Linux-2.6.12-rc2

[mirror_ubuntu-artful-kernel.git] / fs / udf / namei.c

/*
 * namei.c
 *
 * PURPOSE
 *      Inode name handling routines for the OSTA-UDF(tm) filesystem.
 *
 * CONTACTS
 *      E-mail regarding any portion of the Linux UDF file system should be
 *      directed to the development team mailing list (run by majordomo):
 *              linux_udf@hpesjro.fc.hp.com
 *
 * COPYRIGHT
 *      This file is distributed under the terms of the GNU General Public
 *      License (GPL). Copies of the GPL can be obtained from:
 *              ftp://prep.ai.mit.edu/pub/gnu/GPL
 *      Each contributing author retains all rights to their own work.
 *
 *  (C) 1998-2004 Ben Fennema
 *  (C) 1999-2000 Stelias Computing Inc
 *
 * HISTORY
 *
 *  12/12/98 blf  Created. Split out the lookup code from dir.c
 *  04/19/99 blf  link, mknod, symlink support
 */

#include "udfdecl.h"

#include "udf_i.h"
#include "udf_sb.h"
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/quotaops.h>
#include <linux/smp_lock.h>
#include <linux/buffer_head.h>

static inline int udf_match(int len1, const char *name1, int len2, const char *name2)
{
        if (len1 != len2)
                return 0;
        return !memcmp(name1, name2, len1);
}

int udf_write_fi(struct inode *inode, struct fileIdentDesc *cfi,
        struct fileIdentDesc *sfi, struct udf_fileident_bh *fibh,
        uint8_t *impuse, uint8_t *fileident)
{
        uint16_t crclen = fibh->eoffset - fibh->soffset - sizeof(tag);
        uint16_t crc;
        uint8_t checksum = 0;
        int i;
        int offset;
        uint16_t liu = le16_to_cpu(cfi->lengthOfImpUse);
        uint8_t lfi = cfi->lengthFileIdent;
        int padlen = fibh->eoffset - fibh->soffset - liu - lfi -
                sizeof(struct fileIdentDesc);
        int adinicb = 0;

        if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_IN_ICB)
                adinicb = 1;

        offset = fibh->soffset + sizeof(struct fileIdentDesc);

        if (impuse)
        {
                if (adinicb || (offset + liu < 0))
                        memcpy((uint8_t *)sfi->impUse, impuse, liu);
                else if (offset >= 0)
                        memcpy(fibh->ebh->b_data + offset, impuse, liu);
                else
                {
                        memcpy((uint8_t *)sfi->impUse, impuse, -offset);
                        memcpy(fibh->ebh->b_data, impuse - offset, liu + offset);
                }
        }

        offset += liu;

        if (fileident)
        {
                if (adinicb || (offset + lfi < 0))
                        memcpy((uint8_t *)sfi->fileIdent + liu, fileident, lfi);
                else if (offset >= 0)
                        memcpy(fibh->ebh->b_data + offset, fileident, lfi);
                else
                {
                        memcpy((uint8_t *)sfi->fileIdent + liu, fileident, -offset);
                        memcpy(fibh->ebh->b_data, fileident - offset, lfi + offset);
                }
        }

        offset += lfi;

        if (adinicb || (offset + padlen < 0))
                memset((uint8_t *)sfi->padding + liu + lfi, 0x00, padlen);
        else if (offset >= 0)
                memset(fibh->ebh->b_data + offset, 0x00, padlen);
        else
        {
                memset((uint8_t *)sfi->padding + liu + lfi, 0x00, -offset);
                memset(fibh->ebh->b_data, 0x00, padlen + offset);
        }

        crc = udf_crc((uint8_t *)cfi + sizeof(tag), sizeof(struct fileIdentDesc) -
                sizeof(tag), 0);

        if (fibh->sbh == fibh->ebh)
                crc = udf_crc((uint8_t *)sfi->impUse,
                        crclen + sizeof(tag) - sizeof(struct fileIdentDesc), crc);
        else if (sizeof(struct fileIdentDesc) >= -fibh->soffset)
                crc = udf_crc(fibh->ebh->b_data + sizeof(struct fileIdentDesc) + fibh->soffset,
                        crclen + sizeof(tag) - sizeof(struct fileIdentDesc), crc);
        else
        {
                crc = udf_crc((uint8_t *)sfi->impUse,
                        -fibh->soffset - sizeof(struct fileIdentDesc), crc);
                crc = udf_crc(fibh->ebh->b_data, fibh->eoffset, crc);
        }

        cfi->descTag.descCRC = cpu_to_le16(crc);
        cfi->descTag.descCRCLength = cpu_to_le16(crclen);

        for (i=0; i<16; i++)
                if (i != 4)
                        checksum += ((uint8_t *)&cfi->descTag)[i];

        cfi->descTag.tagChecksum = checksum;
        if (adinicb || (sizeof(struct fileIdentDesc) <= -fibh->soffset))
                memcpy((uint8_t *)sfi, (uint8_t *)cfi, sizeof(struct fileIdentDesc));
        else
        {
                memcpy((uint8_t *)sfi, (uint8_t *)cfi, -fibh->soffset);
                memcpy(fibh->ebh->b_data, (uint8_t *)cfi - fibh->soffset,
                        sizeof(struct fileIdentDesc) + fibh->soffset);
        }

        if (adinicb)
                mark_inode_dirty(inode);
        else
        {
                if (fibh->sbh != fibh->ebh)
                        mark_buffer_dirty_inode(fibh->ebh, inode);
                mark_buffer_dirty_inode(fibh->sbh, inode);
        }
        return 0;
}

static struct fileIdentDesc *
udf_find_entry(struct inode *dir, struct dentry *dentry,
        struct udf_fileident_bh *fibh,
        struct fileIdentDesc *cfi)
{
        struct fileIdentDesc *fi=NULL;
        loff_t f_pos;
        int block, flen;
        char fname[UDF_NAME_LEN];
        char *nameptr;
        uint8_t lfi;
        uint16_t liu;
        loff_t size = (udf_ext0_offset(dir) + dir->i_size) >> 2;
        kernel_lb_addr bloc, eloc;
        uint32_t extoffset, elen, offset;
        struct buffer_head *bh = NULL;

        if (!dir)
                return NULL;

        f_pos = (udf_ext0_offset(dir) >> 2);

        fibh->soffset = fibh->eoffset = (f_pos & ((dir->i_sb->s_blocksize - 1) >> 2)) << 2;
        if (UDF_I_ALLOCTYPE(dir) == ICBTAG_FLAG_AD_IN_ICB)
                fibh->sbh = fibh->ebh = NULL;
        else if (inode_bmap(dir, f_pos >> (dir->i_sb->s_blocksize_bits - 2),
                &bloc, &extoffset, &eloc, &elen, &offset, &bh) == (EXT_RECORDED_ALLOCATED >> 30))
        {
                offset >>= dir->i_sb->s_blocksize_bits;
                block = udf_get_lb_pblock(dir->i_sb, eloc, offset);
                if ((++offset << dir->i_sb->s_blocksize_bits) < elen)
                {
                        if (UDF_I_ALLOCTYPE(dir) == ICBTAG_FLAG_AD_SHORT)
                                extoffset -= sizeof(short_ad);
                        else if (UDF_I_ALLOCTYPE(dir) == ICBTAG_FLAG_AD_LONG)
                                extoffset -= sizeof(long_ad);
                }
                else
                        offset = 0;

                if (!(fibh->sbh = fibh->ebh = udf_tread(dir->i_sb, block)))
                {
                        udf_release_data(bh);
                        return NULL;
                }
        }
        else
        {
                udf_release_data(bh);
                return NULL;
        }

        while ( (f_pos < size) )
        {
                fi = udf_fileident_read(dir, &f_pos, fibh, cfi, &bloc, &extoffset, &eloc, &elen, &offset, &bh);

                if (!fi)
                {
                        if (fibh->sbh != fibh->ebh)
                                udf_release_data(fibh->ebh);
                        udf_release_data(fibh->sbh);
                        udf_release_data(bh);
                        return NULL;
                }

                liu = le16_to_cpu(cfi->lengthOfImpUse);
                lfi = cfi->lengthFileIdent;

                if (fibh->sbh == fibh->ebh)
                {
                        nameptr = fi->fileIdent + liu;
                }
                else
                {
                        int poffset;    /* Unpaded ending offset */

                        poffset = fibh->soffset + sizeof(struct fileIdentDesc) + liu + lfi;

                        if (poffset >= lfi)
                                nameptr = (uint8_t *)(fibh->ebh->b_data + poffset - lfi);
                        else
                        {
                                nameptr = fname;
                                memcpy(nameptr, fi->fileIdent + liu, lfi - poffset);
                                memcpy(nameptr + lfi - poffset, fibh->ebh->b_data, poffset);
                        }
                }

                if ( (cfi->fileCharacteristics & FID_FILE_CHAR_DELETED) != 0 )
                {
                        if ( !UDF_QUERY_FLAG(dir->i_sb, UDF_FLAG_UNDELETE) )
                                continue;
                }
            
                if ( (cfi->fileCharacteristics & FID_FILE_CHAR_HIDDEN) != 0 )
                {
                        if ( !UDF_QUERY_FLAG(dir->i_sb, UDF_FLAG_UNHIDE) )
                                continue;
                }

                if (!lfi)
                        continue;

                if ((flen = udf_get_filename(dir->i_sb, nameptr, fname, lfi)))
                {
                        if (udf_match(flen, fname, dentry->d_name.len, dentry->d_name.name))
                        {
                                udf_release_data(bh);
                                return fi;
                        }
                }
        }
        if (fibh->sbh != fibh->ebh)
                udf_release_data(fibh->ebh);
        udf_release_data(fibh->sbh);
        udf_release_data(bh);
        return NULL;
}

/*
 * udf_lookup
 *
 * PURPOSE
 *      Look-up the inode for a given name.
 *
 * DESCRIPTION
 *      Required - lookup_dentry() will return -ENOTDIR if this routine is not
 *      available for a directory. The filesystem is useless if this routine is
 *      not available for at least the filesystem's root directory.
 *
 *      This routine is passed an incomplete dentry - it must be completed by
 *      calling d_add(dentry, inode). If the name does not exist, then the
 *      specified inode must be set to null. An error should only be returned
 *      when the lookup fails for a reason other than the name not existing.
 *      Note that the directory inode semaphore is held during the call.
 *
 *      Refer to lookup_dentry() in fs/namei.c
 *      lookup_dentry() -> lookup() -> real_lookup() -> .
 *
 * PRE-CONDITIONS
 *      dir                     Pointer to inode of parent directory.
 *      dentry                  Pointer to dentry to complete.
 *      nd                      Pointer to lookup nameidata
 *
 * POST-CONDITIONS
 *      <return>                Zero on success.
 *
 * HISTORY
 *      July 1, 1997 - Andrew E. Mileski
 *      Written, tested, and released.
 */

static struct dentry *
udf_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
{
        struct inode *inode = NULL;
        struct fileIdentDesc cfi, *fi;
        struct udf_fileident_bh fibh;

        if (dentry->d_name.len > UDF_NAME_LEN-2)
                return ERR_PTR(-ENAMETOOLONG);

        lock_kernel();
#ifdef UDF_RECOVERY
        /* temporary shorthand for specifying files by inode number */
        if (!strncmp(dentry->d_name.name, ".B=", 3) )
        {
                kernel_lb_addr lb = { 0, simple_strtoul(dentry->d_name.name+3, NULL, 0) };
                inode = udf_iget(dir->i_sb, lb);
                if (!inode)
                {
                        unlock_kernel();
                        return ERR_PTR(-EACCES);
                }
        }
        else
#endif /* UDF_RECOVERY */

        if ((fi = udf_find_entry(dir, dentry, &fibh, &cfi)))
        {
                if (fibh.sbh != fibh.ebh)
                        udf_release_data(fibh.ebh);
                udf_release_data(fibh.sbh);

                inode = udf_iget(dir->i_sb, lelb_to_cpu(cfi.icb.extLocation));
                if ( !inode )
                {
                        unlock_kernel();
                        return ERR_PTR(-EACCES);
                }
        }
        unlock_kernel();
        d_add(dentry, inode);
        return NULL;
}

static struct fileIdentDesc *
udf_add_entry(struct inode *dir, struct dentry *dentry,
        struct udf_fileident_bh *fibh,
        struct fileIdentDesc *cfi, int *err)
{
        struct super_block *sb;
        struct fileIdentDesc *fi=NULL;
        char name[UDF_NAME_LEN], fname[UDF_NAME_LEN];
        int namelen;
        loff_t f_pos;
        int flen;
        char *nameptr;
        loff_t size = (udf_ext0_offset(dir) + dir->i_size) >> 2;
        int nfidlen;
        uint8_t lfi;
        uint16_t liu;
        int block;
        kernel_lb_addr bloc, eloc;
        uint32_t extoffset, elen, offset;
        struct buffer_head *bh = NULL;

        sb = dir->i_sb;

        if (dentry)
        {
                if (!dentry->d_name.len)
                {
                        *err = -EINVAL;
                        return NULL;
                }

                if ( !(namelen = udf_put_filename(sb, dentry->d_name.name, name, dentry->d_name.len)))
                {
                        *err = -ENAMETOOLONG;
                        return NULL;
                }
        }
        else
                namelen = 0;

        nfidlen = (sizeof(struct fileIdentDesc) + namelen + 3) & ~3;

        f_pos = (udf_ext0_offset(dir) >> 2);

        fibh->soffset = fibh->eoffset = (f_pos & ((dir->i_sb->s_blocksize - 1) >> 2)) << 2;
        if (UDF_I_ALLOCTYPE(dir) == ICBTAG_FLAG_AD_IN_ICB)
                fibh->sbh = fibh->ebh = NULL;
        else if (inode_bmap(dir, f_pos >> (dir->i_sb->s_blocksize_bits - 2),
                &bloc, &extoffset, &eloc, &elen, &offset, &bh) == (EXT_RECORDED_ALLOCATED >> 30))
        {
                offset >>= dir->i_sb->s_blocksize_bits;
                block = udf_get_lb_pblock(dir->i_sb, eloc, offset);
                if ((++offset << dir->i_sb->s_blocksize_bits) < elen)
                {
                        if (UDF_I_ALLOCTYPE(dir) == ICBTAG_FLAG_AD_SHORT)
                                extoffset -= sizeof(short_ad);
                        else if (UDF_I_ALLOCTYPE(dir) == ICBTAG_FLAG_AD_LONG)
                                extoffset -= sizeof(long_ad);
                }
                else
                        offset = 0;

                if (!(fibh->sbh = fibh->ebh = udf_tread(dir->i_sb, block)))
                {
                        udf_release_data(bh);
                        *err = -EIO;
                        return NULL;
                }

                block = UDF_I_LOCATION(dir).logicalBlockNum;

        }
        else
        {
                block = udf_get_lb_pblock(dir->i_sb, UDF_I_LOCATION(dir), 0);
                fibh->sbh = fibh->ebh = NULL;
                fibh->soffset = fibh->eoffset = sb->s_blocksize;
                goto add;
        }

        while ( (f_pos < size) )
        {
                fi = udf_fileident_read(dir, &f_pos, fibh, cfi, &bloc, &extoffset, &eloc, &elen, &offset, &bh);

                if (!fi)
                {
                        if (fibh->sbh != fibh->ebh)
                                udf_release_data(fibh->ebh);
                        udf_release_data(fibh->sbh);
                        udf_release_data(bh);
                        *err = -EIO;
                        return NULL;
                }

                liu = le16_to_cpu(cfi->lengthOfImpUse);
                lfi = cfi->lengthFileIdent;

                if (fibh->sbh == fibh->ebh)
                        nameptr = fi->fileIdent + liu;
                else
                {
                        int poffset;    /* Unpaded ending offset */

                        poffset = fibh->soffset + sizeof(struct fileIdentDesc) + liu + lfi;

                        if (poffset >= lfi)
                                nameptr = (char *)(fibh->ebh->b_data + poffset - lfi);
                        else
                        {
                                nameptr = fname;
                                memcpy(nameptr, fi->fileIdent + liu, lfi - poffset);
                                memcpy(nameptr + lfi - poffset, fibh->ebh->b_data, poffset);
                        }
                }

                if ( (cfi->fileCharacteristics & FID_FILE_CHAR_DELETED) != 0 )
                {
                        if (((sizeof(struct fileIdentDesc) + liu + lfi + 3) & ~3) == nfidlen)
                        {
                                udf_release_data(bh);
                                cfi->descTag.tagSerialNum = cpu_to_le16(1);
                                cfi->fileVersionNum = cpu_to_le16(1);
                                cfi->fileCharacteristics = 0;
                                cfi->lengthFileIdent = namelen;
                                cfi->lengthOfImpUse = cpu_to_le16(0);
                                if (!udf_write_fi(dir, cfi, fi, fibh, NULL, name))
                                        return fi;
                                else
                                {
                                        *err = -EIO;
                                        return NULL;
                                }
                        }
                }

                if (!lfi || !dentry)
                        continue;

                if ((flen = udf_get_filename(dir->i_sb, nameptr, fname, lfi)) &&
                        udf_match(flen, fname, dentry->d_name.len, dentry->d_name.name))
                {
                        if (fibh->sbh != fibh->ebh)
                                udf_release_data(fibh->ebh);
                        udf_release_data(fibh->sbh);
                        udf_release_data(bh);
                        *err = -EEXIST;
                        return NULL;
                }
        }

add:
        f_pos += nfidlen;

        if (UDF_I_ALLOCTYPE(dir) == ICBTAG_FLAG_AD_IN_ICB &&
                sb->s_blocksize - fibh->eoffset < nfidlen)
        {
                udf_release_data(bh);
                bh = NULL;
                fibh->soffset -= udf_ext0_offset(dir);
                fibh->eoffset -= udf_ext0_offset(dir);
                f_pos -= (udf_ext0_offset(dir) >> 2);
                if (fibh->sbh != fibh->ebh)
                        udf_release_data(fibh->ebh);
                udf_release_data(fibh->sbh);
                if (!(fibh->sbh = fibh->ebh = udf_expand_dir_adinicb(dir, &block, err)))
                        return NULL;
                bloc = UDF_I_LOCATION(dir);
                eloc.logicalBlockNum = block;
                eloc.partitionReferenceNum = UDF_I_LOCATION(dir).partitionReferenceNum;
                elen = dir->i_sb->s_blocksize;
                extoffset = udf_file_entry_alloc_offset(dir);
                if (UDF_I_ALLOCTYPE(dir) == ICBTAG_FLAG_AD_SHORT)
                        extoffset += sizeof(short_ad);
                else if (UDF_I_ALLOCTYPE(dir) == ICBTAG_FLAG_AD_LONG)
                        extoffset += sizeof(long_ad);
        }

        if (sb->s_blocksize - fibh->eoffset >= nfidlen)
        {
                fibh->soffset = fibh->eoffset;
                fibh->eoffset += nfidlen;
                if (fibh->sbh != fibh->ebh)
                {
                        udf_release_data(fibh->sbh);
                        fibh->sbh = fibh->ebh;
                }

                if (UDF_I_ALLOCTYPE(dir) == ICBTAG_FLAG_AD_IN_ICB)
                {
                        block = UDF_I_LOCATION(dir).logicalBlockNum;
                        fi = (struct fileIdentDesc *)(UDF_I_DATA(dir) + fibh->soffset - udf_ext0_offset(dir) + UDF_I_LENEATTR(dir));
                }
                else
                {
                        block = eloc.logicalBlockNum + ((elen - 1) >>
                                dir->i_sb->s_blocksize_bits);
                        fi = (struct fileIdentDesc *)(fibh->sbh->b_data + fibh->soffset);
                }
        }
        else
        {
                fibh->soffset = fibh->eoffset - sb->s_blocksize;
                fibh->eoffset += nfidlen - sb->s_blocksize;
                if (fibh->sbh != fibh->ebh)
                {
                        udf_release_data(fibh->sbh);
                        fibh->sbh = fibh->ebh;
                }

                block = eloc.logicalBlockNum + ((elen - 1) >>
                        dir->i_sb->s_blocksize_bits);

                if (!(fibh->ebh = udf_bread(dir, f_pos >> (dir->i_sb->s_blocksize_bits - 2), 1, err)))
                {
                        udf_release_data(bh);
                        udf_release_data(fibh->sbh);
                        return NULL;
                }

                if (!(fibh->soffset))
                {
                        if (udf_next_aext(dir, &bloc, &extoffset, &eloc, &elen, &bh, 1) ==
                                (EXT_RECORDED_ALLOCATED >> 30))
                        {
                                block = eloc.logicalBlockNum + ((elen - 1) >>
                                        dir->i_sb->s_blocksize_bits);
                        }
                        else
                                block ++;

                        udf_release_data(fibh->sbh);
                        fibh->sbh = fibh->ebh;
                        fi = (struct fileIdentDesc *)(fibh->sbh->b_data);
                }
                else
                {
                        fi = (struct fileIdentDesc *)
                                (fibh->sbh->b_data + sb->s_blocksize + fibh->soffset);
                }
        }

        memset(cfi, 0, sizeof(struct fileIdentDesc));
        if (UDF_SB_UDFREV(sb) >= 0x0200)
                udf_new_tag((char *)cfi, TAG_IDENT_FID, 3, 1, block, sizeof(tag));
        else
                udf_new_tag((char *)cfi, TAG_IDENT_FID, 2, 1, block, sizeof(tag));
        cfi->fileVersionNum = cpu_to_le16(1);
        cfi->lengthFileIdent = namelen;
        cfi->lengthOfImpUse = cpu_to_le16(0);
        if (!udf_write_fi(dir, cfi, fi, fibh, NULL, name))
        {
                udf_release_data(bh);
                dir->i_size += nfidlen;
                if (UDF_I_ALLOCTYPE(dir) == ICBTAG_FLAG_AD_IN_ICB)
                        UDF_I_LENALLOC(dir) += nfidlen;
                mark_inode_dirty(dir);
                return fi;
        }
        else
        {
                udf_release_data(bh);
                if (fibh->sbh != fibh->ebh)
                        udf_release_data(fibh->ebh);
                udf_release_data(fibh->sbh);
                *err = -EIO;
                return NULL;
        }
}

static int udf_delete_entry(struct inode *inode, struct fileIdentDesc *fi,
        struct udf_fileident_bh *fibh, struct fileIdentDesc *cfi)
{
        cfi->fileCharacteristics |= FID_FILE_CHAR_DELETED;
        if (UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_STRICT))
                memset(&(cfi->icb), 0x00, sizeof(long_ad));
        return udf_write_fi(inode, cfi, fi, fibh, NULL, NULL);
}

static int udf_create(struct inode *dir, struct dentry *dentry, int mode, struct nameidata *nd)
{
        struct udf_fileident_bh fibh;
        struct inode *inode;
        struct fileIdentDesc cfi, *fi;
        int err;

        lock_kernel();
        inode = udf_new_inode(dir, mode, &err);
        if (!inode)
        {
                unlock_kernel();
                return err;
        }

        if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_IN_ICB)
                inode->i_data.a_ops = &udf_adinicb_aops;
        else
                inode->i_data.a_ops = &udf_aops;
        inode->i_op = &udf_file_inode_operations;
        inode->i_fop = &udf_file_operations;
        inode->i_mode = mode;
        mark_inode_dirty(inode);

        if (!(fi = udf_add_entry(dir, dentry, &fibh, &cfi, &err)))
        {
                inode->i_nlink --;
                mark_inode_dirty(inode);
                iput(inode);
                unlock_kernel();
                return err;
        }
        cfi.icb.extLength = cpu_to_le32(inode->i_sb->s_blocksize);
        cfi.icb.extLocation = cpu_to_lelb(UDF_I_LOCATION(inode));
        *(__le32 *)((struct allocDescImpUse *)cfi.icb.impUse)->impUse =
                cpu_to_le32(UDF_I_UNIQUE(inode) & 0x00000000FFFFFFFFUL);
        udf_write_fi(dir, &cfi, fi, &fibh, NULL, NULL);
        if (UDF_I_ALLOCTYPE(dir) == ICBTAG_FLAG_AD_IN_ICB)
        {
                mark_inode_dirty(dir);
        }
        if (fibh.sbh != fibh.ebh)
                udf_release_data(fibh.ebh);
        udf_release_data(fibh.sbh);
        unlock_kernel();
        d_instantiate(dentry, inode);
        return 0;
}

static int udf_mknod(struct inode * dir, struct dentry * dentry, int mode, dev_t rdev)
{
        struct inode * inode;
        struct udf_fileident_bh fibh;
        struct fileIdentDesc cfi, *fi;
        int err;

        if (!old_valid_dev(rdev))
                return -EINVAL;

        lock_kernel();
        err = -EIO;
        inode = udf_new_inode(dir, mode, &err);
        if (!inode)
                goto out;

        inode->i_uid = current->fsuid;
        init_special_inode(inode, mode, rdev);
        if (!(fi = udf_add_entry(dir, dentry, &fibh, &cfi, &err)))
        {
                inode->i_nlink --;
                mark_inode_dirty(inode);
                iput(inode);
                unlock_kernel();
                return err;
        }
        cfi.icb.extLength = cpu_to_le32(inode->i_sb->s_blocksize);
        cfi.icb.extLocation = cpu_to_lelb(UDF_I_LOCATION(inode));
        *(__le32 *)((struct allocDescImpUse *)cfi.icb.impUse)->impUse =
                cpu_to_le32(UDF_I_UNIQUE(inode) & 0x00000000FFFFFFFFUL);
        udf_write_fi(dir, &cfi, fi, &fibh, NULL, NULL);
        if (UDF_I_ALLOCTYPE(dir) == ICBTAG_FLAG_AD_IN_ICB)
        {
                mark_inode_dirty(dir);
        }
        mark_inode_dirty(inode);

        if (fibh.sbh != fibh.ebh)
                udf_release_data(fibh.ebh);
        udf_release_data(fibh.sbh);
        d_instantiate(dentry, inode);
        err = 0;
out:
        unlock_kernel();
        return err;
}

static int udf_mkdir(struct inode * dir, struct dentry * dentry, int mode)
{
        struct inode * inode;
        struct udf_fileident_bh fibh;
        struct fileIdentDesc cfi, *fi;
        int err;

        lock_kernel();
        err = -EMLINK;
        if (dir->i_nlink >= (256<<sizeof(dir->i_nlink))-1)
                goto out;

        err = -EIO;
        inode = udf_new_inode(dir, S_IFDIR, &err);
        if (!inode)
                goto out;

        inode->i_op = &udf_dir_inode_operations;
        inode->i_fop = &udf_dir_operations;
        if (!(fi = udf_add_entry(inode, NULL, &fibh, &cfi, &err)))
        {
                inode->i_nlink--;
                mark_inode_dirty(inode);
                iput(inode);
                goto out;
        }
        inode->i_nlink = 2;
        cfi.icb.extLength = cpu_to_le32(inode->i_sb->s_blocksize);
        cfi.icb.extLocation = cpu_to_lelb(UDF_I_LOCATION(dir));
        *(__le32 *)((struct allocDescImpUse *)cfi.icb.impUse)->impUse =
                cpu_to_le32(UDF_I_UNIQUE(dir) & 0x00000000FFFFFFFFUL);
        cfi.fileCharacteristics = FID_FILE_CHAR_DIRECTORY | FID_FILE_CHAR_PARENT;
        udf_write_fi(inode, &cfi, fi, &fibh, NULL, NULL);
        udf_release_data(fibh.sbh);
        inode->i_mode = S_IFDIR | mode;
        if (dir->i_mode & S_ISGID)
                inode->i_mode |= S_ISGID;
        mark_inode_dirty(inode);

        if (!(fi = udf_add_entry(dir, dentry, &fibh, &cfi, &err)))
        {
                inode->i_nlink = 0;
                mark_inode_dirty(inode);
                iput(inode);
                goto out;
        }
        cfi.icb.extLength = cpu_to_le32(inode->i_sb->s_blocksize);
        cfi.icb.extLocation = cpu_to_lelb(UDF_I_LOCATION(inode));
        *(__le32 *)((struct allocDescImpUse *)cfi.icb.impUse)->impUse =
                cpu_to_le32(UDF_I_UNIQUE(inode) & 0x00000000FFFFFFFFUL);
        cfi.fileCharacteristics |= FID_FILE_CHAR_DIRECTORY;
        udf_write_fi(dir, &cfi, fi, &fibh, NULL, NULL);
        dir->i_nlink++;
        mark_inode_dirty(dir);
        d_instantiate(dentry, inode);
        if (fibh.sbh != fibh.ebh)
                udf_release_data(fibh.ebh);
        udf_release_data(fibh.sbh);
        err = 0;
out:
        unlock_kernel();
        return err;
}

static int empty_dir(struct inode *dir)
{
        struct fileIdentDesc *fi, cfi;
        struct udf_fileident_bh fibh;
        loff_t f_pos;
        loff_t size = (udf_ext0_offset(dir) + dir->i_size) >> 2;
        int block;
        kernel_lb_addr bloc, eloc;
        uint32_t extoffset, elen, offset;
        struct buffer_head *bh = NULL;

        f_pos = (udf_ext0_offset(dir) >> 2);

        fibh.soffset = fibh.eoffset = (f_pos & ((dir->i_sb->s_blocksize - 1) >> 2)) << 2;

        if (UDF_I_ALLOCTYPE(dir) == ICBTAG_FLAG_AD_IN_ICB)
                fibh.sbh = fibh.ebh = NULL;
        else if (inode_bmap(dir, f_pos >> (dir->i_sb->s_blocksize_bits - 2),
                &bloc, &extoffset, &eloc, &elen, &offset, &bh) == (EXT_RECORDED_ALLOCATED >> 30))
        {
                offset >>= dir->i_sb->s_blocksize_bits;
                block = udf_get_lb_pblock(dir->i_sb, eloc, offset);
                if ((++offset << dir->i_sb->s_blocksize_bits) < elen)
                {
                        if (UDF_I_ALLOCTYPE(dir) == ICBTAG_FLAG_AD_SHORT)
                                extoffset -= sizeof(short_ad);
                        else if (UDF_I_ALLOCTYPE(dir) == ICBTAG_FLAG_AD_LONG)
                                extoffset -= sizeof(long_ad);
                }
                else
                        offset = 0;

                if (!(fibh.sbh = fibh.ebh = udf_tread(dir->i_sb, block)))
                {
                        udf_release_data(bh);
                        return 0;
                }
        }
        else
        {
                udf_release_data(bh);
                return 0;
        }


        while ( (f_pos < size) )
        {
                fi = udf_fileident_read(dir, &f_pos, &fibh, &cfi, &bloc, &extoffset, &eloc, &elen, &offset, &bh);

                if (!fi)
                {
                        if (fibh.sbh != fibh.ebh)
                                udf_release_data(fibh.ebh);
                        udf_release_data(fibh.sbh);
                        udf_release_data(bh);
                        return 0;
                }

                if (cfi.lengthFileIdent && (cfi.fileCharacteristics & FID_FILE_CHAR_DELETED) == 0)
                {
                        if (fibh.sbh != fibh.ebh)
                                udf_release_data(fibh.ebh);
                        udf_release_data(fibh.sbh);
                        udf_release_data(bh);
                        return 0;
                }
        }
        if (fibh.sbh != fibh.ebh)
                udf_release_data(fibh.ebh);
        udf_release_data(fibh.sbh);
        udf_release_data(bh);
        return 1;
}

static int udf_rmdir(struct inode * dir, struct dentry * dentry)
{
        int retval;
        struct inode * inode = dentry->d_inode;
        struct udf_fileident_bh fibh;
        struct fileIdentDesc *fi, cfi;
        kernel_lb_addr tloc;

        retval = -ENOENT;
        lock_kernel();
        fi = udf_find_entry(dir, dentry, &fibh, &cfi);
        if (!fi)
                goto out;

        retval = -EIO;
        tloc = lelb_to_cpu(cfi.icb.extLocation);
        if (udf_get_lb_pblock(dir->i_sb, tloc, 0) != inode->i_ino)
                goto end_rmdir;
        retval = -ENOTEMPTY;
        if (!empty_dir(inode))
                goto end_rmdir;
        retval = udf_delete_entry(dir, fi, &fibh, &cfi);
        if (retval)
                goto end_rmdir;
        if (inode->i_nlink != 2)
                udf_warning(inode->i_sb, "udf_rmdir",
                        "empty directory has nlink != 2 (%d)",
                        inode->i_nlink);
        inode->i_nlink = 0;
        inode->i_size = 0;
        mark_inode_dirty(inode);
        dir->i_nlink --;
        inode->i_ctime = dir->i_ctime = dir->i_mtime = current_fs_time(dir->i_sb);
        mark_inode_dirty(dir);

end_rmdir:
        if (fibh.sbh != fibh.ebh)
                udf_release_data(fibh.ebh);
        udf_release_data(fibh.sbh);
out:
        unlock_kernel();
        return retval;
}

static int udf_unlink(struct inode * dir, struct dentry * dentry)
{
        int retval;
        struct inode * inode = dentry->d_inode;
        struct udf_fileident_bh fibh;
        struct fileIdentDesc *fi;
        struct fileIdentDesc cfi;
        kernel_lb_addr tloc;

        retval = -ENOENT;
        lock_kernel();
        fi = udf_find_entry(dir, dentry, &fibh, &cfi);
        if (!fi)
                goto out;

        retval = -EIO;
        tloc = lelb_to_cpu(cfi.icb.extLocation);
        if (udf_get_lb_pblock(dir->i_sb, tloc, 0) != inode->i_ino)
                goto end_unlink;

        if (!inode->i_nlink)
        {
                udf_debug("Deleting nonexistent file (%lu), %d\n",
                        inode->i_ino, inode->i_nlink);
                inode->i_nlink = 1;
        }
        retval = udf_delete_entry(dir, fi, &fibh, &cfi);
        if (retval)
                goto end_unlink;
        dir->i_ctime = dir->i_mtime = current_fs_time(dir->i_sb);
        mark_inode_dirty(dir);
        inode->i_nlink--;
        mark_inode_dirty(inode);
        inode->i_ctime = dir->i_ctime;
        retval = 0;

end_unlink:
        if (fibh.sbh != fibh.ebh)
                udf_release_data(fibh.ebh);
        udf_release_data(fibh.sbh);
out:
        unlock_kernel();
        return retval;
}

static int udf_symlink(struct inode * dir, struct dentry * dentry, const char * symname)
{
        struct inode * inode;
        struct pathComponent *pc;
        char *compstart;
        struct udf_fileident_bh fibh;
        struct buffer_head *bh = NULL;
        int eoffset, elen = 0;
        struct fileIdentDesc *fi;
        struct fileIdentDesc cfi;
        char *ea;
        int err;
        int block;
        char name[UDF_NAME_LEN];
        int namelen;

        lock_kernel();
        if (!(inode = udf_new_inode(dir, S_IFLNK, &err)))
                goto out;

        inode->i_mode = S_IFLNK | S_IRWXUGO;
        inode->i_data.a_ops = &udf_symlink_aops;
        inode->i_op = &page_symlink_inode_operations;

        if (UDF_I_ALLOCTYPE(inode) != ICBTAG_FLAG_AD_IN_ICB)
        {
                struct buffer_head *bh = NULL;
                kernel_lb_addr bloc, eloc;
                uint32_t elen, extoffset;

                block = udf_new_block(inode->i_sb, inode,
                        UDF_I_LOCATION(inode).partitionReferenceNum,
                        UDF_I_LOCATION(inode).logicalBlockNum, &err);
                if (!block)
                        goto out_no_entry;
                bloc = UDF_I_LOCATION(inode);
                eloc.logicalBlockNum = block;
                eloc.partitionReferenceNum = UDF_I_LOCATION(inode).partitionReferenceNum;
                elen = inode->i_sb->s_blocksize;
                UDF_I_LENEXTENTS(inode) = elen;
                extoffset = udf_file_entry_alloc_offset(inode);
                udf_add_aext(inode, &bloc, &extoffset, eloc, elen, &bh, 0);
                udf_release_data(bh);

                block = udf_get_pblock(inode->i_sb, block,
                        UDF_I_LOCATION(inode).partitionReferenceNum, 0);
                bh = udf_tread(inode->i_sb, block);
                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);
                ea = bh->b_data + udf_ext0_offset(inode);
        }
        else
                ea = UDF_I_DATA(inode) + UDF_I_LENEATTR(inode);

        eoffset = inode->i_sb->s_blocksize - udf_ext0_offset(inode);
        pc = (struct pathComponent *)ea;

        if (*symname == '/')
        {
                do
                {
                        symname++;
                } while (*symname == '/');

                pc->componentType = 1;
                pc->lengthComponentIdent = 0;
                pc->componentFileVersionNum = 0;
                pc += sizeof(struct pathComponent);
                elen += sizeof(struct pathComponent);
        }

        err = -ENAMETOOLONG;

        while (*symname)
        {
                if (elen + sizeof(struct pathComponent) > eoffset)
                        goto out_no_entry;

                pc = (struct pathComponent *)(ea + elen);

                compstart = (char *)symname;

                do
                {
                        symname++;
                } while (*symname && *symname != '/');

                pc->componentType = 5;
                pc->lengthComponentIdent = 0;
                pc->componentFileVersionNum = 0;
                if (compstart[0] == '.')
                {
                        if ((symname-compstart) == 1)
                                pc->componentType = 4;
                        else if ((symname-compstart) == 2 && compstart[1] == '.')
                                pc->componentType = 3;
                }

                if (pc->componentType == 5)
                {
                        if ( !(namelen = udf_put_filename(inode->i_sb, compstart, name, symname-compstart)))
                                goto out_no_entry;

                        if (elen + sizeof(struct pathComponent) + namelen > eoffset)
                                goto out_no_entry;
                        else
                                pc->lengthComponentIdent = namelen;

                        memcpy(pc->componentIdent, name, namelen);
                }

                elen += sizeof(struct pathComponent) + pc->lengthComponentIdent;

                if (*symname)
                {
                        do
                        {
                                symname++;
                        } while (*symname == '/');
                }
        }

        udf_release_data(bh);
        inode->i_size = elen;
        if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_IN_ICB)
                UDF_I_LENALLOC(inode) = inode->i_size;
        mark_inode_dirty(inode);

        if (!(fi = udf_add_entry(dir, dentry, &fibh, &cfi, &err)))
                goto out_no_entry;
        cfi.icb.extLength = cpu_to_le32(inode->i_sb->s_blocksize);
        cfi.icb.extLocation = cpu_to_lelb(UDF_I_LOCATION(inode));
        if (UDF_SB_LVIDBH(inode->i_sb))
        {
                struct logicalVolHeaderDesc *lvhd;
                uint64_t uniqueID;
                lvhd = (struct logicalVolHeaderDesc *)(UDF_SB_LVID(inode->i_sb)->logicalVolContentsUse);
                uniqueID = le64_to_cpu(lvhd->uniqueID);
                *(__le32 *)((struct allocDescImpUse *)cfi.icb.impUse)->impUse =
                        cpu_to_le32(uniqueID & 0x00000000FFFFFFFFUL);
                if (!(++uniqueID & 0x00000000FFFFFFFFUL))
                        uniqueID += 16;
                lvhd->uniqueID = cpu_to_le64(uniqueID);
                mark_buffer_dirty(UDF_SB_LVIDBH(inode->i_sb));
        }
        udf_write_fi(dir, &cfi, fi, &fibh, NULL, NULL);
        if (UDF_I_ALLOCTYPE(dir) == ICBTAG_FLAG_AD_IN_ICB)
        {
                mark_inode_dirty(dir);
        }
        if (fibh.sbh != fibh.ebh)
                udf_release_data(fibh.ebh);
        udf_release_data(fibh.sbh);
        d_instantiate(dentry, inode);
        err = 0;

out:
        unlock_kernel();
        return err;

out_no_entry:
        inode->i_nlink--;
        mark_inode_dirty(inode);
        iput(inode);
        goto out;
}

static int udf_link(struct dentry * old_dentry, struct inode * dir,
         struct dentry *dentry)
{
        struct inode *inode = old_dentry->d_inode;
        struct udf_fileident_bh fibh;
        struct fileIdentDesc cfi, *fi;
        int err;

        lock_kernel();
        if (inode->i_nlink >= (256<<sizeof(inode->i_nlink))-1)
        {
                unlock_kernel();
                return -EMLINK;
        }

        if (!(fi = udf_add_entry(dir, dentry, &fibh, &cfi, &err)))
        {
                unlock_kernel();
                return err;
        }
        cfi.icb.extLength = cpu_to_le32(inode->i_sb->s_blocksize);
        cfi.icb.extLocation = cpu_to_lelb(UDF_I_LOCATION(inode));
        if (UDF_SB_LVIDBH(inode->i_sb))
        {
                struct logicalVolHeaderDesc *lvhd;
                uint64_t uniqueID;
                lvhd = (struct logicalVolHeaderDesc *)(UDF_SB_LVID(inode->i_sb)->logicalVolContentsUse);
                uniqueID = le64_to_cpu(lvhd->uniqueID);
                *(__le32 *)((struct allocDescImpUse *)cfi.icb.impUse)->impUse =
                        cpu_to_le32(uniqueID & 0x00000000FFFFFFFFUL);
                if (!(++uniqueID & 0x00000000FFFFFFFFUL))
                        uniqueID += 16;
                lvhd->uniqueID = cpu_to_le64(uniqueID);
                mark_buffer_dirty(UDF_SB_LVIDBH(inode->i_sb));
        }
        udf_write_fi(dir, &cfi, fi, &fibh, NULL, NULL);
        if (UDF_I_ALLOCTYPE(dir) == ICBTAG_FLAG_AD_IN_ICB)
        {
                mark_inode_dirty(dir);
        }
        if (fibh.sbh != fibh.ebh)
                udf_release_data(fibh.ebh);
        udf_release_data(fibh.sbh);
        inode->i_nlink ++;
        inode->i_ctime = current_fs_time(inode->i_sb);
        mark_inode_dirty(inode);
        atomic_inc(&inode->i_count);
        d_instantiate(dentry, inode);
        unlock_kernel();
        return 0;
}

/* Anybody can rename anything with this: the permission checks are left to the
 * higher-level routines.
 */
static int udf_rename (struct inode * old_dir, struct dentry * old_dentry,
        struct inode * new_dir, struct dentry * new_dentry)
{
        struct inode * old_inode = old_dentry->d_inode;
        struct inode * new_inode = new_dentry->d_inode;
        struct udf_fileident_bh ofibh, nfibh;
        struct fileIdentDesc *ofi = NULL, *nfi = NULL, *dir_fi = NULL, ocfi, ncfi;
        struct buffer_head *dir_bh = NULL;
        int retval = -ENOENT;
        kernel_lb_addr tloc;

        lock_kernel();
        if ((ofi = udf_find_entry(old_dir, old_dentry, &ofibh, &ocfi)))
        {
                if (ofibh.sbh != ofibh.ebh)
                        udf_release_data(ofibh.ebh);
                udf_release_data(ofibh.sbh);
        }
        tloc = lelb_to_cpu(ocfi.icb.extLocation);
        if (!ofi || udf_get_lb_pblock(old_dir->i_sb, tloc, 0)
                                        != old_inode->i_ino)
                goto end_rename;

        nfi = udf_find_entry(new_dir, new_dentry, &nfibh, &ncfi);
        if (nfi)
        {
                if (!new_inode)
                {
                        if (nfibh.sbh != nfibh.ebh)
                                udf_release_data(nfibh.ebh);
                        udf_release_data(nfibh.sbh);
                        nfi = NULL;
                }
        }
        if (S_ISDIR(old_inode->i_mode))
        {
                uint32_t offset = udf_ext0_offset(old_inode);

                if (new_inode)
                {
                        retval = -ENOTEMPTY;
                        if (!empty_dir(new_inode))
                                goto end_rename;
                }
                retval = -EIO;
                if (UDF_I_ALLOCTYPE(old_inode) == ICBTAG_FLAG_AD_IN_ICB)
                {
                        dir_fi = udf_get_fileident(UDF_I_DATA(old_inode) -
                                (UDF_I_EFE(old_inode) ?
                                        sizeof(struct extendedFileEntry) :
                                        sizeof(struct fileEntry)),
                                old_inode->i_sb->s_blocksize, &offset);
                }
                else
                {
                        dir_bh = udf_bread(old_inode, 0, 0, &retval);
                        if (!dir_bh)
                                goto end_rename;
                        dir_fi = udf_get_fileident(dir_bh->b_data, old_inode->i_sb->s_blocksize, &offset);
                }
                if (!dir_fi)
                        goto end_rename;
                tloc = lelb_to_cpu(dir_fi->icb.extLocation);
                if (udf_get_lb_pblock(old_inode->i_sb, tloc, 0)
                                        != old_dir->i_ino)
                        goto end_rename;

                retval = -EMLINK;
                if (!new_inode && new_dir->i_nlink >= (256<<sizeof(new_dir->i_nlink))-1)
                        goto end_rename;
        }
        if (!nfi)
        {
                nfi = udf_add_entry(new_dir, new_dentry, &nfibh, &ncfi, &retval);
                if (!nfi)
                        goto end_rename;
        }

        /*
         * Like most other Unix systems, set the ctime for inodes on a
         * rename.
         */
        old_inode->i_ctime = current_fs_time(old_inode->i_sb);
        mark_inode_dirty(old_inode);

        /*
         * ok, that's it
         */
        ncfi.fileVersionNum = ocfi.fileVersionNum;
        ncfi.fileCharacteristics = ocfi.fileCharacteristics;
        memcpy(&(ncfi.icb), &(ocfi.icb), sizeof(long_ad));
        udf_write_fi(new_dir, &ncfi, nfi, &nfibh, NULL, NULL);

        /* The old fid may have moved - find it again */
        ofi = udf_find_entry(old_dir, old_dentry, &ofibh, &ocfi);
        udf_delete_entry(old_dir, ofi, &ofibh, &ocfi);

        if (new_inode)
        {
                new_inode->i_nlink--;
                new_inode->i_ctime = current_fs_time(new_inode->i_sb);
                mark_inode_dirty(new_inode);
        }
        old_dir->i_ctime = old_dir->i_mtime = current_fs_time(old_dir->i_sb);
        mark_inode_dirty(old_dir);

        if (dir_fi)
        {
                dir_fi->icb.extLocation = cpu_to_lelb(UDF_I_LOCATION(new_dir));
                udf_update_tag((char *)dir_fi, (sizeof(struct fileIdentDesc) +
                        le16_to_cpu(dir_fi->lengthOfImpUse) + 3) & ~3);
                if (UDF_I_ALLOCTYPE(old_inode) == ICBTAG_FLAG_AD_IN_ICB)
                {
                        mark_inode_dirty(old_inode);
                }
                else
                        mark_buffer_dirty_inode(dir_bh, old_inode);
                old_dir->i_nlink --;
                mark_inode_dirty(old_dir);
                if (new_inode)
                {
                        new_inode->i_nlink --;
                        mark_inode_dirty(new_inode);
                }
                else
                {
                        new_dir->i_nlink ++;
                        mark_inode_dirty(new_dir);
                }
        }

        if (ofi)
        {
                if (ofibh.sbh != ofibh.ebh)
                        udf_release_data(ofibh.ebh);
                udf_release_data(ofibh.sbh);
        }

        retval = 0;

end_rename:
        udf_release_data(dir_bh);
        if (nfi)
        {
                if (nfibh.sbh != nfibh.ebh)
                        udf_release_data(nfibh.ebh);
                udf_release_data(nfibh.sbh);
        }
        unlock_kernel();
        return retval;
}

struct inode_operations udf_dir_inode_operations = {
        .lookup                         = udf_lookup,
        .create                         = udf_create,
        .link                           = udf_link,
        .unlink                         = udf_unlink,
        .symlink                        = udf_symlink,
        .mkdir                          = udf_mkdir,
        .rmdir                          = udf_rmdir,
        .mknod                          = udf_mknod,
        .rename                         = udf_rename,
};