[I'm not subscribed to the darwin-development or studentdev lists; I'm not sure this cross-posting is really appropriate.]
On Monday, May 6, 2002, at 03:53 AM, Entwicklung wrote:
I'd like to know if anyone who has used hfsutils in the pastknows upto what allocation block size it supports for reading. I have an allocation block size of 64kB and I'm unable to mount my hfs-volume. It is slightly larger than 2GB in size. Images of size 32MB, 64MB upto 512MB, 1GB and < 2GB seem to work fine.
I get the following error : Sorry, unable to mount volume. Read unallocated block (Input/Output error).
Does anybody know if hfsutils imposes a restriction on allocation block size or this error is due to some bug in my program ? What could possibly be causing this ?
It is not the allocation block size but the total volume size which is likely to give hfsutils problems. Volumes >= 2GB require byte seek offsets to be represented with at least 32 unsigned bits, a condition that presents a problem on platforms where lseek() accepts a signed 32-bit offset.
It's possible hfsutils could be changed to support volumes >= 2GB. Since hfsutils reads and writes using physical block (512-byte) addresses, perhaps even a simple cast in the call to lseek() would provide the required support on platforms where off_t is larger than 32 bits.
-- Rob Leslie rob@mars.org