diff options
| author | Ming Lei <ming.lei@redhat.com> | 2020-05-08 16:17:58 +0800 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2020-05-12 20:31:40 -0600 |
| commit | 27eb3af9a37a85ca35f82830a8fc29753700058a (patch) | |
| tree | 5f0cc279819eb461e5ef994b862c44b4186b26f8 | |
| parent | 520138c3b9425c615d1417687947d86821003319 (diff) | |
block: don't hold part0's refcount in IO path
gendisk can't be gone when there is IO activity, so not hold
part0's refcount in IO path.
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>
| -rw-r--r-- | block/blk.h | 13 | ||||
| -rw-r--r-- | block/genhd.c | 4 |
2 files changed, 8 insertions, 9 deletions
diff --git a/block/blk.h b/block/blk.h index 73bd3b1c6938..8c3f557dd898 100644 --- a/block/blk.h +++ b/block/blk.h @@ -378,19 +378,18 @@ int bdev_resize_partition(struct block_device *bdev, int partno, int disk_expand_part_tbl(struct gendisk *disk, int target); int hd_ref_init(struct hd_struct *part); -static inline void hd_struct_get(struct hd_struct *part) -{ - percpu_ref_get(&part->ref); -} - +/* no need to get/put refcount of part0 */ static inline int hd_struct_try_get(struct hd_struct *part) { - return percpu_ref_tryget_live(&part->ref); + if (part->partno) + return percpu_ref_tryget_live(&part->ref); + return 1; } static inline void hd_struct_put(struct hd_struct *part) { - percpu_ref_put(&part->ref); + if (part->partno) + percpu_ref_put(&part->ref); } static inline void hd_free_part(struct hd_struct *part) diff --git a/block/genhd.c b/block/genhd.c index 1a51a9ad1035..afdb2c3e5b22 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -345,7 +345,8 @@ static inline int sector_in_part(struct hd_struct *part, sector_t sector) * * CONTEXT: * RCU read locked. The returned partition pointer is always valid - * because its refcount is grabbed. + * because its refcount is grabbed except for part0, which lifetime + * is same with the disk. * * RETURNS: * Found partition on success, part0 is returned if no partition matches @@ -378,7 +379,6 @@ struct hd_struct *disk_map_sector_rcu(struct gendisk *disk, sector_t sector) return part; } } - hd_struct_get(&disk->part0); return &disk->part0; } |