Signed-off-by: Kevin Wolf <kw...@redhat.com>
---
block/qcow2-cluster.c | 29 +++++++++++++++++++++++++++++
block/qcow2.c | 31 ++++++++++++++++++++++++++++---
block/qcow2.h | 10 ++++++++++
3 files changed, 67 insertions(+), 3 deletions(-)
diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index a89d68d..0f50888 100644
--- a/block/qcow2-cluster.c
+++ b/block/qcow2-cluster.c
@@ -791,6 +791,34 @@ out:
return i;
}
+struct KickL2Meta {
+ QEMUBH *bh;
+ QCowL2Meta *m;
+};
+
+static void kick_l2meta_bh(void *opaque)
+{
+ struct KickL2Meta *k = opaque;
+ QCowL2Meta *m = k->m;
+
+ qemu_bh_delete(k->bh);
+ free(k);
+
+ if (m->sleeping) {
+ qemu_coroutine_enter(m->co, NULL);
+ }
+}
+
+static void kick_l2meta(QCowL2Meta *m)
+{
+ struct KickL2Meta *k = g_malloc(sizeof(*k));
+
+ k->bh = qemu_bh_new(kick_l2meta_bh, k);
+ k->m = m;
+
+ qemu_bh_schedule(k->bh);
+}
+
/*
* Check if there already is an AIO write request in flight which allocates
* the same cluster. In this case we need to wait until the previous
@@ -823,6 +851,7 @@ static int handle_dependencies(BlockDriverState *bs,
uint64_t guest_offset,
/* Wait for the dependency to complete. We need to recheck
* the free/allocated clusters when we continue. */
qemu_co_mutex_unlock(&s->lock);
+ kick_l2meta(old_alloc);
qemu_co_queue_wait(&old_alloc->dependent_requests);
qemu_co_mutex_lock(&s->lock);
return -EAGAIN;
diff --git a/block/qcow2.c b/block/qcow2.c
index f9881d0..2e220c7 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -765,6 +765,12 @@ static void coroutine_fn process_l2meta(void *opaque)
BDRVQcowState *s = bs->opaque;
int ret;
+ if (!s->in_l2meta_flush) {
+ m->sleeping = true;
+ co_sleep_ns(rt_clock, 1000000);
+ m->sleeping = false;
+ }
+
qemu_co_mutex_lock(&s->lock);
ret = qcow2_alloc_cluster_link_l2(bs, m);
@@ -781,17 +787,37 @@ static void coroutine_fn process_l2meta(void *opaque)
static inline coroutine_fn void stop_l2meta(BDRVQcowState *s)
{
+ QCowL2Meta *m;
+
+ s->in_l2meta_flush = true;
+again:
+ QLIST_FOREACH(m, &s->cluster_allocs, next_in_flight) {
+ if (m->sleeping) {
+ qemu_coroutine_enter(m->co, NULL);
+ /* next_in_flight link could have become invalid */
+ goto again;
+ }
+ }
+
qemu_co_rwlock_wrlock(&s->l2meta_flush);
}
static inline coroutine_fn void resume_l2meta(BDRVQcowState *s)
{
+ s->in_l2meta_flush = false;
qemu_co_rwlock_unlock(&s->l2meta_flush);
}
static bool qcow2_drain(BlockDriverState *bs)
{
BDRVQcowState *s = bs->opaque;
+ QCowL2Meta *m;
+
+ QLIST_FOREACH(m, &s->cluster_allocs, next_in_flight) {
+ if (m->sleeping) {
+ qemu_coroutine_enter(m->co, NULL);
+ }
+ }
return !QLIST_EMPTY(&s->cluster_allocs);
}
@@ -876,7 +902,6 @@ static coroutine_fn int qcow2_co_writev(BlockDriverState
*bs,
}
if (l2meta != NULL) {
- Coroutine *co;
ProcessL2Meta p = {
.bs = bs,
.m = l2meta,
@@ -886,8 +911,8 @@ static coroutine_fn int qcow2_co_writev(BlockDriverState
*bs,
qemu_co_rwlock_rdlock(&s->l2meta_flush);
l2meta->is_written = true;
- co = qemu_coroutine_create(process_l2meta);
- qemu_coroutine_enter(co, &p);
+ l2meta->co = qemu_coroutine_create(process_l2meta);
+ qemu_coroutine_enter(l2meta->co, &p);
l2meta = NULL;
qemu_co_mutex_lock(&s->lock);
diff --git a/block/qcow2.h b/block/qcow2.h
index 73dac17..8bf145c 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -169,6 +169,7 @@ typedef struct BDRVQcowState {
* Writers: Anyone who requires l2meta to be flushed
*/
CoRwlock l2meta_flush;
+ bool in_l2meta_flush;
uint32_t crypt_method; /* current crypt method, 0 if no key yet */
uint32_t crypt_method_header;
@@ -245,6 +246,15 @@ typedef struct QCowL2Meta
bool is_written;
/**
+ * true if the request is sleeping in the COW delay and the coroutine may
+ * be reentered in order to cancel the timer.
+ */
+ bool sleeping;
+
+ /** Coroutine that handles delayed COW and updates L2 entry */
+ Coroutine *co;
+
+ /**
* Requests that overlap with this allocation and wait to be restarted
* when the allocating request has completed.
*/
--
1.7.6.5
