From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:55299) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dxHGt-000491-Gb for qemu-devel@nongnu.org; Wed, 27 Sep 2017 14:41:24 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dxHGs-0007GF-Or for qemu-devel@nongnu.org; Wed, 27 Sep 2017 14:41:23 -0400 References: <20170913160333.23622-1-eblake@redhat.com> <20170913160333.23622-13-eblake@redhat.com> From: John Snow Message-ID: <28a79c88-ca25-70c3-9e5b-fc794854fb34@redhat.com> Date: Wed, 27 Sep 2017 14:41:04 -0400 MIME-Version: 1.0 In-Reply-To: <20170913160333.23622-13-eblake@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v4 12/23] block: Convert bdrv_get_block_status_above() to bytes List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Eric Blake , qemu-devel@nongnu.org Cc: kwolf@redhat.com, famz@redhat.com, qemu-block@nongnu.org, Jeff Cody , Max Reitz , Stefan Hajnoczi On 09/13/2017 12:03 PM, Eric Blake wrote: > We are gradually moving away from sector-based interfaces, towards > byte-based. In the common case, allocation is unlikely to ever use > values that are not naturally sector-aligned, but it is possible > that byte-based values will let us be more precise about allocation > at the end of an unaligned file that can do byte-based access. > > Changing the name of the function from bdrv_get_block_status_above() > to bdrv_block_status_above() ensures that the compiler enforces that > all callers are updated. For now, the io.c layer still assert()s > that all callers are sector-aligned, but that can be relaxed when a > later patch implements byte-based block status in the drivers. > > For the most part this patch is just the addition of scaling at the > callers followed by inverse scaling at bdrv_block_status(). But some > code, particularly bdrv_block_status(), gets a lot simpler because > it no longer has to mess with sectors. Likewise, mirror code no > longer computes s->granularity >> BDRV_SECTOR_BITS, and can therefore > drop an assertion (fix a neighboring assertion to use is_power_of_2 > while there). > Huh, I suppose so, yeah. Do you have a test that covers what happens in this newly available use case? > For ease of review, bdrv_get_block_status() was tackled separately. > > Signed-off-by: Eric Blake > Looks mechanically correct, anyway. Reviewed-by: John Snow