[PATCH] ntfs: Use bitmap_weight

From: Akinobu Mita
Date: Sun Nov 15 2009 - 22:08:12 EST


Use bitmap_weight instead of doing hweight32 for each u32 element
in page

Signed-off-by: Akinobu Mita <akinobu.mita@xxxxxxxxx>
Cc: Anton Altaparmakov <aia21@xxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: linux-ntfs-dev@xxxxxxxxxxxxxxxxxxxxx
---
fs/ntfs/super.c | 25 +++++++++++++------------
1 files changed, 13 insertions(+), 12 deletions(-)

diff --git a/fs/ntfs/super.c b/fs/ntfs/super.c
index 80b0477..55be660 100644
--- a/fs/ntfs/super.c
+++ b/fs/ntfs/super.c
@@ -31,6 +31,7 @@
#include <linux/vfs.h>
#include <linux/moduleparam.h>
#include <linux/smp_lock.h>
+#include <linux/bitmap.h>

#include "sysctl.h"
#include "logfile.h"
@@ -2457,7 +2458,6 @@ static void ntfs_put_super(struct super_block *sb)
static s64 get_nr_free_clusters(ntfs_volume *vol)
{
s64 nr_free = vol->nr_clusters;
- u32 *kaddr;
struct address_space *mapping = vol->lcnbmp_ino->i_mapping;
struct page *page;
pgoff_t index, max_index;
@@ -2476,7 +2476,8 @@ static s64 get_nr_free_clusters(ntfs_volume *vol)
ntfs_debug("Reading $Bitmap, max_index = 0x%lx, max_size = 0x%lx.",
max_index, PAGE_CACHE_SIZE / 4);
for (index = 0; index < max_index; index++) {
- unsigned int i;
+ unsigned long *kaddr;
+
/*
* Read the page from page cache, getting it from backing store
* if necessary, and increment the use count.
@@ -2489,16 +2490,16 @@ static s64 get_nr_free_clusters(ntfs_volume *vol)
nr_free -= PAGE_CACHE_SIZE * 8;
continue;
}
- kaddr = (u32*)kmap_atomic(page, KM_USER0);
+ kaddr = kmap_atomic(page, KM_USER0);
/*
- * For each 4 bytes, subtract the number of set bits. If this
+ * Subtract the number of set bits. If this
* is the last page and it is partial we don't really care as
* it just means we do a little extra work but it won't affect
* the result as all out of range bytes are set to zero by
* ntfs_readpage().
*/
- for (i = 0; i < PAGE_CACHE_SIZE / 4; i++)
- nr_free -= (s64)hweight32(kaddr[i]);
+ nr_free -= bitmap_weight(kaddr,
+ PAGE_CACHE_SIZE * BITS_PER_BYTE);
kunmap_atomic(kaddr, KM_USER0);
page_cache_release(page);
}
@@ -2537,7 +2538,6 @@ static s64 get_nr_free_clusters(ntfs_volume *vol)
static unsigned long __get_nr_free_mft_records(ntfs_volume *vol,
s64 nr_free, const pgoff_t max_index)
{
- u32 *kaddr;
struct address_space *mapping = vol->mftbmp_ino->i_mapping;
struct page *page;
pgoff_t index;
@@ -2547,7 +2547,8 @@ static unsigned long __get_nr_free_mft_records(ntfs_volume *vol,
ntfs_debug("Reading $MFT/$BITMAP, max_index = 0x%lx, max_size = "
"0x%lx.", max_index, PAGE_CACHE_SIZE / 4);
for (index = 0; index < max_index; index++) {
- unsigned int i;
+ unsigned long *kaddr;
+
/*
* Read the page from page cache, getting it from backing store
* if necessary, and increment the use count.
@@ -2560,16 +2561,16 @@ static unsigned long __get_nr_free_mft_records(ntfs_volume *vol,
nr_free -= PAGE_CACHE_SIZE * 8;
continue;
}
- kaddr = (u32*)kmap_atomic(page, KM_USER0);
+ kaddr = kmap_atomic(page, KM_USER0);
/*
- * For each 4 bytes, subtract the number of set bits. If this
+ * Subtract the number of set bits. If this
* is the last page and it is partial we don't really care as
* it just means we do a little extra work but it won't affect
* the result as all out of range bytes are set to zero by
* ntfs_readpage().
*/
- for (i = 0; i < PAGE_CACHE_SIZE / 4; i++)
- nr_free -= (s64)hweight32(kaddr[i]);
+ nr_free -= bitmap_weight(kaddr,
+ PAGE_CACHE_SIZE * BITS_PER_BYTE);
kunmap_atomic(kaddr, KM_USER0);
page_cache_release(page);
}
--
1.6.5.1

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