1.\" -*- nroff -*- 2.\" 3.\" Copyright (c) 1996 Doug Rabson 4.\" 5.\" All rights reserved. 6.\" 7.\" This program is free software. 8.\" 9.\" Redistribution and use in source and binary forms, with or without 10.\" modification, are permitted provided that the following conditions 11.\" are met: 12.\" 1. Redistributions of source code must retain the above copyright 13.\" notice, this list of conditions and the following disclaimer. 14.\" 2. Redistributions in binary form must reproduce the above copyright 15.\" notice, this list of conditions and the following disclaimer in the 16.\" documentation and/or other materials provided with the distribution. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY EXPRESS OR 19.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 20.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 21.\" IN NO EVENT SHALL THE DEVELOPERS BE LIABLE FOR ANY DIRECT, INDIRECT, 22.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 23.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 27.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28.\" 29.\" $FreeBSD$ 30.\" 31.Dd June 30, 2022 32.Dt VOP_STRATEGY 9 33.Os 34.Sh NAME 35.Nm VOP_STRATEGY 36.Nd read or write a file system buffer 37.Sh SYNOPSIS 38.In sys/param.h 39.In sys/buf.h 40.In sys/vnode.h 41.Ft int 42.Fn VOP_STRATEGY "struct vnode *vp" "struct buf *bp" 43.Sh DESCRIPTION 44The arguments are: 45.Bl -tag -width 2n 46.It Fa vp 47The vnode that the buffer is for. 48.It Fa bp 49The buffer to be read or written. 50.El 51.Pp 52This call either reads or writes data from a file, depending on the value of 53.Fa bp->b_iocmd . 54.Pp 55The call may block. 56.Sh RETURN VALUES 57Always zero. 58Errors should be signalled by setting the 59.Dv BIO_ERROR 60bit in 61.Fa bp->b_ioflags 62and setting 63.Fa bp->b_error 64to the appropriate 65.Va errno 66value. 67.Sh SEE ALSO 68.Xr errno 2 , 69.Xr buf 9 , 70.Xr vnode 9 71.Sh AUTHORS 72This manual page was written by 73.An Doug Rabson . 74