[PATCH] blkdev: make struct block_device_operations.devnode() take a const *

From: Greg Kroah-Hartman
Date: Wed Nov 09 2022 - 09:49:03 EST


The devnode() callback in struct block_device_operations should not be
modifying the device that is passed into it, so mark it as a const * and
propagate the function signature changes out into the one subsystem that
actually uses this callback.

Cc: linux-block@xxxxxxxxxxxxxxx
Cc: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---

Jens, I have some dependent kobject/driver core changes that require
this change in the works. Can I take this through the driver core tree
for 6.2-rc1?

drivers/block/pktcdvd.c | 2 +-
include/linux/blkdev.h | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
index 4cea3b08087e..8dc15be95962 100644
--- a/drivers/block/pktcdvd.c
+++ b/drivers/block/pktcdvd.c
@@ -2632,7 +2632,7 @@ static unsigned int pkt_check_events(struct gendisk *disk,
return attached_disk->fops->check_events(attached_disk, clearing);
}

-static char *pkt_devnode(struct gendisk *disk, umode_t *mode)
+static char *pkt_devnode(const struct gendisk *disk, umode_t *mode)
{
return kasprintf(GFP_KERNEL, "pktcdvd/%s", disk->disk_name);
}
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 50e358a19d98..2a455793462b 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1413,7 +1413,7 @@ struct block_device_operations {
void (*swap_slot_free_notify) (struct block_device *, unsigned long);
int (*report_zones)(struct gendisk *, sector_t sector,
unsigned int nr_zones, report_zones_cb cb, void *data);
- char *(*devnode)(struct gendisk *disk, umode_t *mode);
+ char *(*devnode)(const struct gendisk *disk, umode_t *mode);
/* returns the length of the identifier or a negative errno: */
int (*get_unique_id)(struct gendisk *disk, u8 id[16],
enum blk_unique_id id_type);
--
2.38.1