The seqcount of 'nr_sects_seq' is only needed in case of 32bit SMP,
so define it just for 32bit SMP.
Cc: Yufen Yu <yuyufen@xxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx>
Cc: Hou Tao <houtao1@xxxxxxxxxx>
Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx>
---
block/genhd.c | 2 +-
block/partition-generic.c | 2 +-
include/linux/genhd.h | 9 +++++++++
3 files changed, 11 insertions(+), 2 deletions(-)
diff --git a/block/genhd.c b/block/genhd.c
index 6029c94510f0..bfc4148ec341 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -1506,7 +1506,7 @@ struct gendisk *__alloc_disk_node(int minors, int node_id)
* TODO: Ideally set_capacity() and get_capacity() should be
* converted to make use of bd_mutex and sequence counters.
*/
- seqcount_init(&disk->part0.nr_sects_seq);
+ hd_sects_seq_init(&disk->part0);
if (hd_ref_init(&disk->part0)) {
hd_free_part(&disk->part0);
kfree(disk);
diff --git a/block/partition-generic.c b/block/partition-generic.c
index 1739f750dbf2..eb606c2c3d6c 100644
--- a/block/partition-generic.c
+++ b/block/partition-generic.c
@@ -345,7 +345,7 @@ struct hd_struct *add_partition(struct gendisk *disk, int partno,
goto out_free;
}
- seqcount_init(&p->nr_sects_seq);
+ hd_sects_seq_init(p);
pdev = part_to_dev(p);
p->start_sect = start;
diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index 1b09cfe00aa3..5f5718ce5e86 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -113,7 +113,9 @@ struct hd_struct {
* can be non-atomic on 32bit machines with 64bit sector_t.
*/
sector_t nr_sects;
+#if BITS_PER_LONG==32 && defined(CONFIG_SMP)
seqcount_t nr_sects_seq;
+#endif
sector_t alignment_offset;
unsigned int discard_alignment;
struct device __dev;
@@ -713,6 +715,13 @@ static inline void hd_free_part(struct hd_struct *part)
percpu_ref_exit(&part->ref);
}
+static inline void hd_sects_seq_init(struct hd_struct *p)
+{
+#if BITS_PER_LONG==32 && defined(CONFIG_SMP)
+ seqcount_init(&p->nr_sects_seq);
+#endif
+}
+
/*
* Any access of part->nr_sects which is not protected by partition
* bd_mutex or gendisk bdev bd_mutex, should be done using this
--
2.20.1
