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         } else {
 348                 spin_lock(&GlobalMid_Lock);
 349                 while (1) {
 350                         if (atomic_read(&ses->server->inFlight) >=
 351                                         cifs_max_pending){
 352                                 spin_unlock(&GlobalMid_Lock);
 353 #ifdef CONFIG_CIFS_STATS2
 354                                 atomic_inc(&ses->server->num_waiters);
 355 #endif
 356                                 wait_event(ses->server->request_q,
 357                                         atomic_read(&ses->server->inFlight)
 358                                          < cifs_max_pending);
 359 #ifdef CONFIG_CIFS_STATS2
 360                                 atomic_dec(&ses->server->num_waiters);
 361 #endif
 362                                 spin_lock(&GlobalMid_Lock);
 363                         } else {
 364                                 if (ses->server->tcpStatus == CifsExiting) {
 365                                         spin_unlock(&GlobalMid_Lock);
 366                                         return -ENOENT;
 367                                 }
 368
 369                                 /* can not count locking commands against total
 370                                    as they are allowed to block on server */
 371
 372                                 /* update # of requests on the wire to server */
 373                                 if (long_op != CIFS_BLOCKING_OP)
 374                                         atomic_inc(&ses->server->inFlight);
 375                                 spin_unlock(&GlobalMid_Lock);
 376                                 break;
 377                         }
 378                 }
 379         }
 380         return 0;
 381 }
 382
 383 static int allocate_mid(struct cifsSesInfo *ses, struct smb_hdr *in_buf,
 384                         struct mid_q_entry **ppmidQ)
 385 {
 386         if (ses->server->tcpStatus == CifsExiting) {
 387                 return -ENOENT;
 388         } else if (ses->server->tcpStatus == CifsNeedReconnect) {
 389                 cFYI(1, ("tcp session dead - return to caller to retry"));
 390                 return -EAGAIN;
 391         } else if (ses->status != CifsGood) {
 392                 /* check if SMB session is bad because we are setting it up */
 393                 if ((in_buf->Command != SMB_COM_SESSION_SETUP_ANDX) &&
 394                         (in_buf->Command != SMB_COM_NEGOTIATE))
 395                         return -EAGAIN;
 396                 /* else ok - we are setting up session */
 397         }
 398         *ppmidQ = AllocMidQEntry(in_buf, ses->server);
 399         if (*ppmidQ == NULL)
 400                 return -ENOMEM;
 401         return 0;
 402 }
 403
 404 static int wait_for_response(struct cifsSesInfo *ses,
 405                         struct mid_q_entry *midQ,
 406                         unsigned long timeout,
 407                         unsigned long time_to_wait)
 408 {
 409         unsigned long curr_timeout;
 410
 411         for (;;) {
 412                 curr_timeout = timeout + jiffies;
 413                 wait_event_timeout(ses->server->response_q,
 414                         midQ->midState != MID_REQUEST_SUBMITTED, timeout);
 415
 416                 if (time_after(jiffies, curr_timeout) &&
 417                         (midQ->midState == MID_REQUEST_SUBMITTED) &&
 418                         ((ses->server->tcpStatus == CifsGood) ||
 419                          (ses->server->tcpStatus == CifsNew))) {
 420
 421                         unsigned long lrt;
 422
 423                         /* We timed out. Is the server still
 424                            sending replies ? */
 425                         spin_lock(&GlobalMid_Lock);
 426                         lrt = ses->server->lstrp;
 427                         spin_unlock(&GlobalMid_Lock);
 428
 429                         /* Calculate time_to_wait past last receive time.
 430                          Although we prefer not to time out if the
 431                          server is still responding - we will time
 432                          out if the server takes more than 15 (or 45
 433                          or 180) seconds to respond to this request
 434                          and has not responded to any request from
 435                          other threads on the client within 10 seconds */
 436                         lrt += time_to_wait;
 437                         if (time_after(jiffies, lrt)) {
 438                                 /* No replies for time_to_wait. */
 439                                 cERROR(1, ("server not responding"));
 440                                 return -1;
 441                         }
 442                 } else {
 443                         return 0;
 444                 }
 445         }
 446 }
 447
 448
 449 /*
 450  *
 451  * Send an SMB Request.  No response info (other than return code)
 452  * needs to be parsed.
 453  *
 454  * flags indicate the type of request buffer and how long to wait
 455  * and whether to log NT STATUS code (error) before mapping it to POSIX error
 456  *
 457  */
 458 int
 459 SendReceiveNoRsp(const unsigned int xid, struct cifsSesInfo *ses,
 460                 struct smb_hdr *in_buf, int flags)
 461 {
 462         int rc;
 463         struct kvec iov[1];
 464         int resp_buf_type;
 465
 466         iov[0].iov_base = (char *)in_buf;
 467         iov[0].iov_len = in_buf->smb_buf_length + 4;
 468         flags |= CIFS_NO_RESP;
 469         rc = SendReceive2(xid, ses, iov, 1, &resp_buf_type, flags);
 470         cFYI(DBG2, ("SendRcvNoRsp flags %d rc %d", flags, rc));
 471
 472         return rc;
 473 }
 474
 475 int
 476 SendReceive2(const unsigned int xid, struct cifsSesInfo *ses,
 477              struct kvec *iov, int n_vec, int *pRespBufType /* ret */,
 478              const int flags)
 479 {
 480         int rc = 0;
 481         int long_op;
 482         unsigned int receive_len;
 483         unsigned long timeout;
 484         struct mid_q_entry *midQ;
 485         struct smb_hdr *in_buf = iov[0].iov_base;
 486
 487         long_op = flags & CIFS_TIMEOUT_MASK;
 488
 489         *pRespBufType = CIFS_NO_BUFFER;  /* no response buf yet */
 490
 491         if ((ses == NULL) || (ses->server == NULL)) {
 492                 cifs_small_buf_release(in_buf);
 493                 cERROR(1, ("Null session"));
 494                 return -EIO;
 495         }
 496
 497         if (ses->server->tcpStatus == CifsExiting) {
 498                 cifs_small_buf_release(in_buf);
 499                 return -ENOENT;
 500         }
 501
 502         /* Ensure that we do not send more than 50 overlapping requests
 503            to the same server. We may make this configurable later or
 504            use ses->maxReq */
 505
 506         rc = wait_for_free_request(ses, long_op);
 507         if (rc) {
 508                 cifs_small_buf_release(in_buf);
 509                 return rc;
 510         }
 511
 512         /* make sure that we sign in the same order that we send on this socket
 513            and avoid races inside tcp sendmsg code that could cause corruption
 514            of smb data */
 515
 516         mutex_lock(&ses->server->srv_mutex);
 517
 518         rc = allocate_mid(ses, in_buf, &midQ);
 519         if (rc) {
 520                 mutex_unlock(&ses->server->srv_mutex);
 521                 cifs_small_buf_release(in_buf);
 522                 /* Update # of requests on wire to server */
 523                 atomic_dec(&ses->server->inFlight);
 524                 wake_up(&ses->server->request_q);
 525                 return rc;
 526         }
 527         rc = cifs_sign_smb2(iov, n_vec, ses->server, &midQ->sequence_number);
 528
 529         midQ->midState = MID_REQUEST_SUBMITTED;
 530 #ifdef CONFIG_CIFS_STATS2
 531         atomic_inc(&ses->server->inSend);
 532 #endif
 533         rc = smb_send2(ses->server, iov, n_vec,
 534                       (struct sockaddr *) &(ses->server->addr.sockAddr),
 535                        ses->server->noblocksnd);
 536 #ifdef CONFIG_CIFS_STATS2
 537         atomic_dec(&ses->server->inSend);
 538         midQ->when_sent = jiffies;
 539 #endif
 540
 541         mutex_unlock(&ses->server->srv_mutex);
 542         cifs_small_buf_release(in_buf);
 543
 544         if (rc < 0)
 545                 goto out;
 546
 547         if (long_op == CIFS_STD_OP)
 548                 timeout = 15 * HZ;
 549         else if (long_op == CIFS_VLONG_OP) /* e.g. slow writes past EOF */
 550                 timeout = 180 * HZ;
 551         else if (long_op == CIFS_LONG_OP)
 552                 timeout = 45 * HZ; /* should be greater than
 553                         servers oplock break timeout (about 43 seconds) */
 554         else if (long_op == CIFS_ASYNC_OP)
 555                 goto out;
 556         else if (long_op == CIFS_BLOCKING_OP)
 557                 timeout = 0x7FFFFFFF; /*  large, but not so large as to wrap */
 558         else {
 559                 cERROR(1, ("unknown timeout flag %d", long_op));
 560                 rc = -EIO;
 561                 goto out;
 562         }
 563
 564         /* wait for 15 seconds or until woken up due to response arriving or
 565            due to last connection to this server being unmounted */
 566         if (signal_pending(current)) {
 567                 /* if signal pending do not hold up user for full smb timeout
 568                 but we still give response a chance to complete */
 569                 timeout = 2 * HZ;
 570         }
 571
 572         /* No user interrupts in wait - wreaks havoc with performance */
 573         wait_for_response(ses, midQ, timeout, 10 * HZ);
 574
 575         spin_lock(&GlobalMid_Lock);
 576         if (midQ->resp_buf) {
 577                 spin_unlock(&GlobalMid_Lock);
 578                 receive_len = midQ->resp_buf->smb_buf_length;
 579         } else {
 580                 cERROR(1, ("No response to cmd %d mid %d",
 581                         midQ->command, midQ->mid));
 582                 if (midQ->midState == MID_REQUEST_SUBMITTED) {
 583                         if (ses->server->tcpStatus == CifsExiting)
 584                                 rc = -EHOSTDOWN;
 585                         else {
 586                                 ses->server->tcpStatus = CifsNeedReconnect;
 587                                 midQ->midState = MID_RETRY_NEEDED;
 588                         }
 589                 }
 590
 591                 if (rc != -EHOSTDOWN) {
 592                         if (midQ->midState == MID_RETRY_NEEDED) {
 593                                 rc = -EAGAIN;
 594                                 cFYI(1, ("marking request for retry"));
 595                         } else {
 596                                 rc = -EIO;
 597                         }
 598                 }
 599                 spin_unlock(&GlobalMid_Lock);
 600                 DeleteMidQEntry(midQ);
 601                 /* Update # of requests on wire to server */
 602                 atomic_dec(&ses->server->inFlight);
 603                 wake_up(&ses->server->request_q);
 604                 return rc;
 605         }
 606
 607         if (receive_len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE) {
 608                 cERROR(1, ("Frame too large received.  Length: %d  Xid: %d",
 609                         receive_len, xid));
 610                 rc = -EIO;
 611         } else {                /* rcvd frame is ok */
 612                 if (midQ->resp_buf &&
 613                         (midQ->midState == MID_RESPONSE_RECEIVED)) {
 614
 615                         iov[0].iov_base = (char *)midQ->resp_buf;
 616                         if (midQ->largeBuf)
 617                                 *pRespBufType = CIFS_LARGE_BUFFER;
 618                         else
 619                                 *pRespBufType = CIFS_SMALL_BUFFER;
 620                         iov[0].iov_len = receive_len + 4;
 621
 622                         dump_smb(midQ->resp_buf, 80);
 623                         /* convert the length into a more usable form */
 624                         if ((receive_len > 24) &&
 625                            (ses->server->secMode & (SECMODE_SIGN_REQUIRED |
 626                                         SECMODE_SIGN_ENABLED))) {
 627                                 rc = cifs_verify_signature(midQ->resp_buf,
 628                                                 &ses->server->mac_signing_key,
 629                                                 midQ->sequence_number+1);
 630                                 if (rc) {
 631                                         cERROR(1, ("Unexpected SMB signature"));
 632                                         /* BB FIXME add code to kill session */
 633                                 }
 634                         }
 635
 636                         /* BB special case reconnect tid and uid here? */
 637                         rc = map_smb_to_linux_error(midQ->resp_buf,
 638                                                 flags & CIFS_LOG_ERROR);
 639
 640                         /* convert ByteCount if necessary */
 641                         if (receive_len >= sizeof(struct smb_hdr) - 4
 642                             /* do not count RFC1001 header */  +
 643                             (2 * midQ->resp_buf->WordCount) + 2 /* bcc */ )
 644                                 BCC(midQ->resp_buf) =
 645                                         le16_to_cpu(BCC_LE(midQ->resp_buf));
 646                         if ((flags & CIFS_NO_RESP) == 0)
 647                                 midQ->resp_buf = NULL;  /* mark it so buf will
 648                                                            not be freed by
 649                                                            DeleteMidQEntry */
 650                 } else {
 651                         rc = -EIO;
 652                         cFYI(1, ("Bad MID state?"));
 653                 }
 654         }
 655
 656 out:
 657         DeleteMidQEntry(midQ);
 658         atomic_dec(&ses->server->inFlight);
 659         wake_up(&ses->server->request_q);
 660
 661         return rc;
 662 }
 663
 664 int
 665 SendReceive(const unsigned int xid, struct cifsSesInfo *ses,
 666             struct smb_hdr *in_buf, struct smb_hdr *out_buf,
 667             int *pbytes_returned, const int long_op)
 668 {
 669         int rc = 0;
 670         unsigned int receive_len;
 671         unsigned long timeout;
 672         struct mid_q_entry *midQ;
 673
 674         if (ses == NULL) {
 675                 cERROR(1, ("Null smb session"));
 676                 return -EIO;
 677         }
 678         if (ses->server == NULL) {
 679                 cERROR(1, ("Null tcp session"));
 680                 return -EIO;
 681         }
 682
 683         if (ses->server->tcpStatus == CifsExiting)
 684                 return -ENOENT;
 685
 686         /* Ensure that we do not send more than 50 overlapping requests
 687            to the same server. We may make this configurable later or
 688            use ses->maxReq */
 689
 690         rc = wait_for_free_request(ses, long_op);
 691         if (rc)
 692                 return rc;
 693
 694         /* make sure that we sign in the same order that we send on this socket
 695            and avoid races inside tcp sendmsg code that could cause corruption
 696            of smb data */
 697
 698         mutex_lock(&ses->server->srv_mutex);
 699
 700         rc = allocate_mid(ses, in_buf, &midQ);
 701         if (rc) {
 702                 mutex_unlock(&ses->server->srv_mutex);
 703                 /* Update # of requests on wire to server */
 704                 atomic_dec(&ses->server->inFlight);
 705                 wake_up(&ses->server->request_q);
 706                 return rc;
 707         }
 708
 709         if (in_buf->smb_buf_length > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) {
 710                 cERROR(1, ("Illegal length, greater than maximum frame, %d",
 711                         in_buf->smb_buf_length));
 712                 DeleteMidQEntry(midQ);
 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 -EIO;
 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         rc = wait_for_free_request(ses, CIFS_BLOCKING_OP);
 929         if (rc)
 930                 return rc;
 931
 932         /* make sure that we sign in the same order that we send on this socket
 933            and avoid races inside tcp sendmsg code that could cause corruption
 934            of smb data */
 935
 936         mutex_lock(&ses->server->srv_mutex);
 937
 938         rc = allocate_mid(ses, in_buf, &midQ);
 939         if (rc) {
 940                 mutex_unlock(&ses->server->srv_mutex);
 941                 return rc;
 942         }
 943
 944         if (in_buf->smb_buf_length > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) {
 945                 mutex_unlock(&ses->server->srv_mutex);
 946                 cERROR(1, ("Illegal length, greater than maximum frame, %d",
 947                         in_buf->smb_buf_length));
 948                 DeleteMidQEntry(midQ);
 949                 return -EIO;
 950         }
 951
 952         rc = cifs_sign_smb(in_buf, ses->server, &midQ->sequence_number);
 953
 954         midQ->midState = MID_REQUEST_SUBMITTED;
 955 #ifdef CONFIG_CIFS_STATS2
 956         atomic_inc(&ses->server->inSend);
 957 #endif
 958         rc = smb_send(ses->server->ssocket, in_buf, in_buf->smb_buf_length,
 959                       (struct sockaddr *) &(ses->server->addr.sockAddr),
 960                       ses->server->noblocksnd);
 961 #ifdef CONFIG_CIFS_STATS2
 962         atomic_dec(&ses->server->inSend);
 963         midQ->when_sent = jiffies;
 964 #endif
 965         mutex_unlock(&ses->server->srv_mutex);
 966
 967         if (rc < 0) {
 968                 DeleteMidQEntry(midQ);
 969                 return rc;
 970         }
 971
 972         /* Wait for a reply - allow signals to interrupt. */
 973         rc = wait_event_interruptible(ses->server->response_q,
 974                 (!(midQ->midState == MID_REQUEST_SUBMITTED)) ||
 975                 ((ses->server->tcpStatus != CifsGood) &&
 976                  (ses->server->tcpStatus != CifsNew)));
 977
 978         /* Were we interrupted by a signal ? */
 979         if ((rc == -ERESTARTSYS) &&
 980                 (midQ->midState == MID_REQUEST_SUBMITTED) &&
 981                 ((ses->server->tcpStatus == CifsGood) ||
 982                  (ses->server->tcpStatus == CifsNew))) {
 983
 984                 if (in_buf->Command == SMB_COM_TRANSACTION2) {
 985                         /* POSIX lock. We send a NT_CANCEL SMB to cause the
 986                            blocking lock to return. */
 987
 988                         rc = send_nt_cancel(tcon, in_buf, midQ);
 989                         if (rc) {
 990                                 DeleteMidQEntry(midQ);
 991                                 return rc;
 992                         }
 993                 } else {
 994                         /* Windows lock. We send a LOCKINGX_CANCEL_LOCK
 995                            to cause the blocking lock to return. */
 996
 997                         rc = send_lock_cancel(xid, tcon, in_buf, out_buf);
 998
 999                         /* If we get -ENOLCK back the lock may have
1000                            already been removed. Don't exit in this case. */
1001                         if (rc && rc != -ENOLCK) {
1002                                 DeleteMidQEntry(midQ);
1003                                 return rc;
1004                         }
1005                 }
1006
1007                 /* Wait 5 seconds for the response. */
1008                 if (wait_for_response(ses, midQ, 5 * HZ, 5 * HZ) == 0) {
1009                         /* We got the response - restart system call. */
1010                         rstart = 1;
1011                 }
1012         }
1013
1014         spin_lock(&GlobalMid_Lock);
1015         if (midQ->resp_buf) {
1016                 spin_unlock(&GlobalMid_Lock);
1017                 receive_len = midQ->resp_buf->smb_buf_length;
1018         } else {
1019                 cERROR(1, ("No response for cmd %d mid %d",
1020                           midQ->command, midQ->mid));
1021                 if (midQ->midState == MID_REQUEST_SUBMITTED) {
1022                         if (ses->server->tcpStatus == CifsExiting)
1023                                 rc = -EHOSTDOWN;
1024                         else {
1025                                 ses->server->tcpStatus = CifsNeedReconnect;
1026                                 midQ->midState = MID_RETRY_NEEDED;
1027                         }
1028                 }
1029
1030                 if (rc != -EHOSTDOWN) {
1031                         if (midQ->midState == MID_RETRY_NEEDED) {
1032                                 rc = -EAGAIN;
1033                                 cFYI(1, ("marking request for retry"));
1034                         } else {
1035                                 rc = -EIO;
1036                         }
1037                 }
1038                 spin_unlock(&GlobalMid_Lock);
1039                 DeleteMidQEntry(midQ);
1040                 return rc;
1041         }
1042
1043         if (receive_len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE) {
1044                 cERROR(1, ("Frame too large received.  Length: %d  Xid: %d",
1045                         receive_len, xid));
1046                 rc = -EIO;
1047         } else {                /* rcvd frame is ok */
1048
1049                 if (midQ->resp_buf && out_buf
1050                     && (midQ->midState == MID_RESPONSE_RECEIVED)) {
1051                         out_buf->smb_buf_length = receive_len;
1052                         memcpy((char *)out_buf + 4,
1053                                (char *)midQ->resp_buf + 4,
1054                                receive_len);
1055
1056                         dump_smb(out_buf, 92);
1057                         /* convert the length into a more usable form */
1058                         if ((receive_len > 24) &&
1059                            (ses->server->secMode & (SECMODE_SIGN_REQUIRED |
1060                                         SECMODE_SIGN_ENABLED))) {
1061                                 rc = cifs_verify_signature(out_buf,
1062                                                 &ses->server->mac_signing_key,
1063                                                 midQ->sequence_number+1);
1064                                 if (rc) {
1065                                         cERROR(1, ("Unexpected SMB signature"));
1066                                         /* BB FIXME add code to kill session */
1067                                 }
1068                         }
1069
1070                         *pbytes_returned = out_buf->smb_buf_length;
1071
1072                         /* BB special case reconnect tid and uid here? */
1073                         rc = map_smb_to_linux_error(out_buf, 0 /* no log */ );
1074
1075                         /* convert ByteCount if necessary */
1076                         if (receive_len >= sizeof(struct smb_hdr) - 4
1077                             /* do not count RFC1001 header */  +
1078                             (2 * out_buf->WordCount) + 2 /* bcc */ )
1079                                 BCC(out_buf) = le16_to_cpu(BCC_LE(out_buf));
1080                 } else {
1081                         rc = -EIO;
1082                         cERROR(1, ("Bad MID state?"));
1083                 }
1084         }
1085         DeleteMidQEntry(midQ);
1086         if (rstart && rc == -EACCES)
1087                 return -ERESTARTSYS;
1088         return rc;
1089 }