[PATCH 8/8] mtd_blkdevs: simplify the refcounting in blktrans_{open, release}

Christoph Hellwig
2021-08-23T07:41:10Z

Always grab a reference to the mtd_blktrans_dev in ->open instead of
just on the first open, and do away with the additional temporary
references in ->open and ->release.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
drivers/mtd/mtd_blkdevs.c | 18 ++++--------------
1 file changed, 4 insertions(+), 14 deletions(-)

diff --git a/drivers/mtd/mtd_blkdevs.c b/drivers/mtd/mtd_blkdevs.c
index 012c0966010a..b8ae1ec14e17 100644
--- a/drivers/mtd/mtd_blkdevs.c
+++ b/drivers/mtd/mtd_blkdevs.c
@@ -36,14 +36,6 @@ static void blktrans_dev_release(struct kref *kref)
kfree(dev);
}

-static struct mtd_blktrans_dev *blktrans_dev_get(struct gendisk *disk)
-{
- struct mtd_blktrans_dev *dev = disk->private_data;
-
- kref_get(&dev->ref);
- return dev;
-}
-
static void blktrans_dev_put(struct mtd_blktrans_dev *dev)
{
kref_put(&dev->ref, blktrans_dev_release);
@@ -191,15 +183,16 @@ static blk_status_t mtd_queue_rq(struct blk_mq_hw_ctx *hctx,

static int blktrans_open(struct block_device *bdev, fmode_t mode)
{
- struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk);
+ struct mtd_blktrans_dev *dev = bdev->bd_disk->private_data;
int ret = 0;

+ kref_get(&dev->ref);
+
mutex_lock(&dev->lock);

if (dev->open)
goto unlock;

- kref_get(&dev->ref);
__module_get(dev->tr->owner);

if (!dev->mtd)
@@ -219,7 +212,6 @@ static int blktrans_open(struct block_device *bdev, fmode_t mode)
unlock:
dev->open++;
mutex_unlock(&dev->lock);
- blktrans_dev_put(dev);
return ret;

error_release:
@@ -227,7 +219,6 @@ static int blktrans_open(struct block_device *bdev, fmode_t mode)
dev->tr->release(dev);
error_put:
module_put(dev->tr->owner);
- kref_put(&dev->ref, blktrans_dev_release);
mutex_unlock(&dev->lock);
blktrans_dev_put(dev);
return ret;
@@ -235,14 +226,13 @@ static int blktrans_open(struct block_device *bdev, fmode_t mode)

static void blktrans_release(struct gendisk *disk, fmode_t mode)
{
- struct mtd_blktrans_dev *dev = blktrans_dev_get(disk);
+ struct mtd_blktrans_dev *dev = disk->private_data;

mutex_lock(&dev->lock);

if (--dev->open)
goto unlock;

- kref_put(&dev->ref, blktrans_dev_release);
module_put(dev->tr->owner);

if (dev->mtd) {
--
2.30.2