Merge tag 'md/3.19' of git://neil.brown.name/md

Pull md updates from Neil Brown:
 "Three fixes for md.

   I did have a largish set of locking changes queued, but late testing
  showed they weren't quite as stable as I thought and while I fixed
  what I found, I decided it safer to delay them a release ...
  particularly as I'll be AFK for a few weeks.  So expect a larger batch
  next time :-)"

* tag 'md/3.19' of git://neil.brown.name/md:
  md: Check MD_RECOVERY_RUNNING as well as ->sync_thread.
  md: fix semicolon.cocci warnings
  md/raid5: fetch_block must fetch all the blocks handle_stripe_dirtying wants.

drivers/md/md.c

@@ -2691,7 +2691,8 @@ static ssize_t new_offset_store(struct md_rdev *rdev,
 	if (kstrtoull(buf, 10, &new_offset) < 0)
 		return -EINVAL;
 
-	if (mddev->sync_thread)
+	if (mddev->sync_thread ||
+	    test_bit(MD_RECOVERY_RUNNING,&mddev->recovery))
 		return -EBUSY;
 	if (new_offset == rdev->data_offset)
 		/* reset is always permitted */
@@ -3268,6 +3269,7 @@ level_store(struct mddev *mddev, const char *buf, size_t len)
 	 */
 
 	if (mddev->sync_thread ||
+	    test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
 	    mddev->reshape_position != MaxSector ||
 	    mddev->sysfs_active)
 		return -EBUSY;
@@ -4022,6 +4024,7 @@ action_store(struct mddev *mddev, const char *page, size_t len)
 		clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
 
 	if (cmd_match(page, "idle") || cmd_match(page, "frozen")) {
+		flush_workqueue(md_misc_wq);
 		if (mddev->sync_thread) {
 			set_bit(MD_RECOVERY_INTR, &mddev->recovery);
 			md_reap_sync_thread(mddev);
@@ -5040,6 +5043,7 @@ static void md_clean(struct mddev *mddev)
 static void __md_stop_writes(struct mddev *mddev)
 {
 	set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
+	flush_workqueue(md_misc_wq);
 	if (mddev->sync_thread) {
 		set_bit(MD_RECOVERY_INTR, &mddev->recovery);
 		md_reap_sync_thread(mddev);
@@ -5100,19 +5104,22 @@ static int md_set_readonly(struct mddev *mddev, struct block_device *bdev)
 		set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
 		md_wakeup_thread(mddev->thread);
 	}
-	if (mddev->sync_thread) {
+	if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
 		set_bit(MD_RECOVERY_INTR, &mddev->recovery);
+	if (mddev->sync_thread)
 		/* Thread might be blocked waiting for metadata update
 		 * which will now never happen */
 		wake_up_process(mddev->sync_thread->tsk);
-	}
+
 	mddev_unlock(mddev);
-	wait_event(resync_wait, mddev->sync_thread == NULL);
+	wait_event(resync_wait, !test_bit(MD_RECOVERY_RUNNING,
+					  &mddev->recovery));
 	mddev_lock_nointr(mddev);
 
 	mutex_lock(&mddev->open_mutex);
 	if ((mddev->pers && atomic_read(&mddev->openers) > !!bdev) ||
 	    mddev->sync_thread ||
+	    test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
 	    (bdev && !test_bit(MD_STILL_CLOSED, &mddev->flags))) {
 		printk("md: %s still in use.\n",mdname(mddev));
 		if (did_freeze) {
@@ -5158,20 +5165,24 @@ static int do_md_stop(struct mddev *mddev, int mode,
 		set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
 		md_wakeup_thread(mddev->thread);
 	}
-	if (mddev->sync_thread) {
+	if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
 		set_bit(MD_RECOVERY_INTR, &mddev->recovery);
+	if (mddev->sync_thread)
 		/* Thread might be blocked waiting for metadata update
 		 * which will now never happen */
 		wake_up_process(mddev->sync_thread->tsk);
-	}
+
 	mddev_unlock(mddev);
-	wait_event(resync_wait, mddev->sync_thread == NULL);
+	wait_event(resync_wait, (mddev->sync_thread == NULL &&
+				 !test_bit(MD_RECOVERY_RUNNING,
+					   &mddev->recovery)));
 	mddev_lock_nointr(mddev);
 
 	mutex_lock(&mddev->open_mutex);
 	if ((mddev->pers && atomic_read(&mddev->openers) > !!bdev) ||
 	    mddev->sysfs_active ||
 	    mddev->sync_thread ||
+	    test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
 	    (bdev && !test_bit(MD_STILL_CLOSED, &mddev->flags))) {
 		printk("md: %s still in use.\n",mdname(mddev));
 		mutex_unlock(&mddev->open_mutex);
@@ -5946,7 +5957,8 @@ static int update_size(struct mddev *mddev, sector_t num_sectors)
 	 * of each device.  If num_sectors is zero, we find the largest size
 	 * that fits.
 	 */
-	if (mddev->sync_thread)
+	if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
+	    mddev->sync_thread)
 		return -EBUSY;
 	if (mddev->ro)
 		return -EROFS;
@@ -5977,7 +5989,9 @@ static int update_raid_disks(struct mddev *mddev, int raid_disks)
 	if (raid_disks <= 0 ||
 	    (mddev->max_disks && raid_disks >= mddev->max_disks))
 		return -EINVAL;
-	if (mddev->sync_thread || mddev->reshape_position != MaxSector)
+	if (mddev->sync_thread ||
+	    test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
+	    mddev->reshape_position != MaxSector)
 		return -EBUSY;
 
 	rdev_for_each(rdev, mddev) {
@@ -6965,7 +6979,7 @@ static unsigned int mdstat_poll(struct file *filp, poll_table *wait)
 	int mask;
 
 	if (md_unloading)
-		return POLLIN|POLLRDNORM|POLLERR|POLLPRI;;
+		return POLLIN|POLLRDNORM|POLLERR|POLLPRI;
 	poll_wait(filp, &md_event_waiters, wait);
 
 	/* always allow read */
@@ -7589,6 +7603,7 @@ static void md_start_sync(struct work_struct *ws)
 		clear_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
 		clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
 		clear_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
+		wake_up(&resync_wait);
 		if (test_and_clear_bit(MD_RECOVERY_RECOVER,
 				       &mddev->recovery))
 			if (mddev->sysfs_action)
@@ -7757,6 +7772,7 @@ void md_check_recovery(struct mddev *mddev)
 	not_running:
 		if (!mddev->sync_thread) {
 			clear_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
+			wake_up(&resync_wait);
 			if (test_and_clear_bit(MD_RECOVERY_RECOVER,
 					       &mddev->recovery))
 				if (mddev->sysfs_action)
@@ -7775,7 +7791,6 @@ void md_reap_sync_thread(struct mddev *mddev)
 
 	/* resync has finished, collect result */
 	md_unregister_thread(&mddev->sync_thread);
-	wake_up(&resync_wait);
 	if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery) &&
 	    !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
 		/* success...*/
@@ -7803,6 +7818,7 @@ void md_reap_sync_thread(struct mddev *mddev)
 	clear_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
 	clear_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
 	clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
+	wake_up(&resync_wait);
 	/* flag recovery needed just to double check */
 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
 	sysfs_notify_dirent_safe(mddev->sysfs_action);

drivers/md/raid5.c

@@ -2917,8 +2917,11 @@ static int fetch_block(struct stripe_head *sh, struct stripe_head_state *s,
 	     (sh->raid_conf->level <= 5 && s->failed && fdev[0]->towrite &&
 	      (!test_bit(R5_Insync, &dev->flags) || test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) &&
 	      !test_bit(R5_OVERWRITE, &fdev[0]->flags)) ||
-	     (sh->raid_conf->level == 6 && s->failed && s->to_write &&
-	      s->to_write - s->non_overwrite < sh->raid_conf->raid_disks - 2 &&
+	     ((sh->raid_conf->level == 6 ||
+	       sh->sector >= sh->raid_conf->mddev->recovery_cp)
+	      && s->failed && s->to_write &&
+	      (s->to_write - s->non_overwrite <
+	       sh->raid_conf->raid_disks - sh->raid_conf->max_degraded) &&
 	      (!test_bit(R5_Insync, &dev->flags) || test_bit(STRIPE_PREREAD_ACTIVE, &sh->state))))) {
 		/* we would like to get this block, possibly by computing it,
 		 * otherwise read it if the backing disk is insync