• Linus Torvalds's avatar
    Merge tag 'md/4.1' of git://neil.brown.name/md · 474095e4
    Linus Torvalds authored
    Pull md updates from Neil Brown:
     "More updates that usual this time.  A few have performance impacts
      which hould mostly be positive, but RAID5 (in particular) can be very
      work-load ensitive...  We'll have to wait and see.
    
      Highlights:
    
       - "experimental" code for managing md/raid1 across a cluster using
         DLM.  Code is not ready for general use and triggers a WARNING if
         used.  However it is looking good and mostly done and having in
         mainline will help co-ordinate development.
    
       - RAID5/6 can now batch multiple (4K wide) stripe_heads so as to
         handle a full (chunk wide) stripe as a single unit.
    
       - RAID6 can now perform read-modify-write cycles which should help
         performance on larger arrays: 6 or more devices.
    
       - RAID5/6 stripe cache now grows and shrinks dynamically.  The value
         set is used as a minimum.
    
       - Resync is now allowed to go a little faster than the 'mininum' when
         there is competing IO.  How much faster depends on the speed of the
         devices, so the effective minimum should scale with device speed to
         some extent"
    
    * tag 'md/4.1' of git://neil.brown.name/md: (58 commits)
      md/raid5: don't do chunk aligned read on degraded array.
      md/raid5: allow the stripe_cache to grow and shrink.
      md/raid5: change ->inactive_blocked to a bit-flag.
      md/raid5: move max_nr_stripes management into grow_one_stripe and drop_one_stripe
      md/raid5: pass gfp_t arg to grow_one_stripe()
      md/raid5: introduce configuration option rmw_level
      md/raid5: activate raid6 rmw feature
      md/raid6 algorithms: xor_syndrome() for SSE2
      md/raid6 algorithms: xor_syndrome() for generic int
      md/raid6 algorithms: improve test program
      md/raid6 algorithms: delta syndrome functions
      raid5: handle expansion/resync case with stripe batching
      raid5: handle io error of batch list
      RAID5: batch adjacent full stripe write
      raid5: track overwrite disk count
      raid5: add a new flag to track if a stripe can be batched
      raid5: use flex_array for scribble data
      md raid0: access mddev->queue (request queue member) conditionally because it is not set when accessed from dm-raid
      md: allow resync to go faster when there is competing IO.
      md: remove 'go_faster' option from ->sync_request()
      ...
    474095e4
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