1. 14 Apr, 2017 7 commits
    • Dan Carpenter's avatar
      net: off by one in inet6_pton() · a88086e0
      Dan Carpenter authored
      If "scope_len" is sizeof(scope_id) then we would put the NUL terminator
      one space beyond the end of the buffer.
      
      Fixes: b1a951fe ("net/utils: generic inet_pton_with_scope helper")
      Signed-off-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
      Signed-off-by: default avatarJens Axboe <axboe@fb.com>
      a88086e0
    • Omar Sandoval's avatar
      blk-mq: introduce Kyber multiqueue I/O scheduler · 00e04393
      Omar Sandoval authored
      The Kyber I/O scheduler is an I/O scheduler for fast devices designed to
      scale to multiple queues. Users configure only two knobs, the target
      read and synchronous write latencies, and the scheduler tunes itself to
      achieve that latency goal.
      
      The implementation is based on "tokens", built on top of the scalable
      bitmap library. Tokens serve as a mechanism for limiting requests. There
      are two tiers of tokens: queueing tokens and dispatch tokens.
      
      A queueing token is required to allocate a request. In fact, these
      tokens are actually the blk-mq internal scheduler tags, but the
      scheduler manages the allocation directly in order to implement its
      policy.
      
      Dispatch tokens are device-wide and split up into two scheduling
      domains: reads vs. writes. Each hardware queue dispatches batches
      round-robin between the scheduling domains as long as tokens are
      available for that domain.
      
      These tokens can be used as the mechanism to enable various policies.
      The policy Kyber uses is inspired by active queue management techniques
      for network routing, similar to blk-wbt. The scheduler monitors
      latencies and scales the number of dispatch tokens accordingly. Queueing
      tokens are used to prevent starvation of synchronous requests by
      asynchronous requests.
      
      Various extensions are possible, including better heuristics and ionice
      support. The new scheduler isn't set as the default yet.
      Signed-off-by: default avatarOmar Sandoval <osandov@fb.com>
      Signed-off-by: default avatarJens Axboe <axboe@fb.com>
      00e04393
    • Omar Sandoval's avatar
      blk-mq-sched: make completed_request() callback more useful · c05f8525
      Omar Sandoval authored
      Currently, this callback is called right after put_request() and has no
      distinguishable purpose. Instead, let's call it before put_request() as
      soon as I/O has completed on the request, before we account it in
      blk-stat. With this, Kyber can enable stats when it sees a latency
      outlier and make sure the outlier gets accounted.
      Signed-off-by: default avatarOmar Sandoval <osandov@fb.com>
      Signed-off-by: default avatarJens Axboe <axboe@fb.com>
      c05f8525
    • Omar Sandoval's avatar
      blk-mq: export helpers · 5b727272
      Omar Sandoval authored
      blk_mq_finish_request() is required for schedulers that define their own
      put_request(). blk_mq_run_hw_queue() is required for schedulers that
      hold back requests to be run later.
      Signed-off-by: default avatarOmar Sandoval <osandov@fb.com>
      Signed-off-by: default avatarJens Axboe <axboe@fb.com>
      5b727272
    • Omar Sandoval's avatar
      blk-mq: add shallow depth option for blk_mq_get_tag() · 229a9287
      Omar Sandoval authored
      Wire up the sbitmap_get_shallow() operation to the tag code so that a
      caller can limit the number of tags available to it.
      Signed-off-by: default avatarOmar Sandoval <osandov@fb.com>
      Signed-off-by: default avatarJens Axboe <axboe@fb.com>
      229a9287
    • Omar Sandoval's avatar
      sbitmap: add sbitmap_get_shallow() operation · c05e6673
      Omar Sandoval authored
      This operation supports the use case of limiting the number of bits that
      can be allocated for a given operation. Rather than setting aside some
      bits at the end of the bitmap, we can set aside bits in each word of the
      bitmap. This means we can keep the allocation hints spread out and
      support sbitmap_resize() nicely at the cost of lower granularity for the
      allowed depth.
      Signed-off-by: default avatarOmar Sandoval <osandov@fb.com>
      Signed-off-by: default avatarJens Axboe <axboe@fb.com>
      c05e6673
    • Christoph Hellwig's avatar
      remove the mg_disk driver · 84253394
      Christoph Hellwig authored
      This drivers was added in 2008, but as far as a I can tell we never had a
      single platform that actually registered resources for the platform driver.
      
      It's also been unmaintained for a long time and apparently has a ATA mode
      that can be driven using the IDE/libata subsystem.
      Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
      Reviewed-by: default avatarHannes Reinecke <hare@suse.com>
      Signed-off-by: default avatarJens Axboe <axboe@fb.com>
      84253394
  2. 11 Apr, 2017 1 commit
    • Jan Kara's avatar
      block: Fix list corruption of blk stats callback list · 3f19cd23
      Jan Kara authored
      When CFQ calls wbt_disable_default(), it will call
      blk_stat_remove_callback() to stop gathering IO statistics for the
      purposes of writeback throttling. Later, when request_queue is
      unregistered, wbt_exit() will call blk_stat_remove_callback() again
      which will try to delete callback from the list again and possibly cause
      list corruption.
      
      Fix the problem by making wbt_disable_default() called wbt_exit() which
      is properly guarded against being called multiple times.
      Signed-off-by: default avatarJan Kara <jack@suse.cz>
      Signed-off-by: default avatarJens Axboe <axboe@fb.com>
      3f19cd23
  3. 10 Apr, 2017 2 commits
  4. 08 Apr, 2017 27 commits
  5. 07 Apr, 2017 3 commits