Merge pull request #11466 from lifupan/blockfile

runtime-rs: add the blockfile based rootfs support

src/runtime-rs/crates/resource/src/rootfs/block_rootfs.rs

@@ -25,6 +25,8 @@ use oci_spec::runtime as oci;
 use std::fs;
 use tokio::sync::RwLock;
 
+const BLOCKFILE_ROOTFS_FLAG: &str = "loop";
+
 pub(crate) struct BlockRootfs {
     guest_path: String,
     device_id: String,
@@ -53,6 +55,7 @@ impl BlockRootfs {
             major: stat::major(dev_id) as i64,
             minor: stat::minor(dev_id) as i64,
             driver_option: block_driver.clone(),
+            path_on_host: rootfs.source.clone(),
             ..Default::default()
         };
 
@@ -133,15 +136,40 @@ impl Rootfs for BlockRootfs {
     }
 }
 
-pub(crate) fn is_block_rootfs(file: &str) -> Option<u64> {
+pub(crate) fn is_block_rootfs(m: &Mount) -> Option<(u64, Mount)> {
-    if file.is_empty() {
+    if m.source.is_empty() {
         return None;
     }
-    match stat::stat(file) {
+
+    match stat::stat(m.source.as_str()) {
         Ok(fstat) => {
             if SFlag::from_bits_truncate(fstat.st_mode) == SFlag::S_IFBLK {
                 let dev_id = fstat.st_rdev;
-                return Some(dev_id);
+                let mut volume = m.clone();
+
+                //clear the volume resource thus the block device will use the dev_id
+                //to find the device's host path;
+                volume.source = String::new();
+                return Some((dev_id, m.clone()));
+            }
+
+            if SFlag::from_bits_truncate(fstat.st_mode) == SFlag::S_IFREG
+                && m.options.contains(&BLOCKFILE_ROOTFS_FLAG.to_string())
+            {
+                //use the block file's inode as the device id, which can make sure it's unique.
+                let dev_id = fstat.st_ino;
+                let options = m
+                    .options
+                    .clone()
+                    .into_iter()
+                    .filter(|o| !o.eq(BLOCKFILE_ROOTFS_FLAG))
+                    .collect();
+
+                //discard the blockfile rootfs's mount option "loop"
+                let mut volume = m.clone();
+                volume.options = options;
+
+                return Some((dev_id, volume));
             }
         }
         Err(_) => return None,

src/runtime-rs/crates/resource/src/rootfs/mod.rs

@@ -105,11 +105,11 @@ impl RootFsResource {
                     return Ok(virtual_volume);
                 }
 
-                let rootfs = if let Some(dev_id) = is_block_rootfs(&layer.source) {
+                let rootfs = if let Some((dev_id, layer)) = is_block_rootfs(layer) {
                     // handle block rootfs
                     info!(sl!(), "block device: {}", dev_id);
                     let block_rootfs: Arc<dyn Rootfs> = Arc::new(
-                        block_rootfs::BlockRootfs::new(device_manager, sid, cid, dev_id, layer)
+                        block_rootfs::BlockRootfs::new(device_manager, sid, cid, dev_id, &layer)
                             .await
                             .context("new block rootfs")?,
                     );