smbd: some write time fixes
[tprouty/samba.git] / 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 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         become_root();
272         if (SMB_VFS_AIO_READ(fsp,a) == -1) {
273                 DEBUG(0,("schedule_aio_read_and_X: aio_read failed. "
274                          "Error %s\n", strerror(errno) ));
275                 delete_aio_ex(aio_ex);
276                 unbecome_root();
277                 return False;
278         }
279         unbecome_root();
280
281         DEBUG(10,("schedule_aio_read_and_X: scheduled aio_read for file %s, "
282                   "offset %.0f, len = %u (mid = %u)\n",
283                   fsp->fsp_name, (double)startpos, (unsigned int)smb_maxcnt,
284                   (unsigned int)aio_ex->mid ));
285
286         srv_defer_sign_response(aio_ex->mid);
287         outstanding_aio_calls++;
288         return True;
289 }
290
291 /****************************************************************************
292  Set up an aio request from a SMBwriteX call.
293 *****************************************************************************/
294
295 bool schedule_aio_write_and_X(connection_struct *conn,
296                               struct smb_request *req,
297                               files_struct *fsp, char *data,
298                               SMB_OFF_T startpos,
299                               size_t numtowrite)
300 {
301         struct aio_extra *aio_ex;
302         SMB_STRUCT_AIOCB *a;
303         size_t inbufsize, outbufsize;
304         bool write_through = BITSETW(req->inbuf+smb_vwv7,0);
305         size_t min_aio_write_size = lp_aio_write_size(SNUM(conn));
306
307         if (fsp->base_fsp != NULL) {
308                 /* No AIO on streams yet */
309                 DEBUG(10, ("AIO on streams not yet supported\n"));
310                 return false;
311         }
312
313         if ((!min_aio_write_size || (numtowrite < min_aio_write_size))
314             && !SMB_VFS_AIO_FORCE(fsp)) {
315                 /* Too small a write for aio request. */
316                 DEBUG(10,("schedule_aio_write_and_X: write size (%u) too "
317                           "small for minimum aio_write of %u\n",
318                           (unsigned int)numtowrite,
319                           (unsigned int)min_aio_write_size ));
320                 return False;
321         }
322
323         /* Only do this on non-chained and non-chaining reads not using the
324          * write cache. */
325         if (chain_size !=0 || (CVAL(req->inbuf,smb_vwv0) != 0xFF)
326             || (lp_write_cache_size(SNUM(conn)) != 0) ) {
327                 return False;
328         }
329
330         if (outstanding_aio_calls >= aio_pending_size) {
331                 DEBUG(3,("schedule_aio_write_and_X: Already have %d aio "
332                          "activities outstanding.\n",
333                           outstanding_aio_calls ));
334                 DEBUG(10,("schedule_aio_write_and_X: failed to schedule "
335                           "aio_write for file %s, offset %.0f, len = %u "
336                           "(mid = %u)\n",
337                           fsp->fsp_name, (double)startpos,
338                           (unsigned int)numtowrite,
339                           (unsigned int)req->mid ));
340                 return False;
341         }
342
343         inbufsize =  smb_len(req->inbuf) + 4;
344         reply_outbuf(req, 6, 0);
345         outbufsize = smb_len(req->outbuf) + 4;
346         if (!(aio_ex = create_aio_ex_write(fsp, inbufsize, outbufsize,
347                                            req->mid))) {
348                 DEBUG(0,("schedule_aio_write_and_X: malloc fail.\n"));
349                 return False;
350         }
351
352         /* Copy the SMB header already setup in outbuf. */
353         memcpy(aio_ex->inbuf, req->inbuf, inbufsize);
354
355         /* Copy the SMB header already setup in outbuf. */
356         memcpy(aio_ex->outbuf, req->outbuf, outbufsize);
357         TALLOC_FREE(req->outbuf);
358         SCVAL(aio_ex->outbuf,smb_vwv0,0xFF); /* Never a chained reply. */
359
360         a = &aio_ex->acb;
361
362         /* Now set up the aio record for the write call. */
363         
364         a->aio_fildes = fsp->fh->fd;
365         a->aio_buf = aio_ex->inbuf + (PTR_DIFF(data, req->inbuf));
366         a->aio_nbytes = numtowrite;
367         a->aio_offset = startpos;
368         a->aio_sigevent.sigev_notify = SIGEV_SIGNAL;
369         a->aio_sigevent.sigev_signo  = RT_SIGNAL_AIO;
370         a->aio_sigevent.sigev_value.sival_int = aio_ex->mid;
371
372         become_root();
373         if (SMB_VFS_AIO_WRITE(fsp,a) == -1) {
374                 DEBUG(3,("schedule_aio_wrote_and_X: aio_write failed. "
375                          "Error %s\n", strerror(errno) ));
376                 delete_aio_ex(aio_ex);
377                 unbecome_root();
378                 return False;
379         }
380         unbecome_root();
381         
382         release_level_2_oplocks_on_change(fsp);
383
384         if (!write_through && !lp_syncalways(SNUM(fsp->conn))
385             && fsp->aio_write_behind) {
386                 /* Lie to the client and immediately claim we finished the
387                  * write. */
388                 SSVAL(aio_ex->outbuf,smb_vwv2,numtowrite);
389                 SSVAL(aio_ex->outbuf,smb_vwv4,(numtowrite>>16)&1);
390                 show_msg(aio_ex->outbuf);
391                 if (!srv_send_smb(smbd_server_fd(),aio_ex->outbuf,
392                                 IS_CONN_ENCRYPTED(fsp->conn))) {
393                         exit_server_cleanly("handle_aio_write: srv_send_smb "
394                                             "failed.");
395                 }
396                 DEBUG(10,("schedule_aio_write_and_X: scheduled aio_write "
397                           "behind for file %s\n", fsp->fsp_name ));
398         } else {
399                 srv_defer_sign_response(aio_ex->mid);
400         }
401         outstanding_aio_calls++;
402
403         DEBUG(10,("schedule_aio_write_and_X: scheduled aio_write for file "
404                   "%s, offset %.0f, len = %u (mid = %u) "
405                   "outstanding_aio_calls = %d\n",
406                   fsp->fsp_name, (double)startpos, (unsigned int)numtowrite,
407                   (unsigned int)aio_ex->mid, outstanding_aio_calls ));
408
409         return True;
410 }
411
412
413 /****************************************************************************
414  Complete the read and return the data or error back to the client.
415  Returns errno or zero if all ok.
416 *****************************************************************************/
417
418 static int handle_aio_read_complete(struct aio_extra *aio_ex)
419 {
420         int ret = 0;
421         int outsize;
422         char *outbuf = aio_ex->outbuf;
423         char *data = smb_buf(outbuf);
424         ssize_t nread = SMB_VFS_AIO_RETURN(aio_ex->fsp,&aio_ex->acb);
425
426         if (nread < 0) {
427                 /* We're relying here on the fact that if the fd is
428                    closed then the aio will complete and aio_return
429                    will return an error. Hopefully this is
430                    true.... JRA. */
431
432                 /* If errno is ECANCELED then don't return anything to the
433                  * client. */
434                 if (errno == ECANCELED) {
435                         srv_cancel_sign_response(aio_ex->mid);
436                         return 0;
437                 }
438
439                 DEBUG( 3,( "handle_aio_read_complete: file %s nread == -1. "
440                            "Error = %s\n",
441                            aio_ex->fsp->fsp_name, strerror(errno) ));
442
443                 ret = errno;
444                 ERROR_NT(map_nt_error_from_unix(ret));
445                 outsize = srv_set_message(outbuf,0,0,true);
446         } else {
447                 outsize = srv_set_message(outbuf,12,nread,False);
448                 SSVAL(outbuf,smb_vwv2,0xFFFF); /* Remaining - must be * -1. */
449                 SSVAL(outbuf,smb_vwv5,nread);
450                 SSVAL(outbuf,smb_vwv6,smb_offset(data,outbuf));
451                 SSVAL(outbuf,smb_vwv7,((nread >> 16) & 1));
452                 SSVAL(smb_buf(outbuf),-2,nread);
453
454                 aio_ex->fsp->fh->pos = aio_ex->acb.aio_offset + nread;
455                 aio_ex->fsp->fh->position_information = aio_ex->fsp->fh->pos;
456
457                 DEBUG( 3, ( "handle_aio_read_complete file %s max=%d "
458                             "nread=%d\n",
459                             aio_ex->fsp->fsp_name,
460                             (int)aio_ex->acb.aio_nbytes, (int)nread ) );
461
462         }
463         smb_setlen(outbuf,outsize - 4);
464         show_msg(outbuf);
465         if (!srv_send_smb(smbd_server_fd(),outbuf,
466                         IS_CONN_ENCRYPTED(aio_ex->fsp->conn))) {
467                 exit_server_cleanly("handle_aio_read_complete: srv_send_smb "
468                                     "failed.");
469         }
470
471         DEBUG(10,("handle_aio_read_complete: scheduled aio_read completed "
472                   "for file %s, offset %.0f, len = %u\n",
473                   aio_ex->fsp->fsp_name, (double)aio_ex->acb.aio_offset,
474                   (unsigned int)nread ));
475
476         return ret;
477 }
478
479 /****************************************************************************
480  Complete the write and return the data or error back to the client.
481  Returns errno or zero if all ok.
482 *****************************************************************************/
483
484 static int handle_aio_write_complete(struct aio_extra *aio_ex)
485 {
486         int ret = 0;
487         files_struct *fsp = aio_ex->fsp;
488         char *outbuf = aio_ex->outbuf;
489         ssize_t numtowrite = aio_ex->acb.aio_nbytes;
490         ssize_t nwritten = SMB_VFS_AIO_RETURN(fsp,&aio_ex->acb);
491
492         if (fsp->aio_write_behind) {
493                 if (nwritten != numtowrite) {
494                         if (nwritten == -1) {
495                                 DEBUG(5,("handle_aio_write_complete: "
496                                          "aio_write_behind failed ! File %s "
497                                          "is corrupt ! Error %s\n",
498                                          fsp->fsp_name, strerror(errno) ));
499                                 ret = errno;
500                         } else {
501                                 DEBUG(0,("handle_aio_write_complete: "
502                                          "aio_write_behind failed ! File %s "
503                                          "is corrupt ! Wanted %u bytes but "
504                                          "only wrote %d\n", fsp->fsp_name,
505                                          (unsigned int)numtowrite,
506                                          (int)nwritten ));
507                                 ret = EIO;
508                         }
509                 } else {
510                         DEBUG(10,("handle_aio_write_complete: "
511                                   "aio_write_behind completed for file %s\n",
512                                   fsp->fsp_name ));
513                 }
514                 return 0;
515         }
516
517         /* We don't need outsize or set_message here as we've already set the
518            fixed size length when we set up the aio call. */
519
520         if(nwritten == -1) {
521                 DEBUG( 3,( "handle_aio_write: file %s wanted %u bytes. "
522                            "nwritten == %d. Error = %s\n",
523                            fsp->fsp_name, (unsigned int)numtowrite,
524                            (int)nwritten, strerror(errno) ));
525
526                 /* If errno is ECANCELED then don't return anything to the
527                  * client. */
528                 if (errno == ECANCELED) {
529                         srv_cancel_sign_response(aio_ex->mid);
530                         return 0;
531                 }
532
533                 ret = errno;
534                 ERROR_BOTH(map_nt_error_from_unix(ret), ERRHRD, ERRdiskfull);
535                 srv_set_message(outbuf,0,0,true);
536         } else {
537                 bool write_through = BITSETW(aio_ex->inbuf+smb_vwv7,0);
538                 NTSTATUS status;
539
540                 SSVAL(outbuf,smb_vwv2,nwritten);
541                 SSVAL(outbuf,smb_vwv4,(nwritten>>16)&1);
542                 if (nwritten < (ssize_t)numtowrite) {
543                         SCVAL(outbuf,smb_rcls,ERRHRD);
544                         SSVAL(outbuf,smb_err,ERRdiskfull);
545                 }
546
547                 DEBUG(3,("handle_aio_write: fnum=%d num=%d wrote=%d\n",
548                          fsp->fnum, (int)numtowrite, (int)nwritten));
549                 status = sync_file(fsp->conn,fsp, write_through);
550                 if (!NT_STATUS_IS_OK(status)) {
551                         ret = errno;
552                         ERROR_BOTH(map_nt_error_from_unix(ret),
553                                    ERRHRD, ERRdiskfull);
554                         srv_set_message(outbuf,0,0,true);
555                         DEBUG(5,("handle_aio_write: sync_file for %s returned %s\n",
556                                 fsp->fsp_name, nt_errstr(status) ));
557                 }
558
559                 aio_ex->fsp->fh->pos = aio_ex->acb.aio_offset + nwritten;
560         }
561
562         show_msg(outbuf);
563         if (!srv_send_smb(smbd_server_fd(),outbuf,IS_CONN_ENCRYPTED(fsp->conn))) {
564                 exit_server_cleanly("handle_aio_write: srv_send_smb failed.");
565         }
566
567         DEBUG(10,("handle_aio_write_complete: scheduled aio_write completed "
568                   "for file %s, offset %.0f, requested %u, written = %u\n",
569                   fsp->fsp_name, (double)aio_ex->acb.aio_offset,
570                   (unsigned int)numtowrite, (unsigned int)nwritten ));
571
572         return ret;
573 }
574
575 /****************************************************************************
576  Handle any aio completion. Returns True if finished (and sets *perr if err
577  was non-zero), False if not.
578 *****************************************************************************/
579
580 static bool handle_aio_completed(struct aio_extra *aio_ex, int *perr)
581 {
582         int err;
583
584         /* Ensure the operation has really completed. */
585         if (SMB_VFS_AIO_ERROR(aio_ex->fsp, &aio_ex->acb) == EINPROGRESS) {
586                 DEBUG(10,( "handle_aio_completed: operation mid %u still in "
587                            "process for file %s\n",
588                            aio_ex->mid, aio_ex->fsp->fsp_name ));
589                 return False;
590         }
591
592         if (aio_ex->read_req) {
593                 err = handle_aio_read_complete(aio_ex);
594         } else {
595                 err = handle_aio_write_complete(aio_ex);
596         }
597
598         if (err) {
599                 *perr = err; /* Only save non-zero errors. */
600         }
601
602         return True;
603 }
604
605 /****************************************************************************
606  Handle any aio completion inline.
607  Returns non-zero errno if fail or zero if all ok.
608 *****************************************************************************/
609
610 int process_aio_queue(void)
611 {
612         int i;
613         int ret = 0;
614
615         BlockSignals(True, RT_SIGNAL_AIO);
616
617         DEBUG(10,("process_aio_queue: signals_received = %d\n",
618                   (int)signals_received));
619         DEBUG(10,("process_aio_queue: outstanding_aio_calls = %d\n",
620                   outstanding_aio_calls));
621
622         if (!signals_received) {
623                 BlockSignals(False, RT_SIGNAL_AIO);
624                 return 0;
625         }
626
627         /* Drain all the complete aio_reads. */
628         for (i = 0; i < signals_received; i++) {
629                 uint16 mid = aio_pending_array[i];
630                 files_struct *fsp = NULL;
631                 struct aio_extra *aio_ex = find_aio_ex(mid);
632
633                 if (!aio_ex) {
634                         DEBUG(3,("process_aio_queue: Can't find record to "
635                                  "match mid %u.\n", (unsigned int)mid));
636                         srv_cancel_sign_response(mid);
637                         continue;
638                 }
639
640                 fsp = aio_ex->fsp;
641                 if (fsp == NULL) {
642                         /* file was closed whilst I/O was outstanding. Just
643                          * ignore. */
644                         DEBUG( 3,( "process_aio_queue: file closed whilst "
645                                    "aio outstanding.\n"));
646                         srv_cancel_sign_response(mid);
647                         continue;
648                 }
649
650                 if (!handle_aio_completed(aio_ex, &ret)) {
651                         continue;
652                 }
653
654                 delete_aio_ex(aio_ex);
655         }
656
657         outstanding_aio_calls -= signals_received;
658         signals_received = 0;
659         BlockSignals(False, RT_SIGNAL_AIO);
660         return ret;
661 }
662
663 /****************************************************************************
664  We're doing write behind and the client closed the file. Wait up to 30
665  seconds (my arbitrary choice) for the aio to complete. Return 0 if all writes
666  completed, errno to return if not.
667 *****************************************************************************/
668
669 #define SMB_TIME_FOR_AIO_COMPLETE_WAIT 29
670
671 int wait_for_aio_completion(files_struct *fsp)
672 {
673         struct aio_extra *aio_ex;
674         const SMB_STRUCT_AIOCB **aiocb_list;
675         int aio_completion_count = 0;
676         time_t start_time = time(NULL);
677         int seconds_left;
678
679         for (seconds_left = SMB_TIME_FOR_AIO_COMPLETE_WAIT;
680              seconds_left >= 0;) {
681                 int err = 0;
682                 int i;
683                 struct timespec ts;
684
685                 aio_completion_count = 0;
686                 for( aio_ex = aio_list_head; aio_ex; aio_ex = aio_ex->next) {
687                         if (aio_ex->fsp == fsp) {
688                                 aio_completion_count++;
689                         }
690                 }
691
692                 if (!aio_completion_count) {
693                         return 0;
694                 }
695
696                 DEBUG(3,("wait_for_aio_completion: waiting for %d aio events "
697                          "to complete.\n", aio_completion_count ));
698
699                 aiocb_list = SMB_MALLOC_ARRAY(const SMB_STRUCT_AIOCB *,
700                                               aio_completion_count);
701                 if (!aiocb_list) {
702                         return ENOMEM;
703                 }
704
705                 for( i = 0, aio_ex = aio_list_head;
706                      aio_ex;
707                      aio_ex = aio_ex->next) {
708                         if (aio_ex->fsp == fsp) {
709                                 aiocb_list[i++] = &aio_ex->acb;
710                         }
711                 }
712
713                 /* Now wait up to seconds_left for completion. */
714                 ts.tv_sec = seconds_left;
715                 ts.tv_nsec = 0;
716
717                 DEBUG(10,("wait_for_aio_completion: %d events, doing a wait "
718                           "of %d seconds.\n",
719                           aio_completion_count, seconds_left ));
720
721                 err = SMB_VFS_AIO_SUSPEND(fsp, aiocb_list,
722                                           aio_completion_count, &ts);
723
724                 DEBUG(10,("wait_for_aio_completion: returned err = %d, "
725                           "errno = %s\n", err, strerror(errno) ));
726                 
727                 if (err == -1 && errno == EAGAIN) {
728                         DEBUG(0,("wait_for_aio_completion: aio_suspend timed "
729                                  "out waiting for %d events after a wait of "
730                                  "%d seconds\n", aio_completion_count,
731                                  seconds_left));
732                         /* Timeout. */
733                         cancel_aio_by_fsp(fsp);
734                         SAFE_FREE(aiocb_list);
735                         return EIO;
736                 }
737
738                 /* One or more events might have completed - process them if
739                  * so. */
740                 for( i = 0; i < aio_completion_count; i++) {
741                         uint16 mid = aiocb_list[i]->aio_sigevent.sigev_value.sival_int;
742
743                         aio_ex = find_aio_ex(mid);
744
745                         if (!aio_ex) {
746                                 DEBUG(0, ("wait_for_aio_completion: mid %u "
747                                           "doesn't match an aio record\n",
748                                           (unsigned int)mid ));
749                                 continue;
750                         }
751
752                         if (!handle_aio_completed(aio_ex, &err)) {
753                                 continue;
754                         }
755                         delete_aio_ex(aio_ex);
756                 }
757
758                 SAFE_FREE(aiocb_list);
759                 seconds_left = SMB_TIME_FOR_AIO_COMPLETE_WAIT
760                         - (time(NULL) - start_time);
761         }
762
763         /* We timed out - we don't know why. Return ret if already an error,
764          * else EIO. */
765         DEBUG(10,("wait_for_aio_completion: aio_suspend timed out waiting "
766                   "for %d events\n",
767                   aio_completion_count));
768
769         return EIO;
770 }
771
772 /****************************************************************************
773  Cancel any outstanding aio requests. The client doesn't care about the reply.
774 *****************************************************************************/
775
776 void cancel_aio_by_fsp(files_struct *fsp)
777 {
778         struct aio_extra *aio_ex;
779
780         for( aio_ex = aio_list_head; aio_ex; aio_ex = aio_ex->next) {
781                 if (aio_ex->fsp == fsp) {
782                         /* Don't delete the aio_extra record as we may have
783                            completed and don't yet know it. Just do the
784                            aio_cancel call and return. */
785                         SMB_VFS_AIO_CANCEL(fsp, &aio_ex->acb);
786                         aio_ex->fsp = NULL; /* fsp will be closed when we
787                                              * return. */
788                 }
789         }
790 }
791
792 #else
793 bool aio_finished(void)
794 {
795         return False;
796 }
797
798 void initialize_async_io_handler(void)
799 {
800 }
801
802 int process_aio_queue(void)
803 {
804         return False;
805 }
806
807 bool schedule_aio_read_and_X(connection_struct *conn,
808                              struct smb_request *req,
809                              files_struct *fsp, SMB_OFF_T startpos,
810                              size_t smb_maxcnt)
811 {
812         return False;
813 }
814
815 bool schedule_aio_write_and_X(connection_struct *conn,
816                               struct smb_request *req,
817                               files_struct *fsp, char *data,
818                               SMB_OFF_T startpos,
819                               size_t numtowrite)
820 {
821         return False;
822 }
823
824 void cancel_aio_by_fsp(files_struct *fsp)
825 {
826 }
827
828 int wait_for_aio_completion(files_struct *fsp)
829 {
830         return ENOSYS;
831 }
832 #endif