Proper zig project organization

src/superblock.zig

@@ -0,0 +1,54 @@
+const math = @import("std").math;
+const InodeRef = @import("inode.zig").InodeRef;
+const CompressionType = @import("decompress.zig").CompressionType;
+
+pub const SuperblockError = error{
+    InvalidMagic,
+    InvalidLog,
+    InvalidVersion,
+};
+
+pub const Superblock = packed struct {
+    magic: u32,
+    count: u32,
+    mod_time: u32,
+    block_size: u32,
+    frags: u32,
+    comp: CompressionType,
+    block_log: u16,
+    flags: packed struct {
+        inode_uncomp: bool,
+        data_uncomp: bool,
+        _unused: bool,
+        frag_uncomp: bool,
+        frag_always: bool,
+        data_dedupe: bool,
+        export_table: bool,
+        xattr_uncomp: bool,
+        no_xattr: bool,
+        comp_options: bool,
+        id_uncomp: bool,
+        _padding: u5,
+    },
+    id_count: u16,
+    ver_maj: u16,
+    ver_min: u16,
+    root_inode: InodeRef,
+    size: u64,
+    id_table: u64,
+    xattr_table: u64,
+    inode_table: u64,
+    dir_table: u64,
+    frag_table: u64,
+    export_table: u64,
+
+    pub fn valid(self: Superblock) SuperblockError!void {
+        if (self.magic != 0x73717368) {
+            return SuperblockError.InvalidMagic;
+        } else if (self.block_log != math.log2(self.block_size)) {
+            return SuperblockError.InvalidLog;
+        } else if (self.ver_maj != 4 or self.ver_min != 0) {
+            return SuperblockError.InvalidVersion;
+        }
+    }
+};