Ext2FS: Avoid a kmallocation every time we fetch an inode from disk.

luteresa · Feb 3, 2019 · 3a9c016 · 3a9c016
1 parent db2422d
commit 3a9c016
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Showing 2 changed files with 4 additions and 11 deletions.
diff --git a/Kernel/Ext2FileSystem.cpp b/Kernel/Ext2FileSystem.cpp
@@ -329,9 +329,8 @@ void Ext2FS::flush_block_group_descriptor_table()
  write_blocks(first_block_of_bgdt, blocks_to_write, m_cached_group_descriptor_table);
 }
 
-Ext2FSInode::Ext2FSInode(Ext2FS& fs, unsigned index, const ext2_inode& raw_inode)
+Ext2FSInode::Ext2FSInode(Ext2FS& fs, unsigned index)
  : Inode(fs, index)
- , m_raw_inode(raw_inode)
 {
 }
 
@@ -402,18 +401,12 @@ RetainPtr<Inode> Ext2FS::get_inode(InodeIdentifier inode) const
  if (!block)
  return { };
 
- // FIXME: Avoid this extra allocation, copy the raw inode directly into the Ext2FSInode metadata somehow.
- auto* e2inode = reinterpret_cast<ext2_inode*>(kmalloc(inode_size()));
- memcpy(e2inode, reinterpret_cast<ext2_inode*>(block.offset_pointer(offset)), inode_size());
- auto raw_inode = OwnPtr<ext2_inode>(e2inode);
- if (!raw_inode)
- return nullptr;
-
  LOCKER(m_inode_cache_lock);
  auto it = m_inode_cache.find(inode.index());
  if (it != m_inode_cache.end())
  return (*it).value;
- auto new_inode = adopt(*new Ext2FSInode(const_cast<Ext2FS&>(*this), inode.index(), *raw_inode));
+ auto new_inode = adopt(*new Ext2FSInode(const_cast<Ext2FS&>(*this), inode.index()));
+ memcpy(&new_inode->m_raw_inode, reinterpret_cast<ext2_inode*>(block.offset_pointer(offset)), inode_size());
  m_inode_cache.set(inode.index(), new_inode.copy_ref());
  return new_inode;
 }

diff --git a/Kernel/Ext2FileSystem.h b/Kernel/Ext2FileSystem.h
@@ -47,7 +47,7 @@ class Ext2FSInode final : public Inode {
 
  Ext2FS& fs();
  const Ext2FS& fs() const;
- Ext2FSInode(Ext2FS&, unsigned index, const ext2_inode&);
+ Ext2FSInode(Ext2FS&, unsigned index);
 
  mutable Vector<unsigned> m_block_list;
  mutable HashMap<String, unsigned> m_lookup_cache;