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
  47 static inline int cifs_convert_flags(unsigned int flags)
  48 {
  49         if ((flags & O_ACCMODE) == O_RDONLY)
  50                 return GENERIC_READ;
  51         else if ((flags & O_ACCMODE) == O_WRONLY)
  52                 return GENERIC_WRITE;
  53         else if ((flags & O_ACCMODE) == O_RDWR) {
  54                 /* GENERIC_ALL is too much permission to request
  55                    can cause unnecessary access denied on create */
  56                 /* return GENERIC_ALL; */
  57                 return (GENERIC_READ | GENERIC_WRITE);
  58         }
  59
  60         return (READ_CONTROL | FILE_WRITE_ATTRIBUTES | FILE_READ_ATTRIBUTES |
  61                 FILE_WRITE_EA | FILE_APPEND_DATA | FILE_WRITE_DATA |
  62                 FILE_READ_DATA);
  63 }
  64
  65 static u32 cifs_posix_convert_flags(unsigned int flags)
  66 {
  67         u32 posix_flags = 0;
  68
  69         if ((flags & O_ACCMODE) == O_RDONLY)
  70                 posix_flags = SMB_O_RDONLY;
  71         else if ((flags & O_ACCMODE) == O_WRONLY)
  72                 posix_flags = SMB_O_WRONLY;
  73         else if ((flags & O_ACCMODE) == O_RDWR)
  74                 posix_flags = SMB_O_RDWR;
  75
  76         if (flags & O_CREAT) {
  77                 posix_flags |= SMB_O_CREAT;
  78                 if (flags & O_EXCL)
  79                         posix_flags |= SMB_O_EXCL;
  80         } else if (flags & O_EXCL)
  81                 cifs_dbg(FYI, "Application %s pid %d has incorrectly set O_EXCL flag but not O_CREAT on file open. Ignoring O_EXCL\n",
  82                          current->comm, current->tgid);
  83
  84         if (flags & O_TRUNC)
  85                 posix_flags |= SMB_O_TRUNC;
  86         /* be safe and imply O_SYNC for O_DSYNC */
  87         if (flags & O_DSYNC)
  88                 posix_flags |= SMB_O_SYNC;
  89         if (flags & O_DIRECTORY)
  90                 posix_flags |= SMB_O_DIRECTORY;
  91         if (flags & O_NOFOLLOW)
  92                 posix_flags |= SMB_O_NOFOLLOW;
  93         if (flags & O_DIRECT)
  94                 posix_flags |= SMB_O_DIRECT;
  95
  96         return posix_flags;
  97 }
  98
  99 static inline int cifs_get_disposition(unsigned int flags)
 100 {
 101         if ((flags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
 102                 return FILE_CREATE;
 103         else if ((flags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
 104                 return FILE_OVERWRITE_IF;
 105         else if ((flags & O_CREAT) == O_CREAT)
 106                 return FILE_OPEN_IF;
 107         else if ((flags & O_TRUNC) == O_TRUNC)
 108                 return FILE_OVERWRITE;
 109         else
 110                 return FILE_OPEN;
 111 }
 112
 113 int cifs_posix_open(char *full_path, struct inode **pinode,
 114                         struct super_block *sb, int mode, unsigned int f_flags,
 115                         __u32 *poplock, __u16 *pnetfid, unsigned int xid)
 116 {
 117         int rc;
 118         FILE_UNIX_BASIC_INFO *presp_data;
 119         __u32 posix_flags = 0;
 120         struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
 121         struct cifs_fattr fattr;
 122         struct tcon_link *tlink;
 123         struct cifs_tcon *tcon;
 124
 125         cifs_dbg(FYI, "posix open %s\n", full_path);
 126
 127         presp_data = kzalloc(sizeof(FILE_UNIX_BASIC_INFO), GFP_KERNEL);
 128         if (presp_data == NULL)
 129                 return -ENOMEM;
 130
 131         tlink = cifs_sb_tlink(cifs_sb);
 132         if (IS_ERR(tlink)) {
 133                 rc = PTR_ERR(tlink);
 134                 goto posix_open_ret;
 135         }
 136
 137         tcon = tlink_tcon(tlink);
 138         mode &= ~current_umask();
 139
 140         posix_flags = cifs_posix_convert_flags(f_flags);
 141         rc = CIFSPOSIXCreate(xid, tcon, posix_flags, mode, pnetfid, presp_data,
 142                              poplock, full_path, cifs_sb->local_nls,
 143                              cifs_sb->mnt_cifs_flags &
 144                                         CIFS_MOUNT_MAP_SPECIAL_CHR);
 145         cifs_put_tlink(tlink);
 146
 147         if (rc)
 148                 goto posix_open_ret;
 149
 150         if (presp_data->Type == cpu_to_le32(-1))
 151                 goto posix_open_ret; /* open ok, caller does qpathinfo */
 152
 153         if (!pinode)
 154                 goto posix_open_ret; /* caller does not need info */
 155
 156         cifs_unix_basic_to_fattr(&fattr, presp_data, cifs_sb);
 157
 158         /* get new inode and set it up */
 159         if (*pinode == NULL) {
 160                 cifs_fill_uniqueid(sb, &fattr);
 161                 *pinode = cifs_iget(sb, &fattr);
 162                 if (!*pinode) {
 163                         rc = -ENOMEM;
 164                         goto posix_open_ret;
 165                 }
 166         } else {
 167                 cifs_fattr_to_inode(*pinode, &fattr);
 168         }
 169
 170 posix_open_ret:
 171         kfree(presp_data);
 172         return rc;
 173 }
 174
 175 static int
 176 cifs_nt_open(char *full_path, struct inode *inode, struct cifs_sb_info *cifs_sb,
 177              struct cifs_tcon *tcon, unsigned int f_flags, __u32 *oplock,
 178              struct cifs_fid *fid, unsigned int xid)
 179 {
 180         int rc;
 181         int desired_access;
 182         int disposition;
 183         int create_options = CREATE_NOT_DIR;
 184         FILE_ALL_INFO *buf;
 185         struct TCP_Server_Info *server = tcon->ses->server;
 186         struct cifs_open_parms oparms;
 187
 188         if (!server->ops->open)
 189                 return -ENOSYS;
 190
 191         desired_access = cifs_convert_flags(f_flags);
 192
 193 /*********************************************************************
 194  *  open flag mapping table:
 195  *
 196  *      POSIX Flag            CIFS Disposition
 197  *      ----------            ----------------
 198  *      O_CREAT               FILE_OPEN_IF
 199  *      O_CREAT | O_EXCL      FILE_CREATE
 200  *      O_CREAT | O_TRUNC     FILE_OVERWRITE_IF
 201  *      O_TRUNC               FILE_OVERWRITE
 202  *      none of the above     FILE_OPEN
 203  *
 204  *      Note that there is not a direct match between disposition
 205  *      FILE_SUPERSEDE (ie create whether or not file exists although
 206  *      O_CREAT | O_TRUNC is similar but truncates the existing
 207  *      file rather than creating a new file as FILE_SUPERSEDE does
 208  *      (which uses the attributes / metadata passed in on open call)
 209  *?
 210  *?  O_SYNC is a reasonable match to CIFS writethrough flag
 211  *?  and the read write flags match reasonably.  O_LARGEFILE
 212  *?  is irrelevant because largefile support is always used
 213  *?  by this client. Flags O_APPEND, O_DIRECT, O_DIRECTORY,
 214  *       O_FASYNC, O_NOFOLLOW, O_NONBLOCK need further investigation
 215  *********************************************************************/
 216
 217         disposition = cifs_get_disposition(f_flags);
 218
 219         /* BB pass O_SYNC flag through on file attributes .. BB */
 220
 221         buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
 222         if (!buf)
 223                 return -ENOMEM;
 224
 225         if (backup_cred(cifs_sb))
 226                 create_options |= CREATE_OPEN_BACKUP_INTENT;
 227
 228         oparms.tcon = tcon;
 229         oparms.cifs_sb = cifs_sb;
 230         oparms.desired_access = desired_access;
 231         oparms.create_options = create_options;
 232         oparms.disposition = disposition;
 233         oparms.path = full_path;
 234         oparms.fid = fid;
 235         oparms.reconnect = false;
 236
 237         rc = server->ops->open(xid, &oparms, oplock, buf);
 238
 239         if (rc)
 240                 goto out;
 241
 242         if (tcon->unix_ext)
 243                 rc = cifs_get_inode_info_unix(&inode, full_path, inode->i_sb,
 244                                               xid);
 245         else
 246                 rc = cifs_get_inode_info(&inode, full_path, buf, inode->i_sb,
 247                                          xid, fid);
 248
 249 out:
 250         kfree(buf);
 251         return rc;
 252 }
 253
 254 static bool
 255 cifs_has_mand_locks(struct cifsInodeInfo *cinode)
 256 {
 257         struct cifs_fid_locks *cur;
 258         bool has_locks = false;
 259
 260         down_read(&cinode->lock_sem);
 261         list_for_each_entry(cur, &cinode->llist, llist) {
 262                 if (!list_empty(&cur->locks)) {
 263                         has_locks = true;
 264                         break;
 265                 }
 266         }
 267         up_read(&cinode->lock_sem);
 268         return has_locks;
 269 }
 270
 271 struct cifsFileInfo *
 272 cifs_new_fileinfo(struct cifs_fid *fid, struct file *file,
 273                   struct tcon_link *tlink, __u32 oplock)
 274 {
 275         struct dentry *dentry = file->f_path.dentry;
 276         struct inode *inode = dentry->d_inode;
 277         struct cifsInodeInfo *cinode = CIFS_I(inode);
 278         struct cifsFileInfo *cfile;
 279         struct cifs_fid_locks *fdlocks;
 280         struct cifs_tcon *tcon = tlink_tcon(tlink);
 281         struct TCP_Server_Info *server = tcon->ses->server;
 282
 283         cfile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
 284         if (cfile == NULL)
 285                 return cfile;
 286
 287         fdlocks = kzalloc(sizeof(struct cifs_fid_locks), GFP_KERNEL);
 288         if (!fdlocks) {
 289                 kfree(cfile);
 290                 return NULL;
 291         }
 292
 293         INIT_LIST_HEAD(&fdlocks->locks);
 294         fdlocks->cfile = cfile;
 295         cfile->llist = fdlocks;
 296         down_write(&cinode->lock_sem);
 297         list_add(&fdlocks->llist, &cinode->llist);
 298         up_write(&cinode->lock_sem);
 299
 300         cfile->count = 1;
 301         cfile->pid = current->tgid;
 302         cfile->uid = current_fsuid();
 303         cfile->dentry = dget(dentry);
 304         cfile->f_flags = file->f_flags;
 305         cfile->invalidHandle = false;
 306         cfile->tlink = cifs_get_tlink(tlink);
 307         INIT_WORK(&cfile->oplock_break, cifs_oplock_break);
 308         mutex_init(&cfile->fh_mutex);
 309
 310         cifs_sb_active(inode->i_sb);
 311
 312         /*
 313          * If the server returned a read oplock and we have mandatory brlocks,
 314          * set oplock level to None.
 315          */
 316         if (server->ops->is_read_op(oplock) && cifs_has_mand_locks(cinode)) {
 317                 cifs_dbg(FYI, "Reset oplock val from read to None due to mand locks\n");
 318                 oplock = 0;
 319         }
 320
 321         spin_lock(&cifs_file_list_lock);
 322         if (fid->pending_open->oplock != CIFS_OPLOCK_NO_CHANGE && oplock)
 323                 oplock = fid->pending_open->oplock;
 324         list_del(&fid->pending_open->olist);
 325
 326         fid->purge_cache = false;
 327         server->ops->set_fid(cfile, fid, oplock);
 328
 329         list_add(&cfile->tlist, &tcon->openFileList);
 330         /* if readable file instance put first in list*/
 331         if (file->f_mode & FMODE_READ)
 332                 list_add(&cfile->flist, &cinode->openFileList);
 333         else
 334                 list_add_tail(&cfile->flist, &cinode->openFileList);
 335         spin_unlock(&cifs_file_list_lock);
 336
 337         if (fid->purge_cache)
 338                 cifs_zap_mapping(inode);
 339
 340         file->private_data = cfile;
 341         return cfile;
 342 }
 343
 344 struct cifsFileInfo *
 345 cifsFileInfo_get(struct cifsFileInfo *cifs_file)
 346 {
 347         spin_lock(&cifs_file_list_lock);
 348         cifsFileInfo_get_locked(cifs_file);
 349         spin_unlock(&cifs_file_list_lock);
 350         return cifs_file;
 351 }
 352
 353 /*
 354  * Release a reference on the file private data. This may involve closing
 355  * the filehandle out on the server. Must be called without holding
 356  * cifs_file_list_lock.
 357  */
 358 void cifsFileInfo_put(struct cifsFileInfo *cifs_file)
 359 {
 360         struct inode *inode = cifs_file->dentry->d_inode;
 361         struct cifs_tcon *tcon = tlink_tcon(cifs_file->tlink);
 362         struct TCP_Server_Info *server = tcon->ses->server;
 363         struct cifsInodeInfo *cifsi = CIFS_I(inode);
 364         struct super_block *sb = inode->i_sb;
 365         struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
 366         struct cifsLockInfo *li, *tmp;
 367         struct cifs_fid fid;
 368         struct cifs_pending_open open;
 369
 370         spin_lock(&cifs_file_list_lock);
 371         if (--cifs_file->count > 0) {
 372                 spin_unlock(&cifs_file_list_lock);
 373                 return;
 374         }
 375
 376         if (server->ops->get_lease_key)
 377                 server->ops->get_lease_key(inode, &fid);
 378
 379         /* store open in pending opens to make sure we don't miss lease break */
 380         cifs_add_pending_open_locked(&fid, cifs_file->tlink, &open);
 381
 382         /* remove it from the lists */
 383         list_del(&cifs_file->flist);
 384         list_del(&cifs_file->tlist);
 385
 386         if (list_empty(&cifsi->openFileList)) {
 387                 cifs_dbg(FYI, "closing last open instance for inode %p\n",
 388                          cifs_file->dentry->d_inode);
 389                 /*
 390                  * In strict cache mode we need invalidate mapping on the last
 391                  * close  because it may cause a error when we open this file
 392                  * again and get at least level II oplock.
 393                  */
 394                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_STRICT_IO)
 395                         set_bit(CIFS_INO_INVALID_MAPPING, &cifsi->flags);
 396                 cifs_set_oplock_level(cifsi, 0);
 397         }
 398         spin_unlock(&cifs_file_list_lock);
 399
 400         cancel_work_sync(&cifs_file->oplock_break);
 401
 402         if (!tcon->need_reconnect && !cifs_file->invalidHandle) {
 403                 struct TCP_Server_Info *server = tcon->ses->server;
 404                 unsigned int xid;
 405
 406                 xid = get_xid();
 407                 if (server->ops->close)
 408                         server->ops->close(xid, tcon, &cifs_file->fid);
 409                 _free_xid(xid);
 410         }
 411
 412         cifs_del_pending_open(&open);
 413
 414         /*
 415          * Delete any outstanding lock records. We'll lose them when the file
 416          * is closed anyway.
 417          */
 418         down_write(&cifsi->lock_sem);
 419         list_for_each_entry_safe(li, tmp, &cifs_file->llist->locks, llist) {
 420                 list_del(&li->llist);
 421                 cifs_del_lock_waiters(li);
 422                 kfree(li);
 423         }
 424         list_del(&cifs_file->llist->llist);
 425         kfree(cifs_file->llist);
 426         up_write(&cifsi->lock_sem);
 427
 428         cifs_put_tlink(cifs_file->tlink);
 429         dput(cifs_file->dentry);
 430         cifs_sb_deactive(sb);
 431         kfree(cifs_file);
 432 }
 433
 434 int cifs_open(struct inode *inode, struct file *file)
 435
 436 {
 437         int rc = -EACCES;
 438         unsigned int xid;
 439         __u32 oplock;
 440         struct cifs_sb_info *cifs_sb;
 441         struct TCP_Server_Info *server;
 442         struct cifs_tcon *tcon;
 443         struct tcon_link *tlink;
 444         struct cifsFileInfo *cfile = NULL;
 445         char *full_path = NULL;
 446         bool posix_open_ok = false;
 447         struct cifs_fid fid;
 448         struct cifs_pending_open open;
 449
 450         xid = get_xid();
 451
 452         cifs_sb = CIFS_SB(inode->i_sb);
 453         tlink = cifs_sb_tlink(cifs_sb);
 454         if (IS_ERR(tlink)) {
 455                 free_xid(xid);
 456                 return PTR_ERR(tlink);
 457         }
 458         tcon = tlink_tcon(tlink);
 459         server = tcon->ses->server;
 460
 461         full_path = build_path_from_dentry(file->f_path.dentry);
 462         if (full_path == NULL) {
 463                 rc = -ENOMEM;
 464                 goto out;
 465         }
 466
 467         cifs_dbg(FYI, "inode = 0x%p file flags are 0x%x for %s\n",
 468                  inode, file->f_flags, full_path);
 469
 470         if (server->oplocks)
 471                 oplock = REQ_OPLOCK;
 472         else
 473                 oplock = 0;
 474
 475         if (!tcon->broken_posix_open && tcon->unix_ext &&
 476             cap_unix(tcon->ses) && (CIFS_UNIX_POSIX_PATH_OPS_CAP &
 477                                 le64_to_cpu(tcon->fsUnixInfo.Capability))) {
 478                 /* can not refresh inode info since size could be stale */
 479                 rc = cifs_posix_open(full_path, &inode, inode->i_sb,
 480                                 cifs_sb->mnt_file_mode /* ignored */,
 481                                 file->f_flags, &oplock, &fid.netfid, xid);
 482                 if (rc == 0) {
 483                         cifs_dbg(FYI, "posix open succeeded\n");
 484                         posix_open_ok = true;
 485                 } else if ((rc == -EINVAL) || (rc == -EOPNOTSUPP)) {
 486                         if (tcon->ses->serverNOS)
 487                                 cifs_dbg(VFS, "server %s of type %s returned unexpected error on SMB posix open, disabling posix open support. Check if server update available.\n",
 488                                          tcon->ses->serverName,
 489                                          tcon->ses->serverNOS);
 490                         tcon->broken_posix_open = true;
 491                 } else if ((rc != -EIO) && (rc != -EREMOTE) &&
 492                          (rc != -EOPNOTSUPP)) /* path not found or net err */
 493                         goto out;
 494                 /*
 495                  * Else fallthrough to retry open the old way on network i/o
 496                  * or DFS errors.
 497                  */
 498         }
 499
 500         if (server->ops->get_lease_key)
 501                 server->ops->get_lease_key(inode, &fid);
 502
 503         cifs_add_pending_open(&fid, tlink, &open);
 504
 505         if (!posix_open_ok) {
 506                 if (server->ops->get_lease_key)
 507                         server->ops->get_lease_key(inode, &fid);
 508
 509                 rc = cifs_nt_open(full_path, inode, cifs_sb, tcon,
 510                                   file->f_flags, &oplock, &fid, xid);
 511                 if (rc) {
 512                         cifs_del_pending_open(&open);
 513                         goto out;
 514                 }
 515         }
 516
 517         cfile = cifs_new_fileinfo(&fid, file, tlink, oplock);
 518         if (cfile == NULL) {
 519                 if (server->ops->close)
 520                         server->ops->close(xid, tcon, &fid);
 521                 cifs_del_pending_open(&open);
 522                 rc = -ENOMEM;
 523                 goto out;
 524         }
 525
 526         cifs_fscache_set_inode_cookie(inode, file);
 527
 528         if ((oplock & CIFS_CREATE_ACTION) && !posix_open_ok && tcon->unix_ext) {
 529                 /*
 530                  * Time to set mode which we can not set earlier due to
 531                  * problems creating new read-only files.
 532                  */
 533                 struct cifs_unix_set_info_args args = {
 534                         .mode   = inode->i_mode,
 535                         .uid    = INVALID_UID, /* no change */
 536                         .gid    = INVALID_GID, /* no change */
 537                         .ctime  = NO_CHANGE_64,
 538                         .atime  = NO_CHANGE_64,
 539                         .mtime  = NO_CHANGE_64,
 540                         .device = 0,
 541                 };
 542                 CIFSSMBUnixSetFileInfo(xid, tcon, &args, fid.netfid,
 543                                        cfile->pid);
 544         }
 545
 546 out:
 547         kfree(full_path);
 548         free_xid(xid);
 549         cifs_put_tlink(tlink);
 550         return rc;
 551 }
 552
 553 static int cifs_push_posix_locks(struct cifsFileInfo *cfile);
 554
 555 /*
 556  * Try to reacquire byte range locks that were released when session
 557  * to server was lost.
 558  */
 559 static int
 560 cifs_relock_file(struct cifsFileInfo *cfile)
 561 {
 562         struct cifs_sb_info *cifs_sb = CIFS_SB(cfile->dentry->d_sb);
 563         struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
 564         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
 565         int rc = 0;
 566
 567         down_read(&cinode->lock_sem);
 568         if (cinode->can_cache_brlcks) {
 569                 /* can cache locks - no need to relock */
 570                 up_read(&cinode->lock_sem);
 571                 return rc;
 572         }
 573
 574         if (cap_unix(tcon->ses) &&
 575             (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
 576             ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
 577                 rc = cifs_push_posix_locks(cfile);
 578         else
 579                 rc = tcon->ses->server->ops->push_mand_locks(cfile);
 580
 581         up_read(&cinode->lock_sem);
 582         return rc;
 583 }
 584
 585 static int
 586 cifs_reopen_file(struct cifsFileInfo *cfile, bool can_flush)
 587 {
 588         int rc = -EACCES;
 589         unsigned int xid;
 590         __u32 oplock;
 591         struct cifs_sb_info *cifs_sb;
 592         struct cifs_tcon *tcon;
 593         struct TCP_Server_Info *server;
 594         struct cifsInodeInfo *cinode;
 595         struct inode *inode;
 596         char *full_path = NULL;
 597         int desired_access;
 598         int disposition = FILE_OPEN;
 599         int create_options = CREATE_NOT_DIR;
 600         struct cifs_open_parms oparms;
 601
 602         xid = get_xid();
 603         mutex_lock(&cfile->fh_mutex);
 604         if (!cfile->invalidHandle) {
 605                 mutex_unlock(&cfile->fh_mutex);
 606                 rc = 0;
 607                 free_xid(xid);
 608                 return rc;
 609         }
 610
 611         inode = cfile->dentry->d_inode;
 612         cifs_sb = CIFS_SB(inode->i_sb);
 613         tcon = tlink_tcon(cfile->tlink);
 614         server = tcon->ses->server;
 615
 616         /*
 617          * Can not grab rename sem here because various ops, including those
 618          * that already have the rename sem can end up causing writepage to get
 619          * called and if the server was down that means we end up here, and we
 620          * can never tell if the caller already has the rename_sem.
 621          */
 622         full_path = build_path_from_dentry(cfile->dentry);
 623         if (full_path == NULL) {
 624                 rc = -ENOMEM;
 625                 mutex_unlock(&cfile->fh_mutex);
 626                 free_xid(xid);
 627                 return rc;
 628         }
 629
 630         cifs_dbg(FYI, "inode = 0x%p file flags 0x%x for %s\n",
 631                  inode, cfile->f_flags, full_path);
 632
 633         if (tcon->ses->server->oplocks)
 634                 oplock = REQ_OPLOCK;
 635         else
 636                 oplock = 0;
 637
 638         if (tcon->unix_ext && cap_unix(tcon->ses) &&
 639             (CIFS_UNIX_POSIX_PATH_OPS_CAP &
 640                                 le64_to_cpu(tcon->fsUnixInfo.Capability))) {
 641                 /*
 642                  * O_CREAT, O_EXCL and O_TRUNC already had their effect on the
 643                  * original open. Must mask them off for a reopen.
 644                  */
 645                 unsigned int oflags = cfile->f_flags &
 646                                                 ~(O_CREAT | O_EXCL | O_TRUNC);
 647
 648                 rc = cifs_posix_open(full_path, NULL, inode->i_sb,
 649                                      cifs_sb->mnt_file_mode /* ignored */,
 650                                      oflags, &oplock, &cfile->fid.netfid, xid);
 651                 if (rc == 0) {
 652                         cifs_dbg(FYI, "posix reopen succeeded\n");
 653                         oparms.reconnect = true;
 654                         goto reopen_success;
 655                 }
 656                 /*
 657                  * fallthrough to retry open the old way on errors, especially
 658                  * in the reconnect path it is important to retry hard
 659                  */
 660         }
 661
 662         desired_access = cifs_convert_flags(cfile->f_flags);
 663
 664         if (backup_cred(cifs_sb))
 665                 create_options |= CREATE_OPEN_BACKUP_INTENT;
 666
 667         if (server->ops->get_lease_key)
 668                 server->ops->get_lease_key(inode, &cfile->fid);
 669
 670         oparms.tcon = tcon;
 671         oparms.cifs_sb = cifs_sb;
 672         oparms.desired_access = desired_access;
 673         oparms.create_options = create_options;
 674         oparms.disposition = disposition;
 675         oparms.path = full_path;
 676         oparms.fid = &cfile->fid;
 677         oparms.reconnect = true;
 678
 679         /*
 680          * Can not refresh inode by passing in file_info buf to be returned by
 681          * ops->open and then calling get_inode_info with returned buf since
 682          * file might have write behind data that needs to be flushed and server
 683          * version of file size can be stale. If we knew for sure that inode was
 684          * not dirty locally we could do this.
 685          */
 686         rc = server->ops->open(xid, &oparms, &oplock, NULL);
 687         if (rc == -ENOENT && oparms.reconnect == false) {
 688                 /* durable handle timeout is expired - open the file again */
 689                 rc = server->ops->open(xid, &oparms, &oplock, NULL);
 690                 /* indicate that we need to relock the file */
 691                 oparms.reconnect = true;
 692         }
 693
 694         if (rc) {
 695                 mutex_unlock(&cfile->fh_mutex);
 696                 cifs_dbg(FYI, "cifs_reopen returned 0x%x\n", rc);
 697                 cifs_dbg(FYI, "oplock: %d\n", oplock);
 698                 goto reopen_error_exit;
 699         }
 700
 701 reopen_success:
 702         cfile->invalidHandle = false;
 703         mutex_unlock(&cfile->fh_mutex);
 704         cinode = CIFS_I(inode);
 705
 706         if (can_flush) {
 707                 rc = filemap_write_and_wait(inode->i_mapping);
 708                 mapping_set_error(inode->i_mapping, rc);
 709
 710                 if (tcon->unix_ext)
 711                         rc = cifs_get_inode_info_unix(&inode, full_path,
 712                                                       inode->i_sb, xid);
 713                 else
 714                         rc = cifs_get_inode_info(&inode, full_path, NULL,
 715                                                  inode->i_sb, xid, NULL);
 716         }
 717         /*
 718          * Else we are writing out data to server already and could deadlock if
 719          * we tried to flush data, and since we do not know if we have data that
 720          * would invalidate the current end of file on the server we can not go
 721          * to the server to get the new inode info.
 722          */
 723
 724         server->ops->set_fid(cfile, &cfile->fid, oplock);
 725         if (oparms.reconnect)
 726                 cifs_relock_file(cfile);
 727
 728 reopen_error_exit:
 729         kfree(full_path);
 730         free_xid(xid);
 731         return rc;
 732 }
 733
 734 int cifs_close(struct inode *inode, struct file *file)
 735 {
 736         if (file->private_data != NULL) {
 737                 cifsFileInfo_put(file->private_data);
 738                 file->private_data = NULL;
 739         }
 740
 741         /* return code from the ->release op is always ignored */
 742         return 0;
 743 }
 744
 745 int cifs_closedir(struct inode *inode, struct file *file)
 746 {
 747         int rc = 0;
 748         unsigned int xid;
 749         struct cifsFileInfo *cfile = file->private_data;
 750         struct cifs_tcon *tcon;
 751         struct TCP_Server_Info *server;
 752         char *buf;
 753
 754         cifs_dbg(FYI, "Closedir inode = 0x%p\n", inode);
 755
 756         if (cfile == NULL)
 757                 return rc;
 758
 759         xid = get_xid();
 760         tcon = tlink_tcon(cfile->tlink);
 761         server = tcon->ses->server;
 762
 763         cifs_dbg(FYI, "Freeing private data in close dir\n");
 764         spin_lock(&cifs_file_list_lock);
 765         if (!cfile->srch_inf.endOfSearch && !cfile->invalidHandle) {
 766                 cfile->invalidHandle = true;
 767                 spin_unlock(&cifs_file_list_lock);
 768                 if (server->ops->close_dir)
 769                         rc = server->ops->close_dir(xid, tcon, &cfile->fid);
 770                 else
 771                         rc = -ENOSYS;
 772                 cifs_dbg(FYI, "Closing uncompleted readdir with rc %d\n", rc);
 773                 /* not much we can do if it fails anyway, ignore rc */
 774                 rc = 0;
 775         } else
 776                 spin_unlock(&cifs_file_list_lock);
 777
 778         buf = cfile->srch_inf.ntwrk_buf_start;
 779         if (buf) {
 780                 cifs_dbg(FYI, "closedir free smb buf in srch struct\n");
 781                 cfile->srch_inf.ntwrk_buf_start = NULL;
 782                 if (cfile->srch_inf.smallBuf)
 783                         cifs_small_buf_release(buf);
 784                 else
 785                         cifs_buf_release(buf);
 786         }
 787
 788         cifs_put_tlink(cfile->tlink);
 789         kfree(file->private_data);
 790         file->private_data = NULL;
 791         /* BB can we lock the filestruct while this is going on? */
 792         free_xid(xid);
 793         return rc;
 794 }
 795
 796 static struct cifsLockInfo *
 797 cifs_lock_init(__u64 offset, __u64 length, __u8 type)
 798 {
 799         struct cifsLockInfo *lock =
 800                 kmalloc(sizeof(struct cifsLockInfo), GFP_KERNEL);
 801         if (!lock)
 802                 return lock;
 803         lock->offset = offset;
 804         lock->length = length;
 805         lock->type = type;
 806         lock->pid = current->tgid;
 807         INIT_LIST_HEAD(&lock->blist);
 808         init_waitqueue_head(&lock->block_q);
 809         return lock;
 810 }
 811
 812 void
 813 cifs_del_lock_waiters(struct cifsLockInfo *lock)
 814 {
 815         struct cifsLockInfo *li, *tmp;
 816         list_for_each_entry_safe(li, tmp, &lock->blist, blist) {
 817                 list_del_init(&li->blist);
 818                 wake_up(&li->block_q);
 819         }
 820 }
 821
 822 #define CIFS_LOCK_OP    0
 823 #define CIFS_READ_OP    1
 824 #define CIFS_WRITE_OP   2
 825
 826 /* @rw_check : 0 - no op, 1 - read, 2 - write */
 827 static bool
 828 cifs_find_fid_lock_conflict(struct cifs_fid_locks *fdlocks, __u64 offset,
 829                             __u64 length, __u8 type, struct cifsFileInfo *cfile,
 830                             struct cifsLockInfo **conf_lock, int rw_check)
 831 {
 832         struct cifsLockInfo *li;
 833         struct cifsFileInfo *cur_cfile = fdlocks->cfile;
 834         struct TCP_Server_Info *server = tlink_tcon(cfile->tlink)->ses->server;
 835
 836         list_for_each_entry(li, &fdlocks->locks, llist) {
 837                 if (offset + length <= li->offset ||
 838                     offset >= li->offset + li->length)
 839                         continue;
 840                 if (rw_check != CIFS_LOCK_OP && current->tgid == li->pid &&
 841                     server->ops->compare_fids(cfile, cur_cfile)) {
 842                         /* shared lock prevents write op through the same fid */
 843                         if (!(li->type & server->vals->shared_lock_type) ||
 844                             rw_check != CIFS_WRITE_OP)
 845                                 continue;
 846                 }
 847                 if ((type & server->vals->shared_lock_type) &&
 848                     ((server->ops->compare_fids(cfile, cur_cfile) &&
 849                      current->tgid == li->pid) || type == li->type))
 850                         continue;
 851                 if (conf_lock)
 852                         *conf_lock = li;
 853                 return true;
 854         }
 855         return false;
 856 }
 857
 858 bool
 859 cifs_find_lock_conflict(struct cifsFileInfo *cfile, __u64 offset, __u64 length,
 860                         __u8 type, struct cifsLockInfo **conf_lock,
 861                         int rw_check)
 862 {
 863         bool rc = false;
 864         struct cifs_fid_locks *cur;
 865         struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
 866
 867         list_for_each_entry(cur, &cinode->llist, llist) {
 868                 rc = cifs_find_fid_lock_conflict(cur, offset, length, type,
 869                                                  cfile, conf_lock, rw_check);
 870                 if (rc)
 871                         break;
 872         }
 873
 874         return rc;
 875 }
 876
 877 /*
 878  * Check if there is another lock that prevents us to set the lock (mandatory
 879  * style). If such a lock exists, update the flock structure with its
 880  * properties. Otherwise, set the flock type to F_UNLCK if we can cache brlocks
 881  * or leave it the same if we can't. Returns 0 if we don't need to request to
 882  * the server or 1 otherwise.
 883  */
 884 static int
 885 cifs_lock_test(struct cifsFileInfo *cfile, __u64 offset, __u64 length,
 886                __u8 type, struct file_lock *flock)
 887 {
 888         int rc = 0;
 889         struct cifsLockInfo *conf_lock;
 890         struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
 891         struct TCP_Server_Info *server = tlink_tcon(cfile->tlink)->ses->server;
 892         bool exist;
 893
 894         down_read(&cinode->lock_sem);
 895
 896         exist = cifs_find_lock_conflict(cfile, offset, length, type,
 897                                         &conf_lock, CIFS_LOCK_OP);
 898         if (exist) {
 899                 flock->fl_start = conf_lock->offset;
 900                 flock->fl_end = conf_lock->offset + conf_lock->length - 1;
 901                 flock->fl_pid = conf_lock->pid;
 902                 if (conf_lock->type & server->vals->shared_lock_type)
 903                         flock->fl_type = F_RDLCK;
 904                 else
 905                         flock->fl_type = F_WRLCK;
 906         } else if (!cinode->can_cache_brlcks)
 907                 rc = 1;
 908         else
 909                 flock->fl_type = F_UNLCK;
 910
 911         up_read(&cinode->lock_sem);
 912         return rc;
 913 }
 914
 915 static void
 916 cifs_lock_add(struct cifsFileInfo *cfile, struct cifsLockInfo *lock)
 917 {
 918         struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
 919         down_write(&cinode->lock_sem);
 920         list_add_tail(&lock->llist, &cfile->llist->locks);
 921         up_write(&cinode->lock_sem);
 922 }
 923
 924 /*
 925  * Set the byte-range lock (mandatory style). Returns:
 926  * 1) 0, if we set the lock and don't need to request to the server;
 927  * 2) 1, if no locks prevent us but we need to request to the server;
 928  * 3) -EACCESS, if there is a lock that prevents us and wait is false.
 929  */
 930 static int
 931 cifs_lock_add_if(struct cifsFileInfo *cfile, struct cifsLockInfo *lock,
 932                  bool wait)
 933 {
 934         struct cifsLockInfo *conf_lock;
 935         struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
 936         bool exist;
 937         int rc = 0;
 938
 939 try_again:
 940         exist = false;
 941         down_write(&cinode->lock_sem);
 942
 943         exist = cifs_find_lock_conflict(cfile, lock->offset, lock->length,
 944                                         lock->type, &conf_lock, CIFS_LOCK_OP);
 945         if (!exist && cinode->can_cache_brlcks) {
 946                 list_add_tail(&lock->llist, &cfile->llist->locks);
 947                 up_write(&cinode->lock_sem);
 948                 return rc;
 949         }
 950
 951         if (!exist)
 952                 rc = 1;
 953         else if (!wait)
 954                 rc = -EACCES;
 955         else {
 956                 list_add_tail(&lock->blist, &conf_lock->blist);
 957                 up_write(&cinode->lock_sem);
 958                 rc = wait_event_interruptible(lock->block_q,
 959                                         (lock->blist.prev == &lock->blist) &&
 960                                         (lock->blist.next == &lock->blist));
 961                 if (!rc)
 962                         goto try_again;
 963                 down_write(&cinode->lock_sem);
 964                 list_del_init(&lock->blist);
 965         }
 966
 967         up_write(&cinode->lock_sem);
 968         return rc;
 969 }
 970
 971 /*
 972  * Check if there is another lock that prevents us to set the lock (posix
 973  * style). If such a lock exists, update the flock structure with its
 974  * properties. Otherwise, set the flock type to F_UNLCK if we can cache brlocks
 975  * or leave it the same if we can't. Returns 0 if we don't need to request to
 976  * the server or 1 otherwise.
 977  */
 978 static int
 979 cifs_posix_lock_test(struct file *file, struct file_lock *flock)
 980 {
 981         int rc = 0;
 982         struct cifsInodeInfo *cinode = CIFS_I(file_inode(file));
 983         unsigned char saved_type = flock->fl_type;
 984
 985         if ((flock->fl_flags & FL_POSIX) == 0)
 986                 return 1;
 987
 988         down_read(&cinode->lock_sem);
 989         posix_test_lock(file, flock);
 990
 991         if (flock->fl_type == F_UNLCK && !cinode->can_cache_brlcks) {
 992                 flock->fl_type = saved_type;
 993                 rc = 1;
 994         }
 995
 996         up_read(&cinode->lock_sem);
 997         return rc;
 998 }
 999
1000 /*
1001  * Set the byte-range lock (posix style). Returns:
1002  * 1) 0, if we set the lock and don't need to request to the server;
1003  * 2) 1, if we need to request to the server;
1004  * 3) <0, if the error occurs while setting the lock.
1005  */
1006 static int
1007 cifs_posix_lock_set(struct file *file, struct file_lock *flock)
1008 {
1009         struct cifsInodeInfo *cinode = CIFS_I(file_inode(file));
1010         int rc = 1;
1011
1012         if ((flock->fl_flags & FL_POSIX) == 0)
1013                 return rc;
1014
1015 try_again:
1016         down_write(&cinode->lock_sem);
1017         if (!cinode->can_cache_brlcks) {
1018                 up_write(&cinode->lock_sem);
1019                 return rc;
1020         }
1021
1022         rc = posix_lock_file(file, flock, NULL);
1023         up_write(&cinode->lock_sem);
1024         if (rc == FILE_LOCK_DEFERRED) {
1025                 rc = wait_event_interruptible(flock->fl_wait, !flock->fl_next);
1026                 if (!rc)
1027                         goto try_again;
1028                 posix_unblock_lock(flock);
1029         }
1030         return rc;
1031 }
1032
1033 int
1034 cifs_push_mandatory_locks(struct cifsFileInfo *cfile)
1035 {
1036         unsigned int xid;
1037         int rc = 0, stored_rc;
1038         struct cifsLockInfo *li, *tmp;
1039         struct cifs_tcon *tcon;
1040         unsigned int num, max_num, max_buf;
1041         LOCKING_ANDX_RANGE *buf, *cur;
1042         int types[] = {LOCKING_ANDX_LARGE_FILES,
1043                        LOCKING_ANDX_SHARED_LOCK | LOCKING_ANDX_LARGE_FILES};
1044         int i;
1045
1046         xid = get_xid();
1047         tcon = tlink_tcon(cfile->tlink);
1048
1049         /*
1050          * Accessing maxBuf is racy with cifs_reconnect - need to store value
1051          * and check it for zero before using.
1052          */
1053         max_buf = tcon->ses->server->maxBuf;
1054         if (!max_buf) {
1055                 free_xid(xid);
1056                 return -EINVAL;
1057         }
1058
1059         max_num = (max_buf - sizeof(struct smb_hdr)) /
1060                                                 sizeof(LOCKING_ANDX_RANGE);
1061         buf = kzalloc(max_num * sizeof(LOCKING_ANDX_RANGE), GFP_KERNEL);
1062         if (!buf) {
1063                 free_xid(xid);
1064                 return -ENOMEM;
1065         }
1066
1067         for (i = 0; i < 2; i++) {
1068                 cur = buf;
1069                 num = 0;
1070                 list_for_each_entry_safe(li, tmp, &cfile->llist->locks, llist) {
1071                         if (li->type != types[i])
1072                                 continue;
1073                         cur->Pid = cpu_to_le16(li->pid);
1074                         cur->LengthLow = cpu_to_le32((u32)li->length);
1075                         cur->LengthHigh = cpu_to_le32((u32)(li->length>>32));
1076                         cur->OffsetLow = cpu_to_le32((u32)li->offset);
1077                         cur->OffsetHigh = cpu_to_le32((u32)(li->offset>>32));
1078                         if (++num == max_num) {
1079                                 stored_rc = cifs_lockv(xid, tcon,
1080                                                        cfile->fid.netfid,
1081                                                        (__u8)li->type, 0, num,
1082                                                        buf);
1083                                 if (stored_rc)
1084                                         rc = stored_rc;
1085                                 cur = buf;
1086                                 num = 0;
1087                         } else
1088                                 cur++;
1089                 }
1090
1091                 if (num) {
1092                         stored_rc = cifs_lockv(xid, tcon, cfile->fid.netfid,
1093                                                (__u8)types[i], 0, num, buf);
1094                         if (stored_rc)
1095                                 rc = stored_rc;
1096                 }
1097         }
1098
1099         kfree(buf);
1100         free_xid(xid);
1101         return rc;
1102 }
1103
1104 /* copied from fs/locks.c with a name change */
1105 #define cifs_for_each_lock(inode, lockp) \
1106         for (lockp = &inode->i_flock; *lockp != NULL; \
1107              lockp = &(*lockp)->fl_next)
1108
1109 struct lock_to_push {
1110         struct list_head llist;
1111         __u64 offset;
1112         __u64 length;
1113         __u32 pid;
1114         __u16 netfid;
1115         __u8 type;
1116 };
1117
1118 static int
1119 cifs_push_posix_locks(struct cifsFileInfo *cfile)
1120 {
1121         struct inode *inode = cfile->dentry->d_inode;
1122         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1123         struct file_lock *flock, **before;
1124         unsigned int count = 0, i = 0;
1125         int rc = 0, xid, type;
1126         struct list_head locks_to_send, *el;
1127         struct lock_to_push *lck, *tmp;
1128         __u64 length;
1129
1130         xid = get_xid();
1131
1132         spin_lock(&inode->i_lock);
1133         cifs_for_each_lock(inode, before) {
1134                 if ((*before)->fl_flags & FL_POSIX)
1135                         count++;
1136         }
1137         spin_unlock(&inode->i_lock);
1138
1139         INIT_LIST_HEAD(&locks_to_send);
1140
1141         /*
1142          * Allocating count locks is enough because no FL_POSIX locks can be
1143          * added to the list while we are holding cinode->lock_sem that
1144          * protects locking operations of this inode.
1145          */
1146         for (; i < count; i++) {
1147                 lck = kmalloc(sizeof(struct lock_to_push), GFP_KERNEL);
1148                 if (!lck) {
1149                         rc = -ENOMEM;
1150                         goto err_out;
1151                 }
1152                 list_add_tail(&lck->llist, &locks_to_send);
1153         }
1154
1155         el = locks_to_send.next;
1156         spin_lock(&inode->i_lock);
1157         cifs_for_each_lock(inode, before) {
1158                 flock = *before;
1159                 if ((flock->fl_flags & FL_POSIX) == 0)
1160                         continue;
1161                 if (el == &locks_to_send) {
1162                         /*
1163                          * The list ended. We don't have enough allocated
1164                          * structures - something is really wrong.
1165                          */
1166                         cifs_dbg(VFS, "Can't push all brlocks!\n");
1167                         break;
1168                 }
1169                 length = 1 + flock->fl_end - flock->fl_start;
1170                 if (flock->fl_type == F_RDLCK || flock->fl_type == F_SHLCK)
1171                         type = CIFS_RDLCK;
1172                 else
1173                         type = CIFS_WRLCK;
1174                 lck = list_entry(el, struct lock_to_push, llist);
1175                 lck->pid = flock->fl_pid;
1176                 lck->netfid = cfile->fid.netfid;
1177                 lck->length = length;
1178                 lck->type = type;
1179                 lck->offset = flock->fl_start;
1180                 el = el->next;
1181         }
1182         spin_unlock(&inode->i_lock);
1183
1184         list_for_each_entry_safe(lck, tmp, &locks_to_send, llist) {
1185                 int stored_rc;
1186
1187                 stored_rc = CIFSSMBPosixLock(xid, tcon, lck->netfid, lck->pid,
1188                                              lck->offset, lck->length, NULL,
1189                                              lck->type, 0);
1190                 if (stored_rc)
1191                         rc = stored_rc;
1192                 list_del(&lck->llist);
1193                 kfree(lck);
1194         }
1195
1196 out:
1197         free_xid(xid);
1198         return rc;
1199 err_out:
1200         list_for_each_entry_safe(lck, tmp, &locks_to_send, llist) {
1201                 list_del(&lck->llist);
1202                 kfree(lck);
1203         }
1204         goto out;
1205 }
1206
1207 static int
1208 cifs_push_locks(struct cifsFileInfo *cfile)
1209 {
1210         struct cifs_sb_info *cifs_sb = CIFS_SB(cfile->dentry->d_sb);
1211         struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
1212         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1213         int rc = 0;
1214
1215         /* we are going to update can_cache_brlcks here - need a write access */
1216         down_write(&cinode->lock_sem);
1217         if (!cinode->can_cache_brlcks) {
1218                 up_write(&cinode->lock_sem);
1219                 return rc;
1220         }
1221
1222         if (cap_unix(tcon->ses) &&
1223             (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
1224             ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
1225                 rc = cifs_push_posix_locks(cfile);
1226         else
1227                 rc = tcon->ses->server->ops->push_mand_locks(cfile);
1228
1229         cinode->can_cache_brlcks = false;
1230         up_write(&cinode->lock_sem);
1231         return rc;
1232 }
1233
1234 static void
1235 cifs_read_flock(struct file_lock *flock, __u32 *type, int *lock, int *unlock,
1236                 bool *wait_flag, struct TCP_Server_Info *server)
1237 {
1238         if (flock->fl_flags & FL_POSIX)
1239                 cifs_dbg(FYI, "Posix\n");
1240         if (flock->fl_flags & FL_FLOCK)
1241                 cifs_dbg(FYI, "Flock\n");
1242         if (flock->fl_flags & FL_SLEEP) {
1243                 cifs_dbg(FYI, "Blocking lock\n");
1244                 *wait_flag = true;
1245         }
1246         if (flock->fl_flags & FL_ACCESS)
1247                 cifs_dbg(FYI, "Process suspended by mandatory locking - not implemented yet\n");
1248         if (flock->fl_flags & FL_LEASE)
1249                 cifs_dbg(FYI, "Lease on file - not implemented yet\n");
1250         if (flock->fl_flags &
1251             (~(FL_POSIX | FL_FLOCK | FL_SLEEP |
1252                FL_ACCESS | FL_LEASE | FL_CLOSE)))
1253                 cifs_dbg(FYI, "Unknown lock flags 0x%x\n", flock->fl_flags);
1254
1255         *type = server->vals->large_lock_type;
1256         if (flock->fl_type == F_WRLCK) {
1257                 cifs_dbg(FYI, "F_WRLCK\n");
1258                 *type |= server->vals->exclusive_lock_type;
1259                 *lock = 1;
1260         } else if (flock->fl_type == F_UNLCK) {
1261                 cifs_dbg(FYI, "F_UNLCK\n");
1262                 *type |= server->vals->unlock_lock_type;
1263                 *unlock = 1;
1264                 /* Check if unlock includes more than one lock range */
1265         } else if (flock->fl_type == F_RDLCK) {
1266                 cifs_dbg(FYI, "F_RDLCK\n");
1267                 *type |= server->vals->shared_lock_type;
1268                 *lock = 1;
1269         } else if (flock->fl_type == F_EXLCK) {
1270                 cifs_dbg(FYI, "F_EXLCK\n");
1271                 *type |= server->vals->exclusive_lock_type;
1272                 *lock = 1;
1273         } else if (flock->fl_type == F_SHLCK) {
1274                 cifs_dbg(FYI, "F_SHLCK\n");
1275                 *type |= server->vals->shared_lock_type;
1276                 *lock = 1;
1277         } else
1278                 cifs_dbg(FYI, "Unknown type of lock\n");
1279 }
1280
1281 static int
1282 cifs_getlk(struct file *file, struct file_lock *flock, __u32 type,
1283            bool wait_flag, bool posix_lck, unsigned int xid)
1284 {
1285         int rc = 0;
1286         __u64 length = 1 + flock->fl_end - flock->fl_start;
1287         struct cifsFileInfo *cfile = (struct cifsFileInfo *)file->private_data;
1288         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1289         struct TCP_Server_Info *server = tcon->ses->server;
1290         __u16 netfid = cfile->fid.netfid;
1291
1292         if (posix_lck) {
1293                 int posix_lock_type;
1294
1295                 rc = cifs_posix_lock_test(file, flock);
1296                 if (!rc)
1297                         return rc;
1298
1299                 if (type & server->vals->shared_lock_type)
1300                         posix_lock_type = CIFS_RDLCK;
1301                 else
1302                         posix_lock_type = CIFS_WRLCK;
1303                 rc = CIFSSMBPosixLock(xid, tcon, netfid, current->tgid,
1304                                       flock->fl_start, length, flock,
1305                                       posix_lock_type, wait_flag);
1306                 return rc;
1307         }
1308
1309         rc = cifs_lock_test(cfile, flock->fl_start, length, type, flock);
1310         if (!rc)
1311                 return rc;
1312
1313         /* BB we could chain these into one lock request BB */
1314         rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length, type,
1315                                     1, 0, false);
1316         if (rc == 0) {
1317                 rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length,
1318                                             type, 0, 1, false);
1319                 flock->fl_type = F_UNLCK;
1320                 if (rc != 0)
1321                         cifs_dbg(VFS, "Error unlocking previously locked range %d during test of lock\n",
1322                                  rc);
1323                 return 0;
1324         }
1325
1326         if (type & server->vals->shared_lock_type) {
1327                 flock->fl_type = F_WRLCK;
1328                 return 0;
1329         }
1330
1331         type &= ~server->vals->exclusive_lock_type;
1332
1333         rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length,
1334                                     type | server->vals->shared_lock_type,
1335                                     1, 0, false);
1336         if (rc == 0) {
1337                 rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length,
1338                         type | server->vals->shared_lock_type, 0, 1, false);
1339                 flock->fl_type = F_RDLCK;
1340                 if (rc != 0)
1341                         cifs_dbg(VFS, "Error unlocking previously locked range %d during test of lock\n",
1342                                  rc);
1343         } else
1344                 flock->fl_type = F_WRLCK;
1345
1346         return 0;
1347 }
1348
1349 void
1350 cifs_move_llist(struct list_head *source, struct list_head *dest)
1351 {
1352         struct list_head *li, *tmp;
1353         list_for_each_safe(li, tmp, source)
1354                 list_move(li, dest);
1355 }
1356
1357 void
1358 cifs_free_llist(struct list_head *llist)
1359 {
1360         struct cifsLockInfo *li, *tmp;
1361         list_for_each_entry_safe(li, tmp, llist, llist) {
1362                 cifs_del_lock_waiters(li);
1363                 list_del(&li->llist);
1364                 kfree(li);
1365         }
1366 }
1367
1368 int
1369 cifs_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock,
1370                   unsigned int xid)
1371 {
1372         int rc = 0, stored_rc;
1373         int types[] = {LOCKING_ANDX_LARGE_FILES,
1374                        LOCKING_ANDX_SHARED_LOCK | LOCKING_ANDX_LARGE_FILES};
1375         unsigned int i;
1376         unsigned int max_num, num, max_buf;
1377         LOCKING_ANDX_RANGE *buf, *cur;
1378         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1379         struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
1380         struct cifsLockInfo *li, *tmp;
1381         __u64 length = 1 + flock->fl_end - flock->fl_start;
1382         struct list_head tmp_llist;
1383
1384         INIT_LIST_HEAD(&tmp_llist);
1385
1386         /*
1387          * Accessing maxBuf is racy with cifs_reconnect - need to store value
1388          * and check it for zero before using.
1389          */
1390         max_buf = tcon->ses->server->maxBuf;
1391         if (!max_buf)
1392                 return -EINVAL;
1393
1394         max_num = (max_buf - sizeof(struct smb_hdr)) /
1395                                                 sizeof(LOCKING_ANDX_RANGE);
1396         buf = kzalloc(max_num * sizeof(LOCKING_ANDX_RANGE), GFP_KERNEL);
1397         if (!buf)
1398                 return -ENOMEM;
1399
1400         down_write(&cinode->lock_sem);
1401         for (i = 0; i < 2; i++) {
1402                 cur = buf;
1403                 num = 0;
1404                 list_for_each_entry_safe(li, tmp, &cfile->llist->locks, llist) {
1405                         if (flock->fl_start > li->offset ||
1406                             (flock->fl_start + length) <
1407                             (li->offset + li->length))
1408                                 continue;
1409                         if (current->tgid != li->pid)
1410                                 continue;
1411                         if (types[i] != li->type)
1412                                 continue;
1413                         if (cinode->can_cache_brlcks) {
1414                                 /*
1415                                  * We can cache brlock requests - simply remove
1416                                  * a lock from the file's list.
1417                                  */
1418                                 list_del(&li->llist);
1419                                 cifs_del_lock_waiters(li);
1420                                 kfree(li);
1421                                 continue;
1422                         }
1423                         cur->Pid = cpu_to_le16(li->pid);
1424                         cur->LengthLow = cpu_to_le32((u32)li->length);
1425                         cur->LengthHigh = cpu_to_le32((u32)(li->length>>32));
1426                         cur->OffsetLow = cpu_to_le32((u32)li->offset);
1427                         cur->OffsetHigh = cpu_to_le32((u32)(li->offset>>32));
1428                         /*
1429                          * We need to save a lock here to let us add it again to
1430                          * the file's list if the unlock range request fails on
1431                          * the server.
1432                          */
1433                         list_move(&li->llist, &tmp_llist);
1434                         if (++num == max_num) {
1435                                 stored_rc = cifs_lockv(xid, tcon,
1436                                                        cfile->fid.netfid,
1437                                                        li->type, num, 0, buf);
1438                                 if (stored_rc) {
1439                                         /*
1440                                          * We failed on the unlock range
1441                                          * request - add all locks from the tmp
1442                                          * list to the head of the file's list.
1443                                          */
1444                                         cifs_move_llist(&tmp_llist,
1445                                                         &cfile->llist->locks);
1446                                         rc = stored_rc;
1447                                 } else
1448                                         /*
1449                                          * The unlock range request succeed -
1450                                          * free the tmp list.
1451                                          */
1452                                         cifs_free_llist(&tmp_llist);
1453                                 cur = buf;
1454                                 num = 0;
1455                         } else
1456                                 cur++;
1457                 }
1458                 if (num) {
1459                         stored_rc = cifs_lockv(xid, tcon, cfile->fid.netfid,
1460                                                types[i], num, 0, buf);
1461                         if (stored_rc) {
1462                                 cifs_move_llist(&tmp_llist,
1463                                                 &cfile->llist->locks);
1464                                 rc = stored_rc;
1465                         } else
1466                                 cifs_free_llist(&tmp_llist);
1467                 }
1468         }
1469
1470         up_write(&cinode->lock_sem);
1471         kfree(buf);
1472         return rc;
1473 }
1474
1475 static int
1476 cifs_setlk(struct file *file, struct file_lock *flock, __u32 type,
1477            bool wait_flag, bool posix_lck, int lock, int unlock,
1478            unsigned int xid)
1479 {
1480         int rc = 0;
1481         __u64 length = 1 + flock->fl_end - flock->fl_start;
1482         struct cifsFileInfo *cfile = (struct cifsFileInfo *)file->private_data;
1483         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1484         struct TCP_Server_Info *server = tcon->ses->server;
1485         struct inode *inode = cfile->dentry->d_inode;
1486
1487         if (posix_lck) {
1488                 int posix_lock_type;
1489
1490                 rc = cifs_posix_lock_set(file, flock);
1491                 if (!rc || rc < 0)
1492                         return rc;
1493
1494                 if (type & server->vals->shared_lock_type)
1495                         posix_lock_type = CIFS_RDLCK;
1496                 else
1497                         posix_lock_type = CIFS_WRLCK;
1498
1499                 if (unlock == 1)
1500                         posix_lock_type = CIFS_UNLCK;
1501
1502                 rc = CIFSSMBPosixLock(xid, tcon, cfile->fid.netfid,
1503                                       current->tgid, flock->fl_start, length,
1504                                       NULL, posix_lock_type, wait_flag);
1505                 goto out;
1506         }
1507
1508         if (lock) {
1509                 struct cifsLockInfo *lock;
1510
1511                 lock = cifs_lock_init(flock->fl_start, length, type);
1512                 if (!lock)
1513                         return -ENOMEM;
1514
1515                 rc = cifs_lock_add_if(cfile, lock, wait_flag);
1516                 if (rc < 0) {
1517                         kfree(lock);
1518                         return rc;
1519                 }
1520                 if (!rc)
1521                         goto out;
1522
1523                 /*
1524                  * Windows 7 server can delay breaking lease from read to None
1525                  * if we set a byte-range lock on a file - break it explicitly
1526                  * before sending the lock to the server to be sure the next
1527                  * read won't conflict with non-overlapted locks due to
1528                  * pagereading.
1529                  */
1530                 if (!CIFS_CACHE_WRITE(CIFS_I(inode)) &&
1531                                         CIFS_CACHE_READ(CIFS_I(inode))) {
1532                         cifs_zap_mapping(inode);
1533                         cifs_dbg(FYI, "Set no oplock for inode=%p due to mand locks\n",
1534                                  inode);
1535                         CIFS_I(inode)->oplock = 0;
1536                 }
1537
1538                 rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length,
1539                                             type, 1, 0, wait_flag);
1540                 if (rc) {
1541                         kfree(lock);
1542                         return rc;
1543                 }
1544
1545                 cifs_lock_add(cfile, lock);
1546         } else if (unlock)
1547                 rc = server->ops->mand_unlock_range(cfile, flock, xid);
1548
1549 out:
1550         if (flock->fl_flags & FL_POSIX)
1551                 posix_lock_file_wait(file, flock);
1552         return rc;
1553 }
1554
1555 int cifs_lock(struct file *file, int cmd, struct file_lock *flock)
1556 {
1557         int rc, xid;
1558         int lock = 0, unlock = 0;
1559         bool wait_flag = false;
1560         bool posix_lck = false;
1561         struct cifs_sb_info *cifs_sb;
1562         struct cifs_tcon *tcon;
1563         struct cifsInodeInfo *cinode;
1564         struct cifsFileInfo *cfile;
1565         __u16 netfid;
1566         __u32 type;
1567
1568         rc = -EACCES;
1569         xid = get_xid();
1570
1571         cifs_dbg(FYI, "Lock parm: 0x%x flockflags: 0x%x flocktype: 0x%x start: %lld end: %lld\n",
1572                  cmd, flock->fl_flags, flock->fl_type,
1573                  flock->fl_start, flock->fl_end);
1574
1575         cfile = (struct cifsFileInfo *)file->private_data;
1576         tcon = tlink_tcon(cfile->tlink);
1577
1578         cifs_read_flock(flock, &type, &lock, &unlock, &wait_flag,
1579                         tcon->ses->server);
1580
1581         cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
1582         netfid = cfile->fid.netfid;
1583         cinode = CIFS_I(file_inode(file));
1584
1585         if (cap_unix(tcon->ses) &&
1586             (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
1587             ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
1588                 posix_lck = true;
1589         /*
1590          * BB add code here to normalize offset and length to account for
1591          * negative length which we can not accept over the wire.
1592          */
1593         if (IS_GETLK(cmd)) {
1594                 rc = cifs_getlk(file, flock, type, wait_flag, posix_lck, xid);
1595                 free_xid(xid);
1596                 return rc;
1597         }
1598
1599         if (!lock && !unlock) {
1600                 /*
1601                  * if no lock or unlock then nothing to do since we do not
1602                  * know what it is
1603                  */
1604                 free_xid(xid);
1605                 return -EOPNOTSUPP;
1606         }
1607
1608         rc = cifs_setlk(file, flock, type, wait_flag, posix_lck, lock, unlock,
1609                         xid);
1610         free_xid(xid);
1611         return rc;
1612 }
1613
1614 /*
1615  * update the file size (if needed) after a write. Should be called with
1616  * the inode->i_lock held
1617  */
1618 void
1619 cifs_update_eof(struct cifsInodeInfo *cifsi, loff_t offset,
1620                       unsigned int bytes_written)
1621 {
1622         loff_t end_of_write = offset + bytes_written;
1623
1624         if (end_of_write > cifsi->server_eof)
1625                 cifsi->server_eof = end_of_write;
1626 }
1627
1628 static ssize_t
1629 cifs_write(struct cifsFileInfo *open_file, __u32 pid, const char *write_data,
1630            size_t write_size, loff_t *offset)
1631 {
1632         int rc = 0;
1633         unsigned int bytes_written = 0;
1634         unsigned int total_written;
1635         struct cifs_sb_info *cifs_sb;
1636         struct cifs_tcon *tcon;
1637         struct TCP_Server_Info *server;
1638         unsigned int xid;
1639         struct dentry *dentry = open_file->dentry;
1640         struct cifsInodeInfo *cifsi = CIFS_I(dentry->d_inode);
1641         struct cifs_io_parms io_parms;
1642
1643         cifs_sb = CIFS_SB(dentry->d_sb);
1644
1645         cifs_dbg(FYI, "write %zd bytes to offset %lld of %s\n",
1646                  write_size, *offset, dentry->d_name.name);
1647
1648         tcon = tlink_tcon(open_file->tlink);
1649         server = tcon->ses->server;
1650
1651         if (!server->ops->sync_write)
1652                 return -ENOSYS;
1653
1654         xid = get_xid();
1655
1656         for (total_written = 0; write_size > total_written;
1657              total_written += bytes_written) {
1658                 rc = -EAGAIN;
1659                 while (rc == -EAGAIN) {
1660                         struct kvec iov[2];
1661                         unsigned int len;
1662
1663                         if (open_file->invalidHandle) {
1664                                 /* we could deadlock if we called
1665                                    filemap_fdatawait from here so tell
1666                                    reopen_file not to flush data to
1667                                    server now */
1668                                 rc = cifs_reopen_file(open_file, false);
1669                                 if (rc != 0)
1670                                         break;
1671                         }
1672
1673                         len = min((size_t)cifs_sb->wsize,
1674                                   write_size - total_written);
1675                         /* iov[0] is reserved for smb header */
1676                         iov[1].iov_base = (char *)write_data + total_written;
1677                         iov[1].iov_len = len;
1678                         io_parms.pid = pid;
1679                         io_parms.tcon = tcon;
1680                         io_parms.offset = *offset;
1681                         io_parms.length = len;
1682                         rc = server->ops->sync_write(xid, open_file, &io_parms,
1683                                                      &bytes_written, iov, 1);
1684                 }
1685                 if (rc || (bytes_written == 0)) {
1686                         if (total_written)
1687                                 break;
1688                         else {
1689                                 free_xid(xid);
1690                                 return rc;
1691                         }
1692                 } else {
1693                         spin_lock(&dentry->d_inode->i_lock);
1694                         cifs_update_eof(cifsi, *offset, bytes_written);
1695                         spin_unlock(&dentry->d_inode->i_lock);
1696                         *offset += bytes_written;
1697                 }
1698         }
1699
1700         cifs_stats_bytes_written(tcon, total_written);
1701
1702         if (total_written > 0) {
1703                 spin_lock(&dentry->d_inode->i_lock);
1704                 if (*offset > dentry->d_inode->i_size)
1705                         i_size_write(dentry->d_inode, *offset);
1706                 spin_unlock(&dentry->d_inode->i_lock);
1707         }
1708         mark_inode_dirty_sync(dentry->d_inode);
1709         free_xid(xid);
1710         return total_written;
1711 }
1712
1713 struct cifsFileInfo *find_readable_file(struct cifsInodeInfo *cifs_inode,
1714                                         bool fsuid_only)
1715 {
1716         struct cifsFileInfo *open_file = NULL;
1717         struct cifs_sb_info *cifs_sb = CIFS_SB(cifs_inode->vfs_inode.i_sb);
1718
1719         /* only filter by fsuid on multiuser mounts */
1720         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
1721                 fsuid_only = false;
1722
1723         spin_lock(&cifs_file_list_lock);
1724         /* we could simply get the first_list_entry since write-only entries
1725            are always at the end of the list but since the first entry might
1726            have a close pending, we go through the whole list */
1727         list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
1728                 if (fsuid_only && !uid_eq(open_file->uid, current_fsuid()))
1729                         continue;
1730                 if (OPEN_FMODE(open_file->f_flags) & FMODE_READ) {
1731                         if (!open_file->invalidHandle) {
1732                                 /* found a good file */
1733                                 /* lock it so it will not be closed on us */
1734                                 cifsFileInfo_get_locked(open_file);
1735                                 spin_unlock(&cifs_file_list_lock);
1736                                 return open_file;
1737                         } /* else might as well continue, and look for
1738                              another, or simply have the caller reopen it
1739                              again rather than trying to fix this handle */
1740                 } else /* write only file */
1741                         break; /* write only files are last so must be done */
1742         }
1743         spin_unlock(&cifs_file_list_lock);
1744         return NULL;
1745 }
1746
1747 struct cifsFileInfo *find_writable_file(struct cifsInodeInfo *cifs_inode,
1748                                         bool fsuid_only)
1749 {
1750         struct cifsFileInfo *open_file, *inv_file = NULL;
1751         struct cifs_sb_info *cifs_sb;
1752         bool any_available = false;
1753         int rc;
1754         unsigned int refind = 0;
1755
1756         /* Having a null inode here (because mapping->host was set to zero by
1757         the VFS or MM) should not happen but we had reports of on oops (due to
1758         it being zero) during stress testcases so we need to check for it */
1759
1760         if (cifs_inode == NULL) {
1761                 cifs_dbg(VFS, "Null inode passed to cifs_writeable_file\n");
1762                 dump_stack();
1763                 return NULL;
1764         }
1765
1766         cifs_sb = CIFS_SB(cifs_inode->vfs_inode.i_sb);
1767
1768         /* only filter by fsuid on multiuser mounts */
1769         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
1770                 fsuid_only = false;
1771
1772         spin_lock(&cifs_file_list_lock);
1773 refind_writable:
1774         if (refind > MAX_REOPEN_ATT) {
1775                 spin_unlock(&cifs_file_list_lock);
1776                 return NULL;
1777         }
1778         list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
1779                 if (!any_available && open_file->pid != current->tgid)
1780                         continue;
1781                 if (fsuid_only && !uid_eq(open_file->uid, current_fsuid()))
1782                         continue;
1783                 if (OPEN_FMODE(open_file->f_flags) & FMODE_WRITE) {
1784                         if (!open_file->invalidHandle) {
1785                                 /* found a good writable file */
1786                                 cifsFileInfo_get_locked(open_file);
1787                                 spin_unlock(&cifs_file_list_lock);
1788                                 return open_file;
1789                         } else {
1790                                 if (!inv_file)
1791                                         inv_file = open_file;
1792                         }
1793                 }
1794         }
1795         /* couldn't find useable FH with same pid, try any available */
1796         if (!any_available) {
1797                 any_available = true;
1798                 goto refind_writable;
1799         }
1800
1801         if (inv_file) {
1802                 any_available = false;
1803                 cifsFileInfo_get_locked(inv_file);
1804         }
1805
1806         spin_unlock(&cifs_file_list_lock);
1807
1808         if (inv_file) {
1809                 rc = cifs_reopen_file(inv_file, false);
1810                 if (!rc)
1811                         return inv_file;
1812                 else {
1813                         spin_lock(&cifs_file_list_lock);
1814                         list_move_tail(&inv_file->flist,
1815                                         &cifs_inode->openFileList);
1816                         spin_unlock(&cifs_file_list_lock);
1817                         cifsFileInfo_put(inv_file);
1818                         spin_lock(&cifs_file_list_lock);
1819                         ++refind;
1820                         goto refind_writable;
1821                 }
1822         }
1823
1824         return NULL;
1825 }
1826
1827 static int cifs_partialpagewrite(struct page *page, unsigned from, unsigned to)
1828 {
1829         struct address_space *mapping = page->mapping;
1830         loff_t offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
1831         char *write_data;
1832         int rc = -EFAULT;
1833         int bytes_written = 0;
1834         struct inode *inode;
1835         struct cifsFileInfo *open_file;
1836
1837         if (!mapping || !mapping->host)
1838                 return -EFAULT;
1839
1840         inode = page->mapping->host;
1841
1842         offset += (loff_t)from;
1843         write_data = kmap(page);
1844         write_data += from;
1845
1846         if ((to > PAGE_CACHE_SIZE) || (from > to)) {
1847                 kunmap(page);
1848                 return -EIO;
1849         }
1850
1851         /* racing with truncate? */
1852         if (offset > mapping->host->i_size) {
1853                 kunmap(page);
1854                 return 0; /* don't care */
1855         }
1856
1857         /* check to make sure that we are not extending the file */
1858         if (mapping->host->i_size - offset < (loff_t)to)
1859                 to = (unsigned)(mapping->host->i_size - offset);
1860
1861         open_file = find_writable_file(CIFS_I(mapping->host), false);
1862         if (open_file) {
1863                 bytes_written = cifs_write(open_file, open_file->pid,
1864                                            write_data, to - from, &offset);
1865                 cifsFileInfo_put(open_file);
1866                 /* Does mm or vfs already set times? */
1867                 inode->i_atime = inode->i_mtime = current_fs_time(inode->i_sb);
1868                 if ((bytes_written > 0) && (offset))
1869                         rc = 0;
1870                 else if (bytes_written < 0)
1871                         rc = bytes_written;
1872         } else {
1873                 cifs_dbg(FYI, "No writeable filehandles for inode\n");
1874                 rc = -EIO;
1875         }
1876
1877         kunmap(page);
1878         return rc;
1879 }
1880
1881 static struct cifs_writedata *
1882 wdata_alloc_and_fillpages(pgoff_t tofind, struct address_space *mapping,
1883                           pgoff_t end, pgoff_t *index,
1884                           unsigned int *found_pages)
1885 {
1886         unsigned int nr_pages;
1887         struct page **pages;
1888         struct cifs_writedata *wdata;
1889
1890         wdata = cifs_writedata_alloc((unsigned int)tofind,
1891                                      cifs_writev_complete);
1892         if (!wdata)
1893                 return NULL;
1894
1895         /*
1896          * find_get_pages_tag seems to return a max of 256 on each
1897          * iteration, so we must call it several times in order to
1898          * fill the array or the wsize is effectively limited to
1899          * 256 * PAGE_CACHE_SIZE.
1900          */
1901         *found_pages = 0;
1902         pages = wdata->pages;
1903         do {
1904                 nr_pages = find_get_pages_tag(mapping, index,
1905                                               PAGECACHE_TAG_DIRTY, tofind,
1906                                               pages);
1907                 *found_pages += nr_pages;
1908                 tofind -= nr_pages;
1909                 pages += nr_pages;
1910         } while (nr_pages && tofind && *index <= end);
1911
1912         return wdata;
1913 }
1914
1915 static unsigned int
1916 wdata_prepare_pages(struct cifs_writedata *wdata, unsigned int found_pages,
1917                     struct address_space *mapping,
1918                     struct writeback_control *wbc,
1919                     pgoff_t end, pgoff_t *index, pgoff_t *next, bool *done)
1920 {
1921         unsigned int nr_pages = 0, i;
1922         struct page *page;
1923
1924         for (i = 0; i < found_pages; i++) {
1925                 page = wdata->pages[i];
1926                 /*
1927                  * At this point we hold neither mapping->tree_lock nor
1928                  * lock on the page itself: the page may be truncated or
1929                  * invalidated (changing page->mapping to NULL), or even
1930                  * swizzled back from swapper_space to tmpfs file
1931                  * mapping
1932                  */
1933
1934                 if (nr_pages == 0)
1935                         lock_page(page);
1936                 else if (!trylock_page(page))
1937                         break;
1938
1939                 if (unlikely(page->mapping != mapping)) {
1940                         unlock_page(page);
1941                         break;
1942                 }
1943
1944                 if (!wbc->range_cyclic && page->index > end) {
1945                         *done = true;
1946                         unlock_page(page);
1947                         break;
1948                 }
1949
1950                 if (*next && (page->index != *next)) {
1951                         /* Not next consecutive page */
1952                         unlock_page(page);
1953                         break;
1954                 }
1955
1956                 if (wbc->sync_mode != WB_SYNC_NONE)
1957                         wait_on_page_writeback(page);
1958
1959                 if (PageWriteback(page) ||
1960                                 !clear_page_dirty_for_io(page)) {
1961                         unlock_page(page);
1962                         break;
1963                 }
1964
1965                 /*
1966                  * This actually clears the dirty bit in the radix tree.
1967                  * See cifs_writepage() for more commentary.
1968                  */
1969                 set_page_writeback(page);
1970                 if (page_offset(page) >= i_size_read(mapping->host)) {
1971                         *done = true;
1972                         unlock_page(page);
1973                         end_page_writeback(page);
1974                         break;
1975                 }
1976
1977                 wdata->pages[i] = page;
1978                 *next = page->index + 1;
1979                 ++nr_pages;
1980         }
1981
1982         /* reset index to refind any pages skipped */
1983         if (nr_pages == 0)
1984                 *index = wdata->pages[0]->index + 1;
1985
1986         /* put any pages we aren't going to use */
1987         for (i = nr_pages; i < found_pages; i++) {
1988                 page_cache_release(wdata->pages[i]);
1989                 wdata->pages[i] = NULL;
1990         }
1991
1992         return nr_pages;
1993 }
1994
1995 static int
1996 wdata_send_pages(struct cifs_writedata *wdata, unsigned int nr_pages,
1997                  struct address_space *mapping, struct writeback_control *wbc)
1998 {
1999         int rc = 0;
2000         struct TCP_Server_Info *server;
2001         unsigned int i;
2002
2003         wdata->sync_mode = wbc->sync_mode;
2004         wdata->nr_pages = nr_pages;
2005         wdata->offset = page_offset(wdata->pages[0]);
2006         wdata->pagesz = PAGE_CACHE_SIZE;
2007         wdata->tailsz = min(i_size_read(mapping->host) -
2008                         page_offset(wdata->pages[nr_pages - 1]),
2009                         (loff_t)PAGE_CACHE_SIZE);
2010         wdata->bytes = ((nr_pages - 1) * PAGE_CACHE_SIZE) + wdata->tailsz;
2011
2012         if (wdata->cfile != NULL)
2013                 cifsFileInfo_put(wdata->cfile);
2014         wdata->cfile = find_writable_file(CIFS_I(mapping->host), false);
2015         if (!wdata->cfile) {
2016                 cifs_dbg(VFS, "No writable handles for inode\n");
2017                 rc = -EBADF;
2018         } else {
2019                 wdata->pid = wdata->cfile->pid;
2020                 server = tlink_tcon(wdata->cfile->tlink)->ses->server;
2021                 rc = server->ops->async_writev(wdata, cifs_writedata_release);
2022         }
2023
2024         for (i = 0; i < nr_pages; ++i)
2025                 unlock_page(wdata->pages[i]);
2026
2027         return rc;
2028 }
2029
2030 static int cifs_writepages(struct address_space *mapping,
2031                            struct writeback_control *wbc)
2032 {
2033         struct cifs_sb_info *cifs_sb = CIFS_SB(mapping->host->i_sb);
2034         bool done = false, scanned = false, range_whole = false;
2035         pgoff_t end, index;
2036         struct cifs_writedata *wdata;
2037         int rc = 0;
2038
2039         /*
2040          * If wsize is smaller than the page cache size, default to writing
2041          * one page at a time via cifs_writepage
2042          */
2043         if (cifs_sb->wsize < PAGE_CACHE_SIZE)
2044                 return generic_writepages(mapping, wbc);
2045
2046         if (wbc->range_cyclic) {
2047                 index = mapping->writeback_index; /* Start from prev offset */
2048                 end = -1;
2049         } else {
2050                 index = wbc->range_start >> PAGE_CACHE_SHIFT;
2051                 end = wbc->range_end >> PAGE_CACHE_SHIFT;
2052                 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
2053                         range_whole = true;
2054                 scanned = true;
2055         }
2056 retry:
2057         while (!done && index <= end) {
2058                 unsigned int i, nr_pages, found_pages;
2059                 pgoff_t next = 0, tofind, saved_index = index;
2060
2061                 tofind = min((cifs_sb->wsize / PAGE_CACHE_SIZE) - 1,
2062                                 end - index) + 1;
2063
2064                 wdata = wdata_alloc_and_fillpages(tofind, mapping, end, &index,
2065                                                   &found_pages);
2066                 if (!wdata) {
2067                         rc = -ENOMEM;
2068                         break;
2069                 }
2070
2071                 if (found_pages == 0) {
2072                         kref_put(&wdata->refcount, cifs_writedata_release);
2073                         break;
2074                 }
2075
2076                 nr_pages = wdata_prepare_pages(wdata, found_pages, mapping, wbc,
2077                                                end, &index, &next, &done);
2078
2079                 /* nothing to write? */
2080                 if (nr_pages == 0) {
2081                         kref_put(&wdata->refcount, cifs_writedata_release);
2082                         continue;
2083                 }
2084
2085                 rc = wdata_send_pages(wdata, nr_pages, mapping, wbc);
2086
2087                 /* send failure -- clean up the mess */
2088                 if (rc != 0) {
2089                         for (i = 0; i < nr_pages; ++i) {
2090                                 if (rc == -EAGAIN)
2091                                         redirty_page_for_writepage(wbc,
2092                                                            wdata->pages[i]);
2093                                 else
2094                                         SetPageError(wdata->pages[i]);
2095                                 end_page_writeback(wdata->pages[i]);
2096                                 page_cache_release(wdata->pages[i]);
2097                         }
2098                         if (rc != -EAGAIN)
2099                                 mapping_set_error(mapping, rc);
2100                 }
2101                 kref_put(&wdata->refcount, cifs_writedata_release);
2102
2103                 if (wbc->sync_mode == WB_SYNC_ALL && rc == -EAGAIN) {
2104                         index = saved_index;
2105                         continue;
2106                 }
2107
2108                 wbc->nr_to_write -= nr_pages;
2109                 if (wbc->nr_to_write <= 0)
2110                         done = true;
2111
2112                 index = next;
2113         }
2114
2115         if (!scanned && !done) {
2116                 /*
2117                  * We hit the last page and there is more work to be done: wrap
2118                  * back to the start of the file
2119                  */
2120                 scanned = true;
2121                 index = 0;
2122                 goto retry;
2123         }
2124
2125         if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
2126                 mapping->writeback_index = index;
2127
2128         return rc;
2129 }
2130
2131 static int
2132 cifs_writepage_locked(struct page *page, struct writeback_control *wbc)
2133 {
2134         int rc;
2135         unsigned int xid;
2136
2137         xid = get_xid();
2138 /* BB add check for wbc flags */
2139         page_cache_get(page);
2140         if (!PageUptodate(page))
2141                 cifs_dbg(FYI, "ppw - page not up to date\n");
2142
2143         /*
2144          * Set the "writeback" flag, and clear "dirty" in the radix tree.
2145          *
2146          * A writepage() implementation always needs to do either this,
2147          * or re-dirty the page with "redirty_page_for_writepage()" in
2148          * the case of a failure.
2149          *
2150          * Just unlocking the page will cause the radix tree tag-bits
2151          * to fail to update with the state of the page correctly.
2152          */
2153         set_page_writeback(page);
2154 retry_write:
2155         rc = cifs_partialpagewrite(page, 0, PAGE_CACHE_SIZE);
2156         if (rc == -EAGAIN && wbc->sync_mode == WB_SYNC_ALL)
2157                 goto retry_write;
2158         else if (rc == -EAGAIN)
2159                 redirty_page_for_writepage(wbc, page);
2160         else if (rc != 0)
2161                 SetPageError(page);
2162         else
2163                 SetPageUptodate(page);
2164         end_page_writeback(page);
2165         page_cache_release(page);
2166         free_xid(xid);
2167         return rc;
2168 }
2169
2170 static int cifs_writepage(struct page *page, struct writeback_control *wbc)
2171 {
2172         int rc = cifs_writepage_locked(page, wbc);
2173         unlock_page(page);
2174         return rc;
2175 }
2176
2177 static int cifs_write_end(struct file *file, struct address_space *mapping,
2178                         loff_t pos, unsigned len, unsigned copied,
2179                         struct page *page, void *fsdata)
2180 {
2181         int rc;
2182         struct inode *inode = mapping->host;
2183         struct cifsFileInfo *cfile = file->private_data;
2184         struct cifs_sb_info *cifs_sb = CIFS_SB(cfile->dentry->d_sb);
2185         __u32 pid;
2186
2187         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
2188                 pid = cfile->pid;
2189         else
2190                 pid = current->tgid;
2191
2192         cifs_dbg(FYI, "write_end for page %p from pos %lld with %d bytes\n",
2193                  page, pos, copied);
2194
2195         if (PageChecked(page)) {
2196                 if (copied == len)
2197                         SetPageUptodate(page);
2198                 ClearPageChecked(page);
2199         } else if (!PageUptodate(page) && copied == PAGE_CACHE_SIZE)
2200                 SetPageUptodate(page);
2201
2202         if (!PageUptodate(page)) {
2203                 char *page_data;
2204                 unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
2205                 unsigned int xid;
2206
2207                 xid = get_xid();
2208                 /* this is probably better than directly calling
2209                    partialpage_write since in this function the file handle is
2210                    known which we might as well leverage */
2211                 /* BB check if anything else missing out of ppw
2212                    such as updating last write time */
2213                 page_data = kmap(page);
2214                 rc = cifs_write(cfile, pid, page_data + offset, copied, &pos);
2215                 /* if (rc < 0) should we set writebehind rc? */
2216                 kunmap(page);
2217
2218                 free_xid(xid);
2219         } else {
2220                 rc = copied;
2221                 pos += copied;
2222                 set_page_dirty(page);
2223         }
2224
2225         if (rc > 0) {
2226                 spin_lock(&inode->i_lock);
2227                 if (pos > inode->i_size)
2228                         i_size_write(inode, pos);
2229                 spin_unlock(&inode->i_lock);
2230         }
2231
2232         unlock_page(page);
2233         page_cache_release(page);
2234
2235         return rc;
2236 }
2237
2238 int cifs_strict_fsync(struct file *file, loff_t start, loff_t end,
2239                       int datasync)
2240 {
2241         unsigned int xid;
2242         int rc = 0;
2243         struct cifs_tcon *tcon;
2244         struct TCP_Server_Info *server;
2245         struct cifsFileInfo *smbfile = file->private_data;
2246         struct inode *inode = file_inode(file);
2247         struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
2248
2249         rc = filemap_write_and_wait_range(inode->i_mapping, start, end);
2250         if (rc)
2251                 return rc;
2252         mutex_lock(&inode->i_mutex);
2253
2254         xid = get_xid();
2255
2256         cifs_dbg(FYI, "Sync file - name: %s datasync: 0x%x\n",
2257                  file->f_path.dentry->d_name.name, datasync);
2258
2259         if (!CIFS_CACHE_READ(CIFS_I(inode))) {
2260                 rc = cifs_zap_mapping(inode);
2261                 if (rc) {
2262                         cifs_dbg(FYI, "rc: %d during invalidate phase\n", rc);
2263                         rc = 0; /* don't care about it in fsync */
2264                 }
2265         }
2266
2267         tcon = tlink_tcon(smbfile->tlink);
2268         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC)) {
2269                 server = tcon->ses->server;
2270                 if (server->ops->flush)
2271                         rc = server->ops->flush(xid, tcon, &smbfile->fid);
2272                 else
2273                         rc = -ENOSYS;
2274         }
2275
2276         free_xid(xid);
2277         mutex_unlock(&inode->i_mutex);
2278         return rc;
2279 }
2280
2281 int cifs_fsync(struct file *file, loff_t start, loff_t end, int datasync)
2282 {
2283         unsigned int xid;
2284         int rc = 0;
2285         struct cifs_tcon *tcon;
2286         struct TCP_Server_Info *server;
2287         struct cifsFileInfo *smbfile = file->private_data;
2288         struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
2289         struct inode *inode = file->f_mapping->host;
2290
2291         rc = filemap_write_and_wait_range(inode->i_mapping, start, end);
2292         if (rc)
2293                 return rc;
2294         mutex_lock(&inode->i_mutex);
2295
2296         xid = get_xid();
2297
2298         cifs_dbg(FYI, "Sync file - name: %s datasync: 0x%x\n",
2299                  file->f_path.dentry->d_name.name, datasync);
2300
2301         tcon = tlink_tcon(smbfile->tlink);
2302         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC)) {
2303                 server = tcon->ses->server;
2304                 if (server->ops->flush)
2305                         rc = server->ops->flush(xid, tcon, &smbfile->fid);
2306                 else
2307                         rc = -ENOSYS;
2308         }
2309
2310         free_xid(xid);
2311         mutex_unlock(&inode->i_mutex);
2312         return rc;
2313 }
2314
2315 /*
2316  * As file closes, flush all cached write data for this inode checking
2317  * for write behind errors.
2318  */
2319 int cifs_flush(struct file *file, fl_owner_t id)
2320 {
2321         struct inode *inode = file_inode(file);
2322         int rc = 0;
2323
2324         if (file->f_mode & FMODE_WRITE)
2325                 rc = filemap_write_and_wait(inode->i_mapping);
2326
2327         cifs_dbg(FYI, "Flush inode %p file %p rc %d\n", inode, file, rc);
2328
2329         return rc;
2330 }
2331
2332 static int
2333 cifs_write_allocate_pages(struct page **pages, unsigned long num_pages)
2334 {
2335         int rc = 0;
2336         unsigned long i;
2337
2338         for (i = 0; i < num_pages; i++) {
2339                 pages[i] = alloc_page(GFP_KERNEL|__GFP_HIGHMEM);
2340                 if (!pages[i]) {
2341                         /*
2342                          * save number of pages we have already allocated and
2343                          * return with ENOMEM error
2344                          */
2345                         num_pages = i;
2346                         rc = -ENOMEM;
2347                         break;
2348                 }
2349         }
2350
2351         if (rc) {
2352                 for (i = 0; i < num_pages; i++)
2353                         put_page(pages[i]);
2354         }
2355         return rc;
2356 }
2357
2358 static inline
2359 size_t get_numpages(const size_t wsize, const size_t len, size_t *cur_len)
2360 {
2361         size_t num_pages;
2362         size_t clen;
2363
2364         clen = min_t(const size_t, len, wsize);
2365         num_pages = DIV_ROUND_UP(clen, PAGE_SIZE);
2366
2367         if (cur_len)
2368                 *cur_len = clen;
2369
2370         return num_pages;
2371 }
2372
2373 static void
2374 cifs_uncached_writedata_release(struct kref *refcount)
2375 {
2376         int i;
2377         struct cifs_writedata *wdata = container_of(refcount,
2378                                         struct cifs_writedata, refcount);
2379
2380         for (i = 0; i < wdata->nr_pages; i++)
2381                 put_page(wdata->pages[i]);
2382         cifs_writedata_release(refcount);
2383 }
2384
2385 static void
2386 cifs_uncached_writev_complete(struct work_struct *work)
2387 {
2388         struct cifs_writedata *wdata = container_of(work,
2389                                         struct cifs_writedata, work);
2390         struct inode *inode = wdata->cfile->dentry->d_inode;
2391         struct cifsInodeInfo *cifsi = CIFS_I(inode);
2392
2393         spin_lock(&inode->i_lock);
2394         cifs_update_eof(cifsi, wdata->offset, wdata->bytes);
2395         if (cifsi->server_eof > inode->i_size)
2396                 i_size_write(inode, cifsi->server_eof);
2397         spin_unlock(&inode->i_lock);
2398
2399         complete(&wdata->done);
2400
2401         kref_put(&wdata->refcount, cifs_uncached_writedata_release);
2402 }
2403
2404 /* attempt to send write to server, retry on any -EAGAIN errors */
2405 static int
2406 cifs_uncached_retry_writev(struct cifs_writedata *wdata)
2407 {
2408         int rc;
2409         struct TCP_Server_Info *server;
2410
2411         server = tlink_tcon(wdata->cfile->tlink)->ses->server;
2412
2413         do {
2414                 if (wdata->cfile->invalidHandle) {
2415                         rc = cifs_reopen_file(wdata->cfile, false);
2416                         if (rc != 0)
2417                                 continue;
2418                 }
2419                 rc = server->ops->async_writev(wdata,
2420                                                cifs_uncached_writedata_release);
2421         } while (rc == -EAGAIN);
2422
2423         return rc;
2424 }
2425
2426 static int
2427 wdata_fill_from_iovec(struct cifs_writedata *wdata, struct iov_iter *from,
2428                       size_t *len, unsigned long *num_pages)
2429 {
2430         size_t save_len, copied, bytes, cur_len = *len;
2431         unsigned long i, nr_pages = *num_pages;
2432
2433         save_len = cur_len;
2434         for (i = 0; i < nr_pages; i++) {
2435                 bytes = min_t(const size_t, cur_len, PAGE_SIZE);
2436                 copied = copy_page_from_iter(wdata->pages[i], 0, bytes, from);
2437                 cur_len -= copied;
2438                 /*
2439                  * If we didn't copy as much as we expected, then that
2440                  * may mean we trod into an unmapped area. Stop copying
2441                  * at that point. On the next pass through the big
2442                  * loop, we'll likely end up getting a zero-length
2443                  * write and bailing out of it.
2444                  */
2445                 if (copied < bytes)
2446                         break;
2447         }
2448         cur_len = save_len - cur_len;
2449         *len = cur_len;
2450
2451         /*
2452          * If we have no data to send, then that probably means that
2453          * the copy above failed altogether. That's most likely because
2454          * the address in the iovec was bogus. Return -EFAULT and let
2455          * the caller free anything we allocated and bail out.
2456          */
2457         if (!cur_len)
2458                 return -EFAULT;
2459
2460         /*
2461          * i + 1 now represents the number of pages we actually used in
2462          * the copy phase above.
2463          */
2464         *num_pages = i + 1;
2465         return 0;
2466 }
2467
2468 static ssize_t
2469 cifs_iovec_write(struct file *file, struct iov_iter *from, loff_t *poffset)
2470 {
2471         unsigned long nr_pages, num_pages, i;
2472         size_t len, cur_len;
2473         ssize_t total_written = 0;
2474         loff_t offset;
2475         struct cifsFileInfo *open_file;
2476         struct cifs_tcon *tcon;
2477         struct cifs_sb_info *cifs_sb;
2478         struct cifs_writedata *wdata, *tmp;
2479         struct list_head wdata_list;
2480         int rc;
2481         pid_t pid;
2482
2483         len = iov_iter_count(from);
2484         rc = generic_write_checks(file, poffset, &len, 0);
2485         if (rc)
2486                 return rc;
2487
2488         if (!len)
2489                 return 0;
2490
2491         iov_iter_truncate(from, len);
2492
2493         INIT_LIST_HEAD(&wdata_list);
2494         cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
2495         open_file = file->private_data;
2496         tcon = tlink_tcon(open_file->tlink);
2497
2498         if (!tcon->ses->server->ops->async_writev)
2499                 return -ENOSYS;
2500
2501         offset = *poffset;
2502
2503         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
2504                 pid = open_file->pid;
2505         else
2506                 pid = current->tgid;
2507
2508         do {
2509                 nr_pages = get_numpages(cifs_sb->wsize, len, &cur_len);
2510                 wdata = cifs_writedata_alloc(nr_pages,
2511                                              cifs_uncached_writev_complete);
2512                 if (!wdata) {
2513                         rc = -ENOMEM;
2514                         break;
2515                 }
2516
2517                 rc = cifs_write_allocate_pages(wdata->pages, nr_pages);
2518                 if (rc) {
2519                         kfree(wdata);
2520                         break;
2521                 }
2522
2523                 num_pages = nr_pages;
2524                 rc = wdata_fill_from_iovec(wdata, from, &cur_len, &num_pages);
2525                 if (rc) {
2526                         for (i = 0; i < nr_pages; i++)
2527                                 put_page(wdata->pages[i]);
2528                         kfree(wdata);
2529                         break;
2530                 }
2531
2532                 /*
2533                  * Bring nr_pages down to the number of pages we actually used,
2534                  * and free any pages that we didn't use.
2535                  */
2536                 for ( ; nr_pages > num_pages; nr_pages--)
2537                         put_page(wdata->pages[nr_pages - 1]);
2538
2539                 wdata->sync_mode = WB_SYNC_ALL;
2540                 wdata->nr_pages = nr_pages;
2541                 wdata->offset = (__u64)offset;
2542                 wdata->cfile = cifsFileInfo_get(open_file);
2543                 wdata->pid = pid;
2544                 wdata->bytes = cur_len;
2545                 wdata->pagesz = PAGE_SIZE;
2546                 wdata->tailsz = cur_len - ((nr_pages - 1) * PAGE_SIZE);
2547                 rc = cifs_uncached_retry_writev(wdata);
2548                 if (rc) {
2549                         kref_put(&wdata->refcount,
2550                                  cifs_uncached_writedata_release);
2551                         break;
2552                 }
2553
2554                 list_add_tail(&wdata->list, &wdata_list);
2555                 offset += cur_len;
2556                 len -= cur_len;
2557         } while (len > 0);
2558
2559         /*
2560          * If at least one write was successfully sent, then discard any rc
2561          * value from the later writes. If the other write succeeds, then
2562          * we'll end up returning whatever was written. If it fails, then
2563          * we'll get a new rc value from that.
2564          */
2565         if (!list_empty(&wdata_list))
2566                 rc = 0;
2567
2568         /*
2569          * Wait for and collect replies for any successful sends in order of
2570          * increasing offset. Once an error is hit or we get a fatal signal
2571          * while waiting, then return without waiting for any more replies.
2572          */
2573 restart_loop:
2574         list_for_each_entry_safe(wdata, tmp, &wdata_list, list) {
2575                 if (!rc) {
2576                         /* FIXME: freezable too? */
2577                         rc = wait_for_completion_killable(&wdata->done);
2578                         if (rc)
2579                                 rc = -EINTR;
2580                         else if (wdata->result)
2581                                 rc = wdata->result;
2582                         else
2583                                 total_written += wdata->bytes;
2584
2585                         /* resend call if it's a retryable error */
2586                         if (rc == -EAGAIN) {
2587                                 rc = cifs_uncached_retry_writev(wdata);
2588                                 goto restart_loop;
2589                         }
2590                 }
2591                 list_del_init(&wdata->list);
2592                 kref_put(&wdata->refcount, cifs_uncached_writedata_release);
2593         }
2594
2595         if (total_written > 0)
2596                 *poffset += total_written;
2597
2598         cifs_stats_bytes_written(tcon, total_written);
2599         return total_written ? total_written : (ssize_t)rc;
2600 }
2601
2602 ssize_t cifs_user_writev(struct kiocb *iocb, struct iov_iter *from)
2603 {
2604         ssize_t written;
2605         struct inode *inode;
2606         loff_t pos = iocb->ki_pos;
2607
2608         inode = file_inode(iocb->ki_filp);
2609
2610         /*
2611          * BB - optimize the way when signing is disabled. We can drop this
2612          * extra memory-to-memory copying and use iovec buffers for constructing
2613          * write request.
2614          */
2615
2616         written = cifs_iovec_write(iocb->ki_filp, from, &pos);
2617         if (written > 0) {
2618                 set_bit(CIFS_INO_INVALID_MAPPING, &CIFS_I(inode)->flags);
2619                 iocb->ki_pos = pos;
2620         }
2621
2622         return written;
2623 }
2624
2625 static ssize_t
2626 cifs_writev(struct kiocb *iocb, struct iov_iter *from)
2627 {
2628         struct file *file = iocb->ki_filp;
2629         struct cifsFileInfo *cfile = (struct cifsFileInfo *)file->private_data;
2630         struct inode *inode = file->f_mapping->host;
2631         struct cifsInodeInfo *cinode = CIFS_I(inode);
2632         struct TCP_Server_Info *server = tlink_tcon(cfile->tlink)->ses->server;
2633         ssize_t rc = -EACCES;
2634         loff_t lock_pos = iocb->ki_pos;
2635
2636         /*
2637          * We need to hold the sem to be sure nobody modifies lock list
2638          * with a brlock that prevents writing.
2639          */
2640         down_read(&cinode->lock_sem);
2641         mutex_lock(&inode->i_mutex);
2642         if (file->f_flags & O_APPEND)
2643                 lock_pos = i_size_read(inode);
2644         if (!cifs_find_lock_conflict(cfile, lock_pos, iov_iter_count(from),
2645                                      server->vals->exclusive_lock_type, NULL,
2646                                      CIFS_WRITE_OP)) {
2647                 rc = __generic_file_write_iter(iocb, from);
2648                 mutex_unlock(&inode->i_mutex);
2649
2650                 if (rc > 0) {
2651                         ssize_t err;
2652
2653                         err = generic_write_sync(file, iocb->ki_pos - rc, rc);
2654                         if (err < 0)
2655                                 rc = err;
2656                 }
2657         } else {
2658                 mutex_unlock(&inode->i_mutex);
2659         }
2660         up_read(&cinode->lock_sem);
2661         return rc;
2662 }
2663
2664 ssize_t
2665 cifs_strict_writev(struct kiocb *iocb, struct iov_iter *from)
2666 {
2667         struct inode *inode = file_inode(iocb->ki_filp);
2668         struct cifsInodeInfo *cinode = CIFS_I(inode);
2669         struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
2670         struct cifsFileInfo *cfile = (struct cifsFileInfo *)
2671                                                 iocb->ki_filp->private_data;
2672         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
2673         ssize_t written;
2674
2675         written = cifs_get_writer(cinode);
2676         if (written)
2677                 return written;
2678
2679         if (CIFS_CACHE_WRITE(cinode)) {
2680                 if (cap_unix(tcon->ses) &&
2681                 (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability))
2682                   && ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0)) {
2683                         written = generic_file_write_iter(iocb, from);
2684                         goto out;
2685                 }
2686                 written = cifs_writev(iocb, from);
2687                 goto out;
2688         }
2689         /*
2690          * For non-oplocked files in strict cache mode we need to write the data
2691          * to the server exactly from the pos to pos+len-1 rather than flush all
2692          * affected pages because it may cause a error with mandatory locks on
2693          * these pages but not on the region from pos to ppos+len-1.
2694          */
2695         written = cifs_user_writev(iocb, from);
2696         if (written > 0 && CIFS_CACHE_READ(cinode)) {
2697                 /*
2698                  * Windows 7 server can delay breaking level2 oplock if a write
2699                  * request comes - break it on the client to prevent reading
2700                  * an old data.
2701                  */
2702                 cifs_zap_mapping(inode);
2703                 cifs_dbg(FYI, "Set no oplock for inode=%p after a write operation\n",
2704                          inode);
2705                 cinode->oplock = 0;
2706         }
2707 out:
2708         cifs_put_writer(cinode);
2709         return written;
2710 }
2711
2712 static struct cifs_readdata *
2713 cifs_readdata_alloc(unsigned int nr_pages, work_func_t complete)
2714 {
2715         struct cifs_readdata *rdata;
2716
2717         rdata = kzalloc(sizeof(*rdata) + (sizeof(struct page *) * nr_pages),
2718                         GFP_KERNEL);
2719         if (rdata != NULL) {
2720                 kref_init(&rdata->refcount);
2721                 INIT_LIST_HEAD(&rdata->list);
2722                 init_completion(&rdata->done);
2723                 INIT_WORK(&rdata->work, complete);
2724         }
2725
2726         return rdata;
2727 }
2728
2729 void
2730 cifs_readdata_release(struct kref *refcount)
2731 {
2732         struct cifs_readdata *rdata = container_of(refcount,
2733                                         struct cifs_readdata, refcount);
2734
2735         if (rdata->cfile)
2736                 cifsFileInfo_put(rdata->cfile);
2737
2738         kfree(rdata);
2739 }
2740
2741 static int
2742 cifs_read_allocate_pages(struct cifs_readdata *rdata, unsigned int nr_pages)
2743 {
2744         int rc = 0;
2745         struct page *page;
2746         unsigned int i;
2747
2748         for (i = 0; i < nr_pages; i++) {
2749                 page = alloc_page(GFP_KERNEL|__GFP_HIGHMEM);
2750                 if (!page) {
2751                         rc = -ENOMEM;
2752                         break;
2753                 }
2754                 rdata->pages[i] = page;
2755         }
2756
2757         if (rc) {
2758                 for (i = 0; i < nr_pages; i++) {
2759                         put_page(rdata->pages[i]);
2760                         rdata->pages[i] = NULL;
2761                 }
2762         }
2763         return rc;
2764 }
2765
2766 static void
2767 cifs_uncached_readdata_release(struct kref *refcount)
2768 {
2769         struct cifs_readdata *rdata = container_of(refcount,
2770                                         struct cifs_readdata, refcount);
2771         unsigned int i;
2772
2773         for (i = 0; i < rdata->nr_pages; i++) {
2774                 put_page(rdata->pages[i]);
2775                 rdata->pages[i] = NULL;
2776         }
2777         cifs_readdata_release(refcount);
2778 }
2779
2780 static int
2781 cifs_retry_async_readv(struct cifs_readdata *rdata)
2782 {
2783         int rc;
2784         struct TCP_Server_Info *server;
2785
2786         server = tlink_tcon(rdata->cfile->tlink)->ses->server;
2787
2788         do {
2789                 if (rdata->cfile->invalidHandle) {
2790                         rc = cifs_reopen_file(rdata->cfile, true);
2791                         if (rc != 0)
2792                                 continue;
2793                 }
2794                 rc = server->ops->async_readv(rdata);
2795         } while (rc == -EAGAIN);
2796
2797         return rc;
2798 }
2799
2800 /**
2801  * cifs_readdata_to_iov - copy data from pages in response to an iovec
2802  * @rdata:      the readdata response with list of pages holding data
2803  * @iter:       destination for our data
2804  *
2805  * This function copies data from a list of pages in a readdata response into
2806  * an array of iovecs. It will first calculate where the data should go
2807  * based on the info in the readdata and then copy the data into that spot.
2808  */
2809 static int
2810 cifs_readdata_to_iov(struct cifs_readdata *rdata, struct iov_iter *iter)
2811 {
2812         size_t remaining = rdata->bytes;
2813         unsigned int i;
2814
2815         for (i = 0; i < rdata->nr_pages; i++) {
2816                 struct page *page = rdata->pages[i];
2817                 size_t copy = min_t(size_t, remaining, PAGE_SIZE);
2818                 size_t written = copy_page_to_iter(page, 0, copy, iter);
2819                 remaining -= written;
2820                 if (written < copy && iov_iter_count(iter) > 0)
2821                         break;
2822         }
2823         return remaining ? -EFAULT : 0;
2824 }
2825
2826 static void
2827 cifs_uncached_readv_complete(struct work_struct *work)
2828 {
2829         struct cifs_readdata *rdata = container_of(work,
2830                                                 struct cifs_readdata, work);
2831
2832         complete(&rdata->done);
2833         kref_put(&rdata->refcount, cifs_uncached_readdata_release);
2834 }
2835
2836 static int
2837 cifs_uncached_read_into_pages(struct TCP_Server_Info *server,
2838                         struct cifs_readdata *rdata, unsigned int len)
2839 {
2840         int total_read = 0, result = 0;
2841         unsigned int i;
2842         unsigned int nr_pages = rdata->nr_pages;
2843         struct kvec iov;
2844
2845         rdata->tailsz = PAGE_SIZE;
2846         for (i = 0; i < nr_pages; i++) {
2847                 struct page *page = rdata->pages[i];
2848
2849                 if (len >= PAGE_SIZE) {
2850                         /* enough data to fill the page */
2851                         iov.iov_base = kmap(page);
2852                         iov.iov_len = PAGE_SIZE;
2853                         cifs_dbg(FYI, "%u: iov_base=%p iov_len=%zu\n",
2854                                  i, iov.iov_base, iov.iov_len);
2855                         len -= PAGE_SIZE;
2856                 } else if (len > 0) {
2857                         /* enough for partial page, fill and zero the rest */
2858                         iov.iov_base = kmap(page);
2859                         iov.iov_len = len;
2860                         cifs_dbg(FYI, "%u: iov_base=%p iov_len=%zu\n",
2861                                  i, iov.iov_base, iov.iov_len);
2862                         memset(iov.iov_base + len, '\0', PAGE_SIZE - len);
2863                         rdata->tailsz = len;
2864                         len = 0;
2865                 } else {
2866                         /* no need to hold page hostage */
2867                         rdata->pages[i] = NULL;
2868                         rdata->nr_pages--;
2869                         put_page(page);
2870                         continue;
2871                 }
2872
2873                 result = cifs_readv_from_socket(server, &iov, 1, iov.iov_len);
2874                 kunmap(page);
2875                 if (result < 0)
2876                         break;
2877
2878                 total_read += result;
2879         }
2880
2881         return total_read > 0 && result != -EAGAIN ? total_read : result;
2882 }
2883
2884 ssize_t cifs_user_readv(struct kiocb *iocb, struct iov_iter *to)
2885 {
2886         struct file *file = iocb->ki_filp;
2887         ssize_t rc;
2888         size_t len, cur_len;
2889         ssize_t total_read = 0;
2890         loff_t offset = iocb->ki_pos;
2891         unsigned int npages;
2892         struct cifs_sb_info *cifs_sb;
2893         struct cifs_tcon *tcon;
2894         struct cifsFileInfo *open_file;
2895         struct cifs_readdata *rdata, *tmp;
2896         struct list_head rdata_list;
2897         pid_t pid;
2898
2899         len = iov_iter_count(to);
2900         if (!len)
2901                 return 0;
2902
2903         INIT_LIST_HEAD(&rdata_list);
2904         cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
2905         open_file = file->private_data;
2906         tcon = tlink_tcon(open_file->tlink);
2907
2908         if (!tcon->ses->server->ops->async_readv)
2909                 return -ENOSYS;
2910
2911         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
2912                 pid = open_file->pid;
2913         else
2914                 pid = current->tgid;
2915
2916         if ((file->f_flags & O_ACCMODE) == O_WRONLY)
2917                 cifs_dbg(FYI, "attempting read on write only file instance\n");
2918
2919         do {
2920                 cur_len = min_t(const size_t, len - total_read, cifs_sb->rsize);
2921                 npages = DIV_ROUND_UP(cur_len, PAGE_SIZE);
2922
2923                 /* allocate a readdata struct */
2924                 rdata = cifs_readdata_alloc(npages,
2925                                             cifs_uncached_readv_complete);
2926                 if (!rdata) {
2927                         rc = -ENOMEM;
2928                         break;
2929                 }
2930
2931                 rc = cifs_read_allocate_pages(rdata, npages);
2932                 if (rc)
2933                         goto error;
2934
2935                 rdata->cfile = cifsFileInfo_get(open_file);
2936                 rdata->nr_pages = npages;
2937                 rdata->offset = offset;
2938                 rdata->bytes = cur_len;
2939                 rdata->pid = pid;
2940                 rdata->pagesz = PAGE_SIZE;
2941                 rdata->read_into_pages = cifs_uncached_read_into_pages;
2942
2943                 rc = cifs_retry_async_readv(rdata);
2944 error:
2945                 if (rc) {
2946                         kref_put(&rdata->refcount,
2947                                  cifs_uncached_readdata_release);
2948                         break;
2949                 }
2950
2951                 list_add_tail(&rdata->list, &rdata_list);
2952                 offset += cur_len;
2953                 len -= cur_len;
2954         } while (len > 0);
2955
2956         /* if at least one read request send succeeded, then reset rc */
2957         if (!list_empty(&rdata_list))
2958                 rc = 0;
2959
2960         len = iov_iter_count(to);
2961         /* the loop below should proceed in the order of increasing offsets */
2962         list_for_each_entry_safe(rdata, tmp, &rdata_list, list) {
2963         again:
2964                 if (!rc) {
2965                         /* FIXME: freezable sleep too? */
2966                         rc = wait_for_completion_killable(&rdata->done);
2967                         if (rc)
2968                                 rc = -EINTR;
2969                         else if (rdata->result) {
2970                                 rc = rdata->result;
2971                                 /* resend call if it's a retryable error */
2972                                 if (rc == -EAGAIN) {
2973                                         rc = cifs_retry_async_readv(rdata);
2974                                         goto again;
2975                                 }
2976                         } else {
2977                                 rc = cifs_readdata_to_iov(rdata, to);
2978                         }
2979
2980                 }
2981                 list_del_init(&rdata->list);
2982                 kref_put(&rdata->refcount, cifs_uncached_readdata_release);
2983         }
2984
2985         total_read = len - iov_iter_count(to);
2986
2987         cifs_stats_bytes_read(tcon, total_read);
2988
2989         /* mask nodata case */
2990         if (rc == -ENODATA)
2991                 rc = 0;
2992
2993         if (total_read) {
2994                 iocb->ki_pos += total_read;
2995                 return total_read;
2996         }
2997         return rc;
2998 }
2999
3000 ssize_t
3001 cifs_strict_readv(struct kiocb *iocb, struct iov_iter *to)
3002 {
3003         struct inode *inode = file_inode(iocb->ki_filp);
3004         struct cifsInodeInfo *cinode = CIFS_I(inode);
3005         struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
3006         struct cifsFileInfo *cfile = (struct cifsFileInfo *)
3007                                                 iocb->ki_filp->private_data;
3008         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
3009         int rc = -EACCES;
3010
3011         /*
3012          * In strict cache mode we need to read from the server all the time
3013          * if we don't have level II oplock because the server can delay mtime
3014          * change - so we can't make a decision about inode invalidating.
3015          * And we can also fail with pagereading if there are mandatory locks
3016          * on pages affected by this read but not on the region from pos to
3017          * pos+len-1.
3018          */
3019         if (!CIFS_CACHE_READ(cinode))
3020                 return cifs_user_readv(iocb, to);
3021
3022         if (cap_unix(tcon->ses) &&
3023             (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
3024             ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
3025                 return generic_file_read_iter(iocb, to);
3026
3027         /*
3028          * We need to hold the sem to be sure nobody modifies lock list
3029          * with a brlock that prevents reading.
3030          */
3031         down_read(&cinode->lock_sem);
3032         if (!cifs_find_lock_conflict(cfile, iocb->ki_pos, iov_iter_count(to),
3033                                      tcon->ses->server->vals->shared_lock_type,
3034                                      NULL, CIFS_READ_OP))
3035                 rc = generic_file_read_iter(iocb, to);
3036         up_read(&cinode->lock_sem);
3037         return rc;
3038 }
3039
3040 static ssize_t
3041 cifs_read(struct file *file, char *read_data, size_t read_size, loff_t *offset)
3042 {
3043         int rc = -EACCES;
3044         unsigned int bytes_read = 0;
3045         unsigned int total_read;
3046         unsigned int current_read_size;
3047         unsigned int rsize;
3048         struct cifs_sb_info *cifs_sb;
3049         struct cifs_tcon *tcon;
3050         struct TCP_Server_Info *server;
3051         unsigned int xid;
3052         char *cur_offset;
3053         struct cifsFileInfo *open_file;
3054         struct cifs_io_parms io_parms;
3055         int buf_type = CIFS_NO_BUFFER;
3056         __u32 pid;
3057
3058         xid = get_xid();
3059         cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
3060
3061         /* FIXME: set up handlers for larger reads and/or convert to async */
3062         rsize = min_t(unsigned int, cifs_sb->rsize, CIFSMaxBufSize);
3063
3064         if (file->private_data == NULL) {
3065                 rc = -EBADF;
3066                 free_xid(xid);
3067                 return rc;
3068         }
3069         open_file = file->private_data;
3070         tcon = tlink_tcon(open_file->tlink);
3071         server = tcon->ses->server;
3072
3073         if (!server->ops->sync_read) {
3074                 free_xid(xid);
3075                 return -ENOSYS;
3076         }
3077
3078         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
3079                 pid = open_file->pid;
3080         else
3081                 pid = current->tgid;
3082
3083         if ((file->f_flags & O_ACCMODE) == O_WRONLY)
3084                 cifs_dbg(FYI, "attempting read on write only file instance\n");
3085
3086         for (total_read = 0, cur_offset = read_data; read_size > total_read;
3087              total_read += bytes_read, cur_offset += bytes_read) {
3088                 current_read_size = min_t(uint, read_size - total_read, rsize);
3089                 /*
3090                  * For windows me and 9x we do not want to request more than it
3091                  * negotiated since it will refuse the read then.
3092                  */
3093                 if ((tcon->ses) && !(tcon->ses->capabilities &
3094                                 tcon->ses->server->vals->cap_large_files)) {
3095                         current_read_size = min_t(uint, current_read_size,
3096                                         CIFSMaxBufSize);
3097                 }
3098                 rc = -EAGAIN;
3099                 while (rc == -EAGAIN) {
3100                         if (open_file->invalidHandle) {
3101                                 rc = cifs_reopen_file(open_file, true);
3102                                 if (rc != 0)
3103                                         break;
3104                         }
3105                         io_parms.pid = pid;
3106                         io_parms.tcon = tcon;
3107                         io_parms.offset = *offset;
3108                         io_parms.length = current_read_size;
3109                         rc = server->ops->sync_read(xid, open_file, &io_parms,
3110                                                     &bytes_read, &cur_offset,
3111                                                     &buf_type);
3112                 }
3113                 if (rc || (bytes_read == 0)) {
3114                         if (total_read) {
3115                                 break;
3116                         } else {
3117                                 free_xid(xid);
3118                                 return rc;
3119                         }
3120                 } else {
3121                         cifs_stats_bytes_read(tcon, total_read);
3122                         *offset += bytes_read;
3123                 }
3124         }
3125         free_xid(xid);
3126         return total_read;
3127 }
3128
3129 /*
3130  * If the page is mmap'ed into a process' page tables, then we need to make
3131  * sure that it doesn't change while being written back.
3132  */
3133 static int
3134 cifs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
3135 {
3136         struct page *page = vmf->page;
3137
3138         lock_page(page);
3139         return VM_FAULT_LOCKED;
3140 }
3141
3142 static struct vm_operations_struct cifs_file_vm_ops = {
3143         .fault = filemap_fault,
3144         .map_pages = filemap_map_pages,
3145         .page_mkwrite = cifs_page_mkwrite,
3146         .remap_pages = generic_file_remap_pages,
3147 };
3148
3149 int cifs_file_strict_mmap(struct file *file, struct vm_area_struct *vma)
3150 {
3151         int rc, xid;
3152         struct inode *inode = file_inode(file);
3153
3154         xid = get_xid();
3155
3156         if (!CIFS_CACHE_READ(CIFS_I(inode))) {
3157                 rc = cifs_zap_mapping(inode);
3158                 if (rc)
3159                         return rc;
3160         }
3161
3162         rc = generic_file_mmap(file, vma);
3163         if (rc == 0)
3164                 vma->vm_ops = &cifs_file_vm_ops;
3165         free_xid(xid);
3166         return rc;
3167 }
3168
3169 int cifs_file_mmap(struct file *file, struct vm_area_struct *vma)
3170 {
3171         int rc, xid;
3172
3173         xid = get_xid();
3174         rc = cifs_revalidate_file(file);
3175         if (rc) {
3176                 cifs_dbg(FYI, "Validation prior to mmap failed, error=%d\n",
3177                          rc);
3178                 free_xid(xid);
3179                 return rc;
3180         }
3181         rc = generic_file_mmap(file, vma);
3182         if (rc == 0)
3183                 vma->vm_ops = &cifs_file_vm_ops;
3184         free_xid(xid);
3185         return rc;
3186 }
3187
3188 static void
3189 cifs_readv_complete(struct work_struct *work)
3190 {
3191         unsigned int i;
3192         struct cifs_readdata *rdata = container_of(work,
3193                                                 struct cifs_readdata, work);
3194
3195         for (i = 0; i < rdata->nr_pages; i++) {
3196                 struct page *page = rdata->pages[i];
3197
3198                 lru_cache_add_file(page);
3199
3200                 if (rdata->result == 0) {
3201                         flush_dcache_page(page);
3202                         SetPageUptodate(page);
3203                 }
3204
3205                 unlock_page(page);
3206
3207                 if (rdata->result == 0)
3208                         cifs_readpage_to_fscache(rdata->mapping->host, page);
3209
3210                 page_cache_release(page);
3211                 rdata->pages[i] = NULL;
3212         }
3213         kref_put(&rdata->refcount, cifs_readdata_release);
3214 }
3215
3216 static int
3217 cifs_readpages_read_into_pages(struct TCP_Server_Info *server,
3218                         struct cifs_readdata *rdata, unsigned int len)
3219 {
3220         int total_read = 0, result = 0;
3221         unsigned int i;
3222         u64 eof;
3223         pgoff_t eof_index;
3224         unsigned int nr_pages = rdata->nr_pages;
3225         struct kvec iov;
3226
3227         /* determine the eof that the server (probably) has */
3228         eof = CIFS_I(rdata->mapping->host)->server_eof;
3229         eof_index = eof ? (eof - 1) >> PAGE_CACHE_SHIFT : 0;
3230         cifs_dbg(FYI, "eof=%llu eof_index=%lu\n", eof, eof_index);
3231
3232         rdata->tailsz = PAGE_CACHE_SIZE;
3233         for (i = 0; i < nr_pages; i++) {
3234                 struct page *page = rdata->pages[i];
3235
3236                 if (len >= PAGE_CACHE_SIZE) {
3237                         /* enough data to fill the page */
3238                         iov.iov_base = kmap(page);
3239                         iov.iov_len = PAGE_CACHE_SIZE;
3240                         cifs_dbg(FYI, "%u: idx=%lu iov_base=%p iov_len=%zu\n",
3241                                  i, page->index, iov.iov_base, iov.iov_len);
3242                         len -= PAGE_CACHE_SIZE;
3243                 } else if (len > 0) {
3244                         /* enough for partial page, fill and zero the rest */
3245                         iov.iov_base = kmap(page);
3246                         iov.iov_len = len;
3247                         cifs_dbg(FYI, "%u: idx=%lu iov_base=%p iov_len=%zu\n",
3248                                  i, page->index, iov.iov_base, iov.iov_len);
3249                         memset(iov.iov_base + len,
3250                                 '\0', PAGE_CACHE_SIZE - len);
3251                         rdata->tailsz = len;
3252                         len = 0;
3253                 } else if (page->index > eof_index) {
3254                         /*
3255                          * The VFS will not try to do readahead past the
3256                          * i_size, but it's possible that we have outstanding
3257                          * writes with gaps in the middle and the i_size hasn't
3258                          * caught up yet. Populate those with zeroed out pages
3259                          * to prevent the VFS from repeatedly attempting to
3260                          * fill them until the writes are flushed.
3261                          */
3262                         zero_user(page, 0, PAGE_CACHE_SIZE);
3263                         lru_cache_add_file(page);
3264                         flush_dcache_page(page);
3265                         SetPageUptodate(page);
3266                         unlock_page(page);
3267                         page_cache_release(page);
3268                         rdata->pages[i] = NULL;
3269                         rdata->nr_pages--;
3270                         continue;
3271                 } else {
3272                         /* no need to hold page hostage */
3273                         lru_cache_add_file(page);
3274                         unlock_page(page);
3275                         page_cache_release(page);
3276                         rdata->pages[i] = NULL;
3277                         rdata->nr_pages--;
3278                         continue;
3279                 }
3280
3281                 result = cifs_readv_from_socket(server, &iov, 1, iov.iov_len);
3282                 kunmap(page);
3283                 if (result < 0)
3284                         break;
3285
3286                 total_read += result;
3287         }
3288
3289         return total_read > 0 && result != -EAGAIN ? total_read : result;
3290 }
3291
3292 static int cifs_readpages(struct file *file, struct address_space *mapping,
3293         struct list_head *page_list, unsigned num_pages)
3294 {
3295         int rc;
3296         struct list_head tmplist;
3297         struct cifsFileInfo *open_file = file->private_data;
3298         struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
3299         unsigned int rsize = cifs_sb->rsize;
3300         pid_t pid;
3301
3302         /*
3303          * Give up immediately if rsize is too small to read an entire page.
3304          * The VFS will fall back to readpage. We should never reach this
3305          * point however since we set ra_pages to 0 when the rsize is smaller
3306          * than a cache page.
3307          */
3308         if (unlikely(rsize < PAGE_CACHE_SIZE))
3309                 return 0;
3310
3311         /*
3312          * Reads as many pages as possible from fscache. Returns -ENOBUFS
3313          * immediately if the cookie is negative
3314          *
3315          * After this point, every page in the list might have PG_fscache set,
3316          * so we will need to clean that up off of every page we don't use.
3317          */
3318         rc = cifs_readpages_from_fscache(mapping->host, mapping, page_list,
3319                                          &num_pages);
3320         if (rc == 0)
3321                 return rc;
3322
3323         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
3324                 pid = open_file->pid;
3325         else
3326                 pid = current->tgid;
3327
3328         rc = 0;
3329         INIT_LIST_HEAD(&tmplist);
3330
3331         cifs_dbg(FYI, "%s: file=%p mapping=%p num_pages=%u\n",
3332                  __func__, file, mapping, num_pages);
3333
3334         /*
3335          * Start with the page at end of list and move it to private
3336          * list. Do the same with any following pages until we hit
3337          * the rsize limit, hit an index discontinuity, or run out of
3338          * pages. Issue the async read and then start the loop again
3339          * until the list is empty.
3340          *
3341          * Note that list order is important. The page_list is in
3342          * the order of declining indexes. When we put the pages in
3343          * the rdata->pages, then we want them in increasing order.
3344          */
3345         while (!list_empty(page_list)) {
3346                 unsigned int i;
3347                 unsigned int bytes = PAGE_CACHE_SIZE;
3348                 unsigned int expected_index;
3349                 unsigned int nr_pages = 1;
3350                 loff_t offset;
3351                 struct page *page, *tpage;
3352                 struct cifs_readdata *rdata;
3353
3354                 page = list_entry(page_list->prev, struct page, lru);
3355
3356                 /*
3357                  * Lock the page and put it in the cache. Since no one else
3358                  * should have access to this page, we're safe to simply set
3359                  * PG_locked without checking it first.
3360                  */
3361                 __set_page_locked(page);
3362                 rc = add_to_page_cache_locked(page, mapping,
3363                                               page->index, GFP_KERNEL);
3364
3365                 /* give up if we can't stick it in the cache */
3366                 if (rc) {
3367                         __clear_page_locked(page);
3368                         break;
3369                 }
3370
3371                 /* move first page to the tmplist */
3372                 offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
3373                 list_move_tail(&page->lru, &tmplist);
3374
3375                 /* now try and add more pages onto the request */
3376                 expected_index = page->index + 1;
3377                 list_for_each_entry_safe_reverse(page, tpage, page_list, lru) {
3378                         /* discontinuity ? */
3379                         if (page->index != expected_index)
3380                                 break;
3381
3382                         /* would this page push the read over the rsize? */
3383                         if (bytes + PAGE_CACHE_SIZE > rsize)
3384                                 break;
3385
3386                         __set_page_locked(page);
3387                         if (add_to_page_cache_locked(page, mapping,
3388                                                 page->index, GFP_KERNEL)) {
3389                                 __clear_page_locked(page);
3390                                 break;
3391                         }
3392                         list_move_tail(&page->lru, &tmplist);
3393                         bytes += PAGE_CACHE_SIZE;
3394                         expected_index++;
3395                         nr_pages++;
3396                 }
3397
3398                 rdata = cifs_readdata_alloc(nr_pages, cifs_readv_complete);
3399                 if (!rdata) {
3400                         /* best to give up if we're out of mem */
3401                         list_for_each_entry_safe(page, tpage, &tmplist, lru) {
3402                                 list_del(&page->lru);
3403                                 lru_cache_add_file(page);
3404                                 unlock_page(page);
3405                                 page_cache_release(page);
3406                         }
3407                         rc = -ENOMEM;
3408                         break;
3409                 }
3410
3411                 rdata->cfile = cifsFileInfo_get(open_file);
3412                 rdata->mapping = mapping;
3413                 rdata->offset = offset;
3414                 rdata->bytes = bytes;
3415                 rdata->pid = pid;
3416                 rdata->pagesz = PAGE_CACHE_SIZE;
3417                 rdata->read_into_pages = cifs_readpages_read_into_pages;
3418
3419                 list_for_each_entry_safe(page, tpage, &tmplist, lru) {
3420                         list_del(&page->lru);
3421                         rdata->pages[rdata->nr_pages++] = page;
3422                 }
3423
3424                 rc = cifs_retry_async_readv(rdata);
3425                 if (rc != 0) {
3426                         for (i = 0; i < rdata->nr_pages; i++) {
3427                                 page = rdata->pages[i];
3428                                 lru_cache_add_file(page);
3429                                 unlock_page(page);
3430                                 page_cache_release(page);
3431                         }
3432                         kref_put(&rdata->refcount, cifs_readdata_release);
3433                         break;
3434                 }
3435
3436                 kref_put(&rdata->refcount, cifs_readdata_release);
3437         }
3438
3439         /* Any pages that have been shown to fscache but didn't get added to
3440          * the pagecache must be uncached before they get returned to the
3441          * allocator.
3442          */
3443         cifs_fscache_readpages_cancel(mapping->host, page_list);
3444         return rc;
3445 }
3446
3447 /*
3448  * cifs_readpage_worker must be called with the page pinned
3449  */
3450 static int cifs_readpage_worker(struct file *file, struct page *page,
3451         loff_t *poffset)
3452 {
3453         char *read_data;
3454         int rc;
3455
3456         /* Is the page cached? */
3457         rc = cifs_readpage_from_fscache(file_inode(file), page);
3458         if (rc == 0)
3459                 goto read_complete;
3460
3461         read_data = kmap(page);
3462         /* for reads over a certain size could initiate async read ahead */
3463
3464         rc = cifs_read(file, read_data, PAGE_CACHE_SIZE, poffset);
3465
3466         if (rc < 0)
3467                 goto io_error;
3468         else
3469                 cifs_dbg(FYI, "Bytes read %d\n", rc);
3470
3471         file_inode(file)->i_atime =
3472                 current_fs_time(file_inode(file)->i_sb);
3473
3474         if (PAGE_CACHE_SIZE > rc)
3475                 memset(read_data + rc, 0, PAGE_CACHE_SIZE - rc);
3476
3477         flush_dcache_page(page);
3478         SetPageUptodate(page);
3479
3480         /* send this page to the cache */
3481         cifs_readpage_to_fscache(file_inode(file), page);
3482
3483         rc = 0;
3484
3485 io_error:
3486         kunmap(page);
3487         unlock_page(page);
3488
3489 read_complete:
3490         return rc;
3491 }
3492
3493 static int cifs_readpage(struct file *file, struct page *page)
3494 {
3495         loff_t offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
3496         int rc = -EACCES;
3497         unsigned int xid;
3498
3499         xid = get_xid();
3500
3501         if (file->private_data == NULL) {
3502                 rc = -EBADF;
3503                 free_xid(xid);
3504                 return rc;
3505         }
3506
3507         cifs_dbg(FYI, "readpage %p at offset %d 0x%x\n",
3508                  page, (int)offset, (int)offset);
3509
3510         rc = cifs_readpage_worker(file, page, &offset);
3511
3512         free_xid(xid);
3513         return rc;
3514 }
3515
3516 static int is_inode_writable(struct cifsInodeInfo *cifs_inode)
3517 {
3518         struct cifsFileInfo *open_file;
3519
3520         spin_lock(&cifs_file_list_lock);
3521         list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
3522                 if (OPEN_FMODE(open_file->f_flags) & FMODE_WRITE) {
3523                         spin_unlock(&cifs_file_list_lock);
3524                         return 1;
3525                 }
3526         }
3527         spin_unlock(&cifs_file_list_lock);
3528         return 0;
3529 }
3530
3531 /* We do not want to update the file size from server for inodes
3532    open for write - to avoid races with writepage extending
3533    the file - in the future we could consider allowing
3534    refreshing the inode only on increases in the file size
3535    but this is tricky to do without racing with writebehind
3536    page caching in the current Linux kernel design */
3537 bool is_size_safe_to_change(struct cifsInodeInfo *cifsInode, __u64 end_of_file)
3538 {
3539         if (!cifsInode)
3540                 return true;
3541
3542         if (is_inode_writable(cifsInode)) {
3543                 /* This inode is open for write at least once */
3544                 struct cifs_sb_info *cifs_sb;
3545
3546                 cifs_sb = CIFS_SB(cifsInode->vfs_inode.i_sb);
3547                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DIRECT_IO) {
3548                         /* since no page cache to corrupt on directio
3549                         we can change size safely */
3550                         return true;
3551                 }
3552
3553                 if (i_size_read(&cifsInode->vfs_inode) < end_of_file)
3554                         return true;
3555
3556                 return false;
3557         } else
3558                 return true;
3559 }
3560
3561 static int cifs_write_begin(struct file *file, struct address_space *mapping,
3562                         loff_t pos, unsigned len, unsigned flags,
3563                         struct page **pagep, void **fsdata)
3564 {
3565         int oncethru = 0;
3566         pgoff_t index = pos >> PAGE_CACHE_SHIFT;
3567         loff_t offset = pos & (PAGE_CACHE_SIZE - 1);
3568         loff_t page_start = pos & PAGE_MASK;
3569         loff_t i_size;
3570         struct page *page;
3571         int rc = 0;
3572
3573         cifs_dbg(FYI, "write_begin from %lld len %d\n", (long long)pos, len);
3574
3575 start:
3576         page = grab_cache_page_write_begin(mapping, index, flags);
3577         if (!page) {
3578                 rc = -ENOMEM;
3579                 goto out;
3580         }
3581
3582         if (PageUptodate(page))
3583                 goto out;
3584
3585         /*
3586          * If we write a full page it will be up to date, no need to read from
3587          * the server. If the write is short, we'll end up doing a sync write
3588          * instead.
3589          */
3590         if (len == PAGE_CACHE_SIZE)
3591                 goto out;
3592
3593         /*
3594          * optimize away the read when we have an oplock, and we're not
3595          * expecting to use any of the data we'd be reading in. That
3596          * is, when the page lies beyond the EOF, or straddles the EOF
3597          * and the write will cover all of the existing data.
3598          */
3599         if (CIFS_CACHE_READ(CIFS_I(mapping->host))) {
3600                 i_size = i_size_read(mapping->host);
3601                 if (page_start >= i_size ||
3602                     (offset == 0 && (pos + len) >= i_size)) {
3603                         zero_user_segments(page, 0, offset,
3604                                            offset + len,
3605                                            PAGE_CACHE_SIZE);
3606                         /*
3607                          * PageChecked means that the parts of the page
3608                          * to which we're not writing are considered up
3609                          * to date. Once the data is copied to the
3610                          * page, it can be set uptodate.
3611                          */
3612                         SetPageChecked(page);
3613                         goto out;
3614                 }
3615         }
3616
3617         if ((file->f_flags & O_ACCMODE) != O_WRONLY && !oncethru) {
3618                 /*
3619                  * might as well read a page, it is fast enough. If we get
3620                  * an error, we don't need to return it. cifs_write_end will
3621                  * do a sync write instead since PG_uptodate isn't set.
3622                  */
3623                 cifs_readpage_worker(file, page, &page_start);
3624                 page_cache_release(page);
3625                 oncethru = 1;
3626                 goto start;
3627         } else {
3628                 /* we could try using another file handle if there is one -
3629                    but how would we lock it to prevent close of that handle
3630                    racing with this read? In any case
3631                    this will be written out by write_end so is fine */
3632         }
3633 out:
3634         *pagep = page;
3635         return rc;
3636 }
3637
3638 static int cifs_release_page(struct page *page, gfp_t gfp)
3639 {
3640         if (PagePrivate(page))
3641                 return 0;
3642
3643         return cifs_fscache_release_page(page, gfp);
3644 }
3645
3646 static void cifs_invalidate_page(struct page *page, unsigned int offset,
3647                                  unsigned int length)
3648 {
3649         struct cifsInodeInfo *cifsi = CIFS_I(page->mapping->host);
3650
3651         if (offset == 0 && length == PAGE_CACHE_SIZE)
3652                 cifs_fscache_invalidate_page(page, &cifsi->vfs_inode);
3653 }
3654
3655 static int cifs_launder_page(struct page *page)
3656 {
3657         int rc = 0;
3658         loff_t range_start = page_offset(page);
3659         loff_t range_end = range_start + (loff_t)(PAGE_CACHE_SIZE - 1);
3660         struct writeback_control wbc = {
3661                 .sync_mode = WB_SYNC_ALL,
3662                 .nr_to_write = 0,
3663                 .range_start = range_start,
3664                 .range_end = range_end,
3665         };
3666
3667         cifs_dbg(FYI, "Launder page: %p\n", page);
3668
3669         if (clear_page_dirty_for_io(page))
3670                 rc = cifs_writepage_locked(page, &wbc);
3671
3672         cifs_fscache_invalidate_page(page, page->mapping->host);
3673         return rc;
3674 }
3675
3676 static int
3677 cifs_pending_writers_wait(void *unused)
3678 {
3679         schedule();
3680         return 0;
3681 }
3682
3683 void cifs_oplock_break(struct work_struct *work)
3684 {
3685         struct cifsFileInfo *cfile = container_of(work, struct cifsFileInfo,
3686                                                   oplock_break);
3687         struct inode *inode = cfile->dentry->d_inode;
3688         struct cifsInodeInfo *cinode = CIFS_I(inode);
3689         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
3690         struct TCP_Server_Info *server = tcon->ses->server;
3691         int rc = 0;
3692
3693         wait_on_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS,
3694                         cifs_pending_writers_wait, TASK_UNINTERRUPTIBLE);
3695
3696         server->ops->downgrade_oplock(server, cinode,
3697                 test_bit(CIFS_INODE_DOWNGRADE_OPLOCK_TO_L2, &cinode->flags));
3698
3699         if (!CIFS_CACHE_WRITE(cinode) && CIFS_CACHE_READ(cinode) &&
3700                                                 cifs_has_mand_locks(cinode)) {
3701                 cifs_dbg(FYI, "Reset oplock to None for inode=%p due to mand locks\n",
3702                          inode);
3703                 cinode->oplock = 0;
3704         }
3705
3706         if (inode && S_ISREG(inode->i_mode)) {
3707                 if (CIFS_CACHE_READ(cinode))
3708                         break_lease(inode, O_RDONLY);
3709                 else
3710                         break_lease(inode, O_WRONLY);
3711                 rc = filemap_fdatawrite(inode->i_mapping);
3712                 if (!CIFS_CACHE_READ(cinode)) {
3713                         rc = filemap_fdatawait(inode->i_mapping);
3714                         mapping_set_error(inode->i_mapping, rc);
3715                         cifs_zap_mapping(inode);
3716                 }
3717                 cifs_dbg(FYI, "Oplock flush inode %p rc %d\n", inode, rc);
3718         }
3719
3720         rc = cifs_push_locks(cfile);
3721         if (rc)
3722                 cifs_dbg(VFS, "Push locks rc = %d\n", rc);
3723
3724         /*
3725          * releasing stale oplock after recent reconnect of smb session using
3726          * a now incorrect file handle is not a data integrity issue but do
3727          * not bother sending an oplock release if session to server still is
3728          * disconnected since oplock already released by the server
3729          */
3730         if (!cfile->oplock_break_cancelled) {
3731                 rc = tcon->ses->server->ops->oplock_response(tcon, &cfile->fid,
3732                                                              cinode);
3733                 cifs_dbg(FYI, "Oplock release rc = %d\n", rc);
3734         }
3735         cifs_done_oplock_break(cinode);
3736 }
3737
3738 /*
3739  * The presence of cifs_direct_io() in the address space ops vector
3740  * allowes open() O_DIRECT flags which would have failed otherwise.
3741  *
3742  * In the non-cached mode (mount with cache=none), we shunt off direct read and write requests
3743  * so this method should never be called.
3744  *
3745  * Direct IO is not yet supported in the cached mode.
3746  */
3747 static ssize_t
3748 cifs_direct_io(int rw, struct kiocb *iocb, struct iov_iter *iter,
3749                loff_t pos)
3750 {
3751         /*
3752          * FIXME
3753          * Eventually need to support direct IO for non forcedirectio mounts
3754          */
3755         return -EINVAL;
3756 }
3757
3758
3759 const struct address_space_operations cifs_addr_ops = {
3760         .readpage = cifs_readpage,
3761         .readpages = cifs_readpages,
3762         .writepage = cifs_writepage,
3763         .writepages = cifs_writepages,
3764         .write_begin = cifs_write_begin,
3765         .write_end = cifs_write_end,
3766         .set_page_dirty = __set_page_dirty_nobuffers,
3767         .releasepage = cifs_release_page,
3768         .direct_IO = cifs_direct_io,
3769         .invalidatepage = cifs_invalidate_page,
3770         .launder_page = cifs_launder_page,
3771 };
3772
3773 /*
3774  * cifs_readpages requires the server to support a buffer large enough to
3775  * contain the header plus one complete page of data.  Otherwise, we need
3776  * to leave cifs_readpages out of the address space operations.
3777  */
3778 const struct address_space_operations cifs_addr_ops_smallbuf = {
3779         .readpage = cifs_readpage,
3780         .writepage = cifs_writepage,
3781         .writepages = cifs_writepages,
3782         .write_begin = cifs_write_begin,
3783         .write_end = cifs_write_end,
3784         .set_page_dirty = __set_page_dirty_nobuffers,
3785         .releasepage = cifs_release_page,
3786         .invalidatepage = cifs_invalidate_page,
3787         .launder_page = cifs_launder_page,
3788 };