block: only define 'nr_sects_seq' in hd_part for 32bit SMP
The seqcount of 'nr_sects_seq' is only needed in case of 32bit SMP,
so define it just for 32bit SMP.
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@infradead.org>
Cc: Yufen Yu <yuyufen@huawei.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Hou Tao <houtao1@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index f9c226f..b474403 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -68,7 +68,9 @@ 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;
@@ -274,6 +276,13 @@ static inline void disk_put_part(struct hd_struct *part)
put_device(part_to_dev(part));
}
+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
+}
+
/*
* Smarter partition iterator without context limits.
*/