Ext2 descriptor corruption in 2.4.0

[Daniel Phillips]

After 3 days up doing fairly normal things with an unremarkable
configuration and a vanila 2.4.0 kernel (nfs) I tried to log out of KDE 
and hung in 'preparing session for logout'.  In a text console, dmesg
showed an infinite number of "Free blocks count corrupted" messages:

  EXT2-fs error (device ide0(3,66)): ext2_new_block: Free blocks count
corrupted for block group 93
  EXT2-fs error (device ide0(3,66)): ext2_new_block: Free blocks count
corrupted for block group 93                                             

and gdb showed all the processes under X waiting in poll or select, not
surprising considering the way ext2 handles this:

  if (j >= EXT2_BLOCKS_PER_GROUP(sb)) {
         ext2_error (sb, "ext2_new_block",
                     "Free blocks count corrupted for block group %d",
i);
         goto out;
  }

I shut down and restarted hoping to get an fsck, but instead continued
past the ext2 mount.  I interrupted that, restarted and fscked, which
turned up a single special file with size 0 and no other problems.

So I think this may be a cache problem.

--
Daniel