[PATCH] lvcreate: support --force option

[PATCH] lvcreate: support --force option

[Lidong Zhong]

The option is supported in the logic of lvcreate but is omitted in
commands.h.

Signed-off-by: Lidong Zhong <lzhong@suse.com>
---
 WHATS_NEW        | 1 +
 tools/commands.h | 4 +++-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/WHATS_NEW b/WHATS_NEW
index 9af759e..274af43 100644
--- a/WHATS_NEW
+++ b/WHATS_NEW
@@ -1,5 +1,6 @@
 Version 2.02.133 - 
 ======================================
+  Make lvcreate support --force option
   Cleanup vgimportclone script and remove dependency on awk, grep, cut and tr.
   Add vg_missing_pv_count report field to report number of missing PVs in a VG.
   Properly identify internal LV holding sanlock locks within lv_role field.
diff --git a/tools/commands.h b/tools/commands.h
index 92d13fd..7695498 100644
--- a/tools/commands.h
+++ b/tools/commands.h
@@ -311,6 +311,7 @@ xx(lvcreate,
    "\t[-C|--contiguous {y|n}]\n"
    "\t[--commandprofile ProfileName]\n"
    "\t[-d|--debug]\n"
+   "\t[-f|--force]\n"
    "\t[-h|-?|--help]\n"
    "\t[--errorwhenfull {y|n}]\n"
    "\t[--ignoremonitoring]\n"
@@ -360,6 +361,7 @@ xx(lvcreate,
    "\t[--commandprofile ProfileName]\n"
    "\t[-d|--debug]\n"
    "\t[--discards {ignore|nopassdown|passdown}]\n"
+   "\t[-f|--force]\n"
    "\t[-h|-?|--help]\n"
    "\t[--ignoremonitoring]\n"
    "\t[--monitor {y|n}]\n"
@@ -386,7 +388,7 @@ xx(lvcreate,
    addtag_ARG, alloc_ARG, autobackup_ARG, activate_ARG, available_ARG,
    cache_ARG, cachemode_ARG, cachepool_ARG, cachepolicy_ARG, cachesettings_ARG,
    chunksize_ARG, contiguous_ARG, corelog_ARG, discards_ARG, errorwhenfull_ARG,
-   extents_ARG, ignoreactivationskip_ARG, ignoremonitoring_ARG, major_ARG,
+   extents_ARG, force_ARG, ignoreactivationskip_ARG, ignoremonitoring_ARG, major_ARG,
    metadataprofile_ARG, minor_ARG, mirrorlog_ARG, mirrors_ARG, monitor_ARG,
    minrecoveryrate_ARG, maxrecoveryrate_ARG, name_ARG, nosync_ARG,
    noudevsync_ARG, permission_ARG, persistent_ARG,
-- 
1.8.1.4

[PATCH] lvcreate: support --force option

[Zdenek Kabelac]

Dne 10.10.2015 v 12:39 Lidong Zhong napsal(a):
> The option is supported in the logic of lvcreate but is omitted in
> commands.h.
>

Nope - it's not intended to be unsupported so far.

We do support --yes  to overcome prompts.

Normally --force is meant to be used on paths to proceed with
i.e. lvremove, lvconvert

Do you have any case in mind where '--force' with lvcreate would have make any 
sense ?
IMHO creating something with --force looks to me like crazy idea to start with 
- but maybe there is some use-case I'm missing ?

Zdenek

[PATCH] lvcreate: support --force option

[Lidong Zhong]

Hi Zdenek,

Thanks for your reply.

>>> On 10/10/2015 at 09:17 PM, in message <56190FE5.1030900@redhat.com>, Zdenek
Kabelac <zkabelac@redhat.com> wrote: 
> Dne 10.10.2015 v 12:39 Lidong Zhong napsal(a): 
> > The option is supported in the logic of lvcreate but is omitted in 
> > commands.h. 
> > 
>  
> Nope - it's not intended to be unsupported so far. 
>  
> We do support --yes  to overcome prompts. 
>  
> Normally --force is meant to be used on paths to proceed with 
> i.e. lvremove, lvconvert 
>  
> Do you have any case in mind where '--force' with lvcreate would have make any  
>  
> sense ? 

Not really. I met this problem when I was using lvcreate with the --wipesignature option. 
--yes works for me. But I also found that --force should also work when I read the source.
However, it reports -f/--force is an invalid option for lvcreate.


> IMHO creating something with --force looks to me like crazy idea to start with  
>  
> - but maybe there is some use-case I'm missing ? 
>  

Currently there is no introduction to --yes in the manpage of lvcreate. How about adding it to
the manpage?

Regards,
Lidong

> Zdenek 
>  
> -- 
> lvm-devel mailing list 
> lvm-devel at redhat.com 
> https://www.redhat.com/mailman/listinfo/lvm-devel 
>  
>  

[PATCH] lvcreate: support --force option

[Zdenek Kabelac]

Dne 12.10.2015 v 04:26 Lidong Zhong napsal(a):
> Hi Zdenek,
>
> Thanks for your reply.
>
>>>> On 10/10/2015 at 09:17 PM, in message <56190FE5.1030900@redhat.com>, Zdenek
> Kabelac <zkabelac@redhat.com> wrote:
>> Dne 10.10.2015 v 12:39 Lidong Zhong napsal(a):
>>> The option is supported in the logic of lvcreate but is omitted in
>>> commands.h.
>>>
>>
>> Nope - it's not intended to be unsupported so far.
>>
>> We do support --yes  to overcome prompts.
>>
>> Normally --force is meant to be used on paths to proceed with
>> i.e. lvremove, lvconvert
>>
>> Do you have any case in mind where '--force' with lvcreate would have make any
>>
>> sense ?
>
> Not really. I met this problem when I was using lvcreate with the --wipesignature option.
> --yes works for me. But I also found that --force should also work when I read the source.
> However, it reports -f/--force is an invalid option for lvcreate.

Yep - and so far it should stay that way -  --force has special meaning for 
being quite unsafe operation.

>
>> IMHO creating something with --force looks to me like crazy idea to start with
>>
>> - but maybe there is some use-case I'm missing ?
>>
>
> Currently there is no introduction to --yes in the manpage of lvcreate. How about adding it to
> the manpage?

Every lvm man page references 'man lvm' as the source of description for all 
'commonly' accepted options (like --yes).

One day we may switch to 'generated' man pages - where very man page would 
have all options described - but I guess this 'day' is still pretty far away ;)

Regards

Zdenek

[PATCH] lvcreate: support --force option

[Lidong Zhong]

Hi Zdenek,

>>> On 10/12/2015 at 05:02 PM, in message <561B7728.5010804@redhat.com>, Zdenek
Kabelac <zkabelac@redhat.com> wrote: 
> Dne 12.10.2015 v 04:26 Lidong Zhong napsal(a): 
> > Hi Zdenek, 
> > 
> > Thanks for your reply. 
> > 
> >>>> On 10/10/2015 at 09:17 PM, in message <56190FE5.1030900@redhat.com>, Zdenek 
> > Kabelac <zkabelac@redhat.com> wrote: 
> >> Dne 10.10.2015 v 12:39 Lidong Zhong napsal(a): 
> >>> The option is supported in the logic of lvcreate but is omitted in 
> >>> commands.h. 
> >>> 
> >> 
> >> Nope - it's not intended to be unsupported so far. 
> >> 
> >> We do support --yes  to overcome prompts. 
> >> 
> >> Normally --force is meant to be used on paths to proceed with 
> >> i.e. lvremove, lvconvert 
> >> 
> >> Do you have any case in mind where '--force' with lvcreate would have make  
> any 
> >> 
> >> sense ? 
> > 
> > Not really. I met this problem when I was using lvcreate with the  
> --wipesignature option. 

If we set the --wipesignature to y while creating an lv, there will be a prompt for confirming 
in current code. Doesn't it make more sense that there shouldn't be the prompt? since we
definitely want to remove the signature by setting this option.
Some options such as "--zero=y" don't give prompt, why it is different? 
Please give your opinion.

Regards,
Lidong

> > --yes works for me. But I also found that --force should also work when I read  
> the source. 
> > However, it reports -f/--force is an invalid option for lvcreate. 
>  
> Yep - and so far it should stay that way -  --force has special meaning for  
> being quite unsafe operation. 
>  
> > 
> >> IMHO creating something with --force looks to me like crazy idea to start  
> with 
> >> 
> >> - but maybe there is some use-case I'm missing ? 
> >> 
> > 
> > Currently there is no introduction to --yes in the manpage of lvcreate. How  
> about adding it to 
> > the manpage? 
>  
> Every lvm man page references 'man lvm' as the source of description for all  
>  
> 'commonly' accepted options (like --yes). 
>  
> One day we may switch to 'generated' man pages - where very man page would  
> have all options described - but I guess this 'day' is still pretty far away  
> ;) 
>  
> Regards 
>  
> Zdenek 
>  
>  
> -- 
> lvm-devel mailing list 
> lvm-devel at redhat.com 
> https://www.redhat.com/mailman/listinfo/lvm-devel 
>  
>  

[PATCH] lvcreate: support --force option

[Zdenek Kabelac]

Dne 26.10.2015 v 11:07 Lidong Zhong napsal(a):
> Hi Zdenek,
>
>>>> On 10/12/2015 at 05:02 PM, in message <561B7728.5010804@redhat.com>, Zdenek
> Kabelac <zkabelac@redhat.com> wrote:
>> Dne 12.10.2015 v 04:26 Lidong Zhong napsal(a):
>>> Hi Zdenek,
>>>
>>> Thanks for your reply.
>>>
>>>>>> On 10/10/2015 at 09:17 PM, in message <56190FE5.1030900@redhat.com>, Zdenek
>>> Kabelac <zkabelac@redhat.com> wrote:
>>>> Dne 10.10.2015 v 12:39 Lidong Zhong napsal(a):
>>>>> The option is supported in the logic of lvcreate but is omitted in
>>>>> commands.h.
>>>>>
>>>>
>>>> Nope - it's not intended to be unsupported so far.
>>>>
>>>> We do support --yes  to overcome prompts.
>>>>
>>>> Normally --force is meant to be used on paths to proceed with
>>>> i.e. lvremove, lvconvert
>>>>
>>>> Do you have any case in mind where '--force' with lvcreate would have make
>> any
>>>>
>>>> sense ?
>>>
>>> Not really. I met this problem when I was using lvcreate with the
>> --wipesignature option.
>
> If we set the --wipesignature to y while creating an lv, there will be a prompt for confirming
> in current code. Doesn't it make more sense that there shouldn't be the prompt? since we
> definitely want to remove the signature by setting this option.
> Some options such as "--zero=y" don't give prompt, why it is different?
> Please give your opinion.
>


Hi


Here is explanation.

'zero' is unconditional and does not detect any signature - so it has nothing 
to prompt about - it zeroes first 4K as that's what user asked for.

New 'wipesignature' first detects signature and asks if you want to wipe.
That's the API (and it's very similar to e.g. mkfs)

If lvm2 knows its overwriting something it prompts - that's the rule.

If you are going to take a 'risk' for no prompting - use  '--yes'

lvm2 is possibly missing couple prompts - so you could possibly open BZ for 
the case we convert/overwrite something without prompting first.

But existing prompts will remain as they are as they are correct.

Regards

Zdenek

[PATCH] lvcreate: support --force option

[Lidong Zhong]

Hello Zdenek,

Thanks for your detailed explanation. I am clear that it's a rule that it prompt every time 
when lvm2 overwrites something.
Once there is a exception in future, I surely will notify the upstream.
Thanks again.

Regards,
Lidong

>>> On 10/26/2015 at 09:42 PM, in message <562E2DC0.1020002@redhat.com>, Zdenek
Kabelac <zkabelac@redhat.com> wrote: 
> Dne 26.10.2015 v 11:07 Lidong Zhong napsal(a): 
> > Hi Zdenek, 
> > 
> >>>> On 10/12/2015 at 05:02 PM, in message <561B7728.5010804@redhat.com>, Zdenek 
> > Kabelac <zkabelac@redhat.com> wrote: 
> >> Dne 12.10.2015 v 04:26 Lidong Zhong napsal(a): 
> >>> Hi Zdenek, 
> >>> 
> >>> Thanks for your reply. 
> >>> 
> >>>>>> On 10/10/2015 at 09:17 PM, in message <56190FE5.1030900@redhat.com>, Zdenek 
> >>> Kabelac <zkabelac@redhat.com> wrote: 
> >>>> Dne 10.10.2015 v 12:39 Lidong Zhong napsal(a): 
> >>>>> The option is supported in the logic of lvcreate but is omitted in 
> >>>>> commands.h. 
> >>>>> 
> >>>> 
> >>>> Nope - it's not intended to be unsupported so far. 
> >>>> 
> >>>> We do support --yes  to overcome prompts. 
> >>>> 
> >>>> Normally --force is meant to be used on paths to proceed with 
> >>>> i.e. lvremove, lvconvert 
> >>>> 
> >>>> Do you have any case in mind where '--force' with lvcreate would have make 
> >> any 
> >>>> 
> >>>> sense ? 
> >>> 
> >>> Not really. I met this problem when I was using lvcreate with the 
> >> --wipesignature option. 
> > 
> > If we set the --wipesignature to y while creating an lv, there will be a  
> prompt for confirming 
> > in current code. Doesn't it make more sense that there shouldn't be the  
> prompt? since we 
> > definitely want to remove the signature by setting this option. 
> > Some options such as "--zero=y" don't give prompt, why it is different? 
> > Please give your opinion. 
> > 
>  
>  
> Hi 
>  
>  
> Here is explanation. 
>  
> 'zero' is unconditional and does not detect any signature - so it has nothing  
>  
> to prompt about - it zeroes first 4K as that's what user asked for. 
>  
> New 'wipesignature' first detects signature and asks if you want to wipe. 
> That's the API (and it's very similar to e.g. mkfs) 
>  
> If lvm2 knows its overwriting something it prompts - that's the rule. 
>  
> If you are going to take a 'risk' for no prompting - use  '--yes' 
>  
> lvm2 is possibly missing couple prompts - so you could possibly open BZ for  
> the case we convert/overwrite something without prompting first. 
>  
> But existing prompts will remain as they are as they are correct. 
>  
> Regards 
>  
> Zdenek 
>  
>  
>