From: Christoph Hellwig <hch@lst.de> mainline inclusion from mainline-5.6-rc1 commit fc8f19cc5dce183cde4fecb9a1da07d81fa6ea8d category: feature bugzilla: 43003 CVE: NA --------------------------- Avoid an extra reference count roundtrip by transferring the sb_page ownership to the lower level register helpers. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> Acked-by: Hanjun Guo <guohanjun@huawei.com> Reviewed-by: Yufen Yu <yuyufen@huawei.com> Signed-off-by: zhangyi (F) <yi.zhang@huawei.com> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- drivers/md/bcache/super.c | 21 ++++++--------------- 1 file changed, 6 insertions(+), 15 deletions(-) diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c index d0c19f9dcbdc..ce86fa7c70a6 100644 --- a/drivers/md/bcache/super.c +++ b/drivers/md/bcache/super.c @@ -1371,8 +1371,6 @@ static int register_bdev(struct cache_sb *sb, struct page *sb_page, bio_init(&dc->sb_bio, dc->sb_bio.bi_inline_vecs, 1); bio_first_bvec_all(&dc->sb_bio)->bv_page = sb_page; - get_page(sb_page); - if (cached_dev_init(dc, sb->block_size << 9)) goto err; @@ -2268,7 +2266,6 @@ static int register_cache(struct cache_sb *sb, struct page *sb_page, bio_init(&ca->sb_bio, ca->sb_bio.bi_inline_vecs, 1); bio_first_bvec_all(&ca->sb_bio)->bv_page = sb_page; - get_page(sb_page); if (blk_queue_discard(bdev_get_queue(bdev))) ca->discard = CACHE_DISCARD(&ca->sb); @@ -2371,7 +2368,7 @@ static ssize_t register_bcache(struct kobject *k, struct kobj_attribute *attr, const char *err; char *path = NULL; struct cache_sb *sb; - struct block_device *bdev = NULL; + struct block_device *bdev; struct page *sb_page; ssize_t ret; @@ -2437,10 +2434,8 @@ static ssize_t register_bcache(struct kobject *k, struct kobj_attribute *attr, ret = register_bdev(sb, sb_page, bdev, dc); mutex_unlock(&bch_register_lock); /* blkdev_put() will be called in cached_dev_free() */ - if (ret < 0) { - bdev = NULL; - goto out_put_sb_page; - } + if (ret < 0) + goto out_free_sb; } else { struct cache *ca = kzalloc(sizeof(*ca), GFP_KERNEL); @@ -2448,13 +2443,10 @@ static ssize_t register_bcache(struct kobject *k, struct kobj_attribute *attr, goto out_put_sb_page; /* blkdev_put() will be called in bch_cache_release() */ - if (register_cache(sb, sb_page, bdev, ca) != 0) { - bdev = NULL; - goto out_put_sb_page; - } + if (register_cache(sb, sb_page, bdev, ca) != 0) + goto out_free_sb; } - put_page(sb_page); done: kfree(sb); kfree(path); @@ -2464,8 +2456,7 @@ static ssize_t register_bcache(struct kobject *k, struct kobj_attribute *attr, out_put_sb_page: put_page(sb_page); out_blkdev_put: - if (bdev) - blkdev_put(bdev, FMODE_READ | FMODE_WRITE | FMODE_EXCL); + blkdev_put(bdev, FMODE_READ | FMODE_WRITE | FMODE_EXCL); out_free_sb: kfree(sb); out_free_path: -- 2.25.1