Re: [PATCH] ocfs2: remove useless code in ocfs2_try_to_merge_extent

[Su Hui]

On 2024/1/17 04:09, Andrew Morton wrote:
> On Fri, 12 Jan 2024 12:26:40 +0800 Su Hui <suhui@xxxxxxxxxxxx> wrote:
>
> > Clang static checker warning: Value stored to 'rec' is never read.
> > Remove this useless code to silent this warning.
> >
> > --- a/fs/ocfs2/alloc.c
> > +++ b/fs/ocfs2/alloc.c
> > @@ -3743,8 +3743,6 @@ static int ocfs2_try_to_merge_extent(handle_t *handle,
> >   			goto out;
> >   		}
> >   
> > -		rec = &el->l_recs[split_index];
> > -
> >   		/*
> >   		 * Note that we don't pass split_rec here on purpose -
> >   		 * we've merged it into the rec already.
> Then:
>
> 		ret = ocfs2_merge_rec_left(path, handle, et, rec,
> 					   dealloc, split_index);
>
> and ocfs2_merge_rec_left() almost immediately dereferences `rec'.
>
> So this looks quite wrong to me.
Oh, really sorry for the noise.
This patch is wrong.

Su Hui