ubi: Use bitmaps in Fastmap self-check code

...don't waste memory by allocating one sizeof(int) per
PEB.
Signed-off-by: Richard Weinberger <richard@nod.at>

drivers/mtd/ubi/fastmap.c

@@ -15,20 +15,22 @@
  */
 
 #include <linux/crc32.h>
+#include <linux/bitmap.h>
 #include "ubi.h"
 
 /**
  * init_seen - allocate memory for used for debugging.
  * @ubi: UBI device description object
  */
-static inline int *init_seen(struct ubi_device *ubi)
+static inline unsigned long *init_seen(struct ubi_device *ubi)
 {
-	int *ret;
+	unsigned long *ret;
 
 	if (!ubi_dbg_chk_fastmap(ubi))
 		return NULL;
 
-	ret = kcalloc(ubi->peb_count, sizeof(int), GFP_KERNEL);
+	ret = kcalloc(BITS_TO_LONGS(ubi->peb_count), sizeof(unsigned long),
+		      GFP_KERNEL);
 	if (!ret)
 		return ERR_PTR(-ENOMEM);
 
@@ -39,7 +41,7 @@ static inline int *init_seen(struct ubi_device *ubi)
  * free_seen - free the seen logic integer array.
  * @seen: integer array of @ubi->peb_count size
  */
-static inline void free_seen(int *seen)
+static inline void free_seen(unsigned long *seen)
 {
 	kfree(seen);
 }
@@ -50,12 +52,12 @@ static inline void free_seen(int *seen)
  * @pnum: The PEB to be makred as seen
  * @seen: integer array of @ubi->peb_count size
  */
-static inline void set_seen(struct ubi_device *ubi, int pnum, int *seen)
+static inline void set_seen(struct ubi_device *ubi, int pnum, unsigned long *seen)
 {
 	if (!ubi_dbg_chk_fastmap(ubi) || !seen)
 		return;
 
-	seen[pnum] = 1;
+	set_bit(pnum, seen);
 }
 
 /**
@@ -63,7 +65,7 @@ static inline void set_seen(struct ubi_device *ubi, int pnum, int *seen)
  * @ubi: UBI device description object
  * @seen: integer array of @ubi->peb_count size
  */
-static int self_check_seen(struct ubi_device *ubi, int *seen)
+static int self_check_seen(struct ubi_device *ubi, unsigned long *seen)
 {
 	int pnum, ret = 0;
 
@@ -71,7 +73,7 @@ static int self_check_seen(struct ubi_device *ubi, int *seen)
 		return 0;
 
 	for (pnum = 0; pnum < ubi->peb_count; pnum++) {
-		if (!seen[pnum] && ubi->lookuptbl[pnum]) {
+		if (test_bit(pnum, seen) && ubi->lookuptbl[pnum]) {
 			ubi_err(ubi, "self-check failed for PEB %d, fastmap didn't see it", pnum);
 			ret = -EINVAL;
 		}
@@ -1139,7 +1141,7 @@ static int ubi_write_fastmap(struct ubi_device *ubi,
 	struct rb_node *tmp_rb;
 	int ret, i, j, free_peb_count, used_peb_count, vol_count;
 	int scrub_peb_count, erase_peb_count;
-	int *seen_pebs = NULL;
+	unsigned long *seen_pebs = NULL;
 
 	fm_raw = ubi->fm_buf;
 	memset(ubi->fm_buf, 0, ubi->fm_size);