closely what function is really doing. Update all existing consumers
to use the new name.
Introduce a new vfs_stdsync function, which iterates over mount
point's vnodes and call FSYNC on each one of them in turn.
Make nwfs and smbfs use this new function instead of rolling their
own identical sync implementations.
Reviewed by: jeff
a parameter instead of using the level of a given witness. When
recursing, pass an indent level of indent + 1.
- Make use of the information witness_levelall() provides in
witness_display_list() to use an O(n) algorithm instead of an O(n^2)
algo to decide which witnesses to display hierarchies from. Basically,
we only display a hierarchy for witnesses with a level of 0.
- Add a new per-witness flag that is reset at the start of
witness_display() for all witness's and is set the first time a witness
is displayed in witness_displaydescendants(). If a witness is
encountered more than once in the lock order tree (which happens often),
witness_displaydescendants() marks the later occurrences with the string
"(already displayed)" and doesn't display the subtree under that
witness. This avoids duplicating large amounts of the lock order tree
in the 'show witness' output in DDB.
All these changes serve to make 'show witness' a lot more readable and
useful than it was previously.
adds a witness to the child list of a parent witness. rebalancetree()
runs through the entire tree removing direct descendants of witnesses
who already have said child witness as an indirect descendant through
another direct descendant. itismychild() now calls insertchild()
followed by rebalancetree() and no longer needs the evil hack of
having static recursed variable.
- Add a function reparentchildren() that adds all the direct descendants
of one witness as direct descendants of another witness.
- Change the return value of itismychild() and similar functions so that
they return 0 in the case of failure due to lack of resources instead
of 1. This makes the return value more intuitive.
- Check the return value of itismychild() when defining the static lock
order in witness_initialize().
- Don't try to setup a lock instance in witness_lock() if itismychild()
fails. Witness is hosed anyways so no need to do any more witness
related activity at that point. It also makes the code flow easier to
understand.
- Add a new depart() function as the opposite of enroll(). When the
reference count of a witness drops to 0 in witness_destroy(), this
function is called on that witness. First, it runs through the
lock order tree using reparentchildren() to reparent direct descendants
of the departing witness to each of the witness' parents in the tree.
Next, it releases it's own child list and other associated resources.
Finally it calls rebalanacetree() to rebalance the lock order tree.
- Sort function prototypes into something closer to alphabetical order.
As a result of these changes, there should no longer be 'dead' witnesses
in the order tree, and repeatedly loading and unloading a module should no
longer exhaust witness of its internal resources.
Inspired by: gallatin
recursing on a lock instead of before. This fixes a bug where WITNESS
could get a little confused if you did an sx_tryslock() on a sx lock that
you already had an slock on. WITNESS would still function correctly but
it could result in weirdness in the output of 'show locks'. This also
makes it possible for mtx_trylock() to recurse on a lock.
used popped into my head during my morning commute a few weeks ago, but
it is also very similar (though a bit simpler) to a patch that mini@
developed a while ago. Basically, each eventhandler list has a mutex and
a run count. During an eventhandler invocation, the mutex is held while
we traverse the list but is dropped while we execute actual handlers. Also,
a runcount counter is incremented at the start of an invocation and
decremented at the end of an invocation. Adding to the list is not a big
deal since the reference of a thread currently executing the handlers
remains valid across an add operation. Whether or not new handlers are
executed by threads currently executing the handlers for a given list is
indeterminate however. The harder case is when a handler is removed from
the list. If the runcount is zero, the handler is simply removed from the
list directly. If the runcount is not zero, then another thread is
currently executing the handlers of this list, so the priority of this
handler is set to a magic value (currently -1) to mark it as dead. Dead
handlers are not executed during an invocation. If the runcount is zero
after it is decremented at the end of an invocation, then a new
eventhandler_prune_list() function is called to remove dead handlers from
the list.
Additional minor notes:
- All the common parts of EVENTHANDLER_INVOKE() and
EVENTHANDLER_FAST_INVOKE() have been merged into a common
_EVENTHANDLER_INVOKE() macro to reduce duplication and ease maintenance.
- KTR logging for eventhandlers is now available via the KTR_EVH mask.
- The global eventhander_mutex is no longer recursive.
Tested by: scottl (SMP i386)
monitors the entropy data harvested by crypto drivers to verify it complies
with FIPS 140-2. If data fails any test then the driver discards it and
commences continuous testing of harvested data until it is deemed ok.
Results are collected in a statistics block and, optionally, reported on
the console. In normal use the overhead associated with this driver is
not noticeable.
Note that drivers must (currently) be compiled specially to enable use.
Obtained from: original code by Jason L. Wright
attach routine, calling WIUNLOCK in the error case of one of the ifs
for that routine is now bogus. This should have been removed when the
WILOCK() was removed, but wasn't.
Submitted by: "Harti Brandt" <brandt@fokus.fraunhofer.de>
it is expected that they will not be enabled at the time that it
is called. This is reported to work around a problem in RELENG_4
where the kernel panics on boot if FAST_IPSEC and crypto support
are enabled.
Tested by: Scott Johnson <scottj@insane.com>
- Issue the io that we will later block on prior to doing cluster read ahead
so that it is more likely to be ready when we block.
- Loop issuing clustered reads until we've exhausted the seq count supplied
by the file system.
- Use a sysctl tunable "vfs.read_max" to determine the maximum number of
blocks that we'll read ahead.
kern_sig.c 1.215
kern_thread.c 1.103
kern_exit.c 1.199
proc.h 1.302
Orignal code would suspend an already suspended thread,
if user presses ^Z while a threaded program is running. Also
there is a race between job control and thread_exit(), the
new code tests job control requesting before thread exits,
in wait() syscall, be sure to check child process is fully
stopped, this avoids a later SIGCHILD and returns STOPPED
status twice for a threaded child proc. A thread_stopped()
function is added for common code in several places.
use the underlying AsahiOptical USB chip and thus this quirk may need to
be generalized in the future.
PR: kern/46369
Submitted by: Tim Vanderhoek <vanderh@ecf.utoronto.ca>
MFC After: 3 days
I had commented the #ifdef INVARIANTS checks out to make sure I ran this
code in all kernels and forgot to comment the #ifdefs back in before I
committed.
Spotted by: bmilekic
[1] PHCC = Pointy Hat Correction Commit
