4.16-stable review patch. If anyone has any objections, please let me know.
------------------ From: Dave Jiang <[email protected]> commit ef8423022324cf79bd1b41d8707c766461e7e555 upstream. 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: <[email protected]> Fixes: b6fb293f2497 ("mm: Define MAP_SYNC and VM_SYNC flags") Signed-off-by: Dave Jiang <[email protected]> Reviewed-by: Dan Williams <[email protected]> Signed-off-by: Dan Williams <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- drivers/dax/device.c | 2 ++ 1 file changed, 2 insertions(+) --- 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" @@ -534,6 +535,7 @@ static const struct file_operations dax_ .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)
