From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-18.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, UNPARSEABLE_RELAY,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D4CDBC2D0E4 for ; Fri, 18 Dec 2020 18:10:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A8DBF23B75 for ; Fri, 18 Dec 2020 18:10:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728103AbgLRSK0 (ORCPT ); Fri, 18 Dec 2020 13:10:26 -0500 Received: from userp2130.oracle.com ([156.151.31.86]:40440 "EHLO userp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727874AbgLRSK0 (ORCPT ); Fri, 18 Dec 2020 13:10:26 -0500 Received: from pps.filterd (userp2130.oracle.com [127.0.0.1]) by userp2130.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 0BII4QDQ147241; Fri, 18 Dec 2020 18:09:42 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : subject : date : message-id : in-reply-to : references; s=corp-2020-01-29; bh=DLQZDpkH3xFrKQYlFQU+7dAhp32Cm9AWcpd9yCW+PuE=; b=ioWQW5KmF6t9vsKsr5nFDP5TrRKoFaBrpSWqt4rskJodQL5xfXbBooTnrm403ihdAAXD YQPxZkARvMOxPcTtCcUKbM+bc2ylHRs2WPPdZKG0hLAyG0dQtTb9QT3cxIjYe5vxBiy2 jetHeIzY0QjkdaNxXUjP6T7lJwDKZvfzvWScW2wWdDJG2CH+JQxmIdGcOv8zQb1sG3U+ vTXz/OIbBrn+BURSE0yF5dwTe/VpyjQsiGkb4cnoQoXV/DfnRwwXhnWlqhX1Fouyog94 RYCdTA2aSKuYtV5Q/SZ1wCdv63svDiLduaR+bINIJKB5nde7hQo5OzRDXxSzaEaRTGzG gg== Received: from aserp3020.oracle.com (aserp3020.oracle.com [141.146.126.70]) by userp2130.oracle.com with ESMTP id 35cn9ruj49-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Fri, 18 Dec 2020 18:09:42 +0000 Received: from pps.filterd (aserp3020.oracle.com [127.0.0.1]) by aserp3020.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 0BII5RGV095909; Fri, 18 Dec 2020 18:07:41 GMT Received: from aserv0122.oracle.com (aserv0122.oracle.com [141.146.126.236]) by aserp3020.oracle.com with ESMTP id 35e6ev0xpq-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 18 Dec 2020 18:07:41 +0000 Received: from abhmp0007.oracle.com (abhmp0007.oracle.com [141.146.116.13]) by aserv0122.oracle.com (8.14.4/8.14.4) with ESMTP id 0BII7fIL015980; Fri, 18 Dec 2020 18:07:41 GMT Received: from ca-ldom147.us.oracle.com (/10.129.68.131) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Fri, 18 Dec 2020 10:07:41 -0800 From: Bijan Mottahedeh To: axboe@kernel.dk, asml.silence@gmail.com, io-uring@vger.kernel.org Subject: [PATCH v3 13/13] io_uring: support buffer registration sharing Date: Fri, 18 Dec 2020 10:07:28 -0800 Message-Id: <1608314848-67329-14-git-send-email-bijan.mottahedeh@oracle.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1608314848-67329-1-git-send-email-bijan.mottahedeh@oracle.com> References: <1608314848-67329-1-git-send-email-bijan.mottahedeh@oracle.com> X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9839 signatures=668683 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 adultscore=0 mlxscore=0 phishscore=0 bulkscore=0 suspectscore=0 malwarescore=0 mlxlogscore=999 spamscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2012180124 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9839 signatures=668683 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 adultscore=0 mlxlogscore=999 impostorscore=0 lowpriorityscore=0 clxscore=1015 spamscore=0 malwarescore=0 priorityscore=1501 phishscore=0 mlxscore=0 bulkscore=0 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2012180124 Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org Implement buffer sharing among multiple rings. A ring shares its (future) buffer registrations at setup time with IORING_SETUP_SHARE_BUF. A ring attaches to another ring's buffer registration at setup time with IORING_SETUP_ATTACH_BUF, after authenticating with the buffer registration owner's fd. Any updates to the owner's buffer registrations become immediately available to the attached rings. Signed-off-by: Bijan Mottahedeh --- fs/io_uring.c | 85 +++++++++++++++++++++++++++++++++++++++++-- include/uapi/linux/io_uring.h | 2 + 2 files changed, 83 insertions(+), 4 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index f5706e1..1341526 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -8411,6 +8411,13 @@ static void io_buffers_map_free(struct io_ring_ctx *ctx) ctx->nr_user_bufs = 0; } +static void io_detach_buf_data(struct io_ring_ctx *ctx) +{ + percpu_ref_put(&ctx->buf_data->refs); + ctx->buf_data = NULL; + ctx->nr_user_bufs = 0; +} + static int io_sqe_buffers_unregister(struct io_ring_ctx *ctx) { struct fixed_rsrc_data *data = ctx->buf_data; @@ -8418,6 +8425,11 @@ static int io_sqe_buffers_unregister(struct io_ring_ctx *ctx) if (!data) return -ENXIO; + if (ctx->flags & IORING_SETUP_ATTACH_BUF) { + io_detach_buf_data(ctx); + return 0; + } + io_rsrc_ref_quiesce(data, ctx); io_buffers_unmap(ctx); io_buffers_map_free(ctx); @@ -8662,9 +8674,13 @@ static struct fixed_rsrc_data *io_buffers_map_alloc(struct io_ring_ctx *ctx, if (!nr_args || nr_args > IORING_MAX_FIXED_BUFS) return ERR_PTR(-EINVAL); - buf_data = alloc_fixed_rsrc_data(ctx); - if (IS_ERR(buf_data)) - return buf_data; + if (ctx->buf_data) { + buf_data = ctx->buf_data; + } else { + buf_data = alloc_fixed_rsrc_data(ctx); + if (IS_ERR(buf_data)) + return buf_data; + } nr_tables = DIV_ROUND_UP(nr_args, IORING_MAX_BUFS_TABLE); buf_data->table = kcalloc(nr_tables, sizeof(*buf_data->table), @@ -8729,9 +8745,17 @@ static int io_sqe_buffers_register(struct io_ring_ctx *ctx, void __user *arg, if (ctx->nr_user_bufs) return -EBUSY; + if (ctx->flags & IORING_SETUP_ATTACH_BUF) { + if (!ctx->buf_data) + return -EFAULT; + ctx->nr_user_bufs = ctx->buf_data->ctx->nr_user_bufs; + return 0; + } + buf_data = io_buffers_map_alloc(ctx, nr_args); if (IS_ERR(buf_data)) return PTR_ERR(buf_data); + ctx->buf_data = buf_data; for (i = 0; i < nr_args; i++, ctx->nr_user_bufs++) { struct fixed_rsrc_table *table; @@ -8759,7 +8783,6 @@ static int io_sqe_buffers_register(struct io_ring_ctx *ctx, void __user *arg, break; } - ctx->buf_data = buf_data; if (ret) { io_sqe_buffers_unregister(ctx); return ret; @@ -9789,6 +9812,55 @@ static int io_uring_get_fd(struct io_ring_ctx *ctx) return ret; } +static int io_attach_buf_data(struct io_ring_ctx *ctx, + struct io_uring_params *p) +{ + struct io_ring_ctx *ctx_attach; + struct fd f; + + f = fdget(p->wq_fd); + if (!f.file) + return -EBADF; + if (f.file->f_op != &io_uring_fops) { + fdput(f); + return -EINVAL; + } + + ctx_attach = f.file->private_data; + if (!ctx_attach->buf_data) { + fdput(f); + return -EINVAL; + } + ctx->buf_data = ctx_attach->buf_data; + + percpu_ref_get(&ctx->buf_data->refs); + fdput(f); + return 0; +} + +static int io_init_buf_data(struct io_ring_ctx *ctx, struct io_uring_params *p) +{ + if ((p->flags & (IORING_SETUP_SHARE_BUF | IORING_SETUP_ATTACH_BUF)) == + (IORING_SETUP_SHARE_BUF | IORING_SETUP_ATTACH_BUF)) + return -EINVAL; + + if (p->flags & IORING_SETUP_SHARE_BUF) { + struct fixed_rsrc_data *buf_data; + + buf_data = alloc_fixed_rsrc_data(ctx); + if (IS_ERR(buf_data)) + return PTR_ERR(buf_data); + + ctx->buf_data = buf_data; + return 0; + } + + if (p->flags & IORING_SETUP_ATTACH_BUF) + return io_attach_buf_data(ctx, p); + + return 0; +} + static int io_uring_create(unsigned entries, struct io_uring_params *p, struct io_uring_params __user *params) { @@ -9903,6 +9975,10 @@ static int io_uring_create(unsigned entries, struct io_uring_params *p, if (ret) goto err; + ret = io_init_buf_data(ctx, p); + if (ret) + goto err; + ret = io_sq_offload_create(ctx, p); if (ret) goto err; @@ -9974,6 +10050,7 @@ static long io_uring_setup(u32 entries, struct io_uring_params __user *params) if (p.flags & ~(IORING_SETUP_IOPOLL | IORING_SETUP_SQPOLL | IORING_SETUP_SQ_AFF | IORING_SETUP_CQSIZE | IORING_SETUP_CLAMP | IORING_SETUP_ATTACH_WQ | + IORING_SETUP_SHARE_BUF | IORING_SETUP_ATTACH_BUF | IORING_SETUP_R_DISABLED)) return -EINVAL; diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h index 0d9ac12..2366126 100644 --- a/include/uapi/linux/io_uring.h +++ b/include/uapi/linux/io_uring.h @@ -98,6 +98,8 @@ enum { #define IORING_SETUP_CLAMP (1U << 4) /* clamp SQ/CQ ring sizes */ #define IORING_SETUP_ATTACH_WQ (1U << 5) /* attach to existing wq */ #define IORING_SETUP_R_DISABLED (1U << 6) /* start with ring disabled */ +#define IORING_SETUP_SHARE_BUF (1U << 7) /* share buffer registration */ +#define IORING_SETUP_ATTACH_BUF (1U << 8) /* attach buffer registration */ enum { IORING_OP_NOP, -- 1.8.3.1