Re: [Qemu-devel] [PATCH v6 5/6] iotests: Add new test 214 for max compressed cluster offset

[Eric Blake <eblake@redhat.com>]

On 04/26/2018 07:10 AM, Alberto Garcia wrote:
> On Thu 26 Apr 2018 04:51:28 AM CEST, Eric Blake wrote:
>> If you have a capable file system (tmpfs is good, ext4 not so much;
>> run ./check with TEST_DIR pointing to a good location so as not
>> to skip the test), it's actually possible to create a qcow2 file
>> that expands to a sparse 512T image with just over 38M of content.
>> The test is not the world's fastest (qemu crawling through 256M
>> bits of refcount table to find the next cluster to allocate takes
>> several seconds, as does qemu-img check reporting millions of
>> leaked clusters); but it DOES catch the problem that the previous
>> patch just fixed where writing a compressed cluster to a full
>> image ended up overwriting the wrong cluster.
>>
>> Suggested-by: Max Reitz <mreitz@redhat.com>
>> Signed-off-by: Eric Blake <eblake@redhat.com>
> 
> Nice test :-)
> 
> Reviewed-by: Alberto Garcia <berto@igalia.com>

214 is already in the tree in the meantime; this will need a rebase to 
pick the next available test number (220 might be claimed, so 222?)

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org