1 use core::{cmp::min, fmt::Debug, intrinsics::unlikely}; 2 3 use alloc::{ 4 string::String, 5 sync::{Arc, Weak}, 6 vec::Vec, 7 }; 8 use hashbrown::HashMap; 9 use system_error::SystemError; 10 11 use crate::{ 12 libs::{ 13 casting::DowncastArc, 14 rwlock::RwLock, 15 spinlock::{SpinLock, SpinLockGuard}, 16 }, 17 time::TimeSpec, 18 }; 19 20 use self::callback::{KernCallbackData, KernFSCallback, KernInodePrivateData}; 21 22 use super::vfs::{ 23 core::generate_inode_id, file::FileMode, syscall::ModeType, FilePrivateData, FileSystem, 24 FileType, FsInfo, IndexNode, InodeId, Metadata, 25 }; 26 27 pub mod callback; 28 29 #[derive(Debug)] 30 pub struct KernFS { 31 root_inode: Arc<KernFSInode>, 32 } 33 34 impl FileSystem for KernFS { 35 fn as_any_ref(&self) -> &dyn core::any::Any { 36 self 37 } 38 39 fn info(&self) -> FsInfo { 40 return FsInfo { 41 blk_dev_id: 0, 42 max_name_len: KernFS::MAX_NAMELEN, 43 }; 44 } 45 46 fn root_inode(&self) -> Arc<dyn IndexNode> { 47 return self.root_inode.clone(); 48 } 49 } 50 51 impl KernFS { 52 pub const MAX_NAMELEN: usize = 4096; 53 54 #[allow(dead_code)] 55 pub fn new() -> Arc<Self> { 56 let root_inode = Self::create_root_inode(); 57 let fs = Arc::new(Self { 58 root_inode: root_inode.clone(), 59 }); 60 61 { 62 let ptr = root_inode.as_ref() as *const KernFSInode as *mut KernFSInode; 63 unsafe { 64 (*ptr).self_ref = Arc::downgrade(&root_inode); 65 } 66 } 67 root_inode.inner.write().parent = Arc::downgrade(&root_inode); 68 *root_inode.fs.write() = Arc::downgrade(&fs); 69 return fs; 70 } 71 72 fn create_root_inode() -> Arc<KernFSInode> { 73 let metadata = Metadata { 74 size: 0, 75 mode: ModeType::from_bits_truncate(0o755), 76 uid: 0, 77 gid: 0, 78 blk_size: 0, 79 blocks: 0, 80 atime: TimeSpec::new(0, 0), 81 mtime: TimeSpec::new(0, 0), 82 ctime: TimeSpec::new(0, 0), 83 dev_id: 0, 84 inode_id: generate_inode_id(), 85 file_type: FileType::Dir, 86 nlinks: 1, 87 raw_dev: 0, 88 }; 89 let root_inode = Arc::new(KernFSInode { 90 name: String::from(""), 91 inner: RwLock::new(InnerKernFSInode { 92 parent: Weak::new(), 93 metadata, 94 symlink_target: None, 95 symlink_target_absolute_path: None, 96 }), 97 self_ref: Weak::new(), 98 fs: RwLock::new(Weak::new()), 99 private_data: SpinLock::new(None), 100 callback: None, 101 children: SpinLock::new(HashMap::new()), 102 inode_type: KernInodeType::Dir, 103 }); 104 105 return root_inode; 106 } 107 } 108 109 #[derive(Debug)] 110 pub struct KernFSInode { 111 inner: RwLock<InnerKernFSInode>, 112 /// 指向当前Inode所属的文件系统的弱引用 113 fs: RwLock<Weak<KernFS>>, 114 /// 指向自身的弱引用 115 self_ref: Weak<KernFSInode>, 116 /// 私有数据 117 private_data: SpinLock<Option<KernInodePrivateData>>, 118 /// 回调函数 119 callback: Option<&'static dyn KernFSCallback>, 120 /// 子Inode 121 children: SpinLock<HashMap<String, Arc<KernFSInode>>>, 122 /// Inode类型 123 inode_type: KernInodeType, 124 /// Inode名称 125 name: String, 126 } 127 128 #[derive(Debug)] 129 pub struct InnerKernFSInode { 130 parent: Weak<KernFSInode>, 131 132 /// 当前inode的元数据 133 metadata: Metadata, 134 /// 符号链接指向的inode（仅当inode_type为SymLink时有效） 135 symlink_target: Option<Weak<KernFSInode>>, 136 symlink_target_absolute_path: Option<String>, 137 } 138 139 impl IndexNode for KernFSInode { 140 fn as_any_ref(&self) -> &dyn core::any::Any { 141 self 142 } 143 144 fn open(&self, _data: &mut FilePrivateData, _mode: &FileMode) -> Result<(), SystemError> { 145 if let Some(callback) = self.callback { 146 let callback_data = 147 KernCallbackData::new(self.self_ref.upgrade().unwrap(), self.private_data.lock()); 148 return callback.open(callback_data); 149 } 150 151 return Ok(()); 152 } 153 154 fn close(&self, _data: &mut FilePrivateData) -> Result<(), SystemError> { 155 return Ok(()); 156 } 157 158 fn metadata(&self) -> Result<Metadata, SystemError> { 159 return Ok(self.inner.read().metadata.clone()); 160 } 161 162 fn set_metadata(&self, _metadata: &Metadata) -> Result<(), SystemError> { 163 // 若文件系统没有实现此方法，则返回“不支持” 164 return Err(SystemError::EOPNOTSUPP_OR_ENOTSUP); 165 } 166 167 fn resize(&self, _len: usize) -> Result<(), SystemError> { 168 return Ok(()); 169 } 170 171 fn create_with_data( 172 &self, 173 _name: &str, 174 _file_type: FileType, 175 _mode: ModeType, 176 _data: usize, 177 ) -> Result<Arc<dyn IndexNode>, SystemError> { 178 // 应当通过kernfs的其它方法来创建文件，而不能从用户态直接调用此方法。 179 return Err(SystemError::EOPNOTSUPP_OR_ENOTSUP); 180 } 181 182 fn link(&self, _name: &str, _other: &Arc<dyn IndexNode>) -> Result<(), SystemError> { 183 // 应当通过kernfs的其它方法来操作文件，而不能从用户态直接调用此方法。 184 return Err(SystemError::EOPNOTSUPP_OR_ENOTSUP); 185 } 186 187 fn unlink(&self, _name: &str) -> Result<(), SystemError> { 188 // 应当通过kernfs的其它方法来操作文件，而不能从用户态直接调用此方法。 189 return Err(SystemError::EOPNOTSUPP_OR_ENOTSUP); 190 } 191 192 fn rmdir(&self, _name: &str) -> Result<(), SystemError> { 193 // 应当通过kernfs的其它方法来操作文件，而不能从用户态直接调用此方法。 194 return Err(SystemError::EOPNOTSUPP_OR_ENOTSUP); 195 } 196 197 fn move_( 198 &self, 199 _old_name: &str, 200 _target: &Arc<dyn IndexNode>, 201 _new_name: &str, 202 ) -> Result<(), SystemError> { 203 // 应当通过kernfs的其它方法来操作文件，而不能从用户态直接调用此方法。 204 return Err(SystemError::EOPNOTSUPP_OR_ENOTSUP); 205 } 206 207 fn find(&self, name: &str) -> Result<Arc<dyn IndexNode>, SystemError> { 208 if unlikely(name.len() > KernFS::MAX_NAMELEN) { 209 return Err(SystemError::ENAMETOOLONG); 210 } 211 if unlikely(self.inode_type != KernInodeType::Dir) { 212 return Err(SystemError::ENOTDIR); 213 } 214 match name { 215 "" | "." => { 216 return Ok(self.self_ref.upgrade().ok_or(SystemError::ENOENT)?); 217 } 218 219 ".." => { 220 return Ok(self 221 .inner 222 .read() 223 .parent 224 .upgrade() 225 .ok_or(SystemError::ENOENT)?); 226 } 227 name => { 228 // 在子目录项中查找 229 return Ok(self 230 .children 231 .lock() 232 .get(name) 233 .ok_or(SystemError::ENOENT)? 234 .clone()); 235 } 236 } 237 } 238 239 fn get_entry_name(&self, ino: InodeId) -> Result<String, SystemError> { 240 if self.inode_type != KernInodeType::Dir { 241 return Err(SystemError::ENOTDIR); 242 } 243 244 let children = self.children.lock(); 245 let r = children 246 .iter() 247 .find(|(_, v)| v.metadata().unwrap().inode_id == ino) 248 .map(|(k, _)| k.clone()); 249 250 return r.ok_or(SystemError::ENOENT); 251 } 252 253 fn get_entry_name_and_metadata(&self, ino: InodeId) -> Result<(String, Metadata), SystemError> { 254 // 如果有条件，请在文件系统中使用高效的方式实现本接口，而不是依赖这个低效率的默认实现。 255 let name = self.get_entry_name(ino)?; 256 let entry = self.find(&name)?; 257 return Ok((name, entry.metadata()?)); 258 } 259 260 fn ioctl(&self, _cmd: u32, _data: usize) -> Result<usize, SystemError> { 261 // 若文件系统没有实现此方法，则返回“不支持” 262 return Err(SystemError::EOPNOTSUPP_OR_ENOTSUP); 263 } 264 265 fn truncate(&self, _len: usize) -> Result<(), SystemError> { 266 // 应当通过kernfs的其它方法来操作文件，而不能从用户态直接调用此方法。 267 return Err(SystemError::EOPNOTSUPP_OR_ENOTSUP); 268 } 269 270 fn sync(&self) -> Result<(), SystemError> { 271 return Ok(()); 272 } 273 274 fn fs(&self) -> Arc<dyn FileSystem> { 275 return self.fs.read().upgrade().unwrap(); 276 } 277 278 fn list(&self) -> Result<Vec<String>, SystemError> { 279 let info = self.metadata()?; 280 if info.file_type != FileType::Dir { 281 return Err(SystemError::ENOTDIR); 282 } 283 284 let mut keys: Vec<String> = Vec::new(); 285 keys.push(String::from(".")); 286 keys.push(String::from("..")); 287 self.children 288 .lock() 289 .keys() 290 .into_iter() 291 .for_each(|x| keys.push(x.clone())); 292 293 return Ok(keys); 294 } 295 296 fn read_at( 297 &self, 298 offset: usize, 299 len: usize, 300 buf: &mut [u8], 301 _data: &mut FilePrivateData, 302 ) -> Result<usize, SystemError> { 303 if self.inode_type == KernInodeType::SymLink { 304 let inner = self.inner.read(); 305 if offset >= inner.symlink_target_absolute_path.as_ref().unwrap().len() { 306 return Ok(0); 307 } 308 let len = min(len, buf.len()); 309 let len = min( 310 len, 311 inner.symlink_target_absolute_path.as_ref().unwrap().len() - offset, 312 ); 313 buf[0..len].copy_from_slice( 314 &inner 315 .symlink_target_absolute_path 316 .as_ref() 317 .unwrap() 318 .as_bytes()[offset..offset + len], 319 ); 320 return Ok(len); 321 } 322 if self.inode_type != KernInodeType::File { 323 return Err(SystemError::EISDIR); 324 } 325 326 if self.callback.is_none() { 327 kwarn!("kernfs: callback is none"); 328 return Err(SystemError::EOPNOTSUPP_OR_ENOTSUP); 329 } 330 331 let callback_data = 332 KernCallbackData::new(self.self_ref.upgrade().unwrap(), self.private_data.lock()); 333 return self 334 .callback 335 .as_ref() 336 .unwrap() 337 .read(callback_data, &mut buf[..len], offset); 338 } 339 340 fn write_at( 341 &self, 342 offset: usize, 343 len: usize, 344 buf: &[u8], 345 _data: &mut FilePrivateData, 346 ) -> Result<usize, SystemError> { 347 if self.inode_type != KernInodeType::File { 348 return Err(SystemError::EISDIR); 349 } 350 351 if self.callback.is_none() { 352 return Err(SystemError::EOPNOTSUPP_OR_ENOTSUP); 353 } 354 355 let callback_data = 356 KernCallbackData::new(self.self_ref.upgrade().unwrap(), self.private_data.lock()); 357 return self 358 .callback 359 .as_ref() 360 .unwrap() 361 .write(callback_data, &buf[..len], offset); 362 } 363 } 364 365 impl KernFSInode { 366 pub fn new( 367 parent: Option<Arc<KernFSInode>>, 368 name: String, 369 mut metadata: Metadata, 370 inode_type: KernInodeType, 371 private_data: Option<KernInodePrivateData>, 372 callback: Option<&'static dyn KernFSCallback>, 373 ) -> Arc<KernFSInode> { 374 metadata.file_type = inode_type.into(); 375 let parent: Weak<KernFSInode> = parent.map(|x| Arc::downgrade(&x)).unwrap_or_default(); 376 377 let inode = Arc::new(KernFSInode { 378 name, 379 inner: RwLock::new(InnerKernFSInode { 380 parent: parent.clone(), 381 metadata, 382 symlink_target: None, 383 symlink_target_absolute_path: None, 384 }), 385 self_ref: Weak::new(), 386 fs: RwLock::new(Weak::new()), 387 private_data: SpinLock::new(private_data), 388 callback, 389 children: SpinLock::new(HashMap::new()), 390 inode_type, 391 }); 392 393 { 394 let ptr = inode.as_ref() as *const KernFSInode as *mut KernFSInode; 395 unsafe { 396 (*ptr).self_ref = Arc::downgrade(&inode); 397 } 398 } 399 if parent.strong_count() > 0 { 400 let kernfs = parent 401 .upgrade() 402 .unwrap() 403 .fs() 404 .downcast_arc::<KernFS>() 405 .expect("KernFSInode::new: parent is not a KernFS instance"); 406 *inode.fs.write() = Arc::downgrade(&kernfs); 407 } 408 return inode; 409 } 410 411 /// 在当前inode下增加子目录 412 /// 413 /// ## 参数 414 /// 415 /// - `name`：子目录名称 416 /// - `mode`：子目录权限 417 /// - `private_data`：子目录私有数据 418 /// - `callback`：子目录回调函数 419 /// 420 /// ## 返回值 421 /// 422 /// - 成功：子目录inode 423 /// - 失败：错误码 424 #[allow(dead_code)] 425 #[inline] 426 pub fn add_dir( 427 &self, 428 name: String, 429 mode: ModeType, 430 private_data: Option<KernInodePrivateData>, 431 callback: Option<&'static dyn KernFSCallback>, 432 ) -> Result<Arc<KernFSInode>, SystemError> { 433 if unlikely(self.inode_type != KernInodeType::Dir) { 434 return Err(SystemError::ENOTDIR); 435 } 436 437 return self.inner_create(name, KernInodeType::Dir, mode, 0, private_data, callback); 438 } 439 440 /// 在当前inode下增加文件 441 /// 442 /// ## 参数 443 /// 444 /// - `name`：文件名称 445 /// - `mode`：文件权限 446 /// - `size`：文件大小(如果不指定，则默认为4096) 447 /// - `private_data`：文件私有数据 448 /// - `callback`：文件回调函数 449 /// 450 /// 451 /// ## 返回值 452 /// 453 /// - 成功：文件inode 454 /// - 失败：错误码 455 #[allow(dead_code)] 456 #[inline] 457 pub fn add_file( 458 &self, 459 name: String, 460 mode: ModeType, 461 size: Option<usize>, 462 private_data: Option<KernInodePrivateData>, 463 callback: Option<&'static dyn KernFSCallback>, 464 ) -> Result<Arc<KernFSInode>, SystemError> { 465 if unlikely(self.inode_type != KernInodeType::Dir) { 466 return Err(SystemError::ENOTDIR); 467 } 468 469 let size = size.unwrap_or(4096); 470 return self.inner_create( 471 name, 472 KernInodeType::File, 473 mode, 474 size, 475 private_data, 476 callback, 477 ); 478 } 479 480 fn inner_create( 481 &self, 482 name: String, 483 file_type: KernInodeType, 484 mode: ModeType, 485 mut size: usize, 486 private_data: Option<KernInodePrivateData>, 487 callback: Option<&'static dyn KernFSCallback>, 488 ) -> Result<Arc<KernFSInode>, SystemError> { 489 match file_type { 490 KernInodeType::Dir | KernInodeType::SymLink => { 491 size = 0; 492 } 493 _ => {} 494 } 495 496 let metadata = Metadata { 497 size: size as i64, 498 mode, 499 uid: 0, 500 gid: 0, 501 blk_size: 0, 502 blocks: 0, 503 atime: TimeSpec::new(0, 0), 504 mtime: TimeSpec::new(0, 0), 505 ctime: TimeSpec::new(0, 0), 506 dev_id: 0, 507 inode_id: generate_inode_id(), 508 file_type: file_type.into(), 509 nlinks: 1, 510 raw_dev: 0, 511 }; 512 513 let new_inode: Arc<KernFSInode> = Self::new( 514 Some(self.self_ref.upgrade().unwrap()), 515 name.clone(), 516 metadata, 517 file_type, 518 private_data, 519 callback, 520 ); 521 522 self.children.lock().insert(name, new_inode.clone()); 523 524 return Ok(new_inode); 525 } 526 527 /// 在当前inode下删除子目录或者文件 528 /// 529 /// 如果要删除的是子目录，且子目录不为空，则返回ENOTEMPTY 530 /// 531 /// ## 参数 532 /// 533 /// - `name`：子目录或者文件名称 534 /// 535 /// ## 返回值 536 /// 537 /// - 成功：() 538 /// - 失败：错误码 539 #[allow(dead_code)] 540 pub fn remove(&self, name: &str) -> Result<(), SystemError> { 541 if unlikely(self.inode_type != KernInodeType::Dir) { 542 return Err(SystemError::ENOTDIR); 543 } 544 545 let mut children = self.children.lock(); 546 let inode = children.get(name).ok_or(SystemError::ENOENT)?; 547 if inode.children.lock().is_empty() { 548 children.remove(name); 549 return Ok(()); 550 } else { 551 return Err(SystemError::ENOTEMPTY); 552 } 553 } 554 555 /// add_link - create a symlink in kernfs 556 /// 557 /// ## 参数 558 /// 559 /// - `parent`: directory to create the symlink in 560 /// - `name`: name of the symlink 561 /// - `target`: target node for the symlink to point to 562 /// 563 /// Returns the created node on success 564 /// 565 /// 参考 https://code.dragonos.org.cn/xref/linux-6.1.9/fs/kernfs/symlink.c#25 566 pub fn add_link( 567 &self, 568 name: String, 569 target: &Arc<KernFSInode>, 570 target_absolute_path: String, 571 ) -> Result<Arc<KernFSInode>, SystemError> { 572 // kdebug!("kernfs add link: name:{name}, target path={target_absolute_path}"); 573 let inode = self.inner_create( 574 name, 575 KernInodeType::SymLink, 576 ModeType::S_IFLNK | ModeType::from_bits_truncate(0o777), 577 0, 578 None, 579 None, 580 )?; 581 582 inode.inner.write().symlink_target = Some(Arc::downgrade(target)); 583 inode.inner.write().symlink_target_absolute_path = Some(target_absolute_path); 584 return Ok(inode); 585 } 586 587 pub fn name(&self) -> &str { 588 return &self.name; 589 } 590 591 pub fn parent(&self) -> Option<Arc<KernFSInode>> { 592 return self.inner.read().parent.upgrade(); 593 } 594 595 pub fn private_data_mut(&self) -> SpinLockGuard<Option<KernInodePrivateData>> { 596 return self.private_data.lock(); 597 } 598 599 #[allow(dead_code)] 600 pub fn symlink_target(&self) -> Option<Arc<KernFSInode>> { 601 return self.inner.read().symlink_target.as_ref()?.upgrade(); 602 } 603 604 /// remove a kernfs_node recursively 605 pub fn remove_recursive(&self) { 606 let mut children = self.children.lock().drain().collect::<Vec<_>>(); 607 while let Some((_, child)) = children.pop() { 608 children.append(&mut child.children.lock().drain().collect::<Vec<_>>()); 609 } 610 } 611 612 /// 删除当前的inode（包括其自身、子目录和子文件） 613 #[allow(dead_code)] 614 pub fn remove_inode_include_self(&self) { 615 let parent = self.parent(); 616 if let Some(parent) = parent { 617 parent.children.lock().remove(self.name()); 618 } 619 self.remove_recursive(); 620 } 621 } 622 #[derive(Debug, Clone, Copy, PartialEq, Eq)] 623 pub enum KernInodeType { 624 Dir, 625 File, 626 SymLink, 627 } 628 629 impl Into<FileType> for KernInodeType { 630 fn into(self) -> FileType { 631 match self { 632 KernInodeType::Dir => FileType::Dir, 633 KernInodeType::File => FileType::File, 634 KernInodeType::SymLink => FileType::SymLink, 635 } 636 } 637 } 638