Merge branch 'for-next' of git://neil.brown.name/md

Pull md updates from NeilBrown.

* 'for-next' of git://neil.brown.name/md:
  DM RAID: Add support for MD RAID10
  md/RAID1: Add missing case for attempting to repair known bad blocks.
  md/raid5: For odirect-write performance, do not set STRIPE_PREREAD_ACTIVE.
  md/raid1: don't abort a resync on the first badblock.
  md: remove duplicated test on ->openers when calling do_md_stop()
  raid5: Add R5_ReadNoMerge flag which prevent bio from merging at block layer
  md/raid1: prevent merging too large request
  md/raid1: read balance chooses idlest disk for SSD
  md/raid1: make sequential read detection per disk based
  MD RAID10: Export md_raid10_congested
  MD: Move macros from raid1*.h to raid1*.c
  MD RAID1: rename mirror_info structure
  MD RAID10: rename mirror_info structure
  MD RAID10: Fix compiler warning.
  raid5: add a per-stripe lock
  raid5: remove unnecessary bitmap write optimization
  raid5: lockless access raid5 overrided bi_phys_segments
  raid5: reduce chance release_stripe() taking device_lock

1 files changed, 26 insertions, 0 deletions

diff --git a/Documentation/device-mapper/dm-raid.txt b/Documentation/device-mapper/dm-raid.txt
index 946c73342cde..1c1844957166 100644
--- a/Documentation/device-mapper/dm-raid.txt
+++ b/Documentation/device-mapper/dm-raid.txt
@@ -27,6 +27,10 @@ The target is named "raid" and it accepts the following parameters:
                 - rotating parity N (right-to-left) with data restart
   raid6_nc      RAID6 N continue
                 - rotating parity N (right-to-left) with data continuation
+  raid10        Various RAID10 inspired algorithms chosen by additional params
+                - RAID10: Striped Mirrors (aka 'Striping on top of mirrors')
+                - RAID1E: Integrated Adjacent Stripe Mirroring
+                -  and other similar RAID10 variants
 
   Reference: Chapter 4 of
   http://www.snia.org/sites/default/files/SNIA_DDF_Technical_Position_v2.0.pdf
@@ -59,6 +63,28 @@ The target is named "raid" and it accepts the following parameters:
                 logical size of the array.  The bitmap records the device
                 synchronisation state for each region.
 
+        [raid10_copies   <# copies>]
+        [raid10_format   near]
+                These two options are used to alter the default layout of
+                a RAID10 configuration.  The number of copies is can be
+                specified, but the default is 2.  There are other variations
+                to how the copies are laid down - the default and only current
+                option is "near".  Near copies are what most people think of
+                with respect to mirroring.  If these options are left
+                unspecified, or 'raid10_copies 2' and/or 'raid10_format near'
+                are given, then the layouts for 2, 3 and 4 devices are:
+                2 drives         3 drives          4 drives
+                --------         ----------        --------------
+                A1  A1           A1  A1  A2        A1  A1  A2  A2
+                A2  A2           A2  A3  A3        A3  A3  A4  A4
+                A3  A3           A4  A4  A5        A5  A5  A6  A6
+                A4  A4           A5  A6  A6        A7  A7  A8  A8
+                ..  ..           ..  ..  ..        ..  ..  ..  ..
+                The 2-device layout is equivalent 2-way RAID1.  The 4-device
+                layout is what a traditional RAID10 would look like.  The
+                3-device layout is what might be called a 'RAID1E - Integrated
+                Adjacent Stripe Mirroring'.
+
 <#raid_devs>: The number of devices composing the array.
         Each device consists of two entries.  The first is the device
         containing the metadata (if any); the second is the one containing the