Eject / change of scsi-cd on a virtio-scsi dataplane bus causes abort() because the new BDS doesn't get proper bdrv_set_aio_context().
Store the AioContext in BB and do it in blk_insert_bs. That is done by Vladimir's patch. Other patches are to make sure such a bdrv_set_aio_context() doesn't interfere with other BBs using other nodes from this graph. RFC note: Unfortunately, a use-after-free crash in iotests 030 appears since patch 7, which I believe is a latent bug that bdrv_reopen is "reentered" in existing code, rather than from this series: > #4 0x0000561ab90425a7 in bdrv_reopen > #5 0x0000561ab8e1d28e in stream_complete > #6 0x0000561ab9048543 in block_job_defer_to_main_loop_bh > #7 0x0000561ab91305bc in aio_bh_call > #8 0x0000561ab9130659 in aio_bh_poll > #9 0x0000561ab9135656 in aio_poll > #10 0x0000561ab90a6cf5 in bdrv_flush > #11 0x0000561ab904285a in bdrv_reopen_prepare > #12 0x0000561ab90423f0 in bdrv_reopen_multiple > #13 0x0000561ab90425ef in bdrv_reopen > #14 0x0000561ab909fa49 in commit_active_start > #15 0x0000561ab8dd6ffb in qmp_block_commit > #16 0x0000561ab8ded485 in qmp_marshal_block_commit > #17 0x0000561ab9123e6c in do_qmp_dispatch > #18 0x0000561ab9123fa4 in qmp_dispatch > #19 0x0000561ab8ca26b7 in handle_qmp_command I have a fix that I'll post separately. The last patches are an alternative to patch 7, to "workaround" this in a really non-obvious way. Fam Fam Zheng (15): block: Define BLK_PERM_AIO_CONTEXT_CHANGE block-backend: Add blk_request_perm blockjob: Add BLK_PERM_AIO_CONTEXT_CHANGE shared perm on bs block: Propagate BLK_PERM_AIO_CONTEXT_CHANGE down the graph backup: Request BLK_PERM_AIO_CONTEXT_CHANGE on target backup: Do initial aio context move of target via BB interface mirror: Request aio context change permission on target commit: Allow aio context change on s->base mirror: Do initial aio context move of target via BB interface virtio-scsi: Request BLK_PERM_AIO_CONTEXT_CHANGE for dataplane virtio-blk: Request BLK_PERM_AIO_CONTEXT_CHANGE for dataplane nbd: Allow BLK_PERM_AIO_CONTEXT_CHANGE on BB block: Add perm assertion on blk_set_aio_context mirror: Lazily request aio context change permission on target Revert "mirror: Request aio context change permission on target" Vladimir Sementsov-Ogievskiy (1): blk: fix aio context loss on media change block.c | 20 ++++++++++++-------- block/backup.c | 11 ++++++++++- block/block-backend.c | 23 +++++++++++++++++++++++ block/commit.c | 3 ++- block/mirror.c | 10 ++++++++++ block/vvfat.c | 2 +- blockdev.c | 18 ------------------ blockjob.c | 3 +++ hw/block/dataplane/virtio-blk.c | 15 +++++++++++---- hw/scsi/virtio-scsi.c | 4 ++++ include/block/block.h | 7 ++++++- include/sysemu/block-backend.h | 1 + nbd/server.c | 6 ++++-- 13 files changed, 87 insertions(+), 36 deletions(-) -- 2.9.3
