]> git.proxmox.com Git - proxmox-backup.git/blobdiff - src/backup/datastore.rs
typo fixes all over the place
[proxmox-backup.git] / src / backup / datastore.rs
index b24ae41294df19ba461fecd1d3688fc9a6de4190..28dda7e7888fffec87cbbed4c3d18431c31d7676 100644 (file)
@@ -1,22 +1,34 @@
-use failure::*;
-
-use std::io;
-use std::path::{PathBuf, Path};
-use std::collections::HashMap;
+use std::collections::{HashSet, HashMap};
+use std::io::{self, Write};
+use std::path::{Path, PathBuf};
+use std::sync::{Arc, Mutex};
+use std::convert::TryFrom;
+use std::str::FromStr;
+use std::time::Duration;
+use std::fs::File;
+
+use anyhow::{bail, format_err, Error};
 use lazy_static::lazy_static;
-use std::sync::{Mutex, Arc};
 
-use crate::tools;
-use crate::config::datastore;
-use super::chunk_store::*;
-use super::fixed_index::*;
-use super::dynamic_index::*;
+use proxmox::tools::fs::{replace_file, file_read_optional_string, CreateOptions, open_file_locked};
+
+use super::backup_info::{BackupGroup, BackupDir};
+use super::chunk_store::ChunkStore;
+use super::dynamic_index::{DynamicIndexReader, DynamicIndexWriter};
+use super::fixed_index::{FixedIndexReader, FixedIndexWriter};
+use super::manifest::{MANIFEST_BLOB_NAME, MANIFEST_LOCK_NAME, CLIENT_LOG_BLOB_NAME, BackupManifest};
 use super::index::*;
-use super::backup_info::*;
-use crate::server::WorkerTask;
+use super::{DataBlob, ArchiveType, archive_type};
+use crate::config::datastore::{self, DataStoreConfig};
+use crate::task::TaskState;
+use crate::tools;
+use crate::tools::format::HumanByte;
+use crate::tools::fs::{lock_dir_noblock, DirLockGuard};
+use crate::api2::types::{Authid, GarbageCollectionStatus};
+use crate::server::UPID;
 
-lazy_static!{
-    static ref DATASTORE_MAP: Mutex<HashMap<String, Arc<DataStore>>> =  Mutex::new(HashMap::new());
+lazy_static! {
+    static ref DATASTORE_MAP: Mutex<HashMap<String, Arc<DataStore>>> = Mutex::new(HashMap::new());
 }
 
 /// Datastore Management
@@ -25,30 +37,31 @@ lazy_static!{
 /// management interface for backup.
 pub struct DataStore {
     chunk_store: Arc<ChunkStore>,
-    gc_mutex: Mutex<bool>,
+    gc_mutex: Mutex<()>,
     last_gc_status: Mutex<GarbageCollectionStatus>,
+    verify_new: bool,
 }
 
 impl DataStore {
 
     pub fn lookup_datastore(name: &str) -> Result<Arc<DataStore>, Error> {
 
-        let config = datastore::config()?;
-        let (_, store_config) = config.sections.get(name)
-            .ok_or(format_err!("no such datastore '{}'", name))?;
-
-        let path = store_config["path"].as_str().unwrap();
+        let (config, _digest) = datastore::config()?;
+        let config: datastore::DataStoreConfig = config.lookup("datastore", name)?;
+        let path = PathBuf::from(&config.path);
 
         let mut map = DATASTORE_MAP.lock().unwrap();
 
         if let Some(datastore) = map.get(name) {
             // Compare Config - if changed, create new Datastore object!
-            if datastore.chunk_store.base == PathBuf::from(path) {
+            if datastore.chunk_store.base == path &&
+                datastore.verify_new == config.verify_new.unwrap_or(false)
+            {
                 return Ok(datastore.clone());
             }
         }
 
-        let datastore = DataStore::open(name)?;
+        let datastore = DataStore::open_with_path(name, &path, config)?;
 
         let datastore = Arc::new(datastore);
         map.insert(name.to_string(), datastore.clone());
@@ -56,33 +69,39 @@ impl DataStore {
         Ok(datastore)
     }
 
-    pub fn open(store_name: &str) -> Result<Self, Error> {
-
-        let config = datastore::config()?;
-        let (_, store_config) = config.sections.get(store_name)
-            .ok_or(format_err!("no such datastore '{}'", store_name))?;
-
-        let path = store_config["path"].as_str().unwrap();
-
+    fn open_with_path(store_name: &str, path: &Path, config: DataStoreConfig) -> Result<Self, Error> {
         let chunk_store = ChunkStore::open(store_name, path)?;
 
-        let gc_status = GarbageCollectionStatus::default();
+        let mut gc_status_path = chunk_store.base_path();
+        gc_status_path.push(".gc-status");
+
+        let gc_status = if let Some(state) = file_read_optional_string(gc_status_path)? {
+            match serde_json::from_str(&state) {
+                Ok(state) => state,
+                Err(err) => {
+                    eprintln!("error reading gc-status: {}", err);
+                    GarbageCollectionStatus::default()
+                }
+            }
+        } else {
+            GarbageCollectionStatus::default()
+        };
 
         Ok(Self {
             chunk_store: Arc::new(chunk_store),
-            gc_mutex: Mutex::new(false),
+            gc_mutex: Mutex::new(()),
             last_gc_status: Mutex::new(gc_status),
+            verify_new: config.verify_new.unwrap_or(false),
         })
     }
 
     pub fn get_chunk_iterator(
         &self,
-        print_percentage: bool,
     ) -> Result<
-        impl Iterator<Item = Result<tools::fs::ReadDirEntry, Error>>,
+        impl Iterator<Item = (Result<tools::fs::ReadDirEntry, Error>, usize, bool)>,
         Error
     > {
-        self.chunk_store.get_chunk_iterator(print_percentage)
+        self.chunk_store.get_chunk_iterator()
     }
 
     pub fn create_fixed_writer<P: AsRef<Path>>(&self, filename: P, size: usize, chunk_size: usize) -> Result<FixedIndexWriter, Error> {
@@ -94,25 +113,28 @@ impl DataStore {
 
     pub fn open_fixed_reader<P: AsRef<Path>>(&self, filename: P) -> Result<FixedIndexReader, Error> {
 
-        let index = FixedIndexReader::open(self.chunk_store.clone(), filename.as_ref())?;
+        let full_path =  self.chunk_store.relative_path(filename.as_ref());
+
+        let index = FixedIndexReader::open(&full_path)?;
 
         Ok(index)
     }
 
     pub fn create_dynamic_writer<P: AsRef<Path>>(
         &self, filename: P,
-        chunk_size: usize
     ) -> Result<DynamicIndexWriter, Error> {
 
         let index = DynamicIndexWriter::create(
-            self.chunk_store.clone(), filename.as_ref(), chunk_size)?;
+            self.chunk_store.clone(), filename.as_ref())?;
 
         Ok(index)
     }
 
     pub fn open_dynamic_reader<P: AsRef<Path>>(&self, filename: P) -> Result<DynamicIndexReader, Error> {
 
-        let index = DynamicIndexReader::open(self.chunk_store.clone(), filename.as_ref())?;
+        let full_path =  self.chunk_store.relative_path(filename.as_ref());
+
+        let index = DynamicIndexReader::open(&full_path)?;
 
         Ok(index)
     }
@@ -123,59 +145,236 @@ impl DataStore {
     {
         let filename = filename.as_ref();
         let out: Box<dyn IndexFile + Send> =
-            match filename.extension().and_then(|ext| ext.to_str()) {
-                Some("didx") => Box::new(self.open_dynamic_reader(filename)?),
-                Some("fidx") => Box::new(self.open_fixed_reader(filename)?),
+            match archive_type(filename)? {
+                ArchiveType::DynamicIndex => Box::new(self.open_dynamic_reader(filename)?),
+                ArchiveType::FixedIndex => Box::new(self.open_fixed_reader(filename)?),
                 _ => bail!("cannot open index file of unknown type: {:?}", filename),
             };
         Ok(out)
     }
 
+    pub fn name(&self) -> &str {
+        self.chunk_store.name()
+    }
+
     pub fn base_path(&self) -> PathBuf {
         self.chunk_store.base_path()
     }
 
-    /// Remove a backup directory including all content
-    pub fn remove_backup_dir(&self, backup_dir: &BackupDir,
-    ) ->  Result<(), io::Error> {
+    /// Cleanup a backup directory
+    ///
+    /// Removes all files not mentioned in the manifest.
+    pub fn cleanup_backup_dir(&self, backup_dir: &BackupDir, manifest: &BackupManifest
+    ) ->  Result<(), Error> {
 
-        let relative_path = backup_dir.relative_path();
         let mut full_path = self.base_path();
-        full_path.push(&relative_path);
+        full_path.push(backup_dir.relative_path());
 
-        log::info!("removing backup {:?}", full_path);
-        std::fs::remove_dir_all(full_path)?;
+        let mut wanted_files = HashSet::new();
+        wanted_files.insert(MANIFEST_BLOB_NAME.to_string());
+        wanted_files.insert(CLIENT_LOG_BLOB_NAME.to_string());
+        manifest.files().iter().for_each(|item| { wanted_files.insert(item.filename.clone()); });
+
+        for item in tools::fs::read_subdir(libc::AT_FDCWD, &full_path)? {
+            if let Ok(item) = item {
+                if let Some(file_type) = item.file_type() {
+                    if file_type != nix::dir::Type::File { continue; }
+                }
+                let file_name = item.file_name().to_bytes();
+                if file_name == b"." || file_name == b".." { continue; };
+
+                if let Ok(name) = std::str::from_utf8(file_name) {
+                    if wanted_files.contains(name) { continue; }
+                }
+                println!("remove unused file {:?}", item.file_name());
+                let dirfd = item.parent_fd();
+                let _res = unsafe { libc::unlinkat(dirfd, item.file_name().as_ptr(), 0) };
+            }
+        }
 
         Ok(())
     }
 
-    pub fn create_backup_dir(&self, backup_dir: &BackupDir) ->  Result<(PathBuf, bool), io::Error> {
+    /// Returns the absolute path for a backup_group
+    pub fn group_path(&self, backup_group: &BackupGroup) -> PathBuf {
+        let mut full_path = self.base_path();
+        full_path.push(backup_group.group_path());
+        full_path
+    }
+
+    /// Returns the absolute path for backup_dir
+    pub fn snapshot_path(&self, backup_dir: &BackupDir) -> PathBuf {
+        let mut full_path = self.base_path();
+        full_path.push(backup_dir.relative_path());
+        full_path
+    }
 
+    /// Remove a complete backup group including all snapshots
+    pub fn remove_backup_group(&self, backup_group: &BackupGroup) ->  Result<(), Error> {
+
+        let full_path = self.group_path(backup_group);
+
+        let _guard = tools::fs::lock_dir_noblock(&full_path, "backup group", "possible running backup")?;
+
+        log::info!("removing backup group {:?}", full_path);
+
+        // remove all individual backup dirs first to ensure nothing is using them
+        for snap in backup_group.list_backups(&self.base_path())? {
+            self.remove_backup_dir(&snap.backup_dir, false)?;
+        }
+
+        // no snapshots left, we can now safely remove the empty folder
+        std::fs::remove_dir_all(&full_path)
+            .map_err(|err| {
+                format_err!(
+                    "removing backup group directory {:?} failed - {}",
+                    full_path,
+                    err,
+                )
+            })?;
+
+        Ok(())
+    }
+
+    /// Remove a backup directory including all content
+    pub fn remove_backup_dir(&self, backup_dir: &BackupDir, force: bool) ->  Result<(), Error> {
+
+        let full_path = self.snapshot_path(backup_dir);
+
+        let (_guard, _manifest_guard);
+        if !force {
+            _guard = lock_dir_noblock(&full_path, "snapshot", "possibly running or in use")?;
+            _manifest_guard = self.lock_manifest(backup_dir)?;
+        }
+
+        log::info!("removing backup snapshot {:?}", full_path);
+        std::fs::remove_dir_all(&full_path)
+            .map_err(|err| {
+                format_err!(
+                    "removing backup snapshot {:?} failed - {}",
+                    full_path,
+                    err,
+                )
+            })?;
+
+        // the manifest does not exists anymore, we do not need to keep the lock
+        if let Ok(path) = self.manifest_lock_path(backup_dir) {
+            // ignore errors
+            let _ = std::fs::remove_file(path);
+        }
+
+        Ok(())
+    }
+
+    /// Returns the time of the last successful backup
+    ///
+    /// Or None if there is no backup in the group (or the group dir does not exist).
+    pub fn last_successful_backup(&self, backup_group: &BackupGroup) -> Result<Option<i64>, Error> {
+        let base_path = self.base_path();
+        let mut group_path = base_path.clone();
+        group_path.push(backup_group.group_path());
+
+        if group_path.exists() {
+            backup_group.last_successful_backup(&base_path)
+        } else {
+            Ok(None)
+        }
+    }
+
+    /// Returns the backup owner.
+    ///
+    /// The backup owner is the entity who first created the backup group.
+    pub fn get_owner(&self, backup_group: &BackupGroup) -> Result<Authid, Error> {
+        let mut full_path = self.base_path();
+        full_path.push(backup_group.group_path());
+        full_path.push("owner");
+        let owner = proxmox::tools::fs::file_read_firstline(full_path)?;
+        Ok(owner.trim_end().parse()?) // remove trailing newline
+    }
+
+    /// Set the backup owner.
+    pub fn set_owner(
+        &self,
+        backup_group: &BackupGroup,
+        auth_id: &Authid,
+        force: bool,
+    ) -> Result<(), Error> {
+        let mut path = self.base_path();
+        path.push(backup_group.group_path());
+        path.push("owner");
+
+        let mut open_options = std::fs::OpenOptions::new();
+        open_options.write(true);
+        open_options.truncate(true);
+
+        if force {
+            open_options.create(true);
+        } else {
+            open_options.create_new(true);
+        }
+
+        let mut file = open_options.open(&path)
+            .map_err(|err| format_err!("unable to create owner file {:?} - {}", path, err))?;
+
+        writeln!(file, "{}", auth_id)
+            .map_err(|err| format_err!("unable to write owner file  {:?} - {}", path, err))?;
+
+        Ok(())
+    }
+
+    /// Create (if it does not already exists) and lock a backup group
+    ///
+    /// And set the owner to 'userid'. If the group already exists, it returns the
+    /// current owner (instead of setting the owner).
+    ///
+    /// This also acquires an exclusive lock on the directory and returns the lock guard.
+    pub fn create_locked_backup_group(
+        &self,
+        backup_group: &BackupGroup,
+        auth_id: &Authid,
+    ) -> Result<(Authid, DirLockGuard), Error> {
         // create intermediate path first:
         let mut full_path = self.base_path();
-        full_path.push(backup_dir.group().group_path());
+        full_path.push(backup_group.backup_type());
         std::fs::create_dir_all(&full_path)?;
 
-        let relative_path = backup_dir.relative_path();
-        let mut full_path = self.base_path();
-        full_path.push(&relative_path);
+        full_path.push(backup_group.backup_id());
 
         // create the last component now
         match std::fs::create_dir(&full_path) {
-            Ok(_) => Ok((relative_path, true)),
-            Err(ref e) if e.kind() == io::ErrorKind::AlreadyExists => Ok((relative_path, false)),
-            Err(e) => Err(e)
+            Ok(_) => {
+                let guard = lock_dir_noblock(&full_path, "backup group", "another backup is already running")?;
+                self.set_owner(backup_group, auth_id, false)?;
+                let owner = self.get_owner(backup_group)?; // just to be sure
+                Ok((owner, guard))
+            }
+            Err(ref err) if err.kind() == io::ErrorKind::AlreadyExists => {
+                let guard = lock_dir_noblock(&full_path, "backup group", "another backup is already running")?;
+                let owner = self.get_owner(backup_group)?; // just to be sure
+                Ok((owner, guard))
+            }
+            Err(err) => bail!("unable to create backup group {:?} - {}", full_path, err),
         }
     }
 
-    pub fn list_backups(&self) -> Result<Vec<BackupInfo>, Error> {
-        let path = self.base_path();
-        BackupInfo::list_backups(&path)
-    }
+    /// Creates a new backup snapshot inside a BackupGroup
+    ///
+    /// The BackupGroup directory needs to exist.
+    pub fn create_locked_backup_dir(&self, backup_dir: &BackupDir)
+        -> Result<(PathBuf, bool, DirLockGuard), Error>
+    {
+        let relative_path = backup_dir.relative_path();
+        let mut full_path = self.base_path();
+        full_path.push(&relative_path);
+
+        let lock = ||
+            lock_dir_noblock(&full_path, "snapshot", "internal error - tried creating snapshot that's already in use");
 
-    pub fn list_files(&self, backup_dir: &BackupDir) -> Result<Vec<String>, Error> {
-        let path = self.base_path();
-        BackupInfo::list_files(&path, backup_dir)
+        match std::fs::create_dir(&full_path) {
+            Ok(_) => Ok((relative_path, true, lock()?)),
+            Err(ref e) if e.kind() == io::ErrorKind::AlreadyExists => Ok((relative_path, false, lock()?)),
+            Err(e) => Err(e.into())
+        }
     }
 
     pub fn list_images(&self) -> Result<Vec<PathBuf>, Error> {
@@ -185,22 +384,43 @@ impl DataStore {
 
         use walkdir::WalkDir;
 
-        let walker = WalkDir::new(&base).same_file_system(true).into_iter();
+        let walker = WalkDir::new(&base).into_iter();
 
         // make sure we skip .chunks (and other hidden files to keep it simple)
         fn is_hidden(entry: &walkdir::DirEntry) -> bool {
             entry.file_name()
                 .to_str()
-                .map(|s| s.starts_with("."))
+                .map(|s| s.starts_with('.'))
                 .unwrap_or(false)
         }
-
+        let handle_entry_err = |err: walkdir::Error| {
+            if let Some(inner) = err.io_error() {
+                if let Some(path) = err.path() {
+                    if inner.kind() == io::ErrorKind::PermissionDenied {
+                        // only allow to skip ext4 fsck directory, avoid GC if, for example,
+                        // a user got file permissions wrong on datastore rsync to new server
+                        if err.depth() > 1 || !path.ends_with("lost+found") {
+                            bail!("cannot continue garbage-collection safely, permission denied on: {:?}", path)
+                        }
+                    } else {
+                        bail!("unexpected error on datastore traversal: {} - {:?}", inner, path)
+                    }
+                } else {
+                    bail!("unexpected error on datastore traversal: {}", inner)
+                }
+            }
+            Ok(())
+        };
         for entry in walker.filter_entry(|e| !is_hidden(e)) {
-            let path = entry?.into_path();
-            if let Some(ext) = path.extension() {
-                if ext == "fidx" {
-                    list.push(path);
-                } else if ext == "didx" {
+            let path = match entry {
+                Ok(entry) => entry.into_path(),
+                Err(err) => {
+                    handle_entry_err(err)?;
+                    continue
+                },
+            };
+            if let Ok(archive_type) = archive_type(&path) {
+                if archive_type == ArchiveType::FixedIndex || archive_type == ArchiveType::DynamicIndex {
                     list.push(path);
                 }
             }
@@ -209,25 +429,114 @@ impl DataStore {
         Ok(list)
     }
 
-    fn mark_used_chunks(&self, status: &mut GarbageCollectionStatus) -> Result<(), Error> {
+    // mark chunks  used by ``index`` as used
+    fn index_mark_used_chunks<I: IndexFile>(
+        &self,
+        index: I,
+        file_name: &Path, // only used for error reporting
+        status: &mut GarbageCollectionStatus,
+        worker: &dyn TaskState,
+    ) -> Result<(), Error> {
+
+        status.index_file_count += 1;
+        status.index_data_bytes += index.index_bytes();
+
+        for pos in 0..index.index_count() {
+            worker.check_abort()?;
+            tools::fail_on_shutdown()?;
+            let digest = index.index_digest(pos).unwrap();
+            if !self.chunk_store.cond_touch_chunk(digest, false)? {
+                crate::task_warn!(
+                    worker,
+                    "warning: unable to access non-existent chunk {}, required by {:?}",
+                    proxmox::tools::digest_to_hex(digest),
+                    file_name,
+                );
+
+                // touch any corresponding .bad files to keep them around, meaning if a chunk is
+                // rewritten correctly they will be removed automatically, as well as if no index
+                // file requires the chunk anymore (won't get to this loop then)
+                for i in 0..=9 {
+                    let bad_ext = format!("{}.bad", i);
+                    let mut bad_path = PathBuf::new();
+                    bad_path.push(self.chunk_path(digest).0);
+                    bad_path.set_extension(bad_ext);
+                    self.chunk_store.cond_touch_path(&bad_path, false)?;
+                }
+            }
+        }
+        Ok(())
+    }
+
+    fn mark_used_chunks(
+        &self,
+        status: &mut GarbageCollectionStatus,
+        worker: &dyn TaskState,
+    ) -> Result<(), Error> {
 
         let image_list = self.list_images()?;
+        let image_count = image_list.len();
+
+        let mut last_percentage: usize = 0;
+
+        let mut strange_paths_count: u64 = 0;
 
-        for path in image_list {
+        for (i, img) in image_list.into_iter().enumerate() {
 
+            worker.check_abort()?;
             tools::fail_on_shutdown()?;
 
-            if let Some(ext) = path.extension() {
-                if ext == "fidx" {
-                    let index = self.open_fixed_reader(&path)?;
-                    index.mark_used_chunks(status)?;
-                } else if ext == "didx" {
-                    let index = self.open_dynamic_reader(&path)?;
-                    index.mark_used_chunks(status)?;
+            if let Some(backup_dir_path) = img.parent() {
+                let backup_dir_path = backup_dir_path.strip_prefix(self.base_path())?;
+                if let Some(backup_dir_str) = backup_dir_path.to_str() {
+                    if BackupDir::from_str(backup_dir_str).is_err() {
+                        strange_paths_count += 1;
+                    }
+                }
+            }
+
+            match std::fs::File::open(&img) {
+                Ok(file) => {
+                    if let Ok(archive_type) = archive_type(&img) {
+                        if archive_type == ArchiveType::FixedIndex {
+                            let index = FixedIndexReader::new(file).map_err(|e| {
+                                format_err!("can't read index '{}' - {}", img.to_string_lossy(), e)
+                            })?;
+                            self.index_mark_used_chunks(index, &img, status, worker)?;
+                        } else if archive_type == ArchiveType::DynamicIndex {
+                            let index = DynamicIndexReader::new(file).map_err(|e| {
+                                format_err!("can't read index '{}' - {}", img.to_string_lossy(), e)
+                            })?;
+                            self.index_mark_used_chunks(index, &img, status, worker)?;
+                        }
+                    }
                 }
+                Err(err) if err.kind() == io::ErrorKind::NotFound => (), // ignore vanished files
+                Err(err) => bail!("can't open index {} - {}", img.to_string_lossy(), err),
+            }
+
+            let percentage = (i + 1) * 100 / image_count;
+            if percentage > last_percentage {
+                crate::task_log!(
+                    worker,
+                    "marked {}% ({} of {} index files)",
+                    percentage,
+                    i + 1,
+                    image_count,
+                );
+                last_percentage = percentage;
             }
         }
 
+        if strange_paths_count > 0 {
+            crate::task_log!(
+                worker,
+                "found (and marked) {} index files outside of expected directory scheme",
+                strange_paths_count,
+            );
+        }
+
+
         Ok(())
     }
 
@@ -235,28 +544,106 @@ impl DataStore {
         self.last_gc_status.lock().unwrap().clone()
     }
 
-    pub fn garbage_collection(&self, worker: Arc<WorkerTask>) -> Result<(), Error> {
+    pub fn garbage_collection_running(&self) -> bool {
+        !matches!(self.gc_mutex.try_lock(), Ok(_))
+    }
+
+    pub fn garbage_collection(&self, worker: &dyn TaskState, upid: &UPID) -> Result<(), Error> {
 
         if let Ok(ref mut _mutex) = self.gc_mutex.try_lock() {
 
+            // avoids that we run GC if an old daemon process has still a
+            // running backup writer, which is not save as we have no "oldest
+            // writer" information and thus no safe atime cutoff
             let _exclusive_lock =  self.chunk_store.try_exclusive_lock()?;
 
-            let oldest_writer = self.chunk_store.oldest_writer();
+            let phase1_start_time = proxmox::tools::time::epoch_i64();
+            let oldest_writer = self.chunk_store.oldest_writer().unwrap_or(phase1_start_time);
 
             let mut gc_status = GarbageCollectionStatus::default();
-            gc_status.upid = Some(worker.to_string());
+            gc_status.upid = Some(upid.to_string());
+
+            crate::task_log!(worker, "Start GC phase1 (mark used chunks)");
+
+            self.mark_used_chunks(&mut gc_status, worker)?;
+
+            crate::task_log!(worker, "Start GC phase2 (sweep unused chunks)");
+            self.chunk_store.sweep_unused_chunks(
+                oldest_writer,
+                phase1_start_time,
+                &mut gc_status,
+                worker,
+            )?;
+
+            crate::task_log!(
+                worker,
+                "Removed garbage: {}",
+                HumanByte::from(gc_status.removed_bytes),
+            );
+            crate::task_log!(worker, "Removed chunks: {}", gc_status.removed_chunks);
+            if gc_status.pending_bytes > 0 {
+                crate::task_log!(
+                    worker,
+                    "Pending removals: {} (in {} chunks)",
+                    HumanByte::from(gc_status.pending_bytes),
+                    gc_status.pending_chunks,
+                );
+            }
+            if gc_status.removed_bad > 0 {
+                crate::task_log!(worker, "Removed bad chunks: {}", gc_status.removed_bad);
+            }
+
+            if gc_status.still_bad > 0 {
+                crate::task_log!(worker, "Leftover bad chunks: {}", gc_status.still_bad);
+            }
+
+            crate::task_log!(
+                worker,
+                "Original data usage: {}",
+                HumanByte::from(gc_status.index_data_bytes),
+            );
+
+            if gc_status.index_data_bytes > 0 {
+                let comp_per = (gc_status.disk_bytes as f64 * 100.)/gc_status.index_data_bytes as f64;
+                crate::task_log!(
+                    worker,
+                    "On-Disk usage: {} ({:.2}%)",
+                    HumanByte::from(gc_status.disk_bytes),
+                    comp_per,
+                );
+            }
 
-            worker.log("Start GC phase1 (mark chunks)");
+            crate::task_log!(worker, "On-Disk chunks: {}", gc_status.disk_chunks);
 
-            self.mark_used_chunks(&mut gc_status)?;
+            let deduplication_factor = if gc_status.disk_bytes > 0 {
+                (gc_status.index_data_bytes as f64)/(gc_status.disk_bytes as f64)
+            } else {
+                1.0
+            };
 
-            worker.log("Start GC phase2 (sweep unused chunks)");
-            self.chunk_store.sweep_unused_chunks(oldest_writer, &mut gc_status)?;
+            crate::task_log!(worker, "Deduplication factor: {:.2}", deduplication_factor);
 
-            worker.log(&format!("Used bytes: {}", gc_status.used_bytes));
-            worker.log(&format!("Used chunks: {}", gc_status.used_chunks));
-            worker.log(&format!("Disk bytes: {}", gc_status.disk_bytes));
-            worker.log(&format!("Disk chunks: {}", gc_status.disk_chunks));
+            if gc_status.disk_chunks > 0 {
+                let avg_chunk = gc_status.disk_bytes/(gc_status.disk_chunks as u64);
+                crate::task_log!(worker, "Average chunk size: {}", HumanByte::from(avg_chunk));
+            }
+
+            if let Ok(serialized) = serde_json::to_string(&gc_status) {
+                let mut path = self.base_path();
+                path.push(".gc-status");
+
+                let backup_user = crate::backup::backup_user()?;
+                let mode = nix::sys::stat::Mode::from_bits_truncate(0o0644);
+                // set the correct owner/group/permissions while saving file
+                // owner(rw) = backup, group(r)= backup
+                let options = CreateOptions::new()
+                    .perm(mode)
+                    .owner(backup_user.uid)
+                    .group(backup_user.gid);
+
+                // ignore errors
+                let _ = replace_file(path, serialized.as_bytes(), options);
+            }
 
             *self.last_gc_status.lock().unwrap() = gc_status;
 
@@ -267,15 +654,131 @@ impl DataStore {
         Ok(())
     }
 
-    pub fn insert_chunk(&self, chunk: &[u8]) -> Result<(bool, [u8; 32], u64), Error> {
-        self.chunk_store.insert_chunk(chunk)
+    pub fn try_shared_chunk_store_lock(&self) -> Result<tools::ProcessLockSharedGuard, Error> {
+        self.chunk_store.try_shared_lock()
+    }
+
+    pub fn chunk_path(&self, digest:&[u8; 32]) -> (PathBuf, String) {
+        self.chunk_store.chunk_path(digest)
+    }
+
+    pub fn cond_touch_chunk(&self, digest: &[u8; 32], fail_if_not_exist: bool) -> Result<bool, Error> {
+        self.chunk_store.cond_touch_chunk(digest, fail_if_not_exist)
     }
 
-    pub fn insert_chunk_noverify(
+    pub fn insert_chunk(
         &self,
+        chunk: &DataBlob,
         digest: &[u8; 32],
-        chunk: &[u8],
     ) -> Result<(bool, u64), Error> {
-        self.chunk_store.insert_chunk_noverify(digest, chunk)
+        self.chunk_store.insert_chunk(chunk, digest)
+    }
+
+    pub fn load_blob(&self, backup_dir: &BackupDir, filename: &str) -> Result<DataBlob, Error> {
+        let mut path = self.base_path();
+        path.push(backup_dir.relative_path());
+        path.push(filename);
+
+        proxmox::try_block!({
+            let mut file = std::fs::File::open(&path)?;
+            DataBlob::load_from_reader(&mut file)
+        }).map_err(|err| format_err!("unable to load blob '{:?}' - {}", path, err))
+    }
+
+
+    pub fn load_chunk(&self, digest: &[u8; 32]) -> Result<DataBlob, Error> {
+
+        let (chunk_path, digest_str) = self.chunk_store.chunk_path(digest);
+
+        proxmox::try_block!({
+            let mut file = std::fs::File::open(&chunk_path)?;
+            DataBlob::load_from_reader(&mut file)
+        }).map_err(|err| format_err!(
+            "store '{}', unable to load chunk '{}' - {}",
+            self.name(),
+            digest_str,
+            err,
+        ))
+    }
+
+    /// Returns the filename to lock a manifest
+    ///
+    /// Also creates the basedir. The lockfile is located in
+    /// '/run/proxmox-backup/locks/{datastore}/{type}/{id}/{timestamp}.index.json.lck'
+    fn manifest_lock_path(
+        &self,
+        backup_dir: &BackupDir,
+    ) -> Result<String, Error> {
+        let mut path = format!(
+            "/run/proxmox-backup/locks/{}/{}/{}",
+            self.name(),
+            backup_dir.group().backup_type(),
+            backup_dir.group().backup_id(),
+        );
+        std::fs::create_dir_all(&path)?;
+        use std::fmt::Write;
+        write!(path, "/{}{}", backup_dir.backup_time_string(), &MANIFEST_LOCK_NAME)?;
+
+        Ok(path)
+    }
+
+    fn lock_manifest(
+        &self,
+        backup_dir: &BackupDir,
+    ) -> Result<File, Error> {
+        let path = self.manifest_lock_path(backup_dir)?;
+
+        // update_manifest should never take a long time, so if someone else has
+        // the lock we can simply block a bit and should get it soon
+        open_file_locked(&path, Duration::from_secs(5), true)
+            .map_err(|err| {
+                format_err!(
+                    "unable to acquire manifest lock {:?} - {}", &path, err
+                )
+            })
+    }
+
+    /// Load the manifest without a lock. Must not be written back.
+    pub fn load_manifest(
+        &self,
+        backup_dir: &BackupDir,
+    ) -> Result<(BackupManifest, u64), Error> {
+        let blob = self.load_blob(backup_dir, MANIFEST_BLOB_NAME)?;
+        let raw_size = blob.raw_size();
+        let manifest = BackupManifest::try_from(blob)?;
+        Ok((manifest, raw_size))
+    }
+
+    /// Update the manifest of the specified snapshot. Never write a manifest directly,
+    /// only use this method - anything else may break locking guarantees.
+    pub fn update_manifest(
+        &self,
+        backup_dir: &BackupDir,
+        update_fn: impl FnOnce(&mut BackupManifest),
+    ) -> Result<(), Error> {
+
+        let _guard = self.lock_manifest(backup_dir)?;
+        let (mut manifest, _) = self.load_manifest(&backup_dir)?;
+
+        update_fn(&mut manifest);
+
+        let manifest = serde_json::to_value(manifest)?;
+        let manifest = serde_json::to_string_pretty(&manifest)?;
+        let blob = DataBlob::encode(manifest.as_bytes(), None, true)?;
+        let raw_data = blob.raw_data();
+
+        let mut path = self.base_path();
+        path.push(backup_dir.relative_path());
+        path.push(MANIFEST_BLOB_NAME);
+
+        // atomic replace invalidates flock - no other writes past this point!
+        replace_file(&path, raw_data, CreateOptions::new())?;
+
+        Ok(())
+    }
+
+    pub fn verify_new(&self) -> bool {
+        self.verify_new
     }
 }
+