From 5fd823c3f2877fb83e806cb248ff16578a67829d Mon Sep 17 00:00:00 2001
From: Hannes Laimer <h.laimer@proxmox.com>
Date: Tue, 12 Apr 2022 05:26:00 +0000
Subject: [PATCH] api: add get_active_operations endpoint

Signed-off-by: Hannes Laimer <h.laimer@proxmox.com>
---
 pbs-datastore/src/task_tracking.rs | 61 ++++++++++++++++++++++--------
 src/api2/admin/datastore.rs        | 31 ++++++++++++++-
 2 files changed, 75 insertions(+), 17 deletions(-)

diff --git a/pbs-datastore/src/task_tracking.rs b/pbs-datastore/src/task_tracking.rs
index a02d9a17..c0a419e4 100644
--- a/pbs-datastore/src/task_tracking.rs
+++ b/pbs-datastore/src/task_tracking.rs
@@ -1,6 +1,7 @@
 use anyhow::Error;
 use libc::pid_t;
 use nix::unistd::Pid;
+use std::iter::Sum;
 use std::path::PathBuf;
 
 use pbs_api_types::Operation;
@@ -8,12 +9,46 @@ use proxmox_sys::fs::{file_read_optional_string, open_file_locked, replace_file,
 use proxmox_sys::linux::procfs;
 use serde::{Deserialize, Serialize};
 
+#[derive(Deserialize, Serialize, Clone, Copy, Default)]
+pub struct ActiveOperationStats {
+    pub read: i64,
+    pub write: i64,
+}
+
+impl Sum<Self> for ActiveOperationStats {
+    fn sum<I>(iter: I) -> Self
+    where
+        I: Iterator<Item = Self>,
+    {
+        iter.fold(Self::default(), |a, b| Self {
+            read: a.read + b.read,
+            write: a.write + b.write,
+        })
+    }
+}
+
 #[derive(Deserialize, Serialize, Clone)]
 struct TaskOperations {
     pid: u32,
     starttime: u64,
-    reading_operations: i64,
-    writing_operations: i64,
+    active_operations: ActiveOperationStats,
+}
+
+pub fn get_active_operations(name: &str) -> Result<ActiveOperationStats, Error> {
+    let path = PathBuf::from(format!("{}/{}", crate::ACTIVE_OPERATIONS_DIR, name));
+
+    Ok(match file_read_optional_string(&path)? {
+        Some(data) => serde_json::from_str::<Vec<TaskOperations>>(&data)?
+            .iter()
+            .filter_map(
+                |task| match procfs::check_process_running(task.pid as pid_t) {
+                    Some(stat) if task.starttime == stat.starttime => Some(task.active_operations),
+                    _ => None,
+                },
+            )
+            .sum(),
+        None => ActiveOperationStats::default(),
+    })
 }
 
 pub fn update_active_operations(name: &str, operation: Operation, count: i64) -> Result<(), Error> {
@@ -43,8 +78,8 @@ pub fn update_active_operations(name: &str, operation: Operation, count: i64) ->
                         if pid == task.pid {
                             updated = true;
                             match operation {
-                                Operation::Read => task.reading_operations += count,
-                                Operation::Write => task.writing_operations += count,
+                                Operation::Read => task.active_operations.read += count,
+                                Operation::Write => task.active_operations.write += count,
                             };
                         }
                         Some(task.clone())
@@ -57,18 +92,12 @@ pub fn update_active_operations(name: &str, operation: Operation, count: i64) ->
     };
 
     if !updated {
-        updated_tasks.push(match operation {
-            Operation::Read => TaskOperations {
-                pid,
-                starttime,
-                reading_operations: 1,
-                writing_operations: 0,
-            },
-            Operation::Write => TaskOperations {
-                pid,
-                starttime,
-                reading_operations: 0,
-                writing_operations: 1,
+        updated_tasks.push(TaskOperations {
+            pid,
+            starttime,
+            active_operations: match operation {
+                Operation::Read => ActiveOperationStats { read: 1, write: 0 },
+                Operation::Write => ActiveOperationStats { read: 0, write: 1 },
             },
         })
     }
diff --git a/src/api2/admin/datastore.rs b/src/api2/admin/datastore.rs
index d241efb5..02d8939c 100644
--- a/src/api2/admin/datastore.rs
+++ b/src/api2/admin/datastore.rs
@@ -43,7 +43,7 @@ use pbs_api_types::{ Authid, BackupContent, Counts, CryptMode,
 use pbs_client::pxar::create_zip;
 use pbs_datastore::{
     check_backup_owner, DataStore, BackupDir, BackupGroup, StoreProgress, LocalChunkReader,
-    CATALOG_NAME,
+    CATALOG_NAME, task_tracking
 };
 use pbs_datastore::backup_info::BackupInfo;
 use pbs_datastore::cached_chunk_reader::CachedChunkReader;
@@ -1590,6 +1590,30 @@ pub fn get_rrd_stats(
     )
 }
 
+#[api(
+    input: {
+        properties: {
+            store: {
+                schema: DATASTORE_SCHEMA,
+            },
+        },
+    },
+    access: {
+        permission: &Permission::Privilege(&["datastore", "{store}"], PRIV_DATASTORE_AUDIT, true),
+    },
+)]
+/// Read datastore stats
+pub fn get_active_operations(
+    store: String,
+    _param: Value,
+) -> Result<Value, Error> {
+    let active_operations = task_tracking::get_active_operations(&store)?;
+    Ok(json!({
+        "read": active_operations.read,
+        "write": active_operations.write,
+    }))
+}
+
 #[api(
     input: {
         properties: {
@@ -1947,6 +1971,11 @@ pub fn set_backup_owner(
 
 #[sortable]
 const DATASTORE_INFO_SUBDIRS: SubdirMap = &[
+    (
+        "active-operations",
+        &Router::new()
+            .get(&API_METHOD_GET_ACTIVE_OPERATIONS)
+    ),
     (
         "catalog",
         &Router::new()