From patchwork Fri Sep 22 16:09:41 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ming Lei X-Patchwork-Id: 13395994 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 01D6FCD4840 for ; Fri, 22 Sep 2023 16:11:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232071AbjIVQLw (ORCPT ); Fri, 22 Sep 2023 12:11:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44664 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232053AbjIVQLv (ORCPT ); Fri, 22 Sep 2023 12:11:51 -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 7BF49100 for ; Fri, 22 Sep 2023 09:11:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1695399059; 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=Avj0AGuwg2DKK7Htq/bKALE2ilhZivn9R4Ch5qJ1ATg=; b=I6Oq1a4NenoKFe/JwLbNDcScg17ISpWWZjR2gai8nIF82rKLfEN+f9HXYqde3qEUhwJxnf 7STIQHa3+3FlHDvZZBYPMtdHPUAW1w0Fbjg5TqvzjAZVEYhup5ffqEBDt507iDMekCTyFD 10Hojcqrhs4DY6PTs9LrCFYjiqBltlo= 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-166-6iVV9z6GMkWS3SzzljH6Pg-1; Fri, 22 Sep 2023 12:10:58 -0400 X-MC-Unique: 6iVV9z6GMkWS3SzzljH6Pg-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (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 93571185A790; Fri, 22 Sep 2023 16:10:57 +0000 (UTC) Received: from localhost (unknown [10.72.120.3]) by smtp.corp.redhat.com (Postfix) with ESMTP id BAB8C20268D7; Fri, 22 Sep 2023 16:10:56 +0000 (UTC) From: Ming Lei To: Jens Axboe , io-uring@vger.kernel.org, linux-block@vger.kernel.org Cc: Gabriel Krisman Bertazi , Ming Lei Subject: [PATCH V3 2/2] io_uring: cancelable uring_cmd Date: Sat, 23 Sep 2023 00:09:41 +0800 Message-ID: <20230922160943.2793779-3-ming.lei@redhat.com> In-Reply-To: <20230922160943.2793779-1-ming.lei@redhat.com> References: <20230922160943.2793779-1-ming.lei@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.4 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. Cc: Gabriel Krisman Bertazi Suggested-by: Jens Axboe Signed-off-by: Ming Lei --- include/linux/io_uring.h | 16 +++++++++++ include/linux/io_uring_types.h | 6 +++++ io_uring/io_uring.c | 34 +++++++++++++++++++++++ io_uring/uring_cmd.c | 49 ++++++++++++++++++++++++++++++++++ 4 files changed, 105 insertions(+) diff --git a/include/linux/io_uring.h b/include/linux/io_uring.h index ae08d6f66e62..a0307289bdc7 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 one 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); +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) @@ -125,6 +132,15 @@ 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/io_uring/io_uring.c b/io_uring/io_uring.c index 783ed0fff71b..1e3de74c2ba3 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -3256,6 +3256,39 @@ 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) + __acquires(ctx->uring_lock) +{ + struct hlist_node *tmp; + struct io_kiocb *req; + bool ret = false; + + 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); + + return ret; +} + static __cold bool io_uring_try_cancel_requests(struct io_ring_ctx *ctx, struct task_struct *task, bool cancel_all) @@ -3303,6 +3336,7 @@ 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 52a455b67163..5832a316359c 100644 --- a/io_uring/uring_cmd.c +++ b/io_uring/uring_cmd.c @@ -13,6 +13,53 @@ #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. + */ +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; + + 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); + } + + 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 +103,8 @@ 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);