/** @file
 * vboxsf - VirtualBox Guest Additions for Linux.
 */

/*
 * Copyright (C) 2006-2016 Oracle Corporation
 *
 * This file is part of VirtualBox Open Source Edition (OSE), as
 * available from http://www.virtualbox.org. This file is free software;
 * you can redistribute it and/or modify it under the terms of the GNU
 * General Public License (GPL) as published by the Free Software
 * Foundation, in version 2 as it comes in the "COPYING" file of the
 * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
 * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
 */

#ifndef VFSMOD_H
#define VFSMOD_H

#define LOG_GROUP LOG_GROUP_SHARED_FOLDERS
#include "the-linux-kernel.h"
#include <VBox/log.h>

#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 0)
# include <linux/backing-dev.h>
#endif

#include <VBox/VBoxGuestLibSharedFolders.h>
#include "vbsfmount.h"

#define DIR_BUFFER_SIZE (16*_1K)

/* per-shared folder information */
struct sf_glob_info
{
    VBGLSFMAP map;
    struct nls_table *nls;
    int ttl;
    int uid;
    int gid;
    int dmode;
    int fmode;
    int dmask;
    int fmask;
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 0)
    struct backing_dev_info bdi;
#endif
};

/* per-inode information */
struct sf_inode_info
{
    /* which file */
    SHFLSTRING *path;
    /* some information was changed, update data on next revalidate */
    int force_restat;
    /* directory content changed, update the whole directory on next sf_getdent */
    int force_reread;
    /* file structure, only valid between open() and release() */
    struct file *file;
    /* handle valid if a file was created with sf_create_aux until it will
     * be opened with sf_reg_open() */
    SHFLHANDLE handle;
};

struct sf_dir_info
{
    struct list_head info_list;
};

struct sf_dir_buf
{
    size_t cEntries;
    size_t cbFree;
    size_t cbUsed;
    void   *buf;
    struct list_head head;
};

struct sf_reg_info
{
    SHFLHANDLE handle;
};

/* globals */
extern VBGLSFCLIENT client_handle;

/* forward declarations */
extern struct inode_operations         sf_dir_iops;
extern struct inode_operations         sf_lnk_iops;
extern struct inode_operations         sf_reg_iops;
extern struct file_operations          sf_dir_fops;
extern struct file_operations          sf_reg_fops;
extern struct dentry_operations        sf_dentry_ops;
extern struct address_space_operations sf_reg_aops;

extern void sf_init_inode(struct sf_glob_info *sf_g, struct inode *inode,
                          PSHFLFSOBJINFO info);
extern int  sf_stat(const char *caller, struct sf_glob_info *sf_g,
                    SHFLSTRING *path, PSHFLFSOBJINFO result, int ok_to_fail);
extern int  sf_inode_revalidate(struct dentry *dentry);
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 0)
# if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 11, 0)
extern int  sf_getattr(const struct path *path, struct kstat *kstat,
                       u32 request_mask, unsigned int query_flags);
# else
extern int  sf_getattr(struct vfsmount *mnt, struct dentry *dentry,
                       struct kstat *kstat);
#endif
extern int  sf_setattr(struct dentry *dentry, struct iattr *iattr);
#endif
extern int  sf_path_from_dentry(const char *caller, struct sf_glob_info *sf_g,
                                struct sf_inode_info *sf_i, struct dentry *dentry,
                                SHFLSTRING **result);
extern int  sf_nlscpy(struct sf_glob_info *sf_g,
                      char *name, size_t name_bound_len,
                      const unsigned char *utf8_name, size_t utf8_len);
extern void sf_dir_info_free(struct sf_dir_info *p);
extern void sf_dir_info_empty(struct sf_dir_info *p);
extern struct sf_dir_info *sf_dir_info_alloc(void);
extern int  sf_dir_read_all(struct sf_glob_info *sf_g, struct sf_inode_info *sf_i,
                            struct sf_dir_info *sf_d, SHFLHANDLE handle);
extern int  sf_init_backing_dev(struct sf_glob_info *sf_g);
extern void sf_done_backing_dev(struct sf_glob_info *sf_g);

#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 0)
# define STRUCT_STATFS  struct statfs
#else
# define STRUCT_STATFS  struct kstatfs
#endif
int sf_get_volume_info(struct super_block *sb,STRUCT_STATFS *stat);

#ifdef __cplusplus
# define CMC_API __attribute__ ((cdecl, regparm (0)))
#else
# define CMC_API __attribute__ ((regparm (0)))
#endif

#define TRACE() LogFunc(("tracepoint\n"))

/* Following casts are here to prevent assignment of void * to
   pointers of arbitrary type */
#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 0)
# define GET_GLOB_INFO(sb)       ((struct sf_glob_info *) (sb)->u.generic_sbp)
# define SET_GLOB_INFO(sb, sf_g) (sb)->u.generic_sbp = sf_g
#else
# define GET_GLOB_INFO(sb)       ((struct sf_glob_info *) (sb)->s_fs_info)
# define SET_GLOB_INFO(sb, sf_g) (sb)->s_fs_info = sf_g
#endif

#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 19) || defined(KERNEL_FC6)
/* FC6 kernel 2.6.18, vanilla kernel 2.6.19+ */
# define GET_INODE_INFO(i)       ((struct sf_inode_info *) (i)->i_private)
# define SET_INODE_INFO(i, sf_i) (i)->i_private = sf_i
#else
/* vanilla kernel up to 2.6.18 */
# define GET_INODE_INFO(i)       ((struct sf_inode_info *) (i)->u.generic_ip)
# define SET_INODE_INFO(i, sf_i) (i)->u.generic_ip = sf_i
#endif

#if LINUX_VERSION_CODE >= KERNEL_VERSION(3, 19, 0)
# define GET_F_DENTRY(f)        (f->f_path.dentry)
#else
# define GET_F_DENTRY(f)        (f->f_dentry)
#endif

#endif