mirror of
https://github.com/genodelabs/genode.git
synced 2024-12-26 00:41:08 +00:00
fca8994584
This patch extends the file-system interface with the ability to monitor changes of files or directories. The new 'File_system::sigh' function can be used to install a signal handler for an open node. The 'ram_fs' server has been enhanced to support the new interface. So any file or directory changes can now be observed by 'ram_fs' clients. Fixes #607
344 lines
9.6 KiB
C++
344 lines
9.6 KiB
C++
/*
|
|
* \brief File-system session interface
|
|
* \author Norman Feske
|
|
* \date 2012-04-05
|
|
*/
|
|
|
|
/*
|
|
* Copyright (C) 2012-2013 Genode Labs GmbH
|
|
*
|
|
* This file is part of the Genode OS framework, which is distributed
|
|
* under the terms of the GNU General Public License version 2.
|
|
*/
|
|
|
|
#ifndef _INCLUDE__FILE_SYSTEM_SESSION__FILE_SYSTEM_SESSION_H_
|
|
#define _INCLUDE__FILE_SYSTEM_SESSION__FILE_SYSTEM_SESSION_H_
|
|
|
|
#include <base/exception.h>
|
|
#include <os/packet_stream.h>
|
|
#include <packet_stream_tx/packet_stream_tx.h>
|
|
#include <session/session.h>
|
|
|
|
namespace File_system {
|
|
|
|
using namespace Genode;
|
|
|
|
struct Node_handle
|
|
{
|
|
int value;
|
|
|
|
Node_handle() : value(-1) { }
|
|
Node_handle(int v) : value(v) { }
|
|
|
|
bool valid() const { return value != -1; }
|
|
};
|
|
|
|
|
|
struct File_handle : Node_handle
|
|
{
|
|
File_handle() { }
|
|
File_handle(int v) : Node_handle(v) { }
|
|
};
|
|
|
|
|
|
struct Dir_handle : Node_handle
|
|
{
|
|
Dir_handle() { }
|
|
Dir_handle(int v) : Node_handle(v) { }
|
|
};
|
|
|
|
|
|
struct Symlink_handle : Node_handle
|
|
{
|
|
Symlink_handle() { }
|
|
Symlink_handle(int v) : Node_handle(v) { }
|
|
};
|
|
|
|
|
|
/**
|
|
* Type of client context embedded in each packet descriptor
|
|
*
|
|
* Using the opaque refererence, the client is able to attribute incoming
|
|
* packet acknowledgements to a context that is meaningful for the client.
|
|
* It has no meaning at the server side.
|
|
*/
|
|
struct Packet_ref;
|
|
|
|
|
|
typedef uint64_t seek_off_t;
|
|
typedef uint64_t file_size_t;
|
|
|
|
|
|
class Packet_descriptor : public ::Packet_descriptor
|
|
{
|
|
public:
|
|
|
|
enum Opcode { READ, WRITE };
|
|
|
|
private:
|
|
|
|
Node_handle _handle; /* node handle */
|
|
Opcode _op; /* requested operation */
|
|
seek_off_t _position; /* seek offset in bytes */
|
|
size_t _length; /* transaction length in bytes */
|
|
bool _success; /* indicates success of operation */
|
|
Packet_ref *_ref; /* opaque reference used at the client side
|
|
for recognizing acknowledgements */
|
|
|
|
public:
|
|
|
|
/**
|
|
* Constructor
|
|
*/
|
|
Packet_descriptor(off_t offset = 0, size_t size = 0)
|
|
:
|
|
::Packet_descriptor(offset, size), _handle(-1),
|
|
_op(READ), _position(0), _length(0), _success(false) { }
|
|
|
|
/**
|
|
* Constructor
|
|
*
|
|
* \param position seek offset in bytes (by default, append)
|
|
*/
|
|
Packet_descriptor(Packet_descriptor p, Packet_ref *ref,
|
|
Node_handle handle, Opcode op, size_t length,
|
|
seek_off_t position = ~0)
|
|
:
|
|
::Packet_descriptor(p.offset(), p.size()),
|
|
_handle(handle), _op(op),
|
|
_position(position), _length(length), _success(false),
|
|
_ref(ref)
|
|
{ }
|
|
|
|
Node_handle handle() const { return _handle; }
|
|
Opcode operation() const { return _op; }
|
|
seek_off_t position() const { return _position; }
|
|
size_t length() const { return _length; }
|
|
bool succeeded() const { return _success; }
|
|
Packet_ref *ref() const { return _ref; }
|
|
|
|
/*
|
|
* Accessors called at the server side
|
|
*/
|
|
void succeeded(bool b) { _success = b ? 1 : 0; }
|
|
void length(size_t length) { _length = length; }
|
|
};
|
|
|
|
|
|
/**
|
|
* Flags as supplied to 'file', 'dir', and 'symlink' calls
|
|
*/
|
|
enum Mode { STAT_ONLY = 0, READ_ONLY = 1, WRITE_ONLY = 2, READ_WRITE = 3 };
|
|
|
|
enum { MAX_NAME_LEN = 256, MAX_PATH_LEN = 1024 };
|
|
|
|
typedef Rpc_in_buffer<MAX_NAME_LEN> Name;
|
|
typedef Rpc_in_buffer<MAX_PATH_LEN> Path;
|
|
|
|
|
|
struct Status
|
|
{
|
|
enum {
|
|
MODE_SYMLINK = 0020000,
|
|
MODE_FILE = 0100000,
|
|
MODE_DIRECTORY = 0040000,
|
|
};
|
|
|
|
/*
|
|
* XXX add access time
|
|
* XXX add executable bit
|
|
*/
|
|
|
|
file_size_t size;
|
|
unsigned mode;
|
|
unsigned long inode;
|
|
|
|
bool is_directory() const { return mode & MODE_DIRECTORY; }
|
|
bool is_symlink() const { return mode & MODE_SYMLINK; }
|
|
};
|
|
|
|
|
|
struct Control { /* to manipulate the executable bit */ };
|
|
|
|
|
|
/**
|
|
* Data structure returned when reading from a directory node
|
|
*/
|
|
struct Directory_entry
|
|
{
|
|
enum Type { TYPE_FILE, TYPE_DIRECTORY, TYPE_SYMLINK };
|
|
Type type;
|
|
char name[MAX_NAME_LEN];
|
|
};
|
|
|
|
|
|
/*
|
|
* Exception types
|
|
*/
|
|
class Exception : public Genode::Exception { };
|
|
class Permission_denied : Exception { };
|
|
class Node_already_exists : Exception { };
|
|
class Lookup_failed : Exception { };
|
|
class Name_too_long : Exception { };
|
|
class No_space : Exception { };
|
|
class Out_of_node_handles : Exception { };
|
|
class Invalid_handle : Exception { };
|
|
class Invalid_name : Exception { };
|
|
class Size_limit_reached : Exception { };
|
|
|
|
|
|
struct Session : public Genode::Session
|
|
{
|
|
enum { TX_QUEUE_SIZE = 16 };
|
|
|
|
typedef Packet_stream_policy<File_system::Packet_descriptor,
|
|
TX_QUEUE_SIZE, TX_QUEUE_SIZE,
|
|
char> Tx_policy;
|
|
|
|
typedef Packet_stream_tx::Channel<Tx_policy> Tx;
|
|
|
|
static const char *service_name() { return "File_system"; }
|
|
|
|
virtual ~Session() { }
|
|
|
|
/**
|
|
* Request client-side packet-stream interface of tx channel
|
|
*/
|
|
virtual Tx::Source *tx() { return 0; }
|
|
|
|
/**
|
|
* Open or create file
|
|
*
|
|
* \throw Invalid_handle directory handle is invalid
|
|
* \throw Node_already_exists file cannot be created because a
|
|
* node with the same name already exists
|
|
* \throw Invalid_name file name contains invalid characters
|
|
* \throw Lookup_failed the name refers to a node other than a
|
|
* file
|
|
*/
|
|
virtual File_handle file(Dir_handle, Name const &name, Mode, bool create) = 0;
|
|
|
|
/**
|
|
* Open or create symlink
|
|
*/
|
|
virtual Symlink_handle symlink(Dir_handle, Name const &name, bool create) = 0;
|
|
|
|
/**
|
|
* Open or create directory
|
|
*
|
|
* \throw Permission_denied
|
|
* \throw Node_already_exists directory cannot be created because a
|
|
* node with the same name already exists
|
|
* \throw Lookup_failed path lookup failed because one element
|
|
* of 'path' does not exist
|
|
* \throw Name_too_long
|
|
* \throw No_space
|
|
*/
|
|
virtual Dir_handle dir(Path const &path, bool create) = 0;
|
|
|
|
/**
|
|
* Open existing node
|
|
*
|
|
* The returned node handle can be used merely as argument for
|
|
* 'status'.
|
|
*/
|
|
virtual Node_handle node(Path const &path) = 0;
|
|
|
|
/**
|
|
* Close file
|
|
*/
|
|
virtual void close(Node_handle) = 0;
|
|
|
|
/**
|
|
* Request information about an open file or directory
|
|
*/
|
|
virtual Status status(Node_handle) = 0;
|
|
|
|
/**
|
|
* Set information about an open file or directory
|
|
*/
|
|
virtual void control(Node_handle, Control) = 0;
|
|
|
|
/**
|
|
* Delete file or directory
|
|
*/
|
|
virtual void unlink(Dir_handle, Name const &) = 0;
|
|
|
|
/**
|
|
* Truncate or grow file to specified size
|
|
*/
|
|
virtual void truncate(File_handle, file_size_t size) = 0;
|
|
|
|
/**
|
|
* Move and rename directory entry
|
|
*/
|
|
virtual void move(Dir_handle, Name const &from,
|
|
Dir_handle, Name const &to) = 0;
|
|
|
|
/**
|
|
* Register handler that should be notified on node changes
|
|
*/
|
|
virtual void sigh(Node_handle, Signal_context_capability sigh) = 0;
|
|
|
|
|
|
/*******************
|
|
** RPC interface **
|
|
*******************/
|
|
|
|
GENODE_RPC(Rpc_tx_cap, Capability<Tx>, _tx_cap);
|
|
GENODE_RPC_THROW(Rpc_file, File_handle, file,
|
|
GENODE_TYPE_LIST(Invalid_handle, Node_already_exists,
|
|
Invalid_name, Lookup_failed,
|
|
Permission_denied),
|
|
Dir_handle, Name const &, Mode, bool);
|
|
GENODE_RPC_THROW(Rpc_symlink, Symlink_handle, symlink,
|
|
GENODE_TYPE_LIST(Invalid_handle, Node_already_exists,
|
|
Invalid_name, Lookup_failed),
|
|
Dir_handle, Name const &, bool);
|
|
GENODE_RPC_THROW(Rpc_dir, Dir_handle, dir,
|
|
GENODE_TYPE_LIST(Permission_denied, Node_already_exists,
|
|
Lookup_failed, Name_too_long, No_space),
|
|
Path const &, bool);
|
|
GENODE_RPC_THROW(Rpc_node, Node_handle, node,
|
|
GENODE_TYPE_LIST(Lookup_failed),
|
|
Path const &);
|
|
GENODE_RPC(Rpc_close, void, close, Node_handle);
|
|
GENODE_RPC(Rpc_status, Status, status, Node_handle);
|
|
GENODE_RPC(Rpc_control, void, control, Node_handle, Control);
|
|
GENODE_RPC_THROW(Rpc_unlink, void, unlink,
|
|
GENODE_TYPE_LIST(Permission_denied, Invalid_name, Lookup_failed),
|
|
Dir_handle, Name const &);
|
|
GENODE_RPC_THROW(Rpc_truncate, void, truncate,
|
|
GENODE_TYPE_LIST(Permission_denied, Invalid_handle),
|
|
File_handle, file_size_t);
|
|
GENODE_RPC_THROW(Rpc_move, void, move,
|
|
GENODE_TYPE_LIST(Permission_denied, Invalid_name, Lookup_failed),
|
|
Dir_handle, Name const &, Dir_handle, Name const &);
|
|
GENODE_RPC_THROW(Rpc_sigh, void, sigh,
|
|
GENODE_TYPE_LIST(Invalid_handle),
|
|
Node_handle, Signal_context_capability);
|
|
|
|
/*
|
|
* Manual type-list definition, needed because the RPC interface
|
|
* exceeds the maximum number of type-list elements supported by
|
|
* 'Genode::Meta::Type_list<>'.
|
|
*/
|
|
typedef Meta::Type_tuple<Rpc_tx_cap,
|
|
Meta::Type_tuple<Rpc_file,
|
|
Meta::Type_tuple<Rpc_symlink,
|
|
Meta::Type_tuple<Rpc_dir,
|
|
Meta::Type_tuple<Rpc_node,
|
|
Meta::Type_tuple<Rpc_close,
|
|
Meta::Type_tuple<Rpc_status,
|
|
Meta::Type_tuple<Rpc_control,
|
|
Meta::Type_tuple<Rpc_unlink,
|
|
Meta::Type_tuple<Rpc_truncate,
|
|
Meta::Type_tuple<Rpc_move,
|
|
Meta::Type_tuple<Rpc_sigh,
|
|
Meta::Empty>
|
|
> > > > > > > > > > > Rpc_functions;
|
|
};
|
|
}
|
|
|
|
#endif /* _INCLUDE__FILE_SYSTEM_SESSION__FILE_SYSTEM_SESSION_H_ */
|