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Date: Wed, 06 Nov 2013 13:29:37 +0100
From: Paolo Bonzini <pbonzini@redhat.com>
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Subject: Re: [Qemu-devel] [PATCH 3/3] COW: Skip setting already set bits
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To: Charlie Shepherd <charlie@ctshepherd.com>
Cc: kwolf@redhat.com, stefanha@gmail.com, gabriel@kerneis.info, qemu-devel@nongnu.org

Il 06/11/2013 13:23, Charlie Shepherd ha scritto:
> +        set = cow_find_streak(bitmap, 1, bitnum, sector_bits);
> +        if (set == sector_bits) {
> +            continue;

I think this shouldn't be a continue; these lines should be executed:

        bitnum += sector_bits;
        nb_sectors -= sector_bits;
        offset += BDRV_SECTOR_SIZE;

> +        }
> +        bitnum += set;

Here you're adjusting bitnum but not nb_sectors and sector_bits.

Paolo