Module refcounting is implemented with a per-cpu counter for speed.
However there is a race when tallying the counter where a reference may
be taken by one CPU and released by another.  Reference count summation
may then see the decrement without having seen the previous increment,
leading to lower than expected count.  A module which never has its
actual reference drop below 1 may return a reference count of 0 due to
this race.

Module removal generally runs under stop_machine, which prevents this
race causing bugs due to removal of in-use modules.  However there are
other real bugs in module.c code and driver code (module_refcount is
exported) where the callers do not run under stop_machine.

Fix this by maintaining running per-cpu counters for the number of
module refcount increments and the number of refcount decrements.  The
increments are tallied after the decrements, so any decrement seen will
always have its corresponding increment counted.  The final refcount is
the difference of the total increments and decrements, preventing a
low-refcount from being returned.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-rc-fixes-2.6:
  [SCSI] qla1280: retain firmware for error recovery
  [SCSI] attirbute_container: Initialize sysfs attributes with sysfs_attr_init
  [SCSI] advansys: fix regression with request_firmware change
  [SCSI] qla2xxx: Updated version number to 8.03.02-k2.
  [SCSI] qla2xxx: Prevent sending mbx commands from sysfs during isp reset.
  [SCSI] qla2xxx: Disable MSI on qla24xx chips other than QLA2432.
  [SCSI] qla2xxx: Check to make sure multique and CPU affinity support is not enabled at the same time.
  [SCSI] qla2xxx: Correct vp_idx checking during PORT_UPDATE processing.
  [SCSI] qla2xxx: Honour "Extended BB credits" bit for CNAs.
  [SCSI] scsi_transport_fc: Make sure commands are completed when rport is offline
  [SCSI] libiscsi: Fix recovery slowdown regression

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs:
  9p: saving negative to unsigned char
  9p: return on mutex_lock_interruptible()
  9p: Creating files with names too long should fail with ENAMETOOLONG.
  9p: Make sure we are able to clunk the cached fid on umount
  9p: drop nlink remove
  fs/9p: Clunk the fid resulting from partial walk of the name
  9p: documentation update
  9p: Fix setting of protocol flags in v9fs_session_info structure.

* git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable:
  Btrfs: add check for changed leaves in setup_leaf_for_split
  Btrfs: create snapshot references in same commit as snapshot
  Btrfs: fix small race with delalloc flushing waitqueue's
  Btrfs: use add_to_page_cache_lru, use __page_cache_alloc
  Btrfs: fix chunk allocate size calculation
  Btrfs: kill max_extent mount option
  Btrfs: fail to mount if we have problems reading the block groups
  Btrfs: check btrfs_get_extent return for IS_ERR()
  Btrfs: handle kmalloc() failure in inode lookup ioctl
  Btrfs: dereferencing freed memory
  Btrfs: Simplify num_stripes's calculation logical for __btrfs_alloc_chunk()
  Btrfs: Add error handle for btrfs_search_slot() in btrfs_read_chunk_tree()
  Btrfs: Remove unnecessary finish_wait() in wait_current_trans()
  Btrfs: add NULL check for do_walk_down()
  Btrfs: remove duplicate include in ioctl.c

Fix trivial conflict in fs/btrfs/compression.c due to slab.h include
cleanups.

There have been a number of reports of people seeing the message:
"name_count maxed, losing inode data: dev=00:05, inode=3185"
in dmesg.  These usually lead to people reporting problems to the filesystem
group who are in turn clueless what they mean.

Eventually someone finds me and I explain what is going on and that
these come from the audit system.  The basics of the problem is that the
audit subsystem never expects a single syscall to 'interact' (for some
wish washy meaning of interact) with more than 20 inodes.  But in fact
some operations like loading kernel modules can cause changes to lots of
inodes in debugfs.

There are a couple real fixes being bandied about including removing the
fixed compile time limit of 20 or not auditing changes in debugfs (or
both) but neither are small and obvious so I am not sending them for
immediate inclusion (I hope Al forwards a real solution next devel
window).

In the meantime this patch simply adds 'audit' to the beginning of the
crap message so if a user sees it, they come blame me first and we can
talk about what it means and make sure we understand all of the reasons
it can happen and make sure this gets solved correctly in the long run.
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Saving -EINVAL as unsigned char truncates the high bits and changes it
into 234 instead of -22.  This breaks the test for "if (ret == -EINVAL)"
in parse_opts().
Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

If "err" is -EINTR here the original code calls mutex_unlock() and then
returns, but it should just return directly.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

------------------------------------------------------------------------------
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setup_leaf_for_split needs to drop the path and search again, and has
checks to see if the item we want to split changed size.  But, it misses
the case where the leaf changed and now has enough room for the item
we want to insert.

This adds an extra check to make sure the leaf really needs splitting
before we call btrfs_split_leaf(), which keeps us from trying to split
a leaf with a single item.

btrfs_split_leaf() will blindly split the single item leaf, leaving us
with one good leaf and one empty leaf and then a crash.
Signed-off-by: Chris Mason <chris.mason@oracle.com>

This creates the reference to a new snapshot in the same commit as the
snapshot itself.  This avoids the need for a second commit in order for a
snapshot to be persistent, and also avoids the problem of "leaking" a
new snapshot tree root if the host crashes before the second commit takes
place.

It is not at all clear to me why it wasn't always done this way.  If there
is still a reason for the two-stage {create,finish}_pending_snapshots()
approach I'm missing something!  :)

I've been running this for a couple weeks under pretty heavy usage (a few
snapshots per minute) without obvious problems.
Signed-off-by: Sage Weil <sage@newdream.net>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

Everytime we start a new flushing thread, we init the waitqueue if there isn't a
flushing thread running.  The problem with this is we check
space_info->flushing, which we clear right before doing a wake_up on the
flushing waitqueue, which causes problems if we init the waitqueue in the middle
of clearing the flushing flagh and calling wake_up.  This is hard to hit, but
the code is wrong anyway, so init the flushing/allocating waitqueue when
creating the space info and let it be.  I haven't seen the panic since I've been
using this patch.  Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

Pagecache pages should be allocated with __page_cache_alloc, so they
obey pagecache memory policies.

add_to_page_cache_lru is exported, so it should be used. Benefits over
using a private pagevec: neater code, 128 bytes fewer stack used, percpu
lru ordering is preserved, and finally don't need to flush pagevec
before returning so batching may be shared with other LRU insertions.

Signed-off-by: Nick Piggin <npiggin@suse.de>:
Signed-off-by: Chris Mason <chris.mason@oracle.com>

* 'slabh' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc:
  eeepc-wmi: include slab.h
  staging/otus: include slab.h from usbdrv.h
  percpu: don't implicitly include slab.h from percpu.h
  kmemcheck: Fix build errors due to missing slab.h
  include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
  iwlwifi: don't include iwl-dev.h from iwl-devtrace.h
  x86: don't include slab.h from arch/x86/include/asm/pgtable_32.h

Fix up trivial conflicts in include/linux/percpu.h due to
is_kernel_percpu_address() having been introduced since the slab.h
cleanup with the percpu_up.c splitup.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
  module: add stub for is_module_percpu_address
  percpu, module: implement and use is_kernel/module_percpu_address()
  module: encapsulate percpu handling better and record percpu_size

Fix a memory leak in anon_vma_fork(), where we fail to tear down the
anon_vmas attached to the new VMA in case setting up the new anon_vma
fails.

This bug also has the potential to leave behind anon_vma_chain structs
with pointers to invalid memory.
Reported-by: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: Sripathi Kodi <sripathik@in.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

dcache prune happen on umount. So we cannot mark the client
satus disconnect. That will prevent a 9p call to the server
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

We need to drop the link count on the inode of a sucessfull remove
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

This patch adds documentation for new 9P options introduced in
2.6.34.
Signed-off-by: Sripathi Kodi <sripathik@in.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

This patch fixes a simple bug I left behind in my earlier protocol
negotiation patch.

Thanks,
Sripathi.
Signed-off-by: Sripathi Kodi <sripathik@in.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

eeepc-wmi uses kfree() but doesn't include slab.h.  Include it.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Yong Wang <yong.y.wang@intel.com>

drivers/staging/otus/usbdrv.h users use slab facilities.  Include
linux/slab.h from usbdrv.h.
Signed-off-by: Tejun Heo <tj@kernel.org>

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6:
  sunxvr500: Ignore secondary output PCI devices.
  sparc64: Implement perf_arch_fetch_caller_regs
  sparc64: Update defconfig.
  sparc64: Fix array size reported by vmemmap_populate()
  sparc: Fix regset register window handling.
  drivers/serial/sunsu.c: Correct use after free

Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  perf: Always build the powerpc perf_arch_fetch_caller_regs version
  perf: Always build the stub perf_arch_fetch_caller_regs version
  perf, probe-finder: Build fix on Debian
  perf/scripts: Tuple was set from long in both branches in python_process_event()
  perf: Fix 'perf sched record' deadlock
  perf, x86: Fix callgraphs of 32-bit processes on 64-bit kernels
  perf, x86: Fix AMD hotplug & constraint initialization
  x86: Move notify_cpu_starting() callback to a later stage
  x86,kgdb: Always initialize the hw breakpoint attribute
  perf: Use hot regs with software sched switch/migrate events
  perf: Correctly align perf event tracing buffer

Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  sched: set_cpus_allowed_ptr(): Don't use rq->migration_thread after unlock
  sched: Fix proc_sched_set_task()

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:
  ring-buffer: Add missing unlock
  tracing: Fix lockdep warning in global_clock()

In initial design, walk_page_range() was designed just for walking page
table and it didn't require mmap_sem.  Now, find_vma() etc..  are used
in walk_page_range() and we need mmap_sem around it.

This patch adds mmap_sem around walk_page_range().

Because /proc/<pid>/pagemap's callback routine use put_user(), we have
to get rid of it to do sane fix.

Changelog: 2010/Apr/2
 - fixed start_vaddr and end overflow
Changelog: 2010/Apr/1
 - fixed start_vaddr calculation
 - removed unnecessary cast.
 - removed unnecessary change in smaps.
 - use GFP_TEMPORARY instead of GFP_KERNEL
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Matt Mackall <mpm@selenic.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: San Mehat <san@google.com>
Cc: Brian Swetland <swetland@google.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
[ Fixed kmalloc failure return code as per Matt ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

These just represent the secondary and further heads attached to the
card, and they have different sets of PCI bar registers to map.

So don't try to drive them in the main driver.
Reported-by: Frans van Berckel <fberckel@xs4all.nl>
Tested-by: Frans van Berckel <fberckel@xs4all.nl>
Signed-off-by: David S. Miller <davem@davemloft.net>

We provide regs->tstate, regs->tpc, regs->tnpc and
regs->u_regs[UREG_FP].

regs->tstate is necessary for:

	user_mode()		(via perf_exclude_event())

	perf_misc_flags()	(via perf_prepare_sample())

regs->tpc is necessary for:

	perf_instruction_pointer() (via perf_prepare_sample())

and regs->u_regs[UREG_FP] is necessary for:

	perf_callchain()	(via perf_prepare_sample())

The regs->tnpc value is provided just to be tidy.
Signed-off-by: David S. Miller <davem@davemloft.net>

Signed-off-by: David S. Miller <davem@davemloft.net>

vmemmap_populate() attempts to report the used index and total size of
vmemmap_table, but it wrongly shifts the total size so that it is
always shown as 0.
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

Now that software events use perf_arch_fetch_caller_regs() too, we
need the powerpc version to be always built.

Fixes the following build error:

	(.text+0x3210): undefined reference to `perf_arch_fetch_caller_regs'
	(.text+0x3324): undefined reference to `perf_arch_fetch_caller_regs'
	(.text+0x33bc): undefined reference to `perf_arch_fetch_caller_regs'
	(.text+0x33ec): undefined reference to `perf_arch_fetch_caller_regs'
	(.text+0xd4a0): undefined reference to `perf_arch_fetch_caller_regs'
	arch/powerpc/kernel/built-in.o:(.text+0xd528): more undefined references to `perf_arch_fetch_caller_regs' follow
	make[1]: *** [.tmp_vmlinux1] Error 1
	make: *** [sub-make] Error 2
Reported-by: Michael Ellerman <michael@ellerman.id.au>
Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>

Now that software events use perf_arch_fetch_caller_regs() too, we
need the stub version to be always built in for archs that don't
implement it.

Fixes the following build error in PARISC:

	kernel/built-in.o: In function `perf_event_task_sched_out':
	(.text.perf_event_task_sched_out+0x54): undefined reference to `perf_arch_fetch_caller_regs'
Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>

* master.kernel.org:/home/rmk/linux-2.6-arm:
  ARM: 5965/1: Fix soft lockup in at91 udc driver
  ARM: 6006/1: ARM: Use the correct NOP size in memmove for Thumb-2 kernel builds
  ARM: 6005/1: arm: kprobes: fix register corruption with jprobes
  ARM: 6003/1: removing compilation warning from pl061.h
  ARM: 6001/1: removing compilation warning comming from clkdev.h
  ARM: 6000/1: removing compilation warning comming from <asm/irq.h>
  ARM: 5999/1: Including device.h and resource.h header files in linux/amba/bus.h
  ARM: 5997/1: ARM: Correct the VFPv3 detection
  ARM: 5996/1: ARM: Change the mandatory barriers implementation (4/4)
  ARM: 5995/1: ARM: Add L2x0 outer_sync() support (3/4)
  ARM: 5994/1: ARM: Add outer_cache_fns.sync function pointer (2/4)
  ARM: 5993/1: ARM: Move the outer_cache definitions into a separate file (1/4)

* 'merge' of git://git.secretlab.ca/git/linux-2.6:
  powerpc/5200: in lpbfifo, flag DMA irqs as enabled after requesting them
  powerpc/fsl: add device tree binding for QE firmware
  of/flattree: Fix unhandled OF_DT_NOP tag when unflattening the device tree

Merge branch 'reiserfs/kill-bkl' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing

* 'reiserfs/kill-bkl' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing:
  reiserfs: Fix locking BUG during mount failure

The missing initialization of the nb_cntl.strap_msi_enable does not
seem to be the only problem that prevents MSI, so that quirk is not
sufficient to enable MSI on all machines.  To be safe, disable MSI
unconditionally for the internal graphics and HDMI audio on these
chipsets.

[rjw: Added the PCI_VENDOR_ID_AI quirk.]
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* 'kgdb-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb:
  kgdb: Turn off tracing while in the debugger
  kgdb: use atomic_inc and atomic_dec instead of atomic_set
  kgdb: eliminate kgdb_wait(), all cpus enter the same way
  kgdbts,sh: Add in breakpoint pc offset for superh
  kgdb: have ebin2mem call probe_kernel_write once