Re: [PATCH v2] f2fs: provide f2fs_balance_fs to __write_node_page

[Yunlong Song <yunlong.song@huawei.com>]

v1->v2, fix some dead lock problems under some heavy load test

On 2017/7/27 20:11, Yunlong Song wrote:
> Let node writeback also do f2fs_balance_fs to ensure there are always enough free
> segments.
>
> Signed-off-by: Yunlong Song <yunlong.song@huawei.com>
> ---
>   fs/f2fs/checkpoint.c |  2 +-
>   fs/f2fs/f2fs.h       |  2 +-
>   fs/f2fs/node.c       | 14 ++++++++------
>   3 files changed, 10 insertions(+), 8 deletions(-)
>
> diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
> index 5b876f6..3c84a25 100644
> --- a/fs/f2fs/checkpoint.c
> +++ b/fs/f2fs/checkpoint.c
> @@ -1017,7 +1017,7 @@ static int block_operations(struct f2fs_sb_info *sbi)
>   
>   	if (get_pages(sbi, F2FS_DIRTY_NODES)) {
>   		up_write(&sbi->node_write);
> -		err = sync_node_pages(sbi, &wbc);
> +		err = sync_node_pages(sbi, &wbc, false);
>   		if (err) {
>   			up_write(&sbi->node_change);
>   			f2fs_unlock_all(sbi);
> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> index 94a88b2..f69051b 100644
> --- a/fs/f2fs/f2fs.h
> +++ b/fs/f2fs/f2fs.h
> @@ -2293,7 +2293,7 @@ struct page *new_node_page(struct dnode_of_data *dn,
>   void move_node_page(struct page *node_page, int gc_type);
>   int fsync_node_pages(struct f2fs_sb_info *sbi, struct inode *inode,
>   			struct writeback_control *wbc, bool atomic);
> -int sync_node_pages(struct f2fs_sb_info *sbi, struct writeback_control *wbc);
> +int sync_node_pages(struct f2fs_sb_info *sbi, struct writeback_control *wbc, bool need);
>   void build_free_nids(struct f2fs_sb_info *sbi, bool sync, bool mount);
>   bool alloc_nid(struct f2fs_sb_info *sbi, nid_t *nid);
>   void alloc_nid_done(struct f2fs_sb_info *sbi, nid_t nid);
> diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
> index d53fe62..210ec25 100644
> --- a/fs/f2fs/node.c
> +++ b/fs/f2fs/node.c
> @@ -1326,7 +1326,7 @@ static struct page *last_fsync_dnode(struct f2fs_sb_info *sbi, nid_t ino)
>   }
>   
>   static int __write_node_page(struct page *page, bool atomic, bool *submitted,
> -				struct writeback_control *wbc)
> +				struct writeback_control *wbc, bool need)
>   {
>   	struct f2fs_sb_info *sbi = F2FS_P_SB(page);
>   	nid_t nid;
> @@ -1387,6 +1387,8 @@ static int __write_node_page(struct page *page, bool atomic, bool *submitted,
>   	}
>   
>   	unlock_page(page);
> +	if (need)
> +		f2fs_balance_fs(sbi, false);
>   
>   	if (unlikely(f2fs_cp_error(sbi))) {
>   		f2fs_submit_merged_write(sbi, NODE);
> @@ -1405,7 +1407,7 @@ static int __write_node_page(struct page *page, bool atomic, bool *submitted,
>   static int f2fs_write_node_page(struct page *page,
>   				struct writeback_control *wbc)
>   {
> -	return __write_node_page(page, false, NULL, wbc);
> +	return __write_node_page(page, false, NULL, wbc, false);
>   }
>   
>   int fsync_node_pages(struct f2fs_sb_info *sbi, struct inode *inode,
> @@ -1493,7 +1495,7 @@ int fsync_node_pages(struct f2fs_sb_info *sbi, struct inode *inode,
>   
>   			ret = __write_node_page(page, atomic &&
>   						page == last_page,
> -						&submitted, wbc);
> +						&submitted, wbc, true);
>   			if (ret) {
>   				unlock_page(page);
>   				f2fs_put_page(last_page, 0);
> @@ -1530,7 +1532,7 @@ int fsync_node_pages(struct f2fs_sb_info *sbi, struct inode *inode,
>   	return ret ? -EIO: 0;
>   }
>   
> -int sync_node_pages(struct f2fs_sb_info *sbi, struct writeback_control *wbc)
> +int sync_node_pages(struct f2fs_sb_info *sbi, struct writeback_control *wbc, bool need)
>   {
>   	pgoff_t index, end;
>   	struct pagevec pvec;
> @@ -1608,7 +1610,7 @@ int sync_node_pages(struct f2fs_sb_info *sbi, struct writeback_control *wbc)
>   			set_fsync_mark(page, 0);
>   			set_dentry_mark(page, 0);
>   
> -			ret = __write_node_page(page, false, &submitted, wbc);
> +			ret = __write_node_page(page, false, &submitted, wbc, need);
>   			if (ret)
>   				unlock_page(page);
>   			else if (submitted)
> @@ -1697,7 +1699,7 @@ static int f2fs_write_node_pages(struct address_space *mapping,
>   	diff = nr_pages_to_write(sbi, NODE, wbc);
>   	wbc->sync_mode = WB_SYNC_NONE;
>   	blk_start_plug(&plug);
> -	sync_node_pages(sbi, wbc);
> +	sync_node_pages(sbi, wbc, true);
>   	blk_finish_plug(&plug);
>   	wbc->nr_to_write = max((long)0, wbc->nr_to_write - diff);
>   	return 0;

-- 
Thanks,
Yunlong Song