Jens Axboe <[EMAIL PROTECTED]> writes: > On Thu, Apr 26 2007, Eric W. Biederman wrote: > > Yep, if you could just have > PAGE_CACHE_SIZE blocks in the filesystem > easily, the problem would basically be solved for cd and dvd packet > writing.
Ok. I'm not in a position to do this work. But I will keep it in mind and look at it. >> Am I correct in assuming that the problem is primarily about getting >> filesystems (and other upper layers) to submit BIOs that take into >> consideration the larger block size of the underlying device, so >> that read/modify write is not needed in the pktcdvd layer? > > Yes, that is exactly the problem. Once you have that, pktcdvd is pretty > much reduced to setup and init code, the actual data handling can be > done by sr or ide-cd directly. You could merge it into cdrom.c, it would > not be very different from mt-rainier handling (which basically does RMW > in firmware, so it works for any write, but performance is of course > horrible if you don't do it right). Thanks for the clarification. So we do have a clear problem that we do not have generic support for large sector sizes residing in the page cache. There is one place where this is a direct effect fs/block_dev.c We have an indirect affect in the filesystems because there a few bits of generic support missing and there is no linux convention on how to handle this case. I expect if we can enhance fs/block_dev.c to handle this case the other parts will fall out naturally. Eric - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
