Fix how we configure compression parameters

Closes: #215

Author: nabijaczleweli

man/zram-generator.conf.md

@@ -79,8 +79,8 @@ Devices with the final size of *0* will be discarded.
   If unset, none will be configured and the kernel's default will be used.<br />
   If more than one is given, and recompression is enabled in the kernel, subsequent ones will be set as the recompression algorithms, with decreasing priority.
 
-  If a compression algorithm is suffixed with a parenthesised comma-separated list of parameters, those are given to `.../algorithm_params` (and `.../recompress`).
-  A parenthesised parameter list *without* a compression algorithm is set as the global recompression parameters.
+  If a compression algorithm is suffixed with a parenthesised comma-separated list of parameters, those are given to `.../algorithm_params`.
+  A parenthesised parameter list *without* a compression algorithm is set as the global recompression parameters (`.../recompress`).
 
 * `writeback-device`=
 

src/setup.rs

@@ -35,39 +35,23 @@ pub fn run_device_setup(device: Option<Device>, device_name: &str) -> Result<()>
         .iter()
         .enumerate()
     {
-        let params = if params.is_empty() {
-            None
-        } else {
-            Some(params)
-        };
-        let (path, data, add_pathdata) = if prio == 0 {
+        let (path, data) = if prio == 0 {
             (
                 device_sysfs_path.join("comp_algorithm"),
                 algo,
-                params.as_ref().map(|p| {
-                    (
-                        device_sysfs_path.join("algorithm_params"),
-                        format!("algo={} {}", algo, p),
-                    )
-                }),
             )
         } else {
             (
                 device_sysfs_path.join("recomp_algorithm"),
                 &format!("algo={} priority={}", algo, prio),
-                params.as_ref().map(|p| {
-                    (
-                        device_sysfs_path.join("recompress"),
-                        format!("{} priority={}", p, prio),
-                    )
-                }),
             )
         };
 
         match fs::write(&path, data) {
             Ok(_) => {
-                if let Some((add_path, add_data)) = add_pathdata {
-                    match fs::write(add_path, &add_data) {
+                if !params.is_empty() {
+                    let add_data = format!("priority={} {}", prio, params);
+                    match fs::write(device_sysfs_path.join("algorithm_params"), &add_data) {
                         Ok(_) => {}
                         Err(err) => {
                             warn!(