* [Qemu-devel] [PULL 1/3] block: add bdrv_co_drain_end callback
2017-10-13 13:49 [Qemu-devel] [PULL 0/3] Block patches Stefan Hajnoczi
@ 2017-10-13 13:49 ` Stefan Hajnoczi
2017-10-13 13:49 ` [Qemu-devel] [PULL 2/3] block: rename bdrv_co_drain to bdrv_co_drain_begin Stefan Hajnoczi
` (2 subsequent siblings)
3 siblings, 0 replies; 5+ messages in thread
From: Stefan Hajnoczi @ 2017-10-13 13:49 UTC (permalink / raw)
To: qemu-devel; +Cc: Peter Maydell, Manos Pitsidianakis, Stefan Hajnoczi
From: Manos Pitsidianakis <el13635@mail.ntua.gr>
BlockDriverState has a bdrv_co_drain() callback but no equivalent for
the end of the drain. The throttle driver (block/throttle.c) needs a way
to mark the end of the drain in order to toggle io_limits_disabled
correctly, thus bdrv_co_drain_end is needed.
Signed-off-by: Manos Pitsidianakis <el13635@mail.ntua.gr>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
include/block/block_int.h | 11 +++++++++--
block/io.c | 48 +++++++++++++++++++++++++++++++++--------------
2 files changed, 43 insertions(+), 16 deletions(-)
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 7e8a206239..dd62f4d083 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -354,10 +354,17 @@ struct BlockDriver {
int (*bdrv_probe_geometry)(BlockDriverState *bs, HDGeometry *geo);
/**
- * Drain and stop any internal sources of requests in the driver, and
- * remain so until next I/O callback (e.g. bdrv_co_writev) is called.
+ * bdrv_co_drain is called if implemented in the beginning of a
+ * drain operation to drain and stop any internal sources of requests in
+ * the driver.
+ * bdrv_co_drain_end is called if implemented at the end of the drain.
+ *
+ * They should be used by the driver to e.g. manage scheduled I/O
+ * requests, or toggle an internal state. After the end of the drain new
+ * requests will continue normally.
*/
void coroutine_fn (*bdrv_co_drain)(BlockDriverState *bs);
+ void coroutine_fn (*bdrv_co_drain_end)(BlockDriverState *bs);
void (*bdrv_add_child)(BlockDriverState *parent, BlockDriverState *child,
Error **errp);
diff --git a/block/io.c b/block/io.c
index 8e419070b5..342fb571cf 100644
--- a/block/io.c
+++ b/block/io.c
@@ -156,6 +156,7 @@ typedef struct {
Coroutine *co;
BlockDriverState *bs;
bool done;
+ bool begin;
} BdrvCoDrainData;
static void coroutine_fn bdrv_drain_invoke_entry(void *opaque)
@@ -163,18 +164,23 @@ static void coroutine_fn bdrv_drain_invoke_entry(void *opaque)
BdrvCoDrainData *data = opaque;
BlockDriverState *bs = data->bs;
- bs->drv->bdrv_co_drain(bs);
+ if (data->begin) {
+ bs->drv->bdrv_co_drain(bs);
+ } else {
+ bs->drv->bdrv_co_drain_end(bs);
+ }
/* Set data->done before reading bs->wakeup. */
atomic_mb_set(&data->done, true);
bdrv_wakeup(bs);
}
-static void bdrv_drain_invoke(BlockDriverState *bs)
+static void bdrv_drain_invoke(BlockDriverState *bs, bool begin)
{
- BdrvCoDrainData data = { .bs = bs, .done = false };
+ BdrvCoDrainData data = { .bs = bs, .done = false, .begin = begin};
- if (!bs->drv || !bs->drv->bdrv_co_drain) {
+ if (!bs->drv || (begin && !bs->drv->bdrv_co_drain) ||
+ (!begin && !bs->drv->bdrv_co_drain_end)) {
return;
}
@@ -183,15 +189,16 @@ static void bdrv_drain_invoke(BlockDriverState *bs)
BDRV_POLL_WHILE(bs, !data.done);
}
-static bool bdrv_drain_recurse(BlockDriverState *bs)
+static bool bdrv_drain_recurse(BlockDriverState *bs, bool begin)
{
BdrvChild *child, *tmp;
bool waited;
- waited = BDRV_POLL_WHILE(bs, atomic_read(&bs->in_flight) > 0);
-
/* Ensure any pending metadata writes are submitted to bs->file. */
- bdrv_drain_invoke(bs);
+ bdrv_drain_invoke(bs, begin);
+
+ /* Wait for drained requests to finish */
+ waited = BDRV_POLL_WHILE(bs, atomic_read(&bs->in_flight) > 0);
QLIST_FOREACH_SAFE(child, &bs->children, next, tmp) {
BlockDriverState *bs = child->bs;
@@ -208,7 +215,7 @@ static bool bdrv_drain_recurse(BlockDriverState *bs)
*/
bdrv_ref(bs);
}
- waited |= bdrv_drain_recurse(bs);
+ waited |= bdrv_drain_recurse(bs, begin);
if (in_main_loop) {
bdrv_unref(bs);
}
@@ -224,12 +231,18 @@ static void bdrv_co_drain_bh_cb(void *opaque)
BlockDriverState *bs = data->bs;
bdrv_dec_in_flight(bs);
- bdrv_drained_begin(bs);
+ if (data->begin) {
+ bdrv_drained_begin(bs);
+ } else {
+ bdrv_drained_end(bs);
+ }
+
data->done = true;
aio_co_wake(co);
}
-static void coroutine_fn bdrv_co_yield_to_drain(BlockDriverState *bs)
+static void coroutine_fn bdrv_co_yield_to_drain(BlockDriverState *bs,
+ bool begin)
{
BdrvCoDrainData data;
@@ -242,6 +255,7 @@ static void coroutine_fn bdrv_co_yield_to_drain(BlockDriverState *bs)
.co = qemu_coroutine_self(),
.bs = bs,
.done = false,
+ .begin = begin,
};
bdrv_inc_in_flight(bs);
aio_bh_schedule_oneshot(bdrv_get_aio_context(bs),
@@ -256,7 +270,7 @@ static void coroutine_fn bdrv_co_yield_to_drain(BlockDriverState *bs)
void bdrv_drained_begin(BlockDriverState *bs)
{
if (qemu_in_coroutine()) {
- bdrv_co_yield_to_drain(bs);
+ bdrv_co_yield_to_drain(bs, true);
return;
}
@@ -265,17 +279,22 @@ void bdrv_drained_begin(BlockDriverState *bs)
bdrv_parent_drained_begin(bs);
}
- bdrv_drain_recurse(bs);
+ bdrv_drain_recurse(bs, true);
}
void bdrv_drained_end(BlockDriverState *bs)
{
+ if (qemu_in_coroutine()) {
+ bdrv_co_yield_to_drain(bs, false);
+ return;
+ }
assert(bs->quiesce_counter > 0);
if (atomic_fetch_dec(&bs->quiesce_counter) > 1) {
return;
}
bdrv_parent_drained_end(bs);
+ bdrv_drain_recurse(bs, false);
aio_enable_external(bdrv_get_aio_context(bs));
}
@@ -353,7 +372,7 @@ void bdrv_drain_all_begin(void)
aio_context_acquire(aio_context);
for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
if (aio_context == bdrv_get_aio_context(bs)) {
- waited |= bdrv_drain_recurse(bs);
+ waited |= bdrv_drain_recurse(bs, true);
}
}
aio_context_release(aio_context);
@@ -374,6 +393,7 @@ void bdrv_drain_all_end(void)
aio_context_acquire(aio_context);
aio_enable_external(aio_context);
bdrv_parent_drained_end(bs);
+ bdrv_drain_recurse(bs, false);
aio_context_release(aio_context);
}
--
2.13.6
^ permalink raw reply related [flat|nested] 5+ messages in thread* [Qemu-devel] [PULL 2/3] block: rename bdrv_co_drain to bdrv_co_drain_begin
2017-10-13 13:49 [Qemu-devel] [PULL 0/3] Block patches Stefan Hajnoczi
2017-10-13 13:49 ` [Qemu-devel] [PULL 1/3] block: add bdrv_co_drain_end callback Stefan Hajnoczi
@ 2017-10-13 13:49 ` Stefan Hajnoczi
2017-10-13 13:49 ` [Qemu-devel] [PULL 3/3] block/throttle.c: add bdrv_co_drain_begin/end callbacks Stefan Hajnoczi
2017-10-16 14:54 ` [Qemu-devel] [PULL 0/3] Block patches Peter Maydell
3 siblings, 0 replies; 5+ messages in thread
From: Stefan Hajnoczi @ 2017-10-13 13:49 UTC (permalink / raw)
To: qemu-devel; +Cc: Peter Maydell, Manos Pitsidianakis, Stefan Hajnoczi
From: Manos Pitsidianakis <el13635@mail.ntua.gr>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Manos Pitsidianakis <el13635@mail.ntua.gr>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
include/block/block_int.h | 4 ++--
block/io.c | 4 ++--
block/qed.c | 6 +++---
3 files changed, 7 insertions(+), 7 deletions(-)
diff --git a/include/block/block_int.h b/include/block/block_int.h
index dd62f4d083..885c08e989 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -354,7 +354,7 @@ struct BlockDriver {
int (*bdrv_probe_geometry)(BlockDriverState *bs, HDGeometry *geo);
/**
- * bdrv_co_drain is called if implemented in the beginning of a
+ * bdrv_co_drain_begin is called if implemented in the beginning of a
* drain operation to drain and stop any internal sources of requests in
* the driver.
* bdrv_co_drain_end is called if implemented at the end of the drain.
@@ -363,7 +363,7 @@ struct BlockDriver {
* requests, or toggle an internal state. After the end of the drain new
* requests will continue normally.
*/
- void coroutine_fn (*bdrv_co_drain)(BlockDriverState *bs);
+ void coroutine_fn (*bdrv_co_drain_begin)(BlockDriverState *bs);
void coroutine_fn (*bdrv_co_drain_end)(BlockDriverState *bs);
void (*bdrv_add_child)(BlockDriverState *parent, BlockDriverState *child,
diff --git a/block/io.c b/block/io.c
index 342fb571cf..0854e0fdac 100644
--- a/block/io.c
+++ b/block/io.c
@@ -165,7 +165,7 @@ static void coroutine_fn bdrv_drain_invoke_entry(void *opaque)
BlockDriverState *bs = data->bs;
if (data->begin) {
- bs->drv->bdrv_co_drain(bs);
+ bs->drv->bdrv_co_drain_begin(bs);
} else {
bs->drv->bdrv_co_drain_end(bs);
}
@@ -179,7 +179,7 @@ static void bdrv_drain_invoke(BlockDriverState *bs, bool begin)
{
BdrvCoDrainData data = { .bs = bs, .done = false, .begin = begin};
- if (!bs->drv || (begin && !bs->drv->bdrv_co_drain) ||
+ if (!bs->drv || (begin && !bs->drv->bdrv_co_drain_begin) ||
(!begin && !bs->drv->bdrv_co_drain_end)) {
return;
}
diff --git a/block/qed.c b/block/qed.c
index 28e2ec89e8..821dcaa055 100644
--- a/block/qed.c
+++ b/block/qed.c
@@ -265,7 +265,7 @@ static bool qed_plug_allocating_write_reqs(BDRVQEDState *s)
assert(!s->allocating_write_reqs_plugged);
if (s->allocating_acb != NULL) {
/* Another allocating write came concurrently. This cannot happen
- * from bdrv_qed_co_drain, but it can happen when the timer runs.
+ * from bdrv_qed_co_drain_begin, but it can happen when the timer runs.
*/
qemu_co_mutex_unlock(&s->table_lock);
return false;
@@ -358,7 +358,7 @@ static void bdrv_qed_attach_aio_context(BlockDriverState *bs,
}
}
-static void coroutine_fn bdrv_qed_co_drain(BlockDriverState *bs)
+static void coroutine_fn bdrv_qed_co_drain_begin(BlockDriverState *bs)
{
BDRVQEDState *s = bs->opaque;
@@ -1608,7 +1608,7 @@ static BlockDriver bdrv_qed = {
.bdrv_check = bdrv_qed_check,
.bdrv_detach_aio_context = bdrv_qed_detach_aio_context,
.bdrv_attach_aio_context = bdrv_qed_attach_aio_context,
- .bdrv_co_drain = bdrv_qed_co_drain,
+ .bdrv_co_drain_begin = bdrv_qed_co_drain_begin,
};
static void bdrv_qed_init(void)
--
2.13.6
^ permalink raw reply related [flat|nested] 5+ messages in thread* [Qemu-devel] [PULL 3/3] block/throttle.c: add bdrv_co_drain_begin/end callbacks
2017-10-13 13:49 [Qemu-devel] [PULL 0/3] Block patches Stefan Hajnoczi
2017-10-13 13:49 ` [Qemu-devel] [PULL 1/3] block: add bdrv_co_drain_end callback Stefan Hajnoczi
2017-10-13 13:49 ` [Qemu-devel] [PULL 2/3] block: rename bdrv_co_drain to bdrv_co_drain_begin Stefan Hajnoczi
@ 2017-10-13 13:49 ` Stefan Hajnoczi
2017-10-16 14:54 ` [Qemu-devel] [PULL 0/3] Block patches Peter Maydell
3 siblings, 0 replies; 5+ messages in thread
From: Stefan Hajnoczi @ 2017-10-13 13:49 UTC (permalink / raw)
To: qemu-devel; +Cc: Peter Maydell, Manos Pitsidianakis, Stefan Hajnoczi
From: Manos Pitsidianakis <el13635@mail.ntua.gr>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Manos Pitsidianakis <el13635@mail.ntua.gr>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
block/throttle.c | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)
diff --git a/block/throttle.c b/block/throttle.c
index 5bca76300f..833175ac77 100644
--- a/block/throttle.c
+++ b/block/throttle.c
@@ -197,6 +197,21 @@ static bool throttle_recurse_is_first_non_filter(BlockDriverState *bs,
return bdrv_recurse_is_first_non_filter(bs->file->bs, candidate);
}
+static void coroutine_fn throttle_co_drain_begin(BlockDriverState *bs)
+{
+ ThrottleGroupMember *tgm = bs->opaque;
+ if (atomic_fetch_inc(&tgm->io_limits_disabled) == 0) {
+ throttle_group_restart_tgm(tgm);
+ }
+}
+
+static void coroutine_fn throttle_co_drain_end(BlockDriverState *bs)
+{
+ ThrottleGroupMember *tgm = bs->opaque;
+ assert(tgm->io_limits_disabled);
+ atomic_dec(&tgm->io_limits_disabled);
+}
+
static BlockDriver bdrv_throttle = {
.format_name = "throttle",
.protocol_name = "throttle",
@@ -226,6 +241,9 @@ static BlockDriver bdrv_throttle = {
.bdrv_reopen_abort = throttle_reopen_abort,
.bdrv_co_get_block_status = bdrv_co_get_block_status_from_file,
+ .bdrv_co_drain_begin = throttle_co_drain_begin,
+ .bdrv_co_drain_end = throttle_co_drain_end,
+
.is_filter = true,
};
--
2.13.6
^ permalink raw reply related [flat|nested] 5+ messages in thread