1 /* fsys_xfs.c - an implementation for the SGI XFS file system */
2 /*
3 * GRUB -- GRand Unified Bootloader
4 * Copyright (C) 2001,2002,2004 Free Software Foundation, Inc.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19 */
20
21 #ifdef FSYS_XFS
22
23 #include "shared.h"
24 #include "filesys.h"
25 #include "xfs.h"
26
27 #define MAX_LINK_COUNT 8
28
29 typedef struct xad {
30 xfs_fileoff_t offset;
31 xfs_fsblock_t start;
32 xfs_filblks_t len;
33 } xad_t;
34
35 struct xfs_info {
36 int bsize;
37 int dirbsize;
38 int isize;
39 unsigned int agblocks;
40 int bdlog;
41 int blklog;
42 int inopblog;
43 int agblklog;
44 int agnolog;
45 unsigned int nextents;
46 xfs_daddr_t next;
47 xfs_daddr_t daddr;
48 xfs_dablk_t forw;
49 xfs_dablk_t dablk;
50 xfs_bmbt_rec_32_t *xt;
51 xfs_bmbt_ptr_t ptr0;
52 int btnode_ptr0_off;
53 int i8param;
54 int dirpos;
55 int dirmax;
56 int blkoff;
57 int fpos;
58 xfs_ino_t rootino;
59 };
60
61 static struct xfs_info xfs;
62
63 #define dirbuf ((char *)FSYS_BUF)
64 #define filebuf ((char *)FSYS_BUF + 4096)
65 #define inode ((xfs_dinode_t *)((char *)FSYS_BUF + 8192))
66 #define icore (inode->di_core)
67
68 #define mask32lo(n) (((xfs_uint32_t)1 << (n)) - 1)
69
70 #define XFS_INO_MASK(k) ((xfs_uint32_t)((1ULL << (k)) - 1))
71 #define XFS_INO_OFFSET_BITS xfs.inopblog
72 #define XFS_INO_AGBNO_BITS xfs.agblklog
73 #define XFS_INO_AGINO_BITS (xfs.agblklog + xfs.inopblog)
74 #define XFS_INO_AGNO_BITS xfs.agnolog
75
76 static inline xfs_agblock_t
agino2agbno(xfs_agino_t agino)77 agino2agbno (xfs_agino_t agino)
78 {
79 return agino >> XFS_INO_OFFSET_BITS;
80 }
81
82 static inline xfs_agnumber_t
ino2agno(xfs_ino_t ino)83 ino2agno (xfs_ino_t ino)
84 {
85 return ino >> XFS_INO_AGINO_BITS;
86 }
87
88 static inline xfs_agino_t
ino2agino(xfs_ino_t ino)89 ino2agino (xfs_ino_t ino)
90 {
91 return ino & XFS_INO_MASK(XFS_INO_AGINO_BITS);
92 }
93
94 static inline int
ino2offset(xfs_ino_t ino)95 ino2offset (xfs_ino_t ino)
96 {
97 return ino & XFS_INO_MASK(XFS_INO_OFFSET_BITS);
98 }
99
100 static inline __const__ xfs_uint16_t
le16(xfs_uint16_t x)101 le16 (xfs_uint16_t x)
102 {
103 __asm__("xchgb %b0,%h0" \
104 : "=q" (x) \
105 : "0" (x)); \
106 return x;
107 }
108
109 static inline __const__ xfs_uint32_t
le32(xfs_uint32_t x)110 le32 (xfs_uint32_t x)
111 {
112 #if 0
113 /* 386 doesn't have bswap. */
114 __asm__("bswap %0" : "=r" (x) : "0" (x));
115 #else
116 /* This is slower but this works on all x86 architectures. */
117 __asm__("xchgb %b0, %h0" \
118 "\n\troll $16, %0" \
119 "\n\txchgb %b0, %h0" \
120 : "=q" (x) : "0" (x));
121 #endif
122 return x;
123 }
124
125 static inline __const__ xfs_uint64_t
le64(xfs_uint64_t x)126 le64 (xfs_uint64_t x)
127 {
128 xfs_uint32_t h = x >> 32;
129 xfs_uint32_t l = x & ((1ULL<<32)-1);
130 return (((xfs_uint64_t)le32(l)) << 32) | ((xfs_uint64_t)(le32(h)));
131 }
132
133
134 static xfs_fsblock_t
xt_start(xfs_bmbt_rec_32_t * r)135 xt_start (xfs_bmbt_rec_32_t *r)
136 {
137 return (((xfs_fsblock_t)(le32 (r->l1) & mask32lo(9))) << 43) |
138 (((xfs_fsblock_t)le32 (r->l2)) << 11) |
139 (((xfs_fsblock_t)le32 (r->l3)) >> 21);
140 }
141
142 static xfs_fileoff_t
xt_offset(xfs_bmbt_rec_32_t * r)143 xt_offset (xfs_bmbt_rec_32_t *r)
144 {
145 return (((xfs_fileoff_t)le32 (r->l0) &
146 mask32lo(31)) << 23) |
147 (((xfs_fileoff_t)le32 (r->l1)) >> 9);
148 }
149
150 static xfs_filblks_t
xt_len(xfs_bmbt_rec_32_t * r)151 xt_len (xfs_bmbt_rec_32_t *r)
152 {
153 return le32(r->l3) & mask32lo(21);
154 }
155
156 static inline int
xfs_highbit32(xfs_uint32_t v)157 xfs_highbit32(xfs_uint32_t v)
158 {
159 int i;
160
161 if (--v) {
162 for (i = 0; i < 31; i++, v >>= 1) {
163 if (v == 0)
164 return i;
165 }
166 }
167 return 0;
168 }
169
170 static int
isinxt(xfs_fileoff_t key,xfs_fileoff_t offset,xfs_filblks_t len)171 isinxt (xfs_fileoff_t key, xfs_fileoff_t offset, xfs_filblks_t len)
172 {
173 return (key >= offset) ? (key < offset + len ? 1 : 0) : 0;
174 }
175
176 static xfs_daddr_t
agb2daddr(xfs_agnumber_t agno,xfs_agblock_t agbno)177 agb2daddr (xfs_agnumber_t agno, xfs_agblock_t agbno)
178 {
179 return ((xfs_fsblock_t)agno*xfs.agblocks + agbno) << xfs.bdlog;
180 }
181
182 static xfs_daddr_t
fsb2daddr(xfs_fsblock_t fsbno)183 fsb2daddr (xfs_fsblock_t fsbno)
184 {
185 return agb2daddr ((xfs_agnumber_t)(fsbno >> xfs.agblklog),
186 (xfs_agblock_t)(fsbno & mask32lo(xfs.agblklog)));
187 }
188
189 #undef offsetof
190 #define offsetof(t,m) ((int)&(((t *)0)->m))
191
192 static inline int
btroot_maxrecs(void)193 btroot_maxrecs (void)
194 {
195 int tmp = icore.di_forkoff ? (icore.di_forkoff << 3) : xfs.isize;
196
197 return (tmp - sizeof(xfs_bmdr_block_t) - offsetof(xfs_dinode_t, di_u)) /
198 (sizeof (xfs_bmbt_key_t) + sizeof (xfs_bmbt_ptr_t));
199 }
200
201 static int
di_read(xfs_ino_t ino)202 di_read (xfs_ino_t ino)
203 {
204 xfs_agino_t agino;
205 xfs_agnumber_t agno;
206 xfs_agblock_t agbno;
207 xfs_daddr_t daddr;
208 int offset;
209
210 agno = ino2agno (ino);
211 agino = ino2agino (ino);
212 agbno = agino2agbno (agino);
213 offset = ino2offset (ino);
214 daddr = agb2daddr (agno, agbno);
215
216 devread (daddr, offset*xfs.isize, xfs.isize, (char *)inode);
217
218 xfs.ptr0 = *(xfs_bmbt_ptr_t *)
219 (inode->di_u.di_c + sizeof(xfs_bmdr_block_t)
220 + btroot_maxrecs ()*sizeof(xfs_bmbt_key_t));
221
222 return 1;
223 }
224
225 static void
init_extents(void)226 init_extents (void)
227 {
228 xfs_bmbt_ptr_t ptr0;
229 xfs_btree_lblock_t h;
230
231 switch (icore.di_format) {
232 case XFS_DINODE_FMT_EXTENTS:
233 xfs.xt = inode->di_u.di_bmx;
234 xfs.nextents = le32 (icore.di_nextents);
235 break;
236 case XFS_DINODE_FMT_BTREE:
237 ptr0 = xfs.ptr0;
238 for (;;) {
239 xfs.daddr = fsb2daddr (le64(ptr0));
240 devread (xfs.daddr, 0,
241 sizeof(xfs_btree_lblock_t), (char *)&h);
242 if (!h.bb_level) {
243 xfs.nextents = le16(h.bb_numrecs);
244 xfs.next = fsb2daddr (le64(h.bb_rightsib));
245 xfs.fpos = sizeof(xfs_btree_block_t);
246 return;
247 }
248 devread (xfs.daddr, xfs.btnode_ptr0_off,
249 sizeof(xfs_bmbt_ptr_t), (char *)&ptr0);
250 }
251 }
252 }
253
254 static xad_t *
next_extent(void)255 next_extent (void)
256 {
257 static xad_t xad;
258
259 switch (icore.di_format) {
260 case XFS_DINODE_FMT_EXTENTS:
261 if (xfs.nextents == 0)
262 return NULL;
263 break;
264 case XFS_DINODE_FMT_BTREE:
265 if (xfs.nextents == 0) {
266 xfs_btree_lblock_t h;
267 if (xfs.next == 0)
268 return NULL;
269 xfs.daddr = xfs.next;
270 devread (xfs.daddr, 0, sizeof(xfs_btree_lblock_t), (char *)&h);
271 xfs.nextents = le16(h.bb_numrecs);
272 xfs.next = fsb2daddr (le64(h.bb_rightsib));
273 xfs.fpos = sizeof(xfs_btree_block_t);
274 }
275 /* Yeah, I know that's slow, but I really don't care */
276 devread (xfs.daddr, xfs.fpos, sizeof(xfs_bmbt_rec_t), filebuf);
277 xfs.xt = (xfs_bmbt_rec_32_t *)filebuf;
278 xfs.fpos += sizeof(xfs_bmbt_rec_32_t);
279 }
280 xad.offset = xt_offset (xfs.xt);
281 xad.start = xt_start (xfs.xt);
282 xad.len = xt_len (xfs.xt);
283 ++xfs.xt;
284 --xfs.nextents;
285
286 return &xad;
287 }
288
289 /*
290 * Name lies - the function reads only first 100 bytes
291 */
292 static void
xfs_dabread(void)293 xfs_dabread (void)
294 {
295 xad_t *xad;
296 xfs_fileoff_t offset;;
297
298 init_extents ();
299 while ((xad = next_extent ())) {
300 offset = xad->offset;
301 if (isinxt (xfs.dablk, offset, xad->len)) {
302 devread (fsb2daddr (xad->start + xfs.dablk - offset),
303 0, 100, dirbuf);
304 break;
305 }
306 }
307 }
308
309 static inline xfs_ino_t
sf_ino(char * sfe,int namelen)310 sf_ino (char *sfe, int namelen)
311 {
312 void *p = sfe + namelen + 3;
313
314 return (xfs.i8param == 0)
315 ? le64(*(xfs_ino_t *)p) : le32(*(xfs_uint32_t *)p);
316 }
317
318 static inline xfs_ino_t
sf_parent_ino(void)319 sf_parent_ino (void)
320 {
321 return (xfs.i8param == 0)
322 ? le64(*(xfs_ino_t *)(&inode->di_u.di_dir2sf.hdr.parent))
323 : le32(*(xfs_uint32_t *)(&inode->di_u.di_dir2sf.hdr.parent));
324 }
325
326 static inline int
roundup8(int n)327 roundup8 (int n)
328 {
329 return ((n+7)&~7);
330 }
331
332 static char *
next_dentry(xfs_ino_t * ino)333 next_dentry (xfs_ino_t *ino)
334 {
335 int namelen = 1;
336 int toread;
337 static char *usual[2][3] = {".", ".."};
338 static xfs_dir2_sf_entry_t *sfe;
339 char *name = usual[0][0];
340
341 if (xfs.dirpos >= xfs.dirmax) {
342 if (xfs.forw == 0)
343 return NULL;
344 xfs.dablk = xfs.forw;
345 xfs_dabread ();
346 #define h ((xfs_dir2_leaf_hdr_t *)dirbuf)
347 xfs.dirmax = le16 (h->count) - le16 (h->stale);
348 xfs.forw = le32 (h->info.forw);
349 #undef h
350 xfs.dirpos = 0;
351 }
352
353 switch (icore.di_format) {
354 case XFS_DINODE_FMT_LOCAL:
355 switch (xfs.dirpos) {
356 case -2:
357 *ino = 0;
358 break;
359 case -1:
360 *ino = sf_parent_ino ();
361 ++name;
362 ++namelen;
363 sfe = (xfs_dir2_sf_entry_t *)
364 (inode->di_u.di_c
365 + sizeof(xfs_dir2_sf_hdr_t)
366 - xfs.i8param);
367 break;
368 default:
369 namelen = sfe->namelen;
370 *ino = sf_ino ((char *)sfe, namelen);
371 name = sfe->name;
372 sfe = (xfs_dir2_sf_entry_t *)
373 ((char *)sfe + namelen + 11 - xfs.i8param);
374 }
375 break;
376 case XFS_DINODE_FMT_BTREE:
377 case XFS_DINODE_FMT_EXTENTS:
378 #define dau ((xfs_dir2_data_union_t *)dirbuf)
379 for (;;) {
380 if (xfs.blkoff >= xfs.dirbsize) {
381 xfs.blkoff = sizeof(xfs_dir2_data_hdr_t);
382 filepos &= ~(xfs.dirbsize - 1);
383 filepos |= xfs.blkoff;
384 }
385 xfs_read (dirbuf, 4);
386 xfs.blkoff += 4;
387 if (dau->unused.freetag == XFS_DIR2_DATA_FREE_TAG) {
388 toread = roundup8 (le16(dau->unused.length)) - 4;
389 xfs.blkoff += toread;
390 filepos += toread;
391 continue;
392 }
393 break;
394 }
395 xfs_read ((char *)dirbuf + 4, 5);
396 *ino = le64 (dau->entry.inumber);
397 namelen = dau->entry.namelen;
398 #undef dau
399 toread = roundup8 (namelen + 11) - 9;
400 xfs_read (dirbuf, toread);
401 name = (char *)dirbuf;
402 xfs.blkoff += toread + 5;
403 }
404 ++xfs.dirpos;
405 name[namelen] = 0;
406
407 return name;
408 }
409
410 static char *
first_dentry(xfs_ino_t * ino)411 first_dentry (xfs_ino_t *ino)
412 {
413 xfs.forw = 0;
414 switch (icore.di_format) {
415 case XFS_DINODE_FMT_LOCAL:
416 xfs.dirmax = inode->di_u.di_dir2sf.hdr.count;
417 xfs.i8param = inode->di_u.di_dir2sf.hdr.i8count ? 0 : 4;
418 xfs.dirpos = -2;
419 break;
420 case XFS_DINODE_FMT_EXTENTS:
421 case XFS_DINODE_FMT_BTREE:
422 filepos = 0;
423 xfs_read (dirbuf, sizeof(xfs_dir2_data_hdr_t));
424 if (((xfs_dir2_data_hdr_t *)dirbuf)->magic == le32(XFS_DIR2_BLOCK_MAGIC)) {
425 #define tail ((xfs_dir2_block_tail_t *)dirbuf)
426 filepos = xfs.dirbsize - sizeof(*tail);
427 xfs_read (dirbuf, sizeof(*tail));
428 xfs.dirmax = le32 (tail->count) - le32 (tail->stale);
429 #undef tail
430 } else {
431 xfs.dablk = (1ULL << 35) >> xfs.blklog;
432 #define h ((xfs_dir2_leaf_hdr_t *)dirbuf)
433 #define n ((xfs_da_intnode_t *)dirbuf)
434 for (;;) {
435 xfs_dabread ();
436 if ((n->hdr.info.magic == le16(XFS_DIR2_LEAFN_MAGIC))
437 || (n->hdr.info.magic == le16(XFS_DIR2_LEAF1_MAGIC))) {
438 xfs.dirmax = le16 (h->count) - le16 (h->stale);
439 xfs.forw = le32 (h->info.forw);
440 break;
441 }
442 xfs.dablk = le32 (n->btree[0].before);
443 }
444 #undef n
445 #undef h
446 }
447 xfs.blkoff = sizeof(xfs_dir2_data_hdr_t);
448 filepos = xfs.blkoff;
449 xfs.dirpos = 0;
450 }
451 return next_dentry (ino);
452 }
453
454 int
xfs_mount(void)455 xfs_mount (void)
456 {
457 xfs_sb_t super;
458
459 if (!devread (0, 0, sizeof(super), (char *)&super)
460 || (le32(super.sb_magicnum) != XFS_SB_MAGIC)
461 || ((le16(super.sb_versionnum)
462 & XFS_SB_VERSION_NUMBITS) != XFS_SB_VERSION_4) ) {
463 return 0;
464 }
465
466 xfs.bsize = le32 (super.sb_blocksize);
467 xfs.blklog = super.sb_blocklog;
468 xfs.bdlog = xfs.blklog - SECTOR_BITS;
469 xfs.rootino = le64 (super.sb_rootino);
470 xfs.isize = le16 (super.sb_inodesize);
471 xfs.agblocks = le32 (super.sb_agblocks);
472 xfs.dirbsize = xfs.bsize << super.sb_dirblklog;
473
474 xfs.inopblog = super.sb_inopblog;
475 xfs.agblklog = super.sb_agblklog;
476 xfs.agnolog = xfs_highbit32 (le32(super.sb_agcount));
477
478 xfs.btnode_ptr0_off =
479 ((xfs.bsize - sizeof(xfs_btree_block_t)) /
480 (sizeof (xfs_bmbt_key_t) + sizeof (xfs_bmbt_ptr_t)))
481 * sizeof(xfs_bmbt_key_t) + sizeof(xfs_btree_block_t);
482
483 return 1;
484 }
485
486 int
xfs_read(char * buf,int len)487 xfs_read (char *buf, int len)
488 {
489 xad_t *xad;
490 xfs_fileoff_t endofprev, endofcur, offset;
491 xfs_filblks_t xadlen;
492 int toread, startpos, endpos;
493
494 if (icore.di_format == XFS_DINODE_FMT_LOCAL) {
495 grub_memmove (buf, inode->di_u.di_c + filepos, len);
496 filepos += len;
497 return len;
498 }
499
500 startpos = filepos;
501 endpos = filepos + len;
502 endofprev = (xfs_fileoff_t)-1;
503 init_extents ();
504 while (len > 0 && (xad = next_extent ())) {
505 offset = xad->offset;
506 xadlen = xad->len;
507 if (isinxt (filepos >> xfs.blklog, offset, xadlen)) {
508 endofcur = (offset + xadlen) << xfs.blklog;
509 toread = (endofcur >= endpos)
510 ? len : (endofcur - filepos);
511
512 disk_read_func = disk_read_hook;
513 devread (fsb2daddr (xad->start),
514 filepos - (offset << xfs.blklog), toread, buf);
515 disk_read_func = NULL;
516
517 buf += toread;
518 len -= toread;
519 filepos += toread;
520 } else if (offset > endofprev) {
521 toread = ((offset << xfs.blklog) >= endpos)
522 ? len : ((offset - endofprev) << xfs.blklog);
523 len -= toread;
524 filepos += toread;
525 for (; toread; toread--) {
526 *buf++ = 0;
527 }
528 continue;
529 }
530 endofprev = offset + xadlen;
531 }
532
533 return filepos - startpos;
534 }
535
536 int
xfs_dir(char * dirname)537 xfs_dir (char *dirname)
538 {
539 xfs_ino_t ino, parent_ino, new_ino;
540 xfs_fsize_t di_size;
541 int di_mode;
542 int cmp, n, link_count;
543 char linkbuf[xfs.bsize];
544 char *rest, *name, ch;
545
546 parent_ino = ino = xfs.rootino;
547 link_count = 0;
548 for (;;) {
549 di_read (ino);
550 di_size = le64 (icore.di_size);
551 di_mode = le16 (icore.di_mode);
552
553 if ((di_mode & IFMT) == IFLNK) {
554 if (++link_count > MAX_LINK_COUNT) {
555 errnum = ERR_SYMLINK_LOOP;
556 return 0;
557 }
558 if (di_size < xfs.bsize - 1) {
559 filepos = 0;
560 filemax = di_size;
561 n = xfs_read (linkbuf, filemax);
562 } else {
563 errnum = ERR_FILELENGTH;
564 return 0;
565 }
566
567 ino = (linkbuf[0] == '/') ? xfs.rootino : parent_ino;
568 while (n < (xfs.bsize - 1) && (linkbuf[n++] = *dirname++));
569 linkbuf[n] = 0;
570 dirname = linkbuf;
571 continue;
572 }
573
574 if (!*dirname || isspace (*dirname)) {
575 if ((di_mode & IFMT) != IFREG) {
576 errnum = ERR_BAD_FILETYPE;
577 return 0;
578 }
579 filepos = 0;
580 filemax = di_size;
581 return 1;
582 }
583
584 if ((di_mode & IFMT) != IFDIR) {
585 errnum = ERR_BAD_FILETYPE;
586 return 0;
587 }
588
589 for (; *dirname == '/'; dirname++);
590
591 for (rest = dirname; (ch = *rest) && !isspace (ch) && ch != '/'; rest++);
592 *rest = 0;
593
594 name = first_dentry (&new_ino);
595 for (;;) {
596 cmp = (!*dirname) ? -1 : substring (dirname, name);
597 #ifndef STAGE1_5
598 if (print_possibilities && ch != '/' && cmp <= 0) {
599 if (print_possibilities > 0)
600 print_possibilities = -print_possibilities;
601 print_a_completion (name);
602 } else
603 #endif
604 if (cmp == 0) {
605 parent_ino = ino;
606 if (new_ino)
607 ino = new_ino;
608 *(dirname = rest) = ch;
609 break;
610 }
611 name = next_dentry (&new_ino);
612 if (name == NULL) {
613 if (print_possibilities < 0)
614 return 1;
615
616 errnum = ERR_FILE_NOT_FOUND;
617 *rest = ch;
618 return 0;
619 }
620 }
621 }
622 }
623
624 #endif /* FSYS_XFS */
625