capture_time=2026-07-25T04:48:03+03:00
node=os-ott-data-3-2 ip=172.30.52.193 hypervisor=172.30.50.191 vm_uuid=8c055917-e0b8-da24-3078-00039b7e6c66 vdi=d202a2b3-97c4-4c19-8c76-14e23278064e tap_pid=372284 tap_minor=6
=== tap-ctl before GDB ===
pid=372284 minor=6 state=0 args=qcow2:/dev/VG_XenStorage-b0c68dbe-de25-8245-fa27-0ef4b005d39a/QCOW2-d202a2b3-97c4-4c19-8c76-14e23278064e
{ "name": "qcow2:/dev/VG_XenStorage-b0c68dbe-de25-8245-fa27-0ef4b005d39a/QCOW2-d202a2b3-97c4-4c19-8c76-14e23278064e", "secs": [ 64669431381, 283539852989 ], "images": [ { "name": "/dev/VG_XenStorage-b0c68dbe-de25-8245-fa27-0ef4b005d39a/QCOW2-d202a2b3-97c4-4c19-8c76-14e23278064e", "hits": [ 64669431381, 283539852989 ], "fail": [ 0, 0 ], "driver": { "type": 6, "name": "qcow2", "status": null } } ], "tap": { "minor": 6, "reqs": [ 0, 0 ], "kicks": [ 3, 0 ] }, "xenbus": { "pool": "td-xenio-default", "domid": 10, "devid": 832, "reqs": [ 15633224394, 15633224394 ], "kicks": [ 2835333934, 15633223124 ], "errors": { "msg": 0, "map": 0, "vbd": 0, "img": 0 } }, "FIXME_enospc_redirect_count": 0, "nbd_mirror_failed": 0, "reqs_outstanding": 0, "read_caching": "false" }

=== GDB tapdisk/ring capture ===
[New LWP 372286]
[New LWP 372294]
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib64/libthread_db.so.1".
0x00007ffa50995c73 in select () from /lib64/libc.so.6

Thread 3 (Thread 0x7ffa4ecab700 (LWP 372294) "tapdisk"):
#0  0x00007ffa50993fcf in ppoll () from /lib64/libc.so.6
No symbol table info available.
#1  0x00007ffa5265456d in ppoll (__ss=0x0, __timeout=0x0, __nfds=<optimized out>, __fds=<optimized out>) at /usr/include/bits/poll2.h:77
No locals.
#2  0x00007ffa5264bd59 in os_host_main_loop_wait (timeout=-1) at util/main-loop.c:361
        context = 0x7ffa480028c0
        ret = <optimized out>
        context = <optimized out>
        ret = <optimized out>
#3  main_loop_wait (nonblocking=nonblocking@entry=0) at util/main-loop.c:645
        mlpoll = {
          state = 0,
          timeout = 4294967295,
          pollfds = 0x7ffa48002a00
        }
        ret = <optimized out>
        timeout_ns = <optimized out>
#4  0x0000000000427617 in qcow2_open (opaque=0x16e1330) at block-qcow2.c:437
        o_flags = 16546
        err = <optimized out>
        i = <optimized out>
        s = 0x16e1330
        driver = 0x16e1230
        flags = <optimized out>
        name = <optimized out>
        options = <optimized out>
        file_layer = <optimized out>
        local_err = 0x0
        conf = 0x16e1350
        writethrough = false
        has_aio_native = <optimized out>
        cache = <optimized out>
        has_discard = <optimized out>
        discard = <optimized out>
        __func__ = "qcow2_open"
        bjob = <optimized out>
        _obj5 = <optimized out>
        __mptr = <optimized out>
#5  0x00007ffa5265336f in qemu_thread_start (args=0x166e6c0) at util/qemu-thread-posix.c:543
        __clframe = {
          __cancel_routine = <optimized out>,
          __cancel_arg = 0x0,
          __do_it = 1,
          __cancel_type = <optimized out>
        }
        qemu_thread_args = 0x166e6c0
        start_routine = 0x426fd0 <qcow2_open>
        arg = 0x16e1330
        r = <optimized out>
#6  0x00007ffa522aae25 in start_thread () from /lib64/libpthread.so.0
No symbol table info available.
#7  0x00007ffa5099ebad in clone () from /lib64/libc.so.6
No symbol table info available.

Thread 2 (Thread 0x7ffa4f60d700 (LWP 372286) "tapdisk"):
#0  0x00007ffa50998ec9 in syscall () from /lib64/libc.so.6
No symbol table info available.
#1  0x00007ffa52653d3a in qemu_futex_wait (val=<optimized out>, f=<optimized out>) at ../../include/qemu/futex.h:29
No locals.
#2  qemu_event_wait (ev=ev@entry=0x7ffa526aad28 <rcu_call_ready_event>) at util/qemu-thread-posix.c:464
        value = <optimized out>
        __PRETTY_FUNCTION__ = "qemu_event_wait"
#3  0x00007ffa52655dfa in call_rcu_thread (opaque=<optimized out>) at util/rcu.c:278
        tries = 0
        n = <optimized out>
        node = <optimized out>
#4  0x00007ffa5265336f in qemu_thread_start (args=0x166d9e0) at util/qemu-thread-posix.c:543
        __clframe = {
          __cancel_routine = <optimized out>,
          __cancel_arg = 0x0,
          __do_it = 1,
          __cancel_type = <optimized out>
        }
        qemu_thread_args = 0x166d9e0
        start_routine = 0x7ffa52655d70 <call_rcu_thread>
        arg = 0x0
        r = <optimized out>
#5  0x00007ffa522aae25 in start_thread () from /lib64/libpthread.so.0
No symbol table info available.
#6  0x00007ffa5099ebad in clone () from /lib64/libc.so.6
No symbol table info available.

Thread 1 (Thread 0x7ffa52573980 (LWP 372284) "tapdisk"):
#0  0x00007ffa50995c73 in select () from /lib64/libc.so.6
No symbol table info available.
#1  0x000000000042d19b in scheduler_wait_for_events (s=<optimized out>, s@entry=0x446238 <server+24>) at scheduler.c:437
        ret = <optimized out>
        tv = {
          tv_sec = 599,
          tv_usec = 617007
        }
        __func__ = "scheduler_wait_for_events"
#2  0x0000000000413d27 in tapdisk_server_iterate () at tapdisk-server.c:412
        ret = <optimized out>
        __func__ = "tapdisk_server_iterate"
#3  0x0000000000414315 in __tapdisk_server_run () at tapdisk-server.c:429
No locals.
#4  tapdisk_server_run () at tapdisk-server.c:899
        err = 0
        set = {
          __val = {16779841, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}
        }
        __func__ = "tapdisk_server_run"
#5  0x0000000000404f67 in main (argc=<optimized out>, argv=<optimized out>) at tapdisk2.c:160
        control = 0x1698060 "/var/run/blktap-control/ctl372284"
        c = <optimized out>
        err = 0
        nodaemon = 0
        out = 0x168dd10
        __func__ = "main"
$1 = {
  prev = 0x1699fe0,
  next = 0x1699fe0
}
$2 = (td_vbd_t *) 0x1699ef0
$3 = 6
$4 = 6
$5 = 17
$6 = 32
$7 = 32
$8 = {
  reqs = {
    in = 0,
    out = 0
  },
  kicks = {
    in = 3,
    out = 0
  }
}
$9 = 0
$10 = 0
$11 = 0
$12 = 0
$13 = {
  req_prod = 0,
  __req_event = 1,
  rsp_prod = 0,
  __rsp_event = 1,
  msg = 0 '\000',
  __rsvd = "\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000",
  entry = 0x7ffa4ecac040
}
[Inferior 1 (process 372284) detached]
=== tap-ctl after GDB ===
{ "name": "qcow2:/dev/VG_XenStorage-b0c68dbe-de25-8245-fa27-0ef4b005d39a/QCOW2-d202a2b3-97c4-4c19-8c76-14e23278064e", "secs": [ 64669431381, 283539852989 ], "images": [ { "name": "/dev/VG_XenStorage-b0c68dbe-de25-8245-fa27-0ef4b005d39a/QCOW2-d202a2b3-97c4-4c19-8c76-14e23278064e", "hits": [ 64669431381, 283539852989 ], "fail": [ 0, 0 ], "driver": { "type": 6, "name": "qcow2", "status": null } } ], "tap": { "minor": 6, "reqs": [ 0, 0 ], "kicks": [ 3, 0 ] }, "xenbus": { "pool": "td-xenio-default", "domid": 10, "devid": 832, "reqs": [ 15633224394, 15633224394 ], "kicks": [ 2835333934, 15633223124 ], "errors": { "msg": 0, "map": 0, "vbd": 0, "img": 0 } }, "FIXME_enospc_redirect_count": 0, "nbd_mirror_failed": 0, "reqs_outstanding": 0, "read_caching": "false" }