Add options= config key, defaulting to "discard"

Supersedes #95
systemd · Oct 13, 2021 · 31d8579 · 31d8579
1 parent 771df17
commit 31d8579
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Showing 16 changed files with 84 additions and 12 deletions.
diff --git a/man/zram-generator.conf.md b/man/zram-generator.conf.md
@@ -104,6 +104,12 @@ Devices with the final size of *0* will be discarded.
 
   Also see systemd-makefs(8).
 
+* `options`=
+
+  Sets mount or swapon options. Availability depends on `fs-type`.
+
+  Defaults to *discard*.
+
 ## ENVIRONMENT VARIABLES
 
 Setting `ZRAM_GENERATOR_ROOT` during parsing will cause */proc/meminfo* to be read from *$ZRAM_GENERATOR_ROOT/proc/meminfo* instead,

diff --git a/src/config.rs b/src/config.rs
@@ -4,6 +4,7 @@ use anyhow::{anyhow, Context, Result};
 use ini::Ini;
 use liboverdrop::FragmentScanner;
 use log::{info, warn};
+use std::borrow::Cow;
 use std::cmp;
 use std::collections::{BTreeMap, HashMap};
 use std::fmt;
@@ -25,6 +26,7 @@ pub struct Device {
     pub mount_point: Option<PathBuf>, // when set, a mount unit will be created
     pub fs_type: Option<String>,      // useful mostly for mounts, None is the same
                                       // as "swap" when mount_point is not set
+    pub options: Cow<'static, str>,
 }
 
 impl Device {
@@ -39,6 +41,7 @@ impl Device {
             swap_priority: 100,
             mount_point: None,
             fs_type: None,
+            options: "discard".into(),
         }
     }
 
@@ -107,6 +110,7 @@ impl fmt::Display for Device {
             Some(alg) => f.write_str(alg)?,
             None => f.write_str("<default>")?,
         }
+        write!(f, " options={}", self.options)?;
         Ok(())
     }
 }
@@ -295,6 +299,10 @@ fn parse_line(dev: &mut Device, key: &str, value: &str) -> Result<()> {
             dev.fs_type = Some(value.to_string());
         }
 
+        "options" => {
+            dev.options = value.to_string().into();
+        }
+
         _ => {
             warn!("Unknown key {}, ignoring.", key);
         }

diff --git a/src/generator.rs b/src/generator.rs
@@ -215,9 +215,11 @@ After=systemd-zram-setup@{zram_device}.service
 [Swap]
 What=/dev/{zram_device}
 Priority={swap_priority}
+Options={options}
 ",
             zram_device = device.name,
-            swap_priority = device.swap_priority
+            swap_priority = device.swap_priority,
+            options = device.options.replace('%', "%%"),
         ),
     )?;
 
@@ -285,9 +287,11 @@ After=systemd-zram-setup@{zram_device}.service
 [Mount]
 What=/dev/{zram_device}
 Where={mount_point}
+Options={options}
 ",
             zram_device = device.name,
             mount_point = device.mount_point.as_ref().unwrap().to_str().unwrap(),
+            options = device.options.replace('%', "%%"),
         ),
     )?;
 

diff --git a/tests/01-basic/run.expected/units/dev-zram0.swap b/tests/01-basic/run.expected/units/dev-zram0.swap
@@ -9,3 +9,4 @@ After=systemd-zram-setup@zram0.service
 [Swap]
 What=/dev/zram0
 Priority=100
+Options=discard
diff --git a/tests/02-zstd/run.expected/units/dev-zram0.swap b/tests/02-zstd/run.expected/units/dev-zram0.swap
@@ -9,3 +9,4 @@ After=systemd-zram-setup@zram0.service
 [Swap]
 What=/dev/zram0
 Priority=100
+Options=discard
diff --git a/tests/04-dropins/etc/systemd/zram-generator.conf.d/04-drop4.conf b/tests/04-dropins/etc/systemd/zram-generator.conf.d/04-drop4.conf
@@ -1,3 +1,4 @@
 [zram2]
 zram-fraction=0.8
 swap-priority=200
+options=
diff --git a/tests/04-dropins/run.expected/units/dev-zram0.swap b/tests/04-dropins/run.expected/units/dev-zram0.swap
@@ -9,3 +9,4 @@ After=systemd-zram-setup@zram0.service
 [Swap]
 What=/dev/zram0
 Priority=100
+Options=discard
diff --git a/tests/04-dropins/run.expected/units/dev-zram2.swap b/tests/04-dropins/run.expected/units/dev-zram2.swap
@@ -9,3 +9,4 @@ After=systemd-zram-setup@zram2.service
 [Swap]
 What=/dev/zram2
 Priority=200
+Options=
diff --git a/tests/06-kernel-enabled/run.expected/units/dev-zram0.swap b/tests/06-kernel-enabled/run.expected/units/dev-zram0.swap
@@ -9,3 +9,4 @@ After=systemd-zram-setup@zram0.service
 [Swap]
 What=/dev/zram0
 Priority=100
+Options=discard
diff --git a/tests/07-mount-point/etc/systemd/zram-generator.conf b/tests/07-mount-point/etc/systemd/zram-generator.conf
@@ -1,3 +1,8 @@
 [zram11]
 mount-point = /var/compressed
 fs-type = ext4
+
+[zram12]
+mount-point = /var/folded
+fs-type = ext4
+options = discard,casefold
diff --git a/tests/07-mount-point/run.expected/units/local-fs.target.wants/var-folded.mount b/tests/07-mount-point/run.expected/units/local-fs.target.wants/var-folded.mount
@@ -0,0 +1 @@
+../var-folded.mount
diff --git a/.../07-mount-point/run.expected/units/systemd-zram-setup@zram12.service.d/bindsto-mount.conf b/.../07-mount-point/run.expected/units/systemd-zram-setup@zram12.service.d/bindsto-mount.conf
@@ -0,0 +1,4 @@
+# Automatically generated by "zram-generator"
+
+[Unit]
+BindsTo=var-folded.mount
diff --git a/tests/07-mount-point/run.expected/units/var-compressed.mount b/tests/07-mount-point/run.expected/units/var-compressed.mount
@@ -9,3 +9,4 @@ After=systemd-zram-setup@zram11.service
 [Mount]
 What=/dev/zram11
 Where=/var/compressed
+Options=discard
diff --git a/tests/07-mount-point/run.expected/units/var-folded.mount b/tests/07-mount-point/run.expected/units/var-folded.mount
@@ -0,0 +1,12 @@
+# Automatically generated by "/home/zbyszek/src/zram-generator/target/debug/zram-generator"
+
+[Unit]
+Description=Compressed Storage on /dev/zram12
+Documentation=man:zram-generator(8) man:zram-generator.conf(5)
+Requires=systemd-zram-setup@zram12.service
+After=systemd-zram-setup@zram12.service
+
+[Mount]
+What=/dev/zram12
+Where=/var/folded
+Options=discard,casefold
diff --git a/tests/test_cases.rs b/tests/test_cases.rs
@@ -50,6 +50,7 @@ fn test_generation(name: &str) -> Result<Vec<config::Device>> {
             assert!(d.is_swap());
             assert_eq!(d.host_memory_limit_mb, None);
             assert_eq!(d.zram_fraction, 0.5);
+            assert_eq!(d.options, "discard");
         }
 
         "02-zstd" => {
@@ -59,6 +60,7 @@ fn test_generation(name: &str) -> Result<Vec<config::Device>> {
             assert_eq!(d.host_memory_limit_mb.unwrap(), 2050);
             assert_eq!(d.zram_fraction, 0.75);
             assert_eq!(d.compression_algorithm.as_ref().unwrap(), "zstd");
+            assert_eq!(d.options, "discard");
         }
 
         "03-too-much-memory" => {
@@ -75,10 +77,12 @@ fn test_generation(name: &str) -> Result<Vec<config::Device>> {
                     "zram0" => {
                         assert_eq!(d.host_memory_limit_mb.unwrap(), 1235);
                         assert_eq!(d.zram_fraction, 0.5);
+                        assert_eq!(d.options, "discard");
                     }
                     "zram2" => {
                         assert!(d.host_memory_limit_mb.is_none());
                         assert_eq!(d.zram_fraction, 0.8);
+                        assert_eq!(d.options, "");
                     }
                     _ => panic!("Unexpected device {}", d),
                 }
@@ -95,20 +99,35 @@ fn test_generation(name: &str) -> Result<Vec<config::Device>> {
             assert!(d.is_swap());
             assert_eq!(d.host_memory_limit_mb, None);
             assert_eq!(d.zram_fraction, 0.5);
+            assert_eq!(d.options, "discard");
         }
 
         "07-mount-point" => {
-            assert_eq!(devices.len(), 1);
-            let d = devices.iter().next().unwrap();
-            assert!(!d.is_swap());
-            assert_eq!(d.host_memory_limit_mb, None);
-            assert_eq!(d.zram_fraction, 0.5);
-            assert_eq!(
-                d.mount_point.as_ref().unwrap(),
-                Path::new("/var/compressed")
-            );
-            assert_eq!(d.fs_type.as_ref().unwrap(), "ext4");
-            assert_eq!(d.effective_fs_type(), "ext4");
+            assert_eq!(devices.len(), 2);
+            for d in &devices {
+                assert!(!d.is_swap());
+                assert_eq!(d.host_memory_limit_mb, None);
+                assert_eq!(d.zram_fraction, 0.5);
+                assert_eq!(d.fs_type.as_ref().unwrap(), "ext4");
+                assert_eq!(d.effective_fs_type(), "ext4");
+                match &d.name[..] {
+                    "zram11" => {
+                        assert_eq!(
+                            d.mount_point.as_ref().unwrap(),
+                            Path::new("/var/compressed")
+                        );
+                        assert_eq!(d.options, "discard");
+                    }
+                    "zram12" => {
+                        assert_eq!(
+                            d.mount_point.as_ref().unwrap(),
+                            Path::new("/var/folded")
+                        );
+                        assert_eq!(d.options, "discard,casefold");
+                    }
+                    _ => panic!("Unexpected device {}", d),
+                }
+            }
         }
 
         "08-plain-device" => {
@@ -120,6 +139,7 @@ fn test_generation(name: &str) -> Result<Vec<config::Device>> {
             assert!(d.mount_point.is_none());
             assert_eq!(d.fs_type.as_ref().unwrap(), "ext2");
             assert_eq!(d.effective_fs_type(), "ext2");
+            assert_eq!(d.options, "discard");
         }
 
         _ => (),

diff --git a/zram-generator.conf.example b/zram-generator.conf.example
@@ -32,6 +32,11 @@ max-zram-size = 512
 # or leave unspecified to keep the kernel default.
 compression-algorithm = lzo-rle
 
+# By default, filesystems and swap areas are trimmed on-the-go
+# by setting "discard".
+# Setting this to the empty string clears the option.
+options =
+
 [zram1]
 # This section describes the settings for /dev/zram1.
 #