From: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
To: Jan Kara <jack@suse.cz>
Cc: <viro@ZenIV.linux.org.uk>, <dedekind1@gmail.com>,
<richard.weinberger@gmail.com>, <linux-mtd@lists.infradead.org>,
<linux-fsdevel@vger.kernel.org>
Subject: Re: [PATCH v3 36/39] ubifs: implement ubifs_get_qsize to get quota size in ubifs
Date: Mon, 21 Sep 2015 19:02:30 +0800 [thread overview]
Message-ID: <55FFE3C6.2020609@cn.fujitsu.com> (raw)
In-Reply-To: <20150921094452.GC9028@quack.suse.cz>
On 09/21/2015 05:44 PM, Jan Kara wrote:
> On Mon 21-09-15 17:16:49, Dongsheng Yang wrote:
>> On 09/21/2015 05:13 PM, Jan Kara wrote:
>>> On Mon 21-09-15 12:35:01, Dongsheng Yang wrote:
>>>> On 09/18/2015 07:20 PM, Jan Kara wrote:
>>>>>> .... TBH, there is a little different with other filesystems. I did not
>>>>>> use the "disk" space, but the file space in ubifs quota, although dquot
>>>>>> means disk quota. Same with btrfs quota. If we use disk space for quota,
>>>>>> the most common problem from user is that: why I did not reach the limit
>>>>>> but I can not write any byte. COW in btrfs or out-place-updating in
>>>>>> ubifs makes this problem much worse.
>>>>>>
>>>>>> So I choose file space here for ubifs.
>>>>>
>>>>> OK, so these are really two separate questions. I understand your choice of
>>>>> using file space as the amount of space to account for quota purposes and
>>>>> I'm fine with that choice. Another thing is that regardless of how you
>>>>> decide to do quota accounting, you must maintain i_blocks / i_bytes to
>>>>> contain proper value because dquot_transfer() uses that information to update
>>>>> quota usage when inode owner is changed.
>>>>
>>>> But if we don't use i_blocks to get qsize, what we care only in
>>>> dquot_transter() is dquot->dq_dqb. That means, even if the i_blocks
>>>> is not correct in dquot_transfer() in ubifs, that's okey, because we
>>>> will never use this value, right?
>>>
>>> dquot_transfer() will use the value - when file F changes owner from user A
>>> to user B, then you need to decrement amount of space used by F from A's
>>> quota usage and add that amount to B's quota usage. And the amount of space
>>> is obtained via inode_get_bytes() which uses i_blocks and i_bytes. See
>>> __dquot_transfer() in fs/quota/dquot.c for details.
>>
>> Yes, I see it. But if ubifs doesn't use i_blocks and i_bytes to stand
>> for quota size, as I mentioned I want to use i_size. Then we will never
>> use i_blocks. So we only need a to transfer dquot->dq_dqb values. That
>> means, even the i_blocks in dquot_transfer() is not correct, we don't
>> care it. we only need to make sure values in dquot_dq_dqb are
>> transfered, such as dquot->dq_dqb->curspace for user B is equal with
>> i_size.
>
> I think you are missing one thing:
>
> Assume user A has files F1 (1MB) F2 (2MB) F3 (3MB).
> User B has one file G1 (4MB).
>
> So user A uses 6 MB in total (stored in dquot for user A in dqb_curspace
> field). User B uses 4MB.
>
> Now you do "chown B F1"
>
> You need to change dq_dqb of F1 to point to user B quota structure as you
> explain, that is correct. However you also need to subtract 1MB from user
> A's total usage (which is stored in struct dquot for user A) since file F1
> no longer belongs to him. And you need to add 1 MB to user B's total usage.
>
> After this user A will have total usage of 5 MB and user B has usage of 5
> MB as well. You need to properly update the total usage of each user so
> that you can check the usage against quota limits.
But that's all done in dquot_transfer(). It dquot_decr_space(from) and
dquot_incr_space(to). Let me show the test result in my implementation.
(1). root -> 1M/2M/3M yds ->4M
[root@atest-guest linux_compile]# ll -h /mnt/ubifs/
total 11M
-rw-r--r--. 1 root root 1.0M Sep 21 15:54 1M
-rw-r--r--. 1 root root 2.0M Sep 21 15:54 2M
-rw-r--r--. 1 root root 3.0M Sep 21 15:54 3M
-rw-r--r--. 1 yds root 4.0M Sep 21 15:55 4M
-rw-------. 1 root root 6.0K Sep 21 15:53 aquota.group
-rw-------. 1 root root 7.0K Sep 21 15:53 aquota.user
[root@atest-guest linux_compile]# repquota -u /mnt/ubifs/
*** Report for user quotas on device /dev/ubi0_0
Block grace time: 7days; Inode grace time: 7days
Block limits File limits
User used soft hard grace used soft hard grace
----------------------------------------------------------------------
root -- 6144 0 0 4 0 0
yds -- 4096 0 0 1 0 0
(2). chown yds /mnt/ubifs/1M
[root@atest-guest linux_compile]# chown yds /mnt/ubifs/1M
[root@atest-guest linux_compile]# ll -h /mnt/ubifs/
total 11M
-rw-r--r--. 1 yds root 1.0M Sep 21 15:54 1M
-rw-r--r--. 1 root root 2.0M Sep 21 15:54 2M
-rw-r--r--. 1 root root 3.0M Sep 21 15:54 3M
-rw-r--r--. 1 yds root 4.0M Sep 21 15:55 4M
-rw-------. 1 root root 6.0K Sep 21 15:53 aquota.group
-rw-------. 1 root root 7.0K Sep 21 15:53 aquota.user
[root@atest-guest linux_compile]# repquota -u /mnt/ubifs/
*** Report for user quotas on device /dev/ubi0_0
Block grace time: 7days; Inode grace time: 7days
Block limits File limits
User used soft hard grace used soft hard grace
----------------------------------------------------------------------
root -- 5120 0 0 3 0 0
yds -- 5120 0 0 2 0 0
(3). quotacheck and check again.
[root@atest-guest linux_compile]# quotaoff /mnt/ubifs && quotacheck -u
/mnt/ubifs/
[root@atest-guest linux_compile]# ll -h /mnt/ubifs
total 11M
-rw-r--r--. 1 yds root 1.0M Sep 21 15:54 1M
-rw-r--r--. 1 root root 2.0M Sep 21 15:54 2M
-rw-r--r--. 1 root root 3.0M Sep 21 15:54 3M
-rw-r--r--. 1 yds root 4.0M Sep 21 15:55 4M
-rw-------. 1 root root 6.0K Sep 21 15:53 aquota.group
-rw-------. 1 root root 7.0K Sep 21 16:00 aquota.user
[root@atest-guest linux_compile]# repquota -u /mnt/ubifs/
*** Report for user quotas on device /dev/ubi0_0
Block grace time: 7days; Inode grace time: 7days
Block limits File limits
User used soft hard grace used soft hard grace
----------------------------------------------------------------------
root -- 5120 0 0 3 0 0
yds -- 5120 0 0 2 0 0
Yang
>
> Honza
>
next prev parent reply other threads:[~2015-09-21 11:08 UTC|newest]
Thread overview: 107+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-09-15 9:01 [PATCH v3 00/39] Add quota supporting in ubifs Dongsheng Yang
2015-09-15 9:01 ` Dongsheng Yang
2015-09-15 9:01 ` [PATCH v3 01/39] fs: introduce a ->s_cdev field into struct super_block Dongsheng Yang
2015-09-15 9:01 ` Dongsheng Yang
2015-10-04 6:31 ` Christoph Hellwig
2015-10-05 8:36 ` Jan Kara
2015-09-15 9:01 ` [PATCH v3 02/39] fs: cleanup: remove the blank line before EXPORT_SYMBOL Dongsheng Yang
2015-09-15 9:01 ` Dongsheng Yang
2015-09-15 9:01 ` [PATCH v3 03/39] fs: super: cleanup: make the comment of each function aligned Dongsheng Yang
2015-09-15 9:01 ` Dongsheng Yang
2015-09-15 9:01 ` [PATCH v3 04/39] fs: super: consolidate the get_super class functions Dongsheng Yang
2015-09-15 9:01 ` Dongsheng Yang
2015-09-15 9:02 ` [PATCH v3 05/39] fs: super: introduce a get_super_cdev to get super by a cdev reference Dongsheng Yang
2015-09-15 9:02 ` Dongsheng Yang
2015-10-04 6:32 ` Christoph Hellwig
2015-09-15 9:02 ` [PATCH v3 06/39] fs: super: introduce a get_super_cdev_thawed to get sb by " Dongsheng Yang
2015-09-15 9:02 ` Dongsheng Yang
2015-09-15 21:24 ` Jan Kara
2015-09-15 9:02 ` [PATCH v3 07/39] fs: char_dev: introduce cd_acquire function to acquire cdev Dongsheng Yang
2015-09-15 9:02 ` Dongsheng Yang
2015-09-16 8:16 ` Jan Kara
2015-09-17 3:30 ` Dongsheng Yang
2015-09-15 9:02 ` [PATCH v3 08/39] fs: introduce a __lookup_dev for internal using Dongsheng Yang
2015-09-15 9:02 ` Dongsheng Yang
2015-09-15 9:02 ` [PATCH v3 09/39] fs: char_dev: introduce lookup_cdev to get cdev by pathname Dongsheng Yang
2015-09-15 9:02 ` [PATCH v3 10/39] fs: dquot: skip invalidate_bdev if bdev is NULL Dongsheng Yang
2015-09-15 9:02 ` [PATCH v3 11/39] fs: quota: replace opened calling of ->sync_fs with sync_filesystem Dongsheng Yang
2015-09-15 9:02 ` Dongsheng Yang
2015-09-16 10:14 ` Jan Kara
2015-09-17 6:28 ` Dongsheng Yang
2015-09-17 6:28 ` Dongsheng Yang
2015-09-17 11:05 ` Jan Kara
2015-09-18 5:49 ` Dongsheng Yang
2015-09-18 9:00 ` Jan Kara
2015-09-21 4:31 ` Dongsheng Yang
2015-09-15 9:02 ` [PATCH v3 12/39] fs: quota: make quota support fs which is running on char dev Dongsheng Yang
2015-09-15 9:02 ` [PATCH v3 13/39] fs: introduce a get_qsize() to inode_operations Dongsheng Yang
2015-10-04 6:33 ` Christoph Hellwig
2015-10-05 8:01 ` Jan Kara
2015-09-15 9:02 ` [PATCH v3 14/39] fs: quota: restore i_flags of quota files in dquot_disable Dongsheng Yang
2015-09-15 9:02 ` Dongsheng Yang
2015-09-15 9:02 ` [PATCH v3 15/39] fs: quota: introduce a callback of restore_iflags to quotactl_ops Dongsheng Yang
2015-09-15 9:02 ` Dongsheng Yang
2015-09-16 9:47 ` Jan Kara
2015-09-15 9:02 ` [PATCH v3 16/39] ubi: introduce a interface to get cdev in ubi_volume Dongsheng Yang
2015-09-15 9:02 ` Dongsheng Yang
2015-09-15 9:02 ` [PATCH v3 17/39] ubifs: extend budget for blocks Dongsheng Yang
2015-09-15 9:02 ` Dongsheng Yang
2015-09-15 9:02 ` [PATCH v3 18/39] ubifs: fill sb->s_cdev in ubifs_fill_super() Dongsheng Yang
2015-09-15 9:02 ` Dongsheng Yang
2015-09-15 9:02 ` [PATCH v3 19/39] ubifs: fill ->s_dev in ubifs_fill_super Dongsheng Yang
2015-09-15 9:02 ` Dongsheng Yang
2015-09-15 9:02 ` [PATCH v3 20/39] ubifs: export read_block() from file.c Dongsheng Yang
2015-09-15 9:02 ` Dongsheng Yang
2015-09-15 9:02 ` [PATCH v3 21/39] ubifs: introduce i_dquot to ubifs_inode Dongsheng Yang
2015-09-15 9:02 ` Dongsheng Yang
2015-09-15 9:02 ` [PATCH v3 22/39] ubifs: implement IO functions for quota files Dongsheng Yang
2015-09-15 9:02 ` Dongsheng Yang
2015-09-15 9:02 ` [PATCH v3 23/39] ubifs: disable quota in ubifs_put_super Dongsheng Yang
2015-09-15 9:02 ` Dongsheng Yang
2015-09-15 9:02 ` [PATCH v3 24/39] ubifs: write quota back in ubifs_sync Dongsheng Yang
2015-09-15 9:02 ` Dongsheng Yang
2015-09-15 9:02 ` [PATCH v3 25/39] ubifs: set/clear MS_RDONLY properly in ubifs_remount Dongsheng Yang
2015-09-15 9:02 ` [PATCH v3 26/39] ubifs: suspend & resume quota " Dongsheng Yang
2015-09-15 9:02 ` Dongsheng Yang
2015-09-15 9:02 ` [PATCH v3 27/39] ubifs: check inode with NULL before using it Dongsheng Yang
2015-09-15 9:02 ` Dongsheng Yang
2015-09-15 9:02 ` [PATCH v3 28/39] ubifs: record quota information about inode in ubifs_new_inode Dongsheng Yang
2015-09-15 9:02 ` Dongsheng Yang
2015-09-15 9:35 ` Sheng Yong
2015-09-16 1:46 ` Dongsheng Yang
2015-09-15 9:02 ` [PATCH v3 29/39] ubifs: free quota inode information in ubifs_evict_inode Dongsheng Yang
2015-09-15 9:02 ` Dongsheng Yang
2015-09-15 9:02 ` [PATCH v3 30/39] ubifs: alloc quota space in ubifs writing path Dongsheng Yang
2015-09-15 9:02 ` Dongsheng Yang
2015-09-15 9:02 ` [PATCH v3 31/39] ubifs: free quota space in do_truncation Dongsheng Yang
2015-09-15 9:02 ` [PATCH v3 32/39] ubifs: free quota space when deleting a file Dongsheng Yang
2015-09-15 9:02 ` Dongsheng Yang
2015-09-15 9:02 ` [PATCH v3 33/39] ubifs: adapt quota space informatin in do_setattr Dongsheng Yang
2015-09-15 9:02 ` Dongsheng Yang
2015-09-15 9:02 ` [PATCH v3 34/39] ubifs: transfer quota information in changing owner or group Dongsheng Yang
2015-09-15 9:02 ` Dongsheng Yang
2015-09-15 9:02 ` [PATCH v3 35/39] ubifs: write inode in ubifs_quota_write if we are appending Dongsheng Yang
2015-09-15 9:02 ` Dongsheng Yang
2015-09-15 9:02 ` [PATCH v3 36/39] ubifs: implement ubifs_get_qsize to get quota size in ubifs Dongsheng Yang
2015-09-16 10:00 ` Jan Kara
2015-09-17 7:23 ` Dongsheng Yang
2015-09-17 7:23 ` Dongsheng Yang
2015-09-17 12:00 ` Jan Kara
2015-09-18 6:14 ` Dongsheng Yang
2015-09-18 11:20 ` Jan Kara
2015-09-21 4:35 ` Dongsheng Yang
2015-09-21 9:13 ` Jan Kara
2015-09-21 9:16 ` Dongsheng Yang
2015-09-21 9:44 ` Jan Kara
2015-09-21 11:02 ` Dongsheng Yang [this message]
2015-09-23 7:42 ` Jan Kara
2015-09-24 0:50 ` Dongsheng Yang
2015-09-15 9:02 ` [PATCH v3 37/39] ubifs: implement ubifs_restore_iflags for quotactl_operations Dongsheng Yang
2015-09-15 9:02 ` Dongsheng Yang
2015-09-15 9:02 ` [PATCH v3 38/39] ubifs: fill the quota related fields in ubifs_fill_super Dongsheng Yang
2015-09-15 9:02 ` [PATCH v3 39/39] ubifs: introduce quota related mount options Dongsheng Yang
2015-09-15 9:02 ` Dongsheng Yang
2015-09-15 9:36 ` Sheng Yong
2015-09-16 1:48 ` Dongsheng Yang
2015-10-03 18:57 ` [PATCH v3 00/39] Add quota supporting in ubifs Richard Weinberger
2015-10-04 2:32 ` Dongsheng Yang
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