From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53760) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gN70u-0002QA-Ni for qemu-devel@nongnu.org; Wed, 14 Nov 2018 21:04:13 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gN70r-0005kj-HL for qemu-devel@nongnu.org; Wed, 14 Nov 2018 21:04:12 -0500 From: Eric Blake Date: Wed, 14 Nov 2018 20:03:32 -0600 Message-Id: <20181115020334.1189829-12-eblake@redhat.com> In-Reply-To: <20181115020334.1189829-1-eblake@redhat.com> References: <20181115020334.1189829-1-eblake@redhat.com> Subject: [Qemu-devel] [PATCH v2 11/13] qcow2: Audit for read/write 64-bit cleanness List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: qemu-block@nongnu.org, kwolf@redhat.com, Max Reitz The qcow2 read/write functions do their own fragmentation (because of cluster remapping); while we could advertise s->cluster_size and let the block layer do fragmentation for us, that would NOT solve the issue of the block layer handing us a length less than a cluster but at an offset which overlaps a cluster boundary. Thus, we still have to fragment ourselves, at which point it is easiest to just document that this driver is 64-bit clean. Signed-off-by: Eric Blake --- block/qcow2.c | 1 + 1 file changed, 1 insertion(+) diff --git a/block/qcow2.c b/block/qcow2.c index 0b5ad130060..1dd3491f77f 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -1687,6 +1687,7 @@ static void qcow2_refresh_limits(BlockDriverState *bs, Error **errp) } bs->bl.pwrite_zeroes_alignment = s->cluster_size; bs->bl.pdiscard_alignment = s->cluster_size; + bs->bl.max_transfer = INT64_MAX; } static int qcow2_reopen_prepare(BDRVReopenState *state, -- 2.17.2