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>

1 files changed, 5 insertions, 19 deletions

diff --git a/fs/qnx4/bitmap.c b/fs/qnx4/bitmap.c
index 22e0d60e53ef..76a7a697b778 100644
--- a/fs/qnx4/bitmap.c
+++ b/fs/qnx4/bitmap.c
@@ -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++;
         }