Re: [REGRESSION] Cannot start degraded RAID1 array with device with write-mostly flag

[Yu Kuai]

Hi,

在 2024/07/09 4:09, Mateusz Jończyk 写道:
> W dniu 8.07.2024 o 03:54, Yu Kuai pisze:
> > Hi,
> >
> > 在 2024/07/06 22:30, Mateusz Jończyk 写道:
> > > Subject: [RFC PATCH] md/raid1: fill in max_sectors
> > >
> > >
> > >
> > > Not yet fully tested or carefully investigated.
> > >
> > >
> > >
> > > Signed-off-by: Mateusz Jo艅czyk<mat.jonczyk@xxxxx>
> > >
> > >
> > >
> > > ---
> > >
> > >    drivers/md/raid1.c | 1 +
> > >
> > >    1 file changed, 1 insertion(+)
> > >
> > >
> > >
> > > diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
> > >
> > > index 7b8a71ca66dd..82f70a4ce6ed 100644
> > >
> > > --- a/drivers/md/raid1.c
> > >
> > > +++ b/drivers/md/raid1.c
> > >
> > > @@ -680,6 +680,7 @@ static int choose_slow_rdev(struct r1conf *conf, struct r1bio *r1_bio,
> > >
> > >            len = r1_bio->sectors;
> > >
> > >            read_len = raid1_check_read_range(rdev, this_sector, &len);
> > >
> > >            if (read_len == r1_bio->sectors) {
> > >
> > > +            *max_sectors = read_len;
> > >
> > >                update_read_sectors(conf, disk, this_sector, read_len);
> > >
> > >                return disk;
> > >
> > >            }
> >
> > This looks correct, can you give it a test and cook a patch?
> >
> > Thanks,
> > Kuai
> Hello,
>
> Yes, I'm working on it. Patch description is nearly done.
> Kernel with this patch works well with normal usage and
> fsstress, except when modifying the array, as I have written
> in my previous email. Will test some more.

Please run mdadm tests at least. And we may need to add a new test.

https://kernel.googlesource.com/pub/scm/utils/mdadm/mdadm.git

./test --dev=loop

Thanks,
Kuai

> I'm feeling nervous working on such sensitive code as md, though.
> I'm not an experienced kernel dev.
>
> Greetings,
>
> Mateusz
>
> .