xref: /titanic_41/usr/src/uts/common/fs/zfs/zap_leaf.c (revision fa07eb87a1d9d2451a6b00545db4e1d2fba944b4)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 /*
27  * The 512-byte leaf is broken into 32 16-byte chunks.
28  * chunk number n means l_chunk[n], even though the header precedes it.
29  * the names are stored null-terminated.
30  */
31 
32 #include <sys/spa.h>
33 #include <sys/dmu.h>
34 #include <sys/zfs_context.h>
35 #include <sys/fs/zfs.h>
36 #include <sys/zap.h>
37 #include <sys/zap_impl.h>
38 #include <sys/zap_leaf.h>
39 
40 static uint16_t *zap_leaf_rehash_entry(zap_leaf_t *l, uint16_t entry);
41 
42 #define	CHAIN_END 0xffff /* end of the chunk chain */
43 
44 /* half the (current) minimum block size */
45 #define	MAX_ARRAY_BYTES (8<<10)
46 
47 #define	LEAF_HASH(l, h) \
48 	((ZAP_LEAF_HASH_NUMENTRIES(l)-1) & \
49 	((h) >> (64 - ZAP_LEAF_HASH_SHIFT(l)-(l)->l_phys->l_hdr.lh_prefix_len)))
50 
51 #define	LEAF_HASH_ENTPTR(l, h) (&(l)->l_phys->l_hash[LEAF_HASH(l, h)])
52 
53 
54 static void
55 zap_memset(void *a, int c, size_t n)
56 {
57 	char *cp = a;
58 	char *cpend = cp + n;
59 
60 	while (cp < cpend)
61 		*cp++ = c;
62 }
63 
64 static void
65 stv(int len, void *addr, uint64_t value)
66 {
67 	switch (len) {
68 	case 1:
69 		*(uint8_t *)addr = value;
70 		return;
71 	case 2:
72 		*(uint16_t *)addr = value;
73 		return;
74 	case 4:
75 		*(uint32_t *)addr = value;
76 		return;
77 	case 8:
78 		*(uint64_t *)addr = value;
79 		return;
80 	}
81 	ASSERT(!"bad int len");
82 }
83 
84 static uint64_t
85 ldv(int len, const void *addr)
86 {
87 	switch (len) {
88 	case 1:
89 		return (*(uint8_t *)addr);
90 	case 2:
91 		return (*(uint16_t *)addr);
92 	case 4:
93 		return (*(uint32_t *)addr);
94 	case 8:
95 		return (*(uint64_t *)addr);
96 	}
97 	ASSERT(!"bad int len");
98 	return (0xFEEDFACEDEADBEEFULL);
99 }
100 
101 void
102 zap_leaf_byteswap(zap_leaf_phys_t *buf, int size)
103 {
104 	int i;
105 	zap_leaf_t l;
106 	l.l_bs = highbit(size)-1;
107 	l.l_phys = buf;
108 
109 	buf->l_hdr.lh_block_type = 	BSWAP_64(buf->l_hdr.lh_block_type);
110 	buf->l_hdr.lh_prefix = 		BSWAP_64(buf->l_hdr.lh_prefix);
111 	buf->l_hdr.lh_magic = 		BSWAP_32(buf->l_hdr.lh_magic);
112 	buf->l_hdr.lh_nfree = 		BSWAP_16(buf->l_hdr.lh_nfree);
113 	buf->l_hdr.lh_nentries = 	BSWAP_16(buf->l_hdr.lh_nentries);
114 	buf->l_hdr.lh_prefix_len = 	BSWAP_16(buf->l_hdr.lh_prefix_len);
115 	buf->l_hdr.lh_freelist = 	BSWAP_16(buf->l_hdr.lh_freelist);
116 
117 	for (i = 0; i < ZAP_LEAF_HASH_NUMENTRIES(&l); i++)
118 		buf->l_hash[i] = BSWAP_16(buf->l_hash[i]);
119 
120 	for (i = 0; i < ZAP_LEAF_NUMCHUNKS(&l); i++) {
121 		zap_leaf_chunk_t *lc = &ZAP_LEAF_CHUNK(&l, i);
122 		struct zap_leaf_entry *le;
123 
124 		switch (lc->l_free.lf_type) {
125 		case ZAP_CHUNK_ENTRY:
126 			le = &lc->l_entry;
127 
128 			le->le_type =		BSWAP_8(le->le_type);
129 			le->le_int_size =	BSWAP_8(le->le_int_size);
130 			le->le_next =		BSWAP_16(le->le_next);
131 			le->le_name_chunk =	BSWAP_16(le->le_name_chunk);
132 			le->le_name_length =	BSWAP_16(le->le_name_length);
133 			le->le_value_chunk =	BSWAP_16(le->le_value_chunk);
134 			le->le_value_length =	BSWAP_16(le->le_value_length);
135 			le->le_cd =		BSWAP_32(le->le_cd);
136 			le->le_hash =		BSWAP_64(le->le_hash);
137 			break;
138 		case ZAP_CHUNK_FREE:
139 			lc->l_free.lf_type =	BSWAP_8(lc->l_free.lf_type);
140 			lc->l_free.lf_next =	BSWAP_16(lc->l_free.lf_next);
141 			break;
142 		case ZAP_CHUNK_ARRAY:
143 			lc->l_array.la_type =	BSWAP_8(lc->l_array.la_type);
144 			lc->l_array.la_next =	BSWAP_16(lc->l_array.la_next);
145 			/* la_array doesn't need swapping */
146 			break;
147 		default:
148 			ASSERT(!"bad leaf type");
149 		}
150 	}
151 }
152 
153 void
154 zap_leaf_init(zap_leaf_t *l, boolean_t sort)
155 {
156 	int i;
157 
158 	l->l_bs = highbit(l->l_dbuf->db_size)-1;
159 	zap_memset(&l->l_phys->l_hdr, 0, sizeof (struct zap_leaf_header));
160 	zap_memset(l->l_phys->l_hash, CHAIN_END, 2*ZAP_LEAF_HASH_NUMENTRIES(l));
161 	for (i = 0; i < ZAP_LEAF_NUMCHUNKS(l); i++) {
162 		ZAP_LEAF_CHUNK(l, i).l_free.lf_type = ZAP_CHUNK_FREE;
163 		ZAP_LEAF_CHUNK(l, i).l_free.lf_next = i+1;
164 	}
165 	ZAP_LEAF_CHUNK(l, ZAP_LEAF_NUMCHUNKS(l)-1).l_free.lf_next = CHAIN_END;
166 	l->l_phys->l_hdr.lh_block_type = ZBT_LEAF;
167 	l->l_phys->l_hdr.lh_magic = ZAP_LEAF_MAGIC;
168 	l->l_phys->l_hdr.lh_nfree = ZAP_LEAF_NUMCHUNKS(l);
169 	if (sort)
170 		l->l_phys->l_hdr.lh_flags |= ZLF_ENTRIES_CDSORTED;
171 }
172 
173 /*
174  * Routines which manipulate leaf chunks (l_chunk[]).
175  */
176 
177 static uint16_t
178 zap_leaf_chunk_alloc(zap_leaf_t *l)
179 {
180 	int chunk;
181 
182 	ASSERT(l->l_phys->l_hdr.lh_nfree > 0);
183 
184 	chunk = l->l_phys->l_hdr.lh_freelist;
185 	ASSERT3U(chunk, <, ZAP_LEAF_NUMCHUNKS(l));
186 	ASSERT3U(ZAP_LEAF_CHUNK(l, chunk).l_free.lf_type, ==, ZAP_CHUNK_FREE);
187 
188 	l->l_phys->l_hdr.lh_freelist = ZAP_LEAF_CHUNK(l, chunk).l_free.lf_next;
189 
190 	l->l_phys->l_hdr.lh_nfree--;
191 
192 	return (chunk);
193 }
194 
195 static void
196 zap_leaf_chunk_free(zap_leaf_t *l, uint16_t chunk)
197 {
198 	struct zap_leaf_free *zlf = &ZAP_LEAF_CHUNK(l, chunk).l_free;
199 	ASSERT3U(l->l_phys->l_hdr.lh_nfree, <, ZAP_LEAF_NUMCHUNKS(l));
200 	ASSERT3U(chunk, <, ZAP_LEAF_NUMCHUNKS(l));
201 	ASSERT(zlf->lf_type != ZAP_CHUNK_FREE);
202 
203 	zlf->lf_type = ZAP_CHUNK_FREE;
204 	zlf->lf_next = l->l_phys->l_hdr.lh_freelist;
205 	bzero(zlf->lf_pad, sizeof (zlf->lf_pad)); /* help it to compress */
206 	l->l_phys->l_hdr.lh_freelist = chunk;
207 
208 	l->l_phys->l_hdr.lh_nfree++;
209 }
210 
211 /*
212  * Routines which manipulate leaf arrays (zap_leaf_array type chunks).
213  */
214 
215 static uint16_t
216 zap_leaf_array_create(zap_leaf_t *l, const char *buf,
217 	int integer_size, int num_integers)
218 {
219 	uint16_t chunk_head;
220 	uint16_t *chunkp = &chunk_head;
221 	int byten = 0;
222 	uint64_t value;
223 	int shift = (integer_size-1)*8;
224 	int len = num_integers;
225 
226 	ASSERT3U(num_integers * integer_size, <, MAX_ARRAY_BYTES);
227 
228 	while (len > 0) {
229 		uint16_t chunk = zap_leaf_chunk_alloc(l);
230 		struct zap_leaf_array *la = &ZAP_LEAF_CHUNK(l, chunk).l_array;
231 		int i;
232 
233 		la->la_type = ZAP_CHUNK_ARRAY;
234 		for (i = 0; i < ZAP_LEAF_ARRAY_BYTES; i++) {
235 			if (byten == 0)
236 				value = ldv(integer_size, buf);
237 			la->la_array[i] = value >> shift;
238 			value <<= 8;
239 			if (++byten == integer_size) {
240 				byten = 0;
241 				buf += integer_size;
242 				if (--len == 0)
243 					break;
244 			}
245 		}
246 
247 		*chunkp = chunk;
248 		chunkp = &la->la_next;
249 	}
250 	*chunkp = CHAIN_END;
251 
252 	return (chunk_head);
253 }
254 
255 static void
256 zap_leaf_array_free(zap_leaf_t *l, uint16_t *chunkp)
257 {
258 	uint16_t chunk = *chunkp;
259 
260 	*chunkp = CHAIN_END;
261 
262 	while (chunk != CHAIN_END) {
263 		int nextchunk = ZAP_LEAF_CHUNK(l, chunk).l_array.la_next;
264 		ASSERT3U(ZAP_LEAF_CHUNK(l, chunk).l_array.la_type, ==,
265 		    ZAP_CHUNK_ARRAY);
266 		zap_leaf_chunk_free(l, chunk);
267 		chunk = nextchunk;
268 	}
269 }
270 
271 /* array_len and buf_len are in integers, not bytes */
272 static void
273 zap_leaf_array_read(zap_leaf_t *l, uint16_t chunk,
274     int array_int_len, int array_len, int buf_int_len, uint64_t buf_len,
275     char *buf)
276 {
277 	int len = MIN(array_len, buf_len);
278 	int byten = 0;
279 	uint64_t value = 0;
280 
281 	ASSERT3U(array_int_len, <=, buf_int_len);
282 
283 	/* Fast path for one 8-byte integer */
284 	if (array_int_len == 8 && buf_int_len == 8 && len == 1) {
285 		struct zap_leaf_array *la = &ZAP_LEAF_CHUNK(l, chunk).l_array;
286 		uint8_t *ip = la->la_array;
287 		uint64_t *buf64 = (uint64_t *)buf;
288 
289 		*buf64 = (uint64_t)ip[0] << 56 | (uint64_t)ip[1] << 48 |
290 		    (uint64_t)ip[2] << 40 | (uint64_t)ip[3] << 32 |
291 		    (uint64_t)ip[4] << 24 | (uint64_t)ip[5] << 16 |
292 		    (uint64_t)ip[6] << 8 | (uint64_t)ip[7];
293 		return;
294 	}
295 
296 	/* Fast path for an array of 1-byte integers (eg. the entry name) */
297 	if (array_int_len == 1 && buf_int_len == 1 &&
298 	    buf_len > array_len + ZAP_LEAF_ARRAY_BYTES) {
299 		while (chunk != CHAIN_END) {
300 			struct zap_leaf_array *la =
301 			    &ZAP_LEAF_CHUNK(l, chunk).l_array;
302 			bcopy(la->la_array, buf, ZAP_LEAF_ARRAY_BYTES);
303 			buf += ZAP_LEAF_ARRAY_BYTES;
304 			chunk = la->la_next;
305 		}
306 		return;
307 	}
308 
309 	while (len > 0) {
310 		struct zap_leaf_array *la = &ZAP_LEAF_CHUNK(l, chunk).l_array;
311 		int i;
312 
313 		ASSERT3U(chunk, <, ZAP_LEAF_NUMCHUNKS(l));
314 		for (i = 0; i < ZAP_LEAF_ARRAY_BYTES && len > 0; i++) {
315 			value = (value << 8) | la->la_array[i];
316 			byten++;
317 			if (byten == array_int_len) {
318 				stv(buf_int_len, buf, value);
319 				byten = 0;
320 				len--;
321 				if (len == 0)
322 					return;
323 				buf += buf_int_len;
324 			}
325 		}
326 		chunk = la->la_next;
327 	}
328 }
329 
330 /*
331  * Only to be used on 8-bit arrays.
332  * array_len is actual len in bytes (not encoded le_value_length).
333  * namenorm is null-terminated.
334  */
335 static boolean_t
336 zap_leaf_array_match(zap_leaf_t *l, zap_name_t *zn, int chunk, int array_len)
337 {
338 	int bseen = 0;
339 
340 	if (zn->zn_matchtype == MT_FIRST) {
341 		char *thisname = kmem_alloc(array_len, KM_SLEEP);
342 		boolean_t match;
343 
344 		zap_leaf_array_read(l, chunk, 1, array_len, 1,
345 		    array_len, thisname);
346 		match = zap_match(zn, thisname);
347 		kmem_free(thisname, array_len);
348 		return (match);
349 	}
350 
351 	/* Fast path for exact matching */
352 	while (bseen < array_len) {
353 		struct zap_leaf_array *la = &ZAP_LEAF_CHUNK(l, chunk).l_array;
354 		int toread = MIN(array_len - bseen, ZAP_LEAF_ARRAY_BYTES);
355 		ASSERT3U(chunk, <, ZAP_LEAF_NUMCHUNKS(l));
356 		if (bcmp(la->la_array, zn->zn_name_orij + bseen, toread))
357 			break;
358 		chunk = la->la_next;
359 		bseen += toread;
360 	}
361 	return (bseen == array_len);
362 }
363 
364 /*
365  * Routines which manipulate leaf entries.
366  */
367 
368 int
369 zap_leaf_lookup(zap_leaf_t *l, zap_name_t *zn, zap_entry_handle_t *zeh)
370 {
371 	uint16_t *chunkp;
372 	struct zap_leaf_entry *le;
373 
374 	ASSERT3U(l->l_phys->l_hdr.lh_magic, ==, ZAP_LEAF_MAGIC);
375 
376 again:
377 	for (chunkp = LEAF_HASH_ENTPTR(l, zn->zn_hash);
378 	    *chunkp != CHAIN_END; chunkp = &le->le_next) {
379 		uint16_t chunk = *chunkp;
380 		le = ZAP_LEAF_ENTRY(l, chunk);
381 
382 		ASSERT3U(chunk, <, ZAP_LEAF_NUMCHUNKS(l));
383 		ASSERT3U(le->le_type, ==, ZAP_CHUNK_ENTRY);
384 
385 		if (le->le_hash != zn->zn_hash)
386 			continue;
387 
388 		/*
389 		 * NB: the entry chain is always sorted by cd on
390 		 * normalized zap objects, so this will find the
391 		 * lowest-cd match for MT_FIRST.
392 		 */
393 		ASSERT(zn->zn_matchtype == MT_EXACT ||
394 		    (l->l_phys->l_hdr.lh_flags & ZLF_ENTRIES_CDSORTED));
395 		if (zap_leaf_array_match(l, zn, le->le_name_chunk,
396 		    le->le_name_length)) {
397 			zeh->zeh_num_integers = le->le_value_length;
398 			zeh->zeh_integer_size = le->le_int_size;
399 			zeh->zeh_cd = le->le_cd;
400 			zeh->zeh_hash = le->le_hash;
401 			zeh->zeh_chunkp = chunkp;
402 			zeh->zeh_leaf = l;
403 			return (0);
404 		}
405 	}
406 
407 	/*
408 	 * NB: we could of course do this in one pass, but that would be
409 	 * a pain.  We'll see if MT_BEST is even used much.
410 	 */
411 	if (zn->zn_matchtype == MT_BEST) {
412 		zn->zn_matchtype = MT_FIRST;
413 		goto again;
414 	}
415 
416 	return (ENOENT);
417 }
418 
419 /* Return (h1,cd1 >= h2,cd2) */
420 #define	HCD_GTEQ(h1, cd1, h2, cd2) \
421 	((h1 > h2) ? TRUE : ((h1 == h2 && cd1 >= cd2) ? TRUE : FALSE))
422 
423 int
424 zap_leaf_lookup_closest(zap_leaf_t *l,
425     uint64_t h, uint32_t cd, zap_entry_handle_t *zeh)
426 {
427 	uint16_t chunk;
428 	uint64_t besth = -1ULL;
429 	uint32_t bestcd = ZAP_MAXCD;
430 	uint16_t bestlh = ZAP_LEAF_HASH_NUMENTRIES(l)-1;
431 	uint16_t lh;
432 	struct zap_leaf_entry *le;
433 
434 	ASSERT3U(l->l_phys->l_hdr.lh_magic, ==, ZAP_LEAF_MAGIC);
435 
436 	for (lh = LEAF_HASH(l, h); lh <= bestlh; lh++) {
437 		for (chunk = l->l_phys->l_hash[lh];
438 		    chunk != CHAIN_END; chunk = le->le_next) {
439 			le = ZAP_LEAF_ENTRY(l, chunk);
440 
441 			ASSERT3U(chunk, <, ZAP_LEAF_NUMCHUNKS(l));
442 			ASSERT3U(le->le_type, ==, ZAP_CHUNK_ENTRY);
443 
444 			if (HCD_GTEQ(le->le_hash, le->le_cd, h, cd) &&
445 			    HCD_GTEQ(besth, bestcd, le->le_hash, le->le_cd)) {
446 				ASSERT3U(bestlh, >=, lh);
447 				bestlh = lh;
448 				besth = le->le_hash;
449 				bestcd = le->le_cd;
450 
451 				zeh->zeh_num_integers = le->le_value_length;
452 				zeh->zeh_integer_size = le->le_int_size;
453 				zeh->zeh_cd = le->le_cd;
454 				zeh->zeh_hash = le->le_hash;
455 				zeh->zeh_fakechunk = chunk;
456 				zeh->zeh_chunkp = &zeh->zeh_fakechunk;
457 				zeh->zeh_leaf = l;
458 			}
459 		}
460 	}
461 
462 	return (bestcd == ZAP_MAXCD ? ENOENT : 0);
463 }
464 
465 int
466 zap_entry_read(const zap_entry_handle_t *zeh,
467     uint8_t integer_size, uint64_t num_integers, void *buf)
468 {
469 	struct zap_leaf_entry *le =
470 	    ZAP_LEAF_ENTRY(zeh->zeh_leaf, *zeh->zeh_chunkp);
471 	ASSERT3U(le->le_type, ==, ZAP_CHUNK_ENTRY);
472 
473 	if (le->le_int_size > integer_size)
474 		return (EINVAL);
475 
476 	zap_leaf_array_read(zeh->zeh_leaf, le->le_value_chunk, le->le_int_size,
477 	    le->le_value_length, integer_size, num_integers, buf);
478 
479 	if (zeh->zeh_num_integers > num_integers)
480 		return (EOVERFLOW);
481 	return (0);
482 
483 }
484 
485 int
486 zap_entry_read_name(const zap_entry_handle_t *zeh, uint16_t buflen, char *buf)
487 {
488 	struct zap_leaf_entry *le =
489 	    ZAP_LEAF_ENTRY(zeh->zeh_leaf, *zeh->zeh_chunkp);
490 	ASSERT3U(le->le_type, ==, ZAP_CHUNK_ENTRY);
491 
492 	zap_leaf_array_read(zeh->zeh_leaf, le->le_name_chunk, 1,
493 	    le->le_name_length, 1, buflen, buf);
494 	if (le->le_name_length > buflen)
495 		return (EOVERFLOW);
496 	return (0);
497 }
498 
499 int
500 zap_entry_update(zap_entry_handle_t *zeh,
501 	uint8_t integer_size, uint64_t num_integers, const void *buf)
502 {
503 	int delta_chunks;
504 	zap_leaf_t *l = zeh->zeh_leaf;
505 	struct zap_leaf_entry *le = ZAP_LEAF_ENTRY(l, *zeh->zeh_chunkp);
506 
507 	delta_chunks = ZAP_LEAF_ARRAY_NCHUNKS(num_integers * integer_size) -
508 	    ZAP_LEAF_ARRAY_NCHUNKS(le->le_value_length * le->le_int_size);
509 
510 	if ((int)l->l_phys->l_hdr.lh_nfree < delta_chunks)
511 		return (EAGAIN);
512 
513 	/*
514 	 * We should search other chained leaves (via
515 	 * zap_entry_remove,create?) otherwise returning EAGAIN will
516 	 * just send us into an infinite loop if we have to chain
517 	 * another leaf block, rather than being able to split this
518 	 * block.
519 	 */
520 
521 	zap_leaf_array_free(l, &le->le_value_chunk);
522 	le->le_value_chunk =
523 	    zap_leaf_array_create(l, buf, integer_size, num_integers);
524 	le->le_value_length = num_integers;
525 	le->le_int_size = integer_size;
526 	return (0);
527 }
528 
529 void
530 zap_entry_remove(zap_entry_handle_t *zeh)
531 {
532 	uint16_t entry_chunk;
533 	struct zap_leaf_entry *le;
534 	zap_leaf_t *l = zeh->zeh_leaf;
535 
536 	ASSERT3P(zeh->zeh_chunkp, !=, &zeh->zeh_fakechunk);
537 
538 	entry_chunk = *zeh->zeh_chunkp;
539 	le = ZAP_LEAF_ENTRY(l, entry_chunk);
540 	ASSERT3U(le->le_type, ==, ZAP_CHUNK_ENTRY);
541 
542 	zap_leaf_array_free(l, &le->le_name_chunk);
543 	zap_leaf_array_free(l, &le->le_value_chunk);
544 
545 	*zeh->zeh_chunkp = le->le_next;
546 	zap_leaf_chunk_free(l, entry_chunk);
547 
548 	l->l_phys->l_hdr.lh_nentries--;
549 }
550 
551 int
552 zap_entry_create(zap_leaf_t *l, const char *name, uint64_t h, uint32_t cd,
553     uint8_t integer_size, uint64_t num_integers, const void *buf,
554     zap_entry_handle_t *zeh)
555 {
556 	uint16_t chunk;
557 	uint16_t *chunkp;
558 	struct zap_leaf_entry *le;
559 	uint64_t namelen, valuelen;
560 	int numchunks;
561 
562 	valuelen = integer_size * num_integers;
563 	namelen = strlen(name) + 1;
564 	ASSERT(namelen >= 2);
565 
566 	numchunks = 1 + ZAP_LEAF_ARRAY_NCHUNKS(namelen) +
567 	    ZAP_LEAF_ARRAY_NCHUNKS(valuelen);
568 	if (numchunks > ZAP_LEAF_NUMCHUNKS(l))
569 		return (E2BIG);
570 
571 	if (cd == ZAP_MAXCD) {
572 		/* find the lowest unused cd */
573 		if (l->l_phys->l_hdr.lh_flags & ZLF_ENTRIES_CDSORTED) {
574 			cd = 0;
575 
576 			for (chunk = *LEAF_HASH_ENTPTR(l, h);
577 			    chunk != CHAIN_END; chunk = le->le_next) {
578 				le = ZAP_LEAF_ENTRY(l, chunk);
579 				if (le->le_cd > cd)
580 					break;
581 				if (le->le_hash == h) {
582 					ASSERT3U(cd, ==, le->le_cd);
583 					cd++;
584 				}
585 			}
586 		} else {
587 			/* old unsorted format; do it the O(n^2) way */
588 			for (cd = 0; cd < ZAP_MAXCD; cd++) {
589 				for (chunk = *LEAF_HASH_ENTPTR(l, h);
590 				    chunk != CHAIN_END; chunk = le->le_next) {
591 					le = ZAP_LEAF_ENTRY(l, chunk);
592 					if (le->le_hash == h &&
593 					    le->le_cd == cd) {
594 						break;
595 					}
596 				}
597 				/* If this cd is not in use, we are good. */
598 				if (chunk == CHAIN_END)
599 					break;
600 			}
601 		}
602 		/*
603 		 * we would run out of space in a block before we could
604 		 * have ZAP_MAXCD entries
605 		 */
606 		ASSERT3U(cd, <, ZAP_MAXCD);
607 	}
608 
609 	if (l->l_phys->l_hdr.lh_nfree < numchunks)
610 		return (EAGAIN);
611 
612 	/* make the entry */
613 	chunk = zap_leaf_chunk_alloc(l);
614 	le = ZAP_LEAF_ENTRY(l, chunk);
615 	le->le_type = ZAP_CHUNK_ENTRY;
616 	le->le_name_chunk = zap_leaf_array_create(l, name, 1, namelen);
617 	le->le_name_length = namelen;
618 	le->le_value_chunk =
619 	    zap_leaf_array_create(l, buf, integer_size, num_integers);
620 	le->le_value_length = num_integers;
621 	le->le_int_size = integer_size;
622 	le->le_hash = h;
623 	le->le_cd = cd;
624 
625 	/* link it into the hash chain */
626 	/* XXX if we did the search above, we could just use that */
627 	chunkp = zap_leaf_rehash_entry(l, chunk);
628 
629 	l->l_phys->l_hdr.lh_nentries++;
630 
631 	zeh->zeh_leaf = l;
632 	zeh->zeh_num_integers = num_integers;
633 	zeh->zeh_integer_size = le->le_int_size;
634 	zeh->zeh_cd = le->le_cd;
635 	zeh->zeh_hash = le->le_hash;
636 	zeh->zeh_chunkp = chunkp;
637 
638 	return (0);
639 }
640 
641 /*
642  * Determine if there is another entry with the same normalized form.
643  * For performance purposes, either zn or name must be provided (the
644  * other can be NULL).  Note, there usually won't be any hash
645  * conflicts, in which case we don't need the concatenated/normalized
646  * form of the name.  But all callers have one of these on hand anyway,
647  * so might as well take advantage.  A cleaner but slower interface
648  * would accept neither argument, and compute the normalized name as
649  * needed (using zap_name_alloc(zap_entry_read_name(zeh))).
650  */
651 boolean_t
652 zap_entry_normalization_conflict(zap_entry_handle_t *zeh, zap_name_t *zn,
653     const char *name, zap_t *zap)
654 {
655 	uint64_t chunk;
656 	struct zap_leaf_entry *le;
657 	boolean_t allocdzn = B_FALSE;
658 
659 	if (zap->zap_normflags == 0)
660 		return (B_FALSE);
661 
662 	for (chunk = *LEAF_HASH_ENTPTR(zeh->zeh_leaf, zeh->zeh_hash);
663 	    chunk != CHAIN_END; chunk = le->le_next) {
664 		le = ZAP_LEAF_ENTRY(zeh->zeh_leaf, chunk);
665 		if (le->le_hash != zeh->zeh_hash)
666 			continue;
667 		if (le->le_cd == zeh->zeh_cd)
668 			continue;
669 
670 		if (zn == NULL) {
671 			zn = zap_name_alloc(zap, name, MT_FIRST);
672 			allocdzn = B_TRUE;
673 		}
674 		if (zap_leaf_array_match(zeh->zeh_leaf, zn,
675 		    le->le_name_chunk, le->le_name_length)) {
676 			if (allocdzn)
677 				zap_name_free(zn);
678 			return (B_TRUE);
679 		}
680 	}
681 	if (allocdzn)
682 		zap_name_free(zn);
683 	return (B_FALSE);
684 }
685 
686 /*
687  * Routines for transferring entries between leafs.
688  */
689 
690 static uint16_t *
691 zap_leaf_rehash_entry(zap_leaf_t *l, uint16_t entry)
692 {
693 	struct zap_leaf_entry *le = ZAP_LEAF_ENTRY(l, entry);
694 	struct zap_leaf_entry *le2;
695 	uint16_t *chunkp;
696 
697 	/*
698 	 * keep the entry chain sorted by cd
699 	 * NB: this will not cause problems for unsorted leafs, though
700 	 * it is unnecessary there.
701 	 */
702 	for (chunkp = LEAF_HASH_ENTPTR(l, le->le_hash);
703 	    *chunkp != CHAIN_END; chunkp = &le2->le_next) {
704 		le2 = ZAP_LEAF_ENTRY(l, *chunkp);
705 		if (le2->le_cd > le->le_cd)
706 			break;
707 	}
708 
709 	le->le_next = *chunkp;
710 	*chunkp = entry;
711 	return (chunkp);
712 }
713 
714 static uint16_t
715 zap_leaf_transfer_array(zap_leaf_t *l, uint16_t chunk, zap_leaf_t *nl)
716 {
717 	uint16_t new_chunk;
718 	uint16_t *nchunkp = &new_chunk;
719 
720 	while (chunk != CHAIN_END) {
721 		uint16_t nchunk = zap_leaf_chunk_alloc(nl);
722 		struct zap_leaf_array *nla =
723 		    &ZAP_LEAF_CHUNK(nl, nchunk).l_array;
724 		struct zap_leaf_array *la =
725 		    &ZAP_LEAF_CHUNK(l, chunk).l_array;
726 		int nextchunk = la->la_next;
727 
728 		ASSERT3U(chunk, <, ZAP_LEAF_NUMCHUNKS(l));
729 		ASSERT3U(nchunk, <, ZAP_LEAF_NUMCHUNKS(l));
730 
731 		*nla = *la; /* structure assignment */
732 
733 		zap_leaf_chunk_free(l, chunk);
734 		chunk = nextchunk;
735 		*nchunkp = nchunk;
736 		nchunkp = &nla->la_next;
737 	}
738 	*nchunkp = CHAIN_END;
739 	return (new_chunk);
740 }
741 
742 static void
743 zap_leaf_transfer_entry(zap_leaf_t *l, int entry, zap_leaf_t *nl)
744 {
745 	struct zap_leaf_entry *le, *nle;
746 	uint16_t chunk;
747 
748 	le = ZAP_LEAF_ENTRY(l, entry);
749 	ASSERT3U(le->le_type, ==, ZAP_CHUNK_ENTRY);
750 
751 	chunk = zap_leaf_chunk_alloc(nl);
752 	nle = ZAP_LEAF_ENTRY(nl, chunk);
753 	*nle = *le; /* structure assignment */
754 
755 	(void) zap_leaf_rehash_entry(nl, chunk);
756 
757 	nle->le_name_chunk = zap_leaf_transfer_array(l, le->le_name_chunk, nl);
758 	nle->le_value_chunk =
759 	    zap_leaf_transfer_array(l, le->le_value_chunk, nl);
760 
761 	zap_leaf_chunk_free(l, entry);
762 
763 	l->l_phys->l_hdr.lh_nentries--;
764 	nl->l_phys->l_hdr.lh_nentries++;
765 }
766 
767 /*
768  * Transfer the entries whose hash prefix ends in 1 to the new leaf.
769  */
770 void
771 zap_leaf_split(zap_leaf_t *l, zap_leaf_t *nl, boolean_t sort)
772 {
773 	int i;
774 	int bit = 64 - 1 - l->l_phys->l_hdr.lh_prefix_len;
775 
776 	/* set new prefix and prefix_len */
777 	l->l_phys->l_hdr.lh_prefix <<= 1;
778 	l->l_phys->l_hdr.lh_prefix_len++;
779 	nl->l_phys->l_hdr.lh_prefix = l->l_phys->l_hdr.lh_prefix | 1;
780 	nl->l_phys->l_hdr.lh_prefix_len = l->l_phys->l_hdr.lh_prefix_len;
781 
782 	/* break existing hash chains */
783 	zap_memset(l->l_phys->l_hash, CHAIN_END, 2*ZAP_LEAF_HASH_NUMENTRIES(l));
784 
785 	if (sort)
786 		l->l_phys->l_hdr.lh_flags |= ZLF_ENTRIES_CDSORTED;
787 
788 	/*
789 	 * Transfer entries whose hash bit 'bit' is set to nl; rehash
790 	 * the remaining entries
791 	 *
792 	 * NB: We could find entries via the hashtable instead. That
793 	 * would be O(hashents+numents) rather than O(numblks+numents),
794 	 * but this accesses memory more sequentially, and when we're
795 	 * called, the block is usually pretty full.
796 	 */
797 	for (i = 0; i < ZAP_LEAF_NUMCHUNKS(l); i++) {
798 		struct zap_leaf_entry *le = ZAP_LEAF_ENTRY(l, i);
799 		if (le->le_type != ZAP_CHUNK_ENTRY)
800 			continue;
801 
802 		if (le->le_hash & (1ULL << bit))
803 			zap_leaf_transfer_entry(l, i, nl);
804 		else
805 			(void) zap_leaf_rehash_entry(l, i);
806 	}
807 }
808 
809 void
810 zap_leaf_stats(zap_t *zap, zap_leaf_t *l, zap_stats_t *zs)
811 {
812 	int i, n;
813 
814 	n = zap->zap_f.zap_phys->zap_ptrtbl.zt_shift -
815 	    l->l_phys->l_hdr.lh_prefix_len;
816 	n = MIN(n, ZAP_HISTOGRAM_SIZE-1);
817 	zs->zs_leafs_with_2n_pointers[n]++;
818 
819 
820 	n = l->l_phys->l_hdr.lh_nentries/5;
821 	n = MIN(n, ZAP_HISTOGRAM_SIZE-1);
822 	zs->zs_blocks_with_n5_entries[n]++;
823 
824 	n = ((1<<FZAP_BLOCK_SHIFT(zap)) -
825 	    l->l_phys->l_hdr.lh_nfree * (ZAP_LEAF_ARRAY_BYTES+1))*10 /
826 	    (1<<FZAP_BLOCK_SHIFT(zap));
827 	n = MIN(n, ZAP_HISTOGRAM_SIZE-1);
828 	zs->zs_blocks_n_tenths_full[n]++;
829 
830 	for (i = 0; i < ZAP_LEAF_HASH_NUMENTRIES(l); i++) {
831 		int nentries = 0;
832 		int chunk = l->l_phys->l_hash[i];
833 
834 		while (chunk != CHAIN_END) {
835 			struct zap_leaf_entry *le =
836 			    ZAP_LEAF_ENTRY(l, chunk);
837 
838 			n = 1 + ZAP_LEAF_ARRAY_NCHUNKS(le->le_name_length) +
839 			    ZAP_LEAF_ARRAY_NCHUNKS(le->le_value_length *
840 			    le->le_int_size);
841 			n = MIN(n, ZAP_HISTOGRAM_SIZE-1);
842 			zs->zs_entries_using_n_chunks[n]++;
843 
844 			chunk = le->le_next;
845 			nentries++;
846 		}
847 
848 		n = nentries;
849 		n = MIN(n, ZAP_HISTOGRAM_SIZE-1);
850 		zs->zs_buckets_with_n_entries[n]++;
851 	}
852 }
853