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SubjectRe: [f2fs-dev] [PATCH 3/3 V3] f2fs: introduce f2fs_cache_node_page() to add page into node_inode cache
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Hi,

Sorry for the noise.
Once I tested this patch, I recognized that I made a mistake:

f2fs_fill_super()
1. build_segment_manager()
-> restore_node_summary()
-> NULL pointer exception, due to no NAT cache.
2. build_node_manager()

So, we should not call get_node_info() prior to build_node_manager().
And, it's not easy to change the order of build_*_manager simply.

Let's consider in more details.
Thanks,

2013-12-09 (월), 13:35 +0800, Chao Yu:
> This patch introduces f2fs_cache_node_page(), in this function, page which is
> readed ahead will be copy to node_inode's mapping cache.
> It will avoid rereading these node pages.
>
> change log:
> o check validity of page by searching NAT suggested by Jaegeuk Kim.
> o add 'unlikely' for compiler optimization suggested by Jaegeuk Kim.
>
> Suggested-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
> Signed-off-by: Chao Yu <chao2.yu@samsung.com>
> ---
> fs/f2fs/node.c | 39 ++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 38 insertions(+), 1 deletion(-)
>
> diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
> index 099f06f..4c6da98 100644
> --- a/fs/f2fs/node.c
> +++ b/fs/f2fs/node.c
> @@ -1600,13 +1600,46 @@ static int ra_sum_pages(struct f2fs_sb_info *sbi, struct list_head *pages,
> return 0;
> }
>
> +/*
> + * f2fs_cache_node_page() check validaty of input page by searching NAT.
> + * Then, it will copy updated data of vaild page to node_inode cache.
> + */
> +void f2fs_cache_node_page(struct f2fs_sb_info *sbi, struct page *page,
> + nid_t nid, block_t blkaddr)
> +{
> + struct address_space *mapping = sbi->node_inode->i_mapping;
> + struct page *npage;
> + struct node_info ni;
> +
> + get_node_info(sbi, nid, &ni);
> +
> + if (ni.blk_addr != blkaddr)
> + return;
> +
> + npage = grab_cache_page(mapping, nid);
> + if (unlikely(!npage))
> + return;
> +
> + if (PageUptodate(npage)) {
> + f2fs_put_page(npage, 1);
> + return;
> + }
> +
> + memcpy(page_address(npage), page_address(page), PAGE_CACHE_SIZE);
> +
> + SetPageUptodate(npage);
> + f2fs_put_page(npage, 1);
> +
> + return;
> +}
> +
> int restore_node_summary(struct f2fs_sb_info *sbi,
> unsigned int segno, struct f2fs_summary_block *sum)
> {
> struct f2fs_node *rn;
> struct f2fs_summary *sum_entry;
> struct page *page, *tmp;
> - block_t addr;
> + block_t addr, blkaddr;
> int bio_blocks = MAX_BIO_BLOCKS(max_hw_blocks(sbi));
> int i, last_offset, nrpages, err = 0;
> LIST_HEAD(page_list);
> @@ -1624,6 +1657,7 @@ int restore_node_summary(struct f2fs_sb_info *sbi,
> if (err)
> return err;
>
> + blkaddr = addr;
> list_for_each_entry_safe(page, tmp, &page_list, lru) {
>
> lock_page(page);
> @@ -1633,6 +1667,8 @@ int restore_node_summary(struct f2fs_sb_info *sbi,
> sum_entry->version = 0;
> sum_entry->ofs_in_node = 0;
> sum_entry++;
> + f2fs_cache_node_page(sbi, page,
> + le32_to_cpu(rn->footer.nid), blkaddr);
> } else {
> err = -EIO;
> }
> @@ -1640,6 +1676,7 @@ int restore_node_summary(struct f2fs_sb_info *sbi,
> list_del(&page->lru);
> unlock_page(page);
> __free_pages(page, 0);
> + blkaddr++;
> }
> }
> return err;

--
Jaegeuk Kim
Samsung

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