mask that identifies what fields to set in setattr
POSIX defines st_blocks to be the number of 512 byte blocks allocated to the file. The “blkcnt” field of vnattr attempts to accomplish this same goal, but by indirecting through VNATTR_BLKSIZE, we reserve the right to change this “block size unit” (which is distinct from “blksize”, because POSIX) whenever we want.
bits compatible with POSIX stat
Mask of which bits to set for setattr.
Block size for filesystem I/O.
Number of VNATTR_BLKSIZE
byte blocks allocated.
POSIX time (seconds since epoch).
POSIX time (seconds since epoch).