Hi Chao,
On Tue, Sep 27, 2016 at 12:09:52AM +0800, Chao Yu wrote:
> From: Chao Yu <yuch...@huawei.com>
>
> In sync_node_pages, we won't check and commit last merged pages in private
> bio cache of f2fs, as these pages were taged as writeback, someone who is
> waiting for writebacking of the page will be blocked until the cache was
> committed by someone else.
>
> We need to commit node type bio cache to avoid potential deadlock or long
> delay of waiting writeback.
>
> Signed-off-by: Chao Yu <yuch...@huawei.com>
> ---
> fs/f2fs/node.c | 11 +++++++++--
> 1 file changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
> index 9faddcd..f73f774 100644
> --- a/fs/f2fs/node.c
> +++ b/fs/f2fs/node.c
> @@ -1416,6 +1416,7 @@ int sync_node_pages(struct f2fs_sb_info *sbi, struct
> writeback_control *wbc)
> struct pagevec pvec;
> int step = 0;
> int nwritten = 0;
> + int ret = 0;
>
> pagevec_init(&pvec, 0);
>
> @@ -1436,7 +1437,8 @@ next_step:
>
> if (unlikely(f2fs_cp_error(sbi))) {
> pagevec_release(&pvec);
> - return -EIO;
> + ret = -EIO;
> + goto out;
> }
>
> /*
> @@ -1487,6 +1489,8 @@ continue_unlock:
>
> if (NODE_MAPPING(sbi)->a_ops->writepage(page, wbc))
> unlock_page(page);
> + else
> + nwritten++;
>
> if (--wbc->nr_to_write == 0)
> break;
> @@ -1504,7 +1508,10 @@ continue_unlock:
> step++;
> goto next_step;
> }
> - return nwritten;
> +out:
> + if (nwritten)
> + f2fs_submit_merged_bio(sbi, NODE, WRITE);
IIRC, we don't need to flush this, since f2fs_submit_merged_bio_cond() would
handle this in f2fs_wait_on_page_writeback().
Thanks,
> + return ret;
> }
>
> int wait_on_node_pages_writeback(struct f2fs_sb_info *sbi, nid_t ino)
> --
> 2.7.2
