From 8e3bd35bdb0e26d59e700b35cef3d80823bed66e Mon Sep 17 00:00:00 2001 From: Jeffrey Cody Date: Wed, 21 Mar 2012 21:55:03 +0100 Subject: [PATCH 36/55] block: check bdrv_in_use() before blockdev operations RH-Author: Jeffrey Cody Message-id: Patchwork-id: 38886 O-Subject: [RHEL6.3 qemu-kvm PATCH v8 36/54] block: check bdrv_in_use() before blockdev operations Bugzilla: 582475 RH-Acked-by: Paolo Bonzini RH-Acked-by: Marcelo Tosatti RH-Acked-by: Kevin Wolf From: Stefan Hajnoczi Long-running block operations like block migration and image streaming must have continual access to their block device. It is not safe to perform operations like hotplug, eject, change, resize, commit, or external snapshot while a long-running operation is in progress. This patch adds the missing bdrv_in_use() checks so that block migration and image streaming never have the rug pulled out from underneath them. Signed-off-by: Stefan Hajnoczi Signed-off-by: Kevin Wolf (cherry picked from commit 2d3735d3bf61d5c8e154a197a11535cc65044334) Signed-off-by: Stefan Hajnoczi Signed-off-by: Anthony Liguori Signed-off-by: Jeff Cody --- block.c | 4 ++++ blockdev.c | 17 ++++++++++++++++- 2 files changed, 20 insertions(+), 1 deletions(-) Signed-off-by: Michal Novotny --- block.c | 4 ++++ blockdev.c | 17 ++++++++++++++++- 2 files changed, 20 insertions(+), 1 deletions(-) diff --git a/block.c b/block.c index eeef65e..b9f5ff1 100644 --- a/block.c +++ b/block.c @@ -1033,6 +1033,10 @@ int bdrv_commit(BlockDriverState *bs) return -EACCES; } + if (bdrv_in_use(bs) || bdrv_in_use(bs->backing_hd)) { + return -EBUSY; + } + backing_drv = bs->backing_hd->drv; ro = bs->backing_hd->read_only; strncpy(filename, bs->backing_hd->filename, sizeof(filename)); diff --git a/blockdev.c b/blockdev.c index 1882a71..cdd3ea3 100644 --- a/blockdev.c +++ b/blockdev.c @@ -615,10 +615,16 @@ void do_commit(Monitor *mon, const QDict *qdict) all_devices = !strcmp(device, "all"); QTAILQ_FOREACH(dinfo, &drives, next) { + int ret; + if (!all_devices) if (strcmp(bdrv_get_device_name(dinfo->bdrv), device)) continue; - bdrv_commit(dinfo->bdrv); + ret = bdrv_commit(dinfo->bdrv); + if (ret == -EBUSY) { + qerror_report(QERR_DEVICE_IN_USE, device); + return; + } } } @@ -646,6 +652,11 @@ int do_snapshot_blkdev(Monitor *mon, const QDict *qdict, QObject **ret_data) ret = -1; goto out; } + if (bdrv_in_use(bs)) { + qerror_report(QERR_DEVICE_IN_USE, device); + ret = -1; + goto out; + } pstrcpy(old_filename, sizeof(old_filename), bs->filename); @@ -836,6 +847,10 @@ exit: static int eject_device(Monitor *mon, BlockDriverState *bs, int force) { + if (bdrv_in_use(bs)) { + qerror_report(QERR_DEVICE_IN_USE, bdrv_get_device_name(bs)); + return -1; + } if (!bdrv_dev_has_removable_media(bs)) { qerror_report(QERR_DEVICE_NOT_REMOVABLE, bdrv_get_device_name(bs)); return -1; -- 1.7.7.6