Re: [PATCH 12/13] xfs: make the calculation generic in xfs_sb_validate_fsb_count()

[Pankaj Raghav (Samsung)]

On Mon, Feb 26, 2024 at 01:21:56PM +0000, Matthew Wilcox wrote:
> On Mon, Feb 26, 2024 at 10:49:35AM +0100, Pankaj Raghav (Samsung) wrote:
> > +	if (check_mul_overflow(nblocks, (1 << sbp->sb_blocklog), &bytes))
> 
> Why would you not use check_shl_overflow()?

This looks better than check_mul_overflow. I will use this in the next
version.
> 
> > +		return -EFBIG;
> > +
> > +	mapping_count = bytes >> PAGE_SHIFT;
> >  	/* Limited by ULONG_MAX of page cache index */
> > -	if (nblocks >> (PAGE_SHIFT - sbp->sb_blocklog) > ULONG_MAX)
> > +	if (mapping_count > ULONG_MAX)
> >  		return -EFBIG;
> >  	return 0;
> >  }
> > -- 
> > 2.43.0
> >