On Tue, Apr 11, 2017 at 12:47 PM, Jeff Cody <jc...@redhat.com> wrote:
> On Mon, Apr 03, 2017 at 08:48:08PM -0700, Ashish Mittal wrote:
>> Source code for the qnio library that this code loads can be downloaded from:
>> https://github.com/VeritasHyperScale/libqnio.git
>>
>> Sample command line using JSON syntax:
>> ./x86_64-softmmu/qemu-system-x86_64 -name instance-00000008 -S -vnc 0.0.0.0:0
>> -k en-us -vga cirrus -device
>> virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x5
>> -msg timestamp=on
>> 'json:{"driver":"vxhs","vdisk-id":"c3e9095a-a5ee-4dce-afeb-2a59fb387410",
>> "server":{"host":"172.172.17.4","port":"9999"}}'
>>
>> Sample command line using URI syntax:
>> qemu-img convert -f raw -O raw -n
>> /var/lib/nova/instances/_base/0c5eacd5ebea5ed914b6a3e7b18f1ce734c386ad
>> vxhs://192.168.0.1:9999/c6718f6b-0401-441d-a8c3-1f0064d75ee0
>>
>> Sample command line using TLS credentials (run in secure mode):
>> ./qemu-io --object
>> tls-creds-x509,id=tls0,dir=/etc/pki/qemu/vxhs,endpoint=client -c 'read
>> -v 66000 2.5k' 'json:{"server.host": "127.0.0.1", "server.port": "9999",
>> "vdisk-id": "/test.raw", "driver": "vxhs", "tls-creds":"tls0"}'
>>
>> Signed-off-by: Ashish Mittal <ashish.mit...@veritas.com>
>
> I was testing this some with blockdev-add and blockdev-del, and this
> sequence causes a segfault:
>
> 1. blockdev-add vxhs image
> 2. blockdev-del above image
> 3. blockdev-add vxhs image <--- segfaults
>
> Looking at it in gdb, this is an issue with libqnio. The call to iio_fini()
> is not sufficiently thorough in cleaning up resources.
>
> In nio_client.c, qnc_ctx is never freed, because there does not
> seem to be a call such as 'qnc_driver_fini' that cleans up the allocated
> qnio_client_ctx.
>
> Therefore, on the second call to iio_init, the libqnio internal variable
> network_driver is NULL, because qnc_driver_init() returns NULL if it is
> called when qnc_ctx is still initialized:
>
>
>
> lib/qnio/nio_client.c:
>
> 411 int
> 412 iio_init(int32_t version, iio_cb_t cb)
> 413 {
>
> [...]
>
> 432 apictx->network_driver = qnc_secure_driver_init(client_callback);
> 433 nioDbg("Created API context.\n");
> 434 return 0;
> 435 }
>
> [...]
>
> 779 struct channel_driver *
> 780 qnc_driver_init(qnio_notify client_notify)
> 781 {
> 782 if (qnc_ctx) {
> 783 nioDbg("Driver already initialized");
> 784 return NULL;
> 785 }
> 786
>
>
> So two issues:
>
> A. iio_init() should check the returned pointer, and fail if NULL
>
> B. iio_fini() needs to clean everything up so that a new vxhs connection is
> possible. This likely means at least one new function in nio_client.c to
> clean up qnc_ctx.
>
> -Jeff
Thanks for reporting the issue and also suggesting the fix.
I was able to reproduce the issue and have checked in a fix to libqnio.
This was the stack trace from the core -
Program terminated with signal 11, Segmentation fault.
#0 0x00007f12083a3afa in iio_channel_open (uri=0x7f120c57eb70
"of://127.0.0.1:9999", cacert=0x0, client_key=0x0, client_cert=0x0) at
lib/qnio/iioapi.c:105
#1 0x00007f12083a470a in iio_open (uri=0x7f120d121be0
"of://127.0.0.1:9999", devid=0x7f120baa4bb0 "/test.raw", flags=0,
cacert=0x0, client_key=0x0, client_cert=0x0) at lib/qnio/iioapi.c:520
#2 0x00007f12091bf7a3 in vxhs_open (bs=<optimized out>,
options=<optimized out>, bdrv_flags=<optimized out>,
errp=0x7ffdf1cafd70) at block/vxhs.c:388
#3 0x00007f120916cf14 in bdrv_open_driver
(bs=bs@entry=0x7f120b1481b0, drv=drv@entry=0x7f1209843580 <bdrv_vxhs>,
node_name=<optimized out>, options=options@entry=0x7f120daa6840,
open_flags=8194,
errp=errp@entry=0x7ffdf1cafe28) at block.c:1011
#4 0x00007f120917079f in bdrv_open_common (errp=0x7ffdf1cafe28,
options=0x7f120daa6840, file=0x0, bs=0x7f120b1481b0) at block.c:1250
#5 bdrv_open_inherit (filename=<optimized out>, filename@entry=0x0,
reference=reference@entry=0x0, options=0x7f120daa6840,
options@entry=0x7f120daa4800, flags=40962, parent=parent@entry=0x0,
child_role=child_role@entry=0x0, errp=errp@entry=0x7ffdf1caff18)
at block.c:2413
#6 0x00007f1209171663 in bdrv_open (filename=filename@entry=0x0,
reference=reference@entry=0x0, options=options@entry=0x7f120daa4800,
flags=<optimized out>, errp=errp@entry=0x7ffdf1caff18)
at block.c:2505
#7 0x00007f1208f9f026 in bds_tree_init
(bs_opts=bs_opts@entry=0x7f120daa4800, errp=errp@entry=0x7ffdf1caff18)
at blockdev.c:656
#8 0x00007f1208fa4e5b in qmp_blockdev_add
(options=options@entry=0x7ffdf1caff20, errp=errp@entry=0x7ffdf1caff18)
at blockdev.c:3885
...
Please test again with refreshed libqnio and let me know in case of issues.
Thanks,
Ashish
