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| author | Theodore Ts'o <tytso@mit.edu> | 2011-02-12 14:18:24 +0100 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2011-02-12 14:18:24 +0100 |
| commit | e44718318004a5618d1dfe2d080e2862532d8e5f (patch) | |
| tree | c1a6af07da3184f5785a62062510ac8e86b8050a /fs/jbd2/journal.c | |
| parent | ext4: serialize unaligned asynchronous DIO (diff) | |
| download | linux-e44718318004a5618d1dfe2d080e2862532d8e5f.tar.xz linux-e44718318004a5618d1dfe2d080e2862532d8e5f.zip | |
jbd2: call __jbd2_log_start_commit with j_state_lock write locked
On an SMP ARM system running ext4, I've received a report that the
first J_ASSERT in jbd2_journal_commit_transaction has been triggering:
J_ASSERT(journal->j_running_transaction != NULL);
While investigating possible causes for this problem, I noticed that
__jbd2_log_start_commit() is getting called with j_state_lock only
read-locked, in spite of the fact that it's possible for it might
j_commit_request. Fix this by grabbing the necessary information so
we can test to see if we need to start a new transaction before
dropping the read lock, and then calling jbd2_log_start_commit() which
will grab the write lock.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Diffstat (limited to 'fs/jbd2/journal.c')
| -rw-r--r-- | fs/jbd2/journal.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c index 9e4686900f18..97e73469b2c4 100644 --- a/fs/jbd2/journal.c +++ b/fs/jbd2/journal.c @@ -473,7 +473,8 @@ int __jbd2_log_space_left(journal_t *journal) } /* - * Called under j_state_lock. Returns true if a transaction commit was started. + * Called with j_state_lock locked for writing. + * Returns true if a transaction commit was started. */ int __jbd2_log_start_commit(journal_t *journal, tid_t target) { @@ -520,11 +521,13 @@ int jbd2_journal_force_commit_nested(journal_t *journal) { transaction_t *transaction = NULL; tid_t tid; + int need_to_start = 0; read_lock(&journal->j_state_lock); if (journal->j_running_transaction && !current->journal_info) { transaction = journal->j_running_transaction; - __jbd2_log_start_commit(journal, transaction->t_tid); + if (!tid_geq(journal->j_commit_request, transaction->t_tid)) + need_to_start = 1; } else if (journal->j_committing_transaction) transaction = journal->j_committing_transaction; @@ -535,6 +538,8 @@ int jbd2_journal_force_commit_nested(journal_t *journal) tid = transaction->t_tid; read_unlock(&journal->j_state_lock); + if (need_to_start) + jbd2_log_start_commit(journal, tid); jbd2_log_wait_commit(journal, tid); return 1; } |