Btrfs-progs: check, ability to detect and fix outdated snapshot root items
[platform/upstream/btrfs-progs.git] / extent-tree.c
index 63b1a38..080f30d 100644 (file)
@@ -18,6 +18,7 @@
 
 #include <stdio.h>
 #include <stdlib.h>
+#include <stdint.h>
 #include "kerncompat.h"
 #include "radix-tree.h"
 #include "ctree.h"
@@ -27,6 +28,8 @@
 #include "crc32c.h"
 #include "volumes.h"
 #include "free-space-cache.h"
+#include "math.h"
+#include "utils.h"
 
 #define PENDING_EXTENT_INSERT 0
 #define PENDING_EXTENT_DELETE 1
@@ -55,6 +58,9 @@ static int finish_current_insert(struct btrfs_trans_handle *trans, struct
                                 btrfs_root *extent_root);
 static int del_pending_extents(struct btrfs_trans_handle *trans, struct
                               btrfs_root *extent_root);
+static struct btrfs_block_group_cache *
+btrfs_find_block_group(struct btrfs_root *root, struct btrfs_block_group_cache
+                      *hint, u64 search_start, int data, int owner);
 
 static int remove_sb_from_cache(struct btrfs_root *root,
                                struct btrfs_block_group_cache *cache)
@@ -300,15 +306,6 @@ wrapped:
        goto again;
 }
 
-static u64 div_factor(u64 num, int factor)
-{
-       if (factor == 10)
-               return num;
-       num *= factor;
-       num /= 10;
-       return num;
-}
-
 static int block_group_state_bits(u64 flags)
 {
        int bits = 0;
@@ -321,10 +318,9 @@ static int block_group_state_bits(u64 flags)
        return bits;
 }
 
-struct btrfs_block_group_cache *btrfs_find_block_group(struct btrfs_root *root,
-                                                struct btrfs_block_group_cache
-                                                *hint, u64 search_start,
-                                                int data, int owner)
+static struct btrfs_block_group_cache *
+btrfs_find_block_group(struct btrfs_root *root, struct btrfs_block_group_cache
+                      *hint, u64 search_start, int data, int owner)
 {
        struct btrfs_block_group_cache *cache;
        struct extent_io_tree *block_group_cache;
@@ -567,7 +563,7 @@ static int convert_extent_item_v0(struct btrfs_trans_handle *trans,
                        break;
                }
        }
-       btrfs_release_path(root, path);
+       btrfs_release_path(path);
 
        if (owner < BTRFS_FIRST_FREE_OBJECTID)
                new_size += sizeof(*bi);
@@ -674,7 +670,7 @@ again:
                        return 0;
 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
                key.type = BTRFS_EXTENT_REF_V0_KEY;
-               btrfs_release_path(root, path);
+               btrfs_release_path(path);
                ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
                if (ret < 0) {
                        err = ret;
@@ -712,7 +708,7 @@ again:
                if (match_extent_data_ref(leaf, ref, root_objectid,
                                          owner, offset)) {
                        if (recow) {
-                               btrfs_release_path(root, path);
+                               btrfs_release_path(path);
                                goto again;
                        }
                        err = 0;
@@ -773,7 +769,7 @@ static noinline int insert_extent_data_ref(struct btrfs_trans_handle *trans,
                        if (match_extent_data_ref(leaf, ref, root_objectid,
                                                  owner, offset))
                                break;
-                       btrfs_release_path(root, path);
+                       btrfs_release_path(path);
 
                        key.offset++;
                        ret = btrfs_insert_empty_item(trans, root, path, &key,
@@ -800,7 +796,7 @@ static noinline int insert_extent_data_ref(struct btrfs_trans_handle *trans,
        btrfs_mark_buffer_dirty(leaf);
        ret = 0;
 fail:
-       btrfs_release_path(root, path);
+       btrfs_release_path(path);
        return ret;
 }
 
@@ -926,7 +922,7 @@ static noinline int lookup_tree_block_ref(struct btrfs_trans_handle *trans,
                ret = -ENOENT;
 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
        if (ret == -ENOENT && parent) {
-               btrfs_release_path(root, path);
+               btrfs_release_path(path);
                key.type = BTRFS_EXTENT_REF_V0_KEY;
                ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
                if (ret > 0)
@@ -956,44 +952,25 @@ static noinline int insert_tree_block_ref(struct btrfs_trans_handle *trans,
 
        ret = btrfs_insert_empty_item(trans, root, path, &key, 0);
 
-       btrfs_release_path(root, path);
+       btrfs_release_path(path);
        return ret;
 }
 
 static inline int extent_ref_type(u64 parent, u64 owner)
 {
+       int type;
        if (owner < BTRFS_FIRST_FREE_OBJECTID) {
                if (parent > 0)
-                       return BTRFS_SHARED_BLOCK_REF_KEY;
+                       type = BTRFS_SHARED_BLOCK_REF_KEY;
                else
-                       return BTRFS_TREE_BLOCK_REF_KEY;
+                       type = BTRFS_TREE_BLOCK_REF_KEY;
        } else {
                if (parent > 0)
-                       return BTRFS_SHARED_DATA_REF_KEY;
+                       type = BTRFS_SHARED_DATA_REF_KEY;
                else
-                       return BTRFS_EXTENT_DATA_REF_KEY;
+                       type = BTRFS_EXTENT_DATA_REF_KEY;
        }
-}
-
-static int find_next_key(struct btrfs_path *path, struct btrfs_key *key)
-
-{
-       int level;
-       for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
-               if (!path->nodes[level])
-                       break;
-               if (path->slots[level] + 1 >=
-                   btrfs_header_nritems(path->nodes[level]))
-                       continue;
-               if (level == 0)
-                       btrfs_item_key_to_cpu(path->nodes[level], key,
-                                             path->slots[level] + 1);
-               else
-                       btrfs_node_key_to_cpu(path->nodes[level], key,
-                                             path->slots[level] + 1);
-               return 0;
-       }
-       return 1;
+       return type;
 }
 
 static int lookup_inline_extent_backref(struct btrfs_trans_handle *trans,
@@ -1064,6 +1041,7 @@ again:
                if (ret) {
                        key.type = BTRFS_EXTENT_ITEM_KEY;
                        key.offset = num_bytes;
+                       btrfs_release_path(path);
                        goto again;
                }
        }
@@ -1263,7 +1241,7 @@ static int lookup_extent_backref(struct btrfs_trans_handle *trans,
        if (ret != -ENOENT)
                return ret;
 
-       btrfs_release_path(root, path);
+       btrfs_release_path(path);
        *ref_ret = NULL;
 
        if (owner < BTRFS_FIRST_FREE_OBJECTID) {
@@ -1420,7 +1398,6 @@ int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
                return -ENOMEM;
 
        path->reada = 1;
-       path->leave_spinning = 1;
 
        ret = insert_inline_extent_backref(trans, root->fs_info->extent_root,
                                           path, bytenr, num_bytes, parent,
@@ -1439,10 +1416,9 @@ int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
        btrfs_set_extent_refs(leaf, item, refs + 1);
 
        btrfs_mark_buffer_dirty(leaf);
-       btrfs_release_path(root->fs_info->extent_root, path);
+       btrfs_release_path(path);
 
        path->reada = 1;
-       path->leave_spinning = 1;
 
        /* now insert the actual backref */
        ret = insert_extent_backref(trans, root->fs_info->extent_root,
@@ -1487,6 +1463,8 @@ int btrfs_lookup_extent_info(struct btrfs_trans_handle *trans,
        }
 
        path = btrfs_alloc_path();
+       if (!path)
+               return -ENOMEM;
        path->reada = 1;
 
        key.objectid = bytenr;
@@ -1509,17 +1487,18 @@ again:
         * to make sure.
         */
        if (ret > 0 && metadata) {
-               if (path->slots) {
+               if (path->slots[0]) {
                        path->slots[0]--;
                        btrfs_item_key_to_cpu(path->nodes[0], &key,
                                              path->slots[0]);
                        if (key.objectid == bytenr &&
-                           key.type == BTRFS_METADATA_ITEM_KEY)
+                           key.type == BTRFS_EXTENT_ITEM_KEY &&
+                           key.offset == root->leafsize)
                                ret = 0;
                }
 
                if (ret) {
-                       btrfs_release_path(root, path);
+                       btrfs_release_path(path);
                        key.type = BTRFS_EXTENT_ITEM_KEY;
                        key.offset = root->leafsize;
                        metadata = 0;
@@ -1559,7 +1538,7 @@ again:
                *flags = extent_flags;
 out:
        btrfs_free_path(path);
-       return 0;
+       return ret;
 }
 
 int btrfs_set_block_flags(struct btrfs_trans_handle *trans,
@@ -1577,6 +1556,8 @@ int btrfs_set_block_flags(struct btrfs_trans_handle *trans,
                                  BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA);
 
        path = btrfs_alloc_path();
+       if (!path)
+               return -ENOMEM;
        path->reada = 1;
 
        key.objectid = bytenr;
@@ -1596,7 +1577,7 @@ again:
 
        if (ret > 0 && skinny_metadata) {
                skinny_metadata = 0;
-               if (path->slots[0]--) {
+               if (path->slots[0]) {
                        path->slots[0]--;
                        btrfs_item_key_to_cpu(path->nodes[0], &key,
                                              path->slots[0]);
@@ -1606,7 +1587,7 @@ again:
                                ret = 0;
                }
                if (ret) {
-                       btrfs_release_path(root, path);
+                       btrfs_release_path(path);
                        key.offset = root->leafsize;
                        key.type = BTRFS_EXTENT_ITEM_KEY;
                        goto again;
@@ -1752,7 +1733,7 @@ static int write_one_cache_group(struct btrfs_trans_handle *trans,
        bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
        write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item));
        btrfs_mark_buffer_dirty(leaf);
-       btrfs_release_path(extent_root, path);
+       btrfs_release_path(path);
 fail:
        finish_current_insert(trans, extent_root);
        pending_ret = del_pending_extents(trans, extent_root);
@@ -2015,25 +1996,6 @@ next:
        return 0;
 }
 
-int btrfs_copy_pinned(struct btrfs_root *root, struct extent_io_tree *copy)
-{
-       u64 last = 0;
-       u64 start;
-       u64 end;
-       struct extent_io_tree *pinned_extents = &root->fs_info->pinned_extents;
-       int ret;
-
-       while(1) {
-               ret = find_first_extent_bit(pinned_extents, last,
-                                           &start, &end, EXTENT_DIRTY);
-               if (ret)
-                       break;
-               set_extent_dirty(copy, start, end, GFP_NOFS);
-               last = end + 1;
-       }
-       return 0;
-}
-
 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
                               struct btrfs_root *root,
                               struct extent_io_tree *unpin)
@@ -2078,7 +2040,6 @@ static int finish_current_insert(struct btrfs_trans_handle *trans,
        u64 end;
        u64 priv;
        struct btrfs_fs_info *info = extent_root->fs_info;
-       struct btrfs_path *path;
        struct pending_extent_op *extent_op;
        struct btrfs_key key;
        int ret;
@@ -2086,8 +2047,6 @@ static int finish_current_insert(struct btrfs_trans_handle *trans,
                btrfs_fs_incompat(extent_root->fs_info,
                                  BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA);
 
-       path = btrfs_alloc_path();
-
        while(1) {
                ret = find_first_extent_bit(&info->extent_ins, 0, &start,
                                            &end, EXTENT_LOCKED);
@@ -2113,6 +2072,7 @@ static int finish_current_insert(struct btrfs_trans_handle *trans,
                                                extent_op->flags,
                                                &extent_op->key,
                                                extent_op->level, &key);
+                       BUG_ON(ret);
                } else {
                        BUG_ON(1);
                }
@@ -2121,7 +2081,6 @@ static int finish_current_insert(struct btrfs_trans_handle *trans,
                                  GFP_NOFS);
                kfree(extent_op);
        }
-       btrfs_free_path(path);
        return 0;
 }
 
@@ -2214,7 +2173,6 @@ static int __free_extent(struct btrfs_trans_handle *trans,
                return -ENOMEM;
 
        path->reada = 1;
-       path->leave_spinning = 1;
 
        is_data = owner_objectid >= BTRFS_FIRST_FREE_OBJECTID;
        if (is_data)
@@ -2257,8 +2215,7 @@ static int __free_extent(struct btrfs_trans_handle *trans,
                                                    NULL, refs_to_drop,
                                                    is_data);
                        BUG_ON(ret);
-                       btrfs_release_path(extent_root, path);
-                       path->leave_spinning = 1;
+                       btrfs_release_path(path);
 
                        key.objectid = bytenr;
 
@@ -2285,7 +2242,7 @@ static int __free_extent(struct btrfs_trans_handle *trans,
 
                        if (ret > 0 && skinny_metadata) {
                                skinny_metadata = 0;
-                               btrfs_release_path(extent_root, path);
+                               btrfs_release_path(path);
                                key.type = BTRFS_EXTENT_ITEM_KEY;
                                key.offset = num_bytes;
                                ret = btrfs_search_slot(trans, extent_root,
@@ -2322,8 +2279,7 @@ static int __free_extent(struct btrfs_trans_handle *trans,
                                             owner_objectid, 0);
                BUG_ON(ret < 0);
 
-               btrfs_release_path(extent_root, path);
-               path->leave_spinning = 1;
+               btrfs_release_path(path);
 
                key.objectid = bytenr;
                key.type = BTRFS_EXTENT_ITEM_KEY;
@@ -2410,7 +2366,7 @@ static int __free_extent(struct btrfs_trans_handle *trans,
                ret = btrfs_del_items(trans, extent_root, path, path->slots[0],
                                      num_to_del);
                BUG_ON(ret);
-               btrfs_release_path(extent_root, path);
+               btrfs_release_path(path);
 
                if (is_data) {
                        ret = btrfs_del_csums(trans, root, bytenr, num_bytes);
@@ -2648,11 +2604,11 @@ error:
        return ret;
 }
 
-static int btrfs_reserve_extent(struct btrfs_trans_handle *trans,
-                               struct btrfs_root *root,
-                               u64 num_bytes, u64 empty_size,
-                               u64 hint_byte, u64 search_end,
-                               struct btrfs_key *ins, int data)
+int btrfs_reserve_extent(struct btrfs_trans_handle *trans,
+                        struct btrfs_root *root,
+                        u64 num_bytes, u64 empty_size,
+                        u64 hint_byte, u64 search_end,
+                        struct btrfs_key *ins, int data)
 {
        int ret;
        u64 search_start = 0;
@@ -2730,7 +2686,6 @@ static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
        path = btrfs_alloc_path();
        BUG_ON(!path);
 
-       path->leave_spinning = 1;
        ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path,
                                      ins, size);
        BUG_ON(ret);
@@ -2760,7 +2715,7 @@ static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
 
        ret = update_block_group(trans, root, ins->objectid, root->leafsize,
                                 1, 0);
-       return 0;
+       return ret;
 }
 
 static int alloc_tree_block(struct btrfs_trans_handle *trans,
@@ -3109,7 +3064,7 @@ int btrfs_free_block_groups(struct btrfs_fs_info *info)
                        break;
                ret = get_state_private(&info->block_group_cache, start, &ptr);
                if (!ret) {
-                       cache = (struct btrfs_block_group_cache *)ptr;
+                       cache = u64_to_ptr(ptr);
                        if (cache->free_space_ctl) {
                                btrfs_remove_free_space_cache(cache);
                                kfree(cache->free_space_ctl);
@@ -3137,8 +3092,8 @@ int btrfs_free_block_groups(struct btrfs_fs_info *info)
        return 0;
 }
 
-int find_first_block_group(struct btrfs_root *root, struct btrfs_path *path,
-                          struct btrfs_key *key)
+static int find_first_block_group(struct btrfs_root *root,
+               struct btrfs_path *path, struct btrfs_key *key)
 {
        int ret;
        struct btrfs_key found_key;
@@ -3218,7 +3173,7 @@ int btrfs_read_block_groups(struct btrfs_root *root)
                cache->cached = 0;
                cache->pinned = 0;
                key.objectid = found_key.objectid + found_key.offset;
-               btrfs_release_path(root, path);
+               btrfs_release_path(path);
                cache->flags = btrfs_block_group_flags(&cache->item);
                bit = 0;
                if (cache->flags & BTRFS_BLOCK_GROUP_DATA) {
@@ -3278,12 +3233,14 @@ btrfs_add_block_group(struct btrfs_fs_info *fs_info, u64 bytes_used, u64 type,
        BUG_ON(ret);
 
        bit = block_group_state_bits(type);
-       set_extent_bits(block_group_cache, chunk_offset,
-                       chunk_offset + size - 1,
-                       bit | EXTENT_LOCKED, GFP_NOFS);
+       ret = set_extent_bits(block_group_cache, chunk_offset,
+                             chunk_offset + size - 1,
+                             bit | EXTENT_LOCKED, GFP_NOFS);
+       BUG_ON(ret);
 
-       set_state_private(block_group_cache, chunk_offset,
-                         (unsigned long)cache);
+       ret = set_state_private(block_group_cache, chunk_offset,
+                               (unsigned long)cache);
+       BUG_ON(ret);
        set_avail_alloc_bits(fs_info, type);
 
        return cache;
@@ -3305,8 +3262,11 @@ int btrfs_make_block_group(struct btrfs_trans_handle *trans,
                                sizeof(cache->item));
        BUG_ON(ret);
 
-       finish_current_insert(trans, extent_root);
+       ret = finish_current_insert(trans, extent_root);
+       BUG_ON(ret);
        ret = del_pending_extents(trans, extent_root);
+       BUG_ON(ret);
+
        return 0;
 }
 
@@ -3422,88 +3382,6 @@ int btrfs_update_block_group(struct btrfs_trans_handle *trans,
                                  alloc, mark_free);
 }
 
-static int btrfs_count_extents_in_block_group(struct btrfs_root *root,
-                                             struct btrfs_path *path, u64 start,
-                                             u64 len,
-                                             u64 *total)
-{
-       struct btrfs_key key;
-       struct extent_buffer *leaf;
-       u64 bytes_used = 0;
-       int ret;
-       int slot;
-
-       key.offset = 0;
-       key.objectid = start;
-       btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
-       ret = btrfs_search_slot(NULL, root->fs_info->extent_root,
-                               &key, path, 0, 0);
-       if (ret < 0)
-               return ret;
-       while(1) {
-               leaf = path->nodes[0];
-               slot = path->slots[0];
-               if (slot >= btrfs_header_nritems(leaf)) {
-                       ret = btrfs_next_leaf(root, path);
-                       if (ret < 0)
-                               return ret;
-                       if (ret > 0)
-                               break;
-                       leaf = path->nodes[0];
-                       slot = path->slots[0];
-               }
-               btrfs_item_key_to_cpu(leaf, &key, slot);
-               if (key.objectid > start + len)
-                       break;
-               if (key.type == BTRFS_EXTENT_ITEM_KEY)
-                       bytes_used += key.offset;
-               if (key.type == BTRFS_METADATA_ITEM_KEY)
-                       bytes_used += root->leafsize;
-               path->slots[0]++;
-       }
-       *total = bytes_used;
-       btrfs_release_path(root, path);
-       return 0;
-}
-
-int btrfs_check_block_accounting(struct btrfs_root *root)
-{
-       int ret;
-       u64 start = 0;
-       u64 bytes_used = 0;
-       struct btrfs_path path;
-       struct btrfs_block_group_cache *cache;
-       struct btrfs_fs_info *fs_info = root->fs_info;
-
-       btrfs_init_path(&path);
-
-       while(1) {
-               cache = btrfs_lookup_block_group(fs_info, start);
-               if (!cache)
-                       break;
-
-               ret = btrfs_count_extents_in_block_group(root, &path,
-                                                        cache->key.objectid,
-                                                        cache->key.offset,
-                                                        &bytes_used);
-
-               if (ret == 0) {
-                       u64 on_disk = btrfs_block_group_used(&cache->item);
-                       if (on_disk != bytes_used) {
-                               fprintf(stderr, "bad block group accounting found %llu "
-                                       "expected %llu block group %llu\n",
-                                       (unsigned long long)bytes_used,
-                                       (unsigned long long)on_disk,
-                                       (unsigned long long)cache->key.objectid);
-                       }
-               }
-               start = cache->key.objectid + cache->key.offset;
-
-               cache->space_info->bytes_used = 0;
-       }
-       return 0;
-}
-
 /*
  * Fixup block accounting. The initial block accounting created by
  * make_block_groups isn't accuracy in this case.
@@ -3580,6 +3458,100 @@ int btrfs_fix_block_accounting(struct btrfs_trans_handle *trans,
                path.slots[0]++;
        }
        btrfs_set_super_bytes_used(root->fs_info->super_copy, bytes_used);
-       btrfs_release_path(root, &path);
+       btrfs_release_path(&path);
        return 0;
 }
+
+/*
+ * Record a file extent. Do all the required works, such as inserting
+ * file extent item, inserting extent item and backref item into extent
+ * tree and updating block accounting.
+ */
+int btrfs_record_file_extent(struct btrfs_trans_handle *trans,
+                             struct btrfs_root *root, u64 objectid,
+                             struct btrfs_inode_item *inode,
+                             u64 file_pos, u64 disk_bytenr,
+                             u64 num_bytes)
+{
+       int ret;
+       struct btrfs_fs_info *info = root->fs_info;
+       struct btrfs_root *extent_root = info->extent_root;
+       struct extent_buffer *leaf;
+       struct btrfs_file_extent_item *fi;
+       struct btrfs_key ins_key;
+       struct btrfs_path path;
+       struct btrfs_extent_item *ei;
+       u64 nbytes;
+
+       if (disk_bytenr == 0) {
+               ret = btrfs_insert_file_extent(trans, root, objectid,
+                                               file_pos, disk_bytenr,
+                                               num_bytes, num_bytes);
+               return ret;
+       }
+
+       btrfs_init_path(&path);
+
+       ins_key.objectid = objectid;
+       ins_key.offset = file_pos;
+       btrfs_set_key_type(&ins_key, BTRFS_EXTENT_DATA_KEY);
+       ret = btrfs_insert_empty_item(trans, root, &path, &ins_key,
+                                     sizeof(*fi));
+       if (ret)
+               goto fail;
+       leaf = path.nodes[0];
+       fi = btrfs_item_ptr(leaf, path.slots[0],
+                           struct btrfs_file_extent_item);
+       btrfs_set_file_extent_generation(leaf, fi, trans->transid);
+       btrfs_set_file_extent_type(leaf, fi, BTRFS_FILE_EXTENT_REG);
+       btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
+       btrfs_set_file_extent_disk_num_bytes(leaf, fi, num_bytes);
+       btrfs_set_file_extent_offset(leaf, fi, 0);
+       btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
+       btrfs_set_file_extent_ram_bytes(leaf, fi, num_bytes);
+       btrfs_set_file_extent_compression(leaf, fi, 0);
+       btrfs_set_file_extent_encryption(leaf, fi, 0);
+       btrfs_set_file_extent_other_encoding(leaf, fi, 0);
+       btrfs_mark_buffer_dirty(leaf);
+
+       nbytes = btrfs_stack_inode_nbytes(inode) + num_bytes;
+       btrfs_set_stack_inode_nbytes(inode, nbytes);
+
+       btrfs_release_path(&path);
+
+       ins_key.objectid = disk_bytenr;
+       ins_key.offset = num_bytes;
+       ins_key.type = BTRFS_EXTENT_ITEM_KEY;
+
+       ret = btrfs_insert_empty_item(trans, extent_root, &path,
+                                     &ins_key, sizeof(*ei));
+       if (ret == 0) {
+               leaf = path.nodes[0];
+               ei = btrfs_item_ptr(leaf, path.slots[0],
+                                   struct btrfs_extent_item);
+
+               btrfs_set_extent_refs(leaf, ei, 0);
+               btrfs_set_extent_generation(leaf, ei, 0);
+               btrfs_set_extent_flags(leaf, ei, BTRFS_EXTENT_FLAG_DATA);
+
+               btrfs_mark_buffer_dirty(leaf);
+
+               ret = btrfs_update_block_group(trans, root, disk_bytenr,
+                                              num_bytes, 1, 0);
+               if (ret)
+                       goto fail;
+       } else if (ret != -EEXIST) {
+               goto fail;
+       }
+       btrfs_extent_post_op(trans, extent_root);
+
+       ret = btrfs_inc_extent_ref(trans, root, disk_bytenr, num_bytes, 0,
+                                  root->root_key.objectid,
+                                  objectid, file_pos);
+       if (ret)
+               goto fail;
+       ret = 0;
+fail:
+       btrfs_release_path(&path);
+       return ret;
+}