linux-toradex.git/include/linux/blkdev.h, branch v3.0-rc3

block: remove unwanted semicolons

2011-05-31T11:45:53+00:00

Since those defined functions require additional semicolon
from the caller, they could cause potential syntax errors
when used in if-else statements.

Signed-off-by: Namhyung Kim 
Acked-by: Martin K. Petersen 
Signed-off-by: Jens Axboe

Merge commit 'v2.6.39' into for-2.6.40/core

2011-05-20T18:33:15+00:00

Since for-2.6.40/core was forked off the 2.6.39 devel tree, we've
had churn in the core area that makes it difficult to handle
patches for eg cfq or blk-throttle. Instead of requiring that they
be based in older versions with bugs that have been fixed later
in the rc cycle, merge in 2.6.39 final.

Also fixes up conflicts in the below files.

Conflicts:
	drivers/block/paride/pcd.c
	drivers/cdrom/viocd.c
	drivers/ide/ide-cd.c

Signed-off-by: Jens Axboe

block: Fix discard topology stacking and reporting

2011-05-18T08:37:35+00:00

In some cases we would end up stacking discard_zeroes_data incorrectly.
Fix this by enabling the feature by default for stacking drivers and
clearing it for low-level drivers. Incorporating a device that does not
support dzd will then cause the feature to be disabled in the stacking
driver.

Also ensure that the maximum discard value does not overflow when
exported in sysfs and return 0 in the alignment and dzd fields for
devices that don't support discard.

Reported-by: Lukas Czerner 
Signed-off-by: Martin K. Petersen 
Acked-by: Mike Snitzer 
Cc: stable@kernel.org
Signed-off-by: Jens Axboe

block: hold queue if flush is running for non-queueable flush drive

2011-05-06T17:36:25+00:00

In some drives, flush requests are non-queueable. When flush request is
running, normal read/write requests can't run. If block layer dispatches
such request, driver can't handle it and requeue it.  Tejun suggested we
can hold the queue when flush is running. This can avoid unnecessary
requeue.  Also this can improve performance. For example, we have
request flush1, write1, flush 2. flush1 is dispatched, then queue is
hold, write1 isn't inserted to queue. After flush1 is finished, flush2
will be dispatched. Since disk cache is already clean, flush2 will be
finished very soon, so looks like flush2 is folded to flush1.

In my test, the queue holding completely solves a regression introduced by
commit 53d63e6b0dfb95882ec0219ba6bbd50cde423794:

    block: make the flush insertion use the tail of the dispatch list

    It's not a preempt type request, in fact we have to insert it
    behind requests that do specify INSERT_FRONT.

which causes about 20% regression running a sysbench fileio
workload.

Stable: 2.6.39 only

Cc: stable@kernel.org
Signed-off-by: Shaohua Li 
Acked-by: Tejun Heo 
Signed-off-by: Jens Axboe

block: add a non-queueable flush flag

2011-05-06T17:36:25+00:00

flush request isn't queueable in some drives. Add a flag to let driver
notify block layer about this. We can optimize flush performance with the
knowledge.

Stable: 2.6.39 only

Cc: stable@kernel.org
Signed-off-by: Shaohua Li 
Acked-by: Tejun Heo 
Signed-off-by: Jens Axboe

block: get rid of QUEUE_FLAG_REENTER

2011-04-19T11:32:46+00:00

We are currently using this flag to check whether it's safe
to call into ->request_fn(). If it is set, we punt to kblockd.
But we get a lot of false positives and excessive punts to
kblockd, which hurts performance.

The only real abuser of this infrastructure is SCSI. So export
the async queue run and convert SCSI over to use that. There's
room for improvement in that SCSI need not always use the async
call, but this fixes our performance issue and they can fix that
up in due time.

Signed-off-by: Jens Axboe

block: add blk_run_queue_async

2011-04-18T09:41:33+00:00

Instead of overloading __blk_run_queue to force an offload to kblockd
add a new blk_run_queue_async helper to do it explicitly.  I've kept
the blk_queue_stopped check for now, but I suspect it's not needed
as the check we do when the workqueue items runs should be enough.

Signed-off-by: Christoph Hellwig 
Signed-off-by: Jens Axboe

Revert "block: add callback function for unplug notification"

2011-04-18T07:54:05+00:00

MD can't use this since it really requires us to be able to
keep more than a single piece of state for the unplug. Commit
048c9374 added the required support for MD, so get rid of this
now unused code.

This reverts commit f75664570d8b75469cc468f23c2b27220984983b.

Conflicts:

	block/blk-core.c

Signed-off-by: Jens Axboe

block: Enhance new plugging support to support general callbacks

2011-04-18T07:52:22+00:00

md/raid requires an unplug callback, but as it does not uses
requests the current code cannot provide one.

So allow arbitrary callbacks to be attached to the blk_plug.

Signed-off-by: NeilBrown 
Signed-off-by: Jens Axboe

block: let io_schedule() flush the plug inline

2011-04-16T11:27:55+00:00

Linus correctly observes that the most important dispatch cases
are now done from kblockd, this isn't ideal for latency reasons.
The original reason for switching dispatches out-of-line was to
avoid too deep a stack, so by _only_ letting the "accidental"
flush directly in schedule() be guarded by offload to kblockd,
we should be able to get the best of both worlds.

So add a blk_schedule_flush_plug() that offloads to kblockd,
and only use that from the schedule() path.

Signed-off-by: Jens Axboe