[PATCH v7 02/12] vfs: prepare vfs_creat|mkdir_no_perm for reuse in lookup_open()

@@ -4195,6 +4195,24 @@ static inline umode_t vfs_prepare_mode(struct mnt_idmap *idmap,
 	return mode;
 }
 
+static inline
+int vfs_create_no_perm(struct mnt_idmap *idmap, struct dentry *dentry,
+		       umode_t mode, struct delegated_inode *di)
+{
+	struct inode *dir = d_inode(dentry->d_parent);
+	int error;
+
+	error = try_break_deleg(dir, LEASE_BREAK_DIR_CREATE, di);
+	if (error)
+		return error;
+
+	error = dir->i_op->create(idmap, dir, dentry, mode);
+	if (!error)
+		fsnotify_create(dir, dentry);
+
+	return error;
+}
+
 /**
  * vfs_create - create new file
  * @idmap:	idmap of the mount the inode was found from

@@ -4227,13 +4245,8 @@ int vfs_create(struct mnt_idmap *idmap, struct dentry *dentry, umode_t mode,
 	error = security_inode_create(dir, dentry, mode);
 	if (error)
 		return error;
-	error = try_break_deleg(dir, LEASE_BREAK_DIR_CREATE, di);
-	if (error)
-		return error;
-	error = dir->i_op->create(idmap, dir, dentry, mode);
-	if (!error)
-		fsnotify_create(dir, dentry);
-	return error;
+
+	return vfs_create_no_perm(idmap, dentry, mode, di);
 }
 EXPORT_SYMBOL(vfs_create);
 

@@ -4447,6 +4460,7 @@ static struct dentry *atomic_open(const struct path *path, struct dentry *dentry
 		dput(dentry);
 		dentry = ERR_PTR(error);
 	}
+
 	return dentry;
 }
 

@@ -4573,6 +4587,7 @@ static struct dentry *lookup_open(struct nameidata *nd, struct file *file,
 			dentry = res;
 		}
 	}
+
 	if (dentry->d_inode || !(op->open_flag & O_CREAT)) {
 		/*
 		 * No need to create a file.  If lookup returned a positive

@@ -5387,6 +5402,33 @@ SYSCALL_DEFINE3(mknod, const char __user *, filename, umode_t, mode, unsigned, d
 	return filename_mknodat(AT_FDCWD, name, mode, dev);
 }
 
+static inline
+struct dentry *vfs_mkdir_no_perm(struct mnt_idmap *idmap, struct inode *dir,
+				 struct dentry *dentry, umode_t mode,
+				 struct delegated_inode *di)
+{
+	unsigned max_links = dir->i_sb->s_max_links;
+	struct dentry *de;
+	int error;
+
+	if (max_links && dir->i_nlink >= max_links)
+		return ERR_PTR(-EMLINK);
+
+	error = try_break_deleg(dir, LEASE_BREAK_DIR_CREATE, di);
+	if (error)
+		return ERR_PTR(error);
+
+	de = dir->i_op->mkdir(idmap, dir, dentry, mode);
+	if (IS_ERR(de))
+		return de;
+	if (de) {
+		dput(dentry);
+		dentry = de;
+	}
+	fsnotify_mkdir(dir, dentry);
+	return dentry;
+}
+
 /**
  * vfs_mkdir - create directory returning correct dentry if possible
  * @idmap:		idmap of the mount the inode was found from

@@ -5414,7 +5456,6 @@ struct dentry *vfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 			 struct delegated_inode *delegated_inode)
 {
 	int error;
-	unsigned max_links = dir->i_sb->s_max_links;
 	struct dentry *de;
 
 	error = may_create_dentry(idmap, dir, dentry);

@@ -5430,24 +5471,12 @@ struct dentry *vfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 	if (error)
 		goto err;
 
-	error = -EMLINK;
-	if (max_links && dir->i_nlink >= max_links)
-		goto err;
-
-	error = try_break_deleg(dir, LEASE_BREAK_DIR_CREATE, delegated_inode);
-	if (error)
+	de = vfs_mkdir_no_perm(idmap, dir, dentry, mode, delegated_inode);
+	if (IS_ERR(de)) {
+		error = PTR_ERR(de);
 		goto err;
-
-	de = dir->i_op->mkdir(idmap, dir, dentry, mode);
-	error = PTR_ERR(de);
-	if (IS_ERR(de))
-		goto err;
-	if (de) {
-		dput(dentry);
-		dentry = de;
 	}
-	fsnotify_mkdir(dir, dentry);
-	return dentry;
+	return de;
 
 err:
 	end_creating(dentry);