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: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220215094514.3828912-5-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Christoph Hellwig 2022-02-15 10:45:13 +01:00 committed by Jens Axboe
parent 6dab421bfe
commit 185ed423d1
1 changed files with 7 additions and 42 deletions

View File

@ -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);
}
}
idr_remove(&mspro_block_disk_idr, disk_id);
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,
.getgeo = mspro_block_bd_getgeo,
.owner = THIS_MODULE
.owner = THIS_MODULE,
.getgeo = mspro_block_bd_getgeo,
.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);
}