Re: [PATCH 01/21] xfs: refactor log recovery item sorting into a generic dispatch structure

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

On Wed, Apr 29, 2020 at 10:53:09PM -0700, Christoph Hellwig wrote:
> On Wed, Apr 29, 2020 at 05:47:41PM -0700, Darrick J. Wong wrote:
> > +extern const struct xlog_recover_item_type xlog_icreate_item_type;
> > +extern const struct xlog_recover_item_type xlog_buf_item_type;
> > +extern const struct xlog_recover_item_type xlog_inode_item_type;
> > +extern const struct xlog_recover_item_type xlog_dquot_item_type;
> > +extern const struct xlog_recover_item_type xlog_quotaoff_item_type;
> > +extern const struct xlog_recover_item_type xlog_bmap_intent_item_type;
> > +extern const struct xlog_recover_item_type xlog_bmap_done_item_type;
> > +extern const struct xlog_recover_item_type xlog_extfree_intent_item_type;
> > +extern const struct xlog_recover_item_type xlog_extfree_done_item_type;
> > +extern const struct xlog_recover_item_type xlog_rmap_intent_item_type;
> > +extern const struct xlog_recover_item_type xlog_rmap_done_item_type;
> > +extern const struct xlog_recover_item_type xlog_refcount_intent_item_type;
> > +extern const struct xlog_recover_item_type xlog_refcount_done_item_type;
> 
> I'd prefer if we didn't have to expose these structures, but had a
> xlog_register_recovery_item helper that just adds them to a list or
> array.

I can look into making a register function and do lookups, but that's
a lot of indirection to save ~15 or so externs.

> >  typedef struct xlog_recover_item {
> >  	struct list_head	ri_list;
> > -	int			ri_type;
> >  	int			ri_cnt;	/* count of regions found */
> >  	int			ri_total;	/* total regions */
> >  	xfs_log_iovec_t		*ri_buf;	/* ptr to regions buffer */
> > +	const struct xlog_recover_item_type *ri_type;
> >  } xlog_recover_item_t;
> 
> Btw, killing the xlog_recover_item_t typedef might be a worthwhile prep
> patch.

Hrm, ok....

> > --- a/fs/xfs/xfs_buf_item.c
> > +++ b/fs/xfs/xfs_buf_item.c
> > @@ -17,7 +17,6 @@
> >  #include "xfs_trace.h"
> >  #include "xfs_log.h"
> >  
> > -
> >  kmem_zone_t	*xfs_buf_item_zone;
> >  
> >  static inline struct xfs_buf_log_item *BUF_ITEM(struct xfs_log_item *lip)
> 
> Spurious whitespace change in a file not otherwise touched.

Fixed.

> >  
> > @@ -107,3 +109,14 @@ xfs_icreate_log(
> >  	tp->t_flags |= XFS_TRANS_DIRTY;
> >  	set_bit(XFS_LI_DIRTY, &icp->ic_item.li_flags);
> >  }
> > +
> > +static enum xlog_recover_reorder
> > +xlog_icreate_reorder(
> > +		struct xlog_recover_item *item)
> > +{
> > +	return XLOG_REORDER_BUFFER_LIST;
> > +}
> 
> It might be worth to throw in a comment why icreate items got to
> the buffer list.
> 
> > +		return 0;
> > +#ifdef CONFIG_XFS_QUOTA
> > +	case XFS_LI_DQUOT:
> > +		item->ri_type = &xlog_dquot_item_type;
> > +		return 0;
> > +	case XFS_LI_QUOTAOFF:
> > +		item->ri_type = &xlog_quotaoff_item_type;
> > +		return 0;
> > +#endif /* CONFIG_XFS_QUOTA */
> > +	default:
> > +		return -EFSCORRUPTED;
> > +	}
> > +}
> 
> Quote recovery support currently is unconditionalẏ  Making it
> conditional on CONFIG_XFS_QUOTA means a kernel without that config
> will now fail to recover a file system with quota updates in the log.

Heh, I hadn't realized that quota recovery always works even if quotas
are disabled.  Ok, xfs_dquot_recovery.c it is...

--D