Index: uspace/lib/libblock/libblock.c
===================================================================
--- uspace/lib/libblock/libblock.c	(revision 696979ce4e193ad741334bf5d1c4465213c5ace9)
+++ uspace/lib/libblock/libblock.c	(revision 24a25179b05f83c8e256aa72e57afcd2c60ee336)
@@ -52,4 +52,6 @@
 #include <macros.h>
 #include <mem.h>
+#include <sys/typefmt.h>
+#include <stacktrace.h>
 
 /** Lock protecting the device connection list */
@@ -813,4 +815,12 @@
 	rc = async_req_3_0(devcon->dev_phone, BD_READ_BLOCKS, LOWER32(ba),
 	    UPPER32(ba), cnt);
+	if (rc != EOK) {
+		printf("Error %d reading %d blocks starting at block %" PRIuBN
+		    " from device handle %d\n", rc, cnt, ba,
+		    devcon->dev_handle);
+#ifndef NDEBUG
+		stacktrace_print();
+#endif
+	}
 	return rc;
 }
@@ -832,4 +842,11 @@
 	rc = async_req_3_0(devcon->dev_phone, BD_WRITE_BLOCKS, LOWER32(ba),
 	    UPPER32(ba), cnt);
+	if (rc != EOK) {
+		printf("Error %d writing %d blocks starting at block %" PRIuBN
+		    " to device handle %d\n", rc, cnt, ba, devcon->dev_handle);
+#ifndef NDEBUG
+		stacktrace_print();
+#endif
+	}
 	return rc;
 }