From: Filip Schauer <f.schauer@proxmox.com>
To: pbs-devel@lists.proxmox.com
Cc: Wolfgang Bumiller <w.bumiller@proxmox.com>
Subject: [pbs-devel] [PATCH backup v2 1/2] fix #5946: disks: wipe: ensure GPT header backup is wiped
Date: Tue, 11 Feb 2025 17:26:38 +0100 [thread overview]
Message-ID: <20250211162639.141541-2-f.schauer@proxmox.com> (raw)
In-Reply-To: <20250211162639.141541-1-f.schauer@proxmox.com>
When wiping a block device with a GUID partition table, the header
backup might get left behind at the end of the disk. This commit also
wipes the last 4096 bytes of the disk, making sure that a GPT header
backup is erased, even from disks with 4k sector sizes.
Co-authored-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
Signed-off-by: Filip Schauer <f.schauer@proxmox.com>
---
src/tools/disks/mod.rs | 49 +++++++++++++++++++++++-------------------
1 file changed, 27 insertions(+), 22 deletions(-)
diff --git a/src/tools/disks/mod.rs b/src/tools/disks/mod.rs
index 571446db..ad9df0b5 100644
--- a/src/tools/disks/mod.rs
+++ b/src/tools/disks/mod.rs
@@ -4,11 +4,11 @@ use std::collections::{HashMap, HashSet};
use std::ffi::{OsStr, OsString};
use std::io;
use std::os::unix::ffi::{OsStrExt, OsStringExt};
-use std::os::unix::fs::MetadataExt;
+use std::os::unix::fs::{FileExt, MetadataExt, OpenOptionsExt};
use std::path::{Path, PathBuf};
use std::sync::{Arc, LazyLock};
-use anyhow::{bail, format_err, Error};
+use anyhow::{bail, format_err, Context as _, Error};
use libc::dev_t;
use once_cell::sync::OnceCell;
@@ -1145,7 +1145,7 @@ pub fn inititialize_gpt_disk(disk: &Disk, uuid: Option<&str>) -> Result<(), Erro
Ok(())
}
-/// Wipes all labels and the first 200 MiB of a disk/partition (or the whole if it is smaller).
+/// Wipes all labels, the first 200 MiB and the last 4096 bytes of a disk/partition.
/// If called with a partition, also sets the partition type to 0x83 'Linux filesystem'.
pub fn wipe_blockdev(disk: &Disk) -> Result<(), Error> {
let disk_path = match disk.device_path() {
@@ -1176,25 +1176,7 @@ pub fn wipe_blockdev(disk: &Disk) -> Result<(), Error> {
let wipefs_output = proxmox_sys::command::run_command(wipefs_command, None)?;
info!("wipefs output: {wipefs_output}");
- let size = disk.size().map(|size| size / 1024 / 1024)?;
- let count = size.min(200);
-
- let mut dd_command = std::process::Command::new("dd");
- let mut of_path = OsString::from("of=");
- of_path.push(disk_path);
- let mut count_str = OsString::from("count=");
- count_str.push(count.to_string());
- let args = [
- "if=/dev/zero".into(),
- of_path,
- "bs=1M".into(),
- "conv=fdatasync".into(),
- count_str,
- ];
- dd_command.args(args);
-
- let dd_output = proxmox_sys::command::run_command(dd_command, None)?;
- info!("dd output: {dd_output}");
+ zero_disk_start_and_end(disk)?;
if is_partition {
// set the partition type to 0x83 'Linux filesystem'
@@ -1204,6 +1186,29 @@ pub fn wipe_blockdev(disk: &Disk) -> Result<(), Error> {
Ok(())
}
+pub fn zero_disk_start_and_end(disk: &Disk) -> Result<(), Error> {
+ let disk_path = match disk.device_path() {
+ Some(path) => path,
+ None => bail!("disk {:?} has no node in /dev", disk.syspath()),
+ };
+
+ let disk_size = disk.size()?;
+ let file = std::fs::OpenOptions::new()
+ .write(true)
+ .custom_flags(libc::O_CLOEXEC | libc::O_DSYNC)
+ .open(disk_path)
+ .with_context(|| "failed to open device {disk_path:?} for writing")?;
+ let write_size = disk_size.min(200 * 1024 * 1024);
+ let zeroes = proxmox_io::boxed::zeroed(write_size as usize);
+ file.write_all_at(&zeroes, 0)
+ .with_context(|| "failed to wipe start of device {disk_path:?}")?;
+ if disk_size > write_size {
+ file.write_all_at(&zeroes[0..4096], disk_size - 4096)
+ .with_context(|| "failed to wipe end of device {disk_path:?}")?;
+ }
+ Ok(())
+}
+
pub fn change_parttype(part_disk: &Disk, part_type: &str) -> Result<(), Error> {
let part_path = match part_disk.device_path() {
Some(path) => path,
--
2.39.5
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next prev parent reply other threads:[~2025-02-11 16:27 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-02-11 16:26 [pbs-devel] [PATCH backup v2 0/2] " Filip Schauer
2025-02-11 16:26 ` Filip Schauer [this message]
2025-02-11 18:39 ` [pbs-devel] [PATCH backup v2 1/2] " Thomas Lamprecht
2025-02-12 11:01 ` Filip Schauer
2025-02-11 16:26 ` [pbs-devel] [PATCH backup v2 2/2] disks: wipe: only zero out the first 1 MiB Filip Schauer
2025-02-11 18:42 ` Thomas Lamprecht
2025-02-12 10:24 ` Filip Schauer
2025-02-12 13:44 ` Thomas Lamprecht
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