Commit Graph

739 Commits

Author SHA1 Message Date
Attilio Rao
59d4932531 Decontextualize vfs_busy(), vfs_unbusy() and vfs_mount_alloc() functions.
Manpages are updated accordingly.

Tested by:	Diego Sardina <siarodx at gmail dot com>
2008-08-31 14:26:08 +00:00
Attilio Rao
0359a12ead Decontextualize the couplet VOP_GETATTR / VOP_SETATTR as the passed thread
was always curthread and totally unuseful.

Tested by: Giovanni Trematerra <giovanni dot trematerra at gmail dot com>
2008-08-28 15:23:18 +00:00
Konstantin Belousov
a888d54d39 Introduce the VV_FORCEINSMQ vnode flag. It instructs the insmnque() function
to ignore the unmounting and forces insertion of the vnode into the mount
vnode list.

Change insmntque() to fail when forced unmount is in progress and
VV_FORCEINSMQ is not specified.

Add an assertion to the insmntque(), requiring the vnode to be
exclusively locked for mp-safe filesystems.

Use the VV_FORCEINSMQ for the creation of the syncvnode.

Tested by:	pho
Reviewed by:	tegge
MFC after:	1 month
2008-08-28 09:08:15 +00:00
Christian S.J. Peron
e451733718 Remove worrying printf warning on bootup when processing vnodes which
have NULL mount-points.  This is the case for special vnodes, such as the
one used in nameiinit() which is used for crossing mount points in lookup()
to avoid  lock ordering issues.

MFC after:	2 weeks
Discussed with:	rwatson, kib
2008-08-24 20:16:44 +00:00
Ed Schouten
e7ea30e404 Remove the use of lbolt from the VFS syncer.
It seems we only use `lbolt' inside the VFS syncer and the TTY layer
now.  Because I'm planning to replace the TTY layer next month, there's
no reason to keep `lbolt' if it's only used in a single thread inside
the kernel.

Because the syncer code wanted to wake up the syncer thread before the
timeout, it called sleepq_remove(). Because we now just use a condvar(9)
with a timeout value of `hz', we can wake it up using cv_broadcast()
without waking up any unrelated threads.

Reviewed by:	phk
2008-07-30 12:39:18 +00:00
Pawel Jakub Dawidek
5573021d78 Assert for exclusive vnode lock in vinactive(), vrecycle() and vgonel()
functions.

Reviewed by:	kib
2008-07-27 11:48:15 +00:00
Pawel Jakub Dawidek
610507ae00 - Move vp test for beeing NULL under IGNORE_LOCK().
- Check if panicstr isn't set, if it is ignore the lock. This helps to avoid
  confusion, because lockmgr is a no-op when panicstr isn't NULL, so
  asserting anything at this point doesn't make sense and can just race with
  other panic.

Discussed with:	kib
2008-07-27 11:46:42 +00:00
Attilio Rao
09400d5abe - Disallow XFS mounting in write mode. The write support never worked really
and there is no need to maintain it.
- Fix vn_get() in order to let it call vget(9) with a valid locking
  request.  vget(9) returns the vnode locked in order to prevent recycling,
  but in this case internal XFS locks alredy prevent it from happening, so
  it is safe to drop the vnode lock before to return by vn_get().
- Add a VNASSERT() in vget(9) in order to catch malformed locking requests.

Discussed with:	kan, kib
Tested by:	Lothar Braun <lothar at lobraun dot de>
2008-07-21 23:01:09 +00:00
Pawel Jakub Dawidek
988f0e193a Be more friendly for DDB pager.
Educated by:	jhb's BSDCan presentation
2008-05-18 21:08:12 +00:00
Attilio Rao
60e2edce55 sync_vnode() has some messy code about locking in order to deal with
mount fs needing Giant to be held when processing bufobjs.
Use a different subqueue for pending workitems on filesystems requiring
Giant. This simplifies the code notably and also reduces the number of
Giant acquisitions (and the whole processing cost).

Suggested by:	jeff
Reviewed by:	kib
Tested by:	pho
2008-05-04 13:54:55 +00:00
Pawel Jakub Dawidek
3800322fe2 Implement 'show mount' command in DDB. Without argument, it prints short
info about all currently mounted file systems. When an address is given
as an argument, prints detailed info about the given mount point.

MFC after:	2 weeks
2008-04-26 13:04:48 +00:00
Konstantin Belousov
12e79a9bbc Allow the vnode zone to return the unused memory. The vnode reference
count is/shall be properly maintained for the long time, and VFS
shall be safe against the vnode memory reclamation.

Proposed by:	jeff
Tested by:	pho
2008-04-24 09:58:33 +00:00
Konstantin Belousov
eab626f110 Move the head of byte-level advisory lock list from the
filesystem-specific vnode data to the struct vnode. Provide the
default implementation for the vop_advlock and vop_advlockasync.
Purge the locks on the vnode reclaim by using the lf_purgelocks().
The default implementation is augmented for the nfs and smbfs.
In the nfs_advlock, push the Giant inside the nfs_dolock.

Before the change, the vop_advlock and vop_advlockasync have taken the
unlocked vnode and dereferenced the fs-private inode data, racing with
with the vnode reclamation due to forced unmount. Now, the vop_getattr
under the shared vnode lock is used to obtain the inode size, and
later, in the lf_advlockasync, after locking the vnode interlock, the
VI_DOOMED flag is checked to prevent an operation on the doomed vnode.

The implementation of the lf_purgelocks() is submitted by dfr.

Reported by:	kris
Tested by:	kris, pho
Discussed with:	jeff, dfr
MFC after:	2 weeks
2008-04-16 11:33:32 +00:00
Jeff Roberson
1fd9b6a577 - Destroy the bo mtx when the vnode is destroyed. 2008-04-02 10:40:03 +00:00
Attilio Rao
71072af500 b_waiters cannot be adequately protected by the interlock because it is
dropped after the call to lockmgr() so just revert this approach using
something similar to the precedent one:
BUF_LOCKWAITERS() just checks if there are waiters (not the actual number
of them) and it is based on newly introduced lockmgr_waiters() which
returns if the lockmgr has waiters or not. The name has been choosen
differently by old lockwaiters() in order to not confuse them.

KPI results enriched by this commit so __FreeBSD_version bumping and
manpage update will be happening soon.
'struct buf' also changes, so kernel ABI is disturbed.

Bug found by:	jeff
Approved by:	jeff, kib
2008-03-28 12:30:12 +00:00
Jeff Roberson
0ee6cecc9d - Greatly simplify vget() by removing the guarantee that any new
references to a vnode with VI_OWEINACT set will force the vinactive()
   call.  The kernel makes no guarantees about which reference was the
   last to close a file or when the actual inactive processing will
   happen.  The previous code was designed to preserve existing semantics
   in the face of shared locks, however, this was unnecessary.

Discussed with:	mckusick
2008-03-24 04:22:58 +00:00
Jeff Roberson
e6b2545b3b - Only return 1 from sync_vnode() in cases where the vnode is still
at the head of the sync list.  This prevents sched_sync() from
   re-queueing a vnode which may have been freed already.

Discussed with:	kib
2008-03-23 01:44:28 +00:00
Jeff Roberson
f6a8cecfc6 - Pass BO_MTX(bo) to lockmgr in vtruncbuf, we don't own the vnode
interlock here anymore.

Reported by:	kris
2008-03-23 01:42:19 +00:00
Jeff Roberson
698b1a6643 - Complete part of the unfinished bufobj work by consistently using
BO_LOCK/UNLOCK/MTX when manipulating the bufobj.
 - Create a new lock in the bufobj to lock bufobj fields independently.
   This leaves the vnode interlock as an 'identity' lock while the bufobj
   is an io lock.  The bufobj lock is ordered before the vnode interlock
   and also before the mnt ilock.
 - Exploit this new lock order to simplify softdep_check_suspend().
 - A few sync related functions are marked with a new XXX to note that
   we may not properly interlock against a non-zero bv_cnt when
   attempting to sync all vnodes on a mountlist.  I do not believe this
   race is important.  If I'm wrong this will make these locations easier
   to find.

Reviewed by:	kib (earlier diff)
Tested by:	kris, pho (earlier diff)
2008-03-22 09:15:16 +00:00
Robert Watson
237fdd787b In keeping with style(9)'s recommendations on macros, use a ';'
after each SYSINIT() macro invocation.  This makes a number of
lightweight C parsers much happier with the FreeBSD kernel
source, including cflow's prcc and lxr.

MFC after:	1 month
Discussed with:	imp, rink
2008-03-16 10:58:09 +00:00
Attilio Rao
7fbfba7bf8 - Handle buffer lock waiters count directly in the buffer cache instead
than rely on the lockmgr support [1]:
  * bump the waiters only if the interlock is held
  * let brelvp() return the waiters count
  * rely on brelvp() instead than BUF_LOCKWAITERS() in order to check
    for the waiters number
- Remove a namespace pollution introduced recently with lockmgr.h
  including lock.h by including lock.h directly in the consumers and
  making it mandatory for using lockmgr.
- Modify flags accepted by lockinit():
  * introduce LK_NOPROFILE which disables lock profiling for the
    specified lockmgr
  * introduce LK_QUIET which disables ktr tracing for the specified
    lockmgr [2]
  * disallow LK_SLEEPFAIL and LK_NOWAIT to be passed there so that it
    can only be used on a per-instance basis
- Remove BUF_LOCKWAITERS() and lockwaiters() as they are no longer
  used

This patch breaks KPI so __FreBSD_version will be bumped and manpages
updated by further commits. Additively, 'struct buf' changes results in
a disturbed ABI also.

[2] Really, currently there is no ktr tracing in the lockmgr, but it
will be added soon.

[1] Submitted by:	kib
Tested by:	pho, Andrea Barberio <insomniac at slackware dot it>
2008-03-01 19:47:50 +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
2433c4883e Conver all explicit instances to VOP_ISLOCKED(arg, NULL) into
VOP_ISLOCKED(arg, curthread). Now, VOP_ISLOCKED() and lockstatus() should
only acquire curthread as argument; this will lead in axing the additional
argument from both functions, making the code cleaner.

Reviewed by: jeff, kib
2008-02-08 21:45:47 +00:00
Attilio Rao
0e9eb108f0 Cleanup lockmgr interface and exported KPI:
- Remove the "thread" argument from the lockmgr() function as it is
  always curthread now
- Axe lockcount() function as it is no longer used
- Axe LOCKMGR_ASSERT() as it is bogus really and no currently used.
  Hopefully this will be soonly replaced by something suitable for it.
- Remove the prototype for dumplockinfo() as the function is no longer
  present

Addictionally:
- Introduce a KASSERT() in lockstatus() in order to let it accept only
  curthread or NULL as they should only be passed
- Do a little bit of style(9) cleanup on lockmgr.h

KPI results heavilly broken by this change, so manpages and
FreeBSD_version will be modified accordingly by further commits.

Tested by: matteo
2008-01-24 12:34:30 +00:00
Attilio Rao
d638e093d6 - Introduce the function lockmgr_recursed() which returns true if the
lockmgr lkp, when held in exclusive mode, is recursed
- Introduce the function BUF_RECURSED() which does the same for bufobj
  locks based on the top of lockmgr_recursed()
- Introduce the function BUF_ISLOCKED() which works like the counterpart
  VOP_ISLOCKED(9), showing the state of lockmgr linked with the bufobj

BUF_RECURSED() and BUF_ISLOCKED() entirely replace the usage of bogus
BUF_REFCNT() in a more explicative and SMP-compliant way.
This allows us to axe out BUF_REFCNT() and leaving the function
lockcount() totally unused in our stock kernel. Further commits will
axe lockcount() as well as part of lockmgr() cleanup.

KPI results, obviously, broken so further commits will update manpages
and freebsd version.

Tested by: kris (on UFS and NFS)
2008-01-19 17:36:23 +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
Robert Watson
c5f1beb02a In "show lockedvnods" DDB command, use db_printf() rather than printf()
so that the results end up in the DDB output stream rather than the
console output stream.

This should likely also be done for the vprint() function it calls.

MFC after:	3 months
2007-12-28 00:47:31 +00:00
Attilio Rao
98e4f2e2bf As LK_EXCLUPGRADE is used in conjuction with LK_NOWAIT, LK_UPGRADE becames
equivalent with this and so operate the switch.

That call is the only one remaining LK_EXCLUPGRADE consumer and removing
it will prepare the ground for LK_EXCLUPGRADE axing and further
lockmgr improvements.

Discussed with: jeff, ups
2007-12-27 20:52:05 +00:00
Robert Watson
3de213cc00 Add a new 'why' argument to kdb_enter(), and a set of constants to use
for that argument.  This will allow DDB to detect the broad category of
reason why the debugger has been entered, which it can use for the
purposes of deciding which DDB script to run.

Assign approximate why values to all current consumers of the
kdb_enter() interface.
2007-12-25 17:52:02 +00:00
Konstantin Belousov
973bdaa06f Use curthread instead of the FIRST_THREAD_IN_PROC for vnlru and syncer,
when applicable.

Aquire Giant slightly later for vnlru.

In the syncer, aquire the Giant only when a vnode belongs to the
non-MPsafe fs.

In both speedup_syncer() and syncer_shutdown(), remove the syncer thread from
the lbolt sleep queue after the syncer state is modified, not before.

Herded by:	attilio
Tested by:	Peter Holm
Reviewed by:	ups
MFC after:	1 week
2007-12-05 09:34:04 +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
Julian Elischer
3745c395ec Rename the kthread_xxx (e.g. kthread_create()) calls
to kproc_xxx as they actually make whole processes.
Thos makes way for us to add REAL kthread_create() and friends
that actually make theads. it turns out that most of these
calls actually end up being moved back to the thread version
when it's added. but we need to make this cosmetic change first.

I'd LOVE to do this rename in 7.0  so that we can eventually MFC the
new kthread_xxx() calls.
2007-10-20 23:23:23 +00:00
Konstantin Belousov
245b204491 When restoring the mount after umount failed, the MNTK_UNMOUNT flag
prevents insmntque() from placing reallocated syncer vnode on mount
list, that causes panic in vfs_allocate_syncvnode().

Introduce MNTK_NOINSMNTQ flag, that marks the period when instmntque is
not allowed to success, instead of MNTK_UNMOUNT. The MNTK_NOINSMNTQ is
set and cleared simultaneously with MNTK_UNMOUNT, except on umount error
path, where it is cleaned just before the syncer vnode is going to be
allocated.

Reported by:	Peter Jeremy <peterjeremy optushome com au>
Suggested by:	tegge
Approved by:	re (rwatson)
2007-09-12 16:31:32 +00:00
Pawel Jakub Dawidek
354eb80141 Improve vn_printf() by:
- adding missing vnode flags,
- printing unknown flags as numbers,
- using strlcat() instead of strcat().

Approved by:	re (bmah)
2007-08-13 21:23:30 +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
Attilio Rao
2feb50bf7d Revert VMCNT_* operations introduction.
Probabilly, a general approach is not the better solution here, so we should
solve the sched_lock protection problems separately.

Requested by: alc
Approved by: jeff (mentor)
2007-05-31 22:52:15 +00:00
Robert Watson
e1e8f51b85 Universally adopt most conventional spelling of acquire. 2007-05-27 20:50:23 +00:00
Konstantin Belousov
d413d21071 Since renaming of vop_lock to _vop_lock, pre- and post-condition
function calls are no more generated for vop_lock.
Rename _vop_lock to vop_lock1 to satisfy tools/vnode_if.awk assumption
about vop naming conventions. This restores pre/post-condition calls.
2007-05-18 13:02:13 +00:00
Jeff Roberson
222d01951f - define and use VMCNT_{GET,SET,ADD,SUB,PTR} macros for manipulating
vmcnts.  This can be used to abstract away pcpu details but also changes
   to use atomics for all counters now.  This means sched lock is no longer
   responsible for protecting counts in the switch routines.

Contributed by:		Attilio Rao <attilio@FreeBSD.org>
2007-05-18 07:10:50 +00:00
Pawel Jakub Dawidek
24b0502ee0 Fix jails and jail-friendly file systems handling:
- We need to allow for PRIV_VFS_MOUNT_OWNER inside a jail.
- Move security checks to vfs_suser() and deny unmounting and updating
  for jailed root from different jails, etc.

OK'ed by:	rwatson
2007-04-13 23:54:22 +00:00
Pawel Jakub Dawidek
6bc3ab2574 When we are running low on vnodes, there is currently no way to ask other
subsystems to release some vnodes. Implement backpressure based on
vfs_lowvnodes event (similar to vm_lowmem for memory).
2007-04-13 08:38:48 +00:00
Pawel Jakub Dawidek
08be819487 Minor style cleanups (mostly removal of trailing whitespaces). 2007-04-10 15:29:37 +00:00
Pawel Jakub Dawidek
21ff8c6715 Correct typos. 2007-04-10 15:22:40 +00:00
Pawel Jakub Dawidek
def72fbba1 Now that the vdropl() function is public, assert that the vnode interlock
is held.
2007-04-01 10:45:32 +00:00
Dag-Erling Smørgrav
e6534b36d8 Make vdropl() public; zfs needs it. There is also plenty of existing
file system code (mostly *_reclaim()) which look like this:

    VOP_LOCK(vp);
    /* examine vp */
    VOP_UNLOCK(vp);
    vdrop(vp);

This can now be rewritten to:

    VOP_LOCK(vp);
    /* examine vp */
    vdropl(vp); /* will unlock vp */

MFC after:	1 week
2007-03-31 23:57:17 +00:00
Marcel Moolenaar
f3ea971bf0 PowerPC is the only architecture with mpsafe_vfs=0. This is now
broken. Rudimentary tests show that PowerPC can run with
mpsafe_vfs=1. Make it so...
2007-03-27 05:29:41 +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
Kip Macy
2f6a774be4 change vop_lock handling to allowing tracking of callers' file and line for
acquisition of lockmgr locks

Approved by: scottl (standing in for mentor rwatson)
2006-11-13 05:51:22 +00:00
John Baldwin
6b8de13ab4 Simplify operations with sync_mtx in sched_sync():
- Don't drop the lock just to reacquire it again to check rushjob, this
  only wastes time.
- Use msleep() to drop the mutex while sleeping instead of explicitly
  unlocking around tsleep.

Reviewed by:	pjd
2006-11-07 19:45:05 +00:00