FAILED: patch "[PATCH] libnvdimm, btt: fix btt_rw_page not returning errors" failed to apply to 4.4-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

>From c13c43d54f2c6a3be1c675766778ac1ad8dfbfcc Mon Sep 17 00:00:00 2001
From: Vishal Verma <vishal.l.verma@intel.com>
Date: Thu, 29 Jun 2017 16:59:11 -0600
Subject: [PATCH] libnvdimm, btt: fix btt_rw_page not returning errors

btt_rw_page was not propagating errors frm btt_do_bvec, resulting in any
IO errors via the rw_page path going unnoticed. the pmem driver recently
fixed this in e10624f pmem: fail io-requests to known bad blocks
but same problem in BTT went neglected.

Fixes: 5212e11fde4d ("nd_btt: atomic sector updates")
Cc: <stable@vger.kernel.org>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

diff --git a/drivers/nvdimm/btt.c b/drivers/nvdimm/btt.c
index 7ca11df80ae8..4e56e720288d 100644
--- a/drivers/nvdimm/btt.c
+++ b/drivers/nvdimm/btt.c
@@ -1248,10 +1248,13 @@ static int btt_rw_page(struct block_device *bdev, sector_t sector,
 		struct page *page, bool is_write)
 {
 	struct btt *btt = bdev->bd_disk->private_data;
+	int rc;
 
-	btt_do_bvec(btt, NULL, page, PAGE_SIZE, 0, is_write, sector);
-	page_endio(page, is_write, 0);
-	return 0;
+	rc = btt_do_bvec(btt, NULL, page, PAGE_SIZE, 0, is_write, sector);
+	if (rc == 0)
+		page_endio(page, is_write, 0);
+
+	return rc;
 }