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From: Jens Axboe <axboe@kernel.dk>
To: Jann Horn <jannh@google.com>, Pavel Begunkov <asml.silence@gmail.com>
Cc: io-uring@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] io_uring/rsrc: Simplify buffer cloning by locking both rings
Date: Wed, 15 Jan 2025 13:31:11 -0700	[thread overview]
Message-ID: <a652b0a2-4ff6-487e-bc0e-2e3840a2abea@kernel.dk> (raw)
In-Reply-To: <20250115-uring-clone-refactor-v2-1-7289ba50776d@google.com>

On 1/15/25 1:26 PM, Jann Horn wrote:
> The locking in the buffer cloning code is somewhat complex because it goes
> back and forth between locking the source ring and the destination ring.
> 
> Make it easier to reason about by locking both rings at the same time.
> To avoid ABBA deadlocks, lock the rings in ascending kernel address order,
> just like in lock_two_nondirectories().

I'm going to let this one sit for review for a day or two, and since it
depends changes slated for 6.13, I'll queue it up in a post-merge branch
for 6.14 if all goes well.

Thanks!

-- 
Jens Axboe


  reply	other threads:[~2025-01-15 20:31 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-01-15 20:26 [PATCH v2] io_uring/rsrc: Simplify buffer cloning by locking both rings Jann Horn
2025-01-15 20:31 ` Jens Axboe [this message]
2025-01-16 14:13 ` Jens Axboe

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