Re: [PATCH] ubifs: switch_gc_head: remove redondant sync of wbuf

[Richard Weinberger <richard@nod.at>]

Am 23.06.2016 um 07:53 schrieb Sylvain Etienne:
> The wbuf is already sync-ed before ubifs_leb_unmap()
> 
> Signed-off-by: Sylvain Etienne <seti@dadboo.eu>
> ---
> 
> Notes:
>     This is my first patch on this mailing list. Please let me know if I missed
>     something.
> 
>  fs/ubifs/gc.c | 4 ----
>  1 file changed, 4 deletions(-)
> 
> diff --git a/fs/ubifs/gc.c b/fs/ubifs/gc.c
> index 9718da8..821b348 100644
> --- a/fs/ubifs/gc.c
> +++ b/fs/ubifs/gc.c
> @@ -100,10 +100,6 @@ static int switch_gc_head(struct ubifs_info *c)
>  	if (err)
>  		return err;
>  
> -	err = ubifs_wbuf_sync_nolock(wbuf);
> -	if (err)
> -		return err;
> -
>  	err = ubifs_add_bud_to_log(c, GCHD, gc_lnum, 0);
>  	if (err)
>  		return err;

This call was introduced by:
commit cb14a18465686ea6add51b1008865b8174c28bd7
Author: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Date:   Sun May 15 14:51:54 2011 +0300

    UBIFS: synchronize write-buffer before switching to the next bud


Which basically syncs the wbuf before each ubifs_add_bud_to_log().
In switch_gc_head() we synced already before ubifs_leb_unmap().
So either the said commit oversaw that sync call or I miss something.

But AFACT your change is correct. Artem, can you please confirm?
Boris, didn't discuss that redundancy while inspecting UBIFS wrt. MLC
support?

Thanks,
//richard