xfs: make if_data a void pointer

The xfs_ifork structure currently has a union of the if_root void pointer
and the if_data char pointer.  In either case it is an opaque pointer
that depends on the fork format.  Replace the union with a single if_data
void pointer as that is what almost all callers want.  Only the symlink
NULL termination code in xfs_init_local_fork actually needs a new local
variable now.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>

Author: Christoph Hellwig

fs/xfs/libxfs/xfs_attr.c

@@ -1049,9 +1049,8 @@ xfs_attr_set(
 
 static inline int xfs_attr_sf_totsize(struct xfs_inode *dp)
 {
-	struct xfs_attr_shortform *sf;
+	struct xfs_attr_shortform *sf = dp->i_af.if_data;
 
-	sf = (struct xfs_attr_shortform *)dp->i_af.if_u1.if_data;
 	return be16_to_cpu(sf->hdr.totsize);
 }
 

fs/xfs/libxfs/xfs_attr_leaf.c

@@ -691,7 +691,7 @@ xfs_attr_shortform_create(
 	if (ifp->if_format == XFS_DINODE_FMT_EXTENTS)
 		ifp->if_format = XFS_DINODE_FMT_LOCAL;
 	xfs_idata_realloc(dp, sizeof(*hdr), XFS_ATTR_FORK);
-	hdr = (struct xfs_attr_sf_hdr *)ifp->if_u1.if_data;
+	hdr = ifp->if_data;
 	memset(hdr, 0, sizeof(*hdr));
 	hdr->totsize = cpu_to_be16(sizeof(*hdr));
 	xfs_trans_log_inode(args->trans, dp, XFS_ILOG_CORE | XFS_ILOG_ADATA);
@@ -712,14 +712,13 @@ xfs_attr_sf_findname(
 	struct xfs_attr_sf_entry **sfep,
 	unsigned int		 *basep)
 {
-	struct xfs_attr_shortform *sf;
+	struct xfs_attr_shortform *sf = args->dp->i_af.if_data;
 	struct xfs_attr_sf_entry *sfe;
 	unsigned int		base = sizeof(struct xfs_attr_sf_hdr);
 	int			size = 0;
 	int			end;
 	int			i;
 
-	sf = (struct xfs_attr_shortform *)args->dp->i_af.if_u1.if_data;
 	sfe = &sf->list[0];
 	end = sf->hdr.count;
 	for (i = 0; i < end; sfe = xfs_attr_sf_nextentry(sfe),
@@ -751,29 +750,25 @@ xfs_attr_shortform_add(
 	struct xfs_da_args		*args,
 	int				forkoff)
 {
-	struct xfs_attr_shortform	*sf;
+	struct xfs_inode		*dp = args->dp;
+	struct xfs_mount		*mp = dp->i_mount;
+	struct xfs_ifork		*ifp = &dp->i_af;
+	struct xfs_attr_shortform	*sf = ifp->if_data;
 	struct xfs_attr_sf_entry	*sfe;
 	int				offset, size;
-	struct xfs_mount		*mp;
-	struct xfs_inode		*dp;
-	struct xfs_ifork		*ifp;
 
 	trace_xfs_attr_sf_add(args);
 
-	dp = args->dp;
-	mp = dp->i_mount;
 	dp->i_forkoff = forkoff;
 
-	ifp = &dp->i_af;
 	ASSERT(ifp->if_format == XFS_DINODE_FMT_LOCAL);
-	sf = (struct xfs_attr_shortform *)ifp->if_u1.if_data;
 	if (xfs_attr_sf_findname(args, &sfe, NULL) == -EEXIST)
 		ASSERT(0);
 
 	offset = (char *)sfe - (char *)sf;
 	size = xfs_attr_sf_entsize_byname(args->namelen, args->valuelen);
 	xfs_idata_realloc(dp, size, XFS_ATTR_FORK);
-	sf = (struct xfs_attr_shortform *)ifp->if_u1.if_data;
+	sf = ifp->if_data;
 	sfe = (struct xfs_attr_sf_entry *)((char *)sf + offset);
 
 	sfe->namelen = args->namelen;
@@ -811,20 +806,16 @@ int
 xfs_attr_sf_removename(
 	struct xfs_da_args		*args)
 {
-	struct xfs_attr_shortform	*sf;
+	struct xfs_inode		*dp = args->dp;
+	struct xfs_mount		*mp = dp->i_mount;
+	struct xfs_attr_shortform	*sf = dp->i_af.if_data;
 	struct xfs_attr_sf_entry	*sfe;
 	int				size = 0, end, totsize;
 	unsigned int			base;
-	struct xfs_mount		*mp;
-	struct xfs_inode		*dp;
 	int				error;
 
 	trace_xfs_attr_sf_remove(args);
 
-	dp = args->dp;
-	mp = dp->i_mount;
-	sf = (struct xfs_attr_shortform *)dp->i_af.if_u1.if_data;
-
 	error = xfs_attr_sf_findname(args, &sfe, &base);
 
 	/*
@@ -878,18 +869,17 @@ xfs_attr_sf_removename(
  */
 /*ARGSUSED*/
 int
-xfs_attr_shortform_lookup(xfs_da_args_t *args)
+xfs_attr_shortform_lookup(
+	struct xfs_da_args		*args)
 {
-	struct xfs_attr_shortform *sf;
-	struct xfs_attr_sf_entry *sfe;
-	int i;
-	struct xfs_ifork *ifp;
+	struct xfs_ifork		*ifp = &args->dp->i_af;
+	struct xfs_attr_shortform	*sf = ifp->if_data;
+	struct xfs_attr_sf_entry	*sfe;
+	int				i;
 
 	trace_xfs_attr_sf_lookup(args);
 
-	ifp = &args->dp->i_af;
 	ASSERT(ifp->if_format == XFS_DINODE_FMT_LOCAL);
-	sf = (struct xfs_attr_shortform *)ifp->if_u1.if_data;
 	sfe = &sf->list[0];
 	for (i = 0; i < sf->hdr.count;
 				sfe = xfs_attr_sf_nextentry(sfe), i++) {
@@ -909,14 +899,13 @@ xfs_attr_shortform_lookup(xfs_da_args_t *args)
  */
 int
 xfs_attr_shortform_getvalue(
-	struct xfs_da_args	*args)
+	struct xfs_da_args		*args)
 {
-	struct xfs_attr_shortform *sf;
-	struct xfs_attr_sf_entry *sfe;
-	int			i;
+	struct xfs_attr_shortform	*sf = args->dp->i_af.if_data;
+	struct xfs_attr_sf_entry	*sfe;
+	int				i;
 
 	ASSERT(args->dp->i_af.if_format == XFS_DINODE_FMT_LOCAL);
-	sf = (struct xfs_attr_shortform *)args->dp->i_af.if_u1.if_data;
 	sfe = &sf->list[0];
 	for (i = 0; i < sf->hdr.count;
 				sfe = xfs_attr_sf_nextentry(sfe), i++) {
@@ -933,25 +922,22 @@ int
 xfs_attr_shortform_to_leaf(
 	struct xfs_da_args		*args)
 {
-	struct xfs_inode		*dp;
-	struct xfs_attr_shortform	*sf;
+	struct xfs_inode		*dp = args->dp;
+	struct xfs_ifork		*ifp = &dp->i_af;
+	struct xfs_attr_shortform	*sf = ifp->if_data;
 	struct xfs_attr_sf_entry	*sfe;
 	struct xfs_da_args		nargs;
 	char				*tmpbuffer;
 	int				error, i, size;
 	xfs_dablk_t			blkno;
 	struct xfs_buf			*bp;
-	struct xfs_ifork		*ifp;
 
 	trace_xfs_attr_sf_to_leaf(args);
 
-	dp = args->dp;
-	ifp = &dp->i_af;
-	sf = (struct xfs_attr_shortform *)ifp->if_u1.if_data;
 	size = be16_to_cpu(sf->hdr.totsize);
 	tmpbuffer = kmem_alloc(size, 0);
 	ASSERT(tmpbuffer != NULL);
-	memcpy(tmpbuffer, ifp->if_u1.if_data, size);
+	memcpy(tmpbuffer, ifp->if_data, size);
 	sf = (struct xfs_attr_shortform *)tmpbuffer;
 
 	xfs_idata_realloc(dp, -size, XFS_ATTR_FORK);

fs/xfs/libxfs/xfs_bmap.c

@@ -747,7 +747,7 @@ xfs_bmap_local_to_extents_empty(
 	ASSERT(ifp->if_nextents == 0);
 
 	xfs_bmap_forkoff_reset(ip, whichfork);
-	ifp->if_u1.if_root = NULL;
+	ifp->if_data = NULL;
 	ifp->if_height = 0;
 	ifp->if_format = XFS_DINODE_FMT_EXTENTS;
 	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
@@ -832,7 +832,7 @@ xfs_bmap_local_to_extents(
 	xfs_bmap_local_to_extents_empty(tp, ip, whichfork);
 	flags |= XFS_ILOG_CORE;
 
-	ifp->if_u1.if_root = NULL;
+	ifp->if_data = NULL;
 	ifp->if_height = 0;
 
 	rec.br_startoff = 0;

fs/xfs/libxfs/xfs_dir2.c

@@ -196,7 +196,7 @@ xfs_dir_isempty(
 		return 1;
 	if (dp->i_disk_size > xfs_inode_data_fork_size(dp))
 		return 0;
-	sfp = (xfs_dir2_sf_hdr_t *)dp->i_df.if_u1.if_data;
+	sfp = dp->i_df.if_data;
 	return !sfp->count;
 }
 

fs/xfs/libxfs/xfs_dir2_block.c

@@ -1089,7 +1089,7 @@ xfs_dir2_sf_to_block(
 	int			newoffset;	/* offset from current entry */
 	unsigned int		offset = geo->data_entry_offset;
 	xfs_dir2_sf_entry_t	*sfep;		/* sf entry pointer */
-	xfs_dir2_sf_hdr_t	*oldsfp;	/* old shortform header  */
+	struct xfs_dir2_sf_hdr	*oldsfp = ifp->if_data;
 	xfs_dir2_sf_hdr_t	*sfp;		/* shortform header  */
 	__be16			*tagp;		/* end of data entry */
 	struct xfs_name		name;
@@ -1099,10 +1099,8 @@ xfs_dir2_sf_to_block(
 	ASSERT(ifp->if_format == XFS_DINODE_FMT_LOCAL);
 	ASSERT(dp->i_disk_size >= offsetof(struct xfs_dir2_sf_hdr, parent));
 
-	oldsfp = (xfs_dir2_sf_hdr_t *)ifp->if_u1.if_data;
-
 	ASSERT(ifp->if_bytes == dp->i_disk_size);
-	ASSERT(ifp->if_u1.if_data != NULL);
+	ASSERT(oldsfp != NULL);
 	ASSERT(dp->i_disk_size >= xfs_dir2_sf_hdr_size(oldsfp->i8count));
 	ASSERT(dp->i_df.if_nextents == 0);