md/raid1: fix bug in read_balance introduced by hot-replace

When we added hot_replace we doubled the number of devices
that could be in a RAID1 array.  So we doubled how far read_balance
would search.  Unfortunately we didn't double the point at which
it looped back to the beginning - so it effectively loops over
all non-replacement disks twice.
This doesn't cause bad behaviour, but it pointless and means we
never read from replacement devices.

Signed-off-by: NeilBrown <neilb@suse.de>
This commit is contained in:
NeilBrown 2012-07-03 15:58:42 +10:00
parent fab363b5ff
commit 32644afd89

View File

@ -517,8 +517,8 @@ static int read_balance(struct r1conf *conf, struct r1bio *r1_bio, int *max_sect
int bad_sectors;
int disk = start_disk + i;
if (disk >= conf->raid_disks)
disk -= conf->raid_disks;
if (disk >= conf->raid_disks * 2)
disk -= conf->raid_disks * 2;
rdev = rcu_dereference(conf->mirrors[disk].rdev);
if (r1_bio->bios[disk] == IO_BLOCKED