Jan Harkes wrote:
: > Every file on the front filesystem (NFS or so) volume will be cached
: > in two local files by cachefsd: The first one would contain the (parts of)
: > real file content, and the second one would contain file's metadata and the
: > bitmap of valid blocks (or pages) of the first file. All files in cachefsd's
: > backing store would be in a per-volume directory, and will be numbered by the
: > inode number from the front filesystem.
:
: - Intermezzo uses 'holes' in files to indicate that content isn't
: available.
Well, but can you see the hole from the user-space daemon?
: - You might want to have a more hierarchical backing store, directory
: operations in large directories are not very efficient.
Yes, of course. But this is an implementation detail of cachefsd.
: - I believe you are switching the meaning of front and backend
: filesystems around a lot in your description. Who exactly assigns the
: inode numbers?
Well, let's speak about NFS, locally cached on ext2. The present
implemetation takes inode number from NFS, and creates and ext2 file
named - for example - /cache/%d (for file contents) and /cache/%d.attr for
stat(2) data and valid blocks bitmap. The %d is an inode number from the
NFS volume.
: Some references,
:
: UserFS, PodFuk, AVFS,
Thanks,
-Yenya
-- \ Jan "Yenya" Kasprzak <kas at fi.muni.cz> http://www.fi.muni.cz/~kas/ \\ PGP: finger kas at aisa.fi.muni.cz 0D99A7FB206605D7 8B35FCDE05B18A5E // \\\ Czech Linux Homepage: http://www.linux.cz/ /// It is a very bad idea to feed negative numbers to memcpy. --Alan Cox - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
This archive was generated by hypermail 2b29 : Fri Jun 15 2001 - 21:00:09 EST