From: Stefan Hajnoczi <stefa...@redhat.com>
The synchronous bdrv_aio_cancel() function needs the acb's AioContext so
it can call aio_poll() to wait for cancellation.
It turns out that all users run under the BQL in the main AioContext, so
this callback is not needed.
Remove the callback, mark bdrv_aio_cancel() GLOBAL_STATE_CODE just like
its blk_aio_cancel() caller, and poll the main loop AioContext.
The purpose of this cleanup is to identify bdrv_aio_cancel() as an API
that does not work with the multi-queue block layer.
Signed-off-by: Stefan Hajnoczi <stefa...@redhat.com>
Message-ID: <20230823235938.1398382-2-stefa...@redhat.com>
Reviewed-by: Kevin Wolf <kw...@redhat.com>
Signed-off-by: Kevin Wolf <kw...@redhat.com>
---
include/block/aio.h | 1 -
include/block/block-global-state.h | 2 ++
include/block/block-io.h | 1 -
block/block-backend.c | 17 -----------------
block/io.c | 23 ++++++++---------------
hw/nvme/ctrl.c | 7 -------
softmmu/dma-helpers.c | 8 --------
util/thread-pool.c | 8 --------
8 files changed, 10 insertions(+), 57 deletions(-)
diff --git a/include/block/aio.h b/include/block/aio.h
index 32042e8905..bcc165c974 100644
--- a/include/block/aio.h
+++ b/include/block/aio.h
@@ -31,7 +31,6 @@ typedef void BlockCompletionFunc(void *opaque, int ret);
typedef struct AIOCBInfo {
void (*cancel_async)(BlockAIOCB *acb);
- AioContext *(*get_aio_context)(BlockAIOCB *acb);
size_t aiocb_size;
} AIOCBInfo;
diff --git a/include/block/block-global-state.h
b/include/block/block-global-state.h
index f347199bff..ac2a605ef5 100644
--- a/include/block/block-global-state.h
+++ b/include/block/block-global-state.h
@@ -185,6 +185,8 @@ void bdrv_drain_all_begin_nopoll(void);
void bdrv_drain_all_end(void);
void bdrv_drain_all(void);
+void bdrv_aio_cancel(BlockAIOCB *acb);
+
int bdrv_has_zero_init_1(BlockDriverState *bs);
int bdrv_has_zero_init(BlockDriverState *bs);
BlockDriverState *bdrv_find_node(const char *node_name);
diff --git a/include/block/block-io.h b/include/block/block-io.h
index 6db48f2d35..f1c796a1ce 100644
--- a/include/block/block-io.h
+++ b/include/block/block-io.h
@@ -101,7 +101,6 @@ bdrv_co_delete_file_noerr(BlockDriverState *bs);
/* async block I/O */
-void bdrv_aio_cancel(BlockAIOCB *acb);
void bdrv_aio_cancel_async(BlockAIOCB *acb);
/* sg packet commands */
diff --git a/block/block-backend.c b/block/block-backend.c
index 4009ed5fed..a77295a198 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -33,8 +33,6 @@
#define NOT_DONE 0x7fffffff /* used while emulated sync operation in progress
*/
-static AioContext *blk_aiocb_get_aio_context(BlockAIOCB *acb);
-
typedef struct BlockBackendAioNotifier {
void (*attached_aio_context)(AioContext *new_context, void *opaque);
void (*detach_aio_context)(void *opaque);
@@ -103,7 +101,6 @@ typedef struct BlockBackendAIOCB {
} BlockBackendAIOCB;
static const AIOCBInfo block_backend_aiocb_info = {
- .get_aio_context = blk_aiocb_get_aio_context,
.aiocb_size = sizeof(BlockBackendAIOCB),
};
@@ -1545,16 +1542,8 @@ typedef struct BlkAioEmAIOCB {
bool has_returned;
} BlkAioEmAIOCB;
-static AioContext *blk_aio_em_aiocb_get_aio_context(BlockAIOCB *acb_)
-{
- BlkAioEmAIOCB *acb = container_of(acb_, BlkAioEmAIOCB, common);
-
- return blk_get_aio_context(acb->rwco.blk);
-}
-
static const AIOCBInfo blk_aio_em_aiocb_info = {
.aiocb_size = sizeof(BlkAioEmAIOCB),
- .get_aio_context = blk_aio_em_aiocb_get_aio_context,
};
static void blk_aio_complete(BlkAioEmAIOCB *acb)
@@ -2434,12 +2423,6 @@ AioContext *blk_get_aio_context(BlockBackend *blk)
return blk->ctx;
}
-static AioContext *blk_aiocb_get_aio_context(BlockAIOCB *acb)
-{
- BlockBackendAIOCB *blk_acb = DO_UPCAST(BlockBackendAIOCB, common, acb);
- return blk_get_aio_context(blk_acb->blk);
-}
-
int blk_set_aio_context(BlockBackend *blk, AioContext *new_context,
Error **errp)
{
diff --git a/block/io.c b/block/io.c
index 525c94b16a..1e2e62baa2 100644
--- a/block/io.c
+++ b/block/io.c
@@ -2950,25 +2950,18 @@ int bdrv_load_vmstate(BlockDriverState *bs, uint8_t
*buf,
/**************************************************************/
/* async I/Os */
+/**
+ * Synchronously cancels an acb. Must be called with the BQL held and the acb
+ * must be processed with the BQL held too (IOThreads are not allowed).
+ *
+ * Use bdrv_aio_cancel_async() instead when possible.
+ */
void bdrv_aio_cancel(BlockAIOCB *acb)
{
- IO_CODE();
+ GLOBAL_STATE_CODE();
qemu_aio_ref(acb);
bdrv_aio_cancel_async(acb);
- while (acb->refcnt > 1) {
- if (acb->aiocb_info->get_aio_context) {
- aio_poll(acb->aiocb_info->get_aio_context(acb), true);
- } else if (acb->bs) {
- /* qemu_aio_ref and qemu_aio_unref are not thread-safe, so
- * assert that we're not using an I/O thread. Thread-safe
- * code should use bdrv_aio_cancel_async exclusively.
- */
- assert(bdrv_get_aio_context(acb->bs) == qemu_get_aio_context());
- aio_poll(bdrv_get_aio_context(acb->bs), true);
- } else {
- abort();
- }
- }
+ AIO_WAIT_WHILE_UNLOCKED(NULL, acb->refcnt > 1);
qemu_aio_unref(acb);
}
diff --git a/hw/nvme/ctrl.c b/hw/nvme/ctrl.c
index 539d273553..ee7273daa1 100644
--- a/hw/nvme/ctrl.c
+++ b/hw/nvme/ctrl.c
@@ -2130,11 +2130,6 @@ static inline bool nvme_is_write(NvmeRequest *req)
rw->opcode == NVME_CMD_WRITE_ZEROES;
}
-static AioContext *nvme_get_aio_context(BlockAIOCB *acb)
-{
- return qemu_get_aio_context();
-}
-
static void nvme_misc_cb(void *opaque, int ret)
{
NvmeRequest *req = opaque;
@@ -3302,7 +3297,6 @@ static void nvme_flush_cancel(BlockAIOCB *acb)
static const AIOCBInfo nvme_flush_aiocb_info = {
.aiocb_size = sizeof(NvmeFlushAIOCB),
.cancel_async = nvme_flush_cancel,
- .get_aio_context = nvme_get_aio_context,
};
static void nvme_do_flush(NvmeFlushAIOCB *iocb);
@@ -6478,7 +6472,6 @@ static void nvme_format_cancel(BlockAIOCB *aiocb)
static const AIOCBInfo nvme_format_aiocb_info = {
.aiocb_size = sizeof(NvmeFormatAIOCB),
.cancel_async = nvme_format_cancel,
- .get_aio_context = nvme_get_aio_context,
};
static void nvme_format_set(NvmeNamespace *ns, uint8_t lbaf, uint8_t mset,
diff --git a/softmmu/dma-helpers.c b/softmmu/dma-helpers.c
index 2463964805..36211acc7e 100644
--- a/softmmu/dma-helpers.c
+++ b/softmmu/dma-helpers.c
@@ -206,17 +206,9 @@ static void dma_aio_cancel(BlockAIOCB *acb)
}
}
-static AioContext *dma_get_aio_context(BlockAIOCB *acb)
-{
- DMAAIOCB *dbs = container_of(acb, DMAAIOCB, common);
-
- return dbs->ctx;
-}
-
static const AIOCBInfo dma_aiocb_info = {
.aiocb_size = sizeof(DMAAIOCB),
.cancel_async = dma_aio_cancel,
- .get_aio_context = dma_get_aio_context,
};
BlockAIOCB *dma_blk_io(AioContext *ctx,
diff --git a/util/thread-pool.c b/util/thread-pool.c
index e3d8292d14..22f9ba3286 100644
--- a/util/thread-pool.c
+++ b/util/thread-pool.c
@@ -228,17 +228,9 @@ static void thread_pool_cancel(BlockAIOCB *acb)
}
-static AioContext *thread_pool_get_aio_context(BlockAIOCB *acb)
-{
- ThreadPoolElement *elem = (ThreadPoolElement *)acb;
- ThreadPool *pool = elem->pool;
- return pool->ctx;
-}
-
static const AIOCBInfo thread_pool_aiocb_info = {
.aiocb_size = sizeof(ThreadPoolElement),
.cancel_async = thread_pool_cancel,
- .get_aio_context = thread_pool_get_aio_context,
};
BlockAIOCB *thread_pool_submit_aio(ThreadPoolFunc *func, void *arg,
--
2.41.0
