Re: [Libguestfs] guestunmount issues
Hi,
On Monday 23 November 2015 18:29:50 Maxim Perevedentsev wrote:
1) guestunmount never returns 3 (not mounted) - i guess it's a
bug at
guestunmount.c:223
Indeed, thanks for the notice -- just send a patch for it.
2) I don't know whether it's a bug in guestunmount or
fusermount, but on
my machine while executing
> guestmount
> guestunmount
> guestunmount
on second "guestunmount" I get
"guestunmount: failed to unmount {...}: fusermount: failed to unmount
{...}: Invalid argument"
while, according to guestunmount.c, guestunmount should return something
like
"entry for {} not found"
Most probably it has to do with the (3) below: fusermount just reports
the EINVAL got from umount while trying to unmount an not-mounted
directory.
3)
> fusermount -u {}
gives me "Invalid argument" as well, while
> umount {}
handles this error successfully and returns "not mounted".
(strace logs attached)
Well, umount still returns 1, so
In any case, both fail due to the mount point not being actually
mounted; the difference is that umount takes the EINVAL from umount2
(which calls the umount Linux syscall) as an indication the directory
is not a mount point, while fusermount just reports the failure as it
is.
I'd like someone to compare results with mine, and, possibly,
give me
some explanations about why it's going like this and how to distinguish
non-mounted mountpoints from busy ones (I guess I'll have to parse
umount {} output).
Unfortunately it does not seem to be possible to do that, just by
checking the return values of the tools. I guess you might want to ask
fuse and util-linux people to improve the return values, although that
might break user code...
Another alternative may be writing C code doing the umount, but that
would imply rewrite part of the logic...
--
Pino Toscano
Attachments:
- signature.asc (application/pgp-signature — 819 bytes)