From 6a89ecba39cbe74f07492ae0ef693d093450fda7 Mon Sep 17 00:00:00 2001
From: Christopher Haster <chaster@utexas.edu>
Date: Mon, 9 Apr 2018 14:36:52 -0500
Subject: [PATCH] Added test for lookahead overflow

---
 tests/test_alloc.sh | 32 ++++++++++++++++++++++++++++++--
 1 file changed, 30 insertions(+), 2 deletions(-)

diff --git a/tests/test_alloc.sh b/tests/test_alloc.sh
index 8c81490..484f1cc 100755
--- a/tests/test_alloc.sh
+++ b/tests/test_alloc.sh
@@ -110,10 +110,36 @@ lfs_alloc_singleproc multiprocreuse
 lfs_verify multiprocreuse
 lfs_verify singleprocreuse
 
-echo "--- Cleanup ---"
 lfs_remove multiprocreuse
 lfs_remove singleprocreuse
 
+echo "--- Lookahead overflow test ---"
+lfs_mkdir overflow
+for name in bacon eggs pancakes
+do
+tests/test.py << TEST
+    lfs_mount(&lfs, &cfg) => 0;
+
+    // setup lookahead to almost overflow
+    lfs.free.begin = ((lfs_size_t)-1) - $SIZE/(2*cfg.block_size);
+    lfs.free.size = 0;
+    lfs.free.off = 0;
+
+    lfs_file_open(&lfs, &file[0], "overflow/$name",
+            LFS_O_WRONLY | LFS_O_CREAT | LFS_O_APPEND) => 0;
+    size = strlen("$name");
+    memcpy(buffer, "$name", size);
+    for (int i = 0; i < $SIZE; i++) {
+        printf("%d\n", lfs.free.begin);
+        lfs_file_write(&lfs, &file[0], buffer, size) => size;
+    }
+    lfs_file_close(&lfs, &file[0]) => 0;
+    lfs_unmount(&lfs) => 0;
+TEST
+done
+lfs_verify overflow
+lfs_remove overflow
+
 echo "--- Exhaustion test ---"
 tests/test.py << TEST
     lfs_mount(&lfs, &cfg) => 0;
@@ -368,7 +394,6 @@ echo "--- Outdated lookahead and split dir test ---"
 rm -rf blocks
 tests/test.py << TEST
     lfs_format(&lfs, &cfg) => 0;
-
     lfs_mount(&lfs, &cfg) => 0;
 
     // fill completely with two files
@@ -424,5 +449,8 @@ tests/test.py << TEST
     lfs_unmount(&lfs) => 0;
 TEST
 
+
+
+
 echo "--- Results ---"
 tests/stats.py