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-rw-r--r--fs/sysv/symlink.c110
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;
+}