Btrfs: add START_SYNC, WAIT_SYNC ioctls

[net-next-2.6.git] / fs / btrfs / transaction.c

diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 9f40bfc9c45c3e0056b168db527de212114d0179..1fffbc017bdfe0451cc2e67ccf5fd85623a12aee 100644 (file)
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -279,6 +279,58 @@ static noinline int wait_for_commit(struct btrfs_root *root,
        return 0;
 }
 
+int btrfs_wait_for_commit(struct btrfs_root *root, u64 transid)
+{
+       struct btrfs_transaction *cur_trans = NULL, *t;
+       int ret;
+
+       mutex_lock(&root->fs_info->trans_mutex);
+
+       ret = 0;
+       if (transid) {
+               if (transid <= root->fs_info->last_trans_committed)
+                       goto out_unlock;
+
+               /* find specified transaction */
+               list_for_each_entry(t, &root->fs_info->trans_list, list) {
+                       if (t->transid == transid) {
+                               cur_trans = t;
+                               break;
+                       }
+                       if (t->transid > transid)
+                               break;
+               }
+               ret = -EINVAL;
+               if (!cur_trans)
+                       goto out_unlock;  /* bad transid */
+       } else {
+               /* find newest transaction that is committing | committed */
+               list_for_each_entry_reverse(t, &root->fs_info->trans_list,
+                                           list) {
+                       if (t->in_commit) {
+                               if (t->commit_done)
+                                       goto out_unlock;
+                               cur_trans = t;
+                               break;
+                       }
+               }
+               if (!cur_trans)
+                       goto out_unlock;  /* nothing committing|committed */
+       }
+
+       cur_trans->use_count++;
+       mutex_unlock(&root->fs_info->trans_mutex);
+
+       wait_for_commit(root, cur_trans);
+
+       mutex_lock(&root->fs_info->trans_mutex);
+       put_transaction(cur_trans);
+       ret = 0;
+out_unlock:
+       mutex_unlock(&root->fs_info->trans_mutex);
+       return ret;
+}
+
 #if 0
 /*
  * rate limit against the drop_snapshot code.  This helps to slow down new