[PATCH] md: allow dirty raid[456] arrays to be started at boot

See patch to md.txt for more details

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 8175a2a..b4fb724 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -1937,6 +1937,7 @@
 	md_wakeup_thread(mddev->thread);
 }
 
+static int start_dirty_degraded;
 
 static int do_md_run(mddev_t * mddev)
 {
@@ -2048,6 +2049,7 @@
 	mddev->recovery = 0;
 	mddev->resync_max_sectors = mddev->size << 1; /* may be over-ridden by personality */
 	mddev->barriers_work = 1;
+	mddev->ok_start_degraded = start_dirty_degraded;
 
 	if (start_readonly)
 		mddev->ro = 2; /* read-only, but switch on first write */
@@ -4509,6 +4511,8 @@
 }
 
 module_param_call(start_ro, set_ro, get_ro, NULL, 0600);
+module_param(start_dirty_degraded, int, 0644);
+
 
 EXPORT_SYMBOL(register_md_personality);
 EXPORT_SYMBOL(unregister_md_personality);