On Fri 09-10-20 19:06:41, 常凤楠 wrote: > Hi Jan: > Thank you for your suggestions，I tested the new version of > the patch，I think there still have some prblems. 1. Looks > like you think jbd2_has_feature_checksum can determine that CRC is > enabled，but this is different from jbd2_journal_has_csum_v2or3. so when > csum is v2 or v3, this is still have problem. 2. This patch > looks fixed the situations of descriptor and revoke block, commit block > is not considered. Maybe it’s because my previous modification was > problematic，I have a new idea, how about check crc first and compare > timestap,if check crc is failed, then compare timestap, this way the risk > will be much smaller. What do you think? Hum, you're right that commit block checking will not work with v2/v3 checksums. Thanks for catching that! I like the order of checks you propose to fix the problem, I'll update the patch. Thanks! Honza > ------------------ Original ------------------ > From: "Theodore Y. Ts'o" <tytso@xxxxxxx>; > Date: Fri, Oct 9, 2020 10:16 AM > To: "Andreas Dilger"<adilger@xxxxxxxxx>; > Cc: "Jan Kara"<jack@xxxxxxx>;"linux-ext4"<linux-ext4@xxxxxxxxxxxxxxx>;"Fengnan Chang"<changfengnan@xxxxxxxxxxxxx>;"常凤楠"<fengnanchang@xxxxxxxxxxx>; > Subject: Re: [PATCH v4] jbd2: avoid transaction reuse after reformatting > > > > On Thu, Oct 08, 2020 at 02:13:02PM -0600, Andreas Dilger wrote: > > On Oct 7, 2020, at 2:13 AM, Jan Kara <jack@xxxxxxx> wrote: > > > > > > From: changfengnan <fengnanchang@xxxxxxxxxxx> > > > > > > When ext4 is formatted with lazy_journal_init=1 and transactions from > > > the previous filesystem are still on disk, it is possible that they are > > > considered during a recovery after a crash. Because the checksum seed > > > has changed, the CRC check will fail, and the journal recovery fails > > > with checksum error although the journal is otherwise perfectly valid. > > > Fix the problem by checking commit block time stamps to determine > > > whether the data in the journal block is just stale or whether it is > > > indeed corrupt. > > > > > > Reported-by: kernel test robot <lkp@xxxxxxxxx> > > > Signed-off-by: Fengnan Chang <changfengnan@xxxxxxxxxxxxx> > > > Signed-off-by: Jan Kara <jack@xxxxxxx> > > > > Reviewed-by: Andreas Dilger <adilger@xxxxxxxxx> > > > > NB: one trivial formatting cleanup if patch is refreshed > > > > Applied, thanks. I fixed the trivial format cleanup you pointed out, > plus a whitespace fix pointed out by checkpatch. > > - Ted -- Jan Kara <jack@xxxxxxxx> SUSE Labs, CR
