/*
 * 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.gnu.org/licenses/gpl-2.0.html
 *
 * GPL HEADER END
 */
/*
 * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
 * Use is subject to license terms.
 *
 * Copyright (c) 2013, 2015, Intel Corporation.
 */
/*
 * This file is part of Lustre, http://www.lustre.org/
 * Lustre is a trademark of Sun Microsystems, Inc.
 *
 * Internal definitions for VVP layer.
 *
 *   Author: Nikita Danilov <nikita.danilov@sun.com>
 */

#ifndef VVP_INTERNAL_H
#define VVP_INTERNAL_H

#include "../include/lustre/lustre_idl.h"
#include "../include/cl_object.h"

enum obd_notify_event;
struct inode;
struct lov_stripe_md;
struct lustre_md;
struct obd_capa;
struct obd_device;
struct obd_export;
struct page;

/**
 * IO state private to IO state private to VVP layer.
 */
struct vvp_io {
        /** super class */
        struct cl_io_slice     vui_cl;
        struct cl_io_lock_link vui_link;
        /**
         * I/O vector information to or from which read/write is going.
         */
        struct iov_iter *vui_iter;
        /**
         * Total size for the left IO.
         */
        size_t vui_tot_count;

        union {
                struct vvp_fault_io {
                        /**
                         * Inode modification time that is checked across DLM
                         * lock request.
                         */
                        time64_t            ft_mtime;
                        struct vm_area_struct *ft_vma;
                        /**
                         *  locked page returned from vvp_io
                         */
                        struct page         *ft_vmpage;
                        /**
                         * kernel fault info
                         */
                        struct vm_fault *ft_vmf;
                        /**
                         * fault API used bitflags for return code.
                         */
                        unsigned int    ft_flags;
                        /**
                         * check that flags are from filemap_fault
                         */
                        bool            ft_flags_valid;
                } fault;
                struct {
                        struct cl_page_list vui_queue;
                        unsigned long vui_written;
                        int vui_from;
                        int vui_to;
                } write;
        } u;

        /**
         * Layout version when this IO is initialized
         */
        __u32                   vui_layout_gen;
        /**
         * File descriptor against which IO is done.
         */
        struct ll_file_data     *vui_fd;
        struct kiocb            *vui_iocb;

        /* Readahead state. */
        pgoff_t vui_ra_start;
        pgoff_t vui_ra_count;
        /* Set when vui_ra_{start,count} have been initialized. */
        bool            vui_ra_valid;
};

extern struct lu_device_type vvp_device_type;

extern struct lu_context_key vvp_session_key;
extern struct lu_context_key vvp_thread_key;

extern struct kmem_cache *vvp_lock_kmem;
extern struct kmem_cache *vvp_object_kmem;
extern struct kmem_cache *vvp_req_kmem;

struct vvp_thread_info {
        struct cl_lock          vti_lock;
        struct cl_lock_descr    vti_descr;
        struct cl_io            vti_io;
        struct cl_attr          vti_attr;
};

static inline struct vvp_thread_info *vvp_env_info(const struct lu_env *env)
{
        struct vvp_thread_info      *vti;

        vti = lu_context_key_get(&env->le_ctx, &vvp_thread_key);
        LASSERT(vti);

        return vti;
}

static inline struct cl_lock *vvp_env_lock(const struct lu_env *env)
{
        struct cl_lock *lock = &vvp_env_info(env)->vti_lock;

        memset(lock, 0, sizeof(*lock));
        return lock;
}

static inline struct cl_attr *vvp_env_thread_attr(const struct lu_env *env)
{
        struct cl_attr *attr = &vvp_env_info(env)->vti_attr;

        memset(attr, 0, sizeof(*attr));

        return attr;
}

static inline struct cl_io *vvp_env_thread_io(const struct lu_env *env)
{
        struct cl_io *io = &vvp_env_info(env)->vti_io;

        memset(io, 0, sizeof(*io));

        return io;
}

struct vvp_session {
        struct vvp_io cs_ios;
};

static inline struct vvp_session *vvp_env_session(const struct lu_env *env)
{
        struct vvp_session *ses;

        ses = lu_context_key_get(env->le_ses, &vvp_session_key);
        LASSERT(ses);

        return ses;
}

static inline struct vvp_io *vvp_env_io(const struct lu_env *env)
{
        return &vvp_env_session(env)->cs_ios;
}

/**
 * ccc-private object state.
 */
struct vvp_object {
        struct cl_object_header vob_header;
        struct cl_object        vob_cl;
        struct inode           *vob_inode;

        /**
         * A list of dirty pages pending IO in the cache. Used by
         * SOM. Protected by ll_inode_info::lli_lock.
         *
         * \see vvp_page::vpg_pending_linkage
         */
        struct list_head        vob_pending_list;

        /**
         * Number of transient pages.  This is no longer protected by i_sem,
         * and needs to be atomic.  This is not actually used for anything,
         * and can probably be removed.
         */
        atomic_t                vob_transient_pages;

        /**
         * Number of outstanding mmaps on this file.
         *
         * \see ll_vm_open(), ll_vm_close().
         */
        atomic_t                vob_mmap_cnt;

        /**
         * various flags
         * vob_discard_page_warned
         *     if pages belonging to this object are discarded when a client
         * is evicted, some debug info will be printed, this flag will be set
         * during processing the first discarded page, then avoid flooding
         * debug message for lots of discarded pages.
         *
         * \see ll_dirty_page_discard_warn.
         */
        unsigned int            vob_discard_page_warned:1;
};

/**
 * VVP-private page state.
 */
struct vvp_page {
        struct cl_page_slice vpg_cl;
        unsigned int    vpg_defer_uptodate:1,
                        vpg_ra_used:1,
                        vpg_write_queued:1;
        /**
         * Non-empty iff this page is already counted in
         * vvp_object::vob_pending_list. This list is only used as a flag,
         * that is, never iterated through, only checked for list_empty(), but
         * having a list is useful for debugging.
         */
        struct list_head           vpg_pending_linkage;
        /** VM page */
        struct page       *vpg_page;
};

static inline struct vvp_page *cl2vvp_page(const struct cl_page_slice *slice)
{
        return container_of(slice, struct vvp_page, vpg_cl);
}

static inline pgoff_t vvp_index(struct vvp_page *vvp)
{
        return vvp->vpg_cl.cpl_index;
}

struct vvp_device {
        struct cl_device    vdv_cl;
        struct super_block *vdv_sb;
        struct cl_device   *vdv_next;
};

struct vvp_lock {
        struct cl_lock_slice vlk_cl;
};

struct vvp_req {
        struct cl_req_slice  vrq_cl;
};

void *ccc_key_init(const struct lu_context *ctx,
                   struct lu_context_key *key);
void ccc_key_fini(const struct lu_context *ctx,
                  struct lu_context_key *key, void *data);

void ccc_umount(const struct lu_env *env, struct cl_device *dev);

static inline struct lu_device *vvp2lu_dev(struct vvp_device *vdv)
{
        return &vdv->vdv_cl.cd_lu_dev;
}

static inline struct vvp_device *lu2vvp_dev(const struct lu_device *d)
{
        return container_of0(d, struct vvp_device, vdv_cl.cd_lu_dev);
}

static inline struct vvp_device *cl2vvp_dev(const struct cl_device *d)
{
        return container_of0(d, struct vvp_device, vdv_cl);
}

static inline struct vvp_object *cl2vvp(const struct cl_object *obj)
{
        return container_of0(obj, struct vvp_object, vob_cl);
}

static inline struct vvp_object *lu2vvp(const struct lu_object *obj)
{
        return container_of0(obj, struct vvp_object, vob_cl.co_lu);
}

static inline struct inode *vvp_object_inode(const struct cl_object *obj)
{
        return cl2vvp(obj)->vob_inode;
}

int vvp_object_invariant(const struct cl_object *obj);
struct vvp_object *cl_inode2vvp(struct inode *inode);

static inline struct page *cl2vm_page(const struct cl_page_slice *slice)
{
        return cl2vvp_page(slice)->vpg_page;
}

static inline struct vvp_lock *cl2vvp_lock(const struct cl_lock_slice *slice)
{
        return container_of(slice, struct vvp_lock, vlk_cl);
}

# define CLOBINVRNT(env, clob, expr)                                    \
        ((void)sizeof(env), (void)sizeof(clob), (void)sizeof(!!(expr)))

/**
 * New interfaces to get and put lov_stripe_md from lov layer. This violates
 * layering because lov_stripe_md is supposed to be a private data in lov.
 *
 * NB: If you find you have to use these interfaces for your new code, please
 * think about it again. These interfaces may be removed in the future for
 * better layering.
 */
struct lov_stripe_md *lov_lsm_get(struct cl_object *clobj);
void lov_lsm_put(struct cl_object *clobj, struct lov_stripe_md *lsm);
int lov_read_and_clear_async_rc(struct cl_object *clob);

struct lov_stripe_md *ccc_inode_lsm_get(struct inode *inode);
void ccc_inode_lsm_put(struct inode *inode, struct lov_stripe_md *lsm);

int vvp_io_init(const struct lu_env *env, struct cl_object *obj,
                struct cl_io *io);
int vvp_io_write_commit(const struct lu_env *env, struct cl_io *io);
int vvp_lock_init(const struct lu_env *env, struct cl_object *obj,
                  struct cl_lock *lock, const struct cl_io *io);
int vvp_page_init(const struct lu_env *env, struct cl_object *obj,
                  struct cl_page *page, pgoff_t index);
int vvp_req_init(const struct lu_env *env, struct cl_device *dev,
                 struct cl_req *req);
struct lu_object *vvp_object_alloc(const struct lu_env *env,
                                   const struct lu_object_header *hdr,
                                   struct lu_device *dev);

int vvp_global_init(void);
void vvp_global_fini(void);

extern const struct file_operations vvp_dump_pgcache_file_ops;

#endif /* VVP_INTERNAL_H */