util: remove the obsolete non-blocking connect

[mirror_qemu.git] / block / block-backend.c

diff --git a/block/block-backend.c b/block/block-backend.c
index 968438c1495be3f2fdb03ea4cb94c60b07dc71fc..10317424011a34729ee2c9c643d3e1ea9e4ea19f 100644 (file)
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -20,6 +20,7 @@
 #include "qapi-event.h"
 #include "qemu/id.h"
 #include "trace.h"
+#include "migration/misc.h"
 
 /* Number of coroutines to reserve per attached device model */
 #define COROUTINE_POOL_RESERVATION 64
@@ -68,6 +69,8 @@ struct BlockBackend {
     NotifierList remove_bs_notifiers, insert_bs_notifiers;
 
     int quiesce_counter;
+    VMChangeStateEntry *vmsh;
+    bool force_allow_inactivate;
 };
 
 typedef struct BlockBackendAIOCB {
@@ -129,6 +132,23 @@ static const char *blk_root_get_name(BdrvChild *child)
     return blk_name(child->opaque);
 }
 
+static void blk_vm_state_changed(void *opaque, int running, RunState state)
+{
+    Error *local_err = NULL;
+    BlockBackend *blk = opaque;
+
+    if (state == RUN_STATE_INMIGRATE) {
+        return;
+    }
+
+    qemu_del_vm_change_state_handler(blk->vmsh);
+    blk->vmsh = NULL;
+    blk_set_perm(blk, blk->perm, blk->shared_perm, &local_err);
+    if (local_err) {
+        error_report_err(local_err);
+    }
+}
+
 /*
  * Notifies the user of the BlockBackend that migration has completed. qdev
  * devices can tighten their permissions in response (specifically revoke
@@ -147,6 +167,24 @@ static void blk_root_activate(BdrvChild *child, Error **errp)
 
     blk->disable_perm = false;
 
+    blk_set_perm(blk, blk->perm, BLK_PERM_ALL, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        blk->disable_perm = true;
+        return;
+    }
+
+    if (runstate_check(RUN_STATE_INMIGRATE)) {
+        /* Activation can happen when migration process is still active, for
+         * example when nbd_server_add is called during non-shared storage
+         * migration. Defer the shared_perm update to migration completion. */
+        if (!blk->vmsh) {
+            blk->vmsh = qemu_add_vm_change_state_handler(blk_vm_state_changed,
+                                                         blk);
+        }
+        return;
+    }
+
     blk_set_perm(blk, blk->perm, blk->shared_perm, &local_err);
     if (local_err) {
         error_propagate(errp, local_err);
@@ -155,6 +193,30 @@ static void blk_root_activate(BdrvChild *child, Error **errp)
     }
 }
 
+void blk_set_force_allow_inactivate(BlockBackend *blk)
+{
+    blk->force_allow_inactivate = true;
+}
+
+static bool blk_can_inactivate(BlockBackend *blk)
+{
+    /* If it is a guest device, inactivate is ok. */
+    if (blk->dev || blk_name(blk)[0]) {
+        return true;
+    }
+
+    /* Inactivating means no more writes to the image can be done,
+     * even if those writes would be changes invisible to the
+     * guest.  For block job BBs that satisfy this, we can just allow
+     * it.  This is the case for mirror job source, which is required
+     * by libvirt non-shared block migration. */
+    if (!(blk->perm & (BLK_PERM_WRITE | BLK_PERM_WRITE_UNCHANGED))) {
+        return true;
+    }
+
+    return blk->force_allow_inactivate;
+}
+
 static int blk_root_inactivate(BdrvChild *child)
 {
     BlockBackend *blk = child->opaque;
@@ -163,11 +225,7 @@ static int blk_root_inactivate(BdrvChild *child)
         return 0;
     }
 
-    /* Only inactivate BlockBackends for guest devices (which are inactive at
-     * this point because the VM is stopped) and unattached monitor-owned
-     * BlockBackends. If there is still any other user like a block job, then
-     * we simply can't inactivate the image. */
-    if (!blk->dev && !blk_name(blk)[0]) {
+    if (!blk_can_inactivate(blk)) {
         return -EPERM;
     }
 
@@ -291,6 +349,10 @@ static void blk_delete(BlockBackend *blk)
     if (blk->root) {
         blk_remove_bs(blk);
     }
+    if (blk->vmsh) {
+        qemu_del_vm_change_state_handler(blk->vmsh);
+        blk->vmsh = NULL;
+    }
     assert(QLIST_EMPTY(&blk->remove_bs_notifiers.notifiers));
     assert(QLIST_EMPTY(&blk->insert_bs_notifiers.notifiers));
     QTAILQ_REMOVE(&block_backends, blk, link);