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 #include <sys/uio.h> 31 #endif 32 33 /* 34 * Returned by aio_cancel: 35 */ 36 #define AIO_CANCELED 0x1 37 #define AIO_NOTCANCELED 0x2 38 #define AIO_ALLDONE 0x3 39 40 /* 41 * LIO opcodes 42 */ 43 #define LIO_NOP 0x0 44 #define LIO_WRITE 0x1 45 #define LIO_READ 0x2 46 #if defined(_KERNEL) || defined(_WANT_ALL_LIO_OPCODES) 47 #define LIO_SYNC 0x3 48 #define LIO_MLOCK 0x4 49 #define LIO_WRITEV 0x5 50 #define LIO_READV 0x6 51 #define LIO_DSYNC 0x7 52 #endif 53 54 /* 55 * LIO modes 56 */ 57 #define LIO_NOWAIT 0x0 58 #define LIO_WAIT 0x1 59 60 /* 61 * Maximum number of operations in a single lio_listio call 62 */ 63 #define AIO_LISTIO_MAX 16 64 65 #ifdef _KERNEL 66 67 /* Default values of tunables for the AIO worker pool. */ 68 69 #ifndef MAX_AIO_PROCS 70 #define MAX_AIO_PROCS 32 71 #endif 72 73 #ifndef TARGET_AIO_PROCS 74 #define TARGET_AIO_PROCS 4 75 #endif 76 77 #ifndef AIOD_LIFETIME_DEFAULT 78 #define AIOD_LIFETIME_DEFAULT (30 * hz) 79 #endif 80 81 #endif 82 83 /* 84 * Private members for aiocb -- don't access 85 * directly. 86 */ 87 struct __aiocb_private { 88 long status; 89 long error; 90 void *kernelinfo; 91 }; 92 93 /* 94 * I/O control block 95 */ 96 typedef struct aiocb { 97 int aio_fildes; /* File descriptor */ 98 off_t aio_offset; /* File offset for I/O */ 99 volatile void *aio_buf; /* I/O buffer in process space */ 100 size_t aio_nbytes; /* Number of bytes for I/O */ 101 int __spare__[2]; 102 void *__spare2__; 103 int aio_lio_opcode; /* LIO opcode */ 104 int aio_reqprio; /* Request priority -- ignored */ 105 struct __aiocb_private _aiocb_private; 106 struct sigevent aio_sigevent; /* Signal to deliver */ 107 } aiocb_t; 108 109 #define aio_iov aio_buf /* I/O scatter/gather list */ 110 #define aio_iovcnt aio_nbytes /* Length of aio_iov */ 111 112 #ifdef _KERNEL 113 114 typedef void aio_cancel_fn_t(struct kaiocb *); 115 typedef void aio_handle_fn_t(struct kaiocb *); 116 117 /* 118 * Kernel version of an I/O control block. 119 * 120 * Locking key: 121 * * - need not protected 122 * a - locked by kaioinfo lock 123 * b - locked by backend lock 124 * c - locked by aio_job_mtx 125 */ 126 struct kaiocb { 127 TAILQ_ENTRY(kaiocb) list; /* (b) backend-specific list of jobs */ 128 TAILQ_ENTRY(kaiocb) plist; /* (a) lists of pending / done jobs */ 129 TAILQ_ENTRY(kaiocb) allist; /* (a) list of all jobs in proc */ 130 int jobflags; /* (a) job flags */ 131 int inblock; /* (*) input blocks */ 132 int outblock; /* (*) output blocks */ 133 int msgsnd; /* (*) messages sent */ 134 int msgrcv; /* (*) messages received */ 135 struct proc *userproc; /* (*) user process */ 136 struct ucred *cred; /* (*) active credential when created */ 137 struct file *fd_file; /* (*) pointer to file structure */ 138 struct aioliojob *lio; /* (*) optional lio job */ 139 struct aiocb *ujob; /* (*) pointer in userspace of aiocb */ 140 struct knlist klist; /* (a) list of knotes */ 141 struct aiocb uaiocb; /* (*) copy of user I/O control block */ 142 struct uio uio; /* (*) storage for non-vectored uio */ 143 struct iovec iov[1]; /* (*) storage for non-vectored uio */ 144 struct uio *uiop; /* (*) Possibly malloced uio */ 145 ksiginfo_t ksi; /* (a) realtime signal info */ 146 uint64_t seqno; /* (*) job number */ 147 aio_cancel_fn_t *cancel_fn; /* (a) backend cancel function */ 148 aio_handle_fn_t *handle_fn; /* (c) backend handle function */ 149 union { /* Backend-specific data fields */ 150 struct { /* BIO backend */ 151 int nbio; /* Number of remaining bios */ 152 int error; /* Worst error of all bios */ 153 long nbytes; /* Bytes completed so far */ 154 }; 155 struct { /* fsync() requests */ 156 int pending; /* (a) number of pending I/O */ 157 }; 158 struct { /* socket backend */ 159 void *backend1; 160 long backend3; 161 int backend4; 162 }; 163 }; 164 }; 165 166 struct socket; 167 struct sockbuf; 168 169 /* 170 * AIO backends should permit cancellation of queued requests waiting to 171 * be serviced by installing a cancel routine while the request is 172 * queued. The cancellation routine should dequeue the request if 173 * necessary and cancel it. Care must be used to handle races between 174 * queueing and dequeueing requests and cancellation. 175 * 176 * When queueing a request somewhere such that it can be cancelled, the 177 * caller should: 178 * 179 * 1) Acquire lock that protects the associated queue. 180 * 2) Call aio_set_cancel_function() to install the cancel routine. 181 * 3) If that fails, the request has a pending cancel and should be 182 * cancelled via aio_cancel(). 183 * 4) Queue the request. 184 * 185 * When dequeueing a request to service it or hand it off to somewhere else, 186 * the caller should: 187 * 188 * 1) Acquire the lock that protects the associated queue. 189 * 2) Dequeue the request. 190 * 3) Call aio_clear_cancel_function() to clear the cancel routine. 191 * 4) If that fails, the cancel routine is about to be called. The 192 * caller should ignore the request. 193 * 194 * The cancel routine should: 195 * 196 * 1) Acquire the lock that protects the associated queue. 197 * 2) Call aio_cancel_cleared() to determine if the request is already 198 * dequeued due to a race with dequeueing thread. 199 * 3) If that fails, dequeue the request. 200 * 4) Cancel the request via aio_cancel(). 201 */ 202 203 bool aio_cancel_cleared(struct kaiocb *job); 204 void aio_cancel(struct kaiocb *job); 205 bool aio_clear_cancel_function(struct kaiocb *job); 206 void aio_complete(struct kaiocb *job, long status, int error); 207 void aio_schedule(struct kaiocb *job, aio_handle_fn_t *func); 208 bool aio_set_cancel_function(struct kaiocb *job, aio_cancel_fn_t *func); 209 void aio_switch_vmspace(struct kaiocb *job); 210 211 #else /* !_KERNEL */ 212 213 struct timespec; 214 215 __BEGIN_DECLS 216 /* 217 * Asynchronously read from a file 218 */ 219 int aio_read(struct aiocb *); 220 #if __BSD_VISIBLE 221 int aio_readv(struct aiocb *); 222 #endif 223 224 /* 225 * Asynchronously write to file 226 */ 227 int aio_write(struct aiocb *); 228 #if __BSD_VISIBLE 229 int aio_writev(struct aiocb *); 230 #endif 231 232 /* 233 * List I/O Asynchronously/synchronously read/write to/from file 234 * "lio_mode" specifies whether or not the I/O is synchronous. 235 * "acb_list" is an array of "nacb_listent" I/O control blocks. 236 * when all I/Os are complete, the optional signal "sig" is sent. 237 */ 238 int lio_listio(int, struct aiocb *__restrict const *__restrict, int, 239 struct sigevent *); 240 241 /* 242 * Get completion status 243 * returns EINPROGRESS until I/O is complete. 244 * this routine does not block. 245 */ 246 int aio_error(const struct aiocb *); 247 248 /* 249 * Finish up I/O, releasing I/O resources and returns the value 250 * that would have been associated with a synchronous I/O request. 251 * This routine must be called once and only once for each 252 * I/O control block who has had I/O associated with it. 253 */ 254 ssize_t aio_return(struct aiocb *); 255 256 /* 257 * Cancel I/O 258 */ 259 int aio_cancel(int, struct aiocb *); 260 261 /* 262 * Suspend until all specified I/O or timeout is complete. 263 */ 264 int aio_suspend(const struct aiocb * const[], int, const struct timespec *); 265 266 /* 267 * Asynchronous mlock 268 */ 269 int aio_mlock(struct aiocb *); 270 271 #if __BSD_VISIBLE 272 ssize_t aio_waitcomplete(struct aiocb **, struct timespec *); 273 #endif 274 275 int aio_fsync(int op, struct aiocb *aiocbp); 276 __END_DECLS 277 278 #endif /* !_KERNEL */ 279 280 #endif /* !_SYS_AIO_H_ */ 281