shithub: lwext4

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Fix lru/lba compare functions: possible overflow

Functions will not work for lba values:
 - 0x100000001ULL - 0x000000001UL

It won't work also for 16 int architectures. So it is better to
implement this functions using if/else if statements.

--- a/lwext4/ext4_bcache.c

+++ b/lwext4/ext4_bcache.c

@@ -42,18 +42,22 @@

 #include <string.h>

 #include <stdlib.h>

-static int

-ext4_bcache_lba_compare(struct ext4_buf *a,

-			struct ext4_buf *b)

+static int ext4_bcache_lba_compare(struct ext4_buf *a, struct ext4_buf *b)

 {

-	return a->lba - b->lba;

+	 if (a->lba > b->lba)

+		 return 1;

+	 else if (a->lba < b->lba)

+		 return -1;

+	 return 0;

 }

-static int

-ext4_bcache_lru_compare(struct ext4_buf *a,

-			struct ext4_buf *b)

+static int ext4_bcache_lru_compare(struct ext4_buf *a, struct ext4_buf *b)

 {

-	return a->lru_id - b->lru_id;

+	if (a->lru_id > b->lru_id)

+		return 1;

+	else if (a->lru_id < b->lru_id)

+		return -1;

+	return 0;

 }

 RB_GENERATE_INTERNAL(ext4_buf_lba, ext4_buf, lba_node,