linux/fs/nfs/blocklayout/blocklayout.c

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/*
* linux/fs/nfs/blocklayout/blocklayout.c
*
* Module for the NFSv4.1 pNFS block layout driver.
*
* Copyright (c) 2006 The Regents of the University of Michigan.
* All rights reserved.
*
* Andy Adamson <andros@citi.umich.edu>
* Fred Isaman <iisaman@umich.edu>
*
* 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 from the
* university of michigan as to its fitness for any purpose, and without
* warranty by the university of michigan of any kind, either express
* or implied, including without limitation the implied warranties of
* merchantability and fitness for a particular purpose. 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 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/module.h>
#include <linux/init.h>
#include "blocklayout.h"
#define NFSDBG_FACILITY NFSDBG_PNFS_LD
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Andy Adamson <andros@citi.umich.edu>");
MODULE_DESCRIPTION("The NFSv4.1 pNFS Block layout driver");
static enum pnfs_try_status
bl_read_pagelist(struct nfs_read_data *rdata)
{
return PNFS_NOT_ATTEMPTED;
}
static enum pnfs_try_status
bl_write_pagelist(struct nfs_write_data *wdata,
int sync)
{
return PNFS_NOT_ATTEMPTED;
}
/* FIXME - range ignored */
static void
release_extents(struct pnfs_block_layout *bl, struct pnfs_layout_range *range)
{
int i;
struct pnfs_block_extent *be;
spin_lock(&bl->bl_ext_lock);
for (i = 0; i < EXTENT_LISTS; i++) {
while (!list_empty(&bl->bl_extents[i])) {
be = list_first_entry(&bl->bl_extents[i],
struct pnfs_block_extent,
be_node);
list_del(&be->be_node);
bl_put_extent(be);
}
}
spin_unlock(&bl->bl_ext_lock);
}
/* STUB */
static void
release_inval_marks(struct pnfs_inval_markings *marks)
{
return;
}
static void bl_free_layout_hdr(struct pnfs_layout_hdr *lo)
{
struct pnfs_block_layout *bl = BLK_LO2EXT(lo);
dprintk("%s enter\n", __func__);
release_extents(bl, NULL);
release_inval_marks(&bl->bl_inval);
kfree(bl);
}
static struct pnfs_layout_hdr *bl_alloc_layout_hdr(struct inode *inode,
gfp_t gfp_flags)
{
struct pnfs_block_layout *bl;
dprintk("%s enter\n", __func__);
bl = kzalloc(sizeof(*bl), gfp_flags);
if (!bl)
return NULL;
spin_lock_init(&bl->bl_ext_lock);
INIT_LIST_HEAD(&bl->bl_extents[0]);
INIT_LIST_HEAD(&bl->bl_extents[1]);
INIT_LIST_HEAD(&bl->bl_commit);
INIT_LIST_HEAD(&bl->bl_committing);
bl->bl_count = 0;
bl->bl_blocksize = NFS_SERVER(inode)->pnfs_blksize >> SECTOR_SHIFT;
BL_INIT_INVAL_MARKS(&bl->bl_inval, bl->bl_blocksize);
return &bl->bl_layout;
}
static void
bl_free_lseg(struct pnfs_layout_segment *lseg)
{
}
static struct pnfs_layout_segment *
bl_alloc_lseg(struct pnfs_layout_hdr *lo,
struct nfs4_layoutget_res *lgr, gfp_t gfp_flags)
{
return NULL;
}
static void
bl_encode_layoutcommit(struct pnfs_layout_hdr *lo, struct xdr_stream *xdr,
const struct nfs4_layoutcommit_args *arg)
{
}
static void
bl_cleanup_layoutcommit(struct nfs4_layoutcommit_data *lcdata)
{
}
static int
bl_set_layoutdriver(struct nfs_server *server, const struct nfs_fh *fh)
{
dprintk("%s enter\n", __func__);
return 0;
}
static int
bl_clear_layoutdriver(struct nfs_server *server)
{
dprintk("%s enter\n", __func__);
return 0;
}
static const struct nfs_pageio_ops bl_pg_read_ops = {
.pg_init = pnfs_generic_pg_init_read,
.pg_test = pnfs_generic_pg_test,
.pg_doio = pnfs_generic_pg_readpages,
};
static const struct nfs_pageio_ops bl_pg_write_ops = {
.pg_init = pnfs_generic_pg_init_write,
.pg_test = pnfs_generic_pg_test,
.pg_doio = pnfs_generic_pg_writepages,
};
static struct pnfs_layoutdriver_type blocklayout_type = {
.id = LAYOUT_BLOCK_VOLUME,
.name = "LAYOUT_BLOCK_VOLUME",
.read_pagelist = bl_read_pagelist,
.write_pagelist = bl_write_pagelist,
.alloc_layout_hdr = bl_alloc_layout_hdr,
.free_layout_hdr = bl_free_layout_hdr,
.alloc_lseg = bl_alloc_lseg,
.free_lseg = bl_free_lseg,
.encode_layoutcommit = bl_encode_layoutcommit,
.cleanup_layoutcommit = bl_cleanup_layoutcommit,
.set_layoutdriver = bl_set_layoutdriver,
.clear_layoutdriver = bl_clear_layoutdriver,
.pg_read_ops = &bl_pg_read_ops,
.pg_write_ops = &bl_pg_write_ops,
};
static int __init nfs4blocklayout_init(void)
{
int ret;
dprintk("%s: NFSv4 Block Layout Driver Registering...\n", __func__);
ret = pnfs_register_layoutdriver(&blocklayout_type);
return ret;
}
static void __exit nfs4blocklayout_exit(void)
{
dprintk("%s: NFSv4 Block Layout Driver Unregistering...\n",
__func__);
pnfs_unregister_layoutdriver(&blocklayout_type);
}
MODULE_ALIAS("nfs-layouttype4-3");
module_init(nfs4blocklayout_init);
module_exit(nfs4blocklayout_exit);