Re: [PATCH v8 10/20] xfs: Add helper function __xfs_attr_rmtval_remove

[Brian Foster <bfoster@redhat.com>]

On Fri, Apr 03, 2020 at 03:12:19PM -0700, Allison Collins wrote:
> This function is similar to xfs_attr_rmtval_remove, but adapted to
> return EAGAIN for new transactions. We will use this later when we
> introduce delayed attributes.  This function will eventually replace
> xfs_attr_rmtval_remove
> 
> Signed-off-by: Allison Collins <allison.henderson@oracle.com>
> Reviewed-by: Chandan Rajendra <chandanrlinux@gmail.com>
> ---
>  fs/xfs/libxfs/xfs_attr_remote.c | 25 +++++++++++++++++++++++++
>  fs/xfs/libxfs/xfs_attr_remote.h |  1 +
>  2 files changed, 26 insertions(+)
> 
> diff --git a/fs/xfs/libxfs/xfs_attr_remote.c b/fs/xfs/libxfs/xfs_attr_remote.c
> index 4d51969..fd4be9d 100644
> --- a/fs/xfs/libxfs/xfs_attr_remote.c
> +++ b/fs/xfs/libxfs/xfs_attr_remote.c
> @@ -711,3 +711,28 @@ xfs_attr_rmtval_remove(
>  	}
>  	return 0;
>  }
> +
> +/*
> + * Remove the value associated with an attribute by deleting the out-of-line
> + * buffer that it is stored on. Returns EAGAIN for the caller to refresh the
> + * transaction and recall the function
> + */
> +int
> +__xfs_attr_rmtval_remove(
> +	struct xfs_da_args	*args)
> +{
> +	int	error, done;
> +
> +	/*
> +	 * Unmap value blocks for this attr.
> +	 */
> +	error = xfs_bunmapi(args->trans, args->dp, args->rmtblkno,
> +			    args->rmtblkcnt, XFS_BMAPI_ATTRFORK, 1, &done);
> +	if (error)
> +		return error;
> +
> +	if (!done)
> +		return -EAGAIN;
> +
> +	return 0;
> +}

We should let xfs_attr_rmtval_remove() call this function and do the
roll based on -EAGAIN, then eliminate the higher level function later if
it becomes unused.

Brian

> diff --git a/fs/xfs/libxfs/xfs_attr_remote.h b/fs/xfs/libxfs/xfs_attr_remote.h
> index eff5f95..ee3337b 100644
> --- a/fs/xfs/libxfs/xfs_attr_remote.h
> +++ b/fs/xfs/libxfs/xfs_attr_remote.h
> @@ -14,4 +14,5 @@ int xfs_attr_rmtval_remove(struct xfs_da_args *args);
>  int xfs_attr_rmtval_stale(struct xfs_inode *ip, struct xfs_bmbt_irec *map,
>  		xfs_buf_flags_t incore_flags);
>  int xfs_attr_rmtval_invalidate(struct xfs_da_args *args);
> +int __xfs_attr_rmtval_remove(struct xfs_da_args *args);
>  #endif /* __XFS_ATTR_REMOTE_H__ */
> -- 
> 2.7.4
>