From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Subject: Re: [PATCH 1/2] tcm_vhost: Wait for pending requests in vhost_scsi_flush() Date: Mon, 11 Mar 2013 12:36:37 +0100 Message-ID: <513DC1C5.4070106@redhat.com> References: <1362978579-13322-1-git-send-email-asias@redhat.com> <1362978579-13322-2-git-send-email-asias@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1362978579-13322-2-git-send-email-asias@redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org To: Asias He Cc: kvm@vger.kernel.org, "Michael S. Tsirkin" , virtualization@lists.linux-foundation.org, target-devel@vger.kernel.org, Stefan Hajnoczi List-Id: virtualization@lists.linuxfoundation.org Il 11/03/2013 06:09, Asias He ha scritto: > This patch makes vhost_scsi_flush() wait for all the pending requests > issued before the flush operation to be finished. There is no protection against issuing concurrent flush operations. If we later would like to make the flush a ioctl (for example for migration purposes), it would be confusing, and I'm not sure how you could extend the during_flush machinery. What about making vhost_scsi_flush() wait for all pending requests, including those issues during the flush operation? Then you can easily support concurrent flushes; just add a waitqueue and wake_up_all at the end of the flush operation. BTW, adding such a ioctl as part of this patch would probably be a good thing to do anyway. Paolo