The symptom was that sometimes file systems would occasionally not appear
in output from 'df' or 'mount' if the system was busy. Resolution:
- Make mount locks work somewhat like vm_map locks.
- vfs_trybusy() now only fails if the mount is gone, or if someone is
unmounting the file system. Simple contention on mnt_lock doesn't
cause it to fail.
- vfs_busy() will wait even if the file system is being unmounted.
we no longer need to guard against access from hardware interrupt handlers.
Additionally, if cloning a process with CLONE_SIGHAND, arrange to have the
child process share the parent's lock so that signal state may be kept in
sync. Partially addresses PR kern/37437.
proclist_mutex and proclist_lock into a single adaptive mutex (proc_lock).
Implications:
- Inspecting process state requires thread context, so signals can no longer
be sent from a hardware interrupt handler. Signal activity must be
deferred to a soft interrupt or kthread.
- As the proc state locking is simplified, it's now safe to take exit()
and wait() out from under kernel_lock.
- The system spends less time at IPL_SCHED, and there is less lock activity.
- Do reference counting for 'struct mount'. Each vnode associated with a
mount takes a reference, and in turn the mount takes a reference to the
vfsops.
- Now that mounts are reference counted, replace the overcomplicated mount
locking inherited from 4.4BSD with a recursable rwlock.
Introduce a per-FS rename lock and new vfsops to manipulate it.
Get this lock while renaming. Also add another relookup() in do_sys_rename,
which is a hack to kludge around some of the worst deficiencies of
ufs_rename.
reviewed-by: pooka (and an earlier rev by ad)
posted on tech-kern with no objections.
- Add a KAUTH_PROCESS_SCHEDULER action, to handle scheduler related
requests, and add specific requests for set/get scheduler policy and
set/get scheduler parameters.
- Add a KAUTH_PROCESS_KEVENT_FILTER action, to handle kevent(2) related
requests.
- Add a KAUTH_DEVICE_TTY_STI action to handle requests to TIOCSTI.
- Add requests for the KAUTH_PROCESS_CANSEE action, indicating what
process information is being looked at (entry itself, args, env,
open files).
- Add requests for the KAUTH_PROCESS_RLIMIT action indicating set/get.
- Add requests for the KAUTH_PROCESS_CORENAME action indicating set/get.
- Make bsd44 secmodel code handle the newly added rqeuests appropriately.
All of the above make it possible to issue finer-grained kauth(9) calls in
many places, removing some KAUTH_GENERIC_ISSUSER requests.
- Remove the "CAN" from KAUTH_PROCESS_CAN{KTRACE,PROCFS,PTRACE,SIGNAL}.
Discussed with christos@ and yamt@.
The general trend is to remove it from all kernel interfaces and
this is a start. In case the calling lwp is desired, curlwp should
be used.
quick consensus on tech-kern
knew what it was supposed to be used for and wrstuden gave a go-ahead
* while rototilling, convert file systems which went easily to
use VFS_PROTOS() instead of manually prototyping the methods
instead of the result from getcwd(). The works around locking
panics caused by namei calling VOP_READLINK while holding on to a
directory lock and getcwd() trying to acquire that lock. The real
fix would be to get rid of getcwd() calls within VOPs (not locking
safe), but that's not a viable option in the netbsd-4 timeframe.
Suggestion for workaround from David Holland.
fs code is a kernel buffer, pass though the length of the buffer as well.
Since the length of the userspace buffer isn'it (yet) passed through the mount
system call, add a field to the vfsops structure containing the default length.
Split sys_mount() for calls from compat code.
Ride one of the recent kernel version changes - old fs LKMs will load, but
sys_mount() will reject any attempt to use them.
vmspace information fails.
Return the nice value properly to userland via the /proc/<pid>/stat entry.
Use vm sizes from vmspace, rather than rusage structs, for the same
reasons as mentioned previously - see the comment in
kvm_proc.c::kvm_getproc2() about rusage values and zombie processes.
+ in /proc/<pid>/statm emulation, use the memory values from vmspace,
rather than struct rusage, since the rusage values appear to be 0 for
all processes except zombies. cf dsl's comment in
kvm_proc.c::kvm_getproc2()
+ in /proc/<pid>/stat, instead of returning the tv_sec value, return the
number of ticks we've had (roughly equivalent to the Linux jiffies).
Calculate these values from the tv_usec values.
Also:
+ enclose CPU_INFO_ITERATOR and CPU_INFO_FOREACH usage in #ifdef
MULTIPROCESSOR, at the request of Nick Hudson
Together, these changes allow htop to work on NetBSD.
/proc/stat
/proc/loadavg and
/proc/<pid>/statm.
These are only present when -o linux is specified as a mount option
to procfs.
Factor out some common code so that it can be used by a number of
functions.
XXX The values returned in the statm emulation need to be verified.
write the whole map in one shot so that we don't have to deal with the
map changing under us. Fixes the linux emulated jdk-1.6 where it was
losing the last map entry and could not find the stack on startup.
- Drop the target's vm_map lock before calling uiomove(). We could
deadlock if inspecting /proc/curproc/map.
- If the vm_map might have changed, restart the operation, but give
up after 250 retries if the map keeps changing. XXX This is not
ideal.
P_*/L_* naming convention, and rename the in-kernel flags to avoid
conflict. (P_ -> PK_, L_ -> LW_ ). Add back the (now unused) LSDEAD
constant.
Restores source compatibility with pre-newlock2 tools like ps or top.
Reviewed by Andrew Doran.
process we're trying to get information about through procfs, not
the caller of lookup.
fixes 'ls -l /proc/*/file' panic, which would occur when trying to
lookup "file" for a kernel thread, which doesn't have p->p_textvp.
ad