path: root/fs/gfs2/meta_io.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 v.2.
 */

#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/completion.h>
#include <linux/buffer_head.h>
#include <linux/mm.h>
#include <linux/pagemap.h>
#include <linux/writeback.h>
#include <linux/swap.h>
#include <linux/delay.h>
#include <linux/gfs2_ondisk.h>

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

#define buffer_busy(bh) \
((bh)->b_state & ((1ul << BH_Dirty) | (1ul << BH_Lock) | (1ul << BH_Pinned)))
#define buffer_in_io(bh) \
((bh)->b_state & ((1ul << BH_Dirty) | (1ul << BH_Lock)))

static int aspace_get_block(struct inode *inode, sector_t lblock,
			    struct buffer_head *bh_result, int create)
{
	gfs2_assert_warn(inode->i_sb->s_fs_info, 0);
	return -EOPNOTSUPP;
}

static int gfs2_aspace_writepage(struct page *page,
				 struct writeback_control *wbc)
{
	return block_write_full_page(page, aspace_get_block, wbc);
}

/**
 * stuck_releasepage - We're stuck in gfs2_releasepage().  Print stuff out.
 * @bh: the buffer we're stuck on
 *
 */

static void stuck_releasepage(struct buffer_head *bh)
{
	struct inode *inode = bh->b_page->mapping->host;
	struct gfs2_sbd *sdp = inode->i_sb->s_fs_info;
	struct gfs2_bufdata *bd = bh->b_private;
	struct gfs2_glock *gl;

	fs_warn(sdp, "stuck in gfs2_releasepage() %p\n", inode);
	fs_warn(sdp, "blkno = %llu, bh->b_count = %d\n",
		(unsigned long long)bh->b_blocknr, atomic_read(&bh->b_count));
	fs_warn(sdp, "pinned = %u\n", buffer_pinned(bh));
	fs_warn(sdp, "bh->b_private = %s\n", (bd) ? "!NULL" : "NULL");

	if (!bd)
		return;

	gl = bd->bd_gl;

	fs_warn(sdp, "gl = (%u, %llu)\n", 
		gl->gl_name.ln_type, (unsigned long long)gl->gl_name.ln_number);

	fs_warn(sdp, "bd_list_tr = %s, bd_le.le_list = %s\n",
		(list_empty(&bd->bd_list_tr)) ? "no" : "yes",
		(list_empty(&bd->bd_le.le_list)) ? "no" : "yes");

	if (gl->gl_ops == &gfs2_inode_glops) {
		struct gfs2_inode *ip = gl->gl_object;
		unsigned int x;

		if (!ip)
			return;

		fs_warn(sdp, "ip = %llu %llu\n",
			(unsigned long long)ip->i_num.no_formal_ino,
			(unsigned long long)ip->i_num.no_addr);
		fs_warn(sdp, "ip->i_count = %d, ip->i_vnode = %s\n",
			atomic_read(&ip->i_count),
			(ip->i_vnode) ? "!NULL" : "NULL");

		for (x = 0; x < GFS2_MAX_META_HEIGHT; x++)
			fs_warn(sdp, "ip->i_cache[%u] = %s\n",
				x, (ip->i_cache[x]) ? "!NULL" : "NULL");
	}
}

/**
 * gfs2_aspace_releasepage - free the metadata associated with a page
 * @page: the page that's being released
 * @gfp_mask: passed from Linux VFS, ignored by us
 *
 * Call try_to_free_buffers() if the buffers in this page can be
 * released.
 *
 * Returns: 0
 */

static int gfs2_aspace_releasepage(struct page *page, gfp_t gfp_mask)
{
	struct inode *aspace = page->mapping->host;
	struct gfs2_sbd *sdp = aspace->i_sb->s_fs_info;
	struct buffer_head *bh, *head;
	struct gfs2_bufdata *bd;
	unsigned long t;

	if (!page_has_buffers(page))
		goto out;

	head = bh = page_buffers(page);
	do {
		t = jiffies;

		while (atomic_read(&bh->b_count)) {
			if (atomic_read(&aspace->i_writecount)) {
				if (time_after_eq(jiffies, t +
				    gfs2_tune_get(sdp, gt_stall_secs) * HZ)) {
					stuck_releasepage(bh);
					t = jiffies;
				}

				yield();
				continue;
			}

			return 0;
		}

		gfs2_assert_warn(sdp, !buffer_pinned(bh));

		bd = bh->b_private;
		if (bd) {
			gfs2_assert_warn(sdp, bd->bd_bh == bh);
			gfs2_assert_warn(sdp, list_empty(&bd->bd_list_tr));
			gfs2_assert_warn(sdp, list_empty(&bd->bd_le.le_list));
			gfs2_assert_warn(sdp, !bd->bd_ail);
			kmem_cache_free(gfs2_bufdata_cachep, bd);
			bh->b_private = NULL;
		}

		bh = bh->b_this_page;
	}
	while (bh != head);

 out:
	return try_to_free_buffers(page);
}

static struct address_space_operations aspace_aops = {
	.writepage = gfs2_aspace_writepage,
	.