This was added a very long time ago to work around issues with delayed refs and with qgroups. Both of these issues have since been properly fixed, so all this does is cause a lot of lock contention with anybody else who is running delayed refs.
Signed-off-by: Josef Bacik <[email protected]> --- fs/btrfs/transaction.c | 23 ++++++++++++----------- 1 file changed, 12 insertions(+), 11 deletions(-) diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index 51c5c2f6e064..70cbc15fc58a 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -1228,10 +1228,6 @@ static noinline int commit_cowonly_roots(struct btrfs_trans_handle *trans) btrfs_tree_unlock(eb); free_extent_buffer(eb); - if (ret) - return ret; - - ret = btrfs_run_delayed_refs(trans, (unsigned long)-1); if (ret) return ret; @@ -1249,10 +1245,6 @@ static noinline int commit_cowonly_roots(struct btrfs_trans_handle *trans) if (ret) return ret; - /* run_qgroups might have added some more refs */ - ret = btrfs_run_delayed_refs(trans, (unsigned long)-1); - if (ret) - return ret; again: while (!list_empty(&fs_info->dirty_cowonly_roots)) { struct btrfs_root *root; @@ -1267,15 +1259,24 @@ static noinline int commit_cowonly_roots(struct btrfs_trans_handle *trans) ret = update_cowonly_root(trans, root); if (ret) return ret; - ret = btrfs_run_delayed_refs(trans, (unsigned long)-1); - if (ret) - return ret; } + /* Now flush any delayed refs generated by updating all of the roots. */ + ret = btrfs_run_delayed_refs(trans, (unsigned long)-1); + if (ret) + return ret; + while (!list_empty(dirty_bgs) || !list_empty(io_bgs)) { ret = btrfs_write_dirty_block_groups(trans); if (ret) return ret; + + /* + * We're writing the dirty block groups, which could generate + * delayed refs, which could generate more dirty block groups, + * so we want to keep this flushing in this loop to make sure + * everything gets run. + */ ret = btrfs_run_delayed_refs(trans, (unsigned long)-1); if (ret) return ret; -- 2.26.2
