This patch adds most of the plumbing for working file deletion in Ext2FS.
Directory entries are removed and inode link counts updated.
We don't yet update the inode or block bitmaps, I will do that separately.
Only booleans are supported at first. More types can be added easily.
Use this to add /proc/sys/wm_flash_flush which when enabled flashes pending
screen flush rects in yellow before they happen.
This synchronous approach to inodes is silly, obviously. I need to rework
it so that the in-memory CoreInode object is the canonical inode, and then
we just need a sync() that flushes pending changes to disk.
...by adding a new class called Ext2Inode that inherits CoreInode.
The idea is that a vnode will wrap a CoreInode rather than InodeIdentifier.
Each CoreInode subclass can keep whatever caches they like.
Right now, Ext2Inode caches the list of block indices since it can be very
expensive to retrieve.
- sys$readlink + readlink()
- Add a /proc/PID/exe symlink to the process's executable.
- Print symlink contents in ls output.
- Some work on plumbing options into VFS::open().
This is pretty inefficient for ext2fs. We walk the entire block group
containing the inode, searching through every directory for an entry
referencing this inode.
It might be a good idea to cache this information somehow. I'm not sure
how often we'll be searching for it.
Obviously there are multiple caching layers missing in the file system.
I also added a generator cache to FileHandle. This way, multiple
reads to a generated file (i.e in a synthfs) can transparently
handle multiple calls to read() without the contents changing
between calls.
The cache is discarded at EOF (or when the FileHandle is destroyed.)
