xref: /freebsd/sys/geom/mirror/g_mirror.h (revision bdd1243d)
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  * $FreeBSD$
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 	uint16_t	 d_rotation_rate;/* Disk's rotation rate */
143 	uint64_t	 d_init_mediasize;/* Initial mediasize */
144 };
145 #define	d_name	d_consumer->provider->name
146 
147 #define	G_MIRROR_EVENT_DONTWAIT	0x1
148 #define	G_MIRROR_EVENT_WAIT	0x2
149 #define	G_MIRROR_EVENT_DEVICE	0x4
150 #define	G_MIRROR_EVENT_DONE	0x8
151 struct g_mirror_event {
152 	struct g_mirror_disk	*e_disk;
153 	int			 e_state;
154 	int			 e_flags;
155 	int			 e_error;
156 	TAILQ_ENTRY(g_mirror_event) e_next;
157 };
158 
159 #define	G_MIRROR_DEVICE_STATE_STARTING		0
160 #define	G_MIRROR_DEVICE_STATE_RUNNING		1
161 
162 #define	G_MIRROR_TYPE_MANUAL	0
163 #define	G_MIRROR_TYPE_AUTOMATIC	1
164 
165 /* Bump syncid on first write. */
166 #define	G_MIRROR_BUMP_SYNCID		0x1
167 /* Bump genid immediately. */
168 #define	G_MIRROR_BUMP_GENID		0x2
169 /* Bump syncid immediately. */
170 #define	G_MIRROR_BUMP_SYNCID_NOW	0x4
171 struct g_mirror_softc {
172 	u_int		sc_type;	/* Device type (manual/automatic). */
173 	u_int		sc_state;	/* Device state. */
174 	uint32_t	sc_slice;	/* Slice size. */
175 	uint8_t		sc_balance;	/* Balance algorithm. */
176 	uint64_t	sc_mediasize;	/* Device size. */
177 	uint32_t	sc_sectorsize;	/* Sector size. */
178 	uint64_t	sc_flags;	/* Additional flags. */
179 
180 	struct g_geom	*sc_geom;
181 	struct g_provider *sc_provider;
182 	int		sc_provider_open;
183 
184 	uint32_t	sc_id;		/* Mirror unique ID. */
185 
186 	struct sx	 sc_lock;
187 	struct bio_queue sc_queue;
188 	struct mtx	 sc_queue_mtx;
189 	struct proc	*sc_worker;
190 	struct bio_queue sc_inflight; /* In-flight regular write requests. */
191 	struct bio_queue sc_regular_delayed; /* Delayed I/O requests due to
192 						collision with sync requests. */
193 	struct bio_queue sc_sync_delayed; /* Delayed sync requests due to
194 					     collision with regular requests. */
195 
196 	LIST_HEAD(, g_mirror_disk) sc_disks;
197 	u_int		sc_ndisks;	/* Number of disks. */
198 	struct g_mirror_disk *sc_hint;
199 
200 	u_int		sc_genid;	/* Generation ID. */
201 	u_int		sc_syncid;	/* Synchronization ID. */
202 	int		sc_bump_id;
203 	struct g_mirror_device_sync sc_sync;
204 	int		sc_idle;	/* DIRTY flags removed. */
205 	time_t		sc_last_write;
206 	u_int		sc_writes;
207 	u_int		sc_refcnt;	/* Number of softc references */
208 
209 	TAILQ_HEAD(, g_mirror_event) sc_events;
210 	struct mtx	sc_events_mtx;
211 	struct g_mirror_event *sc_timeout_event;
212 
213 	struct callout	sc_callout;
214 
215 	struct root_hold_token *sc_rootmount;
216 
217 	struct mtx	 sc_done_mtx;
218 };
219 #define	sc_name	sc_geom->name
220 
221 struct g_mirror_metadata;
222 
223 u_int g_mirror_ndisks(struct g_mirror_softc *sc, int state);
224 struct g_geom * g_mirror_create(struct g_class *mp,
225     const struct g_mirror_metadata *md, u_int type);
226 #define	G_MIRROR_DESTROY_SOFT		0
227 #define	G_MIRROR_DESTROY_DELAYED	1
228 #define	G_MIRROR_DESTROY_HARD		2
229 int g_mirror_destroy(struct g_mirror_softc *sc, int how);
230 int g_mirror_event_send(void *arg, int state, int flags);
231 struct g_mirror_metadata;
232 int g_mirror_add_disk(struct g_mirror_softc *sc, struct g_provider *pp,
233     struct g_mirror_metadata *md);
234 int g_mirror_read_metadata(struct g_consumer *cp, struct g_mirror_metadata *md);
235 void g_mirror_fill_metadata(struct g_mirror_softc *sc,
236     struct g_mirror_disk *disk, struct g_mirror_metadata *md);
237 void g_mirror_update_metadata(struct g_mirror_disk *disk);
238 
239 g_ctl_req_t g_mirror_config;
240 #endif	/* _KERNEL */
241 
242 struct g_mirror_metadata {
243 	char		md_magic[16];	/* Magic value. */
244 	uint32_t	md_version;	/* Version number. */
245 	char		md_name[16];	/* Mirror name. */
246 	uint32_t	md_mid;		/* Mirror unique ID. */
247 	uint32_t	md_did;		/* Disk unique ID. */
248 	uint8_t		md_all;		/* Number of disks in mirror. */
249 	uint32_t	md_genid;	/* Generation ID. */
250 	uint32_t	md_syncid;	/* Synchronization ID. */
251 	uint8_t		md_priority;	/* Disk priority. */
252 	uint32_t	md_slice;	/* Slice size. */
253 	uint8_t		md_balance;	/* Balance type. */
254 	uint64_t	md_mediasize;	/* Size of the smallest
255 					   disk in mirror. */
256 	uint32_t	md_sectorsize;	/* Sector size. */
257 	uint64_t	md_sync_offset;	/* Synchronized offset. */
258 	uint64_t	md_mflags;	/* Additional mirror flags. */
259 	uint64_t	md_dflags;	/* Additional disk flags. */
260 	char		md_provider[16]; /* Hardcoded provider. */
261 	uint64_t	md_provsize;	/* Provider's size. */
262 	u_char		md_hash[16];	/* MD5 hash. */
263 };
264 static __inline void
265 mirror_metadata_encode(struct g_mirror_metadata *md, u_char *data)
266 {
267 	MD5_CTX ctx;
268 
269 	bcopy(md->md_magic, data, 16);
270 	le32enc(data + 16, md->md_version);
271 	bcopy(md->md_name, data + 20, 16);
272 	le32enc(data + 36, md->md_mid);
273 	le32enc(data + 40, md->md_did);
274 	*(data + 44) = md->md_all;
275 	le32enc(data + 45, md->md_genid);
276 	le32enc(data + 49, md->md_syncid);
277 	*(data + 53) = md->md_priority;
278 	le32enc(data + 54, md->md_slice);
279 	*(data + 58) = md->md_balance;
280 	le64enc(data + 59, md->md_mediasize);
281 	le32enc(data + 67, md->md_sectorsize);
282 	le64enc(data + 71, md->md_sync_offset);
283 	le64enc(data + 79, md->md_mflags);
284 	le64enc(data + 87, md->md_dflags);
285 	bcopy(md->md_provider, data + 95, 16);
286 	le64enc(data + 111, md->md_provsize);
287 	MD5Init(&ctx);
288 	MD5Update(&ctx, data, 119);
289 	MD5Final(md->md_hash, &ctx);
290 	bcopy(md->md_hash, data + 119, 16);
291 }
292 static __inline int
293 mirror_metadata_decode_v0v1(const u_char *data, struct g_mirror_metadata *md)
294 {
295 	MD5_CTX ctx;
296 
297 	bcopy(data + 20, md->md_name, 16);
298 	md->md_mid = le32dec(data + 36);
299 	md->md_did = le32dec(data + 40);
300 	md->md_all = *(data + 44);
301 	md->md_syncid = le32dec(data + 45);
302 	md->md_priority = *(data + 49);
303 	md->md_slice = le32dec(data + 50);
304 	md->md_balance = *(data + 54);
305 	md->md_mediasize = le64dec(data + 55);
306 	md->md_sectorsize = le32dec(data + 63);
307 	md->md_sync_offset = le64dec(data + 67);
308 	md->md_mflags = le64dec(data + 75);
309 	md->md_dflags = le64dec(data + 83);
310 	bcopy(data + 91, md->md_provider, 16);
311 	bcopy(data + 107, md->md_hash, 16);
312 	MD5Init(&ctx);
313 	MD5Update(&ctx, data, 107);
314 	MD5Final(md->md_hash, &ctx);
315 	if (bcmp(md->md_hash, data + 107, 16) != 0)
316 		return (EINVAL);
317 
318 	/* New fields. */
319 	md->md_genid = 0;
320 	md->md_provsize = 0;
321 
322 	return (0);
323 }
324 static __inline int
325 mirror_metadata_decode_v2(const u_char *data, struct g_mirror_metadata *md)
326 {
327 	MD5_CTX ctx;
328 
329 	bcopy(data + 20, md->md_name, 16);
330 	md->md_mid = le32dec(data + 36);
331 	md->md_did = le32dec(data + 40);
332 	md->md_all = *(data + 44);
333 	md->md_genid = le32dec(data + 45);
334 	md->md_syncid = le32dec(data + 49);
335 	md->md_priority = *(data + 53);
336 	md->md_slice = le32dec(data + 54);
337 	md->md_balance = *(data + 58);
338 	md->md_mediasize = le64dec(data + 59);
339 	md->md_sectorsize = le32dec(data + 67);
340 	md->md_sync_offset = le64dec(data + 71);
341 	md->md_mflags = le64dec(data + 79);
342 	md->md_dflags = le64dec(data + 87);
343 	bcopy(data + 95, md->md_provider, 16);
344 	bcopy(data + 111, md->md_hash, 16);
345 	MD5Init(&ctx);
346 	MD5Update(&ctx, data, 111);
347 	MD5Final(md->md_hash, &ctx);
348 	if (bcmp(md->md_hash, data + 111, 16) != 0)
349 		return (EINVAL);
350 
351 	/* New fields. */
352 	md->md_provsize = 0;
353 
354 	return (0);
355 }
356 static __inline int
357 mirror_metadata_decode_v3v4(const u_char *data, struct g_mirror_metadata *md)
358 {
359 	MD5_CTX ctx;
360 
361 	bcopy(data + 20, md->md_name, 16);
362 	md->md_mid = le32dec(data + 36);
363 	md->md_did = le32dec(data + 40);
364 	md->md_all = *(data + 44);
365 	md->md_genid = le32dec(data + 45);
366 	md->md_syncid = le32dec(data + 49);
367 	md->md_priority = *(data + 53);
368 	md->md_slice = le32dec(data + 54);
369 	md->md_balance = *(data + 58);
370 	md->md_mediasize = le64dec(data + 59);
371 	md->md_sectorsize = le32dec(data + 67);
372 	md->md_sync_offset = le64dec(data + 71);
373 	md->md_mflags = le64dec(data + 79);
374 	md->md_dflags = le64dec(data + 87);
375 	bcopy(data + 95, md->md_provider, 16);
376 	md->md_provsize = le64dec(data + 111);
377 	bcopy(data + 119, md->md_hash, 16);
378 	MD5Init(&ctx);
379 	MD5Update(&ctx, data, 119);
380 	MD5Final(md->md_hash, &ctx);
381 	if (bcmp(md->md_hash, data + 119, 16) != 0)
382 		return (EINVAL);
383 	return (0);
384 }
385 static __inline int
386 mirror_metadata_decode(const u_char *data, struct g_mirror_metadata *md)
387 {
388 	int error;
389 
390 	bcopy(data, md->md_magic, 16);
391 	md->md_version = le32dec(data + 16);
392 	switch (md->md_version) {
393 	case 0:
394 	case 1:
395 		error = mirror_metadata_decode_v0v1(data, md);
396 		break;
397 	case 2:
398 		error = mirror_metadata_decode_v2(data, md);
399 		break;
400 	case 3:
401 	case 4:
402 		error = mirror_metadata_decode_v3v4(data, md);
403 		break;
404 	default:
405 		error = EINVAL;
406 		break;
407 	}
408 	return (error);
409 }
410 
411 static __inline const char *
412 balance_name(u_int balance)
413 {
414 	static const char *algorithms[] = {
415 		[G_MIRROR_BALANCE_NONE] = "none",
416 		[G_MIRROR_BALANCE_ROUND_ROBIN] = "round-robin",
417 		[G_MIRROR_BALANCE_LOAD] = "load",
418 		[G_MIRROR_BALANCE_SPLIT] = "split",
419 		[G_MIRROR_BALANCE_PREFER] = "prefer",
420 		[G_MIRROR_BALANCE_MAX + 1] = "unknown"
421 	};
422 
423 	if (balance > G_MIRROR_BALANCE_MAX)
424 		balance = G_MIRROR_BALANCE_MAX + 1;
425 
426 	return (algorithms[balance]);
427 }
428 
429 static __inline int
430 balance_id(const char *name)
431 {
432 	static const char *algorithms[] = {
433 		[G_MIRROR_BALANCE_NONE] = "none",
434 		[G_MIRROR_BALANCE_ROUND_ROBIN] = "round-robin",
435 		[G_MIRROR_BALANCE_LOAD] = "load",
436 		[G_MIRROR_BALANCE_SPLIT] = "split",
437 		[G_MIRROR_BALANCE_PREFER] = "prefer"
438 	};
439 	int n;
440 
441 	for (n = G_MIRROR_BALANCE_MIN; n <= G_MIRROR_BALANCE_MAX; n++) {
442 		if (strcmp(name, algorithms[n]) == 0)
443 			return (n);
444 	}
445 	return (-1);
446 }
447 
448 static __inline void
449 mirror_metadata_dump(const struct g_mirror_metadata *md)
450 {
451 	static const char hex[] = "0123456789abcdef";
452 	char hash[16 * 2 + 1];
453 	u_int i;
454 
455 	printf("     magic: %s\n", md->md_magic);
456 	printf("   version: %u\n", (u_int)md->md_version);
457 	printf("      name: %s\n", md->md_name);
458 	printf("       mid: %u\n", (u_int)md->md_mid);
459 	printf("       did: %u\n", (u_int)md->md_did);
460 	printf("       all: %u\n", (u_int)md->md_all);
461 	printf("     genid: %u\n", (u_int)md->md_genid);
462 	printf("    syncid: %u\n", (u_int)md->md_syncid);
463 	printf("  priority: %u\n", (u_int)md->md_priority);
464 	printf("     slice: %u\n", (u_int)md->md_slice);
465 	printf("   balance: %s\n", balance_name((u_int)md->md_balance));
466 	printf(" mediasize: %jd\n", (intmax_t)md->md_mediasize);
467 	printf("sectorsize: %u\n", (u_int)md->md_sectorsize);
468 	printf("syncoffset: %jd\n", (intmax_t)md->md_sync_offset);
469 	printf("    mflags:");
470 	if (md->md_mflags == 0)
471 		printf(" NONE");
472 	else {
473 		if ((md->md_mflags & G_MIRROR_DEVICE_FLAG_NOFAILSYNC) != 0)
474 			printf(" NOFAILSYNC");
475 		if ((md->md_mflags & G_MIRROR_DEVICE_FLAG_NOAUTOSYNC) != 0)
476 			printf(" NOAUTOSYNC");
477 	}
478 	printf("\n");
479 	printf("    dflags:");
480 	if (md->md_dflags == 0)
481 		printf(" NONE");
482 	else {
483 		if ((md->md_dflags & G_MIRROR_DISK_FLAG_DIRTY) != 0)
484 			printf(" DIRTY");
485 		if ((md->md_dflags & G_MIRROR_DISK_FLAG_SYNCHRONIZING) != 0)
486 			printf(" SYNCHRONIZING");
487 		if ((md->md_dflags & G_MIRROR_DISK_FLAG_FORCE_SYNC) != 0)
488 			printf(" FORCE_SYNC");
489 		if ((md->md_dflags & G_MIRROR_DISK_FLAG_INACTIVE) != 0)
490 			printf(" INACTIVE");
491 	}
492 	printf("\n");
493 	printf("hcprovider: %s\n", md->md_provider);
494 	printf("  provsize: %ju\n", (uintmax_t)md->md_provsize);
495 	bzero(hash, sizeof(hash));
496 	for (i = 0; i < 16; i++) {
497 		hash[i * 2] = hex[md->md_hash[i] >> 4];
498 		hash[i * 2 + 1] = hex[md->md_hash[i] & 0x0f];
499 	}
500 	printf("  MD5 hash: %s\n", hash);
501 }
502 #endif	/* !_G_MIRROR_H_ */
503