Re: [PATCH v2 5/6] xfs: initialise args->total for parent pointer updates

["Darrick J. Wong" <djwong@kernel.org>]

On Mon, Aug 10, 2026 at 10:43:18AM -0600, Javier Tia wrote:
> xfs_parent_da_args_init() builds an xfs_da_args from a zeroed
> xfs_parent_args (kmem_cache_zalloc), leaving args->total == 0.
> xfs_da_grow_inode_int() treats that field as a running block reservation
> and subtracts from it; because it is an xfs_extlen_t (uint32_t), the
> first attr-fork growth wraps it to ~0U.  That defeats the free-space
> check in xfs_alloc_space_available(), and when it coincides with an AG
> that has exactly zero available blocks the allocation is clamped to
> maxlen 0 and returns -ENOSPC, which xfs_defer_finish_noroll() escalates
> to a filesystem shutdown.
> 
> Set args->total the way the log recovery path does
> (xfs_attri_recover_work(), xfs_attr_item.c:706), in the add and replace
> paths that can grow the fork.  Removals and lookups never grow it, so
> they leave the field alone, matching that switch.
> 
> Fixes: b7c62d90c12c ("xfs: parent pointer attribute creation")
> Cc: <stable@vger.kernel.org> # v6.10
> Signed-off-by: Javier Tia <floss@jetm.me>

Much improved, thanks for the corrections.
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>

(As a future note: please send new revisions of patchsets as a new
thread, not a continuation of the previous revision.)

--D

> ---
>  fs/xfs/libxfs/xfs_parent.c | 12 ++++++++++--
>  1 file changed, 10 insertions(+), 2 deletions(-)
> 
> diff --git a/fs/xfs/libxfs/xfs_parent.c b/fs/xfs/libxfs/xfs_parent.c
> index 3509cc4b2175..312f33086d53 100644
> --- a/fs/xfs/libxfs/xfs_parent.c
> +++ b/fs/xfs/libxfs/xfs_parent.c
> @@ -194,7 +194,7 @@ xfs_parent_addname(
>  	const struct xfs_name	*parent_name,
>  	struct xfs_inode	*child)
>  {
> -	int			error;
> +	int			error, local;
>  
>  	error = xfs_parent_iread_extents(tp, child);
>  	if (error)
> @@ -204,6 +204,10 @@ xfs_parent_addname(
>  	xfs_parent_da_args_init(&ppargs->args, tp, &ppargs->rec, child,
>  			child->i_ino, parent_name);
>  
> +	/* Growing the attr fork needs a real reservation in args->total. */
> +	ppargs->args.total = xfs_attr_calc_size(&ppargs->args, &local);
> +	ASSERT(local);
> +
>  	return xfs_attr_setname(&ppargs->args, 0);
>  }
>  
> @@ -240,7 +244,7 @@ xfs_parent_replacename(
>  	const struct xfs_name	*new_name,
>  	struct xfs_inode	*child)
>  {
> -	int			error;
> +	int			error, local;
>  
>  	error = xfs_parent_iread_extents(tp, child);
>  	if (error)
> @@ -250,6 +254,10 @@ xfs_parent_replacename(
>  	xfs_parent_da_args_init(&ppargs->args, tp, &ppargs->rec, child,
>  			child->i_ino, old_name);
>  
> +	/* Growing the attr fork needs a real reservation in args->total. */
> +	ppargs->args.total = xfs_attr_calc_size(&ppargs->args, &local);
> +	ASSERT(local);
> +
>  	xfs_inode_to_parent_rec(&ppargs->new_rec, new_dp);
>  
>  	ppargs->args.new_name = new_name->name;
> -- 
> Javier Tia
> 
>