autofs4: keep symlink body in inode->i_private

gets rid of all ->free()/->u.symlink machinery in autofs; we simply
keep symlink bodies in inode->i_private and free them in ->evict_inode().

Acked-by: Ian Kent <[e-mail]>
Signed-off-by: Al Viro <[e-mail]>

fs/autofs4/autofs_i.h

···
 
 	mode_t	mode;
 	size_t	size;
-
-	void (*free)(struct autofs_info *);
-	union {
-		const char *symlink;
-	} u;
 };
 
 #define AUTOFS_INF_EXPIRING	(1<<0) /* dentry is in the process of expiring */

fs/autofs4/inode.c

···
 #include "autofs_i.h"
 #include <linux/module.h>
 
-static void ino_lnkfree(struct autofs_info *ino)
-{
-	if (ino->u.symlink) {
-		kfree(ino->u.symlink);
-		ino->u.symlink = NULL;
-	}
-}
-
 struct autofs_info *autofs4_init_ino(struct autofs_info *ino,
 				     struct autofs_sb_info *sbi, mode_t mode)
 {
···
 
 	ino->sbi = sbi;
 
-	if (reinit && ino->free)
-		(ino->free)(ino);
-
-	memset(&ino->u, 0, sizeof(ino->u));
-
-	ino->free = NULL;
-
-	if (S_ISLNK(mode))
-		ino->free = ino_lnkfree;
-
 	return ino;
 }
 
···
 		ino->dentry->d_fsdata = NULL;
 		ino->dentry = NULL;
 	}
-	if (ino->free)
-		(ino->free)(ino);
 	kfree(ino);
 }
 
···
 	return 0;
 }
 
+static void autofs4_evict_inode(struct inode *inode)
+{
+	end_writeback(inode);
+	kfree(inode->i_private);
+}
+
 static const struct super_operations autofs4_sops = {
 	.statfs		= simple_statfs,
 	.show_options	= autofs4_show_options,
+	.evict_inode	= autofs4_evict_inode,
 };
 
 enum {Opt_err, Opt_fd, Opt_uid, Opt_gid, Opt_pgrp, Opt_minproto, Opt_maxproto,

fs/autofs4/root.c

···
 			kfree(ino);
 		return -ENOMEM;
 	}
+	inode->i_private = cp;
 	d_add(dentry, inode);
 
 	dentry->d_fsdata = ino;
···
 	if (p_ino && dentry->d_parent != dentry)
 		atomic_inc(&p_ino->count);
 
-	ino->u.symlink = cp;
 	dir->i_mtime = CURRENT_TIME;
 
 	return 0;

fs/autofs4/symlink.c

···
 
 static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd)
 {
-	struct autofs_info *ino = autofs4_dentry_ino(dentry);
-	nd_set_link(nd, (char *)ino->u.symlink);
+	nd_set_link(nd, dentry->d_inode->i_private);
 	return NULL;
 }