Btrfs: add del_ptr and insert_ptr modifications to the tree mod log
authorJan Schmidt <list.btrfs@jan-o-sch.net>
Sat, 26 May 2012 09:45:21 +0000 (11:45 +0200)
committerJan Schmidt <list.btrfs@jan-o-sch.net>
Wed, 30 May 2012 13:17:32 +0000 (15:17 +0200)
Record all relevant modifications to block pointers in the tree mod log so
that we can rewind them later on for backref walking.

Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
fs/btrfs/ctree.c

index 07c1a96aa4a83ebf43c55247dfe2514c6766c53e..69ce3f7deeef5f508e609ce151f1582d71e1989e 100644 (file)
@@ -38,7 +38,8 @@ static int balance_node_right(struct btrfs_trans_handle *trans,
                              struct extent_buffer *dst_buf,
                              struct extent_buffer *src_buf);
 static void del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
-                  struct btrfs_path *path, int level, int slot);
+                   struct btrfs_path *path, int level, int slot,
+                   int tree_mod_log);
 static void tree_mod_log_free_eb(struct btrfs_fs_info *fs_info,
                                 struct extent_buffer *eb);
 struct extent_buffer *read_old_tree_block(struct btrfs_root *root, u64 bytenr,
@@ -1465,7 +1466,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
                if (btrfs_header_nritems(right) == 0) {
                        clean_tree_block(trans, root, right);
                        btrfs_tree_unlock(right);
-                       del_ptr(trans, root, path, level + 1, pslot + 1);
+                       del_ptr(trans, root, path, level + 1, pslot + 1, 1);
                        root_sub_used(root, right->len);
                        btrfs_free_tree_block(trans, root, right, 0, 1);
                        free_extent_buffer_stale(right);
@@ -1509,7 +1510,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
        if (btrfs_header_nritems(mid) == 0) {
                clean_tree_block(trans, root, mid);
                btrfs_tree_unlock(mid);
-               del_ptr(trans, root, path, level + 1, pslot);
+               del_ptr(trans, root, path, level + 1, pslot, 1);
                root_sub_used(root, mid->len);
                btrfs_free_tree_block(trans, root, mid, 0, 1);
                free_extent_buffer_stale(mid);
@@ -2626,10 +2627,11 @@ static noinline int insert_new_root(struct btrfs_trans_handle *trans,
 static void insert_ptr(struct btrfs_trans_handle *trans,
                       struct btrfs_root *root, struct btrfs_path *path,
                       struct btrfs_disk_key *key, u64 bytenr,
-                      int slot, int level)
+                      int slot, int level, int tree_mod_log)
 {
        struct extent_buffer *lower;
        int nritems;
+       int ret;
 
        BUG_ON(!path->nodes[level]);
        btrfs_assert_tree_locked(path->nodes[level]);
@@ -2638,11 +2640,19 @@ static void insert_ptr(struct btrfs_trans_handle *trans,
        BUG_ON(slot > nritems);
        BUG_ON(nritems == BTRFS_NODEPTRS_PER_BLOCK(root));
        if (slot != nritems) {
+               if (tree_mod_log && level)
+                       tree_mod_log_eb_move(root->fs_info, lower, slot + 1,
+                                            slot, nritems - slot);
                memmove_extent_buffer(lower,
                              btrfs_node_key_ptr_offset(slot + 1),
                              btrfs_node_key_ptr_offset(slot),
                              (nritems - slot) * sizeof(struct btrfs_key_ptr));
        }
+       if (tree_mod_log && level) {
+               ret = tree_mod_log_insert_key(root->fs_info, lower, slot,
+                                             MOD_LOG_KEY_ADD);
+               BUG_ON(ret < 0);
+       }
        btrfs_set_node_key(lower, key, slot);
        btrfs_set_node_blockptr(lower, slot, bytenr);
        WARN_ON(trans->transid == 0);
@@ -2726,7 +2736,7 @@ static noinline int split_node(struct btrfs_trans_handle *trans,
        btrfs_mark_buffer_dirty(split);
 
        insert_ptr(trans, root, path, &disk_key, split->start,
-                  path->slots[level + 1] + 1, level + 1);
+                  path->slots[level + 1] + 1, level + 1, 1);
 
        if (path->slots[level] >= mid) {
                path->slots[level] -= mid;
@@ -3263,7 +3273,7 @@ static noinline void copy_for_split(struct btrfs_trans_handle *trans,
        btrfs_set_header_nritems(l, mid);
        btrfs_item_key(right, &disk_key, 0);
        insert_ptr(trans, root, path, &disk_key, right->start,
-                  path->slots[1] + 1, 1);
+                  path->slots[1] + 1, 1, 0);
 
        btrfs_mark_buffer_dirty(right);
        btrfs_mark_buffer_dirty(l);
@@ -3470,7 +3480,7 @@ again:
                if (mid <= slot) {
                        btrfs_set_header_nritems(right, 0);
                        insert_ptr(trans, root, path, &disk_key, right->start,
-                                  path->slots[1] + 1, 1);
+                                  path->slots[1] + 1, 1, 0);
                        btrfs_tree_unlock(path->nodes[0]);
                        free_extent_buffer(path->nodes[0]);
                        path->nodes[0] = right;
@@ -3479,7 +3489,7 @@ again:
                } else {
                        btrfs_set_header_nritems(right, 0);
                        insert_ptr(trans, root, path, &disk_key, right->start,
-                                         path->slots[1], 1);
+                                         path->slots[1], 1, 0);
                        btrfs_tree_unlock(path->nodes[0]);
                        free_extent_buffer(path->nodes[0]);
                        path->nodes[0] = right;
@@ -4191,19 +4201,31 @@ int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root
  * empty a node.
  */
 static void del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
-                   struct btrfs_path *path, int level, int slot)
+                   struct btrfs_path *path, int level, int slot,
+                   int tree_mod_log)
 {
        struct extent_buffer *parent = path->nodes[level];
        u32 nritems;
+       int ret;
 
        nritems = btrfs_header_nritems(parent);
        if (slot != nritems - 1) {
+               if (tree_mod_log && level)
+                       tree_mod_log_eb_move(root->fs_info, parent, slot,
+                                            slot + 1, nritems - slot - 1);
                memmove_extent_buffer(parent,
                              btrfs_node_key_ptr_offset(slot),
                              btrfs_node_key_ptr_offset(slot + 1),
                              sizeof(struct btrfs_key_ptr) *
                              (nritems - slot - 1));
        }
+
+       if (tree_mod_log && level) {
+               ret = tree_mod_log_insert_key(root->fs_info, parent, slot,
+                                             MOD_LOG_KEY_REMOVE);
+               BUG_ON(ret < 0);
+       }
+
        nritems--;
        btrfs_set_header_nritems(parent, nritems);
        if (nritems == 0 && parent == root->node) {
@@ -4235,7 +4257,7 @@ static noinline void btrfs_del_leaf(struct btrfs_trans_handle *trans,
                                    struct extent_buffer *leaf)
 {
        WARN_ON(btrfs_header_generation(leaf) != trans->transid);
-       del_ptr(trans, root, path, 1, path->slots[1]);
+       del_ptr(trans, root, path, 1, path->slots[1], 1);
 
        /*
         * btrfs_free_extent is expensive, we want to make sure we