xref: /illumos-gate/usr/src/uts/common/fs/zfs/zap.c (revision 52abb70e)
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) 2012, 2018 by Delphix. All rights reserved.
24  * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved.
25  */
26 
27 /*
28  * This file contains the top half of the zfs directory structure
29  * implementation. The bottom half is in zap_leaf.c.
30  *
31  * The zdir is an extendable hash data structure. There is a table of
32  * pointers to buckets (zap_t->zd_data->zd_leafs). The buckets are
33  * each a constant size and hold a variable number of directory entries.
34  * The buckets (aka "leaf nodes") are implemented in zap_leaf.c.
35  *
36  * The pointer table holds a power of 2 number of pointers.
37  * (1<<zap_t->zd_data->zd_phys->zd_prefix_len).  The bucket pointed to
38  * by the pointer at index i in the table holds entries whose hash value
39  * has a zd_prefix_len - bit prefix
40  */
41 
42 #include <sys/spa.h>
43 #include <sys/dmu.h>
44 #include <sys/zfs_context.h>
45 #include <sys/zfs_znode.h>
46 #include <sys/fs/zfs.h>
47 #include <sys/zap.h>
48 #include <sys/refcount.h>
49 #include <sys/zap_impl.h>
50 #include <sys/zap_leaf.h>
51 
52 /*
53  * If zap_iterate_prefetch is set, we will prefetch the entire ZAP object
54  * (all leaf blocks) when we start iterating over it.
55  *
56  * For zap_cursor_init(), the callers all intend to iterate through all the
57  * entries.  There are a few cases where an error (typically i/o error) could
58  * cause it to bail out early.
59  *
60  * For zap_cursor_init_serialized(), there are callers that do the iteration
61  * outside of ZFS.  Typically they would iterate over everything, but we
62  * don't have control of that.  E.g. zfs_ioc_snapshot_list_next(),
63  * zcp_snapshots_iter(), and other iterators over things in the MOS - these
64  * are called by /sbin/zfs and channel programs.  The other example is
65  * zfs_readdir() which iterates over directory entries for the getdents()
66  * syscall.  /sbin/ls iterates to the end (unless it receives a signal), but
67  * userland doesn't have to.
68  *
69  * Given that the ZAP entries aren't returned in a specific order, the only
70  * legitimate use cases for partial iteration would be:
71  *
72  * 1. Pagination: e.g. you only want to display 100 entries at a time, so you
73  *    get the first 100 and then wait for the user to hit "next page", which
74  *    they may never do).
75  *
76  * 2. You want to know if there are more than X entries, without relying on
77  *    the zfs-specific implementation of the directory's st_size (which is
78  *    the number of entries).
79  */
80 boolean_t zap_iterate_prefetch = B_TRUE;
81 
82 int fzap_default_block_shift = 14; /* 16k blocksize */
83 
84 extern inline zap_phys_t *zap_f_phys(zap_t *zap);
85 
86 static uint64_t zap_allocate_blocks(zap_t *zap, int nblocks);
87 
88 void
fzap_byteswap(void * vbuf,size_t size)89 fzap_byteswap(void *vbuf, size_t size)
90 {
91 	uint64_t block_type = *(uint64_t *)vbuf;
92 
93 	if (block_type == ZBT_LEAF || block_type == BSWAP_64(ZBT_LEAF))
94 		zap_leaf_byteswap(vbuf, size);
95 	else {
96 		/* it's a ptrtbl block */
97 		byteswap_uint64_array(vbuf, size);
98 	}
99 }
100 
101 void
fzap_upgrade(zap_t * zap,dmu_tx_t * tx,zap_flags_t flags)102 fzap_upgrade(zap_t *zap, dmu_tx_t *tx, zap_flags_t flags)
103 {
104 	ASSERT(RW_WRITE_HELD(&zap->zap_rwlock));
105 	zap->zap_ismicro = FALSE;
106 
107 	zap->zap_dbu.dbu_evict_func_sync = zap_evict_sync;
108 	zap->zap_dbu.dbu_evict_func_async = NULL;
109 
110 	mutex_init(&zap->zap_f.zap_num_entries_mtx, 0, 0, 0);
111 	zap->zap_f.zap_block_shift = highbit64(zap->zap_dbuf->db_size) - 1;
112 
113 	zap_phys_t *zp = zap_f_phys(zap);
114 	/*
115 	 * explicitly zero it since it might be coming from an
116 	 * initialized microzap
117 	 */
118 	bzero(zap->zap_dbuf->db_data, zap->zap_dbuf->db_size);
119 	zp->zap_block_type = ZBT_HEADER;
120 	zp->zap_magic = ZAP_MAGIC;
121 
122 	zp->zap_ptrtbl.zt_shift = ZAP_EMBEDDED_PTRTBL_SHIFT(zap);
123 
124 	zp->zap_freeblk = 2;		/* block 1 will be the first leaf */
125 	zp->zap_num_leafs = 1;
126 	zp->zap_num_entries = 0;
127 	zp->zap_salt = zap->zap_salt;
128 	zp->zap_normflags = zap->zap_normflags;
129 	zp->zap_flags = flags;
130 
131 	/* block 1 will be the first leaf */
132 	for (int i = 0; i < (1<<zp->zap_ptrtbl.zt_shift); i++)
133 		ZAP_EMBEDDED_PTRTBL_ENT(zap, i) = 1;
134 
135 	/*
136 	 * set up block 1 - the first leaf
137 	 */
138 	dmu_buf_t *db;
139 	VERIFY0(dmu_buf_hold(zap->zap_objset, zap->zap_object,
140 	    1<<FZAP_BLOCK_SHIFT(zap), FTAG, &db, DMU_READ_NO_PREFETCH));
141 	dmu_buf_will_dirty(db, tx);
142 
143 	zap_leaf_t *l = kmem_zalloc(sizeof (zap_leaf_t), KM_SLEEP);
144 	l->l_dbuf = db;
145 
146 	zap_leaf_init(l, zp->zap_normflags != 0);
147 
148 	kmem_free(l, sizeof (zap_leaf_t));
149 	dmu_buf_rele(db, FTAG);
150 }
151 
152 static int
zap_tryupgradedir(zap_t * zap,dmu_tx_t * tx)153 zap_tryupgradedir(zap_t *zap, dmu_tx_t *tx)
154 {
155 	if (RW_WRITE_HELD(&zap->zap_rwlock))
156 		return (1);
157 	if (rw_tryupgrade(&zap->zap_rwlock)) {
158 		dmu_buf_will_dirty(zap->zap_dbuf, tx);
159 		return (1);
160 	}
161 	return (0);
162 }
163 
164 /*
165  * Generic routines for dealing with the pointer & cookie tables.
166  */
167 
168 static int
zap_table_grow(zap_t * zap,zap_table_phys_t * tbl,void (* transfer_func)(const uint64_t * src,uint64_t * dst,int n),dmu_tx_t * tx)169 zap_table_grow(zap_t *zap, zap_table_phys_t *tbl,
170     void (*transfer_func)(const uint64_t *src, uint64_t *dst, int n),
171     dmu_tx_t *tx)
172 {
173 	uint64_t newblk;
174 	int bs = FZAP_BLOCK_SHIFT(zap);
175 	int hepb = 1<<(bs-4);
176 	/* hepb = half the number of entries in a block */
177 
178 	ASSERT(RW_WRITE_HELD(&zap->zap_rwlock));
179 	ASSERT(tbl->zt_blk != 0);
180 	ASSERT(tbl->zt_numblks > 0);
181 
182 	if (tbl->zt_nextblk != 0) {
183 		newblk = tbl->zt_nextblk;
184 	} else {
185 		newblk = zap_allocate_blocks(zap, tbl->zt_numblks * 2);
186 		tbl->zt_nextblk = newblk;
187 		ASSERT0(tbl->zt_blks_copied);
188 		dmu_prefetch(zap->zap_objset, zap->zap_object, 0,
189 		    tbl->zt_blk << bs, tbl->zt_numblks << bs,
190 		    ZIO_PRIORITY_SYNC_READ);
191 	}
192 
193 	/*
194 	 * Copy the ptrtbl from the old to new location.
195 	 */
196 
197 	uint64_t b = tbl->zt_blks_copied;
198 	dmu_buf_t *db_old;
199 	int err = dmu_buf_hold(zap->zap_objset, zap->zap_object,
200 	    (tbl->zt_blk + b) << bs, FTAG, &db_old, DMU_READ_NO_PREFETCH);
201 	if (err != 0)
202 		return (err);
203 
204 	/* first half of entries in old[b] go to new[2*b+0] */
205 	dmu_buf_t *db_new;
206 	VERIFY0(dmu_buf_hold(zap->zap_objset, zap->zap_object,
207 	    (newblk + 2*b+0) << bs, FTAG, &db_new, DMU_READ_NO_PREFETCH));
208 	dmu_buf_will_dirty(db_new, tx);
209 	transfer_func(db_old->db_data, db_new->db_data, hepb);
210 	dmu_buf_rele(db_new, FTAG);
211 
212 	/* second half of entries in old[b] go to new[2*b+1] */
213 	VERIFY0(dmu_buf_hold(zap->zap_objset, zap->zap_object,
214 	    (newblk + 2*b+1) << bs, FTAG, &db_new, DMU_READ_NO_PREFETCH));
215 	dmu_buf_will_dirty(db_new, tx);
216 	transfer_func((uint64_t *)db_old->db_data + hepb,
217 	    db_new->db_data, hepb);
218 	dmu_buf_rele(db_new, FTAG);
219 
220 	dmu_buf_rele(db_old, FTAG);
221 
222 	tbl->zt_blks_copied++;
223 
224 	dprintf("copied block %llu of %llu\n",
225 	    tbl->zt_blks_copied, tbl->zt_numblks);
226 
227 	if (tbl->zt_blks_copied == tbl->zt_numblks) {
228 		(void) dmu_free_range(zap->zap_objset, zap->zap_object,
229 		    tbl->zt_blk << bs, tbl->zt_numblks << bs, tx);
230 
231 		tbl->zt_blk = newblk;
232 		tbl->zt_numblks *= 2;
233 		tbl->zt_shift++;
234 		tbl->zt_nextblk = 0;
235 		tbl->zt_blks_copied = 0;
236 
237 		dprintf("finished; numblocks now %llu (%lluk entries)\n",
238 		    tbl->zt_numblks, 1<<(tbl->zt_shift-10));
239 	}
240 
241 	return (0);
242 }
243 
244 static int
zap_table_store(zap_t * zap,zap_table_phys_t * tbl,uint64_t idx,uint64_t val,dmu_tx_t * tx)245 zap_table_store(zap_t *zap, zap_table_phys_t *tbl, uint64_t idx, uint64_t val,
246     dmu_tx_t *tx)
247 {
248 	int bs = FZAP_BLOCK_SHIFT(zap);
249 
250 	ASSERT(RW_LOCK_HELD(&zap->zap_rwlock));
251 	ASSERT(tbl->zt_blk != 0);
252 
253 	dprintf("storing %llx at index %llx\n", val, idx);
254 
255 	uint64_t blk = idx >> (bs-3);
256 	uint64_t off = idx & ((1<<(bs-3))-1);
257 
258 	dmu_buf_t *db;
259 	int err = dmu_buf_hold(zap->zap_objset, zap->zap_object,
260 	    (tbl->zt_blk + blk) << bs, FTAG, &db, DMU_READ_NO_PREFETCH);
261 	if (err != 0)
262 		return (err);
263 	dmu_buf_will_dirty(db, tx);
264 
265 	if (tbl->zt_nextblk != 0) {
266 		uint64_t idx2 = idx * 2;
267 		uint64_t blk2 = idx2 >> (bs-3);
268 		uint64_t off2 = idx2 & ((1<<(bs-3))-1);
269 		dmu_buf_t *db2;
270 
271 		err = dmu_buf_hold(zap->zap_objset, zap->zap_object,
272 		    (tbl->zt_nextblk + blk2) << bs, FTAG, &db2,
273 		    DMU_READ_NO_PREFETCH);
274 		if (err != 0) {
275 			dmu_buf_rele(db, FTAG);
276 			return (err);
277 		}
278 		dmu_buf_will_dirty(db2, tx);
279 		((uint64_t *)db2->db_data)[off2] = val;
280 		((uint64_t *)db2->db_data)[off2+1] = val;
281 		dmu_buf_rele(db2, FTAG);
282 	}
283 
284 	((uint64_t *)db->db_data)[off] = val;
285 	dmu_buf_rele(db, FTAG);
286 
287 	return (0);
288 }
289 
290 static int
zap_table_load(zap_t * zap,zap_table_phys_t * tbl,uint64_t idx,uint64_t * valp)291 zap_table_load(zap_t *zap, zap_table_phys_t *tbl, uint64_t idx, uint64_t *valp)
292 {
293 	int bs = FZAP_BLOCK_SHIFT(zap);
294 
295 	ASSERT(RW_LOCK_HELD(&zap->zap_rwlock));
296 
297 	uint64_t blk = idx >> (bs-3);
298 	uint64_t off = idx & ((1<<(bs-3))-1);
299 
300 	/*
301 	 * Note: this is equivalent to dmu_buf_hold(), but we use
302 	 * _dnode_enter / _by_dnode because it's faster because we don't
303 	 * have to hold the dnode.
304 	 */
305 	dnode_t *dn = dmu_buf_dnode_enter(zap->zap_dbuf);
306 	dmu_buf_t *db;
307 	int err = dmu_buf_hold_by_dnode(dn,
308 	    (tbl->zt_blk + blk) << bs, FTAG, &db, DMU_READ_NO_PREFETCH);
309 	dmu_buf_dnode_exit(zap->zap_dbuf);
310 	if (err != 0)
311 		return (err);
312 	*valp = ((uint64_t *)db->db_data)[off];
313 	dmu_buf_rele(db, FTAG);
314 
315 	if (tbl->zt_nextblk != 0) {
316 		/*
317 		 * read the nextblk for the sake of i/o error checking,
318 		 * so that zap_table_load() will catch errors for
319 		 * zap_table_store.
320 		 */
321 		blk = (idx*2) >> (bs-3);
322 
323 		dn = dmu_buf_dnode_enter(zap->zap_dbuf);
324 		err = dmu_buf_hold_by_dnode(dn,
325 		    (tbl->zt_nextblk + blk) << bs, FTAG, &db,
326 		    DMU_READ_NO_PREFETCH);
327 		dmu_buf_dnode_exit(zap->zap_dbuf);
328 		if (err == 0)
329 			dmu_buf_rele(db, FTAG);
330 	}
331 	return (err);
332 }
333 
334 /*
335  * Routines for growing the ptrtbl.
336  */
337 
338 static void
zap_ptrtbl_transfer(const uint64_t * src,uint64_t * dst,int n)339 zap_ptrtbl_transfer(const uint64_t *src, uint64_t *dst, int n)
340 {
341 	for (int i = 0; i < n; i++) {
342 		uint64_t lb = src[i];
343 		dst[2 * i + 0] = lb;
344 		dst[2 * i + 1] = lb;
345 	}
346 }
347 
348 static int
zap_grow_ptrtbl(zap_t * zap,dmu_tx_t * tx)349 zap_grow_ptrtbl(zap_t *zap, dmu_tx_t *tx)
350 {
351 	/*
352 	 * The pointer table should never use more hash bits than we
353 	 * have (otherwise we'd be using useless zero bits to index it).
354 	 * If we are within 2 bits of running out, stop growing, since
355 	 * this is already an aberrant condition.
356 	 */
357 	if (zap_f_phys(zap)->zap_ptrtbl.zt_shift >= zap_hashbits(zap) - 2)
358 		return (SET_ERROR(ENOSPC));
359 
360 	if (zap_f_phys(zap)->zap_ptrtbl.zt_numblks == 0) {
361 		/*
362 		 * We are outgrowing the "embedded" ptrtbl (the one
363 		 * stored in the header block).  Give it its own entire
364 		 * block, which will double the size of the ptrtbl.
365 		 */
366 		ASSERT3U(zap_f_phys(zap)->zap_ptrtbl.zt_shift, ==,
367 		    ZAP_EMBEDDED_PTRTBL_SHIFT(zap));
368 		ASSERT0(zap_f_phys(zap)->zap_ptrtbl.zt_blk);
369 
370 		uint64_t newblk = zap_allocate_blocks(zap, 1);
371 		dmu_buf_t *db_new;
372 		int err = dmu_buf_hold(zap->zap_objset, zap->zap_object,
373 		    newblk << FZAP_BLOCK_SHIFT(zap), FTAG, &db_new,
374 		    DMU_READ_NO_PREFETCH);
375 		if (err != 0)
376 			return (err);
377 		dmu_buf_will_dirty(db_new, tx);
378 		zap_ptrtbl_transfer(&ZAP_EMBEDDED_PTRTBL_ENT(zap, 0),
379 		    db_new->db_data, 1 << ZAP_EMBEDDED_PTRTBL_SHIFT(zap));
380 		dmu_buf_rele(db_new, FTAG);
381 
382 		zap_f_phys(zap)->zap_ptrtbl.zt_blk = newblk;
383 		zap_f_phys(zap)->zap_ptrtbl.zt_numblks = 1;
384 		zap_f_phys(zap)->zap_ptrtbl.zt_shift++;
385 
386 		ASSERT3U(1ULL << zap_f_phys(zap)->zap_ptrtbl.zt_shift, ==,
387 		    zap_f_phys(zap)->zap_ptrtbl.zt_numblks <<
388 		    (FZAP_BLOCK_SHIFT(zap)-3));
389 
390 		return (0);
391 	} else {
392 		return (zap_table_grow(zap, &zap_f_phys(zap)->zap_ptrtbl,
393 		    zap_ptrtbl_transfer, tx));
394 	}
395 }
396 
397 static void
zap_increment_num_entries(zap_t * zap,int delta,dmu_tx_t * tx)398 zap_increment_num_entries(zap_t *zap, int delta, dmu_tx_t *tx)
399 {
400 	dmu_buf_will_dirty(zap->zap_dbuf, tx);
401 	mutex_enter(&zap->zap_f.zap_num_entries_mtx);
402 	ASSERT(delta > 0 || zap_f_phys(zap)->zap_num_entries >= -delta);
403 	zap_f_phys(zap)->zap_num_entries += delta;
404 	mutex_exit(&zap->zap_f.zap_num_entries_mtx);
405 }
406 
407 static uint64_t
zap_allocate_blocks(zap_t * zap,int nblocks)408 zap_allocate_blocks(zap_t *zap, int nblocks)
409 {
410 	ASSERT(RW_WRITE_HELD(&zap->zap_rwlock));
411 	uint64_t newblk = zap_f_phys(zap)->zap_freeblk;
412 	zap_f_phys(zap)->zap_freeblk += nblocks;
413 	return (newblk);
414 }
415 
416 static void
zap_leaf_evict_sync(void * dbu)417 zap_leaf_evict_sync(void *dbu)
418 {
419 	zap_leaf_t *l = dbu;
420 
421 	rw_destroy(&l->l_rwlock);
422 	kmem_free(l, sizeof (zap_leaf_t));
423 }
424 
425 static zap_leaf_t *
zap_create_leaf(zap_t * zap,dmu_tx_t * tx)426 zap_create_leaf(zap_t *zap, dmu_tx_t *tx)
427 {
428 	zap_leaf_t *l = kmem_zalloc(sizeof (zap_leaf_t), KM_SLEEP);
429 
430 	ASSERT(RW_WRITE_HELD(&zap->zap_rwlock));
431 
432 	rw_init(&l->l_rwlock, 0, 0, 0);
433 	rw_enter(&l->l_rwlock, RW_WRITER);
434 	l->l_blkid = zap_allocate_blocks(zap, 1);
435 	l->l_dbuf = NULL;
436 
437 	VERIFY0(dmu_buf_hold(zap->zap_objset, zap->zap_object,
438 	    l->l_blkid << FZAP_BLOCK_SHIFT(zap), NULL, &l->l_dbuf,
439 	    DMU_READ_NO_PREFETCH));
440 	dmu_buf_init_user(&l->l_dbu, zap_leaf_evict_sync, NULL, &l->l_dbuf);
441 	VERIFY3P(NULL, ==, dmu_buf_set_user(l->l_dbuf, &l->l_dbu));
442 	dmu_buf_will_dirty(l->l_dbuf, tx);
443 
444 	zap_leaf_init(l, zap->zap_normflags != 0);
445 
446 	zap_f_phys(zap)->zap_num_leafs++;
447 
448 	return (l);
449 }
450 
451 int
fzap_count(zap_t * zap,uint64_t * count)452 fzap_count(zap_t *zap, uint64_t *count)
453 {
454 	ASSERT(!zap->zap_ismicro);
455 	mutex_enter(&zap->zap_f.zap_num_entries_mtx); /* unnecessary */
456 	*count = zap_f_phys(zap)->zap_num_entries;
457 	mutex_exit(&zap->zap_f.zap_num_entries_mtx);
458 	return (0);
459 }
460 
461 /*
462  * Routines for obtaining zap_leaf_t's
463  */
464 
465 void
zap_put_leaf(zap_leaf_t * l)466 zap_put_leaf(zap_leaf_t *l)
467 {
468 	rw_exit(&l->l_rwlock);
469 	dmu_buf_rele(l->l_dbuf, NULL);
470 }
471 
472 static zap_leaf_t *
zap_open_leaf(uint64_t blkid,dmu_buf_t * db)473 zap_open_leaf(uint64_t blkid, dmu_buf_t *db)
474 {
475 	ASSERT(blkid != 0);
476 
477 	zap_leaf_t *l = kmem_zalloc(sizeof (zap_leaf_t), KM_SLEEP);
478 	rw_init(&l->l_rwlock, 0, 0, 0);
479 	rw_enter(&l->l_rwlock, RW_WRITER);
480 	l->l_blkid = blkid;
481 	l->l_bs = highbit64(db->db_size) - 1;
482 	l->l_dbuf = db;
483 
484 	dmu_buf_init_user(&l->l_dbu, zap_leaf_evict_sync, NULL, &l->l_dbuf);
485 	zap_leaf_t *winner = dmu_buf_set_user(db, &l->l_dbu);
486 
487 	rw_exit(&l->l_rwlock);
488 	if (winner != NULL) {
489 		/* someone else set it first */
490 		zap_leaf_evict_sync(&l->l_dbu);
491 		l = winner;
492 	}
493 
494 	/*
495 	 * lhr_pad was previously used for the next leaf in the leaf
496 	 * chain.  There should be no chained leafs (as we have removed
497 	 * support for them).
498 	 */
499 	ASSERT0(zap_leaf_phys(l)->l_hdr.lh_pad1);
500 
501 	/*
502 	 * There should be more hash entries than there can be
503 	 * chunks to put in the hash table
504 	 */
505 	ASSERT3U(ZAP_LEAF_HASH_NUMENTRIES(l), >, ZAP_LEAF_NUMCHUNKS(l) / 3);
506 
507 	/* The chunks should begin at the end of the hash table */
508 	ASSERT3P(&ZAP_LEAF_CHUNK(l, 0), ==,
509 	    &zap_leaf_phys(l)->l_hash[ZAP_LEAF_HASH_NUMENTRIES(l)]);
510 
511 	/* The chunks should end at the end of the block */
512 	ASSERT3U((uintptr_t)&ZAP_LEAF_CHUNK(l, ZAP_LEAF_NUMCHUNKS(l)) -
513 	    (uintptr_t)zap_leaf_phys(l), ==, l->l_dbuf->db_size);
514 
515 	return (l);
516 }
517 
518 static int
zap_get_leaf_byblk(zap_t * zap,uint64_t blkid,dmu_tx_t * tx,krw_t lt,zap_leaf_t ** lp)519 zap_get_leaf_byblk(zap_t *zap, uint64_t blkid, dmu_tx_t *tx, krw_t lt,
520     zap_leaf_t **lp)
521 {
522 	dmu_buf_t *db;
523 
524 	ASSERT(RW_LOCK_HELD(&zap->zap_rwlock));
525 
526 	int bs = FZAP_BLOCK_SHIFT(zap);
527 	dnode_t *dn = dmu_buf_dnode_enter(zap->zap_dbuf);
528 	int err = dmu_buf_hold_by_dnode(dn,
529 	    blkid << bs, NULL, &db, DMU_READ_NO_PREFETCH);
530 	dmu_buf_dnode_exit(zap->zap_dbuf);
531 	if (err != 0)
532 		return (err);
533 
534 	ASSERT3U(db->db_object, ==, zap->zap_object);
535 	ASSERT3U(db->db_offset, ==, blkid << bs);
536 	ASSERT3U(db->db_size, ==, 1 << bs);
537 	ASSERT(blkid != 0);
538 
539 	zap_leaf_t *l = dmu_buf_get_user(db);
540 
541 	if (l == NULL)
542 		l = zap_open_leaf(blkid, db);
543 
544 	rw_enter(&l->l_rwlock, lt);
545 	/*
546 	 * Must lock before dirtying, otherwise zap_leaf_phys(l) could change,
547 	 * causing ASSERT below to fail.
548 	 */
549 	if (lt == RW_WRITER)
550 		dmu_buf_will_dirty(db, tx);
551 	ASSERT3U(l->l_blkid, ==, blkid);
552 	ASSERT3P(l->l_dbuf, ==, db);
553 	ASSERT3U(zap_leaf_phys(l)->l_hdr.lh_block_type, ==, ZBT_LEAF);
554 	ASSERT3U(zap_leaf_phys(l)->l_hdr.lh_magic, ==, ZAP_LEAF_MAGIC);
555 
556 	*lp = l;
557 	return (0);
558 }
559 
560 static int
zap_idx_to_blk(zap_t * zap,uint64_t idx,uint64_t * valp)561 zap_idx_to_blk(zap_t *zap, uint64_t idx, uint64_t *valp)
562 {
563 	ASSERT(RW_LOCK_HELD(&zap->zap_rwlock));
564 
565 	if (zap_f_phys(zap)->zap_ptrtbl.zt_numblks == 0) {
566 		ASSERT3U(idx, <,
567 		    (1ULL << zap_f_phys(zap)->zap_ptrtbl.zt_shift));
568 		*valp = ZAP_EMBEDDED_PTRTBL_ENT(zap, idx);
569 		return (0);
570 	} else {
571 		return (zap_table_load(zap, &zap_f_phys(zap)->zap_ptrtbl,
572 		    idx, valp));
573 	}
574 }
575 
576 static int
zap_set_idx_to_blk(zap_t * zap,uint64_t idx,uint64_t blk,dmu_tx_t * tx)577 zap_set_idx_to_blk(zap_t *zap, uint64_t idx, uint64_t blk, dmu_tx_t *tx)
578 {
579 	ASSERT(tx != NULL);
580 	ASSERT(RW_WRITE_HELD(&zap->zap_rwlock));
581 
582 	if (zap_f_phys(zap)->zap_ptrtbl.zt_blk == 0) {
583 		ZAP_EMBEDDED_PTRTBL_ENT(zap, idx) = blk;
584 		return (0);
585 	} else {
586 		return (zap_table_store(zap, &zap_f_phys(zap)->zap_ptrtbl,
587 		    idx, blk, tx));
588 	}
589 }
590 
591 static int
zap_deref_leaf(zap_t * zap,uint64_t h,dmu_tx_t * tx,krw_t lt,zap_leaf_t ** lp)592 zap_deref_leaf(zap_t *zap, uint64_t h, dmu_tx_t *tx, krw_t lt, zap_leaf_t **lp)
593 {
594 	uint64_t blk;
595 
596 	ASSERT(zap->zap_dbuf == NULL ||
597 	    zap_f_phys(zap) == zap->zap_dbuf->db_data);
598 
599 	/* Reality check for corrupt zap objects (leaf or header). */
600 	if ((zap_f_phys(zap)->zap_block_type != ZBT_LEAF &&
601 	    zap_f_phys(zap)->zap_block_type != ZBT_HEADER) ||
602 	    zap_f_phys(zap)->zap_magic != ZAP_MAGIC) {
603 		return (SET_ERROR(EIO));
604 	}
605 
606 	uint64_t idx = ZAP_HASH_IDX(h, zap_f_phys(zap)->zap_ptrtbl.zt_shift);
607 	int err = zap_idx_to_blk(zap, idx, &blk);
608 	if (err != 0)
609 		return (err);
610 	err = zap_get_leaf_byblk(zap, blk, tx, lt, lp);
611 
612 	ASSERT(err ||
613 	    ZAP_HASH_IDX(h, zap_leaf_phys(*lp)->l_hdr.lh_prefix_len) ==
614 	    zap_leaf_phys(*lp)->l_hdr.lh_prefix);
615 	return (err);
616 }
617 
618 static int
zap_expand_leaf(zap_name_t * zn,zap_leaf_t * l,void * tag,dmu_tx_t * tx,zap_leaf_t ** lp)619 zap_expand_leaf(zap_name_t *zn, zap_leaf_t *l,
620     void *tag, dmu_tx_t *tx, zap_leaf_t **lp)
621 {
622 	zap_t *zap = zn->zn_zap;
623 	uint64_t hash = zn->zn_hash;
624 	int err;
625 	int old_prefix_len = zap_leaf_phys(l)->l_hdr.lh_prefix_len;
626 
627 	ASSERT3U(old_prefix_len, <=, zap_f_phys(zap)->zap_ptrtbl.zt_shift);
628 	ASSERT(RW_LOCK_HELD(&zap->zap_rwlock));
629 
630 	ASSERT3U(ZAP_HASH_IDX(hash, old_prefix_len), ==,
631 	    zap_leaf_phys(l)->l_hdr.lh_prefix);
632 
633 	if (zap_tryupgradedir(zap, tx) == 0 ||
634 	    old_prefix_len == zap_f_phys(zap)->zap_ptrtbl.zt_shift) {
635 		/* We failed to upgrade, or need to grow the pointer table */
636 		objset_t *os = zap->zap_objset;
637 		uint64_t object = zap->zap_object;
638 
639 		zap_put_leaf(l);
640 		zap_unlockdir(zap, tag);
641 		err = zap_lockdir(os, object, tx, RW_WRITER,
642 		    FALSE, FALSE, tag, &zn->zn_zap);
643 		zap = zn->zn_zap;
644 		if (err != 0)
645 			return (err);
646 		ASSERT(!zap->zap_ismicro);
647 
648 		while (old_prefix_len ==
649 		    zap_f_phys(zap)->zap_ptrtbl.zt_shift) {
650 			err = zap_grow_ptrtbl(zap, tx);
651 			if (err != 0)
652 				return (err);
653 		}
654 
655 		err = zap_deref_leaf(zap, hash, tx, RW_WRITER, &l);
656 		if (err != 0)
657 			return (err);
658 
659 		if (zap_leaf_phys(l)->l_hdr.lh_prefix_len != old_prefix_len) {
660 			/* it split while our locks were down */
661 			*lp = l;
662 			return (0);
663 		}
664 	}
665 	ASSERT(RW_WRITE_HELD(&zap->zap_rwlock));
666 	ASSERT3U(old_prefix_len, <, zap_f_phys(zap)->zap_ptrtbl.zt_shift);
667 	ASSERT3U(ZAP_HASH_IDX(hash, old_prefix_len), ==,
668 	    zap_leaf_phys(l)->l_hdr.lh_prefix);
669 
670 	int prefix_diff = zap_f_phys(zap)->zap_ptrtbl.zt_shift -
671 	    (old_prefix_len + 1);
672 	uint64_t sibling =
673 	    (ZAP_HASH_IDX(hash, old_prefix_len + 1) | 1) << prefix_diff;
674 
675 	/* check for i/o errors before doing zap_leaf_split */
676 	for (int i = 0; i < (1ULL << prefix_diff); i++) {
677 		uint64_t blk;
678 		err = zap_idx_to_blk(zap, sibling + i, &blk);
679 		if (err != 0)
680 			return (err);
681 		ASSERT3U(blk, ==, l->l_blkid);
682 	}
683 
684 	zap_leaf_t *nl = zap_create_leaf(zap, tx);
685 	zap_leaf_split(l, nl, zap->zap_normflags != 0);
686 
687 	/* set sibling pointers */
688 	for (int i = 0; i < (1ULL << prefix_diff); i++) {
689 		err = zap_set_idx_to_blk(zap, sibling + i, nl->l_blkid, tx);
690 		ASSERT0(err); /* we checked for i/o errors above */
691 	}
692 
693 	if (hash & (1ULL << (64 - zap_leaf_phys(l)->l_hdr.lh_prefix_len))) {
694 		/* we want the sibling */
695 		zap_put_leaf(l);
696 		*lp = nl;
697 	} else {
698 		zap_put_leaf(nl);
699 		*lp = l;
700 	}
701 
702 	return (0);
703 }
704 
705 static void
zap_put_leaf_maybe_grow_ptrtbl(zap_name_t * zn,zap_leaf_t * l,void * tag,dmu_tx_t * tx)706 zap_put_leaf_maybe_grow_ptrtbl(zap_name_t *zn, zap_leaf_t *l,
707     void *tag, dmu_tx_t *tx)
708 {
709 	zap_t *zap = zn->zn_zap;
710 	int shift = zap_f_phys(zap)->zap_ptrtbl.zt_shift;
711 	int leaffull = (zap_leaf_phys(l)->l_hdr.lh_prefix_len == shift &&
712 	    zap_leaf_phys(l)->l_hdr.lh_nfree < ZAP_LEAF_LOW_WATER);
713 
714 	zap_put_leaf(l);
715 
716 	if (leaffull || zap_f_phys(zap)->zap_ptrtbl.zt_nextblk) {
717 		/*
718 		 * We are in the middle of growing the pointer table, or
719 		 * this leaf will soon make us grow it.
720 		 */
721 		if (zap_tryupgradedir(zap, tx) == 0) {
722 			objset_t *os = zap->zap_objset;
723 			uint64_t zapobj = zap->zap_object;
724 
725 			zap_unlockdir(zap, tag);
726 			int err = zap_lockdir(os, zapobj, tx,
727 			    RW_WRITER, FALSE, FALSE, tag, &zn->zn_zap);
728 			zap = zn->zn_zap;
729 			if (err != 0)
730 				return;
731 		}
732 
733 		/* could have finished growing while our locks were down */
734 		if (zap_f_phys(zap)->zap_ptrtbl.zt_shift == shift)
735 			(void) zap_grow_ptrtbl(zap, tx);
736 	}
737 }
738 
739 static int
fzap_checkname(zap_name_t * zn)740 fzap_checkname(zap_name_t *zn)
741 {
742 	if (zn->zn_key_orig_numints * zn->zn_key_intlen > ZAP_MAXNAMELEN)
743 		return (SET_ERROR(ENAMETOOLONG));
744 	return (0);
745 }
746 
747 static int
fzap_checksize(uint64_t integer_size,uint64_t num_integers)748 fzap_checksize(uint64_t integer_size, uint64_t num_integers)
749 {
750 	/* Only integer sizes supported by C */
751 	switch (integer_size) {
752 	case 1:
753 	case 2:
754 	case 4:
755 	case 8:
756 		break;
757 	default:
758 		return (SET_ERROR(EINVAL));
759 	}
760 
761 	if (integer_size * num_integers > ZAP_MAXVALUELEN)
762 		return (E2BIG);
763 
764 	return (0);
765 }
766 
767 static int
fzap_check(zap_name_t * zn,uint64_t integer_size,uint64_t num_integers)768 fzap_check(zap_name_t *zn, uint64_t integer_size, uint64_t num_integers)
769 {
770 	int err = fzap_checkname(zn);
771 	if (err != 0)
772 		return (err);
773 	return (fzap_checksize(integer_size, num_integers));
774 }
775 
776 /*
777  * Routines for manipulating attributes.
778  */
779 int
fzap_lookup(zap_name_t * zn,uint64_t integer_size,uint64_t num_integers,void * buf,char * realname,int rn_len,boolean_t * ncp)780 fzap_lookup(zap_name_t *zn,
781     uint64_t integer_size, uint64_t num_integers, void *buf,
782     char *realname, int rn_len, boolean_t *ncp)
783 {
784 	zap_leaf_t *l;
785 	zap_entry_handle_t zeh;
786 
787 	int err = fzap_checkname(zn);
788 	if (err != 0)
789 		return (err);
790 
791 	err = zap_deref_leaf(zn->zn_zap, zn->zn_hash, NULL, RW_READER, &l);
792 	if (err != 0)
793 		return (err);
794 	err = zap_leaf_lookup(l, zn, &zeh);
795 	if (err == 0) {
796 		if ((err = fzap_checksize(integer_size, num_integers)) != 0) {
797 			zap_put_leaf(l);
798 			return (err);
799 		}
800 
801 		err = zap_entry_read(&zeh, integer_size, num_integers, buf);
802 		(void) zap_entry_read_name(zn->zn_zap, &zeh, rn_len, realname);
803 		if (ncp) {
804 			*ncp = zap_entry_normalization_conflict(&zeh,
805 			    zn, NULL, zn->zn_zap);
806 		}
807 	}
808 
809 	zap_put_leaf(l);
810 	return (err);
811 }
812 
813 int
fzap_add_cd(zap_name_t * zn,uint64_t integer_size,uint64_t num_integers,const void * val,uint32_t cd,void * tag,dmu_tx_t * tx)814 fzap_add_cd(zap_name_t *zn,
815     uint64_t integer_size, uint64_t num_integers,
816     const void *val, uint32_t cd, void *tag, dmu_tx_t *tx)
817 {
818 	zap_leaf_t *l;
819 	int err;
820 	zap_entry_handle_t zeh;
821 	zap_t *zap = zn->zn_zap;
822 
823 	ASSERT(RW_LOCK_HELD(&zap->zap_rwlock));
824 	ASSERT(!zap->zap_ismicro);
825 	ASSERT(fzap_check(zn, integer_size, num_integers) == 0);
826 
827 	err = zap_deref_leaf(zap, zn->zn_hash, tx, RW_WRITER, &l);
828 	if (err != 0)
829 		return (err);
830 retry:
831 	err = zap_leaf_lookup(l, zn, &zeh);
832 	if (err == 0) {
833 		err = SET_ERROR(EEXIST);
834 		goto out;
835 	}
836 	if (err != ENOENT)
837 		goto out;
838 
839 	err = zap_entry_create(l, zn, cd,
840 	    integer_size, num_integers, val, &zeh);
841 
842 	if (err == 0) {
843 		zap_increment_num_entries(zap, 1, tx);
844 	} else if (err == EAGAIN) {
845 		err = zap_expand_leaf(zn, l, tag, tx, &l);
846 		zap = zn->zn_zap;	/* zap_expand_leaf() may change zap */
847 		if (err == 0)
848 			goto retry;
849 	}
850 
851 out:
852 	if (zap != NULL)
853 		zap_put_leaf_maybe_grow_ptrtbl(zn, l, tag, tx);
854 	return (err);
855 }
856 
857 int
fzap_add(zap_name_t * zn,uint64_t integer_size,uint64_t num_integers,const void * val,void * tag,dmu_tx_t * tx)858 fzap_add(zap_name_t *zn,
859     uint64_t integer_size, uint64_t num_integers,
860     const void *val, void *tag, dmu_tx_t *tx)
861 {
862 	int err = fzap_check(zn, integer_size, num_integers);
863 	if (err != 0)
864 		return (err);
865 
866 	return (fzap_add_cd(zn, integer_size, num_integers,
867 	    val, ZAP_NEED_CD, tag, tx));
868 }
869 
870 int
fzap_update(zap_name_t * zn,int integer_size,uint64_t num_integers,const void * val,void * tag,dmu_tx_t * tx)871 fzap_update(zap_name_t *zn,
872     int integer_size, uint64_t num_integers, const void *val,
873     void *tag, dmu_tx_t *tx)
874 {
875 	zap_leaf_t *l;
876 	int err;
877 	boolean_t create;
878 	zap_entry_handle_t zeh;
879 	zap_t *zap = zn->zn_zap;
880 
881 	ASSERT(RW_LOCK_HELD(&zap->zap_rwlock));
882 	err = fzap_check(zn, integer_size, num_integers);
883 	if (err != 0)
884 		return (err);
885 
886 	err = zap_deref_leaf(zap, zn->zn_hash, tx, RW_WRITER, &l);
887 	if (err != 0)
888 		return (err);
889 retry:
890 	err = zap_leaf_lookup(l, zn, &zeh);
891 	create = (err == ENOENT);
892 	ASSERT(err == 0 || err == ENOENT);
893 
894 	if (create) {
895 		err = zap_entry_create(l, zn, ZAP_NEED_CD,
896 		    integer_size, num_integers, val, &zeh);
897 		if (err == 0)
898 			zap_increment_num_entries(zap, 1, tx);
899 	} else {
900 		err = zap_entry_update(&zeh, integer_size, num_integers, val);
901 	}
902 
903 	if (err == EAGAIN) {
904 		err = zap_expand_leaf(zn, l, tag, tx, &l);
905 		zap = zn->zn_zap;	/* zap_expand_leaf() may change zap */
906 		if (err == 0)
907 			goto retry;
908 	}
909 
910 	if (zap != NULL)
911 		zap_put_leaf_maybe_grow_ptrtbl(zn, l, tag, tx);
912 	return (err);
913 }
914 
915 int
fzap_length(zap_name_t * zn,uint64_t * integer_size,uint64_t * num_integers)916 fzap_length(zap_name_t *zn,
917     uint64_t *integer_size, uint64_t *num_integers)
918 {
919 	zap_leaf_t *l;
920 	int err;
921 	zap_entry_handle_t zeh;
922 
923 	err = zap_deref_leaf(zn->zn_zap, zn->zn_hash, NULL, RW_READER, &l);
924 	if (err != 0)
925 		return (err);
926 	err = zap_leaf_lookup(l, zn, &zeh);
927 	if (err != 0)
928 		goto out;
929 
930 	if (integer_size != 0)
931 		*integer_size = zeh.zeh_integer_size;
932 	if (num_integers != 0)
933 		*num_integers = zeh.zeh_num_integers;
934 out:
935 	zap_put_leaf(l);
936 	return (err);
937 }
938 
939 int
fzap_remove(zap_name_t * zn,dmu_tx_t * tx)940 fzap_remove(zap_name_t *zn, dmu_tx_t *tx)
941 {
942 	zap_leaf_t *l;
943 	int err;
944 	zap_entry_handle_t zeh;
945 
946 	err = zap_deref_leaf(zn->zn_zap, zn->zn_hash, tx, RW_WRITER, &l);
947 	if (err != 0)
948 		return (err);
949 	err = zap_leaf_lookup(l, zn, &zeh);
950 	if (err == 0) {
951 		zap_entry_remove(&zeh);
952 		zap_increment_num_entries(zn->zn_zap, -1, tx);
953 	}
954 	zap_put_leaf(l);
955 	return (err);
956 }
957 
958 void
fzap_prefetch(zap_name_t * zn)959 fzap_prefetch(zap_name_t *zn)
960 {
961 	uint64_t blk;
962 	zap_t *zap = zn->zn_zap;
963 
964 	uint64_t idx = ZAP_HASH_IDX(zn->zn_hash,
965 	    zap_f_phys(zap)->zap_ptrtbl.zt_shift);
966 	if (zap_idx_to_blk(zap, idx, &blk) != 0)
967 		return;
968 	int bs = FZAP_BLOCK_SHIFT(zap);
969 	dmu_prefetch(zap->zap_objset, zap->zap_object, 0, blk << bs, 1 << bs,
970 	    ZIO_PRIORITY_SYNC_READ);
971 }
972 
973 /*
974  * Helper functions for consumers.
975  */
976 
977 uint64_t
zap_create_link(objset_t * os,dmu_object_type_t ot,uint64_t parent_obj,const char * name,dmu_tx_t * tx)978 zap_create_link(objset_t *os, dmu_object_type_t ot, uint64_t parent_obj,
979     const char *name, dmu_tx_t *tx)
980 {
981 	return (zap_create_link_dnsize(os, ot, parent_obj, name, 0, tx));
982 }
983 
984 uint64_t
zap_create_link_dnsize(objset_t * os,dmu_object_type_t ot,uint64_t parent_obj,const char * name,int dnodesize,dmu_tx_t * tx)985 zap_create_link_dnsize(objset_t *os, dmu_object_type_t ot, uint64_t parent_obj,
986     const char *name, int dnodesize, dmu_tx_t *tx)
987 {
988 	uint64_t new_obj;
989 
990 	VERIFY((new_obj = zap_create_dnsize(os, ot, DMU_OT_NONE, 0,
991 	    dnodesize, tx)) > 0);
992 	VERIFY0(zap_add(os, parent_obj, name, sizeof (uint64_t), 1, &new_obj,
993 	    tx));
994 
995 	return (new_obj);
996 }
997 
998 int
zap_value_search(objset_t * os,uint64_t zapobj,uint64_t value,uint64_t mask,char * name)999 zap_value_search(objset_t *os, uint64_t zapobj, uint64_t value, uint64_t mask,
1000     char *name)
1001 {
1002 	zap_cursor_t zc;
1003 	int err;
1004 
1005 	if (mask == 0)
1006 		mask = -1ULL;
1007 
1008 	zap_attribute_t *za = kmem_alloc(sizeof (*za), KM_SLEEP);
1009 	for (zap_cursor_init(&zc, os, zapobj);
1010 	    (err = zap_cursor_retrieve(&zc, za)) == 0;
1011 	    zap_cursor_advance(&zc)) {
1012 		if ((za->za_first_integer & mask) == (value & mask)) {
1013 			(void) strcpy(name, za->za_name);
1014 			break;
1015 		}
1016 	}
1017 	zap_cursor_fini(&zc);
1018 	kmem_free(za, sizeof (*za));
1019 	return (err);
1020 }
1021 
1022 int
zap_join(objset_t * os,uint64_t fromobj,uint64_t intoobj,dmu_tx_t * tx)1023 zap_join(objset_t *os, uint64_t fromobj, uint64_t intoobj, dmu_tx_t *tx)
1024 {
1025 	zap_cursor_t zc;
1026 	int err = 0;
1027 
1028 	zap_attribute_t *za = kmem_alloc(sizeof (*za), KM_SLEEP);
1029 	for (zap_cursor_init(&zc, os, fromobj);
1030 	    zap_cursor_retrieve(&zc, za) == 0;
1031 	    (void) zap_cursor_advance(&zc)) {
1032 		if (za->za_integer_length != 8 || za->za_num_integers != 1) {
1033 			err = SET_ERROR(EINVAL);
1034 			break;
1035 		}
1036 		err = zap_add(os, intoobj, za->za_name,
1037 		    8, 1, &za->za_first_integer, tx);
1038 		if (err != 0)
1039 			break;
1040 	}
1041 	zap_cursor_fini(&zc);
1042 	kmem_free(za, sizeof (*za));
1043 	return (err);
1044 }
1045 
1046 int
zap_join_key(objset_t * os,uint64_t fromobj,uint64_t intoobj,uint64_t value,dmu_tx_t * tx)1047 zap_join_key(objset_t *os, uint64_t fromobj, uint64_t intoobj,
1048     uint64_t value, dmu_tx_t *tx)
1049 {
1050 	zap_cursor_t zc;
1051 	int err = 0;
1052 
1053 	zap_attribute_t *za = kmem_alloc(sizeof (*za), KM_SLEEP);
1054 	for (zap_cursor_init(&zc, os, fromobj);
1055 	    zap_cursor_retrieve(&zc, za) == 0;
1056 	    (void) zap_cursor_advance(&zc)) {
1057 		if (za->za_integer_length != 8 || za->za_num_integers != 1) {
1058 			err = SET_ERROR(EINVAL);
1059 			break;
1060 		}
1061 		err = zap_add(os, intoobj, za->za_name,
1062 		    8, 1, &value, tx);
1063 		if (err != 0)
1064 			break;
1065 	}
1066 	zap_cursor_fini(&zc);
1067 	kmem_free(za, sizeof (*za));
1068 	return (err);
1069 }
1070 
1071 int
zap_join_increment(objset_t * os,uint64_t fromobj,uint64_t intoobj,dmu_tx_t * tx)1072 zap_join_increment(objset_t *os, uint64_t fromobj, uint64_t intoobj,
1073     dmu_tx_t *tx)
1074 {
1075 	zap_cursor_t zc;
1076 	int err = 0;
1077 
1078 	zap_attribute_t *za = kmem_alloc(sizeof (*za), KM_SLEEP);
1079 	for (zap_cursor_init(&zc, os, fromobj);
1080 	    zap_cursor_retrieve(&zc, za) == 0;
1081 	    (void) zap_cursor_advance(&zc)) {
1082 		uint64_t delta = 0;
1083 
1084 		if (za->za_integer_length != 8 || za->za_num_integers != 1) {
1085 			err = SET_ERROR(EINVAL);
1086 			break;
1087 		}
1088 
1089 		err = zap_lookup(os, intoobj, za->za_name, 8, 1, &delta);
1090 		if (err != 0 && err != ENOENT)
1091 			break;
1092 		delta += za->za_first_integer;
1093 		err = zap_update(os, intoobj, za->za_name, 8, 1, &delta, tx);
1094 		if (err != 0)
1095 			break;
1096 	}
1097 	zap_cursor_fini(&zc);
1098 	kmem_free(za, sizeof (*za));
1099 	return (err);
1100 }
1101 
1102 int
zap_add_int(objset_t * os,uint64_t obj,uint64_t value,dmu_tx_t * tx)1103 zap_add_int(objset_t *os, uint64_t obj, uint64_t value, dmu_tx_t *tx)
1104 {
1105 	char name[20];
1106 
1107 	(void) snprintf(name, sizeof (name), "%llx", (longlong_t)value);
1108 	return (zap_add(os, obj, name, 8, 1, &value, tx));
1109 }
1110 
1111 int
zap_remove_int(objset_t * os,uint64_t obj,uint64_t value,dmu_tx_t * tx)1112 zap_remove_int(objset_t *os, uint64_t obj, uint64_t value, dmu_tx_t *tx)
1113 {
1114 	char name[20];
1115 
1116 	(void) snprintf(name, sizeof (name), "%llx", (longlong_t)value);
1117 	return (zap_remove(os, obj, name, tx));
1118 }
1119 
1120 int
zap_lookup_int(objset_t * os,uint64_t obj,uint64_t value)1121 zap_lookup_int(objset_t *os, uint64_t obj, uint64_t value)
1122 {
1123 	char name[20];
1124 
1125 	(void) snprintf(name, sizeof (name), "%llx", (longlong_t)value);
1126 	return (zap_lookup(os, obj, name, 8, 1, &value));
1127 }
1128 
1129 int
zap_add_int_key(objset_t * os,uint64_t obj,uint64_t key,uint64_t value,dmu_tx_t * tx)1130 zap_add_int_key(objset_t *os, uint64_t obj,
1131     uint64_t key, uint64_t value, dmu_tx_t *tx)
1132 {
1133 	char name[20];
1134 
1135 	(void) snprintf(name, sizeof (name), "%llx", (longlong_t)key);
1136 	return (zap_add(os, obj, name, 8, 1, &value, tx));
1137 }
1138 
1139 int
zap_update_int_key(objset_t * os,uint64_t obj,uint64_t key,uint64_t value,dmu_tx_t * tx)1140 zap_update_int_key(objset_t *os, uint64_t obj,
1141     uint64_t key, uint64_t value, dmu_tx_t *tx)
1142 {
1143 	char name[20];
1144 
1145 	(void) snprintf(name, sizeof (name), "%llx", (longlong_t)key);
1146 	return (zap_update(os, obj, name, 8, 1, &value, tx));
1147 }
1148 
1149 int
zap_lookup_int_key(objset_t * os,uint64_t obj,uint64_t key,uint64_t * valuep)1150 zap_lookup_int_key(objset_t *os, uint64_t obj, uint64_t key, uint64_t *valuep)
1151 {
1152 	char name[20];
1153 
1154 	(void) snprintf(name, sizeof (name), "%llx", (longlong_t)key);
1155 	return (zap_lookup(os, obj, name, 8, 1, valuep));
1156 }
1157 
1158 int
zap_increment(objset_t * os,uint64_t obj,const char * name,int64_t delta,dmu_tx_t * tx)1159 zap_increment(objset_t *os, uint64_t obj, const char *name, int64_t delta,
1160     dmu_tx_t *tx)
1161 {
1162 	uint64_t value = 0;
1163 
1164 	if (delta == 0)
1165 		return (0);
1166 
1167 	int err = zap_lookup(os, obj, name, 8, 1, &value);
1168 	if (err != 0 && err != ENOENT)
1169 		return (err);
1170 	value += delta;
1171 	if (value == 0)
1172 		err = zap_remove(os, obj, name, tx);
1173 	else
1174 		err = zap_update(os, obj, name, 8, 1, &value, tx);
1175 	return (err);
1176 }
1177 
1178 int
zap_increment_int(objset_t * os,uint64_t obj,uint64_t key,int64_t delta,dmu_tx_t * tx)1179 zap_increment_int(objset_t *os, uint64_t obj, uint64_t key, int64_t delta,
1180     dmu_tx_t *tx)
1181 {
1182 	char name[20];
1183 
1184 	(void) snprintf(name, sizeof (name), "%llx", (longlong_t)key);
1185 	return (zap_increment(os, obj, name, delta, tx));
1186 }
1187 
1188 /*
1189  * Routines for iterating over the attributes.
1190  */
1191 
1192 int
fzap_cursor_retrieve(zap_t * zap,zap_cursor_t * zc,zap_attribute_t * za)1193 fzap_cursor_retrieve(zap_t *zap, zap_cursor_t *zc, zap_attribute_t *za)
1194 {
1195 	int err = ENOENT;
1196 	zap_entry_handle_t zeh;
1197 	zap_leaf_t *l;
1198 
1199 	/* retrieve the next entry at or after zc_hash/zc_cd */
1200 	/* if no entry, return ENOENT */
1201 
1202 	/*
1203 	 * If we are reading from the beginning, we're almost
1204 	 * certain to iterate over the entire ZAP object.  If there are
1205 	 * multiple leaf blocks (freeblk > 2), prefetch the whole
1206 	 * object, so that we read the leaf blocks concurrently.
1207 	 * (Unless noprefetch was requested via zap_cursor_init_noprefetch()).
1208 	 */
1209 	if (zc->zc_hash == 0 && zap_iterate_prefetch &&
1210 	    zc->zc_prefetch && zap_f_phys(zap)->zap_freeblk > 2) {
1211 		dmu_prefetch(zc->zc_objset, zc->zc_zapobj, 0, 0,
1212 		    zap_f_phys(zap)->zap_freeblk << FZAP_BLOCK_SHIFT(zap),
1213 		    ZIO_PRIORITY_ASYNC_READ);
1214 	}
1215 
1216 	if (zc->zc_leaf &&
1217 	    (ZAP_HASH_IDX(zc->zc_hash,
1218 	    zap_leaf_phys(zc->zc_leaf)->l_hdr.lh_prefix_len) !=
1219 	    zap_leaf_phys(zc->zc_leaf)->l_hdr.lh_prefix)) {
1220 		rw_enter(&zc->zc_leaf->l_rwlock, RW_READER);
1221 		zap_put_leaf(zc->zc_leaf);
1222 		zc->zc_leaf = NULL;
1223 	}
1224 
1225 again:
1226 	if (zc->zc_leaf == NULL) {
1227 		err = zap_deref_leaf(zap, zc->zc_hash, NULL, RW_READER,
1228 		    &zc->zc_leaf);
1229 		if (err != 0)
1230 			return (err);
1231 	} else {
1232 		rw_enter(&zc->zc_leaf->l_rwlock, RW_READER);
1233 	}
1234 	l = zc->zc_leaf;
1235 
1236 	err = zap_leaf_lookup_closest(l, zc->zc_hash, zc->zc_cd, &zeh);
1237 
1238 	if (err == ENOENT) {
1239 		uint64_t nocare =
1240 		    (1ULL << (64 - zap_leaf_phys(l)->l_hdr.lh_prefix_len)) - 1;
1241 		zc->zc_hash = (zc->zc_hash & ~nocare) + nocare + 1;
1242 		zc->zc_cd = 0;
1243 		if (zap_leaf_phys(l)->l_hdr.lh_prefix_len == 0 ||
1244 		    zc->zc_hash == 0) {
1245 			zc->zc_hash = -1ULL;
1246 		} else {
1247 			zap_put_leaf(zc->zc_leaf);
1248 			zc->zc_leaf = NULL;
1249 			goto again;
1250 		}
1251 	}
1252 
1253 	if (err == 0) {
1254 		zc->zc_hash = zeh.zeh_hash;
1255 		zc->zc_cd = zeh.zeh_cd;
1256 		za->za_integer_length = zeh.zeh_integer_size;
1257 		za->za_num_integers = zeh.zeh_num_integers;
1258 		if (zeh.zeh_num_integers == 0) {
1259 			za->za_first_integer = 0;
1260 		} else {
1261 			err = zap_entry_read(&zeh, 8, 1, &za->za_first_integer);
1262 			ASSERT(err == 0 || err == EOVERFLOW);
1263 		}
1264 		err = zap_entry_read_name(zap, &zeh,
1265 		    sizeof (za->za_name), za->za_name);
1266 		ASSERT(err == 0);
1267 
1268 		za->za_normalization_conflict =
1269 		    zap_entry_normalization_conflict(&zeh,
1270 		    NULL, za->za_name, zap);
1271 	}
1272 	rw_exit(&zc->zc_leaf->l_rwlock);
1273 	return (err);
1274 }
1275 
1276 static void
zap_stats_ptrtbl(zap_t * zap,uint64_t * tbl,int len,zap_stats_t * zs)1277 zap_stats_ptrtbl(zap_t *zap, uint64_t *tbl, int len, zap_stats_t *zs)
1278 {
1279 	uint64_t lastblk = 0;
1280 
1281 	/*
1282 	 * NB: if a leaf has more pointers than an entire ptrtbl block
1283 	 * can hold, then it'll be accounted for more than once, since
1284 	 * we won't have lastblk.
1285 	 */
1286 	for (int i = 0; i < len; i++) {
1287 		zap_leaf_t *l;
1288 
1289 		if (tbl[i] == lastblk)
1290 			continue;
1291 		lastblk = tbl[i];
1292 
1293 		int err = zap_get_leaf_byblk(zap, tbl[i], NULL, RW_READER, &l);
1294 		if (err == 0) {
1295 			zap_leaf_stats(zap, l, zs);
1296 			zap_put_leaf(l);
1297 		}
1298 	}
1299 }
1300 
1301 void
fzap_get_stats(zap_t * zap,zap_stats_t * zs)1302 fzap_get_stats(zap_t *zap, zap_stats_t *zs)
1303 {
1304 	int bs = FZAP_BLOCK_SHIFT(zap);
1305 	zs->zs_blocksize = 1ULL << bs;
1306 
1307 	/*
1308 	 * Set zap_phys_t fields
1309 	 */
1310 	zs->zs_num_leafs = zap_f_phys(zap)->zap_num_leafs;
1311 	zs->zs_num_entries = zap_f_phys(zap)->zap_num_entries;
1312 	zs->zs_num_blocks = zap_f_phys(zap)->zap_freeblk;
1313 	zs->zs_block_type = zap_f_phys(zap)->zap_block_type;
1314 	zs->zs_magic = zap_f_phys(zap)->zap_magic;
1315 	zs->zs_salt = zap_f_phys(zap)->zap_salt;
1316 
1317 	/*
1318 	 * Set zap_ptrtbl fields
1319 	 */
1320 	zs->zs_ptrtbl_len = 1ULL << zap_f_phys(zap)->zap_ptrtbl.zt_shift;
1321 	zs->zs_ptrtbl_nextblk = zap_f_phys(zap)->zap_ptrtbl.zt_nextblk;
1322 	zs->zs_ptrtbl_blks_copied =
1323 	    zap_f_phys(zap)->zap_ptrtbl.zt_blks_copied;
1324 	zs->zs_ptrtbl_zt_blk = zap_f_phys(zap)->zap_ptrtbl.zt_blk;
1325 	zs->zs_ptrtbl_zt_numblks = zap_f_phys(zap)->zap_ptrtbl.zt_numblks;
1326 	zs->zs_ptrtbl_zt_shift = zap_f_phys(zap)->zap_ptrtbl.zt_shift;
1327 
1328 	if (zap_f_phys(zap)->zap_ptrtbl.zt_numblks == 0) {
1329 		/* the ptrtbl is entirely in the header block. */
1330 		zap_stats_ptrtbl(zap, &ZAP_EMBEDDED_PTRTBL_ENT(zap, 0),
1331 		    1 << ZAP_EMBEDDED_PTRTBL_SHIFT(zap), zs);
1332 	} else {
1333 		dmu_prefetch(zap->zap_objset, zap->zap_object, 0,
1334 		    zap_f_phys(zap)->zap_ptrtbl.zt_blk << bs,
1335 		    zap_f_phys(zap)->zap_ptrtbl.zt_numblks << bs,
1336 		    ZIO_PRIORITY_SYNC_READ);
1337 
1338 		for (int b = 0; b < zap_f_phys(zap)->zap_ptrtbl.zt_numblks;
1339 		    b++) {
1340 			dmu_buf_t *db;
1341 			int err;
1342 
1343 			err = dmu_buf_hold(zap->zap_objset, zap->zap_object,
1344 			    (zap_f_phys(zap)->zap_ptrtbl.zt_blk + b) << bs,
1345 			    FTAG, &db, DMU_READ_NO_PREFETCH);
1346 			if (err == 0) {
1347 				zap_stats_ptrtbl(zap, db->db_data,
1348 				    1<<(bs-3), zs);
1349 				dmu_buf_rele(db, FTAG);
1350 			}
1351 		}
1352 	}
1353 }
1354