From patchwork Thu Sep 28 12:43:25 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ming Lei X-Patchwork-Id: 13402932 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 EBDEAE732C7 for ; Thu, 28 Sep 2023 12:44:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231542AbjI1Mod (ORCPT ); Thu, 28 Sep 2023 08:44:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48590 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231752AbjI1Moc (ORCPT ); Thu, 28 Sep 2023 08:44:32 -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 F3E7C19B for ; Thu, 28 Sep 2023 05:43:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1695905028; 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=WE3TDcP6opJb498k7lPese1JZZAczauI69tmvlqkiDc=; b=KseYy4nvctUJMTL/Wdj84qAP8o6p/4/utkACM7HSwLFBcUr5uYsljNlL9Ocg9eN8aetegu eObT8vHSlME+ydAfdqAwqbnsKplBOXlF4vPBaxuq60J0l2dxnBiFF/WaogOj+t/qj3dk2j a4V9m+RMVzue83yhN7N3wN/wVf+Hh98= Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-524-uUK9RlGEMom3Rl2sxK9o6Q-1; Thu, 28 Sep 2023 08:43:43 -0400 X-MC-Unique: uUK9RlGEMom3Rl2sxK9o6Q-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (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 5DE28280BC98; Thu, 28 Sep 2023 12:43:43 +0000 (UTC) Received: from localhost (unknown [10.72.120.2]) by smtp.corp.redhat.com (Postfix) with ESMTP id 769991055466; Thu, 28 Sep 2023 12:43:42 +0000 (UTC) From: Ming Lei To: Jens Axboe , io-uring@vger.kernel.org, linux-block@vger.kernel.org Cc: Gabriel Krisman Bertazi , Anuj Gupta , Ming Lei Subject: [PATCH V5 2/2] io_uring: cancelable uring_cmd Date: Thu, 28 Sep 2023 20:43:25 +0800 Message-ID: <20230928124327.135679-3-ming.lei@redhat.com> In-Reply-To: <20230928124327.135679-1-ming.lei@redhat.com> References: <20230928124327.135679-1-ming.lei@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.3 Precedence: bulk List-ID: X-Mailing-List: io-uring@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. Reviewed-by: Gabriel Krisman Bertazi Suggested-by: Jens Axboe Signed-off-by: Ming Lei --- include/linux/io_uring.h | 15 +++++++++++ include/linux/io_uring_types.h | 6 +++++ io_uring/io_uring.c | 33 ++++++++++++++++++++++++ io_uring/uring_cmd.c | 47 ++++++++++++++++++++++++++++++++++ 4 files changed, 101 insertions(+) diff --git a/include/linux/io_uring.h b/include/linux/io_uring.h index ae08d6f66e62..b4391e0a9bc8 100644 --- a/include/linux/io_uring.h +++ b/include/linux/io_uring.h @@ -20,9 +20,13 @@ 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 a previously issued command */ + IO_URING_F_CANCEL = (1 << 11), }; /* only top 8 bits of sqe->uring_cmd_flags for kernel internal use */ +#define IORING_URING_CMD_CANCELABLE (1U << 30) #define IORING_URING_CMD_POLLED (1U << 31) struct io_uring_cmd { @@ -85,6 +89,9 @@ 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); +void 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) @@ -125,6 +132,14 @@ static inline int io_uring_cmd_sock(struct io_uring_cmd *cmd, { return -EOPNOTSUPP; } +static inline void io_uring_cmd_mark_cancelable(struct io_uring_cmd *cmd, + unsigned int issue_flags) +{ +} +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/io_uring/io_uring.c b/io_uring/io_uring.c index 9aedb7202403..1820d7989a9e 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -350,6 +350,7 @@ static __cold struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p) INIT_WQ_LIST(&ctx->locked_free_list); INIT_DELAYED_WORK(&ctx->fallback_work, io_fallback_req_func); INIT_WQ_LIST(&ctx->submit_state.compl_reqs); + INIT_HLIST_HEAD(&ctx->cancelable_uring_cmd); return ctx; err: kfree(ctx->cancel_table.hbs); @@ -3256,6 +3257,37 @@ 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; + + lockdep_assert_held(&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 (!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); + + return ret; +} + static __cold bool io_uring_try_cancel_requests(struct io_ring_ctx *ctx, struct task_struct *task, bool cancel_all) @@ -3303,6 +3335,7 @@ static __cold bool io_uring_try_cancel_requests(struct io_ring_ctx *ctx, ret |= io_cancel_defer_files(ctx, task, cancel_all); mutex_lock(&ctx->uring_lock); ret |= io_poll_remove_all(ctx, task, cancel_all); + ret |= io_uring_try_cancel_uring_cmd(ctx, task, cancel_all); mutex_unlock(&ctx->uring_lock); ret |= io_kill_timeouts(ctx, task, cancel_all); if (task) diff --git a/io_uring/uring_cmd.c b/io_uring/uring_cmd.c index a0b0ec5473bf..00a5e5621a28 100644 --- a/io_uring/uring_cmd.c +++ b/io_uring/uring_cmd.c @@ -13,6 +13,51 @@ #include "rsrc.h" #include "uring_cmd.h" +static void io_uring_cmd_del_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; + + if (!(cmd->flags & IORING_URING_CMD_CANCELABLE)) + return; + + cmd->flags &= ~IORING_URING_CMD_CANCELABLE; + io_ring_submit_lock(ctx, issue_flags); + 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. + */ +void 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; + + if (!(cmd->flags & IORING_URING_CMD_CANCELABLE)) { + cmd->flags |= IORING_URING_CMD_CANCELABLE; + io_ring_submit_lock(ctx, issue_flags); + hlist_add_head(&req->hash_node, &ctx->cancelable_uring_cmd); + io_ring_submit_unlock(ctx, issue_flags); + } +} +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 +101,8 @@ 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);