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