From: Emanuele Giuseppe Esposito <eesposit@redhat.com>
To: qemu-block@nongnu.org
Cc: Kevin Wolf <kwolf@redhat.com>,
Emanuele Giuseppe Esposito <eesposit@redhat.com>,
Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>,
qemu-devel@nongnu.org, Max Reitz <mreitz@redhat.com>,
Paolo Bonzini <pbonzini@redhat.com>, John Snow <jsnow@redhat.com>
Subject: [RFC PATCH 2/3] block-copy: add a CoMutex to the BlockCopyTask list
Date: Tue, 20 Apr 2021 12:04:15 +0200 [thread overview]
Message-ID: <20210420100416.30713-3-eesposit@redhat.com> (raw)
In-Reply-To: <20210420100416.30713-1-eesposit@redhat.com>
Because the list of tasks is only modified by coroutine
functions, add a CoMutex in order to protect the list of tasks.
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
---
block/block-copy.c | 23 +++++++++++++++++++----
1 file changed, 19 insertions(+), 4 deletions(-)
diff --git a/block/block-copy.c b/block/block-copy.c
index 03df50a354..e785ac57e0 100644
--- a/block/block-copy.c
+++ b/block/block-copy.c
@@ -65,7 +65,9 @@ typedef struct BlockCopyTask {
BlockCopyState *s;
BlockCopyCallState *call_state;
- /* State */
+ /* State. These fields are protected by the tasks_lock
+ * in BlockCopyState
+ */
int64_t offset;
int64_t bytes;
bool zeroes;
@@ -95,6 +97,8 @@ typedef struct BlockCopyState {
bool use_copy_range;
int64_t copy_size;
uint64_t len;
+
+ CoMutex tasks_lock;
QLIST_HEAD(, BlockCopyTask) tasks; /* All tasks from all block-copy calls */
QLIST_HEAD(, BlockCopyCallState) calls;
@@ -124,6 +128,7 @@ typedef struct BlockCopyState {
RateLimit rate_limit;
} BlockCopyState;
+/* Called with lock held */
static BlockCopyTask *find_conflicting_task(BlockCopyState *s,
int64_t offset, int64_t bytes)
{
@@ -145,13 +150,19 @@ static BlockCopyTask *find_conflicting_task(BlockCopyState *s,
static bool coroutine_fn block_copy_wait_one(BlockCopyState *s, int64_t offset,
int64_t bytes)
{
- BlockCopyTask *task = find_conflicting_task(s, offset, bytes);
+ BlockCopyTask *task;
+
+ qemu_co_mutex_lock(&s->tasks_lock);
+ task = find_conflicting_task(s, offset, bytes);
if (!task) {
+ qemu_co_mutex_unlock(&s->tasks_lock);
return false;
}
- qemu_co_queue_wait(&task->wait_queue, NULL);
+ qemu_co_queue_wait(&task->wait_queue, &s->tasks_lock);
+
+ qemu_co_mutex_unlock(&s->tasks_lock);
return true;
}
@@ -178,7 +189,9 @@ static BlockCopyTask *coroutine_fn block_copy_task_create(BlockCopyState *s,
bytes = QEMU_ALIGN_UP(bytes, s->cluster_size);
/* region is dirty, so no existent tasks possible in it */
+ qemu_co_mutex_lock(&s->tasks_lock);
assert(!find_conflicting_task(s, offset, bytes));
+ qemu_co_mutex_unlock(&s->tasks_lock);
bdrv_reset_dirty_bitmap(s->copy_bitmap, offset, bytes);
s->in_flight_bytes += bytes;
@@ -192,8 +205,9 @@ static BlockCopyTask *coroutine_fn block_copy_task_create(BlockCopyState *s,
.bytes = bytes,
};
qemu_co_queue_init(&task->wait_queue);
+ qemu_co_mutex_lock(&s->tasks_lock);
QLIST_INSERT_HEAD(&s->tasks, task, list);
-
+ qemu_co_mutex_unlock(&s->tasks_lock);
return task;
}
@@ -297,6 +311,7 @@ BlockCopyState *block_copy_state_new(BdrvChild *source, BdrvChild *target,
}
QLIST_INIT(&s->tasks);
+ qemu_co_mutex_init(&s->tasks_lock);
QLIST_INIT(&s->calls);
return s;
--
2.30.2
next prev parent reply other threads:[~2021-04-20 10:07 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-20 10:04 [RFC PATCH 0/3] block-copy: lock tasks and calls list Emanuele Giuseppe Esposito
2021-04-20 10:04 ` [RFC PATCH 1/3] block-copy: improve documentation for BlockCopyTask type and functions Emanuele Giuseppe Esposito
2021-04-20 12:03 ` Vladimir Sementsov-Ogievskiy
2021-04-20 12:51 ` Emanuele Giuseppe Esposito
2021-04-20 13:11 ` Vladimir Sementsov-Ogievskiy
2021-04-20 10:04 ` Emanuele Giuseppe Esposito [this message]
2021-04-20 10:04 ` [RFC PATCH 3/3] block-copy: add CoMutex lock for BlockCopyCallState list Emanuele Giuseppe Esposito
2021-04-20 13:12 ` [RFC PATCH 0/3] block-copy: lock tasks and calls list Vladimir Sementsov-Ogievskiy
2021-04-21 8:38 ` Paolo Bonzini
2021-04-21 8:53 ` Vladimir Sementsov-Ogievskiy
2021-04-21 12:13 ` Paolo Bonzini
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