xfs: constify the name argument to various directory functions

Various directory functions do not modify their @name parameter,
so mark it const to make that clear.  This will enable us to mark
the global xfs_name_dotdot variable as const to prevent mischief.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

fs/xfs/libxfs/xfs_dir2.c

@@ -54,10 +54,10 @@ xfs_mode_to_ftype(
  */
 xfs_dahash_t
 xfs_ascii_ci_hashname(
-	struct xfs_name	*name)
+	const struct xfs_name	*name)
 {
-	xfs_dahash_t	hash;
-	int		i;
+	xfs_dahash_t		hash;
+	int			i;
 
 	for (i = 0, hash = 0; i < name->len; i++)
 		hash = tolower(name->name[i]) ^ rol32(hash, 7);
@@ -243,7 +243,7 @@ int
 xfs_dir_createname(
 	struct xfs_trans	*tp,
 	struct xfs_inode	*dp,
-	struct xfs_name		*name,
+	const struct xfs_name	*name,
 	xfs_ino_t		inum,		/* new entry inode number */
 	xfs_extlen_t		total)		/* bmap's total block count */
 {
@@ -337,16 +337,16 @@ xfs_dir_cilookup_result(
 
 int
 xfs_dir_lookup(
-	xfs_trans_t	*tp,
-	xfs_inode_t	*dp,
-	struct xfs_name	*name,
-	xfs_ino_t	*inum,		/* out: inode number */
-	struct xfs_name *ci_name)	/* out: actual name if CI match */
+	struct xfs_trans	*tp,
+	struct xfs_inode	*dp,
+	const struct xfs_name	*name,
+	xfs_ino_t		*inum,	  /* out: inode number */
+	struct xfs_name		*ci_name) /* out: actual name if CI match */
 {
-	struct xfs_da_args *args;
-	int		rval;
-	int		v;		/* type-checking value */
-	int		lock_mode;
+	struct xfs_da_args	*args;
+	int			rval;
+	int			v;	  /* type-checking value */
+	int			lock_mode;
 
 	ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
 	XFS_STATS_INC(dp->i_mount, xs_dir_lookup);
@@ -475,7 +475,7 @@ int
 xfs_dir_replace(
 	struct xfs_trans	*tp,
 	struct xfs_inode	*dp,
-	struct xfs_name		*name,		/* name of entry to replace */
+	const struct xfs_name	*name,		/* name of entry to replace */
 	xfs_ino_t		inum,		/* new inode number */
 	xfs_extlen_t		total)		/* bmap's total block count */
 {
@@ -728,7 +728,7 @@ xfs_dir2_namecheck(
 xfs_dahash_t
 xfs_dir2_hashname(
 	struct xfs_mount	*mp,
-	struct xfs_name		*name)
+	const struct xfs_name	*name)
 {
 	if (unlikely(xfs_has_asciici(mp)))
 		return xfs_ascii_ci_hashname(name);

fs/xfs/libxfs/xfs_dir2.h

@@ -39,16 +39,16 @@ extern int xfs_dir_isempty(struct xfs_inode *dp);
 extern int xfs_dir_init(struct xfs_trans *tp, struct xfs_inode *dp,
 				struct xfs_inode *pdp);
 extern int xfs_dir_createname(struct xfs_trans *tp, struct xfs_inode *dp,
-				struct xfs_name *name, xfs_ino_t inum,
+				const struct xfs_name *name, xfs_ino_t inum,
 				xfs_extlen_t tot);
 extern int xfs_dir_lookup(struct xfs_trans *tp, struct xfs_inode *dp,
-				struct xfs_name *name, xfs_ino_t *inum,
+				const struct xfs_name *name, xfs_ino_t *inum,
 				struct xfs_name *ci_name);
 extern int xfs_dir_removename(struct xfs_trans *tp, struct xfs_inode *dp,
 				struct xfs_name *name, xfs_ino_t ino,
 				xfs_extlen_t tot);
 extern int xfs_dir_replace(struct xfs_trans *tp, struct xfs_inode *dp,
-				struct xfs_name *name, xfs_ino_t inum,
+				const struct xfs_name *name, xfs_ino_t inum,
 				xfs_extlen_t tot);
 extern int xfs_dir_canenter(struct xfs_trans *tp, struct xfs_inode *dp,
 				struct xfs_name *name);

fs/xfs/libxfs/xfs_dir2_priv.h

@@ -40,7 +40,7 @@ struct xfs_dir3_icfree_hdr {
 };
 
 /* xfs_dir2.c */
-xfs_dahash_t xfs_ascii_ci_hashname(struct xfs_name *name);
+xfs_dahash_t xfs_ascii_ci_hashname(const struct xfs_name *name);
 enum xfs_dacmp xfs_ascii_ci_compname(struct xfs_da_args *args,
 		const unsigned char *name, int len);
 extern int xfs_dir2_grow_inode(struct xfs_da_args *args, int space,
@@ -201,7 +201,8 @@ xfs_dir2_data_entsize(
 	return round_up(len, XFS_DIR2_DATA_ALIGN);
 }
 
-xfs_dahash_t xfs_dir2_hashname(struct xfs_mount *mp, struct xfs_name *name);
+xfs_dahash_t xfs_dir2_hashname(struct xfs_mount *mp,
+		const struct xfs_name *name);
 enum xfs_dacmp xfs_dir2_compname(struct xfs_da_args *args,
 		const unsigned char *name, int len);
 

fs/xfs/xfs_inode.c

@@ -658,9 +658,9 @@ xfs_ip2xflags(
  */
 int
 xfs_lookup(
-	xfs_inode_t		*dp,
-	struct xfs_name		*name,
-	xfs_inode_t		**ipp,
+	struct xfs_inode	*dp,
+	const struct xfs_name	*name,
+	struct xfs_inode	**ipp,
 	struct xfs_name		*ci_name)
 {
 	xfs_ino_t		inum;

fs/xfs/xfs_inode.h

@@ -402,7 +402,7 @@ enum layout_break_reason {
 
 int		xfs_release(struct xfs_inode *ip);
 void		xfs_inactive(struct xfs_inode *ip);
-int		xfs_lookup(struct xfs_inode *dp, struct xfs_name *name,
+int		xfs_lookup(struct xfs_inode *dp, const struct xfs_name *name,
 			   struct xfs_inode **ipp, struct xfs_name *ci_name);
 int		xfs_create(struct user_namespace *mnt_userns,
 			   struct xfs_inode *dp, struct xfs_name *name,

fs/xfs/xfs_trace.h

@@ -933,7 +933,7 @@ DEFINE_IREF_EVENT(xfs_inode_unpin);
 DEFINE_IREF_EVENT(xfs_inode_unpin_nowait);
 
 DECLARE_EVENT_CLASS(xfs_namespace_class,
-	TP_PROTO(struct xfs_inode *dp, struct xfs_name *name),
+	TP_PROTO(struct xfs_inode *dp, const struct xfs_name *name),
 	TP_ARGS(dp, name),
 	TP_STRUCT__entry(
 		__field(dev_t, dev)
@@ -956,7 +956,7 @@ DECLARE_EVENT_CLASS(xfs_namespace_class,
 
 #define DEFINE_NAMESPACE_EVENT(name) \
 DEFINE_EVENT(xfs_namespace_class, name, \
-	TP_PROTO(struct xfs_inode *dp, struct xfs_name *name), \
+	TP_PROTO(struct xfs_inode *dp, const struct xfs_name *name), \
 	TP_ARGS(dp, name))
 DEFINE_NAMESPACE_EVENT(xfs_remove);
 DEFINE_NAMESPACE_EVENT(xfs_link);