CVS commit: [netbsd-5] src/sys/arch/xen/xen

["Jeff Rizzo" <riz%netbsd.org@localhost>]

Module Name:    src
Committed By:   riz
Date:           Fri Aug 12 20:48:48 UTC 2011

Modified Files:
        src/sys/arch/xen/xen [netbsd-5]: xbdback_xenbus.c

Log Message:
Pull up following revision(s) (requested by bouyer in ticket #1654):
        sys/arch/xen/xen/xbdback_xenbus.c: revision 1.42
        sys/arch/xen/xen/xbdback_xenbus.c: revision 1.43
        sys/arch/xen/xen/xbdback_xenbus.c: revision 1.44
Make sure to call xbdback_trampoline() at splbio()
Several fixes to the continuation engine:
- make sure to enter the continuation loop at splbio(), and add some
  KASSERT() for this.
- When a flush operation is enqueued to the workqueue, make sure the
  continuation loop can't be restarted by a previous workqueue
  completion or an event. We can't restart it at this point because
  the flush even is still recorded as the current I/O.
  For this add a xbdback_co_cache_doflush_wait() which acts as a noop;
  the workqueue callback will restart the loop once the flush is complete.
Should fix "kernel diagnostic assertion xbd_io->xio_mapped == 0" panics
reported by Jeff Rizzo on port-xen@.
Add a comment explaing why a flush workqueue is handled differently from
read/write workqueue requests.


To generate a diff of this commit:
cvs rdiff -u -r1.20.4.5 -r1.20.4.6 src/sys/arch/xen/xen/xbdback_xenbus.c

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