Re: [PATCH v4 09/18] mm, dax: enable filesystems to trigger dev_pagemap ->page_free callbacks

Looks fine, Reviewed-by: Christoph Hellwig ___ Linux-nvdimm mailing list Linux-nvdimm@lists.01.org https://lists.01.org/mailman/listinfo/linux-nvdimm

[PATCH v4 09/18] mm, dax: enable filesystems to trigger dev_pagemap ->page_free callbacks

In order to resolve collisions between filesystem operations and DMA to DAX mapped pages we need a callback when DMA completes. With a callback we can hold off filesystem operations while DMA is in-flight and then resume those operations when the last put_page() occurs on a DMA page. Recall that