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

[Allison Henderson <allison.henderson@xxxxxxxxxx>]

On 2/25/21 9:29 PM, Darrick J. Wong wrote:
> 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@xxxxxxxxxx>
> > ---
> >   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
Sure, I can wrap it with the CONFIG_XFS_DEBUG for now.  I think 
eventually the plan is to get rid of the option all together.

Allison
> >   	{}
> >   };
> >   
> > @@ -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