This patch is part of fix for triggering of WARN_ON_ONCE() in
disk_clear_events() reported in bug#34662.

  https://bugzilla.kernel.org/show_bug.cgi?id=34662

disk_clear_events() blocks events, schedules and flushes the event
work.  It expects the work to have started execution on schedule and
finished on return from flush.  WARN_ON_ONCE() triggers if the event
work hasn't executed as expected.  This problem happens because
__disk_block_events() fails to guarantee that the event work item is
not in flight on return from the function in race-free manner.  The
problem is two-fold and this patch addresses one of them.

When __disk_block_events() is called with @sync == %false, it bumps
event block count, calls cancel_delayed_work() and return.  This makes
it impossible to guarantee that event polling is not in flight on
return from syncing __disk_block_events() - if the first blocker was
non-syncing, polling could still be in progress and later syncing ones
would assume that the first blocker already canceled it.

Making __disk_block_events() cancel_sync regardless of block count
isn't feasible either as it may race with forced event checking in
disk_clear_events().

As disk_check_events() is the only user of non-syncing
__disk_block_events(), updating it to directly cancel and schedule
event work is the easiest way to solve the issue.

Note that there's another bug in __disk_block_events() and this patch
doesn't fix the issue completely.  Later patch will fix the other bug.
Signed-off-by: NTejun Heo <tj@kernel.org>
Tested-by: NSitsofe Wheeler <sitsofe@yahoo.com>
Reported-by: NSitsofe Wheeler <sitsofe@yahoo.com>
Reported-by: NBorislav Petkov <bp@alien8.de>
Reported-by: NMeelis Roos <mroos@linux.ee>
Reported-by: NLinus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

Since we are modifying this RCU pointer, we need to hold
the lock protecting it around it.

This fixes a potential reuse and double free of a cfq
io_context structure. The bug has been in CFQ for a long
time, it hit very few people but those it did hit seemed
to see it a lot.

Tracked in RH bugzilla here:

https://bugzilla.redhat.com/show_bug.cgi?id=577968

Credit goes to Paul Bolle for figuring out that the issue
was around the one-hit ioc->ioc_data cache. Thanks to his
hard work the issue is now fixed.

Cc: stable@kernel.org
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-rc-fixes-2.6:
  [SCSI] Fix oops caused by queue refcounting failure

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (40 commits)
  tg3: Fix tg3_skb_error_unmap()
  net: tracepoint of net_dev_xmit sees freed skb and causes panic
  drivers/net/can/flexcan.c: add missing clk_put
  net: dm9000: Get the chip in a known good state before enabling interrupts
  drivers/net/davinci_emac.c: add missing clk_put
  af-packet: Add flag to distinguish VID 0 from no-vlan.
  caif: Fix race when conditionally taking rtnl lock
  usbnet/cdc_ncm: add missing .reset_resume hook
  vlan: fix typo in vlan_dev_hard_start_xmit()
  net/ipv4: Check for mistakenly passed in non-IPv4 address
  iwl4965: correctly validate temperature value
  bluetooth l2cap: fix locking in l2cap_global_chan_by_psm
  ath9k: fix two more bugs in tx power
  cfg80211: don't drop p2p probe responses
  Revert "net: fix section mismatches"
  drivers/net/usb/catc.c: Fix potential deadlock in catc_ctrl_run()
  sctp: stop pending timers and purge queues when peer restart asoc
  drivers/net: ks8842 Fix crash on received packet when in PIO mode.
  ip_options_compile: properly handle unaligned pointer
  iwlagn: fix incorrect PCI subsystem id for 6150 devices
  ...

* 'for-linus' of git://git.kernel.dk/linux-block:
  block: Use hlist_entry() for io_context.cic_list.first
  cfq-iosched: Remove bogus check in queue_fail path
  xen/blkback: potential null dereference in error handling
  xen/blkback: don't call vbd_size() if bd_disk is NULL
  block: blkdev_get() should access ->bd_disk only after success
  CFQ: Fix typo and remove unnecessary semicolon
  block: remove unwanted semicolons
  Revert "block: Remove extra discard_alignment from hd_struct."
  nbd: adjust 'max_part' according to part_shift
  nbd: limit module parameters to a sane value
  nbd: pass MSG_* flags to kernel_recvmsg()
  block: improve the bio_add_page() and bio_add_pc_page() descriptions

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/vapier/blackfin:
  Blackfin: strncpy: fix handling of zero lengths

* 'stable' of git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile:
  asm-generic/unistd.h: support sendmmsg syscall
  tile: enable CONFIG_BUGVERBOSE

* 'linux-next' of git://git.infradead.org/ubifs-2.6:
  UBIFS: fix-up free space earlier
  UBIFS: intialize LPT earlier
  UBIFS: assert no fixup when writing a node
  UBIFS: fix clean znode counter corruption in error cases
  UBIFS: fix memory leak on error path
  UBIFS: fix shrinker object count reports
  UBIFS: fix recovery broken by the previous recovery fix
  UBIFS: amend ubifs_recover_leb interface
  UBIFS: introduce a "grouped" journal head flag
  UBIFS: supress false error messages

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-ktest:
  ktest: Ignore unset values of the minconfig in config_bisect
  ktest: Fix result of rebooting the kernel
  ktest: Fix off-by-one in config bisect result

Merge branch 'rmobile-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6

* 'rmobile-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6:
  ARM: mach-shmobile: add DMAC clock definitions on SH7372
  ARM: arch-shmobile: support SDHI card detection on mackerel, using a GPIO
  sh_mobile_meram: MERAM platform data for LCDC

* 'sh-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6:
  dmaengine: shdma: fix a regression: initialise DMA channels for memcpy
  dmaengine: shdma: Fix up fallout from runtime PM changes.
  Revert "clocksource: sh_cmt: Runtime PM support"
  Revert "clocksource: sh_tmu: Runtime PM support"
  sh: Fix up asm-generic/ptrace.h fallout.
  sh64: Move from P1SEG to CAC_ADDR for consistent sync.
  sh64: asm/pgtable.h needs asm/mmu.h
  sh: asm/tlb.h needs linux/swap.h
  sh: mark DMA slave ID 0 as invalid
  sh: Update shmin to reflect PIO dependency.
  sh: arch/sh/kernel/process_32.c needs linux/prefetch.h.
  sh: add MMCIF runtime PM support on ecovec
  sh: switch ap325rxa to dynamically manage the platform camera

This reverts commit ed0bd233.

Since we reverted the TTY API change, we should revert the ASoC update
to it too.

Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Liam Girdwood <lrg@ti.com>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This reverts commit b1c43f82.

It was broken in so many ways, and results in random odd pty issues.

It re-introduced the buggy schedule_work() in flush_to_ldisc() that can
cause endless work-loops (see commit a5660b41: "tty: fix endless
work loop when the buffer fills up").

It also used an "unsigned int" return value fo the ->receive_buf()
function, but then made multiple functions return a negative error code,
and didn't actually check for the error in the caller.

And it didn't actually work at all.  BenH bisected down odd tty behavior
to it:
  "It looks like the patch is causing some major malfunctions of the X
   server for me, possibly related to PTYs.  For example, cat'ing a
   large file in a gnome terminal hangs the kernel for -minutes- in a
   loop of what looks like flush_to_ldisc/workqueue code, (some ftrace
   data in the quoted bits further down).

   ...

   Some more data: It -looks- like what happens is that the
   flush_to_ldisc work queue entry constantly re-queues itself (because
   the PTY is full ?) and the workqueue thread will basically loop
   forver calling it without ever scheduling, thus starving the consumer
   process that could have emptied the PTY."

which is pretty much exactly the problem we fixed in a5660b41.

Milton Miller pointed out the 'unsigned int' issue.
Reported-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Reported-by: NMilton Miller <miltonm@bga.com>
Cc: Stefan Bigler <stefan.bigler@keymile.com>
Cc: Toby Gray <toby.gray@realvnc.com>
Cc: Felipe Balbi <balbi@ti.com>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-2.6 into for-davem

The free space fixup is currently initiated during mount after the call to
ubifs_write_master() which results in a write to PEBs; this has been observed
with the patch 'assert no fixup when writing a node' applied:

Move the free space fixup on mount to before the calls to
ubifs_recover_inl_heads() and ubifs_write_master(). This results in no
assertions with the previously mentioned patch applied.

Artem: tweaked the patch a bit
Signed-off-by: NBen Gardiner <bengardiner@nanometrics>
Reviewed-by: NMatthew L. Creech <mlcreech@gmail.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

The current 'mount_ubifs()' implementation does not initialize the LPT until the
the master node is marked dirty. Move the LPT initialization to before marking
the master node dirty. This is a preparation for the next patch which will move
the free-space-fixup check to before marking the master node dirty, because we
have to fix-up the free space before doing any writes.

Artem: massaged the patch and commit message.
Signed-off-by: NBen Gardiner <bengardiner@nanometrics.ca>
Reviewed-by: NMatthew L. Creech <mlcreech@gmail.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

The current free space fixup can result in some writing to the UBI volume
when the space_fixup flag is set.

To catch instances where UBIFS is writing to the NAND while the space_fixup
flag is set, add an assert to ubifs_write_node().

Artem: tweaked the patch, added similar assertion to the write buffer
       write path.
Signed-off-by: NBen Gardiner <bengardiner@nanometrics.ca>
Reviewed-by: NMatthew L. Creech <mlcreech@gmail.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

UBIFS maintains per-filesystem and global clean znode counters
('c->clean_zn_cnt' and 'ubifs_clean_zn_cnt'). It is important to maintain
correct values there since the shrinker relies on 'ubifs_clean_zn_cnt'.

However, in case of failures during commit the counters were corrupted. E.g.,
if a failure happens in the middle of 'write_index()', then some nodes in the
commit list ('c->cnext') are marked as clean, and some are marked as dirty. And
the 'ubifs_destroy_tnc_subtree()' frees does not retrun correct count, and we
end up with non-zero 'c->clean_zn_cnt' when unmounting. This means that if we
have 2 file-sytem and one of them fails, and we unmount it,
'ubifs_clean_zn_cnt' stays incorrect and confuses the shrinker.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

UBIFS leaks memory on error path in 'ubifs_jnl_update()' in case of write
failure because it forgets to free the 'struct ubifs_dent_node *dent' object.
Although the object is small, the alignment can make it large - e.g., 2KiB
if the min. I/O unit is 2KiB.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Cc: stable@kernel.org

Sometimes VM asks the shrinker to return amount of objects it can shrink,
and we return the ubifs_clean_zn_cnt in that case. However, it is possible
that this counter is negative for a short period of time, due to the way
UBIFS TNC code updates it. And I can observe the following warnings sometimes:

shrink_slab: ubifs_shrinker+0x0/0x2b7 [ubifs] negative objects to delete nr=-8541616642706119788

This patch makes sure UBIFS never returns negative count of objects.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Cc: stable@kernel.org

The jump to 4f will cause the NUL padding loop to run at least one time,
so if string length is zero just jump to the end.  Otherwise we wrongly
write one NUL byte when size==0.
Signed-off-by: NSteven Miao <realmz6@gmail.com>
Signed-off-by: NMike Frysinger <vapier@gentoo.org>

This function attempts to free one fragment beyond the number of
fragments that were actually mapped.  This patch brings back the limit
to the correct spot.
Signed-off-by: NMatt Carlson <mcarlson@broadcom.com>
Tested-by: NAlex Williamson <alex.williamson@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Because there is a possibility that skb is kfree_skb()ed and zero cleared
after ndo_start_xmit, we should not see the contents of skb like skb->len and
skb->dev->name after ndo_start_xmit. But trace_net_dev_xmit does that
and causes panic by NULL pointer dereference.
This patch fixes trace_net_dev_xmit not to see the contents of skb directly.

If you want to reproduce this panic,

1. Get tracepoint of net_dev_xmit on
2. Create 2 guests on KVM
2. Make 2 guests use virtio_net
4. Execute netperf from one to another for a long time as a network burden
5. host will panic(It takes about 30 minutes)
Signed-off-by: NKoki Sanagi <sanagi.koki@jp.fujitsu.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>

By ignoring the unset values of the minconfig in deciding
what to test in the config_bisect can cause the problem
config from being tested too.

Just do not test the configs that are set in the minconfig.
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

The command that is called that reboots the kernel may fail
but the return code is not passed back to the ktest.pl script.
This is because a ';' is used between the two commands and
if the second command fails, only the first command's return
code is returned. Using a '&&' between the two commands fixes
this.
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Because in perl the array size returned by $#arr, is the last
index and not the actually size of the array, we end the config
bisect early, thinking there is only one config left when there
are in fact two. Thus the result has a 50% chance of picking
the correct config that caused the problem.
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Merge branch 'for-jens/xen-blkback.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen into for-linus

list_entry() and hlist_entry() are both simply aliases for
container_of(), but since io_context.cic_list.first is an hlist_node one
should at least use the correct alias.
Signed-off-by: NPaul Bolle <pebolle@tiscali.nl>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

queue_fail can only be reached if cic is NULL, so its check for cic must
be bogus.
Signed-off-by: NPaul Bolle <pebolle@tiscali.nl>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

In certain circumstances, we can get an oops from a torn down device.
Most notably this is from CD roms trying to call scsi_ioctl.  The root
cause of the problem is the fact that after scsi_remove_device() has
been called, the queue is fully torn down.  This is actually wrong
since the queue can be used until the sdev release function is called.
Therefore, we add an extra reference to the queue which is released in
sdev->release, so the queue always exists.
Reported-by: NParag Warudkar <parag.lkml@gmail.com>
Cc: stable@kernel.org
Signed-off-by: NJames Bottomley <jbottomley@parallels.com>

The failed_get label is used after the call to clk_get has succeeded, so it
should be moved up above the call to clk_put.

The failed_req labels doesn't do anything different than failed_get, so
delete it.

A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@r exists@
expression e1,e2;
statement S;
@@

e1 = clk_get@p1(...);
... when != e1 = e2
    when != clk_put(e1)
    when any
if (...) { ... when != clk_put(e1)
               when != if (...) { ... clk_put(e1) ... }
* return@p3 ...;
 } else S
// </smpl>
Signed-off-by: NJulia Lawall <julia@diku.dk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

These definitions are needed to let the runtime PM subsystem turn off
DMAC clocks, when it is suspended by the driver.
Signed-off-by: NGuennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

A recent patch has introduced a regression, where repeating a memcpy
DMA test with shdma module unloading between them skips the DMA channel
configuration. Fix this regression by always configuring the channel
during its allocation.
Signed-off-by: NGuennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Currently the DM9000 driver requests the primary interrupt before it
resets the chip and puts it into a known good state. This means that if
the chip is asserting interrupt for some reason we can end up with a
screaming IRQ that the interrupt handler is unable to deal with. Avoid
this by only requesting the interrupt after we've reset the chip so we
know what state it's in.

This started manifesting itself on one of my boards in the past month or
so, I suspect as a result of some core infrastructure changes removing
some form of mitigation against bad behaviour here, even when things boot
it seems that the new code brings the interface up more quickly.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Go to existing error handling code at the end of the function that calls
clk_put.

A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@r exists@
expression e1,e2;
statement S;
@@

e1 = clk_get@p1(...);
... when != e1 = e2
    when != clk_put(e1)
    when any
if (...) { ... when != clk_put(e1)
               when != if (...) { ... clk_put(e1) ... }
* return@p3 ...;
 } else S
// </smpl>
Signed-off-by: NJulia Lawall <julia@diku.dk>
Acked-by: NKevin Hilman <khilman@ti.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently, user-space cannot determine if a 0 tcp_vlan_tci
means there is no VLAN tag or the VLAN ID was zero.

Add flag to make this explicit.  User-space can check for
TP_STATUS_VLAN_VALID || tp_vlan_tci > 0, which will be backwards
compatible. Older could would have just checked for tp_vlan_tci,
so it will work no worse than before.
Signed-off-by: NBen Greear <greearb@candelatech.com>
Acked-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Take the RTNL lock unconditionally when calling dev_close.
Taking the lock conditionally may cause race conditions.
Signed-off-by: NSjur Brændeland <sjur.brandeland@stericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This avoids messages like this after suspend:

   cdc_ncm 2-1.4:1.6: no reset_resume for driver cdc_ncm?
   cdc_ncm 2-1.4:1.7: no reset_resume for driver cdc_ncm?
   cdc_ncm 2-1.4:1.6: usb0: unregister 'cdc_ncm' usb-0000:00:1d.0-1.4, CDC NCM

This is important for the Ericsson F5521gw GSM/UMTS modem.
Otherwise modemmanager looses the fact that the cdc_ncm and cdc_acm devices
belong together.

The cdc_ether module does the same.
Signed-off-by: NStefan Metzmacher <metze@samba.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

commit 4af429d2 (vlan: lockless
transmit path) have a typo in vlan_dev_hard_start_xmit(), using
u64_stats_update_begin() to end the stat update, it should be
u64_stats_update_end().
Signed-off-by: NWei Yongjun <yjwei@cn.fujitsu.com>
Reviewed-by: NWANG Cong <xiyou.wangcong@gmail.com>
Acked-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>