On 30.06.25 13:27, Fiona Ebner wrote:
If a node below a filter node is resized, the size of the filter node
is now also refreshed (recursively for filter parents).
Signed-off-by: Fiona Ebner <f.eb...@proxmox.com>
---
block.c | 12 ++++++++++++
include/block/block_int-common.h | 2 +-
2 files changed, 13 insertions(+), 1 deletion(-)
What does this do for block job filter nodes, like mirror? If they
changed their length, we might have to consider whether the job also
needs to be amended somehow.
However, I assume it’s a safe (conservative) change for them because
such drivers don’t implement bdrv_co_getlength(), so
bdrv_co_refresh_total_sectors() will not change anything. Is that right
and intended?
Reviewed-by: Hanna Czenczek <hre...@redhat.com>
(Babbling below.)
diff --git a/block.c b/block.c
index bfd4340b24..449f814ebe 100644
--- a/block.c
+++ b/block.c
@@ -1497,6 +1497,17 @@ static void GRAPH_WRLOCK bdrv_child_cb_detach(BdrvChild
*child)
}
}
+static void coroutine_fn GRAPH_RDLOCK bdrv_child_cb_resize(BdrvChild *child)
+{
+ BlockDriverState *bs = child->opaque;
+
+ if (bs->drv && bs->drv->is_filter) {
Checking the role for BDRV_CHILD_FILTERED would be more generic; but it
would cause 'raw' nodes to be updated, too. But I don’t know whether we
want that or not, and excluding raw (i.e. not changing behavior there)
is certainly the safe option.
+ /* Best effort, ignore errors. */
+ bdrv_co_refresh_total_sectors(bs, bs->total_sectors);
+ bdrv_co_parent_cb_resize(bs);
This makes me wonder whether bdrv_co_refresh_total_sectors() should
itself call bdrv_co_parent_cb_resize(). Still not quite sure; if the
underlying image file is resized by an external party (and we notice
this by accident, more or less), maybe the guest device should be informed.
(One thing to consider, maybe, are nodes that unshare the resize
permission for a child. It’s probably not clever to call the resize CB
if that permission is unshared, so maybe just from that perspective, we
should keep that CB strictly inside of that explicit truncate path that
checks that permission (at least when growing images...).)
Anyway, again, this is the safe option.
Hanna
+ }
+}
+
static int bdrv_child_cb_update_filename(BdrvChild *c, BlockDriverState *base,
const char *filename,
bool backing_mask_protocol,
@@ -1529,6 +1540,7 @@ const BdrvChildClass child_of_bds = {
.detach = bdrv_child_cb_detach,
.inactivate = bdrv_child_cb_inactivate,
.change_aio_ctx = bdrv_child_cb_change_aio_ctx,
+ .resize = bdrv_child_cb_resize,
.update_filename = bdrv_child_cb_update_filename,
.get_parent_aio_context = child_of_bds_get_parent_aio_context,
};
diff --git a/include/block/block_int-common.h b/include/block/block_int-common.h
index 692a9696d1..6670db2f85 100644
--- a/include/block/block_int-common.h
+++ b/include/block/block_int-common.h
@@ -1023,7 +1023,7 @@ struct BdrvChildClass {
/*
* Notifies the parent that the child was resized.
*/
- void (*resize)(BdrvChild *child);
+ void GRAPH_RDLOCK_PTR (*resize)(BdrvChild *child);
/*
* Returns a name that is supposedly more useful for human users than the
