/*- * SPDX-License-Identifier: BSD-2-Clause * * Copyright (c) 1997 John S. Dyson. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. John S. Dyson's name may not be used to endorse or promote products * derived from this software without specific prior written permission. * * DISCLAIMER: This code isn't warranted to do anything useful. Anything * bad that happens because of using this software isn't the responsibility * of the author. This software is distributed AS-IS. */ #ifndef _SYS_AIO_H_ #define _SYS_AIO_H_ #include <sys/types.h> #include <sys/signal.h> #ifdef _KERNEL #include <sys/queue.h> #include <sys/event.h> #include <sys/signalvar.h> #include <sys/uio.h> #endif /* * Returned by aio_cancel: */ #define AIO_CANCELED 0x1 #define AIO_NOTCANCELED 0x2 #define AIO_ALLDONE 0x3 /* * LIO opcodes */ #define LIO_NOP 0x0 #define LIO_WRITE 0x1 #define LIO_READ 0x2 #if __BSD_VISIBLE #define LIO_VECTORED 0x4 #define LIO_WRITEV (LIO_WRITE | LIO_VECTORED) #define LIO_READV (LIO_READ | LIO_VECTORED) #endif #if defined(_KERNEL) || defined(_WANT_ALL_LIO_OPCODES) #define LIO_SYNC 0x8 #define LIO_DSYNC (0x10 | LIO_SYNC) #define LIO_MLOCK 0x20 #endif #if __BSD_VISIBLE #define LIO_FOFFSET 0x40 #endif /* aio_read2/aio_write2 flags */ #if __BSD_VISIBLE #define AIO_OP2_FOFFSET 0x00000001 #define AIO_OP2_VECTORED 0x00000002 #endif /* * LIO modes */ #define LIO_NOWAIT 0x0 #define LIO_WAIT 0x1 /* * Maximum number of operations in a single lio_listio call */ #define AIO_LISTIO_MAX 16 #ifdef _KERNEL /* Default values of tunables for the AIO worker pool. */ #ifndef MAX_AIO_PROCS #define MAX_AIO_PROCS 32 #endif #ifndef TARGET_AIO_PROCS #define TARGET_AIO_PROCS 4 #endif #ifndef AIOD_LIFETIME_DEFAULT #define AIOD_LIFETIME_DEFAULT (30 * hz) #endif #endif /* * Private members for aiocb -- don't access * directly. */ struct __aiocb_private { long status; long error; void *spare; }; /* * I/O control block */ typedef struct aiocb { int aio_fildes; /* File descriptor */ off_t aio_offset; /* File offset for I/O */ volatile void *aio_buf; /* I/O buffer in process space */ size_t aio_nbytes; /* Number of bytes for I/O */ int __spare__[2]; void *__spare2__; int aio_lio_opcode; /* LIO opcode */ int aio_reqprio; /* Request priority -- ignored */ struct __aiocb_private _aiocb_private; struct sigevent aio_sigevent; /* Signal to deliver */ } aiocb_t; #define aio_iov aio_buf /* I/O scatter/gather list */ #define aio_iovcnt aio_nbytes /* Length of aio_iov */ #ifdef _KERNEL typedef void aio_cancel_fn_t(struct kaiocb *); typedef void aio_handle_fn_t(struct kaiocb *); /* * Kernel version of an I/O control block. * * Locking key: * * - need not protected * a - locked by kaioinfo lock * b - locked by backend lock * c - locked by aio_job_mtx */ struct kaiocb { TAILQ_ENTRY(kaiocb) list; /* (b) backend-specific list of jobs */ TAILQ_ENTRY(kaiocb) plist; /* (a) lists of pending / done jobs */ TAILQ_ENTRY(kaiocb) allist; /* (a) list of all jobs in proc */ int jobflags; /* (a) job flags */ int ioflags; /* (*) io flags */ int inblock; /* (*) input blocks */ int outblock; /* (*) output blocks */ int msgsnd; /* (*) messages sent */ int msgrcv; /* (*) messages received */ struct proc *userproc; /* (*) user process */ struct ucred *cred; /* (*) active credential when created */ struct file *fd_file; /* (*) pointer to file structure */ struct aioliojob *lio; /* (*) optional lio job */ struct aiocb *ujob; /* (*) pointer in userspace of aiocb */ struct knlist klist; /* (a) list of knotes */ struct aiocb uaiocb; /* (*) copy of user I/O control block */ struct uio uio; /* (*) storage for non-vectored uio */ struct iovec iov[1]; /* (*) storage for non-vectored uio */ struct uio *uiop; /* (*) Possibly malloced uio */ ksiginfo_t ksi; /* (a) realtime signal info */ uint64_t seqno; /* (*) job number */ aio_cancel_fn_t *cancel_fn; /* (a) backend cancel function */ aio_handle_fn_t *handle_fn; /* (c) backend handle function */ union { /* Backend-specific data fields */ struct { /* BIO backend */ volatile u_int nbio; /* Number of remaining bios */ int error; /* Worst error of all bios */ long nbytes; /* Bytes completed so far */ }; struct { /* fsync() requests */ int pending; /* (a) number of pending I/O */ }; struct { /* socket backend */ void *backend1; long backend3; int backend4; }; }; }; struct socket; struct sockbuf; /* * AIO backends should permit cancellation of queued requests waiting to * be serviced by installing a cancel routine while the request is * queued. The cancellation routine should dequeue the request if * necessary and cancel it. Care must be used to handle races between * queueing and dequeueing requests and cancellation. * * When queueing a request somewhere such that it can be cancelled, the * caller should: * * 1) Acquire lock that protects the associated queue. * 2) Call aio_set_cancel_function() to install the cancel routine. * 3) If that fails, the request has a pending cancel and should be * cancelled via aio_cancel(). * 4) Queue the request. * * When dequeueing a request to service it or hand it off to somewhere else, * the caller should: * * 1) Acquire the lock that protects the associated queue. * 2) Dequeue the request. * 3) Call aio_clear_cancel_function() to clear the cancel routine. * 4) If that fails, the cancel routine is about to be called. The * caller should ignore the request. * * The cancel routine should: * * 1) Acquire the lock that protects the associated queue. * 2) Call aio_cancel_cleared() to determine if the request is already * dequeued due to a race with dequeueing thread. * 3) If that fails, dequeue the request. * 4) Cancel the request via aio_cancel(). */ bool aio_cancel_cleared(struct kaiocb *job); void aio_cancel(struct kaiocb *job); bool aio_clear_cancel_function(struct kaiocb *job); void aio_complete(struct kaiocb *job, long status, int error); void aio_schedule(struct kaiocb *job, aio_handle_fn_t *func); bool aio_set_cancel_function(struct kaiocb *job, aio_cancel_fn_t *func); void aio_switch_vmspace(struct kaiocb *job); #else /* !_KERNEL */ struct timespec; __BEGIN_DECLS /* * Asynchronously read from a file */ int aio_read(struct aiocb *); #if __BSD_VISIBLE int aio_readv(struct aiocb *); #endif /* * Asynchronously write to file */ int aio_write(struct aiocb *); #if __BSD_VISIBLE int aio_writev(struct aiocb *); #endif /* * List I/O Asynchronously/synchronously read/write to/from file * "lio_mode" specifies whether or not the I/O is synchronous. * "acb_list" is an array of "nacb_listent" I/O control blocks. * when all I/Os are complete, the optional signal "sig" is sent. */ int lio_listio(int, struct aiocb *__restrict const *__restrict, int, struct sigevent *); /* * Get completion status * returns EINPROGRESS until I/O is complete. * this routine does not block. */ int aio_error(const struct aiocb *); /* * Finish up I/O, releasing I/O resources and returns the value * that would have been associated with a synchronous I/O request. * This routine must be called once and only once for each * I/O control block who has had I/O associated with it. */ ssize_t aio_return(struct aiocb *); /* * Cancel I/O */ int aio_cancel(int, struct aiocb *); /* * Suspend until all specified I/O or timeout is complete. */ int aio_suspend(const struct aiocb * const[], int, const struct timespec *); /* * Asynchronous mlock */ int aio_mlock(struct aiocb *); #if __BSD_VISIBLE ssize_t aio_waitcomplete(struct aiocb **, struct timespec *); int aio_read2(struct aiocb *, int); int aio_write2(struct aiocb *, int); #endif int aio_fsync(int op, struct aiocb *aiocbp); __END_DECLS #endif /* !_KERNEL */ #endif /* !_SYS_AIO_H_ */
