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 #if __BSD_VISIBLE 55 #define LIO_FOFFSET 0x40 56 #endif 57 58 /* aio_read2/aio_write2 flags */ 59 #if __BSD_VISIBLE 60 #define AIO_OP2_FOFFSET 0x00000001 61 #define AIO_OP2_VECTORED 0x00000002 62 #endif 63 64 /* 65 * LIO modes 66 */ 67 #define LIO_NOWAIT 0x0 68 #define LIO_WAIT 0x1 69 70 /* 71 * Maximum number of operations in a single lio_listio call 72 */ 73 #define AIO_LISTIO_MAX 16 74 75 #ifdef _KERNEL 76 77 /* Default values of tunables for the AIO worker pool. */ 78 79 #ifndef MAX_AIO_PROCS 80 #define MAX_AIO_PROCS 32 81 #endif 82 83 #ifndef TARGET_AIO_PROCS 84 #define TARGET_AIO_PROCS 4 85 #endif 86 87 #ifndef AIOD_LIFETIME_DEFAULT 88 #define AIOD_LIFETIME_DEFAULT (30 * hz) 89 #endif 90 91 #endif 92 93 /* 94 * Private members for aiocb -- don't access 95 * directly. 96 */ 97 struct __aiocb_private { 98 long status; 99 long error; 100 void *kernelinfo; 101 }; 102 103 /* 104 * I/O control block 105 */ 106 typedef struct aiocb { 107 int aio_fildes; /* File descriptor */ 108 off_t aio_offset; /* File offset for I/O */ 109 volatile void *aio_buf; /* I/O buffer in process space */ 110 size_t aio_nbytes; /* Number of bytes for I/O */ 111 int __spare__[2]; 112 void *__spare2__; 113 int aio_lio_opcode; /* LIO opcode */ 114 int aio_reqprio; /* Request priority -- ignored */ 115 struct __aiocb_private _aiocb_private; 116 struct sigevent aio_sigevent; /* Signal to deliver */ 117 } aiocb_t; 118 119 #define aio_iov aio_buf /* I/O scatter/gather list */ 120 #define aio_iovcnt aio_nbytes /* Length of aio_iov */ 121 122 #ifdef _KERNEL 123 124 typedef void aio_cancel_fn_t(struct kaiocb *); 125 typedef void aio_handle_fn_t(struct kaiocb *); 126 127 /* 128 * Kernel version of an I/O control block. 129 * 130 * Locking key: 131 * * - need not protected 132 * a - locked by kaioinfo lock 133 * b - locked by backend lock 134 * c - locked by aio_job_mtx 135 */ 136 struct kaiocb { 137 TAILQ_ENTRY(kaiocb) list; /* (b) backend-specific list of jobs */ 138 TAILQ_ENTRY(kaiocb) plist; /* (a) lists of pending / done jobs */ 139 TAILQ_ENTRY(kaiocb) allist; /* (a) list of all jobs in proc */ 140 int jobflags; /* (a) job flags */ 141 int ioflags; /* (*) io flags */ 142 int inblock; /* (*) input blocks */ 143 int outblock; /* (*) output blocks */ 144 int msgsnd; /* (*) messages sent */ 145 int msgrcv; /* (*) messages received */ 146 struct proc *userproc; /* (*) user process */ 147 struct ucred *cred; /* (*) active credential when created */ 148 struct file *fd_file; /* (*) pointer to file structure */ 149 struct aioliojob *lio; /* (*) optional lio job */ 150 struct aiocb *ujob; /* (*) pointer in userspace of aiocb */ 151 struct knlist klist; /* (a) list of knotes */ 152 struct aiocb uaiocb; /* (*) copy of user I/O control block */ 153 struct uio uio; /* (*) storage for non-vectored uio */ 154 struct iovec iov[1]; /* (*) storage for non-vectored uio */ 155 struct uio *uiop; /* (*) Possibly malloced uio */ 156 ksiginfo_t ksi; /* (a) realtime signal info */ 157 uint64_t seqno; /* (*) job number */ 158 aio_cancel_fn_t *cancel_fn; /* (a) backend cancel function */ 159 aio_handle_fn_t *handle_fn; /* (c) backend handle function */ 160 union { /* Backend-specific data fields */ 161 struct { /* BIO backend */ 162 volatile u_int nbio; /* Number of remaining bios */ 163 int error; /* Worst error of all bios */ 164 long nbytes; /* Bytes completed so far */ 165 }; 166 struct { /* fsync() requests */ 167 int pending; /* (a) number of pending I/O */ 168 }; 169 struct { /* socket backend */ 170 void *backend1; 171 long backend3; 172 int backend4; 173 }; 174 }; 175 }; 176 177 struct socket; 178 struct sockbuf; 179 180 /* 181 * AIO backends should permit cancellation of queued requests waiting to 182 * be serviced by installing a cancel routine while the request is 183 * queued. The cancellation routine should dequeue the request if 184 * necessary and cancel it. Care must be used to handle races between 185 * queueing and dequeueing requests and cancellation. 186 * 187 * When queueing a request somewhere such that it can be cancelled, the 188 * caller should: 189 * 190 * 1) Acquire lock that protects the associated queue. 191 * 2) Call aio_set_cancel_function() to install the cancel routine. 192 * 3) If that fails, the request has a pending cancel and should be 193 * cancelled via aio_cancel(). 194 * 4) Queue the request. 195 * 196 * When dequeueing a request to service it or hand it off to somewhere else, 197 * the caller should: 198 * 199 * 1) Acquire the lock that protects the associated queue. 200 * 2) Dequeue the request. 201 * 3) Call aio_clear_cancel_function() to clear the cancel routine. 202 * 4) If that fails, the cancel routine is about to be called. The 203 * caller should ignore the request. 204 * 205 * The cancel routine should: 206 * 207 * 1) Acquire the lock that protects the associated queue. 208 * 2) Call aio_cancel_cleared() to determine if the request is already 209 * dequeued due to a race with dequeueing thread. 210 * 3) If that fails, dequeue the request. 211 * 4) Cancel the request via aio_cancel(). 212 */ 213 214 bool aio_cancel_cleared(struct kaiocb *job); 215 void aio_cancel(struct kaiocb *job); 216 bool aio_clear_cancel_function(struct kaiocb *job); 217 void aio_complete(struct kaiocb *job, long status, int error); 218 void aio_schedule(struct kaiocb *job, aio_handle_fn_t *func); 219 bool aio_set_cancel_function(struct kaiocb *job, aio_cancel_fn_t *func); 220 void aio_switch_vmspace(struct kaiocb *job); 221 222 #else /* !_KERNEL */ 223 224 struct timespec; 225 226 __BEGIN_DECLS 227 /* 228 * Asynchronously read from a file 229 */ 230 int aio_read(struct aiocb *); 231 #if __BSD_VISIBLE 232 int aio_readv(struct aiocb *); 233 #endif 234 235 /* 236 * Asynchronously write to file 237 */ 238 int aio_write(struct aiocb *); 239 #if __BSD_VISIBLE 240 int aio_writev(struct aiocb *); 241 #endif 242 243 /* 244 * List I/O Asynchronously/synchronously read/write to/from file 245 * "lio_mode" specifies whether or not the I/O is synchronous. 246 * "acb_list" is an array of "nacb_listent" I/O control blocks. 247 * when all I/Os are complete, the optional signal "sig" is sent. 248 */ 249 int lio_listio(int, struct aiocb *__restrict const *__restrict, int, 250 struct sigevent *); 251 252 /* 253 * Get completion status 254 * returns EINPROGRESS until I/O is complete. 255 * this routine does not block. 256 */ 257 int aio_error(const struct aiocb *); 258 259 /* 260 * Finish up I/O, releasing I/O resources and returns the value 261 * that would have been associated with a synchronous I/O request. 262 * This routine must be called once and only once for each 263 * I/O control block who has had I/O associated with it. 264 */ 265 ssize_t aio_return(struct aiocb *); 266 267 /* 268 * Cancel I/O 269 */ 270 int aio_cancel(int, struct aiocb *); 271 272 /* 273 * Suspend until all specified I/O or timeout is complete. 274 */ 275 int aio_suspend(const struct aiocb * const[], int, const struct timespec *); 276 277 /* 278 * Asynchronous mlock 279 */ 280 int aio_mlock(struct aiocb *); 281 282 #if __BSD_VISIBLE 283 ssize_t aio_waitcomplete(struct aiocb **, struct timespec *); 284 int aio_read2(struct aiocb *, int); 285 int aio_write2(struct aiocb *, int); 286 #endif 287 288 int aio_fsync(int op, struct aiocb *aiocbp); 289 __END_DECLS 290 291 #endif /* !_KERNEL */ 292 293 #endif /* !_SYS_AIO_H_ */ 294