From patchwork Fri Sep 22 14:28:16 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ming Lei X-Patchwork-Id: 13395863 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 57D85E6FE3C for ; Fri, 22 Sep 2023 14:29:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229923AbjIVO3U (ORCPT ); Fri, 22 Sep 2023 10:29:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34682 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230132AbjIVO3R (ORCPT ); Fri, 22 Sep 2023 10:29:17 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3DB10100 for ; Fri, 22 Sep 2023 07:28:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1695392907; 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; bh=IzjFuc+Ps+XMfA++aToWsKP6POSQuCfjxQ0wjUUzyYM=; b=R7QQxOlyuZ+zr0X7RuycaO0vxZ8YxzZqM9fy5Zvvw3avttQ/vKRFkv/d+Htu4d/3tpG5+P X4NjaSv0mOq+3uVFQXC4y6wcvkQuMcM4sPLPkvjMavtCyso/SxlykA6er9yShlE72YSDfj mMXZJDJ8hHrfA32K5n1mneMFwqdfmCw= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-604-SYeH_5UKORec_SZd2zyi2g-1; Fri, 22 Sep 2023 10:28:24 -0400 X-MC-Unique: SYeH_5UKORec_SZd2zyi2g-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.rdu2.redhat.com [10.11.54.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id D89D68039C1; Fri, 22 Sep 2023 14:28:23 +0000 (UTC) Received: from localhost (unknown [10.72.120.3]) by smtp.corp.redhat.com (Postfix) with ESMTP id 0AB9240C2064; Fri, 22 Sep 2023 14:28:22 +0000 (UTC) From: Ming Lei To: Jens Axboe , io-uring@vger.kernel.org, linux-block@vger.kernel.org Cc: Ming Lei , Gabriel Krisman Bertazi Subject: [PATCH V2] io_uring: cancelable uring_cmd Date: Fri, 22 Sep 2023 22:28:16 +0800 Message-ID: <20230922142816.2784777-1-ming.lei@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.1 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org uring_cmd may never complete, such as ublk, in which uring cmd isn't completed until one new block request is coming from ublk block device. Add cancelable uring_cmd to provide mechanism to driver for cancelling pending commands in its own way. Add API of io_uring_cmd_mark_cancelable() for driver to mark one command as cancelable, then io_uring will cancel this command in io_uring_cancel_generic(). ->uring_cmd() callback is reused for canceling command in driver's way, then driver gets notified with the cancelling from io_uring. Add API of io_uring_cmd_get_task() to help driver cancel handler deal with the canceling. Cc: Gabriel Krisman Bertazi Suggested-by: Jens Axboe Signed-off-by: Ming Lei --- ublk patches: https://github.com/ming1/linux/commits/uring_exit_and_ublk V2: - use ->uring_cmd() with IO_URING_F_CANCEL for canceling command include/linux/io_uring.h | 15 +++++++++++ include/linux/io_uring_types.h | 6 +++++ include/uapi/linux/io_uring.h | 7 +++-- io_uring/io_uring.c | 35 +++++++++++++++++++++++++ io_uring/uring_cmd.c | 48 ++++++++++++++++++++++++++++++++++ 5 files changed, 109 insertions(+), 2 deletions(-) diff --git a/include/linux/io_uring.h b/include/linux/io_uring.h index 106cdc55ff3b..205179a1c191 100644 --- a/include/linux/io_uring.h +++ b/include/linux/io_uring.h @@ -20,6 +20,9 @@ enum io_uring_cmd_flags { IO_URING_F_SQE128 = (1 << 8), IO_URING_F_CQE32 = (1 << 9), IO_URING_F_IOPOLL = (1 << 10), + + /* set when uring wants to cancel one issued command */ + IO_URING_F_CANCEL = (1 << 11), }; struct io_uring_cmd { @@ -82,6 +85,9 @@ static inline void io_uring_free(struct task_struct *tsk) __io_uring_free(tsk); } int io_uring_cmd_sock(struct io_uring_cmd *cmd, unsigned int issue_flags); +int io_uring_cmd_mark_cancelable(struct io_uring_cmd *cmd, + unsigned int issue_flags); +struct task_struct *io_uring_cmd_get_task(struct io_uring_cmd *cmd); #else static inline int io_uring_cmd_import_fixed(u64 ubuf, unsigned long len, int rw, struct iov_iter *iter, void *ioucmd) @@ -122,6 +128,15 @@ static inline int io_uring_cmd_sock(struct io_uring_cmd *cmd, { return -EOPNOTSUPP; } +static inline int io_uring_cmd_mark_cancelable(struct io_uring_cmd *cmd, + unsigned int issue_flags) +{ + return -EOPNOTSUPP; +} +static inline struct task_struct *io_uring_cmd_get_task(struct io_uring_cmd *cmd) +{ + return NULL; +} #endif #endif diff --git a/include/linux/io_uring_types.h b/include/linux/io_uring_types.h index 13d19b9be9f4..1571db76bec1 100644 --- a/include/linux/io_uring_types.h +++ b/include/linux/io_uring_types.h @@ -265,6 +265,12 @@ struct io_ring_ctx { */ struct io_wq_work_list iopoll_list; bool poll_multi_queue; + + /* + * Any cancelable uring_cmd is added to this list in + * ->uring_cmd() by io_uring_cmd_insert_cancelable() + */ + struct hlist_head cancelable_uring_cmd; } ____cacheline_aligned_in_smp; struct { diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h index 8e61f8b7c2ce..29a7a7e71f57 100644 --- a/include/uapi/linux/io_uring.h +++ b/include/uapi/linux/io_uring.h @@ -249,10 +249,13 @@ enum io_uring_op { * sqe->uring_cmd_flags * IORING_URING_CMD_FIXED use registered buffer; pass this flag * along with setting sqe->buf_index. + * IORING_URING_CANCELABLE not for userspace * IORING_URING_CMD_POLLED driver use only */ -#define IORING_URING_CMD_FIXED (1U << 0) -#define IORING_URING_CMD_POLLED (1U << 31) +#define IORING_URING_CMD_FIXED (1U << 0) +/* set by driver, and handled by io_uring to cancel this cmd */ +#define IORING_URING_CMD_CANCELABLE (1U << 30) +#define IORING_URING_CMD_POLLED (1U << 31) /* diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index 783ed0fff71b..a3135fd47a4e 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -3256,6 +3256,40 @@ static __cold bool io_uring_try_cancel_iowq(struct io_ring_ctx *ctx) return ret; } +static bool io_uring_try_cancel_uring_cmd(struct io_ring_ctx *ctx, + struct task_struct *task, bool cancel_all) +{ + struct hlist_node *tmp; + struct io_kiocb *req; + bool ret = false; + + mutex_lock(&ctx->uring_lock); + hlist_for_each_entry_safe(req, tmp, &ctx->cancelable_uring_cmd, + hash_node) { + struct io_uring_cmd *cmd = io_kiocb_to_cmd(req, + struct io_uring_cmd); + struct file *file = req->file; + + if (WARN_ON_ONCE(!file->f_op->uring_cmd)) + continue; + + if (!cancel_all && req->task != task) + continue; + + if (cmd->flags & IORING_URING_CMD_CANCELABLE) { + /* ->sqe isn't available if no async data */ + if (!req_has_async_data(req)) + cmd->sqe = NULL; + file->f_op->uring_cmd(cmd, IO_URING_F_CANCEL); + ret = true; + } + } + io_submit_flush_completions(ctx); + mutex_unlock(&ctx->uring_lock); + + return ret; +} + static __cold bool io_uring_try_cancel_requests(struct io_ring_ctx *ctx, struct task_struct *task, bool cancel_all) @@ -3307,6 +3341,7 @@ static __cold bool io_uring_try_cancel_requests(struct io_ring_ctx *ctx, ret |= io_kill_timeouts(ctx, task, cancel_all); if (task) ret |= io_run_task_work() > 0; + ret |= io_uring_try_cancel_uring_cmd(ctx, task, cancel_all); return ret; } diff --git a/io_uring/uring_cmd.c b/io_uring/uring_cmd.c index 537795fddc87..d6b200a0be33 100644 --- a/io_uring/uring_cmd.c +++ b/io_uring/uring_cmd.c @@ -13,6 +13,52 @@ #include "rsrc.h" #include "uring_cmd.h" +static void io_uring_cmd_del_cancelable(struct io_uring_cmd *cmd, + unsigned int issue_flags) +{ + if (cmd->flags & IORING_URING_CMD_CANCELABLE) { + struct io_kiocb *req = cmd_to_io_kiocb(cmd); + struct io_ring_ctx *ctx = req->ctx; + + io_ring_submit_lock(ctx, issue_flags); + cmd->flags &= ~IORING_URING_CMD_CANCELABLE; + hlist_del(&req->hash_node); + io_ring_submit_unlock(ctx, issue_flags); + } +} + +/* + * Mark this command as concelable, then io_uring_try_cancel_uring_cmd() + * will try to cancel this issued command by sending ->uring_cmd() with + * issue_flags of IO_URING_F_CANCEL. + * + * The command is guaranteed to not be done when calling ->uring_cmd() + * with IO_URING_F_CANCEL, but it is driver's responsibility to deal + * with race between io_uring canceling and normal completion. + */ +int io_uring_cmd_mark_cancelable(struct io_uring_cmd *cmd, + unsigned int issue_flags) +{ + struct io_kiocb *req = cmd_to_io_kiocb(cmd); + struct io_ring_ctx *ctx = req->ctx; + + io_ring_submit_lock(ctx, issue_flags); + if (!(cmd->flags & IORING_URING_CMD_CANCELABLE)) { + cmd->flags |= IORING_URING_CMD_CANCELABLE; + hlist_add_head(&req->hash_node, &ctx->cancelable_uring_cmd); + } + io_ring_submit_unlock(ctx, issue_flags); + + return 0; +} +EXPORT_SYMBOL_GPL(io_uring_cmd_mark_cancelable); + +struct task_struct *io_uring_cmd_get_task(struct io_uring_cmd *cmd) +{ + return cmd_to_io_kiocb(cmd)->task; +} +EXPORT_SYMBOL_GPL(io_uring_cmd_get_task); + 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); @@ -56,6 +102,8 @@ void io_uring_cmd_done(struct io_uring_cmd *ioucmd, ssize_t ret, ssize_t res2, { struct io_kiocb *req = cmd_to_io_kiocb(ioucmd); + io_uring_cmd_del_cancelable(ioucmd, issue_flags); + if (ret < 0) req_set_fail(req);