On Thu 26-11-20 14:04:08, Christoph Hellwig wrote:
> Move the dkstats and stamp field to struct block_device in preparation
> of killing struct hd_struct.
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Looks good. You can add:
Reviewed-by: Jan Kara <jack@xxxxxxx>
Honza
> ---
> block/blk-cgroup.c | 2 +-
> block/blk-core.c | 4 ++--
> block/blk.h | 1 -
> block/genhd.c | 14 ++++----------
> block/partitions/core.c | 9 +--------
> fs/block_dev.c | 10 ++++++++++
> include/linux/blk_types.h | 2 ++
> include/linux/genhd.h | 2 --
> include/linux/part_stat.h | 38 +++++++++++++++++++-------------------
> 9 files changed, 39 insertions(+), 43 deletions(-)
>
> diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
> index 19650eb42b9f00..5c0a9d588e6312 100644
> --- a/block/blk-cgroup.c
> +++ b/block/blk-cgroup.c
> @@ -830,7 +830,7 @@ static void blkcg_fill_root_iostats(void)
> for_each_possible_cpu(cpu) {
> struct disk_stats *cpu_dkstats;
>
> - cpu_dkstats = per_cpu_ptr(part->dkstats, cpu);
> + cpu_dkstats = per_cpu_ptr(part->bdev->bd_stats, cpu);
> tmp.ios[BLKG_IOSTAT_READ] +=
> cpu_dkstats->ios[STAT_READ];
> tmp.ios[BLKG_IOSTAT_WRITE] +=
> diff --git a/block/blk-core.c b/block/blk-core.c
> index 988f45094a387b..d2c9cb24e087f3 100644
> --- a/block/blk-core.c
> +++ b/block/blk-core.c
> @@ -1264,9 +1264,9 @@ static void update_io_ticks(struct hd_struct *part, unsigned long now, bool end)
> {
> unsigned long stamp;
> again:
> - stamp = READ_ONCE(part->stamp);
> + stamp = READ_ONCE(part->bdev->bd_stamp);
> if (unlikely(stamp != now)) {
> - if (likely(cmpxchg(&part->stamp, stamp, now) == stamp))
> + if (likely(cmpxchg(&part->bdev->bd_stamp, stamp, now) == stamp))
> __part_stat_add(part, io_ticks, end ? now - stamp : 1);
> }
> if (part->partno) {
> diff --git a/block/blk.h b/block/blk.h
> index 09cee7024fb43e..3f801f6e86f8a1 100644
> --- a/block/blk.h
> +++ b/block/blk.h
> @@ -381,7 +381,6 @@ static inline void hd_struct_put(struct hd_struct *part)
>
> static inline void hd_free_part(struct hd_struct *part)
> {
> - free_percpu(part->dkstats);
> kfree(part->info);
> bdput(part->bdev);
> percpu_ref_exit(&part->ref);
> diff --git a/block/genhd.c b/block/genhd.c
> index c6016fde4725b0..9eead2970cb3d4 100644
> --- a/block/genhd.c
> +++ b/block/genhd.c
> @@ -104,7 +104,7 @@ static void part_stat_read_all(struct hd_struct *part, struct disk_stats *stat)
>
> memset(stat, 0, sizeof(struct disk_stats));
> for_each_possible_cpu(cpu) {
> - struct disk_stats *ptr = per_cpu_ptr(part->dkstats, cpu);
> + struct disk_stats *ptr = per_cpu_ptr(part->bdev->bd_stats, cpu);
> int group;
>
> for (group = 0; group < NR_STAT_GROUPS; group++) {
> @@ -883,7 +883,7 @@ void del_gendisk(struct gendisk *disk)
> kobject_put(disk->slave_dir);
>
> part_stat_set_all(&disk->part0, 0);
> - disk->part0.stamp = 0;
> + disk->part0.bdev->bd_stamp = 0;
> if (!sysfs_deprecated)
> sysfs_remove_link(block_depr, dev_name(disk_to_dev(disk)));
> pm_runtime_set_memalloc_noio(disk_to_dev(disk), false);
> @@ -1620,19 +1620,15 @@ struct gendisk *__alloc_disk_node(int minors, int node_id)
> if (!disk->part0.bdev)
> goto out_free_disk;
>
> - disk->part0.dkstats = alloc_percpu(struct disk_stats);
> - if (!disk->part0.dkstats)
> - goto out_bdput;
> -
> disk->node_id = node_id;
> if (disk_expand_part_tbl(disk, 0))
> - goto out_free_bdstats;
> + goto out_bdput;
>
> ptbl = rcu_dereference_protected(disk->part_tbl, 1);
> rcu_assign_pointer(ptbl->part[0], &disk->part0);
>
> if (hd_ref_init(&disk->part0))
> - goto out_free_bdstats;
> + goto out_bdput;
>
> disk->minors = minors;
> rand_initialize_disk(disk);
> @@ -1641,8 +1637,6 @@ struct gendisk *__alloc_disk_node(int minors, int node_id)
> device_initialize(disk_to_dev(disk));
> return disk;
>
> -out_free_bdstats:
> - free_percpu(disk->part0.dkstats);
> out_bdput:
> bdput(disk->part0.bdev);
> out_free_disk:
> diff --git a/block/partitions/core.c b/block/partitions/core.c
> index bcfa8215bd5ef3..8924e1ea8b2ad6 100644
> --- a/block/partitions/core.c
> +++ b/block/partitions/core.c
> @@ -409,14 +409,9 @@ static struct hd_struct *add_partition(struct gendisk *disk, int partno,
> if (!p)
> return ERR_PTR(-EBUSY);
>
> - err = -ENOMEM;
> - p->dkstats = alloc_percpu(struct disk_stats);
> - if (!p->dkstats)
> - goto out_free;
> -
> bdev = bdev_alloc(disk, partno);
> if (!bdev)
> - goto out_free_stats;
> + goto out_free;
> p->bdev = bdev;
>
> pdev = part_to_dev(p);
> @@ -490,8 +485,6 @@ static struct hd_struct *add_partition(struct gendisk *disk, int partno,
> kfree(p->info);
> out_bdput:
> bdput(bdev);
> -out_free_stats:
> - free_percpu(p->dkstats);
> out_free:
> kfree(p);
> return ERR_PTR(err);
> diff --git a/fs/block_dev.c b/fs/block_dev.c
> index b6ebfb7754d3b7..11e6a9a255845d 100644
> --- a/fs/block_dev.c
> +++ b/fs/block_dev.c
> @@ -32,6 +32,7 @@
> #include <linux/cleancache.h>
> #include <linux/task_io_accounting_ops.h>
> #include <linux/falloc.h>
> +#include <linux/part_stat.h>
> #include <linux/uaccess.h>
> #include <linux/suspend.h>
> #include "internal.h"
> @@ -781,6 +782,10 @@ static struct inode *bdev_alloc_inode(struct super_block *sb)
>
> static void bdev_free_inode(struct inode *inode)
> {
> + struct block_device *bdev = I_BDEV(inode);
> +
> + free_percpu(bdev->bd_stats);
> +
> kmem_cache_free(bdev_cachep, BDEV_I(inode));
> }
>
> @@ -875,6 +880,11 @@ struct block_device *bdev_alloc(struct gendisk *disk, u8 partno)
> #ifdef CONFIG_SYSFS
> INIT_LIST_HEAD(&bdev->bd_holder_disks);
> #endif
> + bdev->bd_stats = alloc_percpu(struct disk_stats);
> + if (!bdev->bd_stats) {
> + iput(inode);
> + return NULL;
> + }
> return bdev;
> }
>
> diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
> index 2e0a9bd9688d28..520011b95276fb 100644
> --- a/include/linux/blk_types.h
> +++ b/include/linux/blk_types.h
> @@ -20,6 +20,8 @@ typedef void (bio_end_io_t) (struct bio *);
> struct bio_crypt_ctx;
>
> struct block_device {
> + struct disk_stats __percpu *bd_stats;
> + unsigned long bd_stamp;
> dev_t bd_dev;
> int bd_openers;
> struct inode * bd_inode; /* will die */
> diff --git a/include/linux/genhd.h b/include/linux/genhd.h
> index 30d4785b7df8bb..804ac45fbfbc53 100644
> --- a/include/linux/genhd.h
> +++ b/include/linux/genhd.h
> @@ -52,8 +52,6 @@ struct partition_meta_info {
>
> struct hd_struct {
> sector_t start_sect;
> - unsigned long stamp;
> - struct disk_stats __percpu *dkstats;
> struct percpu_ref ref;
>
> struct block_device *bdev;
> diff --git a/include/linux/part_stat.h b/include/linux/part_stat.h
> index 24125778ef3ec7..87ad60106e1db0 100644
> --- a/include/linux/part_stat.h
> +++ b/include/linux/part_stat.h
> @@ -25,17 +25,17 @@ struct disk_stats {
> #define part_stat_unlock() preempt_enable()
>
> #define part_stat_get_cpu(part, field, cpu) \
> - (per_cpu_ptr((part)->dkstats, (cpu))->field)
> + (per_cpu_ptr((part)->bdev->bd_stats, (cpu))->field)
>
> #define part_stat_get(part, field) \
> part_stat_get_cpu(part, field, smp_processor_id())
>
> #define part_stat_read(part, field) \
> ({ \
> - typeof((part)->dkstats->field) res = 0; \
> + typeof((part)->bdev->bd_stats->field) res = 0; \
> unsigned int _cpu; \
> for_each_possible_cpu(_cpu) \
> - res += per_cpu_ptr((part)->dkstats, _cpu)->field; \
> + res += per_cpu_ptr((part)->bdev->bd_stats, _cpu)->field; \
> res; \
> })
>
> @@ -44,7 +44,7 @@ static inline void part_stat_set_all(struct hd_struct *part, int value)
> int i;
>
> for_each_possible_cpu(i)
> - memset(per_cpu_ptr(part->dkstats, i), value,
> + memset(per_cpu_ptr(part->bdev->bd_stats, i), value,
> sizeof(struct disk_stats));
> }
>
> @@ -54,7 +54,7 @@ static inline void part_stat_set_all(struct hd_struct *part, int value)
> part_stat_read(part, field[STAT_DISCARD]))
>
> #define __part_stat_add(part, field, addnd) \
> - __this_cpu_add((part)->dkstats->field, addnd)
> + __this_cpu_add((part)->bdev->bd_stats->field, addnd)
>
> #define part_stat_add(part, field, addnd) do { \
> __part_stat_add((part), field, addnd); \
> @@ -63,20 +63,20 @@ static inline void part_stat_set_all(struct hd_struct *part, int value)
> field, addnd); \
> } while (0)
>
> -#define part_stat_dec(gendiskp, field) \
> - part_stat_add(gendiskp, field, -1)
> -#define part_stat_inc(gendiskp, field) \
> - part_stat_add(gendiskp, field, 1)
> -#define part_stat_sub(gendiskp, field, subnd) \
> - part_stat_add(gendiskp, field, -subnd)
> +#define part_stat_dec(part, field) \
> + part_stat_add(part, field, -1)
> +#define part_stat_inc(part, field) \
> + part_stat_add(part, field, 1)
> +#define part_stat_sub(part, field, subnd) \
> + part_stat_add(part, field, -subnd)
>
> -#define part_stat_local_dec(gendiskp, field) \
> - local_dec(&(part_stat_get(gendiskp, field)))
> -#define part_stat_local_inc(gendiskp, field) \
> - local_inc(&(part_stat_get(gendiskp, field)))
> -#define part_stat_local_read(gendiskp, field) \
> - local_read(&(part_stat_get(gendiskp, field)))
> -#define part_stat_local_read_cpu(gendiskp, field, cpu) \
> - local_read(&(part_stat_get_cpu(gendiskp, field, cpu)))
> +#define part_stat_local_dec(part, field) \
> + local_dec(&(part_stat_get(part, field)))
> +#define part_stat_local_inc(part, field) \
> + local_inc(&(part_stat_get(part, field)))
> +#define part_stat_local_read(part, field) \
> + local_read(&(part_stat_get(part, field)))
> +#define part_stat_local_read_cpu(part, field, cpu) \
> + local_read(&(part_stat_get_cpu(part, field, cpu)))
>
> #endif /* _LINUX_PART_STAT_H */
> --
> 2.29.2
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
