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=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,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 42F20C55186 for ; Wed, 22 Apr 2020 10:36:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1FCCA2075A for ; Wed, 22 Apr 2020 10:36:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587551804; bh=9le1PvFkKlbTxjWl55RK+nnvYIn4LST6W/S4enHx7iU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=RnVr5rn+3K4ykW5Z6Q0xjgsPfv5fWO100J2AEISQQxQ7A5ti458WLUBFg/IyrEELR ThKKj29ACFk7ksMnXysDOlgS8seevVCEFYVmwd6Lzt2RxMXY51KrnJI6VbCSNmdUFc IJTuUPoiGtAxlgltsLz1DNlbXBu65vUD5Mox0o6s= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730229AbgDVKgn (ORCPT ); Wed, 22 Apr 2020 06:36:43 -0400 Received: from mail.kernel.org ([198.145.29.99]:59146 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730226AbgDVKWv (ORCPT ); Wed, 22 Apr 2020 06:22:51 -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 07AE72075A; Wed, 22 Apr 2020 10:22:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587550970; bh=9le1PvFkKlbTxjWl55RK+nnvYIn4LST6W/S4enHx7iU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=z0LKIRzKLL8NcqI09LDHsDDIKOVQlx+NolINRMOebn9SGFat+hgQdwd9z7Glt6iI9 ffhTwoTL4TZsPg/xdacOwGoNHd2bzJgfQl2wMeH0Zam/guyziDLxU4F9w54ZnwaA+o bxGMUtJixkPZEGE5yG8gS5SbXjKSmd/qN3lJV9OI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Sahitya Tummala , Chao Yu , Jaegeuk Kim , Sasha Levin Subject: [PATCH 5.6 048/166] f2fs: fix the panic in do_checkpoint() Date: Wed, 22 Apr 2020 11:56:15 +0200 Message-Id: <20200422095054.239181541@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200422095047.669225321@linuxfoundation.org> References: <20200422095047.669225321@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Sahitya Tummala [ Upstream commit bf22c3cc8ce71454dddd772284773306a68031d8 ] There could be a scenario where f2fs_sync_meta_pages() will not ensure that all F2FS_DIRTY_META pages are submitted for IO. Thus, resulting in the below panic in do_checkpoint() - f2fs_bug_on(sbi, get_pages(sbi, F2FS_DIRTY_META) && !f2fs_cp_error(sbi)); This can happen in a low-memory condition, where shrinker could also be doing the writepage operation (stack shown below) at the same time when checkpoint is running on another core. schedule down_write f2fs_submit_page_write -> by this time, this page in page cache is tagged as PAGECACHE_TAG_WRITEBACK and PAGECACHE_TAG_DIRTY is cleared, due to which f2fs_sync_meta_pages() cannot sync this page in do_checkpoint() path. f2fs_do_write_meta_page __f2fs_write_meta_page f2fs_write_meta_page shrink_page_list shrink_inactive_list shrink_node_memcg shrink_node kswapd Signed-off-by: Sahitya Tummala Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Sasha Levin --- fs/f2fs/checkpoint.c | 16 +++++++--------- fs/f2fs/f2fs.h | 2 +- fs/f2fs/super.c | 2 +- 3 files changed, 9 insertions(+), 11 deletions(-) diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c index 44e84ac5c9411..9c88fb3d255a2 100644 --- a/fs/f2fs/checkpoint.c +++ b/fs/f2fs/checkpoint.c @@ -1250,20 +1250,20 @@ static void unblock_operations(struct f2fs_sb_info *sbi) f2fs_unlock_all(sbi); } -void f2fs_wait_on_all_pages_writeback(struct f2fs_sb_info *sbi) +void f2fs_wait_on_all_pages(struct f2fs_sb_info *sbi, int type) { DEFINE_WAIT(wait); for (;;) { prepare_to_wait(&sbi->cp_wait, &wait, TASK_UNINTERRUPTIBLE); - if (!get_pages(sbi, F2FS_WB_CP_DATA)) + if (!get_pages(sbi, type)) break; if (unlikely(f2fs_cp_error(sbi))) break; - io_schedule_timeout(5*HZ); + io_schedule_timeout(HZ/50); } finish_wait(&sbi->cp_wait, &wait); } @@ -1384,8 +1384,6 @@ static int do_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc) /* Flush all the NAT/SIT pages */ f2fs_sync_meta_pages(sbi, META, LONG_MAX, FS_CP_META_IO); - f2fs_bug_on(sbi, get_pages(sbi, F2FS_DIRTY_META) && - !f2fs_cp_error(sbi)); /* * modify checkpoint @@ -1493,11 +1491,11 @@ static int do_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc) /* Here, we have one bio having CP pack except cp pack 2 page */ f2fs_sync_meta_pages(sbi, META, LONG_MAX, FS_CP_META_IO); - f2fs_bug_on(sbi, get_pages(sbi, F2FS_DIRTY_META) && - !f2fs_cp_error(sbi)); + /* Wait for all dirty meta pages to be submitted for IO */ + f2fs_wait_on_all_pages(sbi, F2FS_DIRTY_META); /* wait for previous submitted meta pages writeback */ - f2fs_wait_on_all_pages_writeback(sbi); + f2fs_wait_on_all_pages(sbi, F2FS_WB_CP_DATA); /* flush all device cache */ err = f2fs_flush_device_cache(sbi); @@ -1506,7 +1504,7 @@ static int do_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc) /* barrier and flush checkpoint cp pack 2 page if it can */ commit_checkpoint(sbi, ckpt, start_blk); - f2fs_wait_on_all_pages_writeback(sbi); + f2fs_wait_on_all_pages(sbi, F2FS_WB_CP_DATA); /* * invalidate intermediate page cache borrowed from meta inode which are diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index 5355be6b6755c..d39f5de114208 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -3308,7 +3308,7 @@ int f2fs_get_valid_checkpoint(struct f2fs_sb_info *sbi); void f2fs_update_dirty_page(struct inode *inode, struct page *page); void f2fs_remove_dirty_inode(struct inode *inode); int f2fs_sync_dirty_inodes(struct f2fs_sb_info *sbi, enum inode_type type); -void f2fs_wait_on_all_pages_writeback(struct f2fs_sb_info *sbi); +void f2fs_wait_on_all_pages(struct f2fs_sb_info *sbi, int type); int f2fs_write_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc); void f2fs_init_ino_entry_info(struct f2fs_sb_info *sbi); int __init f2fs_create_checkpoint_caches(void); diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c index 65a7a432dfee2..686f5402660ed 100644 --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -1172,7 +1172,7 @@ static void f2fs_put_super(struct super_block *sb) /* our cp_error case, we can wait for any writeback page */ f2fs_flush_merged_writes(sbi); - f2fs_wait_on_all_pages_writeback(sbi); + f2fs_wait_on_all_pages(sbi, F2FS_WB_CP_DATA); f2fs_bug_on(sbi, sbi->fsync_node_num); -- 2.20.1