From patchwork Wed Apr 22 09:56:48 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "gregkh@linuxfoundation.org" X-Patchwork-Id: 227114 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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 CAD90C5518C for ; Wed, 22 Apr 2020 10:49:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A881720787 for ; Wed, 22 Apr 2020 10:49:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587552552; bh=6SjgJX5uXF6l/fbulEwoIwAxqi/rr0lTgQYrB8uQ+Qo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=PAMJXng4GWBJuGRWv1e2M6YRWW5RXuP4l6RkX/6h8e9Z6fmj/G2jp//HTqM0SHilK /W9Hu7v5GgK4HMkJRP70hxElL0Dd75xDK4VThxFL9Ej1uS8P1ZTHqUVm4ri+qRKmUo f20HVcRFRQjDrbY8Kch2f7KF0K8gtp9kfMloyK84= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732076AbgDVKtE (ORCPT ); Wed, 22 Apr 2020 06:49:04 -0400 Received: from mail.kernel.org ([198.145.29.99]:47942 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728973AbgDVKNs (ORCPT ); Wed, 22 Apr 2020 06:13:48 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D225D2070B; Wed, 22 Apr 2020 10:13:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587550428; bh=6SjgJX5uXF6l/fbulEwoIwAxqi/rr0lTgQYrB8uQ+Qo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=WV2tFQ4ZYds5qbBbI0KP9uzzamRgHtyljbzn0i18fM9iZooDfIRtFnUiJanen+Ln0 WWtB/qa0pAJtPsQIBxi0dX3dbY35XjmljLxMhBIw+x7OG24ygIFfRHFsX9sNK1Pqr9 dSGQC/JhM8NTbstKlKlG04fW/1zUb4j1JlnmMtHs= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Andreas Dilger , Roman Gushchin , Theodore Tso Subject: [PATCH 4.19 04/64] ext4: use non-movable memory for superblock readahead Date: Wed, 22 Apr 2020 11:56:48 +0200 Message-Id: <20200422095013.021182139@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200422095008.799686511@linuxfoundation.org> References: <20200422095008.799686511@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Roman Gushchin commit d87f639258a6a5980183f11876c884931ad93da2 upstream. Since commit a8ac900b8163 ("ext4: use non-movable memory for the superblock") buffers for ext4 superblock were allocated using the sb_bread_unmovable() helper which allocated buffer heads out of non-movable memory blocks. It was necessarily to not block page migrations and do not cause cma allocation failures. However commit 85c8f176a611 ("ext4: preload block group descriptors") broke this by introducing pre-reading of the ext4 superblock. The problem is that __breadahead() is using __getblk() underneath, which allocates buffer heads out of movable memory. It resulted in page migration failures I've seen on a machine with an ext4 partition and a preallocated cma area. Fix this by introducing sb_breadahead_unmovable() and __breadahead_gfp() helpers which use non-movable memory for buffer head allocations and use them for the ext4 superblock readahead. Reviewed-by: Andreas Dilger Fixes: 85c8f176a611 ("ext4: preload block group descriptors") Signed-off-by: Roman Gushchin Link: https://lore.kernel.org/r/20200229001411.128010-1-guro@fb.com Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman --- fs/buffer.c | 11 +++++++++++ fs/ext4/inode.c | 2 +- fs/ext4/super.c | 2 +- include/linux/buffer_head.h | 8 ++++++++ 4 files changed, 21 insertions(+), 2 deletions(-) --- a/fs/buffer.c +++ b/fs/buffer.c @@ -1336,6 +1336,17 @@ void __breadahead(struct block_device *b } EXPORT_SYMBOL(__breadahead); +void __breadahead_gfp(struct block_device *bdev, sector_t block, unsigned size, + gfp_t gfp) +{ + struct buffer_head *bh = __getblk_gfp(bdev, block, size, gfp); + if (likely(bh)) { + ll_rw_block(REQ_OP_READ, REQ_RAHEAD, 1, &bh); + brelse(bh); + } +} +EXPORT_SYMBOL(__breadahead_gfp); + /** * __bread_gfp() - reads a specified block and returns the bh * @bdev: the block_device to read from --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -4690,7 +4690,7 @@ make_io: if (end > table) end = table; while (b <= end) - sb_breadahead(sb, b++); + sb_breadahead_unmovable(sb, b++); } /* --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -4207,7 +4207,7 @@ static int ext4_fill_super(struct super_ /* Pre-read the descriptors into the buffer cache */ for (i = 0; i < db_count; i++) { block = descriptor_loc(sb, logical_sb_block, i); - sb_breadahead(sb, block); + sb_breadahead_unmovable(sb, block); } for (i = 0; i < db_count; i++) { --- a/include/linux/buffer_head.h +++ b/include/linux/buffer_head.h @@ -189,6 +189,8 @@ struct buffer_head *__getblk_gfp(struct void __brelse(struct buffer_head *); void __bforget(struct buffer_head *); void __breadahead(struct block_device *, sector_t block, unsigned int size); +void __breadahead_gfp(struct block_device *, sector_t block, unsigned int size, + gfp_t gfp); struct buffer_head *__bread_gfp(struct block_device *, sector_t block, unsigned size, gfp_t gfp); void invalidate_bh_lrus(void); @@ -319,6 +321,12 @@ sb_breadahead(struct super_block *sb, se __breadahead(sb->s_bdev, block, sb->s_blocksize); } +static inline void +sb_breadahead_unmovable(struct super_block *sb, sector_t block) +{ + __breadahead_gfp(sb->s_bdev, block, sb->s_blocksize, 0); +} + static inline struct buffer_head * sb_getblk(struct super_block *sb, sector_t block) {