Re: [PATCH] ext4: fix clang build regression

From: Theodore Ts'o
Date: Mon Aug 14 2017 - 08:29:54 EST


On Sat, Aug 12, 2017 at 02:09:29PM +0530, Chandan Rajendra wrote:
> On Monday, August 7, 2017 4:26:51 PM IST Arnd Bergmann wrote:
> > As Stefan pointed out, I misremembered what clang can do specifically,
> > and it turns out that the variable-length array at the end of the
> > structure did not work (a flexible array would have worked here
> > but not solved the problem):
> >
> > fs/ext4/mballoc.c:2303:17: error: fields must have a constant size:
> > 'variable length array in structure' extension will never be supported
> > ext4_grpblk_t counters[blocksize_bits + 2];
> >
> > This reverts part of my previous patch, using a fixed-size array
> > again, but keeping the check for the array overflow.
> >
> > Fixes: 2df2c3402fc8 ("ext4: fix warning about stack corruption")
> > Reported-by: Stefan Agner <stefan@xxxxxxxx>
> > Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
>
> I executed xfstests on a ppc64 machine with both 4k and 64k block size
> combination.
>
> Tested-by: Chandan Rajendra <chandan@xxxxxxxxxxxxxxxxxx>

Thanks, applied.

- Ted