MaartenBaert

Manually fixing bit flips in BTRFS

Somehow my BTRFS file system became corrupted by what appears to be a single bit flip in a metadata field. Rather than copying all the data and reformatting the file system, which would have required another disk at least as large as the original, I decided to try to fix this manually, which appears to have worked. I've documented the procedure I've used here, in case I need it again or someone else runs into a similar issue and finds it useful.

The first thing you should do is run btrfs check. For me this produced the following output:

Opening filesystem to check...
Checking filesystem on /dev/nvme0n1p1
UUID: ec7afe1c-8478-450a-82fc-d17b32d8ca3d

MaartenBaert

import ctypes
import glob
import mmap
import operator
import os.path
import time

import numpy
import matplotlib.pyplot as plt

MaartenBaert

QProgressDialog dialog("Parameter sweep ...", "Cancel", 0, (int) sweep_values.size(), this);
dialog.setWindowTitle(MainWindow::WINDOW_CAPTION);
dialog.setWindowModality(Qt::WindowModal);
dialog.setMinimumDuration(0);
dialog.setValue(0);
std::atomic<bool> worker_canceled(false), worker_stopped(false);
std::exception_ptr worker_exception;
std::thread worker_thread([&]() {
	try {
		for(size_t i = 0; i < sweep_values.size(); ++i) {

MaartenBaert

# Maintainer: Schala <schalaalexiazeal "at" gmail {dot} com>
# Contributor: calegria <calegria+al "at" gmail {dot} com>

pkgbase=mingw-w64-harfbuzz
pkgname=(mingw-w64-harfbuzz mingw-w64-harfbuzz-icu)
pkgver=1.5.1
pkgrel=1
pkgdesc="OpenType text shaping engine (mingw-w64)"
arch=(any)
url="http://www.freedesktop.org/wiki/Software/HarfBuzz"

MaartenBaert

from pylab import *

def segment_intersects_rectangle(x1, y1, x2, y2, cx, cy, w, h):
	return (fabs(x1 + x2 - 2.0 * cx) < fabs(x1 - x2) + w and
	        fabs(y1 + y2 - 2.0 * cy) < fabs(y1 - y2) + h and
	        2.0 * fabs((x1 - cx) * (y1 - y2) - (y1 - cy) * (x1 - x2)) < w * fabs(y1 - y2) + h * fabs(x1 - x2))

def test_intersect(plot_line, plot_rect):
	for line in plot_line:
		(x1, x2) = line.get_xdata()

MaartenBaert

#!/bin/bash

# IMPORTANT: READ THIS BEFORE RUNNING THIS SCRIPT!
# This script only works when the system is configured correctly. Do these things first:
#
# Step 1:
# - If you have an ~/.asoundrc file, rename it to ~/.asoundrc-default. If you don't have one, create an empty file named ~/.asoundrc-default.
# - Create ~/.asoundrc-jack with the contents found here: https://gist.github.com/MaartenBaert/3630a1863969ba344704
# The script will create a symlink from .asoundrc to .asoundrc-jack when started, and from .asoundrc to .asoundrc-default when stopped.
#

MaartenBaert

# Some of this may look redundant, but this was carefully written to
# work around various bugs in alsa-plugins, so don't mess with it :).

# override default
pcm.!default {
	type plug
	slave {
		pcm "rjack"
	}
}