From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yunlei He Subject: [PATCH v4] f2fs: avoid dead loop in function find_fsync_dnodes Date: Fri, 15 Dec 2017 15:56:56 +0800 Message-ID: <1513324616-21058-1-git-send-email-heyunlei@huawei.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from sfi-mx-3.v28.ch3.sourceforge.com ([172.29.28.193] helo=mx.sourceforge.net) by sfs-ml-1.v29.ch3.sourceforge.com with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.89) (envelope-from ) id 1ePl4d-000345-De for linux-f2fs-devel@lists.sourceforge.net; Fri, 15 Dec 2017 08:10:27 +0000 Received: from szxga05-in.huawei.com ([45.249.212.191]) by sfi-mx-3.v28.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128) (Exim 4.89) id 1ePl4b-00083g-5m for linux-f2fs-devel@lists.sourceforge.net; Fri, 15 Dec 2017 08:10:27 +0000 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-f2fs-devel-bounces@lists.sourceforge.net To: jaegeuk@kernel.org, yuchao0@huawei.com, linux-f2fs-devel@lists.sourceforge.net Cc: ning.jia@huawei.com, heyunlei@huawei.com Came across a dead loop in recovery like this: ...... [ 24.680480s][pid:320,cpu0,init]find_fsync_dnodes: blkaddr =13597696 [ 24.698394s][pid:320,cpu0,init]find_fsync_dnodes: blkaddr =13597697 [ 24.724334s][pid:320,cpu0,init]find_fsync_dnodes: blkaddr =13597698 [ 24.724334s][pid:320,cpu0,init]find_fsync_dnodes: blkaddr =13597698 [ 24.724365s][pid:320,cpu0,init]find_fsync_dnodes: blkaddr =13597698 [ 24.724365s][pid:320,cpu0,init]find_fsync_dnodes: blkaddr =13597698 [ 24.724365s][pid:320,cpu0,init]find_fsync_dnodes: blkaddr =13597698 [ 24.724395s][pid:320,cpu0,init]find_fsync_dnodes: blkaddr =13597698 [ 24.724395s][pid:320,cpu0,init]find_fsync_dnodes: blkaddr =13597698 [ 24.724395s][pid:320,cpu0,init]find_fsync_dnodes: blkaddr =13597698 [ 24.724395s][pid:320,cpu0,init]find_fsync_dnodes: blkaddr =13597698 [ 24.724426s][pid:320,cpu0,init]find_fsync_dnodes: blkaddr =13597698 ...... Mount process will block in dead loop and fsck can do nothing with this error, This patch abandon recovery if node chain is cyclical. Signed-off-by: Yunlei He --- fs/f2fs/recovery.c | 27 +++++++++++++++++++-------- 1 file changed, 19 insertions(+), 8 deletions(-) diff --git a/fs/f2fs/recovery.c b/fs/f2fs/recovery.c index 7d63faf..f7fc2ed 100644 --- a/fs/f2fs/recovery.c +++ b/fs/f2fs/recovery.c @@ -106,6 +106,14 @@ static void del_fsync_inode(struct fsync_inode_entry *entry) kmem_cache_free(fsync_entry_slab, entry); } +static void destroy_fsync_dnodes(struct list_head *head) +{ + struct fsync_inode_entry *entry, *tmp; + + list_for_each_entry_safe(entry, tmp, head, list) + del_fsync_inode(entry); +} + static int recover_dentry(struct inode *inode, struct page *ipage, struct list_head *dir_list) { @@ -239,6 +247,17 @@ static int find_fsync_dnodes(struct f2fs_sb_info *sbi, struct list_head *head, return 0; page = get_tmp_page(sbi, blkaddr); + if (PageChecked(page)) { + f2fs_msg(sbi->sb, KERN_ERR, "Abandon looped node block list"); + destroy_fsync_dnodes(head); + break; + } + + /* + * it's not needed to clear PG_checked flag in temp page since we + * will truncate all those pages in the end of recovery. + */ + SetPageChecked(page); if (!is_recoverable_dnode(page)) break; @@ -288,14 +307,6 @@ static int find_fsync_dnodes(struct f2fs_sb_info *sbi, struct list_head *head, return err; } -static void destroy_fsync_dnodes(struct list_head *head) -{ - struct fsync_inode_entry *entry, *tmp; - - list_for_each_entry_safe(entry, tmp, head, list) - del_fsync_inode(entry); -} - static int check_index_in_prev_nodes(struct f2fs_sb_info *sbi, block_t blkaddr, struct dnode_of_data *dn) { -- 1.9.1 ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot