jbd2: clear JBD2_ABORT flag before journal_reset to update log tail info when load...

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.

Fixes: 85e0c4e89c1b ("jbd2: if the journal is aborted then don't allow update of the log tail")
Signed-off-by: Kai Li <li.kai4@h3c.com>
Link: https://lore.kernel.org/r/20200111022542.5008-1-li.kai4@h3c.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 5e408ee24a1a8c78179b6371c64299064b2b9375..069b22eba7955f6ca7b1e6c6cfdf8eb265be6967 100644 (file)
--- 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;