when there is no memory available to do so. Use the uvnode's strategy
routine to retrieve data from the device, rather than always using pread().
Add a buffer header flag that specifies external management of the buffer's
data area.
All of this in support of a new cleaner, which is not included in this commit.
the cache to grow in size irrespective of how many buffers may be in the
locked queue, since we can't write those in any case. Prevents fsck_lfs
from spinning when it has too much to write.
* Extend the lfs library from fsck_lfs(8) so that it can be used with a
not-yet-existent LFS. Make newfs_lfs(8) use this library, so it can
create LFSs whose Ifile is larger than one segment.
* Make newfs_lfs(8) use strsuftoi64() for its arguments, a la newfs(8).
* Make fsck_lfs(8) respect the "file system is clean" flag.
* Don't let fsck_lfs(8) think it has dirty blocks when invoked with the
-n flag.
