ubi: fastmap: Detect EBA mismatches on-the-fly

Now we have the machinery to detect EBA mismatches on-the-fly
by comparing the in-memory volume ID and LEB number with the found
VID header.
This helps to detect malfunction of Fastmap.

Signed-off-by: Richard Weinberger <richard@nod.at>

diff --git a/drivers/mtd/ubi/eba.c b/drivers/mtd/ubi/eba.c
index 1ceab20..edb1c83 100644 (file)
--- a/drivers/mtd/ubi/eba.c
+++ b/drivers/mtd/ubi/eba.c
@@ -513,6 +513,7 @@ static int check_mapping(struct ubi_device *ubi, struct ubi_volume *vol, int lnu
 {
        int err;
        struct ubi_vid_io_buf *vidb;
+       struct ubi_vid_hdr *vid_hdr;
 
        if (!ubi->fast_attach)
                return 0;
@@ -552,6 +553,22 @@ static int check_mapping(struct ubi_device *ubi, struct ubi_volume *vol, int lnu
                        *pnum, err);
 
                goto out_free;
+       } else {
+               int found_vol_id, found_lnum;
+
+               ubi_assert(err == 0 || err == UBI_IO_BITFLIPS);
+
+               vid_hdr = ubi_get_vid_hdr(vidb);
+               found_vol_id = be32_to_cpu(vid_hdr->vol_id);
+               found_lnum = be32_to_cpu(vid_hdr->lnum);
+
+               if (found_lnum != lnum || found_vol_id != vol->vol_id) {
+                       ubi_err(ubi, "EBA mismatch! PEB %i is LEB %i:%i instead of LEB %i:%i",
+                               *pnum, found_vol_id, found_lnum, vol->vol_id, lnum);
+                       ubi_ro_mode(ubi);
+                       err = -EINVAL;
+                       goto out_free;
+               }
        }
 
        set_bit(lnum, vol->checkmap);