Re: [RFC PATCH] kvm tools, qcow: Add support for growing refcount blocks

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Am 12.12.2011 12:15, schrieb Kevin Wolf:
> Am 12.12.2011 11:58, schrieb Pekka Enberg:
>> On Mon, 12 Dec 2011, Kevin Wolf wrote:
>>>> @@ -667,14 +722,11 @@ static struct qcow_refcount_block *qcow_read_refcount_block(struct qcow *q, u64
>>>>
>>>>  	rft_idx = clust_idx >> (header->cluster_bits - QCOW_REFCOUNT_BLOCK_SHIFT);
>>>>  	if (rft_idx >= rft->rf_size)
>>>> -		return NULL;
>>>> +		return (void *)-ENOSPC;
>>>
>>> Is this allowed style in kvm-tool? :-/
>>
>> It needs to use ERR_PTR() and related macros but otherwise I don't see a 
>> big problem with it.
> 
> Can you be sure that it never clashes with a valid allocation when you
> use this in userspace?

Er, not sure what I was thinking, but it's the top 4k of the address
space, which should be kernel memory. So I think you actually can be sure.

Kevin
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html


[Index of Archives]     [KVM ARM]     [KVM ia64]     [KVM ppc]     [Virtualization Tools]     [Spice Development]     [Libvirt]     [Libvirt Users]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite Questions]     [Linux Kernel]     [Linux SCSI]     [XFree86]
  Powered by Linux