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 D9ACDC433EF for ; Mon, 11 Apr 2022 07:44:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244576AbiDKHqv (ORCPT ); Mon, 11 Apr 2022 03:46:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49302 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240455AbiDKHqq (ORCPT ); Mon, 11 Apr 2022 03:46:46 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B5E2C5F88 for ; Mon, 11 Apr 2022 00:44:31 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 73D30B80ED6 for ; Mon, 11 Apr 2022 07:44:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CBD36C385A5; Mon, 11 Apr 2022 07:44:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1649663069; bh=khgD3luToPekWrK2kxejVSS/gcSulswd+22g/lWf+4A=; h=Subject:To:Cc:From:Date:From; b=sbzPbZdwrzCFAOr74HFCu/8R9ZJP0kHRGzBc3S3gBlQV9D8VroPHJqS8t4dwq1ZNo 1fgqwt6wK+rNHlbnlMfcc0dWdYF0VJrqvSkq+qzYXglPjWsv2vpwPgsaQXs8wYUJ7e FjbyMyLNEt3OOGtW7tp6CpXx2DEJlL3KbgIePoe0= Subject: FAILED: patch "[PATCH] io_uring: defer file assignment" failed to apply to 5.17-stable tree To: axboe@kernel.dk Cc: From: Date: Mon, 11 Apr 2022 09:44:16 +0200 Message-ID: <16496630567985@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch below does not apply to the 5.17-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 6bf9c47a398911e0ab920e362115153596c80432 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Tue, 29 Mar 2022 10:10:08 -0600 Subject: [PATCH] io_uring: defer file assignment If an application uses direct open or accept, it knows in advance what direct descriptor value it will get as it picks it itself. This allows combined requests such as: sqe = io_uring_get_sqe(ring); io_uring_prep_openat_direct(sqe, ..., file_slot); sqe->flags |= IOSQE_IO_LINK | IOSQE_CQE_SKIP_SUCCESS; sqe = io_uring_get_sqe(ring); io_uring_prep_read(sqe,file_slot, buf, buf_size, 0); sqe->flags |= IOSQE_FIXED_FILE; io_uring_submit(ring); where we prepare both a file open and read, and only get a completion event for the read when both have completed successfully. Currently links are fully prepared before the head is issued, but that fails if the dependent link needs a file assigned that isn't valid until the head has completed. Conversely, if the same chain is performed but the fixed file slot is already valid, then we would be unexpectedly returning data from the old file slot rather than the newly opened one. Make sure we're consistent here. Allow deferral of file setup, which makes this documented case work. Cc: stable@vger.kernel.org # v5.15+ Signed-off-by: Jens Axboe diff --git a/fs/io-wq.h b/fs/io-wq.h index dbecd27656c7..04d374e65e54 100644 --- a/fs/io-wq.h +++ b/fs/io-wq.h @@ -155,6 +155,7 @@ struct io_wq_work_node *wq_stack_extract(struct io_wq_work_node *stack) struct io_wq_work { struct io_wq_work_node list; unsigned flags; + int fd; }; static inline struct io_wq_work *wq_next_work(struct io_wq_work *work) diff --git a/fs/io_uring.c b/fs/io_uring.c index 398128db9728..bdc090fec29c 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -7240,6 +7240,23 @@ static void io_clean_op(struct io_kiocb *req) req->flags &= ~IO_REQ_CLEAN_FLAGS; } +static bool io_assign_file(struct io_kiocb *req, unsigned int issue_flags) +{ + if (req->file || !io_op_defs[req->opcode].needs_file) + return true; + + if (req->flags & REQ_F_FIXED_FILE) + req->file = io_file_get_fixed(req, req->work.fd, issue_flags); + else + req->file = io_file_get_normal(req, req->work.fd); + if (req->file) + return true; + + req_set_fail(req); + req->result = -EBADF; + return false; +} + static int io_issue_sqe(struct io_kiocb *req, unsigned int issue_flags) { const struct cred *creds = NULL; @@ -7250,6 +7267,8 @@ static int io_issue_sqe(struct io_kiocb *req, unsigned int issue_flags) if (!io_op_defs[req->opcode].audit_skip) audit_uring_entry(req->opcode); + if (unlikely(!io_assign_file(req, issue_flags))) + return -EBADF; switch (req->opcode) { case IORING_OP_NOP: @@ -7394,10 +7413,11 @@ static struct io_wq_work *io_wq_free_work(struct io_wq_work *work) static void io_wq_submit_work(struct io_wq_work *work) { struct io_kiocb *req = container_of(work, struct io_kiocb, work); + const struct io_op_def *def = &io_op_defs[req->opcode]; unsigned int issue_flags = IO_URING_F_UNLOCKED; bool needs_poll = false; struct io_kiocb *timeout; - int ret = 0; + int ret = 0, err = -ECANCELED; /* one will be dropped by ->io_free_work() after returning to io-wq */ if (!(req->flags & REQ_F_REFCOUNT)) @@ -7409,14 +7429,18 @@ static void io_wq_submit_work(struct io_wq_work *work) if (timeout) io_queue_linked_timeout(timeout); + if (!io_assign_file(req, issue_flags)) { + err = -EBADF; + work->flags |= IO_WQ_WORK_CANCEL; + } + /* either cancelled or io-wq is dying, so don't touch tctx->iowq */ if (work->flags & IO_WQ_WORK_CANCEL) { - io_req_task_queue_fail(req, -ECANCELED); + io_req_task_queue_fail(req, err); return; } if (req->flags & REQ_F_FORCE_ASYNC) { - const struct io_op_def *def = &io_op_defs[req->opcode]; bool opcode_poll = def->pollin || def->pollout; if (opcode_poll && file_can_poll(req->file)) { @@ -7749,6 +7773,8 @@ static int io_init_req(struct io_ring_ctx *ctx, struct io_kiocb *req, if (io_op_defs[opcode].needs_file) { struct io_submit_state *state = &ctx->submit_state; + req->work.fd = READ_ONCE(sqe->fd); + /* * Plug now if we have more than 2 IO left after this, and the * target is potentially a read/write to block based storage. @@ -7758,13 +7784,6 @@ static int io_init_req(struct io_ring_ctx *ctx, struct io_kiocb *req, state->need_plug = false; blk_start_plug_nr_ios(&state->plug, state->submit_nr); } - - if (req->flags & REQ_F_FIXED_FILE) - req->file = io_file_get_fixed(req, READ_ONCE(sqe->fd), 0); - else - req->file = io_file_get_normal(req, READ_ONCE(sqe->fd)); - if (unlikely(!req->file)) - return -EBADF; } personality = READ_ONCE(sqe->personality);