The PR and patch have the details. The ultimate fix requires architectural
changes and clarifications to the VFS API, but this will prevent the system
from panicking when someone does "ls /dev" while running in a shell under the
linuxulator.
This issue affects HEAD and RELENG_6 only.
PR: 88249
Submitted by: "Devon H. O'Dell" <dodell@ixsystems.com>
MFC after: 3 days
- Prefer '_' to ' ', as it results in more easily parsed results in
memory monitoring tools such as vmstat.
- Remove punctuation that is incompatible with using memory type names
as file names, such as '/' characters.
- Disambiguate some collisions by adding subsystem prefixes to some
memory types.
- Generally prefer lower case to upper case.
- If the same type is defined in multiple architecture directories,
attempt to use the same name in additional cases.
Not all instances were caught in this change, so more work is required to
finish this conversion. Similar changes are required for UMA zone names.
cache_lookup() has returned a ref'ed and locked vnode since
vfs_cache.c:1.96, dated Tue Mar 29 12:59:06 2005 UTC. This change
is similar to the change made to smbfs_lookup() in smbfs_vnops.c:1.58.
Tested by: "Antony Mawer" ant AT mawer.org
MFC after: 2 weeks
I benchmarked this by simultaneously extracting 4 large tarballs (basically
world images) on a 4-processor AMD64 system, in a malloc-backed md.
With this patch, system time was reduced by 43%, and wall clock time by 33%.
Submitted by: jeff
MFC after: 1 week
cd9660_lookup() that was used to fix an actual race in ufs_lookup.c:1.78.
This is not currently a hazard, but the bug would be activated by
marking cd9660 as MPSAFE.
Requested by: bde
provided in the kernel build directory, fix modules that were
failing to build this way due to not quite correct kernel option
usage. In particular:
ng_mppc.c uses two complementary options, both of which are listed
in sys/conf/files. Ideally, there should be a separate option for
including ng_mppc.c in kernel build, but now only
NETGRAPH_MPPC_ENCRYPTION is usable anyway, the other one requires
proprietary files.
nwfs and smbfs were trying to ensure they were built with proper
network components, but the check was rather questionable.
Discussed with: ru
changes in MD code are trivial, before this change, trapsignal and
sendsig use discrete parameters, now they uses member fields of
ksiginfo_t structure. For sendsig, this change allows us to pass
POSIX realtime signal value to user code.
2. Remove cpu_thread_siginfo, it is no longer needed because we now always
generate ksiginfo_t data and feed it to libpthread.
3. Add p_sigqueue to proc structure to hold shared signals which were
blocked by all threads in the proc.
4. Add td_sigqueue to thread structure to hold all signals delivered to
thread.
5. i386 and amd64 now return POSIX standard si_code, other arches will
be fixed.
6. In this sigqueue implementation, pending signal set is kept as before,
an extra siginfo list holds additional siginfo_t data for signals.
kernel code uses psignal() still behavior as before, it won't be failed
even under memory pressure, only exception is when deleting a signal,
we should call sigqueue_delete to remove signal from sigqueue but
not SIGDELSET. Current there is no kernel code will deliver a signal
with additional data, so kernel should be as stable as before,
a ksiginfo can carry more information, for example, allow signal to
be delivered but throw away siginfo data if memory is not enough.
SIGKILL and SIGSTOP have fast path in sigqueue_add, because they can
not be caught or masked.
The sigqueue() syscall allows user code to queue a signal to target
process, if resource is unavailable, EAGAIN will be returned as
specification said.
Just before thread exits, signal queue memory will be freed by
sigqueue_flush.
Current, all signals are allowed to be queued, not only realtime signals.
Earlier patch reviewed by: jhb, deischen
Tested on: i386, amd64
the UDF specification specifies a logical sectorsize of 2048.
Instead, get it from GEOM.
- When reading the UDF Anchor Volume Descriptor, use the logical
sectorsize of 2048 when calculating the offset to read from, but
use the actual sectorsize to determine how much to read.
- works with reading a DVD disk and a DVD disk image file via mdconfig
- correctly returns EINVAL if we try to mount_udf an audio CD, instead
of panicking inside GEOM when INVARIANTS is set
sys/fs/nwfs/nwfs_vfsop= s.c, introduced with the conversion to
nmount with revision 1.38. This causes mount_nwfs to fail with
the error message:
mount_nwfs: mount error: /mnt/netware: syserr = No such file or directo=
ry
This is caused by a typo on line 178, which specifies "nwfw_args"
rather than "nwfs_args".
Submitted by: Antony Mawer <gnats@mawer.org>
Fat fingers: phk
PR: 86757
MFC: 3 days
There seems to be very little documentary evidence outside this
implementation to suggest a these checks are neccessary, and more
than one camera-formatted flash disk fails the check, but mounts
successfully on most other systems.
Reviewed By: bde@
a fifo. While this did indeed close the race, confirming suspicions
about the nature of the problem, it causes difficulties with blocking
I/O on fifos.
Discussed with: ups
Also spotted by: Peter Holm <peter at holm dot cc>
that socket during open, not the write socket receive buffer. This
might explain clearing of the sb_state SB_LOCK flag seen occasionally
in soreceive() on fifos.
MFC after: 3 days
Spotted by: ups
when we mount and get zero cost if no rules are used in a mountpoint.
Add code to deref rules on unmount.
Switch from SLIST to TAILQ.
Drop SYSINIT, use SX_SYSINIT and static initializer of TAILQ instead.
Drop goto, a break will do.
Reduce double pointers to single pointers.
Combine reaping and destroying rulesets.
Avoid memory leaks in a some error cases.
underlying the POSIX fifo implementation. In 6.x/7.x, fifo access is
moved from the VFS layer, where it was serialized using the vnode
lock, to the file descriptor layer, where access is protected by a
reference count but not serialized. This exposed socket buffer
locking to high levels of parallelism in specific fifo workloads, such
as make -j 32, which expose as yet unresolved socket buffer bugs.
fi_sx re-adds serialization about the read and write routines,
although not paths that simply test socket buffer mbuf queue state,
such as the poll and kqueue methods. This restores the extra locking
cost previously present in some cases, but is an effective workaround
for the instability that has been experienced. This workaround should
be removed once the bug in socket buffer handling has been fixed.
Reported by: kris, jhb, Julien Gabel <jpeg at thilelli dot net>,
Peter Holm <peter at holm dot cc>, others
MFC after: 3 days
Give DEVFS a proper inode called struct cdev_priv. It is important
to keep in mind that this "inode" is shared between all DEVFS
mountpoints, therefore it is protected by the global device mutex.
Link the cdev_priv's into a list, protected by the global device
mutex. Keep track of each cdev_priv's state with a flag bit and
of references from mountpoints with a dedicated usecount.
Reap the benefits of much improved kernel memory allocator and the
generally better defined device driver APIs to get rid of the tables
of pointers + serial numbers, their overflow tables, the atomics
to muck about in them and all the trouble that resulted in.
This makes RAM the only limit on how many devices we can have.
The cdev_priv is actually a super struct containing the normal cdev
as the "public" part, and therefore allocation and freeing has moved
to devfs_devs.c from kern_conf.c.
The overall responsibility is (to be) split such that kern/kern_conf.c
is the stuff that deals with drivers and struct cdev and fs/devfs
handles filesystems and struct cdev_priv and their private liason
exposed only in devfs_int.h.
Move the inode number from cdev to cdev_priv and allocate inode
numbers properly with unr. Local dirents in the mountpoints
(directories, symlinks) allocate inodes from the same pool to
guarantee against overlaps.
Various other fields are going to migrate from cdev to cdev_priv
in the future in order to hide them. A few fields may migrate
from devfs_dirent to cdev_priv as well.
Protect the DEVFS mountpoint with an sx lock instead of lockmgr,
this lock also protects the directory tree of the mountpoint.
Give each mountpoint a unique integer index, allocated with unr.
Use it into an array of devfs_dirent pointers in each cdev_priv.
Initially the array points to a single element also inside cdev_priv,
but as more devfs instances are mounted, the array is extended with
malloc(9) as necessary when the filesystem populates its directory
tree.
Retire the cdev alias lists, the cdev_priv now know about all the
relevant devfs_dirents (and their vnodes) and devfs_revoke() will
pick them up from there. We still spelunk into other mountpoints
and fondle their data without 100% good locking. It may make better
sense to vector the revoke event into the tty code and there do a
destroy_dev/make_dev on the tty's devices, but that's for further
study.
Lots of shuffling of stuff and churn of bits for no good reason[2].
XXX: There is still nothing preventing the dev_clone EVENTHANDLER
from being invoked at the same time in two devfs mountpoints. It
is not obvious what the best course of action is here.
XXX: comment out an if statement that lost its body, until I can
find out what should go there so it doesn't do damage in the meantime.
XXX: Leave in a few extra malloc types and KASSERTS to help track
down any remaining issues.
Much testing provided by: Kris
Much confusion caused by (races in): md(4)
[1] You are not supposed to understand anything past this point.
[2] This line should simplify life for the peanut gallery.
running" panics.
Previously, recursion through the "include" feature was prevented by
marking each ruleset as "running" when applied. This doesn't work for
the case where two DEVFS instances try to apply the same ruleset at
the same time.
Instead introduce the sysctl vfs.devfs.rule_depth (default == 1) which
limits how many levels of "include" we will traverse.
Be aware that traversal of "include" is recursive and kernel stack
size is limited.
MFC: after 3 days
fifo_kqfilter() VOP implementations, since they in theory are used
only on open file descriptors, in which case the ioctls are via
fifo_ioctl_f() and kqueue requests are via fifo_kqfilter_f().
Generate warnings if they are entered for now. These printf()
calls should become panic() calls.
Annotate and re-implement fifo_ioctl_f(): don't arbitrarily
forward ioctls to the socket layer, only forward the ones we
explicitly support for fifos. In the case of FIONREAD, don't
forward the request to the write socket on a read-write fifo, or
the read result is overwritten. Annotate a nasty case for the
undefined POSIX O_RDWR on fifos, in which failure of the second
ioctl will result in the socket pair being in an inconsistent
state.
Assert copyright as I find myself rewriting non-trivial parts of
fifofs.
MFC after: 3 days
be held when entering a kqueue filter for fifos via a socket buffer
event: as such, assert the lock unconditionally rather than acquiring
it conditionall.
MFC after: 3 days
1) fifo_kqfilter() is not actually ever used, it likely should be GC'd.
2) fifo_kqfilter_f() doesn't implement EVFILT_VNODE, so detecting events
on the underlying vnode for a fifo no longer works (it did in 4.x).
Likely, fifo_kqfilter_f() should forward the request to the VFS using
fp->f_vnode, which would work once fifo_kqfilter() was detached from
the vnode operation vector (removing the fifo override).
Discussed with: phk
used when a read filter is requested on a write-only fifo descriptor, or
a write filter is requested on a read-only fifo descriptor. This
permits the filters to be registered, but never raises the event, which
causes kqueue behavior for fifos to more closely match similar semantics
for poll and select, which permit testing for the condition even though
the condition will never be raised, and is consistent with POSIX's notion
that a fifo has identical semantics to a one-way IPC channel created
using pipe() on most operating systems.
The fifo regression test suite can now run to completion on HEAD without
errors.
MFC after: 3 days
according to POSIX, not to mention the fact that it doesn't make sense
(and hence isn't really implemented). This causes the fifo_misc
regression test to succeed.
file descriptor. Otherwise, the read end of a fifo might return that it
is writable (which it isn't).
Only poll the fifo for write events if the fifo attached to a writable
file descriptor. Otherwise, the write end of a fifo might return that
it is readable (which it isn't).
In the event that a file is FREAD|FWRITE (which is allowed by POSIX, but
has undefined behavior), we poll for both.
MFC after: 3 days
to poll the write socket for, the fifo polling code proceeded to poll
for the complete set of events. Use 'levents' instead of 'events' as
the argument to poll, and only poll the write socket if there is
interest in write events.
MFC after: 3 days
while sleeping to allocate fifo state: due to using the vnode lock to
serialize access to a fifo during open, it shouldn't happen (tm).
MFC after: 3 days
