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 log::warn; 7 use system_error::SystemError; 8 9 use crate::producefs; 10 use crate::syscall::user_access::UserBufferReader; 11 use crate::{ 12 driver::base::{block::SeekFrom, device::device_number::DeviceNumber}, 13 filesystem::vfs::{core as Vcore, file::FileDescriptorVec}, 14 libs::rwlock::RwLockWriteGuard, 15 mm::{verify_area, VirtAddr}, 16 process::ProcessManager, 17 syscall::{ 18 user_access::{self, check_and_clone_cstr, UserBufferWriter}, 19 Syscall, 20 }, 21 time::{syscall::PosixTimeval, PosixTimeSpec}, 22 }; 23 24 use super::{ 25 core::{do_mkdir_at, 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, do_utimensat, do_utimes}, 29 utils::{rsplit_path, user_path_at}, 30 Dirent, FileType, IndexNode, SuperBlock, FSMAKER, MAX_PATHLEN, ROOT_INODE, 31 VFS_MAX_FOLLOW_SYMLINK_TIMES, 32 }; 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 bitflags! { 328 pub struct UtimensFlags: u32 { 329 /// 不需要解释符号链接 330 const AT_SYMLINK_NOFOLLOW = 0x100; 331 } 332 } 333 334 #[repr(C)] 335 #[derive(Debug, Clone, Copy)] 336 pub struct PosixStatfs { 337 f_type: u64, 338 f_bsize: u64, 339 f_blocks: u64, 340 f_bfree: u64, 341 f_bavail: u64, 342 f_files: u64, 343 f_ffree: u64, 344 f_fsid: u64, 345 f_namelen: u64, 346 f_frsize: u64, 347 f_flags: u64, 348 f_spare: [u64; 4], 349 } 350 351 impl From<SuperBlock> for PosixStatfs { 352 fn from(super_block: SuperBlock) -> Self { 353 Self { 354 f_type: super_block.magic.bits, 355 f_bsize: super_block.bsize, 356 f_blocks: super_block.blocks, 357 f_bfree: super_block.bfree, 358 f_bavail: super_block.bavail, 359 f_files: super_block.files, 360 f_ffree: super_block.ffree, 361 f_fsid: super_block.fsid, 362 f_namelen: super_block.namelen, 363 f_frsize: super_block.frsize, 364 f_flags: super_block.flags, 365 f_spare: [0u64; 4], 366 } 367 } 368 } 369 /// 370 /// Arguments for how openat2(2) should open the target path. If only @flags and 371 /// @mode are non-zero, then openat2(2) operates very similarly to openat(2). 372 /// 373 /// However, unlike openat(2), unknown or invalid bits in @flags result in 374 /// -EINVAL rather than being silently ignored. @mode must be zero unless one of 375 /// {O_CREAT, O_TMPFILE} are set. 376 /// 377 /// ## 成员变量 378 /// 379 /// - flags: O_* flags. 380 /// - mode: O_CREAT/O_TMPFILE file mode. 381 /// - resolve: RESOLVE_* flags. 382 #[derive(Debug, Clone, Copy)] 383 #[repr(C)] 384 pub struct PosixOpenHow { 385 pub flags: u64, 386 pub mode: u64, 387 pub resolve: u64, 388 } 389 390 impl PosixOpenHow { 391 #[allow(dead_code)] 392 pub fn new(flags: u64, mode: u64, resolve: u64) -> Self { 393 Self { 394 flags, 395 mode, 396 resolve, 397 } 398 } 399 } 400 401 #[derive(Debug, Clone, Copy)] 402 pub struct OpenHow { 403 pub o_flags: FileMode, 404 pub mode: ModeType, 405 pub resolve: OpenHowResolve, 406 } 407 408 impl OpenHow { 409 pub fn new(mut o_flags: FileMode, mut mode: ModeType, resolve: OpenHowResolve) -> Self { 410 if !o_flags.contains(FileMode::O_CREAT) { 411 mode = ModeType::empty(); 412 } 413 414 if o_flags.contains(FileMode::O_PATH) { 415 o_flags = o_flags.intersection(FileMode::O_PATH_FLAGS); 416 } 417 418 Self { 419 o_flags, 420 mode, 421 resolve, 422 } 423 } 424 } 425 426 impl From<PosixOpenHow> for OpenHow { 427 fn from(posix_open_how: PosixOpenHow) -> Self { 428 let o_flags = FileMode::from_bits_truncate(posix_open_how.flags as u32); 429 let mode = ModeType::from_bits_truncate(posix_open_how.mode as u32); 430 let resolve = OpenHowResolve::from_bits_truncate(posix_open_how.resolve); 431 return Self::new(o_flags, mode, resolve); 432 } 433 } 434 435 bitflags! { 436 pub struct OpenHowResolve: u64{ 437 /// Block mount-point crossings 438 /// (including bind-mounts). 439 const RESOLVE_NO_XDEV = 0x01; 440 441 /// Block traversal through procfs-style 442 /// "magic-links" 443 const RESOLVE_NO_MAGICLINKS = 0x02; 444 445 /// Block traversal through all symlinks 446 /// (implies OEXT_NO_MAGICLINKS) 447 const RESOLVE_NO_SYMLINKS = 0x04; 448 /// Block "lexical" trickery like 449 /// "..", symlinks, and absolute 450 const RESOLVE_BENEATH = 0x08; 451 /// Make all jumps to "/" and ".." 452 /// be scoped inside the dirfd 453 /// (similar to chroot(2)). 454 const RESOLVE_IN_ROOT = 0x10; 455 // Only complete if resolution can be 456 // completed through cached lookup. May 457 // return -EAGAIN if that's not 458 // possible. 459 const RESOLVE_CACHED = 0x20; 460 } 461 } 462 463 bitflags! { 464 pub struct UmountFlag: i32 { 465 const DEFAULT = 0; /* Default call to umount. */ 466 const MNT_FORCE = 1; /* Force unmounting. */ 467 const MNT_DETACH = 2; /* Just detach from the tree. */ 468 const MNT_EXPIRE = 4; /* Mark for expiry. */ 469 const UMOUNT_NOFOLLOW = 8; /* Don't follow symlink on umount. */ 470 } 471 } 472 473 impl Syscall { 474 /// @brief 为当前进程打开一个文件 475 /// 476 /// @param path 文件路径 477 /// @param o_flags 打开文件的标志位 478 /// 479 /// @return 文件描述符编号，或者是错误码 480 pub fn open( 481 path: *const u8, 482 o_flags: u32, 483 mode: u32, 484 follow_symlink: bool, 485 ) -> Result<usize, SystemError> { 486 let path = check_and_clone_cstr(path, Some(MAX_PATHLEN))?; 487 let open_flags: FileMode = FileMode::from_bits(o_flags).ok_or(SystemError::EINVAL)?; 488 let mode = ModeType::from_bits(mode).ok_or(SystemError::EINVAL)?; 489 return do_sys_open( 490 AtFlags::AT_FDCWD.bits(), 491 &path, 492 open_flags, 493 mode, 494 follow_symlink, 495 ); 496 } 497 498 pub fn openat( 499 dirfd: i32, 500 path: *const u8, 501 o_flags: u32, 502 mode: u32, 503 follow_symlink: bool, 504 ) -> Result<usize, SystemError> { 505 let path = check_and_clone_cstr(path, Some(MAX_PATHLEN))?; 506 let open_flags: FileMode = FileMode::from_bits(o_flags).ok_or(SystemError::EINVAL)?; 507 let mode = ModeType::from_bits(mode).ok_or(SystemError::EINVAL)?; 508 return do_sys_open(dirfd, &path, open_flags, mode, follow_symlink); 509 } 510 511 /// @brief 关闭文件 512 /// 513 /// @param fd 文件描述符编号 514 /// 515 /// @return 成功返回0，失败返回错误码 516 pub fn close(fd: usize) -> Result<usize, SystemError> { 517 let binding = ProcessManager::current_pcb().fd_table(); 518 let mut fd_table_guard = binding.write(); 519 520 fd_table_guard.drop_fd(fd as i32).map(|_| 0) 521 } 522 523 /// @brief 发送命令到文件描述符对应的设备， 524 /// 525 /// @param fd 文件描述符编号 526 /// @param cmd 设备相关的请求类型 527 /// 528 /// @return Ok(usize) 成功返回0 529 /// @return Err(SystemError) 读取失败，返回posix错误码 530 pub fn ioctl(fd: usize, cmd: u32, data: usize) -> Result<usize, SystemError> { 531 let binding = ProcessManager::current_pcb().fd_table(); 532 let fd_table_guard = binding.read(); 533 534 let file = fd_table_guard 535 .get_file_by_fd(fd as i32) 536 .ok_or(SystemError::EBADF)?; 537 538 // drop guard 以避免无法调度的问题 539 drop(fd_table_guard); 540 let r = file.inode().ioctl(cmd, data, &file.private_data.lock()); 541 return r; 542 } 543 544 /// @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。 545 /// 546 /// @param fd 文件描述符编号 547 /// @param buf 输出缓冲区 548 /// 549 /// @return Ok(usize) 成功读取的数据的字节数 550 /// @return Err(SystemError) 读取失败，返回posix错误码 551 pub fn read(fd: i32, buf: &mut [u8]) -> Result<usize, SystemError> { 552 let binding = ProcessManager::current_pcb().fd_table(); 553 let fd_table_guard = binding.read(); 554 555 let file = fd_table_guard.get_file_by_fd(fd); 556 if file.is_none() { 557 return Err(SystemError::EBADF); 558 } 559 // drop guard 以避免无法调度的问题 560 drop(fd_table_guard); 561 let file = file.unwrap(); 562 563 return file.read(buf.len(), buf); 564 } 565 566 /// @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。 567 /// 568 /// @param fd 文件描述符编号 569 /// @param buf 输入缓冲区 570 /// 571 /// @return Ok(usize) 成功写入的数据的字节数 572 /// @return Err(SystemError) 写入失败，返回posix错误码 573 pub fn write(fd: i32, buf: &[u8]) -> Result<usize, SystemError> { 574 let binding = ProcessManager::current_pcb().fd_table(); 575 let fd_table_guard = binding.read(); 576 577 let file = fd_table_guard 578 .get_file_by_fd(fd) 579 .ok_or(SystemError::EBADF)?; 580 581 // drop guard 以避免无法调度的问题 582 drop(fd_table_guard); 583 return file.write(buf.len(), buf); 584 } 585 586 /// @brief 调整文件操作指针的位置 587 /// 588 /// @param fd 文件描述符编号 589 /// @param seek 调整的方式 590 /// 591 /// @return Ok(usize) 调整后，文件访问指针相对于文件头部的偏移量 592 /// @return Err(SystemError) 调整失败，返回posix错误码 593 pub fn lseek(fd: i32, offset: i64, seek: u32) -> Result<usize, SystemError> { 594 let seek = match seek { 595 SEEK_SET => Ok(SeekFrom::SeekSet(offset)), 596 SEEK_CUR => Ok(SeekFrom::SeekCurrent(offset)), 597 SEEK_END => Ok(SeekFrom::SeekEnd(offset)), 598 SEEK_MAX => Ok(SeekFrom::SeekEnd(0)), 599 _ => Err(SystemError::EINVAL), 600 }?; 601 602 let binding = ProcessManager::current_pcb().fd_table(); 603 let fd_table_guard = binding.read(); 604 let file = fd_table_guard 605 .get_file_by_fd(fd) 606 .ok_or(SystemError::EBADF)?; 607 608 // drop guard 以避免无法调度的问题 609 drop(fd_table_guard); 610 return file.lseek(seek); 611 } 612 613 /// # sys_pread64 系统调用的实际执行函数 614 /// 615 /// ## 参数 616 /// - `fd`: 文件描述符 617 /// - `buf`: 读出缓冲区 618 /// - `len`: 要读取的字节数 619 /// - `offset`: 文件偏移量 620 pub fn pread(fd: i32, buf: &mut [u8], len: usize, offset: usize) -> Result<usize, SystemError> { 621 let binding = ProcessManager::current_pcb().fd_table(); 622 let fd_table_guard = binding.read(); 623 624 let file = fd_table_guard.get_file_by_fd(fd); 625 if file.is_none() { 626 return Err(SystemError::EBADF); 627 } 628 // drop guard 以避免无法调度的问题 629 drop(fd_table_guard); 630 let file = file.unwrap(); 631 632 return file.pread(offset, len, buf); 633 } 634 635 /// # sys_pwrite64 系统调用的实际执行函数 636 /// 637 /// ## 参数 638 /// - `fd`: 文件描述符 639 /// - `buf`: 写入缓冲区 640 /// - `len`: 要写入的字节数 641 /// - `offset`: 文件偏移量 642 pub fn pwrite(fd: i32, buf: &[u8], len: usize, offset: usize) -> Result<usize, SystemError> { 643 let binding = ProcessManager::current_pcb().fd_table(); 644 let fd_table_guard = binding.read(); 645 646 let file = fd_table_guard.get_file_by_fd(fd); 647 if file.is_none() { 648 return Err(SystemError::EBADF); 649 } 650 // drop guard 以避免无法调度的问题 651 drop(fd_table_guard); 652 let file = file.unwrap(); 653 654 return file.pwrite(offset, len, buf); 655 } 656 657 /// @brief 切换工作目录 658 /// 659 /// @param dest_path 目标路径 660 /// 661 /// @return 返回码 描述 662 /// 0 | 成功 663 /// 664 /// EACCESS | 权限不足 665 /// 666 /// ELOOP | 解析path时遇到路径循环 667 /// 668 /// ENAMETOOLONG | 路径名过长 669 /// 670 /// ENOENT | 目标文件或目录不存在 671 /// 672 /// ENODIR | 检索期间发现非目录项 673 /// 674 /// ENOMEM | 系统内存不足 675 /// 676 /// EFAULT | 错误的地址 677 /// 678 /// ENAMETOOLONG | 路径过长 679 pub fn chdir(path: *const u8) -> Result<usize, SystemError> { 680 if path.is_null() { 681 return Err(SystemError::EFAULT); 682 } 683 684 let path = check_and_clone_cstr(path, Some(MAX_PATHLEN))?; 685 let proc = ProcessManager::current_pcb(); 686 // Copy path to kernel space to avoid some security issues 687 let mut new_path = String::from(""); 688 if !path.is_empty() { 689 let cwd = match path.as_bytes()[0] { 690 b'/' => String::from("/"), 691 _ => proc.basic().cwd(), 692 }; 693 let mut cwd_vec: Vec<_> = cwd.split('/').filter(|&x| !x.is_empty()).collect(); 694 let path_split = path.split('/').filter(|&x| !x.is_empty()); 695 for seg in path_split { 696 if seg == ".." { 697 cwd_vec.pop(); 698 } else if seg == "." { 699 // 当前目录 700 } else { 701 cwd_vec.push(seg); 702 } 703 } 704 //proc.basic().set_path(String::from("")); 705 for seg in cwd_vec { 706 new_path.push('/'); 707 new_path.push_str(seg); 708 } 709 if new_path.is_empty() { 710 new_path = String::from("/"); 711 } 712 } 713 let inode = 714 match ROOT_INODE().lookup_follow_symlink(&new_path, VFS_MAX_FOLLOW_SYMLINK_TIMES) { 715 Err(_) => { 716 return Err(SystemError::ENOENT); 717 } 718 Ok(i) => i, 719 }; 720 let metadata = inode.metadata()?; 721 if metadata.file_type == FileType::Dir { 722 proc.basic_mut().set_cwd(new_path); 723 return Ok(0); 724 } else { 725 return Err(SystemError::ENOTDIR); 726 } 727 } 728 729 /// @brief 获取当前进程的工作目录路径 730 /// 731 /// @param buf 指向缓冲区的指针 732 /// @param size 缓冲区的大小 733 /// 734 /// @return 成功，返回的指针指向包含工作目录路径的字符串 735 /// @return 错误，没有足够的空间 736 pub fn getcwd(buf: &mut [u8]) -> Result<VirtAddr, SystemError> { 737 let proc = ProcessManager::current_pcb(); 738 let cwd = proc.basic().cwd(); 739 740 let cwd_bytes = cwd.as_bytes(); 741 let cwd_len = cwd_bytes.len(); 742 if cwd_len + 1 > buf.len() { 743 return Err(SystemError::ENOMEM); 744 } 745 buf[..cwd_len].copy_from_slice(cwd_bytes); 746 buf[cwd_len] = 0; 747 748 return Ok(VirtAddr::new(buf.as_ptr() as usize)); 749 } 750 751 /// @brief 获取目录中的数据 752 /// 753 /// TODO: 这个函数的语义与Linux不一致，需要修改！！！ 754 /// 755 /// @param fd 文件描述符号 756 /// @param buf 输出缓冲区 757 /// 758 /// @return 成功返回读取的字节数，失败返回错误码 759 pub fn getdents(fd: i32, buf: &mut [u8]) -> Result<usize, SystemError> { 760 let dirent = 761 unsafe { (buf.as_mut_ptr() as *mut Dirent).as_mut() }.ok_or(SystemError::EFAULT)?; 762 763 if fd < 0 || fd as usize > FileDescriptorVec::PROCESS_MAX_FD { 764 return Err(SystemError::EBADF); 765 } 766 767 // 获取fd 768 let binding = ProcessManager::current_pcb().fd_table(); 769 let fd_table_guard = binding.read(); 770 let file = fd_table_guard 771 .get_file_by_fd(fd) 772 .ok_or(SystemError::EBADF)?; 773 774 // drop guard 以避免无法调度的问题 775 drop(fd_table_guard); 776 777 let res = file.readdir(dirent).map(|x| x as usize); 778 779 return res; 780 } 781 782 /// @brief 创建文件夹 783 /// 784 /// @param path(r8) 路径 / mode(r9) 模式 785 /// 786 /// @return uint64_t 负数错误码 / 0表示成功 787 pub fn mkdir(path: *const u8, mode: usize) -> Result<usize, SystemError> { 788 let path = check_and_clone_cstr(path, Some(MAX_PATHLEN))?; 789 do_mkdir_at( 790 AtFlags::AT_FDCWD.bits(), 791 &path, 792 FileMode::from_bits_truncate(mode as u32), 793 )?; 794 return Ok(0); 795 } 796 797 /// **创建硬连接的系统调用** 798 /// 799 /// ## 参数 800 /// 801 /// - 'oldfd': 用于解析源文件路径的文件描述符 802 /// - 'old': 源文件路径 803 /// - 'newfd': 用于解析新文件路径的文件描述符 804 /// - 'new': 新文件将创建的路径 805 /// - 'flags': 标志位，仅以位或方式包含AT_EMPTY_PATH和AT_SYMLINK_FOLLOW 806 /// 807 /// 808 pub fn do_linkat( 809 oldfd: i32, 810 old: &str, 811 newfd: i32, 812 new: &str, 813 flags: AtFlags, 814 ) -> Result<usize, SystemError> { 815 // flag包含其他未规定值时返回EINVAL 816 if !(AtFlags::AT_EMPTY_PATH | AtFlags::AT_SYMLINK_FOLLOW).contains(flags) { 817 return Err(SystemError::EINVAL); 818 } 819 // TODO AT_EMPTY_PATH标志启用时，进行调用者CAP_DAC_READ_SEARCH或相似的检查 820 let symlink_times = if flags.contains(AtFlags::AT_SYMLINK_FOLLOW) { 821 0_usize 822 } else { 823 VFS_MAX_FOLLOW_SYMLINK_TIMES 824 }; 825 let pcb = ProcessManager::current_pcb(); 826 827 // 得到源路径的inode 828 let old_inode: Arc<dyn IndexNode> = if old.is_empty() { 829 if flags.contains(AtFlags::AT_EMPTY_PATH) { 830 // 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。 831 let binding = pcb.fd_table(); 832 let fd_table_guard = binding.read(); 833 let file = fd_table_guard 834 .get_file_by_fd(oldfd) 835 .ok_or(SystemError::EBADF)?; 836 let old_inode = file.inode(); 837 old_inode 838 } else { 839 return Err(SystemError::ENONET); 840 } 841 } else { 842 let (old_begin_inode, old_remain_path) = user_path_at(&pcb, oldfd, old)?; 843 old_begin_inode.lookup_follow_symlink(&old_remain_path, symlink_times)? 844 }; 845 846 // old_inode为目录时返回EPERM 847 if old_inode.metadata().unwrap().file_type == FileType::Dir { 848 return Err(SystemError::EPERM); 849 } 850 851 // 得到新创建节点的父节点 852 let (new_begin_inode, new_remain_path) = user_path_at(&pcb, newfd, new)?; 853 let (new_name, new_parent_path) = rsplit_path(&new_remain_path); 854 let new_parent = 855 new_begin_inode.lookup_follow_symlink(new_parent_path.unwrap_or("/"), symlink_times)?; 856 857 // 被调用者利用downcast_ref判断两inode是否为同一文件系统 858 return new_parent.link(new_name, &old_inode).map(|_| 0); 859 } 860 861 pub fn link(old: *const u8, new: *const u8) -> Result<usize, SystemError> { 862 let get_path = |cstr: *const u8| -> Result<String, SystemError> { 863 let res = check_and_clone_cstr(cstr, Some(MAX_PATHLEN))?; 864 if res.len() >= MAX_PATHLEN { 865 return Err(SystemError::ENAMETOOLONG); 866 } 867 if res.is_empty() { 868 return Err(SystemError::ENOENT); 869 } 870 Ok(res) 871 }; 872 let old = get_path(old)?; 873 let new = get_path(new)?; 874 return Self::do_linkat( 875 AtFlags::AT_FDCWD.bits(), 876 &old, 877 AtFlags::AT_FDCWD.bits(), 878 &new, 879 AtFlags::empty(), 880 ); 881 } 882 883 pub fn linkat( 884 oldfd: i32, 885 old: *const u8, 886 newfd: i32, 887 new: *const u8, 888 flags: i32, 889 ) -> Result<usize, SystemError> { 890 let old = check_and_clone_cstr(old, Some(MAX_PATHLEN))?; 891 let new = check_and_clone_cstr(new, Some(MAX_PATHLEN))?; 892 if old.len() >= MAX_PATHLEN || new.len() >= MAX_PATHLEN { 893 return Err(SystemError::ENAMETOOLONG); 894 } 895 // old 根据flags & AtFlags::AT_EMPTY_PATH判空 896 if new.is_empty() { 897 return Err(SystemError::ENOENT); 898 } 899 let flags = AtFlags::from_bits(flags).ok_or(SystemError::EINVAL)?; 900 Self::do_linkat(oldfd, &old, newfd, &new, flags) 901 } 902 903 /// **删除文件夹、取消文件的链接、删除文件的系统调用** 904 /// 905 /// ## 参数 906 /// 907 /// - `dirfd`：文件夹的文件描述符.目前暂未实现 908 /// - `pathname`：文件夹的路径 909 /// - `flags`：标志位 910 /// 911 /// 912 pub fn unlinkat(dirfd: i32, path: *const u8, flags: u32) -> Result<usize, SystemError> { 913 let flags = AtFlags::from_bits(flags as i32).ok_or(SystemError::EINVAL)?; 914 915 let path = check_and_clone_cstr(path, Some(MAX_PATHLEN))?; 916 917 if flags.contains(AtFlags::AT_REMOVEDIR) { 918 // debug!("rmdir"); 919 match do_remove_dir(dirfd, &path) { 920 Err(err) => { 921 return Err(err); 922 } 923 Ok(_) => { 924 return Ok(0); 925 } 926 } 927 } 928 929 match do_unlink_at(dirfd, &path) { 930 Err(err) => { 931 return Err(err); 932 } 933 Ok(_) => { 934 return Ok(0); 935 } 936 } 937 } 938 939 pub fn rmdir(path: *const u8) -> Result<usize, SystemError> { 940 let path = check_and_clone_cstr(path, Some(MAX_PATHLEN))?; 941 return do_remove_dir(AtFlags::AT_FDCWD.bits(), &path).map(|v| v as usize); 942 } 943 944 pub fn unlink(path: *const u8) -> Result<usize, SystemError> { 945 let path = check_and_clone_cstr(path, Some(MAX_PATHLEN))?; 946 return do_unlink_at(AtFlags::AT_FDCWD.bits(), &path).map(|v| v as usize); 947 } 948 949 /// # 修改文件名 950 /// 951 /// 952 /// ## 参数 953 /// 954 /// - oldfd: 源文件夹文件描述符 955 /// - filename_from: 源文件路径 956 /// - newfd: 目标文件夹文件描述符 957 /// - filename_to: 目标文件路径 958 /// - flags: 标志位 959 /// 960 /// 961 /// ## 返回值 962 /// - Ok(返回值类型): 返回值的说明 963 /// - Err(错误值类型): 错误的说明 964 /// 965 pub fn do_renameat2( 966 oldfd: i32, 967 filename_from: *const u8, 968 newfd: i32, 969 filename_to: *const u8, 970 _flags: u32, 971 ) -> Result<usize, SystemError> { 972 let filename_from = check_and_clone_cstr(filename_from, Some(MAX_PATHLEN)).unwrap(); 973 let filename_to = check_and_clone_cstr(filename_to, Some(MAX_PATHLEN)).unwrap(); 974 // 文件名过长 975 if filename_from.len() > MAX_PATHLEN || filename_to.len() > MAX_PATHLEN { 976 return Err(SystemError::ENAMETOOLONG); 977 } 978 979 //获取pcb，文件节点 980 let pcb = ProcessManager::current_pcb(); 981 let (_old_inode_begin, old_remain_path) = user_path_at(&pcb, oldfd, &filename_from)?; 982 let (_new_inode_begin, new_remain_path) = user_path_at(&pcb, newfd, &filename_to)?; 983 //获取父目录 984 let (old_filename, old_parent_path) = rsplit_path(&old_remain_path); 985 let old_parent_inode = ROOT_INODE() 986 .lookup_follow_symlink(old_parent_path.unwrap_or("/"), VFS_MAX_FOLLOW_SYMLINK_TIMES)?; 987 let (new_filename, new_parent_path) = rsplit_path(&new_remain_path); 988 let new_parent_inode = ROOT_INODE() 989 .lookup_follow_symlink(new_parent_path.unwrap_or("/"), VFS_MAX_FOLLOW_SYMLINK_TIMES)?; 990 old_parent_inode.move_to(old_filename, &new_parent_inode, new_filename)?; 991 return Ok(0); 992 } 993 994 /// @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 995 pub fn dup(oldfd: i32) -> Result<usize, SystemError> { 996 let binding = ProcessManager::current_pcb().fd_table(); 997 let mut fd_table_guard = binding.write(); 998 999 let old_file = fd_table_guard 1000 .get_file_by_fd(oldfd) 1001 .ok_or(SystemError::EBADF)?; 1002 1003 let new_file = old_file.try_clone().ok_or(SystemError::EBADF)?; 1004 // dup默认非cloexec 1005 new_file.set_close_on_exec(false); 1006 // 申请文件描述符，并把文件对象存入其中 1007 let res = fd_table_guard.alloc_fd(new_file, None).map(|x| x as usize); 1008 return res; 1009 } 1010 1011 /// 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， 1012 /// 并返回新复制的文件结构体对应的fd. 1013 /// 如果新fd已经打开，则会先关闭新fd. 1014 /// 1015 /// ## 参数 1016 /// 1017 /// - `oldfd`：旧文件描述符 1018 /// - `newfd`：新文件描述符 1019 /// 1020 /// ## 返回值 1021 /// 1022 /// - 成功：新文件描述符 1023 /// - 失败：错误码 1024 pub fn dup2(oldfd: i32, newfd: i32) -> Result<usize, SystemError> { 1025 let binding = ProcessManager::current_pcb().fd_table(); 1026 let mut fd_table_guard = binding.write(); 1027 return Self::do_dup2(oldfd, newfd, &mut fd_table_guard); 1028 } 1029 1030 pub fn dup3(oldfd: i32, newfd: i32, flags: u32) -> Result<usize, SystemError> { 1031 let flags = FileMode::from_bits_truncate(flags); 1032 if (flags.bits() & !FileMode::O_CLOEXEC.bits()) != 0 { 1033 return Err(SystemError::EINVAL); 1034 } 1035 1036 if oldfd == newfd { 1037 return Err(SystemError::EINVAL); 1038 } 1039 1040 let binding = ProcessManager::current_pcb().fd_table(); 1041 let mut fd_table_guard = binding.write(); 1042 return Self::do_dup3(oldfd, newfd, flags, &mut fd_table_guard); 1043 } 1044 1045 fn do_dup2( 1046 oldfd: i32, 1047 newfd: i32, 1048 fd_table_guard: &mut RwLockWriteGuard<'_, FileDescriptorVec>, 1049 ) -> Result<usize, SystemError> { 1050 Self::do_dup3(oldfd, newfd, FileMode::empty(), fd_table_guard) 1051 } 1052 1053 fn do_dup3( 1054 oldfd: i32, 1055 newfd: i32, 1056 flags: FileMode, 1057 fd_table_guard: &mut RwLockWriteGuard<'_, FileDescriptorVec>, 1058 ) -> Result<usize, SystemError> { 1059 // 确认oldfd, newid是否有效 1060 if !(FileDescriptorVec::validate_fd(oldfd) && FileDescriptorVec::validate_fd(newfd)) { 1061 return Err(SystemError::EBADF); 1062 } 1063 1064 if oldfd == newfd { 1065 // 若oldfd与newfd相等 1066 return Ok(newfd as usize); 1067 } 1068 let new_exists = fd_table_guard.get_file_by_fd(newfd).is_some(); 1069 if new_exists { 1070 // close newfd 1071 if fd_table_guard.drop_fd(newfd).is_err() { 1072 // An I/O error occurred while attempting to close fildes2. 1073 return Err(SystemError::EIO); 1074 } 1075 } 1076 1077 let old_file = fd_table_guard 1078 .get_file_by_fd(oldfd) 1079 .ok_or(SystemError::EBADF)?; 1080 let new_file = old_file.try_clone().ok_or(SystemError::EBADF)?; 1081 1082 if flags.contains(FileMode::O_CLOEXEC) { 1083 new_file.set_close_on_exec(true); 1084 } else { 1085 new_file.set_close_on_exec(false); 1086 } 1087 // 申请文件描述符，并把文件对象存入其中 1088 let res = fd_table_guard 1089 .alloc_fd(new_file, Some(newfd)) 1090 .map(|x| x as usize); 1091 return res; 1092 } 1093 1094 /// # fcntl 1095 /// 1096 /// ## 参数 1097 /// 1098 /// - `fd`：文件描述符 1099 /// - `cmd`：命令 1100 /// - `arg`：参数 1101 pub fn fcntl(fd: i32, cmd: FcntlCommand, arg: i32) -> Result<usize, SystemError> { 1102 // debug!("fcntl ({cmd:?}) fd: {fd}, arg={arg}"); 1103 match cmd { 1104 FcntlCommand::DupFd | FcntlCommand::DupFdCloexec => { 1105 if arg < 0 || arg as usize >= FileDescriptorVec::PROCESS_MAX_FD { 1106 return Err(SystemError::EBADF); 1107 } 1108 let arg = arg as usize; 1109 for i in arg..FileDescriptorVec::PROCESS_MAX_FD { 1110 let binding = ProcessManager::current_pcb().fd_table(); 1111 let mut fd_table_guard = binding.write(); 1112 if fd_table_guard.get_file_by_fd(i as i32).is_none() { 1113 if cmd == FcntlCommand::DupFd { 1114 return Self::do_dup2(fd, i as i32, &mut fd_table_guard); 1115 } else { 1116 return Self::do_dup3( 1117 fd, 1118 i as i32, 1119 FileMode::O_CLOEXEC, 1120 &mut fd_table_guard, 1121 ); 1122 } 1123 } 1124 } 1125 return Err(SystemError::EMFILE); 1126 } 1127 FcntlCommand::GetFd => { 1128 // Get file descriptor flags. 1129 let binding = ProcessManager::current_pcb().fd_table(); 1130 let fd_table_guard = binding.read(); 1131 1132 if let Some(file) = fd_table_guard.get_file_by_fd(fd) { 1133 // drop guard 以避免无法调度的问题 1134 drop(fd_table_guard); 1135 1136 if file.close_on_exec() { 1137 return Ok(FD_CLOEXEC as usize); 1138 } else { 1139 return Ok(0); 1140 } 1141 } 1142 return Err(SystemError::EBADF); 1143 } 1144 FcntlCommand::SetFd => { 1145 // Set file descriptor flags. 1146 let binding = ProcessManager::current_pcb().fd_table(); 1147 let fd_table_guard = binding.write(); 1148 1149 if let Some(file) = fd_table_guard.get_file_by_fd(fd) { 1150 // drop guard 以避免无法调度的问题 1151 drop(fd_table_guard); 1152 let arg = arg as u32; 1153 if arg & FD_CLOEXEC != 0 { 1154 file.set_close_on_exec(true); 1155 } else { 1156 file.set_close_on_exec(false); 1157 } 1158 return Ok(0); 1159 } 1160 return Err(SystemError::EBADF); 1161 } 1162 1163 FcntlCommand::GetFlags => { 1164 // Get file status flags. 1165 let binding = ProcessManager::current_pcb().fd_table(); 1166 let fd_table_guard = binding.read(); 1167 1168 if let Some(file) = fd_table_guard.get_file_by_fd(fd) { 1169 // drop guard 以避免无法调度的问题 1170 drop(fd_table_guard); 1171 return Ok(file.mode().bits() as usize); 1172 } 1173 1174 return Err(SystemError::EBADF); 1175 } 1176 FcntlCommand::SetFlags => { 1177 // Set file status flags. 1178 let binding = ProcessManager::current_pcb().fd_table(); 1179 let fd_table_guard = binding.write(); 1180 1181 if let Some(file) = fd_table_guard.get_file_by_fd(fd) { 1182 let arg = arg as u32; 1183 let mode = FileMode::from_bits(arg).ok_or(SystemError::EINVAL)?; 1184 // drop guard 以避免无法调度的问题 1185 drop(fd_table_guard); 1186 file.set_mode(mode)?; 1187 return Ok(0); 1188 } 1189 1190 return Err(SystemError::EBADF); 1191 } 1192 _ => { 1193 // TODO: unimplemented 1194 // 未实现的命令，返回0，不报错。 1195 1196 warn!("fcntl: unimplemented command: {:?}, defaults to 0.", cmd); 1197 return Err(SystemError::ENOSYS); 1198 } 1199 } 1200 } 1201 1202 /// # ftruncate 1203 /// 1204 /// ## 描述 1205 /// 1206 /// 改变文件大小. 1207 /// 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. 1208 /// 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. 1209 /// 1210 /// ## 参数 1211 /// 1212 /// - `fd`：文件描述符 1213 /// - `len`：文件大小 1214 /// 1215 /// ## 返回值 1216 /// 1217 /// 如果成功，返回0，否则返回错误码. 1218 pub fn ftruncate(fd: i32, len: usize) -> Result<usize, SystemError> { 1219 let binding = ProcessManager::current_pcb().fd_table(); 1220 let fd_table_guard = binding.read(); 1221 1222 if let Some(file) = fd_table_guard.get_file_by_fd(fd) { 1223 // drop guard 以避免无法调度的问题 1224 drop(fd_table_guard); 1225 let r = file.ftruncate(len).map(|_| 0); 1226 return r; 1227 } 1228 1229 return Err(SystemError::EBADF); 1230 } 1231 1232 fn do_fstat(fd: i32) -> Result<PosixKstat, SystemError> { 1233 let binding = ProcessManager::current_pcb().fd_table(); 1234 let fd_table_guard = binding.read(); 1235 let file = fd_table_guard 1236 .get_file_by_fd(fd) 1237 .ok_or(SystemError::EBADF)?; 1238 // drop guard 以避免无法调度的问题 1239 drop(fd_table_guard); 1240 1241 let mut kstat = PosixKstat::new(); 1242 // 获取文件信息 1243 let metadata = file.metadata()?; 1244 kstat.size = metadata.size; 1245 kstat.dev_id = metadata.dev_id as u64; 1246 kstat.inode = metadata.inode_id.into() as u64; 1247 kstat.blcok_size = metadata.blk_size as i64; 1248 kstat.blocks = metadata.blocks as u64; 1249 1250 kstat.atime.tv_sec = metadata.atime.tv_sec; 1251 kstat.atime.tv_nsec = metadata.atime.tv_nsec; 1252 kstat.mtime.tv_sec = metadata.mtime.tv_sec; 1253 kstat.mtime.tv_nsec = metadata.mtime.tv_nsec; 1254 kstat.ctime.tv_sec = metadata.ctime.tv_sec; 1255 kstat.ctime.tv_nsec = metadata.ctime.tv_nsec; 1256 1257 kstat.nlink = metadata.nlinks as u64; 1258 kstat.uid = metadata.uid as i32; 1259 kstat.gid = metadata.gid as i32; 1260 kstat.rdev = metadata.raw_dev.data() as i64; 1261 kstat.mode = metadata.mode; 1262 match file.file_type() { 1263 FileType::File => kstat.mode.insert(ModeType::S_IFREG), 1264 FileType::Dir => kstat.mode.insert(ModeType::S_IFDIR), 1265 FileType::BlockDevice => kstat.mode.insert(ModeType::S_IFBLK), 1266 FileType::CharDevice => kstat.mode.insert(ModeType::S_IFCHR), 1267 FileType::SymLink => kstat.mode.insert(ModeType::S_IFLNK), 1268 FileType::Socket => kstat.mode.insert(ModeType::S_IFSOCK), 1269 FileType::Pipe => kstat.mode.insert(ModeType::S_IFIFO), 1270 FileType::KvmDevice => kstat.mode.insert(ModeType::S_IFCHR), 1271 FileType::FramebufferDevice => kstat.mode.insert(ModeType::S_IFCHR), 1272 } 1273 1274 return Ok(kstat); 1275 } 1276 1277 pub fn fstat(fd: i32, usr_kstat: *mut PosixKstat) -> Result<usize, SystemError> { 1278 let mut writer = UserBufferWriter::new(usr_kstat, size_of::<PosixKstat>(), true)?; 1279 let kstat = Self::do_fstat(fd)?; 1280 1281 writer.copy_one_to_user(&kstat, 0)?; 1282 return Ok(0); 1283 } 1284 1285 pub fn stat(path: *const u8, user_kstat: *mut PosixKstat) -> Result<usize, SystemError> { 1286 let fd = Self::open( 1287 path, 1288 FileMode::O_RDONLY.bits(), 1289 ModeType::empty().bits(), 1290 true, 1291 )?; 1292 let r = Self::fstat(fd as i32, user_kstat); 1293 Self::close(fd).ok(); 1294 return r; 1295 } 1296 1297 pub fn lstat(path: *const u8, user_kstat: *mut PosixKstat) -> Result<usize, SystemError> { 1298 let fd = Self::open( 1299 path, 1300 FileMode::O_RDONLY.bits(), 1301 ModeType::empty().bits(), 1302 false, 1303 )?; 1304 let r = Self::fstat(fd as i32, user_kstat); 1305 Self::close(fd).ok(); 1306 return r; 1307 } 1308 1309 pub fn statfs(path: *const u8, user_statfs: *mut PosixStatfs) -> Result<usize, SystemError> { 1310 let mut writer = UserBufferWriter::new(user_statfs, size_of::<PosixStatfs>(), true)?; 1311 let fd = Self::open( 1312 path, 1313 FileMode::O_RDONLY.bits(), 1314 ModeType::empty().bits(), 1315 true, 1316 )?; 1317 let path = check_and_clone_cstr(path, Some(MAX_PATHLEN)).unwrap(); 1318 let pcb = ProcessManager::current_pcb(); 1319 let (_inode_begin, remain_path) = user_path_at(&pcb, fd as i32, &path)?; 1320 let inode = ROOT_INODE().lookup_follow_symlink(&remain_path, MAX_PATHLEN)?; 1321 let statfs = PosixStatfs::from(inode.fs().super_block()); 1322 writer.copy_one_to_user(&statfs, 0)?; 1323 return Ok(0); 1324 } 1325 1326 pub fn fstatfs(fd: i32, user_statfs: *mut PosixStatfs) -> Result<usize, SystemError> { 1327 let mut writer = UserBufferWriter::new(user_statfs, size_of::<PosixStatfs>(), true)?; 1328 let binding = ProcessManager::current_pcb().fd_table(); 1329 let fd_table_guard = binding.read(); 1330 let file = fd_table_guard 1331 .get_file_by_fd(fd) 1332 .ok_or(SystemError::EBADF)?; 1333 drop(fd_table_guard); 1334 let statfs = PosixStatfs::from(file.inode().fs().super_block()); 1335 writer.copy_one_to_user(&statfs, 0)?; 1336 return Ok(0); 1337 } 1338 1339 pub fn do_statx( 1340 fd: i32, 1341 path: *const u8, 1342 flags: u32, 1343 mask: u32, 1344 usr_kstat: *mut PosixStatx, 1345 ) -> Result<usize, SystemError> { 1346 if usr_kstat.is_null() { 1347 return Err(SystemError::EFAULT); 1348 } 1349 1350 let mask = PosixStatxMask::from_bits_truncate(mask); 1351 1352 if mask.contains(PosixStatxMask::STATX_RESERVED) { 1353 return Err(SystemError::ENAVAIL); 1354 } 1355 1356 let flags = FileMode::from_bits_truncate(flags); 1357 let ofd = Self::open(path, flags.bits(), ModeType::empty().bits, true)?; 1358 1359 let binding = ProcessManager::current_pcb().fd_table(); 1360 let fd_table_guard = binding.read(); 1361 let file = fd_table_guard 1362 .get_file_by_fd(ofd as i32) 1363 .ok_or(SystemError::EBADF)?; 1364 // drop guard 以避免无法调度的问题 1365 drop(fd_table_guard); 1366 let mut writer = UserBufferWriter::new(usr_kstat, size_of::<PosixStatx>(), true)?; 1367 let mut tmp: PosixStatx = PosixStatx::new(); 1368 // 获取文件信息 1369 let metadata = file.metadata()?; 1370 1371 tmp.stx_mask |= PosixStatxMask::STATX_BASIC_STATS; 1372 tmp.stx_blksize = metadata.blk_size as u32; 1373 if mask.contains(PosixStatxMask::STATX_MODE) || mask.contains(PosixStatxMask::STATX_TYPE) { 1374 tmp.stx_mode = metadata.mode; 1375 } 1376 if mask.contains(PosixStatxMask::STATX_NLINK) { 1377 tmp.stx_nlink = metadata.nlinks as u32; 1378 } 1379 if mask.contains(PosixStatxMask::STATX_UID) { 1380 tmp.stx_uid = metadata.uid as u32; 1381 } 1382 if mask.contains(PosixStatxMask::STATX_GID) { 1383 tmp.stx_gid = metadata.gid as u32; 1384 } 1385 if mask.contains(PosixStatxMask::STATX_ATIME) { 1386 tmp.stx_atime.tv_sec = metadata.atime.tv_sec; 1387 tmp.stx_atime.tv_nsec = metadata.atime.tv_nsec; 1388 } 1389 if mask.contains(PosixStatxMask::STATX_MTIME) { 1390 tmp.stx_mtime.tv_sec = metadata.ctime.tv_sec; 1391 tmp.stx_mtime.tv_nsec = metadata.ctime.tv_nsec; 1392 } 1393 if mask.contains(PosixStatxMask::STATX_CTIME) { 1394 // ctime是文件上次修改状态的时间 1395 tmp.stx_ctime.tv_sec = metadata.mtime.tv_sec; 1396 tmp.stx_ctime.tv_nsec = metadata.mtime.tv_nsec; 1397 } 1398 if mask.contains(PosixStatxMask::STATX_INO) { 1399 tmp.stx_inode = metadata.inode_id.into() as u64; 1400 } 1401 if mask.contains(PosixStatxMask::STATX_SIZE) { 1402 tmp.stx_size = metadata.size; 1403 } 1404 if mask.contains(PosixStatxMask::STATX_BLOCKS) { 1405 tmp.stx_blocks = metadata.blocks as u64; 1406 } 1407 1408 if mask.contains(PosixStatxMask::STATX_BTIME) { 1409 // btime是文件创建时间 1410 tmp.stx_btime.tv_sec = metadata.ctime.tv_sec; 1411 tmp.stx_btime.tv_nsec = metadata.ctime.tv_nsec; 1412 } 1413 if mask.contains(PosixStatxMask::STATX_ALL) { 1414 tmp.stx_attributes = StxAttributes::STATX_ATTR_APPEND; 1415 tmp.stx_attributes_mask |= 1416 StxAttributes::STATX_ATTR_AUTOMOUNT | StxAttributes::STATX_ATTR_DAX; 1417 tmp.stx_dev_major = metadata.dev_id as u32; 1418 tmp.stx_dev_minor = metadata.dev_id as u32; // 1419 tmp.stx_rdev_major = metadata.raw_dev.data(); 1420 tmp.stx_rdev_minor = metadata.raw_dev.data(); 1421 } 1422 if mask.contains(PosixStatxMask::STATX_MNT_ID) { 1423 tmp.stx_mnt_id = 0; 1424 } 1425 if mask.contains(PosixStatxMask::STATX_DIOALIGN) { 1426 tmp.stx_dio_mem_align = 0; 1427 tmp.stx_dio_offset_align = 0; 1428 } 1429 1430 match file.file_type() { 1431 FileType::File => tmp.stx_mode.insert(ModeType::S_IFREG), 1432 FileType::Dir => tmp.stx_mode.insert(ModeType::S_IFDIR), 1433 FileType::BlockDevice => tmp.stx_mode.insert(ModeType::S_IFBLK), 1434 FileType::CharDevice => tmp.stx_mode.insert(ModeType::S_IFCHR), 1435 FileType::SymLink => tmp.stx_mode.insert(ModeType::S_IFLNK), 1436 FileType::Socket => tmp.stx_mode.insert(ModeType::S_IFSOCK), 1437 FileType::Pipe => tmp.stx_mode.insert(ModeType::S_IFIFO), 1438 FileType::KvmDevice => tmp.stx_mode.insert(ModeType::S_IFCHR), 1439 FileType::FramebufferDevice => tmp.stx_mode.insert(ModeType::S_IFCHR), 1440 } 1441 1442 writer.copy_one_to_user(&tmp, 0)?; 1443 Self::close(fd as usize).ok(); 1444 return Ok(0); 1445 } 1446 1447 pub fn mknod( 1448 path: *const u8, 1449 mode: ModeType, 1450 dev_t: DeviceNumber, 1451 ) -> Result<usize, SystemError> { 1452 let path = check_and_clone_cstr(path, Some(MAX_PATHLEN))?; 1453 let path = path.as_str().trim(); 1454 1455 let inode: Result<Arc<dyn IndexNode>, SystemError> = 1456 ROOT_INODE().lookup_follow_symlink(path, VFS_MAX_FOLLOW_SYMLINK_TIMES); 1457 1458 if inode.is_ok() { 1459 return Err(SystemError::EEXIST); 1460 } 1461 1462 let (filename, parent_path) = rsplit_path(path); 1463 1464 // 查找父目录 1465 let parent_inode: Arc<dyn IndexNode> = ROOT_INODE() 1466 .lookup_follow_symlink(parent_path.unwrap_or("/"), VFS_MAX_FOLLOW_SYMLINK_TIMES)?; 1467 // 创建nod 1468 parent_inode.mknod(filename, mode, dev_t)?; 1469 1470 return Ok(0); 1471 } 1472 1473 pub fn writev(fd: i32, iov: usize, count: usize) -> Result<usize, SystemError> { 1474 // IoVecs会进行用户态检验 1475 let iovecs = unsafe { IoVecs::from_user(iov as *const IoVec, count, false) }?; 1476 1477 let data = iovecs.gather(); 1478 1479 Self::write(fd, &data) 1480 } 1481 1482 pub fn readv(fd: i32, iov: usize, count: usize) -> Result<usize, SystemError> { 1483 // IoVecs会进行用户态检验 1484 let mut iovecs = unsafe { IoVecs::from_user(iov as *const IoVec, count, true) }?; 1485 1486 let mut data = vec![0; iovecs.0.iter().map(|x| x.len()).sum()]; 1487 1488 let len = Self::read(fd, &mut data)?; 1489 1490 iovecs.scatter(&data[..len]); 1491 1492 return Ok(len); 1493 } 1494 1495 pub fn readlink_at( 1496 dirfd: i32, 1497 path: *const u8, 1498 user_buf: *mut u8, 1499 buf_size: usize, 1500 ) -> Result<usize, SystemError> { 1501 let path = check_and_clone_cstr(path, Some(MAX_PATHLEN))?; 1502 let path = path.as_str().trim(); 1503 let mut user_buf = UserBufferWriter::new(user_buf, buf_size, true)?; 1504 1505 let (inode, path) = user_path_at(&ProcessManager::current_pcb(), dirfd, path)?; 1506 1507 let inode = inode.lookup(path.as_str())?; 1508 if inode.metadata()?.file_type != FileType::SymLink { 1509 return Err(SystemError::EINVAL); 1510 } 1511 1512 let ubuf = user_buf.buffer::<u8>(0).unwrap(); 1513 1514 let file = File::new(inode, FileMode::O_RDONLY)?; 1515 1516 let len = file.read(buf_size, ubuf)?; 1517 1518 return Ok(len); 1519 } 1520 1521 pub fn readlink( 1522 path: *const u8, 1523 user_buf: *mut u8, 1524 buf_size: usize, 1525 ) -> Result<usize, SystemError> { 1526 return Self::readlink_at(AtFlags::AT_FDCWD.bits(), path, user_buf, buf_size); 1527 } 1528 1529 pub fn access(pathname: *const u8, mode: u32) -> Result<usize, SystemError> { 1530 return do_faccessat( 1531 AtFlags::AT_FDCWD.bits(), 1532 pathname, 1533 ModeType::from_bits(mode).ok_or(SystemError::EINVAL)?, 1534 0, 1535 ); 1536 } 1537 1538 pub fn faccessat2( 1539 dirfd: i32, 1540 pathname: *const u8, 1541 mode: u32, 1542 flags: u32, 1543 ) -> Result<usize, SystemError> { 1544 return do_faccessat( 1545 dirfd, 1546 pathname, 1547 ModeType::from_bits(mode).ok_or(SystemError::EINVAL)?, 1548 flags, 1549 ); 1550 } 1551 1552 pub fn chmod(pathname: *const u8, mode: u32) -> Result<usize, SystemError> { 1553 return do_fchmodat( 1554 AtFlags::AT_FDCWD.bits(), 1555 pathname, 1556 ModeType::from_bits(mode).ok_or(SystemError::EINVAL)?, 1557 ); 1558 } 1559 1560 pub fn fchmodat(dirfd: i32, pathname: *const u8, mode: u32) -> Result<usize, SystemError> { 1561 return do_fchmodat( 1562 dirfd, 1563 pathname, 1564 ModeType::from_bits(mode).ok_or(SystemError::EINVAL)?, 1565 ); 1566 } 1567 1568 pub fn fchmod(fd: i32, mode: u32) -> Result<usize, SystemError> { 1569 let _mode = ModeType::from_bits(mode).ok_or(SystemError::EINVAL)?; 1570 let binding = ProcessManager::current_pcb().fd_table(); 1571 let fd_table_guard = binding.read(); 1572 let _file = fd_table_guard 1573 .get_file_by_fd(fd) 1574 .ok_or(SystemError::EBADF)?; 1575 1576 // fchmod没完全实现，因此不修改文件的权限 1577 // todo: 实现fchmod 1578 warn!("fchmod not fully implemented"); 1579 return Ok(0); 1580 } 1581 /// #挂载文件系统 1582 /// 1583 /// 用于挂载文件系统,目前仅支持ramfs挂载 1584 /// 1585 /// ## 参数: 1586 /// 1587 /// - source 挂载设备(暂时不支持) 1588 /// - target 挂载目录 1589 /// - filesystemtype 文件系统 1590 /// - mountflags 挂载选项（暂未实现） 1591 /// - data 带数据挂载 1592 /// 1593 /// ## 返回值 1594 /// - Ok(0): 挂载成功 1595 /// - Err(SystemError) :挂载过程中出错 1596 pub fn mount( 1597 _source: *const u8, 1598 target: *const u8, 1599 filesystemtype: *const u8, 1600 _mountflags: usize, 1601 _data: *const c_void, 1602 ) -> Result<usize, SystemError> { 1603 let target = user_access::check_and_clone_cstr(target, Some(MAX_PATHLEN))?; 1604 1605 let filesystemtype = user_access::check_and_clone_cstr(filesystemtype, Some(MAX_PATHLEN))?; 1606 1607 let filesystemtype = producefs!(FSMAKER, filesystemtype)?; 1608 1609 Vcore::do_mount(filesystemtype, target.to_string().as_str())?; 1610 1611 return Ok(0); 1612 } 1613 1614 // 想法：可以在VFS中实现一个文件系统分发器，流程如下： 1615 // 1. 接受从上方传来的文件类型字符串 1616 // 2. 将传入值与启动时准备好的字符串数组逐个比较（probe） 1617 // 3. 直接在函数内调用构造方法并直接返回文件系统对象 1618 1619 /// src/linux/mount.c `umount` & `umount2` 1620 /// 1621 /// [umount(2) — Linux manual page](https://www.man7.org/linux/man-pages/man2/umount.2.html) 1622 pub fn umount2(target: *const u8, flags: i32) -> Result<(), SystemError> { 1623 let target = user_access::check_and_clone_cstr(target, Some(MAX_PATHLEN))?; 1624 Vcore::do_umount2( 1625 AtFlags::AT_FDCWD.bits(), 1626 &target, 1627 UmountFlag::from_bits(flags).ok_or(SystemError::EINVAL)?, 1628 )?; 1629 return Ok(()); 1630 } 1631 1632 pub fn sys_utimensat( 1633 dirfd: i32, 1634 pathname: *const u8, 1635 times: *const PosixTimeSpec, 1636 flags: u32, 1637 ) -> Result<usize, SystemError> { 1638 let pathname = if pathname.is_null() { 1639 None 1640 } else { 1641 let pathname = check_and_clone_cstr(pathname, Some(MAX_PATHLEN))?; 1642 Some(pathname) 1643 }; 1644 let flags = UtimensFlags::from_bits(flags).ok_or(SystemError::EINVAL)?; 1645 let times = if times.is_null() { 1646 None 1647 } else { 1648 let times_reader = UserBufferReader::new(times, size_of::<PosixTimeSpec>() * 2, true)?; 1649 let times = times_reader.read_from_user::<PosixTimeSpec>(0)?; 1650 Some([times[0], times[1]]) 1651 }; 1652 do_utimensat(dirfd, pathname, times, flags) 1653 } 1654 1655 pub fn sys_utimes( 1656 pathname: *const u8, 1657 times: *const PosixTimeval, 1658 ) -> Result<usize, SystemError> { 1659 let pathname = check_and_clone_cstr(pathname, Some(MAX_PATHLEN))?; 1660 let times = if times.is_null() { 1661 None 1662 } else { 1663 let times_reader = UserBufferReader::new(times, size_of::<PosixTimeval>() * 2, true)?; 1664 let times = times_reader.read_from_user::<PosixTimeval>(0)?; 1665 Some([times[0], times[1]]) 1666 }; 1667 do_utimes(&pathname, times) 1668 } 1669 } 1670 1671 #[repr(C)] 1672 #[derive(Debug, Clone, Copy)] 1673 pub struct IoVec { 1674 /// 缓冲区的起始地址 1675 pub iov_base: *mut u8, 1676 /// 缓冲区的长度 1677 pub iov_len: usize, 1678 } 1679 1680 /// 用于存储多个来自用户空间的IoVec 1681 /// 1682 /// 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。 1683 /// TODO：支持分散读写 1684 #[derive(Debug)] 1685 pub struct IoVecs(Vec<&'static mut [u8]>); 1686 1687 impl IoVecs { 1688 /// 从用户空间的IoVec中构造IoVecs 1689 /// 1690 /// @param iov 用户空间的IoVec 1691 /// @param iovcnt 用户空间的IoVec的数量 1692 /// @param readv 是否为readv系统调用 1693 /// 1694 /// @return 构造成功返回IoVecs，否则返回错误码 1695 pub unsafe fn from_user( 1696 iov: *const IoVec, 1697 iovcnt: usize, 1698 _readv: bool, 1699 ) -> Result<Self, SystemError> { 1700 // 检查iov指针所在空间是否合法 1701 verify_area( 1702 VirtAddr::new(iov as usize), 1703 iovcnt * core::mem::size_of::<IoVec>(), 1704 ) 1705 .map_err(|_| SystemError::EFAULT)?; 1706 1707 // 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） 1708 let iovs: &[IoVec] = core::slice::from_raw_parts(iov, iovcnt); 1709 1710 let mut slices: Vec<&mut [u8]> = vec![]; 1711 slices.reserve(iovs.len()); 1712 1713 for iov in iovs.iter() { 1714 if iov.iov_len == 0 { 1715 continue; 1716 } 1717 1718 verify_area( 1719 VirtAddr::new(iov.iov_base as usize), 1720 iovcnt * core::mem::size_of::<IoVec>(), 1721 ) 1722 .map_err(|_| SystemError::EFAULT)?; 1723 1724 slices.push(core::slice::from_raw_parts_mut(iov.iov_base, iov.iov_len)); 1725 } 1726 1727 return Ok(Self(slices)); 1728 } 1729 1730 /// @brief 将IoVecs中的数据聚合到一个缓冲区中 1731 /// 1732 /// @return 返回聚合后的缓冲区 1733 pub fn gather(&self) -> Vec<u8> { 1734 let mut buf = Vec::new(); 1735 for slice in self.0.iter() { 1736 buf.extend_from_slice(slice); 1737 } 1738 return buf; 1739 } 1740 1741 /// @brief 将给定的数据分散写入到IoVecs中 1742 pub fn scatter(&mut self, data: &[u8]) { 1743 let mut data: &[u8] = data; 1744 for slice in self.0.iter_mut() { 1745 let len = core::cmp::min(slice.len(), data.len()); 1746 if len == 0 { 1747 continue; 1748 } 1749 1750 slice[..len].copy_from_slice(&data[..len]); 1751 data = &data[len..]; 1752 } 1753 } 1754 1755 /// @brief 创建与IoVecs等长的缓冲区 1756 /// 1757 /// @param set_len 是否设置返回的Vec的len。 1758 /// 如果为true，则返回的Vec的len为所有IoVec的长度之和; 1759 /// 否则返回的Vec的len为0，capacity为所有IoVec的长度之和. 1760 /// 1761 /// @return 返回创建的缓冲区 1762 pub fn new_buf(&self, set_len: bool) -> Vec<u8> { 1763 let total_len: usize = self.0.iter().map(|slice| slice.len()).sum(); 1764 let mut buf: Vec<u8> = Vec::with_capacity(total_len); 1765 1766 if set_len { 1767 buf.resize(total_len, 0); 1768 } 1769 return buf; 1770 } 1771 } 1772