Re: Issue with Targetcli -- Python error - F20

[Christophe Vu-Brugier]

Hi,

On Thu, 19 Jun 2014 17:12:51 -0400, deeepdish wrote :
>  I'm trying to create a block backstore in targetcli on a newly 
>  installed Fedora 20 system.
>  
>  I can confirm this is working on another Fedora 20 system (installed 
>  about a month ago), and am wondering if there's an update somewhere 
>  that may be impacting targetcli.
>  
>  Here's what I'm attempting:
>  
>  [root@bl05ssn09 ~]# lvcreate -n TEST -L 1G data
>    Logical volume "TEST" created
>  [root@bl05ssn09 ~]# targetcli
>  targetcli shell version 2.1.fb35
>  Copyright 2011-2013 by Datera, Inc and others.
>  For help on commands, type 'help'.
>  
>  /backstores/block> create name=test dev=/dev/data/TEST
>  Traceback (most recent call last):
>    File "/usr/bin/targetcli", line 100, in <module>
>      main()
>    File "/usr/bin/targetcli", line 90, in main
>      shell.run_interactive()
>    File "/usr/lib/python2.7/site-packages/configshell/shell.py", line 
>  948, in run_interactive
>      self._cli_loop()
>    File "/usr/lib/python2.7/site-packages/configshell/shell.py", line 
>  777, in _cli_loop
>      self.run_cmdline(cmdline)
>    File "/usr/lib/python2.7/site-packages/configshell/shell.py", line 
>  891, in run_cmdline
>      self._execute_command(path, command, pparams, kparams)
>    File "/usr/lib/python2.7/site-packages/configshell/shell.py", line 
>  866, in _execute_command
>      result = target.execute_command(command, pparams, kparams)
>    File "/usr/lib/python2.7/site-packages/configshell/node.py", line 
>  1413, in execute_command
>      return method(*pparams, **kparams)
>    File "/usr/lib/python2.7/site-packages/targetcli/ui_backstore.py", 
>  line 387, in ui_command_create
>      so = BlockStorageObject(name, dev, readonly=readonly, 
>  write_back=write_back)
>    File "/usr/lib/python2.7/site-packages/rtslib/tcm.py", line 677, in
>  __init__ raise
>  TypeError: exceptions must be old-style classes or derived from 
>  BaseException, not NoneType
>  
>  [root@bl05ssn09 ~]# targetcli /backstores/block create name=test 
>  dev=/dev/data/TEST
>  exceptions must be old-style classes or derived from BaseException,
>  not NoneType
>  [root@bl05ssn09 ~]# 
I managed to reproduce your bug on a Fedora 20 with a 3.14 kernel
(3.14.6-200.fc20.x86_64). The exception happens in the following part
of tcm.py:

At line 694 in BlockStorageObject._configure():

  if write_back:
      self.set_attribute("emulate_write_cache", 1)

The set_attribute() method fails because of a permission denied error.

As a workaround, you can comment out the two instructions in the
following file :

  /usr/lib/python2.7/site-packages/rtslib/tcm.py

Best regards,

-- 
Christophe Vu-Brugier

Issue with Targetcli -- Python error - F20

[Andy Grover]

On 06/20/2014 11:00 AM, Christophe Vu-Brugier wrote:
>  Hi,
>
>  On Thu, 19 Jun 2014 17:12:51 -0400, deeepdish wrote :
> > I'm trying to create a block backstore in targetcli on a newly
> > installed Fedora 20 system.
> >
> > I can confirm this is working on another Fedora 20 system (installed
> > about a month ago), and am wondering if there's an update somewhere
> > that may be impacting targetcli.
> >
> > Here's what I'm attempting:
> >
> > [root@bl05ssn09 ~]# lvcreate -n TEST -L 1G data
> >    Logical volume "TEST" created
> > [root@bl05ssn09 ~]# targetcli
> > targetcli shell version 2.1.fb35
> > Copyright 2011-2013 by Datera, Inc and others.
> > For help on commands, type 'help'.
> >
> > /backstores/block> create name=test dev=/dev/data/TEST
> > Traceback (most recent call last):
> >    File "/usr/bin/targetcli", line 100, in <module>
> >      main()
> >    File "/usr/bin/targetcli", line 90, in main
> >      shell.run_interactive()
> >    File "/usr/lib/python2.7/site-packages/configshell/shell.py", line
> > 948, in run_interactive
> >      self._cli_loop()
> >    File "/usr/lib/python2.7/site-packages/configshell/shell.py", line
> > 777, in _cli_loop
> >      self.run_cmdline(cmdline)
> >    File "/usr/lib/python2.7/site-packages/configshell/shell.py", line
> > 891, in run_cmdline
> >      self._execute_command(path, command, pparams, kparams)
> >    File "/usr/lib/python2.7/site-packages/configshell/shell.py", line
> > 866, in _execute_command
> >      result = target.execute_command(command, pparams, kparams)
> >    File "/usr/lib/python2.7/site-packages/configshell/node.py", line
> > 1413, in execute_command
> >      return method(*pparams, **kparams)
> >    File "/usr/lib/python2.7/site-packages/targetcli/ui_backstore.py",
> > line 387, in ui_command_create
> >      so = BlockStorageObject(name, dev, readonly=readonly,
> > write_back=write_back)
> >    File "/usr/lib/python2.7/site-packages/rtslib/tcm.py", line 677, in
> > __init__ raise
> > TypeError: exceptions must be old-style classes or derived from
> > BaseException, not NoneType
> >
> > [root@bl05ssn09 ~]# targetcli /backstores/block create name=test
> > dev=/dev/data/TEST
> > exceptions must be old-style classes or derived from BaseException,
> > not NoneType
> > [root@bl05ssn09 ~]#
>
>  I managed to reproduce your bug on a Fedora 20 with a 3.14 kernel
>  (3.14.6-200.fc20.x86_64). The exception happens in the following part
>  of tcm.py:
>
>  At line 694 in BlockStorageObject._configure():
>
>     if write_back:
>         self.set_attribute("emulate_write_cache", 1)
>
>  The set_attribute() method fails because of a permission denied error.
>
>  As a workaround, you can comment out the two instructions in the
>  following file :
>
>     /usr/lib/python2.7/site-packages/rtslib/tcm.py
>
>  Best regards, 
Thanks for diagnosing the issue!

This actually is fixed in rtslib-fb git repo, but hasn't been tagged 
into a release. I'll go ahead and do that.

Thanks again -- Regards -- Andy

Issue with Targetcli -- Python error - F20

[Jerome Martin]

Hi Andy,

Just had a quick look at this...

Was that only an issue with the fb-specific object caching? A quick 
glance at your patch suggests so, but I still do not like the way the 
exception (did not) bubbled up. I'll change that in my next cycle I 
guess, WDYT - do you plan on improving that on your side?

Best,
--
Jerome Martin

On 06/20/2014 08:22 PM, Andy Grover wrote:
>  On 06/20/2014 11:00 AM, Christophe Vu-Brugier wrote:
> > Hi,
> >
> > On Thu, 19 Jun 2014 17:12:51 -0400, deeepdish wrote :
> >> I'm trying to create a block backstore in targetcli on a newly
> >> installed Fedora 20 system.
> >>
> >> I can confirm this is working on another Fedora 20 system (installed
> >> about a month ago), and am wondering if there's an update somewhere
> >> that may be impacting targetcli.
> >>
> >> Here's what I'm attempting:
> >>
> >> [root@bl05ssn09 ~]# lvcreate -n TEST -L 1G data
> >>    Logical volume "TEST" created
> >> [root@bl05ssn09 ~]# targetcli
> >> targetcli shell version 2.1.fb35
> >> Copyright 2011-2013 by Datera, Inc and others.
> >> For help on commands, type 'help'.
> >>
> >> /backstores/block> create name=test dev=/dev/data/TEST
> >> Traceback (most recent call last):
> >>    File "/usr/bin/targetcli", line 100, in <module>
> >>      main()
> >>    File "/usr/bin/targetcli", line 90, in main
> >>      shell.run_interactive()
> >>    File "/usr/lib/python2.7/site-packages/configshell/shell.py", line
> >> 948, in run_interactive
> >>      self._cli_loop()
> >>    File "/usr/lib/python2.7/site-packages/configshell/shell.py", line
> >> 777, in _cli_loop
> >>      self.run_cmdline(cmdline)
> >>    File "/usr/lib/python2.7/site-packages/configshell/shell.py", line
> >> 891, in run_cmdline
> >>      self._execute_command(path, command, pparams, kparams)
> >>    File "/usr/lib/python2.7/site-packages/configshell/shell.py", line
> >> 866, in _execute_command
> >>      result = target.execute_command(command, pparams, kparams)
> >>    File "/usr/lib/python2.7/site-packages/configshell/node.py", line
> >> 1413, in execute_command
> >>      return method(*pparams, **kparams)
> >>    File "/usr/lib/python2.7/site-packages/targetcli/ui_backstore.py",
> >> line 387, in ui_command_create
> >>      so = BlockStorageObject(name, dev, readonly=readonly,
> >> write_back=write_back)
> >>    File "/usr/lib/python2.7/site-packages/rtslib/tcm.py", line 677, in
> >> __init__ raise
> >> TypeError: exceptions must be old-style classes or derived from
> >> BaseException, not NoneType
> >>
> >> [root@bl05ssn09 ~]# targetcli /backstores/block create name=test
> >> dev=/dev/data/TEST
> >> exceptions must be old-style classes or derived from BaseException,
> >> not NoneType
> >> [root@bl05ssn09 ~]#
> >
> > I managed to reproduce your bug on a Fedora 20 with a 3.14 kernel
> > (3.14.6-200.fc20.x86_64). The exception happens in the following part
> > of tcm.py:
> >
> > At line 694 in BlockStorageObject._configure():
> >
> >    if write_back:
> >        self.set_attribute("emulate_write_cache", 1)
> >
> > The set_attribute() method fails because of a permission denied error.
> >
> > As a workaround, you can comment out the two instructions in the
> > following file :
> >
> >    /usr/lib/python2.7/site-packages/rtslib/tcm.py
> >
> > Best regards,
>
>  Thanks for diagnosing the issue!
>
>  This actually is fixed in rtslib-fb git repo, but hasn't been tagged
>  into a release. I'll go ahead and do that.
>
>  Thanks again -- Regards -- Andy
>  --
>  To unsubscribe from this list: send the line "unsubscribe target-devel" in
>  the body of a message to majordomo(a)vger.kernel.org
>  More majordomo info at  http://vger.kernel.org/majordomo-info.html

Issue with Targetcli -- Python error - F20

[Andy Grover]

> >>> line 387, in ui_command_create so =
> BlockStorageObject(name,
> >>> dev, readonly=readonly, write_back=write_back) File
> >>> "/usr/lib/python2.7/site-packages/rtslib/tcm.py", line 677, in
> >>> __init__ raise TypeError: exceptions must be old-style classes
> >>> or derived from BaseException, not NoneType
> >>>
> >>> [root@bl05ssn09 ~]# targetcli /backstores/block create
> >>> name=test dev=/dev/data/TEST exceptions must be old-style
> >>> classes or derived from BaseException, not NoneType 
On 06/23/2014 07:44 AM, Jerome Martin wrote:
>  Hi Andy,
>
>  Just had a quick look at this...
>
>  Was that only an issue with the fb-specific object caching? A quick
>  glance at your patch suggests so, but I still do not like the way the
>  exception (did not) bubbled up. I'll change that in my next cycle I
>  guess, WDYT - do you plan on improving that on your side? 
The cache fix was unrelated.

I agree, even though removing the set_attribute() resolved the issue, 
the bug report raised questions about the exception handling. The syntax

<abc>

try:
     <defgh>
except:
     <abc cleanup>
     raise

should be fine, and should not cause that error.

Regards -- Andy

Issue with Targetcli -- Python error - F20

[Jerome Martin]

On 06/23/2014 07:06 PM, Andy Grover wrote:
>  The cache fix was unrelated. 
<nod>, saw that now.

>  I agree, even though removing the set_attribute() resolved the issue,
>  the bug report raised questions about the exception handling. The syntax
>
>  <abc>
>
>  try:
>       <defgh>
>  except:
>       <abc cleanup>
>       raise
>
>  should be fine, and should not cause that error. 
The only way this happens is if <defgh> somehow raises None. I imagine 
<abc cleanup> could also manipulate the last exception traceback, but I 
doubt this happens. I'll dig into it on my next cycle.

Regards,
--
Jerome