i386/linux/linux-2.3.21/fs/ntfs/attr.c

   1 /*
   2  *  attr.c
   3  *
   4  *  Copyright (C) 1996-1999 Martin von Löwis
   5  *  Copyright (C) 1996-1997 Régis Duchesne
   6  *  Copyright (C) 1998 Joseph Malicki
   7  *  Copyright (C) 1999 Steve Dodd
   8  */
   9
  10 #include "ntfstypes.h"
  11 #include "struct.h"
  12 #include "attr.h"
  13
  14 #include <linux/errno.h>
  15 #ifdef HAVE_STRING_H
  16 #include <string.h>
  17 #endif
  18 #include "macros.h"
  19 #include "support.h"
  20 #include "util.h"
  21 #include "super.h"
  22 #include "inode.h"
  23
  24 /* Look if an attribute already exists in the inode, and if not, create it */
  25 int
  26 ntfs_new_attr(ntfs_inode *ino,int type,void *name,int namelen,int *pos,
  27                         int *found, int do_search )
  28 {
  29         int do_insert=0;
  30         int i;
  31
  32         for(i=0;i<ino->attr_count;i++)
  33         {
  34                 int n=min(namelen,ino->attrs[i].namelen);
  35                 int s=ntfs_uni_strncmp(ino->attrs[i].name,name,n);
  36                 if( do_search ) {
  37                         /*
  38                          * We assume that each attribute can be uniquely
  39                          * identified by inode
  40                          * number, attribute type and attribute name.
  41                          */
  42                         if(ino->attrs[i].type==type && ino->attrs[i].namelen==namelen && !s){
  43                                 *found=1;
  44                                 *pos=i;
  45                                 return 0;
  46                         }
  47                 }
  48                 /* attributes are ordered by type, then by name */
  49                 if(ino->attrs[i].type>type || (ino->attrs[i].type==type && s==1)){
  50                         do_insert=1;
  51                         break;
  52                 }
  53         }
  54
  55         /* re-allocate space */
  56         if(ino->attr_count % 8 ==0)
  57         {
  58                 ntfs_attribute* new;
  59                 new = (ntfs_attribute*)ntfs_malloc((ino->attr_count+8)*
  60                              sizeof(ntfs_attribute));
  61                 if( !new )
  62                         return ENOMEM;
  63                 if( ino->attrs ) {
  64                         ntfs_memcpy( new, ino->attrs, ino->attr_count*sizeof(ntfs_attribute) );
  65                         ntfs_free( ino->attrs );
  66                 }
  67                 ino->attrs = new;
  68         }
  69         if(do_insert)
  70                 ntfs_memmove(ino->attrs+i+1,ino->attrs+i,(ino->attr_count-i)*
  71                             sizeof(ntfs_attribute));
  72
  73         ino->attr_count++;
  74         ino->attrs[i].type=type;
  75         ino->attrs[i].namelen=namelen;
  76         ino->attrs[i].name=name;
  77         *pos=i;
  78         *found=0;
  79         return 0;
  80 }
  81
  82 int
  83 ntfs_make_attr_resident(ntfs_inode *ino,ntfs_attribute *attr)
  84 {
  85         int size=attr->size;
  86         if(size>0){
  87                 /* FIXME: read data, free clusters */
  88                 return EOPNOTSUPP;
  89         }
  90         attr->resident=1;
  91         return 0;
  92 }
  93
  94 /* Store in the inode readable information about a run */
  95 void
  96 ntfs_insert_run(ntfs_attribute *attr,int cnum,ntfs_cluster_t cluster,int len)
  97 {
  98         /* (re-)allocate space if necessary */
  99         if(attr->d.r.len % 8 == 0) {
 100                 ntfs_runlist* new;
 101                 new = ntfs_malloc((attr->d.r.len+8)*sizeof(ntfs_runlist));
 102                 if( !new )
 103                         return;
 104                 if( attr->d.r.runlist ) {
 105                         ntfs_memcpy(new, attr->d.r.runlist, attr->d.r.len
 106                                     *sizeof(ntfs_runlist));
 107                         ntfs_free( attr->d.r.runlist );
 108                 }
 109                 attr->d.r.runlist = new;
 110         }
 111         if(attr->d.r.len>cnum)
 112                 ntfs_memmove(attr->d.r.runlist+cnum+1,attr->d.r.runlist+cnum,
 113                             (attr->d.r.len-cnum)*sizeof(ntfs_runlist));
 114         attr->d.r.runlist[cnum].cluster=cluster;
 115         attr->d.r.runlist[cnum].len=len;
 116         attr->d.r.len++;
 117 }
 118
 119 /* Extends an attribute. Another run will be added if necessary,
 120  * but we try to extend the last run in the runlist first.
 121  * FIXME: what if there isn't enough contiguous space, we don't create
 122  * multiple runs?
 123  *
 124  * *len: the desired new length of the attr (_not_ the amount to extend by)
 125  */
 126 int ntfs_extend_attr(ntfs_inode *ino, ntfs_attribute *attr, int *len,
 127                 int flags)
 128 {
 129         int error=0;
 130         ntfs_runlist *rl;
 131         int rlen;
 132         ntfs_cluster_t cluster;
 133         int clen;
 134
 135         if(attr->compressed)return EOPNOTSUPP;
 136         if(ino->record_count>1)return EOPNOTSUPP;
 137
 138         if(attr->resident) {
 139                 error = ntfs_make_attr_nonresident(ino,attr);
 140                 if(error)
 141                         return error;
 142         }
 143
 144         if( *len <= attr->allocated )
 145                 return 0;       /* truely stupid things do sometimes happen */
 146
 147         rl=attr->d.r.runlist;
 148         rlen=attr->d.r.len-1;
 149
 150         if(rlen>=0)
 151                 cluster=rl[rlen].cluster+rl[rlen].len;
 152         else
 153                 /* no preference for allocation space */
 154                 cluster=0;
 155
 156         /* calculate the extra space we need, and round up to multiple of cluster
 157          * size to get number of new clusters needed */
 158
 159         clen=( (*len - attr->allocated ) + ino->vol->clustersize - 1 ) /
 160                 ino->vol->clustersize;
 161         if(clen==0)
 162                 return 0;
 163
 164         /* FIXME: try to allocate smaller pieces */
 165         error=ntfs_allocate_clusters(ino->vol,&cluster,&clen,
 166                                      flags|ALLOC_REQUIRE_SIZE);
 167         if(error)return error;
 168         attr->allocated += clen*ino->vol->clustersize;
 169         *len = attr->allocated;
 170
 171         /* contiguous chunk */
 172         if(rlen>=0 && cluster==rl[rlen].cluster+rl[rlen].len){
 173                 rl[rlen].len += clen;
 174                 return 0;
 175         }
 176         ntfs_insert_run(attr,rlen+1,cluster,clen);
 177         return 0;
 178 }
 179
 180 int
 181 ntfs_make_attr_nonresident(ntfs_inode *ino, ntfs_attribute *attr)
 182 {
 183         void *data=attr->d.data;
 184         int len=attr->size;
 185         int error,alen;
 186         ntfs_io io;
 187         attr->d.r.len=0;
 188         attr->d.r.runlist=0;
 189         attr->resident=0;
 190         attr->allocated=attr->initialized=0;
 191         alen=len;
 192         error=ntfs_extend_attr(ino,attr,&alen,ALLOC_REQUIRE_SIZE);
 193         if(error)return error;/* FIXME: On error, restore old values */
 194         io.fn_put=ntfs_put;
 195         io.fn_get=ntfs_get;
 196         io.param=data;
 197         io.size=len;
 198         io.do_read=0;
 199         return ntfs_readwrite_attr(ino,attr,0,&io);
 200 }
 201
 202 int
 203 ntfs_attr_allnonresident(ntfs_inode *ino)
 204 {
 205         int i, error=0;
 206         ntfs_volume *vol = ino->vol;
 207
 208         for (i=0; !error && i<ino->attr_count; i++)
 209         {
 210                 if (ino->attrs[i].type != vol->at_security_descriptor
 211                     && ino->attrs[i].type != vol->at_data)
 212                         continue;
 213                 error = ntfs_make_attr_nonresident (ino, ino->attrs+i);
 214         }
 215         return error;
 216 }
 217
 218 /* Resize the attribute to a newsize */
 219 int ntfs_resize_attr(ntfs_inode *ino, ntfs_attribute *attr, int newsize)
 220 {
 221         int error=0;
 222         int oldsize=attr->size;
 223         int clustersize=ino->vol->clustersize;
 224         int i,count,newlen,newcount;
 225         ntfs_runlist *rl;
 226
 227         if(newsize==oldsize)
 228                 return 0;
 229         /* modifying compressed attributes not supported yet */
 230         if(attr->compressed)
 231                 /* extending is easy: just insert sparse runs */
 232                 return EOPNOTSUPP;
 233         if(attr->resident){
 234                 void *v;
 235                 if(newsize>ino->vol->mft_recordsize){
 236                         error=ntfs_make_attr_nonresident(ino,attr);
 237                         if(error)return error;
 238                         return ntfs_resize_attr(ino,attr,newsize);
 239                 }
 240                 v=attr->d.data;
 241                 if(newsize){
 242                         attr->d.data=ntfs_malloc(newsize);
 243                         if(!attr->d.data) {
 244                                 ntfs_free(v);
 245                                 return ENOMEM;
 246                         }
 247                         if(newsize>oldsize)
 248                                 ntfs_bzero((char*)attr->d.data+oldsize,
 249                                            newsize-oldsize);
 250                         ntfs_memcpy((char*)attr->d.data,v,min(newsize,oldsize));
 251                 }else
 252                         attr->d.data=0;
 253                 ntfs_free(v);
 254                 attr->size=newsize;
 255                 return 0;
 256         }
 257         /* non-resident attribute */
 258         rl=attr->d.r.runlist;
 259         if(newsize<oldsize){
 260                 for(i=0,count=0;i<attr->d.r.len;i++){
 261                         if((count+rl[i].len)*clustersize>newsize)
 262                                 break;
 263                         count+=(int)rl[i].len;
 264                 }
 265                 newlen=i+1;
 266                 /* free unused clusters in current run, unless sparse */
 267                 newcount=count;
 268                 if(rl[i].cluster!=MAX_CLUSTER_T){
 269                         int rounded=newsize-count*clustersize;
 270                         rounded=(rounded+clustersize-1)/clustersize;
 271                         error=ntfs_deallocate_clusters(ino->vol,rl[i].cluster+rounded,
 272                                                        (int)rl[i].len-rounded);
 273                         if(error)
 274                                 return error; /* FIXME: incomplete operation */
 275                         rl[i].len=rounded;
 276                         newcount=count+rounded;
 277                 }
 278                 /* free all other runs */
 279                 for(i++;i<attr->d.r.len;i++)
 280                         if(rl[i].cluster!=MAX_CLUSTER_T){
 281                                 error=ntfs_deallocate_clusters(ino->vol,rl[i].cluster,(int)rl[i].len);
 282                                 if(error)
 283                                         return error; /* FIXME: incomplete operation */
 284                         }
 285                 /* FIXME? free space for extra runs in memory */
 286                 attr->d.r.len=newlen;
 287         }else{
 288                 newlen=newsize;
 289                 error=ntfs_extend_attr(ino,attr,&newlen,ALLOC_REQUIRE_SIZE);
 290                 if(error)return error; /* FIXME: incomplete */
 291                 newcount=newlen/clustersize;
 292         }
 293         /* fill in new sizes */
 294         attr->allocated = newcount*clustersize;
 295         attr->size = newsize;
 296         /* attr->initialized does not change. */
 297         if(!newsize)
 298                 error=ntfs_make_attr_resident(ino,attr);
 299         return error;
 300 }
 301
 302 int ntfs_create_attr(ntfs_inode *ino, int anum, char *aname, void *data,
 303         int dsize, ntfs_attribute **rattr)
 304 {
 305         void *name;
 306         int namelen;
 307         int found,i;
 308         int error;
 309         ntfs_attribute *attr;
 310         if(dsize>ino->vol->mft_recordsize)
 311                 /* FIXME: non-resident attributes */
 312                 return EOPNOTSUPP;
 313         if(aname){
 314                 namelen=strlen(aname);
 315                 name=ntfs_malloc(2*namelen);
 316                 if( !name )
 317                         return ENOMEM;
 318                 ntfs_ascii2uni(name,aname,namelen);
 319         }else{
 320                 name=0;
 321                 namelen=0;
 322         }
 323
 324         error = ntfs_new_attr(ino,anum,name,namelen,&i,&found,1);
 325         if( error ) {
 326                 ntfs_free( name );
 327                 return error;
 328         }
 329
 330         if(found){
 331                 ntfs_free(name);
 332                 return EEXIST;
 333         }
 334         *rattr=attr=ino->attrs+i;
 335         /* allocate a new number.
 336            FIXME: Should this happen on inode writeback?
 337            FIXME: extensions records not supported */
 338         error=ntfs_allocate_attr_number(ino,&i);
 339         if(error)
 340                 return error;
 341         attr->attrno=i;
 342
 343         attr->resident=1;
 344         attr->compressed=attr->cengine=0;
 345         attr->size=attr->allocated=attr->initialized=dsize;
 346
 347         /* FIXME: INDEXED information should come from $AttrDef
 348            Currently, only file names are indexed */
 349         if(anum==ino->vol->at_file_name){
 350                 attr->indexed=1;
 351         }else
 352                 attr->indexed=0;
 353         attr->d.data=ntfs_malloc(dsize);
 354
 355         if( !attr->d.data )
 356                 return ENOMEM;
 357
 358         ntfs_memcpy(attr->d.data,data,dsize);
 359         return 0;
 360 }
 361
 362 /* Non-resident attributes are stored in runs (intervals of clusters).
 363  *
 364  * This function stores in the inode readable information about a non-resident
 365  * attribute.
 366  */
 367 static int
 368 ntfs_process_runs(ntfs_inode *ino,ntfs_attribute* attr,unsigned char *data)
 369 {
 370         int startvcn,endvcn;
 371         int vcn,cnum;
 372         ntfs_cluster_t cluster;
 373         int len,ctype;
 374         startvcn = NTFS_GETU64(data+0x10);
 375         endvcn = NTFS_GETU64(data+0x18);
 376
 377         /* check whether this chunk really belongs to the end */
 378         for(cnum=0,vcn=0;cnum<attr->d.r.len;cnum++)
 379                 vcn+=attr->d.r.runlist[cnum].len;
 380         if(vcn!=startvcn)
 381         {
 382                 ntfs_error("Problem with runlist in extended record\n");
 383                 return -1;
 384         }
 385         if(!endvcn)
 386         {
 387                 endvcn = NTFS_GETU64(data+0x28)-1; /* allocated length */
 388                 endvcn /= ino->vol->clustersize;
 389         }
 390         data=data+NTFS_GETU16(data+0x20);
 391         cnum=attr->d.r.len;
 392         cluster=0;
 393         for(vcn=startvcn; vcn<=endvcn; vcn+=len)
 394         {
 395                 if(ntfs_decompress_run(&data,&len,&cluster,&ctype))
 396                         return -1;
 397                 if(ctype)
 398                         ntfs_insert_run(attr,cnum,-1,len);
 399                 else
 400                         ntfs_insert_run(attr,cnum,cluster,len);
 401                 cnum++;
 402         }
 403         return 0;
 404 }
 405
 406 /* Insert the attribute starting at attr in the inode ino */
 407 int ntfs_insert_attribute(ntfs_inode *ino, unsigned char* attrdata)
 408 {
 409         int i,found;
 410         int type;
 411         short int *name;
 412         int namelen;
 413         void *data;
 414         ntfs_attribute *attr;
 415         int error;
 416
 417         type = NTFS_GETU32(attrdata);
 418         namelen = NTFS_GETU8(attrdata+9);
 419         /* read the attribute's name if it has one */
 420         if(!namelen)
 421                 name=0;
 422         else
 423         {
 424                 /* 1 Unicode character fits in 2 bytes */
 425                 name=ntfs_malloc(2*namelen);
 426                 if( !name )
 427                         return ENOMEM;
 428
 429                 ntfs_memcpy(name,attrdata+NTFS_GETU16(attrdata+10),2*namelen);
 430         }
 431
 432         error = ntfs_new_attr(ino,type,name,namelen,&i,&found,1);
 433         if( error ) {
 434                 if( name ) ntfs_free( name );
 435                 return error;
 436         }
 437
 438         /* We can have in one inode two attributes with type 0x00000030 (File Name)
 439            and without name */
 440         if(found && /*FIXME*/type!=ino->vol->at_file_name)
 441         {
 442                 ntfs_process_runs(ino,ino->attrs+i,attrdata);
 443                 return 0;
 444         } else if( found ) {
 445                 /*      Don't understand the above, but I know it leaks memory below
 446                         as it overwrites a found entry without freeing it. So here we
 447                         call ntfs_new_attr again but this time ask it to always allocate a
 448                         new     entry */
 449                 ntfs_new_attr(ino,type,name,namelen,&i,&found,0);
 450         }
 451         attr=ino->attrs+i;
 452         attr->resident=NTFS_GETU8(attrdata+8)==0;
 453         attr->compressed=NTFS_GETU16(attrdata+0xC);
 454         attr->attrno=NTFS_GETU16(attrdata+0xE);
 455
 456         if(attr->resident) {
 457                 attr->size=NTFS_GETU16(attrdata+0x10);
 458                 data=attrdata+NTFS_GETU16(attrdata+0x14);
 459                 attr->d.data = (void*)ntfs_malloc(attr->size);
 460                 if( !attr->d.data )
 461                         return ENOMEM;
 462                 ntfs_memcpy(attr->d.data,data,attr->size);
 463                 attr->indexed=NTFS_GETU16(attrdata+0x16);
 464         }else{
 465                 attr->allocated=NTFS_GETU32(attrdata+0x28);
 466                 attr->size=NTFS_GETU32(attrdata+0x30);
 467                 attr->initialized=NTFS_GETU32(attrdata+0x38);
 468                 attr->cengine=NTFS_GETU16(attrdata+0x22);
 469                 if(attr->compressed)
 470                         attr->compsize=NTFS_GETU32(attrdata+0x40);
 471                 ino->attrs[i].d.r.runlist=0;
 472                 ino->attrs[i].d.r.len=0;
 473                 ntfs_process_runs(ino,attr,attrdata);
 474         }
 475         return 0;
 476 }
 477
 478 int
 479 ntfs_read_zero(ntfs_io *dest,int size)
 480 {
 481         char *sparse=ntfs_calloc(512);
 482         if(!sparse)
 483                 return ENOMEM;
 484         while(size){
 485                 int i=min(size,512);
 486                 dest->fn_put(dest,sparse,i);
 487                 size-=i;
 488         }
 489         ntfs_free(sparse);
 490         return 0;
 491 }
 492
 493 /* process compressed attributes */
 494 int ntfs_read_compressed(ntfs_inode *ino, ntfs_attribute *attr, int offset,
 495         ntfs_io *dest)
 496 {
 497         int error=0;
 498         int clustersize,l;
 499         int s_vcn,rnum,vcn,len,chunk,got,l1,offs1,copied;
 500         ntfs_cluster_t cluster,cl1;
 501         char *comp=0,*comp1;
 502         char *decomp=0;
 503         ntfs_io io;
 504         ntfs_runlist *rl;
 505
 506         l=dest->size;
 507         clustersize=ino->vol->clustersize;
 508         /* starting cluster of potential chunk
 509            there are three situations:
 510            a) in a large uncompressible or sparse chunk,
 511            s_vcn is in the middle of a run
 512            b) s_vcn is right on a run border
 513            c) when several runs make a chunk, s_vcn is before the chunks
 514         */
 515         s_vcn=offset/clustersize;
 516         /* round down to multiple of 16 */
 517         s_vcn &= ~15;
 518         rl=attr->d.r.runlist;
 519         for(rnum=vcn=0;rnum<attr->d.r.len && vcn+rl->len<=s_vcn;rnum++,rl++)
 520                 vcn+=rl->len;
 521         if(rnum==attr->d.r.len){
 522                 /* beyond end of file */
 523                 /* FIXME: check allocated/initialized */
 524                 dest->size=0;
 525                 return 0;
 526         }
 527         io.do_read=1;
 528         io.fn_put=ntfs_put;
 529         io.fn_get=0;
 530         cluster=rl->cluster;
 531         len=rl->len;
 532         copied=0;
 533         while(l){
 534                 chunk=0;
 535                 if(cluster==MAX_CLUSTER_T){
 536                         /* sparse cluster */
 537                         int l1;
 538                         if((len-(s_vcn-vcn)) & 15)
 539                                 ntfs_error("unexpected sparse chunk size");
 540                         l1=chunk = min((vcn+len)*clustersize-offset,l);
 541                         error = ntfs_read_zero(dest,l1);
 542                         if(error)
 543                                 goto out;
 544                 }else if(dest->do_read){
 545                         if(!comp){
 546                                 comp=ntfs_malloc(16*clustersize);
 547                                 if(!comp){
 548                                         error=ENOMEM;
 549                                         goto out;
 550                                 }
 551                         }
 552                         got=0;
 553                         /* we might need to start in the middle of a run */
 554                         cl1=cluster+s_vcn-vcn;
 555                         comp1=comp;
 556                         do{
 557                                 io.param=comp1;
 558                                 l1=min(len-max(s_vcn-vcn,0),16-got);
 559                                 io.size=l1*clustersize;
 560                                 error=ntfs_getput_clusters(ino->vol,cl1,0,&io);
 561                                 if(error)goto out;
 562                                 if(l1+max(s_vcn-vcn,0)==len){
 563                                         rnum++;rl++;
 564                                         vcn+=len;
 565                                         cluster=cl1=rl->cluster;
 566                                         len=rl->len;
 567                                 }
 568                                 got+=l1;
 569                                 comp1+=l1*clustersize;
 570                         }while(cluster!=MAX_CLUSTER_T && got<16); /* until empty run */
 571                         chunk=16*clustersize;
 572                         if(cluster!=MAX_CLUSTER_T || got==16)
 573                                 /* uncompressible */
 574                                 comp1=comp;
 575                         else{
 576                                 if(!decomp){
 577                                         decomp=ntfs_malloc(16*clustersize);
 578                                         if(!decomp){
 579                                                 error=ENOMEM;
 580                                                 goto out;
 581                                         }
 582                                 }
 583                                 /* make sure there are null bytes
 584                                    after the last block */
 585                                 *(ntfs_u32*)comp1=0;
 586                                 ntfs_decompress(decomp,comp,chunk);
 587                                 comp1=decomp;
 588                         }
 589                         offs1=offset-s_vcn*clustersize;
 590                         chunk=min(16*clustersize-offs1,chunk);
 591                         chunk=min(l,chunk);
 592                         dest->fn_put(dest,comp1+offs1,chunk);
 593                 }
 594                 l-=chunk;
 595                 copied+=chunk;
 596                 offset+=chunk;
 597                 s_vcn=offset/clustersize & ~15;
 598                 if(l && offset>=((vcn+len)*clustersize)){
 599                         rnum++;rl++;
 600                         vcn+=len;
 601                         cluster=rl->cluster;
 602                         len=rl->len;
 603                 }
 604         }
 605  out:
 606         if(comp)ntfs_free(comp);
 607         if(decomp)ntfs_free(decomp);
 608         dest->size=copied;
 609         return error;
 610 }
 611
 612 int ntfs_write_compressed(ntfs_inode *ino, ntfs_attribute *attr, int offset,
 613         ntfs_io *dest)
 614 {
 615         return EOPNOTSUPP;
 616 }
 617
 618 /*
 619  * Local variables:
 620  * c-file-style: "linux"
 621  * End:
 622  */