Commit 185ed423 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
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memstick/mspro_block: simplify refcounting 



Implement the ->free_disk method to free the msb_data structure only once
the last gendisk reference goes away instead of keeping a local
refcount.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220215094514.3828912-5-hch@lst.de


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 6dab421b

drivers/memstick/core/mspro_block.c

+7 −42
Original line number Diff line number Diff line
@@ -133,7 +133,6 @@ struct mspro_devinfo { 


struct mspro_block_data {

	struct memstick_dev   *card;

	unsigned int          usage_count;

	unsigned int          caps;

	struct gendisk        *disk;

	struct request_queue  *queue;
@@ -178,48 +177,16 @@ static int mspro_block_complete_req(struct memstick_dev *card, int error); 


/*** Block device ***/



static int mspro_block_bd_open(struct block_device *bdev, fmode_t mode)

{

	struct gendisk *disk = bdev->bd_disk;

	struct mspro_block_data *msb = disk->private_data;

	int rc = -ENXIO;



	mutex_lock(&mspro_block_disk_lock);



	if (msb && msb->card)

		msb->usage_count++;



	mutex_unlock(&mspro_block_disk_lock);



	return rc;

}





static void mspro_block_disk_release(struct gendisk *disk)

static void mspro_block_bd_free_disk(struct gendisk *disk)

{

	struct mspro_block_data *msb = disk->private_data;

	int disk_id = MINOR(disk_devt(disk)) >> MSPRO_BLOCK_PART_SHIFT;



	mutex_lock(&mspro_block_disk_lock);



	if (msb) {

		if (msb->usage_count)

			msb->usage_count--;



		if (!msb->usage_count) {

			kfree(msb);

			disk->private_data = NULL;

	idr_remove(&mspro_block_disk_idr, disk_id);

			put_disk(disk);

		}

	}



	mutex_unlock(&mspro_block_disk_lock);

}



static void mspro_block_bd_release(struct gendisk *disk, fmode_t mode)

{

	mspro_block_disk_release(disk);

	kfree(msb);

}



static int mspro_block_bd_getgeo(struct block_device *bdev,
@@ -235,10 +202,9 @@ static int mspro_block_bd_getgeo(struct block_device *bdev, 
}



static const struct block_device_operations ms_block_bdops = {

	.open    = mspro_block_bd_open,

	.release = mspro_block_bd_release,

	.owner		= THIS_MODULE,

	.getgeo		= mspro_block_bd_getgeo,

	.owner   = THIS_MODULE

	.free_disk	= mspro_block_bd_free_disk,

};



/*** Information ***/
@@ -1221,7 +1187,6 @@ static int mspro_block_init_disk(struct memstick_dev *card) 
	msb->disk->first_minor = disk_id << MSPRO_BLOCK_PART_SHIFT;

	msb->disk->minors = 1 << MSPRO_BLOCK_PART_SHIFT;

	msb->disk->fops = &ms_block_bdops;

	msb->usage_count = 1;

	msb->disk->private_data = msb;



	sprintf(msb->disk->disk_name, "mspblk%d", disk_id);
@@ -1339,7 +1304,7 @@ static void mspro_block_remove(struct memstick_dev *card) 
	mspro_block_data_clear(msb);

	mutex_unlock(&mspro_block_disk_lock);



	mspro_block_disk_release(msb->disk);

	put_disk(msb->disk);

	memstick_set_drvdata(card, NULL);

}