1 files changed, 170 insertions, 0 deletions

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index ac61c50a3311..8bb452456d90 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -431,6 +431,25 @@ static int comp_keys(struct btrfs_disk_key *disk, struct btrfs_key *k2)
         return 0;
 }
 
+/*
+ * same as comp_keys only with two btrfs_key's
+ */
+static int comp_cpu_keys(struct btrfs_key *k1, struct btrfs_key *k2)
+{
+        if (k1->objectid > k2->objectid)
+                return 1;
+        if (k1->objectid < k2->objectid)
+                return -1;
+        if (k1->type > k2->type)
+                return 1;
+        if (k1->type < k2->type)
+                return -1;
+        if (k1->offset > k2->offset)
+                return 1;
+        if (k1->offset < k2->offset)
+                return -1;
+        return 0;
+}
 
 /*
  * this is used by the defrag code to go through all the
@@ -3002,6 +3021,157 @@ int btrfs_extend_item(struct btrfs_trans_handle *trans,
 /*
  * Given a key and some data, insert items into the tree.
  * This does all the path init required, making room in the tree if needed.
+ * Returns the number of keys that were inserted.
+ */
+int btrfs_insert_some_items(struct btrfs_trans_handle *trans,
+                            struct btrfs_root *root,
+                            struct btrfs_path *path,
+                            struct btrfs_key *cpu_key, u32 *data_size,
+                            int nr)
+{
+        struct extent_buffer *leaf;
+        struct btrfs_item *item;
+        int ret = 0;
+        int slot;
+        int slot_orig;
+        int i;
+        u32 nritems;
+        u32 total_data = 0;
+        u32 total_size = 0;
+        unsigned int data_end;
+        struct btrfs_disk_key disk_key;
+        struct btrfs_key found_key;
+
+        found_key.objectid = 0;
+        nr = min_t(int, nr, BTRFS_NODEPTRS_PER_BLOCK(root));
+
+        for (i = 0; i < nr; i++)
+                total_data += data_size[i];
+
+        total_data = min_t(u32, total_data, BTRFS_LEAF_DATA_SIZE(root));
+        total_size = total_data + (nr * sizeof(struct btrfs_item));
+        ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1);
+        if (ret == 0)
+                return -EEXIST;
+        if (ret < 0)
+                goto out;
+
+        slot_orig = path->slots[0];
+        leaf = path->nodes[0];
+
+        nritems = btrfs_header_nritems(leaf);
+        data_end = leaf_data_end(root, leaf);
+
+        if (btrfs_leaf_free_space(root, leaf) < total_size) {
+                for (i = nr; i >= 0; i--) {
+                        total_data -= data_size[i];
+                        total_size -= data_size[i] + sizeof(struct btrfs_item);
+                        if (total_size < btrfs_leaf_free_space(root, leaf))
+                                break;
+                }
+                nr = i;
+        }
+
+        slot = path->slots[0];
+        BUG_ON(slot < 0);
+
+        if (slot != nritems) {
+                unsigned int old_data = btrfs_item_end_nr(leaf, slot);
+
+                item = btrfs_item_nr(leaf, slot);
+                btrfs_item_key_to_cpu(leaf, &found_key, slot);
+
+                /* figure out how many keys we can insert in here */
+                total_data = data_size[0];
+                for (i = 1; i < nr; i++) {
+                        if (comp_cpu_keys(&found_key, cpu_key + i) <= 0)
+                                break;
+                        total_data += data_size[i];
+                }
+                nr = i;
+
+                if (old_data < data_end) {
+                        btrfs_print_leaf(root, leaf);
+                        printk("slot %d old_data %d data_end %d\n",
+                               slot, old_data, data_end);
+                        BUG_ON(1);
+                }
+                /*
+                 * item0..itemN ... dataN.offset..dataN.size .. data0.size
+                 */
+                /* first correct the data pointers */
+                WARN_ON(leaf->map_token);
+                for (i = slot; i < nritems; i++) {
+                        u32 ioff;
+
+                        item = btrfs_item_nr(leaf, i);
+                        if (!leaf->map_token) {
+                                map_extent_buffer(leaf, (unsigned long)item,
+                                        sizeof(struct btrfs_item),
+                                        &leaf->map_token, &leaf->kaddr,
+                                        &leaf->map_start, &leaf->map_len,
+                                        KM_USER1);
+                        }
+
+                        ioff = btrfs_item_offset(leaf, item);
+                        btrfs_set_item_offset(leaf, item, ioff - total_data);
+                }
+                if (leaf->map_token) {
+                        unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
+                        leaf->map_token = NULL;
+                }
+
+                /* shift the items */
+                memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr),
+                              btrfs_item_nr_offset(slot),
+                              (nritems - slot) * sizeof(struct btrfs_item));
+
+                /* shift the data */
+                memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
+                              data_end - total_data, btrfs_leaf_data(leaf) +
+                              data_end, old_data - data_end);
+                data_end = old_data;
+        } else {
+                /*
+                 * this sucks but it has to be done, if we are inserting at
+                 * the end of the leaf only insert 1 of the items, since we
+                 * have no way of knowing whats on the next leaf and we'd have
+                 * to drop our current locks to figure it out
+                 */
+                nr = 1;
+        }
+
+        /* setup the item for the new data */
+        for (i = 0; i < nr; i++) {
+                btrfs_cpu_key_to_disk(&disk_key, cpu_key + i);
+                btrfs_set_item_key(leaf, &disk_key, slot + i);
+                item = btrfs_item_nr(leaf, slot + i);
+                btrfs_set_item_offset(leaf, item, data_end - data_size[i]);
+                data_end -= data_size[i];
+                btrfs_set_item_size(leaf, item, data_size[i]);
+        }
+        btrfs_set_header_nritems(leaf, nritems + nr);
+        btrfs_mark_buffer_dirty(leaf);
+
+        ret = 0;
+        if (slot == 0) {
+                btrfs_cpu_key_to_disk(&disk_key, cpu_key);
+                ret = fixup_low_keys(trans, root, path, &disk_key, 1);
+        }
+
+        if (btrfs_leaf_free_space(root, leaf) < 0) {
+                btrfs_print_leaf(root, leaf);
+                BUG();
+        }
+out:
+        if (!ret)
+                ret = nr;
+        return ret;
+}
+
+/*
+ * Given a key and some data, insert items into the tree.
+ * This does all the path init required, making room in the tree if needed.
  */
 int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
                             struct btrfs_root *root,