Import of Linus's Linux 1.1.68

1 files changed, 127 insertions, 0 deletions

diff --git a/fs/ext2/symlink.c b/fs/ext2/symlink.c
new file mode 100644
index 000000000..7d85ed74c
--- /dev/null
+++ b/fs/ext2/symlink.c
@@ -0,0 +1,127 @@
+/*
+ *  linux/fs/ext2/symlink.c
+ *
+ *  Copyright (C) 1992, 1993, 1994  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
+ *
+ *  ext2 symlink handling code
+ */
+
+#include <asm/segment.h>
+
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/ext2_fs.h>
+#include <linux/sched.h>
+#include <linux/stat.h>
+
+static int ext2_readlink (struct inode *, char *, int);
+static int ext2_follow_link (struct inode *, struct inode *, int, int,
+			       struct inode **);
+
+/*
+ * symlinks can't do much...
+ */
+struct inode_operations ext2_symlink_inode_operations = {
+	NULL,			/* no file-operations */
+	NULL,			/* create */
+	NULL,			/* lookup */
+	NULL,			/* link */
+	NULL,			/* unlink */
+	NULL,			/* symlink */
+	NULL,			/* mkdir */
+	NULL,			/* rmdir */
+	NULL,			/* mknod */
+	NULL,			/* rename */
+	ext2_readlink,		/* readlink */
+	ext2_follow_link,	/* follow_link */
+	NULL,			/* bmap */
+	NULL,			/* truncate */
+	NULL,			/* permission */
+	NULL			/* smap */
+};
+
+static int ext2_follow_link(struct inode * dir, struct inode * inode,
+			    int flag, int mode, struct inode ** res_inode)
+{
+	int error;
+	struct buffer_head * bh = NULL;
+	char * link;
+
+	*res_inode = NULL;
+	if (!dir) {
+		dir = current->fs->root;
+		dir->i_count++;
+	}
+	if (!inode) {
+		iput (dir);
+		return -ENOENT;
+	}
+	if (!S_ISLNK(inode->i_mode)) {
+		iput (dir);
+		*res_inode = inode;
+		return 0;
+	}
+	if (current->link_count > 5) {
+		iput (dir);
+		iput (inode);
+		return -ELOOP;
+	}
+	if (inode->i_blocks) {
+		if (!(bh = ext2_bread (inode, 0, 0, &error))) {
+			iput (dir);
+			iput (inode);
+			return -EIO;
+		}
+		link = bh->b_data;
+	} else
+		link = (char *) inode->u.ext2_i.i_data;
+	current->link_count++;
+	error = open_namei (link, flag, mode, res_inode, dir);
+	current->link_count--;
+	iput (inode);
+	if (bh)
+		brelse (bh);
+	return error;
+}
+
+static int ext2_readlink (struct inode * inode, char * buffer, int buflen)
+{
+	struct buffer_head * bh = NULL;
+	char * link;
+	int i, err;
+	char c;
+
+	if (!S_ISLNK(inode->i_mode)) {
+		iput (inode);
+		return -EINVAL;
+	}
+	if (buflen > inode->i_sb->s_blocksize - 1)
+		buflen = inode->i_sb->s_blocksize - 1;
+	if (inode->i_blocks) {
+		bh = ext2_bread (inode, 0, 0, &err);
+		if (!bh) {
+			iput (inode);
+			return 0;
+		}
+		link = bh->b_data;
+	}
+	else
+		link = (char *) inode->u.ext2_i.i_data;
+	i = 0;
+	while (i < buflen && (c = link[i])) {
+		i++;
+		put_fs_byte (c, buffer++);
+	}
+	iput (inode);
+	if (bh)
+		brelse (bh);
+	return i;
+}