v2: Use "bool" for external/internal instead of bit mask in the interface, so I didn't pick up Kevin's rev-by due to patches change. Add a unit test in tests/test-aio.c.
External I/O requests mustn't come in while we're in the middle of a QMP transaction. This series adds bdrv_drained_begin and bdrv_drained_end around "prepare" and "cleanup" in the transaction actions to make sure that. Note that "backup" action already starts the block job coroutine in prepare, and "snapshot" action already creates the snapshot, but both are OK because we call bdrv_drained_begin first. The nested event loops also dispatch timers and BHs on the same AioContext. The existing timers are iscsi, curl, qcow2 and qed. The only one that does I/O is qed, which is dealt with by a new ".bdrv_drain" callback. Fam Zheng (12): aio: Add "is_external" flag for event handlers nbd: Mark fd handlers client type as "external" dataplane: Mark host notifiers' client type as "external" aio: introduce aio_{disable,enable}_external block: Introduce "drained begin/end" API block: Add "drained begin/end" for transactional external snapshot block: Add "drained begin/end" for transactional backup block: Add "drained begin/end" for transactional blockdev-backup block: Add "drained begin/end" for internal snapshot block: Introduce BlockDriver.bdrv_drain callback qed: Implement .bdrv_drain tests: Add test case for aio_disable_external aio-posix.c | 9 ++++- aio-win32.c | 8 +++- async.c | 3 +- block.c | 2 + block/curl.c | 14 ++++--- block/io.c | 21 +++++++++++ block/iscsi.c | 9 ++--- block/linux-aio.c | 5 ++- block/nbd-client.c | 10 +++-- block/nfs.c | 17 ++++----- block/qed.c | 7 ++++ block/sheepdog.c | 38 ++++++++++++------- block/ssh.c | 5 ++- block/win32-aio.c | 5 ++- blockdev.c | 27 +++++++++++--- hw/block/dataplane/virtio-blk.c | 5 ++- hw/scsi/virtio-scsi-dataplane.c | 22 +++++++---- include/block/aio.h | 39 ++++++++++++++++++++ include/block/block.h | 19 ++++++++++ include/block/block_int.h | 8 ++++ iohandler.c | 3 +- nbd.c | 4 +- tests/test-aio.c | 82 ++++++++++++++++++++++++++++------------- 23 files changed, 270 insertions(+), 92 deletions(-) -- 2.6.1