Merge remote-tracking branch 'stefanha/block' into staging

# By Stefan Hajnoczi (4) and others
# Via Stefan Hajnoczi
* stefanha/block:
  dataplane: refuse to start if device is already in use
  dataplane: enable virtio-blk x-data-plane=on live migration
  migration: fix spice migration
  migration: notify migration state before starting thread
  block: Repair the throttling code.
  gluster: Add image resize support

Message-id: 1375112172-24863-1-git-send-email-stefanha@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

block.c

@@ -127,7 +127,7 @@ void bdrv_io_limits_disable(BlockDriverState *bs)
 {
     bs->io_limits_enabled = false;
 
-    while (qemu_co_queue_next(&bs->throttled_reqs));
+    do {} while (qemu_co_enter_next(&bs->throttled_reqs));
 
     if (bs->block_timer) {
         qemu_del_timer(bs->block_timer);
@@ -143,7 +143,7 @@ static void bdrv_block_timer(void *opaque)
 {
     BlockDriverState *bs = opaque;
 
-    qemu_co_queue_next(&bs->throttled_reqs);
+    qemu_co_enter_next(&bs->throttled_reqs);
 }
 
 void bdrv_io_limits_enable(BlockDriverState *bs)
@@ -1452,8 +1452,7 @@ void bdrv_drain_all(void)
          * a busy wait.
          */
         QTAILQ_FOREACH(bs, &bdrv_states, list) {
-            if (!qemu_co_queue_empty(&bs->throttled_reqs)) {
+            while (qemu_co_enter_next(&bs->throttled_reqs)) {
-                qemu_co_queue_restart_all(&bs->throttled_reqs);
                 busy = true;
             }
         }

block/gluster.c

@@ -493,6 +493,19 @@ out:
     return NULL;
 }
 
+static int qemu_gluster_truncate(BlockDriverState *bs, int64_t offset)
+{
+    int ret;
+    BDRVGlusterState *s = bs->opaque;
+
+    ret = glfs_ftruncate(s->fd, offset);
+    if (ret < 0) {
+        return -errno;
+    }
+
+    return 0;
+}
+
 static BlockDriverAIOCB *qemu_gluster_aio_readv(BlockDriverState *bs,
         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
         BlockDriverCompletionFunc *cb, void *opaque)
@@ -631,6 +644,7 @@ static BlockDriver bdrv_gluster = {
     .bdrv_create                  = qemu_gluster_create,
     .bdrv_getlength               = qemu_gluster_getlength,
     .bdrv_get_allocated_file_size = qemu_gluster_allocated_file_size,
+    .bdrv_truncate                = qemu_gluster_truncate,
     .bdrv_aio_readv               = qemu_gluster_aio_readv,
     .bdrv_aio_writev              = qemu_gluster_aio_writev,
     .bdrv_aio_flush               = qemu_gluster_aio_flush,
@@ -650,6 +664,7 @@ static BlockDriver bdrv_gluster_tcp = {
     .bdrv_create                  = qemu_gluster_create,
     .bdrv_getlength               = qemu_gluster_getlength,
     .bdrv_get_allocated_file_size = qemu_gluster_allocated_file_size,
+    .bdrv_truncate                = qemu_gluster_truncate,
     .bdrv_aio_readv               = qemu_gluster_aio_readv,
     .bdrv_aio_writev              = qemu_gluster_aio_writev,
     .bdrv_aio_flush               = qemu_gluster_aio_flush,
@@ -669,6 +684,7 @@ static BlockDriver bdrv_gluster_unix = {
     .bdrv_create                  = qemu_gluster_create,
     .bdrv_getlength               = qemu_gluster_getlength,
     .bdrv_get_allocated_file_size = qemu_gluster_allocated_file_size,
+    .bdrv_truncate                = qemu_gluster_truncate,
     .bdrv_aio_readv               = qemu_gluster_aio_readv,
     .bdrv_aio_writev              = qemu_gluster_aio_writev,
     .bdrv_aio_flush               = qemu_gluster_aio_flush,
@@ -688,6 +704,7 @@ static BlockDriver bdrv_gluster_rdma = {
     .bdrv_create                  = qemu_gluster_create,
     .bdrv_getlength               = qemu_gluster_getlength,
     .bdrv_get_allocated_file_size = qemu_gluster_allocated_file_size,
+    .bdrv_truncate                = qemu_gluster_truncate,
     .bdrv_aio_readv               = qemu_gluster_aio_readv,
     .bdrv_aio_writev              = qemu_gluster_aio_writev,
     .bdrv_aio_flush               = qemu_gluster_aio_flush,

hw/block/dataplane/virtio-blk.c

@@ -18,7 +18,6 @@
 #include "qemu/error-report.h"
 #include "hw/virtio/dataplane/vring.h"
 #include "ioq.h"
-#include "migration/migration.h"
 #include "block/block.h"
 #include "hw/virtio/virtio-blk.h"
 #include "virtio-blk.h"
@@ -69,8 +68,6 @@ struct VirtIOBlockDataPlane {
                                              queue */
 
     unsigned int num_reqs;
-
-    Error *migration_blocker;
 };
 
 /* Raise an interrupt to signal guest, if necessary */
@@ -418,6 +415,14 @@ bool virtio_blk_data_plane_create(VirtIODevice *vdev, VirtIOBlkConf *blk,
         return false;
     }
 
+    /* If dataplane is (re-)enabled while the guest is running there could be
+     * block jobs that can conflict.
+     */
+    if (bdrv_in_use(blk->conf.bs)) {
+        error_report("cannot start dataplane thread while device is in use");
+        return false;
+    }
+
     fd = raw_get_aio_fd(blk->conf.bs);
     if (fd < 0) {
         error_report("drive is incompatible with x-data-plane, "
@@ -433,10 +438,6 @@ bool virtio_blk_data_plane_create(VirtIODevice *vdev, VirtIOBlkConf *blk,
     /* Prevent block operations that conflict with data plane thread */
     bdrv_set_in_use(blk->conf.bs, 1);
 
-    error_setg(&s->migration_blocker,
-            "x-data-plane does not support migration");
-    migrate_add_blocker(s->migration_blocker);
-
     *dataplane = s;
     return true;
 }
@@ -448,8 +449,6 @@ void virtio_blk_data_plane_destroy(VirtIOBlockDataPlane *s)
     }
 
     virtio_blk_data_plane_stop(s);
-    migrate_del_blocker(s->migration_blocker);
-    error_free(s->migration_blocker);
     bdrv_set_in_use(s->blk->conf.bs, 0);
     g_free(s);
 }

hw/block/virtio-blk.c

@@ -19,6 +19,7 @@
 #include "hw/virtio/virtio-blk.h"
 #ifdef CONFIG_VIRTIO_BLK_DATA_PLANE
 # include "dataplane/virtio-blk.h"
+# include "migration/migration.h"
 #endif
 #include "block/scsi.h"
 #ifdef __linux__
@@ -628,6 +629,34 @@ void virtio_blk_set_conf(DeviceState *dev, VirtIOBlkConf *blk)
     memcpy(&(s->blk), blk, sizeof(struct VirtIOBlkConf));
 }
 
+#ifdef CONFIG_VIRTIO_BLK_DATA_PLANE
+/* Disable dataplane thread during live migration since it does not
+ * update the dirty memory bitmap yet.
+ */
+static void virtio_blk_migration_state_changed(Notifier *notifier, void *data)
+{
+    VirtIOBlock *s = container_of(notifier, VirtIOBlock,
+                                  migration_state_notifier);
+    MigrationState *mig = data;
+
+    if (migration_in_setup(mig)) {
+        if (!s->dataplane) {
+            return;
+        }
+        virtio_blk_data_plane_destroy(s->dataplane);
+        s->dataplane = NULL;
+    } else if (migration_has_finished(mig) ||
+               migration_has_failed(mig)) {
+        if (s->dataplane) {
+            return;
+        }
+        bdrv_drain_all(); /* complete in-flight non-dataplane requests */
+        virtio_blk_data_plane_create(VIRTIO_DEVICE(s), &s->blk,
+                                     &s->dataplane);
+    }
+}
+#endif /* CONFIG_VIRTIO_BLK_DATA_PLANE */
+
 static int virtio_blk_device_init(VirtIODevice *vdev)
 {
     DeviceState *qdev = DEVICE(vdev);
@@ -664,6 +693,8 @@ static int virtio_blk_device_init(VirtIODevice *vdev)
         virtio_cleanup(vdev);
         return -1;
     }
+    s->migration_state_notifier.notify = virtio_blk_migration_state_changed;
+    add_migration_state_change_notifier(&s->migration_state_notifier);
 #endif
 
     s->change = qemu_add_vm_change_state_handler(virtio_blk_dma_restart_cb, s);
@@ -683,6 +714,7 @@ static int virtio_blk_device_exit(DeviceState *dev)
     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
     VirtIOBlock *s = VIRTIO_BLK(dev);
 #ifdef CONFIG_VIRTIO_BLK_DATA_PLANE
+    remove_migration_state_change_notifier(&s->migration_state_notifier);
     virtio_blk_data_plane_destroy(s->dataplane);
     s->dataplane = NULL;
 #endif

include/block/coroutine.h

@@ -130,12 +130,17 @@ void coroutine_fn qemu_co_queue_wait_insert_head(CoQueue *queue);
  *
  * Returns true if a coroutine was restarted, false if the queue is empty.
  */
-bool qemu_co_queue_next(CoQueue *queue);
+bool coroutine_fn qemu_co_queue_next(CoQueue *queue);
 
 /**
  * Restarts all coroutines in the CoQueue and leaves the queue empty.
  */
-void qemu_co_queue_restart_all(CoQueue *queue);
+void coroutine_fn qemu_co_queue_restart_all(CoQueue *queue);
+
+/**
+ * Enter the next coroutine in the queue
+ */
+bool qemu_co_enter_next(CoQueue *queue);
 
 /**
  * Checks if the CoQueue is empty.

include/hw/virtio/virtio-blk.h

@@ -125,6 +125,7 @@ typedef struct VirtIOBlock {
     unsigned short sector_mask;
     VMChangeStateEntry *change;
 #ifdef CONFIG_VIRTIO_BLK_DATA_PLANE
+    Notifier migration_state_notifier;
     struct VirtIOBlockDataPlane *dataplane;
 #endif
 } VirtIOBlock;

include/migration/migration.h

@@ -90,7 +90,7 @@ int migrate_fd_close(MigrationState *s);
 
 void add_migration_state_change_notifier(Notifier *notify);
 void remove_migration_state_change_notifier(Notifier *notify);
-bool migration_is_active(MigrationState *);
+bool migration_in_setup(MigrationState *);
 bool migration_has_finished(MigrationState *);
 bool migration_has_failed(MigrationState *);
 MigrationState *migrate_get_current(void);

migration.c

@@ -338,9 +338,9 @@ void remove_migration_state_change_notifier(Notifier *notify)
     notifier_remove(notify);
 }
 
-bool migration_is_active(MigrationState *s)
+bool migration_in_setup(MigrationState *s)
 {
-    return s->state == MIG_STATE_ACTIVE;
+    return s->state == MIG_STATE_SETUP;
 }
 
 bool migration_has_finished(MigrationState *s)
@@ -658,7 +658,9 @@ void migrate_fd_connect(MigrationState *s)
     qemu_file_set_rate_limit(s->file,
                              s->bandwidth_limit / XFER_LIMIT_RATIO);
 
+    /* Notify before starting migration thread */
+    notifier_list_notify(&migration_state_notifiers, s);
+
     qemu_thread_create(&s->thread, migration_thread, s,
                        QEMU_THREAD_JOINABLE);
-    notifier_list_notify(&migration_state_notifiers, s);
 }

qemu-coroutine-lock.c

@@ -88,16 +88,32 @@ static bool qemu_co_queue_do_restart(CoQueue *queue, bool single)
     return true;
 }
 
-bool qemu_co_queue_next(CoQueue *queue)
+bool coroutine_fn qemu_co_queue_next(CoQueue *queue)
 {
+    assert(qemu_in_coroutine());
     return qemu_co_queue_do_restart(queue, true);
 }
 
-void qemu_co_queue_restart_all(CoQueue *queue)
+void coroutine_fn qemu_co_queue_restart_all(CoQueue *queue)
 {
+    assert(qemu_in_coroutine());
     qemu_co_queue_do_restart(queue, false);
 }
 
+bool qemu_co_enter_next(CoQueue *queue)
+{
+    Coroutine *next;
+
+    next = QTAILQ_FIRST(&queue->entries);
+    if (!next) {
+        return false;
+    }
+
+    QTAILQ_REMOVE(&queue->entries, next, co_queue_next);
+    qemu_coroutine_enter(next, NULL);
+    return true;
+}
+
 bool qemu_co_queue_empty(CoQueue *queue)
 {
     return (QTAILQ_FIRST(&queue->entries) == NULL);

ui/spice-core.c

@@ -563,7 +563,7 @@ static void migration_state_notifier(Notifier *notifier, void *data)
 {
     MigrationState *s = data;
 
-    if (migration_is_active(s)) {
+    if (migration_in_setup(s)) {
         spice_server_migrate_start(spice_server);
     } else if (migration_has_finished(s)) {
         spice_server_migrate_end(spice_server, true);