[PATCH] f2fs: fix deadlock between quota writes and checkpoint

[Jaegeuk Kim]

f2fs_write_data_pages(quota_mapping)
 __f2fs_write_data_pages             f2fs_write_checkpoint
  * blk_start_plug(&plug);
  * add bio in write_io[DATA]
                                      - block_operations
                                      - skip syncing quota by
                                                >DEFAULT_RETRY_QUOTA_FLUSH_COUNT
                                      - down_write(&sbi->node_write);
  - f2fs_write_single_data_page
    - f2fs_do_write_data_page
      - f2fs_outplace_write_data
        - do_write_page
           - f2fs_allocate_data_block
            - down_write(node_write)
                                      - f2fs_wait_on_all_pages(F2FS_WB_CP_DATA);

Signed-off-by: Daeho Jeong <daehojeong@xxxxxxxxxx>
Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
---
 fs/f2fs/checkpoint.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index 8c782d3f324f0..99c8061da55b9 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -1269,6 +1269,8 @@ void f2fs_wait_on_all_pages(struct f2fs_sb_info *sbi, int type)
 		if (type == F2FS_DIRTY_META)
 			f2fs_sync_meta_pages(sbi, META, LONG_MAX,
 							FS_CP_META_IO);
+		else if (type == F2FS_WB_CP_DATA)
+			f2fs_submit_merged_write(sbi, DATA);
 		io_schedule_timeout(DEFAULT_IO_TIMEOUT);
 	}
 	finish_wait(&sbi->cp_wait, &wait);
-- 
2.28.0.rc0.142.g3c755180ce-goog