Commit d595567d authored Oct 01, 2018 by Shaohua Li

MD: fix invalid stored role for a disk

If we change the number of array's device after device is removed from array,
then add the device back to array, we can see that device is added as active
role instead of spare which we expected.

Please see the below link for details:
https://marc.info/?l=linux-raid&m=153736982015076&w=2



This is caused by that we prefer to use device's previous role which is
recorded by saved_raid_disk, but we should respect the new number of
conf->raid_disks since it could be changed after device is removed.

Reported-by: Gioh Kim <gi-oh.kim@profitbricks.com>
Tested-by: Gioh Kim <gi-oh.kim@profitbricks.com>
Acked-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>

parent ee37d731

drivers/md/md.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -1774,6 +1774,10 @@ static int super_1_validate(struct mddev mddev, struct md_rdev rdev)
		} else
		set_bit(In_sync, &rdev->flags);
		rdev->raid_disk = role;
		if (role >= mddev->raid_disks) {
		rdev->saved_raid_disk = -1;
		rdev->raid_disk = -1;
		}
		break;
		}
		if (sb->devflags & WriteMostly1)

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