From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57059) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Zwumr-0000co-NC for qemu-devel@nongnu.org; Thu, 12 Nov 2015 11:31:50 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Zwumm-0007Ji-0k for qemu-devel@nongnu.org; Thu, 12 Nov 2015 11:31:49 -0500 Received: from mx-v6.kamp.de ([2a02:248:0:51::16]:41271 helo=mx01.kamp.de) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Zwuml-0007Ii-Kf for qemu-devel@nongnu.org; Thu, 12 Nov 2015 11:31:43 -0500 From: Peter Lieven Date: Thu, 12 Nov 2015 17:30:40 +0100 Message-Id: <1447345846-15624-1-git-send-email-pl@kamp.de> Subject: [Qemu-devel] [PATCH V4 0/6] ide: avoid main-loop hang on CDROM/NFS failure List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org, qemu-block@nongnu.org Cc: kwolf@redhat.com, famz@redhat.com, stefanha@gmail.com, jcody@redhat.com, Peter Lieven , jsnow@redhat.com This series aims at avoiding a hanging main-loop if a vserver has a CDROM image mounted from a NFS share and that NFS share goes down. Typical situation is that users mount an CDROM ISO to install something and then forget to eject that CDROM afterwards. As a consequence this mounted CD is able to bring down the whole vserver if the backend NFS share is unreachable. This is bad especially if the CDROM itself is not needed anymore at this point. v3->v4: - Patch 1: remove buf argument for cd_read_sector{_sync} - Patch 1: fix iov_base offset for 2352 sector size - Patch 2: fix indent [Fam] - Patch 3: fix leaking of req->iov.iov_base [Fam] v2->v3: - adressed Stefans comments on Patch 1 - added patches 2,4,5,6 - avoided the term cancel in Patch 3. Added an iovec, added a BH [Stefan] v1->v2: - fix offset for 2352 byte sector size [Kevin] - use a sync request if we continue an elementary transfer. As John pointed out we enter a race condition between next IDE command and async transfer otherwise. This is sill not optimal, but it fixes the NFS down problems for all cases where the NFS server goes down while there is no PIO CD activity. Of course, it could still happen during a PIO transfer, but I expect this to be the unlikelier case. I spent some effort trying to read more sectors at once and avoiding continuation of elementary transfers, but with whatever I came up it was destroying migration between different Qemu versions. I have a quite hackish patch that works and should survive migration, but I am not happy with it. So I would like to start with this version as it is a big improvement already. - Dropped Patch 5 because it is upstream meanwhile. Peter Lieven (6): ide/atapi: make PIO read requests async block: add blk_abort_aio_request ide: add support for IDEBufferedRequest ide: orphan all buffered requests on DMA cancel ide: enable buffered requests for ATAPI devices ide: enable buffered requests for PIO read requests block/block-backend.c | 17 +++---- hw/ide/atapi.c | 103 +++++++++++++++++++++++++++++++++++------ hw/ide/core.c | 51 +++++++++++++++++++- hw/ide/internal.h | 14 ++++++ hw/ide/pci.c | 19 ++++++++ include/sysemu/block-backend.h | 3 ++ 6 files changed, 182 insertions(+), 25 deletions(-) -- 1.9.1