"Paintings on walls and ceilings" and "painting of portraits, landscapes"
Solution 1:
They are called murals.
A mural is any piece of artwork painted or applied directly on a wall, ceiling or other large permanent surface. A particularly distinguishing characteristic of mural painting is that the architectural elements of the given space are harmoniously incorporated into the picture.
Solution 2:
The word you are looking for is mural, which per the OED is
A painting executed on a wall or ceiling as part of a scheme of decoration.
Etymology: a. Fr. muraille: Com. Rom. muralia (repr. L. mūrālia neut. pl. of mūrālis mural a., taken as fem. sing.: see -al1 5); cf. Sp. muralla, Pg. muralha, Ital. muraglia; also OFr. murail, Pr. muralh masc.