linux-imx

/*

 * misc.c

 *

 * PURPOSE

 *  Miscellaneous routines for the OSTA-UDF(tm) filesystem.

 *

 * 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 Dave Boynton

 *  (C) 1998-2004 Ben Fennema

 *  (C) 1999-2000 Stelias Computing Inc

 *

 * HISTORY

 *

 *  04/19/99 blf  partial support for reading/writing specific EA's

 */

​

#include "udfdecl.h"

​

#include <linux/fs.h>

#include <linux/string.h>

#include <linux/crc-itu-t.h>

​

#include "udf_i.h"

#include "udf_sb.h"

​

struct buffer_head *udf_tgetblk(struct super_block *sb, udf_pblk_t block)

{

    if (UDF_QUERY_FLAG(sb, UDF_FLAG_VARCONV))

        return sb_getblk(sb, udf_fixed_to_variable(block));

    else

        return sb_getblk(sb, block);

}

​

struct buffer_head *udf_tread(struct super_block *sb, udf_pblk_t block)

{

    if (UDF_QUERY_FLAG(sb, UDF_FLAG_VARCONV))

        return sb_bread(sb, udf_fixed_to_variable(block));

    else

        return sb_bread(sb, block);

}

​

struct genericFormat *udf_add_extendedattr(struct inode *inode, uint32_t size,

                       uint32_t type, uint8_t loc)

{

    uint8_t *ea = NULL, *ad = NULL;

    int offset;

    uint16_t crclen;

    struct udf_inode_info *iinfo = UDF_I(inode);

​

    ea = iinfo->i_ext.i_data;

    if (iinfo->i_lenEAttr) {

        ad = iinfo->i_ext.i_data + iinfo->i_lenEAttr;

    } else {

        ad = ea;

        size += sizeof(struct extendedAttrHeaderDesc);

    }

​

    offset = inode->i_sb->s_blocksize - udf_file_entry_alloc_offset(inode) -

        iinfo->i_lenAlloc;

​

    /* TODO - Check for FreeEASpace */

​

    if (loc & 0x01 && offset >= size) {

        struct extendedAttrHeaderDesc *eahd;

        eahd = (struct extendedAttrHeaderDesc *)ea;

​

        if (iinfo->i_lenAlloc)

            memmove(&ad[size], ad, iinfo->i_lenAlloc);

​

        if (iinfo->i_lenEAttr) {

            /* check checksum/crc */

            if (eahd->descTag.tagIdent !=

                    cpu_to_le16(TAG_IDENT_EAHD) ||

                le32_to_cpu(eahd->descTag.tagLocation) !=

                    iinfo->i_location.logicalBlockNum)

                return NULL;

        } else {

            struct udf_sb_info *sbi = UDF_SB(inode->i_sb);

​

            size -= sizeof(struct extendedAttrHeaderDesc);

            iinfo->i_lenEAttr +=

                sizeof(struct extendedAttrHeaderDesc);

            eahd->descTag.tagIdent = cpu_to_le16(TAG_IDENT_EAHD);

            if (sbi->s_udfrev >= 0x0200)

                eahd->descTag.descVersion = cpu_to_le16(3);

            else

                eahd->descTag.descVersion = cpu_to_le16(2);