| /* |
| * linux/fs/isofs/symlink.c |
| * |
| * (C) 1992 Eric Youngdale Modified for ISO9660 filesystem. |
| * |
| * Copyright (C) 1991, 1992 Linus Torvalds |
| * |
| * isofs symlink handling code. This is only used with the Rock Ridge |
| * extensions to iso9660 |
| */ |
| |
| #include <asm/segment.h> |
| |
| #include <linux/errno.h> |
| #include <linux/sched.h> |
| #include <linux/fs.h> |
| #include <linux/iso_fs.h> |
| #include <linux/stat.h> |
| #include <linux/malloc.h> |
| |
| static int isofs_readlink(struct inode *, char *, int); |
| static int isofs_follow_link(struct inode *, struct inode *, int, int, struct inode **); |
| |
| /* |
| * symlinks can't do much... |
| */ |
| struct inode_operations isofs_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 */ |
| isofs_readlink, /* readlink */ |
| isofs_follow_link, /* follow_link */ |
| NULL, /* bmap */ |
| NULL, /* truncate */ |
| NULL /* permission */ |
| }; |
| |
| static int isofs_follow_link(struct inode * dir, struct inode * inode, |
| int flag, int mode, struct inode ** res_inode) |
| { |
| int error; |
| char * pnt; |
| |
| if (!dir) { |
| dir = current->root; |
| dir->i_count++; |
| } |
| if (!inode) { |
| iput(dir); |
| *res_inode = NULL; |
| return -ENOENT; |
| } |
| if (!S_ISLNK(inode->i_mode)) { |
| iput(dir); |
| *res_inode = inode; |
| return 0; |
| } |
| if ((current->link_count > 5) || |
| !(pnt = get_rock_ridge_symlink(inode))) { |
| iput(dir); |
| iput(inode); |
| *res_inode = NULL; |
| return -ELOOP; |
| } |
| iput(inode); |
| current->link_count++; |
| error = open_namei(pnt,flag,mode,res_inode,dir); |
| current->link_count--; |
| kfree(pnt); |
| return error; |
| } |
| |
| static int isofs_readlink(struct inode * inode, char * buffer, int buflen) |
| { |
| char * pnt; |
| int i; |
| char c; |
| |
| if (!S_ISLNK(inode->i_mode)) { |
| iput(inode); |
| return -EINVAL; |
| } |
| |
| if (buflen > 1023) |
| buflen = 1023; |
| pnt = get_rock_ridge_symlink(inode); |
| |
| iput(inode); |
| if (!pnt) |
| return 0; |
| i = 0; |
| |
| while (i<buflen && (c = pnt[i])) { |
| i++; |
| put_fs_byte(c,buffer++); |
| } |
| kfree(pnt); |
| return i; |
| } |