path: root/fs/nfs/objlayout/objio_osd.c

/*
 *  pNFS Objects layout implementation over open-osd initiator library
 *
 *  Copyright (C) 2009 Panasas Inc. [year of first publication]
 *  All rights reserved.
 *
 *  Benny Halevy <bhalevy@panasas.com>
 *  Boaz Harrosh <bharrosh@panasas.com>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2
 *  See the file COPYING included with this distribution for more details.
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions
 *  are met:
 *
 *  1. Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *  2. Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *  3. Neither the name of the Panasas company nor the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
 *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
 *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <linux/module.h>
#include <scsi/osd_ore.h>

#include "objlayout.h"

#define NFSDBG_FACILITY         NFSDBG_PNFS_LD

#define _LLU(x) ((unsigned long long)x)

enum { BIO_MAX_PAGES_KMALLOC =
		(PAGE_SIZE - sizeof(struct bio)) / sizeof(struct bio_vec),
};

struct objio_dev_ent {
	struct nfs4_deviceid_node id_node;
	struct ore_dev od;
};

static void
objio_free_deviceid_node(struct nfs4_deviceid_node *d)
{
	struct objio_dev_ent *de = container_of(d, struct objio_dev_ent, id_node);

	dprintk("%s: free od=%p\n", __func__, de->od.od);
	osduld_put_device(de->od.od);
	kfree(de);
}

static struct objio_dev_ent *_dev_list_find(const struct nfs_server *nfss,
	const struct nfs4_deviceid *d_id)
{
	struct nfs4_deviceid_node *d;
	struct objio_dev_ent *de;

	d = nfs4_find_get_deviceid(nfss->pnfs_curr_ld, nfss->nfs_client, d_id);
	if (!d)
		return NULL;

	de = container_of(d, struct objio_dev_ent, id_node);
	return de;
}

static struct objio_dev_ent *
_dev_list_add(const struct nfs_server *nfss,
	const struct nfs4_deviceid *d_id, struct osd_dev *od,
	gfp_t gfp_flags)
{
	struct nfs4_deviceid_node *d;
	struct objio_dev_ent *de = kzalloc(sizeof(*de), gfp_flags);
	struct objio_dev_ent *n;

	if (!de) {
		dprintk("%s: -ENOMEM od=%p\n", __func__, od);
		return NULL;
	}

	dprintk("%s: Adding od=%p\n", __func__, od);
	nfs4_init_deviceid_node(&de->id_node,
				nfss->pnfs_curr_ld,
				nfss->nfs_client,
				d_id);
	de->od.od = od;

	d = nfs4_insert_deviceid_node(&de->id_node);
	n = container_of(d, struct objio_dev_ent, id_node);
	if (n != de) {
		dprintk("%s: Race with other n->od=%p\n", __func__, n->od.od);
		objio_free_deviceid_node(&de->id_node);
		de = n;
	}

	return de;
}

struct objio_segment {
	struct pnfs_layout_segment lseg;

	struct ore_layout layout;
	struct ore_components oc;
};

static inline struct objio_segment *
OBJIO_LSEG(struct pnfs_layout_segment *lseg)
{
	return container_of(lseg, struct objio_segment, lseg);
}

struct objio_state;
typedef int (*objio_done_fn)(struct objio_state *ios);

struct objio_state {
	/* Generic layer */
	struct objlayout_io_res oir;

	struct page **pages;
	unsigned pgbase;
	unsigned nr_pages;
	unsigned long count;
	loff_t offset;
	bool sync;

	struct ore_layout *layout;
	struct ore_components *oc;

	struct kref kref;
	objio_done_fn done;
	void *private;

	unsigned long length;
	unsigned