Linux-libre 4.2-gnu

1 files changed, 26 insertions, 0 deletions

diff --git a/drivers/md/dm-bio-prison.c b/drivers/md/dm-bio-prison.c
index be065300e..cd6d1d21e 100644
--- a/drivers/md/dm-bio-prison.c
+++ b/drivers/md/dm-bio-prison.c
@@ -255,6 +255,32 @@ void dm_cell_visit_release(struct dm_bio_prison *prison,
 }
 EXPORT_SYMBOL_GPL(dm_cell_visit_release);
 
+static int __promote_or_release(struct dm_bio_prison *prison,
+				struct dm_bio_prison_cell *cell)
+{
+	if (bio_list_empty(&cell->bios)) {
+		rb_erase(&cell->node, &prison->cells);
+		return 1;
+	}
+
+	cell->holder = bio_list_pop(&cell->bios);
+	return 0;
+}
+
+int dm_cell_promote_or_release(struct dm_bio_prison *prison,
+			       struct dm_bio_prison_cell *cell)
+{
+	int r;
+	unsigned long flags;
+
+	spin_lock_irqsave(&prison->lock, flags);
+	r = __promote_or_release(prison, cell);
+	spin_unlock_irqrestore(&prison->lock, flags);
+
+	return r;
+}
+EXPORT_SYMBOL_GPL(dm_cell_promote_or_release);
+
 /*----------------------------------------------------------------*/
 
 #define DEFERRED_SET_SIZE 64