improve internal item counter mechanisms and implement bucket quotas (#326)

- [x] Refactoring of internal counting API
- [x] Repair procedure for counters (it's an offline procedure!!!)
- [x] New counter for objects in buckets
- [x] Add quotas to buckets struct
- [x] Add CLI to manage bucket quotas
- [x] Add admin API to manage bucket quotas
- [x] Apply quotas by adding checks on put operations
- [x] Proof-read

Co-authored-by: Alex Auvolat <alex@adnab.me>
Reviewed-on: https://git.deuxfleurs.fr/Deuxfleurs/garage/pulls/326
Co-authored-by: Alex <alex@adnab.me>
Co-committed-by: Alex <alex@adnab.me>

3 files changed, 220 insertions, 0 deletions

diff --git a/src/garage/repair/mod.rs b/src/garage/repair/mod.rs
new file mode 100644
index 00000000..4699ace5
--- /dev/null
+++ b/src/garage/repair/mod.rs
@@ -0,0 +1,2 @@
+pub mod offline;
+pub mod online;
diff --git a/src/garage/repair/offline.rs b/src/garage/repair/offline.rs
new file mode 100644
index 00000000..7760a8bd
--- /dev/null
+++ b/src/garage/repair/offline.rs
@@ -0,0 +1,55 @@
+use std::path::PathBuf;
+
+use tokio::sync::watch;
+
+use garage_util::background::*;
+use garage_util::config::*;
+use garage_util::error::*;
+
+use garage_model::garage::Garage;
+
+use crate::cli::structs::*;
+
+pub async fn offline_repair(config_file: PathBuf, opt: OfflineRepairOpt) -> Result<(), Error> {
+	if !opt.yes {
+		return Err(Error::Message(
+			"Please add the --yes flag to launch repair operation".into(),
+		));
+	}
+
+	info!("Loading configuration...");
+	let config = read_config(config_file)?;
+
+	info!("Initializing background runner...");
+	let (done_tx, done_rx) = watch::channel(false);
+	let (background, await_background_done) = BackgroundRunner::new(16, done_rx);
+
+	info!("Initializing Garage main data store...");
+	let garage = Garage::new(config.clone(), background)?;
+
+	info!("Launching repair operation...");
+	match opt.what {
+		#[cfg(feature = "k2v")]
+		OfflineRepairWhat::K2VItemCounters => {
+			garage
+				.k2v
+				.counter_table
+				.offline_recount_all(&garage.k2v.item_table)?;
+		}
+		OfflineRepairWhat::ObjectCounters => {
+			garage
+				.object_counter_table
+				.offline_recount_all(&garage.object_table)?;
+		}
+	}
+
+	info!("Repair operation finished, shutting down Garage internals...");
+	done_tx.send(true).unwrap();
+	drop(garage);
+
+	await_background_done.await?;
+
+	info!("Cleaning up...");
+
+	Ok(())
+}
diff --git a/src/garage/repair/online.rs b/src/garage/repair/online.rs
new file mode 100644
index 00000000..d6a71742
--- /dev/null
+++ b/src/garage/repair/online.rs
@@ -0,0 +1,163 @@
+use std::sync::Arc;
+
+use tokio::sync::watch;
+
+use garage_model::garage::Garage;
+use garage_model::s3::block_ref_table::*;
+use garage_model::s3::object_table::*;
+use garage_model::s3::version_table::*;
+use garage_table::*;
+use garage_util::error::Error;
+
+use crate::*;
+
+pub struct OnlineRepair {
+	pub garage: Arc<Garage>,
+}
+
+impl OnlineRepair {
+	pub async fn repair_worker(&self, opt: RepairOpt, must_exit: watch::Receiver<bool>) {
+		if let Err(e) = self.repair_worker_aux(opt, must_exit).await {
+			warn!("Repair worker failed with error: {}", e);
+		}
+	}
+
+	async fn repair_worker_aux(
+		&self,
+		opt: RepairOpt,
+		must_exit: watch::Receiver<bool>,
+	) -> Result<(), Error> {
+		match opt.what {
+			RepairWhat::Tables => {
+				info!("Launching a full sync of tables");
+				self.garage.bucket_table.syncer.add_full_sync();
+				self.garage.object_table.syncer.add_full_sync();
+				self.garage.version_table.syncer.add_full_sync();
+				self.garage.block_ref_table.syncer.add_full_sync();
+				self.garage.key_table.syncer.add_full_sync();
+			}
+			RepairWhat::Versions => {
+				info!("Repairing the versions table");
+				self.repair_versions(&must_exit).await?;
+			}
+			RepairWhat::BlockRefs => {
+				info!("Repairing the block refs table");
+				self.repair_block_ref(&must_exit).await?;
+			}
+			RepairWhat::Blocks => {
+				info!("Repairing the stored blocks");
+				self.garage
+					.block_manager
+					.repair_data_store(&must_exit)
+					.await?;
+			}
+			RepairWhat::Scrub { tranquility } => {
+				info!("Verifying integrity of stored blocks");
+				self.garage
+					.block_manager
+					.scrub_data_store(&must_exit, tranquility)
+					.await?;
+			}
+		}
+		Ok(())
+	}
+
+	async fn repair_versions(&self, must_exit: &watch::Receiver<bool>) -> Result<(), Error> {
+		let mut pos = vec![];
+		let mut i = 0;
+
+		while !*must_exit.borrow() {
+			let item_bytes = match self.garage.version_table.data.store.get_gt(pos)? {
+				Some((k, v)) => {
+					pos = k;
+					v
+				}
+				None => break,
+			};
+
+			i += 1;
+			if i % 1000 == 0 {
+				info!("repair_versions: {}", i);
+			}
+
+			let version = rmp_serde::decode::from_read_ref::<_, Version>(&item_bytes)?;
+			if version.deleted.get() {
+				continue;
+			}
+			let object = self
+				.garage
+				.object_table
+				.get(&version.bucket_id, &version.key)
+				.await?;
+			let version_exists = match object {
+				Some(o) => o
+					.versions()
+					.iter()
+					.any(|x| x.uuid == version.uuid && x.state != ObjectVersionState::Aborted),
+				None => false,
+			};
+			if !version_exists {
+				info!("Repair versions: marking version as deleted: {:?}", version);
+				self.garage
+					.version_table
+					.insert(&Version::new(
+						version.uuid,
+						version.bucket_id,
+						version.key,
+						true,
+					))
+					.await?;
+			}
+		}
+		info!("repair_versions: finished, done {}", i);
+		Ok(())
+	}
+
+	async fn repair_block_ref(&self, must_exit: &watch::Receiver<bool>) -> Result<(), Error> {
+		let mut pos = vec![];
+		let mut i = 0;
+
+		while !*must_exit.borrow() {
+			let item_bytes = match self.garage.block_ref_table.data.store.get_gt(pos)? {
+				Some((k, v)) => {
+					pos = k;
+					v
+				}
+				None => break,
+			};
+
+			i += 1;
+			if i % 1000 == 0 {
+				info!("repair_block_ref: {}", i);
+			}
+
+			let block_ref = rmp_serde::decode::from_read_ref::<_, BlockRef>(&item_bytes)?;
+			if block_ref.deleted.get() {
+				continue;
+			}
+			let version = self
+				.garage
+				.version_table
+				.get(&block_ref.version, &EmptyKey)
+				.await?;
+			// The version might not exist if it has been GC'ed
+			let ref_exists = version.map(|v| !v.deleted.get()).unwrap_or(false);
+			if !ref_exists {
+				info!(
+					"Repair block ref: marking block_ref as deleted: {:?}",
+					block_ref
+				);
+				self.garage
+					.block_ref_table
+					.insert(&BlockRef {
+						block: block_ref.block,
+						version: block_ref.version,
+						deleted: true.into(),
+					})
+					.await?;
+			}
+		}
+		info!("repair_block_ref: finished, done {}", i);
+		Ok(())
+	}
+}