From 4327ba52afd03fc4b5afa0ee1d774c9c5b0e85c5 Mon Sep 17 00:00:00 2001 From: Daeho Jeong Date: Sun, 18 Oct 2015 17:02:56 -0400 Subject: ext4, jbd2: ensure entering into panic after recording an error in superblock If a EXT4 filesystem utilizes JBD2 journaling and an error occurs, the journaling will be aborted first and the error number will be recorded into JBD2 superblock and, finally, the system will enter into the panic state in "errors=panic" option. But, in the rare case, this sequence is little twisted like the below figure and it will happen that the system enters into panic state, which means the system reset in mobile environment, before completion of recording an error in the journal superblock. In this case, e2fsck cannot recognize that the filesystem failure occurred in the previous run and the corruption wouldn't be fixed. Task A Task B ext4_handle_error() -> jbd2_journal_abort() -> __journal_abort_soft() -> __jbd2_journal_abort_hard() | -> journal->j_flags |= JBD2_ABORT; | | __ext4_abort() | -> jbd2_journal_abort() | | -> __journal_abort_soft() | | -> if (journal->j_flags & JBD2_ABORT) | | return; | -> panic() | -> jbd2_journal_update_sb_errno() Tested-by: Hobin Woo Signed-off-by: Daeho Jeong Signed-off-by: Theodore Ts'o Cc: stable@vger.kernel.org --- fs/jbd2/journal.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'fs/jbd2') diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c index eb8a7546e8a4..81e622681c82 100644 --- a/fs/jbd2/journal.c +++ b/fs/jbd2/journal.c @@ -2072,8 +2072,12 @@ static void __journal_abort_soft (journal_t *journal, int errno) __jbd2_journal_abort_hard(journal); - if (errno) + if (errno) { jbd2_journal_update_sb_errno(journal); + write_lock(&journal->j_state_lock); + journal->j_flags |= JBD2_REC_ERR; + write_unlock(&journal->j_state_lock); + } } /** -- cgit v1.2.3