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path: root/drivers/mtd/ubi/attach.c
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Diffstat (limited to 'drivers/mtd/ubi/attach.c')
-rw-r--r--drivers/mtd/ubi/attach.c28
1 files changed, 24 insertions, 4 deletions
diff --git a/drivers/mtd/ubi/attach.c b/drivers/mtd/ubi/attach.c
index bd6fc528b10a..903becd31410 100644
--- a/drivers/mtd/ubi/attach.c
+++ b/drivers/mtd/ubi/attach.c
@@ -856,13 +856,15 @@ static bool vol_ignored(int vol_id)
* @ubi: UBI device description object
* @ai: attaching information
* @pnum: the physical eraseblock number
+ * @fast: true if we're scanning for a Fastmap
*
* This function reads UBI headers of PEB @pnum, checks them, and adds
* information about this PEB to the corresponding list or RB-tree in the
* "attaching info" structure. Returns zero if the physical eraseblock was
* successfully handled and a negative error code in case of failure.
*/
-static int scan_peb(struct ubi_device *ubi, struct ubi_attach_info *ai, int pnum)
+static int scan_peb(struct ubi_device *ubi, struct ubi_attach_info *ai,
+ int pnum, bool fast)
{
long long ec;
int err, bitflips = 0, vol_id = -1, ec_err = 0;
@@ -980,6 +982,20 @@ static int scan_peb(struct ubi_device *ubi, struct ubi_attach_info *ai, int pnum
*/
ai->maybe_bad_peb_count += 1;
case UBI_IO_BAD_HDR:
+ /*
+ * If we're facing a bad VID header we have to drop *all*
+ * Fastmap data structures we find. The most recent Fastmap
+ * could be bad and therefore there is a chance that we attach
+ * from an old one. On a fine MTD stack a PEB must not render
+ * bad all of a sudden, but the reality is different.
+ * So, let's be paranoid and help finding the root cause by
+ * falling back to scanning mode instead of attaching with a
+ * bad EBA table and cause data corruption which is hard to
+ * analyze.
+ */
+ if (fast)
+ ai->force_full_scan = 1;
+
if (ec_err)
/*
* Both headers are corrupted. There is a possibility
@@ -1293,7 +1309,7 @@ static int scan_all(struct ubi_device *ubi, struct ubi_attach_info *ai,
cond_resched();
dbg_gen("process PEB %d", pnum);
- err = scan_peb(ubi, ai, pnum);
+ err = scan_peb(ubi, ai, pnum, false);
if (err < 0)
goto out_vidh;
}
@@ -1407,7 +1423,7 @@ static int scan_fast(struct ubi_device *ubi, struct ubi_attach_info **ai)
cond_resched();
dbg_gen("process PEB %d", pnum);
- err = scan_peb(ubi, scan_ai, pnum);
+ err = scan_peb(ubi, scan_ai, pnum, true);
if (err < 0)
goto out_vidh;
}
@@ -1415,7 +1431,11 @@ static int scan_fast(struct ubi_device *ubi, struct ubi_attach_info **ai)
ubi_free_vid_hdr(ubi, vidh);
kfree(ech);
- err = ubi_scan_fastmap(ubi, *ai, scan_ai);
+ if (scan_ai->force_full_scan)
+ err = UBI_NO_FASTMAP;
+ else
+ err = ubi_scan_fastmap(ubi, *ai, scan_ai);
+
if (err) {
/*
* Didn't attach via fastmap, do a full scan but reuse what