ubi: Deal with interrupted erasures in WL

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.

Cc: <stable@vger.kernel.org>
Fixes: dbb7d2a88d ("UBI: Add fastmap core")
Signed-off-by: Richard Weinberger <richard@nod.at>

diff --git a/drivers/mtd/ubi/wl.c b/drivers/mtd/ubi/wl.c
index 6351e8a..19206ad 100644 (file)
--- a/drivers/mtd/ubi/wl.c
+++ b/drivers/mtd/ubi/wl.c
@@ -644,7 +644,7 @@ static int wear_leveling_worker(struct ubi_device *ubi, struct ubi_work *wrk,
                                int shutdown)
 {
        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
@@ -783,6 +783,16 @@ static int wear_leveling_worker(struct ubi_device *ubi, struct ubi_work *wrk,
                               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(ubi, "error %d while reading VID header from PEB %d",
@@ -818,6 +828,7 @@ static int wear_leveling_worker(struct ubi_device *ubi, struct ubi_work *wrk,
                         * Target PEB had bit-flips or write error - torture it.
                         */
                        torture = 1;
+                       keep = 1;
                        goto out_not_moved;
                }
 
@@ -904,7 +915,7 @@ 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);
        if (dst_leb_clean) {
                wl_tree_add(e2, &ubi->free);
@@ -925,6 +936,12 @@ out_not_moved:
                        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;