Property filesystem_limit does not work as documented

[spaghettopazzia]

System information

Type	Version/Name
Distribution Name	Debian
Distribution Version	Jessie
Linux Kernel	3.16.0-4-amd64
Architecture	amd64
ZFS Version	0.8.0-rc2
SPL Version	0.8.0-rc2

Describe the problem you're observing

According to the zfs manual filesystem_limit does not apply to users allowed to change the property:

filesystem_limit=count|none
Limits the number of filesystems and volumes that can exist under
this point in the dataset tree. The limit is not enforced if the user is allowed to change the limit. Setting a filesystem_limit to on a descendent of a filesystem that already has a filesystem_limit does not override the ancestor's filesystem_limit, but rather imposes an additional limit. This feature must be enabled to be used (see zpool-features(5)).

I find this information to be wrong.

Describe how to reproduce the problem

root@nymeria:~# zfs create -o filesystem_limit=3 rpool/limited
root@nymeria:~# zfs create rpool/limited/fs1
root@nymeria:~# zfs create rpool/limited/fs2
root@nymeria:~# zfs create rpool/limited/fs3
root@nymeria:~# zfs create rpool/limited/fs4
cannot create 'rpool/limited/fs4': out of space
root@nymeria:~# zfs set filesystem_limit=4 rpool/limited
root@nymeria:~# zfs create rpool/limited/fs4
root@nymeria:~# zfs create rpool/limited/fs5
cannot create 'rpool/limited/fs5': out of space

Include any warning/errors/backtraces from the system logs

None

[devZer0]

for me it looks like it was fixed !?

close?

[loli10K]

This is not fixed:

root@linux:~# cat /sys/module/zfs/version
0.8.0-282_gafc8f0a6f
root@linux:~# POOLNAME='testpool'
root@linux:~# TMPDIR='/var/tmp'
root@linux:~# mountpoint -q $TMPDIR || mount -t tmpfs tmpfs $TMPDIR
root@linux:~# zpool destroy -f $POOLNAME
root@linux:~# rm -f $TMPDIR/zpool.dat
root@linux:~# truncate -s 128m $TMPDIR/zpool.dat
root@linux:~# zpool create -O mountpoint=none $POOLNAME $TMPDIR/zpool.dat
root@linux:~# zfs create -o filesystem_limit=3 $POOLNAME/limited
root@linux:~# zfs create $POOLNAME/limited/fs1
root@linux:~# zfs create $POOLNAME/limited/fs2
root@linux:~# zfs create $POOLNAME/limited/fs3
root@linux:~# zfs create $POOLNAME/limited/fs4
cannot create 'testpool/limited/fs4': out of space
root@linux:~# zfs set filesystem_limit=4 $POOLNAME/limited
root@linux:~# zfs create $POOLNAME/limited/fs5
root@linux:~# zfs create $POOLNAME/limited/fs6
cannot create 'testpool/limited/fs6': out of space

[ghost]

The test for this is also wrong.