From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53889) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Ur7r2-0001Co-99 for qemu-devel@nongnu.org; Mon, 24 Jun 2013 10:34:56 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Ur7r1-00065h-3l for qemu-devel@nongnu.org; Mon, 24 Jun 2013 10:34:52 -0400 Received: from mx1.redhat.com ([209.132.183.28]:12111) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Ur7r0-00065d-Sz for qemu-devel@nongnu.org; Mon, 24 Jun 2013 10:34:51 -0400 Message-ID: <51C85904.50903@redhat.com> Date: Mon, 24 Jun 2013 16:34:44 +0200 From: Paolo Bonzini MIME-Version: 1.0 References: <1371934712-11714-1-git-send-email-pl@kamp.de> <1371934712-11714-4-git-send-email-pl@kamp.de> In-Reply-To: <1371934712-11714-4-git-send-email-pl@kamp.de> Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 3/8] iscsi: add bdrv_co_write_zeroes List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Lieven Cc: Kevin Wolf , ronniesahlberg@gmail.com, qemu-devel@nongnu.org, Stefan Hajnoczi Il 22/06/2013 22:58, Peter Lieven ha scritto: > write zeroes is emulated by unmap if the > target supports unmapping an unmapped blocks > read as zero. I think you should check BDRV_O_UNMAP in bs->open_flags, and not do this optimization if it is not set. Paolo > Signed-off-by: Peter Lieven > --- > block/iscsi.c | 63 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 63 insertions(+) > > diff --git a/block/iscsi.c b/block/iscsi.c > index 98be71e..683692a 100644 > --- a/block/iscsi.c > +++ b/block/iscsi.c > @@ -906,6 +906,68 @@ static int coroutine_fn iscsi_co_is_allocated(BlockDriverState *bs, > return ret; > } > > +static void > +iscsi_co_write_zeroes_cb(struct iscsi_context *iscsi, int status, > + void *command_data, void *opaque) > +{ > + struct IscsiTask *iTask = opaque; > + struct scsi_task *task = command_data; > + > + iTask->complete = 1; > + iTask->status = 0; > + > + if (status != 0) { > + error_report("iSCSI: Failed to unmap data on iSCSI lun. %s", > + iscsi_get_error(iscsi)); > + iTask->status = 1; > + } > + > + scsi_free_scsi_task(task); > + > + if (iTask->co) { > + qemu_coroutine_enter(iTask->co, NULL); > + } > +} > + > +static int > +coroutine_fn iscsi_co_write_zeroes(BlockDriverState *bs, int64_t sector_num, > + int nb_sectors) > +{ > + IscsiLun *iscsilun = bs->opaque; > + struct IscsiTask iTask; > + struct unmap_list list[1]; > + > + if (!iscsilun->lbprz || !iscsilun->lbpu) { > + /* fall back to writev */ > + return -ENOTSUP; > + } > + > + iTask.iscsilun = iscsilun; > + iTask.status = 0; > + iTask.complete = 0; > + iTask.bs = bs; > + > + list[0].lba = sector_qemu2lun(sector_num, iscsilun); > + list[0].num = nb_sectors * BDRV_SECTOR_SIZE / iscsilun->block_size; > + > + if (iscsi_unmap_task(iscsilun->iscsi, iscsilun->lun, 0, 0, &list[0], 1, > + iscsi_co_write_zeroes_cb, &iTask) == NULL) { > + return -EIO; > + } > + > + while (!iTask.complete) { > + iscsi_set_events(iscsilun); > + iTask.co = qemu_coroutine_self(); > + qemu_coroutine_yield(); > + } > + > + if (iTask.status != 0) { > + return -EIO; > + } > + > + return 0; > +} > + > static int parse_chap(struct iscsi_context *iscsi, const char *target) > { > QemuOptsList *list; > @@ -1417,6 +1479,7 @@ static BlockDriver bdrv_iscsi = { > .bdrv_truncate = iscsi_truncate, > > .bdrv_co_is_allocated = iscsi_co_is_allocated, > + .bdrv_co_write_zeroes = iscsi_co_write_zeroes, > > .bdrv_aio_readv = iscsi_aio_readv, > .bdrv_aio_writev = iscsi_aio_writev, >