diff options
Diffstat (limited to 'fs/minix/bitmap.c')
-rw-r--r-- | fs/minix/bitmap.c | 57 |
1 files changed, 25 insertions, 32 deletions
diff --git a/fs/minix/bitmap.c b/fs/minix/bitmap.c index 3f32bcb..4bc50da 100644 --- 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); } @@ -219,7 +209,7 @@ void minix_free_inode(struct inode * inode) mark_buffer_dirty(bh); } -struct inode *minix_new_inode(const struct inode *dir, int mode, int *error) +struct inode *minix_new_inode(const struct inode *dir, umode_t mode, int *error) { struct super_block *sb = dir->i_sb; struct minix_sb_info *sbi = minix_sb(sb); @@ -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); } |