[Cluster-devel] [PATCH 1/2] gfs2: Extended attribute readahead

[Bob Peterson <rpeterso@redhat.com>]

----- Original Message -----
> When gfs2 allocates an inode and its extended attribute block next to
> each other at inode create time, the inode's directory entry indicates
> that in de_rahead.  In that case, we can readahead the extended
> attribute block when we read in the inode.
> 
> Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
> ---
>  fs/gfs2/dir.c     | 15 +++++++++++----
>  fs/gfs2/incore.h  |  1 +
>  fs/gfs2/meta_io.c | 27 +++++++++++++++++++++++++--
>  fs/gfs2/meta_io.h |  2 +-
>  fs/gfs2/quota.c   |  2 +-
>  fs/gfs2/rgrp.c    |  2 +-
>  fs/gfs2/super.c   |  1 +
>  fs/gfs2/xattr.c   | 10 +++++-----
>  8 files changed, 46 insertions(+), 14 deletions(-)
> 

Hi Andreas,

Most of this looks good. However, two comments:

1. I don't like adding a new u16 to the gfs2_inode. I've been working to
   reduce the size of gfs2's inodes lately, so I'd rather see this
   implemented as a new GIF_RAHEAD (or similar) flag in gfs2_inode's i_flags.
2. It seems to me like we should take advantage of function gfs2_meta_ra()
   which already submits one block and a variable number of additional
   blocks for read-ahead, then waits for the first block IO to complete.

Regards,

Bob Peterson
Red Hat File Systems