fs/cifs/transport.c

   1 /*
   2  *   fs/cifs/transport.c
   3  *
   4  *   Copyright (C) International Business Machines  Corp., 2002,2005
   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 cifsSesInfo *ses)
  41 {
  42         struct mid_q_entry *temp;
  43
  44         if (ses == NULL) {
  45                 cERROR(1, ("Null session passed in to AllocMidQEntry"));
  46                 return NULL;
  47         }
  48         if (ses->server == NULL) {
  49                 cERROR(1, ("Null TCP session in AllocMidQEntry"));
  50                 return NULL;
  51         }
  52
  53         temp = (struct mid_q_entry *) mempool_alloc(cifs_mid_poolp,
  54                                                     GFP_KERNEL | GFP_NOFS);
  55         if (temp == NULL)
  56                 return temp;
  57         else {
  58                 memset(temp, 0, sizeof (struct mid_q_entry));
  59                 temp->mid = smb_buffer->Mid;    /* always LE */
  60                 temp->pid = current->pid;
  61                 temp->command = smb_buffer->Command;
  62                 cFYI(1, ("For smb_command %d", temp->command));
  63         /*      do_gettimeofday(&temp->when_sent);*/ /* easier to use jiffies */
  64                 /* when mid allocated can be before when sent */
  65                 temp->when_alloc = jiffies;
  66                 temp->ses = ses;
  67                 temp->tsk = current;
  68         }
  69
  70         spin_lock(&GlobalMid_Lock);
  71         list_add_tail(&temp->qhead, &ses->server->pending_mid_q);
  72         atomic_inc(&midCount);
  73         temp->midState = MID_REQUEST_ALLOCATED;
  74         spin_unlock(&GlobalMid_Lock);
  75         return temp;
  76 }
  77
  78 static void
  79 DeleteMidQEntry(struct mid_q_entry *midEntry)
  80 {
  81 #ifdef CONFIG_CIFS_STATS2
  82         unsigned long now;
  83 #endif
  84         spin_lock(&GlobalMid_Lock);
  85         midEntry->midState = MID_FREE;
  86         list_del(&midEntry->qhead);
  87         atomic_dec(&midCount);
  88         spin_unlock(&GlobalMid_Lock);
  89         if(midEntry->largeBuf)
  90                 cifs_buf_release(midEntry->resp_buf);
  91         else
  92                 cifs_small_buf_release(midEntry->resp_buf);
  93 #ifdef CONFIG_CIFS_STATS2
  94         now = jiffies;
  95         /* commands taking longer than one second are indications that
  96            something is wrong, unless it is quite a slow link or server */
  97         if((now - midEntry->when_alloc) > HZ) {
  98                 if((cifsFYI & CIFS_TIMER) &&
  99                    (midEntry->command != SMB_COM_LOCKING_ANDX)) {
 100                         printk(KERN_DEBUG " CIFS slow rsp: cmd %d mid %d",
 101                                midEntry->command, midEntry->mid);
 102                         printk(" A: 0x%lx S: 0x%lx R: 0x%lx\n",
 103                                now - midEntry->when_alloc,
 104                                now - midEntry->when_sent,
 105                                now - midEntry->when_received);
 106                 }
 107         }
 108 #endif
 109         mempool_free(midEntry, cifs_mid_poolp);
 110 }
 111
 112 struct oplock_q_entry *
 113 AllocOplockQEntry(struct inode * pinode, __u16 fid, struct cifsTconInfo * tcon)
 114 {
 115         struct oplock_q_entry *temp;
 116         if ((pinode== NULL) || (tcon == NULL)) {
 117                 cERROR(1, ("Null parms passed to AllocOplockQEntry"));
 118                 return NULL;
 119         }
 120         temp = (struct oplock_q_entry *) kmem_cache_alloc(cifs_oplock_cachep,
 121                                                        GFP_KERNEL);
 122         if (temp == NULL)
 123                 return temp;
 124         else {
 125                 temp->pinode = pinode;
 126                 temp->tcon = tcon;
 127                 temp->netfid = fid;
 128                 spin_lock(&GlobalMid_Lock);
 129                 list_add_tail(&temp->qhead, &GlobalOplock_Q);
 130                 spin_unlock(&GlobalMid_Lock);
 131         }
 132         return temp;
 133
 134 }
 135
 136 void DeleteOplockQEntry(struct oplock_q_entry * oplockEntry)
 137 {
 138         spin_lock(&GlobalMid_Lock);
 139     /* should we check if list empty first? */
 140         list_del(&oplockEntry->qhead);
 141         spin_unlock(&GlobalMid_Lock);
 142         kmem_cache_free(cifs_oplock_cachep, oplockEntry);
 143 }
 144
 145 int
 146 smb_send(struct socket *ssocket, struct smb_hdr *smb_buffer,
 147          unsigned int smb_buf_length, struct sockaddr *sin)
 148 {
 149         int rc = 0;
 150         int i = 0;
 151         struct msghdr smb_msg;
 152         struct kvec iov;
 153         unsigned len = smb_buf_length + 4;
 154
 155         if(ssocket == NULL)
 156                 return -ENOTSOCK; /* BB eventually add reconnect code here */
 157         iov.iov_base = smb_buffer;
 158         iov.iov_len = len;
 159
 160         smb_msg.msg_name = sin;
 161         smb_msg.msg_namelen = sizeof (struct sockaddr);
 162         smb_msg.msg_control = NULL;
 163         smb_msg.msg_controllen = 0;
 164         smb_msg.msg_flags = MSG_DONTWAIT + MSG_NOSIGNAL; /* BB add more flags?*/
 165
 166         /* smb header is converted in header_assemble. bcc and rest of SMB word
 167            area, and byte area if necessary, is converted to littleendian in
 168            cifssmb.c and RFC1001 len is converted to bigendian in smb_send
 169            Flags2 is converted in SendReceive */
 170
 171         smb_buffer->smb_buf_length = cpu_to_be32(smb_buffer->smb_buf_length);
 172         cFYI(1, ("Sending smb of length %d", smb_buf_length));
 173         dump_smb(smb_buffer, len);
 174
 175         while (len > 0) {
 176                 rc = kernel_sendmsg(ssocket, &smb_msg, &iov, 1, len);
 177                 if ((rc == -ENOSPC) || (rc == -EAGAIN)) {
 178                         i++;
 179                 /* smaller timeout here than send2 since smaller size */
 180                 /* Although it may not be required, this also is smaller
 181                    oplock break time */
 182                         if(i > 12) {
 183                                 cERROR(1,
 184                                    ("sends on sock %p stuck for 7 seconds",
 185                                     ssocket));
 186                                 rc = -EAGAIN;
 187                                 break;
 188                         }
 189                         msleep(1 << i);
 190                         continue;
 191                 }
 192                 if (rc < 0)
 193                         break;
 194                 else
 195                         i = 0; /* reset i after each successful send */
 196                 iov.iov_base += rc;
 197                 iov.iov_len -= rc;
 198                 len -= rc;
 199         }
 200
 201         if (rc < 0) {
 202                 cERROR(1,("Error %d sending data on socket to server", rc));
 203         } else {
 204                 rc = 0;
 205         }
 206
 207         /* Don't want to modify the buffer as a
 208            side effect of this call. */
 209         smb_buffer->smb_buf_length = smb_buf_length;
 210
 211         return rc;
 212 }
 213
 214 static int
 215 smb_send2(struct socket *ssocket, struct kvec *iov, int n_vec,
 216           struct sockaddr *sin)
 217 {
 218         int rc = 0;
 219         int i = 0;
 220         struct msghdr smb_msg;
 221         struct smb_hdr *smb_buffer = iov[0].iov_base;
 222         unsigned int len = iov[0].iov_len;
 223         unsigned int total_len;
 224         int first_vec = 0;
 225         unsigned int smb_buf_length = smb_buffer->smb_buf_length;
 226
 227         if(ssocket == NULL)
 228                 return -ENOTSOCK; /* BB eventually add reconnect code here */
 229
 230         smb_msg.msg_name = sin;
 231         smb_msg.msg_namelen = sizeof (struct sockaddr);
 232         smb_msg.msg_control = NULL;
 233         smb_msg.msg_controllen = 0;
 234         smb_msg.msg_flags = MSG_DONTWAIT + MSG_NOSIGNAL; /* BB add more flags?*/
 235
 236         /* smb header is converted in header_assemble. bcc and rest of SMB word
 237            area, and byte area if necessary, is converted to littleendian in
 238            cifssmb.c and RFC1001 len is converted to bigendian in smb_send
 239            Flags2 is converted in SendReceive */
 240
 241
 242         total_len = 0;
 243         for (i = 0; i < n_vec; i++)
 244                 total_len += iov[i].iov_len;
 245
 246         smb_buffer->smb_buf_length = cpu_to_be32(smb_buffer->smb_buf_length);
 247         cFYI(1, ("Sending smb:  total_len %d", total_len));
 248         dump_smb(smb_buffer, len);
 249
 250         while (total_len) {
 251                 rc = kernel_sendmsg(ssocket, &smb_msg, &iov[first_vec],
 252                                     n_vec - first_vec, total_len);
 253                 if ((rc == -ENOSPC) || (rc == -EAGAIN)) {
 254                         i++;
 255                         if(i >= 14) {
 256                                 cERROR(1,
 257                                    ("sends on sock %p stuck for 15 seconds",
 258                                     ssocket));
 259                                 rc = -EAGAIN;
 260                                 break;
 261                         }
 262                         msleep(1 << i);
 263                         continue;
 264                 }
 265                 if (rc < 0)
 266                         break;
 267
 268                 if (rc >= total_len) {
 269                         WARN_ON(rc > total_len);
 270                         break;
 271                 }
 272                 if(rc == 0) {
 273                         /* should never happen, letting socket clear before
 274                            retrying is our only obvious option here */
 275                         cERROR(1,("tcp sent no data"));
 276                         msleep(500);
 277                         continue;
 278                 }
 279                 total_len -= rc;
 280                 /* the line below resets i */
 281                 for (i = first_vec; i < n_vec; i++) {
 282                         if (iov[i].iov_len) {
 283                                 if (rc > iov[i].iov_len) {
 284                                         rc -= iov[i].iov_len;
 285                                         iov[i].iov_len = 0;
 286                                 } else {
 287                                         iov[i].iov_base += rc;
 288                                         iov[i].iov_len -= rc;
 289                                         first_vec = i;
 290                                         break;
 291                                 }
 292                         }
 293                 }
 294                 i = 0; /* in case we get ENOSPC on the next send */
 295         }
 296
 297         if (rc < 0) {
 298                 cERROR(1,("Error %d sending data on socket to server", rc));
 299         } else
 300                 rc = 0;
 301
 302         /* Don't want to modify the buffer as a
 303            side effect of this call. */
 304         smb_buffer->smb_buf_length = smb_buf_length;
 305
 306         return rc;
 307 }
 308
 309 static int wait_for_free_request(struct cifsSesInfo *ses, const int long_op)
 310 {
 311         if(long_op == -1) {
 312                 /* oplock breaks must not be held up */
 313                 atomic_inc(&ses->server->inFlight);
 314         } else {
 315                 spin_lock(&GlobalMid_Lock);
 316                 while(1) {
 317                         if(atomic_read(&ses->server->inFlight) >=
 318                                         cifs_max_pending){
 319                                 spin_unlock(&GlobalMid_Lock);
 320 #ifdef CONFIG_CIFS_STATS2
 321                                 atomic_inc(&ses->server->num_waiters);
 322 #endif
 323                                 wait_event(ses->server->request_q,
 324                                         atomic_read(&ses->server->inFlight)
 325                                          < cifs_max_pending);
 326 #ifdef CONFIG_CIFS_STATS2
 327                                 atomic_dec(&ses->server->num_waiters);
 328 #endif
 329                                 spin_lock(&GlobalMid_Lock);
 330                         } else {
 331                                 if(ses->server->tcpStatus == CifsExiting) {
 332                                         spin_unlock(&GlobalMid_Lock);
 333                                         return -ENOENT;
 334                                 }
 335
 336                                 /* can not count locking commands against total since
 337                                    they are allowed to block on server */
 338
 339                                 /* update # of requests on the wire to server */
 340                                 if (long_op < 3)
 341                                         atomic_inc(&ses->server->inFlight);
 342                                 spin_unlock(&GlobalMid_Lock);
 343                                 break;
 344                         }
 345                 }
 346         }
 347         return 0;
 348 }
 349
 350 static int allocate_mid(struct cifsSesInfo *ses, struct smb_hdr *in_buf,
 351                         struct mid_q_entry **ppmidQ)
 352 {
 353         if (ses->server->tcpStatus == CifsExiting) {
 354                 return -ENOENT;
 355         } else if (ses->server->tcpStatus == CifsNeedReconnect) {
 356                 cFYI(1,("tcp session dead - return to caller to retry"));
 357                 return -EAGAIN;
 358         } else if (ses->status != CifsGood) {
 359                 /* check if SMB session is bad because we are setting it up */
 360                 if((in_buf->Command != SMB_COM_SESSION_SETUP_ANDX) &&
 361                         (in_buf->Command != SMB_COM_NEGOTIATE)) {
 362                         return -EAGAIN;
 363                 } /* else ok - we are setting up session */
 364         }
 365         *ppmidQ = AllocMidQEntry(in_buf, ses);
 366         if (*ppmidQ == NULL) {
 367                 return -ENOMEM;
 368         }
 369         return 0;
 370 }
 371
 372 static int wait_for_response(struct cifsSesInfo *ses,
 373                         struct mid_q_entry *midQ,
 374                         unsigned long timeout,
 375                         unsigned long time_to_wait)
 376 {
 377         unsigned long curr_timeout;
 378
 379         for (;;) {
 380                 curr_timeout = timeout + jiffies;
 381                 wait_event(ses->server->response_q,
 382                         (!(midQ->midState == MID_REQUEST_SUBMITTED)) ||
 383                         time_after(jiffies, curr_timeout) ||
 384                         ((ses->server->tcpStatus != CifsGood) &&
 385                          (ses->server->tcpStatus != CifsNew)));
 386
 387                 if (time_after(jiffies, curr_timeout) &&
 388                         (midQ->midState == MID_REQUEST_SUBMITTED) &&
 389                         ((ses->server->tcpStatus == CifsGood) ||
 390                          (ses->server->tcpStatus == CifsNew))) {
 391
 392                         unsigned long lrt;
 393
 394                         /* We timed out. Is the server still
 395                            sending replies ? */
 396                         spin_lock(&GlobalMid_Lock);
 397                         lrt = ses->server->lstrp;
 398                         spin_unlock(&GlobalMid_Lock);
 399
 400                         /* Calculate time_to_wait past last receive time.
 401                          Although we prefer not to time out if the
 402                          server is still responding - we will time
 403                          out if the server takes more than 15 (or 45
 404                          or 180) seconds to respond to this request
 405                          and has not responded to any request from
 406                          other threads on the client within 10 seconds */
 407                         lrt += time_to_wait;
 408                         if (time_after(jiffies, lrt)) {
 409                                 /* No replies for time_to_wait. */
 410                                 cERROR(1,("server not responding"));
 411                                 return -1;
 412                         }
 413                 } else {
 414                         return 0;
 415                 }
 416         }
 417 }
 418
 419 int
 420 SendReceive2(const unsigned int xid, struct cifsSesInfo *ses,
 421              struct kvec *iov, int n_vec, int * pRespBufType /* ret */,
 422              const int long_op)
 423 {
 424         int rc = 0;
 425         unsigned int receive_len;
 426         unsigned long timeout;
 427         struct mid_q_entry *midQ;
 428         struct smb_hdr *in_buf = iov[0].iov_base;
 429
 430         *pRespBufType = CIFS_NO_BUFFER;  /* no response buf yet */
 431
 432         if ((ses == NULL) || (ses->server == NULL)) {
 433                 cifs_small_buf_release(in_buf);
 434                 cERROR(1,("Null session"));
 435                 return -EIO;
 436         }
 437
 438         if(ses->server->tcpStatus == CifsExiting) {
 439                 cifs_small_buf_release(in_buf);
 440                 return -ENOENT;
 441         }
 442
 443         /* Ensure that we do not send more than 50 overlapping requests
 444            to the same server. We may make this configurable later or
 445            use ses->maxReq */
 446
 447         rc = wait_for_free_request(ses, long_op);
 448         if (rc) {
 449                 cifs_small_buf_release(in_buf);
 450                 return rc;
 451         }
 452
 453         /* make sure that we sign in the same order that we send on this socket
 454            and avoid races inside tcp sendmsg code that could cause corruption
 455            of smb data */
 456
 457         down(&ses->server->tcpSem);
 458
 459         rc = allocate_mid(ses, in_buf, &midQ);
 460         if (rc) {
 461                 up(&ses->server->tcpSem);
 462                 cifs_small_buf_release(in_buf);
 463                 /* Update # of requests on wire to server */
 464                 atomic_dec(&ses->server->inFlight);
 465                 wake_up(&ses->server->request_q);
 466                 return rc;
 467         }
 468
 469         rc = cifs_sign_smb2(iov, n_vec, ses->server, &midQ->sequence_number);
 470
 471         midQ->midState = MID_REQUEST_SUBMITTED;
 472 #ifdef CONFIG_CIFS_STATS2
 473         atomic_inc(&ses->server->inSend);
 474 #endif
 475         rc = smb_send2(ses->server->ssocket, iov, n_vec,
 476                       (struct sockaddr *) &(ses->server->addr.sockAddr));
 477 #ifdef CONFIG_CIFS_STATS2
 478         atomic_dec(&ses->server->inSend);
 479         midQ->when_sent = jiffies;
 480 #endif
 481
 482         up(&ses->server->tcpSem);
 483         cifs_small_buf_release(in_buf);
 484
 485         if(rc < 0)
 486                 goto out;
 487
 488         if (long_op == -1)
 489                 goto out;
 490         else if (long_op == 2) /* writes past end of file can take loong time */
 491                 timeout = 180 * HZ;
 492         else if (long_op == 1)
 493                 timeout = 45 * HZ; /* should be greater than
 494                         servers oplock break timeout (about 43 seconds) */
 495         else
 496                 timeout = 15 * HZ;
 497
 498         /* wait for 15 seconds or until woken up due to response arriving or
 499            due to last connection to this server being unmounted */
 500         if (signal_pending(current)) {
 501                 /* if signal pending do not hold up user for full smb timeout
 502                 but we still give response a change to complete */
 503                 timeout = 2 * HZ;
 504         }
 505
 506         /* No user interrupts in wait - wreaks havoc with performance */
 507         wait_for_response(ses, midQ, timeout, 10 * HZ);
 508
 509         spin_lock(&GlobalMid_Lock);
 510         if (midQ->resp_buf) {
 511                 spin_unlock(&GlobalMid_Lock);
 512                 receive_len = midQ->resp_buf->smb_buf_length;
 513         } else {
 514                 cERROR(1,("No response to cmd %d mid %d",
 515                         midQ->command, midQ->mid));
 516                 if(midQ->midState == MID_REQUEST_SUBMITTED) {
 517                         if(ses->server->tcpStatus == CifsExiting)
 518                                 rc = -EHOSTDOWN;
 519                         else {
 520                                 ses->server->tcpStatus = CifsNeedReconnect;
 521                                 midQ->midState = MID_RETRY_NEEDED;
 522                         }
 523                 }
 524
 525                 if (rc != -EHOSTDOWN) {
 526                         if(midQ->midState == MID_RETRY_NEEDED) {
 527                                 rc = -EAGAIN;
 528                                 cFYI(1,("marking request for retry"));
 529                         } else {
 530                                 rc = -EIO;
 531                         }
 532                 }
 533                 spin_unlock(&GlobalMid_Lock);
 534                 DeleteMidQEntry(midQ);
 535                 /* Update # of requests on wire to server */
 536                 atomic_dec(&ses->server->inFlight);
 537                 wake_up(&ses->server->request_q);
 538                 return rc;
 539         }
 540
 541         if (receive_len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE) {
 542                 cERROR(1, ("Frame too large received.  Length: %d  Xid: %d",
 543                         receive_len, xid));
 544                 rc = -EIO;
 545         } else {                /* rcvd frame is ok */
 546                 if (midQ->resp_buf &&
 547                         (midQ->midState == MID_RESPONSE_RECEIVED)) {
 548
 549                         iov[0].iov_base = (char *)midQ->resp_buf;
 550                         if(midQ->largeBuf)
 551                                 *pRespBufType = CIFS_LARGE_BUFFER;
 552                         else
 553                                 *pRespBufType = CIFS_SMALL_BUFFER;
 554                         iov[0].iov_len = receive_len + 4;
 555
 556                         dump_smb(midQ->resp_buf, 80);
 557                         /* convert the length into a more usable form */
 558                         if((receive_len > 24) &&
 559                            (ses->server->secMode & (SECMODE_SIGN_REQUIRED |
 560                                         SECMODE_SIGN_ENABLED))) {
 561                                 rc = cifs_verify_signature(midQ->resp_buf,
 562                                                 ses->server->mac_signing_key,
 563                                                 midQ->sequence_number+1);
 564                                 if(rc) {
 565                                         cERROR(1,("Unexpected SMB signature"));
 566                                         /* BB FIXME add code to kill session */
 567                                 }
 568                         }
 569
 570                         /* BB special case reconnect tid and uid here? */
 571                         /* BB special case Errbadpassword and pwdexpired here */
 572                         rc = map_smb_to_linux_error(midQ->resp_buf);
 573
 574                         /* convert ByteCount if necessary */
 575                         if (receive_len >=
 576                             sizeof (struct smb_hdr) -
 577                             4 /* do not count RFC1001 header */  +
 578                             (2 * midQ->resp_buf->WordCount) + 2 /* bcc */ )
 579                                 BCC(midQ->resp_buf) =
 580                                         le16_to_cpu(BCC_LE(midQ->resp_buf));
 581                         midQ->resp_buf = NULL;  /* mark it so will not be freed
 582                                                 by DeleteMidQEntry */
 583                 } else {
 584                         rc = -EIO;
 585                         cFYI(1,("Bad MID state?"));
 586                 }
 587         }
 588
 589 out:
 590
 591         DeleteMidQEntry(midQ);
 592         atomic_dec(&ses->server->inFlight);
 593         wake_up(&ses->server->request_q);
 594
 595         return rc;
 596 }
 597
 598 int
 599 SendReceive(const unsigned int xid, struct cifsSesInfo *ses,
 600             struct smb_hdr *in_buf, struct smb_hdr *out_buf,
 601             int *pbytes_returned, const int long_op)
 602 {
 603         int rc = 0;
 604         unsigned int receive_len;
 605         unsigned long timeout;
 606         struct mid_q_entry *midQ;
 607
 608         if (ses == NULL) {
 609                 cERROR(1,("Null smb session"));
 610                 return -EIO;
 611         }
 612         if(ses->server == NULL) {
 613                 cERROR(1,("Null tcp session"));
 614                 return -EIO;
 615         }
 616
 617         if(ses->server->tcpStatus == CifsExiting)
 618                 return -ENOENT;
 619
 620         /* Ensure that we do not send more than 50 overlapping requests
 621            to the same server. We may make this configurable later or
 622            use ses->maxReq */
 623
 624         rc = wait_for_free_request(ses, long_op);
 625         if (rc)
 626                 return rc;
 627
 628         /* make sure that we sign in the same order that we send on this socket
 629            and avoid races inside tcp sendmsg code that could cause corruption
 630            of smb data */
 631
 632         down(&ses->server->tcpSem);
 633
 634         rc = allocate_mid(ses, in_buf, &midQ);
 635         if (rc) {
 636                 up(&ses->server->tcpSem);
 637                 /* Update # of requests on wire to server */
 638                 atomic_dec(&ses->server->inFlight);
 639                 wake_up(&ses->server->request_q);
 640                 return rc;
 641         }
 642
 643         if (in_buf->smb_buf_length > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) {
 644                 cERROR(1, ("Illegal length, greater than maximum frame, %d",
 645                         in_buf->smb_buf_length));
 646                 DeleteMidQEntry(midQ);
 647                 up(&ses->server->tcpSem);
 648                 /* Update # of requests on wire to server */
 649                 atomic_dec(&ses->server->inFlight);
 650                 wake_up(&ses->server->request_q);
 651                 return -EIO;
 652         }
 653
 654         rc = cifs_sign_smb(in_buf, ses->server, &midQ->sequence_number);
 655
 656         midQ->midState = MID_REQUEST_SUBMITTED;
 657 #ifdef CONFIG_CIFS_STATS2
 658         atomic_inc(&ses->server->inSend);
 659 #endif
 660         rc = smb_send(ses->server->ssocket, in_buf, in_buf->smb_buf_length,
 661                       (struct sockaddr *) &(ses->server->addr.sockAddr));
 662 #ifdef CONFIG_CIFS_STATS2
 663         atomic_dec(&ses->server->inSend);
 664         midQ->when_sent = jiffies;
 665 #endif
 666         up(&ses->server->tcpSem);
 667
 668         if(rc < 0)
 669                 goto out;
 670
 671         if (long_op == -1)
 672                 goto out;
 673         else if (long_op == 2) /* writes past end of file can take loong time */
 674                 timeout = 180 * HZ;
 675         else if (long_op == 1)
 676                 timeout = 45 * HZ; /* should be greater than
 677                         servers oplock break timeout (about 43 seconds) */
 678         else
 679                 timeout = 15 * HZ;
 680         /* wait for 15 seconds or until woken up due to response arriving or
 681            due to last connection to this server being unmounted */
 682         if (signal_pending(current)) {
 683                 /* if signal pending do not hold up user for full smb timeout
 684                 but we still give response a change to complete */
 685                 timeout = 2 * HZ;
 686         }
 687
 688         /* No user interrupts in wait - wreaks havoc with performance */
 689         wait_for_response(ses, midQ, timeout, 10 * HZ);
 690
 691         spin_lock(&GlobalMid_Lock);
 692         if (midQ->resp_buf) {
 693                 spin_unlock(&GlobalMid_Lock);
 694                 receive_len = midQ->resp_buf->smb_buf_length;
 695         } else {
 696                 cERROR(1,("No response for cmd %d mid %d",
 697                           midQ->command, midQ->mid));
 698                 if(midQ->midState == MID_REQUEST_SUBMITTED) {
 699                         if(ses->server->tcpStatus == CifsExiting)
 700                                 rc = -EHOSTDOWN;
 701                         else {
 702                                 ses->server->tcpStatus = CifsNeedReconnect;
 703                                 midQ->midState = MID_RETRY_NEEDED;
 704                         }
 705                 }
 706
 707                 if (rc != -EHOSTDOWN) {
 708                         if(midQ->midState == MID_RETRY_NEEDED) {
 709                                 rc = -EAGAIN;
 710                                 cFYI(1,("marking request for retry"));
 711                         } else {
 712                                 rc = -EIO;
 713                         }
 714                 }
 715                 spin_unlock(&GlobalMid_Lock);
 716                 DeleteMidQEntry(midQ);
 717                 /* Update # of requests on wire to server */
 718                 atomic_dec(&ses->server->inFlight);
 719                 wake_up(&ses->server->request_q);
 720                 return rc;
 721         }
 722
 723         if (receive_len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE) {
 724                 cERROR(1, ("Frame too large received.  Length: %d  Xid: %d",
 725                         receive_len, xid));
 726                 rc = -EIO;
 727         } else {                /* rcvd frame is ok */
 728
 729                 if (midQ->resp_buf && out_buf
 730                     && (midQ->midState == MID_RESPONSE_RECEIVED)) {
 731                         out_buf->smb_buf_length = receive_len;
 732                         memcpy((char *)out_buf + 4,
 733                                (char *)midQ->resp_buf + 4,
 734                                receive_len);
 735
 736                         dump_smb(out_buf, 92);
 737                         /* convert the length into a more usable form */
 738                         if((receive_len > 24) &&
 739                            (ses->server->secMode & (SECMODE_SIGN_REQUIRED |
 740                                         SECMODE_SIGN_ENABLED))) {
 741                                 rc = cifs_verify_signature(out_buf,
 742                                                 ses->server->mac_signing_key,
 743                                                 midQ->sequence_number+1);
 744                                 if(rc) {
 745                                         cERROR(1,("Unexpected SMB signature"));
 746                                         /* BB FIXME add code to kill session */
 747                                 }
 748                         }
 749
 750                         *pbytes_returned = out_buf->smb_buf_length;
 751
 752                         /* BB special case reconnect tid and uid here? */
 753                         rc = map_smb_to_linux_error(out_buf);
 754
 755                         /* convert ByteCount if necessary */
 756                         if (receive_len >=
 757                             sizeof (struct smb_hdr) -
 758                             4 /* do not count RFC1001 header */  +
 759                             (2 * out_buf->WordCount) + 2 /* bcc */ )
 760                                 BCC(out_buf) = le16_to_cpu(BCC_LE(out_buf));
 761                 } else {
 762                         rc = -EIO;
 763                         cERROR(1,("Bad MID state?"));
 764                 }
 765         }
 766
 767 out:
 768
 769         DeleteMidQEntry(midQ);
 770         atomic_dec(&ses->server->inFlight);
 771         wake_up(&ses->server->request_q);
 772
 773         return rc;
 774 }
 775
 776 /* Send an NT_CANCEL SMB to cause the POSIX blocking lock to return. */
 777
 778 static int
 779 send_nt_cancel(struct cifsTconInfo *tcon, struct smb_hdr *in_buf,
 780                 struct mid_q_entry *midQ)
 781 {
 782         int rc = 0;
 783         struct cifsSesInfo *ses = tcon->ses;
 784         __u16 mid = in_buf->Mid;
 785
 786         header_assemble(in_buf, SMB_COM_NT_CANCEL, tcon, 0);
 787         in_buf->Mid = mid;
 788         down(&ses->server->tcpSem);
 789         rc = cifs_sign_smb(in_buf, ses->server, &midQ->sequence_number);
 790         if (rc) {
 791                 up(&ses->server->tcpSem);
 792                 return rc;
 793         }
 794         rc = smb_send(ses->server->ssocket, in_buf, in_buf->smb_buf_length,
 795               (struct sockaddr *) &(ses->server->addr.sockAddr));
 796         up(&ses->server->tcpSem);
 797         return rc;
 798 }
 799
 800 /* We send a LOCKINGX_CANCEL_LOCK to cause the Windows
 801    blocking lock to return. */
 802
 803 static int
 804 send_lock_cancel(const unsigned int xid, struct cifsTconInfo *tcon,
 805                         struct smb_hdr *in_buf,
 806                         struct smb_hdr *out_buf)
 807 {
 808         int bytes_returned;
 809         struct cifsSesInfo *ses = tcon->ses;
 810         LOCK_REQ *pSMB = (LOCK_REQ *)in_buf;
 811
 812         /* We just modify the current in_buf to change
 813            the type of lock from LOCKING_ANDX_SHARED_LOCK
 814            or LOCKING_ANDX_EXCLUSIVE_LOCK to
 815            LOCKING_ANDX_CANCEL_LOCK. */
 816
 817         pSMB->LockType = LOCKING_ANDX_CANCEL_LOCK|LOCKING_ANDX_LARGE_FILES;
 818         pSMB->Timeout = 0;
 819         pSMB->hdr.Mid = GetNextMid(ses->server);
 820
 821         return SendReceive(xid, ses, in_buf, out_buf,
 822                         &bytes_returned, 0);
 823 }
 824
 825 int
 826 SendReceiveBlockingLock(const unsigned int xid, struct cifsTconInfo *tcon,
 827             struct smb_hdr *in_buf, struct smb_hdr *out_buf,
 828             int *pbytes_returned)
 829 {
 830         int rc = 0;
 831         int rstart = 0;
 832         unsigned int receive_len;
 833         struct mid_q_entry *midQ;
 834         struct cifsSesInfo *ses;
 835
 836         if (tcon == NULL || tcon->ses == NULL) {
 837                 cERROR(1,("Null smb session"));
 838                 return -EIO;
 839         }
 840         ses = tcon->ses;
 841
 842         if(ses->server == NULL) {
 843                 cERROR(1,("Null tcp session"));
 844                 return -EIO;
 845         }
 846
 847         if(ses->server->tcpStatus == CifsExiting)
 848                 return -ENOENT;
 849
 850         /* Ensure that we do not send more than 50 overlapping requests
 851            to the same server. We may make this configurable later or
 852            use ses->maxReq */
 853
 854         rc = wait_for_free_request(ses, 3);
 855         if (rc)
 856                 return rc;
 857
 858         /* make sure that we sign in the same order that we send on this socket
 859            and avoid races inside tcp sendmsg code that could cause corruption
 860            of smb data */
 861
 862         down(&ses->server->tcpSem);
 863
 864         rc = allocate_mid(ses, in_buf, &midQ);
 865         if (rc) {
 866                 up(&ses->server->tcpSem);
 867                 return rc;
 868         }
 869
 870         if (in_buf->smb_buf_length > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) {
 871                 up(&ses->server->tcpSem);
 872                 cERROR(1, ("Illegal length, greater than maximum frame, %d",
 873                         in_buf->smb_buf_length));
 874                 DeleteMidQEntry(midQ);
 875                 return -EIO;
 876         }
 877
 878         rc = cifs_sign_smb(in_buf, ses->server, &midQ->sequence_number);
 879
 880         midQ->midState = MID_REQUEST_SUBMITTED;
 881 #ifdef CONFIG_CIFS_STATS2
 882         atomic_inc(&ses->server->inSend);
 883 #endif
 884         rc = smb_send(ses->server->ssocket, in_buf, in_buf->smb_buf_length,
 885                       (struct sockaddr *) &(ses->server->addr.sockAddr));
 886 #ifdef CONFIG_CIFS_STATS2
 887         atomic_dec(&ses->server->inSend);
 888         midQ->when_sent = jiffies;
 889 #endif
 890         up(&ses->server->tcpSem);
 891
 892         if(rc < 0) {
 893                 DeleteMidQEntry(midQ);
 894                 return rc;
 895         }
 896
 897         /* Wait for a reply - allow signals to interrupt. */
 898         rc = wait_event_interruptible(ses->server->response_q,
 899                 (!(midQ->midState == MID_REQUEST_SUBMITTED)) ||
 900                 ((ses->server->tcpStatus != CifsGood) &&
 901                  (ses->server->tcpStatus != CifsNew)));
 902
 903         /* Were we interrupted by a signal ? */
 904         if ((rc == -ERESTARTSYS) &&
 905                 (midQ->midState == MID_REQUEST_SUBMITTED) &&
 906                 ((ses->server->tcpStatus == CifsGood) ||
 907                  (ses->server->tcpStatus == CifsNew))) {
 908
 909                 if (in_buf->Command == SMB_COM_TRANSACTION2) {
 910                         /* POSIX lock. We send a NT_CANCEL SMB to cause the
 911                            blocking lock to return. */
 912
 913                         rc = send_nt_cancel(tcon, in_buf, midQ);
 914                         if (rc) {
 915                                 DeleteMidQEntry(midQ);
 916                                 return rc;
 917                         }
 918                 } else {
 919                         /* Windows lock. We send a LOCKINGX_CANCEL_LOCK
 920                            to cause the blocking lock to return. */
 921
 922                         rc = send_lock_cancel(xid, tcon, in_buf, out_buf);
 923
 924                         /* If we get -ENOLCK back the lock may have
 925                            already been removed. Don't exit in this case. */
 926                         if (rc && rc != -ENOLCK) {
 927                                 DeleteMidQEntry(midQ);
 928                                 return rc;
 929                         }
 930                 }
 931
 932                 /* Wait 5 seconds for the response. */
 933                 if (wait_for_response(ses, midQ, 5 * HZ, 5 * HZ)==0) {
 934                         /* We got the response - restart system call. */
 935                         rstart = 1;
 936                 }
 937         }
 938
 939         spin_lock(&GlobalMid_Lock);
 940         if (midQ->resp_buf) {
 941                 spin_unlock(&GlobalMid_Lock);
 942                 receive_len = midQ->resp_buf->smb_buf_length;
 943         } else {
 944                 cERROR(1,("No response for cmd %d mid %d",
 945                           midQ->command, midQ->mid));
 946                 if(midQ->midState == MID_REQUEST_SUBMITTED) {
 947                         if(ses->server->tcpStatus == CifsExiting)
 948                                 rc = -EHOSTDOWN;
 949                         else {
 950                                 ses->server->tcpStatus = CifsNeedReconnect;
 951                                 midQ->midState = MID_RETRY_NEEDED;
 952                         }
 953                 }
 954
 955                 if (rc != -EHOSTDOWN) {
 956                         if(midQ->midState == MID_RETRY_NEEDED) {
 957                                 rc = -EAGAIN;
 958                                 cFYI(1,("marking request for retry"));
 959                         } else {
 960                                 rc = -EIO;
 961                         }
 962                 }
 963                 spin_unlock(&GlobalMid_Lock);
 964                 DeleteMidQEntry(midQ);
 965                 return rc;
 966         }
 967
 968         if (receive_len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE) {
 969                 cERROR(1, ("Frame too large received.  Length: %d  Xid: %d",
 970                         receive_len, xid));
 971                 rc = -EIO;
 972         } else {                /* rcvd frame is ok */
 973
 974                 if (midQ->resp_buf && out_buf
 975                     && (midQ->midState == MID_RESPONSE_RECEIVED)) {
 976                         out_buf->smb_buf_length = receive_len;
 977                         memcpy((char *)out_buf + 4,
 978                                (char *)midQ->resp_buf + 4,
 979                                receive_len);
 980
 981                         dump_smb(out_buf, 92);
 982                         /* convert the length into a more usable form */
 983                         if((receive_len > 24) &&
 984                            (ses->server->secMode & (SECMODE_SIGN_REQUIRED |
 985                                         SECMODE_SIGN_ENABLED))) {
 986                                 rc = cifs_verify_signature(out_buf,
 987                                                 ses->server->mac_signing_key,
 988                                                 midQ->sequence_number+1);
 989                                 if(rc) {
 990                                         cERROR(1,("Unexpected SMB signature"));
 991                                         /* BB FIXME add code to kill session */
 992                                 }
 993                         }
 994
 995                         *pbytes_returned = out_buf->smb_buf_length;
 996
 997                         /* BB special case reconnect tid and uid here? */
 998                         rc = map_smb_to_linux_error(out_buf);
 999
1000                         /* convert ByteCount if necessary */
1001                         if (receive_len >=
1002                             sizeof (struct smb_hdr) -
1003                             4 /* do not count RFC1001 header */  +
1004                             (2 * out_buf->WordCount) + 2 /* bcc */ )
1005                                 BCC(out_buf) = le16_to_cpu(BCC_LE(out_buf));
1006                 } else {
1007                         rc = -EIO;
1008                         cERROR(1,("Bad MID state?"));
1009                 }
1010         }
1011         DeleteMidQEntry(midQ);
1012         if (rstart && rc == -EACCES)
1013                 return -ERESTARTSYS;
1014         return rc;
1015 }