Well, lets go over it (formula's taken from here):
1st pre-image resistance: For a given $h$ in the output space of the hash function, it is hard to find any message $x$ with $H(x) = h$.
That's not it, as you will only store hashes created over some specific data, the value $h$ cannot be just any value, it is created over some file data. I presume that an adversary cannot just put any hash value in your database without providing a file.
2nd pre-image resistance: For a given message $x_1$ it is hard to find a second message $x_2 \neq x_1$ with $H(x_1) = H(x_2)$.
Well, that's it really. You have a specific file and you don't want to have another file have the same hash.
You still cannot do this for data using MD5 and SHA-1 unless that data was structured specially for this purpose. If you have a file that was not specifically created or altered then you will not find a collision using the currently known attacks.
Collision resistance: It is hard to find a pair of messages $x_1 \neq x_2$ with $H(x_1) = H(x_2)$.
This comes into the picture if an adversary can inject values in your file database. Say the adversary has a collision then somebody can load a file with the data $x_1$ that created the collision to your file system. You would not notice any change from the hash if it would be replaced by $x_2$.
As there are collisions known for MD5 and SHA-1 they are completely vulnerable to this attack. You can just upload a file containing the data required for the collision.
With MD5 it is even easy to create these collisions, using any kind of data as starting value. For SHA-1 you could use one of the demo PDF's, but creating a collision yourself will require a lot of computing power.
Generally salts are not used when comparing files, so I take that part out of the question if you don't mind.