remote_inode(file->f_path.dentry->d_inode);
 148         } */
 149
 150 psx_client_can_cache:
 151         if ((oplock & 0xF) == OPLOCK_EXCLUSIVE) {
 152                 pCifsInode->clientCanCacheAll = true;
 153                 pCifsInode->clientCanCacheRead = true;
 154                 cFYI(1, "Exclusive Oplock granted on inode %p",
 155                          file->f_path.dentry->d_inode);
 156         } else if ((oplock & 0xF) == OPLOCK_READ)
 157                 pCifsInode->clientCanCacheRead = true;
 158
 159         /* will have to change the unlock if we reenable the
 160            filemap_fdatawrite (which does not seem necessary */
 161         write_unlock(&GlobalSMBSeslock);
 162         return 0;
 163 }
 164
 165 /* all arguments to this function must be checked for validity in caller */
 166 static inline int cifs_open_inode_helper(struct inode *inode,
 167         struct cifsTconInfo *pTcon, int *oplock, FILE_ALL_INFO *buf,
 168         char *full_path, int xid)
 169 {
 170         struct cifsInodeInfo *pCifsInode = CIFS_I(inode);
 171         struct timespec temp;
 172         int rc;
 173
 174         if (pCifsInode->clientCanCacheRead) {
 175                 /* we have the inode open somewhere else
 176                    no need to discard cache data */
 177                 goto client_can_cache;
 178         }
 179
 180         /* BB need same check in cifs_create too? */
 181         /* if not oplocked, invalidate inode pages if mtime or file
 182            size changed */
 183         temp = cifs_NTtimeToUnix(buf->LastWriteTime);
 184         if (timespec_equal(&inode->i_mtime, &temp) &&
 185                            (inode->i_size ==
 186                             (loff_t)le64_to_cpu(buf->EndOfFile))) {
 187                 cFYI(1, "inode unchanged on server");
 188         } else {
 189                 if (inode->i_mapping) {
 190                         /* BB no need to lock inode until after invalidate
 191                         since namei code should already have it locked? */
 192                         rc = filemap_write_and_wait(inode->i_mapping);
 193                         if (rc != 0)
 194                                 pCifsInode->write_behind_rc = rc;
 195                 }
 196                 cFYI(1, "invalidating remote inode since open detected it "
 197                          "changed");
 198                 invalidate_remote_inode(inode);
 199         }
 200
 201 client_can_cache:
 202         if (pTcon->unix_ext)
 203                 rc = cifs_get_inode_info_unix(&inode, full_path, inode->i_sb,
 204                                               xid);
 205         else
 206                 rc = cifs_get_inode_info(&inode, full_path, buf, inode->i_sb,
 207                                          xid, NULL);
 208
 209         if ((*oplock & 0xF) == OPLOCK_EXCLUSIVE) {
 210                 pCifsInode->clientCanCacheAll = true;
 211                 pCifsInode->clientCanCacheRead = true;
 212                 cFYI(1, "Exclusive Oplock granted on inode %p", inode);
 213         } else if ((*oplock & 0xF) == OPLOCK_READ)
 214                 pCifsInode->clientCanCacheRead = true;
 215
 216         return rc;
 217 }
 218
 219 int cifs_open(struct inode *inode, struct file *file)
 220 {
 221         int rc = -EACCES;
 222         int xid;
 223         __u32 oplock;
 224         struct cifs_sb_info *cifs_sb;
 225         struct cifsTconInfo *tcon;
 226         struct cifsFileInfo *pCifsFile = NULL;
 227         struct cifsInodeInfo *pCifsInode;
 228         char *full_path = NULL;
 229         int desiredAccess;
 230         int disposition;
 231         __u16 netfid;
 232         FILE_ALL_INFO *buf = NULL;
 233
 234         xid = GetXid();
 235
 236         cifs_sb = CIFS_SB(inode->i_sb);
 237         tcon = cifs_sb->tcon;
 238
 239         pCifsInode = CIFS_I(file->f_path.dentry->d_inode);
 240
 241         full_path = build_path_from_dentry(file->f_path.dentry);
 242         if (full_path == NULL) {
 243                 rc = -ENOMEM;
 244                 FreeXid(xid);
 245                 return rc;
 246         }
 247
 248         cFYI(1, "inode = 0x%p file flags are 0x%x for %s",
 249                  inode, file->f_flags, full_path);
 250
 251         if (oplockEnabled)
 252                 oplock = REQ_OPLOCK;
 253         else
 254                 oplock = 0;
 255
 256         if (!tcon->broken_posix_open && tcon->unix_ext &&
 257             (tcon->ses->capabilities & CAP_UNIX) &&
 258             (CIFS_UNIX_POSIX_PATH_OPS_CAP &
 259                         le64_to_cpu(tcon->fsUnixInfo.Capability))) {
 260                 int oflags = (int) cifs_posix_convert_flags(file->f_flags);
 261                 oflags |= SMB_O_CREAT;
 262                 /* can not refresh inode info since size could be stale */
 263                 rc = cifs_posix_open(full_path, &inode, inode->i_sb,
 264                                 cifs_sb->mnt_file_mode /* ignored */,
 265                                 oflags, &oplock, &netfid, xid);
 266                 if (rc == 0) {
 267                         cFYI(1, "posix open succeeded");
 268                         /* no need for special case handling of setting mode
 269                            on read only files needed here */
 270
 271                         pCifsFile = cifs_new_fileinfo(inode, netfid, file,
 272                                                         file->f_path.mnt,
 273                                                         oflags);
 274                         if (pCifsFile == NULL) {
 275                                 CIFSSMBClose(xid, tcon, netfid);
 276                                 rc = -ENOMEM;
 277                                 goto out;
 278                         }
 279
 280                         rc = cifs_posix_open_inode_helper(inode, file,
 281                                         pCifsInode, oplock, netfid);
 282                         goto out;
 283                 } else if ((rc == -EINVAL) || (rc == -EOPNOTSUPP)) {
 284                         if (tcon->ses->serverNOS)
 285                                 cERROR(1, "server %s of type %s returned"
 286                                            " unexpected error on SMB posix open"
 287                                            ", disabling posix open support."
 288                                            " Check if server update available.",
 289                                            tcon->ses->serverName,
 290                                            tcon->ses->serverNOS);
 291                         tcon->broken_posix_open = true;
 292                 } else if ((rc != -EIO) && (rc != -EREMOTE) &&
 293                          (rc != -EOPNOTSUPP)) /* path not found or net err */
 294                         goto out;
 295                 /* else fallthrough to retry open the old way on network i/o
 296                    or DFS errors */
 297         }
 298
 299         desiredAccess = cifs_convert_flags(file->f_flags);
 300
 301 /*********************************************************************
 302  *  open flag mapping table:
 303  *
 304  *      POSIX Flag            CIFS Disposition
 305  *      ----------            ----------------
 306  *      O_CREAT               FILE_OPEN_IF
 307  *      O_CREAT | O_EXCL      FILE_CREATE
 308  *      O_CREAT | O_TRUNC     FILE_OVERWRITE_IF
 309  *      O_TRUNC               FILE_OVERWRITE
 310  *      none of the above     FILE_OPEN
 311  *
 312  *      Note that there is not a direct match between disposition
 313  *      FILE_SUPERSEDE (ie create whether or not file exists although
 314  *      O_CREAT | O_TRUNC is similar but truncates the existing
 315  *      file rather than creating a new file as FILE_SUPERSEDE does
 316  *      (which uses the attributes / metadata passed in on open call)
 317  *?
 318  *?  O_SYNC is a reasonable match to CIFS writethrough flag
 319  *?  and the read write flags match reasonably.  O_LARGEFILE
 320  *?  is irrelevant because largefile support is always used
 321  *?  by this client. Flags O_APPEND, O_DIRECT, O_DIRECTORY,
 322  *       O_FASYNC, O_NOFOLLOW, O_NONBLOCK need further investigation
 323  *********************************************************************/
 324
 325         disposition = cifs_get_disposition(file->f_flags);
 326
 327         /* BB pass O_SYNC flag through on file attributes .. BB */
 328
 329         /* Also refresh inode by passing in file_info buf returned by SMBOpen
 330            and calling get_inode_info with returned buf (at least helps
 331            non-Unix server case) */
 332
 333         /* BB we can not do this if this is the second open of a file
 334            and the first handle has writebehind data, we might be
 335            able to simply do a filemap_fdatawrite/filemap_fdatawait first */
 336         buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
 337         if (!buf) {
 338                 rc = -ENOMEM;
 339                 goto out;
 340         }
 341
 342         if (cifs_sb->tcon->ses->capabilities & CAP_NT_SMBS)
 343                 rc = CIFSSMBOpen(xid, tcon, full_path, disposition,
 344                          desiredAccess, CREATE_NOT_DIR, &netfid, &oplock, buf,
 345                          cifs_sb->local_nls, cifs_sb->mnt_cifs_flags
 346                                  & CIFS_MOUNT_MAP_SPECIAL_CHR);
 347         else
 348                 rc = -EIO; /* no NT SMB support fall into legacy open below */
 349
 350         if (rc == -EIO) {
 351                 /* Old server, try legacy style OpenX */
 352                 rc = SMBLegacyOpen(xid, tcon, full_path, disposition,
 353                         desiredAccess, CREATE_NOT_DIR, &netfid, &oplock, buf,
 354                         cifs_sb->local_nls, cifs_sb->mnt_cifs_flags
 355                                 & CIFS_MOUNT_MAP_SPECIAL_CHR);
 356         }
 357         if (rc) {
 358                 cFYI(1, "cifs_open returned 0x%x", rc);
 359                 goto out;
 360         }
 361
 362         pCifsFile = cifs_new_fileinfo(inode, netfid, file, file->f_path.mnt,
 363                                         file->f_flags);
 364         if (pCifsFile == NULL) {
 365                 rc = -ENOMEM;
 366                 goto out;
 367         }
 368
 369         rc = cifs_open_inode_helper(inode, tcon, &oplock, buf, full_path, xid);
 370
 371         if (oplock & CIFS_CREATE_ACTION) {
 372                 /* time to set mode which we can not set earlier due to
 373                    problems creating new read-only files */
 374                 if (tcon->unix_ext) {
 375                         struct cifs_unix_set_info_args args = {
 376                                 .mode   = inode->i_mode,
 377                                 .uid    = NO_CHANGE_64,
 378                                 .gid    = NO_CHANGE_64,
 379                                 .ctime  = NO_CHANGE_64,
 380                                 .atime  = NO_CHANGE_64,
 381                                 .mtime  = NO_CHANGE_64,
 382                                 .device = 0,
 383                         };
 384                         CIFSSMBUnixSetPathInfo(xid, tcon, full_path, &args,
 385                                                cifs_sb->local_nls,
 386                                                cifs_sb->mnt_cifs_flags &
 387                                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
 388                 }
 389         }
 390
 391 out:
 392         kfree(buf);
 393         kfree(full_path);
 394         FreeXid(xid);
 395         return rc;
 396 }
 397
 398 /* Try to reacquire byte range locks that were released when session */
 399 /* to server was lost */
 400 static int cifs_relock_file(struct cifsFileInfo *cifsFile)
 401 {
 402         int rc = 0;
 403
 404 /* BB list all locks open on this file and relock */
 405
 406         return rc;
 407 }
 408
 409 static int cifs_reopen_file(struct file *file, bool can_flush)
 410 {
 411         int rc = -EACCES;
 412         int xid;
 413         __u32 oplock;
 414         struct cifs_sb_info *cifs_sb;
 415         struct cifsTconInfo *tcon;
 416         struct cifsFileInfo *pCifsFile;
 417         struct cifsInodeInfo *pCifsInode;
 418         struct inode *inode;
 419         char *full_path = NULL;
 420         int desiredAccess;
 421         int disposition = FILE_OPEN;
 422         __u16 netfid;
 423
 424         if (file->private_data)
 425                 pCifsFile = (struct cifsFileInfo *)file->private_data;
 426         else
 427                 return -EBADF;
 428
 429         xid = GetXid();
 430         mutex_lock(&pCifsFile->fh_mutex);
 431         if (!pCifsFile->invalidHandle) {
 432                 mutex_unlock(&pCifsFile->fh_mutex);
 433                 rc = 0;
 434                 FreeXid(xid);
 435                 return rc;
 436         }
 437
 438         if (file->f_path.dentry == NULL) {
 439                 cERROR(1, "no valid name if dentry freed");
 440                 dump_stack();
 441                 rc = -EBADF;
 442                 goto reopen_error_exit;
 443         }
 444
 445         inode = file->f_path.dentry->d_inode;
 446         if (inode == NULL) {
 447                 cERROR(1, "inode not valid");
 448                 dump_stack();
 449                 rc = -EBADF;
 450                 goto reopen_error_exit;
 451         }
 452
 453         cifs_sb = CIFS_SB(inode->i_sb);
 454         tcon = cifs_sb->tcon;
 455
 456 /* can not grab rename sem here because various ops, including
 457    those that already have the rename sem can end up causing writepage
 458    to get called and if the server was down that means we end up here,
 459    and we can never tell if the caller already has the rename_sem */
 460         full_path = build_path_from_dentry(file->f_path.dentry);
 461         if (full_path == NULL) {
 462                 rc = -ENOMEM;
 463 reopen_error_exit:
 464                 mutex_unlock(&pCifsFile->fh_mutex);
 465                 FreeXid(xid);
 466                 return rc;
 467         }
 468
 469         cFYI(1, "inode = 0x%p file flags 0x%x for %s",
 470                  inode, file->f_flags, full_path);
 471
 472         if (oplockEnabled)
 473                 oplock = REQ_OPLOCK;
 474         else
 475                 oplock = 0;
 476
 477         if (tcon->unix_ext && (tcon->ses->capabilities & CAP_UNIX) &&
 478             (CIFS_UNIX_POSIX_PATH_OPS_CAP &
 479                         le64_to_cpu(tcon->fsUnixInfo.Capability))) {
 480                 int oflags = (int) cifs_posix_convert_flags(file->f_flags);
 481                 /* can not refresh inode info since size could be stale */
 482                 rc = cifs_posix_open(full_path, NULL, inode->i_sb,
 483                                 cifs_sb->mnt_file_mode /* ignored */,
 484                                 oflags, &oplock, &netfid, xid);
 485                 if (rc == 0) {
 486                         cFYI(1, "posix reopen succeeded");
 487                         goto reopen_success;
 488                 }
 489                 /* fallthrough to retry open the old way on errors, especially
 490                    in the reconnect path it is important to retry hard */
 491         }
 492
 493         desiredAccess = cifs_convert_flags(file->f_flags);
 494
 495         /* Can not refresh inode by passing in file_info buf to be returned
 496            by SMBOpen and then calling get_inode_info with returned buf
 497            since file might have write behind data that needs to be flushed
 498            and server version of file size can be stale. If we knew for sure
 499            that inode was not dirty locally we could do this */
 500
 501         rc = CIFSSMBOpen(xid, tcon, full_path, disposition, desiredAccess,
 502                          CREATE_NOT_DIR, &netfid, &oplock, NULL,
 503                          cifs_sb->local_nls, cifs_sb->mnt_cifs_flags &
 504                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
 505         if (rc) {
 506                 mutex_unlock(&pCifsFile->fh_mutex);
 507                 cFYI(1, "cifs_open returned 0x%x", rc);
 508                 cFYI(1, "oplock: %d", oplock);
 509         } else {
 510 reopen_success:
 511                 pCifsFile->netfid = netfid;
 512                 pCifsFile->invalidHandle = false;
 513                 mutex_unlock(&pCifsFile->fh_mutex);
 514                 pCifsInode = CIFS_I(inode);
 515                 if (pCifsInode) {
 516                         if (can_flush) {
 517                                 rc = filemap_write_and_wait(inode->i_mapping);
 518                                 if (rc != 0)
 519                                         CIFS_I(inode)->write_behind_rc = rc;
 520                         /* temporarily disable caching while we
 521                            go to server to get inode info */
 522                                 pCifsInode->clientCanCacheAll = false;
 523                                 pCifsInode->clientCanCacheRead = false;
 524                                 if (tcon->unix_ext)
 525                                         rc = cifs_get_inode_info_unix(&inode,
 526                                                 full_path, inode->i_sb, xid);
 527                                 else
 528                                         rc = cifs_get_inode_info(&inode,
 529                                                 full_path, NULL, inode->i_sb,
 530                                                 xid, NULL);
 531                         } /* else we are writing out data to server already
 532                              and could deadlock if we tried to flush data, and
 533                              since we do not know if we have data that would
 534                              invalidate the current end of file on the server
 535                              we can not go to the server to get the new inod
 536                              info */
 537                         if ((oplock & 0xF) == OPLOCK_EXCLUSIVE) {
 538                                 pCifsInode->clientCanCacheAll = true;
 539                                 pCifsInode->clientCanCacheRead = true;
 540                                 cFYI(1, "Exclusive Oplock granted on inode %p",
 541                                          file->f_path.dentry->d_inode);
 542                         } else if ((oplock & 0xF) == OPLOCK_READ) {
 543                                 pCifsInode->clientCanCacheRead = true;
 544                                 pCifsInode->clientCanCacheAll = false;
 545                         } else {
 546                                 pCifsInode->clientCanCacheRead = false;
 547                                 pCifsInode->clientCanCacheAll = false;
 548                         }
 549                         cifs_relock_file(pCifsFile);
 550                 }
 551         }
 552         kfree(full_path);
 553         FreeXid(xid);
 554         return rc;
 555 }
 556
 557 int cifs_close(struct inode *inode, struct file *file)
 558 {
 559         int rc = 0;
 560         int xid, timeout;
 561         struct cifs_sb_info *cifs_sb;
 562         struct cifsTconInfo *pTcon;
 563         struct cifsFileInfo *pSMBFile =
 564                 (struct cifsFileInfo *)file->private_data;
 565
 566         xid = GetXid();
 567
 568         cifs_sb = CIFS_SB(inode->i_sb);
 569         pTcon = cifs_sb->tcon;
 570         if (pSMBFile) {
 571                 struct cifsLockInfo *li, *tmp;
 572                 write_lock(&GlobalSMBSeslock);
 573                 pSMBFile->closePend = true;
 574                 if (pTcon) {
 575                         /* no sense reconnecting to close a file that is
 576                            already closed */
 577                         if (!pTcon->need_reconnect) {
 578                                 write_unlock(&GlobalSMBSeslock);
 579                                 timeout = 2;
 580                                 while ((atomic_read(&pSMBFile->count) != 1)
 581                                         && (timeout <= 2048)) {
 582                                         /* Give write a better chance to get to
 583                                         server ahead of the close.  We do not
 584                                         want to add a wait_q here as it would
 585                                         increase the memory utilization as
 586                                         the struct would be in each open file,
 587                                         but this should give enough time to
 588                                         clear the socket */
 589                                         cFYI(DBG2, "close delay, write pending");
 590                                         msleep(timeout);
 591                                         timeout *= 4;
 592                                 }
 593                                 if (!pTcon->need_reconnect &&
 594                                     !pSMBFile->invalidHandle)
 595                                         rc = CIFSSMBClose(xid, pTcon,
 596                                                   pSMBFile->netfid);
 597                         } else
 598                                 write_unlock(&GlobalSMBSeslock);
 599                 } else
 600                         write_unlock(&GlobalSMBSeslock);
 601
 602                 /* Delete any outstanding lock records.
 603                    We'll lose them when the file is closed anyway. */
 604                 mutex_lock(&pSMBFile->lock_mutex);
 605                 list_for_each_entry_safe(li, tmp, &pSMBFile->llist, llist) {
 606                         list_del(&li->llist);
 607                         kfree(li);
 608                 }
 609                 mutex_unlock(&pSMBFile->lock_mutex);
 610
 611                 write_lock(&GlobalSMBSeslock);
 612                 list_del(&pSMBFile->flist);
 613                 list_del(&pSMBFile->tlist);
 614                 write_unlock(&GlobalSMBSeslock);
 615                 cifsFileInfo_put(file->private_data);
 616                 file->private_data = NULL;
 617         } else
 618                 rc = -EBADF;
 619
 620         read_lock(&GlobalSMBSeslock);
 621         if (list_empty(&(CIFS_I(inode)->openFileList))) {
 622                 cFYI(1, "closing last open instance for inode %p", inode);
 623                 /* if the file is not open we do not know if we can cache info
 624                    on this inode, much less write behind and read ahead */
 625                 CIFS_I(inode)->clientCanCacheRead = false;
 626                 CIFS_I(inode)->clientCanCacheAll  = false;
 627         }
 628         read_unlock(&GlobalSMBSeslock);
 629         if ((rc == 0) && CIFS_I(inode)->write_behind_rc)
 630                 rc = CIFS_I(inode)->write_behind_rc;
 631         FreeXid(xid);
 632         return rc;
 633 }
 634
 635 int cifs_closedir(struct inode *inode, struct file *file)
 636 {
 637         int rc = 0;
 638         int xid;
 639         struct cifsFileInfo *pCFileStruct =
 640             (struct cifsFileInfo *)file->private_data;
 641         char *ptmp;
 642
 643         cFYI(1, "Closedir inode = 0x%p", inode);
 644
 645         xid = GetXid();
 646
 647         if (pCFileStruct) {
 648                 struct cifsTconInfo *pTcon;
 649                 struct cifs_sb_info *cifs_sb =
 650                         CIFS_SB(file->f_path.dentry->d_sb);
 651
 652                 pTcon = cifs_sb->tcon;
 653
 654                 cFYI(1, "Freeing private data in close dir");
 655                 write_lock(&GlobalSMBSeslock);
 656                 if (!pCFileStruct->srch_inf.endOfSearch &&
 657                     !pCFileStruct->invalidHandle) {
 658                         pCFileStruct->invalidHandle = true;
 659                         write_unlock(&GlobalSMBSeslock);
 660                         rc = CIFSFindClose(xid, pTcon, pCFileStruct->netfid);
 661                         cFYI(1, "Closing uncompleted readdir with rc %d",
 662                                  rc);
 663                         /* not much we can do if it fails anyway, ignore rc */
 664                         rc = 0;
 665                 } else
 666                         write_unlock(&GlobalSMBSeslock);
 667                 ptmp = pCFileStruct->srch_inf.ntwrk_buf_start;
 668                 if (ptmp) {
 669                         cFYI(1, "closedir free smb buf in srch struct");
 670                         pCFileStruct->srch_inf.ntwrk_buf_start = NULL;
 671                         if (pCFileStruct->srch_inf.smallBuf)
 672                                 cifs_small_buf_release(ptmp);
 673                         else
 674                                 cifs_buf_release(ptmp);
 675                 }
 676                 kfree(file->private_data);
 677                 file->private_data = NULL;
 678         }
 679         /* BB can we lock the filestruct while this is going on? */
 680         FreeXid(xid);
 681         return rc;
 682 }
 683
 684 static int store_file_lock(struct cifsFileInfo *fid, __u64 len,
 685                                 __u64 offset, __u8 lockType)
 686 {
 687         struct cifsLockInfo *li =
 688                 kmalloc(sizeof(struct cifsLockInfo), GFP_KERNEL);
 689         if (li == NULL)
 690                 return -ENOMEM;
 691         li->offset = offset;
 692         li->length = len;
 693         li->type = lockType;
 694         mutex_lock(&fid->lock_mutex);
 695         list_add(&li->llist, &fid->llist);
 696         mutex_unlock(&fid->lock_mutex);
 697         return 0;
 698 }
 699
 700 int cifs_lock(struct file *file, int cmd, struct file_lock *pfLock)
 701 {
 702         int rc, xid;
 703         __u32 numLock = 0;
 704         __u32 numUnlock = 0;
 705         __u64 length;
 706         bool wait_flag = false;
 707         struct cifs_sb_info *cifs_sb;
 708         struct cifsTconInfo *tcon;
 709         __u16 netfid;
 710         __u8 lockType = LOCKING_ANDX_LARGE_FILES;
 711         bool posix_locking = 0;
 712
 713         length = 1 + pfLock->fl_end - pfLock->fl_start;
 714         rc = -EACCES;
 715         xid = GetXid();
 716
 717         cFYI(1, "Lock parm: 0x%x flockflags: "
 718                  "0x%x flocktype: 0x%x start: %lld end: %lld",
 719                 cmd, pfLock->fl_flags, pfLock->fl_type, pfLock->fl_start,
 720                 pfLock->fl_end);
 721
 722         if (pfLock->fl_flags & FL_POSIX)
 723                 cFYI(1, "Posix");
 724         if (pfLock->fl_flags & FL_FLOCK)
 725                 cFYI(1, "Flock");
 726         if (pfLock->fl_flags & FL_SLEEP) {
 727                 cFYI(1, "Blocking lock");
 728                 wait_flag = true;
 729         }
 730         if (pfLock->fl_flags & FL_ACCESS)
 731                 cFYI(1, "Process suspended by mandatory locking - "
 732                          "not implemented yet");
 733         if (pfLock->fl_flags & FL_LEASE)
 734                 cFYI(1, "Lease on file - not implemented yet");
 735         if (pfLock->fl_flags &
 736             (~(FL_POSIX | FL_FLOCK | FL_SLEEP | FL_ACCESS | FL_LEASE)))
 737                 cFYI(1, "Unknown lock flags 0x%x", pfLock->fl_flags);
 738
 739         if (pfLock->fl_type == F_WRLCK) {
 740                 cFYI(1, "F_WRLCK ");
 741                 numLock = 1;
 742         } else if (pfLock->fl_type == F_UNLCK) {
 743                 cFYI(1, "F_UNLCK");
 744                 numUnlock = 1;
 745                 /* Check if unlock includes more than
 746                 one lock range */
 747         } else if (pfLock->fl_type == F_RDLCK) {
 748                 cFYI(1, "F_RDLCK");
 749                 lockType |= LOCKING_ANDX_SHARED_LOCK;
 750                 numLock = 1;
 751         } else if (pfLock->fl_type == F_EXLCK) {
 752                 cFYI(1, "F_EXLCK");
 753                 numLock = 1;
 754         } else if (pfLock->fl_type == F_SHLCK) {
 755                 cFYI(1, "F_SHLCK");
 756                 lockType |= LOCKING_ANDX_SHARED_LOCK;
 757                 numLock = 1;
 758         } else
 759                 cFYI(1, "Unknown type of lock");
 760
 761         cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
 762         tcon = cifs_sb->tcon;
 763
 764         if (file->private_data == NULL) {
 765                 rc = -EBADF;
 766                 FreeXid(xid);
 767                 return rc;
 768         }
 769         netfid = ((struct cifsFileInfo *)file->private_data)->netfid;
 770
 771         if ((tcon->ses->capabilities & CAP_UNIX) &&
 772             (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
 773             ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
 774                 posix_locking = 1;
 775         /* BB add code here to normalize offset and length to
 776         account for negative length which we can not accept over the
 777         wire */
 778         if (IS_GETLK(cmd)) {
 779                 if (posix_locking) {
 780                         int posix_lock_type;
 781                         if (lockType & LOCKING_ANDX_SHARED_LOCK)
 782                                 posix_lock_type = CIFS_RDLCK;
 783                         else
 784                                 posix_lock_type = CIFS_WRLCK;
 785                         rc = CIFSSMBPosixLock(xid, tcon, netfid, 1 /* get */,
 786                                         length, pfLock,
 787                                         posix_lock_type, wait_flag);
 788                         FreeXid(xid);
 789                         return rc;
 790                 }
 791
 792                 /* BB we could chain these into one lock request BB */
 793                 rc = CIFSSMBLock(xid, tcon, netfid, length, pfLock->fl_start,
 794                                  0, 1, lockType, 0 /* wait flag */ );
 795                 if (rc == 0) {
 796                         rc = CIFSSMBLock(xid, tcon, netfid, length,
 797                                          pfLock->fl_start, 1 /* numUnlock */ ,
 798                                          0 /* numLock */ , lockType,
 799                                          0 /* wait flag */ );
 800                         pfLock->fl_type = F_UNLCK;
 801                         if (rc != 0)
 802                                 cERROR(1, "Error unlocking previously locked "
 803                                            "range %d during test of lock", rc);
 804                         rc = 0;
 805
 806                 } else {
 807                         /* if rc == ERR_SHARING_VIOLATION ? */
 808                         rc = 0;
 809
 810                         if (lockType & LOCKING_ANDX_SHARED_LOCK) {
 811                                 pfLock->fl_type = F_WRLCK;
 812                         } else {
 813                                 rc = CIFSSMBLock(xid, tcon, netfid, length,
 814                                         pfLock->fl_start, 0, 1,
 815                                         lockType | LOCKING_ANDX_SHARED_LOCK,
 816                                         0 /* wait flag */);
 817                                 if (rc == 0) {
 818                                         rc = CIFSSMBLock(xid, tcon, netfid,
 819                                                 length, pfLock->fl_start, 1, 0,
 820                                                 lockType |
 821                                                 LOCKING_ANDX_SHARED_LOCK,
 822                                                 0 /* wait flag */);
 823                                         pfLock->fl_type = F_RDLCK;
 824                                         if (rc != 0)
 825                                                 cERROR(1, "Error unlocking "
 826                                                 "previously locked range %d "
 827                                                 "during test of lock", rc);
 828                                         rc = 0;
 829                                 } else {
 830                                         pfLock->fl_type = F_WRLCK;
 831                                         rc = 0;
 832                                 }
 833                         }
 834                 }
 835
 836                 FreeXid(xid);
 837                 return rc;
 838         }
 839
 840         if (!numLock && !numUnlock) {
 841                 /* if no lock or unlock then nothing
 842                 to do since we do not know what it is */
 843                 FreeXid(xid);
 844                 return -EOPNOTSUPP;
 845         }
 846
 847         if (posix_locking) {
 848                 int posix_lock_type;
 849                 if (lockType & LOCKING_ANDX_SHARED_LOCK)
 850                         posix_lock_type = CIFS_RDLCK;
 851                 else
 852                         posix_lock_type = CIFS_WRLCK;
 853
 854                 if (numUnlock == 1)
 855                         posix_lock_type = CIFS_UNLCK;
 856
 857                 rc = CIFSSMBPosixLock(xid, tcon, netfid, 0 /* set */,
 858                                       length, pfLock,
 859                                       posix_lock_type, wait_flag);
 860         } else {
 861                 struct cifsFileInfo *fid =
 862                         (struct cifsFileInfo *)file->private_data;
 863
 864                 if (numLock) {
 865                         rc = CIFSSMBLock(xid, tcon, netfid, length,
 866                                         pfLock->fl_start,
 867                                         0, numLock, lockType, wait_flag);
 868
 869                         if (rc == 0) {
 870                                 /* For Windows locks we must store them. */
 871                                 rc = store_file_lock(fid, length,
 872                                                 pfLock->fl_start, lockType);
 873                         }
 874                 } else if (numUnlock) {
 875                         /* For each stored lock that this unlock overlaps
 876                            completely, unlock it. */
 877                         int stored_rc = 0;
 878                         struct cifsLockInfo *li, *tmp;
 879
 880                         rc = 0;
 881                         mutex_lock(&fid->lock_mutex);
 882                         list_for_each_entry_safe(li, tmp, &fid->llist, llist) {
 883                                 if (pfLock->fl_start <= li->offset &&
 884                                                 (pfLock->fl_start + length) >=
 885                                                 (li->offset + li->length)) {
 886                                         stored_rc = CIFSSMBLock(xid, tcon,
 887                                                         netfid,
 888                                                         li->length, li->offset,
 889                                                         1, 0, li->type, false);
 890                                         if (stored_rc)
 891                                                 rc = stored_rc;
 892                                         else {
 893                                                 list_del(&li->llist);
 894                                                 kfree(li);
 895                                         }
 896                                 }
 897                         }
 898                         mutex_unlock(&fid->lock_mutex);
 899                 }
 900         }
 901
 902         if (pfLock->fl_flags & FL_POSIX)
 903                 posix_lock_file_wait(file, pfLock);
 904         FreeXid(xid);
 905         return rc;
 906 }
 907
 908 /*
 909  * Set the timeout on write requests past EOF. For some servers (Windows)
 910  * these calls can be very long.
 911  *
 912  * If we're writing >10M past the EOF we give a 180s timeout. Anything less
 913  * than that gets a 45s timeout. Writes not past EOF get 15s timeouts.
 914  * The 10M cutoff is totally arbitrary. A better scheme for this would be
 915  * welcome if someone wants to suggest one.
 916  *
 917  * We may be able to do a better job with this if there were some way to
 918  * declare that a file should be sparse.
 919  */
 920 static int
 921 cifs_write_timeout(struct cifsInodeInfo *cifsi, loff_t offset)
 922 {
 923         if (offset <= cifsi->server_eof)
 924                 return CIFS_STD_OP;
 925         else if (offset > (cifsi->server_eof + (10 * 1024 * 1024)))
 926                 return CIFS_VLONG_OP;
 927         else
 928                 return CIFS_LONG_OP;
 929 }
 930
 931 /* update the file size (if needed) after a write */
 932 static void
 933 cifs_update_eof(struct cifsInodeInfo *cifsi, loff_t offset,
 934                       unsigned int bytes_written)
 935 {
 936         loff_t end_of_write = offset + bytes_written;
 937
 938         if (end_of_write > cifsi->server_eof)
 939                 cifsi->server_eof = end_of_write;
 940 }
 941
 942 ssize_t cifs_user_write(struct file *file, const char __user *write_data,
 943         size_t write_size, loff_t *poffset)
 944 {
 945         int rc = 0;
 946         unsigned int bytes_written = 0;
 947         unsigned int total_written;
 948         struct cifs_sb_info *cifs_sb;
 949         struct cifsTconInfo *pTcon;
 950         int xid, long_op;
 951         struct cifsFileInfo *open_file;
 952         struct cifsInodeInfo *cifsi = CIFS_I(file->f_path.dentry->d_inode);
 953
 954         cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
 955
 956         pTcon = cifs_sb->tcon;
 957
 958         /* cFYI(1, " write %d bytes to offset %lld of %s", write_size,
 959            *poffset, file->f_path.dentry->d_name.name); */
 960
 961         if (file->private_data == NULL)
 962                 return -EBADF;
 963         open_file = (struct cifsFileInfo *) file->private_data;
 964
 965         rc = generic_write_checks(file, poffset, &write_size, 0);
 966         if (rc)
 967                 return rc;
 968
 969         xid = GetXid();
 970
 971         long_op = cifs_write_timeout(cifsi, *poffset);
 972         for (total_written = 0; write_size > total_written;
 973              total_written += bytes_written) {
 974                 rc = -EAGAIN;
 975                 while (rc == -EAGAIN) {
 976                         if (file->private_data == NULL) {
 977                                 /* file has been closed on us */
 978                                 FreeXid(xid);
 979                         /* if we have gotten here we have written some data
 980                            and blocked, and the file has been freed on us while
 981                            we blocked so return what we managed to write */
 982                                 return total_written;
 983                         }
 984                         if (open_file->closePend) {
 985                                 FreeXid(xid);
 986                                 if (total_written)
 987                                         return total_written;
 988                                 else
 989                                         return -EBADF;
 990                         }
 991                         if (open_file->invalidHandle) {
 992                                 /* we could deadlock if we called
 993                                    filemap_fdatawait from here so tell
 994                                    reopen_file not to flush data to server
 995                                    now */
 996                                 rc = cifs_reopen_file(file, false);
 997                                 if (rc != 0)
 998                                         break;
 999                         }
1000
1001                         rc = CIFSSMBWrite(xid, pTcon,
1002                                 open_file->netfid,
1003                                 min_t(const int, cifs_sb->wsize,
1004                                       write_size - total_written),
1005                                 *poffset, &bytes_written,
1006                                 NULL, write_data + total_written, long_op);
1007                 }
1008                 if (rc || (bytes_written == 0)) {
1009                         if (total_written)
1010                                 break;
1011                         else {
1012                                 FreeXid(xid);
1013                                 return rc;
1014                         }
1015                 } else {
1016                         cifs_update_eof(cifsi, *poffset, bytes_written);
1017                         *poffset += bytes_written;
1018                 }
1019                 long_op = CIFS_STD_OP; /* subsequent writes fast -
1020                                     15 seconds is plenty */
1021         }
1022
1023         cifs_stats_bytes_written(pTcon, total_written);
1024
1025         /* since the write may have blocked check these pointers again */
1026         if ((file->f_path.dentry) && (file->f_path.dentry->d_inode)) {
1027                 struct inode *inode = file->f_path.dentry->d_inode;
1028 /* Do not update local mtime - server will set its actual value on write
1029  *              inode->i_ctime = inode->i_mtime =
1030  *                      current_fs_time(inode->i_sb);*/
1031                 if (total_written > 0) {
1032                         spin_lock(&inode->i_lock);
1033                         if (*poffset > file->f_path.dentry->d_inode->i_size)
1034                                 i_size_write(file->f_path.dentry->d_inode,
1035                                         *poffset);
1036                         spin_unlock(&inode->i_lock);
1037                 }
1038                 mark_inode_dirty_sync(file->f_path.dentry->d_inode);
1039         }
1040         FreeXid(xid);
1041         return total_written;
1042 }
1043
1044 static ssize_t cifs_write(struct file *file, const char *write_data,
1045                           size_t write_size, loff_t *poffset)
1046 {
1047         int rc = 0;
1048         unsigned int bytes_written = 0;
1049         unsigned int total_written;
1050         struct cifs_sb_info *cifs_sb;
1051         struct cifsTconInfo *pTcon;
1052         int xid, long_op;
1053         struct cifsFileInfo *open_file;
1054         struct cifsInodeInfo *cifsi = CIFS_I(file->f_path.dentry->d_inode);
1055
1056         cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
1057
1058         pTcon = cifs_sb->tcon;
1059
1060         cFYI(1, "write %zd bytes to offset %lld of %s", write_size,
1061            *poffset, file->f_path.dentry->d_name.name);
1062
1063         if (file->private_data == NULL)
1064                 return -EBADF;
1065         open_file = (struct cifsFileInfo *)file->private_data;
1066
1067         xid = GetXid();
1068
1069         long_op = cifs_write_timeout(cifsi, *poffset);
1070         for (total_written = 0; write_size > total_written;
1071              total_written += bytes_written) {
1072                 rc = -EAGAIN;
1073                 while (rc == -EAGAIN) {
1074                         if (file->private_data == NULL) {
1075                                 /* file has been closed on us */
1076                                 FreeXid(xid);
1077                         /* if we have gotten here we have written some data
1078                            and blocked, and the file has been freed on us
1079                            while we blocked so return what we managed to
1080                            write */
1081                                 return total_written;
1082                         }
1083                         if (open_file->closePend) {
1084                                 FreeXid(xid);
1085                                 if (total_written)
1086                                         return total_written;
1087                                 else
1088                                         return -EBADF;
1089                         }
1090                         if (open_file->invalidHandle) {
1091                                 /* we could deadlock if we called
1092                                    filemap_fdatawait from here so tell
1093                                    reopen_file not to flush data to
1094                                    server now */
1095                                 rc = cifs_reopen_file(file, false);
1096                                 if (rc != 0)
1097                                         break;
1098                         }
1099                         if (experimEnabled || (pTcon->ses->server &&
1100                                 ((pTcon->ses->server->secMode &
1101                                 (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED))
1102                                 == 0))) {
1103                                 struct kvec iov[2];
1104                                 unsigned int len;
1105
1106                                 len = min((size_t)cifs_sb->wsize,
1107                                           write_size - total_written);
1108                                 /* iov[0] is reserved for smb header */
1109                                 iov[1].iov_base = (char *)write_data +
1110                                                   total_written;
1111                                 iov[1].iov_len = len;
1112                                 rc = CIFSSMBWrite2(xid, pTcon,
1113                                                 open_file->netfid, len,
1114                                                 *poffset, &bytes_written,
1115                                                 iov, 1, long_op);
1116                         } else
1117                                 rc = CIFSSMBWrite(xid, pTcon,
1118                                          open_file->netfid,
1119                                          min_t(const int, cifs_sb->wsize,
1120                                                write_size - total_written),
1121                                          *poffset, &bytes_written,
1122                                          write_data + total_written,
1123                                          NULL, long_op);
1124                 }
1125                 if (rc || (bytes_written == 0)) {
1126                         if (total_written)
1127                                 break;
1128                         else {
1129                                 FreeXid(xid);
1130                                 return rc;
1131                         }
1132                 } else {
1133                         cifs_update_eof(cifsi, *poffset, bytes_written);
1134                         *poffset += bytes_written;
1135                 }
1136                 long_op = CIFS_STD_OP; /* subsequent writes fast -
1137                                     15 seconds is plenty */
1138         }
1139
1140         cifs_stats_bytes_written(pTcon, total_written);
1141
1142         /* since the write may have blocked check these pointers again */
1143         if ((file->f_path.dentry) && (file->f_path.dentry->d_inode)) {
1144 /*BB We could make this contingent on superblock ATIME flag too */
1145 /*              file->f_path.dentry->d_inode->i_ctime =
1146                 file->f_path.dentry->d_inode->i_mtime = CURRENT_TIME;*/
1147                 if (total_written > 0) {
1148                         spin_lock(&file->f_path.dentry->d_inode->i_lock);
1149                         if (*poffset > file->f_path.dentry->d_inode->i_size)
1150                                 i_size_write(file->f_path.dentry->d_inode,
1151                                              *poffset);
1152                         spin_unlock(&file->f_path.dentry->d_inode->i_lock);
1153                 }
1154                 mark_inode_dirty_sync(file->f_path.dentry->d_inode);
1155         }
1156         FreeXid(xid);
1157         return total_written;
1158 }
1159
1160 #ifdef CONFIG_CIFS_EXPERIMENTAL
1161 struct cifsFileInfo *find_readable_file(struct cifsInodeInfo *cifs_inode)
1162 {
1163         struct cifsFileInfo *open_file = NULL;
1164
1165         read_lock(&GlobalSMBSeslock);
1166         /* we could simply get the first_list_entry since write-only entries
1167            are always at the end of the list but since the first entry might
1168            have a close pending, we go through the whole list */
1169         list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
1170                 if (open_file->closePend)
1171                         continue;
1172                 if (open_file->pfile && ((open_file->pfile->f_flags & O_RDWR) ||
1173                     (open_file->pfile->f_flags & O_RDONLY))) {
1174                         if (!open_file->invalidHandle) {
1175                                 /* found a good file */
1176                                 /* lock it so it will not be closed on us */
1177                                 cifsFileInfo_get(open_file);
1178                                 read_unlock(&GlobalSMBSeslock);
1179                                 return open_file;
1180                         } /* else might as well continue, and look for
1181                              another, or simply have the caller reopen it
1182                              again rather than trying to fix this handle */
1183                 } else /* write only file */
1184                         break; /* write only files are last so must be done */
1185         }
1186         read_unlock(&GlobalSMBSeslock);
1187         return NULL;
1188 }
1189 #endif
1190
1191 struct cifsFileInfo *find_writable_file(struct cifsInodeInfo *cifs_inode)
1192 {
1193         struct cifsFileInfo *open_file;
1194         bool any_available = false;
1195         int rc;
1196
1197         /* Having a null inode here (because mapping->host was set to zero by
1198         the VFS or MM) should not happen but we had reports of on oops (due to
1199         it being zero) during stress testcases so we need to check for it */
1200
1201         if (cifs_inode == NULL) {
1202                 cERROR(1, "Null inode passed to cifs_writeable_file");
1203                 dump_stack();
1204                 return NULL;
1205         }
1206
1207         read_lock(&GlobalSMBSeslock);
1208 refind_writable:
1209         list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
1210                 if (open_file->closePend ||
1211                     (!any_available && open_file->pid != current->tgid))
1212                         continue;
1213
1214                 if (open_file->pfile &&
1215                     ((open_file->pfile->f_flags & O_RDWR) ||
1216                      (open_file->pfile->f_flags & O_WRONLY))) {
1217                         cifsFileInfo_get(open_file);
1218
1219                         if (!open_file->invalidHandle) {
1220                                 /* found a good writable file */
1221                                 read_unlock(&GlobalSMBSeslock);
1222                                 return open_file;
1223                         }
1224
1225                         read_unlock(&GlobalSMBSeslock);
1226                         /* Had to unlock since following call can block */
1227                         rc = cifs_reopen_file(open_file->pfile, false);
1228                         if (!rc) {
1229                                 if (!open_file->closePend)
1230                                         return open_file;
1231                                 else { /* start over in case this was deleted */
1232                                        /* since the list could be modified */
1233                                         read_lock(&GlobalSMBSeslock);
1234                                         cifsFileInfo_put(open_file);
1235                                         goto refind_writable;
1236                                 }
1237                         }
1238
1239                         /* if it fails, try another handle if possible -
1240                         (we can not do this if closePending since
1241                         loop could be modified - in which case we
1242                         have to start at the beginning of the list
1243                         again. Note that it would be bad
1244                         to hold up writepages here (rather than
1245                         in caller) with continuous retries */
1246                         cFYI(1, "wp failed on reopen file");
1247                         read_lock(&GlobalSMBSeslock);
1248                         /* can not use this handle, no write
1249                            pending on this one after all */
1250                         cifsFileInfo_put(open_file);
1251
1252                         if (open_file->closePend) /* list could have changed */
1253                                 goto refind_writable;
1254                         /* else we simply continue to the next entry. Thus
1255                            we do not loop on reopen errors.  If we
1256                            can not reopen the file, for example if we
1257                            reconnected to a server with another client
1258                            racing to delete or lock the file we would not
1259                            make progress if we restarted before the beginning
1260                            of the loop here. */
1261                 }
1262         }
1263         /* couldn't find useable FH with same pid, try any available */
1264         if (!any_available) {
1265                 any_available = true;
1266                 goto refind_writable;
1267         }
1268         read_unlock(&GlobalSMBSeslock);
1269         return NULL;
1270 }
1271
1272 static int cifs_partialpagewrite(struct page *page, unsigned from, unsigned to)
1273 {
1274         struct address_space *mapping = page->mapping;
1275         loff_t offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
1276         char *write_data;
1277         int rc = -EFAULT;
1278         int bytes_written = 0;
1279         struct cifs_sb_info *cifs_sb;
1280         struct cifsTconInfo *pTcon;
1281         struct inode *inode;
1282         struct cifsFileInfo *open_file;
1283
1284         if (!mapping || !mapping->host)
1285                 return -EFAULT;
1286
1287         inode = page->mapping->host;
1288         cifs_sb = CIFS_SB(inode->i_sb);
1289         pTcon = cifs_sb->tcon;
1290
1291         offset += (loff_t)from;
1292         write_data = kmap(page);
1293         write_data += from;
1294
1295         if ((to > PAGE_CACHE_SIZE) || (from > to)) {
1296                 kunmap(page);
1297                 return -EIO;
1298         }
1299
1300         /* racing with truncate? */
1301         if (offset > mapping->host->i_size) {
1302                 kunmap(page);
1303                 return 0; /* don't care */
1304         }
1305
1306         /* check to make sure that we are not extending the file */
1307         if (mapping->host->i_size - offset < (loff_t)to)
1308                 to = (unsigned)(mapping->host->i_size - offset);
1309
1310         open_file = find_writable_file(CIFS_I(mapping->host));
1311         if (open_file) {
1312                 bytes_written = cifs_write(open_file->pfile, write_data,
1313                                            to-from, &offset);
1314                 cifsFileInfo_put(open_file);
1315                 /* Does mm or vfs already set times? */
1316                 inode->i_atime = inode->i_mtime = current_fs_time(inode->i_sb);
1317                 if ((bytes_written > 0) && (offset))
1318                         rc = 0;
1319                 else if (bytes_written < 0)
1320                         rc = bytes_written;
1321         } else {
1322                 cFYI(1, "No writeable filehandles for inode");
1323                 rc = -EIO;
1324         }
1325
1326         kunmap(page);
1327         return rc;
1328 }
1329
1330 static int cifs_writepages(struct address_space *mapping,
1331                            struct writeback_control *wbc)
1332 {
1333         struct backing_dev_info *bdi = mapping->backing_dev_info;
1334         unsigned int bytes_to_write;
1335         unsigned int bytes_written;
1336         struct cifs_sb_info *cifs_sb;
1337         int done = 0;
1338         pgoff_t end;
1339         pgoff_t index;
1340         int range_whole = 0;
1341         struct kvec *iov;
1342         int len;
1343         int n_iov = 0;
1344         pgoff_t next;
1345         int nr_pages;
1346         __u64 offset = 0;
1347         struct cifsFileInfo *open_file;
1348         struct cifsInodeInfo *cifsi = CIFS_I(mapping->host);
1349         struct page *page;
1350         struct pagevec pvec;
1351         int rc = 0;
1352         int scanned = 0;
1353         int xid, long_op;
1354
1355         cifs_sb = CIFS_SB(mapping->host->i_sb);
1356
1357         /*
1358          * If wsize is smaller that the page cache size, default to writing
1359          * one page at a time via cifs_writepage
1360          */
1361         if (cifs_sb->wsize < PAGE_CACHE_SIZE)
1362                 return generic_writepages(mapping, wbc);
1363
1364         if ((cifs_sb->tcon->ses) && (cifs_sb->tcon->ses->server))
1365                 if (cifs_sb->tcon->ses->server->secMode &
1366                                 (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED))
1367                         if (!experimEnabled)
1368                                 return generic_writepages(mapping, wbc);
1369
1370         iov = kmalloc(32 * sizeof(struct kvec), GFP_KERNEL);
1371         if (iov == NULL)
1372                 return generic_writepages(mapping, wbc);
1373
1374
1375         /*
1376          * BB: Is this meaningful for a non-block-device file system?
1377          * If it is, we should test it again after we do I/O
1378          */
1379         if (wbc->nonblocking && bdi_write_congested(bdi)) {
1380                 wbc->encountered_congestion = 1;
1381                 kfree(iov);
1382                 return 0;
1383         }
1384
1385         xid = GetXid();
1386
1387         pagevec_init(&pvec, 0);
1388         if (wbc->range_cyclic) {
1389                 index = mapping->writeback_index; /* Start from prev offset */
1390                 end = -1;
1391         } else {
1392                 index = wbc->range_start >> PAGE_CACHE_SHIFT;
1393                 end = wbc->range_end >> PAGE_CACHE_SHIFT;
1394                 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
1395                         range_whole = 1;
1396                 scanned = 1;
1397         }
1398 retry:
1399         while (!done && (index <= end) &&
1400                (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
1401                         PAGECACHE_TAG_DIRTY,
1402                         min(end - index, (pgoff_t)PAGEVEC_SIZE - 1) + 1))) {
1403                 int first;
1404                 unsigned int i;
1405
1406                 first = -1;
1407                 next = 0;
1408                 n_iov = 0;
1409                 bytes_to_write = 0;
1410
1411                 for (i = 0; i < nr_pages; i++) {
1412                         page = pvec.pages[i];
1413                         /*
1414                          * At this point we hold neither mapping->tree_lock nor
1415                          * lock on the page itself: the page may be truncated or
1416                          * invalidated (changing page->mapping to NULL), or even
1417                          * swizzled back from swapper_space to tmpfs file
1418                          * mapping
1419                          */
1420
1421                         if (first < 0)
1422                                 lock_page(page);
1423                         else if (!trylock_page(page))
1424                                 break;
1425
1426                         if (unlikely(page->mapping != mapping)) {
1427                                 unlock_page(page);
1428                                 break;
1429                         }
1430
1431                         if (!wbc->range_cyclic && page->index > end) {
1432                                 done = 1;
1433                                 unlock_page(page);
1434                                 break;
1435                         }
1436
1437                         if (next && (page->index != next)) {
1438                                 /* Not next consecutive page */
1439                                 unlock_page(page);
1440                                 break;
1441                         }
1442
1443                         if (wbc->sync_mode != WB_SYNC_NONE)
1444                                 wait_on_page_writeback(page);
1445
1446                         if (PageWriteback(page) ||
1447                                         !clear_page_dirty_for_io(page)) {
1448                                 unlock_page(page);
1449                                 break;
1450                         }
1451
1452                         /*
1453                          * This actually clears the dirty bit in the radix tree.
1454                          * See cifs_writepage() for more commentary.
1455                          */
1456                         set_page_writeback(page);
1457
1458                         if (page_offset(page) >= mapping->host->i_size) {
1459                                 done = 1;
1460                                 unlock_page(page);
1461                                 end_page_writeback(page);
1462                                 break;
1463                         }
1464
1465                         /*
1466                          * BB can we get rid of this?  pages are held by pvec
1467                          */
1468                         page_cache_get(page);
1469
1470                         len = min(mapping->host->i_size - page_offset(page),
1471                                   (loff_t)PAGE_CACHE_SIZE);
1472
1473                         /* reserve iov[0] for the smb header */
1474                         n_iov++;
1475                         iov[n_iov].iov_base = kmap(page);
1476                         iov[n_iov].iov_len = len;
1477                         bytes_to_write += len;
1478
1479                         if (first < 0) {
1480                                 first = i;
1481                                 offset = page_offset(page);
1482                         }
1483                         next = page->index + 1;
1484                         if (bytes_to_write + PAGE_CACHE_SIZE > cifs_sb->wsize)
1485                                 break;
1486                 }
1487                 if (n_iov) {
1488                         /* Search for a writable handle every time we call
1489                          * CIFSSMBWrite2.  We can't rely on the last handle
1490                          * we used to still be valid
1491                          */
1492                         open_file = find_writable_file(CIFS_I(mapping->host));
1493                         if (!open_file) {
1494                                 cERROR(1, "No writable handles for inode");
1495                                 rc = -EBADF;
1496                         } else {
1497                                 long_op = cifs_write_timeout(cifsi, offset);
1498                                 rc = CIFSSMBWrite2(xid, cifs_sb->tcon,
1499                                                    open_file->netfid,
1500                                                    bytes_to_write, offset,
1501                                                    &bytes_written, iov, n_iov,
1502                                                    long_op);
1503                                 cifsFileInfo_put(open_file);
1504                                 cifs_update_eof(cifsi, offset, bytes_written);
1505
1506                                 if (rc || bytes_written < bytes_to_write) {
1507                                         cERROR(1, "Write2 ret %d, wrote %d",
1508                                                   rc, bytes_written);
1509                                         /* BB what if continued retry is
1510                                            requested via mount flags? */
1511                                         if (rc == -ENOSPC)
1512                                                 set_bit(AS_ENOSPC, &mapping->flags);
1513                                         else
1514                                                 set_bit(AS_EIO, &mapping->flags);
1515                                 } else {
1516                                         cifs_stats_bytes_written(cifs_sb->tcon,
1517                                                                  bytes_written);
1518                                 }
1519                         }
1520                         for (i = 0; i < n_iov; i++) {
1521                                 page = pvec.pages[first + i];
1522                                 /* Should we also set page error on
1523                                 success rc but too little data written? */
1524                                 /* BB investigate retry logic on temporary
1525                                 server crash cases and how recovery works
1526                                 when page marked as error */
1527                                 if (rc)
1528                                         SetPageError(page);
1529                                 kunmap(page);
1530                                 unlock_page(page);
1531                                 end_page_writeback(page);
1532                                 page_cache_release(page);
1533                         }
1534                         if ((wbc->nr_to_write -= n_iov) <= 0)
1535                                 done = 1;
1536                         index = next;
1537                 } else
1538                         /* Need to re-find the pages we skipped */
1539                         index = pvec.pages[0]->index + 1;
1540
1541                 pagevec_release(&pvec);
1542         }
1543         if (!scanned && !done) {
1544                 /*
1545                  * We hit the last page and there is more work to be done: wrap
1546                  * back to the start of the file
1547                  */
1548                 scanned = 1;
1549                 index = 0;
1550                 goto retry;
1551         }
1552         if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
1553                 mapping->writeback_index = index;
1554
1555         FreeXid(xid);
1556         kfree(iov);
1557         return rc;
1558 }
1559
1560 static int cifs_writepage(struct page *page, struct writeback_control *wbc)
1561 {
1562         int rc = -EFAULT;
1563         int xid;
1564
1565         xid = GetXid();
1566 /* BB add check for wbc flags */
1567         page_cache_get(page);
1568         if (!PageUptodate(page))
1569                 cFYI(1, "ppw - page not up to date");
1570
1571         /*
1572          * Set the "writeback" flag, and clear "dirty" in the radix tree.
1573          *
1574          * A writepage() implementation always needs to do either this,
1575          * or re-dirty the page with "redirty_page_for_writepage()" in
1576          * the case of a failure.
1577          *
1578          * Just unlocking the page will cause the radix tree tag-bits
1579          * to fail to update with the state of the page correctly.
1580          */
1581         set_page_writeback(page);
1582         rc = cifs_partialpagewrite(page, 0, PAGE_CACHE_SIZE);
1583         SetPageUptodate(page); /* BB add check for error and Clearuptodate? */
1584         unlock_page(page);
1585         end_page_writeback(page);
1586         page_cache_release(page);
1587         FreeXid(xid);
1588         return rc;
1589 }
1590
1591 static int cifs_write_end(struct file *file, struct address_space *mapping,
1592                         loff_t pos, unsigned len, unsigned copied,
1593                         struct page *page, void *fsdata)
1594 {
1595         int rc;
1596         struct inode *inode = mapping->host;
1597
1598         cFYI(1, "write_end for page %p from pos %lld with %d bytes",
1599                  page, pos, copied);
1600
1601         if (PageChecked(page)) {
1602                 if (copied == len)
1603                         SetPageUptodate(page);
1604                 ClearPageChecked(page);
1605         } else if (!PageUptodate(page) && copied == PAGE_CACHE_SIZE)
1606                 SetPageUptodate(page);
1607
1608         if (!PageUptodate(page)) {
1609                 char *page_data;
1610                 unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
1611                 int xid;
1612
1613                 xid = GetXid();
1614                 /* this is probably better than directly calling
1615                    partialpage_write since in this function the file handle is
1616                    known which we might as well leverage */
1617                 /* BB check if anything else missing out of ppw
1618                    such as updating last write time */
1619                 page_data = kmap(page);
1620                 rc = cifs_write(file, page_data + offset, copied, &pos);
1621                 /* if (rc < 0) should we set writebehind rc? */
1622                 kunmap(page);
1623
1624                 FreeXid(xid);
1625         } else {
1626                 rc = copied;
1627                 pos += copied;
1628                 set_page_dirty(page);
1629         }
1630
1631         if (rc > 0) {
1632                 spin_lock(&inode->i_lock);
1633                 if (pos > inode->i_size)
1634                         i_size_write(inode, pos);
1635                 spin_unlock(&inode->i_lock);
1636         }
1637
1638         unlock_page(page);
1639         page_cache_release(page);
1640
1641         return rc;
1642 }
1643
1644 int cifs_fsync(struct file *file, int datasync)
1645 {
1646         int xid;
1647         int rc = 0;
1648         struct cifsTconInfo *tcon;
1649         struct cifsFileInfo *smbfile =
1650                 (struct cifsFileInfo *)file->private_data;
1651         struct inode *inode = file->f_path.dentry->d_inode;
1652
1653         xid = GetXid();
1654
1655         cFYI(1, "Sync file - name: %s datasync: 0x%x",
1656                 file->f_path.dentry->d_name.name, datasync);
1657
1658         rc = filemap_write_and_wait(inode->i_mapping);
1659         if (rc == 0) {
1660                 rc = CIFS_I(inode)->write_behind_rc;
1661                 CIFS_I(inode)->write_behind_rc = 0;
1662                 tcon = CIFS_SB(inode->i_sb)->tcon;
1663                 if (!rc && tcon && smbfile &&
1664                    !(CIFS_SB(inode->i_sb)->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC))
1665                         rc = CIFSSMBFlush(xid, tcon, smbfile->netfid);
1666         }
1667
1668         FreeXid(xid);
1669         return rc;
1670 }
1671
1672 /* static void cifs_sync_page(struct page *page)
1673 {
1674         struct address_space *mapping;
1675         struct inode *inode;
1676         unsigned long index = page->index;
1677         unsigned int rpages = 0;
1678         int rc = 0;
1679
1680         cFYI(1, "sync page %p", page);
1681         mapping = page->mapping;
1682         if (!mapping)
1683                 return 0;
1684         inode = mapping->host;
1685         if (!inode)
1686                 return; */
1687
1688 /*      fill in rpages then
1689         result = cifs_pagein_inode(inode, index, rpages); */ /* BB finish */
1690
1691 /*      cFYI(1, "rpages is %d for sync page of Index %ld", rpages, index);
1692
1693 #if 0
1694         if (rc < 0)
1695                 return rc;
1696         return 0;
1697 #endif
1698 } */
1699
1700 /*
1701  * As file closes, flush all cached write data for this inode checking
1702  * for write behind errors.
1703  */
1704 int cifs_flush(struct file *file, fl_owner_t id)
1705 {
1706         struct inode *inode = file->f_path.dentry->d_inode;
1707         int rc = 0;
1708
1709         /* Rather than do the steps manually:
1710            lock the inode for writing
1711            loop through pages looking for write behind data (dirty pages)
1712            coalesce into contiguous 16K (or smaller) chunks to write to server
1713            send to server (prefer in parallel)
1714            deal with writebehind errors
1715            unlock inode for writing
1716            filemapfdatawrite appears easier for the time being */
1717
1718         rc = filemap_fdatawrite(inode->i_mapping);
1719         /* reset wb rc if we were able to write out dirty pages */
1720         if (!rc) {
1721                 rc = CIFS_I(inode)->write_behind_rc;
1722                 CIFS_I(inode)->write_behind_rc = 0;
1723         }
1724
1725         cFYI(1, "Flush inode %p file %p rc %d", inode, file, rc);
1726
1727         return rc;
1728 }
1729
1730 ssize_t cifs_user_read(struct file *file, char __user *read_data,
1731         size_t read_size, loff_t *poffset)
1732 {
1733         int rc = -EACCES;
1734         unsigned int bytes_read = 0;
1735         unsigned int total_read = 0;
1736         unsigned int current_read_size;
1737         struct cifs_sb_info *cifs_sb;
1738         struct cifsTconInfo *pTcon;
1739         int xid;
1740         struct cifsFileInfo *open_file;
1741         char *smb_read_data;
1742         char __user *current_offset;
1743         struct smb_com_read_rsp *pSMBr;
1744
1745         xid = GetXid();
1746         cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
1747         pTcon = cifs_sb->tcon;
1748
1749         if (file->private_data == NULL) {
1750                 rc = -EBADF;
1751                 FreeXid(xid);
1752                 return rc;
1753         }
1754         open_file = (struct cifsFileInfo *)file->private_data;
1755
1756         if ((file->f_flags & O_ACCMODE) == O_WRONLY)
1757                 cFYI(1, "attempting read on write only file instance");
1758
1759         for (total_read = 0, current_offset = read_data;
1760              read_size > total_read;
1761              total_read += bytes_read, current_offset += bytes_read) {
1762                 current_read_size = min_t(const int, read_size - total_read,
1763                                           cifs_sb->rsize);
1764                 rc = -EAGAIN;
1765                 smb_read_data = NULL;
1766                 while (rc == -EAGAIN) {
1767                         int buf_type = CIFS_NO_BUFFER;
1768                         if ((open_file->invalidHandle) &&
1769                             (!open_file->closePend)) {
1770                                 rc = cifs_reopen_file(file, true);
1771                                 if (rc != 0)
1772                                         break;
1773                         }
1774                         rc = CIFSSMBRead(xid, pTcon,
1775                                          open_file->netfid,
1776                                          current_read_size, *poffset,
1777                                          &bytes_read, &smb_read_data,
1778                                          &buf_type);
1779                         pSMBr = (struct smb_com_read_rsp *)smb_read_data;
1780                         if (smb_read_data) {
1781                                 if (copy_to_user(current_offset,
1782                                                 smb_read_data +
1783                                                 4 /* RFC1001 length field */ +
1784                                                 le16_to_cpu(pSMBr->DataOffset),
1785                                                 bytes_read))
1786                                         rc = -EFAULT;
1787
1788                                 if (buf_type == CIFS_SMALL_BUFFER)
1789                                         cifs_small_buf_release(smb_read_data);
1790                                 else if (buf_type == CIFS_LARGE_BUFFER)
1791                                         cifs_buf_release(smb_read_data);
1792                                 smb_read_data = NULL;
1793                         }
1794                 }
1795                 if (rc || (bytes_read == 0)) {
1796                         if (total_read) {
1797                                 break;
1798                         } else {
1799                                 FreeXid(xid);
1800                                 return rc;
1801                         }
1802                 } else {
1803                         cifs_stats_bytes_read(pTcon, bytes_read);
1804                         *poffset += bytes_read;
1805                 }
1806         }
1807         FreeXid(xid);
1808         return total_read;
1809 }
1810
1811
1812 static ssize_t cifs_read(struct file *file, char *read_data, size_t read_size,
1813         loff_t *poffset)
1814 {
1815         int rc = -EACCES;
1816         unsigned int bytes_read = 0;
1817         unsigned int total_read;
1818         unsigned int current_read_size;
1819         struct cifs_sb_info *cifs_sb;
1820         struct cifsTconInfo *pTcon;
1821         int xid;
1822         char *current_offset;
1823         struct cifsFileInfo *open_file;
1824         int buf_type = CIFS_NO_BUFFER;
1825
1826         xid = GetXid();
1827         cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
1828         pTcon = cifs_sb->tcon;
1829
1830         if (file->private_data == NULL) {
1831                 rc = -EBADF;
1832                 FreeXid(xid);
1833                 return rc;
1834         }
1835         open_file = (struct cifsFileInfo *)file->private_data;
1836
1837         if ((file->f_flags & O_ACCMODE) == O_WRONLY)
1838                 cFYI(1, "attempting read on write only file instance");
1839
1840         for (total_read = 0, current_offset = read_data;
1841              read_size > total_read;
1842              total_read += bytes_read, current_offset += bytes_read) {
1843                 current_read_size = min_t(const int, read_size - total_read,
1844                                           cifs_sb->rsize);
1845                 /* For windows me and 9x we do not want to request more
1846                 than it negotiated since it will refuse the read then */
1847                 if ((pTcon->ses) &&
1848                         !(pTcon->ses->capabilities & CAP_LARGE_FILES)) {
1849                         current_read_size = min_t(const int, current_read_size,
1850                                         pTcon->ses->server->maxBuf - 128);
1851                 }
1852                 rc = -EAGAIN;
1853                 while (rc == -EAGAIN) {
1854                         if ((open_file->invalidHandle) &&
1855                             (!open_file->closePend)) {
1856                                 rc = cifs_reopen_file(file, true);
1857                                 if (rc != 0)
1858                                         break;
1859                         }
1860                         rc = CIFSSMBRead(xid, pTcon,
1861                                          open_file->netfid,
1862                                          current_read_size, *poffset,
1863                                          &bytes_read, &current_offset,
1864                                          &buf_type);
1865                 }
1866                 if (rc || (bytes_read == 0)) {
1867                         if (total_read) {
1868                                 break;
1869                         } else {
1870                                 FreeXid(xid);
1871                                 return rc;
1872                         }
1873                 } else {
1874                         cifs_stats_bytes_read(pTcon, total_read);
1875                         *poffset += bytes_read;
1876                 }
1877         }
1878         FreeXid(xid);
1879         return total_read;
1880 }
1881
1882 int cifs_file_mmap(struct file *file, struct vm_area_struct *vma)
1883 {
1884         int rc, xid;
1885
1886         xid = GetXid();
1887         rc = cifs_revalidate_file(file);
1888         if (rc) {
1889                 cFYI(1, "Validation prior to mmap failed, error=%d", rc);
1890                 FreeXid(xid);
1891                 return rc;
1892         }
1893         rc = generic_file_mmap(file, vma);
1894         FreeXid(xid);
1895         return rc;
1896 }
1897
1898
1899 static void cifs_copy_cache_pages(struct address_space *mapping,
1900         struct list_head *pages, int bytes_read, char *data)
1901 {
1902         struct page *page;
1903         char *target;
1904
1905         while (bytes_read > 0) {
1906                 if (list_empty(pages))
1907                         break;
1908
1909                 page = list_entry(pages->prev, struct page, lru);
1910                 list_del(&page->lru);
1911
1912                 if (add_to_page_cache_lru(page, mapping, page->index,
1913                                       GFP_KERNEL)) {
1914                         page_cache_release(page);
1915                         cFYI(1, "Add page cache failed");
1916                         data += PAGE_CACHE_SIZE;
1917                         bytes_read -= PAGE_CACHE_SIZE;
1918                         continue;
1919                 }
1920                 page_cache_release(page);
1921
1922                 target = kmap_atomic(page, KM_USER0);
1923
1924                 if (PAGE_CACHE_SIZE > bytes_read) {
1925                         memcpy(target, data, bytes_read);
1926                         /* zero the tail end of this partial page */
1927                         memset(target + bytes_read, 0,
1928                                PAGE_CACHE_SIZE - bytes_read);
1929                         bytes_read = 0;
1930                 } else {
1931                         memcpy(target, data, PAGE_CACHE_SIZE);
1932                         bytes_read -= PAGE_CACHE_SIZE;
1933                 }
1934                 kunmap_atomic(target, KM_USER0);
1935
1936                 flush_dcache_page(page);
1937                 SetPageUptodate(page);
1938                 unlock_page(page);
1939                 data += PAGE_CACHE_SIZE;
1940         }
1941         return;
1942 }
1943
1944 static int cifs_readpages(struct file *file, struct address_space *mapping,
1945         struct list_head *page_list, unsigned num_pages)
1946 {
1947         int rc = -EACCES;
1948         int xid;
1949         loff_t offset;
1950         struct page *page;
1951         struct cifs_sb_info *cifs_sb;
1952         struct cifsTconInfo *pTcon;
1953         unsigned int bytes_read = 0;
1954         unsigned int read_size, i;
1955         char *smb_read_data = NULL;
1956         struct smb_com_read_rsp *pSMBr;
1957         struct cifsFileInfo *open_file;
1958         int buf_type = CIFS_NO_BUFFER;
1959
1960         xid = GetXid();
1961         if (file->private_data == NULL) {
1962                 rc = -EBADF;
1963                 FreeXid(xid);
1964                 return rc;
1965         }
1966         open_file = (struct cifsFileInfo *)file->private_data;
1967         cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
1968         pTcon = cifs_sb->tcon;
1969
1970         cFYI(DBG2, "rpages: num pages %d", num_pages);
1971         for (i = 0; i < num_pages; ) {
1972                 unsigned contig_pages;
1973                 struct page *tmp_page;
1974                 unsigned long expected_index;
1975
1976                 if (list_empty(page_list))
1977                         break;
1978
1979                 page = list_entry(page_list->prev, struct page, lru);
1980                 offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
1981
1982                 /* count adjacent pages that we will read into */
1983                 contig_pages = 0;
1984                 expected_index =
1985                         list_entry(page_list->prev, struct page, lru)->index;
1986                 list_for_each_entry_reverse(tmp_page, page_list, lru) {
1987                         if (tmp_page->index == expected_index) {
1988                                 contig_pages++;
1989                                 expected_index++;
1990                         } else
1991                                 break;
1992                 }
1993                 if (contig_pages + i >  num_pages)
1994                         contig_pages = num_pages - i;
1995
1996                 /* for reads over a certain size could initiate async
1997                    read ahead */
1998
1999                 read_size = contig_pages * PAGE_CACHE_SIZE;
2000                 /* Read size needs to be in multiples of one page */
2001                 read_size = min_t(const unsigned int, read_size,
2002                                   cifs_sb->rsize & PAGE_CACHE_MASK);
2003                 cFYI(DBG2, "rpages: read size 0x%x  contiguous pages %d",
2004                                 read_size, contig_pages);
2005                 rc = -EAGAIN;
2006                 while (rc == -EAGAIN) {
2007                         if ((open_file->invalidHandle) &&
2008                             (!open_file->closePend)) {
2009                                 rc = cifs_reopen_file(file, true);
2010                                 if (rc != 0)
2011                                         break;
2012                         }
2013
2014                         rc = CIFSSMBRead(xid, pTcon,
2015                                          open_file->netfid,
2016                                          read_size, offset,
2017                                          &bytes_read, &smb_read_data,
2018                                          &buf_type);
2019                         /* BB more RC checks ? */
2020                         if (rc == -EAGAIN) {
2021                                 if (smb_read_data) {
2022                                         if (buf_type == CIFS_SMALL_BUFFER)
2023                                                 cifs_small_buf_release(smb_read_data);
2024                                         else if (buf_type == CIFS_LARGE_BUFFER)
2025                                                 cifs_buf_release(smb_read_data);
2026                                         smb_read_data = NULL;
2027                                 }
2028                         }
2029                 }
2030                 if ((rc < 0) || (smb_read_data == NULL)) {
2031                         cFYI(1, "Read error in readpages: %d", rc);
2032                         break;
2033                 } else if (bytes_read > 0) {
2034                         task_io_account_read(bytes_read);
2035                         pSMBr = (struct smb_com_read_rsp *)smb_read_data;
2036                         cifs_copy_cache_pages(mapping, page_list, bytes_read,
2037                                 smb_read_data + 4 /* RFC1001 hdr */ +
2038                                 le16_to_cpu(pSMBr->DataOffset));
2039
2040                         i +=  bytes_read >> PAGE_CACHE_SHIFT;
2041                         cifs_stats_bytes_read(pTcon, bytes_read);
2042                         if ((bytes_read & PAGE_CACHE_MASK) != bytes_read) {
2043                                 i++; /* account for partial page */
2044
2045                                 /* server copy of file can have smaller size
2046                                    than client */
2047                                 /* BB do we need to verify this common case ?
2048                                    this case is ok - if we are at server EOF
2049                                    we will hit it on next read */
2050
2051                                 /* break; */
2052                         }
2053                 } else {
2054                         cFYI(1, "No bytes read (%d) at offset %lld . "
2055                                 "Cleaning remaining pages from readahead list",
2056                                 bytes_read, offset);
2057                         /* BB turn off caching and do new lookup on
2058                            file size at server? */
2059                         break;
2060                 }
2061                 if (smb_read_data) {
2062                         if (buf_type == CIFS_SMALL_BUFFER)
2063                                 cifs_small_buf_release(smb_read_data);
2064                         else if (buf_type == CIFS_LARGE_BUFFER)
2065                                 cifs_buf_release(smb_read_data);
2066                         smb_read_data = NULL;
2067                 }
2068                 bytes_read = 0;
2069         }
2070
2071 /* need to free smb_read_data buf before exit */
2072         if (smb_read_data) {
2073                 if (buf_type == CIFS_SMALL_BUFFER)
2074                         cifs_small_buf_release(smb_read_data);
2075                 else if (buf_type == CIFS_LARGE_BUFFER)
2076                         cifs_buf_release(smb_read_data);
2077                 smb_read_data = NULL;
2078         }
2079
2080         FreeXid(xid);
2081         return rc;
2082 }
2083
2084 static int cifs_readpage_worker(struct file *file, struct page *page,
2085         loff_t *poffset)
2086 {
2087         char *read_data;
2088         int rc;
2089
2090         page_cache_get(page);
2091         read_data = kmap(page);
2092         /* for reads over a certain size could initiate async read ahead */
2093
2094         rc = cifs_read(file, read_data, PAGE_CACHE_SIZE, poffset);
2095
2096         if (rc < 0)
2097                 goto io_error;
2098         else
2099                 cFYI(1, "Bytes read %d", rc);
2100
2101         file->f_path.dentry->d_inode->i_atime =
2102                 current_fs_time(file->f_path.dentry->d_inode->i_sb);
2103
2104         if (PAGE_CACHE_SIZE > rc)
2105                 memset(read_data + rc, 0, PAGE_CACHE_SIZE - rc);
2106
2107         flush_dcache_page(page);
2108         SetPageUptodate(page);
2109         rc = 0;
2110
2111 io_error:
2112         kunmap(page);
2113         page_cache_release(page);
2114         return rc;
2115 }
2116
2117 static int cifs_readpage(struct file *file, struct page *page)
2118 {
2119         loff_t offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
2120         int rc = -EACCES;
2121         int xid;
2122
2123         xid = GetXid();
2124
2125         if (file->private_data == NULL) {
2126                 rc = -EBADF;
2127                 FreeXid(xid);
2128                 return rc;
2129         }
2130
2131         cFYI(1, "readpage %p at offset %d 0x%x\n",
2132                  page, (int)offset, (int)offset);
2133
2134         rc = cifs_readpage_worker(file, page, &offset);
2135
2136         unlock_page(page);
2137
2138         FreeXid(xid);
2139         return rc;
2140 }
2141
2142 static int is_inode_writable(struct cifsInodeInfo *cifs_inode)
2143 {
2144         struct cifsFileInfo *open_file;
2145
2146         read_lock(&GlobalSMBSeslock);
2147         list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
2148                 if (open_file->closePend)
2149                         continue;
2150                 if (open_file->pfile &&
2151                     ((open_file->pfile->f_flags & O_RDWR) ||
2152                      (open_file->pfile->f_flags & O_WRONLY))) {
2153                         read_unlock(&GlobalSMBSeslock);
2154                         return 1;
2155                 }
2156         }
2157         read_unlock(&GlobalSMBSeslock);
2158         return 0;
2159 }
2160
2161 /* We do not want to update the file size from server for inodes
2162    open for write - to avoid races with writepage extending
2163    the file - in the future we could consider allowing
2164    refreshing the inode only on increases in the file size
2165    but this is tricky to do without racing with writebehind
2166    page caching in the current Linux kernel design */
2167 bool is_size_safe_to_change(struct cifsInodeInfo *cifsInode, __u64 end_of_file)
2168 {
2169         if (!cifsInode)
2170                 return true;
2171
2172         if (is_inode_writable(cifsInode)) {
2173                 /* This inode is open for write at least once */
2174                 struct cifs_sb_info *cifs_sb;
2175
2176                 cifs_sb = CIFS_SB(cifsInode->vfs_inode.i_sb);
2177                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DIRECT_IO) {
2178                         /* since no page cache to corrupt on directio
2179                         we can change size safely */
2180                         return true;
2181                 }
2182
2183                 if (i_size_read(&cifsInode->vfs_inode) < end_of_file)
2184                         return true;
2185
2186                 return false;
2187         } else
2188                 return true;
2189 }
2190
2191 static int cifs_write_begin(struct file *file, struct address_space *mapping,
2192                         loff_t pos, unsigned len, unsigned flags,
2193                         struct page **pagep, void **fsdata)
2194 {
2195         pgoff_t index = pos >> PAGE_CACHE_SHIFT;
2196         loff_t offset = pos & (PAGE_CACHE_SIZE - 1);
2197         loff_t page_start = pos & PAGE_MASK;
2198         loff_t i_size;
2199         struct page *page;
2200         int rc = 0;
2201
2202         cFYI(1, "write_begin from %lld len %d", (long long)pos, len);
2203
2204         page = grab_cache_page_write_begin(mapping, index, flags);
2205         if (!page) {
2206                 rc = -ENOMEM;
2207                 goto out;
2208         }
2209
2210         if (PageUptodate(page))
2211                 goto out;
2212
2213         /*
2214          * If we write a full page it will be up to date, no need to read from
2215          * the server. If the write is short, we'll end up doing a sync write
2216          * instead.
2217          */
2218         if (len == PAGE_CACHE_SIZE)
2219                 goto out;
2220
2221         /*
2222          * optimize away the read when we have an oplock, and we're not
2223          * expecting to use any of the data we'd be reading in. That
2224          * is, when the page lies beyond the EOF, or straddles the EOF
2225          * and the write will cover all of the existing data.
2226          */
2227         if (CIFS_I(mapping->host)->clientCanCacheRead) {
2228                 i_size = i_size_read(mapping->host);
2229                 if (page_start >= i_size ||
2230                     (offset == 0 && (pos + len) >= i_size)) {
2231                         zero_user_segments(page, 0, offset,
2232                                            offset + len,
2233                                            PAGE_CACHE_SIZE);
2234                         /*
2235                          * PageChecked means that the parts of the page
2236                          * to which we're not writing are considered up
2237                          * to date. Once the data is copied to the
2238                          * page, it can be set uptodate.
2239                          */
2240                         SetPageChecked(page);
2241                         goto out;
2242                 }
2243         }
2244
2245         if ((file->f_flags & O_ACCMODE) != O_WRONLY) {
2246                 /*
2247                  * might as well read a page, it is fast enough. If we get
2248                  * an error, we don't need to return it. cifs_write_end will
2249                  * do a sync write instead since PG_uptodate isn't set.
2250                  */
2251                 cifs_readpage_worker(file, page, &page_start);
2252         } else {
2253                 /* we could try using another file handle if there is one -
2254                    but how would we lock it to prevent close of that handle
2255                    racing with this read? In any case
2256                    this will be written out by write_end so is fine */
2257         }
2258 out:
2259         *pagep = page;
2260         return rc;
2261 }
2262
2263 static void
2264 cifs_oplock_break(struct slow_work *work)
2265 {
2266         struct cifsFileInfo *cfile = container_of(work, struct cifsFileInfo,
2267                                                   oplock_break);
2268         struct inode *inode = cfile->pInode;
2269         struct cifsInodeInfo *cinode = CIFS_I(inode);
2270         struct cifs_sb_info *cifs_sb = CIFS_SB(cfile->mnt->mnt_sb);
2271         int rc, waitrc = 0;
2272
2273         if (inode && S_ISREG(inode->i_mode)) {
2274                 if (cinode->clientCanCacheRead)
2275                         break_lease(inode, O_RDONLY);
2276                 else
2277                         break_lease(inode, O_WRONLY);
2278                 rc = filemap_fdatawrite(inode->i_mapping);
2279                 if (cinode->clientCanCacheRead == 0) {
2280                         waitrc = filemap_fdatawait(inode->i_mapping);
2281                         invalidate_remote_inode(inode);
2282                 }
2283                 if (!rc)
2284                         rc = waitrc;
2285                 if (rc)
2286                         cinode->write_behind_rc = rc;
2287                 cFYI(1, "Oplock flush inode %p rc %d", inode, rc);
2288         }
2289
2290         /*
2291          * releasing stale oplock after recent reconnect of smb session using
2292          * a now incorrect file handle is not a data integrity issue but do
2293          * not bother sending an oplock release if session to server still is
2294          * disconnected since oplock already released by the server
2295          */
2296         if (!cfile->closePend && !cfile->oplock_break_cancelled) {
2297                 rc = CIFSSMBLock(0, cifs_sb->tcon, cfile->netfid, 0, 0, 0, 0,
2298                                  LOCKING_ANDX_OPLOCK_RELEASE, false);
2299                 cFYI(1, "Oplock release rc = %d", rc);
2300         }
2301 }
2302
2303 static int
2304 cifs_oplock_break_get(struct slow_work *work)
2305 {
2306         struct cifsFileInfo *cfile = container_of(work, struct cifsFileInfo,
2307                                                   oplock_break);
2308         mntget(cfile->mnt);
2309         cifsFileInfo_get(cfile);
2310         return 0;
2311 }
2312
2313 static void
2314 cifs_oplock_break_put(struct slow_work *work)
2315 {
2316         struct cifsFileInfo *cfile = container_of(work, struct cifsFileInfo,
2317                                                   oplock_break);
2318         mntput(cfile->mnt);
2319         cifsFileInfo_put(cfile);
2320 }
2321
2322 const struct slow_work_ops cifs_oplock_break_ops = {
2323         .get_ref        = cifs_oplock_break_get,
2324         .put_ref        = cifs_oplock_break_put,
2325         .execute        = cifs_oplock_break,
2326 };
2327
2328 const struct address_space_operations cifs_addr_ops = {
2329         .readpage = cifs_readpage,
2330         .readpages = cifs_readpages,
2331         .writepage = cifs_writepage,
2332         .writepages = cifs_writepages,
2333         .write_begin = cifs_write_begin,
2334         .write_end = cifs_write_end,
2335         .set_page_dirty = __set_page_dirty_nobuffers,
2336         /* .sync_page = cifs_sync_page, */
2337         /* .direct_IO = */
2338 };
2339
2340 /*
2341  * cifs_readpages requires the server to support a buffer large enough to
2342  * contain the header plus one complete page of data.  Otherwise, we need
2343  * to leave cifs_readpages out of the address space operations.
2344  */
2345 const struct address_space_operations cifs_addr_ops_smallbuf = {
2346         .readpage = cifs_readpage,
2347         .writepage = cifs_writepage,
2348         .writepages = cifs_writepages,
2349         .write_begin = cifs_write_begin,
2350         .write_end = cifs_write_end,
2351         .set_page_dirty = __set_page_dirty_nobuffers,
2352         /* .sync_page = cifs_sync_page, */
2353         /* .direct_IO = */
2354 };