fs/cifs/file.c

   1 /*
   2  *   fs/cifs/file.c
   3  *
   4  *   vfs operations that deal with files
   5  *
   6  *   Copyright (C) International Business Machines  Corp., 2002,2010
   7  *   Author(s): Steve French (sfrench@us.ibm.com)
   8  *              Jeremy Allison (jra@samba.org)
   9  *
  10  *   This library is free software; you can redistribute it and/or modify
  11  *   it under the terms of the GNU Lesser General Public License as published
  12  *   by the Free Software Foundation; either version 2.1 of the License, or
  13  *   (at your option) any later version.
  14  *
  15  *   This library is distributed in the hope that it will be useful,
  16  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  18  *   the GNU Lesser General Public License for more details.
  19  *
  20  *   You should have received a copy of the GNU Lesser General Public License
  21  *   along with this library; if not, write to the Free Software
  22  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  23  */
  24 #include <linux/fs.h>
  25 #include <linux/backing-dev.h>
  26 #include <linux/stat.h>
  27 #include <linux/fcntl.h>
  28 #include <linux/pagemap.h>
  29 #include <linux/pagevec.h>
  30 #include <linux/writeback.h>
  31 #include <linux/task_io_accounting_ops.h>
  32 #include <linux/delay.h>
  33 #include <linux/mount.h>
  34 #include <linux/slab.h>
  35 #include <linux/swap.h>
  36 #include <asm/div64.h>
  37 #include "cifsfs.h"
  38 #include "cifspdu.h"
  39 #include "cifsglob.h"
  40 #include "cifsproto.h"
  41 #include "cifs_unicode.h"
  42 #include "cifs_debug.h"
  43 #include "cifs_fs_sb.h"
  44 #include "fscache.h"
  45
  46
  47 static inline int cifs_convert_flags(unsigned int flags)
  48 {
  49         if ((flags & O_ACCMODE) == O_RDONLY)
  50                 return GENERIC_READ;
  51         else if ((flags & O_ACCMODE) == O_WRONLY)
  52                 return GENERIC_WRITE;
  53         else if ((flags & O_ACCMODE) == O_RDWR) {
  54                 /* GENERIC_ALL is too much permission to request
  55                    can cause unnecessary access denied on create */
  56                 /* return GENERIC_ALL; */
  57                 return (GENERIC_READ | GENERIC_WRITE);
  58         }
  59
  60         return (READ_CONTROL | FILE_WRITE_ATTRIBUTES | FILE_READ_ATTRIBUTES |
  61                 FILE_WRITE_EA | FILE_APPEND_DATA | FILE_WRITE_DATA |
  62                 FILE_READ_DATA);
  63 }
  64
  65 static u32 cifs_posix_convert_flags(unsigned int flags)
  66 {
  67         u32 posix_flags = 0;
  68
  69         if ((flags & O_ACCMODE) == O_RDONLY)
  70                 posix_flags = SMB_O_RDONLY;
  71         else if ((flags & O_ACCMODE) == O_WRONLY)
  72                 posix_flags = SMB_O_WRONLY;
  73         else if ((flags & O_ACCMODE) == O_RDWR)
  74                 posix_flags = SMB_O_RDWR;
  75
  76         if (flags & O_CREAT) {
  77                 posix_flags |= SMB_O_CREAT;
  78                 if (flags & O_EXCL)
  79                         posix_flags |= SMB_O_EXCL;
  80         } else if (flags & O_EXCL)
  81                 cifs_dbg(FYI, "Application %s pid %d has incorrectly set O_EXCL flag but not O_CREAT on file open. Ignoring O_EXCL\n",
  82                          current->comm, current->tgid);
  83
  84         if (flags & O_TRUNC)
  85                 posix_flags |= SMB_O_TRUNC;
  86         /* be safe and imply O_SYNC for O_DSYNC */
  87         if (flags & O_DSYNC)
  88                 posix_flags |= SMB_O_SYNC;
  89         if (flags & O_DIRECTORY)
  90                 posix_flags |= SMB_O_DIRECTORY;
  91         if (flags & O_NOFOLLOW)
  92                 posix_flags |= SMB_O_NOFOLLOW;
  93         if (flags & O_DIRECT)
  94                 posix_flags |= SMB_O_DIRECT;
  95
  96         return posix_flags;
  97 }
  98
  99 static inline int cifs_get_disposition(unsigned int flags)
 100 {
 101         if ((flags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
 102                 return FILE_CREATE;
 103         else if ((flags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
 104                 return FILE_OVERWRITE_IF;
 105         else if ((flags & O_CREAT) == O_CREAT)
 106                 return FILE_OPEN_IF;
 107         else if ((flags & O_TRUNC) == O_TRUNC)
 108                 return FILE_OVERWRITE;
 109         else
 110                 return FILE_OPEN;
 111 }
 112
 113 int cifs_posix_open(char *full_path, struct inode **pinode,
 114                         struct super_block *sb, int mode, unsigned int f_flags,
 115                         __u32 *poplock, __u16 *pnetfid, unsigned int xid)
 116 {
 117         int rc;
 118         FILE_UNIX_BASIC_INFO *presp_data;
 119         __u32 posix_flags = 0;
 120         struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
 121         struct cifs_fattr fattr;
 122         struct tcon_link *tlink;
 123         struct cifs_tcon *tcon;
 124
 125         cifs_dbg(FYI, "posix open %s\n", full_path);
 126
 127         presp_data = kzalloc(sizeof(FILE_UNIX_BASIC_INFO), GFP_KERNEL);
 128         if (presp_data == NULL)
 129                 return -ENOMEM;
 130
 131         tlink = cifs_sb_tlink(cifs_sb);
 132         if (IS_ERR(tlink)) {
 133                 rc = PTR_ERR(tlink);
 134                 goto posix_open_ret;
 135         }
 136
 137         tcon = tlink_tcon(tlink);
 138         mode &= ~current_umask();
 139
 140         posix_flags = cifs_posix_convert_flags(f_flags);
 141         rc = CIFSPOSIXCreate(xid, tcon, posix_flags, mode, pnetfid, presp_data,
 142                              poplock, full_path, cifs_sb->local_nls,
 143                              cifs_remap(cifs_sb));
 144         cifs_put_tlink(tlink);
 145
 146         if (rc)
 147                 goto posix_open_ret;
 148
 149         if (presp_data->Type == cpu_to_le32(-1))
 150                 goto posix_open_ret; /* open ok, caller does qpathinfo */
 151
 152         if (!pinode)
 153                 goto posix_open_ret; /* caller does not need info */
 154
 155         cifs_unix_basic_to_fattr(&fattr, presp_data, cifs_sb);
 156
 157         /* get new inode and set it up */
 158         if (*pinode == NULL) {
 159                 cifs_fill_uniqueid(sb, &fattr);
 160                 *pinode = cifs_iget(sb, &fattr);
 161                 if (!*pinode) {
 162                         rc = -ENOMEM;
 163                         goto posix_open_ret;
 164                 }
 165         } else {
 166                 cifs_fattr_to_inode(*pinode, &fattr);
 167         }
 168
 169 posix_open_ret:
 170         kfree(presp_data);
 171         return rc;
 172 }
 173
 174 static int
 175 cifs_nt_open(char *full_path, struct inode *inode, struct cifs_sb_info *cifs_sb,
 176              struct cifs_tcon *tcon, unsigned int f_flags, __u32 *oplock,
 177              struct cifs_fid *fid, unsigned int xid)
 178 {
 179         int rc;
 180         int desired_access;
 181         int disposition;
 182         int create_options = CREATE_NOT_DIR;
 183         FILE_ALL_INFO *buf;
 184         struct TCP_Server_Info *server = tcon->ses->server;
 185         struct cifs_open_parms oparms;
 186
 187         if (!server->ops->open)
 188                 return -ENOSYS;
 189
 190         desired_access = cifs_convert_flags(f_flags);
 191
 192 /*********************************************************************
 193  *  open flag mapping table:
 194  *
 195  *      POSIX Flag            CIFS Disposition
 196  *      ----------            ----------------
 197  *      O_CREAT               FILE_OPEN_IF
 198  *      O_CREAT | O_EXCL      FILE_CREATE
 199  *      O_CREAT | O_TRUNC     FILE_OVERWRITE_IF
 200  *      O_TRUNC               FILE_OVERWRITE
 201  *      none of the above     FILE_OPEN
 202  *
 203  *      Note that there is not a direct match between disposition
 204  *      FILE_SUPERSEDE (ie create whether or not file exists although
 205  *      O_CREAT | O_TRUNC is similar but truncates the existing
 206  *      file rather than creating a new file as FILE_SUPERSEDE does
 207  *      (which uses the attributes / metadata passed in on open call)
 208  *?
 209  *?  O_SYNC is a reasonable match to CIFS writethrough flag
 210  *?  and the read write flags match reasonably.  O_LARGEFILE
 211  *?  is irrelevant because largefile support is always used
 212  *?  by this client. Flags O_APPEND, O_DIRECT, O_DIRECTORY,
 213  *       O_FASYNC, O_NOFOLLOW, O_NONBLOCK need further investigation
 214  *********************************************************************/
 215
 216         disposition = cifs_get_disposition(f_flags);
 217
 218         /* BB pass O_SYNC flag through on file attributes .. BB */
 219
 220         buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
 221         if (!buf)
 222                 return -ENOMEM;
 223
 224         if (backup_cred(cifs_sb))
 225                 create_options |= CREATE_OPEN_BACKUP_INTENT;
 226
 227         oparms.tcon = tcon;
 228         oparms.cifs_sb = cifs_sb;
 229         oparms.desired_access = desired_access;
 230         oparms.create_options = create_options;
 231         oparms.disposition = disposition;
 232         oparms.path = full_path;
 233         oparms.fid = fid;
 234         oparms.reconnect = false;
 235
 236         rc = server->ops->open(xid, &oparms, oplock, buf);
 237
 238         if (rc)
 239                 goto out;
 240
 241         if (tcon->unix_ext)
 242                 rc = cifs_get_inode_info_unix(&inode, full_path, inode->i_sb,
 243                                               xid);
 244         else
 245                 rc = cifs_get_inode_info(&inode, full_path, buf, inode->i_sb,
 246                                          xid, fid);
 247
 248 out:
 249         kfree(buf);
 250         return rc;
 251 }
 252
 253 static bool
 254 cifs_has_mand_locks(struct cifsInodeInfo *cinode)
 255 {
 256         struct cifs_fid_locks *cur;
 257         bool has_locks = false;
 258
 259         down_read(&cinode->lock_sem);
 260         list_for_each_entry(cur, &cinode->llist, llist) {
 261                 if (!list_empty(&cur->locks)) {
 262                         has_locks = true;
 263                         break;
 264                 }
 265         }
 266         up_read(&cinode->lock_sem);
 267         return has_locks;
 268 }
 269
 270 struct cifsFileInfo *
 271 cifs_new_fileinfo(struct cifs_fid *fid, struct file *file,
 272                   struct tcon_link *tlink, __u32 oplock)
 273 {
 274         struct dentry *dentry = file_dentry(file);
 275         struct inode *inode = d_inode(dentry);
 276         struct cifsInodeInfo *cinode = CIFS_I(inode);
 277         struct cifsFileInfo *cfile;
 278         struct cifs_fid_locks *fdlocks;
 279         struct cifs_tcon *tcon = tlink_tcon(tlink);
 280         struct TCP_Server_Info *server = tcon->ses->server;
 281
 282         cfile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
 283         if (cfile == NULL)
 284                 return cfile;
 285
 286         fdlocks = kzalloc(sizeof(struct cifs_fid_locks), GFP_KERNEL);
 287         if (!fdlocks) {
 288                 kfree(cfile);
 289                 return NULL;
 290         }
 291
 292         INIT_LIST_HEAD(&fdlocks->locks);
 293         fdlocks->cfile = cfile;
 294         cfile->llist = fdlocks;
 295         down_write(&cinode->lock_sem);
 296         list_add(&fdlocks->llist, &cinode->llist);
 297         up_write(&cinode->lock_sem);
 298
 299         cfile->count = 1;
 300         cfile->pid = current->tgid;
 301         cfile->uid = current_fsuid();
 302         cfile->dentry = dget(dentry);
 303         cfile->f_flags = file->f_flags;
 304         cfile->invalidHandle = false;
 305         cfile->tlink = cifs_get_tlink(tlink);
 306         INIT_WORK(&cfile->oplock_break, cifs_oplock_break);
 307         mutex_init(&cfile->fh_mutex);
 308         spin_lock_init(&cfile->file_info_lock);
 309
 310         cifs_sb_active(inode->i_sb);
 311
 312         /*
 313          * If the server returned a read oplock and we have mandatory brlocks,
 314          * set oplock level to None.
 315          */
 316         if (server->ops->is_read_op(oplock) && cifs_has_mand_locks(cinode)) {
 317                 cifs_dbg(FYI, "Reset oplock val from read to None due to mand locks\n");
 318                 oplock = 0;
 319         }
 320
 321         spin_lock(&tcon->open_file_lock);
 322         if (fid->pending_open->oplock != CIFS_OPLOCK_NO_CHANGE && oplock)
 323                 oplock = fid->pending_open->oplock;
 324         list_del(&fid->pending_open->olist);
 325
 326         fid->purge_cache = false;
 327         server->ops->set_fid(cfile, fid, oplock);
 328
 329         list_add(&cfile->tlist, &tcon->openFileList);
 330
 331         /* if readable file instance put first in list*/
 332         if (file->f_mode & FMODE_READ)
 333                 list_add(&cfile->flist, &cinode->openFileList);
 334         else
 335                 list_add_tail(&cfile->flist, &cinode->openFileList);
 336         spin_unlock(&tcon->open_file_lock);
 337
 338         if (fid->purge_cache)
 339                 cifs_zap_mapping(inode);
 340
 341         file->private_data = cfile;
 342         return cfile;
 343 }
 344
 345 struct cifsFileInfo *
 346 cifsFileInfo_get(struct cifsFileInfo *cifs_file)
 347 {
 348         spin_lock(&cifs_file->file_info_lock);
 349         cifsFileInfo_get_locked(cifs_file);
 350         spin_unlock(&cifs_file->file_info_lock);
 351         return cifs_file;
 352 }
 353
 354 /*
 355  * Release a reference on the file private data. This may involve closing
 356  * the filehandle out on the server. Must be called without holding
 357  * tcon->open_file_lock and cifs_file->file_info_lock.
 358  */
 359 void cifsFileInfo_put(struct cifsFileInfo *cifs_file)
 360 {
 361         struct inode *inode = d_inode(cifs_file->dentry);
 362         struct cifs_tcon *tcon = tlink_tcon(cifs_file->tlink);
 363         struct TCP_Server_Info *server = tcon->ses->server;
 364         struct cifsInodeInfo *cifsi = CIFS_I(inode);
 365         struct super_block *sb = inode->i_sb;
 366         struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
 367         struct cifsLockInfo *li, *tmp;
 368         struct cifs_fid fid;
 369         struct cifs_pending_open open;
 370         bool oplock_break_cancelled;
 371
 372         spin_lock(&tcon->open_file_lock);
 373
 374         spin_lock(&cifs_file->file_info_lock);
 375         if (--cifs_file->count > 0) {
 376                 spin_unlock(&cifs_file->file_info_lock);
 377                 spin_unlock(&tcon->open_file_lock);
 378                 return;
 379         }
 380         spin_unlock(&cifs_file->file_info_lock);
 381
 382         if (server->ops->get_lease_key)
 383                 server->ops->get_lease_key(inode, &fid);
 384
 385         /* store open in pending opens to make sure we don't miss lease break */
 386         cifs_add_pending_open_locked(&fid, cifs_file->tlink, &open);
 387
 388         /* remove it from the lists */
 389         list_del(&cifs_file->flist);
 390         list_del(&cifs_file->tlist);
 391
 392         if (list_empty(&cifsi->openFileList)) {
 393                 cifs_dbg(FYI, "closing last open instance for inode %p\n",
 394                          d_inode(cifs_file->dentry));
 395                 /*
 396                  * In strict cache mode we need invalidate mapping on the last
 397                  * close  because it may cause a error when we open this file
 398                  * again and get at least level II oplock.
 399                  */
 400                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_STRICT_IO)
 401                         set_bit(CIFS_INO_INVALID_MAPPING, &cifsi->flags);
 402                 cifs_set_oplock_level(cifsi, 0);
 403         }
 404
 405         spin_unlock(&tcon->open_file_lock);
 406
 407         oplock_break_cancelled = cancel_work_sync(&cifs_file->oplock_break);
 408
 409         if (!tcon->need_reconnect && !cifs_file->invalidHandle) {
 410                 struct TCP_Server_Info *server = tcon->ses->server;
 411                 unsigned int xid;
 412
 413                 xid = get_xid();
 414                 if (server->ops->close)
 415                         server->ops->close(xid, tcon, &cifs_file->fid);
 416                 _free_xid(xid);
 417         }
 418
 419         if (oplock_break_cancelled)
 420                 cifs_done_oplock_break(cifsi);
 421
 422         cifs_del_pending_open(&open);
 423
 424         /*
 425          * Delete any outstanding lock records. We'll lose them when the file
 426          * is closed anyway.
 427          */
 428         down_write(&cifsi->lock_sem);
 429         list_for_each_entry_safe(li, tmp, &cifs_file->llist->locks, llist) {
 430                 list_del(&li->llist);
 431                 cifs_del_lock_waiters(li);
 432                 kfree(li);
 433         }
 434         list_del(&cifs_file->llist->llist);
 435         kfree(cifs_file->llist);
 436         up_write(&cifsi->lock_sem);
 437
 438         cifs_put_tlink(cifs_file->tlink);
 439         dput(cifs_file->dentry);
 440         cifs_sb_deactive(sb);
 441         kfree(cifs_file);
 442 }
 443
 444 int cifs_open(struct inode *inode, struct file *file)
 445
 446 {
 447         int rc = -EACCES;
 448         unsigned int xid;
 449         __u32 oplock;
 450         struct cifs_sb_info *cifs_sb;
 451         struct TCP_Server_Info *server;
 452         struct cifs_tcon *tcon;
 453         struct tcon_link *tlink;
 454         struct cifsFileInfo *cfile = NULL;
 455         char *full_path = NULL;
 456         bool posix_open_ok = false;
 457         struct cifs_fid fid;
 458         struct cifs_pending_open open;
 459
 460         xid = get_xid();
 461
 462         cifs_sb = CIFS_SB(inode->i_sb);
 463         tlink = cifs_sb_tlink(cifs_sb);
 464         if (IS_ERR(tlink)) {
 465                 free_xid(xid);
 466                 return PTR_ERR(tlink);
 467         }
 468         tcon = tlink_tcon(tlink);
 469         server = tcon->ses->server;
 470
 471         full_path = build_path_from_dentry(file_dentry(file));
 472         if (full_path == NULL) {
 473                 rc = -ENOMEM;
 474                 goto out;
 475         }
 476
 477         cifs_dbg(FYI, "inode = 0x%p file flags are 0x%x for %s\n",
 478                  inode, file->f_flags, full_path);
 479
 480         if (file->f_flags & O_DIRECT &&
 481             cifs_sb->mnt_cifs_flags & CIFS_MOUNT_STRICT_IO) {
 482                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_BRL)
 483                         file->f_op = &cifs_file_direct_nobrl_ops;
 484                 else
 485                         file->f_op = &cifs_file_direct_ops;
 486         }
 487
 488         if (server->oplocks)
 489                 oplock = REQ_OPLOCK;
 490         else
 491                 oplock = 0;
 492
 493         if (!tcon->broken_posix_open && tcon->unix_ext &&
 494             cap_unix(tcon->ses) && (CIFS_UNIX_POSIX_PATH_OPS_CAP &
 495                                 le64_to_cpu(tcon->fsUnixInfo.Capability))) {
 496                 /* can not refresh inode info since size could be stale */
 497                 rc = cifs_posix_open(full_path, &inode, inode->i_sb,
 498                                 cifs_sb->mnt_file_mode /* ignored */,
 499                                 file->f_flags, &oplock, &fid.netfid, xid);
 500                 if (rc == 0) {
 501                         cifs_dbg(FYI, "posix open succeeded\n");
 502                         posix_open_ok = true;
 503                 } else if ((rc == -EINVAL) || (rc == -EOPNOTSUPP)) {
 504                         if (tcon->ses->serverNOS)
 505                                 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",
 506                                          tcon->ses->serverName,
 507                                          tcon->ses->serverNOS);
 508                         tcon->broken_posix_open = true;
 509                 } else if ((rc != -EIO) && (rc != -EREMOTE) &&
 510                          (rc != -EOPNOTSUPP)) /* path not found or net err */
 511                         goto out;
 512                 /*
 513                  * Else fallthrough to retry open the old way on network i/o
 514                  * or DFS errors.
 515                  */
 516         }
 517
 518         if (server->ops->get_lease_key)
 519                 server->ops->get_lease_key(inode, &fid);
 520
 521         cifs_add_pending_open(&fid, tlink, &open);
 522
 523         if (!posix_open_ok) {
 524                 if (server->ops->get_lease_key)
 525                         server->ops->get_lease_key(inode, &fid);
 526
 527                 rc = cifs_nt_open(full_path, inode, cifs_sb, tcon,
 528                                   file->f_flags, &oplock, &fid, xid);
 529                 if (rc) {
 530                         cifs_del_pending_open(&open);
 531                         goto out;
 532                 }
 533         }
 534
 535         cfile = cifs_new_fileinfo(&fid, file, tlink, oplock);
 536         if (cfile == NULL) {
 537                 if (server->ops->close)
 538                         server->ops->close(xid, tcon, &fid);
 539                 cifs_del_pending_open(&open);
 540                 rc = -ENOMEM;
 541                 goto out;
 542         }
 543
 544         cifs_fscache_set_inode_cookie(inode, file);
 545
 546         if ((oplock & CIFS_CREATE_ACTION) && !posix_open_ok && tcon->unix_ext) {
 547                 /*
 548                  * Time to set mode which we can not set earlier due to
 549                  * problems creating new read-only files.
 550                  */
 551                 struct cifs_unix_set_info_args args = {
 552                         .mode   = inode->i_mode,
 553                         .uid    = INVALID_UID, /* no change */
 554                         .gid    = INVALID_GID, /* no change */
 555                         .ctime  = NO_CHANGE_64,
 556                         .atime  = NO_CHANGE_64,
 557                         .mtime  = NO_CHANGE_64,
 558                         .device = 0,
 559                 };
 560                 CIFSSMBUnixSetFileInfo(xid, tcon, &args, fid.netfid,
 561                                        cfile->pid);
 562         }
 563
 564 out:
 565         kfree(full_path);
 566         free_xid(xid);
 567         cifs_put_tlink(tlink);
 568         return rc;
 569 }
 570
 571 static int cifs_push_posix_locks(struct cifsFileInfo *cfile);
 572
 573 /*
 574  * Try to reacquire byte range locks that were released when session
 575  * to server was lost.
 576  */
 577 static int
 578 cifs_relock_file(struct cifsFileInfo *cfile)
 579 {
 580         struct cifs_sb_info *cifs_sb = CIFS_SB(cfile->dentry->d_sb);
 581         struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
 582         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
 583         int rc = 0;
 584
 585         down_read(&cinode->lock_sem);
 586         if (cinode->can_cache_brlcks) {
 587                 /* can cache locks - no need to relock */
 588                 up_read(&cinode->lock_sem);
 589                 return rc;
 590         }
 591
 592         if (cap_unix(tcon->ses) &&
 593             (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
 594             ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
 595                 rc = cifs_push_posix_locks(cfile);
 596         else
 597                 rc = tcon->ses->server->ops->push_mand_locks(cfile);
 598
 599         up_read(&cinode->lock_sem);
 600         return rc;
 601 }
 602
 603 static int
 604 cifs_reopen_file(struct cifsFileInfo *cfile, bool can_flush)
 605 {
 606         int rc = -EACCES;
 607         unsigned int xid;
 608         __u32 oplock;
 609         struct cifs_sb_info *cifs_sb;
 610         struct cifs_tcon *tcon;
 611         struct TCP_Server_Info *server;
 612         struct cifsInodeInfo *cinode;
 613         struct inode *inode;
 614         char *full_path = NULL;
 615         int desired_access;
 616         int disposition = FILE_OPEN;
 617         int create_options = CREATE_NOT_DIR;
 618         struct cifs_open_parms oparms;
 619
 620         xid = get_xid();
 621         mutex_lock(&cfile->fh_mutex);
 622         if (!cfile->invalidHandle) {
 623                 mutex_unlock(&cfile->fh_mutex);
 624                 rc = 0;
 625                 free_xid(xid);
 626                 return rc;
 627         }
 628
 629         inode = d_inode(cfile->dentry);
 630         cifs_sb = CIFS_SB(inode->i_sb);
 631         tcon = tlink_tcon(cfile->tlink);
 632         server = tcon->ses->server;
 633
 634         /*
 635          * Can not grab rename sem here because various ops, including those
 636          * that already have the rename sem can end up causing writepage to get
 637          * called and if the server was down that means we end up here, and we
 638          * can never tell if the caller already has the rename_sem.
 639          */
 640         full_path = build_path_from_dentry(cfile->dentry);
 641         if (full_path == NULL) {
 642                 rc = -ENOMEM;
 643                 mutex_unlock(&cfile->fh_mutex);
 644                 free_xid(xid);
 645                 return rc;
 646         }
 647
 648         cifs_dbg(FYI, "inode = 0x%p file flags 0x%x for %s\n",
 649                  inode, cfile->f_flags, full_path);
 650
 651         if (tcon->ses->server->oplocks)
 652                 oplock = REQ_OPLOCK;
 653         else
 654                 oplock = 0;
 655
 656         if (tcon->unix_ext && cap_unix(tcon->ses) &&
 657             (CIFS_UNIX_POSIX_PATH_OPS_CAP &
 658                                 le64_to_cpu(tcon->fsUnixInfo.Capability))) {
 659                 /*
 660                  * O_CREAT, O_EXCL and O_TRUNC already had their effect on the
 661                  * original open. Must mask them off for a reopen.
 662                  */
 663                 unsigned int oflags = cfile->f_flags &
 664                                                 ~(O_CREAT | O_EXCL | O_TRUNC);
 665
 666                 rc = cifs_posix_open(full_path, NULL, inode->i_sb,
 667                                      cifs_sb->mnt_file_mode /* ignored */,
 668                                      oflags, &oplock, &cfile->fid.netfid, xid);
 669                 if (rc == 0) {
 670                         cifs_dbg(FYI, "posix reopen succeeded\n");
 671                         oparms.reconnect = true;
 672                         goto reopen_success;
 673                 }
 674                 /*
 675                  * fallthrough to retry open the old way on errors, especially
 676                  * in the reconnect path it is important to retry hard
 677                  */
 678         }
 679
 680         desired_access = cifs_convert_flags(cfile->f_flags);
 681
 682         if (backup_cred(cifs_sb))
 683                 create_options |= CREATE_OPEN_BACKUP_INTENT;
 684
 685         if (server->ops->get_lease_key)
 686                 server->ops->get_lease_key(inode, &cfile->fid);
 687
 688         oparms.tcon = tcon;
 689         oparms.cifs_sb = cifs_sb;
 690         oparms.desired_access = desired_access;
 691         oparms.create_options = create_options;
 692         oparms.disposition = disposition;
 693         oparms.path = full_path;
 694         oparms.fid = &cfile->fid;
 695         oparms.reconnect = true;
 696
 697         /*
 698          * Can not refresh inode by passing in file_info buf to be returned by
 699          * ops->open and then calling get_inode_info with returned buf since
 700          * file might have write behind data that needs to be flushed and server
 701          * version of file size can be stale. If we knew for sure that inode was
 702          * not dirty locally we could do this.
 703          */
 704         rc = server->ops->open(xid, &oparms, &oplock, NULL);
 705         if (rc == -ENOENT && oparms.reconnect == false) {
 706                 /* durable handle timeout is expired - open the file again */
 707                 rc = server->ops->open(xid, &oparms, &oplock, NULL);
 708                 /* indicate that we need to relock the file */
 709                 oparms.reconnect = true;
 710         }
 711
 712         if (rc) {
 713                 mutex_unlock(&cfile->fh_mutex);
 714                 cifs_dbg(FYI, "cifs_reopen returned 0x%x\n", rc);
 715                 cifs_dbg(FYI, "oplock: %d\n", oplock);
 716                 goto reopen_error_exit;
 717         }
 718
 719 reopen_success:
 720         cfile->invalidHandle = false;
 721         mutex_unlock(&cfile->fh_mutex);
 722         cinode = CIFS_I(inode);
 723
 724         if (can_flush) {
 725                 rc = filemap_write_and_wait(inode->i_mapping);
 726                 mapping_set_error(inode->i_mapping, rc);
 727
 728                 if (tcon->unix_ext)
 729                         rc = cifs_get_inode_info_unix(&inode, full_path,
 730                                                       inode->i_sb, xid);
 731                 else
 732                         rc = cifs_get_inode_info(&inode, full_path, NULL,
 733                                                  inode->i_sb, xid, NULL);
 734         }
 735         /*
 736          * Else we are writing out data to server already and could deadlock if
 737          * we tried to flush data, and since we do not know if we have data that
 738          * would invalidate the current end of file on the server we can not go
 739          * to the server to get the new inode info.
 740          */
 741
 742         /*
 743          * If the server returned a read oplock and we have mandatory brlocks,
 744          * set oplock level to None.
 745          */
 746         if (server->ops->is_read_op(oplock) && cifs_has_mand_locks(cinode)) {
 747                 cifs_dbg(FYI, "Reset oplock val from read to None due to mand locks\n");
 748                 oplock = 0;
 749         }
 750
 751         server->ops->set_fid(cfile, &cfile->fid, oplock);
 752         if (oparms.reconnect)
 753                 cifs_relock_file(cfile);
 754
 755 reopen_error_exit:
 756         kfree(full_path);
 757         free_xid(xid);
 758         return rc;
 759 }
 760
 761 int cifs_close(struct inode *inode, struct file *file)
 762 {
 763         if (file->private_data != NULL) {
 764                 cifsFileInfo_put(file->private_data);
 765                 file->private_data = NULL;
 766         }
 767
 768         /* return code from the ->release op is always ignored */
 769         return 0;
 770 }
 771
 772 void
 773 cifs_reopen_persistent_handles(struct cifs_tcon *tcon)
 774 {
 775         struct cifsFileInfo *open_file;
 776         struct list_head *tmp;
 777         struct list_head *tmp1;
 778         struct list_head tmp_list;
 779
 780         if (!tcon->use_persistent || !tcon->need_reopen_files)
 781                 return;
 782
 783         tcon->need_reopen_files = false;
 784
 785         cifs_dbg(FYI, "Reopen persistent handles");
 786         INIT_LIST_HEAD(&tmp_list);
 787
 788         /* list all files open on tree connection, reopen resilient handles  */
 789         spin_lock(&tcon->open_file_lock);
 790         list_for_each(tmp, &tcon->openFileList) {
 791                 open_file = list_entry(tmp, struct cifsFileInfo, tlist);
 792                 if (!open_file->invalidHandle)
 793                         continue;
 794                 cifsFileInfo_get(open_file);
 795                 list_add_tail(&open_file->rlist, &tmp_list);
 796         }
 797         spin_unlock(&tcon->open_file_lock);
 798
 799         list_for_each_safe(tmp, tmp1, &tmp_list) {
 800                 open_file = list_entry(tmp, struct cifsFileInfo, rlist);
 801                 if (cifs_reopen_file(open_file, false /* do not flush */))
 802                         tcon->need_reopen_files = true;
 803                 list_del_init(&open_file->rlist);
 804                 cifsFileInfo_put(open_file);
 805         }
 806 }
 807
 808 int cifs_closedir(struct inode *inode, struct file *file)
 809 {
 810         int rc = 0;
 811         unsigned int xid;
 812         struct cifsFileInfo *cfile = file->private_data;
 813         struct cifs_tcon *tcon;
 814         struct TCP_Server_Info *server;
 815         char *buf;
 816
 817         cifs_dbg(FYI, "Closedir inode = 0x%p\n", inode);
 818
 819         if (cfile == NULL)
 820                 return rc;
 821
 822         xid = get_xid();
 823         tcon = tlink_tcon(cfile->tlink);
 824         server = tcon->ses->server;
 825
 826         cifs_dbg(FYI, "Freeing private data in close dir\n");
 827         spin_lock(&cfile->file_info_lock);
 828         if (server->ops->dir_needs_close(cfile)) {
 829                 cfile->invalidHandle = true;
 830                 spin_unlock(&cfile->file_info_lock);
 831                 if (server->ops->close_dir)
 832                         rc = server->ops->close_dir(xid, tcon, &cfile->fid);
 833                 else
 834                         rc = -ENOSYS;
 835                 cifs_dbg(FYI, "Closing uncompleted readdir with rc %d\n", rc);
 836                 /* not much we can do if it fails anyway, ignore rc */
 837                 rc = 0;
 838         } else
 839                 spin_unlock(&cfile->file_info_lock);
 840
 841         buf = cfile->srch_inf.ntwrk_buf_start;
 842         if (buf) {
 843                 cifs_dbg(FYI, "closedir free smb buf in srch struct\n");
 844                 cfile->srch_inf.ntwrk_buf_start = NULL;
 845                 if (cfile->srch_inf.smallBuf)
 846                         cifs_small_buf_release(buf);
 847                 else
 848                         cifs_buf_release(buf);
 849         }
 850
 851         cifs_put_tlink(cfile->tlink);
 852         kfree(file->private_data);
 853         file->private_data = NULL;
 854         /* BB can we lock the filestruct while this is going on? */
 855         free_xid(xid);
 856         return rc;
 857 }
 858
 859 static struct cifsLockInfo *
 860 cifs_lock_init(__u64 offset, __u64 length, __u8 type)
 861 {
 862         struct cifsLockInfo *lock =
 863                 kmalloc(sizeof(struct cifsLockInfo), GFP_KERNEL);
 864         if (!lock)
 865                 return lock;
 866         lock->offset = offset;
 867         lock->length = length;
 868         lock->type = type;
 869         lock->pid = current->tgid;
 870         INIT_LIST_HEAD(&lock->blist);
 871         init_waitqueue_head(&lock->block_q);
 872         return lock;
 873 }
 874
 875 void
 876 cifs_del_lock_waiters(struct cifsLockInfo *lock)
 877 {
 878         struct cifsLockInfo *li, *tmp;
 879         list_for_each_entry_safe(li, tmp, &lock->blist, blist) {
 880                 list_del_init(&li->blist);
 881                 wake_up(&li->block_q);
 882         }
 883 }
 884
 885 #define CIFS_LOCK_OP    0
 886 #define CIFS_READ_OP    1
 887 #define CIFS_WRITE_OP   2
 888
 889 /* @rw_check : 0 - no op, 1 - read, 2 - write */
 890 static bool
 891 cifs_find_fid_lock_conflict(struct cifs_fid_locks *fdlocks, __u64 offset,
 892                             __u64 length, __u8 type, struct cifsFileInfo *cfile,
 893                             struct cifsLockInfo **conf_lock, int rw_check)
 894 {
 895         struct cifsLockInfo *li;
 896         struct cifsFileInfo *cur_cfile = fdlocks->cfile;
 897         struct TCP_Server_Info *server = tlink_tcon(cfile->tlink)->ses->server;
 898
 899         list_for_each_entry(li, &fdlocks->locks, llist) {
 900                 if (offset + length <= li->offset ||
 901                     offset >= li->offset + li->length)
 902                         continue;
 903                 if (rw_check != CIFS_LOCK_OP && current->tgid == li->pid &&
 904                     server->ops->compare_fids(cfile, cur_cfile)) {
 905                         /* shared lock prevents write op through the same fid */
 906                         if (!(li->type & server->vals->shared_lock_type) ||
 907                             rw_check != CIFS_WRITE_OP)
 908                                 continue;
 909                 }
 910                 if ((type & server->vals->shared_lock_type) &&
 911                     ((server->ops->compare_fids(cfile, cur_cfile) &&
 912                      current->tgid == li->pid) || type == li->type))
 913                         continue;
 914                 if (conf_lock)
 915                         *conf_lock = li;
 916                 return true;
 917         }
 918         return false;
 919 }
 920
 921 bool
 922 cifs_find_lock_conflict(struct cifsFileInfo *cfile, __u64 offset, __u64 length,
 923                         __u8 type, struct cifsLockInfo **conf_lock,
 924                         int rw_check)
 925 {
 926         bool rc = false;
 927         struct cifs_fid_locks *cur;
 928         struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
 929
 930         list_for_each_entry(cur, &cinode->llist, llist) {
 931                 rc = cifs_find_fid_lock_conflict(cur, offset, length, type,
 932                                                  cfile, conf_lock, rw_check);
 933                 if (rc)
 934                         break;
 935         }
 936
 937         return rc;
 938 }
 939
 940 /*
 941  * Check if there is another lock that prevents us to set the lock (mandatory
 942  * style). If such a lock exists, update the flock structure with its
 943  * properties. Otherwise, set the flock type to F_UNLCK if we can cache brlocks
 944  * or leave it the same if we can't. Returns 0 if we don't need to request to
 945  * the server or 1 otherwise.
 946  */
 947 static int
 948 cifs_lock_test(struct cifsFileInfo *cfile, __u64 offset, __u64 length,
 949                __u8 type, struct file_lock *flock)
 950 {
 951         int rc = 0;
 952         struct cifsLockInfo *conf_lock;
 953         struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
 954         struct TCP_Server_Info *server = tlink_tcon(cfile->tlink)->ses->server;
 955         bool exist;
 956
 957         down_read(&cinode->lock_sem);
 958
 959         exist = cifs_find_lock_conflict(cfile, offset, length, type,
 960                                         &conf_lock, CIFS_LOCK_OP);
 961         if (exist) {
 962                 flock->fl_start = conf_lock->offset;
 963                 flock->fl_end = conf_lock->offset + conf_lock->length - 1;
 964                 flock->fl_pid = conf_lock->pid;
 965                 if (conf_lock->type & server->vals->shared_lock_type)
 966                         flock->fl_type = F_RDLCK;
 967                 else
 968                         flock->fl_type = F_WRLCK;
 969         } else if (!cinode->can_cache_brlcks)
 970                 rc = 1;
 971         else
 972                 flock->fl_type = F_UNLCK;
 973
 974         up_read(&cinode->lock_sem);
 975         return rc;
 976 }
 977
 978 static void
 979 cifs_lock_add(struct cifsFileInfo *cfile, struct cifsLockInfo *lock)
 980 {
 981         struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
 982         down_write(&cinode->lock_sem);
 983         list_add_tail(&lock->llist, &cfile->llist->locks);
 984         up_write(&cinode->lock_sem);
 985 }
 986
 987 /*
 988  * Set the byte-range lock (mandatory style). Returns:
 989  * 1) 0, if we set the lock and don't need to request to the server;
 990  * 2) 1, if no locks prevent us but we need to request to the server;
 991  * 3) -EACCESS, if there is a lock that prevents us and wait is false.
 992  */
 993 static int
 994 cifs_lock_add_if(struct cifsFileInfo *cfile, struct cifsLockInfo *lock,
 995                  bool wait)
 996 {
 997         struct cifsLockInfo *conf_lock;
 998         struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
 999         bool exist;
1000         int rc = 0;
1001
1002 try_again:
1003         exist = false;
1004         down_write(&cinode->lock_sem);
1005
1006         exist = cifs_find_lock_conflict(cfile, lock->offset, lock->length,
1007                                         lock->type, &conf_lock, CIFS_LOCK_OP);
1008         if (!exist && cinode->can_cache_brlcks) {
1009                 list_add_tail(&lock->llist, &cfile->llist->locks);
1010                 up_write(&cinode->lock_sem);
1011                 return rc;
1012         }
1013
1014         if (!exist)
1015                 rc = 1;
1016         else if (!wait)
1017                 rc = -EACCES;
1018         else {
1019                 list_add_tail(&lock->blist, &conf_lock->blist);
1020                 up_write(&cinode->lock_sem);
1021                 rc = wait_event_interruptible(lock->block_q,
1022                                         (lock->blist.prev == &lock->blist) &&
1023                                         (lock->blist.next == &lock->blist));
1024                 if (!rc)
1025                         goto try_again;
1026                 down_write(&cinode->lock_sem);
1027                 list_del_init(&lock->blist);
1028         }
1029
1030         up_write(&cinode->lock_sem);
1031         return rc;
1032 }
1033
1034 /*
1035  * Check if there is another lock that prevents us to set the lock (posix
1036  * style). If such a lock exists, update the flock structure with its
1037  * properties. Otherwise, set the flock type to F_UNLCK if we can cache brlocks
1038  * or leave it the same if we can't. Returns 0 if we don't need to request to
1039  * the server or 1 otherwise.
1040  */
1041 static int
1042 cifs_posix_lock_test(struct file *file, struct file_lock *flock)
1043 {
1044         int rc = 0;
1045         struct cifsInodeInfo *cinode = CIFS_I(file_inode(file));
1046         unsigned char saved_type = flock->fl_type;
1047
1048         if ((flock->fl_flags & FL_POSIX) == 0)
1049                 return 1;
1050
1051         down_read(&cinode->lock_sem);
1052         posix_test_lock(file, flock);
1053
1054         if (flock->fl_type == F_UNLCK && !cinode->can_cache_brlcks) {
1055                 flock->fl_type = saved_type;
1056                 rc = 1;
1057         }
1058
1059         up_read(&cinode->lock_sem);
1060         return rc;
1061 }
1062
1063 /*
1064  * Set the byte-range lock (posix style). Returns:
1065  * 1) 0, if we set the lock and don't need to request to the server;
1066  * 2) 1, if we need to request to the server;
1067  * 3) <0, if the error occurs while setting the lock.
1068  */
1069 static int
1070 cifs_posix_lock_set(struct file *file, struct file_lock *flock)
1071 {
1072         struct cifsInodeInfo *cinode = CIFS_I(file_inode(file));
1073         int rc = 1;
1074
1075         if ((flock->fl_flags & FL_POSIX) == 0)
1076                 return rc;
1077
1078 try_again:
1079         down_write(&cinode->lock_sem);
1080         if (!cinode->can_cache_brlcks) {
1081                 up_write(&cinode->lock_sem);
1082                 return rc;
1083         }
1084
1085         rc = posix_lock_file(file, flock, NULL);
1086         up_write(&cinode->lock_sem);
1087         if (rc == FILE_LOCK_DEFERRED) {
1088                 rc = wait_event_interruptible(flock->fl_wait, !flock->fl_next);
1089                 if (!rc)
1090                         goto try_again;
1091                 posix_unblock_lock(flock);
1092         }
1093         return rc;
1094 }
1095
1096 int
1097 cifs_push_mandatory_locks(struct cifsFileInfo *cfile)
1098 {
1099         unsigned int xid;
1100         int rc = 0, stored_rc;
1101         struct cifsLockInfo *li, *tmp;
1102         struct cifs_tcon *tcon;
1103         unsigned int num, max_num, max_buf;
1104         LOCKING_ANDX_RANGE *buf, *cur;
1105         int types[] = {LOCKING_ANDX_LARGE_FILES,
1106                        LOCKING_ANDX_SHARED_LOCK | LOCKING_ANDX_LARGE_FILES};
1107         int i;
1108
1109         xid = get_xid();
1110         tcon = tlink_tcon(cfile->tlink);
1111
1112         /*
1113          * Accessing maxBuf is racy with cifs_reconnect - need to store value
1114          * and check it for zero before using.
1115          */
1116         max_buf = tcon->ses->server->maxBuf;
1117         if (!max_buf) {
1118                 free_xid(xid);
1119                 return -EINVAL;
1120         }
1121
1122         max_num = (max_buf - sizeof(struct smb_hdr)) /
1123                                                 sizeof(LOCKING_ANDX_RANGE);
1124         buf = kcalloc(max_num, sizeof(LOCKING_ANDX_RANGE), GFP_KERNEL);
1125         if (!buf) {
1126                 free_xid(xid);
1127                 return -ENOMEM;
1128         }
1129
1130         for (i = 0; i < 2; i++) {
1131                 cur = buf;
1132                 num = 0;
1133                 list_for_each_entry_safe(li, tmp, &cfile->llist->locks, llist) {
1134                         if (li->type != types[i])
1135                                 continue;
1136                         cur->Pid = cpu_to_le16(li->pid);
1137                         cur->LengthLow = cpu_to_le32((u32)li->length);
1138                         cur->LengthHigh = cpu_to_le32((u32)(li->length>>32));
1139                         cur->OffsetLow = cpu_to_le32((u32)li->offset);
1140                         cur->OffsetHigh = cpu_to_le32((u32)(li->offset>>32));
1141                         if (++num == max_num) {
1142                                 stored_rc = cifs_lockv(xid, tcon,
1143                                                        cfile->fid.netfid,
1144                                                        (__u8)li->type, 0, num,
1145                                                        buf);
1146                                 if (stored_rc)
1147                                         rc = stored_rc;
1148                                 cur = buf;
1149                                 num = 0;
1150                         } else
1151                                 cur++;
1152                 }
1153
1154                 if (num) {
1155                         stored_rc = cifs_lockv(xid, tcon, cfile->fid.netfid,
1156                                                (__u8)types[i], 0, num, buf);
1157                         if (stored_rc)
1158                                 rc = stored_rc;
1159                 }
1160         }
1161
1162         kfree(buf);
1163         free_xid(xid);
1164         return rc;
1165 }
1166
1167 static __u32
1168 hash_lockowner(fl_owner_t owner)
1169 {
1170         return cifs_lock_secret ^ hash32_ptr((const void *)owner);
1171 }
1172
1173 struct lock_to_push {
1174         struct list_head llist;
1175         __u64 offset;
1176         __u64 length;
1177         __u32 pid;
1178         __u16 netfid;
1179         __u8 type;
1180 };
1181
1182 static int
1183 cifs_push_posix_locks(struct cifsFileInfo *cfile)
1184 {
1185         struct inode *inode = d_inode(cfile->dentry);
1186         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1187         struct file_lock *flock;
1188         struct file_lock_context *flctx = inode->i_flctx;
1189         unsigned int count = 0, i;
1190         int rc = 0, xid, type;
1191         struct list_head locks_to_send, *el;
1192         struct lock_to_push *lck, *tmp;
1193         __u64 length;
1194
1195         xid = get_xid();
1196
1197         if (!flctx)
1198                 goto out;
1199
1200         spin_lock(&flctx->flc_lock);
1201         list_for_each(el, &flctx->flc_posix) {
1202                 count++;
1203         }
1204         spin_unlock(&flctx->flc_lock);
1205
1206         INIT_LIST_HEAD(&locks_to_send);
1207
1208         /*
1209          * Allocating count locks is enough because no FL_POSIX locks can be
1210          * added to the list while we are holding cinode->lock_sem that
1211          * protects locking operations of this inode.
1212          */
1213         for (i = 0; i < count; i++) {
1214                 lck = kmalloc(sizeof(struct lock_to_push), GFP_KERNEL);
1215                 if (!lck) {
1216                         rc = -ENOMEM;
1217                         goto err_out;
1218                 }
1219                 list_add_tail(&lck->llist, &locks_to_send);
1220         }
1221
1222         el = locks_to_send.next;
1223         spin_lock(&flctx->flc_lock);
1224         list_for_each_entry(flock, &flctx->flc_posix, fl_list) {
1225                 if (el == &locks_to_send) {
1226                         /*
1227                          * The list ended. We don't have enough allocated
1228                          * structures - something is really wrong.
1229                          */
1230                         cifs_dbg(VFS, "Can't push all brlocks!\n");
1231                         break;
1232                 }
1233                 length = 1 + flock->fl_end - flock->fl_start;
1234                 if (flock->fl_type == F_RDLCK || flock->fl_type == F_SHLCK)
1235                         type = CIFS_RDLCK;
1236                 else
1237                         type = CIFS_WRLCK;
1238                 lck = list_entry(el, struct lock_to_push, llist);
1239                 lck->pid = hash_lockowner(flock->fl_owner);
1240                 lck->netfid = cfile->fid.netfid;
1241                 lck->length = length;
1242                 lck->type = type;
1243                 lck->offset = flock->fl_start;
1244         }
1245         spin_unlock(&flctx->flc_lock);
1246
1247         list_for_each_entry_safe(lck, tmp, &locks_to_send, llist) {
1248                 int stored_rc;
1249
1250                 stored_rc = CIFSSMBPosixLock(xid, tcon, lck->netfid, lck->pid,
1251                                              lck->offset, lck->length, NULL,
1252                                              lck->type, 0);
1253                 if (stored_rc)
1254                         rc = stored_rc;
1255                 list_del(&lck->llist);
1256                 kfree(lck);
1257         }
1258
1259 out:
1260         free_xid(xid);
1261         return rc;
1262 err_out:
1263         list_for_each_entry_safe(lck, tmp, &locks_to_send, llist) {
1264                 list_del(&lck->llist);
1265                 kfree(lck);
1266         }
1267         goto out;
1268 }
1269
1270 static int
1271 cifs_push_locks(struct cifsFileInfo *cfile)
1272 {
1273         struct cifs_sb_info *cifs_sb = CIFS_SB(cfile->dentry->d_sb);
1274         struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
1275         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1276         int rc = 0;
1277
1278         /* we are going to update can_cache_brlcks here - need a write access */
1279         down_write(&cinode->lock_sem);
1280         if (!cinode->can_cache_brlcks) {
1281                 up_write(&cinode->lock_sem);
1282                 return rc;
1283         }
1284
1285         if (cap_unix(tcon->ses) &&
1286             (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
1287             ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
1288                 rc = cifs_push_posix_locks(cfile);
1289         else
1290                 rc = tcon->ses->server->ops->push_mand_locks(cfile);
1291
1292         cinode->can_cache_brlcks = false;
1293         up_write(&cinode->lock_sem);
1294         return rc;
1295 }
1296
1297 static void
1298 cifs_read_flock(struct file_lock *flock, __u32 *type, int *lock, int *unlock,
1299                 bool *wait_flag, struct TCP_Server_Info *server)
1300 {
1301         if (flock->fl_flags & FL_POSIX)
1302                 cifs_dbg(FYI, "Posix\n");
1303         if (flock->fl_flags & FL_FLOCK)
1304                 cifs_dbg(FYI, "Flock\n");
1305         if (flock->fl_flags & FL_SLEEP) {
1306                 cifs_dbg(FYI, "Blocking lock\n");
1307                 *wait_flag = true;
1308         }
1309         if (flock->fl_flags & FL_ACCESS)
1310                 cifs_dbg(FYI, "Process suspended by mandatory locking - not implemented yet\n");
1311         if (flock->fl_flags & FL_LEASE)
1312                 cifs_dbg(FYI, "Lease on file - not implemented yet\n");
1313         if (flock->fl_flags &
1314             (~(FL_POSIX | FL_FLOCK | FL_SLEEP |
1315                FL_ACCESS | FL_LEASE | FL_CLOSE)))
1316                 cifs_dbg(FYI, "Unknown lock flags 0x%x\n", flock->fl_flags);
1317
1318         *type = server->vals->large_lock_type;
1319         if (flock->fl_type == F_WRLCK) {
1320                 cifs_dbg(FYI, "F_WRLCK\n");
1321                 *type |= server->vals->exclusive_lock_type;
1322                 *lock = 1;
1323         } else if (flock->fl_type == F_UNLCK) {
1324                 cifs_dbg(FYI, "F_UNLCK\n");
1325                 *type |= server->vals->unlock_lock_type;
1326                 *unlock = 1;
1327                 /* Check if unlock includes more than one lock range */
1328         } else if (flock->fl_type == F_RDLCK) {
1329                 cifs_dbg(FYI, "F_RDLCK\n");
1330                 *type |= server->vals->shared_lock_type;
1331                 *lock = 1;
1332         } else if (flock->fl_type == F_EXLCK) {
1333                 cifs_dbg(FYI, "F_EXLCK\n");
1334                 *type |= server->vals->exclusive_lock_type;
1335                 *lock = 1;
1336         } else if (flock->fl_type == F_SHLCK) {
1337                 cifs_dbg(FYI, "F_SHLCK\n");
1338                 *type |= server->vals->shared_lock_type;
1339                 *lock = 1;
1340         } else
1341                 cifs_dbg(FYI, "Unknown type of lock\n");
1342 }
1343
1344 static int
1345 cifs_getlk(struct file *file, struct file_lock *flock, __u32 type,
1346            bool wait_flag, bool posix_lck, unsigned int xid)
1347 {
1348         int rc = 0;
1349         __u64 length = 1 + flock->fl_end - flock->fl_start;
1350         struct cifsFileInfo *cfile = (struct cifsFileInfo *)file->private_data;
1351         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1352         struct TCP_Server_Info *server = tcon->ses->server;
1353         __u16 netfid = cfile->fid.netfid;
1354
1355         if (posix_lck) {
1356                 int posix_lock_type;
1357
1358                 rc = cifs_posix_lock_test(file, flock);
1359                 if (!rc)
1360                         return rc;
1361
1362                 if (type & server->vals->shared_lock_type)
1363                         posix_lock_type = CIFS_RDLCK;
1364                 else
1365                         posix_lock_type = CIFS_WRLCK;
1366                 rc = CIFSSMBPosixLock(xid, tcon, netfid,
1367                                       hash_lockowner(flock->fl_owner),
1368                                       flock->fl_start, length, flock,
1369                                       posix_lock_type, wait_flag);
1370                 return rc;
1371         }
1372
1373         rc = cifs_lock_test(cfile, flock->fl_start, length, type, flock);
1374         if (!rc)
1375                 return rc;
1376
1377         /* BB we could chain these into one lock request BB */
1378         rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length, type,
1379                                     1, 0, false);
1380         if (rc == 0) {
1381                 rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length,
1382                                             type, 0, 1, false);
1383                 flock->fl_type = F_UNLCK;
1384                 if (rc != 0)
1385                         cifs_dbg(VFS, "Error unlocking previously locked range %d during test of lock\n",
1386                                  rc);
1387                 return 0;
1388         }
1389
1390         if (type & server->vals->shared_lock_type) {
1391                 flock->fl_type = F_WRLCK;
1392                 return 0;
1393         }
1394
1395         type &= ~server->vals->exclusive_lock_type;
1396
1397         rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length,
1398                                     type | server->vals->shared_lock_type,
1399                                     1, 0, false);
1400         if (rc == 0) {
1401                 rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length,
1402                         type | server->vals->shared_lock_type, 0, 1, false);
1403                 flock->fl_type = F_RDLCK;
1404                 if (rc != 0)
1405                         cifs_dbg(VFS, "Error unlocking previously locked range %d during test of lock\n",
1406                                  rc);
1407         } else
1408                 flock->fl_type = F_WRLCK;
1409
1410         return 0;
1411 }
1412
1413 void
1414 cifs_move_llist(struct list_head *source, struct list_head *dest)
1415 {
1416         struct list_head *li, *tmp;
1417         list_for_each_safe(li, tmp, source)
1418                 list_move(li, dest);
1419 }
1420
1421 void
1422 cifs_free_llist(struct list_head *llist)
1423 {
1424         struct cifsLockInfo *li, *tmp;
1425         list_for_each_entry_safe(li, tmp, llist, llist) {
1426                 cifs_del_lock_waiters(li);
1427                 list_del(&li->llist);
1428                 kfree(li);
1429         }
1430 }
1431
1432 int
1433 cifs_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock,
1434                   unsigned int xid)
1435 {
1436         int rc = 0, stored_rc;
1437         int types[] = {LOCKING_ANDX_LARGE_FILES,
1438                        LOCKING_ANDX_SHARED_LOCK | LOCKING_ANDX_LARGE_FILES};
1439         unsigned int i;
1440         unsigned int max_num, num, max_buf;
1441         LOCKING_ANDX_RANGE *buf, *cur;
1442         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1443         struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
1444         struct cifsLockInfo *li, *tmp;
1445         __u64 length = 1 + flock->fl_end - flock->fl_start;
1446         struct list_head tmp_llist;
1447
1448         INIT_LIST_HEAD(&tmp_llist);
1449
1450         /*
1451          * Accessing maxBuf is racy with cifs_reconnect - need to store value
1452          * and check it for zero before using.
1453          */
1454         max_buf = tcon->ses->server->maxBuf;
1455         if (!max_buf)
1456                 return -EINVAL;
1457
1458         max_num = (max_buf - sizeof(struct smb_hdr)) /
1459                                                 sizeof(LOCKING_ANDX_RANGE);
1460         buf = kcalloc(max_num, sizeof(LOCKING_ANDX_RANGE), GFP_KERNEL);
1461         if (!buf)
1462                 return -ENOMEM;
1463
1464         down_write(&cinode->lock_sem);
1465         for (i = 0; i < 2; i++) {
1466                 cur = buf;
1467                 num = 0;
1468                 list_for_each_entry_safe(li, tmp, &cfile->llist->locks, llist) {
1469                         if (flock->fl_start > li->offset ||
1470                             (flock->fl_start + length) <
1471                             (li->offset + li->length))
1472                                 continue;
1473                         if (current->tgid != li->pid)
1474                                 continue;
1475                         if (types[i] != li->type)
1476                                 continue;
1477                         if (cinode->can_cache_brlcks) {
1478                                 /*
1479                                  * We can cache brlock requests - simply remove
1480                                  * a lock from the file's list.
1481                                  */
1482                                 list_del(&li->llist);
1483                                 cifs_del_lock_waiters(li);
1484                                 kfree(li);
1485                                 continue;
1486                         }
1487                         cur->Pid = cpu_to_le16(li->pid);
1488                         cur->LengthLow = cpu_to_le32((u32)li->length);
1489                         cur->LengthHigh = cpu_to_le32((u32)(li->length>>32));
1490                         cur->OffsetLow = cpu_to_le32((u32)li->offset);
1491                         cur->OffsetHigh = cpu_to_le32((u32)(li->offset>>32));
1492                         /*
1493                          * We need to save a lock here to let us add it again to
1494                          * the file's list if the unlock range request fails on
1495                          * the server.
1496                          */
1497                         list_move(&li->llist, &tmp_llist);
1498                         if (++num == max_num) {
1499                                 stored_rc = cifs_lockv(xid, tcon,
1500                                                        cfile->fid.netfid,
1501                                                        li->type, num, 0, buf);
1502                                 if (stored_rc) {
1503                                         /*
1504                                          * We failed on the unlock range
1505                                          * request - add all locks from the tmp
1506                                          * list to the head of the file's list.
1507                                          */
1508                                         cifs_move_llist(&tmp_llist,
1509                                                         &cfile->llist->locks);
1510                                         rc = stored_rc;
1511                                 } else
1512                                         /*
1513                                          * The unlock range request succeed -
1514                                          * free the tmp list.
1515                                          */
1516                                         cifs_free_llist(&tmp_llist);
1517                                 cur = buf;
1518                                 num = 0;
1519                         } else
1520                                 cur++;
1521                 }
1522                 if (num) {
1523                         stored_rc = cifs_lockv(xid, tcon, cfile->fid.netfid,
1524                                                types[i], num, 0, buf);
1525                         if (stored_rc) {
1526                                 cifs_move_llist(&tmp_llist,
1527                                                 &cfile->llist->locks);
1528                                 rc = stored_rc;
1529                         } else
1530                                 cifs_free_llist(&tmp_llist);
1531                 }
1532         }
1533
1534         up_write(&cinode->lock_sem);
1535         kfree(buf);
1536         return rc;
1537 }
1538
1539 static int
1540 cifs_setlk(struct file *file, struct file_lock *flock, __u32 type,
1541            bool wait_flag, bool posix_lck, int lock, int unlock,
1542            unsigned int xid)
1543 {
1544         int rc = 0;
1545         __u64 length = 1 + flock->fl_end - flock->fl_start;
1546         struct cifsFileInfo *cfile = (struct cifsFileInfo *)file->private_data;
1547         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1548         struct TCP_Server_Info *server = tcon->ses->server;
1549         struct inode *inode = d_inode(cfile->dentry);
1550
1551         if (posix_lck) {
1552                 int posix_lock_type;
1553
1554                 rc = cifs_posix_lock_set(file, flock);
1555                 if (!rc || rc < 0)
1556                         return rc;
1557
1558                 if (type & server->vals->shared_lock_type)
1559                         posix_lock_type = CIFS_RDLCK;
1560                 else
1561                         posix_lock_type = CIFS_WRLCK;
1562
1563                 if (unlock == 1)
1564                         posix_lock_type = CIFS_UNLCK;
1565
1566                 rc = CIFSSMBPosixLock(xid, tcon, cfile->fid.netfid,
1567                                       hash_lockowner(flock->fl_owner),
1568                                       flock->fl_start, length,
1569                                       NULL, posix_lock_type, wait_flag);
1570                 goto out;
1571         }
1572
1573         if (lock) {
1574                 struct cifsLockInfo *lock;
1575
1576                 lock = cifs_lock_init(flock->fl_start, length, type);
1577                 if (!lock)
1578                         return -ENOMEM;
1579
1580                 rc = cifs_lock_add_if(cfile, lock, wait_flag);
1581                 if (rc < 0) {
1582                         kfree(lock);
1583                         return rc;
1584                 }
1585                 if (!rc)
1586                         goto out;
1587
1588                 /*
1589                  * Windows 7 server can delay breaking lease from read to None
1590                  * if we set a byte-range lock on a file - break it explicitly
1591                  * before sending the lock to the server to be sure the next
1592                  * read won't conflict with non-overlapted locks due to
1593                  * pagereading.
1594                  */
1595                 if (!CIFS_CACHE_WRITE(CIFS_I(inode)) &&
1596                                         CIFS_CACHE_READ(CIFS_I(inode))) {
1597                         cifs_zap_mapping(inode);
1598                         cifs_dbg(FYI, "Set no oplock for inode=%p due to mand locks\n",
1599                                  inode);
1600                         CIFS_I(inode)->oplock = 0;
1601                 }
1602
1603                 rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length,
1604                                             type, 1, 0, wait_flag);
1605                 if (rc) {
1606                         kfree(lock);
1607                         return rc;
1608                 }
1609
1610                 cifs_lock_add(cfile, lock);
1611         } else if (unlock)
1612                 rc = server->ops->mand_unlock_range(cfile, flock, xid);
1613
1614 out:
1615         if (flock->fl_flags & FL_POSIX && !rc)
1616                 rc = locks_lock_file_wait(file, flock);
1617         return rc;
1618 }
1619
1620 int cifs_lock(struct file *file, int cmd, struct file_lock *flock)
1621 {
1622         int rc, xid;
1623         int lock = 0, unlock = 0;
1624         bool wait_flag = false;
1625         bool posix_lck = false;
1626         struct cifs_sb_info *cifs_sb;
1627         struct cifs_tcon *tcon;
1628         struct cifsInodeInfo *cinode;
1629         struct cifsFileInfo *cfile;
1630         __u16 netfid;
1631         __u32 type;
1632
1633         rc = -EACCES;
1634         xid = get_xid();
1635
1636         cifs_dbg(FYI, "Lock parm: 0x%x flockflags: 0x%x flocktype: 0x%x start: %lld end: %lld\n",
1637                  cmd, flock->fl_flags, flock->fl_type,
1638                  flock->fl_start, flock->fl_end);
1639
1640         cfile = (struct cifsFileInfo *)file->private_data;
1641         tcon = tlink_tcon(cfile->tlink);
1642
1643         cifs_read_flock(flock, &type, &lock, &unlock, &wait_flag,
1644                         tcon->ses->server);
1645
1646         cifs_sb = CIFS_FILE_SB(file);
1647         netfid = cfile->fid.netfid;
1648         cinode = CIFS_I(file_inode(file));
1649
1650         if (cap_unix(tcon->ses) &&
1651             (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
1652             ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
1653                 posix_lck = true;
1654         /*
1655          * BB add code here to normalize offset and length to account for
1656          * negative length which we can not accept over the wire.
1657          */
1658         if (IS_GETLK(cmd)) {
1659                 rc = cifs_getlk(file, flock, type, wait_flag, posix_lck, xid);
1660                 free_xid(xid);
1661                 return rc;
1662         }
1663
1664         if (!lock && !unlock) {
1665                 /*
1666                  * if no lock or unlock then nothing to do since we do not
1667                  * know what it is
1668                  */
1669                 free_xid(xid);
1670                 return -EOPNOTSUPP;
1671         }
1672
1673         rc = cifs_setlk(file, flock, type, wait_flag, posix_lck, lock, unlock,
1674                         xid);
1675         free_xid(xid);
1676         return rc;
1677 }
1678
1679 /*
1680  * update the file size (if needed) after a write. Should be called with
1681  * the inode->i_lock held
1682  */
1683 void
1684 cifs_update_eof(struct cifsInodeInfo *cifsi, loff_t offset,
1685                       unsigned int bytes_written)
1686 {
1687         loff_t end_of_write = offset + bytes_written;
1688
1689         if (end_of_write > cifsi->server_eof)
1690                 cifsi->server_eof = end_of_write;
1691 }
1692
1693 static ssize_t
1694 cifs_write(struct cifsFileInfo *open_file, __u32 pid, const char *write_data,
1695            size_t write_size, loff_t *offset)
1696 {
1697         int rc = 0;
1698         unsigned int bytes_written = 0;
1699         unsigned int total_written;
1700         struct cifs_sb_info *cifs_sb;
1701         struct cifs_tcon *tcon;
1702         struct TCP_Server_Info *server;
1703         unsigned int xid;
1704         struct dentry *dentry = open_file->dentry;
1705         struct cifsInodeInfo *cifsi = CIFS_I(d_inode(dentry));
1706         struct cifs_io_parms io_parms;
1707
1708         cifs_sb = CIFS_SB(dentry->d_sb);
1709
1710         cifs_dbg(FYI, "write %zd bytes to offset %lld of %pd\n",
1711                  write_size, *offset, dentry);
1712
1713         tcon = tlink_tcon(open_file->tlink);
1714         server = tcon->ses->server;
1715
1716         if (!server->ops->sync_write)
1717                 return -ENOSYS;
1718
1719         xid = get_xid();
1720
1721         for (total_written = 0; write_size > total_written;
1722              total_written += bytes_written) {
1723                 rc = -EAGAIN;
1724                 while (rc == -EAGAIN) {
1725                         struct kvec iov[2];
1726                         unsigned int len;
1727
1728                         if (open_file->invalidHandle) {
1729                                 /* we could deadlock if we called
1730                                    filemap_fdatawait from here so tell
1731                                    reopen_file not to flush data to
1732                                    server now */
1733                                 rc = cifs_reopen_file(open_file, false);
1734                                 if (rc != 0)
1735                                         break;
1736                         }
1737
1738                         len = min(server->ops->wp_retry_size(d_inode(dentry)),
1739                                   (unsigned int)write_size - total_written);
1740                         /* iov[0] is reserved for smb header */
1741                         iov[1].iov_base = (char *)write_data + total_written;
1742                         iov[1].iov_len = len;
1743                         io_parms.pid = pid;
1744                         io_parms.tcon = tcon;
1745                         io_parms.offset = *offset;
1746                         io_parms.length = len;
1747                         rc = server->ops->sync_write(xid, &open_file->fid,
1748                                         &io_parms, &bytes_written, iov, 1);
1749                 }
1750                 if (rc || (bytes_written == 0)) {
1751                         if (total_written)
1752                                 break;
1753                         else {
1754                                 free_xid(xid);
1755                                 return rc;
1756                         }
1757                 } else {
1758                         spin_lock(&d_inode(dentry)->i_lock);
1759                         cifs_update_eof(cifsi, *offset, bytes_written);
1760                         spin_unlock(&d_inode(dentry)->i_lock);
1761                         *offset += bytes_written;
1762                 }
1763         }
1764
1765         cifs_stats_bytes_written(tcon, total_written);
1766
1767         if (total_written > 0) {
1768                 spin_lock(&d_inode(dentry)->i_lock);
1769                 if (*offset > d_inode(dentry)->i_size)
1770                         i_size_write(d_inode(dentry), *offset);
1771                 spin_unlock(&d_inode(dentry)->i_lock);
1772         }
1773         mark_inode_dirty_sync(d_inode(dentry));
1774         free_xid(xid);
1775         return total_written;
1776 }
1777
1778 struct cifsFileInfo *find_readable_file(struct cifsInodeInfo *cifs_inode,
1779                                         bool fsuid_only)
1780 {
1781         struct cifsFileInfo *open_file = NULL;
1782         struct cifs_sb_info *cifs_sb = CIFS_SB(cifs_inode->vfs_inode.i_sb);
1783         struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
1784
1785         /* only filter by fsuid on multiuser mounts */
1786         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
1787                 fsuid_only = false;
1788
1789         spin_lock(&tcon->open_file_lock);
1790         /* we could simply get the first_list_entry since write-only entries
1791            are always at the end of the list but since the first entry might
1792            have a close pending, we go through the whole list */
1793         list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
1794                 if (fsuid_only && !uid_eq(open_file->uid, current_fsuid()))
1795                         continue;
1796                 if (OPEN_FMODE(open_file->f_flags) & FMODE_READ) {
1797                         if (!open_file->invalidHandle) {
1798                                 /* found a good file */
1799                                 /* lock it so it will not be closed on us */
1800                                 cifsFileInfo_get(open_file);
1801                                 spin_unlock(&tcon->open_file_lock);
1802                                 return open_file;
1803                         } /* else might as well continue, and look for
1804                              another, or simply have the caller reopen it
1805                              again rather than trying to fix this handle */
1806                 } else /* write only file */
1807                         break; /* write only files are last so must be done */
1808         }
1809         spin_unlock(&tcon->open_file_lock);
1810         return NULL;
1811 }
1812
1813 struct cifsFileInfo *find_writable_file(struct cifsInodeInfo *cifs_inode,
1814                                         bool fsuid_only)
1815 {
1816         struct cifsFileInfo *open_file, *inv_file = NULL;
1817         struct cifs_sb_info *cifs_sb;
1818         struct cifs_tcon *tcon;
1819         bool any_available = false;
1820         int rc;
1821         unsigned int refind = 0;
1822
1823         /* Having a null inode here (because mapping->host was set to zero by
1824         the VFS or MM) should not happen but we had reports of on oops (due to
1825         it being zero) during stress testcases so we need to check for it */
1826
1827         if (cifs_inode == NULL) {
1828                 cifs_dbg(VFS, "Null inode passed to cifs_writeable_file\n");
1829                 dump_stack();
1830                 return NULL;
1831         }
1832
1833         cifs_sb = CIFS_SB(cifs_inode->vfs_inode.i_sb);
1834         tcon = cifs_sb_master_tcon(cifs_sb);
1835
1836         /* only filter by fsuid on multiuser mounts */
1837         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
1838                 fsuid_only = false;
1839
1840         spin_lock(&tcon->open_file_lock);
1841 refind_writable:
1842         if (refind > MAX_REOPEN_ATT) {
1843                 spin_unlock(&tcon->open_file_lock);
1844                 return NULL;
1845         }
1846         list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
1847                 if (!any_available && open_file->pid != current->tgid)
1848                         continue;
1849                 if (fsuid_only && !uid_eq(open_file->uid, current_fsuid()))
1850                         continue;
1851                 if (OPEN_FMODE(open_file->f_flags) & FMODE_WRITE) {
1852                         if (!open_file->invalidHandle) {
1853                                 /* found a good writable file */
1854                                 cifsFileInfo_get(open_file);
1855                                 spin_unlock(&tcon->open_file_lock);
1856                                 return open_file;
1857                         } else {
1858                                 if (!inv_file)
1859                                         inv_file = open_file;
1860                         }
1861                 }
1862         }
1863         /* couldn't find useable FH with same pid, try any available */
1864         if (!any_available) {
1865                 any_available = true;
1866                 goto refind_writable;
1867         }
1868
1869         if (inv_file) {
1870                 any_available = false;
1871                 cifsFileInfo_get(inv_file);
1872         }
1873
1874         spin_unlock(&tcon->open_file_lock);
1875
1876         if (inv_file) {
1877                 rc = cifs_reopen_file(inv_file, false);
1878                 if (!rc)
1879                         return inv_file;
1880                 else {
1881                         spin_lock(&tcon->open_file_lock);
1882                         list_move_tail(&inv_file->flist,
1883                                         &cifs_inode->openFileList);
1884                         spin_unlock(&tcon->open_file_lock);
1885                         cifsFileInfo_put(inv_file);
1886                         ++refind;
1887                         inv_file = NULL;
1888                         spin_lock(&tcon->open_file_lock);
1889                         goto refind_writable;
1890                 }
1891         }
1892
1893         return NULL;
1894 }
1895
1896 static int cifs_partialpagewrite(struct page *page, unsigned from, unsigned to)
1897 {
1898         struct address_space *mapping = page->mapping;
1899         loff_t offset = (loff_t)page->index << PAGE_SHIFT;
1900         char *write_data;
1901         int rc = -EFAULT;
1902         int bytes_written = 0;
1903         struct inode *inode;
1904         struct cifsFileInfo *open_file;
1905
1906         if (!mapping || !mapping->host)
1907                 return -EFAULT;
1908
1909         inode = page->mapping->host;
1910
1911         offset += (loff_t)from;
1912         write_data = kmap(page);
1913         write_data += from;
1914
1915         if ((to > PAGE_SIZE) || (from > to)) {
1916                 kunmap(page);
1917                 return -EIO;
1918         }
1919
1920         /* racing with truncate? */
1921         if (offset > mapping->host->i_size) {
1922                 kunmap(page);
1923                 return 0; /* don't care */
1924         }
1925
1926         /* check to make sure that we are not extending the file */
1927         if (mapping->host->i_size - offset < (loff_t)to)
1928                 to = (unsigned)(mapping->host->i_size - offset);
1929
1930         open_file = find_writable_file(CIFS_I(mapping->host), false);
1931         if (open_file) {
1932                 bytes_written = cifs_write(open_file, open_file->pid,
1933                                            write_data, to - from, &offset);
1934                 cifsFileInfo_put(open_file);
1935                 /* Does mm or vfs already set times? */
1936                 inode->i_atime = inode->i_mtime = current_time(inode);
1937                 if ((bytes_written > 0) && (offset))
1938                         rc = 0;
1939                 else if (bytes_written < 0)
1940                         rc = bytes_written;
1941         } else {
1942                 cifs_dbg(FYI, "No writeable filehandles for inode\n");
1943                 rc = -EIO;
1944         }
1945
1946         kunmap(page);
1947         return rc;
1948 }
1949
1950 static struct cifs_writedata *
1951 wdata_alloc_and_fillpages(pgoff_t tofind, struct address_space *mapping,
1952                           pgoff_t end, pgoff_t *index,
1953                           unsigned int *found_pages)
1954 {
1955         unsigned int nr_pages;
1956         struct page **pages;
1957         struct cifs_writedata *wdata;
1958
1959         wdata = cifs_writedata_alloc((unsigned int)tofind,
1960                                      cifs_writev_complete);
1961         if (!wdata)
1962                 return NULL;
1963
1964         /*
1965          * find_get_pages_tag seems to return a max of 256 on each
1966          * iteration, so we must call it several times in order to
1967          * fill the array or the wsize is effectively limited to
1968          * 256 * PAGE_SIZE.
1969          */
1970         *found_pages = 0;
1971         pages = wdata->pages;
1972         do {
1973                 nr_pages = find_get_pages_tag(mapping, index,
1974                                               PAGECACHE_TAG_DIRTY, tofind,
1975                                               pages);
1976                 *found_pages += nr_pages;
1977                 tofind -= nr_pages;
1978                 pages += nr_pages;
1979         } while (nr_pages && tofind && *index <= end);
1980
1981         return wdata;
1982 }
1983
1984 static unsigned int
1985 wdata_prepare_pages(struct cifs_writedata *wdata, unsigned int found_pages,
1986                     struct address_space *mapping,
1987                     struct writeback_control *wbc,
1988                     pgoff_t end, pgoff_t *index, pgoff_t *next, bool *done)
1989 {
1990         unsigned int nr_pages = 0, i;
1991         struct page *page;
1992
1993         for (i = 0; i < found_pages; i++) {
1994                 page = wdata->pages[i];
1995                 /*
1996                  * At this point we hold neither mapping->tree_lock nor
1997                  * lock on the page itself: the page may be truncated or
1998                  * invalidated (changing page->mapping to NULL), or even
1999                  * swizzled back from swapper_space to tmpfs file
2000                  * mapping
2001                  */
2002
2003                 if (nr_pages == 0)
2004                         lock_page(page);
2005                 else if (!trylock_page(page))
2006                         break;
2007
2008                 if (unlikely(page->mapping != mapping)) {
2009                         unlock_page(page);
2010                         break;
2011                 }
2012
2013                 if (!wbc->range_cyclic && page->index > end) {
2014                         *done = true;
2015                         unlock_page(page);
2016                         break;
2017                 }
2018
2019                 if (*next && (page->index != *next)) {
2020                         /* Not next consecutive page */
2021                         unlock_page(page);
2022                         break;
2023                 }
2024
2025                 if (wbc->sync_mode != WB_SYNC_NONE)
2026                         wait_on_page_writeback(page);
2027
2028                 if (PageWriteback(page) ||
2029                                 !clear_page_dirty_for_io(page)) {
2030                         unlock_page(page);
2031                         break;
2032                 }
2033
2034                 /*
2035                  * This actually clears the dirty bit in the radix tree.
2036                  * See cifs_writepage() for more commentary.
2037                  */
2038                 set_page_writeback(page);
2039                 if (page_offset(page) >= i_size_read(mapping->host)) {
2040                         *done = true;
2041                         unlock_page(page);
2042                         end_page_writeback(page);
2043                         break;
2044                 }
2045
2046                 wdata->pages[i] = page;
2047                 *next = page->index + 1;
2048                 ++nr_pages;
2049         }
2050
2051         /* reset index to refind any pages skipped */
2052         if (nr_pages == 0)
2053                 *index = wdata->pages[0]->index + 1;
2054
2055         /* put any pages we aren't going to use */
2056         for (i = nr_pages; i < found_pages; i++) {
2057                 put_page(wdata->pages[i]);
2058                 wdata->pages[i] = NULL;
2059         }
2060
2061         return nr_pages;
2062 }
2063
2064 static int
2065 wdata_send_pages(struct cifs_writedata *wdata, unsigned int nr_pages,
2066                  struct address_space *mapping, struct writeback_control *wbc)
2067 {
2068         int rc = 0;
2069         struct TCP_Server_Info *server;
2070         unsigned int i;
2071
2072         wdata->sync_mode = wbc->sync_mode;
2073         wdata->nr_pages = nr_pages;
2074         wdata->offset = page_offset(wdata->pages[0]);
2075         wdata->pagesz = PAGE_SIZE;
2076         wdata->tailsz = min(i_size_read(mapping->host) -
2077                         page_offset(wdata->pages[nr_pages - 1]),
2078                         (loff_t)PAGE_SIZE);
2079         wdata->bytes = ((nr_pages - 1) * PAGE_SIZE) + wdata->tailsz;
2080
2081         if (wdata->cfile != NULL)
2082                 cifsFileInfo_put(wdata->cfile);
2083         wdata->cfile = find_writable_file(CIFS_I(mapping->host), false);
2084         if (!wdata->cfile) {
2085                 cifs_dbg(VFS, "No writable handles for inode\n");
2086                 rc = -EBADF;
2087         } else {
2088                 wdata->pid = wdata->cfile->pid;
2089                 server = tlink_tcon(wdata->cfile->tlink)->ses->server;
2090                 rc = server->ops->async_writev(wdata, cifs_writedata_release);
2091         }
2092
2093         for (i = 0; i < nr_pages; ++i)
2094                 unlock_page(wdata->pages[i]);
2095
2096         return rc;
2097 }
2098
2099 static int cifs_writepages(struct address_space *mapping,
2100                            struct writeback_control *wbc)
2101 {
2102         struct cifs_sb_info *cifs_sb = CIFS_SB(mapping->host->i_sb);
2103         struct TCP_Server_Info *server;
2104         bool done = false, scanned = false, range_whole = false;
2105         pgoff_t end, index;
2106         struct cifs_writedata *wdata;
2107         int rc = 0;
2108
2109         /*
2110          * If wsize is smaller than the page cache size, default to writing
2111          * one page at a time via cifs_writepage
2112          */
2113         if (cifs_sb->wsize < PAGE_SIZE)
2114                 return generic_writepages(mapping, wbc);
2115
2116         if (wbc->range_cyclic) {
2117                 index = mapping->writeback_index; /* Start from prev offset */
2118                 end = -1;
2119         } else {
2120                 index = wbc->range_start >> PAGE_SHIFT;
2121                 end = wbc->range_end >> PAGE_SHIFT;
2122                 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
2123                         range_whole = true;
2124                 scanned = true;
2125         }
2126         server = cifs_sb_master_tcon(cifs_sb)->ses->server;
2127 retry:
2128         while (!done && index <= end) {
2129                 unsigned int i, nr_pages, found_pages, wsize, credits;
2130                 pgoff_t next = 0, tofind, saved_index = index;
2131
2132                 rc = server->ops->wait_mtu_credits(server, cifs_sb->wsize,
2133                                                    &wsize, &credits);
2134                 if (rc)
2135                         break;
2136
2137                 tofind = min((wsize / PAGE_SIZE) - 1, end - index) + 1;
2138
2139                 wdata = wdata_alloc_and_fillpages(tofind, mapping, end, &index,
2140                                                   &found_pages);
2141                 if (!wdata) {
2142                         rc = -ENOMEM;
2143                         add_credits_and_wake_if(server, credits, 0);
2144                         break;
2145                 }
2146
2147                 if (found_pages == 0) {
2148                         kref_put(&wdata->refcount, cifs_writedata_release);
2149                         add_credits_and_wake_if(server, credits, 0);
2150                         break;
2151                 }
2152
2153                 nr_pages = wdata_prepare_pages(wdata, found_pages, mapping, wbc,
2154                                                end, &index, &next, &done);
2155
2156                 /* nothing to write? */
2157                 if (nr_pages == 0) {
2158                         kref_put(&wdata->refcount, cifs_writedata_release);
2159                         add_credits_and_wake_if(server, credits, 0);
2160                         continue;
2161                 }
2162
2163                 wdata->credits = credits;
2164
2165                 rc = wdata_send_pages(wdata, nr_pages, mapping, wbc);
2166
2167                 /* send failure -- clean up the mess */
2168                 if (rc != 0) {
2169                         add_credits_and_wake_if(server, wdata->credits, 0);
2170                         for (i = 0; i < nr_pages; ++i) {
2171                                 if (rc == -EAGAIN)
2172                                         redirty_page_for_writepage(wbc,
2173                                                            wdata->pages[i]);
2174                                 else
2175                                         SetPageError(wdata->pages[i]);
2176                                 end_page_writeback(wdata->pages[i]);
2177                                 put_page(wdata->pages[i]);
2178                         }
2179                         if (rc != -EAGAIN)
2180                                 mapping_set_error(mapping, rc);
2181                 }
2182                 kref_put(&wdata->refcount, cifs_writedata_release);
2183
2184                 if (wbc->sync_mode == WB_SYNC_ALL && rc == -EAGAIN) {
2185                         index = saved_index;
2186                         continue;
2187                 }
2188
2189                 wbc->nr_to_write -= nr_pages;
2190                 if (wbc->nr_to_write <= 0)
2191                         done = true;
2192
2193                 index = next;
2194         }
2195
2196         if (!scanned && !done) {
2197                 /*
2198                  * We hit the last page and there is more work to be done: wrap
2199                  * back to the start of the file
2200                  */
2201                 scanned = true;
2202                 index = 0;
2203                 goto retry;
2204         }
2205
2206         if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
2207                 mapping->writeback_index = index;
2208
2209         return rc;
2210 }
2211
2212 static int
2213 cifs_writepage_locked(struct page *page, struct writeback_control *wbc)
2214 {
2215         int rc;
2216         unsigned int xid;
2217
2218         xid = get_xid();
2219 /* BB add check for wbc flags */
2220         get_page(page);
2221         if (!PageUptodate(page))
2222                 cifs_dbg(FYI, "ppw - page not up to date\n");
2223
2224         /*
2225          * Set the "writeback" flag, and clear "dirty" in the radix tree.
2226          *
2227          * A writepage() implementation always needs to do either this,
2228          * or re-dirty the page with "redirty_page_for_writepage()" in
2229          * the case of a failure.
2230          *
2231          * Just unlocking the page will cause the radix tree tag-bits
2232          * to fail to update with the state of the page correctly.
2233          */
2234         set_page_writeback(page);
2235 retry_write:
2236         rc = cifs_partialpagewrite(page, 0, PAGE_SIZE);
2237         if (rc == -EAGAIN && wbc->sync_mode == WB_SYNC_ALL)
2238                 goto retry_write;
2239         else if (rc == -EAGAIN)
2240                 redirty_page_for_writepage(wbc, page);
2241         else if (rc != 0)
2242                 SetPageError(page);
2243         else
2244                 SetPageUptodate(page);
2245         end_page_writeback(page);
2246         put_page(page);
2247         free_xid(xid);
2248         return rc;
2249 }
2250
2251 static int cifs_writepage(struct page *page, struct writeback_control *wbc)
2252 {
2253         int rc = cifs_writepage_locked(page, wbc);
2254         unlock_page(page);
2255         return rc;
2256 }
2257
2258 static int cifs_write_end(struct file *file, struct address_space *mapping,
2259                         loff_t pos, unsigned len, unsigned copied,
2260                         struct page *page, void *fsdata)
2261 {
2262         int rc;
2263         struct inode *inode = mapping->host;
2264         struct cifsFileInfo *cfile = file->private_data;
2265         struct cifs_sb_info *cifs_sb = CIFS_SB(cfile->dentry->d_sb);
2266         __u32 pid;
2267
2268         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
2269                 pid = cfile->pid;
2270         else
2271                 pid = current->tgid;
2272
2273         cifs_dbg(FYI, "write_end for page %p from pos %lld with %d bytes\n",
2274                  page, pos, copied);
2275
2276         if (PageChecked(page)) {
2277                 if (copied == len)
2278                         SetPageUptodate(page);
2279                 ClearPageChecked(page);
2280         } else if (!PageUptodate(page) && copied == PAGE_SIZE)
2281                 SetPageUptodate(page);
2282
2283         if (!PageUptodate(page)) {
2284                 char *page_data;
2285                 unsigned offset = pos & (PAGE_SIZE - 1);
2286                 unsigned int xid;
2287
2288                 xid = get_xid();
2289                 /* this is probably better than directly calling
2290                    partialpage_write since in this function the file handle is
2291                    known which we might as well leverage */
2292                 /* BB check if anything else missing out of ppw
2293                    such as updating last write time */
2294                 page_data = kmap(page);
2295                 rc = cifs_write(cfile, pid, page_data + offset, copied, &pos);
2296                 /* if (rc < 0) should we set writebehind rc? */
2297                 kunmap(page);
2298
2299                 free_xid(xid);
2300         } else {
2301                 rc = copied;
2302                 pos += copied;
2303                 set_page_dirty(page);
2304         }
2305
2306         if (rc > 0) {
2307                 spin_lock(&inode->i_lock);
2308                 if (pos > inode->i_size)
2309                         i_size_write(inode, pos);
2310                 spin_unlock(&inode->i_lock);
2311         }
2312
2313         unlock_page(page);
2314         put_page(page);
2315
2316         return rc;
2317 }
2318
2319 int cifs_strict_fsync(struct file *file, loff_t start, loff_t end,
2320                       int datasync)
2321 {
2322         unsigned int xid;
2323         int rc = 0;
2324         struct cifs_tcon *tcon;
2325         struct TCP_Server_Info *server;
2326         struct cifsFileInfo *smbfile = file->private_data;
2327         struct inode *inode = file_inode(file);
2328         struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
2329
2330         rc = filemap_write_and_wait_range(inode->i_mapping, start, end);
2331         if (rc)
2332                 return rc;
2333         inode_lock(inode);
2334
2335         xid = get_xid();
2336
2337         cifs_dbg(FYI, "Sync file - name: %pD datasync: 0x%x\n",
2338                  file, datasync);
2339
2340         if (!CIFS_CACHE_READ(CIFS_I(inode))) {
2341                 rc = cifs_zap_mapping(inode);
2342                 if (rc) {
2343                         cifs_dbg(FYI, "rc: %d during invalidate phase\n", rc);
2344                         rc = 0; /* don't care about it in fsync */
2345                 }
2346         }
2347
2348         tcon = tlink_tcon(smbfile->tlink);
2349         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC)) {
2350                 server = tcon->ses->server;
2351                 if (server->ops->flush)
2352                         rc = server->ops->flush(xid, tcon, &smbfile->fid);
2353                 else
2354                         rc = -ENOSYS;
2355         }
2356
2357         free_xid(xid);
2358         inode_unlock(inode);
2359         return rc;
2360 }
2361
2362 int cifs_fsync(struct file *file, loff_t start, loff_t end, int datasync)
2363 {
2364         unsigned int xid;
2365         int rc = 0;
2366         struct cifs_tcon *tcon;
2367         struct TCP_Server_Info *server;
2368         struct cifsFileInfo *smbfile = file->private_data;
2369         struct cifs_sb_info *cifs_sb = CIFS_FILE_SB(file);
2370         struct inode *inode = file->f_mapping->host;
2371
2372         rc = filemap_write_and_wait_range(inode->i_mapping, start, end);
2373         if (rc)
2374                 return rc;
2375         inode_lock(inode);
2376
2377         xid = get_xid();
2378
2379         cifs_dbg(FYI, "Sync file - name: %pD datasync: 0x%x\n",
2380                  file, datasync);
2381
2382         tcon = tlink_tcon(smbfile->tlink);
2383         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC)) {
2384                 server = tcon->ses->server;
2385                 if (server->ops->flush)
2386                         rc = server->ops->flush(xid, tcon, &smbfile->fid);
2387                 else
2388                         rc = -ENOSYS;
2389         }
2390
2391         free_xid(xid);
2392         inode_unlock(inode);
2393         return rc;
2394 }
2395
2396 /*
2397  * As file closes, flush all cached write data for this inode checking
2398  * for write behind errors.
2399  */
2400 int cifs_flush(struct file *file, fl_owner_t id)
2401 {
2402         struct inode *inode = file_inode(file);
2403         int rc = 0;
2404
2405         if (file->f_mode & FMODE_WRITE)
2406                 rc = filemap_write_and_wait(inode->i_mapping);
2407
2408         cifs_dbg(FYI, "Flush inode %p file %p rc %d\n", inode, file, rc);
2409
2410         return rc;
2411 }
2412
2413 static int
2414 cifs_write_allocate_pages(struct page **pages, unsigned long num_pages)
2415 {
2416         int rc = 0;
2417         unsigned long i;
2418
2419         for (i = 0; i < num_pages; i++) {
2420                 pages[i] = alloc_page(GFP_KERNEL|__GFP_HIGHMEM);
2421                 if (!pages[i]) {
2422                         /*
2423                          * save number of pages we have already allocated and
2424                          * return with ENOMEM error
2425                          */
2426                         num_pages = i;
2427                         rc = -ENOMEM;
2428                         break;
2429                 }
2430         }
2431
2432         if (rc) {
2433                 for (i = 0; i < num_pages; i++)
2434                         put_page(pages[i]);
2435         }
2436         return rc;
2437 }
2438
2439 static inline
2440 size_t get_numpages(const size_t wsize, const size_t len, size_t *cur_len)
2441 {
2442         size_t num_pages;
2443         size_t clen;
2444
2445         clen = min_t(const size_t, len, wsize);
2446         num_pages = DIV_ROUND_UP(clen, PAGE_SIZE);
2447
2448         if (cur_len)
2449                 *cur_len = clen;
2450
2451         return num_pages;
2452 }
2453
2454 static void
2455 cifs_uncached_writedata_release(struct kref *refcount)
2456 {
2457         int i;
2458         struct cifs_writedata *wdata = container_of(refcount,
2459                                         struct cifs_writedata, refcount);
2460
2461         for (i = 0; i < wdata->nr_pages; i++)
2462                 put_page(wdata->pages[i]);
2463         cifs_writedata_release(refcount);
2464 }
2465
2466 static void
2467 cifs_uncached_writev_complete(struct work_struct *work)
2468 {
2469         struct cifs_writedata *wdata = container_of(work,
2470                                         struct cifs_writedata, work);
2471         struct inode *inode = d_inode(wdata->cfile->dentry);
2472         struct cifsInodeInfo *cifsi = CIFS_I(inode);
2473
2474         spin_lock(&inode->i_lock);
2475         cifs_update_eof(cifsi, wdata->offset, wdata->bytes);
2476         if (cifsi->server_eof > inode->i_size)
2477                 i_size_write(inode, cifsi->server_eof);
2478         spin_unlock(&inode->i_lock);
2479
2480         complete(&wdata->done);
2481
2482         kref_put(&wdata->refcount, cifs_uncached_writedata_release);
2483 }
2484
2485 static int
2486 wdata_fill_from_iovec(struct cifs_writedata *wdata, struct iov_iter *from,
2487                       size_t *len, unsigned long *num_pages)
2488 {
2489         size_t save_len, copied, bytes, cur_len = *len;
2490         unsigned long i, nr_pages = *num_pages;
2491
2492         save_len = cur_len;
2493         for (i = 0; i < nr_pages; i++) {
2494                 bytes = min_t(const size_t, cur_len, PAGE_SIZE);
2495                 copied = copy_page_from_iter(wdata->pages[i], 0, bytes, from);
2496                 cur_len -= copied;
2497                 /*
2498                  * If we didn't copy as much as we expected, then that
2499                  * may mean we trod into an unmapped area. Stop copying
2500                  * at that point. On the next pass through the big
2501                  * loop, we'll likely end up getting a zero-length
2502                  * write and bailing out of it.
2503                  */
2504                 if (copied < bytes)
2505                         break;
2506         }
2507         cur_len = save_len - cur_len;
2508         *len = cur_len;
2509
2510         /*
2511          * If we have no data to send, then that probably means that
2512          * the copy above failed altogether. That's most likely because
2513          * the address in the iovec was bogus. Return -EFAULT and let
2514          * the caller free anything we allocated and bail out.
2515          */
2516         if (!cur_len)
2517                 return -EFAULT;
2518
2519         /*
2520          * i + 1 now represents the number of pages we actually used in
2521          * the copy phase above.
2522          */
2523         *num_pages = i + 1;
2524         return 0;
2525 }
2526
2527 static int
2528 cifs_write_from_iter(loff_t offset, size_t len, struct iov_iter *from,
2529                      struct cifsFileInfo *open_file,
2530                      struct cifs_sb_info *cifs_sb, struct list_head *wdata_list)
2531 {
2532         int rc = 0;
2533         size_t cur_len;
2534         unsigned long nr_pages, num_pages, i;
2535         struct cifs_writedata *wdata;
2536         struct iov_iter saved_from = *from;
2537         loff_t saved_offset = offset;
2538         pid_t pid;
2539         struct TCP_Server_Info *server;
2540
2541         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
2542                 pid = open_file->pid;
2543         else
2544                 pid = current->tgid;
2545
2546         server = tlink_tcon(open_file->tlink)->ses->server;
2547
2548         do {
2549                 unsigned int wsize, credits;
2550
2551                 rc = server->ops->wait_mtu_credits(server, cifs_sb->wsize,
2552                                                    &wsize, &credits);
2553                 if (rc)
2554                         break;
2555
2556                 nr_pages = get_numpages(wsize, len, &cur_len);
2557                 wdata = cifs_writedata_alloc(nr_pages,
2558                                              cifs_uncached_writev_complete);
2559                 if (!wdata) {
2560                         rc = -ENOMEM;
2561                         add_credits_and_wake_if(server, credits, 0);
2562                         break;
2563                 }
2564
2565                 rc = cifs_write_allocate_pages(wdata->pages, nr_pages);
2566                 if (rc) {
2567                         kfree(wdata);
2568                         add_credits_and_wake_if(server, credits, 0);
2569                         break;
2570                 }
2571
2572                 num_pages = nr_pages;
2573                 rc = wdata_fill_from_iovec(wdata, from, &cur_len, &num_pages);
2574                 if (rc) {
2575                         for (i = 0; i < nr_pages; i++)
2576                                 put_page(wdata->pages[i]);
2577                         kfree(wdata);
2578                         add_credits_and_wake_if(server, credits, 0);
2579                         break;
2580                 }
2581
2582                 /*
2583                  * Bring nr_pages down to the number of pages we actually used,
2584                  * and free any pages that we didn't use.
2585                  */
2586                 for ( ; nr_pages > num_pages; nr_pages--)
2587                         put_page(wdata->pages[nr_pages - 1]);
2588
2589                 wdata->sync_mode = WB_SYNC_ALL;
2590                 wdata->nr_pages = nr_pages;
2591                 wdata->offset = (__u64)offset;
2592                 wdata->cfile = cifsFileInfo_get(open_file);
2593                 wdata->pid = pid;
2594                 wdata->bytes = cur_len;
2595                 wdata->pagesz = PAGE_SIZE;
2596                 wdata->tailsz = cur_len - ((nr_pages - 1) * PAGE_SIZE);
2597                 wdata->credits = credits;
2598
2599                 if (!wdata->cfile->invalidHandle ||
2600                     !cifs_reopen_file(wdata->cfile, false))
2601                         rc = server->ops->async_writev(wdata,
2602                                         cifs_uncached_writedata_release);
2603                 if (rc) {
2604                         add_credits_and_wake_if(server, wdata->credits, 0);
2605                         kref_put(&wdata->refcount,
2606                                  cifs_uncached_writedata_release);
2607                         if (rc == -EAGAIN) {
2608                                 *from = saved_from;
2609                                 iov_iter_advance(from, offset - saved_offset);
2610                                 continue;
2611                         }
2612                         break;
2613                 }
2614
2615                 list_add_tail(&wdata->list, wdata_list);
2616                 offset += cur_len;
2617                 len -= cur_len;
2618         } while (len > 0);
2619
2620         return rc;
2621 }
2622
2623 ssize_t cifs_user_writev(struct kiocb *iocb, struct iov_iter *from)
2624 {
2625         struct file *file = iocb->ki_filp;
2626         ssize_t total_written = 0;
2627         struct cifsFileInfo *open_file;
2628         struct cifs_tcon *tcon;
2629         struct cifs_sb_info *cifs_sb;
2630         struct cifs_writedata *wdata, *tmp;
2631         struct list_head wdata_list;
2632         struct iov_iter saved_from = *from;
2633         int rc;
2634
2635         /*
2636          * BB - optimize the way when signing is disabled. We can drop this
2637          * extra memory-to-memory copying and use iovec buffers for constructing
2638          * write request.
2639          */
2640
2641         rc = generic_write_checks(iocb, from);
2642         if (rc <= 0)
2643                 return rc;
2644
2645         INIT_LIST_HEAD(&wdata_list);
2646         cifs_sb = CIFS_FILE_SB(file);
2647         open_file = file->private_data;
2648         tcon = tlink_tcon(open_file->tlink);
2649
2650         if (!tcon->ses->server->ops->async_writev)
2651                 return -ENOSYS;
2652
2653         rc = cifs_write_from_iter(iocb->ki_pos, iov_iter_count(from), from,
2654                                   open_file, cifs_sb, &wdata_list);
2655
2656         /*
2657          * If at least one write was successfully sent, then discard any rc
2658          * value from the later writes. If the other write succeeds, then
2659          * we'll end up returning whatever was written. If it fails, then
2660          * we'll get a new rc value from that.
2661          */
2662         if (!list_empty(&wdata_list))
2663                 rc = 0;
2664
2665         /*
2666          * Wait for and collect replies for any successful sends in order of
2667          * increasing offset. Once an error is hit or we get a fatal signal
2668          * while waiting, then return without waiting for any more replies.
2669          */
2670 restart_loop:
2671         list_for_each_entry_safe(wdata, tmp, &wdata_list, list) {
2672                 if (!rc) {
2673                         /* FIXME: freezable too? */
2674                         rc = wait_for_completion_killable(&wdata->done);
2675                         if (rc)
2676                                 rc = -EINTR;
2677                         else if (wdata->result)
2678                                 rc = wdata->result;
2679                         else
2680                                 total_written += wdata->bytes;
2681
2682                         /* resend call if it's a retryable error */
2683                         if (rc == -EAGAIN) {
2684                                 struct list_head tmp_list;
2685                                 struct iov_iter tmp_from = saved_from;
2686
2687                                 INIT_LIST_HEAD(&tmp_list);
2688                                 list_del_init(&wdata->list);
2689
2690                                 iov_iter_advance(&tmp_from,
2691                                                  wdata->offset - iocb->ki_pos);
2692
2693                                 rc = cifs_write_from_iter(wdata->offset,
2694                                                 wdata->bytes, &tmp_from,
2695                                                 open_file, cifs_sb, &tmp_list);
2696
2697                                 list_splice(&tmp_list, &wdata_list);
2698
2699                                 kref_put(&wdata->refcount,
2700                                          cifs_uncached_writedata_release);
2701                                 goto restart_loop;
2702                         }
2703                 }
2704                 list_del_init(&wdata->list);
2705                 kref_put(&wdata->refcount, cifs_uncached_writedata_release);
2706         }
2707
2708         if (unlikely(!total_written))
2709                 return rc;
2710
2711         iocb->ki_pos += total_written;
2712         set_bit(CIFS_INO_INVALID_MAPPING, &CIFS_I(file_inode(file))->flags);
2713         cifs_stats_bytes_written(tcon, total_written);
2714         return total_written;
2715 }
2716
2717 static ssize_t
2718 cifs_writev(struct kiocb *iocb, struct iov_iter *from)
2719 {
2720         struct file *file = iocb->ki_filp;
2721         struct cifsFileInfo *cfile = (struct cifsFileInfo *)file->private_data;
2722         struct inode *inode = file->f_mapping->host;
2723         struct cifsInodeInfo *cinode = CIFS_I(inode);
2724         struct TCP_Server_Info *server = tlink_tcon(cfile->tlink)->ses->server;
2725         ssize_t rc;
2726
2727         /*
2728          * We need to hold the sem to be sure nobody modifies lock list
2729          * with a brlock that prevents writing.
2730          */
2731         down_read(&cinode->lock_sem);
2732         inode_lock(inode);
2733
2734         rc = generic_write_checks(iocb, from);
2735         if (rc <= 0)
2736                 goto out;
2737
2738         if (!cifs_find_lock_conflict(cfile, iocb->ki_pos, iov_iter_count(from),
2739                                      server->vals->exclusive_lock_type, NULL,
2740                                      CIFS_WRITE_OP))
2741                 rc = __generic_file_write_iter(iocb, from);
2742         else
2743                 rc = -EACCES;
2744 out:
2745         inode_unlock(inode);
2746
2747         if (rc > 0)
2748                 rc = generic_write_sync(iocb, rc);
2749         up_read(&cinode->lock_sem);
2750         return rc;
2751 }
2752
2753 ssize_t
2754 cifs_strict_writev(struct kiocb *iocb, struct iov_iter *from)
2755 {
2756         struct inode *inode = file_inode(iocb->ki_filp);
2757         struct cifsInodeInfo *cinode = CIFS_I(inode);
2758         struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
2759         struct cifsFileInfo *cfile = (struct cifsFileInfo *)
2760                                                 iocb->ki_filp->private_data;
2761         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
2762         ssize_t written;
2763
2764         written = cifs_get_writer(cinode);
2765         if (written)
2766                 return written;
2767
2768         if (CIFS_CACHE_WRITE(cinode)) {
2769                 if (cap_unix(tcon->ses) &&
2770                 (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability))
2771                   && ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0)) {
2772                         written = generic_file_write_iter(iocb, from);
2773                         goto out;
2774                 }
2775                 written = cifs_writev(iocb, from);
2776                 goto out;
2777         }
2778         /*
2779          * For non-oplocked files in strict cache mode we need to write the data
2780          * to the server exactly from the pos to pos+len-1 rather than flush all
2781          * affected pages because it may cause a error with mandatory locks on
2782          * these pages but not on the region from pos to ppos+len-1.
2783          */
2784         written = cifs_user_writev(iocb, from);
2785         if (written > 0 && CIFS_CACHE_READ(cinode)) {
2786                 /*
2787                  * Windows 7 server can delay breaking level2 oplock if a write
2788                  * request comes - break it on the client to prevent reading
2789                  * an old data.
2790                  */
2791                 cifs_zap_mapping(inode);
2792                 cifs_dbg(FYI, "Set no oplock for inode=%p after a write operation\n",
2793                          inode);
2794                 cinode->oplock = 0;
2795         }
2796 out:
2797         cifs_put_writer(cinode);
2798         return written;
2799 }
2800
2801 static struct cifs_readdata *
2802 cifs_readdata_alloc(unsigned int nr_pages, work_func_t complete)
2803 {
2804         struct cifs_readdata *rdata;
2805
2806         rdata = kzalloc(sizeof(*rdata) + (sizeof(struct page *) * nr_pages),
2807                         GFP_KERNEL);
2808         if (rdata != NULL) {
2809                 kref_init(&rdata->refcount);
2810                 INIT_LIST_HEAD(&rdata->list);
2811                 init_completion(&rdata->done);
2812                 INIT_WORK(&rdata->work, complete);
2813         }
2814
2815         return rdata;
2816 }
2817
2818 void
2819 cifs_readdata_release(struct kref *refcount)
2820 {
2821         struct cifs_readdata *rdata = container_of(refcount,
2822                                         struct cifs_readdata, refcount);
2823
2824         if (rdata->cfile)
2825                 cifsFileInfo_put(rdata->cfile);
2826
2827         kfree(rdata);
2828 }
2829
2830 static int
2831 cifs_read_allocate_pages(struct cifs_readdata *rdata, unsigned int nr_pages)
2832 {
2833         int rc = 0;
2834         struct page *page;
2835         unsigned int i;
2836
2837         for (i = 0; i < nr_pages; i++) {
2838                 page = alloc_page(GFP_KERNEL|__GFP_HIGHMEM);
2839                 if (!page) {
2840                         rc = -ENOMEM;
2841                         break;
2842                 }
2843                 rdata->pages[i] = page;
2844         }
2845
2846         if (rc) {
2847                 for (i = 0; i < nr_pages; i++) {
2848                         put_page(rdata->pages[i]);
2849                         rdata->pages[i] = NULL;
2850                 }
2851         }
2852         return rc;
2853 }
2854
2855 static void
2856 cifs_uncached_readdata_release(struct kref *refcount)
2857 {
2858         struct cifs_readdata *rdata = container_of(refcount,
2859                                         struct cifs_readdata, refcount);
2860         unsigned int i;
2861
2862         for (i = 0; i < rdata->nr_pages; i++) {
2863                 put_page(rdata->pages[i]);
2864                 rdata->pages[i] = NULL;
2865         }
2866         cifs_readdata_release(refcount);
2867 }
2868
2869 /**
2870  * cifs_readdata_to_iov - copy data from pages in response to an iovec
2871  * @rdata:      the readdata response with list of pages holding data
2872  * @iter:       destination for our data
2873  *
2874  * This function copies data from a list of pages in a readdata response into
2875  * an array of iovecs. It will first calculate where the data should go
2876  * based on the info in the readdata and then copy the data into that spot.
2877  */
2878 static int
2879 cifs_readdata_to_iov(struct cifs_readdata *rdata, struct iov_iter *iter)
2880 {
2881         size_t remaining = rdata->got_bytes;
2882         unsigned int i;
2883
2884         for (i = 0; i < rdata->nr_pages; i++) {
2885                 struct page *page = rdata->pages[i];
2886                 size_t copy = min_t(size_t, remaining, PAGE_SIZE);
2887                 size_t written = copy_page_to_iter(page, 0, copy, iter);
2888                 remaining -= written;
2889                 if (written < copy && iov_iter_count(iter) > 0)
2890                         break;
2891         }
2892         return remaining ? -EFAULT : 0;
2893 }
2894
2895 static void
2896 cifs_uncached_readv_complete(struct work_struct *work)
2897 {
2898         struct cifs_readdata *rdata = container_of(work,
2899                                                 struct cifs_readdata, work);
2900
2901         complete(&rdata->done);
2902         kref_put(&rdata->refcount, cifs_uncached_readdata_release);
2903 }
2904
2905 static int
2906 cifs_uncached_read_into_pages(struct TCP_Server_Info *server,
2907                         struct cifs_readdata *rdata, unsigned int len)
2908 {
2909         int result = 0;
2910         unsigned int i;
2911         unsigned int nr_pages = rdata->nr_pages;
2912
2913         rdata->got_bytes = 0;
2914         rdata->tailsz = PAGE_SIZE;
2915         for (i = 0; i < nr_pages; i++) {
2916                 struct page *page = rdata->pages[i];
2917                 size_t n;
2918
2919                 if (len <= 0) {
2920                         /* no need to hold page hostage */
2921                         rdata->pages[i] = NULL;
2922                         rdata->nr_pages--;
2923                         put_page(page);
2924                         continue;
2925                 }
2926                 n = len;
2927                 if (len >= PAGE_SIZE) {
2928                         /* enough data to fill the page */
2929                         n = PAGE_SIZE;
2930                         len -= n;
2931                 } else {
2932                         zero_user(page, len, PAGE_SIZE - len);
2933                         rdata->tailsz = len;
2934                         len = 0;
2935                 }
2936                 result = cifs_read_page_from_socket(server, page, n);
2937                 if (result < 0)
2938                         break;
2939
2940                 rdata->got_bytes += result;
2941         }
2942
2943         return rdata->got_bytes > 0 && result != -ECONNABORTED ?
2944                                                 rdata->got_bytes : result;
2945 }
2946
2947 static int
2948 cifs_send_async_read(loff_t offset, size_t len, struct cifsFileInfo *open_file,
2949                      struct cifs_sb_info *cifs_sb, struct list_head *rdata_list)
2950 {
2951         struct cifs_readdata *rdata;
2952         unsigned int npages, rsize, credits;
2953         size_t cur_len;
2954         int rc;
2955         pid_t pid;
2956         struct TCP_Server_Info *server;
2957
2958         server = tlink_tcon(open_file->tlink)->ses->server;
2959
2960         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
2961                 pid = open_file->pid;
2962         else
2963                 pid = current->tgid;
2964
2965         do {
2966                 rc = server->ops->wait_mtu_credits(server, cifs_sb->rsize,
2967                                                    &rsize, &credits);
2968                 if (rc)
2969                         break;
2970
2971                 cur_len = min_t(const size_t, len, rsize);
2972                 npages = DIV_ROUND_UP(cur_len, PAGE_SIZE);
2973
2974                 /* allocate a readdata struct */
2975                 rdata = cifs_readdata_alloc(npages,
2976                                             cifs_uncached_readv_complete);
2977                 if (!rdata) {
2978                         add_credits_and_wake_if(server, credits, 0);
2979                         rc = -ENOMEM;
2980                         break;
2981                 }
2982
2983                 rc = cifs_read_allocate_pages(rdata, npages);
2984                 if (rc)
2985                         goto error;
2986
2987                 rdata->cfile = cifsFileInfo_get(open_file);
2988                 rdata->nr_pages = npages;
2989                 rdata->offset = offset;
2990                 rdata->bytes = cur_len;
2991                 rdata->pid = pid;
2992                 rdata->pagesz = PAGE_SIZE;
2993                 rdata->read_into_pages = cifs_uncached_read_into_pages;
2994                 rdata->credits = credits;
2995
2996                 if (!rdata->cfile->invalidHandle ||
2997                     !cifs_reopen_file(rdata->cfile, true))
2998                         rc = server->ops->async_readv(rdata);
2999 error:
3000                 if (rc) {
3001                         add_credits_and_wake_if(server, rdata->credits, 0);
3002                         kref_put(&rdata->refcount,
3003                                  cifs_uncached_readdata_release);
3004                         if (rc == -EAGAIN)
3005                                 continue;
3006                         break;
3007                 }
3008
3009                 list_add_tail(&rdata->list, rdata_list);
3010                 offset += cur_len;
3011                 len -= cur_len;
3012         } while (len > 0);
3013
3014         return rc;
3015 }
3016
3017 ssize_t cifs_user_readv(struct kiocb *iocb, struct iov_iter *to)
3018 {
3019         struct file *file = iocb->ki_filp;
3020         ssize_t rc;
3021         size_t len;
3022         ssize_t total_read = 0;
3023         loff_t offset = iocb->ki_pos;
3024         struct cifs_sb_info *cifs_sb;
3025         struct cifs_tcon *tcon;
3026         struct cifsFileInfo *open_file;
3027         struct cifs_readdata *rdata, *tmp;
3028         struct list_head rdata_list;
3029
3030         len = iov_iter_count(to);
3031         if (!len)
3032                 return 0;
3033
3034         INIT_LIST_HEAD(&rdata_list);
3035         cifs_sb = CIFS_FILE_SB(file);
3036         open_file = file->private_data;
3037         tcon = tlink_tcon(open_file->tlink);
3038
3039         if (!tcon->ses->server->ops->async_readv)
3040                 return -ENOSYS;
3041
3042         if ((file->f_flags & O_ACCMODE) == O_WRONLY)
3043                 cifs_dbg(FYI, "attempting read on write only file instance\n");
3044
3045         rc = cifs_send_async_read(offset, len, open_file, cifs_sb, &rdata_list);
3046
3047         /* if at least one read request send succeeded, then reset rc */
3048         if (!list_empty(&rdata_list))
3049                 rc = 0;
3050
3051         len = iov_iter_count(to);
3052         /* the loop below should proceed in the order of increasing offsets */
3053 again:
3054         list_for_each_entry_safe(rdata, tmp, &rdata_list, list) {
3055                 if (!rc) {
3056                         /* FIXME: freezable sleep too? */
3057                         rc = wait_for_completion_killable(&rdata->done);
3058                         if (rc)
3059                                 rc = -EINTR;
3060                         else if (rdata->result == -EAGAIN) {
3061                                 /* resend call if it's a retryable error */
3062                                 struct list_head tmp_list;
3063                                 unsigned int got_bytes = rdata->got_bytes;
3064
3065                                 list_del_init(&rdata->list);
3066                                 INIT_LIST_HEAD(&tmp_list);
3067
3068                                 /*
3069                                  * Got a part of data and then reconnect has
3070                                  * happened -- fill the buffer and continue
3071                                  * reading.
3072                                  */
3073                                 if (got_bytes && got_bytes < rdata->bytes) {
3074                                         rc = cifs_readdata_to_iov(rdata, to);
3075                                         if (rc) {
3076                                                 kref_put(&rdata->refcount,
3077                                                 cifs_uncached_readdata_release);
3078                                                 continue;
3079                                         }
3080                                 }
3081
3082                                 rc = cifs_send_async_read(
3083                                                 rdata->offset + got_bytes,
3084                                                 rdata->bytes - got_bytes,
3085                                                 rdata->cfile, cifs_sb,
3086                                                 &tmp_list);
3087
3088                                 list_splice(&tmp_list, &rdata_list);
3089
3090                                 kref_put(&rdata->refcount,
3091                                          cifs_uncached_readdata_release);
3092                                 goto again;
3093                         } else if (rdata->result)
3094                                 rc = rdata->result;
3095                         else
3096                                 rc = cifs_readdata_to_iov(rdata, to);
3097
3098                         /* if there was a short read -- discard anything left */
3099                         if (rdata->got_bytes && rdata->got_bytes < rdata->bytes)
3100                                 rc = -ENODATA;
3101                 }
3102                 list_del_init(&rdata->list);
3103                 kref_put(&rdata->refcount, cifs_uncached_readdata_release);
3104         }
3105
3106         total_read = len - iov_iter_count(to);
3107
3108         cifs_stats_bytes_read(tcon, total_read);
3109
3110         /* mask nodata case */
3111         if (rc == -ENODATA)
3112                 rc = 0;
3113
3114         if (total_read) {
3115                 iocb->ki_pos += total_read;
3116                 return total_read;
3117         }
3118         return rc;
3119 }
3120
3121 ssize_t
3122 cifs_strict_readv(struct kiocb *iocb, struct iov_iter *to)
3123 {
3124         struct inode *inode = file_inode(iocb->ki_filp);
3125         struct cifsInodeInfo *cinode = CIFS_I(inode);
3126         struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
3127         struct cifsFileInfo *cfile = (struct cifsFileInfo *)
3128                                                 iocb->ki_filp->private_data;
3129         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
3130         int rc = -EACCES;
3131
3132         /*
3133          * In strict cache mode we need to read from the server all the time
3134          * if we don't have level II oplock because the server can delay mtime
3135          * change - so we can't make a decision about inode invalidating.
3136          * And we can also fail with pagereading if there are mandatory locks
3137          * on pages affected by this read but not on the region from pos to
3138          * pos+len-1.
3139          */
3140         if (!CIFS_CACHE_READ(cinode))
3141                 return cifs_user_readv(iocb, to);
3142
3143         if (cap_unix(tcon->ses) &&
3144             (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
3145             ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
3146                 return generic_file_read_iter(iocb, to);
3147
3148         /*
3149          * We need to hold the sem to be sure nobody modifies lock list
3150          * with a brlock that prevents reading.
3151          */
3152         down_read(&cinode->lock_sem);
3153         if (!cifs_find_lock_conflict(cfile, iocb->ki_pos, iov_iter_count(to),
3154                                      tcon->ses->server->vals->shared_lock_type,
3155                                      NULL, CIFS_READ_OP))
3156                 rc = generic_file_read_iter(iocb, to);
3157         up_read(&cinode->lock_sem);
3158         return rc;
3159 }
3160
3161 static ssize_t
3162 cifs_read(struct file *file, char *read_data, size_t read_size, loff_t *offset)
3163 {
3164         int rc = -EACCES;
3165         unsigned int bytes_read = 0;
3166         unsigned int total_read;
3167         unsigned int current_read_size;
3168         unsigned int rsize;
3169         struct cifs_sb_info *cifs_sb;
3170         struct cifs_tcon *tcon;
3171         struct TCP_Server_Info *server;
3172         unsigned int xid;
3173         char *cur_offset;
3174         struct cifsFileInfo *open_file;
3175         struct cifs_io_parms io_parms;
3176         int buf_type = CIFS_NO_BUFFER;
3177         __u32 pid;
3178
3179         xid = get_xid();
3180         cifs_sb = CIFS_FILE_SB(file);
3181
3182         /* FIXME: set up handlers for larger reads and/or convert to async */
3183         rsize = min_t(unsigned int, cifs_sb->rsize, CIFSMaxBufSize);
3184
3185         if (file->private_data == NULL) {
3186                 rc = -EBADF;
3187                 free_xid(xid);
3188                 return rc;
3189         }
3190         open_file = file->private_data;
3191         tcon = tlink_tcon(open_file->tlink);
3192         server = tcon->ses->server;
3193
3194         if (!server->ops->sync_read) {
3195                 free_xid(xid);
3196                 return -ENOSYS;
3197         }
3198
3199         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
3200                 pid = open_file->pid;
3201         else
3202                 pid = current->tgid;
3203
3204         if ((file->f_flags & O_ACCMODE) == O_WRONLY)
3205                 cifs_dbg(FYI, "attempting read on write only file instance\n");
3206
3207         for (total_read = 0, cur_offset = read_data; read_size > total_read;
3208              total_read += bytes_read, cur_offset += bytes_read) {
3209                 do {
3210                         current_read_size = min_t(uint, read_size - total_read,
3211                                                   rsize);
3212                         /*
3213                          * For windows me and 9x we do not want to request more
3214                          * than it negotiated since it will refuse the read
3215                          * then.
3216                          */
3217                         if ((tcon->ses) && !(tcon->ses->capabilities &
3218                                 tcon->ses->server->vals->cap_large_files)) {
3219                                 current_read_size = min_t(uint,
3220                                         current_read_size, CIFSMaxBufSize);
3221                         }
3222                         if (open_file->invalidHandle) {
3223                                 rc = cifs_reopen_file(open_file, true);
3224                                 if (rc != 0)
3225                                         break;
3226                         }
3227                         io_parms.pid = pid;
3228                         io_parms.tcon = tcon;
3229                         io_parms.offset = *offset;
3230                         io_parms.length = current_read_size;
3231                         rc = server->ops->sync_read(xid, &open_file->fid, &io_parms,
3232                                                     &bytes_read, &cur_offset,
3233                                                     &buf_type);
3234                 } while (rc == -EAGAIN);
3235
3236                 if (rc || (bytes_read == 0)) {
3237                         if (total_read) {
3238                                 break;
3239                         } else {
3240                                 free_xid(xid);
3241                                 return rc;
3242                         }
3243                 } else {
3244                         cifs_stats_bytes_read(tcon, total_read);
3245                         *offset += bytes_read;
3246                 }
3247         }
3248         free_xid(xid);
3249         return total_read;
3250 }
3251
3252 /*
3253  * If the page is mmap'ed into a process' page tables, then we need to make
3254  * sure that it doesn't change while being written back.
3255  */
3256 static int
3257 cifs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
3258 {
3259         struct page *page = vmf->page;
3260
3261         lock_page(page);
3262         return VM_FAULT_LOCKED;
3263 }
3264
3265 static const struct vm_operations_struct cifs_file_vm_ops = {
3266         .fault = filemap_fault,
3267         .map_pages = filemap_map_pages,
3268         .page_mkwrite = cifs_page_mkwrite,
3269 };
3270
3271 int cifs_file_strict_mmap(struct file *file, struct vm_area_struct *vma)
3272 {
3273         int rc, xid;
3274         struct inode *inode = file_inode(file);
3275
3276         xid = get_xid();
3277
3278         if (!CIFS_CACHE_READ(CIFS_I(inode))) {
3279                 rc = cifs_zap_mapping(inode);
3280                 if (rc)
3281                         return rc;
3282         }
3283
3284         rc = generic_file_mmap(file, vma);
3285         if (rc == 0)
3286                 vma->vm_ops = &cifs_file_vm_ops;
3287         free_xid(xid);
3288         return rc;
3289 }
3290
3291 int cifs_file_mmap(struct file *file, struct vm_area_struct *vma)
3292 {
3293         int rc, xid;
3294
3295         xid = get_xid();
3296         rc = cifs_revalidate_file(file);
3297         if (rc) {
3298                 cifs_dbg(FYI, "Validation prior to mmap failed, error=%d\n",
3299                          rc);
3300                 free_xid(xid);
3301                 return rc;
3302         }
3303         rc = generic_file_mmap(file, vma);
3304         if (rc == 0)
3305                 vma->vm_ops = &cifs_file_vm_ops;
3306         free_xid(xid);
3307         return rc;
3308 }
3309
3310 static void
3311 cifs_readv_complete(struct work_struct *work)
3312 {
3313         unsigned int i, got_bytes;
3314         struct cifs_readdata *rdata = container_of(work,
3315                                                 struct cifs_readdata, work);
3316
3317         got_bytes = rdata->got_bytes;
3318         for (i = 0; i < rdata->nr_pages; i++) {
3319                 struct page *page = rdata->pages[i];
3320
3321                 lru_cache_add_file(page);
3322
3323                 if (rdata->result == 0 ||
3324                     (rdata->result == -EAGAIN && got_bytes)) {
3325                         flush_dcache_page(page);
3326                         SetPageUptodate(page);
3327                 }
3328
3329                 unlock_page(page);
3330
3331                 if (rdata->result == 0 ||
3332                     (rdata->result == -EAGAIN && got_bytes))
3333                         cifs_readpage_to_fscache(rdata->mapping->host, page);
3334
3335                 got_bytes -= min_t(unsigned int, PAGE_SIZE, got_bytes);
3336
3337                 put_page(page);
3338                 rdata->pages[i] = NULL;
3339         }
3340         kref_put(&rdata->refcount, cifs_readdata_release);
3341 }
3342
3343 static int
3344 cifs_readpages_read_into_pages(struct TCP_Server_Info *server,
3345                         struct cifs_readdata *rdata, unsigned int len)
3346 {
3347         int result = 0;
3348         unsigned int i;
3349         u64 eof;
3350         pgoff_t eof_index;
3351         unsigned int nr_pages = rdata->nr_pages;
3352
3353         /* determine the eof that the server (probably) has */
3354         eof = CIFS_I(rdata->mapping->host)->server_eof;
3355         eof_index = eof ? (eof - 1) >> PAGE_SHIFT : 0;
3356         cifs_dbg(FYI, "eof=%llu eof_index=%lu\n", eof, eof_index);
3357
3358         rdata->got_bytes = 0;
3359         rdata->tailsz = PAGE_SIZE;
3360         for (i = 0; i < nr_pages; i++) {
3361                 struct page *page = rdata->pages[i];
3362                 size_t n = PAGE_SIZE;
3363
3364                 if (len >= PAGE_SIZE) {
3365                         len -= PAGE_SIZE;
3366                 } else if (len > 0) {
3367                         /* enough for partial page, fill and zero the rest */
3368                         zero_user(page, len, PAGE_SIZE - len);
3369                         n = rdata->tailsz = len;
3370                         len = 0;
3371                 } else if (page->index > eof_index) {
3372                         /*
3373                          * The VFS will not try to do readahead past the
3374                          * i_size, but it's possible that we have outstanding
3375                          * writes with gaps in the middle and the i_size hasn't
3376                          * caught up yet. Populate those with zeroed out pages
3377                          * to prevent the VFS from repeatedly attempting to
3378                          * fill them until the writes are flushed.
3379                          */
3380                         zero_user(page, 0, PAGE_SIZE);
3381                         lru_cache_add_file(page);
3382                         flush_dcache_page(page);
3383                         SetPageUptodate(page);
3384                         unlock_page(page);
3385                         put_page(page);
3386                         rdata->pages[i] = NULL;
3387                         rdata->nr_pages--;
3388                         continue;
3389                 } else {
3390                         /* no need to hold page hostage */
3391                         lru_cache_add_file(page);
3392                         unlock_page(page);
3393                         put_page(page);
3394                         rdata->pages[i] = NULL;
3395                         rdata->nr_pages--;
3396                         continue;
3397                 }
3398
3399                 result = cifs_read_page_from_socket(server, page, n);
3400                 if (result < 0)
3401                         break;
3402
3403                 rdata->got_bytes += result;
3404         }
3405
3406         return rdata->got_bytes > 0 && result != -ECONNABORTED ?
3407                                                 rdata->got_bytes : result;
3408 }
3409
3410 static int
3411 readpages_get_pages(struct address_space *mapping, struct list_head *page_list,
3412                     unsigned int rsize, struct list_head *tmplist,
3413                     unsigned int *nr_pages, loff_t *offset, unsigned int *bytes)
3414 {
3415         struct page *page, *tpage;
3416         unsigned int expected_index;
3417         int rc;
3418         gfp_t gfp = readahead_gfp_mask(mapping);
3419
3420         INIT_LIST_HEAD(tmplist);
3421
3422         page = list_entry(page_list->prev, struct page, lru);
3423
3424         /*
3425          * Lock the page and put it in the cache. Since no one else
3426          * should have access to this page, we're safe to simply set
3427          * PG_locked without checking it first.
3428          */
3429         __SetPageLocked(page);
3430         rc = add_to_page_cache_locked(page, mapping,
3431                                       page->index, gfp);
3432
3433         /* give up if we can't stick it in the cache */
3434         if (rc) {
3435                 __ClearPageLocked(page);
3436                 return rc;
3437         }
3438
3439         /* move first page to the tmplist */
3440         *offset = (loff_t)page->index << PAGE_SHIFT;
3441         *bytes = PAGE_SIZE;
3442         *nr_pages = 1;
3443         list_move_tail(&page->lru, tmplist);
3444
3445         /* now try and add more pages onto the request */
3446         expected_index = page->index + 1;
3447         list_for_each_entry_safe_reverse(page, tpage, page_list, lru) {
3448                 /* discontinuity ? */
3449                 if (page->index != expected_index)
3450                         break;
3451
3452                 /* would this page push the read over the rsize? */
3453                 if (*bytes + PAGE_SIZE > rsize)
3454                         break;
3455
3456                 __SetPageLocked(page);
3457                 if (add_to_page_cache_locked(page, mapping, page->index, gfp)) {
3458                         __ClearPageLocked(page);
3459                         break;
3460                 }
3461                 list_move_tail(&page->lru, tmplist);
3462                 (*bytes) += PAGE_SIZE;
3463                 expected_index++;
3464                 (*nr_pages)++;
3465         }
3466         return rc;
3467 }
3468
3469 static int cifs_readpages(struct file *file, struct address_space *mapping,
3470         struct list_head *page_list, unsigned num_pages)
3471 {
3472         int rc;
3473         struct list_head tmplist;
3474         struct cifsFileInfo *open_file = file->private_data;
3475         struct cifs_sb_info *cifs_sb = CIFS_FILE_SB(file);
3476         struct TCP_Server_Info *server;
3477         pid_t pid;
3478
3479         /*
3480          * Reads as many pages as possible from fscache. Returns -ENOBUFS
3481          * immediately if the cookie is negative
3482          *
3483          * After this point, every page in the list might have PG_fscache set,
3484          * so we will need to clean that up off of every page we don't use.
3485          */
3486         rc = cifs_readpages_from_fscache(mapping->host, mapping, page_list,
3487                                          &num_pages);
3488         if (rc == 0)
3489                 return rc;
3490
3491         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
3492                 pid = open_file->pid;
3493         else
3494                 pid = current->tgid;
3495
3496         rc = 0;
3497         server = tlink_tcon(open_file->tlink)->ses->server;
3498
3499         cifs_dbg(FYI, "%s: file=%p mapping=%p num_pages=%u\n",
3500                  __func__, file, mapping, num_pages);
3501
3502         /*
3503          * Start with the page at end of list and move it to private
3504          * list. Do the same with any following pages until we hit
3505          * the rsize limit, hit an index discontinuity, or run out of
3506          * pages. Issue the async read and then start the loop again
3507          * until the list is empty.
3508          *
3509          * Note that list order is important. The page_list is in
3510          * the order of declining indexes. When we put the pages in
3511          * the rdata->pages, then we want them in increasing order.
3512          */
3513         while (!list_empty(page_list)) {
3514                 unsigned int i, nr_pages, bytes, rsize;
3515                 loff_t offset;
3516                 struct page *page, *tpage;
3517                 struct cifs_readdata *rdata;
3518                 unsigned credits;
3519
3520                 rc = server->ops->wait_mtu_credits(server, cifs_sb->rsize,
3521                                                    &rsize, &credits);
3522                 if (rc)
3523                         break;
3524
3525                 /*
3526                  * Give up immediately if rsize is too small to read an entire
3527                  * page. The VFS will fall back to readpage. We should never
3528                  * reach this point however since we set ra_pages to 0 when the
3529                  * rsize is smaller than a cache page.
3530                  */
3531                 if (unlikely(rsize < PAGE_SIZE)) {
3532                         add_credits_and_wake_if(server, credits, 0);
3533                         return 0;
3534                 }
3535
3536                 rc = readpages_get_pages(mapping, page_list, rsize, &tmplist,
3537                                          &nr_pages, &offset, &bytes);
3538                 if (rc) {
3539                         add_credits_and_wake_if(server, credits, 0);
3540                         break;
3541                 }
3542
3543                 rdata = cifs_readdata_alloc(nr_pages, cifs_readv_complete);
3544                 if (!rdata) {
3545                         /* best to give up if we're out of mem */
3546                         list_for_each_entry_safe(page, tpage, &tmplist, lru) {
3547                                 list_del(&page->lru);
3548                                 lru_cache_add_file(page);
3549                                 unlock_page(page);
3550                                 put_page(page);
3551                         }
3552                         rc = -ENOMEM;
3553                         add_credits_and_wake_if(server, credits, 0);
3554                         break;
3555                 }
3556
3557                 rdata->cfile = cifsFileInfo_get(open_file);
3558                 rdata->mapping = mapping;
3559                 rdata->offset = offset;
3560                 rdata->bytes = bytes;
3561                 rdata->pid = pid;
3562                 rdata->pagesz = PAGE_SIZE;
3563                 rdata->read_into_pages = cifs_readpages_read_into_pages;
3564                 rdata->credits = credits;
3565
3566                 list_for_each_entry_safe(page, tpage, &tmplist, lru) {
3567                         list_del(&page->lru);
3568                         rdata->pages[rdata->nr_pages++] = page;
3569                 }
3570
3571                 if (!rdata->cfile->invalidHandle ||
3572                     !cifs_reopen_file(rdata->cfile, true))
3573                         rc = server->ops->async_readv(rdata);
3574                 if (rc) {
3575                         add_credits_and_wake_if(server, rdata->credits, 0);
3576                         for (i = 0; i < rdata->nr_pages; i++) {
3577                                 page = rdata->pages[i];
3578                                 lru_cache_add_file(page);
3579                                 unlock_page(page);
3580                                 put_page(page);
3581                         }
3582                         /* Fallback to the readpage in error/reconnect cases */
3583                         kref_put(&rdata->refcount, cifs_readdata_release);
3584                         break;
3585                 }
3586
3587                 kref_put(&rdata->refcount, cifs_readdata_release);
3588         }
3589
3590         /* Any pages that have been shown to fscache but didn't get added to
3591          * the pagecache must be uncached before they get returned to the
3592          * allocator.
3593          */
3594         cifs_fscache_readpages_cancel(mapping->host, page_list);
3595         return rc;
3596 }
3597
3598 /*
3599  * cifs_readpage_worker must be called with the page pinned
3600  */
3601 static int cifs_readpage_worker(struct file *file, struct page *page,
3602         loff_t *poffset)
3603 {
3604         char *read_data;
3605         int rc;
3606
3607         /* Is the page cached? */
3608         rc = cifs_readpage_from_fscache(file_inode(file), page);
3609         if (rc == 0)
3610                 goto read_complete;
3611
3612         read_data = kmap(page);
3613         /* for reads over a certain size could initiate async read ahead */
3614
3615         rc = cifs_read(file, read_data, PAGE_SIZE, poffset);
3616
3617         if (rc < 0)
3618                 goto io_error;
3619         else
3620                 cifs_dbg(FYI, "Bytes read %d\n", rc);
3621
3622         file_inode(file)->i_atime =
3623                 current_time(file_inode(file));
3624
3625         if (PAGE_SIZE > rc)
3626                 memset(read_data + rc, 0, PAGE_SIZE - rc);
3627
3628         flush_dcache_page(page);
3629         SetPageUptodate(page);
3630
3631         /* send this page to the cache */
3632         cifs_readpage_to_fscache(file_inode(file), page);
3633
3634         rc = 0;
3635
3636 io_error:
3637         kunmap(page);
3638         unlock_page(page);
3639
3640 read_complete:
3641         return rc;
3642 }
3643
3644 static int cifs_readpage(struct file *file, struct page *page)
3645 {
3646         loff_t offset = (loff_t)page->index << PAGE_SHIFT;
3647         int rc = -EACCES;
3648         unsigned int xid;
3649
3650         xid = get_xid();
3651
3652         if (file->private_data == NULL) {
3653                 rc = -EBADF;
3654                 free_xid(xid);
3655                 return rc;
3656         }
3657
3658         cifs_dbg(FYI, "readpage %p at offset %d 0x%x\n",
3659                  page, (int)offset, (int)offset);
3660
3661         rc = cifs_readpage_worker(file, page, &offset);
3662
3663         free_xid(xid);
3664         return rc;
3665 }
3666
3667 static int is_inode_writable(struct cifsInodeInfo *cifs_inode)
3668 {
3669         struct cifsFileInfo *open_file;
3670         struct cifs_tcon *tcon =
3671                 cifs_sb_master_tcon(CIFS_SB(cifs_inode->vfs_inode.i_sb));
3672
3673         spin_lock(&tcon->open_file_lock);
3674         list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
3675                 if (OPEN_FMODE(open_file->f_flags) & FMODE_WRITE) {
3676                         spin_unlock(&tcon->open_file_lock);
3677                         return 1;
3678                 }
3679         }
3680         spin_unlock(&tcon->open_file_lock);
3681         return 0;
3682 }
3683
3684 /* We do not want to update the file size from server for inodes
3685    open for write - to avoid races with writepage extending
3686    the file - in the future we could consider allowing
3687    refreshing the inode only on increases in the file size
3688    but this is tricky to do without racing with writebehind
3689    page caching in the current Linux kernel design */
3690 bool is_size_safe_to_change(struct cifsInodeInfo *cifsInode, __u64 end_of_file)
3691 {
3692         if (!cifsInode)
3693                 return true;
3694
3695         if (is_inode_writable(cifsInode)) {
3696                 /* This inode is open for write at least once */
3697                 struct cifs_sb_info *cifs_sb;
3698
3699                 cifs_sb = CIFS_SB(cifsInode->vfs_inode.i_sb);
3700                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DIRECT_IO) {
3701                         /* since no page cache to corrupt on directio
3702                         we can change size safely */
3703                         return true;
3704                 }
3705
3706                 if (i_size_read(&cifsInode->vfs_inode) < end_of_file)
3707                         return true;
3708
3709                 return false;
3710         } else
3711                 return true;
3712 }
3713
3714 static int cifs_write_begin(struct file *file, struct address_space *mapping,
3715                         loff_t pos, unsigned len, unsigned flags,
3716                         struct page **pagep, void **fsdata)
3717 {
3718         int oncethru = 0;
3719         pgoff_t index = pos >> PAGE_SHIFT;
3720         loff_t offset = pos & (PAGE_SIZE - 1);
3721         loff_t page_start = pos & PAGE_MASK;
3722         loff_t i_size;
3723         struct page *page;
3724         int rc = 0;
3725
3726         cifs_dbg(FYI, "write_begin from %lld len %d\n", (long long)pos, len);
3727
3728 start:
3729         page = grab_cache_page_write_begin(mapping, index, flags);
3730         if (!page) {
3731                 rc = -ENOMEM;
3732                 goto out;
3733         }
3734
3735         if (PageUptodate(page))
3736                 goto out;
3737
3738         /*
3739          * If we write a full page it will be up to date, no need to read from
3740          * the server. If the write is short, we'll end up doing a sync write
3741          * instead.
3742          */
3743         if (len == PAGE_SIZE)
3744                 goto out;
3745
3746         /*
3747          * optimize away the read when we have an oplock, and we're not
3748          * expecting to use any of the data we'd be reading in. That
3749          * is, when the page lies beyond the EOF, or straddles the EOF
3750          * and the write will cover all of the existing data.
3751          */
3752         if (CIFS_CACHE_READ(CIFS_I(mapping->host))) {
3753                 i_size = i_size_read(mapping->host);
3754                 if (page_start >= i_size ||
3755                     (offset == 0 && (pos + len) >= i_size)) {
3756                         zero_user_segments(page, 0, offset,
3757                                            offset + len,
3758                                            PAGE_SIZE);
3759                         /*
3760                          * PageChecked means that the parts of the page
3761                          * to which we're not writing are considered up
3762                          * to date. Once the data is copied to the
3763                          * page, it can be set uptodate.
3764                          */
3765                         SetPageChecked(page);
3766                         goto out;
3767                 }
3768         }
3769
3770         if ((file->f_flags & O_ACCMODE) != O_WRONLY && !oncethru) {
3771                 /*
3772                  * might as well read a page, it is fast enough. If we get
3773                  * an error, we don't need to return it. cifs_write_end will
3774                  * do a sync write instead since PG_uptodate isn't set.
3775                  */
3776                 cifs_readpage_worker(file, page, &page_start);
3777                 put_page(page);
3778                 oncethru = 1;
3779                 goto start;
3780         } else {
3781                 /* we could try using another file handle if there is one -
3782                    but how would we lock it to prevent close of that handle
3783                    racing with this read? In any case
3784                    this will be written out by write_end so is fine */
3785         }
3786 out:
3787         *pagep = page;
3788         return rc;
3789 }
3790
3791 static int cifs_release_page(struct page *page, gfp_t gfp)
3792 {
3793         if (PagePrivate(page))
3794                 return 0;
3795
3796         return cifs_fscache_release_page(page, gfp);
3797 }
3798
3799 static void cifs_invalidate_page(struct page *page, unsigned int offset,
3800                                  unsigned int length)
3801 {
3802         struct cifsInodeInfo *cifsi = CIFS_I(page->mapping->host);
3803
3804         if (offset == 0 && length == PAGE_SIZE)
3805                 cifs_fscache_invalidate_page(page, &cifsi->vfs_inode);
3806 }
3807
3808 static int cifs_launder_page(struct page *page)
3809 {
3810         int rc = 0;
3811         loff_t range_start = page_offset(page);
3812         loff_t range_end = range_start + (loff_t)(PAGE_SIZE - 1);
3813         struct writeback_control wbc = {
3814                 .sync_mode = WB_SYNC_ALL,
3815                 .nr_to_write = 0,
3816                 .range_start = range_start,
3817                 .range_end = range_end,
3818         };
3819
3820         cifs_dbg(FYI, "Launder page: %p\n", page);
3821
3822         if (clear_page_dirty_for_io(page))
3823                 rc = cifs_writepage_locked(page, &wbc);
3824
3825         cifs_fscache_invalidate_page(page, page->mapping->host);
3826         return rc;
3827 }
3828
3829 void cifs_oplock_break(struct work_struct *work)
3830 {
3831         struct cifsFileInfo *cfile = container_of(work, struct cifsFileInfo,
3832                                                   oplock_break);
3833         struct inode *inode = d_inode(cfile->dentry);
3834         struct cifsInodeInfo *cinode = CIFS_I(inode);
3835         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
3836         struct TCP_Server_Info *server = tcon->ses->server;
3837         int rc = 0;
3838
3839         wait_on_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS,
3840                         TASK_UNINTERRUPTIBLE);
3841
3842         server->ops->downgrade_oplock(server, cinode,
3843                 test_bit(CIFS_INODE_DOWNGRADE_OPLOCK_TO_L2, &cinode->flags));
3844
3845         if (!CIFS_CACHE_WRITE(cinode) && CIFS_CACHE_READ(cinode) &&
3846                                                 cifs_has_mand_locks(cinode)) {
3847                 cifs_dbg(FYI, "Reset oplock to None for inode=%p due to mand locks\n",
3848                          inode);
3849                 cinode->oplock = 0;
3850         }
3851
3852         if (inode && S_ISREG(inode->i_mode)) {
3853                 if (CIFS_CACHE_READ(cinode))
3854                         break_lease(inode, O_RDONLY);
3855                 else
3856                         break_lease(inode, O_WRONLY);
3857                 rc = filemap_fdatawrite(inode->i_mapping);
3858                 if (!CIFS_CACHE_READ(cinode)) {
3859                         rc = filemap_fdatawait(inode->i_mapping);
3860                         mapping_set_error(inode->i_mapping, rc);
3861                         cifs_zap_mapping(inode);
3862                 }
3863                 cifs_dbg(FYI, "Oplock flush inode %p rc %d\n", inode, rc);
3864         }
3865
3866         rc = cifs_push_locks(cfile);
3867         if (rc)
3868                 cifs_dbg(VFS, "Push locks rc = %d\n", rc);
3869
3870         /*
3871          * releasing stale oplock after recent reconnect of smb session using
3872          * a now incorrect file handle is not a data integrity issue but do
3873          * not bother sending an oplock release if session to server still is
3874          * disconnected since oplock already released by the server
3875          */
3876         if (!cfile->oplock_break_cancelled) {
3877                 rc = tcon->ses->server->ops->oplock_response(tcon, &cfile->fid,
3878                                                              cinode);
3879                 cifs_dbg(FYI, "Oplock release rc = %d\n", rc);
3880         }
3881         cifs_done_oplock_break(cinode);
3882 }
3883
3884 /*
3885  * The presence of cifs_direct_io() in the address space ops vector
3886  * allowes open() O_DIRECT flags which would have failed otherwise.
3887  *
3888  * In the non-cached mode (mount with cache=none), we shunt off direct read and write requests
3889  * so this method should never be called.
3890  *
3891  * Direct IO is not yet supported in the cached mode.
3892  */
3893 static ssize_t
3894 cifs_direct_io(struct kiocb *iocb, struct iov_iter *iter)
3895 {
3896         /*
3897          * FIXME
3898          * Eventually need to support direct IO for non forcedirectio mounts
3899          */
3900         return -EINVAL;
3901 }
3902
3903
3904 const struct address_space_operations cifs_addr_ops = {
3905         .readpage = cifs_readpage,
3906         .readpages = cifs_readpages,
3907         .writepage = cifs_writepage,
3908         .writepages = cifs_writepages,
3909         .write_begin = cifs_write_begin,
3910         .write_end = cifs_write_end,
3911         .set_page_dirty = __set_page_dirty_nobuffers,
3912         .releasepage = cifs_release_page,
3913         .direct_IO = cifs_direct_io,
3914         .invalidatepage = cifs_invalidate_page,
3915         .launder_page = cifs_launder_page,
3916 };
3917
3918 /*
3919  * cifs_readpages requires the server to support a buffer large enough to
3920  * contain the header plus one complete page of data.  Otherwise, we need
3921  * to leave cifs_readpages out of the address space operations.
3922  */
3923 const struct address_space_operations cifs_addr_ops_smallbuf = {
3924         .readpage = cifs_readpage,
3925         .writepage = cifs_writepage,
3926         .writepages = cifs_writepages,
3927         .write_begin = cifs_write_begin,
3928         .write_end = cifs_write_end,
3929         .set_page_dirty = __set_page_dirty_nobuffers,
3930         .releasepage = cifs_release_page,
3931         .invalidatepage = cifs_invalidate_page,
3932         .launder_page = cifs_launder_page,
3933 };