656 lines
17 KiB
C++
656 lines
17 KiB
C++
/*
|
|
* \brief RAM file system
|
|
* \author Norman Feske
|
|
* \date 2012-04-11
|
|
*/
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
|
|
/* Genode includes */
|
|
#include <file_system/node_handle_registry.h>
|
|
#include <file_system_session/rpc_object.h>
|
|
#include <root/component.h>
|
|
#include <os/attached_rom_dataspace.h>
|
|
#include <os/config.h>
|
|
#include <os/server.h>
|
|
#include <os/session_policy.h>
|
|
#include <util/xml_node.h>
|
|
|
|
/* local includes */
|
|
#include <directory.h>
|
|
|
|
|
|
/*************************
|
|
** File-system service **
|
|
*************************/
|
|
|
|
namespace File_system {
|
|
|
|
class Session_component : public Session_rpc_object
|
|
{
|
|
private:
|
|
|
|
Server::Entrypoint &_ep;
|
|
Directory &_root;
|
|
Node_handle_registry _handle_registry;
|
|
bool _writable;
|
|
|
|
Signal_rpc_member<Session_component> _process_packet_dispatcher;
|
|
|
|
|
|
/******************************
|
|
** Packet-stream processing **
|
|
******************************/
|
|
|
|
/**
|
|
* Perform packet operation
|
|
*
|
|
* \return true on success, false on failure
|
|
*/
|
|
void _process_packet_op(Packet_descriptor &packet, Node &node)
|
|
{
|
|
void * const content = tx_sink()->packet_content(packet);
|
|
size_t const length = packet.length();
|
|
seek_off_t const offset = packet.position();
|
|
|
|
if (!content || (packet.length() > packet.size())) {
|
|
packet.succeeded(false);
|
|
return;
|
|
}
|
|
|
|
/* resulting length */
|
|
size_t res_length = 0;
|
|
|
|
switch (packet.operation()) {
|
|
|
|
case Packet_descriptor::READ:
|
|
res_length = node.read((char *)content, length, offset);
|
|
break;
|
|
|
|
case Packet_descriptor::WRITE:
|
|
res_length = node.write((char const *)content, length, offset);
|
|
break;
|
|
}
|
|
|
|
packet.length(res_length);
|
|
packet.succeeded(res_length > 0);
|
|
}
|
|
|
|
void _process_packet()
|
|
{
|
|
Packet_descriptor packet = tx_sink()->get_packet();
|
|
|
|
/* assume failure by default */
|
|
packet.succeeded(false);
|
|
|
|
try {
|
|
Node *node = _handle_registry.lookup_and_lock(packet.handle());
|
|
Node_lock_guard guard(node);
|
|
|
|
_process_packet_op(packet, *node);
|
|
}
|
|
catch (Invalid_handle) { PERR("Invalid_handle"); }
|
|
catch (Size_limit_reached) { PERR("Size_limit_reached"); }
|
|
|
|
/*
|
|
* The 'acknowledge_packet' function cannot block because we
|
|
* checked for 'ready_to_ack' in '_process_packets'.
|
|
*/
|
|
tx_sink()->acknowledge_packet(packet);
|
|
}
|
|
|
|
/**
|
|
* Called by signal dispatcher, executed in the context of the main
|
|
* thread (not serialized with the RPC functions)
|
|
*/
|
|
void _process_packets(unsigned)
|
|
{
|
|
while (tx_sink()->packet_avail()) {
|
|
|
|
/*
|
|
* Make sure that the '_process_packet' function does not
|
|
* block.
|
|
*
|
|
* If the acknowledgement queue is full, we defer packet
|
|
* processing until the client processed pending
|
|
* acknowledgements and thereby emitted a ready-to-ack
|
|
* signal. Otherwise, the call of 'acknowledge_packet()'
|
|
* in '_process_packet' would infinitely block the context
|
|
* of the main thread. The main thread is however needed
|
|
* for receiving any subsequent 'ready-to-ack' signals.
|
|
*/
|
|
if (!tx_sink()->ready_to_ack())
|
|
return;
|
|
|
|
_process_packet();
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Check if string represents a valid path (most start with '/')
|
|
*/
|
|
static void _assert_valid_path(char const *path)
|
|
{
|
|
if (!path || path[0] != '/') {
|
|
PWRN("malformed path '%s'", path);
|
|
throw Lookup_failed();
|
|
}
|
|
}
|
|
|
|
public:
|
|
|
|
/**
|
|
* Constructor
|
|
*/
|
|
Session_component(size_t tx_buf_size, Server::Entrypoint &ep,
|
|
Directory &root, bool writable)
|
|
:
|
|
Session_rpc_object(env()->ram_session()->alloc(tx_buf_size), ep.rpc_ep()),
|
|
_ep(ep),
|
|
_root(root),
|
|
_writable(writable),
|
|
_process_packet_dispatcher(ep, *this, &Session_component::_process_packets)
|
|
{
|
|
/*
|
|
* Register '_process_packets' dispatch function as signal
|
|
* handler for packet-avail and ready-to-ack signals.
|
|
*/
|
|
_tx.sigh_packet_avail(_process_packet_dispatcher);
|
|
_tx.sigh_ready_to_ack(_process_packet_dispatcher);
|
|
}
|
|
|
|
/**
|
|
* Destructor
|
|
*/
|
|
~Session_component()
|
|
{
|
|
Dataspace_capability ds = tx_sink()->dataspace();
|
|
env()->ram_session()->free(static_cap_cast<Ram_dataspace>(ds));
|
|
}
|
|
|
|
|
|
/***************************
|
|
** File_system interface **
|
|
***************************/
|
|
|
|
File_handle file(Dir_handle dir_handle, Name const &name,
|
|
Mode mode, bool create)
|
|
{
|
|
if (!valid_name(name.string()))
|
|
throw Invalid_name();
|
|
|
|
Directory *dir = _handle_registry.lookup_and_lock(dir_handle);
|
|
Node_lock_guard dir_guard(dir);
|
|
|
|
if (!_writable)
|
|
if (mode != STAT_ONLY && mode != READ_ONLY)
|
|
throw Permission_denied();
|
|
|
|
if (create) {
|
|
|
|
if (!_writable)
|
|
throw Permission_denied();
|
|
|
|
if (dir->has_sub_node_unsynchronized(name.string()))
|
|
throw Node_already_exists();
|
|
|
|
try {
|
|
File * const file = new (env()->heap())
|
|
File(*env()->heap(), name.string());
|
|
|
|
dir->adopt_unsynchronized(file);
|
|
}
|
|
catch (Allocator::Out_of_memory) { throw No_space(); }
|
|
}
|
|
|
|
File *file = dir->lookup_and_lock_file(name.string());
|
|
Node_lock_guard file_guard(file);
|
|
return _handle_registry.alloc(file);
|
|
}
|
|
|
|
Symlink_handle symlink(Dir_handle dir_handle, Name const &name, bool create)
|
|
{
|
|
if (!valid_name(name.string()))
|
|
throw Invalid_name();
|
|
|
|
Directory *dir = _handle_registry.lookup_and_lock(dir_handle);
|
|
Node_lock_guard dir_guard(dir);
|
|
|
|
if (create) {
|
|
|
|
if (!_writable)
|
|
throw Permission_denied();
|
|
|
|
if (dir->has_sub_node_unsynchronized(name.string()))
|
|
throw Node_already_exists();
|
|
|
|
try {
|
|
Symlink * const symlink = new (env()->heap())
|
|
Symlink(name.string());
|
|
|
|
dir->adopt_unsynchronized(symlink);
|
|
}
|
|
catch (Allocator::Out_of_memory) { throw No_space(); }
|
|
}
|
|
|
|
Symlink *symlink = dir->lookup_and_lock_symlink(name.string());
|
|
Node_lock_guard file_guard(symlink);
|
|
return _handle_registry.alloc(symlink);
|
|
}
|
|
|
|
Dir_handle dir(Path const &path, bool create)
|
|
{
|
|
char const *path_str = path.string();
|
|
|
|
_assert_valid_path(path_str);
|
|
|
|
/* skip leading '/' */
|
|
path_str++;
|
|
|
|
if (create) {
|
|
|
|
if (!_writable)
|
|
throw Permission_denied();
|
|
|
|
if (!path.is_valid_string())
|
|
throw Name_too_long();
|
|
|
|
Directory *parent = _root.lookup_and_lock_parent(path_str);
|
|
|
|
Node_lock_guard guard(parent);
|
|
|
|
char const *name = basename(path_str);
|
|
|
|
if (parent->has_sub_node_unsynchronized(name))
|
|
throw Node_already_exists();
|
|
|
|
try {
|
|
parent->adopt_unsynchronized(new (env()->heap()) Directory(name));
|
|
} catch (Allocator::Out_of_memory) {
|
|
throw No_space();
|
|
}
|
|
}
|
|
|
|
Directory *dir = _root.lookup_and_lock_dir(path_str);
|
|
Node_lock_guard guard(dir);
|
|
return _handle_registry.alloc(dir);
|
|
}
|
|
|
|
Node_handle node(Path const &path)
|
|
{
|
|
_assert_valid_path(path.string());
|
|
|
|
Node *node = _root.lookup_and_lock(path.string() + 1);
|
|
|
|
Node_lock_guard guard(node);
|
|
return _handle_registry.alloc(node);
|
|
}
|
|
|
|
void close(Node_handle handle)
|
|
{
|
|
_handle_registry.free(handle);
|
|
}
|
|
|
|
Status status(Node_handle node_handle)
|
|
{
|
|
Node *node = _handle_registry.lookup_and_lock(node_handle);
|
|
Node_lock_guard guard(node);
|
|
|
|
Status s;
|
|
s.inode = node->inode();
|
|
s.size = 0;
|
|
s.mode = 0;
|
|
|
|
File *file = dynamic_cast<File *>(node);
|
|
if (file) {
|
|
s.size = file->length();
|
|
s.mode = File_system::Status::MODE_FILE;
|
|
return s;
|
|
}
|
|
Directory *dir = dynamic_cast<Directory *>(node);
|
|
if (dir) {
|
|
s.size = dir->num_entries()*sizeof(Directory_entry);
|
|
s.mode = File_system::Status::MODE_DIRECTORY;
|
|
return s;
|
|
}
|
|
Symlink *symlink = dynamic_cast<Symlink *>(node);
|
|
if (symlink) {
|
|
s.size = symlink->length();
|
|
s.mode = File_system::Status::MODE_SYMLINK;
|
|
return s;
|
|
}
|
|
return Status();
|
|
}
|
|
|
|
void control(Node_handle, Control) { }
|
|
|
|
void unlink(Dir_handle dir_handle, Name const &name)
|
|
{
|
|
if (!valid_name(name.string()))
|
|
throw Invalid_name();
|
|
|
|
if (!_writable)
|
|
throw Permission_denied();
|
|
|
|
Directory *dir = _handle_registry.lookup_and_lock(dir_handle);
|
|
Node_lock_guard dir_guard(dir);
|
|
|
|
Node *node = dir->lookup_and_lock(name.string());
|
|
|
|
dir->discard_unsynchronized(node);
|
|
|
|
// XXX implement ref counting, do not destroy node that is
|
|
// is still referenced by a node handle
|
|
|
|
node->unlock();
|
|
destroy(env()->heap(), node);
|
|
}
|
|
|
|
void truncate(File_handle file_handle, file_size_t size)
|
|
{
|
|
if (!_writable)
|
|
throw Permission_denied();
|
|
|
|
File *file = _handle_registry.lookup_and_lock(file_handle);
|
|
Node_lock_guard file_guard(file);
|
|
file->truncate(size);
|
|
}
|
|
|
|
void move(Dir_handle from_dir_handle, Name const &from_name,
|
|
Dir_handle to_dir_handle, Name const &to_name)
|
|
{
|
|
if (!_writable)
|
|
throw Permission_denied();
|
|
|
|
if (!valid_name(from_name.string()))
|
|
throw Lookup_failed();
|
|
|
|
if (!valid_name(to_name.string()))
|
|
throw Invalid_name();
|
|
|
|
Directory *from_dir = _handle_registry.lookup_and_lock(from_dir_handle);
|
|
Node_lock_guard from_dir_guard(from_dir);
|
|
|
|
Node *node = from_dir->lookup_and_lock(from_name.string());
|
|
Node_lock_guard node_guard(node);
|
|
node->name(to_name.string());
|
|
|
|
if (!_handle_registry.refer_to_same_node(from_dir_handle, to_dir_handle)) {
|
|
Directory *to_dir = _handle_registry.lookup_and_lock(to_dir_handle);
|
|
Node_lock_guard to_dir_guard(to_dir);
|
|
|
|
from_dir->discard_unsynchronized(node);
|
|
to_dir->adopt_unsynchronized(node);
|
|
|
|
/*
|
|
* If the file was moved from one directory to another we
|
|
* need to inform the new directory 'to_dir'. The original
|
|
* directory 'from_dir' will always get notified (i.e.,
|
|
* when just the file name was changed) below.
|
|
*/
|
|
to_dir->mark_as_updated();
|
|
to_dir->notify_listeners();
|
|
}
|
|
|
|
from_dir->mark_as_updated();
|
|
from_dir->notify_listeners();
|
|
|
|
node->mark_as_updated();
|
|
node->notify_listeners();
|
|
}
|
|
|
|
void sigh(Node_handle node_handle, Signal_context_capability sigh)
|
|
{
|
|
_handle_registry.sigh(node_handle, sigh);
|
|
}
|
|
|
|
void sync() { }
|
|
};
|
|
|
|
|
|
class Root : public Root_component<Session_component>
|
|
{
|
|
private:
|
|
|
|
Server::Entrypoint &_ep;
|
|
Directory &_root_dir;
|
|
|
|
protected:
|
|
|
|
Session_component *_create_session(const char *args)
|
|
{
|
|
/*
|
|
* Determine client-specific policy defined implicitly by
|
|
* the client's label.
|
|
*/
|
|
|
|
Directory *session_root_dir = 0;
|
|
bool writeable = false;
|
|
|
|
enum { ROOT_MAX_LEN = 256 };
|
|
char root[ROOT_MAX_LEN];
|
|
root[0] = 0;
|
|
|
|
try {
|
|
Session_label label(args);
|
|
Session_policy policy(label);
|
|
|
|
/*
|
|
* Determine directory that is used as root directory of
|
|
* the session.
|
|
*/
|
|
try {
|
|
policy.attribute("root").value(root, sizeof(root));
|
|
if (strcmp("/", root) == 0) {
|
|
session_root_dir = &_root_dir;
|
|
} else {
|
|
|
|
/*
|
|
* Make sure the root path is specified with a
|
|
* leading path delimiter. For performing the
|
|
* lookup, we skip the first character.
|
|
*/
|
|
if (root[0] != '/')
|
|
throw Lookup_failed();
|
|
|
|
session_root_dir = _root_dir.lookup_and_lock_dir(root + 1);
|
|
session_root_dir->unlock();
|
|
}
|
|
} catch (Xml_node::Nonexistent_attribute) {
|
|
PERR("Missing \"root\" attribute in policy definition");
|
|
throw Root::Unavailable();
|
|
} catch (Lookup_failed) {
|
|
PERR("Session root directory \"%s\" does not exist", root);
|
|
throw Root::Unavailable();
|
|
}
|
|
|
|
/*
|
|
* Determine if write access is permitted for the session.
|
|
*/
|
|
try {
|
|
writeable = policy.attribute("writeable").has_value("yes");
|
|
} catch (Xml_node::Nonexistent_attribute) { }
|
|
|
|
} catch (Session_policy::No_policy_defined) {
|
|
PERR("Invalid session request, no matching policy");
|
|
throw Root::Unavailable();
|
|
}
|
|
|
|
size_t ram_quota =
|
|
Arg_string::find_arg(args, "ram_quota" ).ulong_value(0);
|
|
size_t tx_buf_size =
|
|
Arg_string::find_arg(args, "tx_buf_size").ulong_value(0);
|
|
|
|
/*
|
|
* Check if donated ram quota suffices for session data,
|
|
* and communication buffer.
|
|
*/
|
|
size_t session_size = sizeof(Session_component) + tx_buf_size;
|
|
if (max((size_t)4096, session_size) > ram_quota) {
|
|
PERR("insufficient 'ram_quota', got %zd, need %zd",
|
|
ram_quota, session_size);
|
|
throw Root::Quota_exceeded();
|
|
}
|
|
return new (md_alloc())
|
|
Session_component(tx_buf_size, _ep, *session_root_dir, writeable);
|
|
}
|
|
|
|
public:
|
|
|
|
/**
|
|
* Constructor
|
|
*
|
|
* \param ep entrypoint
|
|
* \param md_alloc meta-data allocator
|
|
* \param root_dir root-directory handle (anchor for fs)
|
|
*/
|
|
Root(Server::Entrypoint &ep, Allocator &md_alloc, Directory &root_dir)
|
|
:
|
|
Root_component<Session_component>(&ep.rpc_ep(), &md_alloc),
|
|
_ep(ep),
|
|
_root_dir(root_dir)
|
|
{ }
|
|
};
|
|
|
|
struct Main;
|
|
}
|
|
|
|
|
|
/**
|
|
* Helper for conveniently accessing 'Xml_node' attribute strings
|
|
*/
|
|
struct Attribute_string
|
|
{
|
|
char buf[File_system::MAX_NAME_LEN];
|
|
|
|
/**
|
|
* Constructor
|
|
*
|
|
* \param attr attribute name
|
|
* \param fallback if non-null, this is the string used if the attribute
|
|
* is not defined. If null, the constructor throws
|
|
* an 'Nonexistent_attribute' exception'
|
|
* \throw Xml_node::Nonexistent_attribute
|
|
*/
|
|
Attribute_string(Genode::Xml_node node, char const *attr, char *fallback = 0)
|
|
{
|
|
try {
|
|
node.attribute(attr).value(buf, sizeof(buf));
|
|
} catch (Genode::Xml_node::Nonexistent_attribute) {
|
|
|
|
if (fallback) {
|
|
Genode::strncpy(buf, fallback, sizeof(buf));
|
|
} else {
|
|
char type_name[16];
|
|
node.type_name(type_name, sizeof(type_name));
|
|
PWRN("missing \"%s\" attribute in <%s> node", attr, type_name);
|
|
throw Genode::Xml_node::Nonexistent_attribute();
|
|
}
|
|
}
|
|
}
|
|
|
|
operator char * () { return buf; }
|
|
};
|
|
|
|
|
|
static void preload_content(Genode::Allocator &alloc,
|
|
Genode::Xml_node node,
|
|
File_system::Directory &dir)
|
|
{
|
|
using namespace File_system;
|
|
|
|
for (unsigned i = 0; i < node.num_sub_nodes(); i++) {
|
|
Xml_node sub_node = node.sub_node(i);
|
|
|
|
/*
|
|
* Lookup name attribtue, let 'Nonexistent_attribute' exception fall
|
|
* through because this configuration error is considered fatal.
|
|
*/
|
|
Attribute_string name(sub_node, "name");
|
|
|
|
/*
|
|
* Create directory
|
|
*/
|
|
if (sub_node.has_type("dir")) {
|
|
|
|
Directory *sub_dir = new (&alloc) Directory(name);
|
|
|
|
/* traverse into the new directory */
|
|
preload_content(alloc, sub_node, *sub_dir);
|
|
|
|
dir.adopt_unsynchronized(sub_dir);
|
|
}
|
|
|
|
/*
|
|
* Create file from ROM module
|
|
*/
|
|
if (sub_node.has_type("rom")) {
|
|
|
|
/* read "as" attribute, use "name" as default */
|
|
Attribute_string as(sub_node, "as", name);
|
|
|
|
/* read file content from ROM module */
|
|
try {
|
|
Attached_rom_dataspace rom(name);
|
|
File *file = new (&alloc) File(alloc, as);
|
|
file->write(rom.local_addr<char>(), rom.size(), 0);
|
|
dir.adopt_unsynchronized(file);
|
|
}
|
|
catch (Rom_connection::Rom_connection_failed) {
|
|
PWRN("failed to open ROM file \"%s\"", (char *)name); }
|
|
catch (Rm_session::Attach_failed) {
|
|
PWRN("Could not locally attach ROM file \"%s\"", (char *)name); }
|
|
}
|
|
|
|
/*
|
|
* Create file from inline data provided as content of the XML node
|
|
*/
|
|
if (sub_node.has_type("inline")) {
|
|
|
|
File *file = new (&alloc) File(alloc, name);
|
|
file->write(sub_node.content_addr(), sub_node.content_size(), 0);
|
|
dir.adopt_unsynchronized(file);
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
struct File_system::Main
|
|
{
|
|
Server::Entrypoint &ep;
|
|
|
|
Directory root_dir = { "" };
|
|
|
|
/*
|
|
* Initialize root interface
|
|
*/
|
|
Sliced_heap sliced_heap = { env()->ram_session(), env()->rm_session() };
|
|
|
|
Root fs_root = { ep, sliced_heap, root_dir };
|
|
|
|
Main(Server::Entrypoint &ep) : ep(ep)
|
|
{
|
|
/* preload RAM file system with content as declared in the config */
|
|
try {
|
|
Xml_node content = config()->xml_node().sub_node("content");
|
|
preload_content(*env()->heap(), content, root_dir); }
|
|
catch (Xml_node::Nonexistent_sub_node) { }
|
|
|
|
env()->parent()->announce(ep.manage(fs_root));
|
|
}
|
|
};
|
|
|
|
|
|
/**********************
|
|
** Server framework **
|
|
**********************/
|
|
|
|
char const * Server::name() { return "ram_fs_ep"; }
|
|
Genode::size_t Server::stack_size() { return 2048 * sizeof(long); }
|
|
void Server::construct(Server::Entrypoint &ep) { static File_system::Main inst(ep); }
|