file->f_op is never NULL...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

drivers/mtd/nand/nandsim.c

@@ -575,7 +575,7 @@ static int alloc_device(struct nandsim *ns)
 		cfile = filp_open(cache_file, O_CREAT | O_RDWR | O_LARGEFILE, 0600);
 		if (IS_ERR(cfile))
 			return PTR_ERR(cfile);
-		if (!cfile->f_op || (!cfile->f_op->read && !cfile->f_op->aio_read)) {
+		if (!cfile->f_op->read && !cfile->f_op->aio_read) {
 			NS_ERR("alloc_device: cache file not readable\n");
 			err = -EINVAL;
 			goto err_close;

drivers/staging/comedi/comedi_compat32.c

@@ -86,9 +86,6 @@ struct comedi32_insnlist_struct {
 static int translated_ioctl(struct file *file, unsigned int cmd,
 			    unsigned long arg)
 {
-	if (!file->f_op)
-		return -ENOTTY;
-
 	if (file->f_op->unlocked_ioctl)
 		return file->f_op->unlocked_ioctl(file, cmd, arg);
 

fs/autofs4/autofs_i.h

@@ -271,7 +271,7 @@ void autofs4_clean_ino(struct autofs_info *);
 
 static inline int autofs_prepare_pipe(struct file *pipe)
 {
-	if (!pipe->f_op || !pipe->f_op->write)
+	if (!pipe->f_op->write)
 		return -EINVAL;
 	if (!S_ISFIFO(file_inode(pipe)->i_mode))
 		return -EINVAL;

fs/autofs4/dev-ioctl.c

@@ -658,12 +658,6 @@ static int _autofs_dev_ioctl(unsigned int command, struct autofs_dev_ioctl __use
 			goto out;
 		}
 
-		if (!fp->f_op) {
-			err = -ENOTTY;
-			fput(fp);
-			goto out;
-		}
-
 		sbi = autofs_dev_ioctl_sbi(fp);
 		if (!sbi || sbi->magic != AUTOFS_SBI_MAGIC) {
 			err = -EINVAL;

fs/binfmt_aout.c

@@ -221,7 +221,7 @@ static int load_aout_binary(struct linux_binprm * bprm)
 	 * Requires a mmap handler. This prevents people from using a.out
 	 * as part of an exploit attack against /proc-related vulnerabilities.
 	 */
-	if (!bprm->file->f_op || !bprm->file->f_op->mmap)
+	if (!bprm->file->f_op->mmap)
 		return -ENOEXEC;
 
 	fd_offset = N_TXTOFF(ex);
@@ -374,7 +374,7 @@ static int load_aout_library(struct file *file)
 	 * Requires a mmap handler. This prevents people from using a.out
 	 * as part of an exploit attack against /proc-related vulnerabilities.
 	 */
-	if (!file->f_op || !file->f_op->mmap)
+	if (!file->f_op->mmap)
 		goto out;
 
 	if (N_FLAGS(ex))

fs/binfmt_elf.c

@@ -406,7 +406,7 @@ static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex,
 		goto out;
 	if (!elf_check_arch(interp_elf_ex))
 		goto out;
-	if (!interpreter->f_op || !interpreter->f_op->mmap)
+	if (!interpreter->f_op->mmap)
 		goto out;
 
 	/*
@@ -607,7 +607,7 @@ static int load_elf_binary(struct linux_binprm *bprm)
 		goto out;
 	if (!elf_check_arch(&loc->elf_ex))
 		goto out;
-	if (!bprm->file->f_op || !bprm->file->f_op->mmap)
+	if (!bprm->file->f_op->mmap)
 		goto out;
 
 	/* Now read in all of the header information */
@@ -1028,7 +1028,7 @@ static int load_elf_library(struct file *file)
 
 	/* First of all, some simple consistency checks */
 	if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 ||
-	    !elf_check_arch(&elf_ex) || !file->f_op || !file->f_op->mmap)
+	    !elf_check_arch(&elf_ex) || !file->f_op->mmap)
 		goto out;
 
 	/* Now read in all of the header information */

fs/binfmt_elf_fdpic.c

@@ -111,7 +111,7 @@ static int is_elf_fdpic(struct elfhdr *hdr, struct file *file)
 		return 0;
 	if (!elf_check_arch(hdr) || !elf_check_fdpic(hdr))
 		return 0;
-	if (!file->f_op || !file->f_op->mmap)
+	if (!file->f_op->mmap)
 		return 0;
 	return 1;
 }

fs/binfmt_em86.c

@@ -38,7 +38,7 @@ static int load_em86(struct linux_binprm *bprm)
 	/* First of all, some simple consistency checks */
 	if ((elf_ex.e_type != ET_EXEC && elf_ex.e_type != ET_DYN) ||
 		(!((elf_ex.e_machine == EM_386) || (elf_ex.e_machine == EM_486))) ||
-		(!bprm->file->f_op || !bprm->file->f_op->mmap)) {
+		!bprm->file->f_op->mmap) {
 			return -ENOEXEC;
 	}
 

fs/coda/dir.c

@@ -387,9 +387,6 @@ static int coda_readdir(struct file *coda_file, struct dir_context *ctx)
 	BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
 	host_file = cfi->cfi_container;
 
-	if (!host_file->f_op)
-		return -ENOTDIR;
-
 	if (host_file->f_op->iterate) {
 		struct inode *host_inode = file_inode(host_file);
 		mutex_lock(&host_inode->i_mutex);

fs/coda/file.c

@@ -36,7 +36,7 @@ coda_file_read(struct file *coda_file, char __user *buf, size_t count, loff_t *p
 	BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
 	host_file = cfi->cfi_container;
 
-	if (!host_file->f_op || !host_file->f_op->read)
+	if (!host_file->f_op->read)
 		return -EINVAL;
 
 	return host_file->f_op->read(host_file, buf, count, ppos);
@@ -75,7 +75,7 @@ coda_file_write(struct file *coda_file, const char __user *buf, size_t count, lo
 	BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
 	host_file = cfi->cfi_container;
 
-	if (!host_file->f_op || !host_file->f_op->write)
+	if (!host_file->f_op->write)
 		return -EINVAL;
 
 	host_inode = file_inode(host_file);
@@ -105,7 +105,7 @@ coda_file_mmap(struct file *coda_file, struct vm_area_struct *vma)
 	BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
 	host_file = cfi->cfi_container;
 
-	if (!host_file->f_op || !host_file->f_op->mmap)
+	if (!host_file->f_op->mmap)
 		return -ENODEV;
 
 	coda_inode = file_inode(coda_file);

fs/compat_ioctl.c

@@ -1583,13 +1583,13 @@ asmlinkage long compat_sys_ioctl(unsigned int fd, unsigned int cmd,
 		/*FALL THROUGH*/
 
 	default:
-		if (f.file->f_op && f.file->f_op->compat_ioctl) {
+		if (f.file->f_op->compat_ioctl) {
 			error = f.file->f_op->compat_ioctl(f.file, cmd, arg);
 			if (error != -ENOIOCTLCMD)
 				goto out_fput;
 		}
 
-		if (!f.file->f_op || !f.file->f_op->unlocked_ioctl)
+		if (!f.file->f_op->unlocked_ioctl)
 			goto do_ioctl;
 		break;
 	}

fs/coredump.c

@@ -645,7 +645,7 @@ void do_coredump(siginfo_t *siginfo)
 		 */
 		if (!uid_eq(inode->i_uid, current_fsuid()))
 			goto close_fail;
-		if (!cprm.file->f_op || !cprm.file->f_op->write)
+		if (!cprm.file->f_op->write)
 			goto close_fail;
 		if (do_truncate(cprm.file->f_path.dentry, 0, 0, cprm.file))
 			goto close_fail;

fs/ecryptfs/file.c

@@ -271,7 +271,7 @@ static int ecryptfs_flush(struct file *file, fl_owner_t td)
 {
 	struct file *lower_file = ecryptfs_file_to_lower(file);
 
-	if (lower_file->f_op && lower_file->f_op->flush) {
+	if (lower_file->f_op->flush) {
 		filemap_write_and_wait(file->f_mapping);
 		return lower_file->f_op->flush(lower_file, td);
 	}
@@ -305,7 +305,7 @@ static int ecryptfs_fasync(int fd, struct file *file, int flag)
 	struct file *lower_file = NULL;
 
 	lower_file = ecryptfs_file_to_lower(file);
-	if (lower_file->f_op && lower_file->f_op->fasync)
+	if (lower_file->f_op->fasync)
 		rc = lower_file->f_op->fasync(fd, lower_file, flag);
 	return rc;
 }
@@ -318,7 +318,7 @@ ecryptfs_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 
 	if (ecryptfs_file_to_private(file))
 		lower_file = ecryptfs_file_to_lower(file);
-	if (lower_file && lower_file->f_op && lower_file->f_op->unlocked_ioctl)
+	if (lower_file->f_op && lower_file->f_op->unlocked_ioctl)
 		rc = lower_file->f_op->unlocked_ioctl(lower_file, cmd, arg);
 	return rc;
 }
@@ -332,7 +332,7 @@ ecryptfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 
 	if (ecryptfs_file_to_private(file))
 		lower_file = ecryptfs_file_to_lower(file);
-	if (lower_file && lower_file->f_op && lower_file->f_op->compat_ioctl)
+	if (lower_file->f_op && lower_file->f_op->compat_ioctl)
 		rc = lower_file->f_op->compat_ioctl(lower_file, cmd, arg);
 	return rc;
 }

fs/eventpoll.c

@@ -1816,7 +1816,7 @@ SYSCALL_DEFINE4(epoll_ctl, int, epfd, int, op, int, fd,
 
 	/* The target file descriptor must support poll */
 	error = -EPERM;
-	if (!tf.file->f_op || !tf.file->f_op->poll)
+	if (!tf.file->f_op->poll)
 		goto error_tgt_fput;
 
 	/* Check if EPOLLWAKEUP is allowed */

fs/exec.c

@@ -106,6 +106,7 @@ static inline void put_binfmt(struct linux_binfmt * fmt)
  */
 SYSCALL_DEFINE1(uselib, const char __user *, library)
 {
+	struct linux_binfmt *fmt;
 	struct file *file;
 	struct filename *tmp = getname(library);
 	int error = PTR_ERR(tmp);
@@ -136,8 +137,6 @@ SYSCALL_DEFINE1(uselib, const char __user *, library)
 	fsnotify_open(file);
 
 	error = -ENOEXEC;
-	if(file->f_op) {
-		struct linux_binfmt * fmt;
 
 	read_lock(&binfmt_lock);
 	list_for_each_entry(fmt, &formats, lh) {
@@ -153,7 +152,6 @@ SYSCALL_DEFINE1(uselib, const char __user *, library)
 			break;
 	}
 	read_unlock(&binfmt_lock);
-	}
 exit:
 	fput(file);
 out:
@@ -1277,13 +1275,10 @@ static int check_unsafe_exec(struct linux_binprm *bprm)
  */
 int prepare_binprm(struct linux_binprm *bprm)
 {
-	umode_t mode;
-	struct inode * inode = file_inode(bprm->file);
+	struct inode *inode = file_inode(bprm->file);
+	umode_t mode = inode->i_mode;
 	int retval;
 
-	mode = inode->i_mode;
-	if (bprm->file->f_op == NULL)
-		return -EACCES;
 
 	/* clear any previous set[ug]id data from a previous binary */
 	bprm->cred->euid = current_euid();

fs/fcntl.c

@@ -56,7 +56,7 @@ static int setfl(int fd, struct file * filp, unsigned long arg)
 				return -EINVAL;
 	}
 
-	if (filp->f_op && filp->f_op->check_flags)
+	if (filp->f_op->check_flags)
 		error = filp->f_op->check_flags(arg);
 	if (error)
 		return error;
@@ -64,8 +64,7 @@ static int setfl(int fd, struct file * filp, unsigned long arg)
 	/*
 	 * ->fasync() is responsible for setting the FASYNC bit.
 	 */
-	if (((arg ^ filp->f_flags) & FASYNC) && filp->f_op &&
-			filp->f_op->fasync) {
+	if (((arg ^ filp->f_flags) & FASYNC) && filp->f_op->fasync) {
 		error = filp->f_op->fasync(fd, filp, (arg & FASYNC) != 0);
 		if (error < 0)
 			goto out;

fs/file_table.c

@@ -240,11 +240,11 @@ static void __fput(struct file *file)
 	locks_remove_flock(file);
 
 	if (unlikely(file->f_flags & FASYNC)) {
-		if (file->f_op && file->f_op->fasync)
+		if (file->f_op->fasync)
 			file->f_op->fasync(-1, file, 0);
 	}
 	ima_file_free(file);
-	if (file->f_op && file->f_op->release)
+	if (file->f_op->release)
 		file->f_op->release(inode, file);
 	security_file_free(file);
 	if (unlikely(S_ISCHR(inode->i_mode) && inode->i_cdev != NULL &&

fs/ioctl.c

@@ -37,7 +37,7 @@ static long vfs_ioctl(struct file *filp, unsigned int cmd,
 {
 	int error = -ENOTTY;
 
-	if (!filp->f_op || !filp->f_op->unlocked_ioctl)
+	if (!filp->f_op->unlocked_ioctl)
 		goto out;
 
 	error = filp->f_op->unlocked_ioctl(filp, cmd, arg);
@@ -501,7 +501,7 @@ static int ioctl_fioasync(unsigned int fd, struct file *filp,
 
 	/* Did FASYNC state change ? */
 	if ((flag ^ filp->f_flags) & FASYNC) {
-		if (filp->f_op && filp->f_op->fasync)
+		if (filp->f_op->fasync)
 			/* fasync() adjusts filp->f_flags */
 			error = filp->f_op->fasync(fd, filp, on);
 		else

fs/locks.c

@@ -1579,7 +1579,7 @@ EXPORT_SYMBOL(generic_setlease);
 
 static int __vfs_setlease(struct file *filp, long arg, struct file_lock **lease)
 {
-	if (filp->f_op && filp->f_op->setlease)
+	if (filp->f_op->setlease)
 		return filp->f_op->setlease(filp, arg, lease);
 	else
 		return generic_setlease(filp, arg, lease);
@@ -1771,7 +1771,7 @@ SYSCALL_DEFINE2(flock, unsigned int, fd, unsigned int, cmd)
 	if (error)
 		goto out_free;
 
-	if (f.file->f_op && f.file->f_op->flock)
+	if (f.file->f_op->flock)
 		error = f.file->f_op->flock(f.file,
 					  (can_sleep) ? F_SETLKW : F_SETLK,
 					  lock);
@@ -1797,7 +1797,7 @@ SYSCALL_DEFINE2(flock, unsigned int, fd, unsigned int, cmd)
  */
 int vfs_test_lock(struct file *filp, struct file_lock *fl)
 {
-	if (filp->f_op && filp->f_op->lock)
+	if (filp->f_op->lock)
 		return filp->f_op->lock(filp, F_GETLK, fl);
 	posix_test_lock(filp, fl);
 	return 0;
@@ -1909,7 +1909,7 @@ int fcntl_getlk(struct file *filp, struct flock __user *l)
  */
 int vfs_lock_file(struct file *filp, unsigned int cmd, struct file_lock *fl, struct file_lock *conf)
 {
-	if (filp->f_op && filp->f_op->lock)
+	if (filp->f_op->lock)
 		return filp->f_op->lock(filp, cmd, fl);
 	else
 		return posix_lock_file(filp, fl, conf);
@@ -2182,7 +2182,7 @@ void locks_remove_flock(struct file *filp)
 	if (!inode->i_flock)
 		return;
 
-	if (filp->f_op && filp->f_op->flock) {
+	if (filp->f_op->flock) {
 		struct file_lock fl = {
 			.fl_pid = current->tgid,
 			.fl_file = filp,
@@ -2246,7 +2246,7 @@ EXPORT_SYMBOL(posix_unblock_lock);
  */
 int vfs_cancel_lock(struct file *filp, struct file_lock *fl)
 {
-	if (filp->f_op && filp->f_op->lock)
+	if (filp->f_op->lock)
 		return filp->f_op->lock(filp, F_CANCELLK, fl);
 	return 0;
 }

fs/open.c

@@ -693,6 +693,10 @@ static int do_dentry_open(struct file *f,
 	}
 
 	f->f_op = fops_get(inode->i_fop);
+	if (unlikely(WARN_ON(!f->f_op))) {
+		error = -ENODEV;
+		goto cleanup_all;
+	}
 
 	error = security_file_open(f, cred);
 	if (error)
@@ -702,7 +706,7 @@ static int do_dentry_open(struct file *f,
 	if (error)
 		goto cleanup_all;
 
-	if (!open && f->f_op)
+	if (!open)
 		open = f->f_op->open;
 	if (open) {
 		error = open(inode, f);
@@ -1023,7 +1027,7 @@ int filp_close(struct file *filp, fl_owner_t id)
 		return 0;
 	}
 
-	if (filp->f_op && filp->f_op->flush)
+	if (filp->f_op->flush)
 		retval = filp->f_op->flush(filp, id);
 
 	if (likely(!(filp->f_mode & FMODE_PATH))) {

fs/read_write.c

@@ -257,7 +257,7 @@ loff_t vfs_llseek(struct file *file, loff_t offset, int whence)
 
 	fn = no_llseek;
 	if (file->f_mode & FMODE_LSEEK) {
-		if (file->f_op && file->f_op->llseek)
+		if (file->f_op->llseek)
 			fn = file->f_op->llseek;
 	}
 	return fn(file, offset, whence);
@@ -384,7 +384,7 @@ ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos)
 
 	if (!(file->f_mode & FMODE_READ))
 		return -EBADF;
-	if (!file->f_op || (!file->f_op->read && !file->f_op->aio_read))
+	if (!file->f_op->read && !file->f_op->aio_read)
 		return -EINVAL;
 	if (unlikely(!access_ok(VERIFY_WRITE, buf, count)))
 		return -EFAULT;
@@ -433,7 +433,7 @@ ssize_t __kernel_write(struct file *file, const char *buf, size_t count, loff_t
 	const char __user *p;
 	ssize_t ret;
 
-	if (!file->f_op || (!file->f_op->write && !file->f_op->aio_write))
+	if (!file->f_op->write && !file->f_op->aio_write)
 		return -EINVAL;
 
 	old_fs = get_fs();
@@ -460,7 +460,7 @@ ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_
 
 	if (!(file->f_mode & FMODE_WRITE))
 		return -EBADF;
-	if (!file->f_op || (!file->f_op->write && !file->f_op->aio_write))
+	if (!file->f_op->write && !file->f_op->aio_write)
 		return -EINVAL;
 	if (unlikely(!access_ok(VERIFY_READ, buf, count)))
 		return -EFAULT;
@@ -727,11 +727,6 @@ static ssize_t do_readv_writev(int type, struct file *file,
 	io_fn_t fn;
 	iov_fn_t fnv;
 
-	if (!file->f_op) {
-		ret = -EINVAL;
-		goto out;
-	}
-
 	ret = rw_copy_check_uvector(type, uvector, nr_segs,
 				    ARRAY_SIZE(iovstack), iovstack, &iov);
 	if (ret <= 0)
@@ -778,7 +773,7 @@ ssize_t vfs_readv(struct file *file, const struct iovec __user *vec,
 {
 	if (!(file->f_mode & FMODE_READ))
 		return -EBADF;
-	if (!file->f_op || (!file->f_op->aio_read && !file->f_op->read))
+	if (!file->f_op->aio_read && !file->f_op->read)
 		return -EINVAL;
 
 	return do_readv_writev(READ, file, vec, vlen, pos);
@@ -791,7 +786,7 @@ ssize_t vfs_writev(struct file *file, const struct iovec __user *vec,
 {
 	if (!(file->f_mode & FMODE_WRITE))
 		return -EBADF;
-	if (!file->f_op || (!file->f_op->aio_write && !file->f_op->write))
+	if (!file->f_op->aio_write && !file->f_op->write)
 		return -EINVAL;
 
 	return do_readv_writev(WRITE, file, vec, vlen, pos);
@@ -906,10 +901,6 @@ static ssize_t compat_do_readv_writev(int type, struct file *file,
 	io_fn_t fn;
 	iov_fn_t fnv;
 
-	ret = -EINVAL;
-	if (!file->f_op)
-		goto out;
-
 	ret = -EFAULT;
 	if (!access_ok(VERIFY_READ, uvector, nr_segs*sizeof(*uvector)))
 		goto out;
@@ -965,7 +956,7 @@ static size_t compat_readv(struct file *file,
 		goto out;
 
 	ret = -EINVAL;
-	if (!file->f_op || (!file->f_op->aio_read && !file->f_op->read))
+	if (!file->f_op->aio_read && !file->f_op->read)
 		goto out;
 
 	ret = compat_do_readv_writev(READ, file, vec, vlen, pos);
@@ -1032,7 +1023,7 @@ static size_t compat_writev(struct file *file,
 		goto out;
 
 	ret = -EINVAL;
-	if (!file->f_op || (!file->f_op->aio_write && !file->f_op->write))
+	if (!file->f_op->aio_write && !file->f_op->write)
 		goto out;
 
 	ret = compat_do_readv_writev(WRITE, file, vec, vlen, pos);

fs/readdir.c

@@ -24,7 +24,7 @@ int iterate_dir(struct file *file, struct dir_context *ctx)
 {
 	struct inode *inode = file_inode(file);
 	int res = -ENOTDIR;
-	if (!file->f_op || !file->f_op->iterate)
+	if (!file->f_op->iterate)
 		goto out;
 
 	res = security_file_permission(file, MAY_READ);

fs/select.c

@@ -455,7 +455,7 @@ int do_select(int n, fd_set_bits *fds, struct timespec *end_time)
 					const struct file_operations *f_op;
 					f_op = f.file->f_op;
 					mask = DEFAULT_POLLMASK;
-					if (f_op && f_op->poll) {
+					if (f_op->poll) {
 						wait_key_set(wait, in, out,
 							     bit, busy_flag);
 						mask = (*f_op->poll)(f.file, wait);
@@ -762,7 +762,7 @@ static inline unsigned int do_pollfd(struct pollfd *pollfd, poll_table *pwait,
 		mask = POLLNVAL;
 		if (f.file) {
 			mask = DEFAULT_POLLMASK;
-			if (f.file->f_op && f.file->f_op->poll) {
+			if (f.file->f_op->poll) {
 				pwait->_key = pollfd->events|POLLERR|POLLHUP;
 				pwait->_key |= busy_flag;
 				mask = f.file->f_op->poll(f.file, pwait);

fs/splice.c

@@ -695,7 +695,7 @@ static int pipe_to_sendpage(struct pipe_inode_info *pipe,
 	loff_t pos = sd->pos;
 	int more;
 
-	if (!likely(file->f_op && file->f_op->sendpage))
+	if (!likely(file->f_op->sendpage))
 		return -EINVAL;
 
 	more = (sd->flags & SPLICE_F_MORE) ? MSG_MORE : 0;
@@ -1099,7 +1099,7 @@ static long do_splice_from(struct pipe_inode_info *pipe, struct file *out,
 	ssize_t (*splice_write)(struct pipe_inode_info *, struct file *,
 				loff_t *, size_t, unsigned int);
 
-	if (out->f_op && out->f_op->splice_write)
+	if (out->f_op->splice_write)
 		splice_write = out->f_op->splice_write;
 	else
 		splice_write = default_file_splice_write;
@@ -1125,7 +1125,7 @@ static long do_splice_to(struct file *in, loff_t *ppos,
 	if (unlikely(ret < 0))
 		return ret;
 
-	if (in->f_op && in->f_op->splice_read)
+	if (in->f_op->splice_read)
 		splice_read = in->f_op->splice_read;
 	else
 		splice_read = default_file_splice_read;

fs/sync.c

@@ -177,7 +177,7 @@ SYSCALL_DEFINE1(syncfs, int, fd)
  */
 int vfs_fsync_range(struct file *file, loff_t start, loff_t end, int datasync)
 {
-	if (!file->f_op || !file->f_op->fsync)
+	if (!file->f_op->fsync)
 		return -EINVAL;
 	return file->f_op->fsync(file, start, end, datasync);
 }

mm/memory.c

@@ -681,7 +681,7 @@ static void print_bad_pte(struct vm_area_struct *vma, unsigned long addr,
 	if (vma->vm_ops)
 		printk(KERN_ALERT "vma->vm_ops->fault: %pSR\n",
 		       vma->vm_ops->fault);
-	if (vma->vm_file && vma->vm_file->f_op)
+	if (vma->vm_file)
 		printk(KERN_ALERT "vma->vm_file->f_op->mmap: %pSR\n",
 		       vma->vm_file->f_op->mmap);
 	dump_stack();

mm/mmap.c

@@ -1299,7 +1299,7 @@ unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
 				vm_flags &= ~VM_MAYEXEC;
 			}
 
-			if (!file->f_op || !file->f_op->mmap)
+			if (!file->f_op->mmap)
 				return -ENODEV;
 			if (vm_flags & (VM_GROWSDOWN|VM_GROWSUP))
 				return -EINVAL;
@@ -1951,7 +1951,7 @@ get_unmapped_area(struct file *file, unsigned long addr, unsigned long len,
 		return -ENOMEM;
 
 	get_area = current->mm->get_unmapped_area;
-	if (file && file->f_op && file->f_op->get_unmapped_area)
+	if (file && file->f_op->get_unmapped_area)
 		get_area = file->f_op->get_unmapped_area;
 	addr = get_area(file, addr, len, pgoff, flags);
 	if (IS_ERR_VALUE(addr))

mm/nommu.c

@@ -937,7 +937,7 @@ static int validate_mmap_request(struct file *file,
 		struct address_space *mapping;
 
 		/* files must support mmap */
-		if (!file->f_op || !file->f_op->mmap)
+		if (!file->f_op->mmap)
 			return -ENODEV;
 
 		/* work out if what we've got could possibly be shared

net/9p/trans_fd.c

@@ -244,10 +244,10 @@ p9_fd_poll(struct p9_client *client, struct poll_table_struct *pt)
 	if (!ts)
 		return -EREMOTEIO;
 
-	if (!ts->rd->f_op || !ts->rd->f_op->poll)
+	if (!ts->rd->f_op->poll)
 		return -EIO;
 
-	if (!ts->wr->f_op || !ts->wr->f_op->poll)
+	if (!ts->wr->f_op->poll)
 		return -EIO;
 
 	ret = ts->rd->f_op->poll(ts->rd, pt);