This series is the first part of implementing the new op blocker system whose design was agreed on quite a while ago, but proved a bit tricky to implement in places. There is more work to do to fully replace the old op blocker system, but realistically we don't have that much time until the 2.9 freeze. So let's merge this series to complement the traditional op blockers and plan with a second part for the 2.10 timeframe.
The basic idea is that every user of a block node (including things outside the block layer that go through a BlockBackend, and also other block nodes that hold references to it) has to declare which low-level operations/permissions it needs and which operation it allows other users to perform on the same node. Depending on these declarations, conflicts are avoided by returning an error for attempts to attach a conflicting user to the same node. After this series, all users request permissions, and hopefully all of the permissions they need. For writes and resize, getting the permission first is actually enforced with assertions. Asserting it for consistent reads is in theory doable, but would mean introducing a request flag that tell us that inconsistent reads are okay - and that in all block drivers to recursively propagate this flag through the backing chain. It might not be worth it. As stated above, the series doesn't remove the old op blockers yet, though in theory the new op blockers should block everything that needs to be blocked. In practice, the read/write/resize blockers should be okay, but BLK_PERM_GRAPH_MOD isn't to be taken too seriously at the moment. It isn't really applied consistently and doesn't do much useful yet. Making proper use of it is left for the part 2 series. Kevin Wolf (44): block: Add op blocker permission constants block: Add Error argument to bdrv_attach_child() block: Let callers request permissions when attaching a child node block: Involve block drivers in permission granting block: Default .bdrv_child_perm() for filter drivers block: Request child permissions in filter drivers block: Default .bdrv_child_perm() for format drivers block: Request child permissions in format drivers vvfat: Implement .bdrv_child_perm() block: Require .bdrv_child_perm() with child nodes block: Request real permissions in bdrv_attach_child() block: Add permissions to BlockBackend block: Add permissions to blk_new() block: Add error parameter to blk_insert_bs() block: Add BDRV_O_RESIZE for blk_new_open() block: Request real permissions in blk_new_open() block: Allow error return in BlockDevOps.change_media_cb() hw/block: Request permissions hw/block: Introduce share-rw qdev property blockjob: Add permissions to block_job_create() block: Add BdrvChildRole.get_parent_desc() block: Include details on permission errors in message block: Add BdrvChildRole.stay_at_node blockjob: Add permissions to block_job_add_bdrv() commit: Use real permissions in commit block job commit: Use real permissions for HMP 'commit' backup: Use real permissions in backup block job block: Fix pending requests check in bdrv_append() block: BdrvChildRole.attach/detach() callbacks block: Allow backing file links in change_parent_backing_link() blockjob: Factor out block_job_remove_all_bdrv() mirror: Use real permissions in mirror/active commit block job stream: Use real permissions in streaming block job mirror: Add filter-node-name to blockdev-mirror commit: Add filter-node-name to block-commit hmp: Request permissions in qemu-io migration/block: Use real permissions nbd/server: Use real permissions for NBD exports tests: Remove FIXME comments block: Pass BdrvChild to bdrv_aligned_preadv/pwritev and copy-on-read block: Assertions for write permissions block: Assertions for resize permission block: Add Error parameter to bdrv_set_backing_hd() block: Add Error parameter to bdrv_append() block.c | 583 ++++++++++++++++++++++++++++++++++----- block/backup.c | 22 +- block/blkdebug.c | 2 + block/blkreplay.c | 1 + block/blkverify.c | 1 + block/block-backend.c | 116 +++++++- block/bochs.c | 1 + block/cloop.c | 1 + block/commit.c | 176 ++++++++++-- block/crypto.c | 1 + block/dmg.c | 1 + block/io.c | 41 +-- block/mirror.c | 237 ++++++++++++++-- block/parallels.c | 4 +- block/qcow.c | 4 +- block/qcow2.c | 19 +- block/qed.c | 4 +- block/quorum.c | 11 +- block/raw-format.c | 1 + block/replication.c | 3 +- block/sheepdog.c | 2 +- block/stream.c | 47 +++- block/vdi.c | 4 +- block/vhdx.c | 4 +- block/vmdk.c | 7 +- block/vpc.c | 4 +- block/vvfat.c | 24 +- blockdev.c | 74 ++++- blockjob.c | 62 ++++- hmp.c | 33 ++- hw/block/block.c | 24 +- hw/block/fdc.c | 28 +- hw/block/m25p80.c | 8 + hw/block/nand.c | 7 + hw/block/nvme.c | 8 +- hw/block/onenand.c | 7 + hw/block/pflash_cfi01.c | 18 +- hw/block/pflash_cfi02.c | 19 +- hw/block/virtio-blk.c | 8 +- hw/core/qdev-properties-system.c | 9 +- hw/ide/core.c | 2 +- hw/ide/qdev.c | 9 +- hw/nvram/spapr_nvram.c | 8 + hw/scsi/scsi-disk.c | 12 +- hw/sd/sd.c | 8 +- hw/usb/dev-storage.c | 6 +- include/block/block.h | 46 ++- include/block/block_int.h | 126 ++++++++- include/block/blockjob.h | 14 +- include/block/blockjob_int.h | 4 +- include/hw/block/block.h | 8 +- include/qemu-io.h | 1 + include/sysemu/block-backend.h | 9 +- migration/block.c | 21 +- nbd/server.c | 16 +- qapi/block-core.json | 16 +- qemu-img.c | 12 +- qemu-io-cmds.c | 28 ++ tests/qemu-iotests/051.pc.out | 6 +- tests/qemu-iotests/055 | 11 +- tests/qemu-iotests/085.out | 2 +- tests/qemu-iotests/141 | 2 +- tests/qemu-iotests/141.out | 4 +- tests/qemu-iotests/172.out | 53 ++++ tests/test-blockjob-txn.c | 6 +- tests/test-blockjob.c | 10 +- tests/test-throttle.c | 7 +- 67 files changed, 1786 insertions(+), 287 deletions(-) -- 1.8.3.1
