From bbfb9ca8003fd3fe9166947e1dcebc63850a8703 Mon Sep 17 00:00:00 2001
From: "S.J.R. van Schaik" <stephan@whiteboxsystems.nl>
Date: Wed, 20 Sep 2017 14:30:08 +0200
Subject: [PATCH] ftl: mock is_group_erased() and find_block() and simplify
 implementation of binary search

---
 source/ftl/map.c | 48 ++++++++++++++++++++++++++++++++++--------------
 1 file changed, 34 insertions(+), 14 deletions(-)

diff --git a/source/ftl/map.c b/source/ftl/map.c
index 1e39528..609c23e 100644
--- a/source/ftl/map.c
+++ b/source/ftl/map.c
@@ -12,7 +12,12 @@
 /* Given the group number, this function checks if a page group is erased by
  * checking if the pages that compose the page group are erased.
  */
-static int is_group_erased(struct ftl_map *map, uint32_t group)
+#ifdef is_group_erased
+#undef is_group_erased
+#define is_group_erased __real_is_group_erased
+#endif
+
+int is_group_erased(struct ftl_map *map, uint32_t group)
 {
 	uint8_t data[32];
 	struct flash_dev *dev = map->dev;
@@ -37,6 +42,13 @@ static int is_group_erased(struct ftl_map *map, uint32_t group)
 	return 1;
 }
 
+#ifdef is_group_erased
+#undef is_group_erased
+#define is_group_erased __wrap_is_group_erased
+#endif
+
+int __wrap_is_group_erased(struct ftl_map *map, uint32_t group);
+
 /* Given the current user page, this function computes the page number of the
  * next user page by incrementing the page number. However, if incrementing the
  * page number results in the page number of a page containing page
@@ -215,7 +227,12 @@ int find_block_div(struct ftl_map *map)
  * use, as a block can only be erased as a whole. Therefore, if the first page
  * group is not in use, neither will the other page groups in a block.
  */
-static int find_block(struct ftl_map *map, struct ftl_page_group *group,
+#ifdef find_block
+#undef find_block
+#define find_block __real_find_block
+#endif
+
+int find_block(struct ftl_map *map, struct ftl_page_group *group,
 	uint32_t *where, uint32_t block)
 {
 	uint32_t page;
@@ -240,43 +257,46 @@ static int find_block(struct ftl_map *map, struct ftl_page_group *group,
 	return -1;
 }
 
+#ifdef find_block
+#undef find_block
+#define find_block __wrap_find_block
+#endif
+
+int find_block(struct ftl_map *map, struct ftl_page_group *group,
+	uint32_t *where, uint32_t block);
+
 /* Given the block number of the first block, attempts to use binary search to
  * find the last block that is in use.
  */
-static uint32_t find_last_block(struct ftl_map *map, uint32_t first)
+uint32_t find_last_block(struct ftl_map *map, uint32_t first)
 {
 	struct ftl_page_group group;
 	uint32_t mid, low = first, high = map->nblocks - 1;
 	uint32_t found, next;
 
-	while (low <= high) {
+	while (low < high) {
 		mid = (low + high) / 2;
 
 		if (find_block(map, &group, &found, mid) < 0 ||
 		    group.epoch != map->epoch) {
-			if (!mid)
-				return first;
-
 			high = mid - 1;
-
 			continue;
 		}
 
-		if (((found + 1) > map->nblocks) ||
-		    find_block(map, &group, &next, found + 1) < 0 ||
+		if (find_block(map, &group, &next, found + 1) < 0 ||
 		    group.epoch != map->epoch)
 			return found;
 
 		low = next;
 	}
 
-	return first;
+	return low;
 }
 
 /* Attempts to find the last page group that is in use within a block by
  * performing a binary search on the page groups.
  */
-static uint32_t find_last_group(struct ftl_map *map, uint32_t block)
+uint32_t find_last_group(struct ftl_map *map, uint32_t block)
 {
 	uint32_t ngroups = UINT32_C(1) << map->log2_groups_per_block;
 	uint32_t mid, low = 0, high = ngroups - 1;
@@ -284,7 +304,7 @@ static uint32_t find_last_group(struct ftl_map *map, uint32_t block)
 	low += block << map->log2_groups_per_block;
 	high += block << map->log2_groups_per_block;
 
-	while (low <= high) {
+	while (low < high) {
 		mid = (low + high) / 2;
 
 		if (is_group_erased(map, mid)) {
@@ -298,7 +318,7 @@ static uint32_t find_last_group(struct ftl_map *map, uint32_t block)
 		low = mid + 1;
 	}
 
-	return block << map->log2_groups_per_block;
+	return low;
 }
 
 static int find_root(struct ftl_map *map, uint32_t group)