On 13.03.20 г. 23:12 ч., Josef Bacik wrote:
> 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.
Oh I see, the changelog for this and the previous patch got switched, no ?
>
> Signed-off-by: Josef Bacik <josef@xxxxxxxxxxxxxx>
> ---
> 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 c3b3b524b8c3..8d34d7e0adb6 100644
> --- a/fs/btrfs/transaction.c
> +++ b/fs/btrfs/transaction.c
> @@ -1184,10 +1184,6 @@ 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;
>
> @@ -1205,10 +1201,6 @@ 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;
> @@ -1223,15 +1215,24 @@ 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;
>
