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>

diff --git a/fs/qnx4/bitmap.c b/fs/qnx4/bitmap.c
index 22e0d60e53efbe3072ade881ec69251062df83c9..76a7a697b778d7918e5db75bf5a1dd744a073a5d 100644 (file)
--- 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++;
        }