aio.c revision 331722 
1/*
2 * Copyright (c) 2005 David Xu <davidxu@freebsd.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice unmodified, this list of conditions, and the following
10 *    disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 *
26 * $FreeBSD: stable/11/lib/librt/aio.c 331722 2018-03-29 02:50:57Z eadler $
27 *
28 */
29
30#include <sys/cdefs.h>
31#include <sys/types.h>
32#include <sys/syscall.h>
33#include <sys/aio.h>
34
35#include "namespace.h"
36#include <errno.h>
37#include <stddef.h>
38#include <signal.h>
39#include "sigev_thread.h"
40#include "un-namespace.h"
41
42__weak_reference(__aio_read, _aio_read);
43__weak_reference(__aio_read, aio_read);
44__weak_reference(__aio_write, _aio_write);
45__weak_reference(__aio_write, aio_write);
46__weak_reference(__aio_return, _aio_return);
47__weak_reference(__aio_return, aio_return);
48__weak_reference(__aio_waitcomplete, _aio_waitcomplete);
49__weak_reference(__aio_waitcomplete, aio_waitcomplete);
50__weak_reference(__aio_fsync, _aio_fsync);
51__weak_reference(__aio_fsync, aio_fsync);
52__weak_reference(__lio_listio, lio_listio);
53
54typedef void (*aio_func)(union sigval val, struct aiocb *iocb);
55
56extern int __sys_aio_read(struct aiocb *iocb);
57extern int __sys_aio_write(struct aiocb *iocb);
58extern ssize_t __sys_aio_waitcomplete(struct aiocb **iocbp, struct timespec *timeout);
59extern ssize_t __sys_aio_return(struct aiocb *iocb);
60extern int __sys_aio_error(struct aiocb *iocb);
61extern int __sys_aio_fsync(int op, struct aiocb *iocb);
62extern int __sys_lio_listio(int mode, struct aiocb * const list[], int nent,
63    struct sigevent *sig);
64
65static void
66aio_dispatch(struct sigev_node *sn)
67{
68	aio_func f = sn->sn_func;
69
70	f(sn->sn_value, (struct aiocb *)sn->sn_id);
71}
72
73static int
74aio_sigev_alloc(sigev_id_t id, struct sigevent *sigevent,
75    struct sigev_node **sn, struct sigevent *saved_ev)
76{
77	if (__sigev_check_init()) {
78		/* This might be that thread library is not enabled. */
79		errno = EINVAL;
80		return (-1);
81	}
82
83	*sn = __sigev_alloc(SI_ASYNCIO, sigevent, NULL, 1);
84	if (*sn == NULL) {
85		errno = EAGAIN;
86		return (-1);
87	}
88
89	*saved_ev = *sigevent;
90	(*sn)->sn_id = id;
91	__sigev_get_sigevent(*sn, sigevent, (*sn)->sn_id);
92	(*sn)->sn_dispatch = aio_dispatch;
93
94	__sigev_list_lock();
95	__sigev_register(*sn);
96	__sigev_list_unlock();
97
98	return (0);
99}
100
101static int
102aio_io(struct aiocb *iocb, int (*sysfunc)(struct aiocb *iocb))
103{
104	struct sigev_node *sn;
105	struct sigevent saved_ev;
106	int ret, err;
107
108	if (iocb->aio_sigevent.sigev_notify != SIGEV_THREAD) {
109		ret = sysfunc(iocb);
110		return (ret);
111	}
112
113	ret = aio_sigev_alloc((sigev_id_t)iocb, &iocb->aio_sigevent, &sn,
114			      &saved_ev);
115	if (ret)
116		return (ret);
117	ret = sysfunc(iocb);
118	iocb->aio_sigevent = saved_ev;
119	if (ret != 0) {
120		err = errno;
121		__sigev_list_lock();
122		__sigev_delete_node(sn);
123		__sigev_list_unlock();
124		errno = err;
125	}
126	return (ret);
127}
128
129int
130__aio_read(struct aiocb *iocb)
131{
132
133	return aio_io(iocb, &__sys_aio_read);
134}
135
136int
137__aio_write(struct aiocb *iocb)
138{
139
140	return aio_io(iocb, &__sys_aio_write);
141}
142
143ssize_t
144__aio_waitcomplete(struct aiocb **iocbp, struct timespec *timeout)
145{
146	ssize_t ret;
147	int err;
148
149	ret = __sys_aio_waitcomplete(iocbp, timeout);
150	if (*iocbp) {
151		if ((*iocbp)->aio_sigevent.sigev_notify == SIGEV_THREAD) {
152			err = errno;
153			__sigev_list_lock();
154			__sigev_delete(SI_ASYNCIO, (sigev_id_t)(*iocbp));
155			__sigev_list_unlock();
156			errno = err;
157		}
158	}
159
160	return (ret);
161}
162
163ssize_t
164__aio_return(struct aiocb *iocb)
165{
166
167	if (iocb->aio_sigevent.sigev_notify == SIGEV_THREAD) {
168		if (__sys_aio_error(iocb) == EINPROGRESS) {
169			/*
170			 * Fail with EINVAL to match the semantics of
171			 * __sys_aio_return() for an in-progress
172			 * request.
173			 */
174			errno = EINVAL;
175			return (-1);
176		}
177		__sigev_list_lock();
178		__sigev_delete(SI_ASYNCIO, (sigev_id_t)iocb);
179		__sigev_list_unlock();
180	}
181
182	return __sys_aio_return(iocb);
183}
184
185int
186__aio_fsync(int op, struct aiocb *iocb)
187{
188	struct sigev_node *sn;
189	struct sigevent saved_ev;
190	int ret, err;
191
192	if (iocb->aio_sigevent.sigev_notify != SIGEV_THREAD)
193		return __sys_aio_fsync(op, iocb);
194
195	ret = aio_sigev_alloc((sigev_id_t)iocb, &iocb->aio_sigevent, &sn,
196			      &saved_ev);
197	if (ret)
198		return (ret);
199	ret = __sys_aio_fsync(op, iocb);
200	iocb->aio_sigevent = saved_ev;
201	if (ret != 0) {
202		err = errno;
203		__sigev_list_lock();
204		__sigev_delete_node(sn);
205		__sigev_list_unlock();
206		errno = err;
207	}
208	return (ret);
209}
210
211int
212__lio_listio(int mode, struct aiocb * const list[], int nent,
213    struct sigevent *sig)
214{
215	struct sigev_node *sn;
216	struct sigevent saved_ev;
217	int ret, err;
218
219	if (sig == NULL || sig->sigev_notify != SIGEV_THREAD)
220		return (__sys_lio_listio(mode, list, nent, sig));
221
222	ret = aio_sigev_alloc((sigev_id_t)list, sig, &sn, &saved_ev);
223	if (ret)
224		return (ret);
225	ret = __sys_lio_listio(mode, list, nent, sig);
226	*sig = saved_ev;
227	if (ret != 0) {
228		err = errno;
229		__sigev_list_lock();
230		__sigev_delete_node(sn);
231		__sigev_list_unlock();
232		errno = err;
233	}
234	return (ret);
235}
236