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Commit cfe7f412 authored by Fred Isaman's avatar Fred Isaman Committed by Trond Myklebust
Browse files

NFSv4.1: filelayout i/o helpers 



Prepare for filelayout_read_pagelist with helper functions that find the correct
data server, filehandle, and offset.

Signed-off-by: default avatarAndy Adamson <andros@citi.umich.edu>
Signed-off-by: default avatarDean Hildebrand <dhildeb@us.ibm.com>
Signed-off-by: default avatarFred Isaman <iisaman@netapp.com>
Signed-off-by: default avatarMarc Eshel <eshel@almaden.ibm.com>
Signed-off-by: default avatarMike Sager <sager@netapp.com>
Signed-off-by: default avatarOleg Drokin <green@linuxhacker.ru>
Signed-off-by: default avatarTao Guo <guotao@nrchpc.ac.cn>
Signed-off-by: default avatarTigran Mkrtchyan <tigran@anahit.desy.de>
Signed-off-by: default avatarTigran Mkrtchyan <tigran.mkrtchyan@desy.de>
Signed-off-by: default avatarAndy Adamson <andros@netapp.com>
Signed-off-by: default avatarBenny Halevy <bhalevy@panasas.com>
Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
parent d83217c1

fs/nfs/nfs4filelayout.c

+34 −0
Original line number Diff line number Diff line
@@ -66,6 +66,40 @@ filelayout_clear_layoutdriver(struct nfs_server *nfss) 
	return 0;

}



static loff_t

filelayout_get_dense_offset(struct nfs4_filelayout_segment *flseg,

			    loff_t offset)

{

	u32 stripe_width = flseg->stripe_unit * flseg->dsaddr->stripe_count;

	u64 tmp;



	offset -= flseg->pattern_offset;

	tmp = offset;

	do_div(tmp, stripe_width);



	return tmp * flseg->stripe_unit + do_div(offset, flseg->stripe_unit);

}



/* This function is used by the layout driver to calculate the

 * offset of the file on the dserver based on whether the

 * layout type is STRIPE_DENSE or STRIPE_SPARSE

 */

static loff_t

filelayout_get_dserver_offset(struct pnfs_layout_segment *lseg, loff_t offset)

{

	struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);



	switch (flseg->stripe_type) {

	case STRIPE_SPARSE:

		return offset;



	case STRIPE_DENSE:

		return filelayout_get_dense_offset(flseg, offset);

	}



	BUG();

}



/*

 * filelayout_check_layout()

 *

fs/nfs/nfs4filelayout.h

+7 −0
Original line number Diff line number Diff line
@@ -83,9 +83,16 @@ FILELAYOUT_LSEG(struct pnfs_layout_segment *lseg) 
			    generic_hdr);

}



extern struct nfs_fh *

nfs4_fl_select_ds_fh(struct pnfs_layout_segment *lseg, u32 j);



extern void nfs4_fl_free_deviceid_callback(struct pnfs_deviceid_node *);

extern void print_ds(struct nfs4_pnfs_ds *ds);

extern void print_deviceid(struct nfs4_deviceid *dev_id);

u32 nfs4_fl_calc_j_index(struct pnfs_layout_segment *lseg, loff_t offset);

u32 nfs4_fl_calc_ds_index(struct pnfs_layout_segment *lseg, u32 j);

struct nfs4_pnfs_ds *nfs4_fl_prepare_ds(struct pnfs_layout_segment *lseg,

					u32 ds_idx);

extern struct nfs4_file_layout_dsaddr *

nfs4_fl_find_get_deviceid(struct nfs_client *, struct nfs4_deviceid *dev_id);

struct nfs4_file_layout_dsaddr *

fs/nfs/nfs4filelayoutdev.c

+67 −0
Original line number Diff line number Diff line
@@ -516,3 +516,70 @@ nfs4_fl_find_get_deviceid(struct nfs_client *clp, struct nfs4_deviceid *id) 
	return (d == NULL) ? NULL :

		container_of(d, struct nfs4_file_layout_dsaddr, deviceid);

}



/*

 * Want res = (offset - layout->pattern_offset)/ layout->stripe_unit

 * Then: ((res + fsi) % dsaddr->stripe_count)

 */

u32

nfs4_fl_calc_j_index(struct pnfs_layout_segment *lseg, loff_t offset)

{

	struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);

	u64 tmp;



	tmp = offset - flseg->pattern_offset;

	do_div(tmp, flseg->stripe_unit);

	tmp += flseg->first_stripe_index;

	return do_div(tmp, flseg->dsaddr->stripe_count);

}



u32

nfs4_fl_calc_ds_index(struct pnfs_layout_segment *lseg, u32 j)

{

	return FILELAYOUT_LSEG(lseg)->dsaddr->stripe_indices[j];

}



struct nfs_fh *

nfs4_fl_select_ds_fh(struct pnfs_layout_segment *lseg, u32 j)

{

	struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);

	u32 i;



	if (flseg->stripe_type == STRIPE_SPARSE) {

		if (flseg->num_fh == 1)

			i = 0;

		else if (flseg->num_fh == 0)

			/* Use the MDS OPEN fh set in nfs_read_rpcsetup */

			return NULL;

		else

			i = nfs4_fl_calc_ds_index(lseg, j);

	} else

		i = j;

	return flseg->fh_array[i];

}



struct nfs4_pnfs_ds *

nfs4_fl_prepare_ds(struct pnfs_layout_segment *lseg, u32 ds_idx)

{

	struct nfs4_file_layout_dsaddr *dsaddr = FILELAYOUT_LSEG(lseg)->dsaddr;

	struct nfs4_pnfs_ds *ds = dsaddr->ds_list[ds_idx];



	if (ds == NULL) {

		printk(KERN_ERR "%s: No data server for offset index %d\n",

			__func__, ds_idx);

		return NULL;

	}



	if (!ds->ds_clp) {

		int err;



		err = nfs4_ds_connect(NFS_SERVER(lseg->pls_layout->plh_inode),

					  dsaddr->ds_list[ds_idx]);

		if (err) {

			printk(KERN_ERR "%s nfs4_ds_connect error %d\n",

			       __func__, err);

			return NULL;

		}

	}

	return ds;

}