allow sled agent to configure a swap device

illumos-utils/src/lib.rs

@@ -11,6 +11,7 @@ pub mod destructor;
 pub mod dkio;
 pub mod dladm;
 pub mod fstyp;
+pub mod libc;
 pub mod link;
 pub mod opte;
 pub mod running_zone;
@@ -71,6 +72,22 @@ mod inner {
             .join(" ")
     }
 
+    pub fn output_to_exec_error(
+        command: &std::process::Command,
+        output: &std::process::Output,
+    ) -> ExecutionError {
+        ExecutionError::CommandFailure(Box::new(CommandFailureInfo {
+            command: command
+                .get_args()
+                .map(|s| s.to_string_lossy().into())
+                .collect::<Vec<String>>()
+                .join(" "),
+            status: output.status,
+            stdout: String::from_utf8_lossy(&output.stdout).to_string(),
+            stderr: String::from_utf8_lossy(&output.stderr).to_string(),
+        }))
+    }
+
     // Helper function for starting the process and checking the
     // exit code result.
     pub fn execute(
@@ -81,18 +98,7 @@ mod inner {
         })?;
 
         if !output.status.success() {
-            return Err(ExecutionError::CommandFailure(Box::new(
-                CommandFailureInfo {
-                    command: command
-                        .get_args()
-                        .map(|s| s.to_string_lossy().into())
-                        .collect::<Vec<String>>()
-                        .join(" "),
-                    status: output.status,
-                    stdout: String::from_utf8_lossy(&output.stdout).to_string(),
-                    stderr: String::from_utf8_lossy(&output.stderr).to_string(),
-                },
-            )));
+            return Err(output_to_exec_error(command, &output));
         }
 
         Ok(output)

illumos-utils/src/libc.rs

@@ -0,0 +1,14 @@
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at https://mozilla.org/MPL/2.0/.
+
+//! Miscellaneous FFI wrapper functions for libc
+
+/// sysconf(3c)
+pub fn sysconf(arg: i32) -> std::io::Result<i64> {
+    let res = unsafe { libc::sysconf(arg) };
+    if res == -1 {
+        return Err(std::io::Error::last_os_error());
+    }
+    Ok(res)
+}

illumos-utils/src/zfs.rs

@@ -11,7 +11,7 @@ use std::fmt;
 
 pub const ZONE_ZFS_RAMDISK_DATASET_MOUNTPOINT: &str = "/zone";
 pub const ZONE_ZFS_RAMDISK_DATASET: &str = "rpool/zone";
-const ZFS: &str = "/usr/sbin/zfs";
+pub const ZFS: &str = "/usr/sbin/zfs";
 pub const KEYPATH_ROOT: &str = "/var/run/oxide/";
 
 /// Error returned by [`Zfs::list_datasets`].

sled-agent/Cargo.toml

@@ -34,6 +34,7 @@ internal-dns.workspace = true
 ipnetwork.workspace = true
 itertools.workspace = true
 key-manager.workspace = true
+libc.workspace = true
 macaddr.workspace = true
 nexus-client.workspace = true
 omicron-common.workspace = true
@@ -67,6 +68,7 @@ tokio = { workspace = true, features = [ "full" ] }
 tokio-tungstenite.workspace = true
 toml.workspace = true
 uuid.workspace = true
+zeroize.workspace = true
 zone.workspace = true
 
 [target.'cfg(target_os = "illumos")'.dependencies]

sled-agent/src/config.rs

@@ -51,6 +51,8 @@ pub struct Config {
     pub sidecar_revision: SidecarRevision,
     /// Optional percentage of DRAM to reserve for guest memory
     pub vmm_reservoir_percentage: Option<u8>,
+    /// Optional swap device size in GiB
+    pub swap_device_size_gb: Option<u32>,
     /// Optional VLAN ID to be used for tagging guest VNICs.
     pub vlan: Option<VlanID>,
     /// Optional list of zpools to be used as "discovered disks".

sled-agent/src/http_entrypoints.rs

@@ -201,7 +201,7 @@ async fn sled_role_get(
     rqctx: RequestContext<SledAgent>,
 ) -> Result<HttpResponseOk<SledRole>, HttpError> {
     let sa = rqctx.context();
-    Ok(HttpResponseOk(sa.get_role().await))
+    Ok(HttpResponseOk(sa.get_role()))
 }
 
 /// Initializes a CockroachDB cluster

sled-agent/src/lib.rs

@@ -33,6 +33,7 @@ mod sled_agent;
 mod smf_helper;
 pub(crate) mod storage;
 mod storage_manager;
+mod swap_device;
 mod updates;
 
 #[cfg(test)]

sled-agent/src/sled_agent.rs

@@ -49,6 +49,9 @@ pub enum Error {
     #[error("Configuration error: {0}")]
     Config(#[from] crate::config::ConfigError),
 
+    #[error("Error setting up swap device: {0}")]
+    SwapDevice(#[from] crate::swap_device::SwapDeviceError),
+
     #[error("Failed to acquire etherstub: {0}")]
     Etherstub(illumos_utils::ExecutionError),
 
@@ -230,6 +233,28 @@ impl SledAgent {
         ));
         info!(&log, "SledAgent::new(..) starting");
 
+        // Configure a swap device of the configured size before other system setup.
+        match config.swap_device_size_gb {
+            Some(sz) if sz > 0 => {
+                info!(log, "Requested swap device of size {} GiB", sz);
+                let boot_disk =
+                    storage.resources().boot_disk().await.ok_or_else(|| {
+                        crate::swap_device::SwapDeviceError::BootDiskNotFound
+                    })?;
+                crate::swap_device::ensure_swap_device(
+                    &parent_log,
+                    &boot_disk.1,
+                    sz,
+                )?;
+            }
+            Some(sz) if sz == 0 => {
+                panic!("Invalid requested swap device size of 0 GiB");
+            }
+            None | Some(_) => {
+                info!(log, "Not setting up swap device: not configured");
+            }
+        }
+
         let etherstub = Dladm::ensure_etherstub(
             illumos_utils::dladm::UNDERLAY_ETHERSTUB_NAME,
         )
@@ -609,7 +634,7 @@ impl SledAgent {
     }
 
     /// Returns whether or not the sled believes itself to be a scrimlet
-    pub async fn get_role(&self) -> SledRole {
+    pub fn get_role(&self) -> SledRole {
         if self.inner.hardware.is_scrimlet() {
             SledRole::Scrimlet
         } else {