Import of Linus's Linux 1.1.68

1 files changed, 110 insertions, 0 deletions

diff --git a/fs/sysv/symlink.c b/fs/sysv/symlink.c
new file mode 100644
index 000000000..d392816bc
--- /dev/null
+++ b/fs/sysv/symlink.c
@@ -0,0 +1,110 @@
+/*
+ *  linux/fs/sysv/symlink.c
+ *
+ *  minix/symlink.c
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *
+ *  coh/symlink.c
+ *  Copyright (C) 1993  Pascal Haible, Bruno Haible
+ *
+ *  sysv/symlink.c
+ *  Copyright (C) 1993  Bruno Haible
+ *
+ *  SystemV/Coherent symlink handling code
+ */
+
+#include <asm/segment.h>
+
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <linux/sysv_fs.h>
+#include <linux/stat.h>
+
+static int sysv_readlink(struct inode *, char *, int);
+static int sysv_follow_link(struct inode *, struct inode *, int, int, struct inode **);
+
+/*
+ * symlinks can't do much...
+ */
+struct inode_operations sysv_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 */
+	sysv_readlink,		/* readlink */
+	sysv_follow_link,	/* follow_link */
+	NULL,			/* bmap */
+	NULL,			/* truncate */
+	NULL			/* permission */
+};
+
+static int sysv_follow_link(struct inode * dir, struct inode * inode,
+	int flag, int mode, struct inode ** res_inode)
+{
+	int error;
+	struct buffer_head * bh;
+
+	*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(inode);
+		iput(dir);
+		return -ELOOP;
+	}
+	if (!(bh = sysv_file_bread(inode, 0, 0))) { /* is reading 1 block enough ?? */
+		iput(inode);
+		iput(dir);
+		return -EIO;
+	}
+	iput(inode);
+	current->link_count++;
+	error = open_namei(bh->b_data,flag,mode,res_inode,dir);
+	current->link_count--;
+	brelse(bh);
+	return error;
+}
+
+static int sysv_readlink(struct inode * inode, char * buffer, int buflen)
+{
+	struct buffer_head * bh;
+	char * bh_data;
+	int i;
+	char c;
+
+	if (!S_ISLNK(inode->i_mode)) {
+		iput(inode);
+		return -EINVAL;
+	}
+	if (buflen > inode->i_sb->sv_block_size_1)
+		buflen = inode->i_sb->sv_block_size_1;
+	bh = sysv_file_bread(inode, 0, 0);
+	iput(inode);
+	if (!bh)
+		return 0;
+	bh_data = bh->b_data;
+	i = 0;
+	while (i<buflen && (c = bh_data[i])) {
+		i++;
+		put_fs_byte(c,buffer++);
+	}
+	brelse(bh);
+	return i;
+}