+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);
+