summaryrefslogtreecommitdiff
path: root/fs/btrfs/extent-tree.c
diff options
context:
space:
mode:
Diffstat (limited to 'fs/btrfs/extent-tree.c')
-rw-r--r--fs/btrfs/extent-tree.c16
1 files changed, 16 insertions, 0 deletions
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 38b76cc02f48..171312d51799 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -2296,9 +2296,22 @@ static int run_one_delayed_ref(struct btrfs_trans_handle *trans,
static inline struct btrfs_delayed_ref_node *
select_delayed_ref(struct btrfs_delayed_ref_head *head)
{
+ struct btrfs_delayed_ref_node *ref;
+
if (list_empty(&head->ref_list))
return NULL;
+ /*
+ * Select a delayed ref of type BTRFS_ADD_DELAYED_REF first.
+ * This is to prevent a ref count from going down to zero, which deletes
+ * the extent item from the extent tree, when there still are references
+ * to add, which would fail because they would not find the extent item.
+ */
+ list_for_each_entry(ref, &head->ref_list, list) {
+ if (ref->action == BTRFS_ADD_DELAYED_REF)
+ return ref;
+ }
+
return list_entry(head->ref_list.next, struct btrfs_delayed_ref_node,
list);
}
@@ -9889,6 +9902,8 @@ void btrfs_delete_unused_bgs(struct btrfs_fs_info *fs_info)
}
spin_unlock(&fs_info->unused_bgs_lock);
+ mutex_lock(&root->fs_info->delete_unused_bgs_mutex);
+
/* Don't want to race with allocators so take the groups_sem */
down_write(&space_info->groups_sem);
spin_lock(&block_group->lock);
@@ -9983,6 +9998,7 @@ void btrfs_delete_unused_bgs(struct btrfs_fs_info *fs_info)
end_trans:
btrfs_end_transaction(trans, root);
next:
+ mutex_unlock(&root->fs_info->delete_unused_bgs_mutex);
btrfs_put_block_group(block_group);
spin_lock(&fs_info->unused_bgs_lock);
}