On 2010-08-12, at 14:15, Joel Becker wrote: > On Thu, Aug 12, 2010 at 12:45:41PM -0600, Andreas Dilger wrote: >> On 2010-08-12, at 11:42, Joel Becker wrote: >>>> +int generic_check_addressable(unsigned blocksize_bits, u64 num_blocks) >>>> +{ >>>> + u64 last_fs_block = num_blocks - 1; >>>> + >>>> + BUG_ON(blocksize_bits < 9); >>>> + BUG_ON(blocksize_bits > PAGE_CACHE_SHIFT); >> >> I'd rather not have a BUG_ON() for a "check" function that may be called with on-disk values by some filesystem. Some filesystems (AFAIR) also handle blocksize > PAGE_SIZE internally, so this helper would not be useful for them. > > Filesystems that handle their own page cache certainly wouldn't > be interested in a generic helper anyway. All of our pagecache assumes > blocks between 512<->PAGE_CACHE_SIZE. > If I change the BUG_ON()s to -EINVAL, does that work? Or do you > have some way you'd like to allow non-pagecache filesystems to use this > as well? That's probably fine for now. If anyone complains, we can always change it later, since they can't possibly depend on this function yet... Cheers, Andreas -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html