source/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
  23 #if defined(WITH_AIO)
  24
  25 /* The signal we'll use to signify aio done. */
  26 #ifndef RT_SIGNAL_AIO
  27 #define RT_SIGNAL_AIO (SIGRTMIN+3)
  28 #endif
  29
  30 /****************************************************************************
  31  The buffer we keep around whilst an aio request is in process.
  32 *****************************************************************************/
  33
  34 struct aio_extra {
  35         struct aio_extra *next, *prev;
  36         SMB_STRUCT_AIOCB acb;
  37         files_struct *fsp;
  38         bool read_req;
  39         uint16 mid;
  40         char *inbuf;
  41         char *outbuf;
  42 };
  43
  44 static struct aio_extra *aio_list_head;
  45
  46 /****************************************************************************
  47  Create the extended aio struct we must keep around for the lifetime
  48  of the aio_read call.
  49 *****************************************************************************/
  50
  51 static struct aio_extra *create_aio_ex_read(files_struct *fsp, size_t buflen,
  52                                             uint16 mid)
  53 {
  54         struct aio_extra *aio_ex = SMB_MALLOC_P(struct aio_extra);
  55
  56         if (!aio_ex) {
  57                 return NULL;
  58         }
  59         ZERO_STRUCTP(aio_ex);
  60         /* The output buffer stored in the aio_ex is the start of
  61            the smb return buffer. The buffer used in the acb
  62            is the start of the reply data portion of that buffer. */
  63         aio_ex->outbuf = SMB_MALLOC_ARRAY(char, buflen);
  64         if (!aio_ex->outbuf) {
  65                 SAFE_FREE(aio_ex);
  66                 return NULL;
  67         }
  68         DLIST_ADD(aio_list_head, aio_ex);
  69         aio_ex->fsp = fsp;
  70         aio_ex->read_req = True;
  71         aio_ex->mid = mid;
  72         return aio_ex;
  73 }
  74
  75 /****************************************************************************
  76  Create the extended aio struct we must keep around for the lifetime
  77  of the aio_write call.
  78 *****************************************************************************/
  79
  80 static struct aio_extra *create_aio_ex_write(files_struct *fsp,
  81                                              size_t inbuflen,
  82                                              size_t outbuflen,
  83                                              uint16 mid)
  84 {
  85         struct aio_extra *aio_ex = SMB_MALLOC_P(struct aio_extra);
  86
  87         if (!aio_ex) {
  88                 return NULL;
  89         }
  90         ZERO_STRUCTP(aio_ex);
  91
  92         /* We need space for an output reply of outbuflen bytes. */
  93         aio_ex->outbuf = SMB_MALLOC_ARRAY(char, outbuflen);
  94         if (!aio_ex->outbuf) {
  95                 SAFE_FREE(aio_ex);
  96                 return NULL;
  97         }
  98
  99         if (!(aio_ex->inbuf = SMB_MALLOC_ARRAY(char, inbuflen))) {
 100                 SAFE_FREE(aio_ex->outbuf);
 101                 SAFE_FREE(aio_ex);
 102                 return NULL;
 103         }
 104
 105         DLIST_ADD(aio_list_head, aio_ex);
 106         aio_ex->fsp = fsp;
 107         aio_ex->read_req = False;
 108         aio_ex->mid = mid;
 109         return aio_ex;
 110 }
 111
 112 /****************************************************************************
 113  Delete the extended aio struct.
 114 *****************************************************************************/
 115
 116 static void delete_aio_ex(struct aio_extra *aio_ex)
 117 {
 118         DLIST_REMOVE(aio_list_head, aio_ex);
 119         SAFE_FREE(aio_ex->inbuf);
 120         SAFE_FREE(aio_ex->outbuf);
 121         SAFE_FREE(aio_ex);
 122 }
 123
 124 /****************************************************************************
 125  Given the aiocb struct find the extended aio struct containing it.
 126 *****************************************************************************/
 127
 128 static struct aio_extra *find_aio_ex(uint16 mid)
 129 {
 130         struct aio_extra *p;
 131
 132         for( p = aio_list_head; p; p = p->next) {
 133                 if (mid == p->mid) {
 134                         return p;
 135                 }
 136         }
 137         return NULL;
 138 }
 139
 140 /****************************************************************************
 141  We can have these many aio buffers in flight.
 142 *****************************************************************************/
 143
 144 #define AIO_PENDING_SIZE 10
 145 static sig_atomic_t signals_received;
 146 static int outstanding_aio_calls;
 147 static uint16 aio_pending_array[AIO_PENDING_SIZE];
 148
 149 /****************************************************************************
 150  Signal handler when an aio request completes.
 151 *****************************************************************************/
 152
 153 static void signal_handler(int sig, siginfo_t *info, void *unused)
 154 {
 155         if (signals_received < AIO_PENDING_SIZE) {
 156                 aio_pending_array[signals_received] = info->si_value.sival_int;
 157                 signals_received++;
 158         } /* Else signal is lost. */
 159         sys_select_signal(RT_SIGNAL_AIO);
 160 }
 161
 162 /****************************************************************************
 163  Is there a signal waiting ?
 164 *****************************************************************************/
 165
 166 bool aio_finished(void)
 167 {
 168         return (signals_received != 0);
 169 }
 170
 171 /****************************************************************************
 172  Initialize the signal handler for aio read/write.
 173 *****************************************************************************/
 174
 175 void initialize_async_io_handler(void)
 176 {
 177         struct sigaction act;
 178
 179         ZERO_STRUCT(act);
 180         act.sa_sigaction = signal_handler;
 181         act.sa_flags = SA_SIGINFO;
 182         sigemptyset( &act.sa_mask );
 183         if (sigaction(RT_SIGNAL_AIO, &act, NULL) != 0) {
 184                 DEBUG(0,("Failed to setup RT_SIGNAL_AIO handler\n"));
 185         }
 186
 187         /* the signal can start off blocked due to a bug in bash */
 188         BlockSignals(False, RT_SIGNAL_AIO);
 189 }
 190
 191 /****************************************************************************
 192  Set up an aio request from a SMBreadX call.
 193 *****************************************************************************/
 194
 195 bool schedule_aio_read_and_X(connection_struct *conn,
 196                              struct smb_request *req,
 197                              files_struct *fsp, SMB_OFF_T startpos,
 198                              size_t smb_maxcnt)
 199 {
 200         struct aio_extra *aio_ex;
 201         SMB_STRUCT_AIOCB *a;
 202         size_t bufsize;
 203         size_t min_aio_read_size = lp_aio_read_size(SNUM(conn));
 204
 205         if ((!min_aio_read_size || (smb_maxcnt < min_aio_read_size))
 206             && !SMB_VFS_AIO_FORCE(fsp)) {
 207                 /* Too small a read for aio request. */
 208                 DEBUG(10,("schedule_aio_read_and_X: read size (%u) too small "
 209                           "for minimum aio_read of %u\n",
 210                           (unsigned int)smb_maxcnt,
 211                           (unsigned int)min_aio_read_size ));
 212                 return False;
 213         }
 214
 215         /* Only do this on non-chained and non-chaining reads not using the
 216          * write cache. */
 217         if (chain_size !=0 || (CVAL(req->inbuf,smb_vwv0) != 0xFF)
 218             || (lp_write_cache_size(SNUM(conn)) != 0) ) {
 219                 return False;
 220         }
 221
 222         if (outstanding_aio_calls >= AIO_PENDING_SIZE) {
 223                 DEBUG(10,("schedule_aio_read_and_X: Already have %d aio "
 224                           "activities outstanding.\n",
 225                           outstanding_aio_calls ));
 226                 return False;
 227         }
 228
 229         /* The following is safe from integer wrap as we've already checked
 230            smb_maxcnt is 128k or less. Wct is 12 for read replies */
 231
 232         bufsize = smb_size + 12 * 2 + smb_maxcnt;
 233
 234         if ((aio_ex = create_aio_ex_read(fsp, bufsize, req->mid)) == NULL) {
 235                 DEBUG(10,("schedule_aio_read_and_X: malloc fail.\n"));
 236                 return False;
 237         }
 238
 239         construct_reply_common((char *)req->inbuf, aio_ex->outbuf);
 240         srv_set_message(aio_ex->outbuf, 12, 0, True);
 241         SCVAL(aio_ex->outbuf,smb_vwv0,0xFF); /* Never a chained reply. */
 242
 243         a = &aio_ex->acb;
 244
 245         /* Now set up the aio record for the read call. */
 246
 247         a->aio_fildes = fsp->fh->fd;
 248         a->aio_buf = smb_buf(aio_ex->outbuf);
 249         a->aio_nbytes = smb_maxcnt;
 250         a->aio_offset = startpos;
 251         a->aio_sigevent.sigev_notify = SIGEV_SIGNAL;
 252         a->aio_sigevent.sigev_signo  = RT_SIGNAL_AIO;
 253         a->aio_sigevent.sigev_value.sival_int = aio_ex->mid;
 254
 255         if (SMB_VFS_AIO_READ(fsp,a) == -1) {
 256                 DEBUG(0,("schedule_aio_read_and_X: aio_read failed. "
 257                          "Error %s\n", strerror(errno) ));
 258                 delete_aio_ex(aio_ex);
 259                 return False;
 260         }
 261
 262         DEBUG(10,("schedule_aio_read_and_X: scheduled aio_read for file %s, "
 263                   "offset %.0f, len = %u (mid = %u)\n",
 264                   fsp->fsp_name, (double)startpos, (unsigned int)smb_maxcnt,
 265                   (unsigned int)aio_ex->mid ));
 266
 267         srv_defer_sign_response(aio_ex->mid);
 268         outstanding_aio_calls++;
 269         return True;
 270 }
 271
 272 /****************************************************************************
 273  Set up an aio request from a SMBwriteX call.
 274 *****************************************************************************/
 275
 276 bool schedule_aio_write_and_X(connection_struct *conn,
 277                               struct smb_request *req,
 278                               files_struct *fsp, char *data,
 279                               SMB_OFF_T startpos,
 280                               size_t numtowrite)
 281 {
 282         struct aio_extra *aio_ex;
 283         SMB_STRUCT_AIOCB *a;
 284         size_t inbufsize, outbufsize;
 285         bool write_through = BITSETW(req->inbuf+smb_vwv7,0);
 286         size_t min_aio_write_size = lp_aio_write_size(SNUM(conn));
 287
 288         if ((!min_aio_write_size || (numtowrite < min_aio_write_size))
 289             && !SMB_VFS_AIO_FORCE(fsp)) {
 290                 /* Too small a write for aio request. */
 291                 DEBUG(10,("schedule_aio_write_and_X: write size (%u) too "
 292                           "small for minimum aio_write of %u\n",
 293                           (unsigned int)numtowrite,
 294                           (unsigned int)min_aio_write_size ));
 295                 return False;
 296         }
 297
 298         /* Only do this on non-chained and non-chaining reads not using the
 299          * write cache. */
 300         if (chain_size !=0 || (CVAL(req->inbuf,smb_vwv0) != 0xFF)
 301             || (lp_write_cache_size(SNUM(conn)) != 0) ) {
 302                 return False;
 303         }
 304
 305         if (outstanding_aio_calls >= AIO_PENDING_SIZE) {
 306                 DEBUG(3,("schedule_aio_write_and_X: Already have %d aio "
 307                          "activities outstanding.\n",
 308                           outstanding_aio_calls ));
 309                 DEBUG(10,("schedule_aio_write_and_X: failed to schedule "
 310                           "aio_write for file %s, offset %.0f, len = %u "
 311                           "(mid = %u)\n",
 312                           fsp->fsp_name, (double)startpos,
 313                           (unsigned int)numtowrite,
 314                           (unsigned int)req->mid ));
 315                 return False;
 316         }
 317
 318         inbufsize =  smb_len(req->inbuf) + 4;
 319         reply_outbuf(req, 6, 0);
 320         outbufsize = smb_len(req->outbuf) + 4;
 321         if (!(aio_ex = create_aio_ex_write(fsp, inbufsize, outbufsize,
 322                                            req->mid))) {
 323                 DEBUG(0,("schedule_aio_write_and_X: malloc fail.\n"));
 324                 return False;
 325         }
 326
 327         /* Copy the SMB header already setup in outbuf. */
 328         memcpy(aio_ex->inbuf, req->inbuf, inbufsize);
 329
 330         /* Copy the SMB header already setup in outbuf. */
 331         memcpy(aio_ex->outbuf, req->outbuf, outbufsize);
 332         TALLOC_FREE(req->outbuf);
 333         SCVAL(aio_ex->outbuf,smb_vwv0,0xFF); /* Never a chained reply. */
 334
 335         a = &aio_ex->acb;
 336
 337         /* Now set up the aio record for the write call. */
 338
 339         a->aio_fildes = fsp->fh->fd;
 340         a->aio_buf = aio_ex->inbuf + (PTR_DIFF(data, req->inbuf));
 341         a->aio_nbytes = numtowrite;
 342         a->aio_offset = startpos;
 343         a->aio_sigevent.sigev_notify = SIGEV_SIGNAL;
 344         a->aio_sigevent.sigev_signo  = RT_SIGNAL_AIO;
 345         a->aio_sigevent.sigev_value.sival_int = aio_ex->mid;
 346
 347         if (SMB_VFS_AIO_WRITE(fsp,a) == -1) {
 348                 DEBUG(3,("schedule_aio_wrote_and_X: aio_write failed. "
 349                          "Error %s\n", strerror(errno) ));
 350                 delete_aio_ex(aio_ex);
 351                 return False;
 352         }
 353
 354         if (!write_through && !lp_syncalways(SNUM(fsp->conn))
 355             && fsp->aio_write_behind) {
 356                 /* Lie to the client and immediately claim we finished the
 357                  * write. */
 358                 SSVAL(aio_ex->outbuf,smb_vwv2,numtowrite);
 359                 SSVAL(aio_ex->outbuf,smb_vwv4,(numtowrite>>16)&1);
 360                 show_msg(aio_ex->outbuf);
 361                 if (!srv_send_smb(smbd_server_fd(),aio_ex->outbuf,
 362                                 IS_CONN_ENCRYPTED(fsp->conn))) {
 363                         exit_server_cleanly("handle_aio_write: srv_send_smb "
 364                                             "failed.");
 365                 }
 366                 DEBUG(10,("schedule_aio_write_and_X: scheduled aio_write "
 367                           "behind for file %s\n", fsp->fsp_name ));
 368         } else {
 369                 srv_defer_sign_response(aio_ex->mid);
 370         }
 371         outstanding_aio_calls++;
 372
 373         DEBUG(10,("schedule_aio_write_and_X: scheduled aio_write for file "
 374                   "%s, offset %.0f, len = %u (mid = %u) "
 375                   "outstanding_aio_calls = %d\n",
 376                   fsp->fsp_name, (double)startpos, (unsigned int)numtowrite,
 377                   (unsigned int)aio_ex->mid, outstanding_aio_calls ));
 378
 379         return True;
 380 }
 381
 382
 383 /****************************************************************************
 384  Complete the read 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_read_complete(struct aio_extra *aio_ex)
 389 {
 390         int ret = 0;
 391         int outsize;
 392         char *outbuf = aio_ex->outbuf;
 393         char *data = smb_buf(outbuf);
 394         ssize_t nread = SMB_VFS_AIO_RETURN(aio_ex->fsp,&aio_ex->acb);
 395
 396         if (nread < 0) {
 397                 /* We're relying here on the fact that if the fd is
 398                    closed then the aio will complete and aio_return
 399                    will return an error. Hopefully this is
 400                    true.... JRA. */
 401
 402                 /* If errno is ECANCELED then don't return anything to the
 403                  * client. */
 404                 if (errno == ECANCELED) {
 405                         srv_cancel_sign_response(aio_ex->mid);
 406                         return 0;
 407                 }
 408
 409                 DEBUG( 3,( "handle_aio_read_complete: file %s nread == -1. "
 410                            "Error = %s\n",
 411                            aio_ex->fsp->fsp_name, strerror(errno) ));
 412
 413                 ret = errno;
 414                 ERROR_NT(map_nt_error_from_unix(ret));
 415                 outsize = srv_set_message(outbuf,0,0,true);
 416         } else {
 417                 outsize = srv_set_message(outbuf,12,nread,False);
 418                 SSVAL(outbuf,smb_vwv2,0xFFFF); /* Remaining - must be * -1. */
 419                 SSVAL(outbuf,smb_vwv5,nread);
 420                 SSVAL(outbuf,smb_vwv6,smb_offset(data,outbuf));
 421                 SSVAL(outbuf,smb_vwv7,((nread >> 16) & 1));
 422                 SSVAL(smb_buf(outbuf),-2,nread);
 423
 424                 DEBUG( 3, ( "handle_aio_read_complete file %s max=%d "
 425                             "nread=%d\n",
 426                             aio_ex->fsp->fsp_name,
 427                             (int)aio_ex->acb.aio_nbytes, (int)nread ) );
 428
 429         }
 430         smb_setlen(outbuf,outsize - 4);
 431         show_msg(outbuf);
 432         if (!srv_send_smb(smbd_server_fd(),outbuf,
 433                         IS_CONN_ENCRYPTED(aio_ex->fsp->conn))) {
 434                 exit_server_cleanly("handle_aio_read_complete: srv_send_smb "
 435                                     "failed.");
 436         }
 437
 438         DEBUG(10,("handle_aio_read_complete: scheduled aio_read completed "
 439                   "for file %s, offset %.0f, len = %u\n",
 440                   aio_ex->fsp->fsp_name, (double)aio_ex->acb.aio_offset,
 441                   (unsigned int)nread ));
 442
 443         return ret;
 444 }
 445
 446 /****************************************************************************
 447  Complete the write and return the data or error back to the client.
 448  Returns errno or zero if all ok.
 449 *****************************************************************************/
 450
 451 static int handle_aio_write_complete(struct aio_extra *aio_ex)
 452 {
 453         int ret = 0;
 454         files_struct *fsp = aio_ex->fsp;
 455         char *outbuf = aio_ex->outbuf;
 456         ssize_t numtowrite = aio_ex->acb.aio_nbytes;
 457         ssize_t nwritten = SMB_VFS_AIO_RETURN(fsp,&aio_ex->acb);
 458
 459         if (fsp->aio_write_behind) {
 460                 if (nwritten != numtowrite) {
 461                         if (nwritten == -1) {
 462                                 DEBUG(5,("handle_aio_write_complete: "
 463                                          "aio_write_behind failed ! File %s "
 464                                          "is corrupt ! Error %s\n",
 465                                          fsp->fsp_name, strerror(errno) ));
 466                                 ret = errno;
 467                         } else {
 468                                 DEBUG(0,("handle_aio_write_complete: "
 469                                          "aio_write_behind failed ! File %s "
 470                                          "is corrupt ! Wanted %u bytes but "
 471                                          "only wrote %d\n", fsp->fsp_name,
 472                                          (unsigned int)numtowrite,
 473                                          (int)nwritten ));
 474                                 ret = EIO;
 475                         }
 476                 } else {
 477                         DEBUG(10,("handle_aio_write_complete: "
 478                                   "aio_write_behind completed for file %s\n",
 479                                   fsp->fsp_name ));
 480                 }
 481                 return 0;
 482         }
 483
 484         /* We don't need outsize or set_message here as we've already set the
 485            fixed size length when we set up the aio call. */
 486
 487         if(nwritten == -1) {
 488                 DEBUG( 3,( "handle_aio_write: file %s wanted %u bytes. "
 489                            "nwritten == %d. Error = %s\n",
 490                            fsp->fsp_name, (unsigned int)numtowrite,
 491                            (int)nwritten, strerror(errno) ));
 492
 493                 /* If errno is ECANCELED then don't return anything to the
 494                  * client. */
 495                 if (errno == ECANCELED) {
 496                         srv_cancel_sign_response(aio_ex->mid);
 497                         return 0;
 498                 }
 499
 500                 ret = errno;
 501                 ERROR_BOTH(map_nt_error_from_unix(ret), ERRHRD, ERRdiskfull);
 502                 srv_set_message(outbuf,0,0,true);
 503         } else {
 504                 bool write_through = BITSETW(aio_ex->inbuf+smb_vwv7,0);
 505                 NTSTATUS status;
 506
 507                 SSVAL(outbuf,smb_vwv2,nwritten);
 508                 SSVAL(outbuf,smb_vwv4,(nwritten>>16)&1);
 509                 if (nwritten < (ssize_t)numtowrite) {
 510                         SCVAL(outbuf,smb_rcls,ERRHRD);
 511                         SSVAL(outbuf,smb_err,ERRdiskfull);
 512                 }
 513
 514                 DEBUG(3,("handle_aio_write: fnum=%d num=%d wrote=%d\n",
 515                          fsp->fnum, (int)numtowrite, (int)nwritten));
 516                 status = sync_file(fsp->conn,fsp, write_through);
 517                 if (!NT_STATUS_IS_OK(status)) {
 518                         ret = errno;
 519                         ERROR_BOTH(map_nt_error_from_unix(ret),
 520                                    ERRHRD, ERRdiskfull);
 521                         srv_set_message(outbuf,0,0,true);
 522                         DEBUG(5,("handle_aio_write: sync_file for %s returned %s\n",
 523                                 fsp->fsp_name, nt_errstr(status) ));
 524                 }
 525         }
 526
 527         show_msg(outbuf);
 528         if (!srv_send_smb(smbd_server_fd(),outbuf,IS_CONN_ENCRYPTED(fsp->conn))) {
 529                 exit_server_cleanly("handle_aio_write: srv_send_smb failed.");
 530         }
 531
 532         DEBUG(10,("handle_aio_write_complete: scheduled aio_write completed "
 533                   "for file %s, offset %.0f, requested %u, written = %u\n",
 534                   fsp->fsp_name, (double)aio_ex->acb.aio_offset,
 535                   (unsigned int)numtowrite, (unsigned int)nwritten ));
 536
 537         return ret;
 538 }
 539
 540 /****************************************************************************
 541  Handle any aio completion. Returns True if finished (and sets *perr if err
 542  was non-zero), False if not.
 543 *****************************************************************************/
 544
 545 static bool handle_aio_completed(struct aio_extra *aio_ex, int *perr)
 546 {
 547         int err;
 548
 549         /* Ensure the operation has really completed. */
 550         if (SMB_VFS_AIO_ERROR(aio_ex->fsp, &aio_ex->acb) == EINPROGRESS) {
 551                 DEBUG(10,( "handle_aio_completed: operation mid %u still in "
 552                            "process for file %s\n",
 553                            aio_ex->mid, aio_ex->fsp->fsp_name ));
 554                 return False;
 555         }
 556
 557         if (aio_ex->read_req) {
 558                 err = handle_aio_read_complete(aio_ex);
 559         } else {
 560                 err = handle_aio_write_complete(aio_ex);
 561         }
 562
 563         if (err) {
 564                 *perr = err; /* Only save non-zero errors. */
 565         }
 566
 567         return True;
 568 }
 569
 570 /****************************************************************************
 571  Handle any aio completion inline.
 572  Returns non-zero errno if fail or zero if all ok.
 573 *****************************************************************************/
 574
 575 int process_aio_queue(void)
 576 {
 577         int i;
 578         int ret = 0;
 579
 580         BlockSignals(True, RT_SIGNAL_AIO);
 581
 582         DEBUG(10,("process_aio_queue: signals_received = %d\n",
 583                   (int)signals_received));
 584         DEBUG(10,("process_aio_queue: outstanding_aio_calls = %d\n",
 585                   outstanding_aio_calls));
 586
 587         if (!signals_received) {
 588                 BlockSignals(False, RT_SIGNAL_AIO);
 589                 return 0;
 590         }
 591
 592         /* Drain all the complete aio_reads. */
 593         for (i = 0; i < signals_received; i++) {
 594                 uint16 mid = aio_pending_array[i];
 595                 files_struct *fsp = NULL;
 596                 struct aio_extra *aio_ex = find_aio_ex(mid);
 597
 598                 if (!aio_ex) {
 599                         DEBUG(3,("process_aio_queue: Can't find record to "
 600                                  "match mid %u.\n", (unsigned int)mid));
 601                         srv_cancel_sign_response(mid);
 602                         continue;
 603                 }
 604
 605                 fsp = aio_ex->fsp;
 606                 if (fsp == NULL) {
 607                         /* file was closed whilst I/O was outstanding. Just
 608                          * ignore. */
 609                         DEBUG( 3,( "process_aio_queue: file closed whilst "
 610                                    "aio outstanding.\n"));
 611                         srv_cancel_sign_response(mid);
 612                         continue;
 613                 }
 614
 615                 if (!handle_aio_completed(aio_ex, &ret)) {
 616                         continue;
 617                 }
 618
 619                 delete_aio_ex(aio_ex);
 620         }
 621
 622         outstanding_aio_calls -= signals_received;
 623         signals_received = 0;
 624         BlockSignals(False, RT_SIGNAL_AIO);
 625         return ret;
 626 }
 627
 628 /****************************************************************************
 629  We're doing write behind and the client closed the file. Wait up to 30
 630  seconds (my arbitrary choice) for the aio to complete. Return 0 if all writes
 631  completed, errno to return if not.
 632 *****************************************************************************/
 633
 634 #define SMB_TIME_FOR_AIO_COMPLETE_WAIT 29
 635
 636 int wait_for_aio_completion(files_struct *fsp)
 637 {
 638         struct aio_extra *aio_ex;
 639         const SMB_STRUCT_AIOCB **aiocb_list;
 640         int aio_completion_count = 0;
 641         time_t start_time = time(NULL);
 642         int seconds_left;
 643
 644         for (seconds_left = SMB_TIME_FOR_AIO_COMPLETE_WAIT;
 645              seconds_left >= 0;) {
 646                 int err = 0;
 647                 int i;
 648                 struct timespec ts;
 649
 650                 aio_completion_count = 0;
 651                 for( aio_ex = aio_list_head; aio_ex; aio_ex = aio_ex->next) {
 652                         if (aio_ex->fsp == fsp) {
 653                                 aio_completion_count++;
 654                         }
 655                 }
 656
 657                 if (!aio_completion_count) {
 658                         return 0;
 659                 }
 660
 661                 DEBUG(3,("wait_for_aio_completion: waiting for %d aio events "
 662                          "to complete.\n", aio_completion_count ));
 663
 664                 aiocb_list = SMB_MALLOC_ARRAY(const SMB_STRUCT_AIOCB *,
 665                                               aio_completion_count);
 666                 if (!aiocb_list) {
 667                         return ENOMEM;
 668                 }
 669
 670                 for( i = 0, aio_ex = aio_list_head;
 671                      aio_ex;
 672                      aio_ex = aio_ex->next) {
 673                         if (aio_ex->fsp == fsp) {
 674                                 aiocb_list[i++] = &aio_ex->acb;
 675                         }
 676                 }
 677
 678                 /* Now wait up to seconds_left for completion. */
 679                 ts.tv_sec = seconds_left;
 680                 ts.tv_nsec = 0;
 681
 682                 DEBUG(10,("wait_for_aio_completion: %d events, doing a wait "
 683                           "of %d seconds.\n",
 684                           aio_completion_count, seconds_left ));
 685
 686                 err = SMB_VFS_AIO_SUSPEND(fsp, aiocb_list,
 687                                           aio_completion_count, &ts);
 688
 689                 DEBUG(10,("wait_for_aio_completion: returned err = %d, "
 690                           "errno = %s\n", err, strerror(errno) ));
 691
 692                 if (err == -1 && errno == EAGAIN) {
 693                         DEBUG(0,("wait_for_aio_completion: aio_suspend timed "
 694                                  "out waiting for %d events after a wait of "
 695                                  "%d seconds\n", aio_completion_count,
 696                                  seconds_left));
 697                         /* Timeout. */
 698                         cancel_aio_by_fsp(fsp);
 699                         SAFE_FREE(aiocb_list);
 700                         return EIO;
 701                 }
 702
 703                 /* One or more events might have completed - process them if
 704                  * so. */
 705                 for( i = 0; i < aio_completion_count; i++) {
 706                         uint16 mid = aiocb_list[i]->aio_sigevent.sigev_value.sival_int;
 707
 708                         aio_ex = find_aio_ex(mid);
 709
 710                         if (!aio_ex) {
 711                                 DEBUG(0, ("wait_for_aio_completion: mid %u "
 712                                           "doesn't match an aio record\n",
 713                                           (unsigned int)mid ));
 714                                 continue;
 715                         }
 716
 717                         if (!handle_aio_completed(aio_ex, &err)) {
 718                                 continue;
 719                         }
 720                         delete_aio_ex(aio_ex);
 721                 }
 722
 723                 SAFE_FREE(aiocb_list);
 724                 seconds_left = SMB_TIME_FOR_AIO_COMPLETE_WAIT
 725                         - (time(NULL) - start_time);
 726         }
 727
 728         /* We timed out - we don't know why. Return ret if already an error,
 729          * else EIO. */
 730         DEBUG(10,("wait_for_aio_completion: aio_suspend timed out waiting "
 731                   "for %d events\n",
 732                   aio_completion_count));
 733
 734         return EIO;
 735 }
 736
 737 /****************************************************************************
 738  Cancel any outstanding aio requests. The client doesn't care about the reply.
 739 *****************************************************************************/
 740
 741 void cancel_aio_by_fsp(files_struct *fsp)
 742 {
 743         struct aio_extra *aio_ex;
 744
 745         for( aio_ex = aio_list_head; aio_ex; aio_ex = aio_ex->next) {
 746                 if (aio_ex->fsp == fsp) {
 747                         /* Don't delete the aio_extra record as we may have
 748                            completed and don't yet know it. Just do the
 749                            aio_cancel call and return. */
 750                         SMB_VFS_AIO_CANCEL(fsp, &aio_ex->acb);
 751                         aio_ex->fsp = NULL; /* fsp will be closed when we
 752                                              * return. */
 753                 }
 754         }
 755 }
 756
 757 #else
 758 bool aio_finished(void)
 759 {
 760         return False;
 761 }
 762
 763 void initialize_async_io_handler(void)
 764 {
 765 }
 766
 767 int process_aio_queue(void)
 768 {
 769         return False;
 770 }
 771
 772 bool schedule_aio_read_and_X(connection_struct *conn,
 773                              struct smb_request *req,
 774                              files_struct *fsp, SMB_OFF_T startpos,
 775                              size_t smb_maxcnt)
 776 {
 777         return False;
 778 }
 779
 780 bool schedule_aio_write_and_X(connection_struct *conn,
 781                               struct smb_request *req,
 782                               files_struct *fsp, char *data,
 783                               SMB_OFF_T startpos,
 784                               size_t numtowrite)
 785 {
 786         return False;
 787 }
 788
 789 void cancel_aio_by_fsp(files_struct *fsp)
 790 {
 791 }
 792
 793 int wait_for_aio_completion(files_struct *fsp)
 794 {
 795         return ENOSYS;
 796 }
 797 #endif