1 files changed, 111 insertions, 3 deletions

diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index 3ebef871ee6c..df0447632dbd 100644
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -140,6 +140,7 @@ int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
         return ret;
 }
 
+
 int btrfs_lookup_bio_sums(struct btrfs_root *root, struct inode *inode,
                           struct bio *bio, u32 *dst)
 {
@@ -185,9 +186,16 @@ int btrfs_lookup_bio_sums(struct btrfs_root *root, struct inode *inode,
                                 if (ret == -ENOENT || ret == -EFBIG)
                                         ret = 0;
                                 sum = 0;
-                                printk("no csum found for inode %lu start "
-                                       "%llu\n", inode->i_ino,
-                                       (unsigned long long)offset);
+                                if (BTRFS_I(inode)->root->root_key.objectid ==
+                                    BTRFS_DATA_RELOC_TREE_OBJECTID) {
+                                        set_extent_bits(io_tree, offset,
+                                                offset + bvec->bv_len - 1,
+                                                EXTENT_NODATASUM, GFP_NOFS);
+                                } else {
+                                        printk("no csum found for inode %lu "
+                                               "start %llu\n", inode->i_ino,
+                                               (unsigned long long)offset);
+                                }
                                 item = NULL;
                                 btrfs_release_path(root, path);
                                 goto found;
@@ -228,6 +236,106 @@ found:
         return 0;
 }
 
+int btrfs_lookup_csums_range(struct btrfs_root *root, u64 start, u64 end,
+                             struct list_head *list)
+{
+        struct btrfs_key key;
+        struct btrfs_path *path;
+        struct extent_buffer *leaf;
+        struct btrfs_ordered_sum *sums;
+        struct btrfs_sector_sum *sector_sum;
+        struct btrfs_csum_item *item;
+        unsigned long offset;
+        int ret;
+        size_t size;
+        u64 csum_end;
+        u16 csum_size = btrfs_super_csum_size(&root->fs_info->super_copy);
+
+        path = btrfs_alloc_path();
+        BUG_ON(!path);
+
+        key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
+        key.offset = start;
+        key.type = BTRFS_EXTENT_CSUM_KEY;
+
+        ret = btrfs_search_slot(NULL, root->fs_info->csum_root,
+                                &key, path, 0, 0);
+        if (ret < 0)
+                goto fail;
+        if (ret > 0 && path->slots[0] > 0) {
+                leaf = path->nodes[0];
+                btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1);
+                if (key.objectid == BTRFS_EXTENT_CSUM_OBJECTID &&
+                    key.type == BTRFS_EXTENT_CSUM_KEY) {
+                        offset = (start - key.offset) >>
+                                 root->fs_info->sb->s_blocksize_bits;
+                        if (offset * csum_size <
+                            btrfs_item_size_nr(leaf, path->slots[0] - 1))
+                                path->slots[0]--;
+                }
+        }
+
+        while (start <= end) {
+                leaf = path->nodes[0];
+                if (path->slots[0] >= btrfs_header_nritems(leaf)) {
+                        ret = btrfs_next_leaf(root->fs_info->csum_root, path);
+                        if (ret < 0)
+                                goto fail;
+                        if (ret > 0)
+                                break;
+                        leaf = path->nodes[0];
+                }
+
+                btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
+                if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
+                    key.type != BTRFS_EXTENT_CSUM_KEY)
+                        break;
+
+                btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
+                if (key.offset > end)
+                        break;
+
+                if (key.offset > start)
+                        start = key.offset;
+
+                size = btrfs_item_size_nr(leaf, path->slots[0]);
+                csum_end = key.offset + (size / csum_size) * root->sectorsize;
+
+                size = min(csum_end, end + 1) - start;
+                sums = kzalloc(btrfs_ordered_sum_size(root, size), GFP_NOFS);
+                BUG_ON(!sums);
+
+                sector_sum = sums->sums;
+                sums->bytenr = start;
+                sums->len = size;
+
+                offset = (start - key.offset) >>
+                         root->fs_info->sb->s_blocksize_bits;
+                offset *= csum_size;
+
+                item = btrfs_item_ptr(path->nodes[0], path->slots[0],
+                                      struct btrfs_csum_item);
+                while (size > 0) {
+                        read_extent_buffer(path->nodes[0], &sector_sum->sum,
+                                           ((unsigned long)item) + offset,
+                                           csum_size);
+                        sector_sum->bytenr = start;
+
+                        size -= root->sectorsize;
+                        start += root->sectorsize;
+                        offset += csum_size;
+                        sector_sum++;
+                }
+                list_add_tail(&sums->list, list);
+
+                path->slots[0]++;
+        }
+        ret = 0;
+fail:
+        btrfs_free_path(path);
+        return ret;
+}
+
 int btrfs_csum_one_bio(struct btrfs_root *root, struct inode *inode,
                        struct bio *bio, u64 file_start, int contig)
 {