On Thu, Jan 10 2008, Jens Axboe wrote: > On Wed, Jan 09 2008, Alasdair G Kergon wrote: > > Here's the latest version of dm-loop, for comparison. > > > > To try it out, > > ln -s dmsetup dmlosetup > > and supply similar basic parameters to losetup. > > (using dmsetup version 1.02.11 or higher) > > Why oh why does dm always insist to reinvent everything? That's bad > enough in itself, but on top of that most of the extra stuff ends up > being essentially unmaintained. > > If we instead improve loop, everyone wins. > > Sorry to sound a bit harsh, but sometimes it doesn't hurt to think a bit > outside your own sandbox.
So I looked at the code - it seems you build a full extent of the blocks in the file, filling holes as you go along. I initally did that as well, but that is to slow to be usable in real life. You also don't support sparse files, falling back to normal fs read/write paths. Supporting sparse files properly is a must, people generally don't want to prealloc a huge disk backing. -- Jens Axboe - To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
