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 (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
23  * Copyright (c) 2013, 2015 by Delphix. All rights reserved.
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/zio.h>
33 #include <sys/spa.h>
34 #include <sys/dmu.h>
35 #include <sys/zfs_context.h>
36 #include <sys/fs/zfs.h>
37 #include <sys/zap.h>
38 #include <sys/zap_impl.h>
39 #include <sys/zap_leaf.h>
40 #include <sys/arc.h>
41 
42 static uint16_t *zap_leaf_rehash_entry(zap_leaf_t *l, uint16_t entry);
43 
44 #define   CHAIN_END 0xffff /* end of the chunk chain */
45 
46 /* half the (current) minimum block size */
47 #define   MAX_ARRAY_BYTES (8<<10)
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 extern inline zap_leaf_phys_t *zap_leaf_phys(zap_leaf_t *l);
57 
58 static void
zap_memset(void * a,int c,size_t n)59 zap_memset(void *a, int c, size_t n)
60 {
61           char *cp = a;
62           char *cpend = cp + n;
63 
64           while (cp < cpend)
65                     *cp++ = c;
66 }
67 
68 static void
stv(int len,void * addr,uint64_t value)69 stv(int len, void *addr, uint64_t value)
70 {
71           switch (len) {
72           case 1:
73                     *(uint8_t *)addr = value;
74                     return;
75           case 2:
76                     *(uint16_t *)addr = value;
77                     return;
78           case 4:
79                     *(uint32_t *)addr = value;
80                     return;
81           case 8:
82                     *(uint64_t *)addr = value;
83                     return;
84           }
85           ASSERT(!"bad int len");
86 }
87 
88 static uint64_t
ldv(int len,const void * addr)89 ldv(int len, const void *addr)
90 {
91           switch (len) {
92           case 1:
93                     return (*(uint8_t *)addr);
94           case 2:
95                     return (*(uint16_t *)addr);
96           case 4:
97                     return (*(uint32_t *)addr);
98           case 8:
99                     return (*(uint64_t *)addr);
100           }
101           ASSERT(!"bad int len");
102           return (0xFEEDFACEDEADBEEFULL);
103 }
104 
105 void
zap_leaf_byteswap(zap_leaf_phys_t * buf,int size)106 zap_leaf_byteswap(zap_leaf_phys_t *buf, int size)
107 {
108           int i;
109           zap_leaf_t l;
110           dmu_buf_t l_dbuf;
111 
112           l_dbuf.db_data = buf;
113           l.l_bs = highbit64(size) - 1;
114           l.l_dbuf = &l_dbuf;
115 
116           buf->l_hdr.lh_block_type =    BSWAP_64(buf->l_hdr.lh_block_type);
117           buf->l_hdr.lh_prefix =                  BSWAP_64(buf->l_hdr.lh_prefix);
118           buf->l_hdr.lh_magic =                   BSWAP_32(buf->l_hdr.lh_magic);
119           buf->l_hdr.lh_nfree =                   BSWAP_16(buf->l_hdr.lh_nfree);
120           buf->l_hdr.lh_nentries =      BSWAP_16(buf->l_hdr.lh_nentries);
121           buf->l_hdr.lh_prefix_len =    BSWAP_16(buf->l_hdr.lh_prefix_len);
122           buf->l_hdr.lh_freelist =      BSWAP_16(buf->l_hdr.lh_freelist);
123 
124           for (i = 0; i < ZAP_LEAF_HASH_NUMENTRIES(&l); i++)
125                     buf->l_hash[i] = BSWAP_16(buf->l_hash[i]);
126 
127           for (i = 0; i < ZAP_LEAF_NUMCHUNKS(&l); i++) {
128                     zap_leaf_chunk_t *lc = &ZAP_LEAF_CHUNK(&l, i);
129                     struct zap_leaf_entry *le;
130 
131                     switch (lc->l_free.lf_type) {
132                     case ZAP_CHUNK_ENTRY:
133                               le = &lc->l_entry;
134 
135                               le->le_type =                 BSWAP_8(le->le_type);
136                               le->le_value_intlen =         BSWAP_8(le->le_value_intlen);
137                               le->le_next =                 BSWAP_16(le->le_next);
138                               le->le_name_chunk = BSWAP_16(le->le_name_chunk);
139                               le->le_name_numints =         BSWAP_16(le->le_name_numints);
140                               le->le_value_chunk =          BSWAP_16(le->le_value_chunk);
141                               le->le_value_numints =        BSWAP_16(le->le_value_numints);
142                               le->le_cd =                   BSWAP_32(le->le_cd);
143                               le->le_hash =                 BSWAP_64(le->le_hash);
144                               break;
145                     case ZAP_CHUNK_FREE:
146                               lc->l_free.lf_type =          BSWAP_8(lc->l_free.lf_type);
147                               lc->l_free.lf_next =          BSWAP_16(lc->l_free.lf_next);
148                               break;
149                     case ZAP_CHUNK_ARRAY:
150                               lc->l_array.la_type =         BSWAP_8(lc->l_array.la_type);
151                               lc->l_array.la_next =         BSWAP_16(lc->l_array.la_next);
152                               /* la_array doesn't need swapping */
153                               break;
154                     default:
155                               ASSERT(!"bad leaf type");
156                     }
157           }
158 }
159 
160 void
zap_leaf_init(zap_leaf_t * l,boolean_t sort)161 zap_leaf_init(zap_leaf_t *l, boolean_t sort)
162 {
163           int i;
164 
165           l->l_bs = highbit64(l->l_dbuf->db_size) - 1;
166           zap_memset(&zap_leaf_phys(l)->l_hdr, 0,
167               sizeof (struct zap_leaf_header));
168           zap_memset(zap_leaf_phys(l)->l_hash, CHAIN_END,
169               2*ZAP_LEAF_HASH_NUMENTRIES(l));
170           for (i = 0; i < ZAP_LEAF_NUMCHUNKS(l); i++) {
171                     ZAP_LEAF_CHUNK(l, i).l_free.lf_type = ZAP_CHUNK_FREE;
172                     ZAP_LEAF_CHUNK(l, i).l_free.lf_next = i+1;
173           }
174           ZAP_LEAF_CHUNK(l, ZAP_LEAF_NUMCHUNKS(l)-1).l_free.lf_next = CHAIN_END;
175           zap_leaf_phys(l)->l_hdr.lh_block_type = ZBT_LEAF;
176           zap_leaf_phys(l)->l_hdr.lh_magic = ZAP_LEAF_MAGIC;
177           zap_leaf_phys(l)->l_hdr.lh_nfree = ZAP_LEAF_NUMCHUNKS(l);
178           if (sort)
179                     zap_leaf_phys(l)->l_hdr.lh_flags |= ZLF_ENTRIES_CDSORTED;
180 }
181 
182 /*
183  * Routines which manipulate leaf chunks (l_chunk[]).
184  */
185 
186 static uint16_t
zap_leaf_chunk_alloc(zap_leaf_t * l)187 zap_leaf_chunk_alloc(zap_leaf_t *l)
188 {
189           int chunk;
190 
191           ASSERT(zap_leaf_phys(l)->l_hdr.lh_nfree > 0);
192 
193           chunk = zap_leaf_phys(l)->l_hdr.lh_freelist;
194           ASSERT3U(chunk, <, ZAP_LEAF_NUMCHUNKS(l));
195           ASSERT3U(ZAP_LEAF_CHUNK(l, chunk).l_free.lf_type, ==, ZAP_CHUNK_FREE);
196 
197           zap_leaf_phys(l)->l_hdr.lh_freelist =
198               ZAP_LEAF_CHUNK(l, chunk).l_free.lf_next;
199 
200           zap_leaf_phys(l)->l_hdr.lh_nfree--;
201 
202           return (chunk);
203 }
204 
205 static void
zap_leaf_chunk_free(zap_leaf_t * l,uint16_t chunk)206 zap_leaf_chunk_free(zap_leaf_t *l, uint16_t chunk)
207 {
208           struct zap_leaf_free *zlf = &ZAP_LEAF_CHUNK(l, chunk).l_free;
209           ASSERT3U(zap_leaf_phys(l)->l_hdr.lh_nfree, <, ZAP_LEAF_NUMCHUNKS(l));
210           ASSERT3U(chunk, <, ZAP_LEAF_NUMCHUNKS(l));
211           ASSERT(zlf->lf_type != ZAP_CHUNK_FREE);
212 
213           zlf->lf_type = ZAP_CHUNK_FREE;
214           zlf->lf_next = zap_leaf_phys(l)->l_hdr.lh_freelist;
215           bzero(zlf->lf_pad, sizeof (zlf->lf_pad)); /* help it to compress */
216           zap_leaf_phys(l)->l_hdr.lh_freelist = chunk;
217 
218           zap_leaf_phys(l)->l_hdr.lh_nfree++;
219 }
220 
221 /*
222  * Routines which manipulate leaf arrays (zap_leaf_array type chunks).
223  */
224 
225 static uint16_t
zap_leaf_array_create(zap_leaf_t * l,const char * buf,int integer_size,int num_integers)226 zap_leaf_array_create(zap_leaf_t *l, const char *buf,
227     int integer_size, int num_integers)
228 {
229           uint16_t chunk_head;
230           uint16_t *chunkp = &chunk_head;
231           int byten = 0;
232           uint64_t value = 0;
233           int shift = (integer_size-1)*8;
234           int len = num_integers;
235 
236           ASSERT3U(num_integers * integer_size, <, MAX_ARRAY_BYTES);
237 
238           while (len > 0) {
239                     uint16_t chunk = zap_leaf_chunk_alloc(l);
240                     struct zap_leaf_array *la = &ZAP_LEAF_CHUNK(l, chunk).l_array;
241                     int i;
242 
243                     la->la_type = ZAP_CHUNK_ARRAY;
244                     for (i = 0; i < ZAP_LEAF_ARRAY_BYTES; i++) {
245                               if (byten == 0)
246                                         value = ldv(integer_size, buf);
247                               la->la_array[i] = value >> shift;
248                               value <<= 8;
249                               if (++byten == integer_size) {
250                                         byten = 0;
251                                         buf += integer_size;
252                                         if (--len == 0)
253                                                   break;
254                               }
255                     }
256 
257                     *chunkp = chunk;
258                     chunkp = &la->la_next;
259           }
260           *chunkp = CHAIN_END;
261 
262           return (chunk_head);
263 }
264 
265 static void
zap_leaf_array_free(zap_leaf_t * l,uint16_t * chunkp)266 zap_leaf_array_free(zap_leaf_t *l, uint16_t *chunkp)
267 {
268           uint16_t chunk = *chunkp;
269 
270           *chunkp = CHAIN_END;
271 
272           while (chunk != CHAIN_END) {
273                     int nextchunk = ZAP_LEAF_CHUNK(l, chunk).l_array.la_next;
274                     ASSERT3U(ZAP_LEAF_CHUNK(l, chunk).l_array.la_type, ==,
275                         ZAP_CHUNK_ARRAY);
276                     zap_leaf_chunk_free(l, chunk);
277                     chunk = nextchunk;
278           }
279 }
280 
281 /* array_len and buf_len are in integers, not bytes */
282 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)283 zap_leaf_array_read(zap_leaf_t *l, uint16_t chunk,
284     int array_int_len, int array_len, int buf_int_len, uint64_t buf_len,
285     void *buf)
286 {
287           int len = MIN(array_len, buf_len);
288           int byten = 0;
289           uint64_t value = 0;
290           char *p = buf;
291 
292           ASSERT3U(array_int_len, <=, buf_int_len);
293 
294           /* Fast path for one 8-byte integer */
295           if (array_int_len == 8 && buf_int_len == 8 && len == 1) {
296                     struct zap_leaf_array *la = &ZAP_LEAF_CHUNK(l, chunk).l_array;
297                     uint8_t *ip = la->la_array;
298                     uint64_t *buf64 = buf;
299 
300                     *buf64 = (uint64_t)ip[0] << 56 | (uint64_t)ip[1] << 48 |
301                         (uint64_t)ip[2] << 40 | (uint64_t)ip[3] << 32 |
302                         (uint64_t)ip[4] << 24 | (uint64_t)ip[5] << 16 |
303                         (uint64_t)ip[6] << 8 | (uint64_t)ip[7];
304                     return;
305           }
306 
307           /* Fast path for an array of 1-byte integers (eg. the entry name) */
308           if (array_int_len == 1 && buf_int_len == 1 &&
309               buf_len > array_len + ZAP_LEAF_ARRAY_BYTES) {
310                     while (chunk != CHAIN_END) {
311                               struct zap_leaf_array *la =
312                                   &ZAP_LEAF_CHUNK(l, chunk).l_array;
313                               bcopy(la->la_array, p, ZAP_LEAF_ARRAY_BYTES);
314                               p += ZAP_LEAF_ARRAY_BYTES;
315                               chunk = la->la_next;
316                     }
317                     return;
318           }
319 
320           while (len > 0) {
321                     struct zap_leaf_array *la = &ZAP_LEAF_CHUNK(l, chunk).l_array;
322                     int i;
323 
324                     ASSERT3U(chunk, <, ZAP_LEAF_NUMCHUNKS(l));
325                     for (i = 0; i < ZAP_LEAF_ARRAY_BYTES && len > 0; i++) {
326                               value = (value << 8) | la->la_array[i];
327                               byten++;
328                               if (byten == array_int_len) {
329                                         stv(buf_int_len, p, value);
330                                         byten = 0;
331                                         len--;
332                                         if (len == 0)
333                                                   return;
334                                         p += buf_int_len;
335                               }
336                     }
337                     chunk = la->la_next;
338           }
339 }
340 
341 static boolean_t
zap_leaf_array_match(zap_leaf_t * l,zap_name_t * zn,int chunk,int array_numints)342 zap_leaf_array_match(zap_leaf_t *l, zap_name_t *zn,
343     int chunk, int array_numints)
344 {
345           int bseen = 0;
346 
347           if (zap_getflags(zn->zn_zap) & ZAP_FLAG_UINT64_KEY) {
348                     uint64_t *thiskey;
349                     boolean_t match;
350 
351                     ASSERT(zn->zn_key_intlen == sizeof (*thiskey));
352                     thiskey = kmem_alloc(array_numints * sizeof (*thiskey),
353                         KM_SLEEP);
354 
355                     zap_leaf_array_read(l, chunk, sizeof (*thiskey), array_numints,
356                         sizeof (*thiskey), array_numints, thiskey);
357                     match = bcmp(thiskey, zn->zn_key_orig,
358                         array_numints * sizeof (*thiskey)) == 0;
359                     kmem_free(thiskey, array_numints * sizeof (*thiskey));
360                     return (match);
361           }
362 
363           ASSERT(zn->zn_key_intlen == 1);
364           if (zn->zn_matchtype == MT_FIRST) {
365                     char *thisname = kmem_alloc(array_numints, KM_SLEEP);
366                     boolean_t match;
367 
368                     zap_leaf_array_read(l, chunk, sizeof (char), array_numints,
369                         sizeof (char), array_numints, thisname);
370                     match = zap_match(zn, thisname);
371                     kmem_free(thisname, array_numints);
372                     return (match);
373           }
374 
375           /*
376            * Fast path for exact matching.
377            * First check that the lengths match, so that we don't read
378            * past the end of the zn_key_orig array.
379            */
380           if (array_numints != zn->zn_key_orig_numints)
381                     return (B_FALSE);
382           while (bseen < array_numints) {
383                     struct zap_leaf_array *la = &ZAP_LEAF_CHUNK(l, chunk).l_array;
384                     int toread = MIN(array_numints - bseen, ZAP_LEAF_ARRAY_BYTES);
385                     ASSERT3U(chunk, <, ZAP_LEAF_NUMCHUNKS(l));
386                     if (bcmp(la->la_array, (char *)zn->zn_key_orig + bseen, toread))
387                               break;
388                     chunk = la->la_next;
389                     bseen += toread;
390           }
391           return (bseen == array_numints);
392 }
393 
394 /*
395  * Routines which manipulate leaf entries.
396  */
397 
398 int
zap_leaf_lookup(zap_leaf_t * l,zap_name_t * zn,zap_entry_handle_t * zeh)399 zap_leaf_lookup(zap_leaf_t *l, zap_name_t *zn, zap_entry_handle_t *zeh)
400 {
401           uint16_t *chunkp;
402           struct zap_leaf_entry *le;
403 
404           ASSERT3U(zap_leaf_phys(l)->l_hdr.lh_magic, ==, ZAP_LEAF_MAGIC);
405 
406 again:
407           for (chunkp = LEAF_HASH_ENTPTR(l, zn->zn_hash);
408               *chunkp != CHAIN_END; chunkp = &le->le_next) {
409                     uint16_t chunk = *chunkp;
410                     le = ZAP_LEAF_ENTRY(l, chunk);
411 
412                     ASSERT3U(chunk, <, ZAP_LEAF_NUMCHUNKS(l));
413                     ASSERT3U(le->le_type, ==, ZAP_CHUNK_ENTRY);
414 
415                     if (le->le_hash != zn->zn_hash)
416                               continue;
417 
418                     /*
419                      * NB: the entry chain is always sorted by cd on
420                      * normalized zap objects, so this will find the
421                      * lowest-cd match for MT_FIRST.
422                      */
423                     ASSERT(zn->zn_matchtype == MT_EXACT ||
424                         (zap_leaf_phys(l)->l_hdr.lh_flags & ZLF_ENTRIES_CDSORTED));
425                     if (zap_leaf_array_match(l, zn, le->le_name_chunk,
426                         le->le_name_numints)) {
427                               zeh->zeh_num_integers = le->le_value_numints;
428                               zeh->zeh_integer_size = le->le_value_intlen;
429                               zeh->zeh_cd = le->le_cd;
430                               zeh->zeh_hash = le->le_hash;
431                               zeh->zeh_chunkp = chunkp;
432                               zeh->zeh_leaf = l;
433                               return (0);
434                     }
435           }
436 
437           /*
438            * NB: we could of course do this in one pass, but that would be
439            * a pain.  We'll see if MT_BEST is even used much.
440            */
441           if (zn->zn_matchtype == MT_BEST) {
442                     zn->zn_matchtype = MT_FIRST;
443                     goto again;
444           }
445 
446           return (SET_ERROR(ENOENT));
447 }
448 
449 /* Return (h1,cd1 >= h2,cd2) */
450 #define   HCD_GTEQ(h1, cd1, h2, cd2) \
451           ((h1 > h2) ? TRUE : ((h1 == h2 && cd1 >= cd2) ? TRUE : FALSE))
452 
453 int
zap_leaf_lookup_closest(zap_leaf_t * l,uint64_t h,uint32_t cd,zap_entry_handle_t * zeh)454 zap_leaf_lookup_closest(zap_leaf_t *l,
455     uint64_t h, uint32_t cd, zap_entry_handle_t *zeh)
456 {
457           uint16_t chunk;
458           uint64_t besth = -1ULL;
459           uint32_t bestcd = -1U;
460           uint16_t bestlh = ZAP_LEAF_HASH_NUMENTRIES(l)-1;
461           uint16_t lh;
462           struct zap_leaf_entry *le;
463 
464           ASSERT3U(zap_leaf_phys(l)->l_hdr.lh_magic, ==, ZAP_LEAF_MAGIC);
465 
466           for (lh = LEAF_HASH(l, h); lh <= bestlh; lh++) {
467                     for (chunk = zap_leaf_phys(l)->l_hash[lh];
468                         chunk != CHAIN_END; chunk = le->le_next) {
469                               le = ZAP_LEAF_ENTRY(l, chunk);
470 
471                               ASSERT3U(chunk, <, ZAP_LEAF_NUMCHUNKS(l));
472                               ASSERT3U(le->le_type, ==, ZAP_CHUNK_ENTRY);
473 
474                               if (HCD_GTEQ(le->le_hash, le->le_cd, h, cd) &&
475                                   HCD_GTEQ(besth, bestcd, le->le_hash, le->le_cd)) {
476                                         ASSERT3U(bestlh, >=, lh);
477                                         bestlh = lh;
478                                         besth = le->le_hash;
479                                         bestcd = le->le_cd;
480 
481                                         zeh->zeh_num_integers = le->le_value_numints;
482                                         zeh->zeh_integer_size = le->le_value_intlen;
483                                         zeh->zeh_cd = le->le_cd;
484                                         zeh->zeh_hash = le->le_hash;
485                                         zeh->zeh_fakechunk = chunk;
486                                         zeh->zeh_chunkp = &zeh->zeh_fakechunk;
487                                         zeh->zeh_leaf = l;
488                               }
489                     }
490           }
491 
492           return (bestcd == -1U ? ENOENT : 0);
493 }
494 
495 int
zap_entry_read(const zap_entry_handle_t * zeh,uint8_t integer_size,uint64_t num_integers,void * buf)496 zap_entry_read(const zap_entry_handle_t *zeh,
497     uint8_t integer_size, uint64_t num_integers, void *buf)
498 {
499           struct zap_leaf_entry *le =
500               ZAP_LEAF_ENTRY(zeh->zeh_leaf, *zeh->zeh_chunkp);
501           ASSERT3U(le->le_type, ==, ZAP_CHUNK_ENTRY);
502 
503           if (le->le_value_intlen > integer_size)
504                     return (SET_ERROR(EINVAL));
505 
506           zap_leaf_array_read(zeh->zeh_leaf, le->le_value_chunk,
507               le->le_value_intlen, le->le_value_numints,
508               integer_size, num_integers, buf);
509 
510           if (zeh->zeh_num_integers > num_integers)
511                     return (SET_ERROR(EOVERFLOW));
512           return (0);
513 
514 }
515 
516 int
zap_entry_read_name(zap_t * zap,const zap_entry_handle_t * zeh,uint16_t buflen,char * buf)517 zap_entry_read_name(zap_t *zap, const zap_entry_handle_t *zeh, uint16_t buflen,
518     char *buf)
519 {
520           struct zap_leaf_entry *le =
521               ZAP_LEAF_ENTRY(zeh->zeh_leaf, *zeh->zeh_chunkp);
522           ASSERT3U(le->le_type, ==, ZAP_CHUNK_ENTRY);
523 
524           if (zap_getflags(zap) & ZAP_FLAG_UINT64_KEY) {
525                     zap_leaf_array_read(zeh->zeh_leaf, le->le_name_chunk, 8,
526                         le->le_name_numints, 8, buflen / 8, buf);
527           } else {
528                     zap_leaf_array_read(zeh->zeh_leaf, le->le_name_chunk, 1,
529                         le->le_name_numints, 1, buflen, buf);
530           }
531           if (le->le_name_numints > buflen)
532                     return (SET_ERROR(EOVERFLOW));
533           return (0);
534 }
535 
536 int
zap_entry_update(zap_entry_handle_t * zeh,uint8_t integer_size,uint64_t num_integers,const void * buf)537 zap_entry_update(zap_entry_handle_t *zeh,
538     uint8_t integer_size, uint64_t num_integers, const void *buf)
539 {
540           int delta_chunks;
541           zap_leaf_t *l = zeh->zeh_leaf;
542           struct zap_leaf_entry *le = ZAP_LEAF_ENTRY(l, *zeh->zeh_chunkp);
543 
544           delta_chunks = ZAP_LEAF_ARRAY_NCHUNKS(num_integers * integer_size) -
545               ZAP_LEAF_ARRAY_NCHUNKS(le->le_value_numints * le->le_value_intlen);
546 
547           if ((int)zap_leaf_phys(l)->l_hdr.lh_nfree < delta_chunks)
548                     return (SET_ERROR(EAGAIN));
549 
550           zap_leaf_array_free(l, &le->le_value_chunk);
551           le->le_value_chunk =
552               zap_leaf_array_create(l, buf, integer_size, num_integers);
553           le->le_value_numints = num_integers;
554           le->le_value_intlen = integer_size;
555           return (0);
556 }
557 
558 void
zap_entry_remove(zap_entry_handle_t * zeh)559 zap_entry_remove(zap_entry_handle_t *zeh)
560 {
561           uint16_t entry_chunk;
562           struct zap_leaf_entry *le;
563           zap_leaf_t *l = zeh->zeh_leaf;
564 
565           ASSERT3P(zeh->zeh_chunkp, !=, &zeh->zeh_fakechunk);
566 
567           entry_chunk = *zeh->zeh_chunkp;
568           le = ZAP_LEAF_ENTRY(l, entry_chunk);
569           ASSERT3U(le->le_type, ==, ZAP_CHUNK_ENTRY);
570 
571           zap_leaf_array_free(l, &le->le_name_chunk);
572           zap_leaf_array_free(l, &le->le_value_chunk);
573 
574           *zeh->zeh_chunkp = le->le_next;
575           zap_leaf_chunk_free(l, entry_chunk);
576 
577           zap_leaf_phys(l)->l_hdr.lh_nentries--;
578 }
579 
580 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)581 zap_entry_create(zap_leaf_t *l, zap_name_t *zn, uint32_t cd,
582     uint8_t integer_size, uint64_t num_integers, const void *buf,
583     zap_entry_handle_t *zeh)
584 {
585           uint16_t chunk;
586           uint16_t *chunkp;
587           struct zap_leaf_entry *le;
588           uint64_t valuelen;
589           int numchunks;
590           uint64_t h = zn->zn_hash;
591 
592           valuelen = integer_size * num_integers;
593 
594           numchunks = 1 + ZAP_LEAF_ARRAY_NCHUNKS(zn->zn_key_orig_numints *
595               zn->zn_key_intlen) + ZAP_LEAF_ARRAY_NCHUNKS(valuelen);
596           if (numchunks > ZAP_LEAF_NUMCHUNKS(l))
597                     return (E2BIG);
598 
599           if (cd == ZAP_NEED_CD) {
600                     /* find the lowest unused cd */
601                     if (zap_leaf_phys(l)->l_hdr.lh_flags & ZLF_ENTRIES_CDSORTED) {
602                               cd = 0;
603 
604                               for (chunk = *LEAF_HASH_ENTPTR(l, h);
605                                   chunk != CHAIN_END; chunk = le->le_next) {
606                                         le = ZAP_LEAF_ENTRY(l, chunk);
607                                         if (le->le_cd > cd)
608                                                   break;
609                                         if (le->le_hash == h) {
610                                                   ASSERT3U(cd, ==, le->le_cd);
611                                                   cd++;
612                                         }
613                               }
614                     } else {
615                               /* old unsorted format; do it the O(n^2) way */
616                               for (cd = 0; ; cd++) {
617                                         for (chunk = *LEAF_HASH_ENTPTR(l, h);
618                                             chunk != CHAIN_END; chunk = le->le_next) {
619                                                   le = ZAP_LEAF_ENTRY(l, chunk);
620                                                   if (le->le_hash == h &&
621                                                       le->le_cd == cd) {
622                                                             break;
623                                                   }
624                                         }
625                                         /* If this cd is not in use, we are good. */
626                                         if (chunk == CHAIN_END)
627                                                   break;
628                               }
629                     }
630                     /*
631                      * We would run out of space in a block before we could
632                      * store enough entries to run out of CD values.
633                      */
634                     ASSERT3U(cd, <, zap_maxcd(zn->zn_zap));
635           }
636 
637           if (zap_leaf_phys(l)->l_hdr.lh_nfree < numchunks)
638                     return (SET_ERROR(EAGAIN));
639 
640           /* make the entry */
641           chunk = zap_leaf_chunk_alloc(l);
642           le = ZAP_LEAF_ENTRY(l, chunk);
643           le->le_type = ZAP_CHUNK_ENTRY;
644           le->le_name_chunk = zap_leaf_array_create(l, zn->zn_key_orig,
645               zn->zn_key_intlen, zn->zn_key_orig_numints);
646           le->le_name_numints = zn->zn_key_orig_numints;
647           le->le_value_chunk =
648               zap_leaf_array_create(l, buf, integer_size, num_integers);
649           le->le_value_numints = num_integers;
650           le->le_value_intlen = integer_size;
651           le->le_hash = h;
652           le->le_cd = cd;
653 
654           /* link it into the hash chain */
655           /* XXX if we did the search above, we could just use that */
656           chunkp = zap_leaf_rehash_entry(l, chunk);
657 
658           zap_leaf_phys(l)->l_hdr.lh_nentries++;
659 
660           zeh->zeh_leaf = l;
661           zeh->zeh_num_integers = num_integers;
662           zeh->zeh_integer_size = le->le_value_intlen;
663           zeh->zeh_cd = le->le_cd;
664           zeh->zeh_hash = le->le_hash;
665           zeh->zeh_chunkp = chunkp;
666 
667           return (0);
668 }
669 
670 /*
671  * Determine if there is another entry with the same normalized form.
672  * For performance purposes, either zn or name must be provided (the
673  * other can be NULL).  Note, there usually won't be any hash
674  * conflicts, in which case we don't need the concatenated/normalized
675  * form of the name.  But all callers have one of these on hand anyway,
676  * so might as well take advantage.  A cleaner but slower interface
677  * would accept neither argument, and compute the normalized name as
678  * needed (using zap_name_alloc(zap_entry_read_name(zeh))).
679  */
680 boolean_t
zap_entry_normalization_conflict(zap_entry_handle_t * zeh,zap_name_t * zn,const char * name,zap_t * zap)681 zap_entry_normalization_conflict(zap_entry_handle_t *zeh, zap_name_t *zn,
682     const char *name, zap_t *zap)
683 {
684           uint64_t chunk;
685           struct zap_leaf_entry *le;
686           boolean_t allocdzn = B_FALSE;
687 
688           if (zap->zap_normflags == 0)
689                     return (B_FALSE);
690 
691           for (chunk = *LEAF_HASH_ENTPTR(zeh->zeh_leaf, zeh->zeh_hash);
692               chunk != CHAIN_END; chunk = le->le_next) {
693                     le = ZAP_LEAF_ENTRY(zeh->zeh_leaf, chunk);
694                     if (le->le_hash != zeh->zeh_hash)
695                               continue;
696                     if (le->le_cd == zeh->zeh_cd)
697                               continue;
698 
699                     if (zn == NULL) {
700                               zn = zap_name_alloc(zap, name, MT_FIRST);
701                               allocdzn = B_TRUE;
702                     }
703                     if (zap_leaf_array_match(zeh->zeh_leaf, zn,
704                         le->le_name_chunk, le->le_name_numints)) {
705                               if (allocdzn)
706                                         zap_name_free(zn);
707                               return (B_TRUE);
708                     }
709           }
710           if (allocdzn)
711                     zap_name_free(zn);
712           return (B_FALSE);
713 }
714 
715 /*
716  * Routines for transferring entries between leafs.
717  */
718 
719 static uint16_t *
zap_leaf_rehash_entry(zap_leaf_t * l,uint16_t entry)720 zap_leaf_rehash_entry(zap_leaf_t *l, uint16_t entry)
721 {
722           struct zap_leaf_entry *le = ZAP_LEAF_ENTRY(l, entry);
723           struct zap_leaf_entry *le2;
724           uint16_t *chunkp;
725 
726           /*
727            * keep the entry chain sorted by cd
728            * NB: this will not cause problems for unsorted leafs, though
729            * it is unnecessary there.
730            */
731           for (chunkp = LEAF_HASH_ENTPTR(l, le->le_hash);
732               *chunkp != CHAIN_END; chunkp = &le2->le_next) {
733                     le2 = ZAP_LEAF_ENTRY(l, *chunkp);
734                     if (le2->le_cd > le->le_cd)
735                               break;
736           }
737 
738           le->le_next = *chunkp;
739           *chunkp = entry;
740           return (chunkp);
741 }
742 
743 static uint16_t
zap_leaf_transfer_array(zap_leaf_t * l,uint16_t chunk,zap_leaf_t * nl)744 zap_leaf_transfer_array(zap_leaf_t *l, uint16_t chunk, zap_leaf_t *nl)
745 {
746           uint16_t new_chunk;
747           uint16_t *nchunkp = &new_chunk;
748 
749           while (chunk != CHAIN_END) {
750                     uint16_t nchunk = zap_leaf_chunk_alloc(nl);
751                     struct zap_leaf_array *nla =
752                         &ZAP_LEAF_CHUNK(nl, nchunk).l_array;
753                     struct zap_leaf_array *la =
754                         &ZAP_LEAF_CHUNK(l, chunk).l_array;
755                     int nextchunk = la->la_next;
756 
757                     ASSERT3U(chunk, <, ZAP_LEAF_NUMCHUNKS(l));
758                     ASSERT3U(nchunk, <, ZAP_LEAF_NUMCHUNKS(l));
759 
760                     *nla = *la; /* structure assignment */
761 
762                     zap_leaf_chunk_free(l, chunk);
763                     chunk = nextchunk;
764                     *nchunkp = nchunk;
765                     nchunkp = &nla->la_next;
766           }
767           *nchunkp = CHAIN_END;
768           return (new_chunk);
769 }
770 
771 static void
zap_leaf_transfer_entry(zap_leaf_t * l,int entry,zap_leaf_t * nl)772 zap_leaf_transfer_entry(zap_leaf_t *l, int entry, zap_leaf_t *nl)
773 {
774           struct zap_leaf_entry *le, *nle;
775           uint16_t chunk;
776 
777           le = ZAP_LEAF_ENTRY(l, entry);
778           ASSERT3U(le->le_type, ==, ZAP_CHUNK_ENTRY);
779 
780           chunk = zap_leaf_chunk_alloc(nl);
781           nle = ZAP_LEAF_ENTRY(nl, chunk);
782           *nle = *le; /* structure assignment */
783 
784           (void) zap_leaf_rehash_entry(nl, chunk);
785 
786           nle->le_name_chunk = zap_leaf_transfer_array(l, le->le_name_chunk, nl);
787           nle->le_value_chunk =
788               zap_leaf_transfer_array(l, le->le_value_chunk, nl);
789 
790           zap_leaf_chunk_free(l, entry);
791 
792           zap_leaf_phys(l)->l_hdr.lh_nentries--;
793           zap_leaf_phys(nl)->l_hdr.lh_nentries++;
794 }
795 
796 /*
797  * Transfer the entries whose hash prefix ends in 1 to the new leaf.
798  */
799 void
zap_leaf_split(zap_leaf_t * l,zap_leaf_t * nl,boolean_t sort)800 zap_leaf_split(zap_leaf_t *l, zap_leaf_t *nl, boolean_t sort)
801 {
802           int i;
803           int bit = 64 - 1 - zap_leaf_phys(l)->l_hdr.lh_prefix_len;
804 
805           /* set new prefix and prefix_len */
806           zap_leaf_phys(l)->l_hdr.lh_prefix <<= 1;
807           zap_leaf_phys(l)->l_hdr.lh_prefix_len++;
808           zap_leaf_phys(nl)->l_hdr.lh_prefix =
809               zap_leaf_phys(l)->l_hdr.lh_prefix | 1;
810           zap_leaf_phys(nl)->l_hdr.lh_prefix_len =
811               zap_leaf_phys(l)->l_hdr.lh_prefix_len;
812 
813           /* break existing hash chains */
814           zap_memset(zap_leaf_phys(l)->l_hash, CHAIN_END,
815               2*ZAP_LEAF_HASH_NUMENTRIES(l));
816 
817           if (sort)
818                     zap_leaf_phys(l)->l_hdr.lh_flags |= ZLF_ENTRIES_CDSORTED;
819 
820           /*
821            * Transfer entries whose hash bit 'bit' is set to nl; rehash
822            * the remaining entries
823            *
824            * NB: We could find entries via the hashtable instead. That
825            * would be O(hashents+numents) rather than O(numblks+numents),
826            * but this accesses memory more sequentially, and when we're
827            * called, the block is usually pretty full.
828            */
829           for (i = 0; i < ZAP_LEAF_NUMCHUNKS(l); i++) {
830                     struct zap_leaf_entry *le = ZAP_LEAF_ENTRY(l, i);
831                     if (le->le_type != ZAP_CHUNK_ENTRY)
832                               continue;
833 
834                     if (le->le_hash & (1ULL << bit))
835                               zap_leaf_transfer_entry(l, i, nl);
836                     else
837                               (void) zap_leaf_rehash_entry(l, i);
838           }
839 }
840 
841 void
zap_leaf_stats(zap_t * zap,zap_leaf_t * l,zap_stats_t * zs)842 zap_leaf_stats(zap_t *zap, zap_leaf_t *l, zap_stats_t *zs)
843 {
844           int i, n;
845 
846           n = zap_f_phys(zap)->zap_ptrtbl.zt_shift -
847               zap_leaf_phys(l)->l_hdr.lh_prefix_len;
848           n = MIN(n, ZAP_HISTOGRAM_SIZE-1);
849           zs->zs_leafs_with_2n_pointers[n]++;
850 
851 
852           n = zap_leaf_phys(l)->l_hdr.lh_nentries/5;
853           n = MIN(n, ZAP_HISTOGRAM_SIZE-1);
854           zs->zs_blocks_with_n5_entries[n]++;
855 
856           n = ((1<<FZAP_BLOCK_SHIFT(zap)) -
857               zap_leaf_phys(l)->l_hdr.lh_nfree * (ZAP_LEAF_ARRAY_BYTES+1))*10 /
858               (1<<FZAP_BLOCK_SHIFT(zap));
859           n = MIN(n, ZAP_HISTOGRAM_SIZE-1);
860           zs->zs_blocks_n_tenths_full[n]++;
861 
862           for (i = 0; i < ZAP_LEAF_HASH_NUMENTRIES(l); i++) {
863                     int nentries = 0;
864                     int chunk = zap_leaf_phys(l)->l_hash[i];
865 
866                     while (chunk != CHAIN_END) {
867                               struct zap_leaf_entry *le =
868                                   ZAP_LEAF_ENTRY(l, chunk);
869 
870                               n = 1 + ZAP_LEAF_ARRAY_NCHUNKS(le->le_name_numints) +
871                                   ZAP_LEAF_ARRAY_NCHUNKS(le->le_value_numints *
872                                   le->le_value_intlen);
873                               n = MIN(n, ZAP_HISTOGRAM_SIZE-1);
874                               zs->zs_entries_using_n_chunks[n]++;
875 
876                               chunk = le->le_next;
877                               nentries++;
878                     }
879 
880                     n = nentries;
881                     n = MIN(n, ZAP_HISTOGRAM_SIZE-1);
882                     zs->zs_buckets_with_n_entries[n]++;
883           }
884 }
885