/*
 * GPL HEADER START
 *
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 only,
 * as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License version 2 for more details (a copy is included
 * in the LICENSE file that accompanied this code).
 *
 * You should have received a copy of the GNU General Public License
 * version 2 along with this program; If not, see
 * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
 *
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 *
 * GPL HEADER END
 */
/*
 * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
 * Use is subject to license terms.
 *
 * Copyright (c) 2012, 2015, Intel Corporation.
 */
/*
 * This file is part of Lustre, http://www.lustre.org/
 * Lustre is a trademark of Sun Microsystems, Inc.
 *
 * cl_object implementation for VVP layer.
 *
 *   Author: Nikita Danilov <nikita.danilov@sun.com>
 */

#define DEBUG_SUBSYSTEM S_LLITE

#include "../../include/linux/libcfs/libcfs.h"

#include "../include/obd.h"
#include "../include/lustre_lite.h"

#include "llite_internal.h"
#include "vvp_internal.h"

/*****************************************************************************
 *
 * Object operations.
 *
 */

int vvp_object_invariant(const struct cl_object *obj)
{
	struct inode *inode  = vvp_object_inode(obj);
	struct ll_inode_info *lli = ll_i2info(inode);

	return (S_ISREG(inode->i_mode) || inode->i_mode == 0) &&
		lli->lli_clob == obj;
}

static int vvp_object_print(const struct lu_env *env, void *cookie,
			    lu_printer_t p, const struct lu_object *o)
{
	struct vvp_object    *obj   = lu2vvp(o);
	struct inode	 *inode = obj->vob_inode;
	struct ll_inode_info *lli;

	(*p)(env, cookie, "(%s %d %d) inode: %p ",
	     list_empty(&obj->vob_pending_list) ? "-" : "+",
	     obj->vob_transient_pages, atomic_read(&obj->vob_mmap_cnt),
	     inode);
	if (inode) {
		lli = ll_i2info(inode);
		(*p)(env, cookie, "%lu/%u %o %u %d %p "DFID,
		     inode->i_ino, inode->i_generation, inode->i_mode,
		     inode->i_nlink, atomic_read(&inode->i_count),
		     lli->lli_clob, PFID(&lli->lli_fid));
	}
	return 0;
}

static int vvp_attr_get(const struct lu_env *env, struct cl_object *obj,
			struct cl_attr *attr)
{
	struct inode *inode = vvp_object_inode(obj);

	/*
	 * lov overwrites most of these fields in
	 * lov_attr_get()->...lov_merge_lvb_kms(), except when inode
	 * attributes are newer.
	 */

	attr->cat_size = i_size_read(inode);
	attr->cat_mtime = inode->i_mtime.tv_sec;
	attr->cat_atime = inode->i_atime.tv_sec;
	attr->cat_ctime = inode->i_ctime.tv_sec;
	attr->cat_blocks = inode->i_blocks;
	attr->cat_uid = from_kuid(&init_user_ns, inode->i_uid);
	attr->cat_gid = from_kgid(&init_user_ns, inode->i_gid);
	/* KMS is not known by this layer */
	return 0; /* layers below have to fill in the rest */
}

static int vvp_attr_set(const struct lu_env *env, struct cl_object *obj,
			const struct cl_attr *attr, unsigned valid)
{
	struct inode *inode = vvp_object_inode(obj);

	if (valid & CAT_UID)
		inode->i_uid = make_kuid(&init_user_ns, attr->cat_uid);
	if (valid & CAT_GID)
		inode->i_gid = make_kgid(&init_user_ns, attr->cat_gid);
	if (valid & CAT_ATIME)
		inode->i_atime.tv_sec = attr->cat_atime;
	if (valid & CAT_MTIME)
		inode->i_mtime.tv_sec = attr->cat_mtime;
	if (valid & CAT_CTIME)
		inode->i_ctime.tv_sec = attr->cat_ctime;
	if (0 && valid & CAT_SIZE)
		i_size_write(inode, attr->cat_size);
	/* not currently necessary */
	if (0 && valid & (CAT_UID|CAT_GID|CAT_SIZE))
		mark_inode_dirty(inode);
	return 0;
}

static int vvp_conf_set(const struct lu_env *env, struct cl_object *obj,
			const struct cl_object_conf *conf)
{
	struct ll_inode_info *lli = ll_i2info(conf->coc_inode);

	if (conf->coc_opc == OBJECT_CONF_INVALIDATE) {
		CDEBUG(D_VFSTRACE, DFID ": losing layout lock\n",
		       PFID(&lli->lli_fid));

		ll_layout_version_set(lli, LL_LAYOUT_GEN_NONE);

		/* Clean up page mmap for this inode.
		 * The reason for us to do this is that if the page has
		 * already been installed into memory space, the process
		 * can access it without interacting with lustre, so this
		 * page may be stale due to layout change, and the process
		 * will never be notified.
		 * This operation is expensive but mmap processes have to pay
		 * a price themselves.
		 */
		unmap_mapping_range(conf->coc_inode->i_mapping,
				    0, OBD_OBJECT_EOF, 0);

		return 0;
	}

	if (conf->coc_opc != OBJECT_CONF_SET)
		return 0;

	if (conf->u.coc_md && conf->u.coc_md->lsm) {
		CDEBUG(D_VFSTRACE, DFID ": layout version change: %u -> %u\n",
		       PFID(&lli->lli_fid), lli->lli_layout_gen,
		       conf->u.coc_md->lsm->lsm_layout_gen);

		lli->lli_has_smd = lsm_has_objects(conf->u.coc_md->lsm);
		ll_layout_version_set(lli, conf->u.coc_md->lsm->lsm_layout_gen);
	} else {
		CDEBUG(D_VFSTRACE, DFID ": layout nuked: %u.\n",
		       PFID(&lli->lli_fid), lli->lli_layout_gen);

		lli->lli_has_smd = false;
		ll_layout_version_set(lli, LL_LAYOUT_GEN_EMPTY);
	}
	return 0;
}

static int vvp_prune(const struct lu_env *env, struct cl_object *obj)
{
	struct inode *inode = vvp_object_inode(obj);
	int rc;

	rc = cl_sync_file_range(inode, 0, OBD_OBJECT_EOF, CL_FSYNC_LOCAL, 1);
	if (rc < 0) {
		CDEBUG(D_VFSTRACE, DFID ": writeback failed: %d\n",
		       PFID(lu_object_fid(&obj->co_lu)), rc);
		return rc;
	}

	truncate_inode_pages(inode->i_mapping, 0);
	return 0;
}

static int vvp_object_glimpse(const struct lu_env *env,
			      const struct cl_object *obj, struct ost_lvb *lvb)
{
	struct inode *inode = vvp_object_inode(obj);

	lvb->lvb_mtime = LTIME_S(inode->i_mtime);
	lvb->lvb_atime = LTIME_S(inode->i_atime);
	lvb->lvb_ctime = LTIME_S(inode->i_ctime);
	/*
	 * LU-417: Add dirty pages block count lest i_blocks reports 0, some
	 * "cp" or "tar" on remote node may think it's a completely sparse file
	 * and skip it.
	 */
	if (lvb->lvb_size > 0 && lvb->lvb_blocks == 0)
		lvb->lvb_blocks = dirty_cnt(inode);
	return 0;
}

static const struct cl_object_operations vvp_ops = {
	.coo_page_init = vvp_page_init,
	.coo_lock_init = vvp_lock_init,
	.coo_io_init   = vvp_io_init,
	.coo_attr_get  = vvp_attr_get,
	.coo_attr_set  = vvp_attr_set,
	.coo_conf_set  = vvp_conf_set,
	.coo_prune     = vvp_prune,
	.coo_glimpse   = vvp_object_glimpse
};

static int vvp_object_init0(const struct lu_env *env,
			    struct vvp_object *vob,
			    const struct cl_object_conf *conf)
{
	vob->vob_inode = conf->coc_inode;
	vob->vob_transient_pages = 0;
	cl_object_page_init(&vob->vob_cl, sizeof(struct vvp_page));
	return 0;
}

static int vvp_object_init(const struct lu_env *env, struct lu_object *obj,
			   const struct lu_object_conf *conf)
{
	struct vvp_device *dev = lu2vvp_dev(obj->lo_dev);
	struct vvp_object *vob = lu2vvp(obj);
	struct lu_object  *below;
	struct lu_device  *under;
	int result;

	under = &dev->vdv_next->cd_lu_dev;
	below = under->ld_ops->ldo_object_alloc(env, obj->lo_header, under);
	if (below) {
		const struct cl_object_conf *cconf;

		cconf = lu2cl_conf(conf);
		INIT_LIST_HEAD(&vob->vob_pending_list);
		lu_object_add(obj, below);
		result = vvp_object_init0(env, vob, cconf);
	} else {
		result = -ENOMEM;
	}

	return result;
}

static void vvp_object_free(const struct lu_env *env, struct lu_object *obj)
{
	struct vvp_object *vob = lu2vvp(obj);

	lu_object_fini(obj);
	lu_object_header_fini(obj->lo_header);
	kmem_cache_free(vvp_object_kmem, vob);
}

static const struct lu_object_operations vvp_lu_obj_ops = {
	.loo_object_init	= vvp_object_init,
	.loo_object_free	= vvp_object_free,
	.loo_object_print	= vvp_object_print,
};

struct vvp_object *cl_inode2vvp(struct inode *inode)
{
	struct ll_inode_info *lli = ll_i2info(inode);
	struct cl_object     *obj = lli->lli_clob;
	struct lu_object     *lu;

	lu = lu_object_locate(obj->co_lu.lo_header, &vvp_device_type);
	LASSERT(lu);
	return lu2vvp(lu);
}

struct lu_object *vvp_object_alloc(const struct lu_env *env,
				   const struct lu_object_header *unused,
				   struct lu_device *dev)
{
	struct vvp_object *vob;
	struct lu_object  *obj;

	vob = kmem_cache_zalloc(vvp_object_kmem, GFP_NOFS);
	if (vob) {
		struct cl_object_header *hdr;

		obj = &vob->vob_cl.co_lu;
		hdr = &vob->vob_header;
		cl_object_header_init(hdr);
		hdr->coh_page_bufsize = cfs_size_round(sizeof(struct cl_page));

		lu_object_init(obj, &hdr->coh_lu, dev);
		lu_object_add_top(&hdr->coh_lu, obj);

		vob->vob_cl.co_ops = &vvp_ops;
		obj->lo_ops = &vvp_lu_obj_ops;
	} else {
		obj = NULL;
	}
	return obj;
}