> +DEFINE_MUTEX(devmap_lock);
static?
> +#if IS_ENABLED(CONFIG_FS_DAX)
> +static void generic_dax_pagefree(struct page *page, void *data)
> +{
> +}
> +
> +struct dax_device *fs_dax_claim_bdev(struct block_device *bdev, void *owner)
> +{
> + struct dax_device *dax_dev;
> + struct dev_pagem
Towards solving DAX-DMA vs truncate arrange for filesystems to set up a
page-idle callback when they mount a dax_device.
No functional changes are expected as this only registers a nop handler
for the ->page_free() event for device-mapped pages.
Cc: "Jérôme Glisse"
Cc: Michal Hocko
Signed-off-b