release/src-rt-6.x.4708/linux/linux-2.6.36/fs/affs/symlink.c

   1 /*
   2  *  linux/fs/affs/symlink.c
   3  *
   4  *  1995  Hans-Joachim Widmaier - Modified for affs.
   5  *
   6  *  Copyright (C) 1991, 1992  Linus Torvalds
   7  *
   8  *  affs symlink handling code
   9  */
  10
  11 #include "affs.h"
  12
  13 static int affs_symlink_readpage(struct file *file, struct page *page)
  14 {
  15         struct buffer_head *bh;
  16         struct inode *inode = page->mapping->host;
  17         char *link = kmap(page);
  18         struct slink_front *lf;
  19         int err;
  20         int                      i, j;
  21         char                     c;
  22         char                     lc;
  23
  24         pr_debug("AFFS: follow_link(ino=%lu)\n",inode->i_ino);
  25
  26         err = -EIO;
  27         bh = affs_bread(inode->i_sb, inode->i_ino);
  28         if (!bh)
  29                 goto fail;
  30         i  = 0;
  31         j  = 0;
  32         lf = (struct slink_front *)bh->b_data;
  33         lc = 0;
  34
  35         if (strchr(lf->symname,':')) {  /* Handle assign or volume name */
  36                 struct affs_sb_info *sbi = AFFS_SB(inode->i_sb);
  37                 char *pf;
  38                 spin_lock(&sbi->symlink_lock);
  39                 pf = sbi->s_prefix ? sbi->s_prefix : "/";
  40                 while (i < 1023 && (c = pf[i]))
  41                         link[i++] = c;
  42                 spin_unlock(&sbi->symlink_lock);
  43                 while (i < 1023 && lf->symname[j] != ':')
  44                         link[i++] = lf->symname[j++];
  45                 if (i < 1023)
  46                         link[i++] = '/';
  47                 j++;
  48                 lc = '/';
  49         }
  50         while (i < 1023 && (c = lf->symname[j])) {
  51                 if (c == '/' && lc == '/' && i < 1020) {        /* parent dir */
  52                         link[i++] = '.';
  53                         link[i++] = '.';
  54                 }
  55                 link[i++] = c;
  56                 lc = c;
  57                 j++;
  58         }
  59         link[i] = '\0';
  60         affs_brelse(bh);
  61         SetPageUptodate(page);
  62         kunmap(page);
  63         unlock_page(page);
  64         return 0;
  65 fail:
  66         SetPageError(page);
  67         kunmap(page);
  68         unlock_page(page);
  69         return err;
  70 }
  71
  72 const struct address_space_operations affs_symlink_aops = {
  73         .readpage       = affs_symlink_readpage,
  74 };
  75
  76 const struct inode_operations affs_symlink_inode_operations = {
  77         .readlink       = generic_readlink,
  78         .follow_link    = page_follow_link_light,
  79         .put_link       = page_put_link,
  80         .setattr        = affs_notify_change,
  81 };