xref: /dflybsd-src/sbin/hammer2/ondisk.c (revision c825a6c5bc23e72617bbb2bede9bfb99724bada0)
1 /*
2  * Copyright (c) 2020 Tomohiro Kusumi <tkusumi@netbsd.org>
3  * Copyright (c) 2020 The DragonFly Project
4  * All rights reserved.
5  *
6  * This code is derived from software contributed to The DragonFly Project
7  * by Matthew Dillon <dillon@dragonflybsd.org>
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  *
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in
17  *    the documentation and/or other materials provided with the
18  *    distribution.
19  * 3. Neither the name of The DragonFly Project nor the names of its
20  *    contributors may be used to endorse or promote products derived
21  *    from this software without specific, prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
24  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
25  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
26  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
27  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
28  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
29  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
30  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
31  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
32  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
33  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  */
36 
37 #include <sys/types.h>
38 #include <sys/stat.h>
39 #include <unistd.h>
40 #include <fcntl.h>
41 #include <stdio.h>
42 #include <stdlib.h>
43 #include <stdint.h>
44 #include <string.h>
45 #include <fstab.h>
46 #include <assert.h>
47 #include <errno.h>
48 #include <err.h>
49 
50 #include <vfs/hammer2/hammer2_disk.h>
51 
52 #include "hammer2_subs.h"
53 
54 static hammer2_ondisk_t fso;
55 static int hammer2_volumes_initialized;
56 
57 static void
hammer2_init_volume(hammer2_volume_t * vol)58 hammer2_init_volume(hammer2_volume_t *vol)
59 {
60 	vol->fd = -1;
61 	vol->id = -1;
62 	vol->offset = (hammer2_off_t)-1;
63 	vol->size = (hammer2_off_t)-1;
64 }
65 
66 void
hammer2_init_ondisk(hammer2_ondisk_t * fsp)67 hammer2_init_ondisk(hammer2_ondisk_t *fsp)
68 {
69 	int i;
70 
71 	bzero(fsp, sizeof(*fsp));
72 	fsp->version = -1;
73 	for (i = 0; i < HAMMER2_MAX_VOLUMES; ++i)
74 		hammer2_init_volume(&fsp->volumes[i]);
75 }
76 
77 void
hammer2_install_volume(hammer2_volume_t * vol,int fd,int id,const char * path,hammer2_off_t offset,hammer2_off_t size)78 hammer2_install_volume(hammer2_volume_t *vol, int fd, int id, const char *path,
79 		       hammer2_off_t offset, hammer2_off_t size)
80 {
81 	bzero(vol, sizeof(*vol));
82 	vol->fd = fd;
83 	vol->id = id;
84 	vol->path = strdup(path);
85 	vol->offset = offset;
86 	vol->size = size;
87 }
88 
89 void
hammer2_uninstall_volume(hammer2_volume_t * vol)90 hammer2_uninstall_volume(hammer2_volume_t *vol)
91 {
92 	fsync(vol->fd);
93 	close(vol->fd);
94 	free(vol->path);
95 	hammer2_init_volume(vol);
96 }
97 
98 /*
99  * Locate a valid volume header.  If any of the four volume headers is good,
100  * we have a valid volume header and choose the best one based on mirror_tid.
101  */
102 static int
hammer2_read_volume_header(int fd,const char * path,hammer2_volume_data_t * voldata)103 hammer2_read_volume_header(int fd, const char *path,
104 			   hammer2_volume_data_t *voldata)
105 {
106 	hammer2_volume_data_t vd;
107 	hammer2_tid_t mirror_tid = -1;
108 	hammer2_off_t size = check_volume(fd);
109 	hammer2_crc32_t crc0, crc1;
110 	const char *p;
111 	int i, zone = -1;
112 	ssize_t ret;
113 
114 	for (i = 0; i < HAMMER2_NUM_VOLHDRS; ++i) {
115 		if (i * HAMMER2_ZONE_BYTES64 >= size)
116 			break;
117 		if (lseek(fd, i * HAMMER2_ZONE_BYTES64, SEEK_SET) == -1)
118 			break;
119 		ret = read(fd, &vd, HAMMER2_VOLUME_BYTES);
120 		if (ret == -1) {
121 			fprintf(stderr, "%s #%d: read %s\n",
122 				path, i, strerror(errno));
123 			continue;
124 		}
125 		if (ret != HAMMER2_VOLUME_BYTES) {
126 			fprintf(stderr, "%s #%d: read %s\n",
127 				path, i, strerror(errno));
128 			continue;
129 		}
130 
131 		p = (const char*)&vd;
132 		/* verify volume header magic */
133 		if ((vd.magic != HAMMER2_VOLUME_ID_HBO) &&
134 		    (vd.magic != HAMMER2_VOLUME_ID_ABO)) {
135 			fprintf(stderr, "%s #%d: bad magic\n", path, i);
136 			continue;
137 		}
138 
139 		if (vd.magic == HAMMER2_VOLUME_ID_ABO) {
140 			/* XXX: Reversed-endianness filesystem */
141 			fprintf(stderr,
142 				"%s #%d: reverse-endian filesystem detected",
143 				path, i);
144 			continue;
145 		}
146 
147 		/* verify volume header CRC's */
148 		crc0 = vd.icrc_sects[HAMMER2_VOL_ICRC_SECT0];
149 		crc1 = hammer2_icrc32(p + HAMMER2_VOLUME_ICRC0_OFF,
150 				      HAMMER2_VOLUME_ICRC0_SIZE);
151 		if (crc0 != crc1) {
152 			fprintf(stderr,
153 				"%s #%d: volume header crc mismatch "
154 				"sect0 %08x/%08x\n",
155 				path, i, crc0, crc1);
156 			continue;
157 		}
158 
159 		crc0 = vd.icrc_sects[HAMMER2_VOL_ICRC_SECT1];
160 		crc1 = hammer2_icrc32(p + HAMMER2_VOLUME_ICRC1_OFF,
161 				      HAMMER2_VOLUME_ICRC1_SIZE);
162 		if (crc0 != crc1) {
163 			fprintf(stderr,
164 				"%s #%d: volume header crc mismatch "
165 				"sect1 %08x/%08x",
166 				path, i, crc0, crc1);
167 			continue;
168 		}
169 
170 		crc0 = vd.icrc_volheader;
171 		crc1 = hammer2_icrc32(p + HAMMER2_VOLUME_ICRCVH_OFF,
172 				      HAMMER2_VOLUME_ICRCVH_SIZE);
173 		if (crc0 != crc1) {
174 			fprintf(stderr,
175 				"%s #%d: volume header crc mismatch "
176 				"vh %08x/%08x",
177 				path, i, crc0, crc1);
178 			continue;
179 		}
180 		if (zone == -1 || mirror_tid < vd.mirror_tid) {
181 			bcopy(&vd, voldata, sizeof(vd));
182 			mirror_tid = vd.mirror_tid;
183 			zone = i;
184 		}
185 	}
186 	return(zone);
187 }
188 
189 static void
hammer2_err_uuid_mismatch(uuid_t * uuid1,uuid_t * uuid2,const char * id)190 hammer2_err_uuid_mismatch(uuid_t *uuid1, uuid_t *uuid2, const char *id)
191 {
192 	char *p1 = NULL, *p2 = NULL;
193 
194 	hammer2_uuid_to_str(uuid1, &p1);
195 	hammer2_uuid_to_str(uuid2, &p2);
196 
197 	errx(1, "Volume %s uuid mismatch %s vs %s", id, p1, p2);
198 
199 	free(p1);
200 	free(p2);
201 }
202 
203 static void
hammer2_add_volume(const char * path,int rdonly)204 hammer2_add_volume(const char *path, int rdonly)
205 {
206 	hammer2_volume_data_t voldata;
207 	hammer2_volume_t *vol;
208 	struct stat st;
209 	int fd, i;
210 	uuid_t uuid;
211 
212 	fd = open(path, rdonly ? O_RDONLY : O_RDWR);
213 	if (fd == -1)
214 		err(1, "open");
215 
216 	if (fstat(fd, &st) == -1)
217 		err(1, "fstat");
218 	if (!S_ISCHR(st.st_mode) && !S_ISREG(st.st_mode))
219 		errx(1, "Unsupported file type");
220 
221 	if (hammer2_read_volume_header(fd, path, &voldata) >= 0) {
222 		i = voldata.volu_id;
223 		if (i < 0 || i >= HAMMER2_MAX_VOLUMES)
224 			errx(1, "%s has bad volume id %d", path, i);
225 		vol = &fso.volumes[i];
226 		if (vol->id != -1)
227 			errx(1, "volume id %d already initialized", i);
228 		/* all headers must have the same version, nvolumes and uuid */
229 		if (!fso.nvolumes) {
230 			fso.version = voldata.version;
231 			fso.nvolumes = voldata.nvolumes;
232 			fso.fsid = voldata.fsid;
233 			fso.fstype = voldata.fstype;
234 		} else {
235 			if (fso.version != (int)voldata.version)
236 				errx(1, "Volume version mismatch %d vs %d",
237 				     fso.version, (int)voldata.version);
238 			if (fso.nvolumes != voldata.nvolumes)
239 				errx(1, "Volume count mismatch %d vs %d",
240 				     fso.nvolumes, voldata.nvolumes);
241 			uuid = voldata.fsid;
242 			if (!uuid_equal(&fso.fsid, &uuid, NULL))
243 				hammer2_err_uuid_mismatch(&fso.fsid,
244 							  &uuid,
245 							  "fsid");
246 			uuid = voldata.fstype;
247 			if (!uuid_equal(&fso.fstype, &uuid, NULL))
248 				hammer2_err_uuid_mismatch(&fso.fstype,
249 							  &uuid,
250 							  "fstype");
251 		}
252 		/* all per-volume tests passed */
253 		hammer2_install_volume(vol, fd, i, path,
254 				       voldata.volu_loff[i], voldata.volu_size);
255 		fso.total_size += vol->size;
256 	} else {
257 		errx(1, "No valid volume headers found!");
258 	}
259 }
260 
261 static void
hammer2_verify_volumes_common(const hammer2_ondisk_t * fsp,const hammer2_volume_data_t * rootvoldata)262 hammer2_verify_volumes_common(const hammer2_ondisk_t *fsp,
263 			      const hammer2_volume_data_t *rootvoldata)
264 {
265 	const hammer2_volume_t *vol;
266 	hammer2_off_t size;
267 	struct stat *st;
268 	const char *path;
269 	char *str;
270 	int i, j, nvolumes = 0;
271 	uuid_t uuid;
272 
273 	if (fsp->version == -1)
274 		errx(1, "Bad volume version %d", fsp->version);
275 
276 	/* check initialized volume count */
277 	for (i = 0; i < HAMMER2_MAX_VOLUMES; ++i) {
278 		vol = &fsp->volumes[i];
279 		if (vol->id != -1)
280 			nvolumes++;
281 	}
282 
283 	/* check volume header */
284 	if (rootvoldata) {
285 		if (rootvoldata->volu_id != HAMMER2_ROOT_VOLUME)
286 			errx(1, "Volume id %d must be %d",
287 			     rootvoldata->volu_id, HAMMER2_ROOT_VOLUME);
288 		str = NULL;
289 		uuid = rootvoldata->fstype;
290 		hammer2_uuid_to_str(&uuid, &str);
291 		if (strcmp(str, HAMMER2_UUID_STRING))
292 			errx(1, "Volume fstype uuid %s must be %s", str,
293 			     HAMMER2_UUID_STRING);
294 	}
295 
296 	/* fsp->nvolumes hasn't been verified yet, use nvolumes */
297 	st = calloc(nvolumes, sizeof(*st));
298 
299 	for (i = 0; i < HAMMER2_MAX_VOLUMES; ++i) {
300 		vol = &fsp->volumes[i];
301 		if (vol->id == -1)
302 			continue;
303 		path = vol->path;
304 		/* check volumes are unique */
305 		if (stat(path, &st[i]) != 0)
306 			errx(1, "Failed to stat %s", path);
307 		if (fstat(vol->fd, &st[i]) != 0)
308 			errx(1, "Failed to fstat %d", vol->fd);
309 		for (j = 0; j < i; ++j) {
310 			if ((st[i].st_ino == st[j].st_ino) &&
311 			    (st[i].st_dev == st[j].st_dev))
312 				errx(1, "%s specified more than once", path);
313 		}
314 		/* check volume fields are initialized */
315 		if (vol->fd == -1)
316 			errx(1, "%s has bad fd %d", path, vol->fd);
317 		if (vol->offset == (hammer2_off_t)-1)
318 			errx(1, "%s has bad offset 0x%016jx", path,
319 			     (intmax_t)vol->offset);
320 		if (vol->size == (hammer2_off_t)-1)
321 			errx(1, "%s has bad size 0x%016jx", path,
322 			     (intmax_t)vol->size);
323 		/* check volume size vs block device size */
324 		size = check_volume(vol->fd);
325 		printf("checkvolu header %d %016jx/%016jx\n", i, vol->size, size);
326 		if (vol->size > size)
327 			errx(1, "%s's size 0x%016jx exceeds device size 0x%016jx",
328 			     path, (intmax_t)vol->size, size);
329 		if (vol->size == 0)
330 			errx(1, "%s has size of 0", path);
331 	}
332 	free(st);
333 }
334 
335 static void
hammer2_verify_volumes_1(hammer2_ondisk_t * fsp,const hammer2_volume_data_t * rootvoldata)336 hammer2_verify_volumes_1(hammer2_ondisk_t *fsp,
337 			 const hammer2_volume_data_t *rootvoldata)
338 {
339 	const hammer2_volume_t *vol;
340 	hammer2_off_t off;
341 	const char *path;
342 	int i, nvolumes = 0;
343 
344 	/* check initialized volume count */
345 	for (i = 0; i < HAMMER2_MAX_VOLUMES; ++i) {
346 		vol = &fsp->volumes[i];
347 		if (vol->id != -1)
348 			nvolumes++;
349 	}
350 	if (nvolumes != 1)
351 		errx(1, "Only 1 volume supported");
352 	fsp->nvolumes = nvolumes; /* adjust with actual count */
353 
354 	/* check volume header */
355 	if (rootvoldata) {
356 		if (rootvoldata->nvolumes)
357 			errx(1, "Volume count %d must be 0",
358 			     rootvoldata->nvolumes);
359 		if (rootvoldata->total_size)
360 			errx(1, "Total size 0x%016jx must be 0",
361 			     (intmax_t)rootvoldata->total_size);
362 		for (i = 0; i < HAMMER2_MAX_VOLUMES; ++i) {
363 			off = rootvoldata->volu_loff[i];
364 			if (off)
365 				errx(1, "Volume offset[%d] 0x%016jx must be 0",
366 				     i, (intmax_t)off);
367 		}
368 	}
369 
370 	/* check volume */
371 	vol = &fsp->volumes[HAMMER2_ROOT_VOLUME];
372 	path = vol->path;
373 	if (vol->id)
374 		errx(1, "%s has non zero id %d", path, vol->id);
375 	if (vol->offset)
376 		errx(1, "%s has non zero offset 0x%016jx", path,
377 		     (intmax_t)vol->offset);
378 	if (vol->size & HAMMER2_VOLUME_ALIGNMASK64)
379 		errx(1, "%s's size is not 0x%016jx aligned", path,
380 		     (intmax_t)HAMMER2_VOLUME_ALIGN);
381 }
382 
383 static void
hammer2_verify_volumes_2(const hammer2_ondisk_t * fsp,const hammer2_volume_data_t * rootvoldata)384 hammer2_verify_volumes_2(const hammer2_ondisk_t *fsp,
385 			 const hammer2_volume_data_t *rootvoldata)
386 {
387 	const hammer2_volume_t *vol;
388 	hammer2_off_t off;
389 	const char *path;
390 	int i, nvolumes = 0;
391 
392 	/* check initialized volume count */
393 	for (i = 0; i < HAMMER2_MAX_VOLUMES; ++i) {
394 		vol = &fsp->volumes[i];
395 		if (vol->id != -1)
396 			nvolumes++;
397 	}
398 	if (fsp->nvolumes != nvolumes)
399 		errx(1, "Volume count mismatch %d vs %d",
400 		     fsp->nvolumes, nvolumes);
401 
402 	/* check volume header */
403 	if (rootvoldata) {
404 		if (rootvoldata->nvolumes != fso.nvolumes)
405 			errx(1, "Volume header requires %d devices, %d specified",
406 			     rootvoldata->nvolumes, fso.nvolumes);
407 		if (rootvoldata->total_size != fso.total_size)
408 			errx(1, "Total size 0x%016jx does not equal sum of "
409 			     "volumes 0x%016jx",
410 			     rootvoldata->total_size, fso.total_size);
411 		for (i = 0; i < nvolumes; ++i) {
412 			off = rootvoldata->volu_loff[i];
413 			if (off == (hammer2_off_t)-1)
414 				errx(1, "Volume offset[%d] 0x%016jx must not be -1",
415 				     i, (intmax_t)off);
416 		}
417 		for (i = nvolumes; i < HAMMER2_MAX_VOLUMES; ++i) {
418 			off = rootvoldata->volu_loff[i];
419 			if (off != (hammer2_off_t)-1)
420 				errx(1, "Volume offset[%d] 0x%016jx must be -1",
421 				     i, (intmax_t)off);
422 		}
423 	}
424 
425 	/* check volumes */
426 	for (i = 0; i < HAMMER2_MAX_VOLUMES; ++i) {
427 		vol = &fsp->volumes[i];
428 		if (vol->id == -1)
429 			continue;
430 		path = vol->path;
431 		/* check offset */
432 		if (vol->offset & HAMMER2_FREEMAP_LEVEL1_MASK)
433 			errx(1, "%s's offset 0x%016jx not 0x%016jx aligned",
434 			     path, (intmax_t)vol->offset,
435 			     HAMMER2_FREEMAP_LEVEL1_SIZE);
436 		/* check vs previous volume */
437 		if (i) {
438 			if (vol->id != (vol-1)->id + 1)
439 				errx(1, "%s has inconsistent id %d", path,
440 				     vol->id);
441 			if (vol->offset != (vol-1)->offset + (vol-1)->size)
442 				errx(1, "%s has inconsistent offset 0x%016jx",
443 				     path, (intmax_t)vol->offset);
444 		} else { /* first */
445 			if (vol->offset)
446 				errx(1, "%s has non zero offset 0x%016jx", path,
447 				     (intmax_t)vol->offset);
448 		}
449 		/* check size for non-last and last volumes */
450 		if (i != fsp->nvolumes - 1) {
451 			if (vol->size < HAMMER2_FREEMAP_LEVEL1_SIZE)
452 				errx(1, "%s's size must be >= 0x%016jx", path,
453 				     (intmax_t)HAMMER2_FREEMAP_LEVEL1_SIZE);
454 			if (vol->size & HAMMER2_FREEMAP_LEVEL1_MASK)
455 				errx(1, "%s's size is not 0x%016jx aligned",
456 				     path,
457 				     (intmax_t)HAMMER2_FREEMAP_LEVEL1_SIZE);
458 		} else { /* last */
459 			if (vol->size & HAMMER2_VOLUME_ALIGNMASK64)
460 				errx(1, "%s's size is not 0x%016jx aligned",
461 				     path, (intmax_t)HAMMER2_VOLUME_ALIGN);
462 		}
463 	}
464 }
465 
466 void
hammer2_verify_volumes(hammer2_ondisk_t * fsp,const hammer2_volume_data_t * rootvoldata)467 hammer2_verify_volumes(hammer2_ondisk_t *fsp,
468 		       const hammer2_volume_data_t *rootvoldata)
469 {
470 	hammer2_verify_volumes_common(fsp, rootvoldata);
471 	if (fsp->version >= HAMMER2_VOL_VERSION_MULTI_VOLUMES)
472 		hammer2_verify_volumes_2(fsp, rootvoldata);
473 	else
474 		hammer2_verify_volumes_1(fsp, rootvoldata);
475 	assert(fsp->nvolumes > 0);
476 }
477 
478 void
hammer2_print_volumes(const hammer2_ondisk_t * fsp)479 hammer2_print_volumes(const hammer2_ondisk_t *fsp)
480 {
481 	const hammer2_volume_t *vol;
482 	int i, n, w = 0;
483 
484 	for (i = 0; i < fsp->nvolumes; ++i) {
485 		vol = &fsp->volumes[i];
486 		n = (int)strlen(vol->path);
487 		if (n > w)
488 			w = n;
489 	}
490 
491 	printf("total    %-*.*s 0x%016jx 0x%016jx\n",
492 		w, w, "", (intmax_t)0, (intmax_t)fsp->total_size);
493 
494 	for (i = 0; i < fsp->nvolumes; ++i) {
495 		vol = &fsp->volumes[i];
496 		printf("volume%-2d %-*.*s 0x%016jx 0x%016jx%s\n",
497 		       vol->id, w, w, vol->path, (intmax_t)vol->offset,
498 		       (intmax_t)vol->size,
499 		       (vol->id == HAMMER2_ROOT_VOLUME ?
500 		       " (root volume)" : ""));
501 	}
502 }
503 
504 void
hammer2_init_volumes(const char * blkdevs,int rdonly)505 hammer2_init_volumes(const char *blkdevs, int rdonly)
506 {
507 	hammer2_volume_data_t *rootvoldata;
508 	char *o, *p, *devpath;
509 
510 	if (hammer2_volumes_initialized)
511 		errx(1, "Already initialized");
512 	if (!blkdevs)
513 		errx(1, "NULL blkdevs");
514 
515 	hammer2_init_ondisk(&fso);
516 	o = p = strdup(blkdevs);
517 	while ((devpath = p) != NULL) {
518 		if ((p = strchr(p, ':')) != NULL)
519 			*p++ = 0;
520 		devpath = getdevpath(devpath, 0);
521 		if (strchr(devpath, ':'))
522 			hammer2_init_volumes(devpath, rdonly);
523 		else
524 			hammer2_add_volume(devpath, rdonly);
525 		free(devpath);
526 	}
527 	free(o);
528 	hammer2_volumes_initialized = 1;
529 
530 	rootvoldata = hammer2_read_root_volume_header();
531 	hammer2_verify_volumes(&fso, rootvoldata);
532 	free(rootvoldata);
533 }
534 
535 void
hammer2_cleanup_volumes(void)536 hammer2_cleanup_volumes(void)
537 {
538 	hammer2_volume_t *vol;
539 	int i;
540 
541 	for (i = 0; i < HAMMER2_MAX_VOLUMES; ++i) {
542 		vol = &fso.volumes[i];
543 		if (vol->id == -1)
544 			continue;
545 		hammer2_uninstall_volume(vol);
546 	}
547 	hammer2_volumes_initialized = 0;
548 }
549 
550 typedef void (*callback)(const hammer2_volume_t*, void *data);
551 
552 hammer2_volume_t *
hammer2_get_volume(hammer2_off_t offset)553 hammer2_get_volume(hammer2_off_t offset)
554 {
555 	hammer2_volume_t *vol;
556 	int i;
557 
558 	assert(hammer2_volumes_initialized == 1);
559 	offset &= ~HAMMER2_OFF_MASK_RADIX;
560 
561 	/* do binary search if users really use this many supported volumes */
562 	for (i = 0; i < fso.nvolumes; ++i) {
563 		vol = &fso.volumes[i];
564 		if ((offset >= vol->offset) &&
565 		    (offset < vol->offset + vol->size))
566 		{
567 			return vol;
568 		}
569 	}
570 	return NULL;
571 }
572 
573 static int
hammer2_get_volume_attr(hammer2_off_t offset,callback fn,void * data)574 hammer2_get_volume_attr(hammer2_off_t offset, callback fn, void *data)
575 {
576 	hammer2_volume_t *vol;
577 	int i;
578 
579 	assert(hammer2_volumes_initialized == 1);
580 	offset &= ~HAMMER2_OFF_MASK_RADIX;
581 
582 	/* do binary search if users really use this many supported volumes */
583 	for (i = 0; i < fso.nvolumes; ++i) {
584 		vol = &fso.volumes[i];
585 		if ((offset >= vol->offset) &&
586 		    (offset < vol->offset + vol->size)) {
587 			fn(vol, data);
588 			return(0);
589 		}
590 	}
591 
592 	return(-1);
593 }
594 
595 /* fd */
596 static void
hammer2_volume_fd_cb(const hammer2_volume_t * vol,void * data)597 hammer2_volume_fd_cb(const hammer2_volume_t *vol, void *data)
598 {
599 	*(int*)data = vol->fd;
600 }
601 
602 int
hammer2_get_volume_fd(hammer2_off_t offset)603 hammer2_get_volume_fd(hammer2_off_t offset)
604 {
605 	int ret = 0;
606 
607 	if (hammer2_get_volume_attr(offset, hammer2_volume_fd_cb, &ret) < 0)
608 		return(-1);
609 	return(ret);
610 }
611 
612 int
hammer2_get_root_volume_fd(void)613 hammer2_get_root_volume_fd(void)
614 {
615 	return(hammer2_get_volume_fd(0));
616 }
617 
618 /* id */
619 static void
hammer2_volume_id_cb(const hammer2_volume_t * vol,void * data)620 hammer2_volume_id_cb(const hammer2_volume_t *vol, void *data)
621 {
622 	*(int*)data = vol->id;
623 }
624 
625 int
hammer2_get_volume_id(hammer2_off_t offset)626 hammer2_get_volume_id(hammer2_off_t offset)
627 {
628 	int ret = 0;
629 
630 	if (hammer2_get_volume_attr(offset, hammer2_volume_id_cb, &ret) < 0)
631 		return(-1);
632 	return(ret);
633 }
634 
635 int
hammer2_get_root_volume_id(void)636 hammer2_get_root_volume_id(void)
637 {
638 	return(hammer2_get_volume_id(0));
639 }
640 
641 /* path */
642 static void
hammer2_volume_path_cb(const hammer2_volume_t * vol,void * data)643 hammer2_volume_path_cb(const hammer2_volume_t *vol, void *data)
644 {
645 	*(const char**)data = vol->path;
646 }
647 
648 const char *
hammer2_get_volume_path(hammer2_off_t offset)649 hammer2_get_volume_path(hammer2_off_t offset)
650 {
651 	const char *ret = NULL;
652 
653 	if (hammer2_get_volume_attr(offset, hammer2_volume_path_cb, &ret) < 0)
654 		return(NULL);
655 	return(ret);
656 }
657 
658 const char *
hammer2_get_root_volume_path(void)659 hammer2_get_root_volume_path(void)
660 {
661 	return(hammer2_get_volume_path(0));
662 }
663 
664 /* offset */
665 static void
hammer2_volume_offset_cb(const hammer2_volume_t * vol,void * data)666 hammer2_volume_offset_cb(const hammer2_volume_t *vol, void *data)
667 {
668 	*(hammer2_off_t*)data = vol->offset;
669 }
670 
671 hammer2_off_t
hammer2_get_volume_offset(hammer2_off_t offset)672 hammer2_get_volume_offset(hammer2_off_t offset)
673 {
674 	hammer2_off_t ret = 0;
675 
676 	if (hammer2_get_volume_attr(offset, hammer2_volume_offset_cb, &ret) < 0)
677 		return(-1);
678 	return(ret);
679 }
680 
681 hammer2_off_t
hammer2_get_root_volume_offset(void)682 hammer2_get_root_volume_offset(void)
683 {
684 	return(hammer2_get_volume_offset(0));
685 }
686 
687 /* size */
688 static void
hammer2_volume_size_cb(const hammer2_volume_t * vol,void * data)689 hammer2_volume_size_cb(const hammer2_volume_t *vol, void *data)
690 {
691 	*(hammer2_off_t*)data = vol->size;
692 }
693 
694 hammer2_off_t
hammer2_get_volume_size(hammer2_off_t offset)695 hammer2_get_volume_size(hammer2_off_t offset)
696 {
697 	hammer2_off_t ret = 0;
698 
699 	if (hammer2_get_volume_attr(offset, hammer2_volume_size_cb, &ret) < 0)
700 		return(-1);
701 	return(ret);
702 }
703 
704 hammer2_off_t
hammer2_get_root_volume_size(void)705 hammer2_get_root_volume_size(void)
706 {
707 	return(hammer2_get_volume_size(0));
708 }
709 
710 /* total size */
711 hammer2_off_t
hammer2_get_total_size(void)712 hammer2_get_total_size(void)
713 {
714 	return(fso.total_size);
715 }
716 
717 hammer2_volume_data_t*
hammer2_read_root_volume_header(void)718 hammer2_read_root_volume_header(void)
719 {
720 	hammer2_volume_data_t *voldata;
721 	int fd = hammer2_get_root_volume_fd();
722 	const char *path = hammer2_get_root_volume_path();
723 
724 	if (fd == -1)
725 		return(NULL);
726 
727 	voldata = calloc(1, sizeof(*voldata));
728 	if (hammer2_read_volume_header(fd, path, voldata) >= 0)
729 		return(voldata);
730 	else
731 		errx(1, "Failed to read volume header");
732 }
733