Re: [PATCH 17/21] xfs: remove parent pointers in unlink

["Darrick J. Wong" <darrick.wong@oracle.com>]

On Sun, May 06, 2018 at 10:24:50AM -0700, Allison Henderson wrote:
> From: Dave Chinner <dchinner@redhat.com>
> 
> This patch removes the parent pointer attribute during unlink
> 
> [bfoster: rebase, use VFS inode generation]
> [achender: rebased, changed __unint32_t to xfs_dir2_dataptr_t
> 	   implemented xfs_attr_remove_parent]
> 
> Signed-off-by: Dave Chinner <dchinner@redhat.com>
> Signed-off-by: Allison Henderson <allison.henderson@oracle.com>
> ---
>  fs/xfs/xfs_inode.c        | 21 ++++++++++++++++-----
>  fs/xfs/xfs_parent_utils.c | 19 +++++++++++++++++++
>  fs/xfs/xfs_parent_utils.h |  4 ++++
>  3 files changed, 39 insertions(+), 5 deletions(-)
> 
> diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
> index 3a68e72..b18b20c 100644
> --- a/fs/xfs/xfs_inode.c
> +++ b/fs/xfs/xfs_inode.c
> @@ -2624,6 +2624,7 @@ xfs_remove(
>  	struct xfs_defer_ops	dfops;
>  	xfs_fsblock_t           first_block;
>  	uint			resblks;
> +	xfs_dir2_dataptr_t	dir_offset;
>  
>  	trace_xfs_remove(dp, name);
>  
> @@ -2661,8 +2662,8 @@ xfs_remove(
>  
>  	xfs_lock_two_inodes(dp, XFS_ILOCK_EXCL, ip, XFS_ILOCK_EXCL);
>  
> -	xfs_trans_ijoin(tp, dp, XFS_ILOCK_EXCL);
> -	xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
> +	xfs_trans_ijoin(tp, dp, 0);
> +	xfs_trans_ijoin(tp, ip, 0);
>  
>  	/*
>  	 * If we're removing a directory perform some additional validation.
> @@ -2704,12 +2705,18 @@ xfs_remove(
>  
>  	xfs_defer_init(&dfops, &first_block);
>  	error = xfs_dir_removename(tp, dp, name, ip->i_ino, &first_block,
> -				   &dfops, resblks, NULL);
> +				   &dfops, resblks, &dir_offset);
>  	if (error) {
>  		ASSERT(error != -ENOENT);
>  		goto out_bmap_cancel;
>  	}
>  
> +	if (xfs_sb_version_hasparent(&mp->m_sb)) {
> +		error = xfs_parent_remove_deferred(dp, ip, dir_offset, &dfops);
> +		if (error)
> +			goto out_bmap_cancel;
> +	}
> +
>  	/*
>  	 * If this is a synchronous mount, make sure that the
>  	 * remove transaction goes to disk before returning to
> @@ -2724,17 +2731,21 @@ xfs_remove(
>  
>  	error = xfs_trans_commit(tp);
>  	if (error)
> -		goto std_return;
> +		goto out_unlock;
>  
>  	if (is_dir && xfs_inode_is_filestream(ip))
>  		xfs_filestream_deassociate(ip);
>  
> -	return 0;
> +	error = 0;
> +	goto out_unlock;

I'd unlock the two inodes directly here instead of mixing the sucess
return path with the error paths.

>  
>   out_bmap_cancel:
>  	xfs_defer_cancel(&dfops);
>   out_trans_cancel:
>  	xfs_trans_cancel(tp);
> +out_unlock:
> +	xfs_iunlock(ip, XFS_ILOCK_EXCL);
> +	xfs_iunlock(dp, XFS_ILOCK_EXCL);
>   std_return:
>  	return error;
>  }
> diff --git a/fs/xfs/xfs_parent_utils.c b/fs/xfs/xfs_parent_utils.c
> index cf4a7e2..0fd48b8 100644
> --- a/fs/xfs/xfs_parent_utils.c
> +++ b/fs/xfs/xfs_parent_utils.c
> @@ -49,3 +49,22 @@ xfs_parent_add_deferred(
>  		(void *)child_name->name, child_name->len, ATTR_PARENT);
>  }
>  
> +/*
> + * Remove a parent record from a child inode.
> + */
> +int
> +xfs_parent_remove_deferred(
> +	struct xfs_inode	*parent,
> +	struct xfs_inode	*child,
> +	xfs_dir2_dataptr_t	diroffset,
> +	struct xfs_defer_ops	*dfops)
> +{
> +	struct xfs_parent_name_rec rec;
> +
> +	xfs_init_parent_name_rec(&rec, parent->i_ino,
> +				 VFS_I(parent)->i_generation, diroffset);
> +
> +	return xfs_attr_remove_deferred(child, dfops, &rec, sizeof(rec),
> +					ATTR_PARENT);

Two indents, no need to align these with the left paren.

--D

> +}
> +
> diff --git a/fs/xfs/xfs_parent_utils.h b/fs/xfs/xfs_parent_utils.h
> index a667d1d..9e0ac13 100644
> --- a/fs/xfs/xfs_parent_utils.h
> +++ b/fs/xfs/xfs_parent_utils.h
> @@ -23,4 +23,8 @@
>  int xfs_parent_add_deferred(struct xfs_inode *parent, struct xfs_inode *child,
>  	       struct xfs_name *child_name, uint32_t diroffset,
>  	       struct xfs_defer_ops *dfops);
> +int xfs_parent_remove_deferred(struct xfs_inode *parent,
> +			       struct xfs_inode *child,
> +			       xfs_dir2_dataptr_t diroffset,
> +			       struct xfs_defer_ops *dfops);
>  #endif	/* __XFS_PARENT_UTILS_H__ */
> -- 
> 2.7.4
> 
> --
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