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[Qemu-devel] [PULL 01/11] block: get rid of bdrv_io_unplugged_begin/end
From: |
Stefan Hajnoczi |
Subject: |
[Qemu-devel] [PULL 01/11] block: get rid of bdrv_io_unplugged_begin/end |
Date: |
Mon, 16 Jan 2017 13:39:01 +0000 |
From: Paolo Bonzini <address@hidden>
bdrv_io_plug and bdrv_io_unplug are only called (via their
BlockBackend equivalents) after starting asynchronous I/O.
bdrv_drain is not going to be called while they are running,
because---even if a coroutine runs for some reason---it will
only drain in the next iteration of the event loop through
bdrv_co_yield_to_drain.
So this mechanism is unnecessary, get rid of it.
Signed-off-by: Paolo Bonzini <address@hidden>
Message-id: address@hidden
Signed-off-by: Stefan Hajnoczi <address@hidden>
---
include/block/block.h | 2 --
include/block/block_int.h | 3 +--
block/io.c | 41 ++---------------------------------------
3 files changed, 3 insertions(+), 43 deletions(-)
diff --git a/include/block/block.h b/include/block/block.h
index 49bb0b2..8b0dcda 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -526,8 +526,6 @@ int bdrv_probe_geometry(BlockDriverState *bs, HDGeometry
*geo);
void bdrv_io_plug(BlockDriverState *bs);
void bdrv_io_unplug(BlockDriverState *bs);
-void bdrv_io_unplugged_begin(BlockDriverState *bs);
-void bdrv_io_unplugged_end(BlockDriverState *bs);
/**
* bdrv_drained_begin:
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 4e4562d..2d92d7e 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -526,9 +526,8 @@ struct BlockDriverState {
uint64_t write_threshold_offset;
NotifierWithReturn write_threshold_notifier;
- /* counters for nested bdrv_io_plug and bdrv_io_unplugged_begin */
+ /* counter for nested bdrv_io_plug */
unsigned io_plugged;
- unsigned io_plug_disabled;
int quiesce_counter;
};
diff --git a/block/io.c b/block/io.c
index 4f00562..c42b34a 100644
--- a/block/io.c
+++ b/block/io.c
@@ -228,9 +228,7 @@ void bdrv_drained_begin(BlockDriverState *bs)
bdrv_parent_drained_begin(bs);
}
- bdrv_io_unplugged_begin(bs);
bdrv_drain_recurse(bs);
- bdrv_io_unplugged_end(bs);
}
void bdrv_drained_end(BlockDriverState *bs)
@@ -302,7 +300,6 @@ void bdrv_drain_all_begin(void)
aio_context_acquire(aio_context);
bdrv_parent_drained_begin(bs);
- bdrv_io_unplugged_begin(bs);
aio_disable_external(aio_context);
aio_context_release(aio_context);
@@ -347,7 +344,6 @@ void bdrv_drain_all_end(void)
aio_context_acquire(aio_context);
aio_enable_external(aio_context);
- bdrv_io_unplugged_end(bs);
bdrv_parent_drained_end(bs);
aio_context_release(aio_context);
}
@@ -2650,7 +2646,7 @@ void bdrv_io_plug(BlockDriverState *bs)
bdrv_io_plug(child->bs);
}
- if (bs->io_plugged++ == 0 && bs->io_plug_disabled == 0) {
+ if (bs->io_plugged++ == 0) {
BlockDriver *drv = bs->drv;
if (drv && drv->bdrv_io_plug) {
drv->bdrv_io_plug(bs);
@@ -2663,7 +2659,7 @@ void bdrv_io_unplug(BlockDriverState *bs)
BdrvChild *child;
assert(bs->io_plugged);
- if (--bs->io_plugged == 0 && bs->io_plug_disabled == 0) {
+ if (--bs->io_plugged == 0) {
BlockDriver *drv = bs->drv;
if (drv && drv->bdrv_io_unplug) {
drv->bdrv_io_unplug(bs);
@@ -2674,36 +2670,3 @@ void bdrv_io_unplug(BlockDriverState *bs)
bdrv_io_unplug(child->bs);
}
}
-
-void bdrv_io_unplugged_begin(BlockDriverState *bs)
-{
- BdrvChild *child;
-
- if (bs->io_plug_disabled++ == 0 && bs->io_plugged > 0) {
- BlockDriver *drv = bs->drv;
- if (drv && drv->bdrv_io_unplug) {
- drv->bdrv_io_unplug(bs);
- }
- }
-
- QLIST_FOREACH(child, &bs->children, next) {
- bdrv_io_unplugged_begin(child->bs);
- }
-}
-
-void bdrv_io_unplugged_end(BlockDriverState *bs)
-{
- BdrvChild *child;
-
- assert(bs->io_plug_disabled);
- QLIST_FOREACH(child, &bs->children, next) {
- bdrv_io_unplugged_end(child->bs);
- }
-
- if (--bs->io_plug_disabled == 0 && bs->io_plugged > 0) {
- BlockDriver *drv = bs->drv;
- if (drv && drv->bdrv_io_plug) {
- drv->bdrv_io_plug(bs);
- }
- }
-}
--
2.9.3
- [Qemu-devel] [PULL 00/11] Block patches, Stefan Hajnoczi, 2017/01/16
- [Qemu-devel] [PULL 01/11] block: get rid of bdrv_io_unplugged_begin/end,
Stefan Hajnoczi <=
- [Qemu-devel] [PULL 02/11] aio: rename bh_lock to list_lock, Stefan Hajnoczi, 2017/01/16
- [Qemu-devel] [PULL 03/11] qemu-thread: introduce QemuLockCnt, Stefan Hajnoczi, 2017/01/16
- [Qemu-devel] [PULL 04/11] aio: make ctx->list_lock a QemuLockCnt, subsuming ctx->walking_bh, Stefan Hajnoczi, 2017/01/16
- [Qemu-devel] [PULL 06/11] aio-posix: split aio_dispatch_handlers out of aio_dispatch, Stefan Hajnoczi, 2017/01/16
- [Qemu-devel] [PULL 05/11] qemu-thread: optimize QemuLockCnt with futexes on Linux, Stefan Hajnoczi, 2017/01/16
- [Qemu-devel] [PULL 07/11] aio: tweak walking in dispatch phase, Stefan Hajnoczi, 2017/01/16
- [Qemu-devel] [PULL 08/11] aio-posix: remove walking_handlers, protecting AioHandler list with list_lock, Stefan Hajnoczi, 2017/01/16
- [Qemu-devel] [PULL 09/11] aio-win32: remove walking_handlers, protecting AioHandler list with list_lock, Stefan Hajnoczi, 2017/01/16
- [Qemu-devel] [PULL 11/11] async: optimize aio_bh_poll, Stefan Hajnoczi, 2017/01/16
- [Qemu-devel] [PULL 10/11] aio: document locking, Stefan Hajnoczi, 2017/01/16