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7de2f57ef2
This patch removes the two 'Xml_node::attribute' accessors along with the 'Nonexistent_attribute' exception. Issue #5245 Fixes #5246
1035 lines
26 KiB
C++
1035 lines
26 KiB
C++
/*
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* \brief Directory file system
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* \author Norman Feske
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* \author Emery Hemingway
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* \author Christian Helmuth
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* \date 2012-04-23
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*/
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/*
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* Copyright (C) 2011-2019 Genode Labs GmbH
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*
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* This file is part of the Genode OS framework, which is distributed
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* under the terms of the GNU Affero General Public License version 3.
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*/
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#ifndef _INCLUDE__VFS__DIR_FILE_SYSTEM_H_
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#define _INCLUDE__VFS__DIR_FILE_SYSTEM_H_
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#include <base/registry.h>
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#include <vfs/file_system_factory.h>
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#include <vfs/vfs_handle.h>
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namespace Vfs { class Dir_file_system; }
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class Vfs::Dir_file_system : public File_system
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{
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public:
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enum { MAX_NAME_LEN = 128 };
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private:
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/*
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* Noncopyable
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*/
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Dir_file_system(Dir_file_system const &);
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Dir_file_system &operator = (Dir_file_system const &);
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Vfs::Env &_env;
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/**
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* This instance is the root of VFS
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*
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* Additionally, the root has an empty _name.
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*/
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bool const _vfs_root;
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struct Dir_vfs_handle : Vfs_handle
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{
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struct Subdir_handle_element;
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typedef Genode::Registry<Subdir_handle_element> Subdir_handle_registry;
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struct Subdir_handle_element : Subdir_handle_registry::Element
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{
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bool synced { false };
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Vfs_handle &vfs_handle;
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Subdir_handle_element(Subdir_handle_registry ®istry,
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Vfs_handle &vfs_handle)
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: Subdir_handle_registry::Element(registry, *this),
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vfs_handle(vfs_handle) { }
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};
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Absolute_path path;
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Vfs_handle *queued_read_handle { nullptr };
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Subdir_handle_registry subdir_handle_registry { };
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Dir_vfs_handle(Directory_service &ds,
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File_io_service &fs,
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Genode::Allocator &alloc,
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char const *path)
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: Vfs_handle(ds, fs, alloc, 0),
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path(path) { }
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~Dir_vfs_handle()
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{
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/* close all sub-handles */
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auto f = [&] (Subdir_handle_element &e) {
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e.vfs_handle.close();
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destroy(alloc(), &e);
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};
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subdir_handle_registry.for_each(f);
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}
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private:
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/*
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* Noncopyable
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*/
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Dir_vfs_handle(Dir_vfs_handle const &);
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Dir_vfs_handle &operator = (Dir_vfs_handle const &);
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};
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struct Dir_watch_handle : Vfs_watch_handle
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{
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struct Watch_handle_element;
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typedef Genode::Registry<Watch_handle_element> Watch_handle_registry;
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struct Watch_handle_element : Watch_handle_registry::Element
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{
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Vfs_watch_handle &watch_handle;
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Watch_handle_element(Watch_handle_registry ®istry,
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Vfs_watch_handle &handle)
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: Watch_handle_registry::Element(registry, *this),
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watch_handle(handle) { }
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};
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Watch_handle_registry handle_registry { };
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Dir_watch_handle(File_system &fs, Genode::Allocator &alloc)
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: Vfs_watch_handle(fs, alloc) { }
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~Dir_watch_handle()
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{
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/* close all sub-handles */
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auto f = [&] (Watch_handle_element &e) {
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e.watch_handle.close();
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destroy(alloc(), &e);
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};
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handle_registry.for_each(f);
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}
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/**
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* Propagate the response handler to each sub-handle
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*/
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void handler(Watch_response_handler *h) override
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{
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handle_registry.for_each( [&] (Watch_handle_element &elem) {
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elem.watch_handle.handler(h); } );
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}
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};
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/* pointer to first child file system */
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File_system *_first_file_system = nullptr;
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/* add new file system to the list of children */
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void _append_file_system(File_system *fs)
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{
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if (!_first_file_system) {
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_first_file_system = fs;
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return;
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}
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File_system *curr = _first_file_system;
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while (curr->next)
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curr = curr->next;
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curr->next = fs;
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}
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/**
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* Directory name
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*/
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typedef String<MAX_NAME_LEN> Name;
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Name const _name;
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/**
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* Returns if path corresponds to top directory of file system
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*/
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bool _top_dir(char const *path) const { return strcmp(path, "/") == 0; }
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/**
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* Perform operation on a file system
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*
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* \param fn functor that takes a file-system reference and
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* the path as arguments
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*/
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template <typename RES>
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RES _dir_op(RES const no_entry, RES const no_perm, RES const ok,
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char const *path, auto const &fn)
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{
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path = _sub_path(path);
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/* path does not match directory name */
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if (!path)
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return no_entry;
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/*
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* Prevent operation if path equals directory name defined
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* via the static VFS configuration.
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*/
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if (strlen(path) == 0)
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return no_perm;
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/*
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* If any of the sub file systems returns a permission error and
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* there exists no sub file system that takes the request, we
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* return the permission error.
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*/
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bool permission_denied = false;
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/*
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* Keep the most meaningful error code. When using stacked file
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* systems, most child file systems will eventually return no
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* entry (or leave the error code unchanged). If any of those
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* file systems has anything more interesting to tell, return
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* this information after all file systems have been tried and
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* none could handle the request.
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*/
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RES error = ok;
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/*
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* The given path refers to at least one of our sub directories.
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* Propagate the request into all of our file systems. If at least
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* one operation succeeds, we return success.
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*/
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for (File_system *fs = _first_file_system; fs; fs = fs->next) {
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RES const err = fn(*fs, path);
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if (err == ok)
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return err;
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if (err != no_entry && err != no_perm) {
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error = err;
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}
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if (err == no_perm)
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permission_denied = true;
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}
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/* none of our file systems could successfully operate on the path */
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return error != ok ? error : permission_denied ? no_perm : no_entry;
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}
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/**
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* Return portion of the path after the element corresponding to
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* the current directory.
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*/
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char const *_sub_path(char const *path) const
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{
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/* do not strip anything from the path when we are root */
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if (_vfs_root)
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return path;
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if (_top_dir(path))
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return path;
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/* skip heading slash in path if present */
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if (path[0] == '/')
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path++;
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Genode::size_t const name_len = strlen(_name.string());
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if (strcmp(path, _name.string(), name_len) != 0)
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return 0;
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path += name_len;
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/*
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* The first characters of the first path element are equal to
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* the current directory name. Let's check if the length of the
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* first path element matches the name length.
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*/
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if (*path != 0 && *path != '/')
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return 0;
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return path;
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}
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/*
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* Accumulate number of directory entries that match in any of
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* our sub file systems.
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*/
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file_size _sum_dirents_of_file_systems(char const *path)
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{
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file_size cnt = 0;
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for (File_system *fs = _first_file_system; fs; fs = fs->next) {
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cnt += fs->num_dirent(path);
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}
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return cnt;
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}
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bool _queue_read_of_file_systems(Dir_vfs_handle *dir_vfs_handle)
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{
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bool result = true;
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dir_vfs_handle->queued_read_handle = nullptr;
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file_offset index = dir_vfs_handle->seek() / sizeof(Dirent);
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char const *sub_path = _sub_path(dir_vfs_handle->path.base());
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if (strlen(sub_path) == 0)
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sub_path = "/";
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/* base of composite directory index */
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int base = 0;
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auto f = [&] (Dir_vfs_handle::Subdir_handle_element &handle_element) {
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if (dir_vfs_handle->queued_read_handle) return; /* skip through */
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Vfs_handle &vfs_handle = handle_element.vfs_handle;
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/*
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* Determine number of matching directory entries within
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* the current file system.
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*/
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int const fs_num_dirent = (int)vfs_handle.ds().num_dirent(sub_path);
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/*
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* Query directory entry if index lies with the file
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* system.
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*/
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if (index - base < fs_num_dirent) {
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/* set this handle to be used for read completion */
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dir_vfs_handle->queued_read_handle = &vfs_handle;
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/* seek to file-system local index */
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index = index - base;
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vfs_handle.seek(index * sizeof(Dirent));
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/* forward the response handler */
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dir_vfs_handle->apply_handler([&] (Vfs::Read_ready_response_handler &h) {
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vfs_handle.handler(&h); });
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result = vfs_handle.fs().queue_read(&vfs_handle, sizeof(Dirent));
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}
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/* adjust base index for next file system */
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base += fs_num_dirent;
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};
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dir_vfs_handle->subdir_handle_registry.for_each(f);
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return result;
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}
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Read_result _complete_read_of_file_systems(Dir_vfs_handle *dir_vfs_handle,
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Byte_range_ptr const &dst,
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size_t &out_count)
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{
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if (!dir_vfs_handle->queued_read_handle) {
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/*
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* no fs was found for the given index or
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* fs->opendir() failed
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*/
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if (dst.num_bytes < sizeof(Dirent))
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return READ_ERR_INVALID;
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Dirent &dirent = *(Dirent*)dst.start;
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dirent = Dirent { };
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out_count = sizeof(Dirent);
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return READ_OK;
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}
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Read_result result = dir_vfs_handle->queued_read_handle->fs().
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complete_read(dir_vfs_handle->queued_read_handle,
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dst, out_count);
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if (result == READ_QUEUED)
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return result;
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dir_vfs_handle->queued_read_handle = nullptr;
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return result;
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}
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public:
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Dir_file_system(Vfs::Env &env,
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Genode::Xml_node node,
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File_system_factory &fs_factory)
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:
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_env(env),
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_vfs_root(!node.has_type("dir")),
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_name(_vfs_root ? Name() : node.attribute_value("name", Name()))
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{
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using namespace Genode;
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for (unsigned i = 0; i < node.num_sub_nodes(); i++) {
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Xml_node sub_node = node.sub_node(i);
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/* traverse into <dir> nodes */
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if (sub_node.has_type("dir")) {
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_append_file_system(new (_env.alloc())
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Dir_file_system(_env, sub_node, fs_factory));
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continue;
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}
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File_system * const fs =
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fs_factory.create(_env, sub_node);
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if (fs) {
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_append_file_system(fs);
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continue;
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}
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Genode::error("failed to create VFS node: ", sub_node);
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}
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}
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/*********************************
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** Directory-service interface **
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*********************************/
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Dataspace_capability dataspace(char const *path) override
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{
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path = _sub_path(path);
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if (!path)
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return Dataspace_capability();
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/*
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* Query sub file systems for dataspace using the path local to
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* the respective file system
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*/
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File_system *fs = _first_file_system;
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for (; fs; fs = fs->next) {
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Dataspace_capability ds = fs->dataspace(path);
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if (ds.valid())
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return ds;
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}
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return Dataspace_capability();
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}
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void release(char const *path, Dataspace_capability ds_cap) override
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{
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path = _sub_path(path);
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if (!path)
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return;
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for (File_system *fs = _first_file_system; fs; fs = fs->next)
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fs->release(path, ds_cap);
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}
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Stat_result stat(char const *path, Stat &out) override
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{
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path = _sub_path(path);
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/* path does not match directory name */
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if (!path)
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return STAT_ERR_NO_ENTRY;
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/*
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* If path equals directory name, return information about the
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* current directory.
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*/
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if (strlen(path) == 0 || _top_dir(path)) {
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out = {
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.size = 0,
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.type = Node_type::DIRECTORY,
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.rwx = Node_rwx::rwx(),
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.inode = 1,
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.device = (Genode::addr_t)this,
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.modification_time = { Vfs::Timestamp::INVALID },
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};
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return STAT_OK;
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}
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/*
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* The given path refers to one of our sub directories.
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* Propagate the request into our file systems.
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*/
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for (File_system *fs = _first_file_system; fs; fs = fs->next) {
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Stat_result const err = fs->stat(path, out);
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if (err == STAT_OK)
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return err;
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if (err != STAT_ERR_NO_ENTRY)
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return err;
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}
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/* none of our file systems felt responsible for the path */
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return STAT_ERR_NO_ENTRY;
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}
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file_size num_dirent(char const *path) override
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{
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if (_vfs_root) {
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return _sum_dirents_of_file_systems(path);
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} else {
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if (_top_dir(path))
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return 1;
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/*
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* The path contains at least one element. Remove current
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* element from path.
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*/
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path = _sub_path(path);
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/*
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* If the resulting 'path' is non-null, the path lies
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* within our tree. In this case, determine the sum of
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* matching dirents of all our file systems. Otherwise,
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* the specified path lies outside our directory node.
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*/
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return path ? _sum_dirents_of_file_systems(*path ? path : "/") : 0;
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}
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}
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/**
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* Return true if specified path is a directory
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*/
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bool directory(char const *path) override
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{
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if (_top_dir(path))
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return true;
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path = _sub_path(path);
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if (!path)
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return false;
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if (strlen(path) == 0)
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return true;
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for (File_system *fs = _first_file_system; fs; fs = fs->next)
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if (fs->directory(path))
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return true;
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return false;
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}
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char const *leaf_path(char const *path) override
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{
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path = _sub_path(path);
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if (!path)
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return nullptr;
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if (strlen(path) == 0)
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return path;
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for (File_system *fs = _first_file_system; fs; fs = fs->next) {
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char const *leaf_path = fs->leaf_path(path);
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if (leaf_path)
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return leaf_path;
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}
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return nullptr;
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}
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Open_result open(char const *path,
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unsigned mode,
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Vfs_handle **out_handle,
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Allocator &alloc) override
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{
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/*
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* If 'path' is a directory, we create a 'Vfs_handle'
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* for the root directory so that subsequent 'dirent' calls
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* are subjected to the stacked file-system layout.
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*/
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if (directory(path)) {
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try {
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*out_handle = new (alloc) Dir_vfs_handle(*this, *this, alloc, path);
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return OPEN_OK;
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}
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catch (Genode::Out_of_ram) { return OPEN_ERR_OUT_OF_RAM; }
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catch (Genode::Out_of_caps) { return OPEN_ERR_OUT_OF_CAPS; }
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}
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/*
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* If 'path' refers to a non-directory node, create a
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* 'Vfs_handle' local to the file system that provides the
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* file.
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*/
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path = _sub_path(path);
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/* check if path does not match directory name */
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if (!path)
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return OPEN_ERR_UNACCESSIBLE;
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/* path equals directory name */
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if (strlen(path) == 0) {
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try {
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*out_handle = new (alloc) Vfs_handle(*this, *this, alloc, 0);
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return OPEN_OK;
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}
|
|
catch (Genode::Out_of_ram) { return OPEN_ERR_OUT_OF_RAM; }
|
|
catch (Genode::Out_of_caps) { return OPEN_ERR_OUT_OF_CAPS; }
|
|
}
|
|
|
|
/* path refers to any of our sub file systems */
|
|
for (File_system *fs = _first_file_system; fs; fs = fs->next) {
|
|
|
|
Open_result const err = fs->open(path, mode, out_handle, alloc);
|
|
switch (err) {
|
|
case OPEN_ERR_UNACCESSIBLE:
|
|
continue;
|
|
default:
|
|
return err;
|
|
}
|
|
}
|
|
|
|
/* path does not match any existing file or directory */
|
|
return OPEN_ERR_UNACCESSIBLE;
|
|
}
|
|
|
|
/**
|
|
* Call 'opendir()' on each file system and store handles in
|
|
* a registry.
|
|
*/
|
|
Opendir_result open_composite_dirs(char const *sub_path,
|
|
Dir_vfs_handle &dir_vfs_handle)
|
|
{
|
|
Opendir_result res;
|
|
if (strcmp(sub_path, "/")) {
|
|
|
|
/*
|
|
* If there are still directory names in the sub-path, we have
|
|
* not reached the leaf node of the original path so far.
|
|
* Therefore, if the current directory is empty, this means
|
|
* that the original path refers to a directory that doesn't
|
|
* exist. Consequently, the result defaults to a
|
|
* "lookup failed" error.
|
|
*/
|
|
res = OPENDIR_ERR_LOOKUP_FAILED;
|
|
|
|
} else {
|
|
|
|
/*
|
|
* We have reached the leaf node of the original path.
|
|
* Therefore the directory referenced by the original path is
|
|
* the one that we are at. Consequently, we can let the result
|
|
* default to "success" regardless of whether the directory is
|
|
* empty. However, if there are any sub-file-systems, we will
|
|
* go on and store handles for them in the registry.
|
|
*/
|
|
res = OPENDIR_OK;
|
|
}
|
|
try {
|
|
for (File_system *fs = _first_file_system; fs; fs = fs->next) {
|
|
Vfs_handle *sub_dir_handle = nullptr;
|
|
|
|
Opendir_result r = fs->opendir(
|
|
sub_path, false, &sub_dir_handle, dir_vfs_handle.alloc());
|
|
|
|
switch (r) {
|
|
case OPENDIR_OK:
|
|
break;
|
|
case OPENDIR_ERR_OUT_OF_RAM:
|
|
case OPENDIR_ERR_OUT_OF_CAPS:
|
|
return r;
|
|
default:
|
|
continue;
|
|
}
|
|
|
|
try {
|
|
new (dir_vfs_handle.alloc())
|
|
Dir_vfs_handle::Subdir_handle_element(
|
|
dir_vfs_handle.subdir_handle_registry, *sub_dir_handle);
|
|
}
|
|
catch (...) {
|
|
sub_dir_handle->close();
|
|
throw;
|
|
}
|
|
/* return OK because at least one directory has been opened */
|
|
res = OPENDIR_OK;
|
|
}
|
|
}
|
|
catch (Genode::Out_of_ram) { res = OPENDIR_ERR_OUT_OF_RAM; }
|
|
catch (Genode::Out_of_caps) { res = OPENDIR_ERR_OUT_OF_CAPS; }
|
|
|
|
return res;
|
|
}
|
|
|
|
Opendir_result opendir(char const *path, bool create,
|
|
Vfs_handle **out_handle, Allocator &alloc) override
|
|
{
|
|
Opendir_result result = OPENDIR_OK;
|
|
|
|
if (_top_dir(path)) {
|
|
if (create)
|
|
return OPENDIR_ERR_PERMISSION_DENIED;
|
|
|
|
/*
|
|
* opendir with '/' (called from 'open_composite_dirs' returns handle
|
|
* only, VFS root additionally calls 'open_composite_dirs' in order to
|
|
* open its file systems
|
|
*/
|
|
Dir_vfs_handle *root_handle;
|
|
try {
|
|
root_handle = new (alloc)
|
|
Dir_vfs_handle(*this, *this, alloc, path);
|
|
}
|
|
catch (Genode::Out_of_ram) { return OPENDIR_ERR_OUT_OF_RAM; }
|
|
catch (Genode::Out_of_caps) { return OPENDIR_ERR_OUT_OF_CAPS; }
|
|
|
|
/* the VFS root may contain more file systems */
|
|
if (_vfs_root)
|
|
result = open_composite_dirs("/", *root_handle);
|
|
|
|
if (result == OPENDIR_OK) {
|
|
*out_handle = root_handle;
|
|
} else {
|
|
/* close the root handle and the rest will follow */
|
|
close(root_handle);
|
|
}
|
|
return result;
|
|
}
|
|
|
|
char const *sub_path = _sub_path(path);
|
|
|
|
if (!sub_path)
|
|
return OPENDIR_ERR_LOOKUP_FAILED;
|
|
|
|
if (create) {
|
|
if (leaf_path(path) != nullptr)
|
|
return OPENDIR_ERR_NODE_ALREADY_EXISTS;
|
|
|
|
auto opendir_fn = [&] (File_system &fs, char const *path)
|
|
{
|
|
Vfs_handle *tmp_handle;
|
|
Opendir_result opendir_result =
|
|
fs.opendir(path, true, &tmp_handle, alloc);
|
|
if (opendir_result == OPENDIR_OK) {
|
|
tmp_handle->close();
|
|
}
|
|
return opendir_result; /* return from lambda */
|
|
};
|
|
|
|
Opendir_result opendir_result =
|
|
_dir_op(OPENDIR_ERR_LOOKUP_FAILED,
|
|
OPENDIR_ERR_PERMISSION_DENIED,
|
|
OPENDIR_OK,
|
|
path, opendir_fn);
|
|
|
|
if (opendir_result != OPENDIR_OK)
|
|
return opendir_result;
|
|
}
|
|
|
|
Dir_vfs_handle *dir_vfs_handle;
|
|
try {
|
|
dir_vfs_handle = new (alloc)
|
|
Dir_vfs_handle(*this, *this, alloc, path);
|
|
}
|
|
catch (Genode::Out_of_ram) { return OPENDIR_ERR_OUT_OF_RAM; }
|
|
catch (Genode::Out_of_caps) { return OPENDIR_ERR_OUT_OF_CAPS; }
|
|
|
|
/* path equals "/" (for reading the name of this directory) */
|
|
if (strlen(sub_path) == 0)
|
|
sub_path = "/";
|
|
|
|
result = open_composite_dirs(sub_path, *dir_vfs_handle);
|
|
if (result == OPENDIR_OK) {
|
|
*out_handle = dir_vfs_handle;
|
|
} else {
|
|
/* close the master handle and the rest will follow */
|
|
close(dir_vfs_handle);
|
|
}
|
|
return result;
|
|
}
|
|
|
|
Openlink_result openlink(char const *path, bool create,
|
|
Vfs_handle **out_handle,
|
|
Allocator &alloc) override
|
|
{
|
|
auto openlink_fn = [&] (File_system &fs, char const *path)
|
|
{
|
|
return fs.openlink(path, create, out_handle, alloc);
|
|
};
|
|
|
|
return _dir_op(OPENLINK_ERR_LOOKUP_FAILED,
|
|
OPENLINK_ERR_PERMISSION_DENIED,
|
|
OPENLINK_OK,
|
|
path, openlink_fn);
|
|
}
|
|
|
|
void close(Vfs_handle *handle) override
|
|
{
|
|
if (handle && (&handle->ds() == this))
|
|
destroy(handle->alloc(), handle);
|
|
}
|
|
|
|
Watch_result watch(char const *path,
|
|
Vfs_watch_handle **handle,
|
|
Allocator &alloc) override
|
|
{
|
|
Watch_result res = WATCH_ERR_UNACCESSIBLE;
|
|
Dir_watch_handle *meta_handle = nullptr;
|
|
|
|
char const *sub_path = _sub_path(path);
|
|
if (!sub_path) return res;
|
|
|
|
for (File_system *fs = _first_file_system; fs; fs = fs->next) {
|
|
Vfs_watch_handle *sub_handle;
|
|
|
|
if (fs->watch(sub_path, &sub_handle, alloc) == WATCH_OK) {
|
|
if (meta_handle == nullptr) {
|
|
/* at least one non-static FS, allocate handle */
|
|
meta_handle = new (alloc) Dir_watch_handle(*this, alloc);
|
|
*handle = meta_handle;
|
|
res = WATCH_OK;
|
|
}
|
|
|
|
/* attach child FS handle to returned handle */
|
|
new (alloc)
|
|
Dir_watch_handle::Watch_handle_element(
|
|
meta_handle->handle_registry, *sub_handle);
|
|
}
|
|
}
|
|
|
|
return res;
|
|
}
|
|
|
|
void close(Vfs_watch_handle *handle) override
|
|
{
|
|
if (handle && (&handle->fs() == this))
|
|
destroy(handle->alloc(), handle);
|
|
}
|
|
|
|
Unlink_result unlink(char const *path) override
|
|
{
|
|
auto unlink_fn = [] (File_system &fs, char const *path)
|
|
{
|
|
return fs.unlink(path);
|
|
};
|
|
|
|
return _dir_op(UNLINK_ERR_NO_ENTRY, UNLINK_ERR_NO_PERM, UNLINK_OK,
|
|
path, unlink_fn);
|
|
}
|
|
|
|
Rename_result rename(char const *from_path, char const *to_path) override
|
|
{
|
|
from_path = _sub_path(from_path);
|
|
to_path = _sub_path(to_path);
|
|
|
|
/* path does not match directory name */
|
|
if (!from_path)
|
|
return RENAME_ERR_NO_ENTRY;
|
|
|
|
/*
|
|
* Cannot rename a path in the static VFS configuration.
|
|
*/
|
|
if (strlen(from_path) == 0)
|
|
return RENAME_ERR_NO_PERM;
|
|
|
|
/*
|
|
* Check if destination path resides within the same file
|
|
* system instance as the source path.
|
|
*/
|
|
if (!to_path)
|
|
return RENAME_ERR_CROSS_FS;
|
|
|
|
Rename_result final = RENAME_ERR_NO_ENTRY;
|
|
for (File_system *fs = _first_file_system; fs; fs = fs->next) {
|
|
switch (fs->rename(from_path, to_path)) {
|
|
case RENAME_OK: return RENAME_OK;
|
|
case RENAME_ERR_NO_ENTRY: continue;
|
|
case RENAME_ERR_NO_PERM: return RENAME_ERR_NO_PERM;
|
|
case RENAME_ERR_CROSS_FS: final = RENAME_ERR_CROSS_FS;
|
|
}
|
|
}
|
|
return final;
|
|
}
|
|
|
|
/***************************
|
|
** File_system interface **
|
|
***************************/
|
|
|
|
char const *name() const { return "dir"; }
|
|
char const *type() override { return "dir"; }
|
|
|
|
void apply_config(Genode::Xml_node const &node) override
|
|
{
|
|
using namespace Genode;
|
|
|
|
File_system *curr = _first_file_system;
|
|
for (unsigned i = 0; i < node.num_sub_nodes(); i++, curr = curr->next) {
|
|
Xml_node const &sub_node = node.sub_node(i);
|
|
|
|
/* check if type of XML node matches current file-system type */
|
|
if (sub_node.has_type(curr->type()) == false) {
|
|
Genode::error("VFS config update failed (node type '",
|
|
sub_node.type(), "' != fs type '", curr->type(),"')");
|
|
return;
|
|
}
|
|
|
|
curr->apply_config(node.sub_node(i));
|
|
}
|
|
}
|
|
|
|
|
|
/********************************
|
|
** File I/O service interface **
|
|
********************************/
|
|
|
|
Write_result write(Vfs_handle *, Const_byte_range_ptr const &, size_t &) override
|
|
{
|
|
return WRITE_ERR_INVALID;
|
|
}
|
|
|
|
bool queue_read(Vfs_handle *vfs_handle, size_t) override
|
|
{
|
|
Dir_vfs_handle *dir_vfs_handle =
|
|
static_cast<Dir_vfs_handle*>(vfs_handle);
|
|
|
|
if (_vfs_root)
|
|
return _queue_read_of_file_systems(dir_vfs_handle);
|
|
|
|
if (_top_dir(dir_vfs_handle->path.base()))
|
|
return true;
|
|
|
|
return _queue_read_of_file_systems(dir_vfs_handle);
|
|
}
|
|
|
|
Read_result complete_read(Vfs_handle *vfs_handle,
|
|
Byte_range_ptr const &dst,
|
|
size_t &out_count) override
|
|
{
|
|
out_count = 0;
|
|
|
|
if (dst.num_bytes < sizeof(Dirent))
|
|
return READ_ERR_INVALID;
|
|
|
|
Dir_vfs_handle *dir_vfs_handle =
|
|
static_cast<Dir_vfs_handle*>(vfs_handle);
|
|
|
|
if (_vfs_root)
|
|
return _complete_read_of_file_systems(dir_vfs_handle, dst, out_count);
|
|
|
|
if (_top_dir(dir_vfs_handle->path.base())) {
|
|
|
|
Dirent &dirent = *(Dirent*)dst.start;
|
|
|
|
file_offset const index = vfs_handle->seek() / sizeof(Dirent);
|
|
|
|
if (index == 0) {
|
|
|
|
dirent = {
|
|
.fileno = 1,
|
|
.type = Dirent_type::DIRECTORY,
|
|
.rwx = Node_rwx::rwx(),
|
|
.name = { _name.string() }
|
|
};
|
|
|
|
} else {
|
|
|
|
dirent = {
|
|
.fileno = 0,
|
|
.type = Dirent_type::END,
|
|
.rwx = { },
|
|
.name = { }
|
|
};
|
|
}
|
|
|
|
out_count = sizeof(Dirent);
|
|
|
|
return READ_OK;
|
|
}
|
|
|
|
return _complete_read_of_file_systems(dir_vfs_handle, dst, out_count);
|
|
}
|
|
|
|
Ftruncate_result ftruncate(Vfs_handle *, file_size) override
|
|
{
|
|
return FTRUNCATE_ERR_NO_PERM;
|
|
}
|
|
|
|
bool read_ready(Vfs_handle const &handle) const override
|
|
{
|
|
if (&handle.fs() == this)
|
|
return true;
|
|
|
|
return handle.fs().read_ready(handle);
|
|
}
|
|
|
|
bool write_ready(Vfs_handle const &handle) const override
|
|
{
|
|
if (&handle.fs() == this)
|
|
return false;
|
|
|
|
return handle.fs().write_ready(handle);
|
|
}
|
|
|
|
bool notify_read_ready(Vfs_handle *handle) override
|
|
{
|
|
if (&handle->fs() == this)
|
|
return true;
|
|
|
|
return handle->fs().notify_read_ready(handle);
|
|
}
|
|
|
|
bool queue_sync(Vfs_handle *vfs_handle) override
|
|
{
|
|
bool result = true;
|
|
|
|
Dir_vfs_handle *dir_vfs_handle =
|
|
static_cast<Dir_vfs_handle*>(vfs_handle);
|
|
|
|
auto f = [&result, dir_vfs_handle] (Dir_vfs_handle::Subdir_handle_element &e) {
|
|
/* forward the response handler */
|
|
dir_vfs_handle->apply_handler([&] (Read_ready_response_handler &h) {
|
|
e.vfs_handle.handler(&h); });
|
|
e.synced = false;
|
|
|
|
if (!e.vfs_handle.fs().queue_sync(&e.vfs_handle)) {
|
|
result = false;
|
|
}
|
|
};
|
|
|
|
dir_vfs_handle->subdir_handle_registry.for_each(f);
|
|
|
|
return result;
|
|
}
|
|
|
|
Sync_result complete_sync(Vfs_handle *vfs_handle) override
|
|
{
|
|
Sync_result result = SYNC_OK;
|
|
|
|
Dir_vfs_handle *dir_vfs_handle =
|
|
static_cast<Dir_vfs_handle*>(vfs_handle);
|
|
|
|
auto f = [&result] (Dir_vfs_handle::Subdir_handle_element &e) {
|
|
if (e.synced)
|
|
return;
|
|
|
|
Sync_result r = e.vfs_handle.fs().complete_sync(&e.vfs_handle);
|
|
if (r != SYNC_OK)
|
|
result = r;
|
|
else
|
|
e.synced = true;
|
|
};
|
|
|
|
dir_vfs_handle->subdir_handle_registry.for_each(f);
|
|
|
|
return result;
|
|
}
|
|
};
|
|
|
|
#endif /* _INCLUDE__VFS__DIR_FILE_SYSTEM_H_ */
|