struct group_info init_groups = { .usage = ATOMIC_INIT(2) };

struct group_info *groups_alloc(int gidsetsize){

struct group_info *group_info;

int nblocks;

int i;

nblocks = (gidsetsize + NGROUPS_PER_BLOCK - 1) / NGROUPS_PER_BLOCK;

/* Make sure we always allocate at least one indirect block pointer */

nblocks = nblocks ? : 1;

group_info = kmalloc(sizeof(*group_info) + nblocks*sizeof(gid_t *), GFP_USER);

if (!group_info)

    return NULL;

group_info->ngroups = gidsetsize;

group_info->nblocks = nblocks;

atomic_set(&group_info->usage, 1);

if (gidsetsize <= NGROUPS_SMALL)

    group_info->blocks[0] = group_info->small_block;

else {

    for (i = 0; i < nblocks; i++) {

        gid_t *b;

        b = (void *)__get_free_page(GFP_USER);

        if (!b)

ERROR