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Date: Thu, 10 Oct 2019 13:14:26 +0800
From: Chengguang Xu <cgxu519@...ernel.net>
To: tytso@....edu, adilger.kernel@...ger.ca
Cc: linux-ext4@...r.kernel.org, Chengguang Xu <cgxu519@...ernel.net>
Subject: [PATCH] ext4: choose hardlimit when softlimit is larger than hardlimit in ext4_statfs_project()
Setting softlimit larger than hardlimit seems meaningless
for disk quota but currently it is allowed. In this case,
there may be a bit of comfusion for users when they run
df comamnd to directory which has project quota.
For example, we set 20M softlimit and 10M hardlimit of
block usage limit for project quota of test_dir(project id 123).
[root@...es mnt_ext4]# repquota -P -a
*** Report for project quotas on device /dev/loop0
Block grace time: 7days; Inode grace time: 7days
Block limits File limits
Project used soft hard grace used soft hard grace
----------------------------------------------------------------------
0 -- 13 0 0 2 0 0
123 -- 10237 20480 10240 5 200 100
The result of df command as below:
[root@...es mnt_ext4]# df -h test_dir
Filesystem Size Used Avail Use% Mounted on
/dev/loop0 20M 10M 10M 50% /home/cgxu/test/mnt_ext4
Even though it looks like there is another 10M free space to use,
if we write new data to diretory test_dir(inherit project id),
the write will fail with errno(-EDQUOT).
After this patch, the df result looks like below.
[root@...es mnt_ext4]# df -h test_dir
Filesystem Size Used Avail Use% Mounted on
/dev/loop0 10M 10M 3.0K 100% /home/cgxu/test/mnt_ext4
Signed-off-by: Chengguang Xu <cgxu519@...ernel.net>
---
fs/ext4/super.c | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index dd654e53ba3d..08d4f993b365 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -5546,9 +5546,11 @@ static int ext4_statfs_project(struct super_block *sb,
return PTR_ERR(dquot);
spin_lock(&dquot->dq_dqb_lock);
- limit = (dquot->dq_dqb.dqb_bsoftlimit ?
- dquot->dq_dqb.dqb_bsoftlimit :
- dquot->dq_dqb.dqb_bhardlimit) >> sb->s_blocksize_bits;
+ limit = ((dquot->dq_dqb.dqb_bhardlimit &&
+ (dquot->dq_dqb.dqb_bhardlimit < dquot->dq_dqb.dqb_bsoftlimit)) ?
+ dquot->dq_dqb.dqb_bhardlimit :
+ dquot->dq_dqb.dqb_bsoftlimit) >> sb->s_blocksize_bits;
+
if (limit && buf->f_blocks > limit) {
curblock = (dquot->dq_dqb.dqb_curspace +
dquot->dq_dqb.dqb_rsvspace) >> sb->s_blocksize_bits;
@@ -5558,9 +5560,11 @@ static int ext4_statfs_project(struct super_block *sb,
(buf->f_blocks - curblock) : 0;
}
- limit = dquot->dq_dqb.dqb_isoftlimit ?
- dquot->dq_dqb.dqb_isoftlimit :
- dquot->dq_dqb.dqb_ihardlimit;
+ limit = (dquot->dq_dqb.dqb_ihardlimit &&
+ (dquot->dq_dqb.dqb_ihardlimit < dquot->dq_dqb.dqb_isoftlimit)) ?
+ dquot->dq_dqb.dqb_ihardlimit :
+ dquot->dq_dqb.dqb_isoftlimit;
+
if (limit && buf->f_files > limit) {
buf->f_files = limit;
buf->f_ffree =
--
2.20.1
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