Ext2FS: Fix two bugs in block allocation:

1) Off-by-one in block allocation when block size != 1 KB

Due to a quirk in the on-disk layout of ext2, file systems with a block
size of 1 KB have block #1 as their first block, while all others start
on block #0.

2) We had no fallback mechanism when the preferred group was full

We now allocate blocks from the preferred block group as long as it's
possible, and fall back to a simple scan through all groups when the
preferred one is full.

1 files changed, 3 insertions, 1 deletions

diff --git a/Kernel/FileSystem/Ext2FileSystem.h b/Kernel/FileSystem/Ext2FileSystem.h
index 3cc7f19716..3c43f55680 100644
--- a/Kernel/FileSystem/Ext2FileSystem.h
+++ b/Kernel/FileSystem/Ext2FileSystem.h
@@ -98,8 +98,10 @@ private:
     virtual RefPtr<Inode> create_directory(InodeIdentifier parentInode, const String& name, mode_t, int& error) override;
     virtual RefPtr<Inode> get_inode(InodeIdentifier) const override;
 
+    BlockIndex first_block_index() const;
     InodeIndex allocate_inode(GroupIndex preferred_group, off_t expected_size);
-    Vector<BlockIndex> allocate_blocks(GroupIndex, int count);
+    Vector<BlockIndex> allocate_blocks(GroupIndex preferred_group_index, int count);
+    BlockIndex allocate_block(GroupIndex preferred_group_index);
     GroupIndex group_index_from_inode(InodeIndex) const;
     GroupIndex group_index_from_block_index(BlockIndex) const;