1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 1997 John S. Dyson. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. John S. Dyson's name may not be used to endorse or promote products 12 * derived from this software without specific prior written permission. 13 * 14 * DISCLAIMER: This code isn't warranted to do anything useful. Anything 15 * bad that happens because of using this software isn't the responsibility 16 * of the author. This software is distributed AS-IS. 17 * 18 * $FreeBSD$ 19 */ 20 21 #ifndef _SYS_AIO_H_ 22 #define _SYS_AIO_H_ 23 24 #include <sys/types.h> 25 #include <sys/signal.h> 26 #ifdef _KERNEL 27 #include <sys/queue.h> 28 #include <sys/event.h> 29 #include <sys/signalvar.h> 30 #endif 31 32 /* 33 * Returned by aio_cancel: 34 */ 35 #define AIO_CANCELED 0x1 36 #define AIO_NOTCANCELED 0x2 37 #define AIO_ALLDONE 0x3 38 39 /* 40 * LIO opcodes 41 */ 42 #define LIO_NOP 0x0 43 #define LIO_WRITE 0x1 44 #define LIO_READ 0x2 45 #ifdef _KERNEL 46 #define LIO_SYNC 0x3 47 #define LIO_MLOCK 0x4 48 #endif 49 50 /* 51 * LIO modes 52 */ 53 #define LIO_NOWAIT 0x0 54 #define LIO_WAIT 0x1 55 56 /* 57 * Maximum number of operations in a single lio_listio call 58 */ 59 #define AIO_LISTIO_MAX 16 60 61 #ifdef _KERNEL 62 63 /* Default values of tunables for the AIO worker pool. */ 64 65 #ifndef MAX_AIO_PROCS 66 #define MAX_AIO_PROCS 32 67 #endif 68 69 #ifndef TARGET_AIO_PROCS 70 #define TARGET_AIO_PROCS 4 71 #endif 72 73 #ifndef AIOD_LIFETIME_DEFAULT 74 #define AIOD_LIFETIME_DEFAULT (30 * hz) 75 #endif 76 77 #endif 78 79 /* 80 * Private members for aiocb -- don't access 81 * directly. 82 */ 83 struct __aiocb_private { 84 long status; 85 long error; 86 void *kernelinfo; 87 }; 88 89 /* 90 * I/O control block 91 */ 92 typedef struct aiocb { 93 int aio_fildes; /* File descriptor */ 94 off_t aio_offset; /* File offset for I/O */ 95 volatile void *aio_buf; /* I/O buffer in process space */ 96 size_t aio_nbytes; /* Number of bytes for I/O */ 97 int __spare__[2]; 98 void *__spare2__; 99 int aio_lio_opcode; /* LIO opcode */ 100 int aio_reqprio; /* Request priority -- ignored */ 101 struct __aiocb_private _aiocb_private; 102 struct sigevent aio_sigevent; /* Signal to deliver */ 103 } aiocb_t; 104 105 #ifdef _KERNEL 106 107 typedef void aio_cancel_fn_t(struct kaiocb *); 108 typedef void aio_handle_fn_t(struct kaiocb *); 109 110 /* 111 * Kernel version of an I/O control block. 112 * 113 * Locking key: 114 * * - need not protected 115 * a - locked by kaioinfo lock 116 * b - locked by backend lock 117 * c - locked by aio_job_mtx 118 */ 119 struct kaiocb { 120 TAILQ_ENTRY(kaiocb) list; /* (b) backend-specific list of jobs */ 121 TAILQ_ENTRY(kaiocb) plist; /* (a) lists of pending / done jobs */ 122 TAILQ_ENTRY(kaiocb) allist; /* (a) list of all jobs in proc */ 123 int jobflags; /* (a) job flags */ 124 int inblock; /* (*) input blocks */ 125 int outblock; /* (*) output blocks */ 126 int msgsnd; /* (*) messages sent */ 127 int msgrcv; /* (*) messages received */ 128 struct proc *userproc; /* (*) user process */ 129 struct ucred *cred; /* (*) active credential when created */ 130 struct file *fd_file; /* (*) pointer to file structure */ 131 struct aioliojob *lio; /* (*) optional lio job */ 132 struct aiocb *ujob; /* (*) pointer in userspace of aiocb */ 133 struct knlist klist; /* (a) list of knotes */ 134 struct aiocb uaiocb; /* (*) copy of user I/O control block */ 135 ksiginfo_t ksi; /* (a) realtime signal info */ 136 uint64_t seqno; /* (*) job number */ 137 aio_cancel_fn_t *cancel_fn; /* (a) backend cancel function */ 138 aio_handle_fn_t *handle_fn; /* (c) backend handle function */ 139 union { /* Backend-specific data fields */ 140 struct { /* fsync() requests */ 141 int pending; /* (a) number of pending I/O */ 142 }; 143 struct { /* socket backend */ 144 void *backend1; 145 long backend3; 146 int backend4; 147 }; 148 }; 149 }; 150 151 struct socket; 152 struct sockbuf; 153 154 /* 155 * AIO backends should permit cancellation of queued requests waiting to 156 * be serviced by installing a cancel routine while the request is 157 * queued. The cancellation routine should dequeue the request if 158 * necessary and cancel it. Care must be used to handle races between 159 * queueing and dequeueing requests and cancellation. 160 * 161 * When queueing a request somewhere such that it can be cancelled, the 162 * caller should: 163 * 164 * 1) Acquire lock that protects the associated queue. 165 * 2) Call aio_set_cancel_function() to install the cancel routine. 166 * 3) If that fails, the request has a pending cancel and should be 167 * cancelled via aio_cancel(). 168 * 4) Queue the request. 169 * 170 * When dequeueing a request to service it or hand it off to somewhere else, 171 * the caller should: 172 * 173 * 1) Acquire the lock that protects the associated queue. 174 * 2) Dequeue the request. 175 * 3) Call aio_clear_cancel_function() to clear the cancel routine. 176 * 4) If that fails, the cancel routine is about to be called. The 177 * caller should ignore the request. 178 * 179 * The cancel routine should: 180 * 181 * 1) Acquire the lock that protects the associated queue. 182 * 2) Call aio_cancel_cleared() to determine if the request is already 183 * dequeued due to a race with dequeueing thread. 184 * 3) If that fails, dequeue the request. 185 * 4) Cancel the request via aio_cancel(). 186 */ 187 188 bool aio_cancel_cleared(struct kaiocb *job); 189 void aio_cancel(struct kaiocb *job); 190 bool aio_clear_cancel_function(struct kaiocb *job); 191 void aio_complete(struct kaiocb *job, long status, int error); 192 void aio_schedule(struct kaiocb *job, aio_handle_fn_t *func); 193 bool aio_set_cancel_function(struct kaiocb *job, aio_cancel_fn_t *func); 194 void aio_switch_vmspace(struct kaiocb *job); 195 196 #else /* !_KERNEL */ 197 198 struct timespec; 199 200 __BEGIN_DECLS 201 /* 202 * Asynchronously read from a file 203 */ 204 int aio_read(struct aiocb *); 205 206 /* 207 * Asynchronously write to file 208 */ 209 int aio_write(struct aiocb *); 210 211 /* 212 * List I/O Asynchronously/synchronously read/write to/from file 213 * "lio_mode" specifies whether or not the I/O is synchronous. 214 * "acb_list" is an array of "nacb_listent" I/O control blocks. 215 * when all I/Os are complete, the optional signal "sig" is sent. 216 */ 217 int lio_listio(int, struct aiocb *__restrict const *__restrict, int, 218 struct sigevent *); 219 220 /* 221 * Get completion status 222 * returns EINPROGRESS until I/O is complete. 223 * this routine does not block. 224 */ 225 int aio_error(const struct aiocb *); 226 227 /* 228 * Finish up I/O, releasing I/O resources and returns the value 229 * that would have been associated with a synchronous I/O request. 230 * This routine must be called once and only once for each 231 * I/O control block who has had I/O associated with it. 232 */ 233 ssize_t aio_return(struct aiocb *); 234 235 /* 236 * Cancel I/O 237 */ 238 int aio_cancel(int, struct aiocb *); 239 240 /* 241 * Suspend until all specified I/O or timeout is complete. 242 */ 243 int aio_suspend(const struct aiocb * const[], int, const struct timespec *); 244 245 /* 246 * Asynchronous mlock 247 */ 248 int aio_mlock(struct aiocb *); 249 250 #if __BSD_VISIBLE 251 ssize_t aio_waitcomplete(struct aiocb **, struct timespec *); 252 #endif 253 254 int aio_fsync(int op, struct aiocb *aiocbp); 255 __END_DECLS 256 257 #endif /* !_KERNEL */ 258 259 #endif /* !_SYS_AIO_H_ */ 260