These changes are a raw update to a vanilla kernel 4.1.10, with the

recently announced rt patch patch-4.1.10-rt10.patch. No further changes
needed.

Change-Id: I9a0cf084498133b10771e744b6da4b29dff706ba
Signed-off-by: José Pekkarinen <jose.pekkarinen@nokia.com>

3 files changed, 44 insertions, 8 deletions

diff --git a/kernel/fs/jbd2/checkpoint.c b/kernel/fs/jbd2/checkpoint.c
index 9c00e2e5a..78c1545a3 100644
--- a/kernel/fs/jbd2/checkpoint.c
+++ b/kernel/fs/jbd2/checkpoint.c
@@ -419,12 +419,12 @@ int jbd2_cleanup_journal_tail(journal_t *journal)
  * journal_clean_one_cp_list
  *
  * Find all the written-back checkpoint buffers in the given list and
- * release them.
+ * release them. If 'destroy' is set, clean all buffers unconditionally.
  *
  * Called with j_list_lock held.
  * Returns 1 if we freed the transaction, 0 otherwise.
  */
-static int journal_clean_one_cp_list(struct journal_head *jh)
+static int journal_clean_one_cp_list(struct journal_head *jh, bool destroy)
 {
 	struct journal_head *last_jh;
 	struct journal_head *next_jh = jh;
@@ -438,7 +438,10 @@ static int journal_clean_one_cp_list(struct journal_head *jh)
 	do {
 		jh = next_jh;
 		next_jh = jh->b_cpnext;
-		ret = __try_to_free_cp_buf(jh);
+		if (!destroy)
+			ret = __try_to_free_cp_buf(jh);
+		else
+			ret = __jbd2_journal_remove_checkpoint(jh) + 1;
 		if (!ret)
 			return freed;
 		if (ret == 2)
@@ -461,10 +464,11 @@ static int journal_clean_one_cp_list(struct journal_head *jh)
  * 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.
  *
  * Called with j_list_lock held.
  */
-void __jbd2_journal_clean_checkpoint_list(journal_t *journal)
+void __jbd2_journal_clean_checkpoint_list(journal_t *journal, bool destroy)
 {
 	transaction_t *transaction, *last_transaction, *next_transaction;
 	int ret;
@@ -478,7 +482,8 @@ void __jbd2_journal_clean_checkpoint_list(journal_t *journal)
 	do {
 		transaction = next_transaction;
 		next_transaction = transaction->t_cpnext;
-		ret = journal_clean_one_cp_list(transaction->t_checkpoint_list);
+		ret = journal_clean_one_cp_list(transaction->t_checkpoint_list,
+						destroy);
 		/*
 		 * This function only frees up some memory if possible so we
 		 * dont have an obligation to finish processing. Bail out if
@@ -494,7 +499,7 @@ void __jbd2_journal_clean_checkpoint_list(journal_t *journal)
 		 * we can possibly see not yet submitted buffers on io_list
 		 */
 		ret = journal_clean_one_cp_list(transaction->
-				t_checkpoint_io_list);
+				t_checkpoint_io_list, destroy);
 		if (need_resched())
 			return;
 		/*
@@ -508,6 +513,28 @@ void __jbd2_journal_clean_checkpoint_list(journal_t *journal)
 }
 
 /*
+ * Remove buffers from all checkpoint lists as journal is aborted and we just
+ * need to free memory
+ */
+void jbd2_journal_destroy_checkpoint(journal_t *journal)
+{
+	/*
+	 * We loop because __jbd2_journal_clean_checkpoint_list() may abort
+	 * early due to a need of rescheduling.
+	 */
+	while (1) {
+		spin_lock(&journal->j_list_lock);
+		if (!journal->j_checkpoint_transactions) {
+			spin_unlock(&journal->j_list_lock);
+			break;
+		}
+		__jbd2_journal_clean_checkpoint_list(journal, true);
+		spin_unlock(&journal->j_list_lock);
+		cond_resched();
+	}
+}
+
+/*
  * journal_remove_checkpoint: called after a buffer has been committed
  * to disk (either by being write-back flushed to disk, or being
  * committed to the log).
diff --git a/kernel/fs/jbd2/commit.c b/kernel/fs/jbd2/commit.c
index b73e0215b..362e5f614 100644
--- a/kernel/fs/jbd2/commit.c
+++ b/kernel/fs/jbd2/commit.c
@@ -510,7 +510,7 @@ void jbd2_journal_commit_transaction(journal_t *journal)
 	 * frees some memory
 	 */
 	spin_lock(&journal->j_list_lock);
-	__jbd2_journal_clean_checkpoint_list(journal);
+	__jbd2_journal_clean_checkpoint_list(journal, false);
 	spin_unlock(&journal->j_list_lock);
 
 	jbd_debug(3, "JBD2: commit phase 1\n");
diff --git a/kernel/fs/jbd2/journal.c b/kernel/fs/jbd2/journal.c
index 112fad9e1..7003c0925 100644
--- a/kernel/fs/jbd2/journal.c
+++ b/kernel/fs/jbd2/journal.c
@@ -1708,8 +1708,17 @@ int jbd2_journal_destroy(journal_t *journal)
 	while (journal->j_checkpoint_transactions != NULL) {
 		spin_unlock(&journal->j_list_lock);
 		mutex_lock(&journal->j_checkpoint_mutex);
-		jbd2_log_do_checkpoint(journal);
+		err = jbd2_log_do_checkpoint(journal);
 		mutex_unlock(&journal->j_checkpoint_mutex);
+		/*
+		 * If checkpointing failed, just free the buffers to avoid
+		 * looping forever
+		 */
+		if (err) {
+			jbd2_journal_destroy_checkpoint(journal);
+			spin_lock(&journal->j_list_lock);
+			break;
+		}
 		spin_lock(&journal->j_list_lock);
 	}