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=-19.0 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 1ED4BC43331 for ; Wed, 6 Jan 2021 20:40:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F1BE423138 for ; Wed, 6 Jan 2021 20:40:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727150AbhAFUkU (ORCPT ); Wed, 6 Jan 2021 15:40:20 -0500 Received: from aserp2130.oracle.com ([141.146.126.79]:55974 "EHLO aserp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727362AbhAFUkT (ORCPT ); Wed, 6 Jan 2021 15:40:19 -0500 Received: from pps.filterd (aserp2130.oracle.com [127.0.0.1]) by aserp2130.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 106KYmnd037719; Wed, 6 Jan 2021 20:39:36 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=YLBOrTQu6qneB3Nq8zUj+3l5Ola5H4hVynLNmuMcXQo=; b=DDKzcF8XA/tlx54cKNXZ9GeLYNzQCpODs1IKeoyIxUTch1PXS43lBcCyYQph+eOCwWUA x6vC4shfGZjLtgOlqLTyZ4a2pQwhFlKJ2+tArz7H7uRYr/OCOG8E83kItmv338sXlh9Y /Hg+99NVk+DyX39dg9albMEAur+N3Lk937nkWkkgXaas8oCzgPjFZXX2fTavA670AJBU cijjyGETGojiO+3VbQvYwc0rizxKrsCC7YQPshUFQsNUH20+C1i7giYLUKhr4erwtkMv lYFF391FNKSAyAyJYAdQ4seTxwo+CaPvld7yeWMzlakgPdLZeuvs2/AuOyYeVSOXxefv DA== Received: from userp3030.oracle.com (userp3030.oracle.com [156.151.31.80]) by aserp2130.oracle.com with ESMTP id 35wcuxt595-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Wed, 06 Jan 2021 20:39:35 +0000 Received: from pps.filterd (userp3030.oracle.com [127.0.0.1]) by userp3030.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 106KZbQA145512; Wed, 6 Jan 2021 20:39:35 GMT Received: from userv0121.oracle.com (userv0121.oracle.com [156.151.31.72]) by userp3030.oracle.com with ESMTP id 35w3g1jf2a-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 06 Jan 2021 20:39:35 +0000 Received: from abhmp0015.oracle.com (abhmp0015.oracle.com [141.146.116.21]) by userv0121.oracle.com (8.14.4/8.13.8) with ESMTP id 106KdYPh021660; Wed, 6 Jan 2021 20:39:34 GMT Received: from ca-ldom147.us.oracle.com (/10.129.68.131) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Wed, 06 Jan 2021 20:39:34 +0000 From: Bijan Mottahedeh To: axboe@kernel.dk, asml.silence@gmail.com, io-uring@vger.kernel.org Subject: [PATCH v4 13/13] io_uring: support buffer registration sharing Date: Wed, 6 Jan 2021 12:39:22 -0800 Message-Id: <1609965562-13569-14-git-send-email-bijan.mottahedeh@oracle.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1609965562-13569-1-git-send-email-bijan.mottahedeh@oracle.com> References: <1609965562-13569-1-git-send-email-bijan.mottahedeh@oracle.com> X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9856 signatures=668683 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 mlxscore=0 malwarescore=0 adultscore=0 phishscore=0 spamscore=0 mlxlogscore=999 suspectscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2101060117 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9856 signatures=668683 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 bulkscore=0 clxscore=1015 spamscore=0 impostorscore=0 priorityscore=1501 mlxscore=0 adultscore=0 mlxlogscore=999 lowpriorityscore=0 phishscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2101060117 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 ea708ec..08ca435e 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -8438,6 +8438,13 @@ 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; @@ -8446,6 +8453,11 @@ 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; + } + ret = io_rsrc_ref_quiesce(data, ctx); if (ret) return ret; @@ -8689,9 +8701,13 @@ 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), @@ -8756,9 +8772,17 @@ 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 io_mapped_ubuf *imu; @@ -8782,7 +8806,6 @@ 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; @@ -9833,6 +9856,55 @@ static struct file *io_uring_get_file(struct io_ring_ctx *ctx) return file; } +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) { @@ -9950,6 +10022,10 @@ 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; @@ -10030,6 +10106,7 @@ 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 b289ef8..3ad786a 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