This looks reasonable to me. A few more comments below.
> This patch replaces and consolidates patch 2 [1] and 4 [2] from the v9
> series [3] for "dax: fix dma vs truncate/hole-punch".
Can you repost the whole series? Otherwise things might get a little
too confusing.
> WARN_ON(IS_ENABLED(CONFIG_ARCH_HAS_PMEM_API));
> + return 0;
> } else if (pfn_t_devmap(pfn)) {
> + struct dev_pagemap *pgmap;
This should probably become something like:
bool supported = false;
...
if (IS_ENABLED(CONFIG_FS_DAX_LIMITED) && pfn_t_special(pfn)) {
...
supported = true;
} else if (pfn_t_devmap(pfn)) {
pgmap = get_dev_pagemap(pfn_t_to_pfn(pfn), NULL);
if (pgmap && pgmap->type == MEMORY_DEVICE_FS_DAX)
supported = true;
put_dev_pagemap(pgmap);
}
if (!supported) {
pr_debug("VFS (%s): error: dax support not enabled\n",
sb->s_id);
return -EOPNOTSUPP;
}
return 0;
> + select DEV_PAGEMAP_OPS if (ZONE_DEVICE && !FS_DAX_LIMITED)
Btw, what was the reason again we couldn't get rid of FS_DAX_LIMITED?
> +void generic_dax_pagefree(struct page *page, void *data)
> +{
> + wake_up_var(&page->_refcount);
> +}
> +EXPORT_SYMBOL_GPL(generic_dax_pagefree);
Why is this here and exported instead of static in drivers/nvdimm/pmem.c?
