xref: /freebsd/lib/librt/aio.c (revision ca987d4641cdcd7f27e153db17c5bf064934faf5)
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  * $FreeBSD$
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_write, aio_write);
44 __weak_reference(__aio_return, aio_return);
45 __weak_reference(__aio_waitcomplete, aio_waitcomplete);
46 __weak_reference(__aio_fsync, aio_fsync);
47 __weak_reference(__lio_listio, lio_listio);
48 
49 typedef void (*aio_func)(union sigval val, struct aiocb *iocb);
50 
51 extern int __sys_aio_read(struct aiocb *iocb);
52 extern int __sys_aio_write(struct aiocb *iocb);
53 extern ssize_t __sys_aio_waitcomplete(struct aiocb **iocbp, struct timespec *timeout);
54 extern ssize_t __sys_aio_return(struct aiocb *iocb);
55 extern int __sys_aio_error(struct aiocb *iocb);
56 extern int __sys_aio_fsync(int op, struct aiocb *iocb);
57 extern int __sys_lio_listio(int mode, struct aiocb * const list[], int nent,
58     struct sigevent *sig);
59 
60 static void
61 aio_dispatch(struct sigev_node *sn)
62 {
63 	aio_func f = sn->sn_func;
64 
65 	f(sn->sn_value, (struct aiocb *)sn->sn_id);
66 }
67 
68 static int
69 aio_sigev_alloc(sigev_id_t id, struct sigevent *sigevent,
70     struct sigev_node **sn, struct sigevent *saved_ev)
71 {
72 	if (__sigev_check_init()) {
73 		/* This might be that thread library is not enabled. */
74 		errno = EINVAL;
75 		return (-1);
76 	}
77 
78 	*sn = __sigev_alloc(SI_ASYNCIO, sigevent, NULL, 1);
79 	if (*sn == NULL) {
80 		errno = EAGAIN;
81 		return (-1);
82 	}
83 
84 	*saved_ev = *sigevent;
85 	(*sn)->sn_id = id;
86 	__sigev_get_sigevent(*sn, sigevent, (*sn)->sn_id);
87 	(*sn)->sn_dispatch = aio_dispatch;
88 
89 	__sigev_list_lock();
90 	__sigev_register(*sn);
91 	__sigev_list_unlock();
92 
93 	return (0);
94 }
95 
96 static int
97 aio_io(struct aiocb *iocb, int (*sysfunc)(struct aiocb *iocb))
98 {
99 	struct sigev_node *sn;
100 	struct sigevent saved_ev;
101 	int ret, err;
102 
103 	if (iocb->aio_sigevent.sigev_notify != SIGEV_THREAD) {
104 		ret = sysfunc(iocb);
105 		return (ret);
106 	}
107 
108 	ret = aio_sigev_alloc((sigev_id_t)iocb, &iocb->aio_sigevent, &sn,
109 			      &saved_ev);
110 	if (ret)
111 		return (ret);
112 	ret = sysfunc(iocb);
113 	iocb->aio_sigevent = saved_ev;
114 	if (ret != 0) {
115 		err = errno;
116 		__sigev_list_lock();
117 		__sigev_delete_node(sn);
118 		__sigev_list_unlock();
119 		errno = err;
120 	}
121 	return (ret);
122 }
123 
124 int
125 __aio_read(struct aiocb *iocb)
126 {
127 
128 	return aio_io(iocb, &__sys_aio_read);
129 }
130 
131 int
132 __aio_write(struct aiocb *iocb)
133 {
134 
135 	return aio_io(iocb, &__sys_aio_write);
136 }
137 
138 ssize_t
139 __aio_waitcomplete(struct aiocb **iocbp, struct timespec *timeout)
140 {
141 	ssize_t ret;
142 	int err;
143 
144 	ret = __sys_aio_waitcomplete(iocbp, timeout);
145 	if (*iocbp) {
146 		if ((*iocbp)->aio_sigevent.sigev_notify == SIGEV_THREAD) {
147 			err = errno;
148 			__sigev_list_lock();
149 			__sigev_delete(SI_ASYNCIO, (sigev_id_t)(*iocbp));
150 			__sigev_list_unlock();
151 			errno = err;
152 		}
153 	}
154 
155 	return (ret);
156 }
157 
158 ssize_t
159 __aio_return(struct aiocb *iocb)
160 {
161 
162 	if (iocb->aio_sigevent.sigev_notify == SIGEV_THREAD) {
163 		if (__sys_aio_error(iocb) == EINPROGRESS) {
164 			/*
165 			 * Fail with EINVAL to match the semantics of
166 			 * __sys_aio_return() for an in-progress
167 			 * request.
168 			 */
169 			errno = EINVAL;
170 			return (-1);
171 		}
172 		__sigev_list_lock();
173 		__sigev_delete(SI_ASYNCIO, (sigev_id_t)iocb);
174 		__sigev_list_unlock();
175 	}
176 
177 	return __sys_aio_return(iocb);
178 }
179 
180 int
181 __aio_fsync(int op, struct aiocb *iocb)
182 {
183 	struct sigev_node *sn;
184 	struct sigevent saved_ev;
185 	int ret, err;
186 
187 	if (iocb->aio_sigevent.sigev_notify != SIGEV_THREAD)
188 		return __sys_aio_fsync(op, iocb);
189 
190 	ret = aio_sigev_alloc((sigev_id_t)iocb, &iocb->aio_sigevent, &sn,
191 			      &saved_ev);
192 	if (ret)
193 		return (ret);
194 	ret = __sys_aio_fsync(op, iocb);
195 	iocb->aio_sigevent = saved_ev;
196 	if (ret != 0) {
197 		err = errno;
198 		__sigev_list_lock();
199 		__sigev_delete_node(sn);
200 		__sigev_list_unlock();
201 		errno = err;
202 	}
203 	return (ret);
204 }
205 
206 int
207 __lio_listio(int mode, struct aiocb * const list[], int nent,
208     struct sigevent *sig)
209 {
210 	struct sigev_node *sn;
211 	struct sigevent saved_ev;
212 	int ret, err;
213 
214 	if (sig == NULL || sig->sigev_notify != SIGEV_THREAD)
215 		return (__sys_lio_listio(mode, list, nent, sig));
216 
217 	ret = aio_sigev_alloc((sigev_id_t)list, sig, &sn, &saved_ev);
218 	if (ret)
219 		return (ret);
220 	ret = __sys_lio_listio(mode, list, nent, sig);
221 	*sig = saved_ev;
222 	if (ret != 0) {
223 		err = errno;
224 		__sigev_list_lock();
225 		__sigev_delete_node(sn);
226 		__sigev_list_unlock();
227 		errno = err;
228 	}
229 	return (ret);
230 }
231