Merge tag 'dm-3.16-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper updates from Mike Snitzer:
 "This pull request is later than I'd have liked because I was waiting
  for some performance data to help finally justify sending the
  long-standing dm-crypt cpu scalability improvements upstream.

  Unfortunately we came up short, so those dm-crypt changes will
  continue to wait, but it seems we're not far off.

   . Add dm_accept_partial_bio interface to DM core to allow DM targets
     to only process a portion of a bio, the remainder being sent in the
     next bio.  This enables the old dm snapshot-origin target to only
     split write bios on chunk boundaries, read bios are now sent to the
     origin device unchanged.

   . Add DM core support for disabling WRITE SAME if the underlying SCSI
     layer disables it due to command failure.

   . Reduce lock contention in DM's bio-prison.

   . A few small cleanups and fixes to dm-thin and dm-era"

* tag 'dm-3.16-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm thin: update discard_granularity to reflect the thin-pool blocksize
  dm bio prison: implement per bucket locking in the dm_bio_prison hash table
  dm: remove symbol export for dm_set_device_limits
  dm: disable WRITE SAME if it fails
  dm era: check for a non-NULL metadata object before closing it
  dm thin: return ENOSPC instead of EIO when error_if_no_space enabled
  dm thin: cleanup noflush_work to use a proper completion
  dm snapshot: do not split read bios sent to snapshot-origin target
  dm snapshot: allocate a per-target structure for snapshot-origin target
  dm: introduce dm_accept_partial_bio
  dm: change sector_count member in clone_info from sector_t to unsigned

include/linux/device-mapper.h

@@ -115,12 +115,6 @@ typedef int (*dm_busy_fn) (struct dm_target *ti);
 
 void dm_error(const char *message);
 
-/*
- * Combine device limits.
- */
-int dm_set_device_limits(struct dm_target *ti, struct dm_dev *dev,
-			 sector_t start, sector_t len, void *data);
-
 struct dm_dev {
 	struct block_device *bdev;
 	fmode_t mode;
@@ -132,7 +126,7 @@ struct dm_dev {
  * are opened/closed correctly.
  */
 int dm_get_device(struct dm_target *ti, const char *path, fmode_t mode,
-						 struct dm_dev **result);
+		  struct dm_dev **result);
 void dm_put_device(struct dm_target *ti, struct dm_dev *d);
 
 /*
@@ -291,6 +285,7 @@ struct dm_target_io {
 	struct dm_io *io;
 	struct dm_target *ti;
 	unsigned target_bio_nr;
+	unsigned *len_ptr;
 	struct bio clone;
 };
 
@@ -401,6 +396,7 @@ int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid);
 struct gendisk *dm_disk(struct mapped_device *md);
 int dm_suspended(struct dm_target *ti);
 int dm_noflush_suspending(struct dm_target *ti);
+void dm_accept_partial_bio(struct bio *bio, unsigned n_sectors);
 union map_info *dm_get_rq_mapinfo(struct request *rq);
 
 struct queue_limits *dm_get_queue_limits(struct mapped_device *md);