Date: Thu, 9 Jun 2016 14:24:10 +0200 From: richard bader <richard@bader-muenchen.de> To: Konstantin Belousov <kostikbel@gmail.com> Cc: richard@bader-muenchen.de, Peter Holm <peter@holm.cc>, freebsd-fs@freebsd.org Subject: Re: disk space not freed when deleting files in null_mounted filesystem Message-ID: <833c60c3-7d0f-4177-a7cb-2af2297656d5@bader-muenchen.de> In-Reply-To: <20160609121705.GB38613@kib.kiev.ua> References: <2e11d942-0856-7ce4-56ef-3774046f8df8@bader-muenchen.de> <20160609112703.GA42321@x2.osted.lan> <92c2f5f8-a5fc-4947-1e65-252543a2569e@bader-muenchen.de> <20160609121126.GA46828@x2.osted.lan> <20160609121705.GB38613@kib.kiev.ua>
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Am 09.06.2016 um 14:17 schrieb Konstantin Belousov:
> On Thu, Jun 09, 2016 at 02:11:26PM +0200, Peter Holm wrote:
>> On Thu, Jun 09, 2016 at 01:39:45PM +0200, richard bader wrote:
>>> Am 09.06.2016 um 13:27 schrieb Peter Holm:
>>>> On Thu, Jun 09, 2016 at 12:13:08PM +0200, richard bader wrote:
>>>>> Hello,
>>>>>
>>>>> i've a filesystem mounted with mount_nullfs.
>>>>> When i delete a large file in this filesystem, the space on the disk is
>>>>> not freed.
>>>>> The space becomes freed when i unmount the filesystem.
>>>>>
>>>>>
>>>>> to reproduce this:
>>>>>
>>>>> root@main2:/tmp # mkdir lnk src
>>>>> root@main2:/tmp # mount_nullfs src lnk
>>>>> root@main2:/tmp # mount | grep lnk
>>>>> /tmp/src on /tmp/lnk (nullfs, local)
>>>>> root@main2:/tmp # df -h .
>>>>> Filesystem Size Used Avail Capacity Mounted on
>>>>> /dev/ada0p2 58G 40G 13G 75% /
>>>>> root@main2:/tmp # dd if=/dev/zero of=lnk/foo bs=1G count=3
>>>>> 3+0 records in
>>>>> 3+0 records out
>>>>> 3221225472 bytes transferred in 7.856793 secs (409992411 bytes/sec)
>>>>> root@main2:/tmp # df -h .
>>>>> Filesystem Size Used Avail Capacity Mounted on
>>>>> /dev/ada0p2 58G 43G 10G 80% /
>>>>> root@main2:/tmp # rm lnk/foo
>>>>> root@main2:/tmp # df -h .
>>>>> Filesystem Size Used Avail Capacity Mounted on
>>>>> /dev/ada0p2 58G 43G 10G 80% /
>>>>> root@main2:/tmp # umount /tmp/lnk
>>>>> root@main2:/tmp # df -h .
>>>>> Filesystem Size Used Avail Capacity Mounted on
>>>>> /dev/ada0p2 58G 40G 13G 75% /
>>>>>
>>>>>
>>>>> my system:
>>>>>
>>>>> root@main2:/tmp # uname -a
>>>>> FreeBSD main2.bader.loc 10.2-RELEASE-p18 FreeBSD 10.2-RELEASE-p18 #8
>>>>> r301112: Wed Jun 1 11:08:24 CEST 2016
>>>>> root@main2.bader.loc:/usr/obj/usr/src/sys/MYKERNEL amd64
>>>>>
>>>>> are the any options for mount_nullfs ?
>>>>>
>>>>> best regards
>>>>>
>>>>> richard
>>>>>
>>>> Hello Richard,
>>>>
>>>> I wonder which file system you are using?
>>>> Here's what happens with UFS and current from today:
>>>>
>>>> $ cat -n richard.sh
>>>> 1 #!/bin/sh
>>>> 2
>>>> 3 uname -a
>>>> 4 mount | grep `df -h /tmp | tail -1 | awk '{print $1}'`
>>>> 5
>>>> 6 cd /tmp
>>>> 7 rm -rf lnk src
>>>> 8 mkdir lnk src
>>>> 9 mount_nullfs src lnk
>>>> 10 mount | grep lnk
>>>> 11 df -h .
>>>> 12 dd if=/dev/zero of=lnk/foo bs=1G count=3
>>>> 13 df -h .
>>>> 14 rm lnk/foo
>>>> 15 df -h .
>>>> 16 umount /tmp/lnk
>>>> 17 df -h .
>>>> $ ./richard.sh
>>>> FreeBSD t2.osted.lan 11.0-ALPHA2 FreeBSD 11.0-ALPHA2 #0 r301722: Thu Jun 9 12:09:39 CEST 2016 pho@t2.osted.lan:/usr/src/sys/amd64/compile/PHO amd64
>>>> /dev/da0p3 on /tmp (ufs, NFS exported, local, soft-updates)
>>>> /tmp/src on /tmp/lnk (nullfs, local)
>>>> Filesystem Size Used Avail Capacity Mounted on
>>>> /dev/da0p3 97G 1,6G 87G 2% /tmp
>>>> 3+0 records in
>>>> 3+0 records out
>>>> 3221225472 bytes transferred in 47.658947 secs (67589102 bytes/sec)
>>>> Filesystem Size Used Avail Capacity Mounted on
>>>> /dev/da0p3 97G 4,6G 84G 5% /tmp
>>>> Filesystem Size Used Avail Capacity Mounted on
>>>> /dev/da0p3 97G 1,6G 87G 2% /tmp
>>>> Filesystem Size Used Avail Capacity Mounted on
>>>> /dev/da0p3 97G 1,6G 87G 2% /tmp
>>>> $
>>>>
>>>> - Peter
>>> i'm also using ufs.
>>>
>>> root@main2:/tmp # ./richard.sh
>>> FreeBSD main2.bader.loc 10.2-RELEASE-p18 FreeBSD 10.2-RELEASE-p18 #8
>>> r301112: Wed Jun 1 11:08:24 CEST 2016
>>> root@main2.bader.loc:/usr/obj/usr/src/sys/MYKERNEL amd64
>>> /dev/ada0p2 on / (ufs, local, journaled soft-updates)
>>> /tmp/src on /tmp/lnk (nullfs, local)
>>> Filesystem Size Used Avail Capacity Mounted on
>>> /dev/ada0p2 58G 40G 13G 75% /
>>> 3+0 records in
>>> 3+0 records out
>>> 3221225472 bytes transferred in 8.679717 secs (371121023 bytes/sec)
>>> Filesystem Size Used Avail Capacity Mounted on
>>> /dev/ada0p2 58G 43G 10G 80% /
>>> Filesystem Size Used Avail Capacity Mounted on
>>> /dev/ada0p2 58G 43G 10G 80% /
>>> Filesystem Size Used Avail Capacity Mounted on
>>> /dev/ada0p2 58G 40G 13G 75% /
>>>
>> Hmm. I tried again on SU+J but I still do not see any problems on
>> HEAD. I'll build r301112 and see what happens.
> There were several bugs fixed since 10.2 in nullfs. Use -o nocache
> to disable nullfs vnode caching, which most likely fix it for 10.2.
> _______________________________________________
Thanks,
with 'mount_nullfs -o nocache src lnk' it works as expected
- richard
--
Dipl.Ing.Bader Richard GmbH, Helferichstrasse 32, 80999 Muenchen
Tel.: +49 89 892205 31
Fax.: +49 89 892205 33
http://www.bader-muenchen.de
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