quota: Increase size of variables for limits and inode usage

So far quota was fine with quota block limits and inode limits/numbers in
a 32-bit type. Now with rapid increase in storage sizes there are coming
requests to be able to handle quota limits above 4TB / more that 2^32 inodes.
So bump up sizes of types in mem_dqblk structure to 64-bits to be able to
handle this. Also update inode allocation / checking functions to use qsize_t
and make global structure keep quota limits in bytes so that things are
consistent.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
diff --git a/include/linux/quotaops.h b/include/linux/quotaops.h
index a558a4c..adcc7ba 100644
--- a/include/linux/quotaops.h
+++ b/include/linux/quotaops.h
@@ -26,10 +26,10 @@
 int dquot_drop(struct inode *inode);
 
 int dquot_alloc_space(struct inode *inode, qsize_t number, int prealloc);
-int dquot_alloc_inode(const struct inode *inode, unsigned long number);
+int dquot_alloc_inode(const struct inode *inode, qsize_t number);
 
 int dquot_free_space(struct inode *inode, qsize_t number);
-int dquot_free_inode(const struct inode *inode, unsigned long number);
+int dquot_free_inode(const struct inode *inode, qsize_t number);
 
 int dquot_transfer(struct inode *inode, struct iattr *iattr);
 int dquot_commit(struct dquot *dquot);