3 files changed, 13 insertions, 1 deletions

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 1b0c17364631..0bd39188531c 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -683,7 +683,8 @@ struct ext4_super_block {
         __u8    s_log_groups_per_flex;  /* FLEX_BG group size */
         __u8    s_reserved_char_pad2;
         __le16  s_reserved_pad;
-        __u32   s_reserved[162];        /* Padding to the end of the block */
+        __le64  s_kbytes_written;       /* nr of lifetime kilobytes written */
+        __u32   s_reserved[160];        /* Padding to the end of the block */
 };
 
 #ifdef __KERNEL__
diff --git a/fs/ext4/ext4_sb.h b/fs/ext4/ext4_sb.h
index 4e4d9cc3f40d..50ab1169c378 100644
--- a/fs/ext4/ext4_sb.h
+++ b/fs/ext4/ext4_sb.h
@@ -142,6 +142,10 @@ struct ext4_sb_info {
         /* locality groups */
         struct ext4_locality_group *s_locality_groups;
 
+        /* for write statistics */
+        unsigned long s_sectors_written_start;
+        u64 s_kbytes_written;
+
         unsigned int s_log_groups_per_flex;
         struct flex_groups *s_flex_groups;
 };
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index a3768709ce05..30fc27cdf8fc 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -2035,6 +2035,8 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
         sbi->s_resgid = EXT4_DEF_RESGID;
         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
         sbi->s_sb_block = sb_block;
+        sbi->s_sectors_written_start = part_stat_read(sb->s_bdev->bd_part,
+                                                      sectors[1]);
 
         unlock_kernel();
 
@@ -2072,6 +2074,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
         sb->s_magic = le16_to_cpu(es->s_magic);
         if (sb->s_magic != EXT4_SUPER_MAGIC)
                 goto cantfind_ext4;
+        sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
 
         /* Set defaults before we parse the mount options */
         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
@@ -2921,6 +2924,10 @@ static int ext4_commit_super(struct super_block *sb,
                 set_buffer_uptodate(sbh);
         }
         es->s_wtime = cpu_to_le32(get_seconds());
+        es->s_kbytes_written =
+                cpu_to_le64(EXT4_SB(sb)->s_kbytes_written + 
+                            ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
+                              EXT4_SB(sb)->s_sectors_written_start) >> 1));
         ext4_free_blocks_count_set(es, percpu_counter_sum_positive(
                                         &EXT4_SB(sb)->s_freeblocks_counter));
         es->s_free_inodes_count = cpu_to_le32(percpu_counter_sum_positive(