[PATCH] libnvdimm, namespace: make min namespace size 4K

The arbitrary 4MB minimum namespace size turns out to be too large for some environments. Quoting Cheng-mean Liu: In the case of emulated NVDIMM devices in the VM environment, there are scenarios that NVDIMM device with much smaller sizes are desired, for example, we might use a single enumerated NVDIMM DAX device for representing each container layer, which in some cases could be just a few KBs size. PAGE_SIZE is the minimum where we can still support DAX of at least a single page. Cc: Matthew Wilcox <willy(a)infradead.org&gt; Reported-by: Cheng-mean Liu <soccerl(a)microsoft.com&gt; Signed-off-by: Dan Williams <dan.j.williams(a)intel.com&gt; --- include/uapi/linux/ndctl.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/uapi/linux/ndctl.h b/include/uapi/linux/ndctl.h index 30ef1236aafa..7e27070b9440 100644 --- a/include/uapi/linux/ndctl.h +++ b/include/uapi/linux/ndctl.h @@ -209,7 +209,7 @@ enum nd_driver_flags { }; enum { - ND_MIN_NAMESPACE_SIZE = 0x00400000, + ND_MIN_NAMESPACE_SIZE = PAGE_SIZE, }; enum ars_masks {