Merge tag 'md-3.10-fixes' of git://neil.brown.name/md

Pull md bugfixes from Neil Brown:
 "A few bugfixes for md

  Some tagged for -stable"

* tag 'md-3.10-fixes' of git://neil.brown.name/md:
  md/raid1,5,10: Disable WRITE SAME until a recovery strategy is in place
  md/raid1,raid10: use freeze_array in place of raise_barrier in various places.
  md/raid1: consider WRITE as successful only if at least one non-Faulty and non-rebuilding drive completed it.
  md: md_stop_writes() should always freeze recovery.

1 files changed, 19 insertions, 10 deletions

diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 59d4daa5f4c7..6ddae2501b9a 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -490,7 +490,17 @@ static void raid10_end_write_request(struct bio *bio, int error)
 		sector_t first_bad;
 		int bad_sectors;
 
-		set_bit(R10BIO_Uptodate, &r10_bio->state);
+		/*
+		 * Do not set R10BIO_Uptodate if the current device is
+		 * rebuilding or Faulty. This is because we cannot use
+		 * such device for properly reading the data back (we could
+		 * potentially use it, if the current write would have felt
+		 * before rdev->recovery_offset, but for simplicity we don't
+		 * check this here.
+		 */
+		if (test_bit(In_sync, &rdev->flags) &&
+		    !test_bit(Faulty, &rdev->flags))
+			set_bit(R10BIO_Uptodate, &r10_bio->state);
 
 		/* Maybe we can clear some bad blocks. */
 		if (is_badblock(rdev,
@@ -1055,17 +1065,17 @@ static void allow_barrier(struct r10conf *conf)
 	wake_up(&conf->wait_barrier);
 }
 
-static void freeze_array(struct r10conf *conf)
+static void freeze_array(struct r10conf *conf, int extra)
 {
 	/* stop syncio and normal IO and wait for everything to
 	 * go quiet.
 	 * We increment barrier and nr_waiting, and then
-	 * wait until nr_pending match nr_queued+1
+	 * wait until nr_pending match nr_queued+extra
 	 * This is called in the context of one normal IO request
 	 * that has failed. Thus any sync request that might be pending
 	 * will be blocked by nr_pending, and we need to wait for
 	 * pending IO requests to complete or be queued for re-try.
-	 * Thus the number queued (nr_queued) plus this request (1)
+	 * Thus the number queued (nr_queued) plus this request (extra)
 	 * must match the number of pending IOs (nr_pending) before
 	 * we continue.
 	 */
@@ -1073,7 +1083,7 @@ static void freeze_array(struct r10conf *conf)
 	conf->barrier++;
 	conf->nr_waiting++;
 	wait_event_lock_irq_cmd(conf->wait_barrier,
-				conf->nr_pending == conf->nr_queued+1,
+				conf->nr_pending == conf->nr_queued+extra,
 				conf->resync_lock,
 				flush_pending_writes(conf));
 
@@ -1837,8 +1847,8 @@ static int raid10_add_disk(struct mddev *mddev, struct md_rdev *rdev)
 		 * we wait for all outstanding requests to complete.
 		 */
 		synchronize_sched();
-		raise_barrier(conf, 0);
-		lower_barrier(conf);
+		freeze_array(conf, 0);
+		unfreeze_array(conf);
 		clear_bit(Unmerged, &rdev->flags);
 	}
 	md_integrity_add_rdev(rdev, mddev);
@@ -2612,7 +2622,7 @@ static void handle_read_error(struct mddev *mddev, struct r10bio *r10_bio)
 	r10_bio->devs[slot].bio = NULL;
 
 	if (mddev->ro == 0) {
-		freeze_array(conf);
+		freeze_array(conf, 1);
 		fix_read_error(conf, mddev, r10_bio);
 		unfreeze_array(conf);
 	} else
@@ -3609,8 +3619,7 @@ static int run(struct mddev *mddev)
 	if (mddev->queue) {
 		blk_queue_max_discard_sectors(mddev->queue,
 					      mddev->chunk_sectors);
-		blk_queue_max_write_same_sectors(mddev->queue,
-						 mddev->chunk_sectors);
+		blk_queue_max_write_same_sectors(mddev->queue, 0);
 		blk_queue_io_min(mddev->queue, chunk_size);
 		if (conf->geo.raid_disks % conf->geo.near_copies)
 			blk_queue_io_opt(mddev->queue, chunk_size * conf->geo.raid_disks);