1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 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 19 #ifndef _SYS_AIO_H_ 20 #define _SYS_AIO_H_ 21 22 #include <sys/types.h> 23 #include <sys/signal.h> 24 #ifdef _KERNEL 25 #include <sys/queue.h> 26 #include <sys/event.h> 27 #include <sys/signalvar.h> 28 #include <sys/uio.h> 29 #endif 30 31 /* 32 * Returned by aio_cancel: 33 */ 34 #define AIO_CANCELED 0x1 35 #define AIO_NOTCANCELED 0x2 36 #define AIO_ALLDONE 0x3 37 38 /* 39 * LIO opcodes 40 */ 41 #define LIO_NOP 0x0 42 #define LIO_WRITE 0x1 43 #define LIO_READ 0x2 44 #if __BSD_VISIBLE 45 #define LIO_VECTORED 0x4 46 #define LIO_WRITEV (LIO_WRITE | LIO_VECTORED) 47 #define LIO_READV (LIO_READ | LIO_VECTORED) 48 #endif 49 #if defined(_KERNEL) || defined(_WANT_ALL_LIO_OPCODES) 50 #define LIO_SYNC 0x8 51 #define LIO_DSYNC (0x10 | LIO_SYNC) 52 #define LIO_MLOCK 0x20 53 #endif 54 55 /* 56 * LIO modes 57 */ 58 #define LIO_NOWAIT 0x0 59 #define LIO_WAIT 0x1 60 61 /* 62 * Maximum number of operations in a single lio_listio call 63 */ 64 #define AIO_LISTIO_MAX 16 65 66 #ifdef _KERNEL 67 68 /* Default values of tunables for the AIO worker pool. */ 69 70 #ifndef MAX_AIO_PROCS 71 #define MAX_AIO_PROCS 32 72 #endif 73 74 #ifndef TARGET_AIO_PROCS 75 #define TARGET_AIO_PROCS 4 76 #endif 77 78 #ifndef AIOD_LIFETIME_DEFAULT 79 #define AIOD_LIFETIME_DEFAULT (30 * hz) 80 #endif 81 82 #endif 83 84 /* 85 * Private members for aiocb -- don't access 86 * directly. 87 */ 88 struct __aiocb_private { 89 long status; 90 long error; 91 void *kernelinfo; 92 }; 93 94 /* 95 * I/O control block 96 */ 97 typedef struct aiocb { 98 int aio_fildes; /* File descriptor */ 99 off_t aio_offset; /* File offset for I/O */ 100 volatile void *aio_buf; /* I/O buffer in process space */ 101 size_t aio_nbytes; /* Number of bytes for I/O */ 102 int __spare__[2]; 103 void *__spare2__; 104 int aio_lio_opcode; /* LIO opcode */ 105 int aio_reqprio; /* Request priority -- ignored */ 106 struct __aiocb_private _aiocb_private; 107 struct sigevent aio_sigevent; /* Signal to deliver */ 108 } aiocb_t; 109 110 #define aio_iov aio_buf /* I/O scatter/gather list */ 111 #define aio_iovcnt aio_nbytes /* Length of aio_iov */ 112 113 #ifdef _KERNEL 114 115 typedef void aio_cancel_fn_t(struct kaiocb *); 116 typedef void aio_handle_fn_t(struct kaiocb *); 117 118 /* 119 * Kernel version of an I/O control block. 120 * 121 * Locking key: 122 * * - need not protected 123 * a - locked by kaioinfo lock 124 * b - locked by backend lock 125 * c - locked by aio_job_mtx 126 */ 127 struct kaiocb { 128 TAILQ_ENTRY(kaiocb) list; /* (b) backend-specific list of jobs */ 129 TAILQ_ENTRY(kaiocb) plist; /* (a) lists of pending / done jobs */ 130 TAILQ_ENTRY(kaiocb) allist; /* (a) list of all jobs in proc */ 131 int jobflags; /* (a) job flags */ 132 int inblock; /* (*) input blocks */ 133 int outblock; /* (*) output blocks */ 134 int msgsnd; /* (*) messages sent */ 135 int msgrcv; /* (*) messages received */ 136 struct proc *userproc; /* (*) user process */ 137 struct ucred *cred; /* (*) active credential when created */ 138 struct file *fd_file; /* (*) pointer to file structure */ 139 struct aioliojob *lio; /* (*) optional lio job */ 140 struct aiocb *ujob; /* (*) pointer in userspace of aiocb */ 141 struct knlist klist; /* (a) list of knotes */ 142 struct aiocb uaiocb; /* (*) copy of user I/O control block */ 143 struct uio uio; /* (*) storage for non-vectored uio */ 144 struct iovec iov[1]; /* (*) storage for non-vectored uio */ 145 struct uio *uiop; /* (*) Possibly malloced uio */ 146 ksiginfo_t ksi; /* (a) realtime signal info */ 147 uint64_t seqno; /* (*) job number */ 148 aio_cancel_fn_t *cancel_fn; /* (a) backend cancel function */ 149 aio_handle_fn_t *handle_fn; /* (c) backend handle function */ 150 union { /* Backend-specific data fields */ 151 struct { /* BIO backend */ 152 volatile u_int nbio; /* Number of remaining bios */ 153 int error; /* Worst error of all bios */ 154 long nbytes; /* Bytes completed so far */ 155 }; 156 struct { /* fsync() requests */ 157 int pending; /* (a) number of pending I/O */ 158 }; 159 struct { /* socket backend */ 160 void *backend1; 161 long backend3; 162 int backend4; 163 }; 164 }; 165 }; 166 167 struct socket; 168 struct sockbuf; 169 170 /* 171 * AIO backends should permit cancellation of queued requests waiting to 172 * be serviced by installing a cancel routine while the request is 173 * queued. The cancellation routine should dequeue the request if 174 * necessary and cancel it. Care must be used to handle races between 175 * queueing and dequeueing requests and cancellation. 176 * 177 * When queueing a request somewhere such that it can be cancelled, the 178 * caller should: 179 * 180 * 1) Acquire lock that protects the associated queue. 181 * 2) Call aio_set_cancel_function() to install the cancel routine. 182 * 3) If that fails, the request has a pending cancel and should be 183 * cancelled via aio_cancel(). 184 * 4) Queue the request. 185 * 186 * When dequeueing a request to service it or hand it off to somewhere else, 187 * the caller should: 188 * 189 * 1) Acquire the lock that protects the associated queue. 190 * 2) Dequeue the request. 191 * 3) Call aio_clear_cancel_function() to clear the cancel routine. 192 * 4) If that fails, the cancel routine is about to be called. The 193 * caller should ignore the request. 194 * 195 * The cancel routine should: 196 * 197 * 1) Acquire the lock that protects the associated queue. 198 * 2) Call aio_cancel_cleared() to determine if the request is already 199 * dequeued due to a race with dequeueing thread. 200 * 3) If that fails, dequeue the request. 201 * 4) Cancel the request via aio_cancel(). 202 */ 203 204 bool aio_cancel_cleared(struct kaiocb *job); 205 void aio_cancel(struct kaiocb *job); 206 bool aio_clear_cancel_function(struct kaiocb *job); 207 void aio_complete(struct kaiocb *job, long status, int error); 208 void aio_schedule(struct kaiocb *job, aio_handle_fn_t *func); 209 bool aio_set_cancel_function(struct kaiocb *job, aio_cancel_fn_t *func); 210 void aio_switch_vmspace(struct kaiocb *job); 211 212 #else /* !_KERNEL */ 213 214 struct timespec; 215 216 __BEGIN_DECLS 217 /* 218 * Asynchronously read from a file 219 */ 220 int aio_read(struct aiocb *); 221 #if __BSD_VISIBLE 222 int aio_readv(struct aiocb *); 223 #endif 224 225 /* 226 * Asynchronously write to file 227 */ 228 int aio_write(struct aiocb *); 229 #if __BSD_VISIBLE 230 int aio_writev(struct aiocb *); 231 #endif 232 233 /* 234 * List I/O Asynchronously/synchronously read/write to/from file 235 * "lio_mode" specifies whether or not the I/O is synchronous. 236 * "acb_list" is an array of "nacb_listent" I/O control blocks. 237 * when all I/Os are complete, the optional signal "sig" is sent. 238 */ 239 int lio_listio(int, struct aiocb *__restrict const *__restrict, int, 240 struct sigevent *); 241 242 /* 243 * Get completion status 244 * returns EINPROGRESS until I/O is complete. 245 * this routine does not block. 246 */ 247 int aio_error(const struct aiocb *); 248 249 /* 250 * Finish up I/O, releasing I/O resources and returns the value 251 * that would have been associated with a synchronous I/O request. 252 * This routine must be called once and only once for each 253 * I/O control block who has had I/O associated with it. 254 */ 255 ssize_t aio_return(struct aiocb *); 256 257 /* 258 * Cancel I/O 259 */ 260 int aio_cancel(int, struct aiocb *); 261 262 /* 263 * Suspend until all specified I/O or timeout is complete. 264 */ 265 int aio_suspend(const struct aiocb * const[], int, const struct timespec *); 266 267 /* 268 * Asynchronous mlock 269 */ 270 int aio_mlock(struct aiocb *); 271 272 #if __BSD_VISIBLE 273 ssize_t aio_waitcomplete(struct aiocb **, struct timespec *); 274 #endif 275 276 int aio_fsync(int op, struct aiocb *aiocbp); 277 __END_DECLS 278 279 #endif /* !_KERNEL */ 280 281 #endif /* !_SYS_AIO_H_ */ 282