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=-12.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 0B005C5517A for ; Thu, 22 Oct 2020 23:14:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AA9C02245F for ; Thu, 22 Oct 2020 23:14:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="mnfr1R+D" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S373280AbgJVXOW (ORCPT ); Thu, 22 Oct 2020 19:14:22 -0400 Received: from userp2120.oracle.com ([156.151.31.85]:50542 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S373216AbgJVXOW (ORCPT ); Thu, 22 Oct 2020 19:14:22 -0400 Received: from pps.filterd (userp2120.oracle.com [127.0.0.1]) by userp2120.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 09MNEJ9K096631; Thu, 22 Oct 2020 23:14:19 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=obsQ40lnz8yMkoUPVtjr6tH34PKqEmFwZDzeQacrjxY=; b=mnfr1R+Dz0RtEzpc+jmE76UQ4Jv2Bk0fEMyxOF/MUbcVrqWsi6IndQLxu7Tmr3adDVeH rPDxCVgO8yvy0jY1V1sOGx+suBiMArXHezW73Ohnh2W3l3tePjH8DPsl40t9uF/kuLps 4JDB+GLkEIFvNcPOlIW5lPuV0qn17sK9bSuycu6WOwiuzUsIwXxGmAwd8g05asZsc5Xl Gcnuk3XD5ZNSC8Qcria+oAIyVoLVjCttrNcwbmC5mlK3Pu5Fldp/6XA71Gb8dWl54EFu CdyO8MvFLVJJj6XOjjQQw2Rkh6vZU4eCT/ENiqYGRFsANvUoq8+hDNDgPB20LShaQZG/ QQ== Received: from aserp3020.oracle.com (aserp3020.oracle.com [141.146.126.70]) by userp2120.oracle.com with ESMTP id 34ak16rw44-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Thu, 22 Oct 2020 23:14:19 +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 09MN5joj095169; Thu, 22 Oct 2020 23:14:18 GMT Received: from userv0121.oracle.com (userv0121.oracle.com [156.151.31.72]) by aserp3020.oracle.com with ESMTP id 348ah1dcj6-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 22 Oct 2020 23:14:18 +0000 Received: from abhmp0010.oracle.com (abhmp0010.oracle.com [141.146.116.16]) by userv0121.oracle.com (8.14.4/8.13.8) with ESMTP id 09MNEHil028654; Thu, 22 Oct 2020 23:14:17 GMT Received: from ca-ldom147.us.oracle.com (/10.129.68.131) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 22 Oct 2020 16:14:17 -0700 From: Bijan Mottahedeh To: axboe@kernel.dk, io-uring@vger.kernel.org Subject: [RFC 8/8] io_uring: support buffer registration sharing Date: Thu, 22 Oct 2020 16:14:03 -0700 Message-Id: <1603408443-51303-9-git-send-email-bijan.mottahedeh@oracle.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1603408443-51303-1-git-send-email-bijan.mottahedeh@oracle.com> References: <1603408443-51303-1-git-send-email-bijan.mottahedeh@oracle.com> X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9782 signatures=668682 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 adultscore=0 mlxscore=0 phishscore=0 malwarescore=0 spamscore=0 suspectscore=2 bulkscore=0 mlxlogscore=999 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2010220148 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9782 signatures=668682 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 bulkscore=0 phishscore=0 priorityscore=1501 clxscore=1015 malwarescore=0 mlxscore=0 adultscore=0 lowpriorityscore=0 impostorscore=0 spamscore=0 mlxlogscore=999 suspectscore=2 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2010220149 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 | 140 +++++++++++++++++++++++++++++++++++------- include/uapi/linux/io_uring.h | 2 + 2 files changed, 119 insertions(+), 23 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index a8d8871..050f18e 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -8134,6 +8134,12 @@ 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; +} + static int io_sqe_buffers_unregister(struct io_ring_ctx *ctx) { struct fixed_rsrc_data *data = ctx->buf_data; @@ -8142,6 +8148,12 @@ 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); + ctx->nr_user_bufs = 0; + return 0; + } + spin_lock(&data->lock); if (!list_empty(&data->ref_list)) ref_node = list_first_entry(&data->ref_list, @@ -8388,46 +8400,67 @@ static int io_alloc_buf_tables(struct fixed_rsrc_data *buf_data, return 1; } +static struct fixed_rsrc_data *io_alloc_buf_data(struct io_ring_ctx *ctx) +{ + struct fixed_rsrc_data *buf_data; + + buf_data = kzalloc(sizeof(*buf_data), GFP_KERNEL); + if (!buf_data) + return ERR_PTR(-ENOMEM); + + buf_data->ctx = ctx; + init_completion(&buf_data->done); + INIT_LIST_HEAD(&buf_data->ref_list); + spin_lock_init(&buf_data->lock); + + if (percpu_ref_init(&buf_data->refs, io_rsrc_ref_kill, + PERCPU_REF_ALLOW_REINIT, GFP_KERNEL)) { + kfree(buf_data); + return ERR_PTR(-ENOMEM); + } + + return buf_data; +} + +static void io_free_buf_data(struct io_ring_ctx *ctx) +{ + percpu_ref_exit(&ctx->buf_data->refs); + kfree(ctx->buf_data->table); + kfree(ctx->buf_data); +} + static struct fixed_rsrc_data *io_buffers_map_alloc(struct io_ring_ctx *ctx, unsigned int nr_args) { - unsigned nr_tables; struct fixed_rsrc_data *buf_data; + unsigned nr_tables; int ret = -ENOMEM; - if (ctx->buf_data) + if (ctx->nr_user_bufs) return ERR_PTR(-EBUSY); if (!nr_args || nr_args > IORING_MAX_FIXED_BUFS) return ERR_PTR(-EINVAL); - buf_data = kzalloc(sizeof(*ctx->buf_data), GFP_KERNEL); - if (!buf_data) - return ERR_PTR(-ENOMEM); - buf_data->ctx = ctx; - init_completion(&buf_data->done); - INIT_LIST_HEAD(&buf_data->ref_list); - spin_lock_init(&buf_data->lock); + if (ctx->buf_data) + buf_data = ctx->buf_data; + else { + buf_data = io_alloc_buf_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), + buf_data->table = kcalloc(nr_tables, sizeof(struct fixed_rsrc_table), GFP_KERNEL); if (!buf_data->table) - goto out_free; - - if (percpu_ref_init(&buf_data->refs, io_rsrc_ref_kill, - PERCPU_REF_ALLOW_REINIT, GFP_KERNEL)) - goto out_free; + goto out; if (io_alloc_buf_tables(buf_data, nr_tables, nr_args)) - goto out_ref; + goto out; return buf_data; - -out_ref: - percpu_ref_exit(&buf_data->refs); -out_free: - kfree(buf_data->table); - kfree(buf_data); +out: + io_free_buf_data(ctx); return ERR_PTR(ret); } @@ -8515,9 +8548,17 @@ static int io_sqe_buffers_register(struct io_ring_ctx *ctx, void __user *arg, struct fixed_rsrc_ref_node *ref_node; struct fixed_rsrc_data *buf_data; + 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; @@ -8545,7 +8586,6 @@ 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; @@ -9623,6 +9663,55 @@ 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 = io_alloc_buf_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) { @@ -9737,6 +9826,10 @@ 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; @@ -9807,6 +9900,7 @@ 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 8f92555..1079048 100644 --- a/include/uapi/linux/io_uring.h +++ b/include/uapi/linux/io_uring.h @@ -99,6 +99,8 @@ 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