When devices are stacked, one device's merge_bvec_fn may need to perform
the mapping and then call one or more functions for its underlying devices.

The following bio fields are used:
  bio->bi_sector
  bio->bi_bdev
  bio->bi_size
  bio->bi_rw  using bio_data_dir()

This patch creates a new struct bvec_merge_data holding a copy of those
fields to avoid having to change them directly in the struct bio when
going down the stack only to have to change them back again on the way
back up.  (And then when the bio gets mapped for real, the whole
exercise gets repeated, but that's a problem for another day...)
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Cc: Neil Brown <neilb@suse.de>
Cc: Milan Broz <mbroz@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Just use normal open coded bit operations instead, they need not be
atomic.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

This patch adds the commands that the former sg filter allowed for read
access to the cmdfilter to keep userspace apps that rely on them working.
Signed-off-by: Adel Gadllah <adel.gadllah@gmail.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

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

blk_rq_map_user_iov can't handle the bounce buffer (it means that the
bio_map_user_iov path doesn't work with a LLD that needs GFP_DMA).

This patch fixes blk_rq_map_user_iov to support the bounce buffer.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

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

This patch exports the per-gendisk command filter to user space through
sysfs, so it can be changed by the system administrator.
All users of the old cmd filter have been converted to use the new one.

Original patch from Peter Jones.
Signed-off-by: Adel Gadllah <adel.gadllah@gmail.com>
Signed-off-by: Peter Jones <pjones@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

- No need to check for NULL bio, we'll get an immediate oops anyway.
- Make bio_integrity() a proper function.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

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

> 80 char lines and that sort of thing.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Some block devices support verifying the integrity of requests by way
of checksums or other protection information that is submitted along
with the I/O.

This patch implements support for generating and verifying integrity
metadata, as well as correctly merging, splitting and cloning bios and
requests that have this extra information attached.

See Documentation/block/data-integrity.txt for more information.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Move struct bio_set and biovec_slab definitions to bio.h so they can
be used outside of bio.c.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Avoid allocations causing swap activity on the resume path by
preventing the allocations from doing IO and allowing them
to access the emergency pools.

These paths are used when a frontend device is trying to connect
to its backend driver over Xenbus.  These reconnections are triggered
on demand by IO, so by definition there is already IO underway,
and further IO would naturally deadlock.  On resume, this path
is triggered when the running system tries to continue using its
devices.  If it cannot then the resume will fail; to try to avoid this
we let it dip into the emergency pools.

[ linux-2.6.18-xen changesets e8b49cfbdac, fdb998e79aba ]
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

[ linux-2.6.18-xen changeset c1c57fea77e9 ]
Signed-off-by: Wim Colgate <wim@xensource.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Return 0 instead of -EINVAL if the blkfront device is a cdrom,
i.e. had the VDISK_CDROM attribute.  This allows udev's cdrom_id
to correctly detect the device as a cdrom device.

[ Add blkif_ioctl, and CDROMMULTISESSION ]

[ linux-2.6.18-xen changeset d2bd9af846b5 ]
Signed-off-by: Christian Limpach <Christian.Limpach@xensource.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

[ linux-2.6.18-xen changeset 667228bf8fc5 ]
Signed-off-by: Ian Campbell <ian.campbell@xensource.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Everything was moved to struct request_queue a few kernel revisions
ago, maintaining the deprecated typedef to avoid breaking things.
Now the time has come to get rid of that typedef.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

This allows a user to annotate the blk trace stream: writing a suitable
message to {/sys/kernel/debug}/block/<dsf>/msg will have it propagated
into the trace stream.
Signed-off-by: Alan D. Brunelle <alan.brunelle@hp.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Now that blktrace has the ability to carry arbitrary messages in
its stream, use that for some CFQ logging.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

If we have multiple tasks freeing io contexts when as-iosched
is being unloaded, we could complete() ioc_gone twice. Fix that by
protecting ioc_gone complete() and clearing with a spinlock for
just that purpose. Doesn't matter from a performance perspective,
since it'll only enter that path when ioc_gone != NULL (when as-iosched
is being rmmod'ed).
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

If we have multiple tasks freeing cfq_io_contexts when cfq-iosched
is being unloaded, we could complete() ioc_gone twice. Fix that by
protecting ioc_gone complete() and clearing with a spinlock for
just that purpose. Doesn't matter from a performance perspective,
since it'll only enter that path when ioc_gone != NULL (when cfq-iosched
is being rmmod'ed).
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6:
  PCI: acpiphp: cleanup notify handler on all root bridges
  PCI: Limit VPD read/write lengths for Broadcom 5706, 5708, 5709 rev.
  PCI: Restrict VPD read permission to root

* 'i2c-fix' of git://aeryn.fluff.org.uk/bjdooks/linux:
  I2C: S3C2410: Add MODULE_ALIAS() for s3c2440 device.
  I2C: S3C2410: Fixup error codes returned rom a transfer.
  I2C: S3C2410: Check ACK on byte transmission

* 'for-2.6.26' of git://git.kernel.dk/linux-2.6-block:
  Properly notify block layer of sync writes
  block: Fix the starving writes bug in the anticipatory IO scheduler

* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6:
  [IA64] export account_system_vtime
  [IA64] Bugfix for system with 32 cpus

* git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/v4l-dvb:
  V4L/DVB (8178): uvc: Fix compilation breakage for the other drivers, if uvc is selected
  V4L/DVB (8145a): USB Video Class driver

* git://git.kernel.org/pub/scm/linux/kernel/git/bart/ide-2.6:
  ide: fix /proc/ide/ide?/mate reporting
  Revert "BAST: Remove old IDE driver"

* master.kernel.org:/home/rmk/linux-2.6-arm:
  [ARM] 5131/1: Annotate platform_secondary_init with trace_hardirqs_off
  [ARM] 5117/1: pxafb: fix __devinit/exit annotations
  [ARM] Export dma_sync_sg_for_device()
  [ARM] 5109/1: Mark rtc sa1100 driver as wakeup source before registering it
  [ARM] 5116/1: pxafb: cleanup and fix order of failure handling
  [ARM] 5115/1: pxafb: fix ifdef for command line option handling
  ARM: OMAP: Correcting the gpmc prefetch control register address
  ARM: OMAP: DMA: Don't mark channel active in omap_enable_channel_irq

Not sure how this came to get inverted but it appears to have been my
mess up.
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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: fix divide error when trying to configure rt_period to zero

* 'i2c-for-linus' of git://jdelvare.pck.nerim.net/jdelvare-2.6:
  i2c: Fix bad hint about irqs in i2c.h
  i2c: Documentation: fix device matching description

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

* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  rcu: fix hotplug vs rcu race

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: fix NODES_SHIFT Kconfig range

* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-rc-fixes-2.6:
  [SCSI] esp: tidy up target reference counting
  [SCSI] esp: Fix OOPS in esp_reset_cleanup().
  [SCSI] ses: Fix timeout

* git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dm:
  dm crypt: use cond_resched

* 'for-2.6.26' of git://neil.brown.name/md:
  Fix error paths if md_probe fails.
  Don't acknowlege that stripe-expand is complete until it really is.
  Ensure interrupted recovery completed properly (v1 metadata plus bitmap)

* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc:
  powerpc/mpc5200: Fix lite5200b suspend/resume
  powerpc/legacy_serial: Bail if reg-offset/shift properties are present
  powerpc/bootwrapper: update for initrd with simpleImage