Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tyhicks...

[pandora-kernel.git] / fs / minix / bitmap.c

diff --git a/fs/minix/bitmap.c b/fs/minix/bitmap.c
index 3f32bcb..ef175cb 100644 (file)
--- a/fs/minix/bitmap.c
+++ b/fs/minix/bitmap.c
@@ -16,38 +16,26 @@
 #include <linux/bitops.h>
 #include <linux/sched.h>
 
-static const int nibblemap[] = { 4,3,3,2,3,2,2,1,3,2,2,1,2,1,1,0 };
-
 static DEFINE_SPINLOCK(bitmap_lock);
 
-static unsigned long count_free(struct buffer_head *map[], unsigned numblocks, __u32 numbits)
+/*
+ * bitmap consists of blocks filled with 16bit words
+ * bit set == busy, bit clear == free
+ * endianness is a mess, but for counting zero bits it really doesn't matter...
+ */
+static __u32 count_free(struct buffer_head *map[], unsigned blocksize, __u32 numbits)
 {
-       unsigned i, j, sum = 0;
-       struct buffer_head *bh;
-  
-       for (i=0; i<numblocks-1; i++) {
-               if (!(bh=map[i])) 
-                       return(0);
-               for (j=0; j<bh->b_size; j++)
-                       sum += nibblemap[bh->b_data[j] & 0xf]
-                               + nibblemap[(bh->b_data[j]>>4) & 0xf];
-       }
+       __u32 sum = 0;
+       unsigned blocks = DIV_ROUND_UP(numbits, blocksize * 8);
 
-       if (numblocks==0 || !(bh=map[numblocks-1]))
-               return(0);
-       i = ((numbits - (numblocks-1) * bh->b_size * 8) / 16) * 2;
-       for (j=0; j<i; j++) {
-               sum += nibblemap[bh->b_data[j] & 0xf]
-                       + nibblemap[(bh->b_data[j]>>4) & 0xf];
+       while (blocks--) {
+               unsigned words = blocksize / 2;
+               __u16 *p = (__u16 *)(*map++)->b_data;
+               while (words--)
+                       sum += 16 - hweight16(*p++);
        }
 
-       i = numbits%16;
-       if (i!=0) {
-               i = *(__u16 *)(&bh->b_data[j]) | ~((1<<i) - 1);
-               sum += nibblemap[i & 0xf] + nibblemap[(i>>4) & 0xf];
-               sum += nibblemap[(i>>8) & 0xf] + nibblemap[(i>>12) & 0xf];
-       }
-       return(sum);
+       return sum;
 }
 
 void minix_free_block(struct inode *inode, unsigned long block)
@@ -105,10 +93,12 @@ int minix_new_block(struct inode * inode)
        return 0;
 }
 
-unsigned long minix_count_free_blocks(struct minix_sb_info *sbi)
+unsigned long minix_count_free_blocks(struct super_block *sb)
 {
-       return (count_free(sbi->s_zmap, sbi->s_zmap_blocks,
-               sbi->s_nzones - sbi->s_firstdatazone + 1)
+       struct minix_sb_info *sbi = minix_sb(sb);
+       u32 bits = sbi->s_nzones - (sbi->s_firstdatazone + 1);
+
+       return (count_free(sbi->s_zmap, sb->s_blocksize, bits)
                << sbi->s_log_zone_size);
 }
 
@@ -273,7 +263,10 @@ struct inode *minix_new_inode(const struct inode *dir, int mode, int *error)
        return inode;
 }
 
-unsigned long minix_count_free_inodes(struct minix_sb_info *sbi)
+unsigned long minix_count_free_inodes(struct super_block *sb)
 {
-       return count_free(sbi->s_imap, sbi->s_imap_blocks, sbi->s_ninodes + 1);
+       struct minix_sb_info *sbi = minix_sb(sb);
+       u32 bits = sbi->s_ninodes + 1;
+
+       return count_free(sbi->s_imap, sb->s_blocksize, bits);
 }