From: Jonathan Brassow <jbrassow@redhat.com>
Subject: [PATCH RHEL 5.1] bz 236624 - dm-raid1.c: rh_in_sync should be 	allowed to block
Date: Tue, 08 May 2007 13:28:35 -0500
Bugzilla: 236624
Message-Id: <1178648915.10582.29.camel@hydrogen.msp.redhat.com>
Changelog: [md] rh_in_sync should be allowed to block


 brassow

RHEL5

Bug 236624: dm-mirror: Call to rh_in_sync should be allowed...

When checking the sync status of a region, there are times when we must not
block.  Like when we are attempting to map I/O for the first time or in a
context that must not block.

do_reads operates in a separate kernel thread and should be allowed to block.

In 2.6.21-mm1 as agk-dm-dm-raid1-switch-rh_in_sync-to-blocking-in-do_reads.patch

Index: linux-rhel5/drivers/md/dm-raid1.c
===================================================================
--- linux-rhel5.orig/drivers/md/dm-raid1.c
+++ linux-rhel5/drivers/md/dm-raid1.c
@@ -977,7 +977,7 @@ static void do_reads(struct mirror_set *
 		 * We can only read balance if the region is in sync.
 		 */
 		if (likely(rh_in_sync(&ms->rh,
-				      bio_to_region(&ms->rh, bio), 0)))
+				      bio_to_region(&ms->rh, bio), 1)))
 			m = choose_mirror(ms);
 		else {
 			m = ms->default_mirror;