From patchwork Mon Nov 4 16:12:04 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pavel Begunkov X-Patchwork-Id: 13861595 Received: from mail-ej1-f53.google.com (mail-ej1-f53.google.com [209.85.218.53]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1C44E1B393D; Mon, 4 Nov 2024 16:12:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.218.53 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730736728; cv=none; b=gWKJ4V3TKf3Ize9eHtgXkDMBI1GuzMNC52Kj3ZvB34/5YC4AoIAKB61+MdVNKTK3zU679TAE7oVGAmikNfoQbH0jUbK1KQCC6yb6z6Q73SkY+S0o1qDtRW9CxOw4+KAAh8/nhGEMpJKvdbrMRqiRpLIDkuXE+Zpi8kvMum0kK94= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730736728; c=relaxed/simple; bh=vPRwe90zHahHOOj0Z2Qh+3WOfaePnL2PTtvbs7zA2M8=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=C+GG7Et7M0/W9BoG5jviDL5Qo0RhWVVZrBUBbVghz8o2CRxlh2J6zFVMFhbYVnhQyi+5lTw4mZW3TvGn034878K3MflM/zQjKTlgG83CjEcgf/VAH0o+xK1K7MvagTzHiLr+GC453ulHWRC0GlatwaY7o8QQTY7w0ZwoJSvoIAA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=bPZV4Fd5; arc=none smtp.client-ip=209.85.218.53 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="bPZV4Fd5" Received: by mail-ej1-f53.google.com with SMTP id a640c23a62f3a-a9eaaab29bcso111887566b.2; Mon, 04 Nov 2024 08:12:05 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1730736724; x=1731341524; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=e/5b8ihx5vuRnwO1en4w28K6JwXaOVMpIi0lr9UaU58=; b=bPZV4Fd5tII7vFXOCW3Y0GsTCeP25GhthmiEn7+b4Pbk2FaATtG0/g+8HBkwGYTxzD bpoWnBHtjomacJojXWRjd23Oh7b5Vftko8xXx3ntXYpIdN8tqx+7VxiUZzY8BpB5tMmm nX0rZpS660GuAPNCKtcWY+xyk62s37LPfmDmXc34kSpL+qIpZ48/F019pYE9YL70HpK2 mIQQzA1W6isuyf+sXBp4OBrqmSB0U2QvWlGXmZZcUTODQP5nd2a7emLaUNclVnndHyPh O2eHhP3Xsd4o9b7PJxKOCVTIBurdUsK0heuh/95BvyHXEPmjWL20j3+3mKncRB/aH8vH fP5w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1730736724; x=1731341524; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=e/5b8ihx5vuRnwO1en4w28K6JwXaOVMpIi0lr9UaU58=; b=qE+kqXqGdCxboP24YMVLw8/NCKnH73j0wEDJXnP9MqbXigz+tKMTvHtQSWOGi+cKko JGpHOlY2g+SoBUQ82pKAL5bO/1QBluoauYa+Dil7dJhf1MBZrdewJCfcs8IHK8lP3hRs KrewP8WXesgn3C023x13IO7Zj9gKFs6/7KfowA+kF9mepq4eqP6UtY8aJTPWyU9UqoDX aVnK0usGs9Bx1uOsQM4dnxbsko+u4IqjRinRxHIoW5R2QOIApNRV0bkciv2h6H1pIgPd aIemy7cZUtbA3mkKAOPuj7uZNL6oHxd0YRjUeye9oqeRb0QyyFClaF+RmF9qtAgeEhOj 2tuA== X-Forwarded-Encrypted: i=1; AJvYcCUAUmxgJQoV7Gqghfrwl8kohqDW7mI5HIvZX5eZ6V9P9n+OtHG0GCp6GWNj6MVsEmbzW/hN3oPYa5PRkw==@vger.kernel.org X-Gm-Message-State: AOJu0YxB3o6zRfGFjH7/wgdQ/djRnpWvxZtpBlp9761pcUZs+Q2fTSiL iY9IrVXHwp1OHC509HRfHwSS3BPaajt6/aIQMisQyWENtz5b3KjSS9NsKw== X-Google-Smtp-Source: AGHT+IFB7u+BFwqO1pg0HGy/EQuPa6tUq16WBgDsMOF3rH+L9Pv6arPDwilF40PC4gAAX+UMLHuYvQ== X-Received: by 2002:a17:907:868a:b0:a99:e745:d47f with SMTP id a640c23a62f3a-a9e508e50a5mr1533875166b.21.1730736723945; Mon, 04 Nov 2024 08:12:03 -0800 (PST) Received: from 127.0.0.1localhost ([163.114.131.193]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-a9e565f75e7sm576594566b.142.2024.11.04.08.12.03 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 04 Nov 2024 08:12:03 -0800 (PST) From: Pavel Begunkov To: io-uring@vger.kernel.org Cc: Jens Axboe , asml.silence@gmail.com, maharmstone@fb.com, linux-btrfs@vger.kernel.org Subject: [PATCH] io_uring/cmd: let cmds to know about dying task Date: Mon, 4 Nov 2024 16:12:04 +0000 Message-ID: <55888b6a644b4fc490849832fd5c5e5bfed523ef.1730687879.git.asml.silence@gmail.com> X-Mailer: git-send-email 2.46.0 Precedence: bulk X-Mailing-List: io-uring@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 When the taks that submitted a request is dying, a task work for that request might get run by a kernel thread or even worse by a half dismantled task. We can't just cancel the task work without running the callback as the cmd might need to do some clean up, so pass a flag instead. If set, it's not safe to access any task resources and the callback is expected to cancel the cmd ASAP. Signed-off-by: Pavel Begunkov Reviewed-by: Jens Axboe --- Made a bit fancier to avoid conflicts. Mark, as before I'd suggest you to take it and send together with the fix. include/linux/io_uring_types.h | 1 + io_uring/uring_cmd.c | 6 +++++- 2 files changed, 6 insertions(+), 1 deletion(-) diff --git a/include/linux/io_uring_types.h b/include/linux/io_uring_types.h index ad5001102c86..bfdf9cbceda9 100644 --- a/include/linux/io_uring_types.h +++ b/include/linux/io_uring_types.h @@ -37,6 +37,7 @@ enum io_uring_cmd_flags { /* set when uring wants to cancel a previously issued command */ IO_URING_F_CANCEL = (1 << 11), IO_URING_F_COMPAT = (1 << 12), + IO_URING_F_TASK_DEAD = (1 << 13), }; struct io_wq_work_node { diff --git a/io_uring/uring_cmd.c b/io_uring/uring_cmd.c index 40b8b777ba12..f0113548ec92 100644 --- a/io_uring/uring_cmd.c +++ b/io_uring/uring_cmd.c @@ -119,9 +119,13 @@ EXPORT_SYMBOL_GPL(io_uring_cmd_mark_cancelable); static void io_uring_cmd_work(struct io_kiocb *req, struct io_tw_state *ts) { struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd); + unsigned int flags = IO_URING_F_COMPLETE_DEFER; + + if (current->flags & (PF_EXITING | PF_KTHREAD)) + flags |= IO_URING_F_TASK_DEAD; /* task_work executor checks the deffered list completion */ - ioucmd->task_work_cb(ioucmd, IO_URING_F_COMPLETE_DEFER); + ioucmd->task_work_cb(ioucmd, flags); } void __io_uring_cmd_do_in_task(struct io_uring_cmd *ioucmd,