Please enable JavaScript.

Coggle requires JavaScript to display documents.

VFS - Coggle Diagram

- - - - ->mount
        
        return root dentry of mntpoint
      - void (kill_sb) (struct super_block );
        
        called when the fs is shutdown
    - - inode ops
        
        alloc_inode
        
        destroy_inode
        
        dirty_inode
        
        the inode itself is dirtied
        
        drop_inode
        
        lock
        
        inode->i_lock
        
        delete_inode
        
        clear_inode
        
        write_inode
        
        write inode to disc
      - sb ops
        
        sync_fs
        
        writing out all dirty data associated with a sb
        
        freeze_fs
        
        unfreeze_fs
        
        statfs
        
        remount_fs
        
        umount_begin
        
        free_cached_objects
      - lock
        
        All methods are called without any locks being held, without mentioned explicitely
      - context
        
        process
    - - create
        
        syscall
        
        open
        
        create
        
        fs
        
        regular files
      - lookup
      - link
      - unlink
      - mkdir
      - rmdir
      - rename
    - - writepage
        
        before calling
        
        PG_Dirty is cleared
        
        PageLocked is true
        
        start writeout
        
        PG_Writeback is set
        
        done
        
        page is unlocked
      - writepages
      - readpage
      - readpages
      - readahead
      - write_begin
        
        begin to write data to page
      - write_end
      - direct_IO
      - is_partially_uptodate
      - is_dirty_writeback
      - set_page_dirty
  - - - function
        
        walking path
      - relation with inode
        
        dentry usually has a pointer to an inode
    - - basics
        
        filesystem objects such as regular files, directories, FIFOs and other
        beasts
        
        Whoever sets up the inode is responsible for filling in the "i_op" field
        
        kernfs_init_inode
        
        kernfs_iop_lookup
        
        i_data(address_space) is embedded
      - lookup inode
        
        VFS calls lookup() method of
        the parent directory inode
    - - opened
        
        dentry is in use
        
        inode is in use
    - - represents a mounted filesystem
    - - function
        
        group and manage pages in the page cache
        
        communicating memory pressure
        
        page lookup by address
        
        xarray
        
        keeping track of pages tagged as Dirty or Writeback
        
        The Dirty tag is primarily used by mpage_writepages
        
        The Writeback tag is used by filemapwait and sync_page*
        
        PG_Dirty flag
        
        Dirty is set after data is written to page
        
        typically remains set until writepage asks for it to be written
        
        PG_Writeback flag
        
        set when starting writeback
        
        clear when writeback is done
        
        page->private
        
        buffer head
        
        iomap