ext4: report delalloc reserve as non-free in statfs for project quota

This reserved space isn't committed yet but cannot be used for allocations.
For userspace it has no difference from used space. XFS already does this.
Signed-off-by: NKonstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Reviewed-by: NJan Kara <jack@suse.cz>
Fixes: 689c958c ("ext4: add project quota support")

fs/ext4/super.c

@@ -5289,7 +5289,8 @@ static int ext4_statfs_project(struct super_block *sb,
 		 dquot->dq_dqb.dqb_bsoftlimit :
 		 dquot->dq_dqb.dqb_bhardlimit) >> sb->s_blocksize_bits;
 	if (limit && buf->f_blocks > limit) {
-		curblock = dquot->dq_dqb.dqb_curspace >> sb->s_blocksize_bits;
+		curblock = (dquot->dq_dqb.dqb_curspace +
+			    dquot->dq_dqb.dqb_rsvspace) >> sb->s_blocksize_bits;
 		buf->f_blocks = limit;
 		buf->f_bfree = buf->f_bavail =
 			(buf->f_blocks > curblock) ?