All functions prefixed with bdev_ are moved into bdev.c, and those
prefixed with cdev_ are now in cdev.c. The code in both files are
converted to KNF. The little (IOCTL-related) code left in device.c
is also cleaned up but should probably be moved into other existing
source files. This is left to a future patch. In general, VFS is
long overdue for a source code rebalancing, and the patch here is
only a step in the right direction.
Change-Id: I2fb25734b5778b44f2ff6d2ce331a8e2146e20b0
Previously, VFS would use various subsets of a number of fproc
structure fields to store state when the process is blocked
(suspended) for various reasons. As a result, there was a fair
amount of abuse of fields, hidden state, and confusion as to
which fields were used with which suspension states.
Instead, the suspension state is now split into per-state
structures, which are then stored in a union. Each of the union's
structures should be accessed only right before, during, and right
after the fp_blocked_on field is set to the corresponding blocking
type. As a result, it is now very clear which fields are in use
at which times, and we even save a bit of memory as a side effect.
Change-Id: I5c24e353b6cb0c32eb41c70f89c5cfb23f6c93df
By now it has become clear that the VFS select code has an unusually
high concentration of bugs, and there is no indication that any form
of convergence to a bug-free state is in sight. Thus, for now, it
may be helpful to be able to dump the contents of the select tables
in order to track down any bugs in the future. Hopefully that will
allow the next bugs to be resolved slightly after than before.
The debug dump can be triggered with "svrctl vfs get print_select".
Change-Id: Ia826746dce0f065d7f3b46aa9047945067b8263d
Now that clock_t is an unsigned value, we can also allow the system
uptime to wrap. Essentially, instead of using (a <= b) to see if time
a occurs no later than time b, we use (b - a <= CLOCK_MAX / 2). The
latter value does not exist, so instead we add TMRDIFF_MAX for that
purpose.
We must therefore also avoid using values like 0 and LONG_MAX as
special values for absolute times. This patch extends the libtimers
interface so that it no longer uses 0 to indicate "no timeout".
Similarly, TMR_NEVER is now used as special value only when
otherwise a relative time difference would be used. A minix_timer
structure is now considered in use when it has a watchdog function set,
rather than when the absolute expiry time is not TMR_NEVER. A few new
macros in <minix/timers.h> help with timer comparison and obtaining
properties from a minix_timer structure.
This patch also eliminates the union of timer arguments, instead using
the only union element that is only used (the integer). This prevents
potential problems with e.g. live update. The watchdog function
prototype is changed to pass in the argument value rather than a
pointer to the timer structure, since obtaining the argument value was
the only current use of the timer structure anyway. The result is a
somewhat friendlier timers API.
The VFS select code required a few more invasive changes to restrict
the timer value to the new maximum, effectively matching the timer
code in PM. As a side effect, select(2) has been changed to reject
invalid timeout values. That required a change to the test set, which
relied on the previous, erroneous behavior.
Finally, while we're rewriting significant chunks of the timer code
anyway, also covert it to KNF and add a few more explanatory comments.
Change-Id: Id43165c3fbb140b32b90be2cca7f68dd646ea72e
Currently, the BSD socket API is implemented in libc, translating the
API calls to character driver operations underneath. This approach
has several issues:
- it is inefficient, as most character driver operations are specific
to the socket type, thus requiring that each operation start by
bruteforcing the socket protocol family and type of the given file
descriptor using several system calls;
- it requires that libc itself be changed every time system support
for a new protocol is added;
- various parts of the libc implementations violate the asynchronous
signal safety POSIX requirements.
In order to resolve all these issues at once, the plan is to turn the
BSD socket calls into system calls, thus making the BSD socket API the
"native" ABI, removing the complexity from libc and instead letting
VFS deal with the socket calls.
The overall change is going to break all networking functionality. In
order to smoothen the transition, this patch introduces the fifteen
new BSD socket system calls, and makes libc try these first before
falling back on the old behavior. For now, the VFS implementations of
the new calls fail such that libc will always use the fallback cases.
Later on, when we introduce the actual implementation of the native
BSD socket calls, all statically linked programs will automatically
use the new ABI, thus limiting actual application breakage.
In other words: by itself, this patch does nothing, except add a bit
of transitional overhead that will disappear in the future. The
largest part of the patch is concerned with adding full support for
the new BSD socket system calls to trace(1) - this early addition has
the advantage of making system call tracing output of several socket
calls much more readable already.
Both the system call interfaces and the trace(1) support have already
been tested using code that will be committed later on.
Change-Id: I3460812be50c78be662d857f9d3d6840f3ca917f
- do not allow live update for request and protocol free states if
there are any worker threads that have pending or active work;
- destroy all worker threads before such live updates and recreate
them afterwards, because transferring (the contents of) the
thread stacks is not an option at this time;
- recreate worker threads in the new instance only if they were
shut down before the state transfer, by letting RS provide the
original preparation state as initialization information.
Change-Id: I846225f5b7281f19e69175485f2c88a4b4891dc2
For dynamically linked executables, the interpreter is passed a
file descriptor of the binary being executed. To this end, VFS
opens the target executable, but opening the file fails if it is
not readable, even when it is executable. With this patch, when
opening the executable, it verifies the X bit rather than the R
bit on the file, thus allowing the execution of dynamically
linked binaries that are executable but not readable.
Add test86 to verify correctness.
Change-Id: If3514add6a33b33d52c05a0a627d757bff118d77
For VFS, initialization is a special case for processing work: PFS
and the ramdisk MFS must be fully mounted before VFS can process any
other requests, in particular from init(8). This case was handled by
receiving reply messages only from the FS service being mounted, but
this effectively disallowed PFS from calling setuid(2) at startup.
This patch lets VFS receive all messages during the mounting process,
but defer processing any new requests. As a result, the FS services
have a bit more freedom in what they can do during startup.
Change-Id: I18275f458952a8d790736a9c9559b27bbef97b7b
The remapping from /dev/tty to the real controlling terminal in the
device code was confusing the select code. The latter is now aware
of this case and should handle it properly, at the cost of one extra
field in the filp structure.
There is a nasty, hopefully sufficiently rare case of /dev/tty being
kept open while controlling terminals are changing, that we are still
not handling. Doing so would require more than just a few changes,
but the code should at least detect and cleanly fail on this case.
Test77 now has a basic test set for selecting on /dev/tty.
Change-Id: Iaedea449cdb728d0e66a9de8faacdfd9638dfe92
