Re: [PATCH v2 1/3] md: Don't clear MD_CLOSING when the raid is about to stop

[Li Nan]

在 2024/1/18 15:35, Mariusz Tkaczyk 写道:
> On Wed, 17 Jan 2024 17:37:05 +0800
> linan666@xxxxxxxxxxxxxxx wrote:
>
> > From: Li Nan <linan122@xxxxxxxxxx>
> >
> > The raid should not be opened anymore when it is about to be stopped.
> > However, other processes can open it again if the flag MD_CLOSING is
> > cleared before exiting. From now on, this flag will not be cleared when
> > the raid will be stopped.
> >
> > Fixes: 065e519e71b2 ("md: MD_CLOSING needs to be cleared after called
> > md_set_readonly or do_md_stop") Signed-off-by: Li Nan <linan122@xxxxxxxxxx>
> > ---
> >   drivers/md/md.c | 16 +++++++++++++++-
> >   1 file changed, 15 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/md/md.c b/drivers/md/md.c
> > index 9bdd57324c37..4bf821b89415 100644
> > --- a/drivers/md/md.c
> > +++ b/drivers/md/md.c
> > @@ -6254,7 +6254,15 @@ static void md_clean(struct mddev *mddev)
> >   	mddev->persistent = 0;
> >   	mddev->level = LEVEL_NONE;
> >   	mddev->clevel[0] = 0;
> > -	mddev->flags = 0;
> > +	/*
> > +	 * Don't clear MD_CLOSING, or mddev can be opened again.
> > +	 * 'hold_active != 0' means mddev is still in the creation
> > +	 * process and will be used later.
> > +	 */
> > +	if (mddev->hold_active)
> > +		mddev->flags = 0;
> > +	else
> > +		mddev->flags &= BIT_ULL_MASK(MD_CLOSING);
> >   	mddev->sb_flags = 0;
> >   	mddev->ro = MD_RDWR;
> >   	mddev->metadata_type[0] = 0;
> > @@ -7728,6 +7736,12 @@ static int md_ioctl(struct block_device *bdev,
> > blk_mode_t mode,
> >   	case STOP_ARRAY:
> >   		err = do_md_stop(mddev, 0, bdev);
> > +		if (!err)
> > +			/*
> > +			 * mddev has been stopped, keep flag the
> > +			 * MD_CLOSING to prevent reuse.
> > +			 */
> > +			did_set_md_closing = false;
>
> Hello Nan,
> The meaning of the "did_set_md_closing" is to notify that MD_CLOSING was set in
> this function, to know how to behave on error.
> You gave it another meaning "Do not clear MD_CLOSING because we want it to stay"
> Please consider how to solve this confusion. I see the comment you added but I
> think we can have this solved better, maybe just name it as "clear_md_closing"?

Thanks for your review, I will rename it in next version.

> Anyway it looks acceptable to me:
> Acked-by: Mariusz Tkaczyk <mariusz.tkaczyk@xxxxxxxxxxxxxxx>
>
> Thanks,
> Mariusz
>
> .

--
Thanks,
Nan