王松波你好,
Thanks a lot for reporting a bug and providing a patch for it. However,
you will need to send the patch using git send-email to this mailing
list: it will ease the review and integration in master.
Thanks a lot for your help,
--
Cedric
On Tue, 2015-06-02 at 20:27 +0800, 王松波 wrote:
> I report a bug [Bug 1227257] . In the environment
> libvirt-1.2.16.tar.gz + qemu-img version 2.1.2 + ceph version 0.94.1.
> libvirt pool will become inactive after one client does vol.delete and
> the other does pool.refresh in the same pool simultaneously.
>
>
> The reason is that rbd_list and rbd_open are not wrapped in an atomic
> operation, but two seperate operations.
> For example, two clients are operating in the same pool at the same
> time. One client does rbd_list, and got 10 rbd images, meanwhile, the
> other client deletes one of the rbd image. In this situation, when the
> first client does next operation, such as rbd_open , the command may
> fail, because the rbd image has been removed.
>
>
> I write a testcase in python to reproduce this problem as follow(also
> have put it in the attachment):
> ##################################
> import libvirt
> import sys
> import time
> import sys
> #coding:utf-8
>
>
> QEMU_URL = 'qemu:///system'
>
>
> VOL_TEMPLATE='''
> <volume>
> <name>{vol}</name>
> <key>{pool}/{vol}</key>
> <source>
> </source>
> <capacity unit='MB'>{cap_size}</capacity>
> <allocation unit='MB'>{alloc_size}</allocation>
> <target>
> <path>rbd:{pool}/{vol}</path>
> <format type='unknown'/>
> <permissions>
> <mode>00</mode>
> <owner>0</owner>
> <group>0</group>
> </permissions>
> </target>
> </volume>'''
>
>
> def create_vol(pool_name, vol_name, cap_size, alloc_size):
> conn = libvirt.open(QEMU_URL)
> if conn == None:
> print 'Failed to open connection to the hypervisor'
> sys.exit(1)
>
>
> try:
> pool = conn.storagePoolLookupByName(pool_name)
> pool.refresh()
> template = VOL_TEMPLATE.format(pool=pool_name, vol=vol_name,
> cap_size=cap_size, alloc_size=alloc_size)
> pool.createXML(template, 0)
> except:
> print 'Failed to open pool'
> sys.exit(1)
> finally:
> if conn is not None:
> conn.close()
>
>
> def destroy_vol(pool_name, vol_name):
> conn = libvirt.open(QEMU_URL)
> if conn == None:
> sys.exit(1)
> pool = conn.storagePoolLookupByName(pool_name)
> pool.refresh(0)
> vol = pool.storageVolLookupByName(vol_name)
> if vol is not None:
> vol.delete(0)
> if conn is not None:
> conn.close()
>
>
> if sys.argv[2] == 'create':
> for i in range(1, 20):
> volname = 'pool-down-test-%s-%d' % (sys.argv[1], i)
> print 'create %s' % volname
> create_vol('capacity', volname, '500', '500')
> elif sys.argv[2] == 'destroy':
> for i in range(1, 20):
> volname = 'pool-down-test-%s-%d' % (sys.argv[1], i)
> print 'destroy %s' % volname
> destroy_vol('capacity', volname)
> else:
> print 'Usage: python vol-test.py clientId OPER'
> print ' '
> print 'where clientId : a num/string used to distinguish
> different client'
> print ' OPER : create/destroy'
>
>
>
>
>
>
>
>
> Patch for this is as fllow:
>
>
> diff --git a/src/storage/storage_backend_rbd.c
> b/src/storage/storage_backend_rbd.c
> index ae4bcb3..24fbc84 100644
> --- a/src/storage/storage_backend_rbd.c
> +++ b/src/storage/storage_backend_rbd.c
> @@ -266,6 +266,46 @@ static int
> virStorageBackendRBDCloseRADOSConn(virStorageBackendRBDStatePtr ptr)
> return ret;
> }
>
>
> +static int volStorageBackendRBDVolIsExist(char *volname,
> virStorageBackendRBDStatePtr ptr)
> +{
> + int ret = -1;
> + char *name, *names = NULL;
> + size_t max_size = 1024;
> + int len = -1;
> +
> + while (true) {
> + if (VIR_ALLOC_N(names, max_size) < 0)
> + goto cleanup;
> +
> + len = rbd_list(ptr->ioctx, names, &max_size);
> + if (len >= 0)
> + break;
> + if (len != -ERANGE) {
> + VIR_WARN("%s", _("A problem occurred while listing RBD
> images"));
> + goto cleanup;
> + }
> + VIR_FREE(names);
> + }
> +
> + for (name = names; name < names + max_size;) {
> +
> + if (STREQ(name, ""))
> + break;
> +
> + name += strlen(name) + 1;
> + if (STREQ(volname, name)) {
> + VIR_ERROR("RBD images '%s' is exist, but cannot open it",
> volname);
> + ret = -2;
> + break;
> + }
> + }
> + ret = 0;
> +
> +cleanup:
> + VIR_FREE(names);
> + return ret;
> +}
> +
> static int volStorageBackendRBDRefreshVolInfo(virStorageVolDefPtr
> vol,
> virStoragePoolObjPtr
> pool,
>
> virStorageBackendRBDStatePtr ptr)
> @@ -276,8 +316,15 @@ static int
> volStorageBackendRBDRefreshVolInfo(virStorageVolDefPtr vol,
>
>
> r = rbd_open(ptr->ioctx, vol->name, &image, NULL);
> if (r < 0) {
> - virReportSystemError(-r, _("failed to open the RBD image '%
> s'"),
> - vol->name);
> + VIR_DEBUG("failed to open RBD image '%s', check if it was
> still exist in its pool",\
> + vol->name);
> + if (volStorageBackendRBDVolIsExist(vol->name, ptr) == 0) {
> + VIR_DEBUG("vol '%s' may be removed by the other rbd
> client", vol->name);
> + ret = 0;
> + } else {
> + virReportSystemError(-r, _("failed to open the RBD image
> '%s'"),
> + vol->name);
> + }
> return ret;
> }
> --
> libvir-list mailing list
> libvir-list@xxxxxxxxxx
> https://www.redhat.com/mailman/listinfo/libvir-list
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