root/fs/udf/namei.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * namei.c
 *
 * PURPOSE
 *      Inode name handling routines for the OSTA-UDF(tm) filesystem.
 *
 * COPYRIGHT
 *  (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/sched.h>
#include <linux/crc-itu-t.h>
#include <linux/exportfs.h>
#include <linux/iversion.h>

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

        return !memcmp(name1, name2, len1);
}

/**
 * udf_fiiter_find_entry - find entry in given directory.
 *
 * @dir:        directory inode to search in
 * @child:      qstr of the name
 * @iter:       iter to use for searching
 *
 * This function searches in the directory @dir for a file name @child. When
 * found, @iter points to the position in the directory with given entry.
 *
 * Returns 0 on success, < 0 on error (including -ENOENT).
 */
static int udf_fiiter_find_entry(struct inode *dir, const struct qstr *child,
                                 struct udf_fileident_iter *iter)
{
        int flen;
        unsigned char *fname = NULL;
        struct super_block *sb = dir->i_sb;
        int isdotdot = child->len == 2 &&
                child->name[0] == '.' && child->name[1] == '.';
        int ret;

        fname = kmalloc(UDF_NAME_LEN, GFP_KERNEL);
        if (!fname)
                return -ENOMEM;

        for (ret = udf_fiiter_init(iter, dir, 0);
             !ret && iter->pos < dir->i_size;
             ret = udf_fiiter_advance(iter)) {
                if (iter->fi.fileCharacteristics & FID_FILE_CHAR_DELETED) {
                        if (!UDF_QUERY_FLAG(sb, UDF_FLAG_UNDELETE))
                                continue;
                }

                if (iter->fi.fileCharacteristics & FID_FILE_CHAR_HIDDEN) {
                        if (!UDF_QUERY_FLAG(sb, UDF_FLAG_UNHIDE))
                                continue;
                }

                if ((iter->fi.fileCharacteristics & FID_FILE_CHAR_PARENT) &&
                    isdotdot)
                        goto out_ok;

                if (!iter->fi.lengthFileIdent)
                        continue;

                flen = udf_get_filename(sb, iter->name,
                                iter->fi.lengthFileIdent, fname, UDF_NAME_LEN);
                if (flen < 0) {
                        ret = flen;
                        goto out_err;
                }

                if (udf_match(flen, fname, child->len, child->name))
                        goto out_ok;
        }
        if (!ret)
                ret = -ENOENT;

out_err:
        udf_fiiter_release(iter);
out_ok:
        kfree(fname);

        return ret;
}

static struct dentry *udf_lookup(struct inode *dir, struct dentry *dentry,
                                 unsigned int flags)
{
        struct inode *inode = NULL;
        struct udf_fileident_iter iter;
        int err;

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

        err = udf_fiiter_find_entry(dir, &dentry->d_name, &iter);
        if (err < 0 && err != -ENOENT)
                return ERR_PTR(err);

        if (err == 0) {
                struct kernel_lb_addr loc;

                loc = lelb_to_cpu(iter.fi.icb.extLocation);
                udf_fiiter_release(&iter);

                inode = udf_iget(dir->i_sb, &loc);
        }

        return d_splice_alias(inode, dentry);
}

static int udf_expand_dir_adinicb(struct inode *inode, udf_pblk_t *block)
{
        udf_pblk_t newblock;
        struct buffer_head *dbh = NULL;
        struct kernel_lb_addr eloc;
        struct extent_position epos;
        uint8_t alloctype;
        struct udf_inode_info *iinfo = UDF_I(inode);
        struct udf_fileident_iter iter;
        uint8_t *impuse;
        int ret;

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

        if (!inode->i_size) {
                iinfo->i_alloc_type = alloctype;
                mark_inode_dirty(inode);
                return 0;
        }

        /* alloc block, and copy data to it */
        *block = udf_new_block(inode->i_sb, inode,
                               iinfo->i_location.partitionReferenceNum,
                               iinfo->i_location.logicalBlockNum, &ret);
        if (!(*block))
                return ret;
        newblock = udf_get_pblock(inode->i_sb, *block,
                                  iinfo->i_location.partitionReferenceNum,
                                0);
        if (newblock == 0xffffffff)
                return -EFSCORRUPTED;
        dbh = sb_getblk(inode->i_sb, newblock);
        if (!dbh)
                return -ENOMEM;
        lock_buffer(dbh);
        memcpy(dbh->b_data, iinfo->i_data, inode->i_size);
        memset(dbh->b_data + inode->i_size, 0,
               inode->i_sb->s_blocksize - inode->i_size);
        set_buffer_uptodate(dbh);
        unlock_buffer(dbh);

        /* Drop inline data, add block instead */
        iinfo->i_alloc_type = alloctype;
        memset(iinfo->i_data + iinfo->i_lenEAttr, 0, iinfo->i_lenAlloc);
        iinfo->i_lenAlloc = 0;
        eloc.logicalBlockNum = *block;
        eloc.partitionReferenceNum =
                                iinfo->i_location.partitionReferenceNum;
        iinfo->i_lenExtents = inode->i_size;
        epos.bh = NULL;
        epos.block = iinfo->i_location;
        epos.offset = udf_file_entry_alloc_offset(inode);
        ret = udf_add_aext(inode, &epos, &eloc, inode->i_size, 0);
        brelse(epos.bh);
        if (ret < 0) {
                brelse(dbh);
                udf_free_blocks(inode->i_sb, inode, &eloc, 0, 1);
                return ret;
        }
        mark_inode_dirty(inode);

        /* Now fixup tags in moved directory entries */
        for (ret = udf_fiiter_init(&iter, inode, 0);
             !ret && iter.pos < inode->i_size;
             ret = udf_fiiter_advance(&iter)) {
                iter.fi.descTag.tagLocation = cpu_to_le32(*block);
                if (iter.fi.lengthOfImpUse != cpu_to_le16(0))
                        impuse = dbh->b_data + iter.pos +
                                                sizeof(struct fileIdentDesc);
                else
                        impuse = NULL;
                udf_fiiter_write_fi(&iter, impuse);
        }
        brelse(dbh);
        /*
         * We don't expect the iteration to fail as the directory has been
         * already verified to be correct
         */
        WARN_ON_ONCE(ret);
        udf_fiiter_release(&iter);

        return 0;
}

static int udf_fiiter_add_entry(struct inode *dir, struct dentry *dentry,
                                struct udf_fileident_iter *iter)
{
        struct udf_inode_info *dinfo = UDF_I(dir);
        int nfidlen, namelen = 0;
        int ret;
        int off, blksize = 1 << dir->i_blkbits;
        udf_pblk_t block;
        char name[UDF_NAME_LEN_CS0];

        if (dentry) {
                namelen = udf_put_filename(dir->i_sb, dentry->d_name.name,
                                           dentry->d_name.len,
                                           name, UDF_NAME_LEN_CS0);
                if (!namelen)
                        return -ENAMETOOLONG;
        }
        nfidlen = ALIGN(sizeof(struct fileIdentDesc) + namelen, UDF_NAME_PAD);

        for (ret = udf_fiiter_init(iter, dir, 0);
             !ret && iter->pos < dir->i_size;
             ret = udf_fiiter_advance(iter)) {
                if (iter->fi.fileCharacteristics & FID_FILE_CHAR_DELETED) {
                        if (udf_dir_entry_len(&iter->fi) == nfidlen) {
                                iter->fi.descTag.tagSerialNum = cpu_to_le16(1);
                                iter->fi.fileVersionNum = cpu_to_le16(1);
                                iter->fi.fileCharacteristics = 0;
                                iter->fi.lengthFileIdent = namelen;
                                iter->fi.lengthOfImpUse = cpu_to_le16(0);
                                memcpy(iter->namebuf, name, namelen);
                                iter->name = iter->namebuf;
                                return 0;
                        }
                }
        }
        if (ret) {
                udf_fiiter_release(iter);
                return ret;
        }
        if (dinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB &&
            blksize - udf_ext0_offset(dir) - iter->pos < nfidlen) {
                udf_fiiter_release(iter);
                ret = udf_expand_dir_adinicb(dir, &block);
                if (ret)
                        return ret;
                ret = udf_fiiter_init(iter, dir, dir->i_size);
                if (ret < 0)
                        return ret;
        }

        /* Get blocknumber to use for entry tag */
        if (dinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
                block = dinfo->i_location.logicalBlockNum;
        } else {
                block = iter->eloc.logicalBlockNum +
                                ((iter->elen - 1) >> dir->i_blkbits);
        }
        off = iter->pos & (blksize - 1);
        if (!off)
                off = blksize;
        /* Entry fits into current block? */
        if (blksize - udf_ext0_offset(dir) - off >= nfidlen)
                goto store_fi;

        ret = udf_fiiter_append_blk(iter);
        if (ret) {
                udf_fiiter_release(iter);
                return ret;
        }

        /* Entry will be completely in the new block? Update tag location... */
        if (!(iter->pos & (blksize - 1)))
                block = iter->eloc.logicalBlockNum +
                                ((iter->elen - 1) >> dir->i_blkbits);
store_fi:
        memset(&iter->fi, 0, sizeof(struct fileIdentDesc));
        if (UDF_SB(dir->i_sb)->s_udfrev >= 0x0200)
                udf_new_tag((char *)(&iter->fi), TAG_IDENT_FID, 3, 1, block,
                            sizeof(struct tag));
        else
                udf_new_tag((char *)(&iter->fi), TAG_IDENT_FID, 2, 1, block,
                            sizeof(struct tag));
        iter->fi.fileVersionNum = cpu_to_le16(1);
        iter->fi.lengthFileIdent = namelen;
        iter->fi.lengthOfImpUse = cpu_to_le16(0);
        memcpy(iter->namebuf, name, namelen);
        iter->name = iter->namebuf;

        dir->i_size += nfidlen;
        if (dinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
                dinfo->i_lenAlloc += nfidlen;
        } else {
                /* Truncate last extent to proper size */
                udf_fiiter_update_elen(iter, iter->elen -
                                        (dinfo->i_lenExtents - dir->i_size));
        }
        mark_inode_dirty(dir);

        return 0;
}

static void udf_fiiter_delete_entry(struct udf_fileident_iter *iter)
{
        iter->fi.fileCharacteristics |= FID_FILE_CHAR_DELETED;

        if (UDF_QUERY_FLAG(iter->dir->i_sb, UDF_FLAG_STRICT))
                memset(&iter->fi.icb, 0x00, sizeof(struct long_ad));

        udf_fiiter_write_fi(iter, NULL);
}

static void udf_add_fid_counter(struct super_block *sb, bool dir, int val)
{
        struct logicalVolIntegrityDescImpUse *lvidiu = udf_sb_lvidiu(sb);

        if (!lvidiu)
                return;
        mutex_lock(&UDF_SB(sb)->s_alloc_mutex);
        if (dir)
                le32_add_cpu(&lvidiu->numDirs, val);
        else
                le32_add_cpu(&lvidiu->numFiles, val);
        udf_updated_lvid(sb);
        mutex_unlock(&UDF_SB(sb)->s_alloc_mutex);
}

static int udf_add_nondir(struct dentry *dentry, struct inode *inode)
{
        struct udf_inode_info *iinfo = UDF_I(inode);
        struct inode *dir = d_inode(dentry->d_parent);
        struct udf_fileident_iter iter;
        int err;

        err = udf_fiiter_add_entry(dir, dentry, &iter);
        if (err) {
                inode_dec_link_count(inode);
                discard_new_inode(inode);
                return err;
        }
        iter.fi.icb.extLength = cpu_to_le32(inode->i_sb->s_blocksize);
        iter.fi.icb.extLocation = cpu_to_lelb(iinfo->i_location);
        *(__le32 *)((struct allocDescImpUse *)iter.fi.icb.impUse)->impUse =
                cpu_to_le32(iinfo->i_unique & 0x00000000FFFFFFFFUL);
        udf_fiiter_write_fi(&iter, NULL);
        inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir));
        mark_inode_dirty(dir);
        udf_fiiter_release(&iter);
        udf_add_fid_counter(dir->i_sb, false, 1);
        d_instantiate_new(dentry, inode);

        return 0;
}

static int udf_create(struct mnt_idmap *idmap, struct inode *dir,
                      struct dentry *dentry, umode_t mode, bool excl)
{
        struct inode *inode = udf_new_inode(dir, mode);

        if (IS_ERR(inode))
                return PTR_ERR(inode);

        inode->i_data.a_ops = &udf_aops;
        inode->i_op = &udf_file_inode_operations;
        inode->i_fop = &udf_file_operations;
        mark_inode_dirty(inode);

        return udf_add_nondir(dentry, inode);
}

static int udf_tmpfile(struct mnt_idmap *idmap, struct inode *dir,
                       struct file *file, umode_t mode)
{
        struct inode *inode = udf_new_inode(dir, mode);

        if (IS_ERR(inode))
                return PTR_ERR(inode);

        inode->i_data.a_ops = &udf_aops;
        inode->i_op = &udf_file_inode_operations;
        inode->i_fop = &udf_file_operations;
        mark_inode_dirty(inode);
        d_tmpfile(file, inode);
        unlock_new_inode(inode);
        return finish_open_simple(file, 0);
}

static int udf_mknod(struct mnt_idmap *idmap, struct inode *dir,
                     struct dentry *dentry, umode_t mode, dev_t rdev)
{
        struct inode *inode;

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

        inode = udf_new_inode(dir, mode);
        if (IS_ERR(inode))
                return PTR_ERR(inode);

        init_special_inode(inode, mode, rdev);
        return udf_add_nondir(dentry, inode);
}

static struct dentry *udf_mkdir(struct mnt_idmap *idmap, struct inode *dir,
                                struct dentry *dentry, umode_t mode)
{
        struct inode *inode;
        struct udf_fileident_iter iter;
        int err;
        struct udf_inode_info *dinfo = UDF_I(dir);
        struct udf_inode_info *iinfo;

        inode = udf_new_inode(dir, S_IFDIR | mode);
        if (IS_ERR(inode))
                return ERR_CAST(inode);

        iinfo = UDF_I(inode);
        inode->i_op = &udf_dir_inode_operations;
        inode->i_fop = &udf_dir_operations;
        err = udf_fiiter_add_entry(inode, NULL, &iter);
        if (err) {
                clear_nlink(inode);
                discard_new_inode(inode);
                return ERR_PTR(err);
        }
        set_nlink(inode, 2);
        iter.fi.icb.extLength = cpu_to_le32(inode->i_sb->s_blocksize);
        iter.fi.icb.extLocation = cpu_to_lelb(dinfo->i_location);
        *(__le32 *)((struct allocDescImpUse *)iter.fi.icb.impUse)->impUse =
                cpu_to_le32(dinfo->i_unique & 0x00000000FFFFFFFFUL);
        iter.fi.fileCharacteristics =
                        FID_FILE_CHAR_DIRECTORY | FID_FILE_CHAR_PARENT;
        udf_fiiter_write_fi(&iter, NULL);
        udf_fiiter_release(&iter);
        mark_inode_dirty(inode);

        err = udf_fiiter_add_entry(dir, dentry, &iter);
        if (err) {
                clear_nlink(inode);
                discard_new_inode(inode);
                return ERR_PTR(err);
        }
        iter.fi.icb.extLength = cpu_to_le32(inode->i_sb->s_blocksize);
        iter.fi.icb.extLocation = cpu_to_lelb(iinfo->i_location);
        *(__le32 *)((struct allocDescImpUse *)iter.fi.icb.impUse)->impUse =
                cpu_to_le32(iinfo->i_unique & 0x00000000FFFFFFFFUL);
        iter.fi.fileCharacteristics |= FID_FILE_CHAR_DIRECTORY;
        udf_fiiter_write_fi(&iter, NULL);
        udf_fiiter_release(&iter);
        udf_add_fid_counter(dir->i_sb, true, 1);
        inc_nlink(dir);
        inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir));
        mark_inode_dirty(dir);
        d_instantiate_new(dentry, inode);

        return NULL;
}

static int empty_dir(struct inode *dir)
{
        struct udf_fileident_iter iter;
        int ret;

        for (ret = udf_fiiter_init(&iter, dir, 0);
             !ret && iter.pos < dir->i_size;
             ret = udf_fiiter_advance(&iter)) {
                if (iter.fi.lengthFileIdent &&
                    !(iter.fi.fileCharacteristics & FID_FILE_CHAR_DELETED)) {
                        udf_fiiter_release(&iter);
                        return 0;
                }
        }
        udf_fiiter_release(&iter);

        return 1;
}

static int udf_rmdir(struct inode *dir, struct dentry *dentry)
{
        int ret;
        struct inode *inode = d_inode(dentry);
        struct udf_fileident_iter iter;
        struct kernel_lb_addr tloc;

        ret = udf_fiiter_find_entry(dir, &dentry->d_name, &iter);
        if (ret)
                goto out;

        ret = -EFSCORRUPTED;
        tloc = lelb_to_cpu(iter.fi.icb.extLocation);
        if (udf_get_lb_pblock(dir->i_sb, &tloc, 0) != inode->i_ino)
                goto end_rmdir;
        ret = -ENOTEMPTY;
        if (!empty_dir(inode))
                goto end_rmdir;
        udf_fiiter_delete_entry(&iter);
        if (inode->i_nlink != 2)
                udf_warn(inode->i_sb, "empty directory has nlink != 2 (%u)\n",
                         inode->i_nlink);
        clear_nlink(inode);
        inode->i_size = 0;
        if (dir->i_nlink >= 3)
                inode_dec_link_count(dir);
        else
                udf_warn(inode->i_sb, "parent dir link count too low (%u)\n",
                         dir->i_nlink);
        udf_add_fid_counter(dir->i_sb, true, -1);
        inode_set_mtime_to_ts(dir,
                              inode_set_ctime_to_ts(dir, inode_set_ctime_current(inode)));
        mark_inode_dirty(dir);
        ret = 0;
end_rmdir:
        udf_fiiter_release(&iter);
out:
        return ret;
}

static int udf_unlink(struct inode *dir, struct dentry *dentry)
{
        int ret;
        struct inode *inode = d_inode(dentry);
        struct udf_fileident_iter iter;
        struct kernel_lb_addr tloc;

        ret = udf_fiiter_find_entry(dir, &dentry->d_name, &iter);
        if (ret)
                goto out;

        ret = -EFSCORRUPTED;
        tloc = lelb_to_cpu(iter.fi.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), %u\n",
                          inode->i_ino, inode->i_nlink);
                set_nlink(inode, 1);
        }
        udf_fiiter_delete_entry(&iter);
        inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir));
        mark_inode_dirty(dir);
        inode_dec_link_count(inode);
        udf_add_fid_counter(dir->i_sb, false, -1);
        inode_set_ctime_to_ts(inode, inode_get_ctime(dir));
        ret = 0;
end_unlink:
        udf_fiiter_release(&iter);
out:
        return ret;
}

static int udf_symlink(struct mnt_idmap *idmap, struct inode *dir,
                       struct dentry *dentry, const char *symname)
{
        struct inode *inode;
        struct pathComponent *pc;
        const char *compstart;
        struct extent_position epos = {};
        int eoffset, elen = 0;
        uint8_t *ea;
        int err;
        udf_pblk_t block;
        unsigned char *name = NULL;
        int namelen;
        struct udf_inode_info *iinfo;
        struct super_block *sb = dir->i_sb;

        name = kmalloc(UDF_NAME_LEN_CS0, GFP_KERNEL);
        if (!name) {
                err = -ENOMEM;
                goto out;
        }

        inode = udf_new_inode(dir, S_IFLNK | 0777);
        if (IS_ERR(inode)) {
                err = PTR_ERR(inode);
                goto out;
        }

        iinfo = UDF_I(inode);
        down_write(&iinfo->i_data_sem);
        inode->i_data.a_ops = &udf_symlink_aops;
        inode->i_op = &udf_symlink_inode_operations;
        inode_nohighmem(inode);

        if (iinfo->i_alloc_type != ICBTAG_FLAG_AD_IN_ICB) {
                struct kernel_lb_addr eloc;
                uint32_t bsize;

                block = udf_new_block(sb, inode,
                                iinfo->i_location.partitionReferenceNum,
                                iinfo->i_location.logicalBlockNum, &err);
                if (!block)
                        goto out_no_entry;
                epos.block = iinfo->i_location;
                epos.offset = udf_file_entry_alloc_offset(inode);
                epos.bh = NULL;
                eloc.logicalBlockNum = block;
                eloc.partitionReferenceNum =
                                iinfo->i_location.partitionReferenceNum;
                bsize = sb->s_blocksize;
                iinfo->i_lenExtents = bsize;
                err = udf_add_aext(inode, &epos, &eloc, bsize, 0);
                brelse(epos.bh);
                if (err < 0) {
                        udf_free_blocks(sb, inode, &eloc, 0, 1);
                        goto out_no_entry;
                }

                block = udf_get_pblock(sb, block,
                                iinfo->i_location.partitionReferenceNum,
                                0);
                epos.bh = sb_getblk(sb, block);
                if (unlikely(!epos.bh)) {
                        err = -ENOMEM;
                        udf_free_blocks(sb, inode, &eloc, 0, 1);
                        goto out_no_entry;
                }
                lock_buffer(epos.bh);
                memset(epos.bh->b_data, 0x00, bsize);
                set_buffer_uptodate(epos.bh);
                unlock_buffer(epos.bh);
                mark_buffer_dirty_inode(epos.bh, inode);
                ea = epos.bh->b_data + udf_ext0_offset(inode);
        } else
                ea = iinfo->i_data + iinfo->i_lenEAttr;

        eoffset = 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;
                elen += sizeof(struct pathComponent);
        }

        err = -ENAMETOOLONG;

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

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

                compstart = 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) {
                        namelen = udf_put_filename(sb, compstart,
                                                   symname - compstart,
                                                   name, UDF_NAME_LEN_CS0);
                        if (!namelen)
                                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 == '/');
                }
        }

        brelse(epos.bh);
        inode->i_size = elen;
        if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB)
                iinfo->i_lenAlloc = inode->i_size;
        else
                udf_truncate_tail_extent(inode);
        mark_inode_dirty(inode);
        up_write(&iinfo->i_data_sem);

        err = udf_add_nondir(dentry, inode);
out:
        kfree(name);
        return err;

out_no_entry:
        up_write(&iinfo->i_data_sem);
        inode_dec_link_count(inode);
        discard_new_inode(inode);
        goto out;
}

static int udf_link(struct dentry *old_dentry, struct inode *dir,
                    struct dentry *dentry)
{
        struct inode *inode = d_inode(old_dentry);
        struct udf_fileident_iter iter;
        int err;

        err = udf_fiiter_add_entry(dir, dentry, &iter);
        if (err)
                return err;
        iter.fi.icb.extLength = cpu_to_le32(inode->i_sb->s_blocksize);
        iter.fi.icb.extLocation = cpu_to_lelb(UDF_I(inode)->i_location);
        if (UDF_SB(inode->i_sb)->s_lvid_bh) {
                *(__le32 *)((struct allocDescImpUse *)iter.fi.icb.impUse)->impUse =
                        cpu_to_le32(lvid_get_unique_id(inode->i_sb));
        }
        udf_fiiter_write_fi(&iter, NULL);
        udf_fiiter_release(&iter);

        inc_nlink(inode);
        udf_add_fid_counter(dir->i_sb, false, 1);
        inode_set_ctime_current(inode);
        mark_inode_dirty(inode);
        inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir));
        mark_inode_dirty(dir);
        ihold(inode);
        d_instantiate(dentry, inode);

        return 0;
}

/* Anybody can rename anything with this: the permission checks are left to the
 * higher-level routines.
 */
static int udf_rename(struct mnt_idmap *idmap, struct inode *old_dir,
                      struct dentry *old_dentry, struct inode *new_dir,
                      struct dentry *new_dentry, unsigned int flags)
{
        struct inode *old_inode = d_inode(old_dentry);
        struct inode *new_inode = d_inode(new_dentry);
        struct udf_fileident_iter oiter, niter, diriter;
        bool has_diriter = false, is_dir = false;
        int retval;
        struct kernel_lb_addr tloc;

        if (flags & ~RENAME_NOREPLACE)
                return -EINVAL;

        retval = udf_fiiter_find_entry(old_dir, &old_dentry->d_name, &oiter);
        if (retval)
                return retval;

        tloc = lelb_to_cpu(oiter.fi.icb.extLocation);
        if (udf_get_lb_pblock(old_dir->i_sb, &tloc, 0) != old_inode->i_ino) {
                retval = -ENOENT;
                goto out_oiter;
        }

        if (S_ISDIR(old_inode->i_mode)) {
                if (new_inode) {
                        retval = -ENOTEMPTY;
                        if (!empty_dir(new_inode))
                                goto out_oiter;
                        retval = -EFSCORRUPTED;
                        if (new_inode->i_nlink != 2)
                                goto out_oiter;
                }
                retval = -EFSCORRUPTED;
                if (old_dir->i_nlink < 3)
                        goto out_oiter;
                is_dir = true;
        } else if (new_inode) {
                retval = -EFSCORRUPTED;
                if (new_inode->i_nlink < 1)
                        goto out_oiter;
        }
        if (is_dir && old_dir != new_dir) {
                retval = udf_fiiter_find_entry(old_inode, &dotdot_name,
                                               &diriter);
                if (retval == -ENOENT) {
                        udf_err(old_inode->i_sb,
                                "directory (ino %lu) has no '..' entry\n",
                                old_inode->i_ino);
                        retval = -EFSCORRUPTED;
                }
                if (retval)
                        goto out_oiter;
                has_diriter = true;
                tloc = lelb_to_cpu(diriter.fi.icb.extLocation);
                if (udf_get_lb_pblock(old_inode->i_sb, &tloc, 0) !=
                                old_dir->i_ino) {
                        retval = -EFSCORRUPTED;
                        udf_err(old_inode->i_sb,
                                "directory (ino %lu) has parent entry pointing to another inode (%lu != %u)\n",
                                old_inode->i_ino, old_dir->i_ino,
                                udf_get_lb_pblock(old_inode->i_sb, &tloc, 0));
                        goto out_oiter;
                }
        }

        retval = udf_fiiter_find_entry(new_dir, &new_dentry->d_name, &niter);
        if (retval && retval != -ENOENT)
                goto out_oiter;
        /* Entry found but not passed by VFS? */
        if (!retval && !new_inode) {
                retval = -EFSCORRUPTED;
                udf_fiiter_release(&niter);
                goto out_oiter;
        }
        /* Entry not found? Need to add one... */
        if (retval) {
                udf_fiiter_release(&niter);
                retval = udf_fiiter_add_entry(new_dir, new_dentry, &niter);
                if (retval)
                        goto out_oiter;
        }

        /*
         * Like most other Unix systems, set the ctime for inodes on a
         * rename.
         */
        inode_set_ctime_current(old_inode);
        mark_inode_dirty(old_inode);

        /*
         * ok, that's it
         */
        niter.fi.fileVersionNum = oiter.fi.fileVersionNum;
        niter.fi.fileCharacteristics = oiter.fi.fileCharacteristics;
        memcpy(&(niter.fi.icb), &(oiter.fi.icb), sizeof(oiter.fi.icb));
        udf_fiiter_write_fi(&niter, NULL);
        udf_fiiter_release(&niter);

        /*
         * The old entry may have moved due to new entry allocation. Find it
         * again.
         */
        udf_fiiter_release(&oiter);
        retval = udf_fiiter_find_entry(old_dir, &old_dentry->d_name, &oiter);
        if (retval) {
                udf_err(old_dir->i_sb,
                        "failed to find renamed entry again in directory (ino %lu)\n",
                        old_dir->i_ino);
        } else {
                udf_fiiter_delete_entry(&oiter);
                udf_fiiter_release(&oiter);
        }

        if (new_inode) {
                inode_set_ctime_current(new_inode);
                inode_dec_link_count(new_inode);
                udf_add_fid_counter(old_dir->i_sb, S_ISDIR(new_inode->i_mode),
                                    -1);
        }
        inode_set_mtime_to_ts(old_dir, inode_set_ctime_current(old_dir));
        inode_set_mtime_to_ts(new_dir, inode_set_ctime_current(new_dir));
        mark_inode_dirty(old_dir);
        mark_inode_dirty(new_dir);

        if (has_diriter) {
                diriter.fi.icb.extLocation =
                                        cpu_to_lelb(UDF_I(new_dir)->i_location);
                udf_fiiter_write_fi(&diriter, NULL);
                udf_fiiter_release(&diriter);
        }

        if (is_dir) {
                inode_dec_link_count(old_dir);
                if (new_inode)
                        inode_dec_link_count(new_inode);
                else {
                        inc_nlink(new_dir);
                        mark_inode_dirty(new_dir);
                }
        }
        return 0;
out_oiter:
        if (has_diriter)
                udf_fiiter_release(&diriter);
        udf_fiiter_release(&oiter);

        return retval;
}

static struct dentry *udf_get_parent(struct dentry *child)
{
        struct kernel_lb_addr tloc;
        struct udf_fileident_iter iter;
        int err;

        err = udf_fiiter_find_entry(d_inode(child), &dotdot_name, &iter);
        if (err)
                return ERR_PTR(err);

        tloc = lelb_to_cpu(iter.fi.icb.extLocation);
        udf_fiiter_release(&iter);
        return d_obtain_alias(udf_iget(child->d_sb, &tloc));
}


static struct dentry *udf_nfs_get_inode(struct super_block *sb, u32 block,
                                        u16 partref, __u32 generation)
{
        struct inode *inode;
        struct kernel_lb_addr loc;

        if (block == 0)
                return ERR_PTR(-ESTALE);

        loc.logicalBlockNum = block;
        loc.partitionReferenceNum = partref;
        inode = udf_iget(sb, &loc);

        if (IS_ERR(inode))
                return ERR_CAST(inode);

        if (generation && inode->i_generation != generation) {
                iput(inode);
                return ERR_PTR(-ESTALE);
        }
        return d_obtain_alias(inode);
}

static struct dentry *udf_fh_to_dentry(struct super_block *sb,
                                       struct fid *fid, int fh_len, int fh_type)
{
        if (fh_len < 3 ||
            (fh_type != FILEID_UDF_WITH_PARENT &&
             fh_type != FILEID_UDF_WITHOUT_PARENT))
                return NULL;

        return udf_nfs_get_inode(sb, fid->udf.block, fid->udf.partref,
                        fid->udf.generation);
}

static struct dentry *udf_fh_to_parent(struct super_block *sb,
                                       struct fid *fid, int fh_len, int fh_type)
{
        if (fh_len < 5 || fh_type != FILEID_UDF_WITH_PARENT)
                return NULL;

        return udf_nfs_get_inode(sb, fid->udf.parent_block,
                                 fid->udf.parent_partref,
                                 fid->udf.parent_generation);
}
static int udf_encode_fh(struct inode *inode, __u32 *fh, int *lenp,
                         struct inode *parent)
{
        int len = *lenp;
        struct kernel_lb_addr location = UDF_I(inode)->i_location;
        struct fid *fid = (struct fid *)fh;
        int type = FILEID_UDF_WITHOUT_PARENT;

        if (parent && (len < 5)) {
                *lenp = 5;
                return FILEID_INVALID;
        } else if (len < 3) {
                *lenp = 3;
                return FILEID_INVALID;
        }

        *lenp = 3;
        fid->udf.block = location.logicalBlockNum;
        fid->udf.partref = location.partitionReferenceNum;
        fid->udf.parent_partref = 0;
        fid->udf.generation = inode->i_generation;

        if (parent) {
                location = UDF_I(parent)->i_location;
                fid->udf.parent_block = location.logicalBlockNum;
                fid->udf.parent_partref = location.partitionReferenceNum;
                fid->udf.parent_generation = inode->i_generation;
                *lenp = 5;
                type = FILEID_UDF_WITH_PARENT;
        }

        return type;
}

const struct export_operations udf_export_ops = {
        .encode_fh      = udf_encode_fh,
        .fh_to_dentry   = udf_fh_to_dentry,
        .fh_to_parent   = udf_fh_to_parent,
        .get_parent     = udf_get_parent,
};

const 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,
        .tmpfile                        = udf_tmpfile,
};