@@ -237,21 +237,6 @@ int coroutine_fn bdrv_co_copy_range(BdrvChild *src, int64_t src_offset,
int64_t bytes, BdrvRequestFlags read_flags,
BdrvRequestFlags write_flags);
-/**
- * bdrv_drained_end_no_poll:
- *
- * Same as bdrv_drained_end(), but do not poll for the subgraph to
- * actually become unquiesced. Therefore, no graph changes will occur
- * with this function.
- *
- * *drained_end_counter is incremented for every background operation
- * that is scheduled, and will be decremented for every operation once
- * it settles. The caller must poll until it reaches 0. The counter
- * should be accessed using atomic operations only.
- */
-void bdrv_drained_end_no_poll(BlockDriverState *bs, int *drained_end_counter);
-
-
/*
* "I/O or GS" API functions. These functions can run without
* the BQL, but only in one specific iothread/main loop.
@@ -311,9 +296,6 @@ void bdrv_parent_drained_begin_single(BdrvChild *c, bool poll);
* bdrv_parent_drained_end_single:
*
* End a quiesced section for the parent of @c.
- *
- * This polls @bs's AioContext until all scheduled sub-drained_ends
- * have settled, which may result in graph changes.
*/
void bdrv_parent_drained_end_single(BdrvChild *c);
@@ -361,12 +343,6 @@ void bdrv_subtree_drained_begin(BlockDriverState *bs);
* bdrv_drained_end:
*
* End a quiescent section started by bdrv_drained_begin().
- *
- * This polls @bs's AioContext until all scheduled sub-drained_ends
- * have settled. On one hand, that may result in graph changes. On
- * the other, this requires that the caller either runs in the main
- * loop; or that all involved nodes (@bs and all of its parents) are
- * in the caller's AioContext.
*/
void bdrv_drained_end(BlockDriverState *bs);
@@ -939,15 +939,11 @@ struct BdrvChildClass {
* These functions must not change the graph (and therefore also must not
* call aio_poll(), which could change the graph indirectly).
*
- * If drained_end() schedules background operations, it must atomically
- * increment *drained_end_counter for each such operation and atomically
- * decrement it once the operation has settled.
- *
* Note that this can be nested. If drained_begin() was called twice, new
* I/O is allowed only after drained_end() was called twice, too.
*/
void (*drained_begin)(BdrvChild *child);
- void (*drained_end)(BdrvChild *child, int *drained_end_counter);
+ void (*drained_end)(BdrvChild *child);
/*
* Returns whether the parent has pending requests for the child. This
@@ -1235,11 +1235,10 @@ static bool bdrv_child_cb_drained_poll(BdrvChild *child)
return bdrv_drain_poll(bs, false, NULL, false);
}
-static void bdrv_child_cb_drained_end(BdrvChild *child,
- int *drained_end_counter)
+static void bdrv_child_cb_drained_end(BdrvChild *child)
{
BlockDriverState *bs = child->opaque;
- bdrv_drained_end_no_poll(bs, drained_end_counter);
+ bdrv_drained_end(bs);
}
static int bdrv_child_cb_inactivate(BdrvChild *child)
@@ -129,7 +129,7 @@ static void blk_root_inherit_options(BdrvChildRole role, bool parent_is_format,
}
static void blk_root_drained_begin(BdrvChild *child);
static bool blk_root_drained_poll(BdrvChild *child);
-static void blk_root_drained_end(BdrvChild *child, int *drained_end_counter);
+static void blk_root_drained_end(BdrvChild *child);
static void blk_root_change_media(BdrvChild *child, bool load);
static void blk_root_resize(BdrvChild *child);
@@ -2556,7 +2556,7 @@ static bool blk_root_drained_poll(BdrvChild *child)
return busy || !!blk->in_flight;
}
-static void blk_root_drained_end(BdrvChild *child, int *drained_end_counter)
+static void blk_root_drained_end(BdrvChild *child)
{
BlockBackend *blk = child->opaque;
assert(blk->quiesce_counter);
@@ -58,28 +58,19 @@ static void bdrv_parent_drained_begin(BlockDriverState *bs, BdrvChild *ignore,
}
}
-static void bdrv_parent_drained_end_single_no_poll(BdrvChild *c,
- int *drained_end_counter)
+void bdrv_parent_drained_end_single(BdrvChild *c)
{
+ IO_OR_GS_CODE();
+
assert(c->parent_quiesce_counter > 0);
c->parent_quiesce_counter--;
if (c->klass->drained_end) {
- c->klass->drained_end(c, drained_end_counter);
+ c->klass->drained_end(c);
}
}
-void bdrv_parent_drained_end_single(BdrvChild *c)
-{
- int drained_end_counter = 0;
- AioContext *ctx = bdrv_child_get_parent_aio_context(c);
- IO_OR_GS_CODE();
- bdrv_parent_drained_end_single_no_poll(c, &drained_end_counter);
- AIO_WAIT_WHILE(ctx, qatomic_read(&drained_end_counter) > 0);
-}
-
static void bdrv_parent_drained_end(BlockDriverState *bs, BdrvChild *ignore,
- bool ignore_bds_parents,
- int *drained_end_counter)
+ bool ignore_bds_parents)
{
BdrvChild *c;
@@ -87,7 +78,7 @@ static void bdrv_parent_drained_end(BlockDriverState *bs, BdrvChild *ignore,
if (c == ignore || (ignore_bds_parents && c->klass->parent_is_bds)) {
continue;
}
- bdrv_parent_drained_end_single_no_poll(c, drained_end_counter);
+ bdrv_parent_drained_end_single(c);
}
}
@@ -249,12 +240,10 @@ typedef struct {
bool poll;
BdrvChild *parent;
bool ignore_bds_parents;
- int *drained_end_counter;
} BdrvCoDrainData;
/* Recursively call BlockDriver.bdrv_drain_begin/end callbacks */
-static void bdrv_drain_invoke(BlockDriverState *bs, bool begin,
- int *drained_end_counter)
+static void bdrv_drain_invoke(BlockDriverState *bs, bool begin)
{
if (!bs->drv || (begin && !bs->drv->bdrv_drain_begin) ||
(!begin && !bs->drv->bdrv_drain_end)) {
@@ -305,8 +294,7 @@ static void bdrv_do_drained_begin(BlockDriverState *bs, bool recursive,
BdrvChild *parent, bool ignore_bds_parents,
bool poll);
static void bdrv_do_drained_end(BlockDriverState *bs, bool recursive,
- BdrvChild *parent, bool ignore_bds_parents,
- int *drained_end_counter);
+ BdrvChild *parent, bool ignore_bds_parents);
static void bdrv_co_drain_bh_cb(void *opaque)
{
@@ -319,14 +307,12 @@ static void bdrv_co_drain_bh_cb(void *opaque)
aio_context_acquire(ctx);
bdrv_dec_in_flight(bs);
if (data->begin) {
- assert(!data->drained_end_counter);
bdrv_do_drained_begin(bs, data->recursive, data->parent,
data->ignore_bds_parents, data->poll);
} else {
assert(!data->poll);
bdrv_do_drained_end(bs, data->recursive, data->parent,
- data->ignore_bds_parents,
- data->drained_end_counter);
+ data->ignore_bds_parents);
}
aio_context_release(ctx);
} else {
@@ -342,8 +328,7 @@ static void coroutine_fn bdrv_co_yield_to_drain(BlockDriverState *bs,
bool begin, bool recursive,
BdrvChild *parent,
bool ignore_bds_parents,
- bool poll,
- int *drained_end_counter)
+ bool poll)
{
BdrvCoDrainData data;
Coroutine *self = qemu_coroutine_self();
@@ -363,7 +348,6 @@ static void coroutine_fn bdrv_co_yield_to_drain(BlockDriverState *bs,
.parent = parent,
.ignore_bds_parents = ignore_bds_parents,
.poll = poll,
- .drained_end_counter = drained_end_counter,
};
if (bs) {
@@ -406,7 +390,7 @@ void bdrv_do_drained_begin_quiesce(BlockDriverState *bs,
}
bdrv_parent_drained_begin(bs, parent, ignore_bds_parents);
- bdrv_drain_invoke(bs, true, NULL);
+ bdrv_drain_invoke(bs, true);
}
static void bdrv_do_drained_begin(BlockDriverState *bs, bool recursive,
@@ -417,7 +401,7 @@ static void bdrv_do_drained_begin(BlockDriverState *bs, bool recursive,
if (qemu_in_coroutine()) {
bdrv_co_yield_to_drain(bs, true, recursive, parent, ignore_bds_parents,
- poll, NULL);
+ poll);
return;
}
@@ -461,38 +445,24 @@ void bdrv_subtree_drained_begin(BlockDriverState *bs)
/**
* This function does not poll, nor must any of its recursively called
- * functions. The *drained_end_counter pointee will be incremented
- * once for every background operation scheduled, and decremented once
- * the operation settles. Therefore, the pointer must remain valid
- * until the pointee reaches 0. That implies that whoever sets up the
- * pointee has to poll until it is 0.
- *
- * We use atomic operations to access *drained_end_counter, because
- * (1) when called from bdrv_set_aio_context_ignore(), the subgraph of
- * @bs may contain nodes in different AioContexts,
- * (2) bdrv_drain_all_end() uses the same counter for all nodes,
- * regardless of which AioContext they are in.
+ * functions.
*/
static void bdrv_do_drained_end(BlockDriverState *bs, bool recursive,
- BdrvChild *parent, bool ignore_bds_parents,
- int *drained_end_counter)
+ BdrvChild *parent, bool ignore_bds_parents)
{
BdrvChild *child;
int old_quiesce_counter;
- assert(drained_end_counter != NULL);
-
if (qemu_in_coroutine()) {
bdrv_co_yield_to_drain(bs, false, recursive, parent, ignore_bds_parents,
- false, drained_end_counter);
+ false);
return;
}
assert(bs->quiesce_counter > 0);
/* Re-enable things in child-to-parent order */
- bdrv_drain_invoke(bs, false, drained_end_counter);
- bdrv_parent_drained_end(bs, parent, ignore_bds_parents,
- drained_end_counter);
+ bdrv_drain_invoke(bs, false);
+ bdrv_parent_drained_end(bs, parent, ignore_bds_parents);
old_quiesce_counter = qatomic_fetch_dec(&bs->quiesce_counter);
if (old_quiesce_counter == 1) {
@@ -503,32 +473,21 @@ static void bdrv_do_drained_end(BlockDriverState *bs, bool recursive,
assert(!ignore_bds_parents);
bs->recursive_quiesce_counter--;
QLIST_FOREACH(child, &bs->children, next) {
- bdrv_do_drained_end(child->bs, true, child, ignore_bds_parents,
- drained_end_counter);
+ bdrv_do_drained_end(child->bs, true, child, ignore_bds_parents);
}
}
}
void bdrv_drained_end(BlockDriverState *bs)
{
- int drained_end_counter = 0;
IO_OR_GS_CODE();
- bdrv_do_drained_end(bs, false, NULL, false, &drained_end_counter);
- BDRV_POLL_WHILE(bs, qatomic_read(&drained_end_counter) > 0);
-}
-
-void bdrv_drained_end_no_poll(BlockDriverState *bs, int *drained_end_counter)
-{
- IO_CODE();
- bdrv_do_drained_end(bs, false, NULL, false, drained_end_counter);
+ bdrv_do_drained_end(bs, false, NULL, false);
}
void bdrv_subtree_drained_end(BlockDriverState *bs)
{
- int drained_end_counter = 0;
IO_OR_GS_CODE();
- bdrv_do_drained_end(bs, true, NULL, false, &drained_end_counter);
- BDRV_POLL_WHILE(bs, qatomic_read(&drained_end_counter) > 0);
+ bdrv_do_drained_end(bs, true, NULL, false);
}
void bdrv_apply_subtree_drain(BdrvChild *child, BlockDriverState *new_parent)
@@ -543,16 +502,12 @@ void bdrv_apply_subtree_drain(BdrvChild *child, BlockDriverState *new_parent)
void bdrv_unapply_subtree_drain(BdrvChild *child, BlockDriverState *old_parent)
{
- int drained_end_counter = 0;
int i;
IO_OR_GS_CODE();
for (i = 0; i < old_parent->recursive_quiesce_counter; i++) {
- bdrv_do_drained_end(child->bs, true, child, false,
- &drained_end_counter);
+ bdrv_do_drained_end(child->bs, true, child, false);
}
-
- BDRV_POLL_WHILE(child->bs, qatomic_read(&drained_end_counter) > 0);
}
void bdrv_drain(BlockDriverState *bs)
@@ -610,7 +565,7 @@ void bdrv_drain_all_begin(void)
GLOBAL_STATE_CODE();
if (qemu_in_coroutine()) {
- bdrv_co_yield_to_drain(NULL, true, false, NULL, true, true, NULL);
+ bdrv_co_yield_to_drain(NULL, true, false, NULL, true, true);
return;
}
@@ -649,22 +604,19 @@ void bdrv_drain_all_begin(void)
void bdrv_drain_all_end_quiesce(BlockDriverState *bs)
{
- int drained_end_counter = 0;
GLOBAL_STATE_CODE();
g_assert(bs->quiesce_counter > 0);
g_assert(!bs->refcnt);
while (bs->quiesce_counter) {
- bdrv_do_drained_end(bs, false, NULL, true, &drained_end_counter);
+ bdrv_do_drained_end(bs, false, NULL, true);
}
- BDRV_POLL_WHILE(bs, qatomic_read(&drained_end_counter) > 0);
}
void bdrv_drain_all_end(void)
{
BlockDriverState *bs = NULL;
- int drained_end_counter = 0;
GLOBAL_STATE_CODE();
/*
@@ -680,13 +632,11 @@ void bdrv_drain_all_end(void)
AioContext *aio_context = bdrv_get_aio_context(bs);
aio_context_acquire(aio_context);
- bdrv_do_drained_end(bs, false, NULL, true, &drained_end_counter);
+ bdrv_do_drained_end(bs, false, NULL, true);
aio_context_release(aio_context);
}
assert(qemu_get_current_aio_context() == qemu_get_aio_context());
- AIO_WAIT_WHILE(NULL, qatomic_read(&drained_end_counter) > 0);
-
assert(bdrv_drain_all_count > 0);
bdrv_drain_all_count--;
}
@@ -120,7 +120,7 @@ static bool child_job_drained_poll(BdrvChild *c)
}
}
-static void child_job_drained_end(BdrvChild *c, int *drained_end_counter)
+static void child_job_drained_end(BdrvChild *c)
{
BlockJob *job = c->opaque;
job_resume(&job->job);