Re: mount weirdness

["Thomas Schmitt" <scdbackup@gmx.net>]

Hi,

David Wright wrote:
> it appears that any subsequent mount commands have to
> agree explicitly with the earlier choice. Are there other, similar
> factors involved in the OP's case…

Ah yes.

I was similarly confused by my system's behavior on double mount
and the fact that i remember to have needed mount -o loop for mounting
two different ISO 9660 sessions on the same DVD.

It seems that identical multi-mounts actually work like links to the
same filesystem:

  # mount /dev/sdc2 /mnt/fat
  # mount /dev/sdc2 /mnt/fat2
  # echo hallo >/mnt/fat/x
  # cat /mnt/fat/x
  hallo
  # cat /mnt/fat2/x
  hallo


Greg Wooledge wrote:
> The disappearance of one of the mounts from "df" output also tells me
> that, if nothing else, "df" is not prepared to handle this situation.

Or it avoids intentionally to represent one mounted filesystem as two.
The code starting at
  https://sources.debian.org/src/coreutils/8.30-3/src/df.c/#L688
looks like considerations for possibly doing one of:
  /* Discard mount entry for existing device.  */
  /* Discard mount entry currently being processed.  */

---------------------------------------------------------------------

But again, this is a deviation from the problem.

Why does mount fail silently ?
Why is bad luck attached only to the mount directory path /wa1 ?

(Is the problem bound to mount(8) or does it sit in mount(2) ?)


Have a nice day :)

Thomas