linux-toradex.git/block/blk-settings.c, branch v3.6

block: do not artificially constrain max_sectors for stacking drivers

2012-08-01T08:44:28+00:00

blk_set_stacking_limits is intended to allow stacking drivers to build
up the limits of the stacked device based on the underlying devices'
limits.  But defaulting 'max_sectors' to BLK_DEF_MAX_SECTORS (1024)
doesn't allow the stacking driver to inherit a max_sectors larger than
1024 -- due to blk_stack_limits' use of min_not_zero.

It is now clear that this artificial limit is getting in the way so
change blk_set_stacking_limits's max_sectors to UINT_MAX (which allows
stacking drivers like dm-multipath to inherit 'max_sectors' from the
underlying paths).

Reported-by: Vijay Chauhan 
Tested-by: Vijay Chauhan 
Signed-off-by: Mike Snitzer 
Signed-off-by: Jens Axboe

block: Introduce blk_set_stacking_limits function

2012-01-11T15:27:11+00:00

Stacking driver queue limits are typically bounded exclusively by the
capabilities of the low level devices, not by the stacking driver
itself.

This patch introduces blk_set_stacking_limits() which has more liberal
metrics than the default queue limits function. This allows us to
inherit topology parameters from bottom devices without manually
tweaking the default limits in each driver prior to calling the stacking
function.

Since there is now a clear distinction between stacking and low-level
devices, blk_set_default_limits() has been modified to carry the more
conservative values that we used to manually set in
blk_queue_make_request().

Signed-off-by: Martin K. Petersen 
Acked-by: Mike Snitzer 
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: 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

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: add callback function for unplug notification

2011-04-12T08:17:31+00:00

MD would like to know when a queue is unplugged, so it can flush
it's bitmap writes. Add such a callback.

Signed-off-by: Jens Axboe

Merge branch 'for-2.6.39/stack-plug' into for-2.6.39/core

2011-03-10T07:58:35+00:00

Conflicts:
	block/blk-core.c
	block/blk-flush.c
	drivers/md/raid1.c
	drivers/md/raid10.c
	drivers/md/raid5.c
	fs/nilfs2/btnode.c
	fs/nilfs2/mdt.c

Signed-off-by: Jens Axboe

block: remove per-queue plugging

2011-03-10T07:52:07+00:00

Code has been converted over to the new explicit on-stack plugging,
and delay users have been converted to use the new API for that.
So lets kill off the old plugging along with aops->sync_page().

Signed-off-by: Jens Axboe

block: Initialize ->queue_lock to internal lock at queue allocation time

2011-03-03T00:06:49+00:00

There does not seem to be a clear convention whether q->queue_lock is
initialized or not when blk_cleanup_queue() is called. In the past it
was not necessary but now blk_throtl_exit() takes up queue lock by
default and needs queue lock to be available.

In fact elevator_exit() code also has similar requirement just that it
is less stringent in the sense that elevator_exit() is called only if
elevator is initialized.

Two problems have been noticed because of ambiguity about spin lock
status.

      - If a driver calls blk_alloc_queue() and then soon calls
        blk_cleanup_queue() almost immediately, (because some other
	driver structure allocation failed or some other error happened)
	then blk_throtl_exit() will run into issues as queue lock is not
	initialized. Loop driver ran into this issue recently and I
	noticed error paths in md driver too. Similar error paths should
	exist in other drivers too.

      - If some driver provided external spin lock and zapped the lock
        before blk_cleanup_queue(), then it can lead to issues.

So this patch initializes the default queue lock at queue allocation time.

block throttling code is one of the users of queue lock and it is
initialized at the queue allocation time, so it makes sense to
initialize ->queue_lock also to internal lock. A driver can overide that
lock later. This will take care of the issue where a driver does not have
to worry about initializing the queue lock to default before calling
blk_cleanup_queue()

Signed-off-by: Vivek Goyal 
Signed-off-by: Jens Axboe

block: max hardware sectors limit wrapper

2010-12-17T07:36:01+00:00

Implement blk_limits_max_hw_sectors() and make
blk_queue_max_hw_sectors() a wrapper around it.

DM needs this to avoid setting queue_limits' max_hw_sectors and
max_sectors directly.  dm_set_device_limits() now leverages
blk_limits_max_hw_sectors() logic to establish the appropriate
max_hw_sectors minimum (PAGE_SIZE).  Fixes issue where DM was
incorrectly setting max_sectors rather than max_hw_sectors (which
caused dm_merge_bvec()'s max_hw_sectors check to be ineffective).

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