device-dax: allow MAP_SYNC to succeed
MAP_SYNC is a nop for device-dax. Allow MAP_SYNC to succeed on device-dax
to eliminate special casing between device-dax and fs-dax as to when the
flag can be specified. Device-dax users already implicitly assume that they do
not need to call fsync(), and this enables them to explicitly check for this
capability.
Cc: <stable@vger.kernel.org>
Fixes: b6fb293f2497 ("mm: Define MAP_SYNC and VM_SYNC flags")
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
diff --git a/drivers/dax/device.c b/drivers/dax/device.c
index be86064..aff2c15 100644
--- a/drivers/dax/device.c
+++ b/drivers/dax/device.c
@@ -19,6 +19,7 @@
#include <linux/dax.h>
#include <linux/fs.h>
#include <linux/mm.h>
+#include <linux/mman.h>
#include "dax-private.h"
#include "dax.h"
@@ -540,6 +541,7 @@ static const struct file_operations dax_fops = {
.release = dax_release,
.get_unmapped_area = dax_get_unmapped_area,
.mmap = dax_mmap,
+ .mmap_supported_flags = MAP_SYNC,
};
static void dev_dax_release(struct device *dev)