struct request has an ioprio member but it is never updated because
currently bios do not hold io context information. The implication of
this is that virtio_blk ends up passing useless information to the
backend driver.

That said, some IO schedulers such as CFQ do store io context
information in struct request, but use private members for that, which
means that that information cannot be directly accessed in a IO
scheduler-independent way.

This patch adds a function to obtain the ioprio of a request. We should
avoid accessing ioprio directly and use this function instead, so that
its users do not have to care about future changes in block layer
structures or what the currently active IO controller is.

This patch does not introduce any functional changes but paves the way
for future clean-ups and enhancements.
Signed-off-by: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

It was only used by ps3disk, and it should probably have been
REQ_TYPE_LINUX_BLOCK + REQ_LB_OP_FLUSH.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

But blkdev_issue_discard() still emits requests which are interpreted as
soft barriers, because naïve callers might otherwise issue subsequent
writes to those same sectors, which might cross on the queue (if they're
reallocated quickly enough).

Callers still _can_ issue non-barrier discard requests, but they have to
take care of queue ordering for themselves.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

We may well want mkfs tools to use this to mark the whole device as
unwanted before they format it, for example.

The ioctl takes a pair of uint64_ts, which are start offset and length
in _bytes_. Although at the moment it might make sense for them both to
be in 512-byte sectors, I don't want to limit the ABI to that.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Barriers should be submitted with the WRITE flag set.
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Let the compiler see what's going on, and it can all get a lot simpler.
On PPC64 this reduces the size of the code calculating these bits by
about 60%. On x86_64 it's less of a win -- only 40%.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

We can benefit from knowing that the file system no longer cares about
the contents of certain sectors, by throwing them away immediately and
then never having to garbage collect them, and using the extra free
space to make our operations more efficient. Do so.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

[hirofumi@mail.parknet.co.jp: discard _after_ checking for corrupt chains]
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Some block devices benefit from a hint that they can forget the contents
of certain sectors. Add basic support for this to the block core, along
with a 'blkdev_issue_discard()' helper function which issues such
requests.

The caller doesn't get to provide an end_io functio, since
blkdev_issue_discard() will automatically split the request up into
multiple bios if appropriate. Neither does the function wait for
completion -- it's expected that callers won't care about when, or even
_if_, the request completes. It's only a hint to the device anyway. By
definition, the file system doesn't _care_ about these sectors any more.

[With feedback from OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> and
Jens Axboe <jens.axboe@oracle.com]
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

I have another request for the block filter SG_IO command whitelist,
specifically the MMC streaming command set SET READ AHEAD command.
The command applies only to MMC CDROM/DVDROM drives with the streaming
optional feature set.  The command is useful to cdparanoia in that it
allows explicit cache control side effects that are, on many drives,
cdparanoia's most efficient way to flush/disable the media cache on
cdrom drives. I am aware of no reason why it should not be accessible
from usespace.

Also note that the command is already fully accessible through the
SCSI-native version of the SG_IO ioctl as well as the traditional SG
interface.  The command is only being refused on block devices.  That
means that on a typical stock distro, the command is available through
/dev/sg* but not /dev/scd* although both are typically available and
accessible.  Filtering the command is not providing any protection,
only a confusing inconsistency.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

* 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus:
  [MIPS] Sibyte: Register PIO PATA device only for Swarm and Litte Sur

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6:
  tcp: Fix tcp_hybla zero congestion window growth with small rho and large cwnd.
  net: Fix netdev_run_todo dead-lock
  tcp: Fix possible double-ack w/ user dma
  net: only invoke dev->change_rx_flags when device is UP
  netrom: Fix sock_orphan() use in nr_release
  ax25: Quick fix for making sure unaccepted sockets get destroyed.
  Revert "ax25: Fix std timer socket destroy handling."
  [Bluetooth] Add reset quirk for A-Link BlueUSB21 dongle
  [Bluetooth] Add reset quirk for new Targus and Belkin dongles
  [Bluetooth] Fix double frees on error paths of btusb and bpa10x drivers

Symbol name spaghetti which is too complicated to cleanup on this stage
of the release cycle breaks the build on BCM1480 platforms.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Because of rounding, in certain conditions, i.e. when in congestion
avoidance state rho is smaller than 1/128 of the current cwnd, TCP
Hybla congestion control starves and the cwnd is kept constant
forever.

This patch forces an increment by one segment after #send_cwnd calls
without increments(newreno behavior).
Signed-off-by: Daniele Lacamera <root@danielinux.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

Benjamin Thery tracked down a bug that explains many instances
of the error

unregister_netdevice: waiting for %s to become free. Usage count = %d

It turns out that netdev_run_todo can dead-lock with itself if
a second instance of it is run in a thread that will then free
a reference to the device waited on by the first instance.

The problem is really quite silly.  We were trying to create
parallelism where none was required.  As netdev_run_todo always
follows a RTNL section, and that todo tasks can only be added
with the RTNL held, by definition you should only need to wait
for the very ones that you've added and be done with it.

There is no need for a second mutex or spinlock.

This is exactly what the following patch does.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

From: Ali Saidi <saidi@engin.umich.edu>

When TCP receive copy offload is enabled it's possible that
tcp_rcv_established() will cause two acks to be sent for a single
packet. In the case that a tcp_dma_early_copy() is successful,
copied_early is set to true which causes tcp_cleanup_rbuf() to be
called early which can send an ack. Further along in
tcp_rcv_established(), __tcp_ack_snd_check() is called and will
schedule a delayed ACK. If no packets are processed before the delayed
ack timer expires the packet will be acked twice.
Signed-off-by: David S. Miller <davem@davemloft.net>

Jesper Dangaard Brouer <hawk@comx.dk> reported a bug when setting a VLAN
device down that is in promiscous mode:

When the VLAN device is set down, the promiscous count on the real
device is decremented by one by vlan_dev_stop(). When removing the
promiscous flag from the VLAN device afterwards, the promiscous
count on the real device is decremented a second time by the
vlan_change_rx_flags() callback.

The root cause for this is that the ->change_rx_flags() callback is
invoked while the device is down. The synchronization is meant to mirror
the behaviour of the ->set_rx_mode callbacks, meaning the ->open function
is responsible for doing a full sync on open, the ->close() function is
responsible for doing full cleanup on ->stop() and ->change_rx_flags()
is meant to do incremental changes while the device is UP.

Only invoke ->change_rx_flags() while the device is UP to provide the
intended behaviour.
Tested-by: Jesper Dangaard Brouer <jdb@comx.dk>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

SLOB's ksize calculation was braindamaged and generally harmlessly
underreported the allocation size. But for very small buffers, it could
in fact overreport them, leading code depending on krealloc to overrun
the allocation and trample other data.
Signed-off-by: Matt Mackall <mpm@selenic.com>
Tested-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This reverts commit 135aedc3, as
requested by Hans Verkuil.

It was a patch for 2.6.28 where the BKL was pushed down from v4l core to
the drivers, not for 2.6.27!
Requested-by: Hans Verkuil <hverkuil@xs4all.nl>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Signed-of-by: Linus Torvalds <torvalds@linux-foundation.org>

* Theodore Ts'o (tytso@mit.edu) wrote:
>
> I've been playing with adding some markers into ext4 to see if they
> could be useful in solving some problems along with Systemtap.  It
> appears, though, that as of 2.6.27-rc8, markers defined in code which is
> compiled directly into the kernel (i.e., not as modules) don't show up
> in Module.markers:
>
> kvm_trace_entryexit arch/x86/kvm/kvm-intel  %u %p %u %u %u %u %u %u
> kvm_trace_handler arch/x86/kvm/kvm-intel  %u %p %u %u %u %u %u %u
> kvm_trace_entryexit arch/x86/kvm/kvm-amd  %u %p %u %u %u %u %u %u
> kvm_trace_handler arch/x86/kvm/kvm-amd  %u %p %u %u %u %u %u %u
>
> (Note the lack of any of the kernel_sched_* markers, and the markers I
> added for ext4_* and jbd2_* are missing as wel.)
>
> Systemtap apparently depends on in-kernel trace_mark being recorded in
> Module.markers, and apparently it's been claimed that it used to be
> there.  Is this a bug in systemtap, or in how Module.markers is getting
> built?   And is there a file that contains the equivalent information
> for markers located in non-modules code?

I think the problem comes from "markers: fix duplicate modpost entry"
(commit d35cb360)

Especially :

  -   add_marker(mod, marker, fmt);
  +   if (!mod->skip)
  +     add_marker(mod, marker, fmt);
    }
    return;
   fail:

Here is a fix that should take care if this problem.

Thanks for the bug report!
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Tested-by: "Theodore Ts'o" <tytso@mit.edu>
CC: Greg KH <greg@kroah.com>
CC: David Smith <dsmith@redhat.com>
CC: Roland McGrath <roland@redhat.com>
CC: Sam Ravnborg <sam@ravnborg.org>
CC: Wenji Huang <wenji.huang@oracle.com>
CC: Takashi Nishiie <t-nishiie@np.css.fujitsu.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb:
  kgdb: call touch_softlockup_watchdog on resume
  kgdb, x86: Avoid invoking kgdb_nmicallback twice per NMI

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: gart iommu have direct mapping when agp is present too

* git://git.kernel.org/pub/scm/linux/kernel/git/bart/ide-2.6:
  ide: workaround for bogus gcc warning in ide_sysfs_register_port()
  ide-cd: Optiarc DVD RW AD-7200A does play audio
  IDE: Fix platform device registration in Swarm IDE driver (v2)
  ide-dma: fix ide_build_dmatable() for TRM290
  ide-cd: temporary tray close fix

* 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus:
  [MIPS] IP27: Fix build errors if CONFIG_MAPPED_KERNEL=y
  [MIPS] Fix CMP Kconfig configuration and mark as broken.

* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/v4l-dvb: (33 commits)
  V4L/DVB (9103): em28xx: HVR-900 B3C0 - fix audio clicking issue
  V4L/DVB (9099): em28xx: Add detection for K-WORLD DVB-T 310U
  V4L/DVB (9092): gspca: Bad init values for sonixj ov7660.
  V4L/DVB (9080): gspca: Add a delay after writing to the sonixj sensors.
  V4L/DVB (9075): gspca: Bad check of returned status in i2c_read() spca561.
  V4L/DVB (9053): fix buffer overflow in uvc-video
  V4L/DVB (9043): S5H1420: Fix size of shadow-array to avoid overflow
  V4L/DVB (9037): Fix support for Hauppauge Nova-S SE
  V4L/DVB (9029): Fix deadlock in demux code
  V4L/DVB (8979): sms1xxx: Add new USB product ID for Hauppauge WinTV MiniStick
  V4L/DVB (8978): sms1xxx: fix product name for Hauppauge WinTV MiniStick
  V4L/DVB (8967): Use correct XC3028L firmware for AMD ATI TV Wonder 600
  V4L/DVB (8963): s2255drv field count fix
  V4L/DVB (8961): zr36067: Fix RGBR pixel format
  V4L/DVB (8960): drivers/media/video/cafe_ccic.c needs mm.h
  V4L/DVB (8958): zr36067: Return proper bytes-per-line value
  V4L/DVB (8957): zr36067: Restore the default pixel format
  V4L/DVB (8955): bttv: Prevent NULL pointer dereference in radio_open
  V4L/DVB (8935): em28xx-cards: Remove duplicate entry (EM2800_BOARD_KWORLD_USB2800)
  V4L/DVB (8933): gspca: Disable light frquency for zc3xx cs2102 Kokom.
  ...

The atmel-mci driver sometimes fails data transfers like this:

   mmcblk0: error -5 transferring data
   end_request: I/O error, dev mmcblk0, sector 2749769
   end_request: I/O error, dev mmcblk0, sector 2749777

It turns out that this might be caused by the BLKR register (which
contains the block size and the number of blocks being transfered) being
initialized too late. This patch moves the initialization of BLKR so
that it contains the correct value before the block transfer command is
sent.

This error is difficult to reproduce, but if you insert a long delay
(mdelay(10) or thereabouts) between the calls to atmci_start_command()
and atmci_submit_data(), all transfers seem to fail without this patch,
while I haven't seen any failures with this patch.
Reported-by: Hein_Tibosch <hein_tibosch@yahoo.es>
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

While debugging another bug it was found that NetRom socks
are sometimes seen unorphaned in sk_free(). This patch moves
sock_orphan() in nr_release() to the beginning (like in ax25,
or rose).
Reported-and-tested-by: Bernard Pidoux f6bvp <f6bvp@free.fr>
Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Since we reverted 30902dc3 ("ax25: Fix
std timer socket destroy handling.") we have to put some kind of fix
in to cure the issue whereby unaccepted connections do not get destroyed.

The approach used here is from Tihomir Heidelberg - 9a4gl
Signed-off-by: David S. Miller <davem@davemloft.net>

This reverts commit 30902dc3.

It causes all kinds of problems, based upon a report by
Bernard (f6bvp) and analysis by Jarek Poplawski.
Signed-off-by: David S. Miller <davem@davemloft.net>

The softlockup watchdog needs to be touched when resuming the from the
kgdb stopped state to avoid the printk that a CPU is stuck if the
debugger was active for longer than the softlockup threshold.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>

Stress-testing KVM's latest NMI support with kgdbts inside an SMP guest,
I came across spurious unhandled NMIs while running the singlestep test.
Looking closer at the code path each NMI takes when KGDB is enabled, I
noticed that kgdb_nmicallback is called twice per event: One time via
DIE_NMI_IPI notification, the second time on DIE_NMI. Removing the first
invocation cures the unhandled NMIs here.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>