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Date: Sat, 24 Dec 2016 10:49:05 +0100
From: Christoph Hellwig <hch@lst.de>
To: Jens Axboe <axboe@fb.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
        Christoph Hellwig <hch@lst.de>, Chris Leech <cleech@redhat.com>,
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        "Michael S. Tsirkin" <mst@redhat.com>
Subject: Re: [4.10, panic, regression] iscsi: null pointer deref at
        iscsi_tcp_segment_done+0x20d/0x2e0
Message-ID: <20161224094905.GA16518@lst.de>
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On Fri, Dec 23, 2016 at 07:45:45PM -0700, Jens Axboe wrote:
> It's not that it's technically hard to fix up, it's more that it's a
> pain in the ass to have to do it. For instance, for blk_execute_rq(), we
> either should enforce that the caller allocates it dynamically and then
> free it, or we need nasty hack where the caller needs to know he has to
> free it. Pretty obvious what I would prefer there.
> 
> And yes, there would be a good chunk of other places where this would
> nede to be fixed up...

My planned rework for the BLOCK_PC code (split all fields for them out
of struct request and move them into a separate, driver-allocate structure)
would fix this up as a side-effect.  I really wanted to get it into 4.10,
but I didn't manage to fix it up.  I'll try to get it into 4.11 early.