[LTP] [PATCH] commands/mkswap01: Update wait_for_file function

[Shuang Qiu <shuang.qiu@oracle.com>]

On 02/04/2016 09:17 PM, Cyril Hrubis wrote:
> Hi!
>>> Does actually the swapon in the verify function work? Since as far as I
>>> can tell it actually opens the symlink in question in order to get the
>>> swap device.
>>>
>>> Have you tried stracing it in case that the code waiting for the device
>>> timeouted?
>> I tried it with UEK.Sometimes waiting for device timeout but swapon
>> works,i.e.:
>>
>> ...
>> ...
>>
>> mkswap01 6 TINFO : Waiting for /dev/disk/by-label/ltp_testswap to appear
>> mkswap01 6 TINFO : Waiting for /dev/disk/by-label/ltp_testswap to appear
>> mkswap01 6 TINFO : Waiting for /dev/disk/by-label/ltp_testswap to appear
>> mkswap01 6 TWARN : The file /dev/disk/by-label/ltp_testswap haven't appeared
>> mkswap01 6 TPASS : 'mkswap -L ltp_testswap /dev/sda7 ' passed.
>> ...
> That looks strange to me. Since if I strace 'swapon -L ltp_testswap' I got:
>
> ...
> stat("/dev/disk/by-label/ltp_testswap", 0x7ffef8293800) = -1 ENOENT (No such file or directory)
> ...
>
> Then it proceeds to exit with error. So I'm geniuely confused.
>
> Hmm but looking at blkid man page, it says that udev symlinks may depend
> on settings in /etc/blkid.conf. That may be the difference after all.
>
> Looking at the manual page doing 'blkid -L ltp_testswap' and 'blkid -U
> $UUID' should be the only correct solution. Does that work for you?
Yes.
But it does not support blkid -L/-U with lower version of blkid 
util(such like in RHEL5.11).
So I use "-t" option to search the label and UUID instead in the patch.

Thanks
Shuang
>