1 files changed, 134 insertions, 0 deletions
diff --git a/fs/ext4/symlink.c b/fs/ext4/symlink.c
new file mode 100644
index 0000000000..75bf1f8884
--- /dev/null
+++ b/fs/ext4/symlink.c
@@ -0,0 +1,134 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  linux/fs/ext4/symlink.c
+ *
+ * Only fast symlinks left here - the rest is done by generic code. AV, 1999
+ *
+ * Copyright (C) 1992, 1993, 1994, 1995
+ * Remy Card (card@masi.ibp.fr)
+ * Laboratoire MASI - Institut Blaise Pascal
+ * Universite Pierre et Marie Curie (Paris VI)
+ *
+ *  from
+ *
+ *  linux/fs/minix/symlink.c
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *
+ *  ext4 symlink handling code
+ */
+
+#include <linux/fs.h>
+#include <linux/namei.h>
+#include "ext4.h"
+#include "xattr.h"
+
+static const char *ext4_encrypted_get_link(struct dentry *dentry,
+					   struct inode *inode,
+					   struct delayed_call *done)
+{
+	struct buffer_head *bh = NULL;
+	const void *caddr;
+	unsigned int max_size;
+	const char *paddr;
+
+	if (!dentry)
+		return ERR_PTR(-ECHILD);
+
+	if (ext4_inode_is_fast_symlink(inode)) {
+		caddr = EXT4_I(inode)->i_data;
+		max_size = sizeof(EXT4_I(inode)->i_data);
+	} else {
+		bh = ext4_bread(NULL, inode, 0, 0);
+		if (IS_ERR(bh))
+			return ERR_CAST(bh);
+		if (!bh) {
+			EXT4_ERROR_INODE(inode, "bad symlink.");
+			return ERR_PTR(-EFSCORRUPTED);
+		}
+		caddr = bh->b_data;
+		max_size = inode->i_sb->s_blocksize;
+	}
+
+	paddr = fscrypt_get_symlink(inode, caddr, max_size, done);
+	brelse(bh);
+	return paddr;
+}
+
+static int ext4_encrypted_symlink_getattr(struct mnt_idmap *idmap,
+					  const struct path *path,
+					  struct kstat *stat, u32 request_mask,
+					  unsigned int query_flags)
+{
+	ext4_getattr(idmap, path, stat, request_mask, query_flags);
+
+	return fscrypt_symlink_getattr(path, stat);
+}
+
+static void ext4_free_link(void *bh)
+{
+	brelse(bh);
+}
+
+static const char *ext4_get_link(struct dentry *dentry, struct inode *inode,
+				 struct delayed_call *callback)
+{
+	struct buffer_head *bh;
+	char *inline_link;
+
+	/*
+	 * Create a new inlined symlink is not supported, just provide a
+	 * method to read the leftovers.
+	 */
+	if (ext4_has_inline_data(inode)) {
+		if (!dentry)
+			return ERR_PTR(-ECHILD);
+
+		inline_link = ext4_read_inline_link(inode);
+		if (!IS_ERR(inline_link))
+			set_delayed_call(callback, kfree_link, inline_link);
+		return inline_link;
+	}
+
+	if (!dentry) {
+		bh = ext4_getblk(NULL, inode, 0, EXT4_GET_BLOCKS_CACHED_NOWAIT);
+		if (IS_ERR(bh))
+			return ERR_CAST(bh);
+		if (!bh || !ext4_buffer_uptodate(bh))
+			return ERR_PTR(-ECHILD);
+	} else {
+		bh = ext4_bread(NULL, inode, 0, 0);
+		if (IS_ERR(bh))
+			return ERR_CAST(bh);
+		if (!bh) {
+			EXT4_ERROR_INODE(inode, "bad symlink.");
+			return ERR_PTR(-EFSCORRUPTED);
+		}
+	}
+
+	set_delayed_call(callback, ext4_free_link, bh);
+	nd_terminate_link(bh->b_data, inode->i_size,
+			  inode->i_sb->s_blocksize - 1);
+	return bh->b_data;
+}
+
+const struct inode_operations ext4_encrypted_symlink_inode_operations = {
+	.get_link	= ext4_encrypted_get_link,
+	.setattr	= ext4_setattr,
+	.getattr	= ext4_encrypted_symlink_getattr,
+	.listxattr	= ext4_listxattr,
+};
+
+const struct inode_operations ext4_symlink_inode_operations = {
+	.get_link	= ext4_get_link,
+	.setattr	= ext4_setattr,
+	.getattr	= ext4_getattr,
+	.listxattr	= ext4_listxattr,
+};
+
+const struct inode_operations ext4_fast_symlink_inode_operations = {
+	.get_link	= simple_get_link,
+	.setattr	= ext4_setattr,
+	.getattr	= ext4_getattr,
+	.listxattr	= ext4_listxattr,
+};