From: Vishal Verma <vishal.l.verma@intel.com>
Date: Wed, 30 Aug 2017 19:35:58 -0600
Subject: libnvdimm, btt: fix a missed NVDIMM_IO_ATOMIC case in the write path
Patch-mainline: v4.14-rc1
Git-commit: 1db1f3cea1d8886c686832d4618b346ae16c03c8
References: FATE#323731

The IO context conversion for rw_bytes missed a case in the BTT write
path (btt_map_write) which should've been marked as atomic.

In reality this should not cause a problem, because map writes are to
small for nsio_rw_bytes to attempt error clearing, but it should be
fixed for posterity.

Add a might_sleep() in the non-atomic section of nsio_rw_bytes so that
things like the nfit unit tests, which don't actually sleep, can catch
bugs like this.

Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Johannes Thumshirn <jthumshirn@suse.de>
---
 drivers/nvdimm/btt.c   |    3 ++-
 drivers/nvdimm/claim.c |    1 +
 2 files changed, 3 insertions(+), 1 deletion(-)

--- a/drivers/nvdimm/btt.c
+++ b/drivers/nvdimm/btt.c
@@ -1156,7 +1156,8 @@ static int btt_write_pg(struct btt *btt,
 		if (ret)
 			goto out_map;
 
-		ret = btt_map_write(arena, premap, new_postmap, 0, 0, 0);
+		ret = btt_map_write(arena, premap, new_postmap, 0, 0,
+			NVDIMM_IO_ATOMIC);
 		if (ret)
 			goto out_map;
 
--- a/drivers/nvdimm/claim.c
+++ b/drivers/nvdimm/claim.c
@@ -292,6 +292,7 @@ static int nsio_rw_bytes(struct nd_names
 				&& !(flags & NVDIMM_IO_ATOMIC)) {
 			long cleared;
 
+			might_sleep();
 			cleared = nvdimm_clear_poison(&ndns->dev,
 					nsio->res.start + offset, size);
 			if (cleared < size)