autofs: copy autofs4 to autofs

Copy source files from the autofs4 directory to the autofs directory.

Link: http://lkml.kernel.org/r/152626705013.28589.931913083997578251.stgit@pluto.themaw.netSigned-off-by: Ian Kent <raven@themaw.net>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/autofs/autofs_i.h

+/*
+ *  Copyright 1997-1998 Transmeta Corporation - All Rights Reserved
+ *  Copyright 2005-2006 Ian Kent <raven@themaw.net>
+ *
+ * This file is part of the Linux kernel and is made available under
+ * the terms of the GNU General Public License, version 2, or at your
+ * option, any later version, incorporated herein by reference.
+ */
+
+/* Internal header file for autofs */
+
+#include <linux/auto_fs.h>
+#include <linux/auto_dev-ioctl.h>
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/time.h>
+#include <linux/string.h>
+#include <linux/wait.h>
+#include <linux/sched.h>
+#include <linux/mount.h>
+#include <linux/namei.h>
+#include <linux/uaccess.h>
+#include <linux/mutex.h>
+#include <linux/spinlock.h>
+#include <linux/list.h>
+#include <linux/completion.h>
+#include <asm/current.h>
+
+/* This is the range of ioctl() numbers we claim as ours */
+#define AUTOFS_IOC_FIRST     AUTOFS_IOC_READY
+#define AUTOFS_IOC_COUNT     32
+
+#define AUTOFS_DEV_IOCTL_IOC_FIRST	(AUTOFS_DEV_IOCTL_VERSION)
+#define AUTOFS_DEV_IOCTL_IOC_COUNT \
+	(AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD - AUTOFS_DEV_IOCTL_VERSION_CMD)
+
+#ifdef pr_fmt
+#undef pr_fmt
+#endif
+#define pr_fmt(fmt) KBUILD_MODNAME ":pid:%d:%s: " fmt, current->pid, __func__
+
+/*
+ * Unified info structure.  This is pointed to by both the dentry and
+ * inode structures.  Each file in the filesystem has an instance of this
+ * structure.  It holds a reference to the dentry, so dentries are never
+ * flushed while the file exists.  All name lookups are dealt with at the
+ * dentry level, although the filesystem can interfere in the validation
+ * process.  Readdir is implemented by traversing the dentry lists.
+ */
+struct autofs_info {
+	struct dentry	*dentry;
+	struct inode	*inode;
+
+	int		flags;
+
+	struct completion expire_complete;
+
+	struct list_head active;
+	int active_count;
+
+	struct list_head expiring;
+
+	struct autofs_sb_info *sbi;
+	unsigned long last_used;
+	atomic_t count;
+
+	kuid_t uid;
+	kgid_t gid;
+};
+
+#define AUTOFS_INF_EXPIRING	(1<<0) /* dentry in the process of expiring */
+#define AUTOFS_INF_WANT_EXPIRE	(1<<1) /* the dentry is being considered
+					* for expiry, so RCU_walk is
+					* not permitted.  If it progresses to
+					* actual expiry attempt, the flag is
+					* not cleared when EXPIRING is set -
+					* in that case it gets cleared only
+					* when it comes to clearing EXPIRING.
+					*/
+#define AUTOFS_INF_PENDING	(1<<2) /* dentry pending mount */
+
+struct autofs_wait_queue {
+	wait_queue_head_t queue;
+	struct autofs_wait_queue *next;
+	autofs_wqt_t wait_queue_token;
+	/* We use the following to see what we are waiting for */
+	struct qstr name;
+	u32 dev;
+	u64 ino;
+	kuid_t uid;
+	kgid_t gid;
+	pid_t pid;
+	pid_t tgid;
+	/* This is for status reporting upon return */
+	int status;
+	unsigned int wait_ctr;
+};
+
+#define AUTOFS_SBI_MAGIC 0x6d4a556d
+
+struct autofs_sb_info {
+	u32 magic;
+	int pipefd;
+	struct file *pipe;
+	struct pid *oz_pgrp;
+	int catatonic;
+	int version;
+	int sub_version;
+	int min_proto;
+	int max_proto;
+	unsigned long exp_timeout;
+	unsigned int type;
+	struct super_block *sb;
+	struct mutex wq_mutex;
+	struct mutex pipe_mutex;
+	spinlock_t fs_lock;
+	struct autofs_wait_queue *queues; /* Wait queue pointer */
+	spinlock_t lookup_lock;
+	struct list_head active_list;
+	struct list_head expiring_list;
+	struct rcu_head rcu;
+};
+
+static inline struct autofs_sb_info *autofs_sbi(struct super_block *sb)
+{
+	return (struct autofs_sb_info *)(sb->s_fs_info);
+}
+
+static inline struct autofs_info *autofs_dentry_ino(struct dentry *dentry)
+{
+	return (struct autofs_info *)(dentry->d_fsdata);
+}
+
+/* autofs_oz_mode(): do we see the man behind the curtain?  (The
+ * processes which do manipulations for us in user space sees the raw
+ * filesystem without "magic".)
+ */
+static inline int autofs_oz_mode(struct autofs_sb_info *sbi)
+{
+	return sbi->catatonic || task_pgrp(current) == sbi->oz_pgrp;
+}
+
+struct inode *autofs_get_inode(struct super_block *, umode_t);
+void autofs_free_ino(struct autofs_info *);
+
+/* Expiration */
+int is_autofs_dentry(struct dentry *);
+int autofs_expire_wait(const struct path *path, int rcu_walk);
+int autofs_expire_run(struct super_block *, struct vfsmount *,
+		      struct autofs_sb_info *,
+		      struct autofs_packet_expire __user *);
+int autofs_do_expire_multi(struct super_block *sb, struct vfsmount *mnt,
+			   struct autofs_sb_info *sbi, int when);
+int autofs_expire_multi(struct super_block *, struct vfsmount *,
+			struct autofs_sb_info *, int __user *);
+struct dentry *autofs_expire_direct(struct super_block *sb,
+				    struct vfsmount *mnt,
+				    struct autofs_sb_info *sbi, int how);
+struct dentry *autofs_expire_indirect(struct super_block *sb,
+				      struct vfsmount *mnt,
+				      struct autofs_sb_info *sbi, int how);
+
+/* Device node initialization */
+
+int autofs_dev_ioctl_init(void);
+void autofs_dev_ioctl_exit(void);
+
+/* Operations structures */
+
+extern const struct inode_operations autofs_symlink_inode_operations;
+extern const struct inode_operations autofs_dir_inode_operations;
+extern const struct file_operations autofs_dir_operations;
+extern const struct file_operations autofs_root_operations;
+extern const struct dentry_operations autofs_dentry_operations;
+
+/* VFS automount flags management functions */
+static inline void __managed_dentry_set_managed(struct dentry *dentry)
+{
+	dentry->d_flags |= (DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT);
+}
+
+static inline void managed_dentry_set_managed(struct dentry *dentry)
+{
+	spin_lock(&dentry->d_lock);
+	__managed_dentry_set_managed(dentry);
+	spin_unlock(&dentry->d_lock);
+}
+
+static inline void __managed_dentry_clear_managed(struct dentry *dentry)
+{
+	dentry->d_flags &= ~(DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT);
+}
+
+static inline void managed_dentry_clear_managed(struct dentry *dentry)
+{
+	spin_lock(&dentry->d_lock);
+	__managed_dentry_clear_managed(dentry);
+	spin_unlock(&dentry->d_lock);
+}
+
+/* Initializing function */
+
+int autofs_fill_super(struct super_block *, void *, int);
+struct autofs_info *autofs_new_ino(struct autofs_sb_info *);
+void autofs_clean_ino(struct autofs_info *);
+
+static inline int autofs_prepare_pipe(struct file *pipe)
+{
+	if (!(pipe->f_mode & FMODE_CAN_WRITE))
+		return -EINVAL;
+	if (!S_ISFIFO(file_inode(pipe)->i_mode))
+		return -EINVAL;
+	/* We want a packet pipe */
+	pipe->f_flags |= O_DIRECT;
+	return 0;
+}
+
+/* Queue management functions */
+
+int autofs_wait(struct autofs_sb_info *,
+		 const struct path *, enum autofs_notify);
+int autofs_wait_release(struct autofs_sb_info *, autofs_wqt_t, int);
+void autofs_catatonic_mode(struct autofs_sb_info *);
+
+static inline u32 autofs_get_dev(struct autofs_sb_info *sbi)
+{
+	return new_encode_dev(sbi->sb->s_dev);
+}
+
+static inline u64 autofs_get_ino(struct autofs_sb_info *sbi)
+{
+	return d_inode(sbi->sb->s_root)->i_ino;
+}
+
+static inline void __autofs_add_expiring(struct dentry *dentry)
+{
+	struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
+	struct autofs_info *ino = autofs_dentry_ino(dentry);
+
+	if (ino) {
+		if (list_empty(&ino->expiring))
+			list_add(&ino->expiring, &sbi->expiring_list);
+	}
+}
+
+static inline void autofs_add_expiring(struct dentry *dentry)
+{
+	struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
+	struct autofs_info *ino = autofs_dentry_ino(dentry);
+
+	if (ino) {
+		spin_lock(&sbi->lookup_lock);
+		if (list_empty(&ino->expiring))
+			list_add(&ino->expiring, &sbi->expiring_list);
+		spin_unlock(&sbi->lookup_lock);
+	}
+}
+
+static inline void autofs_del_expiring(struct dentry *dentry)
+{
+	struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
+	struct autofs_info *ino = autofs_dentry_ino(dentry);
+
+	if (ino) {
+		spin_lock(&sbi->lookup_lock);
+		if (!list_empty(&ino->expiring))
+			list_del_init(&ino->expiring);
+		spin_unlock(&sbi->lookup_lock);
+	}
+}
+
+void autofs_kill_sb(struct super_block *);

fs/autofs/init.c

+/*
+ * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
+ *
+ * This file is part of the Linux kernel and is made available under
+ * the terms of the GNU General Public License, version 2, or at your
+ * option, any later version, incorporated herein by reference.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include "autofs_i.h"
+
+static struct dentry *autofs_mount(struct file_system_type *fs_type,
+	int flags, const char *dev_name, void *data)
+{
+	return mount_nodev(fs_type, flags, data, autofs_fill_super);
+}
+
+static struct file_system_type autofs_fs_type = {
+	.owner		= THIS_MODULE,
+	.name		= "autofs",
+	.mount		= autofs_mount,
+	.kill_sb	= autofs_kill_sb,
+};
+MODULE_ALIAS_FS("autofs");
+
+static int __init init_autofs_fs(void)
+{
+	int err;
+
+	autofs_dev_ioctl_init();
+
+	err = register_filesystem(&autofs_fs_type);
+	if (err)
+		autofs_dev_ioctl_exit();
+
+	return err;
+}
+
+static void __exit exit_autofs_fs(void)
+{
+	autofs_dev_ioctl_exit();
+	unregister_filesystem(&autofs_fs_type);
+}
+
+module_init(init_autofs_fs)
+module_exit(exit_autofs_fs)
+MODULE_LICENSE("GPL");

fs/autofs/inode.c

+/*
+ * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
+ * Copyright 2005-2006 Ian Kent <raven@themaw.net>
+ *
+ * This file is part of the Linux kernel and is made available under
+ * the terms of the GNU General Public License, version 2, or at your
+ * option, any later version, incorporated herein by reference.
+ */
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/file.h>
+#include <linux/seq_file.h>
+#include <linux/pagemap.h>
+#include <linux/parser.h>
+#include <linux/bitops.h>
+#include <linux/magic.h>
+#include "autofs_i.h"
+#include <linux/module.h>
+
+struct autofs_info *autofs_new_ino(struct autofs_sb_info *sbi)
+{
+	struct autofs_info *ino;
+
+	ino = kzalloc(sizeof(*ino), GFP_KERNEL);
+	if (ino) {
+		INIT_LIST_HEAD(&ino->active);
+		INIT_LIST_HEAD(&ino->expiring);
+		ino->last_used = jiffies;
+		ino->sbi = sbi;
+	}
+	return ino;
+}
+
+void autofs_clean_ino(struct autofs_info *ino)
+{
+	ino->uid = GLOBAL_ROOT_UID;
+	ino->gid = GLOBAL_ROOT_GID;
+	ino->last_used = jiffies;
+}
+
+void autofs_free_ino(struct autofs_info *ino)
+{
+	kfree(ino);
+}
+
+void autofs_kill_sb(struct super_block *sb)
+{
+	struct autofs_sb_info *sbi = autofs_sbi(sb);
+
+	/*
+	 * In the event of a failure in get_sb_nodev the superblock
+	 * info is not present so nothing else has been setup, so
+	 * just call kill_anon_super when we are called from
+	 * deactivate_super.
+	 */
+	if (sbi) {
+		/* Free wait queues, close pipe */
+		autofs_catatonic_mode(sbi);
+		put_pid(sbi->oz_pgrp);
+	}
+
+	pr_debug("shutting down\n");
+	kill_litter_super(sb);
+	if (sbi)
+		kfree_rcu(sbi, rcu);
+}
+
+static int autofs_show_options(struct seq_file *m, struct dentry *root)
+{
+	struct autofs_sb_info *sbi = autofs_sbi(root->d_sb);
+	struct inode *root_inode = d_inode(root->d_sb->s_root);
+
+	if (!sbi)
+		return 0;
+
+	seq_printf(m, ",fd=%d", sbi->pipefd);
+	if (!uid_eq(root_inode->i_uid, GLOBAL_ROOT_UID))
+		seq_printf(m, ",uid=%u",
+			from_kuid_munged(&init_user_ns, root_inode->i_uid));
+	if (!gid_eq(root_inode->i_gid, GLOBAL_ROOT_GID))
+		seq_printf(m, ",gid=%u",
+			from_kgid_munged(&init_user_ns, root_inode->i_gid));
+	seq_printf(m, ",pgrp=%d", pid_vnr(sbi->oz_pgrp));
+	seq_printf(m, ",timeout=%lu", sbi->exp_timeout/HZ);
+	seq_printf(m, ",minproto=%d", sbi->min_proto);
+	seq_printf(m, ",maxproto=%d", sbi->max_proto);
+
+	if (autofs_type_offset(sbi->type))
+		seq_printf(m, ",offset");
+	else if (autofs_type_direct(sbi->type))
+		seq_printf(m, ",direct");
+	else
+		seq_printf(m, ",indirect");
+#ifdef CONFIG_CHECKPOINT_RESTORE
+	if (sbi->pipe)
+		seq_printf(m, ",pipe_ino=%ld", file_inode(sbi->pipe)->i_ino);
+	else
+		seq_printf(m, ",pipe_ino=-1");
+#endif
+	return 0;
+}
+
+static void autofs_evict_inode(struct inode *inode)
+{
+	clear_inode(inode);
+	kfree(inode->i_private);
+}
+
+static const struct super_operations autofs_sops = {
+	.statfs		= simple_statfs,
+	.show_options	= autofs_show_options,
+	.evict_inode	= autofs_evict_inode,
+};
+
+enum {Opt_err, Opt_fd, Opt_uid, Opt_gid, Opt_pgrp, Opt_minproto, Opt_maxproto,
+	Opt_indirect, Opt_direct, Opt_offset};
+
+static const match_table_t tokens = {
+	{Opt_fd, "fd=%u"},
+	{Opt_uid, "uid=%u"},
+	{Opt_gid, "gid=%u"},
+	{Opt_pgrp, "pgrp=%u"},
+	{Opt_minproto, "minproto=%u"},
+	{Opt_maxproto, "maxproto=%u"},
+	{Opt_indirect, "indirect"},
+	{Opt_direct, "direct"},
+	{Opt_offset, "offset"},
+	{Opt_err, NULL}
+};
+
+static int parse_options(char *options, int *pipefd, kuid_t *uid, kgid_t *gid,
+			 int *pgrp, bool *pgrp_set, unsigned int *type,
+			 int *minproto, int *maxproto)
+{
+	char *p;
+	substring_t args[MAX_OPT_ARGS];
+	int option;
+
+	*uid = current_uid();
+	*gid = current_gid();
+
+	*minproto = AUTOFS_MIN_PROTO_VERSION;
+	*maxproto = AUTOFS_MAX_PROTO_VERSION;
+
+	*pipefd = -1;
+
+	if (!options)
+		return 1;
+
+	while ((p = strsep(&options, ",")) != NULL) {
+		int token;
+
+		if (!*p)
+			continue;
+
+		token = match_token(p, tokens, args);
+		switch (token) {
+		case Opt_fd:
+			if (match_int(args, pipefd))
+				return 1;
+			break;
+		case Opt_uid:
+			if (match_int(args, &option))
+				return 1;
+			*uid = make_kuid(current_user_ns(), option);
+			if (!uid_valid(*uid))
+				return 1;
+			break;
+		case Opt_gid:
+			if (match_int(args, &option))
+				return 1;
+			*gid = make_kgid(current_user_ns(), option);
+			if (!gid_valid(*gid))
+				return 1;
+			break;
+		case Opt_pgrp:
+			if (match_int(args, &option))
+				return 1;
+			*pgrp = option;
+			*pgrp_set = true;
+			break;
+		case Opt_minproto:
+			if (match_int(args, &option))
+				return 1;
+			*minproto = option;
+			break;
+		case Opt_maxproto:
+			if (match_int(args, &option))
+				return 1;
+			*maxproto = option;
+			break;
+		case Opt_indirect:
+			set_autofs_type_indirect(type);
+			break;
+		case Opt_direct:
+			set_autofs_type_direct(type);
+			break;
+		case Opt_offset:
+			set_autofs_type_offset(type);
+			break;
+		default:
+			return 1;
+		}
+	}
+	return (*pipefd < 0);
+}
+
+int autofs_fill_super(struct super_block *s, void *data, int silent)
+{
+	struct inode *root_inode;
+	struct dentry *root;
+	struct file *pipe;
+	int pipefd;
+	struct autofs_sb_info *sbi;
+	struct autofs_info *ino;
+	int pgrp = 0;
+	bool pgrp_set = false;
+	int ret = -EINVAL;
+
+	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
+	if (!sbi)
+		return -ENOMEM;
+	pr_debug("starting up, sbi = %p\n", sbi);
+
+	s->s_fs_info = sbi;
+	sbi->magic = AUTOFS_SBI_MAGIC;
+	sbi->pipefd = -1;
+	sbi->pipe = NULL;
+	sbi->catatonic = 1;
+	sbi->exp_timeout = 0;
+	sbi->oz_pgrp = NULL;
+	sbi->sb = s;
+	sbi->version = 0;
+	sbi->sub_version = 0;
+	set_autofs_type_indirect(&sbi->type);
+	sbi->min_proto = 0;
+	sbi->max_proto = 0;
+	mutex_init(&sbi->wq_mutex);
+	mutex_init(&sbi->pipe_mutex);
+	spin_lock_init(&sbi->fs_lock);
+	sbi->queues = NULL;
+	spin_lock_init(&sbi->lookup_lock);
+	INIT_LIST_HEAD(&sbi->active_list);
+	INIT_LIST_HEAD(&sbi->expiring_list);
+	s->s_blocksize = 1024;
+	s->s_blocksize_bits = 10;
+	s->s_magic = AUTOFS_SUPER_MAGIC;
+	s->s_op = &autofs_sops;
+	s->s_d_op = &autofs_dentry_operations;
+	s->s_time_gran = 1;
+
+	/*
+	 * Get the root inode and dentry, but defer checking for errors.
+	 */
+	ino = autofs_new_ino(sbi);
+	if (!ino) {
+		ret = -ENOMEM;
+		goto fail_free;
+	}
+	root_inode = autofs_get_inode(s, S_IFDIR | 0755);
+	root = d_make_root(root_inode);
+	if (!root)
+		goto fail_ino;
+	pipe = NULL;
+
+	root->d_fsdata = ino;
+
+	/* Can this call block? */
+	if (parse_options(data, &pipefd, &root_inode->i_uid, &root_inode->i_gid,
+			  &pgrp, &pgrp_set, &sbi->type, &sbi->min_proto,
+			  &sbi->max_proto)) {
+		pr_err("called with bogus options\n");
+		goto fail_dput;
+	}
+
+	/* Test versions first */
+	if (sbi->max_proto < AUTOFS_MIN_PROTO_VERSION ||
+	    sbi->min_proto > AUTOFS_MAX_PROTO_VERSION) {
+		pr_err("kernel does not match daemon version "
+		       "daemon (%d, %d) kernel (%d, %d)\n",
+		       sbi->min_proto, sbi->max_proto,
+		       AUTOFS_MIN_PROTO_VERSION, AUTOFS_MAX_PROTO_VERSION);
+		goto fail_dput;
+	}
+
+	/* Establish highest kernel protocol version */
+	if (sbi->max_proto > AUTOFS_MAX_PROTO_VERSION)
+		sbi->version = AUTOFS_MAX_PROTO_VERSION;
+	else
+		sbi->version = sbi->max_proto;
+	sbi->sub_version = AUTOFS_PROTO_SUBVERSION;
+
+	if (pgrp_set) {
+		sbi->oz_pgrp = find_get_pid(pgrp);
+		if (!sbi->oz_pgrp) {
+			pr_err("could not find process group %d\n",
+				pgrp);
+			goto fail_dput;
+		}
+	} else {
+		sbi->oz_pgrp = get_task_pid(current, PIDTYPE_PGID);
+	}
+
+	if (autofs_type_trigger(sbi->type))
+		__managed_dentry_set_managed(root);
+
+	root_inode->i_fop = &autofs_root_operations;
+	root_inode->i_op = &autofs_dir_inode_operations;
+
+	pr_debug("pipe fd = %d, pgrp = %u\n", pipefd, pid_nr(sbi->oz_pgrp));
+	pipe = fget(pipefd);
+
+	if (!pipe) {
+		pr_err("could not open pipe file descriptor\n");
+		goto fail_put_pid;
+	}
+	ret = autofs_prepare_pipe(pipe);
+	if (ret < 0)
+		goto fail_fput;
+	sbi->pipe = pipe;
+	sbi->pipefd = pipefd;
+	sbi->catatonic = 0;
+
+	/*
+	 * Success! Install the root dentry now to indicate completion.
+	 */
+	s->s_root = root;
+	return 0;
+
+	/*
+	 * Failure ... clean up.
+	 */
+fail_fput:
+	pr_err("pipe file descriptor does not contain proper ops\n");
+	fput(pipe);
+fail_put_pid:
+	put_pid(sbi->oz_pgrp);
+fail_dput:
+	dput(root);
+	goto fail_free;
+fail_ino:
+	autofs_free_ino(ino);
+fail_free:
+	kfree(sbi);
+	s->s_fs_info = NULL;
+	return ret;
+}
+
+struct inode *autofs_get_inode(struct super_block *sb, umode_t mode)
+{
+	struct inode *inode = new_inode(sb);
+
+	if (inode == NULL)
+		return NULL;
+
+	inode->i_mode = mode;
+	if (sb->s_root) {
+		inode->i_uid = d_inode(sb->s_root)->i_uid;
+		inode->i_gid = d_inode(sb->s_root)->i_gid;
+	}
+	inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
+	inode->i_ino = get_next_ino();
+
+	if (S_ISDIR(mode)) {
+		set_nlink(inode, 2);
+		inode->i_op = &autofs_dir_inode_operations;
+		inode->i_fop = &autofs_dir_operations;
+	} else if (S_ISLNK(mode)) {
+		inode->i_op = &autofs_symlink_inode_operations;
+	} else
+		WARN_ON(1);
+
+	return inode;
+}

fs/autofs/symlink.c

+/*
+ * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
+ *
+ * This file is part of the Linux kernel and is made available under
+ * the terms of the GNU General Public License, version 2, or at your
+ * option, any later version, incorporated herein by reference.
+ */
+
+#include "autofs_i.h"
+
+static const char *autofs_get_link(struct dentry *dentry,
+				   struct inode *inode,
+				   struct delayed_call *done)
+{
+	struct autofs_sb_info *sbi;
+	struct autofs_info *ino;
+
+	if (!dentry)
+		return ERR_PTR(-ECHILD);
+	sbi = autofs_sbi(dentry->d_sb);
+	ino = autofs_dentry_ino(dentry);
+	if (ino && !autofs_oz_mode(sbi))
+		ino->last_used = jiffies;
+	return d_inode(dentry)->i_private;
+}
+
+const struct inode_operations autofs_symlink_inode_operations = {
+	.get_link	= autofs_get_link
+};