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 <linux/swap.h>
  36 #include <asm/div64.h>
  37 #include "cifsfs.h"
  38 #include "cifspdu.h"
  39 #include "cifsglob.h"
  40 #include "cifsproto.h"
  41 #include "cifs_unicode.h"
  42 #include "cifs_debug.h"
  43 #include "cifs_fs_sb.h"
  44 #include "fscache.h"
  45
  46 static inline int cifs_convert_flags(unsigned int flags)
  47 {
  48         if ((flags & O_ACCMODE) == O_RDONLY)
  49                 return GENERIC_READ;
  50         else if ((flags & O_ACCMODE) == O_WRONLY)
  51                 return GENERIC_WRITE;
  52         else if ((flags & O_ACCMODE) == O_RDWR) {
  53                 /* GENERIC_ALL is too much permission to request
  54                    can cause unnecessary access denied on create */
  55                 /* return GENERIC_ALL; */
  56                 return (GENERIC_READ | GENERIC_WRITE);
  57         }
  58
  59         return (READ_CONTROL | FILE_WRITE_ATTRIBUTES | FILE_READ_ATTRIBUTES |
  60                 FILE_WRITE_EA | FILE_APPEND_DATA | FILE_WRITE_DATA |
  61                 FILE_READ_DATA);
  62 }
  63
  64 static u32 cifs_posix_convert_flags(unsigned int flags)
  65 {
  66         u32 posix_flags = 0;
  67
  68         if ((flags & O_ACCMODE) == O_RDONLY)
  69                 posix_flags = SMB_O_RDONLY;
  70         else if ((flags & O_ACCMODE) == O_WRONLY)
  71                 posix_flags = SMB_O_WRONLY;
  72         else if ((flags & O_ACCMODE) == O_RDWR)
  73                 posix_flags = SMB_O_RDWR;
  74
  75         if (flags & O_CREAT)
  76                 posix_flags |= SMB_O_CREAT;
  77         if (flags & O_EXCL)
  78                 posix_flags |= SMB_O_EXCL;
  79         if (flags & O_TRUNC)
  80                 posix_flags |= SMB_O_TRUNC;
  81         /* be safe and imply O_SYNC for O_DSYNC */
  82         if (flags & O_DSYNC)
  83                 posix_flags |= SMB_O_SYNC;
  84         if (flags & O_DIRECTORY)
  85                 posix_flags |= SMB_O_DIRECTORY;
  86         if (flags & O_NOFOLLOW)
  87                 posix_flags |= SMB_O_NOFOLLOW;
  88         if (flags & O_DIRECT)
  89                 posix_flags |= SMB_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 int cifs_posix_open(char *full_path, struct inode **pinode,
 109                         struct super_block *sb, int mode, unsigned int f_flags,
 110                         __u32 *poplock, __u16 *pnetfid, unsigned int xid)
 111 {
 112         int rc;
 113         FILE_UNIX_BASIC_INFO *presp_data;
 114         __u32 posix_flags = 0;
 115         struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
 116         struct cifs_fattr fattr;
 117         struct tcon_link *tlink;
 118         struct cifs_tcon *tcon;
 119
 120         cFYI(1, "posix open %s", full_path);
 121
 122         presp_data = kzalloc(sizeof(FILE_UNIX_BASIC_INFO), GFP_KERNEL);
 123         if (presp_data == NULL)
 124                 return -ENOMEM;
 125
 126         tlink = cifs_sb_tlink(cifs_sb);
 127         if (IS_ERR(tlink)) {
 128                 rc = PTR_ERR(tlink);
 129                 goto posix_open_ret;
 130         }
 131
 132         tcon = tlink_tcon(tlink);
 133         mode &= ~current_umask();
 134
 135         posix_flags = cifs_posix_convert_flags(f_flags);
 136         rc = CIFSPOSIXCreate(xid, tcon, posix_flags, mode, pnetfid, presp_data,
 137                              poplock, full_path, cifs_sb->local_nls,
 138                              cifs_sb->mnt_cifs_flags &
 139                                         CIFS_MOUNT_MAP_SPECIAL_CHR);
 140         cifs_put_tlink(tlink);
 141
 142         if (rc)
 143                 goto posix_open_ret;
 144
 145         if (presp_data->Type == cpu_to_le32(-1))
 146                 goto posix_open_ret; /* open ok, caller does qpathinfo */
 147
 148         if (!pinode)
 149                 goto posix_open_ret; /* caller does not need info */
 150
 151         cifs_unix_basic_to_fattr(&fattr, presp_data, cifs_sb);
 152
 153         /* get new inode and set it up */
 154         if (*pinode == NULL) {
 155                 cifs_fill_uniqueid(sb, &fattr);
 156                 *pinode = cifs_iget(sb, &fattr);
 157                 if (!*pinode) {
 158                         rc = -ENOMEM;
 159                         goto posix_open_ret;
 160                 }
 161         } else {
 162                 cifs_fattr_to_inode(*pinode, &fattr);
 163         }
 164
 165 posix_open_ret:
 166         kfree(presp_data);
 167         return rc;
 168 }
 169
 170 static int
 171 cifs_nt_open(char *full_path, struct inode *inode, struct cifs_sb_info *cifs_sb,
 172              struct cifs_tcon *tcon, unsigned int f_flags, __u32 *poplock,
 173              __u16 *pnetfid, unsigned int xid)
 174 {
 175         int rc;
 176         int desiredAccess;
 177         int disposition;
 178         int create_options = CREATE_NOT_DIR;
 179         FILE_ALL_INFO *buf;
 180
 181         desiredAccess = cifs_convert_flags(f_flags);
 182
 183 /*********************************************************************
 184  *  open flag mapping table:
 185  *
 186  *      POSIX Flag            CIFS Disposition
 187  *      ----------            ----------------
 188  *      O_CREAT               FILE_OPEN_IF
 189  *      O_CREAT | O_EXCL      FILE_CREATE
 190  *      O_CREAT | O_TRUNC     FILE_OVERWRITE_IF
 191  *      O_TRUNC               FILE_OVERWRITE
 192  *      none of the above     FILE_OPEN
 193  *
 194  *      Note that there is not a direct match between disposition
 195  *      FILE_SUPERSEDE (ie create whether or not file exists although
 196  *      O_CREAT | O_TRUNC is similar but truncates the existing
 197  *      file rather than creating a new file as FILE_SUPERSEDE does
 198  *      (which uses the attributes / metadata passed in on open call)
 199  *?
 200  *?  O_SYNC is a reasonable match to CIFS writethrough flag
 201  *?  and the read write flags match reasonably.  O_LARGEFILE
 202  *?  is irrelevant because largefile support is always used
 203  *?  by this client. Flags O_APPEND, O_DIRECT, O_DIRECTORY,
 204  *       O_FASYNC, O_NOFOLLOW, O_NONBLOCK need further investigation
 205  *********************************************************************/
 206
 207         disposition = cifs_get_disposition(f_flags);
 208
 209         /* BB pass O_SYNC flag through on file attributes .. BB */
 210
 211         buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
 212         if (!buf)
 213                 return -ENOMEM;
 214
 215         if (backup_cred(cifs_sb))
 216                 create_options |= CREATE_OPEN_BACKUP_INTENT;
 217
 218         if (tcon->ses->capabilities & CAP_NT_SMBS)
 219                 rc = CIFSSMBOpen(xid, tcon, full_path, disposition,
 220                          desiredAccess, create_options, pnetfid, poplock, buf,
 221                          cifs_sb->local_nls, cifs_sb->mnt_cifs_flags
 222                                  & CIFS_MOUNT_MAP_SPECIAL_CHR);
 223         else
 224                 rc = SMBLegacyOpen(xid, tcon, full_path, disposition,
 225                         desiredAccess, CREATE_NOT_DIR, pnetfid, poplock, buf,
 226                         cifs_sb->local_nls, cifs_sb->mnt_cifs_flags
 227                                 & CIFS_MOUNT_MAP_SPECIAL_CHR);
 228
 229         if (rc)
 230                 goto out;
 231
 232         if (tcon->unix_ext)
 233                 rc = cifs_get_inode_info_unix(&inode, full_path, inode->i_sb,
 234                                               xid);
 235         else
 236                 rc = cifs_get_inode_info(&inode, full_path, buf, inode->i_sb,
 237                                          xid, pnetfid);
 238
 239 out:
 240         kfree(buf);
 241         return rc;
 242 }
 243
 244 struct cifsFileInfo *
 245 cifs_new_fileinfo(__u16 fileHandle, struct file *file,
 246                   struct tcon_link *tlink, __u32 oplock)
 247 {
 248         struct dentry *dentry = file->f_path.dentry;
 249         struct inode *inode = dentry->d_inode;
 250         struct cifsInodeInfo *pCifsInode = CIFS_I(inode);
 251         struct cifsFileInfo *pCifsFile;
 252
 253         pCifsFile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
 254         if (pCifsFile == NULL)
 255                 return pCifsFile;
 256
 257         pCifsFile->count = 1;
 258         pCifsFile->netfid = fileHandle;
 259         pCifsFile->pid = current->tgid;
 260         pCifsFile->uid = current_fsuid();
 261         pCifsFile->dentry = dget(dentry);
 262         pCifsFile->f_flags = file->f_flags;
 263         pCifsFile->invalidHandle = false;
 264         pCifsFile->tlink = cifs_get_tlink(tlink);
 265         mutex_init(&pCifsFile->fh_mutex);
 266         INIT_WORK(&pCifsFile->oplock_break, cifs_oplock_break);
 267         INIT_LIST_HEAD(&pCifsFile->llist);
 268
 269         spin_lock(&cifs_file_list_lock);
 270         list_add(&pCifsFile->tlist, &(tlink_tcon(tlink)->openFileList));
 271         /* if readable file instance put first in list*/
 272         if (file->f_mode & FMODE_READ)
 273                 list_add(&pCifsFile->flist, &pCifsInode->openFileList);
 274         else
 275                 list_add_tail(&pCifsFile->flist, &pCifsInode->openFileList);
 276         spin_unlock(&cifs_file_list_lock);
 277
 278         cifs_set_oplock_level(pCifsInode, oplock);
 279         pCifsInode->can_cache_brlcks = pCifsInode->clientCanCacheAll;
 280
 281         file->private_data = pCifsFile;
 282         return pCifsFile;
 283 }
 284
 285 static void cifs_del_lock_waiters(struct cifsLockInfo *lock);
 286
 287 struct cifsFileInfo *
 288 cifsFileInfo_get(struct cifsFileInfo *cifs_file)
 289 {
 290         spin_lock(&cifs_file_list_lock);
 291         cifsFileInfo_get_locked(cifs_file);
 292         spin_unlock(&cifs_file_list_lock);
 293         return cifs_file;
 294 }
 295
 296 /*
 297  * Release a reference on the file private data. This may involve closing
 298  * the filehandle out on the server. Must be called without holding
 299  * cifs_file_list_lock.
 300  */
 301 void cifsFileInfo_put(struct cifsFileInfo *cifs_file)
 302 {
 303         struct inode *inode = cifs_file->dentry->d_inode;
 304         struct cifs_tcon *tcon = tlink_tcon(cifs_file->tlink);
 305         struct cifsInodeInfo *cifsi = CIFS_I(inode);
 306         struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
 307         struct cifsLockInfo *li, *tmp;
 308
 309         spin_lock(&cifs_file_list_lock);
 310         if (--cifs_file->count > 0) {
 311                 spin_unlock(&cifs_file_list_lock);
 312                 return;
 313         }
 314
 315         /* remove it from the lists */
 316         list_del(&cifs_file->flist);
 317         list_del(&cifs_file->tlist);
 318
 319         if (list_empty(&cifsi->openFileList)) {
 320                 cFYI(1, "closing last open instance for inode %p",
 321                         cifs_file->dentry->d_inode);
 322
 323                 /* in strict cache mode we need invalidate mapping on the last
 324                    close  because it may cause a error when we open this file
 325                    again and get at least level II oplock */
 326                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_STRICT_IO)
 327                         CIFS_I(inode)->invalid_mapping = true;
 328
 329                 cifs_set_oplock_level(cifsi, 0);
 330         }
 331         spin_unlock(&cifs_file_list_lock);
 332
 333         cancel_work_sync(&cifs_file->oplock_break);
 334
 335         if (!tcon->need_reconnect && !cifs_file->invalidHandle) {
 336                 unsigned int xid;
 337                 int rc;
 338                 xid = get_xid();
 339                 rc = CIFSSMBClose(xid, tcon, cifs_file->netfid);
 340                 free_xid(xid);
 341         }
 342
 343         /* Delete any outstanding lock records. We'll lose them when the file
 344          * is closed anyway.
 345          */
 346         mutex_lock(&cifsi->lock_mutex);
 347         list_for_each_entry_safe(li, tmp, &cifs_file->llist, llist) {
 348                 list_del(&li->llist);
 349                 cifs_del_lock_waiters(li);
 350                 kfree(li);
 351         }
 352         mutex_unlock(&cifsi->lock_mutex);
 353
 354         cifs_put_tlink(cifs_file->tlink);
 355         dput(cifs_file->dentry);
 356         kfree(cifs_file);
 357 }
 358
 359 int cifs_open(struct inode *inode, struct file *file)
 360 {
 361         int rc = -EACCES;
 362         unsigned int xid;
 363         __u32 oplock;
 364         struct cifs_sb_info *cifs_sb;
 365         struct cifs_tcon *tcon;
 366         struct tcon_link *tlink;
 367         struct cifsFileInfo *pCifsFile = NULL;
 368         char *full_path = NULL;
 369         bool posix_open_ok = false;
 370         __u16 netfid;
 371
 372         xid = get_xid();
 373
 374         cifs_sb = CIFS_SB(inode->i_sb);
 375         tlink = cifs_sb_tlink(cifs_sb);
 376         if (IS_ERR(tlink)) {
 377                 free_xid(xid);
 378                 return PTR_ERR(tlink);
 379         }
 380         tcon = tlink_tcon(tlink);
 381
 382         full_path = build_path_from_dentry(file->f_path.dentry);
 383         if (full_path == NULL) {
 384                 rc = -ENOMEM;
 385                 goto out;
 386         }
 387
 388         cFYI(1, "inode = 0x%p file flags are 0x%x for %s",
 389                  inode, file->f_flags, full_path);
 390
 391         if (tcon->ses->server->oplocks)
 392                 oplock = REQ_OPLOCK;
 393         else
 394                 oplock = 0;
 395
 396         if (!tcon->broken_posix_open && tcon->unix_ext &&
 397             cap_unix(tcon->ses) && (CIFS_UNIX_POSIX_PATH_OPS_CAP &
 398                                 le64_to_cpu(tcon->fsUnixInfo.Capability))) {
 399                 /* can not refresh inode info since size could be stale */
 400                 rc = cifs_posix_open(full_path, &inode, inode->i_sb,
 401                                 cifs_sb->mnt_file_mode /* ignored */,
 402                                 file->f_flags, &oplock, &netfid, xid);
 403                 if (rc == 0) {
 404                         cFYI(1, "posix open succeeded");
 405                         posix_open_ok = true;
 406                 } else if ((rc == -EINVAL) || (rc == -EOPNOTSUPP)) {
 407                         if (tcon->ses->serverNOS)
 408                                 cERROR(1, "server %s of type %s returned"
 409                                            " unexpected error on SMB posix open"
 410                                            ", disabling posix open support."
 411                                            " Check if server update available.",
 412                                            tcon->ses->serverName,
 413                                            tcon->ses->serverNOS);
 414                         tcon->broken_posix_open = true;
 415                 } else if ((rc != -EIO) && (rc != -EREMOTE) &&
 416                          (rc != -EOPNOTSUPP)) /* path not found or net err */
 417                         goto out;
 418                 /* else fallthrough to retry open the old way on network i/o
 419                    or DFS errors */
 420         }
 421
 422         if (!posix_open_ok) {
 423                 rc = cifs_nt_open(full_path, inode, cifs_sb, tcon,
 424                                   file->f_flags, &oplock, &netfid, xid);
 425                 if (rc)
 426                         goto out;
 427         }
 428
 429         pCifsFile = cifs_new_fileinfo(netfid, file, tlink, oplock);
 430         if (pCifsFile == NULL) {
 431                 CIFSSMBClose(xid, tcon, netfid);
 432                 rc = -ENOMEM;
 433                 goto out;
 434         }
 435
 436         cifs_fscache_set_inode_cookie(inode, file);
 437
 438         if ((oplock & CIFS_CREATE_ACTION) && !posix_open_ok && tcon->unix_ext) {
 439                 /* time to set mode which we can not set earlier due to
 440                    problems creating new read-only files */
 441                 struct cifs_unix_set_info_args args = {
 442                         .mode   = inode->i_mode,
 443                         .uid    = NO_CHANGE_64,
 444                         .gid    = NO_CHANGE_64,
 445                         .ctime  = NO_CHANGE_64,
 446                         .atime  = NO_CHANGE_64,
 447                         .mtime  = NO_CHANGE_64,
 448                         .device = 0,
 449                 };
 450                 CIFSSMBUnixSetFileInfo(xid, tcon, &args, netfid,
 451                                         pCifsFile->pid);
 452         }
 453
 454 out:
 455         kfree(full_path);
 456         free_xid(xid);
 457         cifs_put_tlink(tlink);
 458         return rc;
 459 }
 460
 461 /* Try to reacquire byte range locks that were released when session */
 462 /* to server was lost */
 463 static int cifs_relock_file(struct cifsFileInfo *cifsFile)
 464 {
 465         int rc = 0;
 466
 467 /* BB list all locks open on this file and relock */
 468
 469         return rc;
 470 }
 471
 472 static int cifs_reopen_file(struct cifsFileInfo *pCifsFile, bool can_flush)
 473 {
 474         int rc = -EACCES;
 475         unsigned int xid;
 476         __u32 oplock;
 477         struct cifs_sb_info *cifs_sb;
 478         struct cifs_tcon *tcon;
 479         struct cifsInodeInfo *pCifsInode;
 480         struct inode *inode;
 481         char *full_path = NULL;
 482         int desiredAccess;
 483         int disposition = FILE_OPEN;
 484         int create_options = CREATE_NOT_DIR;
 485         __u16 netfid;
 486
 487         xid = get_xid();
 488         mutex_lock(&pCifsFile->fh_mutex);
 489         if (!pCifsFile->invalidHandle) {
 490                 mutex_unlock(&pCifsFile->fh_mutex);
 491                 rc = 0;
 492                 free_xid(xid);
 493                 return rc;
 494         }
 495
 496         inode = pCifsFile->dentry->d_inode;
 497         cifs_sb = CIFS_SB(inode->i_sb);
 498         tcon = tlink_tcon(pCifsFile->tlink);
 499
 500 /* can not grab rename sem here because various ops, including
 501    those that already have the rename sem can end up causing writepage
 502    to get called and if the server was down that means we end up here,
 503    and we can never tell if the caller already has the rename_sem */
 504         full_path = build_path_from_dentry(pCifsFile->dentry);
 505         if (full_path == NULL) {
 506                 rc = -ENOMEM;
 507                 mutex_unlock(&pCifsFile->fh_mutex);
 508                 free_xid(xid);
 509                 return rc;
 510         }
 511
 512         cFYI(1, "inode = 0x%p file flags 0x%x for %s",
 513                  inode, pCifsFile->f_flags, full_path);
 514
 515         if (tcon->ses->server->oplocks)
 516                 oplock = REQ_OPLOCK;
 517         else
 518                 oplock = 0;
 519
 520         if (tcon->unix_ext && cap_unix(tcon->ses) &&
 521             (CIFS_UNIX_POSIX_PATH_OPS_CAP &
 522                                 le64_to_cpu(tcon->fsUnixInfo.Capability))) {
 523                 /*
 524                  * O_CREAT, O_EXCL and O_TRUNC already had their effect on the
 525                  * original open. Must mask them off for a reopen.
 526                  */
 527                 unsigned int oflags = pCifsFile->f_flags &
 528                                                 ~(O_CREAT | O_EXCL | O_TRUNC);
 529
 530                 rc = cifs_posix_open(full_path, NULL, inode->i_sb,
 531                                 cifs_sb->mnt_file_mode /* ignored */,
 532                                 oflags, &oplock, &netfid, xid);
 533                 if (rc == 0) {
 534                         cFYI(1, "posix reopen succeeded");
 535                         goto reopen_success;
 536                 }
 537                 /* fallthrough to retry open the old way on errors, especially
 538                    in the reconnect path it is important to retry hard */
 539         }
 540
 541         desiredAccess = cifs_convert_flags(pCifsFile->f_flags);
 542
 543         if (backup_cred(cifs_sb))
 544                 create_options |= CREATE_OPEN_BACKUP_INTENT;
 545
 546         /* Can not refresh inode by passing in file_info buf to be returned
 547            by SMBOpen and then calling get_inode_info with returned buf
 548            since file might have write behind data that needs to be flushed
 549            and server version of file size can be stale. If we knew for sure
 550            that inode was not dirty locally we could do this */
 551
 552         rc = CIFSSMBOpen(xid, tcon, full_path, disposition, desiredAccess,
 553                          create_options, &netfid, &oplock, NULL,
 554                          cifs_sb->local_nls, cifs_sb->mnt_cifs_flags &
 555                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
 556         if (rc) {
 557                 mutex_unlock(&pCifsFile->fh_mutex);
 558                 cFYI(1, "cifs_open returned 0x%x", rc);
 559                 cFYI(1, "oplock: %d", oplock);
 560                 goto reopen_error_exit;
 561         }
 562
 563 reopen_success:
 564         pCifsFile->netfid = netfid;
 565         pCifsFile->invalidHandle = false;
 566         mutex_unlock(&pCifsFile->fh_mutex);
 567         pCifsInode = CIFS_I(inode);
 568
 569         if (can_flush) {
 570                 rc = filemap_write_and_wait(inode->i_mapping);
 571                 mapping_set_error(inode->i_mapping, rc);
 572
 573                 if (tcon->unix_ext)
 574                         rc = cifs_get_inode_info_unix(&inode,
 575                                 full_path, inode->i_sb, xid);
 576                 else
 577                         rc = cifs_get_inode_info(&inode,
 578                                 full_path, NULL, inode->i_sb,
 579                                 xid, NULL);
 580         } /* else we are writing out data to server already
 581              and could deadlock if we tried to flush data, and
 582              since we do not know if we have data that would
 583              invalidate the current end of file on the server
 584              we can not go to the server to get the new inod
 585              info */
 586
 587         cifs_set_oplock_level(pCifsInode, oplock);
 588
 589         cifs_relock_file(pCifsFile);
 590
 591 reopen_error_exit:
 592         kfree(full_path);
 593         free_xid(xid);
 594         return rc;
 595 }
 596
 597 int cifs_close(struct inode *inode, struct file *file)
 598 {
 599         if (file->private_data != NULL) {
 600                 cifsFileInfo_put(file->private_data);
 601                 file->private_data = NULL;
 602         }
 603
 604         /* return code from the ->release op is always ignored */
 605         return 0;
 606 }
 607
 608 int cifs_closedir(struct inode *inode, struct file *file)
 609 {
 610         int rc = 0;
 611         unsigned int xid;
 612         struct cifsFileInfo *pCFileStruct = file->private_data;
 613         char *ptmp;
 614
 615         cFYI(1, "Closedir inode = 0x%p", inode);
 616
 617         xid = get_xid();
 618
 619         if (pCFileStruct) {
 620                 struct cifs_tcon *pTcon = tlink_tcon(pCFileStruct->tlink);
 621
 622                 cFYI(1, "Freeing private data in close dir");
 623                 spin_lock(&cifs_file_list_lock);
 624                 if (!pCFileStruct->srch_inf.endOfSearch &&
 625                     !pCFileStruct->invalidHandle) {
 626                         pCFileStruct->invalidHandle = true;
 627                         spin_unlock(&cifs_file_list_lock);
 628                         rc = CIFSFindClose(xid, pTcon, pCFileStruct->netfid);
 629                         cFYI(1, "Closing uncompleted readdir with rc %d",
 630                                  rc);
 631                         /* not much we can do if it fails anyway, ignore rc */
 632                         rc = 0;
 633                 } else
 634                         spin_unlock(&cifs_file_list_lock);
 635                 ptmp = pCFileStruct->srch_inf.ntwrk_buf_start;
 636                 if (ptmp) {
 637                         cFYI(1, "closedir free smb buf in srch struct");
 638                         pCFileStruct->srch_inf.ntwrk_buf_start = NULL;
 639                         if (pCFileStruct->srch_inf.smallBuf)
 640                                 cifs_small_buf_release(ptmp);
 641                         else
 642                                 cifs_buf_release(ptmp);
 643                 }
 644                 cifs_put_tlink(pCFileStruct->tlink);
 645                 kfree(file->private_data);
 646                 file->private_data = NULL;
 647         }
 648         /* BB can we lock the filestruct while this is going on? */
 649         free_xid(xid);
 650         return rc;
 651 }
 652
 653 static struct cifsLockInfo *
 654 cifs_lock_init(__u64 offset, __u64 length, __u8 type)
 655 {
 656         struct cifsLockInfo *lock =
 657                 kmalloc(sizeof(struct cifsLockInfo), GFP_KERNEL);
 658         if (!lock)
 659                 return lock;
 660         lock->offset = offset;
 661         lock->length = length;
 662         lock->type = type;
 663         lock->pid = current->tgid;
 664         INIT_LIST_HEAD(&lock->blist);
 665         init_waitqueue_head(&lock->block_q);
 666         return lock;
 667 }
 668
 669 static void
 670 cifs_del_lock_waiters(struct cifsLockInfo *lock)
 671 {
 672         struct cifsLockInfo *li, *tmp;
 673         list_for_each_entry_safe(li, tmp, &lock->blist, blist) {
 674                 list_del_init(&li->blist);
 675                 wake_up(&li->block_q);
 676         }
 677 }
 678
 679 static bool
 680 cifs_find_fid_lock_conflict(struct cifsFileInfo *cfile, __u64 offset,
 681                             __u64 length, __u8 type, struct cifsFileInfo *cur,
 682                             struct cifsLockInfo **conf_lock)
 683 {
 684         struct cifsLockInfo *li;
 685         struct TCP_Server_Info *server = tlink_tcon(cfile->tlink)->ses->server;
 686
 687         list_for_each_entry(li, &cfile->llist, llist) {
 688                 if (offset + length <= li->offset ||
 689                     offset >= li->offset + li->length)
 690                         continue;
 691                 else if ((type & server->vals->shared_lock_type) &&
 692                          ((server->ops->compare_fids(cur, cfile) &&
 693                            current->tgid == li->pid) || type == li->type))
 694                         continue;
 695                 else {
 696                         *conf_lock = li;
 697                         return true;
 698                 }
 699         }
 700         return false;
 701 }
 702
 703 static bool
 704 cifs_find_lock_conflict(struct cifsFileInfo *cfile, __u64 offset, __u64 length,
 705                         __u8 type, struct cifsLockInfo **conf_lock)
 706 {
 707         bool rc = false;
 708         struct cifsFileInfo *fid, *tmp;
 709         struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
 710
 711         spin_lock(&cifs_file_list_lock);
 712         list_for_each_entry_safe(fid, tmp, &cinode->openFileList, flist) {
 713                 rc = cifs_find_fid_lock_conflict(fid, offset, length, type,
 714                                                  cfile, conf_lock);
 715                 if (rc)
 716                         break;
 717         }
 718         spin_unlock(&cifs_file_list_lock);
 719
 720         return rc;
 721 }
 722
 723 /*
 724  * Check if there is another lock that prevents us to set the lock (mandatory
 725  * style). If such a lock exists, update the flock structure with its
 726  * properties. Otherwise, set the flock type to F_UNLCK if we can cache brlocks
 727  * or leave it the same if we can't. Returns 0 if we don't need to request to
 728  * the server or 1 otherwise.
 729  */
 730 static int
 731 cifs_lock_test(struct cifsFileInfo *cfile, __u64 offset, __u64 length,
 732                __u8 type, struct file_lock *flock)
 733 {
 734         int rc = 0;
 735         struct cifsLockInfo *conf_lock;
 736         struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
 737         struct TCP_Server_Info *server = tlink_tcon(cfile->tlink)->ses->server;
 738         bool exist;
 739
 740         mutex_lock(&cinode->lock_mutex);
 741
 742         exist = cifs_find_lock_conflict(cfile, offset, length, type,
 743                                         &conf_lock);
 744         if (exist) {
 745                 flock->fl_start = conf_lock->offset;
 746                 flock->fl_end = conf_lock->offset + conf_lock->length - 1;
 747                 flock->fl_pid = conf_lock->pid;
 748                 if (conf_lock->type & server->vals->shared_lock_type)
 749                         flock->fl_type = F_RDLCK;
 750                 else
 751                         flock->fl_type = F_WRLCK;
 752         } else if (!cinode->can_cache_brlcks)
 753                 rc = 1;
 754         else
 755                 flock->fl_type = F_UNLCK;
 756
 757         mutex_unlock(&cinode->lock_mutex);
 758         return rc;
 759 }
 760
 761 static void
 762 cifs_lock_add(struct cifsFileInfo *cfile, struct cifsLockInfo *lock)
 763 {
 764         struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
 765         mutex_lock(&cinode->lock_mutex);
 766         list_add_tail(&lock->llist, &cfile->llist);
 767         mutex_unlock(&cinode->lock_mutex);
 768 }
 769
 770 /*
 771  * Set the byte-range lock (mandatory style). Returns:
 772  * 1) 0, if we set the lock and don't need to request to the server;
 773  * 2) 1, if no locks prevent us but we need to request to the server;
 774  * 3) -EACCESS, if there is a lock that prevents us and wait is false.
 775  */
 776 static int
 777 cifs_lock_add_if(struct cifsFileInfo *cfile, struct cifsLockInfo *lock,
 778                  bool wait)
 779 {
 780         struct cifsLockInfo *conf_lock;
 781         struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
 782         bool exist;
 783         int rc = 0;
 784
 785 try_again:
 786         exist = false;
 787         mutex_lock(&cinode->lock_mutex);
 788
 789         exist = cifs_find_lock_conflict(cfile, lock->offset, lock->length,
 790                                         lock->type, &conf_lock);
 791         if (!exist && cinode->can_cache_brlcks) {
 792                 list_add_tail(&lock->llist, &cfile->llist);
 793                 mutex_unlock(&cinode->lock_mutex);
 794                 return rc;
 795         }
 796
 797         if (!exist)
 798                 rc = 1;
 799         else if (!wait)
 800                 rc = -EACCES;
 801         else {
 802                 list_add_tail(&lock->blist, &conf_lock->blist);
 803                 mutex_unlock(&cinode->lock_mutex);
 804                 rc = wait_event_interruptible(lock->block_q,
 805                                         (lock->blist.prev == &lock->blist) &&
 806                                         (lock->blist.next == &lock->blist));
 807                 if (!rc)
 808                         goto try_again;
 809                 mutex_lock(&cinode->lock_mutex);
 810                 list_del_init(&lock->blist);
 811         }
 812
 813         mutex_unlock(&cinode->lock_mutex);
 814         return rc;
 815 }
 816
 817 /*
 818  * Check if there is another lock that prevents us to set the lock (posix
 819  * style). If such a lock exists, update the flock structure with its
 820  * properties. Otherwise, set the flock type to F_UNLCK if we can cache brlocks
 821  * or leave it the same if we can't. Returns 0 if we don't need to request to
 822  * the server or 1 otherwise.
 823  */
 824 static int
 825 cifs_posix_lock_test(struct file *file, struct file_lock *flock)
 826 {
 827         int rc = 0;
 828         struct cifsInodeInfo *cinode = CIFS_I(file->f_path.dentry->d_inode);
 829         unsigned char saved_type = flock->fl_type;
 830
 831         if ((flock->fl_flags & FL_POSIX) == 0)
 832                 return 1;
 833
 834         mutex_lock(&cinode->lock_mutex);
 835         posix_test_lock(file, flock);
 836
 837         if (flock->fl_type == F_UNLCK && !cinode->can_cache_brlcks) {
 838                 flock->fl_type = saved_type;
 839                 rc = 1;
 840         }
 841
 842         mutex_unlock(&cinode->lock_mutex);
 843         return rc;
 844 }
 845
 846 /*
 847  * Set the byte-range lock (posix style). Returns:
 848  * 1) 0, if we set the lock and don't need to request to the server;
 849  * 2) 1, if we need to request to the server;
 850  * 3) <0, if the error occurs while setting the lock.
 851  */
 852 static int
 853 cifs_posix_lock_set(struct file *file, struct file_lock *flock)
 854 {
 855         struct cifsInodeInfo *cinode = CIFS_I(file->f_path.dentry->d_inode);
 856         int rc = 1;
 857
 858         if ((flock->fl_flags & FL_POSIX) == 0)
 859                 return rc;
 860
 861 try_again:
 862         mutex_lock(&cinode->lock_mutex);
 863         if (!cinode->can_cache_brlcks) {
 864                 mutex_unlock(&cinode->lock_mutex);
 865                 return rc;
 866         }
 867
 868         rc = posix_lock_file(file, flock, NULL);
 869         mutex_unlock(&cinode->lock_mutex);
 870         if (rc == FILE_LOCK_DEFERRED) {
 871                 rc = wait_event_interruptible(flock->fl_wait, !flock->fl_next);
 872                 if (!rc)
 873                         goto try_again;
 874                 locks_delete_block(flock);
 875         }
 876         return rc;
 877 }
 878
 879 static int
 880 cifs_push_mandatory_locks(struct cifsFileInfo *cfile)
 881 {
 882         unsigned int xid;
 883         int rc = 0, stored_rc;
 884         struct cifsLockInfo *li, *tmp;
 885         struct cifs_tcon *tcon;
 886         struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
 887         unsigned int num, max_num, max_buf;
 888         LOCKING_ANDX_RANGE *buf, *cur;
 889         int types[] = {LOCKING_ANDX_LARGE_FILES,
 890                        LOCKING_ANDX_SHARED_LOCK | LOCKING_ANDX_LARGE_FILES};
 891         int i;
 892
 893         xid = get_xid();
 894         tcon = tlink_tcon(cfile->tlink);
 895
 896         mutex_lock(&cinode->lock_mutex);
 897         if (!cinode->can_cache_brlcks) {
 898                 mutex_unlock(&cinode->lock_mutex);
 899                 free_xid(xid);
 900                 return rc;
 901         }
 902
 903         /*
 904          * Accessing maxBuf is racy with cifs_reconnect - need to store value
 905          * and check it for zero before using.
 906          */
 907         max_buf = tcon->ses->server->maxBuf;
 908         if (!max_buf) {
 909                 mutex_unlock(&cinode->lock_mutex);
 910                 free_xid(xid);
 911                 return -EINVAL;
 912         }
 913
 914         max_num = (max_buf - sizeof(struct smb_hdr)) /
 915                                                 sizeof(LOCKING_ANDX_RANGE);
 916         buf = kzalloc(max_num * sizeof(LOCKING_ANDX_RANGE), GFP_KERNEL);
 917         if (!buf) {
 918                 mutex_unlock(&cinode->lock_mutex);
 919                 free_xid(xid);
 920                 return rc;
 921         }
 922
 923         for (i = 0; i < 2; i++) {
 924                 cur = buf;
 925                 num = 0;
 926                 list_for_each_entry_safe(li, tmp, &cfile->llist, llist) {
 927                         if (li->type != types[i])
 928                                 continue;
 929                         cur->Pid = cpu_to_le16(li->pid);
 930                         cur->LengthLow = cpu_to_le32((u32)li->length);
 931                         cur->LengthHigh = cpu_to_le32((u32)(li->length>>32));
 932                         cur->OffsetLow = cpu_to_le32((u32)li->offset);
 933                         cur->OffsetHigh = cpu_to_le32((u32)(li->offset>>32));
 934                         if (++num == max_num) {
 935                                 stored_rc = cifs_lockv(xid, tcon, cfile->netfid,
 936                                                        (__u8)li->type, 0, num,
 937                                                        buf);
 938                                 if (stored_rc)
 939                                         rc = stored_rc;
 940                                 cur = buf;
 941                                 num = 0;
 942                         } else
 943                                 cur++;
 944                 }
 945
 946                 if (num) {
 947                         stored_rc = cifs_lockv(xid, tcon, cfile->netfid,
 948                                                (__u8)types[i], 0, num, buf);
 949                         if (stored_rc)
 950                                 rc = stored_rc;
 951                 }
 952         }
 953
 954         cinode->can_cache_brlcks = false;
 955         mutex_unlock(&cinode->lock_mutex);
 956
 957         kfree(buf);
 958         free_xid(xid);
 959         return rc;
 960 }
 961
 962 /* copied from fs/locks.c with a name change */
 963 #define cifs_for_each_lock(inode, lockp) \
 964         for (lockp = &inode->i_flock; *lockp != NULL; \
 965              lockp = &(*lockp)->fl_next)
 966
 967 struct lock_to_push {
 968         struct list_head llist;
 969         __u64 offset;
 970         __u64 length;
 971         __u32 pid;
 972         __u16 netfid;
 973         __u8 type;
 974 };
 975
 976 static int
 977 cifs_push_posix_locks(struct cifsFileInfo *cfile)
 978 {
 979         struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
 980         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
 981         struct file_lock *flock, **before;
 982         unsigned int count = 0, i = 0;
 983         int rc = 0, xid, type;
 984         struct list_head locks_to_send, *el;
 985         struct lock_to_push *lck, *tmp;
 986         __u64 length;
 987
 988         xid = get_xid();
 989
 990         mutex_lock(&cinode->lock_mutex);
 991         if (!cinode->can_cache_brlcks) {
 992                 mutex_unlock(&cinode->lock_mutex);
 993                 free_xid(xid);
 994                 return rc;
 995         }
 996
 997         lock_flocks();
 998         cifs_for_each_lock(cfile->dentry->d_inode, before) {
 999                 if ((*before)->fl_flags & FL_POSIX)
1000                         count++;
1001         }
1002         unlock_flocks();
1003
1004         INIT_LIST_HEAD(&locks_to_send);
1005
1006         /*
1007          * Allocating count locks is enough because no FL_POSIX locks can be
1008          * added to the list while we are holding cinode->lock_mutex that
1009          * protects locking operations of this inode.
1010          */
1011         for (; i < count; i++) {
1012                 lck = kmalloc(sizeof(struct lock_to_push), GFP_KERNEL);
1013                 if (!lck) {
1014                         rc = -ENOMEM;
1015                         goto err_out;
1016                 }
1017                 list_add_tail(&lck->llist, &locks_to_send);
1018         }
1019
1020         el = locks_to_send.next;
1021         lock_flocks();
1022         cifs_for_each_lock(cfile->dentry->d_inode, before) {
1023                 flock = *before;
1024                 if ((flock->fl_flags & FL_POSIX) == 0)
1025                         continue;
1026                 if (el == &locks_to_send) {
1027                         /*
1028                          * The list ended. We don't have enough allocated
1029                          * structures - something is really wrong.
1030                          */
1031                         cERROR(1, "Can't push all brlocks!");
1032                         break;
1033                 }
1034                 length = 1 + flock->fl_end - flock->fl_start;
1035                 if (flock->fl_type == F_RDLCK || flock->fl_type == F_SHLCK)
1036                         type = CIFS_RDLCK;
1037                 else
1038                         type = CIFS_WRLCK;
1039                 lck = list_entry(el, struct lock_to_push, llist);
1040                 lck->pid = flock->fl_pid;
1041                 lck->netfid = cfile->netfid;
1042                 lck->length = length;
1043                 lck->type = type;
1044                 lck->offset = flock->fl_start;
1045                 el = el->next;
1046         }
1047         unlock_flocks();
1048
1049         list_for_each_entry_safe(lck, tmp, &locks_to_send, llist) {
1050                 int stored_rc;
1051
1052                 stored_rc = CIFSSMBPosixLock(xid, tcon, lck->netfid, lck->pid,
1053                                              lck->offset, lck->length, NULL,
1054                                              lck->type, 0);
1055                 if (stored_rc)
1056                         rc = stored_rc;
1057                 list_del(&lck->llist);
1058                 kfree(lck);
1059         }
1060
1061 out:
1062         cinode->can_cache_brlcks = false;
1063         mutex_unlock(&cinode->lock_mutex);
1064
1065         free_xid(xid);
1066         return rc;
1067 err_out:
1068         list_for_each_entry_safe(lck, tmp, &locks_to_send, llist) {
1069                 list_del(&lck->llist);
1070                 kfree(lck);
1071         }
1072         goto out;
1073 }
1074
1075 static int
1076 cifs_push_locks(struct cifsFileInfo *cfile)
1077 {
1078         struct cifs_sb_info *cifs_sb = CIFS_SB(cfile->dentry->d_sb);
1079         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1080
1081         if (cap_unix(tcon->ses) &&
1082             (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
1083             ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
1084                 return cifs_push_posix_locks(cfile);
1085
1086         return cifs_push_mandatory_locks(cfile);
1087 }
1088
1089 static void
1090 cifs_read_flock(struct file_lock *flock, __u32 *type, int *lock, int *unlock,
1091                 bool *wait_flag, struct TCP_Server_Info *server)
1092 {
1093         if (flock->fl_flags & FL_POSIX)
1094                 cFYI(1, "Posix");
1095         if (flock->fl_flags & FL_FLOCK)
1096                 cFYI(1, "Flock");
1097         if (flock->fl_flags & FL_SLEEP) {
1098                 cFYI(1, "Blocking lock");
1099                 *wait_flag = true;
1100         }
1101         if (flock->fl_flags & FL_ACCESS)
1102                 cFYI(1, "Process suspended by mandatory locking - "
1103                         "not implemented yet");
1104         if (flock->fl_flags & FL_LEASE)
1105                 cFYI(1, "Lease on file - not implemented yet");
1106         if (flock->fl_flags &
1107             (~(FL_POSIX | FL_FLOCK | FL_SLEEP | FL_ACCESS | FL_LEASE)))
1108                 cFYI(1, "Unknown lock flags 0x%x", flock->fl_flags);
1109
1110         *type = server->vals->large_lock_type;
1111         if (flock->fl_type == F_WRLCK) {
1112                 cFYI(1, "F_WRLCK ");
1113                 *type |= server->vals->exclusive_lock_type;
1114                 *lock = 1;
1115         } else if (flock->fl_type == F_UNLCK) {
1116                 cFYI(1, "F_UNLCK");
1117                 *type |= server->vals->unlock_lock_type;
1118                 *unlock = 1;
1119                 /* Check if unlock includes more than one lock range */
1120         } else if (flock->fl_type == F_RDLCK) {
1121                 cFYI(1, "F_RDLCK");
1122                 *type |= server->vals->shared_lock_type;
1123                 *lock = 1;
1124         } else if (flock->fl_type == F_EXLCK) {
1125                 cFYI(1, "F_EXLCK");
1126                 *type |= server->vals->exclusive_lock_type;
1127                 *lock = 1;
1128         } else if (flock->fl_type == F_SHLCK) {
1129                 cFYI(1, "F_SHLCK");
1130                 *type |= server->vals->shared_lock_type;
1131                 *lock = 1;
1132         } else
1133                 cFYI(1, "Unknown type of lock");
1134 }
1135
1136 static int
1137 cifs_mandatory_lock(unsigned int xid, struct cifsFileInfo *cfile, __u64 offset,
1138                     __u64 length, __u32 type, int lock, int unlock, bool wait)
1139 {
1140         return CIFSSMBLock(xid, tlink_tcon(cfile->tlink), cfile->netfid,
1141                            current->tgid, length, offset, unlock, lock,
1142                            (__u8)type, wait, 0);
1143 }
1144
1145 static int
1146 cifs_getlk(struct file *file, struct file_lock *flock, __u32 type,
1147            bool wait_flag, bool posix_lck, unsigned int xid)
1148 {
1149         int rc = 0;
1150         __u64 length = 1 + flock->fl_end - flock->fl_start;
1151         struct cifsFileInfo *cfile = (struct cifsFileInfo *)file->private_data;
1152         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1153         struct TCP_Server_Info *server = tcon->ses->server;
1154         __u16 netfid = cfile->netfid;
1155
1156         if (posix_lck) {
1157                 int posix_lock_type;
1158
1159                 rc = cifs_posix_lock_test(file, flock);
1160                 if (!rc)
1161                         return rc;
1162
1163                 if (type & server->vals->shared_lock_type)
1164                         posix_lock_type = CIFS_RDLCK;
1165                 else
1166                         posix_lock_type = CIFS_WRLCK;
1167                 rc = CIFSSMBPosixLock(xid, tcon, netfid, current->tgid,
1168                                       flock->fl_start, length, flock,
1169                                       posix_lock_type, wait_flag);
1170                 return rc;
1171         }
1172
1173         rc = cifs_lock_test(cfile, flock->fl_start, length, type, flock);
1174         if (!rc)
1175                 return rc;
1176
1177         /* BB we could chain these into one lock request BB */
1178         rc = cifs_mandatory_lock(xid, cfile, flock->fl_start, length, type,
1179                                  1, 0, false);
1180         if (rc == 0) {
1181                 rc = cifs_mandatory_lock(xid, cfile, flock->fl_start, length,
1182                                          type, 0, 1, false);
1183                 flock->fl_type = F_UNLCK;
1184                 if (rc != 0)
1185                         cERROR(1, "Error unlocking previously locked "
1186                                   "range %d during test of lock", rc);
1187                 return 0;
1188         }
1189
1190         if (type & server->vals->shared_lock_type) {
1191                 flock->fl_type = F_WRLCK;
1192                 return 0;
1193         }
1194
1195         rc = cifs_mandatory_lock(xid, cfile, flock->fl_start, length,
1196                                  type | server->vals->shared_lock_type, 1, 0,
1197                                  false);
1198         if (rc == 0) {
1199                 rc = cifs_mandatory_lock(xid, cfile, flock->fl_start, length,
1200                                          type | server->vals->shared_lock_type,
1201                                          0, 1, false);
1202                 flock->fl_type = F_RDLCK;
1203                 if (rc != 0)
1204                         cERROR(1, "Error unlocking previously locked "
1205                                   "range %d during test of lock", rc);
1206         } else
1207                 flock->fl_type = F_WRLCK;
1208
1209         return 0;
1210 }
1211
1212 static void
1213 cifs_move_llist(struct list_head *source, struct list_head *dest)
1214 {
1215         struct list_head *li, *tmp;
1216         list_for_each_safe(li, tmp, source)
1217                 list_move(li, dest);
1218 }
1219
1220 static void
1221 cifs_free_llist(struct list_head *llist)
1222 {
1223         struct cifsLockInfo *li, *tmp;
1224         list_for_each_entry_safe(li, tmp, llist, llist) {
1225                 cifs_del_lock_waiters(li);
1226                 list_del(&li->llist);
1227                 kfree(li);
1228         }
1229 }
1230
1231 static int
1232 cifs_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock,
1233                   unsigned int xid)
1234 {
1235         int rc = 0, stored_rc;
1236         int types[] = {LOCKING_ANDX_LARGE_FILES,
1237                        LOCKING_ANDX_SHARED_LOCK | LOCKING_ANDX_LARGE_FILES};
1238         unsigned int i;
1239         unsigned int max_num, num, max_buf;
1240         LOCKING_ANDX_RANGE *buf, *cur;
1241         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1242         struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
1243         struct cifsLockInfo *li, *tmp;
1244         __u64 length = 1 + flock->fl_end - flock->fl_start;
1245         struct list_head tmp_llist;
1246
1247         INIT_LIST_HEAD(&tmp_llist);
1248
1249         /*
1250          * Accessing maxBuf is racy with cifs_reconnect - need to store value
1251          * and check it for zero before using.
1252          */
1253         max_buf = tcon->ses->server->maxBuf;
1254         if (!max_buf)
1255                 return -EINVAL;
1256
1257         max_num = (max_buf - sizeof(struct smb_hdr)) /
1258                                                 sizeof(LOCKING_ANDX_RANGE);
1259         buf = kzalloc(max_num * sizeof(LOCKING_ANDX_RANGE), GFP_KERNEL);
1260         if (!buf)
1261                 return -ENOMEM;
1262
1263         mutex_lock(&cinode->lock_mutex);
1264         for (i = 0; i < 2; i++) {
1265                 cur = buf;
1266                 num = 0;
1267                 list_for_each_entry_safe(li, tmp, &cfile->llist, llist) {
1268                         if (flock->fl_start > li->offset ||
1269                             (flock->fl_start + length) <
1270                             (li->offset + li->length))
1271                                 continue;
1272                         if (current->tgid != li->pid)
1273                                 continue;
1274                         if (types[i] != li->type)
1275                                 continue;
1276                         if (cinode->can_cache_brlcks) {
1277                                 /*
1278                                  * We can cache brlock requests - simply remove
1279                                  * a lock from the file's list.
1280                                  */
1281                                 list_del(&li->llist);
1282                                 cifs_del_lock_waiters(li);
1283                                 kfree(li);
1284                                 continue;
1285                         }
1286                         cur->Pid = cpu_to_le16(li->pid);
1287                         cur->LengthLow = cpu_to_le32((u32)li->length);
1288                         cur->LengthHigh = cpu_to_le32((u32)(li->length>>32));
1289                         cur->OffsetLow = cpu_to_le32((u32)li->offset);
1290                         cur->OffsetHigh = cpu_to_le32((u32)(li->offset>>32));
1291                         /*
1292                          * We need to save a lock here to let us add it again to
1293                          * the file's list if the unlock range request fails on
1294                          * the server.
1295                          */
1296                         list_move(&li->llist, &tmp_llist);
1297                         if (++num == max_num) {
1298                                 stored_rc = cifs_lockv(xid, tcon, cfile->netfid,
1299                                                        li->type, num, 0, buf);
1300                                 if (stored_rc) {
1301                                         /*
1302                                          * We failed on the unlock range
1303                                          * request - add all locks from the tmp
1304                                          * list to the head of the file's list.
1305                                          */
1306                                         cifs_move_llist(&tmp_llist,
1307                                                         &cfile->llist);
1308                                         rc = stored_rc;
1309                                 } else
1310                                         /*
1311                                          * The unlock range request succeed -
1312                                          * free the tmp list.
1313                                          */
1314                                         cifs_free_llist(&tmp_llist);
1315                                 cur = buf;
1316                                 num = 0;
1317                         } else
1318                                 cur++;
1319                 }
1320                 if (num) {
1321                         stored_rc = cifs_lockv(xid, tcon, cfile->netfid,
1322                                                types[i], num, 0, buf);
1323                         if (stored_rc) {
1324                                 cifs_move_llist(&tmp_llist, &cfile->llist);
1325                                 rc = stored_rc;
1326                         } else
1327                                 cifs_free_llist(&tmp_llist);
1328                 }
1329         }
1330
1331         mutex_unlock(&cinode->lock_mutex);
1332         kfree(buf);
1333         return rc;
1334 }
1335
1336 static int
1337 cifs_setlk(struct file *file,  struct file_lock *flock, __u32 type,
1338            bool wait_flag, bool posix_lck, int lock, int unlock,
1339            unsigned int xid)
1340 {
1341         int rc = 0;
1342         __u64 length = 1 + flock->fl_end - flock->fl_start;
1343         struct cifsFileInfo *cfile = (struct cifsFileInfo *)file->private_data;
1344         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1345         struct TCP_Server_Info *server = tcon->ses->server;
1346         __u16 netfid = cfile->netfid;
1347
1348         if (posix_lck) {
1349                 int posix_lock_type;
1350
1351                 rc = cifs_posix_lock_set(file, flock);
1352                 if (!rc || rc < 0)
1353                         return rc;
1354
1355                 if (type & server->vals->shared_lock_type)
1356                         posix_lock_type = CIFS_RDLCK;
1357                 else
1358                         posix_lock_type = CIFS_WRLCK;
1359
1360                 if (unlock == 1)
1361                         posix_lock_type = CIFS_UNLCK;
1362
1363                 rc = CIFSSMBPosixLock(xid, tcon, netfid, current->tgid,
1364                                       flock->fl_start, length, NULL,
1365                                       posix_lock_type, wait_flag);
1366                 goto out;
1367         }
1368
1369         if (lock) {
1370                 struct cifsLockInfo *lock;
1371
1372                 lock = cifs_lock_init(flock->fl_start, length, type);
1373                 if (!lock)
1374                         return -ENOMEM;
1375
1376                 rc = cifs_lock_add_if(cfile, lock, wait_flag);
1377                 if (rc < 0)
1378                         kfree(lock);
1379                 if (rc <= 0)
1380                         goto out;
1381
1382                 rc = cifs_mandatory_lock(xid, cfile, flock->fl_start, length,
1383                                          type, 1, 0, wait_flag);
1384                 if (rc) {
1385                         kfree(lock);
1386                         goto out;
1387                 }
1388
1389                 cifs_lock_add(cfile, lock);
1390         } else if (unlock)
1391                 rc = cifs_unlock_range(cfile, flock, xid);
1392
1393 out:
1394         if (flock->fl_flags & FL_POSIX)
1395                 posix_lock_file_wait(file, flock);
1396         return rc;
1397 }
1398
1399 int cifs_lock(struct file *file, int cmd, struct file_lock *flock)
1400 {
1401         int rc, xid;
1402         int lock = 0, unlock = 0;
1403         bool wait_flag = false;
1404         bool posix_lck = false;
1405         struct cifs_sb_info *cifs_sb;
1406         struct cifs_tcon *tcon;
1407         struct cifsInodeInfo *cinode;
1408         struct cifsFileInfo *cfile;
1409         __u16 netfid;
1410         __u32 type;
1411
1412         rc = -EACCES;
1413         xid = get_xid();
1414
1415         cFYI(1, "Lock parm: 0x%x flockflags: 0x%x flocktype: 0x%x start: %lld "
1416                 "end: %lld", cmd, flock->fl_flags, flock->fl_type,
1417                 flock->fl_start, flock->fl_end);
1418
1419         cfile = (struct cifsFileInfo *)file->private_data;
1420         tcon = tlink_tcon(cfile->tlink);
1421
1422         cifs_read_flock(flock, &type, &lock, &unlock, &wait_flag,
1423                         tcon->ses->server);
1424
1425         cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
1426         netfid = cfile->netfid;
1427         cinode = CIFS_I(file->f_path.dentry->d_inode);
1428
1429         if (cap_unix(tcon->ses) &&
1430             (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
1431             ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
1432                 posix_lck = true;
1433         /*
1434          * BB add code here to normalize offset and length to account for
1435          * negative length which we can not accept over the wire.
1436          */
1437         if (IS_GETLK(cmd)) {
1438                 rc = cifs_getlk(file, flock, type, wait_flag, posix_lck, xid);
1439                 free_xid(xid);
1440                 return rc;
1441         }
1442
1443         if (!lock && !unlock) {
1444                 /*
1445                  * if no lock or unlock then nothing to do since we do not
1446                  * know what it is
1447                  */
1448                 free_xid(xid);
1449                 return -EOPNOTSUPP;
1450         }
1451
1452         rc = cifs_setlk(file, flock, type, wait_flag, posix_lck, lock, unlock,
1453                         xid);
1454         free_xid(xid);
1455         return rc;
1456 }
1457
1458 /*
1459  * update the file size (if needed) after a write. Should be called with
1460  * the inode->i_lock held
1461  */
1462 void
1463 cifs_update_eof(struct cifsInodeInfo *cifsi, loff_t offset,
1464                       unsigned int bytes_written)
1465 {
1466         loff_t end_of_write = offset + bytes_written;
1467
1468         if (end_of_write > cifsi->server_eof)
1469                 cifsi->server_eof = end_of_write;
1470 }
1471
1472 static ssize_t cifs_write(struct cifsFileInfo *open_file, __u32 pid,
1473                           const char *write_data, size_t write_size,
1474                           loff_t *poffset)
1475 {
1476         int rc = 0;
1477         unsigned int bytes_written = 0;
1478         unsigned int total_written;
1479         struct cifs_sb_info *cifs_sb;
1480         struct cifs_tcon *pTcon;
1481         unsigned int xid;
1482         struct dentry *dentry = open_file->dentry;
1483         struct cifsInodeInfo *cifsi = CIFS_I(dentry->d_inode);
1484         struct cifs_io_parms io_parms;
1485
1486         cifs_sb = CIFS_SB(dentry->d_sb);
1487
1488         cFYI(1, "write %zd bytes to offset %lld of %s", write_size,
1489            *poffset, dentry->d_name.name);
1490
1491         pTcon = tlink_tcon(open_file->tlink);
1492
1493         xid = get_xid();
1494
1495         for (total_written = 0; write_size > total_written;
1496              total_written += bytes_written) {
1497                 rc = -EAGAIN;
1498                 while (rc == -EAGAIN) {
1499                         struct kvec iov[2];
1500                         unsigned int len;
1501
1502                         if (open_file->invalidHandle) {
1503                                 /* we could deadlock if we called
1504                                    filemap_fdatawait from here so tell
1505                                    reopen_file not to flush data to
1506                                    server now */
1507                                 rc = cifs_reopen_file(open_file, false);
1508                                 if (rc != 0)
1509                                         break;
1510                         }
1511
1512                         len = min((size_t)cifs_sb->wsize,
1513                                   write_size - total_written);
1514                         /* iov[0] is reserved for smb header */
1515                         iov[1].iov_base = (char *)write_data + total_written;
1516                         iov[1].iov_len = len;
1517                         io_parms.netfid = open_file->netfid;
1518                         io_parms.pid = pid;
1519                         io_parms.tcon = pTcon;
1520                         io_parms.offset = *poffset;
1521                         io_parms.length = len;
1522                         rc = CIFSSMBWrite2(xid, &io_parms, &bytes_written, iov,
1523                                            1, 0);
1524                 }
1525                 if (rc || (bytes_written == 0)) {
1526                         if (total_written)
1527                                 break;
1528                         else {
1529                                 free_xid(xid);
1530                                 return rc;
1531                         }
1532                 } else {
1533                         spin_lock(&dentry->d_inode->i_lock);
1534                         cifs_update_eof(cifsi, *poffset, bytes_written);
1535                         spin_unlock(&dentry->d_inode->i_lock);
1536                         *poffset += bytes_written;
1537                 }
1538         }
1539
1540         cifs_stats_bytes_written(pTcon, total_written);
1541
1542         if (total_written > 0) {
1543                 spin_lock(&dentry->d_inode->i_lock);
1544                 if (*poffset > dentry->d_inode->i_size)
1545                         i_size_write(dentry->d_inode, *poffset);
1546                 spin_unlock(&dentry->d_inode->i_lock);
1547         }
1548         mark_inode_dirty_sync(dentry->d_inode);
1549         free_xid(xid);
1550         return total_written;
1551 }
1552
1553 struct cifsFileInfo *find_readable_file(struct cifsInodeInfo *cifs_inode,
1554                                         bool fsuid_only)
1555 {
1556         struct cifsFileInfo *open_file = NULL;
1557         struct cifs_sb_info *cifs_sb = CIFS_SB(cifs_inode->vfs_inode.i_sb);
1558
1559         /* only filter by fsuid on multiuser mounts */
1560         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
1561                 fsuid_only = false;
1562
1563         spin_lock(&cifs_file_list_lock);
1564         /* we could simply get the first_list_entry since write-only entries
1565            are always at the end of the list but since the first entry might
1566            have a close pending, we go through the whole list */
1567         list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
1568                 if (fsuid_only && open_file->uid != current_fsuid())
1569                         continue;
1570                 if (OPEN_FMODE(open_file->f_flags) & FMODE_READ) {
1571                         if (!open_file->invalidHandle) {
1572                                 /* found a good file */
1573                                 /* lock it so it will not be closed on us */
1574                                 cifsFileInfo_get_locked(open_file);
1575                                 spin_unlock(&cifs_file_list_lock);
1576                                 return open_file;
1577                         } /* else might as well continue, and look for
1578                              another, or simply have the caller reopen it
1579                              again rather than trying to fix this handle */
1580                 } else /* write only file */
1581                         break; /* write only files are last so must be done */
1582         }
1583         spin_unlock(&cifs_file_list_lock);
1584         return NULL;
1585 }
1586
1587 struct cifsFileInfo *find_writable_file(struct cifsInodeInfo *cifs_inode,
1588                                         bool fsuid_only)
1589 {
1590         struct cifsFileInfo *open_file, *inv_file = NULL;
1591         struct cifs_sb_info *cifs_sb;
1592         bool any_available = false;
1593         int rc;
1594         unsigned int refind = 0;
1595
1596         /* Having a null inode here (because mapping->host was set to zero by
1597         the VFS or MM) should not happen but we had reports of on oops (due to
1598         it being zero) during stress testcases so we need to check for it */
1599
1600         if (cifs_inode == NULL) {
1601                 cERROR(1, "Null inode passed to cifs_writeable_file");
1602                 dump_stack();
1603                 return NULL;
1604         }
1605
1606         cifs_sb = CIFS_SB(cifs_inode->vfs_inode.i_sb);
1607
1608         /* only filter by fsuid on multiuser mounts */
1609         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
1610                 fsuid_only = false;
1611
1612         spin_lock(&cifs_file_list_lock);
1613 refind_writable:
1614         if (refind > MAX_REOPEN_ATT) {
1615                 spin_unlock(&cifs_file_list_lock);
1616                 return NULL;
1617         }
1618         list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
1619                 if (!any_available && open_file->pid != current->tgid)
1620                         continue;
1621                 if (fsuid_only && open_file->uid != current_fsuid())
1622                         continue;
1623                 if (OPEN_FMODE(open_file->f_flags) & FMODE_WRITE) {
1624                         if (!open_file->invalidHandle) {
1625                                 /* found a good writable file */
1626                                 cifsFileInfo_get_locked(open_file);
1627                                 spin_unlock(&cifs_file_list_lock);
1628                                 return open_file;
1629                         } else {
1630                                 if (!inv_file)
1631                                         inv_file = open_file;
1632                         }
1633                 }
1634         }
1635         /* couldn't find useable FH with same pid, try any available */
1636         if (!any_available) {
1637                 any_available = true;
1638                 goto refind_writable;
1639         }
1640
1641         if (inv_file) {
1642                 any_available = false;
1643                 cifsFileInfo_get_locked(inv_file);
1644         }
1645
1646         spin_unlock(&cifs_file_list_lock);
1647
1648         if (inv_file) {
1649                 rc = cifs_reopen_file(inv_file, false);
1650                 if (!rc)
1651                         return inv_file;
1652                 else {
1653                         spin_lock(&cifs_file_list_lock);
1654                         list_move_tail(&inv_file->flist,
1655                                         &cifs_inode->openFileList);
1656                         spin_unlock(&cifs_file_list_lock);
1657                         cifsFileInfo_put(inv_file);
1658                         spin_lock(&cifs_file_list_lock);
1659                         ++refind;
1660                         goto refind_writable;
1661                 }
1662         }
1663
1664         return NULL;
1665 }
1666
1667 static int cifs_partialpagewrite(struct page *page, unsigned from, unsigned to)
1668 {
1669         struct address_space *mapping = page->mapping;
1670         loff_t offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
1671         char *write_data;
1672         int rc = -EFAULT;
1673         int bytes_written = 0;
1674         struct inode *inode;
1675         struct cifsFileInfo *open_file;
1676
1677         if (!mapping || !mapping->host)
1678                 return -EFAULT;
1679
1680         inode = page->mapping->host;
1681
1682         offset += (loff_t)from;
1683         write_data = kmap(page);
1684         write_data += from;
1685
1686         if ((to > PAGE_CACHE_SIZE) || (from > to)) {
1687                 kunmap(page);
1688                 return -EIO;
1689         }
1690
1691         /* racing with truncate? */
1692         if (offset > mapping->host->i_size) {
1693                 kunmap(page);
1694                 return 0; /* don't care */
1695         }
1696
1697         /* check to make sure that we are not extending the file */
1698         if (mapping->host->i_size - offset < (loff_t)to)
1699                 to = (unsigned)(mapping->host->i_size - offset);
1700
1701         open_file = find_writable_file(CIFS_I(mapping->host), false);
1702         if (open_file) {
1703                 bytes_written = cifs_write(open_file, open_file->pid,
1704                                            write_data, to - from, &offset);
1705                 cifsFileInfo_put(open_file);
1706                 /* Does mm or vfs already set times? */
1707                 inode->i_atime = inode->i_mtime = current_fs_time(inode->i_sb);
1708                 if ((bytes_written > 0) && (offset))
1709                         rc = 0;
1710                 else if (bytes_written < 0)
1711                         rc = bytes_written;
1712         } else {
1713                 cFYI(1, "No writeable filehandles for inode");
1714                 rc = -EIO;
1715         }
1716
1717         kunmap(page);
1718         return rc;
1719 }
1720
1721 /*
1722  * Marshal up the iov array, reserving the first one for the header. Also,
1723  * set wdata->bytes.
1724  */
1725 static void
1726 cifs_writepages_marshal_iov(struct kvec *iov, struct cifs_writedata *wdata)
1727 {
1728         int i;
1729         struct inode *inode = wdata->cfile->dentry->d_inode;
1730         loff_t size = i_size_read(inode);
1731
1732         /* marshal up the pages into iov array */
1733         wdata->bytes = 0;
1734         for (i = 0; i < wdata->nr_pages; i++) {
1735                 iov[i + 1].iov_len = min(size - page_offset(wdata->pages[i]),
1736                                         (loff_t)PAGE_CACHE_SIZE);
1737                 iov[i + 1].iov_base = kmap(wdata->pages[i]);
1738                 wdata->bytes += iov[i + 1].iov_len;
1739         }
1740 }
1741
1742 static int cifs_writepages(struct address_space *mapping,
1743                            struct writeback_control *wbc)
1744 {
1745         struct cifs_sb_info *cifs_sb = CIFS_SB(mapping->host->i_sb);
1746         bool done = false, scanned = false, range_whole = false;
1747         pgoff_t end, index;
1748         struct cifs_writedata *wdata;
1749         struct page *page;
1750         int rc = 0;
1751
1752         /*
1753          * If wsize is smaller than the page cache size, default to writing
1754          * one page at a time via cifs_writepage
1755          */
1756         if (cifs_sb->wsize < PAGE_CACHE_SIZE)
1757                 return generic_writepages(mapping, wbc);
1758
1759         if (wbc->range_cyclic) {
1760                 index = mapping->writeback_index; /* Start from prev offset */
1761                 end = -1;
1762         } else {
1763                 index = wbc->range_start >> PAGE_CACHE_SHIFT;
1764                 end = wbc->range_end >> PAGE_CACHE_SHIFT;
1765                 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
1766                         range_whole = true;
1767                 scanned = true;
1768         }
1769 retry:
1770         while (!done && index <= end) {
1771                 unsigned int i, nr_pages, found_pages;
1772                 pgoff_t next = 0, tofind;
1773                 struct page **pages;
1774
1775                 tofind = min((cifs_sb->wsize / PAGE_CACHE_SIZE) - 1,
1776                                 end - index) + 1;
1777
1778                 wdata = cifs_writedata_alloc((unsigned int)tofind,
1779                                              cifs_writev_complete);
1780                 if (!wdata) {
1781                         rc = -ENOMEM;
1782                         break;
1783                 }
1784
1785                 /*
1786                  * find_get_pages_tag seems to return a max of 256 on each
1787                  * iteration, so we must call it several times in order to
1788                  * fill the array or the wsize is effectively limited to
1789                  * 256 * PAGE_CACHE_SIZE.
1790                  */
1791                 found_pages = 0;
1792                 pages = wdata->pages;
1793                 do {
1794                         nr_pages = find_get_pages_tag(mapping, &index,
1795                                                         PAGECACHE_TAG_DIRTY,
1796                                                         tofind, pages);
1797                         found_pages += nr_pages;
1798                         tofind -= nr_pages;
1799                         pages += nr_pages;
1800                 } while (nr_pages && tofind && index <= end);
1801
1802                 if (found_pages == 0) {
1803                         kref_put(&wdata->refcount, cifs_writedata_release);
1804                         break;
1805                 }
1806
1807                 nr_pages = 0;
1808                 for (i = 0; i < found_pages; i++) {
1809                         page = wdata->pages[i];
1810                         /*
1811                          * At this point we hold neither mapping->tree_lock nor
1812                          * lock on the page itself: the page may be truncated or
1813                          * invalidated (changing page->mapping to NULL), or even
1814                          * swizzled back from swapper_space to tmpfs file
1815                          * mapping
1816                          */
1817
1818                         if (nr_pages == 0)
1819                                 lock_page(page);
1820                         else if (!trylock_page(page))
1821                                 break;
1822
1823                         if (unlikely(page->mapping != mapping)) {
1824                                 unlock_page(page);
1825                                 break;
1826                         }
1827
1828                         if (!wbc->range_cyclic && page->index > end) {
1829                                 done = true;
1830                                 unlock_page(page);
1831                                 break;
1832                         }
1833
1834                         if (next && (page->index != next)) {
1835                                 /* Not next consecutive page */
1836                                 unlock_page(page);
1837                                 break;
1838                         }
1839
1840                         if (wbc->sync_mode != WB_SYNC_NONE)
1841                                 wait_on_page_writeback(page);
1842
1843                         if (PageWriteback(page) ||
1844                                         !clear_page_dirty_for_io(page)) {
1845                                 unlock_page(page);
1846                                 break;
1847                         }
1848
1849                         /*
1850                          * This actually clears the dirty bit in the radix tree.
1851                          * See cifs_writepage() for more commentary.
1852                          */
1853                         set_page_writeback(page);
1854
1855                         if (page_offset(page) >= mapping->host->i_size) {
1856                                 done = true;
1857                                 unlock_page(page);
1858                                 end_page_writeback(page);
1859                                 break;
1860                         }
1861
1862                         wdata->pages[i] = page;
1863                         next = page->index + 1;
1864                         ++nr_pages;
1865                 }
1866
1867                 /* reset index to refind any pages skipped */
1868                 if (nr_pages == 0)
1869                         index = wdata->pages[0]->index + 1;
1870
1871                 /* put any pages we aren't going to use */
1872                 for (i = nr_pages; i < found_pages; i++) {
1873                         page_cache_release(wdata->pages[i]);
1874                         wdata->pages[i] = NULL;
1875                 }
1876
1877                 /* nothing to write? */
1878                 if (nr_pages == 0) {
1879                         kref_put(&wdata->refcount, cifs_writedata_release);
1880                         continue;
1881                 }
1882
1883                 wdata->sync_mode = wbc->sync_mode;
1884                 wdata->nr_pages = nr_pages;
1885                 wdata->offset = page_offset(wdata->pages[0]);
1886                 wdata->marshal_iov = cifs_writepages_marshal_iov;
1887
1888                 do {
1889                         if (wdata->cfile != NULL)
1890                                 cifsFileInfo_put(wdata->cfile);
1891                         wdata->cfile = find_writable_file(CIFS_I(mapping->host),
1892                                                           false);
1893                         if (!wdata->cfile) {
1894                                 cERROR(1, "No writable handles for inode");
1895                                 rc = -EBADF;
1896                                 break;
1897                         }
1898                         wdata->pid = wdata->cfile->pid;
1899                         rc = cifs_async_writev(wdata);
1900                 } while (wbc->sync_mode == WB_SYNC_ALL && rc == -EAGAIN);
1901
1902                 for (i = 0; i < nr_pages; ++i)
1903                         unlock_page(wdata->pages[i]);
1904
1905                 /* send failure -- clean up the mess */
1906                 if (rc != 0) {
1907                         for (i = 0; i < nr_pages; ++i) {
1908                                 if (rc == -EAGAIN)
1909                                         redirty_page_for_writepage(wbc,
1910                                                            wdata->pages[i]);
1911                                 else
1912                                         SetPageError(wdata->pages[i]);
1913                                 end_page_writeback(wdata->pages[i]);
1914                                 page_cache_release(wdata->pages[i]);
1915                         }
1916                         if (rc != -EAGAIN)
1917                                 mapping_set_error(mapping, rc);
1918                 }
1919                 kref_put(&wdata->refcount, cifs_writedata_release);
1920
1921                 wbc->nr_to_write -= nr_pages;
1922                 if (wbc->nr_to_write <= 0)
1923                         done = true;
1924
1925                 index = next;
1926         }
1927
1928         if (!scanned && !done) {
1929                 /*
1930                  * We hit the last page and there is more work to be done: wrap
1931                  * back to the start of the file
1932                  */
1933                 scanned = true;
1934                 index = 0;
1935                 goto retry;
1936         }
1937
1938         if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
1939                 mapping->writeback_index = index;
1940
1941         return rc;
1942 }
1943
1944 static int
1945 cifs_writepage_locked(struct page *page, struct writeback_control *wbc)
1946 {
1947         int rc;
1948         unsigned int xid;
1949
1950         xid = get_xid();
1951 /* BB add check for wbc flags */
1952         page_cache_get(page);
1953         if (!PageUptodate(page))
1954                 cFYI(1, "ppw - page not up to date");
1955
1956         /*
1957          * Set the "writeback" flag, and clear "dirty" in the radix tree.
1958          *
1959          * A writepage() implementation always needs to do either this,
1960          * or re-dirty the page with "redirty_page_for_writepage()" in
1961          * the case of a failure.
1962          *
1963          * Just unlocking the page will cause the radix tree tag-bits
1964          * to fail to update with the state of the page correctly.
1965          */
1966         set_page_writeback(page);
1967 retry_write:
1968         rc = cifs_partialpagewrite(page, 0, PAGE_CACHE_SIZE);
1969         if (rc == -EAGAIN && wbc->sync_mode == WB_SYNC_ALL)
1970                 goto retry_write;
1971         else if (rc == -EAGAIN)
1972                 redirty_page_for_writepage(wbc, page);
1973         else if (rc != 0)
1974                 SetPageError(page);
1975         else
1976                 SetPageUptodate(page);
1977         end_page_writeback(page);
1978         page_cache_release(page);
1979         free_xid(xid);
1980         return rc;
1981 }
1982
1983 static int cifs_writepage(struct page *page, struct writeback_control *wbc)
1984 {
1985         int rc = cifs_writepage_locked(page, wbc);
1986         unlock_page(page);
1987         return rc;
1988 }
1989
1990 static int cifs_write_end(struct file *file, struct address_space *mapping,
1991                         loff_t pos, unsigned len, unsigned copied,
1992                         struct page *page, void *fsdata)
1993 {
1994         int rc;
1995         struct inode *inode = mapping->host;
1996         struct cifsFileInfo *cfile = file->private_data;
1997         struct cifs_sb_info *cifs_sb = CIFS_SB(cfile->dentry->d_sb);
1998         __u32 pid;
1999
2000         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
2001                 pid = cfile->pid;
2002         else
2003                 pid = current->tgid;
2004
2005         cFYI(1, "write_end for page %p from pos %lld with %d bytes",
2006                  page, pos, copied);
2007
2008         if (PageChecked(page)) {
2009                 if (copied == len)
2010                         SetPageUptodate(page);
2011                 ClearPageChecked(page);
2012         } else if (!PageUptodate(page) && copied == PAGE_CACHE_SIZE)
2013                 SetPageUptodate(page);
2014
2015         if (!PageUptodate(page)) {
2016                 char *page_data;
2017                 unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
2018                 unsigned int xid;
2019
2020                 xid = get_xid();
2021                 /* this is probably better than directly calling
2022                    partialpage_write since in this function the file handle is
2023                    known which we might as well leverage */
2024                 /* BB check if anything else missing out of ppw
2025                    such as updating last write time */
2026                 page_data = kmap(page);
2027                 rc = cifs_write(cfile, pid, page_data + offset, copied, &pos);
2028                 /* if (rc < 0) should we set writebehind rc? */
2029                 kunmap(page);
2030
2031                 free_xid(xid);
2032         } else {
2033                 rc = copied;
2034                 pos += copied;
2035                 set_page_dirty(page);
2036         }
2037
2038         if (rc > 0) {
2039                 spin_lock(&inode->i_lock);
2040                 if (pos > inode->i_size)
2041                         i_size_write(inode, pos);
2042                 spin_unlock(&inode->i_lock);
2043         }
2044
2045         unlock_page(page);
2046         page_cache_release(page);
2047
2048         return rc;
2049 }
2050
2051 int cifs_strict_fsync(struct file *file, loff_t start, loff_t end,
2052                       int datasync)
2053 {
2054         unsigned int xid;
2055         int rc = 0;
2056         struct cifs_tcon *tcon;
2057         struct cifsFileInfo *smbfile = file->private_data;
2058         struct inode *inode = file->f_path.dentry->d_inode;
2059         struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
2060
2061         rc = filemap_write_and_wait_range(inode->i_mapping, start, end);
2062         if (rc)
2063                 return rc;
2064         mutex_lock(&inode->i_mutex);
2065
2066         xid = get_xid();
2067
2068         cFYI(1, "Sync file - name: %s datasync: 0x%x",
2069                 file->f_path.dentry->d_name.name, datasync);
2070
2071         if (!CIFS_I(inode)->clientCanCacheRead) {
2072                 rc = cifs_invalidate_mapping(inode);
2073                 if (rc) {
2074                         cFYI(1, "rc: %d during invalidate phase", rc);
2075                         rc = 0; /* don't care about it in fsync */
2076                 }
2077         }
2078
2079         tcon = tlink_tcon(smbfile->tlink);
2080         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC))
2081                 rc = CIFSSMBFlush(xid, tcon, smbfile->netfid);
2082
2083         free_xid(xid);
2084         mutex_unlock(&inode->i_mutex);
2085         return rc;
2086 }
2087
2088 int cifs_fsync(struct file *file, loff_t start, loff_t end, int datasync)
2089 {
2090         unsigned int xid;
2091         int rc = 0;
2092         struct cifs_tcon *tcon;
2093         struct cifsFileInfo *smbfile = file->private_data;
2094         struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
2095         struct inode *inode = file->f_mapping->host;
2096
2097         rc = filemap_write_and_wait_range(inode->i_mapping, start, end);
2098         if (rc)
2099                 return rc;
2100         mutex_lock(&inode->i_mutex);
2101
2102         xid = get_xid();
2103
2104         cFYI(1, "Sync file - name: %s datasync: 0x%x",
2105                 file->f_path.dentry->d_name.name, datasync);
2106
2107         tcon = tlink_tcon(smbfile->tlink);
2108         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC))
2109                 rc = CIFSSMBFlush(xid, tcon, smbfile->netfid);
2110
2111         free_xid(xid);
2112         mutex_unlock(&inode->i_mutex);
2113         return rc;
2114 }
2115
2116 /*
2117  * As file closes, flush all cached write data for this inode checking
2118  * for write behind errors.
2119  */
2120 int cifs_flush(struct file *file, fl_owner_t id)
2121 {
2122         struct inode *inode = file->f_path.dentry->d_inode;
2123         int rc = 0;
2124
2125         if (file->f_mode & FMODE_WRITE)
2126                 rc = filemap_write_and_wait(inode->i_mapping);
2127
2128         cFYI(1, "Flush inode %p file %p rc %d", inode, file, rc);
2129
2130         return rc;
2131 }
2132
2133 static int
2134 cifs_write_allocate_pages(struct page **pages, unsigned long num_pages)
2135 {
2136         int rc = 0;
2137         unsigned long i;
2138
2139         for (i = 0; i < num_pages; i++) {
2140                 pages[i] = alloc_page(GFP_KERNEL|__GFP_HIGHMEM);
2141                 if (!pages[i]) {
2142                         /*
2143                          * save number of pages we have already allocated and
2144                          * return with ENOMEM error
2145                          */
2146                         num_pages = i;
2147                         rc = -ENOMEM;
2148                         break;
2149                 }
2150         }
2151
2152         if (rc) {
2153                 for (i = 0; i < num_pages; i++)
2154                         put_page(pages[i]);
2155         }
2156         return rc;
2157 }
2158
2159 static inline
2160 size_t get_numpages(const size_t wsize, const size_t len, size_t *cur_len)
2161 {
2162         size_t num_pages;
2163         size_t clen;
2164
2165         clen = min_t(const size_t, len, wsize);
2166         num_pages = DIV_ROUND_UP(clen, PAGE_SIZE);
2167
2168         if (cur_len)
2169                 *cur_len = clen;
2170
2171         return num_pages;
2172 }
2173
2174 static void
2175 cifs_uncached_marshal_iov(struct kvec *iov, struct cifs_writedata *wdata)
2176 {
2177         int i;
2178         size_t bytes = wdata->bytes;
2179
2180         /* marshal up the pages into iov array */
2181         for (i = 0; i < wdata->nr_pages; i++) {
2182                 iov[i + 1].iov_len = min_t(size_t, bytes, PAGE_SIZE);
2183                 iov[i + 1].iov_base = kmap(wdata->pages[i]);
2184                 bytes -= iov[i + 1].iov_len;
2185         }
2186 }
2187
2188 static void
2189 cifs_uncached_writev_complete(struct work_struct *work)
2190 {
2191         int i;
2192         struct cifs_writedata *wdata = container_of(work,
2193                                         struct cifs_writedata, work);
2194         struct inode *inode = wdata->cfile->dentry->d_inode;
2195         struct cifsInodeInfo *cifsi = CIFS_I(inode);
2196
2197         spin_lock(&inode->i_lock);
2198         cifs_update_eof(cifsi, wdata->offset, wdata->bytes);
2199         if (cifsi->server_eof > inode->i_size)
2200                 i_size_write(inode, cifsi->server_eof);
2201         spin_unlock(&inode->i_lock);
2202
2203         complete(&wdata->done);
2204
2205         if (wdata->result != -EAGAIN) {
2206                 for (i = 0; i < wdata->nr_pages; i++)
2207                         put_page(wdata->pages[i]);
2208         }
2209
2210         kref_put(&wdata->refcount, cifs_writedata_release);
2211 }
2212
2213 /* attempt to send write to server, retry on any -EAGAIN errors */
2214 static int
2215 cifs_uncached_retry_writev(struct cifs_writedata *wdata)
2216 {
2217         int rc;
2218
2219         do {
2220                 if (wdata->cfile->invalidHandle) {
2221                         rc = cifs_reopen_file(wdata->cfile, false);
2222                         if (rc != 0)
2223                                 continue;
2224                 }
2225                 rc = cifs_async_writev(wdata);
2226         } while (rc == -EAGAIN);
2227
2228         return rc;
2229 }
2230
2231 static ssize_t
2232 cifs_iovec_write(struct file *file, const struct iovec *iov,
2233                  unsigned long nr_segs, loff_t *poffset)
2234 {
2235         unsigned long nr_pages, i;
2236         size_t copied, len, cur_len;
2237         ssize_t total_written = 0;
2238         loff_t offset;
2239         struct iov_iter it;
2240         struct cifsFileInfo *open_file;
2241         struct cifs_tcon *tcon;
2242         struct cifs_sb_info *cifs_sb;
2243         struct cifs_writedata *wdata, *tmp;
2244         struct list_head wdata_list;
2245         int rc;
2246         pid_t pid;
2247
2248         len = iov_length(iov, nr_segs);
2249         if (!len)
2250                 return 0;
2251
2252         rc = generic_write_checks(file, poffset, &len, 0);
2253         if (rc)
2254                 return rc;
2255
2256         INIT_LIST_HEAD(&wdata_list);
2257         cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
2258         open_file = file->private_data;
2259         tcon = tlink_tcon(open_file->tlink);
2260         offset = *poffset;
2261
2262         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
2263                 pid = open_file->pid;
2264         else
2265                 pid = current->tgid;
2266
2267         iov_iter_init(&it, iov, nr_segs, len, 0);
2268         do {
2269                 size_t save_len;
2270
2271                 nr_pages = get_numpages(cifs_sb->wsize, len, &cur_len);
2272                 wdata = cifs_writedata_alloc(nr_pages,
2273                                              cifs_uncached_writev_complete);
2274                 if (!wdata) {
2275                         rc = -ENOMEM;
2276                         break;
2277                 }
2278
2279                 rc = cifs_write_allocate_pages(wdata->pages, nr_pages);
2280                 if (rc) {
2281                         kfree(wdata);
2282                         break;
2283                 }
2284
2285                 save_len = cur_len;
2286                 for (i = 0; i < nr_pages; i++) {
2287                         copied = min_t(const size_t, cur_len, PAGE_SIZE);
2288                         copied = iov_iter_copy_from_user(wdata->pages[i], &it,
2289                                                          0, copied);
2290                         cur_len -= copied;
2291                         iov_iter_advance(&it, copied);
2292                 }
2293                 cur_len = save_len - cur_len;
2294
2295                 wdata->sync_mode = WB_SYNC_ALL;
2296                 wdata->nr_pages = nr_pages;
2297                 wdata->offset = (__u64)offset;
2298                 wdata->cfile = cifsFileInfo_get(open_file);
2299                 wdata->pid = pid;
2300                 wdata->bytes = cur_len;
2301                 wdata->marshal_iov = cifs_uncached_marshal_iov;
2302                 rc = cifs_uncached_retry_writev(wdata);
2303                 if (rc) {
2304                         kref_put(&wdata->refcount, cifs_writedata_release);
2305                         break;
2306                 }
2307
2308                 list_add_tail(&wdata->list, &wdata_list);
2309                 offset += cur_len;
2310                 len -= cur_len;
2311         } while (len > 0);
2312
2313         /*
2314          * If at least one write was successfully sent, then discard any rc
2315          * value from the later writes. If the other write succeeds, then
2316          * we'll end up returning whatever was written. If it fails, then
2317          * we'll get a new rc value from that.
2318          */
2319         if (!list_empty(&wdata_list))
2320                 rc = 0;
2321
2322         /*
2323          * Wait for and collect replies for any successful sends in order of
2324          * increasing offset. Once an error is hit or we get a fatal signal
2325          * while waiting, then return without waiting for any more replies.
2326          */
2327 restart_loop:
2328         list_for_each_entry_safe(wdata, tmp, &wdata_list, list) {
2329                 if (!rc) {
2330                         /* FIXME: freezable too? */
2331                         rc = wait_for_completion_killable(&wdata->done);
2332                         if (rc)
2333                                 rc = -EINTR;
2334                         else if (wdata->result)
2335                                 rc = wdata->result;
2336                         else
2337                                 total_written += wdata->bytes;
2338
2339                         /* resend call if it's a retryable error */
2340                         if (rc == -EAGAIN) {
2341                                 rc = cifs_uncached_retry_writev(wdata);
2342                                 goto restart_loop;
2343                         }
2344                 }
2345                 list_del_init(&wdata->list);
2346                 kref_put(&wdata->refcount, cifs_writedata_release);
2347         }
2348
2349         if (total_written > 0)
2350                 *poffset += total_written;
2351
2352         cifs_stats_bytes_written(tcon, total_written);
2353         return total_written ? total_written : (ssize_t)rc;
2354 }
2355
2356 ssize_t cifs_user_writev(struct kiocb *iocb, const struct iovec *iov,
2357                                 unsigned long nr_segs, loff_t pos)
2358 {
2359         ssize_t written;
2360         struct inode *inode;
2361
2362         inode = iocb->ki_filp->f_path.dentry->d_inode;
2363
2364         /*
2365          * BB - optimize the way when signing is disabled. We can drop this
2366          * extra memory-to-memory copying and use iovec buffers for constructing
2367          * write request.
2368          */
2369
2370         written = cifs_iovec_write(iocb->ki_filp, iov, nr_segs, &pos);
2371         if (written > 0) {
2372                 CIFS_I(inode)->invalid_mapping = true;
2373                 iocb->ki_pos = pos;
2374         }
2375
2376         return written;
2377 }
2378
2379 ssize_t cifs_strict_writev(struct kiocb *iocb, const struct iovec *iov,
2380                            unsigned long nr_segs, loff_t pos)
2381 {
2382         struct inode *inode;
2383
2384         inode = iocb->ki_filp->f_path.dentry->d_inode;
2385
2386         if (CIFS_I(inode)->clientCanCacheAll)
2387                 return generic_file_aio_write(iocb, iov, nr_segs, pos);
2388
2389         /*
2390          * In strict cache mode we need to write the data to the server exactly
2391          * from the pos to pos+len-1 rather than flush all affected pages
2392          * because it may cause a error with mandatory locks on these pages but
2393          * not on the region from pos to ppos+len-1.
2394          */
2395
2396         return cifs_user_writev(iocb, iov, nr_segs, pos);
2397 }
2398
2399 static struct cifs_readdata *
2400 cifs_readdata_alloc(unsigned int nr_vecs, work_func_t complete)
2401 {
2402         struct cifs_readdata *rdata;
2403
2404         rdata = kzalloc(sizeof(*rdata) +
2405                         sizeof(struct kvec) * nr_vecs, GFP_KERNEL);
2406         if (rdata != NULL) {
2407                 kref_init(&rdata->refcount);
2408                 INIT_LIST_HEAD(&rdata->list);
2409                 init_completion(&rdata->done);
2410                 INIT_WORK(&rdata->work, complete);
2411                 INIT_LIST_HEAD(&rdata->pages);
2412         }
2413         return rdata;
2414 }
2415
2416 void
2417 cifs_readdata_release(struct kref *refcount)
2418 {
2419         struct cifs_readdata *rdata = container_of(refcount,
2420                                         struct cifs_readdata, refcount);
2421
2422         if (rdata->cfile)
2423                 cifsFileInfo_put(rdata->cfile);
2424
2425         kfree(rdata);
2426 }
2427
2428 static int
2429 cifs_read_allocate_pages(struct list_head *list, unsigned int npages)
2430 {
2431         int rc = 0;
2432         struct page *page, *tpage;
2433         unsigned int i;
2434
2435         for (i = 0; i < npages; i++) {
2436                 page = alloc_page(GFP_KERNEL|__GFP_HIGHMEM);
2437                 if (!page) {
2438                         rc = -ENOMEM;
2439                         break;
2440                 }
2441                 list_add(&page->lru, list);
2442         }
2443
2444         if (rc) {
2445                 list_for_each_entry_safe(page, tpage, list, lru) {
2446                         list_del(&page->lru);
2447                         put_page(page);
2448                 }
2449         }
2450         return rc;
2451 }
2452
2453 static void
2454 cifs_uncached_readdata_release(struct kref *refcount)
2455 {
2456         struct page *page, *tpage;
2457         struct cifs_readdata *rdata = container_of(refcount,
2458                                         struct cifs_readdata, refcount);
2459
2460         list_for_each_entry_safe(page, tpage, &rdata->pages, lru) {
2461                 list_del(&page->lru);
2462                 put_page(page);
2463         }
2464         cifs_readdata_release(refcount);
2465 }
2466
2467 static int
2468 cifs_retry_async_readv(struct cifs_readdata *rdata)
2469 {
2470         int rc;
2471
2472         do {
2473                 if (rdata->cfile->invalidHandle) {
2474                         rc = cifs_reopen_file(rdata->cfile, true);
2475                         if (rc != 0)
2476                                 continue;
2477                 }
2478                 rc = cifs_async_readv(rdata);
2479         } while (rc == -EAGAIN);
2480
2481         return rc;
2482 }
2483
2484 /**
2485  * cifs_readdata_to_iov - copy data from pages in response to an iovec
2486  * @rdata:      the readdata response with list of pages holding data
2487  * @iov:        vector in which we should copy the data
2488  * @nr_segs:    number of segments in vector
2489  * @offset:     offset into file of the first iovec
2490  * @copied:     used to return the amount of data copied to the iov
2491  *
2492  * This function copies data from a list of pages in a readdata response into
2493  * an array of iovecs. It will first calculate where the data should go
2494  * based on the info in the readdata and then copy the data into that spot.
2495  */
2496 static ssize_t
2497 cifs_readdata_to_iov(struct cifs_readdata *rdata, const struct iovec *iov,
2498                         unsigned long nr_segs, loff_t offset, ssize_t *copied)
2499 {
2500         int rc = 0;
2501         struct iov_iter ii;
2502         size_t pos = rdata->offset - offset;
2503         struct page *page, *tpage;
2504         ssize_t remaining = rdata->bytes;
2505         unsigned char *pdata;
2506
2507         /* set up iov_iter and advance to the correct offset */
2508         iov_iter_init(&ii, iov, nr_segs, iov_length(iov, nr_segs), 0);
2509         iov_iter_advance(&ii, pos);
2510
2511         *copied = 0;
2512         list_for_each_entry_safe(page, tpage, &rdata->pages, lru) {
2513                 ssize_t copy;
2514
2515                 /* copy a whole page or whatever's left */
2516                 copy = min_t(ssize_t, remaining, PAGE_SIZE);
2517
2518                 /* ...but limit it to whatever space is left in the iov */
2519                 copy = min_t(ssize_t, copy, iov_iter_count(&ii));
2520
2521                 /* go while there's data to be copied and no errors */
2522                 if (copy && !rc) {
2523                         pdata = kmap(page);
2524                         rc = memcpy_toiovecend(ii.iov, pdata, ii.iov_offset,
2525                                                 (int)copy);
2526                         kunmap(page);
2527                         if (!rc) {
2528                                 *copied += copy;
2529                                 remaining -= copy;
2530                                 iov_iter_advance(&ii, copy);
2531                         }
2532                 }
2533
2534                 list_del(&page->lru);
2535                 put_page(page);
2536         }
2537
2538         return rc;
2539 }
2540
2541 static void
2542 cifs_uncached_readv_complete(struct work_struct *work)
2543 {
2544         struct cifs_readdata *rdata = container_of(work,
2545                                                 struct cifs_readdata, work);
2546
2547         /* if the result is non-zero then the pages weren't kmapped */
2548         if (rdata->result == 0) {
2549                 struct page *page;
2550
2551                 list_for_each_entry(page, &rdata->pages, lru)
2552                         kunmap(page);
2553         }
2554
2555         complete(&rdata->done);
2556         kref_put(&rdata->refcount, cifs_uncached_readdata_release);
2557 }
2558
2559 static int
2560 cifs_uncached_read_marshal_iov(struct cifs_readdata *rdata,
2561                                 unsigned int remaining)
2562 {
2563         int len = 0;
2564         struct page *page, *tpage;
2565
2566         rdata->nr_iov = 1;
2567         list_for_each_entry_safe(page, tpage, &rdata->pages, lru) {
2568                 if (remaining >= PAGE_SIZE) {
2569                         /* enough data to fill the page */
2570                         rdata->iov[rdata->nr_iov].iov_base = kmap(page);
2571                         rdata->iov[rdata->nr_iov].iov_len = PAGE_SIZE;
2572                         cFYI(1, "%u: idx=%lu iov_base=%p iov_len=%zu",
2573                                 rdata->nr_iov, page->index,
2574                                 rdata->iov[rdata->nr_iov].iov_base,
2575                                 rdata->iov[rdata->nr_iov].iov_len);
2576                         ++rdata->nr_iov;
2577                         len += PAGE_SIZE;
2578                         remaining -= PAGE_SIZE;
2579                 } else if (remaining > 0) {
2580                         /* enough for partial page, fill and zero the rest */
2581                         rdata->iov[rdata->nr_iov].iov_base = kmap(page);
2582                         rdata->iov[rdata->nr_iov].iov_len = remaining;
2583                         cFYI(1, "%u: idx=%lu iov_base=%p iov_len=%zu",
2584                                 rdata->nr_iov, page->index,
2585                                 rdata->iov[rdata->nr_iov].iov_base,
2586                                 rdata->iov[rdata->nr_iov].iov_len);
2587                         memset(rdata->iov[rdata->nr_iov].iov_base + remaining,
2588                                 '\0', PAGE_SIZE - remaining);
2589                         ++rdata->nr_iov;
2590                         len += remaining;
2591                         remaining = 0;
2592                 } else {
2593                         /* no need to hold page hostage */
2594                         list_del(&page->lru);
2595                         put_page(page);
2596                 }
2597         }
2598
2599         return len;
2600 }
2601
2602 static ssize_t
2603 cifs_iovec_read(struct file *file, const struct iovec *iov,
2604                  unsigned long nr_segs, loff_t *poffset)
2605 {
2606         ssize_t rc;
2607         size_t len, cur_len;
2608         ssize_t total_read = 0;
2609         loff_t offset = *poffset;
2610         unsigned int npages;
2611         struct cifs_sb_info *cifs_sb;
2612         struct cifs_tcon *tcon;
2613         struct cifsFileInfo *open_file;
2614         struct cifs_readdata *rdata, *tmp;
2615         struct list_head rdata_list;
2616         pid_t pid;
2617
2618         if (!nr_segs)
2619                 return 0;
2620
2621         len = iov_length(iov, nr_segs);
2622         if (!len)
2623                 return 0;
2624
2625         INIT_LIST_HEAD(&rdata_list);
2626         cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
2627         open_file = file->private_data;
2628         tcon = tlink_tcon(open_file->tlink);
2629
2630         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
2631                 pid = open_file->pid;
2632         else
2633                 pid = current->tgid;
2634
2635         if ((file->f_flags & O_ACCMODE) == O_WRONLY)
2636                 cFYI(1, "attempting read on write only file instance");
2637
2638         do {
2639                 cur_len = min_t(const size_t, len - total_read, cifs_sb->rsize);
2640                 npages = DIV_ROUND_UP(cur_len, PAGE_SIZE);
2641
2642                 /* allocate a readdata struct */
2643                 rdata = cifs_readdata_alloc(npages,
2644                                             cifs_uncached_readv_complete);
2645                 if (!rdata) {
2646                         rc = -ENOMEM;
2647                         goto error;
2648                 }
2649
2650                 rc = cifs_read_allocate_pages(&rdata->pages, npages);
2651                 if (rc)
2652                         goto error;
2653
2654                 rdata->cfile = cifsFileInfo_get(open_file);
2655                 rdata->offset = offset;
2656                 rdata->bytes = cur_len;
2657                 rdata->pid = pid;
2658                 rdata->marshal_iov = cifs_uncached_read_marshal_iov;
2659
2660                 rc = cifs_retry_async_readv(rdata);
2661 error:
2662                 if (rc) {
2663                         kref_put(&rdata->refcount,
2664                                  cifs_uncached_readdata_release);
2665                         break;
2666                 }
2667
2668                 list_add_tail(&rdata->list, &rdata_list);
2669                 offset += cur_len;
2670                 len -= cur_len;
2671         } while (len > 0);
2672
2673         /* if at least one read request send succeeded, then reset rc */
2674         if (!list_empty(&rdata_list))
2675                 rc = 0;
2676
2677         /* the loop below should proceed in the order of increasing offsets */
2678 restart_loop:
2679         list_for_each_entry_safe(rdata, tmp, &rdata_list, list) {
2680                 if (!rc) {
2681                         ssize_t copied;
2682
2683                         /* FIXME: freezable sleep too? */
2684                         rc = wait_for_completion_killable(&rdata->done);
2685                         if (rc)
2686                                 rc = -EINTR;
2687                         else if (rdata->result)
2688                                 rc = rdata->result;
2689                         else {
2690                                 rc = cifs_readdata_to_iov(rdata, iov,
2691                                                         nr_segs, *poffset,
2692                                                         &copied);
2693                                 total_read += copied;
2694                         }
2695
2696                         /* resend call if it's a retryable error */
2697                         if (rc == -EAGAIN) {
2698                                 rc = cifs_retry_async_readv(rdata);
2699                                 goto restart_loop;
2700                         }
2701                 }
2702                 list_del_init(&rdata->list);
2703                 kref_put(&rdata->refcount, cifs_uncached_readdata_release);
2704         }
2705
2706         cifs_stats_bytes_read(tcon, total_read);
2707         *poffset += total_read;
2708
2709         return total_read ? total_read : rc;
2710 }
2711
2712 ssize_t cifs_user_readv(struct kiocb *iocb, const struct iovec *iov,
2713                                unsigned long nr_segs, loff_t pos)
2714 {
2715         ssize_t read;
2716
2717         read = cifs_iovec_read(iocb->ki_filp, iov, nr_segs, &pos);
2718         if (read > 0)
2719                 iocb->ki_pos = pos;
2720
2721         return read;
2722 }
2723
2724 ssize_t cifs_strict_readv(struct kiocb *iocb, const struct iovec *iov,
2725                           unsigned long nr_segs, loff_t pos)
2726 {
2727         struct inode *inode;
2728
2729         inode = iocb->ki_filp->f_path.dentry->d_inode;
2730
2731         if (CIFS_I(inode)->clientCanCacheRead)
2732                 return generic_file_aio_read(iocb, iov, nr_segs, pos);
2733
2734         /*
2735          * In strict cache mode we need to read from the server all the time
2736          * if we don't have level II oplock because the server can delay mtime
2737          * change - so we can't make a decision about inode invalidating.
2738          * And we can also fail with pagereading if there are mandatory locks
2739          * on pages affected by this read but not on the region from pos to
2740          * pos+len-1.
2741          */
2742
2743         return cifs_user_readv(iocb, iov, nr_segs, pos);
2744 }
2745
2746 static ssize_t cifs_read(struct file *file, char *read_data, size_t read_size,
2747                          loff_t *poffset)
2748 {
2749         int rc = -EACCES;
2750         unsigned int bytes_read = 0;
2751         unsigned int total_read;
2752         unsigned int current_read_size;
2753         unsigned int rsize;
2754         struct cifs_sb_info *cifs_sb;
2755         struct cifs_tcon *tcon;
2756         unsigned int xid;
2757         char *current_offset;
2758         struct cifsFileInfo *open_file;
2759         struct cifs_io_parms io_parms;
2760         int buf_type = CIFS_NO_BUFFER;
2761         __u32 pid;
2762
2763         xid = get_xid();
2764         cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
2765
2766         /* FIXME: set up handlers for larger reads and/or convert to async */
2767         rsize = min_t(unsigned int, cifs_sb->rsize, CIFSMaxBufSize);
2768
2769         if (file->private_data == NULL) {
2770                 rc = -EBADF;
2771                 free_xid(xid);
2772                 return rc;
2773         }
2774         open_file = file->private_data;
2775         tcon = tlink_tcon(open_file->tlink);
2776
2777         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
2778                 pid = open_file->pid;
2779         else
2780                 pid = current->tgid;
2781
2782         if ((file->f_flags & O_ACCMODE) == O_WRONLY)
2783                 cFYI(1, "attempting read on write only file instance");
2784
2785         for (total_read = 0, current_offset = read_data;
2786              read_size > total_read;
2787              total_read += bytes_read, current_offset += bytes_read) {
2788                 current_read_size = min_t(uint, read_size - total_read, rsize);
2789                 /*
2790                  * For windows me and 9x we do not want to request more than it
2791                  * negotiated since it will refuse the read then.
2792                  */
2793                 if ((tcon->ses) && !(tcon->ses->capabilities &
2794                                 tcon->ses->server->vals->cap_large_files)) {
2795                         current_read_size = min_t(uint, current_read_size,
2796                                         CIFSMaxBufSize);
2797                 }
2798                 rc = -EAGAIN;
2799                 while (rc == -EAGAIN) {
2800                         if (open_file->invalidHandle) {
2801                                 rc = cifs_reopen_file(open_file, true);
2802                                 if (rc != 0)
2803                                         break;
2804                         }
2805                         io_parms.netfid = open_file->netfid;
2806                         io_parms.pid = pid;
2807                         io_parms.tcon = tcon;
2808                         io_parms.offset = *poffset;
2809                         io_parms.length = current_read_size;
2810                         rc = CIFSSMBRead(xid, &io_parms, &bytes_read,
2811                                          &current_offset, &buf_type);
2812                 }
2813                 if (rc || (bytes_read == 0)) {
2814                         if (total_read) {
2815                                 break;
2816                         } else {
2817                                 free_xid(xid);
2818                                 return rc;
2819                         }
2820                 } else {
2821                         cifs_stats_bytes_read(tcon, total_read);
2822                         *poffset += bytes_read;
2823                 }
2824         }
2825         free_xid(xid);
2826         return total_read;
2827 }
2828
2829 /*
2830  * If the page is mmap'ed into a process' page tables, then we need to make
2831  * sure that it doesn't change while being written back.
2832  */
2833 static int
2834 cifs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
2835 {
2836         struct page *page = vmf->page;
2837
2838         lock_page(page);
2839         return VM_FAULT_LOCKED;
2840 }
2841
2842 static struct vm_operations_struct cifs_file_vm_ops = {
2843         .fault = filemap_fault,
2844         .page_mkwrite = cifs_page_mkwrite,
2845 };
2846
2847 int cifs_file_strict_mmap(struct file *file, struct vm_area_struct *vma)
2848 {
2849         int rc, xid;
2850         struct inode *inode = file->f_path.dentry->d_inode;
2851
2852         xid = get_xid();
2853
2854         if (!CIFS_I(inode)->clientCanCacheRead) {
2855                 rc = cifs_invalidate_mapping(inode);
2856                 if (rc)
2857                         return rc;
2858         }
2859
2860         rc = generic_file_mmap(file, vma);
2861         if (rc == 0)
2862                 vma->vm_ops = &cifs_file_vm_ops;
2863         free_xid(xid);
2864         return rc;
2865 }
2866
2867 int cifs_file_mmap(struct file *file, struct vm_area_struct *vma)
2868 {
2869         int rc, xid;
2870
2871         xid = get_xid();
2872         rc = cifs_revalidate_file(file);
2873         if (rc) {
2874                 cFYI(1, "Validation prior to mmap failed, error=%d", rc);
2875                 free_xid(xid);
2876                 return rc;
2877         }
2878         rc = generic_file_mmap(file, vma);
2879         if (rc == 0)
2880                 vma->vm_ops = &cifs_file_vm_ops;
2881         free_xid(xid);
2882         return rc;
2883 }
2884
2885 static void
2886 cifs_readv_complete(struct work_struct *work)
2887 {
2888         struct cifs_readdata *rdata = container_of(work,
2889                                                 struct cifs_readdata, work);
2890         struct page *page, *tpage;
2891
2892         list_for_each_entry_safe(page, tpage, &rdata->pages, lru) {
2893                 list_del(&page->lru);
2894                 lru_cache_add_file(page);
2895
2896                 if (rdata->result == 0) {
2897                         kunmap(page);
2898                         flush_dcache_page(page);
2899                         SetPageUptodate(page);
2900                 }
2901
2902                 unlock_page(page);
2903
2904                 if (rdata->result == 0)
2905                         cifs_readpage_to_fscache(rdata->mapping->host, page);
2906
2907                 page_cache_release(page);
2908         }
2909         kref_put(&rdata->refcount, cifs_readdata_release);
2910 }
2911
2912 static int
2913 cifs_readpages_marshal_iov(struct cifs_readdata *rdata, unsigned int remaining)
2914 {
2915         int len = 0;
2916         struct page *page, *tpage;
2917         u64 eof;
2918         pgoff_t eof_index;
2919
2920         /* determine the eof that the server (probably) has */
2921         eof = CIFS_I(rdata->mapping->host)->server_eof;
2922         eof_index = eof ? (eof - 1) >> PAGE_CACHE_SHIFT : 0;
2923         cFYI(1, "eof=%llu eof_index=%lu", eof, eof_index);
2924
2925         rdata->nr_iov = 1;
2926         list_for_each_entry_safe(page, tpage, &rdata->pages, lru) {
2927                 if (remaining >= PAGE_CACHE_SIZE) {
2928                         /* enough data to fill the page */
2929                         rdata->iov[rdata->nr_iov].iov_base = kmap(page);
2930                         rdata->iov[rdata->nr_iov].iov_len = PAGE_CACHE_SIZE;
2931                         cFYI(1, "%u: idx=%lu iov_base=%p iov_len=%zu",
2932                                 rdata->nr_iov, page->index,
2933                                 rdata->iov[rdata->nr_iov].iov_base,
2934                                 rdata->iov[rdata->nr_iov].iov_len);
2935                         ++rdata->nr_iov;
2936                         len += PAGE_CACHE_SIZE;
2937                         remaining -= PAGE_CACHE_SIZE;
2938                 } else if (remaining > 0) {
2939                         /* enough for partial page, fill and zero the rest */
2940                         rdata->iov[rdata->nr_iov].iov_base = kmap(page);
2941                         rdata->iov[rdata->nr_iov].iov_len = remaining;
2942                         cFYI(1, "%u: idx=%lu iov_base=%p iov_len=%zu",
2943                                 rdata->nr_iov, page->index,
2944                                 rdata->iov[rdata->nr_iov].iov_base,
2945                                 rdata->iov[rdata->nr_iov].iov_len);
2946                         memset(rdata->iov[rdata->nr_iov].iov_base + remaining,
2947                                 '\0', PAGE_CACHE_SIZE - remaining);
2948                         ++rdata->nr_iov;
2949                         len += remaining;
2950                         remaining = 0;
2951                 } else if (page->index > eof_index) {
2952                         /*
2953                          * The VFS will not try to do readahead past the
2954                          * i_size, but it's possible that we have outstanding
2955                          * writes with gaps in the middle and the i_size hasn't
2956                          * caught up yet. Populate those with zeroed out pages
2957                          * to prevent the VFS from repeatedly attempting to
2958                          * fill them until the writes are flushed.
2959                          */
2960                         zero_user(page, 0, PAGE_CACHE_SIZE);
2961                         list_del(&page->lru);
2962                         lru_cache_add_file(page);
2963                         flush_dcache_page(page);
2964                         SetPageUptodate(page);
2965                         unlock_page(page);
2966                         page_cache_release(page);
2967                 } else {
2968                         /* no need to hold page hostage */
2969                         list_del(&page->lru);
2970                         lru_cache_add_file(page);
2971                         unlock_page(page);
2972                         page_cache_release(page);
2973                 }
2974         }
2975
2976         return len;
2977 }
2978
2979 static int cifs_readpages(struct file *file, struct address_space *mapping,
2980         struct list_head *page_list, unsigned num_pages)
2981 {
2982         int rc;
2983         struct list_head tmplist;
2984         struct cifsFileInfo *open_file = file->private_data;
2985         struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
2986         unsigned int rsize = cifs_sb->rsize;
2987         pid_t pid;
2988
2989         /*
2990          * Give up immediately if rsize is too small to read an entire page.
2991          * The VFS will fall back to readpage. We should never reach this
2992          * point however since we set ra_pages to 0 when the rsize is smaller
2993          * than a cache page.
2994          */
2995         if (unlikely(rsize < PAGE_CACHE_SIZE))
2996                 return 0;
2997
2998         /*
2999          * Reads as many pages as possible from fscache. Returns -ENOBUFS
3000          * immediately if the cookie is negative
3001          */
3002         rc = cifs_readpages_from_fscache(mapping->host, mapping, page_list,
3003                                          &num_pages);
3004         if (rc == 0)
3005                 return rc;
3006
3007         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
3008                 pid = open_file->pid;
3009         else
3010                 pid = current->tgid;
3011
3012         rc = 0;
3013         INIT_LIST_HEAD(&tmplist);
3014
3015         cFYI(1, "%s: file=%p mapping=%p num_pages=%u", __func__, file,
3016                 mapping, num_pages);
3017
3018         /*
3019          * Start with the page at end of list and move it to private
3020          * list. Do the same with any following pages until we hit
3021          * the rsize limit, hit an index discontinuity, or run out of
3022          * pages. Issue the async read and then start the loop again
3023          * until the list is empty.
3024          *
3025          * Note that list order is important. The page_list is in
3026          * the order of declining indexes. When we put the pages in
3027          * the rdata->pages, then we want them in increasing order.
3028          */
3029         while (!list_empty(page_list)) {
3030                 unsigned int bytes = PAGE_CACHE_SIZE;
3031                 unsigned int expected_index;
3032                 unsigned int nr_pages = 1;
3033                 loff_t offset;
3034                 struct page *page, *tpage;
3035                 struct cifs_readdata *rdata;
3036
3037                 page = list_entry(page_list->prev, struct page, lru);
3038
3039                 /*
3040                  * Lock the page and put it in the cache. Since no one else
3041                  * should have access to this page, we're safe to simply set
3042                  * PG_locked without checking it first.
3043                  */
3044                 __set_page_locked(page);
3045                 rc = add_to_page_cache_locked(page, mapping,
3046                                               page->index, GFP_KERNEL);
3047
3048                 /* give up if we can't stick it in the cache */
3049                 if (rc) {
3050                         __clear_page_locked(page);
3051                         break;
3052                 }
3053
3054                 /* move first page to the tmplist */
3055                 offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
3056                 list_move_tail(&page->lru, &tmplist);
3057
3058                 /* now try and add more pages onto the request */
3059                 expected_index = page->index + 1;
3060                 list_for_each_entry_safe_reverse(page, tpage, page_list, lru) {
3061                         /* discontinuity ? */
3062                         if (page->index != expected_index)
3063                                 break;
3064
3065                         /* would this page push the read over the rsize? */
3066                         if (bytes + PAGE_CACHE_SIZE > rsize)
3067                                 break;
3068
3069                         __set_page_locked(page);
3070                         if (add_to_page_cache_locked(page, mapping,
3071                                                 page->index, GFP_KERNEL)) {
3072                                 __clear_page_locked(page);
3073                                 break;
3074                         }
3075                         list_move_tail(&page->lru, &tmplist);
3076                         bytes += PAGE_CACHE_SIZE;
3077                         expected_index++;
3078                         nr_pages++;
3079                 }
3080
3081                 rdata = cifs_readdata_alloc(nr_pages, cifs_readv_complete);
3082                 if (!rdata) {
3083                         /* best to give up if we're out of mem */
3084                         list_for_each_entry_safe(page, tpage, &tmplist, lru) {
3085                                 list_del(&page->lru);
3086                                 lru_cache_add_file(page);
3087                                 unlock_page(page);
3088                                 page_cache_release(page);
3089                         }
3090                         rc = -ENOMEM;
3091                         break;
3092                 }
3093
3094                 rdata->cfile = cifsFileInfo_get(open_file);
3095                 rdata->mapping = mapping;
3096                 rdata->offset = offset;
3097                 rdata->bytes = bytes;
3098                 rdata->pid = pid;
3099                 rdata->marshal_iov = cifs_readpages_marshal_iov;
3100                 list_splice_init(&tmplist, &rdata->pages);
3101
3102                 rc = cifs_retry_async_readv(rdata);
3103                 if (rc != 0) {
3104                         list_for_each_entry_safe(page, tpage, &rdata->pages,
3105                                                  lru) {
3106                                 list_del(&page->lru);
3107                                 lru_cache_add_file(page);
3108                                 unlock_page(page);
3109                                 page_cache_release(page);
3110                         }
3111                         kref_put(&rdata->refcount, cifs_readdata_release);
3112                         break;
3113                 }
3114
3115                 kref_put(&rdata->refcount, cifs_readdata_release);
3116         }
3117
3118         return rc;
3119 }
3120
3121 static int cifs_readpage_worker(struct file *file, struct page *page,
3122         loff_t *poffset)
3123 {
3124         char *read_data;
3125         int rc;
3126
3127         /* Is the page cached? */
3128         rc = cifs_readpage_from_fscache(file->f_path.dentry->d_inode, page);
3129         if (rc == 0)
3130                 goto read_complete;
3131
3132         page_cache_get(page);
3133         read_data = kmap(page);
3134         /* for reads over a certain size could initiate async read ahead */
3135
3136         rc = cifs_read(file, read_data, PAGE_CACHE_SIZE, poffset);
3137
3138         if (rc < 0)
3139                 goto io_error;
3140         else
3141                 cFYI(1, "Bytes read %d", rc);
3142
3143         file->f_path.dentry->d_inode->i_atime =
3144                 current_fs_time(file->f_path.dentry->d_inode->i_sb);
3145
3146         if (PAGE_CACHE_SIZE > rc)
3147                 memset(read_data + rc, 0, PAGE_CACHE_SIZE - rc);
3148
3149         flush_dcache_page(page);
3150         SetPageUptodate(page);
3151
3152         /* send this page to the cache */
3153         cifs_readpage_to_fscache(file->f_path.dentry->d_inode, page);
3154
3155         rc = 0;
3156
3157 io_error:
3158         kunmap(page);
3159         page_cache_release(page);
3160
3161 read_complete:
3162         return rc;
3163 }
3164
3165 static int cifs_readpage(struct file *file, struct page *page)
3166 {
3167         loff_t offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
3168         int rc = -EACCES;
3169         unsigned int xid;
3170
3171         xid = get_xid();
3172
3173         if (file->private_data == NULL) {
3174                 rc = -EBADF;
3175                 free_xid(xid);
3176                 return rc;
3177         }
3178
3179         cFYI(1, "readpage %p at offset %d 0x%x",
3180                  page, (int)offset, (int)offset);
3181
3182         rc = cifs_readpage_worker(file, page, &offset);
3183
3184         unlock_page(page);
3185
3186         free_xid(xid);
3187         return rc;
3188 }
3189
3190 static int is_inode_writable(struct cifsInodeInfo *cifs_inode)
3191 {
3192         struct cifsFileInfo *open_file;
3193
3194         spin_lock(&cifs_file_list_lock);
3195         list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
3196                 if (OPEN_FMODE(open_file->f_flags) & FMODE_WRITE) {
3197                         spin_unlock(&cifs_file_list_lock);
3198                         return 1;
3199                 }
3200         }
3201         spin_unlock(&cifs_file_list_lock);
3202         return 0;
3203 }
3204
3205 /* We do not want to update the file size from server for inodes
3206    open for write - to avoid races with writepage extending
3207    the file - in the future we could consider allowing
3208    refreshing the inode only on increases in the file size
3209    but this is tricky to do without racing with writebehind
3210    page caching in the current Linux kernel design */
3211 bool is_size_safe_to_change(struct cifsInodeInfo *cifsInode, __u64 end_of_file)
3212 {
3213         if (!cifsInode)
3214                 return true;
3215
3216         if (is_inode_writable(cifsInode)) {
3217                 /* This inode is open for write at least once */
3218                 struct cifs_sb_info *cifs_sb;
3219
3220                 cifs_sb = CIFS_SB(cifsInode->vfs_inode.i_sb);
3221                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DIRECT_IO) {
3222                         /* since no page cache to corrupt on directio
3223                         we can change size safely */
3224                         return true;
3225                 }
3226
3227                 if (i_size_read(&cifsInode->vfs_inode) < end_of_file)
3228                         return true;
3229
3230                 return false;
3231         } else
3232                 return true;
3233 }
3234
3235 static int cifs_write_begin(struct file *file, struct address_space *mapping,
3236                         loff_t pos, unsigned len, unsigned flags,
3237                         struct page **pagep, void **fsdata)
3238 {
3239         pgoff_t index = pos >> PAGE_CACHE_SHIFT;
3240         loff_t offset = pos & (PAGE_CACHE_SIZE - 1);
3241         loff_t page_start = pos & PAGE_MASK;
3242         loff_t i_size;
3243         struct page *page;
3244         int rc = 0;
3245
3246         cFYI(1, "write_begin from %lld len %d", (long long)pos, len);
3247
3248         page = grab_cache_page_write_begin(mapping, index, flags);
3249         if (!page) {
3250                 rc = -ENOMEM;
3251                 goto out;
3252         }
3253
3254         if (PageUptodate(page))
3255                 goto out;
3256
3257         /*
3258          * If we write a full page it will be up to date, no need to read from
3259          * the server. If the write is short, we'll end up doing a sync write
3260          * instead.
3261          */
3262         if (len == PAGE_CACHE_SIZE)
3263                 goto out;
3264
3265         /*
3266          * optimize away the read when we have an oplock, and we're not
3267          * expecting to use any of the data we'd be reading in. That
3268          * is, when the page lies beyond the EOF, or straddles the EOF
3269          * and the write will cover all of the existing data.
3270          */
3271         if (CIFS_I(mapping->host)->clientCanCacheRead) {
3272                 i_size = i_size_read(mapping->host);
3273                 if (page_start >= i_size ||
3274                     (offset == 0 && (pos + len) >= i_size)) {
3275                         zero_user_segments(page, 0, offset,
3276                                            offset + len,
3277                                            PAGE_CACHE_SIZE);
3278                         /*
3279                          * PageChecked means that the parts of the page
3280                          * to which we're not writing are considered up
3281                          * to date. Once the data is copied to the
3282                          * page, it can be set uptodate.
3283                          */
3284                         SetPageChecked(page);
3285                         goto out;
3286                 }
3287         }
3288
3289         if ((file->f_flags & O_ACCMODE) != O_WRONLY) {
3290                 /*
3291                  * might as well read a page, it is fast enough. If we get
3292                  * an error, we don't need to return it. cifs_write_end will
3293                  * do a sync write instead since PG_uptodate isn't set.
3294                  */
3295                 cifs_readpage_worker(file, page, &page_start);
3296         } else {
3297                 /* we could try using another file handle if there is one -
3298                    but how would we lock it to prevent close of that handle
3299                    racing with this read? In any case
3300                    this will be written out by write_end so is fine */
3301         }
3302 out:
3303         *pagep = page;
3304         return rc;
3305 }
3306
3307 static int cifs_release_page(struct page *page, gfp_t gfp)
3308 {
3309         if (PagePrivate(page))
3310                 return 0;
3311
3312         return cifs_fscache_release_page(page, gfp);
3313 }
3314
3315 static void cifs_invalidate_page(struct page *page, unsigned long offset)
3316 {
3317         struct cifsInodeInfo *cifsi = CIFS_I(page->mapping->host);
3318
3319         if (offset == 0)
3320                 cifs_fscache_invalidate_page(page, &cifsi->vfs_inode);
3321 }
3322
3323 static int cifs_launder_page(struct page *page)
3324 {
3325         int rc = 0;
3326         loff_t range_start = page_offset(page);
3327         loff_t range_end = range_start + (loff_t)(PAGE_CACHE_SIZE - 1);
3328         struct writeback_control wbc = {
3329                 .sync_mode = WB_SYNC_ALL,
3330                 .nr_to_write = 0,
3331                 .range_start = range_start,
3332                 .range_end = range_end,
3333         };
3334
3335         cFYI(1, "Launder page: %p", page);
3336
3337         if (clear_page_dirty_for_io(page))
3338                 rc = cifs_writepage_locked(page, &wbc);
3339
3340         cifs_fscache_invalidate_page(page, page->mapping->host);
3341         return rc;
3342 }
3343
3344 void cifs_oplock_break(struct work_struct *work)
3345 {
3346         struct cifsFileInfo *cfile = container_of(work, struct cifsFileInfo,
3347                                                   oplock_break);
3348         struct inode *inode = cfile->dentry->d_inode;
3349         struct cifsInodeInfo *cinode = CIFS_I(inode);
3350         int rc = 0;
3351
3352         if (inode && S_ISREG(inode->i_mode)) {
3353                 if (cinode->clientCanCacheRead)
3354                         break_lease(inode, O_RDONLY);
3355                 else
3356                         break_lease(inode, O_WRONLY);
3357                 rc = filemap_fdatawrite(inode->i_mapping);
3358                 if (cinode->clientCanCacheRead == 0) {
3359                         rc = filemap_fdatawait(inode->i_mapping);
3360                         mapping_set_error(inode->i_mapping, rc);
3361                         invalidate_remote_inode(inode);
3362                 }
3363                 cFYI(1, "Oplock flush inode %p rc %d", inode, rc);
3364         }
3365
3366         rc = cifs_push_locks(cfile);
3367         if (rc)
3368                 cERROR(1, "Push locks rc = %d", rc);
3369
3370         /*
3371          * releasing stale oplock after recent reconnect of smb session using
3372          * a now incorrect file handle is not a data integrity issue but do
3373          * not bother sending an oplock release if session to server still is
3374          * disconnected since oplock already released by the server
3375          */
3376         if (!cfile->oplock_break_cancelled) {
3377                 rc = CIFSSMBLock(0, tlink_tcon(cfile->tlink), cfile->netfid,
3378                                  current->tgid, 0, 0, 0, 0,
3379                                  LOCKING_ANDX_OPLOCK_RELEASE, false,
3380                                  cinode->clientCanCacheRead ? 1 : 0);
3381                 cFYI(1, "Oplock release rc = %d", rc);
3382         }
3383 }
3384
3385 const struct address_space_operations cifs_addr_ops = {
3386         .readpage = cifs_readpage,
3387         .readpages = cifs_readpages,
3388         .writepage = cifs_writepage,
3389         .writepages = cifs_writepages,
3390         .write_begin = cifs_write_begin,
3391         .write_end = cifs_write_end,
3392         .set_page_dirty = __set_page_dirty_nobuffers,
3393         .releasepage = cifs_release_page,
3394         .invalidatepage = cifs_invalidate_page,
3395         .launder_page = cifs_launder_page,
3396 };
3397
3398 /*
3399  * cifs_readpages requires the server to support a buffer large enough to
3400  * contain the header plus one complete page of data.  Otherwise, we need
3401  * to leave cifs_readpages out of the address space operations.
3402  */
3403 const struct address_space_operations cifs_addr_ops_smallbuf = {
3404         .readpage = cifs_readpage,
3405         .writepage = cifs_writepage,
3406         .writepages = cifs_writepages,
3407         .write_begin = cifs_write_begin,
3408         .write_end = cifs_write_end,
3409         .set_page_dirty = __set_page_dirty_nobuffers,
3410         .releasepage = cifs_release_page,
3411         .invalidatepage = cifs_invalidate_page,
3412         .launder_page = cifs_launder_page,
3413 };