vfs: add modification time member to directory_service

Issue #1784.

repos/dde_rump/src/lib/vfs/rump/vfs_rump.cc

@@ -91,6 +91,8 @@ class Vfs::Rump_file_system : public File_system
 				Genode::error("Rump_vfs_handle::write() called");
 				return WRITE_ERR_INVALID;
 			}
+
+			virtual void update_modification_timestamp(Vfs::Timestamp) { }
 		};
 
 		class Rump_vfs_file_handle :
@@ -163,6 +165,17 @@ class Vfs::Rump_file_system : public File_system
 					out_count = n;
 					return WRITE_OK;
 				}
+
+				void update_modification_timestamp(Vfs::Timestamp time) override
+				{
+					struct timespec ts[2] = {
+						{ .tv_sec = 0,          .tv_nsec = 0 },
+						{ .tv_sec = time.value, .tv_nsec = 0 }
+					};
+
+					/* silently igore error */
+					rump_sys_futimens(_fd, (const timespec*)&ts);
+				}
 		};
 
 		class Rump_vfs_dir_handle : public Rump_vfs_handle
@@ -806,6 +819,12 @@ class Vfs::Rump_file_system : public File_system
 				_notify_files();
 			return SYNC_OK;
 		}
+
+		bool update_modification_timestamp(Vfs_handle *vfs_handle,
+		                                   Vfs::Timestamp ts)
+		{
+			return true;
+		}
 };
 
 

repos/os/include/vfs/dir_file_system.h

@@ -462,6 +462,7 @@ class Vfs::Dir_file_system : public File_system
 				out.gid    = 0;
 				out.inode  = 1;
 				out.device = (Genode::addr_t)this;
+				out.modification_time = { Vfs::Timestamp::INVALID };
 				return STAT_OK;
 			}
 

repos/os/include/vfs/directory_service.h

@@ -160,6 +160,7 @@ struct Vfs::Directory_service : Interface
 		unsigned      gid    = 0;
 		unsigned long inode  = 0;
 		unsigned long device = 0;
+		Timestamp     modification_time { Timestamp::INVALID };
 	};
 
 	enum Stat_result { STAT_ERR_NO_ENTRY = NUM_GENERAL_ERRORS,

repos/os/include/vfs/file_io_service.h

@@ -172,6 +172,20 @@ struct Vfs::File_io_service : Interface
 	virtual bool queue_sync(Vfs_handle *) { return true; }
 
 	virtual Sync_result complete_sync(Vfs_handle *) { return SYNC_OK; }
+
+	/***********************
+	 ** Modification time **
+	 ***********************/
+
+	/**
+	 * Update the modification time of a file
+	 *
+	 * \return true if update attempt was successful
+	 */
+	virtual bool update_modification_timestamp(Vfs_handle *, Vfs::Timestamp)
+	{
+		return true;
+	}
 };
 
 #endif /* _INCLUDE__VFS__FILE_IO_SERVICE_H_ */

repos/os/include/vfs/types.h

@@ -49,6 +49,12 @@ namespace Vfs {
 	using Genode::Interface;
 	using Genode::String;
 
+	struct Timestamp
+	{
+		static constexpr long long INVALID = (1LL << 63) + 1;
+		long long value;
+	};
+
 	typedef Genode::Path<MAX_PATH_LEN> Absolute_path;
 }
 

repos/os/src/lib/vfs/fs_file_system.h

@@ -225,6 +225,35 @@ class Vfs::Fs_file_system : public File_system
 
 				return result;
 			}
+
+			bool update_modification_timestamp(Vfs::Timestamp time)
+			{
+				::File_system::Session::Tx::Source &source = *_fs.tx();
+				using ::File_system::Packet_descriptor;
+
+				if (!source.ready_to_submit()) {
+					Genode::error(__func__, ":", __LINE__, " Insufficient_buffer");
+					return false;
+				}
+
+				try {
+					Packet_descriptor p(source.alloc_packet(0),
+					                    file_handle(),
+					                    Packet_descriptor::WRITE_TIMESTAMP,
+					                    ::File_system::Timestamp { .value = time.value });
+
+					/* pass packet to server side */
+					source.submit_packet(p);
+				} catch (::File_system::Session::Tx::Source::Packet_alloc_failed) {
+					Genode::error(__func__, ":", __LINE__, " Insufficient_buffer");
+					return false;
+				} catch (...) {
+					Genode::error("unhandled exception");
+					return false;
+				}
+
+				return true;
+			}
 		};
 
 		struct Fs_vfs_file_handle : Fs_vfs_handle
@@ -517,6 +546,10 @@ class Vfs::Fs_file_system : public File_system
 					case Packet_descriptor::CONTENT_CHANGED:
 						/* previously handled */
 						break;
+
+					case Packet_descriptor::WRITE_TIMESTAMP:
+						/* previously handled */
+						break;
 					}
 				};
 
@@ -535,6 +568,11 @@ class Vfs::Fs_file_system : public File_system
 					Lock::Guard guard(_lock);
 					source.release_packet(packet);
 				}
+
+				if (packet.operation() == Packet_descriptor::WRITE_TIMESTAMP) {
+					Lock::Guard guard(_lock);
+					source.release_packet(packet);
+				}
 			}
 		}
 
@@ -621,6 +659,7 @@ class Vfs::Fs_file_system : public File_system
 			out.gid = 0;
 			out.inode = status.inode;
 			out.device = (Genode::addr_t)this;
+			out.modification_time.value = status.modification_time.value;
 			return STAT_OK;
 		}
 
@@ -1011,6 +1050,15 @@ class Vfs::Fs_file_system : public File_system
 
 			return handle->complete_sync();
 		}
+
+		bool update_modification_timestamp(Vfs_handle *vfs_handle, Vfs::Timestamp time) override
+		{
+			Lock::Guard guard(_lock);
+
+			Fs_vfs_handle *handle = static_cast<Fs_vfs_handle *>(vfs_handle);
+
+			return handle->update_modification_timestamp(time);
+		}
 };
 
 #endif /* _INCLUDE__VFS__FS_FILE_SYSTEM_H_ */

repos/os/src/lib/vfs/ram_file_system.h

@@ -119,6 +119,8 @@ class Vfs_ram::Node : private Genode::Avl_node<Node>, private Genode::Lock
 			return ++inode_count;
 		}
 
+		Vfs::Timestamp _modification_time { Vfs::Timestamp::INVALID };
+
 	public:
 
 		using Lock::lock;
@@ -127,7 +129,10 @@ class Vfs_ram::Node : private Genode::Avl_node<Node>, private Genode::Lock
 		unsigned inode;
 
 		Node(char const *node_name)
-		: inode(_unique_inode()) { name(node_name); }
+		: inode(_unique_inode())
+		{
+			name(node_name);
+		}
 
 		virtual ~Node() { }
 
@@ -156,6 +161,14 @@ class Vfs_ram::Node : private Genode::Avl_node<Node>, private Genode::Lock
 		void unlink() { inode = 0; }
 		bool unlinked() const { return inode == 0; }
 
+		bool update_modification_timestamp(Vfs::Timestamp time)
+		{
+			_modification_time = time;
+			return true;
+		}
+
+		Vfs::Timestamp modification_time() const { return _modification_time; }
+
 		virtual size_t read(char*, size_t, file_size)
 		{
 			Genode::error("Vfs_ram::Node::read() called");
@@ -774,6 +787,7 @@ class Vfs::Ram_file_system : public Vfs::File_system
 			stat.size  = node->length();
 			stat.inode  = node->inode;
 			stat.device = (Genode::addr_t)this;
+			stat.modification_time = node->modification_time();
 
 			File *file = dynamic_cast<File *>(node);
 			if (file) {
@@ -1004,6 +1018,19 @@ class Vfs::Ram_file_system : public Vfs::File_system
 			return SYNC_OK;
 		}
 
+		bool update_modification_timestamp(Vfs_handle *vfs_handle, Vfs::Timestamp time) override
+		{
+			if ((vfs_handle->status_flags() & OPEN_MODE_ACCMODE) ==  OPEN_MODE_RDONLY)
+				return false;
+
+			Vfs_ram::Io_handle *handle =
+				static_cast<Vfs_ram::Io_handle *>(vfs_handle);
+			handle->modifying = true;
+
+			Vfs_ram::Node::Guard guard(&handle->node);
+			return handle->node.update_modification_timestamp(time);
+		}
+
 		/***************************
 		 ** File_system interface **
 		 ***************************/