* 3.10.10: quota problems
@ 2013-10-11 23:25 Carlos Carvalho
2013-10-15 15:53 ` Jan Kara
0 siblings, 1 reply; 5+ messages in thread
From: Carlos Carvalho @ 2013-10-11 23:25 UTC (permalink / raw)
To: linux-ext4
There are two problems. First, on a new filesystem with
tune2fs -Q usrquota and grpquota was working fine until a power
failure switched the machine off. On reboot all files seem normal
but quota -v showed no limits neither usage...
I ran fsck and it said the fs was clean. Then I ran fsck -f and
Pass 5: Checking group summary information
[QUOTA WARNING] Usage inconsistent for ID 577:actual (12847804416, 308767) != expected (12868194304, 308543)
[QUOTA WARNING] Usage inconsistent for ID 541:actual (186360393728, 11089) != expected (186340204544, 11085)
... etc until
Update quota info for quota type 0<y>? yes
then some more of
[QUOTA WARNING] Usage inconsistent for ID 500:actual (192918523904, 20725) != expected (192897576960, 20671)
until
Update quota info for quota type 1<y>? yes
/dev/md3: ***** FILE SYSTEM WAS MODIFIED *****
After remounting and running quota on usage for some users were back
but not limits. For other users even usage is lost.
This is with 3.10.10, e2fsprogs 1.42.8 (Debian) and mount options
rw,nosuid,nodev,commit=30,stripe=768,data=ordered,inode_readahead_blks=64
This was the first unclean shutdown of this machine after more than 6
months of usage. The new quota method looks fragile... Is there
something I can do get limits and usage back?
--------------------------------------------------
The second problem is on an old filesystem with the old quota system,
also with kernel 3.10.10 but another machine. Compilation is different
because this one is 32bit, the other is 64bit. mount options are
defaults,strictatime,nobarrier,nosuid,nodev,commit=30,inode_readahead_blks=64,usrjquota=aquota.user,grpjquota=aquota.group,jqfmt=vfsv1
The problem here is that after removing lots of users in a row
repquota -v shows many entries of removed users in numerical form, like
#42 -- 32 0 0 1 0 0
However all files of the removed users have been deleted and their
quota set to zero with setquota, so there should be no such entries.
After umounting and running quotacheck these entries effectively
disappear. This problem has already happened several times years ago
and had been fixed, but has resurfaced...
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: 3.10.10: quota problems
2013-10-11 23:25 3.10.10: quota problems Carlos Carvalho
@ 2013-10-15 15:53 ` Jan Kara
2013-10-15 21:55 ` Carlos Carvalho
2013-10-16 2:25 ` Theodore Ts'o
0 siblings, 2 replies; 5+ messages in thread
From: Jan Kara @ 2013-10-15 15:53 UTC (permalink / raw)
To: Carlos Carvalho; +Cc: linux-ext4
On Fri 11-10-13 20:25:41, Carlos Carvalho wrote:
> There are two problems. First, on a new filesystem with
> tune2fs -Q usrquota and grpquota was working fine until a power
> failure switched the machine off. On reboot all files seem normal
> but quota -v showed no limits neither usage...
>
> I ran fsck and it said the fs was clean. Then I ran fsck -f and
>
> Pass 5: Checking group summary information
> [QUOTA WARNING] Usage inconsistent for ID 577:actual (12847804416, 308767) != expected (12868194304, 308543)
> [QUOTA WARNING] Usage inconsistent for ID 541:actual (186360393728, 11089) != expected (186340204544, 11085)
>
> ... etc until
>
> Update quota info for quota type 0<y>? yes
>
> then some more of
>
> [QUOTA WARNING] Usage inconsistent for ID 500:actual (192918523904, 20725) != expected (192897576960, 20671)
>
> until
>
> Update quota info for quota type 1<y>? yes
>
> /dev/md3: ***** FILE SYSTEM WAS MODIFIED *****
>
> After remounting and running quota on usage for some users were back
> but not limits. For other users even usage is lost.
>
> This is with 3.10.10, e2fsprogs 1.42.8 (Debian) and mount options
> rw,nosuid,nodev,commit=30,stripe=768,data=ordered,inode_readahead_blks=64
>
> This was the first unclean shutdown of this machine after more than 6
> months of usage. The new quota method looks fragile... Is there
> something I can do get limits and usage back?
No idea here, sorry. I will try to reproduce the problem and see what I
can find. I'd just note that userspace support of hidden quotas in
e2fsprogs is still experimental and Ted pointed out a few problems in it.
Among others I think limits are not properly transferred from old to new
quota file during fsck... But it still doesn't explain why the limits got
lost after the crash. Didn't quotacheck create visible quota files after
the crash or something like that?
> --------------------------------------------------
>
> The second problem is on an old filesystem with the old quota system,
> also with kernel 3.10.10 but another machine. Compilation is different
> because this one is 32bit, the other is 64bit. mount options are
>
> defaults,strictatime,nobarrier,nosuid,nodev,commit=30,inode_readahead_blks=64,usrjquota=aquota.user,grpjquota=aquota.group,jqfmt=vfsv1
>
> The problem here is that after removing lots of users in a row
> repquota -v shows many entries of removed users in numerical form, like
>
> #42 -- 32 0 0 1 0 0
OK, so we still think there is one file with 32KB allocated to the user.
Strange. Isn't it possible there is still some (unlinked) directory
existing which is pwd of some process or something like that? Because
accounting problems in number of used inodes are rather unlikely (that code
is really straightforward).
> However all files of the removed users have been deleted and their
> quota set to zero with setquota, so there should be no such entries.
> After umounting and running quotacheck these entries effectively
> disappear. This problem has already happened several times years ago
> and had been fixed, but has resurfaced...
Honza
--
Jan Kara <jack@suse.cz>
SUSE Labs, CR
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: 3.10.10: quota problems
2013-10-15 15:53 ` Jan Kara
@ 2013-10-15 21:55 ` Carlos Carvalho
2013-10-16 2:25 ` Theodore Ts'o
1 sibling, 0 replies; 5+ messages in thread
From: Carlos Carvalho @ 2013-10-15 21:55 UTC (permalink / raw)
To: Jan Kara; +Cc: linux-ext4
Jan Kara (jack@suse.cz) wrote on 15 October 2013 17:53:
>On Fri 11-10-13 20:25:41, Carlos Carvalho wrote:
>> There are two problems. First, on a new filesystem with
>> tune2fs -Q usrquota and grpquota was working fine until a power
>> failure switched the machine off. On reboot all files seem normal
>> but quota -v showed no limits neither usage...
>>
>> I ran fsck and it said the fs was clean. Then I ran fsck -f and
>>
>> Pass 5: Checking group summary information
>> [QUOTA WARNING] Usage inconsistent for ID 577:actual (12847804416, 308767) != expected (12868194304, 308543)
>> [QUOTA WARNING] Usage inconsistent for ID 541:actual (186360393728, 11089) != expected (186340204544, 11085)
>>
>> ... etc until
>>
>> Update quota info for quota type 0<y>? yes
>>
>> then some more of
>>
>> [QUOTA WARNING] Usage inconsistent for ID 500:actual (192918523904, 20725) != expected (192897576960, 20671)
>>
>> until
>>
>> Update quota info for quota type 1<y>? yes
>>
>> /dev/md3: ***** FILE SYSTEM WAS MODIFIED *****
>>
>> After remounting and running quota on usage for some users were back
>> but not limits. For other users even usage is lost.
>>
>> This is with 3.10.10, e2fsprogs 1.42.8 (Debian) and mount options
>> rw,nosuid,nodev,commit=30,stripe=768,data=ordered,inode_readahead_blks=64
>>
>> This was the first unclean shutdown of this machine after more than 6
>> months of usage. The new quota method looks fragile... Is there
>> something I can do get limits and usage back?
> No idea here, sorry. I will try to reproduce the problem and see what I
>can find. I'd just note that userspace support of hidden quotas in
>e2fsprogs is still experimental and Ted pointed out a few problems in it.
I know. They work fine under normal operations but the broke in this
case, so I'm reporting it.
>Among others I think limits are not properly transferred from old to new
>quota file during fsck...
Not the case here. I started with a just-made empty filesystem. Limits
are enforced, everything works fine except when a crash happens.
>But it still doesn't explain why the limits got lost after the
>crash.
Not only limits, usage was also lost.
>Didn't quotacheck create visible quota files after the crash or
>something like that?
There's no quotachek with the new implementation. Everything should be
done by fsck.
So there are two problems here: one is that both usage and limits info
is rather fragile; they didn't survive the first power loss. The
second problem is that fsck should have recovered usage numbers, even
if it has to crawl the whole fs like quotacheck...
>> --------------------------------------------------
>>
>> The second problem is on an old filesystem with the old quota system,
>> also with kernel 3.10.10 but another machine. Compilation is different
>> because this one is 32bit, the other is 64bit. mount options are
>>
>> defaults,strictatime,nobarrier,nosuid,nodev,commit=30,inode_readahead_blks=64,usrjquota=aquota.user,grpjquota=aquota.group,jqfmt=vfsv1
>>
>> The problem here is that after removing lots of users in a row
>> repquota -v shows many entries of removed users in numerical form, like
>>
>> #42 -- 32 0 0 1 0 0
> OK, so we still think there is one file with 32KB allocated to the user.
>Strange. Isn't it possible there is still some (unlinked) directory
>existing which is pwd of some process or something like that?
No. I modified the boot script right after the filesystem is mounted
to do:
repquota -v /home > /root/quotas-before
quotacheck # takes 20min :-(
repquota -v /home > /root/quotas-after
Here are the real wrong entries in quota-before, that don't exist in
quota-after:
#1121 -- 0 0 0 1 0 0
#531 -- 16496 0 0 60 0 0
#557 -- 0 0 0 1 0 0
#685 -- 4 0 0 2 0 0
It happens after removal of about 50 users.
Note also that these #uid entries are not the only problem;
repquota-{before,after} show MANY other differences in usage of inodes
and disk. Here are a few of
them:
Block limits File limits
User used soft hard grace used soft hard grace
----------------------------------------------------------------------
-root -- 22691376 0 0 248709 0 0
+root -- 22691088 0 0 248632 0 0
-user1 -- 1260088 1300000 1370000 2789 0 0
-user2 -- 2026108 2400000 2410000 10944 0 0
-user3 -- 135165684 750000000 750000000 115438 0 0
-user4 -- 12010356 36000000 36000000 77662 0 0
+user1 -- 1260084 1300000 1370000 2783 0 0
+user2 -- 2026104 2400000 2410000 10943 0 0
+user3 -- 135164656 750000000 750000000 115427 0 0
These differences are after an uptime of about 35 days. This shows
that quota accounting seems to miss stuff. Fortunately the relative
error is small.
>Because accounting problems in number of used inodes are rather
>unlikely (that code is really straightforward).
Strange but it's not new; I've already buggered you around 2006
because kernels of that time had this problem. It was with reiserfs
then, now it's with ext4. The problem disappeared but is back now.
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: 3.10.10: quota problems
2013-10-15 15:53 ` Jan Kara
2013-10-15 21:55 ` Carlos Carvalho
@ 2013-10-16 2:25 ` Theodore Ts'o
2013-10-16 2:58 ` Carlos Carvalho
1 sibling, 1 reply; 5+ messages in thread
From: Theodore Ts'o @ 2013-10-16 2:25 UTC (permalink / raw)
To: Jan Kara; +Cc: Carlos Carvalho, linux-ext4
On Tue, Oct 15, 2013 at 05:53:34PM +0200, Jan Kara wrote:
> On Fri 11-10-13 20:25:41, Carlos Carvalho wrote:
> No idea here, sorry. I will try to reproduce the problem and see what I
> can find. I'd just note that userspace support of hidden quotas in
> e2fsprogs is still experimental and Ted pointed out a few problems in it.
> Among others I think limits are not properly transferred from old to new
> quota file during fsck... But it still doesn't explain why the limits got
> lost after the crash.
This is a known bug, alas. mke2fs -O quota directs the user to read:
https://ext4.wiki.kernel.org/index.php/Quota
for a list of caveats, including:
Support for the quota feature first appeared in e2fsprogs 1.42,
although it is not enabled by default. It must enabled via a
compile-time configuration option, --enable-quota. There are bug fixes
which have been applied in various 1.42.x maintenance branch releases,
so users who wish to experiment with the quota feature are strongly
encouraged upgrade to the latest e2fsprogs 1.42.x maintenance
release. As of this writing the following bugs are still in e2fsprogs
1.42.7, which means use of file systems with the quota feature in
production can not be recommended:
* The e2fsck check of the on-disk quota inodes won't notice if
there is a missing uid record. (i.e., if some uid, say daemon
owns a bunch of files, but that uid record is not in the quota
inode, e2fsck won't say boo.)
* If e2fsck *does* notice a discrepancy between the usage
information recorded in the hidden quota inodes, and the actual
number of blocks used by a particular user id or group id, it
will overwrite the user or group quota inode with all of the
information it has. Unfortunately, in the process it will zero
out all of the current quota limits set. This is unfortunate....
The problem is that the person who originally contributed the code was
working in an environment where they only needed usage tracking, and
they weren't using quota enforcement. So the fact that the e2fsck
code that was submitted was incomplete wasn't something that got
noticed right away.
It's been on my todo list to fix, but I just haven't had time to get
to it. :-( Part of the problem is that it requires some fairly major
restructuring in how the quota support is handled in e2fsprogs.
- Ted
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: 3.10.10: quota problems
2013-10-16 2:25 ` Theodore Ts'o
@ 2013-10-16 2:58 ` Carlos Carvalho
0 siblings, 0 replies; 5+ messages in thread
From: Carlos Carvalho @ 2013-10-16 2:58 UTC (permalink / raw)
To: linux-ext4
Theodore Ts'o (tytso@mit.edu) wrote on 15 October 2013 22:25:
> Support for the quota feature first appeared in e2fsprogs 1.42,
> although it is not enabled by default. It must enabled via a
> compile-time configuration option, --enable-quota. There are bug fixes
> which have been applied in various 1.42.x maintenance branch releases,
> so users who wish to experiment with the quota feature are strongly
> encouraged upgrade to the latest e2fsprogs 1.42.x maintenance
> release. As of this writing the following bugs are still in e2fsprogs
> 1.42.7, which means use of file systems with the quota feature in
> production can not be recommended:
That's why I'm using 1.42.8, the latest version.
> * The e2fsck check of the on-disk quota inodes won't notice if
> there is a missing uid record. (i.e., if some uid, say daemon
> owns a bunch of files, but that uid record is not in the quota
> inode, e2fsck won't say boo.)
>
> * If e2fsck *does* notice a discrepancy between the usage
> information recorded in the hidden quota inodes, and the actual
> number of blocks used by a particular user id or group id, it
> will overwrite the user or group quota inode with all of the
> information it has. Unfortunately, in the process it will zero
> out all of the current quota limits set. This is unfortunate....
Unfortunate indeed but I can work around it. What's really bad is
*wrong usage*:
cyre#~ quota -v user1
Disk quotas for user user1 (uid 634):
Filesystem blocks quota limit grace files quota limit grace
/dev/md3 0 0 0 0 0 0
cyre#~ du -s ~user1
161M /home/users/user1
ls -l ~user1 shows lots of files belonging to user1. For myself:
cyre%~[23:42] quota -v
Disk quotas for user carlos (uid 577):
Filesystem blocks quota limit grace files quota limit grace
/dev/md3 721680 0 0 51064 0 0
cyre%~[23:42] du -s .
13,6G .
How can this be? Looks like a kernel problem.
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2013-10-16 2:58 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2013-10-11 23:25 3.10.10: quota problems Carlos Carvalho
2013-10-15 15:53 ` Jan Kara
2013-10-15 21:55 ` Carlos Carvalho
2013-10-16 2:25 ` Theodore Ts'o
2013-10-16 2:58 ` Carlos Carvalho
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox