diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 1e4627c..617b577 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -1777,6 +1777,64 @@
 	return ret;
 }
 
+void extent_cache_csums_dio(struct extent_io_tree *tree, u64 start, u32 csums[],
+			    int count)
+{
+	struct rb_node *node;
+	struct extent_state *state;
+
+	spin_lock(&tree->lock);
+	/*
+	 * this search will find all the extents that end after
+	 * our range starts.
+	 */
+	node = tree_search(tree, start);
+	BUG_ON(!node);
+
+	state = rb_entry(node, struct extent_state, rb_node);
+	BUG_ON(state->start != start);
+
+	while (count) {
+		state->private = *csums++;
+		count--;
+		state = next_state(state);
+	}
+	spin_unlock(&tree->lock);
+}
+
+static inline u64 __btrfs_get_bio_offset(struct bio *bio, int bio_index)
+{
+	struct bio_vec *bvec = bio->bi_io_vec + bio_index;
+
+	return page_offset(bvec->bv_page) + bvec->bv_offset;
+}
+
+void extent_cache_csums(struct extent_io_tree *tree, struct bio *bio, int bio_index,
+			u32 csums[], int count)
+{
+	struct rb_node *node;
+	struct extent_state *state = NULL;
+	u64 start;
+
+	spin_lock(&tree->lock);
+	do {
+		start = __btrfs_get_bio_offset(bio, bio_index);
+		if (state == NULL || state->start != start) {
+			node = tree_search(tree, start);
+			BUG_ON(!node);
+
+			state = rb_entry(node, struct extent_state, rb_node);
+			BUG_ON(state->start != start);
+		}
+		state->private = *csums++;
+		count--;
+		bio_index++;
+
+		state = next_state(state);
+	} while (count);
+	spin_unlock(&tree->lock);
+}
+
 int get_state_private(struct extent_io_tree *tree, u64 start, u64 *private)
 {
 	struct rb_node *node;
diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index 258c921..db009d8 100644
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -261,6 +261,10 @@
 int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 		__u64 start, __u64 len, get_extent_t *get_extent);
 int set_state_private(struct extent_io_tree *tree, u64 start, u64 private);
+void extent_cache_csums_dio(struct extent_io_tree *tree, u64 start, u32 csums[],
+			    int count);
+void extent_cache_csums(struct extent_io_tree *tree, struct bio *bio,
+			int bvec_index, u32 csums[], int count);
 int get_state_private(struct extent_io_tree *tree, u64 start, u64 *private);
 void set_page_extent_mapped(struct page *page);
 
diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index ad3cd86..18f12aa 100644
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -177,7 +177,8 @@
 				   struct inode *inode, struct bio *bio,
 				   u64 logical_offset, u32 *dst, int dio)
 {
-	u32 sum;
+	u32 sum[16];
+	int len;
 	struct bio_vec *bvec = bio->bi_io_vec;
 	int bio_index = 0;
 	u64 offset = 0;
@@ -186,7 +187,7 @@
 	u64 disk_bytenr;
 	u32 diff;
 	u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
-	int ret;
+	int count;
 	struct btrfs_path *path;
 	struct btrfs_csum_item *item = NULL;
 	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
@@ -214,10 +215,12 @@
 	if (dio)
 		offset = logical_offset;
 	while (bio_index < bio->bi_vcnt) {
+		len = min_t(int, ARRAY_SIZE(sum), bio->bi_vcnt - bio_index);
 		if (!dio)
 			offset = page_offset(bvec->bv_page) + bvec->bv_offset;
-		ret = btrfs_find_ordered_sum(inode, offset, disk_bytenr, &sum);
-		if (ret == 0)
+		count = btrfs_find_ordered_sum(inode, offset, disk_bytenr, sum,
+					       len);
+		if (count)
 			goto found;
 
 		if (!item || disk_bytenr < item_start_offset ||
@@ -230,10 +233,8 @@
 			item = btrfs_lookup_csum(NULL, root->fs_info->csum_root,
 						 path, disk_bytenr, 0);
 			if (IS_ERR(item)) {
-				ret = PTR_ERR(item);
-				if (ret == -ENOENT || ret == -EFBIG)
-					ret = 0;
-				sum = 0;
+				count = 1;
+				sum[0] = 0;
 				if (BTRFS_I(inode)->root->root_key.objectid ==
 				    BTRFS_DATA_RELOC_TREE_OBJECTID) {
 					set_extent_bits(io_tree, offset,
@@ -269,19 +270,29 @@
 		diff = disk_bytenr - item_start_offset;
 		diff = diff / root->sectorsize;
 		diff = diff * csum_size;
-
-		read_extent_buffer(path->nodes[0], &sum,
+		count = min_t(int, len, (item_last_offset - disk_bytenr) >>
+					inode->i_sb->s_blocksize_bits);
+		read_extent_buffer(path->nodes[0], sum,
 				   ((unsigned long)item) + diff,
-				   csum_size);
+				   csum_size * count);
 found:
-		if (dst)
-			*dst++ = sum;
-		else
-			set_state_private(io_tree, offset, sum);
-		disk_bytenr += bvec->bv_len;
-		offset += bvec->bv_len;
-		bio_index++;
-		bvec++;
+		if (dst) {
+			memcpy(dst, sum, count * csum_size);
+			dst += count;
+		} else {
+			if (dio)
+				extent_cache_csums_dio(io_tree, offset, sum,
+						       count);
+			else
+				extent_cache_csums(io_tree, bio, bio_index, sum,
+					    count);
+		}
+		while (count--) {
+			disk_bytenr += bvec->bv_len;
+			offset += bvec->bv_len;
+			bio_index++;
+			bvec++;
+		}
 	}
 	btrfs_free_path(path);
 	return 0;
diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c
index 005c45d..1ddd728 100644
--- a/fs/btrfs/ordered-data.c
+++ b/fs/btrfs/ordered-data.c
@@ -986,7 +986,7 @@
  * be reclaimed before their checksum is actually put into the btree
  */
 int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr,
-			   u32 *sum)
+			   u32 *sum, int len)
 {
 	struct btrfs_ordered_sum *ordered_sum;
 	struct btrfs_sector_sum *sector_sums;
@@ -995,22 +995,28 @@
 	unsigned long num_sectors;
 	unsigned long i;
 	u32 sectorsize = BTRFS_I(inode)->root->sectorsize;
-	int ret = 1;
+	int index = 0;
 
 	ordered = btrfs_lookup_ordered_extent(inode, offset);
 	if (!ordered)
-		return 1;
+		return 0;
 
 	spin_lock_irq(&tree->lock);
 	list_for_each_entry_reverse(ordered_sum, &ordered->list, list) {
-		if (disk_bytenr >= ordered_sum->bytenr) {
-			num_sectors = ordered_sum->len / sectorsize;
-			sector_sums = ordered_sum->sums;
-			for (i = 0; i < num_sectors; i++) {
+		if (disk_bytenr >= ordered_sum->bytenr &&
+		    disk_bytenr < ordered_sum->bytenr + ordered_sum->len) {
+			i = (disk_bytenr - ordered_sum->bytenr) >>
+			    inode->i_sb->s_blocksize_bits;
+			sector_sums = ordered_sum->sums + i;
+			num_sectors = ordered_sum->len >>
+				      inode->i_sb->s_blocksize_bits;
+			for (; i < num_sectors; i++) {
 				if (sector_sums[i].bytenr == disk_bytenr) {
-					*sum = sector_sums[i].sum;
-					ret = 0;
-					goto out;
+					sum[index] = sector_sums[i].sum;
+					index++;
+					if (index == len)
+						goto out;
+					disk_bytenr += sectorsize;
 				}
 			}
 		}
@@ -1018,7 +1024,7 @@
 out:
 	spin_unlock_irq(&tree->lock);
 	btrfs_put_ordered_extent(ordered);
-	return ret;
+	return index;
 }
 
 
diff --git a/fs/btrfs/ordered-data.h b/fs/btrfs/ordered-data.h
index 8eadfe4..58b0e3b 100644
--- a/fs/btrfs/ordered-data.h
+++ b/fs/btrfs/ordered-data.h
@@ -196,7 +196,8 @@
 							u64 len);
 int btrfs_ordered_update_i_size(struct inode *inode, u64 offset,
 				struct btrfs_ordered_extent *ordered);
-int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr, u32 *sum);
+int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr,
+			   u32 *sum, int len);
 int btrfs_run_ordered_operations(struct btrfs_trans_handle *trans,
 				 struct btrfs_root *root, int wait);
 void btrfs_add_ordered_operation(struct btrfs_trans_handle *trans,