1 /*- 2 * Copyright (c) 1997 John S. Dyson. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. John S. Dyson's name may not be used to endorse or promote products 10 * derived from this software without specific prior written permission. 11 * 12 * DISCLAIMER: This code isn't warranted to do anything useful. Anything 13 * bad that happens because of using this software isn't the responsibility 14 * of the author. This software is distributed AS-IS. 15 * 16 * $FreeBSD$ 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 #endif 29 30 /* 31 * Returned by aio_cancel: 32 */ 33 #define AIO_CANCELED 0x1 34 #define AIO_NOTCANCELED 0x2 35 #define AIO_ALLDONE 0x3 36 37 /* 38 * LIO opcodes 39 */ 40 #define LIO_NOP 0x0 41 #define LIO_WRITE 0x1 42 #define LIO_READ 0x2 43 #ifdef _KERNEL 44 #define LIO_SYNC 0x3 45 #define LIO_MLOCK 0x4 46 #endif 47 48 /* 49 * LIO modes 50 */ 51 #define LIO_NOWAIT 0x0 52 #define LIO_WAIT 0x1 53 54 /* 55 * Maximum number of allowed LIO operations 56 */ 57 #define AIO_LISTIO_MAX 16 58 59 #ifdef _KERNEL 60 61 /* Default values of tunables for the AIO worker pool. */ 62 63 #ifndef MAX_AIO_PROCS 64 #define MAX_AIO_PROCS 32 65 #endif 66 67 #ifndef TARGET_AIO_PROCS 68 #define TARGET_AIO_PROCS 4 69 #endif 70 71 #ifndef AIOD_LIFETIME_DEFAULT 72 #define AIOD_LIFETIME_DEFAULT (30 * hz) 73 #endif 74 75 #endif 76 77 /* 78 * Private members for aiocb -- don't access 79 * directly. 80 */ 81 struct __aiocb_private { 82 long status; 83 long error; 84 void *kernelinfo; 85 }; 86 87 /* 88 * I/O control block 89 */ 90 typedef struct aiocb { 91 int aio_fildes; /* File descriptor */ 92 off_t aio_offset; /* File offset for I/O */ 93 volatile void *aio_buf; /* I/O buffer in process space */ 94 size_t aio_nbytes; /* Number of bytes for I/O */ 95 int __spare__[2]; 96 void *__spare2__; 97 int aio_lio_opcode; /* LIO opcode */ 98 int aio_reqprio; /* Request priority -- ignored */ 99 struct __aiocb_private _aiocb_private; 100 struct sigevent aio_sigevent; /* Signal to deliver */ 101 } aiocb_t; 102 103 #ifdef _KERNEL 104 105 typedef void aio_cancel_fn_t(struct kaiocb *); 106 typedef void aio_handle_fn_t(struct kaiocb *); 107 108 /* 109 * Kernel version of an I/O control block. 110 * 111 * Locking key: 112 * * - need not protected 113 * a - locked by kaioinfo lock 114 * b - locked by backend lock 115 * c - locked by aio_job_mtx 116 */ 117 struct kaiocb { 118 TAILQ_ENTRY(kaiocb) list; /* (b) backend-specific list of jobs */ 119 TAILQ_ENTRY(kaiocb) plist; /* (a) lists of pending / done jobs */ 120 TAILQ_ENTRY(kaiocb) allist; /* (a) list of all jobs in proc */ 121 int jobflags; /* (a) job flags */ 122 int inputcharge; /* (*) input blocks */ 123 int outputcharge; /* (*) output blocks */ 124 struct proc *userproc; /* (*) user process */ 125 struct ucred *cred; /* (*) active credential when created */ 126 struct file *fd_file; /* (*) pointer to file structure */ 127 struct aioliojob *lio; /* (*) optional lio job */ 128 struct aiocb *ujob; /* (*) pointer in userspace of aiocb */ 129 struct knlist klist; /* (a) list of knotes */ 130 struct aiocb uaiocb; /* (*) copy of user I/O control block */ 131 ksiginfo_t ksi; /* (a) realtime signal info */ 132 uint64_t seqno; /* (*) job number */ 133 aio_cancel_fn_t *cancel_fn; /* (a) backend cancel function */ 134 aio_handle_fn_t *handle_fn; /* (c) backend handle function */ 135 union { /* Backend-specific data fields */ 136 struct { /* BIO backend */ 137 struct bio *bp; /* (*) BIO pointer */ 138 struct buf *pbuf; /* (*) buffer pointer */ 139 struct vm_page *pages[btoc(MAXPHYS)+1]; /* (*) */ 140 int npages; /* (*) number of pages */ 141 }; 142 struct { /* fsync() requests */ 143 int pending; /* (a) number of pending I/O */ 144 }; 145 struct { 146 void *backend1; 147 void *backend2; 148 long backend3; 149 int backend4; 150 }; 151 }; 152 }; 153 154 struct socket; 155 struct sockbuf; 156 157 /* 158 * AIO backends should permit cancellation of queued requests waiting to 159 * be serviced by installing a cancel routine while the request is 160 * queued. The cancellation routine should dequeue the request if 161 * necessary and cancel it. Care must be used to handle races between 162 * queueing and dequeueing requests and cancellation. 163 * 164 * When queueing a request somewhere such that it can be cancelled, the 165 * caller should: 166 * 167 * 1) Acquire lock that protects the associated queue. 168 * 2) Call aio_set_cancel_function() to install the cancel routine. 169 * 3) If that fails, the request has a pending cancel and should be 170 * cancelled via aio_cancel(). 171 * 4) Queue the request. 172 * 173 * When dequeueing a request to service it or hand it off to somewhere else, 174 * the caller should: 175 * 176 * 1) Acquire the lock that protects the associated queue. 177 * 2) Dequeue the request. 178 * 3) Call aio_clear_cancel_function() to clear the cancel routine. 179 * 4) If that fails, the cancel routine is about to be called. The 180 * caller should ignore the request. 181 * 182 * The cancel routine should: 183 * 184 * 1) Acquire the lock that protects the associated queue. 185 * 2) Call aio_cancel_cleared() to determine if the request is already 186 * dequeued due to a race with dequeueing thread. 187 * 3) If that fails, dequeue the request. 188 * 4) Cancel the request via aio_cancel(). 189 */ 190 191 bool aio_cancel_cleared(struct kaiocb *job); 192 void aio_cancel(struct kaiocb *job); 193 bool aio_clear_cancel_function(struct kaiocb *job); 194 void aio_complete(struct kaiocb *job, long status, int error); 195 void aio_schedule(struct kaiocb *job, aio_handle_fn_t *func); 196 bool aio_set_cancel_function(struct kaiocb *job, aio_cancel_fn_t *func); 197 void aio_switch_vmspace(struct kaiocb *job); 198 199 #else /* !_KERNEL */ 200 201 struct timespec; 202 203 __BEGIN_DECLS 204 /* 205 * Asynchronously read from a file 206 */ 207 int aio_read(struct aiocb *); 208 209 /* 210 * Asynchronously write to file 211 */ 212 int aio_write(struct aiocb *); 213 214 /* 215 * List I/O Asynchronously/synchronously read/write to/from file 216 * "lio_mode" specifies whether or not the I/O is synchronous. 217 * "acb_list" is an array of "nacb_listent" I/O control blocks. 218 * when all I/Os are complete, the optional signal "sig" is sent. 219 */ 220 int lio_listio(int, struct aiocb *__restrict const *__restrict, int, 221 struct sigevent *); 222 223 /* 224 * Get completion status 225 * returns EINPROGRESS until I/O is complete. 226 * this routine does not block. 227 */ 228 int aio_error(const struct aiocb *); 229 230 /* 231 * Finish up I/O, releasing I/O resources and returns the value 232 * that would have been associated with a synchronous I/O request. 233 * This routine must be called once and only once for each 234 * I/O control block who has had I/O associated with it. 235 */ 236 ssize_t aio_return(struct aiocb *); 237 238 /* 239 * Cancel I/O 240 */ 241 int aio_cancel(int, struct aiocb *); 242 243 /* 244 * Suspend until all specified I/O or timeout is complete. 245 */ 246 int aio_suspend(const struct aiocb * const[], int, const struct timespec *); 247 248 /* 249 * Asynchronous mlock 250 */ 251 int aio_mlock(struct aiocb *); 252 253 #ifdef __BSD_VISIBLE 254 ssize_t aio_waitcomplete(struct aiocb **, struct timespec *); 255 #endif 256 257 int aio_fsync(int op, struct aiocb *aiocbp); 258 __END_DECLS 259 260 #endif /* !_KERNEL */ 261 262 #endif /* !_SYS_AIO_H_ */ 263