>-----Original Message----- >From: Jaegeuk Kim [mailto:[email protected]] >Sent: Thursday, December 21, 2017 5:01 AM >To: heyunlei >Cc: Yuchao (T); [email protected]; Wangbintian; Jianing >(Euler) >Subject: Re: [f2fs-dev][PATCH v5] f2fs: avoid dead loop in function >find_fsync_dnodes > >Hi Yunlei, Hi Kim， > >On 12/20, Yunlei He wrote: >> 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 <[email protected]> >> --- >> 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; > >Is there any problem, if we break here without error, so that we could recover >some of the inodes in the chain as best efforts?
I think it's a corner case caused by some weird reason. Maybe data in recover node Chain is also polluted and unreliable. So I think we'd better abandon this recovery. Thanks， > >Thanks, > >> + 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 _______________________________________________ Linux-f2fs-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
