Re: [Qemu-devel] [PATCH v2] qcow2: Assert that refcount block offsets fit in the refcount table

[Kevin Wolf]

Am 14.11.2018 um 15:58 hat Alberto Garcia geschrieben:
> Refcount table entries have a field to store the offset of the
> refcount block. The rest of the bits of the entry are currently
> reserved.
> 
> The offset is always taken from the entry using REFT_OFFSET_MASK to
> ensure that we only use the bits that belong to that field.
> 
> While that mask is used every time we read from the refcount table, it
> is never used when we write to it. Due to the other constraints of the
> qcow2 format QEMU can never produce refcount block offsets that don't
> fit in that field so any such offset when allocating a refcount block
> would indicate a bug in QEMU.
> 
> Signed-off-by: Alberto Garcia <address@hidden>
> Reviewed-by: Eric Blake <address@hidden>

Thanks, applied to the block branch.

Kevin