It is OK for s_first_meta_bg to be equal to the number of block group
descriptor blocks.  (It rarely happens, but it shouldn't cause any
problems.)
https://bugzilla.kernel.org/show_bug.cgi?id=194567
Fixes: 3a4b77cd47bb837b8557595ec7425f281f2ca1fe
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
        db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
                   EXT4_DESC_PER_BLOCK(sb);
        if (ext4_has_feature_meta_bg(sb)) {
-               if (le32_to_cpu(es->s_first_meta_bg) >= db_count) {
+               if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
                        ext4_msg(sb, KERN_WARNING,
                                 "first meta block group too large: %u "
                                 "(group descriptor block count %u)",