Previously, VFS would reopen a character device after a driver crash
if the associated file descriptor was opened with the O_REOPEN flag.
This patch removes support for this feature. The code was complex,
full of uncovered corner cases, and hard to test. Moreover, it did not
actually hide the crash from user applications: they would get an
error code to indicate that something went wrong, and have to decide
based on the nature of the underlying device how to continue.
- remove support for O_REOPEN, and make playwave(1) reopen its device;
- remove support for the DEV_REOPEN protocol message;
- remove all code in VFS related to reopening character devices;
- no longer change VFS filp reference count and FD bitmap upon filp
invalidation; instead, make get_filp* fail all calls on invalidated
FDs except when obtained with the locktype VNODE_OPCL which is used
by close_fd only;
- remove the VFS fproc file descriptor bitmap entirely, returning to
the situation that a FD is in use if its slot points to a filp; use
FILP_CLOSED as single means of marking a filp as invalidated.
Change-Id: I34f6bc69a036b3a8fc667c1f80435ff3af56558f
- block the calling thread on character device close;
- fully separate block and character open/close routines;
- reuse generic open/close code for the cloning case;
- zero all messages to drivers before filling them;
- use appropriate types for major/minor device numbers.
Change-Id: Ia90e6fe5688f212f835c5ee1bfca831cb249cf51
- prefix them with VFS_ as they are going to VFS;
- give these calls normal call numbers;
- give them their own set of message field aliases;
- also make do_mapdriver a regular call.
Change-Id: I2140439f288b06d699a1f65438bd8306509b259e
The B0-B115200 defines are flags, and not the actual speed they
represent.
This fixes an incoherency for B0 handling, and documents why it is
required to call the function again after changing the speed flag.
DFL_BAUD is set to one of the flag, so to translate it to an actual
speed, the function calls itself again, which will always be able to
finish without inducing another recursive call.
Change-Id: I04ebfaefee31a88d05f0b726352d1581a966147b
It is unclear why /dev/log has its own open/close rules, but those
rules conflict with serial console redirection. This does not solve
the root of the problem, but it puts back in place more or less the
same workaround that was already in place before the TTY overhaul.
Change-Id: Ib53abbc28a76c1f2b0befc8448aeed0173bc96a5
- writing to a PTY master side blocks if there is not already a
blocked reader on the slave side, and select now reflects this;
- internally, TTY now uses a test based on "caller != NONE" rather
than "grant != GRANT_INVALID" to identify whether a call is
currently ongoing;
- "offset" fields have been removed as they equal the corresponding
"cum" fields;
- improved variable typing and function naming here and there;
- various other small fixes.
Change-Id: I6b51452888942e864b4e034e8c8490576184a23e
- check each file descriptor's open access mode (filp_mode);
- treat an error returned by a character driver as a select error;
- check all filps in each set before finishing select;
- do not copy back file descriptor sets if an error occurred;
- remove the hardcoded list of supported character major devices,
since all drivers should now be capable of responding properly;
- add tests to test40 and fix its error count aggregation.
Change-Id: I57ef58d3afb82640fc50b59c859ee4b25f02db17
- simplify and repair UDS request handling state machine;
- simplify interface used between internal modules;
- implement missing support for nonblocking I/O;
- fix select implementation;
- clean up global variables.
Change-Id: Ia82c5c6f05cc3f0a498efc9a26de14b1cde6eace
The new API now covers the entire character driver protocol, while
hiding all the message details. It should therefore be used by all
new character drivers. All existing drivers that already made use of
libchardriver have been changed to use the new API.
As one of the most important API changes, support for scatter and
gather transfers has been removed, as several key drivers already
did not support this, and it could be supported at the safecopy
level instead (for a future readv/writev).
Additional changes include:
- respond to block device open requests to avoid hanging VFS threads;
- add support for sef_cancel.
Change-Id: I1bab6c1cb66916c71b87aeb1db54a9bdf171fe6b
Some block drivers do not impose any alignment requirements, and this
patch allows such block drivers to pass the test set. As a side effect,
minimal support for min_write is added, but this part of blocktest is
in need of further improvement.
Change-Id: I9ea81433a6fe1177742020e6a584f876043d7e9a
If a device node is given without path, and opening the node fails
initially, prepend "/dev/" to the node name and try opening again.
This is more in line with NetBSD behavior.
Change-Id: Ib544aec52abe43132510f0e4b173b00fb3dbaab8
The block driver protocol and libblockdriver's bdr_ioctl hook are
changed, as well as the users of this hook. Other parts of the system
are expected to change accordingly eventually, since the ioctl(2)
prototype has been aligned with NetBSD's.
Change-Id: Ide46245b22cfa89ed267a38088fb0ab7696eba92
I/O control requests now come with the endpoint of the user process
that initiated the ioctl(2) call. It is stored in a new BDEV_USER
field, which is an alias for BDEV_FLAGS. The contents of this field
are to be used only in highly specific situations. It should be
preserved (not replaced!) by services that forward IOCTL requests,
and may be set to NONE for service-initiated IOCTL requests.
Change-Id: I68a01b9ce43eca00e61b985a9cf87f55ba683de4
The original R_BIT and W_BIT definitions have nothing to do with the
way these bits are used. Their distinct usage is more apparent when
they have different names.
Change-Id: Ia984457f900078b2e3502ceed565fead4e5bb965
This constant determines the range of valid device_id_t values that
a block driver can return from the bdr_device hook: a value between
0 and (BLOCKDRIVER_MAX_DEVICES - 1) inclusive.
Change-Id: I80fac469e88ac13d4b869007e6f2c2f7569da433
- internal structure rearrangement;
- respond to char device open requests to avoid hanging VFS threads;
- make drivers use designated initializers;
- use devminor_t for all minor device numbers;
- change bdr_other hook to take ipc_status and return nothing;
- fix default geometry computation;
- add support for sef_cancel.
Change-Id: Ia063a136a3ddb2b78de36180feda870605753d70
Previously, reading from or writing to a character device would not
update the file position on the corresponding filp object. Performing
this update correctly is not trivial: during and after the I/O
operation, the filp object must not be locked. Ideally, read/write
requests on a filp that is already involved in a read/write operation,
should be queued. For now, we optimistically update the file position
at the start of the I/O; this works under the assumptions listed in
the corresponding comment.
Change-Id: I172a61781850423709924390ae3df1f2d1f94707
Previously it would use bits of the character driver protocol, which
will change heavily. In the new situation, the BUSC_I2C_xxx requests
use a protocol more in line with the PCI protocol, with the reply code
in m_type.
Change-Id: I51597b3f191078c8178ce17372de123031f7a4c4
Opening and closing the master side of a pseudo terminal without
opening the slave side would result in the pseudo terminal becoming
permanently unavailable. In addition, reopening the slave side
would be possible but not allow for I/O. Finally, attempting to
open an in-use master would wipe its I/O state. These issues have
been resolved.
Change-Id: I9235e3d9aba321803f9280b86b6b5e3646ad5ef3
POSIX states that when interrupted, partially successful pipe
operations should return the partial result rather than EINTR. VFS
previously wouldn't look at the partial result, and not clear it
either, which would result in a panic upon the next pipe operation.
Change-Id: Ia1eb72b4b77394051444e63a1390d49bb315eb04
The main purpose of this patch is to fix handling of unpause calls
from PM while another call is ongoing. The solution to this problem
sparked a full revision of the threading model, consisting of a large
number of related changes:
- all active worker threads are now always associated with a process,
and every process has at most one active thread working for it;
- the process lock is always held by a process's worker thread;
- a process can now have both normal work and postponed PM work
associated to it;
- timer expiry and non-postponed PM work is done from the main thread;
- filp garbage collection is done from a thread associated with VFS;
- reboot calls from PM are now done from a thread associated with PM;
- the DS events handler is protected from starting multiple threads;
- support for a system worker thread has been removed;
- the deadlock recovery thread has been replaced by a parameter to the
worker_start() function; the number of worker threads has
consequently been increased by one;
- saving and restoring of global but per-thread variables is now
centralized in worker_suspend() and worker_resume(); err_code is now
saved and restored in all cases;
- the concept of jobs has been removed, and job_m_in now points to a
message stored in the worker thread structure instead;
- the PM lock has been removed;
- the separate exec lock has been replaced by a lock on the VM
process, which was already being locked for exec calls anyway;
- PM_UNPAUSE is now processed as a postponed PM request, from a thread
associated with the target process;
- the FP_DROP_WORK flag has been removed, since it is no longer more
than just an optimization and only applied to processes operating on
a pipe when getting killed;
- assignment to "fp" now takes place only when obtaining new work in
the main thread or a worker thread, when resuming execution of a
thread, and in the special case of exiting processes during reboot;
- there are no longer special cases where the yield() call is used to
force a thread to run.
Change-Id: I7a97b9b95c2450454a9b5318dfa0e6150d4e6858
The T_DUMPCORE implementation was not only broken - it would currently
produce a coredump of the tracer process rather than the traced
process - but also deeply flawed, and fixing it would require serious
alteration of PM's internal state machine. It should be possible to
implement the same functionality in userland, and that is now the
suggested way forward. For now, also remove the (identical) utilities
using T_DUMPCORE: dumpcore(1) and gcore(1).
Change-Id: I1d51be19c739362b8a5833de949b76382a1edbcc
Previously, processing of some replies coming from character drivers
could block on locks, and therefore, such processing was done from
threads that were associated to the character driver process. The
hidden consequence of this was that if all threads were in use, VFS
could drop replies coming from the driver. This patch returns VFS to
a situation where the replies from character drivers are processed
instantly from the main thread, by removing the situations that may
cause VFS to block while handling those replies.
- change the locking model for select, so that it will never block
on any processing that happens after the select call has been set
up, in particular processing of character driver select replies;
- clearly mark all select routines that may never block;
- protect against race conditions in do_select as result of the
locking that still does happen there (as is required for pipes);
- also handle select timers from the main thread;
- move processing of character driver replies into device.c.
Change-Id: I4dc8e69f265cbd178de0fbf321d35f58f067cc57
These days, DEV_OPEN calls to character drivers block the calling
thread until completion or failure, and thus never return SUSPEND to
the caller. The same already applied to BDEV_OPEN calls to block
drivers. It has thus become impossible for a process to enter a state
of being blocked on a device open call.
There is currently no support for restarting device open calls to
restarted character drivers. This support was present in the _DOPEN
logic, but was already no longer triggering. In the future, this case
should be handled by the thread performing the open request.
Change-Id: I6cc1e7b4c9ed116c6ce160b315e6e060124dce00
Not doing so caused PFS to commit protocol violations by relying on
stale information when sending replies. This stale information always
happened to be correct, which is why the problem went unnoticed.
Change-Id: Ia42ca670718d6e731193cd2c34a3ff455f8a94d3
- change all sync char drivers into async drivers;
- retire support for the sync protocol in libchardev;
- remove async dev style, as this is now the default;
- remove dev_status from VFS;
- clean up now-unused protocol messages.
Change-Id: I6aacff712292f6b29f2ccd51bc1e7d7003723e87
The async char protocol already has this, so this patch closes the
gap between the two protocols a bit. Support for this flag has been
added to all sync char drivers that support CANCEL at all.
The LOG driver was already using the asynchronous protocol, but it
did not support the nonblocking transfer flag. This has been fixed
as well.
Change-Id: Ia55432c9f102765b59ad3feb45a8bd47a782c93f
As with w_task, this ensures that the field remains cleared if it is
not used. Without this, worker_stop could mistakenly identify a thread
as talking to a device driver rather than a (crashed) file server.
Change-Id: I7d3ebed3efc3cd4f5c891f61c67a6463109b6376
It was always set, but not always cleared, when talking to asynchronous
drivers. This could cause erratic behavior upon a driver crash.
Normally, a worker thread's w_task field is set when it's about to
communicate with a driver or FS. Then upon receiving a reply we can
do sanity checks (that the thread we want to wake up was actually
waiting for a reply). Also, when a driver/FS crashes, we can identify
which worker threads were talking to the crashed endpoint and handle
the error gracefully.
Asynchronous drivers are a bit special, though. In most cases, the
sender of the request is not interested in the reply (the sender was
suspended and only wants to know whether the request was successfully
caried out or not). However, the open request is special, as the reply
carries information needed by the sender. This is the only request
where a worker thread actually yields and waits for the result. This is
also the only case where we're interested in setting w_task for
asynchronous drivers.
Change-Id: Ia1ce2747937df376122b5e13b6a069de27fcc379
* Removed startup code patches in lib/csu regarding kernel to userland
ABI.
* Aligned stack layout on NetBSD stack layout.
* Generate valid stack pointers instead of offsets by taking into account
_minix_kerninfo->kinfo->user_sp.
* Refactored stack generation, by moving part of execve in two
functions {minix_stack_params(), minix_stack_fill()} and using them
in execve(), rs and vm.
* Changed load offset of rtld (ld.so) to:
execi.args.stack_high - execi.args.stack_size - 0xa00000
which is 10MB below the main executable stack.
Change-Id: I839daf3de43321cded44105634102d419cb36cec
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
