On 9/2/26 17:39, Denis V. Lunev wrote: > On 8/12/26 14:14, Denis V. Lunev wrote: >> This email originated from an IP that might not be authorized by the domain >> it was sent from. >> Do not click links or open attachments unless it is an email you expected to >> receive. >> qom-set of the 'drive' property is allowed on a realized device and ends >> up in bdrv_replace_child_bs(), which swaps the node a BdrvChild points to >> without telling the parent anything about it. Every other way the size of >> a node changes goes through bdrv_co_truncate(), which does notify, so a >> device model caching the size of its child has no way to learn that it >> changed. >> >> scsi-disk is the one really hurt by this. check_lba_range() validates >> every guest request against SCSIDevice.max_lba, filled in by >> scsi_disk_reset() and updated only by the READ CAPACITY(10) and (16) >> handlers. Point a scsi-hd at a larger node and every request past the end >> of the old one is refused with ILLEGAL REQUEST / LOGICAL BLOCK ADDRESS >> OUT OF RANGE for the whole life of the device, which Linux turns into >> EREMOTEIO for reads as well as writes. It is silent on the host: >> out-of-range requests are answered by scsi_check_condition() and never >> reach scsi_handle_rw_error(), so there is no BLOCK_IO_ERROR event and >> io-status stays 'ok'. virtio-blk and ide call blk_get_geometry() for >> every request, so they end up with a stale idea of the size but never >> refuse I/O the node underneath can serve. >> >> Signed-off-by: Denis V. Lunev <[email protected]> >> Cc: Kevin Wolf <[email protected]> >> Cc: Hanna Reitz <[email protected]> >> Cc: Paolo Bonzini <[email protected]> >> Cc: Fam Zheng <[email protected]> >> >> Denis V. Lunev (4): >> block: notify the parent when a replaced child has a different size >> scsi-disk: refresh the cached capacity from the resize callback >> tests/qtest/virtio-scsi: cover a replacement that changes the size >> tests/qemu-iotests/qom-set-drive: replace with a differently sized >> node >> >> block.c | 13 +++++ >> hw/scsi/scsi-disk.c | 16 ++++-- >> include/block/block_int-io.h | 3 ++ >> tests/qemu-iotests/tests/qom-set-drive | 14 +++-- >> tests/qemu-iotests/tests/qom-set-drive.out | 2 + >> tests/qtest/virtio-scsi-test.c | 63 ++++++++++++++++++++++ >> 6 files changed, 104 insertions(+), 7 deletions(-) >> >> >> base-commit: 3e3ccab106f879b1512f8e0d51a827dd4de30e22 > Kevin, Hanna, > > have you had a chance to take a look? > I think block tree is correct one to go through. > > Thank you in advance, > Den ping
