root/source3/smbd/aio.c

/* [<][>][^][v][top][bottom][index][help] */

DEFINITIONS

This source file includes following definitions.
  1. aio_extra_destructor
  2. create_aio_extra
  3. find_aio_ex
  4. schedule_aio_read_and_X
  5. schedule_aio_write_and_X
  6. handle_aio_read_complete
  7. handle_aio_write_complete
  8. handle_aio_completed
  9. smbd_aio_complete_mid
  10. smbd_aio_signal_handler
  11. wait_for_aio_completion
  12. cancel_aio_by_fsp
  13. initialize_async_io_handler
  14. initialize_async_io_handler
  15. schedule_aio_read_and_X
  16. schedule_aio_write_and_X
  17. cancel_aio_by_fsp
  18. wait_for_aio_completion

   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 #ifndef SIGRTMIN
  29 #define SIGRTMIN        NSIG
  30 #endif
  31 #define RT_SIGNAL_AIO   (SIGRTMIN+3)
  32 #endif
  33 
  34 #ifndef HAVE_STRUCT_SIGEVENT_SIGEV_VALUE_SIVAL_PTR
  35 #ifdef HAVE_STRUCT_SIGEVENT_SIGEV_VALUE_SIGVAL_PTR
  36 #define sival_int       sigval_int
  37 #define sival_ptr       sigval_ptr
  38 #endif
  39 #endif
  40 
  41 /****************************************************************************
  42  The buffer we keep around whilst an aio request is in process.
  43 *****************************************************************************/
  44 
  45 struct aio_extra {
  46         struct aio_extra *next, *prev;
  47         SMB_STRUCT_AIOCB acb;
  48         files_struct *fsp;
  49         struct smb_request *req;
  50         char *outbuf;
  51         int (*handle_completion)(struct aio_extra *ex, int errcode);
  52 };
  53 
  54 static int handle_aio_read_complete(struct aio_extra *aio_ex, int errcode);
  55 static int handle_aio_write_complete(struct aio_extra *aio_ex, int errcode);
  56 
  57 static int aio_extra_destructor(struct aio_extra *aio_ex)
     /* [<][>][^][v][top][bottom][index][help] */
  58 {
  59         DLIST_REMOVE(aio_list_head, aio_ex);
  60         return 0;
  61 }
  62 
  63 /****************************************************************************
  64  Create the extended aio struct we must keep around for the lifetime
  65  of the aio call.
  66 *****************************************************************************/
  67 
  68 static struct aio_extra *create_aio_extra(files_struct *fsp, size_t buflen)
     /* [<][>][^][v][top][bottom][index][help] */
  69 {
  70         struct aio_extra *aio_ex = TALLOC_ZERO_P(NULL, struct aio_extra);
  71 
  72         if (!aio_ex) {
  73                 return NULL;
  74         }
  75 
  76         /* The output buffer stored in the aio_ex is the start of
  77            the smb return buffer. The buffer used in the acb
  78            is the start of the reply data portion of that buffer. */
  79 
  80         aio_ex->outbuf = TALLOC_ARRAY(aio_ex, char, buflen);
  81         if (!aio_ex->outbuf) {
  82                 TALLOC_FREE(aio_ex);
  83                 return NULL;
  84         }
  85         DLIST_ADD(aio_list_head, aio_ex);
  86         talloc_set_destructor(aio_ex, aio_extra_destructor);
  87         aio_ex->fsp = fsp;
  88         return aio_ex;
  89 }
  90 
  91 /****************************************************************************
  92  Given the mid find the extended aio struct containing it.
  93 *****************************************************************************/
  94 
  95 static struct aio_extra *find_aio_ex(uint16 mid)
     /* [<][>][^][v][top][bottom][index][help] */
  96 {
  97         struct aio_extra *p;
  98 
  99         for( p = aio_list_head; p; p = p->next) {
 100                 if (mid == p->req->mid) {
 101                         return p;
 102                 }
 103         }
 104         return NULL;
 105 }
 106 
 107 /****************************************************************************
 108  We can have these many aio buffers in flight.
 109 *****************************************************************************/
 110 
 111 /****************************************************************************
 112  Set up an aio request from a SMBreadX call.
 113 *****************************************************************************/
 114 
 115 bool schedule_aio_read_and_X(connection_struct *conn,
     /* [<][>][^][v][top][bottom][index][help] */
 116                              struct smb_request *req,
 117                              files_struct *fsp, SMB_OFF_T startpos,
 118                              size_t smb_maxcnt)
 119 {
 120         struct aio_extra *aio_ex;
 121         SMB_STRUCT_AIOCB *a;
 122         size_t bufsize;
 123         size_t min_aio_read_size = lp_aio_read_size(SNUM(conn));
 124         int ret;
 125 
 126         if (fsp->base_fsp != NULL) {
 127                 /* No AIO on streams yet */
 128                 DEBUG(10, ("AIO on streams not yet supported\n"));
 129                 return false;
 130         }
 131 
 132         if ((!min_aio_read_size || (smb_maxcnt < min_aio_read_size))
 133             && !SMB_VFS_AIO_FORCE(fsp)) {
 134                 /* Too small a read for aio request. */
 135                 DEBUG(10,("schedule_aio_read_and_X: read size (%u) too small "
 136                           "for minimum aio_read of %u\n",
 137                           (unsigned int)smb_maxcnt,
 138                           (unsigned int)min_aio_read_size ));
 139                 return False;
 140         }
 141 
 142         /* Only do this on non-chained and non-chaining reads not using the
 143          * write cache. */
 144         if (req_is_in_chain(req) || (lp_write_cache_size(SNUM(conn)) != 0)) {
 145                 return False;
 146         }
 147 
 148         if (outstanding_aio_calls >= aio_pending_size) {
 149                 DEBUG(10,("schedule_aio_read_and_X: Already have %d aio "
 150                           "activities outstanding.\n",
 151                           outstanding_aio_calls ));
 152                 return False;
 153         }
 154 
 155         /* The following is safe from integer wrap as we've already checked
 156            smb_maxcnt is 128k or less. Wct is 12 for read replies */
 157 
 158         bufsize = smb_size + 12 * 2 + smb_maxcnt;
 159 
 160         if ((aio_ex = create_aio_extra(fsp, bufsize)) == NULL) {
 161                 DEBUG(10,("schedule_aio_read_and_X: malloc fail.\n"));
 162                 return False;
 163         }
 164         aio_ex->handle_completion = handle_aio_read_complete;
 165 
 166         construct_reply_common_req(req, aio_ex->outbuf);
 167         srv_set_message(aio_ex->outbuf, 12, 0, True);
 168         SCVAL(aio_ex->outbuf,smb_vwv0,0xFF); /* Never a chained reply. */
 169 
 170         a = &aio_ex->acb;
 171 
 172         /* Now set up the aio record for the read call. */
 173 
 174         a->aio_fildes = fsp->fh->fd;
 175         a->aio_buf = smb_buf(aio_ex->outbuf);
 176         a->aio_nbytes = smb_maxcnt;
 177         a->aio_offset = startpos;
 178         a->aio_sigevent.sigev_notify = SIGEV_SIGNAL;
 179         a->aio_sigevent.sigev_signo  = RT_SIGNAL_AIO;
 180         a->aio_sigevent.sigev_value.sival_int = req->mid;
 181 
 182         ret = SMB_VFS_AIO_READ(fsp, a);
 183         if (ret == -1) {
 184                 DEBUG(0,("schedule_aio_read_and_X: aio_read failed. "
 185                          "Error %s\n", strerror(errno) ));
 186                 TALLOC_FREE(aio_ex);
 187                 return False;
 188         }
 189 
 190         outstanding_aio_calls++;
 191         aio_ex->req = talloc_move(aio_ex, &req);
 192 
 193         DEBUG(10,("schedule_aio_read_and_X: scheduled aio_read for file %s, "
 194                   "offset %.0f, len = %u (mid = %u)\n",
 195                   fsp->fsp_name, (double)startpos, (unsigned int)smb_maxcnt,
 196                   (unsigned int)aio_ex->req->mid ));
 197 
 198         srv_defer_sign_response(aio_ex->req->mid);
 199         return True;
 200 }
 201 
 202 /****************************************************************************
 203  Set up an aio request from a SMBwriteX call.
 204 *****************************************************************************/
 205 
 206 bool schedule_aio_write_and_X(connection_struct *conn,
     /* [<][>][^][v][top][bottom][index][help] */
 207                               struct smb_request *req,
 208                               files_struct *fsp, char *data,
 209                               SMB_OFF_T startpos,
 210                               size_t numtowrite)
 211 {
 212         struct aio_extra *aio_ex;
 213         SMB_STRUCT_AIOCB *a;
 214         size_t bufsize;
 215         bool write_through = BITSETW(req->vwv+7,0);
 216         size_t min_aio_write_size = lp_aio_write_size(SNUM(conn));
 217         int ret;
 218 
 219         if (fsp->base_fsp != NULL) {
 220                 /* No AIO on streams yet */
 221                 DEBUG(10, ("AIO on streams not yet supported\n"));
 222                 return false;
 223         }
 224 
 225         if ((!min_aio_write_size || (numtowrite < min_aio_write_size))
 226             && !SMB_VFS_AIO_FORCE(fsp)) {
 227                 /* Too small a write for aio request. */
 228                 DEBUG(10,("schedule_aio_write_and_X: write size (%u) too "
 229                           "small for minimum aio_write of %u\n",
 230                           (unsigned int)numtowrite,
 231                           (unsigned int)min_aio_write_size ));
 232                 return False;
 233         }
 234 
 235         /* Only do this on non-chained and non-chaining reads not using the
 236          * write cache. */
 237         if (req_is_in_chain(req) || (lp_write_cache_size(SNUM(conn)) != 0)) {
 238                 return False;
 239         }
 240 
 241         if (outstanding_aio_calls >= aio_pending_size) {
 242                 DEBUG(3,("schedule_aio_write_and_X: Already have %d aio "
 243                          "activities outstanding.\n",
 244                           outstanding_aio_calls ));
 245                 DEBUG(10,("schedule_aio_write_and_X: failed to schedule "
 246                           "aio_write for file %s, offset %.0f, len = %u "
 247                           "(mid = %u)\n",
 248                           fsp->fsp_name, (double)startpos,
 249                           (unsigned int)numtowrite,
 250                           (unsigned int)req->mid ));
 251                 return False;
 252         }
 253 
 254         bufsize = smb_size + 6*2;
 255 
 256         if (!(aio_ex = create_aio_extra(fsp, bufsize))) {
 257                 DEBUG(0,("schedule_aio_write_and_X: malloc fail.\n"));
 258                 return False;
 259         }
 260         aio_ex->handle_completion = handle_aio_write_complete;
 261 
 262         construct_reply_common_req(req, aio_ex->outbuf);
 263         srv_set_message(aio_ex->outbuf, 6, 0, True);
 264         SCVAL(aio_ex->outbuf,smb_vwv0,0xFF); /* Never a chained reply. */
 265 
 266         a = &aio_ex->acb;
 267 
 268         /* Now set up the aio record for the write call. */
 269 
 270         a->aio_fildes = fsp->fh->fd;
 271         a->aio_buf = data;
 272         a->aio_nbytes = numtowrite;
 273         a->aio_offset = startpos;
 274         a->aio_sigevent.sigev_notify = SIGEV_SIGNAL;
 275         a->aio_sigevent.sigev_signo  = RT_SIGNAL_AIO;
 276         a->aio_sigevent.sigev_value.sival_int = req->mid;
 277 
 278         ret = SMB_VFS_AIO_WRITE(fsp, a);
 279         if (ret == -1) {
 280                 DEBUG(3,("schedule_aio_wrote_and_X: aio_write failed. "
 281                          "Error %s\n", strerror(errno) ));
 282                 TALLOC_FREE(aio_ex);
 283                 return False;
 284         }
 285 
 286         outstanding_aio_calls++;
 287         aio_ex->req = talloc_move(aio_ex, &req);
 288 
 289         /* This should actually be improved to span the write. */
 290         contend_level2_oplocks_begin(fsp, LEVEL2_CONTEND_WRITE);
 291         contend_level2_oplocks_end(fsp, LEVEL2_CONTEND_WRITE);
 292 
 293         if (!write_through && !lp_syncalways(SNUM(fsp->conn))
 294             && fsp->aio_write_behind) {
 295                 /* Lie to the client and immediately claim we finished the
 296                  * write. */
 297                 SSVAL(aio_ex->outbuf,smb_vwv2,numtowrite);
 298                 SSVAL(aio_ex->outbuf,smb_vwv4,(numtowrite>>16)&1);
 299                 show_msg(aio_ex->outbuf);
 300                 if (!srv_send_smb(smbd_server_fd(),aio_ex->outbuf,
 301                                 IS_CONN_ENCRYPTED(fsp->conn),
 302                                 &aio_ex->req->pcd)) {
 303                         exit_server_cleanly("handle_aio_write: srv_send_smb "
 304                                             "failed.");
 305                 }
 306                 DEBUG(10,("schedule_aio_write_and_X: scheduled aio_write "
 307                           "behind for file %s\n", fsp->fsp_name ));
 308         } else {
 309                 srv_defer_sign_response(aio_ex->req->mid);
 310         }
 311 
 312         DEBUG(10,("schedule_aio_write_and_X: scheduled aio_write for file "
 313                   "%s, offset %.0f, len = %u (mid = %u) "
 314                   "outstanding_aio_calls = %d\n",
 315                   fsp->fsp_name, (double)startpos, (unsigned int)numtowrite,
 316                   (unsigned int)aio_ex->req->mid, outstanding_aio_calls ));
 317 
 318         return True;
 319 }
 320 
 321 
 322 /****************************************************************************
 323  Complete the read and return the data or error back to the client.
 324  Returns errno or zero if all ok.
 325 *****************************************************************************/
 326 
 327 static int handle_aio_read_complete(struct aio_extra *aio_ex, int errcode)
     /* [<][>][^][v][top][bottom][index][help] */
 328 {
 329         int ret = 0;
 330         int outsize;
 331         char *outbuf = aio_ex->outbuf;
 332         char *data = smb_buf(outbuf);
 333         ssize_t nread = SMB_VFS_AIO_RETURN(aio_ex->fsp,&aio_ex->acb);
 334 
 335         if (nread < 0) {
 336                 /* We're relying here on the fact that if the fd is
 337                    closed then the aio will complete and aio_return
 338                    will return an error. Hopefully this is
 339                    true.... JRA. */
 340 
 341                 DEBUG( 3,( "handle_aio_read_complete: file %s nread == %d "
 342                            "Error = %s\n",
 343                            aio_ex->fsp->fsp_name, (int)nread, strerror(errcode) ));
 344 
 345                 ret = errcode;
 346                 ERROR_NT(map_nt_error_from_unix( ret));
 347                 outsize = srv_set_message(outbuf,0,0,true);
 348         } else {
 349                 outsize = srv_set_message(outbuf,12,nread,False);
 350                 SSVAL(outbuf,smb_vwv2,0xFFFF); /* Remaining - must be * -1. */
 351                 SSVAL(outbuf,smb_vwv5,nread);
 352                 SSVAL(outbuf,smb_vwv6,smb_offset(data,outbuf));
 353                 SSVAL(outbuf,smb_vwv7,((nread >> 16) & 1));
 354                 SSVAL(smb_buf(outbuf),-2,nread);
 355 
 356                 aio_ex->fsp->fh->pos = aio_ex->acb.aio_offset + nread;
 357                 aio_ex->fsp->fh->position_information = aio_ex->fsp->fh->pos;
 358 
 359                 DEBUG( 3, ( "handle_aio_read_complete file %s max=%d "
 360                             "nread=%d\n",
 361                             aio_ex->fsp->fsp_name,
 362                             (int)aio_ex->acb.aio_nbytes, (int)nread ) );
 363 
 364         }
 365         smb_setlen(outbuf,outsize - 4);
 366         show_msg(outbuf);
 367         if (!srv_send_smb(smbd_server_fd(),outbuf,
 368                         IS_CONN_ENCRYPTED(aio_ex->fsp->conn), NULL)) {
 369                 exit_server_cleanly("handle_aio_read_complete: srv_send_smb "
 370                                     "failed.");
 371         }
 372 
 373         DEBUG(10,("handle_aio_read_complete: scheduled aio_read completed "
 374                   "for file %s, offset %.0f, len = %u\n",
 375                   aio_ex->fsp->fsp_name, (double)aio_ex->acb.aio_offset,
 376                   (unsigned int)nread ));
 377 
 378         return ret;
 379 }
 380 
 381 /****************************************************************************
 382  Complete the write and return the data or error back to the client.
 383  Returns error code or zero if all ok.
 384 *****************************************************************************/
 385 
 386 static int handle_aio_write_complete(struct aio_extra *aio_ex, int errcode)
     /* [<][>][^][v][top][bottom][index][help] */
 387 {
 388         int ret = 0;
 389         files_struct *fsp = aio_ex->fsp;
 390         char *outbuf = aio_ex->outbuf;
 391         ssize_t numtowrite = aio_ex->acb.aio_nbytes;
 392         ssize_t nwritten = SMB_VFS_AIO_RETURN(fsp,&aio_ex->acb);
 393 
 394         if (fsp->aio_write_behind) {
 395                 if (nwritten != numtowrite) {
 396                         if (nwritten == -1) {
 397                                 DEBUG(5,("handle_aio_write_complete: "
 398                                          "aio_write_behind failed ! File %s "
 399                                          "is corrupt ! Error %s\n",
 400                                          fsp->fsp_name, strerror(errcode) ));
 401                                 ret = errcode;
 402                         } else {
 403                                 DEBUG(0,("handle_aio_write_complete: "
 404                                          "aio_write_behind failed ! File %s "
 405                                          "is corrupt ! Wanted %u bytes but "
 406                                          "only wrote %d\n", fsp->fsp_name,
 407                                          (unsigned int)numtowrite,
 408                                          (int)nwritten ));
 409                                 ret = EIO;
 410                         }
 411                 } else {
 412                         DEBUG(10,("handle_aio_write_complete: "
 413                                   "aio_write_behind completed for file %s\n",
 414                                   fsp->fsp_name ));
 415                 }
 416                 /* TODO: should no return 0 in case of an error !!! */
 417                 return 0;
 418         }
 419 
 420         /* We don't need outsize or set_message here as we've already set the
 421            fixed size length when we set up the aio call. */
 422 
 423         if(nwritten == -1) {
 424                 DEBUG( 3,( "handle_aio_write: file %s wanted %u bytes. "
 425                            "nwritten == %d. Error = %s\n",
 426                            fsp->fsp_name, (unsigned int)numtowrite,
 427                            (int)nwritten, strerror(errno) ));
 428 
 429                 ret = errcode;
 430                 ERROR_NT(map_nt_error_from_unix(ret));
 431                 srv_set_message(outbuf,0,0,true);
 432         } else {
 433                 bool write_through = BITSETW(aio_ex->req->vwv+7,0);
 434                 NTSTATUS status;
 435 
 436                 SSVAL(outbuf,smb_vwv2,nwritten);
 437                 SSVAL(outbuf,smb_vwv4,(nwritten>>16)&1);
 438                 if (nwritten < (ssize_t)numtowrite) {
 439                         SCVAL(outbuf,smb_rcls,ERRHRD);
 440                         SSVAL(outbuf,smb_err,ERRdiskfull);
 441                 }
 442 
 443                 DEBUG(3,("handle_aio_write: fnum=%d num=%d wrote=%d\n",
 444                          fsp->fnum, (int)numtowrite, (int)nwritten));
 445                 status = sync_file(fsp->conn,fsp, write_through);
 446                 if (!NT_STATUS_IS_OK(status)) {
 447                         ret = errno;
 448                         ERROR_BOTH(map_nt_error_from_unix(ret),
 449                                    ERRHRD, ERRdiskfull);
 450                         srv_set_message(outbuf,0,0,true);
 451                         DEBUG(5,("handle_aio_write: sync_file for %s returned %s\n",
 452                                 fsp->fsp_name, nt_errstr(status) ));
 453                 }
 454 
 455                 aio_ex->fsp->fh->pos = aio_ex->acb.aio_offset + nwritten;
 456         }
 457 
 458         show_msg(outbuf);
 459         if (!srv_send_smb(smbd_server_fd(),outbuf,IS_CONN_ENCRYPTED(fsp->conn),
 460                           NULL)) {
 461                 exit_server_cleanly("handle_aio_write: srv_send_smb failed.");
 462         }
 463 
 464         DEBUG(10,("handle_aio_write_complete: scheduled aio_write completed "
 465                   "for file %s, offset %.0f, requested %u, written = %u\n",
 466                   fsp->fsp_name, (double)aio_ex->acb.aio_offset,
 467                   (unsigned int)numtowrite, (unsigned int)nwritten ));
 468 
 469         return ret;
 470 }
 471 
 472 /****************************************************************************
 473  Handle any aio completion. Returns True if finished (and sets *perr if err
 474  was non-zero), False if not.
 475 *****************************************************************************/
 476 
 477 static bool handle_aio_completed(struct aio_extra *aio_ex, int *perr)
     /* [<][>][^][v][top][bottom][index][help] */
 478 {
 479         int err;
 480 
 481         if(!aio_ex) {
 482                 DEBUG(3, ("handle_aio_completed: Non-existing aio_ex passed\n"));
 483                 return false;
 484         }
 485 
 486         /* Ensure the operation has really completed. */
 487         err = SMB_VFS_AIO_ERROR(aio_ex->fsp, &aio_ex->acb);
 488         if (err == EINPROGRESS) {
 489                 DEBUG(10,( "handle_aio_completed: operation mid %u still in "
 490                            "process for file %s\n",
 491                            aio_ex->req->mid, aio_ex->fsp->fsp_name ));
 492                 return False;
 493         } else if (err == ECANCELED) {
 494                 /* If error is ECANCELED then don't return anything to the
 495                  * client. */
 496                 DEBUG(10,( "handle_aio_completed: operation mid %u"
 497                            " canceled\n", aio_ex->req->mid));
 498                 srv_cancel_sign_response(aio_ex->req->mid, false);
 499                 return True;
 500         }
 501 
 502         err = aio_ex->handle_completion(aio_ex, err);
 503         if (err) {
 504                 *perr = err; /* Only save non-zero errors. */
 505         }
 506 
 507         return True;
 508 }
 509 
 510 /****************************************************************************
 511  Handle any aio completion inline.
 512 *****************************************************************************/
 513 
 514 void smbd_aio_complete_mid(unsigned int mid)
     /* [<][>][^][v][top][bottom][index][help] */
 515 {
 516         files_struct *fsp = NULL;
 517         struct aio_extra *aio_ex = find_aio_ex(mid);
 518         int ret = 0;
 519 
 520         outstanding_aio_calls--;
 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                 srv_cancel_sign_response(mid, false);
 528                 return;
 529         }
 530 
 531         fsp = aio_ex->fsp;
 532         if (fsp == NULL) {
 533                 /* file was closed whilst I/O was outstanding. Just
 534                  * ignore. */
 535                 DEBUG( 3,( "smbd_aio_complete_mid: file closed whilst "
 536                            "aio outstanding (mid[%u]).\n", mid));
 537                 srv_cancel_sign_response(mid, false);
 538                 return;
 539         }
 540 
 541         if (!handle_aio_completed(aio_ex, &ret)) {
 542                 return;
 543         }
 544 
 545         TALLOC_FREE(aio_ex);
 546 }
 547 
 548 static void smbd_aio_signal_handler(struct tevent_context *ev_ctx,
     /* [<][>][^][v][top][bottom][index][help] */
 549                                     struct tevent_signal *se,
 550                                     int signum, int count,
 551                                     void *_info, void *private_data)
 552 {
 553         siginfo_t *info = (siginfo_t *)_info;
 554         unsigned int mid = (unsigned int)info->si_value.sival_int;
 555 
 556         smbd_aio_complete_mid(mid);
 557 }
 558 
 559 /****************************************************************************
 560  We're doing write behind and the client closed the file. Wait up to 30
 561  seconds (my arbitrary choice) for the aio to complete. Return 0 if all writes
 562  completed, errno to return if not.
 563 *****************************************************************************/
 564 
 565 #define SMB_TIME_FOR_AIO_COMPLETE_WAIT 29
 566 
 567 int wait_for_aio_completion(files_struct *fsp)
     /* [<][>][^][v][top][bottom][index][help] */
 568 {
 569         struct aio_extra *aio_ex;
 570         const SMB_STRUCT_AIOCB **aiocb_list;
 571         int aio_completion_count = 0;
 572         time_t start_time = time(NULL);
 573         int seconds_left;
 574 
 575         for (seconds_left = SMB_TIME_FOR_AIO_COMPLETE_WAIT;
 576              seconds_left >= 0;) {
 577                 int err = 0;
 578                 int i;
 579                 struct timespec ts;
 580 
 581                 aio_completion_count = 0;
 582                 for( aio_ex = aio_list_head; aio_ex; aio_ex = aio_ex->next) {
 583                         if (aio_ex->fsp == fsp) {
 584                                 aio_completion_count++;
 585                         }
 586                 }
 587 
 588                 if (!aio_completion_count) {
 589                         return 0;
 590                 }
 591 
 592                 DEBUG(3,("wait_for_aio_completion: waiting for %d aio events "
 593                          "to complete.\n", aio_completion_count ));
 594 
 595                 aiocb_list = SMB_MALLOC_ARRAY(const SMB_STRUCT_AIOCB *,
 596                                               aio_completion_count);
 597                 if (!aiocb_list) {
 598                         return ENOMEM;
 599                 }
 600 
 601                 for( i = 0, aio_ex = aio_list_head;
 602                      aio_ex;
 603                      aio_ex = aio_ex->next) {
 604                         if (aio_ex->fsp == fsp) {
 605                                 aiocb_list[i++] = &aio_ex->acb;
 606                         }
 607                 }
 608 
 609                 /* Now wait up to seconds_left for completion. */
 610                 ts.tv_sec = seconds_left;
 611                 ts.tv_nsec = 0;
 612 
 613                 DEBUG(10,("wait_for_aio_completion: %d events, doing a wait "
 614                           "of %d seconds.\n",
 615                           aio_completion_count, seconds_left ));
 616 
 617                 err = SMB_VFS_AIO_SUSPEND(fsp, aiocb_list,
 618                                           aio_completion_count, &ts);
 619 
 620                 DEBUG(10,("wait_for_aio_completion: returned err = %d, "
 621                           "errno = %s\n", err, strerror(errno) ));
 622 
 623                 if (err == -1 && errno == EAGAIN) {
 624                         DEBUG(0,("wait_for_aio_completion: aio_suspend timed "
 625                                  "out waiting for %d events after a wait of "
 626                                  "%d seconds\n", aio_completion_count,
 627                                  seconds_left));
 628                         /* Timeout. */
 629                         cancel_aio_by_fsp(fsp);
 630                         SAFE_FREE(aiocb_list);
 631                         return EIO;
 632                 }
 633 
 634                 /* One or more events might have completed - process them if
 635                  * so. */
 636                 for( i = 0; i < aio_completion_count; i++) {
 637                         uint16 mid = aiocb_list[i]->aio_sigevent.sigev_value.sival_int;
 638 
 639                         aio_ex = find_aio_ex(mid);
 640 
 641                         if (!aio_ex) {
 642                                 DEBUG(0, ("wait_for_aio_completion: mid %u "
 643                                           "doesn't match an aio record\n",
 644                                           (unsigned int)mid ));
 645                                 continue;
 646                         }
 647 
 648                         if (!handle_aio_completed(aio_ex, &err)) {
 649                                 continue;
 650                         }
 651                         TALLOC_FREE(aio_ex);
 652                 }
 653 
 654                 SAFE_FREE(aiocb_list);
 655                 seconds_left = SMB_TIME_FOR_AIO_COMPLETE_WAIT
 656                         - (time(NULL) - start_time);
 657         }
 658 
 659         /* We timed out - we don't know why. Return ret if already an error,
 660          * else EIO. */
 661         DEBUG(10,("wait_for_aio_completion: aio_suspend timed out waiting "
 662                   "for %d events\n",
 663                   aio_completion_count));
 664 
 665         return EIO;
 666 }
 667 
 668 /****************************************************************************
 669  Cancel any outstanding aio requests. The client doesn't care about the reply.
 670 *****************************************************************************/
 671 
 672 void cancel_aio_by_fsp(files_struct *fsp)
     /* [<][>][^][v][top][bottom][index][help] */
 673 {
 674         struct aio_extra *aio_ex;
 675 
 676         for( aio_ex = aio_list_head; aio_ex; aio_ex = aio_ex->next) {
 677                 if (aio_ex->fsp == fsp) {
 678                         /* Don't delete the aio_extra record as we may have
 679                            completed and don't yet know it. Just do the
 680                            aio_cancel call and return. */
 681                         SMB_VFS_AIO_CANCEL(fsp, &aio_ex->acb);
 682                         aio_ex->fsp = NULL; /* fsp will be closed when we
 683                                              * return. */
 684                 }
 685         }
 686 }
 687 
 688 /****************************************************************************
 689  Initialize the signal handler for aio read/write.
 690 *****************************************************************************/
 691 
 692 void initialize_async_io_handler(void)
     /* [<][>][^][v][top][bottom][index][help] */
 693 {
 694         aio_signal_event = tevent_add_signal(smbd_event_context(),
 695                                              smbd_event_context(),
 696                                              RT_SIGNAL_AIO, SA_SIGINFO,
 697                                              smbd_aio_signal_handler,
 698                                              NULL);
 699         if (!aio_signal_event) {
 700                 exit_server("Failed to setup RT_SIGNAL_AIO handler");
 701         }
 702 
 703         /* tevent supports 100 signal with SA_SIGINFO */
 704         aio_pending_size = 100;
 705 }
 706 
 707 #else
 708 void initialize_async_io_handler(void)
     /* [<][>][^][v][top][bottom][index][help] */
 709 {
 710 }
 711 
 712 bool schedule_aio_read_and_X(connection_struct *conn,
     /* [<][>][^][v][top][bottom][index][help] */
 713                              struct smb_request *req,
 714                              files_struct *fsp, SMB_OFF_T startpos,
 715                              size_t smb_maxcnt)
 716 {
 717         return False;
 718 }
 719 
 720 bool schedule_aio_write_and_X(connection_struct *conn,
     /* [<][>][^][v][top][bottom][index][help] */
 721                               struct smb_request *req,
 722                               files_struct *fsp, char *data,
 723                               SMB_OFF_T startpos,
 724                               size_t numtowrite)
 725 {
 726         return False;
 727 }
 728 
 729 void cancel_aio_by_fsp(files_struct *fsp)
     /* [<][>][^][v][top][bottom][index][help] */
 730 {
 731 }
 732 
 733 int wait_for_aio_completion(files_struct *fsp)
     /* [<][>][^][v][top][bottom][index][help] */
 734 {
 735         return ENOSYS;
 736 }
 737 
 738 void smbd_aio_complete_mid(unsigned int mid);
 739 
 740 #endif

/* [<][>][^][v][top][bottom][index][help] */