From 8e4bff4cab0ddac6060645b0715210484d02ff40 Mon Sep 17 00:00:00 2001
From: Yuval Adam <_@yuv.al>
Date: Wed, 30 Aug 2017 08:25:59 +0000
Subject: Initial file dump from open source release

---
 fs/nfs/symlink.c | 78 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 78 insertions(+)
 create mode 100644 fs/nfs/symlink.c

(limited to 'fs/nfs/symlink.c')

diff --git a/fs/nfs/symlink.c b/fs/nfs/symlink.c
new file mode 100644
index 00000000..05c9e02f
--- /dev/null
+++ b/fs/nfs/symlink.c
@@ -0,0 +1,78 @@
+/*
+ *  linux/fs/nfs/symlink.c
+ *
+ *  Copyright (C) 1992  Rick Sladkey
+ *
+ *  Optimization changes Copyright (C) 1994 Florian La Roche
+ *
+ *  Jun 7 1999, cache symlink lookups in the page cache.  -DaveM
+ *
+ *  nfs symlink handling code
+ */
+
+#include <linux/time.h>
+#include <linux/errno.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/nfs.h>
+#include <linux/nfs2.h>
+#include <linux/nfs_fs.h>
+#include <linux/pagemap.h>
+#include <linux/stat.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/namei.h>
+
+/* Symlink caching in the page cache is even more simplistic
+ * and straight-forward than readdir caching.
+ */
+
+static int nfs_symlink_filler(struct inode *inode, struct page *page)
+{
+	int error;
+
+	error = NFS_PROTO(inode)->readlink(inode, page, 0, PAGE_SIZE);
+	if (error < 0)
+		goto error;
+	SetPageUptodate(page);
+	unlock_page(page);
+	return 0;
+
+error:
+	SetPageError(page);
+	unlock_page(page);
+	return -EIO;
+}
+
+static void *nfs_follow_link(struct dentry *dentry, struct nameidata *nd)
+{
+	struct inode *inode = dentry->d_inode;
+	struct page *page;
+	void *err;
+
+	err = ERR_PTR(nfs_revalidate_mapping(inode, inode->i_mapping));
+	if (err)
+		goto read_failed;
+	page = read_cache_page(&inode->i_data, 0,
+				(filler_t *)nfs_symlink_filler, inode);
+	if (IS_ERR(page)) {
+		err = page;
+		goto read_failed;
+	}
+	nd_set_link(nd, kmap(page));
+	return page;
+
+read_failed:
+	nd_set_link(nd, err);
+	return NULL;
+}
+
+/*
+ * symlinks can't do much...
+ */
+const struct inode_operations nfs_symlink_inode_operations = {
+	.readlink	= generic_readlink,
+	.follow_link	= nfs_follow_link,
+	.put_link	= page_put_link,
+	.getattr	= nfs_getattr,
+	.setattr	= nfs_setattr,
+};
-- 
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