When a process wants something done from VFS, but VFS has no worker
threads available, the request is stored and executed later. However,
when PM also sends a request for that process at the same time, discard
the pending request from the process and give priority to PM. The request
PM sends is either an EXIT or a DUMPCORE request, so we're not interested
in executing the pending request anyway.
This driver can be loaded as an overlay on top of a real block
device, and can then be used to generate block-level failures for
certain transfer requests. Specifically, a rule-based system allows
the user to introduce (overt and silent) data corruption and errors.
It exposes itself through /dev/fbd, and a file system can be mounted
on top of it. The new fbdctl(8) tool can be used to control the
driver; see ``man fbdctl'' for details. It also comes with a test
set, located in test/fbdtest.
This removes a race condition when the block driver performs a
complete restart after a crash (the new default). If any user of
the driver finds out its new endpoint and sends a request to the
new driver instance before this instance has had the chance to
initialize, then its initialization would clear all IPC state and
thereby erroneously cancel the incoming request. Clearing IPC
state is only desired upon a stateful restart (where the driver's
endpoint is retained). This information is now passed to and used
by libblockdriver accordingly.
The test script now resolves the device node into a <label,minor>
pair, so that the blocktest driver itself no longer has to. This
removes blocktest's dependency on VFS' internal data structures.
Also allow blocktest to be linked using with gcc/clang.
This patch provides basic protection against damage resulting from
differently compiled servers blindly copying tables to one another.
In every getsysinfo() call, the caller is provided with the expected
size of the requested data structure. The callee fails the call if
the expected size does not match the data structure's actual size.
This stops the printer driver from hanging the entire system when
/dev/lp is opened on systems that do not have a parallel port. With
this change, the printer driver shuts down immediately after loading
on such systems.
Using sendrec directly only results in problems. While it is not
clear whether using fs_sendrec is the best option, it is at least
an improvement.
Also remove some legacy cruft.
Each block driver now gets to specify whether it is a disk block
driver, which implies it wants the library to handle getting and
setting partitions for it.
The NetBSD libc provides a mechanism to have versions of system calls.
By 'renaming' symbols to a new version, freshly compiled programs will
automatically use the new symbol iff they use the proper header files. The
old, not renamed, version of the symbol will still exist (after being moved
to the compat directory), so old programs can still link.
Since MINIX doesn't support dynamic linking, the whole rename mechanism
doesn't really work for us. However, removing it would create a huge diff
with the current NetBSD libc.
A lot of the compat code relies on things we don't (seem to) have, and
therefore does not get built and linked. This causes trouble for tools like
autoconf, which will fail to find the renamed symbols. For example,
currently select gets renamed to __select50 in libc. Autoconf looks for
'select' and doesn't find it and reports we don't have it. This is where
the compat.S stub comes into play: it generates the old symbols and jumps to
the new symbols. However, as this is done in one object file, all renamed
symbols get linked together, causing binaries to be huge. This patch fixes
that by generating an object file for each renamed symbol.
This patch also makes the MISSING_SYSCALLS more complete and marginally
reduces the diff with NetBSD.
The implementation is in libblockdriver, and works transparently for
all block drivers. The new btrace(8) tool can be used to control block
tracing; see ``man btrace'' for details.
