nsfs: clean-up ns_get_path() signature to return int

ns_get_path() and ns_get_path_cb() only ever return either NULL or an
ERR_PTR. It is far more idiomatic to simply return an integer, and it
makes all of the callers of ns_get_path() more straightforward to read.

Fixes: e149ed2b805f ("take the targets of /proc/*/ns/* symlinks to separate fs")
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

2 files changed, 17 insertions, 18 deletions

diff --git a/fs/nsfs.c b/fs/nsfs.c
index a0431642c6b5..f3d2833c5781 100644
--- a/fs/nsfs.c
+++ b/fs/nsfs.c
@@ -52,7 +52,7 @@ static void nsfs_evict(struct inode *inode)
 	ns->ops->put(ns);
 }
 
-static void *__ns_get_path(struct path *path, struct ns_common *ns)
+static int __ns_get_path(struct path *path, struct ns_common *ns)
 {
 	struct vfsmount *mnt = nsfs_mnt;
 	struct dentry *dentry;
@@ -71,13 +71,13 @@ static void *__ns_get_path(struct path *path, struct ns_common *ns)
 got_it:
 	path->mnt = mntget(mnt);
 	path->dentry = dentry;
-	return NULL;
+	return 0;
 slow:
 	rcu_read_unlock();
 	inode = new_inode_pseudo(mnt->mnt_sb);
 	if (!inode) {
 		ns->ops->put(ns);
-		return ERR_PTR(-ENOMEM);
+		return -ENOMEM;
 	}
 	inode->i_ino = ns->inum;
 	inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
@@ -89,7 +89,7 @@ slow:
 	dentry = d_alloc_anon(mnt->mnt_sb);
 	if (!dentry) {
 		iput(inode);
-		return ERR_PTR(-ENOMEM);
+		return -ENOMEM;
 	}
 	d_instantiate(dentry, inode);
 	dentry->d_fsdata = (void *)ns->ops;
@@ -98,23 +98,22 @@ slow:
 		d_delete(dentry);	/* make sure ->d_prune() does nothing */
 		dput(dentry);
 		cpu_relax();
-		return ERR_PTR(-EAGAIN);
+		return -EAGAIN;
 	}
 	goto got_it;
 }
 
-void *ns_get_path_cb(struct path *path, ns_get_path_helper_t *ns_get_cb,
+int ns_get_path_cb(struct path *path, ns_get_path_helper_t *ns_get_cb,
 		     void *private_data)
 {
-	void *ret;
+	int ret;
 
 	do {
 		struct ns_common *ns = ns_get_cb(private_data);
 		if (!ns)
-			return ERR_PTR(-ENOENT);
-
+			return -ENOENT;
 		ret = __ns_get_path(path, ns);
-	} while (ret == ERR_PTR(-EAGAIN));
+	} while (ret == -EAGAIN);
 
 	return ret;
 }
@@ -131,7 +130,7 @@ static struct ns_common *ns_get_path_task(void *private_data)
 	return args->ns_ops->get(args->task);
 }
 
-void *ns_get_path(struct path *path, struct task_struct *task,
+int ns_get_path(struct path *path, struct task_struct *task,
 		  const struct proc_ns_operations *ns_ops)
 {
 	struct ns_get_path_task_args args = {
@@ -147,7 +146,7 @@ int open_related_ns(struct ns_common *ns,
 {
 	struct path path = {};
 	struct file *f;
-	void *err;
+	int err;
 	int fd;
 
 	fd = get_unused_fd_flags(O_CLOEXEC);
@@ -164,11 +163,11 @@ int open_related_ns(struct ns_common *ns,
 		}
 
 		err = __ns_get_path(&path, relative);
-	} while (err == ERR_PTR(-EAGAIN));
+	} while (err == -EAGAIN);
 
-	if (IS_ERR(err)) {
+	if (err) {
 		put_unused_fd(fd);
-		return PTR_ERR(err);
+		return err;
 	}
 
 	f = dentry_open(&path, O_RDONLY, current_cred());
diff --git a/fs/proc/namespaces.c b/fs/proc/namespaces.c
index dd2b35f78b09..08dd94df1a66 100644
--- a/fs/proc/namespaces.c
+++ b/fs/proc/namespaces.c
@@ -42,14 +42,14 @@ static const char *proc_ns_get_link(struct dentry *dentry,
 	const struct proc_ns_operations *ns_ops = PROC_I(inode)->ns_ops;
 	struct task_struct *task;
 	struct path ns_path;
-	void *error = ERR_PTR(-EACCES);
+	int error = -EACCES;
 
 	if (!dentry)
 		return ERR_PTR(-ECHILD);
 
 	task = get_proc_task(inode);
 	if (!task)
-		return error;
+		return ERR_PTR(-EACCES);
 
 	if (ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) {
 		error = ns_get_path(&ns_path, task, ns_ops);
@@ -57,7 +57,7 @@ static const char *proc_ns_get_link(struct dentry *dentry,
 			nd_jump_link(&ns_path);
 	}
 	put_task_struct(task);
-	return error;
+	return ERR_PTR(error);
 }
 
 static int proc_ns_readlink(struct dentry *dentry, char __user *buffer, int buflen)