1 files changed, 14 insertions, 6 deletions

diff --git a/fs/ext2/super.c b/fs/ext2/super.c
index 5de5061..b2efd90 100644
--- a/fs/ext2/super.c
+++ b/fs/ext2/super.c
@@ -1099,15 +1099,18 @@ static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
 	struct super_block *sb = dentry->d_sb;
 	struct ext2_sb_info *sbi = EXT2_SB(sb);
 	struct ext2_super_block *es = sbi->s_es;
-	unsigned long overhead;
-	int i;
 	u64 fsid;
 
 	if (test_opt (sb, MINIX_DF))
-		overhead = 0;
-	else {
+		sbi->s_overhead_last = 0;
+	else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
+		unsigned long i, overhead = 0;
+		smp_rmb();
+
 		/*
-		 * Compute the overhead (FS structures)
+		 * Compute the overhead (FS structures). This is constant
+		 * for a given filesystem unless the number of block groups
+		 * changes so we cache the previous value until it does.
 		 */
 
 		/*
@@ -1131,17 +1134,22 @@ static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
 		 */
 		overhead += (sbi->s_groups_count *
 			     (2 + sbi->s_itb_per_group));
+		sbi->s_overhead_last = overhead;
+		smp_wmb();
+		sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
 	}
 
 	buf->f_type = EXT2_SUPER_MAGIC;
 	buf->f_bsize = sb->s_blocksize;
-	buf->f_blocks = le32_to_cpu(es->s_blocks_count) - overhead;
+	buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
 	buf->f_bfree = ext2_count_free_blocks(sb);
+	es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
 	buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
 	if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
 		buf->f_bavail = 0;
 	buf->f_files = le32_to_cpu(es->s_inodes_count);
 	buf->f_ffree = ext2_count_free_inodes(sb);
+	es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
 	buf->f_namelen = EXT2_NAME_LEN;
 	fsid = le64_to_cpup((void *)es->s_uuid) ^
 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));