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From:   harshad shirwadkar <harshadshirwadkar@gmail.com>
Date:   Thu, 10 Mar 2022 20:17:00 -0800
Message-ID: <CAD+ocbyM9HdZwpB_NzKAiJTsZ78gZ_4Hsk3c21tL4ZetapqcFg@mail.gmail.com>
Subject: Re: [PATCH v2 2/5] ext4: for committing inode, make
 ext4_fc_track_inode wait
To:     Jan Kara <jack@suse.cz>
Cc:     Ext4 Developers List <linux-ext4@vger.kernel.org>,
        Ritesh Harjani <riteshh@linux.ibm.com>,
        "Theodore Y. Ts'o" <tytso@mit.edu>
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Thanks for the reviews Jan! I'll update inline.c as you mentioned in
the next version.

- Harshad

On Wed, 9 Mar 2022 at 02:14, Jan Kara <jack@suse.cz> wrote:
>
> On Tue 08-03-22 08:33:16, Harshad Shirwadkar wrote:
> > From: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
> >
> > If the inode that's being requested to track using ext4_fc_track_inode
> > is being committed, then wait until the inode finishes the commit.
> >
> > Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
>
> One comment below...
>
> > --- a/fs/ext4/ext4_jbd2.c
> > +++ b/fs/ext4/ext4_jbd2.c
> > @@ -106,6 +106,18 @@ handle_t *__ext4_journal_start_sb(struct super_block *sb, unsigned int line,
> >                                  GFP_NOFS, type, line);
> >  }
> >
> > +handle_t *__ext4_journal_start(struct inode *inode, unsigned int line,
> > +                               int type, int blocks, int rsv_blocks,
> > +                               int revoke_creds)
> > +{
> > +     handle_t *handle = __ext4_journal_start_sb(inode->i_sb, line,
> > +                                                type, blocks, rsv_blocks,
> > +                                                revoke_creds);
> > +     if (ext4_handle_valid(handle) && !IS_ERR(handle))
> > +             ext4_fc_track_inode(handle, inode);
> > +     return handle;
> > +}
> > +
>
> Please fix fs/ext4/inline.c rather than papering over the problem like
> this. Because it is just a landmine waiting to explode in some strange
> cornercase when someone does not call ext4_journal_start() but other handle
> starting function.
>
>                                                                 Honza
> --
> Jan Kara <jack@suse.com>
> SUSE Labs, CR