Date: Fri, 18 Dec 2015 23:31:03 +0800
From: Minfei Huang <mnfhuang@gmail.com>
To: axboe@kernel.dk
Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
        mhuang@redhat.com
Subject: Re: [PATCH 1/2] bio: Remove the incorrect test for idx in
 __bio_clone_fast
Message-ID: <20151218153103.GB19027@dhcp-129-201.nay.redhat.com>
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On 12/18/15 at 11:02P, Minfei Huang wrote:
> It is more lucky that kernel crash does not happen, since we test the
> bi_pool in function __bio_clone_fast. Now bi_flags is used to flag the
> idx, so it is incorrect to test the bi_pool.
> 
> For now, the bio in function __bio_clone_fast may have its own bvec, if
> the caller is bio_clone_fast.
> 
> Removing the test to fix this issue.
> 
> Signed-off-by: Minfei Huang <mnfhuang@gmail.com>
> ---
>  block/bio.c | 2 --
>  1 file changed, 2 deletions(-)
> 
> diff --git a/block/bio.c b/block/bio.c
> index 4f184d9..70d9814 100644
> --- a/block/bio.c
> +++ b/block/bio.c
> @@ -573,8 +573,6 @@ EXPORT_SYMBOL(bio_phys_segments);
>   */
>  void __bio_clone_fast(struct bio *bio, struct bio *bio_src)
>  {
> -	BUG_ON(bio->bi_pool && BIO_POOL_IDX(bio) != BIO_POOL_NONE);
> -

Sorry to bother you, since I have missed the nr_iovecs in function
bio_clone_fast.

Will update this patch to make test correct, instead of removing it.

Thanks
Minfei
	
>  	/*
>  	 * most users will be overriding ->bi_bdev with a new target,
>  	 * so we don't set nor calculate new physical/hw segment counts here
> -- 
> 2.6.3
> 
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