xref: /freebsd/lib/librt/aio.c (revision dd41de95a84d979615a2ef11df6850622bf6184e)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2005 David Xu <davidxu@freebsd.org>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice unmodified, this list of conditions, and the following
12  *    disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  *
28  * $FreeBSD$
29  *
30  */
31 
32 #include <sys/cdefs.h>
33 #include <sys/types.h>
34 #include <sys/syscall.h>
35 #include <sys/aio.h>
36 
37 #include "namespace.h"
38 #include <errno.h>
39 #include <stddef.h>
40 #include <signal.h>
41 #include "sigev_thread.h"
42 #include "un-namespace.h"
43 
44 __weak_reference(__aio_read, aio_read);
45 __weak_reference(__aio_write, aio_write);
46 __weak_reference(__aio_return, aio_return);
47 __weak_reference(__aio_waitcomplete, aio_waitcomplete);
48 __weak_reference(__aio_fsync, aio_fsync);
49 __weak_reference(__lio_listio, lio_listio);
50 
51 typedef void (*aio_func)(union sigval val, struct aiocb *iocb);
52 
53 extern int __sys_aio_read(struct aiocb *iocb);
54 extern int __sys_aio_write(struct aiocb *iocb);
55 extern ssize_t __sys_aio_waitcomplete(struct aiocb **iocbp, struct timespec *timeout);
56 extern ssize_t __sys_aio_return(struct aiocb *iocb);
57 extern int __sys_aio_error(struct aiocb *iocb);
58 extern int __sys_aio_fsync(int op, struct aiocb *iocb);
59 extern int __sys_lio_listio(int mode, struct aiocb * const list[], int nent,
60     struct sigevent *sig);
61 
62 static void
63 aio_dispatch(struct sigev_node *sn)
64 {
65 	aio_func f = sn->sn_func;
66 
67 	f(sn->sn_value, (struct aiocb *)sn->sn_id);
68 }
69 
70 static int
71 aio_sigev_alloc(sigev_id_t id, struct sigevent *sigevent,
72     struct sigev_node **sn, struct sigevent *saved_ev)
73 {
74 	if (__sigev_check_init()) {
75 		/* This might be that thread library is not enabled. */
76 		errno = EINVAL;
77 		return (-1);
78 	}
79 
80 	*sn = __sigev_alloc(SI_ASYNCIO, sigevent, NULL, 1);
81 	if (*sn == NULL) {
82 		errno = EAGAIN;
83 		return (-1);
84 	}
85 
86 	*saved_ev = *sigevent;
87 	(*sn)->sn_id = id;
88 	__sigev_get_sigevent(*sn, sigevent, (*sn)->sn_id);
89 	(*sn)->sn_dispatch = aio_dispatch;
90 
91 	__sigev_list_lock();
92 	__sigev_register(*sn);
93 	__sigev_list_unlock();
94 
95 	return (0);
96 }
97 
98 static int
99 aio_io(struct aiocb *iocb, int (*sysfunc)(struct aiocb *iocb))
100 {
101 	struct sigev_node *sn;
102 	struct sigevent saved_ev;
103 	int ret, err;
104 
105 	if (iocb->aio_sigevent.sigev_notify != SIGEV_THREAD) {
106 		ret = sysfunc(iocb);
107 		return (ret);
108 	}
109 
110 	ret = aio_sigev_alloc((sigev_id_t)iocb, &iocb->aio_sigevent, &sn,
111 			      &saved_ev);
112 	if (ret)
113 		return (ret);
114 	ret = sysfunc(iocb);
115 	iocb->aio_sigevent = saved_ev;
116 	if (ret != 0) {
117 		err = errno;
118 		__sigev_list_lock();
119 		__sigev_delete_node(sn);
120 		__sigev_list_unlock();
121 		errno = err;
122 	}
123 	return (ret);
124 }
125 
126 int
127 __aio_read(struct aiocb *iocb)
128 {
129 
130 	return aio_io(iocb, &__sys_aio_read);
131 }
132 
133 int
134 __aio_write(struct aiocb *iocb)
135 {
136 
137 	return aio_io(iocb, &__sys_aio_write);
138 }
139 
140 ssize_t
141 __aio_waitcomplete(struct aiocb **iocbp, struct timespec *timeout)
142 {
143 	ssize_t ret;
144 	int err;
145 
146 	ret = __sys_aio_waitcomplete(iocbp, timeout);
147 	if (*iocbp) {
148 		if ((*iocbp)->aio_sigevent.sigev_notify == SIGEV_THREAD) {
149 			err = errno;
150 			__sigev_list_lock();
151 			__sigev_delete(SI_ASYNCIO, (sigev_id_t)(*iocbp));
152 			__sigev_list_unlock();
153 			errno = err;
154 		}
155 	}
156 
157 	return (ret);
158 }
159 
160 ssize_t
161 __aio_return(struct aiocb *iocb)
162 {
163 
164 	if (iocb->aio_sigevent.sigev_notify == SIGEV_THREAD) {
165 		if (__sys_aio_error(iocb) == EINPROGRESS) {
166 			/*
167 			 * Fail with EINVAL to match the semantics of
168 			 * __sys_aio_return() for an in-progress
169 			 * request.
170 			 */
171 			errno = EINVAL;
172 			return (-1);
173 		}
174 		__sigev_list_lock();
175 		__sigev_delete(SI_ASYNCIO, (sigev_id_t)iocb);
176 		__sigev_list_unlock();
177 	}
178 
179 	return __sys_aio_return(iocb);
180 }
181 
182 int
183 __aio_fsync(int op, struct aiocb *iocb)
184 {
185 	struct sigev_node *sn;
186 	struct sigevent saved_ev;
187 	int ret, err;
188 
189 	if (iocb->aio_sigevent.sigev_notify != SIGEV_THREAD)
190 		return __sys_aio_fsync(op, iocb);
191 
192 	ret = aio_sigev_alloc((sigev_id_t)iocb, &iocb->aio_sigevent, &sn,
193 			      &saved_ev);
194 	if (ret)
195 		return (ret);
196 	ret = __sys_aio_fsync(op, iocb);
197 	iocb->aio_sigevent = saved_ev;
198 	if (ret != 0) {
199 		err = errno;
200 		__sigev_list_lock();
201 		__sigev_delete_node(sn);
202 		__sigev_list_unlock();
203 		errno = err;
204 	}
205 	return (ret);
206 }
207 
208 int
209 __lio_listio(int mode, struct aiocb * const list[], int nent,
210     struct sigevent *sig)
211 {
212 	struct sigev_node *sn;
213 	struct sigevent saved_ev;
214 	int ret, err;
215 
216 	if (sig == NULL || sig->sigev_notify != SIGEV_THREAD)
217 		return (__sys_lio_listio(mode, list, nent, sig));
218 
219 	ret = aio_sigev_alloc((sigev_id_t)list, sig, &sn, &saved_ev);
220 	if (ret)
221 		return (ret);
222 	ret = __sys_lio_listio(mode, list, nent, sig);
223 	*sig = saved_ev;
224 	if (ret != 0) {
225 		err = errno;
226 		__sigev_list_lock();
227 		__sigev_delete_node(sn);
228 		__sigev_list_unlock();
229 		errno = err;
230 	}
231 	return (ret);
232 }
233