This removes the last part of I/O throttling from block/io.c and moves
it to the BlockBackend.
Instead of having knowledge about throttling inside io.c, we can call a
BdrvChild callback .drained_begin/end, which happens to drain the
throttled requests for BlockBackend parents.
Signed-off-by: Kevin Wolf <kw...@redhat.com>
---
block/block-backend.c | 32 +++++++++++++++++++++++++++-----
block/io.c | 39 ++++++++++++++++++---------------------
include/block/block_int.h | 8 +++-----
3 files changed, 48 insertions(+), 31 deletions(-)
diff --git a/block/block-backend.c b/block/block-backend.c
index b72a73d..73ff5e6 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -91,9 +91,14 @@ static void blk_root_inherit_options(int *child_flags, QDict
*child_options,
/* We're not supposed to call this function for root nodes */
abort();
}
+static void blk_root_drained_begin(BdrvChild *child);
+static void blk_root_drained_end(BdrvChild *child);
static const BdrvChildRole child_root = {
- .inherit_options = blk_root_inherit_options,
+ .inherit_options = blk_root_inherit_options,
+
+ .drained_begin = blk_root_drained_begin,
+ .drained_end = blk_root_drained_end,
};
/*
@@ -836,9 +841,9 @@ int blk_read_unthrottled(BlockBackend *blk, int64_t
sector_num, uint8_t *buf,
return ret;
}
- bdrv_no_throttling_begin(blk_bs(blk));
+ blk_root_drained_begin(blk->root);
ret = blk_read(blk, sector_num, buf, nb_sectors);
- bdrv_no_throttling_end(blk_bs(blk));
+ blk_root_drained_end(blk->root);
return ret;
}
@@ -1677,9 +1682,9 @@ void blk_set_io_limits(BlockBackend *blk, ThrottleConfig
*cfg)
void blk_io_limits_disable(BlockBackend *blk)
{
assert(blk->public.throttle_state);
- bdrv_no_throttling_begin(blk_bs(blk));
+ bdrv_drained_begin(blk_bs(blk));
throttle_group_unregister_blk(blk);
- bdrv_no_throttling_end(blk_bs(blk));
+ bdrv_drained_end(blk_bs(blk));
}
/* should be called before bdrv_set_io_limits if a limit is set */
@@ -1705,3 +1710,20 @@ void blk_io_limits_update_group(BlockBackend *blk, const
char *group)
blk_io_limits_disable(blk);
blk_io_limits_enable(blk, group);
}
+
+static void blk_root_drained_begin(BdrvChild *child)
+{
+ BlockBackend *blk = child->opaque;
+
+ if (blk->public.io_limits_disabled++ == 0) {
+ throttle_group_restart_blk(blk);
+ }
+}
+
+static void blk_root_drained_end(BdrvChild *child)
+{
+ BlockBackend *blk = child->opaque;
+
+ assert(blk->public.io_limits_disabled);
+ --blk->public.io_limits_disabled;
+}
diff --git a/block/io.c b/block/io.c
index b892fce..b239e97 100644
--- a/block/io.c
+++ b/block/io.c
@@ -27,7 +27,6 @@
#include "sysemu/block-backend.h"
#include "block/blockjob.h"
#include "block/block_int.h"
-#include "block/throttle-groups.h"
#include "qemu/cutils.h"
#include "qapi/error.h"
#include "qemu/error-report.h"
@@ -58,28 +57,26 @@ static void coroutine_fn bdrv_co_do_rw(void *opaque);
static int coroutine_fn bdrv_co_do_write_zeroes(BlockDriverState *bs,
int64_t sector_num, int nb_sectors, BdrvRequestFlags flags);
-void bdrv_no_throttling_begin(BlockDriverState *bs)
+static void bdrv_parent_drained_begin(BlockDriverState *bs)
{
- if (!bs->blk) {
- return;
- }
+ BdrvChild *c;
- if (blk_get_public(bs->blk)->io_limits_disabled++ == 0) {
- throttle_group_restart_blk(bs->blk);
+ QLIST_FOREACH(c, &bs->parents, next_parent) {
+ if (c->role->drained_begin) {
+ c->role->drained_begin(c);
+ }
}
}
-void bdrv_no_throttling_end(BlockDriverState *bs)
+static void bdrv_parent_drained_end(BlockDriverState *bs)
{
- BlockBackendPublic *blkp;
+ BdrvChild *c;
- if (!bs->blk) {
- return;
+ QLIST_FOREACH(c, &bs->parents, next_parent) {
+ if (c->role->drained_end) {
+ c->role->drained_end(c);
+ }
}
-
- blkp = blk_get_public(bs->blk);
- assert(blkp->io_limits_disabled);
- --blkp->io_limits_disabled;
}
void bdrv_setup_io_funcs(BlockDriver *bdrv)
@@ -278,17 +275,17 @@ static void coroutine_fn
bdrv_co_yield_to_drain(BlockDriverState *bs)
*/
void coroutine_fn bdrv_co_drain(BlockDriverState *bs)
{
- bdrv_no_throttling_begin(bs);
+ bdrv_parent_drained_begin(bs);
bdrv_io_unplugged_begin(bs);
bdrv_drain_recurse(bs);
bdrv_co_yield_to_drain(bs);
bdrv_io_unplugged_end(bs);
- bdrv_no_throttling_end(bs);
+ bdrv_parent_drained_end(bs);
}
void bdrv_drain(BlockDriverState *bs)
{
- bdrv_no_throttling_begin(bs);
+ bdrv_parent_drained_begin(bs);
bdrv_io_unplugged_begin(bs);
bdrv_drain_recurse(bs);
if (qemu_in_coroutine()) {
@@ -297,7 +294,7 @@ void bdrv_drain(BlockDriverState *bs)
bdrv_drain_poll(bs);
}
bdrv_io_unplugged_end(bs);
- bdrv_no_throttling_end(bs);
+ bdrv_parent_drained_end(bs);
}
/*
@@ -320,7 +317,7 @@ void bdrv_drain_all(void)
if (bs->job) {
block_job_pause(bs->job);
}
- bdrv_no_throttling_begin(bs);
+ bdrv_parent_drained_begin(bs);
bdrv_io_unplugged_begin(bs);
bdrv_drain_recurse(bs);
aio_context_release(aio_context);
@@ -363,7 +360,7 @@ void bdrv_drain_all(void)
aio_context_acquire(aio_context);
bdrv_io_unplugged_end(bs);
- bdrv_no_throttling_end(bs);
+ bdrv_parent_drained_end(bs);
if (bs->job) {
block_job_resume(bs->job);
}
diff --git a/include/block/block_int.h b/include/block/block_int.h
index ddadb7f..cfcdaec 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -361,6 +361,9 @@ typedef struct BdrvAioNotifier {
struct BdrvChildRole {
void (*inherit_options)(int *child_flags, QDict *child_options,
int parent_flags, QDict *parent_options);
+
+ void (*drained_begin)(BdrvChild *child);
+ void (*drained_end)(BdrvChild *child);
};
extern const BdrvChildRole child_file;
@@ -518,8 +521,6 @@ int get_tmp_filename(char *filename, int size);
BlockDriver *bdrv_probe_all(const uint8_t *buf, int buf_size,
const char *filename);
-bool bdrv_start_throttled_reqs(BlockDriverState *bs);
-
/**
* bdrv_add_before_write_notifier:
@@ -702,9 +703,6 @@ BdrvChild *bdrv_root_attach_child(BlockDriverState
*child_bs,
const BdrvChildRole *child_role);
void bdrv_root_unref_child(BdrvChild *child);
-void bdrv_no_throttling_begin(BlockDriverState *bs);
-void bdrv_no_throttling_end(BlockDriverState *bs);
-
void blk_dev_change_media_cb(BlockBackend *blk, bool load);
bool blk_dev_has_removable_media(BlockBackend *blk);
bool blk_dev_has_tray(BlockBackend *blk);
--
1.8.3.1
