Re: [PATCH V2 2/3] xfs: factor out xrep_reset_fork_to_extents helper for scrub/repair

[Eric Sandeen <sandeen@redhat.com>]

On 10/5/26 3:20 PM, Darrick J. Wong wrote:
> On Mon, Oct 05, 2026 at 02:11:37PM -0500, Eric Sandeen wrote:
>> The open-coded ~10 line series of steps to reset a fork to empty extents
>> format is repeated 3 times; factor this out into a helper to eliminate
>> cut and paste.

...

>> diff --git a/fs/xfs/scrub/repair.c b/fs/xfs/scrub/repair.c
>> index c2a437416227..8385308c852f 100644
>> --- a/fs/xfs/scrub/repair.c
>> +++ b/fs/xfs/scrub/repair.c
>> @@ -882,6 +882,32 @@ xrep_ino_ensure_extent_count(
>>  	return 0;
>>  }
>>  
>> +/* Discard the contents of this fork and initialize as empty extent-format. */
>> +void
>> +xrep_reset_fork_to_extents(
>> +	struct xfs_scrub	*sc,
>> +	int			whichfork)
>> +{
>> +	struct xfs_ifork	*ifp = xfs_ifork_ptr(sc->ip, whichfork);
>> +	uint			ilog_flags = XFS_ILOG_CORE;
>> +
>> +	ASSERT(whichfork == XFS_DATA_FORK || whichfork == XFS_ATTR_FORK);
>> +
>> +	if (whichfork == XFS_DATA_FORK)
>> +		ilog_flags |= XFS_ILOG_DDATA;
>> +	else
>> +		ilog_flags |= XFS_ILOG_ADATA;
> 
> Nit pick:

I thought about a case switch but it seemed excessive for 2 choices.
My ASSERT does make sure we have one or the other valid value... *shrug*

> 	switch (whichfork) {
> 	case XFS_DATA_FORK:
> 		ilog_flags |= XFS_ILOG_DDATA;
> 		break;
> 	case XFS_ATTR_FORK:
> 		ilog_flags |= XFS_ILOG_ADATA;
> 		break;
> 	default:
> 		ASSERT(0);
> 		return;

I guess this has the advantage of kinda handling an unknown whichfork or
XFS_COW_FORK, though who knows what happens to callers that get a do-nothing
return at that point?
> 	}
> 
> Either way this looks like a good hoist to me, so
> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
> 
> --D
> 
>> +
>> +	xfs_idestroy_fork(ifp);
>> +	ifp->if_format = XFS_DINODE_FMT_EXTENTS;
>> +	ifp->if_nextents = 0;
>> +	ifp->if_bytes = 0;
>> +	ifp->if_data = NULL;
>> +	ifp->if_height = 0;
>> +
>> +	xfs_trans_log_inode(sc->tp, sc->ip, ilog_flags);
>> +}
>> +
>>  /*
>>   * Initialize all the btree cursors for an AG repair except for the btree that
>>   * we're rebuilding.
>> diff --git a/fs/xfs/scrub/repair.h b/fs/xfs/scrub/repair.h
>> index 2bb125c4f9bf..c1ba462e4426 100644
>> --- a/fs/xfs/scrub/repair.h
>> +++ b/fs/xfs/scrub/repair.h
>> @@ -81,6 +81,7 @@ int xrep_setup_xfbtree(struct xfs_scrub *sc, const char *descr);
>>  int xrep_ino_ensure_extent_count(struct xfs_scrub *sc, int whichfork,
>>  		xfs_extnum_t nextents);
>>  int xrep_reset_perag_resv(struct xfs_scrub *sc);
>> +void xrep_reset_fork_to_extents(struct xfs_scrub *sc, int whichfork);
>>  int xrep_bmap(struct xfs_scrub *sc, int whichfork, bool allow_unwritten);
>>  int xrep_metadata_inode_forks(struct xfs_scrub *sc);
>>  int xrep_setup_ag_rmapbt(struct xfs_scrub *sc);
>> diff --git a/fs/xfs/scrub/symlink_repair.c b/fs/xfs/scrub/symlink_repair.c
>> index 181961364233..9f6901905bfd 100644
>> --- a/fs/xfs/scrub/symlink_repair.c
>> +++ b/fs/xfs/scrub/symlink_repair.c
>> @@ -303,20 +303,8 @@ xrep_symlink_swap_prep(
>>  	 * to an empty extent list in preparation for the atomic mapping
>>  	 * exchange.
>>  	 */
>> -	if (ip_local) {
>> -		struct xfs_ifork	*ifp;
>> -
>> -		ifp = xfs_ifork_ptr(sc->ip, XFS_DATA_FORK);
>> -		xfs_idestroy_fork(ifp);
>> -		ifp->if_format = XFS_DINODE_FMT_EXTENTS;
>> -		ifp->if_nextents = 0;
>> -		ifp->if_bytes = 0;
>> -		ifp->if_data = NULL;
>> -		ifp->if_height = 0;
>> -
>> -		xfs_trans_log_inode(sc->tp, sc->ip,
>> -				XFS_ILOG_CORE | XFS_ILOG_DDATA);
>> -	}
>> +	if (ip_local)
>> +		xrep_reset_fork_to_extents(sc, XFS_DATA_FORK);
>>  
>>  	return 0;
>>  }
>> -- 
>> 2.55.0
>>
>>
>