aio: add errp argument to aio_context_setup()

When aio_context_new() -> aio_context_setup() fails at startup it
doesn't really matter whether errors are returned to the caller or the
process terminates immediately.

However, it is not acceptable to terminate when hotplugging --object
iothread at runtime. Refactor aio_context_setup() so that errors can be
propagated. The next commit will set errp when fdmon_io_uring_setup()
fails.

Suggested-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20251104022933.618123-10-stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

diff --git a/include/block/aio.h b/include/block/aio.h
index 6cddf4d13bfe800c08dc3163f2a2354a3fc871ae..13b6d342383cd0daaa79ed8b03aa0c33392b394c 100644 (file)
--- a/include/block/aio.h
+++ b/include/block/aio.h
@@ -718,10 +718,13 @@ void qemu_set_current_aio_context(AioContext *ctx);
 /**
  * aio_context_setup:
  * @ctx: the aio context
+ * @errp: error pointer
  *
  * Initialize the aio context.
+ *
+ * Returns: true on success, false otherwise
  */
-void aio_context_setup(AioContext *ctx);
+bool aio_context_setup(AioContext *ctx, Error **errp);
 
 /**
  * aio_context_destroy:

diff --git a/util/aio-posix.c b/util/aio-posix.c
index bebd9ce3a2bc7f5d5ea9d310aeef8d604145e965..9806a75c12547f5d835d6c75dfe0d564bf283d57 100644 (file)
--- a/util/aio-posix.c
+++ b/util/aio-posix.c
@@ -718,7 +718,7 @@ bool aio_poll(AioContext *ctx, bool blocking)
     return progress;
 }
 
-void aio_context_setup(AioContext *ctx)
+bool aio_context_setup(AioContext *ctx, Error **errp)
 {
     ctx->fdmon_ops = &fdmon_poll_ops;
     ctx->epollfd = -1;
@@ -726,10 +726,11 @@ void aio_context_setup(AioContext *ctx)
 
     /* Use the fastest fd monitoring implementation if available */
     if (fdmon_io_uring_setup(ctx)) {
-        return;
+        return true;
     }
 
     fdmon_epoll_setup(ctx);
+    return true;
 }
 
 void aio_context_destroy(AioContext *ctx)

diff --git a/util/aio-win32.c b/util/aio-win32.c
index 18cc9fb7a9aa852db7cd5cabebcd5903738b836d..6e6f699e4b3564d5b3a0e75bc4da0b40c94ba4ab 100644 (file)
--- a/util/aio-win32.c
+++ b/util/aio-win32.c
@@ -419,8 +419,9 @@ bool aio_poll(AioContext *ctx, bool blocking)
     return progress;
 }
 
-void aio_context_setup(AioContext *ctx)
+bool aio_context_setup(AioContext *ctx, Error **errp)
 {
+    return true;
 }
 
 void aio_context_destroy(AioContext *ctx)

diff --git a/util/async.c b/util/async.c
index 95b1c6b610f8650b4b0d8d5c716f4d3129ed03b3..7030047cfb464cec6648eb2c7934bc2e039a476a 100644 (file)
--- a/util/async.c
+++ b/util/async.c
@@ -581,6 +581,7 @@ static void co_schedule_bh_cb(void *opaque)
 
 AioContext *aio_context_new(Error **errp)
 {
+    ERRP_GUARD();
     int ret;
     AioContext *ctx;
 
@@ -611,7 +612,10 @@ AioContext *aio_context_new(Error **errp)
      * you add any new resources to AioContext, it's probably best to acquire
      * them before aio_context_setup().
      */
-    aio_context_setup(ctx);
+    if (!aio_context_setup(ctx, errp)) {
+        event_notifier_cleanup(&ctx->notifier);
+        goto fail;
+    }
 
     g_source_set_can_recurse(&ctx->source, true);
     qemu_lockcnt_init(&ctx->list_lock);