static unsigned long descriptor_loc(struct super_block *sb,
unsigned long logic_sb_block,
int nr)
{
struct ext2_sb_info *sbi = EXT2_SB(sb);
unsigned long bg, first_meta_bg;
int has_super = 0;
first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
nr < first_meta_bg)
return (logic_sb_block + nr + 1);
bg = sbi->s_desc_per_block * nr;
if (ext2_bg_has_super(sb, bg))
has_super = 1;
return ext2_group_first_block_no(sb, bg) + has_super;
}
static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
{
struct super_block *sb = dentry->d_sb;
struct ext2_sb_info *sbi = EXT2_SB(sb);
struct ext2_super_block *es = sbi->s_es;
u64 fsid;
if (test_opt (sb, MINIX_DF))
sbi->s_overhead_last = 0;
else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
unsigned long i, overhead = 0;
smp_rmb();
/*
* Compute the overhead (FS structures). This is constant
* for a given filesystem unless the number of block groups
* changes so we cache the previous value until it does.
*/
/*
* All of the blocks before first_data_block are
* overhead
*/
overhead = le32_to_cpu(es->s_first_data_block);
/*
* Add the overhead attributed to the superblock and
* block group descriptors. If the sparse superblocks
* feature is turned on, then not all groups have this.
*/
for (i = 0; i < sbi->s_groups_count; i++)
overhead += ext2_bg_has_super(sb, i) +
ext2_bg_num_gdb(sb, i);
/*
* Every block group has an inode bitmap, a block
* bitmap, and an inode table.
*/
overhead += (sbi->s_groups_count *
(2 + sbi->s_itb_per_group));
sbi->s_overhead_last = overhead;
smp_wmb();
sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
}
buf->f_type = EXT2_SUPER_MAGIC;
buf->f_bsize = sb->s_blocksize;
buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
buf->f_bfree = ext2_count_free_blocks(sb);
es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
buf->f_bavail = 0;
buf->f_files = le32_to_cpu(es->s_inodes_count);
buf->f_ffree = ext2_count_free_inodes(sb);
es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
buf->f_namelen = EXT2_NAME_LEN;
fsid = le64_to_cpup((void *)es->s_uuid) ^
le64_to_cpup((void *)es->s_uuid + sizeof(u64));
buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
return 0;
}