From: Kevin Wolf <kwolf@redhat.com>
To: qemu-block@nongnu.org
Cc: kwolf@redhat.com, peter.maydell@linaro.org, qemu-devel@nongnu.org
Subject: [Qemu-devel] [PULL 04/13] block: Add @drained_end_counter
Date: Fri, 19 Jul 2019 15:43:36 +0200 [thread overview]
Message-ID: <20190719134345.23526-5-kwolf@redhat.com> (raw)
In-Reply-To: <20190719134345.23526-1-kwolf@redhat.com>
From: Max Reitz <mreitz@redhat.com>
Callers can now pass a pointer to an integer that bdrv_drain_invoke()
(and its recursive callees) will increment for every
bdrv_drain_invoke_entry() operation they schedule.
bdrv_drain_invoke_entry() in turn will decrement it once it has invoked
BlockDriver.bdrv_co_drain_end().
We use atomic operations to access the pointee, because the
bdrv_do_drained_end() caller may wish to end drained sections for
multiple nodes in different AioContexts (bdrv_drain_all_end() does, for
example).
This is the first step to moving the polling for BdrvCoDrainData.done to
become true out of bdrv_drain_invoke() and into the root drained_end
function.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
block/io.c | 58 +++++++++++++++++++++++++++++++++++++-----------------
1 file changed, 40 insertions(+), 18 deletions(-)
diff --git a/block/io.c b/block/io.c
index 1e618f9a37..c42e18b068 100644
--- a/block/io.c
+++ b/block/io.c
@@ -194,6 +194,7 @@ typedef struct {
bool poll;
BdrvChild *parent;
bool ignore_bds_parents;
+ int *drained_end_counter;
} BdrvCoDrainData;
static void coroutine_fn bdrv_drain_invoke_entry(void *opaque)
@@ -211,13 +212,18 @@ static void coroutine_fn bdrv_drain_invoke_entry(void *opaque)
atomic_mb_set(&data->done, true);
bdrv_dec_in_flight(bs);
- if (data->begin) {
+ if (data->drained_end_counter) {
+ atomic_dec(data->drained_end_counter);
+ }
+
+ if (data->begin || data->drained_end_counter) {
g_free(data);
}
}
/* Recursively call BlockDriver.bdrv_co_drain_begin/end callbacks */
-static void bdrv_drain_invoke(BlockDriverState *bs, bool begin)
+static void bdrv_drain_invoke(BlockDriverState *bs, bool begin,
+ int *drained_end_counter)
{
BdrvCoDrainData *data;
@@ -230,16 +236,25 @@ static void bdrv_drain_invoke(BlockDriverState *bs, bool begin)
*data = (BdrvCoDrainData) {
.bs = bs,
.done = false,
- .begin = begin
+ .begin = begin,
+ .drained_end_counter = drained_end_counter,
};
+ if (!begin && drained_end_counter) {
+ atomic_inc(drained_end_counter);
+ }
+
/* Make sure the driver callback completes during the polling phase for
* drain_begin. */
bdrv_inc_in_flight(bs);
data->co = qemu_coroutine_create(bdrv_drain_invoke_entry, data);
aio_co_schedule(bdrv_get_aio_context(bs), data->co);
- if (!begin) {
+ /*
+ * TODO: Drop this and make callers pass @drained_end_counter and poll
+ * themselves
+ */
+ if (!begin && !drained_end_counter) {
BDRV_POLL_WHILE(bs, !data->done);
g_free(data);
}
@@ -281,7 +296,8 @@ 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);
+ BdrvChild *parent, bool ignore_bds_parents,
+ int *drained_end_counter);
static void bdrv_co_drain_bh_cb(void *opaque)
{
@@ -308,7 +324,8 @@ static void bdrv_co_drain_bh_cb(void *opaque)
data->ignore_bds_parents, data->poll);
} else {
bdrv_do_drained_end(bs, data->recursive, data->parent,
- data->ignore_bds_parents);
+ data->ignore_bds_parents,
+ data->drained_end_counter);
}
if (ctx == co_ctx) {
aio_context_release(ctx);
@@ -326,7 +343,8 @@ static void coroutine_fn bdrv_co_yield_to_drain(BlockDriverState *bs,
bool begin, bool recursive,
BdrvChild *parent,
bool ignore_bds_parents,
- bool poll)
+ bool poll,
+ int *drained_end_counter)
{
BdrvCoDrainData data;
@@ -343,7 +361,9 @@ 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) {
bdrv_inc_in_flight(bs);
}
@@ -367,7 +387,7 @@ void bdrv_do_drained_begin_quiesce(BlockDriverState *bs,
}
bdrv_parent_drained_begin(bs, parent, ignore_bds_parents);
- bdrv_drain_invoke(bs, true);
+ bdrv_drain_invoke(bs, true, NULL);
}
static void bdrv_do_drained_begin(BlockDriverState *bs, bool recursive,
@@ -378,7 +398,7 @@ 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);
+ poll, NULL);
return;
}
@@ -419,20 +439,21 @@ void bdrv_subtree_drained_begin(BlockDriverState *bs)
}
static void bdrv_do_drained_end(BlockDriverState *bs, bool recursive,
- BdrvChild *parent, bool ignore_bds_parents)
+ BdrvChild *parent, bool ignore_bds_parents,
+ int *drained_end_counter)
{
BdrvChild *child, *next;
int old_quiesce_counter;
if (qemu_in_coroutine()) {
bdrv_co_yield_to_drain(bs, false, recursive, parent, ignore_bds_parents,
- false);
+ false, drained_end_counter);
return;
}
assert(bs->quiesce_counter > 0);
/* Re-enable things in child-to-parent order */
- bdrv_drain_invoke(bs, false);
+ bdrv_drain_invoke(bs, false, drained_end_counter);
bdrv_parent_drained_end(bs, parent, ignore_bds_parents);
old_quiesce_counter = atomic_fetch_dec(&bs->quiesce_counter);
@@ -444,19 +465,20 @@ static void bdrv_do_drained_end(BlockDriverState *bs, bool recursive,
assert(!ignore_bds_parents);
bs->recursive_quiesce_counter--;
QLIST_FOREACH_SAFE(child, &bs->children, next, next) {
- bdrv_do_drained_end(child->bs, true, child, ignore_bds_parents);
+ bdrv_do_drained_end(child->bs, true, child, ignore_bds_parents,
+ drained_end_counter);
}
}
}
void bdrv_drained_end(BlockDriverState *bs)
{
- bdrv_do_drained_end(bs, false, NULL, false);
+ bdrv_do_drained_end(bs, false, NULL, false, NULL);
}
void bdrv_subtree_drained_end(BlockDriverState *bs)
{
- bdrv_do_drained_end(bs, true, NULL, false);
+ bdrv_do_drained_end(bs, true, NULL, false, NULL);
}
void bdrv_apply_subtree_drain(BdrvChild *child, BlockDriverState *new_parent)
@@ -473,7 +495,7 @@ void bdrv_unapply_subtree_drain(BdrvChild *child, BlockDriverState *old_parent)
int i;
for (i = 0; i < old_parent->recursive_quiesce_counter; i++) {
- bdrv_do_drained_end(child->bs, true, child, false);
+ bdrv_do_drained_end(child->bs, true, child, false, NULL);
}
}
@@ -543,7 +565,7 @@ void bdrv_drain_all_begin(void)
BlockDriverState *bs = NULL;
if (qemu_in_coroutine()) {
- bdrv_co_yield_to_drain(NULL, true, false, NULL, true, true);
+ bdrv_co_yield_to_drain(NULL, true, false, NULL, true, true, NULL);
return;
}
@@ -579,7 +601,7 @@ 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);
+ bdrv_do_drained_end(bs, false, NULL, true, NULL);
aio_context_release(aio_context);
}
--
2.20.1
next prev parent reply other threads:[~2019-07-19 13:45 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-19 13:43 [Qemu-devel] [PULL 00/13] Block layer patches Kevin Wolf
2019-07-19 13:43 ` [Qemu-devel] [PULL 01/13] iotests: Set read-zeroes on in null block driver for Valgrind Kevin Wolf
2019-07-24 7:18 ` Christian Borntraeger
2019-07-24 7:30 ` Andrey Shinkevich
2019-07-24 7:33 ` Christian Borntraeger
2019-07-24 7:37 ` Andrey Shinkevich
2019-07-24 7:38 ` Kevin Wolf
2019-07-24 7:57 ` Andrey Shinkevich
2019-07-24 8:05 ` Kevin Wolf
2019-07-24 8:23 ` Andrey Shinkevich
2019-07-19 13:43 ` [Qemu-devel] [PULL 02/13] block: Introduce BdrvChild.parent_quiesce_counter Kevin Wolf
2019-07-19 13:43 ` [Qemu-devel] [PULL 03/13] tests: Add job commit by drained_end test Kevin Wolf
2019-07-19 13:43 ` Kevin Wolf [this message]
2019-07-19 13:43 ` [Qemu-devel] [PULL 05/13] block: Make bdrv_parent_drained_[^_]*() static Kevin Wolf
2019-07-19 13:43 ` [Qemu-devel] [PULL 06/13] tests: Lock AioContexts in test-block-iothread Kevin Wolf
2019-07-19 13:43 ` [Qemu-devel] [PULL 07/13] block: Do not poll in bdrv_do_drained_end() Kevin Wolf
2019-07-19 13:43 ` [Qemu-devel] [PULL 08/13] tests: Extend commit by drained_end test Kevin Wolf
2019-07-19 13:43 ` [Qemu-devel] [PULL 09/13] block: Loop unsafely in bdrv*drained_end() Kevin Wolf
2019-07-19 13:43 ` [Qemu-devel] [PULL 10/13] iotests: Add @has_quit to vm.shutdown() Kevin Wolf
2019-07-19 13:43 ` [Qemu-devel] [PULL 11/13] iotests: Test commit with a filter on the chain Kevin Wolf
2019-07-19 13:43 ` [Qemu-devel] [PULL 12/13] vl: Drain before (block) job cancel when quitting Kevin Wolf
2019-07-19 13:43 ` [Qemu-devel] [PULL 13/13] iotests: Test quitting with job on throttled node Kevin Wolf
2019-07-22 9:11 ` [Qemu-devel] [PULL 00/13] Block layer patches Peter Maydell
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