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qnx4fs: use memweight() 

Use memweight() to count the total number of bits clear in memory area.

Note that this memweight() call can't be replaced with a single
bitmap_weight() call, although the pointer to the memory area is aligned
to long-word boundary.  Because the size of the memory area may not be a
multiple of BITS_PER_LONG, then it returns wrong value on big-endian
architecture.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Acked-by: Anders Larsen <al@alarsen.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Akinobu Mita 2012-07-30 14:40:57 -07:00 committed by Linus Torvalds
parent 639b9e34f1
commit 9b58f6d4aa
1 changed files with 5 additions and 19 deletions
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24
fs/qnx4/bitmap.c
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@ -17,23 +17,6 @@
#include <linux/bitops.h>
#include "qnx4.h"
static void count_bits(register const char *bmPart, register int size,
int *const tf)
{
char b;
int tot = *tf;
if (size > QNX4_BLOCK_SIZE) {
size = QNX4_BLOCK_SIZE;
}
do {
b = *bmPart++;
tot += 8 - hweight8(b);
size--;
} while (size != 0);
*tf = tot;
}
unsigned long qnx4_count_free_blocks(struct super_block *sb)
{
int start = le32_to_cpu(qnx4_sb(sb)->BitMap->di_first_xtnt.xtnt_blk) - 1;
@ -44,13 +27,16 @@ unsigned long qnx4_count_free_blocks(struct super_block *sb)
struct buffer_head *bh;
while (total < size) {
int bytes = min(size - total, QNX4_BLOCK_SIZE);
if ((bh = sb_bread(sb, start + offset)) == NULL) {
printk(KERN_ERR "qnx4: I/O error in counting free blocks\n");
break;
}
count_bits(bh->b_data, size - total, &total_free);
total_free += bytes * BITS_PER_BYTE -
memweight(bh->b_data, bytes);
brelse(bh);
total += QNX4_BLOCK_SIZE;
total += bytes;
offset++;
}