Signed-off-by: Kevin Wolf kw...@redhat.com
---
block/qcow2-cluster.c | 47 +++
block/qcow2.c | 28 +---
block/qcow2.h | 14 ++
3 files changed, 86 insertions(+), 3 deletions(-)
diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index be75c17..33e595a 100644
--- a/block/qcow2-cluster.c
+++ b/block/qcow2-cluster.c
@@ -791,6 +791,52 @@ out:
return i;
}
+struct KickL2Meta {
+QEMUBH *bh;
+QCowL2Meta *m;
+};
+
+static void kick_l2meta_bh(void *opaque)
+{
+struct KickL2Meta *k = opaque;
+QCowL2Meta *m = k-m;
+
+m-kick_l2meta = NULL;
+qemu_bh_delete(k-bh);
+g_free(k);
+
+if (m-sleeping) {
+qemu_coroutine_enter(m-co, NULL);
+}
+}
+
+static void kick_l2meta(QCowL2Meta *m)
+{
+struct KickL2Meta *k;
+
+if (m-kick_l2meta) {
+return;
+}
+
+k = g_malloc(sizeof(*k));
+k-bh = qemu_bh_new(kick_l2meta_bh, k);
+k-m = m;
+
+m-kick_l2meta = k;
+
+qemu_bh_schedule(k-bh);
+}
+
+void qcow2_delete_kick_l2meta_bh(void *opaque)
+{
+if (opaque) {
+struct KickL2Meta *k = opaque;
+
+qemu_bh_delete(k-bh);
+g_free(k);
+}
+}
+
/*
* 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
@@ -833,6 +879,7 @@ 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 3f169b8..57552aa 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -767,6 +767,13 @@ static void coroutine_fn process_l2meta(void *opaque)
int ret;
assert(s-l2meta_flush.reader 0);
+
+if (!s-in_l2meta_flush) {
+m-sleeping = true;
+co_sleep_ns(rt_clock, 100);
+m-sleeping = false;
+}
+
qemu_co_mutex_lock(s-lock);
ret = qcow2_alloc_cluster_link_l2(bs, m);
@@ -784,6 +791,7 @@ static void coroutine_fn process_l2meta(void *opaque)
/* Meanwhile some new dependencies could have accumulated */
qemu_co_queue_restart_all(m-dependent_requests);
+qcow2_delete_kick_l2meta_bh(m-kick_l2meta);
g_free(m);
qemu_co_rwlock_unlock(s-l2meta_flush);
@@ -792,6 +800,18 @@ static void coroutine_fn process_l2meta(void *opaque)
static bool qcow2_drain(BlockDriverState *bs)
{
BDRVQcowState *s = bs-opaque;
+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;
+}
+}
+s-in_l2meta_flush = false;
return !QLIST_EMPTY(s-cluster_allocs);
}
@@ -800,6 +820,9 @@ static inline coroutine_fn void
stop_l2meta(BlockDriverState *bs)
{
BDRVQcowState *s = bs-opaque;
+/* Kick the requests once if they are sleepeing and then just wait until
+ * they complete and we get the lock */
+qcow2_drain(bs);
qemu_co_rwlock_wrlock(s-l2meta_flush);
}
@@ -893,7 +916,6 @@ static coroutine_fn int qcow2_co_writev(BlockDriverState
*bs,
qemu_co_mutex_unlock(s-lock);
while (l2meta != NULL) {
-Coroutine *co;
QCowL2Meta *next;
ProcessL2Meta p = {
@@ -913,8 +935,8 @@ static coroutine_fn int qcow2_co_writev(BlockDriverState
*bs,
/* l2meta might already be freed after the coroutine has run */
next = l2meta-next;
-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 = next;
}
diff --git a/block/qcow2.h b/block/qcow2.h
index 46ed112..1d7cdab 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;
+
+/**
