linux/fs/nfs/filelayout/filelayoutdev.c

/*
 *  Device operations for the pnfs nfs4 file layout driver.
 *
 *  Copyright (c) 2002
 *  The Regents of the University of Michigan
 *  All Rights Reserved
 *
 *  Dean Hildebrand <[email protected]>
 *  Garth Goodson   <[email protected]>
 *
 *  Permission is granted to use, copy, create derivative works, and
 *  redistribute this software and such derivative works for any purpose,
 *  so long as the name of the University of Michigan is not used in
 *  any advertising or publicity pertaining to the use or distribution
 *  of this software without specific, written prior authorization. If
 *  the above copyright notice or any other identification of the
 *  University of Michigan is included in any copy of any portion of
 *  this software, then the disclaimer below must also be included.
 *
 *  This software is provided as is, without representation or warranty
 *  of any kind either express or implied, including without limitation
 *  the implied warranties of merchantability, fitness for a particular
 *  purpose, or noninfringement.  The Regents of the University of
 *  Michigan shall not be liable for any damages, including special,
 *  indirect, incidental, or consequential damages, with respect to any
 *  claim arising out of or in connection with the use of the software,
 *  even if it has been or is hereafter advised of the possibility of
 *  such damages.
 */

#include <linux/nfs_fs.h>
#include <linux/vmalloc.h>
#include <linux/module.h>

#include "../internal.h"
#include "../nfs4session.h"
#include "filelayout.h"
#include "../nfs4trace.h"

#define NFSDBG_FACILITY …

static unsigned int dataserver_timeo = …;
static unsigned int dataserver_retrans = …;

void
nfs4_fl_free_deviceid(struct nfs4_file_layout_dsaddr *dsaddr)
{ … }

/* Decode opaque device data and return the result */
struct nfs4_file_layout_dsaddr *
nfs4_fl_alloc_deviceid_node(struct nfs_server *server, struct pnfs_device *pdev,
		gfp_t gfp_flags)
{ … }

void
nfs4_fl_put_deviceid(struct nfs4_file_layout_dsaddr *dsaddr)
{ … }

/*
 * 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)
{ … }

u32
nfs4_fl_calc_ds_index(struct pnfs_layout_segment *lseg, u32 j)
{ … }

struct nfs_fh *
nfs4_fl_select_ds_fh(struct pnfs_layout_segment *lseg, u32 j)
{ … }

/* Upon return, either ds is connected, or ds is NULL */
struct nfs4_pnfs_ds *
nfs4_fl_prepare_ds(struct pnfs_layout_segment *lseg, u32 ds_idx)
{ … }

module_param(dataserver_retrans, uint, 0644);
MODULE_PARM_DESC(…) …;
module_param(dataserver_timeo, uint, 0644);
MODULE_PARM_DESC(…) …;