From: Ming Lei <ming.lei@redhat.com>
Date: Fri, 8 May 2020 16:17:56 +0800
Subject: [PATCH] block: only define 'nr_sects_seq' in hd_part for 32bit SMP
References: bsc#1175995,jsc#SLE-15608
Git-commit: 07c4e1e834f8e7c991aa6dcb5ee0b7f2842e495d
Patch-mainline: v5.8-rc1
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>
Signed-off-by: Hannes Reinecke <hare@suse.de>
---
block/genhd.c | 2 +-
block/partitions/core.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 f6ed9f246f66..004263668330 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -1718,7 +1718,7 @@ 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/partitions/core.c b/block/partitions/core.c
index edd5527390b2..e1673b1fa233 100644
--- a/block/partitions/core.c
+++ b/block/partitions/core.c
@@ -383,7 +383,7 @@ 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 a80bc3eaeb0d..627a2e091d0e 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -111,7 +111,9 @@ 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;
@@ -261,6 +263,13 @@ 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.
*/
--
2.16.4