Re: [PATCH 08/18] xfsprogs: Implement attr logging and replay

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

On Wed, May 18, 2022 at 09:38:09AM -0700, Alli wrote:
> On Tue, 2022-05-17 at 17:31 -0700, Darrick J. Wong wrote:
> > On Tue, May 17, 2022 at 05:12:17PM -0700, Allison Henderson wrote:
> > > Source kernel commit: 1d08e11d04d293cb7006d1c8641be1fdd8a8e397
> > > 
> > > This patch adds the needed routines to create, log and recover
> > > logged
> > > extended attribute intents.
> > > 
> > > Signed-off-by: Allison Henderson <allison.henderson@oracle.com>
> > > Reviewed-by: Chandan Babu R <chandanrlinux@gmail.com>
> > > Reviewed-by: Darrick J. Wong <djwong@kernel.org>
> > > Signed-off-by: Dave Chinner <david@fromorbit.com>
> > > Signed-off-by: Allison Henderson <allison.henderson@oracle.com>
> > > ---
> > >  libxfs/defer_item.c | 119
> > > ++++++++++++++++++++++++++++++++++++++++++++
> > >  libxfs/xfs_defer.c  |   1 +
> > >  libxfs/xfs_defer.h  |   1 +
> > >  libxfs/xfs_format.h |   9 +++-
> > >  4 files changed, 129 insertions(+), 1 deletion(-)
> > > 
> > > diff --git a/libxfs/defer_item.c b/libxfs/defer_item.c
> > > index 1337fa5fa457..d2d12b50cce4 100644
> > > --- a/libxfs/defer_item.c
> > > +++ b/libxfs/defer_item.c
> > > @@ -120,6 +120,125 @@ const struct xfs_defer_op_type
> > > xfs_extent_free_defer_type = {
> > >  	.cancel_item	= xfs_extent_free_cancel_item,
> > >  };
> > >  
> > > +/*
> > > + * Performs one step of an attribute update intent and marks the
> > > attrd item
> > > + * dirty..  An attr operation may be a set or a remove.  Note that
> > > the
> > > + * transaction is marked dirty regardless of whether the operation
> > > succeeds or
> > > + * fails to support the ATTRI/ATTRD lifecycle rules.
> > > + */
> > > +STATIC int
> > > +xfs_trans_attr_finish_update(
> > 
> > This ought to have a name indicating that it's an xattr operation,
> > since
> > defer_item.c contains stubs for what in the kernel are real logged
> > operations.
> Sure, maybe just xfs_trans_xattr_finish_update?   Or
> xfs_xattr_finish_update?

That could work.  Or...

> > 
> > --D
> > 
> > > +	struct xfs_delattr_context	*dac,
> > > +	struct xfs_buf			**leaf_bp,
> > > +	uint32_t			op_flags)
> > > +{
> > > +	struct xfs_da_args		*args = dac->da_args;
> > > +	unsigned int			op = op_flags &
> > > +					     XFS_ATTR_OP_FLAGS_TYPE_MAS
> > > K;
> > > +	int				error;
> > > +
> > > +	switch (op) {
> > > +	case XFS_ATTR_OP_FLAGS_SET:
> > > +		error = xfs_attr_set_iter(dac, leaf_bp);
> > > +		break;
> > > +	case XFS_ATTR_OP_FLAGS_REMOVE:
> > > +		ASSERT(XFS_IFORK_Q(args->dp));
> > > +		error = xfs_attr_remove_iter(dac);
> > > +		break;
> > > +	default:
> > > +		error = -EFSCORRUPTED;
> > > +		break;
> > > +	}

...since xfsprogs doesn't have the overhead of actually doing log item
operations, you could just put this chunk into the _finish_item function
directly.

> > > +
> > > +	/*
> > > +	 * Mark the transaction dirty, even on error. This ensures the
> > > +	 * transaction is aborted, which:
> > > +	 *
> > > +	 * 1.) releases the ATTRI and frees the ATTRD
> > > +	 * 2.) shuts down the filesystem
> > > +	 */
> > > +	args->trans->t_flags |= XFS_TRANS_DIRTY |
> > > XFS_TRANS_HAS_INTENT_DONE;

Also, I don't think it's necessary to mark the transaction dirty, since
the buffers logged by xfs_attr_*_iter will do that for you.

I'm not sure about whether or not userspace needs to set _INTENT_DONE; I
haven't seen the userspace port of those patches.

--D

> > > +
> > > +	return error;
> > > +}
> > > +
> > > +/* Get an ATTRI. */
> > > +static struct xfs_log_item *
> > > +xfs_attr_create_intent(
> > > +	struct xfs_trans		*tp,
> > > +	struct list_head		*items,
> > > +	unsigned int			count,
> > > +	bool				sort)
> > > +{
> > > +	return NULL;
> > > +}
> > > +
> > > +/* Abort all pending ATTRs. */
> > > +STATIC void
> > > +xfs_attr_abort_intent(
> > > +	struct xfs_log_item		*intent)
> > > +{
> > > +}
> > > +
> > > +/* Get an ATTRD so we can process all the attrs. */
> > > +static struct xfs_log_item *
> > > +xfs_attr_create_done(
> > > +	struct xfs_trans		*tp,
> > > +	struct xfs_log_item		*intent,
> > > +	unsigned int			count)
> > > +{
> > > +	return NULL;
> > > +}
> > > +
> > > +/* Process an attr. */
> > > +STATIC int
> > > +xfs_attr_finish_item(
> > > +	struct xfs_trans		*tp,
> > > +	struct xfs_log_item		*done,
> > > +	struct list_head		*item,
> > > +	struct xfs_btree_cur		**state)
> > > +{
> > > +	struct xfs_attr_item		*attr;
> > > +	int				error;
> > > +	struct xfs_delattr_context	*dac;
> > > +
> > > +	attr = container_of(item, struct xfs_attr_item, xattri_list);
> > > +	dac = &attr->xattri_dac;
> > > +
> > > +	/*
> > > +	 * Always reset trans after EAGAIN cycle
> > > +	 * since the transaction is new
> > > +	 */
> > > +	dac->da_args->trans = tp;
> > > +
> > > +	error = xfs_trans_attr_finish_update(dac, &dac->leaf_bp,
> > > +					     attr->xattri_op_flags);
> > > +	if (error != -EAGAIN)
> > > +		kmem_free(attr);
> > > +
> > > +	return error;
> > > +}
> > > +
> > > +/* Cancel an attr */
> > > +STATIC void
> > > +xfs_attr_cancel_item(
> > > +	struct list_head		*item)
> > > +{
> > > +	struct xfs_attr_item		*attr;
> > > +
> > > +	attr = container_of(item, struct xfs_attr_item, xattri_list);
> > > +	kmem_free(attr);
> > > +}
> > > +
> > > +const struct xfs_defer_op_type xfs_attr_defer_type = {
> > > +	.max_items	= 1,
> > > +	.create_intent	= xfs_attr_create_intent,
> > > +	.abort_intent	= xfs_attr_abort_intent,
> > > +	.create_done	= xfs_attr_create_done,
> > > +	.finish_item	= xfs_attr_finish_item,
> > > +	.cancel_item	= xfs_attr_cancel_item,
> > > +};
> > > +
> > >  /*
> > >   * AGFL blocks are accounted differently in the reserve pools and
> > > are not
> > >   * inserted into the busy extent list.
> > > diff --git a/libxfs/xfs_defer.c b/libxfs/xfs_defer.c
> > > index 3a2576c14ee9..259ae39f90b5 100644
> > > --- a/libxfs/xfs_defer.c
> > > +++ b/libxfs/xfs_defer.c
> > > @@ -180,6 +180,7 @@ static const struct xfs_defer_op_type
> > > *defer_op_types[] = {
> > >  	[XFS_DEFER_OPS_TYPE_RMAP]	= &xfs_rmap_update_defer_type,
> > >  	[XFS_DEFER_OPS_TYPE_FREE]	= &xfs_extent_free_defer_type,
> > >  	[XFS_DEFER_OPS_TYPE_AGFL_FREE]	=
> > > &xfs_agfl_free_defer_type,
> > > +	[XFS_DEFER_OPS_TYPE_ATTR]	= &xfs_attr_defer_type,
> > >  };
> > >  
> > >  static bool
> > > diff --git a/libxfs/xfs_defer.h b/libxfs/xfs_defer.h
> > > index c3a540345fae..f18494c0d791 100644
> > > --- a/libxfs/xfs_defer.h
> > > +++ b/libxfs/xfs_defer.h
> > > @@ -19,6 +19,7 @@ enum xfs_defer_ops_type {
> > >  	XFS_DEFER_OPS_TYPE_RMAP,
> > >  	XFS_DEFER_OPS_TYPE_FREE,
> > >  	XFS_DEFER_OPS_TYPE_AGFL_FREE,
> > > +	XFS_DEFER_OPS_TYPE_ATTR,
> > >  	XFS_DEFER_OPS_TYPE_MAX,
> > >  };
> > >  
> > > diff --git a/libxfs/xfs_format.h b/libxfs/xfs_format.h
> > > index d665c04e69dd..302b50bc5830 100644
> > > --- a/libxfs/xfs_format.h
> > > +++ b/libxfs/xfs_format.h
> > > @@ -388,7 +388,9 @@ xfs_sb_has_incompat_feature(
> > >  	return (sbp->sb_features_incompat & feature) != 0;
> > >  }
> > >  
> > > -#define XFS_SB_FEAT_INCOMPAT_LOG_ALL 0
> > > +#define XFS_SB_FEAT_INCOMPAT_LOG_XATTRS   (1 << 0)	/* Delayed
> > > Attributes */
> > > +#define XFS_SB_FEAT_INCOMPAT_LOG_ALL \
> > > +	(XFS_SB_FEAT_INCOMPAT_LOG_XATTRS)
> > >  #define XFS_SB_FEAT_INCOMPAT_LOG_UNKNOWN	~XFS_SB_FEAT_INCOMPAT_L
> > > OG_ALL
> > >  static inline bool
> > >  xfs_sb_has_incompat_log_feature(
> > > @@ -413,6 +415,11 @@ xfs_sb_add_incompat_log_features(
> > >  	sbp->sb_features_log_incompat |= features;
> > >  }
> > >  
> > > +static inline bool xfs_sb_version_haslogxattrs(struct xfs_sb *sbp)
> > > +{
> > > +	return xfs_sb_is_v5(sbp) && (sbp->sb_features_log_incompat &
> > > +		 XFS_SB_FEAT_INCOMPAT_LOG_XATTRS);
> > > +}
> > >  
> > >  static inline bool
> > >  xfs_is_quota_inode(struct xfs_sb *sbp, xfs_ino_t ino)
> > > -- 
> > > 2.25.1
> > > 
>