feat(ebpf): add support for XFS

Author: Molter73

fact-ebpf/src/bpf/inode.h

@@ -13,6 +13,8 @@
 #define BTRFS_SUPER_MAGIC 0x9123683E
 #define BTRFS_MAGIC 0x4D5F53665248425FULL
 
+#define XFS_SUPER_MAGIC 0x58465342
+
 /**
  * Retrieve the inode and device numbers and return them as a new key.
  *
@@ -35,6 +37,15 @@ __always_inline static inode_key_t inode_to_key(struct inode* inode) {
 
   unsigned long magic = inode->i_sb->s_magic;
   switch (magic) {
+    case XFS_SUPER_MAGIC: {
+      // XFS uses a major at bit 20 in kernel space, but puts it at bit
+      // 8 in userspace.
+      uint64_t major = inode->i_sb->s_dev >> 20;
+      uint64_t minor = inode->i_sb->s_dev & 0xFFFFF;
+      key.dev = (major << 8) | minor;
+      key.inode = inode->i_ino;
+      break;
+    }
     case BTRFS_MAGIC:
     case BTRFS_SUPER_MAGIC:
       if (bpf_core_type_exists(struct btrfs_inode)) {