Thanks for the patch! Just some small comments below: On Sat 11-01-20 10:25:42, Kai Li wrote: > Fixes: 85e0c4e89c1b "jbd2: if the journal is aborted then don't allow update of the log tail" This tag should come at the bottom of the changelog (close to your Signed-off-by). > If journal is dirty when mount, it will be replayed but jbd2 sb > log tail cannot be updated to mark a new start because > journal->j_flags has already been set with JBD2_ABORT first > in journal_init_common. > When a new transaction is committed, it will be recorded in block 1 > first(journal->j_tail is set to 1 in journal_reset). If emergency > restart again before journal super block is updated unfortunately, > the new recorded trans will not be replayed in the next mount. > It is danerous which may lead to metadata corruption for file system. I'd slightly rephrase the text here so that it is more easily readable and correct some grammar mistakes. Something like: If the journal is dirty when the filesystem is mounted, jbd2 will replay the journal but the journal superblock will not be updated by journal_reset() because JBD2_ABORT flag is still set (it was set in journal_init_common()). This is problematic because when a new transaction is then committed, it will be recorded in block 1 (journal->j_tail was set to 1 in journal_reset()). If unclean shutdown happens again before the journal superblock is updated, the new recorded transaction will not be replayed during the next mount (because of stale sb->s_start and sb->s_sequence values) which can lead to filesystem corruption. Otherwise the patch looks good to me so feel free to add: Reviewed-by: Jan Kara <jack@xxxxxxx> (again this is added to the bottom of the changelog like the 'Fixes' tag or 'Signed-off-by' tag). Honza > > Signed-off-by: Kai Li <li.kai4@xxxxxxx> > --- > fs/jbd2/journal.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c > index 5e408ee24a1a..069b22eba795 100644 > --- a/fs/jbd2/journal.c > +++ b/fs/jbd2/journal.c > @@ -1710,6 +1710,11 @@ int jbd2_journal_load(journal_t *journal) > journal->j_devname); > return -EFSCORRUPTED; > } > + /* > + * clear JBD2_ABORT flag initialized in journal_init_common > + * here to update log tail information with the newest seq. > + */ > + journal->j_flags &= ~JBD2_ABORT; > > /* OK, we've finished with the dynamic journal bits: > * reinitialise the dynamic contents of the superblock in memory > @@ -1717,7 +1722,6 @@ int jbd2_journal_load(journal_t *journal) > if (journal_reset(journal)) > goto recovery_error; > > - journal->j_flags &= ~JBD2_ABORT; > journal->j_flags |= JBD2_LOADED; > return 0; > > -- > 2.24.0.windows.2 > -- Jan Kara <jack@xxxxxxxx> SUSE Labs, CR
