1 files changed, 28 insertions, 17 deletions

diff --git a/fs/jbd2/checkpoint.c b/fs/jbd2/checkpoint.c
index 1c97e64c4784..b3971e91e8eb 100644
--- a/fs/jbd2/checkpoint.c
+++ b/fs/jbd2/checkpoint.c
@@ -79,17 +79,23 @@ __releases(&journal->j_state_lock)
 		if (space_left < nblocks) {
 			int chkpt = journal->j_checkpoint_transactions != NULL;
 			tid_t tid = 0;
+			bool has_transaction = false;
 
-			if (journal->j_committing_transaction)
+			if (journal->j_committing_transaction) {
 				tid = journal->j_committing_transaction->t_tid;
+				has_transaction = true;
+			}
 			spin_unlock(&journal->j_list_lock);
 			write_unlock(&journal->j_state_lock);
 			if (chkpt) {
 				jbd2_log_do_checkpoint(journal);
-			} else if (jbd2_cleanup_journal_tail(journal) == 0) {
-				/* We were able to recover space; yay! */
+			} else if (jbd2_cleanup_journal_tail(journal) <= 0) {
+				/*
+				 * We were able to recover space or the
+				 * journal was aborted due to an error.
+				 */
 				;
-			} else if (tid) {
+			} else if (has_transaction) {
 				/*
 				 * jbd2_journal_commit_transaction() may want
 				 * to take the checkpoint_mutex if JBD2_FLUSHED
@@ -337,8 +343,6 @@ 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
  *
@@ -350,7 +354,7 @@ enum shrink_type {SHRINK_DESTROY, SHRINK_BUSY_STOP, SHRINK_BUSY_SKIP};
  * Called with j_list_lock held.
  */
 static unsigned long journal_shrink_one_cp_list(struct journal_head *jh,
-						enum shrink_type type,
+						enum jbd2_shrink_type type,
 						bool *released)
 {
 	struct journal_head *last_jh;
@@ -367,12 +371,12 @@ static unsigned long journal_shrink_one_cp_list(struct journal_head *jh,
 		jh = next_jh;
 		next_jh = jh->b_cpnext;
 
-		if (type == SHRINK_DESTROY) {
+		if (type == JBD2_SHRINK_DESTROY) {
 			ret = __jbd2_journal_remove_checkpoint(jh);
 		} else {
 			ret = jbd2_journal_try_remove_checkpoint(jh);
 			if (ret < 0) {
-				if (type == SHRINK_BUSY_SKIP)
+				if (type == JBD2_SHRINK_BUSY_SKIP)
 					continue;
 				break;
 			}
@@ -409,6 +413,7 @@ unsigned long jbd2_journal_shrink_checkpoint_list(journal_t *journal,
 	tid_t tid = 0;
 	unsigned long nr_freed = 0;
 	unsigned long freed;
+	bool first_set = false;
 
 again:
 	spin_lock(&journal->j_list_lock);
@@ -428,8 +433,10 @@ again:
 	else
 		transaction = journal->j_checkpoint_transactions;
 
-	if (!first_tid)
+	if (!first_set) {
 		first_tid = transaction->t_tid;
+		first_set = true;
+	}
 	last_transaction = journal->j_checkpoint_transactions->t_cpprev;
 	next_transaction = transaction;
 	last_tid = last_transaction->t_tid;
@@ -439,7 +446,7 @@ again:
 		tid = transaction->t_tid;
 
 		freed = journal_shrink_one_cp_list(transaction->t_checkpoint_list,
-						   SHRINK_BUSY_SKIP, &released);
+						   JBD2_SHRINK_BUSY_SKIP, &released);
 		nr_freed += freed;
 		(*nr_to_scan) -= min(*nr_to_scan, freed);
 		if (*nr_to_scan == 0)
@@ -459,7 +466,7 @@ again:
 	spin_unlock(&journal->j_list_lock);
 	cond_resched();
 
-	if (*nr_to_scan && next_tid)
+	if (*nr_to_scan && journal->j_shrink_transaction)
 		goto again;
 out:
 	trace_jbd2_shrink_checkpoint_list(journal, first_tid, tid, last_tid,
@@ -472,21 +479,25 @@ out:
  * 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 JBD2_SHRINK_DESTROY, release all buffers unconditionally. If
+ * 'type' is JBD2_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 JBD2_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 jbd2_shrink_type type)
 {
 	transaction_t *transaction, *last_transaction, *next_transaction;
-	enum shrink_type type;
 	bool released;
 
+	WARN_ON_ONCE(type == JBD2_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 +538,7 @@ 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, JBD2_SHRINK_DESTROY);
 		spin_unlock(&journal->j_list_lock);
 		cond_resched();
 	}