356  * Update disk head position estimator based on IRQ completion info.
358 static inline void update_head_pos(int disk, struct r1bio *r1_bio)  in update_head_pos()  argument
362 	conf->mirrors[disk].head_position =  in update_head_pos()
367  * Find the disk number which triggered given bio
601 static void update_read_sectors(struct r1conf *conf, int disk,  in update_read_sectors()  argument
604 	struct raid1_info *info = &conf->mirrors[disk];  in update_read_sectors()
617 	int disk;  in choose_first_rdev()  local
619 	for (disk = 0 ; disk < conf->raid_disks * 2 ; disk++) {  in choose_first_rdev()
623 		if (r1_bio->bios[disk] == IO_BLOCKED)  in choose_first_rdev()
626 		rdev = conf->mirrors[disk].rdev;  in choose_first_rdev()
630 		/* choose the first disk even if it has some bad blocks. */  in choose_first_rdev()
633 			update_read_sectors(conf, disk, this_sector, read_len);  in choose_first_rdev()
635 			return disk;  in choose_first_rdev()
654 	int disk;  in choose_bb_rdev()  local
656 	for (disk = 0 ; disk < conf->raid_disks * 2 ; disk++) {  in choose_bb_rdev()
661 		if (r1_bio->bios[disk] == IO_BLOCKED)  in choose_bb_rdev()
664 		rdev = conf->mirrors[disk].rdev;  in choose_bb_rdev()
670 		/* keep track of the disk with the most readable sectors. */  in choose_bb_rdev()
674 			best_disk = disk;  in choose_bb_rdev()
693 	int disk;  in choose_slow_rdev()  local
695 	for (disk = 0 ; disk < conf->raid_disks * 2 ; disk++) {  in choose_slow_rdev()
700 		if (r1_bio->bios[disk] == IO_BLOCKED)  in choose_slow_rdev()
703 		rdev = conf->mirrors[disk].rdev;  in choose_slow_rdev()
709 		/* there are no bad blocks, we can use this disk */  in choose_slow_rdev()
714 			update_read_sectors(conf, disk, this_sector, read_len);  in choose_slow_rdev()
715 			return disk;  in choose_slow_rdev()
723 			bb_disk = disk;  in choose_slow_rdev()
736 static bool is_sequential(struct r1conf *conf, int disk, struct r1bio *r1_bio)  in is_sequential()  argument
739 	return conf->mirrors[disk].next_seq_sect == r1_bio->sector ||  in is_sequential()
740 	       conf->mirrors[disk].head_position == r1_bio->sector;  in is_sequential()
745  * disk. If yes, choose the idle disk.
747 static bool should_choose_next(struct r1conf *conf, int disk)  in should_choose_next()  argument
749 	struct raid1_info *mirror = &conf->mirrors[disk];  in should_choose_next()
769 	/* don't read from slow disk unless have to */  in rdev_readable()
791 	int disk;  in choose_best_rdev()  local
800 	for (disk = 0 ; disk < conf->raid_disks * 2 ; disk++) {  in choose_best_rdev()
805 		if (r1_bio->bios[disk] == IO_BLOCKED)  in choose_best_rdev()
808 		rdev = conf->mirrors[disk].rdev;  in choose_best_rdev()
817 		dist = abs(r1_bio->sector - conf->mirrors[disk].head_position);  in choose_best_rdev()
819 		/* Don't change to another disk for sequential reads */  in choose_best_rdev()
820 		if (is_sequential(conf, disk, r1_bio)) {  in choose_best_rdev()
821 			if (!should_choose_next(conf, disk))  in choose_best_rdev()
822 				return disk;  in choose_best_rdev()
825 			 * Add 'pending' to avoid choosing this disk if  in choose_best_rdev()
826 			 * there is other idle disk.  in choose_best_rdev()
830 			 * If there is no other idle disk, this disk  in choose_best_rdev()
833 			ctl.sequential_disk = disk;  in choose_best_rdev()
838 			ctl.min_pending_disk = disk;  in choose_best_rdev()
843 			ctl.closest_dist_disk = disk;  in choose_best_rdev()
849 	 * idle disk, so choose the sequential disk.  in choose_best_rdev()
855 	 * If all disks are rotational, choose the closest disk. If any disk is  in choose_best_rdev()
856 	 * non-rotational, choose the disk with less pending request even the  in choose_best_rdev()
857 	 * disk is rotational, which might/might not be optimal for raids with  in choose_best_rdev()
868  * This routine returns the disk from which the requested read should be done.
870  * 1) If resync is in progress, find the first usable disk and use it even if it
874  * disks and disks with bad blocks for now. Only pay attention to key disk
880  * 4) If we are all the way at the end, we have no choice but to use a disk even
888 	int disk;  in read_balance()  local
896 	disk = choose_best_rdev(conf, r1_bio);  in read_balance()
897 	if (disk >= 0) {  in read_balance()
899 		update_read_sectors(conf, disk, r1_bio->sector,  in read_balance()
901 		return disk;  in read_balance()
905 	 * If we are here it means we didn't find a perfectly good disk so  in read_balance()
909 	disk = choose_bb_rdev(conf, r1_bio, max_sectors);  in read_balance()
910 	if (disk >= 0)  in read_balance()
911 		return disk;  in read_balance()
924 	/* flush any pending bitmap writes to disk before proceeding w/ I/O */  in flush_bio_list()
1203 	 * 1) management command handlers (reshape, remove disk, quiesce).  in freeze_array()
1793 	pr_crit("md/raid1:%s: Disk failure on %pg, disabling device.\n"  in raid1_error()
1815 			pr_debug(" disk %d, wo:%d, o:%d, dev:%pg\n",  in print_conf()
1886 static bool raid1_add_conf(struct r1conf *conf, struct md_rdev *rdev, int disk,  in raid1_add_conf()  argument
1889 	struct raid1_info *info = conf->mirrors + disk;  in raid1_add_conf()
1902 	rdev->raid_disk = disk;  in raid1_add_conf()
1910 static bool raid1_remove_conf(struct r1conf *conf, int disk)  in raid1_remove_conf()  argument
1912 	struct raid1_info *info = conf->mirrors + disk;  in raid1_remove_conf()
1944 	 * find the disk ... but prefer rdev->saved_raid_disk  in raid1_add_disk()
2553 			 * Badblocks set failed, disk marked Faulty.  in narrow_write_error()
2786 	int disk = -1;  in raid1_sync_request()  local
2912 					if (disk < 0)  in raid1_sync_request()
2913 						disk = i;  in raid1_sync_request()
2940 	if (disk < 0)  in raid1_sync_request()
2941 		disk = wonly;  in raid1_sync_request()
2942 	r1_bio->read_disk = disk;  in raid1_sync_request()
3083 	struct raid1_info *disk;  in setup_conf()  local
3152 		disk = conf->mirrors + i;  in setup_conf()
3155 		    disk[conf->raid_disks].rdev) {  in setup_conf()
3157 			if (!disk->rdev) {  in setup_conf()
3161 				disk->rdev =  in setup_conf()
3162 					disk[conf->raid_disks].rdev;  in setup_conf()
3163 				disk[conf->raid_disks].rdev = NULL;  in setup_conf()
3164 			} else if (!test_bit(In_sync, &disk->rdev->flags))  in setup_conf()
3169 		if (!disk->rdev ||  in setup_conf()
3170 		    !test_bit(In_sync, &disk->rdev->flags)) {  in setup_conf()
3171 			disk->head_position = 0;  in setup_conf()
3172 			if (disk->rdev &&  in setup_conf()
3173 			    (disk->rdev->saved_raid_disk < 0))  in setup_conf()
3264 	 * RAID1 needs at least one disk in active  in raid1_run()