The patch below does not apply to the 4.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From fa7d2e639cd90442d868dfc6ca1d4cc9d8bf206e Mon Sep 17 00:00:00 2001

From: Dan Williams dan.j.williams@intel.com Date: Thu, 24 Jan 2019 17:33:06 -0800 Subject: [PATCH] libnvdimm/pmem: Honor force_raw for legacy pmem regions

For recovery, where non-dax access is needed to a given physical address range, and testing, allow the 'force_raw' attribute to override the default establishment of a dev_pagemap.

Otherwise without this capability it is possible to end up with a namespace that can not be activated due to corrupted info-block, and one that can not be repaired due to a section collision.

Cc: stable@vger.kernel.org Fixes: 004f1afbe199 ("libnvdimm, pmem: direct map legacy pmem by default") Signed-off-by: Dan Williams dan.j.williams@intel.com

diff --git a/drivers/nvdimm/namespace_devs.c b/drivers/nvdimm/namespace_devs.c index 4b077555ac70..33a3b23b3db7 100644 --- a/drivers/nvdimm/namespace_devs.c +++ b/drivers/nvdimm/namespace_devs.c @@ -138,6 +138,7 @@ bool nd_is_uuid_unique(struct device *dev, u8 *uuid) bool pmem_should_map_pages(struct device *dev) { struct nd_region *nd_region = to_nd_region(dev->parent); + struct nd_namespace_common *ndns = to_ndns(dev); struct nd_namespace_io *nsio;

if (!IS_ENABLED(CONFIG_ZONE_DEVICE)) @@ -149,6 +150,9 @@ bool pmem_should_map_pages(struct device *dev) if (is_nd_pfn(dev) || is_nd_btt(dev)) return false;

+ if (ndns->force_raw) + return false; + nsio = to_nd_namespace_io(dev); if (region_intersects(nsio->res.start, resource_size(&nsio->res), IORESOURCE_SYSTEM_RAM,