Re: [PATCH v15 06/22] xfs: Separate xfs_attr_node_addname and xfs_attr_node_addname_work

[Allison Henderson <allison.henderson@oracle.com>]

On 2/25/21 9:02 PM, Darrick J. Wong wrote:
> On Thu, Feb 18, 2021 at 09:53:32AM -0700, Allison Henderson wrote:
>> This patch separate xfs_attr_node_addname into two functions.  This will
>> help to make it easier to hoist parts of xfs_attr_node_addname that need
>> state management
>>
>> Signed-off-by: Allison Henderson <allison.henderson@oracle.com>
>> ---
>>   fs/xfs/libxfs/xfs_attr.c | 20 ++++++++++++++++++++
>>   1 file changed, 20 insertions(+)
>>
>> diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c
>> index 205ad26..bee8d3fb 100644
>> --- a/fs/xfs/libxfs/xfs_attr.c
>> +++ b/fs/xfs/libxfs/xfs_attr.c
>> @@ -54,6 +54,7 @@ STATIC int xfs_attr_leaf_hasname(struct xfs_da_args *args, struct xfs_buf **bp);
>>   STATIC int xfs_attr_node_get(xfs_da_args_t *args);
>>   STATIC int xfs_attr_node_addname(xfs_da_args_t *args);
>>   STATIC int xfs_attr_node_removename(xfs_da_args_t *args);
>> +STATIC int xfs_attr_node_addname_work(struct xfs_da_args *args);
>>   STATIC int xfs_attr_node_hasname(xfs_da_args_t *args,
>>   				 struct xfs_da_state **state);
>>   STATIC int xfs_attr_fillstate(xfs_da_state_t *state);
>> @@ -1059,6 +1060,25 @@ xfs_attr_node_addname(
>>   			return error;
>>   	}
>>   
>> +	error = xfs_attr_node_addname_work(args);
>> +out:
>> +	if (state)
>> +		xfs_da_state_free(state);
>> +	if (error)
>> +		return error;
>> +	return retval;
>> +}
>> +
>> +
>> +STATIC
>> +int xfs_attr_node_addname_work(
> 
> What, erm, work does this function do?  Since it survives to the end of
> the patchset, I think this needs a better name (or at least needs a
> comment about what it's actually supposed to do).
To directly answer the question: it's here to help xfs_attr_set_iter not 
be any bigger than it has to. I think we likely struggled with the name 
because it's almost like it's just the "remainder" of the operation that 
doesnt need state management

> 
> AFAICT you're splitting node_addname() into two functions because we're
> at a transaction roll point, and this "_work" function exists to remove
> the copy of the xattr key that has the "INCOMPLETE" bit set (aka the old
> one), right?
Thats about right. Maybe just a quick comment?
/*
  * Removes the old xattr key marked with the INCOMPLETE bit
  */

I suppose we could consider something like 
"xfs_attr_node_addname_remv_incomplete"?  Or 
xfs_attr_node_addname_cleanup? Trying to cram it into the name maybe 
getting a bit wordy too.

Allison
> 
> --D
> 
>> +	struct xfs_da_args		*args)
>> +{
>> +	struct xfs_da_state		*state = NULL;
>> +	struct xfs_da_state_blk		*blk;
>> +	int				retval = 0;
>> +	int				error = 0;
>> +
>>   	/*
>>   	 * Re-find the "old" attribute entry after any split ops. The INCOMPLETE
>>   	 * flag means that we will find the "old" attr, not the "new" one.
>> -- 
>> 2.7.4
>>