[pnfs] [PATCH 1/3] pnfs-gfs2: initial LAYOUT* work for pNFS/GFS2 integration

[david m. richter]

	thanks for the fixups, dean :)  i had been wondering if/how the 
"numDests" that we saw in cxiSystem.c was going to affect making the 
layout filehandles in the gfs2 world, but you took care of that nicely.

	thanks!

On Thu, 29 May 2008, Dean Hildebrand wrote:

> 
> 
> David M. Richter wrote:
> > Frank Filz's work on the layout_type() and layout_get() export operations,
> > with stubs for layout_commit() and layout_return().  Tested at Connectathon.
> > 
> > Signed-off-by: Frank Filz <ffilzlnx at us.ibm.com>
> > Signed-off-by: David M. Richter <richterd at citi.umich.edu>
> > ---
> >  fs/gfs2/ops_export.c |  109
> > ++++++++++++++++++++++++++++++++++++++++++++++++++
> >  1 files changed, 109 insertions(+), 0 deletions(-)
> > 
> > diff --git a/fs/gfs2/ops_export.c b/fs/gfs2/ops_export.c
> > index 334c7f8..b62cc66 100644
> > --- a/fs/gfs2/ops_export.c
> > +++ b/fs/gfs2/ops_export.c
> > @@ -27,6 +27,16 @@
> >  #include "rgrp.h"
> >  #include "util.h"
> >  +#if defined(CONFIG_PNFSD)
> > +#include <linux/nfs_fs.h>
> > +#include <linux/sunrpc/svc.h>
> > +#include <linux/nfsd/state.h>
> > +#include <linux/nfsd/nfsfh.h>
> > +#include <linux/nfsd/pnfsd.h>
> > +#include <linux/nfsd/nfs4layoutxdr.h>
> > +#include <linux/nfs4_pnfs.h>
> > +#endif /* CONFIG_PNFSD */
> > +
> >  #define GFS2_SMALL_FH_SIZE 4
> >  #define GFS2_LARGE_FH_SIZE 8
> >  #define GFS2_OLD_FH_SIZE 10
> > @@ -294,11 +304,110 @@ static struct dentry *gfs2_fh_to_parent(struct
> > super_block *sb, struct fid *fid,
> >  	}
> >  }
> >  +#if defined(CONFIG_PNFSD)
> > +static int gfs2_layout_type(void)
> > +{
> > +	return LAYOUT_NFSV4_FILES;
> > +}
> > +
> > +/* like GPFS does, use a multiple of the underlying fs' blocksize */
> >   
> no so important now, but in the long run I'd remove any mention of gpfs.
> > +static int get_stripe_unit(int blocksize)
> > +{
> > +	if (blocksize >= NFSSVC_MAXBLKSIZE)
> > +		return blocksize;
> > +
> > +	return NFSSVC_MAXBLKSIZE - NFSSVC_MAXBLKSIZE % blocksize;
> >   
> I would add () just to make sure it is clear.
> > +}
> > +
> > +/*
> > + * Retrieve and encode a file layout onto the xdr stream.
> > + * @inode: inode for which to retrieve layout
> > + * @arg->xdr: xdr stream for encoding
> > + * @arg->func: a call into file system to encode the layout on xdr stream.
> > + */
> > +static int gfs2_layout_get(struct inode *inode, struct pnfs_layoutget_arg
> > *arg)
> > +{
> > +	int i, rc = 0;
> > +	int num_dests = 1; /* XXX: revisit */
> > +	struct pnfs_filelayout_layout *layout = NULL;
> > +	struct knfsd_fh *fh_list = NULL;
> > +
> > +	printk(KERN_DEBUG "%s: LAYOUT_GET\n", __func__);
> > +
> > +	/* Set layout indept response args */
> > +	arg->seg.layout_type = LAYOUT_NFSV4_FILES;
> > +	arg->seg.offset = 0;
> > +	arg->seg.length = inode->i_sb->s_maxbytes; /* The maximum file size */
> > +
> > +	layout = kzalloc(sizeof(*layout), GFP_KERNEL);
> > +	if (layout == NULL) {
> > +		rc = -ENOMEM;
> > +		goto error;
> > +	}
> > +
> > +	/* Set file layout response args */
> > +	layout->lg_layout_type = LAYOUT_NFSV4_FILES;
> > +	layout->lg_stripe_type = STRIPE_SPARSE;
> > +	layout->lg_commit_through_mds = true;
> > +	layout->lg_stripe_unit = get_stripe_unit(inode->i_sb->s_blocksize);
> > +	layout->lg_fh_length = num_dests;
> > +	layout->device_id.pnfs_fsid = arg->fsid;
> > +	layout->device_id.pnfs_devid = 1;			/*FSFTEMP*/
> > +	layout->lg_first_stripe_index = 0;			/*FSFTEMP*/
> > +	layout->lg_pattern_offset = 0;
> > +
> > +	fh_list = kmalloc(sizeof(*fh_list) * num_dests, GFP_KERNEL);
> > +	if (fh_list == NULL) {
> > +		rc = -ENOMEM;
> > +		goto error;
> > +	}
> > +
> > +	memcpy(&fh_list[0], arg->fh, sizeof(*fh_list));
> > +	pnfs_fh_mark_ds(&fh_list[0]);
> > +
> > +	if (num_dests > 1)
> > +		for (i = 1; i < num_dests; i++)
> > +			memcpy(&fh_list[i], &fh_list[0], sizeof(*fh_list));
> >   
> We just noticed this in gpfs, but we only need to set 1 file handle.
> 
> from draft23:
> nfl_fh_list: An array of data server filehandles for each list of data servers
> in each element of the nflda_multipath_ds_list array. The number of elements
> in nfl_fh_list depends on whether sparse or dense packing is being used.
> 
>    * If sparse packing is being used, the number of elements in
>      nfl_fh_list MUST be one of three values:
>          o Zero. This means that filehandles used for each data server
>            are the same as the filehandle returned by the OPEN
>            operation from the metadata server.
>          o One. This means that every data server uses the same
>            filehandle: what is specified in nfl_fh_list[0].
>          o The same number of elements in nflda_multipath_ds_list.
>            Thus, in this case, when issuing an I/O to any data server
>            in nflda_multipath_ds_list[X], the filehandle in
>            nfl_fh_list[X] MUST be used.
> 
> 
> > +	layout->lg_fh_list = fh_list;
> > +
> > +	/* Call nfsd to encode layout */
> > +	rc = arg->func(&arg->xdr, layout);
> > +exit:
> > +	kfree(layout);
> > +	kfree(fh_list);
> > +	return rc;
> > +
> > +error:
> > +	arg->seg.length = 0;
> > +	goto exit;
> > +}
> > +
> > +static int gfs2_layout_commit(struct inode *inode, void *p)
> > +{
> > +	printk(KERN_DEBUG "%s: LAYOUT_COMMIT (unimplemented)\n", __func__);
> > +
> > +	return 0;
> > +}
> > +
> > +static int gfs2_layout_return(struct inode *inode, void *p)
> > +{
> > +	printk(KERN_DEBUG "%s: LAYOUT_RETURN (unimplemented)\n", __func__);
> > +
> > +	return 0;
> > +}
> > +#endif /* CONFIG_PNFSD */
> > +
> >  const struct export_operations gfs2_export_ops = {
> >  	.encode_fh = gfs2_encode_fh,
> >  	.fh_to_dentry = gfs2_fh_to_dentry,
> >  	.fh_to_parent = gfs2_fh_to_parent,
> >  	.get_name = gfs2_get_name,
> >  	.get_parent = gfs2_get_parent,
> > +#if defined(CONFIG_PNFSD)
> > +	.layout_type = gfs2_layout_type,
> > +	.layout_get = gfs2_layout_get,
> > +	.layout_commit = gfs2_layout_commit,
> > +	.layout_return = gfs2_layout_return,
> > +#endif /* CONFIG_PNFSD */
> >  };
> >