Hi Chao,
Sorry for the delay.
When I tested this patch, a deadlock was occurred, so I couldn't afford
to look inside in more detail.
When I see again, there is a bug wrt blkno.
Please see below.
2014-01-28 (화), 10:28 +0800, Chao Yu:
> This patch help us to cleanup the readahead code by merging ra_{sit,nat}_pages
> function into ra_meta_pages.
> Additionally the new function is used to readahead cp block in
> recover_orphan_inodes.
>
> Signed-off-by: Chao Yu <chao2.yu@xxxxxxxxxxx>
> ---
> fs/f2fs/checkpoint.c | 78 ++++++++++++++++++++++++++++++++++++++++++++++++++
> fs/f2fs/f2fs.h | 10 +++++++
> fs/f2fs/node.c | 38 +-----------------------
> fs/f2fs/segment.c | 43 +---------------------------
> 4 files changed, 90 insertions(+), 79 deletions(-)
>
> diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
> index 293d048..a1986c3 100644
> --- a/fs/f2fs/checkpoint.c
> +++ b/fs/f2fs/checkpoint.c
> @@ -75,6 +75,82 @@ out:
> return page;
> }
>
> +inline int get_max_meta_blks(struct f2fs_sb_info *sbi, int type)
> +{
> + switch (type) {
> + case META_NAT:
> + return NM_I(sbi)->max_nid / NAT_ENTRY_PER_BLOCK;
> + case META_SIT:
> + return SIT_BLK_CNT(sbi);
> + case META_CP:
> + return 0;
> + default:
> + BUG();
> + }
> +}
> +
> +/*
> + * Readahead CP/NAT/SIT pages
> + */
> +int ra_meta_pages(struct f2fs_sb_info *sbi, int start, int nrpages, int type)
> +{
> + struct address_space *mapping = sbi->meta_inode->i_mapping;
We don't need to do this. Instead, we can use META_MAPPING(sbi) below.
> + struct page *page;
> + block_t blk_addr, prev_blk_addr = 0;
> + int blkno = start;
> + int max_blks = get_max_meta_blks(sbi, type);
block_t prev_blk_addr = 0;
struct page *page;
int blkno = start;
int max_blks = get_max_meta_blks(sbi, type);
> + struct f2fs_io_info fio = {
> + .type = META,
> + .rw = READ_SYNC | REQ_META | REQ_PRIO
> + };
> +
> + for (blkno = start; blkno < start + nrpages; blkno++) {
for (; nrpages-- > 0; blkno++) {
block_t blk_addr;
--> In the case of META_NAT, blkno becomes 0 if it hits max_blks.
So, we should not use *blkno < start + nrpages*.
> +
> + switch (type) {
> + case META_NAT:
> + /* get nat block addr */
> + if (unlikely(blkno >= max_blks))
> + blkno = 0;
> + blk_addr = current_nat_addr(sbi,
> + blkno * NAT_ENTRY_PER_BLOCK);
> + break;
> + case META_SIT:
> + /* get sit block addr */
> + if (unlikely(blkno >= max_blks))
> + goto out;
> + blk_addr = current_sit_addr(sbi,
> + blkno * SIT_ENTRY_PER_BLOCK);
> + if (blkno != start && prev_blk_addr + 1 != blk_addr)
> + goto out;
> + prev_blk_addr = blk_addr;
> + break;
> + case META_CP:
> + /* get cp block addr */
> + blk_addr = blkno;
> + break;
> + default:
> + BUG();
> + }
> +
> + page = grab_cache_page(mapping, blk_addr);
page = grab_cache_page(META_MAPPING(sbi), blk_addr);
> + if (!page)
> + continue;
> + if (PageUptodate(page)) {
> + mark_page_accessed(page);
> + f2fs_put_page(page, 1);
> + continue;
> + }
> +
> + f2fs_submit_page_mbio(sbi, page, blk_addr, &fio);
> + mark_page_accessed(page);
> + f2fs_put_page(page, 0);
> + }
> +out:
> + f2fs_submit_merged_bio(sbi, META, READ);
> + return blkno - start;
> +}
> +
> static int f2fs_write_meta_page(struct page *page,
> struct writeback_control *wbc)
> {
> @@ -285,6 +361,8 @@ void recover_orphan_inodes(struct f2fs_sb_info *sbi)
> start_blk = __start_cp_addr(sbi) + 1;
> orphan_blkaddr = __start_sum_addr(sbi) - 1;
>
> + ra_meta_pages(sbi, start_blk, orphan_blkaddr, META_CP);
> +
> for (i = 0; i < orphan_blkaddr; i++) {
> struct page *page = get_meta_page(sbi, start_blk + i);
> struct f2fs_orphan_block *orphan_blk;
> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> index af51a0b..69ffc1b 100644
> --- a/fs/f2fs/f2fs.h
> +++ b/fs/f2fs/f2fs.h
> @@ -88,6 +88,15 @@ enum {
> SIT_BITMAP
> };
>
> +/*
> + * For CP/NAT/SIT readahead
> + */
> +enum {
> + META_CP,
> + META_NAT,
> + META_SIT
> +};
> +
> /* for the list of orphan inodes */
> struct orphan_inode_entry {
> struct list_head list; /* list head */
> @@ -1158,6 +1167,7 @@ void destroy_segment_manager_caches(void);
> */
> struct page *grab_meta_page(struct f2fs_sb_info *, pgoff_t);
> struct page *get_meta_page(struct f2fs_sb_info *, pgoff_t);
> +int ra_meta_pages(struct f2fs_sb_info *, int, int, int);
> long sync_meta_pages(struct f2fs_sb_info *, enum page_type, long);
> int acquire_orphan_inode(struct f2fs_sb_info *);
> void release_orphan_inode(struct f2fs_sb_info *);
> diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
> index b0649b7..2f7ae6f 100644
> --- a/fs/f2fs/node.c
> +++ b/fs/f2fs/node.c
> @@ -82,42 +82,6 @@ static struct page *get_next_nat_page(struct f2fs_sb_info *sbi, nid_t nid)
> return dst_page;
> }
>
> -/*
> - * Readahead NAT pages
> - */
> -static void ra_nat_pages(struct f2fs_sb_info *sbi, int nid)
> -{
> - struct address_space *mapping = META_MAPPING(sbi);
> - struct f2fs_nm_info *nm_i = NM_I(sbi);
> - struct page *page;
> - pgoff_t index;
> - int i;
> - struct f2fs_io_info fio = {
> - .type = META,
> - .rw = READ_SYNC | REQ_META | REQ_PRIO
> - };
> -
> -
> - for (i = 0; i < FREE_NID_PAGES; i++, nid += NAT_ENTRY_PER_BLOCK) {
> - if (unlikely(nid >= nm_i->max_nid))
> - nid = 0;
> - index = current_nat_addr(sbi, nid);
> -
> - page = grab_cache_page(mapping, index);
> - if (!page)
> - continue;
> - if (PageUptodate(page)) {
> - mark_page_accessed(page);
> - f2fs_put_page(page, 1);
> - continue;
> - }
> - f2fs_submit_page_mbio(sbi, page, index, &fio);
> - mark_page_accessed(page);
> - f2fs_put_page(page, 0);
> - }
> - f2fs_submit_merged_bio(sbi, META, READ);
> -}
> -
> static struct nat_entry *__lookup_nat_cache(struct f2fs_nm_info *nm_i, nid_t n)
> {
> return radix_tree_lookup(&nm_i->nat_root, n);
> @@ -1413,7 +1377,7 @@ static void build_free_nids(struct f2fs_sb_info *sbi)
> return;
>
> /* readahead nat pages to be scanned */
> - ra_nat_pages(sbi, nid);
> + ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), FREE_NID_PAGES, META_NAT);
>
> while (1) {
> struct page *page = get_current_nat_page(sbi, nid);
> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
> index 7caac5f..4c2b35b 100644
> --- a/fs/f2fs/segment.c
> +++ b/fs/f2fs/segment.c
> @@ -1583,47 +1583,6 @@ static int build_curseg(struct f2fs_sb_info *sbi)
> return restore_curseg_summaries(sbi);
> }
>
> -static int ra_sit_pages(struct f2fs_sb_info *sbi, int start, int nrpages)
> -{
> - struct address_space *mapping = META_MAPPING(sbi);
> - struct page *page;
> - block_t blk_addr, prev_blk_addr = 0;
> - int sit_blk_cnt = SIT_BLK_CNT(sbi);
> - int blkno = start;
> - struct f2fs_io_info fio = {
> - .type = META,
> - .rw = READ_SYNC | REQ_META | REQ_PRIO
> - };
> -
> - for (; blkno < start + nrpages && blkno < sit_blk_cnt; blkno++) {
> -
> - blk_addr = current_sit_addr(sbi, blkno * SIT_ENTRY_PER_BLOCK);
> -
> - if (blkno != start && prev_blk_addr + 1 != blk_addr)
> - break;
> - prev_blk_addr = blk_addr;
> -repeat:
> - page = grab_cache_page(mapping, blk_addr);
> - if (!page) {
> - cond_resched();
> - goto repeat;
> - }
> - if (PageUptodate(page)) {
> - mark_page_accessed(page);
> - f2fs_put_page(page, 1);
> - continue;
> - }
> -
> - f2fs_submit_page_mbio(sbi, page, blk_addr, &fio);
> -
> - mark_page_accessed(page);
> - f2fs_put_page(page, 0);
> - }
> -
> - f2fs_submit_merged_bio(sbi, META, READ);
> - return blkno - start;
> -}
> -
> static void build_sit_entries(struct f2fs_sb_info *sbi)
> {
> struct sit_info *sit_i = SIT_I(sbi);
> @@ -1635,7 +1594,7 @@ static void build_sit_entries(struct f2fs_sb_info *sbi)
> int nrpages = MAX_BIO_BLOCKS(max_hw_blocks(sbi));
>
> do {
> - readed = ra_sit_pages(sbi, start_blk, nrpages);
> + readed = ra_meta_pages(sbi, start_blk, nrpages, META_SIT);
>
> start = start_blk * sit_i->sents_per_block;
> end = (start_blk + readed) * sit_i->sents_per_block;
--
Jaegeuk Kim
Samsung
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