Re: [PATCH v4 03/17] xfs: Embed struct xfs_name in xfs_da_args

Darrick J. Wong
2019-11-08T01:27:53Z

On Wed, Nov 06, 2019 at 06:27:47PM -0700, Allison Collins 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 | 36 +++++++-------
> fs/xfs/libxfs/xfs_attr_leaf.c | 106 +++++++++++++++++++++-------------------
> fs/xfs/libxfs/xfs_attr_remote.c | 2 +-
> fs/xfs/libxfs/xfs_da_btree.c | 5 +-
> 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, 128 insertions(+), 125 deletions(-)
>
> diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c
> index 5a9624a..b77b985 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)
> + name->type = flags;

Is there a purpose for modifying the caller's @name, instead of setting
args.name.type = flags after the memcpy?

> + memcpy(&args->name, name, sizeof(struct xfs_name));
> + if (args->name.len >= MAXNAMELEN)
> return -EFAULT; /* match IRIX behaviour */
>
> - args->hashval = xfs_da_hashname(args->name, args->namelen);
> + args->hashval = xfs_da_hashname(args->name.name, args->name.len);
> return 0;
> }
>
> @@ -236,7 +235,7 @@ xfs_attr_try_sf_addname(
> * Commit the shortform mods, and we're done.
> * NOTE: this is also the error path (EEXIST, etc).
> */
> - if (!error && (args->flags & ATTR_KERNOTIME) == 0)
> + if (!error && (args->name.type & ATTR_KERNOTIME) == 0)
> xfs_trans_ichgtime(args->trans, dp, XFS_ICHGTIME_CHG);
>
> if (mp->m_flags & XFS_MOUNT_WSYNC)
> @@ -357,6 +356,9 @@ xfs_attr_set(
> if (error)
> return error;
>
> + /* Use name now stored in args */
> + name = &args.name;

You could probably set this as part of the variable declaration, e.g.

struct xfs_name *name = &args.name;

> +
> 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(args.name.len, valuelen);

If you're going to keep the convenience variable @name, then please use
it throughout the function.

>
> error = xfs_bmap_add_attrfork(dp, sf_size, rsvd);
> if (error)

<snip>

> diff --git a/fs/xfs/libxfs/xfs_da_btree.c b/fs/xfs/libxfs/xfs_da_btree.c
> index 4fd1223..129ec09 100644
> --- a/fs/xfs/libxfs/xfs_da_btree.c
> +++ b/fs/xfs/libxfs/xfs_da_btree.c
> @@ -2040,8 +2040,9 @@ xfs_da_compname(
> const unsigned char *name,
> int len)
> {
> - return (args->namelen == len && memcmp(args->name, name, len) == 0) ?
> - XFS_CMP_EXACT : XFS_CMP_DIFFERENT;

Wow that's gross. :)

if (args->name.len == len && !memcmp(args->name.name, name, len))
return XFS_CMP_EXACT;

return XFS_CMP_DIFFERENT;

Hmm, is that better?

The rest looks reasonable...

--D