Sysfs

• The sysfs Filesystem

include/linux/sysfs.h

• Shared header file

fs/sysfs/

• sysfs.h
  • Internal header file for sysfs
• mount.c
  • for interacting with the VFS layer
  • sysfs_init
    • called directly by the VFS initialization
    • responsible for
      • Creating a kmem_cache
      • Registering with the VFS
      • Mounts itself internally
• inode.c
  • allocating and freeing the core filesystem objects
• dir.c
  • creating and removing directories in the sysfs hierarchy
• file.c
  • creating and removing regular, ASCII files in the sysfs hierarchy
• group.c
  • helpers that aide in the creation and deletion of multiple regular files at a time
• symlink.c
  • creating and removing symlink in the sysfs hierarchy
• bin.c
  • creating and removing binary (non-ASCII) files

• sysctl(configure kernel parameters at runtime)
  • The sysctl Interface
  • BSD
    • sysctl system call
    • these parameters are generally objects in a Management Information Base
  • Linux
    • /proc interface
    • sysfs

• /sys/devices/
  • reflecting the physical layout

• /sys/bus/
  • populated with symbolic links
  • reflecting how the devices belong to different busses

• /sys/class/
  • shows devices grouped according to classes

• /sys/block/
  • contains the block devices