diff --git a/tests/generic/075 b/tests/generic/075
index 2b957891..923c9e4f 100755
--- a/tests/generic/075
+++ b/tests/generic/075
@@ -48,11 +48,9 @@ _do_test()
     echo "fsx.$_n : $_filter_param"
     echo "-----------------------------------------------"
 
-    if [ "$FSTYP" != "xfs" ]
-    then
-	if [ "$_n" = "1" -o "$_n" = "3" ]
-	then
-	    # HACK: only xfs handles preallocation (-x) so just skip this test
+    # Skip the prealloc runs if the file system does not support preallocation
+    if [ "$_n" = "1" -o "$_n" = "3" ]; then
+        if [ -n "$testio" ]; then
 	    return
 	fi
     fi
@@ -128,6 +126,12 @@ echo "brevity is wit..."
 
 _check_test_fs
 
+# check if preallocation is supported, xfs_io resvsp command only prints out
+# messages on failure.
+testfile=$TEST_DIR/$$.xfs_io
+testio=`$XFS_IO_PROG -f -c "resvsp 0 1" $testfile 2>&1`
+rm -f $testfile 2>&1 > /dev/null
+
 # Options:
 # -d: debug output for all operations
 # -l flen: the upper bound on file size (default 262144)
diff --git a/tests/generic/112 b/tests/generic/112
index 1879e7b5..18d610ee 100755
--- a/tests/generic/112
+++ b/tests/generic/112
@@ -48,13 +48,11 @@ _do_test()
     echo "fsx.$_n : $_filter_param"
     echo "-----------------------------------------------"
 
-    if [ "$FSTYP" != "xfs" ]
-    then
-        if [ "$_n" = "1" -o "$_n" = "3" ]
-        then
-            # HACK: only xfs handles preallocation (-x) so just skip this test
-            return
-        fi
+    # Skip the prealloc runs if the file system does not support preallocation
+    if [ "$_n" = "1" -o "$_n" = "3" ]; then
+        if [ -n "$testio" ]; then
+	    return
+	fi
     fi
 
     # This cd and use of -P gets full debug on $here (not TEST_DEV)
@@ -128,6 +126,12 @@ echo "brevity is wit..."
 
 _check_test_fs
 
+# check if preallocation is supported, xfs_io resvsp command only prints out
+# messages on failure.
+testfile=$TEST_DIR/$$.xfs_io
+testio=`$XFS_IO_PROG -f -c "resvsp 0 1" $testfile 2>&1`
+rm -f $testfile 2>&1 > /dev/null
+
 # Options:
 # -d: debug output for all operations
 # -l flen: the upper bound on file size (default 262144)