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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, 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 AC7C0C606AC for ; Mon, 8 Jul 2019 12:41:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8AD2C20665 for ; Mon, 8 Jul 2019 12:41:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730853AbfGHMk7 (ORCPT ); Mon, 8 Jul 2019 08:40:59 -0400 Received: from mout.kundenserver.de ([212.227.126.187]:35867 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727544AbfGHMk7 (ORCPT ); Mon, 8 Jul 2019 08:40:59 -0400 Received: from threadripper.lan ([149.172.19.189]) by mrelayeu.kundenserver.de (mreue012 [212.227.15.129]) with ESMTPA (Nemesis) id 1MODeL-1i8QoA0AXp-00OZfs; Mon, 08 Jul 2019 14:40:23 +0200 From: Arnd Bergmann To: Chris Mason , Josef Bacik , David Sterba Cc: Arnd Bergmann , Johannes Thumshirn , Nikolay Borisov , Andrea Gelmini , Qu Wenruo , Liu Bo , linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] btrfs: reduce stack usage for btrfsic_process_written_block Date: Mon, 8 Jul 2019 14:40:09 +0200 Message-Id: <20190708124019.3374246-1-arnd@arndb.de> X-Mailer: git-send-email 2.20.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Provags-ID: V03:K1:8sOT6VQRiNZC3jnSu4L3RMXdtdrKeV0mXzADeVPdh87PGDVia0j cZ7K+7QQbnacsI/brzzT4cGLeui4MFzcdlcsG/Tpmj1j1wAmNJ/wVoz9FRpZModKOFBjj2Q CnedBnvnsjIsGn0hJlExKEw/fB4ylt3TtRsAG/eupJh0y2ru/rLrUzSPnD2bbng0PDHBQ8r Ux0R6kwhmV6oCjpF5YfPQ== X-UI-Out-Filterresults: notjunk:1;V03:K0:eFrmzYnB2jc=:PqiTgWnbJy5Ai0g76Ilnfs kczS6VYts7jyh4xHlK5BmvFxLit8H4LsbxW9vvXAcEyexUS4s25e0xthcTnYMCjIL2QUbb0sn qigWfvOX1bV2ODxd3laivsHJnn1Vk3MrP7gnyvk3fBLBCMrAlEFvqcW4Q+7ONUvcQiB7ZhUOP r9dGSKEYD+oqtRCN4cPj21022GkjbtmQ+GoztNE1/JaxhBk0bxxSGnGmXXomUPfBpQJ65ojwm A7PDqFmkM2s0MbDberXHqmwVt7cM+n73md0c1EyjwTn7x63ZupBpAwH+0x2VoRxzhNsuKRlmV 1FXcyVyPVZmObtZwt9PdWWdEfr/DBDbZphob4UWdq6xLGu1k3E9YmzX4SsoxIgHT0ejdI5Q21 J20UjXS0XG/+qZtPAGyDA2z8WmPGnzouLksywVYKSqqO3OzH4WyRNLbyGTcERTvIAnkmS2bHq Ps4MnRfz7rwkmHny1bmzlg6MH6GbqA/Ng79IvBixGAwB6d11wZb41yVP5+TZZYypgjnuSEutI S+/8U6qO7Jv8TPSl9s6CJjWeq8BQ4mY86MGWt+4iabNBjW4C/MRyjirMcseyeQNcYNe+E5PhZ ybltCMNVyjMhjMnC0k89W//Doa0MGHdcGbu1yjmtLmt2sRF5jFgTOWzF4GhPkeBGubPCYmX5K whjt6Z5IiLz3IUMpvS+llVzUHLXRE4/1p6nO9m8vkpGDDI2wcVsLzDStaYi4tLp3fGipDABqe hE63Q7hIZVfzSl+SpKjrzWWH6xbQq6xpF27Gug== Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org btrfsic_process_written_block() cals btrfsic_process_metablock(), which has a fairly large stack usage due to the btrfsic_stack_frame variable. It also calls btrfsic_test_for_metadata(), which now needs several hundreds of bytes for its SHASH_DESC_ON_STACK(). In some configurations, we end up with both functions on the same stack, and gcc warns about the excessive stack usage that might cause the available stack space to run out: fs/btrfs/check-integrity.c:1743:13: error: stack frame size of 1152 bytes in function 'btrfsic_process_written_block' [-Werror,-Wframe-larger-than=] Marking both child functions as noinline_for_stack helps because this guarantees that the large variables are not on the same stack frame. Fixes: d5178578bcd4 ("btrfs: directly call into crypto framework for checksumming") Signed-off-by: Arnd Bergmann --- fs/btrfs/check-integrity.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/fs/btrfs/check-integrity.c b/fs/btrfs/check-integrity.c index 81a9731959a9..0b52ab4cb964 100644 --- a/fs/btrfs/check-integrity.c +++ b/fs/btrfs/check-integrity.c @@ -940,7 +940,7 @@ static void btrfsic_stack_frame_free(struct btrfsic_stack_frame *sf) kfree(sf); } -static int btrfsic_process_metablock( +static noinline_for_stack int btrfsic_process_metablock( struct btrfsic_state *state, struct btrfsic_block *const first_block, struct btrfsic_block_data_ctx *const first_block_ctx, @@ -1706,8 +1706,9 @@ static void btrfsic_dump_database(struct btrfsic_state *state) * Test whether the disk block contains a tree block (leaf or node) * (note that this test fails for the super block) */ -static int btrfsic_test_for_metadata(struct btrfsic_state *state, - char **datav, unsigned int num_pages) +static noinline_for_stack int btrfsic_test_for_metadata( + struct btrfsic_state *state, + char **datav, unsigned int num_pages) { struct btrfs_fs_info *fs_info = state->fs_info; SHASH_DESC_ON_STACK(shash, fs_info->csum_shash); -- 2.20.0