From e20542f497522671fa121d7612442a2557bfa2ff Mon Sep 17 00:00:00 2001
From: Bhavesh Parekh <bparekh@nvidia.com>
Date: Wed, 30 Nov 2011 17:43:42 +0530
Subject: [PATCH 029/130] UBI: fix missing scrub when there is a bit-flip

commit e801e128b2200c40a0ec236cf2330b2586b6e05a upstream.

Under some cases, when scrubbing the PEB if we did not get the lock on
the PEB it fails to scrub. Add that PEB again to the scrub list

Artem: minor amendments.

Signed-off-by: Bhavesh Parekh <bparekh@nvidia.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
 drivers/mtd/ubi/eba.c |    6 ++++--
 drivers/mtd/ubi/ubi.h |    2 ++
 drivers/mtd/ubi/wl.c  |    5 ++++-
 3 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/drivers/mtd/ubi/eba.c b/drivers/mtd/ubi/eba.c
index fb7f19b..cd26da8 100644
--- a/drivers/mtd/ubi/eba.c
+++ b/drivers/mtd/ubi/eba.c
@@ -1028,12 +1028,14 @@ int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
 	 * 'ubi_wl_put_peb()' function on the @ubi->move_mutex. In turn, we are
 	 * holding @ubi->move_mutex and go sleep on the LEB lock. So, if the
 	 * LEB is already locked, we just do not move it and return
-	 * %MOVE_CANCEL_RACE, which means that UBI will re-try, but later.
+	 * %MOVE_RETRY. Note, we do not return %MOVE_CANCEL_RACE here because
+	 * we do not know the reasons of the contention - it may be just a
+	 * normal I/O on this LEB, so we want to re-try.
 	 */
 	err = leb_write_trylock(ubi, vol_id, lnum);
 	if (err) {
 		dbg_wl("contention on LEB %d:%d, cancel", vol_id, lnum);
-		return MOVE_CANCEL_RACE;
+		return MOVE_RETRY;
 	}
 
 	/*
diff --git a/drivers/mtd/ubi/ubi.h b/drivers/mtd/ubi/ubi.h
index dc64c76..d51d75d 100644
--- a/drivers/mtd/ubi/ubi.h
+++ b/drivers/mtd/ubi/ubi.h
@@ -120,6 +120,7 @@ enum {
  *                     PEB
  * MOVE_CANCEL_BITFLIPS: canceled because a bit-flip was detected in the
  *                       target PEB
+ * MOVE_RETRY: retry scrubbing the PEB
  */
 enum {
 	MOVE_CANCEL_RACE = 1,
@@ -127,6 +128,7 @@ enum {
 	MOVE_TARGET_RD_ERR,
 	MOVE_TARGET_WR_ERR,
 	MOVE_CANCEL_BITFLIPS,
+	MOVE_RETRY,
 };
 
 /**
diff --git a/drivers/mtd/ubi/wl.c b/drivers/mtd/ubi/wl.c
index 42c684c..277c429 100644
--- a/drivers/mtd/ubi/wl.c
+++ b/drivers/mtd/ubi/wl.c
@@ -795,7 +795,10 @@ static int wear_leveling_worker(struct ubi_device *ubi, struct ubi_work *wrk,
 			protect = 1;
 			goto out_not_moved;
 		}
-
+		if (err == MOVE_RETRY) {
+			scrubbing = 1;
+			goto out_not_moved;
+		}
 		if (err == MOVE_CANCEL_BITFLIPS || err == MOVE_TARGET_WR_ERR ||
 		    err == MOVE_TARGET_RD_ERR) {
 			/*
-- 
1.7.7.4

