[PATCH] f2fs: enlarge block plug coverage

[Chao Yu]

This patch enlarges block plug coverage in __issue_discard_cmd, in
order to collect more pending bios before issuing them, to avoid
being disturbed by previous discard I/O in IO aware discard mode.

Signed-off-by: Chao Yu <yuch...@huawei.com>
---
 fs/f2fs/segment.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 8f0b5ba46315..4287e208c040 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -1208,10 +1208,12 @@ static int __issue_discard_cmd(struct f2fs_sb_info *sbi,
                pend_list = &dcc->pend_list[i];
 
                mutex_lock(&dcc->cmd_lock);
+
+               blk_start_plug(&plug);
+
                if (list_empty(pend_list))
                        goto next;
                f2fs_bug_on(sbi, !__check_rb_tree_consistence(sbi, &dcc->root));
-               blk_start_plug(&plug);
                list_for_each_entry_safe(dc, tmp, pend_list, list) {
                        f2fs_bug_on(sbi, dc->state != D_PREP);
 
@@ -1227,8 +1229,9 @@ static int __issue_discard_cmd(struct f2fs_sb_info *sbi,
                        if (++iter >= dpolicy->max_requests)
                                break;
                }
-               blk_finish_plug(&plug);
 next:
+               blk_finish_plug(&plug);
+
                mutex_unlock(&dcc->cmd_lock);
 
                if (iter >= dpolicy->max_requests)
-- 
2.15.0.55.gc2ece9dc4de6