[PATCH 3/4] f2fs: wait for discard completion after submission

[Jaegeuk Kim]

We don't need to wait for each discard commands when unmounting the image.

Signed-off-by: Jaegeuk Kim <jaeg...@kernel.org>
---
 fs/f2fs/segment.c | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 567019940e9b..d76e49c3d1b4 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -676,8 +676,12 @@ void f2fs_wait_discard_bio(struct f2fs_sb_info *sbi, 
block_t blkaddr)
        struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
        struct list_head *wait_list = &(dcc->discard_cmd_list);
        struct discard_cmd *dc, *tmp;
+       struct blk_plug plug;
 
        mutex_lock(&dcc->cmd_lock);
+
+       blk_start_plug(&plug);
+
        list_for_each_entry_safe(dc, tmp, wait_list, list) {
 
                if (blkaddr == NULL_ADDR) {
@@ -686,9 +690,6 @@ void f2fs_wait_discard_bio(struct f2fs_sb_info *sbi, 
block_t blkaddr)
                                submit_bio(dc->bio);
                                atomic_inc(&dcc->submit_discard);
                        }
-                       wait_for_completion_io(&dc->wait);
-
-                       __remove_discard_cmd(sbi, dc);
                        continue;
                }
 
@@ -699,6 +700,15 @@ void f2fs_wait_discard_bio(struct f2fs_sb_info *sbi, 
block_t blkaddr)
                                __remove_discard_cmd(sbi, dc);
                }
        }
+       blk_finish_plug(&plug);
+
+       /* this comes from f2fs_put_super */
+       if (blkaddr == NULL_ADDR) {
+               list_for_each_entry_safe(dc, tmp, wait_list, list) {
+                       wait_for_completion_io(&dc->wait);
+                       __remove_discard_cmd(sbi, dc);
+               }
+       }
        mutex_unlock(&dcc->cmd_lock);
 }
 
-- 
2.11.0