inode.c

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/*
 * inode.c
 *
 * PURPOSE
 *  Inode handling 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
 *
 *  10/04/98 dgb  Added rudimentary directory functions
 *  10/07/98      Fully working udf_block_map! It works!
 *  11/25/98      bmap altered to better support extents
 *  12/06/98 blf  partition support in udf_iget, udf_block_map
 *                and udf_read_inode
 *  12/12/98      rewrote udf_block_map to handle next extents and descs across
 *                block boundaries (which is not actually allowed)
 *  12/20/98      added support for strategy 4096
 *  03/07/99      rewrote udf_block_map (again)
 *                New funcs, inode_bmap, udf_next_aext
 *  04/19/99      Support for writing device EA's for major/minor #
 */

#include "udfdecl.h"
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/pagemap.h>
#include <linux/buffer_head.h>
#include <linux/writeback.h>
#include <linux/slab.h>
#include <linux/crc-itu-t.h>
#include <linux/mpage.h>

#include "udf_i.h"
#include "udf_sb.h"

MODULE_AUTHOR("Ben Fennema");
MODULE_DESCRIPTION("Universal Disk Format Filesystem");
MODULE_LICENSE("GPL");

#define EXTENT_MERGE_SIZE 5

static umode_t udf_convert_permissions(struct fileEntry *);
static int udf_update_inode(struct inode *, int);
static void udf_fill_inode(struct inode *, struct buffer_head *);
static int udf_sync_inode(struct inode *inode);
static int udf_alloc_i_data(struct inode *inode, size_t size);
static sector_t inode_getblk(struct inode *, sector_t, int *, int *);
static int8_t udf_insert_aext(struct inode *, struct extent_position,
                  struct kernel_lb_addr, uint32_t);
static void udf_split_extents(struct inode *, int *, int, int,
                  struct kernel_long_ad[EXTENT_MERGE_SIZE], int *);
static void udf_prealloc_extents(struct inode *, int, int,
                 struct kernel_long_ad[EXTENT_MERGE_SIZE], int *);
static void udf_merge_extents(struct inode *,
                  struct kernel_long_ad[EXTENT_MERGE_SIZE], int *);
static void udf_update_extents(struct inode *,
                   struct kernel_long_ad[EXTENT_MERGE_SIZE], int, int,
                   struct extent_position *);
static int udf_get_block(struct inode *, sector_t, struct buffer_head *, int);


void udf_evict_inode(struct inode *inode)
{
    struct udf_inode_info *iinfo = UDF_I(inode);
    int want_delete = 0;

    if (!inode->i_nlink && !is_bad_inode(inode)) {
        want_delete = 1;
        udf_setsize(inode, 0);
        udf_update_inode(inode, IS_SYNC(inode));
    } else
        truncate_inode_pages(&inode->i_data, 0);
    invalidate_inode_buffers(inode);
    clear_inode(inode);
    if (iinfo->i_alloc_type != ICBTAG_FLAG_AD_IN_ICB &&
        inode->i_size != iinfo->i_lenExtents) {
        udf_warn(inode->i_sb, "Inode %lu (mode %o) has inode size %llu different from extent length %llu. Filesystem need not be standards compliant.\n",
             inode->i_ino, inode->i_mode,
             (unsigned long long)inode->i_size,
             (unsigned long long)iinfo->i_lenExtents);
    }
    kfree(iinfo->i_ext.i_data);
    iinfo->i_ext.i_data = NULL;
    if (want_delete) {
        udf_free_inode(inode);
    }
}

static void udf_write_failed(struct address_space *mapping, loff_t to)
{
    struct inode *inode = mapping->host;
    struct udf_inode_info *iinfo = UDF_I(inode);
    loff_t isize = inode->i_size;

    if (to > isize) {
        truncate_pagecache(inode, to, isize);
        if (iinfo->i_alloc_type != ICBTAG_FLAG_AD_IN_ICB) {
            down_write(&iinfo->i_data_sem);
            udf_truncate_extents(inode);
            up_write(&iinfo->i_data_sem);
        }
    }
}

static int udf_writepage(struct page *page, struct writeback_control *wbc)
{
    return block_write_full_page(page, udf_get_block, wbc);
}

static int udf_writepages(struct address_space *mapping,
            struct writeback_control *wbc)
{
    return mpage_writepages(mapping, wbc, udf_get_block);
}

static int udf_readpage(struct file *file, struct page *page)
{
    return mpage_readpage(page, udf_get_block);
}

static int udf_readpages(struct file *file, struct address_space *mapping,
            struct list_head *pages, unsigned nr_pages)
{
    return mpage_readpages(mapping, pages, nr_pages, udf_get_block);
}

static int udf_write_begin(struct file *file, struct address_space *mapping,
            loff_t pos, unsigned len, unsigned flags,
            struct page **pagep, void **fsdata)
{
    int ret;

    ret = block_write_begin(mapping, pos, len, flags, pagep, udf_get_block);
    if (unlikely(ret))
        udf_write_failed(mapping, pos + len);
    return ret;
}

static ssize_t udf_direct_IO(int rw, struct kiocb *iocb,
                 const struct iovec *iov,
                 loff_t offset, unsigned long nr_segs)
{
    struct file *file = iocb->ki_filp;
    struct address_space *mapping = file->f_mapping;
    struct inode *inode = mapping->host;
    ssize_t ret;

    ret = blockdev_direct_IO(rw, iocb, inode, iov, offset, nr_segs,
                  udf_get_block);
    if (unlikely(ret < 0 && (rw & WRITE)))
        udf_write_failed(mapping, offset + iov_length(iov, nr_segs));
    return ret;
}

static sector_t udf_bmap(struct address_space *mapping, sector_t block)
{
    return generic_block_bmap(mapping, block, udf_get_block);
}

const struct address_space_operations udf_aops = {
    .readpage   = udf_readpage,
    .readpages  = udf_readpages,
    .writepage  = udf_writepage,
    .writepages = udf_writepages,
    .write_begin    = udf_write_begin,
    .write_end  = generic_write_end,
    .direct_IO  = udf_direct_IO,
    .bmap       = udf_bmap,
};

/*
 * Expand file stored in ICB to a normal one-block-file
 *
 * This function requires i_data_sem for writing and releases it.
 * This function requires i_mutex held
 */
int udf_expand_file_adinicb(struct inode *inode)
{
    struct page *page;
    char *kaddr;
    struct udf_inode_info *iinfo = UDF_I(inode);
    int err;
    struct writeback_control udf_wbc = {
        .sync_mode = WB_SYNC_NONE,
        .nr_to_write = 1,
    };

    if (!iinfo->i_lenAlloc) {
        if (UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_USE_SHORT_AD))
            iinfo->i_alloc_type = ICBTAG_FLAG_AD_SHORT;
        else
            iinfo->i_alloc_type = ICBTAG_FLAG_AD_LONG;
        /* from now on we have normal address_space methods */
        inode->i_data.a_ops = &udf_aops;
        up_write(&iinfo->i_data_sem);
        mark_inode_dirty(inode);
        return 0;
    }
    /*
     * Release i_data_sem so that we can lock a page - page lock ranks
     * above i_data_sem. i_mutex still protects us against file changes.
     */
    up_write(&iinfo->i_data_sem);

    page = find_or_create_page(inode->i_mapping, 0, GFP_NOFS);
    if (!page)
        return -ENOMEM;

    if (!PageUptodate(page)) {
        kaddr = kmap(page);
        memset(kaddr + iinfo->i_lenAlloc, 0x00,
               PAGE_CACHE_SIZE - iinfo->i_lenAlloc);
        memcpy(kaddr, iinfo->i_ext.i_data + iinfo->i_lenEAttr,
            iinfo->i_lenAlloc);
        flush_dcache_page(page);
        SetPageUptodate(page);
        kunmap(page);
    }
    down_write(&iinfo->i_data_sem);
    memset(iinfo->i_ext.i_data + iinfo->i_lenEAttr, 0x00,
           iinfo->i_lenAlloc);
    iinfo->i_lenAlloc = 0;
    if (UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_USE_SHORT_AD))
        iinfo->i_alloc_type = ICBTAG_FLAG_AD_SHORT;
    else
        iinfo->i_alloc_type = ICBTAG_FLAG_AD_LONG;
    /* from now on we have normal address_space methods */
    inode->i_data.a_ops = &udf_aops;
    up_write(&iinfo->i_data_sem);
    err = inode->i_data.a_ops->writepage(page, &udf_wbc);
    if (err) {
        /* Restore everything back so that we don't lose data... */
        lock_page(page);
        kaddr = kmap(page);
        down_write(&iinfo->i_data_sem);
        memcpy(iinfo->i_ext.i_data + iinfo->i_lenEAttr, kaddr,
               inode->i_size);
        kunmap(page);
        unlock_page(page);
        iinfo->i_alloc_type = ICBTAG_FLAG_AD_IN_ICB;
        inode->i_data.a_ops = &udf_adinicb_aops;
        up_write(&iinfo->i_data_sem);
    }
    page_cache_release(page);
    mark_inode_dirty(inode);

    return err;
}

struct buffer_head *udf_expand_dir_adinicb(struct inode *inode, int *block,
                       int *err)
{
    int newblock;
    struct buffer_head *dbh = NULL;
    struct kernel_lb_addr eloc;
    uint8_t alloctype;
    struct extent_position epos;

    struct udf_fileident_bh sfibh, dfibh;
    loff_t f_pos = udf_ext0_offset(inode);
    int size = udf_ext0_offset(inode) + inode->i_size;
    struct fileIdentDesc cfi, *sfi, *dfi;
    struct udf_inode_info *iinfo = UDF_I(inode);

    if (UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_USE_SHORT_AD))
        alloctype = ICBTAG_FLAG_AD_SHORT;
    else
        alloctype = ICBTAG_FLAG_AD_LONG;

    if (!inode->i_size) {
        iinfo->i_alloc_type = alloctype;
        mark_inode_dirty(inode);
        return NULL;
    }

    /* alloc block, and copy data to it */
    *block = udf_new_block(inode->i_sb, inode,
                   iinfo->i_location.partitionReferenceNum,
                   iinfo->i_location.logicalBlockNum, err);
    if (!(*block))
        return NULL;
    newblock = udf_get_pblock(inode->i_sb, *block,
                  iinfo->i_location.partitionReferenceNum,
                0);
    if (!newblock)
        return NULL;
    dbh = udf_tgetblk(inode->i_sb, newblock);
    if (!dbh)
        return NULL;
    lock_buffer(dbh);
    memset(dbh->b_data, 0x00, inode->i_sb->s_blocksize);
    set_buffer_uptodate(dbh);
    unlock_buffer(dbh);
    mark_buffer_dirty_inode(dbh, inode);

    sfibh.soffset = sfibh.eoffset =
            f_pos & (inode->i_sb->s_blocksize - 1);
    sfibh.sbh = sfibh.ebh = NULL;
    dfibh.soffset = dfibh.eoffset = 0;
    dfibh.sbh = dfibh.ebh = dbh;
    while (f_pos < size) {
        iinfo->i_alloc_type = ICBTAG_FLAG_AD_IN_ICB;
        sfi = udf_fileident_read(inode, &f_pos, &sfibh, &cfi, NULL,
                     NULL, NULL, NULL);
        if (!sfi) {
            brelse(dbh);
            return NULL;
        }
        iinfo->i_alloc_type = alloctype;
        sfi->descTag.tagLocation = cpu_to_le32(*block);
        dfibh.soffset = dfibh.eoffset;
        dfibh.eoffset += (sfibh.eoffset - sfibh.soffset);
        dfi = (struct fileIdentDesc *)(dbh->b_data + dfibh.soffset);
        if (udf_write_fi(inode, sfi, dfi, &dfibh, sfi->impUse,
                 sfi->fileIdent +
                    le16_to_cpu(sfi->lengthOfImpUse))) {
            iinfo->i_alloc_type = ICBTAG_FLAG_AD_IN_ICB;
            brelse(dbh);
            return NULL;
        }
    }
    mark_buffer_dirty_inode(dbh, inode);

    memset(iinfo->i_ext.i_data + iinfo->i_lenEAttr, 0,
        iinfo->i_lenAlloc);
    iinfo->i_lenAlloc = 0;
    eloc.logicalBlockNum = *block;
    eloc.partitionReferenceNum =
                iinfo->i_location.partitionReferenceNum;
    iinfo->i_lenExtents = inode->i_size;
    epos.bh = NULL;
    epos.block = iinfo->i_location;
    epos.offset = udf_file_entry_alloc_offset(inode);
    udf_add_aext(inode, &epos, &eloc, inode->i_size, 0);
    /* UniqueID stuff */

    brelse(epos.bh);
    mark_inode_dirty(inode);
    return dbh;
}

static int udf_get_block(struct inode *inode, sector_t block,
             struct buffer_head *bh_result, int create)
{
    int err, new;
    sector_t phys = 0;
    struct udf_inode_info *iinfo;

    if (!create) {
        phys = udf_block_map(inode, block);
        if (phys)
            map_bh(bh_result, inode->i_sb, phys);
        return 0;
    }

    err = -EIO;
    new = 0;
    iinfo = UDF_I(inode);

    down_write(&iinfo->i_data_sem);
    if (block == iinfo->i_next_alloc_block + 1) {
        iinfo->i_next_alloc_block++;
        iinfo->i_next_alloc_goal++;
    }


    phys = inode_getblk(inode, block, &err, &new);
    if (!phys)
        goto abort;

    if (new)
        set_buffer_new(bh_result);
    map_bh(bh_result, inode->i_sb, phys);

abort:
    up_write(&iinfo->i_data_sem);
    return err;
}

static struct buffer_head *udf_getblk(struct inode *inode, long block,
                      int create, int *err)
{
    struct buffer_head *bh;
    struct buffer_head dummy;

    dummy.b_state = 0;
    dummy.b_blocknr = -1000;
    *err = udf_get_block(inode, block, &dummy, create);
    if (!*err && buffer_mapped(&dummy)) {
        bh = sb_getblk(inode->i_sb, dummy.b_blocknr);
        if (buffer_new(&dummy)) {
            lock_buffer(bh);
            memset(bh->b_data, 0x00, inode->i_sb->s_blocksize);
            set_buffer_uptodate(bh);
            unlock_buffer(bh);
            mark_buffer_dirty_inode(bh, inode);
        }
        return bh;
    }

    return NULL;
}

/* Extend the file by 'blocks' blocks, return the number of extents added */
static int udf_do_extend_file(struct inode *inode,
                  struct extent_position *last_pos,
                  struct kernel_long_ad *last_ext,
                  sector_t blocks)
{
    sector_t add;
    int count = 0, fake = !(last_ext->extLength & UDF_EXTENT_LENGTH_MASK);
    struct super_block *sb = inode->i_sb;
    struct kernel_lb_addr prealloc_loc = {};
    int prealloc_len = 0;
    struct udf_inode_info *iinfo;
    int err;

    /* The previous extent is fake and we should not extend by anything
     * - there's nothing to do... */
    if (!blocks && fake)
        return 0;

    iinfo = UDF_I(inode);
    /* Round the last extent up to a multiple of block size */
    if (last_ext->extLength & (sb->s_blocksize - 1)) {
        last_ext->extLength =
            (last_ext->extLength & UDF_EXTENT_FLAG_MASK) |
            (((last_ext->extLength & UDF_EXTENT_LENGTH_MASK) +
              sb->s_blocksize - 1) & ~(sb->s_blocksize - 1));
        iinfo->i_lenExtents =
            (iinfo->i_lenExtents + sb->s_blocksize - 1) &
            ~(sb->s_blocksize - 1);
    }

    /* Last extent are just preallocated blocks? */
    if ((last_ext->extLength & UDF_EXTENT_FLAG_MASK) ==
                        EXT_NOT_RECORDED_ALLOCATED) {
        /* Save the extent so that we can reattach it to the end */
        prealloc_loc = last_ext->extLocation;
        prealloc_len = last_ext->extLength;
        /* Mark the extent as a hole */
        last_ext->extLength = EXT_NOT_RECORDED_NOT_ALLOCATED |
            (last_ext->extLength & UDF_EXTENT_LENGTH_MASK);
        last_ext->extLocation.logicalBlockNum = 0;
        last_ext->extLocation.partitionReferenceNum = 0;
    }

    /* Can we merge with the previous extent? */
    if ((last_ext->extLength & UDF_EXTENT_FLAG_MASK) ==
                    EXT_NOT_RECORDED_NOT_ALLOCATED) {
        add = ((1 << 30) - sb->s_blocksize -
            (last_ext->extLength & UDF_EXTENT_LENGTH_MASK)) >>
            sb->s_blocksize_bits;
        if (add > blocks)
            add = blocks;
        blocks -= add;
        last_ext->extLength += add << sb->s_blocksize_bits;
    }

    if (fake) {
        udf_add_aext(inode, last_pos, &last_ext->extLocation,
                 last_ext->extLength, 1);
        count++;
    } else
        udf_write_aext(inode, last_pos, &last_ext->extLocation,
                last_ext->extLength, 1);

    /* Managed to do everything necessary? */
    if (!blocks)
        goto out;

    /* All further extents will be NOT_RECORDED_NOT_ALLOCATED */
    last_ext->extLocation.logicalBlockNum = 0;
    last_ext->extLocation.partitionReferenceNum = 0;
    add = (1 << (30-sb->s_blocksize_bits)) - 1;
    last_ext->extLength = EXT_NOT_RECORDED_NOT_ALLOCATED |
                (add << sb->s_blocksize_bits);

    /* Create enough extents to cover the whole hole */
    while (blocks > add) {
        blocks -= add;
        err = udf_add_aext(inode, last_pos, &last_ext->extLocation,
                   last_ext->extLength, 1);
        if (err)
            return err;
        count++;
    }
    if (blocks) {
        last_ext->extLength = EXT_NOT_RECORDED_NOT_ALLOCATED |
            (blocks << sb->s_blocksize_bits);
        err = udf_add_aext(inode, last_pos, &last_ext->extLocation,
                   last_ext->extLength, 1);
        if (err)
            return err;
        count++;
    }

out:
    /* Do we have some preallocated blocks saved? */
    if (prealloc_len) {
        err = udf_add_aext(inode, last_pos, &prealloc_loc,
                   prealloc_len, 1);
        if (err)
            return err;
        last_ext->extLocation = prealloc_loc;
        last_ext->extLength = prealloc_len;
        count++;
    }

    /* last_pos should point to the last written extent... */
    if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
        last_pos->offset -= sizeof(struct short_ad);
    else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
        last_pos->offset -= sizeof(struct long_ad);
    else
        return -EIO;

    return count;
}

static int udf_extend_file(struct inode *inode, loff_t newsize)
{

    struct extent_position epos;
    struct kernel_lb_addr eloc;
    uint32_t elen;
    int8_t etype;
    struct super_block *sb = inode->i_sb;
    sector_t first_block = newsize >> sb->s_blocksize_bits, offset;
    int adsize;
    struct udf_inode_info *iinfo = UDF_I(inode);
    struct kernel_long_ad extent;
    int err;

    if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
        adsize = sizeof(struct short_ad);
    else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
        adsize = sizeof(struct long_ad);
    else
        BUG();

    etype = inode_bmap(inode, first_block, &epos, &eloc, &elen, &offset);

    /* File has extent covering the new size (could happen when extending
     * inside a block)? */
    if (etype != -1)
        return 0;
    if (newsize & (sb->s_blocksize - 1))
        offset++;
    /* Extended file just to the boundary of the last file block? */
    if (offset == 0)
        return 0;

    /* Truncate is extending the file by 'offset' blocks */
    if ((!epos.bh && epos.offset == udf_file_entry_alloc_offset(inode)) ||
        (epos.bh && epos.offset == sizeof(struct allocExtDesc))) {
        /* File has no extents at all or has empty last
         * indirect extent! Create a fake extent... */
        extent.extLocation.logicalBlockNum = 0;
        extent.extLocation.partitionReferenceNum = 0;
        extent.extLength = EXT_NOT_RECORDED_NOT_ALLOCATED;
    } else {
        epos.offset -= adsize;
        etype = udf_next_aext(inode, &epos, &extent.extLocation,
                      &extent.extLength, 0);
        extent.extLength |= etype << 30;
    }
    err = udf_do_extend_file(inode, &epos, &extent, offset);
    if (err < 0)
        goto out;
    err = 0;
    iinfo->i_lenExtents = newsize;
out:
    brelse(epos.bh);
    return err;
}

static sector_t inode_getblk(struct inode *inode, sector_t block,
                 int *err, int *new)
{
    static sector_t last_block;
    struct kernel_long_ad laarr[EXTENT_MERGE_SIZE];
    struct extent_position prev_epos, cur_epos, next_epos;
    int count = 0, startnum = 0, endnum = 0;
    uint32_t elen = 0, tmpelen;
    struct kernel_lb_addr eloc, tmpeloc;
    int c = 1;
    loff_t lbcount = 0, b_off = 0;
    uint32_t newblocknum, newblock;
    sector_t offset = 0;
    int8_t etype;
    struct udf_inode_info *iinfo = UDF_I(inode);
    int goal = 0, pgoal = iinfo->i_location.logicalBlockNum;
    int lastblock = 0;

    *err = 0;
    *new = 0;
    prev_epos.offset = udf_file_entry_alloc_offset(inode);
    prev_epos.block = iinfo->i_location;
    prev_epos.bh = NULL;
    cur_epos = next_epos = prev_epos;
    b_off = (loff_t)block << inode->i_sb->s_blocksize_bits;

    /* find the extent which contains the block we are looking for.
       alternate between laarr[0] and laarr[1] for locations of the
       current extent, and the previous extent */
    do {
        if (prev_epos.bh != cur_epos.bh) {
            brelse(prev_epos.bh);
            get_bh(cur_epos.bh);
            prev_epos.bh = cur_epos.bh;
        }
        if (cur_epos.bh != next_epos.bh) {
            brelse(cur_epos.bh);
            get_bh(next_epos.bh);
            cur_epos.bh = next_epos.bh;
        }

        lbcount += elen;

        prev_epos.block = cur_epos.block;
        cur_epos.block = next_epos.block;

        prev_epos.offset = cur_epos.offset;
        cur_epos.offset = next_epos.offset;

        etype = udf_next_aext(inode, &next_epos, &eloc, &elen, 1);
        if (etype == -1)
            break;

        c = !c;

        laarr[c].extLength = (etype << 30) | elen;
        laarr[c].extLocation = eloc;

        if (etype != (EXT_NOT_RECORDED_NOT_ALLOCATED >> 30))
            pgoal = eloc.logicalBlockNum +
                ((elen + inode->i_sb->s_blocksize - 1) >>
                 inode->i_sb->s_blocksize_bits);

        count++;
    } while (lbcount + elen <= b_off);

    b_off -= lbcount;
    offset = b_off >> inode->i_sb->s_blocksize_bits;
    /*
     * Move prev_epos and cur_epos into indirect extent if we are at
     * the pointer to it
     */
    udf_next_aext(inode, &prev_epos, &tmpeloc, &tmpelen, 0);
    udf_next_aext(inode, &cur_epos, &tmpeloc, &tmpelen, 0);

    /* if the extent is allocated and recorded, return the block
       if the extent is not a multiple of the blocksize, round up */

    if (etype == (EXT_RECORDED_ALLOCATED >> 30)) {
        if (elen & (inode->i_sb->s_blocksize - 1)) {
            elen = EXT_RECORDED_ALLOCATED |
                ((elen + inode->i_sb->s_blocksize - 1) &
                 ~(inode->i_sb->s_blocksize - 1));
            udf_write_aext(inode, &cur_epos, &eloc, elen, 1);
        }
        brelse(prev_epos.bh);
        brelse(cur_epos.bh);
        brelse(next_epos.bh);
        newblock = udf_get_lb_pblock(inode->i_sb, &eloc, offset);
        return newblock;
    }

    last_block = block;
    /* Are we beyond EOF? */
    if (etype == -1) {
        int ret;

        if (count) {
            if (c)
                laarr[0] = laarr[1];
            startnum = 1;
        } else {
            /* Create a fake extent when there's not one */
            memset(&laarr[0].extLocation, 0x00,
                sizeof(struct kernel_lb_addr));
            laarr[0].extLength = EXT_NOT_RECORDED_NOT_ALLOCATED;
            /* Will udf_do_extend_file() create real extent from
               a fake one? */
            startnum = (offset > 0);
        }
        /* Create extents for the hole between EOF and offset */
        ret = udf_do_extend_file(inode, &prev_epos, laarr, offset);
        if (ret < 0) {
            brelse(prev_epos.bh);
            brelse(cur_epos.bh);
            brelse(next_epos.bh);
            *err = ret;
            return 0;
        }
        c = 0;
        offset = 0;
        count += ret;
        /* We are not covered by a preallocated extent? */
        if ((laarr[0].extLength & UDF_EXTENT_FLAG_MASK) !=
                        EXT_NOT_RECORDED_ALLOCATED) {
            /* Is there any real extent? - otherwise we overwrite
             * the fake one... */
            if (count)
                c = !c;
            laarr[c].extLength = EXT_NOT_RECORDED_NOT_ALLOCATED |
                inode->i_sb->s_blocksize;
            memset(&laarr[c].extLocation, 0x00,
                sizeof(struct kernel_lb_addr));
            count++;
            endnum++;
        }
        endnum = c + 1;
        lastblock = 1;
    } else {
        endnum = startnum = ((count > 2) ? 2 : count);

        /* if the current extent is in position 0,
           swap it with the previous */
        if (!c && count != 1) {
            laarr[2] = laarr[0];
            laarr[0] = laarr[1];
            laarr[1] = laarr[2];
            c = 1;
        }

        /* if the current block is located in an extent,
           read the next extent */
        etype = udf_next_aext(inode, &next_epos, &eloc, &elen, 0);
        if (etype != -1) {
            laarr[c + 1].extLength = (etype << 30) | elen;
            laarr[c + 1].extLocation = eloc;
            count++;
            startnum++;
            endnum++;
        } else
            lastblock = 1;
    }

    /* if the current extent is not recorded but allocated, get the
     * block in the extent corresponding to the requested block */
    if ((laarr[c].extLength >> 30) == (EXT_NOT_RECORDED_ALLOCATED >> 30))
        newblocknum = laarr[c].extLocation.logicalBlockNum + offset;
    else { /* otherwise, allocate a new block */
        if (iinfo->i_next_alloc_block == block)
            goal = iinfo->i_next_alloc_goal;

        if (!goal) {
            if (!(goal = pgoal)) /* XXX: what was intended here? */
                goal = iinfo->i_location.logicalBlockNum + 1;
        }

        newblocknum = udf_new_block(inode->i_sb, inode,
                iinfo->i_location.partitionReferenceNum,
                goal, err);
        if (!newblocknum) {
            brelse(prev_epos.bh);
            *err = -ENOSPC;
            return 0;
        }
        iinfo->i_lenExtents += inode->i_sb->s_blocksize;
    }

    /* if the extent the requsted block is located in contains multiple
     * blocks, split the extent into at most three extents. blocks prior
     * to requested block, requested block, and blocks after requested
     * block */
    udf_split_extents(inode, &c, offset, newblocknum, laarr, &endnum);

#ifdef UDF_PREALLOCATE
    /* We preallocate blocks only for regular files. It also makes sense
     * for directories but there's a problem when to drop the
     * preallocation. We might use some delayed work for that but I feel
     * it's overengineering for a filesystem like UDF. */
    if (S_ISREG(inode->i_mode))
        udf_prealloc_extents(inode, c, lastblock, laarr, &endnum);
#endif

    /* merge any continuous blocks in laarr */
    udf_merge_extents(inode, laarr, &endnum);

    /* write back the new extents, inserting new extents if the new number
     * of extents is greater than the old number, and deleting extents if
     * the new number of extents is less than the old number */
    udf_update_extents(inode, laarr, startnum, endnum, &prev_epos);

    brelse(prev_epos.bh);

    newblock = udf_get_pblock(inode->i_sb, newblocknum,
                iinfo->i_location.partitionReferenceNum, 0);
    if (!newblock) {
        *err = -EIO;
        return 0;
    }
    *new = 1;
    iinfo->i_next_alloc_block = block;
    iinfo->i_next_alloc_goal = newblocknum;
    inode->i_ctime = current_fs_time(inode->i_sb);

    if (IS_SYNC(inode))
        udf_sync_inode(inode);
    else
        mark_inode_dirty(inode);

    return newblock;
}

static void udf_split_extents(struct inode *inode, int *c, int offset,
                  int newblocknum,
                  struct kernel_long_ad laarr[EXTENT_MERGE_SIZE],
                  int *endnum)
{
    unsigned long blocksize = inode->i_sb->s_blocksize;
    unsigned char blocksize_bits = inode->i_sb->s_blocksize_bits;

    if ((laarr[*c].extLength >> 30) == (EXT_NOT_RECORDED_ALLOCATED >> 30) ||
        (laarr[*c].extLength >> 30) ==
                (EXT_NOT_RECORDED_NOT_ALLOCATED >> 30)) {
        int curr = *c;
        int blen = ((laarr[curr].extLength & UDF_EXTENT_LENGTH_MASK) +
                blocksize - 1) >> blocksize_bits;
        int8_t etype = (laarr[curr].extLength >> 30);

        if (blen == 1)
            ;
        else if (!offset || blen == offset + 1) {
            laarr[curr + 2] = laarr[curr + 1];
            laarr[curr + 1] = laarr[curr];
        } else {
            laarr[curr + 3] = laarr[curr + 1];
            laarr[curr + 2] = laarr[curr + 1] = laarr[curr];
        }

        if (offset) {
            if (etype == (EXT_NOT_RECORDED_ALLOCATED >> 30)) {
                udf_free_blocks(inode->i_sb, inode,
                        &laarr[curr].extLocation,
                        0, offset);
                laarr[curr].extLength =
                    EXT_NOT_RECORDED_NOT_ALLOCATED |
                    (offset << blocksize_bits);
                laarr[curr].extLocation.logicalBlockNum = 0;
                laarr[curr].extLocation.
                        partitionReferenceNum = 0;
            } else
                laarr[curr].extLength = (etype << 30) |
                    (offset << blocksize_bits);
            curr++;
            (*c)++;
            (*endnum)++;
        }

        laarr[curr].extLocation.logicalBlockNum = newblocknum;
        if (etype == (EXT_NOT_RECORDED_NOT_ALLOCATED >> 30))
            laarr[curr].extLocation.partitionReferenceNum =
                UDF_I(inode)->i_location.partitionReferenceNum;
        laarr[curr].extLength = EXT_RECORDED_ALLOCATED |
            blocksize;
        curr++;

        if (blen != offset + 1) {
            if (etype == (EXT_NOT_RECORDED_ALLOCATED >> 30))
                laarr[curr].extLocation.logicalBlockNum +=
                                offset + 1;
            laarr[curr].extLength = (etype << 30) |
                ((blen - (offset + 1)) << blocksize_bits);
            curr++;
            (*endnum)++;
        }
    }
}

static void udf_prealloc_extents(struct inode *inode, int c, int lastblock,
                 struct kernel_long_ad laarr[EXTENT_MERGE_SIZE],
                 int *endnum)
{
    int start, length = 0, currlength = 0, i;

    if (*endnum >= (c + 1)) {
        if (!lastblock)
            return;
        else
            start = c;
    } else {
        if ((laarr[c + 1].extLength >> 30) ==
                    (EXT_NOT_RECORDED_ALLOCATED >> 30)) {
            start = c + 1;
            length = currlength =
                (((laarr[c + 1].extLength &
                    UDF_EXTENT_LENGTH_MASK) +
                inode->i_sb->s_blocksize - 1) >>
                inode->i_sb->s_blocksize_bits);
        } else
            start = c;
    }

    for (i = start + 1; i <= *endnum; i++) {
        if (i == *endnum) {
            if (lastblock)
                length += UDF_DEFAULT_PREALLOC_BLOCKS;
        } else if ((laarr[i].extLength >> 30) ==
                (EXT_NOT_RECORDED_NOT_ALLOCATED >> 30)) {
            length += (((laarr[i].extLength &
                        UDF_EXTENT_LENGTH_MASK) +
                    inode->i_sb->s_blocksize - 1) >>
                    inode->i_sb->s_blocksize_bits);
        } else
            break;
    }

    if (length) {
        int next = laarr[start].extLocation.logicalBlockNum +
            (((laarr[start].extLength & UDF_EXTENT_LENGTH_MASK) +
              inode->i_sb->s_blocksize - 1) >>
              inode->i_sb->s_blocksize_bits);
        int numalloc = udf_prealloc_blocks(inode->i_sb, inode,
                laarr[start].extLocation.partitionReferenceNum,
                next, (UDF_DEFAULT_PREALLOC_BLOCKS > length ?
                length : UDF_DEFAULT_PREALLOC_BLOCKS) -
                currlength);
        if (numalloc)   {
            if (start == (c + 1))
                laarr[start].extLength +=
                    (numalloc <<
                     inode->i_sb->s_blocksize_bits);
            else {
                memmove(&laarr[c + 2], &laarr[c + 1],
                    sizeof(struct long_ad) * (*endnum - (c + 1)));
                (*endnum)++;
                laarr[c + 1].extLocation.logicalBlockNum = next;
                laarr[c + 1].extLocation.partitionReferenceNum =
                    laarr[c].extLocation.
                            partitionReferenceNum;
                laarr[c + 1].extLength =
                    EXT_NOT_RECORDED_ALLOCATED |
                    (numalloc <<
                     inode->i_sb->s_blocksize_bits);
                start = c + 1;
            }

            for (i = start + 1; numalloc && i < *endnum; i++) {
                int elen = ((laarr[i].extLength &
                        UDF_EXTENT_LENGTH_MASK) +
                        inode->i_sb->s_blocksize - 1) >>
                        inode->i_sb->s_blocksize_bits;

                if (elen > numalloc) {
                    laarr[i].extLength -=
                        (numalloc <<
                         inode->i_sb->s_blocksize_bits);
                    numalloc = 0;
                } else {
                    numalloc -= elen;
                    if (*endnum > (i + 1))
                        memmove(&laarr[i],
                            &laarr[i + 1],
                            sizeof(struct long_ad) *
                            (*endnum - (i + 1)));
                    i--;
                    (*endnum)--;
                }
            }
            UDF_I(inode)->i_lenExtents +=
                numalloc << inode->i_sb->s_blocksize_bits;
        }
    }
}

static void udf_merge_extents(struct inode *inode,
                  struct kernel_long_ad laarr[EXTENT_MERGE_SIZE],
                  int *endnum)
{
    int i;
    unsigned long blocksize = inode->i_sb->s_blocksize;
    unsigned char blocksize_bits = inode->i_sb->s_blocksize_bits;

    for (i = 0; i < (*endnum - 1); i++) {
        struct kernel_long_ad *li /*l[i]*/ = &laarr[i];
        struct kernel_long_ad *lip1 /*l[i plus 1]*/ = &laarr[i + 1];

        if (((li->extLength >> 30) == (lip1->extLength >> 30)) &&
            (((li->extLength >> 30) ==
                (EXT_NOT_RECORDED_NOT_ALLOCATED >> 30)) ||
            ((lip1->extLocation.logicalBlockNum -
              li->extLocation.logicalBlockNum) ==
            (((li->extLength & UDF_EXTENT_LENGTH_MASK) +
            blocksize - 1) >> blocksize_bits)))) {

            if (((li->extLength & UDF_EXTENT_LENGTH_MASK) +
                (lip1->extLength & UDF_EXTENT_LENGTH_MASK) +
                blocksize - 1) & ~UDF_EXTENT_LENGTH_MASK) {
                lip1->extLength = (lip1->extLength -
                          (li->extLength &
                           UDF_EXTENT_LENGTH_MASK) +
                           UDF_EXTENT_LENGTH_MASK) &
                            ~(blocksize - 1);
                li->extLength = (li->extLength &
                         UDF_EXTENT_FLAG_MASK) +
                        (UDF_EXTENT_LENGTH_MASK + 1) -
                        blocksize;
                lip1->extLocation.logicalBlockNum =
                    li->extLocation.logicalBlockNum +
                    ((li->extLength &
                        UDF_EXTENT_LENGTH_MASK) >>
                        blocksize_bits);
            } else {
                li->extLength = lip1->extLength +
                    (((li->extLength &
                        UDF_EXTENT_LENGTH_MASK) +
                     blocksize - 1) & ~(blocksize - 1));
                if (*endnum > (i + 2))
                    memmove(&laarr[i + 1], &laarr[i + 2],
                        sizeof(struct long_ad) *
                        (*endnum - (i + 2)));
                i--;
                (*endnum)--;
            }
        } else if (((li->extLength >> 30) ==
                (EXT_NOT_RECORDED_ALLOCATED >> 30)) &&
               ((lip1->extLength >> 30) ==
                (EXT_NOT_RECORDED_NOT_ALLOCATED >> 30))) {
            udf_free_blocks(inode->i_sb, inode, &li->extLocation, 0,
                    ((li->extLength &
                      UDF_EXTENT_LENGTH_MASK) +
                     blocksize - 1) >> blocksize_bits);
            li->extLocation.logicalBlockNum = 0;
            li->extLocation.partitionReferenceNum = 0;

            if (((li->extLength & UDF_EXTENT_LENGTH_MASK) +
                 (lip1->extLength & UDF_EXTENT_LENGTH_MASK) +
                 blocksize - 1) & ~UDF_EXTENT_LENGTH_MASK) {
                lip1->extLength = (lip1->extLength -
                           (li->extLength &
                           UDF_EXTENT_LENGTH_MASK) +
                           UDF_EXTENT_LENGTH_MASK) &
                           ~(blocksize - 1);
                li->extLength = (li->extLength &
                         UDF_EXTENT_FLAG_MASK) +
                        (UDF_EXTENT_LENGTH_MASK + 1) -
                        blocksize;
            } else {
                li->extLength = lip1->extLength +
                    (((li->extLength &
                        UDF_EXTENT_LENGTH_MASK) +
                      blocksize - 1) & ~(blocksize - 1));
                if (*endnum > (i + 2))
                    memmove(&laarr[i + 1], &laarr[i + 2],
                        sizeof(struct long_ad) *
                        (*endnum - (i + 2)));
                i--;
                (*endnum)--;
            }
        } else if ((li->extLength >> 30) ==
                    (EXT_NOT_RECORDED_ALLOCATED >> 30)) {
            udf_free_blocks(inode->i_sb, inode,
                    &li->extLocation, 0,
                    ((li->extLength &
                        UDF_EXTENT_LENGTH_MASK) +
                     blocksize - 1) >> blocksize_bits);
            li->extLocation.logicalBlockNum = 0;
            li->extLocation.partitionReferenceNum = 0;
            li->extLength = (li->extLength &
                        UDF_EXTENT_LENGTH_MASK) |
                        EXT_NOT_RECORDED_NOT_ALLOCATED;
        }
    }
}

static void udf_update_extents(struct inode *inode,
                   struct kernel_long_ad laarr[EXTENT_MERGE_SIZE],
                   int startnum, int endnum,
                   struct extent_position *epos)
{
    int start = 0, i;
    struct kernel_lb_addr tmploc;
    uint32_t tmplen;

    if (startnum > endnum) {
        for (i = 0; i < (startnum - endnum); i++)
            udf_delete_aext(inode, *epos, laarr[i].extLocation,
                    laarr[i].extLength);
    } else if (startnum < endnum) {
        for (i = 0; i < (endnum - startnum); i++) {
            udf_insert_aext(inode, *epos, laarr[i].extLocation,
                    laarr[i].extLength);
            udf_next_aext(inode, epos, &laarr[i].extLocation,
                      &laarr[i].extLength, 1);
            start++;
        }
    }

    for (i = start; i < endnum; i++) {
        udf_next_aext(inode, epos, &tmploc, &tmplen, 0);
        udf_write_aext(inode, epos, &laarr[i].extLocation,
                   laarr[i].extLength, 1);
    }
}

struct buffer_head *udf_bread(struct inode *inode, int block,
                  int create, int *err)
{
    struct buffer_head *bh = NULL;

    bh = udf_getblk(inode, block, create, err);
    if (!bh)
        return NULL;

    if (buffer_uptodate(bh))
        return bh;

    ll_rw_block(READ, 1, &bh);

    wait_on_buffer(bh);
    if (buffer_uptodate(bh))
        return bh;

    brelse(bh);
    *err = -EIO;
    return NULL;
}

int udf_setsize(struct inode *inode, loff_t newsize)
{
    int err;
    struct udf_inode_info *iinfo;
    int bsize = 1 << inode->i_blkbits;

    if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
          S_ISLNK(inode->i_mode)))
        return -EINVAL;
    if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
        return -EPERM;

    iinfo = UDF_I(inode);
    if (newsize > inode->i_size) {
        down_write(&iinfo->i_data_sem);
        if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
            if (bsize <
                (udf_file_entry_alloc_offset(inode) + newsize)) {
                err = udf_expand_file_adinicb(inode);
                if (err)
                    return err;
                down_write(&iinfo->i_data_sem);
            } else {
                iinfo->i_lenAlloc = newsize;
                goto set_size;
            }
        }
        err = udf_extend_file(inode, newsize);
        if (err) {
            up_write(&iinfo->i_data_sem);
            return err;
        }
set_size:
        truncate_setsize(inode, newsize);
        up_write(&iinfo->i_data_sem);
    } else {
        if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
            down_write(&iinfo->i_data_sem);
            memset(iinfo->i_ext.i_data + iinfo->i_lenEAttr + newsize,
                   0x00, bsize - newsize -
                   udf_file_entry_alloc_offset(inode));
            iinfo->i_lenAlloc = newsize;
            truncate_setsize(inode, newsize);
            up_write(&iinfo->i_data_sem);
            goto update_time;
        }
        err = block_truncate_page(inode->i_mapping, newsize,
                      udf_get_block);
        if (err)
            return err;
        down_write(&iinfo->i_data_sem);
        truncate_setsize(inode, newsize);
        udf_truncate_extents(inode);
        up_write(&iinfo->i_data_sem);
    }
update_time:
    inode->i_mtime = inode->i_ctime = current_fs_time(inode->i_sb);
    if (IS_SYNC(inode))
        udf_sync_inode(inode);
    else
        mark_inode_dirty(inode);
    return 0;
}

static void __udf_read_inode(struct inode *inode)
{
    struct buffer_head *bh = NULL;
    struct fileEntry *fe;
    uint16_t ident;
    struct udf_inode_info *iinfo = UDF_I(inode);

    /*
     * Set defaults, but the inode is still incomplete!
     * Note: get_new_inode() sets the following on a new inode:
     *      i_sb = sb
     *      i_no = ino
     *      i_flags = sb->s_flags
     *      i_state = 0
     * clean_inode(): zero fills and sets
     *      i_count = 1
     *      i_nlink = 1
     *      i_op = NULL;
     */
    bh = udf_read_ptagged(inode->i_sb, &iinfo->i_location, 0, &ident);
    if (!bh) {
        udf_err(inode->i_sb, "(ino %ld) failed !bh\n", inode->i_ino);
        make_bad_inode(inode);
        return;
    }

    if (ident != TAG_IDENT_FE && ident != TAG_IDENT_EFE &&
        ident != TAG_IDENT_USE) {
        udf_err(inode->i_sb, "(ino %ld) failed ident=%d\n",
            inode->i_ino, ident);
        brelse(bh);
        make_bad_inode(inode);
        return;
    }

    fe = (struct fileEntry *)bh->b_data;

    if (fe->icbTag.strategyType == cpu_to_le16(4096)) {
        struct buffer_head *ibh;

        ibh = udf_read_ptagged(inode->i_sb, &iinfo->i_location, 1,
                    &ident);
        if (ident == TAG_IDENT_IE && ibh) {
            struct buffer_head *nbh = NULL;
            struct kernel_lb_addr loc;
            struct indirectEntry *ie;

            ie = (struct indirectEntry *)ibh->b_data;
            loc = lelb_to_cpu(ie->indirectICB.extLocation);

            if (ie->indirectICB.extLength &&
                (nbh = udf_read_ptagged(inode->i_sb, &loc, 0,
                            &ident))) {
                if (ident == TAG_IDENT_FE ||
                    ident == TAG_IDENT_EFE) {
                    memcpy(&iinfo->i_location,
                        &loc,
                        sizeof(struct kernel_lb_addr));
                    brelse(bh);
                    brelse(ibh);
                    brelse(nbh);
                    __udf_read_inode(inode);
                    return;
                }
                brelse(nbh);
            }
        }
        brelse(ibh);
    } else if (fe->icbTag.strategyType != cpu_to_le16(4)) {
        udf_err(inode->i_sb, "unsupported strategy type: %d\n",
            le16_to_cpu(fe->icbTag.strategyType));
        brelse(bh);
        make_bad_inode(inode);
        return;
    }
    udf_fill_inode(inode, bh);

    brelse(bh);
}

static void udf_fill_inode(struct inode *inode, struct buffer_head *bh)
{
    struct fileEntry *fe;
    struct extendedFileEntry *efe;
    struct udf_sb_info *sbi = UDF_SB(inode->i_sb);
    struct udf_inode_info *iinfo = UDF_I(inode);
    unsigned int link_count;

    fe = (struct fileEntry *)bh->b_data;
    efe = (struct extendedFileEntry *)bh->b_data;

    if (fe->icbTag.strategyType == cpu_to_le16(4))
        iinfo->i_strat4096 = 0;
    else /* if (fe->icbTag.strategyType == cpu_to_le16(4096)) */
        iinfo->i_strat4096 = 1;

    iinfo->i_alloc_type = le16_to_cpu(fe->icbTag.flags) &
                            ICBTAG_FLAG_AD_MASK;
    iinfo->i_unique = 0;
    iinfo->i_lenEAttr = 0;
    iinfo->i_lenExtents = 0;
    iinfo->i_lenAlloc = 0;
    iinfo->i_next_alloc_block = 0;
    iinfo->i_next_alloc_goal = 0;
    if (fe->descTag.tagIdent == cpu_to_le16(TAG_IDENT_EFE)) {
        iinfo->i_efe = 1;
        iinfo->i_use = 0;
        if (udf_alloc_i_data(inode, inode->i_sb->s_blocksize -
                    sizeof(struct extendedFileEntry))) {
            make_bad_inode(inode);
            return;
        }
        memcpy(iinfo->i_ext.i_data,
               bh->b_data + sizeof(struct extendedFileEntry),
               inode->i_sb->s_blocksize -
                    sizeof(struct extendedFileEntry));
    } else if (fe->descTag.tagIdent == cpu_to_le16(TAG_IDENT_FE)) {
        iinfo->i_efe = 0;
        iinfo->i_use = 0;
        if (udf_alloc_i_data(inode, inode->i_sb->s_blocksize -
                        sizeof(struct fileEntry))) {
            make_bad_inode(inode);
            return;
        }
        memcpy(iinfo->i_ext.i_data,
               bh->b_data + sizeof(struct fileEntry),
               inode->i_sb->s_blocksize - sizeof(struct fileEntry));
    } else if (fe->descTag.tagIdent == cpu_to_le16(TAG_IDENT_USE)) {
        iinfo->i_efe = 0;
        iinfo->i_use = 1;
        iinfo->i_lenAlloc = le32_to_cpu(
                ((struct unallocSpaceEntry *)bh->b_data)->
                 lengthAllocDescs);
        if (udf_alloc_i_data(inode, inode->i_sb->s_blocksize -
                    sizeof(struct unallocSpaceEntry))) {
            make_bad_inode(inode);
            return;
        }
        memcpy(iinfo->i_ext.i_data,
               bh->b_data + sizeof(struct unallocSpaceEntry),
               inode->i_sb->s_blocksize -
                    sizeof(struct unallocSpaceEntry));
        return;
    }

    read_lock(&sbi->s_cred_lock);
    i_uid_write(inode, le32_to_cpu(fe->uid));
    if (!uid_valid(inode->i_uid) ||
        UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_UID_IGNORE) ||
        UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_UID_SET))
        inode->i_uid = UDF_SB(inode->i_sb)->s_uid;

    i_gid_write(inode, le32_to_cpu(fe->gid));
    if (!gid_valid(inode->i_gid) ||
        UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_GID_IGNORE) ||
        UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_GID_SET))
        inode->i_gid = UDF_SB(inode->i_sb)->s_gid;

    if (fe->icbTag.fileType != ICBTAG_FILE_TYPE_DIRECTORY &&
            sbi->s_fmode != UDF_INVALID_MODE)
        inode->i_mode = sbi->s_fmode;
    else if (fe->icbTag.fileType == ICBTAG_FILE_TYPE_DIRECTORY &&
            sbi->s_dmode != UDF_INVALID_MODE)
        inode->i_mode = sbi->s_dmode;
    else
        inode->i_mode = udf_convert_permissions(fe);
    inode->i_mode &= ~sbi->s_umask;
    read_unlock(&sbi->s_cred_lock);

    link_count = le16_to_cpu(fe->fileLinkCount);
    if (!link_count)
        link_count = 1;
    set_nlink(inode, link_count);

    inode->i_size = le64_to_cpu(fe->informationLength);
    iinfo->i_lenExtents = inode->i_size;

    if (iinfo->i_efe == 0) {
        inode->i_blocks = le64_to_cpu(fe->logicalBlocksRecorded) <<
            (inode->i_sb->s_blocksize_bits - 9);

        if (!udf_disk_stamp_to_time(&inode->i_atime, fe->accessTime))
            inode->i_atime = sbi->s_record_time;

        if (!udf_disk_stamp_to_time(&inode->i_mtime,
                        fe->modificationTime))
            inode->i_mtime = sbi->s_record_time;

        if (!udf_disk_stamp_to_time(&inode->i_ctime, fe->attrTime))
            inode->i_ctime = sbi->s_record_time;

        iinfo->i_unique = le64_to_cpu(fe->uniqueID);
        iinfo->i_lenEAttr = le32_to_cpu(fe->lengthExtendedAttr);
        iinfo->i_lenAlloc = le32_to_cpu(fe->lengthAllocDescs);
        iinfo->i_checkpoint = le32_to_cpu(fe->checkpoint);
    } else {
        inode->i_blocks = le64_to_cpu(efe->logicalBlocksRecorded) <<
            (inode->i_sb->s_blocksize_bits - 9);

        if (!udf_disk_stamp_to_time(&inode->i_atime, efe->accessTime))
            inode->i_atime = sbi->s_record_time;

        if (!udf_disk_stamp_to_time(&inode->i_mtime,
                        efe->modificationTime))
            inode->i_mtime = sbi->s_record_time;

        if (!udf_disk_stamp_to_time(&iinfo->i_crtime, efe->createTime))
            iinfo->i_crtime = sbi->s_record_time;

        if (!udf_disk_stamp_to_time(&inode->i_ctime, efe->attrTime))
            inode->i_ctime = sbi->s_record_time;

        iinfo->i_unique = le64_to_cpu(efe->uniqueID);
        iinfo->i_lenEAttr = le32_to_cpu(efe->lengthExtendedAttr);
        iinfo->i_lenAlloc = le32_to_cpu(efe->lengthAllocDescs);
        iinfo->i_checkpoint = le32_to_cpu(efe->checkpoint);
    }

    switch (fe->icbTag.fileType) {
    case ICBTAG_FILE_TYPE_DIRECTORY:
        inode->i_op = &udf_dir_inode_operations;
        inode->i_fop = &udf_dir_operations;
        inode->i_mode |= S_IFDIR;
        inc_nlink(inode);
        break;
    case ICBTAG_FILE_TYPE_REALTIME:
    case ICBTAG_FILE_TYPE_REGULAR:
    case ICBTAG_FILE_TYPE_UNDEF:
    case ICBTAG_FILE_TYPE_VAT20:
        if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB)
            inode->i_data.a_ops = &udf_adinicb_aops;
        else
            inode->i_data.a_ops = &udf_aops;
        inode->i_op = &udf_file_inode_operations;
        inode->i_fop = &udf_file_operations;
        inode->i_mode |= S_IFREG;
        break;
    case ICBTAG_FILE_TYPE_BLOCK:
        inode->i_mode |= S_IFBLK;
        break;
    case ICBTAG_FILE_TYPE_CHAR:
        inode->i_mode |= S_IFCHR;
        break;
    case ICBTAG_FILE_TYPE_FIFO:
        init_special_inode(inode, inode->i_mode | S_IFIFO, 0);
        break;
    case ICBTAG_FILE_TYPE_SOCKET:
        init_special_inode(inode, inode->i_mode | S_IFSOCK, 0);
        break;
    case ICBTAG_FILE_TYPE_SYMLINK:
        inode->i_data.a_ops = &udf_symlink_aops;
        inode->i_op = &udf_symlink_inode_operations;
        inode->i_mode = S_IFLNK | S_IRWXUGO;
        break;
    case ICBTAG_FILE_TYPE_MAIN:
        udf_debug("METADATA FILE-----\n");
        break;
    case ICBTAG_FILE_TYPE_MIRROR:
        udf_debug("METADATA MIRROR FILE-----\n");
        break;
    case ICBTAG_FILE_TYPE_BITMAP:
        udf_debug("METADATA BITMAP FILE-----\n");
        break;
    default:
        udf_err(inode->i_sb, "(ino %ld) failed unknown file type=%d\n",
            inode->i_ino, fe->icbTag.fileType);
        make_bad_inode(inode);
        return;
    }
    if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
        struct deviceSpec *dsea =
            (struct deviceSpec *)udf_get_extendedattr(inode, 12, 1);
        if (dsea) {
            init_special_inode(inode, inode->i_mode,
                MKDEV(le32_to_cpu(dsea->majorDeviceIdent),
                      le32_to_cpu(dsea->minorDeviceIdent)));
            /* Developer ID ??? */
        } else
            make_bad_inode(inode);
    }
}

static int udf_alloc_i_data(struct inode *inode, size_t size)
{
    struct udf_inode_info *iinfo = UDF_I(inode);
    iinfo->i_ext.i_data = kmalloc(size, GFP_KERNEL);

    if (!iinfo->i_ext.i_data) {
        udf_err(inode->i_sb, "(ino %ld) no free memory\n",
            inode->i_ino);
        return -ENOMEM;
    }

    return 0;
}

static umode_t udf_convert_permissions(struct fileEntry *fe)
{
    umode_t mode;
    uint32_t permissions;
    uint32_t flags;

    permissions = le32_to_cpu(fe->permissions);
    flags = le16_to_cpu(fe->icbTag.flags);

    mode =  ((permissions) & S_IRWXO) |
        ((permissions >> 2) & S_IRWXG) |
        ((permissions >> 4) & S_IRWXU) |
        ((flags & ICBTAG_FLAG_SETUID) ? S_ISUID : 0) |
        ((flags & ICBTAG_FLAG_SETGID) ? S_ISGID : 0) |
        ((flags & ICBTAG_FLAG_STICKY) ? S_ISVTX : 0);

    return mode;
}

int udf_write_inode(struct inode *inode, struct writeback_control *wbc)
{
    return udf_update_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
}

static int udf_sync_inode(struct inode *inode)
{
    return udf_update_inode(inode, 1);
}

static int udf_update_inode(struct inode *inode, int do_sync)
{
    struct buffer_head *bh = NULL;
    struct fileEntry *fe;
    struct extendedFileEntry *efe;
    uint64_t lb_recorded;
    uint32_t udfperms;
    uint16_t icbflags;
    uint16_t crclen;
    int err = 0;
    struct udf_sb_info *sbi = UDF_SB(inode->i_sb);
    unsigned char blocksize_bits = inode->i_sb->s_blocksize_bits;
    struct udf_inode_info *iinfo = UDF_I(inode);

    bh = udf_tgetblk(inode->i_sb,
            udf_get_lb_pblock(inode->i_sb, &iinfo->i_location, 0));
    if (!bh) {
        udf_debug("getblk failure\n");
        return -ENOMEM;
    }

    lock_buffer(bh);
    memset(bh->b_data, 0, inode->i_sb->s_blocksize);
    fe = (struct fileEntry *)bh->b_data;
    efe = (struct extendedFileEntry *)bh->b_data;

    if (iinfo->i_use) {
        struct unallocSpaceEntry *use =
            (struct unallocSpaceEntry *)bh->b_data;

        use->lengthAllocDescs = cpu_to_le32(iinfo->i_lenAlloc);
        memcpy(bh->b_data + sizeof(struct unallocSpaceEntry),
               iinfo->i_ext.i_data, inode->i_sb->s_blocksize -
                    sizeof(struct unallocSpaceEntry));
        use->descTag.tagIdent = cpu_to_le16(TAG_IDENT_USE);
        use->descTag.tagLocation =
                cpu_to_le32(iinfo->i_location.logicalBlockNum);
        crclen = sizeof(struct unallocSpaceEntry) +
                iinfo->i_lenAlloc - sizeof(struct tag);
        use->descTag.descCRCLength = cpu_to_le16(crclen);
        use->descTag.descCRC = cpu_to_le16(crc_itu_t(0, (char *)use +
                               sizeof(struct tag),
                               crclen));
        use->descTag.tagChecksum = udf_tag_checksum(&use->descTag);

        goto out;
    }

    if (UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_UID_FORGET))
        fe->uid = cpu_to_le32(-1);
    else
        fe->uid = cpu_to_le32(i_uid_read(inode));

    if (UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_GID_FORGET))
        fe->gid = cpu_to_le32(-1);
    else
        fe->gid = cpu_to_le32(i_gid_read(inode));

    udfperms = ((inode->i_mode & S_IRWXO)) |
           ((inode->i_mode & S_IRWXG) << 2) |
           ((inode->i_mode & S_IRWXU) << 4);

    udfperms |= (le32_to_cpu(fe->permissions) &
            (FE_PERM_O_DELETE | FE_PERM_O_CHATTR |
             FE_PERM_G_DELETE | FE_PERM_G_CHATTR |
             FE_PERM_U_DELETE | FE_PERM_U_CHATTR));
    fe->permissions = cpu_to_le32(udfperms);

    if (S_ISDIR(inode->i_mode))
        fe->fileLinkCount = cpu_to_le16(inode->i_nlink - 1);
    else
        fe->fileLinkCount = cpu_to_le16(inode->i_nlink);

    fe->informationLength = cpu_to_le64(inode->i_size);

    if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
        struct regid *eid;
        struct deviceSpec *dsea =
            (struct deviceSpec *)udf_get_extendedattr(inode, 12, 1);
        if (!dsea) {
            dsea = (struct deviceSpec *)
                udf_add_extendedattr(inode,
                             sizeof(struct deviceSpec) +
                             sizeof(struct regid), 12, 0x3);
            dsea->attrType = cpu_to_le32(12);
            dsea->attrSubtype = 1;
            dsea->attrLength = cpu_to_le32(
                        sizeof(struct deviceSpec) +
                        sizeof(struct regid));
            dsea->impUseLength = cpu_to_le32(sizeof(struct regid));
        }
        eid = (struct regid *)dsea->impUse;
        memset(eid, 0, sizeof(struct regid));
        strcpy(eid->ident, UDF_ID_DEVELOPER);
        eid->identSuffix[0] = UDF_OS_CLASS_UNIX;
        eid->identSuffix[1] = UDF_OS_ID_LINUX;
        dsea->majorDeviceIdent = cpu_to_le32(imajor(inode));
        dsea->minorDeviceIdent = cpu_to_le32(iminor(inode));
    }

    if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB)
        lb_recorded = 0; /* No extents => no blocks! */
    else
        lb_recorded =
            (inode->i_blocks + (1 << (blocksize_bits - 9)) - 1) >>
            (blocksize_bits - 9);

    if (iinfo->i_efe == 0) {
        memcpy(bh->b_data + sizeof(struct fileEntry),
               iinfo->i_ext.i_data,
               inode->i_sb->s_blocksize - sizeof(struct fileEntry));
        fe->logicalBlocksRecorded = cpu_to_le64(lb_recorded);

        udf_time_to_disk_stamp(&fe->accessTime, inode->i_atime);
        udf_time_to_disk_stamp(&fe->modificationTime, inode->i_mtime);
        udf_time_to_disk_stamp(&fe->attrTime, inode->i_ctime);
        memset(&(fe->impIdent), 0, sizeof(struct regid));
        strcpy(fe->impIdent.ident, UDF_ID_DEVELOPER);
        fe->impIdent.identSuffix[0] = UDF_OS_CLASS_UNIX;
        fe->impIdent.identSuffix[1] = UDF_OS_ID_LINUX;
        fe->uniqueID = cpu_to_le64(iinfo->i_unique);
        fe->lengthExtendedAttr = cpu_to_le32(iinfo->i_lenEAttr);
        fe->lengthAllocDescs = cpu_to_le32(iinfo->i_lenAlloc);
        fe->checkpoint = cpu_to_le32(iinfo->i_checkpoint);
        fe->descTag.tagIdent = cpu_to_le16(TAG_IDENT_FE);
        crclen = sizeof(struct fileEntry);
    } else {
        memcpy(bh->b_data + sizeof(struct extendedFileEntry),
               iinfo->i_ext.i_data,
               inode->i_sb->s_blocksize -
                    sizeof(struct extendedFileEntry));
        efe->objectSize = cpu_to_le64(inode->i_size);
        efe->logicalBlocksRecorded = cpu_to_le64(lb_recorded);

        if (iinfo->i_crtime.tv_sec > inode->i_atime.tv_sec ||
            (iinfo->i_crtime.tv_sec == inode->i_atime.tv_sec &&
             iinfo->i_crtime.tv_nsec > inode->i_atime.tv_nsec))
            iinfo->i_crtime = inode->i_atime;

        if (iinfo->i_crtime.tv_sec > inode->i_mtime.tv_sec ||
            (iinfo->i_crtime.tv_sec == inode->i_mtime.tv_sec &&
             iinfo->i_crtime.tv_nsec > inode->i_mtime.tv_nsec))
            iinfo->i_crtime = inode->i_mtime;

        if (iinfo->i_crtime.tv_sec > inode->i_ctime.tv_sec ||
            (iinfo->i_crtime.tv_sec == inode->i_ctime.tv_sec &&
             iinfo->i_crtime.tv_nsec > inode->i_ctime.tv_nsec))
            iinfo->i_crtime = inode->i_ctime;

        udf_time_to_disk_stamp(&efe->accessTime, inode->i_atime);
        udf_time_to_disk_stamp(&efe->modificationTime, inode->i_mtime);
        udf_time_to_disk_stamp(&efe->createTime, iinfo->i_crtime);
        udf_time_to_disk_stamp(&efe->attrTime, inode->i_ctime);

        memset(&(efe->impIdent), 0, sizeof(struct regid));
        strcpy(efe->impIdent.ident, UDF_ID_DEVELOPER);
        efe->impIdent.identSuffix[0] = UDF_OS_CLASS_UNIX;
        efe->impIdent.identSuffix[1] = UDF_OS_ID_LINUX;
        efe->uniqueID = cpu_to_le64(iinfo->i_unique);
        efe->lengthExtendedAttr = cpu_to_le32(iinfo->i_lenEAttr);
        efe->lengthAllocDescs = cpu_to_le32(iinfo->i_lenAlloc);
        efe->checkpoint = cpu_to_le32(iinfo->i_checkpoint);
        efe->descTag.tagIdent = cpu_to_le16(TAG_IDENT_EFE);
        crclen = sizeof(struct extendedFileEntry);
    }
    if (iinfo->i_strat4096) {
        fe->icbTag.strategyType = cpu_to_le16(4096);
        fe->icbTag.strategyParameter = cpu_to_le16(1);
        fe->icbTag.numEntries = cpu_to_le16(2);
    } else {
        fe->icbTag.strategyType = cpu_to_le16(4);
        fe->icbTag.numEntries = cpu_to_le16(1);
    }

    if (S_ISDIR(inode->i_mode))
        fe->icbTag.fileType = ICBTAG_FILE_TYPE_DIRECTORY;
    else if (S_ISREG(inode->i_mode))
        fe->icbTag.fileType = ICBTAG_FILE_TYPE_REGULAR;
    else if (S_ISLNK(inode->i_mode))
        fe->icbTag.fileType = ICBTAG_FILE_TYPE_SYMLINK;
    else if (S_ISBLK(inode->i_mode))
        fe->icbTag.fileType = ICBTAG_FILE_TYPE_BLOCK;
    else if (S_ISCHR(inode->i_mode))
        fe->icbTag.fileType = ICBTAG_FILE_TYPE_CHAR;
    else if (S_ISFIFO(inode->i_mode))
        fe->icbTag.fileType = ICBTAG_FILE_TYPE_FIFO;
    else if (S_ISSOCK(inode->i_mode))
        fe->icbTag.fileType = ICBTAG_FILE_TYPE_SOCKET;

    icbflags =  iinfo->i_alloc_type |
            ((inode->i_mode & S_ISUID) ? ICBTAG_FLAG_SETUID : 0) |
            ((inode->i_mode & S_ISGID) ? ICBTAG_FLAG_SETGID : 0) |
            ((inode->i_mode & S_ISVTX) ? ICBTAG_FLAG_STICKY : 0) |
            (le16_to_cpu(fe->icbTag.flags) &
                ~(ICBTAG_FLAG_AD_MASK | ICBTAG_FLAG_SETUID |
                ICBTAG_FLAG_SETGID | ICBTAG_FLAG_STICKY));

    fe->icbTag.flags = cpu_to_le16(icbflags);
    if (sbi->s_udfrev >= 0x0200)
        fe->descTag.descVersion = cpu_to_le16(3);
    else
        fe->descTag.descVersion = cpu_to_le16(2);
    fe->descTag.tagSerialNum = cpu_to_le16(sbi->s_serial_number);
    fe->descTag.tagLocation = cpu_to_le32(
                    iinfo->i_location.logicalBlockNum);
    crclen += iinfo->i_lenEAttr + iinfo->i_lenAlloc - sizeof(struct tag);
    fe->descTag.descCRCLength = cpu_to_le16(crclen);
    fe->descTag.descCRC = cpu_to_le16(crc_itu_t(0, (char *)fe + sizeof(struct tag),
                          crclen));
    fe->descTag.tagChecksum = udf_tag_checksum(&fe->descTag);

out:
    set_buffer_uptodate(bh);
    unlock_buffer(bh);

    /* write the data blocks */
    mark_buffer_dirty(bh);
    if (do_sync) {
        sync_dirty_buffer(bh);
        if (buffer_write_io_error(bh)) {
            udf_warn(inode->i_sb, "IO error syncing udf inode [%08lx]\n",
                 inode->i_ino);
            err = -EIO;
        }
    }
    brelse(bh);

    return err;
}

struct inode *udf_iget(struct super_block *sb, struct kernel_lb_addr *ino)
{
    unsigned long block = udf_get_lb_pblock(sb, ino, 0);
    struct inode *inode = iget_locked(sb, block);

    if (!inode)
        return NULL;

    if (inode->i_state & I_NEW) {
        memcpy(&UDF_I(inode)->i_location, ino, sizeof(struct kernel_lb_addr));
        __udf_read_inode(inode);
        unlock_new_inode(inode);
    }

    if (is_bad_inode(inode))
        goto out_iput;

    if (ino->logicalBlockNum >= UDF_SB(sb)->
            s_partmaps[ino->partitionReferenceNum].s_partition_len) {
        udf_debug("block=%d, partition=%d out of range\n",
              ino->logicalBlockNum, ino->partitionReferenceNum);
        make_bad_inode(inode);
        goto out_iput;
    }

    return inode;

 out_iput:
    iput(inode);
    return NULL;
}

int udf_add_aext(struct inode *inode, struct extent_position *epos,
         struct kernel_lb_addr *eloc, uint32_t elen, int inc)
{
    int adsize;
    struct short_ad *sad = NULL;
    struct long_ad *lad = NULL;
    struct allocExtDesc *aed;
    uint8_t *ptr;
    struct udf_inode_info *iinfo = UDF_I(inode);

    if (!epos->bh)
        ptr = iinfo->i_ext.i_data + epos->offset -
            udf_file_entry_alloc_offset(inode) +
            iinfo->i_lenEAttr;
    else
        ptr = epos->bh->b_data + epos->offset;

    if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
        adsize = sizeof(struct short_ad);
    else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
        adsize = sizeof(struct long_ad);
    else
        return -EIO;

    if (epos->offset + (2 * adsize) > inode->i_sb->s_blocksize) {
        unsigned char *sptr, *dptr;
        struct buffer_head *nbh;
        int err, loffset;
        struct kernel_lb_addr obloc = epos->block;

        epos->block.logicalBlockNum = udf_new_block(inode->i_sb, NULL,
                        obloc.partitionReferenceNum,
                        obloc.logicalBlockNum, &err);
        if (!epos->block.logicalBlockNum)
            return -ENOSPC;
        nbh = udf_tgetblk(inode->i_sb, udf_get_lb_pblock(inode->i_sb,
                                 &epos->block,
                                 0));
        if (!nbh)
            return -EIO;
        lock_buffer(nbh);
        memset(nbh->b_data, 0x00, inode->i_sb->s_blocksize);
        set_buffer_uptodate(nbh);
        unlock_buffer(nbh);
        mark_buffer_dirty_inode(nbh, inode);

        aed = (struct allocExtDesc *)(nbh->b_data);
        if (!UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_STRICT))
            aed->previousAllocExtLocation =
                    cpu_to_le32(obloc.logicalBlockNum);
        if (epos->offset + adsize > inode->i_sb->s_blocksize) {
            loffset = epos->offset;
            aed->lengthAllocDescs = cpu_to_le32(adsize);
            sptr = ptr - adsize;
            dptr = nbh->b_data + sizeof(struct allocExtDesc);
            memcpy(dptr, sptr, adsize);
            epos->offset = sizeof(struct allocExtDesc) + adsize;
        } else {
            loffset = epos->offset + adsize;
            aed->lengthAllocDescs = cpu_to_le32(0);
            sptr = ptr;
            epos->offset = sizeof(struct allocExtDesc);

            if (epos->bh) {
                aed = (struct allocExtDesc *)epos->bh->b_data;
                le32_add_cpu(&aed->lengthAllocDescs, adsize);
            } else {
                iinfo->i_lenAlloc += adsize;
                mark_inode_dirty(inode);
            }
        }
        if (UDF_SB(inode->i_sb)->s_udfrev >= 0x0200)
            udf_new_tag(nbh->b_data, TAG_IDENT_AED, 3, 1,
                    epos->block.logicalBlockNum, sizeof(struct tag));
        else
            udf_new_tag(nbh->b_data, TAG_IDENT_AED, 2, 1,
                    epos->block.logicalBlockNum, sizeof(struct tag));
        switch (iinfo->i_alloc_type) {
        case ICBTAG_FLAG_AD_SHORT:
            sad = (struct short_ad *)sptr;
            sad->extLength = cpu_to_le32(EXT_NEXT_EXTENT_ALLOCDECS |
                             inode->i_sb->s_blocksize);
            sad->extPosition =
                cpu_to_le32(epos->block.logicalBlockNum);
            break;
        case ICBTAG_FLAG_AD_LONG:
            lad = (struct long_ad *)sptr;
            lad->extLength = cpu_to_le32(EXT_NEXT_EXTENT_ALLOCDECS |
                             inode->i_sb->s_blocksize);
            lad->extLocation = cpu_to_lelb(epos->block);
            memset(lad->impUse, 0x00, sizeof(lad->impUse));
            break;
        }
        if (epos->bh) {
            if (!UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_STRICT) ||
                UDF_SB(inode->i_sb)->s_udfrev >= 0x0201)
                udf_update_tag(epos->bh->b_data, loffset);
            else
                udf_update_tag(epos->bh->b_data,
                        sizeof(struct allocExtDesc));
            mark_buffer_dirty_inode(epos->bh, inode);
            brelse(epos->bh);
        } else {
            mark_inode_dirty(inode);
        }
        epos->bh = nbh;
    }

    udf_write_aext(inode, epos, eloc, elen, inc);

    if (!epos->bh) {
        iinfo->i_lenAlloc += adsize;
        mark_inode_dirty(inode);
    } else {
        aed = (struct allocExtDesc *)epos->bh->b_data;
        le32_add_cpu(&aed->lengthAllocDescs, adsize);
        if (!UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_STRICT) ||
                UDF_SB(inode->i_sb)->s_udfrev >= 0x0201)
            udf_update_tag(epos->bh->b_data,
                    epos->offset + (inc ? 0 : adsize));
        else
            udf_update_tag(epos->bh->b_data,
                    sizeof(struct allocExtDesc));
        mark_buffer_dirty_inode(epos->bh, inode);
    }

    return 0;
}

void udf_write_aext(struct inode *inode, struct extent_position *epos,
            struct kernel_lb_addr *eloc, uint32_t elen, int inc)
{
    int adsize;
    uint8_t *ptr;
    struct short_ad *sad;
    struct long_ad *lad;
    struct udf_inode_info *iinfo = UDF_I(inode);

    if (!epos->bh)
        ptr = iinfo->i_ext.i_data + epos->offset -
            udf_file_entry_alloc_offset(inode) +
            iinfo->i_lenEAttr;
    else
        ptr = epos->bh->b_data + epos->offset;

    switch (iinfo->i_alloc_type) {
    case ICBTAG_FLAG_AD_SHORT:
        sad = (struct short_ad *)ptr;
        sad->extLength = cpu_to_le32(elen);
        sad->extPosition = cpu_to_le32(eloc->logicalBlockNum);
        adsize = sizeof(struct short_ad);
        break;
    case ICBTAG_FLAG_AD_LONG:
        lad = (struct long_ad *)ptr;
        lad->extLength = cpu_to_le32(elen);
        lad->extLocation = cpu_to_lelb(*eloc);
        memset(lad->impUse, 0x00, sizeof(lad->impUse));
        adsize = sizeof(struct long_ad);
        break;
    default:
        return;
    }

    if (epos->bh) {
        if (!UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_STRICT) ||
            UDF_SB(inode->i_sb)->s_udfrev >= 0x0201) {
            struct allocExtDesc *aed =
                (struct allocExtDesc *)epos->bh->b_data;
            udf_update_tag(epos->bh->b_data,
                       le32_to_cpu(aed->lengthAllocDescs) +
                       sizeof(struct allocExtDesc));
        }
        mark_buffer_dirty_inode(epos->bh, inode);
    } else {
        mark_inode_dirty(inode);
    }

    if (inc)
        epos->offset += adsize;
}

int8_t udf_next_aext(struct inode *inode, struct extent_position *epos,
             struct kernel_lb_addr *eloc, uint32_t *elen, int inc)
{
    int8_t etype;

    while ((etype = udf_current_aext(inode, epos, eloc, elen, inc)) ==
           (EXT_NEXT_EXTENT_ALLOCDECS >> 30)) {
        int block;
        epos->block = *eloc;
        epos->offset = sizeof(struct allocExtDesc);
        brelse(epos->bh);
        block = udf_get_lb_pblock(inode->i_sb, &epos->block, 0);
        epos->bh = udf_tread(inode->i_sb, block);
        if (!epos->bh) {
            udf_debug("reading block %d failed!\n", block);
            return -1;
        }
    }

    return etype;
}

int8_t udf_current_aext(struct inode *inode, struct extent_position *epos,
            struct kernel_lb_addr *eloc, uint32_t *elen, int inc)
{
    int alen;
    int8_t etype;
    uint8_t *ptr;
    struct short_ad *sad;
    struct long_ad *lad;
    struct udf_inode_info *iinfo = UDF_I(inode);

    if (!epos->bh) {
        if (!epos->offset)
            epos->offset = udf_file_entry_alloc_offset(inode);
        ptr = iinfo->i_ext.i_data + epos->offset -
            udf_file_entry_alloc_offset(inode) +
            iinfo->i_lenEAttr;
        alen = udf_file_entry_alloc_offset(inode) +
                            iinfo->i_lenAlloc;
    } else {
        if (!epos->offset)
            epos->offset = sizeof(struct allocExtDesc);
        ptr = epos->bh->b_data + epos->offset;
        alen = sizeof(struct allocExtDesc) +
            le32_to_cpu(((struct allocExtDesc *)epos->bh->b_data)->
                            lengthAllocDescs);
    }

    switch (iinfo->i_alloc_type) {
    case ICBTAG_FLAG_AD_SHORT:
        sad = udf_get_fileshortad(ptr, alen, &epos->offset, inc);
        if (!sad)
            return -1;
        etype = le32_to_cpu(sad->extLength) >> 30;
        eloc->logicalBlockNum = le32_to_cpu(sad->extPosition);
        eloc->partitionReferenceNum =
                iinfo->i_location.partitionReferenceNum;
        *elen = le32_to_cpu(sad->extLength) & UDF_EXTENT_LENGTH_MASK;
        break;
    case ICBTAG_FLAG_AD_LONG:
        lad = udf_get_filelongad(ptr, alen, &epos->offset, inc);
        if (!lad)
            return -1;
        etype = le32_to_cpu(lad->extLength) >> 30;
        *eloc = lelb_to_cpu(lad->extLocation);
        *elen = le32_to_cpu(lad->extLength) & UDF_EXTENT_LENGTH_MASK;
        break;
    default:
        udf_debug("alloc_type = %d unsupported\n", iinfo->i_alloc_type);
        return -1;
    }

    return etype;
}

static int8_t udf_insert_aext(struct inode *inode, struct extent_position epos,
                  struct kernel_lb_addr neloc, uint32_t nelen)
{
    struct kernel_lb_addr oeloc;
    uint32_t oelen;
    int8_t etype;

    if (epos.bh)
        get_bh(epos.bh);

    while ((etype = udf_next_aext(inode, &epos, &oeloc, &oelen, 0)) != -1) {
        udf_write_aext(inode, &epos, &neloc, nelen, 1);
        neloc = oeloc;
        nelen = (etype << 30) | oelen;
    }
    udf_add_aext(inode, &epos, &neloc, nelen, 1);
    brelse(epos.bh);

    return (nelen >> 30);
}

int8_t udf_delete_aext(struct inode *inode, struct extent_position epos,
               struct kernel_lb_addr eloc, uint32_t elen)
{
    struct extent_position oepos;
    int adsize;
    int8_t etype;
    struct allocExtDesc *aed;
    struct udf_inode_info *iinfo;

    if (epos.bh) {
        get_bh(epos.bh);
        get_bh(epos.bh);
    }

    iinfo = UDF_I(inode);
    if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
        adsize = sizeof(struct short_ad);
    else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
        adsize = sizeof(struct long_ad);
    else
        adsize = 0;

    oepos = epos;
    if (udf_next_aext(inode, &epos, &eloc, &elen, 1) == -1)
        return -1;

    while ((etype = udf_next_aext(inode, &epos, &eloc, &elen, 1)) != -1) {
        udf_write_aext(inode, &oepos, &eloc, (etype << 30) | elen, 1);
        if (oepos.bh != epos.bh) {
            oepos.block = epos.block;
            brelse(oepos.bh);
            get_bh(epos.bh);
            oepos.bh = epos.bh;
            oepos.offset = epos.offset - adsize;
        }
    }
    memset(&eloc, 0x00, sizeof(struct kernel_lb_addr));
    elen = 0;

    if (epos.bh != oepos.bh) {
        udf_free_blocks(inode->i_sb, inode, &epos.block, 0, 1);
        udf_write_aext(inode, &oepos, &eloc, elen, 1);
        udf_write_aext(inode, &oepos, &eloc, elen, 1);
        if (!oepos.bh) {
            iinfo->i_lenAlloc -= (adsize * 2);
            mark_inode_dirty(inode);
        } else {
            aed = (struct allocExtDesc *)oepos.bh->b_data;
            le32_add_cpu(&aed->lengthAllocDescs, -(2 * adsize));
            if (!UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_STRICT) ||
                UDF_SB(inode->i_sb)->s_udfrev >= 0x0201)
                udf_update_tag(oepos.bh->b_data,
                        oepos.offset - (2 * adsize));
            else
                udf_update_tag(oepos.bh->b_data,
                        sizeof(struct allocExtDesc));
            mark_buffer_dirty_inode(oepos.bh, inode);
        }
    } else {
        udf_write_aext(inode, &oepos, &eloc, elen, 1);
        if (!oepos.bh) {
            iinfo->i_lenAlloc -= adsize;
            mark_inode_dirty(inode);
        } else {
            aed = (struct allocExtDesc *)oepos.bh->b_data;
            le32_add_cpu(&aed->lengthAllocDescs, -adsize);
            if (!UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_STRICT) ||
                UDF_SB(inode->i_sb)->s_udfrev >= 0x0201)
                udf_update_tag(oepos.bh->b_data,
                        epos.offset - adsize);
            else
                udf_update_tag(oepos.bh->b_data,
                        sizeof(struct allocExtDesc));
            mark_buffer_dirty_inode(oepos.bh, inode);
        }
    }

    brelse(epos.bh);
    brelse(oepos.bh);

    return (elen >> 30);
}

int8_t inode_bmap(struct inode *inode, sector_t block,
          struct extent_position *pos, struct kernel_lb_addr *eloc,
          uint32_t *elen, sector_t *offset)
{
    unsigned char blocksize_bits = inode->i_sb->s_blocksize_bits;
    loff_t lbcount = 0, bcount =
        (loff_t) block << blocksize_bits;
    int8_t etype;
    struct udf_inode_info *iinfo;

    iinfo = UDF_I(inode);
    pos->offset = 0;
    pos->block = iinfo->i_location;
    pos->bh = NULL;
    *elen = 0;

    do {
        etype = udf_next_aext(inode, pos, eloc, elen, 1);
        if (etype == -1) {
            *offset = (bcount - lbcount) >> blocksize_bits;
            iinfo->i_lenExtents = lbcount;
            return -1;
        }
        lbcount += *elen;
    } while (lbcount <= bcount);

    *offset = (bcount + *elen - lbcount) >> blocksize_bits;

    return etype;
}

long udf_block_map(struct inode *inode, sector_t block)
{
    struct kernel_lb_addr eloc;
    uint32_t elen;
    sector_t offset;
    struct extent_position epos = {};
    int ret;

    down_read(&UDF_I(inode)->i_data_sem);

    if (inode_bmap(inode, block, &epos, &eloc, &elen, &offset) ==
                        (EXT_RECORDED_ALLOCATED >> 30))
        ret = udf_get_lb_pblock(inode->i_sb, &eloc, offset);
    else
        ret = 0;

    up_read(&UDF_I(inode)->i_data_sem);
    brelse(epos.bh);

    if (UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_VARCONV))
        return udf_fixed_to_variable(ret);
    else
        return ret;
}