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-rw-r--r--fs/btrfs/ctree.h3
-rw-r--r--fs/btrfs/extent-tree.c37
-rw-r--r--fs/btrfs/volumes.c3
3 files changed, 38 insertions, 5 deletions
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 1573be6f9518..d88994f71eae 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -3480,7 +3480,8 @@ int btrfs_make_block_group(struct btrfs_trans_handle *trans,
u64 type, u64 chunk_objectid, u64 chunk_offset,
u64 size);
struct btrfs_trans_handle *btrfs_start_trans_remove_block_group(
- struct btrfs_fs_info *fs_info);
+ struct btrfs_fs_info *fs_info,
+ const u64 chunk_offset);
int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 group_start,
struct extent_map *em);
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 78200932c1cf..e97d6d61cd42 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -10257,14 +10257,44 @@ out:
}
struct btrfs_trans_handle *
-btrfs_start_trans_remove_block_group(struct btrfs_fs_info *fs_info)
+btrfs_start_trans_remove_block_group(struct btrfs_fs_info *fs_info,
+ const u64 chunk_offset)
{
+ struct extent_map_tree *em_tree = &fs_info->mapping_tree.map_tree;
+ struct extent_map *em;
+ struct map_lookup *map;
+ unsigned int num_items;
+
+ read_lock(&em_tree->lock);
+ em = lookup_extent_mapping(em_tree, chunk_offset, 1);
+ read_unlock(&em_tree->lock);
+ ASSERT(em && em->start == chunk_offset);
+
/*
+ * We need to reserve 3 + N units from the metadata space info in order
+ * to remove a block group (done at btrfs_remove_chunk() and at
+ * btrfs_remove_block_group()), which are used for:
+ *
* 1 unit for adding the free space inode's orphan (located in the tree
* of tree roots).
+ * 1 unit for deleting the block group item (located in the extent
+ * tree).
+ * 1 unit for deleting the free space item (located in tree of tree
+ * roots).
+ * N units for deleting N device extent items corresponding to each
+ * stripe (located in the device tree).
+ *
+ * In order to remove a block group we also need to reserve units in the
+ * system space info in order to update the chunk tree (update one or
+ * more device items and remove one chunk item), but this is done at
+ * btrfs_remove_chunk() through a call to check_system_chunk().
*/
+ map = (struct map_lookup *)em->bdev;
+ num_items = 3 + map->num_stripes;
+ free_extent_map(em);
+
return btrfs_start_transaction_fallback_global_rsv(fs_info->extent_root,
- 1, 1);
+ num_items, 1);
}
/*
@@ -10333,7 +10363,8 @@ void btrfs_delete_unused_bgs(struct btrfs_fs_info *fs_info)
* Want to do this before we do anything else so we can recover
* properly if we fail to join the transaction.
*/
- trans = btrfs_start_trans_remove_block_group(fs_info);
+ trans = btrfs_start_trans_remove_block_group(fs_info,
+ block_group->key.objectid);
if (IS_ERR(trans)) {
btrfs_dec_block_group_ro(root, block_group);
ret = PTR_ERR(trans);
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index e0bd364e958d..45f20252efed 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2853,7 +2853,8 @@ static int btrfs_relocate_chunk(struct btrfs_root *root, u64 chunk_offset)
if (ret)
return ret;
- trans = btrfs_start_trans_remove_block_group(root->fs_info);
+ trans = btrfs_start_trans_remove_block_group(root->fs_info,
+ chunk_offset);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
btrfs_std_error(root->fs_info, ret, NULL);