if (bytelock) {
        /*
         * Lock a byte of the file: if we don't get the lock, some other process is holding it,
         * we're done. The file may be zero-length, and that's OK, the underlying call supports
         * locking past the end-of-file.
         */
        if (__wt_file_lock(session, conn->lock_fh, true) != 0)
            WT_ERR_MSG(session, EBUSY,
              "WiredTiger database is already being managed by "
              "another process");

/*
 * If the size of the lock file is non-zero, we created it (or
 * won a locking race with the thread that created it, it
 * doesn't matter).
 *
 * Write something into the file, zero-length files make me
 * nervous.
 *
 * The test against the expected length is sheer paranoia (the
 * length should be 0 or correct), but it shouldn't hurt.
 */
#define WT_SINGLETHREAD_STRING "WiredTiger lock file\n"
        WT_ERR(__wt_filesize(session, conn->lock_fh, &size));
        if ((size_t)size != strlen(WT_SINGLETHREAD_STRING))
            WT_ERR(__wt_write(session, conn->lock_fh, (wt_off_t)0, strlen(WT_SINGLETHREAD_STRING),
              WT_SINGLETHREAD_STRING));
    }

    /* We own the lock file, optionally create the WiredTiger file. */
    ret = __wt_open(
      session, WT_WIREDTIGER, WT_FS_OPEN_FILE_TYPE_REGULAR, is_create ? WT_FS_OPEN_CREATE : 0, &fh);