fs/affs/symlink.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  linux/fs/affs/symlink.c
   4  *
   5  *  1995  Hans-Joachim Widmaier - Modified for affs.
   6  *
   7  *  Copyright (C) 1991, 1992  Linus Torvalds
   8  *
   9  *  affs symlink handling code
  10  */
  11
  12 #include "affs.h"
  13
  14 static int affs_symlink_read_folio(struct file *file, struct folio *folio)
  15 {
  16         struct page *page = &folio->page;
  17         struct buffer_head *bh;
  18         struct inode *inode = page->mapping->host;
  19         char *link = page_address(page);
  20         struct slink_front *lf;
  21         int                      i, j;
  22         char                     c;
  23         char                     lc;
  24
  25         pr_debug("get_link(ino=%lu)\n", inode->i_ino);
  26
  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         unlock_page(page);
  63         return 0;
  64 fail:
  65         SetPageError(page);
  66         unlock_page(page);
  67         return -EIO;
  68 }
  69
  70 const struct address_space_operations affs_symlink_aops = {
  71         .read_folio     = affs_symlink_read_folio,
  72 };
  73
  74 const struct inode_operations affs_symlink_inode_operations = {
  75         .get_link       = page_get_link,
  76         .setattr        = affs_notify_change,
  77 };