From 2374626a73d2521ef2ba7930fff61635c456e54b Mon Sep 17 00:00:00 2001 Message-Id: <2374626a73d2521ef2ba7930fff61635c456e54b.1376317668.git.minovotn@redhat.com> In-Reply-To: <5877c7fdc54ad8b9608982a08ce5015eb646708a.1376317668.git.minovotn@redhat.com> References: <5877c7fdc54ad8b9608982a08ce5015eb646708a.1376317668.git.minovotn@redhat.com> From: Stefan Hajnoczi Date: Fri, 9 Aug 2013 12:44:00 +0200 Subject: [PATCH 3/4] blockdev: reset werror/rerror on drive_del RH-Author: Stefan Hajnoczi Message-id: <1376052240-2616-1-git-send-email-stefanha@redhat.com> Patchwork-id: 53133 O-Subject: [PATCH RHEL6.5 qemu-kvm] blockdev: reset werror/rerror on drive_del Bugzilla: 970159 RH-Acked-by: Paolo Bonzini RH-Acked-by: Laszlo Ersek RH-Acked-by: Markus Armbruster BZ: 970159 Brew: https://brewweb.devel.redhat.com/taskinfo?taskID=6150182 Upstream-status: 293c51a6ee369228633a8428ab689f14c045ff98 Paolo Bonzini suggested the following test case: 1. Launch a guest and wait at the GRUB boot menu: qemu-system-x86_64 -enable-kvm -m 1024 \ -drive if=none,cache=none,file=test.img,id=foo,werror=stop,rerror=stop -device virtio-blk-pci,drive=foo,id=virtio0,addr=4 2. Hot unplug the device: (qemu) drive_del foo 3. Select the first boot menu entry Without this patch the guest pauses due to ENOMEDIUM. The guest is stuck in a continuous pause loop since the I/O request is retried and fails immediately again when the guest is resumed. With this patch the error is reported to the guest. Note that this scenario actually happens sometimes during libvirt disk hot unplug, where device_del is followed by drive_del. I/O may still be submitted to the drive after drive_del if the guest does not process the PCI hot unplug notification. Reported-by: Dafna Ron Signed-off-by: Stefan Hajnoczi Reviewed-by: Kevin Wolf (cherry picked from commit 293c51a6ee369228633a8428ab689f14c045ff98) Signed-off-by: Stefan Hajnoczi Conflicts: blockdev.c Upstream commit 92aa5c6d77ac29574c1717bcf57827fa1e586f31 ("iostatus: move BlockdevOnError declaration to QAPI") moved the block error constants to QAPI and changed their names. We need to use the old names in RHEL. hmp-commands.hx In RHEL we still use qemu-monitor.hx instead of hmp-commands.hx. --- blockdev.c | 3 +++ qemu-monitor.hx | 4 ++++ 2 files changed, 7 insertions(+) Signed-off-by: Michal Novotny --- blockdev.c | 3 +++ qemu-monitor.hx | 4 ++++ 2 files changed, 7 insertions(+) diff --git a/blockdev.c b/blockdev.c index 1c8d48c..48e16d9 100644 --- a/blockdev.c +++ b/blockdev.c @@ -1317,6 +1317,9 @@ int do_drive_del(Monitor *mon, const QDict *qdict, QObject **ret_data) */ if (bdrv_get_attached_dev(bs)) { bdrv_make_anon(bs); + + /* Further I/O must not pause the guest */ + bdrv_set_on_error(bs, BLOCK_ERR_REPORT, BLOCK_ERR_REPORT); } else { drive_uninit(drive_get_by_blockdev(bs)); } diff --git a/qemu-monitor.hx b/qemu-monitor.hx index 8e974b1..a47766d 100644 --- a/qemu-monitor.hx +++ b/qemu-monitor.hx @@ -177,6 +177,8 @@ Remove host block device. The result is that guest generated IO is no longer submitted against the host device underlying the disk. Once a drive has been deleted, the QEMU Block layer returns -EIO which results in IO errors in the guest for applications that are reading/writing to the device. +These errors are always reported to the guest, regardless of the drive's error +actions (drive options rerror, werror). ETEXI SQMP __com.redhat_drive_del @@ -187,6 +189,8 @@ Remove host block device. The result is that guest generated IO is no longer submitted against the host device underlying the disk. Once a drive has been deleted, the QEMU Block layer returns -EIO which results in IO errors in the guest for applications that are reading/writing to the device. +These errors are always reported to the guest, regardless of the drive's error +actions (drive options rerror, werror). Arguments: -- 1.7.11.7