[PATCH 42/45] block: switch disk_part_iter_* to use a struct block_device

[Christoph Hellwig <hch@lst.de>]

Switch the partition iter infrastructure to iterate over block_device
references instead of hd_struct ones mostly used to get at the
block_device.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/genhd.c             | 57 +++++++++++++++++++--------------------
 block/partitions/core.c   | 13 +++++----
 drivers/s390/block/dasd.c |  8 +++---
 include/linux/genhd.h     |  4 +--
 4 files changed, 40 insertions(+), 42 deletions(-)

diff --git a/block/genhd.c b/block/genhd.c
index 2985740eab084b..f0bf10192066ac 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -231,7 +231,7 @@ EXPORT_SYMBOL_GPL(disk_part_iter_init);
  * CONTEXT:
  * Don't care.
  */
-struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter)
+struct block_device *disk_part_iter_next(struct disk_part_iter *piter)
 {
 	struct disk_part_tbl *ptbl;
 	int inc, end;
@@ -269,8 +269,7 @@ struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter)
 		      piter->idx == 0))
 			continue;
 
-		get_device(part_to_dev(part->bd_part));
-		piter->part = part->bd_part;
+		piter->part = bdgrab(part);
 		piter->idx += inc;
 		break;
 	}
@@ -292,7 +291,8 @@ EXPORT_SYMBOL_GPL(disk_part_iter_next);
  */
 void disk_part_iter_exit(struct disk_part_iter *piter)
 {
-	disk_put_part(piter->part);
+	if (piter->part)
+		bdput(piter->part);
 	piter->part = NULL;
 }
 EXPORT_SYMBOL_GPL(disk_part_iter_exit);
@@ -333,7 +333,6 @@ struct block_device *disk_map_sector_rcu(struct gendisk *disk, sector_t sector)
 
 	for (i = 1; i < ptbl->len; i++) {
 		part = rcu_dereference(ptbl->part[i]);
-
 		if (part && sector_in_part(part, sector)) {
 			rcu_assign_pointer(ptbl->last_lookup, part);
 			goto out_unlock;
@@ -634,7 +633,7 @@ static void register_disk(struct device *parent, struct gendisk *disk,
 {
 	struct device *ddev = disk_to_dev(disk);
 	struct disk_part_iter piter;
-	struct hd_struct *part;
+	struct block_device *part;
 	int err;
 
 	ddev->parent = parent;
@@ -684,7 +683,7 @@ static void register_disk(struct device *parent, struct gendisk *disk,
 	/* announce possible partitions */
 	disk_part_iter_init(&piter, disk, 0);
 	while ((part = disk_part_iter_next(&piter)))
-		kobject_uevent(&part_to_dev(part)->kobj, KOBJ_ADD);
+		kobject_uevent(bdev_kobj(part), KOBJ_ADD);
 	disk_part_iter_exit(&piter);
 
 	if (disk->queue->backing_dev_info->dev) {
@@ -824,7 +823,7 @@ static void invalidate_partition(struct block_device *bdev)
 void del_gendisk(struct gendisk *disk)
 {
 	struct disk_part_iter piter;
-	struct hd_struct *part;
+	struct block_device *part;
 
 	might_sleep();
 
@@ -840,8 +839,8 @@ void del_gendisk(struct gendisk *disk)
 	disk_part_iter_init(&piter, disk,
 			     DISK_PITER_INCL_EMPTY | DISK_PITER_REVERSE);
 	while ((part = disk_part_iter_next(&piter))) {
-		invalidate_partition(part->bdev);
-		delete_partition(part);
+		invalidate_partition(part);
+		delete_partition(part->bd_part);
 	}
 	disk_part_iter_exit(&piter);
 
@@ -958,7 +957,7 @@ void __init printk_all_partitions(void)
 	while ((dev = class_dev_iter_next(&iter))) {
 		struct gendisk *disk = dev_to_disk(dev);
 		struct disk_part_iter piter;
-		struct hd_struct *part;
+		struct block_device *part;
 		char name_buf[BDEVNAME_SIZE];
 		char devt_buf[BDEVT_SIZE];
 
@@ -977,14 +976,14 @@ void __init printk_all_partitions(void)
 		 */
 		disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
 		while ((part = disk_part_iter_next(&piter))) {
-			bool is_part0 = part == disk->part0->bd_part;
+			bool is_part0 = part == disk->part0;
 
 			printk("%s%s %10llu %s %s", is_part0 ? "" : "  ",
-			       bdevt_str(part_devt(part), devt_buf),
-			       bdev_nr_sectors(part->bdev) >> 1,
-			       disk_name(disk, part->bdev->bd_partno, name_buf),
-			       part->bdev->bd_meta_info ?
-					part->bdev->bd_meta_info->uuid : "");
+			       bdevt_str(part->bd_dev, devt_buf),
+			       bdev_nr_sectors(part) >> 1,
+			       disk_name(disk, part->bd_partno, name_buf),
+			       part->bd_meta_info ?
+					part->bd_meta_info->uuid : "");
 			if (is_part0) {
 				if (dev->parent && dev->parent->driver)
 					printk(" driver: %s\n",
@@ -1060,7 +1059,7 @@ static int show_partition(struct seq_file *seqf, void *v)
 {
 	struct gendisk *sgp = v;
 	struct disk_part_iter piter;
-	struct hd_struct *part;
+	struct block_device *part;
 	char buf[BDEVNAME_SIZE];
 
 	/* Don't show non-partitionable removeable devices or empty devices */
@@ -1074,9 +1073,9 @@ static int show_partition(struct seq_file *seqf, void *v)
 	disk_part_iter_init(&piter, sgp, DISK_PITER_INCL_PART0);
 	while ((part = disk_part_iter_next(&piter)))
 		seq_printf(seqf, "%4d  %7d %10llu %s\n",
-			   MAJOR(part_devt(part)), MINOR(part_devt(part)),
-			   bdev_nr_sectors(part->bdev) >> 1,
-			   disk_name(sgp, part->bdev->bd_partno, buf));
+			   MAJOR(part->bd_dev), MINOR(part->bd_dev),
+			   bdev_nr_sectors(part) >> 1,
+			   disk_name(sgp, part->bd_partno, buf));
 	disk_part_iter_exit(&piter);
 
 	return 0;
@@ -1470,7 +1469,7 @@ static int diskstats_show(struct seq_file *seqf, void *v)
 {
 	struct gendisk *gp = v;
 	struct disk_part_iter piter;
-	struct hd_struct *hd;
+	struct block_device *hd;
 	char buf[BDEVNAME_SIZE];
 	unsigned int inflight;
 	struct disk_stats stat;
@@ -1485,11 +1484,11 @@ static int diskstats_show(struct seq_file *seqf, void *v)
 
 	disk_part_iter_init(&piter, gp, DISK_PITER_INCL_EMPTY_PART0);
 	while ((hd = disk_part_iter_next(&piter))) {
-		part_stat_read_all(hd, &stat);
+		part_stat_read_all(hd->bd_part, &stat);
 		if (queue_is_mq(gp->queue))
-			inflight = blk_mq_in_flight(gp->queue, hd->bdev);
+			inflight = blk_mq_in_flight(gp->queue, hd);
 		else
-			inflight = part_in_flight(hd->bdev);
+			inflight = part_in_flight(hd);
 
 		seq_printf(seqf, "%4d %7d %s "
 			   "%lu %lu %lu %u "
@@ -1498,8 +1497,8 @@ static int diskstats_show(struct seq_file *seqf, void *v)
 			   "%lu %lu %lu %u "
 			   "%lu %u"
 			   "\n",
-			   MAJOR(part_devt(hd)), MINOR(part_devt(hd)),
-			   disk_name(gp, hd->bdev->bd_partno, buf),
+			   MAJOR(hd->bd_dev), MINOR(hd->bd_dev),
+			   disk_name(gp, hd->bd_partno, buf),
 			   stat.ios[STAT_READ],
 			   stat.merges[STAT_READ],
 			   stat.sectors[STAT_READ],
@@ -1654,7 +1653,7 @@ static void set_disk_ro_uevent(struct gendisk *gd, int ro)
 void set_disk_ro(struct gendisk *disk, int flag)
 {
 	struct disk_part_iter piter;
-	struct hd_struct *part;
+	struct block_device *part;
 
 	if (disk->part0->bd_read_only != flag) {
 		set_disk_ro_uevent(disk, flag);
@@ -1663,7 +1662,7 @@ void set_disk_ro(struct gendisk *disk, int flag)
 
 	disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY);
 	while ((part = disk_part_iter_next(&piter)))
-		part->bdev->bd_read_only = flag;
+		part->bd_read_only = flag;
 	disk_part_iter_exit(&piter);
 }
 
diff --git a/block/partitions/core.c b/block/partitions/core.c
index 45fed1108d4425..c189ebd4569812 100644
--- a/block/partitions/core.c
+++ b/block/partitions/core.c
@@ -439,15 +439,14 @@ static bool partition_overlaps(struct gendisk *disk, sector_t start,
 		sector_t length, int skip_partno)
 {
 	struct disk_part_iter piter;
-	struct hd_struct *part;
+	struct block_device *part;
 	bool overlap = false;
 
 	disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY);
 	while ((part = disk_part_iter_next(&piter))) {
-		if (part->bdev->bd_partno == skip_partno ||
-		    start >= part->bdev->bd_start_sect +
-			bdev_nr_sectors(part->bdev) ||
-		    start + length <= part->bdev->bd_start_sect)
+		if (part->bd_partno == skip_partno ||
+		    start >= part->bd_start_sect + bdev_nr_sectors(part) ||
+		    start + length <= part->bd_start_sect)
 			continue;
 		overlap = true;
 		break;
@@ -568,7 +567,7 @@ static bool disk_unlock_native_capacity(struct gendisk *disk)
 int blk_drop_partitions(struct block_device *bdev)
 {
 	struct disk_part_iter piter;
-	struct hd_struct *part;
+	struct block_device *part;
 
 	if (bdev->bd_part_count)
 		return -EBUSY;
@@ -578,7 +577,7 @@ int blk_drop_partitions(struct block_device *bdev)
 
 	disk_part_iter_init(&piter, bdev->bd_disk, DISK_PITER_INCL_EMPTY);
 	while ((part = disk_part_iter_next(&piter)))
-		delete_partition(part);
+		delete_partition(part->bd_part);
 	disk_part_iter_exit(&piter);
 
 	return 0;
diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c
index db24e04ee9781e..1825fa8d05a780 100644
--- a/drivers/s390/block/dasd.c
+++ b/drivers/s390/block/dasd.c
@@ -432,7 +432,7 @@ dasd_state_ready_to_online(struct dasd_device * device)
 {
 	struct gendisk *disk;
 	struct disk_part_iter piter;
-	struct hd_struct *part;
+	struct block_device *part;
 
 	device->state = DASD_STATE_ONLINE;
 	if (device->block) {
@@ -445,7 +445,7 @@ dasd_state_ready_to_online(struct dasd_device * device)
 		disk = device->block->bdev->bd_disk;
 		disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
 		while ((part = disk_part_iter_next(&piter)))
-			kobject_uevent(&part_to_dev(part)->kobj, KOBJ_CHANGE);
+			kobject_uevent(bdev_kobj(part), KOBJ_CHANGE);
 		disk_part_iter_exit(&piter);
 	}
 	return 0;
@@ -459,7 +459,7 @@ static int dasd_state_online_to_ready(struct dasd_device *device)
 	int rc;
 	struct gendisk *disk;
 	struct disk_part_iter piter;
-	struct hd_struct *part;
+	struct block_device *part;
 
 	if (device->discipline->online_to_ready) {
 		rc = device->discipline->online_to_ready(device);
@@ -472,7 +472,7 @@ static int dasd_state_online_to_ready(struct dasd_device *device)
 		disk = device->block->bdev->bd_disk;
 		disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
 		while ((part = disk_part_iter_next(&piter)))
-			kobject_uevent(&part_to_dev(part)->kobj, KOBJ_CHANGE);
+			kobject_uevent(bdev_kobj(part), KOBJ_CHANGE);
 		disk_part_iter_exit(&piter);
 	}
 	return 0;
diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index afe27a0b8f5dd8..de2ee5ffeefe45 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -245,14 +245,14 @@ static inline void disk_put_part(struct hd_struct *part)
 
 struct disk_part_iter {
 	struct gendisk		*disk;
-	struct hd_struct	*part;
+	struct block_device	*part;
 	int			idx;
 	unsigned int		flags;
 };
 
 extern void disk_part_iter_init(struct disk_part_iter *piter,
 				 struct gendisk *disk, unsigned int flags);
-extern struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter);
+struct block_device *disk_part_iter_next(struct disk_part_iter *piter);
 extern void disk_part_iter_exit(struct disk_part_iter *piter);
 extern bool disk_has_partitions(struct gendisk *disk);
 
-- 
2.29.2