kernel/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                      i, j;
  20         char                     c;
  21         char                     lc;
  22
  23         pr_debug("follow_link(ino=%lu)\n", inode->i_ino);
  24
  25         bh = affs_bread(inode->i_sb, inode->i_ino);
  26         if (!bh)
  27                 goto fail;
  28         i  = 0;
  29         j  = 0;
  30         lf = (struct slink_front *)bh->b_data;
  31         lc = 0;
  32
  33         if (strchr(lf->symname,':')) {  /* Handle assign or volume name */
  34                 struct affs_sb_info *sbi = AFFS_SB(inode->i_sb);
  35                 char *pf;
  36                 spin_lock(&sbi->symlink_lock);
  37                 pf = sbi->s_prefix ? sbi->s_prefix : "/";
  38                 while (i < 1023 && (c = pf[i]))
  39                         link[i++] = c;
  40                 spin_unlock(&sbi->symlink_lock);
  41                 while (i < 1023 && lf->symname[j] != ':')
  42                         link[i++] = lf->symname[j++];
  43                 if (i < 1023)
  44                         link[i++] = '/';
  45                 j++;
  46                 lc = '/';
  47         }
  48         while (i < 1023 && (c = lf->symname[j])) {
  49                 if (c == '/' && lc == '/' && i < 1020) {        /* parent dir */
  50                         link[i++] = '.';
  51                         link[i++] = '.';
  52                 }
  53                 link[i++] = c;
  54                 lc = c;
  55                 j++;
  56         }
  57         link[i] = '\0';
  58         affs_brelse(bh);
  59         SetPageUptodate(page);
  60         kunmap(page);
  61         unlock_page(page);
  62         return 0;
  63 fail:
  64         SetPageError(page);
  65         kunmap(page);
  66         unlock_page(page);
  67         return -EIO;
  68 }
  69
  70 const struct address_space_operations affs_symlink_aops = {
  71         .readpage       = affs_symlink_readpage,
  72 };
  73
  74 const struct inode_operations affs_symlink_inode_operations = {
  75         .readlink       = generic_readlink,
  76         .follow_link    = page_follow_link_light,
  77         .put_link       = page_put_link,
  78         .setattr        = affs_notify_change,
  79 };