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
 534         midQ->midState = MID_REQUEST_SUBMITTED;
 535 #ifdef CONFIG_CIFS_STATS2
 536         atomic_inc(&ses->server->inSend);
 537 #endif
 538         rc = smb_send2(ses->server, iov, n_vec,
 539                       (struct sockaddr *) &(ses->server->addr.sockAddr),
 540                        ses->server->noblocksnd);
 541 #ifdef CONFIG_CIFS_STATS2
 542         atomic_dec(&ses->server->inSend);
 543         midQ->when_sent = jiffies;
 544 #endif
 545
 546         mutex_unlock(&ses->server->srv_mutex);
 547         cifs_small_buf_release(in_buf);
 548
 549         if (rc < 0)
 550                 goto out;
 551
 552         if (long_op == CIFS_STD_OP)
 553                 timeout = 15 * HZ;
 554         else if (long_op == CIFS_VLONG_OP) /* e.g. slow writes past EOF */
 555                 timeout = 180 * HZ;
 556         else if (long_op == CIFS_LONG_OP)
 557                 timeout = 45 * HZ; /* should be greater than
 558                         servers oplock break timeout (about 43 seconds) */
 559         else if (long_op == CIFS_ASYNC_OP)
 560                 goto out;
 561         else if (long_op == CIFS_BLOCKING_OP)
 562                 timeout = 0x7FFFFFFF; /*  large, but not so large as to wrap */
 563         else {
 564                 cERROR(1, ("unknown timeout flag %d", long_op));
 565                 rc = -EIO;
 566                 goto out;
 567         }
 568
 569         /* wait for 15 seconds or until woken up due to response arriving or
 570            due to last connection to this server being unmounted */
 571         if (signal_pending(current)) {
 572                 /* if signal pending do not hold up user for full smb timeout
 573                 but we still give response a chance to complete */
 574                 timeout = 2 * HZ;
 575         }
 576
 577         /* No user interrupts in wait - wreaks havoc with performance */
 578         wait_for_response(ses, midQ, timeout, 10 * HZ);
 579
 580         spin_lock(&GlobalMid_Lock);
 581         if (midQ->resp_buf) {
 582                 spin_unlock(&GlobalMid_Lock);
 583                 receive_len = midQ->resp_buf->smb_buf_length;
 584         } else {
 585                 cERROR(1, ("No response to cmd %d mid %d",
 586                         midQ->command, midQ->mid));
 587                 if (midQ->midState == MID_REQUEST_SUBMITTED) {
 588                         if (ses->server->tcpStatus == CifsExiting)
 589                                 rc = -EHOSTDOWN;
 590                         else {
 591                                 ses->server->tcpStatus = CifsNeedReconnect;
 592                                 midQ->midState = MID_RETRY_NEEDED;
 593                         }
 594                 }
 595
 596                 if (rc != -EHOSTDOWN) {
 597                         if (midQ->midState == MID_RETRY_NEEDED) {
 598                                 rc = -EAGAIN;
 599                                 cFYI(1, ("marking request for retry"));
 600                         } else {
 601                                 rc = -EIO;
 602                         }
 603                 }
 604                 spin_unlock(&GlobalMid_Lock);
 605                 DeleteMidQEntry(midQ);
 606                 /* Update # of requests on wire to server */
 607                 atomic_dec(&ses->server->inFlight);
 608                 wake_up(&ses->server->request_q);
 609                 return rc;
 610         }
 611
 612         if (receive_len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE) {
 613                 cERROR(1, ("Frame too large received.  Length: %d  Xid: %d",
 614                         receive_len, xid));
 615                 rc = -EIO;
 616         } else {                /* rcvd frame is ok */
 617                 if (midQ->resp_buf &&
 618                         (midQ->midState == MID_RESPONSE_RECEIVED)) {
 619
 620                         iov[0].iov_base = (char *)midQ->resp_buf;
 621                         if (midQ->largeBuf)
 622                                 *pRespBufType = CIFS_LARGE_BUFFER;
 623                         else
 624                                 *pRespBufType = CIFS_SMALL_BUFFER;
 625                         iov[0].iov_len = receive_len + 4;
 626
 627                         dump_smb(midQ->resp_buf, 80);
 628                         /* convert the length into a more usable form */
 629                         if ((receive_len > 24) &&
 630                            (ses->server->secMode & (SECMODE_SIGN_REQUIRED |
 631                                         SECMODE_SIGN_ENABLED))) {
 632                                 rc = cifs_verify_signature(midQ->resp_buf,
 633                                                 &ses->server->mac_signing_key,
 634                                                 midQ->sequence_number+1);
 635                                 if (rc) {
 636                                         cERROR(1, ("Unexpected SMB signature"));
 637                                         /* BB FIXME add code to kill session */
 638                                 }
 639                         }
 640
 641                         /* BB special case reconnect tid and uid here? */
 642                         rc = map_smb_to_linux_error(midQ->resp_buf,
 643                                                 flags & CIFS_LOG_ERROR);
 644
 645                         /* convert ByteCount if necessary */
 646                         if (receive_len >= sizeof(struct smb_hdr) - 4
 647                             /* do not count RFC1001 header */  +
 648                             (2 * midQ->resp_buf->WordCount) + 2 /* bcc */ )
 649                                 BCC(midQ->resp_buf) =
 650                                         le16_to_cpu(BCC_LE(midQ->resp_buf));
 651                         if ((flags & CIFS_NO_RESP) == 0)
 652                                 midQ->resp_buf = NULL;  /* mark it so buf will
 653                                                            not be freed by
 654                                                            DeleteMidQEntry */
 655                 } else {
 656                         rc = -EIO;
 657                         cFYI(1, ("Bad MID state?"));
 658                 }
 659         }
 660
 661 out:
 662         DeleteMidQEntry(midQ);
 663         atomic_dec(&ses->server->inFlight);
 664         wake_up(&ses->server->request_q);
 665
 666         return rc;
 667 }
 668
 669 int
 670 SendReceive(const unsigned int xid, struct cifsSesInfo *ses,
 671             struct smb_hdr *in_buf, struct smb_hdr *out_buf,
 672             int *pbytes_returned, const int long_op)
 673 {
 674         int rc = 0;
 675         unsigned int receive_len;
 676         unsigned long timeout;
 677         struct mid_q_entry *midQ;
 678
 679         if (ses == NULL) {
 680                 cERROR(1, ("Null smb session"));
 681                 return -EIO;
 682         }
 683         if (ses->server == NULL) {
 684                 cERROR(1, ("Null tcp session"));
 685                 return -EIO;
 686         }
 687
 688         if (ses->server->tcpStatus == CifsExiting)
 689                 return -ENOENT;
 690
 691         /* Ensure that we do not send more than 50 overlapping requests
 692            to the same server. We may make this configurable later or
 693            use ses->maxReq */
 694
 695         if (in_buf->smb_buf_length > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) {
 696                 cERROR(1, ("Illegal length, greater than maximum frame, %d",
 697                            in_buf->smb_buf_length));
 698                 return -EIO;
 699         }
 700
 701         rc = wait_for_free_request(ses, long_op);
 702         if (rc)
 703                 return rc;
 704
 705         /* make sure that we sign in the same order that we send on this socket
 706            and avoid races inside tcp sendmsg code that could cause corruption
 707            of smb data */
 708
 709         mutex_lock(&ses->server->srv_mutex);
 710
 711         rc = allocate_mid(ses, in_buf, &midQ);
 712         if (rc) {
 713                 mutex_unlock(&ses->server->srv_mutex);
 714                 /* Update # of requests on wire to server */
 715                 atomic_dec(&ses->server->inFlight);
 716                 wake_up(&ses->server->request_q);
 717                 return rc;
 718         }
 719
 720         rc = cifs_sign_smb(in_buf, ses->server, &midQ->sequence_number);
 721
 722         midQ->midState = MID_REQUEST_SUBMITTED;
 723 #ifdef CONFIG_CIFS_STATS2
 724         atomic_inc(&ses->server->inSend);
 725 #endif
 726         rc = smb_send(ses->server->ssocket, in_buf, in_buf->smb_buf_length,
 727                       (struct sockaddr *) &(ses->server->addr.sockAddr),
 728                       ses->server->noblocksnd);
 729 #ifdef CONFIG_CIFS_STATS2
 730         atomic_dec(&ses->server->inSend);
 731         midQ->when_sent = jiffies;
 732 #endif
 733         mutex_unlock(&ses->server->srv_mutex);
 734
 735         if (rc < 0)
 736                 goto out;
 737
 738         if (long_op == CIFS_STD_OP)
 739                 timeout = 15 * HZ;
 740         /* wait for 15 seconds or until woken up due to response arriving or
 741            due to last connection to this server being unmounted */
 742         else if (long_op == CIFS_ASYNC_OP)
 743                 goto out;
 744         else if (long_op == CIFS_VLONG_OP) /* writes past EOF can be slow */
 745                 timeout = 180 * HZ;
 746         else if (long_op == CIFS_LONG_OP)
 747                 timeout = 45 * HZ; /* should be greater than
 748                         servers oplock break timeout (about 43 seconds) */
 749         else if (long_op == CIFS_BLOCKING_OP)
 750                 timeout = 0x7FFFFFFF; /* large but no so large as to wrap */
 751         else {
 752                 cERROR(1, ("unknown timeout flag %d", long_op));
 753                 rc = -EIO;
 754                 goto out;
 755         }
 756
 757         if (signal_pending(current)) {
 758                 /* if signal pending do not hold up user for full smb timeout
 759                 but we still give response a chance to complete */
 760                 timeout = 2 * HZ;
 761         }
 762
 763         /* No user interrupts in wait - wreaks havoc with performance */
 764         wait_for_response(ses, midQ, timeout, 10 * HZ);
 765
 766         spin_lock(&GlobalMid_Lock);
 767         if (midQ->resp_buf) {
 768                 spin_unlock(&GlobalMid_Lock);
 769                 receive_len = midQ->resp_buf->smb_buf_length;
 770         } else {
 771                 cERROR(1, ("No response for cmd %d mid %d",
 772                           midQ->command, midQ->mid));
 773                 if (midQ->midState == MID_REQUEST_SUBMITTED) {
 774                         if (ses->server->tcpStatus == CifsExiting)
 775                                 rc = -EHOSTDOWN;
 776                         else {
 777                                 ses->server->tcpStatus = CifsNeedReconnect;
 778                                 midQ->midState = MID_RETRY_NEEDED;
 779                         }
 780                 }
 781
 782                 if (rc != -EHOSTDOWN) {
 783                         if (midQ->midState == MID_RETRY_NEEDED) {
 784                                 rc = -EAGAIN;
 785                                 cFYI(1, ("marking request for retry"));
 786                         } else {
 787                                 rc = -EIO;
 788                         }
 789                 }
 790                 spin_unlock(&GlobalMid_Lock);
 791                 DeleteMidQEntry(midQ);
 792                 /* Update # of requests on wire to server */
 793                 atomic_dec(&ses->server->inFlight);
 794                 wake_up(&ses->server->request_q);
 795                 return rc;
 796         }
 797
 798         if (receive_len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE) {
 799                 cERROR(1, ("Frame too large received.  Length: %d  Xid: %d",
 800                         receive_len, xid));
 801                 rc = -EIO;
 802         } else {                /* rcvd frame is ok */
 803
 804                 if (midQ->resp_buf && out_buf
 805                     && (midQ->midState == MID_RESPONSE_RECEIVED)) {
 806                         out_buf->smb_buf_length = receive_len;
 807                         memcpy((char *)out_buf + 4,
 808                                (char *)midQ->resp_buf + 4,
 809                                receive_len);
 810
 811                         dump_smb(out_buf, 92);
 812                         /* convert the length into a more usable form */
 813                         if ((receive_len > 24) &&
 814                            (ses->server->secMode & (SECMODE_SIGN_REQUIRED |
 815                                         SECMODE_SIGN_ENABLED))) {
 816                                 rc = cifs_verify_signature(out_buf,
 817                                                 &ses->server->mac_signing_key,
 818                                                 midQ->sequence_number+1);
 819                                 if (rc) {
 820                                         cERROR(1, ("Unexpected SMB signature"));
 821                                         /* BB FIXME add code to kill session */
 822                                 }
 823                         }
 824
 825                         *pbytes_returned = out_buf->smb_buf_length;
 826
 827                         /* BB special case reconnect tid and uid here? */
 828                         rc = map_smb_to_linux_error(out_buf, 0 /* no log */ );
 829
 830                         /* convert ByteCount if necessary */
 831                         if (receive_len >= sizeof(struct smb_hdr) - 4
 832                             /* do not count RFC1001 header */  +
 833                             (2 * out_buf->WordCount) + 2 /* bcc */ )
 834                                 BCC(out_buf) = le16_to_cpu(BCC_LE(out_buf));
 835                 } else {
 836                         rc = -EIO;
 837                         cERROR(1, ("Bad MID state?"));
 838                 }
 839         }
 840
 841 out:
 842         DeleteMidQEntry(midQ);
 843         atomic_dec(&ses->server->inFlight);
 844         wake_up(&ses->server->request_q);
 845
 846         return rc;
 847 }
 848
 849 /* Send an NT_CANCEL SMB to cause the POSIX blocking lock to return. */
 850
 851 static int
 852 send_nt_cancel(struct cifsTconInfo *tcon, struct smb_hdr *in_buf,
 853                 struct mid_q_entry *midQ)
 854 {
 855         int rc = 0;
 856         struct cifsSesInfo *ses = tcon->ses;
 857         __u16 mid = in_buf->Mid;
 858
 859         header_assemble(in_buf, SMB_COM_NT_CANCEL, tcon, 0);
 860         in_buf->Mid = mid;
 861         mutex_lock(&ses->server->srv_mutex);
 862         rc = cifs_sign_smb(in_buf, ses->server, &midQ->sequence_number);
 863         if (rc) {
 864                 mutex_unlock(&ses->server->srv_mutex);
 865                 return rc;
 866         }
 867         rc = smb_send(ses->server->ssocket, in_buf, in_buf->smb_buf_length,
 868               (struct sockaddr *) &(ses->server->addr.sockAddr),
 869               ses->server->noblocksnd);
 870         mutex_unlock(&ses->server->srv_mutex);
 871         return rc;
 872 }
 873
 874 /* We send a LOCKINGX_CANCEL_LOCK to cause the Windows
 875    blocking lock to return. */
 876
 877 static int
 878 send_lock_cancel(const unsigned int xid, struct cifsTconInfo *tcon,
 879                         struct smb_hdr *in_buf,
 880                         struct smb_hdr *out_buf)
 881 {
 882         int bytes_returned;
 883         struct cifsSesInfo *ses = tcon->ses;
 884         LOCK_REQ *pSMB = (LOCK_REQ *)in_buf;
 885
 886         /* We just modify the current in_buf to change
 887            the type of lock from LOCKING_ANDX_SHARED_LOCK
 888            or LOCKING_ANDX_EXCLUSIVE_LOCK to
 889            LOCKING_ANDX_CANCEL_LOCK. */
 890
 891         pSMB->LockType = LOCKING_ANDX_CANCEL_LOCK|LOCKING_ANDX_LARGE_FILES;
 892         pSMB->Timeout = 0;
 893         pSMB->hdr.Mid = GetNextMid(ses->server);
 894
 895         return SendReceive(xid, ses, in_buf, out_buf,
 896                         &bytes_returned, CIFS_STD_OP);
 897 }
 898
 899 int
 900 SendReceiveBlockingLock(const unsigned int xid, struct cifsTconInfo *tcon,
 901             struct smb_hdr *in_buf, struct smb_hdr *out_buf,
 902             int *pbytes_returned)
 903 {
 904         int rc = 0;
 905         int rstart = 0;
 906         unsigned int receive_len;
 907         struct mid_q_entry *midQ;
 908         struct cifsSesInfo *ses;
 909
 910         if (tcon == NULL || tcon->ses == NULL) {
 911                 cERROR(1, ("Null smb session"));
 912                 return -EIO;
 913         }
 914         ses = tcon->ses;
 915
 916         if (ses->server == NULL) {
 917                 cERROR(1, ("Null tcp session"));
 918                 return -EIO;
 919         }
 920
 921         if (ses->server->tcpStatus == CifsExiting)
 922                 return -ENOENT;
 923
 924         /* Ensure that we do not send more than 50 overlapping requests
 925            to the same server. We may make this configurable later or
 926            use ses->maxReq */
 927
 928         if (in_buf->smb_buf_length > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) {
 929                 cERROR(1, ("Illegal length, greater than maximum frame, %d",
 930                            in_buf->smb_buf_length));
 931                 return -EIO;
 932         }
 933
 934         rc = wait_for_free_request(ses, CIFS_BLOCKING_OP);
 935         if (rc)
 936                 return rc;
 937
 938         /* make sure that we sign in the same order that we send on this socket
 939            and avoid races inside tcp sendmsg code that could cause corruption
 940            of smb data */
 941
 942         mutex_lock(&ses->server->srv_mutex);
 943
 944         rc = allocate_mid(ses, in_buf, &midQ);
 945         if (rc) {
 946                 mutex_unlock(&ses->server->srv_mutex);
 947                 return rc;
 948         }
 949
 950         rc = cifs_sign_smb(in_buf, ses->server, &midQ->sequence_number);
 951
 952         midQ->midState = MID_REQUEST_SUBMITTED;
 953 #ifdef CONFIG_CIFS_STATS2
 954         atomic_inc(&ses->server->inSend);
 955 #endif
 956         rc = smb_send(ses->server->ssocket, in_buf, in_buf->smb_buf_length,
 957                       (struct sockaddr *) &(ses->server->addr.sockAddr),
 958                       ses->server->noblocksnd);
 959 #ifdef CONFIG_CIFS_STATS2
 960         atomic_dec(&ses->server->inSend);
 961         midQ->when_sent = jiffies;
 962 #endif
 963         mutex_unlock(&ses->server->srv_mutex);
 964
 965         if (rc < 0) {
 966                 DeleteMidQEntry(midQ);
 967                 return rc;
 968         }
 969
 970         /* Wait for a reply - allow signals to interrupt. */
 971         rc = wait_event_interruptible(ses->server->response_q,
 972                 (!(midQ->midState == MID_REQUEST_SUBMITTED)) ||
 973                 ((ses->server->tcpStatus != CifsGood) &&
 974                  (ses->server->tcpStatus != CifsNew)));
 975
 976         /* Were we interrupted by a signal ? */
 977         if ((rc == -ERESTARTSYS) &&
 978                 (midQ->midState == MID_REQUEST_SUBMITTED) &&
 979                 ((ses->server->tcpStatus == CifsGood) ||
 980                  (ses->server->tcpStatus == CifsNew))) {
 981
 982                 if (in_buf->Command == SMB_COM_TRANSACTION2) {
 983                         /* POSIX lock. We send a NT_CANCEL SMB to cause the
 984                            blocking lock to return. */
 985
 986                         rc = send_nt_cancel(tcon, in_buf, midQ);
 987                         if (rc) {
 988                                 DeleteMidQEntry(midQ);
 989                                 return rc;
 990                         }
 991                 } else {
 992                         /* Windows lock. We send a LOCKINGX_CANCEL_LOCK
 993                            to cause the blocking lock to return. */
 994
 995                         rc = send_lock_cancel(xid, tcon, in_buf, out_buf);
 996
 997                         /* If we get -ENOLCK back the lock may have
 998                            already been removed. Don't exit in this case. */
 999                         if (rc && rc != -ENOLCK) {
1000                                 DeleteMidQEntry(midQ);
1001                                 return rc;
1002                         }
1003                 }
1004
1005                 /* Wait 5 seconds for the response. */
1006                 if (wait_for_response(ses, midQ, 5 * HZ, 5 * HZ) == 0) {
1007                         /* We got the response - restart system call. */
1008                         rstart = 1;
1009                 }
1010         }
1011
1012         spin_lock(&GlobalMid_Lock);
1013         if (midQ->resp_buf) {
1014                 spin_unlock(&GlobalMid_Lock);
1015                 receive_len = midQ->resp_buf->smb_buf_length;
1016         } else {
1017                 cERROR(1, ("No response for cmd %d mid %d",
1018                           midQ->command, midQ->mid));
1019                 if (midQ->midState == MID_REQUEST_SUBMITTED) {
1020                         if (ses->server->tcpStatus == CifsExiting)
1021                                 rc = -EHOSTDOWN;
1022                         else {
1023                                 ses->server->tcpStatus = CifsNeedReconnect;
1024                                 midQ->midState = MID_RETRY_NEEDED;
1025                         }
1026                 }
1027
1028                 if (rc != -EHOSTDOWN) {
1029                         if (midQ->midState == MID_RETRY_NEEDED) {
1030                                 rc = -EAGAIN;
1031                                 cFYI(1, ("marking request for retry"));
1032                         } else {
1033                                 rc = -EIO;
1034                         }
1035                 }
1036                 spin_unlock(&GlobalMid_Lock);
1037                 DeleteMidQEntry(midQ);
1038                 return rc;
1039         }
1040
1041         if (receive_len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE) {
1042                 cERROR(1, ("Frame too large received.  Length: %d  Xid: %d",
1043                         receive_len, xid));
1044                 rc = -EIO;
1045         } else {                /* rcvd frame is ok */
1046
1047                 if (midQ->resp_buf && out_buf
1048                     && (midQ->midState == MID_RESPONSE_RECEIVED)) {
1049                         out_buf->smb_buf_length = receive_len;
1050                         memcpy((char *)out_buf + 4,
1051                                (char *)midQ->resp_buf + 4,
1052                                receive_len);
1053
1054                         dump_smb(out_buf, 92);
1055                         /* convert the length into a more usable form */
1056                         if ((receive_len > 24) &&
1057                            (ses->server->secMode & (SECMODE_SIGN_REQUIRED |
1058                                         SECMODE_SIGN_ENABLED))) {
1059                                 rc = cifs_verify_signature(out_buf,
1060                                                 &ses->server->mac_signing_key,
1061                                                 midQ->sequence_number+1);
1062                                 if (rc) {
1063                                         cERROR(1, ("Unexpected SMB signature"));
1064                                         /* BB FIXME add code to kill session */
1065                                 }
1066                         }
1067
1068                         *pbytes_returned = out_buf->smb_buf_length;
1069
1070                         /* BB special case reconnect tid and uid here? */
1071                         rc = map_smb_to_linux_error(out_buf, 0 /* no log */ );
1072
1073                         /* convert ByteCount if necessary */
1074                         if (receive_len >= sizeof(struct smb_hdr) - 4
1075                             /* do not count RFC1001 header */  +
1076                             (2 * out_buf->WordCount) + 2 /* bcc */ )
1077                                 BCC(out_buf) = le16_to_cpu(BCC_LE(out_buf));
1078                 } else {
1079                         rc = -EIO;
1080                         cERROR(1, ("Bad MID state?"));
1081                 }
1082         }
1083         DeleteMidQEntry(midQ);
1084         if (rstart && rc == -EACCES)
1085                 return -ERESTARTSYS;
1086         return rc;
1087 }