bdrv_check_perm is the qemu function that emits the message. Qemu runs as # id 64055 uid=64055(libvirt-qemu) gid=115(kvm) groups=115(kvm),64055(libvirt-qemu)
The images are made root:root by qemu itself. I made them, but it is not the classic file ownership that is missing: -rw-rw-rw- 1 libvirt-qemu kvm 458752 Apr 17 08:44 /var/lib/uvtool/libvirt/images/kvmguest-bionic-normal-ds.qcow -rw-rw-rw- 1 libvirt-qemu kvm 226361344 Apr 17 10:45 /var/lib/uvtool/libvirt/images/kvmguest-bionic-normal.qcow I see one EAGAIN and eventually one EPERM in (only the EPERM): Thread 1 "qemu-system-x86" hit Breakpoint 1, bdrv_check_perm (bs=bs@entry=0x556a76be7150, q=q@entry=0x0, cumulative_perms=3, cumulative_shared_perms=23, ignore_children=ignore_children@entry=0x0, errp=errp@entry=0x7ffd515f59b8) at ./block.c:1636 1636 in ./block.c (gdb) p *bs $12 = {open_flags = 10242, read_only = false, encrypted = false, sg = false, probed = false, force_share = false, implicit = false, drv = 0x556a74c48be0 <bdrv_qcow2>, opaque = 0x556a76bf1fd0, aio_context = 0x556a76bbe1e0, aio_notifiers = {lh_first = 0x0}, walking_aio_notifiers = false, filename = "/var/lib/uvtool/libvirt/images/kvmguest-bionic-normal.qcow", '\000' <repeats 4037 times>, backing_file = "/var/lib/uvtool/libvirt/images/x-uvt-b64-Y29tLnVidW50dS5jbG91ZC5kYWlseTpzZXJ2ZXI6MTguMDQ6YW1kNjQgMjAxODA0MTY=", '\000' <repeats 3986 times>, backing_format = "qcow2\000\000\000\000\000\000\000\000\000\000", full_open_options = 0x556a76c0b510, exact_filename = "/var/lib/uvtool/libvirt/images/kvmguest-bionic-normal.qcow", '\000' <repeats 4037 times>, backing = 0x556a76ba4a00, file = 0x556a76ba3e00, bl = {request_alignment = 1, max_pdiscard = 0, pdiscard_alignment = 65536, max_pwrite_zeroes = 0, pwrite_zeroes_alignment = 65536, opt_transfer = 0, max_transfer = 0, min_mem_alignment = 1, opt_mem_alignment = 4096, max_iov = 1024}, supported_write_flags = 0, supported_zero_flags = 4, node_name = "#block144", '\000' <repeats 22 times>, node_list = { tqe_next = 0x556a76c0d550, tqe_prev = 0x556a76bf07b0}, bs_list = {tqe_next = 0x556a76bed6f0, tqe_prev = 0x556a74c46990 <all_bdrv_states>}, monitor_list = {tqe_next = 0x0, tqe_prev = 0x0}, refcnt = 1, op_blockers = {{lh_first = 0x0} <repeats 16 times>}, job = 0x0, inherits_from = 0x0, children = {lh_first = 0x556a76ba4a00}, parents = {lh_first = 0x556a76b8d600}, options = 0x556a76be4970, explicit_options = 0x556a76bea3f0, detect_zeroes = BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF, backing_blocker = 0x556a76c12de0, total_sectors = 16777216, before_write_notifiers = {notifiers = {lh_first = 0x0}}, write_threshold_offset = 0, write_threshold_notifier = { notify = 0x0, node = {le_next = 0x0, le_prev = 0x0}}, dirty_bitmap_mutex = {lock = {__data = {__lock = 0, __count = 0, __owner = 0, __nusers = 0, __kind = 0, __spins = 0, __elision = 0, __list = {__prev = 0x0, __next = 0x0}}, __size = '\000' <repeats 39 times>, __align = 0}, initialized = true}, dirty_bitmaps = {lh_first = 0x0}, wr_highest_offset = {value = 0}, copy_on_read = 0, in_flight = 0, serialising_in_flight = 0, wakeup = false, io_plugged = 0, enable_write_cache = 0, quiesce_counter = 0, write_gen = 0, reqs_lock = { locked = 0, ctx = 0x0, from_push = {slh_first = 0x0}, to_pop = {slh_first = 0x0}, handoff = 0, sequence = 0, holder = 0x0}, tracked_requests = {lh_first = 0x0}, flush_queue = {entries = {sqh_first = 0x0, sqh_last = 0x556a76bea3d0}}, active_flush_req = false, flushed_gen = 0} (gdb) fin Run till exit from #0 bdrv_check_perm (bs=bs@entry=0x556a76be7150, q=q@entry=0x0, cumulative_perms=3, cumulative_shared_perms=23, ignore_children=ignore_children@entry=0x0, errp=errp@entry=0x7ffd515f59b8) at ./block.c:1636 bdrv_root_attach_child (child_bs=child_bs@entry=0x556a76be7150, child_name=child_name@entry=0x556a746dfae2 "root", child_role=child_role@entry=0x556a74bdcb80 <child_root>, perm=3, shared_perm=23, opaque=opaque@entry=0x556a76deb480, errp=0x7ffd515f59b8) at ./block.c:2042 2042 in ./block.c Value returned is $13 = -1 (gdb) c Continuing. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1764373 Title: copy-storage migrations fail on nbd-server-add To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/qemu/+bug/1764373/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs