[Qemu-devel] [PATCH 0/2] block: Fix qemu-img creating overlay when guest running

Fam Zheng posted 2 patches 6 years, 3 months ago
Patches applied successfully (tree, apply log)
git fetch https://github.com/patchew-project/qemu tags/patchew/20171215080446.10671-1-famz@redhat.com
Test checkpatch passed
Test docker passed
Test ppc passed
Test s390x passed
block.c                    | 3 ++-
tests/qemu-iotests/153     | 4 ++++
tests/qemu-iotests/153.out | 3 +++
3 files changed, 9 insertions(+), 1 deletion(-)
[Qemu-devel] [PATCH 0/2] block: Fix qemu-img creating overlay when guest running
Posted by Fam Zheng 6 years, 3 months ago
Shared write lock is not strictly necessary for creating the overlay image, if
all what we want is to probe the size.

Fam Zheng (2):
  block: Open backing image in force share mode for size probe
  iotests: Test creating overlay when guest running

 block.c                    | 3 ++-
 tests/qemu-iotests/153     | 4 ++++
 tests/qemu-iotests/153.out | 3 +++
 3 files changed, 9 insertions(+), 1 deletion(-)

-- 
2.14.3


Re: [Qemu-devel] [PATCH 0/2] block: Fix qemu-img creating overlay when guest running
Posted by Eric Blake 6 years, 3 months ago
On 12/15/2017 02:04 AM, Fam Zheng wrote:
> Shared write lock is not strictly necessary for creating the overlay image, if
> all what we want is to probe the size.

Theoretically, the size could be changing due to a resize operation.
But realistically, even if that happens, we will (hopefully) see either
the old size or the new size atomically (that is, I seriously doubt the
size information is split across multiple sectors of the in-use image to
the point that we could shard the read).

Series:
Reviewed-by: Eric Blake <eblake@redhat.com>

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
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