Cfq has a bug in computation of next_rq, that affects transition
between multiple sequential request streams in a single queue
(e.g.: two sequential buffered writers of the same priority),
causing the alternation between the two streams for a transient period.

  8,0    1    18737     0.260400660  5312  D   W 141653311 + 256
  8,0    1    20839     0.273239461  5400  D   W 141653567 + 256
  8,0    1    20841     0.276343885  5394  D   W 142803919 + 256
  8,0    1    20843     0.279490878  5394  D   W 141668927 + 256
  8,0    1    20845     0.292459993  5400  D   W 142804175 + 256
  8,0    1    20847     0.295537247  5400  D   W 141668671 + 256
  8,0    1    20849     0.298656337  5400  D   W 142804431 + 256
  8,0    1    20851     0.311481148  5394  D   W 141668415 + 256
  8,0    1    20853     0.314421305  5394  D   W 142804687 + 256
  8,0    1    20855     0.318960112  5400  D   W 142804943 + 256

The fix makes sure that the next_rq is computed from the last
dispatched request, and not affected by merging.

  8,0    1    37776     4.305161306     0  D   W 141738087 + 256
  8,0    1    37778     4.308298091     0  D   W 141738343 + 256
  8,0    1    37780     4.312885190     0  D   W 141738599 + 256
  8,0    1    37782     4.315933291     0  D   W 141738855 + 256
  8,0    1    37784     4.319064459     0  D   W 141739111 + 256
  8,0    1    37786     4.331918431  5672  D   W 142803007 + 256
  8,0    1    37788     4.334930332  5672  D   W 142803263 + 256
  8,0    1    37790     4.337902723  5672  D   W 142803519 + 256
  8,0    1    37792     4.342359774  5672  D   W 142803775 + 256
  8,0    1    37794     4.345318286     0  D   W 142804031 + 256
Signed-off-by: Corrado Zoccolo <czoccolo@gmail.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>

When there are many blocks on the fly (ua), and the AL gets into "starving"
mode (random IO, scattered all over the device), and the connections gets
interrupted, the receiver thread deadlocks in the drbd_disconnect() code path.

Affected are only nodes in Primary role.

The bug triggers most likely on system that mirror over "long distances"

Regression introduced shortly before 8.3.3
with git commit 31e0f1250f174ac1ee317f360943a0159e19edc8
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>

When IO gets frozen due to a broken fence-peer script, the user
should be able to thaw IO by the resume-io command.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>

To check wether we are truncating a very large device due to limited
meta data space, we need to check the ll_dev size.

Also improve the printk to suggest "flexible" or "internal".
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>

Quiet sparse noise about symbol's not being declared.

Symbol blk_default_cmd_filter is only used locally and should be static.

The function blk_scsi_ioctl_init() is a fs_initcall and should also be
static.
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

sendfile(2) was reworked with the splice infrastructure, but it still
checks f_op.sendpage() instead of f_op.splice_write() wrongly.  Although
if f_op.sendpage() exists, f_op.splice_write() always exists at the same
time currently, the assumption will be broken in future silently.  This
patch also brings a side effect: sendfile(2) can work with any output
file.  Some security checks related to f_op are added too.
Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

The current PS3 VRAM driver uses msleep() to wait for completion of RSX
DMA transfers between system memory and VRAM.  Depending on the system
timing, the processing delay and overhead of this msleep() call can
significantly impact VRAM driver IO.

To avoid the condition, add a short duration (200 usec max) udelay()
polling loop before entering the msleep() polling loop.
Signed-off-by: Hideyuki Sasaki <xhide@rd.scei.sony.co.jp>
Signed-off-by: Geoff Levand <geoffrey.levand@am.sony.com>
Acked-by: Jim Paris <jim@jtan.com>
Cc: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

We need to rework this logic post the cooperating cfq_queue merging,
for now just get rid of it and Jeff Moyer will fix the fall out.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

We ended up with testing the same condition twice, pretty
pointless. Remove that first if.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Conflicts:
	block/cfq-iosched.c
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

CFQ has an optimization for cooperated applications. if several
io-context have close requests, they will get boost. But the
optimization get abused. Considering thread a, b, which work on one
file. a reads sectors s, s+2, s+4, ...; b reads sectors s+1, s+3, s
+5, ... Both a and b are sequential read, so they can open idle window.
a reads a sector s and goes to idle window and wakeup b. b reads sector
s+1, since in current implementation, cfq_should_preempt() thinks a and
b are cooperators, b will preempt a. b then reads sector s+1 and goes to
idle window and wakeup a. for the same reason, a will preempt b and
reads s+2. a and b will continue the circle. The circle will be very
long, and a and b will occupy whole disk queue. Other applications will
nearly have no chance to run.

Fix this limiting coop preempt until a queue is scheduled normally
again.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Commit a6151c3a inadvertently reversed
a preempt condition check, potentially causing a performance regression.
Make the meta check correct again.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Commit 592b09a4 was different from
the tested path, in that it moved the bdi super_block prune from
unregister to destroy context. This doesn't fully fix the sync hang
bug on unexpected device removal, as need to prune the bdi cache
pointer before killing flusher thread.
Tested-by: Artur Skawina <art.08.09@gmail.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Commit 451a9ebf accidentally broke bio_alloc() and bio_kmalloc() comments by
(almost) swapping them.

This patch fixes that, by placing the comments in the right place.
Signed-off-by: Alberto Bertogli <albertito@blitiri.com.ar>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

So remove both the comment and the inline requirement, going back to the
inline hint.
Signed-off-by: Alberto Bertogli <albertito@blitiri.com.ar>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

In bio_put()'s comment, add bio_clone() to the list of functions that can
give you a bio reference.
Signed-off-by: Alberto Bertogli <albertito@blitiri.com.ar>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Eliminate redundant checks.
Signed-off-by: Corrado Zoccolo <czoccolo@gmail.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging-2.6:
  Staging: fix wireless drivers depends
  Staging: wireless drivers Kconfig change
  Staging: android: mark subsystem as broken
  Staging: remove stlc45xx driver
  Staging: rtl8187se/rtl8192e/rtl8192su: allow module unload
  Staging: vt6656: fix the memory free bug in vntwusb_disconnect()
  Staging: Panel: prevent driver from calling misc_deregister twice on same ressource
  Staging: hv: fix oops in vmbus - missing #include
  Staging: hv: fix oops in vmbus - netvsc list_head
  Staging: hv: fix oops in vmbus - udev events
  Staging: hv: Fix vmbus load hang caused by faulty data packing
  Staging: hv: Fix null pointer error after vmbus loading
  Staging: hv TODO patches

* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb-2.6:
  USB: fsl_udc_core: Fix kernel oops on module removal
  USB: option: TLAYTECH TUE800 support
  USB: r8a66597-hcd: fix cannot detect a device when uses_new_polling is set
  USB: serial: sierra driver autopm fixes
  USB: serial: sierra driver send_setup() autopm fix
  USB: rndis_host: debug info clobbered before it is logged

* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6:
  tty: Mark generic_serial users as BROKEN

* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6:
  Documentation: ABI: /sys/devices/system/cpu/cpu#/node
  Documentation: ABI: /sys/devices/system/cpu/cpuidle/
  Documentation: ABI: /sys/devices/system/cpu/sched_[mc|smt]_power_savings
  Documentation: ABI: /sys/devices/system/cpu/cpu#/ topology files
  Documentation: ABI: /sys/devices/system/cpu/ topology files
  Documentation: ABI: document /sys/devices/system/cpu/
  Documentation: ABI: rename sysfs-devices-cache_disable properly
  Driver core: allow certain drivers prohibit bind/unbind via sysfs
  Driver core: fix driver_register() return value

* 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6:
  [S390] smp: fix sigp sense handling
  [S390] smp: fix sigp stop handling
  [S390] cputime: fix overflow on 31 bit systems
  [S390] call home: fix string length handling
  [S390] call home: fix error handling in init function
  [S390] smp: fix prefix handling of offlined cpus
  [S390] s/r: cmm resume fix
  [S390] call home: fix local buffer usage in proc handler

* 'for-linus' of git://git.kernel.org/pub/scm/fs/xfs/xfs:
  xfs: fix xfs_quota remove error
  xfs: free temporary cursor in xfs_dialloc

* 'for-linus' of git://neil.brown.name/md:
  async_tx: fix asynchronous raid6 recovery for ddf layouts
  async_pq: rename scribble page
  async_pq: kill a stray dma_map() call and other cleanups
  md/raid6: kill a gcc-4.0.1 'uninitialized variable' warning
  raid6/async_tx: handle holes in block list in async_syndrome_val
  md/async: don't pass a memory pointer as a page pointer.
  md: Fix handling of raid5 array which is being reshaped to fewer devices.
  md: fix problems with RAID6 calculations for DDF.
  md/raid456: downlevel multicore operations to raid_run_ops
  md: drivers/md/unroll.pl replaced with awk analog
  md: remove clumsy usage of do_sync_mapping_range from bitmap code
  md: raid1/raid10: handle allocation errors during array setup.
  md/raid5: initialize conf->device_lock earlier
  md/raid1/raid10: add a cond_resched
  Revert "md: do not progress the resync process if the stripe was blocked"

Commit ef7562b7 ("dpt_i2o: Fix up
copy*user") had a silly typo: EINVAL should be -EINVAL.
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: stable@kernel.org
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Don't pass NULL pointers to fput() in the error handling paths of the NOMMU
do_mmap_pgoff() as it can't handle it.

The following can be used as a test program:

	int main() { static long long a[1024 * 1024 * 20] = { 0 }; return a;}

Without the patch, the code oopses in atomic_long_dec_and_test() as called by
fput() after the kernel complains that it can't allocate that big a chunk of
memory.  With the patch, the kernel just complains about the allocation size
and then the program segfaults during execve() as execve() can't complete the
allocation of all the new ELF program segments.
Reported-by: Robin Getz <rgetz@blackfin.uclinux.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Robin Getz <rgetz@blackfin.uclinux.org>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Describe NUMA node symlink created for CPUs when CONFIG_NUMA is set.

Cc: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Document cpuidle sysfs attributes by reading code, Documentation/cpuidle/,
and git logs.

Cc: Venki Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Len Brown <lenb@kernel.org>
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Document sched_[mc|smt]_power_savings by reading existing code and
git logs.

Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Add brief descriptions for the following sysfs files:

	/sys/devices/system/cpu/cpu#/topology/core_id
	/sys/devices/system/cpu/cpu#/topology/core_siblings
	/sys/devices/system/cpu/cpu#/topology/core_siblings_list
	/sys/devices/system/cpu/cpu#/topology/physical_package_id
	/sys/devices/system/cpu/cpu#/topology/thread_siblings
	/sys/devices/system/cpu/cpu#/topology/thread_siblings_list

The descriptions in Documentation/cputopology.txt weren't very
informative, so I attempted a better description based on code
reading and hopeful guessing.

Updated Documentation/cputopology.txt with the better descriptions and
fixed some style issues.

Cc: Mike Travis <travis@sgi.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Add brief descriptions for the following sysfs files:

	/sys/devices/system/cpu/kernel_max
	/sys/devices/system/cpu/offline
	/sys/devices/system/cpu/online
	/sys/devices/system/cpu/possible
	/sys/devices/system/cpu/present

Excerpted the relevant information from Documentation/cputopology.txt
and pointed back to cputopology.txt as the authoritative source of
information.

Cc: Mike Travis <travis@sgi.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

This interface has been around for a long time, but hasn't been
officially documented.

Document the top level sysfs directory for CPU attributes.
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Rename sysfs-devices-cache_disable to sysfs-devices-system-cpu, in
order to keep a stricter correlation between a sysfs directory and
its documentation.
Reported-by: David Rientjes <rientjes@google.com>
Signed-off-by: Alex Chiang <achiang@hp.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>