1 use core::ffi::c_void; 2 use core::mem::size_of; 3 4 use alloc::string::ToString; 5 use alloc::{string::String, sync::Arc, vec::Vec}; 6 use system_error::SystemError; 7 8 use crate::producefs; 9 use crate::{ 10 driver::base::{block::SeekFrom, device::device_number::DeviceNumber}, 11 filesystem::vfs::{core as Vcore, file::FileDescriptorVec}, 12 kerror, 13 libs::rwlock::RwLockWriteGuard, 14 mm::{verify_area, VirtAddr}, 15 process::ProcessManager, 16 syscall::{ 17 user_access::{self, check_and_clone_cstr, UserBufferWriter}, 18 Syscall, 19 }, 20 time::PosixTimeSpec, 21 }; 22 23 use super::SuperBlock; 24 use super::{ 25 core::{do_mkdir, do_remove_dir, do_unlink_at}, 26 fcntl::{AtFlags, FcntlCommand, FD_CLOEXEC}, 27 file::{File, FileMode}, 28 open::{do_faccessat, do_fchmodat, do_sys_open}, 29 utils::{rsplit_path, user_path_at}, 30 Dirent, FileType, IndexNode, FSMAKER, MAX_PATHLEN, ROOT_INODE, VFS_MAX_FOLLOW_SYMLINK_TIMES, 31 }; 32 // use crate::kdebug; 33 34 pub const SEEK_SET: u32 = 0; 35 pub const SEEK_CUR: u32 = 1; 36 pub const SEEK_END: u32 = 2; 37 pub const SEEK_MAX: u32 = 3; 38 39 bitflags! { 40 /// 文件类型和权限 41 #[repr(C)] 42 pub struct ModeType: u32 { 43 /// 掩码 44 const S_IFMT = 0o0_170_000; 45 /// 文件类型 46 const S_IFSOCK = 0o140000; 47 const S_IFLNK = 0o120000; 48 const S_IFREG = 0o100000; 49 const S_IFBLK = 0o060000; 50 const S_IFDIR = 0o040000; 51 const S_IFCHR = 0o020000; 52 const S_IFIFO = 0o010000; 53 54 const S_ISUID = 0o004000; 55 const S_ISGID = 0o002000; 56 const S_ISVTX = 0o001000; 57 /// 文件用户权限 58 const S_IRWXU = 0o0700; 59 const S_IRUSR = 0o0400; 60 const S_IWUSR = 0o0200; 61 const S_IXUSR = 0o0100; 62 /// 文件组权限 63 const S_IRWXG = 0o0070; 64 const S_IRGRP = 0o0040; 65 const S_IWGRP = 0o0020; 66 const S_IXGRP = 0o0010; 67 /// 文件其他用户权限 68 const S_IRWXO = 0o0007; 69 const S_IROTH = 0o0004; 70 const S_IWOTH = 0o0002; 71 const S_IXOTH = 0o0001; 72 73 /// 0o777 74 const S_IRWXUGO = Self::S_IRWXU.bits | Self::S_IRWXG.bits | Self::S_IRWXO.bits; 75 /// 0o7777 76 const S_IALLUGO = Self::S_ISUID.bits | Self::S_ISGID.bits | Self::S_ISVTX.bits| Self::S_IRWXUGO.bits; 77 /// 0o444 78 const S_IRUGO = Self::S_IRUSR.bits | Self::S_IRGRP.bits | Self::S_IROTH.bits; 79 /// 0o222 80 const S_IWUGO = Self::S_IWUSR.bits | Self::S_IWGRP.bits | Self::S_IWOTH.bits; 81 /// 0o111 82 const S_IXUGO = Self::S_IXUSR.bits | Self::S_IXGRP.bits | Self::S_IXOTH.bits; 83 84 85 } 86 } 87 88 #[repr(C)] 89 #[derive(Clone, Copy)] 90 /// # 文件信息结构体 91 pub struct PosixKstat { 92 /// 硬件设备ID 93 dev_id: u64, 94 /// inode号 95 inode: u64, 96 /// 硬链接数 97 nlink: u64, 98 /// 文件权限 99 mode: ModeType, 100 /// 所有者用户ID 101 uid: i32, 102 /// 所有者组ID 103 gid: i32, 104 /// 设备ID 105 rdev: i64, 106 /// 文件大小 107 size: i64, 108 /// 文件系统块大小 109 blcok_size: i64, 110 /// 分配的512B块数 111 blocks: u64, 112 /// 最后访问时间 113 atime: PosixTimeSpec, 114 /// 最后修改时间 115 mtime: PosixTimeSpec, 116 /// 最后状态变化时间 117 ctime: PosixTimeSpec, 118 /// 用于填充结构体大小的空白数据 119 pub _pad: [i8; 24], 120 } 121 impl PosixKstat { 122 fn new() -> Self { 123 Self { 124 inode: 0, 125 dev_id: 0, 126 mode: ModeType { bits: 0 }, 127 nlink: 0, 128 uid: 0, 129 gid: 0, 130 rdev: 0, 131 size: 0, 132 atime: PosixTimeSpec { 133 tv_sec: 0, 134 tv_nsec: 0, 135 }, 136 mtime: PosixTimeSpec { 137 tv_sec: 0, 138 tv_nsec: 0, 139 }, 140 ctime: PosixTimeSpec { 141 tv_sec: 0, 142 tv_nsec: 0, 143 }, 144 blcok_size: 0, 145 blocks: 0, 146 _pad: Default::default(), 147 } 148 } 149 } 150 151 #[repr(C)] 152 #[derive(Clone, Copy)] 153 /// # 文件信息结构体X 154 pub struct PosixStatx { 155 /* 0x00 */ 156 stx_mask: PosixStatxMask, 157 /// 文件系统块大小 158 stx_blksize: u32, 159 /// Flags conveying information about the file [uncond] 160 stx_attributes: StxAttributes, 161 /* 0x10 */ 162 /// 硬链接数 163 stx_nlink: u32, 164 /// 所有者用户ID 165 stx_uid: u32, 166 /// 所有者组ID 167 stx_gid: u32, 168 /// 文件权限 169 stx_mode: ModeType, 170 171 /* 0x20 */ 172 /// inode号 173 stx_inode: u64, 174 /// 文件大小 175 stx_size: i64, 176 /// 分配的512B块数 177 stx_blocks: u64, 178 /// Mask to show what's supported in stx_attributes 179 stx_attributes_mask: StxAttributes, 180 181 /* 0x40 */ 182 /// 最后访问时间 183 stx_atime: PosixTimeSpec, 184 /// 文件创建时间 185 stx_btime: PosixTimeSpec, 186 /// 最后状态变化时间 187 stx_ctime: PosixTimeSpec, 188 /// 最后修改时间 189 stx_mtime: PosixTimeSpec, 190 191 /* 0x80 */ 192 /// 主设备ID 193 stx_rdev_major: u32, 194 /// 次设备ID 195 stx_rdev_minor: u32, 196 /// 主硬件设备ID 197 stx_dev_major: u32, 198 /// 次硬件设备ID 199 stx_dev_minor: u32, 200 201 /* 0x90 */ 202 stx_mnt_id: u64, 203 stx_dio_mem_align: u32, 204 stx_dio_offset_align: u32, 205 } 206 impl PosixStatx { 207 fn new() -> Self { 208 Self { 209 stx_mask: PosixStatxMask::STATX_BASIC_STATS, 210 stx_blksize: 0, 211 stx_attributes: StxAttributes::STATX_ATTR_APPEND, 212 stx_nlink: 0, 213 stx_uid: 0, 214 stx_gid: 0, 215 stx_mode: ModeType { bits: 0 }, 216 stx_inode: 0, 217 stx_size: 0, 218 stx_blocks: 0, 219 stx_attributes_mask: StxAttributes::STATX_ATTR_APPEND, 220 stx_atime: PosixTimeSpec { 221 tv_sec: 0, 222 tv_nsec: 0, 223 }, 224 stx_btime: PosixTimeSpec { 225 tv_sec: 0, 226 tv_nsec: 0, 227 }, 228 stx_ctime: PosixTimeSpec { 229 tv_sec: 0, 230 tv_nsec: 0, 231 }, 232 stx_mtime: PosixTimeSpec { 233 tv_sec: 0, 234 tv_nsec: 0, 235 }, 236 stx_rdev_major: 0, 237 stx_rdev_minor: 0, 238 stx_dev_major: 0, 239 stx_dev_minor: 0, 240 stx_mnt_id: 0, 241 stx_dio_mem_align: 0, 242 stx_dio_offset_align: 0, 243 } 244 } 245 } 246 247 bitflags! { 248 pub struct PosixStatxMask: u32{ 249 /// Want stx_mode & S_IFMT 250 const STATX_TYPE = 0x00000001; 251 252 /// Want stx_mode & ~S_IFMT 253 const STATX_MODE = 0x00000002; 254 255 /// Want stx_nlink 256 const STATX_NLINK = 0x00000004; 257 258 /// Want stx_uid 259 const STATX_UID = 0x00000008; 260 261 /// Want stx_gid 262 const STATX_GID = 0x00000010; 263 264 /// Want stx_atime 265 const STATX_ATIME = 0x00000020; 266 267 /// Want stx_mtime 268 const STATX_MTIME = 0x00000040; 269 270 /// Want stx_ctime 271 const STATX_CTIME = 0x00000080; 272 273 /// Want stx_ino 274 const STATX_INO = 0x00000100; 275 276 /// Want stx_size 277 const STATX_SIZE = 0x00000200; 278 279 /// Want stx_blocks 280 const STATX_BLOCKS = 0x00000400; 281 282 /// [All of the above] 283 const STATX_BASIC_STATS = 0x000007ff; 284 285 /// Want stx_btime 286 const STATX_BTIME = 0x00000800; 287 288 /// The same as STATX_BASIC_STATS | STATX_BTIME. 289 /// It is deprecated and should not be used. 290 const STATX_ALL = 0x00000fff; 291 292 /// Want stx_mnt_id (since Linux 5.8) 293 const STATX_MNT_ID = 0x00001000; 294 295 /// Want stx_dio_mem_align and stx_dio_offset_align 296 /// (since Linux 6.1; support varies by filesystem) 297 const STATX_DIOALIGN = 0x00002000; 298 299 /// Reserved for future struct statx expansion 300 const STATX_RESERVED = 0x80000000; 301 } 302 } 303 304 bitflags! { 305 pub struct StxAttributes: u64 { 306 /// 文件被文件系统压缩 307 const STATX_ATTR_COMPRESSED = 0x00000004; 308 /// 文件被标记为不可修改 309 const STATX_ATTR_IMMUTABLE = 0x00000010; 310 /// 文件是只追加写入的 311 const STATX_ATTR_APPEND = 0x00000020; 312 /// 文件不会被备份 313 const STATX_ATTR_NODUMP = 0x00000040; 314 /// 文件需要密钥才能在文件系统中解密 315 const STATX_ATTR_ENCRYPTED = 0x00000800; 316 /// 目录是自动挂载触发器 317 const STATX_ATTR_AUTOMOUNT = 0x00001000; 318 /// 目录是挂载点的根目录 319 const STATX_ATTR_MOUNT_ROOT = 0x00002000; 320 /// 文件受到 Verity 保护 321 const STATX_ATTR_VERITY = 0x00100000; 322 /// 文件当前处于 DAX 状态 CPU直接访问 323 const STATX_ATTR_DAX = 0x00200000; 324 } 325 } 326 327 #[repr(C)] 328 #[derive(Debug, Clone, Copy)] 329 pub struct PosixStatfs { 330 f_type: u64, 331 f_bsize: u64, 332 f_blocks: u64, 333 f_bfree: u64, 334 f_bavail: u64, 335 f_files: u64, 336 f_ffree: u64, 337 f_fsid: u64, 338 f_namelen: u64, 339 f_frsize: u64, 340 f_flags: u64, 341 f_spare: [u64; 4], 342 } 343 344 impl From<SuperBlock> for PosixStatfs { 345 fn from(super_block: SuperBlock) -> Self { 346 Self { 347 f_type: super_block.magic.bits, 348 f_bsize: super_block.bsize, 349 f_blocks: super_block.blocks, 350 f_bfree: super_block.bfree, 351 f_bavail: super_block.bavail, 352 f_files: super_block.files, 353 f_ffree: super_block.ffree, 354 f_fsid: super_block.fsid, 355 f_namelen: super_block.namelen, 356 f_frsize: super_block.frsize, 357 f_flags: super_block.flags, 358 f_spare: [0u64; 4], 359 } 360 } 361 } 362 /// 363 /// Arguments for how openat2(2) should open the target path. If only @flags and 364 /// @mode are non-zero, then openat2(2) operates very similarly to openat(2). 365 /// 366 /// However, unlike openat(2), unknown or invalid bits in @flags result in 367 /// -EINVAL rather than being silently ignored. @mode must be zero unless one of 368 /// {O_CREAT, O_TMPFILE} are set. 369 /// 370 /// ## 成员变量 371 /// 372 /// - flags: O_* flags. 373 /// - mode: O_CREAT/O_TMPFILE file mode. 374 /// - resolve: RESOLVE_* flags. 375 #[derive(Debug, Clone, Copy)] 376 #[repr(C)] 377 pub struct PosixOpenHow { 378 pub flags: u64, 379 pub mode: u64, 380 pub resolve: u64, 381 } 382 383 impl PosixOpenHow { 384 #[allow(dead_code)] 385 pub fn new(flags: u64, mode: u64, resolve: u64) -> Self { 386 Self { 387 flags, 388 mode, 389 resolve, 390 } 391 } 392 } 393 394 #[derive(Debug, Clone, Copy)] 395 pub struct OpenHow { 396 pub o_flags: FileMode, 397 pub mode: ModeType, 398 pub resolve: OpenHowResolve, 399 } 400 401 impl OpenHow { 402 pub fn new(mut o_flags: FileMode, mut mode: ModeType, resolve: OpenHowResolve) -> Self { 403 if !o_flags.contains(FileMode::O_CREAT) { 404 mode = ModeType::empty(); 405 } 406 407 if o_flags.contains(FileMode::O_PATH) { 408 o_flags = o_flags.intersection(FileMode::O_PATH_FLAGS); 409 } 410 411 Self { 412 o_flags, 413 mode, 414 resolve, 415 } 416 } 417 } 418 419 impl From<PosixOpenHow> for OpenHow { 420 fn from(posix_open_how: PosixOpenHow) -> Self { 421 let o_flags = FileMode::from_bits_truncate(posix_open_how.flags as u32); 422 let mode = ModeType::from_bits_truncate(posix_open_how.mode as u32); 423 let resolve = OpenHowResolve::from_bits_truncate(posix_open_how.resolve); 424 return Self::new(o_flags, mode, resolve); 425 } 426 } 427 428 bitflags! { 429 pub struct OpenHowResolve: u64{ 430 /// Block mount-point crossings 431 /// (including bind-mounts). 432 const RESOLVE_NO_XDEV = 0x01; 433 434 /// Block traversal through procfs-style 435 /// "magic-links" 436 const RESOLVE_NO_MAGICLINKS = 0x02; 437 438 /// Block traversal through all symlinks 439 /// (implies OEXT_NO_MAGICLINKS) 440 const RESOLVE_NO_SYMLINKS = 0x04; 441 /// Block "lexical" trickery like 442 /// "..", symlinks, and absolute 443 const RESOLVE_BENEATH = 0x08; 444 /// Make all jumps to "/" and ".." 445 /// be scoped inside the dirfd 446 /// (similar to chroot(2)). 447 const RESOLVE_IN_ROOT = 0x10; 448 // Only complete if resolution can be 449 // completed through cached lookup. May 450 // return -EAGAIN if that's not 451 // possible. 452 const RESOLVE_CACHED = 0x20; 453 } 454 } 455 impl Syscall { 456 /// @brief 为当前进程打开一个文件 457 /// 458 /// @param path 文件路径 459 /// @param o_flags 打开文件的标志位 460 /// 461 /// @return 文件描述符编号，或者是错误码 462 pub fn open( 463 path: *const u8, 464 o_flags: u32, 465 mode: u32, 466 follow_symlink: bool, 467 ) -> Result<usize, SystemError> { 468 let path = check_and_clone_cstr(path, Some(MAX_PATHLEN))?; 469 let open_flags: FileMode = FileMode::from_bits(o_flags).ok_or(SystemError::EINVAL)?; 470 let mode = ModeType::from_bits(mode).ok_or(SystemError::EINVAL)?; 471 return do_sys_open( 472 AtFlags::AT_FDCWD.bits(), 473 &path, 474 open_flags, 475 mode, 476 follow_symlink, 477 ); 478 } 479 480 pub fn openat( 481 dirfd: i32, 482 path: *const u8, 483 o_flags: u32, 484 mode: u32, 485 follow_symlink: bool, 486 ) -> Result<usize, SystemError> { 487 let path = check_and_clone_cstr(path, Some(MAX_PATHLEN))?; 488 let open_flags: FileMode = FileMode::from_bits(o_flags).ok_or(SystemError::EINVAL)?; 489 let mode = ModeType::from_bits(mode).ok_or(SystemError::EINVAL)?; 490 return do_sys_open(dirfd, &path, open_flags, mode, follow_symlink); 491 } 492 493 /// @brief 关闭文件 494 /// 495 /// @param fd 文件描述符编号 496 /// 497 /// @return 成功返回0，失败返回错误码 498 pub fn close(fd: usize) -> Result<usize, SystemError> { 499 let binding = ProcessManager::current_pcb().fd_table(); 500 let mut fd_table_guard = binding.write(); 501 502 fd_table_guard.drop_fd(fd as i32).map(|_| 0) 503 } 504 505 /// @brief 发送命令到文件描述符对应的设备， 506 /// 507 /// @param fd 文件描述符编号 508 /// @param cmd 设备相关的请求类型 509 /// 510 /// @return Ok(usize) 成功返回0 511 /// @return Err(SystemError) 读取失败，返回posix错误码 512 pub fn ioctl(fd: usize, cmd: u32, data: usize) -> Result<usize, SystemError> { 513 let binding = ProcessManager::current_pcb().fd_table(); 514 let fd_table_guard = binding.read(); 515 516 let file = fd_table_guard 517 .get_file_by_fd(fd as i32) 518 .ok_or(SystemError::EBADF)?; 519 520 // drop guard 以避免无法调度的问题 521 drop(fd_table_guard); 522 let r = file.inode().ioctl(cmd, data, &file.private_data.lock()); 523 return r; 524 } 525 526 /// @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。 527 /// 528 /// @param fd 文件描述符编号 529 /// @param buf 输出缓冲区 530 /// 531 /// @return Ok(usize) 成功读取的数据的字节数 532 /// @return Err(SystemError) 读取失败，返回posix错误码 533 pub fn read(fd: i32, buf: &mut [u8]) -> Result<usize, SystemError> { 534 let binding = ProcessManager::current_pcb().fd_table(); 535 let fd_table_guard = binding.read(); 536 537 let file = fd_table_guard.get_file_by_fd(fd); 538 if file.is_none() { 539 return Err(SystemError::EBADF); 540 } 541 // drop guard 以避免无法调度的问题 542 drop(fd_table_guard); 543 let file = file.unwrap(); 544 545 return file.read(buf.len(), buf); 546 } 547 548 /// @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。 549 /// 550 /// @param fd 文件描述符编号 551 /// @param buf 输入缓冲区 552 /// 553 /// @return Ok(usize) 成功写入的数据的字节数 554 /// @return Err(SystemError) 写入失败，返回posix错误码 555 pub fn write(fd: i32, buf: &[u8]) -> Result<usize, SystemError> { 556 let binding = ProcessManager::current_pcb().fd_table(); 557 let fd_table_guard = binding.read(); 558 559 let file = fd_table_guard 560 .get_file_by_fd(fd) 561 .ok_or(SystemError::EBADF)?; 562 563 // drop guard 以避免无法调度的问题 564 drop(fd_table_guard); 565 return file.write(buf.len(), buf); 566 } 567 568 /// @brief 调整文件操作指针的位置 569 /// 570 /// @param fd 文件描述符编号 571 /// @param seek 调整的方式 572 /// 573 /// @return Ok(usize) 调整后，文件访问指针相对于文件头部的偏移量 574 /// @return Err(SystemError) 调整失败，返回posix错误码 575 pub fn lseek(fd: i32, offset: i64, seek: u32) -> Result<usize, SystemError> { 576 let seek = match seek { 577 SEEK_SET => Ok(SeekFrom::SeekSet(offset)), 578 SEEK_CUR => Ok(SeekFrom::SeekCurrent(offset)), 579 SEEK_END => Ok(SeekFrom::SeekEnd(offset)), 580 SEEK_MAX => Ok(SeekFrom::SeekEnd(0)), 581 _ => Err(SystemError::EINVAL), 582 }?; 583 584 let binding = ProcessManager::current_pcb().fd_table(); 585 let fd_table_guard = binding.read(); 586 let file = fd_table_guard 587 .get_file_by_fd(fd) 588 .ok_or(SystemError::EBADF)?; 589 590 // drop guard 以避免无法调度的问题 591 drop(fd_table_guard); 592 return file.lseek(seek); 593 } 594 595 /// # sys_pread64 系统调用的实际执行函数 596 /// 597 /// ## 参数 598 /// - `fd`: 文件描述符 599 /// - `buf`: 读出缓冲区 600 /// - `len`: 要读取的字节数 601 /// - `offset`: 文件偏移量 602 pub fn pread(fd: i32, buf: &mut [u8], len: usize, offset: usize) -> Result<usize, SystemError> { 603 let binding = ProcessManager::current_pcb().fd_table(); 604 let fd_table_guard = binding.read(); 605 606 let file = fd_table_guard.get_file_by_fd(fd); 607 if file.is_none() { 608 return Err(SystemError::EBADF); 609 } 610 // drop guard 以避免无法调度的问题 611 drop(fd_table_guard); 612 let file = file.unwrap(); 613 614 return file.pread(offset, len, buf); 615 } 616 617 /// # sys_pwrite64 系统调用的实际执行函数 618 /// 619 /// ## 参数 620 /// - `fd`: 文件描述符 621 /// - `buf`: 写入缓冲区 622 /// - `len`: 要写入的字节数 623 /// - `offset`: 文件偏移量 624 pub fn pwrite(fd: i32, buf: &[u8], len: usize, offset: usize) -> Result<usize, SystemError> { 625 let binding = ProcessManager::current_pcb().fd_table(); 626 let fd_table_guard = binding.read(); 627 628 let file = fd_table_guard.get_file_by_fd(fd); 629 if file.is_none() { 630 return Err(SystemError::EBADF); 631 } 632 // drop guard 以避免无法调度的问题 633 drop(fd_table_guard); 634 let file = file.unwrap(); 635 636 return file.pwrite(offset, len, buf); 637 } 638 639 /// @brief 切换工作目录 640 /// 641 /// @param dest_path 目标路径 642 /// 643 /// @return 返回码 描述 644 /// 0 | 成功 645 /// 646 /// EACCESS | 权限不足 647 /// 648 /// ELOOP | 解析path时遇到路径循环 649 /// 650 /// ENAMETOOLONG | 路径名过长 651 /// 652 /// ENOENT | 目标文件或目录不存在 653 /// 654 /// ENODIR | 检索期间发现非目录项 655 /// 656 /// ENOMEM | 系统内存不足 657 /// 658 /// EFAULT | 错误的地址 659 /// 660 /// ENAMETOOLONG | 路径过长 661 pub fn chdir(path: *const u8) -> Result<usize, SystemError> { 662 if path.is_null() { 663 return Err(SystemError::EFAULT); 664 } 665 666 let path = check_and_clone_cstr(path, Some(MAX_PATHLEN))?; 667 let proc = ProcessManager::current_pcb(); 668 // Copy path to kernel space to avoid some security issues 669 let mut new_path = String::from(""); 670 if !path.is_empty() { 671 let cwd = match path.as_bytes()[0] { 672 b'/' => String::from("/"), 673 _ => proc.basic().cwd(), 674 }; 675 let mut cwd_vec: Vec<_> = cwd.split('/').filter(|&x| !x.is_empty()).collect(); 676 let path_split = path.split('/').filter(|&x| !x.is_empty()); 677 for seg in path_split { 678 if seg == ".." { 679 cwd_vec.pop(); 680 } else if seg == "." { 681 // 当前目录 682 } else { 683 cwd_vec.push(seg); 684 } 685 } 686 //proc.basic().set_path(String::from("")); 687 for seg in cwd_vec { 688 new_path.push('/'); 689 new_path.push_str(seg); 690 } 691 if new_path.is_empty() { 692 new_path = String::from("/"); 693 } 694 } 695 let inode = 696 match ROOT_INODE().lookup_follow_symlink(&new_path, VFS_MAX_FOLLOW_SYMLINK_TIMES) { 697 Err(_) => { 698 return Err(SystemError::ENOENT); 699 } 700 Ok(i) => i, 701 }; 702 let metadata = inode.metadata()?; 703 if metadata.file_type == FileType::Dir { 704 proc.basic_mut().set_cwd(new_path); 705 return Ok(0); 706 } else { 707 return Err(SystemError::ENOTDIR); 708 } 709 } 710 711 /// @brief 获取当前进程的工作目录路径 712 /// 713 /// @param buf 指向缓冲区的指针 714 /// @param size 缓冲区的大小 715 /// 716 /// @return 成功，返回的指针指向包含工作目录路径的字符串 717 /// @return 错误，没有足够的空间 718 pub fn getcwd(buf: &mut [u8]) -> Result<VirtAddr, SystemError> { 719 let proc = ProcessManager::current_pcb(); 720 let cwd = proc.basic().cwd(); 721 722 let cwd_bytes = cwd.as_bytes(); 723 let cwd_len = cwd_bytes.len(); 724 if cwd_len + 1 > buf.len() { 725 return Err(SystemError::ENOMEM); 726 } 727 buf[..cwd_len].copy_from_slice(cwd_bytes); 728 buf[cwd_len] = 0; 729 730 return Ok(VirtAddr::new(buf.as_ptr() as usize)); 731 } 732 733 /// @brief 获取目录中的数据 734 /// 735 /// TODO: 这个函数的语义与Linux不一致，需要修改！！！ 736 /// 737 /// @param fd 文件描述符号 738 /// @param buf 输出缓冲区 739 /// 740 /// @return 成功返回读取的字节数，失败返回错误码 741 pub fn getdents(fd: i32, buf: &mut [u8]) -> Result<usize, SystemError> { 742 let dirent = 743 unsafe { (buf.as_mut_ptr() as *mut Dirent).as_mut() }.ok_or(SystemError::EFAULT)?; 744 745 if fd < 0 || fd as usize > FileDescriptorVec::PROCESS_MAX_FD { 746 return Err(SystemError::EBADF); 747 } 748 749 // 获取fd 750 let binding = ProcessManager::current_pcb().fd_table(); 751 let fd_table_guard = binding.read(); 752 let file = fd_table_guard 753 .get_file_by_fd(fd) 754 .ok_or(SystemError::EBADF)?; 755 756 // drop guard 以避免无法调度的问题 757 drop(fd_table_guard); 758 759 let res = file.readdir(dirent).map(|x| x as usize); 760 761 return res; 762 } 763 764 /// @brief 创建文件夹 765 /// 766 /// @param path(r8) 路径 / mode(r9) 模式 767 /// 768 /// @return uint64_t 负数错误码 / 0表示成功 769 pub fn mkdir(path: *const u8, mode: usize) -> Result<usize, SystemError> { 770 let path = check_and_clone_cstr(path, Some(MAX_PATHLEN))?; 771 return do_mkdir(&path, FileMode::from_bits_truncate(mode as u32)).map(|x| x as usize); 772 } 773 774 /// **创建硬连接的系统调用** 775 /// 776 /// ## 参数 777 /// 778 /// - 'oldfd': 用于解析源文件路径的文件描述符 779 /// - 'old': 源文件路径 780 /// - 'newfd': 用于解析新文件路径的文件描述符 781 /// - 'new': 新文件将创建的路径 782 /// - 'flags': 标志位，仅以位或方式包含AT_EMPTY_PATH和AT_SYMLINK_FOLLOW 783 /// 784 /// 785 pub fn do_linkat( 786 oldfd: i32, 787 old: &str, 788 newfd: i32, 789 new: &str, 790 flags: AtFlags, 791 ) -> Result<usize, SystemError> { 792 // flag包含其他未规定值时返回EINVAL 793 if !(AtFlags::AT_EMPTY_PATH | AtFlags::AT_SYMLINK_FOLLOW).contains(flags) { 794 return Err(SystemError::EINVAL); 795 } 796 // TODO AT_EMPTY_PATH标志启用时，进行调用者CAP_DAC_READ_SEARCH或相似的检查 797 let symlink_times = if flags.contains(AtFlags::AT_SYMLINK_FOLLOW) { 798 0_usize 799 } else { 800 VFS_MAX_FOLLOW_SYMLINK_TIMES 801 }; 802 let pcb = ProcessManager::current_pcb(); 803 804 // 得到源路径的inode 805 let old_inode: Arc<dyn IndexNode> = if old.is_empty() { 806 if flags.contains(AtFlags::AT_EMPTY_PATH) { 807 // 在AT_EMPTY_PATH启用时，old可以为空，old_inode实际为oldfd所指文件，但该文件不能为目录。 808 let binding = pcb.fd_table(); 809 let fd_table_guard = binding.read(); 810 let file = fd_table_guard 811 .get_file_by_fd(oldfd) 812 .ok_or(SystemError::EBADF)?; 813 let old_inode = file.inode(); 814 old_inode 815 } else { 816 return Err(SystemError::ENONET); 817 } 818 } else { 819 let (old_begin_inode, old_remain_path) = user_path_at(&pcb, oldfd, old)?; 820 old_begin_inode.lookup_follow_symlink(&old_remain_path, symlink_times)? 821 }; 822 823 // old_inode为目录时返回EPERM 824 if old_inode.metadata().unwrap().file_type == FileType::Dir { 825 return Err(SystemError::EPERM); 826 } 827 828 // 得到新创建节点的父节点 829 let (new_begin_inode, new_remain_path) = user_path_at(&pcb, newfd, new)?; 830 let (new_name, new_parent_path) = rsplit_path(&new_remain_path); 831 let new_parent = 832 new_begin_inode.lookup_follow_symlink(new_parent_path.unwrap_or("/"), symlink_times)?; 833 834 // 被调用者利用downcast_ref判断两inode是否为同一文件系统 835 return new_parent.link(new_name, &old_inode).map(|_| 0); 836 } 837 838 pub fn link(old: *const u8, new: *const u8) -> Result<usize, SystemError> { 839 let get_path = |cstr: *const u8| -> Result<String, SystemError> { 840 let res = check_and_clone_cstr(cstr, Some(MAX_PATHLEN))?; 841 if res.len() >= MAX_PATHLEN { 842 return Err(SystemError::ENAMETOOLONG); 843 } 844 if res.is_empty() { 845 return Err(SystemError::ENOENT); 846 } 847 Ok(res) 848 }; 849 let old = get_path(old)?; 850 let new = get_path(new)?; 851 return Self::do_linkat( 852 AtFlags::AT_FDCWD.bits(), 853 &old, 854 AtFlags::AT_FDCWD.bits(), 855 &new, 856 AtFlags::empty(), 857 ); 858 } 859 860 pub fn linkat( 861 oldfd: i32, 862 old: *const u8, 863 newfd: i32, 864 new: *const u8, 865 flags: i32, 866 ) -> Result<usize, SystemError> { 867 let old = check_and_clone_cstr(old, Some(MAX_PATHLEN))?; 868 let new = check_and_clone_cstr(new, Some(MAX_PATHLEN))?; 869 if old.len() >= MAX_PATHLEN || new.len() >= MAX_PATHLEN { 870 return Err(SystemError::ENAMETOOLONG); 871 } 872 // old 根据flags & AtFlags::AT_EMPTY_PATH判空 873 if new.is_empty() { 874 return Err(SystemError::ENOENT); 875 } 876 let flags = AtFlags::from_bits(flags).ok_or(SystemError::EINVAL)?; 877 Self::do_linkat(oldfd, &old, newfd, &new, flags) 878 } 879 880 /// **删除文件夹、取消文件的链接、删除文件的系统调用** 881 /// 882 /// ## 参数 883 /// 884 /// - `dirfd`：文件夹的文件描述符.目前暂未实现 885 /// - `pathname`：文件夹的路径 886 /// - `flags`：标志位 887 /// 888 /// 889 pub fn unlinkat(dirfd: i32, path: *const u8, flags: u32) -> Result<usize, SystemError> { 890 let flags = AtFlags::from_bits(flags as i32).ok_or(SystemError::EINVAL)?; 891 892 let path = check_and_clone_cstr(path, Some(MAX_PATHLEN))?; 893 894 if flags.contains(AtFlags::AT_REMOVEDIR) { 895 // kdebug!("rmdir"); 896 match do_remove_dir(dirfd, &path) { 897 Err(err) => { 898 return Err(err); 899 } 900 Ok(_) => { 901 return Ok(0); 902 } 903 } 904 } 905 906 match do_unlink_at(dirfd, &path) { 907 Err(err) => { 908 return Err(err); 909 } 910 Ok(_) => { 911 return Ok(0); 912 } 913 } 914 } 915 916 pub fn rmdir(path: *const u8) -> Result<usize, SystemError> { 917 let path = check_and_clone_cstr(path, Some(MAX_PATHLEN))?; 918 return do_remove_dir(AtFlags::AT_FDCWD.bits(), &path).map(|v| v as usize); 919 } 920 921 pub fn unlink(path: *const u8) -> Result<usize, SystemError> { 922 let path = check_and_clone_cstr(path, Some(MAX_PATHLEN))?; 923 return do_unlink_at(AtFlags::AT_FDCWD.bits(), &path).map(|v| v as usize); 924 } 925 926 /// # 修改文件名 927 /// 928 /// 929 /// ## 参数 930 /// 931 /// - oldfd: 源文件描述符 932 /// - filename_from: 源文件路径 933 /// - newfd: 目标文件描述符 934 /// - filename_to: 目标文件路径 935 /// - flags: 标志位 936 /// 937 /// 938 /// ## 返回值 939 /// - Ok(返回值类型): 返回值的说明 940 /// - Err(错误值类型): 错误的说明 941 /// 942 pub fn do_renameat2( 943 oldfd: i32, 944 filename_from: *const u8, 945 newfd: i32, 946 filename_to: *const u8, 947 _flags: u32, 948 ) -> Result<usize, SystemError> { 949 let filename_from = check_and_clone_cstr(filename_from, Some(MAX_PATHLEN)).unwrap(); 950 let filename_to = check_and_clone_cstr(filename_to, Some(MAX_PATHLEN)).unwrap(); 951 // 文件名过长 952 if filename_from.len() > MAX_PATHLEN || filename_to.len() > MAX_PATHLEN { 953 return Err(SystemError::ENAMETOOLONG); 954 } 955 956 //获取pcb，文件节点 957 let pcb = ProcessManager::current_pcb(); 958 let (_old_inode_begin, old_remain_path) = user_path_at(&pcb, oldfd, &filename_from)?; 959 let (_new_inode_begin, new_remain_path) = user_path_at(&pcb, newfd, &filename_to)?; 960 //获取父目录 961 let (old_filename, old_parent_path) = rsplit_path(&old_remain_path); 962 let old_parent_inode = ROOT_INODE() 963 .lookup_follow_symlink(old_parent_path.unwrap_or("/"), VFS_MAX_FOLLOW_SYMLINK_TIMES)?; 964 let (new_filename, new_parent_path) = rsplit_path(&new_remain_path); 965 let new_parent_inode = ROOT_INODE() 966 .lookup_follow_symlink(new_parent_path.unwrap_or("/"), VFS_MAX_FOLLOW_SYMLINK_TIMES)?; 967 old_parent_inode.move_to(old_filename, &new_parent_inode, new_filename)?; 968 return Ok(0); 969 } 970 971 /// @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 972 pub fn dup(oldfd: i32) -> Result<usize, SystemError> { 973 let binding = ProcessManager::current_pcb().fd_table(); 974 let mut fd_table_guard = binding.write(); 975 976 let old_file = fd_table_guard 977 .get_file_by_fd(oldfd) 978 .ok_or(SystemError::EBADF)?; 979 980 let new_file = old_file.try_clone().ok_or(SystemError::EBADF)?; 981 // dup默认非cloexec 982 new_file.set_close_on_exec(false); 983 // 申请文件描述符，并把文件对象存入其中 984 let res = fd_table_guard.alloc_fd(new_file, None).map(|x| x as usize); 985 return res; 986 } 987 988 /// 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， 989 /// 并返回新复制的文件结构体对应的fd. 990 /// 如果新fd已经打开，则会先关闭新fd. 991 /// 992 /// ## 参数 993 /// 994 /// - `oldfd`：旧文件描述符 995 /// - `newfd`：新文件描述符 996 /// 997 /// ## 返回值 998 /// 999 /// - 成功：新文件描述符 1000 /// - 失败：错误码 1001 pub fn dup2(oldfd: i32, newfd: i32) -> Result<usize, SystemError> { 1002 let binding = ProcessManager::current_pcb().fd_table(); 1003 let mut fd_table_guard = binding.write(); 1004 return Self::do_dup2(oldfd, newfd, &mut fd_table_guard); 1005 } 1006 1007 fn do_dup2( 1008 oldfd: i32, 1009 newfd: i32, 1010 fd_table_guard: &mut RwLockWriteGuard<'_, FileDescriptorVec>, 1011 ) -> Result<usize, SystemError> { 1012 // 确认oldfd, newid是否有效 1013 if !(FileDescriptorVec::validate_fd(oldfd) && FileDescriptorVec::validate_fd(newfd)) { 1014 return Err(SystemError::EBADF); 1015 } 1016 1017 if oldfd == newfd { 1018 // 若oldfd与newfd相等 1019 return Ok(newfd as usize); 1020 } 1021 let new_exists = fd_table_guard.get_file_by_fd(newfd).is_some(); 1022 if new_exists { 1023 // close newfd 1024 if fd_table_guard.drop_fd(newfd).is_err() { 1025 // An I/O error occurred while attempting to close fildes2. 1026 return Err(SystemError::EIO); 1027 } 1028 } 1029 1030 let old_file = fd_table_guard 1031 .get_file_by_fd(oldfd) 1032 .ok_or(SystemError::EBADF)?; 1033 let new_file = old_file.try_clone().ok_or(SystemError::EBADF)?; 1034 // dup2默认非cloexec 1035 new_file.set_close_on_exec(false); 1036 // 申请文件描述符，并把文件对象存入其中 1037 let res = fd_table_guard 1038 .alloc_fd(new_file, Some(newfd)) 1039 .map(|x| x as usize); 1040 return res; 1041 } 1042 1043 /// # fcntl 1044 /// 1045 /// ## 参数 1046 /// 1047 /// - `fd`：文件描述符 1048 /// - `cmd`：命令 1049 /// - `arg`：参数 1050 pub fn fcntl(fd: i32, cmd: FcntlCommand, arg: i32) -> Result<usize, SystemError> { 1051 match cmd { 1052 FcntlCommand::DupFd => { 1053 if arg < 0 || arg as usize >= FileDescriptorVec::PROCESS_MAX_FD { 1054 return Err(SystemError::EBADF); 1055 } 1056 let arg = arg as usize; 1057 for i in arg..FileDescriptorVec::PROCESS_MAX_FD { 1058 let binding = ProcessManager::current_pcb().fd_table(); 1059 let mut fd_table_guard = binding.write(); 1060 if fd_table_guard.get_file_by_fd(i as i32).is_none() { 1061 return Self::do_dup2(fd, i as i32, &mut fd_table_guard); 1062 } 1063 } 1064 return Err(SystemError::EMFILE); 1065 } 1066 FcntlCommand::GetFd => { 1067 // Get file descriptor flags. 1068 let binding = ProcessManager::current_pcb().fd_table(); 1069 let fd_table_guard = binding.read(); 1070 if let Some(file) = fd_table_guard.get_file_by_fd(fd) { 1071 // drop guard 以避免无法调度的问题 1072 drop(fd_table_guard); 1073 1074 if file.close_on_exec() { 1075 return Ok(FD_CLOEXEC as usize); 1076 } 1077 } 1078 return Err(SystemError::EBADF); 1079 } 1080 FcntlCommand::SetFd => { 1081 // Set file descriptor flags. 1082 let binding = ProcessManager::current_pcb().fd_table(); 1083 let fd_table_guard = binding.write(); 1084 1085 if let Some(file) = fd_table_guard.get_file_by_fd(fd) { 1086 // drop guard 以避免无法调度的问题 1087 drop(fd_table_guard); 1088 let arg = arg as u32; 1089 if arg & FD_CLOEXEC != 0 { 1090 file.set_close_on_exec(true); 1091 } else { 1092 file.set_close_on_exec(false); 1093 } 1094 return Ok(0); 1095 } 1096 return Err(SystemError::EBADF); 1097 } 1098 1099 FcntlCommand::GetFlags => { 1100 // Get file status flags. 1101 let binding = ProcessManager::current_pcb().fd_table(); 1102 let fd_table_guard = binding.read(); 1103 1104 if let Some(file) = fd_table_guard.get_file_by_fd(fd) { 1105 // drop guard 以避免无法调度的问题 1106 drop(fd_table_guard); 1107 return Ok(file.mode().bits() as usize); 1108 } 1109 1110 return Err(SystemError::EBADF); 1111 } 1112 FcntlCommand::SetFlags => { 1113 // Set file status flags. 1114 let binding = ProcessManager::current_pcb().fd_table(); 1115 let fd_table_guard = binding.write(); 1116 1117 if let Some(file) = fd_table_guard.get_file_by_fd(fd) { 1118 let arg = arg as u32; 1119 let mode = FileMode::from_bits(arg).ok_or(SystemError::EINVAL)?; 1120 // drop guard 以避免无法调度的问题 1121 drop(fd_table_guard); 1122 file.set_mode(mode)?; 1123 return Ok(0); 1124 } 1125 1126 return Err(SystemError::EBADF); 1127 } 1128 _ => { 1129 // TODO: unimplemented 1130 // 未实现的命令，返回0，不报错。 1131 1132 // kwarn!("fcntl: unimplemented command: {:?}, defaults to 0.", cmd); 1133 return Ok(0); 1134 } 1135 } 1136 } 1137 1138 /// # ftruncate 1139 /// 1140 /// ## 描述 1141 /// 1142 /// 改变文件大小. 1143 /// 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. 1144 /// 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. 1145 /// 1146 /// ## 参数 1147 /// 1148 /// - `fd`：文件描述符 1149 /// - `len`：文件大小 1150 /// 1151 /// ## 返回值 1152 /// 1153 /// 如果成功，返回0，否则返回错误码. 1154 pub fn ftruncate(fd: i32, len: usize) -> Result<usize, SystemError> { 1155 let binding = ProcessManager::current_pcb().fd_table(); 1156 let fd_table_guard = binding.read(); 1157 1158 if let Some(file) = fd_table_guard.get_file_by_fd(fd) { 1159 // drop guard 以避免无法调度的问题 1160 drop(fd_table_guard); 1161 let r = file.ftruncate(len).map(|_| 0); 1162 return r; 1163 } 1164 1165 return Err(SystemError::EBADF); 1166 } 1167 1168 fn do_fstat(fd: i32) -> Result<PosixKstat, SystemError> { 1169 let binding = ProcessManager::current_pcb().fd_table(); 1170 let fd_table_guard = binding.read(); 1171 let file = fd_table_guard 1172 .get_file_by_fd(fd) 1173 .ok_or(SystemError::EBADF)?; 1174 // drop guard 以避免无法调度的问题 1175 drop(fd_table_guard); 1176 1177 let mut kstat = PosixKstat::new(); 1178 // 获取文件信息 1179 let metadata = file.metadata()?; 1180 kstat.size = metadata.size; 1181 kstat.dev_id = metadata.dev_id as u64; 1182 kstat.inode = metadata.inode_id.into() as u64; 1183 kstat.blcok_size = metadata.blk_size as i64; 1184 kstat.blocks = metadata.blocks as u64; 1185 1186 kstat.atime.tv_sec = metadata.atime.tv_sec; 1187 kstat.atime.tv_nsec = metadata.atime.tv_nsec; 1188 kstat.mtime.tv_sec = metadata.mtime.tv_sec; 1189 kstat.mtime.tv_nsec = metadata.mtime.tv_nsec; 1190 kstat.ctime.tv_sec = metadata.ctime.tv_sec; 1191 kstat.ctime.tv_nsec = metadata.ctime.tv_nsec; 1192 1193 kstat.nlink = metadata.nlinks as u64; 1194 kstat.uid = metadata.uid as i32; 1195 kstat.gid = metadata.gid as i32; 1196 kstat.rdev = metadata.raw_dev.data() as i64; 1197 kstat.mode = metadata.mode; 1198 match file.file_type() { 1199 FileType::File => kstat.mode.insert(ModeType::S_IFREG), 1200 FileType::Dir => kstat.mode.insert(ModeType::S_IFDIR), 1201 FileType::BlockDevice => kstat.mode.insert(ModeType::S_IFBLK), 1202 FileType::CharDevice => kstat.mode.insert(ModeType::S_IFCHR), 1203 FileType::SymLink => kstat.mode.insert(ModeType::S_IFLNK), 1204 FileType::Socket => kstat.mode.insert(ModeType::S_IFSOCK), 1205 FileType::Pipe => kstat.mode.insert(ModeType::S_IFIFO), 1206 FileType::KvmDevice => kstat.mode.insert(ModeType::S_IFCHR), 1207 FileType::FramebufferDevice => kstat.mode.insert(ModeType::S_IFCHR), 1208 } 1209 1210 return Ok(kstat); 1211 } 1212 1213 pub fn fstat(fd: i32, usr_kstat: *mut PosixKstat) -> Result<usize, SystemError> { 1214 let mut writer = UserBufferWriter::new(usr_kstat, size_of::<PosixKstat>(), true)?; 1215 let kstat = Self::do_fstat(fd)?; 1216 1217 writer.copy_one_to_user(&kstat, 0)?; 1218 return Ok(0); 1219 } 1220 1221 pub fn stat(path: *const u8, user_kstat: *mut PosixKstat) -> Result<usize, SystemError> { 1222 let fd = Self::open( 1223 path, 1224 FileMode::O_RDONLY.bits(), 1225 ModeType::empty().bits(), 1226 true, 1227 )?; 1228 let r = Self::fstat(fd as i32, user_kstat); 1229 Self::close(fd).ok(); 1230 return r; 1231 } 1232 1233 pub fn lstat(path: *const u8, user_kstat: *mut PosixKstat) -> Result<usize, SystemError> { 1234 let fd = Self::open( 1235 path, 1236 FileMode::O_RDONLY.bits(), 1237 ModeType::empty().bits(), 1238 false, 1239 )?; 1240 let r = Self::fstat(fd as i32, user_kstat); 1241 Self::close(fd).ok(); 1242 return r; 1243 } 1244 1245 pub fn statfs(path: *const u8, user_statfs: *mut PosixStatfs) -> Result<usize, SystemError> { 1246 let mut writer = UserBufferWriter::new(user_statfs, size_of::<PosixStatfs>(), true)?; 1247 let fd = Self::open( 1248 path, 1249 FileMode::O_RDONLY.bits(), 1250 ModeType::empty().bits(), 1251 true, 1252 )?; 1253 let path = check_and_clone_cstr(path, Some(MAX_PATHLEN)).unwrap(); 1254 let pcb = ProcessManager::current_pcb(); 1255 let (_inode_begin, remain_path) = user_path_at(&pcb, fd as i32, &path)?; 1256 let inode = ROOT_INODE().lookup_follow_symlink(&remain_path, MAX_PATHLEN)?; 1257 let statfs = PosixStatfs::from(inode.fs().super_block()); 1258 writer.copy_one_to_user(&statfs, 0)?; 1259 return Ok(0); 1260 } 1261 1262 pub fn fstatfs(fd: i32, user_statfs: *mut PosixStatfs) -> Result<usize, SystemError> { 1263 let mut writer = UserBufferWriter::new(user_statfs, size_of::<PosixStatfs>(), true)?; 1264 let binding = ProcessManager::current_pcb().fd_table(); 1265 let fd_table_guard = binding.read(); 1266 let file = fd_table_guard 1267 .get_file_by_fd(fd) 1268 .ok_or(SystemError::EBADF)?; 1269 drop(fd_table_guard); 1270 let statfs = PosixStatfs::from(file.inode().fs().super_block()); 1271 writer.copy_one_to_user(&statfs, 0)?; 1272 return Ok(0); 1273 } 1274 1275 pub fn do_statx( 1276 fd: i32, 1277 path: *const u8, 1278 flags: u32, 1279 mask: u32, 1280 usr_kstat: *mut PosixStatx, 1281 ) -> Result<usize, SystemError> { 1282 if usr_kstat.is_null() { 1283 return Err(SystemError::EFAULT); 1284 } 1285 1286 let mask = PosixStatxMask::from_bits_truncate(mask); 1287 1288 if mask.contains(PosixStatxMask::STATX_RESERVED) { 1289 return Err(SystemError::ENAVAIL); 1290 } 1291 1292 let flags = FileMode::from_bits_truncate(flags); 1293 let ofd = Self::open(path, flags.bits(), ModeType::empty().bits, true)?; 1294 1295 let binding = ProcessManager::current_pcb().fd_table(); 1296 let fd_table_guard = binding.read(); 1297 let file = fd_table_guard 1298 .get_file_by_fd(ofd as i32) 1299 .ok_or(SystemError::EBADF)?; 1300 // drop guard 以避免无法调度的问题 1301 drop(fd_table_guard); 1302 let mut writer = UserBufferWriter::new(usr_kstat, size_of::<PosixStatx>(), true)?; 1303 let mut tmp: PosixStatx = PosixStatx::new(); 1304 // 获取文件信息 1305 let metadata = file.metadata()?; 1306 1307 tmp.stx_mask |= PosixStatxMask::STATX_BASIC_STATS; 1308 tmp.stx_blksize = metadata.blk_size as u32; 1309 if mask.contains(PosixStatxMask::STATX_MODE) || mask.contains(PosixStatxMask::STATX_TYPE) { 1310 tmp.stx_mode = metadata.mode; 1311 } 1312 if mask.contains(PosixStatxMask::STATX_NLINK) { 1313 tmp.stx_nlink = metadata.nlinks as u32; 1314 } 1315 if mask.contains(PosixStatxMask::STATX_UID) { 1316 tmp.stx_uid = metadata.uid as u32; 1317 } 1318 if mask.contains(PosixStatxMask::STATX_GID) { 1319 tmp.stx_gid = metadata.gid as u32; 1320 } 1321 if mask.contains(PosixStatxMask::STATX_ATIME) { 1322 tmp.stx_atime.tv_sec = metadata.atime.tv_sec; 1323 tmp.stx_atime.tv_nsec = metadata.atime.tv_nsec; 1324 } 1325 if mask.contains(PosixStatxMask::STATX_MTIME) { 1326 tmp.stx_mtime.tv_sec = metadata.ctime.tv_sec; 1327 tmp.stx_mtime.tv_nsec = metadata.ctime.tv_nsec; 1328 } 1329 if mask.contains(PosixStatxMask::STATX_CTIME) { 1330 // ctime是文件上次修改状态的时间 1331 tmp.stx_ctime.tv_sec = metadata.mtime.tv_sec; 1332 tmp.stx_ctime.tv_nsec = metadata.mtime.tv_nsec; 1333 } 1334 if mask.contains(PosixStatxMask::STATX_INO) { 1335 tmp.stx_inode = metadata.inode_id.into() as u64; 1336 } 1337 if mask.contains(PosixStatxMask::STATX_SIZE) { 1338 tmp.stx_size = metadata.size; 1339 } 1340 if mask.contains(PosixStatxMask::STATX_BLOCKS) { 1341 tmp.stx_blocks = metadata.blocks as u64; 1342 } 1343 1344 if mask.contains(PosixStatxMask::STATX_BTIME) { 1345 // btime是文件创建时间 1346 tmp.stx_btime.tv_sec = metadata.ctime.tv_sec; 1347 tmp.stx_btime.tv_nsec = metadata.ctime.tv_nsec; 1348 } 1349 if mask.contains(PosixStatxMask::STATX_ALL) { 1350 tmp.stx_attributes = StxAttributes::STATX_ATTR_APPEND; 1351 tmp.stx_attributes_mask |= 1352 StxAttributes::STATX_ATTR_AUTOMOUNT | StxAttributes::STATX_ATTR_DAX; 1353 tmp.stx_dev_major = metadata.dev_id as u32; 1354 tmp.stx_dev_minor = metadata.dev_id as u32; // 1355 tmp.stx_rdev_major = metadata.raw_dev.data(); 1356 tmp.stx_rdev_minor = metadata.raw_dev.data(); 1357 } 1358 if mask.contains(PosixStatxMask::STATX_MNT_ID) { 1359 tmp.stx_mnt_id = 0; 1360 } 1361 if mask.contains(PosixStatxMask::STATX_DIOALIGN) { 1362 tmp.stx_dio_mem_align = 0; 1363 tmp.stx_dio_offset_align = 0; 1364 } 1365 1366 match file.file_type() { 1367 FileType::File => tmp.stx_mode.insert(ModeType::S_IFREG), 1368 FileType::Dir => tmp.stx_mode.insert(ModeType::S_IFDIR), 1369 FileType::BlockDevice => tmp.stx_mode.insert(ModeType::S_IFBLK), 1370 FileType::CharDevice => tmp.stx_mode.insert(ModeType::S_IFCHR), 1371 FileType::SymLink => tmp.stx_mode.insert(ModeType::S_IFLNK), 1372 FileType::Socket => tmp.stx_mode.insert(ModeType::S_IFSOCK), 1373 FileType::Pipe => tmp.stx_mode.insert(ModeType::S_IFIFO), 1374 FileType::KvmDevice => tmp.stx_mode.insert(ModeType::S_IFCHR), 1375 FileType::FramebufferDevice => tmp.stx_mode.insert(ModeType::S_IFCHR), 1376 } 1377 1378 writer.copy_one_to_user(&tmp, 0)?; 1379 Self::close(fd as usize).ok(); 1380 return Ok(0); 1381 } 1382 1383 pub fn mknod( 1384 path: *const u8, 1385 mode: ModeType, 1386 dev_t: DeviceNumber, 1387 ) -> Result<usize, SystemError> { 1388 let path = check_and_clone_cstr(path, Some(MAX_PATHLEN))?; 1389 let path = path.as_str().trim(); 1390 1391 let inode: Result<Arc<dyn IndexNode>, SystemError> = 1392 ROOT_INODE().lookup_follow_symlink(path, VFS_MAX_FOLLOW_SYMLINK_TIMES); 1393 1394 if inode.is_ok() { 1395 return Err(SystemError::EEXIST); 1396 } 1397 1398 let (filename, parent_path) = rsplit_path(path); 1399 1400 // 查找父目录 1401 let parent_inode: Arc<dyn IndexNode> = ROOT_INODE() 1402 .lookup_follow_symlink(parent_path.unwrap_or("/"), VFS_MAX_FOLLOW_SYMLINK_TIMES)?; 1403 // 创建nod 1404 parent_inode.mknod(filename, mode, dev_t)?; 1405 1406 return Ok(0); 1407 } 1408 1409 pub fn writev(fd: i32, iov: usize, count: usize) -> Result<usize, SystemError> { 1410 // IoVecs会进行用户态检验 1411 let iovecs = unsafe { IoVecs::from_user(iov as *const IoVec, count, false) }?; 1412 1413 let data = iovecs.gather(); 1414 1415 Self::write(fd, &data) 1416 } 1417 1418 pub fn readv(fd: i32, iov: usize, count: usize) -> Result<usize, SystemError> { 1419 // IoVecs会进行用户态检验 1420 let mut iovecs = unsafe { IoVecs::from_user(iov as *const IoVec, count, true) }?; 1421 1422 let mut data = vec![0; iovecs.0.iter().map(|x| x.len()).sum()]; 1423 1424 let len = Self::read(fd, &mut data)?; 1425 1426 iovecs.scatter(&data[..len]); 1427 1428 return Ok(len); 1429 } 1430 1431 pub fn readlink_at( 1432 dirfd: i32, 1433 path: *const u8, 1434 user_buf: *mut u8, 1435 buf_size: usize, 1436 ) -> Result<usize, SystemError> { 1437 let path = check_and_clone_cstr(path, Some(MAX_PATHLEN))?; 1438 let path = path.as_str().trim(); 1439 let mut user_buf = UserBufferWriter::new(user_buf, buf_size, true)?; 1440 1441 let (inode, path) = user_path_at(&ProcessManager::current_pcb(), dirfd, path)?; 1442 1443 let inode = inode.lookup(path.as_str())?; 1444 if inode.metadata()?.file_type != FileType::SymLink { 1445 return Err(SystemError::EINVAL); 1446 } 1447 1448 let ubuf = user_buf.buffer::<u8>(0).unwrap(); 1449 1450 let file = File::new(inode, FileMode::O_RDONLY)?; 1451 1452 let len = file.read(buf_size, ubuf)?; 1453 1454 return Ok(len); 1455 } 1456 1457 pub fn readlink( 1458 path: *const u8, 1459 user_buf: *mut u8, 1460 buf_size: usize, 1461 ) -> Result<usize, SystemError> { 1462 return Self::readlink_at(AtFlags::AT_FDCWD.bits(), path, user_buf, buf_size); 1463 } 1464 1465 pub fn access(pathname: *const u8, mode: u32) -> Result<usize, SystemError> { 1466 return do_faccessat( 1467 AtFlags::AT_FDCWD.bits(), 1468 pathname, 1469 ModeType::from_bits(mode).ok_or(SystemError::EINVAL)?, 1470 0, 1471 ); 1472 } 1473 1474 pub fn faccessat2( 1475 dirfd: i32, 1476 pathname: *const u8, 1477 mode: u32, 1478 flags: u32, 1479 ) -> Result<usize, SystemError> { 1480 return do_faccessat( 1481 dirfd, 1482 pathname, 1483 ModeType::from_bits(mode).ok_or(SystemError::EINVAL)?, 1484 flags, 1485 ); 1486 } 1487 1488 pub fn chmod(pathname: *const u8, mode: u32) -> Result<usize, SystemError> { 1489 return do_fchmodat( 1490 AtFlags::AT_FDCWD.bits(), 1491 pathname, 1492 ModeType::from_bits(mode).ok_or(SystemError::EINVAL)?, 1493 ); 1494 } 1495 1496 pub fn fchmodat(dirfd: i32, pathname: *const u8, mode: u32) -> Result<usize, SystemError> { 1497 return do_fchmodat( 1498 dirfd, 1499 pathname, 1500 ModeType::from_bits(mode).ok_or(SystemError::EINVAL)?, 1501 ); 1502 } 1503 1504 pub fn fchmod(fd: i32, mode: u32) -> Result<usize, SystemError> { 1505 let _mode = ModeType::from_bits(mode).ok_or(SystemError::EINVAL)?; 1506 let binding = ProcessManager::current_pcb().fd_table(); 1507 let fd_table_guard = binding.read(); 1508 let _file = fd_table_guard 1509 .get_file_by_fd(fd) 1510 .ok_or(SystemError::EBADF)?; 1511 1512 // fchmod没完全实现，因此不修改文件的权限 1513 // todo: 实现fchmod 1514 kwarn!("fchmod not fully implemented"); 1515 return Ok(0); 1516 } 1517 /// #挂载文件系统 1518 /// 1519 /// 用于挂载文件系统,目前仅支持ramfs挂载 1520 /// 1521 /// ## 参数: 1522 /// 1523 /// - source 挂载设备(暂时不支持) 1524 /// - target 挂载目录 1525 /// - filesystemtype 文件系统 1526 /// - mountflags 挂载选项（暂未实现） 1527 /// - data 带数据挂载 1528 /// 1529 /// ## 返回值 1530 /// - Ok(0): 挂载成功 1531 /// - Err(SystemError) :挂载过程中出错 1532 pub fn mount( 1533 _source: *const u8, 1534 target: *const u8, 1535 filesystemtype: *const u8, 1536 _mountflags: usize, 1537 _data: *const c_void, 1538 ) -> Result<usize, SystemError> { 1539 let target = user_access::check_and_clone_cstr(target, Some(MAX_PATHLEN))?; 1540 1541 let filesystemtype = user_access::check_and_clone_cstr(filesystemtype, Some(MAX_PATHLEN))?; 1542 1543 let filesystemtype = producefs!(FSMAKER, filesystemtype)?; 1544 1545 return Vcore::do_mount(filesystemtype, target.to_string().as_str()); 1546 } 1547 1548 // 想法：可以在VFS中实现一个文件系统分发器，流程如下： 1549 // 1. 接受从上方传来的文件类型字符串 1550 // 2. 将传入值与启动时准备好的字符串数组逐个比较（probe） 1551 // 3. 直接在函数内调用构造方法并直接返回文件系统对象 1552 } 1553 1554 #[repr(C)] 1555 #[derive(Debug, Clone, Copy)] 1556 pub struct IoVec { 1557 /// 缓冲区的起始地址 1558 pub iov_base: *mut u8, 1559 /// 缓冲区的长度 1560 pub iov_len: usize, 1561 } 1562 1563 /// 用于存储多个来自用户空间的IoVec 1564 /// 1565 /// 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。 1566 /// TODO：支持分散读写 1567 #[derive(Debug)] 1568 pub struct IoVecs(Vec<&'static mut [u8]>); 1569 1570 impl IoVecs { 1571 /// 从用户空间的IoVec中构造IoVecs 1572 /// 1573 /// @param iov 用户空间的IoVec 1574 /// @param iovcnt 用户空间的IoVec的数量 1575 /// @param readv 是否为readv系统调用 1576 /// 1577 /// @return 构造成功返回IoVecs，否则返回错误码 1578 pub unsafe fn from_user( 1579 iov: *const IoVec, 1580 iovcnt: usize, 1581 _readv: bool, 1582 ) -> Result<Self, SystemError> { 1583 // 检查iov指针所在空间是否合法 1584 verify_area( 1585 VirtAddr::new(iov as usize), 1586 iovcnt * core::mem::size_of::<IoVec>(), 1587 ) 1588 .map_err(|_| SystemError::EFAULT)?; 1589 1590 // 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） 1591 let iovs: &[IoVec] = core::slice::from_raw_parts(iov, iovcnt); 1592 1593 let mut slices: Vec<&mut [u8]> = vec![]; 1594 slices.reserve(iovs.len()); 1595 1596 for iov in iovs.iter() { 1597 if iov.iov_len == 0 { 1598 continue; 1599 } 1600 1601 verify_area( 1602 VirtAddr::new(iov.iov_base as usize), 1603 iovcnt * core::mem::size_of::<IoVec>(), 1604 ) 1605 .map_err(|_| SystemError::EFAULT)?; 1606 1607 slices.push(core::slice::from_raw_parts_mut(iov.iov_base, iov.iov_len)); 1608 } 1609 1610 return Ok(Self(slices)); 1611 } 1612 1613 /// @brief 将IoVecs中的数据聚合到一个缓冲区中 1614 /// 1615 /// @return 返回聚合后的缓冲区 1616 pub fn gather(&self) -> Vec<u8> { 1617 let mut buf = Vec::new(); 1618 for slice in self.0.iter() { 1619 buf.extend_from_slice(slice); 1620 } 1621 return buf; 1622 } 1623 1624 /// @brief 将给定的数据分散写入到IoVecs中 1625 pub fn scatter(&mut self, data: &[u8]) { 1626 let mut data: &[u8] = data; 1627 for slice in self.0.iter_mut() { 1628 let len = core::cmp::min(slice.len(), data.len()); 1629 if len == 0 { 1630 continue; 1631 } 1632 1633 slice[..len].copy_from_slice(&data[..len]); 1634 data = &data[len..]; 1635 } 1636 } 1637 1638 /// @brief 创建与IoVecs等长的缓冲区 1639 /// 1640 /// @param set_len 是否设置返回的Vec的len。 1641 /// 如果为true，则返回的Vec的len为所有IoVec的长度之和; 1642 /// 否则返回的Vec的len为0，capacity为所有IoVec的长度之和. 1643 /// 1644 /// @return 返回创建的缓冲区 1645 pub fn new_buf(&self, set_len: bool) -> Vec<u8> { 1646 let total_len: usize = self.0.iter().map(|slice| slice.len()).sum(); 1647 let mut buf: Vec<u8> = Vec::with_capacity(total_len); 1648 1649 if set_len { 1650 buf.resize(total_len, 0); 1651 } 1652 return buf; 1653 } 1654 } 1655