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
  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 static int aio_pending_size;
 145 static sig_atomic_t signals_received;
 146 static int outstanding_aio_calls;
 147 static uint16 *aio_pending_array;
 148
 149 /****************************************************************************
 150  Signal handler when an aio request completes.
 151 *****************************************************************************/
 152
 153 void aio_request_done(uint16_t mid)
 154 {
 155         if (signals_received < aio_pending_size) {
 156                 aio_pending_array[signals_received] = mid;
 157                 signals_received++;
 158         }
 159         /* Else signal is lost. */
 160 }
 161
 162 static void signal_handler(int sig, siginfo_t *info, void *unused)
 163 {
 164         aio_request_done(info->si_value.sival_int);
 165         sys_select_signal(RT_SIGNAL_AIO);
 166 }
 167
 168 /****************************************************************************
 169  Is there a signal waiting ?
 170 *****************************************************************************/
 171
 172 bool aio_finished(void)
 173 {
 174         return (signals_received != 0);
 175 }
 176
 177 /****************************************************************************
 178  Initialize the signal handler for aio read/write.
 179 *****************************************************************************/
 180
 181 void initialize_async_io_handler(void)
 182 {
 183         struct sigaction act;
 184
 185         aio_pending_size = lp_maxmux();
 186         aio_pending_array = SMB_MALLOC_ARRAY(uint16, aio_pending_size);
 187         SMB_ASSERT(aio_pending_array != NULL);
 188
 189         ZERO_STRUCT(act);
 190         act.sa_sigaction = signal_handler;
 191         act.sa_flags = SA_SIGINFO;
 192         sigemptyset( &act.sa_mask );
 193         if (sigaction(RT_SIGNAL_AIO, &act, NULL) != 0) {
 194                 DEBUG(0,("Failed to setup RT_SIGNAL_AIO handler\n"));
 195         }
 196
 197         /* the signal can start off blocked due to a bug in bash */
 198         BlockSignals(False, RT_SIGNAL_AIO);
 199 }
 200
 201 /****************************************************************************
 202  Set up an aio request from a SMBreadX call.
 203 *****************************************************************************/
 204
 205 bool schedule_aio_read_and_X(connection_struct *conn,
 206                              struct smb_request *req,
 207                              files_struct *fsp, SMB_OFF_T startpos,
 208                              size_t smb_maxcnt)
 209 {
 210         struct aio_extra *aio_ex;
 211         SMB_STRUCT_AIOCB *a;
 212         size_t bufsize;
 213         size_t min_aio_read_size = lp_aio_read_size(SNUM(conn));
 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_read_size || (smb_maxcnt < min_aio_read_size))
 222             && !SMB_VFS_AIO_FORCE(fsp)) {
 223                 /* Too small a read for aio request. */
 224                 DEBUG(10,("schedule_aio_read_and_X: read size (%u) too small "
 225                           "for minimum aio_read of %u\n",
 226                           (unsigned int)smb_maxcnt,
 227                           (unsigned int)min_aio_read_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 (chain_size !=0 || (CVAL(req->inbuf,smb_vwv0) != 0xFF)
 234             || (lp_write_cache_size(SNUM(conn)) != 0) ) {
 235                 return False;
 236         }
 237
 238         if (outstanding_aio_calls >= aio_pending_size) {
 239                 DEBUG(10,("schedule_aio_read_and_X: Already have %d aio "
 240                           "activities outstanding.\n",
 241                           outstanding_aio_calls ));
 242                 return False;
 243         }
 244
 245         /* The following is safe from integer wrap as we've already checked
 246            smb_maxcnt is 128k or less. Wct is 12 for read replies */
 247
 248         bufsize = smb_size + 12 * 2 + smb_maxcnt;
 249
 250         if ((aio_ex = create_aio_ex_read(fsp, bufsize, req->mid)) == NULL) {
 251                 DEBUG(10,("schedule_aio_read_and_X: malloc fail.\n"));
 252                 return False;
 253         }
 254
 255         construct_reply_common((char *)req->inbuf, aio_ex->outbuf);
 256         srv_set_message(aio_ex->outbuf, 12, 0, True);
 257         SCVAL(aio_ex->outbuf,smb_vwv0,0xFF); /* Never a chained reply. */
 258
 259         a = &aio_ex->acb;
 260
 261         /* Now set up the aio record for the read call. */
 262
 263         a->aio_fildes = fsp->fh->fd;
 264         a->aio_buf = smb_buf(aio_ex->outbuf);
 265         a->aio_nbytes = smb_maxcnt;
 266         a->aio_offset = startpos;
 267         a->aio_sigevent.sigev_notify = SIGEV_SIGNAL;
 268         a->aio_sigevent.sigev_signo  = RT_SIGNAL_AIO;
 269         a->aio_sigevent.sigev_value.sival_int = aio_ex->mid;
 270
 271         if (SMB_VFS_AIO_READ(fsp,a) == -1) {
 272                 DEBUG(0,("schedule_aio_read_and_X: aio_read failed. "
 273                          "Error %s\n", strerror(errno) ));
 274                 delete_aio_ex(aio_ex);
 275                 return False;
 276         }
 277
 278         DEBUG(10,("schedule_aio_read_and_X: scheduled aio_read for file %s, "
 279                   "offset %.0f, len = %u (mid = %u)\n",
 280                   fsp->fsp_name, (double)startpos, (unsigned int)smb_maxcnt,
 281                   (unsigned int)aio_ex->mid ));
 282
 283         srv_defer_sign_response(aio_ex->mid);
 284         outstanding_aio_calls++;
 285         return True;
 286 }
 287
 288 /****************************************************************************
 289  Set up an aio request from a SMBwriteX call.
 290 *****************************************************************************/
 291
 292 bool schedule_aio_write_and_X(connection_struct *conn,
 293                               struct smb_request *req,
 294                               files_struct *fsp, char *data,
 295                               SMB_OFF_T startpos,
 296                               size_t numtowrite)
 297 {
 298         struct aio_extra *aio_ex;
 299         SMB_STRUCT_AIOCB *a;
 300         size_t inbufsize, outbufsize;
 301         bool write_through = BITSETW(req->inbuf+smb_vwv7,0);
 302         size_t min_aio_write_size = lp_aio_write_size(SNUM(conn));
 303
 304         if (fsp->base_fsp != NULL) {
 305                 /* No AIO on streams yet */
 306                 DEBUG(10, ("AIO on streams not yet supported\n"));
 307                 return false;
 308         }
 309
 310         if ((!min_aio_write_size || (numtowrite < min_aio_write_size))
 311             && !SMB_VFS_AIO_FORCE(fsp)) {
 312                 /* Too small a write for aio request. */
 313                 DEBUG(10,("schedule_aio_write_and_X: write size (%u) too "
 314                           "small for minimum aio_write of %u\n",
 315                           (unsigned int)numtowrite,
 316                           (unsigned int)min_aio_write_size ));
 317                 return False;
 318         }
 319
 320         /* Only do this on non-chained and non-chaining reads not using the
 321          * write cache. */
 322         if (chain_size !=0 || (CVAL(req->inbuf,smb_vwv0) != 0xFF)
 323             || (lp_write_cache_size(SNUM(conn)) != 0) ) {
 324                 return False;
 325         }
 326
 327         if (outstanding_aio_calls >= aio_pending_size) {
 328                 DEBUG(3,("schedule_aio_write_and_X: Already have %d aio "
 329                          "activities outstanding.\n",
 330                           outstanding_aio_calls ));
 331                 DEBUG(10,("schedule_aio_write_and_X: failed to schedule "
 332                           "aio_write for file %s, offset %.0f, len = %u "
 333                           "(mid = %u)\n",
 334                           fsp->fsp_name, (double)startpos,
 335                           (unsigned int)numtowrite,
 336                           (unsigned int)req->mid ));
 337                 return False;
 338         }
 339
 340         inbufsize =  smb_len(req->inbuf) + 4;
 341         reply_outbuf(req, 6, 0);
 342         outbufsize = smb_len(req->outbuf) + 4;
 343         if (!(aio_ex = create_aio_ex_write(fsp, inbufsize, outbufsize,
 344                                            req->mid))) {
 345                 DEBUG(0,("schedule_aio_write_and_X: malloc fail.\n"));
 346                 return False;
 347         }
 348
 349         /* Copy the SMB header already setup in outbuf. */
 350         memcpy(aio_ex->inbuf, req->inbuf, inbufsize);
 351
 352         /* Copy the SMB header already setup in outbuf. */
 353         memcpy(aio_ex->outbuf, req->outbuf, outbufsize);
 354         TALLOC_FREE(req->outbuf);
 355         SCVAL(aio_ex->outbuf,smb_vwv0,0xFF); /* Never a chained reply. */
 356
 357         a = &aio_ex->acb;
 358
 359         /* Now set up the aio record for the write call. */
 360
 361         a->aio_fildes = fsp->fh->fd;
 362         a->aio_buf = aio_ex->inbuf + (PTR_DIFF(data, req->inbuf));
 363         a->aio_nbytes = numtowrite;
 364         a->aio_offset = startpos;
 365         a->aio_sigevent.sigev_notify = SIGEV_SIGNAL;
 366         a->aio_sigevent.sigev_signo  = RT_SIGNAL_AIO;
 367         a->aio_sigevent.sigev_value.sival_int = aio_ex->mid;
 368
 369         if (SMB_VFS_AIO_WRITE(fsp,a) == -1) {
 370                 DEBUG(3,("schedule_aio_wrote_and_X: aio_write failed. "
 371                          "Error %s\n", strerror(errno) ));
 372                 delete_aio_ex(aio_ex);
 373                 return False;
 374         }
 375
 376         release_level_2_oplocks_on_change(fsp);
 377
 378         if (!write_through && !lp_syncalways(SNUM(fsp->conn))
 379             && fsp->aio_write_behind) {
 380                 /* Lie to the client and immediately claim we finished the
 381                  * write. */
 382                 SSVAL(aio_ex->outbuf,smb_vwv2,numtowrite);
 383                 SSVAL(aio_ex->outbuf,smb_vwv4,(numtowrite>>16)&1);
 384                 show_msg(aio_ex->outbuf);
 385                 if (!srv_send_smb(smbd_server_fd(),aio_ex->outbuf,
 386                                 IS_CONN_ENCRYPTED(fsp->conn))) {
 387                         exit_server_cleanly("handle_aio_write: srv_send_smb "
 388                                             "failed.");
 389                 }
 390                 DEBUG(10,("schedule_aio_write_and_X: scheduled aio_write "
 391                           "behind for file %s\n", fsp->fsp_name ));
 392         } else {
 393                 srv_defer_sign_response(aio_ex->mid);
 394         }
 395         outstanding_aio_calls++;
 396
 397         DEBUG(10,("schedule_aio_write_and_X: scheduled aio_write for file "
 398                   "%s, offset %.0f, len = %u (mid = %u) "
 399                   "outstanding_aio_calls = %d\n",
 400                   fsp->fsp_name, (double)startpos, (unsigned int)numtowrite,
 401                   (unsigned int)aio_ex->mid, outstanding_aio_calls ));
 402
 403         return True;
 404 }
 405
 406
 407 /****************************************************************************
 408  Complete the read and return the data or error back to the client.
 409  Returns errno or zero if all ok.
 410 *****************************************************************************/
 411
 412 static int handle_aio_read_complete(struct aio_extra *aio_ex)
 413 {
 414         int ret = 0;
 415         int outsize;
 416         char *outbuf = aio_ex->outbuf;
 417         char *data = smb_buf(outbuf);
 418         ssize_t nread = SMB_VFS_AIO_RETURN(aio_ex->fsp,&aio_ex->acb);
 419
 420         if (nread < 0) {
 421                 /* We're relying here on the fact that if the fd is
 422                    closed then the aio will complete and aio_return
 423                    will return an error. Hopefully this is
 424                    true.... JRA. */
 425
 426                 /* If errno is ECANCELED then don't return anything to the
 427                  * client. */
 428                 if (errno == ECANCELED) {
 429                         srv_cancel_sign_response(aio_ex->mid);
 430                         return 0;
 431                 }
 432
 433                 DEBUG( 3,( "handle_aio_read_complete: file %s nread == -1. "
 434                            "Error = %s\n",
 435                            aio_ex->fsp->fsp_name, strerror(errno) ));
 436
 437                 ret = errno;
 438                 ERROR_NT(map_nt_error_from_unix(ret));
 439                 outsize = srv_set_message(outbuf,0,0,true);
 440         } else {
 441                 outsize = srv_set_message(outbuf,12,nread,False);
 442                 SSVAL(outbuf,smb_vwv2,0xFFFF); /* Remaining - must be * -1. */
 443                 SSVAL(outbuf,smb_vwv5,nread);
 444                 SSVAL(outbuf,smb_vwv6,smb_offset(data,outbuf));
 445                 SSVAL(outbuf,smb_vwv7,((nread >> 16) & 1));
 446                 SSVAL(smb_buf(outbuf),-2,nread);
 447
 448                 aio_ex->fsp->fh->pos = aio_ex->acb.aio_offset + nread;
 449                 aio_ex->fsp->fh->position_information = aio_ex->fsp->fh->pos;
 450
 451                 DEBUG( 3, ( "handle_aio_read_complete file %s max=%d "
 452                             "nread=%d\n",
 453                             aio_ex->fsp->fsp_name,
 454                             (int)aio_ex->acb.aio_nbytes, (int)nread ) );
 455
 456         }
 457         smb_setlen(outbuf,outsize - 4);
 458         show_msg(outbuf);
 459         if (!srv_send_smb(smbd_server_fd(),outbuf,
 460                         IS_CONN_ENCRYPTED(aio_ex->fsp->conn))) {
 461                 exit_server_cleanly("handle_aio_read_complete: srv_send_smb "
 462                                     "failed.");
 463         }
 464
 465         DEBUG(10,("handle_aio_read_complete: scheduled aio_read completed "
 466                   "for file %s, offset %.0f, len = %u\n",
 467                   aio_ex->fsp->fsp_name, (double)aio_ex->acb.aio_offset,
 468                   (unsigned int)nread ));
 469
 470         return ret;
 471 }
 472
 473 /****************************************************************************
 474  Complete the write and return the data or error back to the client.
 475  Returns errno or zero if all ok.
 476 *****************************************************************************/
 477
 478 static int handle_aio_write_complete(struct aio_extra *aio_ex)
 479 {
 480         int ret = 0;
 481         files_struct *fsp = aio_ex->fsp;
 482         char *outbuf = aio_ex->outbuf;
 483         ssize_t numtowrite = aio_ex->acb.aio_nbytes;
 484         ssize_t nwritten = SMB_VFS_AIO_RETURN(fsp,&aio_ex->acb);
 485
 486         if (fsp->aio_write_behind) {
 487                 if (nwritten != numtowrite) {
 488                         if (nwritten == -1) {
 489                                 DEBUG(5,("handle_aio_write_complete: "
 490                                          "aio_write_behind failed ! File %s "
 491                                          "is corrupt ! Error %s\n",
 492                                          fsp->fsp_name, strerror(errno) ));
 493                                 ret = errno;
 494                         } else {
 495                                 DEBUG(0,("handle_aio_write_complete: "
 496                                          "aio_write_behind failed ! File %s "
 497                                          "is corrupt ! Wanted %u bytes but "
 498                                          "only wrote %d\n", fsp->fsp_name,
 499                                          (unsigned int)numtowrite,
 500                                          (int)nwritten ));
 501                                 ret = EIO;
 502                         }
 503                 } else {
 504                         DEBUG(10,("handle_aio_write_complete: "
 505                                   "aio_write_behind completed for file %s\n",
 506                                   fsp->fsp_name ));
 507                 }
 508                 return 0;
 509         }
 510
 511         /* We don't need outsize or set_message here as we've already set the
 512            fixed size length when we set up the aio call. */
 513
 514         if(nwritten == -1) {
 515                 DEBUG( 3,( "handle_aio_write: file %s wanted %u bytes. "
 516                            "nwritten == %d. Error = %s\n",
 517                            fsp->fsp_name, (unsigned int)numtowrite,
 518                            (int)nwritten, strerror(errno) ));
 519
 520                 /* If errno is ECANCELED then don't return anything to the
 521                  * client. */
 522                 if (errno == ECANCELED) {
 523                         srv_cancel_sign_response(aio_ex->mid);
 524                         return 0;
 525                 }
 526
 527                 ret = errno;
 528                 ERROR_BOTH(map_nt_error_from_unix(ret), ERRHRD, ERRdiskfull);
 529                 srv_set_message(outbuf,0,0,true);
 530         } else {
 531                 bool write_through = BITSETW(aio_ex->inbuf+smb_vwv7,0);
 532                 NTSTATUS status;
 533
 534                 SSVAL(outbuf,smb_vwv2,nwritten);
 535                 SSVAL(outbuf,smb_vwv4,(nwritten>>16)&1);
 536                 if (nwritten < (ssize_t)numtowrite) {
 537                         SCVAL(outbuf,smb_rcls,ERRHRD);
 538                         SSVAL(outbuf,smb_err,ERRdiskfull);
 539                 }
 540
 541                 DEBUG(3,("handle_aio_write: fnum=%d num=%d wrote=%d\n",
 542                          fsp->fnum, (int)numtowrite, (int)nwritten));
 543                 status = sync_file(fsp->conn,fsp, write_through);
 544                 if (!NT_STATUS_IS_OK(status)) {
 545                         ret = errno;
 546                         ERROR_BOTH(map_nt_error_from_unix(ret),
 547                                    ERRHRD, ERRdiskfull);
 548                         srv_set_message(outbuf,0,0,true);
 549                         DEBUG(5,("handle_aio_write: sync_file for %s returned %s\n",
 550                                 fsp->fsp_name, nt_errstr(status) ));
 551                 }
 552
 553                 aio_ex->fsp->fh->pos = aio_ex->acb.aio_offset + nwritten;
 554         }
 555
 556         show_msg(outbuf);
 557         if (!srv_send_smb(smbd_server_fd(),outbuf,IS_CONN_ENCRYPTED(fsp->conn))) {
 558                 exit_server_cleanly("handle_aio_write: srv_send_smb failed.");
 559         }
 560
 561         DEBUG(10,("handle_aio_write_complete: scheduled aio_write completed "
 562                   "for file %s, offset %.0f, requested %u, written = %u\n",
 563                   fsp->fsp_name, (double)aio_ex->acb.aio_offset,
 564                   (unsigned int)numtowrite, (unsigned int)nwritten ));
 565
 566         return ret;
 567 }
 568
 569 /****************************************************************************
 570  Handle any aio completion. Returns True if finished (and sets *perr if err
 571  was non-zero), False if not.
 572 *****************************************************************************/
 573
 574 static bool handle_aio_completed(struct aio_extra *aio_ex, int *perr)
 575 {
 576         int err;
 577
 578         /* Ensure the operation has really completed. */
 579         if (SMB_VFS_AIO_ERROR(aio_ex->fsp, &aio_ex->acb) == EINPROGRESS) {
 580                 DEBUG(10,( "handle_aio_completed: operation mid %u still in "
 581                            "process for file %s\n",
 582                            aio_ex->mid, aio_ex->fsp->fsp_name ));
 583                 return False;
 584         }
 585
 586         if (aio_ex->read_req) {
 587                 err = handle_aio_read_complete(aio_ex);
 588         } else {
 589                 err = handle_aio_write_complete(aio_ex);
 590         }
 591
 592         if (err) {
 593                 *perr = err; /* Only save non-zero errors. */
 594         }
 595
 596         return True;
 597 }
 598
 599 /****************************************************************************
 600  Handle any aio completion inline.
 601  Returns non-zero errno if fail or zero if all ok.
 602 *****************************************************************************/
 603
 604 int process_aio_queue(void)
 605 {
 606         int i;
 607         int ret = 0;
 608
 609         BlockSignals(True, RT_SIGNAL_AIO);
 610
 611         DEBUG(10,("process_aio_queue: signals_received = %d\n",
 612                   (int)signals_received));
 613         DEBUG(10,("process_aio_queue: outstanding_aio_calls = %d\n",
 614                   outstanding_aio_calls));
 615
 616         if (!signals_received) {
 617                 BlockSignals(False, RT_SIGNAL_AIO);
 618                 return 0;
 619         }
 620
 621         /* Drain all the complete aio_reads. */
 622         for (i = 0; i < signals_received; i++) {
 623                 uint16 mid = aio_pending_array[i];
 624                 files_struct *fsp = NULL;
 625                 struct aio_extra *aio_ex = find_aio_ex(mid);
 626
 627                 if (!aio_ex) {
 628                         DEBUG(3,("process_aio_queue: Can't find record to "
 629                                  "match mid %u.\n", (unsigned int)mid));
 630                         srv_cancel_sign_response(mid);
 631                         continue;
 632                 }
 633
 634                 fsp = aio_ex->fsp;
 635                 if (fsp == NULL) {
 636                         /* file was closed whilst I/O was outstanding. Just
 637                          * ignore. */
 638                         DEBUG( 3,( "process_aio_queue: file closed whilst "
 639                                    "aio outstanding.\n"));
 640                         srv_cancel_sign_response(mid);
 641                         continue;
 642                 }
 643
 644                 if (!handle_aio_completed(aio_ex, &ret)) {
 645                         continue;
 646                 }
 647
 648                 delete_aio_ex(aio_ex);
 649         }
 650
 651         outstanding_aio_calls -= signals_received;
 652         signals_received = 0;
 653         BlockSignals(False, RT_SIGNAL_AIO);
 654         return ret;
 655 }
 656
 657 /****************************************************************************
 658  We're doing write behind and the client closed the file. Wait up to 30
 659  seconds (my arbitrary choice) for the aio to complete. Return 0 if all writes
 660  completed, errno to return if not.
 661 *****************************************************************************/
 662
 663 #define SMB_TIME_FOR_AIO_COMPLETE_WAIT 29
 664
 665 int wait_for_aio_completion(files_struct *fsp)
 666 {
 667         struct aio_extra *aio_ex;
 668         const SMB_STRUCT_AIOCB **aiocb_list;
 669         int aio_completion_count = 0;
 670         time_t start_time = time(NULL);
 671         int seconds_left;
 672
 673         for (seconds_left = SMB_TIME_FOR_AIO_COMPLETE_WAIT;
 674              seconds_left >= 0;) {
 675                 int err = 0;
 676                 int i;
 677                 struct timespec ts;
 678
 679                 aio_completion_count = 0;
 680                 for( aio_ex = aio_list_head; aio_ex; aio_ex = aio_ex->next) {
 681                         if (aio_ex->fsp == fsp) {
 682                                 aio_completion_count++;
 683                         }
 684                 }
 685
 686                 if (!aio_completion_count) {
 687                         return 0;
 688                 }
 689
 690                 DEBUG(3,("wait_for_aio_completion: waiting for %d aio events "
 691                          "to complete.\n", aio_completion_count ));
 692
 693                 aiocb_list = SMB_MALLOC_ARRAY(const SMB_STRUCT_AIOCB *,
 694                                               aio_completion_count);
 695                 if (!aiocb_list) {
 696                         return ENOMEM;
 697                 }
 698
 699                 for( i = 0, aio_ex = aio_list_head;
 700                      aio_ex;
 701                      aio_ex = aio_ex->next) {
 702                         if (aio_ex->fsp == fsp) {
 703                                 aiocb_list[i++] = &aio_ex->acb;
 704                         }
 705                 }
 706
 707                 /* Now wait up to seconds_left for completion. */
 708                 ts.tv_sec = seconds_left;
 709                 ts.tv_nsec = 0;
 710
 711                 DEBUG(10,("wait_for_aio_completion: %d events, doing a wait "
 712                           "of %d seconds.\n",
 713                           aio_completion_count, seconds_left ));
 714
 715                 err = SMB_VFS_AIO_SUSPEND(fsp, aiocb_list,
 716                                           aio_completion_count, &ts);
 717
 718                 DEBUG(10,("wait_for_aio_completion: returned err = %d, "
 719                           "errno = %s\n", err, strerror(errno) ));
 720
 721                 if (err == -1 && errno == EAGAIN) {
 722                         DEBUG(0,("wait_for_aio_completion: aio_suspend timed "
 723                                  "out waiting for %d events after a wait of "
 724                                  "%d seconds\n", aio_completion_count,
 725                                  seconds_left));
 726                         /* Timeout. */
 727                         cancel_aio_by_fsp(fsp);
 728                         SAFE_FREE(aiocb_list);
 729                         return EIO;
 730                 }
 731
 732                 /* One or more events might have completed - process them if
 733                  * so. */
 734                 for( i = 0; i < aio_completion_count; i++) {
 735                         uint16 mid = aiocb_list[i]->aio_sigevent.sigev_value.sival_int;
 736
 737                         aio_ex = find_aio_ex(mid);
 738
 739                         if (!aio_ex) {
 740                                 DEBUG(0, ("wait_for_aio_completion: mid %u "
 741                                           "doesn't match an aio record\n",
 742                                           (unsigned int)mid ));
 743                                 continue;
 744                         }
 745
 746                         if (!handle_aio_completed(aio_ex, &err)) {
 747                                 continue;
 748                         }
 749                         delete_aio_ex(aio_ex);
 750                 }
 751
 752                 SAFE_FREE(aiocb_list);
 753                 seconds_left = SMB_TIME_FOR_AIO_COMPLETE_WAIT
 754                         - (time(NULL) - start_time);
 755         }
 756
 757         /* We timed out - we don't know why. Return ret if already an error,
 758          * else EIO. */
 759         DEBUG(10,("wait_for_aio_completion: aio_suspend timed out waiting "
 760                   "for %d events\n",
 761                   aio_completion_count));
 762
 763         return EIO;
 764 }
 765
 766 /****************************************************************************
 767  Cancel any outstanding aio requests. The client doesn't care about the reply.
 768 *****************************************************************************/
 769
 770 void cancel_aio_by_fsp(files_struct *fsp)
 771 {
 772         struct aio_extra *aio_ex;
 773
 774         for( aio_ex = aio_list_head; aio_ex; aio_ex = aio_ex->next) {
 775                 if (aio_ex->fsp == fsp) {
 776                         /* Don't delete the aio_extra record as we may have
 777                            completed and don't yet know it. Just do the
 778                            aio_cancel call and return. */
 779                         SMB_VFS_AIO_CANCEL(fsp, &aio_ex->acb);
 780                         aio_ex->fsp = NULL; /* fsp will be closed when we
 781                                              * return. */
 782                 }
 783         }
 784 }
 785
 786 #else
 787 bool aio_finished(void)
 788 {
 789         return False;
 790 }
 791
 792 void initialize_async_io_handler(void)
 793 {
 794 }
 795
 796 int process_aio_queue(void)
 797 {
 798         return False;
 799 }
 800
 801 bool schedule_aio_read_and_X(connection_struct *conn,
 802                              struct smb_request *req,
 803                              files_struct *fsp, SMB_OFF_T startpos,
 804                              size_t smb_maxcnt)
 805 {
 806         return False;
 807 }
 808
 809 bool schedule_aio_write_and_X(connection_struct *conn,
 810                               struct smb_request *req,
 811                               files_struct *fsp, char *data,
 812                               SMB_OFF_T startpos,
 813                               size_t numtowrite)
 814 {
 815         return False;
 816 }
 817
 818 void cancel_aio_by_fsp(files_struct *fsp)
 819 {
 820 }
 821
 822 int wait_for_aio_completion(files_struct *fsp)
 823 {
 824         return ENOSYS;
 825 }
 826 #endif