Should mdxxx functions(e.g. mdread, mdwrite, mdsync etc) PANIC instead of ERROR when I/O failed?

  Recently, when I was running my application on 8.3.7, my data got 
corrupted. The scene was like this: "invalid memory alloc request size ...."
 I invested the error data, and found that one sector of a db-block became 
all-zero (I confirmed the reason later, it  was because that my disk got 
bad).
 I also checked the log of postmaster, and I found that there were 453 
ERROR messages that said "could not read block XXX of relation XXX: ??", 
where XXX was the db-block that the bad sector resided in. After these 453 
failed read operations, postmaster read successed, but got an all-zero 
sector! (I don't know why operating system will allow this happen, but it 
just happened)
 My question is: should not mdxxx functions(e.g. mdread, mdwrite, mdsync) 
just report PANIC instead of ERROR when I/O failed? IMO, since the data has 
already corrupted, reporting ERROR will just leave us a very curious scene 
later -- which does more harm that benefit.