[PATCH v2] nvdimm/btt: fix variable 'rc' set but not used

[Qian Cai]

drivers/nvdimm/btt.c: In function 'btt_read_pg':
drivers/nvdimm/btt.c:1264:8: warning: variable 'rc' set but not used
[-Wunused-but-set-variable]
    int rc;
        ^~

Add a ratelimited message in case a storm of errors is encountered.

Fixes: d9b83c756953 ("libnvdimm, btt: rework error clearing")
Signed-off-by: Qian Cai <cai@xxxxxx>
---

v2: include the block address that is returning an error per Dan.

 drivers/nvdimm/btt.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/nvdimm/btt.c b/drivers/nvdimm/btt.c
index 3e9f45aec8d1..10313be78221 100644
--- a/drivers/nvdimm/btt.c
+++ b/drivers/nvdimm/btt.c
@@ -1266,6 +1266,12 @@ static int btt_read_pg(struct btt *btt, struct bio_integrity_payload *bip,
 			/* Media error - set the e_flag */
 			rc = btt_map_write(arena, premap, postmap, 0, 1,
 				NVDIMM_IO_ATOMIC);
+
+			if (rc)
+				dev_warn_ratelimited(to_dev(arena),
+					"Error persistently tracking bad blocks at %#x\n",
+					premap);
+
 			goto out_rtt;
 		}
 
-- 
1.8.3.1