From 09cf9db1bcd60d9889b774925ba7058286d35412 Mon Sep 17 00:00:00 2001
From: Kevin Wolf <kwolf@redhat.com>
Date: Fri, 18 Mar 2016 19:01:41 +0100
Subject: [PATCH] block: Remove bdrv_(set_)enable_write_cache()

The only remaining users were block jobs (mirror and backup) which
unconditionally enabled WCE on the BlockBackend of the target image. As
these block jobs don't go through BlockBackend for their I/O requests,
they aren't affected by this setting anyway but always get a writeback
mode, so that call can be removed.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
---
 block.c               | 16 ----------------
 block/backup.c        |  1 -
 block/mirror.c        |  1 -
 include/block/block.h |  2 --
 4 files changed, 20 deletions(-)

diff --git a/block.c b/block.c
index 7ff4fcb7f5..d36eb75be9 100644
--- a/block.c
+++ b/block.c
@@ -2695,22 +2695,6 @@ int bdrv_is_sg(BlockDriverState *bs)
     return bs->sg;
 }
 
-int bdrv_enable_write_cache(BlockDriverState *bs)
-{
-    if (bs->blk) {
-        return blk_enable_write_cache(bs->blk);
-    } else {
-        return true;
-    }
-}
-
-void bdrv_set_enable_write_cache(BlockDriverState *bs, bool wce)
-{
-    if (bs->blk) {
-        blk_set_enable_write_cache(bs->blk, wce);
-    }
-}
-
 int bdrv_is_encrypted(BlockDriverState *bs)
 {
     if (bs->backing && bs->backing->bs->encrypted) {
diff --git a/block/backup.c b/block/backup.c
index 9170983ba9..491fd14068 100644
--- a/block/backup.c
+++ b/block/backup.c
@@ -404,7 +404,6 @@ static void coroutine_fn backup_run(void *opaque)
 
     job->done_bitmap = bitmap_new(end);
 
-    bdrv_set_enable_write_cache(target, true);
     if (target->blk) {
         blk_set_on_error(target->blk, on_target_error, on_target_error);
         blk_iostatus_enable(target->blk);
diff --git a/block/mirror.c b/block/mirror.c
index 7bfd0d2996..f64db1a69b 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -856,7 +856,6 @@ static void mirror_start_job(BlockDriverState *bs, BlockDriverState *target,
 
     bdrv_op_block_all(s->target, s->common.blocker);
 
-    bdrv_set_enable_write_cache(s->target, true);
     if (s->target->blk) {
         blk_set_on_error(s->target->blk, on_target_error, on_target_error);
         blk_iostatus_enable(s->target->blk);
diff --git a/include/block/block.h b/include/block/block.h
index 7bacd556b8..6a39f946f5 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -395,8 +395,6 @@ int bdrv_is_allocated_above(BlockDriverState *top, BlockDriverState *base,
 
 int bdrv_is_read_only(BlockDriverState *bs);
 int bdrv_is_sg(BlockDriverState *bs);
-int bdrv_enable_write_cache(BlockDriverState *bs);
-void bdrv_set_enable_write_cache(BlockDriverState *bs, bool wce);
 bool bdrv_is_inserted(BlockDriverState *bs);
 int bdrv_media_changed(BlockDriverState *bs);
 void bdrv_lock_medium(BlockDriverState *bs, bool locked);