fs/isofs/symlink.c

/* */
This source file includes following definitions.
isofs_follow_link
isofs_readlink
   1 /*
   2  *  linux/fs/isofs/symlink.c
   3  *
   4  *  (C) 1992  Eric Youngdale Modified for ISO9660 filesystem.
   5  *
   6  *  Copyright (C) 1991, 1992  Linus Torvalds
   7  *
   8  *  isofs symlink handling code.  This is only used with the Rock Ridge
   9  *  extensions to iso9660
  10  */
  11 
  12 #include <asm/segment.h>
  13 
  14 #include <linux/errno.h>
  15 #include <linux/sched.h>
  16 #include <linux/fs.h>
  17 #include <linux/iso_fs.h>
  18 #include <linux/stat.h>
  19 
  20 static int isofs_readlink(struct inode *, char *, int);
  21 static int isofs_follow_link(struct inode *, struct inode *, int, int, struct inode **);
  22 
  23 /*
  24  * symlinks can't do much...
  25  */
  26 struct inode_operations isofs_symlink_inode_operations = {
  27         NULL,                   /* no file-operations */
  28         NULL,                   /* create */
  29         NULL,                   /* lookup */
  30         NULL,                   /* link */
  31         NULL,                   /* unlink */
  32         NULL,                   /* symlink */
  33         NULL,                   /* mkdir */
  34         NULL,                   /* rmdir */
  35         NULL,                   /* mknod */
  36         NULL,                   /* rename */
  37         isofs_readlink,         /* readlink */
  38         isofs_follow_link,      /* follow_link */
  39         NULL,                   /* bmap */
  40         NULL,                   /* truncate */
  41         NULL                    /* permission */
  42 };
  43 
  44 static int isofs_follow_link(struct inode * dir, struct inode * inode,
     /*  */
  45         int flag, int mode, struct inode ** res_inode)
  46 {
  47         int error;
  48         char * pnt;
  49 
  50         if (!dir) {
  51                 dir = current->root;
  52                 dir->i_count++;
  53         }
  54         if (!inode) {
  55                 iput(dir);
  56                 *res_inode = NULL;
  57                 return -ENOENT;
  58         }
  59         if (!S_ISLNK(inode->i_mode)) {
  60                 iput(dir);
  61                 *res_inode = inode;
  62                 return 0;
  63         }
  64         if ((current->link_count > 5) ||
  65            !(pnt = get_rock_ridge_symlink(inode))) {
  66                 iput(dir);
  67                 iput(inode);
  68                 *res_inode = NULL;
  69                 return -ELOOP;
  70         }
  71         iput(inode);
  72         current->link_count++;
  73         error = open_namei(pnt,flag,mode,res_inode,dir);
  74         current->link_count--;
  75         kfree(pnt);
  76         return error;
  77 }
  78 
  79 static int isofs_readlink(struct inode * inode, char * buffer, int buflen)
     /*  */
  80 {
  81         char * pnt;
  82         int i;
  83         char c;
  84 
  85         if (!S_ISLNK(inode->i_mode)) {
  86                 iput(inode);
  87                 return -EINVAL;
  88         }
  89 
  90         if (buflen > 1023)
  91                 buflen = 1023;
  92         pnt = get_rock_ridge_symlink(inode);
  93 
  94         iput(inode);
  95         if (!pnt)
  96                 return 0;
  97         i = 0;
  98 
  99         while (i<buflen && (c = pnt[i])) {
 100                 i++;
 101                 put_fs_byte(c,buffer++);
 102         }
 103         kfree(pnt);
 104         return i;
 105 }
/* */
root/fs/isofs/symlink.c

DEFINITIONS
