select
  fs_name,                                 -- FS_NAME VARCHAR2(1024)
  available_time,                          -- AVAILABLE_TIME DATE
  block_size,                              -- BLOCK_SIZE NUMBER
  state,                                   -- STATE VARCHAR2(13)
  corrupt,                                 -- CORRUPT VARCHAR2(5)
  num_vol,                                 -- NUM_VOL NUMBER
  total_size,                              -- TOTAL_SIZE NUMBER
  total_free,                              -- TOTAL_FREE NUMBER
  total_snap_space_usage                   -- TOTAL_SNAP_SPACE_USAGE NUMBER
from
  gv$asm_filesystem
where
  inst_id = USERENV('Instance')