Re: [PATCH v7 02/19] xfs: Embed struct xfs_name in xfs_da_args

Amir Goldstein
2020-02-24T07:43:28Z

On Mon, Feb 24, 2020 at 9:37 AM Allison Collins
<allison.henderson@oracle.com> wrote:
>
>
>
> On 2/23/20 11:50 PM, Amir Goldstein wrote:
> > On Sun, Feb 23, 2020 at 6:51 PM Allison Collins
> > <allison.henderson@oracle.com> wrote:
> >>
> >>
> >>
> >> On 2/23/20 4:54 AM, Amir Goldstein wrote:
> >>> On Sun, Feb 23, 2020 at 4:07 AM Allison Collins
> >>> <allison.henderson@oracle.com> wrote:
> >>>>
> >>>> This patch embeds an xfs_name in xfs_da_args, replacing the name, namelen, and flags
> >>>> members. This helps to clean up the xfs_da_args structure and make it more uniform
> >>>> with the new xfs_name parameter being passed around.
> >>>>
> >>>> Signed-off-by: Allison Collins <allison.henderson@oracle.com>
> >>>> Reviewed-by: Brian Foster <bfoster@redhat.com>
> >>>> ---
> >>>> fs/xfs/libxfs/xfs_attr.c | 37 +++++++-------
> >>>> fs/xfs/libxfs/xfs_attr_leaf.c | 104 +++++++++++++++++++++-------------------
> >>>> fs/xfs/libxfs/xfs_attr_remote.c | 2 +-
> >>>> fs/xfs/libxfs/xfs_da_btree.c | 6 ++-
> >>>> fs/xfs/libxfs/xfs_da_btree.h | 4 +-
> >>>> fs/xfs/libxfs/xfs_dir2.c | 18 +++----
> >>>> fs/xfs/libxfs/xfs_dir2_block.c | 6 +--
> >>>> fs/xfs/libxfs/xfs_dir2_leaf.c | 6 +--
> >>>> fs/xfs/libxfs/xfs_dir2_node.c | 8 ++--
> >>>> fs/xfs/libxfs/xfs_dir2_sf.c | 30 ++++++------
> >>>> fs/xfs/scrub/attr.c | 12 ++---
> >>>> fs/xfs/xfs_trace.h | 20 ++++----
> >>>> 12 files changed, 130 insertions(+), 123 deletions(-)
> >>>>
> >>>> diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c
> >>>> index 6717f47..9acdb23 100644
> >>>> --- a/fs/xfs/libxfs/xfs_attr.c
> >>>> +++ b/fs/xfs/libxfs/xfs_attr.c
> >>>> @@ -72,13 +72,12 @@ xfs_attr_args_init(
> >>>> args->geo = dp->i_mount->m_attr_geo;
> >>>> args->whichfork = XFS_ATTR_FORK;
> >>>> args->dp = dp;
> >>>> - args->flags = flags;
> >>>> - args->name = name->name;
> >>>> - args->namelen = name->len;
> >>>> - if (args->namelen >= MAXNAMELEN)
> >>>> + memcpy(&args->name, name, sizeof(struct xfs_name));
> >>>
> >>> Maybe xfs_name_copy and xfs_name_equal are in order?
> >> You are suggesting to add xfs_name_copy and xfs_name_equal helpers? I'm
> >> not sure there's a use case yet for xfs_name_equal, at least not in this
> >> set. And I think people indicated that they preferred the memcpy in
> >> past reviews rather than handling each member of the xfs_name struct.
> >> Unless I misunderstood the question, I'm not sure there is much left for
> >> a xfs_name_copy helper to cover that the memcpy does not?
> >>
> >
> > It's fine. The choice between xfs_name_copy and memcpy is
> > mostly personal taste. I did not read through past reviews.
> >
> >>>
> >>>>
> >>>> + /* Use name now stored in args */
> >>>> + name = &args.name;
> >>>> +
> >>>
> >>> It seem that the context of these comments be clear in the future.
> >> You are asking to add more context to the comment? How about:
> >> /*
> >> * Use name now stored in args. Abandon the local name
> >> * parameter as it will not be updated in the subroutines
> >> */
> >>
> >> Does that help some?
> >
> > Can't you just not use local name arg anymore?
> > Instead of re-assigning it and explaining why you do that.
> > Does that gain anything to code readability or anything else?
> Well, with out the set, you cannot use for example name->type anymore,
> you need to use args->name->type. In order to use the local name
> variable again, it needs to be updated. I stumbled across this myself
> when working with it and thought it would be better to fix it right away
> rather than let others run across the same mistake. It seems like a
> subtle and easy thing to overlook otherwise.
>
> I do think it's a bit of a wart that people may not have thought about
> when we talked about adding this patch. Though I don't know that it's a
> big enough deal to drop it either. But I did feel some motivation to at
> least clean it up and make a comment about it.
>

Understood. I have no smart suggestion, so withdrawing my comment.

Thanks,
Amir.