2007-02-20 07:54:29

by vignesh babu

[permalink] [raw]
Subject: [KJ][PATCH] is_power_of_2 in fs/block_dev.c

Replacing (n & (n-1)) in the context of power of 2 checks
with is_power_of_2


Signed-off-by: vignesh babu <[email protected]>
---
diff --git a/fs/block_dev.c b/fs/block_dev.c
index fc7028b..e8f2a2b 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -22,6 +22,7 @@
#include <linux/mount.h>
#include <linux/uio.h>
#include <linux/namei.h>
+#include <linux/log2.h>
#include <asm/uaccess.h>
#include "internal.h"

@@ -65,7 +66,7 @@ static void kill_bdev(struct block_device *bdev)
int set_blocksize(struct block_device *bdev, int size)
{
/* Size must be a power of two, and between 512 and PAGE_SIZE */
- if (size > PAGE_SIZE || size < 512 || (size & (size-1)))
+ if (size > PAGE_SIZE || size < 512 || !is_power_of_2(size))
return -EINVAL;

/* Size cannot be smaller than the size supported by the device */

--
Regards,
Vignesh Babu BM
_____________________________________________________________
"Why is it that every time I'm with you, makes me believe in magic?"