| Message ID | 20250130171240.286878-7-kwolf@redhat.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | block: Managing inactive nodes (QSD migration) | expand |
On Thu, Jan 30, 2025 at 06:12:37PM +0100, Kevin Wolf wrote: > In order for block_resize to fail gracefully on an inactive node instead > of crashing with an assertion failure in bdrv_co_write_req_prepare() > (called from bdrv_co_truncate()), we need to check for inactive nodes > also when they are attached as a root node and make sure that > BLK_PERM_RESIZE isn't among the permissions allowed for inactive nodes. > To this effect, don't enumerate the permissions that are incompatible > with inactive nodes any more, but allow only BLK_PERM_CONSISTENT_READ > for them. > > Signed-off-by: Kevin Wolf <kwolf@redhat.com> > --- > block.c | 7 +++++++ > block/block-backend.c | 2 +- > 2 files changed, 8 insertions(+), 1 deletion(-) Reviewed-by: Eric Blake <eblake@redhat.com>
diff --git a/block.c b/block.c index be6b71c314..fa6198bca3 100644 --- a/block.c +++ b/block.c @@ -3077,6 +3077,13 @@ bdrv_attach_child_common(BlockDriverState *child_bs, assert(child_class->get_parent_desc); GLOBAL_STATE_CODE(); + if (bdrv_is_inactive(child_bs) && (perm & ~BLK_PERM_CONSISTENT_READ)) { + g_autofree char *perm_names = bdrv_perm_names(perm); + error_setg(errp, "Permission '%s' unavailable on inactive node", + perm_names); + return NULL; + } + new_child = g_new(BdrvChild, 1); *new_child = (BdrvChild) { .bs = NULL, diff --git a/block/block-backend.c b/block/block-backend.c index d093f01f89..cc6f58ae78 100644 --- a/block/block-backend.c +++ b/block/block-backend.c @@ -253,7 +253,7 @@ static bool blk_can_inactivate(BlockBackend *blk) * guest. For block job BBs that satisfy this, we can just allow * it. This is the case for mirror job source, which is required * by libvirt non-shared block migration. */ - if (!(blk->perm & (BLK_PERM_WRITE | BLK_PERM_WRITE_UNCHANGED))) { + if (!(blk->perm & ~BLK_PERM_CONSISTENT_READ)) { return true; }
In order for block_resize to fail gracefully on an inactive node instead of crashing with an assertion failure in bdrv_co_write_req_prepare() (called from bdrv_co_truncate()), we need to check for inactive nodes also when they are attached as a root node and make sure that BLK_PERM_RESIZE isn't among the permissions allowed for inactive nodes. To this effect, don't enumerate the permissions that are incompatible with inactive nodes any more, but allow only BLK_PERM_CONSISTENT_READ for them. Signed-off-by: Kevin Wolf <kwolf@redhat.com> --- block.c | 7 +++++++ block/block-backend.c | 2 +- 2 files changed, 8 insertions(+), 1 deletion(-)