fix borrow issue in filetable logging

src/scheme/proc.rs

@@ -766,22 +766,23 @@ impl KernelScheme for ProcScheme {
                 kind: ContextHandle::AwaitingFiletableChange { new_ft },
                 context,
             } => {
-                let ft = new_ft.read(token.token());
-                let posix_count = ft.posix_fdtbl.iter().filter(|f| f.is_some()).count();
-                let upper_count = ft.upper_fdtbl.iter().filter(|f| f.is_some()).count();
+                let (posix_count, upper_count, upper_list) = {
+                    let ft = new_ft.read(token.token());
+                    let pc = ft.posix_fdtbl.iter().filter(|f| f.is_some()).count();
+                    let uc = ft.upper_fdtbl.iter().filter(|f| f.is_some()).count();
+                    let mut ul = String::new();
+                    for (i, f) in ft.upper_fdtbl.iter().enumerate() {
+                        if f.is_some() {
+                            ul.push_str(&format!(" {:x}", i));
+                        }
+                    }
+                    (pc, uc, ul)
+                };
                 let ctx_name = context.read(token.token()).name;
                 info!(
                     "AwaitingFiletableChange applied: ctx='{}' posix_fds={} upper_fds={}",
-                    ctx_name,
-                    posix_count,
-                    upper_count
+                    ctx_name, posix_count, upper_count
                 );
-                let mut upper_list = String::new();
-                for (i, f) in ft.upper_fdtbl.iter().enumerate() {
-                    if f.is_some() {
-                        upper_list.push_str(&format!(" {:x}", i));
-                    }
-                }
                 info!("upper FDs present:{}", upper_list);
                 context.write(token.token()).files = new_ft;
             }