src/patches/suse-2.6.27.31/patches.drivers/block-call-sync-on-cleanup

   1 Subject: block: blk_cleanup_queue() should call blk_sync_queue()
   2 From: Jens Axboe <jens.axboe@oracle.com>
   3 Date: Thu Oct 9 08:56:18 2008 +0200:
   4 Git: e3335de94067dbebe22e3962632ead34e832cb60
   5
   6 When a driver calls blk_cleanup_queue(), the device should be fully idle.
   7 However, the block layer may have pending plugging timers and the IO
   8 schedulers may have pending work in the work queues. So quisce the device
   9 by waiting for the timer and flushing the work queues.
  10
  11 Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
  12 Signed-off-by: Hannes Reinecke <hare@suse.de>
  13
  14 ---
  15  block/blk-core.c |    8 ++++++++
  16  1 file changed, 8 insertions(+)
  17
  18 --- a/block/blk-core.c
  19 +++ b/block/blk-core.c
  20 @@ -435,6 +435,14 @@ void blk_put_queue(struct request_queue
  21
  22  void blk_cleanup_queue(struct request_queue *q)
  23  {
  24 +       /*
  25 +        * We know we have process context here, so we can be a little
  26 +        * cautious and ensure that pending block actions on this device
  27 +        * are done before moving on. Going into this function, we should
  28 +        * not have processes doing IO to this device.
  29 +        */
  30 +       blk_sync_queue(q);
  31 +
  32         mutex_lock(&q->sysfs_lock);
  33         queue_flag_set_unlocked(QUEUE_FLAG_DEAD, q);
  34         mutex_unlock(&q->sysfs_lock);