[src/trunk]: src/share/man/man9 Note reusing bufs requires clearing BO_DONE.

[riastradh <riastradh%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/6e96fc72b27c
branches:  trunk
changeset: 337022:6e96fc72b27c
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Mon Mar 30 13:17:14 2015 +0000

description:
Note reusing bufs requires clearing BO_DONE.

diffstat:

 share/man/man9/bufferio.9 |  10 +++++++++-
 1 files changed, 9 insertions(+), 1 deletions(-)

diffs (24 lines):

diff -r 872f0f95d501 -r 6e96fc72b27c share/man/man9/bufferio.9
--- a/share/man/man9/bufferio.9 Mon Mar 30 13:10:04 2015 +0000
+++ b/share/man/man9/bufferio.9 Mon Mar 30 13:17:14 2015 +0000
@@ -1,4 +1,4 @@
-.\"    $NetBSD: bufferio.9,v 1.6 2015/03/30 13:10:04 riastradh Exp $
+.\"    $NetBSD: bufferio.9,v 1.7 2015/03/30 13:17:14 riastradh Exp $
 .\"
 .\" Copyright (c) 2015 The NetBSD Foundation, Inc.
 .\" All rights reserved.
@@ -165,6 +165,14 @@
 with
 .Fn biowait bp .
 .El
+.Pp
+Once an I/O transfer has completed, its
+.Li struct buf
+may be reused, but the user must first clear the
+.Dv BO_DONE
+flag of
+.Fa bp Ns Li "->b_oflags"
+before reusing it.
 .Sh NESTED I/O TRANSFERS
 Sometimes an I/O transfer from a single buffer in memory cannot go to a
 single location on a block device: it must be split up into smaller