Re: [PATCH RESEND] md: allow to set the fail_fast on RAID1/RAID10

[Xiao Ni]

On Mon, Oct 11, 2021 at 5:42 PM Li Feng <fengli@xxxxxxxxxx> wrote:
>
> Xiao Ni <xni@xxxxxxxxxx> 于2021年10月11日周一 下午3:49写道：
> >
> > Hi all
> >
> > Now the per device sysfs interface file state can change failfast. Do
> > we need a new file for failfast?
> >
> > I did a test. The steps are:
> >
> > mdadm -CR /dev/md0 -l1 -n2 /dev/sdb /dev/sdc --assume-clean
> > cd /sys/block/md0/md/dev-sdb
> > echo failfast > state
> > cat state
> > in_sync,failfast
>
> This works,  will it be persisted to disk?
>

mdadm --detail /dev/md0 can show the failfast information. So it
should be written in superblock.
But I don't find how md does this. I'm looking at this.

Regards
Xiao