fuse: prepare fuse_direct_io() for CUSE

Move code operating on the inode out from fuse_direct_io().

This prepares this function for use by CUSE, where the inode is not
owned by a fuse filesystem.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>

fs/fuse/file.c

@@ -993,9 +993,6 @@ static ssize_t fuse_direct_io(struct file *file, const char __user *buf,
 	ssize_t res = 0;
 	struct fuse_req *req;
 
-	if (is_bad_inode(inode))
-		return -EIO;
-
 	req = fuse_get_req(fc);
 	if (IS_ERR(req))
 		return PTR_ERR(req);
@@ -1038,12 +1035,8 @@ static ssize_t fuse_direct_io(struct file *file, const char __user *buf,
 		}
 	}
 	fuse_put_request(fc, req);
-	if (res > 0) {
-		if (write)
-			fuse_write_update_size(inode, pos);
+	if (res > 0)
 		*ppos = pos;
-	}
-	fuse_invalidate_attr(inode);
 
 	return res;
 }
@@ -1051,7 +1044,17 @@ static ssize_t fuse_direct_io(struct file *file, const char __user *buf,
 static ssize_t fuse_direct_read(struct file *file, char __user *buf,
 				     size_t count, loff_t *ppos)
 {
-	return fuse_direct_io(file, buf, count, ppos, 0);
+	ssize_t res;
+	struct inode *inode = file->f_path.dentry->d_inode;
+
+	if (is_bad_inode(inode))
+		return -EIO;
+
+	res = fuse_direct_io(file, buf, count, ppos, 0);
+
+	fuse_invalidate_attr(inode);
+
+	return res;
 }
 
 static ssize_t fuse_direct_write(struct file *file, const char __user *buf,
@@ -1059,12 +1062,22 @@ static ssize_t fuse_direct_write(struct file *file, const char __user *buf,
 {
 	struct inode *inode = file->f_path.dentry->d_inode;
 	ssize_t res;
+
+	if (is_bad_inode(inode))
+		return -EIO;
+
 	/* Don't allow parallel writes to the same file */
 	mutex_lock(&inode->i_mutex);
 	res = generic_write_checks(file, ppos, &count, 0);
-	if (!res)
+	if (!res) {
 		res = fuse_direct_io(file, buf, count, ppos, 1);
+		if (res > 0)
+			fuse_write_update_size(inode, *ppos);
+	}
 	mutex_unlock(&inode->i_mutex);
+
+	fuse_invalidate_attr(inode);
+
 	return res;
 }