Fix linux missing disk entries when some information are not available

src/unix/linux/disk.rs

@@ -465,9 +465,9 @@ impl DiskStat {
         // 3rd field
         let name = iter.nth(2).map(ToString::to_string)?;
         // 6th field
-        let sectors_read = iter.nth(2).and_then(|v| u64::from_str(v).ok())?;
+        let sectors_read = iter.nth(2).and_then(|v| u64::from_str(v).ok()).unwrap_or(0);
         // 10th field
-        let sectors_written = iter.nth(3).and_then(|v| u64::from_str(v).ok())?;
+        let sectors_written = iter.nth(3).and_then(|v| u64::from_str(v).ok()).unwrap_or(0);
         Some((
             name,
             Self {
@@ -583,4 +583,32 @@ mod test {
 
         assert_eq!(data, expected_data);
     }
+
+    #[test]
+    fn disk_entry_with_less_information() {
+        let file_content = "\
+ systemd-1      /efi autofs rw,relatime,fd=181,pgrp=1,timeout=120,minproto=5,maxproto=5,direct,pipe_ino=8311 0 0
+ /dev/nvme0n1p1 /efi vfat   rw,nosuid,nodev,noexec,relatime,nosymfollow,fmask=0077,dmask=0077                0 0
+";
+
+        let data = disk_stats_inner(file_content);
+        let expected_data: HashMap<String, DiskStat> = HashMap::from([
+            (
+                "autofs".to_string(),
+                DiskStat {
+                    sectors_read: 0,
+                    sectors_written: 0,
+                },
+            ),
+            (
+                "vfat".to_string(),
+                DiskStat {
+                    sectors_read: 0,
+                    sectors_written: 0,
+                },
+            ),
+        ]);
+
+        assert_eq!(data, expected_data);
+    }
 }