In the future, we should allow mounting any block device. At the moment
there is too much filesystem code that depends on the underlying device
being a DiskDevice.
- You must now have superuser privileges to use mount().
- We now verify that the mount point is a valid path first, before
trying to find a filesystem on the specified device.
- Convert some dbgprintf() to dbg().
It is now possible to mount ext2 `DiskDevice` devices under Serenity on
any folder in the root filesystem. Currently any user can do this with
any permissions. There's a fair amount of assumptions made here too,
that might not be too good, but can be worked on in the future. This is
a good start to allow more dynamic operation under the OS itself.
It is also currently impossible to unmount and such, and devices will
fail to mount in Linux as the FS 'needs to be cleaned'. I'll work on
getting `umount` done ASAP to rectify this (as well as working on less
assumption-making in the mount syscall. We don't want to just be able
to mount DiskDevices!). This could probably be fixed with some `-t`
flag or something similar.
Use AK::exchange() to switch out the internal storage. Also mark these
functions with [[nodiscard]] to provoke an compile-time error if they
are called without using the return value.
This gives us much better error messages when you try to use them.
Without this change, it would complain about the absence of functions
named ref() and deref() on RefPtr itself. With it, we instead get a
"hey, this function is deleted" error.
Change operator=(T&) to operator=T(const T&) also, to keep assigning
a const T& to a NonnullRefPtr working.
Instead of aborting the program when we hit an assertion, just print a
message and keep going.
This allows us to write tests that provoke assertions on purpose.
We were forgetting where we put the userspace thread stacks, so added a
member called Thread::m_userspace_thread_stack to keep track of it.
Then, in ~Thread(), we now deallocate the userspace, kernel and signal
stacks (if present.)
Out of curiosity, the "init_stage2" process doesn't have a kernel stack
which I found surprising. :^)
There was a bug in the "prepend_vector_object" test but it was masked
by us not printing failures. (The bug was that we were adding three
elements to the "objects" vector and then checking that another
vector called "more_objects" indeed had three elements. Oops!)
This is a complement to append() that works by constructing the new
element in-place via placement new and forwarded constructor arguments.
The STL calls this emplace_back() which looks ugly, so I'm inventing
a nice word for it instead. :^)
Furthermore, fread() has already handled EOF, so there's no need to do
it again. If we read a character, return it, otherwise return EOF.
Note that EOF means "EOF or error" here.
There's some confusion between the write syscall and CIODevice::write()
here. The internal write() returns a boolean, and has already whined
in case the syscall failed, so we don't need to do that again.
