git.oblomov.eu Git - linux-2.6/blob - fs/cifs/transport.c

   1 /*
   2  *   fs/cifs/transport.c
   3  *
   4  *   Copyright (C) International Business Machines  Corp., 2002,2008
   5  *   Author(s): Steve French (sfrench@us.ibm.com)
   6  *   Jeremy Allison (jra@samba.org) 2006.
   7  *
   8  *   This library is free software; you can redistribute it and/or modify
   9  *   it under the terms of the GNU Lesser General Public License as published
  10  *   by the Free Software Foundation; either version 2.1 of the License, or
  11  *   (at your option) any later version.
  12  *
  13  *   This library is distributed in the hope that it will be useful,
  14  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  16  *   the GNU Lesser General Public License for more details.
  17  *
  18  *   You should have received a copy of the GNU Lesser General Public License
  19  *   along with this library; if not, write to the Free Software
  20  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  21  */
  22
  23 #include <linux/fs.h>
  24 #include <linux/list.h>
  25 #include <linux/wait.h>
  26 #include <linux/net.h>
  27 #include <linux/delay.h>
  28 #include <asm/uaccess.h>
  29 #include <asm/processor.h>
  30 #include <linux/mempool.h>
  31 #include "cifspdu.h"
  32 #include "cifsglob.h"
  33 #include "cifsproto.h"
  34 #include "cifs_debug.h"
  35
  36 extern mempool_t *cifs_mid_poolp;
  37 extern struct kmem_cache *cifs_oplock_cachep;
  38
  39 static struct mid_q_entry *
  40 AllocMidQEntry(const struct smb_hdr *smb_buffer, struct TCP_Server_Info *server)
  41 {
  42         struct mid_q_entry *temp;
  43
  44         if (server == NULL) {
  45                 cERROR(1, ("Null TCP session in AllocMidQEntry"));
  46                 return NULL;
  47         }
  48
  49         temp = mempool_alloc(cifs_mid_poolp, GFP_NOFS);
  50         if (temp == NULL)
  51                 return temp;
  52         else {
  53                 memset(temp, 0, sizeof(struct mid_q_entry));
  54                 temp->mid = smb_buffer->Mid;    /* always LE */
  55                 temp->pid = current->pid;
  56                 temp->command = smb_buffer->Command;
  57                 cFYI(1, ("For smb_command %d", temp->command));
  58         /*      do_gettimeofday(&temp->when_sent);*/ /* easier to use jiffies */
  59                 /* when mid allocated can be before when sent */
  60                 temp->when_alloc = jiffies;
  61                 temp->tsk = current;
  62         }
  63
  64         spin_lock(&GlobalMid_Lock);
  65         list_add_tail(&temp->qhead, &server->pending_mid_q);
  66         atomic_inc(&midCount);
  67         temp->midState = MID_REQUEST_ALLOCATED;
  68         spin_unlock(&GlobalMid_Lock);
  69         return temp;
  70 }
  71
  72 static void
  73 DeleteMidQEntry(struct mid_q_entry *midEntry)
  74 {
  75 #ifdef CONFIG_CIFS_STATS2
  76         unsigned long now;
  77 #endif
  78         spin_lock(&GlobalMid_Lock);
  79         midEntry->midState = MID_FREE;
  80         list_del(&midEntry->qhead);
  81         atomic_dec(&midCount);
  82         spin_unlock(&GlobalMid_Lock);
  83         if (midEntry->largeBuf)
  84                 cifs_buf_release(midEntry->resp_buf);
  85         else
  86                 cifs_small_buf_release(midEntry->resp_buf);
  87 #ifdef CONFIG_CIFS_STATS2
  88         now = jiffies;
  89         /* commands taking longer than one second are indications that
  90            something is wrong, unless it is quite a slow link or server */
  91         if ((now - midEntry->when_alloc) > HZ) {
  92                 if ((cifsFYI & CIFS_TIMER) &&
  93                    (midEntry->command != SMB_COM_LOCKING_ANDX)) {
  94                         printk(KERN_DEBUG " CIFS slow rsp: cmd %d mid %d",
  95                                midEntry->command, midEntry->mid);
  96                         printk(" A: 0x%lx S: 0x%lx R: 0x%lx\n",
  97                                now - midEntry->when_alloc,
  98                                now - midEntry->when_sent,
  99                                now - midEntry->when_received);
 100                 }
 101         }
 102 #endif
 103         mempool_free(midEntry, cifs_mid_poolp);
 104 }
 105
 106 struct oplock_q_entry *
 107 AllocOplockQEntry(struct inode *pinode, __u16 fid, struct cifsTconInfo *tcon)
 108 {
 109         struct oplock_q_entry *temp;
 110         if ((pinode == NULL) || (tcon == NULL)) {
 111                 cERROR(1, ("Null parms passed to AllocOplockQEntry"));
 112                 return NULL;
 113         }
 114         temp = (struct oplock_q_entry *) kmem_cache_alloc(cifs_oplock_cachep,
 115                                                        GFP_KERNEL);
 116         if (temp == NULL)
 117                 return temp;
 118         else {
 119                 temp->pinode = pinode;
 120                 temp->tcon = tcon;
 121                 temp->netfid = fid;
 122                 spin_lock(&GlobalMid_Lock);
 123                 list_add_tail(&temp->qhead, &GlobalOplock_Q);
 124                 spin_unlock(&GlobalMid_Lock);
 125         }
 126         return temp;
 127
 128 }
 129
 130 void DeleteOplockQEntry(struct oplock_q_entry *oplockEntry)
 131 {
 132         spin_lock(&GlobalMid_Lock);
 133     /* should we check if list empty first? */
 134         list_del(&oplockEntry->qhead);
 135         spin_unlock(&GlobalMid_Lock);
 136         kmem_cache_free(cifs_oplock_cachep, oplockEntry);
 137 }
 138
 139
 140 void DeleteTconOplockQEntries(struct cifsTconInfo *tcon)
 141 {
 142         struct oplock_q_entry *temp;
 143
 144         if (tcon == NULL)
 145                 return;
 146
 147         spin_lock(&GlobalMid_Lock);
 148         list_for_each_entry(temp, &GlobalOplock_Q, qhead) {
 149                 if ((temp->tcon) && (temp->tcon == tcon)) {
 150                         list_del(&temp->qhead);
 151                         kmem_cache_free(cifs_oplock_cachep, temp);
 152                 }
 153         }
 154         spin_unlock(&GlobalMid_Lock);
 155 }
 156
 157 int
 158 smb_send(struct socket *ssocket, struct smb_hdr *smb_buffer,
 159          unsigned int smb_buf_length, struct sockaddr *sin, bool noblocksnd)
 160 {
 161         int rc = 0;
 162         int i = 0;
 163         struct msghdr smb_msg;
 164         struct kvec iov;
 165         unsigned len = smb_buf_length + 4;
 166
 167         if (ssocket == NULL)
 168                 return -ENOTSOCK; /* BB eventually add reconnect code here */
 169         iov.iov_base = smb_buffer;
 170         iov.iov_len = len;
 171
 172         smb_msg.msg_name = sin;
 173         smb_msg.msg_namelen = sizeof(struct sockaddr);
 174         smb_msg.msg_control = NULL;
 175         smb_msg.msg_controllen = 0;
 176         if (noblocksnd)
 177                 smb_msg.msg_flags = MSG_DONTWAIT + MSG_NOSIGNAL;
 178         else
 179                 smb_msg.msg_flags = MSG_NOSIGNAL;
 180
 181         /* smb header is converted in header_assemble. bcc and rest of SMB word
 182            area, and byte area if necessary, is converted to littleendian in
 183            cifssmb.c and RFC1001 len is converted to bigendian in smb_send
 184            Flags2 is converted in SendReceive */
 185
 186         smb_buffer->smb_buf_length = cpu_to_be32(smb_buffer->smb_buf_length);
 187         cFYI(1, ("Sending smb of length %d", smb_buf_length));
 188         dump_smb(smb_buffer, len);
 189
 190         while (len > 0) {
 191                 rc = kernel_sendmsg(ssocket, &smb_msg, &iov, 1, len);
 192                 if ((rc == -ENOSPC) || (rc == -EAGAIN)) {
 193                         i++;
 194                 /* smaller timeout here than send2 since smaller size */
 195                 /* Although it may not be required, this also is smaller
 196                    oplock break time */
 197                         if (i > 12) {
 198                                 cERROR(1,
 199                                    ("sends on sock %p stuck for 7 seconds",
 200                                     ssocket));
 201                                 rc = -EAGAIN;
 202                                 break;
 203                         }
 204                         msleep(1 << i);
 205                         continue;
 206                 }
 207                 if (rc < 0)
 208                         break;
 209                 else
 210                         i = 0; /* reset i after each successful send */
 211                 iov.iov_base += rc;
 212                 iov.iov_len -= rc;
 213                 len -= rc;
 214         }
 215
 216         if (rc < 0) {
 217                 cERROR(1, ("Error %d sending data on socket to server", rc));
 218         } else {
 219                 rc = 0;
 220         }
 221
 222         /* Don't want to modify the buffer as a
 223            side effect of this call. */
 224         smb_buffer->smb_buf_length = smb_buf_length;
 225
 226         return rc;
 227 }
 228
 229 static int
 230 smb_send2(struct TCP_Server_Info *server, struct kvec *iov, int n_vec,
 231           struct sockaddr *sin, bool noblocksnd)
 232 {
 233         int rc = 0;
 234         int i = 0;
 235         struct msghdr smb_msg;
 236         struct smb_hdr *smb_buffer = iov[0].iov_base;
 237         unsigned int len = iov[0].iov_len;
 238         unsigned int total_len;
 239         int first_vec = 0;
 240         unsigned int smb_buf_length = smb_buffer->smb_buf_length;
 241         struct socket *ssocket = server->ssocket;
 242
 243         if (ssocket == NULL)
 244                 return -ENOTSOCK; /* BB eventually add reconnect code here */
 245
 246         smb_msg.msg_name = sin;
 247         smb_msg.msg_namelen = sizeof(struct sockaddr);
 248         smb_msg.msg_control = NULL;
 249         smb_msg.msg_controllen = 0;
 250         if (noblocksnd)
 251                 smb_msg.msg_flags = MSG_DONTWAIT + MSG_NOSIGNAL;
 252         else
 253                 smb_msg.msg_flags = MSG_NOSIGNAL;
 254
 255         /* smb header is converted in header_assemble. bcc and rest of SMB word
 256            area, and byte area if necessary, is converted to littleendian in
 257            cifssmb.c and RFC1001 len is converted to bigendian in smb_send
 258            Flags2 is converted in SendReceive */
 259
 260
 261         total_len = 0;
 262         for (i = 0; i < n_vec; i++)
 263                 total_len += iov[i].iov_len;
 264
 265         smb_buffer->smb_buf_length = cpu_to_be32(smb_buffer->smb_buf_length);
 266         cFYI(1, ("Sending smb:  total_len %d", total_len));
 267         dump_smb(smb_buffer, len);
 268
 269         i = 0;
 270         while (total_len) {
 271                 rc = kernel_sendmsg(ssocket, &smb_msg, &iov[first_vec],
 272                                     n_vec - first_vec, total_len);
 273                 if ((rc == -ENOSPC) || (rc == -EAGAIN)) {
 274                         i++;
 275                         if (i >= 14) {
 276                                 cERROR(1,
 277                                    ("sends on sock %p stuck for 15 seconds",
 278                                     ssocket));
 279                                 rc = -EAGAIN;
 280                                 break;
 281                         }
 282                         msleep(1 << i);
 283                         continue;
 284                 }
 285                 if (rc < 0)
 286                         break;
 287
 288                 if (rc == total_len) {
 289                         total_len = 0;
 290                         break;
 291                 } else if (rc > total_len) {
 292                         cERROR(1, ("sent %d requested %d", rc, total_len));
 293                         break;
 294                 }
 295                 if (rc == 0) {
 296                         /* should never happen, letting socket clear before
 297                            retrying is our only obvious option here */
 298                         cERROR(1, ("tcp sent no data"));
 299                         msleep(500);
 300                         continue;
 301                 }
 302                 total_len -= rc;
 303                 /* the line below resets i */
 304                 for (i = first_vec; i < n_vec; i++) {
 305                         if (iov[i].iov_len) {
 306                                 if (rc > iov[i].iov_len) {
 307                                         rc -= iov[i].iov_len;
 308                                         iov[i].iov_len = 0;
 309                                 } else {
 310                                         iov[i].iov_base += rc;
 311                                         iov[i].iov_len -= rc;
 312                                         first_vec = i;
 313                                         break;
 314                                 }
 315                         }
 316                 }
 317                 i = 0; /* in case we get ENOSPC on the next send */
 318         }
 319
 320         if ((total_len > 0) && (total_len != smb_buf_length + 4)) {
 321                 cFYI(1, ("partial send (%d remaining), terminating session",
 322                         total_len));
 323                 /* If we have only sent part of an SMB then the next SMB
 324                    could be taken as the remainder of this one.  We need
 325                    to kill the socket so the server throws away the partial
 326                    SMB */
 327                 server->tcpStatus = CifsNeedReconnect;
 328         }
 329
 330         if (rc < 0) {
 331                 cERROR(1, ("Error %d sending data on socket to server", rc));
 332         } else
 333                 rc = 0;
 334
 335         /* Don't want to modify the buffer as a
 336            side effect of this call. */
 337         smb_buffer->smb_buf_length = smb_buf_length;
 338
 339         return rc;
 340 }
 341
 342 static int wait_for_free_request(struct cifsSesInfo *ses, const int long_op)
 343 {
 344         if (long_op == CIFS_ASYNC_OP) {
 345                 /* oplock breaks must not be held up */
 346                 atomic_inc(&ses->server->inFlight);
 347                 return 0;
 348         }
 349
 350         spin_lock(&GlobalMid_Lock);
 351         while (1) {
 352                 if (atomic_read(&ses->server->inFlight) >=
 353                                 cifs_max_pending){
 354                         spin_unlock(&GlobalMid_Lock);
 355 #ifdef CONFIG_CIFS_STATS2
 356                         atomic_inc(&ses->server->num_waiters);
 357 #endif
 358                         wait_event(ses->server->request_q,
 359                                    atomic_read(&ses->server->inFlight)
 360                                      < cifs_max_pending);
 361 #ifdef CONFIG_CIFS_STATS2
 362                         atomic_dec(&ses->server->num_waiters);
 363 #endif
 364                         spin_lock(&GlobalMid_Lock);
 365                 } else {
 366                         if (ses->server->tcpStatus == CifsExiting) {
 367                                 spin_unlock(&GlobalMid_Lock);
 368                                 return -ENOENT;
 369                         }
 370
 371                         /* can not count locking commands against total
 372                            as they are allowed to block on server */
 373
 374                         /* update # of requests on the wire to server */
 375                         if (long_op != CIFS_BLOCKING_OP)
 376                                 atomic_inc(&ses->server->inFlight);
 377                         spin_unlock(&GlobalMid_Lock);
 378                         break;
 379                 }
 380         }
 381         return 0;
 382 }
 383
 384 static int allocate_mid(struct cifsSesInfo *ses, struct smb_hdr *in_buf,
 385                         struct mid_q_entry **ppmidQ)
 386 {
 387         if (ses->server->tcpStatus == CifsExiting) {
 388                 return -ENOENT;
 389         }
 390
 391         if (ses->server->tcpStatus == CifsNeedReconnect) {
 392                 cFYI(1, ("tcp session dead - return to caller to retry"));
 393                 return -EAGAIN;
 394         }
 395
 396         if (ses->status != CifsGood) {
 397                 /* check if SMB session is bad because we are setting it up */
 398                 if ((in_buf->Command != SMB_COM_SESSION_SETUP_ANDX) &&
 399                         (in_buf->Command != SMB_COM_NEGOTIATE))
 400                         return -EAGAIN;
 401                 /* else ok - we are setting up session */
 402         }
 403         *ppmidQ = AllocMidQEntry(in_buf, ses->server);
 404         if (*ppmidQ == NULL)
 405                 return -ENOMEM;
 406         return 0;
 407 }
 408
 409 static int wait_for_response(struct cifsSesInfo *ses,
 410                         struct mid_q_entry *midQ,
 411                         unsigned long timeout,
 412                         unsigned long time_to_wait)
 413 {
 414         unsigned long curr_timeout;
 415
 416         for (;;) {
 417                 curr_timeout = timeout + jiffies;
 418                 wait_event_timeout(ses->server->response_q,
 419                         midQ->midState != MID_REQUEST_SUBMITTED, timeout);
 420
 421                 if (time_after(jiffies, curr_timeout) &&
 422                         (midQ->midState == MID_REQUEST_SUBMITTED) &&
 423                         ((ses->server->tcpStatus == CifsGood) ||
 424                          (ses->server->tcpStatus == CifsNew))) {
 425
 426                         unsigned long lrt;
 427
 428                         /* We timed out. Is the server still
 429                            sending replies ? */
 430                         spin_lock(&GlobalMid_Lock);
 431                         lrt = ses->server->lstrp;
 432                         spin_unlock(&GlobalMid_Lock);
 433
 434                         /* Calculate time_to_wait past last receive time.
 435                          Although we prefer not to time out if the
 436                          server is still responding - we will time
 437                          out if the server takes more than 15 (or 45
 438                          or 180) seconds to respond to this request
 439                          and has not responded to any request from
 440                          other threads on the client within 10 seconds */
 441                         lrt += time_to_wait;
 442                         if (time_after(jiffies, lrt)) {
 443                                 /* No replies for time_to_wait. */
 444                                 cERROR(1, ("server not responding"));
 445                                 return -1;
 446                         }
 447                 } else {
 448                         return 0;
 449                 }
 450         }
 451 }
 452
 453
 454 /*
 455  *
 456  * Send an SMB Request.  No response info (other than return code)
 457  * needs to be parsed.
 458  *
 459  * flags indicate the type of request buffer and how long to wait
 460  * and whether to log NT STATUS code (error) before mapping it to POSIX error
 461  *
 462  */
 463 int
 464 SendReceiveNoRsp(const unsigned int xid, struct cifsSesInfo *ses,
 465                 struct smb_hdr *in_buf, int flags)
 466 {
 467         int rc;
 468         struct kvec iov[1];
 469         int resp_buf_type;
 470
 471         iov[0].iov_base = (char *)in_buf;
 472         iov[0].iov_len = in_buf->smb_buf_length + 4;
 473         flags |= CIFS_NO_RESP;
 474         rc = SendReceive2(xid, ses, iov, 1, &resp_buf_type, flags);
 475         cFYI(DBG2, ("SendRcvNoRsp flags %d rc %d", flags, rc));
 476
 477         return rc;
 478 }
 479
 480 int
 481 SendReceive2(const unsigned int xid, struct cifsSesInfo *ses,
 482              struct kvec *iov, int n_vec, int *pRespBufType /* ret */,
 483              const int flags)
 484 {
 485         int rc = 0;
 486         int long_op;
 487         unsigned int receive_len;
 488         unsigned long timeout;
 489         struct mid_q_entry *midQ;
 490         struct smb_hdr *in_buf = iov[0].iov_base;
 491
 492         long_op = flags & CIFS_TIMEOUT_MASK;
 493
 494         *pRespBufType = CIFS_NO_BUFFER;  /* no response buf yet */
 495
 496         if ((ses == NULL) || (ses->server == NULL)) {
 497                 cifs_small_buf_release(in_buf);
 498                 cERROR(1, ("Null session"));
 499                 return -EIO;
 500         }
 501
 502         if (ses->server->tcpStatus == CifsExiting) {
 503                 cifs_small_buf_release(in_buf);
 504                 return -ENOENT;
 505         }
 506
 507         /* Ensure that we do not send more than 50 overlapping requests
 508            to the same server. We may make this configurable later or
 509            use ses->maxReq */
 510
 511         rc = wait_for_free_request(ses, long_op);
 512         if (rc) {
 513                 cifs_small_buf_release(in_buf);
 514                 return rc;
 515         }
 516
 517         /* make sure that we sign in the same order that we send on this socket
 518            and avoid races inside tcp sendmsg code that could cause corruption
 519            of smb data */
 520
 521         mutex_lock(&ses->server->srv_mutex);
 522
 523         rc = allocate_mid(ses, in_buf, &midQ);
 524         if (rc) {
 525                 mutex_unlock(&ses->server->srv_mutex);
 526                 cifs_small_buf_release(in_buf);
 527                 /* Update # of requests on wire to server */
 528                 atomic_dec(&ses->server->inFlight);
 529                 wake_up(&ses->server->request_q);
 530                 return rc;
 531         }
 532         rc = cifs_sign_smb2(iov, n_vec, ses->server, &midQ->sequence_number);
 533         if (rc) {
 534                 mutex_unlock(&ses->server->srv_mutex);
 535                 cifs_small_buf_release(in_buf);
 536                 goto out;
 537         }
 538
 539         midQ->midState = MID_REQUEST_SUBMITTED;
 540 #ifdef CONFIG_CIFS_STATS2
 541         atomic_inc(&ses->server->inSend);
 542 #endif
 543         rc = smb_send2(ses->server, iov, n_vec,
 544                       (struct sockaddr *) &(ses->server->addr.sockAddr),
 545                        ses->server->noblocksnd);
 546 #ifdef CONFIG_CIFS_STATS2
 547         atomic_dec(&ses->server->inSend);
 548         midQ->when_sent = jiffies;
 549 #endif
 550
 551         mutex_unlock(&ses->server->srv_mutex);
 552         cifs_small_buf_release(in_buf);
 553
 554         if (rc < 0)
 555                 goto out;
 556
 557         if (long_op == CIFS_STD_OP)
 558                 timeout = 15 * HZ;
 559         else if (long_op == CIFS_VLONG_OP) /* e.g. slow writes past EOF */
 560                 timeout = 180 * HZ;
 561         else if (long_op == CIFS_LONG_OP)
 562                 timeout = 45 * HZ; /* should be greater than
 563                         servers oplock break timeout (about 43 seconds) */
 564         else if (long_op == CIFS_ASYNC_OP)
 565                 goto out;
 566         else if (long_op == CIFS_BLOCKING_OP)
 567                 timeout = 0x7FFFFFFF; /*  large, but not so large as to wrap */
 568         else {
 569                 cERROR(1, ("unknown timeout flag %d", long_op));
 570                 rc = -EIO;
 571                 goto out;
 572         }
 573
 574         /* wait for 15 seconds or until woken up due to response arriving or
 575            due to last connection to this server being unmounted */
 576         if (signal_pending(current)) {
 577                 /* if signal pending do not hold up user for full smb timeout
 578                 but we still give response a chance to complete */
 579                 timeout = 2 * HZ;
 580         }
 581
 582         /* No user interrupts in wait - wreaks havoc with performance */
 583         wait_for_response(ses, midQ, timeout, 10 * HZ);
 584
 585         spin_lock(&GlobalMid_Lock);
 586
 587         if (midQ->resp_buf == NULL) {
 588                 cERROR(1, ("No response to cmd %d mid %d",
 589                         midQ->command, midQ->mid));
 590                 if (midQ->midState == MID_REQUEST_SUBMITTED) {
 591                         if (ses->server->tcpStatus == CifsExiting)
 592                                 rc = -EHOSTDOWN;
 593                         else {
 594                                 ses->server->tcpStatus = CifsNeedReconnect;
 595                                 midQ->midState = MID_RETRY_NEEDED;
 596                         }
 597                 }
 598
 599                 if (rc != -EHOSTDOWN) {
 600                         if (midQ->midState == MID_RETRY_NEEDED) {
 601                                 rc = -EAGAIN;
 602                                 cFYI(1, ("marking request for retry"));
 603                         } else {
 604                                 rc = -EIO;
 605                         }
 606                 }
 607                 spin_unlock(&GlobalMid_Lock);
 608                 DeleteMidQEntry(midQ);
 609                 /* Update # of requests on wire to server */
 610                 atomic_dec(&ses->server->inFlight);
 611                 wake_up(&ses->server->request_q);
 612                 return rc;
 613         }
 614
 615         spin_unlock(&GlobalMid_Lock);
 616         receive_len = midQ->resp_buf->smb_buf_length;
 617
 618         if (receive_len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE) {
 619                 cERROR(1, ("Frame too large received.  Length: %d  Xid: %d",
 620                         receive_len, xid));
 621                 rc = -EIO;
 622                 goto out;
 623         }
 624
 625         /* rcvd frame is ok */
 626
 627         if (midQ->resp_buf &&
 628             (midQ->midState == MID_RESPONSE_RECEIVED)) {
 629
 630                 iov[0].iov_base = (char *)midQ->resp_buf;
 631                 if (midQ->largeBuf)
 632                         *pRespBufType = CIFS_LARGE_BUFFER;
 633                 else
 634                         *pRespBufType = CIFS_SMALL_BUFFER;
 635                 iov[0].iov_len = receive_len + 4;
 636
 637                 dump_smb(midQ->resp_buf, 80);
 638                 /* convert the length into a more usable form */
 639                 if ((receive_len > 24) &&
 640                     (ses->server->secMode & (SECMODE_SIGN_REQUIRED |
 641                                              SECMODE_SIGN_ENABLED))) {
 642                         rc = cifs_verify_signature(midQ->resp_buf,
 643                                                 &ses->server->mac_signing_key,
 644                                                 midQ->sequence_number+1);
 645                         if (rc) {
 646                                 cERROR(1, ("Unexpected SMB signature"));
 647                                 /* BB FIXME add code to kill session */
 648                         }
 649                 }
 650
 651                 /* BB special case reconnect tid and uid here? */
 652                 rc = map_smb_to_linux_error(midQ->resp_buf,
 653                                             flags & CIFS_LOG_ERROR);
 654
 655                 /* convert ByteCount if necessary */
 656                 if (receive_len >= sizeof(struct smb_hdr) - 4
 657                     /* do not count RFC1001 header */  +
 658                     (2 * midQ->resp_buf->WordCount) + 2 /* bcc */ )
 659                         BCC(midQ->resp_buf) =
 660                                 le16_to_cpu(BCC_LE(midQ->resp_buf));
 661                 if ((flags & CIFS_NO_RESP) == 0)
 662                         midQ->resp_buf = NULL;  /* mark it so buf will
 663                                                    not be freed by
 664                                                    DeleteMidQEntry */
 665         } else {
 666                 rc = -EIO;
 667                 cFYI(1, ("Bad MID state?"));
 668         }
 669
 670 out:
 671         DeleteMidQEntry(midQ);
 672         atomic_dec(&ses->server->inFlight);
 673         wake_up(&ses->server->request_q);
 674
 675         return rc;
 676 }
 677
 678 int
 679 SendReceive(const unsigned int xid, struct cifsSesInfo *ses,
 680             struct smb_hdr *in_buf, struct smb_hdr *out_buf,
 681             int *pbytes_returned, const int long_op)
 682 {
 683         int rc = 0;
 684         unsigned int receive_len;
 685         unsigned long timeout;
 686         struct mid_q_entry *midQ;
 687
 688         if (ses == NULL) {
 689                 cERROR(1, ("Null smb session"));
 690                 return -EIO;
 691         }
 692         if (ses->server == NULL) {
 693                 cERROR(1, ("Null tcp session"));
 694                 return -EIO;
 695         }
 696
 697         if (ses->server->tcpStatus == CifsExiting)
 698                 return -ENOENT;
 699
 700         /* Ensure that we do not send more than 50 overlapping requests
 701            to the same server. We may make this configurable later or
 702            use ses->maxReq */
 703
 704         if (in_buf->smb_buf_length > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) {
 705                 cERROR(1, ("Illegal length, greater than maximum frame, %d",
 706                            in_buf->smb_buf_length));
 707                 return -EIO;
 708         }
 709
 710         rc = wait_for_free_request(ses, long_op);
 711         if (rc)
 712                 return rc;
 713
 714         /* make sure that we sign in the same order that we send on this socket
 715            and avoid races inside tcp sendmsg code that could cause corruption
 716            of smb data */
 717
 718         mutex_lock(&ses->server->srv_mutex);
 719
 720         rc = allocate_mid(ses, in_buf, &midQ);
 721         if (rc) {
 722                 mutex_unlock(&ses->server->srv_mutex);
 723                 /* Update # of requests on wire to server */
 724                 atomic_dec(&ses->server->inFlight);
 725                 wake_up(&ses->server->request_q);
 726                 return rc;
 727         }
 728
 729         rc = cifs_sign_smb(in_buf, ses->server, &midQ->sequence_number);
 730         if (rc) {
 731                 mutex_unlock(&ses->server->srv_mutex);
 732                 goto out;
 733         }
 734
 735         midQ->midState = MID_REQUEST_SUBMITTED;
 736 #ifdef CONFIG_CIFS_STATS2
 737         atomic_inc(&ses->server->inSend);
 738 #endif
 739         rc = smb_send(ses->server->ssocket, in_buf, in_buf->smb_buf_length,
 740                       (struct sockaddr *) &(ses->server->addr.sockAddr),
 741                       ses->server->noblocksnd);
 742 #ifdef CONFIG_CIFS_STATS2
 743         atomic_dec(&ses->server->inSend);
 744         midQ->when_sent = jiffies;
 745 #endif
 746         mutex_unlock(&ses->server->srv_mutex);
 747
 748         if (rc < 0)
 749                 goto out;
 750
 751         if (long_op == CIFS_STD_OP)
 752                 timeout = 15 * HZ;
 753         /* wait for 15 seconds or until woken up due to response arriving or
 754            due to last connection to this server being unmounted */
 755         else if (long_op == CIFS_ASYNC_OP)
 756                 goto out;
 757         else if (long_op == CIFS_VLONG_OP) /* writes past EOF can be slow */
 758                 timeout = 180 * HZ;
 759         else if (long_op == CIFS_LONG_OP)
 760                 timeout = 45 * HZ; /* should be greater than
 761                         servers oplock break timeout (about 43 seconds) */
 762         else if (long_op == CIFS_BLOCKING_OP)
 763                 timeout = 0x7FFFFFFF; /* large but no so large as to wrap */
 764         else {
 765                 cERROR(1, ("unknown timeout flag %d", long_op));
 766                 rc = -EIO;
 767                 goto out;
 768         }
 769
 770         if (signal_pending(current)) {
 771                 /* if signal pending do not hold up user for full smb timeout
 772                 but we still give response a chance to complete */
 773                 timeout = 2 * HZ;
 774         }
 775
 776         /* No user interrupts in wait - wreaks havoc with performance */
 777         wait_for_response(ses, midQ, timeout, 10 * HZ);
 778
 779         spin_lock(&GlobalMid_Lock);
 780         if (midQ->resp_buf == NULL) {
 781                 cERROR(1, ("No response for cmd %d mid %d",
 782                           midQ->command, midQ->mid));
 783                 if (midQ->midState == MID_REQUEST_SUBMITTED) {
 784                         if (ses->server->tcpStatus == CifsExiting)
 785                                 rc = -EHOSTDOWN;
 786                         else {
 787                                 ses->server->tcpStatus = CifsNeedReconnect;
 788                                 midQ->midState = MID_RETRY_NEEDED;
 789                         }
 790                 }
 791
 792                 if (rc != -EHOSTDOWN) {
 793                         if (midQ->midState == MID_RETRY_NEEDED) {
 794                                 rc = -EAGAIN;
 795                                 cFYI(1, ("marking request for retry"));
 796                         } else {
 797                                 rc = -EIO;
 798                         }
 799                 }
 800                 spin_unlock(&GlobalMid_Lock);
 801                 DeleteMidQEntry(midQ);
 802                 /* Update # of requests on wire to server */
 803                 atomic_dec(&ses->server->inFlight);
 804                 wake_up(&ses->server->request_q);
 805                 return rc;
 806         }
 807
 808         spin_unlock(&GlobalMid_Lock);
 809         receive_len = midQ->resp_buf->smb_buf_length;
 810
 811         if (receive_len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE) {
 812                 cERROR(1, ("Frame too large received.  Length: %d  Xid: %d",
 813                         receive_len, xid));
 814                 rc = -EIO;
 815                 goto out;
 816         }
 817
 818         /* rcvd frame is ok */
 819
 820         if (midQ->resp_buf && out_buf
 821             && (midQ->midState == MID_RESPONSE_RECEIVED)) {
 822                 out_buf->smb_buf_length = receive_len;
 823                 memcpy((char *)out_buf + 4,
 824                        (char *)midQ->resp_buf + 4,
 825                        receive_len);
 826
 827                 dump_smb(out_buf, 92);
 828                 /* convert the length into a more usable form */
 829                 if ((receive_len > 24) &&
 830                     (ses->server->secMode & (SECMODE_SIGN_REQUIRED |
 831                                              SECMODE_SIGN_ENABLED))) {
 832                         rc = cifs_verify_signature(out_buf,
 833                                                 &ses->server->mac_signing_key,
 834                                                 midQ->sequence_number+1);
 835                         if (rc) {
 836                                 cERROR(1, ("Unexpected SMB signature"));
 837                                 /* BB FIXME add code to kill session */
 838                         }
 839                 }
 840
 841                 *pbytes_returned = out_buf->smb_buf_length;
 842
 843                 /* BB special case reconnect tid and uid here? */
 844                 rc = map_smb_to_linux_error(out_buf, 0 /* no log */ );
 845
 846                 /* convert ByteCount if necessary */
 847                 if (receive_len >= sizeof(struct smb_hdr) - 4
 848                     /* do not count RFC1001 header */  +
 849                     (2 * out_buf->WordCount) + 2 /* bcc */ )
 850                         BCC(out_buf) = le16_to_cpu(BCC_LE(out_buf));
 851         } else {
 852                 rc = -EIO;
 853                 cERROR(1, ("Bad MID state?"));
 854         }
 855
 856 out:
 857         DeleteMidQEntry(midQ);
 858         atomic_dec(&ses->server->inFlight);
 859         wake_up(&ses->server->request_q);
 860
 861         return rc;
 862 }
 863
 864 /* Send an NT_CANCEL SMB to cause the POSIX blocking lock to return. */
 865
 866 static int
 867 send_nt_cancel(struct cifsTconInfo *tcon, struct smb_hdr *in_buf,
 868                 struct mid_q_entry *midQ)
 869 {
 870         int rc = 0;
 871         struct cifsSesInfo *ses = tcon->ses;
 872         __u16 mid = in_buf->Mid;
 873
 874         header_assemble(in_buf, SMB_COM_NT_CANCEL, tcon, 0);
 875         in_buf->Mid = mid;
 876         mutex_lock(&ses->server->srv_mutex);
 877         rc = cifs_sign_smb(in_buf, ses->server, &midQ->sequence_number);
 878         if (rc) {
 879                 mutex_unlock(&ses->server->srv_mutex);
 880                 return rc;
 881         }
 882         rc = smb_send(ses->server->ssocket, in_buf, in_buf->smb_buf_length,
 883               (struct sockaddr *) &(ses->server->addr.sockAddr),
 884               ses->server->noblocksnd);
 885         mutex_unlock(&ses->server->srv_mutex);
 886         return rc;
 887 }
 888
 889 /* We send a LOCKINGX_CANCEL_LOCK to cause the Windows
 890    blocking lock to return. */
 891
 892 static int
 893 send_lock_cancel(const unsigned int xid, struct cifsTconInfo *tcon,
 894                         struct smb_hdr *in_buf,
 895                         struct smb_hdr *out_buf)
 896 {
 897         int bytes_returned;
 898         struct cifsSesInfo *ses = tcon->ses;
 899         LOCK_REQ *pSMB = (LOCK_REQ *)in_buf;
 900
 901         /* We just modify the current in_buf to change
 902            the type of lock from LOCKING_ANDX_SHARED_LOCK
 903            or LOCKING_ANDX_EXCLUSIVE_LOCK to
 904            LOCKING_ANDX_CANCEL_LOCK. */
 905
 906         pSMB->LockType = LOCKING_ANDX_CANCEL_LOCK|LOCKING_ANDX_LARGE_FILES;
 907         pSMB->Timeout = 0;
 908         pSMB->hdr.Mid = GetNextMid(ses->server);
 909
 910         return SendReceive(xid, ses, in_buf, out_buf,
 911                         &bytes_returned, CIFS_STD_OP);
 912 }
 913
 914 int
 915 SendReceiveBlockingLock(const unsigned int xid, struct cifsTconInfo *tcon,
 916             struct smb_hdr *in_buf, struct smb_hdr *out_buf,
 917             int *pbytes_returned)
 918 {
 919         int rc = 0;
 920         int rstart = 0;
 921         unsigned int receive_len;
 922         struct mid_q_entry *midQ;
 923         struct cifsSesInfo *ses;
 924
 925         if (tcon == NULL || tcon->ses == NULL) {
 926                 cERROR(1, ("Null smb session"));
 927                 return -EIO;
 928         }
 929         ses = tcon->ses;
 930
 931         if (ses->server == NULL) {
 932                 cERROR(1, ("Null tcp session"));
 933                 return -EIO;
 934         }
 935
 936         if (ses->server->tcpStatus == CifsExiting)
 937                 return -ENOENT;
 938
 939         /* Ensure that we do not send more than 50 overlapping requests
 940            to the same server. We may make this configurable later or
 941            use ses->maxReq */
 942
 943         if (in_buf->smb_buf_length > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) {
 944                 cERROR(1, ("Illegal length, greater than maximum frame, %d",
 945                            in_buf->smb_buf_length));
 946                 return -EIO;
 947         }
 948
 949         rc = wait_for_free_request(ses, CIFS_BLOCKING_OP);
 950         if (rc)
 951                 return rc;
 952
 953         /* make sure that we sign in the same order that we send on this socket
 954            and avoid races inside tcp sendmsg code that could cause corruption
 955            of smb data */
 956
 957         mutex_lock(&ses->server->srv_mutex);
 958
 959         rc = allocate_mid(ses, in_buf, &midQ);
 960         if (rc) {
 961                 mutex_unlock(&ses->server->srv_mutex);
 962                 return rc;
 963         }
 964
 965         rc = cifs_sign_smb(in_buf, ses->server, &midQ->sequence_number);
 966         if (rc) {
 967                 DeleteMidQEntry(midQ);
 968                 mutex_unlock(&ses->server->srv_mutex);
 969                 return rc;
 970         }
 971
 972         midQ->midState = MID_REQUEST_SUBMITTED;
 973 #ifdef CONFIG_CIFS_STATS2
 974         atomic_inc(&ses->server->inSend);
 975 #endif
 976         rc = smb_send(ses->server->ssocket, in_buf, in_buf->smb_buf_length,
 977                       (struct sockaddr *) &(ses->server->addr.sockAddr),
 978                       ses->server->noblocksnd);
 979 #ifdef CONFIG_CIFS_STATS2
 980         atomic_dec(&ses->server->inSend);
 981         midQ->when_sent = jiffies;
 982 #endif
 983         mutex_unlock(&ses->server->srv_mutex);
 984
 985         if (rc < 0) {
 986                 DeleteMidQEntry(midQ);
 987                 return rc;
 988         }
 989
 990         /* Wait for a reply - allow signals to interrupt. */
 991         rc = wait_event_interruptible(ses->server->response_q,
 992                 (!(midQ->midState == MID_REQUEST_SUBMITTED)) ||
 993                 ((ses->server->tcpStatus != CifsGood) &&
 994                  (ses->server->tcpStatus != CifsNew)));
 995
 996         /* Were we interrupted by a signal ? */
 997         if ((rc == -ERESTARTSYS) &&
 998                 (midQ->midState == MID_REQUEST_SUBMITTED) &&
 999                 ((ses->server->tcpStatus == CifsGood) ||
1000                  (ses->server->tcpStatus == CifsNew))) {
1001
1002                 if (in_buf->Command == SMB_COM_TRANSACTION2) {
1003                         /* POSIX lock. We send a NT_CANCEL SMB to cause the
1004                            blocking lock to return. */
1005
1006                         rc = send_nt_cancel(tcon, in_buf, midQ);
1007                         if (rc) {
1008                                 DeleteMidQEntry(midQ);
1009                                 return rc;
1010                         }
1011                 } else {
1012                         /* Windows lock. We send a LOCKINGX_CANCEL_LOCK
1013                            to cause the blocking lock to return. */
1014
1015                         rc = send_lock_cancel(xid, tcon, in_buf, out_buf);
1016
1017                         /* If we get -ENOLCK back the lock may have
1018                            already been removed. Don't exit in this case. */
1019                         if (rc && rc != -ENOLCK) {
1020                                 DeleteMidQEntry(midQ);
1021                                 return rc;
1022                         }
1023                 }
1024
1025                 /* Wait 5 seconds for the response. */
1026                 if (wait_for_response(ses, midQ, 5 * HZ, 5 * HZ) == 0) {
1027                         /* We got the response - restart system call. */
1028                         rstart = 1;
1029                 }
1030         }
1031
1032         spin_lock(&GlobalMid_Lock);
1033         if (midQ->resp_buf) {
1034                 spin_unlock(&GlobalMid_Lock);
1035                 receive_len = midQ->resp_buf->smb_buf_length;
1036         } else {
1037                 cERROR(1, ("No response for cmd %d mid %d",
1038                           midQ->command, midQ->mid));
1039                 if (midQ->midState == MID_REQUEST_SUBMITTED) {
1040                         if (ses->server->tcpStatus == CifsExiting)
1041                                 rc = -EHOSTDOWN;
1042                         else {
1043                                 ses->server->tcpStatus = CifsNeedReconnect;
1044                                 midQ->midState = MID_RETRY_NEEDED;
1045                         }
1046                 }
1047
1048                 if (rc != -EHOSTDOWN) {
1049                         if (midQ->midState == MID_RETRY_NEEDED) {
1050                                 rc = -EAGAIN;
1051                                 cFYI(1, ("marking request for retry"));
1052                         } else {
1053                                 rc = -EIO;
1054                         }
1055                 }
1056                 spin_unlock(&GlobalMid_Lock);
1057                 DeleteMidQEntry(midQ);
1058                 return rc;
1059         }
1060
1061         if (receive_len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE) {
1062                 cERROR(1, ("Frame too large received.  Length: %d  Xid: %d",
1063                         receive_len, xid));
1064                 rc = -EIO;
1065                 goto out;
1066         }
1067
1068         /* rcvd frame is ok */
1069
1070         if ((out_buf == NULL) || (midQ->midState != MID_RESPONSE_RECEIVED)) {
1071                 rc = -EIO;
1072                 cERROR(1, ("Bad MID state?"));
1073                 goto out;
1074         }
1075
1076         out_buf->smb_buf_length = receive_len;
1077         memcpy((char *)out_buf + 4,
1078                (char *)midQ->resp_buf + 4,
1079                receive_len);
1080
1081         dump_smb(out_buf, 92);
1082         /* convert the length into a more usable form */
1083         if ((receive_len > 24) &&
1084             (ses->server->secMode & (SECMODE_SIGN_REQUIRED |
1085                                      SECMODE_SIGN_ENABLED))) {
1086                 rc = cifs_verify_signature(out_buf,
1087                                            &ses->server->mac_signing_key,
1088                                            midQ->sequence_number+1);
1089                 if (rc) {
1090                         cERROR(1, ("Unexpected SMB signature"));
1091                         /* BB FIXME add code to kill session */
1092                 }
1093         }
1094
1095         *pbytes_returned = out_buf->smb_buf_length;
1096
1097         /* BB special case reconnect tid and uid here? */
1098         rc = map_smb_to_linux_error(out_buf, 0 /* no log */ );
1099
1100         /* convert ByteCount if necessary */
1101         if (receive_len >= sizeof(struct smb_hdr) - 4
1102             /* do not count RFC1001 header */  +
1103             (2 * out_buf->WordCount) + 2 /* bcc */ )
1104                 BCC(out_buf) = le16_to_cpu(BCC_LE(out_buf));
1105
1106 out:
1107         DeleteMidQEntry(midQ);
1108         if (rstart && rc == -EACCES)
1109                 return -ERESTARTSYS;
1110         return rc;
1111 }