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 driver::base::device::device_number::DeviceNumber, 13 libs::{ 14 casting::DowncastArc, 15 rwlock::RwLock, 16 spinlock::{SpinLock, SpinLockGuard}, 17 }, 18 time::TimeSpec, 19 }; 20 21 use self::callback::{KernCallbackData, KernFSCallback, KernInodePrivateData}; 22 23 use super::vfs::{ 24 core::generate_inode_id, file::FileMode, syscall::ModeType, FilePrivateData, FileSystem, 25 FileType, FsInfo, IndexNode, InodeId, Metadata, 26 }; 27 28 pub mod callback; 29 30 #[derive(Debug)] 31 pub struct KernFS { 32 root_inode: Arc<KernFSInode>, 33 } 34 35 impl FileSystem for KernFS { 36 fn as_any_ref(&self) -> &dyn core::any::Any { 37 self 38 } 39 40 fn info(&self) -> FsInfo { 41 return FsInfo { 42 blk_dev_id: 0, 43 max_name_len: KernFS::MAX_NAMELEN, 44 }; 45 } 46 47 fn root_inode(&self) -> Arc<dyn IndexNode> { 48 return self.root_inode.clone(); 49 } 50 51 fn name(&self) -> &str { 52 "kernfs" 53 } 54 } 55 56 impl KernFS { 57 pub const MAX_NAMELEN: usize = 4096; 58 59 #[allow(dead_code)] 60 pub fn new() -> Arc<Self> { 61 let root_inode = Self::create_root_inode(); 62 let fs = Arc::new(Self { 63 root_inode: root_inode.clone(), 64 }); 65 66 { 67 let ptr = root_inode.as_ref() as *const KernFSInode as *mut KernFSInode; 68 unsafe { 69 (*ptr).self_ref = Arc::downgrade(&root_inode); 70 } 71 } 72 root_inode.inner.write().parent = Arc::downgrade(&root_inode); 73 *root_inode.fs.write() = Arc::downgrade(&fs); 74 return fs; 75 } 76 77 fn create_root_inode() -> Arc<KernFSInode> { 78 let metadata = Metadata { 79 size: 0, 80 mode: ModeType::from_bits_truncate(0o755), 81 uid: 0, 82 gid: 0, 83 blk_size: 0, 84 blocks: 0, 85 atime: TimeSpec::new(0, 0), 86 mtime: TimeSpec::new(0, 0), 87 ctime: TimeSpec::new(0, 0), 88 dev_id: 0, 89 inode_id: generate_inode_id(), 90 file_type: FileType::Dir, 91 nlinks: 1, 92 raw_dev: DeviceNumber::default(), 93 }; 94 let root_inode = Arc::new(KernFSInode { 95 name: String::from(""), 96 inner: RwLock::new(InnerKernFSInode { 97 parent: Weak::new(), 98 metadata, 99 symlink_target: None, 100 symlink_target_absolute_path: None, 101 }), 102 self_ref: Weak::new(), 103 fs: RwLock::new(Weak::new()), 104 private_data: SpinLock::new(None), 105 callback: None, 106 children: SpinLock::new(HashMap::new()), 107 inode_type: KernInodeType::Dir, 108 }); 109 110 return root_inode; 111 } 112 } 113 114 #[derive(Debug)] 115 pub struct KernFSInode { 116 inner: RwLock<InnerKernFSInode>, 117 /// 指向当前Inode所属的文件系统的弱引用 118 fs: RwLock<Weak<KernFS>>, 119 /// 指向自身的弱引用 120 self_ref: Weak<KernFSInode>, 121 /// 私有数据 122 private_data: SpinLock<Option<KernInodePrivateData>>, 123 /// 回调函数 124 callback: Option<&'static dyn KernFSCallback>, 125 /// 子Inode 126 children: SpinLock<HashMap<String, Arc<KernFSInode>>>, 127 /// Inode类型 128 inode_type: KernInodeType, 129 /// Inode名称 130 name: String, 131 } 132 133 #[derive(Debug)] 134 pub struct InnerKernFSInode { 135 parent: Weak<KernFSInode>, 136 137 /// 当前inode的元数据 138 metadata: Metadata, 139 /// 符号链接指向的inode（仅当inode_type为SymLink时有效） 140 symlink_target: Option<Weak<KernFSInode>>, 141 symlink_target_absolute_path: Option<String>, 142 } 143 144 impl IndexNode for KernFSInode { 145 fn as_any_ref(&self) -> &dyn core::any::Any { 146 self 147 } 148 149 fn open(&self, _data: &mut FilePrivateData, _mode: &FileMode) -> Result<(), SystemError> { 150 if let Some(callback) = self.callback { 151 let callback_data = 152 KernCallbackData::new(self.self_ref.upgrade().unwrap(), self.private_data.lock()); 153 return callback.open(callback_data); 154 } 155 156 return Ok(()); 157 } 158 159 fn close(&self, _data: &mut FilePrivateData) -> Result<(), SystemError> { 160 return Ok(()); 161 } 162 163 fn metadata(&self) -> Result<Metadata, SystemError> { 164 return Ok(self.inner.read().metadata.clone()); 165 } 166 167 fn set_metadata(&self, _metadata: &Metadata) -> Result<(), SystemError> { 168 // 若文件系统没有实现此方法，则返回“不支持” 169 return Err(SystemError::EOPNOTSUPP_OR_ENOTSUP); 170 } 171 172 fn resize(&self, _len: usize) -> Result<(), SystemError> { 173 return Ok(()); 174 } 175 176 fn create_with_data( 177 &self, 178 _name: &str, 179 _file_type: FileType, 180 _mode: ModeType, 181 _data: usize, 182 ) -> Result<Arc<dyn IndexNode>, SystemError> { 183 // 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。 184 return Err(SystemError::EOPNOTSUPP_OR_ENOTSUP); 185 } 186 187 fn link(&self, _name: &str, _other: &Arc<dyn IndexNode>) -> 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 unlink(&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 rmdir(&self, _name: &str) -> Result<(), SystemError> { 198 // 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。 199 return Err(SystemError::EOPNOTSUPP_OR_ENOTSUP); 200 } 201 202 fn move_to( 203 &self, 204 _old_name: &str, 205 _target: &Arc<dyn IndexNode>, 206 _new_name: &str, 207 ) -> Result<(), SystemError> { 208 // 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。 209 return Err(SystemError::EOPNOTSUPP_OR_ENOTSUP); 210 } 211 212 fn find(&self, name: &str) -> Result<Arc<dyn IndexNode>, SystemError> { 213 if unlikely(name.len() > KernFS::MAX_NAMELEN) { 214 return Err(SystemError::ENAMETOOLONG); 215 } 216 if unlikely(self.inode_type != KernInodeType::Dir) { 217 return Err(SystemError::ENOTDIR); 218 } 219 match name { 220 "" | "." => { 221 return Ok(self.self_ref.upgrade().ok_or(SystemError::ENOENT)?); 222 } 223 224 ".." => { 225 return Ok(self 226 .inner 227 .read() 228 .parent 229 .upgrade() 230 .ok_or(SystemError::ENOENT)?); 231 } 232 name => { 233 // 在子目录项中查找 234 return Ok(self 235 .children 236 .lock() 237 .get(name) 238 .ok_or(SystemError::ENOENT)? 239 .clone()); 240 } 241 } 242 } 243 244 fn get_entry_name(&self, ino: InodeId) -> Result<String, SystemError> { 245 if self.inode_type != KernInodeType::Dir { 246 return Err(SystemError::ENOTDIR); 247 } 248 249 let children = self.children.lock(); 250 let r = children 251 .iter() 252 .find(|(_, v)| v.metadata().unwrap().inode_id == ino) 253 .map(|(k, _)| k.clone()); 254 255 return r.ok_or(SystemError::ENOENT); 256 } 257 258 fn get_entry_name_and_metadata(&self, ino: InodeId) -> Result<(String, Metadata), SystemError> { 259 // 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。 260 let name = self.get_entry_name(ino)?; 261 let entry = self.find(&name)?; 262 return Ok((name, entry.metadata()?)); 263 } 264 265 fn ioctl( 266 &self, 267 _cmd: u32, 268 _data: usize, 269 _private_data: &FilePrivateData, 270 ) -> Result<usize, SystemError> { 271 // 若文件系统没有实现此方法，则返回“不支持” 272 return Err(SystemError::EOPNOTSUPP_OR_ENOTSUP); 273 } 274 275 fn truncate(&self, _len: usize) -> Result<(), SystemError> { 276 // 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。 277 return Err(SystemError::EOPNOTSUPP_OR_ENOTSUP); 278 } 279 280 fn sync(&self) -> Result<(), SystemError> { 281 return Ok(()); 282 } 283 284 fn fs(&self) -> Arc<dyn FileSystem> { 285 return self.fs.read().upgrade().unwrap(); 286 } 287 288 fn list(&self) -> Result<Vec<String>, SystemError> { 289 let info = self.metadata()?; 290 if info.file_type != FileType::Dir { 291 return Err(SystemError::ENOTDIR); 292 } 293 294 let mut keys: Vec<String> = Vec::new(); 295 keys.push(String::from(".")); 296 keys.push(String::from("..")); 297 self.children 298 .lock() 299 .keys() 300 .for_each(|x| keys.push(x.clone())); 301 302 return Ok(keys); 303 } 304 305 fn read_at( 306 &self, 307 offset: usize, 308 len: usize, 309 buf: &mut [u8], 310 _data: &mut FilePrivateData, 311 ) -> Result<usize, SystemError> { 312 if self.inode_type == KernInodeType::SymLink { 313 let inner = self.inner.read(); 314 if offset >= inner.symlink_target_absolute_path.as_ref().unwrap().len() { 315 return Ok(0); 316 } 317 let len = min(len, buf.len()); 318 let len = min( 319 len, 320 inner.symlink_target_absolute_path.as_ref().unwrap().len() - offset, 321 ); 322 buf[0..len].copy_from_slice( 323 &inner 324 .symlink_target_absolute_path 325 .as_ref() 326 .unwrap() 327 .as_bytes()[offset..offset + len], 328 ); 329 return Ok(len); 330 } 331 if self.inode_type != KernInodeType::File { 332 return Err(SystemError::EISDIR); 333 } 334 335 if self.callback.is_none() { 336 kwarn!("kernfs: callback is none"); 337 return Err(SystemError::EOPNOTSUPP_OR_ENOTSUP); 338 } 339 340 let callback_data = 341 KernCallbackData::new(self.self_ref.upgrade().unwrap(), self.private_data.lock()); 342 return self 343 .callback 344 .as_ref() 345 .unwrap() 346 .read(callback_data, &mut buf[..len], offset); 347 } 348 349 fn write_at( 350 &self, 351 offset: usize, 352 len: usize, 353 buf: &[u8], 354 _data: &mut FilePrivateData, 355 ) -> Result<usize, SystemError> { 356 if self.inode_type != KernInodeType::File { 357 return Err(SystemError::EISDIR); 358 } 359 360 if self.callback.is_none() { 361 return Err(SystemError::EOPNOTSUPP_OR_ENOTSUP); 362 } 363 364 let callback_data = 365 KernCallbackData::new(self.self_ref.upgrade().unwrap(), self.private_data.lock()); 366 return self 367 .callback 368 .as_ref() 369 .unwrap() 370 .write(callback_data, &buf[..len], offset); 371 } 372 373 fn rename(&self, _old_name: &str, _new_name: &str) -> Result<(), SystemError> { 374 // 待实现 375 Err(SystemError::ENOSYS) 376 } 377 } 378 379 impl KernFSInode { 380 pub fn new( 381 parent: Option<Arc<KernFSInode>>, 382 name: String, 383 mut metadata: Metadata, 384 inode_type: KernInodeType, 385 private_data: Option<KernInodePrivateData>, 386 callback: Option<&'static dyn KernFSCallback>, 387 ) -> Arc<KernFSInode> { 388 metadata.file_type = inode_type.into(); 389 let parent: Weak<KernFSInode> = parent.map(|x| Arc::downgrade(&x)).unwrap_or_default(); 390 391 let inode = Arc::new(KernFSInode { 392 name, 393 inner: RwLock::new(InnerKernFSInode { 394 parent: parent.clone(), 395 metadata, 396 symlink_target: None, 397 symlink_target_absolute_path: None, 398 }), 399 self_ref: Weak::new(), 400 fs: RwLock::new(Weak::new()), 401 private_data: SpinLock::new(private_data), 402 callback, 403 children: SpinLock::new(HashMap::new()), 404 inode_type, 405 }); 406 407 { 408 let ptr = inode.as_ref() as *const KernFSInode as *mut KernFSInode; 409 unsafe { 410 (*ptr).self_ref = Arc::downgrade(&inode); 411 } 412 } 413 if parent.strong_count() > 0 { 414 let kernfs = parent 415 .upgrade() 416 .unwrap() 417 .fs() 418 .downcast_arc::<KernFS>() 419 .expect("KernFSInode::new: parent is not a KernFS instance"); 420 *inode.fs.write() = Arc::downgrade(&kernfs); 421 } 422 return inode; 423 } 424 425 /// 在当前inode下增加子目录 426 /// 427 /// ## 参数 428 /// 429 /// - `name`：子目录名称 430 /// - `mode`：子目录权限 431 /// - `private_data`：子目录私有数据 432 /// - `callback`：子目录回调函数 433 /// 434 /// ## 返回值 435 /// 436 /// - 成功：子目录inode 437 /// - 失败：错误码 438 #[allow(dead_code)] 439 #[inline] 440 pub fn add_dir( 441 &self, 442 name: String, 443 mode: ModeType, 444 private_data: Option<KernInodePrivateData>, 445 callback: Option<&'static dyn KernFSCallback>, 446 ) -> Result<Arc<KernFSInode>, SystemError> { 447 if unlikely(self.inode_type != KernInodeType::Dir) { 448 return Err(SystemError::ENOTDIR); 449 } 450 451 return self.inner_create(name, KernInodeType::Dir, mode, 0, private_data, callback); 452 } 453 454 /// 在当前inode下增加文件 455 /// 456 /// ## 参数 457 /// 458 /// - `name`：文件名称 459 /// - `mode`：文件权限 460 /// - `size`：文件大小(如果不指定，则默认为4096) 461 /// - `private_data`：文件私有数据 462 /// - `callback`：文件回调函数 463 /// 464 /// 465 /// ## 返回值 466 /// 467 /// - 成功：文件inode 468 /// - 失败：错误码 469 #[allow(dead_code)] 470 #[inline] 471 pub fn add_file( 472 &self, 473 name: String, 474 mode: ModeType, 475 size: Option<usize>, 476 private_data: Option<KernInodePrivateData>, 477 callback: Option<&'static dyn KernFSCallback>, 478 ) -> Result<Arc<KernFSInode>, SystemError> { 479 if unlikely(self.inode_type != KernInodeType::Dir) { 480 return Err(SystemError::ENOTDIR); 481 } 482 483 let size = size.unwrap_or(4096); 484 return self.inner_create( 485 name, 486 KernInodeType::File, 487 mode, 488 size, 489 private_data, 490 callback, 491 ); 492 } 493 494 fn inner_create( 495 &self, 496 name: String, 497 file_type: KernInodeType, 498 mode: ModeType, 499 mut size: usize, 500 private_data: Option<KernInodePrivateData>, 501 callback: Option<&'static dyn KernFSCallback>, 502 ) -> Result<Arc<KernFSInode>, SystemError> { 503 match file_type { 504 KernInodeType::Dir | KernInodeType::SymLink => { 505 size = 0; 506 } 507 _ => {} 508 } 509 510 let metadata = Metadata { 511 size: size as i64, 512 mode, 513 uid: 0, 514 gid: 0, 515 blk_size: 0, 516 blocks: 0, 517 atime: TimeSpec::new(0, 0), 518 mtime: TimeSpec::new(0, 0), 519 ctime: TimeSpec::new(0, 0), 520 dev_id: 0, 521 inode_id: generate_inode_id(), 522 file_type: file_type.into(), 523 nlinks: 1, 524 raw_dev: DeviceNumber::default(), 525 }; 526 527 let new_inode: Arc<KernFSInode> = Self::new( 528 Some(self.self_ref.upgrade().unwrap()), 529 name.clone(), 530 metadata, 531 file_type, 532 private_data, 533 callback, 534 ); 535 536 self.children.lock().insert(name, new_inode.clone()); 537 538 return Ok(new_inode); 539 } 540 541 /// 在当前inode下删除子目录或者文件 542 /// 543 /// 如果要删除的是子目录，且子目录不为空，则返回ENOTEMPTY 544 /// 545 /// ## 参数 546 /// 547 /// - `name`：子目录或者文件名称 548 /// 549 /// ## 返回值 550 /// 551 /// - 成功：() 552 /// - 失败：错误码 553 #[allow(dead_code)] 554 pub fn remove(&self, name: &str) -> Result<(), SystemError> { 555 if unlikely(self.inode_type != KernInodeType::Dir) { 556 return Err(SystemError::ENOTDIR); 557 } 558 559 let mut children = self.children.lock(); 560 let inode = children.get(name).ok_or(SystemError::ENOENT)?; 561 if inode.children.lock().is_empty() { 562 children.remove(name); 563 return Ok(()); 564 } else { 565 return Err(SystemError::ENOTEMPTY); 566 } 567 } 568 569 /// add_link - create a symlink in kernfs 570 /// 571 /// ## 参数 572 /// 573 /// - `parent`: directory to create the symlink in 574 /// - `name`: name of the symlink 575 /// - `target`: target node for the symlink to point to 576 /// 577 /// Returns the created node on success 578 /// 579 /// 参考 https://code.dragonos.org.cn/xref/linux-6.1.9/fs/kernfs/symlink.c#25 580 pub fn add_link( 581 &self, 582 name: String, 583 target: &Arc<KernFSInode>, 584 target_absolute_path: String, 585 ) -> Result<Arc<KernFSInode>, SystemError> { 586 // kdebug!("kernfs add link: name:{name}, target path={target_absolute_path}"); 587 let inode = self.inner_create( 588 name, 589 KernInodeType::SymLink, 590 ModeType::S_IFLNK | ModeType::from_bits_truncate(0o777), 591 0, 592 None, 593 None, 594 )?; 595 596 inode.inner.write().symlink_target = Some(Arc::downgrade(target)); 597 inode.inner.write().symlink_target_absolute_path = Some(target_absolute_path); 598 return Ok(inode); 599 } 600 601 pub fn name(&self) -> &str { 602 return &self.name; 603 } 604 605 pub fn parent(&self) -> Option<Arc<KernFSInode>> { 606 return self.inner.read().parent.upgrade(); 607 } 608 609 pub fn private_data_mut(&self) -> SpinLockGuard<Option<KernInodePrivateData>> { 610 return self.private_data.lock(); 611 } 612 613 #[allow(dead_code)] 614 pub fn symlink_target(&self) -> Option<Arc<KernFSInode>> { 615 return self.inner.read().symlink_target.as_ref()?.upgrade(); 616 } 617 618 /// remove a kernfs_node recursively 619 pub fn remove_recursive(&self) { 620 let mut children = self.children.lock().drain().collect::<Vec<_>>(); 621 while let Some((_, child)) = children.pop() { 622 children.append(&mut child.children.lock().drain().collect::<Vec<_>>()); 623 } 624 } 625 626 /// 删除当前的inode（包括其自身、子目录和子文件） 627 #[allow(dead_code)] 628 pub fn remove_inode_include_self(&self) { 629 let parent = self.parent(); 630 if let Some(parent) = parent { 631 parent.children.lock().remove(self.name()); 632 } 633 self.remove_recursive(); 634 } 635 } 636 #[derive(Debug, Clone, Copy, PartialEq, Eq)] 637 pub enum KernInodeType { 638 Dir, 639 File, 640 SymLink, 641 } 642 643 impl From<KernInodeType> for FileType { 644 fn from(val: KernInodeType) -> Self { 645 match val { 646 KernInodeType::Dir => FileType::Dir, 647 KernInodeType::File => FileType::File, 648 KernInodeType::SymLink => FileType::SymLink, 649 } 650 } 651 } 652