block: move disk stat accounting to struct block_device

Move the dkstats and stamp 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>

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index ad02289..79aa962 100644 (file)
--- 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 988f450..d2c9cb2 100644 (file)
--- 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 09cee70..3f801f6 100644 (file)
--- 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 c65f485..2cbda81 100644 (file)
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -112,7 +112,7 @@ 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++) {
@@ -891,7 +891,7 @@ 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);
@@ -1628,19 +1628,15 @@ 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);
@@ -1649,8 +1645,6 @@ 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 bcfa821..8924e1e 100644 (file)
--- 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 @@ out_free_info:
        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 31ee5a8..0832c78 100644 (file)
--- 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 2e0a9bd..520011b 100644 (file)
--- 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 30d4785..804ac45 100644 (file)
--- 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 2412577..87ad601 100644 (file)
--- 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 */