How does one map physical sectors of a disk to the files that contain them on an HFS+ volume on Mac OS X

Question

I've been recovering a hard disk using dd_rescue, which provides me a list of all of the device sectors it could not copy due to hardware errors.

I'd like to take that list, and write a tool to give me all of the files that contain these bad sectors so I can delete them. I'm not sure what APIs I can use to do this--essentially i want to get a list of all files on disk and for each file, a list of the ranges of sectors it occupies on disk.

My first guess is that I will iterate over each directory entry on the disk and check to see if the file overlaps one of these bad sectors. Maybe there's a better way.

Answer 1

There's no API exposed for grubbing through HFS+ filesystems, but the source for the filesystem is available from Apple as part of the XNU kernel. Also check out the hfsdebug tool which might help to understand the fs.