xref: /freebsd/sys/geom/mirror/g_mirror.h (revision fe6060f10f634930ff71b7c50291ddc610da2475)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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  * $FreeBSD$
29  */
30 
31 #ifndef	_G_MIRROR_H_
32 #define	_G_MIRROR_H_
33 
34 #include <sys/endian.h>
35 #include <sys/md5.h>
36 
37 #define	G_MIRROR_CLASS_NAME	"MIRROR"
38 
39 #define	G_MIRROR_MAGIC		"GEOM::MIRROR"
40 /*
41  * Version history:
42  * 0 - Initial version number.
43  * 1 - Added 'prefer' balance algorithm.
44  * 2 - Added md_genid field to metadata.
45  * 3 - Added md_provsize field to metadata.
46  * 4 - Added 'no failure synchronization' flag.
47  */
48 #define	G_MIRROR_VERSION	4
49 
50 #define	G_MIRROR_BALANCE_NONE		0
51 #define	G_MIRROR_BALANCE_ROUND_ROBIN	1
52 #define	G_MIRROR_BALANCE_LOAD		2
53 #define	G_MIRROR_BALANCE_SPLIT		3
54 #define	G_MIRROR_BALANCE_PREFER		4
55 #define	G_MIRROR_BALANCE_MIN		G_MIRROR_BALANCE_NONE
56 #define	G_MIRROR_BALANCE_MAX		G_MIRROR_BALANCE_PREFER
57 
58 #define	G_MIRROR_DISK_FLAG_DIRTY		0x0000000000000001ULL
59 #define	G_MIRROR_DISK_FLAG_SYNCHRONIZING	0x0000000000000002ULL
60 #define	G_MIRROR_DISK_FLAG_FORCE_SYNC		0x0000000000000004ULL
61 #define	G_MIRROR_DISK_FLAG_INACTIVE		0x0000000000000008ULL
62 #define	G_MIRROR_DISK_FLAG_HARDCODED		0x0000000000000010ULL
63 #define	G_MIRROR_DISK_FLAG_BROKEN		0x0000000000000020ULL
64 #define	G_MIRROR_DISK_FLAG_CANDELETE		0x0000000000000040ULL
65 
66 /* Per-disk flags which are recorded in on-disk metadata. */
67 #define	G_MIRROR_DISK_FLAG_MASK		(G_MIRROR_DISK_FLAG_DIRTY |	\
68 					 G_MIRROR_DISK_FLAG_SYNCHRONIZING | \
69 					 G_MIRROR_DISK_FLAG_FORCE_SYNC | \
70 					 G_MIRROR_DISK_FLAG_INACTIVE | \
71 					 G_MIRROR_DISK_FLAG_CANDELETE)
72 
73 #define	G_MIRROR_DEVICE_FLAG_NOAUTOSYNC	0x0000000000000001ULL
74 #define	G_MIRROR_DEVICE_FLAG_NOFAILSYNC	0x0000000000000002ULL
75 
76 /* Mirror flags which are recorded in on-disk metadata. */
77 #define	G_MIRROR_DEVICE_FLAG_MASK	(G_MIRROR_DEVICE_FLAG_NOAUTOSYNC | \
78 					 G_MIRROR_DEVICE_FLAG_NOFAILSYNC)
79 
80 #ifdef _KERNEL
81 #define	G_MIRROR_DEVICE_FLAG_DESTROY	0x0100000000000000ULL
82 #define	G_MIRROR_DEVICE_FLAG_DRAIN	0x0200000000000000ULL
83 #define	G_MIRROR_DEVICE_FLAG_CLOSEWAIT	0x0400000000000000ULL
84 #define	G_MIRROR_DEVICE_FLAG_TASTING	0x0800000000000000ULL
85 #define	G_MIRROR_DEVICE_FLAG_WIPE	0x1000000000000000ULL
86 
87 extern int g_mirror_debug;
88 
89 #define G_MIRROR_DEBUG(lvl, ...) \
90     _GEOM_DEBUG("GEOM_MIRROR", g_mirror_debug, (lvl), NULL, __VA_ARGS__)
91 #define G_MIRROR_LOGREQ(lvl, bp, ...) \
92     _GEOM_DEBUG("GEOM_MIRROR", g_mirror_debug, (lvl), (bp), __VA_ARGS__)
93 
94 #define	G_MIRROR_BIO_FLAG_REGULAR	0x01
95 #define	G_MIRROR_BIO_FLAG_SYNC		0x02
96 
97 /*
98  * Informations needed for synchronization.
99  */
100 struct g_mirror_disk_sync {
101 	struct g_consumer *ds_consumer;	/* Consumer connected to our mirror. */
102 	off_t		  ds_offset;	/* Offset of next request to send. */
103 	off_t		  ds_offset_done; /* Offset of already synchronized
104 					   region. */
105 	time_t		  ds_update_ts; /* Time of last metadata update. */
106 	u_int		  ds_syncid;	/* Disk's synchronization ID. */
107 	u_int		  ds_inflight;	/* Number of in-flight sync requests. */
108 	struct bio	**ds_bios;	/* BIOs for synchronization I/O. */
109 };
110 
111 /*
112  * Informations needed for synchronization.
113  */
114 struct g_mirror_device_sync {
115 	struct g_geom	*ds_geom;	/* Synchronization geom. */
116 	u_int		 ds_ndisks;	/* Number of disks in SYNCHRONIZING
117 					   state. */
118 };
119 
120 #define	G_MIRROR_DISK_STATE_NONE		0
121 #define	G_MIRROR_DISK_STATE_NEW			1
122 #define	G_MIRROR_DISK_STATE_ACTIVE		2
123 #define	G_MIRROR_DISK_STATE_STALE		3
124 #define	G_MIRROR_DISK_STATE_SYNCHRONIZING	4
125 #define	G_MIRROR_DISK_STATE_DISCONNECTED	5
126 #define	G_MIRROR_DISK_STATE_DESTROY		6
127 struct g_mirror_disk {
128 	uint32_t	 d_id;		/* Disk ID. */
129 	struct g_consumer *d_consumer;	/* Consumer. */
130 	struct g_mirror_softc	*d_softc; /* Back-pointer to softc. */
131 	int		 d_state;	/* Disk state. */
132 	u_int		 d_priority;	/* Disk priority. */
133 	u_int		 load;		/* Averaged queue length */
134 	off_t		 d_last_offset;	/* Last read offset */
135 	uint64_t	 d_flags;	/* Additional flags. */
136 	u_int		 d_genid;	/* Disk's generation ID. */
137 	struct g_mirror_disk_sync d_sync;/* Sync information. */
138 	LIST_ENTRY(g_mirror_disk) d_next;
139 	u_int		 d_init_ndisks;	/* Initial number of mirror components */
140 	uint32_t	 d_init_slice;	/* Initial slice size */
141 	uint8_t		 d_init_balance;/* Initial balance */
142 	uint64_t	 d_init_mediasize;/* Initial mediasize */
143 };
144 #define	d_name	d_consumer->provider->name
145 
146 #define	G_MIRROR_EVENT_DONTWAIT	0x1
147 #define	G_MIRROR_EVENT_WAIT	0x2
148 #define	G_MIRROR_EVENT_DEVICE	0x4
149 #define	G_MIRROR_EVENT_DONE	0x8
150 struct g_mirror_event {
151 	struct g_mirror_disk	*e_disk;
152 	int			 e_state;
153 	int			 e_flags;
154 	int			 e_error;
155 	TAILQ_ENTRY(g_mirror_event) e_next;
156 };
157 
158 #define	G_MIRROR_DEVICE_STATE_STARTING		0
159 #define	G_MIRROR_DEVICE_STATE_RUNNING		1
160 
161 #define	G_MIRROR_TYPE_MANUAL	0
162 #define	G_MIRROR_TYPE_AUTOMATIC	1
163 
164 /* Bump syncid on first write. */
165 #define	G_MIRROR_BUMP_SYNCID		0x1
166 /* Bump genid immediately. */
167 #define	G_MIRROR_BUMP_GENID		0x2
168 /* Bump syncid immediately. */
169 #define	G_MIRROR_BUMP_SYNCID_NOW	0x4
170 struct g_mirror_softc {
171 	u_int		sc_type;	/* Device type (manual/automatic). */
172 	u_int		sc_state;	/* Device state. */
173 	uint32_t	sc_slice;	/* Slice size. */
174 	uint8_t		sc_balance;	/* Balance algorithm. */
175 	uint64_t	sc_mediasize;	/* Device size. */
176 	uint32_t	sc_sectorsize;	/* Sector size. */
177 	uint64_t	sc_flags;	/* Additional flags. */
178 
179 	struct g_geom	*sc_geom;
180 	struct g_provider *sc_provider;
181 	int		sc_provider_open;
182 
183 	uint32_t	sc_id;		/* Mirror unique ID. */
184 
185 	struct sx	 sc_lock;
186 	struct bio_queue sc_queue;
187 	struct mtx	 sc_queue_mtx;
188 	struct proc	*sc_worker;
189 	struct bio_queue sc_inflight; /* In-flight regular write requests. */
190 	struct bio_queue sc_regular_delayed; /* Delayed I/O requests due to
191 						collision with sync requests. */
192 	struct bio_queue sc_sync_delayed; /* Delayed sync requests due to
193 					     collision with regular requests. */
194 
195 	LIST_HEAD(, g_mirror_disk) sc_disks;
196 	u_int		sc_ndisks;	/* Number of disks. */
197 	struct g_mirror_disk *sc_hint;
198 
199 	u_int		sc_genid;	/* Generation ID. */
200 	u_int		sc_syncid;	/* Synchronization ID. */
201 	int		sc_bump_id;
202 	struct g_mirror_device_sync sc_sync;
203 	int		sc_idle;	/* DIRTY flags removed. */
204 	time_t		sc_last_write;
205 	u_int		sc_writes;
206 	u_int		sc_refcnt;	/* Number of softc references */
207 
208 	TAILQ_HEAD(, g_mirror_event) sc_events;
209 	struct mtx	sc_events_mtx;
210 	struct g_mirror_event *sc_timeout_event;
211 
212 	struct callout	sc_callout;
213 
214 	struct root_hold_token *sc_rootmount;
215 
216 	struct mtx	 sc_done_mtx;
217 };
218 #define	sc_name	sc_geom->name
219 
220 struct g_mirror_metadata;
221 
222 u_int g_mirror_ndisks(struct g_mirror_softc *sc, int state);
223 struct g_geom * g_mirror_create(struct g_class *mp,
224     const struct g_mirror_metadata *md, u_int type);
225 #define	G_MIRROR_DESTROY_SOFT		0
226 #define	G_MIRROR_DESTROY_DELAYED	1
227 #define	G_MIRROR_DESTROY_HARD		2
228 int g_mirror_destroy(struct g_mirror_softc *sc, int how);
229 int g_mirror_event_send(void *arg, int state, int flags);
230 struct g_mirror_metadata;
231 int g_mirror_add_disk(struct g_mirror_softc *sc, struct g_provider *pp,
232     struct g_mirror_metadata *md);
233 int g_mirror_read_metadata(struct g_consumer *cp, struct g_mirror_metadata *md);
234 void g_mirror_fill_metadata(struct g_mirror_softc *sc,
235     struct g_mirror_disk *disk, struct g_mirror_metadata *md);
236 void g_mirror_update_metadata(struct g_mirror_disk *disk);
237 
238 g_ctl_req_t g_mirror_config;
239 #endif	/* _KERNEL */
240 
241 struct g_mirror_metadata {
242 	char		md_magic[16];	/* Magic value. */
243 	uint32_t	md_version;	/* Version number. */
244 	char		md_name[16];	/* Mirror name. */
245 	uint32_t	md_mid;		/* Mirror unique ID. */
246 	uint32_t	md_did;		/* Disk unique ID. */
247 	uint8_t		md_all;		/* Number of disks in mirror. */
248 	uint32_t	md_genid;	/* Generation ID. */
249 	uint32_t	md_syncid;	/* Synchronization ID. */
250 	uint8_t		md_priority;	/* Disk priority. */
251 	uint32_t	md_slice;	/* Slice size. */
252 	uint8_t		md_balance;	/* Balance type. */
253 	uint64_t	md_mediasize;	/* Size of the smallest
254 					   disk in mirror. */
255 	uint32_t	md_sectorsize;	/* Sector size. */
256 	uint64_t	md_sync_offset;	/* Synchronized offset. */
257 	uint64_t	md_mflags;	/* Additional mirror flags. */
258 	uint64_t	md_dflags;	/* Additional disk flags. */
259 	char		md_provider[16]; /* Hardcoded provider. */
260 	uint64_t	md_provsize;	/* Provider's size. */
261 	u_char		md_hash[16];	/* MD5 hash. */
262 };
263 static __inline void
264 mirror_metadata_encode(struct g_mirror_metadata *md, u_char *data)
265 {
266 	MD5_CTX ctx;
267 
268 	bcopy(md->md_magic, data, 16);
269 	le32enc(data + 16, md->md_version);
270 	bcopy(md->md_name, data + 20, 16);
271 	le32enc(data + 36, md->md_mid);
272 	le32enc(data + 40, md->md_did);
273 	*(data + 44) = md->md_all;
274 	le32enc(data + 45, md->md_genid);
275 	le32enc(data + 49, md->md_syncid);
276 	*(data + 53) = md->md_priority;
277 	le32enc(data + 54, md->md_slice);
278 	*(data + 58) = md->md_balance;
279 	le64enc(data + 59, md->md_mediasize);
280 	le32enc(data + 67, md->md_sectorsize);
281 	le64enc(data + 71, md->md_sync_offset);
282 	le64enc(data + 79, md->md_mflags);
283 	le64enc(data + 87, md->md_dflags);
284 	bcopy(md->md_provider, data + 95, 16);
285 	le64enc(data + 111, md->md_provsize);
286 	MD5Init(&ctx);
287 	MD5Update(&ctx, data, 119);
288 	MD5Final(md->md_hash, &ctx);
289 	bcopy(md->md_hash, data + 119, 16);
290 }
291 static __inline int
292 mirror_metadata_decode_v0v1(const u_char *data, struct g_mirror_metadata *md)
293 {
294 	MD5_CTX ctx;
295 
296 	bcopy(data + 20, md->md_name, 16);
297 	md->md_mid = le32dec(data + 36);
298 	md->md_did = le32dec(data + 40);
299 	md->md_all = *(data + 44);
300 	md->md_syncid = le32dec(data + 45);
301 	md->md_priority = *(data + 49);
302 	md->md_slice = le32dec(data + 50);
303 	md->md_balance = *(data + 54);
304 	md->md_mediasize = le64dec(data + 55);
305 	md->md_sectorsize = le32dec(data + 63);
306 	md->md_sync_offset = le64dec(data + 67);
307 	md->md_mflags = le64dec(data + 75);
308 	md->md_dflags = le64dec(data + 83);
309 	bcopy(data + 91, md->md_provider, 16);
310 	bcopy(data + 107, md->md_hash, 16);
311 	MD5Init(&ctx);
312 	MD5Update(&ctx, data, 107);
313 	MD5Final(md->md_hash, &ctx);
314 	if (bcmp(md->md_hash, data + 107, 16) != 0)
315 		return (EINVAL);
316 
317 	/* New fields. */
318 	md->md_genid = 0;
319 	md->md_provsize = 0;
320 
321 	return (0);
322 }
323 static __inline int
324 mirror_metadata_decode_v2(const u_char *data, struct g_mirror_metadata *md)
325 {
326 	MD5_CTX ctx;
327 
328 	bcopy(data + 20, md->md_name, 16);
329 	md->md_mid = le32dec(data + 36);
330 	md->md_did = le32dec(data + 40);
331 	md->md_all = *(data + 44);
332 	md->md_genid = le32dec(data + 45);
333 	md->md_syncid = le32dec(data + 49);
334 	md->md_priority = *(data + 53);
335 	md->md_slice = le32dec(data + 54);
336 	md->md_balance = *(data + 58);
337 	md->md_mediasize = le64dec(data + 59);
338 	md->md_sectorsize = le32dec(data + 67);
339 	md->md_sync_offset = le64dec(data + 71);
340 	md->md_mflags = le64dec(data + 79);
341 	md->md_dflags = le64dec(data + 87);
342 	bcopy(data + 95, md->md_provider, 16);
343 	bcopy(data + 111, md->md_hash, 16);
344 	MD5Init(&ctx);
345 	MD5Update(&ctx, data, 111);
346 	MD5Final(md->md_hash, &ctx);
347 	if (bcmp(md->md_hash, data + 111, 16) != 0)
348 		return (EINVAL);
349 
350 	/* New fields. */
351 	md->md_provsize = 0;
352 
353 	return (0);
354 }
355 static __inline int
356 mirror_metadata_decode_v3v4(const u_char *data, struct g_mirror_metadata *md)
357 {
358 	MD5_CTX ctx;
359 
360 	bcopy(data + 20, md->md_name, 16);
361 	md->md_mid = le32dec(data + 36);
362 	md->md_did = le32dec(data + 40);
363 	md->md_all = *(data + 44);
364 	md->md_genid = le32dec(data + 45);
365 	md->md_syncid = le32dec(data + 49);
366 	md->md_priority = *(data + 53);
367 	md->md_slice = le32dec(data + 54);
368 	md->md_balance = *(data + 58);
369 	md->md_mediasize = le64dec(data + 59);
370 	md->md_sectorsize = le32dec(data + 67);
371 	md->md_sync_offset = le64dec(data + 71);
372 	md->md_mflags = le64dec(data + 79);
373 	md->md_dflags = le64dec(data + 87);
374 	bcopy(data + 95, md->md_provider, 16);
375 	md->md_provsize = le64dec(data + 111);
376 	bcopy(data + 119, md->md_hash, 16);
377 	MD5Init(&ctx);
378 	MD5Update(&ctx, data, 119);
379 	MD5Final(md->md_hash, &ctx);
380 	if (bcmp(md->md_hash, data + 119, 16) != 0)
381 		return (EINVAL);
382 	return (0);
383 }
384 static __inline int
385 mirror_metadata_decode(const u_char *data, struct g_mirror_metadata *md)
386 {
387 	int error;
388 
389 	bcopy(data, md->md_magic, 16);
390 	md->md_version = le32dec(data + 16);
391 	switch (md->md_version) {
392 	case 0:
393 	case 1:
394 		error = mirror_metadata_decode_v0v1(data, md);
395 		break;
396 	case 2:
397 		error = mirror_metadata_decode_v2(data, md);
398 		break;
399 	case 3:
400 	case 4:
401 		error = mirror_metadata_decode_v3v4(data, md);
402 		break;
403 	default:
404 		error = EINVAL;
405 		break;
406 	}
407 	return (error);
408 }
409 
410 static __inline const char *
411 balance_name(u_int balance)
412 {
413 	static const char *algorithms[] = {
414 		[G_MIRROR_BALANCE_NONE] = "none",
415 		[G_MIRROR_BALANCE_ROUND_ROBIN] = "round-robin",
416 		[G_MIRROR_BALANCE_LOAD] = "load",
417 		[G_MIRROR_BALANCE_SPLIT] = "split",
418 		[G_MIRROR_BALANCE_PREFER] = "prefer",
419 		[G_MIRROR_BALANCE_MAX + 1] = "unknown"
420 	};
421 
422 	if (balance > G_MIRROR_BALANCE_MAX)
423 		balance = G_MIRROR_BALANCE_MAX + 1;
424 
425 	return (algorithms[balance]);
426 }
427 
428 static __inline int
429 balance_id(const char *name)
430 {
431 	static const char *algorithms[] = {
432 		[G_MIRROR_BALANCE_NONE] = "none",
433 		[G_MIRROR_BALANCE_ROUND_ROBIN] = "round-robin",
434 		[G_MIRROR_BALANCE_LOAD] = "load",
435 		[G_MIRROR_BALANCE_SPLIT] = "split",
436 		[G_MIRROR_BALANCE_PREFER] = "prefer"
437 	};
438 	int n;
439 
440 	for (n = G_MIRROR_BALANCE_MIN; n <= G_MIRROR_BALANCE_MAX; n++) {
441 		if (strcmp(name, algorithms[n]) == 0)
442 			return (n);
443 	}
444 	return (-1);
445 }
446 
447 static __inline void
448 mirror_metadata_dump(const struct g_mirror_metadata *md)
449 {
450 	static const char hex[] = "0123456789abcdef";
451 	char hash[16 * 2 + 1];
452 	u_int i;
453 
454 	printf("     magic: %s\n", md->md_magic);
455 	printf("   version: %u\n", (u_int)md->md_version);
456 	printf("      name: %s\n", md->md_name);
457 	printf("       mid: %u\n", (u_int)md->md_mid);
458 	printf("       did: %u\n", (u_int)md->md_did);
459 	printf("       all: %u\n", (u_int)md->md_all);
460 	printf("     genid: %u\n", (u_int)md->md_genid);
461 	printf("    syncid: %u\n", (u_int)md->md_syncid);
462 	printf("  priority: %u\n", (u_int)md->md_priority);
463 	printf("     slice: %u\n", (u_int)md->md_slice);
464 	printf("   balance: %s\n", balance_name((u_int)md->md_balance));
465 	printf(" mediasize: %jd\n", (intmax_t)md->md_mediasize);
466 	printf("sectorsize: %u\n", (u_int)md->md_sectorsize);
467 	printf("syncoffset: %jd\n", (intmax_t)md->md_sync_offset);
468 	printf("    mflags:");
469 	if (md->md_mflags == 0)
470 		printf(" NONE");
471 	else {
472 		if ((md->md_mflags & G_MIRROR_DEVICE_FLAG_NOFAILSYNC) != 0)
473 			printf(" NOFAILSYNC");
474 		if ((md->md_mflags & G_MIRROR_DEVICE_FLAG_NOAUTOSYNC) != 0)
475 			printf(" NOAUTOSYNC");
476 	}
477 	printf("\n");
478 	printf("    dflags:");
479 	if (md->md_dflags == 0)
480 		printf(" NONE");
481 	else {
482 		if ((md->md_dflags & G_MIRROR_DISK_FLAG_DIRTY) != 0)
483 			printf(" DIRTY");
484 		if ((md->md_dflags & G_MIRROR_DISK_FLAG_SYNCHRONIZING) != 0)
485 			printf(" SYNCHRONIZING");
486 		if ((md->md_dflags & G_MIRROR_DISK_FLAG_FORCE_SYNC) != 0)
487 			printf(" FORCE_SYNC");
488 		if ((md->md_dflags & G_MIRROR_DISK_FLAG_INACTIVE) != 0)
489 			printf(" INACTIVE");
490 	}
491 	printf("\n");
492 	printf("hcprovider: %s\n", md->md_provider);
493 	printf("  provsize: %ju\n", (uintmax_t)md->md_provsize);
494 	bzero(hash, sizeof(hash));
495 	for (i = 0; i < 16; i++) {
496 		hash[i * 2] = hex[md->md_hash[i] >> 4];
497 		hash[i * 2 + 1] = hex[md->md_hash[i] & 0x0f];
498 	}
499 	printf("  MD5 hash: %s\n", hash);
500 }
501 #endif	/* !_G_MIRROR_H_ */
502