6 files changed, 50 insertions, 14 deletions

diff --git a/fs/autofs4/dev-ioctl.c b/fs/autofs4/dev-ioctl.c
index 3182c0e68b4..5b570b6efa2 100644
--- a/fs/autofs4/dev-ioctl.c
+++ b/fs/autofs4/dev-ioctl.c
@@ -103,6 +103,9 @@ static struct autofs_dev_ioctl *copy_dev_ioctl(struct autofs_dev_ioctl __user *i
 	if (tmp.size < sizeof(tmp))
 		return ERR_PTR(-EINVAL);
 
+	if (tmp.size > (PATH_MAX + sizeof(tmp)))
+		return ERR_PTR(-ENAMETOOLONG);
+
 	return memdup_user(in, tmp.size);
 }
 
@@ -734,7 +737,7 @@ MODULE_ALIAS_MISCDEV(AUTOFS_MINOR);
 MODULE_ALIAS("devname:autofs");
 
 /* Register/deregister misc character device */
-int autofs_dev_ioctl_init(void)
+int __init autofs_dev_ioctl_init(void)
 {
 	int r;
 
diff --git a/fs/autofs4/expire.c b/fs/autofs4/expire.c
index 3d9d3f5d5dd..394e90b02c5 100644
--- a/fs/autofs4/expire.c
+++ b/fs/autofs4/expire.c
@@ -402,6 +402,20 @@ struct dentry *autofs4_expire_indirect(struct super_block *sb,
 			goto next;
 		}
 
+		if (dentry->d_inode && S_ISLNK(dentry->d_inode->i_mode)) {
+			DPRINTK("checking symlink %p %.*s",
+				dentry, (int)dentry->d_name.len, dentry->d_name.name);
+			/*
+			 * A symlink can't be "busy" in the usual sense so
+			 * just check last used for expire timeout.
+			 */
+			if (autofs4_can_expire(dentry, timeout, do_now)) {
+				expired = dentry;
+				goto found;
+			}
+			goto next;
+		}
+
 		if (simple_empty(dentry))
 			goto next;
 
diff --git a/fs/autofs4/inode.c b/fs/autofs4/inode.c
index a3de082db62..1c55388ae63 100644
--- a/fs/autofs4/inode.c
+++ b/fs/autofs4/inode.c
@@ -210,12 +210,13 @@ int autofs4_fill_super(struct super_block *s, void *data, int silent)
 	int pipefd;
 	struct autofs_sb_info *sbi;
 	struct autofs_info *ino;
-	int pgrp;
+	int pgrp = 0;
 	bool pgrp_set = false;
+	int ret = -EINVAL;
 
 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
 	if (!sbi)
-		goto fail_unlock;
+		return -ENOMEM;
 	DPRINTK("starting up, sbi = %p",sbi);
 
 	s->s_fs_info = sbi;
@@ -249,8 +250,10 @@ int autofs4_fill_super(struct super_block *s, void *data, int silent)
 	 * Get the root inode and dentry, but defer checking for errors.
 	 */
 	ino = autofs4_new_ino(sbi);
-	if (!ino)
+	if (!ino) {
+		ret = -ENOMEM;
 		goto fail_free;
+	}
 	root_inode = autofs4_get_inode(s, S_IFDIR | 0755);
 	root = d_make_root(root_inode);
 	if (!root)
@@ -308,7 +311,8 @@ int autofs4_fill_super(struct super_block *s, void *data, int silent)
 		printk("autofs: could not open pipe file descriptor\n");
 		goto fail_dput;
 	}
-	if (autofs_prepare_pipe(pipe) < 0)
+	ret = autofs_prepare_pipe(pipe);
+	if (ret < 0)
 		goto fail_fput;
 	sbi->pipe = pipe;
 	sbi->pipefd = pipefd;
@@ -336,8 +340,7 @@ fail_free:
 	put_pid(sbi->oz_pgrp);
 	kfree(sbi);
 	s->s_fs_info = NULL;
-fail_unlock:
-	return -EINVAL;
+	return ret;
 }
 
 struct inode *autofs4_get_inode(struct super_block *sb, umode_t mode)
diff --git a/fs/autofs4/root.c b/fs/autofs4/root.c
index 92ef341ba0c..cc87c1abac9 100644
--- a/fs/autofs4/root.c
+++ b/fs/autofs4/root.c
@@ -179,7 +179,7 @@ static struct dentry *autofs4_lookup_active(struct dentry *dentry)
 		spin_lock(&active->d_lock);
 
 		/* Already gone? */
-		if (!d_count(active))
+		if ((int) d_count(active) <= 0)
 			goto next;
 
 		qstr = &active->d_name;
@@ -230,7 +230,7 @@ static struct dentry *autofs4_lookup_expiring(struct dentry *dentry)
 
 		spin_lock(&expiring->d_lock);
 
-		/* Bad luck, we've already been dentry_iput */
+		/* We've already been dentry_iput or unlinked */
 		if (!expiring->d_inode)
 			goto next;
 
@@ -558,7 +558,7 @@ static int autofs4_dir_symlink(struct inode *dir,
 	dget(dentry);
 	atomic_inc(&ino->count);
 	p_ino = autofs4_dentry_ino(dentry->d_parent);
-	if (p_ino && dentry->d_parent != dentry)
+	if (p_ino && !IS_ROOT(dentry))
 		atomic_inc(&p_ino->count);
 
 	dir->i_mtime = CURRENT_TIME;
@@ -593,7 +593,7 @@ static int autofs4_dir_unlink(struct inode *dir, struct dentry *dentry)
 
 	if (atomic_dec_and_test(&ino->count)) {
 		p_ino = autofs4_dentry_ino(dentry->d_parent);
-		if (p_ino && dentry->d_parent != dentry)
+		if (p_ino && !IS_ROOT(dentry))
 			atomic_dec(&p_ino->count);
 	}
 	dput(ino->dentry);
@@ -732,7 +732,7 @@ static int autofs4_dir_mkdir(struct inode *dir, struct dentry *dentry, umode_t m
 	dget(dentry);
 	atomic_inc(&ino->count);
 	p_ino = autofs4_dentry_ino(dentry->d_parent);
-	if (p_ino && dentry->d_parent != dentry)
+	if (p_ino && !IS_ROOT(dentry))
 		atomic_inc(&p_ino->count);
 	inc_nlink(dir);
 	dir->i_mtime = CURRENT_TIME;
diff --git a/fs/autofs4/symlink.c b/fs/autofs4/symlink.c
index f27c094a191..1e8ea192be2 100644
--- a/fs/autofs4/symlink.c
+++ b/fs/autofs4/symlink.c
@@ -14,6 +14,10 @@
 
 static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd)
 {
+	struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
+	struct autofs_info *ino = autofs4_dentry_ino(dentry);
+	if (ino && !autofs4_oz_mode(sbi))
+		ino->last_used = jiffies;
 	nd_set_link(nd, dentry->d_inode->i_private);
 	return NULL;
 }
diff --git a/fs/autofs4/waitq.c b/fs/autofs4/waitq.c
index 689e40d983a..116fd38ee47 100644
--- a/fs/autofs4/waitq.c
+++ b/fs/autofs4/waitq.c
@@ -347,11 +347,23 @@ int autofs4_wait(struct autofs_sb_info *sbi, struct dentry *dentry,
 	struct qstr qstr;
 	char *name;
 	int status, ret, type;
+	pid_t pid;
+	pid_t tgid;
 
 	/* In catatonic mode, we don't wait for nobody */
 	if (sbi->catatonic)
 		return -ENOENT;
 
+	/*
+	 * Try translating pids to the namespace of the daemon.
+	 *
+	 * Zero means failure: we are in an unrelated pid namespace.
+	 */
+	pid = task_pid_nr_ns(current, ns_of_pid(sbi->oz_pgrp));
+	tgid = task_tgid_nr_ns(current, ns_of_pid(sbi->oz_pgrp));
+	if (pid == 0 || tgid == 0)
+		return -ENOENT;
+
 	if (!dentry->d_inode) {
 		/*
 		 * A wait for a negative dentry is invalid for certain
@@ -417,8 +429,8 @@ int autofs4_wait(struct autofs_sb_info *sbi, struct dentry *dentry,
 		wq->ino = autofs4_get_ino(sbi);
 		wq->uid = current_uid();
 		wq->gid = current_gid();
-		wq->pid = current->pid;
-		wq->tgid = current->tgid;
+		wq->pid = pid;
+		wq->tgid = tgid;
 		wq->status = -EINTR; /* Status return if interrupted */
 		wq->wait_ctr = 2;