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 static int
 107 smb_sendv(struct TCP_Server_Info *server, struct kvec *iov, int n_vec)
 108 {
 109         int rc = 0;
 110         int i = 0;
 111         struct msghdr smb_msg;
 112         struct smb_hdr *smb_buffer = iov[0].iov_base;
 113         unsigned int len = iov[0].iov_len;
 114         unsigned int total_len;
 115         int first_vec = 0;
 116         unsigned int smb_buf_length = smb_buffer->smb_buf_length;
 117         struct socket *ssocket = server->ssocket;
 118
 119         if (ssocket == NULL)
 120                 return -ENOTSOCK; /* BB eventually add reconnect code here */
 121
 122         smb_msg.msg_name = (struct sockaddr *) &server->addr.sockAddr;
 123         smb_msg.msg_namelen = sizeof(struct sockaddr);
 124         smb_msg.msg_control = NULL;
 125         smb_msg.msg_controllen = 0;
 126         if (server->noblocksnd)
 127                 smb_msg.msg_flags = MSG_DONTWAIT + MSG_NOSIGNAL;
 128         else
 129                 smb_msg.msg_flags = MSG_NOSIGNAL;
 130
 131         /* smb header is converted in header_assemble. bcc and rest of SMB word
 132            area, and byte area if necessary, is converted to littleendian in
 133            cifssmb.c and RFC1001 len is converted to bigendian in smb_send
 134            Flags2 is converted in SendReceive */
 135
 136
 137         total_len = 0;
 138         for (i = 0; i < n_vec; i++)
 139                 total_len += iov[i].iov_len;
 140
 141         smb_buffer->smb_buf_length = cpu_to_be32(smb_buffer->smb_buf_length);
 142         cFYI(1, ("Sending smb:  total_len %d", total_len));
 143         dump_smb(smb_buffer, len);
 144
 145         i = 0;
 146         while (total_len) {
 147                 rc = kernel_sendmsg(ssocket, &smb_msg, &iov[first_vec],
 148                                     n_vec - first_vec, total_len);
 149                 if ((rc == -ENOSPC) || (rc == -EAGAIN)) {
 150                         i++;
 151                         /* if blocking send we try 3 times, since each can block
 152                            for 5 seconds. For nonblocking  we have to try more
 153                            but wait increasing amounts of time allowing time for
 154                            socket to clear.  The overall time we wait in either
 155                            case to send on the socket is about 15 seconds.
 156                            Similarly we wait for 15 seconds for
 157                            a response from the server in SendReceive[2]
 158                            for the server to send a response back for
 159                            most types of requests (except SMB Write
 160                            past end of file which can be slow, and
 161                            blocking lock operations). NFS waits slightly longer
 162                            than CIFS, but this can make it take longer for
 163                            nonresponsive servers to be detected and 15 seconds
 164                            is more than enough time for modern networks to
 165                            send a packet.  In most cases if we fail to send
 166                            after the retries we will kill the socket and
 167                            reconnect which may clear the network problem.
 168                         */
 169                         if ((i >= 14) || (!server->noblocksnd && (i > 2))) {
 170                                 cERROR(1,
 171                                    ("sends on sock %p stuck for 15 seconds",
 172                                     ssocket));
 173                                 rc = -EAGAIN;
 174                                 break;
 175                         }
 176                         msleep(1 << i);
 177                         continue;
 178                 }
 179                 if (rc < 0)
 180                         break;
 181
 182                 if (rc == total_len) {
 183                         total_len = 0;
 184                         break;
 185                 } else if (rc > total_len) {
 186                         cERROR(1, ("sent %d requested %d", rc, total_len));
 187                         break;
 188                 }
 189                 if (rc == 0) {
 190                         /* should never happen, letting socket clear before
 191                            retrying is our only obvious option here */
 192                         cERROR(1, ("tcp sent no data"));
 193                         msleep(500);
 194                         continue;
 195                 }
 196                 total_len -= rc;
 197                 /* the line below resets i */
 198                 for (i = first_vec; i < n_vec; i++) {
 199                         if (iov[i].iov_len) {
 200                                 if (rc > iov[i].iov_len) {
 201                                         rc -= iov[i].iov_len;
 202                                         iov[i].iov_len = 0;
 203                                 } else {
 204                                         iov[i].iov_base += rc;
 205                                         iov[i].iov_len -= rc;
 206                                         first_vec = i;
 207                                         break;
 208                                 }
 209                         }
 210                 }
 211                 i = 0; /* in case we get ENOSPC on the next send */
 212         }
 213
 214         if ((total_len > 0) && (total_len != smb_buf_length + 4)) {
 215                 cFYI(1, ("partial send (%d remaining), terminating session",
 216                         total_len));
 217                 /* If we have only sent part of an SMB then the next SMB
 218                    could be taken as the remainder of this one.  We need
 219                    to kill the socket so the server throws away the partial
 220                    SMB */
 221                 server->tcpStatus = CifsNeedReconnect;
 222         }
 223
 224         if (rc < 0) {
 225                 cERROR(1, ("Error %d sending data on socket to server", rc));
 226         } else
 227                 rc = 0;
 228
 229         /* Don't want to modify the buffer as a
 230            side effect of this call. */
 231         smb_buffer->smb_buf_length = smb_buf_length;
 232
 233         return rc;
 234 }
 235
 236 int
 237 smb_send(struct TCP_Server_Info *server, struct smb_hdr *smb_buffer,
 238          unsigned int smb_buf_length)
 239 {
 240         struct kvec iov;
 241
 242         iov.iov_base = smb_buffer;
 243         iov.iov_len = smb_buf_length + 4;
 244
 245         return smb_sendv(server, &iov, 1);
 246 }
 247
 248 static int wait_for_free_request(struct cifsSesInfo *ses, const int long_op)
 249 {
 250         if (long_op == CIFS_ASYNC_OP) {
 251                 /* oplock breaks must not be held up */
 252                 atomic_inc(&ses->server->inFlight);
 253                 return 0;
 254         }
 255
 256         spin_lock(&GlobalMid_Lock);
 257         while (1) {
 258                 if (atomic_read(&ses->server->inFlight) >=
 259                                 cifs_max_pending){
 260                         spin_unlock(&GlobalMid_Lock);
 261 #ifdef CONFIG_CIFS_STATS2
 262                         atomic_inc(&ses->server->num_waiters);
 263 #endif
 264                         wait_event(ses->server->request_q,
 265                                    atomic_read(&ses->server->inFlight)
 266                                      < cifs_max_pending);
 267 #ifdef CONFIG_CIFS_STATS2
 268                         atomic_dec(&ses->server->num_waiters);
 269 #endif
 270                         spin_lock(&GlobalMid_Lock);
 271                 } else {
 272                         if (ses->server->tcpStatus == CifsExiting) {
 273                                 spin_unlock(&GlobalMid_Lock);
 274                                 return -ENOENT;
 275                         }
 276
 277                         /* can not count locking commands against total
 278                            as they are allowed to block on server */
 279
 280                         /* update # of requests on the wire to server */
 281                         if (long_op != CIFS_BLOCKING_OP)
 282                                 atomic_inc(&ses->server->inFlight);
 283                         spin_unlock(&GlobalMid_Lock);
 284                         break;
 285                 }
 286         }
 287         return 0;
 288 }
 289
 290 static int allocate_mid(struct cifsSesInfo *ses, struct smb_hdr *in_buf,
 291                         struct mid_q_entry **ppmidQ)
 292 {
 293         if (ses->server->tcpStatus == CifsExiting) {
 294                 return -ENOENT;
 295         }
 296
 297         if (ses->server->tcpStatus == CifsNeedReconnect) {
 298                 cFYI(1, ("tcp session dead - return to caller to retry"));
 299                 return -EAGAIN;
 300         }
 301
 302         if (ses->status != CifsGood) {
 303                 /* check if SMB session is bad because we are setting it up */
 304                 if ((in_buf->Command != SMB_COM_SESSION_SETUP_ANDX) &&
 305                         (in_buf->Command != SMB_COM_NEGOTIATE))
 306                         return -EAGAIN;
 307                 /* else ok - we are setting up session */
 308         }
 309         *ppmidQ = AllocMidQEntry(in_buf, ses->server);
 310         if (*ppmidQ == NULL)
 311                 return -ENOMEM;
 312         return 0;
 313 }
 314
 315 static int wait_for_response(struct cifsSesInfo *ses,
 316                         struct mid_q_entry *midQ,
 317                         unsigned long timeout,
 318                         unsigned long time_to_wait)
 319 {
 320         unsigned long curr_timeout;
 321
 322         for (;;) {
 323                 curr_timeout = timeout + jiffies;
 324                 wait_event_timeout(ses->server->response_q,
 325                         midQ->midState != MID_REQUEST_SUBMITTED, timeout);
 326
 327                 if (time_after(jiffies, curr_timeout) &&
 328                         (midQ->midState == MID_REQUEST_SUBMITTED) &&
 329                         ((ses->server->tcpStatus == CifsGood) ||
 330                          (ses->server->tcpStatus == CifsNew))) {
 331
 332                         unsigned long lrt;
 333
 334                         /* We timed out. Is the server still
 335                            sending replies ? */
 336                         spin_lock(&GlobalMid_Lock);
 337                         lrt = ses->server->lstrp;
 338                         spin_unlock(&GlobalMid_Lock);
 339
 340                         /* Calculate time_to_wait past last receive time.
 341                          Although we prefer not to time out if the
 342                          server is still responding - we will time
 343                          out if the server takes more than 15 (or 45
 344                          or 180) seconds to respond to this request
 345                          and has not responded to any request from
 346                          other threads on the client within 10 seconds */
 347                         lrt += time_to_wait;
 348                         if (time_after(jiffies, lrt)) {
 349                                 /* No replies for time_to_wait. */
 350                                 cERROR(1, ("server not responding"));
 351                                 return -1;
 352                         }
 353                 } else {
 354                         return 0;
 355                 }
 356         }
 357 }
 358
 359
 360 /*
 361  *
 362  * Send an SMB Request.  No response info (other than return code)
 363  * needs to be parsed.
 364  *
 365  * flags indicate the type of request buffer and how long to wait
 366  * and whether to log NT STATUS code (error) before mapping it to POSIX error
 367  *
 368  */
 369 int
 370 SendReceiveNoRsp(const unsigned int xid, struct cifsSesInfo *ses,
 371                 struct smb_hdr *in_buf, int flags)
 372 {
 373         int rc;
 374         struct kvec iov[1];
 375         int resp_buf_type;
 376
 377         iov[0].iov_base = (char *)in_buf;
 378         iov[0].iov_len = in_buf->smb_buf_length + 4;
 379         flags |= CIFS_NO_RESP;
 380         rc = SendReceive2(xid, ses, iov, 1, &resp_buf_type, flags);
 381         cFYI(DBG2, ("SendRcvNoRsp flags %d rc %d", flags, rc));
 382
 383         return rc;
 384 }
 385
 386 int
 387 SendReceive2(const unsigned int xid, struct cifsSesInfo *ses,
 388              struct kvec *iov, int n_vec, int *pRespBufType /* ret */,
 389              const int flags)
 390 {
 391         int rc = 0;
 392         int long_op;
 393         unsigned int receive_len;
 394         unsigned long timeout;
 395         struct mid_q_entry *midQ;
 396         struct smb_hdr *in_buf = iov[0].iov_base;
 397
 398         long_op = flags & CIFS_TIMEOUT_MASK;
 399
 400         *pRespBufType = CIFS_NO_BUFFER;  /* no response buf yet */
 401
 402         if ((ses == NULL) || (ses->server == NULL)) {
 403                 cifs_small_buf_release(in_buf);
 404                 cERROR(1, ("Null session"));
 405                 return -EIO;
 406         }
 407
 408         if (ses->server->tcpStatus == CifsExiting) {
 409                 cifs_small_buf_release(in_buf);
 410                 return -ENOENT;
 411         }
 412
 413         /* Ensure that we do not send more than 50 overlapping requests
 414            to the same server. We may make this configurable later or
 415            use ses->maxReq */
 416
 417         rc = wait_for_free_request(ses, long_op);
 418         if (rc) {
 419                 cifs_small_buf_release(in_buf);
 420                 return rc;
 421         }
 422
 423         /* make sure that we sign in the same order that we send on this socket
 424            and avoid races inside tcp sendmsg code that could cause corruption
 425            of smb data */
 426
 427         mutex_lock(&ses->server->srv_mutex);
 428
 429         rc = allocate_mid(ses, in_buf, &midQ);
 430         if (rc) {
 431                 mutex_unlock(&ses->server->srv_mutex);
 432                 cifs_small_buf_release(in_buf);
 433                 /* Update # of requests on wire to server */
 434                 atomic_dec(&ses->server->inFlight);
 435                 wake_up(&ses->server->request_q);
 436                 return rc;
 437         }
 438         rc = cifs_sign_smb2(iov, n_vec, ses->server, &midQ->sequence_number);
 439         if (rc) {
 440                 mutex_unlock(&ses->server->srv_mutex);
 441                 cifs_small_buf_release(in_buf);
 442                 goto out;
 443         }
 444
 445         midQ->midState = MID_REQUEST_SUBMITTED;
 446 #ifdef CONFIG_CIFS_STATS2
 447         atomic_inc(&ses->server->inSend);
 448 #endif
 449         rc = smb_sendv(ses->server, iov, n_vec);
 450 #ifdef CONFIG_CIFS_STATS2
 451         atomic_dec(&ses->server->inSend);
 452         midQ->when_sent = jiffies;
 453 #endif
 454
 455         mutex_unlock(&ses->server->srv_mutex);
 456         cifs_small_buf_release(in_buf);
 457
 458         if (rc < 0)
 459                 goto out;
 460
 461         if (long_op == CIFS_STD_OP)
 462                 timeout = 15 * HZ;
 463         else if (long_op == CIFS_VLONG_OP) /* e.g. slow writes past EOF */
 464                 timeout = 180 * HZ;
 465         else if (long_op == CIFS_LONG_OP)
 466                 timeout = 45 * HZ; /* should be greater than
 467                         servers oplock break timeout (about 43 seconds) */
 468         else if (long_op == CIFS_ASYNC_OP)
 469                 goto out;
 470         else if (long_op == CIFS_BLOCKING_OP)
 471                 timeout = 0x7FFFFFFF; /*  large, but not so large as to wrap */
 472         else {
 473                 cERROR(1, ("unknown timeout flag %d", long_op));
 474                 rc = -EIO;
 475                 goto out;
 476         }
 477
 478         /* wait for 15 seconds or until woken up due to response arriving or
 479            due to last connection to this server being unmounted */
 480         if (signal_pending(current)) {
 481                 /* if signal pending do not hold up user for full smb timeout
 482                 but we still give response a chance to complete */
 483                 timeout = 2 * HZ;
 484         }
 485
 486         /* No user interrupts in wait - wreaks havoc with performance */
 487         wait_for_response(ses, midQ, timeout, 10 * HZ);
 488
 489         spin_lock(&GlobalMid_Lock);
 490
 491         if (midQ->resp_buf == NULL) {
 492                 cERROR(1, ("No response to cmd %d mid %d",
 493                         midQ->command, midQ->mid));
 494                 if (midQ->midState == MID_REQUEST_SUBMITTED) {
 495                         if (ses->server->tcpStatus == CifsExiting)
 496                                 rc = -EHOSTDOWN;
 497                         else {
 498                                 ses->server->tcpStatus = CifsNeedReconnect;
 499                                 midQ->midState = MID_RETRY_NEEDED;
 500                         }
 501                 }
 502
 503                 if (rc != -EHOSTDOWN) {
 504                         if (midQ->midState == MID_RETRY_NEEDED) {
 505                                 rc = -EAGAIN;
 506                                 cFYI(1, ("marking request for retry"));
 507                         } else {
 508                                 rc = -EIO;
 509                         }
 510                 }
 511                 spin_unlock(&GlobalMid_Lock);
 512                 DeleteMidQEntry(midQ);
 513                 /* Update # of requests on wire to server */
 514                 atomic_dec(&ses->server->inFlight);
 515                 wake_up(&ses->server->request_q);
 516                 return rc;
 517         }
 518
 519         spin_unlock(&GlobalMid_Lock);
 520         receive_len = midQ->resp_buf->smb_buf_length;
 521
 522         if (receive_len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE) {
 523                 cERROR(1, ("Frame too large received.  Length: %d  Xid: %d",
 524                         receive_len, xid));
 525                 rc = -EIO;
 526                 goto out;
 527         }
 528
 529         /* rcvd frame is ok */
 530
 531         if (midQ->resp_buf &&
 532             (midQ->midState == MID_RESPONSE_RECEIVED)) {
 533
 534                 iov[0].iov_base = (char *)midQ->resp_buf;
 535                 if (midQ->largeBuf)
 536                         *pRespBufType = CIFS_LARGE_BUFFER;
 537                 else
 538                         *pRespBufType = CIFS_SMALL_BUFFER;
 539                 iov[0].iov_len = receive_len + 4;
 540
 541                 dump_smb(midQ->resp_buf, 80);
 542                 /* convert the length into a more usable form */
 543                 if ((receive_len > 24) &&
 544                     (ses->server->secMode & (SECMODE_SIGN_REQUIRED |
 545                                              SECMODE_SIGN_ENABLED))) {
 546                         rc = cifs_verify_signature(midQ->resp_buf,
 547                                                 &ses->server->mac_signing_key,
 548                                                 midQ->sequence_number+1);
 549                         if (rc) {
 550                                 cERROR(1, ("Unexpected SMB signature"));
 551                                 /* BB FIXME add code to kill session */
 552                         }
 553                 }
 554
 555                 /* BB special case reconnect tid and uid here? */
 556                 rc = map_smb_to_linux_error(midQ->resp_buf,
 557                                             flags & CIFS_LOG_ERROR);
 558
 559                 /* convert ByteCount if necessary */
 560                 if (receive_len >= sizeof(struct smb_hdr) - 4
 561                     /* do not count RFC1001 header */  +
 562                     (2 * midQ->resp_buf->WordCount) + 2 /* bcc */ )
 563                         BCC(midQ->resp_buf) =
 564                                 le16_to_cpu(BCC_LE(midQ->resp_buf));
 565                 if ((flags & CIFS_NO_RESP) == 0)
 566                         midQ->resp_buf = NULL;  /* mark it so buf will
 567                                                    not be freed by
 568                                                    DeleteMidQEntry */
 569         } else {
 570                 rc = -EIO;
 571                 cFYI(1, ("Bad MID state?"));
 572         }
 573
 574 out:
 575         DeleteMidQEntry(midQ);
 576         atomic_dec(&ses->server->inFlight);
 577         wake_up(&ses->server->request_q);
 578
 579         return rc;
 580 }
 581
 582 int
 583 SendReceive(const unsigned int xid, struct cifsSesInfo *ses,
 584             struct smb_hdr *in_buf, struct smb_hdr *out_buf,
 585             int *pbytes_returned, const int long_op)
 586 {
 587         int rc = 0;
 588         unsigned int receive_len;
 589         unsigned long timeout;
 590         struct mid_q_entry *midQ;
 591
 592         if (ses == NULL) {
 593                 cERROR(1, ("Null smb session"));
 594                 return -EIO;
 595         }
 596         if (ses->server == NULL) {
 597                 cERROR(1, ("Null tcp session"));
 598                 return -EIO;
 599         }
 600
 601         if (ses->server->tcpStatus == CifsExiting)
 602                 return -ENOENT;
 603
 604         /* Ensure that we do not send more than 50 overlapping requests
 605            to the same server. We may make this configurable later or
 606            use ses->maxReq */
 607
 608         if (in_buf->smb_buf_length > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) {
 609                 cERROR(1, ("Illegal length, greater than maximum frame, %d",
 610                            in_buf->smb_buf_length));
 611                 return -EIO;
 612         }
 613
 614         rc = wait_for_free_request(ses, long_op);
 615         if (rc)
 616                 return rc;
 617
 618         /* make sure that we sign in the same order that we send on this socket
 619            and avoid races inside tcp sendmsg code that could cause corruption
 620            of smb data */
 621
 622         mutex_lock(&ses->server->srv_mutex);
 623
 624         rc = allocate_mid(ses, in_buf, &midQ);
 625         if (rc) {
 626                 mutex_unlock(&ses->server->srv_mutex);
 627                 /* Update # of requests on wire to server */
 628                 atomic_dec(&ses->server->inFlight);
 629                 wake_up(&ses->server->request_q);
 630                 return rc;
 631         }
 632
 633         rc = cifs_sign_smb(in_buf, ses->server, &midQ->sequence_number);
 634         if (rc) {
 635                 mutex_unlock(&ses->server->srv_mutex);
 636                 goto out;
 637         }
 638
 639         midQ->midState = MID_REQUEST_SUBMITTED;
 640 #ifdef CONFIG_CIFS_STATS2
 641         atomic_inc(&ses->server->inSend);
 642 #endif
 643         rc = smb_send(ses->server, in_buf, in_buf->smb_buf_length);
 644 #ifdef CONFIG_CIFS_STATS2
 645         atomic_dec(&ses->server->inSend);
 646         midQ->when_sent = jiffies;
 647 #endif
 648         mutex_unlock(&ses->server->srv_mutex);
 649
 650         if (rc < 0)
 651                 goto out;
 652
 653         if (long_op == CIFS_STD_OP)
 654                 timeout = 15 * HZ;
 655         /* wait for 15 seconds or until woken up due to response arriving or
 656            due to last connection to this server being unmounted */
 657         else if (long_op == CIFS_ASYNC_OP)
 658                 goto out;
 659         else if (long_op == CIFS_VLONG_OP) /* writes past EOF can be slow */
 660                 timeout = 180 * HZ;
 661         else if (long_op == CIFS_LONG_OP)
 662                 timeout = 45 * HZ; /* should be greater than
 663                         servers oplock break timeout (about 43 seconds) */
 664         else if (long_op == CIFS_BLOCKING_OP)
 665                 timeout = 0x7FFFFFFF; /* large but no so large as to wrap */
 666         else {
 667                 cERROR(1, ("unknown timeout flag %d", long_op));
 668                 rc = -EIO;
 669                 goto out;
 670         }
 671
 672         if (signal_pending(current)) {
 673                 /* if signal pending do not hold up user for full smb timeout
 674                 but we still give response a chance to complete */
 675                 timeout = 2 * HZ;
 676         }
 677
 678         /* No user interrupts in wait - wreaks havoc with performance */
 679         wait_for_response(ses, midQ, timeout, 10 * HZ);
 680
 681         spin_lock(&GlobalMid_Lock);
 682         if (midQ->resp_buf == NULL) {
 683                 cERROR(1, ("No response for cmd %d mid %d",
 684                           midQ->command, midQ->mid));
 685                 if (midQ->midState == MID_REQUEST_SUBMITTED) {
 686                         if (ses->server->tcpStatus == CifsExiting)
 687                                 rc = -EHOSTDOWN;
 688                         else {
 689                                 ses->server->tcpStatus = CifsNeedReconnect;
 690                                 midQ->midState = MID_RETRY_NEEDED;
 691                         }
 692                 }
 693
 694                 if (rc != -EHOSTDOWN) {
 695                         if (midQ->midState == MID_RETRY_NEEDED) {
 696                                 rc = -EAGAIN;
 697                                 cFYI(1, ("marking request for retry"));
 698                         } else {
 699                                 rc = -EIO;
 700                         }
 701                 }
 702                 spin_unlock(&GlobalMid_Lock);
 703                 DeleteMidQEntry(midQ);
 704                 /* Update # of requests on wire to server */
 705                 atomic_dec(&ses->server->inFlight);
 706                 wake_up(&ses->server->request_q);
 707                 return rc;
 708         }
 709
 710         spin_unlock(&GlobalMid_Lock);
 711         receive_len = midQ->resp_buf->smb_buf_length;
 712
 713         if (receive_len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE) {
 714                 cERROR(1, ("Frame too large received.  Length: %d  Xid: %d",
 715                         receive_len, xid));
 716                 rc = -EIO;
 717                 goto out;
 718         }
 719
 720         /* rcvd frame is ok */
 721
 722         if (midQ->resp_buf && out_buf
 723             && (midQ->midState == MID_RESPONSE_RECEIVED)) {
 724                 out_buf->smb_buf_length = receive_len;
 725                 memcpy((char *)out_buf + 4,
 726                        (char *)midQ->resp_buf + 4,
 727                        receive_len);
 728
 729                 dump_smb(out_buf, 92);
 730                 /* convert the length into a more usable form */
 731                 if ((receive_len > 24) &&
 732                     (ses->server->secMode & (SECMODE_SIGN_REQUIRED |
 733                                              SECMODE_SIGN_ENABLED))) {
 734                         rc = cifs_verify_signature(out_buf,
 735                                                 &ses->server->mac_signing_key,
 736                                                 midQ->sequence_number+1);
 737                         if (rc) {
 738                                 cERROR(1, ("Unexpected SMB signature"));
 739                                 /* BB FIXME add code to kill session */
 740                         }
 741                 }
 742
 743                 *pbytes_returned = out_buf->smb_buf_length;
 744
 745                 /* BB special case reconnect tid and uid here? */
 746                 rc = map_smb_to_linux_error(out_buf, 0 /* no log */ );
 747
 748                 /* convert ByteCount if necessary */
 749                 if (receive_len >= sizeof(struct smb_hdr) - 4
 750                     /* do not count RFC1001 header */  +
 751                     (2 * out_buf->WordCount) + 2 /* bcc */ )
 752                         BCC(out_buf) = le16_to_cpu(BCC_LE(out_buf));
 753         } else {
 754                 rc = -EIO;
 755                 cERROR(1, ("Bad MID state?"));
 756         }
 757
 758 out:
 759         DeleteMidQEntry(midQ);
 760         atomic_dec(&ses->server->inFlight);
 761         wake_up(&ses->server->request_q);
 762
 763         return rc;
 764 }
 765
 766 /* Send an NT_CANCEL SMB to cause the POSIX blocking lock to return. */
 767
 768 static int
 769 send_nt_cancel(struct cifsTconInfo *tcon, struct smb_hdr *in_buf,
 770                 struct mid_q_entry *midQ)
 771 {
 772         int rc = 0;
 773         struct cifsSesInfo *ses = tcon->ses;
 774         __u16 mid = in_buf->Mid;
 775
 776         header_assemble(in_buf, SMB_COM_NT_CANCEL, tcon, 0);
 777         in_buf->Mid = mid;
 778         mutex_lock(&ses->server->srv_mutex);
 779         rc = cifs_sign_smb(in_buf, ses->server, &midQ->sequence_number);
 780         if (rc) {
 781                 mutex_unlock(&ses->server->srv_mutex);
 782                 return rc;
 783         }
 784         rc = smb_send(ses->server, in_buf, in_buf->smb_buf_length);
 785         mutex_unlock(&ses->server->srv_mutex);
 786         return rc;
 787 }
 788
 789 /* We send a LOCKINGX_CANCEL_LOCK to cause the Windows
 790    blocking lock to return. */
 791
 792 static int
 793 send_lock_cancel(const unsigned int xid, struct cifsTconInfo *tcon,
 794                         struct smb_hdr *in_buf,
 795                         struct smb_hdr *out_buf)
 796 {
 797         int bytes_returned;
 798         struct cifsSesInfo *ses = tcon->ses;
 799         LOCK_REQ *pSMB = (LOCK_REQ *)in_buf;
 800
 801         /* We just modify the current in_buf to change
 802            the type of lock from LOCKING_ANDX_SHARED_LOCK
 803            or LOCKING_ANDX_EXCLUSIVE_LOCK to
 804            LOCKING_ANDX_CANCEL_LOCK. */
 805
 806         pSMB->LockType = LOCKING_ANDX_CANCEL_LOCK|LOCKING_ANDX_LARGE_FILES;
 807         pSMB->Timeout = 0;
 808         pSMB->hdr.Mid = GetNextMid(ses->server);
 809
 810         return SendReceive(xid, ses, in_buf, out_buf,
 811                         &bytes_returned, CIFS_STD_OP);
 812 }
 813
 814 int
 815 SendReceiveBlockingLock(const unsigned int xid, struct cifsTconInfo *tcon,
 816             struct smb_hdr *in_buf, struct smb_hdr *out_buf,
 817             int *pbytes_returned)
 818 {
 819         int rc = 0;
 820         int rstart = 0;
 821         unsigned int receive_len;
 822         struct mid_q_entry *midQ;
 823         struct cifsSesInfo *ses;
 824
 825         if (tcon == NULL || tcon->ses == NULL) {
 826                 cERROR(1, ("Null smb session"));
 827                 return -EIO;
 828         }
 829         ses = tcon->ses;
 830
 831         if (ses->server == NULL) {
 832                 cERROR(1, ("Null tcp session"));
 833                 return -EIO;
 834         }
 835
 836         if (ses->server->tcpStatus == CifsExiting)
 837                 return -ENOENT;
 838
 839         /* Ensure that we do not send more than 50 overlapping requests
 840            to the same server. We may make this configurable later or
 841            use ses->maxReq */
 842
 843         if (in_buf->smb_buf_length > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) {
 844                 cERROR(1, ("Illegal length, greater than maximum frame, %d",
 845                            in_buf->smb_buf_length));
 846                 return -EIO;
 847         }
 848
 849         rc = wait_for_free_request(ses, CIFS_BLOCKING_OP);
 850         if (rc)
 851                 return rc;
 852
 853         /* make sure that we sign in the same order that we send on this socket
 854            and avoid races inside tcp sendmsg code that could cause corruption
 855            of smb data */
 856
 857         mutex_lock(&ses->server->srv_mutex);
 858
 859         rc = allocate_mid(ses, in_buf, &midQ);
 860         if (rc) {
 861                 mutex_unlock(&ses->server->srv_mutex);
 862                 return rc;
 863         }
 864
 865         rc = cifs_sign_smb(in_buf, ses->server, &midQ->sequence_number);
 866         if (rc) {
 867                 DeleteMidQEntry(midQ);
 868                 mutex_unlock(&ses->server->srv_mutex);
 869                 return rc;
 870         }
 871
 872         midQ->midState = MID_REQUEST_SUBMITTED;
 873 #ifdef CONFIG_CIFS_STATS2
 874         atomic_inc(&ses->server->inSend);
 875 #endif
 876         rc = smb_send(ses->server, in_buf, in_buf->smb_buf_length);
 877 #ifdef CONFIG_CIFS_STATS2
 878         atomic_dec(&ses->server->inSend);
 879         midQ->when_sent = jiffies;
 880 #endif
 881         mutex_unlock(&ses->server->srv_mutex);
 882
 883         if (rc < 0) {
 884                 DeleteMidQEntry(midQ);
 885                 return rc;
 886         }
 887
 888         /* Wait for a reply - allow signals to interrupt. */
 889         rc = wait_event_interruptible(ses->server->response_q,
 890                 (!(midQ->midState == MID_REQUEST_SUBMITTED)) ||
 891                 ((ses->server->tcpStatus != CifsGood) &&
 892                  (ses->server->tcpStatus != CifsNew)));
 893
 894         /* Were we interrupted by a signal ? */
 895         if ((rc == -ERESTARTSYS) &&
 896                 (midQ->midState == MID_REQUEST_SUBMITTED) &&
 897                 ((ses->server->tcpStatus == CifsGood) ||
 898                  (ses->server->tcpStatus == CifsNew))) {
 899
 900                 if (in_buf->Command == SMB_COM_TRANSACTION2) {
 901                         /* POSIX lock. We send a NT_CANCEL SMB to cause the
 902                            blocking lock to return. */
 903
 904                         rc = send_nt_cancel(tcon, in_buf, midQ);
 905                         if (rc) {
 906                                 DeleteMidQEntry(midQ);
 907                                 return rc;
 908                         }
 909                 } else {
 910                         /* Windows lock. We send a LOCKINGX_CANCEL_LOCK
 911                            to cause the blocking lock to return. */
 912
 913                         rc = send_lock_cancel(xid, tcon, in_buf, out_buf);
 914
 915                         /* If we get -ENOLCK back the lock may have
 916                            already been removed. Don't exit in this case. */
 917                         if (rc && rc != -ENOLCK) {
 918                                 DeleteMidQEntry(midQ);
 919                                 return rc;
 920                         }
 921                 }
 922
 923                 /* Wait 5 seconds for the response. */
 924                 if (wait_for_response(ses, midQ, 5 * HZ, 5 * HZ) == 0) {
 925                         /* We got the response - restart system call. */
 926                         rstart = 1;
 927                 }
 928         }
 929
 930         spin_lock(&GlobalMid_Lock);
 931         if (midQ->resp_buf) {
 932                 spin_unlock(&GlobalMid_Lock);
 933                 receive_len = midQ->resp_buf->smb_buf_length;
 934         } else {
 935                 cERROR(1, ("No response for cmd %d mid %d",
 936                           midQ->command, midQ->mid));
 937                 if (midQ->midState == MID_REQUEST_SUBMITTED) {
 938                         if (ses->server->tcpStatus == CifsExiting)
 939                                 rc = -EHOSTDOWN;
 940                         else {
 941                                 ses->server->tcpStatus = CifsNeedReconnect;
 942                                 midQ->midState = MID_RETRY_NEEDED;
 943                         }
 944                 }
 945
 946                 if (rc != -EHOSTDOWN) {
 947                         if (midQ->midState == MID_RETRY_NEEDED) {
 948                                 rc = -EAGAIN;
 949                                 cFYI(1, ("marking request for retry"));
 950                         } else {
 951                                 rc = -EIO;
 952                         }
 953                 }
 954                 spin_unlock(&GlobalMid_Lock);
 955                 DeleteMidQEntry(midQ);
 956                 return rc;
 957         }
 958
 959         if (receive_len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE) {
 960                 cERROR(1, ("Frame too large received.  Length: %d  Xid: %d",
 961                         receive_len, xid));
 962                 rc = -EIO;
 963                 goto out;
 964         }
 965
 966         /* rcvd frame is ok */
 967
 968         if ((out_buf == NULL) || (midQ->midState != MID_RESPONSE_RECEIVED)) {
 969                 rc = -EIO;
 970                 cERROR(1, ("Bad MID state?"));
 971                 goto out;
 972         }
 973
 974         out_buf->smb_buf_length = receive_len;
 975         memcpy((char *)out_buf + 4,
 976                (char *)midQ->resp_buf + 4,
 977                receive_len);
 978
 979         dump_smb(out_buf, 92);
 980         /* convert the length into a more usable form */
 981         if ((receive_len > 24) &&
 982             (ses->server->secMode & (SECMODE_SIGN_REQUIRED |
 983                                      SECMODE_SIGN_ENABLED))) {
 984                 rc = cifs_verify_signature(out_buf,
 985                                            &ses->server->mac_signing_key,
 986                                            midQ->sequence_number+1);
 987                 if (rc) {
 988                         cERROR(1, ("Unexpected SMB signature"));
 989                         /* BB FIXME add code to kill session */
 990                 }
 991         }
 992
 993         *pbytes_returned = out_buf->smb_buf_length;
 994
 995         /* BB special case reconnect tid and uid here? */
 996         rc = map_smb_to_linux_error(out_buf, 0 /* no log */ );
 997
 998         /* convert ByteCount if necessary */
 999         if (receive_len >= sizeof(struct smb_hdr) - 4
1000             /* do not count RFC1001 header */  +
1001             (2 * out_buf->WordCount) + 2 /* bcc */ )
1002                 BCC(out_buf) = le16_to_cpu(BCC_LE(out_buf));
1003
1004 out:
1005         DeleteMidQEntry(midQ);
1006         if (rstart && rc == -EACCES)
1007                 return -ERESTARTSYS;
1008         return rc;
1009 }