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=-9.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,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 17EE0C35242 for ; Mon, 17 Feb 2020 03:44:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DC82F206E2 for ; Mon, 17 Feb 2020 03:44:19 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="key not found in DNS" (0-bit key) header.d=mg.codeaurora.org header.i=@mg.codeaurora.org header.b="rhzuMNwP" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727789AbgBQDoS (ORCPT ); Sun, 16 Feb 2020 22:44:18 -0500 Received: from mail26.static.mailgun.info ([104.130.122.26]:34694 "EHLO mail26.static.mailgun.info" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726485AbgBQDoS (ORCPT ); Sun, 16 Feb 2020 22:44:18 -0500 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1581911057; h=Message-Id: Date: Subject: Cc: To: From: Sender; bh=oLwBoEwcv3fRTqQTxsGwQy5RClyVuVnp1M8eCRgAIbM=; b=rhzuMNwPF+L1V1OzdH+H2vxVM4RaDsKJEXNMi39S4Q5SJUTqQUD+mYfErn2i6AMpl4/i4xIt QYmXj+RwLJFVAw069/P1D9bJ3HhVHLhVIUWyJ52k18NA0h+XgkHex9BlDPKeB0uO5xzpB5KE tmyQ4sEd430EwBdxdSj+iYTM4ck= X-Mailgun-Sending-Ip: 104.130.122.26 X-Mailgun-Sid: WyI0MWYwYSIsICJsaW51eC1rZXJuZWxAdmdlci5rZXJuZWwub3JnIiwgImJlOWU0YSJd Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by mxa.mailgun.org with ESMTP id 5e4a0c00.7fb06baf0688-smtp-out-n01; Mon, 17 Feb 2020 03:44:00 -0000 (UTC) Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 1271EC4479D; Mon, 17 Feb 2020 03:44:00 +0000 (UTC) Received: from codeaurora.org (blr-c-bdr-fw-01_GlobalNAT_AllZones-Outside.qualcomm.com [103.229.19.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: stummala) by smtp.codeaurora.org (Postfix) with ESMTPSA id 4E334C43383; Mon, 17 Feb 2020 03:43:56 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 4E334C43383 Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; spf=none smtp.mailfrom=stummala@codeaurora.org From: Sahitya Tummala To: Jaegeuk Kim , Chao Yu , linux-f2fs-devel@lists.sourceforge.net Cc: Sahitya Tummala , linux-kernel@vger.kernel.org Subject: [PATCH V2] f2fs: fix the panic in do_checkpoint() Date: Mon, 17 Feb 2020 09:13:44 +0530 Message-Id: <1581911024-23660-1-git-send-email-stummala@codeaurora.org> X-Mailer: git-send-email 1.9.1 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- v2: - changed the io_schedule_timeout to HZ/50. fs/f2fs/checkpoint.c | 18 +++++++++--------- fs/f2fs/f2fs.h | 2 +- fs/f2fs/super.c | 2 +- 3 files changed, 11 insertions(+), 11 deletions(-) diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c index ffdaba0..d5601cc 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 +1384,8 @@ 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)); + /* Wait for all dirty meta pages to be submitted for IO */ + f2fs_wait_on_all_pages(sbi, F2FS_DIRTY_META); /* * modify checkpoint @@ -1493,11 +1493,11 @@ 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 +1506,7 @@ 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 diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index 5a888a0..b0e0535 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -3196,7 +3196,7 @@ bool f2fs_is_dirty_device(struct f2fs_sb_info *sbi, nid_t ino, 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 5111e1f..084633b 100644 --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -1105,7 +1105,7 @@ 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); -- Qualcomm India Private Limited, on behalf of Qualcomm Innovation Center, Inc. Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project.