Merge branch 'for-2.6.40/core' of git://git.kernel.dk/linux-2.6-block

* 'for-2.6.40/core' of git://git.kernel.dk/linux-2.6-block: (40 commits)
  cfq-iosched: free cic_index if cfqd allocation fails
  cfq-iosched: remove unused 'group_changed' in cfq_service_tree_add()
  cfq-iosched: reduce bit operations in cfq_choose_req()
  cfq-iosched: algebraic simplification in cfq_prio_to_maxrq()
  blk-cgroup: Initialize ioc->cgroup_changed at ioc creation time
  block: move bd_set_size() above rescan_partitions() in __blkdev_get()
  block: call elv_bio_merged() when merged
  cfq-iosched: Make IO merge related stats per cpu
  cfq-iosched: Fix a memory leak of per cpu stats for root group
  backing-dev: Kill set but not used var in  bdi_debug_stats_show()
  block: get rid of on-stack plugging debug checks
  blk-throttle: Make no throttling rule group processing lockless
  blk-cgroup: Make cgroup stat reset path blkg->lock free for dispatch stats
  blk-cgroup: Make 64bit per cpu stats safe on 32bit arch
  blk-throttle: Make dispatch stats per cpu
  blk-throttle: Free up a group only after one rcu grace period
  blk-throttle: Use helper function to add root throtl group to lists
  blk-throttle: Introduce a helper function to fill in device details
  blk-throttle: Dynamically allocate root group
  blk-cgroup: Allow sleeping while dynamically allocating a group
  ...

1 files changed, 64 insertions, 0 deletions

diff --git a/Documentation/ABI/testing/sysfs-block b/Documentation/ABI/testing/sysfs-block
index 4873c759d53..c1eb41cb987 100644
--- a/Documentation/ABI/testing/sysfs-block
+++ b/Documentation/ABI/testing/sysfs-block
@@ -142,3 +142,67 @@ Description:
 		with the previous I/O request are enabled. When set to 2,
 		all merge tries are disabled. The default value is 0 -
 		which enables all types of merge tries.
+
+What:		/sys/block/<disk>/discard_alignment
+Date:		May 2011
+Contact:	Martin K. Petersen <martin.petersen@oracle.com>
+Description:
+		Devices that support discard functionality may
+		internally allocate space in units that are bigger than
+		the exported logical block size. The discard_alignment
+		parameter indicates how many bytes the beginning of the
+		device is offset from the internal allocation unit's
+		natural alignment.
+
+What:		/sys/block/<disk>/<partition>/discard_alignment
+Date:		May 2011
+Contact:	Martin K. Petersen <martin.petersen@oracle.com>
+Description:
+		Devices that support discard functionality may
+		internally allocate space in units that are bigger than
+		the exported logical block size. The discard_alignment
+		parameter indicates how many bytes the beginning of the
+		partition is offset from the internal allocation unit's
+		natural alignment.
+
+What:		/sys/block/<disk>/queue/discard_granularity
+Date:		May 2011
+Contact:	Martin K. Petersen <martin.petersen@oracle.com>
+Description:
+		Devices that support discard functionality may
+		internally allocate space using units that are bigger
+		than the logical block size. The discard_granularity
+		parameter indicates the size of the internal allocation
+		unit in bytes if reported by the device. Otherwise the
+		discard_granularity will be set to match the device's
+		physical block size. A discard_granularity of 0 means
+		that the device does not support discard functionality.
+
+What:		/sys/block/<disk>/queue/discard_max_bytes
+Date:		May 2011
+Contact:	Martin K. Petersen <martin.petersen@oracle.com>
+Description:
+		Devices that support discard functionality may have
+		internal limits on the number of bytes that can be
+		trimmed or unmapped in a single operation. Some storage
+		protocols also have inherent limits on the number of
+		blocks that can be described in a single command. The
+		discard_max_bytes parameter is set by the device driver
+		to the maximum number of bytes that can be discarded in
+		a single operation. Discard requests issued to the
+		device must not exceed this limit. A discard_max_bytes
+		value of 0 means that the device does not support
+		discard functionality.
+
+What:		/sys/block/<disk>/queue/discard_zeroes_data
+Date:		May 2011
+Contact:	Martin K. Petersen <martin.petersen@oracle.com>
+Description:
+		Devices that support discard functionality may return
+		stale or random data when a previously discarded block
+		is read back. This can cause problems if the filesystem
+		expects discarded blocks to be explicitly cleared. If a
+		device reports that it deterministically returns zeroes
+		when a discarded area is read the discard_zeroes_data
+		parameter will be set to one. Otherwise it will be 0 and
+		the result of reading a discarded area is undefined.