Add inode item and backref in one insert, reducing cpu usage

diff --git a/ctree.c b/ctree.c
index 6357580..fa3c04c 100644 (file)
--- a/ctree.c
+++ b/ctree.c
@@ -2199,27 +2199,34 @@ int btrfs_extend_item(struct btrfs_trans_handle *trans,
  * Given a key and some data, insert an item into the tree.
  * This does all the path init required, making room in the tree if needed.
  */
-int btrfs_insert_empty_item(struct btrfs_trans_handle *trans,
+int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
                            struct btrfs_root *root,
                            struct btrfs_path *path,
-                           struct btrfs_key *cpu_key, u32 data_size)
+                           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_size = 0;
+       u32 total_data = 0;
        unsigned int data_end;
        struct btrfs_disk_key disk_key;
 
-       btrfs_cpu_key_to_disk(&disk_key, cpu_key);
+       for (i = 0; i < nr; i++) {
+               total_data += data_size[i];
+       }
 
        /* create a root if there isn't one */
        if (!root->node)
                BUG();
 
-       ret = btrfs_search_slot(trans, root, cpu_key, path, data_size, 1);
+       total_size = total_data + (nr - 1) * sizeof(struct btrfs_item);
+       ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1);
        if (ret == 0) {
                return -EEXIST;
        }
@@ -2233,10 +2240,10 @@ int btrfs_insert_empty_item(struct btrfs_trans_handle *trans,
        data_end = leaf_data_end(root, leaf);
 
        if (btrfs_leaf_free_space(root, leaf) <
-           sizeof(struct btrfs_item) + data_size) {
+           sizeof(struct btrfs_item) + total_size) {
                btrfs_print_leaf(root, leaf);
                printk("not enough freespace need %u have %d\n",
-                      data_size, btrfs_leaf_free_space(root, leaf));
+                      total_size, btrfs_leaf_free_space(root, leaf));
                BUG();
        }
 
@@ -2262,27 +2269,31 @@ int btrfs_insert_empty_item(struct btrfs_trans_handle *trans,
 
                        item = btrfs_item_nr(leaf, i);
                        ioff = btrfs_item_offset(leaf, item);
-                       btrfs_set_item_offset(leaf, item, ioff - data_size);
+                       btrfs_set_item_offset(leaf, item, ioff - total_data);
                }
 
                /* shift the items */
-               memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + 1),
+               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 - data_size, btrfs_leaf_data(leaf) +
+                             data_end - total_data, btrfs_leaf_data(leaf) +
                              data_end, old_data - data_end);
                data_end = old_data;
        }
 
        /* setup the item for the new data */
-       btrfs_set_item_key(leaf, &disk_key, slot);
-       item = btrfs_item_nr(leaf, slot);
-       btrfs_set_item_offset(leaf, item, data_end - data_size);
-       btrfs_set_item_size(leaf, item, data_size);
-       btrfs_set_header_nritems(leaf, nritems + 1);
+       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;

diff --git a/ctree.h b/ctree.h
index a219c23..113d38f 100644 (file)
--- a/ctree.h
+++ b/ctree.h
@@ -1009,9 +1009,20 @@ static inline int btrfs_del_item(struct btrfs_trans_handle *trans,
 
 int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root
                      *root, struct btrfs_key *key, void *data, u32 data_size);
-int btrfs_insert_empty_item(struct btrfs_trans_handle *trans, struct btrfs_root
-                           *root, struct btrfs_path *path, struct btrfs_key
-                           *cpu_key, u32 data_size);
+int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
+                            struct btrfs_root *root,
+                            struct btrfs_path *path,
+                            struct btrfs_key *cpu_key, u32 *data_size, int nr);
+
+static inline int btrfs_insert_empty_item(struct btrfs_trans_handle *trans,
+                                         struct btrfs_root *root,
+                                         struct btrfs_path *path,
+                                         struct btrfs_key *key,
+                                         u32 data_size)
+{
+       return btrfs_insert_empty_items(trans, root, path, key, &data_size, 1);
+}
+
 int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path);
 int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path);
 int btrfs_leaf_free_space(struct btrfs_root *root, struct extent_buffer *leaf);