kernel_file_open(): get rid of inode argument

always equal to ->dentry->d_inode of the path argument these
days.

Reviewed-by: Christian Brauner <[e-mail]>
Signed-off-by: Al Viro <[e-mail]>

fs/cachefiles/namei.c

···
 	 */
 	path.mnt = cache->mnt;
 	path.dentry = dentry;
-	file = kernel_file_open(&path, O_RDWR | O_LARGEFILE | O_DIRECT,
-				d_backing_inode(dentry), cache->cache_cred);
+	file = kernel_file_open(&path, O_RDWR | O_LARGEFILE | O_DIRECT, cache->cache_cred);
 	if (IS_ERR(file)) {
 		trace_cachefiles_vfs_error(object, d_backing_inode(dentry),
 					   PTR_ERR(file),

fs/open.c

···
  * kernel_file_open - open a file for kernel internal use
  * @path:	path of the file to open
  * @flags:	open flags
- * @inode:	the inode
  * @cred:	credentials for open
  *
  * Open a file for use by in-kernel consumers. The file is not accounted
···
  * Return: Opened file on success, an error pointer on failure.
  */
 struct file *kernel_file_open(const struct path *path, int flags,
-				struct inode *inode, const struct cred *cred)
+				const struct cred *cred)
 {
 	struct file *f;
 	int error;
···
 		return f;
 
 	f->f_path = *path;
-	error = do_dentry_open(f, inode, NULL);
+	error = do_dentry_open(f, d_inode(path->dentry), NULL);
 	if (error) {
 		fput(f);
 		f = ERR_PTR(error);

fs/overlayfs/util.c

···
 		 * If this inode was not yet opened, the verity info hasn't been
 		 * loaded yet, so we need to do that here to force it into memory.
 		 */
-		filp = kernel_file_open(datapath, O_RDONLY, inode, current_cred());
+		filp = kernel_file_open(datapath, O_RDONLY, current_cred());
 		if (IS_ERR(filp))
 			return PTR_ERR(filp);
 		fput(filp);

include/linux/fs.h

···
 				 umode_t mode, int open_flag,
 				 const struct cred *cred);
 struct file *kernel_file_open(const struct path *path, int flags,
-			      struct inode *inode, const struct cred *cred);
+			      const struct cred *cred);
 
 int vfs_mkobj(struct dentry *, umode_t,
 		int (*f)(struct dentry *, umode_t, void *),