Re: [PATCH 16/36] btrfs: run delayed iputs before committing

[Omar Sandoval <osandov@osandov.com>]

On Tue, Sep 11, 2018 at 01:57:47PM -0400, Josef Bacik wrote:
> Delayed iputs means we can have final iputs of deleted inodes in the
> queue, which could potentially generate a lot of pinned space that could
> be free'd.  So before we decide to commit the transaction for ENOPSC
> reasons, run the delayed iputs so that any potential space is free'd up.
> If there is and we freed enough we can then commit the transaction and
> potentially be able to make our reservation.

Reviewed-by: Omar Sandoval <osandov@fb.com>

> Signed-off-by: Josef Bacik <josef@toxicpanda.com>
> ---
>  fs/btrfs/extent-tree.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
> index 76941fc5af79..57567d013447 100644
> --- a/fs/btrfs/extent-tree.c
> +++ b/fs/btrfs/extent-tree.c
> @@ -4823,6 +4823,15 @@ static int may_commit_transaction(struct btrfs_fs_info *fs_info,
>  	if (!bytes)
>  		return 0;
>  
> +	/*
> +	 * If we have pending delayed iputs then we could free up a bunch of
> +	 * pinned space, so make sure we run the iputs before we do our pinned
> +	 * bytes check below.
> +	 */
> +	mutex_lock(&fs_info->cleaner_delayed_iput_mutex);
> +	btrfs_run_delayed_iputs(fs_info);
> +	mutex_unlock(&fs_info->cleaner_delayed_iput_mutex);
> +
>  	trans = btrfs_join_transaction(fs_info->extent_root);
>  	if (IS_ERR(trans))
>  		return -ENOSPC;
> -- 
> 2.14.3
>