On 6/25/24 8:51 PM, Daniel Golle wrote: > +static int blk_call_notifier_add(struct device *dev) > +{ > + struct blk_device_list *new_blkdev; > + > + new_blkdev = kmalloc(sizeof(*new_blkdev), GFP_KERNEL); > + if (!new_blkdev) > + return -ENOMEM; > + > + new_blkdev->dev = dev; > + mutex_lock(&blk_notifier_lock); > + list_add_tail(&new_blkdev->list, &blk_devices); > + raw_notifier_call_chain(&blk_notifier_list, BLK_DEVICE_ADD, dev); > + mutex_unlock(&blk_notifier_lock); > + > + return 0; > +} Nit: redundant newline. > +device_initcall(blk_notifications_init); > diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h > index b2f1362c4681..8d22ba03e3e1 100644 > --- a/include/linux/blkdev.h > +++ b/include/linux/blkdev.h > @@ -1687,4 +1687,12 @@ static inline bool bdev_can_atomic_write(struct block_device *bdev) > > #define DEFINE_IO_COMP_BATCH(name) struct io_comp_batch name = { } > > + > +#ifdef CONFIG_BLOCK_NOTIFIERS #if defined(CONFIG_BLOCK_NOTIFIERS) > +#define BLK_DEVICE_ADD 1 > +#define BLK_DEVICE_REMOVE 2 > +void blk_register_notify(struct notifier_block *nb); > +void blk_unregister_notify(struct notifier_block *nb); > +#endif Surely these helpers should have a !CONFIG_BLOCK_NOTIFIERS failure case definition? Either that, or dummies. As it stands, any caller would need to check if it's enabled or not. -- Jens Axboe