UBI: check if we are in RO mode in the erase routine

'do_sync_erase()' has to check whether we are in R/O mode before
erasing the PEB. This patch adds the check and while on it, adds an
assertion which validates the 'pnum' argument, as well as removes
a check which is always true because it has already been done
few lines before.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>

1 files changed, 7 insertions, 1 deletions

diff --git a/drivers/mtd/ubi/io.c b/drivers/mtd/ubi/io.c
index eededf94f5a6..e347cc4388ed 100644
--- a/drivers/mtd/ubi/io.c
+++ b/drivers/mtd/ubi/io.c
@@ -344,6 +344,12 @@ static int do_sync_erase(struct ubi_device *ubi, int pnum)
         wait_queue_head_t wq;
 
         dbg_io("erase PEB %d", pnum);
+        ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
+
+        if (ubi->ro_mode) {
+                ubi_err("read-only mode");
+                return -EROFS;
+        }
 
 retry:
         init_waitqueue_head(&wq);
@@ -390,7 +396,7 @@ retry:
         if (err)
                 return err;
 
-        if (ubi_dbg_is_erase_failure() && !err) {
+        if (ubi_dbg_is_erase_failure()) {
                 dbg_err("cannot erase PEB %d (emulated)", pnum);
                 return -EIO;
         }