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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) 1998-2001 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) == ICBTAG_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,

};