ladybird/Kernel/Syscalls/watch_file.cpp
2020-08-01 11:37:40 +02:00

60 lines
2.3 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <Kernel/FileSystem/Custody.h>
#include <Kernel/FileSystem/FileDescription.h>
#include <Kernel/FileSystem/InodeWatcher.h>
#include <Kernel/Process.h>
namespace Kernel {
int Process::sys$watch_file(Userspace<const char*> user_path, size_t path_length)
{
REQUIRE_PROMISE(rpath);
auto path = get_syscall_path_argument(user_path, path_length);
if (path.is_error())
return path.error();
auto custody_or_error = VFS::the().resolve_path(path.value(), current_directory());
if (custody_or_error.is_error())
return custody_or_error.error();
auto& custody = custody_or_error.value();
auto& inode = custody->inode();
if (!inode.fs().supports_watchers())
return -ENOTSUP;
int fd = alloc_fd();
if (fd < 0)
return fd;
m_fds[fd].set(FileDescription::create(*InodeWatcher::create(inode)));
m_fds[fd].description()->set_readable(true);
return fd;
}
}