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102 commits

Author SHA1 Message Date
Cristiano Giuffrida
1f5841c8ed Basic System Event Framework (SEF) with ping and live update.
SYSLIB CHANGES:
- SEF must be used by every system process and is thereby part of the system
library.
- The framework provides a receive() interface (sef_receive) for system
processes to automatically catch known system even messages and process them.
- SEF provides a default behavior for each type of system event, but allows
system processes to register callbacks to override the default behavior.
- Custom (local to the process) or predefined (provided by SEF) callback
implementations can be registered to SEF.
- SEF currently includes support for 2 types of system events:
  1. SEF Ping. The event occurs every time RS sends a ping to figure out
  whether a system process is still alive. The default callback implementation
  provided by SEF is to notify RS back to let it know the process is alive
  and kicking.
  2. SEF Live update. The event occurs every time RS sends a prepare to update
  message to let a system process know an update is available and to prepare
  for it. The live update support is very basic for now. SEF only deals with
  verifying if the prepare state can be supported by the process, dumping the
  state for debugging purposes, and providing an event-driven programming
  model to the process to react to state changes check-in when ready to update.
- SEF should be extended in the future to integrate support for more types of
system events. Ideally, all the cross-cutting concerns should be integrated into
SEF to avoid duplicating code and ease extensibility. Examples include:
  * PM notify messages primarily used at shutdown.
  * SYSTEM notify messages primarily used for signals.
  * CLOCK notify messages used for system alarms.
  * Debug messages. IS could still be in charge of fkey handling but would
  forward the debug message to the target process (e.g. PM, if the user
  requested debug information about PM). SEF would then catch the message and
  do nothing unless the process has registered an appropriate callback to
  deal with the event. This simplifies the programming model to print debug
  information, avoids duplicating code, and reduces the effort to print
  debug information.

SYSTEM PROCESSES CHANGES:
- Every system process registers SEF callbacks it needs to override the default
system behavior and calls sef_startup() right after being started.
- sef_startup() does almost nothing now, but will be extended in the future to
support callbacks of its own to let RS control and synchronize with every
system process at initialization time.
- Every system process calls sef_receive() now rather than receive() directly,
to let SEF handle predefined system events.

RS CHANGES:
- RS supports a basic single-component live update protocol now, as follows:
  * When an update command is issued (via "service update *"), RS notifies the
  target system process to prepare for a specific update state.
  * If the process doesn't respond back in time, the update is aborted.
  * When the process responds back, RS kills it and marks it for refreshing.
  * The process is then automatically restarted as for a buggy process and can
  start running again.
  * Live update is currently prototyped as a controlled failure.
2009-12-21 14:12:21 +00:00
Thomas Veerman
6aa43dc9e4 Fix typo and a bug causing vnode references to become too low. 2009-12-21 09:36:34 +00:00
Thomas Veerman
958b25be50 - Introduce support for sticky bit.
- Revise VFS-FS protocol and update VFS/MFS/ISOFS accordingly.
- Clean up MFS by removing old, dead code (backwards compatibility is broken by
  the new VFS-FS protocol, anyway) and rewrite other parts. Also, make sure all
  functions have proper banners and prototypes.
- VFS should always provide a (syntactically) valid path to the FS; no need for
  the FS to do sanity checks when leaving/entering mount points.
- Fix several bugs in MFS:
  - Several path lookup bugs in MFS.
  - A link can be too big for the path buffer.
  - A mountpoint can become inaccessible when the creation of a new inode
    fails, because the inode already exists and is a mountpoint.
- Introduce support for supplemental groups.
- Add test 46 to test supplemental group functionality (and removed obsolete
  suppl. tests from test 2).
- Clean up VFS (not everything is done yet).
- ISOFS now opens device read-only. This makes the -r flag in the mount command
  unnecessary (but will still report to be mounted read-write).
- Introduce PipeFS. PipeFS is a new FS that handles all anonymous and
  named pipes. However, named pipes still reside on the (M)FS, as they are part
  of the file system on disk. To make this work VFS now has a concept of
  'mapped' inodes, which causes read, write, truncate and stat requests to be
  redirected to the mapped FS, and all other requests to the original FS.
2009-12-20 20:27:14 +00:00
David van Moolenbroek
be2087ecf9 Filter driver by Wu Bingzheng et al 2009-12-02 10:08:58 +00:00
David van Moolenbroek
f89388c241 Kernel, servers: remove unused proto.h definitions 2009-10-31 14:11:50 +00:00
David van Moolenbroek
6c4197f77e PM, VFS: remove unused param.h definitions 2009-10-29 13:29:04 +00:00
Ben Gras
c373473f24 add prototype for wait_for() to fix compiler warning. 2009-10-05 16:43:02 +00:00
David van Moolenbroek
b423d7b477 Merge of David's ptrace branch. Summary:
o Support for ptrace T_ATTACH/T_DETACH and T_SYSCALL
o PM signal handling logic should now work properly, even with debuggers
  being present
o Asynchronous PM/VFS protocol, full IPC support for senda(), and
  AMF_NOREPLY senda() flag

DETAILS

Process stop and delay call handling of PM:
o Added sys_runctl() kernel call with sys_stop() and sys_resume()
  aliases, for PM to stop and resume a process
o Added exception for sending/syscall-traced processes to sys_runctl(),
  and matching SIGKREADY pseudo-signal to PM
o Fixed PM signal logic to deal with requests from a process after
  stopping it (so-called "delay calls"), using the SIGKREADY facility
o Fixed various PM panics due to race conditions with delay calls versus
  VFS calls
o Removed special PRIO_STOP priority value
o Added SYS_LOCK RTS kernel flag, to stop an individual process from
  running while modifying its process structure

Signal and debugger handling in PM:
o Fixed debugger signals being dropped if a second signal arrives when
  the debugger has not retrieved the first one
o Fixed debugger signals being sent to the debugger more than once
o Fixed debugger signals unpausing process in VFS; removed PM_UNPAUSE_TR
  protocol message
o Detached debugger signals from general signal logic and from being
  blocked on VFS calls, meaning that even VFS can now be traced
o Fixed debugger being unable to receive more than one pending signal in
  one process stop
o Fixed signal delivery being delayed needlessly when multiple signals
  are pending
o Fixed wait test for tracer, which was returning for children that were
  not waited for
o Removed second parallel pending call from PM to VFS for any process
o Fixed process becoming runnable between exec() and debugger trap
o Added support for notifying the debugger before the parent when a
  debugged child exits
o Fixed debugger death causing child to remain stopped forever
o Fixed consistently incorrect use of _NSIG

Extensions to ptrace():
o Added T_ATTACH and T_DETACH ptrace request, to attach and detach a
  debugger to and from a process
o Added T_SYSCALL ptrace request, to trace system calls
o Added T_SETOPT ptrace request, to set trace options
o Added TO_TRACEFORK trace option, to attach automatically to children
  of a traced process
o Added TO_ALTEXEC trace option, to send SIGSTOP instead of SIGTRAP upon
  a successful exec() of the tracee
o Extended T_GETUSER ptrace support to allow retrieving a process's priv
  structure
o Removed T_STOP ptrace request again, as it does not help implementing
  debuggers properly
o Added MINIX3-specific ptrace test (test42)
o Added proper manual page for ptrace(2)

Asynchronous PM/VFS interface:
o Fixed asynchronous messages not being checked when receive() is called
  with an endpoint other than ANY
o Added AMF_NOREPLY senda() flag, preventing such messages from
  satisfying the receive part of a sendrec()
o Added asynsend3() that takes optional flags; asynsend() is now a
  #define passing in 0 as third parameter
o Made PM/VFS protocol asynchronous; reintroduced tell_fs()
o Made PM_BASE request/reply number range unique
o Hacked in a horrible temporary workaround into RS to deal with newly
  revealed RS-PM-VFS race condition triangle until VFS is asynchronous

System signal handling:
o Fixed shutdown logic of device drivers; removed old SIGKSTOP signal
o Removed is-superuser check from PM's do_procstat() (aka getsigset())
o Added sigset macros to allow system processes to deal with the full
  signal set, rather than just the POSIX subset

Miscellaneous PM fixes:
o Split do_getset into do_get and do_set, merging common code and making
  structure clearer
o Fixed setpriority() being able to put to sleep processes using an
  invalid parameter, or revive zombie processes
o Made find_proc() global; removed obsolete proc_from_pid()
o Cleanup here and there

Also included:
o Fixed false-positive boot order kernel warning
o Removed last traces of old NOTIFY_FROM code

THINGS OF POSSIBLE INTEREST

o It should now be possible to run PM at any priority, even lower than
  user processes
o No assumptions are made about communication speed between PM and VFS,
  although communication must be FIFO
o A debugger will now receive incoming debuggee signals at kill time
  only; the process may not yet be fully stopped
o A first step has been made towards making the SYSTEM task preemptible
2009-09-30 09:57:22 +00:00
Ben Gras
8d9aa1fe4f throw out exec debugging message. 2009-09-30 08:36:13 +00:00
Tomas Hruby
97fe6a4ba5 Broken pipes fix
- fix for the broken partial pipes r/w operations
2009-09-24 16:03:25 +00:00
Tomas Hruby
f53377ed67 Removed the broken PROC_EVENT and SYN_ALARM from VFS 2009-09-22 22:11:20 +00:00
Tomas Hruby
8590ac260d Removed dependency of vfs on NR_TASKS macro
- all macros in consts.h that depend on NR_TASKS replaced by a FP_BLOCKED_ON_*

- fp_suspended removed and replaced by fp_blocked_on. Testing whether a process
  is supended is qeual to testing whether fp_blocked_on is FP_BLOCKED_ON_NONE or
  not

- fp_task is valid only if fp_blocked_on == FP_BLOCKED_ON_OTHER

- no need of special values that do not colide with valid and special endpoints
  since they are not used as endpoints anymore

- suspend only takes FP_BLOCKED_ON_* values not endpoints anymore

- suspend(task) replaced by wait_for(task) which sets fp_task so we remember who
  are we waiting for and suspend sets fp_blocked_on to FP_BLOCKED_ON_OTHER to
  signal that we are waiting for some other process

- some functions should take endpoint_t instead of int, fixed
2009-09-22 21:48:26 +00:00
Ben Gras
f5459e38db - some exec debugging prints when errors happen
- lookup mounted_on check to avoid NULL dereference
 - some errors in exec() shouldn't be fatal
2009-09-21 14:49:26 +00:00
David van Moolenbroek
42f0bf7dda VFS: fetch_name() buffer underflow (reported by John Peace, bug #305) 2009-08-29 08:22:50 +00:00
Tomas Hruby
f3e0c5c381 VFS quits gracefully if mount fails and mounted_on remains uninitialized 2009-08-18 13:30:05 +00:00
David van Moolenbroek
d82e260a90 Support for setitimer(ITIMER_REAL). 2009-08-15 16:09:32 +00:00
Thomas Veerman
ce916bcb91 Fixed a minor select bug:
- When one does a select on a file descriptor that is meaningless for that particular file type, select shall indicate that the file descriptor is ready for that particular operation and that the file descriptor has no exceptional condition pending.
2009-07-14 09:39:05 +00:00
David van Moolenbroek
1a9e07b0e5 PM: fix ptrace(T_EXIT) 'exit_proc: not idle' race condition. 2009-07-11 13:22:56 +00:00
David van Moolenbroek
9797d17d54 move symlink type check for readlink() into VFS, and return the right POSIX error 2009-05-20 09:46:06 +00:00
David van Moolenbroek
50b77e3529 VFS consistency: use I_PIPE/NO_PIPE when checking v_pipe 2009-05-19 14:34:44 +00:00
David van Moolenbroek
f76d75a5ec Various VFS and MFS fixes to improve correctness, consistency and
POSIX compliance.

VFS changes:
* truncate() on a file system mounted read-only no longer panics MFS.
* ftruncate() and fcntl(F_FREESP) now check for write permission on
  the file descriptor instead of the file, write().
* utime(), chown() and fchown() now check for file system read-only
  status.

MFS changes:
* link() and rename() no longer return the internal EENTERMOUNT and
  ELEAVEMOUNT errors to the application as part of a check on the
  source path.
* rename() now treats EENTERMOUNT from the destination path check as
  an error, preventing file system corruption from renaming a normal
  directory to an existing mountpoint directory.
* mountpoints (mounted-on dirs) are hidden better during lookups:
  - if a lookup starts from a mountpoint, the first component has to
    be ".." (anything else being a VFS-FS protocol violation).
  - in that case, the permissions of the mountpoint are not checked.
  - in all other cases, visiting a mountpoint always results in
    EENTERMOUNT.
* a lookup on ".." from a mount root or chroot(2) root no longer
  succeeds if the caller does not have search permission on that
  directory.
* POSIX: getdents() now updates directory access times.
* POSIX: readlink() now returns partial results instead of ERANGE.

Miscellaneous changes:
* semaphore file handling bug (leading to hangs) fixed in test 32.

The VFS changes should now put the burden of checking for read-only
status of file systems entirely on VFS, and limit the access
permission checks that file systems have to perform, to checking
search permission on directories during lookups. From this point on,
any deviation from that spceification should be considered a bug.
Note that for legacy reasons, the root partition is assumed to be
mounted read-write.
2009-05-18 11:27:12 +00:00
Ben Gras
7c88767f75 remove debug msg 2009-05-11 11:57:20 +00:00
David van Moolenbroek
0ac1aaccca Limited support for nested FS->VFS requests during VFS->FS call.
- Changed VFS-FS protocol to only store OK or negative error code in
  m_type field of reply messages.
- Changed VFS to treat nonzero positive replies from FS as requests.
- Added backwards compatibility to VFS and MFS.
No protection of global data structures is provided in VFS, so many
VFS calls cannot be made safely by FS servers during many FS calls.
Use with caution (or, preferably, not at all).
2009-05-11 10:02:28 +00:00
David van Moolenbroek
e08b38a5c4 regression fix: vfs lookup passes incorrect chroot information after crossing mountpoints 2009-05-09 17:53:22 +00:00
David van Moolenbroek
293be6b80b quick cleanup of old mfs cruft from vfs 2009-05-08 14:12:41 +00:00
Ben Gras
dc1238b7b9 make unpause() decrease susp_count, as it shouldn't be decreased
if the process was REVIVING. (susp_count doesn't count those
 processes.) this together with dev_io SELECT suspend side effect
 for asynch. character devices solves the hanging pipe bug. or
 at last vastly improves it.

 added sanity checks, turned off by default.

 made the {NOT_,}{SUSPENDING,REVIVING} constants weirder to
 help sanity checking.
2009-05-08 13:56:41 +00:00
David van Moolenbroek
113b1ec5f3 remove unused global variable from vfs 2009-05-08 13:54:01 +00:00
Ben Gras
ece26e2731 don't suspend the process as a side-effect if
device returns SUSPEND if it's select; select already
does this.
2009-05-08 13:50:29 +00:00
Ben Gras
746e138036 turn off scary looking debug messages. 2009-05-07 09:57:43 +00:00
Ben Gras
fd7ef243e4 cleanup of vfs shutdown logic; makes clean unmounts easier (but
needs checking if fp_wd or fp_rd is NULL before use)
2009-04-29 16:59:18 +00:00
Ben Gras
73ee8b8b99 don't make susp_count negative. 2009-04-02 11:44:26 +00:00
Ben Gras
3bb80322d9 suppress more mostly-harmless messages. 2009-03-26 16:11:27 +00:00
Ben Gras
2d1c884e35 suppress these noisy, alarming messages. 2009-03-26 15:56:08 +00:00
Ben Gras
8af5f877bc 2009-03-04 17:44:34 +00:00
Ben Gras
3f6e061948 fix error check 2009-03-04 17:38:27 +00:00
Ben Gras
570b9cd753 Checking wrong inode pointer for refcount in mount (!) 2009-02-17 09:50:02 +00:00
Ben Gras
3cc092ff06 . new kernel call sysctl for generic unprivileged system operations;
now used for printing diagnostic messages through the kernel message
   buffer. this lets processes print diagnostics without sending messages
   to tty and log directly, simplifying the message protocol a lot and
   reducing difficulties with deadlocks and other situations in which
   diagnostics are blackholed (e.g. grants don't work). this makes
   DIAGNOSTICS(_S), ASYN_DIAGNOSTICS and DIAG_REPL obsolete, although tty
   and log still accept the codes for 'old' binaries. This also simplifies
   diagnostics in several servers and drivers - only tty needs its own
   kputc() now.
 . simplifications in vfs, and some effort to get the vnode references
   right (consistent) even during shutdown. m_mounted_on is now NULL
   for root filesystems (!) (the original and new root), a less awkward
   special case than 'm_mounted_on == m_root_node'. root now has exactly
   one reference, to root, if no files are open, just like all other
   filesystems. m_driver_e is unused.
2009-01-26 17:43:59 +00:00
Ben Gras
4984a86f32 don't hang on disappearing filesystem. 2009-01-26 13:02:41 +00:00
Ben Gras
86e7e4828e sanity check function 2009-01-20 13:43:18 +00:00
Ben Gras
45ec30f6af mostly harmless sanity checks. 2009-01-20 13:43:00 +00:00
Ben Gras
d2757d4b73 debug buffer slightly usabler. 2008-12-19 15:19:42 +00:00
Ben Gras
834d9d34e8 Initialize deferred field. This seems to fix a hanging select() bug. 2008-12-17 14:20:08 +00:00
Ben Gras
34d5401ed4 put put_vnode() back where it belongs! 2008-12-16 16:11:24 +00:00
Ben Gras
ccf70aa989 system_hz replaces HZ 2008-12-11 14:48:05 +00:00
Ben Gras
7d674f4b8e no more HZ; less debugging statements 2008-12-11 14:47:48 +00:00
Ben Gras
b9a0d46ea9 debug out 2008-12-11 14:46:46 +00:00
Ben Gras
3287b7f7d8 don't hang old binaries 2008-12-11 14:45:49 +00:00
Ben Gras
5e1bb6eb63 added some code to debug why filesystems won't unmount 2008-12-11 14:45:31 +00:00
Ben Gras
c078ec0331 Basic VM and other minor improvements.
Not complete, probably not fully debugged or optimized.
2008-11-19 12:26:10 +00:00
Philip Homburg
f82a1c4df7 Fixed include files. 2008-02-25 14:35:54 +00:00