freebsd-skq/share/man/man9/VOP_STRATEGY.9
trasz b2515a861b According to phk@, VOP_STRATEGY should never, _ever_, return
anything other than 0.  Make it so.  This fixes
"panic: VOP_STRATEGY failed bp=0xc320dd90 vp=0xc3b9f648",
encountered when writing to an orphaned filesystem.  Reason
for the panic was the following assert:
KASSERT(i == 0, ("VOP_STRATEGY failed bp=%p vp=%p", bp, bp->b_vp));
at vfs_bio:bufstrategy().

Reviewed by:	scottl, phk
Approved by:	rwatson (mentor)
Sponsored by:	FreeBSD Foundation
2008-12-16 21:13:11 +00:00

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Groff

.\" -*- nroff -*-
.\"
.\" Copyright (c) 1996 Doug Rabson
.\"
.\" All rights reserved.
.\"
.\" This program is free software.
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.\" $FreeBSD$
.\"
.Dd July 24, 1996
.Os
.Dt VOP_STRATEGY 9
.Sh NAME
.Nm VOP_STRATEGY
.Nd read or write a file system buffer
.Sh SYNOPSIS
.In sys/param.h
.In sys/vnode.h
.Ft int
.Fn VOP_STRATEGY "struct vnode *vp" "struct buf *bp"
.Sh DESCRIPTION
The arguments are:
.Bl -tag -width 2n
.It Fa vp
The vnode that the buffer is for.
.It Fa bp
The buffer to be read or written.
.El
.Pp
This call either reads or writes data from a file, depending on the value of
.Fa bp->b_io.bio_cmd .
.Pp
The call may block.
.Sh RETURN VALUES
Always zero.
Errors should be signalled by setting BIO_ERROR on b_ioflags field in struct buf,
and setting b_error to the appropriate errno value.
.Sh SEE ALSO
.\" .Xr buf 9 ,
.Xr vnode 9
.Sh AUTHORS
This manual page was written by
.An Doug Rabson .