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root/fs/udf/directory.c

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DEFINITIONS

This source file includes following definitions.
  1. udf_filead_read
  2. udf_fileident_read
  3. udf_get_fileident
  4. udf_get_fileextent
  5. udf_get_fileshortad
  6. udf_get_filelongad

/*
 * directory.c
 *
 * PURPOSE
 *      Directory related functions
 *
 * 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.
 */

#include "udfdecl.h"
#include "udf_i.h"

#include <linux/fs.h>
#include <linux/string.h>
#include <linux/buffer_head.h>

#if 0
static uint8_t *udf_filead_read(struct inode *dir, uint8_t *tmpad,
                                uint8_t ad_size, kernel_lb_addr fe_loc,
                                int *pos, int *offset, struct buffer_head **bh,
                                int *error)
{
        int loffset = *offset;
        int block;
        uint8_t *ad;
        int remainder;

        *error = 0;

        ad = (uint8_t *)(*bh)->b_data + *offset;
        *offset += ad_size;

        if (!ad) {
                brelse(*bh);
                *error = 1;
                return NULL;
        }

        if (*offset == dir->i_sb->s_blocksize) {
                brelse(*bh);
                block = udf_get_lb_pblock(dir->i_sb, fe_loc, ++*pos);
                if (!block)
                        return NULL;
                *bh = udf_tread(dir->i_sb, block);
                if (!*bh)
                        return NULL;
        } else if (*offset > dir->i_sb->s_blocksize) {
                ad = tmpad;

                remainder = dir->i_sb->s_blocksize - loffset;
                memcpy((uint8_t *)ad, (*bh)->b_data + loffset, remainder);

                brelse(*bh);
                block = udf_get_lb_pblock(dir->i_sb, fe_loc, ++*pos);
                if (!block)
                        return NULL;
                (*bh) = udf_tread(dir->i_sb, block);
                if (!*bh)
                        return NULL;

                memcpy((uint8_t *)ad + remainder, (*bh)->b_data,
                        ad_size - remainder);
                *offset = ad_size - remainder;
        }

        return ad;
}
#endif

struct fileIdentDesc *udf_fileident_read(struct inode *dir, loff_t *nf_pos,
                                         struct udf_fileident_bh *fibh,
                                         struct fileIdentDesc *cfi,
                                         struct extent_position *epos,
                                         kernel_lb_addr *eloc, uint32_t *elen,
                                         sector_t *offset)
{
        struct fileIdentDesc *fi;
        int i, num, block;
        struct buffer_head *tmp, *bha[16];
        struct udf_inode_info *iinfo = UDF_I(dir);

        fibh->soffset = fibh->eoffset;

        if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
                fi = udf_get_fileident(iinfo->i_ext.i_data -
                                       (iinfo->i_efe ?
                                        sizeof(struct extendedFileEntry) :
                                        sizeof(struct fileEntry)),
                                       dir->i_sb->s_blocksize,
                                       &(fibh->eoffset));
                if (!fi)
                        return NULL;

                *nf_pos += fibh->eoffset - fibh->soffset;

                memcpy((uint8_t *)cfi, (uint8_t *)fi,
                       sizeof(struct fileIdentDesc));

                return fi;
        }

        if (fibh->eoffset == dir->i_sb->s_blocksize) {
                int lextoffset = epos->offset;
                unsigned char blocksize_bits = dir->i_sb->s_blocksize_bits;

                if (udf_next_aext(dir, epos, eloc, elen, 1) !=
                    (EXT_RECORDED_ALLOCATED >> 30))
                        return NULL;

                block = udf_get_lb_pblock(dir->i_sb, *eloc, *offset);

                (*offset)++;

                if ((*offset << blocksize_bits) >= *elen)
                        *offset = 0;
                else
                        epos->offset = lextoffset;

                brelse(fibh->sbh);
                fibh->sbh = fibh->ebh = udf_tread(dir->i_sb, block);
                if (!fibh->sbh)
                        return NULL;
                fibh->soffset = fibh->eoffset = 0;

                if (!(*offset & ((16 >> (blocksize_bits - 9)) - 1))) {
                        i = 16 >> (blocksize_bits - 9);
                        if (i + *offset > (*elen >> blocksize_bits))
                                i = (*elen >> blocksize_bits)-*offset;
                        for (num = 0; i > 0; i--) {
                                block = udf_get_lb_pblock(dir->i_sb, *eloc,
                                                          *offset + i);
                                tmp = udf_tgetblk(dir->i_sb, block);
                                if (tmp && !buffer_uptodate(tmp) &&
                                                !buffer_locked(tmp))
                                        bha[num++] = tmp;
                                else
                                        brelse(tmp);
                        }
                        if (num) {
                                ll_rw_block(READA, num, bha);
                                for (i = 0; i < num; i++)
                                        brelse(bha[i]);
                        }
                }
        } else if (fibh->sbh != fibh->ebh) {
                brelse(fibh->sbh);
                fibh->sbh = fibh->ebh;
        }

        fi = udf_get_fileident(fibh->sbh->b_data, dir->i_sb->s_blocksize,
                               &(fibh->eoffset));

        if (!fi)
                return NULL;

        *nf_pos += fibh->eoffset - fibh->soffset;

        if (fibh->eoffset <= dir->i_sb->s_blocksize) {
                memcpy((uint8_t *)cfi, (uint8_t *)fi,
                       sizeof(struct fileIdentDesc));
        } else if (fibh->eoffset > dir->i_sb->s_blocksize) {
                int lextoffset = epos->offset;

                if (udf_next_aext(dir, epos, eloc, elen, 1) !=
                    (EXT_RECORDED_ALLOCATED >> 30))
                        return NULL;

                block = udf_get_lb_pblock(dir->i_sb, *eloc, *offset);

                (*offset)++;

                if ((*offset << dir->i_sb->s_blocksize_bits) >= *elen)
                        *offset = 0;
                else
                        epos->offset = lextoffset;

                fibh->soffset -= dir->i_sb->s_blocksize;
                fibh->eoffset -= dir->i_sb->s_blocksize;

                fibh->ebh = udf_tread(dir->i_sb, block);
                if (!fibh->ebh)
                        return NULL;

                if (sizeof(struct fileIdentDesc) > -fibh->soffset) {
                        int fi_len;

                        memcpy((uint8_t *)cfi, (uint8_t *)fi, -fibh->soffset);
                        memcpy((uint8_t *)cfi - fibh->soffset,
                               fibh->ebh->b_data,
                               sizeof(struct fileIdentDesc) + fibh->soffset);

                        fi_len = (sizeof(struct fileIdentDesc) +
                                  cfi->lengthFileIdent +
                                  le16_to_cpu(cfi->lengthOfImpUse) + 3) & ~3;

                        *nf_pos += fi_len - (fibh->eoffset - fibh->soffset);
                        fibh->eoffset = fibh->soffset + fi_len;
                } else {
                        memcpy((uint8_t *)cfi, (uint8_t *)fi,
                               sizeof(struct fileIdentDesc));
                }
        }
        return fi;
}

struct fileIdentDesc *udf_get_fileident(void *buffer, int bufsize, int *offset)
{
        struct fileIdentDesc *fi;
        int lengthThisIdent;
        uint8_t *ptr;
        int padlen;

        if ((!buffer) || (!offset)) {
                udf_debug("invalidparms\n, buffer=%p, offset=%p\n", buffer,
                          offset);
                return NULL;
        }

        ptr = buffer;

        if ((*offset > 0) && (*offset < bufsize))
                ptr += *offset;
        fi = (struct fileIdentDesc *)ptr;
        if (fi->descTag.tagIdent != cpu_to_le16(TAG_IDENT_FID)) {
                udf_debug("0x%x != TAG_IDENT_FID\n",
                          le16_to_cpu(fi->descTag.tagIdent));
                udf_debug("offset: %u sizeof: %lu bufsize: %u\n",
                          *offset, (unsigned long)sizeof(struct fileIdentDesc),
                          bufsize);
                return NULL;
        }
        if ((*offset + sizeof(struct fileIdentDesc)) > bufsize)
                lengthThisIdent = sizeof(struct fileIdentDesc);
        else
                lengthThisIdent = sizeof(struct fileIdentDesc) +
                        fi->lengthFileIdent + le16_to_cpu(fi->lengthOfImpUse);

        /* we need to figure padding, too! */
        padlen = lengthThisIdent % UDF_NAME_PAD;
        if (padlen)
                lengthThisIdent += (UDF_NAME_PAD - padlen);
        *offset = *offset + lengthThisIdent;

        return fi;
}

#if 0
static extent_ad *udf_get_fileextent(void *buffer, int bufsize, int *offset)
{
        extent_ad *ext;
        struct fileEntry *fe;
        uint8_t *ptr;

        if ((!buffer) || (!offset)) {
                printk(KERN_ERR "udf: udf_get_fileextent() invalidparms\n");
                return NULL;
        }

        fe = (struct fileEntry *)buffer;

        if (fe->descTag.tagIdent != cpu_to_le16(TAG_IDENT_FE)) {
                udf_debug("0x%x != TAG_IDENT_FE\n",
                          le16_to_cpu(fe->descTag.tagIdent));
                return NULL;
        }

        ptr = (uint8_t *)(fe->extendedAttr) +
                le32_to_cpu(fe->lengthExtendedAttr);

        if ((*offset > 0) && (*offset < le32_to_cpu(fe->lengthAllocDescs)))
                ptr += *offset;

        ext = (extent_ad *)ptr;

        *offset = *offset + sizeof(extent_ad);
        return ext;
}
#endif

short_ad *udf_get_fileshortad(uint8_t *ptr, int maxoffset, uint32_t *offset,
                              int inc)
{
        short_ad *sa;

        if ((!ptr) || (!offset)) {
                printk(KERN_ERR "udf: udf_get_fileshortad() invalidparms\n");
                return NULL;
        }

        if ((*offset + sizeof(short_ad)) > maxoffset)
                return NULL;
        else {
                sa = (short_ad *)ptr;
                if (sa->extLength == 0)
                        return NULL;
        }

        if (inc)
                *offset += sizeof(short_ad);
        return sa;
}

long_ad *udf_get_filelongad(uint8_t *ptr, int maxoffset, uint32_t *offset, int inc)
{
        long_ad *la;

        if ((!ptr) || (!offset)) {
                printk(KERN_ERR "udf: udf_get_filelongad() invalidparms\n");
                return NULL;
        }

        if ((*offset + sizeof(long_ad)) > maxoffset)
                return NULL;
        else {
                la = (long_ad *)ptr;
                if (la->extLength == 0)
                        return NULL;
        }

        if (inc)
                *offset += sizeof(long_ad);
        return la;
}

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