Commit Graph

224 Commits

Author SHA1 Message Date
Ed Schouten
bc093719ca Integrate the new MPSAFE TTY layer to the FreeBSD operating system.
The last half year I've been working on a replacement TTY layer for the
FreeBSD kernel. The new TTY layer was designed to improve the following:

- Improved driver model:

  The old TTY layer has a driver model that is not abstract enough to
  make it friendly to use. A good example is the output path, where the
  device drivers directly access the output buffers. This means that an
  in-kernel PPP implementation must always convert network buffers into
  TTY buffers.

  If a PPP implementation would be built on top of the new TTY layer
  (still needs a hooks layer, though), it would allow the PPP
  implementation to directly hand the data to the TTY driver.

- Improved hotplugging:

  With the old TTY layer, it isn't entirely safe to destroy TTY's from
  the system. This implementation has a two-step destructing design,
  where the driver first abandons the TTY. After all threads have left
  the TTY, the TTY layer calls a routine in the driver, which can be
  used to free resources (unit numbers, etc).

  The pts(4) driver also implements this feature, which means
  posix_openpt() will now return PTY's that are created on the fly.

- Improved performance:

  One of the major improvements is the per-TTY mutex, which is expected
  to improve scalability when compared to the old Giant locking.
  Another change is the unbuffered copying to userspace, which is both
  used on TTY device nodes and PTY masters.

Upgrading should be quite straightforward. Unlike previous versions,
existing kernel configuration files do not need to be changed, except
when they reference device drivers that are listed in UPDATING.

Obtained from:		//depot/projects/mpsafetty/...
Approved by:		philip (ex-mentor)
Discussed:		on the lists, at BSDCan, at the DevSummit
Sponsored by:		Snow B.V., the Netherlands
dcons(4) fixed by:	kan
2008-08-20 08:31:58 +00:00
Konstantin Belousov
f35db5f7ca Remove unnecessary locking around pointer fetch.
Requested by:   jhb
2008-08-12 19:34:45 +00:00
Oleksandr Tymoshenko
2da528a74f Get pointer to devfs_ruleset struct after garbage collection has been
performed. Otherwise if ruleset is used by given mountpoint and is empty
it's freed by devfs_ruleset_reap and pointer becomes bogus.

Submitted by:   Mateusz Guzik <mjguzik@gmail.com>
PR:             kern/124853
2008-06-22 14:34:38 +00:00
Konstantin Belousov
05427aafc6 Struct cdev is always the member of the struct cdev_priv. When devfs
needed to promote cdev to cdev_priv, the si_priv pointer was followed.

Use member2struct() to calculate address of the wrapping cdev_priv.
Rename si_priv to __si_reserved.

Tested by:	pho
Reviewed by:	ed
MFC after:	2 weeks
2008-06-16 17:34:59 +00:00
Konstantin Belousov
9e40a5f827 When devfs_allocv() committed to create new vnode, since de_vnode is NULL,
the dm_lock is held while the newly allocated vnode is locked. Since no
other threads may try to lock the new vnode yet, the LOR there cannot
result in the deadlock.

Shut down the witness warning to note this fact.

Tested by:	pho
Prodded by:	attilio
2008-06-05 09:15:47 +00:00
Ed Schouten
16151645c2 Revert the changes I made to devfs_setattr() in r179457.
As discussed with Robert Watson and John Baldwin, it would be better if
PTY's are created with proper permissions, turning grantpt() into a
no-op.

Bypassing security frameworks like MAC by passing NOCRED to
VOP_SETATTR() will only make things more complex.

Approved by:	philip (mentor)
2008-06-01 14:02:46 +00:00
Ed Schouten
34d1dcf0cc Merge back devfs changes from the mpsafetty branch.
In the mpsafetty branch, PTY's are allocated through the posix_openpt()
system call. The controller side of a PTY now uses its own file
descriptor type (just like sockets, vnodes, pipes, etc).

To remain compatible with existing FreeBSD and Linux C libraries, we can
still create PTY's by opening /dev/ptmx or /dev/ptyXX. These nodes
implement d_fdopen(). Devfs has been slightly changed here, to allow
finit() to be called from d_fdopen().

The routine grantpt() has also been moved into the kernel. This routine
is a little odd, because it needs to bypass standard UNIX permissions.
It needs to change the owner/group/mode of the slave device node, which
may often not be possible. The old implementation solved this by
spawning a setuid utility.

When VOP_SETATTR() is called with NOCRED, devfs_setattr() dereferences
ap->a_cred, causing a kernel panic. Change the de_{uid,gid,mode} code to
allow changes when a->a_cred is set to NOCRED.

Approved by:	philip (mentor)
2008-05-31 14:06:37 +00:00
Konstantin Belousov
772e245341 When vget() fails (because the vnode has been reclaimed), there is no
sense to loop trying to vget() the vnode again.

PR:	122977
Submitted by:	Arthur Hartwig <arthur.hartwig nokia com>
Tested by:	pho
Reviewed by:	jhb
MFC after:	1 week
2008-05-23 16:36:39 +00:00
Konstantin Belousov
82f4d64035 Implement the per-open file data for the cdev.
The patch does not change the cdevsw KBI. Management of the data is
provided by the functions
int	devfs_set_cdevpriv(void *priv, cdevpriv_dtr_t dtr);
int	devfs_get_cdevpriv(void **datap);
void	devfs_clear_cdevpriv(void);
All of the functions are supposed to be called from the cdevsw method
contexts.

- devfs_set_cdevpriv assigns the priv as private data for the file
  descriptor which is used to initiate currently performed driver
  operation. dtr is the function that will be called when either the
  last refernce to the file goes away, the device is destroyed  or
  devfs_clear_cdevpriv is called.
- devfs_get_cdevpriv is the obvious accessor.
- devfs_clear_cdevpriv allows to clear the private data for the still
  open file.

Implementation keeps the driver-supplied pointers in the struct
cdev_privdata, that is referenced both from the struct file and struct
cdev, and cannot outlive any of the referee.

Man pages will be provided after the KPI stabilizes.

Reviewed by:	jhb
Useful suggestions from:	jeff, antoine
Debugging help and tested by:	pho
MFC after:	1 month
2008-05-21 09:31:44 +00:00
John Baldwin
06d0d0e274 Don't explicitly drop Giant around d_open/d_fdopen/d_close for MPSAFE
drivers.  Since devfs is already marked MPSAFE it shouldn't be held
anyway.

MFC after:	2 weeks
Discussed with:	phk
2008-05-07 19:03:57 +00:00
Konstantin Belousov
91a35e7870 Do not dereference cdev->si_cdevsw, use the dev_refthread() to properly
obtain the reference. In particular, this fixes the panic reported in
the PR. Remove the comments stating that this needs to be done.

PR:	kern/119422
MFC after:	1 week
2008-03-20 16:08:42 +00:00
Attilio Rao
81c794f998 Axe the 'thread' argument from VOP_ISLOCKED() and lockstatus() as it is
always curthread.

As KPI gets broken by this patch, manpages and __FreeBSD_version will be
updated by further commits.

Tested by:	Andrea Barberio <insomniac at slackware dot it>
2008-02-25 18:45:57 +00:00
Attilio Rao
22db15c06f VOP_LOCK1() (and so VOP_LOCK()) and VOP_UNLOCK() are only used in
conjuction with 'thread' argument passing which is always curthread.
Remove the unuseful extra-argument and pass explicitly curthread to lower
layer functions, when necessary.

KPI results broken by this change, which should affect several ports, so
version bumping and manpage update will be further committed.

Tested by: kris, pho, Diego Sardina <siarodx at gmail dot com>
2008-01-13 14:44:15 +00:00
Attilio Rao
cb05b60a89 vn_lock() is currently only used with the 'curthread' passed as argument.
Remove this argument and pass curthread directly to underlying
VOP_LOCK1() VFS method. This modify makes the code cleaner and in
particular remove an annoying dependence helping next lockmgr() cleanup.
KPI results, obviously, changed.

Manpage and FreeBSD_version will be updated through further commits.

As a side note, would be valuable to say that next commits will address
a similar cleanup about VFS methods, in particular vop_lock1 and
vop_unlock.

Tested by:	Diego Sardina <siarodx at gmail dot com>,
		Andrea Di Pasquale <whyx dot it at gmail dot com>
2008-01-10 01:10:58 +00:00
John Baldwin
314464f422 Lock the vnode interlock while reading v_usecount to update si_usecount
in a cdev in devfs_reclaim().

MFC after:	3 days
Reviewed by:	jeff (a while ago)
2008-01-08 04:45:24 +00:00
John Baldwin
e46502943a Make ftruncate a 'struct file' operation rather than a vnode operation.
This makes it possible to support ftruncate() on non-vnode file types in
the future.
- 'struct fileops' grows a 'fo_truncate' method to handle an ftruncate() on
  a given file descriptor.
- ftruncate() moves to kern/sys_generic.c and now just fetches a file
  object and invokes fo_truncate().
- The vnode-specific portions of ftruncate() move to vn_truncate() in
  vfs_vnops.c which implements fo_truncate() for vnode file types.
- Non-vnode file types return EINVAL in their fo_truncate() method.

Submitted by:	rwatson
2008-01-07 20:05:19 +00:00
Jeff Roberson
397c19d175 Remove explicit locking of struct file.
- Introduce a finit() which is used to initailize the fields of struct file
   in such a way that the ops vector is only valid after the data, type,
   and flags are valid.
 - Protect f_flag and f_count with atomic operations.
 - Remove the global list of all files and associated accounting.
 - Rewrite the unp garbage collection such that it no longer requires
   the global list of all files and instead uses a list of all unp sockets.
 - Mark sockets in the accept queue so we don't incorrectly gc them.

Tested by:	kris, pho
2007-12-30 01:42:15 +00:00
Robert Watson
30d239bc4c Merge first in a series of TrustedBSD MAC Framework KPI changes
from Mac OS X Leopard--rationalize naming for entry points to
the following general forms:

  mac_<object>_<method/action>
  mac_<object>_check_<method/action>

The previous naming scheme was inconsistent and mostly
reversed from the new scheme.  Also, make object types more
consistent and remove spaces from object types that contain
multiple parts ("posix_sem" -> "posixsem") to make mechanical
parsing easier.  Introduce a new "netinet" object type for
certain IPv4/IPv6-related methods.  Also simplify, slightly,
some entry point names.

All MAC policy modules will need to be recompiled, and modules
not updates as part of this commit will need to be modified to
conform to the new KPI.

Sponsored by:	SPARTA (original patches against Mac OS X)
Obtained from:	TrustedBSD Project, Apple Computer
2007-10-24 19:04:04 +00:00
Pawel Jakub Dawidek
57fd3d5572 When we do open, we should lock the vnode exclusively. This fixes few races:
- fifo race, where two threads assign v_fifoinfo,
- v_writecount modifications,
- v_object modifications,
- and probably more...

Discussed with:	kib, ups
Approved by:	re (rwatson)
2007-07-26 16:58:09 +00:00
Konstantin Belousov
de10ffa527 Since rev. 1.199 of sys/kern/kern_conf.c, the thread that calls
destroy_dev() from d_close() cdev method would self-deadlock.
devfs_close() bump device thread reference counter, and destroy_dev()
sleeps, waiting for si_threadcount to reach zero for cdev without
d_purge method.

destroy_dev_sched() could be used instead from d_close(), to
schedule execution of destroy_dev() in another context. The
destroy_dev_sched_drain() function can be used to drain the scheduled
calls to destroy_dev_sched(). Similarly, drain_dev_clone_events() drains
the events clone to make sure no lingering devices are left after
dev_clone event handler deregistered.

make_dev_credf(MAKEDEV_REF) function should be used from dev_clone
event handlers instead of make_dev()/make_dev_cred() to ensure that created
device has reference counter bumped before cdev mutex is dropped inside
make_dev().

Reviewed by:	tegge (early versions), njl (programming interface)
Debugging help and testing by:	Peter Holm
Approved by:	re (kensmith)
2007-07-03 17:42:37 +00:00
Robert Watson
32f9753cfb Eliminate now-unused SUSER_ALLOWJAIL arguments to priv_check_cred(); in
some cases, move to priv_check() if it was an operation on a thread and
no other flags were present.

Eliminate caller-side jail exception checking (also now-unused); jail
privilege exception code now goes solely in kern_jail.c.

We can't yet eliminate suser() due to some cases in the KAME code where
a privilege check is performed and then used in many different deferred
paths.  Do, however, move those prototypes to priv.h.

Reviewed by:	csjp
Obtained from:	TrustedBSD Project
2007-06-12 00:12:01 +00:00
Konstantin Belousov
9e223287c0 Revert UF_OPENING workaround for CURRENT.
Change the VOP_OPEN(), vn_open() vnode operation and d_fdopen() cdev operation
argument from being file descriptor index into the pointer to struct file.

Proposed and reviewed by:	jhb
Reviewed by:	daichi (unionfs)
Approved by:	re (kensmith)
2007-05-31 11:51:53 +00:00
Robert Watson
305759909e Rename mac*devfsdirent*() to mac*devfs*() to synchronize with SEDarwin,
where similar data structures exist to support devfs and the MAC
Framework, but are named differently.

Obtained from:	TrustedBSD Project
Sponsored by:	SPARTA, Inc.
2007-04-23 13:36:54 +00:00
Tom Rhodes
164554dec4 In some cases, like whenever devfs file times are zero, the fix(aa) will not
be applied to dev entries.  This leaves us with file times like "Jan 1 1970."
Work around this problem by replacing the tv_sec == 0 check with a
<= 3600 check.  It's doubtful anyone will be booting within an hour of the
Epoch, let alone care about a few seconds worth of nonzero timestamps.  It's
a hackish work around, but it does work and I have not experienced any
negatives in my testing.

Discussed with:	bde
"Ok with me:	phk
2007-04-20 01:47:05 +00:00
Robert Watson
5e3f7694b1 Replace custom file descriptor array sleep lock constructed using a mutex
and flags with an sxlock.  This leads to a significant and measurable
performance improvement as a result of access to shared locking for
frequent lookup operations, reduced general overhead, and reduced overhead
in the event of contention.  All of these are imported for threaded
applications where simultaneous access to a shared file descriptor array
occurs frequently.  Kris has reported 2x-4x transaction rate improvements
on 8-core MySQL benchmarks; smaller improvements can be expected for many
workloads as a result of reduced overhead.

- Generally eliminate the distinction between "fast" and regular
  acquisisition of the filedesc lock; the plan is that they will now all
  be fast.  Change all locking instances to either shared or exclusive
  locks.

- Correct a bug (pointed out by kib) in fdfree() where previously msleep()
  was called without the mutex held; sx_sleep() is now always called with
  the sxlock held exclusively.

- Universally hold the struct file lock over changes to struct file,
  rather than the filedesc lock or no lock.  Always update the f_ops
  field last. A further memory barrier is required here in the future
  (discussed with jhb).

- Improve locking and reference management in linux_at(), which fails to
  properly acquire vnode references before using vnode pointers.  Annotate
  improper use of vn_fullpath(), which will be replaced at a future date.

In fcntl(), we conservatively acquire an exclusive lock, even though in
some cases a shared lock may be sufficient, which should be revisited.
The dropping of the filedesc lock in fdgrowtable() is no longer required
as the sxlock can be held over the sleep operation; we should consider
removing that (pointed out by attilio).

Tested by:	kris
Discussed with:	jhb, kris, attilio, jeff
2007-04-04 09:11:34 +00:00
Kris Kennaway
6455de0029 Annotate that this giant acqusition is dependent on tty locking. 2007-03-26 21:56:46 +00:00
Tor Egge
61b9d89ff0 Make insmntque() externally visibile and allow it to fail (e.g. during
late stages of unmount).  On failure, the vnode is recycled.

Add insmntque1(), to allow for file system specific cleanup when
recycling vnode on failure.

Change getnewvnode() to no longer call insmntque().  Previously,
embryonic vnodes were put onto the list of vnode belonging to a file
system, which is unsafe for a file system marked MPSAFE.

Change vfs_hash_insert() to no longer lock the vnode.  The caller now
has that responsibility.

Change most file systems to lock the vnode and call insmntque() or
insmntque1() after a new vnode has been sufficiently setup.  Handle
failed insmntque*() calls by propagating errors to callers, possibly
after some file system specific cleanup.

Approved by:	re (kensmith)
Reviewed by:	kib
In collaboration with:	kib
2007-03-13 01:50:27 +00:00
Robert Watson
acd3428b7d Sweep kernel replacing suser(9) calls with priv(9) calls, assigning
specific privilege names to a broad range of privileges.  These may
require some future tweaking.

Sponsored by:           nCircle Network Security, Inc.
Obtained from:          TrustedBSD Project
Discussed on:           arch@
Reviewed (at least in part) by: mlaier, jmg, pjd, bde, ceri,
                        Alex Lyashkov <umka at sevcity dot net>,
                        Skip Ford <skip dot ford at verizon dot net>,
                        Antoine Brodin <antoine dot brodin at laposte dot net>
2006-11-06 13:42:10 +00:00
Robert Watson
aed5570872 Complete break-out of sys/sys/mac.h into sys/security/mac/mac_framework.h
begun with a repo-copy of mac.h to mac_framework.h.  sys/mac.h now
contains the userspace and user<->kernel API and definitions, with all
in-kernel interfaces moved to mac_framework.h, which is now included
across most of the kernel instead.

This change is the first step in a larger cleanup and sweep of MAC
Framework interfaces in the kernel, and will not be MFC'd.

Obtained from:	TrustedBSD Project
Sponsored by:	SPARTA
2006-10-22 11:52:19 +00:00
Konstantin Belousov
16f50bcd80 Update the access and modification times for dev while still holding
thread reference on it.

Reviewed by:	tegge
Approved by:	pjd (mentor)
2006-10-20 08:03:42 +00:00
Konstantin Belousov
1663075c64 Fix the race between devfs_fp_check and devfs_reclaim. Derefence the
vnode' v_rdev and increment the dev threadcount , as well as clear it
(in devfs_reclaim) under the dev_lock().

Reviewed by:	tegge
Approved by:	pjd (mentor)
2006-10-20 07:59:50 +00:00
Konstantin Belousov
828d6d12da Properly lock the vnode around vgone() calls.
Unlock the vnode in devfs_close() while calling into the driver d_close()
routine.

devfs_revoke() changes by:	ups
Reviewed and bugfixes by:	tegge
Tested by:	mbr, Peter Holm
Approved by:	pjd (mentor)
MFC after:	1 week
2006-10-18 11:17:14 +00:00
Tor Egge
5da56ddb21 Use mount interlock to protect all changes to mnt_flag and mnt_kern_flag.
This eliminates a race where MNT_UPDATE flag could be lost when nmount()
raced against sync(), sync_fsync() or quotactl().
2006-09-26 04:12:49 +00:00
Konstantin Belousov
af72db7175 Fix the bug in rev. 1.134. In devfs_allocv_drop_refs(), when not_found == 2
and drop_dm_lock is true, no unlocking shall be attempted. The lock is
already dropped and memory is freed.

Found with:	Coverity Prevent(tm)
CID:	1536
Approved by:	pjd (mentor)
2006-09-19 14:03:02 +00:00
Konstantin Belousov
e7f9b74438 Resolve the devfs deadlock caused by LOR between devfs_mount->dm_lock and
vnode lock in devfs_allocv. Do this by temporary dropping dm_lock around
vnode locking.

For safe operation, add hold counters for both devfs_mount and devfs_dirent,
and DE_DOOMED flag for devfs_dirent. The facilities allow to continue after
dropping of the dm_lock, by making sure that referenced memory does not
disappear.

Reviewed by:	tegge
Tested by:	kris
Approved by:	kan (mentor)
PR:		kern/102335
2006-09-18 13:23:08 +00:00
Poul-Henning Kamp
9c499ad92f Remove the NDEVFSINO and NDEVFSOVERFLOW options which no longer exists in
DEVFS.

Remove the opt_devfs.h file now that it is empty.
2006-07-17 09:07:02 +00:00
Stephan Uphoff
56eeb277cb Add vnode interlocking to devfs.
This prevents race conditions that can cause pagefaults or devfs
to use arbitrary vnodes.

MFC after:	1 week
2006-07-12 20:25:35 +00:00
Robert Watson
2551d4f66e Remove now unneeded opt_mac.h and mac.h includes.
MFC after:	3 days
2006-07-06 13:24:22 +00:00
Robert Watson
83ff52a7f3 Use #include "", not #include <> for opt_foo.h.
MFC after:	3 days
2006-07-06 13:22:08 +00:00
Pawel Jakub Dawidek
00a480ac5c Remove unused prototypes. 2006-04-12 12:17:29 +00:00
Jeff Roberson
23b77994f2 - Add a bogus vhold/vdrop around vgone() in devfs_revoke. Without this
the vnode is never recycled.  It is bogus because the reference really
   should be associated with the devfs dirent.
2006-03-31 23:37:29 +00:00
Jeff Roberson
f50b03bfd6 - We must hold a reference to a vnode before calling vgone() otherwise
it may not be removed from the freelist.

MFC After:	1 week
Found by:	kris
2006-02-22 09:05:40 +00:00
Jeff Roberson
3b77d80cdd - Remove a stale comment. This function was rewritten to be SMP safe some
time ago.

Sponsored by:	Isilon Systems, Inc.
2006-01-30 08:24:14 +00:00
Robert Watson
8f0d99d790 When returning EIO from DEVFSIO_RADD ioctl, drop the exclusive rule
lock.  Otherwise the system comes to a rather sudden and grinding
halt.

MFC after:	1 week
2006-01-03 09:49:10 +00:00
Doug White
16e35dcc39 This is a workaround for a complicated issue involving VFS cookies and devfs.
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
2005-11-09 22:03:50 +00:00
Poul-Henning Kamp
3b72f38b5e Use correct cirteria for determining which directory entries we can
purge right away and which we merely can hide.

Beaten into my skull by:	kris
2005-10-18 20:21:25 +00:00
Poul-Henning Kamp
e515ee7832 Make rule zero really magical, that way we don't have to do anything
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.
2005-09-24 07:03:09 +00:00
Poul-Henning Kamp
e606a3c63e Rewamp DEVFS internals pretty severely [1].
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.
2005-09-19 19:56:48 +00:00
Poul-Henning Kamp
59307b0dfe Don't attempt to recurse lockmgr, it doesn't like it. 2005-09-15 21:16:43 +00:00
Poul-Henning Kamp
214c8ff0e4 Various minor polishing. 2005-09-15 10:28:19 +00:00