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Date: Thu, 12 Oct 2006 14:08:30 -0700
From: Andrew Morton <akpm@osdl.org>
To: Akinobu Mita <akinobu.mita@gmail.com>
Cc: linux-kernel@vger.kernel.org, ak@suse.de, Don Mullis <dwm@meer.net>,
       Jens Axboe <axboe@suse.de>
Subject: Re: [patch 5/7] fault-injection capability for disk IO
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On Thu, 12 Oct 2006 16:43:10 +0900
Akinobu Mita <akinobu.mita@gmail.com> wrote:

> @@ -3134,6 +3174,9 @@ end_io:
>  		if (unlikely(test_bit(QUEUE_FLAG_DEAD, &q->queue_flags)))
>  			goto end_io;
>  
> +		if (should_fail_request(bio))
> +			goto end_io;
> +

hm, so we simulate IO errors by failing at make_request() time rather than
at end_that_request_last()-time, which is where IO errors would usually be
reported.

If we're testing the filesystem/VFS/etc layers then that's pretty much
equivalent.  But perhaps there's an argument for doing both.

Jens, could you have a think about it please?