/* -*- mode: c; c-basic-offset: 8; -*-
* vim: noexpandtab sw=8 ts=8 sts=0:
*
* slot_map.c
*
*
*
* 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/types.h>
#include <linux/slab.h>
#include <linux/highmem.h>
#define MLOG_MASK_PREFIX ML_SUPER
#include <cluster/masklog.h>
#include "ocfs2.h"
#include "dlmglue.h"
#include "extent_map.h"
#include "heartbeat.h"
#include "inode.h"
#include "slot_map.h"
#include "super.h"
#include "sysfile.h"
#include "buffer_head_io.h"
static s16 __ocfs2_node_num_to_slot(struct ocfs2_slot_info *si,
s16 global);
static void __ocfs2_fill_slot(struct ocfs2_slot_info *si,
s16 slot_num,
s16 node_num);
/* Use the slot information we've collected to create a map of mounted
* nodes. Should be holding an EX on super block. assumes slot info is
* up to date. Note that we call this *after* we find a slot, so our
* own node should be set in the map too... */
void ocfs2_populate_mounted_map(struct ocfs2_super *osb)
{
int i;
struct ocfs2_slot_info *si = osb->slot_info;
spin_lock(&si->si_lock);
for (i = 0; i < si->si_size; i++)
if (si->si_global_node_nums[i] != OCFS2_INVALID_SLOT)
ocfs2_node_map_set_bit(osb, &osb->mounted_map,
si->si_global_node_nums[i]);
spin_unlock(&si->si_lock);
}
/* post the slot information on disk into our slot_info struct. */
void ocfs2_update_slot_info(struct ocfs2_slot_info *si)
{
int i;
__le16 *disk_info;
/* we don't read the slot block here as ocfs2_super_lock
* should've made sure we have the most recent copy. */
spin_lock(&si->si_lock);
disk_info = (__le16 *) si->si_bh->b_data;
for (i = 0; i < si->si_size; i++)
si->si_global_node_nums[i] = le16_to_cpu(disk_info[i]);
spin_unlock(&si->si_lock);
}
/* post the our slot info stuff into it's destination bh and write it
* out. */
int ocfs2_update_disk_slots(struct ocfs2_super *osb,
struct ocfs2_slot_info *si)
{
int status, i;
__le16 *disk_info = (__le16 *) si->si_bh->b_data;
spin_lock(&si->si_lock);
for (i = 0; i < si->si_size; i++)
disk_info[i] = cpu_to_le16(si->si_global_node_nums[i]);
spin_unlock(&si->si_lock);
status = ocfs2_write_block(osb, si->si_bh, si->si_inode);
if (status < 0)
mlog_errno(status);
return status;
}
/* try to find global node in the slot info. Returns
* OCFS2_INVALID_SLOT if nothing is found. */
static s16 __ocfs2_node_num_to_slot(struct ocfs2_slot_info *si,
s16 global)
{
int i;
s16 ret = OCFS2_INVALID_SLOT;
for(i = 0; i < si->si_num_slots; i++) {
if (global == si->si_global_node_nums[i]) {
ret = (s16) i;
break;
}
}
return ret;
}
static s16 __ocfs2_find_empty_slot(struct ocfs2_slot_info *si)
{
int i;
s16 ret = OCFS2_INVALID_SLOT;
for(i = 0; i < si->si_num_slots; i++) {
if (OCFS2_INVALID_SLOT == si->si_global_node_nums[i]) {
ret = (s16) i;
break;
}
}
return ret;
}
s16 ocfs2_node_num_to_slot(struct ocfs2_slot_info *si,
s16 global)
{
s16 ret;
spin_lock(&si->si_lock);
ret = __ocfs2_node_num_to_slot(si, global);
spin_unlock(&si->si_lock);
return ret;
}
static void __ocfs2_fill_slot(struct ocfs2_slot_info *si,
s16 slot_num,
s16 node_num)
{
BUG_ON(slot_num == OCFS2_INVALID_SLOT);
BUG_ON(slot_num >= si->si_num_slots);
BUG_ON((node_num != O2NM_INVALID_NODE_NUM) &&
(node_num >= O2NM_MAX_NODES));
si->si_global_node_nums[slot_num] = node_num;
}
void ocfs2_clear_slot(struct ocfs2_slot_info *si,
s16 slot_num)
{
spin_lock(&si->si_lock);
__ocfs2_fill_slot(si, slot_num, OCFS2_INVALID_SLOT);
spin_unlock(&si->si_lock);
}
int ocfs2_init_slot_info(struct ocfs2_super *osb)
{
int status, i;
u64 blkno;
struct inode *inode = NULL;
struct buffer_head *bh = NULL;
struct ocfs2_slot_info *si;
si = kzalloc(sizeof(struct ocfs2_slot_info), GFP_KERNEL);
if (!si) {
status = -ENOMEM;
mlog_errno(status);
goto bail;
}
spin_lock_init(&si->si_lock);
si->si_num_slots = osb->max_slots;
si->si_size = OCFS2_MAX_SLOTS;
for(i = 0; i < si->si_num_slots; i++)
si->si_global_node_nums[i] = OCFS2_INVALID_SLOT;
inode = ocfs2_get_system_file_inode(osb, SLOT_MAP_SYSTEM_INODE,
OCFS2_INVALID_SLOT);
if (!inode) {
status = -EINVAL;
mlog_errno(status);
goto bail;
}
status = ocfs2_extent_map_get_blocks(inode, 0ULL, &blkno, NULL, NULL);
if (status < 0) {
mlog_errno(status);
goto bail;
}
status = ocfs2_read_block(osb, blkno, &bh, 0, inode);
if (status < 0) {
mlog_errno(status);
goto bail;
}
si->si_inode = inode;
si->si_bh = bh;
osb->slot_info = si;
bail:
if (status < 0 && si)
ocfs2_free_slot_info(si);
return status;
}
void ocfs2_free_slot_info(struct ocfs2_slot_info *si)
{
if (si->si_inode)
iput(si->si_inode);
if (si->si_bh)
brelse(si->si_bh);
kfree(si);
}
int ocfs2_find_slot(struct ocfs2_super *osb)
{
int status;
s16 slot;
struct ocfs2_slot_info *si;
mlog_entry_void();
si = osb->slot_info;
ocfs2_update_slot_info(si);
spin_lock(&si->si_lock);
/* search for ourselves first and take the slot if it already
* exists. Perhaps we need to mark this in a variable for our
* own journal recovery? Possibly not, though we certainly
* need to warn to the user */
slot = __ocfs2_node_num_to_slot(si, osb->node_num);
if (slot == OCFS2_INVALID_SLOT) {
/* if no slot yet, then just take 1st available
* one. */
slot = __ocfs2_find_empty_slot(si);
if (slot == OCFS2_INVALID_SLOT) {
spin_unlock(&si->si_lock);
mlog(ML_ERROR, "no free slots available!\n");
status = -EINVAL;
goto bail;
}
} else
mlog(ML_NOTICE, "slot %d is already allocated to this node!\n",
slot);
__ocfs2_fill_slot(si, slot, osb->node_num);
osb->slot_num = slot;
spin_unlock(&si->si_lock);
mlog(0, "taking node slot %d\n", osb->slot_num);
status = ocfs2_update_disk_slots(osb, si);
if (status < 0)
mlog_errno(status);
bail:
mlog_exit(status);
return status;
}
void ocfs2_put_slot(struct ocfs2_super *osb)
{
int status;
struct ocfs2_slot_info *si = osb->slot_info;
if (!si)
return;
ocfs2_update_slot_info(si);
spin_lock(&si->si_lock);
__ocfs2_fill_slot(si, osb->slot_num, OCFS2_INVALID_SLOT);
osb->slot_num = OCFS2_INVALID_SLOT;
spin_unlock(&si->si_lock);
status = ocfs2_update_disk_slots(osb, si);
if (status < 0) {
mlog_errno(status);
goto bail;
}
bail:
osb->slot_info = NULL;
ocfs2_free_slot_info(si);
}
