you run out of mbuf address space.
kern/subr_mbuf.c: print a warning message when mb_alloc fails, again
rate-limited to at most once per second. This covers other
cases of mbuf allocation failures. Probably it also overlaps the
one handled in vm/vm_kern.c, so maybe the latter should go away.
This warning will let us gradually remove the printf that are scattered
across most network drivers to report mbuf allocation failures.
Those are potentially dangerous, in that they are not rate-limited and
can easily cause systems to panic.
Unless there is disagreement (which does not seem to be the case
judging from the discussion on -net so far), and because this is
sort of a safety bugfix, I plan to commit a similar change to STABLE
during the weekend (it affects kern/uipc_mbuf.c there).
Discussed-with: jlemon, silby and -net
the administrator to restrict access to the kernel message buffer.
It defaults to '1', which permits access, but if set to '0', requires
that the process making the sysctl() have appropriate privilege.
o Note that for this to be effective, access to this data via system
logs derived from /dev/klog must also be limited.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, NAI Labs
that new models can inhabit kern.security.<modelname>.
o While I'm there, shorten somewhat excessive variable names, and clean
things up a little.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, NAI Labs
readability.
o Conditionalize only the SYSCTL definitions for the regression
tree, not the variables itself, decreasing the number of #ifdef
REGRESSIONs scattered in kern_mib.c, and making the code more
readable.
Sponsored by: DARPA, NAI Labs
For an object type, we maintain a variable mb_mapfull. It is 0 by default
and is only raised to 1 in one place: when an mb_pop_cont() fails for
the first time, on the assumption that the reason for the failure is
due to the underlying map for the object (e.g. clust_map, mbuf_map) being
exhausted.
Problem and Changes:
Change how we define "mb_mapfull." It now means: "set to 1 when the first
mb_pop_cont() fails only in the kmem_malloc()-ing of the object, and
only if the call was with the M_TRYWAIT flag." This is a more conservative
definition and should avoid odd [but theoretically possible] situations
from occuring. i.e. we had set mb_mapfull to 1 thinking the map for the
object was actually exhausted when we _actually_ failed in malloc()ing
the space for the bucket structure managing the objects in the page
we're allocating.
The kernel certainly doesn't use _PATH_DEV or even /dev/ to find the device.
It cannot, since "/" has not been mounted. Maybe the only affect of using
/dev/ is that it gets put in the mounted-from name for "/", so that mount(8),
etc., display an absolute path before "/" has been remounted. Many have
never bothered typing the full path, and code that constructs a path in
rootdevnames[] never bothered to construct a full path, so the example
shouldn't have it.
Submitted by: bde
vnodes. This will hopefully serve as a base from which we can
expand the MP code. We currently do not attempt to obtain any
mutex or SX locks, but the door is open to add them when we nail
down exactly how that part of it is going to work.
Replace uses of holdfp() with fget*() or fgetvp*() calls as appropriate
introduce fget(), fget_read(), fget_write() - these functions will take
a thread and file descriptor and return a file pointer with its ref
count bumped.
introduce fgetvp(), fgetvp_read(), fgetvp_write() - these functions will
take a thread and file descriptor and return a vref()'d vnode.
*_read() requires that the file pointer be FREAD, *_write that it be
FWRITE.
This continues the cleanup of struct filedesc and struct file access
routines which, when are all through with it, will allow us to then
make the API calls MP safe and be able to move Giant down into the fo_*
functions.
- Restore inferior() to being iterative rather than recursive.
- Assert that the proctree_lock is held in inferior() and change the one
caller to get a shared lock of it. This also ensures that we hold the
lock after performing the check so the check can't be made invalid out
from under us after the check but before we act on it.
Requested by: bde
one to perform a vn_open using temporary/other/fake credentials.
Modify the nfs client side locking code to use vn_open_cred() passing
proc0's ucred instead of the old way which was to temporary raise
privs while running vn_open(). This should close the race hopefully.
as being valid. Previously only the magic number and the virtual
address were checked, but it makes little sense to require that
the virtual address is the same (the message buffer is located at
the end of physical memory), and checks on the msg_bufx and msg_bufr
indices were missing.
Submitted by: Bodo Rueskamp <br@clabsms.de>
Tripped over during a kernel debugging tutorial given by: grog
Reviewed by: grog, dwmalone
MFC after: 1 week
sysctl_req', which describes in-progress sysctl requests. This permits
sysctl handlers to have access to the current thread, permitting work
on implementing td->td_ucred, migration of suser() to using struct
thread to derive the appropriate ucred, and allowing struct thread to be
passed down to other code, such as network code where td is not currently
available (and curproc is used).
o Note: netncp and netsmb are not updated to reflect this change, as they
are not currently KSE-adapted.
Reviewed by: julian
Obtained from: TrustedBSD Project
consistent with the one other function in the file, and prevents long
lines in up-coming changes. This nominally pulls kern_mib.c a little
further down the long path to style(9) compliance.
in wdrain during a write. This flag needs to be used in devices whos
strategy routines turn-around and issue another high level I/O, such as
when MD turns around and issues a VOP_WRITE to vnode backing store, in order
to avoid deadlocking the dirty buffer draining code.
Remove a vprintf() warning from MD when the backing vnode is found to be
in-use. The syncer of buf_daemon could be flushing the backing vnode at
the time of an MD operation so the warning is not correct.
MFC after: 1 week
