1 files changed, 24 insertions, 63 deletions

diff --git a/drivers/mtd/ubi/scan.c b/drivers/mtd/ubi/scan.c
index 4dfbf27b0656..967bb4406df9 100644
--- a/drivers/mtd/ubi/scan.c
+++ b/drivers/mtd/ubi/scan.c
@@ -246,46 +246,21 @@ static int compare_lebs(struct ubi_device *ubi, const struct ubi_scan_leb *seb,
         struct ubi_vid_hdr *vh = NULL;
         unsigned long long sqnum2 = be64_to_cpu(vid_hdr->sqnum);
 
-        if (seb->sqnum == 0 && sqnum2 == 0) {
-                long long abs;
-                long long v1 = seb->leb_ver, v2 = be32_to_cpu(vid_hdr->leb_ver);
-
+        if (sqnum2 == seb->sqnum) {
                 /*
-                 * UBI constantly increases the logical eraseblock version
-                 * number and it can overflow. Thus, we have to bear in mind
-                 * that versions that are close to %0xFFFFFFFF are less then
-                 * versions that are close to %0.
-                 *
-                 * The UBI WL sub-system guarantees that the number of pending
-                 * tasks is not greater then %0x7FFFFFFF. So, if the difference
-                 * between any two versions is greater or equivalent to
-                 * %0x7FFFFFFF, there was an overflow and the logical
-                 * eraseblock with lower version is actually newer then the one
-                 * with higher version.
-                 *
-                 * FIXME: but this is anyway obsolete and will be removed at
-                 * some point.
+                 * This must be a really ancient UBI image which has been
+                 * created before sequence numbers support has been added. At
+                 * that times we used 32-bit LEB versions stored in logical
+                 * eraseblocks. That was before UBI got into mainline. We do not
+                 * support these images anymore. Well, those images will work
+                 * still work, but only if no unclean reboots happened.
                  */
-                dbg_bld("using old crappy leb_ver stuff");
-
-                if (v1 == v2) {
-                        ubi_err("PEB %d and PEB %d have the same version %lld",
-                                seb->pnum, pnum, v1);
-                        return -EINVAL;
-                }
+                ubi_err("unsupported on-flash UBI format\n");
+                return -EINVAL;
+        }
 
-                abs = v1 - v2;
-                if (abs < 0)
-                        abs = -abs;
-
-                if (abs < 0x7FFFFFFF)
-                        /* Non-overflow situation */
-                        second_is_newer = (v2 > v1);
-                else
-                        second_is_newer = (v2 < v1);
-        } else
-                /* Obviously the LEB with lower sequence counter is older */
-                second_is_newer = sqnum2 > seb->sqnum;
+        /* Obviously the LEB with lower sequence counter is older */
+        second_is_newer = !!(sqnum2 > seb->sqnum);
 
         /*
          * Now we know which copy is newer. If the copy flag of the PEB with
@@ -293,7 +268,7 @@ static int compare_lebs(struct ubi_device *ubi, const struct ubi_scan_leb *seb,
          * check data CRC. For the second PEB we already have the VID header,
          * for the first one - we'll need to re-read it from flash.
          *
-         * FIXME: this may be optimized so that we wouldn't read twice.
+         * Note: this may be optimized so that we wouldn't read twice.
          */
 
         if (second_is_newer) {
@@ -399,7 +374,6 @@ int ubi_scan_add_used(struct ubi_device *ubi, struct ubi_scan_info *si,
                       int bitflips)
 {
         int err, vol_id, lnum;
-        uint32_t leb_ver;
         unsigned long long sqnum;
         struct ubi_scan_volume *sv;
         struct ubi_scan_leb *seb;
@@ -408,10 +382,9 @@ int ubi_scan_add_used(struct ubi_device *ubi, struct ubi_scan_info *si,
         vol_id = be32_to_cpu(vid_hdr->vol_id);
         lnum = be32_to_cpu(vid_hdr->lnum);
         sqnum = be64_to_cpu(vid_hdr->sqnum);
-        leb_ver = be32_to_cpu(vid_hdr->leb_ver);
 
-        dbg_bld("PEB %d, LEB %d:%d, EC %d, sqnum %llu, ver %u, bitflips %d",
-                pnum, vol_id, lnum, ec, sqnum, leb_ver, bitflips);
+        dbg_bld("PEB %d, LEB %d:%d, EC %d, sqnum %llu, bitflips %d",
+                pnum, vol_id, lnum, ec, sqnum, bitflips);
 
         sv = add_volume(si, vol_id, pnum, vid_hdr);
         if (IS_ERR(sv) < 0)
@@ -444,25 +417,20 @@ int ubi_scan_add_used(struct ubi_device *ubi, struct ubi_scan_info *si,
                  */
 
                 dbg_bld("this LEB already exists: PEB %d, sqnum %llu, "
-                        "LEB ver %u, EC %d", seb->pnum, seb->sqnum,
-                        seb->leb_ver, seb->ec);
-
-                /*
-                 * Make sure that the logical eraseblocks have different
-                 * versions. Otherwise the image is bad.
-                 */
-                if (seb->leb_ver == leb_ver && leb_ver != 0) {
-                        ubi_err("two LEBs with same version %u", leb_ver);
-                        ubi_dbg_dump_seb(seb, 0);
-                        ubi_dbg_dump_vid_hdr(vid_hdr);
-                        return -EINVAL;
-                }
+                        "EC %d", seb->pnum, seb->sqnum, seb->ec);
 
                 /*
                  * Make sure that the logical eraseblocks have different
                  * sequence numbers. Otherwise the image is bad.
                  *
-                 * FIXME: remove 'sqnum != 0' check when leb_ver is removed.
+                 * However, if the sequence number is zero, we assume it must
+                 * be an ancient UBI image from the era when UBI did not have
+                 * sequence numbers. We still can attach these images, unless
+                 * there is a need to distinguish between old and new
+                 * eraseblocks, in which case we'll refuse the image in
+                 * 'compare_lebs()'. In other words, we attach old clean
+                 * images, but refuse attaching old images with duplicated
+                 * logical eraseblocks because there was an unclean reboot.
                  */
                 if (seb->sqnum == sqnum && sqnum != 0) {
                         ubi_err("two LEBs with same sequence number %llu",
@@ -502,7 +470,6 @@ int ubi_scan_add_used(struct ubi_device *ubi, struct ubi_scan_info *si,
                         seb->pnum = pnum;
                         seb->scrub = ((cmp_res & 2) || bitflips);
                         seb->sqnum = sqnum;
-                        seb->leb_ver = leb_ver;
 
                         if (sv->highest_lnum == lnum)
                                 sv->last_data_size =
@@ -539,7 +506,6 @@ int ubi_scan_add_used(struct ubi_device *ubi, struct ubi_scan_info *si,
         seb->lnum = lnum;
         seb->sqnum = sqnum;
         seb->scrub = bitflips;
-        seb->leb_ver = leb_ver;
 
         if (sv->highest_lnum <= lnum) {
                 sv->highest_lnum = lnum;
@@ -1263,11 +1229,6 @@ static int paranoid_check_si(struct ubi_device *ubi, struct ubi_scan_info *si)
                                 ubi_err("bad data_pad %d", sv->data_pad);
                                 goto bad_vid_hdr;
                         }
-
-                        if (seb->leb_ver != be32_to_cpu(vidh->leb_ver)) {
-                                ubi_err("bad leb_ver %u", seb->leb_ver);
-                                goto bad_vid_hdr;
-                        }
                 }
 
                 if (!last_seb)