On 2017/4/22 18:06, Yunlei He wrote:
> This patch seperate nat page read io from nat_tree_lock.
>
> -lock_page
> -get_node_info()
> -current_nat_addr
>
> ...... -> write_checkpoint
>
> -get_meta_page
>
> Because we lock node page, we can make sure no other threads
> modify this nid concurrently. So we just obtain current_nat_addr
> under nat_tree_lock, node info is always same in both nat pack.
>
> Signed-off-by: Yunlei He <heyun...@huawei.com>
Reviewed-by: Chao Yu <yuch...@huawei.com>
Thanks,
> ---
> fs/f2fs/node.c | 11 ++++++++---
> 1 file changed, 8 insertions(+), 3 deletions(-)
>
> diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
> index ad54e90..b99e318 100644
> --- a/fs/f2fs/node.c
> +++ b/fs/f2fs/node.c
> @@ -376,6 +376,7 @@ void get_node_info(struct f2fs_sb_info *sbi, nid_t nid,
> struct node_info *ni)
> struct page *page = NULL;
> struct f2fs_nat_entry ne;
> struct nat_entry *e;
> + pgoff_t index;
> int i;
>
> ni->nid = nid;
> @@ -401,17 +402,21 @@ void get_node_info(struct f2fs_sb_info *sbi, nid_t nid,
> struct node_info *ni)
> node_info_from_raw_nat(ni, &ne);
> }
> up_read(&curseg->journal_rwsem);
> - if (i >= 0)
> + if (i >= 0) {
> + up_read(&nm_i->nat_tree_lock);
> goto cache;
> + }
>
> /* Fill node_info from nat page */
> - page = get_current_nat_page(sbi, start_nid);
> + index = current_nat_addr(sbi, nid);
> + up_read(&nm_i->nat_tree_lock);
> +
> + page = get_meta_page(sbi, index);
> nat_blk = (struct f2fs_nat_block *)page_address(page);
> ne = nat_blk->entries[nid - start_nid];
> node_info_from_raw_nat(ni, &ne);
> f2fs_put_page(page, 1);
> cache:
> - up_read(&nm_i->nat_tree_lock);
> /* cache nat entry */
> down_write(&nm_i->nat_tree_lock);
> cache_nat_entry(sbi, nid, &ne);
>
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