It can make sense to set read-ahead larger than a single request.
We should not be enforcing such policy on the user. Additionally,
using the BLKRASET ioctl doesn't impose such a restriction. So
additionally we now expose identical behaviour through the two.

Issue also reported by Anton <cbou@mail.ru>
Signed-off-by: NJens Axboe <axboe@suse.de>

Don't touch the current queues, just make sure that the wanted queue
is selected next. Simplifies the logic.
Signed-off-by: NJens Axboe <axboe@suse.de>

CFQ implements this on its own now, but it's really block layer
knowledge. Tells a device queue to start dispatching requests to
the driver, taking care to unplug if needed. Also fixes the issue
where as/cfq will invoke a stopped queue, which we really don't
want.
Signed-off-by: NJens Axboe <axboe@suse.de>

No point in having a place holder list just for empty queues, so remove
it. It's not used for anything other than to keep ->cfq_list busy.
Signed-off-by: NJens Axboe <axboe@suse.de>

Currently it scales with number of processes in that priority group,
which is potentially not very nice as it's called quite often.
Basically we always need to do tail inserts, except for the case of a
new process. So just mark/detect a queue as such.
Signed-off-by: NJens Axboe <axboe@suse.de>

Some were kmalloc_node(), some were still kmalloc(). Change them all to
kmalloc_node().
Signed-off-by: NJens Axboe <axboe@suse.de>

Signed-off-by: NJens Axboe <axboe@suse.de>

Kill a few inlines that bring in too much code to more than one location
Shrinks kernel text by about 300 bytes on 32-bit x86.
Signed-off-by: NJens Axboe <axboe@suse.de>

It's ok if the read path is a lot more costly, as long as inc/dec is
really cheap. The inc/dec will happen for each created/freed io context,
while the reading only happens when a disk queue exits.
Signed-off-by: NJens Axboe <axboe@suse.de>

It's ok if the read path is a lot more costly, as long as inc/dec is
really cheap. The inc/dec will happen for each created/freed io context,
while the reading only happens when a disk queue exits.
Signed-off-by: NJens Axboe <axboe@suse.de>

None of the in-kernel primitives for handling "atomic" counting seem
to be a good fit. We need something that is essentially free for
incrementing/decrementing, while the read side may be more expensive
as we only ever need to do that when a device is removed from the
kernel.

Use a per-cpu variable for maintaining a per-cpu ioc count and define
a reading mechanism that just sums up the values.
Signed-off-by: NJens Axboe <axboe@suse.de>

cfq_exit_lock is protecting two things now:

- The per-ioc rbtree of cfq_io_contexts

- The per-cfqd linked list of cfq_io_contexts

The per-cfqd linked list can be protected by the queue lock, as it is (by
definition) per cfqd as the queue lock is.

The per-ioc rbtree is mainly used and updated by the process itself only.
The only outside use is the io priority changing. If we move the
priority changing to not browsing the rbtree, we can remove any locking
from the rbtree updates and lookup completely. Let the sys_ioprio syscall
just mark processes as having the iopriority changed and lazily update
the private cfq io contexts the next time io is queued, and we can
remove this locking as well.
Signed-off-by: NJens Axboe <axboe@suse.de>

A collection of little fixes and cleanups:

- We don't use the 'queued' sysfs exported attribute, since the
  may_queue() logic was rewritten. So kill it.

- Remove dead defines.

- cfq_set_active_queue() can be rewritten cleaner with else if conditions.

- Several places had cfq_exit_cfqq() like logic, abstract that out and
  use that.

- Annotate the cfqq kmem_cache_alloc() so the allocator knows that this
  is a repeat allocation if it fails with __GFP_WAIT set. Allows the
  allocator to start freeing some memory, if needed. CFQ already loops for
  this condition, so might as well pass the hint down.

- Remove cfqd->rq_starved logic. It's not needed anymore after we dropped
  the crq allocation in cfq_set_request().

- Remove uneeded parameter passing.
Signed-off-by: NJens Axboe <axboe@suse.de>

Move some members around and unionize completion_data and rb_node since
they cannot ever be used at the same time.
Signed-off-by: NJens Axboe <axboe@suse.de>

- Don't assign variables that are only used once.

- Kill spin_lock() prefetching, it's opportunistic at best.
Signed-off-by: NJens Axboe <axboe@suse.de>

It's not needed for anything, so kill the bio passing.
Signed-off-by: NJens Axboe <axboe@suse.de>

After Christophs SCSI change, the only usage left is RQ_ACTIVE
and RQ_INACTIVE. The block layer sets RQ_INACTIVE right before freeing
the request, so any check for RQ_INACTIVE in a driver is a bug and
indicates use-after-free.

So kill/clean the remaining users, straight forward.
Signed-off-by: NJens Axboe <axboe@suse.de>

It is always identical to &q->rq, and we only use it for detecting
whether this request came out of our mempool or not. So replace it
with an additional ->flags bit flag.
Signed-off-by: NJens Axboe <axboe@suse.de>

As the comments indicates in blkdev.h, we can fold it into ->end_io_data
usage as that is really what ->waiting is. Fixup the users of
blk_end_sync_rq().
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Get rid of the as_rq request type. With the added elevator_private2, we
have enough room in struct request to get rid of any arq allocation/free
for each request.
Signed-off-by: NJens Axboe <axboe@suse.de>
Signed-off-by: NNick Piggin <npiggin@suse.de>

Get rid of the cfq_rq request type. With the added elevator_private2, we
have enough room in struct request to get rid of any crq allocation/free
for each request.
Signed-off-by: NJens Axboe <axboe@suse.de>

Then we have enough room in the request to get rid of the dynamic
allocations in CFQ/AS.
Signed-off-by: NJens Axboe <axboe@suse.de>

There's just one flag currently (SYNC), and that one can be grabbed from
the request.
Signed-off-by: NJens Axboe <axboe@suse.de>

A big win, we now save an allocation/free on each request! With the
previous rb/hash abstractions, we can just reuse queuelist/donelist
for the FIFO data and be done with it.
Signed-off-by: NJens Axboe <axboe@suse.de>

We can track this in struct request.
Signed-off-by: NJens Axboe <axboe@suse.de>
Signed-off-by: NNick Piggin <npiggin@suse.de>

Saves some space in arq.
Signed-off-by: NJens Axboe <axboe@suse.de>
Signed-off-by: NNick Piggin <npiggin@suse.de>

Signed-off-by: NJens Axboe <axboe@suse.de>

The io schedulers can use this instead of having to allocate space for
it themselves.
Signed-off-by: NJens Axboe <axboe@suse.de>

This removes the rbtree handling from deadline.
Signed-off-by: NJens Axboe <axboe@suse.de>

This removes the rbtree handling from CFQ.
Signed-off-by: NJens Axboe <axboe@suse.de>

This removes the rbtree handling from AS.
Signed-off-by: NJens Axboe <axboe@suse.de>
Signed-off-by: NNick Piggin <npiggin@suse.de>

The rbtree sort/lookup/reposition logic is mostly duplicated in
cfq/deadline/as, so move it to the elevator core. The io schedulers
still provide the actual rb root, as we don't want to impose any sort
of specific handling on the schedulers.

Introduce the helpers and rb_node in struct request to help migrate the
IO schedulers.
Signed-off-by: NJens Axboe <axboe@suse.de>

The conditions got reserved. Also make rb_next() and rb_prev() check
for the empty condition.
Signed-off-by: NJens Axboe <axboe@suse.de>

Right now, every IO scheduler implements its own backmerging (except for
noop, which does no merging). That results in duplicated code for
essentially the same operation, which is never a good thing. This patch
moves the backmerging out of the io schedulers and into the elevator
core. We save 1.6kb of text and as a bonus get backmerging for noop as
well. Win-win!
Signed-off-by: NJens Axboe <axboe@suse.de>

Right now ->flags is a bit of a mess: some are request types, and
others are just modifiers. Clean this up by splitting it into
->cmd_type and ->cmd_flags. This allows introduction of generic
Linux block message types, useful for sending generic Linux commands
to block devices.
Signed-off-by: NJens Axboe <axboe@suse.de>

Delay the call to adapter->client_register() until after we are
certain that the client registration is a success. At this point the
client is fully initialized and we no longer hold the adapter->clist
mutex, so this should prevent the deadlocks if the client_register()
callback needs to take that mutex too, as is the case for the bttv
driver.

This fixes bug #7234.
Signed-off-by: NJean Delvare <khali@linux-fr.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

* master.kernel.org:/pub/scm/linux/kernel/git/mchehab/v4l-dvb: (180 commits)
  V4L/DVB (4641): Trivial: use lowercase letters in hex subsystem ids
  V4L/DVB (4639): Cx88: add autodetection for alternate revision of Leadtek PVR
  V4L/DVB (4638): Basic DVB-T and analog TV support for the HVR1300.
  V4L/DVB (4637): Add a default method for VIDIOC_G_PARM
  V4L/DVB (4635): Extend bttv and saa7134 to check for both AGP and PCI PCI failure case
  V4L/DVB (4634): Zr36120: implement pcipci checks
  V4L/DVB (4632): Zoran: Implement pcipci failure check
  V4L/DVB (4631): Av7110: remove V4L2_CAP_VBI_CAPTURE flag
  V4L/DVB (4630): Av7110: FW_LOADER depemdency fixed
  V4L/DVB (4629): Saa7134: add card support for Proteus Pro 2309
  V4L/DVB (4628): Fix VIDIOC_ENUMSTD ioctl in videodev.c
  V4L/DVB (4627): Vivi crashes with mplayer
  V4L/DVB (4626): On saa7111/7113, LUMA_CTRL need a different value
  V4L/DVB (4624): Tvaudio: Replaced kernel_thread() with kthread_run()
  V4L/DVB (4622): Copy-paste bug in videodev.c
  V4L/DVB (4620): Fix AGC configuration for MOD3000P-based boards
  V4L/DVB (4619): Fixes some I2C dependencies on V4L devices
  V4L/DVB (4617): Problem with dibusb-mb.c USB IDs
  V4L/DVB (4616): [PATCH] Nebula DigiTV USB RC support
  V4L/DVB (4614): Export symbol saa7134_tvaudio_setmute from saa7134 for saa7134-alsa
  ...

Merge branch 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6

* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6: (48 commits)
  ieee1394: raw1394: arm functions slept in atomic context
  ieee1394: sbp2: enable auto spin-up for all SBP-2 devices
  MAINTAINERS: updates to IEEE 1394 subsystem maintainership
  ieee1394: ohci1394: check for errors in suspend or resume
  set power state of firewire host during suspend
  ieee1394: ohci1394: more obvious endianess handling
  ieee1394: ohci1394: fix endianess bug in debug message
  ieee1394: sbp2: don't prefer MODE SENSE 10
  ieee1394: nodemgr: grab class.subsys.rwsem in nodemgr_resume_ne
  ieee1394: nodemgr: fix rwsem recursion
  ieee1394: sbp2: more help in Kconfig
  ieee1394: sbp2: prevent rare deadlock in shutdown
  ieee1394: sbp2: update includes
  ieee1394: sbp2: better handling of transport errors
  ieee1394: sbp2: recheck node generation in sbp2_update
  ieee1394: sbp2: safer agent reset in error handlers
  ieee1394: sbp2: handle "sbp2util_node_write_no_wait failed"
  CONFIG_PM=n slim: drivers/ieee1394/ohci1394.c
  ieee1394: safer definition of empty macros
  video1394: add poll file operation support
  ...

* 'intelfb-patches' of master.kernel.org:/pub/scm/linux/kernel/git/airlied/intelfb-2.6:
  intelfbhw.c: intelfbhw_get_p1p2 defined but not used
  intelfb: fix mtrr_reg signedness
  intelfb: update doc and Kconfig (supported devices)
  intelfb: add preliminary i2c support
  intelfb: add preliminary i2c support
  intelfb: add preliminary i2c support
  intelfb: add preliminary i2c support
  intelfb: add preliminary i2c support
  intelfb: add preliminary i2c support
  intelfb: add preliminary i2c support
  intelfb: add preliminary i2c support
  intelfb: add vsync interrupt support
  intelfb: add vsync interrupt support
  intelfb: add vsync interrupt support
  intelfb: add vsync interrupt support
  intelfb: add vsync interrupt support

* 'for-linus' of git://one.firstfloor.org/home/andi/git/linux-2.6:
  [PATCH] Use early clobber in semaphores
  [PATCH] Define vsyscall cache as blob to make clearer that user space shouldn't use it
  [PATCH] Re-positioning the bss segment
  [PATCH] Use ARRAY_SIZE in setup.c
  [PATCH] i386: replace intermediate array-size definitions with ARRAY_SIZE()
  [PATCH] x86: Clean up x86 NMI sysctls
  [PATCH] Refactor some duplicated code in mpparse.c
  [PATCH] Document iommu=panic
  [PATCH] Fix broken indentation in iommu_setup
  [PATCH] Allow disabling DAC using command line options
  [PATCH] Add proper sparse __user casts to __copy_to_user_inatomic
  [PATCH] i386: Update defconfig
  [PATCH] Update defconfig