From patchwork Wed Mar 10 13:23:20 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 397429 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, URIBL_BLOCKED, 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 AB1FCC433E6 for ; Wed, 10 Mar 2021 13:25:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6AEF164FDC for ; Wed, 10 Mar 2021 13:25:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232856AbhCJNYh (ORCPT ); Wed, 10 Mar 2021 08:24:37 -0500 Received: from mail.kernel.org ([198.145.29.99]:45374 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232718AbhCJNYH (ORCPT ); Wed, 10 Mar 2021 08:24:07 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 45D0964FDA; Wed, 10 Mar 2021 13:24:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1615382647; bh=HOnZyrl+e1tKtDOdwbOp+TkVF0JaTyTbnFXkUxaz5pw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=eWfS5VQQQwE5dZ+MLRVVtFpwzt5eJXOo4bgjDUwZKUdk4bTbXj6zZW/DCCO6m94ZH 0NAo3p59Y0Vf5YBZl1rQcgFJgMKyGhnkQOAOG4OjoAHJhhvtCMjrKWZjeR5VJj2VKb bQ53vN1/Ph+HUiYNOzbN9NwYSj5Ok+hE+OBgeCa8= From: gregkh@linuxfoundation.org To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg Kroah-Hartman , Jens Axboe , Pavel Begunkov Subject: [PATCH 5.11 07/36] io_uring: get rid of intermediate IORING_OP_CLOSE stage Date: Wed, 10 Mar 2021 14:23:20 +0100 Message-Id: <20210310132320.752862116@linuxfoundation.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210310132320.510840709@linuxfoundation.org> References: <20210310132320.510840709@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Greg Kroah-Hartman From: Jens Axboe commit 9eac1904d3364254d622bf2c771c4f85cd435fc2 upstream We currently split the close into two, in case we have a ->flush op that we can't safely handle from non-blocking context. This requires us to flag the op as uncancelable if we do need to punt it async, and that means special handling for just this op type. Use __close_fd_get_file() and grab the files lock so we can get the file and check if we need to go async in one atomic operation. That gets rid of the need for splitting this into two steps, and hence the need for IO_WQ_WORK_NO_CANCEL. Signed-off-by: Jens Axboe Signed-off-by: Pavel Begunkov Signed-off-by: Greg Kroah-Hartman --- fs/io_uring.c | 64 +++++++++++++++++++++++++++++++--------------------------- 1 file changed, 35 insertions(+), 29 deletions(-) --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -411,7 +411,6 @@ struct io_poll_remove { struct io_close { struct file *file; - struct file *put_file; int fd; }; @@ -908,8 +907,6 @@ static const struct io_op_def io_op_defs IO_WQ_WORK_FS | IO_WQ_WORK_MM, }, [IORING_OP_CLOSE] = { - .needs_file = 1, - .needs_file_no_error = 1, .work_flags = IO_WQ_WORK_FILES | IO_WQ_WORK_BLKCG, }, [IORING_OP_FILES_UPDATE] = { @@ -4473,13 +4470,6 @@ static int io_statx(struct io_kiocb *req static int io_close_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) { - /* - * If we queue this for async, it must not be cancellable. That would - * leave the 'file' in an undeterminate state, and here need to modify - * io_wq_work.flags, so initialize io_wq_work firstly. - */ - io_req_init_async(req); - if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) return -EINVAL; if (sqe->ioprio || sqe->off || sqe->addr || sqe->len || @@ -4489,43 +4479,59 @@ static int io_close_prep(struct io_kiocb return -EBADF; req->close.fd = READ_ONCE(sqe->fd); - if ((req->file && req->file->f_op == &io_uring_fops)) - return -EBADF; - - req->close.put_file = NULL; return 0; } static int io_close(struct io_kiocb *req, bool force_nonblock, struct io_comp_state *cs) { + struct files_struct *files = current->files; struct io_close *close = &req->close; + struct fdtable *fdt; + struct file *file; int ret; - /* might be already done during nonblock submission */ - if (!close->put_file) { - ret = close_fd_get_file(close->fd, &close->put_file); - if (ret < 0) - return (ret == -ENOENT) ? -EBADF : ret; + file = NULL; + ret = -EBADF; + spin_lock(&files->file_lock); + fdt = files_fdtable(files); + if (close->fd >= fdt->max_fds) { + spin_unlock(&files->file_lock); + goto err; + } + file = fdt->fd[close->fd]; + if (!file) { + spin_unlock(&files->file_lock); + goto err; + } + + if (file->f_op == &io_uring_fops) { + spin_unlock(&files->file_lock); + file = NULL; + goto err; } /* if the file has a flush method, be safe and punt to async */ - if (close->put_file->f_op->flush && force_nonblock) { - /* not safe to cancel at this point */ - req->work.flags |= IO_WQ_WORK_NO_CANCEL; - /* was never set, but play safe */ - req->flags &= ~REQ_F_NOWAIT; - /* avoid grabbing files - we don't need the files */ - req->flags |= REQ_F_NO_FILE_TABLE; + if (file->f_op->flush && force_nonblock) { + spin_unlock(&files->file_lock); return -EAGAIN; } + ret = __close_fd_get_file(close->fd, &file); + spin_unlock(&files->file_lock); + if (ret < 0) { + if (ret == -ENOENT) + ret = -EBADF; + goto err; + } + /* No ->flush() or already async, safely close from here */ - ret = filp_close(close->put_file, req->work.identity->files); + ret = filp_close(file, current->files); +err: if (ret < 0) req_set_fail_links(req); - fput(close->put_file); - close->put_file = NULL; + if (file) + fput(file); __io_req_complete(req, ret, 0, cs); return 0; }