feat: Add used_clusters tracking in AFS and update disk info retrieval

7 files changed, 31 insertions, 44 deletions

diff --git a/mirai/fs/afs/afs.zig b/mirai/fs/afs/afs.zig
index 4f33ade..a7217a2 100644
--- a/mirai/fs/afs/afs.zig
+++ b/mirai/fs/afs/afs.zig
@@ -26,6 +26,7 @@ pub fn AFS(comptime BlockDeviceType: type) type {
         alloc_table_sector: u32,
         alloc_table_size: u32,
         data_area_sector: u32,
+        used_clusters: u32,
         parent_cache: [fs.PARENT_CACHE_SIZE]types.ParentCacheEntry,
         parent_cache_count: usize,
 
@@ -57,6 +58,7 @@ pub fn AFS(comptime BlockDeviceType: type) type {
                 .alloc_table_sector = boot.alloc_table_sector,
                 .alloc_table_size = boot.alloc_table_size,
                 .data_area_sector = boot.data_area_sector,
+                .used_clusters = boot.used_clusters,
                 .parent_cache = undefined,
                 .parent_cache_count = 0,
             };
@@ -68,6 +70,16 @@ pub fn AFS(comptime BlockDeviceType: type) type {
             return cluster_ops.to_lba(self, cluster);
         }
 
+        pub fn increment_used(self: *Self) void {
+            self.used_clusters += 1;
+        }
+
+        pub fn decrement_used(self: *Self) void {
+            if (self.used_clusters > 0) {
+                self.used_clusters -= 1;
+            }
+        }
+
         // Cache operations
 
         pub fn get_parent_cluster(self: *Self, cluster: u32) ?u32 {
diff --git a/mirai/fs/afs/cluster.zig b/mirai/fs/afs/cluster.zig
index 89fcaf2..50f3ca2 100644
--- a/mirai/fs/afs/cluster.zig
+++ b/mirai/fs/afs/cluster.zig
@@ -56,9 +56,15 @@ pub fn allocate(afs: anytype) !u32 {
 
         if (endian.read_u32_le(sector[offset..]) == fs.CLUSTER_FREE) {
             try write_alloc(afs, cluster, fs.CLUSTER_END);
+            afs.increment_used();
             return cluster;
         }
     }
 
     return error.DiskFull;
 }
+
+pub fn free(afs: anytype, cluster: u32) !void {
+    try write_alloc(afs, cluster, fs.CLUSTER_FREE);
+    afs.decrement_used();
+}
diff --git a/mirai/fs/afs/info.zig b/mirai/fs/afs/info.zig
index 8c3df0a..8d9889e 100644
--- a/mirai/fs/afs/info.zig
+++ b/mirai/fs/afs/info.zig
@@ -1,49 +1,15 @@
 //! AFS disk info operations
 
-const endian = @import("../../utils/bytes/endian.zig");
 const fs = @import("../../common/constants/fs.zig");
 const types = @import("types.zig");
 
 pub fn get_disk_info(afs: anytype) types.DiskInfo {
     const cluster_size: u64 = @as(u64, afs.sectors_per_cluster) * fs.SECTOR_SIZE;
     const total = @as(u64, afs.total_clusters) * cluster_size;
-
-    // Count used clusters by scanning allocation table in bulk
-    var used_clusters: u64 = 0;
-    var sector_buf: [fs.SECTOR_SIZE]u8 align(fs.SECTOR_ALIGN) = undefined;
-
-    const entries_per_sector = fs.SECTOR_SIZE / 4; // 4 bytes per entry
-    const table_sectors = (afs.total_clusters + entries_per_sector - 1) / entries_per_sector;
-
-    var sector_idx: u32 = 0;
-    while (sector_idx < table_sectors) : (sector_idx += 1) {
-        const table_sector = afs.partition_offset + afs.alloc_table_sector + sector_idx;
-
-        if (!afs.device.read_sector(table_sector, &sector_buf)) {
-            break;
-        }
-
-        // Count non-free entries in this sector
-        var entry_idx: usize = 0;
-        while (entry_idx < entries_per_sector) : (entry_idx += 1) {
-            const cluster = sector_idx * entries_per_sector + entry_idx;
-            if (cluster >= afs.total_clusters) break;
-            if (cluster < fs.CLUSTER_MIN) {
-                entry_idx += 1;
-                continue;
-            }
-
-            const offset = entry_idx * 4;
-            const value = endian.read_u32_le(sector_buf[offset..]);
-
-            if (value != fs.CLUSTER_FREE) {
-                used_clusters += 1;
-            }
-        }
-    }
+    const used = @as(u64, afs.used_clusters) * cluster_size;
 
     return types.DiskInfo{
         .total_bytes = total,
-        .used_bytes = used_clusters * cluster_size,
+        .used_bytes = used,
     };
 }
diff --git a/mirai/fs/afs/types.zig b/mirai/fs/afs/types.zig
index 2ee5352..77ad084 100644
--- a/mirai/fs/afs/types.zig
+++ b/mirai/fs/afs/types.zig
@@ -12,7 +12,8 @@ pub const BootSector = extern struct {
     alloc_table_sector: u32,
     alloc_table_size: u32,
     data_area_sector: u32,
-    reserved: [466]u8,
+    used_clusters: u32,
+    reserved: [462]u8,
     boot_signature: u16,
 };
 
diff --git a/mirai/invocations/os/diskinfo.zig b/mirai/invocations/os/diskinfo.zig
index 7844e9b..62c73dc 100644
--- a/mirai/invocations/os/diskinfo.zig
+++ b/mirai/invocations/os/diskinfo.zig
@@ -2,7 +2,6 @@
 
 const afs = @import("../../fs/afs/afs.zig");
 const ahci = @import("../../drivers/ahci/ahci.zig");
-const cpu = @import("../../asm/cpu.zig");
 const handler = @import("../handler.zig");
 const result = @import("../../utils/types/result.zig");
 
@@ -17,11 +16,7 @@ pub fn invoke(ctx: *handler.InvocationContext) void {
     const used_ptr: *u64 = @ptrFromInt(ctx.rsi);
 
     if (fs_instance) |fs| {
-        // Disable interrupts during disk read to prevent race conditions
-        cpu.disable_interrupts();
         const info = fs.get_disk_info();
-        cpu.enable_interrupts();
-
         total_ptr.* = info.total_bytes;
         used_ptr.* = info.used_bytes;
         result.set_ok(ctx);
diff --git a/toolchain/grub-afs/afs.c b/toolchain/grub-afs/afs.c
index 536c189..5bf578b 100644
--- a/toolchain/grub-afs/afs.c
+++ b/toolchain/grub-afs/afs.c
@@ -22,7 +22,8 @@ struct afs_boot_sector
   grub_uint32_t alloc_table_sector;
   grub_uint32_t alloc_table_size;
   grub_uint32_t data_area_sector;
-  grub_uint8_t reserved[466];
+  grub_uint32_t used_clusters;
+  grub_uint8_t reserved[462];
   grub_uint16_t boot_signature;
 } GRUB_PACKED;
 
diff --git a/toolchain/mkafsdisk/main.zig b/toolchain/mkafsdisk/main.zig
index ab932f0..2312e17 100644
--- a/toolchain/mkafsdisk/main.zig
+++ b/toolchain/mkafsdisk/main.zig
@@ -14,7 +14,8 @@ const AFSBootSector = extern struct {
     alloc_table_sector: u32,
     alloc_table_size: u32,
     data_area_sector: u32,
-    reserved: [466]u8,
+    used_clusters: u32,
+    reserved: [462]u8,
     boot_signature: u16,
 };
 
@@ -629,6 +630,7 @@ fn createAFS(allocator: mem.Allocator, file: fs.File, source_dir: []const u8, pa
     boot.alloc_table_sector = 1;
     boot.alloc_table_size = alloc_table_size;
     boot.data_area_sector = data_area_start;
+    boot.used_clusters = 0;
     boot.boot_signature = 0xAA55;
 
     try file.seekTo(@as(u64, partition_start) * 512);
@@ -642,6 +644,10 @@ fn createAFS(allocator: mem.Allocator, file: fs.File, source_dir: []const u8, pa
     try copyDirectoryAFS(allocator, file, source_dir, partition_start, data_area_start, cluster_alloc, root_cluster);
 
     try writeAllocationTable(file, partition_start, alloc_table_size, cluster_alloc);
+    // Update used_clusters in boot sector
+    boot.used_clusters = cluster_alloc.next_cluster - 2; // Subtract reserved clusters
+    try file.seekTo(@as(u64, partition_start) * 512);
+    try file.writeAll(mem.asBytes(&boot));
     std.debug.print("  AFS partition created\n", .{});
 }