jbd2: optimize jbd2_journal_force_commit
Current implementation of jbd2_journal_force_commit() is suboptimal because
result in empty and useless commits. But callers just want to force and wait
any unfinished commits. We already have jbd2_journal_force_commit_nested()
which does exactly what we want, except we are guaranteed that we do not hold
journal transaction open.
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 70990d6..0e6c13b 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -529,20 +529,17 @@
}
/*
- * Force and wait upon a commit if the calling process is not within
- * transaction. This is used for forcing out undo-protected data which contains
- * bitmaps, when the fs is running out of space.
- *
- * We can only force the running transaction if we don't have an active handle;
- * otherwise, we will deadlock.
- *
- * Returns true if a transaction was started.
+ * Force and wait any uncommitted transactions. We can only force the running
+ * transaction if we don't have an active handle, otherwise, we will deadlock.
+ * Returns: <0 in case of error,
+ * 0 if nothing to commit,
+ * 1 if transaction was successfully committed.
*/
-int jbd2_journal_force_commit_nested(journal_t *journal)
+static int __jbd2_journal_force_commit(journal_t *journal)
{
transaction_t *transaction = NULL;
tid_t tid;
- int need_to_start = 0;
+ int need_to_start = 0, ret = 0;
read_lock(&journal->j_state_lock);
if (journal->j_running_transaction && !current->journal_info) {
@@ -553,16 +550,53 @@
transaction = journal->j_committing_transaction;
if (!transaction) {
+ /* Nothing to commit */
read_unlock(&journal->j_state_lock);
- return 0; /* Nothing to retry */
+ return 0;
}
-
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;
+ ret = jbd2_log_wait_commit(journal, tid);
+ if (!ret)
+ ret = 1;
+
+ return ret;
+}
+
+/**
+ * Force and wait upon a commit if the calling process is not within
+ * transaction. This is used for forcing out undo-protected data which contains
+ * bitmaps, when the fs is running out of space.
+ *
+ * @journal: journal to force
+ * Returns true if progress was made.
+ */
+int jbd2_journal_force_commit_nested(journal_t *journal)
+{
+ int ret;
+
+ ret = __jbd2_journal_force_commit(journal);
+ return ret > 0;
+}
+
+/**
+ * int journal_force_commit() - force any uncommitted transactions
+ * @journal: journal to force
+ *
+ * Caller want unconditional commit. We can only force the running transaction
+ * if we don't have an active handle, otherwise, we will deadlock.
+ */
+int jbd2_journal_force_commit(journal_t *journal)
+{
+ int ret;
+
+ J_ASSERT(!current->journal_info);
+ ret = __jbd2_journal_force_commit(journal);
+ if (ret > 0)
+ ret = 0;
+ return ret;
}
/*