DoAutomaticFreeDiskSpaceControl() introduced

mount.h

 // Copyright (c) 2009-2010 The Chromium OS Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Mount - class for managing cryptohome user keys and mounts.  In Chrome OS,
 // users are managed on top of a shared unix user, chronos.  When a user logs
 // in, cryptohome mounts their encrypted home directory to /home/chronos/user,
 // and Chrome does a profile switch to that directory.  All user data in their
 // home directory is transparently encrypted, providing protection against
 // offline theft.  On logout, the mount point is removed.
@@ skipping 22 matching lines @@
 // The default shared user (chronos)
 extern const std::string kDefaultSharedUser;
 // The default skeleton source (/etc/skel)
 extern const std::string kDefaultSkeletonSource;
 // The incognito user
 extern const std::string kIncognitoUser;
 // Directories that we intend to track (make pass-through in cryptohome vault)
 extern const char* kCacheDir;
 extern const char* kDownloadsDir;
 
+// Minimum free disk space on stateful_partition not to begin the cleanup
+const int64 kMinFreeSpace = 500 * 1LL << 20;  // 500M bytes
+
 
 // The Mount class handles mounting/unmounting of the user's cryptohome
 // directory as well as offline verification of the user's credentials against
 // the directory's crypto key.
 class Mount : public EntropySource {
  public:
   enum MountError {
     MOUNT_ERROR_NONE = 0,
     MOUNT_ERROR_FATAL = 1 << 0,
     MOUNT_ERROR_KEY_FAILURE = 1 << 1,
@@ skipping 84 matching lines @@
   // Parameters
   //   credentials - The Credentials representing the user
   //   is_new - True, if the cryptohome is being created and there is
   //            no need in migration
   virtual bool CreateTrackedSubdirectories(const Credentials& credentials,
                                            bool is_new) const;
 
   // Cleans (removes) content from unmounted tracked subdirectories
   virtual void CleanUnmountedTrackedSubdirectories() const;
 
+  // Checks free disk space and if it falls below minimum
+  // (kMinFreeSpace), performs cleanup
+  virtual void DoAutomaticFreeDiskSpaceControl() const;
+
   // Tests if the given credentials would decrypt the user's cryptohome key
   //
   // Parameters
   //   credentials - The Credentials to attempt to decrypt the key with
   virtual bool TestCredentials(const Credentials& credentials) const;
 
   // Migrages a user's vault key from one passkey to another
   //
   // Parameters
   //   credentials - The new Credentials for the user
@@ skipping 208 matching lines @@
   //   credentials - The Credentials representing the user
   std::string GetUserSaltFile(const Credentials& credentials) const;
 
   // Gets the user's vault directory
   //
   // Parameters
   //   credentials - The Credentials representing the user
   std::string GetUserVaultPath(const Credentials& credentials) const;
 
  private:
+  // Invokes given callback for every unmounted cryptohome
+  //
+  // Parameters
+  //   callback - routine to invoke.
+  typedef void (*CryptohomeCallback)(const FilePath&);
+  void DoForEveryUnmountedCryptohome(CryptohomeCallback callback) const;
+
   // Same as MountCryptohome but specifies if the cryptohome directory should be
   // recreated on a fatal error
   //
   // Parameters
   //   credentials - The Credentials representing the user
   //   mount_args - The options for the call to mount: whether to create the
   //                cryptohome if it doesn't exist and any tracked directories
   //                to create
   //   recreate_decrypt_fatal - Attempt to recreate the cryptohome directory on
   //                            a fatal error (for example, TPM was cleared)
@@ skipping 82 matching lines @@
   // Used to keep track of the current logged-in user
   scoped_ptr<UserSession> default_current_user_;
   UserSession* current_user_;
 
   DISALLOW_COPY_AND_ASSIGN(Mount);
 };
 
 }  // namespace cryptohome
 
 #endif  // CRYPTOHOME_MOUNT_H_