[gentoo-user] Re: Strange new behavior from the "mount" command

[walt <w41ter@gmail.com>]

On 04/18/2015 05:33 PM, Fernando Rodriguez wrote:
> On Saturday, April 18, 2015 3:59:15 PM walt wrote:
>>
>> execve("/bin/mount", ["mount"], [/* 61 vars */]) = 0
>>
>> That number 61 on the 'bad' machine is 48, though, and I don't know where
>> that odd-looking string of characters is generated or what it means. To me
>> it looks like a comment in a file of 'c' code.
>>
>> Still stumped :(
> 
> That would be the number of environment variables passed to execve. strace is 
> just trying not to be too noisy.
> 
> 
> Are there any differences in the options used in fstab between both machines, 
> Especially the auto or noauto options or if one of them is using labels. The 
> mount(8) man page may have more hints.

As a quick-and-dirty way of testing your idea I moved /etc/fstab out of the way.

I was surprised to learn that "mount" doesn't care about fstab, and doesn't even
bother to look for it (when invoked with no arguments).

Using strace I examined the list of files opened by "mount" on both machines and
discovered that the "bad" machine reads the same 8 files as the "good" machine,
but then proceeds to read /etc/blkid.conf (I don't have that file on either machine)
and then /proc/cmdline.  (And then proceeds to read all the partition tables, etc)

So, what kind of process needs those two files to do its job?  I have no idea, but
I'm hoping that some of you smart people out there may know.