Expand description
Arc<Inode> -> OSInodeInner: In order to open files concurrently
we need to wrap Inode into Arc,but Mutex in Inode prevents
file systems from being accessed simultaneously
UPSafeCell<OSInodeInner> -> OSInode: for static ROOT_INODE,we
need to wrap OSInodeInner into UPSafeCell
Structs
inode in memory A wrapper around a filesystem inode to implement File trait atop
The OS inode inner in ‘UPSafeCell’
The flags argument to the open() system call is constructed by ORing together zero or more of the following values: