Am 22.06.2016 um 14:27 hat Pavel Butsykin geschrieben: > On 13.06.2016 23:14, Eric Blake wrote: > >On 05/31/2016 03:15 AM, Denis V. Lunev wrote: > >>From: Pavel Butsykin <pbutsy...@virtuozzo.com> > >> > >>Added implementation of the qcow2_co_write_compressed function that > >>will allow us to safely use compressed writes for the qcow2 from running > >>VMs. > >> > >>Signed-off-by: Pavel Butsykin <pbutsy...@virtuozzo.com> > >>Signed-off-by: Denis V. Lunev <d...@openvz.org> > >>CC: Jeff Cody <jc...@redhat.com> > >>CC: Markus Armbruster <arm...@redhat.com> > >>CC: Eric Blake <ebl...@redhat.com> > >>CC: John Snow <js...@redhat.com> > >>CC: Stefan Hajnoczi <stefa...@redhat.com> > >>CC: Kevin Wolf <kw...@redhat.com> > >>--- > >> block/qcow2.c | 89 > >> ++++++++++++++++++++++++++++++++++------------------------- > >> 1 file changed, 52 insertions(+), 37 deletions(-) > >> > >>diff --git a/block/qcow2.c b/block/qcow2.c > >>index c9306a7..38caa66 100644 > >>--- a/block/qcow2.c > >>+++ b/block/qcow2.c > >>@@ -2535,13 +2535,16 @@ static int qcow2_truncate(BlockDriverState *bs, > >>int64_t offset) > >> > >> /* XXX: put compressed sectors first, then all the cluster aligned > >> tables to avoid losing bytes in alignment */ > >>-static int qcow2_write_compressed(BlockDriverState *bs, int64_t sector_num, > >>- const uint8_t *buf, int nb_sectors) > >>+static coroutine_fn int > >>+qcow2_co_write_compressed(BlockDriverState *bs, int64_t sector_num, > >>+ int nb_sectors, QEMUIOVector *qiov) > > > >Is it worth converting to a byte-based qcow2_co_pwrite_compressed() > >while at it? > > Yes, I'll do it for the next version.
I think it makes sense to do this in two steps. That is, one patch for making the function vectored and a second one for making it byte-based. Of course, you can take bytes as a unit even in the first patch, but then just convert it to sector numbers immediately, so that the actual conversion comes separately. Kevin
