From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 4C25D253F30 for ; Mon, 7 Apr 2025 13:15:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744031758; cv=none; b=d6vE+ULgsGrqEFD4UjGWcJMPqhcyCO7LuUUFHE4ibC528gEF66AWOSgKpSPunDCcPwM+M0kkHtCY6C+PgdPnvKKXQpJIq7yz51FEBU4tuoABzCk2phRkmig2J2en1p2CpdAQBvHH2MmGtWWGI6PQwgxlTjuIQDje6z4uOMlCZzU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744031758; c=relaxed/simple; bh=Ieluj13KN9IX3gvgona5k3jidMCRjIdN3NIF6dFAaX4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=u+a2mgRa0jarkWGvb7AZd7o616qLZlsSnILtxLrK5odEnFxTAnoIfns+O4RYxjl/IAJVadts4w+SFSjvmcergbj/0l7X2g5bohCkgFQ0ObmAnlnLA4PzZ7R8TmX+iwk5vtY3sotlteQaeY/g9gG+9oXlBqY/Q8PKcX+4tENUjxE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=GrL+JPFb; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="GrL+JPFb" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1744031756; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=mef04b3Clp5tca7zXspfwwlUO3Z3Fq+fgjt6B0Y/HgU=; b=GrL+JPFbZnbxo8YLZvfSAY4yee44e/MQCoLFS7mVoMFjgeSrEarw40uwHenod2ireL9f04 4szQc4GBDFmsd6cmQH2Tio5gbfznQJP9T2EgiWT0JBUXZJxyphxvs/FQ56Na/fYkPUKAbQ 5tU41Qh7Ha3fKqIUykDrS8xWV3NK3Yk= Received: from mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-561-pJAIRYJkNJqF1ZkPGTJ8EA-1; Mon, 07 Apr 2025 09:15:50 -0400 X-MC-Unique: pJAIRYJkNJqF1ZkPGTJ8EA-1 X-Mimecast-MFC-AGG-ID: pJAIRYJkNJqF1ZkPGTJ8EA_1744031749 Received: from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.12]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 13446180AF59; Mon, 7 Apr 2025 13:15:49 +0000 (UTC) Received: from localhost (unknown [10.72.120.16]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id EEF7419541A6; Mon, 7 Apr 2025 13:15:47 +0000 (UTC) From: Ming Lei To: Jens Axboe , linux-block@vger.kernel.org Cc: Caleb Sander Mateos , Uday Shankar , Ming Lei , Keith Busch Subject: [PATCH 01/13] ublk: delay aborting zc request until io_uring returns the buffer Date: Mon, 7 Apr 2025 21:15:12 +0800 Message-ID: <20250407131526.1927073-2-ming.lei@redhat.com> In-Reply-To: <20250407131526.1927073-1-ming.lei@redhat.com> References: <20250407131526.1927073-1-ming.lei@redhat.com> Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 When one request buffer is leased to io_uring via io_buffer_register_bvec(), io_uring guarantees that the buffer will be returned. However ublk aborts request in case that io_uring context is exiting, then ublk_io_release() may observe freed request, and kernel panic is triggered. Fix the issue by delaying to abort zc request until io_uring returns the buffer back. Cc: Keith Busch Fixes: 1f6540e2aabb ("ublk: zc register/unregister bvec") Signed-off-by: Ming Lei --- drivers/block/ublk_drv.c | 31 ++++++++++++++++++++++++++++--- 1 file changed, 28 insertions(+), 3 deletions(-) diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c index 2fd05c1bd30b..76caec28e5ac 100644 --- a/drivers/block/ublk_drv.c +++ b/drivers/block/ublk_drv.c @@ -140,6 +140,17 @@ struct ublk_uring_cmd_pdu { */ #define UBLK_IO_FLAG_NEED_GET_DATA 0x08 + +/* + * Set when this request buffer is leased to ublk server, and cleared when + * the buffer is returned back. + * + * If this flag is set, this request can't be aborted until buffer is + * returned back from io_uring since io_uring is guaranteed to release the + * buffer. + */ +#define UBLK_IO_FLAG_BUF_LEASED 0x10 + /* atomic RW with ubq->cancel_lock */ #define UBLK_IO_FLAG_CANCELED 0x80000000 @@ -1550,7 +1561,8 @@ static void ublk_abort_queue(struct ublk_device *ub, struct ublk_queue *ubq) rq = blk_mq_tag_to_rq(ub->tag_set.tags[ubq->q_id], i); if (rq && blk_mq_request_started(rq)) { io->flags |= UBLK_IO_FLAG_ABORTED; - __ublk_fail_req(ubq, io, rq); + if (!(io->flags & UBLK_IO_FLAG_BUF_LEASED)) + __ublk_fail_req(ubq, io, rq); } } } @@ -1874,8 +1886,18 @@ static void ublk_io_release(void *priv) { struct request *rq = priv; struct ublk_queue *ubq = rq->mq_hctx->driver_data; + struct ublk_io *io = &ubq->ios[rq->tag]; - ublk_put_req_ref(ubq, rq); + io->flags &= ~UBLK_IO_FLAG_BUF_LEASED; + /* + * request has been aborted, and the queue context is exiting, + * and ublk server can't be relied for completing this IO cmd, + * so force to complete it + */ + if (unlikely(io->flags & UBLK_IO_FLAG_ABORTED)) + __ublk_complete_rq(rq); + else + ublk_put_req_ref(ubq, rq); } static int ublk_register_io_buf(struct io_uring_cmd *cmd, @@ -1958,7 +1980,10 @@ static int __ublk_ch_uring_cmd(struct io_uring_cmd *cmd, ret = -EINVAL; switch (_IOC_NR(cmd_op)) { case UBLK_IO_REGISTER_IO_BUF: - return ublk_register_io_buf(cmd, ubq, tag, ub_cmd->addr, issue_flags); + ret = ublk_register_io_buf(cmd, ubq, tag, ub_cmd->addr, issue_flags); + if (!ret) + io->flags |= UBLK_IO_FLAG_BUF_LEASED; + return ret; case UBLK_IO_UNREGISTER_IO_BUF: return ublk_unregister_io_buf(cmd, ub_cmd->addr, issue_flags); case UBLK_IO_FETCH_REQ: -- 2.47.0