udf: convert udf_count_free_bitmap to use bitmap_weight
replace handwritten bits counting with bitmap_weight
Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
diff --git a/fs/udf/super.c b/fs/udf/super.c
index 2666e5b..be0aa42 100644
--- a/fs/udf/super.c
+++ b/fs/udf/super.c
@@ -55,6 +55,7 @@
#include <linux/errno.h>
#include <linux/mount.h>
#include <linux/seq_file.h>
+#include <linux/bitmap.h>
#include <asm/byteorder.h>
#include "udf_sb.h"
@@ -1958,10 +1959,6 @@
return 0;
}
-static unsigned char udf_bitmap_lookup[16] = {
- 0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4
-};
-
static unsigned int udf_count_free_bitmap(struct super_block *sb,
struct udf_bitmap *bitmap)
{
@@ -1971,7 +1968,6 @@
int block = 0, newblock;
kernel_lb_addr loc;
uint32_t bytes;
- uint8_t value;
uint8_t *ptr;
uint16_t ident;
struct spaceBitmapDesc *bm;
@@ -1997,13 +1993,10 @@
ptr = (uint8_t *)bh->b_data;
while (bytes > 0) {
- while ((bytes > 0) && (index < sb->s_blocksize)) {
- value = ptr[index];
- accum += udf_bitmap_lookup[value & 0x0f];
- accum += udf_bitmap_lookup[value >> 4];
- index++;
- bytes--;
- }
+ u32 cur_bytes = min_t(u32, bytes, sb->s_blocksize - index);
+ accum += bitmap_weight((const unsigned long *)(ptr + index),
+ cur_bytes * 8);
+ bytes -= cur_bytes;
if (bytes) {
brelse(bh);
newblock = udf_get_lb_pblock(sb, loc, ++block);