Re: [PATCH v5 7/8] md: sync blockdev before stopping raid or setting readonly

[Li Nan]

在 2024/2/2 10:12, Yu Kuai 写道:
> Hi,
>
> 在 2024/02/01 14:34, linan666@xxxxxxxxxxxxxxx 写道:
> > From: Li Nan <linan122@xxxxxxxxxx>
> >
> > Commit a05b7ea03d72 ("md: avoid crash when stopping md array races
> > with closing other open fds.") added sync_block before stopping raid and
> > setting readonly. Later in commit 260fa034ef7a ("md: avoid deadlock when
> > dirty buffers during md_stop.") it is moved to ioctl. array_state_store()
> > was ignored. Add sync blockdev to array_state_store() now.
>
> You're not just adding sync_blockdev() here. Please rewrite the tittle
> and commit message.
>
> > Signed-off-by: Li Nan <linan122@xxxxxxxxxx>
> > ---
> >   drivers/md/md.c | 16 ++++++++++++++++
> >   1 file changed, 16 insertions(+)
> >
> > diff --git a/drivers/md/md.c b/drivers/md/md.c
> > index 4c7a0225f77d..86becf0015f5 100644
> > --- a/drivers/md/md.c
> > +++ b/drivers/md/md.c
> > @@ -4493,6 +4493,16 @@ array_state_store(struct mddev *mddev, const char 
> > *buf, size_t len)
> >       case broken:        /* cannot be set */
> >       case bad_word:
> >           return -EINVAL;
> > +    case clear:
> > +    case readonly:
> > +    case inactive:
> > +    case read_auto:
> > +        if (!mddev->pers || !md_is_rdwr(mddev))
> > +            break;
> > +        err = mddev_set_closing_and_sync_blockdev(mddev);
>
> In this context, mddev->openers should be zero, and such check is in
> do_md_stop() and md_set_readonly():

Yeah, the checks in do_md_stop() and md_set_readonly() can be removed after
this patch. However, 'mddev->open_metux' is used to protect MD_CLOSING and
'mddev->openers', it can be removed in these functions, too.

I will fix it later. Thanks for your review.

> if (atomic_read(&mddev->openers) > !!bdev).
>
> Thanks,
> Kuai



--
Thanks,
Nan