[pbs-devel] [PATCH proxmox-backup v2 1/2] fix #5439: allow to reuse existing datastore
Fabian Grünbichler
f.gruenbichler at proxmox.com
Wed Jul 10 15:28:21 CEST 2024
On June 12, 2024 3:22 pm, Gabriel Goller wrote:
> Disallow creating datastores in non-empty directories. Allow adding
> existing datastores via a 'reuse-datastore' checkmark. This only checks
> if all the necessary directories (.chunks + subdirectories and .lock)
> are existing and have the correct permissions, then opens the
> datastore.
>
> Signed-off-by: Gabriel Goller <g.goller at proxmox.com>
> ---
>
> v2, thanks @Fabian:
> - also check on frontend for root
> - forbid datastore creation if dir not empty
> - add reuse-datastore option
> - verify chunkstore directories permissions and owners
>
> pbs-datastore/src/chunk_store.rs | 49 ++++++++++++++++++++++++++++-
> src/api2/config/datastore.rs | 54 +++++++++++++++++++++++++-------
> src/api2/node/disks/directory.rs | 1 +
> src/api2/node/disks/zfs.rs | 1 +
> 4 files changed, 93 insertions(+), 12 deletions(-)
>
> diff --git a/pbs-datastore/src/chunk_store.rs b/pbs-datastore/src/chunk_store.rs
> index 9f6289c9..077bc316 100644
> --- a/pbs-datastore/src/chunk_store.rs
> +++ b/pbs-datastore/src/chunk_store.rs
> @@ -164,7 +164,7 @@ impl ChunkStore {
> /// Note that this must be used with care, as it's dangerous to create two instances on the
> /// same base path, as closing the underlying ProcessLocker drops all locks from this process
> /// on the lockfile (even if separate FDs)
given this ^
> - pub(crate) fn open<P: Into<PathBuf>>(
> + pub fn open<P: Into<PathBuf>>(
wouldn't it make more sense to split out the path checks and call them
both in open and in verify_chunkstore below
> name: &str,
> base: P,
> sync_level: DatastoreFSyncLevel,
> @@ -563,6 +563,53 @@ impl ChunkStore {
> // unwrap: only `None` in unit tests
> ProcessLocker::try_exclusive_lock(self.locker.clone().unwrap())
> }
> +
> + /// Checks permissions and owner of passed path.
> + fn check_permissions<T: AsRef<Path>>(path: T, file_mode: u32) -> Result<(), Error> {
> + match nix::sys::stat::stat(path.as_ref()) {
> + Ok(stat) => {
> + if stat.st_uid != u32::from(pbs_config::backup_user()?.uid)
> + || stat.st_gid != u32::from(pbs_config::backup_group()?.gid)
> + || stat.st_mode & 0o700 != file_mode
> + {
> + bail!(
> + "unable to open existing chunk store path {:?} - permissions or owner not correct",
> + path.as_ref(),
> + );
> + }
> + }
> + Err(err) => {
> + bail!(
> + "unable to open existing chunk store path {:?} - {err}",
> + path.as_ref(),
> + );
> + }
> + }
> + Ok(())
> + }
> +
> + /// Verify vital files in datastore. Checks the owner and permissions of: the chunkstore, it's
> + /// subdirectories and the lock file.
> + pub fn verify_chunkstore<T: AsRef<Path>>(path: T) -> Result<(), Error> {
> + // Check datastore root path perm/owner
> + ChunkStore::check_permissions(path.as_ref(), 0o700)?;
> +
> + let chunk_dir = Self::chunk_dir(path.as_ref());
> + // Check datastore .chunks path perm/owner
> + ChunkStore::check_permissions(&chunk_dir, 0o700)?;
> +
> + // Check all .chunks subdirectories
> + for i in 0..64 * 1024 {
> + let mut l1path = chunk_dir.clone();
> + l1path.push(format!("{:04x}", i));
> + ChunkStore::check_permissions(&l1path, 0o700)?;
> + }
> +
> + // Check .lock file
> + let lockfile_path = Self::lockfile_path(path.as_ref());
> + ChunkStore::check_permissions(lockfile_path, 0o600)?;
> + Ok(())
> + }
> }
>
> #[test]
> diff --git a/src/api2/config/datastore.rs b/src/api2/config/datastore.rs
> index 6b742acb..f1e80b2d 100644
> --- a/src/api2/config/datastore.rs
> +++ b/src/api2/config/datastore.rs
> @@ -1,7 +1,7 @@
> use std::path::PathBuf;
>
> use ::serde::{Deserialize, Serialize};
> -use anyhow::Error;
> +use anyhow::{bail, Error};
> use hex::FromHex;
> use serde_json::Value;
>
> @@ -70,23 +70,48 @@ pub(crate) fn do_create_datastore(
> _lock: BackupLockGuard,
> mut config: SectionConfigData,
> datastore: DataStoreConfig,
> + reuse_datastore: bool,
> worker: Option<&dyn WorkerTaskContext>,
> ) -> Result<(), Error> {
> let path: PathBuf = datastore.path.clone().into();
>
> + if path.parent().is_none() {
> + bail!("cannot create datastore in root path");
> + }
> +
> + let datastore_empty = std::fs::read_dir(path.clone())?.all(|dir| {
doesn't this read_dir fail if `path` doesn't exist yet? prior to this
change, creating a datastore would also create the datastore dir itself
(and any parents!).
> + dir.map_or(false, |file| {
> + file.file_name().to_str().map_or(false, |name| {
> + (name.starts_with('.')
> + && !(name == ".chunks" || name == ".lock" || name == ".gc-status"))
> + || name.starts_with("lost+found")
I think the last check there could be == as well?
the indentation here is kinda whacky.. maybe it would be enough to
consider `.chunks` to mark a dir as non-empty?
> + })
> + })
>+ });
should we do this always? or restructure the ifs below and just do it
for the non-reusing create path?
> +
> let tuning: DatastoreTuning = serde_json::from_value(
> DatastoreTuning::API_SCHEMA
> .parse_property_string(datastore.tuning.as_deref().unwrap_or(""))?,
> )?;
> - let backup_user = pbs_config::backup_user()?;
> - let _store = ChunkStore::create(
> - &datastore.name,
> - path,
> - backup_user.uid,
> - backup_user.gid,
> - worker,
> - tuning.sync_level.unwrap_or_default(),
> - )?;
> +
> + if !datastore_empty && !reuse_datastore {
> + bail!("Directory is not empty!");
> + } else if !datastore_empty && reuse_datastore {
> + ChunkStore::verify_chunkstore(&path)?;
> +
> + let _store =
> + ChunkStore::open(&datastore.name, path, tuning.sync_level.unwrap_or_default())?;
(continued from first comment above) and leave out this call here?
> + } else {
> + let backup_user = pbs_config::backup_user()?;
> + let _store = ChunkStore::create(
> + &datastore.name,
> + path,
> + backup_user.uid,
> + backup_user.gid,
> + worker,
> + tuning.sync_level.unwrap_or_default(),
> + )?;
> + }
>
> config.set_data(&datastore.name, "datastore", &datastore)?;
>
> @@ -103,6 +128,12 @@ pub(crate) fn do_create_datastore(
> type: DataStoreConfig,
> flatten: true,
> },
> + "reuse-datastore": {
> + type: Boolean,
> + optional: true,
> + default: false,
> + description: "Re-use existing datastore directory."
> + }
> },
> },
> access: {
> @@ -112,6 +143,7 @@ pub(crate) fn do_create_datastore(
> /// Create new datastore config.
> pub fn create_datastore(
> config: DataStoreConfig,
> + reuse_datastore: bool,
> rpcenv: &mut dyn RpcEnvironment,
> ) -> Result<String, Error> {
> let lock = pbs_config::datastore::lock_config()?;
> @@ -156,7 +188,7 @@ pub fn create_datastore(
> auth_id.to_string(),
> to_stdout,
> move |worker| {
> - do_create_datastore(lock, section_config, config, Some(&worker))?;
> + do_create_datastore(lock, section_config, config, reuse_datastore, Some(&worker))?;
>
> if let Some(prune_job_config) = prune_job_config {
> do_create_prune_job(prune_job_config, Some(&worker))
> diff --git a/src/api2/node/disks/directory.rs b/src/api2/node/disks/directory.rs
> index 9f1112a9..25cfe784 100644
> --- a/src/api2/node/disks/directory.rs
> +++ b/src/api2/node/disks/directory.rs
> @@ -217,6 +217,7 @@ pub fn create_datastore_disk(
> lock,
> config,
> datastore,
> + false,
> Some(&worker),
> )?;
> }
> diff --git a/src/api2/node/disks/zfs.rs b/src/api2/node/disks/zfs.rs
> index 673dc1bf..ad2129fc 100644
> --- a/src/api2/node/disks/zfs.rs
> +++ b/src/api2/node/disks/zfs.rs
> @@ -323,6 +323,7 @@ pub fn create_zpool(
> lock,
> config,
> datastore,
> + false,
> Some(&worker),
> )?;
> }
> --
> 2.43.0
>
>
>
> _______________________________________________
> pbs-devel mailing list
> pbs-devel at lists.proxmox.com
> https://lists.proxmox.com/cgi-bin/mailman/listinfo/pbs-devel
>
>
>
More information about the pbs-devel
mailing list