nydus-image: fix incorrect node offset in rafs v6 for hardlinks

Signed-off-by: yixiaojie <yixiaojie@bytedance.com>

src/bin/nydus-image/core/bootstrap.rs

@@ -168,6 +168,7 @@ impl Bootstrap {
             // Hardlink handle, all hardlink nodes' ino, nlink should be the same,
             // because the real_ino may be conflicted between different layers,
             // so we need to find hardlink node index list in the layer where the node is located.
+            let mut hardlink_v6_offset = 0;
             if let Some(indexes) = bootstrap_ctx.inode_map.get_mut(&(
                 child.node.layer_idx,
                 child.node.src_ino,
@@ -182,6 +183,8 @@ impl Bootstrap {
                     nodes[*idx as usize - 1].inode.set_nlink(nlink);
                 }
                 indexes.push(index);
+                // set offset for rafs v6 harlinks
+                hardlink_v6_offset = nodes[indexes[0] as usize - 1].offset;
             } else {
                 child.node.inode.set_ino(index);
                 child.node.inode.set_nlink(1);
@@ -195,7 +198,7 @@ impl Bootstrap {
             // update bootstrap_ctx.offset for rafs v6.
             if !child.node.is_dir() {
                 if ctx.fs_version.is_v6() {
-                    child.node.set_v6_offset(bootstrap_ctx);
+                    child.node.set_v6_offset(bootstrap_ctx, hardlink_v6_offset);
                 }
                 bootstrap_ctx.align_offset(EROFS_INODE_SLOT_SIZE as u64);
             }

src/bin/nydus-image/core/node.rs

@@ -1079,20 +1079,27 @@ impl Node {
     }
 
     /// Set node offset in bootstrap and return the next position.
-    pub(crate) fn set_v6_offset(&mut self, bootstrap_ctx: &mut BootstrapContext) {
+    pub(crate) fn set_v6_offset(
+        &mut self,
+        bootstrap_ctx: &mut BootstrapContext,
+        hardlink_v6_offset: u64,
+    ) {
         if self.is_reg() {
-            let size = self.size_with_xattr() as u64;
-            let unit = size_of::<RafsV6InodeChunkAddr>() as u64;
-
-            // We first try to allocate space from used blocks.
-            // If no available used block exists, we allocate sequentially.
-            let total_size = round_up(size, unit) + self.inode.child_count() as u64 * unit;
-            self.offset = bootstrap_ctx.allocate_available_block(total_size);
-            if self.offset == 0 {
-                self.offset = bootstrap_ctx.offset;
-                bootstrap_ctx.offset += size;
-                bootstrap_ctx.align_offset(unit);
-                bootstrap_ctx.offset += self.inode.child_count() as u64 * unit;
+            if hardlink_v6_offset == 0 {
+                let size = self.size_with_xattr() as u64;
+                let unit = size_of::<RafsV6InodeChunkAddr>() as u64;
+                // We first try to allocate space from used blocks.
+                // If no available used block exists, we allocate sequentially.
+                let total_size = round_up(size, unit) + self.inode.child_count() as u64 * unit;
+                self.offset = bootstrap_ctx.allocate_available_block(total_size);
+                if self.offset == 0 {
+                    self.offset = bootstrap_ctx.offset;
+                    bootstrap_ctx.offset += size;
+                    bootstrap_ctx.align_offset(unit);
+                    bootstrap_ctx.offset += self.inode.child_count() as u64 * unit;
+                }
+            } else {
+                self.offset = hardlink_v6_offset;
             }
             self.v6_datalayout = EROFS_INODE_CHUNK_BASED;
         } else if self.is_symlink() {
@@ -1897,7 +1904,7 @@ mod tests {
         // reg file.
         // "1" is used only for testing purpose, in practice
         // it's always aligned to 32 bytes.
-        node.set_v6_offset(&mut bootstrap_ctx);
+        node.set_v6_offset(&mut bootstrap_ctx, 0);
         assert_eq!(node.offset, 0);
         assert_eq!(node.v6_datalayout, EROFS_INODE_CHUNK_BASED);
         assert!(node.v6_compact_inode);