From a0a002b17fda2028afbc21585351d3399592a01f Mon Sep 17 00:00:00 2001
From: Jason Volk <jason@zemos.net>
Date: Tue, 30 Jul 2024 02:06:15 +0000
Subject: [PATCH] disable legacy media compat by default; cleanse directory
 when disabled

Signed-off-by: Jason Volk <jason@zemos.net>
---
 src/core/config/mod.rs            |  2 +-
 src/service/globals/migrations.rs | 32 +++++++++++++++++++++++++++++--
 src/service/media/mod.rs          | 13 +++++++++----
 3 files changed, 40 insertions(+), 7 deletions(-)

diff --git a/src/core/config/mod.rs b/src/core/config/mod.rs
index a9443fd2..6ccb0559 100644
--- a/src/core/config/mod.rs
+++ b/src/core/config/mod.rs
@@ -287,7 +287,7 @@ pub struct Config {
 
 	#[serde(default = "true_fn")]
 	pub media_startup_check: bool,
-	#[serde(default = "true_fn")]
+	#[serde(default)]
 	pub media_compat_file_link: bool,
 	#[serde(default = "Vec::new")]
 	pub prevent_media_downloads_from: Vec<OwnedServerName>,
diff --git a/src/service/globals/migrations.rs b/src/service/globals/migrations.rs
index 2fe22b0e..5e078595 100644
--- a/src/service/globals/migrations.rs
+++ b/src/service/globals/migrations.rs
@@ -743,6 +743,7 @@ async fn db_lt_13(services: &Services) -> Result<()> {
 /// again.
 async fn migrate_sha256_media(services: &Services) -> Result<()> {
 	let db = &services.db;
+	let config = &services.server.config;
 
 	warn!("Migrating legacy base64 file names to sha256 file names");
 	let mediaid_file = &db["mediaid_file"];
@@ -759,7 +760,9 @@ async fn migrate_sha256_media(services: &Services) -> Result<()> {
 	for (old_path, path) in changes {
 		if old_path.exists() {
 			tokio::fs::rename(&old_path, &path).await?;
-			tokio::fs::symlink(&path, &old_path).await?;
+			if config.media_compat_file_link {
+				tokio::fs::symlink(&path, &old_path).await?;
+			}
 		}
 	}
 
@@ -822,8 +825,14 @@ async fn handle_media_check(
 
 	let (mediaid_file, mediaid_user) = dbs;
 
-	let old_exists = files.contains(old_path);
 	let new_exists = files.contains(new_path);
+	let old_exists = files.contains(old_path);
+	let old_is_symlink = || async {
+		tokio::fs::symlink_metadata(old_path)
+			.await
+			.map_or(false, |md| md.is_symlink())
+	};
+
 	if !old_exists && !new_exists {
 		error!(
 			media_id = ?encode_key(key), ?new_path, ?old_path,
@@ -849,10 +858,29 @@ async fn handle_media_check(
 			"Legacy media found without sha256 migration. Fixing..."
 		);
 
+		debug_assert!(
+			old_is_symlink().await,
+			"Legacy media not expected to be a symlink without an existing sha256 migration."
+		);
+
 		tokio::fs::rename(&old_path, &new_path).await?;
 		tokio::fs::symlink(&new_path, &old_path).await?;
 	}
 
+	if !config.media_compat_file_link && old_exists && old_is_symlink().await {
+		debug_warn!(
+			media_id = ?encode_key(key), ?new_path, ?old_path,
+			"Legacy link found but compat disabled. Cleansing symlink..."
+		);
+
+		debug_assert!(
+			new_exists,
+			"sha256 migration into new file expected prior to cleaning legacy symlink here."
+		);
+
+		tokio::fs::remove_file(&old_path).await?;
+	}
+
 	Ok(())
 }
 
diff --git a/src/service/media/mod.rs b/src/service/media/mod.rs
index d5d518dc..1faa9768 100644
--- a/src/service/media/mod.rs
+++ b/src/service/media/mod.rs
@@ -6,7 +6,7 @@ use std::{path::PathBuf, sync::Arc, time::SystemTime};
 
 use async_trait::async_trait;
 use base64::{engine::general_purpose, Engine as _};
-use conduit::{debug, debug_error, err, error, utils, utils::MutexMap, Err, Result, Server};
+use conduit::{debug, debug_error, err, error, trace, utils, utils::MutexMap, Err, Result, Server};
 use data::{Data, Metadata};
 use ruma::{OwnedMxcUri, OwnedUserId};
 use serde::Serialize;
@@ -99,10 +99,15 @@ impl Service {
 	pub async fn delete(&self, mxc: &str) -> Result<()> {
 		if let Ok(keys) = self.db.search_mxc_metadata_prefix(mxc) {
 			for key in keys {
-				self.remove_media_file(&key).await?;
+				trace!(?mxc, ?key, "Deleting from filesystem");
+				if let Err(e) = self.remove_media_file(&key).await {
+					error!(?mxc, ?key, "Failed to remove media file: {e}");
+				}
 
-				debug!("Deleting MXC {mxc} from database");
-				self.db.delete_file_mxc(mxc)?;
+				trace!(?mxc, ?key, "Deleting from database");
+				if let Err(e) = self.db.delete_file_mxc(mxc) {
+					error!(?mxc, ?key, "Failed to remove media from database: {e}");
+				}
 			}
 
 			Ok(())