CVS commit: src/sys

["Michael van Elst" <mlelstv%netbsd.org@localhost>]

Module Name:    src
Committed By:   mlelstv
Date:           Thu Aug 27 05:51:50 UTC 2015

Modified Files:
        src/sys/arch/xen/xen: xbd_xenbus.c
        src/sys/dev: cgd.c dksubr.c dkvar.h ld.c

Log Message:
Make dksubr use a spin-mutex again, since some drivers still call dk_done
from hardware interrupt. Instead, release mutex while calling start routine.

The buffer peek/use/get sequence which can no longer be atomic. So consume
the buffer directly and on error privately save and retry the buffer later.
The dk_drain function is used to flush such a deferred buffer together with
the buffer queue.
Adjust drivers to use dk_drain.

Fix an error path where dk_done was called while the lock was already held.


To generate a diff of this commit:
cvs rdiff -u -r1.72 -r1.73 src/sys/arch/xen/xen/xbd_xenbus.c
cvs rdiff -u -r1.103 -r1.104 src/sys/dev/cgd.c
cvs rdiff -u -r1.73 -r1.74 src/sys/dev/dksubr.c
cvs rdiff -u -r1.21 -r1.22 src/sys/dev/dkvar.h
cvs rdiff -u -r1.91 -r1.92 src/sys/dev/ld.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.