file->f_op is never NULL...

drivers/mtd/nand/nandsim.c

drivers/staging/comedi/comedi_compat32.c

fs/autofs4/autofs_i.h

fs/autofs4/dev-ioctl.c

fs/binfmt_aout.c

fs/binfmt_elf.c

fs/binfmt_elf_fdpic.c

fs/binfmt_em86.c

fs/coda/dir.c

fs/coda/file.c

fs/compat_ioctl.c

fs/coredump.c

fs/ecryptfs/file.c

fs/eventpoll.c

fs/exec.c

fs/fcntl.c

fs/file_table.c

fs/ioctl.c

fs/locks.c

fs/open.c