Btrfs: Use a chunk of the key flags to record the item type.

Add (untested and simple) directory item code
Fix comp_keys to use the new key ordering
Add btrfs_insert_empty_item

Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 34 insertions, 17 deletions

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index ece8de7f38ef..7edfbd468042 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -107,14 +107,14 @@ static int comp_keys(struct btrfs_disk_key *disk, struct btrfs_key *k2)
                 return 1;
         if (k1.objectid < k2->objectid)
                 return -1;
-        if (k1.flags > k2->flags)
-                return 1;
-        if (k1.flags < k2->flags)
-                return -1;
         if (k1.offset > k2->offset)
                 return 1;
         if (k1.offset < k2->offset)
                 return -1;
+        if (k1.flags > k2->flags)
+                return 1;
+        if (k1.flags < k2->flags)
+                return -1;
         return 0;
 }
 
@@ -1122,8 +1122,8 @@ static int split_leaf(struct btrfs_root *root, struct btrfs_path *path,
  * 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_item(struct btrfs_root *root, struct btrfs_key *cpu_key,
-                          void *data, int data_size)
+int btrfs_insert_empty_item(struct btrfs_root *root, struct btrfs_path *path,
+                            struct btrfs_key *cpu_key, u32 data_size)
 {
         int ret = 0;
         int slot;
@@ -1132,7 +1132,6 @@ int btrfs_insert_item(struct btrfs_root *root, struct btrfs_key *cpu_key,
         struct btrfs_buffer *leaf_buf;
         u32 nritems;
         unsigned int data_end;
-        struct btrfs_path path;
         struct btrfs_disk_key disk_key;
 
         btrfs_cpu_key_to_disk(&disk_key, cpu_key);
@@ -1140,17 +1139,16 @@ int btrfs_insert_item(struct btrfs_root *root, struct btrfs_key *cpu_key,
         /* create a root if there isn't one */
         if (!root->node)
                 BUG();
-        btrfs_init_path(&path);
-        ret = btrfs_search_slot(root, cpu_key, &path, data_size, 1);
+        ret = btrfs_search_slot(root, cpu_key, path, data_size, 1);
         if (ret == 0) {
-                btrfs_release_path(root, &path);
+                btrfs_release_path(root, path);
                 return -EEXIST;
         }
         if (ret < 0)
                 goto out;
 
-        slot_orig = path.slots[0];
-        leaf_buf = path.nodes[0];
+        slot_orig = path->slots[0];
+        leaf_buf = path->nodes[0];
         leaf = &leaf_buf->leaf;
 
         nritems = btrfs_header_nritems(&leaf->header);
@@ -1160,7 +1158,7 @@ int btrfs_insert_item(struct btrfs_root *root, struct btrfs_key *cpu_key,
             sizeof(struct btrfs_item) + data_size)
                 BUG();
 
-        slot = path.slots[0];
+        slot = path->slots[0];
         BUG_ON(slot < 0);
         if (slot != nritems) {
                 int i;
@@ -1186,23 +1184,42 @@ int btrfs_insert_item(struct btrfs_root *root, struct btrfs_key *cpu_key,
                         data_end, old_data - data_end);
                 data_end = old_data;
         }
-        /* copy the new data in */
+        /* setup the item for the new data */
         memcpy(&leaf->items[slot].key, &disk_key,
                 sizeof(struct btrfs_disk_key));
         btrfs_set_item_offset(leaf->items + slot, data_end - data_size);
         btrfs_set_item_size(leaf->items + slot, data_size);
-        memcpy(btrfs_leaf_data(leaf) + data_end - data_size, data, data_size);
         btrfs_set_header_nritems(&leaf->header, nritems + 1);
 
         ret = 0;
         if (slot == 0)
-                ret = fixup_low_keys(root, &path, &disk_key, 1);
+                ret = fixup_low_keys(root, path, &disk_key, 1);
 
         BUG_ON(list_empty(&leaf_buf->dirty));
         if (btrfs_leaf_free_space(root, leaf) < 0)
                 BUG();
-        check_leaf(root, &path, 0);
+        check_leaf(root, path, 0);
 out:
+        return ret;
+}
+
+/*
+ * 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_item(struct btrfs_root *root, struct btrfs_key *cpu_key,
+                          void *data, u32 data_size)
+{
+        int ret = 0;
+        struct btrfs_path path;
+        u8 *ptr;
+
+        btrfs_init_path(&path);
+        ret = btrfs_insert_empty_item(root, &path, cpu_key, data_size);
+        if (!ret) {
+                ptr = btrfs_item_ptr(&path.nodes[0]->leaf, path.slots[0], u8);
+                memcpy(ptr, data, data_size);
+        }
         btrfs_release_path(root, &path);
         return ret;
 }