md: use new plugging interface for RAID IO.

md/raid submits a lot of IO from the various raid threads.
So adding start/finish plug calls to those so that some
plugging happens.

Signed-off-by: NeilBrown <neilb@suse.de>

3 files changed, 10 insertions, 1 deletions

diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index c2a21ae56d9..5449cd5e314 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -1516,9 +1516,11 @@ static void raid1d(mddev_t *mddev)
         conf_t *conf = mddev->private;
         struct list_head *head = &conf->retry_list;
         mdk_rdev_t *rdev;
+        struct blk_plug plug;
 
         md_check_recovery(mddev);
-        
+
+        blk_start_plug(&plug);
         for (;;) {
                 char b[BDEVNAME_SIZE];
 
@@ -1593,6 +1595,7 @@ static void raid1d(mddev_t *mddev)
                 }
                 cond_resched();
         }
+        blk_finish_plug(&plug);
 }
 
 
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 2da83d56659..c8e5dac5d69 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -1640,9 +1640,11 @@ static void raid10d(mddev_t *mddev)
         conf_t *conf = mddev->private;
         struct list_head *head = &conf->retry_list;
         mdk_rdev_t *rdev;
+        struct blk_plug plug;
 
         md_check_recovery(mddev);
 
+        blk_start_plug(&plug);
         for (;;) {
                 char b[BDEVNAME_SIZE];
 
@@ -1716,6 +1718,7 @@ static void raid10d(mddev_t *mddev)
                 }
                 cond_resched();
         }
+        blk_finish_plug(&plug);
 }
 
 
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index e867ee42b15..ce6960b1c68 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -4478,11 +4478,13 @@ static void raid5d(mddev_t *mddev)
         struct stripe_head *sh;
         raid5_conf_t *conf = mddev->private;
         int handled;
+        struct blk_plug plug;
 
         pr_debug("+++ raid5d active\n");
 
         md_check_recovery(mddev);
 
+        blk_start_plug(&plug);
         handled = 0;
         spin_lock_irq(&conf->device_lock);
         while (1) {
@@ -4525,6 +4527,7 @@ static void raid5d(mddev_t *mddev)
         spin_unlock_irq(&conf->device_lock);
 
         async_tx_issue_pending_all();
+        blk_finish_plug(&plug);
 
         pr_debug("--- raid5d inactive\n");
 }