[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.chu@xxxxxxxxxx>
---
 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