Re: [PATCH 1/2] HFSPlus: clear dirty flags on remount read-only

[Vyacheslav Dubeyko <slava@dubeyko.com>]

Hi Timo,

On Sun, 2015-11-29 at 15:59 +0100, Timo Schlüßler wrote:
> Remounting a HFSPlus filesystem read-only doesn't clear the "DIRTY"-flags
> (not HFSPLUS_VOL_UNMNT and HFSPLUS_VOL_INCNSTNT) correctly. Subsequent
> mounts then report a dirty filesystem and enforce a check before willing
> to mount it read-write again.
> Signed-off-by: Timo Schlüßler <timo@schluessler.org>
> ---
> 
> --- linux/fs/hfsplus/super.c.orig       2015-11-22 20:11:25.000000000 +0100
> +++ linux/fs/hfsplus/super.c    2015-11-22 20:14:38.000000000 +0100
> @@ -325,11 +325,12 @@ static int hfsplus_statfs(struct dentry
> 
>  static int hfsplus_remount(struct super_block *sb, int *flags, char *data)
>  {
> +       struct hfsplus_vh *vhdr = HFSPLUS_SB(sb)->s_vhdr;
> +
>         sync_filesystem(sb);
>         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
>                 return 0;
>         if (!(*flags & MS_RDONLY)) {
> -               struct hfsplus_vh *vhdr = HFSPLUS_SB(sb)->s_vhdr;
>                 int force = 0;
> 
>                 if (!hfsplus_parse_options_remount(data, &force))
> @@ -352,6 +353,12 @@ static int hfsplus_remount(struct super_
>                         sb->s_flags |= MS_RDONLY;
>                         *flags |= MS_RDONLY;
>                 }
> +       } else {
> +               vhdr->modify_date = hfsp_now2mt();
> +               vhdr->attributes |= cpu_to_be32(HFSPLUS_VOL_UNMNT);
> +               vhdr->attributes &= cpu_to_be32(~HFSPLUS_VOL_INCNSTNT);

If you set HFSPLUS_VOL_UNMNT and clear HFSPLUS_VOL_INCNSTNT bits on
operation of remount in READ-ONLY state then you should do opposite
operation on remount in READ-WRITE state. But, as far as I can judge,
you've missed this change. Such modification should be in the same
patch.

> +
> +               hfsplus_sync_fs(sb, 1);

Are you sure that hfsplus_sync_fs() should be called here? As far as I
can see, sync_filesystem() does it for you. What the reason for second
call? Or do I miss something?

Thanks,
Vyacheslav Dubeyko.