diff -u -r btrfs-progs-v4.20.1/utils.c btrfs-progs-v4.20.1-issue162/utils.c --- btrfs-progs-v4.20.1/utils.c 2019-01-23 12:56:53.000000000 +0000 +++ btrfs-progs-v4.20.1-issue162/utils.c 2019-02-02 22:56:06.320029310 +0000 @@ -2079,7 +2079,7 @@ while ((ent = getmntent(mnttab))) { len = strlen(ent->mnt_dir); if (strncmp(ent->mnt_dir, path, len) == 0 && - (path[len] == '/' || path[len] == '\0')) { + (len == 1 || path[len] == '/' || path[len] == '\0')) { /* match found and use the latest match */ if (longest_matchlen <= len) { free(longest_match);