xref: /freebsd/sys/contrib/openzfs/module/zfs/zap_leaf.c (revision 718519f4efc71096422fc71dab90b2a3369871ff)
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 https://opensource.org/licenses/CDDL-1.0.
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 /*
23  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
24  * Copyright (c) 2013, 2016 by Delphix. All rights reserved.
25  * Copyright 2017 Nexenta Systems, Inc.
26  */
27 
28 /*
29  * The 512-byte leaf is broken into 32 16-byte chunks.
30  * chunk number n means l_chunk[n], even though the header precedes it.
31  * the names are stored null-terminated.
32  */
33 
34 #include <sys/zio.h>
35 #include <sys/spa.h>
36 #include <sys/dmu.h>
37 #include <sys/zfs_context.h>
38 #include <sys/fs/zfs.h>
39 #include <sys/zap.h>
40 #include <sys/zap_impl.h>
41 #include <sys/zap_leaf.h>
42 #include <sys/arc.h>
43 
44 static uint16_t *zap_leaf_rehash_entry(zap_leaf_t *l, struct zap_leaf_entry *le,
45     uint16_t entry);
46 
47 #define	CHAIN_END 0xffff /* end of the chunk chain */
48 
49 #define	LEAF_HASH(l, h) \
50 	((ZAP_LEAF_HASH_NUMENTRIES(l)-1) & \
51 	((h) >> \
52 	(64 - ZAP_LEAF_HASH_SHIFT(l) - zap_leaf_phys(l)->l_hdr.lh_prefix_len)))
53 
54 #define	LEAF_HASH_ENTPTR(l, h)	(&zap_leaf_phys(l)->l_hash[LEAF_HASH(l, h)])
55 
56 static void
stv(int len,void * addr,uint64_t value)57 stv(int len, void *addr, uint64_t value)
58 {
59 	switch (len) {
60 	case 1:
61 		*(uint8_t *)addr = value;
62 		return;
63 	case 2:
64 		*(uint16_t *)addr = value;
65 		return;
66 	case 4:
67 		*(uint32_t *)addr = value;
68 		return;
69 	case 8:
70 		*(uint64_t *)addr = value;
71 		return;
72 	default:
73 		PANIC("bad int len %d", len);
74 	}
75 }
76 
77 static uint64_t
ldv(int len,const void * addr)78 ldv(int len, const void *addr)
79 {
80 	switch (len) {
81 	case 1:
82 		return (*(uint8_t *)addr);
83 	case 2:
84 		return (*(uint16_t *)addr);
85 	case 4:
86 		return (*(uint32_t *)addr);
87 	case 8:
88 		return (*(uint64_t *)addr);
89 	default:
90 		PANIC("bad int len %d", len);
91 	}
92 	return (0xFEEDFACEDEADBEEFULL);
93 }
94 
95 void
zap_leaf_byteswap(zap_leaf_phys_t * buf,size_t size)96 zap_leaf_byteswap(zap_leaf_phys_t *buf, size_t size)
97 {
98 	zap_leaf_t l;
99 	dmu_buf_t l_dbuf;
100 
101 	l_dbuf.db_data = buf;
102 	l.l_bs = highbit64(size) - 1;
103 	l.l_dbuf = &l_dbuf;
104 
105 	buf->l_hdr.lh_block_type =	BSWAP_64(buf->l_hdr.lh_block_type);
106 	buf->l_hdr.lh_prefix =		BSWAP_64(buf->l_hdr.lh_prefix);
107 	buf->l_hdr.lh_magic =		BSWAP_32(buf->l_hdr.lh_magic);
108 	buf->l_hdr.lh_nfree =		BSWAP_16(buf->l_hdr.lh_nfree);
109 	buf->l_hdr.lh_nentries =	BSWAP_16(buf->l_hdr.lh_nentries);
110 	buf->l_hdr.lh_prefix_len =	BSWAP_16(buf->l_hdr.lh_prefix_len);
111 	buf->l_hdr.lh_freelist =	BSWAP_16(buf->l_hdr.lh_freelist);
112 
113 	for (uint_t i = 0; i < ZAP_LEAF_HASH_NUMENTRIES(&l); i++)
114 		buf->l_hash[i] = BSWAP_16(buf->l_hash[i]);
115 
116 	for (uint_t i = 0; i < ZAP_LEAF_NUMCHUNKS(&l); i++) {
117 		zap_leaf_chunk_t *lc = &ZAP_LEAF_CHUNK(&l, i);
118 		struct zap_leaf_entry *le;
119 
120 		switch (lc->l_free.lf_type) {
121 		case ZAP_CHUNK_ENTRY:
122 			le = &lc->l_entry;
123 
124 			le->le_type =		BSWAP_8(le->le_type);
125 			le->le_value_intlen =	BSWAP_8(le->le_value_intlen);
126 			le->le_next =		BSWAP_16(le->le_next);
127 			le->le_name_chunk =	BSWAP_16(le->le_name_chunk);
128 			le->le_name_numints =	BSWAP_16(le->le_name_numints);
129 			le->le_value_chunk =	BSWAP_16(le->le_value_chunk);
130 			le->le_value_numints =	BSWAP_16(le->le_value_numints);
131 			le->le_cd =		BSWAP_32(le->le_cd);
132 			le->le_hash =		BSWAP_64(le->le_hash);
133 			break;
134 		case ZAP_CHUNK_FREE:
135 			lc->l_free.lf_type =	BSWAP_8(lc->l_free.lf_type);
136 			lc->l_free.lf_next =	BSWAP_16(lc->l_free.lf_next);
137 			break;
138 		case ZAP_CHUNK_ARRAY:
139 			lc->l_array.la_type =	BSWAP_8(lc->l_array.la_type);
140 			lc->l_array.la_next =	BSWAP_16(lc->l_array.la_next);
141 			/* la_array doesn't need swapping */
142 			break;
143 		default:
144 			cmn_err(CE_PANIC, "bad leaf type %d",
145 			    lc->l_free.lf_type);
146 		}
147 	}
148 }
149 
150 void
zap_leaf_init(zap_leaf_t * l,boolean_t sort)151 zap_leaf_init(zap_leaf_t *l, boolean_t sort)
152 {
153 	l->l_bs = highbit64(l->l_dbuf->db_size) - 1;
154 	memset(&zap_leaf_phys(l)->l_hdr, 0,
155 	    sizeof (struct zap_leaf_header));
156 	memset(zap_leaf_phys(l)->l_hash, CHAIN_END,
157 	    2*ZAP_LEAF_HASH_NUMENTRIES(l));
158 	for (uint_t i = 0; i < ZAP_LEAF_NUMCHUNKS(l); i++) {
159 		ZAP_LEAF_CHUNK(l, i).l_free.lf_type = ZAP_CHUNK_FREE;
160 		ZAP_LEAF_CHUNK(l, i).l_free.lf_next = i+1;
161 	}
162 	ZAP_LEAF_CHUNK(l, ZAP_LEAF_NUMCHUNKS(l)-1).l_free.lf_next = CHAIN_END;
163 	zap_leaf_phys(l)->l_hdr.lh_block_type = ZBT_LEAF;
164 	zap_leaf_phys(l)->l_hdr.lh_magic = ZAP_LEAF_MAGIC;
165 	zap_leaf_phys(l)->l_hdr.lh_nfree = ZAP_LEAF_NUMCHUNKS(l);
166 	if (sort)
167 		zap_leaf_phys(l)->l_hdr.lh_flags |= ZLF_ENTRIES_CDSORTED;
168 }
169 
170 /*
171  * Routines which manipulate leaf chunks (l_chunk[]).
172  */
173 
174 static uint16_t
zap_leaf_chunk_alloc(zap_leaf_t * l)175 zap_leaf_chunk_alloc(zap_leaf_t *l)
176 {
177 	ASSERT(zap_leaf_phys(l)->l_hdr.lh_nfree > 0);
178 
179 	uint_t chunk = zap_leaf_phys(l)->l_hdr.lh_freelist;
180 	ASSERT3U(chunk, <, ZAP_LEAF_NUMCHUNKS(l));
181 	ASSERT3U(ZAP_LEAF_CHUNK(l, chunk).l_free.lf_type, ==, ZAP_CHUNK_FREE);
182 
183 	zap_leaf_phys(l)->l_hdr.lh_freelist =
184 	    ZAP_LEAF_CHUNK(l, chunk).l_free.lf_next;
185 
186 	zap_leaf_phys(l)->l_hdr.lh_nfree--;
187 
188 	return (chunk);
189 }
190 
191 static void
zap_leaf_chunk_free(zap_leaf_t * l,uint16_t chunk)192 zap_leaf_chunk_free(zap_leaf_t *l, uint16_t chunk)
193 {
194 	struct zap_leaf_free *zlf = &ZAP_LEAF_CHUNK(l, chunk).l_free;
195 	ASSERT3U(zap_leaf_phys(l)->l_hdr.lh_nfree, <, ZAP_LEAF_NUMCHUNKS(l));
196 	ASSERT3U(chunk, <, ZAP_LEAF_NUMCHUNKS(l));
197 	ASSERT(zlf->lf_type != ZAP_CHUNK_FREE);
198 
199 	zlf->lf_type = ZAP_CHUNK_FREE;
200 	zlf->lf_next = zap_leaf_phys(l)->l_hdr.lh_freelist;
201 	memset(zlf->lf_pad, 0, sizeof (zlf->lf_pad)); /* help it to compress */
202 	zap_leaf_phys(l)->l_hdr.lh_freelist = chunk;
203 
204 	zap_leaf_phys(l)->l_hdr.lh_nfree++;
205 }
206 
207 /*
208  * Routines which manipulate leaf arrays (zap_leaf_array type chunks).
209  */
210 
211 static uint16_t
zap_leaf_array_create(zap_leaf_t * l,const char * buf,int integer_size,int num_integers)212 zap_leaf_array_create(zap_leaf_t *l, const char *buf,
213     int integer_size, int num_integers)
214 {
215 	uint16_t chunk_head;
216 	uint16_t *chunkp = &chunk_head;
217 	int byten = integer_size;
218 	uint64_t value = 0;
219 	int shift = (integer_size - 1) * 8;
220 	int len = num_integers;
221 
222 	ASSERT3U(num_integers * integer_size, <=, ZAP_MAXVALUELEN);
223 
224 	if (len > 0)
225 		value = ldv(integer_size, buf);
226 	while (len > 0) {
227 		uint16_t chunk = zap_leaf_chunk_alloc(l);
228 		struct zap_leaf_array *la = &ZAP_LEAF_CHUNK(l, chunk).l_array;
229 
230 		la->la_type = ZAP_CHUNK_ARRAY;
231 		for (int i = 0; i < ZAP_LEAF_ARRAY_BYTES; i++) {
232 			la->la_array[i] = value >> shift;
233 			value <<= 8;
234 			if (--byten == 0) {
235 				if (--len == 0)
236 					break;
237 				byten = integer_size;
238 				buf += integer_size;
239 				value = ldv(integer_size, buf);
240 			}
241 		}
242 
243 		*chunkp = chunk;
244 		chunkp = &la->la_next;
245 	}
246 	*chunkp = CHAIN_END;
247 
248 	return (chunk_head);
249 }
250 
251 /*
252  * Non-destructively copy array between leaves.
253  */
254 static uint16_t
zap_leaf_array_copy(zap_leaf_t * l,uint16_t chunk,zap_leaf_t * nl)255 zap_leaf_array_copy(zap_leaf_t *l, uint16_t chunk, zap_leaf_t *nl)
256 {
257 	uint16_t new_chunk;
258 	uint16_t *nchunkp = &new_chunk;
259 
260 	while (chunk != CHAIN_END) {
261 		ASSERT3U(chunk, <, ZAP_LEAF_NUMCHUNKS(l));
262 		uint16_t nchunk = zap_leaf_chunk_alloc(nl);
263 
264 		struct zap_leaf_array *la =
265 		    &ZAP_LEAF_CHUNK(l, chunk).l_array;
266 		struct zap_leaf_array *nla =
267 		    &ZAP_LEAF_CHUNK(nl, nchunk).l_array;
268 		ASSERT3U(la->la_type, ==, ZAP_CHUNK_ARRAY);
269 
270 		*nla = *la; /* structure assignment */
271 
272 		chunk = la->la_next;
273 		*nchunkp = nchunk;
274 		nchunkp = &nla->la_next;
275 	}
276 	*nchunkp = CHAIN_END;
277 	return (new_chunk);
278 }
279 
280 /*
281  * Free array.  Unlike trivial loop of zap_leaf_chunk_free() this does
282  * not reverse order of chunks in the free list, reducing fragmentation.
283  */
284 static void
zap_leaf_array_free(zap_leaf_t * l,uint16_t chunk)285 zap_leaf_array_free(zap_leaf_t *l, uint16_t chunk)
286 {
287 	struct zap_leaf_header *hdr = &zap_leaf_phys(l)->l_hdr;
288 	uint16_t *tailp = &hdr->lh_freelist;
289 	uint16_t oldfree = *tailp;
290 
291 	while (chunk != CHAIN_END) {
292 		ASSERT3U(chunk, <, ZAP_LEAF_NUMCHUNKS(l));
293 		zap_leaf_chunk_t *c = &ZAP_LEAF_CHUNK(l, chunk);
294 		ASSERT3U(c->l_array.la_type, ==, ZAP_CHUNK_ARRAY);
295 
296 		*tailp = chunk;
297 		chunk = c->l_array.la_next;
298 
299 		c->l_free.lf_type = ZAP_CHUNK_FREE;
300 		memset(c->l_free.lf_pad, 0, sizeof (c->l_free.lf_pad));
301 		tailp = &c->l_free.lf_next;
302 
303 		ASSERT3U(hdr->lh_nfree, <, ZAP_LEAF_NUMCHUNKS(l));
304 		hdr->lh_nfree++;
305 	}
306 
307 	*tailp = oldfree;
308 }
309 
310 /* array_len and buf_len are in integers, not bytes */
311 static void
zap_leaf_array_read(zap_leaf_t * l,uint16_t chunk,int array_int_len,int array_len,int buf_int_len,uint64_t buf_len,void * buf)312 zap_leaf_array_read(zap_leaf_t *l, uint16_t chunk,
313     int array_int_len, int array_len, int buf_int_len, uint64_t buf_len,
314     void *buf)
315 {
316 	int len = MIN(array_len, buf_len);
317 	int byten = 0;
318 	uint64_t value = 0;
319 	char *p = buf;
320 
321 	ASSERT3U(array_int_len, <=, buf_int_len);
322 
323 	/* Fast path for one 8-byte integer */
324 	if (array_int_len == 8 && buf_int_len == 8 && len == 1) {
325 		struct zap_leaf_array *la = &ZAP_LEAF_CHUNK(l, chunk).l_array;
326 		uint8_t *ip = la->la_array;
327 		uint64_t *buf64 = buf;
328 
329 		*buf64 = (uint64_t)ip[0] << 56 | (uint64_t)ip[1] << 48 |
330 		    (uint64_t)ip[2] << 40 | (uint64_t)ip[3] << 32 |
331 		    (uint64_t)ip[4] << 24 | (uint64_t)ip[5] << 16 |
332 		    (uint64_t)ip[6] << 8 | (uint64_t)ip[7];
333 		return;
334 	}
335 
336 	/* Fast path for an array of 1-byte integers (eg. the entry name) */
337 	if (array_int_len == 1 && buf_int_len == 1 &&
338 	    buf_len > array_len + ZAP_LEAF_ARRAY_BYTES) {
339 		while (chunk != CHAIN_END) {
340 			struct zap_leaf_array *la =
341 			    &ZAP_LEAF_CHUNK(l, chunk).l_array;
342 			memcpy(p, la->la_array, ZAP_LEAF_ARRAY_BYTES);
343 			p += ZAP_LEAF_ARRAY_BYTES;
344 			chunk = la->la_next;
345 		}
346 		return;
347 	}
348 
349 	while (len > 0) {
350 		struct zap_leaf_array *la = &ZAP_LEAF_CHUNK(l, chunk).l_array;
351 
352 		ASSERT3U(chunk, <, ZAP_LEAF_NUMCHUNKS(l));
353 		for (int i = 0; i < ZAP_LEAF_ARRAY_BYTES; i++) {
354 			value = (value << 8) | la->la_array[i];
355 			byten++;
356 			if (byten == array_int_len) {
357 				stv(buf_int_len, p, value);
358 				byten = 0;
359 				len--;
360 				if (len == 0)
361 					return;
362 				p += buf_int_len;
363 			}
364 		}
365 		chunk = la->la_next;
366 	}
367 }
368 
369 static boolean_t
zap_leaf_array_match(zap_leaf_t * l,zap_name_t * zn,uint_t chunk,int array_numints)370 zap_leaf_array_match(zap_leaf_t *l, zap_name_t *zn,
371     uint_t chunk, int array_numints)
372 {
373 	int bseen = 0;
374 
375 	if (zap_getflags(zn->zn_zap) & ZAP_FLAG_UINT64_KEY) {
376 		uint64_t *thiskey =
377 		    kmem_alloc(array_numints * sizeof (*thiskey), KM_SLEEP);
378 		ASSERT(zn->zn_key_intlen == sizeof (*thiskey));
379 
380 		zap_leaf_array_read(l, chunk, sizeof (*thiskey), array_numints,
381 		    sizeof (*thiskey), array_numints, thiskey);
382 		boolean_t match = memcmp(thiskey, zn->zn_key_orig,
383 		    array_numints * sizeof (*thiskey)) == 0;
384 		kmem_free(thiskey, array_numints * sizeof (*thiskey));
385 		return (match);
386 	}
387 
388 	ASSERT(zn->zn_key_intlen == 1);
389 	if (zn->zn_matchtype & MT_NORMALIZE) {
390 		char *thisname = kmem_alloc(array_numints, KM_SLEEP);
391 
392 		zap_leaf_array_read(l, chunk, sizeof (char), array_numints,
393 		    sizeof (char), array_numints, thisname);
394 		boolean_t match = zap_match(zn, thisname);
395 		kmem_free(thisname, array_numints);
396 		return (match);
397 	}
398 
399 	/*
400 	 * Fast path for exact matching.
401 	 * First check that the lengths match, so that we don't read
402 	 * past the end of the zn_key_orig array.
403 	 */
404 	if (array_numints != zn->zn_key_orig_numints)
405 		return (B_FALSE);
406 	while (bseen < array_numints) {
407 		struct zap_leaf_array *la = &ZAP_LEAF_CHUNK(l, chunk).l_array;
408 		int toread = MIN(array_numints - bseen, ZAP_LEAF_ARRAY_BYTES);
409 		ASSERT3U(chunk, <, ZAP_LEAF_NUMCHUNKS(l));
410 		if (memcmp(la->la_array, (char *)zn->zn_key_orig + bseen,
411 		    toread))
412 			break;
413 		chunk = la->la_next;
414 		bseen += toread;
415 	}
416 	return (bseen == array_numints);
417 }
418 
419 /*
420  * Routines which manipulate leaf entries.
421  */
422 
423 int
zap_leaf_lookup(zap_leaf_t * l,zap_name_t * zn,zap_entry_handle_t * zeh)424 zap_leaf_lookup(zap_leaf_t *l, zap_name_t *zn, zap_entry_handle_t *zeh)
425 {
426 	struct zap_leaf_entry *le;
427 
428 	ASSERT3U(zap_leaf_phys(l)->l_hdr.lh_magic, ==, ZAP_LEAF_MAGIC);
429 
430 	for (uint16_t *chunkp = LEAF_HASH_ENTPTR(l, zn->zn_hash);
431 	    *chunkp != CHAIN_END; chunkp = &le->le_next) {
432 		uint16_t chunk = *chunkp;
433 		le = ZAP_LEAF_ENTRY(l, chunk);
434 
435 		ASSERT3U(chunk, <, ZAP_LEAF_NUMCHUNKS(l));
436 		ASSERT3U(le->le_type, ==, ZAP_CHUNK_ENTRY);
437 
438 		if (le->le_hash != zn->zn_hash)
439 			continue;
440 
441 		/*
442 		 * NB: the entry chain is always sorted by cd on
443 		 * normalized zap objects, so this will find the
444 		 * lowest-cd match for MT_NORMALIZE.
445 		 */
446 		ASSERT((zn->zn_matchtype == 0) ||
447 		    (zap_leaf_phys(l)->l_hdr.lh_flags & ZLF_ENTRIES_CDSORTED));
448 		if (zap_leaf_array_match(l, zn, le->le_name_chunk,
449 		    le->le_name_numints)) {
450 			zeh->zeh_num_integers = le->le_value_numints;
451 			zeh->zeh_integer_size = le->le_value_intlen;
452 			zeh->zeh_cd = le->le_cd;
453 			zeh->zeh_hash = le->le_hash;
454 			zeh->zeh_chunkp = chunkp;
455 			zeh->zeh_leaf = l;
456 			return (0);
457 		}
458 	}
459 
460 	return (SET_ERROR(ENOENT));
461 }
462 
463 /* Return (h1,cd1 >= h2,cd2) */
464 #define	HCD_GTEQ(h1, cd1, h2, cd2) \
465 	((h1 > h2) ? TRUE : ((h1 == h2 && cd1 >= cd2) ? TRUE : FALSE))
466 
467 int
zap_leaf_lookup_closest(zap_leaf_t * l,uint64_t h,uint32_t cd,zap_entry_handle_t * zeh)468 zap_leaf_lookup_closest(zap_leaf_t *l,
469     uint64_t h, uint32_t cd, zap_entry_handle_t *zeh)
470 {
471 	uint64_t besth = -1ULL;
472 	uint32_t bestcd = -1U;
473 	uint16_t bestlh = ZAP_LEAF_HASH_NUMENTRIES(l)-1;
474 	struct zap_leaf_entry *le;
475 
476 	ASSERT3U(zap_leaf_phys(l)->l_hdr.lh_magic, ==, ZAP_LEAF_MAGIC);
477 
478 	for (uint16_t lh = LEAF_HASH(l, h); lh <= bestlh; lh++) {
479 		for (uint16_t chunk = zap_leaf_phys(l)->l_hash[lh];
480 		    chunk != CHAIN_END; chunk = le->le_next) {
481 			le = ZAP_LEAF_ENTRY(l, chunk);
482 
483 			ASSERT3U(chunk, <, ZAP_LEAF_NUMCHUNKS(l));
484 			ASSERT3U(le->le_type, ==, ZAP_CHUNK_ENTRY);
485 
486 			if (HCD_GTEQ(le->le_hash, le->le_cd, h, cd) &&
487 			    HCD_GTEQ(besth, bestcd, le->le_hash, le->le_cd)) {
488 				ASSERT3U(bestlh, >=, lh);
489 				bestlh = lh;
490 				besth = le->le_hash;
491 				bestcd = le->le_cd;
492 
493 				zeh->zeh_num_integers = le->le_value_numints;
494 				zeh->zeh_integer_size = le->le_value_intlen;
495 				zeh->zeh_cd = le->le_cd;
496 				zeh->zeh_hash = le->le_hash;
497 				zeh->zeh_fakechunk = chunk;
498 				zeh->zeh_chunkp = &zeh->zeh_fakechunk;
499 				zeh->zeh_leaf = l;
500 			}
501 		}
502 	}
503 
504 	return (bestcd == -1U ? SET_ERROR(ENOENT) : 0);
505 }
506 
507 int
zap_entry_read(const zap_entry_handle_t * zeh,uint8_t integer_size,uint64_t num_integers,void * buf)508 zap_entry_read(const zap_entry_handle_t *zeh,
509     uint8_t integer_size, uint64_t num_integers, void *buf)
510 {
511 	struct zap_leaf_entry *le =
512 	    ZAP_LEAF_ENTRY(zeh->zeh_leaf, *zeh->zeh_chunkp);
513 	ASSERT3U(le->le_type, ==, ZAP_CHUNK_ENTRY);
514 
515 	if (le->le_value_intlen > integer_size)
516 		return (SET_ERROR(EINVAL));
517 
518 	zap_leaf_array_read(zeh->zeh_leaf, le->le_value_chunk,
519 	    le->le_value_intlen, le->le_value_numints,
520 	    integer_size, num_integers, buf);
521 
522 	if (zeh->zeh_num_integers > num_integers)
523 		return (SET_ERROR(EOVERFLOW));
524 	return (0);
525 
526 }
527 
528 int
zap_entry_read_name(zap_t * zap,const zap_entry_handle_t * zeh,uint16_t buflen,char * buf)529 zap_entry_read_name(zap_t *zap, const zap_entry_handle_t *zeh, uint16_t buflen,
530     char *buf)
531 {
532 	struct zap_leaf_entry *le =
533 	    ZAP_LEAF_ENTRY(zeh->zeh_leaf, *zeh->zeh_chunkp);
534 	ASSERT3U(le->le_type, ==, ZAP_CHUNK_ENTRY);
535 
536 	if (zap_getflags(zap) & ZAP_FLAG_UINT64_KEY) {
537 		zap_leaf_array_read(zeh->zeh_leaf, le->le_name_chunk, 8,
538 		    le->le_name_numints, 8, buflen / 8, buf);
539 	} else {
540 		zap_leaf_array_read(zeh->zeh_leaf, le->le_name_chunk, 1,
541 		    le->le_name_numints, 1, buflen, buf);
542 	}
543 	if (le->le_name_numints > buflen)
544 		return (SET_ERROR(EOVERFLOW));
545 	return (0);
546 }
547 
548 int
zap_entry_update(zap_entry_handle_t * zeh,uint8_t integer_size,uint64_t num_integers,const void * buf)549 zap_entry_update(zap_entry_handle_t *zeh,
550     uint8_t integer_size, uint64_t num_integers, const void *buf)
551 {
552 	zap_leaf_t *l = zeh->zeh_leaf;
553 	struct zap_leaf_entry *le = ZAP_LEAF_ENTRY(l, *zeh->zeh_chunkp);
554 
555 	int delta_chunks = ZAP_LEAF_ARRAY_NCHUNKS(num_integers * integer_size) -
556 	    ZAP_LEAF_ARRAY_NCHUNKS(le->le_value_numints * le->le_value_intlen);
557 
558 	if ((int)zap_leaf_phys(l)->l_hdr.lh_nfree < delta_chunks)
559 		return (SET_ERROR(EAGAIN));
560 
561 	zap_leaf_array_free(l, le->le_value_chunk);
562 	le->le_value_chunk =
563 	    zap_leaf_array_create(l, buf, integer_size, num_integers);
564 	le->le_value_numints = num_integers;
565 	le->le_value_intlen = integer_size;
566 	return (0);
567 }
568 
569 void
zap_entry_remove(zap_entry_handle_t * zeh)570 zap_entry_remove(zap_entry_handle_t *zeh)
571 {
572 	zap_leaf_t *l = zeh->zeh_leaf;
573 
574 	ASSERT3P(zeh->zeh_chunkp, !=, &zeh->zeh_fakechunk);
575 
576 	uint16_t entry_chunk = *zeh->zeh_chunkp;
577 	struct zap_leaf_entry *le = ZAP_LEAF_ENTRY(l, entry_chunk);
578 	ASSERT3U(le->le_type, ==, ZAP_CHUNK_ENTRY);
579 
580 	*zeh->zeh_chunkp = le->le_next;
581 
582 	/* Free in opposite order to reduce fragmentation. */
583 	zap_leaf_array_free(l, le->le_value_chunk);
584 	zap_leaf_array_free(l, le->le_name_chunk);
585 	zap_leaf_chunk_free(l, entry_chunk);
586 
587 	zap_leaf_phys(l)->l_hdr.lh_nentries--;
588 }
589 
590 int
zap_entry_create(zap_leaf_t * l,zap_name_t * zn,uint32_t cd,uint8_t integer_size,uint64_t num_integers,const void * buf,zap_entry_handle_t * zeh)591 zap_entry_create(zap_leaf_t *l, zap_name_t *zn, uint32_t cd,
592     uint8_t integer_size, uint64_t num_integers, const void *buf,
593     zap_entry_handle_t *zeh)
594 {
595 	uint16_t chunk;
596 	struct zap_leaf_entry *le;
597 	uint64_t h = zn->zn_hash;
598 
599 	uint64_t valuelen = integer_size * num_integers;
600 
601 	uint_t numchunks = 1 + ZAP_LEAF_ARRAY_NCHUNKS(zn->zn_key_orig_numints *
602 	    zn->zn_key_intlen) + ZAP_LEAF_ARRAY_NCHUNKS(valuelen);
603 	if (numchunks > ZAP_LEAF_NUMCHUNKS(l))
604 		return (SET_ERROR(E2BIG));
605 
606 	if (cd == ZAP_NEED_CD) {
607 		/* find the lowest unused cd */
608 		if (zap_leaf_phys(l)->l_hdr.lh_flags & ZLF_ENTRIES_CDSORTED) {
609 			cd = 0;
610 
611 			for (chunk = *LEAF_HASH_ENTPTR(l, h);
612 			    chunk != CHAIN_END; chunk = le->le_next) {
613 				le = ZAP_LEAF_ENTRY(l, chunk);
614 				if (le->le_cd > cd)
615 					break;
616 				if (le->le_hash == h) {
617 					ASSERT3U(cd, ==, le->le_cd);
618 					cd++;
619 				}
620 			}
621 		} else {
622 			/* old unsorted format; do it the O(n^2) way */
623 			for (cd = 0; ; cd++) {
624 				for (chunk = *LEAF_HASH_ENTPTR(l, h);
625 				    chunk != CHAIN_END; chunk = le->le_next) {
626 					le = ZAP_LEAF_ENTRY(l, chunk);
627 					if (le->le_hash == h &&
628 					    le->le_cd == cd) {
629 						break;
630 					}
631 				}
632 				/* If this cd is not in use, we are good. */
633 				if (chunk == CHAIN_END)
634 					break;
635 			}
636 		}
637 		/*
638 		 * We would run out of space in a block before we could
639 		 * store enough entries to run out of CD values.
640 		 */
641 		ASSERT3U(cd, <, zap_maxcd(zn->zn_zap));
642 	}
643 
644 	if (zap_leaf_phys(l)->l_hdr.lh_nfree < numchunks)
645 		return (SET_ERROR(EAGAIN));
646 
647 	/* make the entry */
648 	chunk = zap_leaf_chunk_alloc(l);
649 	le = ZAP_LEAF_ENTRY(l, chunk);
650 	le->le_type = ZAP_CHUNK_ENTRY;
651 	le->le_name_chunk = zap_leaf_array_create(l, zn->zn_key_orig,
652 	    zn->zn_key_intlen, zn->zn_key_orig_numints);
653 	le->le_name_numints = zn->zn_key_orig_numints;
654 	le->le_value_chunk =
655 	    zap_leaf_array_create(l, buf, integer_size, num_integers);
656 	le->le_value_numints = num_integers;
657 	le->le_value_intlen = integer_size;
658 	le->le_hash = h;
659 	le->le_cd = cd;
660 
661 	/* link it into the hash chain */
662 	/* XXX if we did the search above, we could just use that */
663 	uint16_t *chunkp = zap_leaf_rehash_entry(l, le, chunk);
664 
665 	zap_leaf_phys(l)->l_hdr.lh_nentries++;
666 
667 	zeh->zeh_leaf = l;
668 	zeh->zeh_num_integers = num_integers;
669 	zeh->zeh_integer_size = le->le_value_intlen;
670 	zeh->zeh_cd = le->le_cd;
671 	zeh->zeh_hash = le->le_hash;
672 	zeh->zeh_chunkp = chunkp;
673 
674 	return (0);
675 }
676 
677 /*
678  * Determine if there is another entry with the same normalized form.
679  * For performance purposes, either zn or name must be provided (the
680  * other can be NULL).  Note, there usually won't be any hash
681  * conflicts, in which case we don't need the concatenated/normalized
682  * form of the name.  But all callers have one of these on hand anyway,
683  * so might as well take advantage.  A cleaner but slower interface
684  * would accept neither argument, and compute the normalized name as
685  * needed (using zap_name_alloc_str(zap_entry_read_name(zeh))).
686  */
687 boolean_t
zap_entry_normalization_conflict(zap_entry_handle_t * zeh,zap_name_t * zn,const char * name,zap_t * zap)688 zap_entry_normalization_conflict(zap_entry_handle_t *zeh, zap_name_t *zn,
689     const char *name, zap_t *zap)
690 {
691 	struct zap_leaf_entry *le;
692 	boolean_t allocdzn = B_FALSE;
693 
694 	if (zap->zap_normflags == 0)
695 		return (B_FALSE);
696 
697 	for (uint16_t chunk = *LEAF_HASH_ENTPTR(zeh->zeh_leaf, zeh->zeh_hash);
698 	    chunk != CHAIN_END; chunk = le->le_next) {
699 		le = ZAP_LEAF_ENTRY(zeh->zeh_leaf, chunk);
700 		if (le->le_hash != zeh->zeh_hash)
701 			continue;
702 		if (le->le_cd == zeh->zeh_cd)
703 			continue;
704 
705 		if (zn == NULL) {
706 			zn = zap_name_alloc_str(zap, name, MT_NORMALIZE);
707 			allocdzn = B_TRUE;
708 		}
709 		if (zap_leaf_array_match(zeh->zeh_leaf, zn,
710 		    le->le_name_chunk, le->le_name_numints)) {
711 			if (allocdzn)
712 				zap_name_free(zn);
713 			return (B_TRUE);
714 		}
715 	}
716 	if (allocdzn)
717 		zap_name_free(zn);
718 	return (B_FALSE);
719 }
720 
721 /*
722  * Routines for transferring entries between leafs.
723  */
724 
725 static uint16_t *
zap_leaf_rehash_entry(zap_leaf_t * l,struct zap_leaf_entry * le,uint16_t entry)726 zap_leaf_rehash_entry(zap_leaf_t *l, struct zap_leaf_entry *le, uint16_t entry)
727 {
728 	struct zap_leaf_entry *le2;
729 	uint16_t *chunkp;
730 
731 	/*
732 	 * keep the entry chain sorted by cd
733 	 * NB: this will not cause problems for unsorted leafs, though
734 	 * it is unnecessary there.
735 	 */
736 	for (chunkp = LEAF_HASH_ENTPTR(l, le->le_hash);
737 	    *chunkp != CHAIN_END; chunkp = &le2->le_next) {
738 		le2 = ZAP_LEAF_ENTRY(l, *chunkp);
739 		if (le2->le_cd > le->le_cd)
740 			break;
741 	}
742 
743 	le->le_next = *chunkp;
744 	*chunkp = entry;
745 	return (chunkp);
746 }
747 
748 static void
zap_leaf_transfer_entry(zap_leaf_t * l,uint_t entry,zap_leaf_t * nl)749 zap_leaf_transfer_entry(zap_leaf_t *l, uint_t entry, zap_leaf_t *nl)
750 {
751 	struct zap_leaf_entry *le = ZAP_LEAF_ENTRY(l, entry);
752 	ASSERT3U(le->le_type, ==, ZAP_CHUNK_ENTRY);
753 
754 	uint16_t chunk = zap_leaf_chunk_alloc(nl);
755 	struct zap_leaf_entry *nle = ZAP_LEAF_ENTRY(nl, chunk);
756 	*nle = *le; /* structure assignment */
757 
758 	(void) zap_leaf_rehash_entry(nl, nle, chunk);
759 
760 	nle->le_name_chunk = zap_leaf_array_copy(l, le->le_name_chunk, nl);
761 	nle->le_value_chunk = zap_leaf_array_copy(l, le->le_value_chunk, nl);
762 
763 	/* Free in opposite order to reduce fragmentation. */
764 	zap_leaf_array_free(l, le->le_value_chunk);
765 	zap_leaf_array_free(l, le->le_name_chunk);
766 	zap_leaf_chunk_free(l, entry);
767 
768 	zap_leaf_phys(l)->l_hdr.lh_nentries--;
769 	zap_leaf_phys(nl)->l_hdr.lh_nentries++;
770 }
771 
772 /*
773  * Transfer the entries whose hash prefix ends in 1 to the new leaf.
774  */
775 void
zap_leaf_split(zap_leaf_t * l,zap_leaf_t * nl,boolean_t sort)776 zap_leaf_split(zap_leaf_t *l, zap_leaf_t *nl, boolean_t sort)
777 {
778 	uint_t bit = 64 - 1 - zap_leaf_phys(l)->l_hdr.lh_prefix_len;
779 
780 	/* set new prefix and prefix_len */
781 	zap_leaf_phys(l)->l_hdr.lh_prefix <<= 1;
782 	zap_leaf_phys(l)->l_hdr.lh_prefix_len++;
783 	zap_leaf_phys(nl)->l_hdr.lh_prefix =
784 	    zap_leaf_phys(l)->l_hdr.lh_prefix | 1;
785 	zap_leaf_phys(nl)->l_hdr.lh_prefix_len =
786 	    zap_leaf_phys(l)->l_hdr.lh_prefix_len;
787 
788 	/* break existing hash chains */
789 	memset(zap_leaf_phys(l)->l_hash, CHAIN_END,
790 	    2*ZAP_LEAF_HASH_NUMENTRIES(l));
791 
792 	if (sort)
793 		zap_leaf_phys(l)->l_hdr.lh_flags |= ZLF_ENTRIES_CDSORTED;
794 
795 	/*
796 	 * Transfer entries whose hash bit 'bit' is set to nl; rehash
797 	 * the remaining entries
798 	 *
799 	 * NB: We could find entries via the hashtable instead. That
800 	 * would be O(hashents+numents) rather than O(numblks+numents),
801 	 * but this accesses memory more sequentially, and when we're
802 	 * called, the block is usually pretty full.
803 	 */
804 	for (uint_t i = 0; i < ZAP_LEAF_NUMCHUNKS(l); i++) {
805 		struct zap_leaf_entry *le = ZAP_LEAF_ENTRY(l, i);
806 		if (le->le_type != ZAP_CHUNK_ENTRY)
807 			continue;
808 
809 		if (le->le_hash & (1ULL << bit))
810 			zap_leaf_transfer_entry(l, i, nl);
811 		else
812 			(void) zap_leaf_rehash_entry(l, le, i);
813 	}
814 }
815 
816 void
zap_leaf_stats(zap_t * zap,zap_leaf_t * l,zap_stats_t * zs)817 zap_leaf_stats(zap_t *zap, zap_leaf_t *l, zap_stats_t *zs)
818 {
819 	uint_t n = zap_f_phys(zap)->zap_ptrtbl.zt_shift -
820 	    zap_leaf_phys(l)->l_hdr.lh_prefix_len;
821 	n = MIN(n, ZAP_HISTOGRAM_SIZE-1);
822 	zs->zs_leafs_with_2n_pointers[n]++;
823 
824 
825 	n = zap_leaf_phys(l)->l_hdr.lh_nentries/5;
826 	n = MIN(n, ZAP_HISTOGRAM_SIZE-1);
827 	zs->zs_blocks_with_n5_entries[n]++;
828 
829 	n = ((1<<FZAP_BLOCK_SHIFT(zap)) -
830 	    zap_leaf_phys(l)->l_hdr.lh_nfree * (ZAP_LEAF_ARRAY_BYTES+1))*10 /
831 	    (1<<FZAP_BLOCK_SHIFT(zap));
832 	n = MIN(n, ZAP_HISTOGRAM_SIZE-1);
833 	zs->zs_blocks_n_tenths_full[n]++;
834 
835 	for (uint_t i = 0; i < ZAP_LEAF_HASH_NUMENTRIES(l); i++) {
836 		uint_t nentries = 0;
837 		uint_t chunk = zap_leaf_phys(l)->l_hash[i];
838 
839 		while (chunk != CHAIN_END) {
840 			struct zap_leaf_entry *le =
841 			    ZAP_LEAF_ENTRY(l, chunk);
842 
843 			n = 1 + ZAP_LEAF_ARRAY_NCHUNKS(le->le_name_numints) +
844 			    ZAP_LEAF_ARRAY_NCHUNKS(le->le_value_numints *
845 			    le->le_value_intlen);
846 			n = MIN(n, ZAP_HISTOGRAM_SIZE-1);
847 			zs->zs_entries_using_n_chunks[n]++;
848 
849 			chunk = le->le_next;
850 			nentries++;
851 		}
852 
853 		n = nentries;
854 		n = MIN(n, ZAP_HISTOGRAM_SIZE-1);
855 		zs->zs_buckets_with_n_entries[n]++;
856 	}
857 }
858