path: root/fs/gfs2/lops.c

/*
 * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
 * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
 *
 * This copyrighted material is made available to anyone wishing to use,
 * modify, copy, or redistribute it subject to the terms and conditions
 * of the GNU General Public License version 2.
 */

#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/completion.h>
#include <linux/buffer_head.h>
#include <linux/gfs2_ondisk.h>
#include <linux/lm_interface.h>

#include "gfs2.h"
#include "incore.h"
#include "inode.h"
#include "glock.h"
#include "log.h"
#include "lops.h"
#include "meta_io.h"
#include "recovery.h"
#include "rgrp.h"
#include "trans.h"
#include "util.h"

/**
 * gfs2_pin - Pin a buffer in memory
 * @sdp: The superblock
 * @bh: The buffer to be pinned
 *
 * The log lock must be held when calling this function
 */
static void gfs2_pin(struct gfs2_sbd *sdp, struct buffer_head *bh)
{
	struct gfs2_bufdata *bd;

	gfs2_assert_withdraw(sdp, test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags));

	clear_buffer_dirty(bh);
	if (test_set_buffer_pinned(bh))
		gfs2_assert_withdraw(sdp, 0);
	if (!buffer_uptodate(bh))
		gfs2_io_error_bh(sdp, bh);
	bd = bh->b_private;
	/* If this buffer is in the AIL and it has already been written
	 * to in-place disk block, remove it from the AIL.
	 */
	if (bd->bd_ail)
		list_move(&bd->bd_ail_st_list, &bd->bd_ail->ai_ail2_list);
	get_bh(bh);
}

/**
 * gfs2_unpin - Unpin a buffer
 * @sdp: the filesystem the buffer belongs to
 * @bh: The buffer to unpin
 * @ai:
 *
 */

static void gfs2_unpin(struct gfs2_sbd *sdp, struct buffer_head *bh,
		       struct gfs2_ail *ai)
{
	struct gfs2_bufdata *bd = bh->b_private;

	gfs2_assert_withdraw(sdp, buffer_uptodate(bh));

	if (!buffer_pinned(bh))
		gfs2_assert_withdraw(sdp, 0);

	lock_buffer(bh);
	mark_buffer_dirty(bh);
	clear_buffer_pinned(bh);

	gfs2_log_lock(sdp);
	if (bd->bd_ail) {
		list_del(&bd->bd_ail_st_list);
		brelse(bh);
	} else {
		struct gfs2_glock *gl = bd->bd_gl;
		list_add(&bd->bd_ail_gl_list, &gl->gl_ail_list);
		atomic_inc(&gl->gl_ail_count);
	}
	bd->bd_ail = ai;
	list_add(&bd->bd_ail_st_list, &ai->ai_ail1_list);
	gfs2_log_unlock(sdp);
	unlock_buffer(bh);
}

static void __glock_lo_add(struct gfs2_sbd *sdp, struct gfs2_log_element *le)
{
	struct gfs2_glock *gl;
	struct gfs2_trans *tr = current->journal_info;

	tr->tr_touched = 1;

	gl = container_of(le, struct gfs2_glock, gl_le);
	if (gfs2_assert_withdraw(sdp, gfs2_glock_is_held_excl(gl)))
		return;

	if (!list_empty(&le->le_list))
		return;

	gfs2_glock_hold(gl);
	set_bit(GLF_DIRTY, &gl->gl_flags);
	sdp->sd_log_num_gl++;
	list_add(&le->le_list, &sdp->sd_log_le_gl);
}

static void glock_lo_add(struct gfs2_sbd *sdp, struct gfs2_log_element *le)
{
	gfs2_log_lock(sdp);
	__glock_lo_add(sdp, le);
	gfs2_log_unlock(sdp);
}

static void glock_lo_after_commit(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
{
	struct list_head *head = &sdp->sd_log_le_gl;
	struct gfs2_glock *gl;

	while (!list_empty(head)) {
		gl = list_entry(head->next, struct gfs2_glock, gl_le.le_list);
		list_del_init(&gl->gl_le.le_list);
		sdp->sd_log_num_gl--;

		gfs2_assert_withdraw(sdp, gfs2_glock_is_held_excl(gl));
		gfs2_glock_put(gl);
	}
	gfs2_assert_warn(sdp, !sdp->sd_log_num_gl);
}

static void buf_lo_add(struct gfs2_sbd *sdp, struct gfs2_log_element *le)
{
	struct gfs2_bufdata *bd = container_of(le, struct gfs2_bufdata, bd_le);
	struct gfs2_trans *tr;

	lock_buffer(bd->bd_bh);
	gfs2_log_lock(sdp);
	if (!list_empty(&bd->bd_list_tr))
		goto out;
	tr = current->journal_info;
	tr->tr_touched = 1;
	tr->tr_num_buf++;
	list_add(&bd->bd_list_tr, &tr->tr_list_buf);
	if (!list_empty(&le->le_list))
		goto out;
	__glock_lo_add(sdp, &bd->bd_gl->gl_le);
	gfs2_meta_check(sdp, bd->bd_bh);
	gfs2_pin(sdp, bd->bd_bh);
	sdp->sd_log_num_buf++;
	list_add(&le->le_list, &sdp->sd_log_le_buf);
	tr->tr_num_buf_new++;
out:
	gfs2_log_unlock(sdp);
	unlock_buffer(bd->bd_bh);
}

static void buf_lo_incore_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
{
	struct list_head *head = &tr->tr_list_buf;
	struct gfs2_bufdata *bd;

	gfs2_log_lock(sdp);
	while (!