diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 086cb0525cd1..92d892f92075 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1142,11 +1142,9 @@ int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
 			     struct btrfs_root *root,
 			     struct btrfs_path *path, u64 objectid,
 			     u64 bytenr, int mod);
-int btrfs_csum_file_block(struct btrfs_trans_handle *trans,
-			  struct btrfs_root *root,
-			  struct inode *inode,
-			  u64 objectid, u64 offset,
-			  char *data, size_t len);
+int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
+			   struct btrfs_root *root, struct inode *inode,
+			   struct bio *bio);
 struct btrfs_csum_item *btrfs_lookup_csum(struct btrfs_trans_handle *trans,
 					  struct btrfs_root *root,
 					  struct btrfs_path *path,
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index fb6400895ed6..e8130c876330 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -1705,6 +1705,8 @@ static int submit_one_bio(int rw, struct bio *bio)
 			(unsigned long long)bio->bi_sector);
 		WARN_ON(1);
 	}
+	if (tree->ops && tree->ops->submit_bio_hook)
+		tree->ops->submit_bio_hook(rw, bio);
 
 	submit_bio(rw, bio);
 	if (bio_flagged(bio, BIO_EOPNOTSUPP))
diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index fcc4bb078c24..9d6654667089 100644
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -28,6 +28,7 @@ struct extent_state;
 struct extent_io_ops {
 	int (*fill_delalloc)(struct inode *inode, u64 start, u64 end);
 	int (*writepage_io_hook)(struct page *page, u64 start, u64 end);
+	int (*submit_bio_hook)(int rw, struct bio *bio);
 	int (*readpage_io_hook)(struct page *page, u64 start, u64 end);
 	int (*readpage_end_io_hook)(struct page *page, u64 start, u64 end,
 				    struct extent_state *state);
diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index 3ebbc058d082..3f0e71b0e5d9 100644
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -16,6 +16,9 @@
  * Boston, MA 021110-1307, USA.
  */
 
+#include <linux/bio.h>
+#include <linux/pagemap.h>
+#include <linux/highmem.h>
 #include "ctree.h"
 #include "disk-io.h"
 #include "transaction.h"
@@ -131,28 +134,35 @@ int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
 	return ret;
 }
 
-int btrfs_csum_file_block(struct btrfs_trans_handle *trans,
-			  struct btrfs_root *root,
-			  struct inode *inode,
-			  u64 objectid, u64 offset,
-			  char *data, size_t len)
+int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
+			   struct btrfs_root *root, struct inode *inode,
+			   struct bio *bio)
 {
+	u64 objectid = inode->i_ino;
+	u64 offset;
 	int ret;
 	struct btrfs_key file_key;
 	struct btrfs_key found_key;
-	u64 next_offset = (u64)-1;
-	int found_next = 0;
+	u64 next_offset;
+	int found_next;
 	struct btrfs_path *path;
 	struct btrfs_csum_item *item;
+	struct btrfs_csum_item *item_end;
 	struct extent_buffer *leaf = NULL;
 	u64 csum_offset;
-	u32 csum_result = ~(u32)0;
+	u32 csum_result;
 	u32 nritems;
 	u32 ins_size;
+	int bio_index = 0;
+	struct bio_vec *bvec = bio->bi_io_vec;
+	char *data;
 
 	path = btrfs_alloc_path();
 	BUG_ON(!path);
-
+again:
+	next_offset = (u64)-1;
+	found_next = 0;
+	offset = page_offset(bvec->bv_page) + bvec->bv_offset;
 	file_key.objectid = objectid;
 	file_key.offset = offset;
 	btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
@@ -259,7 +269,15 @@ csum:
 	item = (struct btrfs_csum_item *)((unsigned char *)item +
 					  csum_offset * BTRFS_CRC32_SIZE);
 found:
-	csum_result = btrfs_csum_data(root, data, csum_result, len);
+	item_end = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
+	item_end = (struct btrfs_csum_item *)((unsigned char *)item_end +
+				      btrfs_item_size_nr(leaf, path->slots[0]));
+next_bvec:
+	data = kmap_atomic(bvec->bv_page, KM_IRQ0);
+	csum_result = ~(u32)0;
+	csum_result = btrfs_csum_data(root, data + bvec->bv_offset,
+				      csum_result, bvec->bv_len);
+	kunmap_atomic(data, KM_IRQ0);
 	btrfs_csum_final(csum_result, (char *)&csum_result);
 	if (csum_result == 0) {
 		printk("csum result is 0 for inode %lu offset %Lu\n", inode->i_ino, offset);
@@ -267,9 +285,19 @@ found:
 
 	write_extent_buffer(leaf, &csum_result, (unsigned long)item,
 			    BTRFS_CRC32_SIZE);
+	bio_index++;
+	bvec++;
+	if (bio_index < bio->bi_vcnt) {
+		item = (struct btrfs_csum_item *)((char *)item + BTRFS_CRC32_SIZE);
+		if (item < item_end)
+			goto next_bvec;
+	}
 	btrfs_mark_buffer_dirty(path->nodes[0]);
+	if (bio_index < bio->bi_vcnt) {
+		btrfs_release_path(root, path);
+		goto again;
+	}
 fail:
-	btrfs_release_path(root, path);
 	btrfs_free_path(path);
 	return ret;
 }
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 3e79572a5cb1..bbb71fad861a 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -16,6 +16,7 @@
  * Boston, MA 021110-1307, USA.
  */
 
+#include <linux/bio.h>
 #include <linux/buffer_head.h>
 #include <linux/fs.h>
 #include <linux/pagemap.h>
@@ -294,6 +295,32 @@ int btrfs_clear_bit_hook(struct inode *inode, u64 start, u64 end,
 	return 0;
 }
 
+int btrfs_submit_bio_hook(int rw, struct bio *bio)
+{
+	// struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
+	struct bio_vec *bvec = bio->bi_io_vec;
+	struct inode *inode = bvec->bv_page->mapping->host;
+	struct btrfs_root *root = BTRFS_I(inode)->root;
+	struct btrfs_trans_handle *trans;
+	int ret = 0;
+
+	if (rw != WRITE)
+		return 0;
+
+	if (btrfs_test_opt(root, NODATASUM) ||
+	    btrfs_test_flag(inode, NODATASUM))
+		return 0;
+
+	mutex_lock(&root->fs_info->fs_mutex);
+	trans = btrfs_start_transaction(root, 1);
+	btrfs_set_trans_block_group(trans, inode);
+	btrfs_csum_file_blocks(trans, root, inode, bio);
+	ret = btrfs_end_transaction(trans, root);
+	BUG_ON(ret);
+	mutex_unlock(&root->fs_info->fs_mutex);
+	return ret;
+}
+#if 0
 int btrfs_writepage_io_hook(struct page *page, u64 start, u64 end)
 {
 	struct inode *inode = page->mapping->host;
@@ -318,7 +345,7 @@ int btrfs_writepage_io_hook(struct page *page, u64 start, u64 end)
 	mutex_unlock(&root->fs_info->fs_mutex);
 	return ret;
 }
-
+#endif
 int btrfs_readpage_io_hook(struct page *page, u64 start, u64 end)
 {
 	int ret = 0;
@@ -3022,7 +3049,8 @@ static struct file_operations btrfs_dir_file_operations = {
 
 static struct extent_io_ops btrfs_extent_io_ops = {
 	.fill_delalloc = run_delalloc_range,
-	.writepage_io_hook = btrfs_writepage_io_hook,
+	// .writepage_io_hook = btrfs_writepage_io_hook,
+	.submit_bio_hook = btrfs_submit_bio_hook,
 	.readpage_io_hook = btrfs_readpage_io_hook,
 	.readpage_end_io_hook = btrfs_readpage_end_io_hook,
 	.set_bit_hook = btrfs_set_bit_hook,