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 <linux/errno.h>
  13 #include <linux/sched.h>
  14 #include <linux/fs.h>
  15 #include <linux/iso_fs.h>
  16 #include <linux/stat.h>
  17 #include <linux/malloc.h>
  18 
  19 #include <asm/segment.h>
  20 
  21 static int isofs_readlink(struct inode *, char *, int);
  22 static int isofs_follow_link(struct inode *, struct inode *, int, int, struct inode **);
  23 
  24 /*
  25  * symlinks can't do much...
  26  */
  27 struct inode_operations isofs_symlink_inode_operations = {
  28         NULL,                   /* no file-operations */
  29         NULL,                   /* create */
  30         NULL,                   /* lookup */
  31         NULL,                   /* link */
  32         NULL,                   /* unlink */
  33         NULL,                   /* symlink */
  34         NULL,                   /* mkdir */
  35         NULL,                   /* rmdir */
  36         NULL,                   /* mknod */
  37         NULL,                   /* rename */
  38         isofs_readlink,         /* readlink */
  39         isofs_follow_link,      /* follow_link */
  40         NULL,                   /* bmap */
  41         NULL,                   /* truncate */
  42         NULL                    /* permission */
  43 };
  44 
  45 static int isofs_follow_link(struct inode * dir, struct inode * inode,
     /*  */
  46         int flag, int mode, struct inode ** res_inode)
  47 {
  48         int error;
  49         char * pnt;
  50 
  51         if (!dir) {
  52                 dir = current->fs->root;
  53                 dir->i_count++;
  54         }
  55         if (!inode) {
  56                 iput(dir);
  57                 *res_inode = NULL;
  58                 return -ENOENT;
  59         }
  60         if (!S_ISLNK(inode->i_mode)) {
  61                 iput(dir);
  62                 *res_inode = inode;
  63                 return 0;
  64         }
  65         if ((current->link_count > 5) ||
  66            !(pnt = get_rock_ridge_symlink(inode))) {
  67                 iput(dir);
  68                 iput(inode);
  69                 *res_inode = NULL;
  70                 return -ELOOP;
  71         }
  72         iput(inode);
  73         current->link_count++;
  74         error = open_namei(pnt,flag,mode,res_inode,dir);
  75         current->link_count--;
  76         kfree(pnt);
  77         return error;
  78 }
  79 
  80 static int isofs_readlink(struct inode * inode, char * buffer, int buflen)
     /*  */
  81 {
  82         char * pnt;
  83         int i;
  84         char c;
  85 
  86         if (!S_ISLNK(inode->i_mode)) {
  87                 iput(inode);
  88                 return -EINVAL;
  89         }
  90 
  91         if (buflen > 1023)
  92                 buflen = 1023;
  93         pnt = get_rock_ridge_symlink(inode);
  94 
  95         iput(inode);
  96         if (!pnt)
  97                 return 0;
  98         i = 0;
  99 
 100         while (i<buflen && (c = pnt[i])) {
 101                 i++;
 102                 put_user(c,buffer++);
 103         }
 104         kfree(pnt);
 105         return i;
 106 }
/* */
root/fs/isofs/symlink.c

DEFINITIONS
