path: root/fs/gfs2/log.c

/*
 * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
 * Copyright (C) 2004-2007 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/crc32.h>
#include <linux/lm_interface.h>
#include <linux/delay.h>
#include <linux/kthread.h>
#include <linux/freezer.h>
#include <linux/bio.h>

#include "gfs2.h"
#include "incore.h"
#include "bmap.h"
#include "glock.h"
#include "log.h"
#include "lops.h"
#include "meta_io.h"
#include "util.h"
#include "dir.h"

#define PULL 1

/**
 * gfs2_struct2blk - compute stuff
 * @sdp: the filesystem
 * @nstruct: the number of structures
 * @ssize: the size of the structures
 *
 * Compute the number of log descriptor blocks needed to hold a certain number
 * of structures of a certain size.
 *
 * Returns: the number of blocks needed (minimum is always 1)
 */

unsigned int gfs2_struct2blk(struct gfs2_sbd *sdp, unsigned int nstruct,
			     unsigned int ssize)
{
	unsigned int blks;
	unsigned int first, second;

	blks = 1;
	first = (sdp->sd_sb.sb_bsize - sizeof(struct gfs2_log_descriptor)) / ssize;

	if (nstruct > first) {
		second = (sdp->sd_sb.sb_bsize -
			  sizeof(struct gfs2_meta_header)) / ssize;
		blks += DIV_ROUND_UP(nstruct - first, second);
	}

	return blks;
}

/**
 * gfs2_remove_from_ail - Remove an entry from the ail lists, updating counters
 * @mapping: The associated mapping (maybe NULL)
 * @bd: The gfs2_bufdata to remove
 *
 * The log lock _must_ be held when calling this function
 *
 */

void gfs2_remove_from_ail(struct gfs2_bufdata *bd)
{
	bd->bd_ail = NULL;
	list_del_init(&bd->bd_ail_st_list);
	list_del_init(&bd->bd_ail_gl_list);
	atomic_dec(&bd->bd_gl->gl_ail_count);
	brelse(bd->bd_bh);
}

/**
 * gfs2_ail1_start_one - Start I/O on a part of the AIL
 * @sdp: the filesystem
 * @tr: the part of the AIL
 *
 */

static void gfs2_ail1_start_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
__releases(&sdp->sd_log_lock)
__acquires(&sdp->sd_log_lock)
{
	struct gfs2_bufdata *bd, *s;
	struct buffer_head *bh;
	int retry;

	do {
		retry = 0;

		list_for_each_entry_safe_reverse(bd, s, &ai->ai_ail1_list,
						 bd_ail_st_list) {
			bh = bd->bd_bh;

			gfs2_assert(sdp, bd->bd_ail == ai);

			if (!buffer_busy(bh)) {
				if (!buffer_uptodate(bh))
					gfs2_io_error_bh(sdp, bh);
				list_move(&bd->bd_ail_st_list, &ai->ai_ail2_list);
				continue;
			}

			if (!buffer_dirty(bh))
				continue;

			list_move(&bd->bd_ail_st_list, &ai->ai_ail1_list);

			get_bh(bh);
			gfs2_log_unlock(sdp);
			lock_buffer(bh);
			if (test_clear_buffer_dirty(bh)) {
				bh->b_end_io = end_buffer_write_sync;
				submit_bh(WRITE, bh);
			} else {
				unlock_buffer(bh);
				brelse(bh);
			}
			gfs2_log_lock(sdp);

			retry = 1;
			break;
		}
	} while (retry);
}

/**
 * gfs2_ail1_empty_one - Check whether or not a trans in the AIL has been synced
 * @sdp: the filesystem
 * @ai: the AIL entry
 *
 */

static int gfs2_ail1_empty_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai, int flags)
{
	struct gfs2_bufdata *bd, *s;
	struct buffer_head *bh;

	list_for_each_entry_safe_reverse(bd, s, &ai->ai_ail1_list,
					 bd_ail_st_list) {
		bh = bd->bd_bh;

		gfs2_assert(sdp, bd->bd_ail == ai);

		if (buffer_busy(bh)) {
			if (flags & DIO_ALL)
				continue;
			else
				break;
		}

		if (!buffer_uptodate(bh))
			gfs2_io_error_bh(sdp, bh);

		list_move(&bd->bd_ail_st_list, &ai->ai_ail2_list);
	}

	return list_empty(&ai->ai_ail1_list);
}

static void gfs2_ail1_start(struct gfs2_sbd *sdp, int flags)
{
	struct list_head *head;
	u64 sync_gen;
	struct list_head *first;
	struct gfs2_ail *first_ai, *ai, *tmp;
	int done = 0;

	gfs2_log_lock(sdp);
	head = &sdp->sd_ail1_list;
	if (list_empty(head)) {
		gfs2_log_unlock(sdp);
		return;
	}
	sync_gen = sdp->sd_ail_sync_gen++;

	first = head->prev;
	first_ai = list_entry(first, struct gfs2_ail, ai_list);
	first_ai->ai_sync_gen = sync_gen;
	gfs2_ail1_start_one(sdp, first_ai); /* This may drop log lock */

	if (flags & DIO_ALL)
		first = NULL;

	while(!done) {
		if (first