Index: uspace/srv/fs/fat/fat_ops.c
===================================================================
--- uspace/srv/fs/fat/fat_ops.c	(revision 61bc9018c9b20a698eed11fadc520cb973a9099b)
+++ uspace/srv/fs/fat/fat_ops.c	(revision a61d1fc3aa43e7a55cd4864d7eb1669c9e1f12f4)
@@ -50,4 +50,5 @@
 
 #define BS_BLOCK		0
+#define BS_SIZE			512
 
 /** Futex protecting the list of cached free FAT nodes. */
@@ -100,5 +101,5 @@
 } block_t;
 
-static block_t *block_get(dev_handle_t dev_handle, off_t offset)
+static block_t *block_get(dev_handle_t dev_handle, off_t offset, size_t bs)
 {
 	return NULL;	/* TODO */
@@ -144,5 +145,5 @@
 	unsigned i;
 
-	bb = block_get(dev_handle, BS_BLOCK);
+	bb = block_get(dev_handle, BS_BLOCK, BS_SIZE);
 	bps = uint16_t_le2host(FAT_BS(bb)->bps);
 	spc = FAT_BS(bb)->spc;
@@ -160,5 +161,5 @@
 		/* root directory special case */
 		assert(offset < rds);
-		b = block_get(dev_handle, rscnt + fatcnt * sf + offset);
+		b = block_get(dev_handle, rscnt + fatcnt * sf + offset, bps);
 		return b;
 	}
@@ -173,5 +174,5 @@
 		fidx = clst % (bps / sizeof(fat_cluster_t));
 		/* read FAT1 */
-		b = block_get(dev_handle, rscnt + fsec);
+		b = block_get(dev_handle, rscnt + fsec, bps);
 		clst = uint16_t_le2host(((fat_cluster_t *)b->data)[fidx]);
 		assert(clst != FAT_CLST_BAD);
@@ -181,5 +182,5 @@
 
 	b = block_get(dev_handle, ssa + (clst - FAT_CLST_FIRST) * spc +
-	    offset % spc);
+	    offset % spc, bps);
 
 	return b;
@@ -203,5 +204,5 @@
 	uint16_t bps;
 	
-	bb = block_get(dev_handle, BS_BLOCK);
+	bb = block_get(dev_handle, BS_BLOCK, BS_SIZE);
 	assert(bb != NULL);
 	bps = uint16_t_le2host(FAT_BS(bb)->bps);
@@ -572,5 +573,5 @@
 
 	/* Read the number of root directory entries. */
-	bb = block_get(dev_handle, BS_BLOCK);
+	bb = block_get(dev_handle, BS_BLOCK, BS_SIZE);
 	rde = uint16_t_le2host(FAT_BS(bb)->root_ent_max);
 	block_put(bb);