1 use crate::filesystem::vfs::file::FileMode; 2 use crate::filesystem::vfs::make_rawdev; 3 use crate::filesystem::vfs::{ 4 core::generate_inode_id, FilePrivateData, FileSystem, FileType, IndexNode, Metadata, PollStatus, 5 }; 6 use crate::{ 7 syscall::SystemError, 8 libs::spinlock::SpinLock, 9 time::TimeSpec, 10 }; 11 use alloc::{ 12 string::String, 13 sync::{Arc, Weak}, 14 vec::Vec, 15 }; 16 // use uuid::{uuid, Uuid}; 17 use super::{DevFS, DeviceINode}; 18 19 #[derive(Debug)] 20 pub struct NullInode { 21 /// uuid 暂时不知道有什么用（x 22 // uuid: Uuid, 23 /// 指向自身的弱引用 24 self_ref: Weak<LockedNullInode>, 25 /// 指向inode所在的文件系统对象的指针 26 fs: Weak<DevFS>, 27 /// INode 元数据 28 metadata: Metadata, 29 } 30 31 #[derive(Debug)] 32 pub struct LockedNullInode(SpinLock<NullInode>); 33 34 impl LockedNullInode { 35 pub fn new() -> Arc<Self> { 36 let inode = NullInode { 37 // uuid: Uuid::new_v5(), 38 self_ref: Weak::default(), 39 fs: Weak::default(), 40 metadata: Metadata { 41 dev_id: 1, 42 inode_id: generate_inode_id(), 43 size: 0, 44 blk_size: 0, 45 blocks: 0, 46 atime: TimeSpec::default(), 47 mtime: TimeSpec::default(), 48 ctime: TimeSpec::default(), 49 file_type: FileType::CharDevice, // 文件夹，block设备，char设备 50 mode: 0o666, 51 nlinks: 1, 52 uid: 0, 53 gid: 0, 54 raw_dev: make_rawdev(1, 3), // 这里用来作为device number 55 }, 56 }; 57 58 let result = Arc::new(LockedNullInode(SpinLock::new(inode))); 59 result.0.lock().self_ref = Arc::downgrade(&result); 60 61 return result; 62 } 63 } 64 65 impl DeviceINode for LockedNullInode { 66 fn set_fs(&self, fs: Weak<DevFS>) { 67 self.0.lock().fs = fs; 68 } 69 } 70 71 impl IndexNode for LockedNullInode { 72 fn as_any_ref(&self) -> &dyn core::any::Any { 73 self 74 } 75 76 fn open(&self, _data: &mut FilePrivateData, _mode: &FileMode) -> Result<(), SystemError> { 77 Err(SystemError::ENOTSUP) 78 } 79 80 fn close(&self, _data: &mut FilePrivateData) -> Result<(), SystemError> { 81 Err(SystemError::ENOTSUP) 82 } 83 84 fn metadata(&self) -> Result<Metadata, SystemError> { 85 return Ok(self.0.lock().metadata.clone()); 86 } 87 88 fn fs(&self) -> Arc<dyn FileSystem> { 89 return self.0.lock().fs.upgrade().unwrap(); 90 } 91 92 fn list(&self) -> Result<Vec<String>, SystemError> { 93 Err(SystemError::ENOTSUP) 94 } 95 96 fn set_metadata(&self, metadata: &Metadata) -> Result<(), SystemError> { 97 let mut inode = self.0.lock(); 98 inode.metadata.atime = metadata.atime; 99 inode.metadata.mtime = metadata.mtime; 100 inode.metadata.ctime = metadata.ctime; 101 inode.metadata.mode = metadata.mode; 102 inode.metadata.uid = metadata.uid; 103 inode.metadata.gid = metadata.gid; 104 105 return Ok(()); 106 } 107 108 fn poll(&self) -> Result<PollStatus, SystemError> { 109 return Ok(PollStatus { 110 flags: PollStatus::READ_MASK | PollStatus::WRITE_MASK, 111 }); 112 } 113 114 /// 读设备 - 应该调用设备的函数读写，而不是通过文件系统读写 115 fn read_at( 116 &self, 117 _offset: usize, 118 len: usize, 119 buf: &mut [u8], 120 _data: &mut FilePrivateData, 121 ) -> Result<usize, SystemError> { 122 if buf.len() < len { 123 return Err(SystemError::EINVAL); 124 } 125 126 for i in 0..len { 127 buf[i] = 0; 128 } 129 130 return Ok(len); 131 } 132 133 /// 写设备 - 应该调用设备的函数读写，而不是通过文件系统读写 134 fn write_at( 135 &self, 136 _offset: usize, 137 len: usize, 138 buf: &[u8], 139 _data: &mut FilePrivateData, 140 ) -> Result<usize, SystemError> { 141 if buf.len() < len { 142 return Err(SystemError::EINVAL); 143 } 144 145 Ok(len) 146 } 147 } 148