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

Amir Goldstein
2020-02-23T11:54:30Z

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?

>
> + /* Use name now stored in args */
> + name = &args.name;
> +

It seem that the context of these comments be clear in the future.

> args.value = value;
> args.valuelen = valuelen;
> args.op_flags = XFS_DA_OP_ADDNAME | XFS_DA_OP_OKNOENT;
> @@ -372,7 +374,7 @@ xfs_attr_set(
> */
> if (XFS_IFORK_Q(dp) == 0) {
> int sf_size = sizeof(xfs_attr_sf_hdr_t) +
> - XFS_ATTR_SF_ENTSIZE_BYNAME(args.namelen, valuelen);
> + XFS_ATTR_SF_ENTSIZE_BYNAME(name->len, valuelen);
>
> error = xfs_bmap_add_attrfork(dp, sf_size, rsvd);
> if (error)
> @@ -457,6 +459,9 @@ xfs_attr_remove(
> if (error)
> return error;
>
> + /* Use name now stored in args */
> + name = &args.name;
> +
> /*
> * we have no control over the attribute names that userspace passes us
> * to remove, so we have to allow the name lookup prior to attribute
> @@ -532,10 +537,10 @@ xfs_attr_shortform_addname(xfs_da_args_t *args)
> trace_xfs_attr_sf_addname(args);
>
> retval = xfs_attr_shortform_lookup(args);
> - if ((args->flags & ATTR_REPLACE) && (retval == -ENOATTR)) {
> + if ((args->name.type & ATTR_REPLACE) && (retval == -ENOATTR)) {
> return retval;
> } else if (retval == -EEXIST) {
> - if (args->flags & ATTR_CREATE)
> + if (args->name.type & ATTR_CREATE)
> return retval;
> retval = xfs_attr_shortform_remove(args);
> if (retval)
> @@ -545,15 +550,15 @@ xfs_attr_shortform_addname(xfs_da_args_t *args)
> * that the leaf format add routine won't trip over the attr
> * not being around.
> */
> - args->flags &= ~ATTR_REPLACE;
> + args->name.type &= ~ATTR_REPLACE;

This doesn't look good it looks like a hack.

Even if want to avoid growing struct xfs_name we can store two shorts instead
of overloading int type with flags.
type doesn't even need more than a single byte, because XFS_DIR3_FT_WHT
is not used and will never be used on-disk.

Thanks,
Amir.