[RFC PATCH proxmox-backup 3/4] datastore: api: add option to rebuild S3 chunk markers

[Shan Shaji <s.shaji@proxmox.com>]

Add the optional `rebuild-chunk-markers` flag to the datastore
`s3-refresh` API endpoint. When enabled, the refresh lists all chunk
objects in S3 and recreates their local marker files.

Existing local chunk files are replaced with empty marker files. The
option is disabled by default.

Signed-off-by: Shan Shaji <s.shaji@proxmox.com>
---
 src/api2/admin/datastore.rs | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/src/api2/admin/datastore.rs b/src/api2/admin/datastore.rs
index 34907fa0a..5df5a6b63 100644
--- a/src/api2/admin/datastore.rs
+++ b/src/api2/admin/datastore.rs
@@ -2835,6 +2835,13 @@ pub async fn unmount(store: String, rpcenv: &mut dyn RpcEnvironment) -> Result<V
             store: {
                 schema: DATASTORE_SCHEMA,
             },
+            "rebuild-chunk-markers": {
+                description: "Create local chunk marker files for all chunks stored in S3. This \
+                requires listing all chunk objects and may take long time for large datastores.",
+                type: bool,
+                optional: true,
+                default: false,
+            },
         }
     },
     returns: {
@@ -2845,7 +2852,11 @@ pub async fn unmount(store: String, rpcenv: &mut dyn RpcEnvironment) -> Result<V
     },
 )]
 /// Refresh datastore contents from S3 to local cache store.
-pub fn s3_refresh(store: String, rpcenv: &mut dyn RpcEnvironment) -> Result<Value, Error> {
+pub fn s3_refresh(
+    store: String,
+    rebuild_chunk_markers: bool,
+    rpcenv: &mut dyn RpcEnvironment,
+) -> Result<Value, Error> {
     let auth_id: Authid = rpcenv.get_auth_id().unwrap().parse()?;
     let to_stdout = rpcenv.env_type() == RpcEnvironmentType::CLI;
 
@@ -2867,7 +2878,7 @@ pub fn s3_refresh(store: String, rpcenv: &mut dyn RpcEnvironment) -> Result<Valu
         Some(store.clone()),
         auth_id.to_string(),
         to_stdout,
-        move |worker| do_s3_refresh(&store, &worker, false),
+        move |worker| do_s3_refresh(&store, &worker, rebuild_chunk_markers),
     )?;
 
     Ok(json!(upid))
-- 
2.47.3