from the userland and pushes results back and the second which does
actual processing. Use the latter to eliminate stackgap in the linux wrapper
of that syscall.
MFC after: 2 weeks
pops data from the userland and pushes results back and the second which does
actual processing. Use the latter to eliminate stackgap in the linux wrappers
of those syscalls.
MFC after: 2 weeks
missed that when the vnode bypass was introduced.
Deal with zero length transfers before we even get to fo_ops->fo_read().
Found by: Slawa Olhovchenkov <slwzxy.spb.ru@zxy.spb.ru>
PR: 75758
the name Sande^H^H^H^H^Hvnode_create_vobject().
Make the new function take a size argument which removes the need for
a VOP_STAT() or a very pessimistic guess for disks.
Call that new function from vop_stdcreatevobject().
Make vnode_pager_alloc() private now that its only user came home.
short to unsigned short.
- Add SYSCTL_PROC() around somaxconn, not accepting values < 1 or > U_SHRTMAX.
Before this change setting somaxconn to smth above 32767 and calling
listen(fd, -1) lead to a socket, which doesn't accept connections at all.
Reviewed by: rwatson
Reported by: Igor Sysoev
- Remove some KASSERTs which are invalid if the appropriate lock is
not held.
- Slightly restructure bremfree() so that it is more sane.
- Change the flush code in bdwrite() to avoid acquiring a mutex
whenever possible.
- Change the flush code in bdwrite() to avoid holding the bufobj mutex
while calling buf_countdeps(). This introduces a lock-order
relationship with the softdep lock that can not otherwise be resolved.
- Don't set B_DONE until bufdone() is complete, otherwise another
processor may believe the buf is done before it is.
- Only acquire Giant if the caller has set b_iodone. Don't grab giant
around normal bufdone() calls.
Sponsored By: Isilon Systems, Inc.
to off.
- Protect access to mnt_kern_flag with the mointpoint mutex.
- Remove some KASSERTs which are not legal checks without the appropriate
locks held.
- Use VCANRECYCLE() rather than rolling several slightly different
checks together.
- Return from vtryrecycle() with a recycled vnode rather than a locked
vnode. This simplifies some locking.
- Remove several GIANT_REQUIRED lines.
- Add a few KASSERTs to help with INACT debugging.
Sponsored By: Isilon Systems, Inc.
- Protect access to mnt_kern_flag with the mountpoint mutex.
- Use the appropriate nd flags to deal with giant in vn_open_cred().
We currently determine whether the caller is mpsafe by checking
for a valid fdidx. Any caller coming from user-space is now
mpsafe and supplies a valid fd. No kenrel callers have been
converted to mpsafe, so this check is sufficient for now.
- Use VFS_LOCK_GIANT instead of manual giant acquisition where
appropriate.
Sponsored By: Isilon Systems, Inc.
require it.
- Track the status of Giant with the nd flag HASGIANT.
- Release giant on return of namei() callers are not marked MPSAFE as
they already own giant.
Sponsored By: Isilon Systems, Inc.
vnode lock is much simpler than I originally thought it would be.
Now, the cache lock is always acquired before the vnode lock.
- Provide some gotos in __getcwd() to simplify the unlocking a bit.
- Move Giant acquisition down into __getcwd().
Sponsored By: Isilon Systems, Inc.
if the lockmgr interlock is dropped after the caller's interlock
is dropped.
- Change some lockmgr KTRs to be slightly more helpful.
Sponsored By: Isilon Systems, Inc.
witness_proc_has_locks(), as they are unused, which results in a compiler
error. This problem was introduced with the implementation of "show
alllocks".
Spotted by: Artem Kuchin <matrix at itlegion dot ru>
designed to help detect tamper-after-free scenarios, a problem more
and more common and likely with multithreaded kernels where race
conditions are more prevalent.
Currently MemGuard can only take over malloc()/realloc()/free() for
particular (a) malloc type(s) and the code brought in with this
change manually instruments it to take over M_SUBPROC allocations
as an example. If you are planning to use it, for now you must:
1) Put "options DEBUG_MEMGUARD" in your kernel config.
2) Edit src/sys/kern/kern_malloc.c manually, look for
"XXX CHANGEME" and replace the M_SUBPROC comparison with
the appropriate malloc type (this might require additional
but small/simple code modification if, say, the malloc type
is declared out of scope).
3) Build and install your kernel. Tune vm.memguard_divisor
boot-time tunable which is used to scale how much of kmem_map
you want to allott for MemGuard's use. The default is 10,
so kmem_size/10.
ToDo:
1) Bring in a memguard(9) man page.
2) Better instrumentation (e.g., boot-time) of MemGuard taking
over malloc types.
3) Teach UMA about MemGuard to allow MemGuard to override zone
allocations too.
4) Improve MemGuard if necessary.
This work is partly based on some old patches from Ian Dowse.
and always has been, but the system call itself returns
errno in a register so the problem is really a function of
libc, not the system call.
Discussed with : Matthew Dillion <dillon@apollo.backplane.com>
they both happen before pipe backing allocation occurs. Previously,
a pipe memory shortage would cause a panic due to a KNOTE call
on an uninitialized si_note.
Reported by: Peter Holm
MFC after: 1 week
unhappiness lately.
As far as I can tell, no files that have made it safely to disk
have been endangered, but stuff in transit has been in peril.
Pointy hat: phk
