Re: [PATCH 05/10] block: drop unnecessary blk_get/put_queue() inscsi_cmd_ioctl() and blk_get_tg()

[Tejun Heo]

Hey, Vivek.

On Wed, Oct 19, 2011 at 09:52:54AM -0400, Vivek Goyal wrote:
> What makes sure that caller has the reference to the queue upon entry. If
> that's the case, that's good. Just that I had not figured it out so
> resorted to defensive programming as taking extra reference does not harm.

The fact that @q can be dereferenced on entry at all. :)

Taking extra reference doesn't help anything.  If the caller doesn't
have standing reference, it will just change where oops occurs.  W/o
extra ref, it will crash soon after the last reference is put.  W/
extra ref, it will crash after the extra ref is put.  If the caller
doesn't hold a reference, there's nothing the callee can do to fix
that.

Thanks.

-- 
tejun
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