1 use core::ffi::c_void; 2 use core::mem::size_of; 3 4 use alloc::string::ToString; 5 use alloc::{string::String, sync::Arc, vec::Vec}; 6 use system_error::SystemError; 7 8 use crate::producefs; 9 use crate::{ 10 driver::base::{block::SeekFrom, device::device_number::DeviceNumber}, 11 filesystem::vfs::{core as Vcore, file::FileDescriptorVec}, 12 kerror, 13 libs::rwlock::RwLockWriteGuard, 14 mm::{verify_area, VirtAddr}, 15 process::ProcessManager, 16 syscall::{ 17 user_access::{self, check_and_clone_cstr, UserBufferWriter}, 18 Syscall, 19 }, 20 time::PosixTimeSpec, 21 }; 22 23 use super::{ 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}, 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 // use crate::kdebug; 33 34 pub const SEEK_SET: u32 = 0; 35 pub const SEEK_CUR: u32 = 1; 36 pub const SEEK_END: u32 = 2; 37 pub const SEEK_MAX: u32 = 3; 38 39 bitflags! { 40 /// 文件类型和权限 41 #[repr(C)] 42 pub struct ModeType: u32 { 43 /// 掩码 44 const S_IFMT = 0o0_170_000; 45 /// 文件类型 46 const S_IFSOCK = 0o140000; 47 const S_IFLNK = 0o120000; 48 const S_IFREG = 0o100000; 49 const S_IFBLK = 0o060000; 50 const S_IFDIR = 0o040000; 51 const S_IFCHR = 0o020000; 52 const S_IFIFO = 0o010000; 53 54 const S_ISUID = 0o004000; 55 const S_ISGID = 0o002000; 56 const S_ISVTX = 0o001000; 57 /// 文件用户权限 58 const S_IRWXU = 0o0700; 59 const S_IRUSR = 0o0400; 60 const S_IWUSR = 0o0200; 61 const S_IXUSR = 0o0100; 62 /// 文件组权限 63 const S_IRWXG = 0o0070; 64 const S_IRGRP = 0o0040; 65 const S_IWGRP = 0o0020; 66 const S_IXGRP = 0o0010; 67 /// 文件其他用户权限 68 const S_IRWXO = 0o0007; 69 const S_IROTH = 0o0004; 70 const S_IWOTH = 0o0002; 71 const S_IXOTH = 0o0001; 72 73 /// 0o777 74 const S_IRWXUGO = Self::S_IRWXU.bits | Self::S_IRWXG.bits | Self::S_IRWXO.bits; 75 /// 0o7777 76 const S_IALLUGO = Self::S_ISUID.bits | Self::S_ISGID.bits | Self::S_ISVTX.bits| Self::S_IRWXUGO.bits; 77 /// 0o444 78 const S_IRUGO = Self::S_IRUSR.bits | Self::S_IRGRP.bits | Self::S_IROTH.bits; 79 /// 0o222 80 const S_IWUGO = Self::S_IWUSR.bits | Self::S_IWGRP.bits | Self::S_IWOTH.bits; 81 /// 0o111 82 const S_IXUGO = Self::S_IXUSR.bits | Self::S_IXGRP.bits | Self::S_IXOTH.bits; 83 84 85 } 86 } 87 88 #[repr(C)] 89 #[derive(Clone, Copy)] 90 /// # 文件信息结构体 91 pub struct PosixKstat { 92 /// 硬件设备ID 93 dev_id: u64, 94 /// inode号 95 inode: u64, 96 /// 硬链接数 97 nlink: u64, 98 /// 文件权限 99 mode: ModeType, 100 /// 所有者用户ID 101 uid: i32, 102 /// 所有者组ID 103 gid: i32, 104 /// 设备ID 105 rdev: i64, 106 /// 文件大小 107 size: i64, 108 /// 文件系统块大小 109 blcok_size: i64, 110 /// 分配的512B块数 111 blocks: u64, 112 /// 最后访问时间 113 atime: PosixTimeSpec, 114 /// 最后修改时间 115 mtime: PosixTimeSpec, 116 /// 最后状态变化时间 117 ctime: PosixTimeSpec, 118 /// 用于填充结构体大小的空白数据 119 pub _pad: [i8; 24], 120 } 121 impl PosixKstat { 122 fn new() -> Self { 123 Self { 124 inode: 0, 125 dev_id: 0, 126 mode: ModeType { bits: 0 }, 127 nlink: 0, 128 uid: 0, 129 gid: 0, 130 rdev: 0, 131 size: 0, 132 atime: PosixTimeSpec { 133 tv_sec: 0, 134 tv_nsec: 0, 135 }, 136 mtime: PosixTimeSpec { 137 tv_sec: 0, 138 tv_nsec: 0, 139 }, 140 ctime: PosixTimeSpec { 141 tv_sec: 0, 142 tv_nsec: 0, 143 }, 144 blcok_size: 0, 145 blocks: 0, 146 _pad: Default::default(), 147 } 148 } 149 } 150 151 #[repr(C)] 152 #[derive(Clone, Copy)] 153 /// # 文件信息结构体X 154 pub struct PosixStatx { 155 /* 0x00 */ 156 stx_mask: PosixStatxMask, 157 /// 文件系统块大小 158 stx_blksize: u32, 159 /// Flags conveying information about the file [uncond] 160 stx_attributes: StxAttributes, 161 /* 0x10 */ 162 /// 硬链接数 163 stx_nlink: u32, 164 /// 所有者用户ID 165 stx_uid: u32, 166 /// 所有者组ID 167 stx_gid: u32, 168 /// 文件权限 169 stx_mode: ModeType, 170 171 /* 0x20 */ 172 /// inode号 173 stx_inode: u64, 174 /// 文件大小 175 stx_size: i64, 176 /// 分配的512B块数 177 stx_blocks: u64, 178 /// Mask to show what's supported in stx_attributes 179 stx_attributes_mask: StxAttributes, 180 181 /* 0x40 */ 182 /// 最后访问时间 183 stx_atime: PosixTimeSpec, 184 /// 文件创建时间 185 stx_btime: PosixTimeSpec, 186 /// 最后状态变化时间 187 stx_ctime: PosixTimeSpec, 188 /// 最后修改时间 189 stx_mtime: PosixTimeSpec, 190 191 /* 0x80 */ 192 /// 主设备ID 193 stx_rdev_major: u32, 194 /// 次设备ID 195 stx_rdev_minor: u32, 196 /// 主硬件设备ID 197 stx_dev_major: u32, 198 /// 次硬件设备ID 199 stx_dev_minor: u32, 200 201 /* 0x90 */ 202 stx_mnt_id: u64, 203 stx_dio_mem_align: u32, 204 stx_dio_offset_align: u32, 205 } 206 impl PosixStatx { 207 fn new() -> Self { 208 Self { 209 stx_mask: PosixStatxMask::STATX_BASIC_STATS, 210 stx_blksize: 0, 211 stx_attributes: StxAttributes::STATX_ATTR_APPEND, 212 stx_nlink: 0, 213 stx_uid: 0, 214 stx_gid: 0, 215 stx_mode: ModeType { bits: 0 }, 216 stx_inode: 0, 217 stx_size: 0, 218 stx_blocks: 0, 219 stx_attributes_mask: StxAttributes::STATX_ATTR_APPEND, 220 stx_atime: PosixTimeSpec { 221 tv_sec: 0, 222 tv_nsec: 0, 223 }, 224 stx_btime: PosixTimeSpec { 225 tv_sec: 0, 226 tv_nsec: 0, 227 }, 228 stx_ctime: PosixTimeSpec { 229 tv_sec: 0, 230 tv_nsec: 0, 231 }, 232 stx_mtime: PosixTimeSpec { 233 tv_sec: 0, 234 tv_nsec: 0, 235 }, 236 stx_rdev_major: 0, 237 stx_rdev_minor: 0, 238 stx_dev_major: 0, 239 stx_dev_minor: 0, 240 stx_mnt_id: 0, 241 stx_dio_mem_align: 0, 242 stx_dio_offset_align: 0, 243 } 244 } 245 } 246 247 bitflags! { 248 pub struct PosixStatxMask: u32{ 249 /// Want stx_mode & S_IFMT 250 const STATX_TYPE = 0x00000001; 251 252 /// Want stx_mode & ~S_IFMT 253 const STATX_MODE = 0x00000002; 254 255 /// Want stx_nlink 256 const STATX_NLINK = 0x00000004; 257 258 /// Want stx_uid 259 const STATX_UID = 0x00000008; 260 261 /// Want stx_gid 262 const STATX_GID = 0x00000010; 263 264 /// Want stx_atime 265 const STATX_ATIME = 0x00000020; 266 267 /// Want stx_mtime 268 const STATX_MTIME = 0x00000040; 269 270 /// Want stx_ctime 271 const STATX_CTIME = 0x00000080; 272 273 /// Want stx_ino 274 const STATX_INO = 0x00000100; 275 276 /// Want stx_size 277 const STATX_SIZE = 0x00000200; 278 279 /// Want stx_blocks 280 const STATX_BLOCKS = 0x00000400; 281 282 /// [All of the above] 283 const STATX_BASIC_STATS = 0x000007ff; 284 285 /// Want stx_btime 286 const STATX_BTIME = 0x00000800; 287 288 /// The same as STATX_BASIC_STATS | STATX_BTIME. 289 /// It is deprecated and should not be used. 290 const STATX_ALL = 0x00000fff; 291 292 /// Want stx_mnt_id (since Linux 5.8) 293 const STATX_MNT_ID = 0x00001000; 294 295 /// Want stx_dio_mem_align and stx_dio_offset_align 296 /// (since Linux 6.1; support varies by filesystem) 297 const STATX_DIOALIGN = 0x00002000; 298 299 /// Reserved for future struct statx expansion 300 const STATX_RESERVED = 0x80000000; 301 } 302 } 303 304 bitflags! { 305 pub struct StxAttributes: u64 { 306 /// 文件被文件系统压缩 307 const STATX_ATTR_COMPRESSED = 0x00000004; 308 /// 文件被标记为不可修改 309 const STATX_ATTR_IMMUTABLE = 0x00000010; 310 /// 文件是只追加写入的 311 const STATX_ATTR_APPEND = 0x00000020; 312 /// 文件不会被备份 313 const STATX_ATTR_NODUMP = 0x00000040; 314 /// 文件需要密钥才能在文件系统中解密 315 const STATX_ATTR_ENCRYPTED = 0x00000800; 316 /// 目录是自动挂载触发器 317 const STATX_ATTR_AUTOMOUNT = 0x00001000; 318 /// 目录是挂载点的根目录 319 const STATX_ATTR_MOUNT_ROOT = 0x00002000; 320 /// 文件受到 Verity 保护 321 const STATX_ATTR_VERITY = 0x00100000; 322 /// 文件当前处于 DAX 状态 CPU直接访问 323 const STATX_ATTR_DAX = 0x00200000; 324 } 325 } 326 327 #[repr(C)] 328 #[derive(Debug, Clone, Copy)] 329 pub struct PosixStatfs { 330 f_type: u64, 331 f_bsize: u64, 332 f_blocks: u64, 333 f_bfree: u64, 334 f_bavail: u64, 335 f_files: u64, 336 f_ffree: u64, 337 f_fsid: u64, 338 f_namelen: u64, 339 f_frsize: u64, 340 f_flags: u64, 341 f_spare: [u64; 4], 342 } 343 344 impl From<SuperBlock> for PosixStatfs { 345 fn from(super_block: SuperBlock) -> Self { 346 Self { 347 f_type: super_block.magic.bits, 348 f_bsize: super_block.bsize, 349 f_blocks: super_block.blocks, 350 f_bfree: super_block.bfree, 351 f_bavail: super_block.bavail, 352 f_files: super_block.files, 353 f_ffree: super_block.ffree, 354 f_fsid: super_block.fsid, 355 f_namelen: super_block.namelen, 356 f_frsize: super_block.frsize, 357 f_flags: super_block.flags, 358 f_spare: [0u64; 4], 359 } 360 } 361 } 362 /// 363 /// Arguments for how openat2(2) should open the target path. If only @flags and 364 /// @mode are non-zero, then openat2(2) operates very similarly to openat(2). 365 /// 366 /// However, unlike openat(2), unknown or invalid bits in @flags result in 367 /// -EINVAL rather than being silently ignored. @mode must be zero unless one of 368 /// {O_CREAT, O_TMPFILE} are set. 369 /// 370 /// ## 成员变量 371 /// 372 /// - flags: O_* flags. 373 /// - mode: O_CREAT/O_TMPFILE file mode. 374 /// - resolve: RESOLVE_* flags. 375 #[derive(Debug, Clone, Copy)] 376 #[repr(C)] 377 pub struct PosixOpenHow { 378 pub flags: u64, 379 pub mode: u64, 380 pub resolve: u64, 381 } 382 383 impl PosixOpenHow { 384 #[allow(dead_code)] 385 pub fn new(flags: u64, mode: u64, resolve: u64) -> Self { 386 Self { 387 flags, 388 mode, 389 resolve, 390 } 391 } 392 } 393 394 #[derive(Debug, Clone, Copy)] 395 pub struct OpenHow { 396 pub o_flags: FileMode, 397 pub mode: ModeType, 398 pub resolve: OpenHowResolve, 399 } 400 401 impl OpenHow { 402 pub fn new(mut o_flags: FileMode, mut mode: ModeType, resolve: OpenHowResolve) -> Self { 403 if !o_flags.contains(FileMode::O_CREAT) { 404 mode = ModeType::empty(); 405 } 406 407 if o_flags.contains(FileMode::O_PATH) { 408 o_flags = o_flags.intersection(FileMode::O_PATH_FLAGS); 409 } 410 411 Self { 412 o_flags, 413 mode, 414 resolve, 415 } 416 } 417 } 418 419 impl From<PosixOpenHow> for OpenHow { 420 fn from(posix_open_how: PosixOpenHow) -> Self { 421 let o_flags = FileMode::from_bits_truncate(posix_open_how.flags as u32); 422 let mode = ModeType::from_bits_truncate(posix_open_how.mode as u32); 423 let resolve = OpenHowResolve::from_bits_truncate(posix_open_how.resolve); 424 return Self::new(o_flags, mode, resolve); 425 } 426 } 427 428 bitflags! { 429 pub struct OpenHowResolve: u64{ 430 /// Block mount-point crossings 431 /// (including bind-mounts). 432 const RESOLVE_NO_XDEV = 0x01; 433 434 /// Block traversal through procfs-style 435 /// "magic-links" 436 const RESOLVE_NO_MAGICLINKS = 0x02; 437 438 /// Block traversal through all symlinks 439 /// (implies OEXT_NO_MAGICLINKS) 440 const RESOLVE_NO_SYMLINKS = 0x04; 441 /// Block "lexical" trickery like 442 /// "..", symlinks, and absolute 443 const RESOLVE_BENEATH = 0x08; 444 /// Make all jumps to "/" and ".." 445 /// be scoped inside the dirfd 446 /// (similar to chroot(2)). 447 const RESOLVE_IN_ROOT = 0x10; 448 // Only complete if resolution can be 449 // completed through cached lookup. May 450 // return -EAGAIN if that's not 451 // possible. 452 const RESOLVE_CACHED = 0x20; 453 } 454 } 455 456 bitflags! { 457 pub struct UmountFlag: i32 { 458 const DEFAULT = 0; /* Default call to umount. */ 459 const MNT_FORCE = 1; /* Force unmounting. */ 460 const MNT_DETACH = 2; /* Just detach from the tree. */ 461 const MNT_EXPIRE = 4; /* Mark for expiry. */ 462 const UMOUNT_NOFOLLOW = 8; /* Don't follow symlink on umount. */ 463 } 464 } 465 466 impl Syscall { 467 /// @brief 为当前进程打开一个文件 468 /// 469 /// @param path 文件路径 470 /// @param o_flags 打开文件的标志位 471 /// 472 /// @return 文件描述符编号，或者是错误码 473 pub fn open( 474 path: *const u8, 475 o_flags: u32, 476 mode: u32, 477 follow_symlink: bool, 478 ) -> Result<usize, SystemError> { 479 let path = check_and_clone_cstr(path, Some(MAX_PATHLEN))?; 480 let open_flags: FileMode = FileMode::from_bits(o_flags).ok_or(SystemError::EINVAL)?; 481 let mode = ModeType::from_bits(mode).ok_or(SystemError::EINVAL)?; 482 return do_sys_open( 483 AtFlags::AT_FDCWD.bits(), 484 &path, 485 open_flags, 486 mode, 487 follow_symlink, 488 ); 489 } 490 491 pub fn openat( 492 dirfd: i32, 493 path: *const u8, 494 o_flags: u32, 495 mode: u32, 496 follow_symlink: bool, 497 ) -> Result<usize, SystemError> { 498 let path = check_and_clone_cstr(path, Some(MAX_PATHLEN))?; 499 let open_flags: FileMode = FileMode::from_bits(o_flags).ok_or(SystemError::EINVAL)?; 500 let mode = ModeType::from_bits(mode).ok_or(SystemError::EINVAL)?; 501 return do_sys_open(dirfd, &path, open_flags, mode, follow_symlink); 502 } 503 504 /// @brief 关闭文件 505 /// 506 /// @param fd 文件描述符编号 507 /// 508 /// @return 成功返回0，失败返回错误码 509 pub fn close(fd: usize) -> Result<usize, SystemError> { 510 let binding = ProcessManager::current_pcb().fd_table(); 511 let mut fd_table_guard = binding.write(); 512 513 fd_table_guard.drop_fd(fd as i32).map(|_| 0) 514 } 515 516 /// @brief 发送命令到文件描述符对应的设备， 517 /// 518 /// @param fd 文件描述符编号 519 /// @param cmd 设备相关的请求类型 520 /// 521 /// @return Ok(usize) 成功返回0 522 /// @return Err(SystemError) 读取失败，返回posix错误码 523 pub fn ioctl(fd: usize, cmd: u32, data: usize) -> Result<usize, SystemError> { 524 let binding = ProcessManager::current_pcb().fd_table(); 525 let fd_table_guard = binding.read(); 526 527 let file = fd_table_guard 528 .get_file_by_fd(fd as i32) 529 .ok_or(SystemError::EBADF)?; 530 531 // drop guard 以避免无法调度的问题 532 drop(fd_table_guard); 533 let r = file.inode().ioctl(cmd, data, &file.private_data.lock()); 534 return r; 535 } 536 537 /// @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。 538 /// 539 /// @param fd 文件描述符编号 540 /// @param buf 输出缓冲区 541 /// 542 /// @return Ok(usize) 成功读取的数据的字节数 543 /// @return Err(SystemError) 读取失败，返回posix错误码 544 pub fn read(fd: i32, buf: &mut [u8]) -> Result<usize, SystemError> { 545 let binding = ProcessManager::current_pcb().fd_table(); 546 let fd_table_guard = binding.read(); 547 548 let file = fd_table_guard.get_file_by_fd(fd); 549 if file.is_none() { 550 return Err(SystemError::EBADF); 551 } 552 // drop guard 以避免无法调度的问题 553 drop(fd_table_guard); 554 let file = file.unwrap(); 555 556 return file.read(buf.len(), buf); 557 } 558 559 /// @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。 560 /// 561 /// @param fd 文件描述符编号 562 /// @param buf 输入缓冲区 563 /// 564 /// @return Ok(usize) 成功写入的数据的字节数 565 /// @return Err(SystemError) 写入失败，返回posix错误码 566 pub fn write(fd: i32, buf: &[u8]) -> Result<usize, SystemError> { 567 let binding = ProcessManager::current_pcb().fd_table(); 568 let fd_table_guard = binding.read(); 569 570 let file = fd_table_guard 571 .get_file_by_fd(fd) 572 .ok_or(SystemError::EBADF)?; 573 574 // drop guard 以避免无法调度的问题 575 drop(fd_table_guard); 576 return file.write(buf.len(), buf); 577 } 578 579 /// @brief 调整文件操作指针的位置 580 /// 581 /// @param fd 文件描述符编号 582 /// @param seek 调整的方式 583 /// 584 /// @return Ok(usize) 调整后，文件访问指针相对于文件头部的偏移量 585 /// @return Err(SystemError) 调整失败，返回posix错误码 586 pub fn lseek(fd: i32, offset: i64, seek: u32) -> Result<usize, SystemError> { 587 let seek = match seek { 588 SEEK_SET => Ok(SeekFrom::SeekSet(offset)), 589 SEEK_CUR => Ok(SeekFrom::SeekCurrent(offset)), 590 SEEK_END => Ok(SeekFrom::SeekEnd(offset)), 591 SEEK_MAX => Ok(SeekFrom::SeekEnd(0)), 592 _ => Err(SystemError::EINVAL), 593 }?; 594 595 let binding = ProcessManager::current_pcb().fd_table(); 596 let fd_table_guard = binding.read(); 597 let file = fd_table_guard 598 .get_file_by_fd(fd) 599 .ok_or(SystemError::EBADF)?; 600 601 // drop guard 以避免无法调度的问题 602 drop(fd_table_guard); 603 return file.lseek(seek); 604 } 605 606 /// # sys_pread64 系统调用的实际执行函数 607 /// 608 /// ## 参数 609 /// - `fd`: 文件描述符 610 /// - `buf`: 读出缓冲区 611 /// - `len`: 要读取的字节数 612 /// - `offset`: 文件偏移量 613 pub fn pread(fd: i32, buf: &mut [u8], len: usize, offset: usize) -> Result<usize, SystemError> { 614 let binding = ProcessManager::current_pcb().fd_table(); 615 let fd_table_guard = binding.read(); 616 617 let file = fd_table_guard.get_file_by_fd(fd); 618 if file.is_none() { 619 return Err(SystemError::EBADF); 620 } 621 // drop guard 以避免无法调度的问题 622 drop(fd_table_guard); 623 let file = file.unwrap(); 624 625 return file.pread(offset, len, buf); 626 } 627 628 /// # sys_pwrite64 系统调用的实际执行函数 629 /// 630 /// ## 参数 631 /// - `fd`: 文件描述符 632 /// - `buf`: 写入缓冲区 633 /// - `len`: 要写入的字节数 634 /// - `offset`: 文件偏移量 635 pub fn pwrite(fd: i32, buf: &[u8], len: usize, offset: usize) -> Result<usize, SystemError> { 636 let binding = ProcessManager::current_pcb().fd_table(); 637 let fd_table_guard = binding.read(); 638 639 let file = fd_table_guard.get_file_by_fd(fd); 640 if file.is_none() { 641 return Err(SystemError::EBADF); 642 } 643 // drop guard 以避免无法调度的问题 644 drop(fd_table_guard); 645 let file = file.unwrap(); 646 647 return file.pwrite(offset, len, buf); 648 } 649 650 /// @brief 切换工作目录 651 /// 652 /// @param dest_path 目标路径 653 /// 654 /// @return 返回码 描述 655 /// 0 | 成功 656 /// 657 /// EACCESS | 权限不足 658 /// 659 /// ELOOP | 解析path时遇到路径循环 660 /// 661 /// ENAMETOOLONG | 路径名过长 662 /// 663 /// ENOENT | 目标文件或目录不存在 664 /// 665 /// ENODIR | 检索期间发现非目录项 666 /// 667 /// ENOMEM | 系统内存不足 668 /// 669 /// EFAULT | 错误的地址 670 /// 671 /// ENAMETOOLONG | 路径过长 672 pub fn chdir(path: *const u8) -> Result<usize, SystemError> { 673 if path.is_null() { 674 return Err(SystemError::EFAULT); 675 } 676 677 let path = check_and_clone_cstr(path, Some(MAX_PATHLEN))?; 678 let proc = ProcessManager::current_pcb(); 679 // Copy path to kernel space to avoid some security issues 680 let mut new_path = String::from(""); 681 if !path.is_empty() { 682 let cwd = match path.as_bytes()[0] { 683 b'/' => String::from("/"), 684 _ => proc.basic().cwd(), 685 }; 686 let mut cwd_vec: Vec<_> = cwd.split('/').filter(|&x| !x.is_empty()).collect(); 687 let path_split = path.split('/').filter(|&x| !x.is_empty()); 688 for seg in path_split { 689 if seg == ".." { 690 cwd_vec.pop(); 691 } else if seg == "." { 692 // 当前目录 693 } else { 694 cwd_vec.push(seg); 695 } 696 } 697 //proc.basic().set_path(String::from("")); 698 for seg in cwd_vec { 699 new_path.push('/'); 700 new_path.push_str(seg); 701 } 702 if new_path.is_empty() { 703 new_path = String::from("/"); 704 } 705 } 706 let inode = 707 match ROOT_INODE().lookup_follow_symlink(&new_path, VFS_MAX_FOLLOW_SYMLINK_TIMES) { 708 Err(_) => { 709 return Err(SystemError::ENOENT); 710 } 711 Ok(i) => i, 712 }; 713 let metadata = inode.metadata()?; 714 if metadata.file_type == FileType::Dir { 715 proc.basic_mut().set_cwd(new_path); 716 return Ok(0); 717 } else { 718 return Err(SystemError::ENOTDIR); 719 } 720 } 721 722 /// @brief 获取当前进程的工作目录路径 723 /// 724 /// @param buf 指向缓冲区的指针 725 /// @param size 缓冲区的大小 726 /// 727 /// @return 成功，返回的指针指向包含工作目录路径的字符串 728 /// @return 错误，没有足够的空间 729 pub fn getcwd(buf: &mut [u8]) -> Result<VirtAddr, SystemError> { 730 let proc = ProcessManager::current_pcb(); 731 let cwd = proc.basic().cwd(); 732 733 let cwd_bytes = cwd.as_bytes(); 734 let cwd_len = cwd_bytes.len(); 735 if cwd_len + 1 > buf.len() { 736 return Err(SystemError::ENOMEM); 737 } 738 buf[..cwd_len].copy_from_slice(cwd_bytes); 739 buf[cwd_len] = 0; 740 741 return Ok(VirtAddr::new(buf.as_ptr() as usize)); 742 } 743 744 /// @brief 获取目录中的数据 745 /// 746 /// TODO: 这个函数的语义与Linux不一致，需要修改！！！ 747 /// 748 /// @param fd 文件描述符号 749 /// @param buf 输出缓冲区 750 /// 751 /// @return 成功返回读取的字节数，失败返回错误码 752 pub fn getdents(fd: i32, buf: &mut [u8]) -> Result<usize, SystemError> { 753 let dirent = 754 unsafe { (buf.as_mut_ptr() as *mut Dirent).as_mut() }.ok_or(SystemError::EFAULT)?; 755 756 if fd < 0 || fd as usize > FileDescriptorVec::PROCESS_MAX_FD { 757 return Err(SystemError::EBADF); 758 } 759 760 // 获取fd 761 let binding = ProcessManager::current_pcb().fd_table(); 762 let fd_table_guard = binding.read(); 763 let file = fd_table_guard 764 .get_file_by_fd(fd) 765 .ok_or(SystemError::EBADF)?; 766 767 // drop guard 以避免无法调度的问题 768 drop(fd_table_guard); 769 770 let res = file.readdir(dirent).map(|x| x as usize); 771 772 return res; 773 } 774 775 /// @brief 创建文件夹 776 /// 777 /// @param path(r8) 路径 / mode(r9) 模式 778 /// 779 /// @return uint64_t 负数错误码 / 0表示成功 780 pub fn mkdir(path: *const u8, mode: usize) -> Result<usize, SystemError> { 781 let path = check_and_clone_cstr(path, Some(MAX_PATHLEN))?; 782 do_mkdir_at( 783 AtFlags::AT_FDCWD.bits(), 784 &path, 785 FileMode::from_bits_truncate(mode as u32), 786 )?; 787 return Ok(0); 788 } 789 790 /// **创建硬连接的系统调用** 791 /// 792 /// ## 参数 793 /// 794 /// - 'oldfd': 用于解析源文件路径的文件描述符 795 /// - 'old': 源文件路径 796 /// - 'newfd': 用于解析新文件路径的文件描述符 797 /// - 'new': 新文件将创建的路径 798 /// - 'flags': 标志位，仅以位或方式包含AT_EMPTY_PATH和AT_SYMLINK_FOLLOW 799 /// 800 /// 801 pub fn do_linkat( 802 oldfd: i32, 803 old: &str, 804 newfd: i32, 805 new: &str, 806 flags: AtFlags, 807 ) -> Result<usize, SystemError> { 808 // flag包含其他未规定值时返回EINVAL 809 if !(AtFlags::AT_EMPTY_PATH | AtFlags::AT_SYMLINK_FOLLOW).contains(flags) { 810 return Err(SystemError::EINVAL); 811 } 812 // TODO AT_EMPTY_PATH标志启用时，进行调用者CAP_DAC_READ_SEARCH或相似的检查 813 let symlink_times = if flags.contains(AtFlags::AT_SYMLINK_FOLLOW) { 814 0_usize 815 } else { 816 VFS_MAX_FOLLOW_SYMLINK_TIMES 817 }; 818 let pcb = ProcessManager::current_pcb(); 819 820 // 得到源路径的inode 821 let old_inode: Arc<dyn IndexNode> = if old.is_empty() { 822 if flags.contains(AtFlags::AT_EMPTY_PATH) { 823 // 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。 824 let binding = pcb.fd_table(); 825 let fd_table_guard = binding.read(); 826 let file = fd_table_guard 827 .get_file_by_fd(oldfd) 828 .ok_or(SystemError::EBADF)?; 829 let old_inode = file.inode(); 830 old_inode 831 } else { 832 return Err(SystemError::ENONET); 833 } 834 } else { 835 let (old_begin_inode, old_remain_path) = user_path_at(&pcb, oldfd, old)?; 836 old_begin_inode.lookup_follow_symlink(&old_remain_path, symlink_times)? 837 }; 838 839 // old_inode为目录时返回EPERM 840 if old_inode.metadata().unwrap().file_type == FileType::Dir { 841 return Err(SystemError::EPERM); 842 } 843 844 // 得到新创建节点的父节点 845 let (new_begin_inode, new_remain_path) = user_path_at(&pcb, newfd, new)?; 846 let (new_name, new_parent_path) = rsplit_path(&new_remain_path); 847 let new_parent = 848 new_begin_inode.lookup_follow_symlink(new_parent_path.unwrap_or("/"), symlink_times)?; 849 850 // 被调用者利用downcast_ref判断两inode是否为同一文件系统 851 return new_parent.link(new_name, &old_inode).map(|_| 0); 852 } 853 854 pub fn link(old: *const u8, new: *const u8) -> Result<usize, SystemError> { 855 let get_path = |cstr: *const u8| -> Result<String, SystemError> { 856 let res = check_and_clone_cstr(cstr, Some(MAX_PATHLEN))?; 857 if res.len() >= MAX_PATHLEN { 858 return Err(SystemError::ENAMETOOLONG); 859 } 860 if res.is_empty() { 861 return Err(SystemError::ENOENT); 862 } 863 Ok(res) 864 }; 865 let old = get_path(old)?; 866 let new = get_path(new)?; 867 return Self::do_linkat( 868 AtFlags::AT_FDCWD.bits(), 869 &old, 870 AtFlags::AT_FDCWD.bits(), 871 &new, 872 AtFlags::empty(), 873 ); 874 } 875 876 pub fn linkat( 877 oldfd: i32, 878 old: *const u8, 879 newfd: i32, 880 new: *const u8, 881 flags: i32, 882 ) -> Result<usize, SystemError> { 883 let old = check_and_clone_cstr(old, Some(MAX_PATHLEN))?; 884 let new = check_and_clone_cstr(new, Some(MAX_PATHLEN))?; 885 if old.len() >= MAX_PATHLEN || new.len() >= MAX_PATHLEN { 886 return Err(SystemError::ENAMETOOLONG); 887 } 888 // old 根据flags & AtFlags::AT_EMPTY_PATH判空 889 if new.is_empty() { 890 return Err(SystemError::ENOENT); 891 } 892 let flags = AtFlags::from_bits(flags).ok_or(SystemError::EINVAL)?; 893 Self::do_linkat(oldfd, &old, newfd, &new, flags) 894 } 895 896 /// **删除文件夹、取消文件的链接、删除文件的系统调用** 897 /// 898 /// ## 参数 899 /// 900 /// - `dirfd`：文件夹的文件描述符.目前暂未实现 901 /// - `pathname`：文件夹的路径 902 /// - `flags`：标志位 903 /// 904 /// 905 pub fn unlinkat(dirfd: i32, path: *const u8, flags: u32) -> Result<usize, SystemError> { 906 let flags = AtFlags::from_bits(flags as i32).ok_or(SystemError::EINVAL)?; 907 908 let path = check_and_clone_cstr(path, Some(MAX_PATHLEN))?; 909 910 if flags.contains(AtFlags::AT_REMOVEDIR) { 911 // kdebug!("rmdir"); 912 match do_remove_dir(dirfd, &path) { 913 Err(err) => { 914 return Err(err); 915 } 916 Ok(_) => { 917 return Ok(0); 918 } 919 } 920 } 921 922 match do_unlink_at(dirfd, &path) { 923 Err(err) => { 924 return Err(err); 925 } 926 Ok(_) => { 927 return Ok(0); 928 } 929 } 930 } 931 932 pub fn rmdir(path: *const u8) -> Result<usize, SystemError> { 933 let path = check_and_clone_cstr(path, Some(MAX_PATHLEN))?; 934 return do_remove_dir(AtFlags::AT_FDCWD.bits(), &path).map(|v| v as usize); 935 } 936 937 pub fn unlink(path: *const u8) -> Result<usize, SystemError> { 938 let path = check_and_clone_cstr(path, Some(MAX_PATHLEN))?; 939 return do_unlink_at(AtFlags::AT_FDCWD.bits(), &path).map(|v| v as usize); 940 } 941 942 /// # 修改文件名 943 /// 944 /// 945 /// ## 参数 946 /// 947 /// - oldfd: 源文件夹文件描述符 948 /// - filename_from: 源文件路径 949 /// - newfd: 目标文件夹文件描述符 950 /// - filename_to: 目标文件路径 951 /// - flags: 标志位 952 /// 953 /// 954 /// ## 返回值 955 /// - Ok(返回值类型): 返回值的说明 956 /// - Err(错误值类型): 错误的说明 957 /// 958 pub fn do_renameat2( 959 oldfd: i32, 960 filename_from: *const u8, 961 newfd: i32, 962 filename_to: *const u8, 963 _flags: u32, 964 ) -> Result<usize, SystemError> { 965 let filename_from = check_and_clone_cstr(filename_from, Some(MAX_PATHLEN)).unwrap(); 966 let filename_to = check_and_clone_cstr(filename_to, Some(MAX_PATHLEN)).unwrap(); 967 // 文件名过长 968 if filename_from.len() > MAX_PATHLEN || filename_to.len() > MAX_PATHLEN { 969 return Err(SystemError::ENAMETOOLONG); 970 } 971 972 //获取pcb，文件节点 973 let pcb = ProcessManager::current_pcb(); 974 let (_old_inode_begin, old_remain_path) = user_path_at(&pcb, oldfd, &filename_from)?; 975 let (_new_inode_begin, new_remain_path) = user_path_at(&pcb, newfd, &filename_to)?; 976 //获取父目录 977 let (old_filename, old_parent_path) = rsplit_path(&old_remain_path); 978 let old_parent_inode = ROOT_INODE() 979 .lookup_follow_symlink(old_parent_path.unwrap_or("/"), VFS_MAX_FOLLOW_SYMLINK_TIMES)?; 980 let (new_filename, new_parent_path) = rsplit_path(&new_remain_path); 981 let new_parent_inode = ROOT_INODE() 982 .lookup_follow_symlink(new_parent_path.unwrap_or("/"), VFS_MAX_FOLLOW_SYMLINK_TIMES)?; 983 old_parent_inode.move_to(old_filename, &new_parent_inode, new_filename)?; 984 return Ok(0); 985 } 986 987 /// @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 988 pub fn dup(oldfd: i32) -> Result<usize, SystemError> { 989 let binding = ProcessManager::current_pcb().fd_table(); 990 let mut fd_table_guard = binding.write(); 991 992 let old_file = fd_table_guard 993 .get_file_by_fd(oldfd) 994 .ok_or(SystemError::EBADF)?; 995 996 let new_file = old_file.try_clone().ok_or(SystemError::EBADF)?; 997 // dup默认非cloexec 998 new_file.set_close_on_exec(false); 999 // 申请文件描述符，并把文件对象存入其中 1000 let res = fd_table_guard.alloc_fd(new_file, None).map(|x| x as usize); 1001 return res; 1002 } 1003 1004 /// 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， 1005 /// 并返回新复制的文件结构体对应的fd. 1006 /// 如果新fd已经打开，则会先关闭新fd. 1007 /// 1008 /// ## 参数 1009 /// 1010 /// - `oldfd`：旧文件描述符 1011 /// - `newfd`：新文件描述符 1012 /// 1013 /// ## 返回值 1014 /// 1015 /// - 成功：新文件描述符 1016 /// - 失败：错误码 1017 pub fn dup2(oldfd: i32, newfd: i32) -> Result<usize, SystemError> { 1018 let binding = ProcessManager::current_pcb().fd_table(); 1019 let mut fd_table_guard = binding.write(); 1020 return Self::do_dup2(oldfd, newfd, &mut fd_table_guard); 1021 } 1022 1023 fn do_dup2( 1024 oldfd: i32, 1025 newfd: i32, 1026 fd_table_guard: &mut RwLockWriteGuard<'_, FileDescriptorVec>, 1027 ) -> Result<usize, SystemError> { 1028 Self::do_dup3(oldfd, newfd, FileMode::empty(), fd_table_guard) 1029 } 1030 1031 fn do_dup3( 1032 oldfd: i32, 1033 newfd: i32, 1034 flags: FileMode, 1035 fd_table_guard: &mut RwLockWriteGuard<'_, FileDescriptorVec>, 1036 ) -> Result<usize, SystemError> { 1037 // 确认oldfd, newid是否有效 1038 if !(FileDescriptorVec::validate_fd(oldfd) && FileDescriptorVec::validate_fd(newfd)) { 1039 return Err(SystemError::EBADF); 1040 } 1041 1042 if oldfd == newfd { 1043 // 若oldfd与newfd相等 1044 return Ok(newfd as usize); 1045 } 1046 let new_exists = fd_table_guard.get_file_by_fd(newfd).is_some(); 1047 if new_exists { 1048 // close newfd 1049 if fd_table_guard.drop_fd(newfd).is_err() { 1050 // An I/O error occurred while attempting to close fildes2. 1051 return Err(SystemError::EIO); 1052 } 1053 } 1054 1055 let old_file = fd_table_guard 1056 .get_file_by_fd(oldfd) 1057 .ok_or(SystemError::EBADF)?; 1058 let new_file = old_file.try_clone().ok_or(SystemError::EBADF)?; 1059 1060 if flags.contains(FileMode::O_CLOEXEC) { 1061 new_file.set_close_on_exec(true); 1062 } else { 1063 new_file.set_close_on_exec(false); 1064 } 1065 // 申请文件描述符，并把文件对象存入其中 1066 let res = fd_table_guard 1067 .alloc_fd(new_file, Some(newfd)) 1068 .map(|x| x as usize); 1069 return res; 1070 } 1071 1072 /// # fcntl 1073 /// 1074 /// ## 参数 1075 /// 1076 /// - `fd`：文件描述符 1077 /// - `cmd`：命令 1078 /// - `arg`：参数 1079 pub fn fcntl(fd: i32, cmd: FcntlCommand, arg: i32) -> Result<usize, SystemError> { 1080 // kdebug!("fcntl ({cmd:?}) fd: {fd}, arg={arg}"); 1081 match cmd { 1082 FcntlCommand::DupFd | FcntlCommand::DupFdCloexec => { 1083 if arg < 0 || arg as usize >= FileDescriptorVec::PROCESS_MAX_FD { 1084 return Err(SystemError::EBADF); 1085 } 1086 let arg = arg as usize; 1087 for i in arg..FileDescriptorVec::PROCESS_MAX_FD { 1088 let binding = ProcessManager::current_pcb().fd_table(); 1089 let mut fd_table_guard = binding.write(); 1090 if fd_table_guard.get_file_by_fd(i as i32).is_none() { 1091 if cmd == FcntlCommand::DupFd { 1092 return Self::do_dup2(fd, i as i32, &mut fd_table_guard); 1093 } else { 1094 return Self::do_dup3( 1095 fd, 1096 i as i32, 1097 FileMode::O_CLOEXEC, 1098 &mut fd_table_guard, 1099 ); 1100 } 1101 } 1102 } 1103 return Err(SystemError::EMFILE); 1104 } 1105 FcntlCommand::GetFd => { 1106 // Get file descriptor flags. 1107 let binding = ProcessManager::current_pcb().fd_table(); 1108 let fd_table_guard = binding.read(); 1109 1110 if let Some(file) = fd_table_guard.get_file_by_fd(fd) { 1111 // drop guard 以避免无法调度的问题 1112 drop(fd_table_guard); 1113 1114 if file.close_on_exec() { 1115 return Ok(FD_CLOEXEC as usize); 1116 } else { 1117 return Ok(0); 1118 } 1119 } 1120 return Err(SystemError::EBADF); 1121 } 1122 FcntlCommand::SetFd => { 1123 // Set file descriptor flags. 1124 let binding = ProcessManager::current_pcb().fd_table(); 1125 let fd_table_guard = binding.write(); 1126 1127 if let Some(file) = fd_table_guard.get_file_by_fd(fd) { 1128 // drop guard 以避免无法调度的问题 1129 drop(fd_table_guard); 1130 let arg = arg as u32; 1131 if arg & FD_CLOEXEC != 0 { 1132 file.set_close_on_exec(true); 1133 } else { 1134 file.set_close_on_exec(false); 1135 } 1136 return Ok(0); 1137 } 1138 return Err(SystemError::EBADF); 1139 } 1140 1141 FcntlCommand::GetFlags => { 1142 // Get file status flags. 1143 let binding = ProcessManager::current_pcb().fd_table(); 1144 let fd_table_guard = binding.read(); 1145 1146 if let Some(file) = fd_table_guard.get_file_by_fd(fd) { 1147 // drop guard 以避免无法调度的问题 1148 drop(fd_table_guard); 1149 return Ok(file.mode().bits() as usize); 1150 } 1151 1152 return Err(SystemError::EBADF); 1153 } 1154 FcntlCommand::SetFlags => { 1155 // Set file status flags. 1156 let binding = ProcessManager::current_pcb().fd_table(); 1157 let fd_table_guard = binding.write(); 1158 1159 if let Some(file) = fd_table_guard.get_file_by_fd(fd) { 1160 let arg = arg as u32; 1161 let mode = FileMode::from_bits(arg).ok_or(SystemError::EINVAL)?; 1162 // drop guard 以避免无法调度的问题 1163 drop(fd_table_guard); 1164 file.set_mode(mode)?; 1165 return Ok(0); 1166 } 1167 1168 return Err(SystemError::EBADF); 1169 } 1170 _ => { 1171 // TODO: unimplemented 1172 // 未实现的命令，返回0，不报错。 1173 1174 kwarn!("fcntl: unimplemented command: {:?}, defaults to 0.", cmd); 1175 return Err(SystemError::ENOSYS); 1176 } 1177 } 1178 } 1179 1180 /// # ftruncate 1181 /// 1182 /// ## 描述 1183 /// 1184 /// 改变文件大小. 1185 /// 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. 1186 /// 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. 1187 /// 1188 /// ## 参数 1189 /// 1190 /// - `fd`：文件描述符 1191 /// - `len`：文件大小 1192 /// 1193 /// ## 返回值 1194 /// 1195 /// 如果成功，返回0，否则返回错误码. 1196 pub fn ftruncate(fd: i32, len: usize) -> Result<usize, SystemError> { 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 let r = file.ftruncate(len).map(|_| 0); 1204 return r; 1205 } 1206 1207 return Err(SystemError::EBADF); 1208 } 1209 1210 fn do_fstat(fd: i32) -> Result<PosixKstat, SystemError> { 1211 let binding = ProcessManager::current_pcb().fd_table(); 1212 let fd_table_guard = binding.read(); 1213 let file = fd_table_guard 1214 .get_file_by_fd(fd) 1215 .ok_or(SystemError::EBADF)?; 1216 // drop guard 以避免无法调度的问题 1217 drop(fd_table_guard); 1218 1219 let mut kstat = PosixKstat::new(); 1220 // 获取文件信息 1221 let metadata = file.metadata()?; 1222 kstat.size = metadata.size; 1223 kstat.dev_id = metadata.dev_id as u64; 1224 kstat.inode = metadata.inode_id.into() as u64; 1225 kstat.blcok_size = metadata.blk_size as i64; 1226 kstat.blocks = metadata.blocks as u64; 1227 1228 kstat.atime.tv_sec = metadata.atime.tv_sec; 1229 kstat.atime.tv_nsec = metadata.atime.tv_nsec; 1230 kstat.mtime.tv_sec = metadata.mtime.tv_sec; 1231 kstat.mtime.tv_nsec = metadata.mtime.tv_nsec; 1232 kstat.ctime.tv_sec = metadata.ctime.tv_sec; 1233 kstat.ctime.tv_nsec = metadata.ctime.tv_nsec; 1234 1235 kstat.nlink = metadata.nlinks as u64; 1236 kstat.uid = metadata.uid as i32; 1237 kstat.gid = metadata.gid as i32; 1238 kstat.rdev = metadata.raw_dev.data() as i64; 1239 kstat.mode = metadata.mode; 1240 match file.file_type() { 1241 FileType::File => kstat.mode.insert(ModeType::S_IFREG), 1242 FileType::Dir => kstat.mode.insert(ModeType::S_IFDIR), 1243 FileType::BlockDevice => kstat.mode.insert(ModeType::S_IFBLK), 1244 FileType::CharDevice => kstat.mode.insert(ModeType::S_IFCHR), 1245 FileType::SymLink => kstat.mode.insert(ModeType::S_IFLNK), 1246 FileType::Socket => kstat.mode.insert(ModeType::S_IFSOCK), 1247 FileType::Pipe => kstat.mode.insert(ModeType::S_IFIFO), 1248 FileType::KvmDevice => kstat.mode.insert(ModeType::S_IFCHR), 1249 FileType::FramebufferDevice => kstat.mode.insert(ModeType::S_IFCHR), 1250 } 1251 1252 return Ok(kstat); 1253 } 1254 1255 pub fn fstat(fd: i32, usr_kstat: *mut PosixKstat) -> Result<usize, SystemError> { 1256 let mut writer = UserBufferWriter::new(usr_kstat, size_of::<PosixKstat>(), true)?; 1257 let kstat = Self::do_fstat(fd)?; 1258 1259 writer.copy_one_to_user(&kstat, 0)?; 1260 return Ok(0); 1261 } 1262 1263 pub fn stat(path: *const u8, user_kstat: *mut PosixKstat) -> Result<usize, SystemError> { 1264 let fd = Self::open( 1265 path, 1266 FileMode::O_RDONLY.bits(), 1267 ModeType::empty().bits(), 1268 true, 1269 )?; 1270 let r = Self::fstat(fd as i32, user_kstat); 1271 Self::close(fd).ok(); 1272 return r; 1273 } 1274 1275 pub fn lstat(path: *const u8, user_kstat: *mut PosixKstat) -> Result<usize, SystemError> { 1276 let fd = Self::open( 1277 path, 1278 FileMode::O_RDONLY.bits(), 1279 ModeType::empty().bits(), 1280 false, 1281 )?; 1282 let r = Self::fstat(fd as i32, user_kstat); 1283 Self::close(fd).ok(); 1284 return r; 1285 } 1286 1287 pub fn statfs(path: *const u8, user_statfs: *mut PosixStatfs) -> Result<usize, SystemError> { 1288 let mut writer = UserBufferWriter::new(user_statfs, size_of::<PosixStatfs>(), true)?; 1289 let fd = Self::open( 1290 path, 1291 FileMode::O_RDONLY.bits(), 1292 ModeType::empty().bits(), 1293 true, 1294 )?; 1295 let path = check_and_clone_cstr(path, Some(MAX_PATHLEN)).unwrap(); 1296 let pcb = ProcessManager::current_pcb(); 1297 let (_inode_begin, remain_path) = user_path_at(&pcb, fd as i32, &path)?; 1298 let inode = ROOT_INODE().lookup_follow_symlink(&remain_path, MAX_PATHLEN)?; 1299 let statfs = PosixStatfs::from(inode.fs().super_block()); 1300 writer.copy_one_to_user(&statfs, 0)?; 1301 return Ok(0); 1302 } 1303 1304 pub fn fstatfs(fd: i32, user_statfs: *mut PosixStatfs) -> Result<usize, SystemError> { 1305 let mut writer = UserBufferWriter::new(user_statfs, size_of::<PosixStatfs>(), true)?; 1306 let binding = ProcessManager::current_pcb().fd_table(); 1307 let fd_table_guard = binding.read(); 1308 let file = fd_table_guard 1309 .get_file_by_fd(fd) 1310 .ok_or(SystemError::EBADF)?; 1311 drop(fd_table_guard); 1312 let statfs = PosixStatfs::from(file.inode().fs().super_block()); 1313 writer.copy_one_to_user(&statfs, 0)?; 1314 return Ok(0); 1315 } 1316 1317 pub fn do_statx( 1318 fd: i32, 1319 path: *const u8, 1320 flags: u32, 1321 mask: u32, 1322 usr_kstat: *mut PosixStatx, 1323 ) -> Result<usize, SystemError> { 1324 if usr_kstat.is_null() { 1325 return Err(SystemError::EFAULT); 1326 } 1327 1328 let mask = PosixStatxMask::from_bits_truncate(mask); 1329 1330 if mask.contains(PosixStatxMask::STATX_RESERVED) { 1331 return Err(SystemError::ENAVAIL); 1332 } 1333 1334 let flags = FileMode::from_bits_truncate(flags); 1335 let ofd = Self::open(path, flags.bits(), ModeType::empty().bits, true)?; 1336 1337 let binding = ProcessManager::current_pcb().fd_table(); 1338 let fd_table_guard = binding.read(); 1339 let file = fd_table_guard 1340 .get_file_by_fd(ofd as i32) 1341 .ok_or(SystemError::EBADF)?; 1342 // drop guard 以避免无法调度的问题 1343 drop(fd_table_guard); 1344 let mut writer = UserBufferWriter::new(usr_kstat, size_of::<PosixStatx>(), true)?; 1345 let mut tmp: PosixStatx = PosixStatx::new(); 1346 // 获取文件信息 1347 let metadata = file.metadata()?; 1348 1349 tmp.stx_mask |= PosixStatxMask::STATX_BASIC_STATS; 1350 tmp.stx_blksize = metadata.blk_size as u32; 1351 if mask.contains(PosixStatxMask::STATX_MODE) || mask.contains(PosixStatxMask::STATX_TYPE) { 1352 tmp.stx_mode = metadata.mode; 1353 } 1354 if mask.contains(PosixStatxMask::STATX_NLINK) { 1355 tmp.stx_nlink = metadata.nlinks as u32; 1356 } 1357 if mask.contains(PosixStatxMask::STATX_UID) { 1358 tmp.stx_uid = metadata.uid as u32; 1359 } 1360 if mask.contains(PosixStatxMask::STATX_GID) { 1361 tmp.stx_gid = metadata.gid as u32; 1362 } 1363 if mask.contains(PosixStatxMask::STATX_ATIME) { 1364 tmp.stx_atime.tv_sec = metadata.atime.tv_sec; 1365 tmp.stx_atime.tv_nsec = metadata.atime.tv_nsec; 1366 } 1367 if mask.contains(PosixStatxMask::STATX_MTIME) { 1368 tmp.stx_mtime.tv_sec = metadata.ctime.tv_sec; 1369 tmp.stx_mtime.tv_nsec = metadata.ctime.tv_nsec; 1370 } 1371 if mask.contains(PosixStatxMask::STATX_CTIME) { 1372 // ctime是文件上次修改状态的时间 1373 tmp.stx_ctime.tv_sec = metadata.mtime.tv_sec; 1374 tmp.stx_ctime.tv_nsec = metadata.mtime.tv_nsec; 1375 } 1376 if mask.contains(PosixStatxMask::STATX_INO) { 1377 tmp.stx_inode = metadata.inode_id.into() as u64; 1378 } 1379 if mask.contains(PosixStatxMask::STATX_SIZE) { 1380 tmp.stx_size = metadata.size; 1381 } 1382 if mask.contains(PosixStatxMask::STATX_BLOCKS) { 1383 tmp.stx_blocks = metadata.blocks as u64; 1384 } 1385 1386 if mask.contains(PosixStatxMask::STATX_BTIME) { 1387 // btime是文件创建时间 1388 tmp.stx_btime.tv_sec = metadata.ctime.tv_sec; 1389 tmp.stx_btime.tv_nsec = metadata.ctime.tv_nsec; 1390 } 1391 if mask.contains(PosixStatxMask::STATX_ALL) { 1392 tmp.stx_attributes = StxAttributes::STATX_ATTR_APPEND; 1393 tmp.stx_attributes_mask |= 1394 StxAttributes::STATX_ATTR_AUTOMOUNT | StxAttributes::STATX_ATTR_DAX; 1395 tmp.stx_dev_major = metadata.dev_id as u32; 1396 tmp.stx_dev_minor = metadata.dev_id as u32; // 1397 tmp.stx_rdev_major = metadata.raw_dev.data(); 1398 tmp.stx_rdev_minor = metadata.raw_dev.data(); 1399 } 1400 if mask.contains(PosixStatxMask::STATX_MNT_ID) { 1401 tmp.stx_mnt_id = 0; 1402 } 1403 if mask.contains(PosixStatxMask::STATX_DIOALIGN) { 1404 tmp.stx_dio_mem_align = 0; 1405 tmp.stx_dio_offset_align = 0; 1406 } 1407 1408 match file.file_type() { 1409 FileType::File => tmp.stx_mode.insert(ModeType::S_IFREG), 1410 FileType::Dir => tmp.stx_mode.insert(ModeType::S_IFDIR), 1411 FileType::BlockDevice => tmp.stx_mode.insert(ModeType::S_IFBLK), 1412 FileType::CharDevice => tmp.stx_mode.insert(ModeType::S_IFCHR), 1413 FileType::SymLink => tmp.stx_mode.insert(ModeType::S_IFLNK), 1414 FileType::Socket => tmp.stx_mode.insert(ModeType::S_IFSOCK), 1415 FileType::Pipe => tmp.stx_mode.insert(ModeType::S_IFIFO), 1416 FileType::KvmDevice => tmp.stx_mode.insert(ModeType::S_IFCHR), 1417 FileType::FramebufferDevice => tmp.stx_mode.insert(ModeType::S_IFCHR), 1418 } 1419 1420 writer.copy_one_to_user(&tmp, 0)?; 1421 Self::close(fd as usize).ok(); 1422 return Ok(0); 1423 } 1424 1425 pub fn mknod( 1426 path: *const u8, 1427 mode: ModeType, 1428 dev_t: DeviceNumber, 1429 ) -> Result<usize, SystemError> { 1430 let path = check_and_clone_cstr(path, Some(MAX_PATHLEN))?; 1431 let path = path.as_str().trim(); 1432 1433 let inode: Result<Arc<dyn IndexNode>, SystemError> = 1434 ROOT_INODE().lookup_follow_symlink(path, VFS_MAX_FOLLOW_SYMLINK_TIMES); 1435 1436 if inode.is_ok() { 1437 return Err(SystemError::EEXIST); 1438 } 1439 1440 let (filename, parent_path) = rsplit_path(path); 1441 1442 // 查找父目录 1443 let parent_inode: Arc<dyn IndexNode> = ROOT_INODE() 1444 .lookup_follow_symlink(parent_path.unwrap_or("/"), VFS_MAX_FOLLOW_SYMLINK_TIMES)?; 1445 // 创建nod 1446 parent_inode.mknod(filename, mode, dev_t)?; 1447 1448 return Ok(0); 1449 } 1450 1451 pub fn writev(fd: i32, iov: usize, count: usize) -> Result<usize, SystemError> { 1452 // IoVecs会进行用户态检验 1453 let iovecs = unsafe { IoVecs::from_user(iov as *const IoVec, count, false) }?; 1454 1455 let data = iovecs.gather(); 1456 1457 Self::write(fd, &data) 1458 } 1459 1460 pub fn readv(fd: i32, iov: usize, count: usize) -> Result<usize, SystemError> { 1461 // IoVecs会进行用户态检验 1462 let mut iovecs = unsafe { IoVecs::from_user(iov as *const IoVec, count, true) }?; 1463 1464 let mut data = vec![0; iovecs.0.iter().map(|x| x.len()).sum()]; 1465 1466 let len = Self::read(fd, &mut data)?; 1467 1468 iovecs.scatter(&data[..len]); 1469 1470 return Ok(len); 1471 } 1472 1473 pub fn readlink_at( 1474 dirfd: i32, 1475 path: *const u8, 1476 user_buf: *mut u8, 1477 buf_size: usize, 1478 ) -> Result<usize, SystemError> { 1479 let path = check_and_clone_cstr(path, Some(MAX_PATHLEN))?; 1480 let path = path.as_str().trim(); 1481 let mut user_buf = UserBufferWriter::new(user_buf, buf_size, true)?; 1482 1483 let (inode, path) = user_path_at(&ProcessManager::current_pcb(), dirfd, path)?; 1484 1485 let inode = inode.lookup(path.as_str())?; 1486 if inode.metadata()?.file_type != FileType::SymLink { 1487 return Err(SystemError::EINVAL); 1488 } 1489 1490 let ubuf = user_buf.buffer::<u8>(0).unwrap(); 1491 1492 let file = File::new(inode, FileMode::O_RDONLY)?; 1493 1494 let len = file.read(buf_size, ubuf)?; 1495 1496 return Ok(len); 1497 } 1498 1499 pub fn readlink( 1500 path: *const u8, 1501 user_buf: *mut u8, 1502 buf_size: usize, 1503 ) -> Result<usize, SystemError> { 1504 return Self::readlink_at(AtFlags::AT_FDCWD.bits(), path, user_buf, buf_size); 1505 } 1506 1507 pub fn access(pathname: *const u8, mode: u32) -> Result<usize, SystemError> { 1508 return do_faccessat( 1509 AtFlags::AT_FDCWD.bits(), 1510 pathname, 1511 ModeType::from_bits(mode).ok_or(SystemError::EINVAL)?, 1512 0, 1513 ); 1514 } 1515 1516 pub fn faccessat2( 1517 dirfd: i32, 1518 pathname: *const u8, 1519 mode: u32, 1520 flags: u32, 1521 ) -> Result<usize, SystemError> { 1522 return do_faccessat( 1523 dirfd, 1524 pathname, 1525 ModeType::from_bits(mode).ok_or(SystemError::EINVAL)?, 1526 flags, 1527 ); 1528 } 1529 1530 pub fn chmod(pathname: *const u8, mode: u32) -> Result<usize, SystemError> { 1531 return do_fchmodat( 1532 AtFlags::AT_FDCWD.bits(), 1533 pathname, 1534 ModeType::from_bits(mode).ok_or(SystemError::EINVAL)?, 1535 ); 1536 } 1537 1538 pub fn fchmodat(dirfd: i32, pathname: *const u8, mode: u32) -> Result<usize, SystemError> { 1539 return do_fchmodat( 1540 dirfd, 1541 pathname, 1542 ModeType::from_bits(mode).ok_or(SystemError::EINVAL)?, 1543 ); 1544 } 1545 1546 pub fn fchmod(fd: i32, mode: u32) -> Result<usize, SystemError> { 1547 let _mode = ModeType::from_bits(mode).ok_or(SystemError::EINVAL)?; 1548 let binding = ProcessManager::current_pcb().fd_table(); 1549 let fd_table_guard = binding.read(); 1550 let _file = fd_table_guard 1551 .get_file_by_fd(fd) 1552 .ok_or(SystemError::EBADF)?; 1553 1554 // fchmod没完全实现，因此不修改文件的权限 1555 // todo: 实现fchmod 1556 kwarn!("fchmod not fully implemented"); 1557 return Ok(0); 1558 } 1559 /// #挂载文件系统 1560 /// 1561 /// 用于挂载文件系统,目前仅支持ramfs挂载 1562 /// 1563 /// ## 参数: 1564 /// 1565 /// - source 挂载设备(暂时不支持) 1566 /// - target 挂载目录 1567 /// - filesystemtype 文件系统 1568 /// - mountflags 挂载选项（暂未实现） 1569 /// - data 带数据挂载 1570 /// 1571 /// ## 返回值 1572 /// - Ok(0): 挂载成功 1573 /// - Err(SystemError) :挂载过程中出错 1574 pub fn mount( 1575 _source: *const u8, 1576 target: *const u8, 1577 filesystemtype: *const u8, 1578 _mountflags: usize, 1579 _data: *const c_void, 1580 ) -> Result<usize, SystemError> { 1581 let target = user_access::check_and_clone_cstr(target, Some(MAX_PATHLEN))?; 1582 1583 let filesystemtype = user_access::check_and_clone_cstr(filesystemtype, Some(MAX_PATHLEN))?; 1584 1585 let filesystemtype = producefs!(FSMAKER, filesystemtype)?; 1586 1587 Vcore::do_mount(filesystemtype, target.to_string().as_str())?; 1588 1589 return Ok(0); 1590 } 1591 1592 // 想法：可以在VFS中实现一个文件系统分发器，流程如下： 1593 // 1. 接受从上方传来的文件类型字符串 1594 // 2. 将传入值与启动时准备好的字符串数组逐个比较（probe） 1595 // 3. 直接在函数内调用构造方法并直接返回文件系统对象 1596 1597 /// src/linux/mount.c `umount` & `umount2` 1598 /// 1599 /// [umount(2) — Linux manual page](https://www.man7.org/linux/man-pages/man2/umount.2.html) 1600 pub fn umount2(target: *const u8, flags: i32) -> Result<(), SystemError> { 1601 let target = user_access::check_and_clone_cstr(target, Some(MAX_PATHLEN))?; 1602 Vcore::do_umount2( 1603 AtFlags::AT_FDCWD.bits(), 1604 &target, 1605 UmountFlag::from_bits(flags).ok_or(SystemError::EINVAL)?, 1606 )?; 1607 return Ok(()); 1608 } 1609 } 1610 1611 #[repr(C)] 1612 #[derive(Debug, Clone, Copy)] 1613 pub struct IoVec { 1614 /// 缓冲区的起始地址 1615 pub iov_base: *mut u8, 1616 /// 缓冲区的长度 1617 pub iov_len: usize, 1618 } 1619 1620 /// 用于存储多个来自用户空间的IoVec 1621 /// 1622 /// 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。 1623 /// TODO：支持分散读写 1624 #[derive(Debug)] 1625 pub struct IoVecs(Vec<&'static mut [u8]>); 1626 1627 impl IoVecs { 1628 /// 从用户空间的IoVec中构造IoVecs 1629 /// 1630 /// @param iov 用户空间的IoVec 1631 /// @param iovcnt 用户空间的IoVec的数量 1632 /// @param readv 是否为readv系统调用 1633 /// 1634 /// @return 构造成功返回IoVecs，否则返回错误码 1635 pub unsafe fn from_user( 1636 iov: *const IoVec, 1637 iovcnt: usize, 1638 _readv: bool, 1639 ) -> Result<Self, SystemError> { 1640 // 检查iov指针所在空间是否合法 1641 verify_area( 1642 VirtAddr::new(iov as usize), 1643 iovcnt * core::mem::size_of::<IoVec>(), 1644 ) 1645 .map_err(|_| SystemError::EFAULT)?; 1646 1647 // 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） 1648 let iovs: &[IoVec] = core::slice::from_raw_parts(iov, iovcnt); 1649 1650 let mut slices: Vec<&mut [u8]> = vec![]; 1651 slices.reserve(iovs.len()); 1652 1653 for iov in iovs.iter() { 1654 if iov.iov_len == 0 { 1655 continue; 1656 } 1657 1658 verify_area( 1659 VirtAddr::new(iov.iov_base as usize), 1660 iovcnt * core::mem::size_of::<IoVec>(), 1661 ) 1662 .map_err(|_| SystemError::EFAULT)?; 1663 1664 slices.push(core::slice::from_raw_parts_mut(iov.iov_base, iov.iov_len)); 1665 } 1666 1667 return Ok(Self(slices)); 1668 } 1669 1670 /// @brief 将IoVecs中的数据聚合到一个缓冲区中 1671 /// 1672 /// @return 返回聚合后的缓冲区 1673 pub fn gather(&self) -> Vec<u8> { 1674 let mut buf = Vec::new(); 1675 for slice in self.0.iter() { 1676 buf.extend_from_slice(slice); 1677 } 1678 return buf; 1679 } 1680 1681 /// @brief 将给定的数据分散写入到IoVecs中 1682 pub fn scatter(&mut self, data: &[u8]) { 1683 let mut data: &[u8] = data; 1684 for slice in self.0.iter_mut() { 1685 let len = core::cmp::min(slice.len(), data.len()); 1686 if len == 0 { 1687 continue; 1688 } 1689 1690 slice[..len].copy_from_slice(&data[..len]); 1691 data = &data[len..]; 1692 } 1693 } 1694 1695 /// @brief 创建与IoVecs等长的缓冲区 1696 /// 1697 /// @param set_len 是否设置返回的Vec的len。 1698 /// 如果为true，则返回的Vec的len为所有IoVec的长度之和; 1699 /// 否则返回的Vec的len为0，capacity为所有IoVec的长度之和. 1700 /// 1701 /// @return 返回创建的缓冲区 1702 pub fn new_buf(&self, set_len: bool) -> Vec<u8> { 1703 let total_len: usize = self.0.iter().map(|slice| slice.len()).sum(); 1704 let mut buf: Vec<u8> = Vec::with_capacity(total_len); 1705 1706 if set_len { 1707 buf.resize(total_len, 0); 1708 } 1709 return buf; 1710 } 1711 } 1712