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

Jan Kara
2020-11-30T10:21:05Z

On Sat 28-11-20 17:15:07, Christoph Hellwig wrote:
> 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>

Looks good to me. Feel free to add:

Reviewed-by: Jan Kara <jack@suse.cz>

Honza

> ---
> block/genhd.c | 59 ++++++++++++++++++++-------------------
> block/partitions/core.c | 13 ++++-----
> drivers/s390/block/dasd.c | 8 +++---
> include/linux/genhd.h | 4 +--
> 4 files changed, 42 insertions(+), 42 deletions(-)
>
> diff --git a/block/genhd.c b/block/genhd.c
> index 28ced566c07bb7..e83174818b543a 100644
> --- a/block/genhd.c
> +++ b/block/genhd.c
> @@ -236,7 +236,7 @@ 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;
> @@ -274,8 +274,9 @@ 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);
> + if (!piter->part)
> + continue;
> piter->idx += inc;
> break;
> }
> @@ -297,7 +298,8 @@ 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);
> @@ -338,7 +340,6 @@ 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;
> @@ -639,7 +640,7 @@ 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;
> @@ -689,7 +690,7 @@ 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) {
> @@ -829,7 +830,7 @@ 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();
>
> @@ -849,8 +850,8 @@ 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);
>
> @@ -969,7 +970,7 @@ 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];
>
> @@ -988,14 +989,14 @@ 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",
> @@ -1071,7 +1072,7 @@ 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 */
> @@ -1085,9 +1086,9 @@ 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;
> @@ -1481,7 +1482,7 @@ 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;
> @@ -1496,11 +1497,11 @@ 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 "
> @@ -1509,8 +1510,8 @@ 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],
> @@ -1665,7 +1666,7 @@ 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);
> @@ -1674,7 +1675,7 @@ 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 3d8243334c7cb4..4cb6df175f9077 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 3c13d4708e3f9d..cd23c80265b2b2 100644
> --- a/include/linux/genhd.h
> +++ b/include/linux/genhd.h
> @@ -244,14 +244,14 @@ 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
>
--
Jan Kara <jack@suse.com>
SUSE Labs, CR