Re: [libvirt] [PATCH 2/2]: Call udevsettle in the appropriate places
Alan Pevec wrote:
On Thu, Nov 27, 2008 at 8:53 AM, Chris Lalancette
<clalance(a)redhat.com
<mailto:clalance@redhat.com>> wrote:
Right, both points make sense. I think the following patch should
address it; I
only conditionally set the UDEVADM variable if I find it. So, for
machines
without it, the meat of virStorageBackendWaitForDevices is compiled
out. In
places where I've found it on the build machine, I then do "access"
for
executable at runtime, and only if that succeeds do I run it. Does
that seem
correct? In addition, based on the comment from Guido, I changed it
over to use
"udevadm settle" instead of "udevsettle".
Please make it try both: RHEL5 has an ancient udev095 and doesn't have
udevadm but it does have udevsettle
Sigh. Silly older distros :). Thanks for the heads up, though, good to know it
now rather than later. Unfortunately, it's not so easy to make it try both; we
would get into a twisty passage of #ifdef's, I think. Dan, what do you think of
the attached patch for older udev compatibility?
--
Chris Lalancette
Index: configure.in
===================================================================
RCS file: /data/cvs/libvirt/configure.in,v
retrieving revision 1.188
diff -u -r1.188 configure.in
--- configure.in 28 Nov 2008 07:50:20 -0000 1.188
+++ configure.in 28 Nov 2008 14:50:11 -0000
@@ -117,6 +117,8 @@
[/sbin:/usr/sbin:/usr/local/sbin:$PATH])
AC_PATH_PROG([UDEVADM], [udevadm], [],
[/sbin:/usr/sbin:/usr/local/sbin:$PATH])
+AC_PATH_PROG([UDEVSETTLE], [udevsettle], [],
+ [/sbin:/usr/sbin:/usr/local/sbin:$PATH])
AC_DEFINE_UNQUOTED([DNSMASQ],["$DNSMASQ"],
[Location or name of the dnsmasq program])
@@ -126,6 +128,10 @@
AC_DEFINE_UNQUOTED([UDEVADM],["$UDEVADM"],
[Location or name of the udevadm program])
fi
+if test -n "$UDEVSETTLE"; then
+ AC_DEFINE_UNQUOTED([UDEVSETTLE],["$UDEVSETTLE"],
+ [Location or name of the udevsettle program])
+fi
dnl Specific dir for HTML output ?
AC_ARG_WITH([html-dir], [AC_HELP_STRING([--with-html-dir=path],
Index: src/storage_backend.c
===================================================================
RCS file: /data/cvs/libvirt/src/storage_backend.c,v
retrieving revision 1.31
diff -u -r1.31 storage_backend.c
--- src/storage_backend.c 28 Nov 2008 07:50:20 -0000 1.31
+++ src/storage_backend.c 28 Nov 2008 14:50:11 -0000
@@ -287,6 +287,23 @@
*/
virRun(conn, settleprog, &exitstatus);
}
+#elif defined(UDEVSETTLE)
+void virStorageBackendWaitForDevices(virConnectPtr conn)
+{
+ const char *const settleprog[] = { UDEVSETTLE, NULL };
+ int exitstatus;
+
+ if (access(UDEVSETTLE, X_OK) != 0)
+ return;
+
+ /*
+ * NOTE: we ignore errors here; this is just to make sure that any device
+ * nodes that are being created finish before we try to scan them.
+ * If this fails for any reason, we still have the backup of polling for
+ * 5 seconds for device nodes.
+ */
+ virRun(conn, settleprog, &exitstatus);
+}
#else
void virStorageBackendWaitForDevices(virConnectPtr conn ATTRIBUTE_UNUSED) {}
#endif