From 37d438b16c20cc3f97269f1c657f179ed2a1b156 Mon Sep 17 00:00:00 2001
From: Dmitry Kovba <dkovba@apple.com>
Date: Thu, 2 Apr 2026 22:16:03 -0700
Subject: [PATCH 1/2] Fix the last block group handling

---
 Sources/ContainerizationEXT4/EXT4+Formatter.swift | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/Sources/ContainerizationEXT4/EXT4+Formatter.swift b/Sources/ContainerizationEXT4/EXT4+Formatter.swift
index f386537a..60190484 100644
--- a/Sources/ContainerizationEXT4/EXT4+Formatter.swift
+++ b/Sources/ContainerizationEXT4/EXT4+Formatter.swift
@@ -805,13 +805,13 @@ extension EXT4 {
             }
             for group in blockGroupSize.blockGroups..<totalGroups.lo {
                 var blocksInGroup = UInt32(self.blocksPerGroup)
-                if group == totalGroups.lo {
+                if group == totalGroups.lo - 1 {
                     if UInt64(self.size / UInt64(self.blockSize)) < self.blocksPerGroup {
                         break
                     }
-                    blocksInGroup = UInt32((self.size / UInt64(self.blockSize)) % UInt64(self.blocksPerGroup))
-                    if blocksInGroup == 0 {
-                        break
+                    let lastGroupBlocks = UInt32((self.size / UInt64(self.blockSize)) % UInt64(self.blocksPerGroup))
+                    if lastGroupBlocks != 0 {
+                        blocksInGroup = lastGroupBlocks
                     }
                 }
                 let blockBitmapOffset = UInt64(group * self.blocksPerGroup + inodeTableSizePerGroup)
@@ -838,7 +838,7 @@ extension EXT4 {
                 totalBlocks += (inodeTableSizePerGroup + 2)
                 try self.seek(block: group * self.blocksPerGroup + inodeTableSizePerGroup)
 
-                if group == totalGroups.lo {
+                if group == totalGroups.lo - 1 && blocksInGroup != self.blocksPerGroup {
                     var blockBitmapLo: [UInt8] = .init(repeating: 0, count: Int(self.blocksPerGroup) / 8)
                     for i in blocksInGroup..<UInt32(self.blocksPerGroup) {
                         blockBitmapLo[Int(i) / 8] |= 1 << (i % 8)

From fdeb5b584948ccc6ed8af27b9eedfe822ef71e14 Mon Sep 17 00:00:00 2001
From: Dmitry Kovba <dkovba@apple.com>
Date: Fri, 3 Apr 2026 16:12:25 -0700
Subject: [PATCH 2/2] Remove not used code

---
 .../ContainerizationEXT4/EXT4+Formatter.swift | 25 +------------------
 1 file changed, 1 insertion(+), 24 deletions(-)

diff --git a/Sources/ContainerizationEXT4/EXT4+Formatter.swift b/Sources/ContainerizationEXT4/EXT4+Formatter.swift
index 60190484..8dec1f78 100644
--- a/Sources/ContainerizationEXT4/EXT4+Formatter.swift
+++ b/Sources/ContainerizationEXT4/EXT4+Formatter.swift
@@ -804,16 +804,7 @@ extension EXT4 {
                 inodeBitmap[Int(i) / 8] &= ~(1 << (i % 8))
             }
             for group in blockGroupSize.blockGroups..<totalGroups.lo {
-                var blocksInGroup = UInt32(self.blocksPerGroup)
-                if group == totalGroups.lo - 1 {
-                    if UInt64(self.size / UInt64(self.blockSize)) < self.blocksPerGroup {
-                        break
-                    }
-                    let lastGroupBlocks = UInt32((self.size / UInt64(self.blockSize)) % UInt64(self.blocksPerGroup))
-                    if lastGroupBlocks != 0 {
-                        blocksInGroup = lastGroupBlocks
-                    }
-                }
+                let blocksInGroup = UInt32(self.blocksPerGroup)
                 let blockBitmapOffset = UInt64(group * self.blocksPerGroup + inodeTableSizePerGroup)
                 let inodeBitmapOffset = UInt64(group * self.blocksPerGroup + inodeTableSizePerGroup + 1)
                 let inodeTableOffset = UInt64(self.blocksPerGroup) * group
@@ -837,20 +828,6 @@ extension EXT4 {
                     ))
                 totalBlocks += (inodeTableSizePerGroup + 2)
                 try self.seek(block: group * self.blocksPerGroup + inodeTableSizePerGroup)
-
-                if group == totalGroups.lo - 1 && blocksInGroup != self.blocksPerGroup {
-                    var blockBitmapLo: [UInt8] = .init(repeating: 0, count: Int(self.blocksPerGroup) / 8)
-                    for i in blocksInGroup..<UInt32(self.blocksPerGroup) {
-                        blockBitmapLo[Int(i) / 8] |= 1 << (i % 8)
-                    }
-                    for i in 0..<inodeTableSizePerGroup + 2 {
-                        blockBitmapLo[Int(i) / 8] |= 1 << (i % 8)
-                    }
-                    try self.handle.write(contentsOf: blockBitmapLo)
-                    try self.handle.write(contentsOf: inodeBitmap)
-                    continue
-                }
-
                 try self.handle.write(contentsOf: blockBitmap)
                 try self.handle.write(contentsOf: inodeBitmap)
             }