1. 07 Aug, 2018 1 commit
    • Hou Tao's avatar
      dm thin: stop no_space_timeout worker when switching to write-mode · 75294442
      Hou Tao authored
      Now both check_for_space() and do_no_space_timeout() will read & write
      pool->pf.error_if_no_space.  If these functions run concurrently, as
      shown in the following case, the default setting of "queue_if_no_space"
      can get lost.
      
      precondition:
          * error_if_no_space = false (aka "queue_if_no_space")
          * pool is in Out-of-Data-Space (OODS) mode
          * no_space_timeout worker has been queued
      
      CPU 0:                          CPU 1:
      // delete a thin device
      process_delete_mesg()
      // check_for_space() invoked by commit()
      set_pool_mode(pool, PM_WRITE)
          pool->pf.error_if_no_space = \
           pt->requested_pf.error_if_no_space
      
      				// timeout, pool is still in OODS mode
      				do_no_space_timeout
      				    // "queue_if_no_space" config is lost
      				    pool->pf.error_if_no_space = true
          pool->pf.mode = new_mode
      
      Fix it by stopping no_space_timeout worker when switching to write mode.
      
      Fixes: bcc696fa
      
       ("dm thin: stay in out-of-data-space mode once no_space_timeout expires")
      Cc: stable@vger.kernel.org
      Signed-off-by: default avatarHou Tao <houtao1@huawei.com>
      Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
      75294442
  2. 31 Jul, 2018 1 commit
  3. 30 Jul, 2018 1 commit
    • Andy Grover's avatar
      dm thin: include metadata_low_watermark threshold in pool status · 63c8ecb6
      Andy Grover authored
      
      
      The metadata low watermark threshold is set by the kernel.  But the
      kernel depends on userspace to extend the thinpool metadata device when
      the threshold is crossed.
      
      Since the metadata low watermark threshold is not visible to userspace,
      upon receiving an event, userspace cannot tell that the kernel wants the
      metadata device extended, instead of some other eventing condition.
      Making it visible (but not settable) enables userspace to affirmatively
      know the kernel is asking for a metadata device extension, by comparing
      metadata_low_watermark against nr_free_blocks_metadata, also reported in
      status.
      
      Current solutions like dmeventd have their own thresholds for extending
      the data and metadata devices, and both devices are checked against
      their thresholds on each event.  This lessens the value of the kernel-set
      threshold, since userspace will either extend the metadata device sooner,
      when receiving another event; or will receive the metadata lowater event
      and do nothing, if dmeventd's threshold is less than the kernel's.
      (This second case is dangerous. The metadata lowater event will not be
      re-sent, so no further event will be generated before the metadata
      device is out if space, unless some other event causes userspace to
      recheck its thresholds.)
      Signed-off-by: default avatarAndy Grover <agrover@redhat.com>
      Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
      63c8ecb6
  4. 27 Jul, 2018 16 commits
  5. 22 Jul, 2018 8 commits
  6. 21 Jul, 2018 12 commits
  7. 20 Jul, 2018 1 commit