/*
* find_free_range: find an unused consecutive sequence of ids to allocate
* to a user.
* @db: database to search
* @min: the first uid in the range to find
* @max: the highest uid to find
* @count: the number of uids needed
*
* Return the lowest new uid, or ULONG_MAX on failure.
*/
static unsigned long find_free_range(struct commonio_db *db,
unsigned long min, unsigned long max,
unsigned long count)
{
const struct subordinate_range *range;
unsigned long low, high;
/* When given invalid parameters fail */
if ((count == 0) || (max < min))
goto fail;
/* Sort by range then by owner */
commonio_sort (db, subordinate_range_cmp);
commonio_rewind(db);
low = min;
while ((range = commonio_next(db)) != NULL) {
unsigned long first = range->start;
unsigned long last = first + range->count - 1;
/* Find the top end of the hole before this range */
high = first;
/* Don't allocate IDs after max (included) */
if (high > max + 1) {
high = max + 1;
}
/* Is the hole before this range large enough? */
if ((high > low) && ((high - low) >= count))
return low;
/* Compute the low end of the next hole */
if (low < (last + 1))
low = last + 1;
if (low > max)
goto fail;
}
/* Is the remaining unclaimed area large enough? */
if (((max - low) + 1) >= count)
return low;
fail:
return ULONG_MAX;
}
/* Sort entries by GID */
int gr_sort ()
{
return commonio_sort (&group_db, gr_cmp);
}
/* Sort entries by UID */
int pw_sort ()
{
return commonio_sort (&passwd_db, pw_cmp);
}
