Re: [Qemu-devel] [PATCH v4 15/23] qemu-img: Add find_nonzero()

[John Snow]

On 09/13/2017 12:03 PM, Eric Blake wrote:
> During 'qemu-img compare', when we are checking that an allocated
> portion of one file is all zeros, we don't need to waste time
> computing how many additional sectors after the first non-zero
> byte are also non-zero.  Create a new helper find_nonzero() to do
> the check for a first non-zero sector, and rebase
> check_empty_sectors() to use it.
> 
> The new interface intentionally uses bytes in its interface, even
> though it still crawls the buffer a sector at a time; it is robust
> to a partial sector at the end of the buffer.
> 
> Signed-off-by: Eric Blake <address@hidden>

Reviewed-by: John Snow <address@hidden>