1 use crate::filesystem::overlayfs::OverlayMountData; 2 use crate::filesystem::vfs::FileSystemMakerData; 3 use core::mem::size_of; 4 5 use alloc::{string::String, sync::Arc, vec::Vec}; 6 use log::warn; 7 use system_error::SystemError; 8 9 use crate::producefs; 10 use crate::syscall::user_access::UserBufferReader; 11 use crate::{ 12 driver::base::{block::SeekFrom, device::device_number::DeviceNumber}, 13 filesystem::vfs::{core as Vcore, file::FileDescriptorVec}, 14 libs::rwlock::RwLockWriteGuard, 15 mm::{verify_area, VirtAddr}, 16 process::ProcessManager, 17 syscall::{ 18 user_access::{self, check_and_clone_cstr, UserBufferWriter}, 19 Syscall, 20 }, 21 time::{syscall::PosixTimeval, PosixTimeSpec}, 22 }; 23 24 use super::core::do_symlinkat; 25 use super::{ 26 core::{do_mkdir_at, do_remove_dir, do_unlink_at}, 27 fcntl::{AtFlags, FcntlCommand, FD_CLOEXEC}, 28 file::{File, FileMode}, 29 open::{ 30 do_faccessat, do_fchmodat, do_fchownat, do_sys_open, do_utimensat, do_utimes, ksys_fchown, 31 }, 32 utils::{rsplit_path, user_path_at}, 33 Dirent, FileType, IndexNode, SuperBlock, FSMAKER, MAX_PATHLEN, ROOT_INODE, 34 VFS_MAX_FOLLOW_SYMLINK_TIMES, 35 }; 36 37 pub const SEEK_SET: u32 = 0; 38 pub const SEEK_CUR: u32 = 1; 39 pub const SEEK_END: u32 = 2; 40 pub const SEEK_MAX: u32 = 3; 41 42 bitflags! { 43 /// 文件类型和权限 44 #[repr(C)] 45 pub struct ModeType: u32 { 46 /// 掩码 47 const S_IFMT = 0o0_170_000; 48 /// 文件类型 49 const S_IFSOCK = 0o140000; 50 const S_IFLNK = 0o120000; 51 const S_IFREG = 0o100000; 52 const S_IFBLK = 0o060000; 53 const S_IFDIR = 0o040000; 54 const S_IFCHR = 0o020000; 55 const S_IFIFO = 0o010000; 56 57 const S_ISUID = 0o004000; 58 const S_ISGID = 0o002000; 59 const S_ISVTX = 0o001000; 60 /// 文件用户权限 61 const S_IRWXU = 0o0700; 62 const S_IRUSR = 0o0400; 63 const S_IWUSR = 0o0200; 64 const S_IXUSR = 0o0100; 65 /// 文件组权限 66 const S_IRWXG = 0o0070; 67 const S_IRGRP = 0o0040; 68 const S_IWGRP = 0o0020; 69 const S_IXGRP = 0o0010; 70 /// 文件其他用户权限 71 const S_IRWXO = 0o0007; 72 const S_IROTH = 0o0004; 73 const S_IWOTH = 0o0002; 74 const S_IXOTH = 0o0001; 75 76 /// 0o777 77 const S_IRWXUGO = Self::S_IRWXU.bits | Self::S_IRWXG.bits | Self::S_IRWXO.bits; 78 /// 0o7777 79 const S_IALLUGO = Self::S_ISUID.bits | Self::S_ISGID.bits | Self::S_ISVTX.bits| Self::S_IRWXUGO.bits; 80 /// 0o444 81 const S_IRUGO = Self::S_IRUSR.bits | Self::S_IRGRP.bits | Self::S_IROTH.bits; 82 /// 0o222 83 const S_IWUGO = Self::S_IWUSR.bits | Self::S_IWGRP.bits | Self::S_IWOTH.bits; 84 /// 0o111 85 const S_IXUGO = Self::S_IXUSR.bits | Self::S_IXGRP.bits | Self::S_IXOTH.bits; 86 87 88 } 89 } 90 91 #[repr(C)] 92 #[derive(Clone, Copy)] 93 /// # 文件信息结构体 94 pub struct PosixKstat { 95 /// 硬件设备ID 96 dev_id: u64, 97 /// inode号 98 inode: u64, 99 /// 硬链接数 100 nlink: u64, 101 /// 文件权限 102 mode: ModeType, 103 /// 所有者用户ID 104 uid: i32, 105 /// 所有者组ID 106 gid: i32, 107 /// 设备ID 108 rdev: i64, 109 /// 文件大小 110 size: i64, 111 /// 文件系统块大小 112 blcok_size: i64, 113 /// 分配的512B块数 114 blocks: u64, 115 /// 最后访问时间 116 atime: PosixTimeSpec, 117 /// 最后修改时间 118 mtime: PosixTimeSpec, 119 /// 最后状态变化时间 120 ctime: PosixTimeSpec, 121 /// 用于填充结构体大小的空白数据 122 pub _pad: [i8; 24], 123 } 124 impl PosixKstat { new() -> Self125 fn new() -> Self { 126 Self { 127 inode: 0, 128 dev_id: 0, 129 mode: ModeType { bits: 0 }, 130 nlink: 0, 131 uid: 0, 132 gid: 0, 133 rdev: 0, 134 size: 0, 135 atime: PosixTimeSpec { 136 tv_sec: 0, 137 tv_nsec: 0, 138 }, 139 mtime: PosixTimeSpec { 140 tv_sec: 0, 141 tv_nsec: 0, 142 }, 143 ctime: PosixTimeSpec { 144 tv_sec: 0, 145 tv_nsec: 0, 146 }, 147 blcok_size: 0, 148 blocks: 0, 149 _pad: Default::default(), 150 } 151 } 152 } 153 154 #[repr(C)] 155 #[derive(Clone, Copy)] 156 /// # 文件信息结构体X 157 pub struct PosixStatx { 158 /* 0x00 */ 159 stx_mask: PosixStatxMask, 160 /// 文件系统块大小 161 stx_blksize: u32, 162 /// Flags conveying information about the file [uncond] 163 stx_attributes: StxAttributes, 164 /* 0x10 */ 165 /// 硬链接数 166 stx_nlink: u32, 167 /// 所有者用户ID 168 stx_uid: u32, 169 /// 所有者组ID 170 stx_gid: u32, 171 /// 文件权限 172 stx_mode: ModeType, 173 174 /* 0x20 */ 175 /// inode号 176 stx_inode: u64, 177 /// 文件大小 178 stx_size: i64, 179 /// 分配的512B块数 180 stx_blocks: u64, 181 /// Mask to show what's supported in stx_attributes 182 stx_attributes_mask: StxAttributes, 183 184 /* 0x40 */ 185 /// 最后访问时间 186 stx_atime: PosixTimeSpec, 187 /// 文件创建时间 188 stx_btime: PosixTimeSpec, 189 /// 最后状态变化时间 190 stx_ctime: PosixTimeSpec, 191 /// 最后修改时间 192 stx_mtime: PosixTimeSpec, 193 194 /* 0x80 */ 195 /// 主设备ID 196 stx_rdev_major: u32, 197 /// 次设备ID 198 stx_rdev_minor: u32, 199 /// 主硬件设备ID 200 stx_dev_major: u32, 201 /// 次硬件设备ID 202 stx_dev_minor: u32, 203 204 /* 0x90 */ 205 stx_mnt_id: u64, 206 stx_dio_mem_align: u32, 207 stx_dio_offset_align: u32, 208 } 209 impl PosixStatx { new() -> Self210 fn new() -> Self { 211 Self { 212 stx_mask: PosixStatxMask::STATX_BASIC_STATS, 213 stx_blksize: 0, 214 stx_attributes: StxAttributes::STATX_ATTR_APPEND, 215 stx_nlink: 0, 216 stx_uid: 0, 217 stx_gid: 0, 218 stx_mode: ModeType { bits: 0 }, 219 stx_inode: 0, 220 stx_size: 0, 221 stx_blocks: 0, 222 stx_attributes_mask: StxAttributes::STATX_ATTR_APPEND, 223 stx_atime: PosixTimeSpec { 224 tv_sec: 0, 225 tv_nsec: 0, 226 }, 227 stx_btime: PosixTimeSpec { 228 tv_sec: 0, 229 tv_nsec: 0, 230 }, 231 stx_ctime: PosixTimeSpec { 232 tv_sec: 0, 233 tv_nsec: 0, 234 }, 235 stx_mtime: PosixTimeSpec { 236 tv_sec: 0, 237 tv_nsec: 0, 238 }, 239 stx_rdev_major: 0, 240 stx_rdev_minor: 0, 241 stx_dev_major: 0, 242 stx_dev_minor: 0, 243 stx_mnt_id: 0, 244 stx_dio_mem_align: 0, 245 stx_dio_offset_align: 0, 246 } 247 } 248 } 249 250 bitflags! { 251 pub struct PosixStatxMask: u32{ 252 /// Want stx_mode & S_IFMT 253 const STATX_TYPE = 0x00000001; 254 255 /// Want stx_mode & ~S_IFMT 256 const STATX_MODE = 0x00000002; 257 258 /// Want stx_nlink 259 const STATX_NLINK = 0x00000004; 260 261 /// Want stx_uid 262 const STATX_UID = 0x00000008; 263 264 /// Want stx_gid 265 const STATX_GID = 0x00000010; 266 267 /// Want stx_atime 268 const STATX_ATIME = 0x00000020; 269 270 /// Want stx_mtime 271 const STATX_MTIME = 0x00000040; 272 273 /// Want stx_ctime 274 const STATX_CTIME = 0x00000080; 275 276 /// Want stx_ino 277 const STATX_INO = 0x00000100; 278 279 /// Want stx_size 280 const STATX_SIZE = 0x00000200; 281 282 /// Want stx_blocks 283 const STATX_BLOCKS = 0x00000400; 284 285 /// [All of the above] 286 const STATX_BASIC_STATS = 0x000007ff; 287 288 /// Want stx_btime 289 const STATX_BTIME = 0x00000800; 290 291 /// The same as STATX_BASIC_STATS | STATX_BTIME. 292 /// It is deprecated and should not be used. 293 const STATX_ALL = 0x00000fff; 294 295 /// Want stx_mnt_id (since Linux 5.8) 296 const STATX_MNT_ID = 0x00001000; 297 298 /// Want stx_dio_mem_align and stx_dio_offset_align 299 /// (since Linux 6.1; support varies by filesystem) 300 const STATX_DIOALIGN = 0x00002000; 301 302 /// Reserved for future struct statx expansion 303 const STATX_RESERVED = 0x80000000; 304 } 305 } 306 307 bitflags! { 308 pub struct StxAttributes: u64 { 309 /// 文件被文件系统压缩 310 const STATX_ATTR_COMPRESSED = 0x00000004; 311 /// 文件被标记为不可修改 312 const STATX_ATTR_IMMUTABLE = 0x00000010; 313 /// 文件是只追加写入的 314 const STATX_ATTR_APPEND = 0x00000020; 315 /// 文件不会被备份 316 const STATX_ATTR_NODUMP = 0x00000040; 317 /// 文件需要密钥才能在文件系统中解密 318 const STATX_ATTR_ENCRYPTED = 0x00000800; 319 /// 目录是自动挂载触发器 320 const STATX_ATTR_AUTOMOUNT = 0x00001000; 321 /// 目录是挂载点的根目录 322 const STATX_ATTR_MOUNT_ROOT = 0x00002000; 323 /// 文件受到 Verity 保护 324 const STATX_ATTR_VERITY = 0x00100000; 325 /// 文件当前处于 DAX 状态 CPU直接访问 326 const STATX_ATTR_DAX = 0x00200000; 327 } 328 } 329 330 bitflags! { 331 pub struct UtimensFlags: u32 { 332 /// 不需要解释符号链接 333 const AT_SYMLINK_NOFOLLOW = 0x100; 334 } 335 } 336 337 #[repr(C)] 338 #[derive(Debug, Clone, Copy)] 339 pub struct PosixStatfs { 340 f_type: u64, 341 f_bsize: u64, 342 f_blocks: u64, 343 f_bfree: u64, 344 f_bavail: u64, 345 f_files: u64, 346 f_ffree: u64, 347 f_fsid: u64, 348 f_namelen: u64, 349 f_frsize: u64, 350 f_flags: u64, 351 f_spare: [u64; 4], 352 } 353 354 impl From<SuperBlock> for PosixStatfs { from(super_block: SuperBlock) -> Self355 fn from(super_block: SuperBlock) -> Self { 356 Self { 357 f_type: super_block.magic.bits, 358 f_bsize: super_block.bsize, 359 f_blocks: super_block.blocks, 360 f_bfree: super_block.bfree, 361 f_bavail: super_block.bavail, 362 f_files: super_block.files, 363 f_ffree: super_block.ffree, 364 f_fsid: super_block.fsid, 365 f_namelen: super_block.namelen, 366 f_frsize: super_block.frsize, 367 f_flags: super_block.flags, 368 f_spare: [0u64; 4], 369 } 370 } 371 } 372 /// 373 /// Arguments for how openat2(2) should open the target path. If only @flags and 374 /// @mode are non-zero, then openat2(2) operates very similarly to openat(2). 375 /// 376 /// However, unlike openat(2), unknown or invalid bits in @flags result in 377 /// -EINVAL rather than being silently ignored. @mode must be zero unless one of 378 /// {O_CREAT, O_TMPFILE} are set. 379 /// 380 /// ## 成员变量 381 /// 382 /// - flags: O_* flags. 383 /// - mode: O_CREAT/O_TMPFILE file mode. 384 /// - resolve: RESOLVE_* flags. 385 #[derive(Debug, Clone, Copy)] 386 #[repr(C)] 387 pub struct PosixOpenHow { 388 pub flags: u64, 389 pub mode: u64, 390 pub resolve: u64, 391 } 392 393 impl PosixOpenHow { 394 #[allow(dead_code)] new(flags: u64, mode: u64, resolve: u64) -> Self395 pub fn new(flags: u64, mode: u64, resolve: u64) -> Self { 396 Self { 397 flags, 398 mode, 399 resolve, 400 } 401 } 402 } 403 404 #[allow(dead_code)] 405 #[derive(Debug, Clone, Copy)] 406 pub struct OpenHow { 407 pub o_flags: FileMode, 408 pub mode: ModeType, 409 pub resolve: OpenHowResolve, 410 } 411 412 impl OpenHow { new(mut o_flags: FileMode, mut mode: ModeType, resolve: OpenHowResolve) -> Self413 pub fn new(mut o_flags: FileMode, mut mode: ModeType, resolve: OpenHowResolve) -> Self { 414 if !o_flags.contains(FileMode::O_CREAT) { 415 mode = ModeType::empty(); 416 } 417 418 if o_flags.contains(FileMode::O_PATH) { 419 o_flags = o_flags.intersection(FileMode::O_PATH_FLAGS); 420 } 421 422 Self { 423 o_flags, 424 mode, 425 resolve, 426 } 427 } 428 } 429 430 impl From<PosixOpenHow> for OpenHow { from(posix_open_how: PosixOpenHow) -> Self431 fn from(posix_open_how: PosixOpenHow) -> Self { 432 let o_flags = FileMode::from_bits_truncate(posix_open_how.flags as u32); 433 let mode = ModeType::from_bits_truncate(posix_open_how.mode as u32); 434 let resolve = OpenHowResolve::from_bits_truncate(posix_open_how.resolve); 435 return Self::new(o_flags, mode, resolve); 436 } 437 } 438 439 bitflags! { 440 pub struct OpenHowResolve: u64{ 441 /// Block mount-point crossings 442 /// (including bind-mounts). 443 const RESOLVE_NO_XDEV = 0x01; 444 445 /// Block traversal through procfs-style 446 /// "magic-links" 447 const RESOLVE_NO_MAGICLINKS = 0x02; 448 449 /// Block traversal through all symlinks 450 /// (implies OEXT_NO_MAGICLINKS) 451 const RESOLVE_NO_SYMLINKS = 0x04; 452 /// Block "lexical" trickery like 453 /// "..", symlinks, and absolute 454 const RESOLVE_BENEATH = 0x08; 455 /// Make all jumps to "/" and ".." 456 /// be scoped inside the dirfd 457 /// (similar to chroot(2)). 458 const RESOLVE_IN_ROOT = 0x10; 459 // Only complete if resolution can be 460 // completed through cached lookup. May 461 // return -EAGAIN if that's not 462 // possible. 463 const RESOLVE_CACHED = 0x20; 464 } 465 } 466 467 bitflags! { 468 pub struct UmountFlag: i32 { 469 const DEFAULT = 0; /* Default call to umount. */ 470 const MNT_FORCE = 1; /* Force unmounting. */ 471 const MNT_DETACH = 2; /* Just detach from the tree. */ 472 const MNT_EXPIRE = 4; /* Mark for expiry. */ 473 const UMOUNT_NOFOLLOW = 8; /* Don't follow symlink on umount. */ 474 } 475 } 476 477 impl Syscall { 478 /// @brief 为当前进程打开一个文件 479 /// 480 /// @param path 文件路径 481 /// @param o_flags 打开文件的标志位 482 /// 483 /// @return 文件描述符编号，或者是错误码 open( path: *const u8, o_flags: u32, mode: u32, follow_symlink: bool, ) -> Result<usize, SystemError>484 pub fn open( 485 path: *const u8, 486 o_flags: u32, 487 mode: u32, 488 follow_symlink: bool, 489 ) -> Result<usize, SystemError> { 490 let path = check_and_clone_cstr(path, Some(MAX_PATHLEN))? 491 .into_string() 492 .map_err(|_| SystemError::EINVAL)?; 493 494 let open_flags: FileMode = FileMode::from_bits(o_flags).ok_or(SystemError::EINVAL)?; 495 let mode = ModeType::from_bits(mode).ok_or(SystemError::EINVAL)?; 496 return do_sys_open( 497 AtFlags::AT_FDCWD.bits(), 498 &path, 499 open_flags, 500 mode, 501 follow_symlink, 502 ); 503 } 504 openat( dirfd: i32, path: *const u8, o_flags: u32, mode: u32, follow_symlink: bool, ) -> Result<usize, SystemError>505 pub fn openat( 506 dirfd: i32, 507 path: *const u8, 508 o_flags: u32, 509 mode: u32, 510 follow_symlink: bool, 511 ) -> Result<usize, SystemError> { 512 let path = check_and_clone_cstr(path, Some(MAX_PATHLEN))? 513 .into_string() 514 .map_err(|_| SystemError::EINVAL)?; 515 516 let open_flags: FileMode = FileMode::from_bits(o_flags).ok_or(SystemError::EINVAL)?; 517 let mode = ModeType::from_bits(mode).ok_or(SystemError::EINVAL)?; 518 return do_sys_open(dirfd, &path, open_flags, mode, follow_symlink); 519 } 520 521 /// @brief 关闭文件 522 /// 523 /// @param fd 文件描述符编号 524 /// 525 /// @return 成功返回0，失败返回错误码 close(fd: usize) -> Result<usize, SystemError>526 pub fn close(fd: usize) -> Result<usize, SystemError> { 527 let binding = ProcessManager::current_pcb().fd_table(); 528 let mut fd_table_guard = binding.write(); 529 let _file = fd_table_guard.drop_fd(fd as i32)?; 530 drop(fd_table_guard); 531 Ok(0) 532 } 533 534 /// @brief 发送命令到文件描述符对应的设备， 535 /// 536 /// @param fd 文件描述符编号 537 /// @param cmd 设备相关的请求类型 538 /// 539 /// @return Ok(usize) 成功返回0 540 /// @return Err(SystemError) 读取失败，返回posix错误码 ioctl(fd: usize, cmd: u32, data: usize) -> Result<usize, SystemError>541 pub fn ioctl(fd: usize, cmd: u32, data: usize) -> Result<usize, SystemError> { 542 let binding = ProcessManager::current_pcb().fd_table(); 543 let fd_table_guard = binding.read(); 544 545 let file = fd_table_guard 546 .get_file_by_fd(fd as i32) 547 .ok_or(SystemError::EBADF)?; 548 549 // drop guard 以避免无法调度的问题 550 drop(fd_table_guard); 551 let r = file.inode().ioctl(cmd, data, &file.private_data.lock()); 552 return r; 553 } 554 555 /// @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。 556 /// 557 /// @param fd 文件描述符编号 558 /// @param buf 输出缓冲区 559 /// 560 /// @return Ok(usize) 成功读取的数据的字节数 561 /// @return Err(SystemError) 读取失败，返回posix错误码 read(fd: i32, buf: &mut [u8]) -> Result<usize, SystemError>562 pub fn read(fd: i32, buf: &mut [u8]) -> Result<usize, SystemError> { 563 let binding = ProcessManager::current_pcb().fd_table(); 564 let fd_table_guard = binding.read(); 565 566 let file = fd_table_guard.get_file_by_fd(fd); 567 if file.is_none() { 568 return Err(SystemError::EBADF); 569 } 570 // drop guard 以避免无法调度的问题 571 drop(fd_table_guard); 572 let file = file.unwrap(); 573 574 return file.read(buf.len(), buf); 575 } 576 577 /// @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。 578 /// 579 /// @param fd 文件描述符编号 580 /// @param buf 输入缓冲区 581 /// 582 /// @return Ok(usize) 成功写入的数据的字节数 583 /// @return Err(SystemError) 写入失败，返回posix错误码 write(fd: i32, buf: &[u8]) -> Result<usize, SystemError>584 pub fn write(fd: i32, buf: &[u8]) -> Result<usize, SystemError> { 585 let binding = ProcessManager::current_pcb().fd_table(); 586 let fd_table_guard = binding.read(); 587 588 let file = fd_table_guard 589 .get_file_by_fd(fd) 590 .ok_or(SystemError::EBADF)?; 591 592 // drop guard 以避免无法调度的问题 593 drop(fd_table_guard); 594 return file.write(buf.len(), buf); 595 } 596 597 /// @brief 调整文件操作指针的位置 598 /// 599 /// @param fd 文件描述符编号 600 /// @param seek 调整的方式 601 /// 602 /// @return Ok(usize) 调整后，文件访问指针相对于文件头部的偏移量 603 /// @return Err(SystemError) 调整失败，返回posix错误码 lseek(fd: i32, offset: i64, seek: u32) -> Result<usize, SystemError>604 pub fn lseek(fd: i32, offset: i64, seek: u32) -> Result<usize, SystemError> { 605 let seek = match seek { 606 SEEK_SET => Ok(SeekFrom::SeekSet(offset)), 607 SEEK_CUR => Ok(SeekFrom::SeekCurrent(offset)), 608 SEEK_END => Ok(SeekFrom::SeekEnd(offset)), 609 SEEK_MAX => Ok(SeekFrom::SeekEnd(0)), 610 _ => Err(SystemError::EINVAL), 611 }?; 612 613 let binding = ProcessManager::current_pcb().fd_table(); 614 let fd_table_guard = binding.read(); 615 let file = fd_table_guard 616 .get_file_by_fd(fd) 617 .ok_or(SystemError::EBADF)?; 618 619 // drop guard 以避免无法调度的问题 620 drop(fd_table_guard); 621 return file.lseek(seek); 622 } 623 624 /// # sys_pread64 系统调用的实际执行函数 625 /// 626 /// ## 参数 627 /// - `fd`: 文件描述符 628 /// - `buf`: 读出缓冲区 629 /// - `len`: 要读取的字节数 630 /// - `offset`: 文件偏移量 pread(fd: i32, buf: &mut [u8], len: usize, offset: usize) -> Result<usize, SystemError>631 pub fn pread(fd: i32, buf: &mut [u8], len: usize, offset: usize) -> Result<usize, SystemError> { 632 let binding = ProcessManager::current_pcb().fd_table(); 633 let fd_table_guard = binding.read(); 634 635 let file = fd_table_guard.get_file_by_fd(fd); 636 if file.is_none() { 637 return Err(SystemError::EBADF); 638 } 639 // drop guard 以避免无法调度的问题 640 drop(fd_table_guard); 641 let file = file.unwrap(); 642 643 return file.pread(offset, len, buf); 644 } 645 646 /// # sys_pwrite64 系统调用的实际执行函数 647 /// 648 /// ## 参数 649 /// - `fd`: 文件描述符 650 /// - `buf`: 写入缓冲区 651 /// - `len`: 要写入的字节数 652 /// - `offset`: 文件偏移量 pwrite(fd: i32, buf: &[u8], len: usize, offset: usize) -> Result<usize, SystemError>653 pub fn pwrite(fd: i32, buf: &[u8], len: usize, offset: usize) -> Result<usize, SystemError> { 654 let binding = ProcessManager::current_pcb().fd_table(); 655 let fd_table_guard = binding.read(); 656 657 let file = fd_table_guard.get_file_by_fd(fd); 658 if file.is_none() { 659 return Err(SystemError::EBADF); 660 } 661 // drop guard 以避免无法调度的问题 662 drop(fd_table_guard); 663 let file = file.unwrap(); 664 665 return file.pwrite(offset, len, buf); 666 } 667 668 /// @brief 切换工作目录 669 /// 670 /// @param dest_path 目标路径 671 /// 672 /// @return 返回码 描述 673 /// 0 | 成功 674 /// 675 /// EACCESS | 权限不足 676 /// 677 /// ELOOP | 解析path时遇到路径循环 678 /// 679 /// ENAMETOOLONG | 路径名过长 680 /// 681 /// ENOENT | 目标文件或目录不存在 682 /// 683 /// ENODIR | 检索期间发现非目录项 684 /// 685 /// ENOMEM | 系统内存不足 686 /// 687 /// EFAULT | 错误的地址 688 /// 689 /// ENAMETOOLONG | 路径过长 chdir(path: *const u8) -> Result<usize, SystemError>690 pub fn chdir(path: *const u8) -> Result<usize, SystemError> { 691 if path.is_null() { 692 return Err(SystemError::EFAULT); 693 } 694 695 let path = check_and_clone_cstr(path, Some(MAX_PATHLEN))? 696 .into_string() 697 .map_err(|_| SystemError::EINVAL)?; 698 699 let proc = ProcessManager::current_pcb(); 700 // Copy path to kernel space to avoid some security issues 701 let mut new_path = String::from(""); 702 if !path.is_empty() { 703 let cwd = match path.as_bytes()[0] { 704 b'/' => String::from("/"), 705 _ => proc.basic().cwd(), 706 }; 707 let mut cwd_vec: Vec<_> = cwd.split('/').filter(|&x| !x.is_empty()).collect(); 708 let path_split = path.split('/').filter(|&x| !x.is_empty()); 709 for seg in path_split { 710 if seg == ".." { 711 cwd_vec.pop(); 712 } else if seg == "." { 713 // 当前目录 714 } else { 715 cwd_vec.push(seg); 716 } 717 } 718 //proc.basic().set_path(String::from("")); 719 for seg in cwd_vec { 720 new_path.push('/'); 721 new_path.push_str(seg); 722 } 723 if new_path.is_empty() { 724 new_path = String::from("/"); 725 } 726 } 727 let inode = 728 match ROOT_INODE().lookup_follow_symlink(&new_path, VFS_MAX_FOLLOW_SYMLINK_TIMES) { 729 Err(_) => { 730 return Err(SystemError::ENOENT); 731 } 732 Ok(i) => i, 733 }; 734 let metadata = inode.metadata()?; 735 if metadata.file_type == FileType::Dir { 736 proc.basic_mut().set_cwd(new_path); 737 return Ok(0); 738 } else { 739 return Err(SystemError::ENOTDIR); 740 } 741 } 742 743 /// @brief 获取当前进程的工作目录路径 744 /// 745 /// @param buf 指向缓冲区的指针 746 /// @param size 缓冲区的大小 747 /// 748 /// @return 成功，返回的指针指向包含工作目录路径的字符串 749 /// @return 错误，没有足够的空间 getcwd(buf: &mut [u8]) -> Result<VirtAddr, SystemError>750 pub fn getcwd(buf: &mut [u8]) -> Result<VirtAddr, SystemError> { 751 let proc = ProcessManager::current_pcb(); 752 let cwd = proc.basic().cwd(); 753 754 let cwd_bytes = cwd.as_bytes(); 755 let cwd_len = cwd_bytes.len(); 756 if cwd_len + 1 > buf.len() { 757 return Err(SystemError::ENOMEM); 758 } 759 buf[..cwd_len].copy_from_slice(cwd_bytes); 760 buf[cwd_len] = 0; 761 762 return Ok(VirtAddr::new(buf.as_ptr() as usize)); 763 } 764 765 /// @brief 获取目录中的数据 766 /// 767 /// TODO: 这个函数的语义与Linux不一致，需要修改！！！ 768 /// 769 /// @param fd 文件描述符号 770 /// @param buf 输出缓冲区 771 /// 772 /// @return 成功返回读取的字节数，失败返回错误码 getdents(fd: i32, buf: &mut [u8]) -> Result<usize, SystemError>773 pub fn getdents(fd: i32, buf: &mut [u8]) -> Result<usize, SystemError> { 774 let dirent = 775 unsafe { (buf.as_mut_ptr() as *mut Dirent).as_mut() }.ok_or(SystemError::EFAULT)?; 776 777 if fd < 0 || fd as usize > FileDescriptorVec::PROCESS_MAX_FD { 778 return Err(SystemError::EBADF); 779 } 780 781 // 获取fd 782 let binding = ProcessManager::current_pcb().fd_table(); 783 let fd_table_guard = binding.read(); 784 let file = fd_table_guard 785 .get_file_by_fd(fd) 786 .ok_or(SystemError::EBADF)?; 787 788 // drop guard 以避免无法调度的问题 789 drop(fd_table_guard); 790 791 let res = file.readdir(dirent).map(|x| x as usize); 792 793 return res; 794 } 795 796 /// @brief 创建文件夹 797 /// 798 /// @param path(r8) 路径 / mode(r9) 模式 799 /// 800 /// @return uint64_t 负数错误码 / 0表示成功 mkdir(path: *const u8, mode: usize) -> Result<usize, SystemError>801 pub fn mkdir(path: *const u8, mode: usize) -> Result<usize, SystemError> { 802 let path = check_and_clone_cstr(path, Some(MAX_PATHLEN))? 803 .into_string() 804 .map_err(|_| SystemError::EINVAL)?; 805 806 do_mkdir_at( 807 AtFlags::AT_FDCWD.bits(), 808 &path, 809 FileMode::from_bits_truncate(mode as u32), 810 )?; 811 return Ok(0); 812 } 813 mkdir_at(dirfd: i32, path: *const u8, mode: usize) -> Result<usize, SystemError>814 pub fn mkdir_at(dirfd: i32, path: *const u8, mode: usize) -> Result<usize, SystemError> { 815 let path = check_and_clone_cstr(path, Some(MAX_PATHLEN))? 816 .into_string() 817 .map_err(|_| SystemError::EINVAL)?; 818 do_mkdir_at(dirfd, &path, FileMode::from_bits_truncate(mode as u32))?; 819 return Ok(0); 820 } 821 822 /// **创建硬连接的系统调用** 823 /// 824 /// ## 参数 825 /// 826 /// - 'oldfd': 用于解析源文件路径的文件描述符 827 /// - 'old': 源文件路径 828 /// - 'newfd': 用于解析新文件路径的文件描述符 829 /// - 'new': 新文件将创建的路径 830 /// - 'flags': 标志位，仅以位或方式包含AT_EMPTY_PATH和AT_SYMLINK_FOLLOW 831 /// 832 /// do_linkat( oldfd: i32, old: &str, newfd: i32, new: &str, flags: AtFlags, ) -> Result<usize, SystemError>833 pub fn do_linkat( 834 oldfd: i32, 835 old: &str, 836 newfd: i32, 837 new: &str, 838 flags: AtFlags, 839 ) -> Result<usize, SystemError> { 840 // flag包含其他未规定值时返回EINVAL 841 if !(AtFlags::AT_EMPTY_PATH | AtFlags::AT_SYMLINK_FOLLOW).contains(flags) { 842 return Err(SystemError::EINVAL); 843 } 844 // TODO AT_EMPTY_PATH标志启用时，进行调用者CAP_DAC_READ_SEARCH或相似的检查 845 let symlink_times = if flags.contains(AtFlags::AT_SYMLINK_FOLLOW) { 846 0_usize 847 } else { 848 VFS_MAX_FOLLOW_SYMLINK_TIMES 849 }; 850 let pcb = ProcessManager::current_pcb(); 851 852 // 得到源路径的inode 853 let old_inode: Arc<dyn IndexNode> = if old.is_empty() { 854 if flags.contains(AtFlags::AT_EMPTY_PATH) { 855 // 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。 856 let binding = pcb.fd_table(); 857 let fd_table_guard = binding.read(); 858 let file = fd_table_guard 859 .get_file_by_fd(oldfd) 860 .ok_or(SystemError::EBADF)?; 861 let old_inode = file.inode(); 862 old_inode 863 } else { 864 return Err(SystemError::ENONET); 865 } 866 } else { 867 let (old_begin_inode, old_remain_path) = user_path_at(&pcb, oldfd, old)?; 868 old_begin_inode.lookup_follow_symlink(&old_remain_path, symlink_times)? 869 }; 870 871 // old_inode为目录时返回EPERM 872 if old_inode.metadata().unwrap().file_type == FileType::Dir { 873 return Err(SystemError::EPERM); 874 } 875 876 // 得到新创建节点的父节点 877 let (new_begin_inode, new_remain_path) = user_path_at(&pcb, newfd, new)?; 878 let (new_name, new_parent_path) = rsplit_path(&new_remain_path); 879 let new_parent = 880 new_begin_inode.lookup_follow_symlink(new_parent_path.unwrap_or("/"), symlink_times)?; 881 882 // 被调用者利用downcast_ref判断两inode是否为同一文件系统 883 return new_parent.link(new_name, &old_inode).map(|_| 0); 884 } 885 link(old: *const u8, new: *const u8) -> Result<usize, SystemError>886 pub fn link(old: *const u8, new: *const u8) -> Result<usize, SystemError> { 887 let get_path = |cstr: *const u8| -> Result<String, SystemError> { 888 let res = check_and_clone_cstr(cstr, Some(MAX_PATHLEN))? 889 .into_string() 890 .map_err(|_| SystemError::EINVAL)?; 891 892 if res.len() >= MAX_PATHLEN { 893 return Err(SystemError::ENAMETOOLONG); 894 } 895 if res.is_empty() { 896 return Err(SystemError::ENOENT); 897 } 898 Ok(res) 899 }; 900 let old = get_path(old)?; 901 let new = get_path(new)?; 902 return Self::do_linkat( 903 AtFlags::AT_FDCWD.bits(), 904 &old, 905 AtFlags::AT_FDCWD.bits(), 906 &new, 907 AtFlags::empty(), 908 ); 909 } 910 linkat( oldfd: i32, old: *const u8, newfd: i32, new: *const u8, flags: i32, ) -> Result<usize, SystemError>911 pub fn linkat( 912 oldfd: i32, 913 old: *const u8, 914 newfd: i32, 915 new: *const u8, 916 flags: i32, 917 ) -> Result<usize, SystemError> { 918 let old = check_and_clone_cstr(old, Some(MAX_PATHLEN))? 919 .into_string() 920 .map_err(|_| SystemError::EINVAL)?; 921 let new = check_and_clone_cstr(new, Some(MAX_PATHLEN))? 922 .into_string() 923 .map_err(|_| SystemError::EINVAL)?; 924 if old.len() >= MAX_PATHLEN || new.len() >= MAX_PATHLEN { 925 return Err(SystemError::ENAMETOOLONG); 926 } 927 // old 根据flags & AtFlags::AT_EMPTY_PATH判空 928 if new.is_empty() { 929 return Err(SystemError::ENOENT); 930 } 931 let flags = AtFlags::from_bits(flags).ok_or(SystemError::EINVAL)?; 932 Self::do_linkat(oldfd, &old, newfd, &new, flags) 933 } 934 935 /// **删除文件夹、取消文件的链接、删除文件的系统调用** 936 /// 937 /// ## 参数 938 /// 939 /// - `dirfd`：文件夹的文件描述符.目前暂未实现 940 /// - `pathname`：文件夹的路径 941 /// - `flags`：标志位 942 /// 943 /// unlinkat(dirfd: i32, path: *const u8, flags: u32) -> Result<usize, SystemError>944 pub fn unlinkat(dirfd: i32, path: *const u8, flags: u32) -> Result<usize, SystemError> { 945 let flags = AtFlags::from_bits(flags as i32).ok_or(SystemError::EINVAL)?; 946 947 let path = check_and_clone_cstr(path, Some(MAX_PATHLEN))? 948 .into_string() 949 .map_err(|_| SystemError::EINVAL)?; 950 951 if flags.contains(AtFlags::AT_REMOVEDIR) { 952 // debug!("rmdir"); 953 match do_remove_dir(dirfd, &path) { 954 Err(err) => { 955 return Err(err); 956 } 957 Ok(_) => { 958 return Ok(0); 959 } 960 } 961 } 962 963 match do_unlink_at(dirfd, &path) { 964 Err(err) => { 965 return Err(err); 966 } 967 Ok(_) => { 968 return Ok(0); 969 } 970 } 971 } 972 rmdir(path: *const u8) -> Result<usize, SystemError>973 pub fn rmdir(path: *const u8) -> Result<usize, SystemError> { 974 let path = check_and_clone_cstr(path, Some(MAX_PATHLEN))? 975 .into_string() 976 .map_err(|_| SystemError::EINVAL)?; 977 return do_remove_dir(AtFlags::AT_FDCWD.bits(), &path).map(|v| v as usize); 978 } 979 unlink(path: *const u8) -> Result<usize, SystemError>980 pub fn unlink(path: *const u8) -> Result<usize, SystemError> { 981 let path = check_and_clone_cstr(path, Some(MAX_PATHLEN))? 982 .into_string() 983 .map_err(|_| SystemError::EINVAL)?; 984 return do_unlink_at(AtFlags::AT_FDCWD.bits(), &path).map(|v| v as usize); 985 } 986 symlink(oldname: *const u8, newname: *const u8) -> Result<usize, SystemError>987 pub fn symlink(oldname: *const u8, newname: *const u8) -> Result<usize, SystemError> { 988 return do_symlinkat(oldname, AtFlags::AT_FDCWD.bits(), newname); 989 } 990 symlinkat( oldname: *const u8, newdfd: i32, newname: *const u8, ) -> Result<usize, SystemError>991 pub fn symlinkat( 992 oldname: *const u8, 993 newdfd: i32, 994 newname: *const u8, 995 ) -> Result<usize, SystemError> { 996 return do_symlinkat(oldname, newdfd, newname); 997 } 998 999 /// # 修改文件名 1000 /// 1001 /// 1002 /// ## 参数 1003 /// 1004 /// - oldfd: 源文件夹文件描述符 1005 /// - filename_from: 源文件路径 1006 /// - newfd: 目标文件夹文件描述符 1007 /// - filename_to: 目标文件路径 1008 /// - flags: 标志位 1009 /// 1010 /// 1011 /// ## 返回值 1012 /// - Ok(返回值类型): 返回值的说明 1013 /// - Err(错误值类型): 错误的说明 1014 /// do_renameat2( oldfd: i32, filename_from: *const u8, newfd: i32, filename_to: *const u8, _flags: u32, ) -> Result<usize, SystemError>1015 pub fn do_renameat2( 1016 oldfd: i32, 1017 filename_from: *const u8, 1018 newfd: i32, 1019 filename_to: *const u8, 1020 _flags: u32, 1021 ) -> Result<usize, SystemError> { 1022 let filename_from = check_and_clone_cstr(filename_from, Some(MAX_PATHLEN)) 1023 .unwrap() 1024 .into_string() 1025 .map_err(|_| SystemError::EINVAL)?; 1026 let filename_to = check_and_clone_cstr(filename_to, Some(MAX_PATHLEN)) 1027 .unwrap() 1028 .into_string() 1029 .map_err(|_| SystemError::EINVAL)?; 1030 // 文件名过长 1031 if filename_from.len() > MAX_PATHLEN || filename_to.len() > MAX_PATHLEN { 1032 return Err(SystemError::ENAMETOOLONG); 1033 } 1034 1035 //获取pcb，文件节点 1036 let pcb = ProcessManager::current_pcb(); 1037 let (_old_inode_begin, old_remain_path) = user_path_at(&pcb, oldfd, &filename_from)?; 1038 let (_new_inode_begin, new_remain_path) = user_path_at(&pcb, newfd, &filename_to)?; 1039 //获取父目录 1040 let (old_filename, old_parent_path) = rsplit_path(&old_remain_path); 1041 let old_parent_inode = ROOT_INODE() 1042 .lookup_follow_symlink(old_parent_path.unwrap_or("/"), VFS_MAX_FOLLOW_SYMLINK_TIMES)?; 1043 let (new_filename, new_parent_path) = rsplit_path(&new_remain_path); 1044 let new_parent_inode = ROOT_INODE() 1045 .lookup_follow_symlink(new_parent_path.unwrap_or("/"), VFS_MAX_FOLLOW_SYMLINK_TIMES)?; 1046 old_parent_inode.move_to(old_filename, &new_parent_inode, new_filename)?; 1047 return Ok(0); 1048 } 1049 1050 /// @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 dup(oldfd: i32) -> Result<usize, SystemError>1051 pub fn dup(oldfd: i32) -> Result<usize, SystemError> { 1052 let binding = ProcessManager::current_pcb().fd_table(); 1053 let mut fd_table_guard = binding.write(); 1054 1055 let old_file = fd_table_guard 1056 .get_file_by_fd(oldfd) 1057 .ok_or(SystemError::EBADF)?; 1058 1059 let new_file = old_file.try_clone().ok_or(SystemError::EBADF)?; 1060 // dup默认非cloexec 1061 new_file.set_close_on_exec(false); 1062 // 申请文件描述符，并把文件对象存入其中 1063 let res = fd_table_guard.alloc_fd(new_file, None).map(|x| x as usize); 1064 return res; 1065 } 1066 1067 /// 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， 1068 /// 并返回新复制的文件结构体对应的fd. 1069 /// 如果新fd已经打开，则会先关闭新fd. 1070 /// 1071 /// ## 参数 1072 /// 1073 /// - `oldfd`：旧文件描述符 1074 /// - `newfd`：新文件描述符 1075 /// 1076 /// ## 返回值 1077 /// 1078 /// - 成功：新文件描述符 1079 /// - 失败：错误码 dup2(oldfd: i32, newfd: i32) -> Result<usize, SystemError>1080 pub fn dup2(oldfd: i32, newfd: i32) -> Result<usize, SystemError> { 1081 let binding = ProcessManager::current_pcb().fd_table(); 1082 let mut fd_table_guard = binding.write(); 1083 return Self::do_dup2(oldfd, newfd, &mut fd_table_guard); 1084 } 1085 dup3(oldfd: i32, newfd: i32, flags: u32) -> Result<usize, SystemError>1086 pub fn dup3(oldfd: i32, newfd: i32, flags: u32) -> Result<usize, SystemError> { 1087 let flags = FileMode::from_bits_truncate(flags); 1088 if (flags.bits() & !FileMode::O_CLOEXEC.bits()) != 0 { 1089 return Err(SystemError::EINVAL); 1090 } 1091 1092 if oldfd == newfd { 1093 return Err(SystemError::EINVAL); 1094 } 1095 1096 let binding = ProcessManager::current_pcb().fd_table(); 1097 let mut fd_table_guard = binding.write(); 1098 return Self::do_dup3(oldfd, newfd, flags, &mut fd_table_guard); 1099 } 1100 do_dup2( oldfd: i32, newfd: i32, fd_table_guard: &mut RwLockWriteGuard<'_, FileDescriptorVec>, ) -> Result<usize, SystemError>1101 fn do_dup2( 1102 oldfd: i32, 1103 newfd: i32, 1104 fd_table_guard: &mut RwLockWriteGuard<'_, FileDescriptorVec>, 1105 ) -> Result<usize, SystemError> { 1106 Self::do_dup3(oldfd, newfd, FileMode::empty(), fd_table_guard) 1107 } 1108 do_dup3( oldfd: i32, newfd: i32, flags: FileMode, fd_table_guard: &mut RwLockWriteGuard<'_, FileDescriptorVec>, ) -> Result<usize, SystemError>1109 fn do_dup3( 1110 oldfd: i32, 1111 newfd: i32, 1112 flags: FileMode, 1113 fd_table_guard: &mut RwLockWriteGuard<'_, FileDescriptorVec>, 1114 ) -> Result<usize, SystemError> { 1115 // 确认oldfd, newid是否有效 1116 if !(FileDescriptorVec::validate_fd(oldfd) && FileDescriptorVec::validate_fd(newfd)) { 1117 return Err(SystemError::EBADF); 1118 } 1119 1120 if oldfd == newfd { 1121 // 若oldfd与newfd相等 1122 return Ok(newfd as usize); 1123 } 1124 let new_exists = fd_table_guard.get_file_by_fd(newfd).is_some(); 1125 if new_exists { 1126 // close newfd 1127 if fd_table_guard.drop_fd(newfd).is_err() { 1128 // An I/O error occurred while attempting to close fildes2. 1129 return Err(SystemError::EIO); 1130 } 1131 } 1132 1133 let old_file = fd_table_guard 1134 .get_file_by_fd(oldfd) 1135 .ok_or(SystemError::EBADF)?; 1136 let new_file = old_file.try_clone().ok_or(SystemError::EBADF)?; 1137 1138 if flags.contains(FileMode::O_CLOEXEC) { 1139 new_file.set_close_on_exec(true); 1140 } else { 1141 new_file.set_close_on_exec(false); 1142 } 1143 // 申请文件描述符，并把文件对象存入其中 1144 let res = fd_table_guard 1145 .alloc_fd(new_file, Some(newfd)) 1146 .map(|x| x as usize); 1147 return res; 1148 } 1149 1150 /// # fcntl 1151 /// 1152 /// ## 参数 1153 /// 1154 /// - `fd`：文件描述符 1155 /// - `cmd`：命令 1156 /// - `arg`：参数 fcntl(fd: i32, cmd: FcntlCommand, arg: i32) -> Result<usize, SystemError>1157 pub fn fcntl(fd: i32, cmd: FcntlCommand, arg: i32) -> Result<usize, SystemError> { 1158 // debug!("fcntl ({cmd:?}) fd: {fd}, arg={arg}"); 1159 match cmd { 1160 FcntlCommand::DupFd | FcntlCommand::DupFdCloexec => { 1161 if arg < 0 || arg as usize >= FileDescriptorVec::PROCESS_MAX_FD { 1162 return Err(SystemError::EBADF); 1163 } 1164 let arg = arg as usize; 1165 for i in arg..FileDescriptorVec::PROCESS_MAX_FD { 1166 let binding = ProcessManager::current_pcb().fd_table(); 1167 let mut fd_table_guard = binding.write(); 1168 if fd_table_guard.get_file_by_fd(i as i32).is_none() { 1169 if cmd == FcntlCommand::DupFd { 1170 return Self::do_dup2(fd, i as i32, &mut fd_table_guard); 1171 } else { 1172 return Self::do_dup3( 1173 fd, 1174 i as i32, 1175 FileMode::O_CLOEXEC, 1176 &mut fd_table_guard, 1177 ); 1178 } 1179 } 1180 } 1181 return Err(SystemError::EMFILE); 1182 } 1183 FcntlCommand::GetFd => { 1184 // Get file descriptor flags. 1185 let binding = ProcessManager::current_pcb().fd_table(); 1186 let fd_table_guard = binding.read(); 1187 1188 if let Some(file) = fd_table_guard.get_file_by_fd(fd) { 1189 // drop guard 以避免无法调度的问题 1190 drop(fd_table_guard); 1191 1192 if file.close_on_exec() { 1193 return Ok(FD_CLOEXEC as usize); 1194 } else { 1195 return Ok(0); 1196 } 1197 } 1198 return Err(SystemError::EBADF); 1199 } 1200 FcntlCommand::SetFd => { 1201 // Set file descriptor flags. 1202 let binding = ProcessManager::current_pcb().fd_table(); 1203 let fd_table_guard = binding.write(); 1204 1205 if let Some(file) = fd_table_guard.get_file_by_fd(fd) { 1206 // drop guard 以避免无法调度的问题 1207 drop(fd_table_guard); 1208 let arg = arg as u32; 1209 if arg & FD_CLOEXEC != 0 { 1210 file.set_close_on_exec(true); 1211 } else { 1212 file.set_close_on_exec(false); 1213 } 1214 return Ok(0); 1215 } 1216 return Err(SystemError::EBADF); 1217 } 1218 1219 FcntlCommand::GetFlags => { 1220 // Get file status flags. 1221 let binding = ProcessManager::current_pcb().fd_table(); 1222 let fd_table_guard = binding.read(); 1223 1224 if let Some(file) = fd_table_guard.get_file_by_fd(fd) { 1225 // drop guard 以避免无法调度的问题 1226 drop(fd_table_guard); 1227 return Ok(file.mode().bits() as usize); 1228 } 1229 1230 return Err(SystemError::EBADF); 1231 } 1232 FcntlCommand::SetFlags => { 1233 // Set file status flags. 1234 let binding = ProcessManager::current_pcb().fd_table(); 1235 let fd_table_guard = binding.write(); 1236 1237 if let Some(file) = fd_table_guard.get_file_by_fd(fd) { 1238 let arg = arg as u32; 1239 let mode = FileMode::from_bits(arg).ok_or(SystemError::EINVAL)?; 1240 // drop guard 以避免无法调度的问题 1241 drop(fd_table_guard); 1242 file.set_mode(mode)?; 1243 return Ok(0); 1244 } 1245 1246 return Err(SystemError::EBADF); 1247 } 1248 _ => { 1249 // TODO: unimplemented 1250 // 未实现的命令，返回0，不报错。 1251 1252 warn!("fcntl: unimplemented command: {:?}, defaults to 0.", cmd); 1253 return Err(SystemError::ENOSYS); 1254 } 1255 } 1256 } 1257 1258 /// # ftruncate 1259 /// 1260 /// ## 描述 1261 /// 1262 /// 改变文件大小. 1263 /// 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. 1264 /// 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. 1265 /// 1266 /// ## 参数 1267 /// 1268 /// - `fd`：文件描述符 1269 /// - `len`：文件大小 1270 /// 1271 /// ## 返回值 1272 /// 1273 /// 如果成功，返回0，否则返回错误码. ftruncate(fd: i32, len: usize) -> Result<usize, SystemError>1274 pub fn ftruncate(fd: i32, len: usize) -> Result<usize, SystemError> { 1275 let binding = ProcessManager::current_pcb().fd_table(); 1276 let fd_table_guard = binding.read(); 1277 1278 if let Some(file) = fd_table_guard.get_file_by_fd(fd) { 1279 // drop guard 以避免无法调度的问题 1280 drop(fd_table_guard); 1281 let r = file.ftruncate(len).map(|_| 0); 1282 return r; 1283 } 1284 1285 return Err(SystemError::EBADF); 1286 } 1287 do_fstat(fd: i32) -> Result<PosixKstat, SystemError>1288 fn do_fstat(fd: i32) -> Result<PosixKstat, SystemError> { 1289 let binding = ProcessManager::current_pcb().fd_table(); 1290 let fd_table_guard = binding.read(); 1291 let file = fd_table_guard 1292 .get_file_by_fd(fd) 1293 .ok_or(SystemError::EBADF)?; 1294 // drop guard 以避免无法调度的问题 1295 drop(fd_table_guard); 1296 1297 let mut kstat = PosixKstat::new(); 1298 // 获取文件信息 1299 let metadata = file.metadata()?; 1300 kstat.size = metadata.size; 1301 kstat.dev_id = metadata.dev_id as u64; 1302 kstat.inode = metadata.inode_id.into() as u64; 1303 kstat.blcok_size = metadata.blk_size as i64; 1304 kstat.blocks = metadata.blocks as u64; 1305 1306 kstat.atime.tv_sec = metadata.atime.tv_sec; 1307 kstat.atime.tv_nsec = metadata.atime.tv_nsec; 1308 kstat.mtime.tv_sec = metadata.mtime.tv_sec; 1309 kstat.mtime.tv_nsec = metadata.mtime.tv_nsec; 1310 kstat.ctime.tv_sec = metadata.ctime.tv_sec; 1311 kstat.ctime.tv_nsec = metadata.ctime.tv_nsec; 1312 1313 kstat.nlink = metadata.nlinks as u64; 1314 kstat.uid = metadata.uid as i32; 1315 kstat.gid = metadata.gid as i32; 1316 kstat.rdev = metadata.raw_dev.data() as i64; 1317 kstat.mode = metadata.mode; 1318 match file.file_type() { 1319 FileType::File => kstat.mode.insert(ModeType::S_IFREG), 1320 FileType::Dir => kstat.mode.insert(ModeType::S_IFDIR), 1321 FileType::BlockDevice => kstat.mode.insert(ModeType::S_IFBLK), 1322 FileType::CharDevice => kstat.mode.insert(ModeType::S_IFCHR), 1323 FileType::SymLink => kstat.mode.insert(ModeType::S_IFLNK), 1324 FileType::Socket => kstat.mode.insert(ModeType::S_IFSOCK), 1325 FileType::Pipe => kstat.mode.insert(ModeType::S_IFIFO), 1326 FileType::KvmDevice => kstat.mode.insert(ModeType::S_IFCHR), 1327 FileType::FramebufferDevice => kstat.mode.insert(ModeType::S_IFCHR), 1328 } 1329 1330 return Ok(kstat); 1331 } 1332 fstat(fd: i32, usr_kstat: *mut PosixKstat) -> Result<usize, SystemError>1333 pub fn fstat(fd: i32, usr_kstat: *mut PosixKstat) -> Result<usize, SystemError> { 1334 let mut writer = UserBufferWriter::new(usr_kstat, size_of::<PosixKstat>(), true)?; 1335 let kstat = Self::do_fstat(fd)?; 1336 1337 writer.copy_one_to_user(&kstat, 0)?; 1338 return Ok(0); 1339 } 1340 stat(path: *const u8, user_kstat: *mut PosixKstat) -> Result<usize, SystemError>1341 pub fn stat(path: *const u8, user_kstat: *mut PosixKstat) -> Result<usize, SystemError> { 1342 let fd = Self::open( 1343 path, 1344 FileMode::O_RDONLY.bits(), 1345 ModeType::empty().bits(), 1346 true, 1347 )?; 1348 let r = Self::fstat(fd as i32, user_kstat); 1349 Self::close(fd).ok(); 1350 return r; 1351 } 1352 lstat(path: *const u8, user_kstat: *mut PosixKstat) -> Result<usize, SystemError>1353 pub fn lstat(path: *const u8, user_kstat: *mut PosixKstat) -> Result<usize, SystemError> { 1354 let fd = Self::open( 1355 path, 1356 FileMode::O_RDONLY.bits(), 1357 ModeType::empty().bits(), 1358 false, 1359 )?; 1360 let r = Self::fstat(fd as i32, user_kstat); 1361 Self::close(fd).ok(); 1362 return r; 1363 } 1364 statfs(path: *const u8, user_statfs: *mut PosixStatfs) -> Result<usize, SystemError>1365 pub fn statfs(path: *const u8, user_statfs: *mut PosixStatfs) -> Result<usize, SystemError> { 1366 let mut writer = UserBufferWriter::new(user_statfs, size_of::<PosixStatfs>(), true)?; 1367 let fd = Self::open( 1368 path, 1369 FileMode::O_RDONLY.bits(), 1370 ModeType::empty().bits(), 1371 true, 1372 )?; 1373 let path = check_and_clone_cstr(path, Some(MAX_PATHLEN)) 1374 .unwrap() 1375 .into_string() 1376 .map_err(|_| SystemError::EINVAL)?; 1377 let pcb = ProcessManager::current_pcb(); 1378 let (_inode_begin, remain_path) = user_path_at(&pcb, fd as i32, &path)?; 1379 let inode = ROOT_INODE().lookup_follow_symlink(&remain_path, MAX_PATHLEN)?; 1380 let statfs = PosixStatfs::from(inode.fs().super_block()); 1381 writer.copy_one_to_user(&statfs, 0)?; 1382 return Ok(0); 1383 } 1384 fstatfs(fd: i32, user_statfs: *mut PosixStatfs) -> Result<usize, SystemError>1385 pub fn fstatfs(fd: i32, user_statfs: *mut PosixStatfs) -> Result<usize, SystemError> { 1386 let mut writer = UserBufferWriter::new(user_statfs, size_of::<PosixStatfs>(), true)?; 1387 let binding = ProcessManager::current_pcb().fd_table(); 1388 let fd_table_guard = binding.read(); 1389 let file = fd_table_guard 1390 .get_file_by_fd(fd) 1391 .ok_or(SystemError::EBADF)?; 1392 drop(fd_table_guard); 1393 let statfs = PosixStatfs::from(file.inode().fs().super_block()); 1394 writer.copy_one_to_user(&statfs, 0)?; 1395 return Ok(0); 1396 } 1397 do_statx( fd: i32, path: *const u8, flags: u32, mask: u32, usr_kstat: *mut PosixStatx, ) -> Result<usize, SystemError>1398 pub fn do_statx( 1399 fd: i32, 1400 path: *const u8, 1401 flags: u32, 1402 mask: u32, 1403 usr_kstat: *mut PosixStatx, 1404 ) -> Result<usize, SystemError> { 1405 if usr_kstat.is_null() { 1406 return Err(SystemError::EFAULT); 1407 } 1408 1409 let mask = PosixStatxMask::from_bits_truncate(mask); 1410 1411 if mask.contains(PosixStatxMask::STATX_RESERVED) { 1412 return Err(SystemError::ENAVAIL); 1413 } 1414 1415 let flags = FileMode::from_bits_truncate(flags); 1416 let ofd = Self::open(path, flags.bits(), ModeType::empty().bits, true)?; 1417 1418 let binding = ProcessManager::current_pcb().fd_table(); 1419 let fd_table_guard = binding.read(); 1420 let file = fd_table_guard 1421 .get_file_by_fd(ofd as i32) 1422 .ok_or(SystemError::EBADF)?; 1423 // drop guard 以避免无法调度的问题 1424 drop(fd_table_guard); 1425 let mut writer = UserBufferWriter::new(usr_kstat, size_of::<PosixStatx>(), true)?; 1426 let mut tmp: PosixStatx = PosixStatx::new(); 1427 // 获取文件信息 1428 let metadata = file.metadata()?; 1429 1430 tmp.stx_mask |= PosixStatxMask::STATX_BASIC_STATS; 1431 tmp.stx_blksize = metadata.blk_size as u32; 1432 if mask.contains(PosixStatxMask::STATX_MODE) || mask.contains(PosixStatxMask::STATX_TYPE) { 1433 tmp.stx_mode = metadata.mode; 1434 } 1435 if mask.contains(PosixStatxMask::STATX_NLINK) { 1436 tmp.stx_nlink = metadata.nlinks as u32; 1437 } 1438 if mask.contains(PosixStatxMask::STATX_UID) { 1439 tmp.stx_uid = metadata.uid as u32; 1440 } 1441 if mask.contains(PosixStatxMask::STATX_GID) { 1442 tmp.stx_gid = metadata.gid as u32; 1443 } 1444 if mask.contains(PosixStatxMask::STATX_ATIME) { 1445 tmp.stx_atime.tv_sec = metadata.atime.tv_sec; 1446 tmp.stx_atime.tv_nsec = metadata.atime.tv_nsec; 1447 } 1448 if mask.contains(PosixStatxMask::STATX_MTIME) { 1449 tmp.stx_mtime.tv_sec = metadata.ctime.tv_sec; 1450 tmp.stx_mtime.tv_nsec = metadata.ctime.tv_nsec; 1451 } 1452 if mask.contains(PosixStatxMask::STATX_CTIME) { 1453 // ctime是文件上次修改状态的时间 1454 tmp.stx_ctime.tv_sec = metadata.mtime.tv_sec; 1455 tmp.stx_ctime.tv_nsec = metadata.mtime.tv_nsec; 1456 } 1457 if mask.contains(PosixStatxMask::STATX_INO) { 1458 tmp.stx_inode = metadata.inode_id.into() as u64; 1459 } 1460 if mask.contains(PosixStatxMask::STATX_SIZE) { 1461 tmp.stx_size = metadata.size; 1462 } 1463 if mask.contains(PosixStatxMask::STATX_BLOCKS) { 1464 tmp.stx_blocks = metadata.blocks as u64; 1465 } 1466 1467 if mask.contains(PosixStatxMask::STATX_BTIME) { 1468 // btime是文件创建时间 1469 tmp.stx_btime.tv_sec = metadata.ctime.tv_sec; 1470 tmp.stx_btime.tv_nsec = metadata.ctime.tv_nsec; 1471 } 1472 if mask.contains(PosixStatxMask::STATX_ALL) { 1473 tmp.stx_attributes = StxAttributes::STATX_ATTR_APPEND; 1474 tmp.stx_attributes_mask |= 1475 StxAttributes::STATX_ATTR_AUTOMOUNT | StxAttributes::STATX_ATTR_DAX; 1476 tmp.stx_dev_major = metadata.dev_id as u32; 1477 tmp.stx_dev_minor = metadata.dev_id as u32; // 1478 tmp.stx_rdev_major = metadata.raw_dev.data(); 1479 tmp.stx_rdev_minor = metadata.raw_dev.data(); 1480 } 1481 if mask.contains(PosixStatxMask::STATX_MNT_ID) { 1482 tmp.stx_mnt_id = 0; 1483 } 1484 if mask.contains(PosixStatxMask::STATX_DIOALIGN) { 1485 tmp.stx_dio_mem_align = 0; 1486 tmp.stx_dio_offset_align = 0; 1487 } 1488 1489 match file.file_type() { 1490 FileType::File => tmp.stx_mode.insert(ModeType::S_IFREG), 1491 FileType::Dir => tmp.stx_mode.insert(ModeType::S_IFDIR), 1492 FileType::BlockDevice => tmp.stx_mode.insert(ModeType::S_IFBLK), 1493 FileType::CharDevice => tmp.stx_mode.insert(ModeType::S_IFCHR), 1494 FileType::SymLink => tmp.stx_mode.insert(ModeType::S_IFLNK), 1495 FileType::Socket => tmp.stx_mode.insert(ModeType::S_IFSOCK), 1496 FileType::Pipe => tmp.stx_mode.insert(ModeType::S_IFIFO), 1497 FileType::KvmDevice => tmp.stx_mode.insert(ModeType::S_IFCHR), 1498 FileType::FramebufferDevice => tmp.stx_mode.insert(ModeType::S_IFCHR), 1499 } 1500 1501 writer.copy_one_to_user(&tmp, 0)?; 1502 Self::close(fd as usize).ok(); 1503 return Ok(0); 1504 } 1505 mknod( path: *const u8, mode: ModeType, dev_t: DeviceNumber, ) -> Result<usize, SystemError>1506 pub fn mknod( 1507 path: *const u8, 1508 mode: ModeType, 1509 dev_t: DeviceNumber, 1510 ) -> Result<usize, SystemError> { 1511 let path = check_and_clone_cstr(path, Some(MAX_PATHLEN))? 1512 .into_string() 1513 .map_err(|_| SystemError::EINVAL)?; 1514 let path = path.as_str().trim(); 1515 1516 let inode: Result<Arc<dyn IndexNode>, SystemError> = 1517 ROOT_INODE().lookup_follow_symlink(path, VFS_MAX_FOLLOW_SYMLINK_TIMES); 1518 1519 if inode.is_ok() { 1520 return Err(SystemError::EEXIST); 1521 } 1522 1523 let (filename, parent_path) = rsplit_path(path); 1524 1525 // 查找父目录 1526 let parent_inode: Arc<dyn IndexNode> = ROOT_INODE() 1527 .lookup_follow_symlink(parent_path.unwrap_or("/"), VFS_MAX_FOLLOW_SYMLINK_TIMES)?; 1528 // 创建nod 1529 parent_inode.mknod(filename, mode, dev_t)?; 1530 1531 return Ok(0); 1532 } 1533 writev(fd: i32, iov: usize, count: usize) -> Result<usize, SystemError>1534 pub fn writev(fd: i32, iov: usize, count: usize) -> Result<usize, SystemError> { 1535 // IoVecs会进行用户态检验 1536 let iovecs = unsafe { IoVecs::from_user(iov as *const IoVec, count, false) }?; 1537 1538 let data = iovecs.gather(); 1539 1540 Self::write(fd, &data) 1541 } 1542 readv(fd: i32, iov: usize, count: usize) -> Result<usize, SystemError>1543 pub fn readv(fd: i32, iov: usize, count: usize) -> Result<usize, SystemError> { 1544 // IoVecs会进行用户态检验 1545 let mut iovecs = unsafe { IoVecs::from_user(iov as *const IoVec, count, true) }?; 1546 1547 let mut data = vec![0; iovecs.0.iter().map(|x| x.len()).sum()]; 1548 1549 let len = Self::read(fd, &mut data)?; 1550 1551 iovecs.scatter(&data[..len]); 1552 1553 return Ok(len); 1554 } 1555 readlink_at( dirfd: i32, path: *const u8, user_buf: *mut u8, buf_size: usize, ) -> Result<usize, SystemError>1556 pub fn readlink_at( 1557 dirfd: i32, 1558 path: *const u8, 1559 user_buf: *mut u8, 1560 buf_size: usize, 1561 ) -> Result<usize, SystemError> { 1562 let path = check_and_clone_cstr(path, Some(MAX_PATHLEN))? 1563 .into_string() 1564 .map_err(|_| SystemError::EINVAL)?; 1565 let path = path.as_str().trim(); 1566 let mut user_buf = UserBufferWriter::new(user_buf, buf_size, true)?; 1567 1568 let (inode, path) = user_path_at(&ProcessManager::current_pcb(), dirfd, path)?; 1569 1570 let inode = inode.lookup(path.as_str())?; 1571 if inode.metadata()?.file_type != FileType::SymLink { 1572 return Err(SystemError::EINVAL); 1573 } 1574 1575 let ubuf = user_buf.buffer::<u8>(0).unwrap(); 1576 1577 let file = File::new(inode, FileMode::O_RDONLY)?; 1578 1579 let len = file.read(buf_size, ubuf)?; 1580 1581 return Ok(len); 1582 } 1583 readlink( path: *const u8, user_buf: *mut u8, buf_size: usize, ) -> Result<usize, SystemError>1584 pub fn readlink( 1585 path: *const u8, 1586 user_buf: *mut u8, 1587 buf_size: usize, 1588 ) -> Result<usize, SystemError> { 1589 return Self::readlink_at(AtFlags::AT_FDCWD.bits(), path, user_buf, buf_size); 1590 } 1591 access(pathname: *const u8, mode: u32) -> Result<usize, SystemError>1592 pub fn access(pathname: *const u8, mode: u32) -> Result<usize, SystemError> { 1593 return do_faccessat( 1594 AtFlags::AT_FDCWD.bits(), 1595 pathname, 1596 ModeType::from_bits(mode).ok_or(SystemError::EINVAL)?, 1597 0, 1598 ); 1599 } 1600 faccessat2( dirfd: i32, pathname: *const u8, mode: u32, flags: u32, ) -> Result<usize, SystemError>1601 pub fn faccessat2( 1602 dirfd: i32, 1603 pathname: *const u8, 1604 mode: u32, 1605 flags: u32, 1606 ) -> Result<usize, SystemError> { 1607 return do_faccessat( 1608 dirfd, 1609 pathname, 1610 ModeType::from_bits(mode).ok_or(SystemError::EINVAL)?, 1611 flags, 1612 ); 1613 } 1614 chmod(pathname: *const u8, mode: u32) -> Result<usize, SystemError>1615 pub fn chmod(pathname: *const u8, mode: u32) -> Result<usize, SystemError> { 1616 return do_fchmodat( 1617 AtFlags::AT_FDCWD.bits(), 1618 pathname, 1619 ModeType::from_bits(mode).ok_or(SystemError::EINVAL)?, 1620 ); 1621 } 1622 fchmodat(dirfd: i32, pathname: *const u8, mode: u32) -> Result<usize, SystemError>1623 pub fn fchmodat(dirfd: i32, pathname: *const u8, mode: u32) -> Result<usize, SystemError> { 1624 return do_fchmodat( 1625 dirfd, 1626 pathname, 1627 ModeType::from_bits(mode).ok_or(SystemError::EINVAL)?, 1628 ); 1629 } 1630 fchmod(fd: i32, mode: u32) -> Result<usize, SystemError>1631 pub fn fchmod(fd: i32, mode: u32) -> Result<usize, SystemError> { 1632 let _mode = ModeType::from_bits(mode).ok_or(SystemError::EINVAL)?; 1633 let binding = ProcessManager::current_pcb().fd_table(); 1634 let fd_table_guard = binding.read(); 1635 let _file = fd_table_guard 1636 .get_file_by_fd(fd) 1637 .ok_or(SystemError::EBADF)?; 1638 1639 // fchmod没完全实现，因此不修改文件的权限 1640 // todo: 实现fchmod 1641 warn!("fchmod not fully implemented"); 1642 return Ok(0); 1643 } 1644 chown(pathname: *const u8, uid: usize, gid: usize) -> Result<usize, SystemError>1645 pub fn chown(pathname: *const u8, uid: usize, gid: usize) -> Result<usize, SystemError> { 1646 let pathname = user_access::check_and_clone_cstr(pathname, Some(MAX_PATHLEN))? 1647 .into_string() 1648 .map_err(|_| SystemError::EINVAL)?; 1649 return do_fchownat( 1650 AtFlags::AT_FDCWD.bits(), 1651 &pathname, 1652 uid, 1653 gid, 1654 AtFlags::AT_STATX_SYNC_AS_STAT, 1655 ); 1656 } 1657 lchown(pathname: *const u8, uid: usize, gid: usize) -> Result<usize, SystemError>1658 pub fn lchown(pathname: *const u8, uid: usize, gid: usize) -> Result<usize, SystemError> { 1659 let pathname = user_access::check_and_clone_cstr(pathname, Some(MAX_PATHLEN))? 1660 .into_string() 1661 .map_err(|_| SystemError::EINVAL)?; 1662 return do_fchownat( 1663 AtFlags::AT_FDCWD.bits(), 1664 &pathname, 1665 uid, 1666 gid, 1667 AtFlags::AT_SYMLINK_NOFOLLOW, 1668 ); 1669 } 1670 fchownat( dirfd: i32, pathname: *const u8, uid: usize, gid: usize, flags: i32, ) -> Result<usize, SystemError>1671 pub fn fchownat( 1672 dirfd: i32, 1673 pathname: *const u8, 1674 uid: usize, 1675 gid: usize, 1676 flags: i32, 1677 ) -> Result<usize, SystemError> { 1678 let pathname = user_access::check_and_clone_cstr(pathname, Some(MAX_PATHLEN))? 1679 .into_string() 1680 .map_err(|_| SystemError::EINVAL)?; 1681 let pathname = pathname.as_str().trim(); 1682 let flags = AtFlags::from_bits_truncate(flags); 1683 return do_fchownat(dirfd, pathname, uid, gid, flags); 1684 } 1685 fchown(fd: i32, uid: usize, gid: usize) -> Result<usize, SystemError>1686 pub fn fchown(fd: i32, uid: usize, gid: usize) -> Result<usize, SystemError> { 1687 return ksys_fchown(fd, uid, gid); 1688 } 1689 1690 /// #挂载文件系统 1691 /// 1692 /// 用于挂载文件系统,目前仅支持ramfs挂载 1693 /// 1694 /// ## 参数: 1695 /// 1696 /// - source 挂载设备(暂时不支持) 1697 /// - target 挂载目录 1698 /// - filesystemtype 文件系统 1699 /// - mountflags 挂载选项（暂未实现） 1700 /// - data 带数据挂载 1701 /// 1702 /// ## 返回值 1703 /// - Ok(0): 挂载成功 1704 /// - Err(SystemError) :挂载过程中出错 mount( _source: *const u8, target: *const u8, filesystemtype: *const u8, _mountflags: usize, data: *const u8, ) -> Result<usize, SystemError>1705 pub fn mount( 1706 _source: *const u8, 1707 target: *const u8, 1708 filesystemtype: *const u8, 1709 _mountflags: usize, 1710 data: *const u8, 1711 ) -> Result<usize, SystemError> { 1712 let target = user_access::check_and_clone_cstr(target, Some(MAX_PATHLEN))? 1713 .into_string() 1714 .map_err(|_| SystemError::EINVAL)?; 1715 1716 let fstype_str = user_access::check_and_clone_cstr(filesystemtype, Some(MAX_PATHLEN))?; 1717 let fstype_str = fstype_str.to_str().map_err(|_| SystemError::EINVAL)?; 1718 1719 let fstype = producefs!(FSMAKER, fstype_str, data)?; 1720 1721 Vcore::do_mount(fstype, &target)?; 1722 1723 return Ok(0); 1724 } 1725 1726 // 想法：可以在VFS中实现一个文件系统分发器，流程如下： 1727 // 1. 接受从上方传来的文件类型字符串 1728 // 2. 将传入值与启动时准备好的字符串数组逐个比较（probe） 1729 // 3. 直接在函数内调用构造方法并直接返回文件系统对象 1730 1731 /// src/linux/mount.c `umount` & `umount2` 1732 /// 1733 /// [umount(2) — Linux manual page](https://www.man7.org/linux/man-pages/man2/umount.2.html) umount2(target: *const u8, flags: i32) -> Result<(), SystemError>1734 pub fn umount2(target: *const u8, flags: i32) -> Result<(), SystemError> { 1735 let target = user_access::check_and_clone_cstr(target, Some(MAX_PATHLEN))? 1736 .into_string() 1737 .map_err(|_| SystemError::EINVAL)?; 1738 Vcore::do_umount2( 1739 AtFlags::AT_FDCWD.bits(), 1740 &target, 1741 UmountFlag::from_bits(flags).ok_or(SystemError::EINVAL)?, 1742 )?; 1743 return Ok(()); 1744 } 1745 sys_utimensat( dirfd: i32, pathname: *const u8, times: *const PosixTimeSpec, flags: u32, ) -> Result<usize, SystemError>1746 pub fn sys_utimensat( 1747 dirfd: i32, 1748 pathname: *const u8, 1749 times: *const PosixTimeSpec, 1750 flags: u32, 1751 ) -> Result<usize, SystemError> { 1752 let pathname = if pathname.is_null() { 1753 None 1754 } else { 1755 let pathname = check_and_clone_cstr(pathname, Some(MAX_PATHLEN))? 1756 .into_string() 1757 .map_err(|_| SystemError::EINVAL)?; 1758 Some(pathname) 1759 }; 1760 let flags = UtimensFlags::from_bits(flags).ok_or(SystemError::EINVAL)?; 1761 let times = if times.is_null() { 1762 None 1763 } else { 1764 let times_reader = UserBufferReader::new(times, size_of::<PosixTimeSpec>() * 2, true)?; 1765 let times = times_reader.read_from_user::<PosixTimeSpec>(0)?; 1766 Some([times[0], times[1]]) 1767 }; 1768 do_utimensat(dirfd, pathname, times, flags) 1769 } 1770 sys_utimes( pathname: *const u8, times: *const PosixTimeval, ) -> Result<usize, SystemError>1771 pub fn sys_utimes( 1772 pathname: *const u8, 1773 times: *const PosixTimeval, 1774 ) -> Result<usize, SystemError> { 1775 let pathname = check_and_clone_cstr(pathname, Some(MAX_PATHLEN))? 1776 .into_string() 1777 .map_err(|_| SystemError::EINVAL)?; 1778 let times = if times.is_null() { 1779 None 1780 } else { 1781 let times_reader = UserBufferReader::new(times, size_of::<PosixTimeval>() * 2, true)?; 1782 let times = times_reader.read_from_user::<PosixTimeval>(0)?; 1783 Some([times[0], times[1]]) 1784 }; 1785 do_utimes(&pathname, times) 1786 } 1787 } 1788 1789 #[repr(C)] 1790 #[derive(Debug, Clone, Copy)] 1791 pub struct IoVec { 1792 /// 缓冲区的起始地址 1793 pub iov_base: *mut u8, 1794 /// 缓冲区的长度 1795 pub iov_len: usize, 1796 } 1797 1798 /// 用于存储多个来自用户空间的IoVec 1799 /// 1800 /// 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。 1801 /// TODO：支持分散读写 1802 #[derive(Debug)] 1803 pub struct IoVecs(Vec<&'static mut [u8]>); 1804 1805 impl IoVecs { 1806 /// 从用户空间的IoVec中构造IoVecs 1807 /// 1808 /// @param iov 用户空间的IoVec 1809 /// @param iovcnt 用户空间的IoVec的数量 1810 /// @param readv 是否为readv系统调用 1811 /// 1812 /// @return 构造成功返回IoVecs，否则返回错误码 from_user( iov: *const IoVec, iovcnt: usize, _readv: bool, ) -> Result<Self, SystemError>1813 pub unsafe fn from_user( 1814 iov: *const IoVec, 1815 iovcnt: usize, 1816 _readv: bool, 1817 ) -> Result<Self, SystemError> { 1818 // 检查iov指针所在空间是否合法 1819 verify_area( 1820 VirtAddr::new(iov as usize), 1821 iovcnt * core::mem::size_of::<IoVec>(), 1822 ) 1823 .map_err(|_| SystemError::EFAULT)?; 1824 1825 // 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） 1826 let iovs: &[IoVec] = core::slice::from_raw_parts(iov, iovcnt); 1827 1828 let mut slices: Vec<&mut [u8]> = Vec::with_capacity(iovs.len()); 1829 1830 for iov in iovs.iter() { 1831 if iov.iov_len == 0 { 1832 continue; 1833 } 1834 1835 verify_area( 1836 VirtAddr::new(iov.iov_base as usize), 1837 iovcnt * core::mem::size_of::<IoVec>(), 1838 ) 1839 .map_err(|_| SystemError::EFAULT)?; 1840 1841 slices.push(core::slice::from_raw_parts_mut(iov.iov_base, iov.iov_len)); 1842 } 1843 1844 return Ok(Self(slices)); 1845 } 1846 1847 /// @brief 将IoVecs中的数据聚合到一个缓冲区中 1848 /// 1849 /// @return 返回聚合后的缓冲区 gather(&self) -> Vec<u8>1850 pub fn gather(&self) -> Vec<u8> { 1851 let mut buf = Vec::new(); 1852 for slice in self.0.iter() { 1853 buf.extend_from_slice(slice); 1854 } 1855 return buf; 1856 } 1857 1858 /// @brief 将给定的数据分散写入到IoVecs中 scatter(&mut self, data: &[u8])1859 pub fn scatter(&mut self, data: &[u8]) { 1860 let mut data: &[u8] = data; 1861 for slice in self.0.iter_mut() { 1862 let len = core::cmp::min(slice.len(), data.len()); 1863 if len == 0 { 1864 continue; 1865 } 1866 1867 slice[..len].copy_from_slice(&data[..len]); 1868 data = &data[len..]; 1869 } 1870 } 1871 1872 /// @brief 创建与IoVecs等长的缓冲区 1873 /// 1874 /// @param set_len 是否设置返回的Vec的len。 1875 /// 如果为true，则返回的Vec的len为所有IoVec的长度之和; 1876 /// 否则返回的Vec的len为0，capacity为所有IoVec的长度之和. 1877 /// 1878 /// @return 返回创建的缓冲区 new_buf(&self, set_len: bool) -> Vec<u8>1879 pub fn new_buf(&self, set_len: bool) -> Vec<u8> { 1880 let total_len: usize = self.0.iter().map(|slice| slice.len()).sum(); 1881 let mut buf: Vec<u8> = Vec::with_capacity(total_len); 1882 1883 if set_len { 1884 buf.resize(total_len, 0); 1885 } 1886 return buf; 1887 } 1888 } 1889