Merge branch 'for-3.7/core' of git://git.kernel.dk/linux-block

Pull block IO update from Jens Axboe:
 "Core block IO bits for 3.7.  Not a huge round this time, it contains:

   - First series from Kent cleaning up and generalizing bio allocation
     and freeing.

   - WRITE_SAME support from Martin.

   - Mikulas patches to prevent O_DIRECT crashes when someone changes
     the block size of a device.

   - Make bio_split() work on data-less bio's (like trim/discards).

   - A few other minor fixups."

Fixed up silent semantic mis-merge as per Mikulas Patocka and Andrew
Morton.  It is due to the VM no longer using a prio-tree (see commit
6b2dbba8b6ac: "mm: replace vma prio_tree with an interval tree").

So make set_blocksize() use mapping_mapped() instead of open-coding the
internal VM knowledge that has changed.

* 'for-3.7/core' of git://git.kernel.dk/linux-block: (26 commits)
  block: makes bio_split support bio without data
  scatterlist: refactor the sg_nents
  scatterlist: add sg_nents
  fs: fix include/percpu-rwsem.h export error
  percpu-rw-semaphore: fix documentation typos
  fs/block_dev.c:1644:5: sparse: symbol 'blkdev_mmap' was not declared
  blockdev: turn a rw semaphore into a percpu rw semaphore
  Fix a crash when block device is read and block size is changed at the same time
  block: fix request_queue->flags initialization
  block: lift the initial queue bypass mode on blk_register_queue() instead of blk_init_allocated_queue()
  block: ioctl to zero block ranges
  block: Make blkdev_issue_zeroout use WRITE SAME
  block: Implement support for WRITE SAME
  block: Consolidate command flag and queue limit checks for merges
  block: Clean up special command handling logic
  block/blk-tag.c: Remove useless kfree
  block: remove the duplicated setting for congestion_threshold
  block: reject invalid queue attribute values
  block: Add bio_clone_bioset(), bio_clone_kmalloc()
  block: Consolidate bio_alloc_bioset(), bio_kmalloc()
  ...

1 files changed, 14 insertions, 0 deletions

diff --git a/Documentation/ABI/testing/sysfs-block b/Documentation/ABI/testing/sysfs-block
index c1eb41cb9876..279da08f7541 100644
--- a/Documentation/ABI/testing/sysfs-block
+++ b/Documentation/ABI/testing/sysfs-block
@@ -206,3 +206,17 @@ Description:
 		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.
+
+What:		/sys/block/<disk>/queue/write_same_max_bytes
+Date:		January 2012
+Contact:	Martin K. Petersen <martin.petersen@oracle.com>
+Description:
+		Some devices support a write same operation in which a
+		single data block can be written to a range of several
+		contiguous blocks on storage. This can be used to wipe
+		areas on disk or to initialize drives in a RAID
+		configuration. write_same_max_bytes indicates how many
+		bytes can be written in a single write same command. If
+		write_same_max_bytes is 0, write same is not supported
+		by the device.
+