[PATCH v3 7/7] pmem: fix pmem_do_write() avoid writing to 'np' page

[Jane Chu]

Since poisoned page is marked as not-present, the first of the
two back-to-back write_pmem() calls can only be made when there
is no poison in the range, otherwise kernel Oops.

Signed-off-by: Jane Chu <jane....@oracle.com>
---
 drivers/nvdimm/pmem.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index dd2db4905c85..6e395014da5e 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -187,10 +187,15 @@ static blk_status_t pmem_do_write(struct pmem_device 
*pmem,
         * after clear poison.
         */
        flush_dcache_page(page);
-       write_pmem(pmem_addr, page, page_off, len);
-       if (unlikely(bad_pmem)) {
-               rc = pmem_clear_poison(pmem, pmem_off, len);
+       if (!bad_pmem) {
                write_pmem(pmem_addr, page, page_off, len);
+       } else {
+               rc = pmem_clear_poison(pmem, pmem_off, len);
+               if (rc == BLK_STS_OK)
+                       write_pmem(pmem_addr, page, page_off, len);
+               else
+                       pr_warn("%s: failed to clear poison\n",
+                               __func__);
        }
 
        return rc;
-- 
2.18.4