Re: [Qemu-block] [PATCH for-4.0?] iotest: Fix 241 to run in generic directory

[Vladimir Sementsov-Ogievskiy]

11.04.2019 17:47, Eric Blake wrote:
> On 4/11/19 2:57 AM, Vladimir Sementsov-Ogievskiy wrote:
>> 10.04.2019 23:42, Eric Blake wrote:
>>> Filter the qemu-nbd server output to get rid of a direct reference
>>> to my build directory.
>>>
>>> Fixes: e9dce9cb
>>> Reported-by: Max Reitz <address@hidden>
>>> Signed-off-by: Eric Blake <address@hidden>
>>> ---
>>>
>>> Not worth -rc4 on its own, but if something else pops up that requires
>>> another spin, I plan on a pull request for this one. Otherwise it
>>> slips to 4.1, and 4.0 just has a broken iotest.
>>>
> 
>>> @@ -69,12 +70,13 @@ echo
>>>
>>>    # Intentionally omit '-f' to force image probing, which in turn forces
>>>    # sector alignment, here at the server.
>>> -nbd_server_start_unix_socket "$TEST_IMG_FILE"
>>> +nbd_server_start_unix_socket "$TEST_IMG_FILE" 2> "$TEST_DIR/server.log"
>>>
> 
>>>    1 KiB (0x400) bytes     allocated at offset 0 bytes (0x0)
>>> +WARNING: Image format was not specified for 'TEST_DIR/t.raw' and probing 
>>> guessed raw.
>>> +         Automatically detecting the format is dangerous for raw images, 
>>> write operations on block 0 will be restricted.
>>> +         Specify the 'raw' format explicitly to remove the restrictions.
>>
>> May be, just add -f raw to nbd server, to make this message disappear? And 
>> than, don't do any redirections, as if there
>> will be failed unfiltered output it is OK?
> 
> No. See the comment in the test - it is intentional that we are omitting
> -f, in two different places, in order to get three test scenarios:
> 
> normal: server '-f raw' 1-byte align, client '-f raw' 1-byte align
> server-constrained: server omit for 512-byte align, client '-f raw'
> obeys server align
> client-constrained: server '-f raw' 1-byte align, client omit for
> intentional 512-byte align
> 
> in order to show both that the server with forced alignment is able to
> round requests correctly before sending to the client, and to show that
> the client with forced alignment is able to round requests correctly in
> spite of the server sending answers narrower than the client wants.
> 
> In 4.1, when Max's filter handling patches land, it will be possible to
> use the blkdebug driver to force alignment instead of omitting '-f raw';
> at which point we can take away the server.log file. But until the
> filter handling patches land, any use of blkdebug causes odd test
> misbehaviors because not everything in the block layer properly sees
> through filter nodes.
> 

Understand now, thanks.

Reviewed-by: Vladimir Sementsov-Ogievskiy <address@hidden>

-- 
Best regards,
Vladimir