powerpc/prom_init: Make of_workarounds static

[sfrench/cifs-2.6.git] / block / blk-sysfs.c

diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index bb109bb0a055378fb412269d9795b50b629946a4..3772671cf2bc5ad6322786b9531e9eb8bb6c7edd 100644 (file)
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -453,9 +453,26 @@ static ssize_t queue_wb_lat_store(struct request_queue *q, const char *page,
        else if (val >= 0)
                val *= 1000ULL;
 
-       wbt_set_min_lat(q, val);
+       /*
+        * Ensure that the queue is idled, in case the latency update
+        * ends up either enabling or disabling wbt completely. We can't
+        * have IO inflight if that happens.
+        */
+       if (q->mq_ops) {
+               blk_mq_freeze_queue(q);
+               blk_mq_quiesce_queue(q);
+       } else
+               blk_queue_bypass_start(q);
 
+       wbt_set_min_lat(q, val);
        wbt_update_limits(q);
+
+       if (q->mq_ops) {
+               blk_mq_unquiesce_queue(q);
+               blk_mq_unfreeze_queue(q);
+       } else
+               blk_queue_bypass_end(q);
+
        return count;
 }