block: Make bdrv_child_get_parent_aio_context I/O

We want to use bdrv_child_get_parent_aio_context() from bdrv_parent_drained_{begin,end}_single(), both of which are "I/O or GS" functions. Prior to 3ed4f70, all the implementations were I/O code anyway. 3ed4f70 has put block jobs' AioContext field under the job mutex, so to make child_job_get_parent_aio_context() work in an I/O context, we need to take that lock there. Furthermore, blk_root_get_parent_aio_context() is not marked as anything, but is safe to run in an I/O context, so mark it that way now. (blk_get_aio_context() is an I/O code function.) With that done, all implementations explicitly are I/O code, so we can mark bdrv_child_get_parent_aio_context() as I/O code, too, so callers know it is safe to run from both GS and I/O contexts. Signed-off-by: Hanna Reitz <[email protected]> Message-Id: <[email protected]> Reviewed-by: Kevin Wolf <[email protected]> Signed-off-by: Kevin Wolf <[email protected]>
antangelo · Nov 10, 2022 · d5f8d79 · d5f8d79
1 parent e56b0c6
commit d5f8d79
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Showing 6 changed files with 8 additions and 5 deletions.
diff --git a/block.c b/block.c
@@ -1543,7 +1543,7 @@ const BdrvChildClass child_of_bds = {
 
 AioContext *bdrv_child_get_parent_aio_context(BdrvChild *c)
 {
-    GLOBAL_STATE_CODE();
+    IO_CODE();
     return c->klass->get_parent_aio_context(c);
 }
 

diff --git a/block/block-backend.c b/block/block-backend.c
@@ -311,6 +311,7 @@ static void blk_root_detach(BdrvChild *child)
 static AioContext *blk_root_get_parent_aio_context(BdrvChild *c)
 {
     BlockBackend *blk = c->opaque;
+    IO_CODE();
 
     return blk_get_aio_context(blk);
 }

diff --git a/blockjob.c b/blockjob.c
@@ -173,7 +173,8 @@ static bool child_job_change_aio_ctx(BdrvChild *c, AioContext *ctx,
 static AioContext *child_job_get_parent_aio_context(BdrvChild *c)
 {
     BlockJob *job = c->opaque;
-    GLOBAL_STATE_CODE();
+    IO_CODE();
+    JOB_LOCK_GUARD();
 
     return job->job.aio_context;
 }

diff --git a/include/block/block-global-state.h b/include/block/block-global-state.h
@@ -220,7 +220,6 @@ void coroutine_fn bdrv_co_lock(BlockDriverState *bs);
  */
 void coroutine_fn bdrv_co_unlock(BlockDriverState *bs);
 
-AioContext *bdrv_child_get_parent_aio_context(BdrvChild *c);
 bool bdrv_child_change_aio_context(BdrvChild *c, AioContext *ctx,
                                    GHashTable *visited, Transaction *tran,
                                    Error **errp);

diff --git a/include/block/block-io.h b/include/block/block-io.h
@@ -171,6 +171,8 @@ void bdrv_debug_event(BlockDriverState *bs, BlkdebugEvent event);
  */
 AioContext *bdrv_get_aio_context(BlockDriverState *bs);
 
+AioContext *bdrv_child_get_parent_aio_context(BdrvChild *c);
+
 /**
  * Move the current coroutine to the AioContext of @bs and return the old
  * AioContext of the coroutine. Increase bs->in_flight so that draining @bs

diff --git a/include/block/block_int-common.h b/include/block/block_int-common.h
@@ -911,8 +911,6 @@ struct BdrvChildClass {
                            GHashTable *visited, Transaction *tran,
                            Error **errp);
 
-    AioContext *(*get_parent_aio_context)(BdrvChild *child);
-
     /*
      * I/O API functions. These functions are thread-safe.
      *
@@ -929,6 +927,8 @@ struct BdrvChildClass {
      */
     const char *(*get_name)(BdrvChild *child);
 
+    AioContext *(*get_parent_aio_context)(BdrvChild *child);
+
     /*
      * If this pair of functions is implemented, the parent doesn't issue new
      * requests after returning from .drained_begin() until .drained_end() is