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References: <20210201000606.2206740-1-daeho43@gmail.com> <7e2f440e-6500-04c8-1115-880754a18efa@kernel.org>
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From:   Daeho Jeong <daeho43@gmail.com>
Date:   Mon, 1 Feb 2021 22:11:18 +0900
Message-ID: <CACOAw_zW+xnN7pBmTknuJ1=CGiAvVq0sQhe7D6X8sOjgjF_qeg@mail.gmail.com>
Subject: Re: [f2fs-dev] [PATCH] f2fs: fix checkpoint mount option wrong combination
To:     Chao Yu <chao@kernel.org>
Cc:     linux-kernel@vger.kernel.org,
        linux-f2fs-devel@lists.sourceforge.net, kernel-team@android.com,
        Daeho Jeong <daehojeong@google.com>
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Actually, I think we need to select one among them, disable, enable
and merge. I realized my previous understanding about that was wrong.
In that case of "checkpoint=3Dmerge,checkpoint=3Denable", the last option
will override the ones before that.
This is how the other mount options like fsync_mode, whint_mode and etc.
So, the answer will be "checkpoint=3Denable". What do you think?


2021=EB=85=84 2=EC=9B=94 1=EC=9D=BC (=EC=9B=94) =EC=98=A4=ED=9B=84 9:40, Ch=
ao Yu <chao@kernel.org>=EB=8B=98=EC=9D=B4 =EC=9E=91=EC=84=B1:
>
> On 2021/2/1 8:06, Daeho Jeong wrote:
> > From: Daeho Jeong <daehojeong@google.com>
> >
> > As checkpoint=3Dmerge comes in, mount option setting related to
> > checkpoint had been mixed up. Fixed it.
> >
> > Signed-off-by: Daeho Jeong <daehojeong@google.com>
> > ---
> >   fs/f2fs/super.c | 11 +++++------
> >   1 file changed, 5 insertions(+), 6 deletions(-)
> >
> > diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> > index 56696f6cfa86..8231c888c772 100644
> > --- a/fs/f2fs/super.c
> > +++ b/fs/f2fs/super.c
> > @@ -930,20 +930,25 @@ static int parse_options(struct super_block *sb, =
char *options, bool is_remount)
> >                               return -EINVAL;
> >                       F2FS_OPTION(sbi).unusable_cap_perc =3D arg;
> >                       set_opt(sbi, DISABLE_CHECKPOINT);
> > +                     clear_opt(sbi, MERGE_CHECKPOINT);
> >                       break;
> >               case Opt_checkpoint_disable_cap:
> >                       if (args->from && match_int(args, &arg))
> >                               return -EINVAL;
> >                       F2FS_OPTION(sbi).unusable_cap =3D arg;
> >                       set_opt(sbi, DISABLE_CHECKPOINT);
> > +                     clear_opt(sbi, MERGE_CHECKPOINT);
> >                       break;
> >               case Opt_checkpoint_disable:
> >                       set_opt(sbi, DISABLE_CHECKPOINT);
> > +                     clear_opt(sbi, MERGE_CHECKPOINT);
> >                       break;
> >               case Opt_checkpoint_enable:
> >                       clear_opt(sbi, DISABLE_CHECKPOINT);
> > +                     clear_opt(sbi, MERGE_CHECKPOINT);
>
> What if: -o checkpoint=3Dmerge,checkpoint=3Denable
>
> Can you please explain the rule of merge/disable/enable combination and t=
heir
> result? e.g.
> checkpoint=3Dmerge,checkpoint=3Denable
> checkpoint=3Denable,checkpoint=3Dmerge
> checkpoint=3Dmerge,checkpoint=3Ddisable
> checkpoint=3Ddisable,checkpoint=3Dmerge
>
> If the rule/result is clear, it should be documented.
>
> Thanks,
>
>
> >                       break;
> >               case Opt_checkpoint_merge:
> > +                     clear_opt(sbi, DISABLE_CHECKPOINT);
> >                       set_opt(sbi, MERGE_CHECKPOINT);
> >                       break;
> >   #ifdef CONFIG_F2FS_FS_COMPRESSION
> > @@ -1142,12 +1147,6 @@ static int parse_options(struct super_block *sb,=
 char *options, bool is_remount)
> >               return -EINVAL;
> >       }
> >
> > -     if (test_opt(sbi, DISABLE_CHECKPOINT) &&
> > -                     test_opt(sbi, MERGE_CHECKPOINT)) {
> > -             f2fs_err(sbi, "checkpoint=3Dmerge cannot be used with che=
ckpoint=3Ddisable\n");
> > -             return -EINVAL;
> > -     }
> > -
> >       /* Not pass down write hints if the number of active logs is less=
er
> >        * than NR_CURSEG_PERSIST_TYPE.
> >        */
> >