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>

4 files changed, 18 insertions, 16 deletions

diff --git a/drivers/mtd/ubi/io.c b/drivers/mtd/ubi/io.c
index b58714011091..1ea14218de02 100644
--- a/drivers/mtd/ubi/io.c
+++ b/drivers/mtd/ubi/io.c
@@ -563,16 +563,15 @@ int ubi_io_mark_bad(const struct ubi_device *ubi, int pnum)
  * This function returns zero if the erase counter header is OK, and %1 if
  * not.
  */
-static int validate_ec_hdr(struct ubi_device *ubi,
+static int validate_ec_hdr(const struct ubi_device *ubi,
                            const struct ubi_ec_hdr *ec_hdr)
 {
         long long ec;
-        int vid_hdr_offset, leb_start, image_seq;
+        int vid_hdr_offset, leb_start;
 
         ec = be64_to_cpu(ec_hdr->ec);
         vid_hdr_offset = be32_to_cpu(ec_hdr->vid_hdr_offset);
         leb_start = be32_to_cpu(ec_hdr->data_offset);
-        image_seq = be32_to_cpu(ec_hdr->image_seq);
 
         if (ec_hdr->version != UBI_VERSION) {
                 ubi_err("node with incompatible UBI version found: "
@@ -598,15 +597,6 @@ static int validate_ec_hdr(struct ubi_device *ubi,
                 goto bad;
         }
 
-        if (!ubi->image_seq_set) {
-                ubi->image_seq = image_seq;
-                ubi->image_seq_set = 1;
-        } else if (ubi->image_seq != image_seq) {
-                ubi_err("bad image sequence number %d, expected %d",
-                        image_seq, ubi->image_seq);
-                goto bad;
-        }
-
         return 0;
 
 bad:
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.
diff --git a/drivers/mtd/ubi/scan.h b/drivers/mtd/ubi/scan.h
index 61df208e2f20..1017cf12def5 100644
--- a/drivers/mtd/ubi/scan.h
+++ b/drivers/mtd/ubi/scan.h
@@ -102,6 +102,7 @@ struct ubi_scan_volume {
  * @mean_ec: mean erase counter value
  * @ec_sum: a temporary variable used when calculating @mean_ec
  * @ec_count: a temporary variable used when calculating @mean_ec
+ * @image_seq_set: indicates @ubi->image_seq is known
  *
  * This data structure contains the result of scanning and may be used by other
  * UBI sub-systems to build final UBI data structures, further error-recovery
@@ -124,6 +125,7 @@ struct ubi_scan_info {
         int mean_ec;
         uint64_t ec_sum;
         int ec_count;
+        int image_seq_set;
 };
 
 struct ubi_device;
diff --git a/drivers/mtd/ubi/ubi.h b/drivers/mtd/ubi/ubi.h
index bb372c4222b7..64604e8809ec 100644
--- a/drivers/mtd/ubi/ubi.h
+++ b/drivers/mtd/ubi/ubi.h
@@ -302,7 +302,6 @@ struct ubi_wl_entry;
  *                @vol->ref_count, @vol->mapping and @vol->eba_tbl.
  * @ref_count: count of references on the UBI device
  * @image_seq: image sequence number recorded on EC headers
- * @image_seq_set: indicates @image_seq is known
  *
  * @rsvd_pebs: count of reserved physical eraseblocks
  * @avail_pebs: count of available physical eraseblocks
@@ -393,7 +392,6 @@ struct ubi_device {
         spinlock_t volumes_lock;
         int ref_count;
         int image_seq;
-        int image_seq_set;
 
         int rsvd_pebs;
         int avail_pebs;