svn commit: r233791 - stable/8/sys/dev/xen/blkfront
Justin T. Gibbs
gibbs at FreeBSD.org
Mon Apr 2 16:50:49 UTC 2012
Author: gibbs
Date: Mon Apr 2 16:50:48 2012
New Revision: 233791
URL: http://svn.freebsd.org/changeset/base/233791
Log:
MFC Revision 233465
Correct failure to attach the PV block front device on Citrix
XenServer configurations that advertise the multi-page ring extension,
but only allow a single page of ring space.
sys/dev/xen/blkfront/blkfront.c:
If only one page of ring space is being used, do not publish
in the XenStore the number of pages in use (1), via either
of the supported multi-page ring extension schemes.
Single page operation is the same with or without the
ring-page extension being negotiated. Relying on the
legacy behavior avoids an incompatible difference in how
the two ring-page extension schemes that are out in the
wild deal with the base case of a single page. The
Amazon/Red Hat drivers use the same XenStore variable as
if the extension was not negotiated. The Citrix drivers
assume the new ring reference XenStore variables will be
available.
Reported by: Oliver Schonefeld <schonefeld at ids-mannheim.de>
Modified:
stable/8/sys/dev/xen/blkfront/blkfront.c
Directory Properties:
stable/8/sys/ (props changed)
Modified: stable/8/sys/dev/xen/blkfront/blkfront.c
==============================================================================
--- stable/8/sys/dev/xen/blkfront/blkfront.c Mon Apr 2 16:37:46 2012 (r233790)
+++ stable/8/sys/dev/xen/blkfront/blkfront.c Mon Apr 2 16:50:48 2012 (r233791)
@@ -698,21 +698,25 @@ blkfront_initialize(struct xb_softc *sc)
return;
/* Support both backend schemes for relaying ring page limits. */
- error = xs_printf(XST_NIL, node_path,
- "num-ring-pages","%u", sc->ring_pages);
- if (error) {
- xenbus_dev_fatal(sc->xb_dev, error,
- "writing %s/num-ring-pages",
- node_path);
- return;
- }
- error = xs_printf(XST_NIL, node_path,
- "ring-page-order","%u", fls(sc->ring_pages) - 1);
- if (error) {
- xenbus_dev_fatal(sc->xb_dev, error,
- "writing %s/ring-page-order",
- node_path);
- return;
+ if (sc->ring_pages > 1) {
+ error = xs_printf(XST_NIL, node_path,
+ "num-ring-pages","%u", sc->ring_pages);
+ if (error) {
+ xenbus_dev_fatal(sc->xb_dev, error,
+ "writing %s/num-ring-pages",
+ node_path);
+ return;
+ }
+
+ error = xs_printf(XST_NIL, node_path,
+ "ring-page-order", "%u",
+ fls(sc->ring_pages) - 1);
+ if (error) {
+ xenbus_dev_fatal(sc->xb_dev, error,
+ "writing %s/ring-page-order",
+ node_path);
+ return;
+ }
}
error = xs_printf(XST_NIL, node_path,
More information about the svn-src-stable
mailing list