proc/self: use generic_readlink

The /proc/self and /proc/self-thread symlinks have separate but identical
functionality for reading and following.  This cleanup utilizes
generic_readlink to remove the duplication.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

fs/proc/self.c

@@ -6,18 +6,6 @@
 /*
  * /proc/self:
  */
-static int proc_self_readlink(struct dentry *dentry, char __user *buffer,
-			      int buflen)
-{
-	struct pid_namespace *ns = dentry->d_sb->s_fs_info;
-	pid_t tgid = task_tgid_nr_ns(current, ns);
-	char tmp[PROC_NUMBUF];
-	if (!tgid)
-		return -ENOENT;
-	sprintf(tmp, "%d", tgid);
-	return readlink_copy(buffer, buflen, tmp);
-}
-
 static const char *proc_self_get_link(struct dentry *dentry,
 				      struct inode *inode,
 				      struct delayed_call *done)
@@ -38,7 +26,7 @@ static const char *proc_self_get_link(struct dentry *dentry,
 }
 
 static const struct inode_operations proc_self_inode_operations = {
-	.readlink	= proc_self_readlink,
+	.readlink	= generic_readlink,
 	.get_link	= proc_self_get_link,
 };
 

fs/proc/thread_self.c

@@ -6,19 +6,6 @@
 /*
  * /proc/thread_self:
  */
-static int proc_thread_self_readlink(struct dentry *dentry, char __user *buffer,
-			      int buflen)
-{
-	struct pid_namespace *ns = dentry->d_sb->s_fs_info;
-	pid_t tgid = task_tgid_nr_ns(current, ns);
-	pid_t pid = task_pid_nr_ns(current, ns);
-	char tmp[PROC_NUMBUF + 6 + PROC_NUMBUF];
-	if (!pid)
-		return -ENOENT;
-	sprintf(tmp, "%d/task/%d", tgid, pid);
-	return readlink_copy(buffer, buflen, tmp);
-}
-
 static const char *proc_thread_self_get_link(struct dentry *dentry,
 					     struct inode *inode,
 					     struct delayed_call *done)
@@ -40,7 +27,7 @@ static const char *proc_thread_self_get_link(struct dentry *dentry,
 }
 
 static const struct inode_operations proc_thread_self_inode_operations = {
-	.readlink	= proc_thread_self_readlink,
+	.readlink	= generic_readlink,
 	.get_link	= proc_thread_self_get_link,
 };