[PATCH 3/4] introduce get_id callback

[Dmitry Monakhov <dmonakhov@openvz.org>]

During some quota oparations we have to determine quota_id for given inode
according to quota_type. But only USRQUOTA/GRPQUOTA id are intermediately
accessible from generic vfs-inode. This patch introduce new per_sb quota
operation for this purpose.

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
---
 fs/ext3/super.c          |    1 +
 fs/ext4/super.c          |    1 +
 fs/ocfs2/quota_global.c  |    1 +
 fs/quota/dquot.c         |   39 +++++++++++++++++++++++++++++----------
 fs/reiserfs/super.c      |    1 +
 include/linux/quota.h    |    1 +
 include/linux/quotaops.h |    1 +
 7 files changed, 35 insertions(+), 10 deletions(-)

diff --git a/fs/ext3/super.c b/fs/ext3/super.c
index 241c520..82bf9c8 100644
--- a/fs/ext3/super.c
+++ b/fs/ext3/super.c
@@ -757,6 +757,7 @@ static const struct dquot_operations ext3_quota_operations = {
 	.free_space	= dquot_free_space,
 	.free_inode	= dquot_free_inode,
 	.transfer	= dquot_transfer,
+	.get_id		= dquot_get_id,
 	.write_dquot	= ext3_write_dquot,
 	.acquire_dquot	= ext3_acquire_dquot,
 	.release_dquot	= ext3_release_dquot,
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 735c20d..cd0dffa 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1025,6 +1025,7 @@ static const struct dquot_operations ext4_quota_operations = {
 	.free_space	= dquot_free_space,
 	.free_inode	= dquot_free_inode,
 	.transfer	= dquot_transfer,
+	.get_id		= dquot_get_id,
 	.write_dquot	= ext4_write_dquot,
 	.acquire_dquot	= ext4_acquire_dquot,
 	.release_dquot	= ext4_release_dquot,
diff --git a/fs/ocfs2/quota_global.c b/fs/ocfs2/quota_global.c
index b437dc0..1ede78f 100644
--- a/fs/ocfs2/quota_global.c
+++ b/fs/ocfs2/quota_global.c
@@ -858,6 +858,7 @@ const struct dquot_operations ocfs2_quota_operations = {
 	.free_space	= dquot_free_space,
 	.free_inode	= dquot_free_inode,
 	.transfer	= dquot_transfer,
+	.get_id		= dquot_get_id,
 	.write_dquot	= ocfs2_write_dquot,
 	.acquire_dquot	= ocfs2_acquire_dquot,
 	.release_dquot	= ocfs2_release_dquot,
diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
index 6768584..22bf600 100644
--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -298,6 +298,26 @@ static inline void remove_inuse(struct dquot *dquot)
 	dqstats.allocated_dquots--;
 	list_del(&dquot->dq_inuse);
 }
+
+qid_t dquot_get_id(struct inode *inode, int type, qid_t *new)
+{
+	switch (type) {
+	case USRQUOTA:
+		if (new)
+			return new[USRQUOTA];
+		else
+			return inode->i_uid;
+	case GRPQUOTA:
+		if (new)
+			return new[GRPQUOTA];
+		else
+			return inode->i_gid;
+	default:
+		BUG();
+	}
+}
+EXPORT_SYMBOL(dquot_get_id);
+
 /*
  * End of list functions needing dq_list_lock
  */
@@ -1288,14 +1308,9 @@ int dquot_initialize(struct inode *inode, int type)
 		got[cnt] = NULL;
 		if (type != -1 && cnt != type)
 			continue;
-		switch (cnt) {
-		case USRQUOTA:
-			id = inode->i_uid;
-			break;
-		case GRPQUOTA:
-			id = inode->i_gid;
-			break;
-		}
+		if (!sb_has_quota_active(sb, cnt))
+			continue;
+		id = inode->i_sb->dq_op->get_id(inode, cnt, NULL);
 		got[cnt] = dqget(sb, id, cnt);
 	}
 
@@ -1677,6 +1692,7 @@ int dquot_transfer(struct inode *inode, qid_t *chid, unsigned long mask)
 	int cnt, ret = QUOTA_OK;
 	char warntype_to[MAXQUOTAS];
 	char warntype_from_inodes[MAXQUOTAS], warntype_from_space[MAXQUOTAS];
+	qid_t id;
 
 	/* First test before acquiring mutex - solves deadlocks when we
          * re-enter the quota code and are already holding the mutex */
@@ -1689,8 +1705,10 @@ int dquot_transfer(struct inode *inode, qid_t *chid, unsigned long mask)
 		warntype_to[cnt] = QUOTA_NL_NOWARN;
 	}
 	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
-		if (mask & (1 << cnt))
-			transfer_to[cnt] = dqget(inode->i_sb, chid[cnt], cnt);
+		if (mask & (1 << cnt)) {
+			id = inode->i_sb->dq_op->get_id(inode, cnt, chid);
+			transfer_to[cnt] = dqget(inode->i_sb, id, cnt);
+		}
 	}
 	down_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
 	if (IS_NOQUOTA(inode)) {	/* File without quota accounting? */
@@ -1818,6 +1836,7 @@ const struct dquot_operations dquot_operations = {
 	.free_space	= dquot_free_space,
 	.free_inode	= dquot_free_inode,
 	.transfer	= dquot_transfer,
+	.get_id		= dquot_get_id,
 	.write_dquot	= dquot_commit,
 	.acquire_dquot	= dquot_acquire,
 	.release_dquot	= dquot_release,
diff --git a/fs/reiserfs/super.c b/fs/reiserfs/super.c
index b4a7dd0..897f2bc 100644
--- a/fs/reiserfs/super.c
+++ b/fs/reiserfs/super.c
@@ -623,6 +623,7 @@ static const struct dquot_operations reiserfs_quota_operations = {
 	.free_space = dquot_free_space,
 	.free_inode = dquot_free_inode,
 	.transfer = dquot_transfer,
+	.get_id		= dquot_get_id,
 	.write_dquot = reiserfs_write_dquot,
 	.acquire_dquot = reiserfs_acquire_dquot,
 	.release_dquot = reiserfs_release_dquot,
diff --git a/include/linux/quota.h b/include/linux/quota.h
index 74738e9..abf6a5a 100644
--- a/include/linux/quota.h
+++ b/include/linux/quota.h
@@ -303,6 +303,7 @@ struct dquot_operations {
 	int (*free_inode) (const struct inode *, qsize_t);
 	int (*transfer) (struct inode *, qid_t *, unsigned long);
 	int (*write_dquot) (struct dquot *);		/* Ordinary dquot write */
+	qid_t (*get_id)(struct inode *, int, qid_t *new); /* Quota id for given type */
 	struct dquot *(*alloc_dquot)(struct super_block *, int);	/* Allocate memory for new dquot */
 	void (*destroy_dquot)(struct dquot *);		/* Free memory for dquot */
 	int (*acquire_dquot) (struct dquot *);		/* Quota is going to be created on disk */
diff --git a/include/linux/quotaops.h b/include/linux/quotaops.h
index d045a07..e4c6d6e 100644
--- a/include/linux/quotaops.h
+++ b/include/linux/quotaops.h
@@ -30,6 +30,7 @@ void inode_add_rsv_space(struct inode *inode, qsize_t number);
 void inode_claim_rsv_space(struct inode *inode, qsize_t number);
 void inode_sub_rsv_space(struct inode *inode, qsize_t number);
 
+qid_t dquot_get_id(struct inode *inode, int type, qid_t *new);
 int dquot_initialize(struct inode *inode, int type);
 int dquot_drop(struct inode *inode);
 struct dquot *dqget(struct super_block *sb, unsigned int id, int type);
-- 
1.6.6