Re: RFC: block/loop.c & crypto

From: Albert D. Cahalan (
Date: Sun Jul 22 2001 - 20:47:26 EST

Andrea Arcangeli writes:
> On Sun, Jul 22, 2001 at 08:53:50PM +0200, Herbert Valerio Riedel wrote:

>> security is not the issue; it's more of practical terms... since
>> 512 byte seems to be the closest practical transfer size (there
>> isn't any smaller blocksize supported with linux) it seems natural
>> to use that one....
> to me it sounds more natural to use the 1k blocksize that seems to
> be backwards compatible automatically (without the special case),
> the only disavantage of 1k compared to 512bytes is the decreased
> security, so if the decreased security is not your concern I'd
> suggest to use the 1k fixed granularity for the IV. 1k is also the
> default BLOCK_SIZE I/O granularity used by old linux (which
> incidentally is why it seems backwards compatible automatically).

Being backwards compatible with non-Linus kernels is less important
than choosing a block size that is fit for all block devices.
Disks, partitions, and block-based filesystems are all organized
in power-of-two multiples of 512 bytes.

The smaller size can handle the larger size; the reverse is not true.
We all have to live with the size choice until the end of time.
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This archive was generated by hypermail 2b29 : Mon Jul 23 2001 - 21:00:16 EST