Module: AUFSProbe

Defined in:
lib/fs/MiqFS/modules/AUFSProbe.rb

Constant Summary collapse

AUFS_SUPER_OFFSET =

TODO: Verify these offsets - in the standard superblock, sig (magic) is a short surrounded by two valid shorts.

1024
AUFS_MAGIC_OFFSET = 
52
AUFS_MAGIC_SIZE = 
4
AUFS_SUPER_MAGIC = 
0x12121313
AUFS_FSTYPE = 
"aufs".freeze

Class Method Summary collapse

Class Method Details

.probe(dobj) ⇒ Object 



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# File 'lib/fs/MiqFS/modules/AUFSProbe.rb', line 12

def self.probe(dobj)
  return false unless dobj.kind_of?(MiqDisk)

  # Check for aufs magic number or name at offset.
  dobj.seek(AUFS_SUPER_OFFSET + AUFS_MAGIC_OFFSET)
  buf = dobj.read(AUFS_MAGIC_SIZE)
  bs = buf&.unpack('L')
  magic = bs.nil? ? nil : bs[0]

  raise "AUFS is Not Supported" if magic == AUFS_SUPER_MAGIC || buf == AUFS_FSTYPE

  # No AUFS.
  false
end