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

[Yunlong Song]

Hi Chao,
    Nice suggestion, I have sent out a new patch to implement it.

On 2017/7/29 8:19, Chao Yu wrote:

Hi Yunlong,

On 2017/7/27 20:13, Yunlong Song wrote:

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.

Could we cover __write_data_page of directory inode with this logic?

Thanks,

Signed-off-by: Yunlong Song <yunlong.s...@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