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 { /* BIO backend */ 141 struct bio *bp; /* (*) BIO pointer */ 142 struct buf *pbuf; /* (*) buffer pointer */ 143 struct vm_page *pages[btoc(MAXPHYS)+1]; /* (*) */ 144 int npages; /* (*) number of pages */ 145 }; 146 struct { /* fsync() requests */ 147 int pending; /* (a) number of pending I/O */ 148 }; 149 struct { 150 void *backend1; 151 void *backend2; 152 long backend3; 153 int backend4; 154 }; 155 }; 156 }; 157 158 struct socket; 159 struct sockbuf; 160 161 /* 162 * AIO backends should permit cancellation of queued requests waiting to 163 * be serviced by installing a cancel routine while the request is 164 * queued. The cancellation routine should dequeue the request if 165 * necessary and cancel it. Care must be used to handle races between 166 * queueing and dequeueing requests and cancellation. 167 * 168 * When queueing a request somewhere such that it can be cancelled, the 169 * caller should: 170 * 171 * 1) Acquire lock that protects the associated queue. 172 * 2) Call aio_set_cancel_function() to install the cancel routine. 173 * 3) If that fails, the request has a pending cancel and should be 174 * cancelled via aio_cancel(). 175 * 4) Queue the request. 176 * 177 * When dequeueing a request to service it or hand it off to somewhere else, 178 * the caller should: 179 * 180 * 1) Acquire the lock that protects the associated queue. 181 * 2) Dequeue the request. 182 * 3) Call aio_clear_cancel_function() to clear the cancel routine. 183 * 4) If that fails, the cancel routine is about to be called. The 184 * caller should ignore the request. 185 * 186 * The cancel routine should: 187 * 188 * 1) Acquire the lock that protects the associated queue. 189 * 2) Call aio_cancel_cleared() to determine if the request is already 190 * dequeued due to a race with dequeueing thread. 191 * 3) If that fails, dequeue the request. 192 * 4) Cancel the request via aio_cancel(). 193 */ 194 195 bool aio_cancel_cleared(struct kaiocb *job); 196 void aio_cancel(struct kaiocb *job); 197 bool aio_clear_cancel_function(struct kaiocb *job); 198 void aio_complete(struct kaiocb *job, long status, int error); 199 void aio_schedule(struct kaiocb *job, aio_handle_fn_t *func); 200 bool aio_set_cancel_function(struct kaiocb *job, aio_cancel_fn_t *func); 201 void aio_switch_vmspace(struct kaiocb *job); 202 203 #else /* !_KERNEL */ 204 205 struct timespec; 206 207 __BEGIN_DECLS 208 /* 209 * Asynchronously read from a file 210 */ 211 int aio_read(struct aiocb *); 212 213 /* 214 * Asynchronously write to file 215 */ 216 int aio_write(struct aiocb *); 217 218 /* 219 * List I/O Asynchronously/synchronously read/write to/from file 220 * "lio_mode" specifies whether or not the I/O is synchronous. 221 * "acb_list" is an array of "nacb_listent" I/O control blocks. 222 * when all I/Os are complete, the optional signal "sig" is sent. 223 */ 224 int lio_listio(int, struct aiocb *__restrict const *__restrict, int, 225 struct sigevent *); 226 227 /* 228 * Get completion status 229 * returns EINPROGRESS until I/O is complete. 230 * this routine does not block. 231 */ 232 int aio_error(const struct aiocb *); 233 234 /* 235 * Finish up I/O, releasing I/O resources and returns the value 236 * that would have been associated with a synchronous I/O request. 237 * This routine must be called once and only once for each 238 * I/O control block who has had I/O associated with it. 239 */ 240 ssize_t aio_return(struct aiocb *); 241 242 /* 243 * Cancel I/O 244 */ 245 int aio_cancel(int, struct aiocb *); 246 247 /* 248 * Suspend until all specified I/O or timeout is complete. 249 */ 250 int aio_suspend(const struct aiocb * const[], int, const struct timespec *); 251 252 /* 253 * Asynchronous mlock 254 */ 255 int aio_mlock(struct aiocb *); 256 257 #if __BSD_VISIBLE 258 ssize_t aio_waitcomplete(struct aiocb **, struct timespec *); 259 #endif 260 261 int aio_fsync(int op, struct aiocb *aiocbp); 262 __END_DECLS 263 264 #endif /* !_KERNEL */ 265 266 #endif /* !_SYS_AIO_H_ */ 267