xref: /freebsd/sys/geom/mirror/g_mirror.h (revision aa1a8ff2d6dbc51ef058f46f3db5a8bb77967145)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2004-2006 Pawel Jakub Dawidek <pjd@FreeBSD.org>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #ifndef	_G_MIRROR_H_
30 #define	_G_MIRROR_H_
31 
32 #include <sys/endian.h>
33 #include <sys/md5.h>
34 
35 #define	G_MIRROR_CLASS_NAME	"MIRROR"
36 
37 #define	G_MIRROR_MAGIC		"GEOM::MIRROR"
38 /*
39  * Version history:
40  * 0 - Initial version number.
41  * 1 - Added 'prefer' balance algorithm.
42  * 2 - Added md_genid field to metadata.
43  * 3 - Added md_provsize field to metadata.
44  * 4 - Added 'no failure synchronization' flag.
45  */
46 #define	G_MIRROR_VERSION	4
47 
48 #define	G_MIRROR_BALANCE_NONE		0
49 #define	G_MIRROR_BALANCE_ROUND_ROBIN	1
50 #define	G_MIRROR_BALANCE_LOAD		2
51 #define	G_MIRROR_BALANCE_SPLIT		3
52 #define	G_MIRROR_BALANCE_PREFER		4
53 #define	G_MIRROR_BALANCE_MIN		G_MIRROR_BALANCE_NONE
54 #define	G_MIRROR_BALANCE_MAX		G_MIRROR_BALANCE_PREFER
55 
56 #define	G_MIRROR_DISK_FLAG_DIRTY		0x0000000000000001ULL
57 #define	G_MIRROR_DISK_FLAG_SYNCHRONIZING	0x0000000000000002ULL
58 #define	G_MIRROR_DISK_FLAG_FORCE_SYNC		0x0000000000000004ULL
59 #define	G_MIRROR_DISK_FLAG_INACTIVE		0x0000000000000008ULL
60 #define	G_MIRROR_DISK_FLAG_HARDCODED		0x0000000000000010ULL
61 #define	G_MIRROR_DISK_FLAG_BROKEN		0x0000000000000020ULL
62 #define	G_MIRROR_DISK_FLAG_CANDELETE		0x0000000000000040ULL
63 
64 /* Per-disk flags which are recorded in on-disk metadata. */
65 #define	G_MIRROR_DISK_FLAG_MASK		(G_MIRROR_DISK_FLAG_DIRTY |	\
66 					 G_MIRROR_DISK_FLAG_SYNCHRONIZING | \
67 					 G_MIRROR_DISK_FLAG_FORCE_SYNC | \
68 					 G_MIRROR_DISK_FLAG_INACTIVE | \
69 					 G_MIRROR_DISK_FLAG_CANDELETE)
70 
71 #define	G_MIRROR_DEVICE_FLAG_NOAUTOSYNC	0x0000000000000001ULL
72 #define	G_MIRROR_DEVICE_FLAG_NOFAILSYNC	0x0000000000000002ULL
73 
74 /* Mirror flags which are recorded in on-disk metadata. */
75 #define	G_MIRROR_DEVICE_FLAG_MASK	(G_MIRROR_DEVICE_FLAG_NOAUTOSYNC | \
76 					 G_MIRROR_DEVICE_FLAG_NOFAILSYNC)
77 
78 #ifdef _KERNEL
79 #define	G_MIRROR_DEVICE_FLAG_DESTROY	0x0100000000000000ULL
80 #define	G_MIRROR_DEVICE_FLAG_DRAIN	0x0200000000000000ULL
81 #define	G_MIRROR_DEVICE_FLAG_CLOSEWAIT	0x0400000000000000ULL
82 #define	G_MIRROR_DEVICE_FLAG_TASTING	0x0800000000000000ULL
83 #define	G_MIRROR_DEVICE_FLAG_WIPE	0x1000000000000000ULL
84 
85 extern int g_mirror_debug;
86 
87 #define G_MIRROR_DEBUG(lvl, ...) \
88     _GEOM_DEBUG("GEOM_MIRROR", g_mirror_debug, (lvl), NULL, __VA_ARGS__)
89 #define G_MIRROR_LOGREQ(lvl, bp, ...) \
90     _GEOM_DEBUG("GEOM_MIRROR", g_mirror_debug, (lvl), (bp), __VA_ARGS__)
91 
92 #define	G_MIRROR_BIO_FLAG_REGULAR	0x01
93 #define	G_MIRROR_BIO_FLAG_SYNC		0x02
94 
95 /*
96  * Informations needed for synchronization.
97  */
98 struct g_mirror_disk_sync {
99 	struct g_consumer *ds_consumer;	/* Consumer connected to our mirror. */
100 	off_t		  ds_offset;	/* Offset of next request to send. */
101 	off_t		  ds_offset_done; /* Offset of already synchronized
102 					   region. */
103 	time_t		  ds_update_ts; /* Time of last metadata update. */
104 	u_int		  ds_syncid;	/* Disk's synchronization ID. */
105 	u_int		  ds_inflight;	/* Number of in-flight sync requests. */
106 	struct bio	**ds_bios;	/* BIOs for synchronization I/O. */
107 };
108 
109 /*
110  * Informations needed for synchronization.
111  */
112 struct g_mirror_device_sync {
113 	struct g_geom	*ds_geom;	/* Synchronization geom. */
114 	u_int		 ds_ndisks;	/* Number of disks in SYNCHRONIZING
115 					   state. */
116 };
117 
118 #define	G_MIRROR_DISK_STATE_NONE		0
119 #define	G_MIRROR_DISK_STATE_NEW			1
120 #define	G_MIRROR_DISK_STATE_ACTIVE		2
121 #define	G_MIRROR_DISK_STATE_STALE		3
122 #define	G_MIRROR_DISK_STATE_SYNCHRONIZING	4
123 #define	G_MIRROR_DISK_STATE_DISCONNECTED	5
124 #define	G_MIRROR_DISK_STATE_DESTROY		6
125 struct g_mirror_disk {
126 	uint32_t	 d_id;		/* Disk ID. */
127 	struct g_consumer *d_consumer;	/* Consumer. */
128 	struct g_mirror_softc	*d_softc; /* Back-pointer to softc. */
129 	int		 d_state;	/* Disk state. */
130 	u_int		 d_priority;	/* Disk priority. */
131 	u_int		 load;		/* Averaged queue length */
132 	off_t		 d_last_offset;	/* Last read offset */
133 	uint64_t	 d_flags;	/* Additional flags. */
134 	u_int		 d_genid;	/* Disk's generation ID. */
135 	struct g_mirror_disk_sync d_sync;/* Sync information. */
136 	LIST_ENTRY(g_mirror_disk) d_next;
137 	u_int		 d_init_ndisks;	/* Initial number of mirror components */
138 	uint32_t	 d_init_slice;	/* Initial slice size */
139 	uint8_t		 d_init_balance;/* Initial balance */
140 	uint16_t	 d_rotation_rate;/* Disk's rotation rate */
141 	uint64_t	 d_init_mediasize;/* Initial mediasize */
142 };
143 #define	d_name	d_consumer->provider->name
144 
145 #define	G_MIRROR_EVENT_DONTWAIT	0x1
146 #define	G_MIRROR_EVENT_WAIT	0x2
147 #define	G_MIRROR_EVENT_DEVICE	0x4
148 #define	G_MIRROR_EVENT_DONE	0x8
149 struct g_mirror_event {
150 	struct g_mirror_disk	*e_disk;
151 	int			 e_state;
152 	int			 e_flags;
153 	int			 e_error;
154 	TAILQ_ENTRY(g_mirror_event) e_next;
155 };
156 
157 #define	G_MIRROR_DEVICE_STATE_STARTING		0
158 #define	G_MIRROR_DEVICE_STATE_RUNNING		1
159 
160 #define	G_MIRROR_TYPE_MANUAL	0
161 #define	G_MIRROR_TYPE_AUTOMATIC	1
162 
163 /* Bump syncid on first write. */
164 #define	G_MIRROR_BUMP_SYNCID		0x1
165 /* Bump genid immediately. */
166 #define	G_MIRROR_BUMP_GENID		0x2
167 /* Bump syncid immediately. */
168 #define	G_MIRROR_BUMP_SYNCID_NOW	0x4
169 struct g_mirror_softc {
170 	u_int		sc_type;	/* Device type (manual/automatic). */
171 	u_int		sc_state;	/* Device state. */
172 	uint32_t	sc_slice;	/* Slice size. */
173 	uint8_t		sc_balance;	/* Balance algorithm. */
174 	uint64_t	sc_mediasize;	/* Device size. */
175 	uint32_t	sc_sectorsize;	/* Sector size. */
176 	uint64_t	sc_flags;	/* Additional flags. */
177 
178 	struct g_geom	*sc_geom;
179 	struct g_provider *sc_provider;
180 	int		sc_provider_open;
181 
182 	uint32_t	sc_id;		/* Mirror unique ID. */
183 
184 	struct sx	 sc_lock;
185 	struct bio_queue sc_queue;
186 	struct mtx	 sc_queue_mtx;
187 	struct proc	*sc_worker;
188 	struct bio_queue sc_inflight; /* In-flight regular write requests. */
189 	struct bio_queue sc_regular_delayed; /* Delayed I/O requests due to
190 						collision with sync requests. */
191 	struct bio_queue sc_sync_delayed; /* Delayed sync requests due to
192 					     collision with regular requests. */
193 
194 	LIST_HEAD(, g_mirror_disk) sc_disks;
195 	u_int		sc_ndisks;	/* Number of disks. */
196 	struct g_mirror_disk *sc_hint;
197 
198 	u_int		sc_genid;	/* Generation ID. */
199 	u_int		sc_syncid;	/* Synchronization ID. */
200 	int		sc_bump_id;
201 	struct g_mirror_device_sync sc_sync;
202 	int		sc_idle;	/* DIRTY flags removed. */
203 	time_t		sc_last_write;
204 	u_int		sc_writes;
205 	u_int		sc_refcnt;	/* Number of softc references */
206 
207 	TAILQ_HEAD(, g_mirror_event) sc_events;
208 	struct mtx	sc_events_mtx;
209 	struct g_mirror_event *sc_timeout_event;
210 
211 	struct callout	sc_callout;
212 
213 	struct root_hold_token *sc_rootmount;
214 
215 	struct mtx	 sc_done_mtx;
216 };
217 #define	sc_name	sc_geom->name
218 
219 struct g_mirror_metadata;
220 
221 u_int g_mirror_ndisks(struct g_mirror_softc *sc, int state);
222 struct g_geom * g_mirror_create(struct g_class *mp,
223     const struct g_mirror_metadata *md, u_int type);
224 #define	G_MIRROR_DESTROY_SOFT		0
225 #define	G_MIRROR_DESTROY_DELAYED	1
226 #define	G_MIRROR_DESTROY_HARD		2
227 int g_mirror_destroy(struct g_mirror_softc *sc, int how);
228 int g_mirror_event_send(void *arg, int state, int flags);
229 struct g_mirror_metadata;
230 int g_mirror_add_disk(struct g_mirror_softc *sc, struct g_provider *pp,
231     struct g_mirror_metadata *md);
232 int g_mirror_read_metadata(struct g_consumer *cp, struct g_mirror_metadata *md);
233 void g_mirror_fill_metadata(struct g_mirror_softc *sc,
234     struct g_mirror_disk *disk, struct g_mirror_metadata *md);
235 void g_mirror_update_metadata(struct g_mirror_disk *disk);
236 
237 g_ctl_req_t g_mirror_config;
238 #endif	/* _KERNEL */
239 
240 struct g_mirror_metadata {
241 	char		md_magic[16];	/* Magic value. */
242 	uint32_t	md_version;	/* Version number. */
243 	char		md_name[16];	/* Mirror name. */
244 	uint32_t	md_mid;		/* Mirror unique ID. */
245 	uint32_t	md_did;		/* Disk unique ID. */
246 	uint8_t		md_all;		/* Number of disks in mirror. */
247 	uint32_t	md_genid;	/* Generation ID. */
248 	uint32_t	md_syncid;	/* Synchronization ID. */
249 	uint8_t		md_priority;	/* Disk priority. */
250 	uint32_t	md_slice;	/* Slice size. */
251 	uint8_t		md_balance;	/* Balance type. */
252 	uint64_t	md_mediasize;	/* Size of the smallest
253 					   disk in mirror. */
254 	uint32_t	md_sectorsize;	/* Sector size. */
255 	uint64_t	md_sync_offset;	/* Synchronized offset. */
256 	uint64_t	md_mflags;	/* Additional mirror flags. */
257 	uint64_t	md_dflags;	/* Additional disk flags. */
258 	char		md_provider[16]; /* Hardcoded provider. */
259 	uint64_t	md_provsize;	/* Provider's size. */
260 	u_char		md_hash[16];	/* MD5 hash. */
261 };
262 static __inline void
263 mirror_metadata_encode(struct g_mirror_metadata *md, u_char *data)
264 {
265 	MD5_CTX ctx;
266 
267 	bcopy(md->md_magic, data, 16);
268 	le32enc(data + 16, md->md_version);
269 	bcopy(md->md_name, data + 20, 16);
270 	le32enc(data + 36, md->md_mid);
271 	le32enc(data + 40, md->md_did);
272 	*(data + 44) = md->md_all;
273 	le32enc(data + 45, md->md_genid);
274 	le32enc(data + 49, md->md_syncid);
275 	*(data + 53) = md->md_priority;
276 	le32enc(data + 54, md->md_slice);
277 	*(data + 58) = md->md_balance;
278 	le64enc(data + 59, md->md_mediasize);
279 	le32enc(data + 67, md->md_sectorsize);
280 	le64enc(data + 71, md->md_sync_offset);
281 	le64enc(data + 79, md->md_mflags);
282 	le64enc(data + 87, md->md_dflags);
283 	bcopy(md->md_provider, data + 95, 16);
284 	le64enc(data + 111, md->md_provsize);
285 	MD5Init(&ctx);
286 	MD5Update(&ctx, data, 119);
287 	MD5Final(md->md_hash, &ctx);
288 	bcopy(md->md_hash, data + 119, 16);
289 }
290 static __inline int
291 mirror_metadata_decode_v0v1(const u_char *data, struct g_mirror_metadata *md)
292 {
293 	MD5_CTX ctx;
294 
295 	bcopy(data + 20, md->md_name, 16);
296 	md->md_mid = le32dec(data + 36);
297 	md->md_did = le32dec(data + 40);
298 	md->md_all = *(data + 44);
299 	md->md_syncid = le32dec(data + 45);
300 	md->md_priority = *(data + 49);
301 	md->md_slice = le32dec(data + 50);
302 	md->md_balance = *(data + 54);
303 	md->md_mediasize = le64dec(data + 55);
304 	md->md_sectorsize = le32dec(data + 63);
305 	md->md_sync_offset = le64dec(data + 67);
306 	md->md_mflags = le64dec(data + 75);
307 	md->md_dflags = le64dec(data + 83);
308 	bcopy(data + 91, md->md_provider, 16);
309 	bcopy(data + 107, md->md_hash, 16);
310 	MD5Init(&ctx);
311 	MD5Update(&ctx, data, 107);
312 	MD5Final(md->md_hash, &ctx);
313 	if (bcmp(md->md_hash, data + 107, 16) != 0)
314 		return (EINVAL);
315 
316 	/* New fields. */
317 	md->md_genid = 0;
318 	md->md_provsize = 0;
319 
320 	return (0);
321 }
322 static __inline int
323 mirror_metadata_decode_v2(const u_char *data, struct g_mirror_metadata *md)
324 {
325 	MD5_CTX ctx;
326 
327 	bcopy(data + 20, md->md_name, 16);
328 	md->md_mid = le32dec(data + 36);
329 	md->md_did = le32dec(data + 40);
330 	md->md_all = *(data + 44);
331 	md->md_genid = le32dec(data + 45);
332 	md->md_syncid = le32dec(data + 49);
333 	md->md_priority = *(data + 53);
334 	md->md_slice = le32dec(data + 54);
335 	md->md_balance = *(data + 58);
336 	md->md_mediasize = le64dec(data + 59);
337 	md->md_sectorsize = le32dec(data + 67);
338 	md->md_sync_offset = le64dec(data + 71);
339 	md->md_mflags = le64dec(data + 79);
340 	md->md_dflags = le64dec(data + 87);
341 	bcopy(data + 95, md->md_provider, 16);
342 	bcopy(data + 111, md->md_hash, 16);
343 	MD5Init(&ctx);
344 	MD5Update(&ctx, data, 111);
345 	MD5Final(md->md_hash, &ctx);
346 	if (bcmp(md->md_hash, data + 111, 16) != 0)
347 		return (EINVAL);
348 
349 	/* New fields. */
350 	md->md_provsize = 0;
351 
352 	return (0);
353 }
354 static __inline int
355 mirror_metadata_decode_v3v4(const u_char *data, struct g_mirror_metadata *md)
356 {
357 	MD5_CTX ctx;
358 
359 	bcopy(data + 20, md->md_name, 16);
360 	md->md_mid = le32dec(data + 36);
361 	md->md_did = le32dec(data + 40);
362 	md->md_all = *(data + 44);
363 	md->md_genid = le32dec(data + 45);
364 	md->md_syncid = le32dec(data + 49);
365 	md->md_priority = *(data + 53);
366 	md->md_slice = le32dec(data + 54);
367 	md->md_balance = *(data + 58);
368 	md->md_mediasize = le64dec(data + 59);
369 	md->md_sectorsize = le32dec(data + 67);
370 	md->md_sync_offset = le64dec(data + 71);
371 	md->md_mflags = le64dec(data + 79);
372 	md->md_dflags = le64dec(data + 87);
373 	bcopy(data + 95, md->md_provider, 16);
374 	md->md_provsize = le64dec(data + 111);
375 	bcopy(data + 119, md->md_hash, 16);
376 	MD5Init(&ctx);
377 	MD5Update(&ctx, data, 119);
378 	MD5Final(md->md_hash, &ctx);
379 	if (bcmp(md->md_hash, data + 119, 16) != 0)
380 		return (EINVAL);
381 	return (0);
382 }
383 static __inline int
384 mirror_metadata_decode(const u_char *data, struct g_mirror_metadata *md)
385 {
386 	int error;
387 
388 	bcopy(data, md->md_magic, 16);
389 	md->md_version = le32dec(data + 16);
390 	switch (md->md_version) {
391 	case 0:
392 	case 1:
393 		error = mirror_metadata_decode_v0v1(data, md);
394 		break;
395 	case 2:
396 		error = mirror_metadata_decode_v2(data, md);
397 		break;
398 	case 3:
399 	case 4:
400 		error = mirror_metadata_decode_v3v4(data, md);
401 		break;
402 	default:
403 		error = EINVAL;
404 		break;
405 	}
406 	return (error);
407 }
408 
409 static __inline const char *
410 balance_name(u_int balance)
411 {
412 	static const char *algorithms[] = {
413 		[G_MIRROR_BALANCE_NONE] = "none",
414 		[G_MIRROR_BALANCE_ROUND_ROBIN] = "round-robin",
415 		[G_MIRROR_BALANCE_LOAD] = "load",
416 		[G_MIRROR_BALANCE_SPLIT] = "split",
417 		[G_MIRROR_BALANCE_PREFER] = "prefer",
418 		[G_MIRROR_BALANCE_MAX + 1] = "unknown"
419 	};
420 
421 	if (balance > G_MIRROR_BALANCE_MAX)
422 		balance = G_MIRROR_BALANCE_MAX + 1;
423 
424 	return (algorithms[balance]);
425 }
426 
427 static __inline int
428 balance_id(const char *name)
429 {
430 	static const char *algorithms[] = {
431 		[G_MIRROR_BALANCE_NONE] = "none",
432 		[G_MIRROR_BALANCE_ROUND_ROBIN] = "round-robin",
433 		[G_MIRROR_BALANCE_LOAD] = "load",
434 		[G_MIRROR_BALANCE_SPLIT] = "split",
435 		[G_MIRROR_BALANCE_PREFER] = "prefer"
436 	};
437 	int n;
438 
439 	for (n = G_MIRROR_BALANCE_MIN; n <= G_MIRROR_BALANCE_MAX; n++) {
440 		if (strcmp(name, algorithms[n]) == 0)
441 			return (n);
442 	}
443 	return (-1);
444 }
445 
446 static __inline void
447 mirror_metadata_dump(const struct g_mirror_metadata *md)
448 {
449 	static const char hex[] = "0123456789abcdef";
450 	char hash[16 * 2 + 1];
451 	u_int i;
452 
453 	printf("     magic: %s\n", md->md_magic);
454 	printf("   version: %u\n", (u_int)md->md_version);
455 	printf("      name: %s\n", md->md_name);
456 	printf("       mid: %u\n", (u_int)md->md_mid);
457 	printf("       did: %u\n", (u_int)md->md_did);
458 	printf("       all: %u\n", (u_int)md->md_all);
459 	printf("     genid: %u\n", (u_int)md->md_genid);
460 	printf("    syncid: %u\n", (u_int)md->md_syncid);
461 	printf("  priority: %u\n", (u_int)md->md_priority);
462 	printf("     slice: %u\n", (u_int)md->md_slice);
463 	printf("   balance: %s\n", balance_name((u_int)md->md_balance));
464 	printf(" mediasize: %jd\n", (intmax_t)md->md_mediasize);
465 	printf("sectorsize: %u\n", (u_int)md->md_sectorsize);
466 	printf("syncoffset: %jd\n", (intmax_t)md->md_sync_offset);
467 	printf("    mflags:");
468 	if (md->md_mflags == 0)
469 		printf(" NONE");
470 	else {
471 		if ((md->md_mflags & G_MIRROR_DEVICE_FLAG_NOFAILSYNC) != 0)
472 			printf(" NOFAILSYNC");
473 		if ((md->md_mflags & G_MIRROR_DEVICE_FLAG_NOAUTOSYNC) != 0)
474 			printf(" NOAUTOSYNC");
475 	}
476 	printf("\n");
477 	printf("    dflags:");
478 	if (md->md_dflags == 0)
479 		printf(" NONE");
480 	else {
481 		if ((md->md_dflags & G_MIRROR_DISK_FLAG_DIRTY) != 0)
482 			printf(" DIRTY");
483 		if ((md->md_dflags & G_MIRROR_DISK_FLAG_SYNCHRONIZING) != 0)
484 			printf(" SYNCHRONIZING");
485 		if ((md->md_dflags & G_MIRROR_DISK_FLAG_FORCE_SYNC) != 0)
486 			printf(" FORCE_SYNC");
487 		if ((md->md_dflags & G_MIRROR_DISK_FLAG_INACTIVE) != 0)
488 			printf(" INACTIVE");
489 	}
490 	printf("\n");
491 	printf("hcprovider: %s\n", md->md_provider);
492 	printf("  provsize: %ju\n", (uintmax_t)md->md_provsize);
493 	bzero(hash, sizeof(hash));
494 	for (i = 0; i < 16; i++) {
495 		hash[i * 2] = hex[md->md_hash[i] >> 4];
496 		hash[i * 2 + 1] = hex[md->md_hash[i] & 0x0f];
497 	}
498 	printf("  MD5 hash: %s\n", hash);
499 }
500 #endif	/* !_G_MIRROR_H_ */
501