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