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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 72E63C433F5 for ; Thu, 26 May 2022 12:38:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236398AbiEZMiy (ORCPT ); Thu, 26 May 2022 08:38:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52946 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236058AbiEZMix (ORCPT ); Thu, 26 May 2022 08:38:53 -0400 Received: from out30-54.freemail.mail.aliyun.com (out30-54.freemail.mail.aliyun.com [115.124.30.54]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 29D342AC7B for ; Thu, 26 May 2022 05:38:51 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R231e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04394;MF=xiaoguang.wang@linux.alibaba.com;NM=1;PH=DS;RN=3;SR=0;TI=SMTPD_---0VESR4l-_1653568728; Received: from localhost(mailfrom:xiaoguang.wang@linux.alibaba.com fp:SMTPD_---0VESR4l-_1653568728) by smtp.aliyun-inc.com(127.0.0.1); Thu, 26 May 2022 20:38:48 +0800 From: Xiaoguang Wang To: io-uring@vger.kernel.org Cc: axboe@kernel.dk, asml.silence@gmail.com Subject: [RFC] io_uring: let IORING_OP_FILES_UPDATE support to choose fixed file slot Date: Thu, 26 May 2022 20:38:48 +0800 Message-Id: <20220526123848.18998-1-xiaoguang.wang@linux.alibaba.com> X-Mailer: git-send-email 2.14.4.44.g2045bb6 Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org One big issue with file registration feature is that it needs user space apps to maintain free slot info about io_uring's fixed file table, which really is a burden for development. Now since io_uring starts to choose free file slot for user space apps by using IORING_FILE_INDEX_ALLOC flag in accept or open operations, but they need app to uses direct accept or direct open, which as far as I know, some apps are not prepared to use direct accept or open yet. To support apps, who still need real fds, use registration feature easier, let IORING_OP_FILES_UPDATE support to choose fixed file slot, which will return free file slot in cqe->res. TODO list: Need to prepare liburing corresponding helpers. Signed-off-by: Xiaoguang Wang --- fs/io_uring.c | 50 ++++++++++++++++++++++++++++++++++--------- include/uapi/linux/io_uring.h | 1 + 2 files changed, 41 insertions(+), 10 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 9f1c682d7caf..d77e6bbec81c 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -680,6 +680,7 @@ struct io_rsrc_update { u64 arg; u32 nr_args; u32 offset; + u32 flags; }; struct io_fadvise { @@ -7970,14 +7971,23 @@ static int io_async_cancel(struct io_kiocb *req, unsigned int issue_flags) return 0; } +#define IORING_FILES_UPDATE_INDEX_ALLOC 1 + static int io_rsrc_update_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) { + u32 flags = READ_ONCE(sqe->files_update_flags); + if (unlikely(req->flags & (REQ_F_FIXED_FILE | REQ_F_BUFFER_SELECT))) return -EINVAL; - if (sqe->rw_flags || sqe->splice_fd_in) + if (sqe->splice_fd_in) + return -EINVAL; + if (flags & ~IORING_FILES_UPDATE_INDEX_ALLOC) + return -EINVAL; + if ((flags & IORING_FILES_UPDATE_INDEX_ALLOC) && READ_ONCE(sqe->len) != 1) return -EINVAL; + req->rsrc_update.flags = flags; req->rsrc_update.offset = READ_ONCE(sqe->off); req->rsrc_update.nr_args = READ_ONCE(sqe->len); if (!req->rsrc_update.nr_args) @@ -7990,18 +8000,38 @@ static int io_files_update(struct io_kiocb *req, unsigned int issue_flags) { struct io_ring_ctx *ctx = req->ctx; struct io_uring_rsrc_update2 up; + struct file *file; int ret; - up.offset = req->rsrc_update.offset; - up.data = req->rsrc_update.arg; - up.nr = 0; - up.tags = 0; - up.resv = 0; - up.resv2 = 0; + if (req->rsrc_update.flags & IORING_FILES_UPDATE_INDEX_ALLOC) { + int fd; - io_ring_submit_lock(ctx, issue_flags); - ret = __io_register_rsrc_update(ctx, IORING_RSRC_FILE, - &up, req->rsrc_update.nr_args); + if (copy_from_user(&fd, (int *)req->rsrc_update.arg, sizeof(fd))) { + ret = -EFAULT; + goto out; + } + file = fget(fd); + if (!file) { + ret = -EBADF; + goto out; + } + ret = io_fixed_fd_install(req, issue_flags, file, + IORING_FILE_INDEX_ALLOC); + } else { + up.offset = req->rsrc_update.offset; + up.data = req->rsrc_update.arg; + up.nr = 0; + up.tags = 0; + up.resv = 0; + up.resv2 = 0; + + io_ring_submit_lock(ctx, issue_flags); + ret = __io_register_rsrc_update(ctx, IORING_RSRC_FILE, + &up, req->rsrc_update.nr_args); + io_ring_submit_unlock(ctx, issue_flags); + } + +out: io_ring_submit_unlock(ctx, issue_flags); if (ret < 0) diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h index 53e7dae92e42..b4af01d56d7c 100644 --- a/include/uapi/linux/io_uring.h +++ b/include/uapi/linux/io_uring.h @@ -47,6 +47,7 @@ struct io_uring_sqe { __u32 unlink_flags; __u32 hardlink_flags; __u32 xattr_flags; + __u32 files_update_flags; }; __u64 user_data; /* data to be passed back at completion time */ /* pack this to avoid bogus arm OABI complaints */ -- 2.14.4.44.g2045bb6