diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 22158eb..fc3eb79 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1415,8 +1415,6 @@
 	sb->s_flags = s_flags; /* Restore MS_RDONLY status */
 }
 
-#define log2(n) ffz(~(n))
-
 /*
  * Maximal file size.  There is a direct, and {,double-,triple-}indirect
  * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
@@ -1689,8 +1687,8 @@
 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
 	sbi->s_sbh = bh;
 	sbi->s_mount_state = le16_to_cpu(es->s_state);
-	sbi->s_addr_per_block_bits = log2(EXT4_ADDR_PER_BLOCK(sb));
-	sbi->s_desc_per_block_bits = log2(EXT4_DESC_PER_BLOCK(sb));
+	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
+	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
 	for (i=0; i < 4; i++)
 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
 	sbi->s_def_hash_version = es->s_def_hash_version;