Re: [PATCH 08/12] ext4: Combine ext4_handle_error() and save_error_info()

From: Jan Kara <jack@suse.cz>
To: harshad shirwadkar <harshadshirwadkar@gmail.com>
Cc: Jan Kara <jack@suse.cz>, Ted Tso <tytso@mit.edu>,
	Ext4 Developers List <linux-ext4@vger.kernel.org>
Subject: Re: [PATCH 08/12] ext4: Combine ext4_handle_error() and save_error_info()
Date: Wed, 16 Dec 2020 11:11:47 +0100	[thread overview]
Message-ID: <20201216101147.GB21258@quack2.suse.cz> (raw)
In-Reply-To: <CAD+ocbwLVsjrB1HRsOm-mD6zm+1Et1C5FcwcGvNmt-AkuZo4Uw@mail.gmail.com>

On Mon 14-12-20 11:23:04, harshad shirwadkar wrote:
> On Fri, Nov 27, 2020 at 3:38 AM Jan Kara <jack@suse.cz> wrote:
> >
> > save_error_info() is always called together with ext4_handle_error().
> > Combine them into a single call and move unconditional bits out of
> > save_error_info() into ext4_handle_error().
> >
> > Signed-off-by: Jan Kara <jack@suse.cz>
> > ---
> >  fs/ext4/super.c | 31 +++++++++++++++----------------
> >  1 file changed, 15 insertions(+), 16 deletions(-)
> >
> > diff --git a/fs/ext4/super.c b/fs/ext4/super.c
> > index 2d7dc0908cdd..73a09b73fc11 100644
> > --- a/fs/ext4/super.c
> > +++ b/fs/ext4/super.c
> > @@ -592,9 +592,6 @@ static void __save_error_info(struct super_block *sb, int error,
> >  {
> >         struct ext4_sb_info *sbi = EXT4_SB(sb);
> >
> > -       EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
> > -       if (bdev_read_only(sb->s_bdev))
> > -               return;
> >         /* We default to EFSCORRUPTED error... */
> >         if (error == 0)
> >                 error = EFSCORRUPTED;

...

> > @@ -944,13 +943,13 @@ __acquires(bitlock)
> >         if (test_opt(sb, ERRORS_CONT)) {
> >                 if (test_opt(sb, WARN_ON_ERROR))
> >                         WARN_ON_ONCE(1);
> > +               EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
> Since you moved the bdev_read_only() check from __save_error_info to
> ext4_handle_error(), should we add that check here?

Thanks for the review! Now that I'm looking at it, you're probably right it
would be safer.  That being said I don't think it really matters:
a) Because I don't think this function can get called on read-only bdev
b) Because functions processing the work item will find out the sb is
   read-only and won't do anything. But it's really wasted work.

I can see Ted didn't merge this patch yet. So I'll resend the series from
this patch because after fixing this it required a bit of rebasing. Also I
have two more additional fixes in the series based on Andreas' feedback.

Thanks again for looking into the series!

								Honza
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR