From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com [67.231.145.42]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F2EFB1386C9 for ; Thu, 31 Oct 2024 16:33:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=67.231.145.42 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730392392; cv=none; b=HPU26TM2cX3yh9iOZUTK0pA1fCv8CBrbECOXYKJVwN2nadI0EdjY7syjmJGeD7EwdY4Hhz1BNJMPy+5df6ZQHwO06y3ZpNOW3jTmvvp8tB9H9wx8tYYsefVeZGvM4cY/QYuAbOMU3N+FI2kROoWHOCzb3RbJraKjKY9pLChvjpM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730392392; c=relaxed/simple; bh=xikFq93FY6IkyG4gy9dDcY6kw+kFCBf3DpB6Nc9EhWc=; h=From:To:CC:Subject:Date:Message-ID:MIME-Version:Content-Type; b=lSMKmYeMvQ6bxj0XdfzjpNdMLHUeabKgq3wEMUPxeEYFOJLsD6NSZhssCj69RSI1mOdgkPX5akBcOhtu/WuTCau5AOweEO9uFSqAtwwcNOtcwYVzwAOBoPevQC/YWxDqXZPO8wkPwRv7r/UKQCjhGQNkjxARJ/E5tnamUZgUrII= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=fb.com; spf=pass smtp.mailfrom=meta.com; dkim=pass (1024-bit key) header.d=fb.com header.i=@fb.com header.b=YmCFQf0f; arc=none smtp.client-ip=67.231.145.42 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=fb.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=meta.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=fb.com header.i=@fb.com header.b="YmCFQf0f" Received: from pps.filterd (m0148461.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 49VDVpaK003194 for ; Thu, 31 Oct 2024 09:33:09 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=cc :content-transfer-encoding:content-type:date:from:message-id :mime-version:subject:to; s=facebook; bh=/u9KkKOhXWizie9P+ax9UK6 debEdPhtL/cUJoUMTd6M=; b=YmCFQf0fBMlUEy0e7nSAYSUvcvTo8VSTBo6qjMQ Bh2kZ+GD7c0EF0yfjJQaVxTb472voCyiFL3O09Es81W+pJpobr02AX6ubbl25D9/ X1srCNFghg/twM1NTrN1OYmFmobn1NTMjGeGAey1DwS9CZRQbF1Si/XxeOw95qWt 1zh0= Received: from mail.thefacebook.com ([163.114.134.16]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 42m6bdu3yb-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Thu, 31 Oct 2024 09:33:08 -0700 (PDT) Received: from twshared15700.17.frc2.facebook.com (2620:10d:c085:108::150d) by mail.thefacebook.com (2620:10d:c08b:78::2ac9) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.2.1544.11; Thu, 31 Oct 2024 16:33:07 +0000 Received: by devbig276.nha1.facebook.com (Postfix, from userid 660015) id 2A4578404305; Thu, 31 Oct 2024 16:33:04 +0000 (GMT) From: Mark Harmstone To: CC: , Pavel Begunkov Subject: [PATCH 1/2] io_uring/cmd: let cmds to know about dying task Date: Thu, 31 Oct 2024 16:32:51 +0000 Message-ID: <20241031163257.3616106-1-maharmstone@fb.com> X-Mailer: git-send-email 2.43.5 Precedence: bulk X-Mailing-List: io-uring@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-FB-Internal: Safe Content-Type: text/plain X-Proofpoint-GUID: YdToMa5FXCiUO123gkbg2Rx8dIEB0b8q X-Proofpoint-ORIG-GUID: YdToMa5FXCiUO123gkbg2Rx8dIEB0b8q X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1051,Hydra:6.0.680,FMLib:17.12.62.30 definitions=2024-10-05_03,2024-10-04_01,2024-09-30_01 From: Pavel Begunkov 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 --- 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_type= s.h index 4b9ba523978d..2ee5dc105b58 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 =3D (1 << 11), IO_URING_F_COMPAT =3D (1 << 12), + IO_URING_F_TASK_DEAD =3D (1 << 13), }; =20 struct io_wq_work_node { diff --git a/io_uring/uring_cmd.c b/io_uring/uring_cmd.c index 39c3c816ec78..78a8ba5d39ae 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 =3D io_kiocb_to_cmd(req, struct io_uring_cm= d); + unsigned int flags =3D IO_URING_F_COMPLETE_DEFER; + + if (req->task !=3D current) + flags |=3D IO_URING_F_TASK_DEAD; =20 /* task_work executor checks the deffered list completion */ - ioucmd->task_work_cb(ioucmd, IO_URING_F_COMPLETE_DEFER); + ioucmd->task_work_cb(ioucmd, flags); } =20 void __io_uring_cmd_do_in_task(struct io_uring_cmd *ioucmd, --=20 2.45.2