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 @@ public:
     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 @@ public:
 
     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 @@ public:
     // 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;