jbd2: use shrink_type type instead of bool type for __jbd2_journal_clean_checkpoint_list()

"enum shrink_type" can clearly express the meaning of the parameter of
__jbd2_journal_clean_checkpoint_list(), and there is no need to use the
bool type.

Signed-off-by: Ye Bin <[email protected]>
Reviewed-by: Jan Kara <[email protected]>
Reviewed-by: Zhang Yi <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Theodore Ts'o <[email protected]>

Author: Ye Bin

fs/jbd2/checkpoint.c

@@ -337,8 +337,6 @@ int jbd2_cleanup_journal_tail(journal_t *journal)
 
 /* Checkpoint list management */
 
-enum shrink_type {SHRINK_DESTROY, SHRINK_BUSY_STOP, SHRINK_BUSY_SKIP};
-
 /*
  * journal_shrink_one_cp_list
  *
@@ -472,21 +470,25 @@ unsigned long jbd2_journal_shrink_checkpoint_list(journal_t *journal,
  * journal_clean_checkpoint_list
  *
  * Find all the written-back checkpoint buffers in the journal and release them.
- * If 'destroy' is set, release all buffers unconditionally.
+ * If 'type' is SHRINK_DESTROY, release all buffers unconditionally. If 'type'
+ * is SHRINK_BUSY_STOP, will stop release buffers if encounters a busy buffer.
+ * To avoid wasting CPU cycles scanning the buffer list in some cases, don't
+ * pass SHRINK_BUSY_SKIP 'type' for this function.
  *
  * Called with j_list_lock held.
  */
-void __jbd2_journal_clean_checkpoint_list(journal_t *journal, bool destroy)
+void __jbd2_journal_clean_checkpoint_list(journal_t *journal,
+					  enum shrink_type type)
 {
 	transaction_t *transaction, *last_transaction, *next_transaction;
-	enum shrink_type type;
 	bool released;
 
+	WARN_ON_ONCE(type == SHRINK_BUSY_SKIP);
+
 	transaction = journal->j_checkpoint_transactions;
 	if (!transaction)
 		return;
 
-	type = destroy ? SHRINK_DESTROY : SHRINK_BUSY_STOP;
 	last_transaction = transaction->t_cpprev;
 	next_transaction = transaction;
 	do {
@@ -527,7 +529,7 @@ void jbd2_journal_destroy_checkpoint(journal_t *journal)
 			spin_unlock(&journal->j_list_lock);
 			break;
 		}
-		__jbd2_journal_clean_checkpoint_list(journal, true);
+		__jbd2_journal_clean_checkpoint_list(journal, SHRINK_DESTROY);
 		spin_unlock(&journal->j_list_lock);
 		cond_resched();
 	}

fs/jbd2/commit.c

@@ -501,7 +501,7 @@ void jbd2_journal_commit_transaction(journal_t *journal)
 	 * frees some memory
 	 */
 	spin_lock(&journal->j_list_lock);
-	__jbd2_journal_clean_checkpoint_list(journal, false);
+	__jbd2_journal_clean_checkpoint_list(journal, SHRINK_BUSY_STOP);
 	spin_unlock(&journal->j_list_lock);
 
 	jbd2_debug(3, "JBD2: commit phase 1\n");

include/linux/jbd2.h

@@ -1434,7 +1434,9 @@ void jbd2_update_log_tail(journal_t *journal, tid_t tid, unsigned long block);
 extern void jbd2_journal_commit_transaction(journal_t *);
 
 /* Checkpoint list management */
-void __jbd2_journal_clean_checkpoint_list(journal_t *journal, bool destroy);
+enum shrink_type {SHRINK_DESTROY, SHRINK_BUSY_STOP, SHRINK_BUSY_SKIP};
+
+void __jbd2_journal_clean_checkpoint_list(journal_t *journal, enum shrink_type type);
 unsigned long jbd2_journal_shrink_checkpoint_list(journal_t *journal, unsigned long *nr_to_scan);
 int __jbd2_journal_remove_checkpoint(struct journal_head *);
 int jbd2_journal_try_remove_checkpoint(struct journal_head *jh);