the number of references on the filesystem root vnode to be both
expected and released. Many filesystems hold an extra reference on
the filesystem root vnode, which must be accounted for when
determining if the filesystem is busy and then released if it isn't
busy. The old `skipvp' approach required individual filesystem
xxx_unmount functions to re-implement much of vflush()'s logic to
deal with the root vnode.
All 9 filesystems that hold an extra reference on the root vnode
got the logic wrong in the case of forced unmounts, so `umount -f'
would always fail if there were any extra root vnode references.
Fix this issue centrally in vflush(), now that we can.
This commit also fixes a vnode reference leak in devfs, which could
result in idle devfs filesystems that refuse to unmount.
Reviewed by: phk, bp
- Require the proc lock be held for killproc() to allow for the vmdaemon to
kill a process when memory is exhausted while holding the lock of the
process to kill.
When people access /dev/tty, locate their controlling tty and return
the dev_t of it to them. This basically makes /dev/tty act like
a variant symlink sort of thing which is much simpler than all the
mucking about with vnodes.
- Since polling should not involve sleeping, keep holding a
process lock upon scanning file descriptors.
- Hold a reference to every file descriptor prior to entering
polling loop in order to avoid lock order reversal between
lockmgr and p_mtx upon calling fdrop() in fo_poll().
(NOTE: this work has not been done for netncp and netsmb
yet because a socket itself has no reference counts.)
Reviewed by: jhb
KASSERT when vp->v_usecount is zero or negative. In this case, the
"v*: negative ref cnt" panic that follows is much more appropriate.
Reviewed by: mckusick
fail due to witness exhausting its internal resources and shutting down.
Reported by: Szilveszter Adam <sziszi@petra.hos.u-szeged.hu>
Tested by: David Wolfskill <david@catwhisker.org>
The pipe code could not handle running out of kva, it would panic
if that happened. Instead return ENFILE to the application which
is an acceptable error return from pipe(2).
There was some slightly tricky things that needed to be worked on,
namely that the pipe code can 'realloc' the size of the buffer if
it detects that the pipe could use a bit more room. However if it
failed the reallocation it could not cope and would panic. Fix
this by attempting to grow the pipe while holding onto our old
resources. If all goes well free the old resources and use the
new ones, otherwise continue to use the smaller buffer already
allocated.
While I'm here add a few blank lines for style(9) and remove
'register'.
process on fork(2).
It is the supposed behavior stated in the manpage of sigaction(2), and
Solaris, NetBSD and FreeBSD 3-STABLE correctly do so.
The previous fix against libc_r/uthread/uthread_fork.c fixed the
problem only for the programs linked with libc_r, so back it out and
fix fork(2) itself to help those not linked with libc_r as well.
PR: kern/26705
Submitted by: KUROSAWA Takahiro <fwkg7679@mb.infoweb.ne.jp>
Tested by: knu, GOTOU Yuuzou <gotoyuzo@notwork.org>,
and some other people
Not objected by: hackers
MFC in: 3 days
implementation. Move from direct uid 0 comparision to using suser_xxx()
call with the same semantics. Simplify CAN_AFFECT() macro as passed
pcred was redundant. The checks here still aren't "right", but they
are probably "better".
Obtained from: TrustedBSD Project
struct lock_instance that is stored in the per-process and per-CPU lock
lists. Previously, the lock lists just kept a pointer to each lock held.
That pointer is now replaced by a lock instance which contains a pointer
to the lock object, the file and line of the last acquisition of a lock,
and various flags about a lock including its recursion count.
- If we sleep while holding a sleepable lock, then mark that lock instance
as having slept and ignore any lock order violations that occur while
acquiring Giant when we wake up with slept locks. This is ok because of
Giant's special nature.
- Allow witness to differentiate between shared and exclusive locks and
unlocks of a lock. Witness will now detect the case when a lock is
acquired first in one mode and then in another. Mutexes are always
locked and unlocked exclusively. Witness will also now detect the case
where a process attempts to unlock a shared lock while holding an
exclusive lock and vice versa.
- Fix a bug in the lock list implementation where we used the wrong
constant to detect the case where a lock list entry was full.
uses lockmgr locks and this leads to a lock order reversal. At this point
in wait1() the process is not on any process lists or in the process tree,
so no other process should be able to find it or have a reference to it
anyways, so the locking is not needed.
other "system" header files.
Also help the deprecation of lockmgr.h by making it a sub-include of
sys/lock.h and removing sys/lockmgr.h form kernel .c files.
Sort sys/*.h includes where possible in affected files.
OK'ed by: bde (with reservations)
- add a missing break which caused RTP_SET to always return EINVAL
- break instead of returning if p_can fails so proc_lock is always
dropped correctly
- only copyin data that is actually needed
- use break instead of goto
- make rtp_to_pri return EINVAL instead of -1 if the values are out
or range so we don't have to translate
and gid in the ACL, vaccess_acl_posix1e() was changed to accept
explicit file_uid and file_gid as arguments. However, in making the
change, I explicitly checked file_gid against cr->cr_groups[0], rather
than using groupmember, resulting in ACL_GROUP_OBJ entries being
compared to the caller's effective gid only, not the remainder of
its groups. This was recently corrected for the version of the
group call without privilege, but the second test (when privilege is
added) was missed. This change replaces an additiona cr->cr_groups[0]
check with groupmember().
Pointed out by: jedgar
Reviewed by: jedgar
Obtained from: TrustedBSD Project
Make 7 filesystems which don't really know about VOP_BMAP rely
on the default vector, rather than more or less complete local
vop_nopbmap() implementations.
been made machine independent and various other adjustments have been made
to support Alpha SMP.
- It splits the per-process portions of hardclock() and statclock() off
into hardclock_process() and statclock_process() respectively. hardclock()
and statclock() call the *_process() functions for the current process so
that UP systems will run as before. For SMP systems, it is simply necessary
to ensure that all other processors execute the *_process() functions when the
main clock functions are triggered on one CPU by an interrupt. For the alpha
4100, clock interrupts are delievered in a staggered broadcast fashion, so
we simply call hardclock/statclock on the boot CPU and call the *_process()
functions on the secondaries. For x86, we call statclock and hardclock as
usual and then call forward_hardclock/statclock in the MD code to send an IPI
to cause the AP's to execute forwared_hardclock/statclock which then call the
*_process() functions.
- forward_signal() and forward_roundrobin() have been reworked to be MI and to
involve less hackery. Now the cpu doing the forward sets any flags, etc. and
sends a very simple IPI_AST to the other cpu(s). AST IPIs now just basically
return so that they can execute ast() and don't bother with setting the
astpending or needresched flags themselves. This also removes the loop in
forward_signal() as sched_lock closes the race condition that the loop worked
around.
- need_resched(), resched_wanted() and clear_resched() have been changed to take
a process to act on rather than assuming curproc so that they can be used to
implement forward_roundrobin() as described above.
- Various other SMP variables have been moved to a MI subr_smp.c and a new
header sys/smp.h declares MI SMP variables and API's. The IPI API's from
machine/ipl.h have moved to machine/smp.h which is included by sys/smp.h.
- The globaldata_register() and globaldata_find() functions as well as the
SLIST of globaldata structures has become MI and moved into subr_smp.c.
Also, the globaldata list is only available if SMP support is compiled in.
Reviewed by: jake, peter
Looked over by: eivind
modify the scheduling properties of processes with a different real
uid but the same effective uid (i.e., daemons, et al). (note: these
cases were previously commented out, so this does not change the
compiled code at al)
Obtained from: TrustedBSD Project
sf_hdtr is used to provide writev(2) style headers/trailers on the
sent data the return value is actually either the result of writev(2)
from the trailers or headers of no tailers are specified.
Fix sendfile to comply with the documentation, by returning 0 on
success.
Ok'd by: dg
by the inactive routine. Because the freeing causes the filesystem
to be modified, the close must be held up during periods when the
filesystem is suspended.
For snapshots to be consistent across crashes, they must write
blocks that they copy and claim those written blocks in their
on-disk block pointers before the old blocks that they referenced
can be allowed to be written.
Close a loophole that allowed unwritten blocks to be skipped when
doing ffs_sync with a request to wait for all I/O activity to be
completed.
to struct mount.
This makes the "struct netexport *" paramter to the vfs_export
and vfs_checkexport interface unneeded.
Consequently that all non-stacking filesystems can use
vfs_stdcheckexp().
At the same time, make it a pointer to a struct netexport
in struct mount, so that we can remove the bogus AF_MAX
and #include <net/radix.h> from <sys/mount.h>
nam for an unbound socket instead of leaving nam untouched in that case.
This way, the getsockname() output can be used to determine the address
family of such sockets (AF_LOCAL).
Reviewed by: iedowse
Approved by: rwatson
