memfaultd 1.21.1 (Build 3112275)

Author: Memfault Inc.

CHANGELOG.md

@@ -6,6 +6,18 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to
 [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [1.21.1] - 2025-05-21
+
+This is a patch release that fixes an overflow issue with the recently added
+`diskstats/<disk>/bytes_written` metric.
+
+### Fixed
+
+- Fixed an issue with the `diskstats/<disk>/bytes_written` metric where it would
+  overflow when the diskstats counter wrapped. This would cause very large
+  readings to be sent. Whenever there is a potential overflow now the reading
+  will be discarded.
+
 ## [1.21.0] - 2025-05-08
 
 This release adds several new metrics for tracking flash wear, as well as a new
@@ -1360,3 +1372,5 @@ package][nginx-pid-report] for a discussion on the topic.
   https://github.com/memfault/memfault-linux-sdk/releases/tag/1.20.0-kirkstone
 [1.21.0]:
   https://github.com/memfault/memfault-linux-sdk/releases/tag/1.21.0-kirkstone
+[1.21.1]:
+  https://github.com/memfault/memfault-linux-sdk/releases/tag/1.21.1-kirkstone

Cargo.lock

@@ -1,3 +1,3 @@
-BUILD ID: 3088884
-GIT COMMIT: 1b9b610366
-VERSION: 1.21.0
+BUILD ID: 3112275
+GIT COMMIT: eaa113a284
+VERSION: 1.21.1

VERSION

@@ -1,6 +1,6 @@
 [package]
 name = "memfault-ssf"
-version = "1.21.0"
+version = "1.21.1"
 edition = "2021"
 description = "Supporting crate for the Memfault memfaultd embedded Linux agent"
 homepage = "https://github.com/memfault/memfaultd"

memfault-ssf/Cargo.toml

@@ -1,3 +1,3 @@
-BUILD ID: 3088884
-GIT COMMIT: 1b9b610366
-VERSION: 1.21.0
+BUILD ID: 3112275
+GIT COMMIT: eaa113a284
+VERSION: 1.21.1

memfault-ssf/VERSION

@@ -1,6 +1,6 @@
 [package]
 name = "memfaultc-sys"
-version = "1.21.0"
+version = "1.21.1"
 edition = "2021"
 autobins = false
 description = "Supporting crate for the Memfault memfaultd embedded Linux agent"

memfaultc-sys/Cargo.toml

@@ -1,3 +1,3 @@
-BUILD ID: 3088884
-GIT COMMIT: 1b9b610366
-VERSION: 1.21.0
+BUILD ID: 3112275
+GIT COMMIT: eaa113a284
+VERSION: 1.21.1

memfaultc-sys/VERSION

@@ -1,6 +1,6 @@
 [package]
 name = "memfaultd"
-version = "1.21.0"
+version = "1.21.1"
 edition = "2021"
 autobins = false
 rust-version = "1.72"
@@ -28,8 +28,8 @@ name= "mfw"
 path= "src/bin/mfw.rs"
 
 [dependencies]
-memfaultc-sys = { path= "../memfaultc-sys", version = "1.21.0" }
-ssf = { package = "memfault-ssf", path= "../memfault-ssf", version = "1.21.0" }
+memfaultc-sys = { path= "../memfaultc-sys", version = "1.21.1" }
+ssf = { package = "memfault-ssf", path= "../memfault-ssf", version = "1.21.1" }
 argh = "0.1.10"
 cfg-if = "1.0.0"
 chrono = { version = "0.4.23", features = ["serde"]}

memfaultd/Cargo.toml

@@ -1,3 +1,3 @@
-BUILD ID: 3088884
-GIT COMMIT: 1b9b610366
-VERSION: 1.21.0
+BUILD ID: 3112275
+GIT COMMIT: eaa113a284
+VERSION: 1.21.1

memfaultd/VERSION

@@ -9,7 +9,7 @@ use std::{
 };
 
 use eyre::{eyre, Result};
-use log::{debug, error};
+use log::{debug, error, warn};
 
 use crate::{
     metrics::{KeyedMetricReading, MetricStringKey},
@@ -70,19 +70,10 @@ where
             .map(|sectors_written| *sectors_written * SECTOR_SIZE);
 
         if let Some(bytes_written) = bytes_written {
-            if let Some(prev_bytes_written) = prev_bytes_reading.replace(bytes_written) {
-                let bytes_metric_key = MetricStringKey::from_str(&format!(
-                    "{}/{}/bytes_written",
-                    DISK_METRIC_NAMESPACE, disk_name
-                ))
-                .map_err(|e| eyre!("Invalid metric key: {}", e))?;
-                let bytes_since_last_reading = bytes_written - prev_bytes_written;
-                let bytes_metric = KeyedMetricReading::new_counter(
-                    bytes_metric_key,
-                    bytes_since_last_reading as f64,
-                );
-
-                metrics.push(bytes_metric);
+            match Self::calc_bytes_written_reading(bytes_written, prev_bytes_reading, disk_name) {
+                Ok(Some(reading)) => metrics.push(reading),
+                Ok(None) => {}
+                Err(e) => debug!("Failed to calculate bytes_written: {}", e),
             }
         }
 
@@ -155,6 +146,36 @@ where
 
         Ok(metrics)
     }
+
+    fn calc_bytes_written_reading(
+        cur_bytes_written: u64,
+        prev_bytes_written: &mut Option<u64>,
+        disk_name: &str,
+    ) -> Result<Option<KeyedMetricReading>> {
+        if let Some(prev_bytes_written) = prev_bytes_written.replace(cur_bytes_written) {
+            match cur_bytes_written.checked_sub(prev_bytes_written) {
+                Some(_) => {
+                    let bytes_metric_key = MetricStringKey::from_str(&format!(
+                        "{}/{}/bytes_written",
+                        DISK_METRIC_NAMESPACE, disk_name
+                    ))
+                    .map_err(|e| eyre!("Invalid metric key: {}", e))?;
+                    let bytes_since_last_reading = cur_bytes_written - prev_bytes_written;
+                    let bytes_metric = KeyedMetricReading::new_counter(
+                        bytes_metric_key,
+                        bytes_since_last_reading as f64,
+                    );
+                    Ok(Some(bytes_metric))
+                }
+                None => {
+                    warn!("bytes_written metric overflow, discarding reading");
+                    Ok(None)
+                }
+            }
+        } else {
+            Ok(None)
+        }
+    }
 }
 
 impl<M> SystemMetricFamilyCollector for DiskMetricsCollector<M>
@@ -323,6 +344,21 @@ mod test {
         });
     }
 
+    #[test]
+    fn test_calc_bytes_reading_overflow() {
+        let mut prev_bytes_reading = Some(1000);
+        let cur_bytes_written = 500;
+
+        let result = DiskMetricsCollector::<FakeMmc>::calc_bytes_written_reading(
+            cur_bytes_written,
+            &mut prev_bytes_reading,
+            "mmcblk0",
+        )
+        .unwrap();
+
+        assert!(result.is_none());
+    }
+
     #[rstest]
     #[case(DiskstatsMetricsConfig::Auto)]
     #[case(DiskstatsMetricsConfig::Devices(