cd /.zfs/snapshot hangs (tmux put to uninterruptible sleep)

Matthew Seaman matthew at FreeBSD.org
Sun Oct 25 11:55:03 UTC 2015


On 25/10/2015 11:49, Niklaas Baudet von Gersdorff wrote:
> Do I understand correctly (from the link above) that the maximal
> length of a name is 88? See:
> 
>> > /* * filesystem statistics */ [...] #define MNAMELEN        88
>> > /* size of on/from name bufs */ [...] struct statfs { [...] char
>> > f_mntfromname[MNAMELEN];/* mounted filesystem */ char
>> > f_mntonname[MNAMELEN];	/* directory on which mounted */ };

> Isn't this a bug? Shouldn't the request just fail instead of putting
> the process into D?

I am not sure that the failed automount is the immediate cause of the
processes getting wedged -- that is secondary thing; a consequence of
anything trying to access the failed automount later.  Not that it makes
a whole lot of difference in the  end.

>> > When you run into the limit, it is not that the snapshot automount
>> > simply fails: it leaves the system in a less than ideal state, and
>> > you have to force unmount the path where the the snapshot would
>> > have been mounted.
>> > 
>> > umount -f /.zfs/snapshot/some-directory

> Unfortunately, `mount` doesn't reveal any mounts in /.zfs .

Yes, I really should put together a repeatable test case and write a bug
report.

	Cheers,

	Matthew


-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 957 bytes
Desc: OpenPGP digital signature
URL: <http://lists.freebsd.org/pipermail/freebsd-questions/attachments/20151025/c54b79b5/attachment.bin>


More information about the freebsd-questions mailing list