Index: uspace/lib/block/libblock.c
===================================================================
--- uspace/lib/block/libblock.c	(revision 0c968a174f806fa1ecd217fa560e17d52b328b6a)
+++ uspace/lib/block/libblock.c	(revision b927375984efc8c979a7d300d84c79a370dbd54d)
@@ -626,4 +626,5 @@
 			unsigned long key = block->lba;
 			hash_table_remove(&cache->block_hash, &key, 1);
+			fibril_mutex_unlock(&block->lock);
 			free(block->data);
 			free(block);