1 use core::ffi::c_void; 2 use core::mem::size_of; 3 4 use alloc::{string::String, sync::Arc, vec::Vec}; 5 use log::warn; 6 use system_error::SystemError; 7 8 use crate::producefs; 9 use crate::syscall::user_access::UserBufferReader; 10 use crate::{ 11 driver::base::{block::SeekFrom, device::device_number::DeviceNumber}, 12 filesystem::vfs::{core as Vcore, file::FileDescriptorVec}, 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::{syscall::PosixTimeval, PosixTimeSpec}, 21 }; 22 23 use super::{ 24 core::{do_mkdir_at, do_remove_dir, do_unlink_at}, 25 fcntl::{AtFlags, FcntlCommand, FD_CLOEXEC}, 26 file::{File, FileMode}, 27 open::{do_faccessat, do_fchmodat, do_sys_open, do_utimensat, do_utimes}, 28 utils::{rsplit_path, user_path_at}, 29 Dirent, FileType, IndexNode, SuperBlock, FSMAKER, MAX_PATHLEN, ROOT_INODE, 30 VFS_MAX_FOLLOW_SYMLINK_TIMES, 31 }; 32 33 pub const SEEK_SET: u32 = 0; 34 pub const SEEK_CUR: u32 = 1; 35 pub const SEEK_END: u32 = 2; 36 pub const SEEK_MAX: u32 = 3; 37 38 bitflags! { 39 /// 文件类型和权限 40 #[repr(C)] 41 pub struct ModeType: u32 { 42 /// 掩码 43 const S_IFMT = 0o0_170_000; 44 /// 文件类型 45 const S_IFSOCK = 0o140000; 46 const S_IFLNK = 0o120000; 47 const S_IFREG = 0o100000; 48 const S_IFBLK = 0o060000; 49 const S_IFDIR = 0o040000; 50 const S_IFCHR = 0o020000; 51 const S_IFIFO = 0o010000; 52 53 const S_ISUID = 0o004000; 54 const S_ISGID = 0o002000; 55 const S_ISVTX = 0o001000; 56 /// 文件用户权限 57 const S_IRWXU = 0o0700; 58 const S_IRUSR = 0o0400; 59 const S_IWUSR = 0o0200; 60 const S_IXUSR = 0o0100; 61 /// 文件组权限 62 const S_IRWXG = 0o0070; 63 const S_IRGRP = 0o0040; 64 const S_IWGRP = 0o0020; 65 const S_IXGRP = 0o0010; 66 /// 文件其他用户权限 67 const S_IRWXO = 0o0007; 68 const S_IROTH = 0o0004; 69 const S_IWOTH = 0o0002; 70 const S_IXOTH = 0o0001; 71 72 /// 0o777 73 const S_IRWXUGO = Self::S_IRWXU.bits | Self::S_IRWXG.bits | Self::S_IRWXO.bits; 74 /// 0o7777 75 const S_IALLUGO = Self::S_ISUID.bits | Self::S_ISGID.bits | Self::S_ISVTX.bits| Self::S_IRWXUGO.bits; 76 /// 0o444 77 const S_IRUGO = Self::S_IRUSR.bits | Self::S_IRGRP.bits | Self::S_IROTH.bits; 78 /// 0o222 79 const S_IWUGO = Self::S_IWUSR.bits | Self::S_IWGRP.bits | Self::S_IWOTH.bits; 80 /// 0o111 81 const S_IXUGO = Self::S_IXUSR.bits | Self::S_IXGRP.bits | Self::S_IXOTH.bits; 82 83 84 } 85 } 86 87 #[repr(C)] 88 #[derive(Clone, Copy)] 89 /// # 文件信息结构体 90 pub struct PosixKstat { 91 /// 硬件设备ID 92 dev_id: u64, 93 /// inode号 94 inode: u64, 95 /// 硬链接数 96 nlink: u64, 97 /// 文件权限 98 mode: ModeType, 99 /// 所有者用户ID 100 uid: i32, 101 /// 所有者组ID 102 gid: i32, 103 /// 设备ID 104 rdev: i64, 105 /// 文件大小 106 size: i64, 107 /// 文件系统块大小 108 blcok_size: i64, 109 /// 分配的512B块数 110 blocks: u64, 111 /// 最后访问时间 112 atime: PosixTimeSpec, 113 /// 最后修改时间 114 mtime: PosixTimeSpec, 115 /// 最后状态变化时间 116 ctime: PosixTimeSpec, 117 /// 用于填充结构体大小的空白数据 118 pub _pad: [i8; 24], 119 } 120 impl PosixKstat { 121 fn new() -> Self { 122 Self { 123 inode: 0, 124 dev_id: 0, 125 mode: ModeType { bits: 0 }, 126 nlink: 0, 127 uid: 0, 128 gid: 0, 129 rdev: 0, 130 size: 0, 131 atime: PosixTimeSpec { 132 tv_sec: 0, 133 tv_nsec: 0, 134 }, 135 mtime: PosixTimeSpec { 136 tv_sec: 0, 137 tv_nsec: 0, 138 }, 139 ctime: PosixTimeSpec { 140 tv_sec: 0, 141 tv_nsec: 0, 142 }, 143 blcok_size: 0, 144 blocks: 0, 145 _pad: Default::default(), 146 } 147 } 148 } 149 150 #[repr(C)] 151 #[derive(Clone, Copy)] 152 /// # 文件信息结构体X 153 pub struct PosixStatx { 154 /* 0x00 */ 155 stx_mask: PosixStatxMask, 156 /// 文件系统块大小 157 stx_blksize: u32, 158 /// Flags conveying information about the file [uncond] 159 stx_attributes: StxAttributes, 160 /* 0x10 */ 161 /// 硬链接数 162 stx_nlink: u32, 163 /// 所有者用户ID 164 stx_uid: u32, 165 /// 所有者组ID 166 stx_gid: u32, 167 /// 文件权限 168 stx_mode: ModeType, 169 170 /* 0x20 */ 171 /// inode号 172 stx_inode: u64, 173 /// 文件大小 174 stx_size: i64, 175 /// 分配的512B块数 176 stx_blocks: u64, 177 /// Mask to show what's supported in stx_attributes 178 stx_attributes_mask: StxAttributes, 179 180 /* 0x40 */ 181 /// 最后访问时间 182 stx_atime: PosixTimeSpec, 183 /// 文件创建时间 184 stx_btime: PosixTimeSpec, 185 /// 最后状态变化时间 186 stx_ctime: PosixTimeSpec, 187 /// 最后修改时间 188 stx_mtime: PosixTimeSpec, 189 190 /* 0x80 */ 191 /// 主设备ID 192 stx_rdev_major: u32, 193 /// 次设备ID 194 stx_rdev_minor: u32, 195 /// 主硬件设备ID 196 stx_dev_major: u32, 197 /// 次硬件设备ID 198 stx_dev_minor: u32, 199 200 /* 0x90 */ 201 stx_mnt_id: u64, 202 stx_dio_mem_align: u32, 203 stx_dio_offset_align: u32, 204 } 205 impl PosixStatx { 206 fn new() -> Self { 207 Self { 208 stx_mask: PosixStatxMask::STATX_BASIC_STATS, 209 stx_blksize: 0, 210 stx_attributes: StxAttributes::STATX_ATTR_APPEND, 211 stx_nlink: 0, 212 stx_uid: 0, 213 stx_gid: 0, 214 stx_mode: ModeType { bits: 0 }, 215 stx_inode: 0, 216 stx_size: 0, 217 stx_blocks: 0, 218 stx_attributes_mask: StxAttributes::STATX_ATTR_APPEND, 219 stx_atime: PosixTimeSpec { 220 tv_sec: 0, 221 tv_nsec: 0, 222 }, 223 stx_btime: PosixTimeSpec { 224 tv_sec: 0, 225 tv_nsec: 0, 226 }, 227 stx_ctime: PosixTimeSpec { 228 tv_sec: 0, 229 tv_nsec: 0, 230 }, 231 stx_mtime: PosixTimeSpec { 232 tv_sec: 0, 233 tv_nsec: 0, 234 }, 235 stx_rdev_major: 0, 236 stx_rdev_minor: 0, 237 stx_dev_major: 0, 238 stx_dev_minor: 0, 239 stx_mnt_id: 0, 240 stx_dio_mem_align: 0, 241 stx_dio_offset_align: 0, 242 } 243 } 244 } 245 246 bitflags! { 247 pub struct PosixStatxMask: u32{ 248 /// Want stx_mode & S_IFMT 249 const STATX_TYPE = 0x00000001; 250 251 /// Want stx_mode & ~S_IFMT 252 const STATX_MODE = 0x00000002; 253 254 /// Want stx_nlink 255 const STATX_NLINK = 0x00000004; 256 257 /// Want stx_uid 258 const STATX_UID = 0x00000008; 259 260 /// Want stx_gid 261 const STATX_GID = 0x00000010; 262 263 /// Want stx_atime 264 const STATX_ATIME = 0x00000020; 265 266 /// Want stx_mtime 267 const STATX_MTIME = 0x00000040; 268 269 /// Want stx_ctime 270 const STATX_CTIME = 0x00000080; 271 272 /// Want stx_ino 273 const STATX_INO = 0x00000100; 274 275 /// Want stx_size 276 const STATX_SIZE = 0x00000200; 277 278 /// Want stx_blocks 279 const STATX_BLOCKS = 0x00000400; 280 281 /// [All of the above] 282 const STATX_BASIC_STATS = 0x000007ff; 283 284 /// Want stx_btime 285 const STATX_BTIME = 0x00000800; 286 287 /// The same as STATX_BASIC_STATS | STATX_BTIME. 288 /// It is deprecated and should not be used. 289 const STATX_ALL = 0x00000fff; 290 291 /// Want stx_mnt_id (since Linux 5.8) 292 const STATX_MNT_ID = 0x00001000; 293 294 /// Want stx_dio_mem_align and stx_dio_offset_align 295 /// (since Linux 6.1; support varies by filesystem) 296 const STATX_DIOALIGN = 0x00002000; 297 298 /// Reserved for future struct statx expansion 299 const STATX_RESERVED = 0x80000000; 300 } 301 } 302 303 bitflags! { 304 pub struct StxAttributes: u64 { 305 /// 文件被文件系统压缩 306 const STATX_ATTR_COMPRESSED = 0x00000004; 307 /// 文件被标记为不可修改 308 const STATX_ATTR_IMMUTABLE = 0x00000010; 309 /// 文件是只追加写入的 310 const STATX_ATTR_APPEND = 0x00000020; 311 /// 文件不会被备份 312 const STATX_ATTR_NODUMP = 0x00000040; 313 /// 文件需要密钥才能在文件系统中解密 314 const STATX_ATTR_ENCRYPTED = 0x00000800; 315 /// 目录是自动挂载触发器 316 const STATX_ATTR_AUTOMOUNT = 0x00001000; 317 /// 目录是挂载点的根目录 318 const STATX_ATTR_MOUNT_ROOT = 0x00002000; 319 /// 文件受到 Verity 保护 320 const STATX_ATTR_VERITY = 0x00100000; 321 /// 文件当前处于 DAX 状态 CPU直接访问 322 const STATX_ATTR_DAX = 0x00200000; 323 } 324 } 325 326 bitflags! { 327 pub struct UtimensFlags: u32 { 328 /// 不需要解释符号链接 329 const AT_SYMLINK_NOFOLLOW = 0x100; 330 } 331 } 332 333 #[repr(C)] 334 #[derive(Debug, Clone, Copy)] 335 pub struct PosixStatfs { 336 f_type: u64, 337 f_bsize: u64, 338 f_blocks: u64, 339 f_bfree: u64, 340 f_bavail: u64, 341 f_files: u64, 342 f_ffree: u64, 343 f_fsid: u64, 344 f_namelen: u64, 345 f_frsize: u64, 346 f_flags: u64, 347 f_spare: [u64; 4], 348 } 349 350 impl From<SuperBlock> for PosixStatfs { 351 fn from(super_block: SuperBlock) -> Self { 352 Self { 353 f_type: super_block.magic.bits, 354 f_bsize: super_block.bsize, 355 f_blocks: super_block.blocks, 356 f_bfree: super_block.bfree, 357 f_bavail: super_block.bavail, 358 f_files: super_block.files, 359 f_ffree: super_block.ffree, 360 f_fsid: super_block.fsid, 361 f_namelen: super_block.namelen, 362 f_frsize: super_block.frsize, 363 f_flags: super_block.flags, 364 f_spare: [0u64; 4], 365 } 366 } 367 } 368 /// 369 /// Arguments for how openat2(2) should open the target path. If only @flags and 370 /// @mode are non-zero, then openat2(2) operates very similarly to openat(2). 371 /// 372 /// However, unlike openat(2), unknown or invalid bits in @flags result in 373 /// -EINVAL rather than being silently ignored. @mode must be zero unless one of 374 /// {O_CREAT, O_TMPFILE} are set. 375 /// 376 /// ## 成员变量 377 /// 378 /// - flags: O_* flags. 379 /// - mode: O_CREAT/O_TMPFILE file mode. 380 /// - resolve: RESOLVE_* flags. 381 #[derive(Debug, Clone, Copy)] 382 #[repr(C)] 383 pub struct PosixOpenHow { 384 pub flags: u64, 385 pub mode: u64, 386 pub resolve: u64, 387 } 388 389 impl PosixOpenHow { 390 #[allow(dead_code)] 391 pub fn new(flags: u64, mode: u64, resolve: u64) -> Self { 392 Self { 393 flags, 394 mode, 395 resolve, 396 } 397 } 398 } 399 400 #[allow(dead_code)] 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 .into_string() 488 .map_err(|_| SystemError::EINVAL)?; 489 490 let open_flags: FileMode = FileMode::from_bits(o_flags).ok_or(SystemError::EINVAL)?; 491 let mode = ModeType::from_bits(mode).ok_or(SystemError::EINVAL)?; 492 return do_sys_open( 493 AtFlags::AT_FDCWD.bits(), 494 &path, 495 open_flags, 496 mode, 497 follow_symlink, 498 ); 499 } 500 501 pub fn openat( 502 dirfd: i32, 503 path: *const u8, 504 o_flags: u32, 505 mode: u32, 506 follow_symlink: bool, 507 ) -> Result<usize, SystemError> { 508 let path = check_and_clone_cstr(path, Some(MAX_PATHLEN))? 509 .into_string() 510 .map_err(|_| SystemError::EINVAL)?; 511 512 let open_flags: FileMode = FileMode::from_bits(o_flags).ok_or(SystemError::EINVAL)?; 513 let mode = ModeType::from_bits(mode).ok_or(SystemError::EINVAL)?; 514 return do_sys_open(dirfd, &path, open_flags, mode, follow_symlink); 515 } 516 517 /// @brief 关闭文件 518 /// 519 /// @param fd 文件描述符编号 520 /// 521 /// @return 成功返回0，失败返回错误码 522 pub fn close(fd: usize) -> Result<usize, SystemError> { 523 let binding = ProcessManager::current_pcb().fd_table(); 524 let mut fd_table_guard = binding.write(); 525 let _file = fd_table_guard.drop_fd(fd as i32)?; 526 drop(fd_table_guard); 527 Ok(0) 528 } 529 530 /// @brief 发送命令到文件描述符对应的设备， 531 /// 532 /// @param fd 文件描述符编号 533 /// @param cmd 设备相关的请求类型 534 /// 535 /// @return Ok(usize) 成功返回0 536 /// @return Err(SystemError) 读取失败，返回posix错误码 537 pub fn ioctl(fd: usize, cmd: u32, data: usize) -> Result<usize, SystemError> { 538 let binding = ProcessManager::current_pcb().fd_table(); 539 let fd_table_guard = binding.read(); 540 541 let file = fd_table_guard 542 .get_file_by_fd(fd as i32) 543 .ok_or(SystemError::EBADF)?; 544 545 // drop guard 以避免无法调度的问题 546 drop(fd_table_guard); 547 let r = file.inode().ioctl(cmd, data, &file.private_data.lock()); 548 return r; 549 } 550 551 /// @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。 552 /// 553 /// @param fd 文件描述符编号 554 /// @param buf 输出缓冲区 555 /// 556 /// @return Ok(usize) 成功读取的数据的字节数 557 /// @return Err(SystemError) 读取失败，返回posix错误码 558 pub fn read(fd: i32, buf: &mut [u8]) -> Result<usize, SystemError> { 559 let binding = ProcessManager::current_pcb().fd_table(); 560 let fd_table_guard = binding.read(); 561 562 let file = fd_table_guard.get_file_by_fd(fd); 563 if file.is_none() { 564 return Err(SystemError::EBADF); 565 } 566 // drop guard 以避免无法调度的问题 567 drop(fd_table_guard); 568 let file = file.unwrap(); 569 570 return file.read(buf.len(), buf); 571 } 572 573 /// @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。 574 /// 575 /// @param fd 文件描述符编号 576 /// @param buf 输入缓冲区 577 /// 578 /// @return Ok(usize) 成功写入的数据的字节数 579 /// @return Err(SystemError) 写入失败，返回posix错误码 580 pub fn write(fd: i32, buf: &[u8]) -> Result<usize, SystemError> { 581 let binding = ProcessManager::current_pcb().fd_table(); 582 let fd_table_guard = binding.read(); 583 584 let file = fd_table_guard 585 .get_file_by_fd(fd) 586 .ok_or(SystemError::EBADF)?; 587 588 // drop guard 以避免无法调度的问题 589 drop(fd_table_guard); 590 return file.write(buf.len(), buf); 591 } 592 593 /// @brief 调整文件操作指针的位置 594 /// 595 /// @param fd 文件描述符编号 596 /// @param seek 调整的方式 597 /// 598 /// @return Ok(usize) 调整后，文件访问指针相对于文件头部的偏移量 599 /// @return Err(SystemError) 调整失败，返回posix错误码 600 pub fn lseek(fd: i32, offset: i64, seek: u32) -> Result<usize, SystemError> { 601 let seek = match seek { 602 SEEK_SET => Ok(SeekFrom::SeekSet(offset)), 603 SEEK_CUR => Ok(SeekFrom::SeekCurrent(offset)), 604 SEEK_END => Ok(SeekFrom::SeekEnd(offset)), 605 SEEK_MAX => Ok(SeekFrom::SeekEnd(0)), 606 _ => Err(SystemError::EINVAL), 607 }?; 608 609 let binding = ProcessManager::current_pcb().fd_table(); 610 let fd_table_guard = binding.read(); 611 let file = fd_table_guard 612 .get_file_by_fd(fd) 613 .ok_or(SystemError::EBADF)?; 614 615 // drop guard 以避免无法调度的问题 616 drop(fd_table_guard); 617 return file.lseek(seek); 618 } 619 620 /// # sys_pread64 系统调用的实际执行函数 621 /// 622 /// ## 参数 623 /// - `fd`: 文件描述符 624 /// - `buf`: 读出缓冲区 625 /// - `len`: 要读取的字节数 626 /// - `offset`: 文件偏移量 627 pub fn pread(fd: i32, buf: &mut [u8], len: usize, offset: usize) -> Result<usize, SystemError> { 628 let binding = ProcessManager::current_pcb().fd_table(); 629 let fd_table_guard = binding.read(); 630 631 let file = fd_table_guard.get_file_by_fd(fd); 632 if file.is_none() { 633 return Err(SystemError::EBADF); 634 } 635 // drop guard 以避免无法调度的问题 636 drop(fd_table_guard); 637 let file = file.unwrap(); 638 639 return file.pread(offset, len, buf); 640 } 641 642 /// # sys_pwrite64 系统调用的实际执行函数 643 /// 644 /// ## 参数 645 /// - `fd`: 文件描述符 646 /// - `buf`: 写入缓冲区 647 /// - `len`: 要写入的字节数 648 /// - `offset`: 文件偏移量 649 pub fn pwrite(fd: i32, buf: &[u8], len: usize, offset: usize) -> Result<usize, SystemError> { 650 let binding = ProcessManager::current_pcb().fd_table(); 651 let fd_table_guard = binding.read(); 652 653 let file = fd_table_guard.get_file_by_fd(fd); 654 if file.is_none() { 655 return Err(SystemError::EBADF); 656 } 657 // drop guard 以避免无法调度的问题 658 drop(fd_table_guard); 659 let file = file.unwrap(); 660 661 return file.pwrite(offset, len, buf); 662 } 663 664 /// @brief 切换工作目录 665 /// 666 /// @param dest_path 目标路径 667 /// 668 /// @return 返回码 描述 669 /// 0 | 成功 670 /// 671 /// EACCESS | 权限不足 672 /// 673 /// ELOOP | 解析path时遇到路径循环 674 /// 675 /// ENAMETOOLONG | 路径名过长 676 /// 677 /// ENOENT | 目标文件或目录不存在 678 /// 679 /// ENODIR | 检索期间发现非目录项 680 /// 681 /// ENOMEM | 系统内存不足 682 /// 683 /// EFAULT | 错误的地址 684 /// 685 /// ENAMETOOLONG | 路径过长 686 pub fn chdir(path: *const u8) -> Result<usize, SystemError> { 687 if path.is_null() { 688 return Err(SystemError::EFAULT); 689 } 690 691 let path = check_and_clone_cstr(path, Some(MAX_PATHLEN))? 692 .into_string() 693 .map_err(|_| SystemError::EINVAL)?; 694 695 let proc = ProcessManager::current_pcb(); 696 // Copy path to kernel space to avoid some security issues 697 let mut new_path = String::from(""); 698 if !path.is_empty() { 699 let cwd = match path.as_bytes()[0] { 700 b'/' => String::from("/"), 701 _ => proc.basic().cwd(), 702 }; 703 let mut cwd_vec: Vec<_> = cwd.split('/').filter(|&x| !x.is_empty()).collect(); 704 let path_split = path.split('/').filter(|&x| !x.is_empty()); 705 for seg in path_split { 706 if seg == ".." { 707 cwd_vec.pop(); 708 } else if seg == "." { 709 // 当前目录 710 } else { 711 cwd_vec.push(seg); 712 } 713 } 714 //proc.basic().set_path(String::from("")); 715 for seg in cwd_vec { 716 new_path.push('/'); 717 new_path.push_str(seg); 718 } 719 if new_path.is_empty() { 720 new_path = String::from("/"); 721 } 722 } 723 let inode = 724 match ROOT_INODE().lookup_follow_symlink(&new_path, VFS_MAX_FOLLOW_SYMLINK_TIMES) { 725 Err(_) => { 726 return Err(SystemError::ENOENT); 727 } 728 Ok(i) => i, 729 }; 730 let metadata = inode.metadata()?; 731 if metadata.file_type == FileType::Dir { 732 proc.basic_mut().set_cwd(new_path); 733 return Ok(0); 734 } else { 735 return Err(SystemError::ENOTDIR); 736 } 737 } 738 739 /// @brief 获取当前进程的工作目录路径 740 /// 741 /// @param buf 指向缓冲区的指针 742 /// @param size 缓冲区的大小 743 /// 744 /// @return 成功，返回的指针指向包含工作目录路径的字符串 745 /// @return 错误，没有足够的空间 746 pub fn getcwd(buf: &mut [u8]) -> Result<VirtAddr, SystemError> { 747 let proc = ProcessManager::current_pcb(); 748 let cwd = proc.basic().cwd(); 749 750 let cwd_bytes = cwd.as_bytes(); 751 let cwd_len = cwd_bytes.len(); 752 if cwd_len + 1 > buf.len() { 753 return Err(SystemError::ENOMEM); 754 } 755 buf[..cwd_len].copy_from_slice(cwd_bytes); 756 buf[cwd_len] = 0; 757 758 return Ok(VirtAddr::new(buf.as_ptr() as usize)); 759 } 760 761 /// @brief 获取目录中的数据 762 /// 763 /// TODO: 这个函数的语义与Linux不一致，需要修改！！！ 764 /// 765 /// @param fd 文件描述符号 766 /// @param buf 输出缓冲区 767 /// 768 /// @return 成功返回读取的字节数，失败返回错误码 769 pub fn getdents(fd: i32, buf: &mut [u8]) -> Result<usize, SystemError> { 770 let dirent = 771 unsafe { (buf.as_mut_ptr() as *mut Dirent).as_mut() }.ok_or(SystemError::EFAULT)?; 772 773 if fd < 0 || fd as usize > FileDescriptorVec::PROCESS_MAX_FD { 774 return Err(SystemError::EBADF); 775 } 776 777 // 获取fd 778 let binding = ProcessManager::current_pcb().fd_table(); 779 let fd_table_guard = binding.read(); 780 let file = fd_table_guard 781 .get_file_by_fd(fd) 782 .ok_or(SystemError::EBADF)?; 783 784 // drop guard 以避免无法调度的问题 785 drop(fd_table_guard); 786 787 let res = file.readdir(dirent).map(|x| x as usize); 788 789 return res; 790 } 791 792 /// @brief 创建文件夹 793 /// 794 /// @param path(r8) 路径 / mode(r9) 模式 795 /// 796 /// @return uint64_t 负数错误码 / 0表示成功 797 pub fn mkdir(path: *const u8, mode: usize) -> Result<usize, SystemError> { 798 let path = check_and_clone_cstr(path, Some(MAX_PATHLEN))? 799 .into_string() 800 .map_err(|_| SystemError::EINVAL)?; 801 802 do_mkdir_at( 803 AtFlags::AT_FDCWD.bits(), 804 &path, 805 FileMode::from_bits_truncate(mode as u32), 806 )?; 807 return Ok(0); 808 } 809 810 /// **创建硬连接的系统调用** 811 /// 812 /// ## 参数 813 /// 814 /// - 'oldfd': 用于解析源文件路径的文件描述符 815 /// - 'old': 源文件路径 816 /// - 'newfd': 用于解析新文件路径的文件描述符 817 /// - 'new': 新文件将创建的路径 818 /// - 'flags': 标志位，仅以位或方式包含AT_EMPTY_PATH和AT_SYMLINK_FOLLOW 819 /// 820 /// 821 pub fn do_linkat( 822 oldfd: i32, 823 old: &str, 824 newfd: i32, 825 new: &str, 826 flags: AtFlags, 827 ) -> Result<usize, SystemError> { 828 // flag包含其他未规定值时返回EINVAL 829 if !(AtFlags::AT_EMPTY_PATH | AtFlags::AT_SYMLINK_FOLLOW).contains(flags) { 830 return Err(SystemError::EINVAL); 831 } 832 // TODO AT_EMPTY_PATH标志启用时，进行调用者CAP_DAC_READ_SEARCH或相似的检查 833 let symlink_times = if flags.contains(AtFlags::AT_SYMLINK_FOLLOW) { 834 0_usize 835 } else { 836 VFS_MAX_FOLLOW_SYMLINK_TIMES 837 }; 838 let pcb = ProcessManager::current_pcb(); 839 840 // 得到源路径的inode 841 let old_inode: Arc<dyn IndexNode> = if old.is_empty() { 842 if flags.contains(AtFlags::AT_EMPTY_PATH) { 843 // 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。 844 let binding = pcb.fd_table(); 845 let fd_table_guard = binding.read(); 846 let file = fd_table_guard 847 .get_file_by_fd(oldfd) 848 .ok_or(SystemError::EBADF)?; 849 let old_inode = file.inode(); 850 old_inode 851 } else { 852 return Err(SystemError::ENONET); 853 } 854 } else { 855 let (old_begin_inode, old_remain_path) = user_path_at(&pcb, oldfd, old)?; 856 old_begin_inode.lookup_follow_symlink(&old_remain_path, symlink_times)? 857 }; 858 859 // old_inode为目录时返回EPERM 860 if old_inode.metadata().unwrap().file_type == FileType::Dir { 861 return Err(SystemError::EPERM); 862 } 863 864 // 得到新创建节点的父节点 865 let (new_begin_inode, new_remain_path) = user_path_at(&pcb, newfd, new)?; 866 let (new_name, new_parent_path) = rsplit_path(&new_remain_path); 867 let new_parent = 868 new_begin_inode.lookup_follow_symlink(new_parent_path.unwrap_or("/"), symlink_times)?; 869 870 // 被调用者利用downcast_ref判断两inode是否为同一文件系统 871 return new_parent.link(new_name, &old_inode).map(|_| 0); 872 } 873 874 pub fn link(old: *const u8, new: *const u8) -> Result<usize, SystemError> { 875 let get_path = |cstr: *const u8| -> Result<String, SystemError> { 876 let res = check_and_clone_cstr(cstr, Some(MAX_PATHLEN))? 877 .into_string() 878 .map_err(|_| SystemError::EINVAL)?; 879 880 if res.len() >= MAX_PATHLEN { 881 return Err(SystemError::ENAMETOOLONG); 882 } 883 if res.is_empty() { 884 return Err(SystemError::ENOENT); 885 } 886 Ok(res) 887 }; 888 let old = get_path(old)?; 889 let new = get_path(new)?; 890 return Self::do_linkat( 891 AtFlags::AT_FDCWD.bits(), 892 &old, 893 AtFlags::AT_FDCWD.bits(), 894 &new, 895 AtFlags::empty(), 896 ); 897 } 898 899 pub fn linkat( 900 oldfd: i32, 901 old: *const u8, 902 newfd: i32, 903 new: *const u8, 904 flags: i32, 905 ) -> Result<usize, SystemError> { 906 let old = check_and_clone_cstr(old, Some(MAX_PATHLEN))? 907 .into_string() 908 .map_err(|_| SystemError::EINVAL)?; 909 let new = check_and_clone_cstr(new, Some(MAX_PATHLEN))? 910 .into_string() 911 .map_err(|_| SystemError::EINVAL)?; 912 if old.len() >= MAX_PATHLEN || new.len() >= MAX_PATHLEN { 913 return Err(SystemError::ENAMETOOLONG); 914 } 915 // old 根据flags & AtFlags::AT_EMPTY_PATH判空 916 if new.is_empty() { 917 return Err(SystemError::ENOENT); 918 } 919 let flags = AtFlags::from_bits(flags).ok_or(SystemError::EINVAL)?; 920 Self::do_linkat(oldfd, &old, newfd, &new, flags) 921 } 922 923 /// **删除文件夹、取消文件的链接、删除文件的系统调用** 924 /// 925 /// ## 参数 926 /// 927 /// - `dirfd`：文件夹的文件描述符.目前暂未实现 928 /// - `pathname`：文件夹的路径 929 /// - `flags`：标志位 930 /// 931 /// 932 pub fn unlinkat(dirfd: i32, path: *const u8, flags: u32) -> Result<usize, SystemError> { 933 let flags = AtFlags::from_bits(flags as i32).ok_or(SystemError::EINVAL)?; 934 935 let path = check_and_clone_cstr(path, Some(MAX_PATHLEN))? 936 .into_string() 937 .map_err(|_| SystemError::EINVAL)?; 938 939 if flags.contains(AtFlags::AT_REMOVEDIR) { 940 // debug!("rmdir"); 941 match do_remove_dir(dirfd, &path) { 942 Err(err) => { 943 return Err(err); 944 } 945 Ok(_) => { 946 return Ok(0); 947 } 948 } 949 } 950 951 match do_unlink_at(dirfd, &path) { 952 Err(err) => { 953 return Err(err); 954 } 955 Ok(_) => { 956 return Ok(0); 957 } 958 } 959 } 960 961 pub fn rmdir(path: *const u8) -> Result<usize, SystemError> { 962 let path = check_and_clone_cstr(path, Some(MAX_PATHLEN))? 963 .into_string() 964 .map_err(|_| SystemError::EINVAL)?; 965 return do_remove_dir(AtFlags::AT_FDCWD.bits(), &path).map(|v| v as usize); 966 } 967 968 pub fn unlink(path: *const u8) -> Result<usize, SystemError> { 969 let path = check_and_clone_cstr(path, Some(MAX_PATHLEN))? 970 .into_string() 971 .map_err(|_| SystemError::EINVAL)?; 972 return do_unlink_at(AtFlags::AT_FDCWD.bits(), &path).map(|v| v as usize); 973 } 974 975 /// # 修改文件名 976 /// 977 /// 978 /// ## 参数 979 /// 980 /// - oldfd: 源文件夹文件描述符 981 /// - filename_from: 源文件路径 982 /// - newfd: 目标文件夹文件描述符 983 /// - filename_to: 目标文件路径 984 /// - flags: 标志位 985 /// 986 /// 987 /// ## 返回值 988 /// - Ok(返回值类型): 返回值的说明 989 /// - Err(错误值类型): 错误的说明 990 /// 991 pub fn do_renameat2( 992 oldfd: i32, 993 filename_from: *const u8, 994 newfd: i32, 995 filename_to: *const u8, 996 _flags: u32, 997 ) -> Result<usize, SystemError> { 998 let filename_from = check_and_clone_cstr(filename_from, Some(MAX_PATHLEN)) 999 .unwrap() 1000 .into_string() 1001 .map_err(|_| SystemError::EINVAL)?; 1002 let filename_to = check_and_clone_cstr(filename_to, Some(MAX_PATHLEN)) 1003 .unwrap() 1004 .into_string() 1005 .map_err(|_| SystemError::EINVAL)?; 1006 // 文件名过长 1007 if filename_from.len() > MAX_PATHLEN || filename_to.len() > MAX_PATHLEN { 1008 return Err(SystemError::ENAMETOOLONG); 1009 } 1010 1011 //获取pcb，文件节点 1012 let pcb = ProcessManager::current_pcb(); 1013 let (_old_inode_begin, old_remain_path) = user_path_at(&pcb, oldfd, &filename_from)?; 1014 let (_new_inode_begin, new_remain_path) = user_path_at(&pcb, newfd, &filename_to)?; 1015 //获取父目录 1016 let (old_filename, old_parent_path) = rsplit_path(&old_remain_path); 1017 let old_parent_inode = ROOT_INODE() 1018 .lookup_follow_symlink(old_parent_path.unwrap_or("/"), VFS_MAX_FOLLOW_SYMLINK_TIMES)?; 1019 let (new_filename, new_parent_path) = rsplit_path(&new_remain_path); 1020 let new_parent_inode = ROOT_INODE() 1021 .lookup_follow_symlink(new_parent_path.unwrap_or("/"), VFS_MAX_FOLLOW_SYMLINK_TIMES)?; 1022 old_parent_inode.move_to(old_filename, &new_parent_inode, new_filename)?; 1023 return Ok(0); 1024 } 1025 1026 /// @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 1027 pub fn dup(oldfd: i32) -> Result<usize, SystemError> { 1028 let binding = ProcessManager::current_pcb().fd_table(); 1029 let mut fd_table_guard = binding.write(); 1030 1031 let old_file = fd_table_guard 1032 .get_file_by_fd(oldfd) 1033 .ok_or(SystemError::EBADF)?; 1034 1035 let new_file = old_file.try_clone().ok_or(SystemError::EBADF)?; 1036 // dup默认非cloexec 1037 new_file.set_close_on_exec(false); 1038 // 申请文件描述符，并把文件对象存入其中 1039 let res = fd_table_guard.alloc_fd(new_file, None).map(|x| x as usize); 1040 return res; 1041 } 1042 1043 /// 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， 1044 /// 并返回新复制的文件结构体对应的fd. 1045 /// 如果新fd已经打开，则会先关闭新fd. 1046 /// 1047 /// ## 参数 1048 /// 1049 /// - `oldfd`：旧文件描述符 1050 /// - `newfd`：新文件描述符 1051 /// 1052 /// ## 返回值 1053 /// 1054 /// - 成功：新文件描述符 1055 /// - 失败：错误码 1056 pub fn dup2(oldfd: i32, newfd: i32) -> Result<usize, SystemError> { 1057 let binding = ProcessManager::current_pcb().fd_table(); 1058 let mut fd_table_guard = binding.write(); 1059 return Self::do_dup2(oldfd, newfd, &mut fd_table_guard); 1060 } 1061 1062 pub fn dup3(oldfd: i32, newfd: i32, flags: u32) -> Result<usize, SystemError> { 1063 let flags = FileMode::from_bits_truncate(flags); 1064 if (flags.bits() & !FileMode::O_CLOEXEC.bits()) != 0 { 1065 return Err(SystemError::EINVAL); 1066 } 1067 1068 if oldfd == newfd { 1069 return Err(SystemError::EINVAL); 1070 } 1071 1072 let binding = ProcessManager::current_pcb().fd_table(); 1073 let mut fd_table_guard = binding.write(); 1074 return Self::do_dup3(oldfd, newfd, flags, &mut fd_table_guard); 1075 } 1076 1077 fn do_dup2( 1078 oldfd: i32, 1079 newfd: i32, 1080 fd_table_guard: &mut RwLockWriteGuard<'_, FileDescriptorVec>, 1081 ) -> Result<usize, SystemError> { 1082 Self::do_dup3(oldfd, newfd, FileMode::empty(), fd_table_guard) 1083 } 1084 1085 fn do_dup3( 1086 oldfd: i32, 1087 newfd: i32, 1088 flags: FileMode, 1089 fd_table_guard: &mut RwLockWriteGuard<'_, FileDescriptorVec>, 1090 ) -> Result<usize, SystemError> { 1091 // 确认oldfd, newid是否有效 1092 if !(FileDescriptorVec::validate_fd(oldfd) && FileDescriptorVec::validate_fd(newfd)) { 1093 return Err(SystemError::EBADF); 1094 } 1095 1096 if oldfd == newfd { 1097 // 若oldfd与newfd相等 1098 return Ok(newfd as usize); 1099 } 1100 let new_exists = fd_table_guard.get_file_by_fd(newfd).is_some(); 1101 if new_exists { 1102 // close newfd 1103 if fd_table_guard.drop_fd(newfd).is_err() { 1104 // An I/O error occurred while attempting to close fildes2. 1105 return Err(SystemError::EIO); 1106 } 1107 } 1108 1109 let old_file = fd_table_guard 1110 .get_file_by_fd(oldfd) 1111 .ok_or(SystemError::EBADF)?; 1112 let new_file = old_file.try_clone().ok_or(SystemError::EBADF)?; 1113 1114 if flags.contains(FileMode::O_CLOEXEC) { 1115 new_file.set_close_on_exec(true); 1116 } else { 1117 new_file.set_close_on_exec(false); 1118 } 1119 // 申请文件描述符，并把文件对象存入其中 1120 let res = fd_table_guard 1121 .alloc_fd(new_file, Some(newfd)) 1122 .map(|x| x as usize); 1123 return res; 1124 } 1125 1126 /// # fcntl 1127 /// 1128 /// ## 参数 1129 /// 1130 /// - `fd`：文件描述符 1131 /// - `cmd`：命令 1132 /// - `arg`：参数 1133 pub fn fcntl(fd: i32, cmd: FcntlCommand, arg: i32) -> Result<usize, SystemError> { 1134 // debug!("fcntl ({cmd:?}) fd: {fd}, arg={arg}"); 1135 match cmd { 1136 FcntlCommand::DupFd | FcntlCommand::DupFdCloexec => { 1137 if arg < 0 || arg as usize >= FileDescriptorVec::PROCESS_MAX_FD { 1138 return Err(SystemError::EBADF); 1139 } 1140 let arg = arg as usize; 1141 for i in arg..FileDescriptorVec::PROCESS_MAX_FD { 1142 let binding = ProcessManager::current_pcb().fd_table(); 1143 let mut fd_table_guard = binding.write(); 1144 if fd_table_guard.get_file_by_fd(i as i32).is_none() { 1145 if cmd == FcntlCommand::DupFd { 1146 return Self::do_dup2(fd, i as i32, &mut fd_table_guard); 1147 } else { 1148 return Self::do_dup3( 1149 fd, 1150 i as i32, 1151 FileMode::O_CLOEXEC, 1152 &mut fd_table_guard, 1153 ); 1154 } 1155 } 1156 } 1157 return Err(SystemError::EMFILE); 1158 } 1159 FcntlCommand::GetFd => { 1160 // Get file descriptor flags. 1161 let binding = ProcessManager::current_pcb().fd_table(); 1162 let fd_table_guard = binding.read(); 1163 1164 if let Some(file) = fd_table_guard.get_file_by_fd(fd) { 1165 // drop guard 以避免无法调度的问题 1166 drop(fd_table_guard); 1167 1168 if file.close_on_exec() { 1169 return Ok(FD_CLOEXEC as usize); 1170 } else { 1171 return Ok(0); 1172 } 1173 } 1174 return Err(SystemError::EBADF); 1175 } 1176 FcntlCommand::SetFd => { 1177 // Set file descriptor 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 // drop guard 以避免无法调度的问题 1183 drop(fd_table_guard); 1184 let arg = arg as u32; 1185 if arg & FD_CLOEXEC != 0 { 1186 file.set_close_on_exec(true); 1187 } else { 1188 file.set_close_on_exec(false); 1189 } 1190 return Ok(0); 1191 } 1192 return Err(SystemError::EBADF); 1193 } 1194 1195 FcntlCommand::GetFlags => { 1196 // Get file status flags. 1197 let binding = ProcessManager::current_pcb().fd_table(); 1198 let fd_table_guard = binding.read(); 1199 1200 if let Some(file) = fd_table_guard.get_file_by_fd(fd) { 1201 // drop guard 以避免无法调度的问题 1202 drop(fd_table_guard); 1203 return Ok(file.mode().bits() as usize); 1204 } 1205 1206 return Err(SystemError::EBADF); 1207 } 1208 FcntlCommand::SetFlags => { 1209 // Set file status flags. 1210 let binding = ProcessManager::current_pcb().fd_table(); 1211 let fd_table_guard = binding.write(); 1212 1213 if let Some(file) = fd_table_guard.get_file_by_fd(fd) { 1214 let arg = arg as u32; 1215 let mode = FileMode::from_bits(arg).ok_or(SystemError::EINVAL)?; 1216 // drop guard 以避免无法调度的问题 1217 drop(fd_table_guard); 1218 file.set_mode(mode)?; 1219 return Ok(0); 1220 } 1221 1222 return Err(SystemError::EBADF); 1223 } 1224 _ => { 1225 // TODO: unimplemented 1226 // 未实现的命令，返回0，不报错。 1227 1228 warn!("fcntl: unimplemented command: {:?}, defaults to 0.", cmd); 1229 return Err(SystemError::ENOSYS); 1230 } 1231 } 1232 } 1233 1234 /// # ftruncate 1235 /// 1236 /// ## 描述 1237 /// 1238 /// 改变文件大小. 1239 /// 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. 1240 /// 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. 1241 /// 1242 /// ## 参数 1243 /// 1244 /// - `fd`：文件描述符 1245 /// - `len`：文件大小 1246 /// 1247 /// ## 返回值 1248 /// 1249 /// 如果成功，返回0，否则返回错误码. 1250 pub fn ftruncate(fd: i32, len: usize) -> Result<usize, SystemError> { 1251 let binding = ProcessManager::current_pcb().fd_table(); 1252 let fd_table_guard = binding.read(); 1253 1254 if let Some(file) = fd_table_guard.get_file_by_fd(fd) { 1255 // drop guard 以避免无法调度的问题 1256 drop(fd_table_guard); 1257 let r = file.ftruncate(len).map(|_| 0); 1258 return r; 1259 } 1260 1261 return Err(SystemError::EBADF); 1262 } 1263 1264 fn do_fstat(fd: i32) -> Result<PosixKstat, SystemError> { 1265 let binding = ProcessManager::current_pcb().fd_table(); 1266 let fd_table_guard = binding.read(); 1267 let file = fd_table_guard 1268 .get_file_by_fd(fd) 1269 .ok_or(SystemError::EBADF)?; 1270 // drop guard 以避免无法调度的问题 1271 drop(fd_table_guard); 1272 1273 let mut kstat = PosixKstat::new(); 1274 // 获取文件信息 1275 let metadata = file.metadata()?; 1276 kstat.size = metadata.size; 1277 kstat.dev_id = metadata.dev_id as u64; 1278 kstat.inode = metadata.inode_id.into() as u64; 1279 kstat.blcok_size = metadata.blk_size as i64; 1280 kstat.blocks = metadata.blocks as u64; 1281 1282 kstat.atime.tv_sec = metadata.atime.tv_sec; 1283 kstat.atime.tv_nsec = metadata.atime.tv_nsec; 1284 kstat.mtime.tv_sec = metadata.mtime.tv_sec; 1285 kstat.mtime.tv_nsec = metadata.mtime.tv_nsec; 1286 kstat.ctime.tv_sec = metadata.ctime.tv_sec; 1287 kstat.ctime.tv_nsec = metadata.ctime.tv_nsec; 1288 1289 kstat.nlink = metadata.nlinks as u64; 1290 kstat.uid = metadata.uid as i32; 1291 kstat.gid = metadata.gid as i32; 1292 kstat.rdev = metadata.raw_dev.data() as i64; 1293 kstat.mode = metadata.mode; 1294 match file.file_type() { 1295 FileType::File => kstat.mode.insert(ModeType::S_IFREG), 1296 FileType::Dir => kstat.mode.insert(ModeType::S_IFDIR), 1297 FileType::BlockDevice => kstat.mode.insert(ModeType::S_IFBLK), 1298 FileType::CharDevice => kstat.mode.insert(ModeType::S_IFCHR), 1299 FileType::SymLink => kstat.mode.insert(ModeType::S_IFLNK), 1300 FileType::Socket => kstat.mode.insert(ModeType::S_IFSOCK), 1301 FileType::Pipe => kstat.mode.insert(ModeType::S_IFIFO), 1302 FileType::KvmDevice => kstat.mode.insert(ModeType::S_IFCHR), 1303 FileType::FramebufferDevice => kstat.mode.insert(ModeType::S_IFCHR), 1304 } 1305 1306 return Ok(kstat); 1307 } 1308 1309 pub fn fstat(fd: i32, usr_kstat: *mut PosixKstat) -> Result<usize, SystemError> { 1310 let mut writer = UserBufferWriter::new(usr_kstat, size_of::<PosixKstat>(), true)?; 1311 let kstat = Self::do_fstat(fd)?; 1312 1313 writer.copy_one_to_user(&kstat, 0)?; 1314 return Ok(0); 1315 } 1316 1317 pub fn stat(path: *const u8, user_kstat: *mut PosixKstat) -> Result<usize, SystemError> { 1318 let fd = Self::open( 1319 path, 1320 FileMode::O_RDONLY.bits(), 1321 ModeType::empty().bits(), 1322 true, 1323 )?; 1324 let r = Self::fstat(fd as i32, user_kstat); 1325 Self::close(fd).ok(); 1326 return r; 1327 } 1328 1329 pub fn lstat(path: *const u8, user_kstat: *mut PosixKstat) -> Result<usize, SystemError> { 1330 let fd = Self::open( 1331 path, 1332 FileMode::O_RDONLY.bits(), 1333 ModeType::empty().bits(), 1334 false, 1335 )?; 1336 let r = Self::fstat(fd as i32, user_kstat); 1337 Self::close(fd).ok(); 1338 return r; 1339 } 1340 1341 pub fn statfs(path: *const u8, user_statfs: *mut PosixStatfs) -> Result<usize, SystemError> { 1342 let mut writer = UserBufferWriter::new(user_statfs, size_of::<PosixStatfs>(), true)?; 1343 let fd = Self::open( 1344 path, 1345 FileMode::O_RDONLY.bits(), 1346 ModeType::empty().bits(), 1347 true, 1348 )?; 1349 let path = check_and_clone_cstr(path, Some(MAX_PATHLEN)) 1350 .unwrap() 1351 .into_string() 1352 .map_err(|_| SystemError::EINVAL)?; 1353 let pcb = ProcessManager::current_pcb(); 1354 let (_inode_begin, remain_path) = user_path_at(&pcb, fd as i32, &path)?; 1355 let inode = ROOT_INODE().lookup_follow_symlink(&remain_path, MAX_PATHLEN)?; 1356 let statfs = PosixStatfs::from(inode.fs().super_block()); 1357 writer.copy_one_to_user(&statfs, 0)?; 1358 return Ok(0); 1359 } 1360 1361 pub fn fstatfs(fd: i32, user_statfs: *mut PosixStatfs) -> Result<usize, SystemError> { 1362 let mut writer = UserBufferWriter::new(user_statfs, size_of::<PosixStatfs>(), true)?; 1363 let binding = ProcessManager::current_pcb().fd_table(); 1364 let fd_table_guard = binding.read(); 1365 let file = fd_table_guard 1366 .get_file_by_fd(fd) 1367 .ok_or(SystemError::EBADF)?; 1368 drop(fd_table_guard); 1369 let statfs = PosixStatfs::from(file.inode().fs().super_block()); 1370 writer.copy_one_to_user(&statfs, 0)?; 1371 return Ok(0); 1372 } 1373 1374 pub fn do_statx( 1375 fd: i32, 1376 path: *const u8, 1377 flags: u32, 1378 mask: u32, 1379 usr_kstat: *mut PosixStatx, 1380 ) -> Result<usize, SystemError> { 1381 if usr_kstat.is_null() { 1382 return Err(SystemError::EFAULT); 1383 } 1384 1385 let mask = PosixStatxMask::from_bits_truncate(mask); 1386 1387 if mask.contains(PosixStatxMask::STATX_RESERVED) { 1388 return Err(SystemError::ENAVAIL); 1389 } 1390 1391 let flags = FileMode::from_bits_truncate(flags); 1392 let ofd = Self::open(path, flags.bits(), ModeType::empty().bits, true)?; 1393 1394 let binding = ProcessManager::current_pcb().fd_table(); 1395 let fd_table_guard = binding.read(); 1396 let file = fd_table_guard 1397 .get_file_by_fd(ofd as i32) 1398 .ok_or(SystemError::EBADF)?; 1399 // drop guard 以避免无法调度的问题 1400 drop(fd_table_guard); 1401 let mut writer = UserBufferWriter::new(usr_kstat, size_of::<PosixStatx>(), true)?; 1402 let mut tmp: PosixStatx = PosixStatx::new(); 1403 // 获取文件信息 1404 let metadata = file.metadata()?; 1405 1406 tmp.stx_mask |= PosixStatxMask::STATX_BASIC_STATS; 1407 tmp.stx_blksize = metadata.blk_size as u32; 1408 if mask.contains(PosixStatxMask::STATX_MODE) || mask.contains(PosixStatxMask::STATX_TYPE) { 1409 tmp.stx_mode = metadata.mode; 1410 } 1411 if mask.contains(PosixStatxMask::STATX_NLINK) { 1412 tmp.stx_nlink = metadata.nlinks as u32; 1413 } 1414 if mask.contains(PosixStatxMask::STATX_UID) { 1415 tmp.stx_uid = metadata.uid as u32; 1416 } 1417 if mask.contains(PosixStatxMask::STATX_GID) { 1418 tmp.stx_gid = metadata.gid as u32; 1419 } 1420 if mask.contains(PosixStatxMask::STATX_ATIME) { 1421 tmp.stx_atime.tv_sec = metadata.atime.tv_sec; 1422 tmp.stx_atime.tv_nsec = metadata.atime.tv_nsec; 1423 } 1424 if mask.contains(PosixStatxMask::STATX_MTIME) { 1425 tmp.stx_mtime.tv_sec = metadata.ctime.tv_sec; 1426 tmp.stx_mtime.tv_nsec = metadata.ctime.tv_nsec; 1427 } 1428 if mask.contains(PosixStatxMask::STATX_CTIME) { 1429 // ctime是文件上次修改状态的时间 1430 tmp.stx_ctime.tv_sec = metadata.mtime.tv_sec; 1431 tmp.stx_ctime.tv_nsec = metadata.mtime.tv_nsec; 1432 } 1433 if mask.contains(PosixStatxMask::STATX_INO) { 1434 tmp.stx_inode = metadata.inode_id.into() as u64; 1435 } 1436 if mask.contains(PosixStatxMask::STATX_SIZE) { 1437 tmp.stx_size = metadata.size; 1438 } 1439 if mask.contains(PosixStatxMask::STATX_BLOCKS) { 1440 tmp.stx_blocks = metadata.blocks as u64; 1441 } 1442 1443 if mask.contains(PosixStatxMask::STATX_BTIME) { 1444 // btime是文件创建时间 1445 tmp.stx_btime.tv_sec = metadata.ctime.tv_sec; 1446 tmp.stx_btime.tv_nsec = metadata.ctime.tv_nsec; 1447 } 1448 if mask.contains(PosixStatxMask::STATX_ALL) { 1449 tmp.stx_attributes = StxAttributes::STATX_ATTR_APPEND; 1450 tmp.stx_attributes_mask |= 1451 StxAttributes::STATX_ATTR_AUTOMOUNT | StxAttributes::STATX_ATTR_DAX; 1452 tmp.stx_dev_major = metadata.dev_id as u32; 1453 tmp.stx_dev_minor = metadata.dev_id as u32; // 1454 tmp.stx_rdev_major = metadata.raw_dev.data(); 1455 tmp.stx_rdev_minor = metadata.raw_dev.data(); 1456 } 1457 if mask.contains(PosixStatxMask::STATX_MNT_ID) { 1458 tmp.stx_mnt_id = 0; 1459 } 1460 if mask.contains(PosixStatxMask::STATX_DIOALIGN) { 1461 tmp.stx_dio_mem_align = 0; 1462 tmp.stx_dio_offset_align = 0; 1463 } 1464 1465 match file.file_type() { 1466 FileType::File => tmp.stx_mode.insert(ModeType::S_IFREG), 1467 FileType::Dir => tmp.stx_mode.insert(ModeType::S_IFDIR), 1468 FileType::BlockDevice => tmp.stx_mode.insert(ModeType::S_IFBLK), 1469 FileType::CharDevice => tmp.stx_mode.insert(ModeType::S_IFCHR), 1470 FileType::SymLink => tmp.stx_mode.insert(ModeType::S_IFLNK), 1471 FileType::Socket => tmp.stx_mode.insert(ModeType::S_IFSOCK), 1472 FileType::Pipe => tmp.stx_mode.insert(ModeType::S_IFIFO), 1473 FileType::KvmDevice => tmp.stx_mode.insert(ModeType::S_IFCHR), 1474 FileType::FramebufferDevice => tmp.stx_mode.insert(ModeType::S_IFCHR), 1475 } 1476 1477 writer.copy_one_to_user(&tmp, 0)?; 1478 Self::close(fd as usize).ok(); 1479 return Ok(0); 1480 } 1481 1482 pub fn mknod( 1483 path: *const u8, 1484 mode: ModeType, 1485 dev_t: DeviceNumber, 1486 ) -> Result<usize, SystemError> { 1487 let path = check_and_clone_cstr(path, Some(MAX_PATHLEN))? 1488 .into_string() 1489 .map_err(|_| SystemError::EINVAL)?; 1490 let path = path.as_str().trim(); 1491 1492 let inode: Result<Arc<dyn IndexNode>, SystemError> = 1493 ROOT_INODE().lookup_follow_symlink(path, VFS_MAX_FOLLOW_SYMLINK_TIMES); 1494 1495 if inode.is_ok() { 1496 return Err(SystemError::EEXIST); 1497 } 1498 1499 let (filename, parent_path) = rsplit_path(path); 1500 1501 // 查找父目录 1502 let parent_inode: Arc<dyn IndexNode> = ROOT_INODE() 1503 .lookup_follow_symlink(parent_path.unwrap_or("/"), VFS_MAX_FOLLOW_SYMLINK_TIMES)?; 1504 // 创建nod 1505 parent_inode.mknod(filename, mode, dev_t)?; 1506 1507 return Ok(0); 1508 } 1509 1510 pub fn writev(fd: i32, iov: usize, count: usize) -> Result<usize, SystemError> { 1511 // IoVecs会进行用户态检验 1512 let iovecs = unsafe { IoVecs::from_user(iov as *const IoVec, count, false) }?; 1513 1514 let data = iovecs.gather(); 1515 1516 Self::write(fd, &data) 1517 } 1518 1519 pub fn readv(fd: i32, iov: usize, count: usize) -> Result<usize, SystemError> { 1520 // IoVecs会进行用户态检验 1521 let mut iovecs = unsafe { IoVecs::from_user(iov as *const IoVec, count, true) }?; 1522 1523 let mut data = vec![0; iovecs.0.iter().map(|x| x.len()).sum()]; 1524 1525 let len = Self::read(fd, &mut data)?; 1526 1527 iovecs.scatter(&data[..len]); 1528 1529 return Ok(len); 1530 } 1531 1532 pub fn readlink_at( 1533 dirfd: i32, 1534 path: *const u8, 1535 user_buf: *mut u8, 1536 buf_size: usize, 1537 ) -> Result<usize, SystemError> { 1538 let path = check_and_clone_cstr(path, Some(MAX_PATHLEN))? 1539 .into_string() 1540 .map_err(|_| SystemError::EINVAL)?; 1541 let path = path.as_str().trim(); 1542 let mut user_buf = UserBufferWriter::new(user_buf, buf_size, true)?; 1543 1544 let (inode, path) = user_path_at(&ProcessManager::current_pcb(), dirfd, path)?; 1545 1546 let inode = inode.lookup(path.as_str())?; 1547 if inode.metadata()?.file_type != FileType::SymLink { 1548 return Err(SystemError::EINVAL); 1549 } 1550 1551 let ubuf = user_buf.buffer::<u8>(0).unwrap(); 1552 1553 let file = File::new(inode, FileMode::O_RDONLY)?; 1554 1555 let len = file.read(buf_size, ubuf)?; 1556 1557 return Ok(len); 1558 } 1559 1560 pub fn readlink( 1561 path: *const u8, 1562 user_buf: *mut u8, 1563 buf_size: usize, 1564 ) -> Result<usize, SystemError> { 1565 return Self::readlink_at(AtFlags::AT_FDCWD.bits(), path, user_buf, buf_size); 1566 } 1567 1568 pub fn access(pathname: *const u8, mode: u32) -> Result<usize, SystemError> { 1569 return do_faccessat( 1570 AtFlags::AT_FDCWD.bits(), 1571 pathname, 1572 ModeType::from_bits(mode).ok_or(SystemError::EINVAL)?, 1573 0, 1574 ); 1575 } 1576 1577 pub fn faccessat2( 1578 dirfd: i32, 1579 pathname: *const u8, 1580 mode: u32, 1581 flags: u32, 1582 ) -> Result<usize, SystemError> { 1583 return do_faccessat( 1584 dirfd, 1585 pathname, 1586 ModeType::from_bits(mode).ok_or(SystemError::EINVAL)?, 1587 flags, 1588 ); 1589 } 1590 1591 pub fn chmod(pathname: *const u8, mode: u32) -> Result<usize, SystemError> { 1592 return do_fchmodat( 1593 AtFlags::AT_FDCWD.bits(), 1594 pathname, 1595 ModeType::from_bits(mode).ok_or(SystemError::EINVAL)?, 1596 ); 1597 } 1598 1599 pub fn fchmodat(dirfd: i32, pathname: *const u8, mode: u32) -> Result<usize, SystemError> { 1600 return do_fchmodat( 1601 dirfd, 1602 pathname, 1603 ModeType::from_bits(mode).ok_or(SystemError::EINVAL)?, 1604 ); 1605 } 1606 1607 pub fn fchmod(fd: i32, mode: u32) -> Result<usize, SystemError> { 1608 let _mode = ModeType::from_bits(mode).ok_or(SystemError::EINVAL)?; 1609 let binding = ProcessManager::current_pcb().fd_table(); 1610 let fd_table_guard = binding.read(); 1611 let _file = fd_table_guard 1612 .get_file_by_fd(fd) 1613 .ok_or(SystemError::EBADF)?; 1614 1615 // fchmod没完全实现，因此不修改文件的权限 1616 // todo: 实现fchmod 1617 warn!("fchmod not fully implemented"); 1618 return Ok(0); 1619 } 1620 /// #挂载文件系统 1621 /// 1622 /// 用于挂载文件系统,目前仅支持ramfs挂载 1623 /// 1624 /// ## 参数: 1625 /// 1626 /// - source 挂载设备(暂时不支持) 1627 /// - target 挂载目录 1628 /// - filesystemtype 文件系统 1629 /// - mountflags 挂载选项（暂未实现） 1630 /// - data 带数据挂载 1631 /// 1632 /// ## 返回值 1633 /// - Ok(0): 挂载成功 1634 /// - Err(SystemError) :挂载过程中出错 1635 pub fn mount( 1636 _source: *const u8, 1637 target: *const u8, 1638 filesystemtype: *const u8, 1639 _mountflags: usize, 1640 _data: *const c_void, 1641 ) -> Result<usize, SystemError> { 1642 let target = user_access::check_and_clone_cstr(target, Some(MAX_PATHLEN))? 1643 .into_string() 1644 .map_err(|_| SystemError::EINVAL)?; 1645 1646 let fstype_str = user_access::check_and_clone_cstr(filesystemtype, Some(MAX_PATHLEN))?; 1647 let fstype_str = fstype_str.to_str().map_err(|_| SystemError::EINVAL)?; 1648 1649 let fstype = producefs!(FSMAKER, fstype_str)?; 1650 1651 Vcore::do_mount(fstype, &target)?; 1652 1653 return Ok(0); 1654 } 1655 1656 // 想法：可以在VFS中实现一个文件系统分发器，流程如下： 1657 // 1. 接受从上方传来的文件类型字符串 1658 // 2. 将传入值与启动时准备好的字符串数组逐个比较（probe） 1659 // 3. 直接在函数内调用构造方法并直接返回文件系统对象 1660 1661 /// src/linux/mount.c `umount` & `umount2` 1662 /// 1663 /// [umount(2) — Linux manual page](https://www.man7.org/linux/man-pages/man2/umount.2.html) 1664 pub fn umount2(target: *const u8, flags: i32) -> Result<(), SystemError> { 1665 let target = user_access::check_and_clone_cstr(target, Some(MAX_PATHLEN))? 1666 .into_string() 1667 .map_err(|_| SystemError::EINVAL)?; 1668 Vcore::do_umount2( 1669 AtFlags::AT_FDCWD.bits(), 1670 &target, 1671 UmountFlag::from_bits(flags).ok_or(SystemError::EINVAL)?, 1672 )?; 1673 return Ok(()); 1674 } 1675 1676 pub fn sys_utimensat( 1677 dirfd: i32, 1678 pathname: *const u8, 1679 times: *const PosixTimeSpec, 1680 flags: u32, 1681 ) -> Result<usize, SystemError> { 1682 let pathname = if pathname.is_null() { 1683 None 1684 } else { 1685 let pathname = check_and_clone_cstr(pathname, Some(MAX_PATHLEN))? 1686 .into_string() 1687 .map_err(|_| SystemError::EINVAL)?; 1688 Some(pathname) 1689 }; 1690 let flags = UtimensFlags::from_bits(flags).ok_or(SystemError::EINVAL)?; 1691 let times = if times.is_null() { 1692 None 1693 } else { 1694 let times_reader = UserBufferReader::new(times, size_of::<PosixTimeSpec>() * 2, true)?; 1695 let times = times_reader.read_from_user::<PosixTimeSpec>(0)?; 1696 Some([times[0], times[1]]) 1697 }; 1698 do_utimensat(dirfd, pathname, times, flags) 1699 } 1700 1701 pub fn sys_utimes( 1702 pathname: *const u8, 1703 times: *const PosixTimeval, 1704 ) -> Result<usize, SystemError> { 1705 let pathname = check_and_clone_cstr(pathname, Some(MAX_PATHLEN))? 1706 .into_string() 1707 .map_err(|_| SystemError::EINVAL)?; 1708 let times = if times.is_null() { 1709 None 1710 } else { 1711 let times_reader = UserBufferReader::new(times, size_of::<PosixTimeval>() * 2, true)?; 1712 let times = times_reader.read_from_user::<PosixTimeval>(0)?; 1713 Some([times[0], times[1]]) 1714 }; 1715 do_utimes(&pathname, times) 1716 } 1717 } 1718 1719 #[repr(C)] 1720 #[derive(Debug, Clone, Copy)] 1721 pub struct IoVec { 1722 /// 缓冲区的起始地址 1723 pub iov_base: *mut u8, 1724 /// 缓冲区的长度 1725 pub iov_len: usize, 1726 } 1727 1728 /// 用于存储多个来自用户空间的IoVec 1729 /// 1730 /// 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。 1731 /// TODO：支持分散读写 1732 #[derive(Debug)] 1733 pub struct IoVecs(Vec<&'static mut [u8]>); 1734 1735 impl IoVecs { 1736 /// 从用户空间的IoVec中构造IoVecs 1737 /// 1738 /// @param iov 用户空间的IoVec 1739 /// @param iovcnt 用户空间的IoVec的数量 1740 /// @param readv 是否为readv系统调用 1741 /// 1742 /// @return 构造成功返回IoVecs，否则返回错误码 1743 pub unsafe fn from_user( 1744 iov: *const IoVec, 1745 iovcnt: usize, 1746 _readv: bool, 1747 ) -> Result<Self, SystemError> { 1748 // 检查iov指针所在空间是否合法 1749 verify_area( 1750 VirtAddr::new(iov as usize), 1751 iovcnt * core::mem::size_of::<IoVec>(), 1752 ) 1753 .map_err(|_| SystemError::EFAULT)?; 1754 1755 // 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） 1756 let iovs: &[IoVec] = core::slice::from_raw_parts(iov, iovcnt); 1757 1758 let mut slices: Vec<&mut [u8]> = Vec::with_capacity(iovs.len()); 1759 1760 for iov in iovs.iter() { 1761 if iov.iov_len == 0 { 1762 continue; 1763 } 1764 1765 verify_area( 1766 VirtAddr::new(iov.iov_base as usize), 1767 iovcnt * core::mem::size_of::<IoVec>(), 1768 ) 1769 .map_err(|_| SystemError::EFAULT)?; 1770 1771 slices.push(core::slice::from_raw_parts_mut(iov.iov_base, iov.iov_len)); 1772 } 1773 1774 return Ok(Self(slices)); 1775 } 1776 1777 /// @brief 将IoVecs中的数据聚合到一个缓冲区中 1778 /// 1779 /// @return 返回聚合后的缓冲区 1780 pub fn gather(&self) -> Vec<u8> { 1781 let mut buf = Vec::new(); 1782 for slice in self.0.iter() { 1783 buf.extend_from_slice(slice); 1784 } 1785 return buf; 1786 } 1787 1788 /// @brief 将给定的数据分散写入到IoVecs中 1789 pub fn scatter(&mut self, data: &[u8]) { 1790 let mut data: &[u8] = data; 1791 for slice in self.0.iter_mut() { 1792 let len = core::cmp::min(slice.len(), data.len()); 1793 if len == 0 { 1794 continue; 1795 } 1796 1797 slice[..len].copy_from_slice(&data[..len]); 1798 data = &data[len..]; 1799 } 1800 } 1801 1802 /// @brief 创建与IoVecs等长的缓冲区 1803 /// 1804 /// @param set_len 是否设置返回的Vec的len。 1805 /// 如果为true，则返回的Vec的len为所有IoVec的长度之和; 1806 /// 否则返回的Vec的len为0，capacity为所有IoVec的长度之和. 1807 /// 1808 /// @return 返回创建的缓冲区 1809 pub fn new_buf(&self, set_len: bool) -> Vec<u8> { 1810 let total_len: usize = self.0.iter().map(|slice| slice.len()).sum(); 1811 let mut buf: Vec<u8> = Vec::with_capacity(total_len); 1812 1813 if set_len { 1814 buf.resize(total_len, 0); 1815 } 1816 return buf; 1817 } 1818 } 1819