mtd_blkdevs: simplify the refcounting in blktrans_{open, release}

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>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20210823073359.705281-9-hch@lst.de

diff --git a/drivers/mtd/mtd_blkdevs.c b/drivers/mtd/mtd_blkdevs.c
index e8eb4d8..12c1803 100644 (file)
--- 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 @@ error_release:
                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 @@ error_put:
 
 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) {