Fixed some issues

build.zig

@@ -74,6 +74,7 @@ pub fn build(b: *std.Build) !void {
 
     b.installArtifact(exe);
 
+    // Tests
     const lib_test = b.addTest(.{
         .name = "squashfs-test",
         .root_module = lib.root_module,

src/archive.zig

@@ -148,6 +148,8 @@ test "Basics" {
     var arc: Archive = try .init(alloc, io, archive_file);
     defer arc.deinit(io);
 
+    try std.testing.expectEqualDeep(arc.super, LinuxPATestCorrectSuperblock);
+
     var root_file = try arc.root(alloc, io);
     defer root_file.deinit();
 }
@@ -183,3 +185,43 @@ test "FullExtraction" {
 
     try arc.extract(alloc, io, TestFullExtractLocation, .default);
 }
+
+const LinuxPATestCorrectSuperblock: Superblock = .{
+    .magic = std.mem.readInt(u32, "hsqs", .little),
+    .inode_count = 2974,
+    .mod_time = 1632696724,
+    .block_size = 131072,
+    .frag_count = 264,
+    .compression = .zstd,
+    .block_log = 17,
+    .flags = .{
+        .inode_uncompressed = false,
+        .data_uncompressed = false,
+        .check = false,
+        .frag_uncompressed = false,
+        .frag_never = false,
+        .frag_always = false,
+        .de_dupe = true,
+        .exportable = true,
+        .xattr_uncompressed = false,
+        .xattr_never = false,
+        .compression_options = false,
+        .id_uncompressed = false,
+        ._ = 0,
+    },
+    .id_count = 1,
+    .ver_maj = 4,
+    .ver_min = 0,
+    .root_ref = .{
+        .block_offset = 1363,
+        .block_start = 29237,
+        ._ = 0,
+    },
+    .size = 106841744,
+    .id_start = 106841632,
+    .xattr_start = 106841720,
+    .inode_start = 106778274,
+    .dir_start = 106807998,
+    .frag_start = 106837747,
+    .export_start = 106841602,
+};

src/decomp_cache.zig

@@ -70,6 +70,7 @@ pub fn get(self: *DecompCache, io: Io, offset: u64, compressed_size: u32, max_si
         if (!self.alloc.resize(out, decomp_size)) {
             const new_out = try self.alloc.alloc(u8, decomp_size);
             @memcpy(new_out, out[0..decomp_size]);
+            self.alloc.free(out);
             out = new_out;
         } else {
             out.len = decomp_size;
@@ -77,8 +78,10 @@ pub fn get(self: *DecompCache, io: Io, offset: u64, compressed_size: u32, max_si
     }
     self.cur_mem += decomp_size;
 
-    cache.value_ptr.data = out;
+    cache.value_ptr.* = .{
-    _ = cache.value_ptr.usage.fetchAdd(1, .acquire);
+        .data = out,
+        .usage = .init(1),
+    };
     return out;
 }
 pub fn finished(self: *DecompCache, io: Io, offset: u64) void {

src/meta_rdr.zig

@@ -34,16 +34,22 @@ pub fn init(io: Io, cache: *DecompCache, start: u64) MetadataReader {
     };
 }
 pub fn deinit(self: *MetadataReader, io: Io) void {
+    if (self.cur_offset != 0)
         self.cache.finished(io, self.cur_offset);
 }
 
 fn advance(self: *MetadataReader) !void {
+    if (self.cur_offset != 0)
         self.cache.finished(self.io, self.cur_offset);
 
     self.interface.seek = 0;
     errdefer self.interface.end = 0;
 
     const hdr: Header = @bitCast(std.mem.readInt(u16, self.cache.map.memory[self.next_offset..][0..2], .little));
+    if (hdr.size > 8192) {
+        std.debug.print("Bad metadata header at {}: {}\n", .{ self.next_offset, hdr });
+        return error.ReadFailed;
+    }
     self.cur_offset = self.next_offset + 2;
     self.next_offset = self.cur_offset + hdr.size;