Re: NTFS file system driver (update 3)

[Bean]

On 7/31/07, Marco Gerards <address@hidden> wrote:
> Bean <address@hidden> writes:
>
> > On Mon, Jul 30, 2007 at 01:19:32PM +0200, Marco Gerards wrote:
> >> Can you pass it around inside one of the structs?  I understand that
> >> passing it around as parameter is not really nice.  The problem is
> >> that this might actually break other code, which I want to prevent.  I
> >> hope you see this might become a serious problem?
> >
> > Ok, I pass the hook around using parameter, please see if there is other
> > problem.
>
> It looks like you still use the read hook, as in you change the read
> hook of the disk, am I right?  With passing "it" around I meant some
> hook, not the disk-> hook.  Because this is more like a higher level
> function, using this in the filesystem has some problems like I will
> describe below.
>
> I noticed in your other email that you were playing with the blocklist
> command.  Did you check if the blocklist that is returned by the
> blocklist command is *exactly* as it is supposed to be?  So that no
> blocks are missing or added because of your code?
>
> My main problem is this...  You do not need a hook for this.  Can you
> please in detail describe what the hook is supposed to do?  The main
> reason why I ask about this is that you do not need the hook *at all*.
> It makes the code very hard to understand and I am, as you noticed,
> afraid that it might break the blocklist feature.
>
> If you need a block number for certain data, you can better make a
> function to calculate the block number somehow.  Or store it, or
> whatever.  I am sure you would use something like this if there was no
> hook, so can't you just pretend that this hook does not exist?
>
> If something is not clear yet, feel free to ask me.  My problem is
> that I can not fully understand the code yet.  But if you show me
> where to look and tell me what certain things do, I am certainly
> willing to invest some time in this.

I believe disk hook is ok, as in grub_fshelp_read_file:

if (blknr)
        {
          disk->read_hook = read_hook;

          grub_disk_read (disk, blknr, skipfirst,
                          blockend, buf);
          disk->read_hook = 0;
          if (grub_errno)
            return -1;
        }

grub_disk_read will call the hook when it's appropriate.

btw, The blocklist command works for files in ntfs partition.

-- 
Bean