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Subject[PATCH 05/10] affs: use memweight()
Date
Use memweight() to count the total number of bits set in memory area.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: linux-fsdevel@vger.kernel.org
---
fs/affs/bitmap.c | 28 ++--------------------------
1 files changed, 2 insertions(+), 26 deletions(-)
diff --git a/fs/affs/bitmap.c b/fs/affs/bitmap.c
index 3e26271..3dfdcd2 100644
--- a/fs/affs/bitmap.c
+++ b/fs/affs/bitmap.c
@@ -10,30 +10,6 @@
#include <linux/slab.h>
#include "affs.h"

-/* This is, of course, shamelessly stolen from fs/minix */
-
-static const int nibblemap[] = { 0,1,1,2,1,2,2,3,1,2,2,3,2,3,3,4 };
-
-static u32
-affs_count_free_bits(u32 blocksize, const void *data)
-{
- const u32 *map;
- u32 free;
- u32 tmp;
-
- map = data;
- free = 0;
- for (blocksize /= 4; blocksize > 0; blocksize--) {
- tmp = *map++;
- while (tmp) {
- free += nibblemap[tmp & 0xf];
- tmp >>= 4;
- }
- }
-
- return free;
-}
-
u32
affs_count_free_blocks(struct super_block *sb)
{
@@ -317,7 +293,7 @@ int affs_init_bitmap(struct super_block *sb, int *flags)
goto out;
}
pr_debug("AFFS: read bitmap block %d: %d\n", blk, bm->bm_key);
- bm->bm_free = affs_count_free_bits(sb->s_blocksize - 4, bh->b_data + 4);
+ bm->bm_free = memweight(bh->b_data + 4, sb->s_blocksize - 4);

/* Don't try read the extension if this is the last block,
* but we also need the right bm pointer below
@@ -367,7 +343,7 @@ int affs_init_bitmap(struct super_block *sb, int *flags)

/* recalculate bitmap count for last block */
bm--;
- bm->bm_free = affs_count_free_bits(sb->s_blocksize - 4, bh->b_data + 4);
+ bm->bm_free = memweight(bh->b_data + 4, sb->s_blocksize - 4);

out:
affs_brelse(bh);
--
1.7.7.6


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