VirtualFileSystem.h 4.9 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159
  1. #pragma once
  2. #include <AK/HashMap.h>
  3. #include <AK/OwnPtr.h>
  4. #include <AK/RetainPtr.h>
  5. #include <AK/String.h>
  6. #include <AK/Vector.h>
  7. #include <AK/Function.h>
  8. #include "InodeIdentifier.h"
  9. #include "InodeMetadata.h"
  10. #include "Limits.h"
  11. #include "FileSystem.h"
  12. #define O_RDONLY 0
  13. #define O_WRONLY 1
  14. #define O_RDWR 2
  15. #define O_CREAT 0100
  16. #define O_EXCL 0200
  17. #define O_NOCTTY 0400
  18. #define O_TRUNC 01000
  19. #define O_APPEND 02000
  20. #define O_NONBLOCK 04000
  21. #define O_DIRECTORY 00200000
  22. #define O_NOFOLLOW 00400000
  23. #define O_CLOEXEC 02000000
  24. #define O_NOFOLLOW_NOERROR 0x4000000
  25. class CharacterDevice;
  26. class FileDescriptor;
  27. inline constexpr dword encodedDevice(unsigned major, unsigned minor)
  28. {
  29. return (minor & 0xff) | (major << 8) | ((minor & ~0xff) << 12);
  30. }
  31. class VirtualFileSystem {
  32. AK_MAKE_ETERNAL
  33. friend ByteBuffer procfs$vnodes();
  34. public:
  35. static void initializeGlobals();
  36. class Mount {
  37. public:
  38. Mount(InodeIdentifier host, RetainPtr<FileSystem>&&);
  39. InodeIdentifier host() const { return m_host; }
  40. InodeIdentifier guest() const { return m_guest; }
  41. const FileSystem& fileSystem() const { return *m_fileSystem; }
  42. private:
  43. InodeIdentifier m_host;
  44. InodeIdentifier m_guest;
  45. RetainPtr<FileSystem> m_fileSystem;
  46. };
  47. struct Node {
  48. InodeIdentifier inode;
  49. const InodeMetadata& metadata() const;
  50. bool inUse() const { return inode.isValid() || m_characterDevice; }
  51. bool isCharacterDevice() const { return m_characterDevice; }
  52. CharacterDevice* characterDevice() { return m_characterDevice; }
  53. const CharacterDevice* characterDevice() const { return m_characterDevice; }
  54. void retain();
  55. void release();
  56. FileSystem* fileSystem() { return inode.fileSystem(); }
  57. const FileSystem* fileSystem() const { return inode.fileSystem(); }
  58. VirtualFileSystem* vfs() { return m_vfs; }
  59. const VirtualFileSystem* vfs() const { return m_vfs; }
  60. void* vmo() { return m_vmo; }
  61. void set_vmo(void* vmo) { m_vmo = vmo; }
  62. unsigned retain_count() const { return retainCount; }
  63. CoreInode* core_inode() { return m_core_inode.ptr(); }
  64. private:
  65. friend class VirtualFileSystem;
  66. VirtualFileSystem* m_vfs { nullptr };
  67. unsigned retainCount { 0 };
  68. CharacterDevice* m_characterDevice { nullptr };
  69. mutable InodeMetadata m_cachedMetadata;
  70. void* m_vmo { nullptr };
  71. RetainPtr<CoreInode> m_core_inode;
  72. };
  73. static VirtualFileSystem& the() PURE;
  74. VirtualFileSystem();
  75. ~VirtualFileSystem();
  76. bool isDirectory(const String& path, InodeIdentifier base = InodeIdentifier());
  77. void listDirectory(const String& path, InodeIdentifier base);
  78. void listDirectoryRecursively(const String& path, InodeIdentifier base);
  79. unsigned maxNodeCount() const { return m_maxNodeCount; }
  80. unsigned allocatedNodeCount() const { return m_maxNodeCount - m_nodeFreeList.size(); }
  81. Node* root() { return m_rootNode.ptr(); }
  82. const Node* root() const { return m_rootNode.ptr(); }
  83. bool mountRoot(RetainPtr<FileSystem>&&);
  84. bool mount(RetainPtr<FileSystem>&&, const String& path);
  85. RetainPtr<FileDescriptor> open(CharacterDevice&, int options);
  86. RetainPtr<FileDescriptor> open(const String& path, int& error, int options = 0, InodeIdentifier base = InodeIdentifier());
  87. RetainPtr<FileDescriptor> create(const String& path, InodeIdentifier base = InodeIdentifier());
  88. RetainPtr<FileDescriptor> mkdir(const String& path, InodeIdentifier base = InodeIdentifier());
  89. bool isRoot(InodeIdentifier) const;
  90. bool touch(const String&path);
  91. void registerCharacterDevice(CharacterDevice&);
  92. size_t mountCount() const { return m_mounts.size(); }
  93. void forEachMount(Function<void(const Mount&)>) const;
  94. String absolutePath(InodeIdentifier);
  95. private:
  96. friend class FileDescriptor;
  97. void enumerateDirectoryInode(InodeIdentifier, Function<bool(const FileSystem::DirectoryEntry&)>);
  98. InodeIdentifier resolvePath(const String& path, int& error, InodeIdentifier base = InodeIdentifier(), int options = 0);
  99. InodeIdentifier resolveSymbolicLink(InodeIdentifier base, InodeIdentifier symlinkInode, int& error);
  100. RetainPtr<Node> allocateNode();
  101. void freeNode(Node*);
  102. RetainPtr<Node> makeNode(InodeIdentifier);
  103. RetainPtr<Node> makeNode(CharacterDevice&);
  104. RetainPtr<Node> getOrCreateNode(InodeIdentifier);
  105. RetainPtr<Node> getOrCreateNode(CharacterDevice&);
  106. Mount* findMountForHost(InodeIdentifier);
  107. Mount* findMountForGuest(InodeIdentifier);
  108. HashMap<InodeIdentifier, Node*> m_inode2vnode;
  109. HashMap<dword, Node*> m_device2vnode;
  110. Vector<OwnPtr<Mount>> m_mounts;
  111. unsigned m_maxNodeCount { 0 };
  112. Node* m_nodes { nullptr };
  113. Vector<Node*> m_nodeFreeList;
  114. RetainPtr<Node> m_rootNode;
  115. HashMap<dword, CharacterDevice*> m_characterDevices;
  116. };