From 5c2178e785244341d1e6f2bc3b62f20a337cc44f Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Wed, 27 Oct 2010 21:30:04 -0400 Subject: [PATCH] jbd2: Add sanity check for attempts to start handle during umount An attempt to modify the file system during the call to jbd2_destroy_journal() can lead to a system lockup. So add some checking to make it much more obvious when this happens to and to determine where the offending code is located. Signed-off-by: "Theodore Ts'o" --- fs/jbd2/checkpoint.c | 10 ++++++++++ fs/jbd2/transaction.c | 1 + 2 files changed, 11 insertions(+) diff --git a/fs/jbd2/checkpoint.c b/fs/jbd2/checkpoint.c index 5247e7ffdcb4..524800dce207 100644 --- a/fs/jbd2/checkpoint.c +++ b/fs/jbd2/checkpoint.c @@ -299,6 +299,16 @@ static int __process_buffer(journal_t *journal, struct journal_head *jh, transaction->t_chp_stats.cs_forced_to_close++; spin_unlock(&journal->j_list_lock); jbd_unlock_bh_state(bh); + if (unlikely(journal->j_flags & JBD2_UNMOUNT)) + /* + * The journal thread is dead; so starting and + * waiting for a commit to finish will cause + * us to wait for a _very_ long time. + */ + printk(KERN_ERR "JBD2: %s: " + "Waiting for Godot: block %llu\n", + journal->j_devname, + (unsigned long long) bh->b_blocknr); jbd2_log_start_commit(journal, tid); jbd2_log_wait_commit(journal, tid); ret = 1; diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c index f3479d6e0a83..6bf0a242613e 100644 --- a/fs/jbd2/transaction.c +++ b/fs/jbd2/transaction.c @@ -156,6 +156,7 @@ static int start_this_handle(journal_t *journal, handle_t *handle, */ repeat: read_lock(&journal->j_state_lock); + BUG_ON(journal->j_flags & JBD2_UNMOUNT); if (is_journal_aborted(journal) || (journal->j_errno != 0 && !(journal->j_flags & JBD2_ACK_ERR))) { read_unlock(&journal->j_state_lock); -- GitLab