ovl: simplify getting inode

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

fs/overlayfs/inode.c

@@ -462,18 +462,28 @@ static int ovl_inode_set(struct inode *inode, void *data)
 	return 0;
 }
 
-struct inode *ovl_get_inode(struct super_block *sb, struct inode *realinode)
-
+struct inode *ovl_get_inode(struct dentry *dentry)
 {
+	struct dentry *upperdentry = ovl_dentry_upper(dentry);
+	struct inode *realinode = d_inode(ovl_dentry_real(dentry));
 	struct inode *inode;
 
-	inode = iget5_locked(sb, (unsigned long) realinode,
+	if (upperdentry && !d_is_dir(upperdentry)) {
+		inode = iget5_locked(dentry->d_sb, (unsigned long) realinode,
 				     ovl_inode_test, ovl_inode_set, realinode);
-	if (inode && inode->i_state & I_NEW) {
-		ovl_fill_inode(inode, realinode->i_mode, realinode->i_rdev);
+		if (!inode || !(inode->i_state & I_NEW))
+			goto out;
+
 		set_nlink(inode, realinode->i_nlink);
-		unlock_new_inode(inode);
+	} else {
+		inode = new_inode(dentry->d_sb);
+		if (!inode)
+			goto out;
 	}
-
+	ovl_fill_inode(inode, realinode->i_mode, realinode->i_rdev);
+	ovl_inode_init(inode, dentry);
+	if (inode->i_state & I_NEW)
+		unlock_new_inode(inode);
+out:
 	return inode;
 }

fs/overlayfs/namei.c

@@ -433,41 +433,29 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
 	if (!oe)
 		goto out_put;
 
-	if (upperdentry || ctr) {
-		struct dentry *realdentry;
-		struct inode *realinode;
-
-		realdentry = upperdentry ? upperdentry : stack[0].dentry;
-		realinode = d_inode(realdentry);
+	oe->opaque = upperopaque;
+	oe->impure = upperimpure;
+	oe->redirect = upperredirect;
+	oe->__upperdentry = upperdentry;
+	memcpy(oe->lowerstack, stack, sizeof(struct path) * ctr);
+	dentry->d_fsdata = oe;
 
+	if (upperdentry || ctr) {
 		err = -ENOMEM;
-		if (upperdentry && !d_is_dir(upperdentry)) {
-			inode = ovl_get_inode(dentry->d_sb, realinode);
-		} else {
-			inode = ovl_new_inode(dentry->d_sb, realinode->i_mode,
-					      realinode->i_rdev);
-			if (inode)
-				ovl_inode_init(inode, realinode, !!upperdentry);
-		}
+		inode = ovl_get_inode(dentry);
 		if (!inode)
 			goto out_free_oe;
-		ovl_copyattr(realdentry->d_inode, inode);
 	}
 
 	revert_creds(old_cred);
-	oe->opaque = upperopaque;
-	oe->impure = upperimpure;
-	oe->redirect = upperredirect;
-	oe->__upperdentry = upperdentry;
-	memcpy(oe->lowerstack, stack, sizeof(struct path) * ctr);
 	kfree(stack);
 	kfree(d.redirect);
-	dentry->d_fsdata = oe;
 	d_add(dentry, inode);
 
 	return NULL;
 
 out_free_oe:
+	dentry->d_fsdata = NULL;
 	kfree(oe);
 out_put:
 	for (i = 0; i < ctr; i++)

fs/overlayfs/overlayfs.h

@@ -211,8 +211,7 @@ bool ovl_redirect_dir(struct super_block *sb);
 const char *ovl_dentry_get_redirect(struct dentry *dentry);
 void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect);
 void ovl_dentry_update(struct dentry *dentry, struct dentry *upperdentry);
-void ovl_inode_init(struct inode *inode, struct inode *realinode,
-		    bool is_upper);
+void ovl_inode_init(struct inode *inode, struct dentry *dentry);
 void ovl_inode_update(struct inode *inode, struct inode *upperinode);
 void ovl_dentry_version_inc(struct dentry *dentry);
 u64 ovl_dentry_version_get(struct dentry *dentry);
@@ -262,7 +261,7 @@ int ovl_update_time(struct inode *inode, struct timespec *ts, int flags);
 bool ovl_is_private_xattr(const char *name);
 
 struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, dev_t rdev);
-struct inode *ovl_get_inode(struct super_block *sb, struct inode *realinode);
+struct inode *ovl_get_inode(struct dentry *dentry);
 static inline void ovl_copyattr(struct inode *from, struct inode *to)
 {
 	to->i_uid = from->i_uid;

fs/overlayfs/super.c

@@ -757,7 +757,6 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
 	struct path upperpath = { };
 	struct path workpath = { };
 	struct dentry *root_dentry;
-	struct inode *realinode;
 	struct ovl_entry *oe;
 	struct ovl_fs *ufs;
 	struct path *stack = NULL;
@@ -1009,9 +1008,7 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
 
 	root_dentry->d_fsdata = oe;
 
-	realinode = d_inode(ovl_dentry_real(root_dentry));
-	ovl_inode_init(d_inode(root_dentry), realinode, !!upperpath.dentry);
-	ovl_copyattr(realinode, d_inode(root_dentry));
+	ovl_inode_init(d_inode(root_dentry), root_dentry);
 
 	sb->s_root = root_dentry;
 

fs/overlayfs/util.c

@@ -230,10 +230,15 @@ void ovl_dentry_update(struct dentry *dentry, struct dentry *upperdentry)
 	oe->__upperdentry = upperdentry;
 }
 
-void ovl_inode_init(struct inode *inode, struct inode *realinode, bool is_upper)
+void ovl_inode_init(struct inode *inode, struct dentry *dentry)
 {
+	struct inode *realinode = d_inode(ovl_dentry_real(dentry));
+	bool is_upper = ovl_dentry_upper(dentry);
+
 	WRITE_ONCE(inode->i_private, (unsigned long) realinode |
 		   (is_upper ? OVL_ISUPPER_MASK : 0));
+
+	ovl_copyattr(realinode, inode);
 }
 
 void ovl_inode_update(struct inode *inode, struct inode *upperinode)