[syslinux] [RFC] COMBOOT: readdir: st_mode or d_type

[Gene Cumm]

On Tue, Mar 3, 2009 at 2:48 PM, Thomas Schmitt <scdbackup at gmx.net> wrote:
> Hi,
>
> Gene Cumm wrote:
>> The most important thing to return is the filename.
>> ISO9660 dirents contain name, size, type and any other attributes.
>
> ISO 9660 filenames are quite mediocre.
> The attributes of ISO 9660 (aka ECMA-119) do not
> match well with struct stat.

But the basic types can at least be made to fit through mapping, from
what I can see.  Same with FAT.

> If you plan to follow the default behavior of
> mounted ISO 9660 on e.g. Linux then you will be
> interested in eventual Rock Ridge entries which
> give long name, stat(2) attributes, symbolic link
> target.

Hmm.. not to ISOLINUX yet but my goal would be to duplicate the
functionality that searchdir provides in readdir as far as the name
and such.

>> [...] in the case of a cache miss.
>
> The Rock Ridge entries may be larger than the
> System Use Area in the ISO directory entry.
> In that case they are continued in a data block
> outside the directory entry (Continuation Area,
> pointed to by SUSP entry CE).
> This redirection makes cache misses more likely.
> Expect at least two groups of read positions which
> are used frequently and are several hundred KB apart.

Ouch.  That'll do a nice job on performance

> libisoburn shows sufficient performance with
> 16 cache tiles of 128 kB each. But we have of
> course a different situation when we load a tree
> of 1e5 files into memory. I assume you mainly
> expect trees of a few hundred files. At least that's
> what i see with bootable CD or DVD.
>
>
> Have a nice day :)

So far so good.

-- 
-Gene