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 #include "smbdirect.h"
  46
  47 static inline int cifs_convert_flags(unsigned int flags)
  48 {
  49         if ((flags & O_ACCMODE) == O_RDONLY)
  50                 return GENERIC_READ;
  51         else if ((flags & O_ACCMODE) == O_WRONLY)
  52                 return GENERIC_WRITE;
  53         else if ((flags & O_ACCMODE) == O_RDWR) {
  54                 /* GENERIC_ALL is too much permission to request
  55                    can cause unnecessary access denied on create */
  56                 /* return GENERIC_ALL; */
  57                 return (GENERIC_READ | GENERIC_WRITE);
  58         }
  59
  60         return (READ_CONTROL | FILE_WRITE_ATTRIBUTES | FILE_READ_ATTRIBUTES |
  61                 FILE_WRITE_EA | FILE_APPEND_DATA | FILE_WRITE_DATA |
  62                 FILE_READ_DATA);
  63 }
  64
  65 static u32 cifs_posix_convert_flags(unsigned int flags)
  66 {
  67         u32 posix_flags = 0;
  68
  69         if ((flags & O_ACCMODE) == O_RDONLY)
  70                 posix_flags = SMB_O_RDONLY;
  71         else if ((flags & O_ACCMODE) == O_WRONLY)
  72                 posix_flags = SMB_O_WRONLY;
  73         else if ((flags & O_ACCMODE) == O_RDWR)
  74                 posix_flags = SMB_O_RDWR;
  75
  76         if (flags & O_CREAT) {
  77                 posix_flags |= SMB_O_CREAT;
  78                 if (flags & O_EXCL)
  79                         posix_flags |= SMB_O_EXCL;
  80         } else if (flags & O_EXCL)
  81                 cifs_dbg(FYI, "Application %s pid %d has incorrectly set O_EXCL flag but not O_CREAT on file open. Ignoring O_EXCL\n",
  82                          current->comm, current->tgid);
  83
  84         if (flags & O_TRUNC)
  85                 posix_flags |= SMB_O_TRUNC;
  86         /* be safe and imply O_SYNC for O_DSYNC */
  87         if (flags & O_DSYNC)
  88                 posix_flags |= SMB_O_SYNC;
  89         if (flags & O_DIRECTORY)
  90                 posix_flags |= SMB_O_DIRECTORY;
  91         if (flags & O_NOFOLLOW)
  92                 posix_flags |= SMB_O_NOFOLLOW;
  93         if (flags & O_DIRECT)
  94                 posix_flags |= SMB_O_DIRECT;
  95
  96         return posix_flags;
  97 }
  98
  99 static inline int cifs_get_disposition(unsigned int flags)
 100 {
 101         if ((flags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
 102                 return FILE_CREATE;
 103         else if ((flags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
 104                 return FILE_OVERWRITE_IF;
 105         else if ((flags & O_CREAT) == O_CREAT)
 106                 return FILE_OPEN_IF;
 107         else if ((flags & O_TRUNC) == O_TRUNC)
 108                 return FILE_OVERWRITE;
 109         else
 110                 return FILE_OPEN;
 111 }
 112
 113 int cifs_posix_open(char *full_path, struct inode **pinode,
 114                         struct super_block *sb, int mode, unsigned int f_flags,
 115                         __u32 *poplock, __u16 *pnetfid, unsigned int xid)
 116 {
 117         int rc;
 118         FILE_UNIX_BASIC_INFO *presp_data;
 119         __u32 posix_flags = 0;
 120         struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
 121         struct cifs_fattr fattr;
 122         struct tcon_link *tlink;
 123         struct cifs_tcon *tcon;
 124
 125         cifs_dbg(FYI, "posix open %s\n", full_path);
 126
 127         presp_data = kzalloc(sizeof(FILE_UNIX_BASIC_INFO), GFP_KERNEL);
 128         if (presp_data == NULL)
 129                 return -ENOMEM;
 130
 131         tlink = cifs_sb_tlink(cifs_sb);
 132         if (IS_ERR(tlink)) {
 133                 rc = PTR_ERR(tlink);
 134                 goto posix_open_ret;
 135         }
 136
 137         tcon = tlink_tcon(tlink);
 138         mode &= ~current_umask();
 139
 140         posix_flags = cifs_posix_convert_flags(f_flags);
 141         rc = CIFSPOSIXCreate(xid, tcon, posix_flags, mode, pnetfid, presp_data,
 142                              poplock, full_path, cifs_sb->local_nls,
 143                              cifs_remap(cifs_sb));
 144         cifs_put_tlink(tlink);
 145
 146         if (rc)
 147                 goto posix_open_ret;
 148
 149         if (presp_data->Type == cpu_to_le32(-1))
 150                 goto posix_open_ret; /* open ok, caller does qpathinfo */
 151
 152         if (!pinode)
 153                 goto posix_open_ret; /* caller does not need info */
 154
 155         cifs_unix_basic_to_fattr(&fattr, presp_data, cifs_sb);
 156
 157         /* get new inode and set it up */
 158         if (*pinode == NULL) {
 159                 cifs_fill_uniqueid(sb, &fattr);
 160                 *pinode = cifs_iget(sb, &fattr);
 161                 if (!*pinode) {
 162                         rc = -ENOMEM;
 163                         goto posix_open_ret;
 164                 }
 165         } else {
 166                 cifs_fattr_to_inode(*pinode, &fattr);
 167         }
 168
 169 posix_open_ret:
 170         kfree(presp_data);
 171         return rc;
 172 }
 173
 174 static int
 175 cifs_nt_open(char *full_path, struct inode *inode, struct cifs_sb_info *cifs_sb,
 176              struct cifs_tcon *tcon, unsigned int f_flags, __u32 *oplock,
 177              struct cifs_fid *fid, unsigned int xid)
 178 {
 179         int rc;
 180         int desired_access;
 181         int disposition;
 182         int create_options = CREATE_NOT_DIR;
 183         FILE_ALL_INFO *buf;
 184         struct TCP_Server_Info *server = tcon->ses->server;
 185         struct cifs_open_parms oparms;
 186
 187         if (!server->ops->open)
 188                 return -ENOSYS;
 189
 190         desired_access = cifs_convert_flags(f_flags);
 191
 192 /*********************************************************************
 193  *  open flag mapping table:
 194  *
 195  *      POSIX Flag            CIFS Disposition
 196  *      ----------            ----------------
 197  *      O_CREAT               FILE_OPEN_IF
 198  *      O_CREAT | O_EXCL      FILE_CREATE
 199  *      O_CREAT | O_TRUNC     FILE_OVERWRITE_IF
 200  *      O_TRUNC               FILE_OVERWRITE
 201  *      none of the above     FILE_OPEN
 202  *
 203  *      Note that there is not a direct match between disposition
 204  *      FILE_SUPERSEDE (ie create whether or not file exists although
 205  *      O_CREAT | O_TRUNC is similar but truncates the existing
 206  *      file rather than creating a new file as FILE_SUPERSEDE does
 207  *      (which uses the attributes / metadata passed in on open call)
 208  *?
 209  *?  O_SYNC is a reasonable match to CIFS writethrough flag
 210  *?  and the read write flags match reasonably.  O_LARGEFILE
 211  *?  is irrelevant because largefile support is always used
 212  *?  by this client. Flags O_APPEND, O_DIRECT, O_DIRECTORY,
 213  *       O_FASYNC, O_NOFOLLOW, O_NONBLOCK need further investigation
 214  *********************************************************************/
 215
 216         disposition = cifs_get_disposition(f_flags);
 217
 218         /* BB pass O_SYNC flag through on file attributes .. BB */
 219
 220         buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
 221         if (!buf)
 222                 return -ENOMEM;
 223
 224         if (backup_cred(cifs_sb))
 225                 create_options |= CREATE_OPEN_BACKUP_INTENT;
 226
 227         /* O_SYNC also has bit for O_DSYNC so following check picks up either */
 228         if (f_flags & O_SYNC)
 229                 create_options |= CREATE_WRITE_THROUGH;
 230
 231         if (f_flags & O_DIRECT)
 232                 create_options |= CREATE_NO_BUFFER;
 233
 234         oparms.tcon = tcon;
 235         oparms.cifs_sb = cifs_sb;
 236         oparms.desired_access = desired_access;
 237         oparms.create_options = create_options;
 238         oparms.disposition = disposition;
 239         oparms.path = full_path;
 240         oparms.fid = fid;
 241         oparms.reconnect = false;
 242
 243         rc = server->ops->open(xid, &oparms, oplock, buf);
 244
 245         if (rc)
 246                 goto out;
 247
 248         if (tcon->unix_ext)
 249                 rc = cifs_get_inode_info_unix(&inode, full_path, inode->i_sb,
 250                                               xid);
 251         else
 252                 rc = cifs_get_inode_info(&inode, full_path, buf, inode->i_sb,
 253                                          xid, fid);
 254
 255 out:
 256         kfree(buf);
 257         return rc;
 258 }
 259
 260 static bool
 261 cifs_has_mand_locks(struct cifsInodeInfo *cinode)
 262 {
 263         struct cifs_fid_locks *cur;
 264         bool has_locks = false;
 265
 266         down_read(&cinode->lock_sem);
 267         list_for_each_entry(cur, &cinode->llist, llist) {
 268                 if (!list_empty(&cur->locks)) {
 269                         has_locks = true;
 270                         break;
 271                 }
 272         }
 273         up_read(&cinode->lock_sem);
 274         return has_locks;
 275 }
 276
 277 struct cifsFileInfo *
 278 cifs_new_fileinfo(struct cifs_fid *fid, struct file *file,
 279                   struct tcon_link *tlink, __u32 oplock)
 280 {
 281         struct dentry *dentry = file_dentry(file);
 282         struct inode *inode = d_inode(dentry);
 283         struct cifsInodeInfo *cinode = CIFS_I(inode);
 284         struct cifsFileInfo *cfile;
 285         struct cifs_fid_locks *fdlocks;
 286         struct cifs_tcon *tcon = tlink_tcon(tlink);
 287         struct TCP_Server_Info *server = tcon->ses->server;
 288
 289         cfile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
 290         if (cfile == NULL)
 291                 return cfile;
 292
 293         fdlocks = kzalloc(sizeof(struct cifs_fid_locks), GFP_KERNEL);
 294         if (!fdlocks) {
 295                 kfree(cfile);
 296                 return NULL;
 297         }
 298
 299         INIT_LIST_HEAD(&fdlocks->locks);
 300         fdlocks->cfile = cfile;
 301         cfile->llist = fdlocks;
 302         down_write(&cinode->lock_sem);
 303         list_add(&fdlocks->llist, &cinode->llist);
 304         up_write(&cinode->lock_sem);
 305
 306         cfile->count = 1;
 307         cfile->pid = current->tgid;
 308         cfile->uid = current_fsuid();
 309         cfile->dentry = dget(dentry);
 310         cfile->f_flags = file->f_flags;
 311         cfile->invalidHandle = false;
 312         cfile->tlink = cifs_get_tlink(tlink);
 313         INIT_WORK(&cfile->oplock_break, cifs_oplock_break);
 314         mutex_init(&cfile->fh_mutex);
 315         spin_lock_init(&cfile->file_info_lock);
 316
 317         cifs_sb_active(inode->i_sb);
 318
 319         /*
 320          * If the server returned a read oplock and we have mandatory brlocks,
 321          * set oplock level to None.
 322          */
 323         if (server->ops->is_read_op(oplock) && cifs_has_mand_locks(cinode)) {
 324                 cifs_dbg(FYI, "Reset oplock val from read to None due to mand locks\n");
 325                 oplock = 0;
 326         }
 327
 328         spin_lock(&tcon->open_file_lock);
 329         if (fid->pending_open->oplock != CIFS_OPLOCK_NO_CHANGE && oplock)
 330                 oplock = fid->pending_open->oplock;
 331         list_del(&fid->pending_open->olist);
 332
 333         fid->purge_cache = false;
 334         server->ops->set_fid(cfile, fid, oplock);
 335
 336         list_add(&cfile->tlist, &tcon->openFileList);
 337
 338         /* if readable file instance put first in list*/
 339         if (file->f_mode & FMODE_READ)
 340                 list_add(&cfile->flist, &cinode->openFileList);
 341         else
 342                 list_add_tail(&cfile->flist, &cinode->openFileList);
 343         spin_unlock(&tcon->open_file_lock);
 344
 345         if (fid->purge_cache)
 346                 cifs_zap_mapping(inode);
 347
 348         file->private_data = cfile;
 349         return cfile;
 350 }
 351
 352 struct cifsFileInfo *
 353 cifsFileInfo_get(struct cifsFileInfo *cifs_file)
 354 {
 355         spin_lock(&cifs_file->file_info_lock);
 356         cifsFileInfo_get_locked(cifs_file);
 357         spin_unlock(&cifs_file->file_info_lock);
 358         return cifs_file;
 359 }
 360
 361 /*
 362  * Release a reference on the file private data. This may involve closing
 363  * the filehandle out on the server. Must be called without holding
 364  * tcon->open_file_lock and cifs_file->file_info_lock.
 365  */
 366 void cifsFileInfo_put(struct cifsFileInfo *cifs_file)
 367 {
 368         struct inode *inode = d_inode(cifs_file->dentry);
 369         struct cifs_tcon *tcon = tlink_tcon(cifs_file->tlink);
 370         struct TCP_Server_Info *server = tcon->ses->server;
 371         struct cifsInodeInfo *cifsi = CIFS_I(inode);
 372         struct super_block *sb = inode->i_sb;
 373         struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
 374         struct cifsLockInfo *li, *tmp;
 375         struct cifs_fid fid;
 376         struct cifs_pending_open open;
 377         bool oplock_break_cancelled;
 378
 379         spin_lock(&tcon->open_file_lock);
 380
 381         spin_lock(&cifs_file->file_info_lock);
 382         if (--cifs_file->count > 0) {
 383                 spin_unlock(&cifs_file->file_info_lock);
 384                 spin_unlock(&tcon->open_file_lock);
 385                 return;
 386         }
 387         spin_unlock(&cifs_file->file_info_lock);
 388
 389         if (server->ops->get_lease_key)
 390                 server->ops->get_lease_key(inode, &fid);
 391
 392         /* store open in pending opens to make sure we don't miss lease break */
 393         cifs_add_pending_open_locked(&fid, cifs_file->tlink, &open);
 394
 395         /* remove it from the lists */
 396         list_del(&cifs_file->flist);
 397         list_del(&cifs_file->tlist);
 398
 399         if (list_empty(&cifsi->openFileList)) {
 400                 cifs_dbg(FYI, "closing last open instance for inode %p\n",
 401                          d_inode(cifs_file->dentry));
 402                 /*
 403                  * In strict cache mode we need invalidate mapping on the last
 404                  * close  because it may cause a error when we open this file
 405                  * again and get at least level II oplock.
 406                  */
 407                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_STRICT_IO)
 408                         set_bit(CIFS_INO_INVALID_MAPPING, &cifsi->flags);
 409                 cifs_set_oplock_level(cifsi, 0);
 410         }
 411
 412         spin_unlock(&tcon->open_file_lock);
 413
 414         oplock_break_cancelled = cancel_work_sync(&cifs_file->oplock_break);
 415
 416         if (!tcon->need_reconnect && !cifs_file->invalidHandle) {
 417                 struct TCP_Server_Info *server = tcon->ses->server;
 418                 unsigned int xid;
 419
 420                 xid = get_xid();
 421                 if (server->ops->close)
 422                         server->ops->close(xid, tcon, &cifs_file->fid);
 423                 _free_xid(xid);
 424         }
 425
 426         if (oplock_break_cancelled)
 427                 cifs_done_oplock_break(cifsi);
 428
 429         cifs_del_pending_open(&open);
 430
 431         /*
 432          * Delete any outstanding lock records. We'll lose them when the file
 433          * is closed anyway.
 434          */
 435         down_write(&cifsi->lock_sem);
 436         list_for_each_entry_safe(li, tmp, &cifs_file->llist->locks, llist) {
 437                 list_del(&li->llist);
 438                 cifs_del_lock_waiters(li);
 439                 kfree(li);
 440         }
 441         list_del(&cifs_file->llist->llist);
 442         kfree(cifs_file->llist);
 443         up_write(&cifsi->lock_sem);
 444
 445         cifs_put_tlink(cifs_file->tlink);
 446         dput(cifs_file->dentry);
 447         cifs_sb_deactive(sb);
 448         kfree(cifs_file);
 449 }
 450
 451 int cifs_open(struct inode *inode, struct file *file)
 452
 453 {
 454         int rc = -EACCES;
 455         unsigned int xid;
 456         __u32 oplock;
 457         struct cifs_sb_info *cifs_sb;
 458         struct TCP_Server_Info *server;
 459         struct cifs_tcon *tcon;
 460         struct tcon_link *tlink;
 461         struct cifsFileInfo *cfile = NULL;
 462         char *full_path = NULL;
 463         bool posix_open_ok = false;
 464         struct cifs_fid fid;
 465         struct cifs_pending_open open;
 466
 467         xid = get_xid();
 468
 469         cifs_sb = CIFS_SB(inode->i_sb);
 470         tlink = cifs_sb_tlink(cifs_sb);
 471         if (IS_ERR(tlink)) {
 472                 free_xid(xid);
 473                 return PTR_ERR(tlink);
 474         }
 475         tcon = tlink_tcon(tlink);
 476         server = tcon->ses->server;
 477
 478         full_path = build_path_from_dentry(file_dentry(file));
 479         if (full_path == NULL) {
 480                 rc = -ENOMEM;
 481                 goto out;
 482         }
 483
 484         cifs_dbg(FYI, "inode = 0x%p file flags are 0x%x for %s\n",
 485                  inode, file->f_flags, full_path);
 486
 487         if (file->f_flags & O_DIRECT &&
 488             cifs_sb->mnt_cifs_flags & CIFS_MOUNT_STRICT_IO) {
 489                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_BRL)
 490                         file->f_op = &cifs_file_direct_nobrl_ops;
 491                 else
 492                         file->f_op = &cifs_file_direct_ops;
 493         }
 494
 495         if (server->oplocks)
 496                 oplock = REQ_OPLOCK;
 497         else
 498                 oplock = 0;
 499
 500         if (!tcon->broken_posix_open && tcon->unix_ext &&
 501             cap_unix(tcon->ses) && (CIFS_UNIX_POSIX_PATH_OPS_CAP &
 502                                 le64_to_cpu(tcon->fsUnixInfo.Capability))) {
 503                 /* can not refresh inode info since size could be stale */
 504                 rc = cifs_posix_open(full_path, &inode, inode->i_sb,
 505                                 cifs_sb->mnt_file_mode /* ignored */,
 506                                 file->f_flags, &oplock, &fid.netfid, xid);
 507                 if (rc == 0) {
 508                         cifs_dbg(FYI, "posix open succeeded\n");
 509                         posix_open_ok = true;
 510                 } else if ((rc == -EINVAL) || (rc == -EOPNOTSUPP)) {
 511                         if (tcon->ses->serverNOS)
 512                                 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",
 513                                          tcon->ses->serverName,
 514                                          tcon->ses->serverNOS);
 515                         tcon->broken_posix_open = true;
 516                 } else if ((rc != -EIO) && (rc != -EREMOTE) &&
 517                          (rc != -EOPNOTSUPP)) /* path not found or net err */
 518                         goto out;
 519                 /*
 520                  * Else fallthrough to retry open the old way on network i/o
 521                  * or DFS errors.
 522                  */
 523         }
 524
 525         if (server->ops->get_lease_key)
 526                 server->ops->get_lease_key(inode, &fid);
 527
 528         cifs_add_pending_open(&fid, tlink, &open);
 529
 530         if (!posix_open_ok) {
 531                 if (server->ops->get_lease_key)
 532                         server->ops->get_lease_key(inode, &fid);
 533
 534                 rc = cifs_nt_open(full_path, inode, cifs_sb, tcon,
 535                                   file->f_flags, &oplock, &fid, xid);
 536                 if (rc) {
 537                         cifs_del_pending_open(&open);
 538                         goto out;
 539                 }
 540         }
 541
 542         cfile = cifs_new_fileinfo(&fid, file, tlink, oplock);
 543         if (cfile == NULL) {
 544                 if (server->ops->close)
 545                         server->ops->close(xid, tcon, &fid);
 546                 cifs_del_pending_open(&open);
 547                 rc = -ENOMEM;
 548                 goto out;
 549         }
 550
 551         cifs_fscache_set_inode_cookie(inode, file);
 552
 553         if ((oplock & CIFS_CREATE_ACTION) && !posix_open_ok && tcon->unix_ext) {
 554                 /*
 555                  * Time to set mode which we can not set earlier due to
 556                  * problems creating new read-only files.
 557                  */
 558                 struct cifs_unix_set_info_args args = {
 559                         .mode   = inode->i_mode,
 560                         .uid    = INVALID_UID, /* no change */
 561                         .gid    = INVALID_GID, /* no change */
 562                         .ctime  = NO_CHANGE_64,
 563                         .atime  = NO_CHANGE_64,
 564                         .mtime  = NO_CHANGE_64,
 565                         .device = 0,
 566                 };
 567                 CIFSSMBUnixSetFileInfo(xid, tcon, &args, fid.netfid,
 568                                        cfile->pid);
 569         }
 570
 571 out:
 572         kfree(full_path);
 573         free_xid(xid);
 574         cifs_put_tlink(tlink);
 575         return rc;
 576 }
 577
 578 static int cifs_push_posix_locks(struct cifsFileInfo *cfile);
 579
 580 /*
 581  * Try to reacquire byte range locks that were released when session
 582  * to server was lost.
 583  */
 584 static int
 585 cifs_relock_file(struct cifsFileInfo *cfile)
 586 {
 587         struct cifs_sb_info *cifs_sb = CIFS_SB(cfile->dentry->d_sb);
 588         struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
 589         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
 590         int rc = 0;
 591
 592         down_read_nested(&cinode->lock_sem, SINGLE_DEPTH_NESTING);
 593         if (cinode->can_cache_brlcks) {
 594                 /* can cache locks - no need to relock */
 595                 up_read(&cinode->lock_sem);
 596                 return rc;
 597         }
 598
 599         if (cap_unix(tcon->ses) &&
 600             (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
 601             ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
 602                 rc = cifs_push_posix_locks(cfile);
 603         else
 604                 rc = tcon->ses->server->ops->push_mand_locks(cfile);
 605
 606         up_read(&cinode->lock_sem);
 607         return rc;
 608 }
 609
 610 static int
 611 cifs_reopen_file(struct cifsFileInfo *cfile, bool can_flush)
 612 {
 613         int rc = -EACCES;
 614         unsigned int xid;
 615         __u32 oplock;
 616         struct cifs_sb_info *cifs_sb;
 617         struct cifs_tcon *tcon;
 618         struct TCP_Server_Info *server;
 619         struct cifsInodeInfo *cinode;
 620         struct inode *inode;
 621         char *full_path = NULL;
 622         int desired_access;
 623         int disposition = FILE_OPEN;
 624         int create_options = CREATE_NOT_DIR;
 625         struct cifs_open_parms oparms;
 626
 627         xid = get_xid();
 628         mutex_lock(&cfile->fh_mutex);
 629         if (!cfile->invalidHandle) {
 630                 mutex_unlock(&cfile->fh_mutex);
 631                 rc = 0;
 632                 free_xid(xid);
 633                 return rc;
 634         }
 635
 636         inode = d_inode(cfile->dentry);
 637         cifs_sb = CIFS_SB(inode->i_sb);
 638         tcon = tlink_tcon(cfile->tlink);
 639         server = tcon->ses->server;
 640
 641         /*
 642          * Can not grab rename sem here because various ops, including those
 643          * that already have the rename sem can end up causing writepage to get
 644          * called and if the server was down that means we end up here, and we
 645          * can never tell if the caller already has the rename_sem.
 646          */
 647         full_path = build_path_from_dentry(cfile->dentry);
 648         if (full_path == NULL) {
 649                 rc = -ENOMEM;
 650                 mutex_unlock(&cfile->fh_mutex);
 651                 free_xid(xid);
 652                 return rc;
 653         }
 654
 655         cifs_dbg(FYI, "inode = 0x%p file flags 0x%x for %s\n",
 656                  inode, cfile->f_flags, full_path);
 657
 658         if (tcon->ses->server->oplocks)
 659                 oplock = REQ_OPLOCK;
 660         else
 661                 oplock = 0;
 662
 663         if (tcon->unix_ext && cap_unix(tcon->ses) &&
 664             (CIFS_UNIX_POSIX_PATH_OPS_CAP &
 665                                 le64_to_cpu(tcon->fsUnixInfo.Capability))) {
 666                 /*
 667                  * O_CREAT, O_EXCL and O_TRUNC already had their effect on the
 668                  * original open. Must mask them off for a reopen.
 669                  */
 670                 unsigned int oflags = cfile->f_flags &
 671                                                 ~(O_CREAT | O_EXCL | O_TRUNC);
 672
 673                 rc = cifs_posix_open(full_path, NULL, inode->i_sb,
 674                                      cifs_sb->mnt_file_mode /* ignored */,
 675                                      oflags, &oplock, &cfile->fid.netfid, xid);
 676                 if (rc == 0) {
 677                         cifs_dbg(FYI, "posix reopen succeeded\n");
 678                         oparms.reconnect = true;
 679                         goto reopen_success;
 680                 }
 681                 /*
 682                  * fallthrough to retry open the old way on errors, especially
 683                  * in the reconnect path it is important to retry hard
 684                  */
 685         }
 686
 687         desired_access = cifs_convert_flags(cfile->f_flags);
 688
 689         if (backup_cred(cifs_sb))
 690                 create_options |= CREATE_OPEN_BACKUP_INTENT;
 691
 692         if (server->ops->get_lease_key)
 693                 server->ops->get_lease_key(inode, &cfile->fid);
 694
 695         oparms.tcon = tcon;
 696         oparms.cifs_sb = cifs_sb;
 697         oparms.desired_access = desired_access;
 698         oparms.create_options = create_options;
 699         oparms.disposition = disposition;
 700         oparms.path = full_path;
 701         oparms.fid = &cfile->fid;
 702         oparms.reconnect = true;
 703
 704         /*
 705          * Can not refresh inode by passing in file_info buf to be returned by
 706          * ops->open and then calling get_inode_info with returned buf since
 707          * file might have write behind data that needs to be flushed and server
 708          * version of file size can be stale. If we knew for sure that inode was
 709          * not dirty locally we could do this.
 710          */
 711         rc = server->ops->open(xid, &oparms, &oplock, NULL);
 712         if (rc == -ENOENT && oparms.reconnect == false) {
 713                 /* durable handle timeout is expired - open the file again */
 714                 rc = server->ops->open(xid, &oparms, &oplock, NULL);
 715                 /* indicate that we need to relock the file */
 716                 oparms.reconnect = true;
 717         }
 718
 719         if (rc) {
 720                 mutex_unlock(&cfile->fh_mutex);
 721                 cifs_dbg(FYI, "cifs_reopen returned 0x%x\n", rc);
 722                 cifs_dbg(FYI, "oplock: %d\n", oplock);
 723                 goto reopen_error_exit;
 724         }
 725
 726 reopen_success:
 727         cfile->invalidHandle = false;
 728         mutex_unlock(&cfile->fh_mutex);
 729         cinode = CIFS_I(inode);
 730
 731         if (can_flush) {
 732                 rc = filemap_write_and_wait(inode->i_mapping);
 733                 mapping_set_error(inode->i_mapping, rc);
 734
 735                 if (tcon->unix_ext)
 736                         rc = cifs_get_inode_info_unix(&inode, full_path,
 737                                                       inode->i_sb, xid);
 738                 else
 739                         rc = cifs_get_inode_info(&inode, full_path, NULL,
 740                                                  inode->i_sb, xid, NULL);
 741         }
 742         /*
 743          * Else we are writing out data to server already and could deadlock if
 744          * we tried to flush data, and since we do not know if we have data that
 745          * would invalidate the current end of file on the server we can not go
 746          * to the server to get the new inode info.
 747          */
 748
 749         /*
 750          * If the server returned a read oplock and we have mandatory brlocks,
 751          * set oplock level to None.
 752          */
 753         if (server->ops->is_read_op(oplock) && cifs_has_mand_locks(cinode)) {
 754                 cifs_dbg(FYI, "Reset oplock val from read to None due to mand locks\n");
 755                 oplock = 0;
 756         }
 757
 758         server->ops->set_fid(cfile, &cfile->fid, oplock);
 759         if (oparms.reconnect)
 760                 cifs_relock_file(cfile);
 761
 762 reopen_error_exit:
 763         kfree(full_path);
 764         free_xid(xid);
 765         return rc;
 766 }
 767
 768 int cifs_close(struct inode *inode, struct file *file)
 769 {
 770         if (file->private_data != NULL) {
 771                 cifsFileInfo_put(file->private_data);
 772                 file->private_data = NULL;
 773         }
 774
 775         /* return code from the ->release op is always ignored */
 776         return 0;
 777 }
 778
 779 void
 780 cifs_reopen_persistent_handles(struct cifs_tcon *tcon)
 781 {
 782         struct cifsFileInfo *open_file;
 783         struct list_head *tmp;
 784         struct list_head *tmp1;
 785         struct list_head tmp_list;
 786
 787         if (!tcon->use_persistent || !tcon->need_reopen_files)
 788                 return;
 789
 790         tcon->need_reopen_files = false;
 791
 792         cifs_dbg(FYI, "Reopen persistent handles");
 793         INIT_LIST_HEAD(&tmp_list);
 794
 795         /* list all files open on tree connection, reopen resilient handles  */
 796         spin_lock(&tcon->open_file_lock);
 797         list_for_each(tmp, &tcon->openFileList) {
 798                 open_file = list_entry(tmp, struct cifsFileInfo, tlist);
 799                 if (!open_file->invalidHandle)
 800                         continue;
 801                 cifsFileInfo_get(open_file);
 802                 list_add_tail(&open_file->rlist, &tmp_list);
 803         }
 804         spin_unlock(&tcon->open_file_lock);
 805
 806         list_for_each_safe(tmp, tmp1, &tmp_list) {
 807                 open_file = list_entry(tmp, struct cifsFileInfo, rlist);
 808                 if (cifs_reopen_file(open_file, false /* do not flush */))
 809                         tcon->need_reopen_files = true;
 810                 list_del_init(&open_file->rlist);
 811                 cifsFileInfo_put(open_file);
 812         }
 813 }
 814
 815 int cifs_closedir(struct inode *inode, struct file *file)
 816 {
 817         int rc = 0;
 818         unsigned int xid;
 819         struct cifsFileInfo *cfile = file->private_data;
 820         struct cifs_tcon *tcon;
 821         struct TCP_Server_Info *server;
 822         char *buf;
 823
 824         cifs_dbg(FYI, "Closedir inode = 0x%p\n", inode);
 825
 826         if (cfile == NULL)
 827                 return rc;
 828
 829         xid = get_xid();
 830         tcon = tlink_tcon(cfile->tlink);
 831         server = tcon->ses->server;
 832
 833         cifs_dbg(FYI, "Freeing private data in close dir\n");
 834         spin_lock(&cfile->file_info_lock);
 835         if (server->ops->dir_needs_close(cfile)) {
 836                 cfile->invalidHandle = true;
 837                 spin_unlock(&cfile->file_info_lock);
 838                 if (server->ops->close_dir)
 839                         rc = server->ops->close_dir(xid, tcon, &cfile->fid);
 840                 else
 841                         rc = -ENOSYS;
 842                 cifs_dbg(FYI, "Closing uncompleted readdir with rc %d\n", rc);
 843                 /* not much we can do if it fails anyway, ignore rc */
 844                 rc = 0;
 845         } else
 846                 spin_unlock(&cfile->file_info_lock);
 847
 848         buf = cfile->srch_inf.ntwrk_buf_start;
 849         if (buf) {
 850                 cifs_dbg(FYI, "closedir free smb buf in srch struct\n");
 851                 cfile->srch_inf.ntwrk_buf_start = NULL;
 852                 if (cfile->srch_inf.smallBuf)
 853                         cifs_small_buf_release(buf);
 854                 else
 855                         cifs_buf_release(buf);
 856         }
 857
 858         cifs_put_tlink(cfile->tlink);
 859         kfree(file->private_data);
 860         file->private_data = NULL;
 861         /* BB can we lock the filestruct while this is going on? */
 862         free_xid(xid);
 863         return rc;
 864 }
 865
 866 static struct cifsLockInfo *
 867 cifs_lock_init(__u64 offset, __u64 length, __u8 type)
 868 {
 869         struct cifsLockInfo *lock =
 870                 kmalloc(sizeof(struct cifsLockInfo), GFP_KERNEL);
 871         if (!lock)
 872                 return lock;
 873         lock->offset = offset;
 874         lock->length = length;
 875         lock->type = type;
 876         lock->pid = current->tgid;
 877         INIT_LIST_HEAD(&lock->blist);
 878         init_waitqueue_head(&lock->block_q);
 879         return lock;
 880 }
 881
 882 void
 883 cifs_del_lock_waiters(struct cifsLockInfo *lock)
 884 {
 885         struct cifsLockInfo *li, *tmp;
 886         list_for_each_entry_safe(li, tmp, &lock->blist, blist) {
 887                 list_del_init(&li->blist);
 888                 wake_up(&li->block_q);
 889         }
 890 }
 891
 892 #define CIFS_LOCK_OP    0
 893 #define CIFS_READ_OP    1
 894 #define CIFS_WRITE_OP   2
 895
 896 /* @rw_check : 0 - no op, 1 - read, 2 - write */
 897 static bool
 898 cifs_find_fid_lock_conflict(struct cifs_fid_locks *fdlocks, __u64 offset,
 899                             __u64 length, __u8 type, struct cifsFileInfo *cfile,
 900                             struct cifsLockInfo **conf_lock, int rw_check)
 901 {
 902         struct cifsLockInfo *li;
 903         struct cifsFileInfo *cur_cfile = fdlocks->cfile;
 904         struct TCP_Server_Info *server = tlink_tcon(cfile->tlink)->ses->server;
 905
 906         list_for_each_entry(li, &fdlocks->locks, llist) {
 907                 if (offset + length <= li->offset ||
 908                     offset >= li->offset + li->length)
 909                         continue;
 910                 if (rw_check != CIFS_LOCK_OP && current->tgid == li->pid &&
 911                     server->ops->compare_fids(cfile, cur_cfile)) {
 912                         /* shared lock prevents write op through the same fid */
 913                         if (!(li->type & server->vals->shared_lock_type) ||
 914                             rw_check != CIFS_WRITE_OP)
 915                                 continue;
 916                 }
 917                 if ((type & server->vals->shared_lock_type) &&
 918                     ((server->ops->compare_fids(cfile, cur_cfile) &&
 919                      current->tgid == li->pid) || type == li->type))
 920                         continue;
 921                 if (conf_lock)
 922                         *conf_lock = li;
 923                 return true;
 924         }
 925         return false;
 926 }
 927
 928 bool
 929 cifs_find_lock_conflict(struct cifsFileInfo *cfile, __u64 offset, __u64 length,
 930                         __u8 type, struct cifsLockInfo **conf_lock,
 931                         int rw_check)
 932 {
 933         bool rc = false;
 934         struct cifs_fid_locks *cur;
 935         struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
 936
 937         list_for_each_entry(cur, &cinode->llist, llist) {
 938                 rc = cifs_find_fid_lock_conflict(cur, offset, length, type,
 939                                                  cfile, conf_lock, rw_check);
 940                 if (rc)
 941                         break;
 942         }
 943
 944         return rc;
 945 }
 946
 947 /*
 948  * Check if there is another lock that prevents us to set the lock (mandatory
 949  * style). If such a lock exists, update the flock structure with its
 950  * properties. Otherwise, set the flock type to F_UNLCK if we can cache brlocks
 951  * or leave it the same if we can't. Returns 0 if we don't need to request to
 952  * the server or 1 otherwise.
 953  */
 954 static int
 955 cifs_lock_test(struct cifsFileInfo *cfile, __u64 offset, __u64 length,
 956                __u8 type, struct file_lock *flock)
 957 {
 958         int rc = 0;
 959         struct cifsLockInfo *conf_lock;
 960         struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
 961         struct TCP_Server_Info *server = tlink_tcon(cfile->tlink)->ses->server;
 962         bool exist;
 963
 964         down_read(&cinode->lock_sem);
 965
 966         exist = cifs_find_lock_conflict(cfile, offset, length, type,
 967                                         &conf_lock, CIFS_LOCK_OP);
 968         if (exist) {
 969                 flock->fl_start = conf_lock->offset;
 970                 flock->fl_end = conf_lock->offset + conf_lock->length - 1;
 971                 flock->fl_pid = conf_lock->pid;
 972                 if (conf_lock->type & server->vals->shared_lock_type)
 973                         flock->fl_type = F_RDLCK;
 974                 else
 975                         flock->fl_type = F_WRLCK;
 976         } else if (!cinode->can_cache_brlcks)
 977                 rc = 1;
 978         else
 979                 flock->fl_type = F_UNLCK;
 980
 981         up_read(&cinode->lock_sem);
 982         return rc;
 983 }
 984
 985 static void
 986 cifs_lock_add(struct cifsFileInfo *cfile, struct cifsLockInfo *lock)
 987 {
 988         struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
 989         down_write(&cinode->lock_sem);
 990         list_add_tail(&lock->llist, &cfile->llist->locks);
 991         up_write(&cinode->lock_sem);
 992 }
 993
 994 /*
 995  * Set the byte-range lock (mandatory style). Returns:
 996  * 1) 0, if we set the lock and don't need to request to the server;
 997  * 2) 1, if no locks prevent us but we need to request to the server;
 998  * 3) -EACCESS, if there is a lock that prevents us and wait is false.
 999  */
1000 static int
1001 cifs_lock_add_if(struct cifsFileInfo *cfile, struct cifsLockInfo *lock,
1002                  bool wait)
1003 {
1004         struct cifsLockInfo *conf_lock;
1005         struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
1006         bool exist;
1007         int rc = 0;
1008
1009 try_again:
1010         exist = false;
1011         down_write(&cinode->lock_sem);
1012
1013         exist = cifs_find_lock_conflict(cfile, lock->offset, lock->length,
1014                                         lock->type, &conf_lock, CIFS_LOCK_OP);
1015         if (!exist && cinode->can_cache_brlcks) {
1016                 list_add_tail(&lock->llist, &cfile->llist->locks);
1017                 up_write(&cinode->lock_sem);
1018                 return rc;
1019         }
1020
1021         if (!exist)
1022                 rc = 1;
1023         else if (!wait)
1024                 rc = -EACCES;
1025         else {
1026                 list_add_tail(&lock->blist, &conf_lock->blist);
1027                 up_write(&cinode->lock_sem);
1028                 rc = wait_event_interruptible(lock->block_q,
1029                                         (lock->blist.prev == &lock->blist) &&
1030                                         (lock->blist.next == &lock->blist));
1031                 if (!rc)
1032                         goto try_again;
1033                 down_write(&cinode->lock_sem);
1034                 list_del_init(&lock->blist);
1035         }
1036
1037         up_write(&cinode->lock_sem);
1038         return rc;
1039 }
1040
1041 /*
1042  * Check if there is another lock that prevents us to set the lock (posix
1043  * style). If such a lock exists, update the flock structure with its
1044  * properties. Otherwise, set the flock type to F_UNLCK if we can cache brlocks
1045  * or leave it the same if we can't. Returns 0 if we don't need to request to
1046  * the server or 1 otherwise.
1047  */
1048 static int
1049 cifs_posix_lock_test(struct file *file, struct file_lock *flock)
1050 {
1051         int rc = 0;
1052         struct cifsInodeInfo *cinode = CIFS_I(file_inode(file));
1053         unsigned char saved_type = flock->fl_type;
1054
1055         if ((flock->fl_flags & FL_POSIX) == 0)
1056                 return 1;
1057
1058         down_read(&cinode->lock_sem);
1059         posix_test_lock(file, flock);
1060
1061         if (flock->fl_type == F_UNLCK && !cinode->can_cache_brlcks) {
1062                 flock->fl_type = saved_type;
1063                 rc = 1;
1064         }
1065
1066         up_read(&cinode->lock_sem);
1067         return rc;
1068 }
1069
1070 /*
1071  * Set the byte-range lock (posix style). Returns:
1072  * 1) 0, if we set the lock and don't need to request to the server;
1073  * 2) 1, if we need to request to the server;
1074  * 3) <0, if the error occurs while setting the lock.
1075  */
1076 static int
1077 cifs_posix_lock_set(struct file *file, struct file_lock *flock)
1078 {
1079         struct cifsInodeInfo *cinode = CIFS_I(file_inode(file));
1080         int rc = 1;
1081
1082         if ((flock->fl_flags & FL_POSIX) == 0)
1083                 return rc;
1084
1085 try_again:
1086         down_write(&cinode->lock_sem);
1087         if (!cinode->can_cache_brlcks) {
1088                 up_write(&cinode->lock_sem);
1089                 return rc;
1090         }
1091
1092         rc = posix_lock_file(file, flock, NULL);
1093         up_write(&cinode->lock_sem);
1094         if (rc == FILE_LOCK_DEFERRED) {
1095                 rc = wait_event_interruptible(flock->fl_wait, !flock->fl_next);
1096                 if (!rc)
1097                         goto try_again;
1098                 posix_unblock_lock(flock);
1099         }
1100         return rc;
1101 }
1102
1103 int
1104 cifs_push_mandatory_locks(struct cifsFileInfo *cfile)
1105 {
1106         unsigned int xid;
1107         int rc = 0, stored_rc;
1108         struct cifsLockInfo *li, *tmp;
1109         struct cifs_tcon *tcon;
1110         unsigned int num, max_num, max_buf;
1111         LOCKING_ANDX_RANGE *buf, *cur;
1112         static const int types[] = {
1113                 LOCKING_ANDX_LARGE_FILES,
1114                 LOCKING_ANDX_SHARED_LOCK | LOCKING_ANDX_LARGE_FILES
1115         };
1116         int i;
1117
1118         xid = get_xid();
1119         tcon = tlink_tcon(cfile->tlink);
1120
1121         /*
1122          * Accessing maxBuf is racy with cifs_reconnect - need to store value
1123          * and check it for zero before using.
1124          */
1125         max_buf = tcon->ses->server->maxBuf;
1126         if (!max_buf) {
1127                 free_xid(xid);
1128                 return -EINVAL;
1129         }
1130
1131         max_num = (max_buf - sizeof(struct smb_hdr)) /
1132                                                 sizeof(LOCKING_ANDX_RANGE);
1133         buf = kcalloc(max_num, sizeof(LOCKING_ANDX_RANGE), GFP_KERNEL);
1134         if (!buf) {
1135                 free_xid(xid);
1136                 return -ENOMEM;
1137         }
1138
1139         for (i = 0; i < 2; i++) {
1140                 cur = buf;
1141                 num = 0;
1142                 list_for_each_entry_safe(li, tmp, &cfile->llist->locks, llist) {
1143                         if (li->type != types[i])
1144                                 continue;
1145                         cur->Pid = cpu_to_le16(li->pid);
1146                         cur->LengthLow = cpu_to_le32((u32)li->length);
1147                         cur->LengthHigh = cpu_to_le32((u32)(li->length>>32));
1148                         cur->OffsetLow = cpu_to_le32((u32)li->offset);
1149                         cur->OffsetHigh = cpu_to_le32((u32)(li->offset>>32));
1150                         if (++num == max_num) {
1151                                 stored_rc = cifs_lockv(xid, tcon,
1152                                                        cfile->fid.netfid,
1153                                                        (__u8)li->type, 0, num,
1154                                                        buf);
1155                                 if (stored_rc)
1156                                         rc = stored_rc;
1157                                 cur = buf;
1158                                 num = 0;
1159                         } else
1160                                 cur++;
1161                 }
1162
1163                 if (num) {
1164                         stored_rc = cifs_lockv(xid, tcon, cfile->fid.netfid,
1165                                                (__u8)types[i], 0, num, buf);
1166                         if (stored_rc)
1167                                 rc = stored_rc;
1168                 }
1169         }
1170
1171         kfree(buf);
1172         free_xid(xid);
1173         return rc;
1174 }
1175
1176 static __u32
1177 hash_lockowner(fl_owner_t owner)
1178 {
1179         return cifs_lock_secret ^ hash32_ptr((const void *)owner);
1180 }
1181
1182 struct lock_to_push {
1183         struct list_head llist;
1184         __u64 offset;
1185         __u64 length;
1186         __u32 pid;
1187         __u16 netfid;
1188         __u8 type;
1189 };
1190
1191 static int
1192 cifs_push_posix_locks(struct cifsFileInfo *cfile)
1193 {
1194         struct inode *inode = d_inode(cfile->dentry);
1195         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1196         struct file_lock *flock;
1197         struct file_lock_context *flctx = inode->i_flctx;
1198         unsigned int count = 0, i;
1199         int rc = 0, xid, type;
1200         struct list_head locks_to_send, *el;
1201         struct lock_to_push *lck, *tmp;
1202         __u64 length;
1203
1204         xid = get_xid();
1205
1206         if (!flctx)
1207                 goto out;
1208
1209         spin_lock(&flctx->flc_lock);
1210         list_for_each(el, &flctx->flc_posix) {
1211                 count++;
1212         }
1213         spin_unlock(&flctx->flc_lock);
1214
1215         INIT_LIST_HEAD(&locks_to_send);
1216
1217         /*
1218          * Allocating count locks is enough because no FL_POSIX locks can be
1219          * added to the list while we are holding cinode->lock_sem that
1220          * protects locking operations of this inode.
1221          */
1222         for (i = 0; i < count; i++) {
1223                 lck = kmalloc(sizeof(struct lock_to_push), GFP_KERNEL);
1224                 if (!lck) {
1225                         rc = -ENOMEM;
1226                         goto err_out;
1227                 }
1228                 list_add_tail(&lck->llist, &locks_to_send);
1229         }
1230
1231         el = locks_to_send.next;
1232         spin_lock(&flctx->flc_lock);
1233         list_for_each_entry(flock, &flctx->flc_posix, fl_list) {
1234                 if (el == &locks_to_send) {
1235                         /*
1236                          * The list ended. We don't have enough allocated
1237                          * structures - something is really wrong.
1238                          */
1239                         cifs_dbg(VFS, "Can't push all brlocks!\n");
1240                         break;
1241                 }
1242                 length = 1 + flock->fl_end - flock->fl_start;
1243                 if (flock->fl_type == F_RDLCK || flock->fl_type == F_SHLCK)
1244                         type = CIFS_RDLCK;
1245                 else
1246                         type = CIFS_WRLCK;
1247                 lck = list_entry(el, struct lock_to_push, llist);
1248                 lck->pid = hash_lockowner(flock->fl_owner);
1249                 lck->netfid = cfile->fid.netfid;
1250                 lck->length = length;
1251                 lck->type = type;
1252                 lck->offset = flock->fl_start;
1253         }
1254         spin_unlock(&flctx->flc_lock);
1255
1256         list_for_each_entry_safe(lck, tmp, &locks_to_send, llist) {
1257                 int stored_rc;
1258
1259                 stored_rc = CIFSSMBPosixLock(xid, tcon, lck->netfid, lck->pid,
1260                                              lck->offset, lck->length, NULL,
1261                                              lck->type, 0);
1262                 if (stored_rc)
1263                         rc = stored_rc;
1264                 list_del(&lck->llist);
1265                 kfree(lck);
1266         }
1267
1268 out:
1269         free_xid(xid);
1270         return rc;
1271 err_out:
1272         list_for_each_entry_safe(lck, tmp, &locks_to_send, llist) {
1273                 list_del(&lck->llist);
1274                 kfree(lck);
1275         }
1276         goto out;
1277 }
1278
1279 static int
1280 cifs_push_locks(struct cifsFileInfo *cfile)
1281 {
1282         struct cifs_sb_info *cifs_sb = CIFS_SB(cfile->dentry->d_sb);
1283         struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
1284         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1285         int rc = 0;
1286
1287         /* we are going to update can_cache_brlcks here - need a write access */
1288         down_write(&cinode->lock_sem);
1289         if (!cinode->can_cache_brlcks) {
1290                 up_write(&cinode->lock_sem);
1291                 return rc;
1292         }
1293
1294         if (cap_unix(tcon->ses) &&
1295             (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
1296             ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
1297                 rc = cifs_push_posix_locks(cfile);
1298         else
1299                 rc = tcon->ses->server->ops->push_mand_locks(cfile);
1300
1301         cinode->can_cache_brlcks = false;
1302         up_write(&cinode->lock_sem);
1303         return rc;
1304 }
1305
1306 static void
1307 cifs_read_flock(struct file_lock *flock, __u32 *type, int *lock, int *unlock,
1308                 bool *wait_flag, struct TCP_Server_Info *server)
1309 {
1310         if (flock->fl_flags & FL_POSIX)
1311                 cifs_dbg(FYI, "Posix\n");
1312         if (flock->fl_flags & FL_FLOCK)
1313                 cifs_dbg(FYI, "Flock\n");
1314         if (flock->fl_flags & FL_SLEEP) {
1315                 cifs_dbg(FYI, "Blocking lock\n");
1316                 *wait_flag = true;
1317         }
1318         if (flock->fl_flags & FL_ACCESS)
1319                 cifs_dbg(FYI, "Process suspended by mandatory locking - not implemented yet\n");
1320         if (flock->fl_flags & FL_LEASE)
1321                 cifs_dbg(FYI, "Lease on file - not implemented yet\n");
1322         if (flock->fl_flags &
1323             (~(FL_POSIX | FL_FLOCK | FL_SLEEP |
1324                FL_ACCESS | FL_LEASE | FL_CLOSE)))
1325                 cifs_dbg(FYI, "Unknown lock flags 0x%x\n", flock->fl_flags);
1326
1327         *type = server->vals->large_lock_type;
1328         if (flock->fl_type == F_WRLCK) {
1329                 cifs_dbg(FYI, "F_WRLCK\n");
1330                 *type |= server->vals->exclusive_lock_type;
1331                 *lock = 1;
1332         } else if (flock->fl_type == F_UNLCK) {
1333                 cifs_dbg(FYI, "F_UNLCK\n");
1334                 *type |= server->vals->unlock_lock_type;
1335                 *unlock = 1;
1336                 /* Check if unlock includes more than one lock range */
1337         } else if (flock->fl_type == F_RDLCK) {
1338                 cifs_dbg(FYI, "F_RDLCK\n");
1339                 *type |= server->vals->shared_lock_type;
1340                 *lock = 1;
1341         } else if (flock->fl_type == F_EXLCK) {
1342                 cifs_dbg(FYI, "F_EXLCK\n");
1343                 *type |= server->vals->exclusive_lock_type;
1344                 *lock = 1;
1345         } else if (flock->fl_type == F_SHLCK) {
1346                 cifs_dbg(FYI, "F_SHLCK\n");
1347                 *type |= server->vals->shared_lock_type;
1348                 *lock = 1;
1349         } else
1350                 cifs_dbg(FYI, "Unknown type of lock\n");
1351 }
1352
1353 static int
1354 cifs_getlk(struct file *file, struct file_lock *flock, __u32 type,
1355            bool wait_flag, bool posix_lck, unsigned int xid)
1356 {
1357         int rc = 0;
1358         __u64 length = 1 + flock->fl_end - flock->fl_start;
1359         struct cifsFileInfo *cfile = (struct cifsFileInfo *)file->private_data;
1360         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1361         struct TCP_Server_Info *server = tcon->ses->server;
1362         __u16 netfid = cfile->fid.netfid;
1363
1364         if (posix_lck) {
1365                 int posix_lock_type;
1366
1367                 rc = cifs_posix_lock_test(file, flock);
1368                 if (!rc)
1369                         return rc;
1370
1371                 if (type & server->vals->shared_lock_type)
1372                         posix_lock_type = CIFS_RDLCK;
1373                 else
1374                         posix_lock_type = CIFS_WRLCK;
1375                 rc = CIFSSMBPosixLock(xid, tcon, netfid,
1376                                       hash_lockowner(flock->fl_owner),
1377                                       flock->fl_start, length, flock,
1378                                       posix_lock_type, wait_flag);
1379                 return rc;
1380         }
1381
1382         rc = cifs_lock_test(cfile, flock->fl_start, length, type, flock);
1383         if (!rc)
1384                 return rc;
1385
1386         /* BB we could chain these into one lock request BB */
1387         rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length, type,
1388                                     1, 0, false);
1389         if (rc == 0) {
1390                 rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length,
1391                                             type, 0, 1, false);
1392                 flock->fl_type = F_UNLCK;
1393                 if (rc != 0)
1394                         cifs_dbg(VFS, "Error unlocking previously locked range %d during test of lock\n",
1395                                  rc);
1396                 return 0;
1397         }
1398
1399         if (type & server->vals->shared_lock_type) {
1400                 flock->fl_type = F_WRLCK;
1401                 return 0;
1402         }
1403
1404         type &= ~server->vals->exclusive_lock_type;
1405
1406         rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length,
1407                                     type | server->vals->shared_lock_type,
1408                                     1, 0, false);
1409         if (rc == 0) {
1410                 rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length,
1411                         type | server->vals->shared_lock_type, 0, 1, false);
1412                 flock->fl_type = F_RDLCK;
1413                 if (rc != 0)
1414                         cifs_dbg(VFS, "Error unlocking previously locked range %d during test of lock\n",
1415                                  rc);
1416         } else
1417                 flock->fl_type = F_WRLCK;
1418
1419         return 0;
1420 }
1421
1422 void
1423 cifs_move_llist(struct list_head *source, struct list_head *dest)
1424 {
1425         struct list_head *li, *tmp;
1426         list_for_each_safe(li, tmp, source)
1427                 list_move(li, dest);
1428 }
1429
1430 void
1431 cifs_free_llist(struct list_head *llist)
1432 {
1433         struct cifsLockInfo *li, *tmp;
1434         list_for_each_entry_safe(li, tmp, llist, llist) {
1435                 cifs_del_lock_waiters(li);
1436                 list_del(&li->llist);
1437                 kfree(li);
1438         }
1439 }
1440
1441 int
1442 cifs_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock,
1443                   unsigned int xid)
1444 {
1445         int rc = 0, stored_rc;
1446         static const int types[] = {
1447                 LOCKING_ANDX_LARGE_FILES,
1448                 LOCKING_ANDX_SHARED_LOCK | LOCKING_ANDX_LARGE_FILES
1449         };
1450         unsigned int i;
1451         unsigned int max_num, num, max_buf;
1452         LOCKING_ANDX_RANGE *buf, *cur;
1453         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1454         struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
1455         struct cifsLockInfo *li, *tmp;
1456         __u64 length = 1 + flock->fl_end - flock->fl_start;
1457         struct list_head tmp_llist;
1458
1459         INIT_LIST_HEAD(&tmp_llist);
1460
1461         /*
1462          * Accessing maxBuf is racy with cifs_reconnect - need to store value
1463          * and check it for zero before using.
1464          */
1465         max_buf = tcon->ses->server->maxBuf;
1466         if (!max_buf)
1467                 return -EINVAL;
1468
1469         max_num = (max_buf - sizeof(struct smb_hdr)) /
1470                                                 sizeof(LOCKING_ANDX_RANGE);
1471         buf = kcalloc(max_num, sizeof(LOCKING_ANDX_RANGE), GFP_KERNEL);
1472         if (!buf)
1473                 return -ENOMEM;
1474
1475         down_write(&cinode->lock_sem);
1476         for (i = 0; i < 2; i++) {
1477                 cur = buf;
1478                 num = 0;
1479                 list_for_each_entry_safe(li, tmp, &cfile->llist->locks, llist) {
1480                         if (flock->fl_start > li->offset ||
1481                             (flock->fl_start + length) <
1482                             (li->offset + li->length))
1483                                 continue;
1484                         if (current->tgid != li->pid)
1485                                 continue;
1486                         if (types[i] != li->type)
1487                                 continue;
1488                         if (cinode->can_cache_brlcks) {
1489                                 /*
1490                                  * We can cache brlock requests - simply remove
1491                                  * a lock from the file's list.
1492                                  */
1493                                 list_del(&li->llist);
1494                                 cifs_del_lock_waiters(li);
1495                                 kfree(li);
1496                                 continue;
1497                         }
1498                         cur->Pid = cpu_to_le16(li->pid);
1499                         cur->LengthLow = cpu_to_le32((u32)li->length);
1500                         cur->LengthHigh = cpu_to_le32((u32)(li->length>>32));
1501                         cur->OffsetLow = cpu_to_le32((u32)li->offset);
1502                         cur->OffsetHigh = cpu_to_le32((u32)(li->offset>>32));
1503                         /*
1504                          * We need to save a lock here to let us add it again to
1505                          * the file's list if the unlock range request fails on
1506                          * the server.
1507                          */
1508                         list_move(&li->llist, &tmp_llist);
1509                         if (++num == max_num) {
1510                                 stored_rc = cifs_lockv(xid, tcon,
1511                                                        cfile->fid.netfid,
1512                                                        li->type, num, 0, buf);
1513                                 if (stored_rc) {
1514                                         /*
1515                                          * We failed on the unlock range
1516                                          * request - add all locks from the tmp
1517                                          * list to the head of the file's list.
1518                                          */
1519                                         cifs_move_llist(&tmp_llist,
1520                                                         &cfile->llist->locks);
1521                                         rc = stored_rc;
1522                                 } else
1523                                         /*
1524                                          * The unlock range request succeed -
1525                                          * free the tmp list.
1526                                          */
1527                                         cifs_free_llist(&tmp_llist);
1528                                 cur = buf;
1529                                 num = 0;
1530                         } else
1531                                 cur++;
1532                 }
1533                 if (num) {
1534                         stored_rc = cifs_lockv(xid, tcon, cfile->fid.netfid,
1535                                                types[i], num, 0, buf);
1536                         if (stored_rc) {
1537                                 cifs_move_llist(&tmp_llist,
1538                                                 &cfile->llist->locks);
1539                                 rc = stored_rc;
1540                         } else
1541                                 cifs_free_llist(&tmp_llist);
1542                 }
1543         }
1544
1545         up_write(&cinode->lock_sem);
1546         kfree(buf);
1547         return rc;
1548 }
1549
1550 static int
1551 cifs_setlk(struct file *file, struct file_lock *flock, __u32 type,
1552            bool wait_flag, bool posix_lck, int lock, int unlock,
1553            unsigned int xid)
1554 {
1555         int rc = 0;
1556         __u64 length = 1 + flock->fl_end - flock->fl_start;
1557         struct cifsFileInfo *cfile = (struct cifsFileInfo *)file->private_data;
1558         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1559         struct TCP_Server_Info *server = tcon->ses->server;
1560         struct inode *inode = d_inode(cfile->dentry);
1561
1562         if (posix_lck) {
1563                 int posix_lock_type;
1564
1565                 rc = cifs_posix_lock_set(file, flock);
1566                 if (!rc || rc < 0)
1567                         return rc;
1568
1569                 if (type & server->vals->shared_lock_type)
1570                         posix_lock_type = CIFS_RDLCK;
1571                 else
1572                         posix_lock_type = CIFS_WRLCK;
1573
1574                 if (unlock == 1)
1575                         posix_lock_type = CIFS_UNLCK;
1576
1577                 rc = CIFSSMBPosixLock(xid, tcon, cfile->fid.netfid,
1578                                       hash_lockowner(flock->fl_owner),
1579                                       flock->fl_start, length,
1580                                       NULL, posix_lock_type, wait_flag);
1581                 goto out;
1582         }
1583
1584         if (lock) {
1585                 struct cifsLockInfo *lock;
1586
1587                 lock = cifs_lock_init(flock->fl_start, length, type);
1588                 if (!lock)
1589                         return -ENOMEM;
1590
1591                 rc = cifs_lock_add_if(cfile, lock, wait_flag);
1592                 if (rc < 0) {
1593                         kfree(lock);
1594                         return rc;
1595                 }
1596                 if (!rc)
1597                         goto out;
1598
1599                 /*
1600                  * Windows 7 server can delay breaking lease from read to None
1601                  * if we set a byte-range lock on a file - break it explicitly
1602                  * before sending the lock to the server to be sure the next
1603                  * read won't conflict with non-overlapted locks due to
1604                  * pagereading.
1605                  */
1606                 if (!CIFS_CACHE_WRITE(CIFS_I(inode)) &&
1607                                         CIFS_CACHE_READ(CIFS_I(inode))) {
1608                         cifs_zap_mapping(inode);
1609                         cifs_dbg(FYI, "Set no oplock for inode=%p due to mand locks\n",
1610                                  inode);
1611                         CIFS_I(inode)->oplock = 0;
1612                 }
1613
1614                 rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length,
1615                                             type, 1, 0, wait_flag);
1616                 if (rc) {
1617                         kfree(lock);
1618                         return rc;
1619                 }
1620
1621                 cifs_lock_add(cfile, lock);
1622         } else if (unlock)
1623                 rc = server->ops->mand_unlock_range(cfile, flock, xid);
1624
1625 out:
1626         if (flock->fl_flags & FL_POSIX && !rc)
1627                 rc = locks_lock_file_wait(file, flock);
1628         return rc;
1629 }
1630
1631 int cifs_lock(struct file *file, int cmd, struct file_lock *flock)
1632 {
1633         int rc, xid;
1634         int lock = 0, unlock = 0;
1635         bool wait_flag = false;
1636         bool posix_lck = false;
1637         struct cifs_sb_info *cifs_sb;
1638         struct cifs_tcon *tcon;
1639         struct cifsInodeInfo *cinode;
1640         struct cifsFileInfo *cfile;
1641         __u16 netfid;
1642         __u32 type;
1643
1644         rc = -EACCES;
1645         xid = get_xid();
1646
1647         cifs_dbg(FYI, "Lock parm: 0x%x flockflags: 0x%x flocktype: 0x%x start: %lld end: %lld\n",
1648                  cmd, flock->fl_flags, flock->fl_type,
1649                  flock->fl_start, flock->fl_end);
1650
1651         cfile = (struct cifsFileInfo *)file->private_data;
1652         tcon = tlink_tcon(cfile->tlink);
1653
1654         cifs_read_flock(flock, &type, &lock, &unlock, &wait_flag,
1655                         tcon->ses->server);
1656
1657         cifs_sb = CIFS_FILE_SB(file);
1658         netfid = cfile->fid.netfid;
1659         cinode = CIFS_I(file_inode(file));
1660
1661         if (cap_unix(tcon->ses) &&
1662             (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
1663             ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
1664                 posix_lck = true;
1665         /*
1666          * BB add code here to normalize offset and length to account for
1667          * negative length which we can not accept over the wire.
1668          */
1669         if (IS_GETLK(cmd)) {
1670                 rc = cifs_getlk(file, flock, type, wait_flag, posix_lck, xid);
1671                 free_xid(xid);
1672                 return rc;
1673         }
1674
1675         if (!lock && !unlock) {
1676                 /*
1677                  * if no lock or unlock then nothing to do since we do not
1678                  * know what it is
1679                  */
1680                 free_xid(xid);
1681                 return -EOPNOTSUPP;
1682         }
1683
1684         rc = cifs_setlk(file, flock, type, wait_flag, posix_lck, lock, unlock,
1685                         xid);
1686         free_xid(xid);
1687         return rc;
1688 }
1689
1690 /*
1691  * update the file size (if needed) after a write. Should be called with
1692  * the inode->i_lock held
1693  */
1694 void
1695 cifs_update_eof(struct cifsInodeInfo *cifsi, loff_t offset,
1696                       unsigned int bytes_written)
1697 {
1698         loff_t end_of_write = offset + bytes_written;
1699
1700         if (end_of_write > cifsi->server_eof)
1701                 cifsi->server_eof = end_of_write;
1702 }
1703
1704 static ssize_t
1705 cifs_write(struct cifsFileInfo *open_file, __u32 pid, const char *write_data,
1706            size_t write_size, loff_t *offset)
1707 {
1708         int rc = 0;
1709         unsigned int bytes_written = 0;
1710         unsigned int total_written;
1711         struct cifs_sb_info *cifs_sb;
1712         struct cifs_tcon *tcon;
1713         struct TCP_Server_Info *server;
1714         unsigned int xid;
1715         struct dentry *dentry = open_file->dentry;
1716         struct cifsInodeInfo *cifsi = CIFS_I(d_inode(dentry));
1717         struct cifs_io_parms io_parms;
1718
1719         cifs_sb = CIFS_SB(dentry->d_sb);
1720
1721         cifs_dbg(FYI, "write %zd bytes to offset %lld of %pd\n",
1722                  write_size, *offset, dentry);
1723
1724         tcon = tlink_tcon(open_file->tlink);
1725         server = tcon->ses->server;
1726
1727         if (!server->ops->sync_write)
1728                 return -ENOSYS;
1729
1730         xid = get_xid();
1731
1732         for (total_written = 0; write_size > total_written;
1733              total_written += bytes_written) {
1734                 rc = -EAGAIN;
1735                 while (rc == -EAGAIN) {
1736                         struct kvec iov[2];
1737                         unsigned int len;
1738
1739                         if (open_file->invalidHandle) {
1740                                 /* we could deadlock if we called
1741                                    filemap_fdatawait from here so tell
1742                                    reopen_file not to flush data to
1743                                    server now */
1744                                 rc = cifs_reopen_file(open_file, false);
1745                                 if (rc != 0)
1746                                         break;
1747                         }
1748
1749                         len = min(server->ops->wp_retry_size(d_inode(dentry)),
1750                                   (unsigned int)write_size - total_written);
1751                         /* iov[0] is reserved for smb header */
1752                         iov[1].iov_base = (char *)write_data + total_written;
1753                         iov[1].iov_len = len;
1754                         io_parms.pid = pid;
1755                         io_parms.tcon = tcon;
1756                         io_parms.offset = *offset;
1757                         io_parms.length = len;
1758                         rc = server->ops->sync_write(xid, &open_file->fid,
1759                                         &io_parms, &bytes_written, iov, 1);
1760                 }
1761                 if (rc || (bytes_written == 0)) {
1762                         if (total_written)
1763                                 break;
1764                         else {
1765                                 free_xid(xid);
1766                                 return rc;
1767                         }
1768                 } else {
1769                         spin_lock(&d_inode(dentry)->i_lock);
1770                         cifs_update_eof(cifsi, *offset, bytes_written);
1771                         spin_unlock(&d_inode(dentry)->i_lock);
1772                         *offset += bytes_written;
1773                 }
1774         }
1775
1776         cifs_stats_bytes_written(tcon, total_written);
1777
1778         if (total_written > 0) {
1779                 spin_lock(&d_inode(dentry)->i_lock);
1780                 if (*offset > d_inode(dentry)->i_size)
1781                         i_size_write(d_inode(dentry), *offset);
1782                 spin_unlock(&d_inode(dentry)->i_lock);
1783         }
1784         mark_inode_dirty_sync(d_inode(dentry));
1785         free_xid(xid);
1786         return total_written;
1787 }
1788
1789 struct cifsFileInfo *find_readable_file(struct cifsInodeInfo *cifs_inode,
1790                                         bool fsuid_only)
1791 {
1792         struct cifsFileInfo *open_file = NULL;
1793         struct cifs_sb_info *cifs_sb = CIFS_SB(cifs_inode->vfs_inode.i_sb);
1794         struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
1795
1796         /* only filter by fsuid on multiuser mounts */
1797         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
1798                 fsuid_only = false;
1799
1800         spin_lock(&tcon->open_file_lock);
1801         /* we could simply get the first_list_entry since write-only entries
1802            are always at the end of the list but since the first entry might
1803            have a close pending, we go through the whole list */
1804         list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
1805                 if (fsuid_only && !uid_eq(open_file->uid, current_fsuid()))
1806                         continue;
1807                 if (OPEN_FMODE(open_file->f_flags) & FMODE_READ) {
1808                         if (!open_file->invalidHandle) {
1809                                 /* found a good file */
1810                                 /* lock it so it will not be closed on us */
1811                                 cifsFileInfo_get(open_file);
1812                                 spin_unlock(&tcon->open_file_lock);
1813                                 return open_file;
1814                         } /* else might as well continue, and look for
1815                              another, or simply have the caller reopen it
1816                              again rather than trying to fix this handle */
1817                 } else /* write only file */
1818                         break; /* write only files are last so must be done */
1819         }
1820         spin_unlock(&tcon->open_file_lock);
1821         return NULL;
1822 }
1823
1824 struct cifsFileInfo *find_writable_file(struct cifsInodeInfo *cifs_inode,
1825                                         bool fsuid_only)
1826 {
1827         struct cifsFileInfo *open_file, *inv_file = NULL;
1828         struct cifs_sb_info *cifs_sb;
1829         struct cifs_tcon *tcon;
1830         bool any_available = false;
1831         int rc;
1832         unsigned int refind = 0;
1833
1834         /* Having a null inode here (because mapping->host was set to zero by
1835         the VFS or MM) should not happen but we had reports of on oops (due to
1836         it being zero) during stress testcases so we need to check for it */
1837
1838         if (cifs_inode == NULL) {
1839                 cifs_dbg(VFS, "Null inode passed to cifs_writeable_file\n");
1840                 dump_stack();
1841                 return NULL;
1842         }
1843
1844         cifs_sb = CIFS_SB(cifs_inode->vfs_inode.i_sb);
1845         tcon = cifs_sb_master_tcon(cifs_sb);
1846
1847         /* only filter by fsuid on multiuser mounts */
1848         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
1849                 fsuid_only = false;
1850
1851         spin_lock(&tcon->open_file_lock);
1852 refind_writable:
1853         if (refind > MAX_REOPEN_ATT) {
1854                 spin_unlock(&tcon->open_file_lock);
1855                 return NULL;
1856         }
1857         list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
1858                 if (!any_available && open_file->pid != current->tgid)
1859                         continue;
1860                 if (fsuid_only && !uid_eq(open_file->uid, current_fsuid()))
1861                         continue;
1862                 if (OPEN_FMODE(open_file->f_flags) & FMODE_WRITE) {
1863                         if (!open_file->invalidHandle) {
1864                                 /* found a good writable file */
1865                                 cifsFileInfo_get(open_file);
1866                                 spin_unlock(&tcon->open_file_lock);
1867                                 return open_file;
1868                         } else {
1869                                 if (!inv_file)
1870                                         inv_file = open_file;
1871                         }
1872                 }
1873         }
1874         /* couldn't find useable FH with same pid, try any available */
1875         if (!any_available) {
1876                 any_available = true;
1877                 goto refind_writable;
1878         }
1879
1880         if (inv_file) {
1881                 any_available = false;
1882                 cifsFileInfo_get(inv_file);
1883         }
1884
1885         spin_unlock(&tcon->open_file_lock);
1886
1887         if (inv_file) {
1888                 rc = cifs_reopen_file(inv_file, false);
1889                 if (!rc)
1890                         return inv_file;
1891                 else {
1892                         spin_lock(&tcon->open_file_lock);
1893                         list_move_tail(&inv_file->flist,
1894                                         &cifs_inode->openFileList);
1895                         spin_unlock(&tcon->open_file_lock);
1896                         cifsFileInfo_put(inv_file);
1897                         ++refind;
1898                         inv_file = NULL;
1899                         spin_lock(&tcon->open_file_lock);
1900                         goto refind_writable;
1901                 }
1902         }
1903
1904         return NULL;
1905 }
1906
1907 static int cifs_partialpagewrite(struct page *page, unsigned from, unsigned to)
1908 {
1909         struct address_space *mapping = page->mapping;
1910         loff_t offset = (loff_t)page->index << PAGE_SHIFT;
1911         char *write_data;
1912         int rc = -EFAULT;
1913         int bytes_written = 0;
1914         struct inode *inode;
1915         struct cifsFileInfo *open_file;
1916
1917         if (!mapping || !mapping->host)
1918                 return -EFAULT;
1919
1920         inode = page->mapping->host;
1921
1922         offset += (loff_t)from;
1923         write_data = kmap(page);
1924         write_data += from;
1925
1926         if ((to > PAGE_SIZE) || (from > to)) {
1927                 kunmap(page);
1928                 return -EIO;
1929         }
1930
1931         /* racing with truncate? */
1932         if (offset > mapping->host->i_size) {
1933                 kunmap(page);
1934                 return 0; /* don't care */
1935         }
1936
1937         /* check to make sure that we are not extending the file */
1938         if (mapping->host->i_size - offset < (loff_t)to)
1939                 to = (unsigned)(mapping->host->i_size - offset);
1940
1941         open_file = find_writable_file(CIFS_I(mapping->host), false);
1942         if (open_file) {
1943                 bytes_written = cifs_write(open_file, open_file->pid,
1944                                            write_data, to - from, &offset);
1945                 cifsFileInfo_put(open_file);
1946                 /* Does mm or vfs already set times? */
1947                 inode->i_atime = inode->i_mtime = current_time(inode);
1948                 if ((bytes_written > 0) && (offset))
1949                         rc = 0;
1950                 else if (bytes_written < 0)
1951                         rc = bytes_written;
1952         } else {
1953                 cifs_dbg(FYI, "No writeable filehandles for inode\n");
1954                 rc = -EIO;
1955         }
1956
1957         kunmap(page);
1958         return rc;
1959 }
1960
1961 static struct cifs_writedata *
1962 wdata_alloc_and_fillpages(pgoff_t tofind, struct address_space *mapping,
1963                           pgoff_t end, pgoff_t *index,
1964                           unsigned int *found_pages)
1965 {
1966         struct cifs_writedata *wdata;
1967
1968         wdata = cifs_writedata_alloc((unsigned int)tofind,
1969                                      cifs_writev_complete);
1970         if (!wdata)
1971                 return NULL;
1972
1973         *found_pages = find_get_pages_range_tag(mapping, index, end,
1974                                 PAGECACHE_TAG_DIRTY, tofind, wdata->pages);
1975         return wdata;
1976 }
1977
1978 static unsigned int
1979 wdata_prepare_pages(struct cifs_writedata *wdata, unsigned int found_pages,
1980                     struct address_space *mapping,
1981                     struct writeback_control *wbc,
1982                     pgoff_t end, pgoff_t *index, pgoff_t *next, bool *done)
1983 {
1984         unsigned int nr_pages = 0, i;
1985         struct page *page;
1986
1987         for (i = 0; i < found_pages; i++) {
1988                 page = wdata->pages[i];
1989                 /*
1990                  * At this point we hold neither the i_pages lock nor the
1991                  * page lock: the page may be truncated or invalidated
1992                  * (changing page->mapping to NULL), or even swizzled
1993                  * back from swapper_space to tmpfs file mapping
1994                  */
1995
1996                 if (nr_pages == 0)
1997                         lock_page(page);
1998                 else if (!trylock_page(page))
1999                         break;
2000
2001                 if (unlikely(page->mapping != mapping)) {
2002                         unlock_page(page);
2003                         break;
2004                 }
2005
2006                 if (!wbc->range_cyclic && page->index > end) {
2007                         *done = true;
2008                         unlock_page(page);
2009                         break;
2010                 }
2011
2012                 if (*next && (page->index != *next)) {
2013                         /* Not next consecutive page */
2014                         unlock_page(page);
2015                         break;
2016                 }
2017
2018                 if (wbc->sync_mode != WB_SYNC_NONE)
2019                         wait_on_page_writeback(page);
2020
2021                 if (PageWriteback(page) ||
2022                                 !clear_page_dirty_for_io(page)) {
2023                         unlock_page(page);
2024                         break;
2025                 }
2026
2027                 /*
2028                  * This actually clears the dirty bit in the radix tree.
2029                  * See cifs_writepage() for more commentary.
2030                  */
2031                 set_page_writeback(page);
2032                 if (page_offset(page) >= i_size_read(mapping->host)) {
2033                         *done = true;
2034                         unlock_page(page);
2035                         end_page_writeback(page);
2036                         break;
2037                 }
2038
2039                 wdata->pages[i] = page;
2040                 *next = page->index + 1;
2041                 ++nr_pages;
2042         }
2043
2044         /* reset index to refind any pages skipped */
2045         if (nr_pages == 0)
2046                 *index = wdata->pages[0]->index + 1;
2047
2048         /* put any pages we aren't going to use */
2049         for (i = nr_pages; i < found_pages; i++) {
2050                 put_page(wdata->pages[i]);
2051                 wdata->pages[i] = NULL;
2052         }
2053
2054         return nr_pages;
2055 }
2056
2057 static int
2058 wdata_send_pages(struct cifs_writedata *wdata, unsigned int nr_pages,
2059                  struct address_space *mapping, struct writeback_control *wbc)
2060 {
2061         int rc = 0;
2062         struct TCP_Server_Info *server;
2063         unsigned int i;
2064
2065         wdata->sync_mode = wbc->sync_mode;
2066         wdata->nr_pages = nr_pages;
2067         wdata->offset = page_offset(wdata->pages[0]);
2068         wdata->pagesz = PAGE_SIZE;
2069         wdata->tailsz = min(i_size_read(mapping->host) -
2070                         page_offset(wdata->pages[nr_pages - 1]),
2071                         (loff_t)PAGE_SIZE);
2072         wdata->bytes = ((nr_pages - 1) * PAGE_SIZE) + wdata->tailsz;
2073
2074         if (wdata->cfile != NULL)
2075                 cifsFileInfo_put(wdata->cfile);
2076         wdata->cfile = find_writable_file(CIFS_I(mapping->host), false);
2077         if (!wdata->cfile) {
2078                 cifs_dbg(VFS, "No writable handles for inode\n");
2079                 rc = -EBADF;
2080         } else {
2081                 wdata->pid = wdata->cfile->pid;
2082                 server = tlink_tcon(wdata->cfile->tlink)->ses->server;
2083                 rc = server->ops->async_writev(wdata, cifs_writedata_release);
2084         }
2085
2086         for (i = 0; i < nr_pages; ++i)
2087                 unlock_page(wdata->pages[i]);
2088
2089         return rc;
2090 }
2091
2092 static int cifs_writepages(struct address_space *mapping,
2093                            struct writeback_control *wbc)
2094 {
2095         struct cifs_sb_info *cifs_sb = CIFS_SB(mapping->host->i_sb);
2096         struct TCP_Server_Info *server;
2097         bool done = false, scanned = false, range_whole = false;
2098         pgoff_t end, index;
2099         struct cifs_writedata *wdata;
2100         int rc = 0;
2101
2102         /*
2103          * If wsize is smaller than the page cache size, default to writing
2104          * one page at a time via cifs_writepage
2105          */
2106         if (cifs_sb->wsize < PAGE_SIZE)
2107                 return generic_writepages(mapping, wbc);
2108
2109         if (wbc->range_cyclic) {
2110                 index = mapping->writeback_index; /* Start from prev offset */
2111                 end = -1;
2112         } else {
2113                 index = wbc->range_start >> PAGE_SHIFT;
2114                 end = wbc->range_end >> PAGE_SHIFT;
2115                 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
2116                         range_whole = true;
2117                 scanned = true;
2118         }
2119         server = cifs_sb_master_tcon(cifs_sb)->ses->server;
2120 retry:
2121         while (!done && index <= end) {
2122                 unsigned int i, nr_pages, found_pages, wsize, credits;
2123                 pgoff_t next = 0, tofind, saved_index = index;
2124
2125                 rc = server->ops->wait_mtu_credits(server, cifs_sb->wsize,
2126                                                    &wsize, &credits);
2127                 if (rc)
2128                         break;
2129
2130                 tofind = min((wsize / PAGE_SIZE) - 1, end - index) + 1;
2131
2132                 wdata = wdata_alloc_and_fillpages(tofind, mapping, end, &index,
2133                                                   &found_pages);
2134                 if (!wdata) {
2135                         rc = -ENOMEM;
2136                         add_credits_and_wake_if(server, credits, 0);
2137                         break;
2138                 }
2139
2140                 if (found_pages == 0) {
2141                         kref_put(&wdata->refcount, cifs_writedata_release);
2142                         add_credits_and_wake_if(server, credits, 0);
2143                         break;
2144                 }
2145
2146                 nr_pages = wdata_prepare_pages(wdata, found_pages, mapping, wbc,
2147                                                end, &index, &next, &done);
2148
2149                 /* nothing to write? */
2150                 if (nr_pages == 0) {
2151                         kref_put(&wdata->refcount, cifs_writedata_release);
2152                         add_credits_and_wake_if(server, credits, 0);
2153                         continue;
2154                 }
2155
2156                 wdata->credits = credits;
2157
2158                 rc = wdata_send_pages(wdata, nr_pages, mapping, wbc);
2159
2160                 /* send failure -- clean up the mess */
2161                 if (rc != 0) {
2162                         add_credits_and_wake_if(server, wdata->credits, 0);
2163                         for (i = 0; i < nr_pages; ++i) {
2164                                 if (rc == -EAGAIN)
2165                                         redirty_page_for_writepage(wbc,
2166                                                            wdata->pages[i]);
2167                                 else
2168                                         SetPageError(wdata->pages[i]);
2169                                 end_page_writeback(wdata->pages[i]);
2170                                 put_page(wdata->pages[i]);
2171                         }
2172                         if (rc != -EAGAIN)
2173                                 mapping_set_error(mapping, rc);
2174                 }
2175                 kref_put(&wdata->refcount, cifs_writedata_release);
2176
2177                 if (wbc->sync_mode == WB_SYNC_ALL && rc == -EAGAIN) {
2178                         index = saved_index;
2179                         continue;
2180                 }
2181
2182                 wbc->nr_to_write -= nr_pages;
2183                 if (wbc->nr_to_write <= 0)
2184                         done = true;
2185
2186                 index = next;
2187         }
2188
2189         if (!scanned && !done) {
2190                 /*
2191                  * We hit the last page and there is more work to be done: wrap
2192                  * back to the start of the file
2193                  */
2194                 scanned = true;
2195                 index = 0;
2196                 goto retry;
2197         }
2198
2199         if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
2200                 mapping->writeback_index = index;
2201
2202         return rc;
2203 }
2204
2205 static int
2206 cifs_writepage_locked(struct page *page, struct writeback_control *wbc)
2207 {
2208         int rc;
2209         unsigned int xid;
2210
2211         xid = get_xid();
2212 /* BB add check for wbc flags */
2213         get_page(page);
2214         if (!PageUptodate(page))
2215                 cifs_dbg(FYI, "ppw - page not up to date\n");
2216
2217         /*
2218          * Set the "writeback" flag, and clear "dirty" in the radix tree.
2219          *
2220          * A writepage() implementation always needs to do either this,
2221          * or re-dirty the page with "redirty_page_for_writepage()" in
2222          * the case of a failure.
2223          *
2224          * Just unlocking the page will cause the radix tree tag-bits
2225          * to fail to update with the state of the page correctly.
2226          */
2227         set_page_writeback(page);
2228 retry_write:
2229         rc = cifs_partialpagewrite(page, 0, PAGE_SIZE);
2230         if (rc == -EAGAIN) {
2231                 if (wbc->sync_mode == WB_SYNC_ALL)
2232                         goto retry_write;
2233                 redirty_page_for_writepage(wbc, page);
2234         } else if (rc != 0) {
2235                 SetPageError(page);
2236                 mapping_set_error(page->mapping, rc);
2237         } else {
2238                 SetPageUptodate(page);
2239         }
2240         end_page_writeback(page);
2241         put_page(page);
2242         free_xid(xid);
2243         return rc;
2244 }
2245
2246 static int cifs_writepage(struct page *page, struct writeback_control *wbc)
2247 {
2248         int rc = cifs_writepage_locked(page, wbc);
2249         unlock_page(page);
2250         return rc;
2251 }
2252
2253 static int cifs_write_end(struct file *file, struct address_space *mapping,
2254                         loff_t pos, unsigned len, unsigned copied,
2255                         struct page *page, void *fsdata)
2256 {
2257         int rc;
2258         struct inode *inode = mapping->host;
2259         struct cifsFileInfo *cfile = file->private_data;
2260         struct cifs_sb_info *cifs_sb = CIFS_SB(cfile->dentry->d_sb);
2261         __u32 pid;
2262
2263         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
2264                 pid = cfile->pid;
2265         else
2266                 pid = current->tgid;
2267
2268         cifs_dbg(FYI, "write_end for page %p from pos %lld with %d bytes\n",
2269                  page, pos, copied);
2270
2271         if (PageChecked(page)) {
2272                 if (copied == len)
2273                         SetPageUptodate(page);
2274                 ClearPageChecked(page);
2275         } else if (!PageUptodate(page) && copied == PAGE_SIZE)
2276                 SetPageUptodate(page);
2277
2278         if (!PageUptodate(page)) {
2279                 char *page_data;
2280                 unsigned offset = pos & (PAGE_SIZE - 1);
2281                 unsigned int xid;
2282
2283                 xid = get_xid();
2284                 /* this is probably better than directly calling
2285                    partialpage_write since in this function the file handle is
2286                    known which we might as well leverage */
2287                 /* BB check if anything else missing out of ppw
2288                    such as updating last write time */
2289                 page_data = kmap(page);
2290                 rc = cifs_write(cfile, pid, page_data + offset, copied, &pos);
2291                 /* if (rc < 0) should we set writebehind rc? */
2292                 kunmap(page);
2293
2294                 free_xid(xid);
2295         } else {
2296                 rc = copied;
2297                 pos += copied;
2298                 set_page_dirty(page);
2299         }
2300
2301         if (rc > 0) {
2302                 spin_lock(&inode->i_lock);
2303                 if (pos > inode->i_size)
2304                         i_size_write(inode, pos);
2305                 spin_unlock(&inode->i_lock);
2306         }
2307
2308         unlock_page(page);
2309         put_page(page);
2310
2311         return rc;
2312 }
2313
2314 int cifs_strict_fsync(struct file *file, loff_t start, loff_t end,
2315                       int datasync)
2316 {
2317         unsigned int xid;
2318         int rc = 0;
2319         struct cifs_tcon *tcon;
2320         struct TCP_Server_Info *server;
2321         struct cifsFileInfo *smbfile = file->private_data;
2322         struct inode *inode = file_inode(file);
2323         struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
2324
2325         rc = file_write_and_wait_range(file, start, end);
2326         if (rc)
2327                 return rc;
2328         inode_lock(inode);
2329
2330         xid = get_xid();
2331
2332         cifs_dbg(FYI, "Sync file - name: %pD datasync: 0x%x\n",
2333                  file, datasync);
2334
2335         if (!CIFS_CACHE_READ(CIFS_I(inode))) {
2336                 rc = cifs_zap_mapping(inode);
2337                 if (rc) {
2338                         cifs_dbg(FYI, "rc: %d during invalidate phase\n", rc);
2339                         rc = 0; /* don't care about it in fsync */
2340                 }
2341         }
2342
2343         tcon = tlink_tcon(smbfile->tlink);
2344         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC)) {
2345                 server = tcon->ses->server;
2346                 if (server->ops->flush)
2347                         rc = server->ops->flush(xid, tcon, &smbfile->fid);
2348                 else
2349                         rc = -ENOSYS;
2350         }
2351
2352         free_xid(xid);
2353         inode_unlock(inode);
2354         return rc;
2355 }
2356
2357 int cifs_fsync(struct file *file, loff_t start, loff_t end, int datasync)
2358 {
2359         unsigned int xid;
2360         int rc = 0;
2361         struct cifs_tcon *tcon;
2362         struct TCP_Server_Info *server;
2363         struct cifsFileInfo *smbfile = file->private_data;
2364         struct cifs_sb_info *cifs_sb = CIFS_FILE_SB(file);
2365         struct inode *inode = file->f_mapping->host;
2366
2367         rc = file_write_and_wait_range(file, start, end);
2368         if (rc)
2369                 return rc;
2370         inode_lock(inode);
2371
2372         xid = get_xid();
2373
2374         cifs_dbg(FYI, "Sync file - name: %pD datasync: 0x%x\n",
2375                  file, datasync);
2376
2377         tcon = tlink_tcon(smbfile->tlink);
2378         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC)) {
2379                 server = tcon->ses->server;
2380                 if (server->ops->flush)
2381                         rc = server->ops->flush(xid, tcon, &smbfile->fid);
2382                 else
2383                         rc = -ENOSYS;
2384         }
2385
2386         free_xid(xid);
2387         inode_unlock(inode);
2388         return rc;
2389 }
2390
2391 /*
2392  * As file closes, flush all cached write data for this inode checking
2393  * for write behind errors.
2394  */
2395 int cifs_flush(struct file *file, fl_owner_t id)
2396 {
2397         struct inode *inode = file_inode(file);
2398         int rc = 0;
2399
2400         if (file->f_mode & FMODE_WRITE)
2401                 rc = filemap_write_and_wait(inode->i_mapping);
2402
2403         cifs_dbg(FYI, "Flush inode %p file %p rc %d\n", inode, file, rc);
2404
2405         return rc;
2406 }
2407
2408 static int
2409 cifs_write_allocate_pages(struct page **pages, unsigned long num_pages)
2410 {
2411         int rc = 0;
2412         unsigned long i;
2413
2414         for (i = 0; i < num_pages; i++) {
2415                 pages[i] = alloc_page(GFP_KERNEL|__GFP_HIGHMEM);
2416                 if (!pages[i]) {
2417                         /*
2418                          * save number of pages we have already allocated and
2419                          * return with ENOMEM error
2420                          */
2421                         num_pages = i;
2422                         rc = -ENOMEM;
2423                         break;
2424                 }
2425         }
2426
2427         if (rc) {
2428                 for (i = 0; i < num_pages; i++)
2429                         put_page(pages[i]);
2430         }
2431         return rc;
2432 }
2433
2434 static inline
2435 size_t get_numpages(const size_t wsize, const size_t len, size_t *cur_len)
2436 {
2437         size_t num_pages;
2438         size_t clen;
2439
2440         clen = min_t(const size_t, len, wsize);
2441         num_pages = DIV_ROUND_UP(clen, PAGE_SIZE);
2442
2443         if (cur_len)
2444                 *cur_len = clen;
2445
2446         return num_pages;
2447 }
2448
2449 static void
2450 cifs_uncached_writedata_release(struct kref *refcount)
2451 {
2452         int i;
2453         struct cifs_writedata *wdata = container_of(refcount,
2454                                         struct cifs_writedata, refcount);
2455
2456         kref_put(&wdata->ctx->refcount, cifs_aio_ctx_release);
2457         for (i = 0; i < wdata->nr_pages; i++)
2458                 put_page(wdata->pages[i]);
2459         cifs_writedata_release(refcount);
2460 }
2461
2462 static void collect_uncached_write_data(struct cifs_aio_ctx *ctx);
2463
2464 static void
2465 cifs_uncached_writev_complete(struct work_struct *work)
2466 {
2467         struct cifs_writedata *wdata = container_of(work,
2468                                         struct cifs_writedata, work);
2469         struct inode *inode = d_inode(wdata->cfile->dentry);
2470         struct cifsInodeInfo *cifsi = CIFS_I(inode);
2471
2472         spin_lock(&inode->i_lock);
2473         cifs_update_eof(cifsi, wdata->offset, wdata->bytes);
2474         if (cifsi->server_eof > inode->i_size)
2475                 i_size_write(inode, cifsi->server_eof);
2476         spin_unlock(&inode->i_lock);
2477
2478         complete(&wdata->done);
2479         collect_uncached_write_data(wdata->ctx);
2480         /* the below call can possibly free the last ref to aio ctx */
2481         kref_put(&wdata->refcount, cifs_uncached_writedata_release);
2482 }
2483
2484 static int
2485 wdata_fill_from_iovec(struct cifs_writedata *wdata, struct iov_iter *from,
2486                       size_t *len, unsigned long *num_pages)
2487 {
2488         size_t save_len, copied, bytes, cur_len = *len;
2489         unsigned long i, nr_pages = *num_pages;
2490
2491         save_len = cur_len;
2492         for (i = 0; i < nr_pages; i++) {
2493                 bytes = min_t(const size_t, cur_len, PAGE_SIZE);
2494                 copied = copy_page_from_iter(wdata->pages[i], 0, bytes, from);
2495                 cur_len -= copied;
2496                 /*
2497                  * If we didn't copy as much as we expected, then that
2498                  * may mean we trod into an unmapped area. Stop copying
2499                  * at that point. On the next pass through the big
2500                  * loop, we'll likely end up getting a zero-length
2501                  * write and bailing out of it.
2502                  */
2503                 if (copied < bytes)
2504                         break;
2505         }
2506         cur_len = save_len - cur_len;
2507         *len = cur_len;
2508
2509         /*
2510          * If we have no data to send, then that probably means that
2511          * the copy above failed altogether. That's most likely because
2512          * the address in the iovec was bogus. Return -EFAULT and let
2513          * the caller free anything we allocated and bail out.
2514          */
2515         if (!cur_len)
2516                 return -EFAULT;
2517
2518         /*
2519          * i + 1 now represents the number of pages we actually used in
2520          * the copy phase above.
2521          */
2522         *num_pages = i + 1;
2523         return 0;
2524 }
2525
2526 static int
2527 cifs_write_from_iter(loff_t offset, size_t len, struct iov_iter *from,
2528                      struct cifsFileInfo *open_file,
2529                      struct cifs_sb_info *cifs_sb, struct list_head *wdata_list,
2530                      struct cifs_aio_ctx *ctx)
2531 {
2532         int rc = 0;
2533         size_t cur_len;
2534         unsigned long nr_pages, num_pages, i;
2535         struct cifs_writedata *wdata;
2536         struct iov_iter saved_from = *from;
2537         loff_t saved_offset = offset;
2538         pid_t pid;
2539         struct TCP_Server_Info *server;
2540
2541         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
2542                 pid = open_file->pid;
2543         else
2544                 pid = current->tgid;
2545
2546         server = tlink_tcon(open_file->tlink)->ses->server;
2547
2548         do {
2549                 unsigned int wsize, credits;
2550
2551                 rc = server->ops->wait_mtu_credits(server, cifs_sb->wsize,
2552                                                    &wsize, &credits);
2553                 if (rc)
2554                         break;
2555
2556                 nr_pages = get_numpages(wsize, len, &cur_len);
2557                 wdata = cifs_writedata_alloc(nr_pages,
2558                                              cifs_uncached_writev_complete);
2559                 if (!wdata) {
2560                         rc = -ENOMEM;
2561                         add_credits_and_wake_if(server, credits, 0);
2562                         break;
2563                 }
2564
2565                 rc = cifs_write_allocate_pages(wdata->pages, nr_pages);
2566                 if (rc) {
2567                         kfree(wdata);
2568                         add_credits_and_wake_if(server, credits, 0);
2569                         break;
2570                 }
2571
2572                 num_pages = nr_pages;
2573                 rc = wdata_fill_from_iovec(wdata, from, &cur_len, &num_pages);
2574                 if (rc) {
2575                         for (i = 0; i < nr_pages; i++)
2576                                 put_page(wdata->pages[i]);
2577                         kfree(wdata);
2578                         add_credits_and_wake_if(server, credits, 0);
2579                         break;
2580                 }
2581
2582                 /*
2583                  * Bring nr_pages down to the number of pages we actually used,
2584                  * and free any pages that we didn't use.
2585                  */
2586                 for ( ; nr_pages > num_pages; nr_pages--)
2587                         put_page(wdata->pages[nr_pages - 1]);
2588
2589                 wdata->sync_mode = WB_SYNC_ALL;
2590                 wdata->nr_pages = nr_pages;
2591                 wdata->offset = (__u64)offset;
2592                 wdata->cfile = cifsFileInfo_get(open_file);
2593                 wdata->pid = pid;
2594                 wdata->bytes = cur_len;
2595                 wdata->pagesz = PAGE_SIZE;
2596                 wdata->tailsz = cur_len - ((nr_pages - 1) * PAGE_SIZE);
2597                 wdata->credits = credits;
2598                 wdata->ctx = ctx;
2599                 kref_get(&ctx->refcount);
2600
2601                 if (!wdata->cfile->invalidHandle ||
2602                     !(rc = cifs_reopen_file(wdata->cfile, false)))
2603                         rc = server->ops->async_writev(wdata,
2604                                         cifs_uncached_writedata_release);
2605                 if (rc) {
2606                         add_credits_and_wake_if(server, wdata->credits, 0);
2607                         kref_put(&wdata->refcount,
2608                                  cifs_uncached_writedata_release);
2609                         if (rc == -EAGAIN) {
2610                                 *from = saved_from;
2611                                 iov_iter_advance(from, offset - saved_offset);
2612                                 continue;
2613                         }
2614                         break;
2615                 }
2616
2617                 list_add_tail(&wdata->list, wdata_list);
2618                 offset += cur_len;
2619                 len -= cur_len;
2620         } while (len > 0);
2621
2622         return rc;
2623 }
2624
2625 static void collect_uncached_write_data(struct cifs_aio_ctx *ctx)
2626 {
2627         struct cifs_writedata *wdata, *tmp;
2628         struct cifs_tcon *tcon;
2629         struct cifs_sb_info *cifs_sb;
2630         struct dentry *dentry = ctx->cfile->dentry;
2631         unsigned int i;
2632         int rc;
2633
2634         tcon = tlink_tcon(ctx->cfile->tlink);
2635         cifs_sb = CIFS_SB(dentry->d_sb);
2636
2637         mutex_lock(&ctx->aio_mutex);
2638
2639         if (list_empty(&ctx->list)) {
2640                 mutex_unlock(&ctx->aio_mutex);
2641                 return;
2642         }
2643
2644         rc = ctx->rc;
2645         /*
2646          * Wait for and collect replies for any successful sends in order of
2647          * increasing offset. Once an error is hit, then return without waiting
2648          * for any more replies.
2649          */
2650 restart_loop:
2651         list_for_each_entry_safe(wdata, tmp, &ctx->list, list) {
2652                 if (!rc) {
2653                         if (!try_wait_for_completion(&wdata->done)) {
2654                                 mutex_unlock(&ctx->aio_mutex);
2655                                 return;
2656                         }
2657
2658                         if (wdata->result)
2659                                 rc = wdata->result;
2660                         else
2661                                 ctx->total_len += wdata->bytes;
2662
2663                         /* resend call if it's a retryable error */
2664                         if (rc == -EAGAIN) {
2665                                 struct list_head tmp_list;
2666                                 struct iov_iter tmp_from = ctx->iter;
2667
2668                                 INIT_LIST_HEAD(&tmp_list);
2669                                 list_del_init(&wdata->list);
2670
2671                                 iov_iter_advance(&tmp_from,
2672                                                  wdata->offset - ctx->pos);
2673
2674                                 rc = cifs_write_from_iter(wdata->offset,
2675                                                 wdata->bytes, &tmp_from,
2676                                                 ctx->cfile, cifs_sb, &tmp_list,
2677                                                 ctx);
2678
2679                                 list_splice(&tmp_list, &ctx->list);
2680
2681                                 kref_put(&wdata->refcount,
2682                                          cifs_uncached_writedata_release);
2683                                 goto restart_loop;
2684                         }
2685                 }
2686                 list_del_init(&wdata->list);
2687                 kref_put(&wdata->refcount, cifs_uncached_writedata_release);
2688         }
2689
2690         for (i = 0; i < ctx->npages; i++)
2691                 put_page(ctx->bv[i].bv_page);
2692
2693         cifs_stats_bytes_written(tcon, ctx->total_len);
2694         set_bit(CIFS_INO_INVALID_MAPPING, &CIFS_I(dentry->d_inode)->flags);
2695
2696         ctx->rc = (rc == 0) ? ctx->total_len : rc;
2697
2698         mutex_unlock(&ctx->aio_mutex);
2699
2700         if (ctx->iocb && ctx->iocb->ki_complete)
2701                 ctx->iocb->ki_complete(ctx->iocb, ctx->rc, 0);
2702         else
2703                 complete(&ctx->done);
2704 }
2705
2706 ssize_t cifs_user_writev(struct kiocb *iocb, struct iov_iter *from)
2707 {
2708         struct file *file = iocb->ki_filp;
2709         ssize_t total_written = 0;
2710         struct cifsFileInfo *cfile;
2711         struct cifs_tcon *tcon;
2712         struct cifs_sb_info *cifs_sb;
2713         struct cifs_aio_ctx *ctx;
2714         struct iov_iter saved_from = *from;
2715         int rc;
2716
2717         /*
2718          * BB - optimize the way when signing is disabled. We can drop this
2719          * extra memory-to-memory copying and use iovec buffers for constructing
2720          * write request.
2721          */
2722
2723         rc = generic_write_checks(iocb, from);
2724         if (rc <= 0)
2725                 return rc;
2726
2727         cifs_sb = CIFS_FILE_SB(file);
2728         cfile = file->private_data;
2729         tcon = tlink_tcon(cfile->tlink);
2730
2731         if (!tcon->ses->server->ops->async_writev)
2732                 return -ENOSYS;
2733
2734         ctx = cifs_aio_ctx_alloc();
2735         if (!ctx)
2736                 return -ENOMEM;
2737
2738         ctx->cfile = cifsFileInfo_get(cfile);
2739
2740         if (!is_sync_kiocb(iocb))
2741                 ctx->iocb = iocb;
2742
2743         ctx->pos = iocb->ki_pos;
2744
2745         rc = setup_aio_ctx_iter(ctx, from, WRITE);
2746         if (rc) {
2747                 kref_put(&ctx->refcount, cifs_aio_ctx_release);
2748                 return rc;
2749         }
2750
2751         /* grab a lock here due to read response handlers can access ctx */
2752         mutex_lock(&ctx->aio_mutex);
2753
2754         rc = cifs_write_from_iter(iocb->ki_pos, ctx->len, &saved_from,
2755                                   cfile, cifs_sb, &ctx->list, ctx);
2756
2757         /*
2758          * If at least one write was successfully sent, then discard any rc
2759          * value from the later writes. If the other write succeeds, then
2760          * we'll end up returning whatever was written. If it fails, then
2761          * we'll get a new rc value from that.
2762          */
2763         if (!list_empty(&ctx->list))
2764                 rc = 0;
2765
2766         mutex_unlock(&ctx->aio_mutex);
2767
2768         if (rc) {
2769                 kref_put(&ctx->refcount, cifs_aio_ctx_release);
2770                 return rc;
2771         }
2772
2773         if (!is_sync_kiocb(iocb)) {
2774                 kref_put(&ctx->refcount, cifs_aio_ctx_release);
2775                 return -EIOCBQUEUED;
2776         }
2777
2778         rc = wait_for_completion_killable(&ctx->done);
2779         if (rc) {
2780                 mutex_lock(&ctx->aio_mutex);
2781                 ctx->rc = rc = -EINTR;
2782                 total_written = ctx->total_len;
2783                 mutex_unlock(&ctx->aio_mutex);
2784         } else {
2785                 rc = ctx->rc;
2786                 total_written = ctx->total_len;
2787         }
2788
2789         kref_put(&ctx->refcount, cifs_aio_ctx_release);
2790
2791         if (unlikely(!total_written))
2792                 return rc;
2793
2794         iocb->ki_pos += total_written;
2795         return total_written;
2796 }
2797
2798 static ssize_t
2799 cifs_writev(struct kiocb *iocb, struct iov_iter *from)
2800 {
2801         struct file *file = iocb->ki_filp;
2802         struct cifsFileInfo *cfile = (struct cifsFileInfo *)file->private_data;
2803         struct inode *inode = file->f_mapping->host;
2804         struct cifsInodeInfo *cinode = CIFS_I(inode);
2805         struct TCP_Server_Info *server = tlink_tcon(cfile->tlink)->ses->server;
2806         ssize_t rc;
2807
2808         inode_lock(inode);
2809         /*
2810          * We need to hold the sem to be sure nobody modifies lock list
2811          * with a brlock that prevents writing.
2812          */
2813         down_read(&cinode->lock_sem);
2814
2815         rc = generic_write_checks(iocb, from);
2816         if (rc <= 0)
2817                 goto out;
2818
2819         if (!cifs_find_lock_conflict(cfile, iocb->ki_pos, iov_iter_count(from),
2820                                      server->vals->exclusive_lock_type, NULL,
2821                                      CIFS_WRITE_OP))
2822                 rc = __generic_file_write_iter(iocb, from);
2823         else
2824                 rc = -EACCES;
2825 out:
2826         up_read(&cinode->lock_sem);
2827         inode_unlock(inode);
2828
2829         if (rc > 0)
2830                 rc = generic_write_sync(iocb, rc);
2831         return rc;
2832 }
2833
2834 ssize_t
2835 cifs_strict_writev(struct kiocb *iocb, struct iov_iter *from)
2836 {
2837         struct inode *inode = file_inode(iocb->ki_filp);
2838         struct cifsInodeInfo *cinode = CIFS_I(inode);
2839         struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
2840         struct cifsFileInfo *cfile = (struct cifsFileInfo *)
2841                                                 iocb->ki_filp->private_data;
2842         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
2843         ssize_t written;
2844
2845         written = cifs_get_writer(cinode);
2846         if (written)
2847                 return written;
2848
2849         if (CIFS_CACHE_WRITE(cinode)) {
2850                 if (cap_unix(tcon->ses) &&
2851                 (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability))
2852                   && ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0)) {
2853                         written = generic_file_write_iter(iocb, from);
2854                         goto out;
2855                 }
2856                 written = cifs_writev(iocb, from);
2857                 goto out;
2858         }
2859         /*
2860          * For non-oplocked files in strict cache mode we need to write the data
2861          * to the server exactly from the pos to pos+len-1 rather than flush all
2862          * affected pages because it may cause a error with mandatory locks on
2863          * these pages but not on the region from pos to ppos+len-1.
2864          */
2865         written = cifs_user_writev(iocb, from);
2866         if (written > 0 && CIFS_CACHE_READ(cinode)) {
2867                 /*
2868                  * Windows 7 server can delay breaking level2 oplock if a write
2869                  * request comes - break it on the client to prevent reading
2870                  * an old data.
2871                  */
2872                 cifs_zap_mapping(inode);
2873                 cifs_dbg(FYI, "Set no oplock for inode=%p after a write operation\n",
2874                          inode);
2875                 cinode->oplock = 0;
2876         }
2877 out:
2878         cifs_put_writer(cinode);
2879         return written;
2880 }
2881
2882 static struct cifs_readdata *
2883 cifs_readdata_alloc(unsigned int nr_pages, work_func_t complete)
2884 {
2885         struct cifs_readdata *rdata;
2886
2887         rdata = kzalloc(sizeof(*rdata) + (sizeof(struct page *) * nr_pages),
2888                         GFP_KERNEL);
2889         if (rdata != NULL) {
2890                 kref_init(&rdata->refcount);
2891                 INIT_LIST_HEAD(&rdata->list);
2892                 init_completion(&rdata->done);
2893                 INIT_WORK(&rdata->work, complete);
2894         }
2895
2896         return rdata;
2897 }
2898
2899 void
2900 cifs_readdata_release(struct kref *refcount)
2901 {
2902         struct cifs_readdata *rdata = container_of(refcount,
2903                                         struct cifs_readdata, refcount);
2904 #ifdef CONFIG_CIFS_SMB_DIRECT
2905         if (rdata->mr) {
2906                 smbd_deregister_mr(rdata->mr);
2907                 rdata->mr = NULL;
2908         }
2909 #endif
2910         if (rdata->cfile)
2911                 cifsFileInfo_put(rdata->cfile);
2912
2913         kfree(rdata);
2914 }
2915
2916 static int
2917 cifs_read_allocate_pages(struct cifs_readdata *rdata, unsigned int nr_pages)
2918 {
2919         int rc = 0;
2920         struct page *page;
2921         unsigned int i;
2922
2923         for (i = 0; i < nr_pages; i++) {
2924                 page = alloc_page(GFP_KERNEL|__GFP_HIGHMEM);
2925                 if (!page) {
2926                         rc = -ENOMEM;
2927                         break;
2928                 }
2929                 rdata->pages[i] = page;
2930         }
2931
2932         if (rc) {
2933                 for (i = 0; i < nr_pages; i++) {
2934                         put_page(rdata->pages[i]);
2935                         rdata->pages[i] = NULL;
2936                 }
2937         }
2938         return rc;
2939 }
2940
2941 static void
2942 cifs_uncached_readdata_release(struct kref *refcount)
2943 {
2944         struct cifs_readdata *rdata = container_of(refcount,
2945                                         struct cifs_readdata, refcount);
2946         unsigned int i;
2947
2948         kref_put(&rdata->ctx->refcount, cifs_aio_ctx_release);
2949         for (i = 0; i < rdata->nr_pages; i++) {
2950                 put_page(rdata->pages[i]);
2951                 rdata->pages[i] = NULL;
2952         }
2953         cifs_readdata_release(refcount);
2954 }
2955
2956 /**
2957  * cifs_readdata_to_iov - copy data from pages in response to an iovec
2958  * @rdata:      the readdata response with list of pages holding data
2959  * @iter:       destination for our data
2960  *
2961  * This function copies data from a list of pages in a readdata response into
2962  * an array of iovecs. It will first calculate where the data should go
2963  * based on the info in the readdata and then copy the data into that spot.
2964  */
2965 static int
2966 cifs_readdata_to_iov(struct cifs_readdata *rdata, struct iov_iter *iter)
2967 {
2968         size_t remaining = rdata->got_bytes;
2969         unsigned int i;
2970
2971         for (i = 0; i < rdata->nr_pages; i++) {
2972                 struct page *page = rdata->pages[i];
2973                 size_t copy = min_t(size_t, remaining, PAGE_SIZE);
2974                 size_t written;
2975
2976                 if (unlikely(iter->type & ITER_PIPE)) {
2977                         void *addr = kmap_atomic(page);
2978
2979                         written = copy_to_iter(addr, copy, iter);
2980                         kunmap_atomic(addr);
2981                 } else
2982                         written = copy_page_to_iter(page, 0, copy, iter);
2983                 remaining -= written;
2984                 if (written < copy && iov_iter_count(iter) > 0)
2985                         break;
2986         }
2987         return remaining ? -EFAULT : 0;
2988 }
2989
2990 static void collect_uncached_read_data(struct cifs_aio_ctx *ctx);
2991
2992 static void
2993 cifs_uncached_readv_complete(struct work_struct *work)
2994 {
2995         struct cifs_readdata *rdata = container_of(work,
2996                                                 struct cifs_readdata, work);
2997
2998         complete(&rdata->done);
2999         collect_uncached_read_data(rdata->ctx);
3000         /* the below call can possibly free the last ref to aio ctx */
3001         kref_put(&rdata->refcount, cifs_uncached_readdata_release);
3002 }
3003
3004 static int
3005 uncached_fill_pages(struct TCP_Server_Info *server,
3006                     struct cifs_readdata *rdata, struct iov_iter *iter,
3007                     unsigned int len)
3008 {
3009         int result = 0;
3010         unsigned int i;
3011         unsigned int nr_pages = rdata->nr_pages;
3012
3013         rdata->got_bytes = 0;
3014         rdata->tailsz = PAGE_SIZE;
3015         for (i = 0; i < nr_pages; i++) {
3016                 struct page *page = rdata->pages[i];
3017                 size_t n;
3018
3019                 if (len <= 0) {
3020                         /* no need to hold page hostage */
3021                         rdata->pages[i] = NULL;
3022                         rdata->nr_pages--;
3023                         put_page(page);
3024                         continue;
3025                 }
3026                 n = len;
3027                 if (len >= PAGE_SIZE) {
3028                         /* enough data to fill the page */
3029                         n = PAGE_SIZE;
3030                         len -= n;
3031                 } else {
3032                         zero_user(page, len, PAGE_SIZE - len);
3033                         rdata->tailsz = len;
3034                         len = 0;
3035                 }
3036                 if (iter)
3037                         result = copy_page_from_iter(page, 0, n, iter);
3038 #ifdef CONFIG_CIFS_SMB_DIRECT
3039                 else if (rdata->mr)
3040                         result = n;
3041 #endif
3042                 else
3043                         result = cifs_read_page_from_socket(server, page, n);
3044                 if (result < 0)
3045                         break;
3046
3047                 rdata->got_bytes += result;
3048         }
3049
3050         return rdata->got_bytes > 0 && result != -ECONNABORTED ?
3051                                                 rdata->got_bytes : result;
3052 }
3053
3054 static int
3055 cifs_uncached_read_into_pages(struct TCP_Server_Info *server,
3056                               struct cifs_readdata *rdata, unsigned int len)
3057 {
3058         return uncached_fill_pages(server, rdata, NULL, len);
3059 }
3060
3061 static int
3062 cifs_uncached_copy_into_pages(struct TCP_Server_Info *server,
3063                               struct cifs_readdata *rdata,
3064                               struct iov_iter *iter)
3065 {
3066         return uncached_fill_pages(server, rdata, iter, iter->count);
3067 }
3068
3069 static int
3070 cifs_send_async_read(loff_t offset, size_t len, struct cifsFileInfo *open_file,
3071                      struct cifs_sb_info *cifs_sb, struct list_head *rdata_list,
3072                      struct cifs_aio_ctx *ctx)
3073 {
3074         struct cifs_readdata *rdata;
3075         unsigned int npages, rsize, credits;
3076         size_t cur_len;
3077         int rc;
3078         pid_t pid;
3079         struct TCP_Server_Info *server;
3080
3081         server = tlink_tcon(open_file->tlink)->ses->server;
3082
3083         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
3084                 pid = open_file->pid;
3085         else
3086                 pid = current->tgid;
3087
3088         do {
3089                 rc = server->ops->wait_mtu_credits(server, cifs_sb->rsize,
3090                                                    &rsize, &credits);
3091                 if (rc)
3092                         break;
3093
3094                 cur_len = min_t(const size_t, len, rsize);
3095                 npages = DIV_ROUND_UP(cur_len, PAGE_SIZE);
3096
3097                 /* allocate a readdata struct */
3098                 rdata = cifs_readdata_alloc(npages,
3099                                             cifs_uncached_readv_complete);
3100                 if (!rdata) {
3101                         add_credits_and_wake_if(server, credits, 0);
3102                         rc = -ENOMEM;
3103                         break;
3104                 }
3105
3106                 rc = cifs_read_allocate_pages(rdata, npages);
3107                 if (rc)
3108                         goto error;
3109
3110                 rdata->cfile = cifsFileInfo_get(open_file);
3111                 rdata->nr_pages = npages;
3112                 rdata->offset = offset;
3113                 rdata->bytes = cur_len;
3114                 rdata->pid = pid;
3115                 rdata->pagesz = PAGE_SIZE;
3116                 rdata->read_into_pages = cifs_uncached_read_into_pages;
3117                 rdata->copy_into_pages = cifs_uncached_copy_into_pages;
3118                 rdata->credits = credits;
3119                 rdata->ctx = ctx;
3120                 kref_get(&ctx->refcount);
3121
3122                 if (!rdata->cfile->invalidHandle ||
3123                     !(rc = cifs_reopen_file(rdata->cfile, true)))
3124                         rc = server->ops->async_readv(rdata);
3125 error:
3126                 if (rc) {
3127                         add_credits_and_wake_if(server, rdata->credits, 0);
3128                         kref_put(&rdata->refcount,
3129                                  cifs_uncached_readdata_release);
3130                         if (rc == -EAGAIN)
3131                                 continue;
3132                         break;
3133                 }
3134
3135                 list_add_tail(&rdata->list, rdata_list);
3136                 offset += cur_len;
3137                 len -= cur_len;
3138         } while (len > 0);
3139
3140         return rc;
3141 }
3142
3143 static void
3144 collect_uncached_read_data(struct cifs_aio_ctx *ctx)
3145 {
3146         struct cifs_readdata *rdata, *tmp;
3147         struct iov_iter *to = &ctx->iter;
3148         struct cifs_sb_info *cifs_sb;
3149         struct cifs_tcon *tcon;
3150         unsigned int i;
3151         int rc;
3152
3153         tcon = tlink_tcon(ctx->cfile->tlink);
3154         cifs_sb = CIFS_SB(ctx->cfile->dentry->d_sb);
3155
3156         mutex_lock(&ctx->aio_mutex);
3157
3158         if (list_empty(&ctx->list)) {
3159                 mutex_unlock(&ctx->aio_mutex);
3160                 return;
3161         }
3162
3163         rc = ctx->rc;
3164         /* the loop below should proceed in the order of increasing offsets */
3165 again:
3166         list_for_each_entry_safe(rdata, tmp, &ctx->list, list) {
3167                 if (!rc) {
3168                         if (!try_wait_for_completion(&rdata->done)) {
3169                                 mutex_unlock(&ctx->aio_mutex);
3170                                 return;
3171                         }
3172
3173                         if (rdata->result == -EAGAIN) {
3174                                 /* resend call if it's a retryable error */
3175                                 struct list_head tmp_list;
3176                                 unsigned int got_bytes = rdata->got_bytes;
3177
3178                                 list_del_init(&rdata->list);
3179                                 INIT_LIST_HEAD(&tmp_list);
3180
3181                                 /*
3182                                  * Got a part of data and then reconnect has
3183                                  * happened -- fill the buffer and continue
3184                                  * reading.
3185                                  */
3186                                 if (got_bytes && got_bytes < rdata->bytes) {
3187                                         rc = cifs_readdata_to_iov(rdata, to);
3188                                         if (rc) {
3189                                                 kref_put(&rdata->refcount,
3190                                                 cifs_uncached_readdata_release);
3191                                                 continue;
3192                                         }
3193                                 }
3194
3195                                 rc = cifs_send_async_read(
3196                                                 rdata->offset + got_bytes,
3197                                                 rdata->bytes - got_bytes,
3198                                                 rdata->cfile, cifs_sb,
3199                                                 &tmp_list, ctx);
3200
3201                                 list_splice(&tmp_list, &ctx->list);
3202
3203                                 kref_put(&rdata->refcount,
3204                                          cifs_uncached_readdata_release);
3205                                 goto again;
3206                         } else if (rdata->result)
3207                                 rc = rdata->result;
3208                         else
3209                                 rc = cifs_readdata_to_iov(rdata, to);
3210
3211                         /* if there was a short read -- discard anything left */
3212                         if (rdata->got_bytes && rdata->got_bytes < rdata->bytes)
3213                                 rc = -ENODATA;
3214                 }
3215                 list_del_init(&rdata->list);
3216                 kref_put(&rdata->refcount, cifs_uncached_readdata_release);
3217         }
3218
3219         for (i = 0; i < ctx->npages; i++) {
3220                 if (ctx->should_dirty)
3221                         set_page_dirty(ctx->bv[i].bv_page);
3222                 put_page(ctx->bv[i].bv_page);
3223         }
3224
3225         ctx->total_len = ctx->len - iov_iter_count(to);
3226
3227         cifs_stats_bytes_read(tcon, ctx->total_len);
3228
3229         /* mask nodata case */
3230         if (rc == -ENODATA)
3231                 rc = 0;
3232
3233         ctx->rc = (rc == 0) ? ctx->total_len : rc;
3234
3235         mutex_unlock(&ctx->aio_mutex);
3236
3237         if (ctx->iocb && ctx->iocb->ki_complete)
3238                 ctx->iocb->ki_complete(ctx->iocb, ctx->rc, 0);
3239         else
3240                 complete(&ctx->done);
3241 }
3242
3243 ssize_t cifs_user_readv(struct kiocb *iocb, struct iov_iter *to)
3244 {
3245         struct file *file = iocb->ki_filp;
3246         ssize_t rc;
3247         size_t len;
3248         ssize_t total_read = 0;
3249         loff_t offset = iocb->ki_pos;
3250         struct cifs_sb_info *cifs_sb;
3251         struct cifs_tcon *tcon;
3252         struct cifsFileInfo *cfile;
3253         struct cifs_aio_ctx *ctx;
3254
3255         len = iov_iter_count(to);
3256         if (!len)
3257                 return 0;
3258
3259         cifs_sb = CIFS_FILE_SB(file);
3260         cfile = file->private_data;
3261         tcon = tlink_tcon(cfile->tlink);
3262
3263         if (!tcon->ses->server->ops->async_readv)
3264                 return -ENOSYS;
3265
3266         if ((file->f_flags & O_ACCMODE) == O_WRONLY)
3267                 cifs_dbg(FYI, "attempting read on write only file instance\n");
3268
3269         ctx = cifs_aio_ctx_alloc();
3270         if (!ctx)
3271                 return -ENOMEM;
3272
3273         ctx->cfile = cifsFileInfo_get(cfile);
3274
3275         if (!is_sync_kiocb(iocb))
3276                 ctx->iocb = iocb;
3277
3278         if (to->type == ITER_IOVEC)
3279                 ctx->should_dirty = true;
3280
3281         rc = setup_aio_ctx_iter(ctx, to, READ);
3282         if (rc) {
3283                 kref_put(&ctx->refcount, cifs_aio_ctx_release);
3284                 return rc;
3285         }
3286
3287         len = ctx->len;
3288
3289         /* grab a lock here due to read response handlers can access ctx */
3290         mutex_lock(&ctx->aio_mutex);
3291
3292         rc = cifs_send_async_read(offset, len, cfile, cifs_sb, &ctx->list, ctx);
3293
3294         /* if at least one read request send succeeded, then reset rc */
3295         if (!list_empty(&ctx->list))
3296                 rc = 0;
3297
3298         mutex_unlock(&ctx->aio_mutex);
3299
3300         if (rc) {
3301                 kref_put(&ctx->refcount, cifs_aio_ctx_release);
3302                 return rc;
3303         }
3304
3305         if (!is_sync_kiocb(iocb)) {
3306                 kref_put(&ctx->refcount, cifs_aio_ctx_release);
3307                 return -EIOCBQUEUED;
3308         }
3309
3310         rc = wait_for_completion_killable(&ctx->done);
3311         if (rc) {
3312                 mutex_lock(&ctx->aio_mutex);
3313                 ctx->rc = rc = -EINTR;
3314                 total_read = ctx->total_len;
3315                 mutex_unlock(&ctx->aio_mutex);
3316         } else {
3317                 rc = ctx->rc;
3318                 total_read = ctx->total_len;
3319         }
3320
3321         kref_put(&ctx->refcount, cifs_aio_ctx_release);
3322
3323         if (total_read) {
3324                 iocb->ki_pos += total_read;
3325                 return total_read;
3326         }
3327         return rc;
3328 }
3329
3330 ssize_t
3331 cifs_strict_readv(struct kiocb *iocb, struct iov_iter *to)
3332 {
3333         struct inode *inode = file_inode(iocb->ki_filp);
3334         struct cifsInodeInfo *cinode = CIFS_I(inode);
3335         struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
3336         struct cifsFileInfo *cfile = (struct cifsFileInfo *)
3337                                                 iocb->ki_filp->private_data;
3338         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
3339         int rc = -EACCES;
3340
3341         /*
3342          * In strict cache mode we need to read from the server all the time
3343          * if we don't have level II oplock because the server can delay mtime
3344          * change - so we can't make a decision about inode invalidating.
3345          * And we can also fail with pagereading if there are mandatory locks
3346          * on pages affected by this read but not on the region from pos to
3347          * pos+len-1.
3348          */
3349         if (!CIFS_CACHE_READ(cinode))
3350                 return cifs_user_readv(iocb, to);
3351
3352         if (cap_unix(tcon->ses) &&
3353             (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
3354             ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
3355                 return generic_file_read_iter(iocb, to);
3356
3357         /*
3358          * We need to hold the sem to be sure nobody modifies lock list
3359          * with a brlock that prevents reading.
3360          */
3361         down_read(&cinode->lock_sem);
3362         if (!cifs_find_lock_conflict(cfile, iocb->ki_pos, iov_iter_count(to),
3363                                      tcon->ses->server->vals->shared_lock_type,
3364                                      NULL, CIFS_READ_OP))
3365                 rc = generic_file_read_iter(iocb, to);
3366         up_read(&cinode->lock_sem);
3367         return rc;
3368 }
3369
3370 static ssize_t
3371 cifs_read(struct file *file, char *read_data, size_t read_size, loff_t *offset)
3372 {
3373         int rc = -EACCES;
3374         unsigned int bytes_read = 0;
3375         unsigned int total_read;
3376         unsigned int current_read_size;
3377         unsigned int rsize;
3378         struct cifs_sb_info *cifs_sb;
3379         struct cifs_tcon *tcon;
3380         struct TCP_Server_Info *server;
3381         unsigned int xid;
3382         char *cur_offset;
3383         struct cifsFileInfo *open_file;
3384         struct cifs_io_parms io_parms;
3385         int buf_type = CIFS_NO_BUFFER;
3386         __u32 pid;
3387
3388         xid = get_xid();
3389         cifs_sb = CIFS_FILE_SB(file);
3390
3391         /* FIXME: set up handlers for larger reads and/or convert to async */
3392         rsize = min_t(unsigned int, cifs_sb->rsize, CIFSMaxBufSize);
3393
3394         if (file->private_data == NULL) {
3395                 rc = -EBADF;
3396                 free_xid(xid);
3397                 return rc;
3398         }
3399         open_file = file->private_data;
3400         tcon = tlink_tcon(open_file->tlink);
3401         server = tcon->ses->server;
3402
3403         if (!server->ops->sync_read) {
3404                 free_xid(xid);
3405                 return -ENOSYS;
3406         }
3407
3408         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
3409                 pid = open_file->pid;
3410         else
3411                 pid = current->tgid;
3412
3413         if ((file->f_flags & O_ACCMODE) == O_WRONLY)
3414                 cifs_dbg(FYI, "attempting read on write only file instance\n");
3415
3416         for (total_read = 0, cur_offset = read_data; read_size > total_read;
3417              total_read += bytes_read, cur_offset += bytes_read) {
3418                 do {
3419                         current_read_size = min_t(uint, read_size - total_read,
3420                                                   rsize);
3421                         /*
3422                          * For windows me and 9x we do not want to request more
3423                          * than it negotiated since it will refuse the read
3424                          * then.
3425                          */
3426                         if ((tcon->ses) && !(tcon->ses->capabilities &
3427                                 tcon->ses->server->vals->cap_large_files)) {
3428                                 current_read_size = min_t(uint,
3429                                         current_read_size, CIFSMaxBufSize);
3430                         }
3431                         if (open_file->invalidHandle) {
3432                                 rc = cifs_reopen_file(open_file, true);
3433                                 if (rc != 0)
3434                                         break;
3435                         }
3436                         io_parms.pid = pid;
3437                         io_parms.tcon = tcon;
3438                         io_parms.offset = *offset;
3439                         io_parms.length = current_read_size;
3440                         rc = server->ops->sync_read(xid, &open_file->fid, &io_parms,
3441                                                     &bytes_read, &cur_offset,
3442                                                     &buf_type);
3443                 } while (rc == -EAGAIN);
3444
3445                 if (rc || (bytes_read == 0)) {
3446                         if (total_read) {
3447                                 break;
3448                         } else {
3449                                 free_xid(xid);
3450                                 return rc;
3451                         }
3452                 } else {
3453                         cifs_stats_bytes_read(tcon, total_read);
3454                         *offset += bytes_read;
3455                 }
3456         }
3457         free_xid(xid);
3458         return total_read;
3459 }
3460
3461 /*
3462  * If the page is mmap'ed into a process' page tables, then we need to make
3463  * sure that it doesn't change while being written back.
3464  */
3465 static vm_fault_t
3466 cifs_page_mkwrite(struct vm_fault *vmf)
3467 {
3468         struct page *page = vmf->page;
3469
3470         lock_page(page);
3471         return VM_FAULT_LOCKED;
3472 }
3473
3474 static const struct vm_operations_struct cifs_file_vm_ops = {
3475         .fault = filemap_fault,
3476         .map_pages = filemap_map_pages,
3477         .page_mkwrite = cifs_page_mkwrite,
3478 };
3479
3480 int cifs_file_strict_mmap(struct file *file, struct vm_area_struct *vma)
3481 {
3482         int xid, rc = 0;
3483         struct inode *inode = file_inode(file);
3484
3485         xid = get_xid();
3486
3487         if (!CIFS_CACHE_READ(CIFS_I(inode)))
3488                 rc = cifs_zap_mapping(inode);
3489         if (!rc)
3490                 rc = generic_file_mmap(file, vma);
3491         if (!rc)
3492                 vma->vm_ops = &cifs_file_vm_ops;
3493
3494         free_xid(xid);
3495         return rc;
3496 }
3497
3498 int cifs_file_mmap(struct file *file, struct vm_area_struct *vma)
3499 {
3500         int rc, xid;
3501
3502         xid = get_xid();
3503
3504         rc = cifs_revalidate_file(file);
3505         if (rc)
3506                 cifs_dbg(FYI, "Validation prior to mmap failed, error=%d\n",
3507                          rc);
3508         if (!rc)
3509                 rc = generic_file_mmap(file, vma);
3510         if (!rc)
3511                 vma->vm_ops = &cifs_file_vm_ops;
3512
3513         free_xid(xid);
3514         return rc;
3515 }
3516
3517 static void
3518 cifs_readv_complete(struct work_struct *work)
3519 {
3520         unsigned int i, got_bytes;
3521         struct cifs_readdata *rdata = container_of(work,
3522                                                 struct cifs_readdata, work);
3523
3524         got_bytes = rdata->got_bytes;
3525         for (i = 0; i < rdata->nr_pages; i++) {
3526                 struct page *page = rdata->pages[i];
3527
3528                 lru_cache_add_file(page);
3529
3530                 if (rdata->result == 0 ||
3531                     (rdata->result == -EAGAIN && got_bytes)) {
3532                         flush_dcache_page(page);
3533                         SetPageUptodate(page);
3534                 }
3535
3536                 unlock_page(page);
3537
3538                 if (rdata->result == 0 ||
3539                     (rdata->result == -EAGAIN && got_bytes))
3540                         cifs_readpage_to_fscache(rdata->mapping->host, page);
3541
3542                 got_bytes -= min_t(unsigned int, PAGE_SIZE, got_bytes);
3543
3544                 put_page(page);
3545                 rdata->pages[i] = NULL;
3546         }
3547         kref_put(&rdata->refcount, cifs_readdata_release);
3548 }
3549
3550 static int
3551 readpages_fill_pages(struct TCP_Server_Info *server,
3552                      struct cifs_readdata *rdata, struct iov_iter *iter,
3553                      unsigned int len)
3554 {
3555         int result = 0;
3556         unsigned int i;
3557         u64 eof;
3558         pgoff_t eof_index;
3559         unsigned int nr_pages = rdata->nr_pages;
3560
3561         /* determine the eof that the server (probably) has */
3562         eof = CIFS_I(rdata->mapping->host)->server_eof;
3563         eof_index = eof ? (eof - 1) >> PAGE_SHIFT : 0;
3564         cifs_dbg(FYI, "eof=%llu eof_index=%lu\n", eof, eof_index);
3565
3566         rdata->got_bytes = 0;
3567         rdata->tailsz = PAGE_SIZE;
3568         for (i = 0; i < nr_pages; i++) {
3569                 struct page *page = rdata->pages[i];
3570                 size_t n = PAGE_SIZE;
3571
3572                 if (len >= PAGE_SIZE) {
3573                         len -= PAGE_SIZE;
3574                 } else if (len > 0) {
3575                         /* enough for partial page, fill and zero the rest */
3576                         zero_user(page, len, PAGE_SIZE - len);
3577                         n = rdata->tailsz = len;
3578                         len = 0;
3579                 } else if (page->index > eof_index) {
3580                         /*
3581                          * The VFS will not try to do readahead past the
3582                          * i_size, but it's possible that we have outstanding
3583                          * writes with gaps in the middle and the i_size hasn't
3584                          * caught up yet. Populate those with zeroed out pages
3585                          * to prevent the VFS from repeatedly attempting to
3586                          * fill them until the writes are flushed.
3587                          */
3588                         zero_user(page, 0, PAGE_SIZE);
3589                         lru_cache_add_file(page);
3590                         flush_dcache_page(page);
3591                         SetPageUptodate(page);
3592                         unlock_page(page);
3593                         put_page(page);
3594                         rdata->pages[i] = NULL;
3595                         rdata->nr_pages--;
3596                         continue;
3597                 } else {
3598                         /* no need to hold page hostage */
3599                         lru_cache_add_file(page);
3600                         unlock_page(page);
3601                         put_page(page);
3602                         rdata->pages[i] = NULL;
3603                         rdata->nr_pages--;
3604                         continue;
3605                 }
3606
3607                 if (iter)
3608                         result = copy_page_from_iter(page, 0, n, iter);
3609 #ifdef CONFIG_CIFS_SMB_DIRECT
3610                 else if (rdata->mr)
3611                         result = n;
3612 #endif
3613                 else
3614                         result = cifs_read_page_from_socket(server, page, n);
3615                 if (result < 0)
3616                         break;
3617
3618                 rdata->got_bytes += result;
3619         }
3620
3621         return rdata->got_bytes > 0 && result != -ECONNABORTED ?
3622                                                 rdata->got_bytes : result;
3623 }
3624
3625 static int
3626 cifs_readpages_read_into_pages(struct TCP_Server_Info *server,
3627                                struct cifs_readdata *rdata, unsigned int len)
3628 {
3629         return readpages_fill_pages(server, rdata, NULL, len);
3630 }
3631
3632 static int
3633 cifs_readpages_copy_into_pages(struct TCP_Server_Info *server,
3634                                struct cifs_readdata *rdata,
3635                                struct iov_iter *iter)
3636 {
3637         return readpages_fill_pages(server, rdata, iter, iter->count);
3638 }
3639
3640 static int
3641 readpages_get_pages(struct address_space *mapping, struct list_head *page_list,
3642                     unsigned int rsize, struct list_head *tmplist,
3643                     unsigned int *nr_pages, loff_t *offset, unsigned int *bytes)
3644 {
3645         struct page *page, *tpage;
3646         unsigned int expected_index;
3647         int rc;
3648         gfp_t gfp = readahead_gfp_mask(mapping);
3649
3650         INIT_LIST_HEAD(tmplist);
3651
3652         page = list_entry(page_list->prev, struct page, lru);
3653
3654         /*
3655          * Lock the page and put it in the cache. Since no one else
3656          * should have access to this page, we're safe to simply set
3657          * PG_locked without checking it first.
3658          */
3659         __SetPageLocked(page);
3660         rc = add_to_page_cache_locked(page, mapping,
3661                                       page->index, gfp);
3662
3663         /* give up if we can't stick it in the cache */
3664         if (rc) {
3665                 __ClearPageLocked(page);
3666                 return rc;
3667         }
3668
3669         /* move first page to the tmplist */
3670         *offset = (loff_t)page->index << PAGE_SHIFT;
3671         *bytes = PAGE_SIZE;
3672         *nr_pages = 1;
3673         list_move_tail(&page->lru, tmplist);
3674
3675         /* now try and add more pages onto the request */
3676         expected_index = page->index + 1;
3677         list_for_each_entry_safe_reverse(page, tpage, page_list, lru) {
3678                 /* discontinuity ? */
3679                 if (page->index != expected_index)
3680                         break;
3681
3682                 /* would this page push the read over the rsize? */
3683                 if (*bytes + PAGE_SIZE > rsize)
3684                         break;
3685
3686                 __SetPageLocked(page);
3687                 if (add_to_page_cache_locked(page, mapping, page->index, gfp)) {
3688                         __ClearPageLocked(page);
3689                         break;
3690                 }
3691                 list_move_tail(&page->lru, tmplist);
3692                 (*bytes) += PAGE_SIZE;
3693                 expected_index++;
3694                 (*nr_pages)++;
3695         }
3696         return rc;
3697 }
3698
3699 static int cifs_readpages(struct file *file, struct address_space *mapping,
3700         struct list_head *page_list, unsigned num_pages)
3701 {
3702         int rc;
3703         struct list_head tmplist;
3704         struct cifsFileInfo *open_file = file->private_data;
3705         struct cifs_sb_info *cifs_sb = CIFS_FILE_SB(file);
3706         struct TCP_Server_Info *server;
3707         pid_t pid;
3708
3709         /*
3710          * Reads as many pages as possible from fscache. Returns -ENOBUFS
3711          * immediately if the cookie is negative
3712          *
3713          * After this point, every page in the list might have PG_fscache set,
3714          * so we will need to clean that up off of every page we don't use.
3715          */
3716         rc = cifs_readpages_from_fscache(mapping->host, mapping, page_list,
3717                                          &num_pages);
3718         if (rc == 0)
3719                 return rc;
3720
3721         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
3722                 pid = open_file->pid;
3723         else
3724                 pid = current->tgid;
3725
3726         rc = 0;
3727         server = tlink_tcon(open_file->tlink)->ses->server;
3728
3729         cifs_dbg(FYI, "%s: file=%p mapping=%p num_pages=%u\n",
3730                  __func__, file, mapping, num_pages);
3731
3732         /*
3733          * Start with the page at end of list and move it to private
3734          * list. Do the same with any following pages until we hit
3735          * the rsize limit, hit an index discontinuity, or run out of
3736          * pages. Issue the async read and then start the loop again
3737          * until the list is empty.
3738          *
3739          * Note that list order is important. The page_list is in
3740          * the order of declining indexes. When we put the pages in
3741          * the rdata->pages, then we want them in increasing order.
3742          */
3743         while (!list_empty(page_list)) {
3744                 unsigned int i, nr_pages, bytes, rsize;
3745                 loff_t offset;
3746                 struct page *page, *tpage;
3747                 struct cifs_readdata *rdata;
3748                 unsigned credits;
3749
3750                 rc = server->ops->wait_mtu_credits(server, cifs_sb->rsize,
3751                                                    &rsize, &credits);
3752                 if (rc)
3753                         break;
3754
3755                 /*
3756                  * Give up immediately if rsize is too small to read an entire
3757                  * page. The VFS will fall back to readpage. We should never
3758                  * reach this point however since we set ra_pages to 0 when the
3759                  * rsize is smaller than a cache page.
3760                  */
3761                 if (unlikely(rsize < PAGE_SIZE)) {
3762                         add_credits_and_wake_if(server, credits, 0);
3763                         return 0;
3764                 }
3765
3766                 rc = readpages_get_pages(mapping, page_list, rsize, &tmplist,
3767                                          &nr_pages, &offset, &bytes);
3768                 if (rc) {
3769                         add_credits_and_wake_if(server, credits, 0);
3770                         break;
3771                 }
3772
3773                 rdata = cifs_readdata_alloc(nr_pages, cifs_readv_complete);
3774                 if (!rdata) {
3775                         /* best to give up if we're out of mem */
3776                         list_for_each_entry_safe(page, tpage, &tmplist, lru) {
3777                                 list_del(&page->lru);
3778                                 lru_cache_add_file(page);
3779                                 unlock_page(page);
3780                                 put_page(page);
3781                         }
3782                         rc = -ENOMEM;
3783                         add_credits_and_wake_if(server, credits, 0);
3784                         break;
3785                 }
3786
3787                 rdata->cfile = cifsFileInfo_get(open_file);
3788                 rdata->mapping = mapping;
3789                 rdata->offset = offset;
3790                 rdata->bytes = bytes;
3791                 rdata->pid = pid;
3792                 rdata->pagesz = PAGE_SIZE;
3793                 rdata->read_into_pages = cifs_readpages_read_into_pages;
3794                 rdata->copy_into_pages = cifs_readpages_copy_into_pages;
3795                 rdata->credits = credits;
3796
3797                 list_for_each_entry_safe(page, tpage, &tmplist, lru) {
3798                         list_del(&page->lru);
3799                         rdata->pages[rdata->nr_pages++] = page;
3800                 }
3801
3802                 if (!rdata->cfile->invalidHandle ||
3803                     !(rc = cifs_reopen_file(rdata->cfile, true)))
3804                         rc = server->ops->async_readv(rdata);
3805                 if (rc) {
3806                         add_credits_and_wake_if(server, rdata->credits, 0);
3807                         for (i = 0; i < rdata->nr_pages; i++) {
3808                                 page = rdata->pages[i];
3809                                 lru_cache_add_file(page);
3810                                 unlock_page(page);
3811                                 put_page(page);
3812                         }
3813                         /* Fallback to the readpage in error/reconnect cases */
3814                         kref_put(&rdata->refcount, cifs_readdata_release);
3815                         break;
3816                 }
3817
3818                 kref_put(&rdata->refcount, cifs_readdata_release);
3819         }
3820
3821         /* Any pages that have been shown to fscache but didn't get added to
3822          * the pagecache must be uncached before they get returned to the
3823          * allocator.
3824          */
3825         cifs_fscache_readpages_cancel(mapping->host, page_list);
3826         return rc;
3827 }
3828
3829 /*
3830  * cifs_readpage_worker must be called with the page pinned
3831  */
3832 static int cifs_readpage_worker(struct file *file, struct page *page,
3833         loff_t *poffset)
3834 {
3835         char *read_data;
3836         int rc;
3837
3838         /* Is the page cached? */
3839         rc = cifs_readpage_from_fscache(file_inode(file), page);
3840         if (rc == 0)
3841                 goto read_complete;
3842
3843         read_data = kmap(page);
3844         /* for reads over a certain size could initiate async read ahead */
3845
3846         rc = cifs_read(file, read_data, PAGE_SIZE, poffset);
3847
3848         if (rc < 0)
3849                 goto io_error;
3850         else
3851                 cifs_dbg(FYI, "Bytes read %d\n", rc);
3852
3853         file_inode(file)->i_atime =
3854                 current_time(file_inode(file));
3855
3856         if (PAGE_SIZE > rc)
3857                 memset(read_data + rc, 0, PAGE_SIZE - rc);
3858
3859         flush_dcache_page(page);
3860         SetPageUptodate(page);
3861
3862         /* send this page to the cache */
3863         cifs_readpage_to_fscache(file_inode(file), page);
3864
3865         rc = 0;
3866
3867 io_error:
3868         kunmap(page);
3869         unlock_page(page);
3870
3871 read_complete:
3872         return rc;
3873 }
3874
3875 static int cifs_readpage(struct file *file, struct page *page)
3876 {
3877         loff_t offset = (loff_t)page->index << PAGE_SHIFT;
3878         int rc = -EACCES;
3879         unsigned int xid;
3880
3881         xid = get_xid();
3882
3883         if (file->private_data == NULL) {
3884                 rc = -EBADF;
3885                 free_xid(xid);
3886                 return rc;
3887         }
3888
3889         cifs_dbg(FYI, "readpage %p at offset %d 0x%x\n",
3890                  page, (int)offset, (int)offset);
3891
3892         rc = cifs_readpage_worker(file, page, &offset);
3893
3894         free_xid(xid);
3895         return rc;
3896 }
3897
3898 static int is_inode_writable(struct cifsInodeInfo *cifs_inode)
3899 {
3900         struct cifsFileInfo *open_file;
3901         struct cifs_tcon *tcon =
3902                 cifs_sb_master_tcon(CIFS_SB(cifs_inode->vfs_inode.i_sb));
3903
3904         spin_lock(&tcon->open_file_lock);
3905         list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
3906                 if (OPEN_FMODE(open_file->f_flags) & FMODE_WRITE) {
3907                         spin_unlock(&tcon->open_file_lock);
3908                         return 1;
3909                 }
3910         }
3911         spin_unlock(&tcon->open_file_lock);
3912         return 0;
3913 }
3914
3915 /* We do not want to update the file size from server for inodes
3916    open for write - to avoid races with writepage extending
3917    the file - in the future we could consider allowing
3918    refreshing the inode only on increases in the file size
3919    but this is tricky to do without racing with writebehind
3920    page caching in the current Linux kernel design */
3921 bool is_size_safe_to_change(struct cifsInodeInfo *cifsInode, __u64 end_of_file)
3922 {
3923         if (!cifsInode)
3924                 return true;
3925
3926         if (is_inode_writable(cifsInode)) {
3927                 /* This inode is open for write at least once */
3928                 struct cifs_sb_info *cifs_sb;
3929
3930                 cifs_sb = CIFS_SB(cifsInode->vfs_inode.i_sb);
3931                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DIRECT_IO) {
3932                         /* since no page cache to corrupt on directio
3933                         we can change size safely */
3934                         return true;
3935                 }
3936
3937                 if (i_size_read(&cifsInode->vfs_inode) < end_of_file)
3938                         return true;
3939
3940                 return false;
3941         } else
3942                 return true;
3943 }
3944
3945 static int cifs_write_begin(struct file *file, struct address_space *mapping,
3946                         loff_t pos, unsigned len, unsigned flags,
3947                         struct page **pagep, void **fsdata)
3948 {
3949         int oncethru = 0;
3950         pgoff_t index = pos >> PAGE_SHIFT;
3951         loff_t offset = pos & (PAGE_SIZE - 1);
3952         loff_t page_start = pos & PAGE_MASK;
3953         loff_t i_size;
3954         struct page *page;
3955         int rc = 0;
3956
3957         cifs_dbg(FYI, "write_begin from %lld len %d\n", (long long)pos, len);
3958
3959 start:
3960         page = grab_cache_page_write_begin(mapping, index, flags);
3961         if (!page) {
3962                 rc = -ENOMEM;
3963                 goto out;
3964         }
3965
3966         if (PageUptodate(page))
3967                 goto out;
3968
3969         /*
3970          * If we write a full page it will be up to date, no need to read from
3971          * the server. If the write is short, we'll end up doing a sync write
3972          * instead.
3973          */
3974         if (len == PAGE_SIZE)
3975                 goto out;
3976
3977         /*
3978          * optimize away the read when we have an oplock, and we're not
3979          * expecting to use any of the data we'd be reading in. That
3980          * is, when the page lies beyond the EOF, or straddles the EOF
3981          * and the write will cover all of the existing data.
3982          */
3983         if (CIFS_CACHE_READ(CIFS_I(mapping->host))) {
3984                 i_size = i_size_read(mapping->host);
3985                 if (page_start >= i_size ||
3986                     (offset == 0 && (pos + len) >= i_size)) {
3987                         zero_user_segments(page, 0, offset,
3988                                            offset + len,
3989                                            PAGE_SIZE);
3990                         /*
3991                          * PageChecked means that the parts of the page
3992                          * to which we're not writing are considered up
3993                          * to date. Once the data is copied to the
3994                          * page, it can be set uptodate.
3995                          */
3996                         SetPageChecked(page);
3997                         goto out;
3998                 }
3999         }
4000
4001         if ((file->f_flags & O_ACCMODE) != O_WRONLY && !oncethru) {
4002                 /*
4003                  * might as well read a page, it is fast enough. If we get
4004                  * an error, we don't need to return it. cifs_write_end will
4005                  * do a sync write instead since PG_uptodate isn't set.
4006                  */
4007                 cifs_readpage_worker(file, page, &page_start);
4008                 put_page(page);
4009                 oncethru = 1;
4010                 goto start;
4011         } else {
4012                 /* we could try using another file handle if there is one -
4013                    but how would we lock it to prevent close of that handle
4014                    racing with this read? In any case
4015                    this will be written out by write_end so is fine */
4016         }
4017 out:
4018         *pagep = page;
4019         return rc;
4020 }
4021
4022 static int cifs_release_page(struct page *page, gfp_t gfp)
4023 {
4024         if (PagePrivate(page))
4025                 return 0;
4026
4027         return cifs_fscache_release_page(page, gfp);
4028 }
4029
4030 static void cifs_invalidate_page(struct page *page, unsigned int offset,
4031                                  unsigned int length)
4032 {
4033         struct cifsInodeInfo *cifsi = CIFS_I(page->mapping->host);
4034
4035         if (offset == 0 && length == PAGE_SIZE)
4036                 cifs_fscache_invalidate_page(page, &cifsi->vfs_inode);
4037 }
4038
4039 static int cifs_launder_page(struct page *page)
4040 {
4041         int rc = 0;
4042         loff_t range_start = page_offset(page);
4043         loff_t range_end = range_start + (loff_t)(PAGE_SIZE - 1);
4044         struct writeback_control wbc = {
4045                 .sync_mode = WB_SYNC_ALL,
4046                 .nr_to_write = 0,
4047                 .range_start = range_start,
4048                 .range_end = range_end,
4049         };
4050
4051         cifs_dbg(FYI, "Launder page: %p\n", page);
4052
4053         if (clear_page_dirty_for_io(page))
4054                 rc = cifs_writepage_locked(page, &wbc);
4055
4056         cifs_fscache_invalidate_page(page, page->mapping->host);
4057         return rc;
4058 }
4059
4060 void cifs_oplock_break(struct work_struct *work)
4061 {
4062         struct cifsFileInfo *cfile = container_of(work, struct cifsFileInfo,
4063                                                   oplock_break);
4064         struct inode *inode = d_inode(cfile->dentry);
4065         struct cifsInodeInfo *cinode = CIFS_I(inode);
4066         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
4067         struct TCP_Server_Info *server = tcon->ses->server;
4068         int rc = 0;
4069
4070         wait_on_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS,
4071                         TASK_UNINTERRUPTIBLE);
4072
4073         server->ops->downgrade_oplock(server, cinode,
4074                 test_bit(CIFS_INODE_DOWNGRADE_OPLOCK_TO_L2, &cinode->flags));
4075
4076         if (!CIFS_CACHE_WRITE(cinode) && CIFS_CACHE_READ(cinode) &&
4077                                                 cifs_has_mand_locks(cinode)) {
4078                 cifs_dbg(FYI, "Reset oplock to None for inode=%p due to mand locks\n",
4079                          inode);
4080                 cinode->oplock = 0;
4081         }
4082
4083         if (inode && S_ISREG(inode->i_mode)) {
4084                 if (CIFS_CACHE_READ(cinode))
4085                         break_lease(inode, O_RDONLY);
4086                 else
4087                         break_lease(inode, O_WRONLY);
4088                 rc = filemap_fdatawrite(inode->i_mapping);
4089                 if (!CIFS_CACHE_READ(cinode)) {
4090                         rc = filemap_fdatawait(inode->i_mapping);
4091                         mapping_set_error(inode->i_mapping, rc);
4092                         cifs_zap_mapping(inode);
4093                 }
4094                 cifs_dbg(FYI, "Oplock flush inode %p rc %d\n", inode, rc);
4095         }
4096
4097         rc = cifs_push_locks(cfile);
4098         if (rc)
4099                 cifs_dbg(VFS, "Push locks rc = %d\n", rc);
4100
4101         /*
4102          * releasing stale oplock after recent reconnect of smb session using
4103          * a now incorrect file handle is not a data integrity issue but do
4104          * not bother sending an oplock release if session to server still is
4105          * disconnected since oplock already released by the server
4106          */
4107         if (!cfile->oplock_break_cancelled) {
4108                 rc = tcon->ses->server->ops->oplock_response(tcon, &cfile->fid,
4109                                                              cinode);
4110                 cifs_dbg(FYI, "Oplock release rc = %d\n", rc);
4111         }
4112         cifs_done_oplock_break(cinode);
4113 }
4114
4115 /*
4116  * The presence of cifs_direct_io() in the address space ops vector
4117  * allowes open() O_DIRECT flags which would have failed otherwise.
4118  *
4119  * In the non-cached mode (mount with cache=none), we shunt off direct read and write requests
4120  * so this method should never be called.
4121  *
4122  * Direct IO is not yet supported in the cached mode.
4123  */
4124 static ssize_t
4125 cifs_direct_io(struct kiocb *iocb, struct iov_iter *iter)
4126 {
4127         /*
4128          * FIXME
4129          * Eventually need to support direct IO for non forcedirectio mounts
4130          */
4131         return -EINVAL;
4132 }
4133
4134
4135 const struct address_space_operations cifs_addr_ops = {
4136         .readpage = cifs_readpage,
4137         .readpages = cifs_readpages,
4138         .writepage = cifs_writepage,
4139         .writepages = cifs_writepages,
4140         .write_begin = cifs_write_begin,
4141         .write_end = cifs_write_end,
4142         .set_page_dirty = __set_page_dirty_nobuffers,
4143         .releasepage = cifs_release_page,
4144         .direct_IO = cifs_direct_io,
4145         .invalidatepage = cifs_invalidate_page,
4146         .launder_page = cifs_launder_page,
4147 };
4148
4149 /*
4150  * cifs_readpages requires the server to support a buffer large enough to
4151  * contain the header plus one complete page of data.  Otherwise, we need
4152  * to leave cifs_readpages out of the address space operations.
4153  */
4154 const struct address_space_operations cifs_addr_ops_smallbuf = {
4155         .readpage = cifs_readpage,
4156         .writepage = cifs_writepage,
4157         .writepages = cifs_writepages,
4158         .write_begin = cifs_write_begin,
4159         .write_end = cifs_write_end,
4160         .set_page_dirty = __set_page_dirty_nobuffers,
4161         .releasepage = cifs_release_page,
4162         .invalidatepage = cifs_invalidate_page,
4163         .launder_page = cifs_launder_page,
4164 };