root/fs/ocfs2/sysfile.c

DEFINITIONS

1. is_global_system_inode
2. is_in_system_inode_array
3. ocfs2_get_system_file_inode
4. _ocfs2_get_system_file_inode

/* -*- mode: c; c-basic-offset: 8; -*-
 * vim: noexpandtab sw=8 ts=8 sts=0:
 *
 * sysfile.c
 *
 * Initialize, read, write, etc. system files.
 *
 * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * 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 for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this program; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 021110-1307, USA.
 */

#include <linux/fs.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/highmem.h>

#define MLOG_MASK_PREFIX ML_INODE
#include <cluster/masklog.h>

#include "ocfs2.h"

#include "alloc.h"
#include "dir.h"
#include "inode.h"
#include "journal.h"
#include "sysfile.h"

#include "buffer_head_io.h"

static struct inode * _ocfs2_get_system_file_inode(struct ocfs2_super *osb,
                                                   int type,
                                                   u32 slot);

static inline int is_global_system_inode(int type);
static inline int is_in_system_inode_array(struct ocfs2_super *osb,
                                           int type,
                                           u32 slot);

static inline int is_global_system_inode(int type)
{
        return type >= OCFS2_FIRST_ONLINE_SYSTEM_INODE &&
                type <= OCFS2_LAST_GLOBAL_SYSTEM_INODE;
}

static inline int is_in_system_inode_array(struct ocfs2_super *osb,
                                           int type,
                                           u32 slot)
{
        return slot == osb->slot_num || is_global_system_inode(type);
}

struct inode *ocfs2_get_system_file_inode(struct ocfs2_super *osb,
                                          int type,
                                          u32 slot)
{
        struct inode *inode = NULL;
        struct inode **arr = NULL;

        /* avoid the lookup if cached in local system file array */
        if (is_in_system_inode_array(osb, type, slot))
                arr = &(osb->system_inodes[type]);

        if (arr && ((inode = *arr) != NULL)) {
                /* get a ref in addition to the array ref */
                inode = igrab(inode);
                BUG_ON(!inode);

                return inode;
        }

        /* this gets one ref thru iget */
        inode = _ocfs2_get_system_file_inode(osb, type, slot);

        /* add one more if putting into array for first time */
        if (arr && inode) {
                *arr = igrab(inode);
                BUG_ON(!*arr);
        }
        return inode;
}

static struct inode * _ocfs2_get_system_file_inode(struct ocfs2_super *osb,
                                                   int type,
                                                   u32 slot)
{
        char namebuf[40];
        struct inode *inode = NULL;
        u64 blkno;
        int status = 0;

        ocfs2_sprintf_system_inode_name(namebuf,
                                        sizeof(namebuf),
                                        type, slot);

        status = ocfs2_lookup_ino_from_name(osb->sys_root_inode, namebuf,
                                            strlen(namebuf), &blkno);
        if (status < 0) {
                goto bail;
        }

        inode = ocfs2_iget(osb, blkno, OCFS2_FI_FLAG_SYSFILE, type);
        if (IS_ERR(inode)) {
                mlog_errno(PTR_ERR(inode));
                inode = NULL;
                goto bail;
        }
bail:

        return inode;
}