Message-ID: <1392921199.29525.0.camel@haakon3.risingtidesystems.com>
Subject: Re: [PATCH v2] target_core_alua: silence GCC warning
From: "Nicholas A. Bellinger" <nab@linux-iscsi.org>
To: Paul Bolle <pebolle@tiscali.nl>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>, linux-scsi@vger.kernel.org,
        target-devel@vger.kernel.org, linux-kernel@vger.kernel.org
Date: Thu, 20 Feb 2014 10:33:19 -0800
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On Thu, 2014-02-20 at 09:07 +0100, Paul Bolle wrote:
> Building target_core_alua.o triggers a GCC warning:
>     drivers/target/target_core_alua.c: In function ‘target_alua_state_check’:
>     drivers/target/target_core_alua.c:773:18: warning: ‘alua_ascq’ may be used uninitialized in this function [-Wmaybe-uninitialized]
>        cmd->scsi_ascq = alua_ascq;
>                       ^
> 
> This is a false positive. A little trial and error shows it is
> apparently caused by core_alua_state_lba_dependent(). It must be hard
> for GCC to track the branches of a switch statement, inside a
> list_for_each_entry loop, inside a while loop.
> 
> But if we add a small (inline) helper function we can reorganize the
> code a bit. That also allows to drop alua_ascq which, obviously, gets
> rid of this warning.
> 
> Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
> ---
> v2: Make core_alua_state_nonoptimized() return void, as Geert
> suggested. 
> 
> Also keep core_alua_state_lba_dependent() inline. Setting that function
> noinline was just a leftover from the trial and error fase, and isn't
> needed to make the warning go away. Ie, I was sloppy in v1!
> 
> Still compile tested only.
> 
>  drivers/target/target_core_alua.c | 95 ++++++++++++++++++---------------------
>  1 file changed, 44 insertions(+), 51 deletions(-)
> 

Applied to target-pending/for-next.

Thanks Paul!

--nab

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