fs/cifs/file.c

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