Enable the creation of lfs64 volumes.

To create an lfs64 volume, use -w 64. You can also force a 32-bit
volume with -w 32, but this will fail on devices thta are too large.

lfs64 is the default for devices > 1TB. (1TB rather than 2TB because
daddr_t is signed and negative block numbers can cause interesting
complications.)

For now print a warning that the lfs64 format isn't finalized, because
it isn't. For now any lfs64 use should be limited to test data,
benchmarking, and so forth.

Add a (draft) 64-bit superblock. Make things build again.

Add pieces of support for using both superblock types where
convenient, and specifically to the superblock accessors, but don't
actually enable it anywhere.

First substantive step on PR 50000.

lfs_sb_cksum returns a uint32_t, not a u_long

branches: 1.11.8; 1.11.10;
Deal with wedges and the new disk geometry structures, instead of using
struct disklabel. From Christos Zoulas.

- log2() -> lfs_log2().
- fix a couple of entries in struct lfs lfs_default:
- in a comment, it's called dlfs_freehd now
- dlfs_inodefmt comes after dlfs_tstamp. fortunately for this
one, LFS_44INODEFMT is also 0 so the right thing was happening.

newfs_lfs(8) compoment of the recent superblock parameter addition. Change
the wording of the explanation of the -M option, detail a new -R option
that controls initial setting of the new parameter.

branches: 1.8.6;
Stop superblock being written to sector 0 for small filesystems.
Honour the '-s size' command option.
Allow an LFS filesystem to be created in a file.

Move UCB-licensed code from 4-clause to 3-clause licence.

Patches provided by Joel Baker in PR 22308, verified by myself.

Bump daddr_t to 64 bits. Replace it with int32_t in all places where
it was used on-disk, so that on-disk formats remain the same.
Remove ufs_daddr_t and ufs_lbn_t for the time being.

Merge the short-lived perseant-lfsv2 branch into the trunk.

Kernels and tools understand both v1 and v2 filesystems; newfs_lfs
generates v2 by default. Changes for the v2 layout include:

- Segments of non-PO2 size and arbitrary block offset, so these can be
matched to convenient physical characteristics of the partition (e.g.,
stripe or track size and offset).

- Address by fragment instead of by disk sector, paving the way for
non-512-byte-sector devices. In theory fragments can be as large
as you like, though in reality they must be smaller than MAXBSIZE in size.

- Use serial number and filesystem identifier to ensure that roll-forward
doesn't get old data and think it's new. Roll-forward is enabled for
v2 filesystems, though not for v1 filesystems by default.

- The inode free list is now a tailq, paving the way for undelete (undelete
is not yet implemented, but can be without further non-backwards-compatible
changes to disk structures).

- Inode atime information is kept in the Ifile, instead of on the inode;
that is, the inode is never written *just* because atime was changed.
Because of this the inodes remain near the file data on the disk, rather
than wandering all over as the disk is read repeatedly. This speeds up
repeated reads by a small but noticeable amount.

Other changes of note include:

- The ifile written by newfs_lfs can now be of arbitrary length, it is no
longer restricted to a single indirect block.

- Fixed an old bug where ctime was changed every time a vnode was created.
I need to look more closely to make sure that the times are only updated
during write(2) and friends, not after-the-fact during a segment write,
and certainly not by the cleaner.

branches: 1.4.2;
Add "-A" option to autoconfigure the segment size based on measured
bandwidth and seek time of the disk, using the "4 * bandwidth * seek
time" formula from Neefe-Matthews' 1997 paper. An RZ25 disk with this
option gets 200K segments. Reference the paper in the manual page.

Format string cleanups by Bill Sommerfeld.

Tweak how lfs_avail is initialized, corresponding to changes in the
kernel.

Don't make more superblock segments than we have a record of in
the superblock; and print these out as we go, like newfs.

Add am "-M" flag to specify the number of reserved segments, with a note
in the man page not to use it.

branches: 1.1.2; 1.1.10;
Change name of newlfs to newfs_lfs.