source3/smbd/aio.c

   1 /*
   2    Unix SMB/Netbios implementation.
   3    Version 3.0
   4    async_io read handling using POSIX async io.
   5    Copyright (C) Jeremy Allison 2005.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19 */
  20
  21 #include "includes.h"
  22 #include "smbd/globals.h"
  23
  24 #if defined(WITH_AIO)
  25
  26 /* The signal we'll use to signify aio done. */
  27 #ifndef RT_SIGNAL_AIO
  28 #define RT_SIGNAL_AIO   (SIGRTMIN+3)
  29 #endif
  30
  31 #ifndef HAVE_STRUCT_SIGEVENT_SIGEV_VALUE_SIVAL_PTR
  32 #ifdef HAVE_STRUCT_SIGEVENT_SIGEV_VALUE_SIGVAL_PTR
  33 #define sival_int       sigval_int
  34 #define sival_ptr       sigval_ptr
  35 #endif
  36 #endif
  37
  38 /****************************************************************************
  39  The buffer we keep around whilst an aio request is in process.
  40 *****************************************************************************/
  41
  42 struct aio_extra {
  43         struct aio_extra *next, *prev;
  44         SMB_STRUCT_AIOCB acb;
  45         files_struct *fsp;
  46         struct smb_request *req;
  47         char *outbuf;
  48         int (*handle_completion)(struct aio_extra *ex);
  49 };
  50
  51 static int handle_aio_read_complete(struct aio_extra *aio_ex);
  52 static int handle_aio_write_complete(struct aio_extra *aio_ex);
  53
  54 static int aio_extra_destructor(struct aio_extra *aio_ex)
  55 {
  56         DLIST_REMOVE(aio_list_head, aio_ex);
  57         return 0;
  58 }
  59
  60 /****************************************************************************
  61  Create the extended aio struct we must keep around for the lifetime
  62  of the aio call.
  63 *****************************************************************************/
  64
  65 static struct aio_extra *create_aio_extra(files_struct *fsp, size_t buflen)
  66 {
  67         struct aio_extra *aio_ex = TALLOC_ZERO_P(NULL, struct aio_extra);
  68
  69         if (!aio_ex) {
  70                 return NULL;
  71         }
  72
  73         /* The output buffer stored in the aio_ex is the start of
  74            the smb return buffer. The buffer used in the acb
  75            is the start of the reply data portion of that buffer. */
  76
  77         aio_ex->outbuf = TALLOC_ARRAY(aio_ex, char, buflen);
  78         if (!aio_ex->outbuf) {
  79                 TALLOC_FREE(aio_ex);
  80                 return NULL;
  81         }
  82         DLIST_ADD(aio_list_head, aio_ex);
  83         talloc_set_destructor(aio_ex, aio_extra_destructor);
  84         aio_ex->fsp = fsp;
  85         return aio_ex;
  86 }
  87
  88 /****************************************************************************
  89  Given the mid find the extended aio struct containing it.
  90 *****************************************************************************/
  91
  92 static struct aio_extra *find_aio_ex(uint16 mid)
  93 {
  94         struct aio_extra *p;
  95
  96         for( p = aio_list_head; p; p = p->next) {
  97                 if (mid == p->req->mid) {
  98                         return p;
  99                 }
 100         }
 101         return NULL;
 102 }
 103
 104 /****************************************************************************
 105  We can have these many aio buffers in flight.
 106 *****************************************************************************/
 107
 108 /****************************************************************************
 109  Set up an aio request from a SMBreadX call.
 110 *****************************************************************************/
 111
 112 bool schedule_aio_read_and_X(connection_struct *conn,
 113                              struct smb_request *req,
 114                              files_struct *fsp, SMB_OFF_T startpos,
 115                              size_t smb_maxcnt)
 116 {
 117         struct aio_extra *aio_ex;
 118         SMB_STRUCT_AIOCB *a;
 119         size_t bufsize;
 120         size_t min_aio_read_size = lp_aio_read_size(SNUM(conn));
 121         int ret;
 122
 123         if (fsp->base_fsp != NULL) {
 124                 /* No AIO on streams yet */
 125                 DEBUG(10, ("AIO on streams not yet supported\n"));
 126                 return false;
 127         }
 128
 129         if ((!min_aio_read_size || (smb_maxcnt < min_aio_read_size))
 130             && !SMB_VFS_AIO_FORCE(fsp)) {
 131                 /* Too small a read for aio request. */
 132                 DEBUG(10,("schedule_aio_read_and_X: read size (%u) too small "
 133                           "for minimum aio_read of %u\n",
 134                           (unsigned int)smb_maxcnt,
 135                           (unsigned int)min_aio_read_size ));
 136                 return False;
 137         }
 138
 139         /* Only do this on non-chained and non-chaining reads not using the
 140          * write cache. */
 141         if (req_is_in_chain(req) || (lp_write_cache_size(SNUM(conn)) != 0)) {
 142                 return False;
 143         }
 144
 145         if (outstanding_aio_calls >= aio_pending_size) {
 146                 DEBUG(10,("schedule_aio_read_and_X: Already have %d aio "
 147                           "activities outstanding.\n",
 148                           outstanding_aio_calls ));
 149                 return False;
 150         }
 151
 152         /* The following is safe from integer wrap as we've already checked
 153            smb_maxcnt is 128k or less. Wct is 12 for read replies */
 154
 155         bufsize = smb_size + 12 * 2 + smb_maxcnt;
 156
 157         if ((aio_ex = create_aio_extra(fsp, bufsize)) == NULL) {
 158                 DEBUG(10,("schedule_aio_read_and_X: malloc fail.\n"));
 159                 return False;
 160         }
 161         aio_ex->handle_completion = handle_aio_read_complete;
 162
 163         construct_reply_common_req(req, aio_ex->outbuf);
 164         srv_set_message(aio_ex->outbuf, 12, 0, True);
 165         SCVAL(aio_ex->outbuf,smb_vwv0,0xFF); /* Never a chained reply. */
 166
 167         a = &aio_ex->acb;
 168
 169         /* Now set up the aio record for the read call. */
 170
 171         a->aio_fildes = fsp->fh->fd;
 172         a->aio_buf = smb_buf(aio_ex->outbuf);
 173         a->aio_nbytes = smb_maxcnt;
 174         a->aio_offset = startpos;
 175         a->aio_sigevent.sigev_notify = SIGEV_SIGNAL;
 176         a->aio_sigevent.sigev_signo  = RT_SIGNAL_AIO;
 177         a->aio_sigevent.sigev_value.sival_int = req->mid;
 178
 179         ret = SMB_VFS_AIO_READ(fsp, a);
 180         if (ret == -1) {
 181                 DEBUG(0,("schedule_aio_read_and_X: aio_read failed. "
 182                          "Error %s\n", strerror(errno) ));
 183                 TALLOC_FREE(aio_ex);
 184                 return False;
 185         }
 186
 187         aio_ex->req = talloc_move(aio_ex, &req);
 188
 189         DEBUG(10,("schedule_aio_read_and_X: scheduled aio_read for file %s, "
 190                   "offset %.0f, len = %u (mid = %u)\n",
 191                   fsp_str_dbg(fsp), (double)startpos, (unsigned int)smb_maxcnt,
 192                   (unsigned int)aio_ex->req->mid ));
 193
 194         outstanding_aio_calls++;
 195         return True;
 196 }
 197
 198 /****************************************************************************
 199  Set up an aio request from a SMBwriteX call.
 200 *****************************************************************************/
 201
 202 bool schedule_aio_write_and_X(connection_struct *conn,
 203                               struct smb_request *req,
 204                               files_struct *fsp, char *data,
 205                               SMB_OFF_T startpos,
 206                               size_t numtowrite)
 207 {
 208         struct aio_extra *aio_ex;
 209         SMB_STRUCT_AIOCB *a;
 210         size_t bufsize;
 211         bool write_through = BITSETW(req->vwv+7,0);
 212         size_t min_aio_write_size = lp_aio_write_size(SNUM(conn));
 213         int ret;
 214
 215         if (fsp->base_fsp != NULL) {
 216                 /* No AIO on streams yet */
 217                 DEBUG(10, ("AIO on streams not yet supported\n"));
 218                 return false;
 219         }
 220
 221         if ((!min_aio_write_size || (numtowrite < min_aio_write_size))
 222             && !SMB_VFS_AIO_FORCE(fsp)) {
 223                 /* Too small a write for aio request. */
 224                 DEBUG(10,("schedule_aio_write_and_X: write size (%u) too "
 225                           "small for minimum aio_write of %u\n",
 226                           (unsigned int)numtowrite,
 227                           (unsigned int)min_aio_write_size ));
 228                 return False;
 229         }
 230
 231         /* Only do this on non-chained and non-chaining reads not using the
 232          * write cache. */
 233         if (req_is_in_chain(req) || (lp_write_cache_size(SNUM(conn)) != 0)) {
 234                 return False;
 235         }
 236
 237         if (outstanding_aio_calls >= aio_pending_size) {
 238                 DEBUG(3,("schedule_aio_write_and_X: Already have %d aio "
 239                          "activities outstanding.\n",
 240                           outstanding_aio_calls ));
 241                 DEBUG(10,("schedule_aio_write_and_X: failed to schedule "
 242                           "aio_write for file %s, offset %.0f, len = %u "
 243                           "(mid = %u)\n",
 244                           fsp_str_dbg(fsp), (double)startpos,
 245                           (unsigned int)numtowrite,
 246                           (unsigned int)req->mid ));
 247                 return False;
 248         }
 249
 250         bufsize = smb_size + 6*2;
 251
 252         if (!(aio_ex = create_aio_extra(fsp, bufsize))) {
 253                 DEBUG(0,("schedule_aio_write_and_X: malloc fail.\n"));
 254                 return False;
 255         }
 256         aio_ex->handle_completion = handle_aio_write_complete;
 257
 258         construct_reply_common_req(req, aio_ex->outbuf);
 259         srv_set_message(aio_ex->outbuf, 6, 0, True);
 260         SCVAL(aio_ex->outbuf,smb_vwv0,0xFF); /* Never a chained reply. */
 261
 262         a = &aio_ex->acb;
 263
 264         /* Now set up the aio record for the write call. */
 265
 266         a->aio_fildes = fsp->fh->fd;
 267         a->aio_buf = data;
 268         a->aio_nbytes = numtowrite;
 269         a->aio_offset = startpos;
 270         a->aio_sigevent.sigev_notify = SIGEV_SIGNAL;
 271         a->aio_sigevent.sigev_signo  = RT_SIGNAL_AIO;
 272         a->aio_sigevent.sigev_value.sival_int = req->mid;
 273
 274         ret = SMB_VFS_AIO_WRITE(fsp, a);
 275         if (ret == -1) {
 276                 DEBUG(3,("schedule_aio_wrote_and_X: aio_write failed. "
 277                          "Error %s\n", strerror(errno) ));
 278                 TALLOC_FREE(aio_ex);
 279                 return False;
 280         }
 281
 282         aio_ex->req = talloc_move(aio_ex, &req);
 283
 284         /* This should actually be improved to span the write. */
 285         contend_level2_oplocks_begin(fsp, LEVEL2_CONTEND_WRITE);
 286         contend_level2_oplocks_end(fsp, LEVEL2_CONTEND_WRITE);
 287
 288         if (!write_through && !lp_syncalways(SNUM(fsp->conn))
 289             && fsp->aio_write_behind) {
 290                 /* Lie to the client and immediately claim we finished the
 291                  * write. */
 292                 SSVAL(aio_ex->outbuf,smb_vwv2,numtowrite);
 293                 SSVAL(aio_ex->outbuf,smb_vwv4,(numtowrite>>16)&1);
 294                 show_msg(aio_ex->outbuf);
 295                 if (!srv_send_smb(smbd_server_fd(),aio_ex->outbuf,
 296                                 true, aio_ex->req->seqnum+1,
 297                                 IS_CONN_ENCRYPTED(fsp->conn),
 298                                 &req->pcd)) {
 299                         exit_server_cleanly("handle_aio_write: srv_send_smb "
 300                                             "failed.");
 301                 }
 302                 DEBUG(10,("schedule_aio_write_and_X: scheduled aio_write "
 303                           "behind for file %s\n", fsp_str_dbg(fsp)));
 304         }
 305         outstanding_aio_calls++;
 306
 307         DEBUG(10,("schedule_aio_write_and_X: scheduled aio_write for file "
 308                   "%s, offset %.0f, len = %u (mid = %u) "
 309                   "outstanding_aio_calls = %d\n",
 310                   fsp_str_dbg(fsp), (double)startpos, (unsigned int)numtowrite,
 311                   (unsigned int)aio_ex->req->mid, outstanding_aio_calls ));
 312
 313         return True;
 314 }
 315
 316
 317 /****************************************************************************
 318  Complete the read and return the data or error back to the client.
 319  Returns errno or zero if all ok.
 320 *****************************************************************************/
 321
 322 static int handle_aio_read_complete(struct aio_extra *aio_ex)
 323 {
 324         int ret = 0;
 325         int outsize;
 326         char *outbuf = aio_ex->outbuf;
 327         char *data = smb_buf(outbuf);
 328         ssize_t nread = SMB_VFS_AIO_RETURN(aio_ex->fsp,&aio_ex->acb);
 329
 330         if (nread < 0) {
 331                 /* We're relying here on the fact that if the fd is
 332                    closed then the aio will complete and aio_return
 333                    will return an error. Hopefully this is
 334                    true.... JRA. */
 335
 336                 /* If errno is ECANCELED then don't return anything to the
 337                  * client. */
 338                 if (errno == ECANCELED) {
 339                         return 0;
 340                 }
 341
 342                 DEBUG( 3,( "handle_aio_read_complete: file %s nread == -1. "
 343                            "Error = %s\n",
 344                            fsp_str_dbg(aio_ex->fsp), strerror(errno)));
 345
 346                 ret = errno;
 347                 ERROR_NT(map_nt_error_from_unix(ret));
 348                 outsize = srv_set_message(outbuf,0,0,true);
 349         } else {
 350                 outsize = srv_set_message(outbuf,12,nread,False);
 351                 SSVAL(outbuf,smb_vwv2,0xFFFF); /* Remaining - must be * -1. */
 352                 SSVAL(outbuf,smb_vwv5,nread);
 353                 SSVAL(outbuf,smb_vwv6,smb_offset(data,outbuf));
 354                 SSVAL(outbuf,smb_vwv7,((nread >> 16) & 1));
 355                 SSVAL(smb_buf(outbuf),-2,nread);
 356
 357                 aio_ex->fsp->fh->pos = aio_ex->acb.aio_offset + nread;
 358                 aio_ex->fsp->fh->position_information = aio_ex->fsp->fh->pos;
 359
 360                 DEBUG( 3, ( "handle_aio_read_complete file %s max=%d "
 361                             "nread=%d\n",
 362                             fsp_str_dbg(aio_ex->fsp),
 363                             (int)aio_ex->acb.aio_nbytes, (int)nread ) );
 364
 365         }
 366         smb_setlen(outbuf,outsize - 4);
 367         show_msg(outbuf);
 368         if (!srv_send_smb(smbd_server_fd(),outbuf,
 369                         true, aio_ex->req->seqnum+1,
 370                         IS_CONN_ENCRYPTED(aio_ex->fsp->conn), NULL)) {
 371                 exit_server_cleanly("handle_aio_read_complete: srv_send_smb "
 372                                     "failed.");
 373         }
 374
 375         DEBUG(10,("handle_aio_read_complete: scheduled aio_read completed "
 376                   "for file %s, offset %.0f, len = %u\n",
 377                   fsp_str_dbg(aio_ex->fsp), (double)aio_ex->acb.aio_offset,
 378                   (unsigned int)nread ));
 379
 380         return ret;
 381 }
 382
 383 /****************************************************************************
 384  Complete the write and return the data or error back to the client.
 385  Returns errno or zero if all ok.
 386 *****************************************************************************/
 387
 388 static int handle_aio_write_complete(struct aio_extra *aio_ex)
 389 {
 390         int ret = 0;
 391         files_struct *fsp = aio_ex->fsp;
 392         char *outbuf = aio_ex->outbuf;
 393         ssize_t numtowrite = aio_ex->acb.aio_nbytes;
 394         ssize_t nwritten = SMB_VFS_AIO_RETURN(fsp,&aio_ex->acb);
 395
 396         if (fsp->aio_write_behind) {
 397                 if (nwritten != numtowrite) {
 398                         if (nwritten == -1) {
 399                                 DEBUG(5,("handle_aio_write_complete: "
 400                                          "aio_write_behind failed ! File %s "
 401                                          "is corrupt ! Error %s\n",
 402                                          fsp_str_dbg(fsp), strerror(errno)));
 403                                 ret = errno;
 404                         } else {
 405                                 DEBUG(0,("handle_aio_write_complete: "
 406                                          "aio_write_behind failed ! File %s "
 407                                          "is corrupt ! Wanted %u bytes but "
 408                                          "only wrote %d\n", fsp_str_dbg(fsp),
 409                                          (unsigned int)numtowrite,
 410                                          (int)nwritten ));
 411                                 ret = EIO;
 412                         }
 413                 } else {
 414                         DEBUG(10,("handle_aio_write_complete: "
 415                                   "aio_write_behind completed for file %s\n",
 416                                   fsp_str_dbg(fsp)));
 417                 }
 418                 return 0;
 419         }
 420
 421         /* We don't need outsize or set_message here as we've already set the
 422            fixed size length when we set up the aio call. */
 423
 424         if(nwritten == -1) {
 425                 DEBUG( 3,( "handle_aio_write: file %s wanted %u bytes. "
 426                            "nwritten == %d. Error = %s\n",
 427                            fsp_str_dbg(fsp), (unsigned int)numtowrite,
 428                            (int)nwritten, strerror(errno) ));
 429
 430                 /* If errno is ECANCELED then don't return anything to the
 431                  * client. */
 432                 if (errno == ECANCELED) {
 433                         return 0;
 434                 }
 435
 436                 ret = errno;
 437                 ERROR_BOTH(map_nt_error_from_unix(ret), ERRHRD, ERRdiskfull);
 438                 srv_set_message(outbuf,0,0,true);
 439         } else {
 440                 bool write_through = BITSETW(aio_ex->req->vwv+7,0);
 441                 NTSTATUS status;
 442
 443                 SSVAL(outbuf,smb_vwv2,nwritten);
 444                 SSVAL(outbuf,smb_vwv4,(nwritten>>16)&1);
 445                 if (nwritten < (ssize_t)numtowrite) {
 446                         SCVAL(outbuf,smb_rcls,ERRHRD);
 447                         SSVAL(outbuf,smb_err,ERRdiskfull);
 448                 }
 449
 450                 DEBUG(3,("handle_aio_write: fnum=%d num=%d wrote=%d\n",
 451                          fsp->fnum, (int)numtowrite, (int)nwritten));
 452                 status = sync_file(fsp->conn,fsp, write_through);
 453                 if (!NT_STATUS_IS_OK(status)) {
 454                         ret = errno;
 455                         ERROR_BOTH(map_nt_error_from_unix(ret),
 456                                    ERRHRD, ERRdiskfull);
 457                         srv_set_message(outbuf,0,0,true);
 458                         DEBUG(5,("handle_aio_write: sync_file for %s returned %s\n",
 459                                  fsp_str_dbg(fsp), nt_errstr(status)));
 460                 }
 461
 462                 aio_ex->fsp->fh->pos = aio_ex->acb.aio_offset + nwritten;
 463         }
 464
 465         show_msg(outbuf);
 466         if (!srv_send_smb(smbd_server_fd(),outbuf,
 467                           true, aio_ex->req->seqnum+1,
 468                           IS_CONN_ENCRYPTED(fsp->conn),
 469                           NULL)) {
 470                 exit_server_cleanly("handle_aio_write: srv_send_smb failed.");
 471         }
 472
 473         DEBUG(10,("handle_aio_write_complete: scheduled aio_write completed "
 474                   "for file %s, offset %.0f, requested %u, written = %u\n",
 475                   fsp_str_dbg(fsp), (double)aio_ex->acb.aio_offset,
 476                   (unsigned int)numtowrite, (unsigned int)nwritten ));
 477
 478         return ret;
 479 }
 480
 481 /****************************************************************************
 482  Handle any aio completion. Returns True if finished (and sets *perr if err
 483  was non-zero), False if not.
 484 *****************************************************************************/
 485
 486 static bool handle_aio_completed(struct aio_extra *aio_ex, int *perr)
 487 {
 488         int err;
 489
 490         if(!aio_ex) {
 491                 DEBUG(3, ("handle_aio_completed: Non-existing aio_ex passed\n"));
 492                 return false;
 493         }
 494
 495         /* Ensure the operation has really completed. */
 496         if (SMB_VFS_AIO_ERROR(aio_ex->fsp, &aio_ex->acb) == EINPROGRESS) {
 497                 DEBUG(10,( "handle_aio_completed: operation mid %u still in "
 498                            "process for file %s\n",
 499                            aio_ex->req->mid, fsp_str_dbg(aio_ex->fsp)));
 500                 return False;
 501         }
 502
 503         err = aio_ex->handle_completion(aio_ex);
 504         if (err) {
 505                 *perr = err; /* Only save non-zero errors. */
 506         }
 507
 508         return True;
 509 }
 510
 511 /****************************************************************************
 512  Handle any aio completion inline.
 513  Returns non-zero errno if fail or zero if all ok.
 514 *****************************************************************************/
 515
 516 void smbd_aio_complete_mid(unsigned int mid)
 517 {
 518         files_struct *fsp = NULL;
 519         struct aio_extra *aio_ex = find_aio_ex(mid);
 520         int ret = 0;
 521
 522         DEBUG(10,("smbd_aio_complete_mid: mid[%u]\n", mid));
 523
 524         if (!aio_ex) {
 525                 DEBUG(3,("smbd_aio_complete_mid: Can't find record to "
 526                          "match mid %u.\n", mid));
 527                 return;
 528         }
 529
 530         fsp = aio_ex->fsp;
 531         if (fsp == NULL) {
 532                 /* file was closed whilst I/O was outstanding. Just
 533                  * ignore. */
 534                 DEBUG( 3,( "smbd_aio_complete_mid: file closed whilst "
 535                            "aio outstanding (mid[%u]).\n", mid));
 536                 return;
 537         }
 538
 539         if (!handle_aio_completed(aio_ex, &ret)) {
 540                 return;
 541         }
 542
 543         TALLOC_FREE(aio_ex);
 544 }
 545
 546 static void smbd_aio_signal_handler(struct tevent_context *ev_ctx,
 547                                     struct tevent_signal *se,
 548                                     int signum, int count,
 549                                     void *_info, void *private_data)
 550 {
 551         siginfo_t *info = (siginfo_t *)_info;
 552         unsigned int mid = (unsigned int)info->si_value.sival_int;
 553
 554         smbd_aio_complete_mid(mid);
 555 }
 556
 557 /****************************************************************************
 558  We're doing write behind and the client closed the file. Wait up to 30
 559  seconds (my arbitrary choice) for the aio to complete. Return 0 if all writes
 560  completed, errno to return if not.
 561 *****************************************************************************/
 562
 563 #define SMB_TIME_FOR_AIO_COMPLETE_WAIT 29
 564
 565 int wait_for_aio_completion(files_struct *fsp)
 566 {
 567         struct aio_extra *aio_ex;
 568         const SMB_STRUCT_AIOCB **aiocb_list;
 569         int aio_completion_count = 0;
 570         time_t start_time = time(NULL);
 571         int seconds_left;
 572
 573         for (seconds_left = SMB_TIME_FOR_AIO_COMPLETE_WAIT;
 574              seconds_left >= 0;) {
 575                 int err = 0;
 576                 int i;
 577                 struct timespec ts;
 578
 579                 aio_completion_count = 0;
 580                 for( aio_ex = aio_list_head; aio_ex; aio_ex = aio_ex->next) {
 581                         if (aio_ex->fsp == fsp) {
 582                                 aio_completion_count++;
 583                         }
 584                 }
 585
 586                 if (!aio_completion_count) {
 587                         return 0;
 588                 }
 589
 590                 DEBUG(3,("wait_for_aio_completion: waiting for %d aio events "
 591                          "to complete.\n", aio_completion_count ));
 592
 593                 aiocb_list = SMB_MALLOC_ARRAY(const SMB_STRUCT_AIOCB *,
 594                                               aio_completion_count);
 595                 if (!aiocb_list) {
 596                         return ENOMEM;
 597                 }
 598
 599                 for( i = 0, aio_ex = aio_list_head;
 600                      aio_ex;
 601                      aio_ex = aio_ex->next) {
 602                         if (aio_ex->fsp == fsp) {
 603                                 aiocb_list[i++] = &aio_ex->acb;
 604                         }
 605                 }
 606
 607                 /* Now wait up to seconds_left for completion. */
 608                 ts.tv_sec = seconds_left;
 609                 ts.tv_nsec = 0;
 610
 611                 DEBUG(10,("wait_for_aio_completion: %d events, doing a wait "
 612                           "of %d seconds.\n",
 613                           aio_completion_count, seconds_left ));
 614
 615                 err = SMB_VFS_AIO_SUSPEND(fsp, aiocb_list,
 616                                           aio_completion_count, &ts);
 617
 618                 DEBUG(10,("wait_for_aio_completion: returned err = %d, "
 619                           "errno = %s\n", err, strerror(errno) ));
 620
 621                 if (err == -1 && errno == EAGAIN) {
 622                         DEBUG(0,("wait_for_aio_completion: aio_suspend timed "
 623                                  "out waiting for %d events after a wait of "
 624                                  "%d seconds\n", aio_completion_count,
 625                                  seconds_left));
 626                         /* Timeout. */
 627                         cancel_aio_by_fsp(fsp);
 628                         SAFE_FREE(aiocb_list);
 629                         return EIO;
 630                 }
 631
 632                 /* One or more events might have completed - process them if
 633                  * so. */
 634                 for( i = 0; i < aio_completion_count; i++) {
 635                         uint16 mid = aiocb_list[i]->aio_sigevent.sigev_value.sival_int;
 636
 637                         aio_ex = find_aio_ex(mid);
 638
 639                         if (!aio_ex) {
 640                                 DEBUG(0, ("wait_for_aio_completion: mid %u "
 641                                           "doesn't match an aio record\n",
 642                                           (unsigned int)mid ));
 643                                 continue;
 644                         }
 645
 646                         if (!handle_aio_completed(aio_ex, &err)) {
 647                                 continue;
 648                         }
 649                         TALLOC_FREE(aio_ex);
 650                 }
 651
 652                 SAFE_FREE(aiocb_list);
 653                 seconds_left = SMB_TIME_FOR_AIO_COMPLETE_WAIT
 654                         - (time(NULL) - start_time);
 655         }
 656
 657         /* We timed out - we don't know why. Return ret if already an error,
 658          * else EIO. */
 659         DEBUG(10,("wait_for_aio_completion: aio_suspend timed out waiting "
 660                   "for %d events\n",
 661                   aio_completion_count));
 662
 663         return EIO;
 664 }
 665
 666 /****************************************************************************
 667  Cancel any outstanding aio requests. The client doesn't care about the reply.
 668 *****************************************************************************/
 669
 670 void cancel_aio_by_fsp(files_struct *fsp)
 671 {
 672         struct aio_extra *aio_ex;
 673
 674         for( aio_ex = aio_list_head; aio_ex; aio_ex = aio_ex->next) {
 675                 if (aio_ex->fsp == fsp) {
 676                         /* Don't delete the aio_extra record as we may have
 677                            completed and don't yet know it. Just do the
 678                            aio_cancel call and return. */
 679                         SMB_VFS_AIO_CANCEL(fsp, &aio_ex->acb);
 680                         aio_ex->fsp = NULL; /* fsp will be closed when we
 681                                              * return. */
 682                 }
 683         }
 684 }
 685
 686 /****************************************************************************
 687  Initialize the signal handler for aio read/write.
 688 *****************************************************************************/
 689
 690 void initialize_async_io_handler(void)
 691 {
 692         aio_signal_event = tevent_add_signal(smbd_event_context(),
 693                                              smbd_event_context(),
 694                                              RT_SIGNAL_AIO, SA_SIGINFO,
 695                                              smbd_aio_signal_handler,
 696                                              NULL);
 697         if (!aio_signal_event) {
 698                 exit_server("Failed to setup RT_SIGNAL_AIO handler");
 699         }
 700
 701         /* tevent supports 100 signal with SA_SIGINFO */
 702         aio_pending_size = 100;
 703 }
 704
 705 #else
 706 void initialize_async_io_handler(void)
 707 {
 708 }
 709
 710 bool schedule_aio_read_and_X(connection_struct *conn,
 711                              struct smb_request *req,
 712                              files_struct *fsp, SMB_OFF_T startpos,
 713                              size_t smb_maxcnt)
 714 {
 715         return False;
 716 }
 717
 718 bool schedule_aio_write_and_X(connection_struct *conn,
 719                               struct smb_request *req,
 720                               files_struct *fsp, char *data,
 721                               SMB_OFF_T startpos,
 722                               size_t numtowrite)
 723 {
 724         return False;
 725 }
 726
 727 void cancel_aio_by_fsp(files_struct *fsp)
 728 {
 729 }
 730
 731 int wait_for_aio_completion(files_struct *fsp)
 732 {
 733         return ENOSYS;
 734 }
 735
 736 void smbd_aio_complete_mid(unsigned int mid);
 737
 738 #endif