[PATCH 2/2] UBI: fastmap: Pass to_be_tortured when reusing old fastmap PEBs

[Zhihao Cheng]

In ubi_update_fastmap(), when no fresh PEB is available to replace an
old fastmap PEB, the old PEB is reused by erasing it synchronously
via ubi_sync_erase() with the torture flag hardcoded to zero.

However, old_fm->to_be_tortured[] may be non-zero: it is set during
fastmap scanning when ubi_io_read_data()/ubi_io_read_ec_hdr() reports
UBI_IO_BITFLIPS, meaning the PEB showed signs of bit decay and should
be tortured to verify it is still reliable.

When the old PEB is instead returned to the WL sub-system via
ubi_wl_put_fm_peb(), the to_be_tortured flag is honored. The
synchronous reuse path is inconsistent: it silently skips the torture
test for PEBs that exhibited bit-flips.

Fix it by passing &old_fm->to_be_tortured[i] to ubi_sync_erase().

Fixes: dbb7d2a88d2a ("UBI: Add fastmap core")
Signed-off-by: Zhihao Cheng <chengzhihao1 at huawei.com>
---
 drivers/mtd/ubi/fastmap.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/mtd/ubi/fastmap.c b/drivers/mtd/ubi/fastmap.c
index 98cc698d9c34..3f9fb7c181ff 100644
--- a/drivers/mtd/ubi/fastmap.c
+++ b/drivers/mtd/ubi/fastmap.c
@@ -1488,7 +1488,7 @@ static void return_fm_pebs(struct ubi_device *ubi,
  */
 int ubi_update_fastmap(struct ubi_device *ubi)
 {
-	int ret, i, j, torture = 0;
+	int ret, i, j;
 	struct ubi_fastmap_layout *new_fm, *old_fm;
 	struct ubi_wl_entry *tmp_e;
 
@@ -1526,7 +1526,8 @@ int ubi_update_fastmap(struct ubi_device *ubi)
 
 		if (!tmp_e) {
 			if (old_fm && old_fm->e[i]) {
-				ret = ubi_sync_erase(ubi, old_fm->e[i], &torture);
+				ret = ubi_sync_erase(ubi, old_fm->e[i],
+						    &old_fm->to_be_tortured[i]);
 				if (ret < 0) {
 					ubi_err(ubi, "could not erase old fastmap PEB");
 
@@ -1578,7 +1579,8 @@ int ubi_update_fastmap(struct ubi_device *ubi)
 	if (old_fm) {
 		/* no fresh anchor PEB was found, reuse the old one */
 		if (!tmp_e) {
-			ret = ubi_sync_erase(ubi, old_fm->e[0], &torture);
+			ret = ubi_sync_erase(ubi, old_fm->e[0],
+					     &old_fm->to_be_tortured[0]);
 			if (ret < 0) {
 				ubi_err(ubi, "could not erase old anchor PEB");
 
-- 
2.52.0