UBI: nicify image sequence number handling

Move the image seq. number handling from I/O level to the scanning
lever, where it really belongs to. Move the @image_seq_set variable
to the @struct ubi_scan_info structure, which exists only during
scanning.

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

1 files changed, 14 insertions, 2 deletions

diff --git a/drivers/mtd/ubi/scan.c b/drivers/mtd/ubi/scan.c
index 72570ed7d33f..f60895ee0aeb 100644
--- a/drivers/mtd/ubi/scan.c
+++ b/drivers/mtd/ubi/scan.c
@@ -757,6 +757,8 @@ static int process_eb(struct ubi_device *ubi, struct ubi_scan_info *si,
 	si->is_empty = 0;
 
 	if (!ec_corr) {
+		int image_seq;
+
 		/* Make sure UBI version is OK */
 		if (ech->version != UBI_VERSION) {
 			ubi_err("this UBI version is %d, image version is %d",
@@ -778,6 +780,18 @@ static int process_eb(struct ubi_device *ubi, struct ubi_scan_info *si,
 			ubi_dbg_dump_ec_hdr(ech);
 			return -EINVAL;
 		}
+
+		image_seq = be32_to_cpu(ech->ec);
+		if (!si->image_seq_set) {
+			ubi->image_seq = image_seq;
+			si->image_seq_set = 1;
+		} else if (ubi->image_seq != image_seq) {
+			ubi_err("bad image sequence number %d in PEB %d, "
+				"expected %d", image_seq, pnum, ubi->image_seq);
+			ubi_dbg_dump_ec_hdr(ech);
+			return -EINVAL;
+		}
+
 	}
 
 	/* OK, we've done with the EC header, let's look at the VID header */
@@ -910,8 +924,6 @@ struct ubi_scan_info *ubi_scan(struct ubi_device *ubi)
 	if (si->is_empty)
 		ubi_msg("empty MTD device detected");
 
-	ubi->image_seq_set = 1;
-
 	/*
 	 * In case of unknown erase counter we use the mean erase counter
 	 * value.