On Thu, Oct 5, 2017 at 4:06 PM, Al Viro <viro@xxxxxxxxxxxxxxxxxx> wrote: > > Just to make sure we are on the same page: out of kstatfs fields > we have 5 u64 ones (see above; all of them are u64 is struct statfs64 > on all architectures), an opaque 64bit f_fsid and 5 fields that > are long: f_type (magic numbers, all 32bit), f_namelen (max filename > length), f_frsize (0 on most of filesystems, always fits into 32 bits), > f_flags (guaranteed to be 32bit) and f_bsize. Please just use that FITS_IN() kind of macro regardless. If the sizes match, the compiler will optimize the test away. If the sizes don't match, that FITS_IN() will do the right thing. Do *not* manually go and say "these fields are ok, because..". The whole bug was because people were confused about the field widths. Linus