Re: [PATCH v15 21/22] xfs: Add delattr mount option

From: "Darrick J. Wong" <djwong@kernel.org>
To: Allison Henderson <allison.henderson@oracle.com>
Cc: linux-xfs@vger.kernel.org
Subject: Re: [PATCH v15 21/22] xfs: Add delattr mount option
Date: Thu, 25 Feb 2021 20:29:46 -0800	[thread overview]
Message-ID: <20210226042946.GW7272@magnolia> (raw)
In-Reply-To: <20210218165348.4754-22-allison.henderson@oracle.com>

On Thu, Feb 18, 2021 at 09:53:47AM -0700, Allison Henderson wrote:
> This patch adds a mount option to enable delayed attributes. Eventually
> this can be removed when delayed attrs becomes permanent.
> 
> Signed-off-by: Allison Henderson <allison.henderson@oracle.com>
> ---
>  fs/xfs/libxfs/xfs_attr.h | 2 +-
>  fs/xfs/xfs_mount.h       | 1 +
>  fs/xfs/xfs_super.c       | 6 +++++-
>  fs/xfs/xfs_xattr.c       | 2 ++
>  4 files changed, 9 insertions(+), 2 deletions(-)
> 
> diff --git a/fs/xfs/libxfs/xfs_attr.h b/fs/xfs/libxfs/xfs_attr.h
> index f82c0b1..35f3a53 100644
> --- a/fs/xfs/libxfs/xfs_attr.h
> +++ b/fs/xfs/libxfs/xfs_attr.h
> @@ -30,7 +30,7 @@ struct xfs_attr_list_context;
>  
>  static inline bool xfs_hasdelattr(struct xfs_mount *mp)
>  {
> -	return false;
> +	return mp->m_flags & XFS_MOUNT_DELATTR;
>  }
>  
>  /*
> diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
> index 659ad95..57cd914 100644
> --- a/fs/xfs/xfs_mount.h
> +++ b/fs/xfs/xfs_mount.h
> @@ -250,6 +250,7 @@ typedef struct xfs_mount {
>  #define XFS_MOUNT_NOATTR2	(1ULL << 25)	/* disable use of attr2 format */
>  #define XFS_MOUNT_DAX_ALWAYS	(1ULL << 26)
>  #define XFS_MOUNT_DAX_NEVER	(1ULL << 27)
> +#define XFS_MOUNT_DELATTR	(1ULL << 28)	/* enable delayed attributes */
>  
>  /*
>   * Max and min values for mount-option defined I/O
> diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
> index 21b1d03..f6b08f9 100644
> --- a/fs/xfs/xfs_super.c
> +++ b/fs/xfs/xfs_super.c
> @@ -93,7 +93,7 @@ enum {
>  	Opt_filestreams, Opt_quota, Opt_noquota, Opt_usrquota, Opt_grpquota,
>  	Opt_prjquota, Opt_uquota, Opt_gquota, Opt_pquota,
>  	Opt_uqnoenforce, Opt_gqnoenforce, Opt_pqnoenforce, Opt_qnoenforce,
> -	Opt_discard, Opt_nodiscard, Opt_dax, Opt_dax_enum,
> +	Opt_discard, Opt_nodiscard, Opt_dax, Opt_dax_enum, Opt_delattr
>  };
>  
>  static const struct fs_parameter_spec xfs_fs_parameters[] = {
> @@ -138,6 +138,7 @@ static const struct fs_parameter_spec xfs_fs_parameters[] = {
>  	fsparam_flag("nodiscard",	Opt_nodiscard),
>  	fsparam_flag("dax",		Opt_dax),
>  	fsparam_enum("dax",		Opt_dax_enum, dax_param_enums),
> +	fsparam_flag("delattr",		Opt_delattr),

I wonder if this ought to be hidden behind CONFIG_XFS_DEBUG=y, but
other than that this looks fine to me.

--D

>  	{}
>  };
>  
> @@ -1263,6 +1264,9 @@ xfs_fs_parse_param(
>  		xfs_mount_set_dax_mode(mp, result.uint_32);
>  		return 0;
>  #endif
> +	case Opt_delattr:
> +		mp->m_flags |= XFS_MOUNT_DELATTR;
> +		return 0;
>  	/* Following mount options will be removed in September 2025 */
>  	case Opt_ikeep:
>  		xfs_warn(mp, "%s mount option is deprecated.", param->key);
> diff --git a/fs/xfs/xfs_xattr.c b/fs/xfs/xfs_xattr.c
> index 9b0c790..8ec61df 100644
> --- a/fs/xfs/xfs_xattr.c
> +++ b/fs/xfs/xfs_xattr.c
> @@ -8,6 +8,8 @@
>  #include "xfs_shared.h"
>  #include "xfs_format.h"
>  #include "xfs_log_format.h"
> +#include "xfs_trans_resv.h"
> +#include "xfs_mount.h"
>  #include "xfs_da_format.h"
>  #include "xfs_inode.h"
>  #include "xfs_da_btree.h"
> -- 
> 2.7.4
> 