linux-f2fs-devel.lists.sourceforge.net archive mirror
 help / color / mirror / Atom feed
From: Yunlei He <heyunlei@huawei.com>
To: jaegeuk@kernel.org, yuchao0@huawei.com,
	linux-f2fs-devel@lists.sourceforge.net
Cc: ning.jia@huawei.com, heyunlei@huawei.com
Subject: [PATCH v5] f2fs: avoid dead loop in function find_fsync_dnodes
Date: Wed, 20 Dec 2017 13:03:32 +0800	[thread overview]
Message-ID: <1513746212-19454-1-git-send-email-heyunlei@huawei.com> (raw)

v4 -> v5 return err instead destory inode list for two reasons:
i.  avoid duplicated destroy inode list in function recover_fsync_data.
ii. report an error for recovery, and set need_fsck flag
        
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 <heyunlei@huawei.com>
---
 fs/f2fs/recovery.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/fs/f2fs/recovery.c b/fs/f2fs/recovery.c
index d025aa8..a535ec2 100644
--- a/fs/f2fs/recovery.c
+++ b/fs/f2fs/recovery.c
@@ -216,6 +216,17 @@ 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");
+			err = -EINVAL;
+			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;
-- 
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

             reply	other threads:[~2017-12-20  5:17 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-12-20  5:03 Yunlei He [this message]
2017-12-20 21:00 ` [PATCH v5] f2fs: avoid dead loop in function find_fsync_dnodes Jaegeuk Kim
2017-12-21  3:45   ` heyunlei
2017-12-25  2:33 ` Chao Yu
2017-12-28  2:37   ` Jaegeuk Kim
2018-01-04  3:07     ` Chao Yu

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1513746212-19454-1-git-send-email-heyunlei@huawei.com \
    --to=heyunlei@huawei.com \
    --cc=jaegeuk@kernel.org \
    --cc=linux-f2fs-devel@lists.sourceforge.net \
    --cc=ning.jia@huawei.com \
    --cc=yuchao0@huawei.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).