4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Dan Williams <dan.j.williams@xxxxxxxxx>
commit fa7d2e639cd90442d868dfc6ca1d4cc9d8bf206e upstream.
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@xxxxxxxxxxxxxxx>
Fixes: 004f1afbe199 ("libnvdimm, pmem: direct map legacy pmem by default")
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/nvdimm/namespace_devs.c | 4 ++++
1 file changed, 4 insertions(+)
--- a/drivers/nvdimm/namespace_devs.c
+++ b/drivers/nvdimm/namespace_devs.c
@@ -138,6 +138,7 @@ bool nd_is_uuid_unique(struct device *de
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
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,
