path: root/fs/ocfs2/localalloc.c

/* -*- mode: c; c-basic-offset: 8; -*-
 * vim: noexpandtab sw=8 ts=8 sts=0:
 *
 * localalloc.c
 *
 * Node local data allocation
 *
 * 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>
#include <linux/bitops.h>

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

#include "ocfs2.h"

#include "alloc.h"
#include "blockcheck.h"
#include "dlmglue.h"
#include "inode.h"
#include "journal.h"
#include "localalloc.h"
#include "suballoc.h"
#include "super.h"
#include "sysfile.h"

#include "buffer_head_io.h"

#define OCFS2_LOCAL_ALLOC(dinode)	(&((dinode)->id2.i_lab))

static u32 ocfs2_local_alloc_count_bits(struct ocfs2_dinode *alloc);

static int ocfs2_local_alloc_find_clear_bits(struct ocfs2_super *osb,
					     struct ocfs2_dinode *alloc,
					     u32 *numbits,
					     struct ocfs2_alloc_reservation *resv);

static void ocfs2_clear_local_alloc(struct ocfs2_dinode *alloc);

static int ocfs2_sync_local_to_main(struct ocfs2_super *osb,
				    handle_t *handle,
				    struct ocfs2_dinode *alloc,
				    struct inode *main_bm_inode,
				    struct buffer_head *main_bm_bh);

static int ocfs2_local_alloc_reserve_for_window(struct ocfs2_super *osb,
						struct ocfs2_alloc_context **ac,
						struct inode **bitmap_inode,
						struct buffer_head **bitmap_bh);

static int ocfs2_local_alloc_new_window(struct ocfs2_super *osb,
					handle_t *handle,
					struct ocfs2_alloc_context *ac);

static int ocfs2_local_alloc_slide_window(struct ocfs2_super *osb,
					  struct inode *local_alloc_inode);

static inline int ocfs2_la_state_enabled(struct ocfs2_super *osb)
{
	return (osb->local_alloc_state == OCFS2_LA_THROTTLED ||
		osb->local_alloc_state == OCFS2_LA_ENABLED);
}

void ocfs2_local_alloc_seen_free_bits(struct ocfs2_super *osb,
				      unsigned int num_clusters)
{
	spin_lock(&osb->osb_lock);
	if (osb->local_alloc_state == OCFS2_LA_DISABLED ||
	    osb->local_alloc_state == OCFS2_LA_THROTTLED)
		if (num_clusters >= osb->local_alloc_default_bits) {
			cancel_delayed_work(&osb->la_enable_wq);
			osb->local_alloc_state = OCFS2_LA_ENABLED;
		}
	spin_unlock(&osb->osb_lock);
}

void ocfs2_la_enable_worker(struct work_struct *work)
{
	struct ocfs2_super *osb =
		container_of(work, struct ocfs2_super,
			     la_enable_wq.work);
	spin_lock(&osb->osb_lock);
	osb->local_alloc_state = OCFS2_LA_ENABLED;
	spin_unlock(&osb->osb_lock);
}

/*
 * Tell us whether a given allocation should use the local alloc
 * file. Otherwise, it has to go to the main bitmap.
 *
 * This function does semi-dirty reads of local alloc size and state!
 * This is ok however, as the values are re-checked once under mutex.
 */
int ocfs2_alloc_should_use_local(struct ocfs2_super *osb, u64 bits)
{
	int ret = 0;
	int la_bits;

	spin_lock(&osb->osb_lock);
	la_bits = osb->local_alloc_bits;

	if (!ocfs2_la_state_enabled(osb))
		goto bail;

	/* la_bits should be at least twice the size (in clusters) of