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file-restore-daemon/disk: add LVM (thin) support

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Parses JSON output from 'pvs' and 'lvs' LVM utils and does two passes:
one to scan for thinpools and create a device node for their
metadata_lv, and a second to load all LVs, thin-provisioned or not.

Should support every LV-type that LVM supports, as we only parse LVM
tools and use 'vgscan --mknodes' to create device nodes for us.

Produces a two-layer BucketComponent hierarchy with VGs followed by LVs,
PVs are mapped to their respective disk node.

Signed-off-by: Stefan Reiter <s.reiter@proxmox.com>
Reviewed-By: Fabian Grünbichler <f.gruenbichler@proxmox.com>
This commit is contained in:
Stefan Reiter 2021-06-30 17:57:59 +02:00 committed by Thomas Lamprecht
parent 6c4f762c49
commit cb590dbc07
1 changed files with 189 additions and 0 deletions
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189
src/bin/proxmox_restore_daemon/disk.rs
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@ -62,6 +62,14 @@ struct ZFSBucketData {
size: Option<u64>,
}
#[derive(Clone)]
struct LVMBucketData {
vg_name: String,
lv_name: String,
mountpoint: Option<PathBuf>,
size: u64,
}
/// A "Bucket" represents a mapping found on a disk, e.g. a partition, a zfs dataset or an LV. A
/// uniquely identifying path to a file then consists of four components:
/// "/disk/bucket/component/path"
@ -77,6 +85,7 @@ enum Bucket {
Partition(PartitionBucketData),
RawFs(PartitionBucketData),
ZPool(ZFSBucketData),
LVM(LVMBucketData),
}
impl Bucket {
@ -102,6 +111,13 @@ impl Bucket {
false
}
}
Bucket::LVM(data) => {
if let (Some(ref vg), Some(ref lv)) = (comp.get(0), comp.get(1)) {
ty == "lvm" && vg.as_ref() == &data.vg_name && lv.as_ref() == &data.lv_name
} else {
false
}
}
})
}
@ -110,6 +126,7 @@ impl Bucket {
Bucket::Partition(_) => "part",
Bucket::RawFs(_) => "raw",
Bucket::ZPool(_) => "zpool",
Bucket::LVM(_) => "lvm",
}
}
@ -127,6 +144,13 @@ impl Bucket {
Bucket::Partition(data) => data.number.to_string(),
Bucket::RawFs(_) => "raw".to_owned(),
Bucket::ZPool(data) => data.name.clone(),
Bucket::LVM(data) => {
if idx == 0 {
data.vg_name.clone()
} else {
data.lv_name.clone()
}
}
})
}
@ -135,6 +159,7 @@ impl Bucket {
"part" => 1,
"raw" => 0,
"zpool" => 1,
"lvm" => 2,
_ => bail!("invalid bucket type for component depth: {}", type_string),
})
}
@ -143,6 +168,13 @@ impl Bucket {
match self {
Bucket::Partition(data) | Bucket::RawFs(data) => Some(data.size),
Bucket::ZPool(data) => data.size,
Bucket::LVM(data) => {
if idx == 1 {
Some(data.size)
} else {
None
}
}
}
}
}
@ -264,6 +296,21 @@ impl Filesystems {
data.size = Some(size);
}
let mp = PathBuf::from(mntpath);
data.mountpoint = Some(mp.clone());
Ok(mp)
}
Bucket::LVM(data) => {
if let Some(mp) = &data.mountpoint {
return Ok(mp.clone());
}
let mntpath = format!("/mnt/lvm/{}/{}", &data.vg_name, &data.lv_name);
create_dir_all(&mntpath)?;
let mapper_path = format!("/dev/mapper/{}-{}", &data.vg_name, &data.lv_name);
self.try_mount(&mapper_path, &mntpath)?;
let mp = PathBuf::from(mntpath);
data.mountpoint = Some(mp.clone());
Ok(mp)
@ -444,12 +491,154 @@ impl DiskState {
}
}
Self::scan_lvm(&mut disk_map, &drive_info)?;
Ok(Self {
filesystems,
disk_map,
})
}
/// scan for LVM volumes and create device nodes for them to later mount on demand
fn scan_lvm(
disk_map: &mut HashMap<String, Vec<Bucket>>,
drive_info: &HashMap<String, String>,
) -> Result<(), Error> {
// first get mapping between devices and vgs
let mut pv_map: HashMap<String, Vec<String>> = HashMap::new();
let mut cmd = Command::new("/sbin/pvs");
cmd.args(["-o", "pv_name,vg_name", "--reportformat", "json"].iter());
let result = run_command(cmd, None).unwrap();
let result: serde_json::Value = serde_json::from_str(&result)?;
if let Some(result) = result["report"][0]["pv"].as_array() {
for pv in result {
let vg_name = pv["vg_name"].as_str().unwrap();
if vg_name.is_empty() {
continue;
}
let pv_name = pv["pv_name"].as_str().unwrap();
// remove '/dev/' part
let pv_name = &pv_name[pv_name.rfind('/').map(|i| i + 1).unwrap_or(0)..];
if let Some(fidx) = drive_info.get(pv_name) {
info!("LVM: found VG '{}' on '{}' ({})", vg_name, pv_name, fidx);
match pv_map.get_mut(vg_name) {
Some(list) => list.push(fidx.to_owned()),
None => {
pv_map.insert(vg_name.to_owned(), vec![fidx.to_owned()]);
}
}
}
}
}
let mknodes = || {
let mut cmd = Command::new("/sbin/vgscan");
cmd.arg("--mknodes");
if let Err(err) = run_command(cmd, None) {
warn!("LVM: 'vgscan --mknodes' failed: {}", err);
}
};
// then scan for LVs and assign their buckets to the correct disks
let mut cmd = Command::new("/sbin/lvs");
cmd.args(
[
"-o",
"vg_name,lv_name,lv_size,metadata_lv",
"--units",
"B",
"--reportformat",
"json",
]
.iter(),
);
let result = run_command(cmd, None).unwrap();
let result: serde_json::Value = serde_json::from_str(&result)?;
let mut thinpools = Vec::new();
if let Some(result) = result["report"][0]["lv"].as_array() {
// first, look for thin-pools
for lv in result {
let metadata = lv["metadata_lv"].as_str().unwrap_or_default();
if !metadata.is_empty() {
// this is a thin-pool, activate the metadata LV
let vg_name = lv["vg_name"].as_str().unwrap();
let metadata = metadata.trim_matches(&['[', ']'][..]);
info!("LVM: attempting to activate thinpool '{}'", metadata);
let mut cmd = Command::new("/sbin/lvchange");
cmd.args(["-ay", "-y", &format!("{}/{}", vg_name, metadata)].iter());
if let Err(err) = run_command(cmd, None) {
// not critical, will simply mean its children can't be loaded
warn!("LVM: activating thinpool failed: {}", err);
} else {
thinpools.push((vg_name, metadata));
}
}
}
// now give the metadata LVs a device node
mknodes();
// cannot leave the metadata LV active, otherwise child-LVs won't activate
for (vg_name, metadata) in thinpools {
let mut cmd = Command::new("/sbin/lvchange");
cmd.args(["-an", "-y", &format!("{}/{}", vg_name, metadata)].iter());
let _ = run_command(cmd, None);
}
for lv in result {
let lv_name = lv["lv_name"].as_str().unwrap();
let vg_name = lv["vg_name"].as_str().unwrap();
let metadata = lv["metadata_lv"].as_str().unwrap_or_default();
if lv_name.is_empty() || vg_name.is_empty() || !metadata.is_empty() {
continue;
}
let lv_size = lv["lv_size"].as_str().unwrap();
// lv_size is in bytes with a capital 'B' at the end
let lv_size = lv_size[..lv_size.len() - 1].parse::<u64>().unwrap_or(0);
let bucket = Bucket::LVM(LVMBucketData {
vg_name: vg_name.to_owned(),
lv_name: lv_name.to_owned(),
size: lv_size,
mountpoint: None,
});
// activate the LV so 'vgscan' can create a node later - this may fail, and if it
// does, we ignore it and continue
let mut cmd = Command::new("/sbin/lvchange");
cmd.args(["-ay", &format!("{}/{}", vg_name, lv_name)].iter());
if let Err(err) = run_command(cmd, None) {
warn!(
"LVM: LV '{}' on '{}' ({}B) failed to activate: {}",
lv_name, vg_name, lv_size, err
);
continue;
}
info!(
"LVM: found LV '{}' on '{}' ({}B)",
lv_name, vg_name, lv_size
);
if let Some(drives) = pv_map.get(vg_name) {
for fidx in drives {
match disk_map.get_mut(fidx) {
Some(v) => v.push(bucket.clone()),
None => {
disk_map.insert(fidx.to_owned(), vec![bucket.clone()]);
}
}
}
}
}
// now that we've imported and activated all LV's, we let vgscan create the dev nodes
mknodes();
}
Ok(())
}
/// Given a path like "/drive-scsi0.img.fidx/part/0/etc/passwd", this will mount the first
/// partition of 'drive-scsi0' on-demand (i.e. if not already mounted) and return a path
/// pointing to the requested file locally, e.g. "/mnt/vda1/etc/passwd", which can be used to