EXT_FIRST_INDEX
fidx = EXT_FIRST_INDEX(neh);
curpath->ep_index = EXT_FIRST_INDEX(curpath->ep_header);
if (path[k+1].ep_index != EXT_FIRST_INDEX(path[k+1].ep_header))
if (path->ep_index < EXT_FIRST_INDEX(path->ep_header))
struct ext4_extent_index *ext_idx = EXT_FIRST_INDEX(eh);
l = EXT_FIRST_INDEX(eh) + 1;
r = EXT_FIRST_INDEX(eh) + le16toh(eh->eh_ecount) - 1;
#define EXT_LAST_INDEX(hdr) (EXT_FIRST_INDEX((hdr)) + le16toh((hdr)->eh_ecount) - 1)
#define EXT_MAX_INDEX(hdr) (EXT_FIRST_INDEX((hdr)) + le16toh((hdr)->eh_max) - 1)