Pileus Git - ~andy/linux/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/gfp.h>
  26 #include <linux/wait.h>
  27 #include <linux/net.h>
  28 #include <linux/delay.h>
  29 #include <asm/uaccess.h>
  30 #include <asm/processor.h>
  31 #include <linux/mempool.h>
  32 #include "cifspdu.h"
  33 #include "cifsglob.h"
  34 #include "cifsproto.h"
  35 #include "cifs_debug.h"
  36
  37 extern mempool_t *cifs_mid_poolp;
  38
  39 static void
  40 wake_up_task(struct mid_q_entry *mid)
  41 {
  42         wake_up_process(mid->callback_data);
  43 }
  44
  45 struct mid_q_entry *
  46 AllocMidQEntry(const struct smb_hdr *smb_buffer, struct TCP_Server_Info *server)
  47 {
  48         struct mid_q_entry *temp;
  49
  50         if (server == NULL) {
  51                 cERROR(1, "Null TCP session in AllocMidQEntry");
  52                 return NULL;
  53         }
  54
  55         temp = mempool_alloc(cifs_mid_poolp, GFP_NOFS);
  56         if (temp == NULL)
  57                 return temp;
  58         else {
  59                 memset(temp, 0, sizeof(struct mid_q_entry));
  60                 temp->mid = smb_buffer->Mid;    /* always LE */
  61                 temp->pid = current->pid;
  62                 temp->command = smb_buffer->Command;
  63                 cFYI(1, "For smb_command %d", temp->command);
  64         /*      do_gettimeofday(&temp->when_sent);*/ /* easier to use jiffies */
  65                 /* when mid allocated can be before when sent */
  66                 temp->when_alloc = jiffies;
  67
  68                 /*
  69                  * The default is for the mid to be synchronous, so the
  70                  * default callback just wakes up the current task.
  71                  */
  72                 temp->callback = wake_up_task;
  73                 temp->callback_data = current;
  74         }
  75
  76         atomic_inc(&midCount);
  77         temp->midState = MID_REQUEST_ALLOCATED;
  78         return temp;
  79 }
  80
  81 void
  82 DeleteMidQEntry(struct mid_q_entry *midEntry)
  83 {
  84 #ifdef CONFIG_CIFS_STATS2
  85         unsigned long now;
  86 #endif
  87         midEntry->midState = MID_FREE;
  88         atomic_dec(&midCount);
  89         if (midEntry->largeBuf)
  90                 cifs_buf_release(midEntry->resp_buf);
  91         else
  92                 cifs_small_buf_release(midEntry->resp_buf);
  93 #ifdef CONFIG_CIFS_STATS2
  94         now = jiffies;
  95         /* commands taking longer than one second are indications that
  96            something is wrong, unless it is quite a slow link or server */
  97         if ((now - midEntry->when_alloc) > HZ) {
  98                 if ((cifsFYI & CIFS_TIMER) &&
  99                    (midEntry->command != SMB_COM_LOCKING_ANDX)) {
 100                         printk(KERN_DEBUG " CIFS slow rsp: cmd %d mid %d",
 101                                midEntry->command, midEntry->mid);
 102                         printk(" A: 0x%lx S: 0x%lx R: 0x%lx\n",
 103                                now - midEntry->when_alloc,
 104                                now - midEntry->when_sent,
 105                                now - midEntry->when_received);
 106                 }
 107         }
 108 #endif
 109         mempool_free(midEntry, cifs_mid_poolp);
 110 }
 111
 112 static void
 113 delete_mid(struct mid_q_entry *mid)
 114 {
 115         spin_lock(&GlobalMid_Lock);
 116         list_del(&mid->qhead);
 117         spin_unlock(&GlobalMid_Lock);
 118
 119         DeleteMidQEntry(mid);
 120 }
 121
 122 static int
 123 smb_sendv(struct TCP_Server_Info *server, struct kvec *iov, int n_vec)
 124 {
 125         int rc = 0;
 126         int i = 0;
 127         struct msghdr smb_msg;
 128         struct smb_hdr *smb_buffer = iov[0].iov_base;
 129         unsigned int len = iov[0].iov_len;
 130         unsigned int total_len;
 131         int first_vec = 0;
 132         unsigned int smb_buf_length = smb_buffer->smb_buf_length;
 133         struct socket *ssocket = server->ssocket;
 134
 135         if (ssocket == NULL)
 136                 return -ENOTSOCK; /* BB eventually add reconnect code here */
 137
 138         smb_msg.msg_name = (struct sockaddr *) &server->dstaddr;
 139         smb_msg.msg_namelen = sizeof(struct sockaddr);
 140         smb_msg.msg_control = NULL;
 141         smb_msg.msg_controllen = 0;
 142         if (server->noblocksnd)
 143                 smb_msg.msg_flags = MSG_DONTWAIT + MSG_NOSIGNAL;
 144         else
 145                 smb_msg.msg_flags = MSG_NOSIGNAL;
 146
 147         /* smb header is converted in header_assemble. bcc and rest of SMB word
 148            area, and byte area if necessary, is converted to littleendian in
 149            cifssmb.c and RFC1001 len is converted to bigendian in smb_send
 150            Flags2 is converted in SendReceive */
 151
 152
 153         total_len = 0;
 154         for (i = 0; i < n_vec; i++)
 155                 total_len += iov[i].iov_len;
 156
 157         smb_buffer->smb_buf_length = cpu_to_be32(smb_buffer->smb_buf_length);
 158         cFYI(1, "Sending smb:  total_len %d", total_len);
 159         dump_smb(smb_buffer, len);
 160
 161         i = 0;
 162         while (total_len) {
 163                 rc = kernel_sendmsg(ssocket, &smb_msg, &iov[first_vec],
 164                                     n_vec - first_vec, total_len);
 165                 if ((rc == -ENOSPC) || (rc == -EAGAIN)) {
 166                         i++;
 167                         /* if blocking send we try 3 times, since each can block
 168                            for 5 seconds. For nonblocking  we have to try more
 169                            but wait increasing amounts of time allowing time for
 170                            socket to clear.  The overall time we wait in either
 171                            case to send on the socket is about 15 seconds.
 172                            Similarly we wait for 15 seconds for
 173                            a response from the server in SendReceive[2]
 174                            for the server to send a response back for
 175                            most types of requests (except SMB Write
 176                            past end of file which can be slow, and
 177                            blocking lock operations). NFS waits slightly longer
 178                            than CIFS, but this can make it take longer for
 179                            nonresponsive servers to be detected and 15 seconds
 180                            is more than enough time for modern networks to
 181                            send a packet.  In most cases if we fail to send
 182                            after the retries we will kill the socket and
 183                            reconnect which may clear the network problem.
 184                         */
 185                         if ((i >= 14) || (!server->noblocksnd && (i > 2))) {
 186                                 cERROR(1, "sends on sock %p stuck for 15 seconds",
 187                                     ssocket);
 188                                 rc = -EAGAIN;
 189                                 break;
 190                         }
 191                         msleep(1 << i);
 192                         continue;
 193                 }
 194                 if (rc < 0)
 195                         break;
 196
 197                 if (rc == total_len) {
 198                         total_len = 0;
 199                         break;
 200                 } else if (rc > total_len) {
 201                         cERROR(1, "sent %d requested %d", rc, total_len);
 202                         break;
 203                 }
 204                 if (rc == 0) {
 205                         /* should never happen, letting socket clear before
 206                            retrying is our only obvious option here */
 207                         cERROR(1, "tcp sent no data");
 208                         msleep(500);
 209                         continue;
 210                 }
 211                 total_len -= rc;
 212                 /* the line below resets i */
 213                 for (i = first_vec; i < n_vec; i++) {
 214                         if (iov[i].iov_len) {
 215                                 if (rc > iov[i].iov_len) {
 216                                         rc -= iov[i].iov_len;
 217                                         iov[i].iov_len = 0;
 218                                 } else {
 219                                         iov[i].iov_base += rc;
 220                                         iov[i].iov_len -= rc;
 221                                         first_vec = i;
 222                                         break;
 223                                 }
 224                         }
 225                 }
 226                 i = 0; /* in case we get ENOSPC on the next send */
 227         }
 228
 229         if ((total_len > 0) && (total_len != smb_buf_length + 4)) {
 230                 cFYI(1, "partial send (%d remaining), terminating session",
 231                         total_len);
 232                 /* If we have only sent part of an SMB then the next SMB
 233                    could be taken as the remainder of this one.  We need
 234                    to kill the socket so the server throws away the partial
 235                    SMB */
 236                 server->tcpStatus = CifsNeedReconnect;
 237         }
 238
 239         if (rc < 0) {
 240                 cERROR(1, "Error %d sending data on socket to server", rc);
 241         } else
 242                 rc = 0;
 243
 244         /* Don't want to modify the buffer as a
 245            side effect of this call. */
 246         smb_buffer->smb_buf_length = smb_buf_length;
 247
 248         return rc;
 249 }
 250
 251 int
 252 smb_send(struct TCP_Server_Info *server, struct smb_hdr *smb_buffer,
 253          unsigned int smb_buf_length)
 254 {
 255         struct kvec iov;
 256
 257         iov.iov_base = smb_buffer;
 258         iov.iov_len = smb_buf_length + 4;
 259
 260         return smb_sendv(server, &iov, 1);
 261 }
 262
 263 static int wait_for_free_request(struct TCP_Server_Info *server,
 264                                  const int long_op)
 265 {
 266         if (long_op == CIFS_ASYNC_OP) {
 267                 /* oplock breaks must not be held up */
 268                 atomic_inc(&server->inFlight);
 269                 return 0;
 270         }
 271
 272         spin_lock(&GlobalMid_Lock);
 273         while (1) {
 274                 if (atomic_read(&server->inFlight) >= cifs_max_pending) {
 275                         spin_unlock(&GlobalMid_Lock);
 276 #ifdef CONFIG_CIFS_STATS2
 277                         atomic_inc(&server->num_waiters);
 278 #endif
 279                         wait_event(server->request_q,
 280                                    atomic_read(&server->inFlight)
 281                                      < cifs_max_pending);
 282 #ifdef CONFIG_CIFS_STATS2
 283                         atomic_dec(&server->num_waiters);
 284 #endif
 285                         spin_lock(&GlobalMid_Lock);
 286                 } else {
 287                         if (server->tcpStatus == CifsExiting) {
 288                                 spin_unlock(&GlobalMid_Lock);
 289                                 return -ENOENT;
 290                         }
 291
 292                         /* can not count locking commands against total
 293                            as they are allowed to block on server */
 294
 295                         /* update # of requests on the wire to server */
 296                         if (long_op != CIFS_BLOCKING_OP)
 297                                 atomic_inc(&server->inFlight);
 298                         spin_unlock(&GlobalMid_Lock);
 299                         break;
 300                 }
 301         }
 302         return 0;
 303 }
 304
 305 static int allocate_mid(struct cifsSesInfo *ses, struct smb_hdr *in_buf,
 306                         struct mid_q_entry **ppmidQ)
 307 {
 308         if (ses->server->tcpStatus == CifsExiting) {
 309                 return -ENOENT;
 310         }
 311
 312         if (ses->server->tcpStatus == CifsNeedReconnect) {
 313                 cFYI(1, "tcp session dead - return to caller to retry");
 314                 return -EAGAIN;
 315         }
 316
 317         if (ses->status != CifsGood) {
 318                 /* check if SMB session is bad because we are setting it up */
 319                 if ((in_buf->Command != SMB_COM_SESSION_SETUP_ANDX) &&
 320                         (in_buf->Command != SMB_COM_NEGOTIATE))
 321                         return -EAGAIN;
 322                 /* else ok - we are setting up session */
 323         }
 324         *ppmidQ = AllocMidQEntry(in_buf, ses->server);
 325         if (*ppmidQ == NULL)
 326                 return -ENOMEM;
 327         spin_lock(&GlobalMid_Lock);
 328         list_add_tail(&(*ppmidQ)->qhead, &ses->server->pending_mid_q);
 329         spin_unlock(&GlobalMid_Lock);
 330         return 0;
 331 }
 332
 333 static int
 334 wait_for_response(struct TCP_Server_Info *server, struct mid_q_entry *midQ)
 335 {
 336         int error;
 337
 338         error = wait_event_killable(server->response_q,
 339                                     midQ->midState != MID_REQUEST_SUBMITTED);
 340         if (error < 0)
 341                 return -ERESTARTSYS;
 342
 343         return 0;
 344 }
 345
 346
 347 /*
 348  * Send a SMB request and set the callback function in the mid to handle
 349  * the result. Caller is responsible for dealing with timeouts.
 350  */
 351 int
 352 cifs_call_async(struct TCP_Server_Info *server, struct smb_hdr *in_buf,
 353                 mid_callback_t *callback, void *cbdata)
 354 {
 355         int rc;
 356         struct mid_q_entry *mid;
 357
 358         rc = wait_for_free_request(server, CIFS_ASYNC_OP);
 359         if (rc)
 360                 return rc;
 361
 362         mutex_lock(&server->srv_mutex);
 363         mid = AllocMidQEntry(in_buf, server);
 364         if (mid == NULL) {
 365                 mutex_unlock(&server->srv_mutex);
 366                 return -ENOMEM;
 367         }
 368
 369         /* put it on the pending_mid_q */
 370         spin_lock(&GlobalMid_Lock);
 371         list_add_tail(&mid->qhead, &server->pending_mid_q);
 372         spin_unlock(&GlobalMid_Lock);
 373
 374         rc = cifs_sign_smb(in_buf, server, &mid->sequence_number);
 375         if (rc) {
 376                 mutex_unlock(&server->srv_mutex);
 377                 goto out_err;
 378         }
 379
 380         mid->callback = callback;
 381         mid->callback_data = cbdata;
 382         mid->midState = MID_REQUEST_SUBMITTED;
 383 #ifdef CONFIG_CIFS_STATS2
 384         atomic_inc(&server->inSend);
 385 #endif
 386         rc = smb_send(server, in_buf, in_buf->smb_buf_length);
 387 #ifdef CONFIG_CIFS_STATS2
 388         atomic_dec(&server->inSend);
 389         mid->when_sent = jiffies;
 390 #endif
 391         mutex_unlock(&server->srv_mutex);
 392         if (rc)
 393                 goto out_err;
 394
 395         return rc;
 396 out_err:
 397         delete_mid(mid);
 398         atomic_dec(&server->inFlight);
 399         wake_up(&server->request_q);
 400         return rc;
 401 }
 402
 403 /*
 404  *
 405  * Send an SMB Request.  No response info (other than return code)
 406  * needs to be parsed.
 407  *
 408  * flags indicate the type of request buffer and how long to wait
 409  * and whether to log NT STATUS code (error) before mapping it to POSIX error
 410  *
 411  */
 412 int
 413 SendReceiveNoRsp(const unsigned int xid, struct cifsSesInfo *ses,
 414                 struct smb_hdr *in_buf, int flags)
 415 {
 416         int rc;
 417         struct kvec iov[1];
 418         int resp_buf_type;
 419
 420         iov[0].iov_base = (char *)in_buf;
 421         iov[0].iov_len = in_buf->smb_buf_length + 4;
 422         flags |= CIFS_NO_RESP;
 423         rc = SendReceive2(xid, ses, iov, 1, &resp_buf_type, flags);
 424         cFYI(DBG2, "SendRcvNoRsp flags %d rc %d", flags, rc);
 425
 426         return rc;
 427 }
 428
 429 static int
 430 sync_mid_result(struct mid_q_entry *mid, struct TCP_Server_Info *server)
 431 {
 432         int rc = 0;
 433
 434         cFYI(1, "%s: cmd=%d mid=%d state=%d", __func__, mid->command,
 435                 mid->mid, mid->midState);
 436
 437         spin_lock(&GlobalMid_Lock);
 438         /* ensure that it's no longer on the pending_mid_q */
 439         list_del_init(&mid->qhead);
 440
 441         switch (mid->midState) {
 442         case MID_RESPONSE_RECEIVED:
 443                 spin_unlock(&GlobalMid_Lock);
 444                 return rc;
 445         case MID_REQUEST_SUBMITTED:
 446                 /* socket is going down, reject all calls */
 447                 if (server->tcpStatus == CifsExiting) {
 448                         cERROR(1, "%s: canceling mid=%d cmd=0x%x state=%d",
 449                                __func__, mid->mid, mid->command, mid->midState);
 450                         rc = -EHOSTDOWN;
 451                         break;
 452                 }
 453         case MID_RETRY_NEEDED:
 454                 rc = -EAGAIN;
 455                 break;
 456         default:
 457                 cERROR(1, "%s: invalid mid state mid=%d state=%d", __func__,
 458                         mid->mid, mid->midState);
 459                 rc = -EIO;
 460         }
 461         spin_unlock(&GlobalMid_Lock);
 462
 463         DeleteMidQEntry(mid);
 464         return rc;
 465 }
 466
 467 int
 468 SendReceive2(const unsigned int xid, struct cifsSesInfo *ses,
 469              struct kvec *iov, int n_vec, int *pRespBufType /* ret */,
 470              const int flags)
 471 {
 472         int rc = 0;
 473         int long_op;
 474         unsigned int receive_len;
 475         struct mid_q_entry *midQ;
 476         struct smb_hdr *in_buf = iov[0].iov_base;
 477
 478         long_op = flags & CIFS_TIMEOUT_MASK;
 479
 480         *pRespBufType = CIFS_NO_BUFFER;  /* no response buf yet */
 481
 482         if ((ses == NULL) || (ses->server == NULL)) {
 483                 cifs_small_buf_release(in_buf);
 484                 cERROR(1, "Null session");
 485                 return -EIO;
 486         }
 487
 488         if (ses->server->tcpStatus == CifsExiting) {
 489                 cifs_small_buf_release(in_buf);
 490                 return -ENOENT;
 491         }
 492
 493         /* Ensure that we do not send more than 50 overlapping requests
 494            to the same server. We may make this configurable later or
 495            use ses->maxReq */
 496
 497         rc = wait_for_free_request(ses->server, long_op);
 498         if (rc) {
 499                 cifs_small_buf_release(in_buf);
 500                 return rc;
 501         }
 502
 503         /* make sure that we sign in the same order that we send on this socket
 504            and avoid races inside tcp sendmsg code that could cause corruption
 505            of smb data */
 506
 507         mutex_lock(&ses->server->srv_mutex);
 508
 509         rc = allocate_mid(ses, in_buf, &midQ);
 510         if (rc) {
 511                 mutex_unlock(&ses->server->srv_mutex);
 512                 cifs_small_buf_release(in_buf);
 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         rc = cifs_sign_smb2(iov, n_vec, ses->server, &midQ->sequence_number);
 519         if (rc) {
 520                 mutex_unlock(&ses->server->srv_mutex);
 521                 cifs_small_buf_release(in_buf);
 522                 goto out;
 523         }
 524
 525         midQ->midState = MID_REQUEST_SUBMITTED;
 526 #ifdef CONFIG_CIFS_STATS2
 527         atomic_inc(&ses->server->inSend);
 528 #endif
 529         rc = smb_sendv(ses->server, iov, n_vec);
 530 #ifdef CONFIG_CIFS_STATS2
 531         atomic_dec(&ses->server->inSend);
 532         midQ->when_sent = jiffies;
 533 #endif
 534
 535         mutex_unlock(&ses->server->srv_mutex);
 536         cifs_small_buf_release(in_buf);
 537
 538         if (rc < 0)
 539                 goto out;
 540
 541         if (long_op == CIFS_ASYNC_OP)
 542                 goto out;
 543
 544         rc = wait_for_response(ses->server, midQ);
 545         if (rc != 0)
 546                 goto out;
 547
 548         rc = sync_mid_result(midQ, ses->server);
 549         if (rc != 0) {
 550                 atomic_dec(&ses->server->inFlight);
 551                 wake_up(&ses->server->request_q);
 552                 return rc;
 553         }
 554
 555         receive_len = midQ->resp_buf->smb_buf_length;
 556
 557         if (receive_len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE) {
 558                 cERROR(1, "Frame too large received.  Length: %d  Xid: %d",
 559                         receive_len, xid);
 560                 rc = -EIO;
 561                 goto out;
 562         }
 563
 564         /* rcvd frame is ok */
 565
 566         if (midQ->resp_buf &&
 567             (midQ->midState == MID_RESPONSE_RECEIVED)) {
 568
 569                 iov[0].iov_base = (char *)midQ->resp_buf;
 570                 if (midQ->largeBuf)
 571                         *pRespBufType = CIFS_LARGE_BUFFER;
 572                 else
 573                         *pRespBufType = CIFS_SMALL_BUFFER;
 574                 iov[0].iov_len = receive_len + 4;
 575
 576                 dump_smb(midQ->resp_buf, 80);
 577                 /* convert the length into a more usable form */
 578                 if ((receive_len > 24) &&
 579                     (ses->server->secMode & (SECMODE_SIGN_REQUIRED |
 580                                              SECMODE_SIGN_ENABLED))) {
 581                         rc = cifs_verify_signature(midQ->resp_buf,
 582                                                 ses->server,
 583                                                 midQ->sequence_number+1);
 584                         if (rc) {
 585                                 cERROR(1, "Unexpected SMB signature");
 586                                 /* BB FIXME add code to kill session */
 587                         }
 588                 }
 589
 590                 /* BB special case reconnect tid and uid here? */
 591                 rc = map_smb_to_linux_error(midQ->resp_buf,
 592                                             flags & CIFS_LOG_ERROR);
 593
 594                 /* convert ByteCount if necessary */
 595                 if (receive_len >= sizeof(struct smb_hdr) - 4
 596                     /* do not count RFC1001 header */  +
 597                     (2 * midQ->resp_buf->WordCount) + 2 /* bcc */ )
 598                         BCC(midQ->resp_buf) =
 599                                 le16_to_cpu(BCC_LE(midQ->resp_buf));
 600                 if ((flags & CIFS_NO_RESP) == 0)
 601                         midQ->resp_buf = NULL;  /* mark it so buf will
 602                                                    not be freed by
 603                                                    delete_mid */
 604         } else {
 605                 rc = -EIO;
 606                 cFYI(1, "Bad MID state?");
 607         }
 608
 609 out:
 610         delete_mid(midQ);
 611         atomic_dec(&ses->server->inFlight);
 612         wake_up(&ses->server->request_q);
 613
 614         return rc;
 615 }
 616
 617 int
 618 SendReceive(const unsigned int xid, struct cifsSesInfo *ses,
 619             struct smb_hdr *in_buf, struct smb_hdr *out_buf,
 620             int *pbytes_returned, const int long_op)
 621 {
 622         int rc = 0;
 623         unsigned int receive_len;
 624         struct mid_q_entry *midQ;
 625
 626         if (ses == NULL) {
 627                 cERROR(1, "Null smb session");
 628                 return -EIO;
 629         }
 630         if (ses->server == NULL) {
 631                 cERROR(1, "Null tcp session");
 632                 return -EIO;
 633         }
 634
 635         if (ses->server->tcpStatus == CifsExiting)
 636                 return -ENOENT;
 637
 638         /* Ensure that we do not send more than 50 overlapping requests
 639            to the same server. We may make this configurable later or
 640            use ses->maxReq */
 641
 642         if (in_buf->smb_buf_length > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) {
 643                 cERROR(1, "Illegal length, greater than maximum frame, %d",
 644                            in_buf->smb_buf_length);
 645                 return -EIO;
 646         }
 647
 648         rc = wait_for_free_request(ses->server, long_op);
 649         if (rc)
 650                 return rc;
 651
 652         /* make sure that we sign in the same order that we send on this socket
 653            and avoid races inside tcp sendmsg code that could cause corruption
 654            of smb data */
 655
 656         mutex_lock(&ses->server->srv_mutex);
 657
 658         rc = allocate_mid(ses, in_buf, &midQ);
 659         if (rc) {
 660                 mutex_unlock(&ses->server->srv_mutex);
 661                 /* Update # of requests on wire to server */
 662                 atomic_dec(&ses->server->inFlight);
 663                 wake_up(&ses->server->request_q);
 664                 return rc;
 665         }
 666
 667         rc = cifs_sign_smb(in_buf, ses->server, &midQ->sequence_number);
 668         if (rc) {
 669                 mutex_unlock(&ses->server->srv_mutex);
 670                 goto out;
 671         }
 672
 673         midQ->midState = MID_REQUEST_SUBMITTED;
 674 #ifdef CONFIG_CIFS_STATS2
 675         atomic_inc(&ses->server->inSend);
 676 #endif
 677         rc = smb_send(ses->server, in_buf, in_buf->smb_buf_length);
 678 #ifdef CONFIG_CIFS_STATS2
 679         atomic_dec(&ses->server->inSend);
 680         midQ->when_sent = jiffies;
 681 #endif
 682         mutex_unlock(&ses->server->srv_mutex);
 683
 684         if (rc < 0)
 685                 goto out;
 686
 687         if (long_op == CIFS_ASYNC_OP)
 688                 goto out;
 689
 690         rc = wait_for_response(ses->server, midQ);
 691         if (rc != 0)
 692                 goto out;
 693
 694         rc = sync_mid_result(midQ, ses->server);
 695         if (rc != 0) {
 696                 atomic_dec(&ses->server->inFlight);
 697                 wake_up(&ses->server->request_q);
 698                 return rc;
 699         }
 700
 701         receive_len = midQ->resp_buf->smb_buf_length;
 702
 703         if (receive_len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE) {
 704                 cERROR(1, "Frame too large received.  Length: %d  Xid: %d",
 705                         receive_len, xid);
 706                 rc = -EIO;
 707                 goto out;
 708         }
 709
 710         /* rcvd frame is ok */
 711
 712         if (midQ->resp_buf && out_buf
 713             && (midQ->midState == MID_RESPONSE_RECEIVED)) {
 714                 out_buf->smb_buf_length = receive_len;
 715                 memcpy((char *)out_buf + 4,
 716                        (char *)midQ->resp_buf + 4,
 717                        receive_len);
 718
 719                 dump_smb(out_buf, 92);
 720                 /* convert the length into a more usable form */
 721                 if ((receive_len > 24) &&
 722                     (ses->server->secMode & (SECMODE_SIGN_REQUIRED |
 723                                              SECMODE_SIGN_ENABLED))) {
 724                         rc = cifs_verify_signature(out_buf,
 725                                                 ses->server,
 726                                                 midQ->sequence_number+1);
 727                         if (rc) {
 728                                 cERROR(1, "Unexpected SMB signature");
 729                                 /* BB FIXME add code to kill session */
 730                         }
 731                 }
 732
 733                 *pbytes_returned = out_buf->smb_buf_length;
 734
 735                 /* BB special case reconnect tid and uid here? */
 736                 rc = map_smb_to_linux_error(out_buf, 0 /* no log */ );
 737
 738                 /* convert ByteCount if necessary */
 739                 if (receive_len >= sizeof(struct smb_hdr) - 4
 740                     /* do not count RFC1001 header */  +
 741                     (2 * out_buf->WordCount) + 2 /* bcc */ )
 742                         BCC(out_buf) = le16_to_cpu(BCC_LE(out_buf));
 743         } else {
 744                 rc = -EIO;
 745                 cERROR(1, "Bad MID state?");
 746         }
 747
 748 out:
 749         delete_mid(midQ);
 750         atomic_dec(&ses->server->inFlight);
 751         wake_up(&ses->server->request_q);
 752
 753         return rc;
 754 }
 755
 756 /* Send an NT_CANCEL SMB to cause the POSIX blocking lock to return. */
 757
 758 static int
 759 send_nt_cancel(struct cifsTconInfo *tcon, struct smb_hdr *in_buf,
 760                 struct mid_q_entry *midQ)
 761 {
 762         int rc = 0;
 763         struct cifsSesInfo *ses = tcon->ses;
 764         __u16 mid = in_buf->Mid;
 765
 766         header_assemble(in_buf, SMB_COM_NT_CANCEL, tcon, 0);
 767         in_buf->Mid = mid;
 768         mutex_lock(&ses->server->srv_mutex);
 769         rc = cifs_sign_smb(in_buf, ses->server, &midQ->sequence_number);
 770         if (rc) {
 771                 mutex_unlock(&ses->server->srv_mutex);
 772                 return rc;
 773         }
 774         rc = smb_send(ses->server, in_buf, in_buf->smb_buf_length);
 775         mutex_unlock(&ses->server->srv_mutex);
 776         return rc;
 777 }
 778
 779 /* We send a LOCKINGX_CANCEL_LOCK to cause the Windows
 780    blocking lock to return. */
 781
 782 static int
 783 send_lock_cancel(const unsigned int xid, struct cifsTconInfo *tcon,
 784                         struct smb_hdr *in_buf,
 785                         struct smb_hdr *out_buf)
 786 {
 787         int bytes_returned;
 788         struct cifsSesInfo *ses = tcon->ses;
 789         LOCK_REQ *pSMB = (LOCK_REQ *)in_buf;
 790
 791         /* We just modify the current in_buf to change
 792            the type of lock from LOCKING_ANDX_SHARED_LOCK
 793            or LOCKING_ANDX_EXCLUSIVE_LOCK to
 794            LOCKING_ANDX_CANCEL_LOCK. */
 795
 796         pSMB->LockType = LOCKING_ANDX_CANCEL_LOCK|LOCKING_ANDX_LARGE_FILES;
 797         pSMB->Timeout = 0;
 798         pSMB->hdr.Mid = GetNextMid(ses->server);
 799
 800         return SendReceive(xid, ses, in_buf, out_buf,
 801                         &bytes_returned, CIFS_STD_OP);
 802 }
 803
 804 int
 805 SendReceiveBlockingLock(const unsigned int xid, struct cifsTconInfo *tcon,
 806             struct smb_hdr *in_buf, struct smb_hdr *out_buf,
 807             int *pbytes_returned)
 808 {
 809         int rc = 0;
 810         int rstart = 0;
 811         unsigned int receive_len;
 812         struct mid_q_entry *midQ;
 813         struct cifsSesInfo *ses;
 814
 815         if (tcon == NULL || tcon->ses == NULL) {
 816                 cERROR(1, "Null smb session");
 817                 return -EIO;
 818         }
 819         ses = tcon->ses;
 820
 821         if (ses->server == NULL) {
 822                 cERROR(1, "Null tcp session");
 823                 return -EIO;
 824         }
 825
 826         if (ses->server->tcpStatus == CifsExiting)
 827                 return -ENOENT;
 828
 829         /* Ensure that we do not send more than 50 overlapping requests
 830            to the same server. We may make this configurable later or
 831            use ses->maxReq */
 832
 833         if (in_buf->smb_buf_length > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) {
 834                 cERROR(1, "Illegal length, greater than maximum frame, %d",
 835                            in_buf->smb_buf_length);
 836                 return -EIO;
 837         }
 838
 839         rc = wait_for_free_request(ses->server, CIFS_BLOCKING_OP);
 840         if (rc)
 841                 return rc;
 842
 843         /* make sure that we sign in the same order that we send on this socket
 844            and avoid races inside tcp sendmsg code that could cause corruption
 845            of smb data */
 846
 847         mutex_lock(&ses->server->srv_mutex);
 848
 849         rc = allocate_mid(ses, in_buf, &midQ);
 850         if (rc) {
 851                 mutex_unlock(&ses->server->srv_mutex);
 852                 return rc;
 853         }
 854
 855         rc = cifs_sign_smb(in_buf, ses->server, &midQ->sequence_number);
 856         if (rc) {
 857                 delete_mid(midQ);
 858                 mutex_unlock(&ses->server->srv_mutex);
 859                 return rc;
 860         }
 861
 862         midQ->midState = MID_REQUEST_SUBMITTED;
 863 #ifdef CONFIG_CIFS_STATS2
 864         atomic_inc(&ses->server->inSend);
 865 #endif
 866         rc = smb_send(ses->server, in_buf, in_buf->smb_buf_length);
 867 #ifdef CONFIG_CIFS_STATS2
 868         atomic_dec(&ses->server->inSend);
 869         midQ->when_sent = jiffies;
 870 #endif
 871         mutex_unlock(&ses->server->srv_mutex);
 872
 873         if (rc < 0) {
 874                 delete_mid(midQ);
 875                 return rc;
 876         }
 877
 878         /* Wait for a reply - allow signals to interrupt. */
 879         rc = wait_event_interruptible(ses->server->response_q,
 880                 (!(midQ->midState == MID_REQUEST_SUBMITTED)) ||
 881                 ((ses->server->tcpStatus != CifsGood) &&
 882                  (ses->server->tcpStatus != CifsNew)));
 883
 884         /* Were we interrupted by a signal ? */
 885         if ((rc == -ERESTARTSYS) &&
 886                 (midQ->midState == MID_REQUEST_SUBMITTED) &&
 887                 ((ses->server->tcpStatus == CifsGood) ||
 888                  (ses->server->tcpStatus == CifsNew))) {
 889
 890                 if (in_buf->Command == SMB_COM_TRANSACTION2) {
 891                         /* POSIX lock. We send a NT_CANCEL SMB to cause the
 892                            blocking lock to return. */
 893
 894                         rc = send_nt_cancel(tcon, in_buf, midQ);
 895                         if (rc) {
 896                                 delete_mid(midQ);
 897                                 return rc;
 898                         }
 899                 } else {
 900                         /* Windows lock. We send a LOCKINGX_CANCEL_LOCK
 901                            to cause the blocking lock to return. */
 902
 903                         rc = send_lock_cancel(xid, tcon, in_buf, out_buf);
 904
 905                         /* If we get -ENOLCK back the lock may have
 906                            already been removed. Don't exit in this case. */
 907                         if (rc && rc != -ENOLCK) {
 908                                 delete_mid(midQ);
 909                                 return rc;
 910                         }
 911                 }
 912
 913                 if (wait_for_response(ses->server, midQ) == 0) {
 914                         /* We got the response - restart system call. */
 915                         rstart = 1;
 916                 }
 917         }
 918
 919         rc = sync_mid_result(midQ, ses->server);
 920         if (rc != 0)
 921                 return rc;
 922
 923         receive_len = midQ->resp_buf->smb_buf_length;
 924         if (receive_len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE) {
 925                 cERROR(1, "Frame too large received.  Length: %d  Xid: %d",
 926                         receive_len, xid);
 927                 rc = -EIO;
 928                 goto out;
 929         }
 930
 931         /* rcvd frame is ok */
 932
 933         if ((out_buf == NULL) || (midQ->midState != MID_RESPONSE_RECEIVED)) {
 934                 rc = -EIO;
 935                 cERROR(1, "Bad MID state?");
 936                 goto out;
 937         }
 938
 939         out_buf->smb_buf_length = receive_len;
 940         memcpy((char *)out_buf + 4,
 941                (char *)midQ->resp_buf + 4,
 942                receive_len);
 943
 944         dump_smb(out_buf, 92);
 945         /* convert the length into a more usable form */
 946         if ((receive_len > 24) &&
 947             (ses->server->secMode & (SECMODE_SIGN_REQUIRED |
 948                                      SECMODE_SIGN_ENABLED))) {
 949                 rc = cifs_verify_signature(out_buf,
 950                                            ses->server,
 951                                            midQ->sequence_number+1);
 952                 if (rc) {
 953                         cERROR(1, "Unexpected SMB signature");
 954                         /* BB FIXME add code to kill session */
 955                 }
 956         }
 957
 958         *pbytes_returned = out_buf->smb_buf_length;
 959
 960         /* BB special case reconnect tid and uid here? */
 961         rc = map_smb_to_linux_error(out_buf, 0 /* no log */ );
 962
 963         /* convert ByteCount if necessary */
 964         if (receive_len >= sizeof(struct smb_hdr) - 4
 965             /* do not count RFC1001 header */  +
 966             (2 * out_buf->WordCount) + 2 /* bcc */ )
 967                 BCC(out_buf) = le16_to_cpu(BCC_LE(out_buf));
 968
 969 out:
 970         delete_mid(midQ);
 971         if (rstart && rc == -EACCES)
 972                 return -ERESTARTSYS;
 973         return rc;
 974 }