runlist_element * ntfs_rl_realloc (runlist_element * rl, int old_size, int new_size);
As the runlists grow, more memory will be required. To prevent the kernel having to allocate and reallocate large numbers of small bits of memory, this function returns an entire page of memory.
It is up to the caller to serialize access to the runlist rl.
N.B. If the new allocation doesn't require a different number of pages in memory, the function will return the original pointer.
On success, return a pointer to the newly allocated, or recycled, memory. On error, return -errno. The following error codes are defined: -ENOMEM - Not enough memory to allocate runlist array. -EINVAL - Invalid parameters were passed in.