path: root/fs/f2fs/checkpoint.c

/*
 * fs/f2fs/checkpoint.c
 *
 * Copyright (c) 2012 Samsung Electronics Co., Ltd.
 *             http://www.samsung.com/
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#include <linux/fs.h>
#include <linux/bio.h>
#include <linux/mpage.h>
#include <linux/writeback.h>
#include <linux/blkdev.h>
#include <linux/f2fs_fs.h>
#include <linux/pagevec.h>
#include <linux/swap.h>

#include "f2fs.h"
#include "node.h"
#include "segment.h"
#include <trace/events/f2fs.h>

static struct kmem_cache *orphan_entry_slab;
static struct kmem_cache *inode_entry_slab;

/*
 * We guarantee no failure on the returned page.
 */
struct page *grab_meta_page(struct f2fs_sb_info *sbi, pgoff_t index)
{
	struct address_space *mapping = META_MAPPING(sbi);
	struct page *page = NULL;
repeat:
	page = grab_cache_page(mapping, index);
	if (!page) {
		cond_resched();
		goto repeat;
	}

	/* We wait writeback only inside grab_meta_page() */
	wait_on_page_writeback(page);
	SetPageUptodate(page);
	return page;
}

/*
 * We guarantee no failure on the returned page.
 */
struct page *get_meta_page(struct f2fs_sb_info *sbi, pgoff_t index)
{
	struct address_space *mapping = META_MAPPING(sbi);
	struct page *page;
repeat:
	page = grab_cache_page(mapping, index);
	if (!page) {
		cond_resched();
		goto repeat;
	}
	if (PageUptodate(page))
		goto out;

	if (f2fs_submit_page_bio(sbi, page, index,
				READ_SYNC | REQ_META | REQ_PRIO))
		goto repeat;

	lock_page(page);
	if (unlikely(page->mapping != mapping)) {
		f2fs_put_page(page, 1);
		goto repeat;
	}
out:
	mark_page_accessed(page);
	return page;
}

static int f2fs_write_meta_page(struct page *page,
				struct writeback_control *wbc)
{
	struct inode *inode = page->mapping->host;
	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);

	/* Should not write any meta pages, if any IO error was occurred */
	if (unlikely(sbi->por_doing ||
			is_set_ckpt_flags(F2FS_CKPT(sbi), CP_ERROR_FLAG)))
		goto redirty_out;

	if (wbc->for_reclaim)
		goto redirty_out;

	wait_on_page_writeback(page);

	write_meta_page(sbi, page);
	dec_page_count(sbi, F2FS_DIRTY_META);
	unlock_page(page);
	return 0;

redirty_out:
	dec_page_count(sbi, F2FS_DIRTY_META);
	wbc->pages_skipped++;
	set_page_dirty(page);
	return AOP_WRITEPAGE_ACTIVATE;
}

static int f2fs_write_meta_pages(struct address_space *mapping,
				struct writeback_control *wbc)
{
	struct f2fs_sb_info *sbi = F2FS_SB(mapping->host->i_sb);
	int nrpages = MAX_BIO_BLOCKS(max_hw_blocks(sbi));
	long written;

	if (wbc->for_kupdate)
		return 0;

	/* collect a number of dirty meta pages and write together */
	if (get_pages(sbi, F2FS_DIRTY_META) < nrpages)
		return 0;

	/* if mounting is failed, skip writing node pages */
	mutex_lock(&sbi->cp_mutex);
	written = sync_meta_pages(sbi, META, nrpages);
	mutex_unlock(&sbi->cp_mutex);
	wbc->nr_to_write -= written;
	return 0;
}

long sync_meta_pages(struct f2fs_sb_info *sbi, enum page_type type,
						long nr_to_write)
{
	struct address_space *mapping = META_MAPPING(sbi);
	pgoff_t index = 0, end = LONG_MAX;
	struct pagevec pvec;
	long nwritten = 0;
	struct writeback_control wbc = {
		.for_reclaim = 0,
	};

	pagevec_init(&pvec, 0);

	while (index <= end) {
		int i, nr_pages;
		nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
				PAGECACHE_TAG_DIRTY,
				min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1);
		if (unlikely(nr_pages == 0))
			break;

		for (i = 0; i < nr_pages; i++) {
			struct page *page = pvec.pages[i];
			lock_page(page);
			f2fs_bug_on(page->mapping != mapping);
			f2fs_bug_on(!PageDirty(page));
			clear_page_dirty_for_io(page);
			if (f2fs_write_meta_page(page, &wbc)) {
				unlock_page(page);
				break;
			}
			nwritten++;
			if (unlikely(nwritten >= nr_to_write))
				break;
		}
		pagevec_release(&pvec);
		cond_resched();
	}

	if (nwritten)
		f2fs_submit_merged_bio(sbi, type, WRITE);

	return nwritten;
}

static int f2fs_set_meta_page_dirty(struct page *page)
{
	struct address_space *mapping = page->mapping;
	struct f2fs_sb_info *sbi = F2FS_SB(mapping->host->i_sb);

	trace_f2fs_set_page_dirty(page, META);

	SetPageUptodate(page);
	if (!PageDirty(page)) {
		__set_page_dirty_nobuffers(page);
		inc_page_count(sbi, F2FS_DIRTY_META);
		return 1;
	}