Commit d6b212f4 authored Jun 08, 2011 by Jonathan Brassow Committed by NeilBrown Jun 09, 2011

MD: raid5 do not set fullsync



Add check to determine if a device needs full resync or if partial resync will do

RAID 5 was assuming that if a device was not In_sync, it must undergo a full
resync.  We add a check to see if 'saved_raid_disk' is the same as 'raid_disk'.
If it is, we can safely skip the full resync and rely on the bitmap for
partial recovery instead.  This is the legitimate purpose of 'saved_raid_disk',
from md.h:
int saved_raid_disk;            /* role that device used to have in the
                                 * array and could again if we did a partial
                                 * resync from the bitmap
                                 */

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>

parent 9c81075f

drivers/md/raid5.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -4858,7 +4858,7 @@ static raid5_conf_t setup_conf(mddev_t mddev)
		printk(KERN_INFO "md/raid:%s: device %s operational as raid"
		" disk %d\n",
		mdname(mddev), bdevname(rdev->bdev, b), raid_disk);
		} else
		} else if (rdev->saved_raid_disk != raid_disk)
		/* Cannot rely on bitmap to complete recovery */
		conf->fullsync = 1;
		}