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->netfid);
 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_invalidate_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                         CIFS_I(inode)->invalid_mapping = true;
 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          * CIFSSMBOpen 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_invalidate_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 int cifs_writepages(struct address_space *mapping,
1882                            struct writeback_control *wbc)
1883 {
1884         struct cifs_sb_info *cifs_sb = CIFS_SB(mapping->host->i_sb);
1885         bool done = false, scanned = false, range_whole = false;
1886         pgoff_t end, index;
1887         struct cifs_writedata *wdata;
1888         struct TCP_Server_Info *server;
1889         struct page *page;
1890         int rc = 0;
1891
1892         /*
1893          * If wsize is smaller than the page cache size, default to writing
1894          * one page at a time via cifs_writepage
1895          */
1896         if (cifs_sb->wsize < PAGE_CACHE_SIZE)
1897                 return generic_writepages(mapping, wbc);
1898
1899         if (wbc->range_cyclic) {
1900                 index = mapping->writeback_index; /* Start from prev offset */
1901                 end = -1;
1902         } else {
1903                 index = wbc->range_start >> PAGE_CACHE_SHIFT;
1904                 end = wbc->range_end >> PAGE_CACHE_SHIFT;
1905                 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
1906                         range_whole = true;
1907                 scanned = true;
1908         }
1909 retry:
1910         while (!done && index <= end) {
1911                 unsigned int i, nr_pages, found_pages;
1912                 pgoff_t next = 0, tofind;
1913                 struct page **pages;
1914
1915                 tofind = min((cifs_sb->wsize / PAGE_CACHE_SIZE) - 1,
1916                                 end - index) + 1;
1917
1918                 wdata = cifs_writedata_alloc((unsigned int)tofind,
1919                                              cifs_writev_complete);
1920                 if (!wdata) {
1921                         rc = -ENOMEM;
1922                         break;
1923                 }
1924
1925                 /*
1926                  * find_get_pages_tag seems to return a max of 256 on each
1927                  * iteration, so we must call it several times in order to
1928                  * fill the array or the wsize is effectively limited to
1929                  * 256 * PAGE_CACHE_SIZE.
1930                  */
1931                 found_pages = 0;
1932                 pages = wdata->pages;
1933                 do {
1934                         nr_pages = find_get_pages_tag(mapping, &index,
1935                                                         PAGECACHE_TAG_DIRTY,
1936                                                         tofind, pages);
1937                         found_pages += nr_pages;
1938                         tofind -= nr_pages;
1939                         pages += nr_pages;
1940                 } while (nr_pages && tofind && index <= end);
1941
1942                 if (found_pages == 0) {
1943                         kref_put(&wdata->refcount, cifs_writedata_release);
1944                         break;
1945                 }
1946
1947                 nr_pages = 0;
1948                 for (i = 0; i < found_pages; i++) {
1949                         page = wdata->pages[i];
1950                         /*
1951                          * At this point we hold neither mapping->tree_lock nor
1952                          * lock on the page itself: the page may be truncated or
1953                          * invalidated (changing page->mapping to NULL), or even
1954                          * swizzled back from swapper_space to tmpfs file
1955                          * mapping
1956                          */
1957
1958                         if (nr_pages == 0)
1959                                 lock_page(page);
1960                         else if (!trylock_page(page))
1961                                 break;
1962
1963                         if (unlikely(page->mapping != mapping)) {
1964                                 unlock_page(page);
1965                                 break;
1966                         }
1967
1968                         if (!wbc->range_cyclic && page->index > end) {
1969                                 done = true;
1970                                 unlock_page(page);
1971                                 break;
1972                         }
1973
1974                         if (next && (page->index != next)) {
1975                                 /* Not next consecutive page */
1976                                 unlock_page(page);
1977                                 break;
1978                         }
1979
1980                         if (wbc->sync_mode != WB_SYNC_NONE)
1981                                 wait_on_page_writeback(page);
1982
1983                         if (PageWriteback(page) ||
1984                                         !clear_page_dirty_for_io(page)) {
1985                                 unlock_page(page);
1986                                 break;
1987                         }
1988
1989                         /*
1990                          * This actually clears the dirty bit in the radix tree.
1991                          * See cifs_writepage() for more commentary.
1992                          */
1993                         set_page_writeback(page);
1994
1995                         if (page_offset(page) >= i_size_read(mapping->host)) {
1996                                 done = true;
1997                                 unlock_page(page);
1998                                 end_page_writeback(page);
1999                                 break;
2000                         }
2001
2002                         wdata->pages[i] = page;
2003                         next = page->index + 1;
2004                         ++nr_pages;
2005                 }
2006
2007                 /* reset index to refind any pages skipped */
2008                 if (nr_pages == 0)
2009                         index = wdata->pages[0]->index + 1;
2010
2011                 /* put any pages we aren't going to use */
2012                 for (i = nr_pages; i < found_pages; i++) {
2013                         page_cache_release(wdata->pages[i]);
2014                         wdata->pages[i] = NULL;
2015                 }
2016
2017                 /* nothing to write? */
2018                 if (nr_pages == 0) {
2019                         kref_put(&wdata->refcount, cifs_writedata_release);
2020                         continue;
2021                 }
2022
2023                 wdata->sync_mode = wbc->sync_mode;
2024                 wdata->nr_pages = nr_pages;
2025                 wdata->offset = page_offset(wdata->pages[0]);
2026                 wdata->pagesz = PAGE_CACHE_SIZE;
2027                 wdata->tailsz =
2028                         min(i_size_read(mapping->host) -
2029                             page_offset(wdata->pages[nr_pages - 1]),
2030                             (loff_t)PAGE_CACHE_SIZE);
2031                 wdata->bytes = ((nr_pages - 1) * PAGE_CACHE_SIZE) +
2032                                         wdata->tailsz;
2033
2034                 do {
2035                         if (wdata->cfile != NULL)
2036                                 cifsFileInfo_put(wdata->cfile);
2037                         wdata->cfile = find_writable_file(CIFS_I(mapping->host),
2038                                                           false);
2039                         if (!wdata->cfile) {
2040                                 cifs_dbg(VFS, "No writable handles for inode\n");
2041                                 rc = -EBADF;
2042                                 break;
2043                         }
2044                         wdata->pid = wdata->cfile->pid;
2045                         server = tlink_tcon(wdata->cfile->tlink)->ses->server;
2046                         rc = server->ops->async_writev(wdata);
2047                 } while (wbc->sync_mode == WB_SYNC_ALL && rc == -EAGAIN);
2048
2049                 for (i = 0; i < nr_pages; ++i)
2050                         unlock_page(wdata->pages[i]);
2051
2052                 /* send failure -- clean up the mess */
2053                 if (rc != 0) {
2054                         for (i = 0; i < nr_pages; ++i) {
2055                                 if (rc == -EAGAIN)
2056                                         redirty_page_for_writepage(wbc,
2057                                                            wdata->pages[i]);
2058                                 else
2059                                         SetPageError(wdata->pages[i]);
2060                                 end_page_writeback(wdata->pages[i]);
2061                                 page_cache_release(wdata->pages[i]);
2062                         }
2063                         if (rc != -EAGAIN)
2064                                 mapping_set_error(mapping, rc);
2065                 }
2066                 kref_put(&wdata->refcount, cifs_writedata_release);
2067
2068                 wbc->nr_to_write -= nr_pages;
2069                 if (wbc->nr_to_write <= 0)
2070                         done = true;
2071
2072                 index = next;
2073         }
2074
2075         if (!scanned && !done) {
2076                 /*
2077                  * We hit the last page and there is more work to be done: wrap
2078                  * back to the start of the file
2079                  */
2080                 scanned = true;
2081                 index = 0;
2082                 goto retry;
2083         }
2084
2085         if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
2086                 mapping->writeback_index = index;
2087
2088         return rc;
2089 }
2090
2091 static int
2092 cifs_writepage_locked(struct page *page, struct writeback_control *wbc)
2093 {
2094         int rc;
2095         unsigned int xid;
2096
2097         xid = get_xid();
2098 /* BB add check for wbc flags */
2099         page_cache_get(page);
2100         if (!PageUptodate(page))
2101                 cifs_dbg(FYI, "ppw - page not up to date\n");
2102
2103         /*
2104          * Set the "writeback" flag, and clear "dirty" in the radix tree.
2105          *
2106          * A writepage() implementation always needs to do either this,
2107          * or re-dirty the page with "redirty_page_for_writepage()" in
2108          * the case of a failure.
2109          *
2110          * Just unlocking the page will cause the radix tree tag-bits
2111          * to fail to update with the state of the page correctly.
2112          */
2113         set_page_writeback(page);
2114 retry_write:
2115         rc = cifs_partialpagewrite(page, 0, PAGE_CACHE_SIZE);
2116         if (rc == -EAGAIN && wbc->sync_mode == WB_SYNC_ALL)
2117                 goto retry_write;
2118         else if (rc == -EAGAIN)
2119                 redirty_page_for_writepage(wbc, page);
2120         else if (rc != 0)
2121                 SetPageError(page);
2122         else
2123                 SetPageUptodate(page);
2124         end_page_writeback(page);
2125         page_cache_release(page);
2126         free_xid(xid);
2127         return rc;
2128 }
2129
2130 static int cifs_writepage(struct page *page, struct writeback_control *wbc)
2131 {
2132         int rc = cifs_writepage_locked(page, wbc);
2133         unlock_page(page);
2134         return rc;
2135 }
2136
2137 static int cifs_write_end(struct file *file, struct address_space *mapping,
2138                         loff_t pos, unsigned len, unsigned copied,
2139                         struct page *page, void *fsdata)
2140 {
2141         int rc;
2142         struct inode *inode = mapping->host;
2143         struct cifsFileInfo *cfile = file->private_data;
2144         struct cifs_sb_info *cifs_sb = CIFS_SB(cfile->dentry->d_sb);
2145         __u32 pid;
2146
2147         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
2148                 pid = cfile->pid;
2149         else
2150                 pid = current->tgid;
2151
2152         cifs_dbg(FYI, "write_end for page %p from pos %lld with %d bytes\n",
2153                  page, pos, copied);
2154
2155         if (PageChecked(page)) {
2156                 if (copied == len)
2157                         SetPageUptodate(page);
2158                 ClearPageChecked(page);
2159         } else if (!PageUptodate(page) && copied == PAGE_CACHE_SIZE)
2160                 SetPageUptodate(page);
2161
2162         if (!PageUptodate(page)) {
2163                 char *page_data;
2164                 unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
2165                 unsigned int xid;
2166
2167                 xid = get_xid();
2168                 /* this is probably better than directly calling
2169                    partialpage_write since in this function the file handle is
2170                    known which we might as well leverage */
2171                 /* BB check if anything else missing out of ppw
2172                    such as updating last write time */
2173                 page_data = kmap(page);
2174                 rc = cifs_write(cfile, pid, page_data + offset, copied, &pos);
2175                 /* if (rc < 0) should we set writebehind rc? */
2176                 kunmap(page);
2177
2178                 free_xid(xid);
2179         } else {
2180                 rc = copied;
2181                 pos += copied;
2182                 set_page_dirty(page);
2183         }
2184
2185         if (rc > 0) {
2186                 spin_lock(&inode->i_lock);
2187                 if (pos > inode->i_size)
2188                         i_size_write(inode, pos);
2189                 spin_unlock(&inode->i_lock);
2190         }
2191
2192         unlock_page(page);
2193         page_cache_release(page);
2194
2195         return rc;
2196 }
2197
2198 int cifs_strict_fsync(struct file *file, loff_t start, loff_t end,
2199                       int datasync)
2200 {
2201         unsigned int xid;
2202         int rc = 0;
2203         struct cifs_tcon *tcon;
2204         struct TCP_Server_Info *server;
2205         struct cifsFileInfo *smbfile = file->private_data;
2206         struct inode *inode = file_inode(file);
2207         struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
2208
2209         rc = filemap_write_and_wait_range(inode->i_mapping, start, end);
2210         if (rc)
2211                 return rc;
2212         mutex_lock(&inode->i_mutex);
2213
2214         xid = get_xid();
2215
2216         cifs_dbg(FYI, "Sync file - name: %s datasync: 0x%x\n",
2217                  file->f_path.dentry->d_name.name, datasync);
2218
2219         if (!CIFS_CACHE_READ(CIFS_I(inode))) {
2220                 rc = cifs_invalidate_mapping(inode);
2221                 if (rc) {
2222                         cifs_dbg(FYI, "rc: %d during invalidate phase\n", rc);
2223                         rc = 0; /* don't care about it in fsync */
2224                 }
2225         }
2226
2227         tcon = tlink_tcon(smbfile->tlink);
2228         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC)) {
2229                 server = tcon->ses->server;
2230                 if (server->ops->flush)
2231                         rc = server->ops->flush(xid, tcon, &smbfile->fid);
2232                 else
2233                         rc = -ENOSYS;
2234         }
2235
2236         free_xid(xid);
2237         mutex_unlock(&inode->i_mutex);
2238         return rc;
2239 }
2240
2241 int cifs_fsync(struct file *file, loff_t start, loff_t end, int datasync)
2242 {
2243         unsigned int xid;
2244         int rc = 0;
2245         struct cifs_tcon *tcon;
2246         struct TCP_Server_Info *server;
2247         struct cifsFileInfo *smbfile = file->private_data;
2248         struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
2249         struct inode *inode = file->f_mapping->host;
2250
2251         rc = filemap_write_and_wait_range(inode->i_mapping, start, end);
2252         if (rc)
2253                 return rc;
2254         mutex_lock(&inode->i_mutex);
2255
2256         xid = get_xid();
2257
2258         cifs_dbg(FYI, "Sync file - name: %s datasync: 0x%x\n",
2259                  file->f_path.dentry->d_name.name, datasync);
2260
2261         tcon = tlink_tcon(smbfile->tlink);
2262         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC)) {
2263                 server = tcon->ses->server;
2264                 if (server->ops->flush)
2265                         rc = server->ops->flush(xid, tcon, &smbfile->fid);
2266                 else
2267                         rc = -ENOSYS;
2268         }
2269
2270         free_xid(xid);
2271         mutex_unlock(&inode->i_mutex);
2272         return rc;
2273 }
2274
2275 /*
2276  * As file closes, flush all cached write data for this inode checking
2277  * for write behind errors.
2278  */
2279 int cifs_flush(struct file *file, fl_owner_t id)
2280 {
2281         struct inode *inode = file_inode(file);
2282         int rc = 0;
2283
2284         if (file->f_mode & FMODE_WRITE)
2285                 rc = filemap_write_and_wait(inode->i_mapping);
2286
2287         cifs_dbg(FYI, "Flush inode %p file %p rc %d\n", inode, file, rc);
2288
2289         return rc;
2290 }
2291
2292 static int
2293 cifs_write_allocate_pages(struct page **pages, unsigned long num_pages)
2294 {
2295         int rc = 0;
2296         unsigned long i;
2297
2298         for (i = 0; i < num_pages; i++) {
2299                 pages[i] = alloc_page(GFP_KERNEL|__GFP_HIGHMEM);
2300                 if (!pages[i]) {
2301                         /*
2302                          * save number of pages we have already allocated and
2303                          * return with ENOMEM error
2304                          */
2305                         num_pages = i;
2306                         rc = -ENOMEM;
2307                         break;
2308                 }
2309         }
2310
2311         if (rc) {
2312                 for (i = 0; i < num_pages; i++)
2313                         put_page(pages[i]);
2314         }
2315         return rc;
2316 }
2317
2318 static inline
2319 size_t get_numpages(const size_t wsize, const size_t len, size_t *cur_len)
2320 {
2321         size_t num_pages;
2322         size_t clen;
2323
2324         clen = min_t(const size_t, len, wsize);
2325         num_pages = DIV_ROUND_UP(clen, PAGE_SIZE);
2326
2327         if (cur_len)
2328                 *cur_len = clen;
2329
2330         return num_pages;
2331 }
2332
2333 static void
2334 cifs_uncached_writev_complete(struct work_struct *work)
2335 {
2336         int i;
2337         struct cifs_writedata *wdata = container_of(work,
2338                                         struct cifs_writedata, work);
2339         struct inode *inode = wdata->cfile->dentry->d_inode;
2340         struct cifsInodeInfo *cifsi = CIFS_I(inode);
2341
2342         spin_lock(&inode->i_lock);
2343         cifs_update_eof(cifsi, wdata->offset, wdata->bytes);
2344         if (cifsi->server_eof > inode->i_size)
2345                 i_size_write(inode, cifsi->server_eof);
2346         spin_unlock(&inode->i_lock);
2347
2348         complete(&wdata->done);
2349
2350         if (wdata->result != -EAGAIN) {
2351                 for (i = 0; i < wdata->nr_pages; i++)
2352                         put_page(wdata->pages[i]);
2353         }
2354
2355         kref_put(&wdata->refcount, cifs_writedata_release);
2356 }
2357
2358 /* attempt to send write to server, retry on any -EAGAIN errors */
2359 static int
2360 cifs_uncached_retry_writev(struct cifs_writedata *wdata)
2361 {
2362         int rc;
2363         struct TCP_Server_Info *server;
2364
2365         server = tlink_tcon(wdata->cfile->tlink)->ses->server;
2366
2367         do {
2368                 if (wdata->cfile->invalidHandle) {
2369                         rc = cifs_reopen_file(wdata->cfile, false);
2370                         if (rc != 0)
2371                                 continue;
2372                 }
2373                 rc = server->ops->async_writev(wdata);
2374         } while (rc == -EAGAIN);
2375
2376         return rc;
2377 }
2378
2379 static ssize_t
2380 cifs_iovec_write(struct file *file, const struct iovec *iov,
2381                  unsigned long nr_segs, loff_t *poffset)
2382 {
2383         unsigned long nr_pages, i;
2384         size_t copied, len, cur_len;
2385         ssize_t total_written = 0;
2386         loff_t offset;
2387         struct iov_iter it;
2388         struct cifsFileInfo *open_file;
2389         struct cifs_tcon *tcon;
2390         struct cifs_sb_info *cifs_sb;
2391         struct cifs_writedata *wdata, *tmp;
2392         struct list_head wdata_list;
2393         int rc;
2394         pid_t pid;
2395
2396         len = iov_length(iov, nr_segs);
2397         if (!len)
2398                 return 0;
2399
2400         rc = generic_write_checks(file, poffset, &len, 0);
2401         if (rc)
2402                 return rc;
2403
2404         INIT_LIST_HEAD(&wdata_list);
2405         cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
2406         open_file = file->private_data;
2407         tcon = tlink_tcon(open_file->tlink);
2408
2409         if (!tcon->ses->server->ops->async_writev)
2410                 return -ENOSYS;
2411
2412         offset = *poffset;
2413
2414         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
2415                 pid = open_file->pid;
2416         else
2417                 pid = current->tgid;
2418
2419         iov_iter_init(&it, iov, nr_segs, len, 0);
2420         do {
2421                 size_t save_len;
2422
2423                 nr_pages = get_numpages(cifs_sb->wsize, len, &cur_len);
2424                 wdata = cifs_writedata_alloc(nr_pages,
2425                                              cifs_uncached_writev_complete);
2426                 if (!wdata) {
2427                         rc = -ENOMEM;
2428                         break;
2429                 }
2430
2431                 rc = cifs_write_allocate_pages(wdata->pages, nr_pages);
2432                 if (rc) {
2433                         kfree(wdata);
2434                         break;
2435                 }
2436
2437                 save_len = cur_len;
2438                 for (i = 0; i < nr_pages; i++) {
2439                         copied = min_t(const size_t, cur_len, PAGE_SIZE);
2440                         copied = iov_iter_copy_from_user(wdata->pages[i], &it,
2441                                                          0, copied);
2442                         cur_len -= copied;
2443                         iov_iter_advance(&it, copied);
2444                 }
2445                 cur_len = save_len - cur_len;
2446
2447                 wdata->sync_mode = WB_SYNC_ALL;
2448                 wdata->nr_pages = nr_pages;
2449                 wdata->offset = (__u64)offset;
2450                 wdata->cfile = cifsFileInfo_get(open_file);
2451                 wdata->pid = pid;
2452                 wdata->bytes = cur_len;
2453                 wdata->pagesz = PAGE_SIZE;
2454                 wdata->tailsz = cur_len - ((nr_pages - 1) * PAGE_SIZE);
2455                 rc = cifs_uncached_retry_writev(wdata);
2456                 if (rc) {
2457                         kref_put(&wdata->refcount, cifs_writedata_release);
2458                         break;
2459                 }
2460
2461                 list_add_tail(&wdata->list, &wdata_list);
2462                 offset += cur_len;
2463                 len -= cur_len;
2464         } while (len > 0);
2465
2466         /*
2467          * If at least one write was successfully sent, then discard any rc
2468          * value from the later writes. If the other write succeeds, then
2469          * we'll end up returning whatever was written. If it fails, then
2470          * we'll get a new rc value from that.
2471          */
2472         if (!list_empty(&wdata_list))
2473                 rc = 0;
2474
2475         /*
2476          * Wait for and collect replies for any successful sends in order of
2477          * increasing offset. Once an error is hit or we get a fatal signal
2478          * while waiting, then return without waiting for any more replies.
2479          */
2480 restart_loop:
2481         list_for_each_entry_safe(wdata, tmp, &wdata_list, list) {
2482                 if (!rc) {
2483                         /* FIXME: freezable too? */
2484                         rc = wait_for_completion_killable(&wdata->done);
2485                         if (rc)
2486                                 rc = -EINTR;
2487                         else if (wdata->result)
2488                                 rc = wdata->result;
2489                         else
2490                                 total_written += wdata->bytes;
2491
2492                         /* resend call if it's a retryable error */
2493                         if (rc == -EAGAIN) {
2494                                 rc = cifs_uncached_retry_writev(wdata);
2495                                 goto restart_loop;
2496                         }
2497                 }
2498                 list_del_init(&wdata->list);
2499                 kref_put(&wdata->refcount, cifs_writedata_release);
2500         }
2501
2502         if (total_written > 0)
2503                 *poffset += total_written;
2504
2505         cifs_stats_bytes_written(tcon, total_written);
2506         return total_written ? total_written : (ssize_t)rc;
2507 }
2508
2509 ssize_t cifs_user_writev(struct kiocb *iocb, const struct iovec *iov,
2510                                 unsigned long nr_segs, loff_t pos)
2511 {
2512         ssize_t written;
2513         struct inode *inode;
2514
2515         inode = file_inode(iocb->ki_filp);
2516
2517         /*
2518          * BB - optimize the way when signing is disabled. We can drop this
2519          * extra memory-to-memory copying and use iovec buffers for constructing
2520          * write request.
2521          */
2522
2523         written = cifs_iovec_write(iocb->ki_filp, iov, nr_segs, &pos);
2524         if (written > 0) {
2525                 CIFS_I(inode)->invalid_mapping = true;
2526                 iocb->ki_pos = pos;
2527         }
2528
2529         return written;
2530 }
2531
2532 static ssize_t
2533 cifs_writev(struct kiocb *iocb, const struct iovec *iov,
2534             unsigned long nr_segs, loff_t pos)
2535 {
2536         struct file *file = iocb->ki_filp;
2537         struct cifsFileInfo *cfile = (struct cifsFileInfo *)file->private_data;
2538         struct inode *inode = file->f_mapping->host;
2539         struct cifsInodeInfo *cinode = CIFS_I(inode);
2540         struct TCP_Server_Info *server = tlink_tcon(cfile->tlink)->ses->server;
2541         ssize_t rc = -EACCES;
2542
2543         BUG_ON(iocb->ki_pos != pos);
2544
2545         /*
2546          * We need to hold the sem to be sure nobody modifies lock list
2547          * with a brlock that prevents writing.
2548          */
2549         down_read(&cinode->lock_sem);
2550         if (!cifs_find_lock_conflict(cfile, pos, iov_length(iov, nr_segs),
2551                                      server->vals->exclusive_lock_type, NULL,
2552                                      CIFS_WRITE_OP)) {
2553                 mutex_lock(&inode->i_mutex);
2554                 rc = __generic_file_aio_write(iocb, iov, nr_segs,
2555                                                &iocb->ki_pos);
2556                 mutex_unlock(&inode->i_mutex);
2557         }
2558
2559         if (rc > 0) {
2560                 ssize_t err;
2561
2562                 err = generic_write_sync(file, pos, rc);
2563                 if (err < 0 && rc > 0)
2564                         rc = err;
2565         }
2566
2567         up_read(&cinode->lock_sem);
2568         return rc;
2569 }
2570
2571 ssize_t
2572 cifs_strict_writev(struct kiocb *iocb, const struct iovec *iov,
2573                    unsigned long nr_segs, loff_t pos)
2574 {
2575         struct inode *inode = file_inode(iocb->ki_filp);
2576         struct cifsInodeInfo *cinode = CIFS_I(inode);
2577         struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
2578         struct cifsFileInfo *cfile = (struct cifsFileInfo *)
2579                                                 iocb->ki_filp->private_data;
2580         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
2581         ssize_t written;
2582
2583         if (CIFS_CACHE_WRITE(cinode)) {
2584                 if (cap_unix(tcon->ses) &&
2585                 (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability))
2586                     && ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
2587                         return generic_file_aio_write(iocb, iov, nr_segs, pos);
2588                 return cifs_writev(iocb, iov, nr_segs, pos);
2589         }
2590         /*
2591          * For non-oplocked files in strict cache mode we need to write the data
2592          * to the server exactly from the pos to pos+len-1 rather than flush all
2593          * affected pages because it may cause a error with mandatory locks on
2594          * these pages but not on the region from pos to ppos+len-1.
2595          */
2596         written = cifs_user_writev(iocb, iov, nr_segs, pos);
2597         if (written > 0 && CIFS_CACHE_READ(cinode)) {
2598                 /*
2599                  * Windows 7 server can delay breaking level2 oplock if a write
2600                  * request comes - break it on the client to prevent reading
2601                  * an old data.
2602                  */
2603                 cifs_invalidate_mapping(inode);
2604                 cifs_dbg(FYI, "Set no oplock for inode=%p after a write operation\n",
2605                          inode);
2606                 cinode->oplock = 0;
2607         }
2608         return written;
2609 }
2610
2611 static struct cifs_readdata *
2612 cifs_readdata_alloc(unsigned int nr_pages, work_func_t complete)
2613 {
2614         struct cifs_readdata *rdata;
2615
2616         rdata = kzalloc(sizeof(*rdata) + (sizeof(struct page *) * nr_pages),
2617                         GFP_KERNEL);
2618         if (rdata != NULL) {
2619                 kref_init(&rdata->refcount);
2620                 INIT_LIST_HEAD(&rdata->list);
2621                 init_completion(&rdata->done);
2622                 INIT_WORK(&rdata->work, complete);
2623         }
2624
2625         return rdata;
2626 }
2627
2628 void
2629 cifs_readdata_release(struct kref *refcount)
2630 {
2631         struct cifs_readdata *rdata = container_of(refcount,
2632                                         struct cifs_readdata, refcount);
2633
2634         if (rdata->cfile)
2635                 cifsFileInfo_put(rdata->cfile);
2636
2637         kfree(rdata);
2638 }
2639
2640 static int
2641 cifs_read_allocate_pages(struct cifs_readdata *rdata, unsigned int nr_pages)
2642 {
2643         int rc = 0;
2644         struct page *page;
2645         unsigned int i;
2646
2647         for (i = 0; i < nr_pages; i++) {
2648                 page = alloc_page(GFP_KERNEL|__GFP_HIGHMEM);
2649                 if (!page) {
2650                         rc = -ENOMEM;
2651                         break;
2652                 }
2653                 rdata->pages[i] = page;
2654         }
2655
2656         if (rc) {
2657                 for (i = 0; i < nr_pages; i++) {
2658                         put_page(rdata->pages[i]);
2659                         rdata->pages[i] = NULL;
2660                 }
2661         }
2662         return rc;
2663 }
2664
2665 static void
2666 cifs_uncached_readdata_release(struct kref *refcount)
2667 {
2668         struct cifs_readdata *rdata = container_of(refcount,
2669                                         struct cifs_readdata, refcount);
2670         unsigned int i;
2671
2672         for (i = 0; i < rdata->nr_pages; i++) {
2673                 put_page(rdata->pages[i]);
2674                 rdata->pages[i] = NULL;
2675         }
2676         cifs_readdata_release(refcount);
2677 }
2678
2679 static int
2680 cifs_retry_async_readv(struct cifs_readdata *rdata)
2681 {
2682         int rc;
2683         struct TCP_Server_Info *server;
2684
2685         server = tlink_tcon(rdata->cfile->tlink)->ses->server;
2686
2687         do {
2688                 if (rdata->cfile->invalidHandle) {
2689                         rc = cifs_reopen_file(rdata->cfile, true);
2690                         if (rc != 0)
2691                                 continue;
2692                 }
2693                 rc = server->ops->async_readv(rdata);
2694         } while (rc == -EAGAIN);
2695
2696         return rc;
2697 }
2698
2699 /**
2700  * cifs_readdata_to_iov - copy data from pages in response to an iovec
2701  * @rdata:      the readdata response with list of pages holding data
2702  * @iov:        vector in which we should copy the data
2703  * @nr_segs:    number of segments in vector
2704  * @offset:     offset into file of the first iovec
2705  * @copied:     used to return the amount of data copied to the iov
2706  *
2707  * This function copies data from a list of pages in a readdata response into
2708  * an array of iovecs. It will first calculate where the data should go
2709  * based on the info in the readdata and then copy the data into that spot.
2710  */
2711 static ssize_t
2712 cifs_readdata_to_iov(struct cifs_readdata *rdata, const struct iovec *iov,
2713                         unsigned long nr_segs, loff_t offset, ssize_t *copied)
2714 {
2715         int rc = 0;
2716         struct iov_iter ii;
2717         size_t pos = rdata->offset - offset;
2718         ssize_t remaining = rdata->bytes;
2719         unsigned char *pdata;
2720         unsigned int i;
2721
2722         /* set up iov_iter and advance to the correct offset */
2723         iov_iter_init(&ii, iov, nr_segs, iov_length(iov, nr_segs), 0);
2724         iov_iter_advance(&ii, pos);
2725
2726         *copied = 0;
2727         for (i = 0; i < rdata->nr_pages; i++) {
2728                 ssize_t copy;
2729                 struct page *page = rdata->pages[i];
2730
2731                 /* copy a whole page or whatever's left */
2732                 copy = min_t(ssize_t, remaining, PAGE_SIZE);
2733
2734                 /* ...but limit it to whatever space is left in the iov */
2735                 copy = min_t(ssize_t, copy, iov_iter_count(&ii));
2736
2737                 /* go while there's data to be copied and no errors */
2738                 if (copy && !rc) {
2739                         pdata = kmap(page);
2740                         rc = memcpy_toiovecend(iov_iter_iovec(&ii), pdata,
2741                                                ii.iov_offset, (int)copy);
2742                         kunmap(page);
2743                         if (!rc) {
2744                                 *copied += copy;
2745                                 remaining -= copy;
2746                                 iov_iter_advance(&ii, copy);
2747                         }
2748                 }
2749         }
2750
2751         return rc;
2752 }
2753
2754 static void
2755 cifs_uncached_readv_complete(struct work_struct *work)
2756 {
2757         struct cifs_readdata *rdata = container_of(work,
2758                                                 struct cifs_readdata, work);
2759
2760         complete(&rdata->done);
2761         kref_put(&rdata->refcount, cifs_uncached_readdata_release);
2762 }
2763
2764 static int
2765 cifs_uncached_read_into_pages(struct TCP_Server_Info *server,
2766                         struct cifs_readdata *rdata, unsigned int len)
2767 {
2768         int total_read = 0, result = 0;
2769         unsigned int i;
2770         unsigned int nr_pages = rdata->nr_pages;
2771         struct kvec iov;
2772
2773         rdata->tailsz = PAGE_SIZE;
2774         for (i = 0; i < nr_pages; i++) {
2775                 struct page *page = rdata->pages[i];
2776
2777                 if (len >= PAGE_SIZE) {
2778                         /* enough data to fill the page */
2779                         iov.iov_base = kmap(page);
2780                         iov.iov_len = PAGE_SIZE;
2781                         cifs_dbg(FYI, "%u: iov_base=%p iov_len=%zu\n",
2782                                  i, iov.iov_base, iov.iov_len);
2783                         len -= PAGE_SIZE;
2784                 } else if (len > 0) {
2785                         /* enough for partial page, fill and zero the rest */
2786                         iov.iov_base = kmap(page);
2787                         iov.iov_len = len;
2788                         cifs_dbg(FYI, "%u: iov_base=%p iov_len=%zu\n",
2789                                  i, iov.iov_base, iov.iov_len);
2790                         memset(iov.iov_base + len, '\0', PAGE_SIZE - len);
2791                         rdata->tailsz = len;
2792                         len = 0;
2793                 } else {
2794                         /* no need to hold page hostage */
2795                         rdata->pages[i] = NULL;
2796                         rdata->nr_pages--;
2797                         put_page(page);
2798                         continue;
2799                 }
2800
2801                 result = cifs_readv_from_socket(server, &iov, 1, iov.iov_len);
2802                 kunmap(page);
2803                 if (result < 0)
2804                         break;
2805
2806                 total_read += result;
2807         }
2808
2809         return total_read > 0 ? total_read : result;
2810 }
2811
2812 static ssize_t
2813 cifs_iovec_read(struct file *file, const struct iovec *iov,
2814                  unsigned long nr_segs, loff_t *poffset)
2815 {
2816         ssize_t rc;
2817         size_t len, cur_len;
2818         ssize_t total_read = 0;
2819         loff_t offset = *poffset;
2820         unsigned int npages;
2821         struct cifs_sb_info *cifs_sb;
2822         struct cifs_tcon *tcon;
2823         struct cifsFileInfo *open_file;
2824         struct cifs_readdata *rdata, *tmp;
2825         struct list_head rdata_list;
2826         pid_t pid;
2827
2828         if (!nr_segs)
2829                 return 0;
2830
2831         len = iov_length(iov, nr_segs);
2832         if (!len)
2833                 return 0;
2834
2835         INIT_LIST_HEAD(&rdata_list);
2836         cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
2837         open_file = file->private_data;
2838         tcon = tlink_tcon(open_file->tlink);
2839
2840         if (!tcon->ses->server->ops->async_readv)
2841                 return -ENOSYS;
2842
2843         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
2844                 pid = open_file->pid;
2845         else
2846                 pid = current->tgid;
2847
2848         if ((file->f_flags & O_ACCMODE) == O_WRONLY)
2849                 cifs_dbg(FYI, "attempting read on write only file instance\n");
2850
2851         do {
2852                 cur_len = min_t(const size_t, len - total_read, cifs_sb->rsize);
2853                 npages = DIV_ROUND_UP(cur_len, PAGE_SIZE);
2854
2855                 /* allocate a readdata struct */
2856                 rdata = cifs_readdata_alloc(npages,
2857                                             cifs_uncached_readv_complete);
2858                 if (!rdata) {
2859                         rc = -ENOMEM;
2860                         goto error;
2861                 }
2862
2863                 rc = cifs_read_allocate_pages(rdata, npages);
2864                 if (rc)
2865                         goto error;
2866
2867                 rdata->cfile = cifsFileInfo_get(open_file);
2868                 rdata->nr_pages = npages;
2869                 rdata->offset = offset;
2870                 rdata->bytes = cur_len;
2871                 rdata->pid = pid;
2872                 rdata->pagesz = PAGE_SIZE;
2873                 rdata->read_into_pages = cifs_uncached_read_into_pages;
2874
2875                 rc = cifs_retry_async_readv(rdata);
2876 error:
2877                 if (rc) {
2878                         kref_put(&rdata->refcount,
2879                                  cifs_uncached_readdata_release);
2880                         break;
2881                 }
2882
2883                 list_add_tail(&rdata->list, &rdata_list);
2884                 offset += cur_len;
2885                 len -= cur_len;
2886         } while (len > 0);
2887
2888         /* if at least one read request send succeeded, then reset rc */
2889         if (!list_empty(&rdata_list))
2890                 rc = 0;
2891
2892         /* the loop below should proceed in the order of increasing offsets */
2893 restart_loop:
2894         list_for_each_entry_safe(rdata, tmp, &rdata_list, list) {
2895                 if (!rc) {
2896                         ssize_t copied;
2897
2898                         /* FIXME: freezable sleep too? */
2899                         rc = wait_for_completion_killable(&rdata->done);
2900                         if (rc)
2901                                 rc = -EINTR;
2902                         else if (rdata->result)
2903                                 rc = rdata->result;
2904                         else {
2905                                 rc = cifs_readdata_to_iov(rdata, iov,
2906                                                         nr_segs, *poffset,
2907                                                         &copied);
2908                                 total_read += copied;
2909                         }
2910
2911                         /* resend call if it's a retryable error */
2912                         if (rc == -EAGAIN) {
2913                                 rc = cifs_retry_async_readv(rdata);
2914                                 goto restart_loop;
2915                         }
2916                 }
2917                 list_del_init(&rdata->list);
2918                 kref_put(&rdata->refcount, cifs_uncached_readdata_release);
2919         }
2920
2921         cifs_stats_bytes_read(tcon, total_read);
2922         *poffset += total_read;
2923
2924         /* mask nodata case */
2925         if (rc == -ENODATA)
2926                 rc = 0;
2927
2928         return total_read ? total_read : rc;
2929 }
2930
2931 ssize_t cifs_user_readv(struct kiocb *iocb, const struct iovec *iov,
2932                                unsigned long nr_segs, loff_t pos)
2933 {
2934         ssize_t read;
2935
2936         read = cifs_iovec_read(iocb->ki_filp, iov, nr_segs, &pos);
2937         if (read > 0)
2938                 iocb->ki_pos = pos;
2939
2940         return read;
2941 }
2942
2943 ssize_t
2944 cifs_strict_readv(struct kiocb *iocb, const struct iovec *iov,
2945                   unsigned long nr_segs, loff_t pos)
2946 {
2947         struct inode *inode = file_inode(iocb->ki_filp);
2948         struct cifsInodeInfo *cinode = CIFS_I(inode);
2949         struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
2950         struct cifsFileInfo *cfile = (struct cifsFileInfo *)
2951                                                 iocb->ki_filp->private_data;
2952         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
2953         int rc = -EACCES;
2954
2955         /*
2956          * In strict cache mode we need to read from the server all the time
2957          * if we don't have level II oplock because the server can delay mtime
2958          * change - so we can't make a decision about inode invalidating.
2959          * And we can also fail with pagereading if there are mandatory locks
2960          * on pages affected by this read but not on the region from pos to
2961          * pos+len-1.
2962          */
2963         if (!CIFS_CACHE_READ(cinode))
2964                 return cifs_user_readv(iocb, iov, nr_segs, pos);
2965
2966         if (cap_unix(tcon->ses) &&
2967             (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
2968             ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
2969                 return generic_file_aio_read(iocb, iov, nr_segs, pos);
2970
2971         /*
2972          * We need to hold the sem to be sure nobody modifies lock list
2973          * with a brlock that prevents reading.
2974          */
2975         down_read(&cinode->lock_sem);
2976         if (!cifs_find_lock_conflict(cfile, pos, iov_length(iov, nr_segs),
2977                                      tcon->ses->server->vals->shared_lock_type,
2978                                      NULL, CIFS_READ_OP))
2979                 rc = generic_file_aio_read(iocb, iov, nr_segs, pos);
2980         up_read(&cinode->lock_sem);
2981         return rc;
2982 }
2983
2984 static ssize_t
2985 cifs_read(struct file *file, char *read_data, size_t read_size, loff_t *offset)
2986 {
2987         int rc = -EACCES;
2988         unsigned int bytes_read = 0;
2989         unsigned int total_read;
2990         unsigned int current_read_size;
2991         unsigned int rsize;
2992         struct cifs_sb_info *cifs_sb;
2993         struct cifs_tcon *tcon;
2994         struct TCP_Server_Info *server;
2995         unsigned int xid;
2996         char *cur_offset;
2997         struct cifsFileInfo *open_file;
2998         struct cifs_io_parms io_parms;
2999         int buf_type = CIFS_NO_BUFFER;
3000         __u32 pid;
3001
3002         xid = get_xid();
3003         cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
3004
3005         /* FIXME: set up handlers for larger reads and/or convert to async */
3006         rsize = min_t(unsigned int, cifs_sb->rsize, CIFSMaxBufSize);
3007
3008         if (file->private_data == NULL) {
3009                 rc = -EBADF;
3010                 free_xid(xid);
3011                 return rc;
3012         }
3013         open_file = file->private_data;
3014         tcon = tlink_tcon(open_file->tlink);
3015         server = tcon->ses->server;
3016
3017         if (!server->ops->sync_read) {
3018                 free_xid(xid);
3019                 return -ENOSYS;
3020         }
3021
3022         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
3023                 pid = open_file->pid;
3024         else
3025                 pid = current->tgid;
3026
3027         if ((file->f_flags & O_ACCMODE) == O_WRONLY)
3028                 cifs_dbg(FYI, "attempting read on write only file instance\n");
3029
3030         for (total_read = 0, cur_offset = read_data; read_size > total_read;
3031              total_read += bytes_read, cur_offset += bytes_read) {
3032                 current_read_size = min_t(uint, read_size - total_read, rsize);
3033                 /*
3034                  * For windows me and 9x we do not want to request more than it
3035                  * negotiated since it will refuse the read then.
3036                  */
3037                 if ((tcon->ses) && !(tcon->ses->capabilities &
3038                                 tcon->ses->server->vals->cap_large_files)) {
3039                         current_read_size = min_t(uint, current_read_size,
3040                                         CIFSMaxBufSize);
3041                 }
3042                 rc = -EAGAIN;
3043                 while (rc == -EAGAIN) {
3044                         if (open_file->invalidHandle) {
3045                                 rc = cifs_reopen_file(open_file, true);
3046                                 if (rc != 0)
3047                                         break;
3048                         }
3049                         io_parms.pid = pid;
3050                         io_parms.tcon = tcon;
3051                         io_parms.offset = *offset;
3052                         io_parms.length = current_read_size;
3053                         rc = server->ops->sync_read(xid, open_file, &io_parms,
3054                                                     &bytes_read, &cur_offset,
3055                                                     &buf_type);
3056                 }
3057                 if (rc || (bytes_read == 0)) {
3058                         if (total_read) {
3059                                 break;
3060                         } else {
3061                                 free_xid(xid);
3062                                 return rc;
3063                         }
3064                 } else {
3065                         cifs_stats_bytes_read(tcon, total_read);
3066                         *offset += bytes_read;
3067                 }
3068         }
3069         free_xid(xid);
3070         return total_read;
3071 }
3072
3073 /*
3074  * If the page is mmap'ed into a process' page tables, then we need to make
3075  * sure that it doesn't change while being written back.
3076  */
3077 static int
3078 cifs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
3079 {
3080         struct page *page = vmf->page;
3081
3082         lock_page(page);
3083         return VM_FAULT_LOCKED;
3084 }
3085
3086 static struct vm_operations_struct cifs_file_vm_ops = {
3087         .fault = filemap_fault,
3088         .page_mkwrite = cifs_page_mkwrite,
3089         .remap_pages = generic_file_remap_pages,
3090 };
3091
3092 int cifs_file_strict_mmap(struct file *file, struct vm_area_struct *vma)
3093 {
3094         int rc, xid;
3095         struct inode *inode = file_inode(file);
3096
3097         xid = get_xid();
3098
3099         if (!CIFS_CACHE_READ(CIFS_I(inode))) {
3100                 rc = cifs_invalidate_mapping(inode);
3101                 if (rc)
3102                         return rc;
3103         }
3104
3105         rc = generic_file_mmap(file, vma);
3106         if (rc == 0)
3107                 vma->vm_ops = &cifs_file_vm_ops;
3108         free_xid(xid);
3109         return rc;
3110 }
3111
3112 int cifs_file_mmap(struct file *file, struct vm_area_struct *vma)
3113 {
3114         int rc, xid;
3115
3116         xid = get_xid();
3117         rc = cifs_revalidate_file(file);
3118         if (rc) {
3119                 cifs_dbg(FYI, "Validation prior to mmap failed, error=%d\n",
3120                          rc);
3121                 free_xid(xid);
3122                 return rc;
3123         }
3124         rc = generic_file_mmap(file, vma);
3125         if (rc == 0)
3126                 vma->vm_ops = &cifs_file_vm_ops;
3127         free_xid(xid);
3128         return rc;
3129 }
3130
3131 static void
3132 cifs_readv_complete(struct work_struct *work)
3133 {
3134         unsigned int i;
3135         struct cifs_readdata *rdata = container_of(work,
3136                                                 struct cifs_readdata, work);
3137
3138         for (i = 0; i < rdata->nr_pages; i++) {
3139                 struct page *page = rdata->pages[i];
3140
3141                 lru_cache_add_file(page);
3142
3143                 if (rdata->result == 0) {
3144                         flush_dcache_page(page);
3145                         SetPageUptodate(page);
3146                 }
3147
3148                 unlock_page(page);
3149
3150                 if (rdata->result == 0)
3151                         cifs_readpage_to_fscache(rdata->mapping->host, page);
3152
3153                 page_cache_release(page);
3154                 rdata->pages[i] = NULL;
3155         }
3156         kref_put(&rdata->refcount, cifs_readdata_release);
3157 }
3158
3159 static int
3160 cifs_readpages_read_into_pages(struct TCP_Server_Info *server,
3161                         struct cifs_readdata *rdata, unsigned int len)
3162 {
3163         int total_read = 0, result = 0;
3164         unsigned int i;
3165         u64 eof;
3166         pgoff_t eof_index;
3167         unsigned int nr_pages = rdata->nr_pages;
3168         struct kvec iov;
3169
3170         /* determine the eof that the server (probably) has */
3171         eof = CIFS_I(rdata->mapping->host)->server_eof;
3172         eof_index = eof ? (eof - 1) >> PAGE_CACHE_SHIFT : 0;
3173         cifs_dbg(FYI, "eof=%llu eof_index=%lu\n", eof, eof_index);
3174
3175         rdata->tailsz = PAGE_CACHE_SIZE;
3176         for (i = 0; i < nr_pages; i++) {
3177                 struct page *page = rdata->pages[i];
3178
3179                 if (len >= PAGE_CACHE_SIZE) {
3180                         /* enough data to fill the page */
3181                         iov.iov_base = kmap(page);
3182                         iov.iov_len = PAGE_CACHE_SIZE;
3183                         cifs_dbg(FYI, "%u: idx=%lu iov_base=%p iov_len=%zu\n",
3184                                  i, page->index, iov.iov_base, iov.iov_len);
3185                         len -= PAGE_CACHE_SIZE;
3186                 } else if (len > 0) {
3187                         /* enough for partial page, fill and zero the rest */
3188                         iov.iov_base = kmap(page);
3189                         iov.iov_len = len;
3190                         cifs_dbg(FYI, "%u: idx=%lu iov_base=%p iov_len=%zu\n",
3191                                  i, page->index, iov.iov_base, iov.iov_len);
3192                         memset(iov.iov_base + len,
3193                                 '\0', PAGE_CACHE_SIZE - len);
3194                         rdata->tailsz = len;
3195                         len = 0;
3196                 } else if (page->index > eof_index) {
3197                         /*
3198                          * The VFS will not try to do readahead past the
3199                          * i_size, but it's possible that we have outstanding
3200                          * writes with gaps in the middle and the i_size hasn't
3201                          * caught up yet. Populate those with zeroed out pages
3202                          * to prevent the VFS from repeatedly attempting to
3203                          * fill them until the writes are flushed.
3204                          */
3205                         zero_user(page, 0, PAGE_CACHE_SIZE);
3206                         lru_cache_add_file(page);
3207                         flush_dcache_page(page);
3208                         SetPageUptodate(page);
3209                         unlock_page(page);
3210                         page_cache_release(page);
3211                         rdata->pages[i] = NULL;
3212                         rdata->nr_pages--;
3213                         continue;
3214                 } else {
3215                         /* no need to hold page hostage */
3216                         lru_cache_add_file(page);
3217                         unlock_page(page);
3218                         page_cache_release(page);
3219                         rdata->pages[i] = NULL;
3220                         rdata->nr_pages--;
3221                         continue;
3222                 }
3223
3224                 result = cifs_readv_from_socket(server, &iov, 1, iov.iov_len);
3225                 kunmap(page);
3226                 if (result < 0)
3227                         break;
3228
3229                 total_read += result;
3230         }
3231
3232         return total_read > 0 ? total_read : result;
3233 }
3234
3235 static int cifs_readpages(struct file *file, struct address_space *mapping,
3236         struct list_head *page_list, unsigned num_pages)
3237 {
3238         int rc;
3239         struct list_head tmplist;
3240         struct cifsFileInfo *open_file = file->private_data;
3241         struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
3242         unsigned int rsize = cifs_sb->rsize;
3243         pid_t pid;
3244
3245         /*
3246          * Give up immediately if rsize is too small to read an entire page.
3247          * The VFS will fall back to readpage. We should never reach this
3248          * point however since we set ra_pages to 0 when the rsize is smaller
3249          * than a cache page.
3250          */
3251         if (unlikely(rsize < PAGE_CACHE_SIZE))
3252                 return 0;
3253
3254         /*
3255          * Reads as many pages as possible from fscache. Returns -ENOBUFS
3256          * immediately if the cookie is negative
3257          *
3258          * After this point, every page in the list might have PG_fscache set,
3259          * so we will need to clean that up off of every page we don't use.
3260          */
3261         rc = cifs_readpages_from_fscache(mapping->host, mapping, page_list,
3262                                          &num_pages);
3263         if (rc == 0)
3264                 return rc;
3265
3266         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
3267                 pid = open_file->pid;
3268         else
3269                 pid = current->tgid;
3270
3271         rc = 0;
3272         INIT_LIST_HEAD(&tmplist);
3273
3274         cifs_dbg(FYI, "%s: file=%p mapping=%p num_pages=%u\n",
3275                  __func__, file, mapping, num_pages);
3276
3277         /*
3278          * Start with the page at end of list and move it to private
3279          * list. Do the same with any following pages until we hit
3280          * the rsize limit, hit an index discontinuity, or run out of
3281          * pages. Issue the async read and then start the loop again
3282          * until the list is empty.
3283          *
3284          * Note that list order is important. The page_list is in
3285          * the order of declining indexes. When we put the pages in
3286          * the rdata->pages, then we want them in increasing order.
3287          */
3288         while (!list_empty(page_list)) {
3289                 unsigned int i;
3290                 unsigned int bytes = PAGE_CACHE_SIZE;
3291                 unsigned int expected_index;
3292                 unsigned int nr_pages = 1;
3293                 loff_t offset;
3294                 struct page *page, *tpage;
3295                 struct cifs_readdata *rdata;
3296
3297                 page = list_entry(page_list->prev, struct page, lru);
3298
3299                 /*
3300                  * Lock the page and put it in the cache. Since no one else
3301                  * should have access to this page, we're safe to simply set
3302                  * PG_locked without checking it first.
3303                  */
3304                 __set_page_locked(page);
3305                 rc = add_to_page_cache_locked(page, mapping,
3306                                               page->index, GFP_KERNEL);
3307
3308                 /* give up if we can't stick it in the cache */
3309                 if (rc) {
3310                         __clear_page_locked(page);
3311                         break;
3312                 }
3313
3314                 /* move first page to the tmplist */
3315                 offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
3316                 list_move_tail(&page->lru, &tmplist);
3317
3318                 /* now try and add more pages onto the request */
3319                 expected_index = page->index + 1;
3320                 list_for_each_entry_safe_reverse(page, tpage, page_list, lru) {
3321                         /* discontinuity ? */
3322                         if (page->index != expected_index)
3323                                 break;
3324
3325                         /* would this page push the read over the rsize? */
3326                         if (bytes + PAGE_CACHE_SIZE > rsize)
3327                                 break;
3328
3329                         __set_page_locked(page);
3330                         if (add_to_page_cache_locked(page, mapping,
3331                                                 page->index, GFP_KERNEL)) {
3332                                 __clear_page_locked(page);
3333                                 break;
3334                         }
3335                         list_move_tail(&page->lru, &tmplist);
3336                         bytes += PAGE_CACHE_SIZE;
3337                         expected_index++;
3338                         nr_pages++;
3339                 }
3340
3341                 rdata = cifs_readdata_alloc(nr_pages, cifs_readv_complete);
3342                 if (!rdata) {
3343                         /* best to give up if we're out of mem */
3344                         list_for_each_entry_safe(page, tpage, &tmplist, lru) {
3345                                 list_del(&page->lru);
3346                                 lru_cache_add_file(page);
3347                                 unlock_page(page);
3348                                 page_cache_release(page);
3349                         }
3350                         rc = -ENOMEM;
3351                         break;
3352                 }
3353
3354                 rdata->cfile = cifsFileInfo_get(open_file);
3355                 rdata->mapping = mapping;
3356                 rdata->offset = offset;
3357                 rdata->bytes = bytes;
3358                 rdata->pid = pid;
3359                 rdata->pagesz = PAGE_CACHE_SIZE;
3360                 rdata->read_into_pages = cifs_readpages_read_into_pages;
3361
3362                 list_for_each_entry_safe(page, tpage, &tmplist, lru) {
3363                         list_del(&page->lru);
3364                         rdata->pages[rdata->nr_pages++] = page;
3365                 }
3366
3367                 rc = cifs_retry_async_readv(rdata);
3368                 if (rc != 0) {
3369                         for (i = 0; i < rdata->nr_pages; i++) {
3370                                 page = rdata->pages[i];
3371                                 lru_cache_add_file(page);
3372                                 unlock_page(page);
3373                                 page_cache_release(page);
3374                         }
3375                         kref_put(&rdata->refcount, cifs_readdata_release);
3376                         break;
3377                 }
3378
3379                 kref_put(&rdata->refcount, cifs_readdata_release);
3380         }
3381
3382         /* Any pages that have been shown to fscache but didn't get added to
3383          * the pagecache must be uncached before they get returned to the
3384          * allocator.
3385          */
3386         cifs_fscache_readpages_cancel(mapping->host, page_list);
3387         return rc;
3388 }
3389
3390 /*
3391  * cifs_readpage_worker must be called with the page pinned
3392  */
3393 static int cifs_readpage_worker(struct file *file, struct page *page,
3394         loff_t *poffset)
3395 {
3396         char *read_data;
3397         int rc;
3398
3399         /* Is the page cached? */
3400         rc = cifs_readpage_from_fscache(file_inode(file), page);
3401         if (rc == 0)
3402                 goto read_complete;
3403
3404         read_data = kmap(page);
3405         /* for reads over a certain size could initiate async read ahead */
3406
3407         rc = cifs_read(file, read_data, PAGE_CACHE_SIZE, poffset);
3408
3409         if (rc < 0)
3410                 goto io_error;
3411         else
3412                 cifs_dbg(FYI, "Bytes read %d\n", rc);
3413
3414         file_inode(file)->i_atime =
3415                 current_fs_time(file_inode(file)->i_sb);
3416
3417         if (PAGE_CACHE_SIZE > rc)
3418                 memset(read_data + rc, 0, PAGE_CACHE_SIZE - rc);
3419
3420         flush_dcache_page(page);
3421         SetPageUptodate(page);
3422
3423         /* send this page to the cache */
3424         cifs_readpage_to_fscache(file_inode(file), page);
3425
3426         rc = 0;
3427
3428 io_error:
3429         kunmap(page);
3430         unlock_page(page);
3431
3432 read_complete:
3433         return rc;
3434 }
3435
3436 static int cifs_readpage(struct file *file, struct page *page)
3437 {
3438         loff_t offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
3439         int rc = -EACCES;
3440         unsigned int xid;
3441
3442         xid = get_xid();
3443
3444         if (file->private_data == NULL) {
3445                 rc = -EBADF;
3446                 free_xid(xid);
3447                 return rc;
3448         }
3449
3450         cifs_dbg(FYI, "readpage %p at offset %d 0x%x\n",
3451                  page, (int)offset, (int)offset);
3452
3453         rc = cifs_readpage_worker(file, page, &offset);
3454
3455         free_xid(xid);
3456         return rc;
3457 }
3458
3459 static int is_inode_writable(struct cifsInodeInfo *cifs_inode)
3460 {
3461         struct cifsFileInfo *open_file;
3462
3463         spin_lock(&cifs_file_list_lock);
3464         list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
3465                 if (OPEN_FMODE(open_file->f_flags) & FMODE_WRITE) {
3466                         spin_unlock(&cifs_file_list_lock);
3467                         return 1;
3468                 }
3469         }
3470         spin_unlock(&cifs_file_list_lock);
3471         return 0;
3472 }
3473
3474 /* We do not want to update the file size from server for inodes
3475    open for write - to avoid races with writepage extending
3476    the file - in the future we could consider allowing
3477    refreshing the inode only on increases in the file size
3478    but this is tricky to do without racing with writebehind
3479    page caching in the current Linux kernel design */
3480 bool is_size_safe_to_change(struct cifsInodeInfo *cifsInode, __u64 end_of_file)
3481 {
3482         if (!cifsInode)
3483                 return true;
3484
3485         if (is_inode_writable(cifsInode)) {
3486                 /* This inode is open for write at least once */
3487                 struct cifs_sb_info *cifs_sb;
3488
3489                 cifs_sb = CIFS_SB(cifsInode->vfs_inode.i_sb);
3490                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DIRECT_IO) {
3491                         /* since no page cache to corrupt on directio
3492                         we can change size safely */
3493                         return true;
3494                 }
3495
3496                 if (i_size_read(&cifsInode->vfs_inode) < end_of_file)
3497                         return true;
3498
3499                 return false;
3500         } else
3501                 return true;
3502 }
3503
3504 static int cifs_write_begin(struct file *file, struct address_space *mapping,
3505                         loff_t pos, unsigned len, unsigned flags,
3506                         struct page **pagep, void **fsdata)
3507 {
3508         int oncethru = 0;
3509         pgoff_t index = pos >> PAGE_CACHE_SHIFT;
3510         loff_t offset = pos & (PAGE_CACHE_SIZE - 1);
3511         loff_t page_start = pos & PAGE_MASK;
3512         loff_t i_size;
3513         struct page *page;
3514         int rc = 0;
3515
3516         cifs_dbg(FYI, "write_begin from %lld len %d\n", (long long)pos, len);
3517
3518 start:
3519         page = grab_cache_page_write_begin(mapping, index, flags);
3520         if (!page) {
3521                 rc = -ENOMEM;
3522                 goto out;
3523         }
3524
3525         if (PageUptodate(page))
3526                 goto out;
3527
3528         /*
3529          * If we write a full page it will be up to date, no need to read from
3530          * the server. If the write is short, we'll end up doing a sync write
3531          * instead.
3532          */
3533         if (len == PAGE_CACHE_SIZE)
3534                 goto out;
3535
3536         /*
3537          * optimize away the read when we have an oplock, and we're not
3538          * expecting to use any of the data we'd be reading in. That
3539          * is, when the page lies beyond the EOF, or straddles the EOF
3540          * and the write will cover all of the existing data.
3541          */
3542         if (CIFS_CACHE_READ(CIFS_I(mapping->host))) {
3543                 i_size = i_size_read(mapping->host);
3544                 if (page_start >= i_size ||
3545                     (offset == 0 && (pos + len) >= i_size)) {
3546                         zero_user_segments(page, 0, offset,
3547                                            offset + len,
3548                                            PAGE_CACHE_SIZE);
3549                         /*
3550                          * PageChecked means that the parts of the page
3551                          * to which we're not writing are considered up
3552                          * to date. Once the data is copied to the
3553                          * page, it can be set uptodate.
3554                          */
3555                         SetPageChecked(page);
3556                         goto out;
3557                 }
3558         }
3559
3560         if ((file->f_flags & O_ACCMODE) != O_WRONLY && !oncethru) {
3561                 /*
3562                  * might as well read a page, it is fast enough. If we get
3563                  * an error, we don't need to return it. cifs_write_end will
3564                  * do a sync write instead since PG_uptodate isn't set.
3565                  */
3566                 cifs_readpage_worker(file, page, &page_start);
3567                 page_cache_release(page);
3568                 oncethru = 1;
3569                 goto start;
3570         } else {
3571                 /* we could try using another file handle if there is one -
3572                    but how would we lock it to prevent close of that handle
3573                    racing with this read? In any case
3574                    this will be written out by write_end so is fine */
3575         }
3576 out:
3577         *pagep = page;
3578         return rc;
3579 }
3580
3581 static int cifs_release_page(struct page *page, gfp_t gfp)
3582 {
3583         if (PagePrivate(page))
3584                 return 0;
3585
3586         return cifs_fscache_release_page(page, gfp);
3587 }
3588
3589 static void cifs_invalidate_page(struct page *page, unsigned int offset,
3590                                  unsigned int length)
3591 {
3592         struct cifsInodeInfo *cifsi = CIFS_I(page->mapping->host);
3593
3594         if (offset == 0 && length == PAGE_CACHE_SIZE)
3595                 cifs_fscache_invalidate_page(page, &cifsi->vfs_inode);
3596 }
3597
3598 static int cifs_launder_page(struct page *page)
3599 {
3600         int rc = 0;
3601         loff_t range_start = page_offset(page);
3602         loff_t range_end = range_start + (loff_t)(PAGE_CACHE_SIZE - 1);
3603         struct writeback_control wbc = {
3604                 .sync_mode = WB_SYNC_ALL,
3605                 .nr_to_write = 0,
3606                 .range_start = range_start,
3607                 .range_end = range_end,
3608         };
3609
3610         cifs_dbg(FYI, "Launder page: %p\n", page);
3611
3612         if (clear_page_dirty_for_io(page))
3613                 rc = cifs_writepage_locked(page, &wbc);
3614
3615         cifs_fscache_invalidate_page(page, page->mapping->host);
3616         return rc;
3617 }
3618
3619 void cifs_oplock_break(struct work_struct *work)
3620 {
3621         struct cifsFileInfo *cfile = container_of(work, struct cifsFileInfo,
3622                                                   oplock_break);
3623         struct inode *inode = cfile->dentry->d_inode;
3624         struct cifsInodeInfo *cinode = CIFS_I(inode);
3625         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
3626         int rc = 0;
3627
3628         if (!CIFS_CACHE_WRITE(cinode) && CIFS_CACHE_READ(cinode) &&
3629                                                 cifs_has_mand_locks(cinode)) {
3630                 cifs_dbg(FYI, "Reset oplock to None for inode=%p due to mand locks\n",
3631                          inode);
3632                 cinode->oplock = 0;
3633         }
3634
3635         if (inode && S_ISREG(inode->i_mode)) {
3636                 if (CIFS_CACHE_READ(cinode))
3637                         break_lease(inode, O_RDONLY);
3638                 else
3639                         break_lease(inode, O_WRONLY);
3640                 rc = filemap_fdatawrite(inode->i_mapping);
3641                 if (!CIFS_CACHE_READ(cinode)) {
3642                         rc = filemap_fdatawait(inode->i_mapping);
3643                         mapping_set_error(inode->i_mapping, rc);
3644                         cifs_invalidate_mapping(inode);
3645                 }
3646                 cifs_dbg(FYI, "Oplock flush inode %p rc %d\n", inode, rc);
3647         }
3648
3649         rc = cifs_push_locks(cfile);
3650         if (rc)
3651                 cifs_dbg(VFS, "Push locks rc = %d\n", rc);
3652
3653         /*
3654          * releasing stale oplock after recent reconnect of smb session using
3655          * a now incorrect file handle is not a data integrity issue but do
3656          * not bother sending an oplock release if session to server still is
3657          * disconnected since oplock already released by the server
3658          */
3659         if (!cfile->oplock_break_cancelled) {
3660                 rc = tcon->ses->server->ops->oplock_response(tcon, &cfile->fid,
3661                                                              cinode);
3662                 cifs_dbg(FYI, "Oplock release rc = %d\n", rc);
3663         }
3664 }
3665
3666 const struct address_space_operations cifs_addr_ops = {
3667         .readpage = cifs_readpage,
3668         .readpages = cifs_readpages,
3669         .writepage = cifs_writepage,
3670         .writepages = cifs_writepages,
3671         .write_begin = cifs_write_begin,
3672         .write_end = cifs_write_end,
3673         .set_page_dirty = __set_page_dirty_nobuffers,
3674         .releasepage = cifs_release_page,
3675         .invalidatepage = cifs_invalidate_page,
3676         .launder_page = cifs_launder_page,
3677 };
3678
3679 /*
3680  * cifs_readpages requires the server to support a buffer large enough to
3681  * contain the header plus one complete page of data.  Otherwise, we need
3682  * to leave cifs_readpages out of the address space operations.
3683  */
3684 const struct address_space_operations cifs_addr_ops_smallbuf = {
3685         .readpage = cifs_readpage,
3686         .writepage = cifs_writepage,
3687         .writepages = cifs_writepages,
3688         .write_begin = cifs_write_begin,
3689         .write_end = cifs_write_end,
3690         .set_page_dirty = __set_page_dirty_nobuffers,
3691         .releasepage = cifs_release_page,
3692         .invalidatepage = cifs_invalidate_page,
3693         .launder_page = cifs_launder_page,
3694 };