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From: David Howells <dhowells@redhat.com>
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To: Eric Biggers <ebiggers3@gmail.com>
Cc: dhowells@redhat.com, Alexander Viro <viro@zeniv.linux.org.uk>,
        linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
        Eric Biggers <ebiggers@google.com>
Subject: Re: [PATCH 03/18] fs_context: fix detecting full log buffer
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Date: Mon, 09 Jul 2018 10:32:54 +0100
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Eric Biggers <ebiggers3@gmail.com> wrote:

> When 'head' and 'tail' wrap around, 'log->head - log->tail' will be
> something like '4 - 252 = -248', and comparing that directly to the
> array size is wrong.  Fix by casting to 'u8'.

I think a better fix is to use CIRC_CNT() or CIRC_SPACE().

David