quota: Use inode->i_blkbits to get block bits

Andrew has suggested to use inode->i_blkbits to get the block bits info,
rather than use super block's blockbits. That should be faster and emit
less code.
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: Jan Kara <jack@suse.cz>

include/linux/quotaops.h

@@ -410,38 +410,32 @@ static inline void vfs_dq_free_space(struct inode *inode, qsize_t nr)
 
 static inline int vfs_dq_prealloc_block_nodirty(struct inode *inode, qsize_t nr)
 {
-	return vfs_dq_prealloc_space_nodirty(inode,
-			nr << inode->i_sb->s_blocksize_bits);
+	return vfs_dq_prealloc_space_nodirty(inode, nr << inode->i_blkbits);
 }
 
 static inline int vfs_dq_prealloc_block(struct inode *inode, qsize_t nr)
 {
-	return vfs_dq_prealloc_space(inode,
-			nr << inode->i_sb->s_blocksize_bits);
+	return vfs_dq_prealloc_space(inode, nr << inode->i_blkbits);
 }
 
 static inline int vfs_dq_alloc_block_nodirty(struct inode *inode, qsize_t nr)
 {
- 	return vfs_dq_alloc_space_nodirty(inode,
-			nr << inode->i_sb->s_blocksize_bits);
+	return vfs_dq_alloc_space_nodirty(inode, nr << inode->i_blkbits);
 }
 
 static inline int vfs_dq_alloc_block(struct inode *inode, qsize_t nr)
 {
-	return vfs_dq_alloc_space(inode,
-			nr << inode->i_sb->s_blocksize_bits);
+	return vfs_dq_alloc_space(inode, nr << inode->i_blkbits);
 }
 
 static inline int vfs_dq_reserve_block(struct inode *inode, qsize_t nr)
 {
-	return vfs_dq_reserve_space(inode,
-			nr << inode->i_blkbits);
+	return vfs_dq_reserve_space(inode, 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);
+	return vfs_dq_claim_space(inode, nr << inode->i_blkbits);
 }
 
 static inline
@@ -452,12 +446,12 @@ void vfs_dq_release_reservation_block(struct inode *inode, qsize_t nr)
 
 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);
+	vfs_dq_free_space_nodirty(inode, nr << inode->i_blkbits);
 }
 
 static inline void vfs_dq_free_block(struct inode *inode, qsize_t nr)
 {
-	vfs_dq_free_space(inode, nr << inode->i_sb->s_blocksize_bits);
+	vfs_dq_free_space(inode, nr << inode->i_blkbits);
 }
 
 /*