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 ([email protected])
   8  *              Jeremy Allison ([email protected])
   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 <linux/mm.h>
  37 #include <asm/div64.h>
  38 #include "cifsfs.h"
  39 #include "cifspdu.h"
  40 #include "cifsglob.h"
  41 #include "cifsproto.h"
  42 #include "cifs_unicode.h"
  43 #include "cifs_debug.h"
  44 #include "cifs_fs_sb.h"
  45 #include "fscache.h"
  46 #include "smbdirect.h"
  47
  48 static inline int cifs_convert_flags(unsigned int flags)
  49 {
  50         if ((flags & O_ACCMODE) == O_RDONLY)
  51                 return GENERIC_READ;
  52         else if ((flags & O_ACCMODE) == O_WRONLY)
  53                 return GENERIC_WRITE;
  54         else if ((flags & O_ACCMODE) == O_RDWR) {
  55                 /* GENERIC_ALL is too much permission to request
  56                    can cause unnecessary access denied on create */
  57                 /* return GENERIC_ALL; */
  58                 return (GENERIC_READ | GENERIC_WRITE);
  59         }
  60
  61         return (READ_CONTROL | FILE_WRITE_ATTRIBUTES | FILE_READ_ATTRIBUTES |
  62                 FILE_WRITE_EA | FILE_APPEND_DATA | FILE_WRITE_DATA |
  63                 FILE_READ_DATA);
  64 }
  65
  66 static u32 cifs_posix_convert_flags(unsigned int flags)
  67 {
  68         u32 posix_flags = 0;
  69
  70         if ((flags & O_ACCMODE) == O_RDONLY)
  71                 posix_flags = SMB_O_RDONLY;
  72         else if ((flags & O_ACCMODE) == O_WRONLY)
  73                 posix_flags = SMB_O_WRONLY;
  74         else if ((flags & O_ACCMODE) == O_RDWR)
  75                 posix_flags = SMB_O_RDWR;
  76
  77         if (flags & O_CREAT) {
  78                 posix_flags |= SMB_O_CREAT;
  79                 if (flags & O_EXCL)
  80                         posix_flags |= SMB_O_EXCL;
  81         } else if (flags & O_EXCL)
  82                 cifs_dbg(FYI, "Application %s pid %d has incorrectly set O_EXCL flag but not O_CREAT on file open. Ignoring O_EXCL\n",
  83                          current->comm, current->tgid);
  84
  85         if (flags & O_TRUNC)
  86                 posix_flags |= SMB_O_TRUNC;
  87         /* be safe and imply O_SYNC for O_DSYNC */
  88         if (flags & O_DSYNC)
  89                 posix_flags |= SMB_O_SYNC;
  90         if (flags & O_DIRECTORY)
  91                 posix_flags |= SMB_O_DIRECTORY;
  92         if (flags & O_NOFOLLOW)
  93                 posix_flags |= SMB_O_NOFOLLOW;
  94         if (flags & O_DIRECT)
  95                 posix_flags |= SMB_O_DIRECT;
  96
  97         return posix_flags;
  98 }
  99
 100 static inline int cifs_get_disposition(unsigned int flags)
 101 {
 102         if ((flags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
 103                 return FILE_CREATE;
 104         else if ((flags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
 105                 return FILE_OVERWRITE_IF;
 106         else if ((flags & O_CREAT) == O_CREAT)
 107                 return FILE_OPEN_IF;
 108         else if ((flags & O_TRUNC) == O_TRUNC)
 109                 return FILE_OVERWRITE;
 110         else
 111                 return FILE_OPEN;
 112 }
 113
 114 int cifs_posix_open(char *full_path, struct inode **pinode,
 115                         struct super_block *sb, int mode, unsigned int f_flags,
 116                         __u32 *poplock, __u16 *pnetfid, unsigned int xid)
 117 {
 118         int rc;
 119         FILE_UNIX_BASIC_INFO *presp_data;
 120         __u32 posix_flags = 0;
 121         struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
 122         struct cifs_fattr fattr;
 123         struct tcon_link *tlink;
 124         struct cifs_tcon *tcon;
 125
 126         cifs_dbg(FYI, "posix open %s\n", full_path);
 127
 128         presp_data = kzalloc(sizeof(FILE_UNIX_BASIC_INFO), GFP_KERNEL);
 129         if (presp_data == NULL)
 130                 return -ENOMEM;
 131
 132         tlink = cifs_sb_tlink(cifs_sb);
 133         if (IS_ERR(tlink)) {
 134                 rc = PTR_ERR(tlink);
 135                 goto posix_open_ret;
 136         }
 137
 138         tcon = tlink_tcon(tlink);
 139         mode &= ~current_umask();
 140
 141         posix_flags = cifs_posix_convert_flags(f_flags);
 142         rc = CIFSPOSIXCreate(xid, tcon, posix_flags, mode, pnetfid, presp_data,
 143                              poplock, full_path, cifs_sb->local_nls,
 144                              cifs_remap(cifs_sb));
 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         /* O_SYNC also has bit for O_DSYNC so following check picks up either */
 229         if (f_flags & O_SYNC)
 230                 create_options |= CREATE_WRITE_THROUGH;
 231
 232         if (f_flags & O_DIRECT)
 233                 create_options |= CREATE_NO_BUFFER;
 234
 235         oparms.tcon = tcon;
 236         oparms.cifs_sb = cifs_sb;
 237         oparms.desired_access = desired_access;
 238         oparms.create_options = create_options;
 239         oparms.disposition = disposition;
 240         oparms.path = full_path;
 241         oparms.fid = fid;
 242         oparms.reconnect = false;
 243
 244         rc = server->ops->open(xid, &oparms, oplock, buf);
 245
 246         if (rc)
 247                 goto out;
 248
 249         if (tcon->unix_ext)
 250                 rc = cifs_get_inode_info_unix(&inode, full_path, inode->i_sb,
 251                                               xid);
 252         else
 253                 rc = cifs_get_inode_info(&inode, full_path, buf, inode->i_sb,
 254                                          xid, fid);
 255
 256 out:
 257         kfree(buf);
 258         return rc;
 259 }
 260
 261 static bool
 262 cifs_has_mand_locks(struct cifsInodeInfo *cinode)
 263 {
 264         struct cifs_fid_locks *cur;
 265         bool has_locks = false;
 266
 267         down_read(&cinode->lock_sem);
 268         list_for_each_entry(cur, &cinode->llist, llist) {
 269                 if (!list_empty(&cur->locks)) {
 270                         has_locks = true;
 271                         break;
 272                 }
 273         }
 274         up_read(&cinode->lock_sem);
 275         return has_locks;
 276 }
 277
 278 struct cifsFileInfo *
 279 cifs_new_fileinfo(struct cifs_fid *fid, struct file *file,
 280                   struct tcon_link *tlink, __u32 oplock)
 281 {
 282         struct dentry *dentry = file_dentry(file);
 283         struct inode *inode = d_inode(dentry);
 284         struct cifsInodeInfo *cinode = CIFS_I(inode);
 285         struct cifsFileInfo *cfile;
 286         struct cifs_fid_locks *fdlocks;
 287         struct cifs_tcon *tcon = tlink_tcon(tlink);
 288         struct TCP_Server_Info *server = tcon->ses->server;
 289
 290         cfile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
 291         if (cfile == NULL)
 292                 return cfile;
 293
 294         fdlocks = kzalloc(sizeof(struct cifs_fid_locks), GFP_KERNEL);
 295         if (!fdlocks) {
 296                 kfree(cfile);
 297                 return NULL;
 298         }
 299
 300         INIT_LIST_HEAD(&fdlocks->locks);
 301         fdlocks->cfile = cfile;
 302         cfile->llist = fdlocks;
 303         down_write(&cinode->lock_sem);
 304         list_add(&fdlocks->llist, &cinode->llist);
 305         up_write(&cinode->lock_sem);
 306
 307         cfile->count = 1;
 308         cfile->pid = current->tgid;
 309         cfile->uid = current_fsuid();
 310         cfile->dentry = dget(dentry);
 311         cfile->f_flags = file->f_flags;
 312         cfile->invalidHandle = false;
 313         cfile->tlink = cifs_get_tlink(tlink);
 314         INIT_WORK(&cfile->oplock_break, cifs_oplock_break);
 315         mutex_init(&cfile->fh_mutex);
 316         spin_lock_init(&cfile->file_info_lock);
 317
 318         cifs_sb_active(inode->i_sb);
 319
 320         /*
 321          * If the server returned a read oplock and we have mandatory brlocks,
 322          * set oplock level to None.
 323          */
 324         if (server->ops->is_read_op(oplock) && cifs_has_mand_locks(cinode)) {
 325                 cifs_dbg(FYI, "Reset oplock val from read to None due to mand locks\n");
 326                 oplock = 0;
 327         }
 328
 329         spin_lock(&tcon->open_file_lock);
 330         if (fid->pending_open->oplock != CIFS_OPLOCK_NO_CHANGE && oplock)
 331                 oplock = fid->pending_open->oplock;
 332         list_del(&fid->pending_open->olist);
 333
 334         fid->purge_cache = false;
 335         server->ops->set_fid(cfile, fid, oplock);
 336
 337         list_add(&cfile->tlist, &tcon->openFileList);
 338         atomic_inc(&tcon->num_local_opens);
 339
 340         /* if readable file instance put first in list*/
 341         if (file->f_mode & FMODE_READ)
 342                 list_add(&cfile->flist, &cinode->openFileList);
 343         else
 344                 list_add_tail(&cfile->flist, &cinode->openFileList);
 345         spin_unlock(&tcon->open_file_lock);
 346
 347         if (fid->purge_cache)
 348                 cifs_zap_mapping(inode);
 349
 350         file->private_data = cfile;
 351         return cfile;
 352 }
 353
 354 struct cifsFileInfo *
 355 cifsFileInfo_get(struct cifsFileInfo *cifs_file)
 356 {
 357         spin_lock(&cifs_file->file_info_lock);
 358         cifsFileInfo_get_locked(cifs_file);
 359         spin_unlock(&cifs_file->file_info_lock);
 360         return cifs_file;
 361 }
 362
 363 /*
 364  * Release a reference on the file private data. This may involve closing
 365  * the filehandle out on the server. Must be called without holding
 366  * tcon->open_file_lock and cifs_file->file_info_lock.
 367  */
 368 void cifsFileInfo_put(struct cifsFileInfo *cifs_file)
 369 {
 370         struct inode *inode = d_inode(cifs_file->dentry);
 371         struct cifs_tcon *tcon = tlink_tcon(cifs_file->tlink);
 372         struct TCP_Server_Info *server = tcon->ses->server;
 373         struct cifsInodeInfo *cifsi = CIFS_I(inode);
 374         struct super_block *sb = inode->i_sb;
 375         struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
 376         struct cifsLockInfo *li, *tmp;
 377         struct cifs_fid fid;
 378         struct cifs_pending_open open;
 379         bool oplock_break_cancelled;
 380
 381         spin_lock(&tcon->open_file_lock);
 382
 383         spin_lock(&cifs_file->file_info_lock);
 384         if (--cifs_file->count > 0) {
 385                 spin_unlock(&cifs_file->file_info_lock);
 386                 spin_unlock(&tcon->open_file_lock);
 387                 return;
 388         }
 389         spin_unlock(&cifs_file->file_info_lock);
 390
 391         if (server->ops->get_lease_key)
 392                 server->ops->get_lease_key(inode, &fid);
 393
 394         /* store open in pending opens to make sure we don't miss lease break */
 395         cifs_add_pending_open_locked(&fid, cifs_file->tlink, &open);
 396
 397         /* remove it from the lists */
 398         list_del(&cifs_file->flist);
 399         list_del(&cifs_file->tlist);
 400         atomic_dec(&tcon->num_local_opens);
 401
 402         if (list_empty(&cifsi->openFileList)) {
 403                 cifs_dbg(FYI, "closing last open instance for inode %p\n",
 404                          d_inode(cifs_file->dentry));
 405                 /*
 406                  * In strict cache mode we need invalidate mapping on the last
 407                  * close  because it may cause a error when we open this file
 408                  * again and get at least level II oplock.
 409                  */
 410                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_STRICT_IO)
 411                         set_bit(CIFS_INO_INVALID_MAPPING, &cifsi->flags);
 412                 cifs_set_oplock_level(cifsi, 0);
 413         }
 414
 415         spin_unlock(&tcon->open_file_lock);
 416
 417         oplock_break_cancelled = cancel_work_sync(&cifs_file->oplock_break);
 418
 419         if (!tcon->need_reconnect && !cifs_file->invalidHandle) {
 420                 struct TCP_Server_Info *server = tcon->ses->server;
 421                 unsigned int xid;
 422
 423                 xid = get_xid();
 424                 if (server->ops->close)
 425                         server->ops->close(xid, tcon, &cifs_file->fid);
 426                 _free_xid(xid);
 427         }
 428
 429         if (oplock_break_cancelled)
 430                 cifs_done_oplock_break(cifsi);
 431
 432         cifs_del_pending_open(&open);
 433
 434         /*
 435          * Delete any outstanding lock records. We'll lose them when the file
 436          * is closed anyway.
 437          */
 438         down_write(&cifsi->lock_sem);
 439         list_for_each_entry_safe(li, tmp, &cifs_file->llist->locks, llist) {
 440                 list_del(&li->llist);
 441                 cifs_del_lock_waiters(li);
 442                 kfree(li);
 443         }
 444         list_del(&cifs_file->llist->llist);
 445         kfree(cifs_file->llist);
 446         up_write(&cifsi->lock_sem);
 447
 448         cifs_put_tlink(cifs_file->tlink);
 449         dput(cifs_file->dentry);
 450         cifs_sb_deactive(sb);
 451         kfree(cifs_file);
 452 }
 453
 454 int cifs_open(struct inode *inode, struct file *file)
 455
 456 {
 457         int rc = -EACCES;
 458         unsigned int xid;
 459         __u32 oplock;
 460         struct cifs_sb_info *cifs_sb;
 461         struct TCP_Server_Info *server;
 462         struct cifs_tcon *tcon;
 463         struct tcon_link *tlink;
 464         struct cifsFileInfo *cfile = NULL;
 465         char *full_path = NULL;
 466         bool posix_open_ok = false;
 467         struct cifs_fid fid;
 468         struct cifs_pending_open open;
 469
 470         xid = get_xid();
 471
 472         cifs_sb = CIFS_SB(inode->i_sb);
 473         tlink = cifs_sb_tlink(cifs_sb);
 474         if (IS_ERR(tlink)) {
 475                 free_xid(xid);
 476                 return PTR_ERR(tlink);
 477         }
 478         tcon = tlink_tcon(tlink);
 479         server = tcon->ses->server;
 480
 481         full_path = build_path_from_dentry(file_dentry(file));
 482         if (full_path == NULL) {
 483                 rc = -ENOMEM;
 484                 goto out;
 485         }
 486
 487         cifs_dbg(FYI, "inode = 0x%p file flags are 0x%x for %s\n",
 488                  inode, file->f_flags, full_path);
 489
 490         if (file->f_flags & O_DIRECT &&
 491             cifs_sb->mnt_cifs_flags & CIFS_MOUNT_STRICT_IO) {
 492                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_BRL)
 493                         file->f_op = &cifs_file_direct_nobrl_ops;
 494                 else
 495                         file->f_op = &cifs_file_direct_ops;
 496         }
 497
 498         if (server->oplocks)
 499                 oplock = REQ_OPLOCK;
 500         else
 501                 oplock = 0;
 502
 503         if (!tcon->broken_posix_open && tcon->unix_ext &&
 504             cap_unix(tcon->ses) && (CIFS_UNIX_POSIX_PATH_OPS_CAP &
 505                                 le64_to_cpu(tcon->fsUnixInfo.Capability))) {
 506                 /* can not refresh inode info since size could be stale */
 507                 rc = cifs_posix_open(full_path, &inode, inode->i_sb,
 508                                 cifs_sb->mnt_file_mode /* ignored */,
 509                                 file->f_flags, &oplock, &fid.netfid, xid);
 510                 if (rc == 0) {
 511                         cifs_dbg(FYI, "posix open succeeded\n");
 512                         posix_open_ok = true;
 513                 } else if ((rc == -EINVAL) || (rc == -EOPNOTSUPP)) {
 514                         if (tcon->ses->serverNOS)
 515                                 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",
 516                                          tcon->ses->serverName,
 517                                          tcon->ses->serverNOS);
 518                         tcon->broken_posix_open = true;
 519                 } else if ((rc != -EIO) && (rc != -EREMOTE) &&
 520                          (rc != -EOPNOTSUPP)) /* path not found or net err */
 521                         goto out;
 522                 /*
 523                  * Else fallthrough to retry open the old way on network i/o
 524                  * or DFS errors.
 525                  */
 526         }
 527
 528         if (server->ops->get_lease_key)
 529                 server->ops->get_lease_key(inode, &fid);
 530
 531         cifs_add_pending_open(&fid, tlink, &open);
 532
 533         if (!posix_open_ok) {
 534                 if (server->ops->get_lease_key)
 535                         server->ops->get_lease_key(inode, &fid);
 536
 537                 rc = cifs_nt_open(full_path, inode, cifs_sb, tcon,
 538                                   file->f_flags, &oplock, &fid, xid);
 539                 if (rc) {
 540                         cifs_del_pending_open(&open);
 541                         goto out;
 542                 }
 543         }
 544
 545         cfile = cifs_new_fileinfo(&fid, file, tlink, oplock);
 546         if (cfile == NULL) {
 547                 if (server->ops->close)
 548                         server->ops->close(xid, tcon, &fid);
 549                 cifs_del_pending_open(&open);
 550                 rc = -ENOMEM;
 551                 goto out;
 552         }
 553
 554         cifs_fscache_set_inode_cookie(inode, file);
 555
 556         if ((oplock & CIFS_CREATE_ACTION) && !posix_open_ok && tcon->unix_ext) {
 557                 /*
 558                  * Time to set mode which we can not set earlier due to
 559                  * problems creating new read-only files.
 560                  */
 561                 struct cifs_unix_set_info_args args = {
 562                         .mode   = inode->i_mode,
 563                         .uid    = INVALID_UID, /* no change */
 564                         .gid    = INVALID_GID, /* no change */
 565                         .ctime  = NO_CHANGE_64,
 566                         .atime  = NO_CHANGE_64,
 567                         .mtime  = NO_CHANGE_64,
 568                         .device = 0,
 569                 };
 570                 CIFSSMBUnixSetFileInfo(xid, tcon, &args, fid.netfid,
 571                                        cfile->pid);
 572         }
 573
 574 out:
 575         kfree(full_path);
 576         free_xid(xid);
 577         cifs_put_tlink(tlink);
 578         return rc;
 579 }
 580
 581 static int cifs_push_posix_locks(struct cifsFileInfo *cfile);
 582
 583 /*
 584  * Try to reacquire byte range locks that were released when session
 585  * to server was lost.
 586  */
 587 static int
 588 cifs_relock_file(struct cifsFileInfo *cfile)
 589 {
 590         struct cifs_sb_info *cifs_sb = CIFS_SB(cfile->dentry->d_sb);
 591         struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
 592         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
 593         int rc = 0;
 594
 595         down_read_nested(&cinode->lock_sem, SINGLE_DEPTH_NESTING);
 596         if (cinode->can_cache_brlcks) {
 597                 /* can cache locks - no need to relock */
 598                 up_read(&cinode->lock_sem);
 599                 return rc;
 600         }
 601
 602         if (cap_unix(tcon->ses) &&
 603             (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
 604             ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
 605                 rc = cifs_push_posix_locks(cfile);
 606         else
 607                 rc = tcon->ses->server->ops->push_mand_locks(cfile);
 608
 609         up_read(&cinode->lock_sem);
 610         return rc;
 611 }
 612
 613 static int
 614 cifs_reopen_file(struct cifsFileInfo *cfile, bool can_flush)
 615 {
 616         int rc = -EACCES;
 617         unsigned int xid;
 618         __u32 oplock;
 619         struct cifs_sb_info *cifs_sb;
 620         struct cifs_tcon *tcon;
 621         struct TCP_Server_Info *server;
 622         struct cifsInodeInfo *cinode;
 623         struct inode *inode;
 624         char *full_path = NULL;
 625         int desired_access;
 626         int disposition = FILE_OPEN;
 627         int create_options = CREATE_NOT_DIR;
 628         struct cifs_open_parms oparms;
 629
 630         xid = get_xid();
 631         mutex_lock(&cfile->fh_mutex);
 632         if (!cfile->invalidHandle) {
 633                 mutex_unlock(&cfile->fh_mutex);
 634                 rc = 0;
 635                 free_xid(xid);
 636                 return rc;
 637         }
 638
 639         inode = d_inode(cfile->dentry);
 640         cifs_sb = CIFS_SB(inode->i_sb);
 641         tcon = tlink_tcon(cfile->tlink);
 642         server = tcon->ses->server;
 643
 644         /*
 645          * Can not grab rename sem here because various ops, including those
 646          * that already have the rename sem can end up causing writepage to get
 647          * called and if the server was down that means we end up here, and we
 648          * can never tell if the caller already has the rename_sem.
 649          */
 650         full_path = build_path_from_dentry(cfile->dentry);
 651         if (full_path == NULL) {
 652                 rc = -ENOMEM;
 653                 mutex_unlock(&cfile->fh_mutex);
 654                 free_xid(xid);
 655                 return rc;
 656         }
 657
 658         cifs_dbg(FYI, "inode = 0x%p file flags 0x%x for %s\n",
 659                  inode, cfile->f_flags, full_path);
 660
 661         if (tcon->ses->server->oplocks)
 662                 oplock = REQ_OPLOCK;
 663         else
 664                 oplock = 0;
 665
 666         if (tcon->unix_ext && cap_unix(tcon->ses) &&
 667             (CIFS_UNIX_POSIX_PATH_OPS_CAP &
 668                                 le64_to_cpu(tcon->fsUnixInfo.Capability))) {
 669                 /*
 670                  * O_CREAT, O_EXCL and O_TRUNC already had their effect on the
 671                  * original open. Must mask them off for a reopen.
 672                  */
 673                 unsigned int oflags = cfile->f_flags &
 674                                                 ~(O_CREAT | O_EXCL | O_TRUNC);
 675
 676                 rc = cifs_posix_open(full_path, NULL, inode->i_sb,
 677                                      cifs_sb->mnt_file_mode /* ignored */,
 678                                      oflags, &oplock, &cfile->fid.netfid, xid);
 679                 if (rc == 0) {
 680                         cifs_dbg(FYI, "posix reopen succeeded\n");
 681                         oparms.reconnect = true;
 682                         goto reopen_success;
 683                 }
 684                 /*
 685                  * fallthrough to retry open the old way on errors, especially
 686                  * in the reconnect path it is important to retry hard
 687                  */
 688         }
 689
 690         desired_access = cifs_convert_flags(cfile->f_flags);
 691
 692         if (backup_cred(cifs_sb))
 693                 create_options |= CREATE_OPEN_BACKUP_INTENT;
 694
 695         if (server->ops->get_lease_key)
 696                 server->ops->get_lease_key(inode, &cfile->fid);
 697
 698         oparms.tcon = tcon;
 699         oparms.cifs_sb = cifs_sb;
 700         oparms.desired_access = desired_access;
 701         oparms.create_options = create_options;
 702         oparms.disposition = disposition;
 703         oparms.path = full_path;
 704         oparms.fid = &cfile->fid;
 705         oparms.reconnect = true;
 706
 707         /*
 708          * Can not refresh inode by passing in file_info buf to be returned by
 709          * ops->open and then calling get_inode_info with returned buf since
 710          * file might have write behind data that needs to be flushed and server
 711          * version of file size can be stale. If we knew for sure that inode was
 712          * not dirty locally we could do this.
 713          */
 714         rc = server->ops->open(xid, &oparms, &oplock, NULL);
 715         if (rc == -ENOENT && oparms.reconnect == false) {
 716                 /* durable handle timeout is expired - open the file again */
 717                 rc = server->ops->open(xid, &oparms, &oplock, NULL);
 718                 /* indicate that we need to relock the file */
 719                 oparms.reconnect = true;
 720         }
 721
 722         if (rc) {
 723                 mutex_unlock(&cfile->fh_mutex);
 724                 cifs_dbg(FYI, "cifs_reopen returned 0x%x\n", rc);
 725                 cifs_dbg(FYI, "oplock: %d\n", oplock);
 726                 goto reopen_error_exit;
 727         }
 728
 729 reopen_success:
 730         cfile->invalidHandle = false;
 731         mutex_unlock(&cfile->fh_mutex);
 732         cinode = CIFS_I(inode);
 733
 734         if (can_flush) {
 735                 rc = filemap_write_and_wait(inode->i_mapping);
 736                 if (!is_interrupt_error(rc))
 737                         mapping_set_error(inode->i_mapping, rc);
 738
 739                 if (tcon->unix_ext)
 740                         rc = cifs_get_inode_info_unix(&inode, full_path,
 741                                                       inode->i_sb, xid);
 742                 else
 743                         rc = cifs_get_inode_info(&inode, full_path, NULL,
 744                                                  inode->i_sb, xid, NULL);
 745         }
 746         /*
 747          * Else we are writing out data to server already and could deadlock if
 748          * we tried to flush data, and since we do not know if we have data that
 749          * would invalidate the current end of file on the server we can not go
 750          * to the server to get the new inode info.
 751          */
 752
 753         /*
 754          * If the server returned a read oplock and we have mandatory brlocks,
 755          * set oplock level to None.
 756          */
 757         if (server->ops->is_read_op(oplock) && cifs_has_mand_locks(cinode)) {
 758                 cifs_dbg(FYI, "Reset oplock val from read to None due to mand locks\n");
 759                 oplock = 0;
 760         }
 761
 762         server->ops->set_fid(cfile, &cfile->fid, oplock);
 763         if (oparms.reconnect)
 764                 cifs_relock_file(cfile);
 765
 766 reopen_error_exit:
 767         kfree(full_path);
 768         free_xid(xid);
 769         return rc;
 770 }
 771
 772 int cifs_close(struct inode *inode, struct file *file)
 773 {
 774         if (file->private_data != NULL) {
 775                 cifsFileInfo_put(file->private_data);
 776                 file->private_data = NULL;
 777         }
 778
 779         /* return code from the ->release op is always ignored */
 780         return 0;
 781 }
 782
 783 void
 784 cifs_reopen_persistent_handles(struct cifs_tcon *tcon)
 785 {
 786         struct cifsFileInfo *open_file;
 787         struct list_head *tmp;
 788         struct list_head *tmp1;
 789         struct list_head tmp_list;
 790
 791         if (!tcon->use_persistent || !tcon->need_reopen_files)
 792                 return;
 793
 794         tcon->need_reopen_files = false;
 795
 796         cifs_dbg(FYI, "Reopen persistent handles");
 797         INIT_LIST_HEAD(&tmp_list);
 798
 799         /* list all files open on tree connection, reopen resilient handles  */
 800         spin_lock(&tcon->open_file_lock);
 801         list_for_each(tmp, &tcon->openFileList) {
 802                 open_file = list_entry(tmp, struct cifsFileInfo, tlist);
 803                 if (!open_file->invalidHandle)
 804                         continue;
 805                 cifsFileInfo_get(open_file);
 806                 list_add_tail(&open_file->rlist, &tmp_list);
 807         }
 808         spin_unlock(&tcon->open_file_lock);
 809
 810         list_for_each_safe(tmp, tmp1, &tmp_list) {
 811                 open_file = list_entry(tmp, struct cifsFileInfo, rlist);
 812                 if (cifs_reopen_file(open_file, false /* do not flush */))
 813                         tcon->need_reopen_files = true;
 814                 list_del_init(&open_file->rlist);
 815                 cifsFileInfo_put(open_file);
 816         }
 817 }
 818
 819 int cifs_closedir(struct inode *inode, struct file *file)
 820 {
 821         int rc = 0;
 822         unsigned int xid;
 823         struct cifsFileInfo *cfile = file->private_data;
 824         struct cifs_tcon *tcon;
 825         struct TCP_Server_Info *server;
 826         char *buf;
 827
 828         cifs_dbg(FYI, "Closedir inode = 0x%p\n", inode);
 829
 830         if (cfile == NULL)
 831                 return rc;
 832
 833         xid = get_xid();
 834         tcon = tlink_tcon(cfile->tlink);
 835         server = tcon->ses->server;
 836
 837         cifs_dbg(FYI, "Freeing private data in close dir\n");
 838         spin_lock(&cfile->file_info_lock);
 839         if (server->ops->dir_needs_close(cfile)) {
 840                 cfile->invalidHandle = true;
 841                 spin_unlock(&cfile->file_info_lock);
 842                 if (server->ops->close_dir)
 843                         rc = server->ops->close_dir(xid, tcon, &cfile->fid);
 844                 else
 845                         rc = -ENOSYS;
 846                 cifs_dbg(FYI, "Closing uncompleted readdir with rc %d\n", rc);
 847                 /* not much we can do if it fails anyway, ignore rc */
 848                 rc = 0;
 849         } else
 850                 spin_unlock(&cfile->file_info_lock);
 851
 852         buf = cfile->srch_inf.ntwrk_buf_start;
 853         if (buf) {
 854                 cifs_dbg(FYI, "closedir free smb buf in srch struct\n");
 855                 cfile->srch_inf.ntwrk_buf_start = NULL;
 856                 if (cfile->srch_inf.smallBuf)
 857                         cifs_small_buf_release(buf);
 858                 else
 859                         cifs_buf_release(buf);
 860         }
 861
 862         cifs_put_tlink(cfile->tlink);
 863         kfree(file->private_data);
 864         file->private_data = NULL;
 865         /* BB can we lock the filestruct while this is going on? */
 866         free_xid(xid);
 867         return rc;
 868 }
 869
 870 static struct cifsLockInfo *
 871 cifs_lock_init(__u64 offset, __u64 length, __u8 type, __u16 flags)
 872 {
 873         struct cifsLockInfo *lock =
 874                 kmalloc(sizeof(struct cifsLockInfo), GFP_KERNEL);
 875         if (!lock)
 876                 return lock;
 877         lock->offset = offset;
 878         lock->length = length;
 879         lock->type = type;
 880         lock->pid = current->tgid;
 881         lock->flags = flags;
 882         INIT_LIST_HEAD(&lock->blist);
 883         init_waitqueue_head(&lock->block_q);
 884         return lock;
 885 }
 886
 887 void
 888 cifs_del_lock_waiters(struct cifsLockInfo *lock)
 889 {
 890         struct cifsLockInfo *li, *tmp;
 891         list_for_each_entry_safe(li, tmp, &lock->blist, blist) {
 892                 list_del_init(&li->blist);
 893                 wake_up(&li->block_q);
 894         }
 895 }
 896
 897 #define CIFS_LOCK_OP    0
 898 #define CIFS_READ_OP    1
 899 #define CIFS_WRITE_OP   2
 900
 901 /* @rw_check : 0 - no op, 1 - read, 2 - write */
 902 static bool
 903 cifs_find_fid_lock_conflict(struct cifs_fid_locks *fdlocks, __u64 offset,
 904                             __u64 length, __u8 type, __u16 flags,
 905                             struct cifsFileInfo *cfile,
 906                             struct cifsLockInfo **conf_lock, int rw_check)
 907 {
 908         struct cifsLockInfo *li;
 909         struct cifsFileInfo *cur_cfile = fdlocks->cfile;
 910         struct TCP_Server_Info *server = tlink_tcon(cfile->tlink)->ses->server;
 911
 912         list_for_each_entry(li, &fdlocks->locks, llist) {
 913                 if (offset + length <= li->offset ||
 914                     offset >= li->offset + li->length)
 915                         continue;
 916                 if (rw_check != CIFS_LOCK_OP && current->tgid == li->pid &&
 917                     server->ops->compare_fids(cfile, cur_cfile)) {
 918                         /* shared lock prevents write op through the same fid */
 919                         if (!(li->type & server->vals->shared_lock_type) ||
 920                             rw_check != CIFS_WRITE_OP)
 921                                 continue;
 922                 }
 923                 if ((type & server->vals->shared_lock_type) &&
 924                     ((server->ops->compare_fids(cfile, cur_cfile) &&
 925                      current->tgid == li->pid) || type == li->type))
 926                         continue;
 927                 if (rw_check == CIFS_LOCK_OP &&
 928                     (flags & FL_OFDLCK) && (li->flags & FL_OFDLCK) &&
 929                     server->ops->compare_fids(cfile, cur_cfile))
 930                         continue;
 931                 if (conf_lock)
 932                         *conf_lock = li;
 933                 return true;
 934         }
 935         return false;
 936 }
 937
 938 bool
 939 cifs_find_lock_conflict(struct cifsFileInfo *cfile, __u64 offset, __u64 length,
 940                         __u8 type, __u16 flags,
 941                         struct cifsLockInfo **conf_lock, int rw_check)
 942 {
 943         bool rc = false;
 944         struct cifs_fid_locks *cur;
 945         struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
 946
 947         list_for_each_entry(cur, &cinode->llist, llist) {
 948                 rc = cifs_find_fid_lock_conflict(cur, offset, length, type,
 949                                                  flags, cfile, conf_lock,
 950                                                  rw_check);
 951                 if (rc)
 952                         break;
 953         }
 954
 955         return rc;
 956 }
 957
 958 /*
 959  * Check if there is another lock that prevents us to set the lock (mandatory
 960  * style). If such a lock exists, update the flock structure with its
 961  * properties. Otherwise, set the flock type to F_UNLCK if we can cache brlocks
 962  * or leave it the same if we can't. Returns 0 if we don't need to request to
 963  * the server or 1 otherwise.
 964  */
 965 static int
 966 cifs_lock_test(struct cifsFileInfo *cfile, __u64 offset, __u64 length,
 967                __u8 type, struct file_lock *flock)
 968 {
 969         int rc = 0;
 970         struct cifsLockInfo *conf_lock;
 971         struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
 972         struct TCP_Server_Info *server = tlink_tcon(cfile->tlink)->ses->server;
 973         bool exist;
 974
 975         down_read(&cinode->lock_sem);
 976
 977         exist = cifs_find_lock_conflict(cfile, offset, length, type,
 978                                         flock->fl_flags, &conf_lock,
 979                                         CIFS_LOCK_OP);
 980         if (exist) {
 981                 flock->fl_start = conf_lock->offset;
 982                 flock->fl_end = conf_lock->offset + conf_lock->length - 1;
 983                 flock->fl_pid = conf_lock->pid;
 984                 if (conf_lock->type & server->vals->shared_lock_type)
 985                         flock->fl_type = F_RDLCK;
 986                 else
 987                         flock->fl_type = F_WRLCK;
 988         } else if (!cinode->can_cache_brlcks)
 989                 rc = 1;
 990         else
 991                 flock->fl_type = F_UNLCK;
 992
 993         up_read(&cinode->lock_sem);
 994         return rc;
 995 }
 996
 997 static void
 998 cifs_lock_add(struct cifsFileInfo *cfile, struct cifsLockInfo *lock)
 999 {
1000         struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
1001         down_write(&cinode->lock_sem);
1002         list_add_tail(&lock->llist, &cfile->llist->locks);
1003         up_write(&cinode->lock_sem);
1004 }
1005
1006 /*
1007  * Set the byte-range lock (mandatory style). Returns:
1008  * 1) 0, if we set the lock and don't need to request to the server;
1009  * 2) 1, if no locks prevent us but we need to request to the server;
1010  * 3) -EACCES, if there is a lock that prevents us and wait is false.
1011  */
1012 static int
1013 cifs_lock_add_if(struct cifsFileInfo *cfile, struct cifsLockInfo *lock,
1014                  bool wait)
1015 {
1016         struct cifsLockInfo *conf_lock;
1017         struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
1018         bool exist;
1019         int rc = 0;
1020
1021 try_again:
1022         exist = false;
1023         down_write(&cinode->lock_sem);
1024
1025         exist = cifs_find_lock_conflict(cfile, lock->offset, lock->length,
1026                                         lock->type, lock->flags, &conf_lock,
1027                                         CIFS_LOCK_OP);
1028         if (!exist && cinode->can_cache_brlcks) {
1029                 list_add_tail(&lock->llist, &cfile->llist->locks);
1030                 up_write(&cinode->lock_sem);
1031                 return rc;
1032         }
1033
1034         if (!exist)
1035                 rc = 1;
1036         else if (!wait)
1037                 rc = -EACCES;
1038         else {
1039                 list_add_tail(&lock->blist, &conf_lock->blist);
1040                 up_write(&cinode->lock_sem);
1041                 rc = wait_event_interruptible(lock->block_q,
1042                                         (lock->blist.prev == &lock->blist) &&
1043                                         (lock->blist.next == &lock->blist));
1044                 if (!rc)
1045                         goto try_again;
1046                 down_write(&cinode->lock_sem);
1047                 list_del_init(&lock->blist);
1048         }
1049
1050         up_write(&cinode->lock_sem);
1051         return rc;
1052 }
1053
1054 /*
1055  * Check if there is another lock that prevents us to set the lock (posix
1056  * style). If such a lock exists, update the flock structure with its
1057  * properties. Otherwise, set the flock type to F_UNLCK if we can cache brlocks
1058  * or leave it the same if we can't. Returns 0 if we don't need to request to
1059  * the server or 1 otherwise.
1060  */
1061 static int
1062 cifs_posix_lock_test(struct file *file, struct file_lock *flock)
1063 {
1064         int rc = 0;
1065         struct cifsInodeInfo *cinode = CIFS_I(file_inode(file));
1066         unsigned char saved_type = flock->fl_type;
1067
1068         if ((flock->fl_flags & FL_POSIX) == 0)
1069                 return 1;
1070
1071         down_read(&cinode->lock_sem);
1072         posix_test_lock(file, flock);
1073
1074         if (flock->fl_type == F_UNLCK && !cinode->can_cache_brlcks) {
1075                 flock->fl_type = saved_type;
1076                 rc = 1;
1077         }
1078
1079         up_read(&cinode->lock_sem);
1080         return rc;
1081 }
1082
1083 /*
1084  * Set the byte-range lock (posix style). Returns:
1085  * 1) 0, if we set the lock and don't need to request to the server;
1086  * 2) 1, if we need to request to the server;
1087  * 3) <0, if the error occurs while setting the lock.
1088  */
1089 static int
1090 cifs_posix_lock_set(struct file *file, struct file_lock *flock)
1091 {
1092         struct cifsInodeInfo *cinode = CIFS_I(file_inode(file));
1093         int rc = 1;
1094
1095         if ((flock->fl_flags & FL_POSIX) == 0)
1096                 return rc;
1097
1098 try_again:
1099         down_write(&cinode->lock_sem);
1100         if (!cinode->can_cache_brlcks) {
1101                 up_write(&cinode->lock_sem);
1102                 return rc;
1103         }
1104
1105         rc = posix_lock_file(file, flock, NULL);
1106         up_write(&cinode->lock_sem);
1107         if (rc == FILE_LOCK_DEFERRED) {
1108                 rc = wait_event_interruptible(flock->fl_wait, !flock->fl_blocker);
1109                 if (!rc)
1110                         goto try_again;
1111                 locks_delete_block(flock);
1112         }
1113         return rc;
1114 }
1115
1116 int
1117 cifs_push_mandatory_locks(struct cifsFileInfo *cfile)
1118 {
1119         unsigned int xid;
1120         int rc = 0, stored_rc;
1121         struct cifsLockInfo *li, *tmp;
1122         struct cifs_tcon *tcon;
1123         unsigned int num, max_num, max_buf;
1124         LOCKING_ANDX_RANGE *buf, *cur;
1125         static const int types[] = {
1126                 LOCKING_ANDX_LARGE_FILES,
1127                 LOCKING_ANDX_SHARED_LOCK | LOCKING_ANDX_LARGE_FILES
1128         };
1129         int i;
1130
1131         xid = get_xid();
1132         tcon = tlink_tcon(cfile->tlink);
1133
1134         /*
1135          * Accessing maxBuf is racy with cifs_reconnect - need to store value
1136          * and check it before using.
1137          */
1138         max_buf = tcon->ses->server->maxBuf;
1139         if (max_buf < (sizeof(struct smb_hdr) + sizeof(LOCKING_ANDX_RANGE))) {
1140                 free_xid(xid);
1141                 return -EINVAL;
1142         }
1143
1144         BUILD_BUG_ON(sizeof(struct smb_hdr) + sizeof(LOCKING_ANDX_RANGE) >
1145                      PAGE_SIZE);
1146         max_buf = min_t(unsigned int, max_buf - sizeof(struct smb_hdr),
1147                         PAGE_SIZE);
1148         max_num = (max_buf - sizeof(struct smb_hdr)) /
1149                                                 sizeof(LOCKING_ANDX_RANGE);
1150         buf = kcalloc(max_num, sizeof(LOCKING_ANDX_RANGE), GFP_KERNEL);
1151         if (!buf) {
1152                 free_xid(xid);
1153                 return -ENOMEM;
1154         }
1155
1156         for (i = 0; i < 2; i++) {
1157                 cur = buf;
1158                 num = 0;
1159                 list_for_each_entry_safe(li, tmp, &cfile->llist->locks, llist) {
1160                         if (li->type != types[i])
1161                                 continue;
1162                         cur->Pid = cpu_to_le16(li->pid);
1163                         cur->LengthLow = cpu_to_le32((u32)li->length);
1164                         cur->LengthHigh = cpu_to_le32((u32)(li->length>>32));
1165                         cur->OffsetLow = cpu_to_le32((u32)li->offset);
1166                         cur->OffsetHigh = cpu_to_le32((u32)(li->offset>>32));
1167                         if (++num == max_num) {
1168                                 stored_rc = cifs_lockv(xid, tcon,
1169                                                        cfile->fid.netfid,
1170                                                        (__u8)li->type, 0, num,
1171                                                        buf);
1172                                 if (stored_rc)
1173                                         rc = stored_rc;
1174                                 cur = buf;
1175                                 num = 0;
1176                         } else
1177                                 cur++;
1178                 }
1179
1180                 if (num) {
1181                         stored_rc = cifs_lockv(xid, tcon, cfile->fid.netfid,
1182                                                (__u8)types[i], 0, num, buf);
1183                         if (stored_rc)
1184                                 rc = stored_rc;
1185                 }
1186         }
1187
1188         kfree(buf);
1189         free_xid(xid);
1190         return rc;
1191 }
1192
1193 static __u32
1194 hash_lockowner(fl_owner_t owner)
1195 {
1196         return cifs_lock_secret ^ hash32_ptr((const void *)owner);
1197 }
1198
1199 struct lock_to_push {
1200         struct list_head llist;
1201         __u64 offset;
1202         __u64 length;
1203         __u32 pid;
1204         __u16 netfid;
1205         __u8 type;
1206 };
1207
1208 static int
1209 cifs_push_posix_locks(struct cifsFileInfo *cfile)
1210 {
1211         struct inode *inode = d_inode(cfile->dentry);
1212         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1213         struct file_lock *flock;
1214         struct file_lock_context *flctx = inode->i_flctx;
1215         unsigned int count = 0, i;
1216         int rc = 0, xid, type;
1217         struct list_head locks_to_send, *el;
1218         struct lock_to_push *lck, *tmp;
1219         __u64 length;
1220
1221         xid = get_xid();
1222
1223         if (!flctx)
1224                 goto out;
1225
1226         spin_lock(&flctx->flc_lock);
1227         list_for_each(el, &flctx->flc_posix) {
1228                 count++;
1229         }
1230         spin_unlock(&flctx->flc_lock);
1231
1232         INIT_LIST_HEAD(&locks_to_send);
1233
1234         /*
1235          * Allocating count locks is enough because no FL_POSIX locks can be
1236          * added to the list while we are holding cinode->lock_sem that
1237          * protects locking operations of this inode.
1238          */
1239         for (i = 0; i < count; i++) {
1240                 lck = kmalloc(sizeof(struct lock_to_push), GFP_KERNEL);
1241                 if (!lck) {
1242                         rc = -ENOMEM;
1243                         goto err_out;
1244                 }
1245                 list_add_tail(&lck->llist, &locks_to_send);
1246         }
1247
1248         el = locks_to_send.next;
1249         spin_lock(&flctx->flc_lock);
1250         list_for_each_entry(flock, &flctx->flc_posix, fl_list) {
1251                 if (el == &locks_to_send) {
1252                         /*
1253                          * The list ended. We don't have enough allocated
1254                          * structures - something is really wrong.
1255                          */
1256                         cifs_dbg(VFS, "Can't push all brlocks!\n");
1257                         break;
1258                 }
1259                 length = 1 + flock->fl_end - flock->fl_start;
1260                 if (flock->fl_type == F_RDLCK || flock->fl_type == F_SHLCK)
1261                         type = CIFS_RDLCK;
1262                 else
1263                         type = CIFS_WRLCK;
1264                 lck = list_entry(el, struct lock_to_push, llist);
1265                 lck->pid = hash_lockowner(flock->fl_owner);
1266                 lck->netfid = cfile->fid.netfid;
1267                 lck->length = length;
1268                 lck->type = type;
1269                 lck->offset = flock->fl_start;
1270         }
1271         spin_unlock(&flctx->flc_lock);
1272
1273         list_for_each_entry_safe(lck, tmp, &locks_to_send, llist) {
1274                 int stored_rc;
1275
1276                 stored_rc = CIFSSMBPosixLock(xid, tcon, lck->netfid, lck->pid,
1277                                              lck->offset, lck->length, NULL,
1278                                              lck->type, 0);
1279                 if (stored_rc)
1280                         rc = stored_rc;
1281                 list_del(&lck->llist);
1282                 kfree(lck);
1283         }
1284
1285 out:
1286         free_xid(xid);
1287         return rc;
1288 err_out:
1289         list_for_each_entry_safe(lck, tmp, &locks_to_send, llist) {
1290                 list_del(&lck->llist);
1291                 kfree(lck);
1292         }
1293         goto out;
1294 }
1295
1296 static int
1297 cifs_push_locks(struct cifsFileInfo *cfile)
1298 {
1299         struct cifs_sb_info *cifs_sb = CIFS_SB(cfile->dentry->d_sb);
1300         struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
1301         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1302         int rc = 0;
1303
1304         /* we are going to update can_cache_brlcks here - need a write access */
1305         down_write(&cinode->lock_sem);
1306         if (!cinode->can_cache_brlcks) {
1307                 up_write(&cinode->lock_sem);
1308                 return rc;
1309         }
1310
1311         if (cap_unix(tcon->ses) &&
1312             (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
1313             ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
1314                 rc = cifs_push_posix_locks(cfile);
1315         else
1316                 rc = tcon->ses->server->ops->push_mand_locks(cfile);
1317
1318         cinode->can_cache_brlcks = false;
1319         up_write(&cinode->lock_sem);
1320         return rc;
1321 }
1322
1323 static void
1324 cifs_read_flock(struct file_lock *flock, __u32 *type, int *lock, int *unlock,
1325                 bool *wait_flag, struct TCP_Server_Info *server)
1326 {
1327         if (flock->fl_flags & FL_POSIX)
1328                 cifs_dbg(FYI, "Posix\n");
1329         if (flock->fl_flags & FL_FLOCK)
1330                 cifs_dbg(FYI, "Flock\n");
1331         if (flock->fl_flags & FL_SLEEP) {
1332                 cifs_dbg(FYI, "Blocking lock\n");
1333                 *wait_flag = true;
1334         }
1335         if (flock->fl_flags & FL_ACCESS)
1336                 cifs_dbg(FYI, "Process suspended by mandatory locking - not implemented yet\n");
1337         if (flock->fl_flags & FL_LEASE)
1338                 cifs_dbg(FYI, "Lease on file - not implemented yet\n");
1339         if (flock->fl_flags &
1340             (~(FL_POSIX | FL_FLOCK | FL_SLEEP |
1341                FL_ACCESS | FL_LEASE | FL_CLOSE | FL_OFDLCK)))
1342                 cifs_dbg(FYI, "Unknown lock flags 0x%x\n", flock->fl_flags);
1343
1344         *type = server->vals->large_lock_type;
1345         if (flock->fl_type == F_WRLCK) {
1346                 cifs_dbg(FYI, "F_WRLCK\n");
1347                 *type |= server->vals->exclusive_lock_type;
1348                 *lock = 1;
1349         } else if (flock->fl_type == F_UNLCK) {
1350                 cifs_dbg(FYI, "F_UNLCK\n");
1351                 *type |= server->vals->unlock_lock_type;
1352                 *unlock = 1;
1353                 /* Check if unlock includes more than one lock range */
1354         } else if (flock->fl_type == F_RDLCK) {
1355                 cifs_dbg(FYI, "F_RDLCK\n");
1356                 *type |= server->vals->shared_lock_type;
1357                 *lock = 1;
1358         } else if (flock->fl_type == F_EXLCK) {
1359                 cifs_dbg(FYI, "F_EXLCK\n");
1360                 *type |= server->vals->exclusive_lock_type;
1361                 *lock = 1;
1362         } else if (flock->fl_type == F_SHLCK) {
1363                 cifs_dbg(FYI, "F_SHLCK\n");
1364                 *type |= server->vals->shared_lock_type;
1365                 *lock = 1;
1366         } else
1367                 cifs_dbg(FYI, "Unknown type of lock\n");
1368 }
1369
1370 static int
1371 cifs_getlk(struct file *file, struct file_lock *flock, __u32 type,
1372            bool wait_flag, bool posix_lck, unsigned int xid)
1373 {
1374         int rc = 0;
1375         __u64 length = 1 + flock->fl_end - flock->fl_start;
1376         struct cifsFileInfo *cfile = (struct cifsFileInfo *)file->private_data;
1377         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1378         struct TCP_Server_Info *server = tcon->ses->server;
1379         __u16 netfid = cfile->fid.netfid;
1380
1381         if (posix_lck) {
1382                 int posix_lock_type;
1383
1384                 rc = cifs_posix_lock_test(file, flock);
1385                 if (!rc)
1386                         return rc;
1387
1388                 if (type & server->vals->shared_lock_type)
1389                         posix_lock_type = CIFS_RDLCK;
1390                 else
1391                         posix_lock_type = CIFS_WRLCK;
1392                 rc = CIFSSMBPosixLock(xid, tcon, netfid,
1393                                       hash_lockowner(flock->fl_owner),
1394                                       flock->fl_start, length, flock,
1395                                       posix_lock_type, wait_flag);
1396                 return rc;
1397         }
1398
1399         rc = cifs_lock_test(cfile, flock->fl_start, length, type, flock);
1400         if (!rc)
1401                 return rc;
1402
1403         /* BB we could chain these into one lock request BB */
1404         rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length, type,
1405                                     1, 0, false);
1406         if (rc == 0) {
1407                 rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length,
1408                                             type, 0, 1, false);
1409                 flock->fl_type = F_UNLCK;
1410                 if (rc != 0)
1411                         cifs_dbg(VFS, "Error unlocking previously locked range %d during test of lock\n",
1412                                  rc);
1413                 return 0;
1414         }
1415
1416         if (type & server->vals->shared_lock_type) {
1417                 flock->fl_type = F_WRLCK;
1418                 return 0;
1419         }
1420
1421         type &= ~server->vals->exclusive_lock_type;
1422
1423         rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length,
1424                                     type | server->vals->shared_lock_type,
1425                                     1, 0, false);
1426         if (rc == 0) {
1427                 rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length,
1428                         type | server->vals->shared_lock_type, 0, 1, false);
1429                 flock->fl_type = F_RDLCK;
1430                 if (rc != 0)
1431                         cifs_dbg(VFS, "Error unlocking previously locked range %d during test of lock\n",
1432                                  rc);
1433         } else
1434                 flock->fl_type = F_WRLCK;
1435
1436         return 0;
1437 }
1438
1439 void
1440 cifs_move_llist(struct list_head *source, struct list_head *dest)
1441 {
1442         struct list_head *li, *tmp;
1443         list_for_each_safe(li, tmp, source)
1444                 list_move(li, dest);
1445 }
1446
1447 void
1448 cifs_free_llist(struct list_head *llist)
1449 {
1450         struct cifsLockInfo *li, *tmp;
1451         list_for_each_entry_safe(li, tmp, llist, llist) {
1452                 cifs_del_lock_waiters(li);
1453                 list_del(&li->llist);
1454                 kfree(li);
1455         }
1456 }
1457
1458 int
1459 cifs_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock,
1460                   unsigned int xid)
1461 {
1462         int rc = 0, stored_rc;
1463         static const int types[] = {
1464                 LOCKING_ANDX_LARGE_FILES,
1465                 LOCKING_ANDX_SHARED_LOCK | LOCKING_ANDX_LARGE_FILES
1466         };
1467         unsigned int i;
1468         unsigned int max_num, num, max_buf;
1469         LOCKING_ANDX_RANGE *buf, *cur;
1470         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1471         struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
1472         struct cifsLockInfo *li, *tmp;
1473         __u64 length = 1 + flock->fl_end - flock->fl_start;
1474         struct list_head tmp_llist;
1475
1476         INIT_LIST_HEAD(&tmp_llist);
1477
1478         /*
1479          * Accessing maxBuf is racy with cifs_reconnect - need to store value
1480          * and check it before using.
1481          */
1482         max_buf = tcon->ses->server->maxBuf;
1483         if (max_buf < (sizeof(struct smb_hdr) + sizeof(LOCKING_ANDX_RANGE)))
1484                 return -EINVAL;
1485
1486         BUILD_BUG_ON(sizeof(struct smb_hdr) + sizeof(LOCKING_ANDX_RANGE) >
1487                      PAGE_SIZE);
1488         max_buf = min_t(unsigned int, max_buf - sizeof(struct smb_hdr),
1489                         PAGE_SIZE);
1490         max_num = (max_buf - sizeof(struct smb_hdr)) /
1491                                                 sizeof(LOCKING_ANDX_RANGE);
1492         buf = kcalloc(max_num, sizeof(LOCKING_ANDX_RANGE), GFP_KERNEL);
1493         if (!buf)
1494                 return -ENOMEM;
1495
1496         down_write(&cinode->lock_sem);
1497         for (i = 0; i < 2; i++) {
1498                 cur = buf;
1499                 num = 0;
1500                 list_for_each_entry_safe(li, tmp, &cfile->llist->locks, llist) {
1501                         if (flock->fl_start > li->offset ||
1502                             (flock->fl_start + length) <
1503                             (li->offset + li->length))
1504                                 continue;
1505                         if (current->tgid != li->pid)
1506                                 continue;
1507                         if (types[i] != li->type)
1508                                 continue;
1509                         if (cinode->can_cache_brlcks) {
1510                                 /*
1511                                  * We can cache brlock requests - simply remove
1512                                  * a lock from the file's list.
1513                                  */
1514                                 list_del(&li->llist);
1515                                 cifs_del_lock_waiters(li);
1516                                 kfree(li);
1517                                 continue;
1518                         }
1519                         cur->Pid = cpu_to_le16(li->pid);
1520                         cur->LengthLow = cpu_to_le32((u32)li->length);
1521                         cur->LengthHigh = cpu_to_le32((u32)(li->length>>32));
1522                         cur->OffsetLow = cpu_to_le32((u32)li->offset);
1523                         cur->OffsetHigh = cpu_to_le32((u32)(li->offset>>32));
1524                         /*
1525                          * We need to save a lock here to let us add it again to
1526                          * the file's list if the unlock range request fails on
1527                          * the server.
1528                          */
1529                         list_move(&li->llist, &tmp_llist);
1530                         if (++num == max_num) {
1531                                 stored_rc = cifs_lockv(xid, tcon,
1532                                                        cfile->fid.netfid,
1533                                                        li->type, num, 0, buf);
1534                                 if (stored_rc) {
1535                                         /*
1536                                          * We failed on the unlock range
1537                                          * request - add all locks from the tmp
1538                                          * list to the head of the file's list.
1539                                          */
1540                                         cifs_move_llist(&tmp_llist,
1541                                                         &cfile->llist->locks);
1542                                         rc = stored_rc;
1543                                 } else
1544                                         /*
1545                                          * The unlock range request succeed -
1546                                          * free the tmp list.
1547                                          */
1548                                         cifs_free_llist(&tmp_llist);
1549                                 cur = buf;
1550                                 num = 0;
1551                         } else
1552                                 cur++;
1553                 }
1554                 if (num) {
1555                         stored_rc = cifs_lockv(xid, tcon, cfile->fid.netfid,
1556                                                types[i], num, 0, buf);
1557                         if (stored_rc) {
1558                                 cifs_move_llist(&tmp_llist,
1559                                                 &cfile->llist->locks);
1560                                 rc = stored_rc;
1561                         } else
1562                                 cifs_free_llist(&tmp_llist);
1563                 }
1564         }
1565
1566         up_write(&cinode->lock_sem);
1567         kfree(buf);
1568         return rc;
1569 }
1570
1571 static int
1572 cifs_setlk(struct file *file, struct file_lock *flock, __u32 type,
1573            bool wait_flag, bool posix_lck, int lock, int unlock,
1574            unsigned int xid)
1575 {
1576         int rc = 0;
1577         __u64 length = 1 + flock->fl_end - flock->fl_start;
1578         struct cifsFileInfo *cfile = (struct cifsFileInfo *)file->private_data;
1579         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1580         struct TCP_Server_Info *server = tcon->ses->server;
1581         struct inode *inode = d_inode(cfile->dentry);
1582
1583         if (posix_lck) {
1584                 int posix_lock_type;
1585
1586                 rc = cifs_posix_lock_set(file, flock);
1587                 if (!rc || rc < 0)
1588                         return rc;
1589
1590                 if (type & server->vals->shared_lock_type)
1591                         posix_lock_type = CIFS_RDLCK;
1592                 else
1593                         posix_lock_type = CIFS_WRLCK;
1594
1595                 if (unlock == 1)
1596                         posix_lock_type = CIFS_UNLCK;
1597
1598                 rc = CIFSSMBPosixLock(xid, tcon, cfile->fid.netfid,
1599                                       hash_lockowner(flock->fl_owner),
1600                                       flock->fl_start, length,
1601                                       NULL, posix_lock_type, wait_flag);
1602                 goto out;
1603         }
1604
1605         if (lock) {
1606                 struct cifsLockInfo *lock;
1607
1608                 lock = cifs_lock_init(flock->fl_start, length, type,
1609                                       flock->fl_flags);
1610                 if (!lock)
1611                         return -ENOMEM;
1612
1613                 rc = cifs_lock_add_if(cfile, lock, wait_flag);
1614                 if (rc < 0) {
1615                         kfree(lock);
1616                         return rc;
1617                 }
1618                 if (!rc)
1619                         goto out;
1620
1621                 /*
1622                  * Windows 7 server can delay breaking lease from read to None
1623                  * if we set a byte-range lock on a file - break it explicitly
1624                  * before sending the lock to the server to be sure the next
1625                  * read won't conflict with non-overlapted locks due to
1626                  * pagereading.
1627                  */
1628                 if (!CIFS_CACHE_WRITE(CIFS_I(inode)) &&
1629                                         CIFS_CACHE_READ(CIFS_I(inode))) {
1630                         cifs_zap_mapping(inode);
1631                         cifs_dbg(FYI, "Set no oplock for inode=%p due to mand locks\n",
1632                                  inode);
1633                         CIFS_I(inode)->oplock = 0;
1634                 }
1635
1636                 rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length,
1637                                             type, 1, 0, wait_flag);
1638                 if (rc) {
1639                         kfree(lock);
1640                         return rc;
1641                 }
1642
1643                 cifs_lock_add(cfile, lock);
1644         } else if (unlock)
1645                 rc = server->ops->mand_unlock_range(cfile, flock, xid);
1646
1647 out:
1648         if (flock->fl_flags & FL_POSIX) {
1649                 /*
1650                  * If this is a request to remove all locks because we
1651                  * are closing the file, it doesn't matter if the
1652                  * unlocking failed as both cifs.ko and the SMB server
1653                  * remove the lock on file close
1654                  */
1655                 if (rc) {
1656                         cifs_dbg(VFS, "%s failed rc=%d\n", __func__, rc);
1657                         if (!(flock->fl_flags & FL_CLOSE))
1658                                 return rc;
1659                 }
1660                 rc = locks_lock_file_wait(file, flock);
1661         }
1662         return rc;
1663 }
1664
1665 int cifs_lock(struct file *file, int cmd, struct file_lock *flock)
1666 {
1667         int rc, xid;
1668         int lock = 0, unlock = 0;
1669         bool wait_flag = false;
1670         bool posix_lck = false;
1671         struct cifs_sb_info *cifs_sb;
1672         struct cifs_tcon *tcon;
1673         struct cifsInodeInfo *cinode;
1674         struct cifsFileInfo *cfile;
1675         __u16 netfid;
1676         __u32 type;
1677
1678         rc = -EACCES;
1679         xid = get_xid();
1680
1681         cifs_dbg(FYI, "Lock parm: 0x%x flockflags: 0x%x flocktype: 0x%x start: %lld end: %lld\n",
1682                  cmd, flock->fl_flags, flock->fl_type,
1683                  flock->fl_start, flock->fl_end);
1684
1685         cfile = (struct cifsFileInfo *)file->private_data;
1686         tcon = tlink_tcon(cfile->tlink);
1687
1688         cifs_read_flock(flock, &type, &lock, &unlock, &wait_flag,
1689                         tcon->ses->server);
1690         cifs_sb = CIFS_FILE_SB(file);
1691         netfid = cfile->fid.netfid;
1692         cinode = CIFS_I(file_inode(file));
1693
1694         if (cap_unix(tcon->ses) &&
1695             (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
1696             ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
1697                 posix_lck = true;
1698         /*
1699          * BB add code here to normalize offset and length to account for
1700          * negative length which we can not accept over the wire.
1701          */
1702         if (IS_GETLK(cmd)) {
1703                 rc = cifs_getlk(file, flock, type, wait_flag, posix_lck, xid);
1704                 free_xid(xid);
1705                 return rc;
1706         }
1707
1708         if (!lock && !unlock) {
1709                 /*
1710                  * if no lock or unlock then nothing to do since we do not
1711                  * know what it is
1712                  */
1713                 free_xid(xid);
1714                 return -EOPNOTSUPP;
1715         }
1716
1717         rc = cifs_setlk(file, flock, type, wait_flag, posix_lck, lock, unlock,
1718                         xid);
1719         free_xid(xid);
1720         return rc;
1721 }
1722
1723 /*
1724  * update the file size (if needed) after a write. Should be called with
1725  * the inode->i_lock held
1726  */
1727 void
1728 cifs_update_eof(struct cifsInodeInfo *cifsi, loff_t offset,
1729                       unsigned int bytes_written)
1730 {
1731         loff_t end_of_write = offset + bytes_written;
1732
1733         if (end_of_write > cifsi->server_eof)
1734                 cifsi->server_eof = end_of_write;
1735 }
1736
1737 static ssize_t
1738 cifs_write(struct cifsFileInfo *open_file, __u32 pid, const char *write_data,
1739            size_t write_size, loff_t *offset)
1740 {
1741         int rc = 0;
1742         unsigned int bytes_written = 0;
1743         unsigned int total_written;
1744         struct cifs_sb_info *cifs_sb;
1745         struct cifs_tcon *tcon;
1746         struct TCP_Server_Info *server;
1747         unsigned int xid;
1748         struct dentry *dentry = open_file->dentry;
1749         struct cifsInodeInfo *cifsi = CIFS_I(d_inode(dentry));
1750         struct cifs_io_parms io_parms;
1751
1752         cifs_sb = CIFS_SB(dentry->d_sb);
1753
1754         cifs_dbg(FYI, "write %zd bytes to offset %lld of %pd\n",
1755                  write_size, *offset, dentry);
1756
1757         tcon = tlink_tcon(open_file->tlink);
1758         server = tcon->ses->server;
1759
1760         if (!server->ops->sync_write)
1761                 return -ENOSYS;
1762
1763         xid = get_xid();
1764
1765         for (total_written = 0; write_size > total_written;
1766              total_written += bytes_written) {
1767                 rc = -EAGAIN;
1768                 while (rc == -EAGAIN) {
1769                         struct kvec iov[2];
1770                         unsigned int len;
1771
1772                         if (open_file->invalidHandle) {
1773                                 /* we could deadlock if we called
1774                                    filemap_fdatawait from here so tell
1775                                    reopen_file not to flush data to
1776                                    server now */
1777                                 rc = cifs_reopen_file(open_file, false);
1778                                 if (rc != 0)
1779                                         break;
1780                         }
1781
1782                         len = min(server->ops->wp_retry_size(d_inode(dentry)),
1783                                   (unsigned int)write_size - total_written);
1784                         /* iov[0] is reserved for smb header */
1785                         iov[1].iov_base = (char *)write_data + total_written;
1786                         iov[1].iov_len = len;
1787                         io_parms.pid = pid;
1788                         io_parms.tcon = tcon;
1789                         io_parms.offset = *offset;
1790                         io_parms.length = len;
1791                         rc = server->ops->sync_write(xid, &open_file->fid,
1792                                         &io_parms, &bytes_written, iov, 1);
1793                 }
1794                 if (rc || (bytes_written == 0)) {
1795                         if (total_written)
1796                                 break;
1797                         else {
1798                                 free_xid(xid);
1799                                 return rc;
1800                         }
1801                 } else {
1802                         spin_lock(&d_inode(dentry)->i_lock);
1803                         cifs_update_eof(cifsi, *offset, bytes_written);
1804                         spin_unlock(&d_inode(dentry)->i_lock);
1805                         *offset += bytes_written;
1806                 }
1807         }
1808
1809         cifs_stats_bytes_written(tcon, total_written);
1810
1811         if (total_written > 0) {
1812                 spin_lock(&d_inode(dentry)->i_lock);
1813                 if (*offset > d_inode(dentry)->i_size)
1814                         i_size_write(d_inode(dentry), *offset);
1815                 spin_unlock(&d_inode(dentry)->i_lock);
1816         }
1817         mark_inode_dirty_sync(d_inode(dentry));
1818         free_xid(xid);
1819         return total_written;
1820 }
1821
1822 struct cifsFileInfo *find_readable_file(struct cifsInodeInfo *cifs_inode,
1823                                         bool fsuid_only)
1824 {
1825         struct cifsFileInfo *open_file = NULL;
1826         struct cifs_sb_info *cifs_sb = CIFS_SB(cifs_inode->vfs_inode.i_sb);
1827         struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
1828
1829         /* only filter by fsuid on multiuser mounts */
1830         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
1831                 fsuid_only = false;
1832
1833         spin_lock(&tcon->open_file_lock);
1834         /* we could simply get the first_list_entry since write-only entries
1835            are always at the end of the list but since the first entry might
1836            have a close pending, we go through the whole list */
1837         list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
1838                 if (fsuid_only && !uid_eq(open_file->uid, current_fsuid()))
1839                         continue;
1840                 if (OPEN_FMODE(open_file->f_flags) & FMODE_READ) {
1841                         if (!open_file->invalidHandle) {
1842                                 /* found a good file */
1843                                 /* lock it so it will not be closed on us */
1844                                 cifsFileInfo_get(open_file);
1845                                 spin_unlock(&tcon->open_file_lock);
1846                                 return open_file;
1847                         } /* else might as well continue, and look for
1848                              another, or simply have the caller reopen it
1849                              again rather than trying to fix this handle */
1850                 } else /* write only file */
1851                         break; /* write only files are last so must be done */
1852         }
1853         spin_unlock(&tcon->open_file_lock);
1854         return NULL;
1855 }
1856
1857 /* Return -EBADF if no handle is found and general rc otherwise */
1858 int
1859 cifs_get_writable_file(struct cifsInodeInfo *cifs_inode, bool fsuid_only,
1860                        struct cifsFileInfo **ret_file)
1861 {
1862         struct cifsFileInfo *open_file, *inv_file = NULL;
1863         struct cifs_sb_info *cifs_sb;
1864         struct cifs_tcon *tcon;
1865         bool any_available = false;
1866         int rc = -EBADF;
1867         unsigned int refind = 0;
1868
1869         *ret_file = NULL;
1870
1871         /*
1872          * Having a null inode here (because mapping->host was set to zero by
1873          * the VFS or MM) should not happen but we had reports of on oops (due
1874          * to it being zero) during stress testcases so we need to check for it
1875          */
1876
1877         if (cifs_inode == NULL) {
1878                 cifs_dbg(VFS, "Null inode passed to cifs_writeable_file\n");
1879                 dump_stack();
1880                 return rc;
1881         }
1882
1883         cifs_sb = CIFS_SB(cifs_inode->vfs_inode.i_sb);
1884         tcon = cifs_sb_master_tcon(cifs_sb);
1885
1886         /* only filter by fsuid on multiuser mounts */
1887         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
1888                 fsuid_only = false;
1889
1890         spin_lock(&tcon->open_file_lock);
1891 refind_writable:
1892         if (refind > MAX_REOPEN_ATT) {
1893                 spin_unlock(&tcon->open_file_lock);
1894                 return rc;
1895         }
1896         list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
1897                 if (!any_available && open_file->pid != current->tgid)
1898                         continue;
1899                 if (fsuid_only && !uid_eq(open_file->uid, current_fsuid()))
1900                         continue;
1901                 if (OPEN_FMODE(open_file->f_flags) & FMODE_WRITE) {
1902                         if (!open_file->invalidHandle) {
1903                                 /* found a good writable file */
1904                                 cifsFileInfo_get(open_file);
1905                                 spin_unlock(&tcon->open_file_lock);
1906                                 *ret_file = open_file;
1907                                 return 0;
1908                         } else {
1909                                 if (!inv_file)
1910                                         inv_file = open_file;
1911                         }
1912                 }
1913         }
1914         /* couldn't find useable FH with same pid, try any available */
1915         if (!any_available) {
1916                 any_available = true;
1917                 goto refind_writable;
1918         }
1919
1920         if (inv_file) {
1921                 any_available = false;
1922                 cifsFileInfo_get(inv_file);
1923         }
1924
1925         spin_unlock(&tcon->open_file_lock);
1926
1927         if (inv_file) {
1928                 rc = cifs_reopen_file(inv_file, false);
1929                 if (!rc) {
1930                         *ret_file = inv_file;
1931                         return 0;
1932                 }
1933
1934                 spin_lock(&tcon->open_file_lock);
1935                 list_move_tail(&inv_file->flist, &cifs_inode->openFileList);
1936                 spin_unlock(&tcon->open_file_lock);
1937                 cifsFileInfo_put(inv_file);
1938                 ++refind;
1939                 inv_file = NULL;
1940                 spin_lock(&tcon->open_file_lock);
1941                 goto refind_writable;
1942         }
1943
1944         return rc;
1945 }
1946
1947 struct cifsFileInfo *
1948 find_writable_file(struct cifsInodeInfo *cifs_inode, bool fsuid_only)
1949 {
1950         struct cifsFileInfo *cfile;
1951         int rc;
1952
1953         rc = cifs_get_writable_file(cifs_inode, fsuid_only, &cfile);
1954         if (rc)
1955                 cifs_dbg(FYI, "couldn't find writable handle rc=%d", rc);
1956
1957         return cfile;
1958 }
1959
1960 static int cifs_partialpagewrite(struct page *page, unsigned from, unsigned to)
1961 {
1962         struct address_space *mapping = page->mapping;
1963         loff_t offset = (loff_t)page->index << PAGE_SHIFT;
1964         char *write_data;
1965         int rc = -EFAULT;
1966         int bytes_written = 0;
1967         struct inode *inode;
1968         struct cifsFileInfo *open_file;
1969
1970         if (!mapping || !mapping->host)
1971                 return -EFAULT;
1972
1973         inode = page->mapping->host;
1974
1975         offset += (loff_t)from;
1976         write_data = kmap(page);
1977         write_data += from;
1978
1979         if ((to > PAGE_SIZE) || (from > to)) {
1980                 kunmap(page);
1981                 return -EIO;
1982         }
1983
1984         /* racing with truncate? */
1985         if (offset > mapping->host->i_size) {
1986                 kunmap(page);
1987                 return 0; /* don't care */
1988         }
1989
1990         /* check to make sure that we are not extending the file */
1991         if (mapping->host->i_size - offset < (loff_t)to)
1992                 to = (unsigned)(mapping->host->i_size - offset);
1993
1994         rc = cifs_get_writable_file(CIFS_I(mapping->host), false, &open_file);
1995         if (!rc) {
1996                 bytes_written = cifs_write(open_file, open_file->pid,
1997                                            write_data, to - from, &offset);
1998                 cifsFileInfo_put(open_file);
1999                 /* Does mm or vfs already set times? */
2000                 inode->i_atime = inode->i_mtime = current_time(inode);
2001                 if ((bytes_written > 0) && (offset))
2002                         rc = 0;
2003                 else if (bytes_written < 0)
2004                         rc = bytes_written;
2005                 else
2006                         rc = -EFAULT;
2007         } else {
2008                 cifs_dbg(FYI, "No writable handle for write page rc=%d\n", rc);
2009                 if (!is_retryable_error(rc))
2010                         rc = -EIO;
2011         }
2012
2013         kunmap(page);
2014         return rc;
2015 }
2016
2017 static struct cifs_writedata *
2018 wdata_alloc_and_fillpages(pgoff_t tofind, struct address_space *mapping,
2019                           pgoff_t end, pgoff_t *index,
2020                           unsigned int *found_pages)
2021 {
2022         struct cifs_writedata *wdata;
2023
2024         wdata = cifs_writedata_alloc((unsigned int)tofind,
2025                                      cifs_writev_complete);
2026         if (!wdata)
2027                 return NULL;
2028
2029         *found_pages = find_get_pages_range_tag(mapping, index, end,
2030                                 PAGECACHE_TAG_DIRTY, tofind, wdata->pages);
2031         return wdata;
2032 }
2033
2034 static unsigned int
2035 wdata_prepare_pages(struct cifs_writedata *wdata, unsigned int found_pages,
2036                     struct address_space *mapping,
2037                     struct writeback_control *wbc,
2038                     pgoff_t end, pgoff_t *index, pgoff_t *next, bool *done)
2039 {
2040         unsigned int nr_pages = 0, i;
2041         struct page *page;
2042
2043         for (i = 0; i < found_pages; i++) {
2044                 page = wdata->pages[i];
2045                 /*
2046                  * At this point we hold neither the i_pages lock nor the
2047                  * page lock: the page may be truncated or invalidated
2048                  * (changing page->mapping to NULL), or even swizzled
2049                  * back from swapper_space to tmpfs file mapping
2050                  */
2051
2052                 if (nr_pages == 0)
2053                         lock_page(page);
2054                 else if (!trylock_page(page))
2055                         break;
2056
2057                 if (unlikely(page->mapping != mapping)) {
2058                         unlock_page(page);
2059                         break;
2060                 }
2061
2062                 if (!wbc->range_cyclic && page->index > end) {
2063                         *done = true;
2064                         unlock_page(page);
2065                         break;
2066                 }
2067
2068                 if (*next && (page->index != *next)) {
2069                         /* Not next consecutive page */
2070                         unlock_page(page);
2071                         break;
2072                 }
2073
2074                 if (wbc->sync_mode != WB_SYNC_NONE)
2075                         wait_on_page_writeback(page);
2076
2077                 if (PageWriteback(page) ||
2078                                 !clear_page_dirty_for_io(page)) {
2079                         unlock_page(page);
2080                         break;
2081                 }
2082
2083                 /*
2084                  * This actually clears the dirty bit in the radix tree.
2085                  * See cifs_writepage() for more commentary.
2086                  */
2087                 set_page_writeback(page);
2088                 if (page_offset(page) >= i_size_read(mapping->host)) {
2089                         *done = true;
2090                         unlock_page(page);
2091                         end_page_writeback(page);
2092                         break;
2093                 }
2094
2095                 wdata->pages[i] = page;
2096                 *next = page->index + 1;
2097                 ++nr_pages;
2098         }
2099
2100         /* reset index to refind any pages skipped */
2101         if (nr_pages == 0)
2102                 *index = wdata->pages[0]->index + 1;
2103
2104         /* put any pages we aren't going to use */
2105         for (i = nr_pages; i < found_pages; i++) {
2106                 put_page(wdata->pages[i]);
2107                 wdata->pages[i] = NULL;
2108         }
2109
2110         return nr_pages;
2111 }
2112
2113 static int
2114 wdata_send_pages(struct cifs_writedata *wdata, unsigned int nr_pages,
2115                  struct address_space *mapping, struct writeback_control *wbc)
2116 {
2117         int rc;
2118         struct TCP_Server_Info *server =
2119                                 tlink_tcon(wdata->cfile->tlink)->ses->server;
2120
2121         wdata->sync_mode = wbc->sync_mode;
2122         wdata->nr_pages = nr_pages;
2123         wdata->offset = page_offset(wdata->pages[0]);
2124         wdata->pagesz = PAGE_SIZE;
2125         wdata->tailsz = min(i_size_read(mapping->host) -
2126                         page_offset(wdata->pages[nr_pages - 1]),
2127                         (loff_t)PAGE_SIZE);
2128         wdata->bytes = ((nr_pages - 1) * PAGE_SIZE) + wdata->tailsz;
2129         wdata->pid = wdata->cfile->pid;
2130
2131         rc = adjust_credits(server, &wdata->credits, wdata->bytes);
2132         if (rc)
2133                 return rc;
2134
2135         if (wdata->cfile->invalidHandle)
2136                 rc = -EAGAIN;
2137         else
2138                 rc = server->ops->async_writev(wdata, cifs_writedata_release);
2139
2140         return rc;
2141 }
2142
2143 static int cifs_writepages(struct address_space *mapping,
2144                            struct writeback_control *wbc)
2145 {
2146         struct inode *inode = mapping->host;
2147         struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
2148         struct TCP_Server_Info *server;
2149         bool done = false, scanned = false, range_whole = false;
2150         pgoff_t end, index;
2151         struct cifs_writedata *wdata;
2152         struct cifsFileInfo *cfile = NULL;
2153         int rc = 0;
2154         int saved_rc = 0;
2155         unsigned int xid;
2156
2157         /*
2158          * If wsize is smaller than the page cache size, default to writing
2159          * one page at a time via cifs_writepage
2160          */
2161         if (cifs_sb->wsize < PAGE_SIZE)
2162                 return generic_writepages(mapping, wbc);
2163
2164         xid = get_xid();
2165         if (wbc->range_cyclic) {
2166                 index = mapping->writeback_index; /* Start from prev offset */
2167                 end = -1;
2168         } else {
2169                 index = wbc->range_start >> PAGE_SHIFT;
2170                 end = wbc->range_end >> PAGE_SHIFT;
2171                 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
2172                         range_whole = true;
2173                 scanned = true;
2174         }
2175         server = cifs_sb_master_tcon(cifs_sb)->ses->server;
2176 retry:
2177         while (!done && index <= end) {
2178                 unsigned int i, nr_pages, found_pages, wsize;
2179                 pgoff_t next = 0, tofind, saved_index = index;
2180                 struct cifs_credits credits_on_stack;
2181                 struct cifs_credits *credits = &credits_on_stack;
2182                 int get_file_rc = 0;
2183
2184                 if (cfile)
2185                         cifsFileInfo_put(cfile);
2186
2187                 rc = cifs_get_writable_file(CIFS_I(inode), false, &cfile);
2188
2189                 /* in case of an error store it to return later */
2190                 if (rc)
2191                         get_file_rc = rc;
2192
2193                 rc = server->ops->wait_mtu_credits(server, cifs_sb->wsize,
2194                                                    &wsize, credits);
2195                 if (rc != 0) {
2196                         done = true;
2197                         break;
2198                 }
2199
2200                 tofind = min((wsize / PAGE_SIZE) - 1, end - index) + 1;
2201
2202                 wdata = wdata_alloc_and_fillpages(tofind, mapping, end, &index,
2203                                                   &found_pages);
2204                 if (!wdata) {
2205                         rc = -ENOMEM;
2206                         done = true;
2207                         add_credits_and_wake_if(server, credits, 0);
2208                         break;
2209                 }
2210
2211                 if (found_pages == 0) {
2212                         kref_put(&wdata->refcount, cifs_writedata_release);
2213                         add_credits_and_wake_if(server, credits, 0);
2214                         break;
2215                 }
2216
2217                 nr_pages = wdata_prepare_pages(wdata, found_pages, mapping, wbc,
2218                                                end, &index, &next, &done);
2219
2220                 /* nothing to write? */
2221                 if (nr_pages == 0) {
2222                         kref_put(&wdata->refcount, cifs_writedata_release);
2223                         add_credits_and_wake_if(server, credits, 0);
2224                         continue;
2225                 }
2226
2227                 wdata->credits = credits_on_stack;
2228                 wdata->cfile = cfile;
2229                 cfile = NULL;
2230
2231                 if (!wdata->cfile) {
2232                         cifs_dbg(VFS, "No writable handle in writepages rc=%d\n",
2233                                  get_file_rc);
2234                         if (is_retryable_error(get_file_rc))
2235                                 rc = get_file_rc;
2236                         else
2237                                 rc = -EBADF;
2238                 } else
2239                         rc = wdata_send_pages(wdata, nr_pages, mapping, wbc);
2240
2241                 for (i = 0; i < nr_pages; ++i)
2242                         unlock_page(wdata->pages[i]);
2243
2244                 /* send failure -- clean up the mess */
2245                 if (rc != 0) {
2246                         add_credits_and_wake_if(server, &wdata->credits, 0);
2247                         for (i = 0; i < nr_pages; ++i) {
2248                                 if (is_retryable_error(rc))
2249                                         redirty_page_for_writepage(wbc,
2250                                                            wdata->pages[i]);
2251                                 else
2252                                         SetPageError(wdata->pages[i]);
2253                                 end_page_writeback(wdata->pages[i]);
2254                                 put_page(wdata->pages[i]);
2255                         }
2256                         if (!is_retryable_error(rc))
2257                                 mapping_set_error(mapping, rc);
2258                 }
2259                 kref_put(&wdata->refcount, cifs_writedata_release);
2260
2261                 if (wbc->sync_mode == WB_SYNC_ALL && rc == -EAGAIN) {
2262                         index = saved_index;
2263                         continue;
2264                 }
2265
2266                 /* Return immediately if we received a signal during writing */
2267                 if (is_interrupt_error(rc)) {
2268                         done = true;
2269                         break;
2270                 }
2271
2272                 if (rc != 0 && saved_rc == 0)
2273                         saved_rc = rc;
2274
2275                 wbc->nr_to_write -= nr_pages;
2276                 if (wbc->nr_to_write <= 0)
2277                         done = true;
2278
2279                 index = next;
2280         }
2281
2282         if (!scanned && !done) {
2283                 /*
2284                  * We hit the last page and there is more work to be done: wrap
2285                  * back to the start of the file
2286                  */
2287                 scanned = true;
2288                 index = 0;
2289                 goto retry;
2290         }
2291
2292         if (saved_rc != 0)
2293                 rc = saved_rc;
2294
2295         if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
2296                 mapping->writeback_index = index;
2297
2298         if (cfile)
2299                 cifsFileInfo_put(cfile);
2300         free_xid(xid);
2301         return rc;
2302 }
2303
2304 static int
2305 cifs_writepage_locked(struct page *page, struct writeback_control *wbc)
2306 {
2307         int rc;
2308         unsigned int xid;
2309
2310         xid = get_xid();
2311 /* BB add check for wbc flags */
2312         get_page(page);
2313         if (!PageUptodate(page))
2314                 cifs_dbg(FYI, "ppw - page not up to date\n");
2315
2316         /*
2317          * Set the "writeback" flag, and clear "dirty" in the radix tree.
2318          *
2319          * A writepage() implementation always needs to do either this,
2320          * or re-dirty the page with "redirty_page_for_writepage()" in
2321          * the case of a failure.
2322          *
2323          * Just unlocking the page will cause the radix tree tag-bits
2324          * to fail to update with the state of the page correctly.
2325          */
2326         set_page_writeback(page);
2327 retry_write:
2328         rc = cifs_partialpagewrite(page, 0, PAGE_SIZE);
2329         if (is_retryable_error(rc)) {
2330                 if (wbc->sync_mode == WB_SYNC_ALL && rc == -EAGAIN)
2331                         goto retry_write;
2332                 redirty_page_for_writepage(wbc, page);
2333         } else if (rc != 0) {
2334                 SetPageError(page);
2335                 mapping_set_error(page->mapping, rc);
2336         } else {
2337                 SetPageUptodate(page);
2338         }
2339         end_page_writeback(page);
2340         put_page(page);
2341         free_xid(xid);
2342         return rc;
2343 }
2344
2345 static int cifs_writepage(struct page *page, struct writeback_control *wbc)
2346 {
2347         int rc = cifs_writepage_locked(page, wbc);
2348         unlock_page(page);
2349         return rc;
2350 }
2351
2352 static int cifs_write_end(struct file *file, struct address_space *mapping,
2353                         loff_t pos, unsigned len, unsigned copied,
2354                         struct page *page, void *fsdata)
2355 {
2356         int rc;
2357         struct inode *inode = mapping->host;
2358         struct cifsFileInfo *cfile = file->private_data;
2359         struct cifs_sb_info *cifs_sb = CIFS_SB(cfile->dentry->d_sb);
2360         __u32 pid;
2361
2362         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
2363                 pid = cfile->pid;
2364         else
2365                 pid = current->tgid;
2366
2367         cifs_dbg(FYI, "write_end for page %p from pos %lld with %d bytes\n",
2368                  page, pos, copied);
2369
2370         if (PageChecked(page)) {
2371                 if (copied == len)
2372                         SetPageUptodate(page);
2373                 ClearPageChecked(page);
2374         } else if (!PageUptodate(page) && copied == PAGE_SIZE)
2375                 SetPageUptodate(page);
2376
2377         if (!PageUptodate(page)) {
2378                 char *page_data;
2379                 unsigned offset = pos & (PAGE_SIZE - 1);
2380                 unsigned int xid;
2381
2382                 xid = get_xid();
2383                 /* this is probably better than directly calling
2384                    partialpage_write since in this function the file handle is
2385                    known which we might as well leverage */
2386                 /* BB check if anything else missing out of ppw
2387                    such as updating last write time */
2388                 page_data = kmap(page);
2389                 rc = cifs_write(cfile, pid, page_data + offset, copied, &pos);
2390                 /* if (rc < 0) should we set writebehind rc? */
2391                 kunmap(page);
2392
2393                 free_xid(xid);
2394         } else {
2395                 rc = copied;
2396                 pos += copied;
2397                 set_page_dirty(page);
2398         }
2399
2400         if (rc > 0) {
2401                 spin_lock(&inode->i_lock);
2402                 if (pos > inode->i_size)
2403                         i_size_write(inode, pos);
2404                 spin_unlock(&inode->i_lock);
2405         }
2406
2407         unlock_page(page);
2408         put_page(page);
2409
2410         return rc;
2411 }
2412
2413 int cifs_strict_fsync(struct file *file, loff_t start, loff_t end,
2414                       int datasync)
2415 {
2416         unsigned int xid;
2417         int rc = 0;
2418         struct cifs_tcon *tcon;
2419         struct TCP_Server_Info *server;
2420         struct cifsFileInfo *smbfile = file->private_data;
2421         struct inode *inode = file_inode(file);
2422         struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
2423
2424         rc = file_write_and_wait_range(file, start, end);
2425         if (rc)
2426                 return rc;
2427         inode_lock(inode);
2428
2429         xid = get_xid();
2430
2431         cifs_dbg(FYI, "Sync file - name: %pD datasync: 0x%x\n",
2432                  file, datasync);
2433
2434         if (!CIFS_CACHE_READ(CIFS_I(inode))) {
2435                 rc = cifs_zap_mapping(inode);
2436                 if (rc) {
2437                         cifs_dbg(FYI, "rc: %d during invalidate phase\n", rc);
2438                         rc = 0; /* don't care about it in fsync */
2439                 }
2440         }
2441
2442         tcon = tlink_tcon(smbfile->tlink);
2443         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC)) {
2444                 server = tcon->ses->server;
2445                 if (server->ops->flush)
2446                         rc = server->ops->flush(xid, tcon, &smbfile->fid);
2447                 else
2448                         rc = -ENOSYS;
2449         }
2450
2451         free_xid(xid);
2452         inode_unlock(inode);
2453         return rc;
2454 }
2455
2456 int cifs_fsync(struct file *file, loff_t start, loff_t end, int datasync)
2457 {
2458         unsigned int xid;
2459         int rc = 0;
2460         struct cifs_tcon *tcon;
2461         struct TCP_Server_Info *server;
2462         struct cifsFileInfo *smbfile = file->private_data;
2463         struct cifs_sb_info *cifs_sb = CIFS_FILE_SB(file);
2464         struct inode *inode = file->f_mapping->host;
2465
2466         rc = file_write_and_wait_range(file, start, end);
2467         if (rc)
2468                 return rc;
2469         inode_lock(inode);
2470
2471         xid = get_xid();
2472
2473         cifs_dbg(FYI, "Sync file - name: %pD datasync: 0x%x\n",
2474                  file, datasync);
2475
2476         tcon = tlink_tcon(smbfile->tlink);
2477         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC)) {
2478                 server = tcon->ses->server;
2479                 if (server->ops->flush)
2480                         rc = server->ops->flush(xid, tcon, &smbfile->fid);
2481                 else
2482                         rc = -ENOSYS;
2483         }
2484
2485         free_xid(xid);
2486         inode_unlock(inode);
2487         return rc;
2488 }
2489
2490 /*
2491  * As file closes, flush all cached write data for this inode checking
2492  * for write behind errors.
2493  */
2494 int cifs_flush(struct file *file, fl_owner_t id)
2495 {
2496         struct inode *inode = file_inode(file);
2497         int rc = 0;
2498
2499         if (file->f_mode & FMODE_WRITE)
2500                 rc = filemap_write_and_wait(inode->i_mapping);
2501
2502         cifs_dbg(FYI, "Flush inode %p file %p rc %d\n", inode, file, rc);
2503
2504         return rc;
2505 }
2506
2507 static int
2508 cifs_write_allocate_pages(struct page **pages, unsigned long num_pages)
2509 {
2510         int rc = 0;
2511         unsigned long i;
2512
2513         for (i = 0; i < num_pages; i++) {
2514                 pages[i] = alloc_page(GFP_KERNEL|__GFP_HIGHMEM);
2515                 if (!pages[i]) {
2516                         /*
2517                          * save number of pages we have already allocated and
2518                          * return with ENOMEM error
2519                          */
2520                         num_pages = i;
2521                         rc = -ENOMEM;
2522                         break;
2523                 }
2524         }
2525
2526         if (rc) {
2527                 for (i = 0; i < num_pages; i++)
2528                         put_page(pages[i]);
2529         }
2530         return rc;
2531 }
2532
2533 static inline
2534 size_t get_numpages(const size_t wsize, const size_t len, size_t *cur_len)
2535 {
2536         size_t num_pages;
2537         size_t clen;
2538
2539         clen = min_t(const size_t, len, wsize);
2540         num_pages = DIV_ROUND_UP(clen, PAGE_SIZE);
2541
2542         if (cur_len)
2543                 *cur_len = clen;
2544
2545         return num_pages;
2546 }
2547
2548 static void
2549 cifs_uncached_writedata_release(struct kref *refcount)
2550 {
2551         int i;
2552         struct cifs_writedata *wdata = container_of(refcount,
2553                                         struct cifs_writedata, refcount);
2554
2555         kref_put(&wdata->ctx->refcount, cifs_aio_ctx_release);
2556         for (i = 0; i < wdata->nr_pages; i++)
2557                 put_page(wdata->pages[i]);
2558         cifs_writedata_release(refcount);
2559 }
2560
2561 static void collect_uncached_write_data(struct cifs_aio_ctx *ctx);
2562
2563 static void
2564 cifs_uncached_writev_complete(struct work_struct *work)
2565 {
2566         struct cifs_writedata *wdata = container_of(work,
2567                                         struct cifs_writedata, work);
2568         struct inode *inode = d_inode(wdata->cfile->dentry);
2569         struct cifsInodeInfo *cifsi = CIFS_I(inode);
2570
2571         spin_lock(&inode->i_lock);
2572         cifs_update_eof(cifsi, wdata->offset, wdata->bytes);
2573         if (cifsi->server_eof > inode->i_size)
2574                 i_size_write(inode, cifsi->server_eof);
2575         spin_unlock(&inode->i_lock);
2576
2577         complete(&wdata->done);
2578         collect_uncached_write_data(wdata->ctx);
2579         /* the below call can possibly free the last ref to aio ctx */
2580         kref_put(&wdata->refcount, cifs_uncached_writedata_release);
2581 }
2582
2583 static int
2584 wdata_fill_from_iovec(struct cifs_writedata *wdata, struct iov_iter *from,
2585                       size_t *len, unsigned long *num_pages)
2586 {
2587         size_t save_len, copied, bytes, cur_len = *len;
2588         unsigned long i, nr_pages = *num_pages;
2589
2590         save_len = cur_len;
2591         for (i = 0; i < nr_pages; i++) {
2592                 bytes = min_t(const size_t, cur_len, PAGE_SIZE);
2593                 copied = copy_page_from_iter(wdata->pages[i], 0, bytes, from);
2594                 cur_len -= copied;
2595                 /*
2596                  * If we didn't copy as much as we expected, then that
2597                  * may mean we trod into an unmapped area. Stop copying
2598                  * at that point. On the next pass through the big
2599                  * loop, we'll likely end up getting a zero-length
2600                  * write and bailing out of it.
2601                  */
2602                 if (copied < bytes)
2603                         break;
2604         }
2605         cur_len = save_len - cur_len;
2606         *len = cur_len;
2607
2608         /*
2609          * If we have no data to send, then that probably means that
2610          * the copy above failed altogether. That's most likely because
2611          * the address in the iovec was bogus. Return -EFAULT and let
2612          * the caller free anything we allocated and bail out.
2613          */
2614         if (!cur_len)
2615                 return -EFAULT;
2616
2617         /*
2618          * i + 1 now represents the number of pages we actually used in
2619          * the copy phase above.
2620          */
2621         *num_pages = i + 1;
2622         return 0;
2623 }
2624
2625 static int
2626 cifs_resend_wdata(struct cifs_writedata *wdata, struct list_head *wdata_list,
2627         struct cifs_aio_ctx *ctx)
2628 {
2629         unsigned int wsize;
2630         struct cifs_credits credits;
2631         int rc;
2632         struct TCP_Server_Info *server =
2633                 tlink_tcon(wdata->cfile->tlink)->ses->server;
2634
2635         /*
2636          * Wait for credits to resend this wdata.
2637          * Note: we are attempting to resend the whole wdata not in segments
2638          */
2639         do {
2640                 rc = server->ops->wait_mtu_credits(server, wdata->bytes, &wsize,
2641                                                    &credits);
2642
2643                 if (rc)
2644                         goto out;
2645
2646                 if (wsize < wdata->bytes) {
2647                         add_credits_and_wake_if(server, &credits, 0);
2648                         msleep(1000);
2649                 }
2650         } while (wsize < wdata->bytes);
2651
2652         wdata->credits = credits;
2653         rc = -EAGAIN;
2654         while (rc == -EAGAIN) {
2655                 rc = 0;
2656                 if (wdata->cfile->invalidHandle)
2657                         rc = cifs_reopen_file(wdata->cfile, false);
2658                 if (!rc)
2659                         rc = server->ops->async_writev(wdata,
2660                                         cifs_uncached_writedata_release);
2661         }
2662
2663         if (!rc) {
2664                 list_add_tail(&wdata->list, wdata_list);
2665                 return 0;
2666         }
2667
2668         add_credits_and_wake_if(server, &wdata->credits, 0);
2669 out:
2670         kref_put(&wdata->refcount, cifs_uncached_writedata_release);
2671
2672         return rc;
2673 }
2674
2675 static int
2676 cifs_write_from_iter(loff_t offset, size_t len, struct iov_iter *from,
2677                      struct cifsFileInfo *open_file,
2678                      struct cifs_sb_info *cifs_sb, struct list_head *wdata_list,
2679                      struct cifs_aio_ctx *ctx)
2680 {
2681         int rc = 0;
2682         size_t cur_len;
2683         unsigned long nr_pages, num_pages, i;
2684         struct cifs_writedata *wdata;
2685         struct iov_iter saved_from = *from;
2686         loff_t saved_offset = offset;
2687         pid_t pid;
2688         struct TCP_Server_Info *server;
2689         struct page **pagevec;
2690         size_t start;
2691         unsigned int xid;
2692
2693         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
2694                 pid = open_file->pid;
2695         else
2696                 pid = current->tgid;
2697
2698         server = tlink_tcon(open_file->tlink)->ses->server;
2699         xid = get_xid();
2700
2701         do {
2702                 unsigned int wsize;
2703                 struct cifs_credits credits_on_stack;
2704                 struct cifs_credits *credits = &credits_on_stack;
2705
2706                 if (open_file->invalidHandle) {
2707                         rc = cifs_reopen_file(open_file, false);
2708                         if (rc == -EAGAIN)
2709                                 continue;
2710                         else if (rc)
2711                                 break;
2712                 }
2713
2714                 rc = server->ops->wait_mtu_credits(server, cifs_sb->wsize,
2715                                                    &wsize, credits);
2716                 if (rc)
2717                         break;
2718
2719                 cur_len = min_t(const size_t, len, wsize);
2720
2721                 if (ctx->direct_io) {
2722                         ssize_t result;
2723
2724                         result = iov_iter_get_pages_alloc(
2725                                 from, &pagevec, cur_len, &start);
2726                         if (result < 0) {
2727                                 cifs_dbg(VFS,
2728                                         "direct_writev couldn't get user pages "
2729                                         "(rc=%zd) iter type %d iov_offset %zd "
2730                                         "count %zd\n",
2731                                         result, from->type,
2732                                         from->iov_offset, from->count);
2733                                 dump_stack();
2734
2735                                 rc = result;
2736                                 add_credits_and_wake_if(server, credits, 0);
2737                                 break;
2738                         }
2739                         cur_len = (size_t)result;
2740                         iov_iter_advance(from, cur_len);
2741
2742                         nr_pages =
2743                                 (cur_len + start + PAGE_SIZE - 1) / PAGE_SIZE;
2744
2745                         wdata = cifs_writedata_direct_alloc(pagevec,
2746                                              cifs_uncached_writev_complete);
2747                         if (!wdata) {
2748                                 rc = -ENOMEM;
2749                                 add_credits_and_wake_if(server, credits, 0);
2750                                 break;
2751                         }
2752
2753
2754                         wdata->page_offset = start;
2755                         wdata->tailsz =
2756                                 nr_pages > 1 ?
2757                                         cur_len - (PAGE_SIZE - start) -
2758                                         (nr_pages - 2) * PAGE_SIZE :
2759                                         cur_len;
2760                 } else {
2761                         nr_pages = get_numpages(wsize, len, &cur_len);
2762                         wdata = cifs_writedata_alloc(nr_pages,
2763                                              cifs_uncached_writev_complete);
2764                         if (!wdata) {
2765                                 rc = -ENOMEM;
2766                                 add_credits_and_wake_if(server, credits, 0);
2767                                 break;
2768                         }
2769
2770                         rc = cifs_write_allocate_pages(wdata->pages, nr_pages);
2771                         if (rc) {
2772                                 kvfree(wdata->pages);
2773                                 kfree(wdata);
2774                                 add_credits_and_wake_if(server, credits, 0);
2775                                 break;
2776                         }
2777
2778                         num_pages = nr_pages;
2779                         rc = wdata_fill_from_iovec(
2780                                 wdata, from, &cur_len, &num_pages);
2781                         if (rc) {
2782                                 for (i = 0; i < nr_pages; i++)
2783                                         put_page(wdata->pages[i]);
2784                                 kvfree(wdata->pages);
2785                                 kfree(wdata);
2786                                 add_credits_and_wake_if(server, credits, 0);
2787                                 break;
2788                         }
2789
2790                         /*
2791                          * Bring nr_pages down to the number of pages we
2792                          * actually used, and free any pages that we didn't use.
2793                          */
2794                         for ( ; nr_pages > num_pages; nr_pages--)
2795                                 put_page(wdata->pages[nr_pages - 1]);
2796
2797                         wdata->tailsz = cur_len - ((nr_pages - 1) * PAGE_SIZE);
2798                 }
2799
2800                 wdata->sync_mode = WB_SYNC_ALL;
2801                 wdata->nr_pages = nr_pages;
2802                 wdata->offset = (__u64)offset;
2803                 wdata->cfile = cifsFileInfo_get(open_file);
2804                 wdata->pid = pid;
2805                 wdata->bytes = cur_len;
2806                 wdata->pagesz = PAGE_SIZE;
2807                 wdata->credits = credits_on_stack;
2808                 wdata->ctx = ctx;
2809                 kref_get(&ctx->refcount);
2810
2811                 rc = adjust_credits(server, &wdata->credits, wdata->bytes);
2812
2813                 if (!rc) {
2814                         if (wdata->cfile->invalidHandle)
2815                                 rc = -EAGAIN;
2816                         else
2817                                 rc = server->ops->async_writev(wdata,
2818                                         cifs_uncached_writedata_release);
2819                 }
2820
2821                 if (rc) {
2822                         add_credits_and_wake_if(server, &wdata->credits, 0);
2823                         kref_put(&wdata->refcount,
2824                                  cifs_uncached_writedata_release);
2825                         if (rc == -EAGAIN) {
2826                                 *from = saved_from;
2827                                 iov_iter_advance(from, offset - saved_offset);
2828                                 continue;
2829                         }
2830                         break;
2831                 }
2832
2833                 list_add_tail(&wdata->list, wdata_list);
2834                 offset += cur_len;
2835                 len -= cur_len;
2836         } while (len > 0);
2837
2838         free_xid(xid);
2839         return rc;
2840 }
2841
2842 static void collect_uncached_write_data(struct cifs_aio_ctx *ctx)
2843 {
2844         struct cifs_writedata *wdata, *tmp;
2845         struct cifs_tcon *tcon;
2846         struct cifs_sb_info *cifs_sb;
2847         struct dentry *dentry = ctx->cfile->dentry;
2848         unsigned int i;
2849         int rc;
2850
2851         tcon = tlink_tcon(ctx->cfile->tlink);
2852         cifs_sb = CIFS_SB(dentry->d_sb);
2853
2854         mutex_lock(&ctx->aio_mutex);
2855
2856         if (list_empty(&ctx->list)) {
2857                 mutex_unlock(&ctx->aio_mutex);
2858                 return;
2859         }
2860
2861         rc = ctx->rc;
2862         /*
2863          * Wait for and collect replies for any successful sends in order of
2864          * increasing offset. Once an error is hit, then return without waiting
2865          * for any more replies.
2866          */
2867 restart_loop:
2868         list_for_each_entry_safe(wdata, tmp, &ctx->list, list) {
2869                 if (!rc) {
2870                         if (!try_wait_for_completion(&wdata->done)) {
2871                                 mutex_unlock(&ctx->aio_mutex);
2872                                 return;
2873                         }
2874
2875                         if (wdata->result)
2876                                 rc = wdata->result;
2877                         else
2878                                 ctx->total_len += wdata->bytes;
2879
2880                         /* resend call if it's a retryable error */
2881                         if (rc == -EAGAIN) {
2882                                 struct list_head tmp_list;
2883                                 struct iov_iter tmp_from = ctx->iter;
2884
2885                                 INIT_LIST_HEAD(&tmp_list);
2886                                 list_del_init(&wdata->list);
2887
2888                                 if (ctx->direct_io)
2889                                         rc = cifs_resend_wdata(
2890                                                 wdata, &tmp_list, ctx);
2891                                 else {
2892                                         iov_iter_advance(&tmp_from,
2893                                                  wdata->offset - ctx->pos);
2894
2895                                         rc = cifs_write_from_iter(wdata->offset,
2896                                                 wdata->bytes, &tmp_from,
2897                                                 ctx->cfile, cifs_sb, &tmp_list,
2898                                                 ctx);
2899                                 }
2900
2901                                 list_splice(&tmp_list, &ctx->list);
2902
2903                                 kref_put(&wdata->refcount,
2904                                          cifs_uncached_writedata_release);
2905                                 goto restart_loop;
2906                         }
2907                 }
2908                 list_del_init(&wdata->list);
2909                 kref_put(&wdata->refcount, cifs_uncached_writedata_release);
2910         }
2911
2912         if (!ctx->direct_io)
2913                 for (i = 0; i < ctx->npages; i++)
2914                         put_page(ctx->bv[i].bv_page);
2915
2916         cifs_stats_bytes_written(tcon, ctx->total_len);
2917         set_bit(CIFS_INO_INVALID_MAPPING, &CIFS_I(dentry->d_inode)->flags);
2918
2919         ctx->rc = (rc == 0) ? ctx->total_len : rc;
2920
2921         mutex_unlock(&ctx->aio_mutex);
2922
2923         if (ctx->iocb && ctx->iocb->ki_complete)
2924                 ctx->iocb->ki_complete(ctx->iocb, ctx->rc, 0);
2925         else
2926                 complete(&ctx->done);
2927 }
2928
2929 static ssize_t __cifs_writev(
2930         struct kiocb *iocb, struct iov_iter *from, bool direct)
2931 {
2932         struct file *file = iocb->ki_filp;
2933         ssize_t total_written = 0;
2934         struct cifsFileInfo *cfile;
2935         struct cifs_tcon *tcon;
2936         struct cifs_sb_info *cifs_sb;
2937         struct cifs_aio_ctx *ctx;
2938         struct iov_iter saved_from = *from;
2939         size_t len = iov_iter_count(from);
2940         int rc;
2941
2942         /*
2943          * iov_iter_get_pages_alloc doesn't work with ITER_KVEC.
2944          * In this case, fall back to non-direct write function.
2945          * this could be improved by getting pages directly in ITER_KVEC
2946          */
2947         if (direct && from->type & ITER_KVEC) {
2948                 cifs_dbg(FYI, "use non-direct cifs_writev for kvec I/O\n");
2949                 direct = false;
2950         }
2951
2952         rc = generic_write_checks(iocb, from);
2953         if (rc <= 0)
2954                 return rc;
2955
2956         cifs_sb = CIFS_FILE_SB(file);
2957         cfile = file->private_data;
2958         tcon = tlink_tcon(cfile->tlink);
2959
2960         if (!tcon->ses->server->ops->async_writev)
2961                 return -ENOSYS;
2962
2963         ctx = cifs_aio_ctx_alloc();
2964         if (!ctx)
2965                 return -ENOMEM;
2966
2967         ctx->cfile = cifsFileInfo_get(cfile);
2968
2969         if (!is_sync_kiocb(iocb))
2970                 ctx->iocb = iocb;
2971
2972         ctx->pos = iocb->ki_pos;
2973
2974         if (direct) {
2975                 ctx->direct_io = true;
2976                 ctx->iter = *from;
2977                 ctx->len = len;
2978         } else {
2979                 rc = setup_aio_ctx_iter(ctx, from, WRITE);
2980                 if (rc) {
2981                         kref_put(&ctx->refcount, cifs_aio_ctx_release);
2982                         return rc;
2983                 }
2984         }
2985
2986         /* grab a lock here due to read response handlers can access ctx */
2987         mutex_lock(&ctx->aio_mutex);
2988
2989         rc = cifs_write_from_iter(iocb->ki_pos, ctx->len, &saved_from,
2990                                   cfile, cifs_sb, &ctx->list, ctx);
2991
2992         /*
2993          * If at least one write was successfully sent, then discard any rc
2994          * value from the later writes. If the other write succeeds, then
2995          * we'll end up returning whatever was written. If it fails, then
2996          * we'll get a new rc value from that.
2997          */
2998         if (!list_empty(&ctx->list))
2999                 rc = 0;
3000
3001         mutex_unlock(&ctx->aio_mutex);
3002
3003         if (rc) {
3004                 kref_put(&ctx->refcount, cifs_aio_ctx_release);
3005                 return rc;
3006         }
3007
3008         if (!is_sync_kiocb(iocb)) {
3009                 kref_put(&ctx->refcount, cifs_aio_ctx_release);
3010                 return -EIOCBQUEUED;
3011         }
3012
3013         rc = wait_for_completion_killable(&ctx->done);
3014         if (rc) {
3015                 mutex_lock(&ctx->aio_mutex);
3016                 ctx->rc = rc = -EINTR;
3017                 total_written = ctx->total_len;
3018                 mutex_unlock(&ctx->aio_mutex);
3019         } else {
3020                 rc = ctx->rc;
3021                 total_written = ctx->total_len;
3022         }
3023
3024         kref_put(&ctx->refcount, cifs_aio_ctx_release);
3025
3026         if (unlikely(!total_written))
3027                 return rc;
3028
3029         iocb->ki_pos += total_written;
3030         return total_written;
3031 }
3032
3033 ssize_t cifs_direct_writev(struct kiocb *iocb, struct iov_iter *from)
3034 {
3035         return __cifs_writev(iocb, from, true);
3036 }
3037
3038 ssize_t cifs_user_writev(struct kiocb *iocb, struct iov_iter *from)
3039 {
3040         return __cifs_writev(iocb, from, false);
3041 }
3042
3043 static ssize_t
3044 cifs_writev(struct kiocb *iocb, struct iov_iter *from)
3045 {
3046         struct file *file = iocb->ki_filp;
3047         struct cifsFileInfo *cfile = (struct cifsFileInfo *)file->private_data;
3048         struct inode *inode = file->f_mapping->host;
3049         struct cifsInodeInfo *cinode = CIFS_I(inode);
3050         struct TCP_Server_Info *server = tlink_tcon(cfile->tlink)->ses->server;
3051         ssize_t rc;
3052
3053         inode_lock(inode);
3054         /*
3055          * We need to hold the sem to be sure nobody modifies lock list
3056          * with a brlock that prevents writing.
3057          */
3058         down_read(&cinode->lock_sem);
3059
3060         rc = generic_write_checks(iocb, from);
3061         if (rc <= 0)
3062                 goto out;
3063
3064         if (!cifs_find_lock_conflict(cfile, iocb->ki_pos, iov_iter_count(from),
3065                                      server->vals->exclusive_lock_type, 0,
3066                                      NULL, CIFS_WRITE_OP))
3067                 rc = __generic_file_write_iter(iocb, from);
3068         else
3069                 rc = -EACCES;
3070 out:
3071         up_read(&cinode->lock_sem);
3072         inode_unlock(inode);
3073
3074         if (rc > 0)
3075                 rc = generic_write_sync(iocb, rc);
3076         return rc;
3077 }
3078
3079 ssize_t
3080 cifs_strict_writev(struct kiocb *iocb, struct iov_iter *from)
3081 {
3082         struct inode *inode = file_inode(iocb->ki_filp);
3083         struct cifsInodeInfo *cinode = CIFS_I(inode);
3084         struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
3085         struct cifsFileInfo *cfile = (struct cifsFileInfo *)
3086                                                 iocb->ki_filp->private_data;
3087         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
3088         ssize_t written;
3089
3090         written = cifs_get_writer(cinode);
3091         if (written)
3092                 return written;
3093
3094         if (CIFS_CACHE_WRITE(cinode)) {
3095                 if (cap_unix(tcon->ses) &&
3096                 (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability))
3097                   && ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0)) {
3098                         written = generic_file_write_iter(iocb, from);
3099                         goto out;
3100                 }
3101                 written = cifs_writev(iocb, from);
3102                 goto out;
3103         }
3104         /*
3105          * For non-oplocked files in strict cache mode we need to write the data
3106          * to the server exactly from the pos to pos+len-1 rather than flush all
3107          * affected pages because it may cause a error with mandatory locks on
3108          * these pages but not on the region from pos to ppos+len-1.
3109          */
3110         written = cifs_user_writev(iocb, from);
3111         if (CIFS_CACHE_READ(cinode)) {
3112                 /*
3113                  * We have read level caching and we have just sent a write
3114                  * request to the server thus making data in the cache stale.
3115                  * Zap the cache and set oplock/lease level to NONE to avoid
3116                  * reading stale data from the cache. All subsequent read
3117                  * operations will read new data from the server.
3118                  */
3119                 cifs_zap_mapping(inode);
3120                 cifs_dbg(FYI, "Set Oplock/Lease to NONE for inode=%p after write\n",
3121                          inode);
3122                 cinode->oplock = 0;
3123         }
3124 out:
3125         cifs_put_writer(cinode);
3126         return written;
3127 }
3128
3129 static struct cifs_readdata *
3130 cifs_readdata_direct_alloc(struct page **pages, work_func_t complete)
3131 {
3132         struct cifs_readdata *rdata;
3133
3134         rdata = kzalloc(sizeof(*rdata), GFP_KERNEL);
3135         if (rdata != NULL) {
3136                 rdata->pages = pages;
3137                 kref_init(&rdata->refcount);
3138                 INIT_LIST_HEAD(&rdata->list);
3139                 init_completion(&rdata->done);
3140                 INIT_WORK(&rdata->work, complete);
3141         }
3142
3143         return rdata;
3144 }
3145
3146 static struct cifs_readdata *
3147 cifs_readdata_alloc(unsigned int nr_pages, work_func_t complete)
3148 {
3149         struct page **pages =
3150                 kcalloc(nr_pages, sizeof(struct page *), GFP_KERNEL);
3151         struct cifs_readdata *ret = NULL;
3152
3153         if (pages) {
3154                 ret = cifs_readdata_direct_alloc(pages, complete);
3155                 if (!ret)
3156                         kfree(pages);
3157         }
3158
3159         return ret;
3160 }
3161
3162 void
3163 cifs_readdata_release(struct kref *refcount)
3164 {
3165         struct cifs_readdata *rdata = container_of(refcount,
3166                                         struct cifs_readdata, refcount);
3167 #ifdef CONFIG_CIFS_SMB_DIRECT
3168         if (rdata->mr) {
3169                 smbd_deregister_mr(rdata->mr);
3170                 rdata->mr = NULL;
3171         }
3172 #endif
3173         if (rdata->cfile)
3174                 cifsFileInfo_put(rdata->cfile);
3175
3176         kvfree(rdata->pages);
3177         kfree(rdata);
3178 }
3179
3180 static int
3181 cifs_read_allocate_pages(struct cifs_readdata *rdata, unsigned int nr_pages)
3182 {
3183         int rc = 0;
3184         struct page *page;
3185         unsigned int i;
3186
3187         for (i = 0; i < nr_pages; i++) {
3188                 page = alloc_page(GFP_KERNEL|__GFP_HIGHMEM);
3189                 if (!page) {
3190                         rc = -ENOMEM;
3191                         break;
3192                 }
3193                 rdata->pages[i] = page;
3194         }
3195
3196         if (rc) {
3197                 for (i = 0; i < nr_pages; i++) {
3198                         put_page(rdata->pages[i]);
3199                         rdata->pages[i] = NULL;
3200                 }
3201         }
3202         return rc;
3203 }
3204
3205 static void
3206 cifs_uncached_readdata_release(struct kref *refcount)
3207 {
3208         struct cifs_readdata *rdata = container_of(refcount,
3209                                         struct cifs_readdata, refcount);
3210         unsigned int i;
3211
3212         kref_put(&rdata->ctx->refcount, cifs_aio_ctx_release);
3213         for (i = 0; i < rdata->nr_pages; i++) {
3214                 put_page(rdata->pages[i]);
3215         }
3216         cifs_readdata_release(refcount);
3217 }
3218
3219 /**
3220  * cifs_readdata_to_iov - copy data from pages in response to an iovec
3221  * @rdata:      the readdata response with list of pages holding data
3222  * @iter:       destination for our data
3223  *
3224  * This function copies data from a list of pages in a readdata response into
3225  * an array of iovecs. It will first calculate where the data should go
3226  * based on the info in the readdata and then copy the data into that spot.
3227  */
3228 static int
3229 cifs_readdata_to_iov(struct cifs_readdata *rdata, struct iov_iter *iter)
3230 {
3231         size_t remaining = rdata->got_bytes;
3232         unsigned int i;
3233
3234         for (i = 0; i < rdata->nr_pages; i++) {
3235                 struct page *page = rdata->pages[i];
3236                 size_t copy = min_t(size_t, remaining, PAGE_SIZE);
3237                 size_t written;
3238
3239                 if (unlikely(iov_iter_is_pipe(iter))) {
3240                         void *addr = kmap_atomic(page);
3241
3242                         written = copy_to_iter(addr, copy, iter);
3243                         kunmap_atomic(addr);
3244                 } else
3245                         written = copy_page_to_iter(page, 0, copy, iter);
3246                 remaining -= written;
3247                 if (written < copy && iov_iter_count(iter) > 0)
3248                         break;
3249         }
3250         return remaining ? -EFAULT : 0;
3251 }
3252
3253 static void collect_uncached_read_data(struct cifs_aio_ctx *ctx);
3254
3255 static void
3256 cifs_uncached_readv_complete(struct work_struct *work)
3257 {
3258         struct cifs_readdata *rdata = container_of(work,
3259                                                 struct cifs_readdata, work);
3260
3261         complete(&rdata->done);
3262         collect_uncached_read_data(rdata->ctx);
3263         /* the below call can possibly free the last ref to aio ctx */
3264         kref_put(&rdata->refcount, cifs_uncached_readdata_release);
3265 }
3266
3267 static int
3268 uncached_fill_pages(struct TCP_Server_Info *server,
3269                     struct cifs_readdata *rdata, struct iov_iter *iter,
3270                     unsigned int len)
3271 {
3272         int result = 0;
3273         unsigned int i;
3274         unsigned int nr_pages = rdata->nr_pages;
3275         unsigned int page_offset = rdata->page_offset;
3276
3277         rdata->got_bytes = 0;
3278         rdata->tailsz = PAGE_SIZE;
3279         for (i = 0; i < nr_pages; i++) {
3280                 struct page *page = rdata->pages[i];
3281                 size_t n;
3282                 unsigned int segment_size = rdata->pagesz;
3283
3284                 if (i == 0)
3285                         segment_size -= page_offset;
3286                 else
3287                         page_offset = 0;
3288
3289
3290                 if (len <= 0) {
3291                         /* no need to hold page hostage */
3292                         rdata->pages[i] = NULL;
3293                         rdata->nr_pages--;
3294                         put_page(page);
3295                         continue;
3296                 }
3297
3298                 n = len;
3299                 if (len >= segment_size)
3300                         /* enough data to fill the page */
3301                         n = segment_size;
3302                 else
3303                         rdata->tailsz = len;
3304                 len -= n;
3305
3306                 if (iter)
3307                         result = copy_page_from_iter(
3308                                         page, page_offset, n, iter);
3309 #ifdef CONFIG_CIFS_SMB_DIRECT
3310                 else if (rdata->mr)
3311                         result = n;
3312 #endif
3313                 else
3314                         result = cifs_read_page_from_socket(
3315                                         server, page, page_offset, n);
3316                 if (result < 0)
3317                         break;
3318
3319                 rdata->got_bytes += result;
3320         }
3321
3322         return rdata->got_bytes > 0 && result != -ECONNABORTED ?
3323                                                 rdata->got_bytes : result;
3324 }
3325
3326 static int
3327 cifs_uncached_read_into_pages(struct TCP_Server_Info *server,
3328                               struct cifs_readdata *rdata, unsigned int len)
3329 {
3330         return uncached_fill_pages(server, rdata, NULL, len);
3331 }
3332
3333 static int
3334 cifs_uncached_copy_into_pages(struct TCP_Server_Info *server,
3335                               struct cifs_readdata *rdata,
3336                               struct iov_iter *iter)
3337 {
3338         return uncached_fill_pages(server, rdata, iter, iter->count);
3339 }
3340
3341 static int cifs_resend_rdata(struct cifs_readdata *rdata,
3342                         struct list_head *rdata_list,
3343                         struct cifs_aio_ctx *ctx)
3344 {
3345         unsigned int rsize;
3346         struct cifs_credits credits;
3347         int rc;
3348         struct TCP_Server_Info *server =
3349                 tlink_tcon(rdata->cfile->tlink)->ses->server;
3350
3351         /*
3352          * Wait for credits to resend this rdata.
3353          * Note: we are attempting to resend the whole rdata not in segments
3354          */
3355         do {
3356                 rc = server->ops->wait_mtu_credits(server, rdata->bytes,
3357                                                 &rsize, &credits);
3358
3359                 if (rc)
3360                         goto out;
3361
3362                 if (rsize < rdata->bytes) {
3363                         add_credits_and_wake_if(server, &credits, 0);
3364                         msleep(1000);
3365                 }
3366         } while (rsize < rdata->bytes);
3367
3368         rdata->credits = credits;
3369         rc = -EAGAIN;
3370         while (rc == -EAGAIN) {
3371                 rc = 0;
3372                 if (rdata->cfile->invalidHandle)
3373                         rc = cifs_reopen_file(rdata->cfile, true);
3374                 if (!rc)
3375                         rc = server->ops->async_readv(rdata);
3376         }
3377
3378         if (!rc) {
3379                 /* Add to aio pending list */
3380                 list_add_tail(&rdata->list, rdata_list);
3381                 return 0;
3382         }
3383
3384         add_credits_and_wake_if(server, &rdata->credits, 0);
3385 out:
3386         kref_put(&rdata->refcount,
3387                 cifs_uncached_readdata_release);
3388
3389         return rc;
3390 }
3391
3392 static int
3393 cifs_send_async_read(loff_t offset, size_t len, struct cifsFileInfo *open_file,
3394                      struct cifs_sb_info *cifs_sb, struct list_head *rdata_list,
3395                      struct cifs_aio_ctx *ctx)
3396 {
3397         struct cifs_readdata *rdata;
3398         unsigned int npages, rsize;
3399         struct cifs_credits credits_on_stack;
3400         struct cifs_credits *credits = &credits_on_stack;
3401         size_t cur_len;
3402         int rc;
3403         pid_t pid;
3404         struct TCP_Server_Info *server;
3405         struct page **pagevec;
3406         size_t start;
3407         struct iov_iter direct_iov = ctx->iter;
3408
3409         server = tlink_tcon(open_file->tlink)->ses->server;
3410
3411         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
3412                 pid = open_file->pid;
3413         else
3414                 pid = current->tgid;
3415
3416         if (ctx->direct_io)
3417                 iov_iter_advance(&direct_iov, offset - ctx->pos);
3418
3419         do {
3420                 if (open_file->invalidHandle) {
3421                         rc = cifs_reopen_file(open_file, true);
3422                         if (rc == -EAGAIN)
3423                                 continue;
3424                         else if (rc)
3425                                 break;
3426                 }
3427
3428                 rc = server->ops->wait_mtu_credits(server, cifs_sb->rsize,
3429                                                    &rsize, credits);
3430                 if (rc)
3431                         break;
3432
3433                 cur_len = min_t(const size_t, len, rsize);
3434
3435                 if (ctx->direct_io) {
3436                         ssize_t result;
3437
3438                         result = iov_iter_get_pages_alloc(
3439                                         &direct_iov, &pagevec,
3440                                         cur_len, &start);
3441                         if (result < 0) {
3442                                 cifs_dbg(VFS,
3443                                         "couldn't get user pages (rc=%zd)"
3444                                         " iter type %d"
3445                                         " iov_offset %zd count %zd\n",
3446                                         result, direct_iov.type,
3447                                         direct_iov.iov_offset,
3448                                         direct_iov.count);
3449                                 dump_stack();
3450
3451                                 rc = result;
3452                                 add_credits_and_wake_if(server, credits, 0);
3453                                 break;
3454                         }
3455                         cur_len = (size_t)result;
3456                         iov_iter_advance(&direct_iov, cur_len);
3457
3458                         rdata = cifs_readdata_direct_alloc(
3459                                         pagevec, cifs_uncached_readv_complete);
3460                         if (!rdata) {
3461                                 add_credits_and_wake_if(server, credits, 0);
3462                                 rc = -ENOMEM;
3463                                 break;
3464                         }
3465
3466                         npages = (cur_len + start + PAGE_SIZE-1) / PAGE_SIZE;
3467                         rdata->page_offset = start;
3468                         rdata->tailsz = npages > 1 ?
3469                                 cur_len-(PAGE_SIZE-start)-(npages-2)*PAGE_SIZE :
3470                                 cur_len;
3471
3472                 } else {
3473
3474                         npages = DIV_ROUND_UP(cur_len, PAGE_SIZE);
3475                         /* allocate a readdata struct */
3476                         rdata = cifs_readdata_alloc(npages,
3477                                             cifs_uncached_readv_complete);
3478                         if (!rdata) {
3479                                 add_credits_and_wake_if(server, credits, 0);
3480                                 rc = -ENOMEM;
3481                                 break;
3482                         }
3483
3484                         rc = cifs_read_allocate_pages(rdata, npages);
3485                         if (rc) {
3486                                 kvfree(rdata->pages);
3487                                 kfree(rdata);
3488                                 add_credits_and_wake_if(server, credits, 0);
3489                                 break;
3490                         }
3491
3492                         rdata->tailsz = PAGE_SIZE;
3493                 }
3494
3495                 rdata->cfile = cifsFileInfo_get(open_file);
3496                 rdata->nr_pages = npages;
3497                 rdata->offset = offset;
3498                 rdata->bytes = cur_len;
3499                 rdata->pid = pid;
3500                 rdata->pagesz = PAGE_SIZE;
3501                 rdata->read_into_pages = cifs_uncached_read_into_pages;
3502                 rdata->copy_into_pages = cifs_uncached_copy_into_pages;
3503                 rdata->credits = credits_on_stack;
3504                 rdata->ctx = ctx;
3505                 kref_get(&ctx->refcount);
3506
3507                 rc = adjust_credits(server, &rdata->credits, rdata->bytes);
3508
3509                 if (!rc) {
3510                         if (rdata->cfile->invalidHandle)
3511                                 rc = -EAGAIN;
3512                         else
3513                                 rc = server->ops->async_readv(rdata);
3514                 }
3515
3516                 if (rc) {
3517                         add_credits_and_wake_if(server, &rdata->credits, 0);
3518                         kref_put(&rdata->refcount,
3519                                 cifs_uncached_readdata_release);
3520                         if (rc == -EAGAIN) {
3521                                 iov_iter_revert(&direct_iov, cur_len);
3522                                 continue;
3523                         }
3524                         break;
3525                 }
3526
3527                 list_add_tail(&rdata->list, rdata_list);
3528                 offset += cur_len;
3529                 len -= cur_len;
3530         } while (len > 0);
3531
3532         return rc;
3533 }
3534
3535 static void
3536 collect_uncached_read_data(struct cifs_aio_ctx *ctx)
3537 {
3538         struct cifs_readdata *rdata, *tmp;
3539         struct iov_iter *to = &ctx->iter;
3540         struct cifs_sb_info *cifs_sb;
3541         struct cifs_tcon *tcon;
3542         unsigned int i;
3543         int rc;
3544
3545         tcon = tlink_tcon(ctx->cfile->tlink);
3546         cifs_sb = CIFS_SB(ctx->cfile->dentry->d_sb);
3547
3548         mutex_lock(&ctx->aio_mutex);
3549
3550         if (list_empty(&ctx->list)) {
3551                 mutex_unlock(&ctx->aio_mutex);
3552                 return;
3553         }
3554
3555         rc = ctx->rc;
3556         /* the loop below should proceed in the order of increasing offsets */
3557 again:
3558         list_for_each_entry_safe(rdata, tmp, &ctx->list, list) {
3559                 if (!rc) {
3560                         if (!try_wait_for_completion(&rdata->done)) {
3561                                 mutex_unlock(&ctx->aio_mutex);
3562                                 return;
3563                         }
3564
3565                         if (rdata->result == -EAGAIN) {
3566                                 /* resend call if it's a retryable error */
3567                                 struct list_head tmp_list;
3568                                 unsigned int got_bytes = rdata->got_bytes;
3569
3570                                 list_del_init(&rdata->list);
3571                                 INIT_LIST_HEAD(&tmp_list);
3572
3573                                 /*
3574                                  * Got a part of data and then reconnect has
3575                                  * happened -- fill the buffer and continue
3576                                  * reading.
3577                                  */
3578                                 if (got_bytes && got_bytes < rdata->bytes) {
3579                                         rc = 0;
3580                                         if (!ctx->direct_io)
3581                                                 rc = cifs_readdata_to_iov(rdata, to);
3582                                         if (rc) {
3583                                                 kref_put(&rdata->refcount,
3584                                                         cifs_uncached_readdata_release);
3585                                                 continue;
3586                                         }
3587                                 }
3588
3589                                 if (ctx->direct_io) {
3590                                         /*
3591                                          * Re-use rdata as this is a
3592                                          * direct I/O
3593                                          */
3594                                         rc = cifs_resend_rdata(
3595                                                 rdata,
3596                                                 &tmp_list, ctx);
3597                                 } else {
3598                                         rc = cifs_send_async_read(
3599                                                 rdata->offset + got_bytes,
3600                                                 rdata->bytes - got_bytes,
3601                                                 rdata->cfile, cifs_sb,
3602                                                 &tmp_list, ctx);
3603
3604                                         kref_put(&rdata->refcount,
3605                                                 cifs_uncached_readdata_release);
3606                                 }
3607
3608                                 list_splice(&tmp_list, &ctx->list);
3609
3610                                 goto again;
3611                         } else if (rdata->result)
3612                                 rc = rdata->result;
3613                         else if (!ctx->direct_io)
3614                                 rc = cifs_readdata_to_iov(rdata, to);
3615
3616                         /* if there was a short read -- discard anything left */
3617                         if (rdata->got_bytes && rdata->got_bytes < rdata->bytes)
3618                                 rc = -ENODATA;
3619
3620                         ctx->total_len += rdata->got_bytes;
3621                 }
3622                 list_del_init(&rdata->list);
3623                 kref_put(&rdata->refcount, cifs_uncached_readdata_release);
3624         }
3625
3626         if (!ctx->direct_io) {
3627                 for (i = 0; i < ctx->npages; i++) {
3628                         if (ctx->should_dirty)
3629                                 set_page_dirty(ctx->bv[i].bv_page);
3630                         put_page(ctx->bv[i].bv_page);
3631                 }
3632
3633                 ctx->total_len = ctx->len - iov_iter_count(to);
3634         }
3635
3636         /* mask nodata case */
3637         if (rc == -ENODATA)
3638                 rc = 0;
3639
3640         ctx->rc = (rc == 0) ? ctx->total_len : rc;
3641
3642         mutex_unlock(&ctx->aio_mutex);
3643
3644         if (ctx->iocb && ctx->iocb->ki_complete)
3645                 ctx->iocb->ki_complete(ctx->iocb, ctx->rc, 0);
3646         else
3647                 complete(&ctx->done);
3648 }
3649
3650 static ssize_t __cifs_readv(
3651         struct kiocb *iocb, struct iov_iter *to, bool direct)
3652 {
3653         size_t len;
3654         struct file *file = iocb->ki_filp;
3655         struct cifs_sb_info *cifs_sb;
3656         struct cifsFileInfo *cfile;
3657         struct cifs_tcon *tcon;
3658         ssize_t rc, total_read = 0;
3659         loff_t offset = iocb->ki_pos;
3660         struct cifs_aio_ctx *ctx;
3661
3662         /*
3663          * iov_iter_get_pages_alloc() doesn't work with ITER_KVEC,
3664          * fall back to data copy read path
3665          * this could be improved by getting pages directly in ITER_KVEC
3666          */
3667         if (direct && to->type & ITER_KVEC) {
3668                 cifs_dbg(FYI, "use non-direct cifs_user_readv for kvec I/O\n");
3669                 direct = false;
3670         }
3671
3672         len = iov_iter_count(to);
3673         if (!len)
3674                 return 0;
3675
3676         cifs_sb = CIFS_FILE_SB(file);
3677         cfile = file->private_data;
3678         tcon = tlink_tcon(cfile->tlink);
3679
3680         if (!tcon->ses->server->ops->async_readv)
3681                 return -ENOSYS;
3682
3683         if ((file->f_flags & O_ACCMODE) == O_WRONLY)
3684                 cifs_dbg(FYI, "attempting read on write only file instance\n");
3685
3686         ctx = cifs_aio_ctx_alloc();
3687         if (!ctx)
3688                 return -ENOMEM;
3689
3690         ctx->cfile = cifsFileInfo_get(cfile);
3691
3692         if (!is_sync_kiocb(iocb))
3693                 ctx->iocb = iocb;
3694
3695         if (iter_is_iovec(to))
3696                 ctx->should_dirty = true;
3697
3698         if (direct) {
3699                 ctx->pos = offset;
3700                 ctx->direct_io = true;
3701                 ctx->iter = *to;
3702                 ctx->len = len;
3703         } else {
3704                 rc = setup_aio_ctx_iter(ctx, to, READ);
3705                 if (rc) {
3706                         kref_put(&ctx->refcount, cifs_aio_ctx_release);
3707                         return rc;
3708                 }
3709                 len = ctx->len;
3710         }
3711
3712         /* grab a lock here due to read response handlers can access ctx */
3713         mutex_lock(&ctx->aio_mutex);
3714
3715         rc = cifs_send_async_read(offset, len, cfile, cifs_sb, &ctx->list, ctx);
3716
3717         /* if at least one read request send succeeded, then reset rc */
3718         if (!list_empty(&ctx->list))
3719                 rc = 0;
3720
3721         mutex_unlock(&ctx->aio_mutex);
3722
3723         if (rc) {
3724                 kref_put(&ctx->refcount, cifs_aio_ctx_release);
3725                 return rc;
3726         }
3727
3728         if (!is_sync_kiocb(iocb)) {
3729                 kref_put(&ctx->refcount, cifs_aio_ctx_release);
3730                 return -EIOCBQUEUED;
3731         }
3732
3733         rc = wait_for_completion_killable(&ctx->done);
3734         if (rc) {
3735                 mutex_lock(&ctx->aio_mutex);
3736                 ctx->rc = rc = -EINTR;
3737                 total_read = ctx->total_len;
3738                 mutex_unlock(&ctx->aio_mutex);
3739         } else {
3740                 rc = ctx->rc;
3741                 total_read = ctx->total_len;
3742         }
3743
3744         kref_put(&ctx->refcount, cifs_aio_ctx_release);
3745
3746         if (total_read) {
3747                 iocb->ki_pos += total_read;
3748                 return total_read;
3749         }
3750         return rc;
3751 }
3752
3753 ssize_t cifs_direct_readv(struct kiocb *iocb, struct iov_iter *to)
3754 {
3755         return __cifs_readv(iocb, to, true);
3756 }
3757
3758 ssize_t cifs_user_readv(struct kiocb *iocb, struct iov_iter *to)
3759 {
3760         return __cifs_readv(iocb, to, false);
3761 }
3762
3763 ssize_t
3764 cifs_strict_readv(struct kiocb *iocb, struct iov_iter *to)
3765 {
3766         struct inode *inode = file_inode(iocb->ki_filp);
3767         struct cifsInodeInfo *cinode = CIFS_I(inode);
3768         struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
3769         struct cifsFileInfo *cfile = (struct cifsFileInfo *)
3770                                                 iocb->ki_filp->private_data;
3771         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
3772         int rc = -EACCES;
3773
3774         /*
3775          * In strict cache mode we need to read from the server all the time
3776          * if we don't have level II oplock because the server can delay mtime
3777          * change - so we can't make a decision about inode invalidating.
3778          * And we can also fail with pagereading if there are mandatory locks
3779          * on pages affected by this read but not on the region from pos to
3780          * pos+len-1.
3781          */
3782         if (!CIFS_CACHE_READ(cinode))
3783                 return cifs_user_readv(iocb, to);
3784
3785         if (cap_unix(tcon->ses) &&
3786             (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
3787             ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
3788                 return generic_file_read_iter(iocb, to);
3789
3790         /*
3791          * We need to hold the sem to be sure nobody modifies lock list
3792          * with a brlock that prevents reading.
3793          */
3794         down_read(&cinode->lock_sem);
3795         if (!cifs_find_lock_conflict(cfile, iocb->ki_pos, iov_iter_count(to),
3796                                      tcon->ses->server->vals->shared_lock_type,
3797                                      0, NULL, CIFS_READ_OP))
3798                 rc = generic_file_read_iter(iocb, to);
3799         up_read(&cinode->lock_sem);
3800         return rc;
3801 }
3802
3803 static ssize_t
3804 cifs_read(struct file *file, char *read_data, size_t read_size, loff_t *offset)
3805 {
3806         int rc = -EACCES;
3807         unsigned int bytes_read = 0;
3808         unsigned int total_read;
3809         unsigned int current_read_size;
3810         unsigned int rsize;
3811         struct cifs_sb_info *cifs_sb;
3812         struct cifs_tcon *tcon;
3813         struct TCP_Server_Info *server;
3814         unsigned int xid;
3815         char *cur_offset;
3816         struct cifsFileInfo *open_file;
3817         struct cifs_io_parms io_parms;
3818         int buf_type = CIFS_NO_BUFFER;
3819         __u32 pid;
3820
3821         xid = get_xid();
3822         cifs_sb = CIFS_FILE_SB(file);
3823
3824         /* FIXME: set up handlers for larger reads and/or convert to async */
3825         rsize = min_t(unsigned int, cifs_sb->rsize, CIFSMaxBufSize);
3826
3827         if (file->private_data == NULL) {
3828                 rc = -EBADF;
3829                 free_xid(xid);
3830                 return rc;
3831         }
3832         open_file = file->private_data;
3833         tcon = tlink_tcon(open_file->tlink);
3834         server = tcon->ses->server;
3835
3836         if (!server->ops->sync_read) {
3837                 free_xid(xid);
3838                 return -ENOSYS;
3839         }
3840
3841         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
3842                 pid = open_file->pid;
3843         else
3844                 pid = current->tgid;
3845
3846         if ((file->f_flags & O_ACCMODE) == O_WRONLY)
3847                 cifs_dbg(FYI, "attempting read on write only file instance\n");
3848
3849         for (total_read = 0, cur_offset = read_data; read_size > total_read;
3850              total_read += bytes_read, cur_offset += bytes_read) {
3851                 do {
3852                         current_read_size = min_t(uint, read_size - total_read,
3853                                                   rsize);
3854                         /*
3855                          * For windows me and 9x we do not want to request more
3856                          * than it negotiated since it will refuse the read
3857                          * then.
3858                          */
3859                         if ((tcon->ses) && !(tcon->ses->capabilities &
3860                                 tcon->ses->server->vals->cap_large_files)) {
3861                                 current_read_size = min_t(uint,
3862                                         current_read_size, CIFSMaxBufSize);
3863                         }
3864                         if (open_file->invalidHandle) {
3865                                 rc = cifs_reopen_file(open_file, true);
3866                                 if (rc != 0)
3867                                         break;
3868                         }
3869                         io_parms.pid = pid;
3870                         io_parms.tcon = tcon;
3871                         io_parms.offset = *offset;
3872                         io_parms.length = current_read_size;
3873                         rc = server->ops->sync_read(xid, &open_file->fid, &io_parms,
3874                                                     &bytes_read, &cur_offset,
3875                                                     &buf_type);
3876                 } while (rc == -EAGAIN);
3877
3878                 if (rc || (bytes_read == 0)) {
3879                         if (total_read) {
3880                                 break;
3881                         } else {
3882                                 free_xid(xid);
3883                                 return rc;
3884                         }
3885                 } else {
3886                         cifs_stats_bytes_read(tcon, total_read);
3887                         *offset += bytes_read;
3888                 }
3889         }
3890         free_xid(xid);
3891         return total_read;
3892 }
3893
3894 /*
3895  * If the page is mmap'ed into a process' page tables, then we need to make
3896  * sure that it doesn't change while being written back.
3897  */
3898 static vm_fault_t
3899 cifs_page_mkwrite(struct vm_fault *vmf)
3900 {
3901         struct page *page = vmf->page;
3902
3903         lock_page(page);
3904         return VM_FAULT_LOCKED;
3905 }
3906
3907 static const struct vm_operations_struct cifs_file_vm_ops = {
3908         .fault = filemap_fault,
3909         .map_pages = filemap_map_pages,
3910         .page_mkwrite = cifs_page_mkwrite,
3911 };
3912
3913 int cifs_file_strict_mmap(struct file *file, struct vm_area_struct *vma)
3914 {
3915         int xid, rc = 0;
3916         struct inode *inode = file_inode(file);
3917
3918         xid = get_xid();
3919
3920         if (!CIFS_CACHE_READ(CIFS_I(inode)))
3921                 rc = cifs_zap_mapping(inode);
3922         if (!rc)
3923                 rc = generic_file_mmap(file, vma);
3924         if (!rc)
3925                 vma->vm_ops = &cifs_file_vm_ops;
3926
3927         free_xid(xid);
3928         return rc;
3929 }
3930
3931 int cifs_file_mmap(struct file *file, struct vm_area_struct *vma)
3932 {
3933         int rc, xid;
3934
3935         xid = get_xid();
3936
3937         rc = cifs_revalidate_file(file);
3938         if (rc)
3939                 cifs_dbg(FYI, "Validation prior to mmap failed, error=%d\n",
3940                          rc);
3941         if (!rc)
3942                 rc = generic_file_mmap(file, vma);
3943         if (!rc)
3944                 vma->vm_ops = &cifs_file_vm_ops;
3945
3946         free_xid(xid);
3947         return rc;
3948 }
3949
3950 static void
3951 cifs_readv_complete(struct work_struct *work)
3952 {
3953         unsigned int i, got_bytes;
3954         struct cifs_readdata *rdata = container_of(work,
3955                                                 struct cifs_readdata, work);
3956
3957         got_bytes = rdata->got_bytes;
3958         for (i = 0; i < rdata->nr_pages; i++) {
3959                 struct page *page = rdata->pages[i];
3960
3961                 lru_cache_add_file(page);
3962
3963                 if (rdata->result == 0 ||
3964                     (rdata->result == -EAGAIN && got_bytes)) {
3965                         flush_dcache_page(page);
3966                         SetPageUptodate(page);
3967                 }
3968
3969                 unlock_page(page);
3970
3971                 if (rdata->result == 0 ||
3972                     (rdata->result == -EAGAIN && got_bytes))
3973                         cifs_readpage_to_fscache(rdata->mapping->host, page);
3974
3975                 got_bytes -= min_t(unsigned int, PAGE_SIZE, got_bytes);
3976
3977                 put_page(page);
3978                 rdata->pages[i] = NULL;
3979         }
3980         kref_put(&rdata->refcount, cifs_readdata_release);
3981 }
3982
3983 static int
3984 readpages_fill_pages(struct TCP_Server_Info *server,
3985                      struct cifs_readdata *rdata, struct iov_iter *iter,
3986                      unsigned int len)
3987 {
3988         int result = 0;
3989         unsigned int i;
3990         u64 eof;
3991         pgoff_t eof_index;
3992         unsigned int nr_pages = rdata->nr_pages;
3993         unsigned int page_offset = rdata->page_offset;
3994
3995         /* determine the eof that the server (probably) has */
3996         eof = CIFS_I(rdata->mapping->host)->server_eof;
3997         eof_index = eof ? (eof - 1) >> PAGE_SHIFT : 0;
3998         cifs_dbg(FYI, "eof=%llu eof_index=%lu\n", eof, eof_index);
3999
4000         rdata->got_bytes = 0;
4001         rdata->tailsz = PAGE_SIZE;
4002         for (i = 0; i < nr_pages; i++) {
4003                 struct page *page = rdata->pages[i];
4004                 unsigned int to_read = rdata->pagesz;
4005                 size_t n;
4006
4007                 if (i == 0)
4008                         to_read -= page_offset;
4009                 else
4010                         page_offset = 0;
4011
4012                 n = to_read;
4013
4014                 if (len >= to_read) {
4015                         len -= to_read;
4016                 } else if (len > 0) {
4017                         /* enough for partial page, fill and zero the rest */
4018                         zero_user(page, len + page_offset, to_read - len);
4019                         n = rdata->tailsz = len;
4020                         len = 0;
4021                 } else if (page->index > eof_index) {
4022                         /*
4023                          * The VFS will not try to do readahead past the
4024                          * i_size, but it's possible that we have outstanding
4025                          * writes with gaps in the middle and the i_size hasn't
4026                          * caught up yet. Populate those with zeroed out pages
4027                          * to prevent the VFS from repeatedly attempting to
4028                          * fill them until the writes are flushed.
4029                          */
4030                         zero_user(page, 0, PAGE_SIZE);
4031                         lru_cache_add_file(page);
4032                         flush_dcache_page(page);
4033                         SetPageUptodate(page);
4034                         unlock_page(page);
4035                         put_page(page);
4036                         rdata->pages[i] = NULL;
4037                         rdata->nr_pages--;
4038                         continue;
4039                 } else {
4040                         /* no need to hold page hostage */
4041                         lru_cache_add_file(page);
4042                         unlock_page(page);
4043                         put_page(page);
4044                         rdata->pages[i] = NULL;
4045                         rdata->nr_pages--;
4046                         continue;
4047                 }
4048
4049                 if (iter)
4050                         result = copy_page_from_iter(
4051                                         page, page_offset, n, iter);
4052 #ifdef CONFIG_CIFS_SMB_DIRECT
4053                 else if (rdata->mr)
4054                         result = n;
4055 #endif
4056                 else
4057                         result = cifs_read_page_from_socket(
4058                                         server, page, page_offset, n);
4059                 if (result < 0)
4060                         break;
4061
4062                 rdata->got_bytes += result;
4063         }
4064
4065         return rdata->got_bytes > 0 && result != -ECONNABORTED ?
4066                                                 rdata->got_bytes : result;
4067 }
4068
4069 static int
4070 cifs_readpages_read_into_pages(struct TCP_Server_Info *server,
4071                                struct cifs_readdata *rdata, unsigned int len)
4072 {
4073         return readpages_fill_pages(server, rdata, NULL, len);
4074 }
4075
4076 static int
4077 cifs_readpages_copy_into_pages(struct TCP_Server_Info *server,
4078                                struct cifs_readdata *rdata,
4079                                struct iov_iter *iter)
4080 {
4081         return readpages_fill_pages(server, rdata, iter, iter->count);
4082 }
4083
4084 static int
4085 readpages_get_pages(struct address_space *mapping, struct list_head *page_list,
4086                     unsigned int rsize, struct list_head *tmplist,
4087                     unsigned int *nr_pages, loff_t *offset, unsigned int *bytes)
4088 {
4089         struct page *page, *tpage;
4090         unsigned int expected_index;
4091         int rc;
4092         gfp_t gfp = readahead_gfp_mask(mapping);
4093
4094         INIT_LIST_HEAD(tmplist);
4095
4096         page = lru_to_page(page_list);
4097
4098         /*
4099          * Lock the page and put it in the cache. Since no one else
4100          * should have access to this page, we're safe to simply set
4101          * PG_locked without checking it first.
4102          */
4103         __SetPageLocked(page);
4104         rc = add_to_page_cache_locked(page, mapping,
4105                                       page->index, gfp);
4106
4107         /* give up if we can't stick it in the cache */
4108         if (rc) {
4109                 __ClearPageLocked(page);
4110                 return rc;
4111         }
4112
4113         /* move first page to the tmplist */
4114         *offset = (loff_t)page->index << PAGE_SHIFT;
4115         *bytes = PAGE_SIZE;
4116         *nr_pages = 1;
4117         list_move_tail(&page->lru, tmplist);
4118
4119         /* now try and add more pages onto the request */
4120         expected_index = page->index + 1;
4121         list_for_each_entry_safe_reverse(page, tpage, page_list, lru) {
4122                 /* discontinuity ? */
4123                 if (page->index != expected_index)
4124                         break;
4125
4126                 /* would this page push the read over the rsize? */
4127                 if (*bytes + PAGE_SIZE > rsize)
4128                         break;
4129
4130                 __SetPageLocked(page);
4131                 if (add_to_page_cache_locked(page, mapping, page->index, gfp)) {
4132                         __ClearPageLocked(page);
4133                         break;
4134                 }
4135                 list_move_tail(&page->lru, tmplist);
4136                 (*bytes) += PAGE_SIZE;
4137                 expected_index++;
4138                 (*nr_pages)++;
4139         }
4140         return rc;
4141 }
4142
4143 static int cifs_readpages(struct file *file, struct address_space *mapping,
4144         struct list_head *page_list, unsigned num_pages)
4145 {
4146         int rc;
4147         struct list_head tmplist;
4148         struct cifsFileInfo *open_file = file->private_data;
4149         struct cifs_sb_info *cifs_sb = CIFS_FILE_SB(file);
4150         struct TCP_Server_Info *server;
4151         pid_t pid;
4152         unsigned int xid;
4153
4154         xid = get_xid();
4155         /*
4156          * Reads as many pages as possible from fscache. Returns -ENOBUFS
4157          * immediately if the cookie is negative
4158          *
4159          * After this point, every page in the list might have PG_fscache set,
4160          * so we will need to clean that up off of every page we don't use.
4161          */
4162         rc = cifs_readpages_from_fscache(mapping->host, mapping, page_list,
4163                                          &num_pages);
4164         if (rc == 0) {
4165                 free_xid(xid);
4166                 return rc;
4167         }
4168
4169         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
4170                 pid = open_file->pid;
4171         else
4172                 pid = current->tgid;
4173
4174         rc = 0;
4175         server = tlink_tcon(open_file->tlink)->ses->server;
4176
4177         cifs_dbg(FYI, "%s: file=%p mapping=%p num_pages=%u\n",
4178                  __func__, file, mapping, num_pages);
4179
4180         /*
4181          * Start with the page at end of list and move it to private
4182          * list. Do the same with any following pages until we hit
4183          * the rsize limit, hit an index discontinuity, or run out of
4184          * pages. Issue the async read and then start the loop again
4185          * until the list is empty.
4186          *
4187          * Note that list order is important. The page_list is in
4188          * the order of declining indexes. When we put the pages in
4189          * the rdata->pages, then we want them in increasing order.
4190          */
4191         while (!list_empty(page_list)) {
4192                 unsigned int i, nr_pages, bytes, rsize;
4193                 loff_t offset;
4194                 struct page *page, *tpage;
4195                 struct cifs_readdata *rdata;
4196                 struct cifs_credits credits_on_stack;
4197                 struct cifs_credits *credits = &credits_on_stack;
4198
4199                 if (open_file->invalidHandle) {
4200                         rc = cifs_reopen_file(open_file, true);
4201                         if (rc == -EAGAIN)
4202                                 continue;
4203                         else if (rc)
4204                                 break;
4205                 }
4206
4207                 rc = server->ops->wait_mtu_credits(server, cifs_sb->rsize,
4208                                                    &rsize, credits);
4209                 if (rc)
4210                         break;
4211
4212                 /*
4213                  * Give up immediately if rsize is too small to read an entire
4214                  * page. The VFS will fall back to readpage. We should never
4215                  * reach this point however since we set ra_pages to 0 when the
4216                  * rsize is smaller than a cache page.
4217                  */
4218                 if (unlikely(rsize < PAGE_SIZE)) {
4219                         add_credits_and_wake_if(server, credits, 0);
4220                         free_xid(xid);
4221                         return 0;
4222                 }
4223
4224                 rc = readpages_get_pages(mapping, page_list, rsize, &tmplist,
4225                                          &nr_pages, &offset, &bytes);
4226                 if (rc) {
4227                         add_credits_and_wake_if(server, credits, 0);
4228                         break;
4229                 }
4230
4231                 rdata = cifs_readdata_alloc(nr_pages, cifs_readv_complete);
4232                 if (!rdata) {
4233                         /* best to give up if we're out of mem */
4234                         list_for_each_entry_safe(page, tpage, &tmplist, lru) {
4235                                 list_del(&page->lru);
4236                                 lru_cache_add_file(page);
4237                                 unlock_page(page);
4238                                 put_page(page);
4239                         }
4240                         rc = -ENOMEM;
4241                         add_credits_and_wake_if(server, credits, 0);
4242                         break;
4243                 }
4244
4245                 rdata->cfile = cifsFileInfo_get(open_file);
4246                 rdata->mapping = mapping;
4247                 rdata->offset = offset;
4248                 rdata->bytes = bytes;
4249                 rdata->pid = pid;
4250                 rdata->pagesz = PAGE_SIZE;
4251                 rdata->tailsz = PAGE_SIZE;
4252                 rdata->read_into_pages = cifs_readpages_read_into_pages;
4253                 rdata->copy_into_pages = cifs_readpages_copy_into_pages;
4254                 rdata->credits = credits_on_stack;
4255
4256                 list_for_each_entry_safe(page, tpage, &tmplist, lru) {
4257                         list_del(&page->lru);
4258                         rdata->pages[rdata->nr_pages++] = page;
4259                 }
4260
4261                 rc = adjust_credits(server, &rdata->credits, rdata->bytes);
4262
4263                 if (!rc) {
4264                         if (rdata->cfile->invalidHandle)
4265                                 rc = -EAGAIN;
4266                         else
4267                                 rc = server->ops->async_readv(rdata);
4268                 }
4269
4270                 if (rc) {
4271                         add_credits_and_wake_if(server, &rdata->credits, 0);
4272                         for (i = 0; i < rdata->nr_pages; i++) {
4273                                 page = rdata->pages[i];
4274                                 lru_cache_add_file(page);
4275                                 unlock_page(page);
4276                                 put_page(page);
4277                         }
4278                         /* Fallback to the readpage in error/reconnect cases */
4279                         kref_put(&rdata->refcount, cifs_readdata_release);
4280                         break;
4281                 }
4282
4283                 kref_put(&rdata->refcount, cifs_readdata_release);
4284         }
4285
4286         /* Any pages that have been shown to fscache but didn't get added to
4287          * the pagecache must be uncached before they get returned to the
4288          * allocator.
4289          */
4290         cifs_fscache_readpages_cancel(mapping->host, page_list);
4291         free_xid(xid);
4292         return rc;
4293 }
4294
4295 /*
4296  * cifs_readpage_worker must be called with the page pinned
4297  */
4298 static int cifs_readpage_worker(struct file *file, struct page *page,
4299         loff_t *poffset)
4300 {
4301         char *read_data;
4302         int rc;
4303
4304         /* Is the page cached? */
4305         rc = cifs_readpage_from_fscache(file_inode(file), page);
4306         if (rc == 0)
4307                 goto read_complete;
4308
4309         read_data = kmap(page);
4310         /* for reads over a certain size could initiate async read ahead */
4311
4312         rc = cifs_read(file, read_data, PAGE_SIZE, poffset);
4313
4314         if (rc < 0)
4315                 goto io_error;
4316         else
4317                 cifs_dbg(FYI, "Bytes read %d\n", rc);
4318
4319         /* we do not want atime to be less than mtime, it broke some apps */
4320         file_inode(file)->i_atime = current_time(file_inode(file));
4321         if (timespec64_compare(&(file_inode(file)->i_atime), &(file_inode(file)->i_mtime)))
4322                 file_inode(file)->i_atime = file_inode(file)->i_mtime;
4323         else
4324                 file_inode(file)->i_atime = current_time(file_inode(file));
4325
4326         if (PAGE_SIZE > rc)
4327                 memset(read_data + rc, 0, PAGE_SIZE - rc);
4328
4329         flush_dcache_page(page);
4330         SetPageUptodate(page);
4331
4332         /* send this page to the cache */
4333         cifs_readpage_to_fscache(file_inode(file), page);
4334
4335         rc = 0;
4336
4337 io_error:
4338         kunmap(page);
4339         unlock_page(page);
4340
4341 read_complete:
4342         return rc;
4343 }
4344
4345 static int cifs_readpage(struct file *file, struct page *page)
4346 {
4347         loff_t offset = (loff_t)page->index << PAGE_SHIFT;
4348         int rc = -EACCES;
4349         unsigned int xid;
4350
4351         xid = get_xid();
4352
4353         if (file->private_data == NULL) {
4354                 rc = -EBADF;
4355                 free_xid(xid);
4356                 return rc;
4357         }
4358
4359         cifs_dbg(FYI, "readpage %p at offset %d 0x%x\n",
4360                  page, (int)offset, (int)offset);
4361
4362         rc = cifs_readpage_worker(file, page, &offset);
4363
4364         free_xid(xid);
4365         return rc;
4366 }
4367
4368 static int is_inode_writable(struct cifsInodeInfo *cifs_inode)
4369 {
4370         struct cifsFileInfo *open_file;
4371         struct cifs_tcon *tcon =
4372                 cifs_sb_master_tcon(CIFS_SB(cifs_inode->vfs_inode.i_sb));
4373
4374         spin_lock(&tcon->open_file_lock);
4375         list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
4376                 if (OPEN_FMODE(open_file->f_flags) & FMODE_WRITE) {
4377                         spin_unlock(&tcon->open_file_lock);
4378                         return 1;
4379                 }
4380         }
4381         spin_unlock(&tcon->open_file_lock);
4382         return 0;
4383 }
4384
4385 /* We do not want to update the file size from server for inodes
4386    open for write - to avoid races with writepage extending
4387    the file - in the future we could consider allowing
4388    refreshing the inode only on increases in the file size
4389    but this is tricky to do without racing with writebehind
4390    page caching in the current Linux kernel design */
4391 bool is_size_safe_to_change(struct cifsInodeInfo *cifsInode, __u64 end_of_file)
4392 {
4393         if (!cifsInode)
4394                 return true;
4395
4396         if (is_inode_writable(cifsInode)) {
4397                 /* This inode is open for write at least once */
4398                 struct cifs_sb_info *cifs_sb;
4399
4400                 cifs_sb = CIFS_SB(cifsInode->vfs_inode.i_sb);
4401                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DIRECT_IO) {
4402                         /* since no page cache to corrupt on directio
4403                         we can change size safely */
4404                         return true;
4405                 }
4406
4407                 if (i_size_read(&cifsInode->vfs_inode) < end_of_file)
4408                         return true;
4409
4410                 return false;
4411         } else
4412                 return true;
4413 }
4414
4415 static int cifs_write_begin(struct file *file, struct address_space *mapping,
4416                         loff_t pos, unsigned len, unsigned flags,
4417                         struct page **pagep, void **fsdata)
4418 {
4419         int oncethru = 0;
4420         pgoff_t index = pos >> PAGE_SHIFT;
4421         loff_t offset = pos & (PAGE_SIZE - 1);
4422         loff_t page_start = pos & PAGE_MASK;
4423         loff_t i_size;
4424         struct page *page;
4425         int rc = 0;
4426
4427         cifs_dbg(FYI, "write_begin from %lld len %d\n", (long long)pos, len);
4428
4429 start:
4430         page = grab_cache_page_write_begin(mapping, index, flags);
4431         if (!page) {
4432                 rc = -ENOMEM;
4433                 goto out;
4434         }
4435
4436         if (PageUptodate(page))
4437                 goto out;
4438
4439         /*
4440          * If we write a full page it will be up to date, no need to read from
4441          * the server. If the write is short, we'll end up doing a sync write
4442          * instead.
4443          */
4444         if (len == PAGE_SIZE)
4445                 goto out;
4446
4447         /*
4448          * optimize away the read when we have an oplock, and we're not
4449          * expecting to use any of the data we'd be reading in. That
4450          * is, when the page lies beyond the EOF, or straddles the EOF
4451          * and the write will cover all of the existing data.
4452          */
4453         if (CIFS_CACHE_READ(CIFS_I(mapping->host))) {
4454                 i_size = i_size_read(mapping->host);
4455                 if (page_start >= i_size ||
4456                     (offset == 0 && (pos + len) >= i_size)) {
4457                         zero_user_segments(page, 0, offset,
4458                                            offset + len,
4459                                            PAGE_SIZE);
4460                         /*
4461                          * PageChecked means that the parts of the page
4462                          * to which we're not writing are considered up
4463                          * to date. Once the data is copied to the
4464                          * page, it can be set uptodate.
4465                          */
4466                         SetPageChecked(page);
4467                         goto out;
4468                 }
4469         }
4470
4471         if ((file->f_flags & O_ACCMODE) != O_WRONLY && !oncethru) {
4472                 /*
4473                  * might as well read a page, it is fast enough. If we get
4474                  * an error, we don't need to return it. cifs_write_end will
4475                  * do a sync write instead since PG_uptodate isn't set.
4476                  */
4477                 cifs_readpage_worker(file, page, &page_start);
4478                 put_page(page);
4479                 oncethru = 1;
4480                 goto start;
4481         } else {
4482                 /* we could try using another file handle if there is one -
4483                    but how would we lock it to prevent close of that handle
4484                    racing with this read? In any case
4485                    this will be written out by write_end so is fine */
4486         }
4487 out:
4488         *pagep = page;
4489         return rc;
4490 }
4491
4492 static int cifs_release_page(struct page *page, gfp_t gfp)
4493 {
4494         if (PagePrivate(page))
4495                 return 0;
4496
4497         return cifs_fscache_release_page(page, gfp);
4498 }
4499
4500 static void cifs_invalidate_page(struct page *page, unsigned int offset,
4501                                  unsigned int length)
4502 {
4503         struct cifsInodeInfo *cifsi = CIFS_I(page->mapping->host);
4504
4505         if (offset == 0 && length == PAGE_SIZE)
4506                 cifs_fscache_invalidate_page(page, &cifsi->vfs_inode);
4507 }
4508
4509 static int cifs_launder_page(struct page *page)
4510 {
4511         int rc = 0;
4512         loff_t range_start = page_offset(page);
4513         loff_t range_end = range_start + (loff_t)(PAGE_SIZE - 1);
4514         struct writeback_control wbc = {
4515                 .sync_mode = WB_SYNC_ALL,
4516                 .nr_to_write = 0,
4517                 .range_start = range_start,
4518                 .range_end = range_end,
4519         };
4520
4521         cifs_dbg(FYI, "Launder page: %p\n", page);
4522
4523         if (clear_page_dirty_for_io(page))
4524                 rc = cifs_writepage_locked(page, &wbc);
4525
4526         cifs_fscache_invalidate_page(page, page->mapping->host);
4527         return rc;
4528 }
4529
4530 void cifs_oplock_break(struct work_struct *work)
4531 {
4532         struct cifsFileInfo *cfile = container_of(work, struct cifsFileInfo,
4533                                                   oplock_break);
4534         struct inode *inode = d_inode(cfile->dentry);
4535         struct cifsInodeInfo *cinode = CIFS_I(inode);
4536         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
4537         struct TCP_Server_Info *server = tcon->ses->server;
4538         int rc = 0;
4539
4540         wait_on_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS,
4541                         TASK_UNINTERRUPTIBLE);
4542
4543         server->ops->downgrade_oplock(server, cinode,
4544                 test_bit(CIFS_INODE_DOWNGRADE_OPLOCK_TO_L2, &cinode->flags));
4545
4546         if (!CIFS_CACHE_WRITE(cinode) && CIFS_CACHE_READ(cinode) &&
4547                                                 cifs_has_mand_locks(cinode)) {
4548                 cifs_dbg(FYI, "Reset oplock to None for inode=%p due to mand locks\n",
4549                          inode);
4550                 cinode->oplock = 0;
4551         }
4552
4553         if (inode && S_ISREG(inode->i_mode)) {
4554                 if (CIFS_CACHE_READ(cinode))
4555                         break_lease(inode, O_RDONLY);
4556                 else
4557                         break_lease(inode, O_WRONLY);
4558                 rc = filemap_fdatawrite(inode->i_mapping);
4559                 if (!CIFS_CACHE_READ(cinode)) {
4560                         rc = filemap_fdatawait(inode->i_mapping);
4561                         mapping_set_error(inode->i_mapping, rc);
4562                         cifs_zap_mapping(inode);
4563                 }
4564                 cifs_dbg(FYI, "Oplock flush inode %p rc %d\n", inode, rc);
4565         }
4566
4567         rc = cifs_push_locks(cfile);
4568         if (rc)
4569                 cifs_dbg(VFS, "Push locks rc = %d\n", rc);
4570
4571         /*
4572          * releasing stale oplock after recent reconnect of smb session using
4573          * a now incorrect file handle is not a data integrity issue but do
4574          * not bother sending an oplock release if session to server still is
4575          * disconnected since oplock already released by the server
4576          */
4577         if (!cfile->oplock_break_cancelled) {
4578                 rc = tcon->ses->server->ops->oplock_response(tcon, &cfile->fid,
4579                                                              cinode);
4580                 cifs_dbg(FYI, "Oplock release rc = %d\n", rc);
4581         }
4582         cifs_done_oplock_break(cinode);
4583 }
4584
4585 /*
4586  * The presence of cifs_direct_io() in the address space ops vector
4587  * allowes open() O_DIRECT flags which would have failed otherwise.
4588  *
4589  * In the non-cached mode (mount with cache=none), we shunt off direct read and write requests
4590  * so this method should never be called.
4591  *
4592  * Direct IO is not yet supported in the cached mode.
4593  */
4594 static ssize_t
4595 cifs_direct_io(struct kiocb *iocb, struct iov_iter *iter)
4596 {
4597         /*
4598          * FIXME
4599          * Eventually need to support direct IO for non forcedirectio mounts
4600          */
4601         return -EINVAL;
4602 }
4603
4604
4605 const struct address_space_operations cifs_addr_ops = {
4606         .readpage = cifs_readpage,
4607         .readpages = cifs_readpages,
4608         .writepage = cifs_writepage,
4609         .writepages = cifs_writepages,
4610         .write_begin = cifs_write_begin,
4611         .write_end = cifs_write_end,
4612         .set_page_dirty = __set_page_dirty_nobuffers,
4613         .releasepage = cifs_release_page,
4614         .direct_IO = cifs_direct_io,
4615         .invalidatepage = cifs_invalidate_page,
4616         .launder_page = cifs_launder_page,
4617 };
4618
4619 /*
4620  * cifs_readpages requires the server to support a buffer large enough to
4621  * contain the header plus one complete page of data.  Otherwise, we need
4622  * to leave cifs_readpages out of the address space operations.
4623  */
4624 const struct address_space_operations cifs_addr_ops_smallbuf = {
4625         .readpage = cifs_readpage,
4626         .writepage = cifs_writepage,
4627         .writepages = cifs_writepages,
4628         .write_begin = cifs_write_begin,
4629         .write_end = cifs_write_end,
4630         .set_page_dirty = __set_page_dirty_nobuffers,
4631         .releasepage = cifs_release_page,
4632         .invalidatepage = cifs_invalidate_page,
4633         .launder_page = cifs_launder_page,
4634 };