block: move the start_sect field to struct block_device

Move the start_sect field to struct block_device in preparation
of killing struct hd_struct.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/blk-core.c

@@ -757,9 +757,10 @@ static inline int blk_partition_remap(struct bio *bio)
 	if (bio_sectors(bio)) {
 		if (bio_check_eod(bio, bdev_nr_sectors(p->bdev)))
 			goto out;
-		bio->bi_iter.bi_sector += p->start_sect;
+		bio->bi_iter.bi_sector += p->bdev->bd_start_sect;
 		trace_block_bio_remap(bio->bi_disk->queue, bio, part_devt(p),
-				      bio->bi_iter.bi_sector - p->start_sect);
+				      bio->bi_iter.bi_sector -
+				      p->bdev->bd_start_sect);
 	}
 	bio->bi_partno = 0;
 	ret = 0;

block/blk-lib.c

@@ -65,7 +65,7 @@ int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 
 	/* In case the discard request is in a partition */
 	if (bdev_is_partition(bdev))
-		part_offset = bdev->bd_part->start_sect;
+		part_offset = bdev->bd_start_sect;
 
 	while (nr_sects) {
 		sector_t granularity_aligned_lba, req_sects;

block/genhd.c

@@ -305,8 +305,8 @@ EXPORT_SYMBOL_GPL(disk_part_iter_exit);
 
 static inline int sector_in_part(struct hd_struct *part, sector_t sector)
 {
-	return part->start_sect <= sector &&
+	return part->bdev->bd_start_sect <= sector &&
-		sector < part->start_sect + bdev_nr_sectors(part->bdev);
+		sector < part->bdev->bd_start_sect + bdev_nr_sectors(part->bdev);
 }
 
 /**

block/partitions/core.c

@@ -192,7 +192,7 @@ static ssize_t part_start_show(struct device *dev,
 {
 	struct hd_struct *p = dev_to_part(dev);
 
-	return sprintf(buf, "%llu\n",(unsigned long long)p->start_sect);
+	return sprintf(buf, "%llu\n", p->bdev->bd_start_sect);
 }
 
 static ssize_t part_ro_show(struct device *dev,
@@ -209,7 +209,7 @@ static ssize_t part_alignment_offset_show(struct device *dev,
 
 	return sprintf(buf, "%u\n",
 		queue_limit_alignment_offset(&part_to_disk(p)->queue->limits,
-				p->start_sect));
+				p->bdev->bd_start_sect));
 }
 
 static ssize_t part_discard_alignment_show(struct device *dev,
@@ -219,7 +219,7 @@ static ssize_t part_discard_alignment_show(struct device *dev,
 
 	return sprintf(buf, "%u\n",
 		queue_limit_discard_alignment(&part_to_disk(p)->queue->limits,
-				p->start_sect));
+				p->bdev->bd_start_sect));
 }
 
 static DEVICE_ATTR(partition, 0444, part_partition_show, NULL);
@@ -301,7 +301,7 @@ static void hd_struct_free_work(struct work_struct *work)
 	 */
 	put_device(disk_to_dev(disk));
 
-	part->start_sect = 0;
+	part->bdev->bd_start_sect = 0;
 	bdev_set_nr_sectors(part->bdev, 0);
 	part_stat_set_all(part, 0);
 	put_device(part_to_dev(part));
@@ -416,7 +416,7 @@ static struct hd_struct *add_partition(struct gendisk *disk, int partno,
 
 	pdev = part_to_dev(p);
 
-	p->start_sect = start;
+	bdev->bd_start_sect = start;
 	bdev_set_nr_sectors(bdev, len);
 	p->partno = partno;
 	p->policy = get_disk_ro(disk);
@@ -508,8 +508,9 @@ static bool partition_overlaps(struct gendisk *disk, sector_t start,
 	disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY);
 	while ((part = disk_part_iter_next(&piter))) {
 		if (part->partno == skip_partno ||
-		    start >= part->start_sect + bdev_nr_sectors(part->bdev) ||
+		    start >= part->bdev->bd_start_sect +
-		    start + length <= part->start_sect)
+			bdev_nr_sectors(part->bdev) ||
+		    start + length <= part->bdev->bd_start_sect)
 			continue;
 		overlap = true;
 		break;
@@ -592,7 +593,7 @@ int bdev_resize_partition(struct block_device *bdev, int partno,
 	mutex_lock_nested(&bdev->bd_mutex, 1);
 
 	ret = -EINVAL;
-	if (start != part->start_sect)
+	if (start != part->bdev->bd_start_sect)
 		goto out_unlock;
 
 	ret = -EBUSY;

include/linux/blk_types.h

@@ -20,6 +20,7 @@ typedef void (bio_end_io_t) (struct bio *);
 struct bio_crypt_ctx;
 
 struct block_device {
+	sector_t		bd_start_sect;
 	struct disk_stats __percpu *bd_stats;
 	unsigned long		bd_stamp;
 	dev_t			bd_dev;

include/linux/blkdev.h

@@ -1488,7 +1488,7 @@ static inline int bdev_alignment_offset(struct block_device *bdev)
 		return -1;
 	if (bdev_is_partition(bdev))
 		return queue_limit_alignment_offset(&q->limits,
-				bdev->bd_part->start_sect);
+				bdev->bd_start_sect);
 	return q->limits.alignment_offset;
 }
 
@@ -1529,7 +1529,7 @@ static inline int bdev_discard_alignment(struct block_device *bdev)
 
 	if (bdev_is_partition(bdev))
 		return queue_limit_discard_alignment(&q->limits,
-				bdev->bd_part->start_sect);
+				bdev->bd_start_sect);
 	return q->limits.discard_alignment;
 }
 

include/linux/genhd.h

@@ -51,7 +51,6 @@ struct partition_meta_info {
 };
 
 struct hd_struct {
-	sector_t start_sect;
 	struct percpu_ref ref;
 
 	struct block_device *bdev;
@@ -298,7 +297,7 @@ extern void rand_initialize_disk(struct gendisk *disk);
 
 static inline sector_t get_start_sect(struct block_device *bdev)
 {
-	return bdev->bd_part->start_sect;
+	return bdev->bd_start_sect;
 }
 
 static inline sector_t bdev_nr_sectors(struct block_device *bdev)

kernel/trace/blktrace.c

@@ -458,14 +458,9 @@ static struct rchan_callbacks blk_relay_callbacks = {
 static void blk_trace_setup_lba(struct blk_trace *bt,
 				struct block_device *bdev)
 {
-	struct hd_struct *part = NULL;
+	if (bdev) {
-
+		bt->start_lba = bdev->bd_start_sect;
-	if (bdev)
+		bt->end_lba = bdev->bd_start_sect + bdev_nr_sectors(bdev);
-		part = bdev->bd_part;
-
-	if (part) {
-		bt->start_lba = part->start_sect;
-		bt->end_lba = part->start_sect + bdev_nr_sectors(bdev);
 	} else {
 		bt->start_lba = 0;
 		bt->end_lba = -1ULL;