fs/hfs/file.c

/*
 * libhfs - library for reading and writing Macintosh HFS volumes
 * Copyright (C) 1996-1998 Robert Leslie
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */

# ifdef HAVE_CONFIG_H
#  include "config.h"
# endif

# include <string.h>
# include <errno.h>

# include "libhfs.h"
# include "file.h"
# include "btree.h"
# include "record.h"
# include "volume.h"

/*
 * NAME:        file->init()
 * DESCRIPTION: initialize file structure
 */
void f_init(hfsfile *file, hfsvol *vol, long cnid, const char *name)
{
  int i;

  file->vol   = vol;
  file->parid = 0;

  strcpy(file->name, name);

  file->cat.cdrType          = cdrFilRec;
  file->cat.cdrResrv2        = 0;

  file->cat.u.fil.filFlags   = 0;
  file->cat.u.fil.filTyp     = 0;

  file->cat.u.fil.filUsrWds.fdType       = 0;
  file->cat.u.fil.filUsrWds.fdCreator    = 0;
  file->cat.u.fil.filUsrWds.fdFlags      = 0;
  file->cat.u.fil.filUsrWds.fdLocation.v = 0;
  file->cat.u.fil.filUsrWds.fdLocation.h = 0;
  file->cat.u.fil.filUsrWds.fdFldr       = 0;

  file->cat.u.fil.filFlNum   = cnid;
  file->cat.u.fil.filStBlk   = 0;
  file->cat.u.fil.filLgLen   = 0;
  file->cat.u.fil.filPyLen   = 0;
  file->cat.u.fil.filRStBlk  = 0;
  file->cat.u.fil.filRLgLen  = 0;
  file->cat.u.fil.filRPyLen  = 0;
  file->cat.u.fil.filCrDat   = 0;
  file->cat.u.fil.filMdDat   = 0;
  file->cat.u.fil.filBkDat   = 0;

  file->cat.u.fil.filFndrInfo.fdIconID = 0;
  for (i = 0; i < 4; ++i)
    file->cat.u.fil.filFndrInfo.fdUnused[i] = 0;
  file->cat.u.fil.filFndrInfo.fdComment = 0;
  file->cat.u.fil.filFndrInfo.fdPutAway = 0;

  file->cat.u.fil.filClpSize = 0;

  for (i = 0; i < 3; ++i)
    {
      file->cat.u.fil.filExtRec[i].xdrStABN     = 0;
      file->cat.u.fil.filExtRec[i].xdrNumABlks  = 0;

      file->cat.u.fil.filRExtRec[i].xdrStABN    = 0;
      file->cat.u.fil.filRExtRec[i].xdrNumABlks = 0;
    }

  file->cat.u.fil.filResrv   = 0;

  f_selectfork(file, fkData);

  file->flags = 0;

  file->prev  = 0;
  file->next  = 0;
}

/*
 * NAME:        file->selectfork()
 * DESCRIPTION: choose a fork for file operations
 */
void f_selectfork(hfsfile *file, int fork)
{
  file->fork = fork;

  memcpy(&file->ext, fork == fkData ?
         &file->cat.u.fil.filExtRec : &file->cat.u.fil.filRExtRec,
         sizeof(ExtDataRec));

  file->fabn = 0;
  file->pos  = 0;
}

/*
 * NAME:        file->getptrs()
 * DESCRIPTION: make pointers to the current fork's lengths and extents
 */
void f_getptrs(hfsfile *file, ExtDataRec **extrec,
               unsigned long **lglen, unsigned long **pylen)
{
  if (file->fork == fkData)
    {
      if (extrec)
        *extrec = &file->cat.u.fil.filExtRec;
      if (lglen)
        *lglen  = &file->cat.u.fil.filLgLen;
      if (pylen)
        *pylen  = &file->cat.u.fil.filPyLen;
    }
  else
    {
      if (extrec)
        *extrec = &file->cat.u.fil.filRExtRec;
      if (lglen)
        *lglen  = &file->cat.u.fil.filRLgLen;
      if (pylen)
        *pylen  = &file->cat.u.fil.filRPyLen;
    }
}

/*
 * NAME:        file->doblock()
 * DESCRIPTION: read or write a numbered block from a file
 */
int f_doblock(hfsfile *file, unsigned long num, block *bp,
              int (*func)(hfsvol *, unsigned int, unsigned int, block *))
{
  unsigned int abnum;
  unsigned int blnum;
  unsigned int fabn;
  int i;

  abnum = num / file->vol->lpa;
  blnum = num % file->vol->lpa;

  /* locate the appropriate extent record */

  fabn = file->fabn;

  if (abnum < fabn)
    {
      ExtDataRec *extrec;

      f_getptrs(file, &extrec, 0, 0);

      fabn = file->fabn = 0;
      memcpy(&file->ext, extrec, sizeof(ExtDataRec));
    }
  else
    abnum -= fabn;

  while (1)
    {
      unsigned int n;

      for (i = 0; i < 3; ++i)
        {
          n = file->ext[i].xdrNumABlks;

          if (abnum < n)
            return func(file->vol, file->ext[i].xdrStABN + abnum, blnum, bp);

          fabn  += n;
          abnum -= n;
        }

      if (v_extsearch(file, fabn, &file->ext, 0) <= 0)
        goto fail;

      file->fabn = fabn;
    }

fail:
  return -1;
}

/*
 * NAME:        file->addextent()
 * DESCRIPTION: add an extent to a file
 */
int f_addextent(hfsfile *file, ExtDescriptor *blocks)
{
  hfsvol *vol = file->vol;
  ExtDataRec *extrec;
  unsigned long *pylen;
  unsigned int start, end;
  node n;
  int i;

  f_getptrs(file, &extrec, 0, &pylen);

  start  = file->fabn;
  end    = *pylen / vol->mdb.drAlBlkSiz;

  n.nnum = 0;
  i      = -1;

  while (start < end)
    {
      for (i = 0; i < 3; ++i)
        {
          unsigned int num;

          num    = file->ext[i].xdrNumABlks;
          start += num;

          if (start == end)
            break;
          else if (start > end)
            ERROR(EIO, "file extents exceed file physical length");
          else if (num == 0)
            ERROR(EIO, "empty file extent");
        }

      if (start == end)
        break;

      if (v_extsearch(file, start, &file->ext, &n) <= 0)
        goto fail;

      file->fabn = start;
    }

  if (i >= 0 &&
      file->ext[i].xdrStABN + file->ext[i].xdrNumABlks == blocks->xdrStABN)
    file->ext[i].xdrNumABlks += blocks->xdrNumABlks;
  else
    {
      /* create a new extent descriptor */

      if (++i < 3)
        file->ext[i] = *blocks;
      else
        {
          ExtKeyRec key;
          byte record[HFS_MAX_EXTRECLEN];
          unsigned int reclen;

          /* record is full; create a new one */

          file->ext[0] = *blocks;

          for (i = 1; i < 3; ++i)
            {
              file->ext[i].xdrStABN    = 0;
              file->ext[i].xdrNumABlks = 0;
            }

          file->fabn = start;

          r_makeextkey(&key, file->fork, file->cat.u.fil.filFlNum, end);
          r_packextrec(&key, &file->ext, record, &reclen);

          if (bt_insert(&vol->ext, record, reclen) == -1)
            goto fail;

          i = -1;
        }
    }

  if (i >= 0)
    {
      /* store the modified extent record */

      if (file->fabn)
        {
          if ((n.nnum == 0 &&
               v_extsearch(file, file->fabn, 0, &n) <= 0) ||
              v_putextrec(&file->ext, &n) == -1)
            goto fail;
        }
      else
        memcpy(extrec, &file->ext, sizeof(ExtDataRec));
    }

  *pylen += blocks->xdrNumABlks * vol->mdb.drAlBlkSiz;

  file->flags |= HFS_FILE_UPDATE_CATREC;

  return 0;

fail:
  return -1;
}

/*
 * NAME:        file->alloc()
 * DESCRIPTION: reserve allocation blocks for a file
 */
long f_alloc(hfsfile *file)
{
  hfsvol *vol = file->vol;
  unsigned long clumpsz;
  ExtDescriptor blocks;

  clumpsz = file->cat.u.fil.filClpSize;
  if (clumpsz == 0)
    {
      if (file == &vol->ext.f)
        clumpsz = vol->mdb.drXTClpSiz;
      else if (file == &vol->cat.f)
        clumpsz = vol->mdb.drCTClpSiz;
      else
        clumpsz = vol->mdb.drClpSiz;
    }

  blocks.xdrNumABlks = clumpsz / vol->mdb.drAlBlkSiz;

  if (v_allocblocks(vol, &blocks) == -1)
    goto fail;

  if (f_addextent(file, &blocks) == -1)
    {
      v_freeblocks(vol, &blocks);
      goto fail;
    }

  return blocks.xdrNumABlks;

fail:
  return -1;
}

/*
 * NAME:        file->trunc()
 * DESCRIPTION: release allocation blocks unneeded by a file
 */
int f_trunc(hfsfile *file)
{
  hfsvol *vol = file->vol;
  ExtDataRec *extrec;
  unsigned long *lglen, *pylen, alblksz, newpylen;
  unsigned int dlen, start, end;
  node n;
  int i;

  if (vol->flags & HFS_VOL_READONLY)
    goto done;

  f_getptrs(file, &extrec, &lglen, &pylen);

  alblksz  = vol->mdb.drAlBlkSiz;
  newpylen = (*lglen / alblksz + (*lglen % alblksz != 0)) * alblksz;

  if (newpylen > *pylen)
    ERROR(EIO, "file size exceeds physical length");
  else if (newpylen == *pylen)
    goto done;

  dlen  = (*pylen - newpylen) / alblksz;

  start = file->fabn;
  end   = newpylen / alblksz;

  if (start >= end)
    {
      start = file->fabn = 0;
      memcpy(&file->ext, extrec, sizeof(ExtDataRec));
    }

  n.nnum = 0;
  i      = -1;

  while (start < end)
    {
      for (i = 0; i < 3; ++i)
        {
          unsigned int num;

          num    = file->ext[i].xdrNumABlks;
          start += num;

          if (start >= end)
            break;
          else if (num == 0)
            ERROR(EIO, "empty file extent");
        }

      if (start >= end)
        break;

      if (v_extsearch(file, start, &file->ext, &n) <= 0)
        goto fail;

      file->fabn = start;
    }

  if (start > end)
    {
      ExtDescriptor blocks;

      file->ext[i].xdrNumABlks -= start - end;
      dlen -= start - end;

      blocks.xdrStABN    = file->ext[i].xdrStABN + file->ext[i].xdrNumABlks;
      blocks.xdrNumABlks = start - end;

      if (v_freeblocks(vol, &blocks) == -1)
        goto fail;
    }

  *pylen = newpylen;

  file->flags |= HFS_FILE_UPDATE_CATREC;

  do
    {
      while (dlen && ++i < 3)
        {
          unsigned int num;

          num    = file->ext[i].xdrNumABlks;
          start += num;

          if (num == 0)
            ERROR(EIO, "empty file extent");
          else if (num > dlen)
            ERROR(EIO, "file extents exceed physical size");

          dlen -= num;

          if (v_freeblocks(vol, &file->ext[i]) == -1)
            goto fail;

          file->ext[i].xdrStABN    = 0;
          file->ext[i].xdrNumABlks = 0;
        }

      if (file->fabn)
        {
          if (n.nnum == 0 &&
              v_extsearch(file, file->fabn, 0, &n) <= 0)
            goto fail;

          if (file->ext[0].xdrNumABlks)
            {
              if (v_putextrec(&file->ext, &n) == -1)
                goto fail;
            }
          else
            {
              if (bt_delete(&vol->ext, HFS_NODEREC(n, n.rnum)) == -1)
                goto fail;

              n.nnum = 0;
            }
        }
      else
        memcpy(extrec, &file->ext, sizeof(ExtDataRec));

      if (dlen)
        {
          if (v_extsearch(file, start, &file->ext, &n) <= 0)
            goto fail;

          file->fabn = start;
          i = -1;
        }
    }
  while (dlen);

done:
  return 0;

fail:
  return -1;
}

/*
 * NAME:        file->flush()
 * DESCRIPTION: flush all pending changes to an open file
 */
int f_flush(hfsfile *file)
{
  hfsvol *vol = file->vol;

  if (vol->flags & HFS_VOL_READONLY)
    goto done;

  if (file->flags & HFS_FILE_UPDATE_CATREC)
    {
      node n;

      file->cat.u.fil.filStBlk  = file->cat.u.fil.filExtRec[0].xdrStABN;
      file->cat.u.fil.filRStBlk = file->cat.u.fil.filRExtRec[0].xdrStABN;

      if (v_catsearch(vol, file->parid, file->name, 0, 0, &n) <= 0 ||
          v_putcatrec(&file->cat, &n) == -1)
        goto fail;

      file->flags &= ~HFS_FILE_UPDATE_CATREC;
    }

done:
  return 0;

fail:
  return -1;
}
1	dpavlin	1	/*
2			* libhfs - library for reading and writing Macintosh HFS volumes
3			* Copyright (C) 1996-1998 Robert Leslie
4			*
5			* This program is free software; you can redistribute it and/or modify
6			* it under the terms of the GNU General Public License as published by
7			* the Free Software Foundation; either version 2 of the License, or
8			* (at your option) any later version.
9			*
10			* This program is distributed in the hope that it will be useful,
11			* but WITHOUT ANY WARRANTY; without even the implied warranty of
12			* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13			* GNU General Public License for more details.
14			*
15			* You should have received a copy of the GNU General Public License
16			* along with this program; if not, write to the Free Software
17			* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
18			*
19			*/
20
21			# ifdef HAVE_CONFIG_H
22			# include "config.h"
23			# endif
24
25			# include <string.h>
26			# include <errno.h>
27
28			# include "libhfs.h"
29			# include "file.h"
30			# include "btree.h"
31			# include "record.h"
32			# include "volume.h"
33
34			/*
35			* NAME: file->init()
36			* DESCRIPTION: initialize file structure
37			*/
38			void f_init(hfsfile file, hfsvol vol, long cnid, const char *name)
39			{
40			int i;
41
42			file->vol = vol;
43			file->parid = 0;
44
45			strcpy(file->name, name);
46
47			file->cat.cdrType = cdrFilRec;
48			file->cat.cdrResrv2 = 0;
49
50			file->cat.u.fil.filFlags = 0;
51			file->cat.u.fil.filTyp = 0;
52
53			file->cat.u.fil.filUsrWds.fdType = 0;
54			file->cat.u.fil.filUsrWds.fdCreator = 0;
55			file->cat.u.fil.filUsrWds.fdFlags = 0;
56			file->cat.u.fil.filUsrWds.fdLocation.v = 0;
57			file->cat.u.fil.filUsrWds.fdLocation.h = 0;
58			file->cat.u.fil.filUsrWds.fdFldr = 0;
59
60			file->cat.u.fil.filFlNum = cnid;
61			file->cat.u.fil.filStBlk = 0;
62			file->cat.u.fil.filLgLen = 0;
63			file->cat.u.fil.filPyLen = 0;
64			file->cat.u.fil.filRStBlk = 0;
65			file->cat.u.fil.filRLgLen = 0;
66			file->cat.u.fil.filRPyLen = 0;
67			file->cat.u.fil.filCrDat = 0;
68			file->cat.u.fil.filMdDat = 0;
69			file->cat.u.fil.filBkDat = 0;
70
71			file->cat.u.fil.filFndrInfo.fdIconID = 0;
72			for (i = 0; i < 4; ++i)
73			file->cat.u.fil.filFndrInfo.fdUnused[i] = 0;
74			file->cat.u.fil.filFndrInfo.fdComment = 0;
75			file->cat.u.fil.filFndrInfo.fdPutAway = 0;
76
77			file->cat.u.fil.filClpSize = 0;
78
79			for (i = 0; i < 3; ++i)
80			{
81			file->cat.u.fil.filExtRec[i].xdrStABN = 0;
82			file->cat.u.fil.filExtRec[i].xdrNumABlks = 0;
83
84			file->cat.u.fil.filRExtRec[i].xdrStABN = 0;
85			file->cat.u.fil.filRExtRec[i].xdrNumABlks = 0;
86			}
87
88			file->cat.u.fil.filResrv = 0;
89
90			f_selectfork(file, fkData);
91
92			file->flags = 0;
93
94			file->prev = 0;
95			file->next = 0;
96			}
97
98			/*
99			* NAME: file->selectfork()
100			* DESCRIPTION: choose a fork for file operations
101			*/
102			void f_selectfork(hfsfile *file, int fork)
103			{
104			file->fork = fork;
105
106			memcpy(&file->ext, fork == fkData ?
107			&file->cat.u.fil.filExtRec : &file->cat.u.fil.filRExtRec,
108			sizeof(ExtDataRec));
109
110			file->fabn = 0;
111			file->pos = 0;
112			}
113
114			/*
115			* NAME: file->getptrs()
116			* DESCRIPTION: make pointers to the current fork's lengths and extents
117			*/
118			void f_getptrs(hfsfile file, ExtDataRec *extrec,
119			unsigned long lglen, unsigned long pylen)
120			{
121			if (file->fork == fkData)
122			{
123			if (extrec)
124			*extrec = &file->cat.u.fil.filExtRec;
125			if (lglen)
126			*lglen = &file->cat.u.fil.filLgLen;
127			if (pylen)
128			*pylen = &file->cat.u.fil.filPyLen;
129			}
130			else
131			{
132			if (extrec)
133			*extrec = &file->cat.u.fil.filRExtRec;
134			if (lglen)
135			*lglen = &file->cat.u.fil.filRLgLen;
136			if (pylen)
137			*pylen = &file->cat.u.fil.filRPyLen;
138			}
139			}
140
141			/*
142			* NAME: file->doblock()
143			* DESCRIPTION: read or write a numbered block from a file
144			*/
145			int f_doblock(hfsfile file, unsigned long num, block bp,
146			int (func)(hfsvol , unsigned int, unsigned int, block *))
147			{
148			unsigned int abnum;
149			unsigned int blnum;
150			unsigned int fabn;
151			int i;
152
153			abnum = num / file->vol->lpa;
154			blnum = num % file->vol->lpa;
155
156			/* locate the appropriate extent record */
157
158			fabn = file->fabn;
159
160			if (abnum < fabn)
161			{
162			ExtDataRec *extrec;
163
164			f_getptrs(file, &extrec, 0, 0);
165
166			fabn = file->fabn = 0;
167			memcpy(&file->ext, extrec, sizeof(ExtDataRec));
168			}
169			else
170			abnum -= fabn;
171
172			while (1)
173			{
174			unsigned int n;
175
176			for (i = 0; i < 3; ++i)
177			{
178			n = file->ext[i].xdrNumABlks;
179
180			if (abnum < n)
181			return func(file->vol, file->ext[i].xdrStABN + abnum, blnum, bp);
182
183			fabn += n;
184			abnum -= n;
185			}
186
187			if (v_extsearch(file, fabn, &file->ext, 0) <= 0)
188			goto fail;
189
190			file->fabn = fabn;
191			}
192
193			fail:
194			return -1;
195			}
196
197			/*
198			* NAME: file->addextent()
199			* DESCRIPTION: add an extent to a file
200			*/
201			int f_addextent(hfsfile file, ExtDescriptor blocks)
202			{
203			hfsvol *vol = file->vol;
204			ExtDataRec *extrec;
205			unsigned long *pylen;
206			unsigned int start, end;
207			node n;
208			int i;
209
210			f_getptrs(file, &extrec, 0, &pylen);
211
212			start = file->fabn;
213			end = *pylen / vol->mdb.drAlBlkSiz;
214
215			n.nnum = 0;
216			i = -1;
217
218			while (start < end)
219			{
220			for (i = 0; i < 3; ++i)
221			{
222			unsigned int num;
223
224			num = file->ext[i].xdrNumABlks;
225			start += num;
226
227			if (start == end)
228			break;
229			else if (start > end)
230			ERROR(EIO, "file extents exceed file physical length");
231			else if (num == 0)
232			ERROR(EIO, "empty file extent");
233			}
234
235			if (start == end)
236			break;
237
238			if (v_extsearch(file, start, &file->ext, &n) <= 0)
239			goto fail;
240
241			file->fabn = start;
242			}
243
244			if (i >= 0 &&
245			file->ext[i].xdrStABN + file->ext[i].xdrNumABlks == blocks->xdrStABN)
246			file->ext[i].xdrNumABlks += blocks->xdrNumABlks;
247			else
248			{
249			/* create a new extent descriptor */
250
251			if (++i < 3)
252			file->ext[i] = *blocks;
253			else
254			{
255			ExtKeyRec key;
256			byte record[HFS_MAX_EXTRECLEN];
257			unsigned int reclen;
258
259			/* record is full; create a new one */
260
261			file->ext[0] = *blocks;
262
263			for (i = 1; i < 3; ++i)
264			{
265			file->ext[i].xdrStABN = 0;
266			file->ext[i].xdrNumABlks = 0;
267			}
268
269			file->fabn = start;
270
271			r_makeextkey(&key, file->fork, file->cat.u.fil.filFlNum, end);
272			r_packextrec(&key, &file->ext, record, &reclen);
273
274			if (bt_insert(&vol->ext, record, reclen) == -1)
275			goto fail;
276
277			i = -1;
278			}
279			}
280
281			if (i >= 0)
282			{
283			/* store the modified extent record */
284
285			if (file->fabn)
286			{
287			if ((n.nnum == 0 &&
288			v_extsearch(file, file->fabn, 0, &n) <= 0) \|\|
289			v_putextrec(&file->ext, &n) == -1)
290			goto fail;
291			}
292			else
293			memcpy(extrec, &file->ext, sizeof(ExtDataRec));
294			}
295
296			pylen += blocks->xdrNumABlks vol->mdb.drAlBlkSiz;
297
298			file->flags \|= HFS_FILE_UPDATE_CATREC;
299
300			return 0;
301
302			fail:
303			return -1;
304			}
305
306			/*
307			* NAME: file->alloc()
308			* DESCRIPTION: reserve allocation blocks for a file
309			*/
310			long f_alloc(hfsfile *file)
311			{
312			hfsvol *vol = file->vol;
313			unsigned long clumpsz;
314			ExtDescriptor blocks;
315
316			clumpsz = file->cat.u.fil.filClpSize;
317			if (clumpsz == 0)
318			{
319			if (file == &vol->ext.f)
320			clumpsz = vol->mdb.drXTClpSiz;
321			else if (file == &vol->cat.f)
322			clumpsz = vol->mdb.drCTClpSiz;
323			else
324			clumpsz = vol->mdb.drClpSiz;
325			}
326
327			blocks.xdrNumABlks = clumpsz / vol->mdb.drAlBlkSiz;
328
329			if (v_allocblocks(vol, &blocks) == -1)
330			goto fail;
331
332			if (f_addextent(file, &blocks) == -1)
333			{
334			v_freeblocks(vol, &blocks);
335			goto fail;
336			}
337
338			return blocks.xdrNumABlks;
339
340			fail:
341			return -1;
342			}
343
344			/*
345			* NAME: file->trunc()
346			* DESCRIPTION: release allocation blocks unneeded by a file
347			*/
348			int f_trunc(hfsfile *file)
349			{
350			hfsvol *vol = file->vol;
351			ExtDataRec *extrec;
352			unsigned long lglen, pylen, alblksz, newpylen;
353			unsigned int dlen, start, end;
354			node n;
355			int i;
356
357			if (vol->flags & HFS_VOL_READONLY)
358			goto done;
359
360			f_getptrs(file, &extrec, &lglen, &pylen);
361
362			alblksz = vol->mdb.drAlBlkSiz;
363			newpylen = (lglen / alblksz + (lglen % alblksz != 0)) * alblksz;
364
365			if (newpylen > *pylen)
366			ERROR(EIO, "file size exceeds physical length");
367			else if (newpylen == *pylen)
368			goto done;
369
370			dlen = (*pylen - newpylen) / alblksz;
371
372			start = file->fabn;
373			end = newpylen / alblksz;
374
375			if (start >= end)
376			{
377			start = file->fabn = 0;
378			memcpy(&file->ext, extrec, sizeof(ExtDataRec));
379			}
380
381			n.nnum = 0;
382			i = -1;
383
384			while (start < end)
385			{
386			for (i = 0; i < 3; ++i)
387			{
388			unsigned int num;
389
390			num = file->ext[i].xdrNumABlks;
391			start += num;
392
393			if (start >= end)
394			break;
395			else if (num == 0)
396			ERROR(EIO, "empty file extent");
397			}
398
399			if (start >= end)
400			break;
401
402			if (v_extsearch(file, start, &file->ext, &n) <= 0)
403			goto fail;
404
405			file->fabn = start;
406			}
407
408			if (start > end)
409			{
410			ExtDescriptor blocks;
411
412			file->ext[i].xdrNumABlks -= start - end;
413			dlen -= start - end;
414
415			blocks.xdrStABN = file->ext[i].xdrStABN + file->ext[i].xdrNumABlks;
416			blocks.xdrNumABlks = start - end;
417
418			if (v_freeblocks(vol, &blocks) == -1)
419			goto fail;
420			}
421
422			*pylen = newpylen;
423
424			file->flags \|= HFS_FILE_UPDATE_CATREC;
425
426			do
427			{
428			while (dlen && ++i < 3)
429			{
430			unsigned int num;
431
432			num = file->ext[i].xdrNumABlks;
433			start += num;
434
435			if (num == 0)
436			ERROR(EIO, "empty file extent");
437			else if (num > dlen)
438			ERROR(EIO, "file extents exceed physical size");
439
440			dlen -= num;
441
442			if (v_freeblocks(vol, &file->ext[i]) == -1)
443			goto fail;
444
445			file->ext[i].xdrStABN = 0;
446			file->ext[i].xdrNumABlks = 0;
447			}
448
449			if (file->fabn)
450			{
451			if (n.nnum == 0 &&
452			v_extsearch(file, file->fabn, 0, &n) <= 0)
453			goto fail;
454
455			if (file->ext[0].xdrNumABlks)
456			{
457			if (v_putextrec(&file->ext, &n) == -1)
458			goto fail;
459			}
460			else
461			{
462			if (bt_delete(&vol->ext, HFS_NODEREC(n, n.rnum)) == -1)
463			goto fail;
464
465			n.nnum = 0;
466			}
467			}
468			else
469			memcpy(extrec, &file->ext, sizeof(ExtDataRec));
470
471			if (dlen)
472			{
473			if (v_extsearch(file, start, &file->ext, &n) <= 0)
474			goto fail;
475
476			file->fabn = start;
477			i = -1;
478			}
479			}
480			while (dlen);
481
482			done:
483			return 0;
484
485			fail:
486			return -1;
487			}
488
489			/*
490			* NAME: file->flush()
491			* DESCRIPTION: flush all pending changes to an open file
492			*/
493			int f_flush(hfsfile *file)
494			{
495			hfsvol *vol = file->vol;
496
497			if (vol->flags & HFS_VOL_READONLY)
498			goto done;
499
500			if (file->flags & HFS_FILE_UPDATE_CATREC)
501			{
502			node n;
503
504			file->cat.u.fil.filStBlk = file->cat.u.fil.filExtRec[0].xdrStABN;
505			file->cat.u.fil.filRStBlk = file->cat.u.fil.filRExtRec[0].xdrStABN;
506
507			if (v_catsearch(vol, file->parid, file->name, 0, 0, &n) <= 0 \|\|
508			v_putcatrec(&file->cat, &n) == -1)
509			goto fail;
510
511			file->flags &= ~HFS_FILE_UPDATE_CATREC;
512			}
513
514			done:
515			return 0;
516
517			fail:
518			return -1;
519			}