Commit Graph

156826 Commits

Author SHA1 Message Date
Trond Myklebust
976a6f921c Merge branch 'patches_cel-for-2.6.32' into nfs-for-2.6.32 2009-08-10 17:45:50 -04:00
Magnus Damm
651b1f125c PM / Driver Core: Kill dev_pm_ops platform warning for now
Commit 783ea7d4ee
(Driver Core: Rework platform suspend/resume, print warning)
added a warning message printed for platform drivers that use the
legacy PM callbacks rather than struct dev_pm_ops.  Unfortunately,
this resulted in some confusion and made some people try to convert
drivers by replacing the old callbacks with struct dev_pm_ops in
automatic way, which generally is not a good idea.

Remove the platform device runtime dev_pm_ops warning for now,
because it's annoying to users and it's not really necessary right
now.

[rjw: Modified the changelog to be more informative.]

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2009-08-10 23:41:18 +02:00
Linus Torvalds
85dfd81dc5 pty: fix data loss when stopped (^S/^Q)
Commit d945cb9cc ("pty: Rework the pty layer to use the normal buffering
logic") dropped the test for 'tty->stopped' in pty_write_room(), which
then causes the n_tty line discipline thing to not throttle the data
properly when the tty is stopped.

So instead of pausing the write due to the tty being stopped, the ldisc
layer would go ahead and push it down to the pty.  The pty write()
routine would then refuse to take the data (because it _did_ check
'stopped'), and the data wouldn't actually be written.

This whole stopped test should eventually be moved into the tty ldisc
layer rather than have low-level tty drivers care about these things,
but right now the fix is to just re-instate the missing pty 'stopped'
handling.

Reported-and-tested-by: Artur Skawina <art.08.09@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-08-10 13:31:18 -07:00
Jan Kara
b409d7a0ab ocfs2: Fix possible deadlock when extending quota file
In OCFS2, allocator locks rank above transaction start. Thus we
cannot extend quota file from inside a transaction less we could
deadlock.

We solve the problem by starting transaction not already in
ocfs2_acquire_dquot() but only in ocfs2_local_read_dquot() and
ocfs2_global_read_dquot() and we allocate blocks to quota files before starting
the transaction.  In case we crash, quota files will just have a few blocks
more but that's no problem since we just use them next time we extend the
quota file.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
2009-08-10 12:20:22 -07:00
Shunichi Fuji
3e03bbeac5 x86: Add reboot quirk for every 5 series MacBook/Pro
Reboot does not work on my MacBook Pro 13 inch (MacBookPro5,5)
too. It seems all unibody MacBook and MacBookPro require
PCI reboot handling, i guess.

Following model/machine ID list shows unibody MacBook/Pro have
the 5 series of model number:

   http://www.everymac.com/systems/by_capability/macs-by-machine-model-machine-id.html

Signed-off-by: Shunichi Fuji <palglowr@gmail.com>
Cc: Ozan Çağlayan <ozan@pardus.org.tr>
LKML-Reference: <30046e3b0908101134p6487ddbftd8776e4ddef204be@mail.gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-10 20:59:42 +02:00
Linus Torvalds
d00aa6695b Merge branch 'perfcounters-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perfcounters-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (27 commits)
  perf_counter: Zero dead bytes from ftrace raw samples size alignment
  perf_counter: Subtract the buffer size field from the event record size
  perf_counter: Require CAP_SYS_ADMIN for raw tracepoint data
  perf_counter: Correct PERF_SAMPLE_RAW output
  perf tools: callchain: Fix bad rounding of minimum rate
  perf_counter tools: Fix libbfd detection for systems with libz dependency
  perf: "Longum est iter per praecepta, breve et efficax per exempla"
  perf_counter: Fix a race on perf_counter_ctx
  perf_counter: Fix tracepoint sampling to be part of generic sampling
  perf_counter: Work around gcc warning by initializing tracepoint record unconditionally
  perf tools: callchain: Fix sum of percentages to be 100% by displaying amount of ignored chains in fractal mode
  perf tools: callchain: Fix 'perf report' display to be callchain by default
  perf tools: callchain: Fix spurious 'perf report' warnings: ignore empty callchains
  perf record: Fix the -A UI for empty or non-existent perf.data
  perf util: Fix do_read() to fail on EOF instead of busy-looping
  perf list: Fix the output to not include tracepoints without an id
  perf_counter/powerpc: Fix oops on cpus without perf_counter hardware support
  perf stat: Fix tool option consistency: rename -S/--scale to -c/--scale
  perf report: Add debug help for the finding of symbol bugs - show the symtab origin (DSO, build-id, kernel, etc)
  perf report: Fix per task mult-counter stat reporting
  ...
2009-08-10 11:48:51 -07:00
Darren Hart
392741e0a4 futex: Fix handling of bad requeue syscall pairing
If futex_requeue(requeue_pi=1) finds a futex_q that was created by a call
other the futex_wait_requeue_pi(), the q.rt_waiter may be null.  If so,
this will result in an oops from the following call graph:

futex_requeue()
  rt_mutex_start_proxy_lock()
    task_blocks_on_rt_mutex()
      waiter->task dereference
        OOPS

We currently WARN_ON() if this is detected, clearly this is inadequate.
If we detect a mispairing in futex_requeue(), bail out, seding -EINVAL to
user-space.

V2: Fix parenthesis warnings.

Signed-off-by: Darren Hart <dvhltc@us.ibm.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: John Kacur <jkacur@redhat.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Dinakar Guniguntala <dino@in.ibm.com>
Cc: John Stultz <johnstul@linux.vnet.ibm.com>
LKML-Reference: <4A7CA8C0.7010809@us.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-10 20:38:11 +02:00
Linus Torvalds
cec36911b5 Merge branch 'irq-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'irq-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86/irq: Fix move_irq_desc() for nodes without ram
2009-08-10 11:21:13 -07:00
Linus Torvalds
a3263969b0 Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: Fix serialization in pit_expect_msb()
2009-08-10 11:11:40 -07:00
Linus Torvalds
9b8f013a83 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6:
  PCI hotplug: SGI hotplug: do not use hotplug_slot_attr
  PCI hotplug: SGI hotplug: fix build failure
2009-08-10 11:00:37 -07:00
Linus Torvalds
b6e61eef4f x86: Fix serialization in pit_expect_msb()
Wei Chong Tan reported a fast-PIT-calibration corner-case:

| pit_expect_msb() is vulnerable to SMI disturbance corner case
| in some platforms which causes /proc/cpuinfo to show wrong
| CPU MHz value when quick_pit_calibrate() jumps to success
| section.

I think that the real issue isn't even an SMI - but the fact
that in the very last iteration of the loop, there's no
serializing instruction _after_ the last 'rdtsc'. So even in
the absense of SMI's, we do have a situation where the cycle
counter was read without proper serialization.

The last check should be done outside the outer loop, since
_inside_ the outer loop, we'll be testing that the PIT has
the right MSB value has the right value in the next iteration.

So only the _last_ iteration is special, because that's the one
that will not check the PIT MSB value any more, and because the
final 'get_cycles()' isn't serialized.

In other words:

 - I'd like to move the PIT MSB check to after the last
   iteration, rather than in every iteration

 - I think we should comment on the fact that it's also a
   serializing instruction and so 'fences in' the TSC read.

Here's a suggested replacement.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Reported-by: "Tan, Wei Chong" <wei.chong.tan@intel.com>
Tested-by: "Tan, Wei Chong" <wei.chong.tan@intel.com>
LKML-Reference: <B28277FD4E0F9247A3D55704C440A140D5D683F3@pgsmsx504.gar.corp.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-10 19:56:57 +02:00
Linus Torvalds
9bcf73f482 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6:
  mm_for_maps: take ->cred_guard_mutex to fix the race with exec
  mm_for_maps: shift down_read(mmap_sem) to the caller
  mm_for_maps: simplify, use ptrace_may_access()
2009-08-10 09:00:47 -07:00
Linus Torvalds
2c661a669b Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
  powerpc/dma: pci_set_dma_mask() shouldn't fail if mask fits in RAM
2009-08-10 08:59:56 -07:00
Jaswinder Singh Rajput
04e35357e2 MN10300: includecheck fix: mn10300, pci.h
Fix the following 'make includecheck' warning:

  arch/mn10300/include/asm/pci.h: linux/mm.h is included more than once.

Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-08-10 08:54:27 -07:00
Figo.zhang
5e2f89b5d5 mempool.c: clean up type-casting
clean up type-casting twice.  "size_t" is typedef as "unsigned long" in
64-bit system, and "unsigned int" in 32-bit system, and the intermediate
cast to 'long' is pointless.

Signed-off-by: Figo.zhang <figo1802@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-08-10 08:31:16 -07:00
Ryusuke Konishi
1392e3b333 documentation: register ioctl entry of nilfs2
This will register the ioctl range used by nilfs2 file system to the
table listed in Documentation/ioctl/ioctl-number.txt.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-08-10 08:30:11 -07:00
Frederic Weisbecker
1853db0e02 perf_counter: Zero dead bytes from ftrace raw samples size alignment
After aligning the ftrace raw samples, there are dead bytes storing
random data from the stack. We don't want to leak these to userspace,
then zero these out.

Before:

	0x2de88 [0x50]: event: 9
	.
	. ... raw event: size 80 bytes
	.  0000:  09 00 00 00 01 00 50 00 d0 c7 00 81 ff ff ff ff  ......P........
	.  0010:  68 01 00 00 68 01 00 00 2c 00 00 00 00 00 00 00  h...h...,......
	.  0020:  2c 00 00 00 2b 00 01 02 68 01 00 00 68 01 00 00  ,...+...h...h..
	.  0030:  6b 6f 6e 64 65 6d 61 6e 64 2f 30 00 00 00 00 00  kondemand/0....
	.  0040:  68 01 00 00 40 7f 46 81 ff ff ff ff 00 10 1b 7f  h...@.F........
                                                      ^  ^  ^  ^
                                                         Leak

After:

	0x2d318 [0x50]: event: 9
	.
	. ... raw event: size 80 bytes
	.  0000:  09 00 00 00 01 00 50 00 d0 c7 00 81 ff ff ff ff  ......P........
	.  0010:  68 01 00 00 68 01 00 00 68 14 00 00 00 00 00 00  h...h...h......
	.  0020:  2c 00 00 00 2b 00 01 02 68 01 00 00 68 01 00 00  ,...+...h...h..
	.  0030:  6b 6f 6e 64 65 6d 61 6e 64 2f 30 00 00 00 00 00  kondemand/0....
	.  0040:  68 01 00 00 a0 80 46 81 ff ff ff ff 00 00 00 00  h.....F........
                                                      ^  ^  ^  ^
							 Fixed

Reported-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <1249915116-5210-1-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
2009-08-10 16:51:19 +02:00
Frederic Weisbecker
304703aba3 perf_counter: Subtract the buffer size field from the event record size
We compute the perf raw sample size by aligning the raw ftrace
event size plus the buffer size field itself. We do that
instead of aligning only the perf raw sample size, so that we
might economize some in some cases.

But this buffer size field is not stored in the perf raw
sample, we must then substract its size from the buffer once we
computed the alignment unless we may get a useless u32 field in
the buffer.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <20090810141129.GA5124@nowhere>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-10 16:18:50 +02:00
Dinakar Guniguntala
4dc88029fd futex: Fix compat_futex to be same as futex for REQUEUE_PI
Need to add the REQUEUE_PI checks to the compat_sys_futex API
as well to ensure 32 bit requeue's work fine on a 64 bit
system. Patch is against latest tip

Signed-off-by: Dinakar Guniguntala <dino@in.ibm.com>
Cc: Darren Hart <dvhltc@us.ibm.com>
LKML-Reference: <20090810130142.GA23619@in.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-10 15:41:12 +02:00
Bartlomiej Zolnierkiewicz
e576e05a73 nfs: remove superfluous BUG_ON()s
Subject: [PATCH] nfs: remove superfluous BUG_ON()s

Remove duplicated BUG_ON()s from nfs[4]_create_server()
(we make the same checks earlier in both functions).

This takes care of the following entries from Dan's list:

fs/nfs/client.c +1078 nfs_create_server(47) warning: variable derefenced before check 'server->nfs_client'
fs/nfs/client.c +1079 nfs_create_server(48) warning: variable derefenced before check 'server->nfs_client->rpc_ops'
fs/nfs/client.c +1363 nfs4_create_server(43) warning: variable derefenced before check 'server->nfs_client'
fs/nfs/client.c +1364 nfs4_create_server(44) warning: variable derefenced before check 'server->nfs_

Reported-by: Dan Carpenter <error27@gmail.com>
Cc: corbet@lwn.net
Cc: eteo@redhat.com
Cc: Julia Lawall <julia@diku.dk>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2009-08-10 08:54:16 -04:00
Peter Staubach
38c73044f5 NFS: read-modify-write page updating
Hi.

I have a proposal for possibly resolving this issue.

I believe that this situation occurs due to the way that the
Linux NFS client handles writes which modify partial pages.

The Linux NFS client handles partial page modifications by
allocating a page from the page cache, copying the data from
the user level into the page, and then keeping track of the
offset and length of the modified portions of the page.  The
page is not marked as up to date because there are portions
of the page which do not contain valid file contents.

When a read call comes in for a portion of the page, the
contents of the page must be read in the from the server.
However, since the page may already contain some modified
data, that modified data must be written to the server
before the file contents can be read back in the from server.
And, since the writing and reading can not be done atomically,
the data must be written and committed to stable storage on
the server for safety purposes.  This means either a
FILE_SYNC WRITE or a UNSTABLE WRITE followed by a COMMIT.
This has been discussed at length previously.

This algorithm could be described as modify-write-read.  It
is most efficient when the application only updates pages
and does not read them.

My proposed solution is to add a heuristic to decide whether
to do this modify-write-read algorithm or switch to a read-
modify-write algorithm when initially allocating the page
in the write system call path.  The heuristic uses the modes
that the file was opened with, the offset in the page to
read from, and the size of the region to read.

If the file was opened for reading in addition to writing
and the page would not be filled completely with data from
the user level, then read in the old contents of the page
and mark it as Uptodate before copying in the new data.  If
the page would be completely filled with data from the user
level, then there would be no reason to read in the old
contents because they would just be copied over.

This would optimize for applications which randomly access
and update portions of files.  The linkage editor for the
C compiler is an example of such a thing.

I tested the attached patch by using rpmbuild to build the
current Fedora rawhide kernel.  The kernel without the
patch generated about 269,500 WRITE requests.  The modified
kernel containing the patch generated about 261,000 WRITE
requests.  Thus, about 8,500 fewer WRITE requests were
generated.  I suspect that many of these additional
WRITE requests were probably FILE_SYNC requests to WRITE
a single page, but I didn't test this theory.

The difference between this patch and the previous one was
to remove the unneeded PageDirty() test.  I then retested to
ensure that the resulting system continued to behave as
desired.

	Thanx...

		ps

Signed-off-by: Peter Staubach <staubach@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2009-08-10 08:54:16 -04:00
Trond Myklebust
074cc1deec NFS: Add a ->migratepage() aop for NFS
Make NFS a bit more friendly to NUMA and memory hot removal...

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2009-08-10 08:54:13 -04:00
Peter Zijlstra
2fc391112f locking, sched: Give waitqueue spinlocks their own lockdep classes
Give waitqueue spinlocks their own lockdep classes when they
are initialised from init_waitqueue_head().  This means that
struct wait_queue::func functions can operate other waitqueues.

This is used by CacheFiles to catch the page from a backing fs
being unlocked and to wake up another thread to take a copy of
it.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Takashi Iwai <tiwai@suse.de>
Cc: linux-cachefs@redhat.com
Cc: torvalds@osdl.org
Cc: akpm@linux-foundation.org
LKML-Reference: <20090810113305.17284.81508.stgit@warthog.procyon.org.uk>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-10 14:43:09 +02:00
Oleg Nesterov
704b836cbf mm_for_maps: take ->cred_guard_mutex to fix the race with exec
The problem is minor, but without ->cred_guard_mutex held we can race
with exec() and get the new ->mm but check old creds.

Now we do not need to re-check task->mm after ptrace_may_access(), it
can't be changed to the new mm under us.

Strictly speaking, this also fixes another very minor problem. Unless
security check fails or the task exits mm_for_maps() should never
return NULL, the caller should get either old or new ->mm.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
2009-08-10 20:49:26 +10:00
Oleg Nesterov
00f89d2185 mm_for_maps: shift down_read(mmap_sem) to the caller
mm_for_maps() takes ->mmap_sem after security checks, this looks
strange and obfuscates the locking rules. Move this lock to its
single caller, m_start().

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
2009-08-10 20:48:32 +10:00
Oleg Nesterov
13f0feafa6 mm_for_maps: simplify, use ptrace_may_access()
It would be nice to kill __ptrace_may_access(). It requires task_lock(),
but this lock is only needed to read mm->flags in the middle.

Convert mm_for_maps() to use ptrace_may_access(), this also simplifies
the code a little bit.

Also, we do not need to take ->mmap_sem in advance. In fact I think
mm_for_maps() should not play with ->mmap_sem at all, the caller should
take this lock.

With or without this patch, without ->cred_guard_mutex held we can race
with exec() and get the new ->mm but check old creds.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
2009-08-10 20:47:42 +10:00
Takashi Iwai
100d5eb36b ALSA: hda - Add missing vmaster initialization for ALC269
Without the initialization of vmaster NID, the dB information got
confused for ALC269 codec.

Reference: Novell bnc#527361
	https://bugzilla.novell.com/show_bug.cgi?id=527361

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Cc: <stable@kernel.org>
2009-08-10 11:57:05 +02:00
Peter Zijlstra
a4e95fc2cb perf_counter: Require CAP_SYS_ADMIN for raw tracepoint data
Raw tracepoint data contains various kernel internals and
data from other users, so restrict this to CAP_SYS_ADMIN.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1249896452.17467.75.camel@twins>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-10 11:33:09 +02:00
Peter Zijlstra
a044560c3a perf_counter: Correct PERF_SAMPLE_RAW output
PERF_SAMPLE_* output switches should unconditionally output the
correct format, as they are the only way to unambiguously parse
the PERF_EVENT_SAMPLE data.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1249896447.17467.74.camel@twins>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-10 11:33:09 +02:00
Darren Hart
beda2c7ea2 futex: Update futex_q lock_ptr on requeue proxy lock
futex_requeue() can acquire the lock on behalf of a waiter
early on or during the requeue loop if it is uncontended or in
the event of a lock steal or owner died. On wakeup, the waiter
(in futex_wait_requeue_pi()) cleans up the pi_state owner using
the lock_ptr to protect against concurrent access to the
pi_state. The pi_state is hung off futex_q's on the requeue
target futex hash bucket so the lock_ptr needs to be updated
accordingly.

The problem manifested by triggering the WARN_ON in
lookup_pi_state() about the pid != pi_state->owner->pid.  With
this patch, the pi_state is properly guarded against concurrent
access via the requeue target hb lock.

The astute reviewer may notice that there is a window of time
between when futex_requeue() unlocks the hb locks and when
futex_wait_requeue_pi() will acquire hb2->lock.  During this
time the pi_state and uval are not in sync with the underlying
rtmutex owner (but the uval does indicate there are waiters, so
no atomic changes will occur in userspace).  However, this is
not a problem. Should a contending thread enter
lookup_pi_state() and acquire hb2->lock before the ownership is
fixed up, it will find the pi_state hung off a waiter's
(possibly the pending owner's) futex_q and block on the
rtmutex.  Once futex_wait_requeue_pi() fixes up the owner, it
will also move the pi_state from the old owner's
task->pi_state_list to its own.

v3: Fix plist lock name for application to mainline (rather
    than -rt) Compile tested against tip/v2.6.31-rc5.

Signed-off-by: Darren Hart <dvhltc@us.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Dinakar Guniguntala <dino@in.ibm.com>
Cc: John Stultz <johnstul@linux.vnet.ibm.com>
LKML-Reference: <4A7F4EFF.6090903@us.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-10 11:07:03 +02:00
Benjamin Herrenschmidt
b2f2e8fee3 powerpc/dma: pci_set_dma_mask() shouldn't fail if mask fits in RAM
On an iMac G5, the b43 driver is failing to initialise because trying to
set the dma mask to 30-bit fails. Even though there's only 512MiB of RAM
in the machine anyway:
	https://bugzilla.redhat.com/show_bug.cgi?id=514787

We should probably let it succeed if the available RAM in the system
doesn't exceed the requested limit.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-08-10 16:36:38 +10:00
NeilBrown
c8c00a6915 Remove deadlock potential in md_open
A recent commit:
  commit 449aad3e25

introduced the possibility of an A-B/B-A deadlock between
bd_mutex and reconfig_mutex.

__blkdev_get holds bd_mutex while calling md_open which takes
   reconfig_mutex,
do_md_run is always called with reconfig_mutex held, and it now
   takes bd_mutex in the call the revalidate_disk.

This potential deadlock was not caught by lockdep due to the
use of mutex_lock_interruptible_nexted which was introduced
by
   commit d63a5a74de
do avoid a warning of an impossible deadlock.

It is quite possible to split reconfig_mutex in to two locks.
One protects the array data structures while it is being
reconfigured, the other ensures that an array is never even partially
open while it is being deactivated.
In particular, the second lock prevents an open from completing
between the time when do_md_stop checks if there are any active opens,
and the time when the array is either set read-only, or when ->pers is
set to NULL.  So we can be certain that no IO is in flight as the
array is being destroyed.

So create a new lock, open_mutex, just to ensure exclusion between
'open' and 'stop'.

This avoids the deadlock and also avoids the lockdep warning mentioned
in commit d63a5a74d

Reported-by: "Mike Snitzer" <snitzer@gmail.com>
Reported-by: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-08-10 12:50:52 +10:00
Linus Torvalds
f4b9a98868 Merge branch 'for-linus' of git://git.infradead.org/ubi-2.6
* 'for-linus' of git://git.infradead.org/ubi-2.6:
  UBI: compatible fallback in absense of sequence numbers
  UBI: fix double free on error path
2009-08-09 14:58:34 -07:00
Linus Torvalds
17d11ba149 Merge branch 'kvm-updates/2.6.31' of git://git.kernel.org/pub/scm/virt/kvm/kvm
* 'kvm-updates/2.6.31' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: Avoid redelivery of edge interrupt before next edge
  KVM: MMU: limit rmap chain length
  KVM: ia64: fix build failures due to ia64/unsigned long mismatches
  KVM: Make KVM_HPAGES_PER_HPAGE unsigned long to avoid build error on powerpc
  KVM: fix ack not being delivered when msi present
  KVM: s390: fix wait_queue handling
  KVM: VMX: Fix locking imbalance on emulation failure
  KVM: VMX: Fix locking order in handle_invalid_guest_state
  KVM: MMU: handle n_free_mmu_pages > n_alloc_mmu_pages in kvm_mmu_change_mmu_pages
  KVM: SVM: force new asid on vcpu migration
  KVM: x86: verify MTRR/PAT validity
  KVM: PIT: fix kpit_elapsed division by zero
  KVM: Fix KVM_GET_MSR_INDEX_LIST
2009-08-09 14:58:21 -07:00
Linus Torvalds
fb1ee451e6 Merge branch 'drm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6
* 'drm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6:
  drm/i915: silence vblank warnings
  drm: silence pointless vblank warning.
  drm: When adding probed modes, preserve duplicate mode types
2009-08-09 14:58:09 -07:00
Linus Torvalds
2e9b11afdb Merge branch 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  posix_cpu_timers_exit_group(): Do not use thread_group_cputimer()
2009-08-09 14:57:41 -07:00
Linus Torvalds
95d0ad049c Merge branch 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  perf_counter: Fix/complete ftrace event records sampling
  perf_counter, ftrace: Fix perf_counter integration
  tracing/filters: Always free pred on filter_add_subsystem_pred() failure
  tracing/filters: Don't use pred on alloc failure
  ring-buffer: Fix memleak in ring_buffer_free()
  tracing: Fix recordmcount.pl to handle sections with only weak functions
  ring-buffer: Fix advance of reader in rb_buffer_peek()
  tracing: do not use functions starting with .L in recordmcount.pl
  ring-buffer: do not disable ring buffer on oops_in_progress
  ring-buffer: fix check of try_to_discard result
2009-08-09 14:57:26 -07:00
Linus Torvalds
413dd8768a Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: fix buffer overflow in efi_init()
  x86: Add quirk to make Apple MacBookPro5,1 use reboot=pci
  x86: Fix MSI-X initialization by using online_mask for x2apic target_cpus
  x86: Fix VMI && stack protector
2009-08-09 14:57:09 -07:00
Linus Torvalds
713e3e1875 Merge branch 'core-fixes-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-fixes-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  lockdep: Fix typos in documentation
  lockdep: Fix file mode of lock_stat
  rtmutex: Avoid deadlock in rt_mutex_start_proxy_lock()
2009-08-09 14:56:51 -07:00
Trond Myklebust
8854e82d9a SUNRPC: Add an rpc_pipefs front end for the sunrpc cache code
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2009-08-09 15:14:30 -04:00
Trond Myklebust
173912a6ad SUNRPC: Move procfs-specific stuff out of the generic sunrpc cache code
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2009-08-09 15:14:29 -04:00
Trond Myklebust
bc74b4f5e6 SUNRPC: Allow the cache_detail to specify alternative upcall mechanisms
For events that are rare, such as referral DNS lookups, it makes limited
sense to have a daemon constantly listening for upcalls on a channel. An
alternative in those cases might simply be to run the app that fills the
cache using call_usermodehelper_exec() and friends.

The following patch allows the cache_detail to specify alternative upcall
mechanisms for these particular cases.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2009-08-09 15:14:29 -04:00
Trond Myklebust
da77005f0d SUNRPC: Remove the global temporary write buffer in net/sunrpc/cache.c
While we do want to protect against multiple concurrent readers and writers
on each upcall/downcall pipe, we don't want to limit concurrent reading and
writing to separate caches.

This patch therefore replaces the static buffer 'write_buf', which can only
be used by one writer at a time, with use of the page cache as the
temporary buffer for downcalls. We still fall back to using the the old
global buffer if the downcall is larger than PAGE_CACHE_SIZE, since this is
apparently needed by the SPKM security context initialisation.

It then replaces the use of the global 'queue_io_mutex' with the
inode->i_mutex in cache_read() and cache_write().

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2009-08-09 15:14:28 -04:00
Trond Myklebust
5b7a1b9f92 SUNRPC: Ensure we initialise the cache_detail before creating procfs files
Also ensure that we destroy those files before we destroy the cache_detail.
Otherwise, user processes might attempt to write into uninitialised caches.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2009-08-09 15:14:27 -04:00
Trond Myklebust
2da8ca26c6 NFSD: Clean up the idmapper warning...
What part of 'internal use' is so hard to understand?

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2009-08-09 15:14:26 -04:00
Trond Myklebust
e57aed77ad SUNRPC: One more clean up for rpc_create_client_dir()
In order to allow rpc_pipefs to create directories with different types of
subtrees, it is useful to allow the caller to customise the subtree filling
process.
In order to do so, we separate out the parts which are specific to making
an RPC client directory, and put them in a separate helper, then we convert
the process of filling the directory contents into a callback.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2009-08-09 15:14:26 -04:00
Trond Myklebust
23ac658170 SUNRPC: clean up rpc_setup_pipedir()
There is still a little wart or two there: Since we've already got a
vfsmount, we might as well pass that in to rpc_create_client_dir.
Another point is that if we open code __rpc_lookup_path() here, then we can
avoid looking up the entire parent directory path over and over again: it
doesn't change.

Also get rid of rpc_clnt->cl_pathname, since it has no users...

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2009-08-09 15:14:25 -04:00
Trond Myklebust
7d217caca5 SUNRPC: Replace rpc_client->cl_dentry and cl_mnt, with a cl_path
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2009-08-09 15:14:24 -04:00
Trond Myklebust
7d59d1e865 SUNRPC: Clean up rpc_create_client_dir()
Factor out the code that does lookups from the code that actually creates
the directory.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2009-08-09 15:14:23 -04:00
Trond Myklebust
458adb8ba9 SUNRPC: Rename rpc_mkdir to rpc_create_client_dir()
This reflects the fact that rpc_mkdir() as it stands today, can only create
a RPC client type directory.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2009-08-09 15:14:22 -04:00