The main motivation for this change is that only Loris supports
multithreading, and Loris supports dynamic thread allocation, so the
number of supported threads can be implemented as a bit flag (i.e.,
either 1 or "at least as many as VFS has"). The ABI break obviates the
need to support file system versioning at this time, and several
other aspects are better implemented as flags as well. Other changes:
- replace peek/bpeek test upon mount with FS flag as well;
- mark libsffs as 64-bit file size capable;
- remove old (3.2.1) getdents support.
Change-Id: I313eace9c50ed816656c31cd47d969033d952a03
Add primary cache management feature to libminixfs as mfs and ext2
currently do separately, remove cache code from mfs and ext2, and make
them use the libminixfs interface. This makes all fields of the buf
struct private to libminixfs and FS clients aren't supposed to access
them at all. Only the opaque 'void *data' field (the FS block contents,
used to be called bp) is to be accessed by the FS client.
The main purpose is to implement the interface to the 2ndary vm cache
just once, get rid of some code duplication, and add a little
abstraction to reduce the code inertia of the whole caching business.
Some minor sanity checking and prohibition done by mfs in this code
as removed from the generic primary cache code as a result:
- checking all inodes are not in use when allocating/resizing
the cache
- checking readonly filesystems aren't written to
- checking the superblock isn't written to on mounted filesystems
The minixfslib code relies on fs_blockstats() in the client filesystem to
return some FS usage information.
