1. 30 8月, 2009 11 次提交
    • D
      md/raid6: asynchronous raid6 operations · ac6b53b6
      Dan Williams 提交于
      [ Based on an original patch by Yuri Tikhonov ]
      
      The raid_run_ops routine uses the asynchronous offload api and
      the stripe_operations member of a stripe_head to carry out xor+pq+copy
      operations asynchronously, outside the lock.
      
      The operations performed by RAID-6 are the same as in the RAID-5 case
      except for no support of STRIPE_OP_PREXOR operations. All the others
      are supported:
      STRIPE_OP_BIOFILL
       - copy data into request buffers to satisfy a read request
      STRIPE_OP_COMPUTE_BLK
       - generate missing blocks (1 or 2) in the cache from the other blocks
      STRIPE_OP_BIODRAIN
       - copy data out of request buffers to satisfy a write request
      STRIPE_OP_RECONSTRUCT
       - recalculate parity for new data that has entered the cache
      STRIPE_OP_CHECK
       - verify that the parity is correct
      
      The flow is the same as in the RAID-5 case, and reuses some routines, namely:
      1/ ops_complete_postxor (renamed to ops_complete_reconstruct)
      2/ ops_complete_compute (updated to set up to 2 targets uptodate)
      3/ ops_run_check (renamed to ops_run_check_p for xor parity checks)
      
      [neilb@suse.de: fixes to get it to pass mdadm regression suite]
      Reviewed-by: NAndre Noll <maan@systemlinux.org>
      Signed-off-by: NYuri Tikhonov <yur@emcraft.com>
      Signed-off-by: NIlya Yanok <yanok@emcraft.com>
      Signed-off-by: NDan Williams <dan.j.williams@intel.com>
      
      
      
      ac6b53b6
    • D
      md/raid5: factor out mark_uptodate from ops_complete_compute5 · 4e7d2c0a
      Dan Williams 提交于
      ops_complete_compute5 can be reused in the raid6 path if it is updated to
      generically handle a second target.
      Signed-off-by: NDan Williams <dan.j.williams@intel.com>
      4e7d2c0a
    • D
      async_tx: raid6 recovery self test · cb3c8299
      Dan Williams 提交于
      Port drivers/md/raid6test/test.c to use the async raid6 recovery
      routines.  This is meant as a unit test for raid6 acceleration drivers.  In
      addition to the 16-drive test case this implements tests for the 4-disk and
      5-disk special cases (dma devices can not generically handle less than 2
      sources), and adds a test for the D+Q case.
      Reviewed-by: NAndre Noll <maan@systemlinux.org>
      Acked-by: NMaciej Sosnowski <maciej.sosnowski@intel.com>
      Signed-off-by: NDan Williams <dan.j.williams@intel.com>
      
      cb3c8299
    • D
      dmatest: add pq support · 58691d64
      Dan Williams 提交于
      Test raid6 p+q operations with a simple "always multiply by 1" q
      calculation to fit into dmatest's current destination verification
      scheme.
      Reviewed-by: NAndre Noll <maan@systemlinux.org>
      Acked-by: NMaciej Sosnowski <maciej.sosnowski@intel.com>
      Signed-off-by: NDan Williams <dan.j.williams@intel.com>
      
      58691d64
    • D
      async_tx: add support for asynchronous RAID6 recovery operations · 0a82a623
      Dan Williams 提交于
       async_raid6_2data_recov() recovers two data disk failures
      
       async_raid6_datap_recov() recovers a data disk and the P disk
      
      These routines are a port of the synchronous versions found in
      drivers/md/raid6recov.c.  The primary difference is breaking out the xor
      operations into separate calls to async_xor.  Two helper routines are
      introduced to perform scalar multiplication where needed.
      async_sum_product() multiplies two sources by scalar coefficients and
      then sums (xor) the result.  async_mult() simply multiplies a single
      source by a scalar.
      
      This implemention also includes, in contrast to the original
      synchronous-only code, special case handling for the 4-disk and 5-disk
      array cases.  In these situations the default N-disk algorithm will
      present 0-source or 1-source operations to dma devices.  To cover for
      dma devices where the minimum source count is 2 we implement 4-disk and
      5-disk handling in the recovery code.
      
      [ Impact: asynchronous raid6 recovery routines for 2data and datap cases ]
      
      Cc: Yuri Tikhonov <yur@emcraft.com>
      Cc: Ilya Yanok <yanok@emcraft.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: David Woodhouse <David.Woodhouse@intel.com>
      Reviewed-by: NAndre Noll <maan@systemlinux.org>
      Acked-by: NMaciej Sosnowski <maciej.sosnowski@intel.com>
      Signed-off-by: NDan Williams <dan.j.williams@intel.com>
      
      0a82a623
    • D
      async_tx: add support for asynchronous GF multiplication · b2f46fd8
      Dan Williams 提交于
      [ Based on an original patch by Yuri Tikhonov ]
      
      This adds support for doing asynchronous GF multiplication by adding
      two additional functions to the async_tx API:
      
       async_gen_syndrome() does simultaneous XOR and Galois field
          multiplication of sources.
      
       async_syndrome_val() validates the given source buffers against known P
          and Q values.
      
      When a request is made to run async_pq against more than the hardware
      maximum number of supported sources we need to reuse the previous
      generated P and Q values as sources into the next operation.  Care must
      be taken to remove Q from P' and P from Q'.  For example to perform a 5
      source pq op with hardware that only supports 4 sources at a time the
      following approach is taken:
      
      p, q = PQ(src0, src1, src2, src3, COEF({01}, {02}, {04}, {08}))
      p', q' = PQ(p, q, q, src4, COEF({00}, {01}, {00}, {10}))
      
      p' = p + q + q + src4 = p + src4
      q' = {00}*p + {01}*q + {00}*q + {10}*src4 = q + {10}*src4
      
      Note: 4 is the minimum acceptable maxpq otherwise we punt to
      synchronous-software path.
      
      The DMA_PREP_CONTINUE flag indicates to the driver to reuse p and q as
      sources (in the above manner) and fill the remaining slots up to maxpq
      with the new sources/coefficients.
      
      Note1: Some devices have native support for P+Q continuation and can skip
      this extra work.  Devices with this capability can advertise it with
      dma_set_maxpq.  It is up to each driver how to handle the
      DMA_PREP_CONTINUE flag.
      
      Note2: The api supports disabling the generation of P when generating Q,
      this is ignored by the synchronous path but is implemented by some dma
      devices to save unnecessary writes.  In this case the continuation
      algorithm is simplified to only reuse Q as a source.
      
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: David Woodhouse <David.Woodhouse@intel.com>
      Signed-off-by: NYuri Tikhonov <yur@emcraft.com>
      Signed-off-by: NIlya Yanok <yanok@emcraft.com>
      Reviewed-by: NAndre Noll <maan@systemlinux.org>
      Acked-by: NMaciej Sosnowski <maciej.sosnowski@intel.com>
      Signed-off-by: NDan Williams <dan.j.williams@intel.com>
      b2f46fd8
    • D
      async_tx: remove walk of tx->parent chain in dma_wait_for_async_tx · 95475e57
      Dan Williams 提交于
      We currently walk the parent chain when waiting for a given tx to
      complete however this walk may race with the driver cleanup routine.
      The routines in async_raid6_recov.c may fall back to the synchronous
      path at any point so we need to be prepared to call async_tx_quiesce()
      (which calls  dma_wait_for_async_tx).  To remove the ->parent walk we
      guarantee that every time a dependency is attached ->issue_pending() is
      invoked, then we can simply poll the initial descriptor until
      completion.
      
      This also allows for a lighter weight 'issue pending' implementation as
      there is no longer a requirement to iterate through all the channels'
      ->issue_pending() routines as long as operations have been submitted in
      an ordered chain.  async_tx_issue_pending() is added for this case.
      Signed-off-by: NDan Williams <dan.j.williams@intel.com>
      95475e57
    • D
      async_tx: kill needless module_{init|exit} · af1f951e
      Dan Williams 提交于
      If module_init and module_exit are nops then neither need to be defined.
      
      [ Impact: pure cleanup ]
      Reviewed-by: NAndre Noll <maan@systemlinux.org>
      Acked-by: NMaciej Sosnowski <maciej.sosnowski@intel.com>
      Signed-off-by: NDan Williams <dan.j.williams@intel.com>
      af1f951e
    • D
      async_tx: add sum check flags · ad283ea4
      Dan Williams 提交于
      Replace the flat zero_sum_result with a collection of flags to contain
      the P (xor) zero-sum result, and the soon to be utilized Q (raid6 reed
      solomon syndrome) zero-sum result.  Use the SUM_CHECK_ namespace instead
      of DMA_ since these flags will be used on non-dma-zero-sum enabled
      platforms.
      Reviewed-by: NAndre Noll <maan@systemlinux.org>
      Acked-by: NMaciej Sosnowski <maciej.sosnowski@intel.com>
      Signed-off-by: NDan Williams <dan.j.williams@intel.com>
      ad283ea4
    • D
      md/raid5,6: add percpu scribble region for buffer lists · d6f38f31
      Dan Williams 提交于
      Use percpu memory rather than stack for storing the buffer lists used in
      parity calculations.  Include space for dma address conversions and pass
      that to async_tx via the async_submit_ctl.scribble pointer.
      
      [ Impact: move memory pressure from stack to heap ]
      Signed-off-by: NDan Williams <dan.j.williams@intel.com>
      
      
      d6f38f31
    • D
      md/raid6: move the spare page to a percpu allocation · 36d1c647
      Dan Williams 提交于
      In preparation for asynchronous handling of raid6 operations move the
      spare page to a percpu allocation to allow multiple simultaneous
      synchronous raid6 recovery operations.
      
      Make this allocation cpu hotplug aware to maximize allocation
      efficiency.
      Signed-off-by: NDan Williams <dan.j.williams@intel.com>
      
      
      36d1c647
  2. 15 7月, 2009 1 次提交
  3. 04 6月, 2009 3 次提交
    • D
      async_xor: permit callers to pass in a 'dma/page scribble' region · 04ce9ab3
      Dan Williams 提交于
      async_xor() needs space to perform dma and page address conversions.  In
      most cases the code can simply reuse the struct page * array because the
      size of the native pointer matches the size of a dma/page address.  In
      order to support archs where sizeof(dma_addr_t) is larger than
      sizeof(struct page *), or to preserve the input parameters, we utilize a
      memory region passed in by the caller.
      
      Since the code is now prepared to handle the case where it cannot
      perform address conversions on the stack, we no longer need the
      !HIGHMEM64G dependency in drivers/dma/Kconfig.
      
      [ Impact: don't clobber input buffers for address conversions ]
      Reviewed-by: NAndre Noll <maan@systemlinux.org>
      Acked-by: NMaciej Sosnowski <maciej.sosnowski@intel.com>
      Signed-off-by: NDan Williams <dan.j.williams@intel.com>
      04ce9ab3
    • D
      async_tx: structify submission arguments, add scribble · a08abd8c
      Dan Williams 提交于
      Prepare the api for the arrival of a new parameter, 'scribble'.  This
      will allow callers to identify scratchpad memory for dma address or page
      address conversions.  As this adds yet another parameter, take this
      opportunity to convert the common submission parameters (flags,
      dependency, callback, and callback argument) into an object that is
      passed by reference.
      
      Also, take this opportunity to fix up the kerneldoc and add notes about
      the relevant ASYNC_TX_* flags for each routine.
      
      [ Impact: moves api pass-by-value parameters to a pass-by-reference struct ]
      Signed-off-by: NAndre Noll <maan@systemlinux.org>
      Acked-by: NMaciej Sosnowski <maciej.sosnowski@intel.com>
      Signed-off-by: NDan Williams <dan.j.williams@intel.com>
      a08abd8c
    • D
      async_tx: kill ASYNC_TX_DEP_ACK flag · 88ba2aa5
      Dan Williams 提交于
      In support of inter-channel chaining async_tx utilizes an ack flag to
      gate whether a dependent operation can be chained to another.  While the
      flag is not set the chain can be considered open for appending.  Setting
      the ack flag closes the chain and flags the descriptor for garbage
      collection.  The ASYNC_TX_DEP_ACK flag essentially means "close the
      chain after adding this dependency".  Since each operation can only have
      one child the api now implicitly sets the ack flag at dependency
      submission time.  This removes an unnecessary management burden from
      clients of the api.
      
      [ Impact: clean up and enforce one dependency per operation ]
      Reviewed-by: NAndre Noll <maan@systemlinux.org>
      Acked-by: NMaciej Sosnowski <maciej.sosnowski@intel.com>
      Signed-off-by: NDan Williams <dan.j.williams@intel.com>
      88ba2aa5
  4. 09 4月, 2009 2 次提交
  5. 03 4月, 2009 1 次提交
  6. 02 4月, 2009 1 次提交
  7. 31 3月, 2009 21 次提交
    • N
      md/raid5 revise rules for when to update metadata during reshape · c8f517c4
      NeilBrown 提交于
      We currently update the metadata :
       1/ every 3Megabytes
       2/ When the place we will write new-layout data to is recorded in
          the metadata as still containing old-layout data.
      
      Rule one exists to avoid having to re-do too much reshaping in the
      face of a crash/restart.  So it should really be time based rather
      than size based.  So change it to "every 10 seconds".
      
      Rule two turns out to be too harsh when restriping an array
      'in-place', as in that case the metadata much be updates for every
      stripe.
      For the in-place update, it can only possibly be safe from a crash if
      some user-space program data a backup of every e.g. few hundred
      stripes before allowing them to be reshaped.  In that case, the
      constant metadata update is pointless.
      So only update the metadata if the new metadata will report that the
      end of the 'old-layout' data is beyond where we are currently
      writing 'new-layout' data.
      Signed-off-by: NNeilBrown <neilb@suse.de>
      c8f517c4
    • N
      md/raid5: minor code cleanups in make_request. · b0f9ec04
      NeilBrown 提交于
      ... and to be certain the that make_request doesn't wait forever,
      add a 'wake_up' when ->reshape_progress has been set to MaxSector
      Signed-off-by: NNeilBrown <neilb@suse.de>
      b0f9ec04
    • N
      md: remove CONFIG_MD_RAID_RESHAPE config option. · 2cffc4a0
      NeilBrown 提交于
      This was only needed when the code was experimental.  Most of it
      is well tested now, so the option is no longer useful.
      Signed-off-by: NNeilBrown <neilb@suse.de>
      2cffc4a0
    • N
      md/raid5: be more careful about write ordering when reshaping. · ab69ae12
      NeilBrown 提交于
      When we are reshaping an array, it is very important that we read
      the data from a particular sector offset before writing new data
      at that offset.
      
      In most cases when growing or shrinking an array we read long before
      we even consider writing.  But when restriping an array without
      changing it size, there is a small possibility that we might have
      some data to available write before the read has happened at the same
      location.  This would require some stripes to be in cache already.
      
      To guard against this small possibility, we check, before writing,
      that the 'old' stripe at the same location is not in the process of
      being read.  And we ensure that we mark all 'source' stripes as such
      before allowing new 'destination' stripes to proceed.
      Signed-off-by: NNeilBrown <neilb@suse.de>
      ab69ae12
    • N
      md: don't display meaningless values in sysfs files resync_start and sync_speed · d1a7c503
      NeilBrown 提交于
      When no resync if happening, both of these files currently have
      meaningless values (is slightly different ways).
      Change them to "none" in that case.
      Signed-off-by: NNeilBrown <neilb@suse.de>
      d1a7c503
    • N
      md/raid5: allow layout and chunksize to be changed on active array. · 88ce4930
      NeilBrown 提交于
      If an array has 3 or more devices, we allow the chunksize or layout
      to be changed and when a reshape starts, we use these as the 'new'
      values.
      Signed-off-by: NNeilBrown <neilb@suse.de>
      88ce4930
    • N
      md/raid5: reshape using largest of old and new chunk size · 7a661381
      NeilBrown 提交于
      This ensures that even when old and new stripes are overlapping,
      we will try to read all of the old before having to write any
      of the new.
      Signed-off-by: NNeilBrown <neilb@suse.de>
      7a661381
    • N
      md/raid5: prepare for allowing reshape to change layout · e183eaed
      NeilBrown 提交于
      Add prev_algo to raid5_conf_t along the same lines as prev_chunk
      and previous_raid_disks.
      Signed-off-by: NNeilBrown <neilb@suse.de>
      e183eaed
    • N
      md/raid5: prepare for allowing reshape to change chunksize. · 784052ec
      NeilBrown 提交于
      Add "prev_chunk" to raid5_conf_t, similar to "previous_raid_disks", to
      remember what the chunk size was before the reshape that is currently
      underway.
      
      This seems like duplication with "chunk_size" and "new_chunk" in
      mddev_t, and to some extent it is, but there are differences.
      The values in mddev_t are always defined and often the same.
      The prev* values are only defined if a reshape is underway.
      
      Also (and more significantly) the raid5_conf_t values will be changed
      at the same time (inside an appropriate lock) that the reshape is
      started by setting reshape_position.  In contrast, the new_chunk value
      is set when the sysfs file is written which could be well before the
      reshape starts.
      Signed-off-by: NNeilBrown <neilb@suse.de>
      784052ec
    • N
      md/raid5: clearly differentiate 'before' and 'after' stripes during reshape. · 86b42c71
      NeilBrown 提交于
      During a raid5 reshape, we have some stripes in the cache that are
      'before' the reshape (and are still to be processed) and some that are
      'after'.  They are currently differentiated by having different
      ->disks values as the only reshape current supported involves changing
      the number of disks.
      
      However we will soon support reshapes that do not change the number
      of disks (chunk parity or chunk size).  So make the difference more
      explicit with a 'generation' number.
      Signed-off-by: NNeilBrown <neilb@suse.de>
      86b42c71
    • N
      Documentation/md.txt update · 11373542
      NeilBrown 提交于
      Update md.txt to reflect recent changes in a number of sysfs
      attributes.
      Signed-off-by: NNeilBrown <neilb@suse.de>
      11373542
    • N
      md: allow number of drives in raid5 to be reduced · ec32a2bd
      NeilBrown 提交于
      When reshaping a raid5 to have fewer devices, we work from the end of
      the array to the beginning.
      md_do_sync gives addresses to sync_request that go from the beginning
      to the end.  So largely ignore them use the internal state variable
      "reshape_progress" to keep track of what to do next.
      
      Never allow the size to be reduced below the minimum (4 for raid6,
      3 otherwise).
      
      We require that the size of the array has already been reduced before
      the array is reshaped to a smaller size.  This is because simply
      reducing the size is an easily reversible operation, while the reshape
      is immediately destructive and so is not reversible for the blocks at
      the ends of the devices.
      Thus to reshape an array to have fewer devices, you must first write
      an appropriately small size to md/array_size.
      
      When reshape finished, we remove any drives that are no longer
      needed and fix up ->degraded.
      Signed-off-by: NNeilBrown <neilb@suse.de>
      ec32a2bd
    • N
      md/raid5: change reshape-progress measurement to cope with reshaping backwards. · fef9c61f
      NeilBrown 提交于
      When reducing the number of devices in a raid4/5/6, the reshape
      process has to start at the end of the array and work down to the
      beginning.  So we need to handle expand_progress and expand_lo
      differently.
      
      This patch renames "expand_progress" and "expand_lo" to avoid the
      implication that anything is getting bigger (expand->reshape) and
      every place they are used, we make sure that they are used the right
      way depending on whether delta_disks is positive or negative.
      Signed-off-by: NNeilBrown <neilb@suse.de>
      fef9c61f
    • N
      md: add explicit method to signal the end of a reshape. · cea9c228
      NeilBrown 提交于
      Currently raid5 (the only module that supports restriping)
      notices that the reshape has finished be sync_request being
      given a large value, and handles any cleanup them.
      
      This patch changes it so md_check_recovery calls into an
      explicit finish_reshape method as well.
      
      The clean-up from sync_request can do things that need to be
      done promptly, typically things local to the raid5_conf_t
      structure.
      
      The "finish_reshape" method is called under the mddev_lock
      so it can do things involving reconfiguring the device.
      
      This allows us to get rid of md_set_array_sectors_locked, which
      would have caused a deadlock if you tried to stop and array
      while a reshape was happening.
      Signed-off-by: NNeilBrown <neilb@suse.de>
      cea9c228
    • N
      md/raid5: enhance raid5_size to work correctly with negative delta_disks · 7ec05478
      NeilBrown 提交于
      This is the first of four patches which combine to allow md/raid5 to
      reduce the number of devices in the array by restriping the data over
      a subset of the devices.
      
      If the number of disks in a raid4/5/6 is being reduced, then the
      default size must be based on the new number, not the old number
      of devices.
      In general, it should be based on the smaller of new and old.
      Signed-off-by: NNeilBrown <neilb@suse.de>
      7ec05478
    • N
      md/raid5: drop qd_idx from r6_state · 34e04e87
      NeilBrown 提交于
      We now have this value in stripe_head so we don't need to duplicate
      it.
      Signed-off-by: NNeilBrown <neilb@suse.de>
      34e04e87
    • D
      md/raid6: move raid6 data processing to raid6_pq.ko · f701d589
      Dan Williams 提交于
      Move the raid6 data processing routines into a standalone module
      (raid6_pq) to prepare them to be called from async_tx wrappers and other
      non-md drivers/modules.  This precludes a circular dependency of raid456
      needing the async modules for data processing while those modules in
      turn depend on raid456 for the base level synchronous raid6 routines.
      
      To support this move:
      1/ The exportable definitions in raid6.h move to include/linux/raid/pq.h
      2/ The raid6_call, recovery calls, and table symbols are exported
      3/ Extra #ifdef __KERNEL__ statements to enable the userspace raid6test to
         compile
      Signed-off-by: NDan Williams <dan.j.williams@intel.com>
      Signed-off-by: NNeilBrown <neilb@suse.de>
      f701d589
    • A
      md: raid5 run(): Fix max_degraded for raid level 4. · 18b00334
      Andre Noll 提交于
      raid4 allows only one failed disk.
      Signed-off-by: NAndre Noll <maan@systemlinux.org>
      Signed-off-by: NNeilBrown <neilb@suse.de>
      18b00334
    • D
      md: 'array_size' sysfs attribute · b522adcd
      Dan Williams 提交于
      Allow userspace to set the size of the array according to the following
      semantics:
      
      1/ size must be <= to the size returned by mddev->pers->size(mddev, 0, 0)
         a) If size is set before the array is running, do_md_run will fail
            if size is greater than the default size
         b) A reshape attempt that reduces the default size to less than the set
            array size should be blocked
      2/ once userspace sets the size the kernel will not change it
      3/ writing 'default' to this attribute returns control of the size to the
         kernel and reverts to the size reported by the personality
      
      Also, convert locations that need to know the default size from directly
      reading ->array_sectors to <pers>_size.  Resync/reshape operations
      always follow the default size.
      
      Finally, fixup other locations that read a number of 1k-blocks from
      userspace to use strict_blocks_to_sectors() which checks for unsigned
      long long to sector_t overflow and blocks to sectors overflow.
      Reviewed-by: NAndre Noll <maan@systemlinux.org>
      Signed-off-by: NDan Williams <dan.j.williams@intel.com>
      b522adcd
    • D
      md: centralize ->array_sectors modifications · 1f403624
      Dan Williams 提交于
      Get personalities out of the business of directly modifying
      ->array_sectors.  Lays groundwork to introduce policy on when
      ->array_sectors can be modified.
      Reviewed-by: NAndre Noll <maan@systemlinux.org>
      Signed-off-by: NDan Williams <dan.j.williams@intel.com>
      1f403624
    • D
      md: add 'size' as a personality method · 80c3a6ce
      Dan Williams 提交于
      In preparation for giving userspace control over ->array_sectors we need
      to be able to retrieve the 'default' size, and the 'anticipated' size
      when a reshape is requested.  For personalities that do not reshape emit
      a warning if anything but the default size is requested.
      
      In the raid5 case we need to update ->previous_raid_disks to make the
      new 'default' size available.
      Reviewed-by: NAndre Noll <maan@systemlinux.org>
      Signed-off-by: NDan Williams <dan.j.williams@intel.com>
      80c3a6ce