[dm-devel] [RFC PATCH 1/4] dm core: remove unused code

[Milan Broz]

This patch removes dead codes for the noflush suspend.
No functional change.

The dm_queue_flush(md, DM_WQ_FLUSH_ALL, NULL) in dm_suspend()
is never invoked because:
  - The 'goto flush_and_out' is same as 'goto out', because
    the 'goto flush_and_out' is called only when '!noflush'
  - If the 'r && noflush' is true, the interrupt check code above
    is invoked and 'goto out'

Signed-off-by: Kiyoshi Ueda <k-ueda at ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura at ce.jp.nec.com>
Signed-off-by: Milan Broz <mbroz at redhat.com>
---
 drivers/md/dm.c |   14 +-------------
 1 files changed, 1 insertions(+), 13 deletions(-)

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index bca448e..83b0c64 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -76,7 +76,6 @@ union map_info *dm_get_mapinfo(struct bio *bio)
  */
 struct dm_wq_req {
 	enum {
-		DM_WQ_FLUSH_ALL,
 		DM_WQ_FLUSH_DEFERRED,
 	} type;
 	struct work_struct work;
@@ -1384,9 +1383,6 @@ static void dm_wq_work(struct work_struct *work)
 
 	down_write(&md->io_lock);
 	switch (req->type) {
-	case DM_WQ_FLUSH_ALL:
-		__merge_pushback_list(md);
-		/* pass through */
 	case DM_WQ_FLUSH_DEFERRED:
 		__flush_deferred_io(md);
 		break;
@@ -1516,7 +1512,7 @@ int dm_suspend(struct mapped_device *md, unsigned suspend_flags)
 		if (!md->suspended_bdev) {
 			DMWARN("bdget failed in dm_suspend");
 			r = -ENOMEM;
-			goto flush_and_out;
+			goto out;
 		}
 
 		/*
@@ -1567,14 +1563,6 @@ int dm_suspend(struct mapped_device *md, unsigned suspend_flags)
 
 	set_bit(DMF_SUSPENDED, &md->flags);
 
-flush_and_out:
-	if (r && noflush)
-		/*
-		 * Because there may be already I/Os in the pushback list,
-		 * flush them before return.
-		 */
-		dm_queue_flush(md, DM_WQ_FLUSH_ALL, NULL);
-
 out:
 	if (r && md->suspended_bdev) {
 		bdput(md->suspended_bdev);