Re: Duplicate network filesystems

["Aurélien Aptel" <aaptel@suse.com>]

NeilBrown <neilb@suse.com> writes:
>> mount //foo /mnt -o A
>> mount //foo /mnt -o B # different options
>>
>> Since the SB are different it works, fine.
>>
>> But mounting a 3rd time with options A succeeds, where from a user POV I
>> would have expected to fail.
>
> Why?

Because it's already mounted.

>> mount //foo /mnt -o A
>> mount //foo /mnt -o B
>> mount //foo /mnt -o A
>> # ok => what?
>>
>> Shouldn't we check the stack of filesystems mounted at the path instead of
>> just the last one?
>
> Why?
>
> I think that the main reason that -EBUSY is important is that people
> often run "mount -a" and don't expect filesystems that are already
> mounted to be mounted again.  The current behaviour achieves that.

A is already mounted and mouting again succeeds. The current behaviour is
different from what you described. This is exactly what I was saying
earlier "from a user POV".

Side-note:
mount from coreutils has some logic to deal with -a and network
filesystems, because there are some issues with the default behaviour. I
can't recall the details about that, would have to look at the code
again.

Cheers,
-- 
Aurélien Aptel / SUSE Labs Samba Team
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