System hang during repeated alua access state changes

Issue

• System hang during repeated alua access state changes

  sd 16:0:0:70: alua: port group 01 state N non-preferred supports TolUsNA
  sd 18:0:0:74: Asymmetric access state changed
  sd 16:0:0:74: Asymmetric access state changed
  sd 17:0:0:74: Asymmetric access state changed
  sd 16:0:0:74: alua: port group 01 state N non-preferred supports TolUsNA
  sd 15:0:0:70: alua: port group 00 state A non-preferred supports TolUsNA
  sd 15:0:0:70: alua: port group 00 state A non-preferred supports TolUsNA
  sd 15:0:0:21: Asymmetric access state changed
  sd 15:0:0:21: alua: port group 00 state A non-preferred supports TolUsNA
  sd 15:0:0:76: Asymmetric access state changed
  sd 15:0:0:76: alua: port group 00 state A non-preferred supports TolUsNA
  sd 15:0:0:80: Asymmetric access state changed
  sd 15:0:0:80: alua: port group 00 state A non-preferred supports TolUsNA
  sd 16:0:0:24: Asymmetric access state changed
  sd 16:0:0:24: alua: port group 01 state A non-preferred supports TolUsNA
  ....
  INFO: task oracle:86205 blocked for more than 120 seconds.
  "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  oracle          D ffff8dbd7e4dacc0     0 86205      1 0x00000080
  Call Trace:
  [<ffffffffb1d87169>] schedule+0x29/0x70
  [<ffffffffb1d84c51>] schedule_timeout+0x221/0x2d0
  [<ffffffffb195359a>] ? queue_unplugged+0x2a/0xa0
  [<ffffffffb1706362>] ? ktime_get_ts64+0x52/0xf0
  [<ffffffffb1d8683d>] io_schedule_timeout+0xad/0x130
  [<ffffffffb16c6896>] ? prepare_to_wait_exclusive+0x56/0x90
  [<ffffffffb1d868d8>] io_schedule+0x18/0x20
  [<ffffffffb19541f3>] get_request+0x243/0x7d0
  [<ffffffffb195d001>] ? blk_rq_merge_ok+0x31/0x180
  [<ffffffffb16c6d10>] ? wake_up_atomic_t+0x30/0x30
  [<ffffffffb1956f2e>] blk_queue_bio+0xfe/0x400
  [<ffffffffb1955167>] generic_make_request+0x147/0x380
  [<ffffffffb188c149>] ? bvec_alloc+0x59/0x120
  [<ffffffffb1955410>] submit_bio+0x70/0x150
  [<ffffffffb188c423>] ? bio_alloc_bioset+0x213/0x310
  [<ffffffffb1893208>] do_blockdev_direct_IO+0x1e98/0x20b0
  [<ffffffffb188db80>] ? set_init_blocksize+0x90/0x90
  [<ffffffffb1893475>] __blockdev_direct_IO+0x55/0x60
  [<ffffffffb188db80>] ? set_init_blocksize+0x90/0x90
  [<ffffffffb188e297>] blkdev_direct_IO+0x57/0x60
  [<ffffffffb188db80>] ? set_init_blocksize+0x90/0x90
  [<ffffffffb17c0183>] generic_file_direct_write+0xd3/0x190
  [<ffffffffb17c0477>] __generic_file_aio_write+0x237/0x400
  [<ffffffffb188ec26>] blkdev_aio_write+0x56/0xb0
  [<ffffffffb188ebd0>] ? bd_acquire+0xe0/0xe0
  [<ffffffffb18a5963>] do_io_submit+0x3e3/0x8a0
  [<ffffffffb18a5e30>] SyS_io_submit+0x10/0x20
  [<ffffffffb1d93f92>] system_call_fastpath+0x25/0x2a