e2fsprogs: Why __uint64_t in unix_discard() in lib/ext2fs/unix_io.c?

In e2fsprogs commit e90a59ed434d6c5e38dd148aa4ba5b22b8f7eb24 the unix_discard() function was implemented. Sorry, I was not subscribed when that patch went to the list or I would have replied to it.

In unix_discard() in e2fsprogs lib/ext2fs/unix_io.c, starting at line 922 on the current git master branch HEAD, the __uint64_t type is used for the range[] array which is used to perform an ioctl(). But, the BLKDISCARD ioctl() in the kernel uses uint64_t types to specify the range.

Why is __uint64_t used in e2fsprogs's unix_discard() function? It's not clear to me. This is the only use of __uint64_t in all of e2fsprogs.

Why wouldn't uint64_t work here?

Thanks,
Andrew