quota: Add quota reservation claim and released operations

Reserved quota will be claimed at the block allocation time. Over-booked
quota could be returned back with the release callback function.

Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: Jan Kara <jack@suse.cz>

2 files changed, 59 insertions, 0 deletions

diff --git a/include/linux/quota.h b/include/linux/quota.h
index 54b837fa64f..a510d91561f 100644
--- a/include/linux/quota.h
+++ b/include/linux/quota.h
@@ -311,6 +311,12 @@ struct dquot_operations {
 	int (*write_info) (struct super_block *, int);	/* Write of quota "superblock" */
 	/* reserve quota for delayed block allocation */
 	int (*reserve_space) (struct inode *, qsize_t, int);
+	/* claim reserved quota for delayed alloc */
+	int (*claim_space) (struct inode *, qsize_t);
+	/* release rsved quota for delayed alloc */
+	void (*release_rsv) (struct inode *, qsize_t);
+	/* get reserved quota for delayed alloc */
+	qsize_t (*get_reserved_space) (struct inode *);
 };
 
 /* Operations handling requests from userspace */
diff --git a/include/linux/quotaops.h b/include/linux/quotaops.h
index 3e3a0d2874d..7369d04e0a8 100644
--- a/include/linux/quotaops.h
+++ b/include/linux/quotaops.h
@@ -35,6 +35,11 @@ void dquot_destroy(struct dquot *dquot);
 int dquot_alloc_space(struct inode *inode, qsize_t number, int prealloc);
 int dquot_alloc_inode(const struct inode *inode, qsize_t number);
 
+int dquot_reserve_space(struct inode *inode, qsize_t number, int prealloc);
+int dquot_claim_space(struct inode *inode, qsize_t number);
+void dquot_release_reserved_space(struct inode *inode, qsize_t number);
+qsize_t dquot_get_reserved_space(struct inode *inode);
+
 int dquot_free_space(struct inode *inode, qsize_t number);
 int dquot_free_inode(const struct inode *inode, qsize_t number);
 
@@ -203,6 +208,31 @@ static inline int vfs_dq_alloc_inode(struct inode *inode)
 	return 0;
 }
 
+/*
+ * Convert in-memory reserved quotas to real consumed quotas
+ */
+static inline int vfs_dq_claim_space(struct inode *inode, qsize_t nr)
+{
+	if (sb_any_quota_active(inode->i_sb)) {
+		if (inode->i_sb->dq_op->claim_space(inode, nr) == NO_QUOTA)
+			return 1;
+	} else
+		inode_add_bytes(inode, nr);
+
+	mark_inode_dirty(inode);
+	return 0;
+}
+
+/*
+ * Release reserved (in-memory) quotas
+ */
+static inline
+void vfs_dq_release_reservation_space(struct inode *inode, qsize_t nr)
+{
+	if (sb_any_quota_active(inode->i_sb))
+		inode->i_sb->dq_op->release_rsv(inode, nr);
+}
+
 static inline void vfs_dq_free_space_nodirty(struct inode *inode, qsize_t nr)
 {
 	if (sb_any_quota_active(inode->i_sb))
@@ -354,6 +384,17 @@ static inline int vfs_dq_reserve_space(struct inode *inode, qsize_t nr)
 	return 0;
 }
 
+static inline int vfs_dq_claim_space(struct inode *inode, qsize_t nr)
+{
+	return vfs_dq_alloc_space(inode, nr);
+}
+
+static inline
+int vfs_dq_release_reservation_space(struct inode *inode, qsize_t nr)
+{
+	return 0;
+}
+
 static inline void vfs_dq_free_space_nodirty(struct inode *inode, qsize_t nr)
 {
 	inode_sub_bytes(inode, nr);
@@ -397,6 +438,18 @@ static inline int vfs_dq_reserve_block(struct inode *inode, qsize_t nr)
 			nr << inode->i_blkbits);
 }
 
+static inline int vfs_dq_claim_block(struct inode *inode, qsize_t nr)
+{
+	return vfs_dq_claim_space(inode,
+			nr << inode->i_blkbits);
+}
+
+static inline
+void vfs_dq_release_reservation_block(struct inode *inode, qsize_t nr)
+{
+	vfs_dq_release_reservation_space(inode, nr << inode->i_blkbits);
+}
+
 static inline void vfs_dq_free_block_nodirty(struct inode *inode, qsize_t nr)
 {
 	vfs_dq_free_space_nodirty(inode, nr << inode->i_sb->s_blocksize_bits);