init android origin source code

1 files changed, 67 insertions, 0 deletions

diff --git a/ANDROID_3.4.5/fs/jffs2/symlink.c b/ANDROID_3.4.5/fs/jffs2/symlink.c
new file mode 100644
index 00000000..6e563332
--- /dev/null
+++ b/ANDROID_3.4.5/fs/jffs2/symlink.c
@@ -0,0 +1,67 @@
+/*
+ * JFFS2 -- Journalling Flash File System, Version 2.
+ *
+ * Copyright © 2001-2007 Red Hat, Inc.
+ *
+ * Created by David Woodhouse <dwmw2@infradead.org>
+ *
+ * For licensing information, see the file 'LICENCE' in this directory.
+ *
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/namei.h>
+#include "nodelist.h"
+
+static void *jffs2_follow_link(struct dentry *dentry, struct nameidata *nd);
+
+const struct inode_operations jffs2_symlink_inode_operations =
+{
+	.readlink =	generic_readlink,
+	.follow_link =	jffs2_follow_link,
+	.get_acl =	jffs2_get_acl,
+	.setattr =	jffs2_setattr,
+	.setxattr =	jffs2_setxattr,
+	.getxattr =	jffs2_getxattr,
+	.listxattr =	jffs2_listxattr,
+	.removexattr =	jffs2_removexattr
+};
+
+static void *jffs2_follow_link(struct dentry *dentry, struct nameidata *nd)
+{
+	struct jffs2_inode_info *f = JFFS2_INODE_INFO(dentry->d_inode);
+	char *p = (char *)f->target;
+
+	/*
+	 * We don't acquire the f->sem mutex here since the only data we
+	 * use is f->target.
+	 *
+	 * 1. If we are here the inode has already built and f->target has
+	 * to point to the target path.
+	 * 2. Nobody uses f->target (if the inode is symlink's inode). The
+	 * exception is inode freeing function which frees f->target. But
+	 * it can't be called while we are here and before VFS has
+	 * stopped using our f->target string which we provide by means of
+	 * nd_set_link() call.
+	 */
+
+	if (!p) {
+		pr_err("%s(): can't find symlink target\n", __func__);
+		p = ERR_PTR(-EIO);
+	}
+	jffs2_dbg(1, "%s(): target path is '%s'\n",
+		  __func__, (char *)f->target);
+
+	nd_set_link(nd, p);
+
+	/*
+	 * We will unlock the f->sem mutex but VFS will use the f->target string. This is safe
+	 * since the only way that may cause f->target to be changed is iput() operation.
+	 * But VFS will not use f->target after iput() has been called.
+	 */
+	return NULL;
+}
+