in FreeBSD 7 that has not been used since. It contains a number
of unresolved bugs including an inverted bcopy() and incorrect
handling of read-only mbufs using internal storage. Removing this
unused code is substantially essier than fixing it in order to
update it to the coming mbuf world order -- but it can always be
restored from revision history if it turns out to prove useful for
future work.
Pointed out by: jmallett
Sponsored by: EMC / Isilon Storage Division
by reinitializing the 'freestate' pointer after freeing the memory.
Obtained from: HardenedBSD (71fab80c5dd3034b71a29a61064625018671bbeb)
PR: 194525
Submitted by: Oliver Pinter <oliver.pinter@hardenedbsd.org>
MFC after: 2 weeks
decade: m_pulldown() is willing to consider ordinary mbufs writable.
Retain another, related, and also outdated comment, but with a caveat
that it is partially stale. Do not, for now, address the problem that
it raises (that only EXT_CLUSTER external storage is considered
writable, regardless of the results of M_WRITABLE() on the mbuf).
MFC after: 3 days
Sponsored by: EMC / Isilon Storage Division
EOPNOTSUPP. The current behavior can mask real quiesce errors since
devclass_quiesce_driver() stops iterating over drivers as soon as it
gets an error (incluiding EOPNOTSUPP), but the caller it returns the
error to explicitly ignores EOPNOTSUPP.
Reviewed by: imp
kernel via the global cpuset_domain[] array. To export these to userland,
add a CPU_WHICH_DOMAIN level that can be used to fetch the mask for a
specific domain. Add a -d flag to cpuset(1) that can be used to fetch
the mask for a given domain.
Differential Revision: https://reviews.freebsd.org/D1232
Submitted by: jeff (kernel bits)
Reviewed by: adrian, jeff
with calls to the centralised macros, reducing direct use of MLEN and
MHLEN.
Differential Revision: https://reviews.freebsd.org/D1444
Reviewed by: bz
Sponsored by: EMC / Isilon Storage Division
code in sys/kern/kern_dump.c. Most dumpsys() implementations are nearly
identical and simply redefine a number of constants and helper subroutines;
a generic implementation will make it easier to implement features around
kernel core dumps. This change does not alter any minidump code and should
have no functional impact.
PR: 193873
Differential Revision: https://reviews.freebsd.org/D904
Submitted by: Conrad Meyer <conrad.meyer@isilon.com>
Reviewed by: jhibbits (earlier version)
Sponsored by: EMC / Isilon Storage Division
may perform a blocking memory allocation, which is unsafe when holding a
mutex.
Differential Revision: https://reviews.freebsd.org/D1443
Reviewed by: rwatson
MFC after: 1 week
Sponsored by: EMC / Isilon Storage Division
may also halt in C2 and not just C3 (it seems that in some cases the BIOS
advertises its C3 state as a C2 state in _CST). Just play it safe and
disable both C2 and C3 states if a user forces the use of the TSC as the
timecounter on such CPUs.
PR: 192316
Differential Revision: https://reviews.freebsd.org/D1441
No objection from: jkim
MFC after: 1 week
the knowledge of mbuf layout, and in particular constants such as M_EXT,
MLEN, MHLEN, and so on, in mbuf consumers by unifying various alignment
utility functions (M_ALIGN(), MH_ALIGN(), MEXT_ALIGN() in a single
M_ALIGN() macro, implemented by a now-inlined m_align() function:
- Move m_align() from uipc_mbuf.c to mbuf.h; mark as __inline.
- Reimplement M_ALIGN(), MH_ALIGN(), and MEXT_ALIGN() using m_align().
- Update consumers around the tree to simply use M_ALIGN().
This change eliminates a number of cases where mbuf consumers must be aware
of whether or not mbufs returned by the allocator use external storage, but
also assumptions about the size of the returned mbuf. This will make it
easier to introduce changes in how we use external storage, as well as
features such as variable-size mbufs.
Differential Revision: https://reviews.freebsd.org/D1436
Reviewed by: glebius, trasz, gnn, bz
Sponsored by: EMC / Isilon Storage Division
Phabric: https://reviews.freebsd.org/D1247
Reviewed by: jhb, avg
Sponsored by: Spectra Logic Corporation
sys/kern_subr_taskqueue.c:
Modify taskqueue_drain_all() processing to use a temporary
"barrier task", rather than rely on a user task that may
be destroyed during taskqueue_drain_all()'s execution. The
barrier task is queued behind all previously queued tasks
and then has its priority elevated so that future tasks
cannot pass it in the queue.
Use a similar barrier scheme to drain threads processing
current tasks. This requires taskqueue_run_locked() to
insert and remove the taskqueue_busy object for the running
thread for every task processed.
share/man/man9/taskqueue.9:
Remove warning about live-lock issues with taskqueue_drain_all()
and indicate that it does not wait for tasks queued after
it begins processing.
in r276564, change path type to char * (pathnames are always char *).
And remove bogus casts of malloc().
kern___getcwd() internally doesn't actually use or support u_char *
paths, except to copy them to a normal char * path.
These changes are not visible to libc as libc/gen/getcwd.c misdeclares
__getcwd() as taking a plain char * path.
While here remove _SYS_SYSPROTO_H_ for __getcwd() syscall as
we always have sysproto.h.
Pointed out by: bde
MFC after: 1 week
clients, hence they might not handle it very well. This change allows
debugging mutex problems with kernel console drivers when
"debug.witness.skipspin=0" is set in the boot environment.
MFC after: 1 week
witness printouts in the console driver clients can cause this mutex
to recurse by calls to "printf()" from witness for example. In
particular this can happen if "debug.witness.skipspin=0" is set in the
boot environment.
MFC after: 1 week
locks/unlocks the vnode and does a VOP_GETATTR()
for the SEEK_END case. This is safe to do, since
lf_advlock{async}() only uses the size argument
for the SEEK_END case.
The NFSv4 server needs this when
vfs.nfsd.enable_locallocks!=0 since locking the
vnode results in a LOR that can cause a deadlock
for the nfsd threads.
Reviewed by: kib
MFC after: 1 week
the created file name was cached. Use the flag for core dumps.
Requested by: rpaulo
Tested by: pho (previous version)
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
(UTC) rather than the archaic (GMT) in comments. Except where the
comments are making fun of people doing this (and pedants who insist
on the new terms).
why there could appear a zero-sized mbufs in socket buffers.
A proper fix would be to divorce record socket buffers and stream
socket buffers, and divorce pru_send that accepts normal data from
pru_send that accepts control data.
in sbappend_locked() and sbappendrecord_locked().
This is a quick fix to the panic introduced by r274712.
A proper solution should be to make sosend_generic() avoid calling
pru_send() with NULL mbuf for the protocols that do not understand
control messages. Those protocols that understand control messages,
should be able to receive NULL mbuf, if control is non-NULL.
into namecache, to avoid cache trashing when doing large operations.
E.g., tar archive extraction is not usually followed by access to many
of the files created.
Right now, each VOP_LOOKUP() implementation explicitely knowns about
this quirk and tests for both MAKEENTRY flag presence and op != CREATE
to make the call to cache_enter(). Centralize the handling of the
quirk into VFS, by deciding to cache only by MAKEENTRY flag in VOP.
VFS now sets NOCACHE flag for CREATE namei() calls.
Note that the change in semantic is backward-compatible and could be
merged to the stable branch, and is compatible with non-changed
third-party filesystems which correctly handle MAKEENTRY.
Suggested by: Chris Torek <torek@pi-coral.com>
Reviewed by: mckusick
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
the orphaned descendants. Base of the API is modelled after the same
feature from the DragonFlyBSD.
Requested by: bapt
Reviewed by: jilles (previous version)
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 3 weeks
A _NEW flag passed to _init_flags() to avoid check for double-init.
Differential Revision: https://reviews.freebsd.org/D1208
Reviewed by: jhb, wblock
MFC after: 1 Month
feature is to quisce the system before suspend.
Stop is implemented by reusing the thread_single(9) with the special
mode SINGLE_ALLPROC. SINGLE_ALLPROC differs from the existing
single-threading modes by allowing (requiring) caller to operate on
other process. Interruptible sleeps for !TDF_SBDRY threads are
suspended like SIGSTOP does it, instead of aborting the sleep, like
SINGLE_NO_EXIT, to avoid spurious EINTRs on resume.
Provide debugging sysctl debug.stop_all_proc, which causes total stop
and suspends syncer, while waiting for variable reset for resume. It
is used for debugging; should be removed after the real use of the
interface is added.
In collaboration with: pho
Discussed with: avg
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
filesystem specified VFCF_SBDRY flag, i.e. for NFS.
There are two issues with the sleeps. First, applications may get
unexpected EINTR from the disk i/o syscalls. Second, interruptible
sleep allows the stop of the process, and since mount point is
referenced while thread sleeps, unmount cannot free mount point
structure' memory, blocking unmount indefinitely.
Even for NFS, it is probably only reasonable to enable PCATCH for intr
mounts, but this information is currently not available at VFS level.
Reported and tested by: pho (previous version)
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
creating delayed write buffers belonging to the reclaimed vnode. Put
the buffer cleanup code after inactivation.
Add asserts that ensure that buffer queues are empty and add BO_DEAD
flag for bufobj to check that no buffers are added after the cleanup.
BO_DEAD is only used by INVARIANTS-enabled kernels.
Reported and tested by: pho (previous version)
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Since VFS does not/cannot stop writes, sync might run indefinitely, or
be a wrong thing to do at all. E. g. NFS ignores VFS_SYNC() for
forced unmounts, since non-responding server does not allow sync to
finish. On the other hand, filesystems can and do stop writes using
fs-specific facilities, and should already fully flush caches in
VFS_UNMOUNT() due to the race.
Adjust msdosfs tp sync in unmount for forced call, to accomodate the
new behaviour. Note that it is still racy, since writes are not
stopped.
Discussed with: avg, bjk, mckusick
Reported and tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 3 weeks
to be called before suspension and after resume, correspondingly. The
syncer_suspend() ensures that all filesystems dirty data and metadata
are saved to the permanent storage, and stops kernel threads which
might modify filesystems. The syncer_resume() restores stopped
threads.
For now, only syncer is stopped. This is needed, because each sync
loop causes superblock updates for UFS.
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
the vnode owning the buffer is not locked. More, it cannot be locked
safely, since getnewbuf_reuse_bp() is called from newbuf(), and some
other vnode is already locked, for which reused buffer will be
reassigned.
As the consequence, reclamation of the owning vnode could go in
parallel, in particular, the call to vnode_destroy_vobject(), which
deallocates the vm object and zeroes the v_bufobj->bo_object. Note
that the pages wired by the buffer are left wired and can be safely
freed by the vfs_vmio_release() without the need for the vm object
lock. Also, seeing stale pointer to the v_object is safe due to vm
object type stability.
Check for bo_bufobj != NULL and cache the value in local variable to
avoid trying to lock NULL vm object.
Reported and tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
preparation for the global stop commit.
Move the code to weed suspended or sleeping threads into the
appropriate state, into the helper weed_inhib(). Current code already
has deep nesting and hard to follow [1].
Add currently useless helper remain_for_mode(), which returns the
count of threads which are allowed to run, according to the
single-threading mode.
In thread_single_end(), do not save curthread into local variable, it
is unused after, except to find curproc.
Remove stray empty line.
Requested by: avg [1]
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
for the suspension.
Currently, the loop performs uninterruptible cv_wait(9) call, which
prevents suspension until child allows further execution of parent.
If child is stopped, suspension or single-threading is delayed
indefinitely.
Create a helper thread_suspend_check_needed() to identify the need for
a call to thread_suspend_check(). It is required since call to the
thread_suspend_check() cannot be safely done while owning the child
(p2) process lock. Only when suspension is needed, drop p2 lock and
call thread_suspend_check(). Perform wait for cv with timeout, in
case suspend is requested after wait started; I do not see a better
way to interrupt the wait.
Reported and tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
multithreaded status of the process.
The stopped state must be cleared before P_WEXIT is set. A stop
signal delivered just before first PROC_LOCK() block in exit1(9) would
put the process into pending stop with P_WEXIT set or assertion
triggered. Also recheck for the suspension after failed
thread_single(9) call, since process lock could be dropped.
Reported and tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
In the old days callout(9) had 1 tick precision and that was inadequate
for some uses, e.g. DTrace profile module, so we had to emulate cyclic
API and behavior. Now we can directly use callout(9) in the very few
places where cyclic was used.
Differential Revision: https://reviews.freebsd.org/D1161
Reviewed by: gnn, jhb, markj
MFC after: 2 weeks
