pmem: add proper fencing to pmem_rw_page()

Orabug: 22913653

pmem_rw_page() needs to call wmb_pmem() on writes to make sure that the
newly written data is durable.  This flow was added to pmem_rw_bytes()
and pmem_make_request() with this commit:

commit 61031952f4c8 ("arch, x86: pmem api for ensuring durability of
	persistent memory updates")

...the pmem_rw_page() path was missed.

Cc: <stable@vger.kernel.org>
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
(cherry picked from commit ba8fe0f85e15d047686caf8a42463b592c63c98c)
Signed-off-by: Dan Duval <dan.duval@oracle.com>

diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index 0dff13290d549427d24edf95bea30d26502bb308..fffeccd5af6bec866b6524da41f81f930d945dca 100644 (file)
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -92,6 +92,8 @@ static int pmem_rw_page(struct block_device *bdev, sector_t sector,
        struct pmem_device *pmem = bdev->bd_disk->private_data;
 
        pmem_do_bvec(pmem, page, PAGE_CACHE_SIZE, 0, rw, sector);
+       if (rw & WRITE)
+               wmb_pmem();
        page_endio(page, rw & WRITE, 0);
 
        return 0;