Kernel: Remove some unnecessary indirection in InodeFile::mmap()

InodeFile now directly calls Process::allocate_region_with_vmobject()
instead of taking an awkward detour via a special Region constructor.

Kernel/FileSystem/InodeFile.cpp

@@ -29,6 +29,7 @@
 #include <Kernel/FileSystem/InodeFile.h>
 #include <Kernel/FileSystem/VirtualFileSystem.h>
 #include <Kernel/Process.h>
+#include <Kernel/VM/SharedInodeVMObject.h>
 
 namespace Kernel {
 
@@ -63,7 +64,7 @@ KResultOr<Region*> InodeFile::mmap(Process& process, FileDescription& descriptio
 {
  ASSERT(offset == 0);
  // FIXME: If PROT_EXEC, check that the underlying file system isn't mounted noexec.
- auto* region = process.allocate_file_backed_region(preferred_vaddr, size, inode(), description.absolute_path(), prot);
+ auto* region = process.allocate_region_with_vmobject(preferred_vaddr, size, SharedInodeVMObject::create_with_inode(inode()), offset, description.absolute_path(), prot);
  if (!region)
  return KResult(-ENOMEM);
  return region;

Kernel/Process.cpp

@@ -66,9 +66,9 @@
 #include <Kernel/TTY/MasterPTY.h>
 #include <Kernel/TTY/TTY.h>
 #include <Kernel/Thread.h>
-#include <Kernel/VM/SharedInodeVMObject.h>
 #include <Kernel/VM/PageDirectory.h>
 #include <Kernel/VM/PurgeableVMObject.h>
+#include <Kernel/VM/SharedInodeVMObject.h>
 #include <LibBareMetal/IO.h>
 #include <LibBareMetal/Output/Console.h>
 #include <LibBareMetal/StdLib.h>
@@ -205,16 +205,6 @@ Region* Process::allocate_region(VirtualAddress vaddr, size_t size, const String
  return allocate_region(range, name, prot, commit);
 }
 
-Region* Process::allocate_file_backed_region(VirtualAddress vaddr, size_t size, NonnullRefPtr<Inode> inode, const String& name, int prot)
-{
- auto range = allocate_range(vaddr, size);
- if (!range.is_valid())
- return nullptr;
- auto& region = add_region(Region::create_user_accessible(range, inode, name, prot_to_region_access_flags(prot)));
- region.map(page_directory());
- return &region;
-}
-
 Region* Process::allocate_region_with_vmobject(const Range& range, NonnullRefPtr<VMObject> vmobject, size_t offset_in_vmobject, const String& name, int prot, bool user_accessible)
 {
  ASSERT(range.is_valid());
@@ -241,7 +231,6 @@ Region* Process::allocate_region_with_vmobject(const Range& range, NonnullRefPtr
  return region;
 }
 
-
 Region* Process::allocate_region_with_vmobject(VirtualAddress vaddr, size_t size, NonnullRefPtr<VMObject> vmobject, size_t offset_in_vmobject, const String& name, int prot, bool user_accessible)
 {
  auto range = allocate_range(vaddr, size);

Kernel/Process.h

@@ -367,7 +367,6 @@ class Process : public InlineLinkedListNode<Process> {
  bool is_superuser() const { return m_euid == 0; }
 
  Region* allocate_region_with_vmobject(VirtualAddress, size_t, NonnullRefPtr<VMObject>, size_t offset_in_vmobject, const String& name, int prot, bool user_accessible = true);
- Region* allocate_file_backed_region(VirtualAddress, size_t, NonnullRefPtr<Inode>, const String& name, int prot);
  Region* allocate_region(VirtualAddress, size_t, const String& name, int prot = PROT_READ | PROT_WRITE, bool commit = true);
  Region* allocate_region_with_vmobject(const Range&, NonnullRefPtr<VMObject>, size_t offset_in_vmobject, const String& name, int prot, bool user_accessible = true);
  Region* allocate_region(const Range&, const String& name, int prot = PROT_READ | PROT_WRITE, bool commit = true);

Kernel/VM/Region.cpp

@@ -48,16 +48,6 @@ Region::Region(const Range& range, const String& name, u8 access, bool cacheable
  MM.register_region(*this);
 }
 
-Region::Region(const Range& range, NonnullRefPtr<Inode> inode, const String& name, u8 access, bool cacheable)
- : m_range(range)
- , m_vmobject(SharedInodeVMObject::create_with_inode(*inode))
- , m_name(name)
- , m_access(access)
- , m_cacheable(cacheable)
-{
- MM.register_region(*this);
-}
-
 Region::Region(const Range& range, NonnullRefPtr<VMObject> vmobject, size_t offset_in_vmobject, const String& name, u8 access, bool cacheable)
  : m_range(range)
  , m_offset_in_vmobject(offset_in_vmobject)
@@ -206,13 +196,6 @@ NonnullOwnPtr<Region> Region::create_user_accessible(const Range& range, Nonnull
  return region;
 }
 
-NonnullOwnPtr<Region> Region::create_user_accessible(const Range& range, NonnullRefPtr<Inode> inode, const StringView& name, u8 access, bool cacheable)
-{
- auto region = make<Region>(range, move(inode), name, access, cacheable);
- region->m_user_accessible = true;
- return region;
-}
-
 NonnullOwnPtr<Region> Region::create_kernel_only(const Range& range, NonnullRefPtr<VMObject> vmobject, size_t offset_in_vmobject, const StringView& name, u8 access, bool cacheable)
 {
  auto region = make<Region>(range, move(vmobject), offset_in_vmobject, name, access, cacheable);

Kernel/VM/Region.h

@@ -57,7 +57,6 @@ class Region final
 
  static NonnullOwnPtr<Region> create_user_accessible(const Range&, const StringView& name, u8 access, bool cacheable = true);
  static NonnullOwnPtr<Region> create_user_accessible(const Range&, NonnullRefPtr<VMObject>, size_t offset_in_vmobject, const StringView& name, u8 access, bool cacheable = true);
- static NonnullOwnPtr<Region> create_user_accessible(const Range&, NonnullRefPtr<Inode>, const StringView& name, u8 access, bool cacheable = true);
  static NonnullOwnPtr<Region> create_kernel_only(const Range&, const StringView& name, u8 access, bool cacheable = true);
  static NonnullOwnPtr<Region> create_kernel_only(const Range&, NonnullRefPtr<VMObject>, size_t offset_in_vmobject, const StringView& name, u8 access, bool cacheable = true);
 
@@ -163,7 +162,6 @@ class Region final
  // NOTE: These are public so we can make<> them.
  Region(const Range&, const String&, u8 access, bool cacheable);
  Region(const Range&, NonnullRefPtr<VMObject>, size_t offset_in_vmobject, const String&, u8 access, bool cacheable);
- Region(const Range&, NonnullRefPtr<Inode>, const String&, u8 access, bool cacheable);
 
 private:
  Bitmap& ensure_cow_map() const;