fs/udf/directory.c

   1 /*
   2  * directory.c
   3  *
   4  * PURPOSE
   5  *      Directory related functions
   6  *
   7  * COPYRIGHT
   8  *      This file is distributed under the terms of the GNU General Public
   9  *      License (GPL). Copies of the GPL can be obtained from:
  10  *              ftp://prep.ai.mit.edu/pub/gnu/GPL
  11  *      Each contributing author retains all rights to their own work.
  12  */
  13
  14 #include "udfdecl.h"
  15 #include "udf_i.h"
  16
  17 #include <linux/fs.h>
  18 #include <linux/string.h>
  19 #include <linux/buffer_head.h>
  20
  21 #if 0
  22 static uint8_t *udf_filead_read(struct inode *dir, uint8_t *tmpad,
  23                                 uint8_t ad_size, kernel_lb_addr fe_loc,
  24                                 int *pos, int *offset, struct buffer_head **bh,
  25                                 int *error)
  26 {
  27         int loffset = *offset;
  28         int block;
  29         uint8_t *ad;
  30         int remainder;
  31
  32         *error = 0;
  33
  34         ad = (uint8_t *)(*bh)->b_data + *offset;
  35         *offset += ad_size;
  36
  37         if (!ad) {
  38                 brelse(*bh);
  39                 *error = 1;
  40                 return NULL;
  41         }
  42
  43         if (*offset == dir->i_sb->s_blocksize) {
  44                 brelse(*bh);
  45                 block = udf_get_lb_pblock(dir->i_sb, fe_loc, ++*pos);
  46                 if (!block)
  47                         return NULL;
  48                 *bh = udf_tread(dir->i_sb, block);
  49                 if (!*bh)
  50                         return NULL;
  51         } else if (*offset > dir->i_sb->s_blocksize) {
  52                 ad = tmpad;
  53
  54                 remainder = dir->i_sb->s_blocksize - loffset;
  55                 memcpy((uint8_t *)ad, (*bh)->b_data + loffset, remainder);
  56
  57                 brelse(*bh);
  58                 block = udf_get_lb_pblock(dir->i_sb, fe_loc, ++*pos);
  59                 if (!block)
  60                         return NULL;
  61                 (*bh) = udf_tread(dir->i_sb, block);
  62                 if (!*bh)
  63                         return NULL;
  64
  65                 memcpy((uint8_t *)ad + remainder, (*bh)->b_data,
  66                         ad_size - remainder);
  67                 *offset = ad_size - remainder;
  68         }
  69
  70         return ad;
  71 }
  72 #endif
  73
  74 struct fileIdentDesc *udf_fileident_read(struct inode *dir, loff_t *nf_pos,
  75                                          struct udf_fileident_bh *fibh,
  76                                          struct fileIdentDesc *cfi,
  77                                          struct extent_position *epos,
  78                                          kernel_lb_addr *eloc, uint32_t *elen,
  79                                          sector_t *offset)
  80 {
  81         struct fileIdentDesc *fi;
  82         int i, num, block;
  83         struct buffer_head *tmp, *bha[16];
  84
  85         fibh->soffset = fibh->eoffset;
  86
  87         if (UDF_I(dir)->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
  88                 fi = udf_get_fileident(UDF_I(dir)->i_ext.i_data -
  89                                        (UDF_I(dir)->i_efe ?
  90                                         sizeof(struct extendedFileEntry) :
  91                                         sizeof(struct fileEntry)),
  92                                        dir->i_sb->s_blocksize,
  93                                        &(fibh->eoffset));
  94                 if (!fi)
  95                         return NULL;
  96
  97                 *nf_pos += ((fibh->eoffset - fibh->soffset) >> 2);
  98
  99                 memcpy((uint8_t *)cfi, (uint8_t *)fi,
 100                        sizeof(struct fileIdentDesc));
 101
 102                 return fi;
 103         }
 104
 105         if (fibh->eoffset == dir->i_sb->s_blocksize) {
 106                 int lextoffset = epos->offset;
 107                 unsigned char blocksize_bits = dir->i_sb->s_blocksize_bits;
 108
 109                 if (udf_next_aext(dir, epos, eloc, elen, 1) !=
 110                     (EXT_RECORDED_ALLOCATED >> 30))
 111                         return NULL;
 112
 113                 block = udf_get_lb_pblock(dir->i_sb, *eloc, *offset);
 114
 115                 (*offset)++;
 116
 117                 if ((*offset << blocksize_bits) >= *elen)
 118                         *offset = 0;
 119                 else
 120                         epos->offset = lextoffset;
 121
 122                 brelse(fibh->sbh);
 123                 fibh->sbh = fibh->ebh = udf_tread(dir->i_sb, block);
 124                 if (!fibh->sbh)
 125                         return NULL;
 126                 fibh->soffset = fibh->eoffset = 0;
 127
 128                 if (!(*offset & ((16 >> (blocksize_bits - 9)) - 1))) {
 129                         i = 16 >> (blocksize_bits - 9);
 130                         if (i + *offset > (*elen >> blocksize_bits))
 131                                 i = (*elen >> blocksize_bits)-*offset;
 132                         for (num = 0; i > 0; i--) {
 133                                 block = udf_get_lb_pblock(dir->i_sb, *eloc,
 134                                                           *offset + i);
 135                                 tmp = udf_tgetblk(dir->i_sb, block);
 136                                 if (tmp && !buffer_uptodate(tmp) &&
 137                                                 !buffer_locked(tmp))
 138                                         bha[num++] = tmp;
 139                                 else
 140                                         brelse(tmp);
 141                         }
 142                         if (num) {
 143                                 ll_rw_block(READA, num, bha);
 144                                 for (i = 0; i < num; i++)
 145                                         brelse(bha[i]);
 146                         }
 147                 }
 148         } else if (fibh->sbh != fibh->ebh) {
 149                 brelse(fibh->sbh);
 150                 fibh->sbh = fibh->ebh;
 151         }
 152
 153         fi = udf_get_fileident(fibh->sbh->b_data, dir->i_sb->s_blocksize,
 154                                &(fibh->eoffset));
 155
 156         if (!fi)
 157                 return NULL;
 158
 159         *nf_pos += ((fibh->eoffset - fibh->soffset) >> 2);
 160
 161         if (fibh->eoffset <= dir->i_sb->s_blocksize) {
 162                 memcpy((uint8_t *)cfi, (uint8_t *)fi,
 163                        sizeof(struct fileIdentDesc));
 164         } else if (fibh->eoffset > dir->i_sb->s_blocksize) {
 165                 int lextoffset = epos->offset;
 166
 167                 if (udf_next_aext(dir, epos, eloc, elen, 1) !=
 168                     (EXT_RECORDED_ALLOCATED >> 30))
 169                         return NULL;
 170
 171                 block = udf_get_lb_pblock(dir->i_sb, *eloc, *offset);
 172
 173                 (*offset)++;
 174
 175                 if ((*offset << dir->i_sb->s_blocksize_bits) >= *elen)
 176                         *offset = 0;
 177                 else
 178                         epos->offset = lextoffset;
 179
 180                 fibh->soffset -= dir->i_sb->s_blocksize;
 181                 fibh->eoffset -= dir->i_sb->s_blocksize;
 182
 183                 fibh->ebh = udf_tread(dir->i_sb, block);
 184                 if (!fibh->ebh)
 185                         return NULL;
 186
 187                 if (sizeof(struct fileIdentDesc) > -fibh->soffset) {
 188                         int fi_len;
 189
 190                         memcpy((uint8_t *)cfi, (uint8_t *)fi, -fibh->soffset);
 191                         memcpy((uint8_t *)cfi - fibh->soffset,
 192                                fibh->ebh->b_data,
 193                                sizeof(struct fileIdentDesc) + fibh->soffset);
 194
 195                         fi_len = (sizeof(struct fileIdentDesc) +
 196                                   cfi->lengthFileIdent +
 197                                   le16_to_cpu(cfi->lengthOfImpUse) + 3) & ~3;
 198
 199                         *nf_pos += (fi_len - (fibh->eoffset - fibh->soffset))
 200                                         >> 2;
 201                         fibh->eoffset = fibh->soffset + fi_len;
 202                 } else {
 203                         memcpy((uint8_t *)cfi, (uint8_t *)fi,
 204                                sizeof(struct fileIdentDesc));
 205                 }
 206         }
 207         return fi;
 208 }
 209
 210 struct fileIdentDesc *udf_get_fileident(void *buffer, int bufsize, int *offset)
 211 {
 212         struct fileIdentDesc *fi;
 213         int lengthThisIdent;
 214         uint8_t *ptr;
 215         int padlen;
 216
 217         if ((!buffer) || (!offset)) {
 218                 udf_debug("invalidparms\n, buffer=%p, offset=%p\n", buffer,
 219                           offset);
 220                 return NULL;
 221         }
 222
 223         ptr = buffer;
 224
 225         if ((*offset > 0) && (*offset < bufsize))
 226                 ptr += *offset;
 227         fi = (struct fileIdentDesc *)ptr;
 228         if (fi->descTag.tagIdent != cpu_to_le16(TAG_IDENT_FID)) {
 229                 udf_debug("0x%x != TAG_IDENT_FID\n",
 230                           le16_to_cpu(fi->descTag.tagIdent));
 231                 udf_debug("offset: %u sizeof: %lu bufsize: %u\n",
 232                           *offset, (unsigned long)sizeof(struct fileIdentDesc),
 233                           bufsize);
 234                 return NULL;
 235         }
 236         if ((*offset + sizeof(struct fileIdentDesc)) > bufsize)
 237                 lengthThisIdent = sizeof(struct fileIdentDesc);
 238         else
 239                 lengthThisIdent = sizeof(struct fileIdentDesc) +
 240                         fi->lengthFileIdent + le16_to_cpu(fi->lengthOfImpUse);
 241
 242         /* we need to figure padding, too! */
 243         padlen = lengthThisIdent % UDF_NAME_PAD;
 244         if (padlen)
 245                 lengthThisIdent += (UDF_NAME_PAD - padlen);
 246         *offset = *offset + lengthThisIdent;
 247
 248         return fi;
 249 }
 250
 251 #if 0
 252 static extent_ad *udf_get_fileextent(void *buffer, int bufsize, int *offset)
 253 {
 254         extent_ad *ext;
 255         struct fileEntry *fe;
 256         uint8_t *ptr;
 257
 258         if ((!buffer) || (!offset)) {
 259                 printk(KERN_ERR "udf: udf_get_fileextent() invalidparms\n");
 260                 return NULL;
 261         }
 262
 263         fe = (struct fileEntry *)buffer;
 264
 265         if (fe->descTag.tagIdent != cpu_to_le16(TAG_IDENT_FE)) {
 266                 udf_debug("0x%x != TAG_IDENT_FE\n",
 267                           le16_to_cpu(fe->descTag.tagIdent));
 268                 return NULL;
 269         }
 270
 271         ptr = (uint8_t *)(fe->extendedAttr) +
 272                 le32_to_cpu(fe->lengthExtendedAttr);
 273
 274         if ((*offset > 0) && (*offset < le32_to_cpu(fe->lengthAllocDescs)))
 275                 ptr += *offset;
 276
 277         ext = (extent_ad *)ptr;
 278
 279         *offset = *offset + sizeof(extent_ad);
 280         return ext;
 281 }
 282 #endif
 283
 284 short_ad *udf_get_fileshortad(uint8_t *ptr, int maxoffset, int *offset,
 285                               int inc)
 286 {
 287         short_ad *sa;
 288
 289         if ((!ptr) || (!offset)) {
 290                 printk(KERN_ERR "udf: udf_get_fileshortad() invalidparms\n");
 291                 return NULL;
 292         }
 293
 294         if ((*offset < 0) || ((*offset + sizeof(short_ad)) > maxoffset))
 295                 return NULL;
 296         else {
 297                 sa = (short_ad *)ptr;
 298                 if (sa->extLength == 0)
 299                         return NULL;
 300         }
 301
 302         if (inc)
 303                 *offset += sizeof(short_ad);
 304         return sa;
 305 }
 306
 307 long_ad *udf_get_filelongad(uint8_t *ptr, int maxoffset, int *offset, int inc)
 308 {
 309         long_ad *la;
 310
 311         if ((!ptr) || (!offset)) {
 312                 printk(KERN_ERR "udf: udf_get_filelongad() invalidparms\n");
 313                 return NULL;
 314         }
 315
 316         if ((*offset < 0) || ((*offset + sizeof(long_ad)) > maxoffset))
 317                 return NULL;
 318         else {
 319                 la = (long_ad *)ptr;
 320                 if (la->extLength == 0)
 321                         return NULL;
 322         }
 323
 324         if (inc)
 325                 *offset += sizeof(long_ad);
 326         return la;
 327 }