From 7ec0547838976d088dfb9cb0adb073e6e8a15aa3 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Tue, 31 Mar 2009 15:10:36 +1100 Subject: md/raid5: enhance raid5_size to work correctly with negative delta_disks This is the first of four patches which combine to allow md/raid5 to reduce the number of devices in the array by restriping the data over a subset of the devices. If the number of disks in a raid4/5/6 is being reduced, then the default size must be based on the new number, not the old number of devices. In general, it should be based on the smaller of new and old. Signed-off-by: NeilBrown --- drivers/md/raid5.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) (limited to 'drivers/md') diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 3930b3e9aa04..5694eb8941b6 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -4169,8 +4169,13 @@ raid5_size(mddev_t *mddev, sector_t sectors, int raid_disks) if (!sectors) sectors = mddev->dev_sectors; - if (!raid_disks) - raid_disks = conf->previous_raid_disks; + if (!raid_disks) { + /* size is defined by the smallest of previous and new size */ + if (conf->raid_disks < conf->previous_raid_disks) + raid_disks = conf->raid_disks; + else + raid_disks = conf->previous_raid_disks; + } sectors &= ~((sector_t)mddev->chunk_size/512 - 1); return sectors * (raid_disks - conf->max_degraded); -- cgit v1.2.3