diff options
| author | Xiaoguang Wang <xiaoguang.wang@linux.alibaba.com> | 2019-01-31 23:42:11 -0500 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2019-01-31 23:42:11 -0500 |
| commit | 53cf978457325d8fb2cdecd7981b31a8229e446e (patch) | |
| tree | f090389c633b762bdcfe55aafa796fc46dc06cbb /fs/jbd2/journal.c | |
| parent | 8fdd60f2ae3682caf2a7258626abc21eb4711892 (diff) | |
jbd2: fix deadlock while checkpoint thread waits commit thread to finish
This issue was found when I tried to put checkpoint work in a separate thread,
the deadlock below happened:
Thread1 | Thread2
__jbd2_log_wait_for_space |
jbd2_log_do_checkpoint (hold j_checkpoint_mutex)|
if (jh->b_transaction != NULL) |
... |
jbd2_log_start_commit(journal, tid); |jbd2_update_log_tail
| will lock j_checkpoint_mutex,
| but will be blocked here.
|
jbd2_log_wait_commit(journal, tid); |
wait_event(journal->j_wait_done_commit, |
!tid_gt(tid, journal->j_commit_sequence)); |
... |wake_up(j_wait_done_commit)
} |
then deadlock occurs, Thread1 will never be waken up.
To fix this issue, drop j_checkpoint_mutex in jbd2_log_do_checkpoint()
when we are going to wait for transaction commit.
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Xiaoguang Wang <xiaoguang.wang@linux.alibaba.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'fs/jbd2/journal.c')
| -rw-r--r-- | fs/jbd2/journal.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c index 8ef6b6daaa7a..88d8f22d2cba 100644 --- a/fs/jbd2/journal.c +++ b/fs/jbd2/journal.c @@ -2067,7 +2067,7 @@ int jbd2_journal_wipe(journal_t *journal, int write) err = jbd2_journal_skip_recovery(journal); if (write) { /* Lock to make assertions happy... */ - mutex_lock(&journal->j_checkpoint_mutex); + mutex_lock_io(&journal->j_checkpoint_mutex); jbd2_mark_journal_empty(journal, REQ_SYNC | REQ_FUA); mutex_unlock(&journal->j_checkpoint_mutex); } |