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authorFam Zheng <famz@redhat.com>2017-08-15 21:07:39 +0800
committerEric Blake <eblake@redhat.com>2017-08-15 10:03:28 -0500
commit5f7772c4d0cf32f4e779fcd5a69ae4dae24aeebf (patch)
treef7d1089fd77f52013bea4df6e69c6e170e618ec6 /block/block-backend.c
parent3dff24f2dffc5f3aa46dc014122012848bd7959d (diff)
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block-backend: Defer shared_perm tightening migration completion
As in the case of nbd_export_new(), bdrv_invalidate_cache() can be called when migration is still in progress. In this case we are not ready to tighten the shared permissions fenced by blk->disable_perm. Defer to a VM state change handler. Signed-off-by: Fam Zheng <famz@redhat.com> Message-Id: <20170815130740.31229-4-famz@redhat.com> Signed-off-by: Eric Blake <eblake@redhat.com>
Diffstat (limited to 'block/block-backend.c')
-rw-r--r--block/block-backend.c41
1 files changed, 41 insertions, 0 deletions
diff --git a/block/block-backend.c b/block/block-backend.c
index 968438c..e9798e8 100644
--- 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 +69,7 @@ struct BlockBackend {
NotifierList remove_bs_notifiers, insert_bs_notifiers;
int quiesce_counter;
+ VMChangeStateEntry *vmsh;
};
typedef struct BlockBackendAIOCB {
@@ -129,6 +131,23 @@ 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 +166,24 @@ 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);
@@ -291,6 +328,10 @@ 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);