1*2dbef785SGnoCiYeH use core::ffi::CStr; 2*2dbef785SGnoCiYeH 31496ba7bSLoGin use alloc::{ 41496ba7bSLoGin string::{String, ToString}, 51496ba7bSLoGin sync::Arc, 61496ba7bSLoGin vec::Vec, 71496ba7bSLoGin }; 8004e86ffSlogin 9004e86ffSlogin use crate::{ 10*2dbef785SGnoCiYeH driver::base::{block::SeekFrom, device::DeviceNumber}, 112b771e32SGou Ngai filesystem::vfs::file::FileDescriptorVec, 12*2dbef785SGnoCiYeH include::bindings::bindings::{verify_area, AT_REMOVEDIR, PROC_MAX_FD_NUM}, 132b771e32SGou Ngai kerror, 141496ba7bSLoGin libs::rwlock::RwLockWriteGuard, 151496ba7bSLoGin mm::VirtAddr, 161496ba7bSLoGin process::ProcessManager, 17*2dbef785SGnoCiYeH syscall::{user_access::UserBufferReader, Syscall, SystemError}, 1867b48188Shoumkh time::TimeSpec, 19004e86ffSlogin }; 20004e86ffSlogin 21004e86ffSlogin use super::{ 22ab5c8ca4Slogin core::{do_mkdir, do_remove_dir, do_unlink_at}, 236d81180bSLoGin fcntl::{FcntlCommand, FD_CLOEXEC}, 24004e86ffSlogin file::{File, FileMode}, 25ab5c8ca4Slogin utils::rsplit_path, 26*2dbef785SGnoCiYeH Dirent, FileType, IndexNode, MAX_PATHLEN, ROOT_INODE, 27004e86ffSlogin }; 28004e86ffSlogin 29ab5c8ca4Slogin pub const SEEK_SET: u32 = 0; 30ab5c8ca4Slogin pub const SEEK_CUR: u32 = 1; 31ab5c8ca4Slogin pub const SEEK_END: u32 = 2; 32ab5c8ca4Slogin pub const SEEK_MAX: u32 = 3; 33004e86ffSlogin 3467b48188Shoumkh bitflags! { 3567b48188Shoumkh /// 文件类型和权限 366b4e7a29SLoGin #[repr(C)] 3767b48188Shoumkh pub struct ModeType: u32 { 3867b48188Shoumkh /// 掩码 3967b48188Shoumkh const S_IFMT = 0o0_170_000; 4067b48188Shoumkh /// 文件类型 4167b48188Shoumkh const S_IFSOCK = 0o140000; 4267b48188Shoumkh const S_IFLNK = 0o120000; 4367b48188Shoumkh const S_IFREG = 0o100000; 4467b48188Shoumkh const S_IFBLK = 0o060000; 4567b48188Shoumkh const S_IFDIR = 0o040000; 4667b48188Shoumkh const S_IFCHR = 0o020000; 4767b48188Shoumkh const S_IFIFO = 0o010000; 4867b48188Shoumkh 4967b48188Shoumkh const S_ISUID = 0o004000; 5067b48188Shoumkh const S_ISGID = 0o002000; 5167b48188Shoumkh const S_ISVTX = 0o001000; 5267b48188Shoumkh /// 文件用户权限 5367b48188Shoumkh const S_IRWXU = 0o0700; 5467b48188Shoumkh const S_IRUSR = 0o0400; 5567b48188Shoumkh const S_IWUSR = 0o0200; 5667b48188Shoumkh const S_IXUSR = 0o0100; 5767b48188Shoumkh /// 文件组权限 5867b48188Shoumkh const S_IRWXG = 0o0070; 5967b48188Shoumkh const S_IRGRP = 0o0040; 6067b48188Shoumkh const S_IWGRP = 0o0020; 6167b48188Shoumkh const S_IXGRP = 0o0010; 6267b48188Shoumkh /// 文件其他用户权限 6367b48188Shoumkh const S_IRWXO = 0o0007; 6467b48188Shoumkh const S_IROTH = 0o0004; 6567b48188Shoumkh const S_IWOTH = 0o0002; 6667b48188Shoumkh const S_IXOTH = 0o0001; 6767b48188Shoumkh } 6867b48188Shoumkh } 6967b48188Shoumkh 7067b48188Shoumkh #[repr(C)] 7167b48188Shoumkh /// # 文件信息结构体 7267b48188Shoumkh pub struct PosixKstat { 7367b48188Shoumkh /// 硬件设备ID 7467b48188Shoumkh dev_id: u64, 7567b48188Shoumkh /// inode号 7667b48188Shoumkh inode: u64, 7767b48188Shoumkh /// 硬链接数 7867b48188Shoumkh nlink: u64, 7967b48188Shoumkh /// 文件权限 8067b48188Shoumkh mode: ModeType, 8167b48188Shoumkh /// 所有者用户ID 8267b48188Shoumkh uid: i32, 8367b48188Shoumkh /// 所有者组ID 8467b48188Shoumkh gid: i32, 8567b48188Shoumkh /// 设备ID 8667b48188Shoumkh rdev: i64, 8767b48188Shoumkh /// 文件大小 8867b48188Shoumkh size: i64, 8967b48188Shoumkh /// 文件系统块大小 9067b48188Shoumkh blcok_size: i64, 9167b48188Shoumkh /// 分配的512B块数 9267b48188Shoumkh blocks: u64, 9367b48188Shoumkh /// 最后访问时间 9467b48188Shoumkh atime: TimeSpec, 9567b48188Shoumkh /// 最后修改时间 9667b48188Shoumkh mtime: TimeSpec, 9767b48188Shoumkh /// 最后状态变化时间 9867b48188Shoumkh ctime: TimeSpec, 9967b48188Shoumkh /// 用于填充结构体大小的空白数据 10067b48188Shoumkh pub _pad: [i8; 24], 10167b48188Shoumkh } 10267b48188Shoumkh impl PosixKstat { 10367b48188Shoumkh fn new() -> Self { 10467b48188Shoumkh Self { 10567b48188Shoumkh inode: 0, 10667b48188Shoumkh dev_id: 0, 10767b48188Shoumkh mode: ModeType { bits: 0 }, 10867b48188Shoumkh nlink: 0, 10967b48188Shoumkh uid: 0, 11067b48188Shoumkh gid: 0, 11167b48188Shoumkh rdev: 0, 11267b48188Shoumkh size: 0, 11367b48188Shoumkh atime: TimeSpec { 11467b48188Shoumkh tv_sec: 0, 11567b48188Shoumkh tv_nsec: 0, 11667b48188Shoumkh }, 11767b48188Shoumkh mtime: TimeSpec { 11867b48188Shoumkh tv_sec: 0, 11967b48188Shoumkh tv_nsec: 0, 12067b48188Shoumkh }, 12167b48188Shoumkh ctime: TimeSpec { 12267b48188Shoumkh tv_sec: 0, 12367b48188Shoumkh tv_nsec: 0, 12467b48188Shoumkh }, 12567b48188Shoumkh blcok_size: 0, 12667b48188Shoumkh blocks: 0, 12767b48188Shoumkh _pad: Default::default(), 12867b48188Shoumkh } 12967b48188Shoumkh } 13067b48188Shoumkh } 131ab5c8ca4Slogin impl Syscall { 132ab5c8ca4Slogin /// @brief 为当前进程打开一个文件 133ab5c8ca4Slogin /// 134ab5c8ca4Slogin /// @param path 文件路径 135ab5c8ca4Slogin /// @param o_flags 打开文件的标志位 136ab5c8ca4Slogin /// 137ab5c8ca4Slogin /// @return 文件描述符编号,或者是错误码 138ab5c8ca4Slogin pub fn open(path: &str, mode: FileMode) -> Result<usize, SystemError> { 1396d81180bSLoGin // kdebug!("open: path: {}, mode: {:?}", path, mode); 1401496ba7bSLoGin 141ab5c8ca4Slogin // 文件名过长 142*2dbef785SGnoCiYeH if path.len() > MAX_PATHLEN as usize { 143ab5c8ca4Slogin return Err(SystemError::ENAMETOOLONG); 144ab5c8ca4Slogin } 145ab5c8ca4Slogin 146ab5c8ca4Slogin let inode: Result<Arc<dyn IndexNode>, SystemError> = ROOT_INODE().lookup(path); 147ab5c8ca4Slogin 148ab5c8ca4Slogin let inode: Arc<dyn IndexNode> = if inode.is_err() { 149ab5c8ca4Slogin let errno = inode.unwrap_err(); 150ab5c8ca4Slogin // 文件不存在,且需要创建 151ab5c8ca4Slogin if mode.contains(FileMode::O_CREAT) 152ab5c8ca4Slogin && !mode.contains(FileMode::O_DIRECTORY) 153ab5c8ca4Slogin && errno == SystemError::ENOENT 154ab5c8ca4Slogin { 155ab5c8ca4Slogin let (filename, parent_path) = rsplit_path(path); 156ab5c8ca4Slogin // 查找父目录 157ab5c8ca4Slogin let parent_inode: Arc<dyn IndexNode> = 158ab5c8ca4Slogin ROOT_INODE().lookup(parent_path.unwrap_or("/"))?; 159ab5c8ca4Slogin // 创建文件 1606b4e7a29SLoGin let inode: Arc<dyn IndexNode> = parent_inode.create( 1616b4e7a29SLoGin filename, 1626b4e7a29SLoGin FileType::File, 1636b4e7a29SLoGin ModeType::from_bits_truncate(0o755), 1646b4e7a29SLoGin )?; 165ab5c8ca4Slogin inode 166004e86ffSlogin } else { 167ab5c8ca4Slogin // 不需要创建文件,因此返回错误码 168ab5c8ca4Slogin return Err(errno); 169004e86ffSlogin } 170004e86ffSlogin } else { 171ab5c8ca4Slogin inode.unwrap() 172004e86ffSlogin }; 173004e86ffSlogin 174ab5c8ca4Slogin let file_type: FileType = inode.metadata()?.file_type; 175ab5c8ca4Slogin // 如果要打开的是文件夹,而目标不是文件夹 176ab5c8ca4Slogin if mode.contains(FileMode::O_DIRECTORY) && file_type != FileType::Dir { 177ab5c8ca4Slogin return Err(SystemError::ENOTDIR); 178004e86ffSlogin } 179ab5c8ca4Slogin 180ab5c8ca4Slogin // 如果O_TRUNC,并且,打开模式包含O_RDWR或O_WRONLY,清空文件 181ab5c8ca4Slogin if mode.contains(FileMode::O_TRUNC) 182ab5c8ca4Slogin && (mode.contains(FileMode::O_RDWR) || mode.contains(FileMode::O_WRONLY)) 183ab5c8ca4Slogin && file_type == FileType::File 184ab5c8ca4Slogin { 185ab5c8ca4Slogin inode.truncate(0)?; 186ab5c8ca4Slogin } 187ab5c8ca4Slogin 188ab5c8ca4Slogin // 创建文件对象 18934e6d6c8Syuyi2439 190ab5c8ca4Slogin let mut file: File = File::new(inode, mode)?; 191ab5c8ca4Slogin 192ab5c8ca4Slogin // 打开模式为“追加” 193ab5c8ca4Slogin if mode.contains(FileMode::O_APPEND) { 194ab5c8ca4Slogin file.lseek(SeekFrom::SeekEnd(0))?; 195ab5c8ca4Slogin } 196ab5c8ca4Slogin 197ab5c8ca4Slogin // 把文件对象存入pcb 1981496ba7bSLoGin let r = ProcessManager::current_pcb() 1991496ba7bSLoGin .fd_table() 2001496ba7bSLoGin .write() 2011496ba7bSLoGin .alloc_fd(file, None) 2021496ba7bSLoGin .map(|fd| fd as usize); 2031496ba7bSLoGin 2046d81180bSLoGin return r; 205ab5c8ca4Slogin } 206ab5c8ca4Slogin 207ab5c8ca4Slogin /// @brief 关闭文件 208ab5c8ca4Slogin /// 209ab5c8ca4Slogin /// @param fd 文件描述符编号 210ab5c8ca4Slogin /// 211ab5c8ca4Slogin /// @return 成功返回0,失败返回错误码 212ab5c8ca4Slogin pub fn close(fd: usize) -> Result<usize, SystemError> { 2131496ba7bSLoGin let binding = ProcessManager::current_pcb().fd_table(); 2141496ba7bSLoGin let mut fd_table_guard = binding.write(); 2151496ba7bSLoGin 21634e6d6c8Syuyi2439 let res = fd_table_guard.drop_fd(fd as i32).map(|_| 0); 21734e6d6c8Syuyi2439 21834e6d6c8Syuyi2439 return res; 219ab5c8ca4Slogin } 220ab5c8ca4Slogin 221ab5c8ca4Slogin /// @brief 根据文件描述符,读取文件数据。尝试读取的数据长度与buf的长度相同。 222ab5c8ca4Slogin /// 223ab5c8ca4Slogin /// @param fd 文件描述符编号 224ab5c8ca4Slogin /// @param buf 输出缓冲区。 225ab5c8ca4Slogin /// 226ab5c8ca4Slogin /// @return Ok(usize) 成功读取的数据的字节数 227ab5c8ca4Slogin /// @return Err(SystemError) 读取失败,返回posix错误码 228ab5c8ca4Slogin pub fn read(fd: i32, buf: &mut [u8]) -> Result<usize, SystemError> { 2291496ba7bSLoGin let binding = ProcessManager::current_pcb().fd_table(); 2301496ba7bSLoGin let fd_table_guard = binding.read(); 2311496ba7bSLoGin 2321496ba7bSLoGin let file = fd_table_guard.get_file_by_fd(fd); 233ab5c8ca4Slogin if file.is_none() { 234ab5c8ca4Slogin return Err(SystemError::EBADF); 235ab5c8ca4Slogin } 2361496ba7bSLoGin // drop guard 以避免无法调度的问题 2371496ba7bSLoGin drop(fd_table_guard); 2381496ba7bSLoGin let file = file.unwrap(); 239ab5c8ca4Slogin 2401496ba7bSLoGin return file.lock_no_preempt().read(buf.len(), buf); 241ab5c8ca4Slogin } 242ab5c8ca4Slogin 243ab5c8ca4Slogin /// @brief 根据文件描述符,向文件写入数据。尝试写入的数据长度与buf的长度相同。 244ab5c8ca4Slogin /// 245ab5c8ca4Slogin /// @param fd 文件描述符编号 246ab5c8ca4Slogin /// @param buf 输入缓冲区。 247ab5c8ca4Slogin /// 248ab5c8ca4Slogin /// @return Ok(usize) 成功写入的数据的字节数 249ab5c8ca4Slogin /// @return Err(SystemError) 写入失败,返回posix错误码 250ab5c8ca4Slogin pub fn write(fd: i32, buf: &[u8]) -> Result<usize, SystemError> { 2511496ba7bSLoGin let binding = ProcessManager::current_pcb().fd_table(); 2521496ba7bSLoGin let fd_table_guard = binding.read(); 253ab5c8ca4Slogin 2541496ba7bSLoGin let file = fd_table_guard 2551496ba7bSLoGin .get_file_by_fd(fd) 2561496ba7bSLoGin .ok_or(SystemError::EBADF)?; 2571496ba7bSLoGin 2581496ba7bSLoGin // drop guard 以避免无法调度的问题 2591496ba7bSLoGin drop(fd_table_guard); 2601496ba7bSLoGin return file.lock_no_preempt().write(buf.len(), buf); 261ab5c8ca4Slogin } 262ab5c8ca4Slogin 263ab5c8ca4Slogin /// @brief 调整文件操作指针的位置 264ab5c8ca4Slogin /// 265ab5c8ca4Slogin /// @param fd 文件描述符编号 266ab5c8ca4Slogin /// @param seek 调整的方式 267ab5c8ca4Slogin /// 268ab5c8ca4Slogin /// @return Ok(usize) 调整后,文件访问指针相对于文件头部的偏移量 269ab5c8ca4Slogin /// @return Err(SystemError) 调整失败,返回posix错误码 270ab5c8ca4Slogin pub fn lseek(fd: i32, seek: SeekFrom) -> Result<usize, SystemError> { 2711496ba7bSLoGin let binding = ProcessManager::current_pcb().fd_table(); 2721496ba7bSLoGin let fd_table_guard = binding.read(); 2731496ba7bSLoGin let file = fd_table_guard 2741496ba7bSLoGin .get_file_by_fd(fd) 2751496ba7bSLoGin .ok_or(SystemError::EBADF)?; 2761496ba7bSLoGin 2771496ba7bSLoGin // drop guard 以避免无法调度的问题 2781496ba7bSLoGin drop(fd_table_guard); 2791496ba7bSLoGin return file.lock_no_preempt().lseek(seek); 280004e86ffSlogin } 281004e86ffSlogin 282004e86ffSlogin /// @brief 切换工作目录 283004e86ffSlogin /// 284004e86ffSlogin /// @param dest_path 目标路径 285004e86ffSlogin /// 286004e86ffSlogin /// @return 返回码 描述 287004e86ffSlogin /// 0 | 成功 288004e86ffSlogin /// 289004e86ffSlogin /// EACCESS | 权限不足 290004e86ffSlogin /// 291004e86ffSlogin /// ELOOP | 解析path时遇到路径循环 292004e86ffSlogin /// 293004e86ffSlogin /// ENAMETOOLONG | 路径名过长 294004e86ffSlogin /// 295004e86ffSlogin /// ENOENT | 目标文件或目录不存在 296004e86ffSlogin /// 297004e86ffSlogin /// ENODIR | 检索期间发现非目录项 298004e86ffSlogin /// 299004e86ffSlogin /// ENOMEM | 系统内存不足 300004e86ffSlogin /// 301004e86ffSlogin /// EFAULT | 错误的地址 302004e86ffSlogin /// 303004e86ffSlogin /// ENAMETOOLONG | 路径过长 304ab5c8ca4Slogin pub fn chdir(dest_path: &str) -> Result<usize, SystemError> { 3051496ba7bSLoGin let proc = ProcessManager::current_pcb(); 306ab5c8ca4Slogin // Copy path to kernel space to avoid some security issues 3071496ba7bSLoGin let path = dest_path.to_string(); 3081496ba7bSLoGin let mut new_path = String::from(""); 3091496ba7bSLoGin if path.len() > 0 { 3101496ba7bSLoGin let cwd = match path.as_bytes()[0] { 3111496ba7bSLoGin b'/' => String::from("/"), 3121496ba7bSLoGin _ => proc.basic().cwd(), 3131496ba7bSLoGin }; 3141496ba7bSLoGin let mut cwd_vec: Vec<_> = cwd.split("/").filter(|&x| x != "").collect(); 3151496ba7bSLoGin let path_split = path.split("/").filter(|&x| x != ""); 3161496ba7bSLoGin for seg in path_split { 3171496ba7bSLoGin if seg == ".." { 3181496ba7bSLoGin cwd_vec.pop(); 3191496ba7bSLoGin } else if seg == "." { 3201496ba7bSLoGin // 当前目录 3211496ba7bSLoGin } else { 3221496ba7bSLoGin cwd_vec.push(seg); 3231496ba7bSLoGin } 3241496ba7bSLoGin } 3251496ba7bSLoGin //proc.basic().set_path(String::from("")); 3261496ba7bSLoGin for seg in cwd_vec { 3271496ba7bSLoGin new_path.push_str("/"); 3281496ba7bSLoGin new_path.push_str(seg); 3291496ba7bSLoGin } 3301496ba7bSLoGin if new_path == "" { 3311496ba7bSLoGin new_path = String::from("/"); 3321496ba7bSLoGin } 3331496ba7bSLoGin } 3341496ba7bSLoGin let inode = match ROOT_INODE().lookup(&new_path) { 335004e86ffSlogin Err(e) => { 336676b8ef6SMork kerror!("Change Directory Failed, Error = {:?}", e); 337ab5c8ca4Slogin return Err(SystemError::ENOENT); 338004e86ffSlogin } 339004e86ffSlogin Ok(i) => i, 340004e86ffSlogin }; 3411496ba7bSLoGin let metadata = inode.metadata()?; 3421496ba7bSLoGin if metadata.file_type == FileType::Dir { 3431496ba7bSLoGin proc.basic_mut().set_cwd(String::from(new_path)); 344ab5c8ca4Slogin return Ok(0); 345004e86ffSlogin } else { 346ab5c8ca4Slogin return Err(SystemError::ENOTDIR); 347004e86ffSlogin } 348004e86ffSlogin } 3491496ba7bSLoGin 3501496ba7bSLoGin /// @brief 获取当前进程的工作目录路径 3511496ba7bSLoGin /// 3521496ba7bSLoGin /// @param buf 指向缓冲区的指针 3531496ba7bSLoGin /// @param size 缓冲区的大小 3541496ba7bSLoGin /// 3551496ba7bSLoGin /// @return 成功,返回的指针指向包含工作目录路径的字符串 3561496ba7bSLoGin /// @return 错误,没有足够的空间 3571496ba7bSLoGin pub fn getcwd(buf: &mut [u8]) -> Result<VirtAddr, SystemError> { 3581496ba7bSLoGin let proc = ProcessManager::current_pcb(); 3591496ba7bSLoGin let cwd = proc.basic().cwd(); 3601496ba7bSLoGin 3611496ba7bSLoGin let cwd_bytes = cwd.as_bytes(); 3621496ba7bSLoGin let cwd_len = cwd_bytes.len(); 3631496ba7bSLoGin if cwd_len + 1 > buf.len() { 3641496ba7bSLoGin return Err(SystemError::ENOMEM); 365004e86ffSlogin } 3661496ba7bSLoGin buf[..cwd_len].copy_from_slice(cwd_bytes); 3671496ba7bSLoGin buf[cwd_len] = 0; 3681496ba7bSLoGin 3691496ba7bSLoGin return Ok(VirtAddr::new(buf.as_ptr() as usize)); 370004e86ffSlogin } 371004e86ffSlogin 372004e86ffSlogin /// @brief 获取目录中的数据 373004e86ffSlogin /// 374ab5c8ca4Slogin /// TODO: 这个函数的语义与Linux不一致,需要修改!!! 375ab5c8ca4Slogin /// 376004e86ffSlogin /// @param fd 文件描述符号 377ab5c8ca4Slogin /// @param buf 输出缓冲区 378ab5c8ca4Slogin /// 379ab5c8ca4Slogin /// @return 成功返回读取的字节数,失败返回错误码 380ab5c8ca4Slogin pub fn getdents(fd: i32, buf: &mut [u8]) -> Result<usize, SystemError> { 381ab5c8ca4Slogin let dirent = 382ab5c8ca4Slogin unsafe { (buf.as_mut_ptr() as *mut Dirent).as_mut() }.ok_or(SystemError::EFAULT)?; 383004e86ffSlogin 384004e86ffSlogin if fd < 0 || fd as u32 > PROC_MAX_FD_NUM { 385ab5c8ca4Slogin return Err(SystemError::EBADF); 386004e86ffSlogin } 387004e86ffSlogin 388004e86ffSlogin // 获取fd 3891496ba7bSLoGin let binding = ProcessManager::current_pcb().fd_table(); 3901496ba7bSLoGin let fd_table_guard = binding.read(); 3911496ba7bSLoGin let file = fd_table_guard 3921496ba7bSLoGin .get_file_by_fd(fd) 3931496ba7bSLoGin .ok_or(SystemError::EBADF)?; 394004e86ffSlogin 3951496ba7bSLoGin // drop guard 以避免无法调度的问题 3961496ba7bSLoGin drop(fd_table_guard); 39734e6d6c8Syuyi2439 39834e6d6c8Syuyi2439 let res = file.lock_no_preempt().readdir(dirent).map(|x| x as usize); 39934e6d6c8Syuyi2439 40034e6d6c8Syuyi2439 return res; 401004e86ffSlogin } 402004e86ffSlogin 403004e86ffSlogin /// @brief 创建文件夹 404004e86ffSlogin /// 405004e86ffSlogin /// @param path(r8) 路径 / mode(r9) 模式 406004e86ffSlogin /// 407004e86ffSlogin /// @return uint64_t 负数错误码 / 0表示成功 408ab5c8ca4Slogin pub fn mkdir(path: &str, mode: usize) -> Result<usize, SystemError> { 409ab5c8ca4Slogin return do_mkdir(path, FileMode::from_bits_truncate(mode as u32)).map(|x| x as usize); 410004e86ffSlogin } 411004e86ffSlogin 412ab5c8ca4Slogin /// **删除文件夹、取消文件的链接、删除文件的系统调用** 413004e86ffSlogin /// 414ab5c8ca4Slogin /// ## 参数 415004e86ffSlogin /// 416ab5c8ca4Slogin /// - `dirfd`:文件夹的文件描述符.目前暂未实现 417ab5c8ca4Slogin /// - `pathname`:文件夹的路径 418ab5c8ca4Slogin /// - `flags`:标志位 419004e86ffSlogin /// 420004e86ffSlogin /// 421ab5c8ca4Slogin pub fn unlinkat(_dirfd: i32, pathname: &str, flags: u32) -> Result<usize, SystemError> { 422004e86ffSlogin // kdebug!("sys_unlink_at={path:?}"); 423ab5c8ca4Slogin if (flags & (!AT_REMOVEDIR)) != 0 { 424ab5c8ca4Slogin return Err(SystemError::EINVAL); 425004e86ffSlogin } 426004e86ffSlogin 427ab5c8ca4Slogin if (flags & AT_REMOVEDIR) > 0 { 428004e86ffSlogin // kdebug!("rmdir"); 429ab5c8ca4Slogin match do_remove_dir(&pathname) { 430004e86ffSlogin Err(err) => { 431676b8ef6SMork kerror!("Failed to Remove Directory, Error Code = {:?}", err); 432ab5c8ca4Slogin return Err(err); 433004e86ffSlogin } 434004e86ffSlogin Ok(_) => { 435ab5c8ca4Slogin return Ok(0); 436004e86ffSlogin } 437004e86ffSlogin } 438004e86ffSlogin } 439004e86ffSlogin 440ab5c8ca4Slogin match do_unlink_at(&pathname, FileMode::from_bits_truncate(flags as u32)) { 441004e86ffSlogin Err(err) => { 442676b8ef6SMork kerror!("Failed to Remove Directory, Error Code = {:?}", err); 443ab5c8ca4Slogin return Err(err); 444004e86ffSlogin } 445004e86ffSlogin Ok(_) => { 446ab5c8ca4Slogin return Ok(0); 447004e86ffSlogin } 448004e86ffSlogin } 449004e86ffSlogin } 4502b771e32SGou Ngai 451ab5c8ca4Slogin /// @brief 根据提供的文件描述符的fd,复制对应的文件结构体,并返回新复制的文件结构体对应的fd 452ab5c8ca4Slogin pub fn dup(oldfd: i32) -> Result<usize, SystemError> { 4531496ba7bSLoGin let binding = ProcessManager::current_pcb().fd_table(); 4541496ba7bSLoGin let mut fd_table_guard = binding.write(); 455ab5c8ca4Slogin 4561496ba7bSLoGin let old_file = fd_table_guard 4571496ba7bSLoGin .get_file_by_fd(oldfd) 4581496ba7bSLoGin .ok_or(SystemError::EBADF)?; 4591496ba7bSLoGin 4601496ba7bSLoGin let new_file = old_file 4611496ba7bSLoGin .lock_no_preempt() 4621496ba7bSLoGin .try_clone() 4631496ba7bSLoGin .ok_or(SystemError::EBADF)?; 4642b771e32SGou Ngai // 申请文件描述符,并把文件对象存入其中 4651496ba7bSLoGin let res = fd_table_guard.alloc_fd(new_file, None).map(|x| x as usize); 4662b771e32SGou Ngai return res; 4672b771e32SGou Ngai } 4682b771e32SGou Ngai 469ab5c8ca4Slogin /// 根据提供的文件描述符的fd,和指定新fd,复制对应的文件结构体, 470ab5c8ca4Slogin /// 并返回新复制的文件结构体对应的fd. 471ab5c8ca4Slogin /// 如果新fd已经打开,则会先关闭新fd. 472ab5c8ca4Slogin /// 473ab5c8ca4Slogin /// ## 参数 474ab5c8ca4Slogin /// 475ab5c8ca4Slogin /// - `oldfd`:旧文件描述符 476ab5c8ca4Slogin /// - `newfd`:新文件描述符 477ab5c8ca4Slogin /// 478ab5c8ca4Slogin /// ## 返回值 479ab5c8ca4Slogin /// 480ab5c8ca4Slogin /// - 成功:新文件描述符 481ab5c8ca4Slogin /// - 失败:错误码 482ab5c8ca4Slogin pub fn dup2(oldfd: i32, newfd: i32) -> Result<usize, SystemError> { 4831496ba7bSLoGin let binding = ProcessManager::current_pcb().fd_table(); 4841496ba7bSLoGin let mut fd_table_guard = binding.write(); 4851496ba7bSLoGin return Self::do_dup2(oldfd, newfd, &mut fd_table_guard); 4861496ba7bSLoGin } 4871496ba7bSLoGin 4881496ba7bSLoGin fn do_dup2( 4891496ba7bSLoGin oldfd: i32, 4901496ba7bSLoGin newfd: i32, 4911496ba7bSLoGin fd_table_guard: &mut RwLockWriteGuard<'_, FileDescriptorVec>, 4921496ba7bSLoGin ) -> Result<usize, SystemError> { 4932b771e32SGou Ngai // 确认oldfd, newid是否有效 4941496ba7bSLoGin if !(FileDescriptorVec::validate_fd(oldfd) && FileDescriptorVec::validate_fd(newfd)) { 4951496ba7bSLoGin return Err(SystemError::EBADF); 4961496ba7bSLoGin } 4971496ba7bSLoGin 4982b771e32SGou Ngai if oldfd == newfd { 4992b771e32SGou Ngai // 若oldfd与newfd相等 500ab5c8ca4Slogin return Ok(newfd as usize); 5012b771e32SGou Ngai } 5021496ba7bSLoGin let new_exists = fd_table_guard.get_file_by_fd(newfd).is_some(); 5031496ba7bSLoGin if new_exists { 5042b771e32SGou Ngai // close newfd 5051496ba7bSLoGin if let Err(_) = fd_table_guard.drop_fd(newfd) { 5062b771e32SGou Ngai // An I/O error occurred while attempting to close fildes2. 5072b771e32SGou Ngai return Err(SystemError::EIO); 5082b771e32SGou Ngai } 5092b771e32SGou Ngai } 5102b771e32SGou Ngai 5111496ba7bSLoGin let old_file = fd_table_guard 5121496ba7bSLoGin .get_file_by_fd(oldfd) 5131496ba7bSLoGin .ok_or(SystemError::EBADF)?; 5141496ba7bSLoGin let new_file = old_file 5151496ba7bSLoGin .lock_no_preempt() 5161496ba7bSLoGin .try_clone() 5171496ba7bSLoGin .ok_or(SystemError::EBADF)?; 5182b771e32SGou Ngai // 申请文件描述符,并把文件对象存入其中 5191496ba7bSLoGin let res = fd_table_guard 5201496ba7bSLoGin .alloc_fd(new_file, Some(newfd)) 521ab5c8ca4Slogin .map(|x| x as usize); 5222b771e32SGou Ngai return res; 5232b771e32SGou Ngai } 5246d81180bSLoGin 5256d81180bSLoGin /// # fcntl 5266d81180bSLoGin /// 5276d81180bSLoGin /// ## 参数 5286d81180bSLoGin /// 5296d81180bSLoGin /// - `fd`:文件描述符 5306d81180bSLoGin /// - `cmd`:命令 5316d81180bSLoGin /// - `arg`:参数 5326d81180bSLoGin pub fn fcntl(fd: i32, cmd: FcntlCommand, arg: i32) -> Result<usize, SystemError> { 5336d81180bSLoGin match cmd { 5346d81180bSLoGin FcntlCommand::DupFd => { 5356d81180bSLoGin if arg < 0 || arg as usize >= FileDescriptorVec::PROCESS_MAX_FD { 5366d81180bSLoGin return Err(SystemError::EBADF); 5376d81180bSLoGin } 5386d81180bSLoGin let arg = arg as usize; 5396d81180bSLoGin for i in arg..FileDescriptorVec::PROCESS_MAX_FD { 5401496ba7bSLoGin let binding = ProcessManager::current_pcb().fd_table(); 5411496ba7bSLoGin let mut fd_table_guard = binding.write(); 5421496ba7bSLoGin if fd_table_guard.get_file_by_fd(fd).is_none() { 5431496ba7bSLoGin return Self::do_dup2(fd, i as i32, &mut fd_table_guard); 5446d81180bSLoGin } 5456d81180bSLoGin } 5466d81180bSLoGin return Err(SystemError::EMFILE); 5476d81180bSLoGin } 5486d81180bSLoGin FcntlCommand::GetFd => { 5496d81180bSLoGin // Get file descriptor flags. 5501496ba7bSLoGin let binding = ProcessManager::current_pcb().fd_table(); 5511496ba7bSLoGin let fd_table_guard = binding.read(); 5521496ba7bSLoGin if let Some(file) = fd_table_guard.get_file_by_fd(fd) { 5531496ba7bSLoGin // drop guard 以避免无法调度的问题 5541496ba7bSLoGin drop(fd_table_guard); 5556d81180bSLoGin 5561496ba7bSLoGin if file.lock().close_on_exec() { 5576d81180bSLoGin return Ok(FD_CLOEXEC as usize); 5586d81180bSLoGin } 5596d81180bSLoGin } 5606d81180bSLoGin return Err(SystemError::EBADF); 5616d81180bSLoGin } 5626d81180bSLoGin FcntlCommand::SetFd => { 5636d81180bSLoGin // Set file descriptor flags. 5641496ba7bSLoGin let binding = ProcessManager::current_pcb().fd_table(); 5651496ba7bSLoGin let fd_table_guard = binding.write(); 5661496ba7bSLoGin 5671496ba7bSLoGin if let Some(file) = fd_table_guard.get_file_by_fd(fd) { 5681496ba7bSLoGin // drop guard 以避免无法调度的问题 5691496ba7bSLoGin drop(fd_table_guard); 5706d81180bSLoGin let arg = arg as u32; 5716d81180bSLoGin if arg & FD_CLOEXEC != 0 { 5721496ba7bSLoGin file.lock().set_close_on_exec(true); 5736d81180bSLoGin } else { 5741496ba7bSLoGin file.lock().set_close_on_exec(false); 5756d81180bSLoGin } 5766d81180bSLoGin return Ok(0); 5776d81180bSLoGin } 5786d81180bSLoGin return Err(SystemError::EBADF); 5796d81180bSLoGin } 5806d81180bSLoGin 5816d81180bSLoGin FcntlCommand::GetFlags => { 5826d81180bSLoGin // Get file status flags. 5831496ba7bSLoGin let binding = ProcessManager::current_pcb().fd_table(); 5841496ba7bSLoGin let fd_table_guard = binding.read(); 5851496ba7bSLoGin 5861496ba7bSLoGin if let Some(file) = fd_table_guard.get_file_by_fd(fd) { 5871496ba7bSLoGin // drop guard 以避免无法调度的问题 5881496ba7bSLoGin drop(fd_table_guard); 5891496ba7bSLoGin return Ok(file.lock_no_preempt().mode().bits() as usize); 5906d81180bSLoGin } 5911496ba7bSLoGin 5926d81180bSLoGin return Err(SystemError::EBADF); 5936d81180bSLoGin } 5946d81180bSLoGin FcntlCommand::SetFlags => { 5956d81180bSLoGin // Set file status flags. 5961496ba7bSLoGin let binding = ProcessManager::current_pcb().fd_table(); 5971496ba7bSLoGin let fd_table_guard = binding.write(); 5981496ba7bSLoGin 5991496ba7bSLoGin if let Some(file) = fd_table_guard.get_file_by_fd(fd) { 6006d81180bSLoGin let arg = arg as u32; 6016d81180bSLoGin let mode = FileMode::from_bits(arg).ok_or(SystemError::EINVAL)?; 6021496ba7bSLoGin // drop guard 以避免无法调度的问题 6031496ba7bSLoGin drop(fd_table_guard); 6041496ba7bSLoGin file.lock_no_preempt().set_mode(mode)?; 6056d81180bSLoGin return Ok(0); 6066d81180bSLoGin } 6071496ba7bSLoGin 6086d81180bSLoGin return Err(SystemError::EBADF); 6096d81180bSLoGin } 6106d81180bSLoGin _ => { 6116d81180bSLoGin // TODO: unimplemented 6126d81180bSLoGin // 未实现的命令,返回0,不报错。 6136d81180bSLoGin 6146d81180bSLoGin // kwarn!("fcntl: unimplemented command: {:?}, defaults to 0.", cmd); 6156d81180bSLoGin return Ok(0); 6166d81180bSLoGin } 6176d81180bSLoGin } 6186d81180bSLoGin } 6196d81180bSLoGin 6206d81180bSLoGin /// # ftruncate 6216d81180bSLoGin /// 6226d81180bSLoGin /// ## 描述 6236d81180bSLoGin /// 6246d81180bSLoGin /// 改变文件大小. 6256d81180bSLoGin /// 如果文件大小大于原来的大小,那么文件的内容将会被扩展到指定的大小,新的空间将会用0填充. 6266d81180bSLoGin /// 如果文件大小小于原来的大小,那么文件的内容将会被截断到指定的大小. 6276d81180bSLoGin /// 6286d81180bSLoGin /// ## 参数 6296d81180bSLoGin /// 6306d81180bSLoGin /// - `fd`:文件描述符 6316d81180bSLoGin /// - `len`:文件大小 6326d81180bSLoGin /// 6336d81180bSLoGin /// ## 返回值 6346d81180bSLoGin /// 6356d81180bSLoGin /// 如果成功,返回0,否则返回错误码. 6366d81180bSLoGin pub fn ftruncate(fd: i32, len: usize) -> Result<usize, SystemError> { 6371496ba7bSLoGin let binding = ProcessManager::current_pcb().fd_table(); 6381496ba7bSLoGin let fd_table_guard = binding.read(); 6391496ba7bSLoGin 6401496ba7bSLoGin if let Some(file) = fd_table_guard.get_file_by_fd(fd) { 6411496ba7bSLoGin // drop guard 以避免无法调度的问题 6421496ba7bSLoGin drop(fd_table_guard); 6431496ba7bSLoGin let r = file.lock_no_preempt().ftruncate(len).map(|_| 0); 6446d81180bSLoGin return r; 6456d81180bSLoGin } 6461496ba7bSLoGin 6476d81180bSLoGin return Err(SystemError::EBADF); 6486d81180bSLoGin } 6491496ba7bSLoGin 65067b48188Shoumkh fn do_fstat(fd: i32) -> Result<PosixKstat, SystemError> { 6511496ba7bSLoGin let binding = ProcessManager::current_pcb().fd_table(); 6521496ba7bSLoGin let fd_table_guard = binding.read(); 6531496ba7bSLoGin let file = fd_table_guard 6541496ba7bSLoGin .get_file_by_fd(fd) 6551496ba7bSLoGin .ok_or(SystemError::EBADF)?; 6561496ba7bSLoGin // drop guard 以避免无法调度的问题 6571496ba7bSLoGin drop(fd_table_guard); 6581496ba7bSLoGin 65967b48188Shoumkh let mut kstat = PosixKstat::new(); 66067b48188Shoumkh // 获取文件信息 6611496ba7bSLoGin let metadata = file.lock().metadata()?; 66267b48188Shoumkh kstat.size = metadata.size as i64; 66367b48188Shoumkh kstat.dev_id = metadata.dev_id as u64; 6646b4e7a29SLoGin kstat.inode = metadata.inode_id.into() as u64; 66567b48188Shoumkh kstat.blcok_size = metadata.blk_size as i64; 66667b48188Shoumkh kstat.blocks = metadata.blocks as u64; 66767b48188Shoumkh 66867b48188Shoumkh kstat.atime.tv_sec = metadata.atime.tv_sec; 66967b48188Shoumkh kstat.atime.tv_nsec = metadata.atime.tv_nsec; 67067b48188Shoumkh kstat.mtime.tv_sec = metadata.mtime.tv_sec; 67167b48188Shoumkh kstat.mtime.tv_nsec = metadata.mtime.tv_nsec; 67267b48188Shoumkh kstat.ctime.tv_sec = metadata.ctime.tv_sec; 67367b48188Shoumkh kstat.ctime.tv_nsec = metadata.ctime.tv_nsec; 67467b48188Shoumkh 67567b48188Shoumkh kstat.nlink = metadata.nlinks as u64; 67667b48188Shoumkh kstat.uid = metadata.uid as i32; 67767b48188Shoumkh kstat.gid = metadata.gid as i32; 67867b48188Shoumkh kstat.rdev = metadata.raw_dev as i64; 6796b4e7a29SLoGin kstat.mode = metadata.mode; 6801496ba7bSLoGin match file.lock().file_type() { 68167b48188Shoumkh FileType::File => kstat.mode.insert(ModeType::S_IFMT), 68267b48188Shoumkh FileType::Dir => kstat.mode.insert(ModeType::S_IFDIR), 68367b48188Shoumkh FileType::BlockDevice => kstat.mode.insert(ModeType::S_IFBLK), 68467b48188Shoumkh FileType::CharDevice => kstat.mode.insert(ModeType::S_IFCHR), 68567b48188Shoumkh FileType::SymLink => kstat.mode.insert(ModeType::S_IFLNK), 68667b48188Shoumkh FileType::Socket => kstat.mode.insert(ModeType::S_IFSOCK), 68767b48188Shoumkh FileType::Pipe => kstat.mode.insert(ModeType::S_IFIFO), 68867b48188Shoumkh } 68967b48188Shoumkh 69067b48188Shoumkh return Ok(kstat); 69167b48188Shoumkh } 6921496ba7bSLoGin 69367b48188Shoumkh pub fn fstat(fd: i32, usr_kstat: *mut PosixKstat) -> Result<usize, SystemError> { 6941496ba7bSLoGin let kstat = Self::do_fstat(fd)?; 69567b48188Shoumkh if usr_kstat.is_null() { 69667b48188Shoumkh return Err(SystemError::EFAULT); 69767b48188Shoumkh } 69867b48188Shoumkh unsafe { 69967b48188Shoumkh *usr_kstat = kstat; 70067b48188Shoumkh } 70167b48188Shoumkh return Ok(0); 70267b48188Shoumkh } 703*2dbef785SGnoCiYeH 704*2dbef785SGnoCiYeH pub fn mknod( 705*2dbef785SGnoCiYeH path_ptr: *const i8, 706*2dbef785SGnoCiYeH mode: ModeType, 707*2dbef785SGnoCiYeH dev_t: DeviceNumber, 708*2dbef785SGnoCiYeH ) -> Result<usize, SystemError> { 709*2dbef785SGnoCiYeH // 安全检验 710*2dbef785SGnoCiYeH let len = unsafe { CStr::from_ptr(path_ptr).to_bytes().len() }; 711*2dbef785SGnoCiYeH let user_buffer = UserBufferReader::new(path_ptr, len, true)?; 712*2dbef785SGnoCiYeH let buf = user_buffer.read_from_user::<u8>(0)?; 713*2dbef785SGnoCiYeH let path = core::str::from_utf8(buf).map_err(|_| SystemError::EINVAL)?; 714*2dbef785SGnoCiYeH 715*2dbef785SGnoCiYeH // 文件名过长 716*2dbef785SGnoCiYeH if path.len() > MAX_PATHLEN as usize { 717*2dbef785SGnoCiYeH return Err(SystemError::ENAMETOOLONG); 718*2dbef785SGnoCiYeH } 719*2dbef785SGnoCiYeH 720*2dbef785SGnoCiYeH let inode: Result<Arc<dyn IndexNode>, SystemError> = ROOT_INODE().lookup(path); 721*2dbef785SGnoCiYeH 722*2dbef785SGnoCiYeH if inode.is_ok() { 723*2dbef785SGnoCiYeH return Err(SystemError::EEXIST); 724*2dbef785SGnoCiYeH } 725*2dbef785SGnoCiYeH 726*2dbef785SGnoCiYeH let (filename, parent_path) = rsplit_path(path); 727*2dbef785SGnoCiYeH 728*2dbef785SGnoCiYeH // 查找父目录 729*2dbef785SGnoCiYeH let parent_inode: Arc<dyn IndexNode> = ROOT_INODE().lookup(parent_path.unwrap_or("/"))?; 730*2dbef785SGnoCiYeH // 创建nod 731*2dbef785SGnoCiYeH parent_inode.mknod(filename, mode, dev_t)?; 732*2dbef785SGnoCiYeH 733*2dbef785SGnoCiYeH return Ok(0); 734*2dbef785SGnoCiYeH } 73567b48188Shoumkh } 736cde5492fSlogin #[repr(C)] 737cde5492fSlogin #[derive(Debug, Clone, Copy)] 738cde5492fSlogin pub struct IoVec { 739cde5492fSlogin /// 缓冲区的起始地址 740cde5492fSlogin pub iov_base: *mut u8, 741cde5492fSlogin /// 缓冲区的长度 742cde5492fSlogin pub iov_len: usize, 743cde5492fSlogin } 744cde5492fSlogin 745cde5492fSlogin /// 用于存储多个来自用户空间的IoVec 746cde5492fSlogin /// 747cde5492fSlogin /// 由于目前内核中的文件系统还不支持分散读写,所以暂时只支持将用户空间的IoVec聚合成一个缓冲区,然后进行操作。 748cde5492fSlogin /// TODO:支持分散读写 749cde5492fSlogin #[derive(Debug)] 750cde5492fSlogin pub struct IoVecs(Vec<&'static mut [u8]>); 751cde5492fSlogin 752cde5492fSlogin impl IoVecs { 753cde5492fSlogin /// 从用户空间的IoVec中构造IoVecs 754cde5492fSlogin /// 755cde5492fSlogin /// @param iov 用户空间的IoVec 756cde5492fSlogin /// @param iovcnt 用户空间的IoVec的数量 757cde5492fSlogin /// @param readv 是否为readv系统调用 758cde5492fSlogin /// 759cde5492fSlogin /// @return 构造成功返回IoVecs,否则返回错误码 760cde5492fSlogin pub unsafe fn from_user( 761cde5492fSlogin iov: *const IoVec, 762cde5492fSlogin iovcnt: usize, 763cde5492fSlogin _readv: bool, 764cde5492fSlogin ) -> Result<Self, SystemError> { 765cde5492fSlogin // 检查iov指针所在空间是否合法 766cde5492fSlogin if !verify_area( 767cde5492fSlogin iov as usize as u64, 768cde5492fSlogin (iovcnt * core::mem::size_of::<IoVec>()) as u64, 769cde5492fSlogin ) { 770cde5492fSlogin return Err(SystemError::EFAULT); 771cde5492fSlogin } 772cde5492fSlogin 773cde5492fSlogin // 将用户空间的IoVec转换为引用(注意:这里的引用是静态的,因为用户空间的IoVec不会被释放) 774cde5492fSlogin let iovs: &[IoVec] = core::slice::from_raw_parts(iov, iovcnt); 775cde5492fSlogin 776cde5492fSlogin let mut slices: Vec<&mut [u8]> = vec![]; 777cde5492fSlogin slices.reserve(iovs.len()); 778cde5492fSlogin 779cde5492fSlogin for iov in iovs.iter() { 780cde5492fSlogin if iov.iov_len == 0 { 781cde5492fSlogin continue; 782cde5492fSlogin } 783cde5492fSlogin 784cde5492fSlogin if !verify_area(iov.iov_base as usize as u64, iov.iov_len as u64) { 785cde5492fSlogin return Err(SystemError::EFAULT); 786cde5492fSlogin } 787cde5492fSlogin 788cde5492fSlogin slices.push(core::slice::from_raw_parts_mut(iov.iov_base, iov.iov_len)); 789cde5492fSlogin } 790cde5492fSlogin 791cde5492fSlogin return Ok(Self(slices)); 792cde5492fSlogin } 793cde5492fSlogin 794cde5492fSlogin /// @brief 将IoVecs中的数据聚合到一个缓冲区中 795cde5492fSlogin /// 796cde5492fSlogin /// @return 返回聚合后的缓冲区 797cde5492fSlogin pub fn gather(&self) -> Vec<u8> { 798cde5492fSlogin let mut buf = Vec::new(); 799cde5492fSlogin for slice in self.0.iter() { 800cde5492fSlogin buf.extend_from_slice(slice); 801cde5492fSlogin } 802cde5492fSlogin return buf; 803cde5492fSlogin } 804cde5492fSlogin 805cde5492fSlogin /// @brief 将给定的数据分散写入到IoVecs中 806cde5492fSlogin pub fn scatter(&mut self, data: &[u8]) { 807cde5492fSlogin let mut data: &[u8] = data; 808cde5492fSlogin for slice in self.0.iter_mut() { 809cde5492fSlogin let len = core::cmp::min(slice.len(), data.len()); 810cde5492fSlogin if len == 0 { 811cde5492fSlogin continue; 812cde5492fSlogin } 813cde5492fSlogin 814cde5492fSlogin slice[..len].copy_from_slice(&data[..len]); 815cde5492fSlogin data = &data[len..]; 816cde5492fSlogin } 817cde5492fSlogin } 818cde5492fSlogin 819cde5492fSlogin /// @brief 创建与IoVecs等长的缓冲区 820cde5492fSlogin /// 821cde5492fSlogin /// @param set_len 是否设置返回的Vec的len。 822cde5492fSlogin /// 如果为true,则返回的Vec的len为所有IoVec的长度之和; 823cde5492fSlogin /// 否则返回的Vec的len为0,capacity为所有IoVec的长度之和. 824cde5492fSlogin /// 825cde5492fSlogin /// @return 返回创建的缓冲区 826cde5492fSlogin pub fn new_buf(&self, set_len: bool) -> Vec<u8> { 827cde5492fSlogin let total_len: usize = self.0.iter().map(|slice| slice.len()).sum(); 828cde5492fSlogin let mut buf: Vec<u8> = Vec::with_capacity(total_len); 829cde5492fSlogin 830cde5492fSlogin if set_len { 8317ae679ddSLoGin buf.resize(total_len, 0); 832cde5492fSlogin } 833cde5492fSlogin return buf; 834cde5492fSlogin } 835cde5492fSlogin } 836