block: Move throttling fields from BDS to BB

This patch changes where the throttling state is stored (used to be the
BlockDriverState, now it is the BlockBackend), but it doesn't actually
make it a BB level feature yet. For example, throttling is still
disabled when the BDS is detached from the BB.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>

1 files changed, 25 insertions, 11 deletions

diff --git a/block/io.c b/block/io.c
index f6fb86883a..bdbaa1c0da 100644
--- a/block/io.c
+++ b/block/io.c
@@ -55,20 +55,31 @@ void bdrv_set_io_limits(BlockDriverState *bs,
 
 void bdrv_no_throttling_begin(BlockDriverState *bs)
 {
-    if (bs->io_limits_disabled++ == 0) {
-        throttle_group_restart_bs(bs);
+    if (!bs->blk) {
+        return;
+    }
+
+    if (blk_get_public(bs->blk)->io_limits_disabled++ == 0) {
+        throttle_group_restart_blk(bs->blk);
     }
 }
 
 void bdrv_no_throttling_end(BlockDriverState *bs)
 {
-    assert(bs->io_limits_disabled);
-    --bs->io_limits_disabled;
+    BlockBackendPublic *blkp;
+
+    if (!bs->blk) {
+        return;
+    }
+
+    blkp = blk_get_public(bs->blk);
+    assert(blkp->io_limits_disabled);
+    --blkp->io_limits_disabled;
 }
 
 void bdrv_io_limits_disable(BlockDriverState *bs)
 {
-    assert(bs->throttle_state);
+    assert(blk_get_public(bs->blk)->throttle_state);
     bdrv_no_throttling_begin(bs);
     throttle_group_unregister_blk(bs->blk);
     bdrv_no_throttling_end(bs);
@@ -77,14 +88,16 @@ void bdrv_io_limits_disable(BlockDriverState *bs)
 /* should be called before bdrv_set_io_limits if a limit is set */
 void bdrv_io_limits_enable(BlockDriverState *bs, const char *group)
 {
-    assert(!bs->throttle_state);
+    BlockBackendPublic *blkp = blk_get_public(bs->blk);
+
+    assert(!blkp->throttle_state);
     throttle_group_register_blk(bs->blk, group);
 }
 
 void bdrv_io_limits_update_group(BlockDriverState *bs, const char *group)
 {
     /* this bs is not part of any group */
-    if (!bs->throttle_state) {
+    if (!blk_get_public(bs->blk)->throttle_state) {
         return;
     }
 
@@ -178,14 +191,15 @@ void bdrv_disable_copy_on_read(BlockDriverState *bs)
 bool bdrv_requests_pending(BlockDriverState *bs)
 {
     BdrvChild *child;
+    BlockBackendPublic *blkp = bs->blk ? blk_get_public(bs->blk) : NULL;
 
     if (!QLIST_EMPTY(&bs->tracked_requests)) {
         return true;
     }
-    if (!qemu_co_queue_empty(&bs->throttled_reqs[0])) {
+    if (blkp && !qemu_co_queue_empty(&blkp->throttled_reqs[0])) {
         return true;
     }
-    if (!qemu_co_queue_empty(&bs->throttled_reqs[1])) {
+    if (blkp && !qemu_co_queue_empty(&blkp->throttled_reqs[1])) {
         return true;
     }
 
@@ -1070,7 +1084,7 @@ int coroutine_fn bdrv_co_preadv(BlockDriverState *bs,
     }
 
     /* throttling disk I/O */
-    if (bs->throttle_state) {
+    if (bs->blk && blk_get_public(bs->blk)->throttle_state) {
         throttle_group_co_io_limits_intercept(bs, bytes, false);
     }
 
@@ -1431,7 +1445,7 @@ int coroutine_fn bdrv_co_pwritev(BlockDriverState *bs,
     }
 
     /* throttling disk I/O */
-    if (bs->throttle_state) {
+    if (bs->blk && blk_get_public(bs->blk)->throttle_state) {
         throttle_group_co_io_limits_intercept(bs, bytes, true);
     }