implementation didn't used a good random generator, this is not true
anymore since arc4random(3) is used these days.
Pointed out by Jeff Ito in PR/30321
64 bit block pointers, extended attribute storage, and a few
other things.
This commit does not yet include the code to manipulate the extended
storage (for e.g. ACLs), this will be done later.
Originally written by Kirk McKusick and Network Associates Laboratories for
FreeBSD.
determine the endianness of the `struct fs *o' superblock from o->fs_magic
and set needswap as necessary, rather than trusting the caller to get
it right. invariably, almost every caller of ffs_sb_swap() was calling it
with ns set to the wrong value for ns anyway!
ansi KNF ffs_bswap.c declarations whilst here.
this fixes all sorts of problems when trying to use other-endian file systems,
notably the kernel trying to access memory *way* off, possibly corrupting or
panicing, and userland programs SEGVing and/or corrupting things (e.g,
"fsck_ffs -B" to swap a file system endianness).
whilst the previous rev of ffs_bswap.c (1.10, 2000/12/23) made this problem
worse, i suspect that the problem was always there and previous versions
just happened not to trash things at the wrong time.
FFS_EI should now be a lot more stable.
