md/raid5: prefer replacing failed devices over want-replacement devices.

If a RAID5 has both a failed device and a device marked as
'WantReplacement', then we should preferentially replace the failed
device.
However the current code replaces whichever is found first.
So split into 2 loops, check fail failed/missing first, and only check
for WantReplacement if nothing is failed or missing.

Reported-by: majianpeng <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
This commit is contained in:
NeilBrown 2012-07-03 11:46:53 +10:00
parent fc448a18ae
commit 5cfb22a1f8
1 changed files with 8 additions and 5 deletions

View File

@ -5465,10 +5465,9 @@ static int raid5_add_disk(struct mddev *mddev, struct md_rdev *rdev)
if (rdev->saved_raid_disk >= 0 &&
rdev->saved_raid_disk >= first &&
conf->disks[rdev->saved_raid_disk].rdev == NULL)
disk = rdev->saved_raid_disk;
else
disk = first;
for ( ; disk <= last ; disk++) {
first = rdev->saved_raid_disk;
for (disk = first; disk <= last; disk++) {
p = conf->disks + disk;
if (p->rdev == NULL) {
clear_bit(In_sync, &rdev->flags);
@ -5477,8 +5476,11 @@ static int raid5_add_disk(struct mddev *mddev, struct md_rdev *rdev)
if (rdev->saved_raid_disk != disk)
conf->fullsync = 1;
rcu_assign_pointer(p->rdev, rdev);
break;
goto out;
}
}
for (disk = first; disk <= last; disk++) {
p = conf->disks + disk;
if (test_bit(WantReplacement, &p->rdev->flags) &&
p->replacement == NULL) {
clear_bit(In_sync, &rdev->flags);
@ -5490,6 +5492,7 @@ static int raid5_add_disk(struct mddev *mddev, struct md_rdev *rdev)
break;
}
}
out:
print_raid5_conf(conf);
return err;
}