Merge branches 'acpi-general' and 'acpi-video'

[mirror_ubuntu-zesty-kernel.git] / block / blk-timeout.c

diff --git a/block/blk-timeout.c b/block/blk-timeout.c
index d96f7061c6fd8727de9eb9fc02fae7b07dd357c1..95a09590ccfda8366f92efbee7c31f1654c11637 100644 (file)
--- a/block/blk-timeout.c
+++ b/block/blk-timeout.c
@@ -96,11 +96,7 @@ static void blk_rq_timed_out(struct request *req)
                        __blk_complete_request(req);
                break;
        case BLK_EH_RESET_TIMER:
-               if (q->mq_ops)
-                       blk_mq_add_timer(req);
-               else
-                       blk_add_timer(req);
-
+               blk_add_timer(req);
                blk_clear_rq_complete(req);
                break;
        case BLK_EH_NOT_HANDLED:
@@ -170,7 +166,26 @@ void blk_abort_request(struct request *req)
 }
 EXPORT_SYMBOL_GPL(blk_abort_request);
 
-void __blk_add_timer(struct request *req, struct list_head *timeout_list)
+unsigned long blk_rq_timeout(unsigned long timeout)
+{
+       unsigned long maxt;
+
+       maxt = round_jiffies_up(jiffies + BLK_MAX_TIMEOUT);
+       if (time_after(timeout, maxt))
+               timeout = maxt;
+
+       return timeout;
+}
+
+/**
+ * blk_add_timer - Start timeout timer for a single request
+ * @req:       request that is about to start running.
+ *
+ * Notes:
+ *    Each request has its own timer, and as it is added to the queue, we
+ *    set up the timer. When the request completes, we cancel the timer.
+ */
+void blk_add_timer(struct request *req)
 {
        struct request_queue *q = req->q;
        unsigned long expiry;
@@ -188,32 +203,29 @@ void __blk_add_timer(struct request *req, struct list_head *timeout_list)
                req->timeout = q->rq_timeout;
 
        req->deadline = jiffies + req->timeout;
-       if (timeout_list)
-               list_add_tail(&req->timeout_list, timeout_list);
+       if (!q->mq_ops)
+               list_add_tail(&req->timeout_list, &req->q->timeout_list);
 
        /*
         * If the timer isn't already pending or this timeout is earlier
         * than an existing one, modify the timer. Round up to next nearest
         * second.
         */
-       expiry = round_jiffies_up(req->deadline);
+       expiry = blk_rq_timeout(round_jiffies_up(req->deadline));
 
        if (!timer_pending(&q->timeout) ||
-           time_before(expiry, q->timeout.expires))
-               mod_timer(&q->timeout, expiry);
+           time_before(expiry, q->timeout.expires)) {
+               unsigned long diff = q->timeout.expires - expiry;
 
-}
+               /*
+                * Due to added timer slack to group timers, the timer
+                * will often be a little in front of what we asked for.
+                * So apply some tolerance here too, otherwise we keep
+                * modifying the timer because expires for value X
+                * will be X + something.
+                */
+               if (!timer_pending(&q->timeout) || (diff >= HZ / 2))
+                       mod_timer(&q->timeout, expiry);
+       }
 
-/**
- * blk_add_timer - Start timeout timer for a single request
- * @req:       request that is about to start running.
- *
- * Notes:
- *    Each request has its own timer, and as it is added to the queue, we
- *    set up the timer. When the request completes, we cancel the timer.
- */
-void blk_add_timer(struct request *req)
-{
-       __blk_add_timer(req, &req->q->timeout_list);
 }
-