[PATCH 3.16 089/306] ubi: Deal with interrupted erasures in WL

Ben Hutchings
2017-02-15T23:17:34Z

From: Richard Weinberger <richard@nod.at>

commit 2365418879e9abf12ea9def7f9f3caf0dfa7ffb0 upstream.

When Fastmap is used we can face here an -EBADMSG
since Fastmap cannot know about unmaps.
If the erasure was interrupted the PEB may show ECC
errors and UBI would go to ro-mode as it assumes
that the PEB was check during attach time, which is
not the case with Fastmap.

Fixes: dbb7d2a88d ("UBI: Add fastmap core")
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
drivers/mtd/ubi/wl.c | 21 +++++++++++++++++++--
1 file changed, 19 insertions(+), 2 deletions(-)

--- a/drivers/mtd/ubi/wl.c
+++ b/drivers/mtd/ubi/wl.c
@@ -1000,7 +1000,7 @@ static int wear_leveling_worker(struct u
int cancel)
{
int err, scrubbing = 0, torture = 0, protect = 0, erroneous = 0;
- int vol_id = -1, lnum = -1;
+ int erase = 0, keep = 0, vol_id = -1, lnum = -1;
#ifdef CONFIG_MTD_UBI_FASTMAP
int anchor = wrk->anchor;
#endif
@@ -1134,6 +1134,16 @@ static int wear_leveling_worker(struct u
e1->pnum);
scrubbing = 1;
goto out_not_moved;
+ } else if (ubi->fast_attach && err == UBI_IO_BAD_HDR_EBADMSG) {
+ /*
+ * While a full scan would detect interrupted erasures
+ * at attach time we can face them here when attached from
+ * Fastmap.
+ */
+ dbg_wl("PEB %d has ECC errors, maybe from an interrupted erasure",
+ e1->pnum);
+ erase = 1;
+ goto out_not_moved;
}

ubi_err("error %d while reading VID header from PEB %d",
@@ -1167,6 +1177,7 @@ static int wear_leveling_worker(struct u
* Target PEB had bit-flips or write error - torture it.
*/
torture = 1;
+ keep = 1;
goto out_not_moved;
}

@@ -1252,7 +1263,7 @@ out_not_moved:
ubi->erroneous_peb_count += 1;
} else if (scrubbing)
wl_tree_add(e1, &ubi->scrub);
- else
+ else if (keep)
wl_tree_add(e1, &ubi->used);
ubi_assert(!ubi->move_to_put);
ubi->move_from = ubi->move_to = NULL;
@@ -1264,6 +1275,12 @@ out_not_moved:
if (err)
goto out_ro;

+ if (erase) {
+ err = do_sync_erase(ubi, e1, vol_id, lnum, 1);
+ if (err)
+ goto out_ro;
+ }
+
mutex_unlock(&ubi->move_mutex);
return 0;