Merge tag 'md/3.14' of git://neil.brown.name/md

Pull md updates from Neil Brown:
"All bug fixes, two tagged for -stable"

* tag 'md/3.14' of git://neil.brown.name/md:
md/raid5: close recently introduced race in stripe_head management.
md/raid5: fix long-standing problem with bitmap handling on write failure.
md: check command validity early in md_ioctl().
md: ensure metadata is writen after raid level change.
md/raid10: avoid fullsync when not necessary.
md: allow a partially recovered device to be hot-added to an array.
md: Change handling of save_raid_disk and metadata update during recovery.

drivers/md/md.c

···
 			    desc->raid_disk < mddev->raid_disks */) {
 			set_bit(In_sync, &rdev->flags);
 			rdev->raid_disk = desc->raid_disk;
+			rdev->saved_raid_disk = desc->raid_disk;
 		} else if (desc->state & (1<<MD_DISK_ACTIVE)) {
 			/* active but not in sync implies recovery up to
 			 * reshape position.  We don't know exactly where
···
 			set_bit(Faulty, &rdev->flags);
 			break;
 		default:
+			rdev->saved_raid_disk = role;
 			if ((le32_to_cpu(sb->feature_map) &
-			     MD_FEATURE_RECOVERY_OFFSET))
+			     MD_FEATURE_RECOVERY_OFFSET)) {
 				rdev->recovery_offset = le64_to_cpu(sb->recovery_offset);
-			else
+				if (!(le32_to_cpu(sb->feature_map) &
+				      MD_FEATURE_RECOVERY_BITMAP))
+					rdev->saved_raid_disk = -1;
+			} else
 				set_bit(In_sync, &rdev->flags);
 			rdev->raid_disk = role;
 			break;
···
 			cpu_to_le32(MD_FEATURE_RECOVERY_OFFSET);
 		sb->recovery_offset =
 			cpu_to_le64(rdev->recovery_offset);
+		if (rdev->saved_raid_disk >= 0 && mddev->bitmap)
+			sb->feature_map |=
+				cpu_to_le32(MD_FEATURE_RECOVERY_BITMAP);
 	}
 	if (test_bit(Replacement, &rdev->flags))
 		sb->feature_map |=
···
 		if (rdev->sb_loaded != 1)
 			continue; /* no noise on spare devices */
 
-		if (!test_bit(Faulty, &rdev->flags) &&
-		    rdev->saved_raid_disk == -1) {
+		if (!test_bit(Faulty, &rdev->flags)) {
 			md_super_write(mddev,rdev,
 				       rdev->sb_start, rdev->sb_size,
 				       rdev->sb_page);
···
 				rdev->badblocks.size = 0;
 			}
 
-		} else if (test_bit(Faulty, &rdev->flags))
+		} else
 			pr_debug("md: %s (skipping faulty)\n",
 				 bdevname(rdev->bdev, b));
-		else
-			pr_debug("(skipping incremental s/r ");
 
 		if (mddev->level == LEVEL_MULTIPATH)
 			/* only need to write one superblock... */
···
 	 *  blocked - sets the Blocked flags
 	 *  -blocked - clears the Blocked and possibly simulates an error
 	 *  insync - sets Insync providing device isn't active
+	 *  -insync - clear Insync for a device with a slot assigned,
+	 *            so that it gets rebuilt based on bitmap
 	 *  write_error - sets WriteErrorSeen
 	 *  -write_error - clears WriteErrorSeen
 	 */
···
 		err = 0;
 	} else if (cmd_match(buf, "insync") && rdev->raid_disk == -1) {
 		set_bit(In_sync, &rdev->flags);
+		err = 0;
+	} else if (cmd_match(buf, "-insync") && rdev->raid_disk >= 0) {
+		clear_bit(In_sync, &rdev->flags);
+		rdev->saved_raid_disk = rdev->raid_disk;
+		rdev->raid_disk = -1;
 		err = 0;
 	} else if (cmd_match(buf, "write_error")) {
 		set_bit(WriteErrorSeen, &rdev->flags);
···
 	pers->run(mddev);
 	set_bit(MD_CHANGE_DEVS, &mddev->flags);
 	mddev_resume(mddev);
+	if (!mddev->thread)
+		md_update_sb(mddev, 1);
 	sysfs_notify(&mddev->kobj, NULL, "level");
 	md_new_event(mddev);
 	return rv;
···
 				clear_bit(Bitmap_sync, &rdev->flags);
 			} else
 				rdev->raid_disk = -1;
+			rdev->saved_raid_disk = rdev->raid_disk;
 		} else
 			super_types[mddev->major_version].
 				validate_super(mddev, rdev);
···
 			export_rdev(rdev);
 			return -EINVAL;
 		}
-
-		if (test_bit(In_sync, &rdev->flags))
-			rdev->saved_raid_disk = rdev->raid_disk;
-		else
-			rdev->saved_raid_disk = -1;
 
 		clear_bit(In_sync, &rdev->flags); /* just to be sure */
 		if (info->state & (1<<MD_DISK_WRITEMOSTLY))
···
 	return 0;
 }
 
+static inline bool md_ioctl_valid(unsigned int cmd)
+{
+	switch (cmd) {
+	case ADD_NEW_DISK:
+	case BLKROSET:
+	case GET_ARRAY_INFO:
+	case GET_BITMAP_FILE:
+	case GET_DISK_INFO:
+	case HOT_ADD_DISK:
+	case HOT_REMOVE_DISK:
+	case PRINT_RAID_DEBUG:
+	case RAID_AUTORUN:
+	case RAID_VERSION:
+	case RESTART_ARRAY_RW:
+	case RUN_ARRAY:
+	case SET_ARRAY_INFO:
+	case SET_BITMAP_FILE:
+	case SET_DISK_FAULTY:
+	case STOP_ARRAY:
+	case STOP_ARRAY_RO:
+		return true;
+	default:
+		return false;
+	}
+}
+
 static int md_ioctl(struct block_device *bdev, fmode_t mode,
 			unsigned int cmd, unsigned long arg)
 {
···
 	void __user *argp = (void __user *)arg;
 	struct mddev *mddev = NULL;
 	int ro;
+
+	if (!md_ioctl_valid(cmd))
+		return -ENOTTY;
 
 	switch (cmd) {
 	case RAID_VERSION:
···
 		       !test_bit(Bitmap_sync, &rdev->flags)))
 			continue;
 
-		rdev->recovery_offset = 0;
+		if (rdev->saved_raid_disk < 0)
+			rdev->recovery_offset = 0;
 		if (mddev->pers->
 		    hot_add_disk(mddev, rdev) == 0) {
 			if (sysfs_link_rdev(mddev, rdev))
···
 		mddev->pers->finish_reshape(mddev);
 
 	/* If array is no-longer degraded, then any saved_raid_disk
-	 * information must be scrapped.  Also if any device is now
-	 * In_sync we must scrape the saved_raid_disk for that device
-	 * do the superblock for an incrementally recovered device
-	 * written out.
+	 * information must be scrapped.
 	 */
-	rdev_for_each(rdev, mddev)
-		if (!mddev->degraded ||
-		    test_bit(In_sync, &rdev->flags))
+	if (!mddev->degraded)
+		rdev_for_each(rdev, mddev)
 			rdev->saved_raid_disk = -1;
 
 	md_update_sb(mddev, 1);

drivers/md/raid10.c

···
 		    !test_bit(In_sync, &disk->rdev->flags)) {
 			disk->head_position = 0;
 			mddev->degraded++;
-			if (disk->rdev)
+			if (disk->rdev &&
+			    disk->rdev->saved_raid_disk < 0)
 				conf->fullsync = 1;
 		}
 		disk->recovery_disabled = mddev->recovery_disabled - 1;

drivers/md/raid5.c

···
 					 || !conf->inactive_blocked),
 					*(conf->hash_locks + hash));
 				conf->inactive_blocked = 0;
-			} else
+			} else {
 				init_stripe(sh, sector, previous);
+				atomic_inc(&sh->count);
+			}
 		} else {
 			spin_lock(&conf->device_lock);
 			if (atomic_read(&sh->count)) {
···
 					sh->group = NULL;
 				}
 			}
+			atomic_inc(&sh->count);
 			spin_unlock(&conf->device_lock);
 		}
 	} while (sh == NULL);
-
-	if (sh)
-		atomic_inc(&sh->count);
 
 	spin_unlock_irq(conf->hash_locks + hash);
 	return sh;
···
 			set_bit(R5_MadeGoodRepl, &sh->dev[i].flags);
 	} else {
 		if (!uptodate) {
+			set_bit(STRIPE_DEGRADED, &sh->state);
 			set_bit(WriteErrorSeen, &rdev->flags);
 			set_bit(R5_WriteError, &sh->dev[i].flags);
 			if (!test_and_set_bit(WantReplacement, &rdev->flags))

include/uapi/linux/raid/md_p.h

···
 					    * backwards anyway.
 					    */
 #define	MD_FEATURE_NEW_OFFSET		64 /* new_offset must be honoured */
+#define	MD_FEATURE_RECOVERY_BITMAP	128 /* recovery that is happening
+					     * is guided by bitmap.
+					     */
 #define	MD_FEATURE_ALL			(MD_FEATURE_BITMAP_OFFSET	\
 					|MD_FEATURE_RECOVERY_OFFSET	\
 					|MD_FEATURE_RESHAPE_ACTIVE	\
···
 					|MD_FEATURE_REPLACEMENT		\
 					|MD_FEATURE_RESHAPE_BACKWARDS	\
 					|MD_FEATURE_NEW_OFFSET		\
+					|MD_FEATURE_RECOVERY_BITMAP	\
 					)
 
-#endif 
+#endif