From 3718d8ab65f68de2acccbe6a315907805f54e3cc Mon Sep 17 00:00:00 2001 From: Fam Zheng Date: Fri, 23 May 2014 21:29:43 +0800 Subject: block: Replace in_use with operation blocker This drops BlockDriverState.in_use with op_blockers: - Call bdrv_op_block_all in place of bdrv_set_in_use(bs, 1). - Call bdrv_op_unblock_all in place of bdrv_set_in_use(bs, 0). - Check bdrv_op_is_blocked() in place of bdrv_in_use(bs). The specific types are used, e.g. in place of starting block backup, bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_BACKUP, ...). There is one exception in block_job_create, where bdrv_op_blocker_is_empty() is used, because we don't know the operation type here. This doesn't matter because in a few commits away we will drop the check and move it to callers that _do_ know the type. - Check bdrv_op_blocker_is_empty() in place of assert(!bs->in_use). Note: there is only bdrv_op_block_all and bdrv_op_unblock_all callers at this moment. So although the checks are specific to op types, this changes can still be seen as identical logic with previously with in_use. The difference is error message are improved because of blocker error info. Signed-off-by: Fam Zheng Reviewed-by: Jeff Cody Reviewed-by: Stefan Hajnoczi Signed-off-by: Stefan Hajnoczi --- hw/block/dataplane/virtio-blk.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) (limited to 'hw') diff --git a/hw/block/dataplane/virtio-blk.c b/hw/block/dataplane/virtio-blk.c index 70b8a5a..e49c253 100644 --- a/hw/block/dataplane/virtio-blk.c +++ b/hw/block/dataplane/virtio-blk.c @@ -70,6 +70,9 @@ struct VirtIOBlockDataPlane { queue */ unsigned int num_reqs; + + /* Operation blocker on BDS */ + Error *blocker; }; /* Raise an interrupt to signal guest, if necessary */ @@ -350,6 +353,7 @@ void virtio_blk_data_plane_create(VirtIODevice *vdev, VirtIOBlkConf *blk, { VirtIOBlockDataPlane *s; int fd; + Error *local_err = NULL; *dataplane = NULL; @@ -372,9 +376,10 @@ void virtio_blk_data_plane_create(VirtIODevice *vdev, VirtIOBlkConf *blk, /* 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_setg(errp, - "cannot start dataplane thread while device is in use"); + if (bdrv_op_is_blocked(blk->conf.bs, BLOCK_OP_TYPE_DATAPLANE, &local_err)) { + error_report("cannot start dataplane thread: %s", + error_get_pretty(local_err)); + error_free(local_err); return; } @@ -406,8 +411,8 @@ void virtio_blk_data_plane_create(VirtIODevice *vdev, VirtIOBlkConf *blk, } s->ctx = iothread_get_aio_context(s->iothread); - /* Prevent block operations that conflict with data plane thread */ - bdrv_set_in_use(blk->conf.bs, 1); + error_setg(&s->blocker, "block device is in use by data plane"); + bdrv_op_block_all(blk->conf.bs, s->blocker); *dataplane = s; } @@ -420,7 +425,8 @@ void virtio_blk_data_plane_destroy(VirtIOBlockDataPlane *s) } virtio_blk_data_plane_stop(s); - bdrv_set_in_use(s->blk->conf.bs, 0); + bdrv_op_unblock_all(s->blk->conf.bs, s->blocker); + error_free(s->blocker); object_unref(OBJECT(s->iothread)); g_free(s); } -- cgit v1.1