Btrfs: Add back pointers from extents to the btree or file referencing them

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

1 files changed, 311 insertions, 62 deletions

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 0f1ebdd4e925..32991f73e9db 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -17,6 +17,7 @@
  */
 
 #include <linux/sched.h>
+#include <linux/crc32c.h>
 #include "hash.h"
 #include "ctree.h"
 #include "disk-io.h"
@@ -89,7 +90,8 @@ static int cache_block_group(struct btrfs_root *root,
 
                 btrfs_item_key_to_cpu(leaf, &key, slot);
                 if (key.objectid < block_group->key.objectid) {
-                        if (key.objectid + key.offset > first_free)
+                        if (btrfs_key_type(&key) != BTRFS_EXTENT_REF_KEY &&
+                            key.objectid + key.offset > first_free)
                                 first_free = key.objectid + key.offset;
                         goto next;
                 }
@@ -353,7 +355,7 @@ found:
         return found_group;
 }
 
-static u64 hash_extent_ref(u64 root_objectid, u64 root_generation,
+static u64 hash_extent_ref(u64 root_objectid, u64 ref_generation,
                            u64 owner, u64 owner_offset)
 {
         u32 high_crc = ~(u32)0;
@@ -362,53 +364,149 @@ static u64 hash_extent_ref(u64 root_objectid, u64 root_generation,
 
         lenum = cpu_to_le64(root_objectid);
         high_crc = crc32c(high_crc, &lenum, sizeof(lenum));
-        lenum = cpu_to_le64(root_generation);
-        high_crc = crc32c(high_crc, &lenum, sizeof(lenum));
+        lenum = cpu_to_le64(ref_generation);
+        low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
 
+#if 0
         lenum = cpu_to_le64(owner);
         low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
-
         lenum = cpu_to_le64(owner_offset);
         low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
-
+#endif
         return ((u64)high_crc << 32) | (u64)low_crc;
 }
 
-int insert_extent_ref(struct btrfs_trans_handle *trans,
-                                struct btrfs_root *root,
-                                struct btrfs_path *path,
-                                u64 bytenr,
-                                u64 root_objectid, u64 root_generation,
-                                u64 owner, u64 owner_offset)
+static int match_extent_ref(struct extent_buffer *leaf,
+                            struct btrfs_extent_ref *disk_ref,
+                            struct btrfs_extent_ref *cpu_ref)
+{
+        int ret;
+        int len;
+
+        if (cpu_ref->objectid)
+                len = sizeof(*cpu_ref);
+        else
+                len = 2 * sizeof(u64);
+        ret = memcmp_extent_buffer(leaf, cpu_ref, (unsigned long)disk_ref,
+                                   len);
+        return ret == 0;
+}
+
+static int lookup_extent_backref(struct btrfs_trans_handle *trans,
+                                 struct btrfs_root *root,
+                                 struct btrfs_path *path, u64 bytenr,
+                                 u64 root_objectid, u64 ref_generation,
+                                 u64 owner, u64 owner_offset, int del)
 {
         u64 hash;
         struct btrfs_key key;
+        struct btrfs_key found_key;
         struct btrfs_extent_ref ref;
-        struct extent_buffer *l;
-        struct btrfs_extent_item *item;
+        struct extent_buffer *leaf;
+        struct btrfs_extent_ref *disk_ref;
+        int ret;
+        int ret2;
+
+        btrfs_set_stack_ref_root(&ref, root_objectid);
+        btrfs_set_stack_ref_generation(&ref, ref_generation);
+        btrfs_set_stack_ref_objectid(&ref, owner);
+        btrfs_set_stack_ref_offset(&ref, owner_offset);
+
+        hash = hash_extent_ref(root_objectid, ref_generation, owner,
+                               owner_offset);
+        key.offset = hash;
+        key.objectid = bytenr;
+        key.type = BTRFS_EXTENT_REF_KEY;
+
+        while (1) {
+                ret = btrfs_search_slot(trans, root, &key, path,
+                                        del ? -1 : 0, del);
+                if (ret < 0)
+                        goto out;
+                leaf = path->nodes[0];
+                if (ret != 0) {
+                        u32 nritems = btrfs_header_nritems(leaf);
+                        if (path->slots[0] >= nritems) {
+                                ret2 = btrfs_next_leaf(root, path);
+                                if (ret2)
+                                        goto out;
+                                leaf = path->nodes[0];
+                        }
+                        btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+                        if (found_key.objectid != bytenr ||
+                            found_key.type != BTRFS_EXTENT_REF_KEY)
+                                goto out;
+                        key.offset = found_key.offset;
+                        if (del) {
+                                btrfs_release_path(root, path);
+                                continue;
+                        }
+                }
+                disk_ref = btrfs_item_ptr(path->nodes[0],
+                                          path->slots[0],
+                                          struct btrfs_extent_ref);
+                if (match_extent_ref(path->nodes[0], disk_ref, &ref)) {
+                        ret = 0;
+                        goto out;
+                }
+                btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+                key.offset = found_key.offset + 1;
+                btrfs_release_path(root, path);
+        }
+out:
+        return ret;
+}
+
+int btrfs_insert_extent_backref(struct btrfs_trans_handle *trans,
+                                 struct btrfs_root *root,
+                                 struct btrfs_path *path, u64 bytenr,
+                                 u64 root_objectid, u64 ref_generation,
+                                 u64 owner, u64 owner_offset)
+{
+        u64 hash;
+        struct btrfs_key key;
+        struct btrfs_extent_ref ref;
+        struct btrfs_extent_ref *disk_ref;
         int ret;
 
         btrfs_set_stack_ref_root(&ref, root_objectid);
-        btrfs_set_stack_ref_generation(&ref, root_generation);
+        btrfs_set_stack_ref_generation(&ref, ref_generation);
         btrfs_set_stack_ref_objectid(&ref, owner);
         btrfs_set_stack_ref_offset(&ref, owner_offset);
 
-        ret = btrfs_name_hash(&ref, sizeof(ref), &hash);
+        hash = hash_extent_ref(root_objectid, ref_generation, owner,
+                               owner_offset);
         key.offset = hash;
         key.objectid = bytenr;
         key.type = BTRFS_EXTENT_REF_KEY;
 
         ret = btrfs_insert_empty_item(trans, root, path, &key, sizeof(ref));
         while (ret == -EEXIST) {
-
+                disk_ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
+                                          struct btrfs_extent_ref);
+                if (match_extent_ref(path->nodes[0], disk_ref, &ref))
+                        goto out;
+                key.offset++;
+                btrfs_release_path(root, path);
+                ret = btrfs_insert_empty_item(trans, root, path, &key,
+                                              sizeof(ref));
         }
-
+        if (ret)
+                goto out;
+        disk_ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
+                                  struct btrfs_extent_ref);
+        write_extent_buffer(path->nodes[0], &ref, (unsigned long)disk_ref,
+                            sizeof(ref));
+        btrfs_mark_buffer_dirty(path->nodes[0]);
+out:
+        btrfs_release_path(root, path);
+        return ret;
 }
 
 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
                                 struct btrfs_root *root,
                                 u64 bytenr, u64 num_bytes,
-                                u64 root_objectid, u64 root_generation,
+                                u64 root_objectid, u64 ref_generation,
                                 u64 owner, u64 owner_offset)
 {
         struct btrfs_path *path;
@@ -441,6 +539,11 @@ int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
         btrfs_mark_buffer_dirty(path->nodes[0]);
 
         btrfs_release_path(root->fs_info->extent_root, path);
+
+        ret = btrfs_insert_extent_backref(trans, root->fs_info->extent_root,
+                                          path, bytenr, root_objectid,
+                                          ref_generation, owner, owner_offset);
+        BUG_ON(ret);
         finish_current_insert(trans, root->fs_info->extent_root);
         del_pending_extents(trans, root->fs_info->extent_root);
 
@@ -489,10 +592,29 @@ out:
 }
 
 int btrfs_inc_root_ref(struct btrfs_trans_handle *trans,
-                       struct btrfs_root *root)
+                       struct btrfs_root *root, u64 owner_objectid)
 {
+        u64 generation;
+        u64 key_objectid;
+        u64 level;
+        u32 nritems;
+        struct btrfs_disk_key disk_key;
+
+        level = btrfs_header_level(root->node);
+        generation = trans->transid;
+        nritems = btrfs_header_nritems(root->node);
+        if (nritems > 0) {
+                if (level == 0)
+                        btrfs_item_key(root->node, &disk_key, 0);
+                else
+                        btrfs_node_key(root->node, &disk_key, 0);
+                key_objectid = btrfs_disk_key_objectid(&disk_key);
+        } else {
+                key_objectid = 0;
+        }
         return btrfs_inc_extent_ref(trans, root, root->node->start,
-                                    root->node->len);
+                                    root->node->len, owner_objectid,
+                                    generation, 0, 0);
 }
 
 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
@@ -506,7 +628,6 @@ int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
         int level;
         int ret;
         int faili;
-        int err;
 
         if (!root->ref_cows)
                 return 0;
@@ -528,7 +649,9 @@ int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
                         if (disk_bytenr == 0)
                                 continue;
                         ret = btrfs_inc_extent_ref(trans, root, disk_bytenr,
-                                    btrfs_file_extent_disk_num_bytes(buf, fi));
+                                    btrfs_file_extent_disk_num_bytes(buf, fi),
+                                    root->root_key.objectid, trans->transid,
+                                    key.objectid, key.offset);
                         if (ret) {
                                 faili = i;
                                 goto fail;
@@ -536,7 +659,9 @@ int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
                 } else {
                         bytenr = btrfs_node_blockptr(buf, i);
                         ret = btrfs_inc_extent_ref(trans, root, bytenr,
-                                           btrfs_level_size(root, level - 1));
+                                           btrfs_level_size(root, level - 1),
+                                           root->root_key.objectid,
+                                           trans->transid, 0, 0);
                         if (ret) {
                                 faili = i;
                                 goto fail;
@@ -546,6 +671,7 @@ int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
         return 0;
 fail:
         WARN_ON(1);
+#if 0
         for (i =0; i < faili; i++) {
                 if (level == 0) {
                         u64 disk_bytenr;
@@ -571,6 +697,7 @@ fail:
                         BUG_ON(err);
                 }
         }
+#endif
         return ret;
 }
 
@@ -809,18 +936,18 @@ int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
 static int finish_current_insert(struct btrfs_trans_handle *trans, struct
                                  btrfs_root *extent_root)
 {
+        u64 start;
+        u64 end;
+        struct btrfs_fs_info *info = extent_root->fs_info;
+        struct btrfs_path *path;
         struct btrfs_key ins;
         struct btrfs_extent_item extent_item;
         int ret;
         int err = 0;
-        u64 start;
-        u64 end;
-        struct btrfs_fs_info *info = extent_root->fs_info;
 
         btrfs_set_stack_extent_refs(&extent_item, 1);
         btrfs_set_key_type(&ins, BTRFS_EXTENT_ITEM_KEY);
-        btrfs_set_stack_extent_owner(&extent_item,
-                                     extent_root->root_key.objectid);
+        path = btrfs_alloc_path();
 
         while(1) {
                 ret = find_first_extent_bit(&info->extent_ins, 0, &start,
@@ -834,7 +961,12 @@ static int finish_current_insert(struct btrfs_trans_handle *trans, struct
                                         &extent_item, sizeof(extent_item));
                 clear_extent_bits(&info->extent_ins, start, end, EXTENT_LOCKED,
                                   GFP_NOFS);
+                err = btrfs_insert_extent_backref(trans, extent_root, path,
+                                          start, extent_root->root_key.objectid,
+                                          0, 0, 0);
+                BUG_ON(err);
         }
+        btrfs_free_path(path);
         return 0;
 }
 
@@ -871,7 +1003,9 @@ static int pin_down_bytes(struct btrfs_root *root, u64 bytenr, u32 num_bytes,
  * remove an extent from the root, returns 0 on success
  */
 static int __free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
-                         *root, u64 bytenr, u64 num_bytes, int pin,
+                         *root, u64 bytenr, u64 num_bytes,
+                         u64 root_objectid, u64 ref_generation,
+                         u64 owner_objectid, u64 owner_offset, int pin,
                          int mark_free)
 {
         struct btrfs_path *path;
@@ -891,6 +1025,24 @@ static int __free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
         if (!path)
                 return -ENOMEM;
 
+        if (ref_generation && owner_objectid == 0 && root_objectid == 3) {
+//printk("drop backref root %Lu gen %Lu byte %Lu\n", root_objectid, ref_generation, bytenr );
+        }
+        ret = lookup_extent_backref(trans, extent_root, path,
+                                    bytenr, root_objectid,
+                                    ref_generation,
+                                    owner_objectid, owner_offset, 1);
+        if (ret == 0) {
+                ret = btrfs_del_item(trans, extent_root, path);
+        } else {
+                btrfs_print_leaf(extent_root, path->nodes[0]);
+                WARN_ON(1);
+                printk("Unable to find ref byte nr %Lu root %Lu "
+                       " gen %Lu owner %Lu offset %Lu\n", bytenr,
+                       root_objectid, ref_generation, owner_objectid,
+                       owner_offset);
+        }
+        btrfs_release_path(extent_root, path);
         ret = btrfs_search_slot(trans, extent_root, &key, path, -1, 1);
         if (ret < 0)
                 return ret;
@@ -965,7 +1117,9 @@ static int del_pending_extents(struct btrfs_trans_handle *trans, struct
                 clear_extent_bits(pending_del, start, end, EXTENT_LOCKED,
                                   GFP_NOFS);
                 ret = __free_extent(trans, extent_root,
-                                     start, end + 1 - start, 0, 0);
+                                     start, end + 1 - start,
+                                     extent_root->root_key.objectid,
+                                     0, 0, 0, 0, 0);
                 if (ret)
                         err = ret;
         }
@@ -976,18 +1130,25 @@ static int del_pending_extents(struct btrfs_trans_handle *trans, struct
  * remove an extent from the root, returns 0 on success
  */
 int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
-                      *root, u64 bytenr, u64 num_bytes, int pin)
+                      *root, u64 bytenr, u64 num_bytes,
+                      u64 root_objectid, u64 ref_generation,
+                      u64 owner_objectid, u64 owner_offset, int pin)
 {
         struct btrfs_root *extent_root = root->fs_info->extent_root;
         int pending_ret;
         int ret;
 
         WARN_ON(num_bytes < root->sectorsize);
+        if (!root->ref_cows)
+                ref_generation = 0;
+
         if (root == extent_root) {
                 pin_down_bytes(root, bytenr, num_bytes, 1);
                 return 0;
         }
-        ret = __free_extent(trans, root, bytenr, num_bytes, pin, pin == 0);
+        ret = __free_extent(trans, root, bytenr, num_bytes, root_objectid,
+                            ref_generation, owner_objectid, owner_offset,
+                            pin, pin == 0);
         pending_ret = del_pending_extents(trans, root->fs_info->extent_root);
         return ret ? ret : pending_ret;
 }
@@ -1080,23 +1241,26 @@ check_failed:
         btrfs_item_key_to_cpu(l, &key, path->slots[0]);
 
         /*
-         * a rare case, go back one key if we hit a block group item
-         * instead of an extent item
+         * walk backwards to find the first extent item key
          */
-        if (btrfs_key_type(&key) != BTRFS_EXTENT_ITEM_KEY &&
-            key.objectid + key.offset >= search_start) {
-                ins->objectid = key.objectid;
-                ins->offset = key.offset - 1;
-                btrfs_release_path(root, path);
-                ret = btrfs_search_slot(trans, root, ins, path, 0, 0);
-                if (ret < 0)
-                        goto error;
-
-                if (path->slots[0] > 0) {
+        while(btrfs_key_type(&key) != BTRFS_EXTENT_ITEM_KEY) {
+                if (path->slots[0] == 0) {
+                        ret = btrfs_prev_leaf(root, path);
+                        if (ret != 0) {
+                                ret = btrfs_search_slot(trans, root, ins,
+                                                        path, 0, 0);
+                                if (ret < 0)
+                                        goto error;
+                                if (path->slots[0] > 0)
+                                        path->slots[0]--;
+                                break;
+                        }
+                } else {
                         path->slots[0]--;
                 }
+                l = path->nodes[0];
+                btrfs_item_key_to_cpu(l, &key, path->slots[0]);
         }
-
         while (1) {
                 l = path->nodes[0];
                 slot = path->slots[0];
@@ -1146,7 +1310,8 @@ check_failed:
                         }
                 }
                 if (btrfs_key_type(&key) != BTRFS_EXTENT_ITEM_KEY) {
-                        if (!start_found) {
+                        if (!start_found && btrfs_key_type(&key) ==
+                            BTRFS_BLOCK_GROUP_ITEM_KEY) {
                                 last_byte = key.objectid;
                                 start_found = 1;
                         }
@@ -1244,8 +1409,10 @@ error:
  * returns 0 if everything worked, non-zero otherwise.
  */
 int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
-                       struct btrfs_root *root, u64 owner,
-                       u64 num_bytes, u64 empty_size, u64 hint_byte,
+                       struct btrfs_root *root,
+                       u64 num_bytes, u64 root_objectid, u64 ref_generation,
+                       u64 owner, u64 owner_offset,
+                       u64 empty_size, u64 hint_byte,
                        u64 search_end, struct btrfs_key *ins, int data)
 {
         int ret;
@@ -1255,9 +1422,9 @@ int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
         struct btrfs_fs_info *info = root->fs_info;
         struct btrfs_root *extent_root = info->extent_root;
         struct btrfs_extent_item extent_item;
+        struct btrfs_path *path;
 
         btrfs_set_stack_extent_refs(&extent_item, 1);
-        btrfs_set_stack_extent_owner(&extent_item, owner);
 
         WARN_ON(num_bytes < root->sectorsize);
         ret = find_free_extent(trans, root, num_bytes, empty_size,
@@ -1296,8 +1463,16 @@ int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
 
         trans->alloc_exclude_start = 0;
         trans->alloc_exclude_nr = 0;
+        BUG_ON(ret);
+
+        path = btrfs_alloc_path();
+        BUG_ON(!path);
+        ret = btrfs_insert_extent_backref(trans, extent_root, path,
+                                          ins->objectid, root_objectid,
+                                          ref_generation, owner, owner_offset);
 
         BUG_ON(ret);
+        btrfs_free_path(path);
         finish_current_insert(trans, extent_root);
         pending_ret = del_pending_extents(trans, extent_root);
 
@@ -1321,15 +1496,43 @@ update_block:
  */
 struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
                                              struct btrfs_root *root,
-                                             u32 blocksize, u64 hint,
+                                             u32 blocksize,
+                                             u64 root_objectid, u64 hint,
+                                             u64 empty_size)
+{
+        u64 ref_generation;
+
+        if (root->ref_cows)
+                ref_generation = trans->transid;
+        else
+                ref_generation = 0;
+
+
+        return __btrfs_alloc_free_block(trans, root, blocksize, root_objectid,
+                                        ref_generation, 0, 0, hint, empty_size);
+}
+
+/*
+ * helper function to allocate a block for a given tree
+ * returns the tree buffer or NULL.
+ */
+struct extent_buffer *__btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
+                                             struct btrfs_root *root,
+                                             u32 blocksize,
+                                             u64 root_objectid,
+                                             u64 ref_generation,
+                                             u64 first_objectid,
+                                             int level,
+                                             u64 hint,
                                              u64 empty_size)
 {
         struct btrfs_key ins;
         int ret;
         struct extent_buffer *buf;
 
-        ret = btrfs_alloc_extent(trans, root, root->root_key.objectid,
-                                 blocksize, empty_size, hint,
+        ret = btrfs_alloc_extent(trans, root, blocksize,
+                                 root_objectid, ref_generation,
+                                 first_objectid, level, empty_size, hint,
                                  (u64)-1, &ins, 0);
         if (ret) {
                 BUG_ON(ret > 0);
@@ -1337,7 +1540,9 @@ struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
         }
         buf = btrfs_find_create_tree_block(root, ins.objectid, blocksize);
         if (!buf) {
-                btrfs_free_extent(trans, root, ins.objectid, blocksize, 0);
+                btrfs_free_extent(trans, root, ins.objectid, blocksize,
+                                  root->root_key.objectid, ref_generation,
+                                  0, 0, 0);
                 return ERR_PTR(-ENOMEM);
         }
         btrfs_set_buffer_uptodate(buf);
@@ -1355,6 +1560,8 @@ struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
 static int drop_leaf_ref(struct btrfs_trans_handle *trans,
                          struct btrfs_root *root, struct extent_buffer *leaf)
 {
+        u64 leaf_owner;
+        u64 leaf_generation;
         struct btrfs_key key;
         struct btrfs_file_extent_item *fi;
         int i;
@@ -1363,6 +1570,9 @@ static int drop_leaf_ref(struct btrfs_trans_handle *trans,
 
         BUG_ON(!btrfs_is_leaf(leaf));
         nritems = btrfs_header_nritems(leaf);
+        leaf_owner = btrfs_header_owner(leaf);
+        leaf_generation = btrfs_header_generation(leaf);
+
         for (i = 0; i < nritems; i++) {
                 u64 disk_bytenr;
 
@@ -1381,7 +1591,9 @@ static int drop_leaf_ref(struct btrfs_trans_handle *trans,
                 if (disk_bytenr == 0)
                         continue;
                 ret = btrfs_free_extent(trans, root, disk_bytenr,
-                                btrfs_file_extent_disk_num_bytes(leaf, fi), 0);
+                                btrfs_file_extent_disk_num_bytes(leaf, fi),
+                                leaf_owner, leaf_generation,
+                                key.objectid, key.offset, 0);
                 BUG_ON(ret);
         }
         return 0;
@@ -1423,9 +1635,12 @@ static void reada_walk_down(struct btrfs_root *root,
 static int walk_down_tree(struct btrfs_trans_handle *trans, struct btrfs_root
                           *root, struct btrfs_path *path, int *level)
 {
+        u64 root_owner;
+        u64 root_gen;
+        u64 bytenr;
         struct extent_buffer *next;
         struct extent_buffer *cur;
-        u64 bytenr;
+        struct extent_buffer *parent;
         u32 blocksize;
         int ret;
         u32 refs;
@@ -1466,9 +1681,13 @@ static int walk_down_tree(struct btrfs_trans_handle *trans, struct btrfs_root
                 ret = lookup_extent_ref(trans, root, bytenr, blocksize, &refs);
                 BUG_ON(ret);
                 if (refs != 1) {
+                        parent = path->nodes[*level];
+                        root_owner = btrfs_header_owner(parent);
+                        root_gen = btrfs_header_generation(parent);
                         path->slots[*level]++;
                         ret = btrfs_free_extent(trans, root, bytenr,
-                                                blocksize, 1);
+                                                blocksize, root_owner,
+                                                root_gen, 0, 0, 1);
                         BUG_ON(ret);
                         continue;
                 }
@@ -1484,10 +1703,16 @@ static int walk_down_tree(struct btrfs_trans_handle *trans, struct btrfs_root
                                                 blocksize, &refs);
                         BUG_ON(ret);
                         if (refs != 1) {
+                                parent = path->nodes[*level];
+                                root_owner = btrfs_header_owner(parent);
+                                root_gen = btrfs_header_generation(parent);
+
                                 path->slots[*level]++;
                                 free_extent_buffer(next);
-                                ret = btrfs_free_extent(trans, root,
-                                                        bytenr, blocksize, 1);
+                                ret = btrfs_free_extent(trans, root, bytenr,
+                                                        blocksize,
+                                                        root_owner,
+                                                        root_gen, 0, 0, 1);
                                 BUG_ON(ret);
                                 continue;
                         }
@@ -1502,8 +1727,19 @@ static int walk_down_tree(struct btrfs_trans_handle *trans, struct btrfs_root
 out:
         WARN_ON(*level < 0);
         WARN_ON(*level >= BTRFS_MAX_LEVEL);
+
+        if (path->nodes[*level] == root->node) {
+                root_owner = root->root_key.objectid;
+                parent = path->nodes[*level];
+        } else {
+                parent = path->nodes[*level + 1];
+                root_owner = btrfs_header_owner(parent);
+        }
+
+        root_gen = btrfs_header_generation(parent);
         ret = btrfs_free_extent(trans, root, path->nodes[*level]->start,
-                                path->nodes[*level]->len, 1);
+                                path->nodes[*level]->len,
+                                root_owner, root_gen, 0, 0, 1);
         free_extent_buffer(path->nodes[*level]);
         path->nodes[*level] = NULL;
         *level += 1;
@@ -1519,10 +1755,12 @@ out:
 static int walk_up_tree(struct btrfs_trans_handle *trans, struct btrfs_root
                         *root, struct btrfs_path *path, int *level)
 {
+        u64 root_owner;
+        u64 root_gen;
+        struct btrfs_root_item *root_item = &root->root_item;
         int i;
         int slot;
         int ret;
-        struct btrfs_root_item *root_item = &root->root_item;
 
         for(i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
                 slot = path->slots[i];
@@ -1539,9 +1777,20 @@ static int walk_up_tree(struct btrfs_trans_handle *trans, struct btrfs_root
                         root_item->drop_level = i;
                         return 0;
                 } else {
+                        if (path->nodes[*level] == root->node) {
+                                root_owner = root->root_key.objectid;
+                                root_gen =
+                                   btrfs_header_generation(path->nodes[*level]);
+                        } else {
+                                struct extent_buffer *node;
+                                node = path->nodes[*level + 1];
+                                root_owner = btrfs_header_owner(node);
+                                root_gen = btrfs_header_generation(node);
+                        }
                         ret = btrfs_free_extent(trans, root,
                                                 path->nodes[*level]->start,
-                                                path->nodes[*level]->len, 1);
+                                                path->nodes[*level]->len,
+                                                root_owner, root_gen, 0, 0, 1);
                         BUG_ON(ret);
                         free_extent_buffer(path->nodes[*level]);
                         path->nodes[*level] = NULL;