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

static struct kmem_cache *ino_entry_slab;
struct kmem_cache *f2fs_inode_entry_slab;

void f2fs_stop_checkpoint(struct f2fs_sb_info *sbi, bool end_io)
{
	set_ckpt_flags(sbi, CP_ERROR_FLAG);
	if (!end_io)
		f2fs_flush_merged_writes(sbi);
}

/*
 * We guarantee no failure on the returned page.
 */
struct page *f2fs_grab_meta_page(struct f2fs_sb_info *sbi, pgoff_t index)
{
	struct address_space *mapping = META_MAPPING(sbi);
	struct page *page = NULL;
repeat:
	page = f2fs_grab_cache_page(mapping, index, false);
	if (!page) {
		cond_resched();
		goto repeat;
	}
	f2fs_wait_on_page_writeback(page, META, true);
	if (!PageUptodate(page))
		SetPageUptodate(page);
	return page;
}

/*
 * We guarantee no failure on the returned page.
 */
static struct page *__get_meta_page(struct f2fs_sb_info *sbi, pgoff_t index,
							bool is_meta)
{
	struct address_space *mapping = META_MAPPING(sbi);
	struct page *page;
	struct f2fs_io_info fio = {
		.sbi = sbi,
		.type = META,
		.op = REQ_OP_READ,
		.op_flags = REQ_META | REQ_PRIO,
		.old_blkaddr = index,
		.new_blkaddr = index,
		.encrypted_page = NULL,
		.is_meta = is_meta,
	};

	if (unlikely(!is_meta))
		fio.op_flags &= ~REQ_META;
repeat:
	page = f2fs_grab_cache_page(mapping, index, false);
	if (!page) {
		cond_resched();
		goto repeat;
	}
	if (PageUptodate(page))
		goto out;

	fio.page = page;

	if (f2fs_submit_page_bio(&fio)) {
		f2fs_put_page(page, 1);
		goto repeat;
	}

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

	/*
	 * if there is any IO error when accessing device, make our filesystem
	 * readonly and make sure do not write checkpoint with non-uptodate
	 * meta page.
	 */
	if (unlikely(!PageUptodate(page))) {
		memset(page_address(page), 0, PAGE_SIZE);
		f2fs_stop_checkpoint(sbi, false);
	}
out:
	return page;
}

struct page *f2fs_get_meta_page(struct f2fs_sb_info *sbi, pgoff_t index)
{
	return __get_meta_page(sbi, index, true);
}

/* for POR only */
struct page *f2fs_get_tmp_page(struct f2fs_sb_info *sbi, pgoff_t index)
{
	return __get_meta_page(sbi, index, false);
}

bool f2fs_is_valid_meta_blkaddr(struct f2fs_sb_info *sbi,
					block_t blkaddr, int type)
{
	switch (type) {
	case META_NAT:
		break;
	case META_SIT:
		if (unlikely(blkaddr >= SIT_BLK_CNT(sbi)))
			return false;
		break;
	case META_SSA:
		if (unlikely(blkaddr >= MAIN_BLKADDR(sbi) ||
			blkaddr < SM_I(sbi)->ssa_blkaddr))
			return false;
		break;
	case META_CP:
		if (unlikely(blkaddr >= SIT_I(sbi)->sit_base_addr ||
			blkaddr < __start_cp_addr(sbi)))
			return false;
		break;
	case META_POR:
		if (unlikely(blkaddr >= MAX_BLKADDR(sbi) ||
			blkaddr < MAIN_BLKADDR(sbi)))
			return false;
		break;
	default:
		BUG();
	}

	return true;
}

/*
 * Readahead CP/NAT/SIT/SSA pages
 */
int f2fs_ra_meta_pages(struct f2fs_sb_info *sbi, block_t start, int nrpages,
							int type, bool sync)
{
	struct page *page;
	block_t blkno = start;
	struct f2fs_io_info fio = {
		.sbi = sbi,
		.type = META,
		.op = REQ_OP_READ,
		.op_flags = sync ? (REQ_META | REQ_PRIO) : REQ_RAHEAD,
		.encrypted_page = NULL,
		.in_list = false,
		.is_meta = (type != META_POR),
	};
	struct blk_plug plug;

	if (unlikely(type == META_POR))
		fio.op_flags &= ~REQ_META;

	blk_start_plug(&plug);
	for (; nrpages-- > 0; blkno++) {

		if (!f2fs_is_valid_meta_blkaddr(sbi, blkno, type))
			goto out;

		switch (type) {
		case META_NAT:
			if (unlikely(blkno >=
					NAT_BLOCK_OFFSET(NM_I(sbi)->max_nid)))
				blkno = 0;
			/* get nat block addr */
			fio.new_blkaddr = current_nat_addr(sbi,
					blkno * NAT_ENTRY_PER_BLOCK);
			break;
		case META_SIT:
			/* get sit block addr */
			fio.new_blkaddr = current_sit_addr(sbi,
					blkno * SIT_ENTRY_PER_BLOCK);
			break;
		case META_SSA:
		case META_CP:
		case META_POR:
			fio.new_blkaddr = blkno;
			break;
		default:
			BUG();
		}

		page = f2fs_grab_cache_page(META_MAPPING(sbi),
						fio.new_blkaddr, false);
		if (!page)
			continue;
		if (PageUptodate(page)) {
			f2fs_put_page(page, 1);
			continue;
		}

		fio.page = page;
		f2fs_submit_page_bio(&fio);
		f2fs_put_page(page, 0);
	}
out:
	blk_finish_plug(&plug);
	return blkno - start;
}

void f2fs_ra_meta_pages_cond(struct f2fs_sb_info *sbi, pgoff_t index)
{
	struct page *page;
	bool readahead = false;

	page = find_get_page(META_MAPPING(sbi), index);
	if (!page || !PageUptodate(page))
		readahead = true;
	f2fs_put_page(page, 0);

	if (readahead)
		f2fs_ra_meta_pages(sbi, index, BIO_MAX_PAGES, META_POR, true);
}

static int __f2fs_write_meta_page(struct page *page,
				struct writeback_control *wbc,
				enum iostat_type io_type)
{
	struct f2fs_sb_info *sbi = F2FS_P_SB(page);

	trace_f2fs_writepage(page, META);

	if (unlikely(f2fs_cp_error(sbi))) {
		dec_page_count(sbi, F2FS_DIRTY_META);
		unlock_page(page);
		return 0;
	}
	if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
		goto redirty_out;
	if (wbc->for_reclaim && page->index < GET_SUM_BLOCK(sbi, 0))
		goto redirty_out;

	f2fs_do_write_meta_page(sbi, page, io_type);
	dec_page_count(sbi, F2FS_DIRTY_META);

	if (wbc->for_reclaim)
		f2fs_submit_merged_write_cond(sbi, page->mapping->host,
						0, page->index, META);

	unlock_page(page);

	if (unlikely(f2fs_cp_error(sbi)))
		f2fs_submit_merged_write(sbi, META);

	return 0;

redirty_out:
	redirty_page_for_writepage(wbc, page);
	return AOP_WRITEPAGE_ACTIVATE;
}

static int f2fs_write_meta_page(struct page *page,
				struct writeback_control *wbc)
{
	return __f2fs_write_meta_page(page, wbc, FS_META_IO);
}

static int f2fs_write_meta_pages(struct address_space *mapping,
				struct writeback_control *wbc)
{
	struct f2fs_sb_info *sbi = F2FS_M_SB(mapping);
	long diff, written;

	if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
		goto skip_write;

	/* collect a number of dirty meta pages and write together */
	if (wbc->for_kupdate ||
		get_pages(sbi, F2FS_DIRTY_META) < nr_pages_to_skip(sbi, META))
		goto skip_write;

	/* if locked failed, cp will flush dirty pages instead */
	if (!mutex_trylock(&sbi->cp_mutex))
		goto skip_write;

	trace_f2fs_writepages(mapping->host, wbc, META);
	diff = nr_pages_to_write(sbi, META, wbc);
	written = f2fs_sync_meta_pages(sbi, META, wbc->nr_to_write, FS_META_IO);
	mutex_unlock(&sbi->cp_mutex);
	wbc->nr_to_write = max((long)0, wbc->nr_to_write - written - diff);
	return 0;

skip_write:
	wbc->pages_skipped += get_pages(sbi, F2FS_DIRTY_META);
	trace_f2fs_writepages(mapping->host, wbc, META);
	return 0;
}

long f2fs_sync_meta_pages(struct f2fs_sb_info *sbi, enum page_type type,
				long nr_to_write, enum iostat_type io_type)
{
	struct address_space *mapping = META_MAPPING(sbi);
	pgoff_t index = 0, prev = ULONG_MAX;
	struct pagevec pvec;
	long nwritten = 0;
	int nr_pages;
	struct writeback_control wbc = {
		.for_reclaim = 0,
	};
	struct blk_plug plug;

	pagevec_init(&pvec);

	blk_start_plug(&plug);

	while ((nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
				PAGECACHE_TAG_DIRTY))) {
		int i;

		for (i = 0; i < nr_pages; i++) {
			struct page *page = pvec.pages[i];

			if (prev == ULONG_MAX)
				prev = page->index - 1;
			if (nr_to_write != LONG_MAX && page->index != prev + 1) {
				pagevec_release(&pvec);
				goto stop;
			}

			lock_page(page);

			if (unlikely(page->mapping != mapping)) {
continue_unlock:
				unlock_page(page);
				continue;
			}
			if (!PageDirty(page)) {
				/* someone wrote it for us */
				goto continue_unlock;
			}

			f2fs_wait_on_page_writeback(page, META, true);

			BUG_ON(PageWriteback(page));
			if (!clear_page_dirty_for_io(page))
				goto continue_unlock;

			if (__f2fs_write_meta_page(page, &wbc,