Viewing file:  symlink.c (2.52 KB) -rw-r--r--
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/*
* symlink.c
*
* PURPOSE
* Symlink handling routines for the OSTA-UDF(tm) filesystem.
*
* CONTACTS
* E-mail regarding any portion of the Linux UDF file system should be
* directed to the development team mailing list (run by majordomo):
* linux_udf@hpesjro.fc.hp.com
*
* COPYRIGHT
* This file is distributed under the terms of the GNU General Public
* License (GPL). Copies of the GPL can be obtained from:
* ftp://prep.ai.mit.edu/pub/gnu/GPL
* Each contributing author retains all rights to their own work.
*
* (C) 1998-2000 Ben Fennema
* (C) 1999 Stelias Computing Inc
*
* HISTORY
*
* 04/16/99 blf Created.
*
*/
#include "udfdecl.h"
#include <asm/uaccess.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/udf_fs.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/stat.h>
#include <linux/slab.h>
#include <linux/pagemap.h>
#include <linux/smp_lock.h>
#include "udf_i.h"
static void udf_pc_to_char(char *from, int fromlen, char *to)
{
struct PathComponent *pc;
int elen = 0;
char *p = to;
while (elen < fromlen)
{
pc = (struct PathComponent *)(from + elen);
switch (pc->componentType)
{
case 1:
if (pc->lengthComponentIdent == 0)
{
p = to;
*p++ = '/';
}
break;
case 3:
memcpy(p, "../", 3);
p += 3;
break;
case 4:
memcpy(p, "./", 2);
p += 2;
/* that would be . - just ignore */
break;
case 5:
memcpy(p, pc->componentIdent, pc->lengthComponentIdent);
p += pc->lengthComponentIdent;
*p++ = '/';
}
elen += sizeof(struct PathComponent) + pc->lengthComponentIdent;
}
if (p > to+1)
p[-1] = '\0';
else
p[0] = '\0';
}
static int udf_symlink_filler(struct file *file, struct page *page)
{
struct inode *inode = page->mapping->host;
struct buffer_head *bh = NULL;
char *symlink;
int err = -EIO;
char *p = kmap(page);
lock_kernel();
if (UDF_I_ALLOCTYPE(inode) == ICB_FLAG_AD_IN_ICB)
{
bh = udf_tread(inode->i_sb, inode->i_ino);
if (!bh)
goto out;
symlink = bh->b_data + udf_file_entry_alloc_offset(inode);
}
else
{
bh = sb_bread(inode->i_sb, udf_block_map(inode, 0));
if (!bh)
goto out;
symlink = bh->b_data;
}
udf_pc_to_char(symlink, inode->i_size, p);
udf_release_data(bh);
unlock_kernel();
SetPageUptodate(page);
kunmap(page);
UnlockPage(page);
return 0;
out:
unlock_kernel();
SetPageError(page);
kunmap(page);
UnlockPage(page);
return err;
}
/*
* symlinks can't do much...
*/
struct address_space_operations udf_symlink_aops = {
readpage: udf_symlink_filler,
};
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