/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
 * vim:expandtab:shiftwidth=8:tabstop=8:
 *
 *  Copyright (C) 2001, 2002, 2003, 2004 Cluster File Systems, Inc.
 *
 *  Author: <braam@clusterfs.com>
 *
 *   This file is part of Lustre, http://www.lustre.org.
 *
 *   Lustre is free software; you can redistribute it and/or
 *   modify it under the terms of version 2 of the GNU General Public
 *   License as published by the Free Software Foundation.
 *
 *   Lustre 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 for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with Lustre; if not, write to the Free Software
 *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 * lustre VFS/process permission interface
 */

#ifndef __LVFS_H__
#define __LVFS_H__

#include <libcfs/kp30.h>

#define LL_ID_NAMELEN (16 + 1 + 8 + 1)

#if defined __KERNEL__
#include <linux/dcache.h>
#include <linux/namei.h>
#include <linux/lustre_compat25.h>
#include <linux/lvfs_linux.h>
#endif

#ifdef LIBLUSTRE
#include <lvfs_user_fs.h>
#endif

struct mds_grp_hash_entry;

/* simple.c */
struct lvfs_ucred {
        struct lustre_sec_desc *luc_lsd;
        struct group_info      *luc_ginfo;
        __u32 luc_fsuid;
        __u32 luc_fsgid;
        __u32 luc_cap;
        __u32 luc_uid;
        __u32 luc_umask;
};

struct lvfs_callback_ops {
        struct dentry *(*l_id2dentry)(__u64 ino, __u32 gen, 
                                      __u64 gr, void *data);
};

#define OBD_RUN_CTXT_MAGIC      0xC0FFEEAA
#define OBD_CTXT_DEBUG          /* development-only debugging */
struct lvfs_run_ctxt {
        struct vfsmount	        *pwdmnt;
        struct dentry           *pwd;
        mm_segment_t             fs;
        struct lvfs_ucred        luc;
        struct lvfs_callback_ops cb_ops;
        int                      ngroups;
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,4)
        struct group_info       *group_info;
#else
        struct group_info        group_info;
#endif
#ifdef OBD_CTXT_DEBUG
        int                      pid;
        __u32                    magic;
#endif
};

struct lvfs_obd_ctxt {
        struct vfsmount *loc_mnt;
        atomic_t         loc_refcount;
        char            *loc_name;
        struct list_head loc_list; 
};

#ifdef OBD_CTXT_DEBUG
#define OBD_SET_CTXT_MAGIC(ctxt) (ctxt)->magic = OBD_RUN_CTXT_MAGIC
#else
#define OBD_SET_CTXT_MAGIC(ctxt) do {} while(0)
#endif

/* lvfs_common.c */
struct dentry *lvfs_id2dentry(struct lvfs_run_ctxt *, __u64, 
                              __u32, __u64 ,void *data);

void push_ctxt(struct lvfs_run_ctxt *save, struct lvfs_run_ctxt *new_ctx,
               struct lvfs_ucred *cred);
void pop_ctxt(struct lvfs_run_ctxt *saved, struct lvfs_run_ctxt *new_ctx,
              struct lvfs_ucred *cred);

#ifdef __KERNEL__
int lvfs_reint(struct super_block *sb, void *r_rec);
int lvfs_undo(struct super_block *sb, void *r_rec);
struct dentry *simple_mkdir(struct dentry *dir, char *name, int mode, int fix);
struct dentry *simple_mknod(struct dentry *dir, char *name, int mode, int fix);
int lustre_fread(struct file *file, void *buf, int len, loff_t *off);
int lustre_fwrite(struct file *file, const void *buf, int len, loff_t *off);
int lustre_fsync(struct file *file);
long l_readdir(struct file * file, struct list_head *dentry_list);
int lvfs_mount_fs(char *name, char *fstype, char *options, int flags, 
                  struct lvfs_obd_ctxt **lvfs_ctxt);
void lvfs_umount_fs(struct lvfs_obd_ctxt *lvfs_ctxt);
static inline void l_dput(struct dentry *de)
{
        if (!de || IS_ERR(de))
                return;
        //shrink_dcache_parent(de);
        LASSERT(atomic_read(&de->d_count) > 0);
        dput(de);
}

#ifdef S_PDIROPS
void *lock_dir(struct inode *dir, struct qstr *name);
void unlock_dir(struct inode *dir, void *lock);
#endif

/* We need to hold the inode semaphore over the dcache lookup itself, or we run
 * the risk of entering the filesystem lookup path concurrently on SMP systems,
 * and instantiating two inodes for the same entry.  We still protect against
 * concurrent addition/removal races with the DLM locking. */
static inline struct dentry *
ll_lookup_one_len(const char *name, struct dentry *dparent, int namelen)
{
        struct dentry *dchild;
#ifdef S_PDIROPS
        struct qstr qstr;
        void *lock;
        qstr.name = name;
        qstr.len = namelen;
        lock = lock_dir(dparent->d_inode, &qstr);
#else
        down(&dparent->d_inode->i_sem);
#endif

        dchild = lookup_one_len(name, dparent, namelen);

#ifdef S_PDIROPS
        unlock_dir(dparent->d_inode, lock);
#else
        up(&dparent->d_inode->i_sem);
#endif

        if (IS_ERR(dchild) || dchild->d_inode == NULL)
                return dchild;

        if (is_bad_inode(dchild->d_inode)) {
                CERROR("bad inode returned %lu/%u\n",
                       dchild->d_inode->i_ino, dchild->d_inode->i_generation);
                dput(dchild);
                dchild = ERR_PTR(-ENOENT);
        }

        return dchild;
}

static inline void ll_sleep(int t)
{
        set_current_state(TASK_INTERRUPTIBLE);
        schedule_timeout(t * HZ);
        set_current_state(TASK_RUNNING);
}
#endif

static inline int ll_id2str(char *str, __u64 id, __u32 generation)
{
        return sprintf(str, "%llx:%08x", (unsigned long long)id, 
                       generation);
}

#endif