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* [PATCH] fs/ext4: get project quota from inode for mangling statfs results
@ 2019-10-31 11:03 Dmitry Monakhov
  2019-10-31 16:59 ` Jan Kara
  0 siblings, 1 reply; 6+ messages in thread
From: Dmitry Monakhov @ 2019-10-31 11:03 UTC (permalink / raw)
  To: linux-fsdevel
  Cc: linux-ext4, linux-kernel, jack, tytso, lixi, Dmitry Monakhov,
	Konstantin Khlebnikov

From: Dmitry Monakhov <dmtrmonakhov@yandex-team.ru>

Right now ext4_statfs_project() does quota lookup by id every time.
This is costly operation, especially if there is no inode who hold
reference to this dquot. This means that each statfs performs useless
ext4_acquire_dquot()/ext4_release_dquot() which serialized on __jbd2_log_wait_for_space()
dqget()
 ->ext4_acquire_dquot
   -> ext4_journal_start
      -> __jbd2_log_wait_for_space
dqput()
  -> ext4_release_dquot
     ->ext4_journal_start
       ->__jbd2_log_wait_for_space


Function ext4_statfs_project() could be moved into generic quota code,
it is required for every filesystem which uses generic project quota.

Reported-by: Dmitry Monakhov <dmtrmonakhov@yandex-team.ru>
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
---
 fs/ext4/super.c | 25 ++++++++++++++++---------
 1 file changed, 16 insertions(+), 9 deletions(-)

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 2318e5f..4e8f97d68 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -5532,18 +5532,23 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data)
 }
 
 #ifdef CONFIG_QUOTA
-static int ext4_statfs_project(struct super_block *sb,
-			       kprojid_t projid, struct kstatfs *buf)
+static int ext4_statfs_project(struct inode *inode, struct kstatfs *buf)
 {
-	struct kqid qid;
+	struct super_block *sb = inode->i_sb;
 	struct dquot *dquot;
 	u64 limit;
 	u64 curblock;
+	int err;
+
+	err = dquot_initialize(inode);
+	if (err)
+		return err;
+
+	spin_lock(&inode->i_lock);
+	dquot = ext4_get_dquots(inode)[PRJQUOTA];
+	if (!dquot)
+		goto out_unlock;
 
-	qid = make_kqid_projid(projid);
-	dquot = dqget(sb, qid);
-	if (IS_ERR(dquot))
-		return PTR_ERR(dquot);
 	spin_lock(&dquot->dq_dqb_lock);
 
 	limit = (dquot->dq_dqb.dqb_bsoftlimit ?
@@ -5569,7 +5574,9 @@ static int ext4_statfs_project(struct super_block *sb,
 	}
 
 	spin_unlock(&dquot->dq_dqb_lock);
-	dqput(dquot);
+out_unlock:
+	spin_unlock(&inode->i_lock);
+
 	return 0;
 }
 #endif
@@ -5609,7 +5616,7 @@ static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
 #ifdef CONFIG_QUOTA
 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
-		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
+		ext4_statfs_project(dentry->d_inode, buf);
 #endif
 	return 0;
 }
-- 
2.7.4


^ permalink raw reply related	[flat|nested] 6+ messages in thread
* [PATCH] fs/ext4: get project quota from inode for mangling statfs results
@ 2019-10-28 10:38 Konstantin Khlebnikov
  2019-10-30 10:59 ` Jan Kara
  0 siblings, 1 reply; 6+ messages in thread
From: Konstantin Khlebnikov @ 2019-10-28 10:38 UTC (permalink / raw)
  To: linux-fsdevel, linux-ext4, Theodore Ts'o, linux-kernel, Jan Kara
  Cc: Li Xi, Dmitry Monakhov

Right now ext4_statfs_project() does quota lookup by id every time.
This is costly operation, especially if there is no inode who hold
reference to this quota and dqget() reads it from disk each time.

Function ext4_statfs_project() could be moved into generic quota code,
it is required for every filesystem which uses generic project quota.

Reported-by: Dmitry Monakhov <dmtrmonakhov@yandex-team.ru>
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
---
 fs/ext4/super.c |   25 ++++++++++++++++---------
 1 file changed, 16 insertions(+), 9 deletions(-)

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index dd654e53ba3d..f841c66aa499 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -5532,18 +5532,23 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data)
 }
 
 #ifdef CONFIG_QUOTA
-static int ext4_statfs_project(struct super_block *sb,
-			       kprojid_t projid, struct kstatfs *buf)
+static int ext4_statfs_project(struct inode *inode, struct kstatfs *buf)
 {
-	struct kqid qid;
+	struct super_block *sb = inode->i_sb;
 	struct dquot *dquot;
 	u64 limit;
 	u64 curblock;
+	int err;
+
+	err = dquot_initialize(inode);
+	if (err)
+		return err;
+
+	spin_lock(&inode->i_lock);
+	dquot = ext4_get_dquots(inode)[PRJQUOTA];
+	if (!dquot)
+		goto out_unlock;
 
-	qid = make_kqid_projid(projid);
-	dquot = dqget(sb, qid);
-	if (IS_ERR(dquot))
-		return PTR_ERR(dquot);
 	spin_lock(&dquot->dq_dqb_lock);
 
 	limit = (dquot->dq_dqb.dqb_bsoftlimit ?
@@ -5569,7 +5574,9 @@ static int ext4_statfs_project(struct super_block *sb,
 	}
 
 	spin_unlock(&dquot->dq_dqb_lock);
-	dqput(dquot);
+out_unlock:
+	spin_unlock(&inode->i_lock);
+
 	return 0;
 }
 #endif
@@ -5609,7 +5616,7 @@ static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
 #ifdef CONFIG_QUOTA
 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
-		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
+		ext4_statfs_project(dentry->d_inode, buf);
 #endif
 	return 0;
 }


^ permalink raw reply related	[flat|nested] 6+ messages in thread
end of thread, other threads:[~2019-10-31 16:59 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-10-31 11:03 [PATCH] fs/ext4: get project quota from inode for mangling statfs results Dmitry Monakhov
2019-10-31 16:59 ` Jan Kara
  -- strict thread matches above, loose matches on Subject: below --
2019-10-28 10:38 Konstantin Khlebnikov
2019-10-30 10:59 ` Jan Kara
2019-10-30 11:43   ` Konstantin Khlebnikov
     [not found]   ` <2625831572437163@vla1-6bb9290e4d68.qloud-c.yandex.net>
2019-10-30 12:57     ` Jan Kara

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