update submodule and patches to QEMU 8.1.5

[pve-qemu.git] / debian / patches / extra / 0006-Revert-Revert-graph-lock-Disable-locking-for-now.patch

diff --git a/debian/patches/extra/0006-Revert-Revert-graph-lock-Disable-locking-for-now.patch b/debian/patches/extra/0006-Revert-Revert-graph-lock-Disable-locking-for-now.patch
deleted file mode 100644 (file)
index f0648d2..0000000
--- a/debian/patches/extra/0006-Revert-Revert-graph-lock-Disable-locking-for-now.patch
+++ /dev/null
@@ -1,140 +0,0 @@
-From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
-From: Fiona Ebner <f.ebner@proxmox.com>
-Date: Thu, 28 Sep 2023 10:07:03 +0200
-Subject: [PATCH] Revert "Revert "graph-lock: Disable locking for now""
-
-This reverts commit 3cce22defb4b0e47cf135444e30cc673cff5ebad.
-
-There are still some issues with graph locking, e.g. deadlocks during
-backup canceling [0]. Because the AioContext locks still exist, it
-should be safe to disable locking again.
-
-From the original 80fc5d2600 ("graph-lock: Disable locking for now"):
-
-> We don't currently rely on graph locking yet. It is supposed to replace
-> the AioContext lock eventually to enable multiqueue support, but as long
-> as we still have the AioContext lock, it is sufficient without the graph
-> lock. Once the AioContext lock goes away, the deadlock doesn't exist any
-> more either and this commit can be reverted. (Of course, it can also be
-> reverted while the AioContext lock still exists if the callers have been
-> fixed.)
-
-[0]: https://lists.nongnu.org/archive/html/qemu-devel/2023-09/msg00729.html
-
-Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
----
- block/graph-lock.c | 24 ++++++++++++++++++++++++
- 1 file changed, 24 insertions(+)
-
-diff --git a/block/graph-lock.c b/block/graph-lock.c
-index 5e66f01ae8..5c2873262a 100644
---- a/block/graph-lock.c
-+++ b/block/graph-lock.c
-@@ -30,8 +30,10 @@ BdrvGraphLock graph_lock;
- /* Protects the list of aiocontext and orphaned_reader_count */
- static QemuMutex aio_context_list_lock;
- 
-+#if 0
- /* Written and read with atomic operations. */
- static int has_writer;
-+#endif
- 
- /*
-  * A reader coroutine could move from an AioContext to another.
-@@ -88,6 +90,7 @@ void unregister_aiocontext(AioContext *ctx)
-     g_free(ctx->bdrv_graph);
- }
- 
-+#if 0
- static uint32_t reader_count(void)
- {
-     BdrvGraphRWlock *brdv_graph;
-@@ -105,12 +108,19 @@ static uint32_t reader_count(void)
-     assert((int32_t)rd >= 0);
-     return rd;
- }
-+#endif
- 
- void bdrv_graph_wrlock(BlockDriverState *bs)
- {
-+#if 0
-     AioContext *ctx = NULL;
- 
-     GLOBAL_STATE_CODE();
-+    /*
-+     * TODO Some callers hold an AioContext lock when this is called, which
-+     * causes deadlocks. Reenable once the AioContext locking is cleaned up (or
-+     * AioContext locks are gone).
-+     */
-     assert(!qatomic_read(&has_writer));
- 
-     /*
-@@ -158,11 +168,13 @@ void bdrv_graph_wrlock(BlockDriverState *bs)
-     if (ctx) {
-         aio_context_acquire(bdrv_get_aio_context(bs));
-     }
-+#endif
- }
- 
- void bdrv_graph_wrunlock(void)
- {
-     GLOBAL_STATE_CODE();
-+#if 0
-     QEMU_LOCK_GUARD(&aio_context_list_lock);
-     assert(qatomic_read(&has_writer));
- 
-@@ -174,10 +186,13 @@ void bdrv_graph_wrunlock(void)
- 
-     /* Wake up all coroutine that are waiting to read the graph */
-     qemu_co_enter_all(&reader_queue, &aio_context_list_lock);
-+#endif
- }
- 
- void coroutine_fn bdrv_graph_co_rdlock(void)
- {
-+    /* TODO Reenable when wrlock is reenabled */
-+#if 0
-     BdrvGraphRWlock *bdrv_graph;
-     bdrv_graph = qemu_get_current_aio_context()->bdrv_graph;
- 
-@@ -237,10 +252,12 @@ void coroutine_fn bdrv_graph_co_rdlock(void)
-             qemu_co_queue_wait(&reader_queue, &aio_context_list_lock);
-         }
-     }
-+#endif
- }
- 
- void coroutine_fn bdrv_graph_co_rdunlock(void)
- {
-+#if 0
-     BdrvGraphRWlock *bdrv_graph;
-     bdrv_graph = qemu_get_current_aio_context()->bdrv_graph;
- 
-@@ -258,6 +275,7 @@ void coroutine_fn bdrv_graph_co_rdunlock(void)
-     if (qatomic_read(&has_writer)) {
-         aio_wait_kick();
-     }
-+#endif
- }
- 
- void bdrv_graph_rdlock_main_loop(void)
-@@ -275,13 +293,19 @@ void bdrv_graph_rdunlock_main_loop(void)
- void assert_bdrv_graph_readable(void)
- {
-     /* reader_count() is slow due to aio_context_list_lock lock contention */
-+    /* TODO Reenable when wrlock is reenabled */
-+#if 0
- #ifdef CONFIG_DEBUG_GRAPH_LOCK
-     assert(qemu_in_main_thread() || reader_count());
- #endif
-+#endif
- }
- 
- void assert_bdrv_graph_writable(void)
- {
-     assert(qemu_in_main_thread());
-+    /* TODO Reenable when wrlock is reenabled */
-+#if 0
-     assert(qatomic_read(&has_writer));
-+#endif
- }