quota: manage reserved space when quota is not active [v2]

Since we implemented generic reserved space management interface,
then it is possible to account reserved space even when quota
is not active (similar to i_blocks/i_bytes).

Without this patch following testcase result in massive comlain from
WARN_ON in dquot_claim_space()

TEST_CASE:
mount /dev/sdb /mnt -oquota
dd if=/dev/zero of=/mnt/test bs=1M count=1
quotaon /mnt
# fs_reserved_spave == 1Mb
# quota_reserved_space == 0, because quota was disabled
dd if=/dev/zero of=/mnt/test seek=1 bs=1M count=1
# fs_reserved_spave == 2Mb
# quota_reserved_space == 1Mb
sync  # ->dquot_claim_space() -> WARN_ON

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Jan Kara <jack@suse.cz>

1 files changed, 6 insertions, 4 deletions

diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
index f6eaf0d8fd6a..f11255b18b58 100644
--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -1354,28 +1354,30 @@ static qsize_t *inode_reserved_space(struct inode * inode)
         return inode->i_sb->dq_op->get_reserved_space(inode);
 }
 
-static void inode_add_rsv_space(struct inode *inode, qsize_t number)
+void inode_add_rsv_space(struct inode *inode, qsize_t number)
 {
         spin_lock(&inode->i_lock);
         *inode_reserved_space(inode) += number;
         spin_unlock(&inode->i_lock);
 }
+EXPORT_SYMBOL(inode_add_rsv_space);
 
-
-static void inode_claim_rsv_space(struct inode *inode, qsize_t number)
+void inode_claim_rsv_space(struct inode *inode, qsize_t number)
 {
         spin_lock(&inode->i_lock);
         *inode_reserved_space(inode) -= number;
         __inode_add_bytes(inode, number);
         spin_unlock(&inode->i_lock);
 }
+EXPORT_SYMBOL(inode_claim_rsv_space);
 
-static void inode_sub_rsv_space(struct inode *inode, qsize_t number)
+void inode_sub_rsv_space(struct inode *inode, qsize_t number)
 {
         spin_lock(&inode->i_lock);
         *inode_reserved_space(inode) -= number;
         spin_unlock(&inode->i_lock);
 }
+EXPORT_SYMBOL(inode_sub_rsv_space);
 
 static qsize_t inode_get_rsv_space(struct inode *inode)
 {