Merge tag 'dm-3.17-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper changes from Mike Snitzer:

 - Allow the thin target to paired with any size external origin; also
   allow thin snapshots to be larger than the external origin.

 - Add support for quickly loading a repetitive pattern into the
   dm-switch target.

 - Use per-bio data in the dm-crypt target instead of always using a
   mempool for each allocation.  Required switching to kmalloc alignment
   for the bio slab.

 - Fix DM core to properly stack the QUEUE_FLAG_NO_SG_MERGE flag

 - Fix the dm-cache and dm-thin targets' export of the minimum_io_size
   to match the data block size -- this fixes an issue where mkfs.xfs
   would improperly infer raid striping was in place on the underlying
   storage.

 - Small cleanups in dm-io, dm-mpath and dm-cache

* tag 'dm-3.17-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm table: propagate QUEUE_FLAG_NO_SG_MERGE
  dm switch: efficiently support repetitive patterns
  dm switch: factor out switch_region_table_read
  dm cache: set minimum_io_size to cache's data block size
  dm thin: set minimum_io_size to pool's data block size
  dm crypt: use per-bio data
  block: use kmalloc alignment for bio slab
  dm table: make dm_table_supports_discards static
  dm cache metadata: use dm-space-map-metadata.h defined size limits
  dm cache: fail migrations in the do_worker error path
  dm cache: simplify deferred set reference count increments
  dm thin: relax external origin size constraints
  dm thin: switch to an atomic_t for tracking pending new block preparations
  dm mpath: eliminate pg_ready() wrapper
  dm io: simplify dec_count and sync_io

1 files changed, 12 insertions, 0 deletions

diff --git a/Documentation/device-mapper/switch.txt b/Documentation/device-mapper/switch.txt
index 2fa7493..8897d04 100644
--- a/Documentation/device-mapper/switch.txt
+++ b/Documentation/device-mapper/switch.txt
@@ -106,6 +106,11 @@ which paths.
     The path number in the range 0 ... (<num_paths> - 1).
     Expressed in hexadecimal (WITHOUT any prefix like 0x).
 
+R<n>,<m>
+    This parameter allows repetitive patterns to be loaded quickly. <n> and <m>
+    are hexadecimal numbers. The last <n> mappings are repeated in the next <m>
+    slots.
+
 Status
 ======
 
@@ -124,3 +129,10 @@ Create a switch device with 64kB region size:
 Set mappings for the first 7 entries to point to devices switch0, switch1,
 switch2, switch0, switch1, switch2, switch1:
     dmsetup message switch 0 set_region_mappings 0:0 :1 :2 :0 :1 :2 :1
+
+Set repetitive mapping. This command:
+    dmsetup message switch 0 set_region_mappings 1000:1 :2 R2,10
+is equivalent to:
+    dmsetup message switch 0 set_region_mappings 1000:1 :2 :1 :2 :1 :2 :1 :2 \
+	:1 :2 :1 :2 :1 :2 :1 :2 :1 :2
+