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| author | Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> | 2021-08-24 11:38:32 +0300 |
|---|---|---|
| committer | Hanna Reitz <hreitz@redhat.com> | 2021-09-01 14:03:47 +0200 |
| commit | 3860c0201924d9f7f9b125b8bdda8a8627de4a08 (patch) | |
| tree | 87e548245ee4ccb1fbb2de505cbcec8b0092eb6d | |
| parent | b518e9e9ef7a28aa559a05d44dd734e83ae75f9d (diff) | |
| download | focaccia-qemu-3860c0201924d9f7f9b125b8bdda8a8627de4a08.tar.gz focaccia-qemu-3860c0201924d9f7f9b125b8bdda8a8627de4a08.zip | |
block/copy-before-write: relax permission requirements when no parents
We are going to publish copy-before-write filter. So, user should be able to create it with blockdev-add first, specifying both filtered and target children. And then do blockdev-reopen, to actually insert the filter where needed. Currently, filter unshares write permission unconditionally on source node. It's good, but it will not allow to do blockdev-add. So, let's relax restrictions when filter doesn't have any parent. Test output is modified, as now permission conflict happens only when job creates a blk parent for filter node. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20210824083856.17408-11-vsementsov@virtuozzo.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
Diffstat (limited to '')
| -rw-r--r-- | block/copy-before-write.c | 8 | ||||
| -rw-r--r-- | tests/qemu-iotests/283.out | 2 |
2 files changed, 6 insertions, 4 deletions
diff --git a/block/copy-before-write.c b/block/copy-before-write.c index a7996d54db..2a51cc64e4 100644 --- a/block/copy-before-write.c +++ b/block/copy-before-write.c @@ -142,10 +142,12 @@ static void cbw_child_perm(BlockDriverState *bs, BdrvChild *c, bdrv_default_perms(bs, c, role, reopen_queue, perm, shared, nperm, nshared); - if (perm & BLK_PERM_WRITE) { - *nperm = *nperm | BLK_PERM_CONSISTENT_READ; + if (!QLIST_EMPTY(&bs->parents)) { + if (perm & BLK_PERM_WRITE) { + *nperm = *nperm | BLK_PERM_CONSISTENT_READ; + } + *nshared &= ~(BLK_PERM_WRITE | BLK_PERM_RESIZE); } - *nshared &= ~(BLK_PERM_WRITE | BLK_PERM_RESIZE); } } diff --git a/tests/qemu-iotests/283.out b/tests/qemu-iotests/283.out index f2b7219632..5bb75952ef 100644 --- a/tests/qemu-iotests/283.out +++ b/tests/qemu-iotests/283.out @@ -5,7 +5,7 @@ {"execute": "blockdev-add", "arguments": {"driver": "blkdebug", "image": "base", "node-name": "other", "take-child-perms": ["write"]}} {"return": {}} {"execute": "blockdev-backup", "arguments": {"device": "source", "sync": "full", "target": "target"}} -{"error": {"class": "GenericError", "desc": "Cannot append copy-before-write filter: Permission conflict on node 'base': permissions 'write' are both required by node 'other' (uses node 'base' as 'image' child) and unshared by node 'source' (uses node 'base' as 'image' child)."}} +{"error": {"class": "GenericError", "desc": "Permission conflict on node 'base': permissions 'write' are both required by node 'other' (uses node 'base' as 'image' child) and unshared by node 'source' (uses node 'base' as 'image' child)."}} === copy-before-write filter should be gone after job-finalize === |