// SPDX-License-Identifier: GPL-2.0-only
/*
 * inode.c
 *
 * PURPOSE
 *  Inode handling routines for the OSTA-UDF(tm) filesystem.
 *
 * COPYRIGHT
 *  (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/writeback.h>
#include <linux/slab.h>
#include <linux/crc-itu-t.h>
#include <linux/mpage.h>
#include <linux/uio.h>
#include <linux/bio.h>

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

#define EXTENT_MERGE_SIZE 5

#define FE_MAPPED_PERMS (FE_PERM_U_READ | FE_PERM_U_WRITE | FE_PERM_U_EXEC | \
                         FE_PERM_G_READ | FE_PERM_G_WRITE | FE_PERM_G_EXEC | \
                         FE_PERM_O_READ | FE_PERM_O_WRITE | FE_PERM_O_EXEC)

#define FE_DELETE_PERMS (FE_PERM_U_DELETE | FE_PERM_G_DELETE | \
                         FE_PERM_O_DELETE)

struct udf_map_rq;

static umode_t udf_convert_permissions(struct fileEntry *);
static int udf_update_inode(struct inode *, int);
static int udf_sync_inode(struct inode *inode);
static int udf_alloc_i_data(struct inode *inode, size_t size);
static int inode_getblk(struct inode *inode, struct udf_map_rq *map);
static int udf_insert_aext(struct inode *, struct extent_position,
                           struct kernel_lb_addr, uint32_t);
static void udf_split_extents(struct inode *, int *, int, udf_pblk_t,
                              struct kernel_long_ad *, int *);
static void udf_prealloc_extents(struct inode *, int, int,
                                 struct kernel_long_ad *, int *);
static void udf_merge_extents(struct inode *, struct kernel_long_ad *, int *);
static int udf_update_extents(struct inode *, struct kernel_long_ad *, int,
                              int, struct extent_position *);
static int udf_get_block_wb(struct inode *inode, sector_t block,
                            struct buffer_head *bh_result, int create);

static void __udf_clear_extent_cache(struct inode *inode)
{
        struct udf_inode_info *iinfo = UDF_I(inode);

        if (iinfo->cached_extent.lstart != -1) {
                brelse(iinfo->cached_extent.epos.bh);
                iinfo->cached_extent.lstart = -1;
        }
}

/* Invalidate extent cache */
static void udf_clear_extent_cache(struct inode *inode)
{
        struct udf_inode_info *iinfo = UDF_I(inode);

        spin_lock(&iinfo->i_extent_cache_lock);
        __udf_clear_extent_cache(inode);
        spin_unlock(&iinfo->i_extent_cache_lock);
}

/* Return contents of extent cache */
static int udf_read_extent_cache(struct inode *inode, loff_t bcount,
                                 loff_t *lbcount, struct extent_position *pos)
{
        struct udf_inode_info *iinfo = UDF_I(inode);
        int ret = 0;

        spin_lock(&iinfo->i_extent_cache_lock);
        if ((iinfo->cached_extent.lstart <= bcount) &&
            (iinfo->cached_extent.lstart != -1)) {
                /* Cache hit */
                *lbcount = iinfo->cached_extent.lstart;
                memcpy(pos, &iinfo->cached_extent.epos,
                       sizeof(struct extent_position));
                if (pos->bh)
                        get_bh(pos->bh);
                ret = 1;
        }
        spin_unlock(&iinfo->i_extent_cache_lock);
        return ret;
}

/* Add extent to extent cache */
static void udf_update_extent_cache(struct inode *inode, loff_t estart,
                                    struct extent_position *pos)
{
        struct udf_inode_info *iinfo = UDF_I(inode);

        spin_lock(&iinfo->i_extent_cache_lock);
        /* Invalidate previously cached extent */
        __udf_clear_extent_cache(inode);
        if (pos->bh)
                get_bh(pos->bh);
        memcpy(&iinfo->cached_extent.epos, pos, sizeof(*pos));
        iinfo->cached_extent.lstart = estart;
        switch (iinfo->i_alloc_type) {
        case ICBTAG_FLAG_AD_SHORT:
                iinfo->cached_extent.epos.offset -= sizeof(struct short_ad);
                break;
        case ICBTAG_FLAG_AD_LONG:
                iinfo->cached_extent.epos.offset -= sizeof(struct long_ad);
                break;
        }
        spin_unlock(&iinfo->i_extent_cache_lock);
}

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

        if (!is_bad_inode(inode)) {
                if (!inode->i_nlink) {
                        want_delete = 1;
                        udf_setsize(inode, 0);
                        udf_update_inode(inode, IS_SYNC(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);
                }
        }
        truncate_inode_pages_final(&inode->i_data);
        invalidate_inode_buffers(inode);
        clear_inode(inode);
        kfree(iinfo->i_data);
        iinfo->i_data = NULL;
        udf_clear_extent_cache(inode);
        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, isize);
                if (iinfo->i_alloc_type != ICBTAG_FLAG_AD_IN_ICB) {
                        down_write(&iinfo->i_data_sem);
                        udf_clear_extent_cache(inode);
                        udf_truncate_extents(inode);
                        up_write(&iinfo->i_data_sem);
                }
        }
}

static int udf_handle_page_wb(struct folio *folio,
                              struct writeback_control *wbc)
{
        struct inode *inode = folio->mapping->host;
        struct udf_inode_info *iinfo = UDF_I(inode);

        /*
         * Inodes in the normal format are handled by the generic code. This
         * check is race-free as the folio lock protects us from inode type
         * conversion.
         */
        if (iinfo->i_alloc_type != ICBTAG_FLAG_AD_IN_ICB)
                return 1;

        memcpy_from_file_folio(iinfo->i_data + iinfo->i_lenEAttr, folio,
                                0, i_size_read(inode));
        folio_unlock(folio);
        mark_inode_dirty(inode);
        return 0;
}

static int udf_writepages(struct address_space *mapping,
                          struct writeback_control *wbc)
{
        return __mpage_writepages(mapping, wbc, udf_get_block_wb,
                                  udf_handle_page_wb);
}

static void udf_adinicb_read_folio(struct folio *folio)
{
        struct inode *inode = folio->mapping->host;
        struct udf_inode_info *iinfo = UDF_I(inode);
        loff_t isize = i_size_read(inode);

        folio_fill_tail(folio, 0, iinfo->i_data + iinfo->i_lenEAttr, isize);
        folio_mark_uptodate(folio);
}

static int udf_read_folio(struct file *file, struct folio *folio)
{
        struct udf_inode_info *iinfo = UDF_I(file_inode(file));

        if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
                udf_adinicb_read_folio(folio);
                folio_unlock(folio);
                return 0;
        }
        return mpage_read_folio(folio, udf_get_block);
}

static void udf_readahead(struct readahead_control *rac)
{
        struct udf_inode_info *iinfo = UDF_I(rac->mapping->host);

        /*
         * No readahead needed for in-ICB files and udf_get_block() would get
         * confused for such file anyway.
         */
        if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB)
                return;

        mpage_readahead(rac, udf_get_block);
}

static int udf_write_begin(const struct kiocb *iocb,
                           struct address_space *mapping,
                           loff_t pos, unsigned len,
                           struct folio **foliop, void **fsdata)
{
        struct file *file = iocb->ki_filp;
        struct udf_inode_info *iinfo = UDF_I(file_inode(file));
        struct folio *folio;
        int ret;

        if (iinfo->i_alloc_type != ICBTAG_FLAG_AD_IN_ICB) {
                ret = block_write_begin(mapping, pos, len, foliop,
                                        udf_get_block);
                if (unlikely(ret))
                        udf_write_failed(mapping, pos + len);
                return ret;
        }
        if (WARN_ON_ONCE(pos >= PAGE_SIZE))
                return -EIO;
        folio = __filemap_get_folio(mapping, 0, FGP_WRITEBEGIN,
                        mapping_gfp_mask(mapping));
        if (IS_ERR(folio))
                return PTR_ERR(folio);
        *foliop = folio;
        if (!folio_test_uptodate(folio))
                udf_adinicb_read_folio(folio);
        return 0;
}

static int udf_write_end(const struct kiocb *iocb,
                         struct address_space *mapping,
                         loff_t pos, unsigned len, unsigned copied,
                         struct folio *folio, void *fsdata)
{
        struct inode *inode = file_inode(iocb->ki_filp);
        loff_t last_pos;

        if (UDF_I(inode)->i_alloc_type != ICBTAG_FLAG_AD_IN_ICB)
                return generic_write_end(iocb, mapping, pos, len, copied, folio,
                                         fsdata);
        last_pos = pos + copied;
        if (last_pos > inode->i_size)
                i_size_write(inode, last_pos);
        folio_mark_dirty(folio);
        folio_unlock(folio);
        folio_put(folio);

        return copied;
}

static ssize_t udf_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
{
        struct file *file = iocb->ki_filp;
        struct address_space *mapping = file->f_mapping;
        struct inode *inode = mapping->host;
        size_t count = iov_iter_count(iter);
        ssize_t ret;

        /* Fallback to buffered IO for in-ICB files */
        if (UDF_I(inode)->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB)
                return 0;
        ret = blockdev_direct_IO(iocb, inode, iter, udf_get_block);
        if (unlikely(ret < 0 && iov_iter_rw(iter) == WRITE))
                udf_write_failed(mapping, iocb->ki_pos + count);
        return ret;
}

static sector_t udf_bmap(struct address_space *mapping, sector_t block)
{
        struct udf_inode_info *iinfo = UDF_I(mapping->host);

        if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB)
                return -EINVAL;
        return generic_block_bmap(mapping, block, udf_get_block);
}

const struct address_space_operations udf_aops = {
        .dirty_folio    = block_dirty_folio,
        .invalidate_folio = block_invalidate_folio,
        .read_folio     = udf_read_folio,
        .readahead      = udf_readahead,
        .writepages     = udf_writepages,
        .write_begin    = udf_write_begin,
        .write_end      = udf_write_end,
        .direct_IO      = udf_direct_IO,
        .bmap           = udf_bmap,
        .migrate_folio  = buffer_migrate_folio,
};

/*
 * Expand file stored in ICB to a normal one-block-file
 *
 * This function requires i_mutex held
 */
int udf_expand_file_adinicb(struct inode *inode)
{
        struct folio *folio;
        struct udf_inode_info *iinfo = UDF_I(inode);
        int err;

        WARN_ON_ONCE(!inode_is_locked(inode));
        if (!iinfo->i_lenAlloc) {
                down_write(&iinfo->i_data_sem);
                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;
                up_write(&iinfo->i_data_sem);
                mark_inode_dirty(inode);
                return 0;
        }

        folio = __filemap_get_folio(inode->i_mapping, 0,
                        FGP_LOCK | FGP_ACCESSED | FGP_CREAT, GFP_KERNEL);
        if (IS_ERR(folio))
                return PTR_ERR(folio);

        if (!folio_test_uptodate(folio))
                udf_adinicb_read_folio(folio);
        down_write(&iinfo->i_data_sem);
        memset(iinfo->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;
        folio_mark_dirty(folio);
        folio_unlock(folio);
        up_write(&iinfo->i_data_sem);
        err = filemap_fdatawrite(inode->i_mapping);
        if (err) {
                /* Restore everything back so that we don't lose data... */
                folio_lock(folio);
                down_write(&iinfo->i_data_sem);
                memcpy_from_folio(iinfo->i_data + iinfo->i_lenEAttr,
                                folio, 0, inode->i_size);
                folio_unlock(folio);
                iinfo->i_alloc_type = ICBTAG_FLAG_AD_IN_ICB;
                iinfo->i_lenAlloc = inode->i_size;
                up_write(&iinfo->i_data_sem);
        }
        folio_put(folio);
        mark_inode_dirty(inode);

        return err;
}

#define UDF_MAP_CREATE          0x01    /* Mapping can allocate new blocks */
#define UDF_MAP_NOPREALLOC      0x02    /* Do not preallocate blocks */

#define UDF_BLK_MAPPED  0x01    /* Block was successfully mapped */
#define UDF_BLK_NEW     0x02    /* Block was freshly allocated */

struct udf_map_rq {
        sector_t lblk;
        udf_pblk_t pblk;
        int iflags;             /* UDF_MAP_ flags determining behavior */
        int oflags;             /* UDF_BLK_ flags reporting results */
};

static int udf_map_block(struct inode *inode, struct udf_map_rq *map)
{
        int ret;
        struct udf_inode_info *iinfo = UDF_I(inode);

        if (WARN_ON_ONCE(iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB))
                return -EFSCORRUPTED;

        map->oflags = 0;
        if (!(map->iflags & UDF_MAP_CREATE)) {
                struct kernel_lb_addr eloc;
                uint32_t elen;
                sector_t offset;
                struct extent_position epos = {};
                int8_t etype;

                down_read(&iinfo->i_data_sem);
                ret = inode_bmap(inode, map->lblk, &epos, &eloc, &elen, &offset,
                                 &etype);
                if (ret < 0)
                        goto out_read;
                if (ret > 0 && etype == (EXT_RECORDED_ALLOCATED >> 30)) {
                        map->pblk = udf_get_lb_pblock(inode->i_sb, &eloc,
                                                        offset);
                        map->oflags |= UDF_BLK_MAPPED;
                        ret = 0;
                }
out_read:
                up_read(&iinfo->i_data_sem);
                brelse(epos.bh);

                return ret;
        }

        down_write(&iinfo->i_data_sem);
        /*
         * Block beyond EOF and prealloc extents? Just discard preallocation
         * as it is not useful and complicates things.
         */
        if (((loff_t)map->lblk) << inode->i_blkbits >= iinfo->i_lenExtents)
                udf_discard_prealloc(inode);
        udf_clear_extent_cache(inode);
        ret = inode_getblk(inode, map);
        up_write(&iinfo->i_data_sem);
        return ret;
}

static int __udf_get_block(struct inode *inode, sector_t block,
                           struct buffer_head *bh_result, int flags)
{
        int err;
        struct udf_map_rq map = {
                .lblk = block,
                .iflags = flags,
        };

        err = udf_map_block(inode, &map);
        if (err < 0)
                return err;
        if (map.oflags & UDF_BLK_MAPPED) {
                map_bh(bh_result, inode->i_sb, map.pblk);
                if (map.oflags & UDF_BLK_NEW)
                        set_buffer_new(bh_result);
        }
        return 0;
}

int udf_get_block(struct inode *inode, sector_t block,
                  struct buffer_head *bh_result, int create)
{
        int flags = create ? UDF_MAP_CREATE : 0;

        /*
         * 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))
                flags |= UDF_MAP_NOPREALLOC;
        return __udf_get_block(inode, block, bh_result, flags);
}

/*
 * We shouldn't be allocating blocks on page writeback since we allocate them
 * on page fault. We can spot dirty buffers without allocated blocks though
 * when truncate expands file. These however don't have valid data so we can
 * safely ignore them. So never allocate blocks from page writeback.
 */
static int udf_get_block_wb(struct inode *inode, sector_t block,
                            struct buffer_head *bh_result, int create)
{
        return __udf_get_block(inode, block, bh_result, 0);
}

/* Extend the file with new blocks totaling 'new_block_bytes',
 * 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,
                              loff_t new_block_bytes)
{
        uint32_t add;
        int count = 0, fake = !(last_ext->extLength & UDF_EXTENT_LENGTH_MASK);
        struct super_block *sb = inode->i_sb;
        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 (!new_block_bytes && 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);
        }

        add = 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);
                if (add > new_block_bytes)
                        add = new_block_bytes;
                new_block_bytes -= add;
                last_ext->extLength += add;
        }

        if (fake) {
                err = udf_add_aext(inode, last_pos, &last_ext->extLocation,
                                   last_ext->extLength, 1);
                if (err < 0)
                        goto out_err;
                count++;
        } else {
                struct kernel_lb_addr tmploc;
                uint32_t tmplen;
                int8_t tmptype;

                udf_write_aext(inode, last_pos, &last_ext->extLocation,
                                last_ext->extLength, 1);

                /*
                 * We've rewritten the last extent. If we are going to add
                 * more extents, we may need to enter possible following
                 * empty indirect extent.
                 */
                if (new_block_bytes) {
                        err = udf_next_aext(inode, last_pos, &tmploc, &tmplen,
                                            &tmptype, 0);
                        if (err < 0)
                                goto out_err;
                }
        }
        iinfo->i_lenExtents += add;

        /* Managed to do everything necessary? */
        if (!new_block_bytes)
                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;
        last_ext->extLength = EXT_NOT_RECORDED_NOT_ALLOCATED | add;

        /* Create enough extents to cover the whole hole */
        while (new_block_bytes > add) {
                new_block_bytes -= add;
                err = udf_add_aext(inode, last_pos, &last_ext->extLocation,
                                   last_ext->extLength, 1);
                if (err)
                        goto out_err;
                iinfo->i_lenExtents += add;
                count++;
        }
        if (new_block_bytes) {
                last_ext->extLength = EXT_NOT_RECORDED_NOT_ALLOCATED |
                        new_block_bytes;
                err = udf_add_aext(inode, last_pos, &last_ext->extLocation,
                                   last_ext->extLength, 1);
                if (err)
                        goto out_err;
                iinfo->i_lenExtents += new_block_bytes;
                count++;
        }

out:
        /* 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;
out_err:
        /* Remove extents we've created so far */
        udf_clear_extent_cache(inode);
        udf_truncate_extents(inode);
        return err;
}

/* Extend the final block of the file to final_block_len bytes */
static void udf_do_extend_final_block(struct inode *inode,
                                      struct extent_position *last_pos,
                                      struct kernel_long_ad *last_ext,
                                      uint32_t new_elen)
{
        uint32_t added_bytes;

        /*
         * Extent already large enough? It may be already rounded up to block
         * size...
         */
        if (new_elen <= (last_ext->extLength & UDF_EXTENT_LENGTH_MASK))
                return;
        added_bytes = new_elen - (last_ext->extLength & UDF_EXTENT_LENGTH_MASK);
        last_ext->extLength += added_bytes;
        UDF_I(inode)->i_lenExtents += added_bytes;

        udf_write_aext(inode, last_pos, &last_ext->extLocation,
                        last_ext->extLength, 1);
}

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;
        loff_t new_elen;
        int adsize;
        struct udf_inode_info *iinfo = UDF_I(inode);
        struct kernel_long_ad extent;
        int err = 0;
        bool within_last_ext;

        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();

        down_write(&iinfo->i_data_sem);
        /*
         * When creating hole in file, just don't bother with preserving
         * preallocation. It likely won't be very useful anyway.
         */
        udf_discard_prealloc(inode);

        err = inode_bmap(inode, first_block, &epos, &eloc, &elen, &offset, &etype);
        if (err < 0)
                goto out;
        within_last_ext = (err == 1);
        /* We don't expect extents past EOF... */
        WARN_ON_ONCE(within_last_ext &&
                     elen > ((loff_t)offset + 1) << inode->i_blkbits);

        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;
                err = udf_next_aext(inode, &epos, &extent.extLocation,
                                    &extent.extLength, &etype, 0);
                if (err <= 0)
                        goto out;
                extent.extLength |= etype << 30;
        }

        new_elen = ((loff_t)offset << inode->i_blkbits) |
                                        (newsize & (sb->s_blocksize - 1));

        /* File has extent covering the new size (could happen when extending
         * inside a block)?
         */
        if (within_last_ext) {
                /* Extending file within the last file block */
                udf_do_extend_final_block(inode, &epos, &extent, new_elen);
        } else {
                err = udf_do_extend_file(inode, &epos, &extent, new_elen);
        }

        if (err < 0)
                goto out;
        err = 0;
out:
        brelse(epos.bh);
        up_write(&iinfo->i_data_sem);
        return err;
}

static int inode_getblk(struct inode *inode, struct udf_map_rq *map)
{
        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;
        udf_pblk_t newblocknum;
        sector_t offset = 0;
        int8_t etype, tmpetype;
        struct udf_inode_info *iinfo = UDF_I(inode);
        udf_pblk_t goal = 0, pgoal = iinfo->i_location.logicalBlockNum;
        int lastblock = 0;
        bool isBeyondEOF = false;
        int ret = 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)map->lblk << 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;

                ret = udf_next_aext(inode, &next_epos, &eloc, &elen, &etype, 1);
                if (ret < 0) {
                        goto out_free;
                } else if (ret == 0) {
                        isBeyondEOF = true;
                        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
         */
        ret = udf_next_aext(inode, &prev_epos, &tmpeloc, &tmpelen, &tmpetype, 0);
        if (ret < 0)
                goto out_free;
        ret = udf_next_aext(inode, &cur_epos, &tmpeloc, &tmpelen, &tmpetype, 0);
        if (ret < 0)
                goto out_free;

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

        if (!isBeyondEOF && 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));
                        iinfo->i_lenExtents =
                                ALIGN(iinfo->i_lenExtents,
                                      inode->i_sb->s_blocksize);
                        udf_write_aext(inode, &cur_epos, &eloc, elen, 1);
                }
                map->oflags = UDF_BLK_MAPPED;
                map->pblk = udf_get_lb_pblock(inode->i_sb, &eloc, offset);
                ret = 0;
                goto out_free;
        }

        /* Are we beyond EOF and preallocated extent? */
        if (isBeyondEOF) {
                loff_t hole_len;

                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 */
                hole_len = (loff_t)offset << inode->i_blkbits;
                ret = udf_do_extend_file(inode, &prev_epos, laarr, hole_len);
                if (ret < 0)
                        goto out_free;
                c = 0;
                offset = 0;
                count += ret;
                /*
                 * 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 = 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 */
                ret = udf_next_aext(inode, &next_epos, &eloc, &elen, &etype, 0);
                if (ret > 0) {
                        laarr[c + 1].extLength = (etype << 30) | elen;
                        laarr[c + 1].extLocation = eloc;
                        count++;
                        startnum++;
                        endnum++;
                } else if (ret == 0)
                        lastblock = 1;
                else
                        goto out_free;
        }

        /* 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 == map->lblk)
                        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, &ret);
                if (!newblocknum)
                        goto out_free;
                if (isBeyondEOF)
                        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);

        if (!(map->iflags & UDF_MAP_NOPREALLOC))
                udf_prealloc_extents(inode, c, lastblock, laarr, &endnum);

        /* 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 */
        ret = udf_update_extents(inode, laarr, startnum, endnum, &prev_epos);
        if (ret < 0)
                goto out_free;

        map->pblk = udf_get_pblock(inode->i_sb, newblocknum,
                                iinfo->i_location.partitionReferenceNum, 0);
        if (!map->pblk) {
                ret = -EFSCORRUPTED;
                goto out_free;
        }
        map->oflags = UDF_BLK_NEW | UDF_BLK_MAPPED;
        iinfo->i_next_alloc_block = map->lblk + 1;
        iinfo->i_next_alloc_goal = newblocknum + 1;
        inode_set_ctime_current(inode);

        if (IS_SYNC(inode))
                udf_sync_inode(inode);
        else
                mark_inode_dirty(inode);
        ret = 0;
out_free:
        brelse(prev_epos.bh);
        brelse(cur_epos.bh);
        brelse(next_epos.bh);
        return ret;
}

static void udf_split_extents(struct inode *inode, int *c, int offset,
                               udf_pblk_t newblocknum,
                               struct kernel_long_ad *laarr, 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,
                                 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,
                              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) {
                                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 int udf_update_extents(struct inode *inode, struct kernel_long_ad *laarr,
                              int startnum, int endnum,
                              struct extent_position *epos)
{
        int start = 0, i;
        struct kernel_lb_addr tmploc;
        uint32_t tmplen;
        int8_t tmpetype;
        int err;

        if (startnum > endnum) {
                for (i = 0; i < (startnum - endnum); i++)
                        udf_delete_aext(inode, *epos);
        } else if (startnum < endnum) {
                for (i = 0; i < (endnum - startnum); i++) {
                        err = udf_insert_aext(inode, *epos,
                                              laarr[i].extLocation,
                                              laarr[i].extLength);
                        /*
                         * If we fail here, we are likely corrupting the extent
                         * list and leaking blocks. At least stop early to
                         * limit the damage.
                         */
                        if (err < 0)
                                return err;
                        err = udf_next_aext(inode, epos, &laarr[i].extLocation,
                                      &laarr[i].extLength, &tmpetype, 1);
                        if (err < 0)
                                return err;
                        start++;
                }
        }

        for (i = start; i < endnum; i++) {
                err = udf_next_aext(inode, epos, &tmploc, &tmplen, &tmpetype, 0);
                if (err < 0)
                        return err;

                udf_write_aext(inode, epos, &laarr[i].extLocation,
                               laarr[i].extLength, 1);
        }
        return 0;
}

struct buffer_head *udf_bread(struct inode *inode, udf_pblk_t block,
                              int create, int *err)
{
        struct buffer_head *bh = NULL;
        struct udf_map_rq map = {
                .lblk = block,
                .iflags = UDF_MAP_NOPREALLOC | (create ? UDF_MAP_CREATE : 0),
        };

        *err = udf_map_block(inode, &map);
        if (*err || !(map.oflags & UDF_BLK_MAPPED))
                return NULL;

        bh = sb_getblk(inode->i_sb, map.pblk);
        if (!bh) {
                *err = -ENOMEM;
                return NULL;
        }
        if (map.oflags & UDF_BLK_NEW) {
                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;
        }

        if (bh_read(bh, 0) >= 0)
                return bh;

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

int udf_setsize(struct inode *inode, loff_t newsize)
{
        int err = 0;
        struct udf_inode_info *iinfo;
        unsigned int bsize = i_blocksize(inode);

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

        iinfo = UDF_I(inode);
        if (newsize > inode->i_size) {
                if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
                        if (bsize >=
                            (udf_file_entry_alloc_offset(inode) + newsize)) {
                                down_write(&iinfo->i_data_sem);
                                iinfo->i_lenAlloc = newsize;
                                up_write(&iinfo->i_data_sem);
                                goto set_size;
                        }
                        err = udf_expand_file_adinicb(inode);
                        if (err)
                                return err;
                }
                err = udf_extend_file(inode, newsize);
                if (err)
                        return err;
set_size:
                truncate_setsize(inode, newsize);
        } else {
                if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
                        down_write(&iinfo->i_data_sem);
                        udf_clear_extent_cache(inode);
                        memset(iinfo->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;
                truncate_setsize(inode, newsize);
                down_write(&iinfo->i_data_sem);
                udf_clear_extent_cache(inode);
                err = udf_truncate_extents(inode);
                up_write(&iinfo->i_data_sem);
                if (err)
                        return err;
        }
update_time:
        inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
        if (IS_SYNC(inode))
                udf_sync_inode(inode);
        else
                mark_inode_dirty(inode);
        return err;
}

/*
 * Maximum length of linked list formed by ICB hierarchy. The chosen number is
 * arbitrary - just that we hopefully don't limit any real use of rewritten
 * inode on write-once media but avoid looping for too long on corrupted media.
 */
#define UDF_MAX_ICB_NESTING 1024

static int udf_read_inode(struct inode *inode, bool hidden_inode)
{
        struct buffer_head *bh = NULL;
        struct fileEntry *fe;
        struct extendedFileEntry *efe;
        uint16_t ident;
        struct udf_inode_info *iinfo = UDF_I(inode);
        struct udf_sb_info *sbi = UDF_SB(inode->i_sb);
        struct kernel_lb_addr *iloc = &iinfo->i_location;
        unsigned int link_count;
        unsigned int indirections = 0;
        int bs = inode->i_sb->s_blocksize;
        int ret = -EIO;
        uint32_t uid, gid;
        struct timespec64 ts;

reread:
        if (iloc->partitionReferenceNum >= sbi->s_partitions) {
                udf_debug("partition reference: %u > logical volume partitions: %u\n",
                          iloc->partitionReferenceNum, sbi->s_partitions);
                return -EIO;
        }

        if (iloc->logicalBlockNum >=
            sbi->s_partmaps[iloc->partitionReferenceNum].s_partition_len) {
                udf_debug("block=%u, partition=%u out of range\n",
                          iloc->logicalBlockNum, iloc->partitionReferenceNum);
                return -EIO;
        }

        /*
         * 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, iloc, 0, &ident);
        if (!bh) {
                udf_err(inode->i_sb, "(ino %lu) failed !bh\n", inode->i_ino);
                return -EIO;
        }

        if (ident != TAG_IDENT_FE && ident != TAG_IDENT_EFE &&
            ident != TAG_IDENT_USE) {
                udf_err(inode->i_sb, "(ino %lu) failed ident=%u\n",
                        inode->i_ino, ident);
                goto out;
        }

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

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

                ibh = udf_read_ptagged(inode->i_sb, iloc, 1, &ident);
                if (ident == TAG_IDENT_IE && ibh) {
                        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) {
                                brelse(ibh);
                                memcpy(&iinfo->i_location, &loc,
                                       sizeof(struct kernel_lb_addr));
                                if (++indirections > UDF_MAX_ICB_NESTING) {
                                        udf_err(inode->i_sb,
                                                "too many ICBs in ICB hierarchy"
                                                " (max %d supported)\n",
                                                UDF_MAX_ICB_NESTING);
                                        goto out;
                                }
                                brelse(bh);
                                goto reread;
                        }
                }
                brelse(ibh);
        } else if (fe->icbTag.strategyType != cpu_to_le16(4)) {
                udf_err(inode->i_sb, "unsupported strategy type: %u\n",
                        le16_to_cpu(fe->icbTag.strategyType));
                goto out;
        }
        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;
        if (iinfo->i_alloc_type != ICBTAG_FLAG_AD_SHORT &&
            iinfo->i_alloc_type != ICBTAG_FLAG_AD_LONG &&
            iinfo->i_alloc_type != ICBTAG_FLAG_AD_IN_ICB) {
                ret = -EIO;
                goto out;
        }
        iinfo->i_hidden = hidden_inode;
        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;
                ret = udf_alloc_i_data(inode, bs -
                                        sizeof(struct extendedFileEntry));
                if (ret)
                        goto out;
                memcpy(iinfo->i_data,
                       bh->b_data + sizeof(struct extendedFileEntry),
                       bs - sizeof(struct extendedFileEntry));
        } else if (fe->descTag.tagIdent == cpu_to_le16(TAG_IDENT_FE)) {
                iinfo->i_efe = 0;
                iinfo->i_use = 0;
                ret = udf_alloc_i_data(inode, bs - sizeof(struct fileEntry));
                if (ret)
                        goto out;
                memcpy(iinfo->i_data,
                       bh->b_data + sizeof(struct fileEntry),
                       bs - 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);
                ret = udf_alloc_i_data(inode, bs -
                                        sizeof(struct unallocSpaceEntry));
                if (ret)
                        goto out;
                memcpy(iinfo->i_data,
                       bh->b_data + sizeof(struct unallocSpaceEntry),
                       bs - sizeof(struct unallocSpaceEntry));
                return 0;
        }

        ret = -EIO;
        read_lock(&sbi->s_cred_lock);
        uid = le32_to_cpu(fe->uid);
        if (uid == UDF_INVALID_ID ||
            UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_UID_SET))
                inode->i_uid = sbi->s_uid;
        else
                i_uid_write(inode, uid);

        gid = le32_to_cpu(fe->gid);
        if (gid == UDF_INVALID_ID ||
            UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_GID_SET))
                inode->i_gid = sbi->s_gid;
        else
                i_gid_write(inode, 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;
        iinfo->i_extraPerms = le32_to_cpu(fe->permissions) & ~FE_MAPPED_PERMS;

        read_unlock(&sbi->s_cred_lock);

        link_count = le16_to_cpu(fe->fileLinkCount);
        if (!link_count) {
                if (!hidden_inode) {
                        ret = -ESTALE;
                        goto out;
                }
                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);

                udf_disk_stamp_to_time(&ts, fe->accessTime);
                inode_set_atime_to_ts(inode, ts);
                udf_disk_stamp_to_time(&ts, fe->modificationTime);
                inode_set_mtime_to_ts(inode, ts);
                udf_disk_stamp_to_time(&ts, fe->attrTime);
                inode_set_ctime_to_ts(inode, ts);

                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);
                iinfo->i_streamdir = 0;
                iinfo->i_lenStreams = 0;
        } else {
                inode->i_blocks = le64_to_cpu(efe->logicalBlocksRecorded) <<
                    (inode->i_sb->s_blocksize_bits - 9);

                udf_disk_stamp_to_time(&ts, efe->accessTime);
                inode_set_atime_to_ts(inode, ts);
                udf_disk_stamp_to_time(&ts, efe->modificationTime);
                inode_set_mtime_to_ts(inode, ts);
                udf_disk_stamp_to_time(&ts, efe->attrTime);
                inode_set_ctime_to_ts(inode, ts);
                udf_disk_stamp_to_time(&iinfo->i_crtime, efe->createTime);

                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);

                /* Named streams */
                iinfo->i_streamdir = (efe->streamDirectoryICB.extLength != 0);
                iinfo->i_locStreamdir =
                        lelb_to_cpu(efe->streamDirectoryICB.extLocation);
                iinfo->i_lenStreams = le64_to_cpu(efe->objectSize);
                if (iinfo->i_lenStreams >= inode->i_size)
                        iinfo->i_lenStreams -= inode->i_size;
                else
                        iinfo->i_lenStreams = 0;
        }
        inode->i_generation = iinfo->i_unique;

        /*
         * Sanity check length of allocation descriptors and extended attrs to
         * avoid integer overflows
         */
        if (iinfo->i_lenEAttr > bs || iinfo->i_lenAlloc > bs)
                goto out;
        /* Now do exact checks */
        if (udf_file_entry_alloc_offset(inode) + iinfo->i_lenAlloc > bs)
                goto out;
        /* Sanity checks for files in ICB so that we don't get confused later */
        if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
                /*
                 * For file in ICB data is stored in allocation descriptor
                 * so sizes should match
                 */
                if (iinfo->i_lenAlloc != inode->i_size)
                        goto out;
                /* File in ICB has to fit in there... */
                if (inode->i_size > bs - udf_file_entry_alloc_offset(inode))
                        goto out;
        }

        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:
                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_nohighmem(inode);
                inode->i_mode = S_IFLNK | 0777;
                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 %lu) failed unknown file type=%u\n",
                        inode->i_ino, fe->icbTag.fileType);
                goto out;
        }
        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
                        goto out;
        }
        ret = 0;
out:
        brelse(bh);
        return ret;
}

static int udf_alloc_i_data(struct inode *inode, size_t size)
{
        struct udf_inode_info *iinfo = UDF_I(inode);
        iinfo->i_data = kmalloc(size, GFP_KERNEL);
        if (!iinfo->i_data)
                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) & 0007) |
                ((permissions >> 2) & 0070) |
                ((permissions >> 4) & 0700) |
                ((flags & ICBTAG_FLAG_SETUID) ? S_ISUID : 0) |
                ((flags & ICBTAG_FLAG_SETGID) ? S_ISGID : 0) |
                ((flags & ICBTAG_FLAG_STICKY) ? S_ISVTX : 0);

        return mode;
}

void udf_update_extra_perms(struct inode *inode, umode_t mode)
{
        struct udf_inode_info *iinfo = UDF_I(inode);

        /*
         * UDF 2.01 sec. 3.3.3.3 Note 2:
         * In Unix, delete permission tracks write
         */
        iinfo->i_extraPerms &= ~FE_DELETE_PERMS;
        if (mode & 0200)
                iinfo->i_extraPerms |= FE_PERM_U_DELETE;
        if (mode & 0020)
                iinfo->i_extraPerms |= FE_PERM_G_DELETE;
        if (mode & 0002)
                iinfo->i_extraPerms |= FE_PERM_O_DELETE;
}

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 void udf_adjust_time(struct udf_inode_info *iinfo, struct timespec64 time)
{
        if (iinfo->i_crtime.tv_sec > time.tv_sec ||
            (iinfo->i_crtime.tv_sec == time.tv_sec &&
             iinfo->i_crtime.tv_nsec > time.tv_nsec))
                iinfo->i_crtime = time;
}

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

        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_data, inode->i_sb->s_blocksize -
                                        sizeof(struct unallocSpaceEntry));
                use->descTag.tagIdent = cpu_to_le16(TAG_IDENT_USE);
                crclen = sizeof(struct unallocSpaceEntry);

                goto finish;
        }

        if (UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_UID_FORGET))
                fe->uid = cpu_to_le32(UDF_INVALID_ID);
        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(UDF_INVALID_ID);
        else
                fe->gid = cpu_to_le32(i_gid_read(inode));

        udfperms = ((inode->i_mode & 0007)) |
                   ((inode->i_mode & 0070) << 2) |
                   ((inode->i_mode & 0700) << 4);

        udfperms |= iinfo->i_extraPerms;
        fe->permissions = cpu_to_le32(udfperms);

        if (S_ISDIR(inode->i_mode) && inode->i_nlink > 0)
                fe->fileLinkCount = cpu_to_le16(inode->i_nlink - 1);
        else {
                if (iinfo->i_hidden)
                        fe->fileLinkCount = cpu_to_le16(0);
                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(*eid));
                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_data,
                       inode->i_sb->s_blocksize - sizeof(struct fileEntry));
                fe->logicalBlocksRecorded = cpu_to_le64(lb_recorded);

                udf_time_to_disk_stamp(&fe->accessTime, inode_get_atime(inode));
                udf_time_to_disk_stamp(&fe->modificationTime, inode_get_mtime(inode));
                udf_time_to_disk_stamp(&fe->attrTime, inode_get_ctime(inode));
                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_data,
                       inode->i_sb->s_blocksize -
                                        sizeof(struct extendedFileEntry));
                efe->objectSize =
                        cpu_to_le64(inode->i_size + iinfo->i_lenStreams);
                efe->logicalBlocksRecorded = cpu_to_le64(lb_recorded);

                if (iinfo->i_streamdir) {
                        struct long_ad *icb_lad = &efe->streamDirectoryICB;

                        icb_lad->extLocation =
                                cpu_to_lelb(iinfo->i_locStreamdir);
                        icb_lad->extLength =
                                cpu_to_le32(inode->i_sb->s_blocksize);
                }

                udf_adjust_time(iinfo, inode_get_atime(inode));
                udf_adjust_time(iinfo, inode_get_mtime(inode));
                udf_adjust_time(iinfo, inode_get_ctime(inode));

                udf_time_to_disk_stamp(&efe->accessTime,
                                       inode_get_atime(inode));
                udf_time_to_disk_stamp(&efe->modificationTime,
                                       inode_get_mtime(inode));
                udf_time_to_disk_stamp(&efe->createTime, iinfo->i_crtime);
                udf_time_to_disk_stamp(&efe->attrTime, inode_get_ctime(inode));

                memset(&(efe->impIdent), 0, sizeof(efe->impIdent));
                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);
        }

finish:
        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 (iinfo->i_use)
                fe->icbTag.fileType = ICBTAG_FILE_TYPE_USE;
        else 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);

        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,
                         bool hidden_inode)
{
        unsigned long block = udf_get_lb_pblock(sb, ino, 0);
        struct inode *inode = iget_locked(sb, block);
        int err;

        if (!inode)
                return ERR_PTR(-ENOMEM);

        if (!(inode_state_read_once(inode) & I_NEW)) {
                if (UDF_I(inode)->i_hidden != hidden_inode) {
                        iput(inode);
                        return ERR_PTR(-EFSCORRUPTED);
                }
                return inode;
        }

        memcpy(&UDF_I(inode)->i_location, ino, sizeof(struct kernel_lb_addr));
        err = udf_read_inode(inode, hidden_inode);
        if (err < 0) {
                iget_failed(inode);
                return ERR_PTR(err);
        }
        unlock_new_inode(inode);

        return inode;
}

int udf_setup_indirect_aext(struct inode *inode, udf_pblk_t block,
                            struct extent_position *epos)
{
        struct super_block *sb = inode->i_sb;
        struct buffer_head *bh;
        struct allocExtDesc *aed;
        struct extent_position nepos;
        struct kernel_lb_addr neloc;
        int ver, adsize;
        int err = 0;

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

        neloc.logicalBlockNum = block;
        neloc.partitionReferenceNum = epos->block.partitionReferenceNum;

        bh = sb_getblk(sb, udf_get_lb_pblock(sb, &neloc, 0));
        if (!bh)
                return -EIO;
        lock_buffer(bh);
        memset(bh->b_data, 0x00, sb->s_blocksize);
        set_buffer_uptodate(bh);
        unlock_buffer(bh);
        mark_buffer_dirty_inode(bh, inode);

        aed = (struct allocExtDesc *)(bh->b_data);
        if (!UDF_QUERY_FLAG(sb, UDF_FLAG_STRICT)) {
                aed->previousAllocExtLocation =
                                cpu_to_le32(epos->block.logicalBlockNum);
        }
        aed->lengthAllocDescs = cpu_to_le32(0);
        if (UDF_SB(sb)->s_udfrev >= 0x0200)
                ver = 3;
        else
                ver = 2;
        udf_new_tag(bh->b_data, TAG_IDENT_AED, ver, 1, block,
                    sizeof(struct tag));

        nepos.block = neloc;
        nepos.offset = sizeof(struct allocExtDesc);
        nepos.bh = bh;

        /*
         * Do we have to copy current last extent to make space for indirect
         * one?
         */
        if (epos->offset + adsize > sb->s_blocksize) {
                struct kernel_lb_addr cp_loc;
                uint32_t cp_len;
                int8_t cp_type;

                epos->offset -= adsize;
                err = udf_current_aext(inode, epos, &cp_loc, &cp_len, &cp_type, 0);
                if (err <= 0)
                        goto err_out;
                cp_len |= ((uint32_t)cp_type) << 30;

                __udf_add_aext(inode, &nepos, &cp_loc, cp_len, 1);
                udf_write_aext(inode, epos, &nepos.block,
                               sb->s_blocksize | EXT_NEXT_EXTENT_ALLOCDESCS, 0);
        } else {
                __udf_add_aext(inode, epos, &nepos.block,
                               sb->s_blocksize | EXT_NEXT_EXTENT_ALLOCDESCS, 0);
        }

        brelse(epos->bh);
        *epos = nepos;

        return 0;
err_out:
        brelse(bh);
        return err;
}

/*
 * Append extent at the given position - should be the first free one in inode
 * / indirect extent. This function assumes there is enough space in the inode
 * or indirect extent. Use udf_add_aext() if you didn't check for this before.
 */
int __udf_add_aext(struct inode *inode, struct extent_position *epos,
                   struct kernel_lb_addr *eloc, uint32_t elen, int inc)
{
        struct udf_inode_info *iinfo = UDF_I(inode);
        struct allocExtDesc *aed;
        int adsize;

        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->bh) {
                WARN_ON(iinfo->i_lenAlloc !=
                        epos->offset - udf_file_entry_alloc_offset(inode));
        } else {
                aed = (struct allocExtDesc *)epos->bh->b_data;
                WARN_ON(le32_to_cpu(aed->lengthAllocDescs) !=
                        epos->offset - sizeof(struct allocExtDesc));
                WARN_ON(epos->offset + adsize > inode->i_sb->s_blocksize);
        }

        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;
}

/*
 * Append extent at given position - should be the first free one in inode
 * / indirect extent. Takes care of allocating and linking indirect blocks.
 */
int udf_add_aext(struct inode *inode, struct extent_position *epos,
                 struct kernel_lb_addr *eloc, uint32_t elen, int inc)
{
        int adsize;
        struct super_block *sb = inode->i_sb;

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

        if (epos->offset + (2 * adsize) > sb->s_blocksize) {
                int err;
                udf_pblk_t new_block;

                new_block = udf_new_block(sb, NULL,
                                          epos->block.partitionReferenceNum,
                                          epos->block.logicalBlockNum, &err);
                if (!new_block)
                        return -ENOSPC;

                err = udf_setup_indirect_aext(inode, new_block, epos);
                if (err)
                        return err;
        }

        return __udf_add_aext(inode, epos, eloc, elen, inc);
}

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_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;
}

/*
 * Only 1 indirect extent in a row really makes sense but allow upto 16 in case
 * someone does some weird stuff.
 */
#define UDF_MAX_INDIR_EXTS 16

/*
 * Returns 1 on success, -errno on error, 0 on hit EOF.
 */
int udf_next_aext(struct inode *inode, struct extent_position *epos,
                  struct kernel_lb_addr *eloc, uint32_t *elen, int8_t *etype,
                  int inc)
{
        unsigned int indirections = 0;
        int ret = 0;
        udf_pblk_t block;

        while (1) {
                ret = udf_current_aext(inode, epos, eloc, elen,
                                       etype, inc);
                if (ret <= 0)
                        return ret;
                if (*etype != (EXT_NEXT_EXTENT_ALLOCDESCS >> 30))
                        return ret;

                if (++indirections > UDF_MAX_INDIR_EXTS) {
                        udf_err(inode->i_sb,
                                "too many indirect extents in inode %lu\n",
                                inode->i_ino);
                        return -EFSCORRUPTED;
                }

                epos->block = *eloc;
                epos->offset = sizeof(struct allocExtDesc);
                brelse(epos->bh);
                block = udf_get_lb_pblock(inode->i_sb, &epos->block, 0);
                epos->bh = sb_bread(inode->i_sb, block);
                if (!epos->bh) {
                        udf_debug("reading block %u failed!\n", block);
                        return -EIO;
                }
        }
}

/*
 * Returns 1 on success, -errno on error, 0 on hit EOF.
 */
int udf_current_aext(struct inode *inode, struct extent_position *epos,
                     struct kernel_lb_addr *eloc, uint32_t *elen, int8_t *etype,
                     int inc)
{
        int alen;
        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_data + epos->offset -
                        udf_file_entry_alloc_offset(inode) +
                        iinfo->i_lenEAttr;
                alen = udf_file_entry_alloc_offset(inode) +
                                                        iinfo->i_lenAlloc;
        } else {
                struct allocExtDesc *header =
                        (struct allocExtDesc *)epos->bh->b_data;

                if (!epos->offset)
                        epos->offset = sizeof(struct allocExtDesc);
                ptr = epos->bh->b_data + epos->offset;
                if (check_add_overflow(sizeof(struct allocExtDesc),
                                le32_to_cpu(header->lengthAllocDescs), &alen))
                        return -1;

                if (alen > epos->bh->b_size)
                        return -1;
        }

        switch (iinfo->i_alloc_type) {
        case ICBTAG_FLAG_AD_SHORT:
                sad = udf_get_fileshortad(ptr, alen, &epos->offset, inc);
                if (!sad)
                        return 0;
                *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 0;
                *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 = %u unsupported\n", iinfo->i_alloc_type);
                return -EINVAL;
        }

        return 1;
}

static int 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;
        int ret;

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

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

        return ret;
}

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

        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, &etype, 1) <= 0)
                return -1;

        while (1) {
                ret = udf_next_aext(inode, &epos, &eloc, &elen, &etype, 1);
                if (ret < 0) {
                        brelse(epos.bh);
                        brelse(oepos.bh);
                        return -1;
                }
                if (ret == 0)
                        break;
                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);
}

/*
 * Returns 1 on success, -errno on error, 0 on hit EOF.
 */
int inode_bmap(struct inode *inode, sector_t block, struct extent_position *pos,
               struct kernel_lb_addr *eloc, uint32_t *elen, sector_t *offset,
               int8_t *etype)
{
        unsigned char blocksize_bits = inode->i_sb->s_blocksize_bits;
        loff_t lbcount = 0, bcount = (loff_t) block << blocksize_bits;
        struct udf_inode_info *iinfo;
        int err = 0;

        iinfo = UDF_I(inode);
        if (!udf_read_extent_cache(inode, bcount, &lbcount, pos)) {
                pos->offset = 0;
                pos->block = iinfo->i_location;
                pos->bh = NULL;
        }
        *elen = 0;
        do {
                err = udf_next_aext(inode, pos, eloc, elen, etype, 1);
                if (err <= 0) {
                        if (err == 0) {
                                *offset = (bcount - lbcount) >> blocksize_bits;
                                iinfo->i_lenExtents = lbcount;
                        }
                        return err;
                }
                lbcount += *elen;
        } while (lbcount <= bcount);
        /* update extent cache */
        udf_update_extent_cache(inode, lbcount - *elen, pos);
        *offset = (bcount + *elen - lbcount) >> blocksize_bits;

        return 1;
}