3 files changed, 22 insertions, 2 deletions

diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index 4aa521aa9bc3..890e23d208a8 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -762,6 +762,12 @@ static void do_checkpoint(struct f2fs_sb_info *sbi, bool is_umount)
         void *kaddr;
         int i;
 
+        /*
+         * This avoids to conduct wrong roll-forward operations and uses
+         * metapages, so should be called prior to sync_meta_pages below.
+         */
+        discard_next_dnode(sbi);
+
         /* Flush all the NAT/SIT pages */
         while (get_pages(sbi, F2FS_DIRTY_META))
                 sync_meta_pages(sbi, META, LONG_MAX);
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 2ecac8312359..2c5a5dadae65 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -1179,6 +1179,7 @@ int f2fs_issue_flush(struct f2fs_sb_info *);
 void invalidate_blocks(struct f2fs_sb_info *, block_t);
 void refresh_sit_entry(struct f2fs_sb_info *, block_t, block_t);
 void clear_prefree_segments(struct f2fs_sb_info *);
+void discard_next_dnode(struct f2fs_sb_info *);
 int npages_for_summary_flush(struct f2fs_sb_info *);
 void allocate_new_segments(struct f2fs_sb_info *);
 struct page *get_sum_page(struct f2fs_sb_info *, unsigned int);
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 1e264e761f71..9993f94848fc 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -335,13 +335,26 @@ static void locate_dirty_segment(struct f2fs_sb_info *sbi, unsigned int segno)
         mutex_unlock(&dirty_i->seglist_lock);
 }
 
-static void f2fs_issue_discard(struct f2fs_sb_info *sbi,
+static int f2fs_issue_discard(struct f2fs_sb_info *sbi,
                                 block_t blkstart, block_t blklen)
 {
         sector_t start = SECTOR_FROM_BLOCK(sbi, blkstart);
         sector_t len = SECTOR_FROM_BLOCK(sbi, blklen);
-        blkdev_issue_discard(sbi->sb->s_bdev, start, len, GFP_NOFS, 0);
         trace_f2fs_issue_discard(sbi->sb, blkstart, blklen);
+        return blkdev_issue_discard(sbi->sb->s_bdev, start, len, GFP_NOFS, 0);
+}
+
+void discard_next_dnode(struct f2fs_sb_info *sbi)
+{
+        struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_WARM_NODE);
+        block_t blkaddr = NEXT_FREE_BLKADDR(sbi, curseg);
+
+        if (f2fs_issue_discard(sbi, blkaddr, 1)) {
+                struct page *page = grab_meta_page(sbi, blkaddr);
+                /* zero-filled page */
+                set_page_dirty(page);
+                f2fs_put_page(page, 1);
+        }
 }
 
 static void add_discard_addrs(struct f2fs_sb_info *sbi,