src/patches/suse-2.6.27.31/patches.fixes/blk-timeout-readd-timeout-list

   1 From: Hannes Reinecke <hare@suse.de>
   2 Subject: Kernel bug in kmpathd during FC cable pulls
   3 References: bnc#476330
   4
   5 Kernel bug in kmpathd during FC cable pulls.
   6 After one FC cable pull cycle system produced call trace.
   7
   8 As it turned out blk_abort_requests() will not touch
   9 any requests for which the endio processing has already
  10 started. So we need to splice those requests back onto
  11 the timeout list for endio processing to be able to
  12 continue properly.
  13
  14 Signed-off-by: Hannes Reinecke <hare@suse.de>
  15
  16 diff --git a/block/blk-timeout.c b/block/blk-timeout.c
  17 index 4cc0205..bcadbb2 100644
  18 --- a/block/blk-timeout.c
  19 +++ b/block/blk-timeout.c
  20 @@ -145,6 +145,8 @@ void blk_add_timer(struct request *req)
  21   * blk_abort_queue -- Abort all request on given queue
  22   * @queue:     pointer to queue
  23   *
  24 + * We have to use list_splice() here as blk_abort_request()
  25 + * might add requests back on the timeout list.
  26   */
  27  void blk_abort_queue(struct request_queue *q)
  28  {
  29 @@ -161,6 +163,9 @@ void blk_abort_queue(struct request_queue *q)
  30         list_for_each_entry_safe(rq, tmp, &list, timeout_list)
  31                 blk_abort_request(rq);
  32
  33 +       /* Add remaining requests back on the list */
  34 +       list_splice(&list, &q->timeout_list);
  35 +
  36         spin_unlock_irqrestore(q->queue_lock, flags);
  37
  38  }