The bug is we're not able to remove the device from blkio cgroup's
per-device control files if it gets unplugged.

To reproduce the bug:

  # mount -t cgroup -o blkio xxx /cgroup
  # cd /cgroup
  # echo "8:0 1000" > blkio.throttle.read_bps_device
  # unplug the device
  # cat blkio.throttle.read_bps_device
  8:0	1000
  # echo "8:0 0" > blkio.throttle.read_bps_device
  -bash: echo: write error: No such device

After patching, the device removal will succeed.

Thanks for the comments of Paul, Zefan, and Vivek.
Signed-off-by: NWanlong Gao <gaowanlong@cn.fujitsu.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Paul Menage <paul@paulmenage.org>
Acked-by: NVivek Goyal <vgoyal@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

In __blk_complete_request, we check both QUEUE_FLAG_SAME_COMP and req->cpu
to decide whether we should use req->cpu. Actually the user can also
select the complete cpu by either setting BIO_CPU_AFFINE or by calling
bio_set_completion_cpu. Current solution makes these 2 ways don't work
any more. So we'd better just check req->cpu.
Signed-off-by: NTao Ma <boyu.mt@taobao.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

CC: Wu Fengguang <fengguang.wu@intel.com>
CC: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

bdi_forker_thread() clears BDI_pending bit at the end of the main loop.
However clearing of this bit must not be done in some cases which is
handled by calling 'continue' from switch statement. That's kind of
unusual construct and without a good reason so change the function into
more intuitive code flow.

CC: Wu Fengguang <fengguang.wu@intel.com>
CC: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

Cleaning up the code a little bit. attempt_plug_merge() traverses the plug
list anyway, we can do the request counting there, so stack size is reduced
a little bit.
The motivation here is I suspect if we should count the requests for each
queue (task could handle multiple disks in the meantime), but my test doesn't
show it's worthy doing. If somebody proves we should do it, below change
will make that more easier.
Signed-off-by: NShaohua Li <shli@kernel.org>
Signed-off-by: NShaohua Li <shaohua.li@intel.com>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

Do blk_flush_plug_list() first and then add new request aDo blk_flush_plug_list() first and then add new request aDo blk_flush_plug_list() first and then add new request at the tail. New
request can't be merged to existing requests, but later new requests might
be merged with this new one. If blk_flush_plug_list() is done later, the
merge doesn't happen.
Believe it or not, this fixes a 10% regression running sysbench workload.
Signed-off-by: NShaohua Li <shli@kernel.org>
Signed-off-by: NShaohua Li <shaohua.li@intel.com>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

Commit 5757a6d7 added the QUEUE_FLAG_SAME_FORCE flag, but fails to
clear that flag when the current state is '2' (SAME_COMP + SAME_FORCE)
and the new state is '1' (SAME_COMP).
Acked-by: NDan Williams <dan.j.williams@intel.com>
Reviewed-by: NRoland Dreier <roland@purestorage.com>
Signed-off-by: NEric Seppanen <eric@purestorage.com>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

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

Add a new REQ_PRIO to let requests preempt others in the cfq I/O schedule,
and lave REQ_META purely for marking requests as metadata in blktrace.

All existing callers of REQ_META except for XFS are updated to also
set REQ_PRIO for now.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NNamhyung Kim <namhyung@gmail.com>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

Replace all occurnanced of the undocumented READ_META with READ | REQ_META
and remove the unused WRITE_META define.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

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

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  perf tools: Add group event scheduling option to perf record/stat
  MAINTAINERS: Fix list of perf events source files
  perf tools: Fix build against newer glibc
  perf tools: Fix error handling of unknown events
  perf evlist: Fix missing event name init for default event
  perf list: Fix exit value

* 'stable/bug.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen/tracing: Fix tracing config option properly
  xen: Do not enable PV IPIs when vector callback not present
  xen/x86: replace order-based range checking of M2P table by linear one
  xen: xen-selfballoon.c needs more header files

This patch fixes belows:

1. Fix code style issue.
2. Fix incorrect functions name in comments.
Signed-off-by: NJoe Jin <joe.jin@oracle.com>
Cc: Jens Axboe <jaxboe@fusionio.com>
Cc: Ian Campbell <Ian.Campbell@eu.citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

When do block-attach/block-detach test with below steps, umount hangs
in the guest. Furthermore shutdown ends up being stuck when umounting file-systems.

1. start guest.
2. attach new block device by xm block-attach in Dom0.
3. mount new disk in guest.
4. execute xm block-detach to detach the block device in dom0 until timeout
5. Any request to the disk will hung.

Root cause:
This issue is caused when setting backend device's state to
'XenbusStateClosing', which sends to the frontend the XenbusStateClosing
notification. When frontend receives the notification it tries to release
the disk in blkfront_closing(), but at that moment the disk is still in use
by guest, so frontend refuses to close. Specifically it sets the disk state to
XenbusStateClosing and sends the notification to backend - when backend receives the
event, it disconnects the vbd from real device, and sets the vbd device state to
XenbusStateClosing. The backend disconnects the real device/file, and any IO
requests to the disk in guest will end up in ether, leaving disk DEAD and set to
XenbusStateClosing. When the guest wants to disconnect the disk, umount will
hang on blkif_release()->xlvbd_release_gendisk() as it is unable to send any IO
to the disk, which prevents clean system shutdown.

Solution:
Don't disconnect backend until frontend state switched to XenbusStateClosed.
Signed-off-by: NJoe Jin <joe.jin@oracle.com>
Cc: Daniel Stodden <daniel.stodden@citrix.com>
Cc: Jens Axboe <jaxboe@fusionio.com>
Cc: Annie Li <annie.li@oracle.com>
Cc: Ian Campbell <Ian.Campbell@eu.citrix.com>
[v1: Modified description a bit]
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Steven Rostedt says we should use CONFIG_EVENT_TRACING.

Cc:Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Fix regression for HVM case on older (<4.1.1) hypervisors caused by

  commit 99bbb3a8
  Author: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
  Date:   Thu Dec 2 17:55:10 2010 +0000

    xen: PV on HVM: support PV spinlocks and IPIs

This change replaced the SMP operations with event based handlers without
taking into account that this only works when the hypervisor supports
callback vectors. This causes unexplainable hangs early on boot for
HVM guests with more than one CPU.

BugLink: http://bugs.launchpad.net/bugs/791850

CC: stable@kernel.org
Signed-off-by: NStefan Bader <stefan.bader@canonical.com>
Signed-off-by: NStefano Stabellini <stefano.stabellini@eu.citrix.com>
Tested-and-Reported-by: NStefan Bader <stefan.bader@canonical.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6:
  firewire: core: handle ack_busy when fetching the Config ROM

This fixes a regression introduced by commit cdcb725c ("Btrfs: check
if there is enough space for balancing smarter").  We can't do 64-bit
divides on 32-bit architectures.

In cases where we need to divide/multiply by 2 we should just left/right
shift respectively, and in cases where theres N number of devices use
do_div.  Also make the counters u64 to match up with rw_devices.
Thanks,
Signed-off-by: NJosef Bacik <josef@redhat.com>
Acked-and-tested-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: flush any pending end_io requests before DIO reads w/dioread_nolock
  ext4: fix nomblk_io_submit option so it correctly converts uninit blocks
  ext4: Resolve the hang of direct i/o read in handling EXT4_IO_END_UNWRITTEN.
  ext4: call ext4_ioend_wait and ext4_flush_completed_IO in ext4_evict_inode
  ext4: Fix ext4_should_writeback_data() for no-journal mode

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6:
  ALSA: sound/aoa/fabrics/layout.c: remove unneeded kfree
  ALSA: hda - Fix error check from snd_hda_get_conn_index() in patch_cirrus.c
  ALSA: hda - Don't spew too many ELD errors
  ALSA: usb-audio - Fix missing mixer dB information
  ALSA: hda - Add "PCM" volume to vmaster slave list
  ALSA: hda - Fix duplicated capture-volume creation for ALC268 models
  ALSA: ac97: Add HP Compaq dc5100 SFF(PT003AW) to Headphone Jack Sense whitelist
  ALSA: snd_usb_caiaq: track submitted output urbs

Fix new kernel-doc warning in pci.c:

  Warning(drivers/pci/pci.c:3259): No description found for parameter 'mps'
  Warning(drivers/pci/pci.c:3259): Excess function parameter 'rq' description in 'pcie_set_mps'
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The label outnodev is only used when kzalloc has not yet taken place or has
failed, so there is no need for the call for kfree under this label.

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

// <smpl>
@@
identifier x;
expression E1!=0,E2,E3,E4;
statement S;
iterator I;
@@

(
if (...) { ... when != kfree(x)
               when != x = E3
               when != E3 = x
*  return ...;
 }
... when != x = E2
    when != I(...,x,...) S
if (...) { ... when != x = E4
 kfree(x); ... return ...; }
)
// </smpl>
Signed-off-by: NJulia Lawall <julia@diku.dk>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

snd_hda_get_conn_index() returns a negative value while the current code
stores it in an unsigned int.  It must be stored in a signed integer.
Reported-by: NJesper Juhl <jj@chaosbits.net>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Currently HD-audio driver shows the all error ELD byte as an error
in the kernel message.  This is annoying when the video driver doesn't
set the correct ELD from the beginning. e.g. radeon sends a zero-byte
data, but we still check ELD with the fixed 128 byte as a workaround
for some broken devices, it spews 128-times errors.

For avoiding this, the driver aborts reading when the first byte is
invalid.  In such a case, the whole data is certainly invalid.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/drm-intel:
  drm/i915: set GFX_MODE to pre-Ivybridge default value even on Ivybridge

There is a race between ext4 buffer write and direct_IO read with
dioread_nolock mount option enabled. The problem is that we clear
PageWriteback flag during end_io time but will do
uninitialized-to-initialized extent conversion later with dioread_nolock.
If an O_direct read request comes in during this period, ext4 will return
zero instead of the recently written data.

This patch checks whether there are any pending uninitialized-to-initialized
extent conversion requests before doing O_direct read to close the race.
Note that this is just a bandaid fix. The fundamental issue is that we
clear PageWriteback flag before we really complete an IO, which is
problem-prone. To fix the fundamental issue, we may need to implement an
extent tree cache that we can use to look up pending to-be-converted extents.
Signed-off-by: NJiaying Zhang <jiayingz@google.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org

Prior to Ivybridge, the GFX_MODE would default to 0x800, meaning that
MI_FLUSH would flush the TLBs in addition to the rest of the caches
indicated in the MI_FLUSH command.  However starting with Ivybridge, the
register defaults to 0x2800 out of reset, meaning that to invalidate the
TLB we need to use PIPE_CONTROL.  Since we're not doing that yet, go
back to the old default so things work.

v2: don't forget to actually *clear* the new bit
Reviewed-by: NEric Anholt <eric@anholt.net>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Tested-by: NKenneth Graunke <kenneth@whitecape.org>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

* 'for-linus' of git://git.kernel.dk/linux-block: (23 commits)
  Revert "cfq: Remove special treatment for metadata rqs."
  block: fix flush machinery for stacking drivers with differring flush flags
  block: improve rq_affinity placement
  blktrace: add FLUSH/FUA support
  Move some REQ flags to the common bio/request area
  allow blk_flush_policy to return REQ_FSEQ_DATA independent of *FLUSH
  xen/blkback: Make description more obvious.
  cfq-iosched: Add documentation about idling
  block: Make rq_affinity = 1 work as expected
  block: swim3: fix unterminated of_device_id table
  block/genhd.c: remove useless cast in diskstats_show()
  drivers/cdrom/cdrom.c: relax check on dvd manufacturer value
  drivers/block/drbd/drbd_nl.c: use bitmap_parse instead of __bitmap_parse
  bsg-lib: add module.h include
  cfq-iosched: Reduce linked group count upon group destruction
  blk-throttle: correctly determine sync bio
  loop: fix deadlock when sysfs and LOOP_CLR_FD race against each other
  loop: add BLK_DEV_LOOP_MIN_COUNT=%i to allow distros 0 pre-allocated loop devices
  loop: add management interface for on-demand device allocation
  loop: replace linked list of allocated devices with an idr index
  ...

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6:
  PCI: OF: Don't crash when bridge parent is NULL.
  PCI: export pcie_bus_configure_settings symbol
  PCI: code and comments cleanup
  PCI: make cardbus-bridge resources optional
  PCI: make SRIOV resources optional
  PCI : ability to relocate assigned pci-resources
  PCI: honor child buses add_size in hot plug configuration
  PCI: Set PCI-E Max Payload Size on fabric

In pcibios_get_phb_of_node(), we will crash while booting if
bus->bridge->parent is NULL.

Check for this case and avoid dereferencing the NULL pointer.
Signed-off-by: NDavid Daney <david.daney@cavium.com>
Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

We have a kernel build regression since 3.1-rc1, which is about 10%
regression. The kernel source is in an ext3 filesystem.
Alex Shi bisect it to commit:
commit a07405b7
Author: Justin TerAvest <teravest@google.com>
Date:   Sun Jul 10 22:09:19 2011 +0200

    cfq: Remove special treatment for metadata rqs.

Apparently this is caused by lack metadata preemption, where ext3/ext4
do use READ_META. I didn't see a way to fix the issue, so suggest
reverting the patch.

This reverts commit a07405b7.

Reported-by: Alex Shi<alex.shi@intel.com>
Reported-by: Shaohua Li<shaohua.li@intel.com>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

The recent fix for testing dB range at the mixer creation time seems
to cause regressions in some devices.  In such devices, reading the dB
info at probing time gives an error, thus both dBmin and dBmax are still
zero, and TLV flag isn't set although the later read of dB info succeeds.

This patch adds a workaround for such a case by assuming that the later
read will succeed.  In future, a similar test should be performed in a
case where a wrong dB range is seen even in the later read.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>
Cc: <stable@kernel.org>

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc:
  sparc: fix array bounds error setting up PCIC NMI trap

* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev:
  drivers/ata/sata_dwc_460ex.c: add missing kfree
  ata: Add iMX pata support
  pata_via: disable ATAPI DMA on AVERATEC 3200
  [libata] sata_sil: fix used-uninit warning

* 'bugfixes' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  NFSv4.1: Return NFS4ERR_BADSESSION to callbacks during session resets
  NFSv4.1: Fix the callback 'highest_used_slotid' behaviour
  pnfs-obj: Fix the comp_index != 0 case
  pnfs-obj: Bug when we are running out of bio
  nfs: add missing prefetch.h include

  CC      arch/sparc/kernel/pcic.o
arch/sparc/kernel/pcic.c: In function 'pcic_probe':
arch/sparc/kernel/pcic.c:359:33: error: array subscript is above array bounds [-Werror=array-bounds]
arch/sparc/kernel/pcic.c:359:8: error: array subscript is above array bounds [-Werror=array-bounds]
arch/sparc/kernel/pcic.c:360:33: error: array subscript is above array bounds [-Werror=array-bounds]
arch/sparc/kernel/pcic.c:360:8: error: array subscript is above array bounds [-Werror=array-bounds]
arch/sparc/kernel/pcic.c:361:33: error: array subscript is above array bounds [-Werror=array-bounds]
arch/sparc/kernel/pcic.c:361:8: error: array subscript is above array bounds [-Werror=array-bounds]
cc1: all warnings being treated as errors

I'm not particularly familiar with sparc but t_nmi (defined in head_32.S via
the TRAP_ENTRY macro) and pcic_nmi_trap_patch (defined in entry.S) both appear
to be 4 instructions long and I presume from the usage that instructions are
int sized.
Signed-off-by: NIan Campbell <ian.campbell@citrix.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: sparclinux@vger.kernel.org
Reviewed-by: NSam Ravnborg <sam@ravnborg.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently, error handling code in this function calls the function
sata_dwc_port_stop, but this function has essentially no effect if hsdevp
has not been stored in ap, which is the case throughout this function.  The
only effect is to print a debugging message including ap->print_id.

The code is rewritten to not call sata_dwc_port_stop, but instead to jump
to a local label that prints the original error message and the print_id
information.  In the case where hsdevp has been already allocated (but not
yet stored in ap), this value is freed as well.

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

// <smpl>
@exists@
local idexpression x;
statement S,S1;
expression E;
identifier fl;
expression *ptr != NULL;
@@

x = \(kmalloc\|kzalloc\|kcalloc\)(...);
...
if (x == NULL) S
<... when != x
     when != if (...) { <+...kfree(x)...+> }
     when any
     when != true x == NULL
x->fl
...>
(
if (x == NULL) S1
|
if (...) { ... when != x
               when forall
(
 return \(0\|<+...x...+>\|ptr\);
|
* return ...;
)
}
)
// </smpl>
Signed-off-by: NJulia Lawall <julia@diku.dk>
Signed-off-by: NJeff Garzik <jgarzik@pobox.com>

Add basic support for pata on iMX. It has been tested only on imx51.
SDMA support will probably be added later so this version supports only
PIO.

v2:
  - enable only when needed IORDY
  - use dev_get_drvdata
v3:
  - add missing clk_put() calls
  - use platform_get_irq()
  - fix resume code to avoid disabling IORDY on resume
v4:
  - Remove EXPERIMENTAL and switch to depends on ARCH_MXC
  - Use devm_kzalloc()
  - make clock a must-have
  - Use only 1 ioremap
Signed-off-by: NArnaud Patard <arnaud.patard@rtp-net.org>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

On AVERATEC 3200, pata_via causes memory corruption with ATAPI DMA,
which often leads to random kernel oops.  The cause of the problem is
not well understood yet and only small subset of machines using the
controller seem affected.  Blacklist ATAPI DMA on the machine.
Signed-off-by: NTejun Heo <tj@kernel.org>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=11426Reported-and-tested-by: NJim Bray <jimsantelmo@gmail.com>
Cc: Alan Cox <alan@linux.intel.com>
Cc: stable@kernel.org
Signed-off-by: NJeff Garzik <jgarzik@pobox.com>